JP2000292151A - Automatic sizing head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the automatic sizing head small-sized and to facilitate the sizing measurement of a work in a narrow place. SOLUTION: The automatic sizing head H is equipped with a couple of measuring jaws 20 which are provided to a case main body 23 so that they freely swing, an air cylinder 40 which opens and closes the measuring jaws 20, and a detector 30 which outputs a measured value according to the position shifts of the measuring jaws 20 when the work 21 is measured by the measuring jaws 20; and levers 25 which extend into the case main body 23 are coupled with the rear-end parts of the measuring jaws 20, arm parts 34 which project to the opposite levers 25 are provided behind the fulcrum axes 24 of the levers 25, and contact parts 35 of the air cylinder 40 which are arranged in the case main body 23 and swing the measuring jaws 20 in the opposite direction from the measuring direction of the work 21 through the operation of the air cylinder 40 are formed at the tip parts of the arm parts 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic sizing head which is directly mounted on a machine tool such as a cylindrical grinder or an automatic lathe and measures the outer diameter and inner diameter of a workpiece during grinding or cutting.

[0002]

2. Description of the Related Art Conventionally, as an automatic sizing head of this type, for example, an inner diameter measuring and sizing apparatus shown in FIG. 6 is known. This includes a measuring jaw 2 provided on the case body 1 so as to be swingable in a measuring direction and a retracting direction, a spring 3 urged in a measuring direction via a lever 13 connected to the measuring jaw 2, and the case A pair of left and right air cylinders 5 provided outside the main body 1 and operated by supply and stop of compressed air from the air compressor 4. Compressed air from the air compressor 4 is supplied to one chamber of each air cylinder 5. When the rod is supplied, the rods 6 extend and push the base end of the L-shaped measuring jaw 2 so that the measuring jaw 2 is retracted around the fulcrum shaft 7 in the retractor direction.
That is, it swings in a direction that does not collide with the work 8. Then, after the measuring jaw 2 in the retracted state is inserted into the inner diameter portion 9 of the work 8, the solenoid valve 10 is switched to supply compressed air to the other chamber of the air cylinder 5.
Is contracted, the measuring jaw 2 swings about the fulcrum shaft 7 in the measuring direction by the urging force of the spring 3, and the contact 11 fixed to the distal end of the measuring jaw 2 becomes the inner diameter portion 9.
Contact At this time, the inner diameter of the work 8 can be measured based on an output signal from the operation transformer 12 generated based on a change in the position of the measuring jaw 2.

[0003]

However, in the above-mentioned conventional automatic sizing head, the air cylinder 5 for swinging the measuring jaw 2 is provided outside the case body 1, so that the air cylinder 5 is accordingly provided. The whole equipment becomes large,
Further, since the rod 6 is driven outside the case body 1, it is difficult to measure the size of the work 8 in a narrow place.

Accordingly, the present invention provides a drive unit for swinging the measuring jaw in the case body to reduce the size of the fixed-size head, and expands and contracts the rod of the drive unit in the case body. This makes it easy to measure the size of the work in a narrow place.

[0005]

According to a first aspect of the present invention, there is provided an automatic sizing head comprising: a pair of measuring jaws provided on a case body so as to be swingable; And a detector that outputs a measured value based on a change in the position of the measuring jaw when the work is measured by the measuring jaw, wherein a rear end of the pair of measuring jaws is provided. A lever extending into the case body is connected to each of the arm portions, and arm portions projecting toward the other levers are provided behind the swing fulcrum of the lever, and a case body is provided at a tip end of the arm portion. A contact portion with the driving device is formed, which is configured to swing the measuring jaw in a direction opposite to the measuring direction of the workpiece by the operation of the driving device disposed therein.

In the automatic sizing head according to a second aspect of the present invention, the driving device may be configured such that when the driving device is operated, a contact portion provided at a tip portion of the arm portion is extended by a tip end of an elongated rod. It is an air cylinder that can be pushed and spread.

In the automatic sizing head according to a third aspect of the present invention, the contact portion provided at the distal end of the arm portion crosses the distal end portion of each arm portion, and then the projecting direction of the arm portion. And formed opposite to each other.

The automatic sizing head according to a fourth aspect of the present invention is characterized in that a control board for adjusting a signal output from a detector is provided in a space behind the lever in the case main body.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an automatic sizing head according to the present invention will be described below with reference to the accompanying drawings. 1 to 4 show an embodiment of an automatic sizing head for measuring the outer diameter dimension of a work. FIG. 1 is a horizontal sectional view of the entire apparatus, and FIG. 2 is a vertical sectional view of the entire apparatus. FIG. FIG. 3 is a sectional view taken along line AA of FIG.
FIG. 4 is a sectional view of the fulcrum shaft in which a portion B in FIG. 2 is enlarged.

In FIG. 1 to FIG. 4, the automatic sizing head H has a pair of measuring jaws 20 arranged in parallel. Is attached. The rear end of the measuring jaw 20 is
The lever 25 is swingably supported by a fulcrum shaft 24 provided in the shaft 3 and is integrally connected to a distal end portion of the lever 25 by a screw 26. Therefore, the measuring jaw 20 is connected to the case body 2
3 can swing freely in the left-right direction.

The rear end of each of the levers 25 is connected to the central wall 28 of the case body 23 by a compression coil spring 27, and normally swings in a direction in which the measuring jaw 20 is closed by the spring force of the compression coil spring 27, that is, in the measurement direction. It is biased to move. In FIG. 1, reference numeral 29 denotes a stopper when the lever 25 is swung by the compression coil spring 27.
By contacting the inner wall surface of No. 3, the tips of the tracing stylus 22 are prevented from hitting each other.

In the vicinity of the compression coil spring 27, a detector 30 for outputting a measurement signal based on a change in the position of the lever 25 when the tracing stylus 22 comes into contact with the outer peripheral surface of the work 21 is disposed on the lever 25. ing. The detector 30 has a differential transformer type detection structure, and is provided on an inner periphery of a core 31 extending from one lever 25 and a cylindrical body extending from the other lever 25 so as to surround the core 31. And a coil 32.

Further, an opening / closing portion 33 for swinging the measuring jaw 20 is provided at the center of the lever 25. As shown in detail in FIG. 3, the opening / closing section 33 includes an arm section 34 extending toward the other lever 25 and a contact section 35 formed at the tip of the arm section 34. The arm portion 34 includes horizontal arms 36 extending horizontally from the upper surface and the lower surface of the lever 25, respectively.
And a vertical arm 37 extending in the vertical direction after the end portions cross each other, and a pair of contact portions 35 are provided on the vertical arm 37 so as to face each other. A gap is formed between the two contact portions 35, and a distal end portion of a rod 41 of the air cylinder 40 described later is pushed into the gap so as to be able to advance and retreat. When the tip of the elongated rod 41 enters the gap and pushes out the contact portion 35, the compression coil spring 27 is compressed and contracted because the left and right arm portions 34 further cross, and the lever 25 swings in the opening direction of the measuring jaw 20. Will do.

On the other hand, as shown in FIGS. 1 and 2, only one air cylinder 40 is disposed in the case body 23. The air cylinder 40 is provided with the lever 2
5 and in the middle of the left and right levers 25, and as described above, the rod 4
One tip conical portion 41a is located so as to face the gap of the contact portion 35. A pipe 4 communicating from a rear end of the air cylinder 40 to a compressor device or the like (not shown) is provided.
2 is extended.

In this embodiment, a circuit for processing a measurement signal output from the detector 30 is provided in a space 43 in the case body 23 formed by the upper part of the air cylinder 40 and the rear part of the lever 25. Is mounted on the control board 44. The control board 44 is fixed to the case main body 23 and the detector 3
0 and external devices (not shown) by wires 45 and 46, respectively. The wiring 46 is connected to the case body 2
3 is disposed in a tube 47 fixed to the rear end of the tube 3 so that a load is not applied to the wiring 46. The control board 44 outputs an electric signal output based on the measured value from the detector 30 to an external amplifier or the like after zero point adjustment and gain adjustment. This is because the output and the zero point of the electric signal obtained from the detector 30 vary among the automatic sizing heads, and it is necessary to adjust them by the control board 44 to maintain compatibility. Conventionally, the control board 44 is provided outside the case body 23 and is connected by a cord. Therefore, there is a problem that not only is it troublesome to install the automatic sizing head H or to adjust the zero point or the like, but also if the cord is pulled, the measurement accuracy is affected. In the above embodiment, one air cylinder 40
The effective space 43 in the case body 23 by disposing
Was formed, and the control board 44 was disposed using the space 43, so that the above problem could be solved.

As shown in FIG. 4, the fulcrum shaft 24 in this embodiment has a structure in which pins 50 provided on the lever 25 are supported by radial ball bearings 51 and 52 at the top and bottom, respectively. Twenty-five horizontal swings are possible. Outer ring 51 of radial ball bearings 51 and 52
A and 52a are fixed to a bearing holder 53 fixed to the case main body 23. In particular, the outer ring 51a of the upper radial ball bearing 51 slightly protrudes from the bearing holder 53. Then, one perforated plate 54 is bridged over the radial ball bearings 51 of both levers 25 so as to press the outer ring 51 a downward, and is fixed to the upper surface of the bearing holder 53. By applying a preload to the radial ball bearing 51 in this manner, it is possible to eliminate the backlash on the fulcrum shaft 24 when the lever 25 is swung, and as a result, the repetition stability of the measurement accuracy increases. Become.

Next, the operation of the automatic sizing head H configured as described above will be described. As shown in FIG.
When compressed air is sent from the air compressor into one chamber of the air cylinder 40, the rod 41 extends, and the contact pin portion 35 of the opening / closing portion 33 is pushed right and left by the tip conical portion 41a. As a result, the lever 25 swings around the fulcrum shaft 24 in a direction to open the measuring jaw 20 against the urging force of the compression coil spring 27. The automatic sizing head H is brought close to the work 21, and the tracing stylus 22 is positioned on both sides of the work 21. Next, when the compressed air is supplied from the air compressor to the other chamber of the air cylinder 40 again by switching the solenoid valve, the rod 41 contracts and comes out of the contact portion 35, and then the measuring jaw 20 is pressed by the urging force of the compression coil spring 27. Swings in the closing direction,
The tip of the tracing stylus 22 contacts the outer peripheral surface of the work 21. The amount of change in the position of the lever 25 at this time is detected by the detector 30, converted into an electric signal, and output as an outer diameter measurement value.

The automatic sizing head H is generally mounted on a slide unit or the like of a machine tool, and stands by at a position away from the work 21 while the work 21 is being processed. Then, once the processing of the work 21 is completed, the slide unit moves and the automatic sizing head H
Is brought closer to the work 21 and the measuring jaw 20 is swung in the opening direction, and the work 21 is inserted between the pair of tracing styluses 22. Then, as described above, the tracing stylus 22 is closed and brought into contact with the outer peripheral surface of the work 21 to measure the outer diameter dimension. At this time, if the outer diameter dimension of the work 21 does not reach the predetermined dimension, the automatic sizing head H returns to the standby position, and then the processing of the work 21 is started again. Finish with the outer diameter of

The automatic sizing head H according to the above-described embodiment is for measuring the outer diameter of the work, but it is of course applicable to measuring the inner diameter of the work in the same manner.

[0020]

As described above, according to the automatic sizing head according to the present invention, since the driving device for swinging the measuring jaw is disposed in the case body, the size of the automatic sizing head can be reduced. In addition, the sizing of the work in a narrow place is facilitated by expanding and contracting the rod of the driving device in the case body.

Further, according to the automatic sizing head according to the present invention, since the driving device for swinging the measuring jaw is constituted by the air cylinder, the operation mechanism is extremely simple.

Further, according to the automatic sizing head according to the present invention, the contact portion has the above-described structure in order to swing the measuring jaw by the operation of the air cylinder. Swing can be performed reliably.

Further, according to the automatic sizing head according to the present invention, since the control board for adjusting the signal output from the detector is provided in the space behind the lever in the case body, zero point adjustment and gain adjustment can be performed. This has the effect of being easy and improving the measurement accuracy.

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view of an automatic sizing head according to the present invention.

FIG. 2 is a longitudinal sectional view of the automatic sizing head according to the present invention.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a sectional view of a fulcrum shaft in which a portion B in FIG. 2 is enlarged.

FIG. 5 is a sectional view showing the movement of a measuring jaw when a rod of an air cylinder is extended.

FIG. 6 is a sectional view showing an example of a conventional inner diameter measuring and sizing apparatus.

[Explanation of symbols]

 H Automatic sizing head 20 Measurement jaw 21 Work 22 Measuring element 23 Case main body 24 Support shaft 25 Lever 30 Detector 34 Arm unit 35 Contact unit 40 Air cylinder (drive unit) 43 Space unit 44 Control board

Claims (4)

[Claims] 1. A pair of measuring jaws slidably provided on a case body, a driving device for opening and closing the measuring jaws, and a measured value based on a change in the position of the measuring jaws when a work is measured by the measuring jaws. An automatic sizing head comprising: a detector that outputs a signal; and a lever extending into the case body is connected to a rear end of the pair of measurement jaws. An arm protruding toward the other lever is provided, and a measuring jaw is swung at a distal end of the arm in a direction opposite to a measuring direction of the workpiece by an operation of a driving device disposed in the case body. An automatic sizing head, wherein a contact portion with the driving device is formed. 2. The air cylinder according to claim 1, wherein the driving device is an air cylinder that pushes and spreads a contact portion provided at a distal end portion of the arm portion with an extended rod end when the driving device is operated. Automatic sizing head described. 3. The method according to claim 1, wherein the contact portion provided at the tip portion of the arm portion is formed by crossing the tip portion of each arm portion and then facing the direction opposite to the projecting direction of the arm portion. The automatic sizing head according to claim 1, wherein: 4. The automatic sizing head according to claim 1, wherein a control board for adjusting a signal output from a detector is disposed in a space behind the lever in the case main body.