JP7278911B2 - Screw shaft measuring method, screw shaft measuring device, and NC machine tool equipped with the same - Google Patents

Description

The present invention relates to a measuring method for measuring the dimensions of a screw shaft, a measuring device, and an NC machine tool equipped with the same.

Conventionally, as a device for measuring the accuracy of a screw shaft, for example, the device disclosed in Japanese Patent Application Laid-Open No. 2016-109483 is known. This device is for measuring the accuracy of a ball screw comprising a screw shaft and a ball nut screwed thereon.

As disclosed in the above publication, this measuring device includes a driving section for driving the screw shaft and a lock for preventing rotation of the ball nut so as to be movable along the axial direction of the screw shaft when the screw shaft is driven. a detection unit for detecting the position of the ball nut in the axial direction of the screw shaft; A load applying section that applies a constant force, and a drive that controls the driving section so that the ball nut reciprocates in the entire thread groove of the screw shaft in a state where the load is applied to the ball nut by the load applying section. A control unit and a recording unit for recording the detection result of the detection unit according to the driving amount of the screw shaft while the driving amount is changed are provided.

According to this measuring device, by moving the ball nut along the screw shaft while a constant load is applied in the moving direction, rattling between the screw shaft and the ball nut in the moving direction is eliminated. Information for evaluating the accuracy of the ball screw is recorded in this state. The information recorded in this way includes information that can indicate looseness between the screw groove corresponding to the amount of drive of the screw shaft and the ball nut in the entire area of the screw groove of the screw shaft. This makes it possible not only to evaluate the accuracy of the ball screw corresponding to the amount of drive of the screw shaft, but also to evaluate the accuracy of the ball screw over the entire screw shaft. is.

By the way, for a screw shaft such as a ball screw, it is required that dimensions such as pitch and effective diameter of the screw groove are within a predetermined allowable range. However, the above-described conventional ball screw measuring device measures the ball nut screwed to the screw shaft, and measures the operating accuracy of the screwed relationship between the screw shaft and the ball nut. Therefore, it was impossible to measure the dimensional accuracy of the screw groove as a single screw shaft.

Therefore, conventionally, the pitch and effective diameter of the thread groove have been measured using a general-purpose measuring machine such as a three-dimensional measuring machine installed in a temperature-controlled room or the like.

JP 2016-109483 A

As described above, a screw shaft such as a ball screw is required to have the pitch and effective diameter of its thread groove within a predetermined allowable range. Therefore, if the dimensions of the screw shaft machined through the prescribed process are not within the allowable range, and correction machining is possible, correct the screw shaft so that the dimensions are within the allowable range. There is a need to.

However, once the machined screw shaft is removed from the processing device, the pitch and effective diameter of the thread groove are measured using the above three-dimensional measuring machine, etc., and then the screw shaft is mounted again on the processing device for corrective processing. In the case of performing the correcting process by using a screw shaft, there is a problem that the correcting process cannot be performed with high accuracy due to the mounting accuracy of the screw shaft to the processing device, for example, the center runout. In addition, when correcting the thread groove, it is necessary to reproduce the phase (angular position in the circumferential direction) of attaching the screw shaft to the processing device, but there is also the problem that it takes a long time to make the adjustment.

In such a case, if it is possible to measure the pitch and effective diameter of the machined thread groove on the so-called machine while the screw shaft is attached to the processing device, the The corrective machining can be performed while the shaft is attached to the machining device, and the corrective machining can be performed with high precision and efficiency.

However, conventionally, no measuring device has been provided that can measure the screw shaft in the processing device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a screw shaft measuring method and a measuring device capable of measuring the dimension of a thread groove in a processing apparatus for processing a screw shaft. do.

The present invention for solving the above problems is a method for measuring a screw shaft,
One imaging camera is disposed so as to face the screw shaft, and the optical axis of the imaging camera is located on the outer periphery on one side bordering on the axis of the screw shaft in a plane viewed from the imaging camera side. After arranging the imaging camera so that the lead of the located thread groove and the angle thereof match,
capturing a first image including the entire radial direction of the screw shaft;
Next, after reversing the screw shaft by 180° around the axis, a second image including the entire radial direction of the screw shaft is captured,
Based on the first image, the outline of the thread groove on the one side is extracted, and after calculating the center positions of at least two adjacent thread grooves, the center positions of the adjacent thread grooves along the axis In addition to calculating the pitch, which is the interval in the direction of the one side, extracting the outer peripheral contour corresponding to the outer periphery of the screw shaft located on the other side opposite to the one side across the axis, and extracting the thread groove on the one side Calculate the distance in the radial direction between the center position of and the outer peripheral contour of the other side,
Next, based on the second image, the contour of the thread groove on the other side, which is in line symmetry with the thread groove on the one side about the axis, is extracted, and the center position of the thread groove on the other side is determined. At the same time, extracting the outer peripheral contour corresponding to the outer periphery of the other side of the screw shaft, the distance in the radial direction between the center position of the thread groove on the other side and the outer peripheral contour of the other side is calculated. ,
Next, the obtained radial distance between the center position of the thread groove on the one side and the outer peripheral contour on the other side, and the distance between the center position of the thread groove on the other side and the outer peripheral contour on the other side. It relates to a screw shaft measuring method in which an effective diameter of a screw groove is calculated based on the radial distance between the two.

This threaded shaft measuring method is suitably carried out by a threaded shaft measuring device having the following configuration. That is, this screw axis measuring device
a support portion that supports the screw shaft so as to be rotatable about its axis;
a rotating device that rotates the screw shaft about the axis;
one imaging camera arranged to face the screw shaft;
a control device for controlling the operation of the rotating device and the imaging camera;
a dimension calculation unit that processes the image captured by the imaging camera and calculates the dimension of the screw shaft,
The imaging camera is arranged such that its optical axis is at the same angle as the lead of the thread groove located on the outer periphery on one side bordering on the axis of the screw shaft in a plane viewed from the imaging camera side. is set up,
The control device controls the rotating device to position the screw shaft at an initial position, and operates the imaging camera to capture a first image including the entire radial direction of the screw shaft. processing;
After that, the rotating device is driven to reverse the screw shaft by 180° about the axis, and the imaging camera is operated to obtain a second image including the entirety of the screw shaft in the radial direction. is configured to perform a process of imaging the
Based on the first image, the dimension calculation unit extracts the contour of the thread groove on the one side, calculates the center positions of at least two adjacent thread grooves, and then calculates the centers of the adjacent thread grooves. Calculating a pitch, which is an interval in the direction along the axis between the positions, and extracting an outer circumference contour corresponding to the outer circumference of the screw shaft located on the other side opposite to the one side across the axis, a process of calculating the distance in the radial direction between the center position of the thread groove on the one side and the outer peripheral contour on the other side;
Next, based on the second image, the contour of the thread groove on the other side, which is in line symmetry with the thread groove on the one side about the axis, is extracted, and the center position of the thread groove on the other side is determined. At the same time, extracting an outer peripheral contour corresponding to the outer periphery of the other side of the screw shaft, calculating the distance in the radial direction between the center position of the thread groove on the other side and the outer peripheral contour of the other side processing;
Next, the obtained radial distance between the center position of the thread groove on the one side and the outer peripheral contour on the other side, and the distance between the center position of the thread groove on the other side and the outer peripheral contour on the other side. and calculating an effective diameter of the thread groove based on the radial distance between the two.

According to the screw shaft measuring method and the screw shaft measuring device of this aspect (first aspect), the first image of the entire radial direction of the screw shaft captured by one imaging camera disposed so as to face the screw shaft Since the pitch and effective diameter of the thread groove are calculated by the dimension calculator based on the image and the second image, the pitch and effective diameter of the thread groove can be calculated in a non-contact manner. .

Since the screw shaft measuring device configured as described above can be incorporated into an NC machine tool for processing a screw shaft, it is possible to immediately measure the dimensions of the screw shaft after processing in the NC machine tool. . Thus, by measuring the dimension of the screw shaft in the NC machine tool in this way, if the thread groove is not finished to the predetermined dimension, if it can be corrected, after the measurement, the NC Corrective machining can be performed immediately in the machine tool, and by doing so, a high-precision screw shaft can be efficiently manufactured.

The present invention also provides a method for measuring a screw shaft, comprising:
Two imaging cameras, first and second, are arranged so as to face the screw shaft and have their optical axes parallel to each other. After arranging them side by side at a predetermined interval so that the angle of the lead of the thread groove located on the outer peripheral portion on one side of the axis of the screw shaft is the same,
The first image capturing camera captures a first image including the thread groove on the one side, and the second image capturing camera captures the image on the other side opposite to the one side across the axis. capturing a second image including the located thread groove;
Next, after reversing the screw shaft by 180° around the axis, a third image including the thread groove on the other side rotated to the region on the one side by the first imaging camera and
Based on the first image, the outline of the thread groove on the one side is extracted, and after calculating the center positions of at least two adjacent thread grooves, the center positions of the adjacent thread grooves along the axis The distance in the radial direction of the screw shaft between the first reference position preset in the first image and the center position of the thread groove on the one side is calculated. calculate,
Based on the second image, an outer circumference contour corresponding to the outer circumference of the screw shaft located on the other side is extracted, and a second reference position preset in the second image and the outer circumference of the other side are extracted. calculating the distance in the radial direction between the contour,
Based on the third image, the contour of the thread groove on the other side is extracted, the center position of the thread groove on the other side is calculated, and the outer circumference contour corresponding to the outer circumference of the screw shaft on the other side is calculated. extracting and calculating the distance in the radial direction of the screw shaft between the center position of the thread groove on the other side and the outer peripheral contour on the other side;
Next, the radial distance between the obtained first reference position and the center position of the thread groove on the one side, the diameter between the second reference position and the outer peripheral contour on the other side, and the distance in the direction, the radial distance between the center position of the thread groove on the other side and the outer peripheral contour on the other side, and the distance between the first reference position and the second reference position obtained in advance A screw shaft measuring method for calculating an effective diameter of a screw groove based on the radial distance of the above.

This threaded shaft measuring method is suitably carried out by a threaded shaft measuring device having the following configuration. That is, this screw axis measuring device
a support portion that supports the screw shaft so as to be rotatable about its axis;
a rotating device that rotates the screw shaft about the axis;
two imaging cameras, first and second, facing the screw shaft and arranged such that their optical axes are parallel to each other;
a control device for controlling the operation of the rotating device and the imaging camera;
a dimension calculation unit that processes the image captured by the imaging camera and calculates the dimension of the screw shaft,
In the plane viewed from the imaging camera side, both optical axes of the first and second imaging cameras are located on the outer periphery on one side of the axis of the screw shaft. arranged side by side at predetermined intervals so as to match,
The control device controls the rotating device to position the screw shaft at an initial position, and operates the first imaging camera to capture a first image including the thread groove on the one side. A process of capturing an image and operating the second image capturing camera to capture a second image including the thread groove located on the other side opposite to the one side across the axis;
After that, the rotating device is driven to reverse the screw shaft by 180° around the axis, and the first imaging camera is operated to rotate the screw shaft to the one side region. and a process of capturing a third image including the thread groove on the other side,
Based on the first image, the dimension calculation unit extracts the contour of the thread groove on the one side, calculates the center positions of at least two adjacent thread grooves, and then calculates the centers of the adjacent thread grooves. A pitch, which is an interval in the direction along the axis of the positions, is calculated, and the screw axis between a first reference position preset in the first image and the center position of the thread groove on the one side. A process of calculating the distance in the radial direction of
Next, based on the second image, an outer circumference contour corresponding to the outer circumference of the screw shaft located on the other side is extracted, and a second reference position preset in the second image and the other side are extracted. A process of calculating the distance in the radial direction between the outer peripheral contour;
Based on the third image, the contour of the thread groove on the other side is extracted, the center position of the thread groove on the other side is calculated, and the outer circumference contour corresponding to the outer circumference of the screw shaft on the other side is calculated. a process of extracting and calculating the distance in the radial direction between the center position of the thread groove on the other side and the outer peripheral contour on the other side;
Then, the distance between the obtained first reference position and the center position of the thread groove on the one side, the radial distance between the second reference position and the outer peripheral contour on the other side, and the radial distance between the center position of the thread groove on the other side and the outer peripheral contour on the other side, and the radial distance between the first reference position and the second reference position obtained in advance and calculating the effective diameter of the thread groove based on the distance of .

In the screw shaft measuring method and screw shaft measuring device of this aspect (second aspect) as well, the first and second images of the screw shaft captured by the first and second imaging cameras arranged to face the screw shaft are provided. Based on the first image, the second image and the third image, the pitch and effective diameter of the thread groove are calculated by the dimension calculating unit, so that the pitch and effective diameter of the thread groove can be calculated in a non-contact manner. can be calculated.

Since the screw shaft measuring device of the second aspect can also be incorporated in an NC machine tool for processing a screw shaft, the dimension of the screw shaft after processing can be immediately measured in the NC machine tool. If the thread groove is not finished to the prescribed dimensions, and if it can be corrected, it can be corrected within the NC machine tool immediately after the measurement. Thus, by doing so, a high-precision screw shaft can be efficiently manufactured.

The screw shaft measuring method and the screw shaft measuring apparatus of the second aspect can cope with the case where the diameter of the screw shaft is large and a single imaging camera cannot capture the entire image of the screw shaft in the radial direction. and is particularly useful in this case.

Moreover, in the present invention, in the above-described first and second aspects, it is preferable that the imaging portion of the screw shaft imaged by the imaging camera is illuminated by an illumination device. By illuminating the imaging region in this way, a clear image can be obtained, and the pitch and effective diameter of the thread groove can be calculated with high accuracy.

Further, in the present invention, it is preferable that the lighting device is configured to illuminate the image pickup part from a direction opposite to the image pickup direction of the image pickup camera. By illuminating in this manner, a clearer contour image can be acquired, and the pitch and effective diameter of the thread groove can be calculated with higher accuracy.

As described above, according to the screw shaft measuring method and the screw shaft measuring apparatus of the present invention, the dimension calculator calculates the Since the pitch and effective diameter of the thread groove are calculated, the pitch and effective diameter of the thread groove can be calculated in a non-contact manner.

In addition, since the screw shaft measuring device according to the present invention can be incorporated into an NC machine tool that processes a screw shaft, it is possible to immediately measure the dimensions of the screw shaft after processing in the NC machine tool. By measuring the dimension of the screw shaft in the NC machine tool in this way, if the thread groove is not finished to the predetermined dimension, if it can be corrected, after the measurement, the NC machine tool Corrective machining can be performed immediately inside the screw shaft, and by doing so, a high-precision screw shaft can be efficiently manufactured.

1 is a perspective view showing the main configuration of a multitasking machine according to one embodiment of the present invention; FIG. FIG. 5 is an explanatory diagram for explaining a method for machining a screw shaft by the multitasking machine according to the present embodiment; FIG. 5 is an explanatory diagram for explaining a method for machining a screw shaft by the multitasking machine according to the present embodiment; FIG. 4 is an explanatory view seen from the direction of arrow A in FIG. 3; It is a sectional view showing a grinding unit concerning this embodiment. Fig. 2 is a perspective view showing a housing device for a grinding unit according to the embodiment; It is an explanatory view for explaining how to use the grinding unit according to the present embodiment. It is an explanatory view for explaining how to use the grinding unit according to the present embodiment. It is an explanatory view for explaining operation of a storage device concerning this embodiment. It is an explanatory view for explaining operation of a storage device concerning this embodiment. It is the perspective view which showed the anti-vibration unit which concerns on this embodiment. FIG. 12 is a cross-sectional view in the direction of arrows BB in FIG. 11; 12 is a perspective view seen from the direction of arrow C in FIG. 11; FIG. It is the perspective view which showed the chuck|zipper which concerns on this embodiment. 4 is a perspective view showing gripping claws of the chuck according to the embodiment; FIG. It is an explanatory view for explaining operation of a chuck concerning this embodiment. FIG. 4 is a perspective view showing a cover body that houses the sizing device according to the present embodiment; It is a perspective view showing a part of the sizing device according to the present embodiment. 1 is a cross-sectional plan view showing a sizing device according to the present embodiment; FIG. 1 is a front cross-sectional view showing a sizing device according to the present embodiment; FIG. It is the perspective view which showed the part in which the rotary dresser which concerns on this embodiment is provided. FIG. 5 is an explanatory diagram for explaining shape correction of a grinding wheel using the rotary dresser according to the present embodiment; FIG. 5 is an explanatory diagram for explaining shape correction of a grinding wheel using the point dresser according to the present embodiment; FIG. 5 is an explanatory diagram for explaining shape correction of a grinding wheel using the point dresser according to the present embodiment; It is an explanatory view for explaining a processing method using a grinding wheel concerning this embodiment. 1 is a perspective view showing a state in which a screw shaft measuring device according to this embodiment is placed at a measuring position; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing for demonstrating the structure of the screw shaft measuring device which concerns on this embodiment. It is a block diagram showing the configuration of the screw shaft measuring device according to the present embodiment. It is an explanatory view for explaining a measuring method in a screw axis measuring device concerning this embodiment. FIG. 5 is an explanatory diagram for explaining a measuring method in a screw shaft measuring device according to another embodiment of the present invention;

An embodiment of the present invention will be described below with reference to FIGS. 1 to 29. FIG. FIG. 1 is a perspective view showing the main configuration of a multitasking machine of this example, which is an NC machine tool configured to be able to machine screw shafts. In the following description, a screw shaft of a ball screw is described as an object to be machined, but an object that can be machined by the multitasking machine of this example is not limited to this. In particular, as the screw shaft, various screw shafts such as a trapezoidal screw can be processed in addition to the ball screw. Moreover, below, the material for manufacturing a screw shaft is called a shaft-shaped work.

A multi-tasking machine 1 of this example comprises a multi-tasking machine 2 , a control device 3 , a sizing device 90 and a screw axis measuring device 110 . The details of each unit will be described below.
[Multitasking machine]
<Basic configuration of multitasking machine>
The multitasking machine 2 includes a bed (not shown) and a column (not shown) movably disposed on the bed (not shown) in the Z-axis direction shown in FIG. , a first headstock 8, a second headstock 10, and a tool post 15, which are also arranged on a bed (not shown). It has a storage device 60 and the like arranged above.

<Tool Spindle>
The column (not shown) holds a quill 6 movably in the X-axis and Y-axis directions. Various tools are attached. The grinding unit 40 is housed in the housing device 60, and is attached to and detached from the tool spindle 7 by a predetermined operation. Tools other than the grinding unit 40 are stored in a tool magazine (not shown) provided at an appropriate position. Attachment/detachment to/from the tool spindle 7 is performed by (not shown). Also, the tool spindle 7 is held by the quill 6 so as to be rotatable around a rotation axis parallel to the Y-axis.

<Headstock>
The first headstock 8 rotatably holds the first main spindle 9 and is equipped with a drive motor for rotating the first main spindle 9 inside. and a drive motor for rotating the second main shaft 10 is provided inside. The first headstock 8 and the second headstock 10 face each other, and are arranged so that the axes of the first and second spindles 9 and 11 are coaxial. It can move forward and backward in the Z-axis direction with respect to the first headstock 8 .

<Chuck>
A first chuck 20 is mounted on the first spindle 9, and a second chuck 25 is mounted on the second spindle 11. By these first and second chucks 20 and 25, the axial workpiece W is grasp the The first chuck 20 and the second chuck 25 have the same structure. Therefore, hereinafter, the configuration of the first chuck 20 will be described as a representative, and the corresponding components of the second chuck 25 will be given the reference numerals in parentheses.

As shown in FIG. 14, the first chuck 20 (25) includes a chuck body 21 (26) and a tailstock shaft 24 provided at the center of the chuck body 21 (26) so as to protrude from the front end surface of the chuck body 21 (26). (29) and three gripping claws 22 (27) equally spaced in the circumferential direction so as to protrude from the front end face of the chuck body 21 (26). The gripping claws 22 (27) are configured to advance and retreat in the direction along the central axis of the chuck body 21 (26) by a drive mechanism (not shown), and advance to the advance end when advanced (closed). Afterwards, it swings in a direction approaching the central axis to grip the shaft-like work W, and when retreating (opening), it swings radially outward from the central axis to grasp the shaft-like work W. After releasing the grip of W, it is configured to retract to the retraction end in the direction along the central axis.

Thus, according to the first chuck 20 (25), the gripping claws 22 (27) oscillate toward the central axis of the chuck body 21 (26), thereby moving the shaft-like workpiece W to the chuck body 21. It is gripped so as to be pulled toward the end face side of (26). By such a gripping operation, it is possible to machine the shaft-shaped workpiece W with high dimensional accuracy.

The gripping surface 23 (28) of each of the gripping claws 22 (27) is formed in an arcuate shape according to the outer diameter of the shaft-shaped work W to be gripped, and is successively moved away from the end surface of the chuck main body 21 (26). It consists of a plurality of gripping surfaces (in this example, four gripping surfaces 23a-23d (28a-28d)) provided at shifted positions. The gripping surfaces 23a-23d (28a-28d) are inclined radially outward with respect to the central axis of the chuck body 21 (26) when the gripping claws 22 (27) are in the open state. , the gripping surface 23a (28a) closest to the end surface of the chuck body 21 (26) has the smallest inclination angle with respect to the central axis of the chuck body 21 (26), and is the gripping surface farther from the end surface of the chuck body 21 (26). The angle of inclination is set larger as the angle increases, and the angle of inclination of the farthest gripping surface 23d (28d) is the largest.

The gripping surfaces 23a to 23d (28a to 28d) have different curvatures in order in the direction away from the end surface of the chuck body 21 (26), and the gripping surface 23a closest to the end surface of the chuck body 21 (26). (28a) has the smallest curvature, and the curvature increases with the distance from the end surface of the chuck book 21 (26), and the farthest gripping surface 23d (28d) has the largest curvature. .

Thus, in the first chuck 20 and the second chuck 25 of this example having the above configurations, one type of gripping claws 22 and 27 can grip four shaft-shaped workpieces W having different outer diameters. According to the first chuck 20 and the second chuck 25, the number of gripping claws to be prepared can be reduced compared to the conventional art. The cost can be reduced, the complexity of the management can be eased, and efficient operation can be performed. In addition, since the number of times of replacing the gripping claws 22 (27) according to the outer diameter of the shaft-shaped work W is reduced, the setup time can be reduced, and the machining time can be shortened accordingly.

In the first chuck 20 and the second chuck 25, the tip of the tailstock shafts 24 and 29 are inserted into the center holes drilled in both end surfaces of the shaft-like work W, thereby moving the shaft-like work W. In the held state, the gripping claws 22 and 27 can grip the ends of the shaft-shaped work W. As shown in FIG.

As shown in FIGS. 23 and 24, a first point dresser 32 and a second point dresser 33 are attached to the end surface of the first chuck 20 near the outer periphery. The first point dresser 32 is arranged so that its shaft portion is inclined toward the central axis of the first chuck 20 , and the second point dresser 33 has its shaft portion extending radially outward of the first chuck 20 . The shape of the grinding wheel _TG is modified by a diamond provided at the tip of each shaft.

The grinding wheel _TG of this example has a structure in which a grindstone portion is formed at the tip of a shaft portion. The first point dresser 32 corrects the shape of the reverse tapered portion Gb, and the second point dresser 33 corrects the shape of the forward tapered portion Ga. As shown in FIG. 25, this grinding wheel _TG can grind the outer peripheral surface of the shaft-shaped work W using the forward taper portion Ga, and grind the end surface of the shaft-shaped work W using the reverse taper portion Gb. Can be ground.

Thus, in this example, the first point dresser 32 and the second point dresser 33 are arranged on the end face near the outer periphery of the first chuck 20, and the region on the end face side of the first chuck is normally interfered with. Since it is set in an area where the tool cannot be inserted during machining using the grinding wheel TG, the tool post is set in the area when performing other machining other than grinding using the grinding wheel _TG . 15, it is possible to reliably prevent the components such as the tool spindle 7 and other tools from interfering with the first point dresser 32 and the second point dresser 33 .

When processing the end of the shaft-shaped work W gripped by the gripping claws 22 of the first chuck 20, if the gripping claws 22 and the grinding wheel _TG interfere with each other, the gripping claws 22 must be moved to the retracted end. By retreating, the gripping claws 22 and the grinding wheel _TG do not interfere with each other, so that the end portion can be processed. Similarly, when the end portion of the shaft-shaped work W gripped by the gripping claws 27 of the second chuck 25 is processed, if the gripping claws 27 and the grinding wheel _TG interfere with each other, the gripping claws 27 are moved to the retracted end. By retracting the gripping claw 27 and the grinding wheel _TG to a state in which they do not interfere with each other, the end can be processed.

<Tool post>
As shown in FIG. 1, the tool post 15 is movable in the X-axis direction, the Z-axis direction, and the Y'-axis direction. A turret 16 is held rotatably about a rotation axis. The turret 16 is composed of a polygonal cylinder having a planar mounting surface on its peripheral surface, and as shown in FIGS. Note that the Y'-axis is inclined at a predetermined angle with respect to the Y-axis so as to fall forward toward the operating side. Further, the tool post 15 is designed to move in the Y-axis direction (horizontal direction) by a combined movement of the X-axis direction movement and the Y'-axis direction movement.

<Stabilizer unit>
As shown in FIGS. 11 and 13, the anti-vibration unit 70 includes a set of anti-vibration devices 72, a connecting plate 71 that connects the anti-vibration devices 72 with appropriate spacing, and the anti-vibration device 72. and a pressurized fluid supply source for supplying pressurized fluid, and the set of anti-vibration devices 72 are arranged along the Z-axis. 11, illustration of the shaft-like workpiece W is omitted.

As shown in FIG. 12, the anti-vibration device 72 includes a base 73, a receiving member 74 provided on the base 73, and a pressing member provided above the receiving member 74 so as to face it. 75 , a clamping mechanism 77 that supports the pressing member 75 and moves the pressing member 75 into and out of contact with the receiving member 74 .

The receiving members 74 of the set of anti-vibration devices 72 each have a V-shaped groove 74a on the upper surface, and the set of anti-vibration devices 72 are arranged so that the V-shaped grooves 74a of each of the receiving members 74 have bottom striations. are attached to the connecting plate 71 with a predetermined space therebetween so that they are positioned on the same line. The anti-vibration unit 70 is attached to the turret 16 so that the bottom line of the V-shaped groove 74a of the receiving member 74 is parallel to the Z-axis. In addition, the holding member 75 has a V-shaped groove 75a on the lower surface facing the receiving member 74, which coincides with the V-shaped groove 74a of the receiving member 74, that is, the bottom line is aligned vertically. It is Further, a guide hole 73a is formed in the base 73 at a predetermined distance from the receiving member 74, and the upper end of the guide hole 73a is connected to the lower surface of the pressing member 75 to provide a guide pin. 76 is inserted.

The clamping mechanism 77 has a cylinder hole 78 formed between the guide hole 73a and the receiving member 74 so as to open to the upper surface of the base 73, and is inserted into the cylinder hole 78, and the upper end of the cylinder hole 78 is inserted. A pressure fluid supply portion (see FIG. not shown). Thus, in the clamping mechanism 77, the pressure fluid is supplied to the pressure fluid chamber 78a so that the piston 79 and the pressing member 75 connected thereto are lowered, and the shaft-like workpiece W is clamped to the V-shape of the receiving member 74. It is clamped by the receiving member 74 and the pressing member 75 while being in contact with the two inner surfaces of the V-shaped groove 74a and the two inner surfaces of the V-shaped groove 75a of the pressing member 75, and the pressure fluid is supplied to the pressure fluid chamber 78b. By supplying the piston 79 and the pressing member 75, the clamping of the axial work W by the receiving member 74 and the pressing member 75 is released, that is, unclamped. At this time, since a guide pin 76 is inserted into the guide hole 73a, the vertical motion of the piston 79 is guided by the guide pin 76, so that the piston 79 and the pressing member 75 can be smoothly moved up and down. can. Compressed air or pressure oil can be used as the pressure fluid.

A mounting plate 80a is erected on the upper surface of the base 73 at a position opposite to the receiving member 74 across the cylinder hole 78 and the guide hole 73a. A holding plate 80b is fixed above the pressing member 75 so as to be parallel thereto. Between the holding plate 80b and the pressing member 75, the position where the piston 79 is connected, the position corresponding to the V-shaped groove 75a of the pressing member 75, and the position where the guide pin 76 is connected are: A spring body 81 (first biasing member), a spring body 82 (second biasing member), and a spring body 83 (third biasing member) are provided to bias the pressing member 75 toward the receiving member 74 side. . In this way, since the clamping force of the piston 79 and the urging forces of the spring bodies 81, 82, and 83 act on the pressing member 75, the shaft-like workpiece W is moved with a stronger force to the receiving member 74 and the pressing member. It is sandwiched by members 75 .

In addition, the receiving member 74 and the pressing member 75 have one side surface along the V-shaped grooves 74a and 75a, respectively, which is positioned further than the radial end of the clamped shaft-shaped work W when viewed from above. It is located on the axial side of the axial work W.

<Grinding unit>
As shown in FIG. 5, the grinding unit 40 includes a rotating shaft 45, a housing 41 that rotatably supports the rotating shaft 45 with one end thereof extending outside, and a rotating shaft. 45, a rotor 49 mounted on the rotating shaft 45, a stator 50 held by the housing 41 so as to be positioned radially outward of the rotor 49, and the like. consists of The rotor 49 and the stator 50 constitute a drive motor, and the rotor 49, the rotary shaft 45 to which the rotor 49 is attached, and the thread groove grinding wheel 55 attached to the rotary shaft 45 are driven by electric power supplied from the outside. Rotate. A cable protected by a flexible protection tube 56 is connected to the stator 50, and power is supplied to the stator 50 through this cable (see FIGS. 6 to 8, etc.).

The housing 41 comprises a body portion 42 into which the stator 50 is inserted, and annular members 43 and 44 attached to both ends of the body portion 42 and holding the bearings 46, respectively. Lids 47a and 47b are fitted on a rotary shaft 45 extending outward from the annular member 44, and a first clamping member 54 is fitted onto the end of the rotary shaft 45. A thread groove grinding grindstone 55 is held by a second holding member 53 connected to the end of the rotating shaft 45 together with the holding member 54 . A cover body 48 is provided on the end surface of the annular member 43 .

A first held portion 51 for mounting the grinding unit 40 on the tool spindle 7 is provided on the outer surface of the main body portion 42 , and the main body portion 42 on the side opposite to the first held portion 51 is provided. A second held portion 52 is provided on the outer surface. In FIG. 5, illustration of the cross section of the second held portion 52 is omitted.

By the way, as shown in FIG. An eddy current sensor 31 is provided to detect the thread grinding wheel 55 when it is at a correction position for correcting the shape. is detected.

Thus, the grinding unit 40 is moved to a position where the axis of the rotary shaft 45 coincides with the axis of the rotary dresser 30 in the X-axis direction, and then the grinding unit 40 is moved in the Z-axis direction so that the grinding unit 40 is positioned at a position detected by the eddy current sensor 31, and then moved in the Y-axis direction so as to approach the rotary dresser 30, so that the outer peripheral surface of the rotating thread groove grinding wheel 55 is also rotated. By abutting on the outer peripheral surface of the rotary dresser 30, the shape of the grinding action surface, which is the outer peripheral surface of the thread groove grinding wheel 55, can be corrected.

This grinding unit 40 is housed in a housing device 60 shown in FIGS. It is attached to the tool spindle 7 .

<Accommodation device>
The accommodation device 60 is arranged above the second headstock 10, as shown in FIG. As shown in FIGS. 1 and 6 to 10, the housing device 60 includes a housing body 61 having an opening for inserting and removing the grinding unit 40 and having a space for housing the grinding unit 40 therein; It is composed of a cover 63 for opening and closing the opening of the body 61, an opening/closing mechanism 62 disposed in the container 61, a forward/backward mechanism 67, a pulley 65, a slide/biasing portion 66, a locking member 69, and the like. .

The advance/retreat mechanism 67 includes a tool holding portion 67a as a holding mechanism that detachably holds the grinding unit 40 via the second held portion 52 of the grinding unit 40, and the tool holding portion 67a as the holding body. 6 and 9) and the removal position (see FIGS. 7 and 10) set outside the container 61. and an air cylinder 67b that advances and retreats in the direction. As shown in FIG. 10, the grinding unit 40 has the thread groove grinding wheel 55 on the upper side, the second held portion 52 is located on the housing body 61 side, and the first held portion 51 is housed. It is held by the tool holding portion 67a in a posture located on the opposite side of the body 61. As shown in FIG. The air cylinder 67b is connected to an appropriate compressed air supply source provided outside, and compressed air pressurized from this compressed air supply source is supplied to the air cylinder 67b.

The slide/biasing portion 66 is arranged with its longitudinal direction along the Z-axis, holds the pulley 65 movably in the Z-axis direction, and presses the enclosed compressed air (pressure fluid). The action is configured to bias the pulley 65 toward the side opposite to the opening. The protective tube 56 connected to the grinding unit 40 is wound around the pulley 65, and the other end of the protective tube 56 is secured by a locking member 69a provided in the container 61. The intermediate portion thereof is inserted through a guide ring 69b provided above the locking member 69a with the slide/biasing portion 66 interposed therebetween.

9 and 10, the opening/closing mechanism 62 includes an air cylinder (not shown) whose longitudinal direction is arranged along the Z-axis, and an air cylinder (not shown). ) and a link portion (not shown) connected to the connecting portion 63a of the lid 63. When the piston rod 62a advances, the lid 63 opens and the piston rod 62a The lid body 63 is closed by retreating. The air cylinder (not shown) is connected to the compressed air supply source, and pressurized compressed air is supplied to the air cylinder (not shown) from the compressed air supply source.

According to this storage device 60, as shown in FIGS. 6 and 7, the grinding unit 40 is held by the tool holding portion 67a of the advancing/retreating mechanism 67 while the second held portion 52 is held by the holding portion 67a of the advance/retreat mechanism 67. housed in a stowed position within. When the tool holding portion 67a is at the accommodation position, the slide/biasing portion 66 moves the pulley 65 to the retracted end opposite to the opening by its biasing force. As a result, the protection tube 56 is accommodated in the accommodation body 61 together with the grinding unit 40 while being wound around the pulley 65 without slack.

[Sizing device]
The sizing device 90, as shown in FIGS. 17-20, is housed in a cover body 107 which is disposed along the first headstock 8 and has a storage area isolated from the machining area. The cover body 107 has an opening that is opened and closed by a lid body 108, and the lid body 108 is driven by an appropriate driving source (not shown) such as an air cylinder to open and close the opening.

The sizing device 90 is composed of a measuring head 91 and a transfer device 93 for moving the measuring head 91 in and out through the opening of the cover body 107 . The measuring head 91 has two probes 92 urged to approach each other, and the two probes 92 come into contact with the outer peripheral surface of the shaft-shaped work W to move the shaft-shaped work W outside. configured to measure diameter;

The transfer device 93 transfers the measuring head 91 to bring its probe 92 into contact with the outer peripheral surface of the shaft-shaped work W, holds the measuring head 91 , and moves the measuring head 91 along the axis of the first main shaft 9 . A turning mechanism 103 that turns about an axis parallel to the shaft-shaped work W in a direction (arrow E direction) to approach the shaft-shaped work W and a direction to move away from the shaft-shaped work W (arrow F direction), and this turning mechanism and a linear transfer mechanism 94 for advancing and retreating the 103 in the direction along the axis of the first main shaft 9 (the Z-axis direction).

The linear transfer mechanism 94 includes an L-shaped frame 95 in a plan view having an orthogonal portion 95a perpendicular to the axis of the first main shaft 9 and a parallel portion 95b parallel to the axis of the first main shaft 9; Two guide rails 96 arranged parallel to the Z-axis on the portion 95b, a slider 97 engaged with each guide rail 96 and moving along the guide rail 96, and these sliders 97 on the slider 97. a base 98 attached so as to straddle the base 98, a pair of brackets 99 and 100 erected on the base 98 at a predetermined interval in the Z-axis direction, and the back surface of the orthogonal portion 95a of the frame 95 ( and a support plate 101 attached to the surface opposite to the parallel portion 95b, and an air piston rod 102a attached to the support plate 101 and connected to the base 98 through the orthogonal portion 95a. It is composed of a cylinder 102 and the like.

The turning mechanism 103 includes a turning arm 105 that supports the measuring head 91 so that the plane including the contact portions of the two probes 92 with respect to the shaft-shaped work W is orthogonal to the axis of the first spindle 9, and an axis is arranged along the axis of the first main shaft 9, and the rotary arm 105 is connected to the outer peripheral surface of the front end portion, and the rotary shaft 104 is rotatably held by the bracket 99; and an actuator 106 attached and connected to the rotating shaft 104 to rotate the rotating shaft 104 . The actuator 106 is operated by externally supplied compressed air to rotate the rotary shaft 104 in the direction of arrows EF, so that the probe 92 of the measuring head 91 contacts the outer peripheral surface of the shaft-shaped work W. It is turned and moved between the measurement position and the retracted position away from the axial work W. - 特許庁The measuring head 91 is stored in the cover body 107 in a state of turning to the retracted position.

Thus, according to the sizing device 90, the air cylinder 102 of the linear transfer mechanism 94 is driven in a state in which the opening of the cover body 107 is opened by driving the cover body 108 by a suitable drive source (not shown). is driven to move the base 98 forward, the swivel mechanism 103 and the measuring head 91 supported by it advance from the opening of the cover body 107 and move to the swivel position within the processing area. When the actuator 106 is driven to rotate the measuring head 91 to the measurement position in the direction of arrow E, the probe 92 comes into contact with the outer peripheral surface of the shaft-shaped work W to measure the outer diameter of the shaft-shaped work W. It becomes possible.

After the outer diameter measurement of the shaft-shaped workpiece W is completed, the actuator 106 of the turning mechanism 103 is driven to turn the measuring head 91 to the retracted position in the direction of the arrow F, and then the linear transfer mechanism 94 moves the air When the cylinder 102 is driven to retract the base 98, the swivel mechanism 103 and the measuring head 91 supported by it are retracted from the swivel position to the standby position within the cover body 107. FIG. By closing the opening of the cover body 107 with the lid body 108, the storage area in the cover body 107 is isolated from the processing area.

Since the sizing device 90 is stored in the cover body 107 having a storage area isolated from the machining area when not in use, the sizing apparatus 90 may be damaged by the coolant liquid used during other machining and chips generated at that time. It is possible to prevent the sizing device 90 from being soiled, and also to prevent inconveniences such as interference between the sizing device 90 and the tools used in the other processing. can.

[Screw axis measuring device]
As shown in FIGS. 26 and 28, the thread axis measuring device 110 is disposed so as to face the shaft-shaped work W having the thread grooves at the measurement position and the optical axes thereof are parallel to each other. a first imaging camera 111 and a second imaging camera 112, a first lighting device 113 that illuminates an imaging region from a direction opposite to the imaging direction of the first imaging camera 111 and the second imaging camera 112 with the screw shaft W interposed therebetween; A measurement unit composed of a second lighting device 114, a frame 115 that holds the first and second imaging cameras 111 and 112 and the first and second lighting devices 113 and 114, the first imaging camera 111 and Based on the image data captured by the image input unit 116 that captures the image captured by the second imaging camera 112, the measurement operation control unit 117 that controls capture of this image input unit 116, and the image input unit 116, the screw and a dimension calculator 118 for calculating the dimension of the threaded portion of the shaft W. In the following description, the shaft-shaped workpiece W having the thread grooves is particularly referred to as a "screw shaft W".

The image input unit 116, the measurement operation control unit 117, and the dimension calculation unit 118 are constructed within the control device 3. The control device 3 includes a multi-tasking machine control unit for controlling the operation of the multi-tasking machine 2 4 is provided. Also, the dimensions calculated by the dimension calculator 118 are output to the output device 5, for example, a display provided on the control panel.

The control device 3 is composed of a computer including a CPU, RAM, ROM, etc., and the multifunction machine control section 4, the image input section 116, the measurement operation control section 117, and the dimension calculation section 118 are controlled by computer programs. function is realized.

The first imaging camera 111 and the second imaging camera 112 are positioned on the outer periphery on one side bordering on the axis of the screw shaft W in the plane viewed from the first imaging camera 111 and the second imaging camera 112 side. They are arranged side by side at predetermined intervals so that the angles of the leads of the screw grooves and the angles of both optical axes are the same (see FIG. 27). FIG. 27 is a front view showing the relationship between the screw shaft W, the first and second imaging cameras 111 and 112, and the first and second lighting devices 113 and 114. FIG. As shown in the figure, the illumination optical axes of the first and second lighting devices 113 and 114 are aligned with the imaging optical axes of the first and second imaging cameras 111 and 112, respectively.

Then, the measurement operation control unit 117 controls the rotation of the first main shaft 9 and the second main shaft 11 of the multi-tasking machine 2 via the multi-tasking machine control unit 4 to set the screw axis W to the initial rotational position. After indexing to the set angular position, the first image including the thread groove on one side is input from the first image capturing camera 111 via the image input unit 116, and the screw groove is input from the second image capturing camera 112. A process of inputting a second image including thread grooves positioned on the other side opposite to the one side with respect to the axis W is performed.

FIG. 29A shows the first image and the second image to be input. The first image captured by the first imaging camera 111 is the upper image, and the second image captured by the second imaging camera 112 The second image captured is the lower image. In addition, FIG. 29(a) shows the outline of the screw shaft W, respectively. Since the optical axis of the first imaging camera 111 coincides with the lead angle of the thread groove on the one side, the contour image of the thread groove in the first image is an accurate contour image corresponding to the cross section of the thread groove. It's becoming On the other hand, the contour image of the thread groove in the second image is an image in which the contour of the thread groove is distorted because the optical axis of the second imaging camera 112 does not match the lead angle of the thread groove on the other side. .

Next, the measurement operation control unit 117 rotates the first main shaft 9 and the second main shaft 11 of the multi-tasking machine 2 via the multi-tasking machine control unit 4 to rotate the screw shaft W around its axis. After reversing by 180°, a process of inputting a third image including the screw groove on the other side rotated to the region on the one side from the first imaging camera 111 via the image input unit 116 to run. A third image (outline of the screw shaft W) captured by the first imaging camera 111 is shown in FIG. 29(b). By rotating the thread groove on the other side by 180° to the region on the one side, the optical axis of the first imaging camera 111 and the lead angle of the thread groove on the other side are aligned. The contour image of the thread groove on the other side in the third image is a contour image corresponding to an accurate cross section of the thread groove.

After extracting the outline of the thread groove on one side based on the first image captured as described above, the dimension calculation unit 118 calculates the center positions of at least two adjacent thread grooves. , calculating the pitch, which is the interval in the direction along the axis between the center positions of the adjacent thread grooves, and calculating the first reference position preset in the first image and the center position of the thread groove on the one side; and the distance in the radial direction of the screw axis W is calculated.

In FIG. 29(a), the first image captured by the first imaging camera 111 is represented by a coordinate system with the Ya axis-Za axis as the reference axis, and the origin of this Ya axis-Za axis coordinate system is It is the first reference position and coincides with the imaging optical axis of the first imaging camera 111 . The Ya-axis coincides with the radial direction of the screw shaft (the Y-axis), and the Za-axis coincides with the longitudinal direction of the screw shaft (the Z-axis). The dimension calculator 118 calculates the center positions (Ya ₁ , Za ₁ ) and (Ya ₂ , Za ₂ ) of each thread groove from the extracted contour shape of the thread groove, and then calculates the Z of the center position of the adjacent thread groove. The axial distance is calculated as a pitch P (=Za ₂ -Za ₁ ). Then, the dimension calculator 118 assigns the calculated Ya ₁ (=Ya ₂ ) value as the distance between the first reference position and the center position of the thread groove on one side.

Next, the dimension calculator 118 extracts an outer circumference contour corresponding to the outer circumference of the screw shaft W located on the other side based on the second image captured as described above, and calculates the second image. Processing is performed to calculate the distance in the radial direction of the screw shaft W, which is the distance between a preset second reference position in the image and the outer peripheral contour on the other side.

In FIG. 29A, the second image captured by the second imaging camera 112 is represented by a coordinate system with the Yb axis-Zb axis as the reference axis, and the origin of this Yb axis-Zb axis coordinate system is the above-mentioned This is the second reference position and coincides with the imaging optical axis of the second imaging camera 112 . The Yb-axis coincides with the radial direction of the screw shaft (the Y-axis), and the Zb-axis coincides with the longitudinal direction of the screw shaft (the Z-axis). The dimension calculation unit 118 calculates _Yb1 , which is the radial position of the extracted thread groove from the outer peripheral contour shape, and calculates Yb1 as the distance between the second reference position and the outer peripheral contour on the other side. Assign a value of ₁ . Yp is the radial distance (axis distance) between the imaging optical axis of the first imaging camera 111 and the imaging optical axis of the second imaging camera 112, and is derived in advance by appropriate calibration. .

Next, the dimension calculator 118 extracts the outline of the thread groove on the other side based on the third image captured as described above, and calculates the center position of the thread groove on the other side. and extracting an outer circumference contour corresponding to the outer circumference of the other side of the screw shaft, and calculating the distance in the radial direction between the center position of the thread groove on the other side and the outer circumference contour of the other side. conduct.

In FIG. 29(b), the third image captured by the first imaging camera 111 is expressed in a coordinate system with the Ya axis-Za axis as the reference axis, as described above. The dimension calculator 118 extracts the contour of the thread groove on the other side in the third image, and calculates the center position (Ya ₃ , Za ₃ ) of the thread groove from the extracted contour shape of the thread groove. , the outer peripheral contour of the other side _{of the} screw shaft W is extracted, and the radial direction (that is, the Ya axis direction) distance Δ (=Ya ₃ -Ya ₄ ) is calculated.

Next, the dimension calculator 118 calculates the radial distance between the obtained first reference position and the center position of the thread groove on the one side, the second reference position and the outer peripheral contour on the other side. and the radial distance between the center position of the thread groove on the other side and the outer peripheral contour on the other side, and the previously obtained first reference position and second reference position Based on the radial distance between and, the effective diameter of the thread groove is calculated.

FIG. 29C is an explanatory diagram for explaining this process in an easy-to-understand manner, in which the second image in FIG. is. That is, in FIG. 29(a), the center position of the other thread groove in the second image is located at a position radially shifted by Δ from the outer peripheral contour. Therefore, as shown in FIG. Calculated by the formula:
D=Ya ₁ +Yp+Yb ₁ +Δ
The dimension calculator 118 calculates the effective diameter D of the thread groove by this calculation formula.

The measuring unit composed of the first and second imaging cameras 111 and 112, the first and second lighting devices 113 and 114, and the frame 115 is controlled by the measuring operation control section 117, and the transfer device is appropriately controlled. is moved between the measurement position and the retreat position set outside the machining area.

According to the multi-tasking apparatus 1 of the present embodiment having the above configuration, under the control of the multi-tasking machine control unit 4, the multi-tasking machine 2 converts the shaft-like workpiece W into the screw shaft W in the following manner. is machined, and the screw shaft W is measured on the multitasking machine 2 under the control of the measurement operation control unit 117 .

[Processing of screw shaft]
First, in this example, as a material for processing the screw shaft W, a long shaft-like work W made of a general material is used. The shaft-like work W has center holes drilled in both end faces, and the surface thereof is preliminarily quenched, and has a set hardness at a predetermined depth in the radial direction. Further, the axial work W is ground at least on the outer peripheral surface where the thread groove is to be formed.

First, both ends of the axial work W are gripped by the first chuck 20 and the second chuck 25 . At this time, the tailstock shafts 24 and 29 of the first chuck 20 and the second chuck 25 are pressed against the center hole of the shaft-like work W, and the shaft-like work W is supported by the tailstock shafts 24 and 29. Furthermore, it is gripped by the gripping claws 22 and 27 . As described above, the four gripping surfaces 23a to 23d and 28a to 28d having different curvatures are formed on the gripping claws 22 and 27 of the first chuck 20 and the second chuck 25, respectively. Four shaft-like workpieces W having different outer diameters can be gripped by the claws 22 and 27 .

Further, the shaft-shaped work W is clamped from above and below by a set of receiving members 74 and pressing members 75 of a set of anti-vibration devices 72 mounted on the turret 16 . The position of the tool post 15 in the Y'-axis direction is determined by the bottom striated lines of the V-shaped groove 74a of the receiving member 74 and the V-shaped groove 75a of the pressing member 75, the first main shaft 9 and the second main shaft 11. (in other words, the axis of the shaft-like workpiece W) is aligned vertically. In this state, the shaft-shaped work W is gripped by the first chuck 20 and the second chuck 25 and clamped by a set of anti-vibration devices 72 .

Next, as shown in FIG. 2, the shaft-shaped work W is machined for thread grooves using a milling tool _TM which is a rotary cutting tool. In this machining, the axis of the tool spindle 7 is positioned within a plane containing the axis of the axial workpiece W and the X axis, and is inclined at a predetermined angle within this plane, so that the axis of the milling tool _TM is It is performed in a tilted state within the plane. Further, this machining is performed with the machining position between a set of anti-vibration devices 72, and in a state in which the milling tool _TM is cut into the shaft-like workpiece W by a predetermined cutting depth in the X-axis direction, A thread groove is formed in the shaft-like work W by rotating the shaft-like work W at a predetermined rotational speed and moving the milling tool _TM in the Z-axis direction by a predetermined feed amount.

Then, the milling tool _TM is gradually cut into the shaft-like work W in the X-axis direction, and the cutting operation is repeatedly performed to form a thread groove of a predetermined shape in the shaft-like work W. As shown in FIG. At that time, the rotation speed _of the shaft-shaped work W and the feed speed of the milling tool _TM in the Z-axis direction are determined by the pitch of the thread groove to be formed. The feed amount in the axial direction is the same value as the thread groove pitch. As a result, the lead angle of the formed thread groove becomes a predetermined angle.

Also, in synchronism with the movement of the milling tool _TM in the Z-axis direction, the tool post 15, that is, the set of anti-vibration devices 72 is moved in the same movement direction (Z-axis direction) at the same feed rate. Machining using the milling tool _TM involves intermittent cutting, so in the case of a long shaft-shaped work W, there is a risk that vibration or displacement may occur in the shaft-shaped work W. Stable machining can be realized by machining the shaft-shaped work W while it is clamped by the device 72, and as a result, the thread groove can be machined with high accuracy. That is, since the receiving member 74 and the pressing member 5 are each composed of one member and have high rigidity, even if a large cutting load due to intermittent cutting acts on the shaft-shaped work W, no displacement or vibration occurs. , is stably supported by the anti-vibration device 72 . In addition, since the anti-vibration device ₇₂ is moved in synchronism with the movement of the milling tool TM, the vicinity of the machining position of the milling tool _TM can always be supported by the anti-vibration device 72. In this sense, can also support the axial work W in a stable state.

Thread grooving using this milling tool _TM consists of roughing and finishing _. of milling tool _TM is used. For the milling tool _TM for finishing, it is preferable to use a round tip that conforms to the shape of the thread groove. The milling tools _TM for rough machining and finish machining are stored in the above-mentioned tool magazine (not shown), and are appropriately attached to and detached from the tool spindle 7 by a tool changer (not shown).

After finishing the thread groove using the milling tool _TM , the grinding unit 40 is used to grind the thread groove.

First, the milling tool _TM for finishing is removed from the tool spindle 7 by the above-described tool changer (not shown) and stored in a tool magazine (not shown). The grinding unit 40 is moved from inside the container 61 to the removal position. Specifically, after the opening/closing mechanism 62 is driven to open the lid 63, the advancing/retreating mechanism 67 is driven to move the tool holding portion 67a holding the grinding unit 40 to the removal position (FIGS. 7 and 7). See Figure 10). As shown in FIG. 10, the grinding unit 40 has the thread groove grinding wheel 55 on the upper side, the second held portion 52 is located on the housing body 61 side, and the first held portion 51 is located on the housing body 61 side. is held by the tool holding portion 67a in a posture located on the opposite side.

Next, after rotating the tool spindle 7 so that its axis is horizontal and the tool holding portion faces the storage device 60 side, the tool spindle 7 is moved in the Y-axis direction and the X-axis direction, Positioning is performed so that the axis of the tool spindle 7 and the axis of the first held portion 51 of the grinding unit 40 at the removal position are coaxial. Thereafter, the tool spindle 7 is moved in the Z-axis positive direction to a position where the tool holding portion can hold the first held portion 51 so as to approach the grinding unit 40. The first held portion 51 is held, and the holding of the second held portion 52 by the tool holding portion 67a is released.

Next, by moving the tool spindle 7 away from the container 61, the grinding unit 40 is taken out from the take-out position into the machining area. At that time, the protection tube 56 connected to the grinding unit 40 is pulled out together with the grinding unit 40, but the protection tube 56 is wound around the pulley 65 biased in the opposite direction to the opening, and the pulley 65 is protected. As the tube 56 is pulled out, it moves to the opening side while maintaining the biased state, so that the protection tube 56 is always tensioned and is pulled out in a state in which loosening is prevented (see FIG. 8). Further, even when the tool spindle 7 moves in the Z-axis direction, the pulley 65 is always urged in the opposite direction to the opening side, so that the protective tube 56 is always tensioned and loosened. There is no such thing. Therefore, there is no possibility that the protective tube 56 will become entangled with other structures due to the movement of the tool spindle 7 in the Z-axis direction.

Then, using this grinding tool 55, the thread groove formed in the axial work W is ground. Specifically, as shown in FIGS. 3 and 4, with the shaft-shaped work W clamped by a set of anti-vibration devices 72, the grinding position is between the pair of anti-vibration devices 72, and the thread groove is to be ground. At that time, the tool spindle 7 rotates the thread groove grinding wheel 55 so that the rotation axis of the thread groove grinding wheel 55 is at the same angle as the lead angle of the thread groove with respect to the Z axis in the X-axis-Z-axis plane. In addition to tilting, the thread groove grinding wheel 55 is positioned in the X-axis direction so that the center of rotation of the thread groove grinding wheel 55 is positioned on the Y-Z plane including the axis of the shaft-like workpiece W. At this time, since the rotation axis of the tool spindle 7 is rotated by a slight angle from the vertical direction, the thread groove can be ground without interference between the tool spindle 7 and other structures. can.

Then, in a state in which the thread groove grinding wheel 55 is cut into the thread groove of the shaft-shaped work W by a predetermined cutting amount in the Y-axis direction, the shaft-shaped work W is rotated at a predetermined rotational speed, and the thread is The thread groove of the axial work W is ground by moving the groove grinding wheel 55 in the Z-axis direction at a predetermined feed rate. The rotational speed of the shaft-shaped work W and the feed speed of the thread groove grinding wheel 55 are determined by the pitch of the thread groove, and the feed amount of the thread groove grinding wheel 55 per rotation of the shaft-shaped work W is the pitch of the thread groove. same value. As a result, the lead angle of the formed thread groove becomes a predetermined angle.

Thus, by repeatedly performing the grinding operation while gradually cutting the thread groove grinding wheel 55 into the shaft-like work W in the Y-axis direction, the shape of the thread groove formed in the shaft-like work W can be changed. is finished into a predetermined shape. At that time, by moving the tool post 15 in the same movement direction (Z-axis direction) at the same feed rate in synchronism with the movement of the thread groove grinding grindstone 55 in the Z-axis direction, the anti-vibration unit 70 is used for thread groove grinding. The movement of the grindstone 55 is followed. By doing so, the vicinity of the machining position of the thread grinding grindstone 55 can always be supported by the anti-vibration device 72, similar to the machining using the milling tool _TM described above, and the shaft-shaped work W can be stabilized. It can be supported as it is.

It should be noted that the shape of the outer peripheral surface of the thread groove grinding wheel 55, which is the surface to be ground, is modified by the above-described rotary dresser 30 as required.

When the grinding of the thread groove of the shaft-like workpiece W is completed, the advancing/retreating mechanism 67 is driven to move the tool holding portion 67a to the take-out position, and the tool spindle 7 has a horizontal axis, and the grinding unit is rotated. 40 is positioned on the side of the tool holding portion 67a, the tool spindle 7 is moved in the Y-axis direction and the X-axis direction so that the axis of the tool spindle 7 and the tool holding portion at the removal position are aligned. Position so that the axis of 67a is coaxial.

After that, the second held portion 52 of the grinding unit 40 is moved in the Z-axis positive direction to a position where it engages with the tool holding portion 67a so that the tool spindle 7 approaches the tool holding portion 67a. The second held portion 52 is held by the portion 67a, and the holding of the first held portion 51 by the tool holding portion is released. Next, the tool spindle 7 is moved away from the storage device 60, and the advance/retreat mechanism 67 is driven to move the tool holding portion 67a to the storage position. to At that time, the protective tube 56 is wound around a pulley 65 biased in the opposite direction to the opening, and the pulley 65 maintains the biased state as the tool holding portion 67a retreats. Since it moves to the side, tension is always applied to the protective tube 56, preventing it from becoming loose.

By the above operation, the grinding unit 40 is housed in the housing device 60 . When not in use, the grinding unit 40 is stored in the storage device 60 provided outside the machining area. It is possible to prevent the grinding unit 40 from being soiled, and also to prevent inconvenience such as interference between the grinding unit 40 and a tool or the like used for the other processing.

[Measurement of screw shaft]
When the thread groove is formed in the shaft-like workpiece W and the thread shaft W is formed as described above, the processing accuracy of the thread groove is measured by the thread shaft measuring device 110 described above. That is, first, under the control of the measurement operation control section 117, the measurement unit is transferred to the measurement position by the transfer device as appropriate. Then, under the control of the measurement operation control unit 117, the rotation of the first main spindle 9 and the second main spindle 11 of the multitasking machine 2 is controlled so that the screw shaft W is brought to the angular position set as the initial rotational position. After the determination, the first image is input from the first imaging camera 111 and the second image is input from the second imaging camera 112 via the image input unit 116 . Then, the screw shaft W is reversed by 180° about its axis, and then a third image is input from the first imaging camera 111 .

Based on the input first, second, and third images, the dimension calculator 118 calculates the pitch P and the effective diameter D of the thread groove by the above-described processing. The pitch P and the effective diameter D of the thread groove are output to the output device 5 .

As a result of measurement by the screw axis measuring device 110, if the pitch P and the effective diameter D of the thread groove are not finished to the predetermined dimensions and it is possible to correct them, correction processing using the grinding unit 40 is performed. It can be carried out.

Further, in the multi-tasking apparatus 1 of this example, as described above, the grinding wheel _TG shown in FIGS. 23 and 24 can be used to grind the outer peripheral surface and the end surface of the axial work W. When processing the outer peripheral surface, the sizing device 90 described above can be used to perform grinding while measuring the processing outer diameter with the measuring head 91 .

As described above, according to the multitasking apparatus 1 of the present embodiment, the thread groove of the screw shaft can be machined by a single general-purpose multitasking apparatus 1. Compared to the conventional method of processing using a processing machine, the initial equipment cost can be reduced, and the manufacturing cost of the screw shaft can be reduced.

In addition, since rough cutting, finish cutting, and grinding of the thread groove can be performed by one-time gripping by the first chuck 20 and the second chuck 25, the processing accuracy deteriorates by repeating the gripping a plurality of times. can be prevented.

In addition, rough cutting, finish cutting, and grinding of thread grooves can be performed while the long shaft-shaped work W is clamped by a set of anti-vibration devices 72, thereby realizing stable processing. As a result, the thread groove can be machined with high accuracy.

Since the thread groove is ground using the grinding unit 40, the grinding process can be performed using the general-purpose multitasking machine 2. FIG. The grinding unit 40 is housed in the housing device 60, and the grinding unit 40 is removed from the housing device 60 and used only when performing the grinding process. A series of machining can be performed efficiently without the grinding unit 40 becoming an obstacle. Moreover, since the protection tube 56 connected to the grinding unit 40 is always under tension, the protection tube 56 is prevented from becoming an obstacle to the movement of the grinding unit 40 .

In this example, since the sizing device 90 is provided in the general-purpose multitasking machine 2, the sizing device 90 is used when grinding the outer peripheral surface of the shaft-like workpiece W (or the screw shaft W). Since the grinding process can be performed with a high precision, the grinding process can be performed efficiently.

In addition, in the multitasking machine 1 of this example, the precision of the thread groove of the machined screw shaft W can be measured on-machine by the screw shaft measuring device 110. Therefore, even if the thread groove is not finished to a predetermined dimension, In addition, if the correction is possible, correction processing using the grinding unit 40 can be performed. And by doing in this way, highly accurate screw shaft W can be manufactured efficiently.

Although one embodiment of the present invention has been described above, specific aspects that the present invention can take are not limited to this.

For example, in the screw axis measuring apparatus 110 of the above example, in order to obtain an image with a clear contour of the screw groove, the first lighting device 113 and the second lighting device 114 are placed between the screw shaft W and the first imaging camera. 111 and the second imaging camera 112 are provided on the opposite side, but the present invention is not limited to this. may be provided on the same side as the first imaging camera 111 and the second imaging camera 112 .

Further, the screw axis measuring apparatus 110 of the above example has a configuration in which two first imaging cameras 111 and second imaging cameras 112 and two first lighting devices 113 and second lighting devices 114 are provided. As long as the image capturing camera has a field of view that captures the entire radial direction of the screw shaft W, it is sufficient to have one image capturing camera. In this case, one illumination corresponding to the image capturing camera It would be nice if the device was provided.

In this case, the measurement operation control unit 117 controls the rotation of the first main shaft 9 and the second main shaft 11 of the multi-tasking machine 2 via the multi-tasking machine control unit 4 to rotate the screw shaft W to the initial rotation. After the angular position set as the position is determined, a process of inputting a first image including the entire radial direction of the screw shaft W from the imaging camera via the image input unit 116 is performed.

FIG. 30(a) shows the first image to be input, and FIG. 30(a) shows the outline of the screw shaft W in the first image. In the contour image of the thread groove in the first image, the upper contour image corresponds to an accurate cross section of the thread groove because the optical axis of the imaging camera matches the lead angle of the thread groove on the one side. It is a contour image. On the other hand, the contour image on the lower side is an image in which the contour of the thread groove is distorted because the optical axis of the imaging camera does not match the lead angle of the thread groove on the other side.

Next, the measurement operation control unit 117 rotates the first main shaft 9 and the second main shaft 11 of the multi-tasking machine 2 via the multi-tasking machine control unit 4 to rotate the screw shaft W around its axis. After the 180° inversion, a process of inputting a second image including the entirety of the screw shaft W in the radial direction from the imaging camera via the image input unit 116 is executed.

FIG. 30(b) shows a contour image of the thread groove located on the one side in the second image (contour line of the screw shaft W) captured by the imaging camera. When the screw groove on the other side is rotated by 180° to the area on the one side, the optical axis of the imaging camera and the lead angle of the screw groove on the other side are aligned with each other. The contour image of the thread groove on the other side in the image is a contour image corresponding to an accurate cross section of the thread groove.

After extracting the outline of the thread groove on one side based on the first image captured as described above, the dimension calculation unit 118 calculates the center positions of at least two adjacent thread grooves. , calculating the pitch, which is the interval in the direction along the axis between the center positions of the adjacent thread grooves, and corresponding to the outer circumference of the screw shaft located on the other side opposite to the one side across the axis Then, a process of calculating the distance in the radial direction of the threaded shaft W, which is the distance between the center position of the thread groove on the one side and the outer peripheral contour on the other side, is performed.

In FIG. 30(a), the image captured by the imaging camera is represented by a coordinate system with the Ya-axis and Za-axis as reference axes, and the origin of this Ya-axis-Za axis coordinate system is the imaging optical axis of the imaging camera. match. The Ya-axis coincides with the radial direction of the screw shaft (the Y-axis), and the Za-axis coincides with the longitudinal direction of the screw shaft (the Z-axis). The dimension calculator 118 calculates the center positions (Ya ₁ , Za ₁ ) and (Ya ₂ , Za ₂ ) of each thread groove based on the contour shape of the thread groove extracted from the first image. The interval in the Z-axis direction between the center positions of the screw grooves is calculated as the pitch P (=Za ₂ -Za ₁ ). Further, the dimension calculator 118 extracts an outer peripheral contour corresponding to the outer circumference of the screw shaft W located on the other side, and calculates the distance between the center position of the thread groove on the one side and the outer peripheral contour on the other side. Then, a process of calculating the radial distance (=Ya ₁ +Ya ₃ ) of the screw axis W is performed. However, Ya ₁ = Ya ₂

Next, the dimension calculator 118 extracts the outline of the thread groove on the other side based on the second image captured as described above, and calculates the center position of the thread groove on the other side. At the same time, the outer peripheral contour corresponding to the outer periphery of the screw shaft W on the other side is extracted, and the distance between the center position of the thread groove on the other side and the outer peripheral contour on the other side, which is the diameter of the screw shaft W Perform processing to calculate the distance in the direction.

In FIG. 30(b), the dimension calculator 118 calculates the center position (Ya ₄ , Za ₄ ) of the thread groove on the other side from the extracted contour shape of the thread groove on the other side, and By extracting the outer circumference contour corresponding to the outer circumference of the other side, the distance in the radial direction (that is, the Ya-axis direction) between the center position (Ya ₄ , Za ₄ ) of the thread groove on the other side and the outer circumference contour on the other side Δ(=Ya ₄ −Ya ₅ ) is calculated.

Next, the dimension calculator 118 calculates the radial distance between the obtained center position of the thread groove on the one side and the outer peripheral contour on the other side, and the center position of the thread groove on the other side and the other side. A process of calculating the effective diameter of the thread groove is performed based on the radial distance from the outer peripheral contour of the side.

FIG. 30(c) is an explanatory diagram for explaining this process in an easy-to-understand manner. The contour image on the lower side in FIG. (b)). That is, in FIG. 30(a), the center position of the other thread groove in the lower contour image is located at a position radially shifted by Δ from the outer circumference contour. Therefore, as shown in FIG. Calculated by the formula:
D=Ya ₁ +Ya ₃ +Δ
The dimension calculator 118 calculates the effective diameter D of the thread groove by this calculation formula.

In the above example, the first headstock 8 and the second headstock 10 having the same configuration are provided, but the present invention is not limited to this. It is good also as a tailstock device as a support device to support.

In the above example, the grinding unit 40 is housed in the housing device 60, but the present invention is not limited to this. A laser machining head, an electric discharge machining head, and a tool such as a measurement tool such as a touch probe may be accommodated. Wire members, ie, cables such as wires, pipes for supplying fluids and powders, and protective tubes in which these are inserted are also connected to these tools.

In the above example, the pressing member 75 is provided with the V-shaped groove 75a. Also, the spring bodies 81, 82, 83 for urging the pressing member 75 may be selectively provided or omitted altogether, depending on the clamping force of the piston 79. Further, in the above example, the anti-vibration unit 70 composed of two anti-vibration devices 72 is attached to the turret 16, but the invention is not limited to this, and a single anti-vibration device 72 is attached to the turret 16. You can do it.

In the above example, the thread groove is formed in the shaft-shaped work W by cutting using the milling tool _TM , but the present invention is not limited to this, and the thread groove may be formed by so-called turning. good.

Again, the above description of the embodiment is illustrative in all respects and is not restrictive in any way. Modifications and modifications are possible for those skilled in the art. The scope of the invention is indicated by the claims rather than the above-described embodiments. Furthermore, the scope of the present invention includes modifications from the embodiments within the scope of claims and equivalents.

1 multitasking machine 2 multitasking machine 3 control device 4 multitasking machine control unit 7 tool spindle 8 first headstock 9 first spindle 10 second headstock 11 second spindle 15 tool post 16 turret 20 first chuck 22 gripping jaws 23 Gripping surface 25 Second chuck 27 Gripping claw 28 Gripping surface 30 Rotary dresser 31 Eddy current sensor 32 First point dresser 33 Second point dresser 40 Grinding unit 41 Housing 45 Rotating shaft 49 Rotor 50 Stator 55 Grinding wheel 60 Storage device 61 Storage body 62 Opening and closing mechanism 63 Lid 65 Pulley 66 Slide/biasing part 67 Retraction mechanism 67a Tool holding part 70 Anti-vibration unit 72 Anti-vibration device 73 Base 74 Receiving member 74a V-shaped groove 75 Holding member 75a V-shaped groove 76 Guide Pin 77 Clamp Mechanism 90 Sizing Device 91 Measuring Head 92 Probe 93 Transfer Device 94 Linear Transfer Mechanism 103 Turning Mechanism 104 Rotating Axis 105 Turning Arm 106 Actuator 110 Screw Axis Measuring Device 111 First Imaging Camera 112 Second Imaging Camera 113 First Lighting device 114 Second lighting device 115 Image input unit 116 Measurement operation control unit 117 Dimension calculation unit

Claims (9)

A method for measuring a screw shaft, comprising:
One imaging camera is disposed so as to face the screw shaft, and the optical axis of the imaging camera is located on the outer periphery on one side bordering on the axis of the screw shaft in a plane viewed from the imaging camera side. After arranging the imaging camera so that the lead of the located thread groove and the angle thereof match,
capturing a first image including the entire radial direction of the screw shaft;
Next, after reversing the screw shaft by 180° around the axis, a second image including the entire radial direction of the screw shaft is captured,
Based on the first image, the outline of the thread groove on the one side is extracted, and after calculating the center positions of at least two adjacent thread grooves, the center positions of the adjacent thread grooves along the axis In addition to calculating the pitch, which is the interval in the direction of the one side, extracting the outer peripheral contour corresponding to the outer periphery of the screw shaft located on the other side opposite to the one side across the axis, and extracting the thread groove on the one side Calculate the distance in the radial direction between the center position of and the outer peripheral contour of the other side,
Next, based on the second image, the contour of the thread groove on the other side, which is in line symmetry with the thread groove on the one side about the axis, is extracted, and the center position of the thread groove on the other side is determined. At the same time, extracting the outer peripheral contour corresponding to the outer periphery of the other side of the screw shaft, the distance in the radial direction between the center position of the thread groove on the other side and the outer peripheral contour of the other side is calculated. ,
Next, the obtained radial distance between the center position of the thread groove on the one side and the outer peripheral contour on the other side, and the distance between the center position of the thread groove on the other side and the outer peripheral contour on the other side. A screw shaft measuring method, wherein an effective diameter of a thread groove is calculated based on the radial distance between the two. A method for measuring a screw shaft, comprising:
Two imaging cameras, first and second, are arranged so as to face the screw shaft and have their optical axes parallel to each other. After arranging them side by side at a predetermined interval so that the angle of the lead of the thread groove located on the outer peripheral portion on one side of the axis of the screw shaft is the same,
The first image capturing camera captures a first image including the thread groove on the one side, and the second image capturing camera captures the image on the other side opposite to the one side across the axis. capturing a second image including the located thread groove;
Next, after reversing the screw shaft by 180° around the axis, a third image including the thread groove on the other side rotated to the region on the one side by the first imaging camera and
Based on the first image, the outline of the thread groove on the one side is extracted, and after calculating the center positions of at least two adjacent thread grooves, the center positions of the adjacent thread grooves along the axis The distance in the radial direction of the screw shaft between the first reference position preset in the first image and the center position of the thread groove on the one side is calculated. calculate,
Based on the second image, an outer circumference contour corresponding to the outer circumference of the screw shaft located on the other side is extracted, and a second reference position preset in the second image and the outer circumference of the other side are extracted. calculating the distance in the radial direction between the contour,
Based on the third image, the contour of the thread groove on the other side is extracted, the center position of the thread groove on the other side is calculated, and the outer circumference contour corresponding to the outer circumference of the screw shaft on the other side is calculated. extracting and calculating the distance in the radial direction of the screw shaft between the center position of the thread groove on the other side and the outer peripheral contour on the other side;
Next, the radial distance between the obtained first reference position and the center position of the thread groove on the one side, the diameter between the second reference position and the outer peripheral contour on the other side, and the distance in the direction, the radial distance between the center position of the thread groove on the other side and the outer peripheral contour on the other side, and the distance between the first reference position and the second reference position obtained in advance A screw shaft measuring method, wherein an effective diameter of a thread groove is calculated based on the radial distance of. 3. The screw shaft measuring method according to claim 1 or 2, wherein the imaging portion of the screw shaft imaged by said imaging camera is illuminated by an illumination device. 4. The screw shaft measuring method according to claim 3, wherein the illumination device illuminates the imaged part from a direction opposite to the imaging direction of the imaging camera. A device for measuring a screw shaft,
a support portion that supports the screw shaft so as to be rotatable about its axis;
a rotating device that rotates the screw shaft about the axis;
one imaging camera arranged to face the screw shaft;
a control device for controlling the operation of the rotating device and the imaging camera;
a dimension calculation unit that processes the image captured by the imaging camera and calculates the dimension of the screw shaft,
The imaging camera is arranged so that its optical axis is at the same angle as the lead of the thread groove located on the outer peripheral portion on one side bordering on the axis of the screw shaft in a plane viewed from the imaging camera side. is set up,
The control device controls the rotating device to position the screw shaft at an initial position, and operates the imaging camera to capture a first image including the entire radial direction of the screw shaft. processing;
After that, the rotating device is driven to reverse the screw shaft by 180° about the axis, and the imaging camera is operated to obtain a second image including the entirety of the screw shaft in the radial direction. is configured to perform a process of imaging the
Based on the first image, the dimension calculation unit extracts the contour of the thread groove on the one side, calculates the center positions of at least two adjacent thread grooves, and then calculates the centers of the adjacent thread grooves. Calculating a pitch, which is an interval in the direction along the axis between the positions, and extracting an outer circumference contour corresponding to the outer circumference of the screw shaft located on the other side opposite to the one side across the axis, a process of calculating the distance in the radial direction between the center position of the thread groove on the one side and the outer peripheral contour on the other side;
Next, based on the second image, the contour of the thread groove on the other side, which is in line symmetry with the thread groove on the one side about the axis, is extracted, and the center position of the thread groove on the other side is determined. At the same time, extracting an outer peripheral contour corresponding to the outer periphery of the other side of the screw shaft, calculating the distance in the radial direction between the center position of the thread groove on the other side and the outer peripheral contour of the other side processing;
Next, the obtained radial distance between the center position of the thread groove on the one side and the outer peripheral contour on the other side, and the distance between the center position of the thread groove on the other side and the outer peripheral contour on the other side. and calculating an effective diameter of the thread groove based on the radial distance between the two. A device for measuring a screw shaft,
a support portion that supports the screw shaft so as to be rotatable about its axis;
a rotating device that rotates the screw shaft about the axis;
two imaging cameras, first and second, facing the screw shaft and arranged such that their optical axes are parallel to each other;
a control device for controlling the operation of the rotating device and the imaging camera;
a dimension calculation unit that processes the image captured by the imaging camera and calculates the dimension of the screw shaft,
In the plane viewed from the imaging camera side, both optical axes of the first and second imaging cameras are located on the outer periphery on one side of the axis of the screw shaft. arranged side by side at predetermined intervals so as to match,
The control device controls the rotating device to position the screw shaft at an initial position, and operates the first imaging camera to capture a first image including the thread groove on the one side. A process of capturing an image and operating the second image capturing camera to capture a second image including the thread groove located on the other side opposite to the one side across the axis;
After that, the rotating device is driven to reverse the screw shaft by 180° around the axis, and the first imaging camera is operated to rotate the screw shaft to the one side region. and a process of capturing a third image including the thread groove on the other side,
Based on the first image, the dimension calculation unit extracts the contour of the thread groove on the one side, calculates the center positions of at least two adjacent thread grooves, and then calculates the centers of the adjacent thread grooves. A pitch, which is an interval in the direction along the axis of the positions, is calculated, and the screw axis between a first reference position preset in the first image and the center position of the thread groove on the one side. A process of calculating the distance in the radial direction of
Next, based on the second image, an outer circumference contour corresponding to the outer circumference of the screw shaft located on the other side is extracted, and a second reference position preset in the second image and the other side are extracted. A process of calculating the distance in the radial direction between the outer peripheral contour;
Based on the third image, the contour of the thread groove on the other side is extracted, the center position of the thread groove on the other side is calculated, and the outer circumference contour corresponding to the outer circumference of the screw shaft on the other side is calculated. a process of extracting and calculating the distance in the radial direction between the center position of the thread groove on the other side and the outer peripheral contour on the other side;
Then, the distance between the obtained first reference position and the center position of the thread groove on the one side, the radial distance between the second reference position and the outer peripheral contour on the other side, and the radial distance between the center position of the thread groove on the other side and the outer peripheral contour on the other side, and the radial distance between the first reference position and the second reference position obtained in advance and calculating the effective diameter of the thread groove based on the distance of . 7. The screw shaft measuring apparatus according to claim 5, further comprising an illuminating device for illuminating an imaging portion of the screw shaft imaged by said imaging camera. 8. The screw shaft measuring apparatus according to claim 7, wherein the illumination device is configured to illuminate the imaging part from a direction opposite to the imaging direction of the imaging camera. An NC machine tool comprising the screw axis measuring device according to any one of claims 5 to 8.

Images