JPH11201710A - Contact type displacement measuring instrument and automatic sizing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contact type displacement measuring instrument capable of obtaining a constant measured pressure in a wide range and capable of optionally setting the measured pressure and to provide an automatic sizing device using it. SOLUTION: This contact type displacement measuring instrument is provided with a base 30, displacement members 32, 42 supported displaceably against the base 30, probes 34, 44 provided on the displacement members 32, 42 and kept in contact with the surface of a measured object 100, and displacement detecting means 35, 36; 45, 46 fixed to the base 30 and detecting the displacement of the displacement member 42. The displacement of the displacement member 42 in response to the contact positions of the probes 34, 44 with the measured object 100 is measured by the displacement detecting means 35, 36; 45, 46. The displacement measuring instrument is provided with air balancers 37, 47 biasing the displacement members 32, 42, and the contact pressures of the probes 34, 44 with the measured object 100 can be adjusted to the prescribed values by adjusting the biasing force to the displacement members 32, 42 by the air balancers 37, 47.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses an electric micrometer or the like which measures a surface position of a work by detecting a contact position of the probe with a probe in contact with the surface of a workpiece (work). A contact type dimension measuring device, and a dimensioner which measures a dimension of a work being processed using two such contact type dimension measuring instruments and outputs a signal called a dimensioning signal when a predetermined dimension value is reached. More particularly, the present invention relates to a contact type dimension measuring device and a dimensioning device in which a probe moves to a retracted position when a workpiece is replaced, moves to a predetermined position during measurement, and the probe contacts the workpiece at a predetermined contact pressure.

[0002]

2. Description of the Related Art As a device for measuring the surface position of a work, a contact type displacement measuring device such as an electric micrometer is widely used, but by combining two such contact type displacement measuring devices, the size of the work can be reduced. Can be measured. By using such a device for measuring the dimensions of a work, the dimensions of the work being processed are measured, and the processing operation is controlled in accordance with the detected value, thereby performing high-precision processing. Therefore, a dimension measuring device used for such a purpose is called an automatic sizing device.

When measuring the position or size of a surface with an electric micrometer or the like, it is necessary to bring the probe into contact with the surface of the work at a predetermined pressure. This contact pressure is called a measurement pressure. Generally, when performing very precise measurement, measurement is performed by reducing the measurement pressure and moving the work at a low speed, but the automatic sizing device for measuring the dimensions of the work being processed as described above. In such a case, the work is rotating at a high speed for processing and a cutting oil is supplied, so that a certain measurement pressure is required.

In a contact-type displacement measuring device such as an electric micrometer, a displacement member to which a tracing stylus in contact with the surface of a work is fixed is displaced in accordance with a contact position.
The position of the displacement member is detected. For example, in a measuring instrument using a differential transformer, an arm provided with a probe at one end and an iron core at the other end is rotatably supported around a fulcrum, and the arm rotates according to the position of the probe. Then, the position of the iron core changes, and the change in the position is detected by a differential transformer.

FIG. 1 shows such a contact-type displacement measuring device.
It is a figure showing the schematic structure of the automatic sizing device which used this. As shown in FIG. 1, the automatic sizing device includes fulcrums 4a, 4b
The armatures 2a and 2b rotatably supported are provided with probes 3a and 3b at one end and iron cores (cores) 5a and 5b at the other end. The arms 2a and 2b are springs 7a and 7b,
a, 3b are urged to press against the surface of the workpiece 100. According to the size of the work 100, the tracing stylus 3a, 3b
When the contact position between the arm 2a and the workpiece 100 changes,
2b rotates, and the positions of the cores 5a and 5b change. The cores 5a and 5b are located in the differential transformers 6a and 6b, and the outputs of the differential transformers 6a and 6b change according to the positions of the cores 5a and 5b. Therefore, by detecting a change in the output of the differential transformers 6a, 6b, the tracing stylus 3a, 3b and the workpiece 10 are detected.
The contact position of 0, that is, the dimension of the work 100 can be measured.

The set of the work 100 includes the arms 2a and 2
This is performed after b is spread vertically. This work 100
Is set manually, but may be set automatically by providing a retract mechanism. The automatic sizing device shown in FIG. 1 has a problem that the range of dimensions in which accurate measurement can be performed is limited because the rotational position of the arm changes depending on the size of the work. Therefore, there has been a demand for an automatic sizing device having a wide range of dimensions in which measurement can be performed so that works of various sizes can be measured by one device. FIG.
Is an example of an automatic sizing device having a wide measurement range. The upper displacement member 12 is a reference numeral 1 of the housing (body) 10.
A member 13 is connected to a parallel movement mechanism provided at a position indicated by reference numeral 1 and is held so as to be movable in a vertical direction.
The displacement member 12 is provided with a probe 14 and a core 15, and the displacement of the core 15 according to the contact position of the probe 14 is detected by a differential transformer 16 provided in the housing 10. Similarly,
The lower displacement member 22 can also be moved vertically by another parallel moving mechanism, and the core 2 corresponding to the contact position of the probe 24
5 is detected by the differential transformer 26 provided in the housing 10. The upper displacement member 12 is not provided with a spring or the like, and the contact pressure of the upper probe 14 with the workpiece 100 is the weight of the displacement member 12. Therefore, the measurement pressure is constant regardless of the size of the work 100. Lower displacement member 22
Will fall downward if it is not.
The contact pressure of the lower probe 24 with the workpiece 100 is a value obtained by subtracting the weight of the displacement member 22 from the force of the spring 27. Therefore, the length of the spring 27 changes according to the contact position, and the measurement pressure changes. Therefore, as shown in the figure, the change in the measured pressure is reduced by providing the spring 27 in the hole of the displacement member 22.

In the automatic sizing device shown in FIG.
Is constant regardless of the size of the work 100, but the measured pressure of the lower tracing stylus 24 changes according to the size of the work 100. As described above, a measure is taken to reduce the change in the measured pressure, but it cannot be made completely constant. In addition to the automatic sizing device shown in FIGS. 1 and 2, a device in which a sliding portion is eliminated by using a plate spring has been considered. Therefore, there is a problem that the measurement pressure changes and the measurement pressure also changes greatly.

[0008]

As described above, in the conventional contact-type displacement measuring device and the automatic sizing device using the same, the measuring pressure is obtained by biasing at least a part using a spring. Therefore, there is a problem that the measurement pressure changes depending on the size of the work. In addition, even if the dimensions are the same, there is an optimum measurement pressure depending on the material.However, with a conventional contact-type displacement measuring device and an automatic sizing device using the same, the measurement pressure is constant and must be set arbitrarily. Could not.

The present invention has been made to solve such a problem, and a contact-type displacement measuring instrument capable of obtaining a constant measurement pressure over a wide range irrespective of the size of a work and capable of arbitrarily setting the measurement pressure. And an automatic sizing device using the same.

[0010]

The contact displacement measuring device of the present invention utilizes an air balancer to achieve the above object. The air balancer is a device in which the contact at the tip moves and can urge the contact with the contact at an arbitrary pressure. Therefore, if the displacement member is urged by the contact of the air balancer, a predetermined measurement pressure can be obtained regardless of the position of the displacement member, that is, the size of the work.

That is, the contact-type displacement measuring device of the present invention comprises:
A base, a displacement member supported displaceably with respect to the base, a probe provided on the displacement member and in contact with the surface of the object to be measured, and a displacement detection means fixed to the base and detecting displacement of the displacement member A contact type displacement measuring device for measuring displacement of a displacement member according to a contact position of a probe with an object to be measured by a displacement detecting means, comprising an air balancer for urging the displacement member, and a displacement by the air balancer. The contact pressure of the tracing stylus on the object to be measured can be adjusted to a predetermined value by adjusting the urging force applied to the member.

When the displacement member is supported so as to be movable in the vertical direction, and when the displacement member descends due to its own weight when the displacement member does not urge at all, when the air balancer is displaced by its own weight, the air balancer is moved in the opposite direction. If it is arranged to urge in the direction, the displacement member can be displaced by changing the urging force of the air balancer to the displacement member. More specifically, if the biasing force of the air balancer is smaller than the weight of the displacement member, the displacement decreases, and if the biasing force increases, the displacement increases. By utilizing this, the displacement member can be moved between the retracted position and the measurement position.

The air balancer has an air supply port and an exhaust port, and can change the urging force to the displacement member by changing the gas pressure of the air supply port and the exhaust port. And the gas pressure adjusting means for adjusting the gas pressure at the exhaust port, it is possible to adjust the urging force. If such a contact type displacement measuring device is used in an automatic sizing device, an automatic sizing device that can set a measurement pressure arbitrarily in a wide range of dimensions can be realized.

[0014]

3 and 4 are views showing the configuration of an automatic sizing device according to an embodiment of the present invention. FIG. 3 shows a measurement state in which a probe contacts a workpiece, and FIG. The child is in a retracted state away from the work. The upper displacement member 32 is connected by a member 33 to a parallel movement mechanism provided at a position indicated by reference numeral 31 of the housing 30 and is held so as to be movable in the vertical direction. The displacement member 32 is provided with a probe 34 and a core 35, and the displacement of the core 35 according to the contact position of the probe 34 is detected by a differential transformer 36 provided in the housing 30.
Similarly, the lower displacement member 42 is also provided with the reference numeral 41 of the housing 30.
Can be moved in the vertical direction by another parallel movement mechanism provided at the position indicated by. The displacement of the core 45 in accordance with the contact position of the tracing stylus 44 is detected by the differential transformer 46 provided in the housing 30. Up to this point, it is the same as the conventional example. This embodiment is different from the related art in that an air balancer 37 for urging the displacement member 32 and an air balancer 47 for urging the displacement member 42 are provided.

In the state shown in FIG. 3, the upward biasing force of the air balancer 37 is smaller than the own weight of the displacement member 32, and the probe 34 subtracts the upward biasing force of the air balancer 37 from the own weight of the displacement member 32. The workpiece 100 is contacted with the contact pressure. The upward biasing force of the air balancer 47 is greater than the own weight of the displacement member 32, and the probe 44 uses the contact pressure obtained by subtracting the own weight of the displacement member 42 from the upward biasing force of the air balancer 47 to obtain the workpiece 100. Contact

When the measurement in the state of FIG. 3 is completed, if the upward biasing force of the air balancer 37 is made slightly larger than the weight of the displacement member 32, the displacement member 32 moves upward and hits a stopper (not shown). And stop. Also,
When the upward biasing force of the air balancer 47 is made slightly smaller than the weight of the displacement member 42, the displacement member 42 moves downward and stops at the lowest position of the air balancer 37. FIG. 4 shows this state, and the workpiece 100 is replaced in this state. When the machining line of the workpiece is automated, when the machining is completed, the workpiece 100 having been machined is removed in the state shown in FIG.
00 is automatically set.

FIGS. 5A and 5B show the structure of the air balancer 47. FIG. 5A shows a state where the contact is at the lowest position, and FIG. 5B shows a state where the contact is moved to the uppermost position. 37 is the same. In FIG. 5, reference numeral 51 is an air supply port, 52 is an exhaust port, 53 is a contact, 54 is a shaft, 55 is a piston, and 56 is a pneumatic chamber. In the state of (1) in FIG. 5, when air having a higher pressure (more precisely, a pressure obtained by adding the total weight of the displacement member 42 and the weight of the contact 53) to the air supply port 51 is introduced. Then, the piston 55 moves upward by air pressure, and the contact 53 rises to the state (2). In the state (2), the pressure of the air introduced into the exhaust port 52 is lower than the pressure of the air at the air supply port 51, and the contact 53 is raised by a force corresponding to the pressure difference. Accordingly, when the contact 53 supports the displacement member 42 from below, a difference between the force of the contact 53 rising and the weight of the displacement member 42 is applied to the displacement member 42. If this difference is positive, the displacement member 42 rises, and if it is negative, it falls. In the state of (2), when air having a lower pressure than the exhaust port 52 is introduced into the air supply port 51, the piston 55 moves downward, and the contact 53 also moves downward.

In the case of the air balancer 47, FIG.
In this state, the probe 44 contacts the work. Therefore, the pressure difference between the supply port 51 and the exhaust port 52 in the state (2) in FIG. 5 is determined by the upward force due to the pressure difference, the weight of the displacement member 42, the contact 53, the shaft 54, the piston 55, etc. It should be equal to the downward force of the total weight plus the measured pressure. Further, if the pressure difference between the air supply port 51 and the exhaust port 52 fluctuates in this state, the measured pressure fluctuates. Therefore, the pressure between the air supply port 51 and the air outlet 52 is set to a predetermined value by a regulator using a precision valve. Pressure must be maintained accurately and stably.

FIG. 6 shows the air supply port 51 of the air balancer 47.
FIG. 3 is a diagram showing a configuration of a system for applying air pressure to a gas outlet 52 and an exhaust port 52. As shown, the high-pressure air generated by the pump 61 is adjusted to a constant pressure by the regulator 62 and supplied to the air supply port 51. Similarly, the high-pressure air generated by the pump 71 is adjusted to a constant pressure by the regulator 72 and supplied to the exhaust port 52. The pressure in the regulators 71 and 72 can be adjusted by the control unit 73. The controller 73 controls the regulator 7 so that the air balancer 47 is in the state of (1) and (2) in FIG.
Adjust 1 and 72. When the pressure difference between the air supply port 51 and the exhaust port 52 is greatly changed, the contact 53 moves rapidly and the displacement member 42 moves rapidly, so that the pressure difference between the air supply port 51 and the exhaust port 52 becomes too sharp. It is important not to change. The mechanism that changes between the states (1) and (2) in FIG. 5 is called a retract mechanism. In this embodiment, a retract mechanism is realized using an air balancer.

The same applies to the air balancer 37. The measured pressure is the pressure obtained by subtracting the upward force due to the pressure difference between the air supply port 51 and the air discharge port 52 from the total weight of the displacement member 32 and the like. If the measurement pressure is fixed by the weight of the displacement member 32, an air cylinder can be used instead of the air balancer 37. As described above, the embodiment of the present invention has been described, but if an air balancer is used, it can be set to apply an arbitrary pressure at an arbitrary position.
The present invention is also applicable to a contact displacement measuring device using another mechanism.

[0021]

As described above, according to the present invention,
Since a contact-type displacement measuring device and an automatic sizing device that can perform measurement with a desired measurement pressure in a wide measurement range are realized, such measurement accuracy and processing accuracy can be improved. Further, by using an air balancer, a retracting mechanism called a retracting mechanism can be realized at the same time, so that the processing line can be automated.

[Brief description of the drawings]

FIG. 1 is a diagram showing a conventional example of an automatic sizing device.

FIG. 2 is a view showing another conventional example of an automatic sizing device.

FIG. 3 is a diagram illustrating a configuration of an automatic sizing device according to an embodiment of the present invention.

FIG. 4 is a diagram showing a state in which the automatic sizing device of the embodiment has changed.

FIG. 5 is a diagram showing a configuration of an air balancer used in the embodiment.

FIG. 6 is a diagram showing a system for supplying air pressure to an air balancer in the embodiment.

[Explanation of symbols]

 Reference Signs List 30 housing 31, 41 translation mechanism 32, 42 displacement member 34, 44 probe 35, 45 iron core 36, 46 differential transformer 37, 47 air balance

Claims (4)

[Claims] A base (30) and a displacement member (3) supported to be displaceable with respect to the base.
2 and 42), a probe (34, 44) provided on the displacement member and in contact with the surface of the device under test (100), and fixed to the base (30), and the displacement member (32,
42) displacement detecting means (35, 36; 4) for detecting the displacement
5, 46), and detects the displacement of the displacement member (32, 42) in accordance with the contact position of the probe (34, 44) with the object to be measured (100) by the displacement detection means (35, 3).
6; 45, 46), comprising: an air balancer (37, 47) for urging the displacement member (32, 42); and the displacement member by the air balancer (37, 47). The contact type wherein the contact pressure of the tracing stylus (34, 44) with the object to be measured (100) can be adjusted to a predetermined value by adjusting the biasing force to the (32, 42). Displacement measuring device. 2. The contact-type displacement measuring device according to claim 1, wherein the air balancer (37, 47) is arranged in a direction opposite to a direction in which the displacement member (32, 42) is displaced by its own weight. The displacement member (32, 42) is disposed to bias the displacement member (32, 42), and the displacement member (3) of the air balancer (37, 47) is arranged.
A contact-type displacement measuring device capable of displacing the displacement member (32, 42) by changing the biasing force on the contact member (2, 42). 3. The contact type displacement measuring device according to claim 1, wherein the air balancer (37, 47) has an air supply port (51).
And an exhaust port (52), and by changing the gas pressure of the air supply port (51) and the exhaust port (52), the urging force on the displacement member (32, 42) can be changed. A contact-type displacement measuring device, comprising: gas pressure adjusting means (62, 72) for adjusting gas pressures of the air supply port (51) and the exhaust port (52). 4. An automatic sizing device for measuring a dimension of a processed portion of a workpiece to be processed and outputting a sizing signal when the detected dimension has reached a predetermined value. An automatic sizing device comprising the contact-type displacement measuring device according to any one of the preceding claims.