JPH0331364B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a touch sensor for position detection that is used by being inserted into the main shaft of a machine tool.

[Conventional technology]

Numerical control of machine tools introduced program-based automation of tool movement, followed by automatic exchange of various tools, but next came the need to guarantee the machining dimensions of workpieces due to wear of tool edges due to long-term machining. To detect wear on the cutting edge, the amount of wear on the cutting edge of the tool used is determined by detecting the finished dimensions of the workpiece. Therefore, it is necessary to measure the dimensions of the machined surface of the workpiece, and for this purpose a touch sensor for position detection is inserted into the main shaft of the machine tool, and the tip of the measuring rod of the sensor is attached to the conductive workpiece. By contacting and energizing, the movement position of the spindle is detected and compared, and the position of the cutting edge of the tool is adjusted or the tool is replaced with a new one.

As a position detecting touch sensor used as described above, there has been one disclosed in Japanese Patent Application Laid-Open No. 58-151540. In this position touch sensor, a measuring rod is passed through a hole formed in the tip plate of the case, the center of the hole is aligned with the center of the measuring rod, and a gap is provided between the peripheral wall of the hole and the measuring rod. A support plate whose plate surface is perpendicular to the length direction of the measurement rod is fixed to the end of the measurement rod located inside the case, and receiving members are fixed at three locations in the circumferential direction of this support plate. are respectively supported via spheres on push screws screwed into the end plate of the case, and a spring is provided between the end plate of the case and the support plate to bias the support plate toward the tip side of the measuring rod. Equipped with a sensor head section,
The handle is fixed on the end plate of the case with the central axis aligned with the measuring rod. Then, there was one in which the handle was attached to the main shaft of a machine tool, the tip of the measuring rod was glued to a workpiece on a table, and the position was detected by a detection circuit.

[Problem that the invention seeks to solve]

However, in the conventional touch sensor for position detection mentioned above, the receiving member provided on the support plate is supported on a push screw screwed into the tip plate of the case through a sphere, so machining of the parts is troublesome. In addition, since the measuring rod was passed through the hole provided in the tip plate of the case with a gap, the measuring rod and support plate vibrated after the detection operation, and their return to the neutral position was slow and stable. There were some problems, such as not being able to do so. Furthermore, in conventional touch sensors, the end plate of the case of the sensor head was simply screwed to the handle that was inserted into the main shaft of the machine tool, so the axial center of the handle and the measuring rod in the neutral state There was a problem in that it was difficult to match.

This invention is an attempt to solve the above-mentioned conventional problems, and the spherical shaft part provided on the measuring rod of the sensor head part is supported on the straight part of the peripheral wall of the hole provided in the case. Although it is easy to process, it can operate stably, and it is also possible to tighten the case and handle of the sensor head part with a tightening bolt with some allowance in the direction intersecting the axial direction of these parts. By supporting the joining ball on the conical surface of the recess provided in the sensor head and the conical surface of the recess provided in the handle, the axes of the handle and measuring rod can be easily adjusted to coincide with each other with a simple structure. The purpose of the present invention is to provide a touch sensor for position detection that enables the following.

[Means for solving problems]

In the position detection touch sensor of the present invention, a cylindrical part having a center axis in the length direction of the measuring rod is provided at the tip of the case, and the measuring rod is passed through a hole in the cylindrical part, and the length of the measuring rod is A spherical shaft part provided at the middle part in the widthwise direction is rotatably supported by the straight part of the peripheral wall of the hole, and the length direction of the measuring rod and the plate surface are perpendicular to the end part of the measuring rod located in the case. Fix the support plate, insert stopper screws parallel to the length direction of the measuring rod into three circumferential locations of the support plate, and place the support plate between the fixation plate fixed in the case and the support plate. A spring biasing the measuring rod tip side is provided, and the tip of the stopper screw located on the measuring rod tip side is separably brought into contact with an abutting part formed on the inner surface of the case perpendicular to the central axis of the cylindrical part. a conical surface of a concave portion provided in the center of the fixing plate of the head portion;
The conical surfaces of the concave portion provided at the center of the tip of the handle are opposed within the case, the joining balls are supported by the two conical surfaces, and are tightened into bolt holes provided at three locations in the circumferential direction of the case. Insert the attachment bolt parallel to the axial direction of the handle with a gap in the direction crossing this axial direction, tighten the case to the handle with the tightening bolt, and align the axial center of the handle with the measuring rod. This allows adjustment to match the center of the tip.

[Effect]

In the touch sensor according to the present invention, since the sensor head portion is configured as described above, by moving the stopper screw screwed into the support plate back and forth in the axial direction, the contact portion formed on the inner surface of the tip portion of the case,
Even if there is a manufacturing error in the support plate or an error in the attachment of the support plate to the measuring rod, the neutral position of the measuring rod relative to the case, especially its tip, can be easily and accurately set, and the processing of the contact part, support plate, etc. Easy to assemble. In addition, the spherical shaft part provided at the middle part in the length direction of the measuring rod is rotatably supported by the peripheral wall in the straight hole of the cylindrical part provided at the tip of the case.
Although it is easy to machine the hole through which the measuring rod passes through, including the straight hole, the measuring rod and support plate may move suddenly during the detection operation, or they may not return to the neutral position due to vibration after detection, or may not return to the neutral position. There is no delay in position detection, and position detection can be performed stably.

Furthermore, the conical surface of the recess provided at the center of the fixing plate fixed in the case of the sensor head section and the conical surface of the recess provided at the center of the tip of the handle are opposed within the case, and joined to the conical surface. Tightening bolts were inserted into the bolt holes provided at three circumferential locations of the ball supporting case with gaps between them, and the case was tightened to the handle with these bolts, so that the case, that is, the sensor head, was attached to the handle. By adjusting the tightening force of the tightening bolts, it is possible to accurately install the ball, even if the machining accuracy of each part of the handle and the machining and assembly accuracy of each part of the sensor head are relatively low. This can be easily done through

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a sensor head section, and the sensor head section 1 is constructed as follows. That is, the measuring rod 4 is attached to the tip of the case 2.
A cylindrical part whose central axis is in the length (axial) direction is provided, and the circumferential wall of the hole 3 of this cylindrical part has a straight part 3a formed in the middle part in the axial direction, and expands toward the opening at both ends. A tapered portion is formed.
The measuring rod 4 is passed through the hole 3 of the case 2, and the measuring rod 4
A spherical shaft portion 5 provided at an intermediate portion in the length direction is rotatably supported by a straight portion 3a of the circumferential wall of the hole 3. A support plate 6 whose longitudinal direction and plate surface are perpendicular to the measuring rod 4 is fitted and fixed concentrically to the end portion of the measuring rod 4 located inside the case 2. Projections 6a are formed at three locations in the circumferential direction, and stopper screws 7 are screwed into the projections 6a at equal intervals in the circumferential direction in parallel to the length direction of the measuring rod 4. A fixing plate 8 is fitted into the axially intermediate portion of the case 2, and the fixing plate 8 is clamped to the snap spring 9 fitted to the case 2 and the step 2a of the case 2.
Fixed to case 2. Fixed plate 8 and support plate 6
A coil spring 10 is interposed between the coil spring 10 and the support plate 6 , which urges the support plate 6 toward the axial tip side of the measuring rod 4 . is supported by an abutment surface 2b projected from the inner surface of the tip end of the case 2. The contact surface 2b is formed perpendicular to the axial direction of the hole 3, that is, the length direction of the measuring rod 4, and as shown in FIG.
1 of the protrusion 6a with a pair of pins 11, 11 provided in the
The support plate 6 is restrained from rotating around the four axes of the measuring rod. In addition, case 2 of measuring stick 4
A measuring ball 4a is provided at the tip protruding from.

A centering member 12 is provided at the center of the fixing plate 8.
is fitted, and a concave portion having a conical surface 12a is formed in a portion of the member 12 that protrudes from the fixing plate 8 toward the distal end of the case 2, and the fixing plate 8 of the centering member 12
There is a spring receiver 12b on the end side protruding from the case 2.
is projected, and the coil spring 10 is fitted and supported by the spring receiver 12b. A handle 13 is arranged on the distal end side of the case 2 with a space therebetween, and a centering member 1 made of fluororesin is provided at the center of the tip of the handle 13.
4 is fitted, and the centering member 14 is formed with a recess having a conical surface 14a opposite to the conical surface 12, and a joining ball 15 made of a steel ball is interposed between both the conical surfaces 12a and 14a. At the end of the case 2, bolt insertion holes 16 are formed at three locations in the circumferential direction at equal intervals and parallel to the axial direction, and screw holes 17 facing the bolt insertion holes 16 are formed on the flange 13a of the handle 13.
is formed. A tightening bolt 18 is inserted into the bolt insertion hole 16 parallel to the axial direction of the handle 13 with a gap in the radial direction from the hole wall, and the head 18a of the tightening bolt 18 and the bolt of the case 2 are inserted. hole 16
A washer 19 made of fluororesin is provided between the peripheral parts, a tightening bolt 18 is tightened in the screw hole 17, and the joint ball 15 is supported on the conical surfaces 11a and 14a. Note that a sealing material 20 is provided between the end of the inner peripheral surface of the case 2 and the leading end of the outer peripheral surface of the handle 13.
A fitting part 13b for fitting into the main shaft of a machine tool (not shown) is provided at the distal end of the handle part 13.

In the position detection touch sensor of the embodiment configured as described above, the insertion part 13b of the handle 13 is inserted into the main shaft of a machine tool, and by moving the main shaft, the position detection touch sensor provided at the tip of the measuring rod 4 can be moved. By bringing the ball 4a into contact with the processed surface of the workpiece, the measuring rod 4 is displaced toward the distal side in the axial direction (Z direction) against the coil spring 10, and the circumferential wall of the hole 3 of the spherical shaft portion 5 is By swinging the measuring rod 4 in the axial direction (X, Y direction) using the supporting part to the straight part 3a as a fulcrum,
The stopper screws 7 of the support plate 6 fixed to the measuring rod 4 separate from the contact surface 2b of the case 2, thereby electrically operating the detector connected to the stopper screws 7, causing each screw 7 to come into contact. The movement position of the spindle is detected depending on whether or not it is in contact with the surface 2b, and the amount of wear on the cutting edge of the tool is determined.

In the present invention, the part of the handle that is inserted into the machine tool is not limited to a straight shape, but may be tapered. Further, the present invention can also be used for detecting the position of articles other than those described above.

〔Effect of the invention〕

As explained above, in the position detection touch sensor of the present invention, a cylindrical part having a center axis in the longitudinal direction of the measuring rod is provided at the tip of the case, and the measuring rod is passed through the hole in the cylindrical part. A spherical shaft provided at the middle part of the measuring rod in the longitudinal direction is rotatably supported by the straight part of the peripheral wall of the hole, and a spherical shaft part provided at the middle part in the longitudinal direction of the measuring rod is rotatably supported by the straight part of the circumferential wall of the hole. A support plate whose plate surface is orthogonal to the above is fixed, and stopper screws are inserted in three circumferential locations of this support plate parallel to the length direction of the measuring rod, and the fixation plate fixed in the case and the support plate are connected to each other. A spring is provided between them to urge the support plate toward the tip of the measuring rod, and the end of the stopper screw located on the tip side of the measuring rod is a contact formed on the inner surface of the case so as to be perpendicular to the central axis of the cylindrical portion. A sensor head part is provided, the sensor head part being in contact with the fixing plate in a separable manner and detecting whether or not each screw is in contact with the abutment surface, and the sensor head part has a conical recess provided in the center of the fixing plate of the head part. and the conical surface of the recess provided at the center of the tip of the handle in the case, and
A joint ball is supported on two conical surfaces, and tightening bolts are inserted into bolt holes provided at three circumferential locations of the case in a direction parallel to the axial direction of the handle and spaced apart from each other in a direction intersecting this axial direction. By inserting the case into the handle and tightening the case onto the handle using the tightening bolt, it is possible to adjust the shaft center of the handle to match the center of the tip of the measuring rod.
The following effects can be obtained.

That is, the touch sensor according to the present invention is
Since the sensor head was configured as described above,
By moving the stopper screw screwed into the support plate back and forth in the axial direction, the abutment part formed on the inner surface of the tip of the case, even if there are manufacturing errors in the support plate or errors in mounting the support plate to the measuring rod, the case can be easily fixed. The neutral position of the measuring rod, especially its tip, can be set easily and accurately, and the abutment part, support plate, etc. can be easily processed and assembled. In addition, since the spherical shaft provided at the intermediate portion in the length direction of the measuring rod is rotatably supported on the circumferential wall of the straight hole in the cylindrical portion provided at the tip of the case, the measuring rod including the straight hole is supported. However, the measuring rod and support plate may move suddenly during the detection operation, or they may vibrate and not return to the neutral position after detection.
There is no delay in returning, and stable position detection can be performed.

Furthermore, the conical surface of the recess provided in the center of the fixing plate fixed in the case of the sensor head section and the conical surface of the recess provided in the center of the tip of the handle are opposed within the case, and both of the conical surfaces Tightening bolts were inserted into bolt holes provided at three circumferential locations of the support case with gaps between the joint balls, and the case was tightened to the handle with these bolts, so that the case, that is, the sensor head, was attached to the handle. By adjusting the tightening force of the tightening bolts, it is possible to accurately install the ball, even if the machining accuracy of each part of the handle and the machining and assembly accuracy of each part of the sensor head are relatively low. This can be easily done through Therefore, high accuracy is not required in processing and assembling each part, and while the device can be manufactured easily and inexpensively, highly accurate and stable position detection can be performed.

[Brief explanation of drawings]

FIG. 1 is a longitudinally sectional front view of a main part showing an embodiment of the present invention, and FIG. 2 is a plan view showing a support plate portion. 1...Sensor head part, 2...Case, 2a
... Contact surface, 3 ... Hole, 3a ... Straight part of peripheral wall, 4 ... Measuring rod, 5 ... Spherical shaft part, 6 ... Support plate, 7 ... Stopper screw, 8 ... Fixing plate, 1
0... Coil spring, 12, 14... Centering member, 12a, 14a... Conical surface of recess, 13...
...Handle, 15...Joining ball, 16...Bolt insertion hole, 17...Screw hole, 18...Tightening bolt.

Claims (1)

[Claims] 1. A cylindrical part with the central axis in the length direction of the measuring rod is provided at the tip of the case, the measuring rod is passed through a hole in this cylindrical part, and a spherical shaft is provided at the middle part in the length direction of the measuring rod. A support plate whose plate surface is perpendicular to the length direction of the measuring rod is fixed to the end portion of the measuring rod located in the case, and this supporting plate Stopper screws are screwed into three locations in the circumferential direction of the measuring rod parallel to the length direction of the measuring rod, and a spring is placed between the fixed plate fixed in the case and the supporting plate to bias the supporting plate toward the tip of the measuring rod. are provided, and the tips of the stopper screws located on the tip end side of the measuring rod are brought into contact with a contact portion formed on the inner surface of the case perpendicular to the central axis of the cylindrical portion, so that each screw is connected to the contact portion. It is equipped with a sensor head section that detects whether or not it is in contact with the contact surface, and the sensor head section has a conical surface of a recess provided at the center of the fixed plate of the head section and a recess provided at the center of the tip of the handle. and a conical surface are opposed to each other in the case, and a joint ball is supported on the two conical surfaces.
Insert a tightening bolt into the bolt hole provided at each location, parallel to the axial direction of the handle, and with a gap in the direction crossing this axial direction, tighten the case to the handle with the tightening bolt, and then tighten the case to the handle. A touch sensor for position detection, characterized in that the axis center of the measuring rod can be adjusted to match the center of the tip of the measuring rod.