WO2003048683A1 - Method and equipment for measuring shape of hole - Google Patents

Abstract

A measuring equipment (10) inserts a measuring ball (30) into the hole (22A) of a work (22) by lowering an arm (36) and lowers the measuring ball (30) along the depth direction of the hole (22A) and then detects the back pressure of compressed air at a plurality of positions by means of an A/E converter (18). The detected value is compared with the reference value of a master at a control section (20) and expressed in terms of the inside diameter of the hole (22A) thus measuring the shape of various holes.

Description

Hole shape measuring method and apparatus

Technical field

 The present invention relates to a hole shape measuring method and apparatus for measuring the shape of a hole formed in a work.

 Akita

Background art

 One of the measuring devices for measuring the shape of a hole is an air micrometer. A conventional air micrometer inserts a measurement head into a hole, injects compressed air from the nozzle of the measurement head toward the wall of the hole, and detects the back pressure of the nozzle. Since the back pressure of the nozzle depends on the distance between the inner wall of the hole and the nozzle, the detected value can be converted into the inner diameter of the hole by comparing it with a master reference value obtained in advance. With a conventional air micrometer, the shape of the hole can be determined by continuously measuring the inner diameter while moving the measurement head into and out of the hole.

 However, the conventional air micrometer cannot measure the shape of the bent or curved hole because the measurement head cannot be put in and out of the bent or curved hole. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a hole shape measuring method and apparatus capable of measuring various hole shapes.

Disclosure of the invention

In order to achieve the above object, a hole shape measuring method according to the present invention is a hole shape measuring method for measuring an inner diameter of a hole at a plurality of locations along a depth direction of the hole to obtain a shape of the hole. Then, a fluid is supplied to the hole, a float is inserted into the hole, and the fluid passes through a gap between the inner wall of the hole and the float while moving the float along a depth direction of the hole. Back pressure at the time, flow rate, and at least one of the drag received by the float is detected at a plurality of locations, The detected value is compared with a reference value and converted into the inner diameter of the hole. The hole shape measuring device according to the present invention is a hole shape measuring device for measuring the inner diameter of a hole at a plurality of locations along the depth direction of the hole to obtain the shape of the hole. A fluid supply means for supplying the fluid, a float inserted into the hole, a moving means for moving the float along a depth direction of the hole, and a fluid passing through a gap between an inner wall of the hole and the float. Detection means for detecting at least one of a back pressure, a flow rate, and a drag received by the float at a plurality of locations, and comparing a detection value detected by the detection means with a reference value to an inner diameter of the hole. And conversion means for converting.

 According to the present invention, the back pressure of the fluid, the flow rate, and the resistance received by the float are detected at a plurality of positions while inserting and moving the float in the hole to which the fluid is supplied, so that the inner diameter of the hole is determined by the depth of the hole. Can be measured at multiple locations. Thus, the shape of a hole having a non-uniform diameter, for example, a hole formed with a taper can be measured.

 The hole shape measuring method according to the present invention is a hole shape measuring method for measuring the center line of the hole to obtain the hole shape, wherein a fluid is supplied to the hole, and a float is inserted into the hole. Detecting the position of the float at a plurality of positions while moving the float along the depth direction of the hole, obtaining a center line of the hole from the detected value, and obtaining a shape of the hole based on the center line; It is characterized by .

Further, a hole shape measuring device according to the present invention is a hole shape measuring device for measuring a center line of a hole to acquire the shape of the hole, wherein a fluid supply means for supplying a fluid to the hole; It is characterized by comprising: a float to be inserted; moving means for moving the float along the depth direction of the hole; and position detecting means for detecting the position of the float at a plurality of locations. According to the present invention, when the float is inserted into the hole to which the fluid is supplied, the float moves to the center of the hole under the automatic centripetal action, so that the locus of the center position of the float matches the center line of the hole. Therefore, the center line of the hole can be obtained by detecting the position of the float at a plurality of locations. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a block diagram showing a structure of a first embodiment of a hole shape measuring device according to the present invention;

 FIG. 2 is a side sectional view showing a characteristic portion of the hole shape measuring device shown in FIG. 1; FIG. 3 is a block diagram showing a structure of a hole shape measuring device according to a second embodiment of the present invention. Fig.

 Fig. 4 is a side view showing a characteristic portion of the hole shape measuring device shown in Fig. 3;

 Figure 5 is a cross-sectional view along the line 5-5 in Figure 4;

 FIG. 6 is an explanatory view showing the operation of the hole shape measuring device shown in FIG.

 FIG. 7 is an explanatory view showing the operation of the hole shape measuring device shown in FIG.

 FIG. 8 is an explanatory view showing the operation of the hole shape measuring device shown in FIG.

 FIG. 9 is a block diagram showing the structure of the hole shape measuring device according to the third embodiment of the present invention;

 FIG. 10 is a side view showing a supporting structure of the measuring sphere different from that of FIG. 9;

 FIG. 11 is a sectional view taken along the line 11-11 in FIG. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, an embodiment of a hole shape measuring method and apparatus according to the present invention will be described with reference to the accompanying drawings.

 FIG. 1 is a block diagram illustrating a configuration of the measuring apparatus 10 according to the first embodiment. The measuring device 10 is a device for measuring the inner diameter of the hole 22 A of the work 22 at a plurality of locations in the axial direction of the hole 12 A.

 As shown in FIG. 1, the compressed air supplied from the air source 12 is dust-removed by the filter 14, adjusted to a constant pressure by the regulator 16, and then cooled by the A / E converter 18 (air The air is sent to the air supply passage 28 B in the measurement table 28 via the connector 33 through the restrictor installed in the (electric converter).

A supply port 28 A communicating with the air supply passage 28 B is formed on the upper surface of the measurement table 28, and the work 22 is placed on the supply port 28 A. A hole 22A is formed in the workpiece 22. Hole 22A is connected to supply port 28A. An air leak prevention seal (0 ring) 34 is provided around the supply port 28 A. The air leak prevention seal 34 allows air to leak from the gap between the measuring table 28 and the work 12. Is prevented. Thereby, the compressed air supplied to the air supply passage 28B is injected from the supply port 28A to the hole 22A without leaking.

 The compressed air injected into the hole 22A is blown out through the gap between the inner wall of the hole 22A and the measuring ball (corresponding to a float) 30. The A / E converter 18 converts the pressure at this time into an electric signal using a built-in bellows and a differential transformer, and outputs the electric signal to the control unit 20. When the diameter of the hole 22A is different, the pressure is slightly changed, and the control unit 20 calculates the inner diameter of the work 12 based on the changed electric signal as described later, and calculates the calculated data. One night is displayed on the monitor of the control unit 20, for example.

 The measuring ball 30 is formed in a spherical shape with high processing accuracy by using a material such as a ceramic, a resin, steel, or a light alloy. As shown in Fig. 2, the diameter d of the measuring ball 30 is set according to the inner diameter D of the hole 22A to be measured (the minimum diameter if the inner diameter is not constant) and the required sensitivity. Is set so that the difference (D-d) between d and d is approximately 10〃m to 100 0m. The smaller the difference (D-d) between D and d, the higher the sensitivity. Even if the inner diameter D of the hole 22A is slightly changed, the detection value of the A / E converter 18 changes greatly. Become like Further, as shown in FIG. 1, the measuring ball 30 is attached to the arm 36 via a support member 32 made of an elastic body (for example, a piano wire or the like). The arm 36 is slidably attached to the gantry 40 via sliders 38, 38, and a feed screw 44 connected to the rotating shaft of the motor 42 is screwed. As a result, when the motor 42 is driven, the feed screw 44 rotates, and the arm 36 moves up and down.

 A linear scale 46 is provided above the arm 36. The linear scale 46 detects the amount of elevation of the arm 36, and outputs a detection signal to the control unit 20. The control unit 20 controls the drive of the motor 4 based on the detection signal, and adjusts the vertical movement of the arm 36, that is, the vertical position of the work 22.

Next, the operation of the measuring device 10 configured as described above will be described. First, compressed air is supplied from the air source 12, and compressed air is injected from the supply port 28 A of the measuring table 18 into the hole 22 A. Next, the motor 42 is driven to lower the arm 36 at a constant speed, the measuring ball 30 is inserted into the hole 22A, and the inserted measuring ball 30 is lowered along the hole 30. Then, the back pressure when the compressed air passes through the gap between the measuring ball 30 and the inner wall of the hole 22A is detected at a plurality of locations (or continuously) at predetermined intervals. Since the back pressure depends on the size of the gap between the measuring ball 30 and the inner wall of the hole 22A, the back pressure detection value is compared with the reference value of the master by the control unit 20 so that the hole 2 is measured. It can be converted to an internal diameter of 2 A. Thus, the inner diameter of the hole 22A can be measured at a plurality of locations, and the shape of the hole 22A can be determined. Here, the reference value of the master cell is a value obtained by measuring the master cell under the same conditions as the measurement prior to the measurement, and is performed every time the measurement conditions are changed.

 An automatic centripetal action (or an automatic centering action) acts on the measuring ball 30 during measurement by compressed air passing through the gap between the inner wall of the hole 22A and the measuring ball 30. Therefore, the supporting member 32 is elastically deformed, and the measuring ball 30 is automatically arranged at the center of the hole 22A. As a result, the compressed air passes through the gap formed substantially uniformly around the work 22. By detecting the back pressure at this time, the outer diameter of the work 12 can be accurately measured. . As described above, according to the measuring apparatus 10 of the present embodiment, the back pressure is measured at a plurality of points while moving the measuring ball 30 along the hole 22 A, so that the inner diameter of the hole 22 A is It can be obtained at a plurality of locations at predetermined intervals in the depth direction of 2 A. Therefore, the shape of the hole 22A can be obtained, and the shape of the hole 22A having a different diameter can also be obtained. For example, if the hole 22A has a taper, the angle of the taper can be determined. Further, as shown in FIG. 7, even when the hole 22A has a reduced diameter portion and an increased diameter portion, the shape of the reduced diameter portion and the increased diameter portion can be obtained. Further, the measuring device 10 can also inspect whether the diameter of the hole 22A is constant.

In the above-described embodiment, the arm 36 is moved down at a constant speed. However, the arm 36 may not be moved at a constant speed. In that case, the position of the measuring ball 30 is detected by the linear scale 46 at the same time as the back pressure is detected by the A / E converter 18. As a result, the measurement of the inner diameter of the hole 22 A and the recording of the measurement position can be performed simultaneously. Therefore, the hole 2 2 A The shape can be determined.

 Further, in the above-described embodiment, the back pressure of the compressed air is detected. However, the present invention is not limited to this. When the compressed air passes through the gap between the inner wall of the hole 22A and the measuring ball 30, The flow rate of the compressed air may be detected. Also in this case, similarly to the above-described embodiment, the control unit 20 can accurately measure the inner diameter of the hole 22A by comparing the detected value with the master reference value.

 Further, the present invention is not limited to the detection of the back pressure and the flow rate of the compressed air, but detects the reaction force received by the measuring ball 30 with a piezoelectric pickup or a strain gauge and converts it into the inner diameter of the hole 22A. FIG. 3 is a block diagram showing the structure of the measuring device 50 of the first embodiment, and FIG. 4 is a side view showing a coupling mechanism between the arm 36 and the support member 32. The measuring device 50 shown in these figures is a device for measuring the center line of the hole 22A.

 In the measuring device 50, a disk 52 is attached to the upper end of the support member 32, and the disk 52 is connected to the arm 36 via four piezoelectric sensors 54, 54,. As shown in FIG. 5, the support member 32 is connected to the center of the disk 52, and the piezoelectric sensors 54, 54,... Are arranged at predetermined intervals around the disk 52. Each piezoelectric sensor 54 detects the resistance received by the measuring ball 30 by dividing it in four directions, and outputs the detection signal to the control unit 20. When receiving the detection signal from each piezoelectric sensor 54, the control unit 20 calculates a rotational moment from the difference between the detection values. Then, the position of the measuring ball 30 is obtained from the rotational moment and the amount of elevation of the arm 36 detected by the linear scale 46.

The measuring device 50 configured as described above inserts the measuring ball 30 into the hole 22A to which the compressed air is supplied, and moves the measuring ball 30 in the depth direction of the hole 22A. The 30 positions are detected at a plurality of positions (or continuously) at predetermined intervals. The measuring ball 30 at the time of measurement is automatically moved to the center of the hole 22A by the automatic centering action as described above. Therefore, when the measuring ball 30 is lowered along the hole 22A, the locus of the center of the measuring ball 30 coincides with the center line of the hole 22A. For example, as shown in FIG. 6, when the hole 22A is formed to be curved, the measuring ball 30 moves along the center line of the hole 22A indicated by a dashed line. I do. Therefore, the center line of the hole 22A can be obtained by calculating the rotational moment from the detected values of the piezoelectric sensors 38, 38,... And obtaining the locus of the center position of the measuring ball 30. Thereby, the curvature and the like of the hole 22A can be measured. Similarly, when the hole 22A is bent, the bending angle can be obtained, and when the hole 22A is formed obliquely, the angle of the hole 22A can be obtained. it can.

 As described above, according to the measuring device 50, the center of the hole 22A is detected by detecting the measuring ball 30 at a plurality of positions with the piezoelectric sensors 54, 54, while moving along the hole 22A. The position can be measured at multiple locations, and the center line of the hole 22A can be determined.

 By the way, the measuring device 50 can calculate the total resistance received by the measuring ball 30 by adding the detection values of the piezoelectric sensors 54, 54,. Therefore, by comparing this calculated value with the reference value of the master, the inner diameter of the hole 22A can be obtained as in the first embodiment. For example, as shown in FIG. 7, when the hole 22A has a reduced diameter portion and an enlarged diameter portion, the shape of the reduced diameter portion and the expanded diameter portion is obtained by obtaining the inner diameter of the hole 22A at a plurality of locations. You can also.

 Further, in the measuring device 50, the center position of the measuring ball 30 and the inner diameter of the hole 22A can be simultaneously determined from the detection values of the piezoelectric sensors 54, 54,. Therefore, even when the hole 22A has a complicated shape (that is, when the center line of the hole 22A is non-linear and not a constant diameter), the shape can be obtained. For example, when the hole 22A is formed as shown in Fig. 8, if the measuring ball 30 is moved in the depth direction of the hole 22A, the measuring ball 30 is moved to the hole 22A indicated by a dashed line. Moving along the center line p From the detection values of the piezoelectric sensors 54, 54, ... at this time, the drag and rotational moment received by the measuring ball 30 are calculated, so that the inner diameter and the center position of the hole 22A are determined. I get it. By calculating the inner diameter and the center position of the hole 22A at a plurality of locations, the shape of the hole 22A can be specifically acquired. As described above, since the measuring device 50 can determine the center position and the inner diameter of the hole 22A at a plurality of positions, it is possible to obtain various hole shapes.

In the embodiment described above, four piezoelectric sensors 54, 54,... Are provided in order to obtain the rotational moment, but three or more piezoelectric sensors 54 may be used. Also, piezoelectric sensors A load cell may be used instead of 54.

 FIG. 9 is a block diagram showing the structure of the measuring device 62 according to the third embodiment.

 In the measuring device 62 shown in the figure, the disk 5 at the upper end of the support member 32 is attached to the X-axis Y-axis stage 64 via three or more piezoelectric elements (not shown). The axis stage 64 is attached to the arm 36. The X-axis and Y-axis stages 64 support the disk 52 slidably in the horizontal direction, and detect the position of the disk 52 by a built-in sensor (not shown).

 The measuring device 62 configured as described above adjusts the position of the disk 52 with the X-axis and Y-axis stages 64 until the detected values of the respective piezoelectric elements become equal. Thereby, the drag received by the measuring ball 30 coincides with the axial direction of the hole 22A. Therefore, by detecting the position of the disk 52 by a sensor built in the X-axis and Y-axis stages 64, the center position of the measuring ball 30 can be obtained. Thus, the center line of the hole 22A can be obtained.

 In the above-described third embodiment, the support member 32 may be formed of a rigid body, and the support member 32 may be directly connected to the X-axis Y-axis stage 64. In this case, since the upper end position of the support member 32 changes according to the position of the measuring ball 30, the position of the measuring ball 30 can be detected by a sensor built in the X-axis Y-axis stage 64.

Further, as shown in FIG. 10, the support member 32 may be attached to the arm 36 using a floating mechanism. The support member 32 shown in FIG. 10 is made of a rigid body, and is attached to a disk 52 at the upper end of the support member 32. The disk 52 is slidably supported in a horizontal direction by a hydrostatic bearing 58. As shown in FIG. 11, the hydrostatic bearing 58 is provided with position detection sensors 60 and 60 such as an optical encoder and a magnetic scale, and the position detection sensor 60 allows the position of the disk 52 to be determined. That is, the position of the measuring ball 30 on the horizontal plane is detected. The position of the measuring ball 30 is calculated based on the horizontal position of the measuring ball 30 detected by the position detection sensor 60 and the vertical position of the measuring ball 30 detected by the linear scale 46. You. Thereby, when the measuring ball 30 is passed through the hole 22A, the locus of the center position of the measuring ball 30 can be obtained, and the center line of the hole 22A can be obtained. In the first, third and third embodiments described above, the measuring ball 30 is moved against the flow of the compressed air. However, the present invention is not limited to this, and the measuring ball 30 is moved in the direction in which the compressed air flows. May be measured while moving.

 The fluid supplied to the hole 22A is not limited to the compressed air, and a gas or liquid other than air may be supplied to the hole 22A.

 Further, a temperature control means for controlling the temperature of the fluid supplied to the hole 22A may be provided. Industrial applicability

 As described above, according to the method and apparatus for measuring the shape of a hole according to the present invention, the float is moved along the depth direction of the hole to which the fluid is supplied, and the position of the float and the inner diameter of the hole are detected at a plurality of locations. Therefore, various hole shapes can be measured.

Claims

The scope of the claims  1. A hole shape measuring method for measuring the inner diameter of a hole at a plurality of locations along the depth direction of the hole to obtain the shape of the hole,  Supplying fluid to the hole,  Insert a float into the hole,  While moving the float along the depth direction of the hole, at least one of a back pressure, a flow rate, and a drag received by the float when the fluid passes through the gap between the inner wall of the hole and the float. Is detected in multiple places,  A method for measuring the shape of a hole, characterized in that the detected value is compared with a reference value and converted into an inner diameter of the hole.  2. A hole shape measuring device for measuring the inner diameter of a hole at a plurality of locations along the depth direction of the hole to obtain the shape of the hole,  Fluid supply means for supplying a fluid to the hole,  A float inserted into the hole,  Moving means for moving the float along the depth direction of the hole;  Detecting means for detecting at least one of a back pressure, a flow rate, and a drag received by the float at a plurality of locations when the fluid passes through a gap between the inner wall of the hole and the float;  Conversion means for comparing the detection value detected by the detection means with a reference value and converting the detected value into the inner diameter of the hole;  A hole shape measuring device comprising:  3. The hole shape according to claim 2, wherein the float is supported by an elastic body. 4. A hole shape measuring method for obtaining a hole shape by measuring a center line of the hole, comprising supplying a fluid to the hole,  Insert a float into the hole, While moving the float along the depth direction of the hole, the position of the float is detected at a plurality of locations, Find the center line of the hole from the detected value,  A hole shape measuring method, wherein the shape of the hole is obtained based on the center line. 5. A hole shape measuring device for measuring the center line of the hole to obtain the shape of the hole, comprising: a fluid supply unit for supplying a fluid to the hole;  A float inserted into the hole,  Moving means for moving the float along the depth direction of the hole;  Position detecting means for detecting the position of the float at a plurality of locations,  A hole shape measuring device comprising:  6. The hole shape measuring device according to claim 5, wherein the float is supported by an elastic body.  7. The hole shape measuring apparatus according to claim 5, wherein the position detecting means divides and detects an anti-force received by the float in three or more directions.  8. The shape of the hole according to claim 7, wherein the float is supported by an elastic body. 9. A hole shape measuring method for measuring the inner diameter of a hole at a plurality of locations along the depth direction of the hole, measuring the center line of the hole, and acquiring the shape of the hole,  Supplying fluid to the hole,  Insert a float into the hole,  While moving the float along the depth direction of the hole, at least one of a back pressure, a flow rate, and a drag received by the float when the fluid passes through the gap between the inner wall of the hole and the float. , Detecting the position of the float and at a plurality of locations,  The back pressure, the flow rate, and the at least one detected value of the drag received by the float are compared with a reference value and converted into an inner diameter of the hole,  Determine the center line of the hole from the detected value of the position of the float,  A hole shape measurement method characterized by acquiring a shape of the hole based on a center line of the hole and an inner diameter of the hole. 10. Measure the inner diameter of the hole at multiple locations along the depth direction of the hole, and A hole shape measuring device for measuring a center line of the hole to obtain a shape of the hole, a fluid supply means for supplying a fluid to the hole,  A float inserted into the hole,  Moving means for moving the float along the depth direction of the hole;  Detecting means for detecting at least one of a back pressure, a flow rate, and a drag received by the float at a plurality of locations when the fluid passes through a gap between the inner wall of the hole and the float;  Conversion means for comparing the detection value detected by the detection means with a reference value and converting the detected value into the inner diameter of the hole;  Position detecting means for detecting the position of the float at a plurality of locations,  A hole shape measuring device comprising:  11. The hole shape measuring apparatus according to claim 10, wherein the float is supported by an elastic body.  12. The hole shape measuring apparatus according to claim 10, wherein the position detecting means detects the resistance received by the float in three or more directions.  13. The hole shape measuring apparatus according to claim 12, wherein the float is supported by an elastic body.