JP5291517B2 - Inner dimension measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for measuring an internal size which is applicable to a cylinder gage with a small diameter, has a simple structure, and enables accurate measurement of the internal size. <P>SOLUTION: The device for measuring the internal size includes: a plurality of contacts 110 in contact with an object to be measured; a bottomed cylindrical member 120 provided inside the plurality of contacts 110, having a space 136 inside itself and having the space 136 deforming by a change in distance between the plurality of contacts 110; and a displacement sensor 140 put on the opening 120A of the bottomed cylindrical member 120 to seal the space 136 and also for detecting an amount of flexure of itself caused by the deformation of the space 136. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an inner dimension measuring instrument, and more particularly to a high-resolution inner dimension measuring instrument that can be incorporated in a narrow gap such as a small-diameter cylinder gauge probe.

  A cylinder gauge is known as an inner dimension measuring instrument for measuring the hole diameter, groove width, and the like of an object to be measured. The conventional small-diameter cylinder gauge uses a method in which the displacement in the diametrical direction of the inner wall of the object to be measured is converted into an orthogonal direction using a mechanical mechanism and transmitted. For example, in Patent Document 1, the amount of displacement between a pair of contacts is transmitted via a cam to a rod disposed in a direction orthogonal to the direction in which the pair of contacts are disposed. The amount of displacement is displayed on the display.

JP 2003-28603 A

  However, the inner dimension measuring instrument as shown in Patent Document 1 is complicated in its structure. For example, when applied to a small-diameter cylinder gauge having a diameter of several millimeters or less, each of the contact, cam, and rod is used. The effects of backlash and friction become relatively large, making it difficult to measure with high accuracy. At the same time, the contactors used are required to have high processing accuracy, and it is difficult to produce them, resulting in high costs.

  The present invention has been made to solve the above-mentioned conventional problems, and it is an object of the present invention to have a simple configuration, be applicable to a small-diameter cylinder gauge, and enable highly accurate inner dimension measurement.

The invention according to claim 1 of the present application includes a plurality of contact portions that are in contact with an object to be measured, and a space that is disposed inside the plurality of contact portions and that is deformed by a change in the distance between the plurality of contact portions. A bottomed tubular member provided inside, and a displacement sensor that is attached to the opening of the bottomed tubular member so as to seal the space, and detects an amount of bending of the space due to deformation of the space. The bottomed cylindrical member further includes a plurality of elastic portions on the outer periphery, and the plurality of elastic portions are in contact with the inside of the plurality of contact portions, thereby solving the problem.

In the invention according to claim 2 of the present application, the plurality of elastic portions are formed in a convex shape , and the plurality of elastic portions are brought into contact with the insides of the plurality of contact portions at points.

  According to a third aspect of the present invention, at least the displacement sensor is manufactured by a MEMS process. Here, the MEMS (Micro Electro Mechanical Systems) process is a composite of mechanical, electronic, optical, chemical, etc. by semiconductor microfabrication technology such as photolithography technology, thin film forming technology, and etching technology mainly performed on a silicon substrate. A process for manufacturing a microstructure with integrated functions.

  In the invention according to claim 4 of the present application, the displacement sensor is formed of an SOI substrate, and the amount of bending caused by the deformation of the space is detected as a change in capacitance. Here, the SOI (Silicon On Insulator) substrate refers to a substrate including single crystal silicon which is an active layer on an insulating layer on a base material layer.

  According to a fifth aspect of the present invention, the bottomed cylindrical member is provided with a temperature sensor.

  Moreover, the invention which concerns on Claim 6 of this application provides the opening part of the said bottomed cylindrical member in the direction orthogonal to the direction where these contact parts are arrange | positioned.

  According to the present invention, it is possible to measure the inner dimension with a simple configuration and high accuracy. For this reason, it is possible to provide a high-performance inner dimension measuring instrument at a low cost. When at least the displacement sensor is manufactured by the MEMS process, it is possible to measure the inner dimension with high accuracy particularly for a small-diameter cylinder gauge.

1 is a schematic perspective view of an inner diameter measuring instrument that is an inner dimension measuring instrument according to a first embodiment of the present invention. Similarly, a longitudinal cross-sectional schematic diagram of the inner diameter measuring instrument Similarly, a cross-sectional schematic diagram of the inner diameter measuring instrument Schematic diagram of the contact part of the inner diameter measuring device Similarly, an exploded view of the cylindrical part of the inner diameter measuring instrument

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

  1 is a schematic perspective view of an inner diameter measuring instrument which is an inner dimension measuring instrument according to the first embodiment of the present invention, FIG. 2 is a schematic longitudinal sectional view of the inner diameter measuring instrument, and FIG. FIG. 4 is a schematic diagram of a contact portion of the inner diameter measuring device, and FIG. 5 is an exploded schematic diagram of a cylindrical portion of the inner diameter measuring device. In addition, each figure does not necessarily represent the magnitude | size of a component correctly.

  First, the configuration of the present embodiment will be described.

  As shown mainly in FIGS. 1 to 3, the inner diameter measuring device 100 is a contact member (contact) 102 that is in direct contact with an object to be measured (its inner wall) and a displacement transmitted via the contact member 102 as an electrical signal. And a base member 172 that integrally fixes the contact member 102 and the sensor member 111 to each other. Furthermore, the sensor member 111 amplifies the output of the displacement sensor 140, which mainly includes a bottomed cylindrical member 120 disposed inside the contact member 102, a displacement sensor 140 having a membrane structure (film-like structure) 150, and the like. And an electrical component cell 170 to be provided. In the present embodiment, the size of the inner diameter measuring instrument 100 is 1 mm or less in both the vertical and horizontal width directions. However, the present invention is not necessarily limited to 1 mm or less in each direction.

  As shown in FIG. 4, the contact member 102 includes a support portion 104, a beam portion 106, a cover portion 108, and a contact portion 110. As shown in FIG. 2, the support part 104 fixes the contact part 110 provided on each cover part 108 to the displacement sensor 140 via a plurality of beam parts 106. As shown in FIG. 2, in this embodiment, the support portion 104 has a ring shape that is continuous in the circumferential direction, and is integrated with all the beam portions 106 (two in this embodiment) together with the cover portion 108. Molded. That is, except for the contact portion 110, the contact member 102 can be easily molded integrally from a cylindrical member. The support portion 104 is fixed to the outer periphery of the base member 172.

  As shown in FIG. 4, the beam portion 106 is formed to have a narrow width in the circumferential direction (in this embodiment, a narrower width than the cover portion 108), and supports each cover portion 108 in the central axis O direction. For this reason, even if the force Fv (FIG. 2) in the direction of the central axis O is applied, the cover portion 108 can be supported so as not to transmit the force to the inside of the cover portion 108. At the same time, the cover 108 can be displaced with high sensitivity to a force Fh (FIG. 2) in a direction toward the central axis O (referred to as a radial direction).

  As shown in FIG. 4, each of the cover portions 108 is formed integrally with the beam portion 106, and a plurality (two in this embodiment) are arranged at equal intervals in the circumferential direction. Note that the circumferential width of the cover portion 108 does not necessarily need to be wider than the circumferential width of the beam portion 106. The cover part 108 can secure the area of the surface inside the cover part 108 even if the area where the elastic part 126 of the bottomed tubular member 120 deforms expands from a point to a surface when the elastic part 126 of the bottomed cylindrical member 120 is deformed, and As long as the contact portion 110 can be stably supported, the width may be equal to or smaller than that of the beam portion 106.

  As shown in FIG. 4, the contact portions 110 are provided on the cover portions 108. And the outer surface of the contact part 110 becomes a part which contacts the hollow part surface (inner wall) of a to-be-measured object. Since the shape of the contact part 110 is a spherical shape and contacts the object to be measured at one point on the surface, it can be accurately displaced with high sensitivity. For the contact portion 110, it is preferable to use a cemented carbide sphere excellent in wear resistance (main component is tungsten carbide).

  With such a configuration of the contact member 102, even if a force in the central axis O direction (arrow Fv in FIG. 2) is applied to the contact portion 110, the force Fv is received by the support portion 104, and the contact portion 110 Transmission to the bottomed cylindrical member 120 arranged on the inner side can be prevented. At the same time, only the radial displacement (arrow Fh in FIG. 2) can be accurately transmitted to the bottomed tubular member 120. That is, the contact member 102 has a simple structure, but accurately transmits the position change in the radial direction of the contact portion 110 to the bottomed tubular member 120 with high sensitivity, so that the bottomed tubular member 120 is damaged or worn. This can prevent the bottomed cylindrical member 120 from extending its life.

  As shown in FIG. 1, the bottomed cylindrical member 120 mainly includes a cylindrical portion 122, an elastic portion 126, and a bottom portion 128. The cylindrical portion 122 is a cylindrical hollow pipe having an outer diameter of about 600 μm, and on its side surface, corresponding to the position of the contact portion 110, an elastic portion hole 124 for projecting the convex elastic portion 126 to the outer periphery (see FIG. 2 and FIG. 5) are provided at equal intervals (two in this embodiment). As shown in FIG. 5, the elastic portion 126 is made of a highly deformable material such as silicone rubber, and has a convex portion 126A and an outer peripheral portion 126B. The tip portion of the convex portion 126A is configured to contact with the inside of the contact portion 110 (strictly, the cover portion 108 that supports the contact portion 110) with a point. The inner side of the convex portion 126A is formed in a concave shape following the outer shape (not necessarily a concave shape). The outer peripheral portion 126B is larger than the elastic portion hole 124, and by sealing and fixing the outer peripheral portion 126B from the inside of the cylindrical portion 122, the sealing property of the space 136 inside the cylindrical portion 122 is ensured. For this reason, the displacement of the contact portion 110 in the radial direction is accurately transmitted to the elastic portion 126 with high sensitivity, and the elastic portion 126 is deformed while maintaining the sealing property of the space 136.

  As shown in FIG. 2, the bottom portion 128 of the bottomed tubular member 120 maintains the sealed state of the space 136 without being deformed together with the tubular portion 122. For this reason, the bottom portion 128 is made of a material having the same rigidity as the cylindrical portion 122 and is bonded to the lower portion of the cylindrical portion 122. A thin film temperature sensor 130 (FIG. 1) is formed on the outer periphery of the cylindrical portion 122. For this reason, it becomes possible to measure use environment temperature as the internal diameter measuring device 100, without preparing a temperature sensor separately. In other words, the inner diameter measuring device 100 can correct each coefficient of thermal expansion of the constituent member and also measure the temperature change in the space 136, thereby enabling highly accurate dimension measurement. In addition, the temperature sensor 130 may be directly formed on the outer periphery of the cylinder part 122, or the temperature sensor 130 after being formed separately may be attached to the cylinder part 122 later.

  As shown in FIG. 2, the displacement sensor 140 is attached to the opening 120 </ b> A of the bottomed cylindrical member 120 via the seal member 134. And the space 136 inside the bottomed cylindrical member 120 is sealed. The space 136 is filled with air or hydraulic oil (preferably fluid and low in reactivity and capable of extending the sealing performance), and each member is severely bonded with an adhesive or the like so as not to leak. Sealed.

  As shown in FIG. 2, the displacement sensor 140 includes an SOI (Silicon On Insulator) substrate 142 and a glass substrate 160 and is manufactured by a MEMS process. The MEMS (Micro Electro Mechanical Systems) process is a combination of mechanical, electronic, optical, and chemical functions such as photolithography technology, thin film forming technology, and semiconductor micromachining technology such as etching technology, which are mainly performed on silicon substrates. This is a process for manufacturing a structured microstructure. The SOI substrate 142 includes a silicon base layer 144, an insulating layer 146, and an active layer 148.

  The production of the displacement sensor 140 shown in FIG. 2 will be described below. A recess 152 is formed in the active layer 148 by using a photolithography technique and an etching technique. In addition, the membrane structure 150 is formed by removing the base material layer 144 to the insulating layer 146 in a range slightly narrower than the recess 152. The depth of the recess 152 is such that when the glass substrate 160 is bonded, the gap G between the opposing surface of the membrane structure 150 (the upper surface of the membrane structure 150 in FIG. 2) and the electrode film 162 is 2 to 3 μm. It forms so that it may become. An electrode film 162 is formed on the surface of the glass substrate 160 in a region facing the recess 152 by a thin film forming technique. Then, the active layer 148 and the glass substrate 160 are anodically bonded while the electrode film 162 is opposed to the membrane structure 150. Here, the through hole 164 is provided for electrical connection with the electrode film 162, and the through holes 166 and 168 are provided for electrical connection with the active layer 148. That is, the displacement sensor 140 can detect the amount of deflection of the membrane structure 150 (displacement sensor 140) in the central axis O direction through the through holes 164 to 168 in the form of a change in electric capacity.

  The electrical cell 170 is attached to the other surface (the upper surface in FIG. 2) of the glass substrate 160. The electrical cell 170 has a cylindrical outer shape, and houses a preamplifier that amplifies the output of the displacement sensor 140, wiring to the temperature sensor 130, and the like (not shown in FIG. 2).

  The electrical cell 170 is fixed to the base member 172 on the upper side in FIG. A mounting pin 174 is provided on the base member 172. The mounting pin 174 is mechanically fixed to a measuring element to which the inner diameter measuring device 100 is mounted. At the same time, electrical connection with the electrical cell 170 is made.

  Next, the operation of the inner diameter measuring device 100 will be described.

  The entire inner diameter measuring device 100 is inserted into a small workpiece having an inner diameter smaller than the outer diameter of the contact portion 110 of the inner diameter measuring device 100, which is the object to be measured. Then, the contact portion 110 is pushed by the inner wall of the small diameter workpiece. The contact part 110 moves inward, and the distance between the two contact parts 110 decreases. At this time, since the contact part 110 contacts the object to be measured at one point of the tip, the displacement obtained by the contact part 110 becomes more accurate and sensitive than the case of contacting the object to be measured at a plurality of points. .

  Due to the inward displacement of the contact part 110, the elastic part 126 is pushed toward the central axis O in the radial direction, and the space 136 is deformed. Since the space 136 is sealed, the pressure in the space 136 changes due to the deformation of the space 136. Due to this pressure change, the membrane structure 150 of the displacement sensor 140 attached in the direction of the central axis O perpendicular to the direction in which the two contact portions 110 are arranged is pushed, and the center of the membrane structure 150 is bent. In addition, since each elastic part 126 contact | abuts inside each cover part 108 (contact part 110) at one point, the bending amount of the membrane structure part 150 contact | abuts the change of the distance between the contact parts 110 in several points. More accurate and sensitive.

  The distance between the membrane structure 150 and the electrode film 162 changes in the central axis O direction due to the deflection of the central part of the membrane structure 150, so that the capacitance between the membrane structure 150 and the electrode film 162 changes. Will be. At this time, the change in the capacitance due to the change in the distance between the membrane structure 150 and the electrode film 162 is minute, but the change in the capacitance is amplified in the electrical cell 170 adjacent to the displacement sensor 140. For this reason, in the electric equipment cell 170, the influence of noise can be amplified to the minimum. Here, since the change amount of the capacitance is substantially proportional to the change amount of the contact portion 110, the distance between the contact portions 110 can be determined by examining the change amount of the amplified capacitance that is the output from the mounting pin 174. Can be obtained in a state where the influence of noise is small (a state where there is little error) (detection of the amount of deflection by the displacement sensor 140).

  As described above, since the displacement sensor 140 is manufactured by using the MEMS process, the displacement sensor 140 is small and can be collectively processed, and the characteristic variation can be reduced at low cost. Furthermore, since the capacitance type displacement sensor 140 using the SOI substrate 142 is used, the membrane structure 150 can be easily formed with less man-hours, the displacement sensor 140 can be manufactured with a high yield, and its characteristics can be further stabilized. . For this reason, the inner diameter measuring instrument 100 incorporating the displacement sensor 140 can be easily reduced in size, and at the same time, higher performance can be achieved.

  Further, since the displacement sensor 140 is attached to the opening 120A of the bottomed cylindrical member 120 provided in a direction (center axis O direction) orthogonal to the direction in which the contact portion 110 is arranged, the displacement sensor 140 is temporarily assumed. Even if the thickness of the electrode is thick, the distance between the contact portions 110 can be reduced without affecting the distance, and even an inner diameter of a very small gap of 1 mm or less can be measured.

  Even when the environmental temperature changes, more accurate measurement can be performed by correcting the variation in capacitance due to the temperature change by the output from the temperature sensor 130, compared to the case where the temperature is not corrected. Is possible. In addition, since the temperature sensor 130 is integrated, a small size measurement is possible.

  Therefore, according to the present invention, it is possible to measure the inner dimension with high accuracy and high resolution while the configuration of the inner diameter measuring instrument 100 is simple. For this reason, it is possible to provide a high-performance inner diameter measuring instrument 100 as an inner dimension measuring instrument at a low cost. And since the displacement sensor 140 is manufactured by the MEMS process, it can be applied to a small-diameter cylinder gauge, and highly accurate inner dimension measurement is possible.

  Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the above embodiment. That is, it goes without saying that improvements and design changes can be made without departing from the scope of the present invention.

  In the present embodiment, the small-diameter cylinder gauge is targeted, but the present invention is not limited to this, and may be applied to a large-diameter.

  In the present embodiment, there are two contact portions 110 and two elastic portions 126, but the present invention is not limited to this. For example, three or more of each may be provided. In that case, the inner diameter can be measured more accurately.

  Moreover, in this embodiment, although the some elastic part 126 contact | abutted inside each of the some contact part 110 with a point, this invention is not limited to this. For example, the contact portion may be abutted on the surface, or a film-like contact portion may be directly formed on the surface of the elastic portion without having a supporting portion. In this case, it is possible to provide a low-cost inner dimension measuring instrument having a simpler configuration.

  In the present embodiment, the displacement sensor 140 is manufactured by the MEMS process, but the present invention is not limited to this. For example, if the entire configuration of the inner dimension measuring device is manufactured by the MEMS process, a larger amount of the inner dimension measuring device can be provided in a larger amount. Further, even if no MEMS process is used, the configuration is simple and the size can be reduced to some extent. Thus, a highly accurate inner dimension measuring instrument can be provided at a lower cost than in the prior art.

  In the present embodiment, the displacement sensor 140 is formed on the SOI substrate 142 and detects the amount of bending of the membrane structure 150 (displacement sensor 140) caused by the deformation of the space 136 as a change in capacitance. However, the present invention is not limited to this. For example, even when the MEMS process is used, when the SOI substrate is not used, the substrate cost can be reduced, so that a low-cost displacement sensor can be provided. Further, the displacement sensor may be a displacement sensor that utilizes the fact that the deflection is measured by a resistance change, for example, without using a change in capacitance.

  Moreover, in this embodiment, although the temperature sensor 130 was provided in the bottomed cylindrical member 120, this invention is not limited to this. For example, when the temperature sensor is not provided, the cost can be further reduced, and the temperature sensor can be arranged separately from the inner dimension measuring device and the correction by the temperature can be performed.

  In the present embodiment, the displacement sensor 140 is attached to the opening 120A of the bottomed cylindrical member 120 provided in a direction (center axis O direction) orthogonal to the direction in which the contact portion 110 is disposed. However, the present invention is not limited to this. For example, the direction of the opening 120A may be the direction in which the contact portion is disposed, or may be any direction that is not orthogonal.

  In the present embodiment, the contact member 102 is formed from a cylindrical member and the cylindrical portion 122 is a cylindrical hollow pipe. However, the present invention is not limited to this. For example, these may be hollow members having a polygonal cross section.

  In the present embodiment, the displacement sensor 140 is substantially circular as shown in FIG. 2, but the present invention is not limited to this. For example, it may be a polygon. In this case, the displacement sensor can be easily formed, and the number of pieces taken from the SOI substrate can be increased by devising the layout on the SOI substrate.

DESCRIPTION OF SYMBOLS 100 ... Inner diameter measuring device 102 ... Contact member 104 ... Support part
DESCRIPTION OF SYMBOLS 106 ... Beam part 108 ... Cover part 110 ... Contact part 111 ... Sensor member 120 ... Bottomed cylindrical member 122 ... Tube part 124 ... Elastic part hole 126 ... Elastic part 128 ... Bottom part 130 ... Temperature sensor 134 ... Seal member 136 ... Space 140 ... Displacement sensor 142 ... SOI substrate 144 ... Base material layer 146 ... Insulating layer 148 ... Active layer 150 ... Membrane structure part 152 ... Recessed part 160 ... Glass substrate 162 ... Electrode film 164, 166, 168 ... Through-hole 170 ... Electrical equipment cell 172 ... Base member 174 ... Mounting pin

Claims (6)

A plurality of contact portions that contact the object to be measured;
A bottomed cylindrical member that is disposed inside the plurality of contact portions and has a space that is deformed by a change in the distance between the plurality of contact portions,
A displacement sensor that is attached to the opening of the bottomed tubular member so as to seal the space, and that detects a deflection amount of the space caused by deformation of the space;
Equipped with a,
Bottomed tubular member further comprises a plurality of resilient portions on the outer periphery, the inner sizer characterized that you contact resilient portions of said plurality of inside said plurality of contact portions. The inner dimension measuring instrument according to claim 1, wherein the plurality of elastic portions are formed in a convex shape, and the plurality of elastic portions abut on the inner sides of the plurality of contact portions at points.   The inner dimension measuring instrument according to claim 1, wherein at least the displacement sensor is manufactured by a MEMS process.   4. The inner dimension measuring instrument according to claim 3, wherein the displacement sensor is formed on an SOI substrate and detects an amount of deflection caused by deformation of the space as a change in capacitance.   The inside dimension measuring instrument according to any one of claims 1 to 4, wherein a temperature sensor is provided in the bottomed cylindrical member.   The inner dimension measuring instrument according to any one of claims 1 to 5, wherein the opening of the bottomed cylindrical member is provided in a direction orthogonal to a direction in which the plurality of contact portions are arranged.

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