JP4905833B2 - Inner diameter measuring device and inner diameter measuring method - Google Patents

Description

  The present invention relates to a hole inner diameter measuring apparatus and inner diameter measuring method for measuring the inner diameter of a hole formed in a workpiece.

  As a measuring device that measures the inner diameter of a hole, a three-dimensional measuring instrument that performs measurement by bringing a probe into contact with the inner diameter surface of the hole or a measuring head is inserted into the hole, and the nozzle of the measuring head is directed toward the wall surface of the hole. An air micrometer that injects compressed air and detects the back pressure of the nozzle has been conventionally used.

  In the three-dimensional measuring apparatus, the measuring element brought into contact with the inner wall of the hole makes one round along the shape of the hole, and the inner diameter of the hole is calculated from the amount of displacement. The inner diameter at each position of the hole is calculated by moving the measuring element in the depth direction of the hole and bringing the measuring element into contact with the inner wall of the hole at each position to make a round.

  In the air micrometer, the back pressure of the nozzle depends on the distance between the inner wall of the hole and the nozzle, so the measurement value can be measured by converting the detected value into the inner diameter of the hole by comparing with the master reference value obtained in advance. Done. Such an air micrometer continuously measures the inner diameter of the hole while putting the measuring head in and out of the hole.

  However, in such an inner diameter measuring apparatus, after moving the measuring element at the measuring position, the measuring element is further moved to another measuring position, and the measuring element is similarly moved at the measuring position. There was a problem that took time. Furthermore, with such a measuring apparatus, it is difficult to put a measuring head into a small diameter hole, and it is also difficult to measure a curved hole.

Therefore, it is easy to measure even a small-diameter hole at high speed, and as a measurement device and measurement method that can quickly measure the inner diameter of a hole, a floating element supported by an elastic body is placed in the hole and fluid is supplied to the hole. A measuring apparatus and a measuring method for measuring the inner diameter of a hole by a back pressure, a flow rate when the fluid passes between the float and the hole wall surface, or a drag force applied to the float have been proposed.
JP 2001-349721 A

  In the measuring apparatus described in Patent Document 1, air is supplied to a hole formed in an object to be measured placed on a table, the float is inserted into the hole, and the float is moved in the hole by the moving means. The inner diameter at each position of the hole is measured.

  However, in such a measurement, in the vicinity of the entrance of the hole on the fluid supply side, the difference between the position of the hole of the object to be measured and the position of the hole supplying the fluid, the size of the hole, etc. A step is created from the air flow, and the air flow is easily changed. Therefore, in the vicinity of the entrance of the hole, as shown in graph A in FIG. 4, a back pressure value higher than the back pressure value that should be measured from the actual inner diameter is measured, and the inner diameter is measured to be smaller than the actual inner pressure. There was a problem that would occur.

  The present invention has been made to cope with such a problem, and it is possible to suppress the change in back pressure near the entrance of the hole formed in the object to be measured and to accurately measure the inner diameter of the hole. It is an object to provide an inner diameter measuring device and an inner diameter measuring method that are possible.

In order to achieve the above object, the present invention provides an object receiving member on which the object to be measured is placed by contacting a reference surface around the entrance of a through hole formed in the object to be measured; A fluid supply means for supplying a fluid to the through hole formed in the object to be measured through the object receiving member, and a periphery of a portion of the object receiving member in contact with the object to be measured And a seal member that contacts the fluid and seals between the measured object and the measured object receiving member to prevent the fluid from flowing out, and a float that is held by an elastic member and inserted into the hole And a moving means for moving the float along the depth direction of the through hole, and a back pressure, a flow rate, or a drag force that the float receives when the fluid passes through a gap between the inner wall of the through hole and the float. Detecting means for detecting, and the detecting means The detection value out is compared with a reference value and a conversion means for converting the inner diameter of the through hole, wherein the object to be measured receiving member side end of the inlet around the through hole formed in the object to be measured A flat surface with which a reference surface comes into contact is formed, and a plurality of radially extending grooves are formed on the flat surface, and the seal member and the fluid are in contact with each other by the grooves .

  Further, the present invention is characterized in that in the above invention, the seal member is formed of an elastic body.

Further, in the present invention is the invention, the object to be measured receiving member has a cylindrical shape having a flange portion having holes formed in communication with the through hole in the center, the sealing member before Symbol flange on It is characterized in that is attached.

  According to the present invention, the object to be measured is placed on the object receiving member with the flat surface serving as the reference surface around the hole formed being in close contact with the object receiving member, and is formed on the object to be measured. The hole is aligned with the hole communicating with the fluid supply means formed in the object receiving member. As a result, the object to be measured is fixed with the surface serving as a reference for the position from the hole entrance closely contacting the flat surface of the object receiving member serving as a reference for measuring the position of the float from the hole entrance.

  In this state, the float supported by the elastic body is inserted into the measured object hole from the measured object receiving member side, and fluid such as compressed air is supplied from the fluid supply means to the measured object hole. Supplied from the receiving member side. The float is moved in the depth direction of the hole by the moving means, and the back pressure, the flow rate, or the drag that the float receives when the fluid passes through the gap between the hole inner wall and the float is detected at a plurality of locations by the detection means. The detection value detected by the detection means is converted to the inner diameter of the hole by the conversion means in comparison with the reference value.

  At this time, the outer periphery or inner peripheral portion of the surface of the object receiving member that is in close contact with the object to be measured contacts the fluid and seals between the object to be measured and the object receiving member to be fluid A seal member is attached to prevent the liquid from flowing out of the gap between the object to be measured and the object receiving member. When the seal member is attached to the outer peripheral portion, a plurality of radially extending grooves are formed on the surface of the object receiving member that is in close contact with the object to be measured.

  As a result, since the fluid is in direct contact with the seal member, fluid disturbance near the entrance of the hole is eliminated, and changes in back pressure near the entrance of the hole formed in the object to be measured are suppressed. It becomes possible to measure the inner diameter.

  As described above, according to the inner diameter measuring device and the inner diameter measuring method of the present invention, accurate measurement of the inner diameter of the hole is performed by suppressing the change in the back pressure near the entrance of the hole formed in the object to be measured. Make it possible.

  Hereinafter, preferred embodiments of an inner diameter measuring device and an inner diameter measuring method according to the present invention will be described in detail with reference to the accompanying drawings.

  First, the configuration of the inner diameter measuring apparatus according to the present invention will be described. FIG. 1 is a block diagram showing the configuration of the inner diameter measuring apparatus.

  As shown in FIG. 1, the measuring device 10 is a measurement object in which compressed air supplied from an air generation source 12 as fluid supply means is placed and fixed on a measurement part 20 through a movable part 30 as movement means. Is supplied to the through hole 22A formed in the workpiece 22, and the float 31 provided in the movable portion 30 is moved up and down in the through hole 22A to measure the inner diameter at each position of the through hole 22A.

  The workpiece 22 has a cylindrical shape, a through hole 22A is formed at the center, and the periphery of the inlet 22C of the through hole 22A is formed in a flat shape to serve as a reference surface for measuring the position of the through hole 22A. .

  The compressed air supplied from the air generation source 12 is dedusted by the filter 14, adjusted to a constant pressure by the regulator 16, and then sent to the control unit 11 as a conversion means by changing the air pressure and flow rate to an electric signal. It passes through a throttle installed in an A / E converter 18 (air / electric converter) as a means, and is supplied to a float support member 35 provided in the movable portion 30 via a connector 36.

  In addition to the float support member 35, the movable unit 30 includes a moving member 34, a support member 33, a drive unit 38, and a linear scale (not shown).

  The float support member 35 includes a flange portion 35B, an air flow path 35A is formed inside the bottom portion, and a float 31 that measures the inner diameter of the through hole 22A formed in the work 22 is a wire 32 that is an elastic member at the distal end portion. It is attached by.

  The float 31 is formed in a spherical shape with high processing accuracy using a material such as ceramic, resin, steel, and light alloy.

  The moving member 34 is hollow inside, and the flange portion 35B of the float support member 35 is fixed to the bottom so that the float support member 35 is located in the cavity. As a result, an air flow path 30 </ b> A is formed inside the moving member 34.

  The support member 33 has a hole 33A formed therein, and the moving member 34 is sealed in the hole 33A by the drive unit 38 whose operation is controlled by the control unit 11 together with the float support member 35 while the outer periphery is sealed by the seal ring 37. Move up and down.

  As a result, the float 31 can move up and down in the through hole 22 </ b> A formed in the workpiece 22. The moving amount of the float 31 is measured as the moving amount of the moving member 34 by a linear scale (not shown), and it can be seen which position the inner diameter of the float 31 is measured in the through hole 22A.

  Subsequently, the measuring unit 20 is fixed to the upper portion of the movable unit 30 and is a workpiece receiving member 23 that is an object receiving member, a fixing ring 27 that fixes a seal ring 25 that is a sealing member, a workpiece holding member 26, and a workpiece A holding part 24 is provided.

  As shown in FIG. 2, the workpiece receiving member 23 has a cylindrical shape having a flange portion with a hole 23 </ b> B formed in the center, and a flat surface 23 </ b> A is formed on the upper surface. The workpiece receiving member 23 receives the workpiece 22 when a reference plane around the entrance 22C of the through hole 22A formed in the workpiece 22 contacts the plane 23A.

  The flat surface 23A of the workpiece receiving member 23 is formed with radially extending grooves 23C, and the outer periphery of the flat surface 23A and the grooves 23C is attached with a seal ring 25 made of resin, rubber or the like on the flange portion. . The seal ring 25 is fixed to the work receiving member 23 by a fixing ring 27 attached around the work receiving member 23.

  The workpiece holding member 26 is formed with a hole for holding the workpiece 22 having a diameter slightly larger than the outer diameter of the workpiece 22 at the center, and the center of the through hole 22A of the workpiece 22 is the center of the hole 23B of the workpiece receiving member 23. Are attached to the upper part of the work receiving member 23 and the fixing ring 27 so as to be aligned in a straight line.

  The workpiece 22 held by the workpiece holding member 26 and placed on the flat surface 23A of the workpiece receiving member 23 is pressed by the workpiece pressing portion 24 on the surface opposite to the surface in contact with the flat surface 23A. It is in close contact with the member 23. At this time, the seal ring 25 is also pressed by the work 22 to seal between the work 22 and the work receiving member 23, and the compressed air passing through the hole 23 </ b> B and the through hole 22 </ b> A Prevent leakage from between.

  In this state, the compressed air supplied from the air generation source 12 is dust-removed by the filter 14, adjusted to a constant pressure by the regulator 16, and then installed in the A / E converter 18 (air / electric converter). The work passes through the restrictor, passes through the flow path 35A and the flow path 30A via the connector 36, flows from the hole 33A into the hole 23B of the work receiving member 23 and is supplied into the through hole 22A of the work 22, It is discharged into the atmosphere from the side pressed by 24.

  The compressed air supplied into the through hole 22A passes through the gap 22B between the float 31 that moves up and down in the through hole 22A and the inner wall of the through hole 22A, and the back when the compressed air passes through the gap 22B. The pressure is detected by the A / E converter 18. The detected magnitude is sent to the control unit 11 as an electrical signal, and the sent electrical signal is compared with the reference value recorded in the control unit 11 and converted into the inner diameter size of the through hole 22A and recorded. .

  The measuring device 10 having the above configuration measures the inner diameter of the workpiece 22. In the present embodiment, the workpiece 22 is formed in a tapered shape near the outer peripheral portion of the surface that contacts the workpiece receiving member 23, but is not tapered like the workpiece 42 as shown in FIG. Even if a taper shape is provided around the entrance 22C of the through hole 22A, the same measurement is performed.

  At this time, the workpiece receiving member has a counterbore formed in the inner peripheral portion of the flat surface 43A like the work receiving member 43 shown in FIG. 3, and a seal ring 45 is attached in the counterbore. The seal ring 45 seals between the workpiece 42 and the workpiece receiving member 43, and prevents the compressed air passing through the hole 43 </ b> B and the hole 42 </ b> A from flowing out between the workpiece 42 and the workpiece receiving member 43. .

  Similarly, the compressed air supplied into the hole 42A passes through the gap 42B between the float 31 that moves up and down in the hole 42A and the inner wall of the hole 42A, and the back pressure when the compressed air passes through the gap 42B. Is detected by the A / E converter 18 and the inner diameter is measured.

  In the present embodiment, the workpiece 22 has a cylindrical shape. However, the present invention is not limited to this, and any shape can be used as long as the workpiece has a hole and can be placed on the workpiece receiving member. However, it is possible to measure the inner diameter of the hole.

  Next, the operation of the measuring apparatus 10 according to the present invention configured as described above will be described. In the measuring apparatus 10 shown in FIG. 1, first, compressed air is supplied from an air generation source 12, and the supplied compressed air is dedusted by a filter 14, adjusted to a constant pressure by a regulator 16, and then an A / E converter 18. The air is passed through a throttle installed in the (air / electrical converter) and supplied to the float support member 35 via the connector 36.

  The compressed air supplied to the float support member 35 passes through the flow paths 35 </ b> A and 30 </ b> A, is supplied from the hole 33 to the hole 23 </ b> B of the work receiving member 23, and is injected into the through hole 22 </ b> A of the work 22.

  Next, the driving unit 38 is driven to raise both the moving member 34 and the float support member 35, and the float 31 is inserted into the through hole 22A from the hole 23B side, and the inserted float 31 is lifted along the through hole 22A. Let

  The back pressure when the compressed air passes through the gap 22B between the float 31 and the inner wall of the through hole 22A is detected by a plurality of (or continuously) A / E converters 18 at predetermined intervals. Since the back pressure depends on the size of the gap between the float 31 and the inner wall of the through hole 22A, the back pressure detected value detected by the A / E converter 18 is compared with the master reference value by the control unit 11. Can be converted into the inner diameter of the through hole 22A.

  At this time, the flat surface 23A in close contact with the work 22 of the work receiving member 23 is formed with a radially extending groove 23C shown in FIG. 2, and a seal ring 25 is attached to the outer periphery of the flat surface 23A and the groove 23C. .

  As a result, the compressed air comes into direct contact with the seal ring 25 through the groove 23C, and the disturbance of the compressed air in the vicinity of the inlet 22C of the through hole 22A is eliminated. As shown in the graph B in FIG. 4, a high back pressure value is measured and the inner diameter is not smaller than the actual one, and the accurate inner diameter of the through hole 22A near the entrance 22C is not measured. Measurement can be performed.

  In the measurement in the through hole 22A, an automatic centripetal action (or automatic centering action) is exerted on the float 31 by the compressed air passing through the gap 22B between the inner wall of the through hole 22A and the float 31. Therefore, the wire 32 is elastically deformed and the float 31 is automatically arranged at the center of the through hole 22A. As a result, the compressed air passes through the gap 22B formed substantially uniformly on the inner wall of the through hole 22A of the workpiece 22, and the A / E converter 18 detects the back pressure at this time, thereby detecting the through hole 22A. Can be measured accurately.

  Note that the master reference value is a value obtained by measuring the master under the same conditions as the measurement prior to measurement, and is performed each time the measurement conditions are changed.

  In the above-described embodiment, the back pressure of the compressed air is detected. However, the present invention is not limited to this, and the compressed air flows when the compressed air passes through the gap 22B between the inner wall of the through hole 22A and the float 31. The flow rate may be detected. Also in this case, similarly to the above-described embodiment, the control unit 11 can accurately measure the inner diameter of the through hole 22A by comparing the detected value with the reference value of the master.

  Furthermore, the present invention is not limited to the detection of the back pressure and flow rate of compressed air, but the drag force received by the float 31 is detected by a piezoelectric pickup or strain gauge (not shown) provided on the float support member 35, and penetrated. The inner diameter of the hole 22A may be converted.

  As described above, according to the inner diameter measuring apparatus and inner diameter measuring method according to the present invention, since the fluid is in direct contact with the seal member, the fluid turbulence near the entrance of the hole formed in the object to be measured. This eliminates the change in back pressure near the entrance of the hole and enables accurate measurement of the inner diameter of the hole.

The block diagram which showed the structure of the internal diameter measuring apparatus concerning this invention. The top view and side view which showed the shape of the workpiece | work receiving member. The side view which showed the measurement part of another embodiment. A chart showing the results of measuring the inner diameter of the workpiece.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Measuring apparatus, 11 ... Control part, 12 ... Air generation source, 16 ... Regulator, 18 ... A / E converter, 20 ... Measuring part, 22, 42 ... Workpiece (measurement object), 22A ... Through-hole, 23B , 33A, 42A ... hole, 22B ... gap, 22C ... entrance, 23, 43 ... work receiving member (measurement object receiving member), 23A, 43A ... plane, 24 ... work pressing part, 25, 37, 45 ... seal ring (Seal member), 27 ... fixed ring, 30 ... movable part, 30A, 35A ... flow path, 31 ... float, 32 ... wire (elastic member), 33 ... support member, 34 ... moving member, 35 ... float support member, 36 ... Connector, 38 ... Driver

Claims (4)

A measured object receiving member on which the measured object is placed by contacting a reference surface around the entrance of the through hole formed in the measured object;
Fluid supply means for supplying a fluid to the through hole formed in the measurement object via the measurement object receiving member;
The fluid to be measured is attached around the portion of the object receiving member in contact with the object to be measured and is in contact with the fluid to seal between the object to be measured and the object to be measured receiving member. A seal member for preventing the outflow of the gas, a float that is held by an elastic member and inserted into the hole, and a moving means that moves the float along the depth direction of the through hole,
Detecting means for detecting back pressure, flow rate, or drag received by the float when the fluid passes through a gap between the inner wall of the through hole and the float;
Conversion means for comparing the detection value detected by the detection means with a reference value and converting it to the inner diameter of the through hole
And
A flat surface is formed at the end of the object receiving member on the side where the reference surface around the entrance of the through hole formed in the object to be measured comes into contact, and a plurality of grooves extending radially are formed on the flat surface. An apparatus for measuring an inner diameter of a hole , wherein the seal member and the fluid are in contact with each other through the groove .   The hole inner diameter measuring apparatus according to claim 1, wherein the seal member is formed of an elastic body. Wherein said measured object receiving member, that a cylindrical shape having a flange portion having holes formed in communication with the through hole in the center, and wherein said that the sealing member is attached to the front Symbol flange on The hole inner diameter measuring device according to claim 1 or 2. An object to be measured is placed on the object receiving member, and a float held by an elastic body is inserted into a through hole formed in the object to be measured, and a fluid is supplied to the through hole, and the fluid passes through the through hole. In the inner diameter measuring method of the hole for measuring the inner diameter of the through hole by detecting the back pressure, the flow rate when passing through the gap between the inner wall of the hole and the float, or the drag received by the float,
A plurality of radially extending grooves are formed in a portion where the measured object receiving member is in contact with a reference surface around the entrance of the through hole formed in the measured object, and the measured object receiver A sealing member that seals a gap between the object to be measured and the object to be measured, which is attached to an outer peripheral portion of a part in contact with the object to be measured, and the fluid to prevent the fluid from flowing out; Are in contact with each other through the groove .

Images