JPH0435004B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a measuring device that measures the dimensions, shape, etc. of an object to be measured, and the present invention relates to a measuring device that measures the size, shape, etc. of an object to be measured. It can be used to correct positional errors at the tip of the measurement probe.

[Background technology and its problems] Conventional measuring devices have an X-axis unit attached to the bed.
A column is provided on the X-axis unit so as to be movable in the axial direction, a column is provided on the X-axis unit so as to be movable in the Z-axis direction, and a spindle head is provided on this column so as to be movable in the Y-axis direction, and a measurement probe is attached to the tip of the spindle head. It has a structure in which the main shaft is rotatably housed.

However, when trying to support the measurement spindle horizontally, the measurement probe is attached to the tip of the measurement spindle, so the proximal end of the measurement spindle is supported by the spindle head, so the tip of the measurement probe inevitably becomes It will slope downward.

Therefore, when detecting the moving position of the measurement probe in the Y-axis direction, accurate position data can be obtained by detecting the position of the tip of the measurement probe, but in reality, the position of the tip of the measurement probe is detected. That is impossible.

Therefore, at present, the part of the spindle head near the measurement probe is measured, but the reality is that errors occur depending on the distance from the measurement position to the tip of the measurement probe.

[Object of the Invention] It is an object of the present invention to solve the above-mentioned conventional drawbacks, and to solve the above-mentioned problem of the above-mentioned conventional problems. An object of the present invention is to provide a measuring device with a tilt correction function that corrects positional errors in directions.

[Means and effects for solving the problem] Therefore, in the present invention, the amount of vertical movement of different parts in the direction of the main axis of the member that moves the main measurement axis toward sensitization is determined. The position of the tip of the measurement probe is determined from the difference in the amount of movement.

Specifically, the measurement spindle, which is supported horizontally and has a measurement probe attached to its tip, is automatically moved in three-dimensional directions according to a preset procedure.
In a measuring device that measures the dimensions, shape, etc. of an object to be measured based on the amount of movement of the measurement spindle when a measurement probe is involved in the measurement object, the upper and lower parts of the member that moves the measurement spindle in the vertical direction differ in the main axis direction. The present invention is characterized in that a pair of length measuring means for detecting the amount of movement in each direction is provided, and means is provided for determining the vertical position of the tip of the measurement probe from the length measurement values detected by the pair of length measuring means.

[Embodiment] FIG. 1 shows an embodiment of the measuring device of the present invention. In the same figure, at the rear of the top surface of bed 1,
A saddle 3 is provided along the guide groove 2 so as to be movable in the left-right direction (X-axis direction) of the bed 1 by driving a drive device 4. The drive device 4 includes a feed screw shaft 5 rotatably supported on the upper surface of the bed 1 along the X-axis direction and screwed into the saddle 3;
It is composed of a motor 6 that rotates this feed screw shaft 5.

Further, a column 13 is provided on the upper surface of the saddle 3 along the guide groove 12 so as to be movable in the front-rear direction (Z-axis direction) of the bed 1 by driving a drive device 14. The drive device 14 drives the saddle 3
a feed screw shaft 15 rotatably supported along the Z-axis direction on the upper surface and screwed into the column 13;
It is composed of a motor 16 that rotates this feed screw shaft 15.

Further, a spindle head 21 is provided on the column 13 so as to be movable in the vertical direction (Y-axis direction) of the bed 1 by driving a drive device 24 via a guide (not shown). The drive device 24 includes a feed screw shaft 25 rotatably supported by the column 13 along the Y-axis direction and screwed into the spindle head 21;
It is composed of a motor 26 that rotates this feed screw shaft 25. Furthermore, in the spindle head 21,
Multiple types of measurement probes 22 ₁ to 22 ₄ , 22 at the tip
A measuring main shaft 23 to which _{the o} is selectively mounted is rotatably supported.

On the other hand, at the front of the upper surface of the bed 1, there is provided an automatic measurement probe exchanger 31 that stores a plurality of types of measurement probes 22 ₁ to 22 ₄ , 22 _o in advance and selectively attaches them to the measurement spindle 23, and a calibration stand. 32 are provided respectively. The measurement probe automatic exchange device 31 replaces multiple types of measurement probes 22.
It has a plurality of probe stockers 33 ₁ to 33 ₅ that hold probes ₁ to 22 ₄ and 22 _o in advance, and these can be selectively raised and lowered in the vertical direction. When replacing the probes, the measurement probes 22 ₁ to 22 ₄ , 2
For example, when the measurement probe 22 ₁ among the 2 _o is designated in the next measurement process, the probe stocker 33 ₁ of the measurement probe 22 ₁ and the empty probe stocker 33 ₅ are raised. In this state, after the measurement probe 22 _o attached to the measurement spindle 23 is held in the empty probe stocker 33 ₅ , the measurement probe 22 o of the probe stocker 33 ₁ is moved in the three-dimensional direction of the measurement spindle 23 . ₁ is measurement spindle 2
It is attached to 3. Thereafter, the raised probe stockers 33 ₁ and 33 ₅ are lowered to their original positions, completing a series of probe exchanges.

FIG. 2 shows a length measuring system for detecting the amount of movement of the saddle 3, column 13, and spindle head 21 in each axial direction. In the figure, a laser beam from a laser oscillator L provided in the bed 1 is split into two directions in the X-axis direction and the Z-axis direction by a splitter _S1 . The laser beam separated in the Z-axis direction was refracted in the X-axis direction by an interferometer I ₁ fixed on the bed 1, and then reflected by a mirror M ₁ fixed on the front side of the saddle 3. After that, the light passes through the interferometer _I1 and is received by the receiver _R1 . Here, the interferometer I ₁ , mirror M ₁ and receiver R ₁ described above constitute a length measuring means 41 in the X-axis direction.

Further, in the splitter S ₁ , the laser beam split in the X-axis direction is sequentially refracted by benders B ₁ , B ₂ , and B ₃ fixed to the saddle 3, and then fixed to the lower side of the column 13. Vendor B ₄
After being refracted in the Y-axis direction, the light beam is split into the Y-axis direction and the Z-axis direction by a splitter _S2 fixed to the lower side of the column 13. The laser beam separated in the Z-axis direction passes through an interferometer I ₂ and is reflected by a mirror M ₂ fixed to the front edge of the upper surface of the saddle 3, and then passes through an interferometer I ₂ and is received by a receiver R ₂ . be done.
Here, the interferometer I ₂ , the mirror M ₂ and the receiver R ₂ constitute a length measuring means 42 in the Z-axis direction.

Further, in the splitter S ₂ , the laser beam split in the Y-axis direction is refracted in the Z-axis direction by a bender B ₅ fixed to the upper side of the column 13, and then split in the Z-axis direction and in the Z-axis direction by the splitter S ₃ . The light is dispersed in the X-axis direction. The laser beam separated in the X-axis direction is passed through an interferometer fixed to the top surface of the column 13.
The light is refracted by I ₃ in the Y-axis direction, then reflected by a mirror M ₃ fixed to the spindle head 21, passes through an interferometer I ₃ , and is received by a receiver R ₃ . put it here,
The interferometer I ₃ , mirror M ₃ and receiver R ₃ constitute a first length measuring means 43 in the Y-axis direction.

On the other hand, in the splitter _S3 , the laser beam split in the Z-axis direction is refracted in the X-axis direction by a bender _B6 fixed to the upper side of the column 13.
Next, an interferometer fixed to the top surface of the column 13
After being refracted in the Y-axis direction by I ₄ and further reflected by a mirror M ₄ fixed to the spindle head 21, the light passes through an interferometer I ₄ and is received by a receiver R ₄ . put it here,
The interferometer I ₄ , mirror M ₄ and receiver R ₄ constitute a second length measuring means 44 in the Y-axis direction.

The length measurement value detected by the length measurement means 41 in the X-axis direction, that is, the amount of movement of the saddle 3 in the X-axis direction, and the length measurement value detected by the length measurement means 42 in the Z-axis direction, that is, the Z-axis direction of the column 13. As shown in FIG. device 61.

The NC device 61 includes the length measuring means 41 in the X-axis direction.
The length measurement value given from the X-axis direction is compared with the command value in the X-axis direction, and the military drive device 4 is driven by the difference via the control device 62. Further, the length measurement value given from the length measuring means 42 in the Z-axis direction is compared with the command value in the Z-axis direction, and the drive device 14 is driven by the difference thereof via the control device 63. Furthermore, the amount of movement in the Y-axis direction is determined from the length measurement values given from the first and second length measuring means 43 and 44 in the Y-axis direction and the data stored in advance in the storage device 65, and this amount of movement is calculated. The drive device 24 is driven via the control device 64 by the difference between the command value and the command value in the Y-axis direction. In addition, when a data acquisition command signal is given from each measurement probe, the length measurement values in each axis direction are stored in the storage device 65 as measurement values of the object to be measured.

As shown in FIG. 4, the storage device 65 stores measurement data as well as the second data in the Y-axis direction.
Each measurement probe 22 ₁ to 22 ₄ , 22
The distances L ₁ to L _o to the tip of _{the o} are stored, and the first and second length measuring means 43, 4 in the Y-axis direction are stored.
The interval 1 at which the spindle head 21 is irradiated with the 4 laser beams is stored.

Next, the operation of this embodiment will be explained. In measurement,
A plurality of measurement probes 22 ₁ to 22 ₄ , 22 _o held in each probe stocker 33 ₁ to 33 ₅ of the measurement probe automatic exchange device 31 selectively move the measurement main shaft 23
The shape and dimensions of the workpiece are automatically measured by moving the measuring spindle 23 in three-dimensional directions.

At this time, among the movements in the three-dimensional direction of the detection ends of the measurement probes 22 ₁ to 22 ₄ , 22 _o attached to the measurement spindle 23, the amount of movement of the detection ends of the measurement probes in the X-axis direction, that is, the saddle 3 The amount of movement in the X-axis direction is detected by the length measuring means 41 in the X-axis direction.
In addition, the amount of movement of the detection end of the measurement probe in the Z-axis direction, that is, the amount of movement of the column 13 in the Z-axis direction, is
It is detected by the length measuring means 42 in the axial direction. Furthermore, the amount of movement of the detection end of the measurement probe in the Y-axis direction, that is, the amount of movement of the spindle head 21 in the Y-axis direction, is determined as follows.

Now, as shown in FIG. 5, the first length measuring means 43
The length measurement value of y ₁ is the length measurement value of the second length measurement means 44.
If y ₂ is the measured length value of the tip of the measurement probe as y ₀ , then the following relationship holds: y ₁ - _{y 2} /y ₂ -y ₀ = 1/L, so the position of the tip of the measurement probe can be determined from this. .

In short, the difference between the length measurement values obtained by the first and second length measurement means 43 and 44, and the difference between the length measurement values obtained by the first and second length measurement means 43 and 44
The vertical position of the probe tip can be determined from the distance 1 in the measurement main axis 23 direction between the two and the distance L from the second length measuring means 44 to the measurement probe tip.

Therefore, according to the present embodiment, it is possible to correct the vertical positional error of the measuring probe tip caused by the vertical tilting of the horizontally supported measurement main shaft 23, so that highly accurate measurement can be achieved.

Furthermore, since it is sufficient to provide a pair of length measuring means 43 and 44 for detecting the amount of vertical movement of different positions in the axial direction of the main measuring shaft 23, it has the advantage of being relatively simple in terms of configuration. be.

In addition, in implementation, the length measuring means in the X, Z, and Y axis directions is not limited to the laser length measuring device described in the above embodiment, but may be, for example, an inductosyn or the like.

[Effects of the Invention] As described above, the present invention provides a measuring device that can achieve highly accurate measurement by correcting the vertical error of the probe tip caused by the vertical tilt of the horizontally supported measurement main shaft. can do.

[Brief explanation of drawings]

The drawings show an embodiment of the measuring device of the present invention. Fig. 1 is a perspective view showing the overall appearance, Fig. 2 is a perspective view showing the length measuring means, and Fig. 3 is a block diagram showing the circuit configuration. , FIG. 4 is an explanatory diagram showing the relationship between the laser beam of the length measuring means in the Y-axis direction and the spindle head, and FIG. 5 is a diagram showing the principle of correction based on the inclination of the measurement spindle. 21... Spindle head, 22 ₁ to 22 ₄ , 22 _o , 23
... Measurement main axis, 43, 44 ... First and second length measuring means, 61 ... NC device.

Claims (1)

[Claims] 1. A measuring spindle that is supported horizontally and has a measuring probe attached to its tip is automatically moved in a three-dimensional direction according to a preset procedure, while the measuring probe touches the object to be measured. In a measuring device that measures the dimensions, shape, etc. of an object to be measured from the amount of movement of a measurement spindle when A measuring device with a tilt correction function, characterized in that a pair of length measuring means is provided, and means for determining the vertical position of the tip of the measuring probe from the length measurement values detected by the pair of length measuring means.