JP7490605B2 - Measuring method, inner diameter measuring instrument, and inner diameter measuring device - Google Patents

Description

The present invention relates to a measurement method, an inner diameter measuring instrument, and an inner diameter measuring device.

2. Description of the Related Art Inner diameter measuring devices are known that measure the inner diameter of a hole formed in a measurement object.
For example, Patent Document 1 discloses an inner diameter measuring device that comprises a main body, a movable axis, a tapered cone, a variable guide, and a measuring probe, and that is capable of measuring the inner diameter of a hole by inserting the variable guide into the hole and bringing the measuring probe into contact with the inner wall of the hole, and in which the tip of the variable guide rotates in a direction approaching or moving away from the movable axis as the movable axis moves back and forth, and that is rotatably supported by the variable guide and comprises a ball bearing that contacts the outer peripheral surface of the tapered cone.

JP 2010-19706 A

Here, when measuring the inner diameter of the hole to be measured, if the probe is inserted and removed while in contact with the inner wall of the hole, the resistance generated during insertion and removal may damage the inner wall or wear out the contact, which is not desirable.
An object of the present invention is to provide a measurement method, an inner diameter measuring instrument, and an inner diameter measuring device that are capable of reducing the resistance when a contact is inserted into or removed from a hole whose inner diameter is to be measured.

The invention described in claim 1 is a measurement method for measuring the inner diameter of a target hole based on the amount of movement of a moving axis corresponding to the position of a contactor that can contact the inner wall of the target hole, which is the hole to be measured, characterized in that when a tip portion having the contactor is inserted into the target hole to measure the inner diameter, the contactor is protruded from the tip portion by pressure from a contact-type displacement meter that indicates a value for determining the inner diameter of the target hole depending on the amount of movement of the moving axis, and when the tip portion is inserted or removed from the target hole, the transmission of pressure from the contact-type displacement meter to the contactor via the moving axis is restricted to bury the contactor within the tip portion.
The invention recited in claim 2 is the measuring method recited in claim 1, characterized in that the restriction of the pressure transmission is performed by blocking a pressure transmission path between the moving shaft and the contact.
The invention described in claim 3 is the measurement method described in claim 2, characterized in that the pressure transmission path is disconnected and connected by moving the moving axis, and the moving speed of the moving axis in the case of connection is slower than the moving speed of the moving axis in the case of disconnection.
The invention described in claim 4 is the measurement method described in claim 2, characterized in that the pressure transmission path is disconnected and connected by moving the moving axis, and the moving speed of the moving axis in the case of the connection is the same as the moving speed of the moving axis in the case of the disconnection.
The invention described in claim 5 is an inner diameter measuring instrument characterized by comprising a tip portion that enters the hole to be measured, which is the hole to be measured, a contactor that is protrudable from the tip portion and contacts the inner wall of the hole to be measured when measuring the inner diameter of the hole to be measured, a moving axis that can be moved toward and away from the contactor and moves in a direction intersecting the direction in which the contactor protrudes, a contact type displacement meter that indicates a value for determining the inner diameter of the hole to be measured depending on the amount of movement of the moving axis, and a contactor burying means for burying the contactor in the tip portion by limiting the transmission of pressure from the contactor to the contactor via the moving axis.
The invention described in claim 6 is an inner diameter measuring instrument as described in claim 5, characterized in that the contact embedding means limits the pressure transmission by blocking the pressure transmission path between the moving axis and the contact.
The invention described in claim 7 is an internal diameter measuring instrument as described in claim 6, characterized in that the contact embedding means includes an actuator that moves the moving axis so that the pressure transmission path is formed, and a spring member that urges the moving axis in a direction opposite to the direction in which the moving axis moves by the actuator, and by stopping the operation of the actuator, the pressure transmission path is blocked by the urging force of the spring member.
The invention described in claim 8 is an inner diameter measuring instrument as described in claim 6, characterized in that the contact embedding means includes an actuator that moves the moving axis so that the pressure transmission path is blocked and moves the moving axis so that the pressure transmission path is formed.
The invention described in claim 9 is the inner diameter measuring instrument described in claim 6, characterized in that the contact embedding means includes a first actuator that moves the moving axis so that the pressure transmission path is blocked, and the inner diameter measuring instrument further includes a second actuator that moves the moving axis so that the pressure transmission path is formed.
The invention described in claim 10 is an inner diameter measuring instrument as described in claim 5, further comprising a control means for controlling at least one of the speed at which the contactor burying means moves the moving axis away from the contactor and the speed at which the moving axis contacts the contactor to make one different from the other, and the speed at which the contact is made is slower than the speed at which the moving axis is moved away.
The invention described in claim 11 is an inner diameter measuring device characterized by having an inner diameter measuring instrument described in claims 5 to 10, and an operating means for switching between embedding the contactor and protruding the contactor using the contactor embedding means.

The present invention makes it possible to reduce the resistance when inserting and removing a contact into a hole whose inner diameter is to be measured.

FIG. 1 is a diagram showing an example of an inner diameter measuring instrument to which the present embodiment is applied. FIG. 2 is a diagram illustrating the configuration of an inner diameter measuring gauge. FIG. 2 is a perspective view illustrating the appearance of an inner diameter measuring gauge. 5A and 5B are diagrams for explaining the positional relationship with respect to the tip of the contact, in which (a) shows a state in which no external force is being applied from the needle to the contact holder, and (b) shows a state in which an external force is being applied. FIG. 1 is a diagram showing an example of a contact type displacement meter. 1A to 1E are diagrams for explaining the state in which the tip of an inner diameter measuring gauge has entered the measurement target hole of a machined part, and each of (a) to (e) shows a different state of the tip. 1A and 1B are diagrams explaining the contact and separation between the contact displacement gauge and the needle of the inner diameter measuring gauge due to the operation of the contact displacement gauge, in which (a) shows a state in which the probe of the contact displacement gauge is separated from the needle of the inner diameter measuring gauge, and (b) shows a state in which the probe is in contact with the needle of the inner diameter measuring gauge. 10A and 10B are diagrams illustrating modified examples of the driving manner of the needle, in which FIG. 10A shows a buried state of the contact, and FIG. 10B shows a protruding state of the contact. 10 is a flowchart illustrating an example of a processing procedure in a manual measuring machine.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[Explanation of Inner Diameter Measuring Instrument 1]
FIG. 1 is a diagram showing an example of an inner diameter measuring instrument 1 to which the present embodiment is applied.
The inner diameter measuring instrument 1 is used to measure the inner diameter of a hole formed in a machined part, for example, in a parts manufacturing factory. Note that the inner diameter measuring instrument 1 is used for comparative measurement to obtain the inner diameter by comparing with a reference length such as a master gauge (not shown), but is not limited to this, and may be a measuring instrument that indicates a length value without comparing with a reference length.

The inner diameter measuring instrument 1 according to this embodiment includes a plug gauge or inner diameter measuring gauge 11 that converts the amount of movement in the hole diameter direction of the contact 3 (described below) that contacts the inner wall of the hole to be measured, which is the hole to be measured, into the amount of movement in the depth direction or axial direction of the hole to be measured, a contact type displacement meter 12 that indicates a value for identifying the inner diameter of the hole to be measured according to the amount of axial movement of the inner diameter measuring gauge 11, a mounting holder 13 for mounting the inner diameter measuring gauge 11 and the contact type displacement meter 12 while maintaining their positional relationship, and a mounting adapter 14 for mounting the inner diameter measuring gauge 11 to the mounting holder 13.

[Explanation of inner diameter measuring gauge 11]
FIG. 2 is a diagram for explaining the configuration of the inner diameter measuring gauge 11, showing a cross section of the assembled components and illustrating the shapes of each component.
2, the inner diameter measuring gauge 11 comprises, as its components, a hollow rod-shaped main body 2 that enters the hole to be measured, and a contact 3 that is provided on the main body 2 and protrudes from the outer circumferential surface so as to be able to contact the inner wall of the hole to be measured. The inner diameter measuring gauge 11 also comprises, as its components, a cylindrical contact holder 4 that is provided inside the main body 2 and holds the contact 3, a needle 5 that is provided axially movable within the cylinder of the contact holder 4, and a lid 6 that is attached to the main body 2 and covers the needle 5.

The main body 2 has a tip 21 formed with an outer shape corresponding to the shape of the hole to be measured. The tip 21 is the part that enters the hole to be measured when measuring the inner diameter. The tip 21 also has an opening 22 that allows the contact 3 to protrude from the outer circumferential surface.

The contacts 3 are configured to include a spherical portion 31 that protrudes from the outer circumferential surface of the tip portion 21, and a base portion 32 that holds the spherical portion 31 and is formed in a stepped shape with a smaller diameter at the portion farther from the spherical portion 31 than at the portion closer to the spherical portion 32. The contacts 3 are arranged in a pair so that they can move in the radial direction of the tip portion 21. That is, in a pair of contacts 3, when one contact 3 and the other contact 3 move in a direction away from each other, both contacts 3 protrude from the outer circumferential surface of the tip portion 21, and when they move toward each other, they retract and become embedded in the outer circumferential surface. The state of the contacts 3 shown in Figure 2 is embedded.

The contact holder 4 has a pair of base holding parts 41 at one end in the axial direction, which separately hold a pair of contacts 3. More specifically, the base holding parts 41 have a stepped hole shape that engages with the base 32, and the contacts 3 are attached to the base holding parts 41 by being inserted into the holes from the outer peripheral surface side. Note that in this embodiment, the contacts 3 and the contact holder 4 have corresponding stepped shapes, but this is not limited to this and shapes other than stepped shapes may also be used, and well-known and commonly used techniques can be used as a means for attaching the contacts 3 to the contact holder 4.
The contact holder 4 also has split portions 43 that are divided into two by a slit 42 that is formed from a middle position to one end and penetrates in the radial direction. The split portions 43 are elastic and are allowed to deform in directions away from each other due to an external force, while being biased in directions toward each other against the external force. An internal space with a diameter dimension larger than the outer diameter of the contact holder 4 is formed in an area of the main body 2 that corresponds to the split portion 43 of the contact holder 4. This configuration allows the base holding portion 41 to move in the radial direction, making it possible for the contact holder 4 to move the contacts 3 in the approaching and separating directions.

The needle 5 has a tapered portion 51 at one end. When the needle 5 moves in the axial direction, the tapered portion 51 can come into contact with the base holding portion 41 of the contact holder 4. Such contact increases the distance between the base holding portions 41. As a result, the pair of contacts 3 move in directions away from each other, and come into a protruding state in which they protrude from the outer circumferential surface of the main body 2.
When the tapered portion 51 separates from the base holding portion 41, the elasticity of the contact holder 4 causes the distance between the base holding portions 41 to return to the original distance. That is, the pair of contacts 3 move in a direction approaching each other, and enter a buried state in which they are buried in the outer circumferential surface of the main body 2.

The lid portion 6 partially holds the needle 5 and exposes the end portion 52 of the needle 5 opposite the tapered portion 51 to the outside. This allows the axial movement of the needle 5 to be unhindered and allows the end portion 52 of the needle 5 to move outside the inner diameter measuring gauge 11.

FIG. 3 is a perspective view illustrating the appearance of the inner diameter measuring gauge 11. As shown in FIG.
3, the inner diameter measuring gauge 11 has a circular and elongated outer shape, and an end 52 of the needle 5 protrudes from the cover 6. In addition, an opening 22 is formed in the tip 21 of the main body 2 to allow the contact 3 held in the contact holder 4 to protrude from the main body 2.
The main body 2 also has a flat surface 23 that is used for mounting the mounting adaptor 14 (see FIG. 1).

Here, in the inner diameter measuring gauge 11, the contact 3 is an example of a contact piece, the needle 5 is an example of a moving shaft, and the tip portion 21 is an example of a tip portion.
Furthermore, when the probe 114 (see FIG. 5) of the contact type displacement gauge 12 comes into contact with the needle 5 of the inner diameter measuring gauge 11, pressure from the probe 114 is transmitted to the needle 5. Then, the pressure is transmitted from the contact holder 4 to the contact 3 via the tapered portion 51 of the needle 5. Such a transmission path is an example of a pressure transmission path.
Moreover, the contact type displacement meter 12 (see FIG. 1 or FIG. 5), the details of which will be described later, is an example of the contact type displacement meter.

As described above, the needle 5 is movable in the axial direction, and is capable of approaching and separating from the contact holder 4, and of changing the contact state. When the needle 5 comes into contact with the contact holder 4 and an external force is applied thereto, the divided portion 43 is deformed, and the contact 3 moves, and the positional relationship of the contact 3 with respect to the tip portion 21 is changed.
4A and 4B are diagrams for explaining the positional relationship with respect to the tip portion 21 of the contact 3, in which (a) shows a state in which no external force is being applied from the needle 5 to the contact holder 4, and (b) shows a state in which an external force is being applied.
4A, even if the tapered portion 51 of the needle 5 is in contact with the contact holder 4, the divided portion 43 of the contact holder 4 does not deform unless an external force is applied from the needle 5 to the contact holder 4. The pair of contacts 3 held by the base holding portion 41 of the contact holder 4 does not move and is embedded in the tip portion 21.
When the needle 5 is separated from the contact holder 4, the pair of contacts 3 is in the same state as shown in FIG.

4B, when the needle 5 moves toward the contact holder 4 and the tapered portion 51 enters between the divided portions 43 of the contact holder 4, the divided portions 43 are elastically deformed. Due to this elastic deformation, the pair of contacts 3 move in directions away from each other, and the amount of dimension δ protrudes from the tip portions 21.
When the needle 5 moves in a direction away from the contact holder 4, the divided portion 43 tries to return to its original state due to its own elasticity. In addition, when the needle 5 moves away from the contact holder 4, the state shown in FIG.

The amount of axial movement of the needle 5 and the amount of movement of the pair of contacts 3 have a relative relationship according to the angle of the tapered portion 51 of the needle 5. In other words, by detecting the amount of movement of the needle 5, the amount of movement of the contacts 3 can be obtained.
The amount of movement of the needle 5 is measured by the above-mentioned contact type displacement meter 12 and converted into the amount of movement of the contact 3 .

[Explanation of contact type displacement gauge 12]
FIG. 5 is a diagram showing an example of the contact type displacement meter 12. As shown in FIG.
The contact type displacement meter 12 has a length measuring device 101 for detecting the length of the object to be measured based on the displacement of the moving part 110, a display device 102 as a controller connected to the length measuring device 101 and performing various calculations, measuring dimensions, judging the pass/fail of the finish of the workpiece during processing, and displaying the results, and a cable 103 that electrically connects the length measuring device 101 and the display device 102. Furthermore, the contact type displacement meter 12 has an air supplier 104 that supplies air to the length measuring device 101 for pressing the moving part 110 against the object to be measured, and an air tube 105 that connects the length measuring device 101 and the air supplier 104 to enable air circulation.
The contact type displacement meter 12 is for comparative measurement to indicate the amount of displacement of the needle 5, but may also indicate the inner diameter itself.

The length measuring device 101 brings the measuring probe 114 of the moving part 110, which is movable in the axial direction relative to the housing part 150, into contact with the object to be measured. The length measuring device 101 then optically detects the displacement of the moving part 110 from the reference position.

The display 102 allows the user to set the initial parameters used when measuring with the length measuring device 101 and to register various parameters. In addition, the display 102 allows the user to register the setting conditions by SET NO. (set number), and to easily call up the measurement conditions by specifying the SET NO. This makes it easy to change the setup. In addition, the measurement screen of the display 102 also allows the user to perform a reset operation for master alignment. As the display by the display 102, for example, as an absolute value display, for example, the state where the moving part 110 of the length measuring device 101 is most extended can be set to almost zero, and a mechanically unique measurement value can be displayed. In addition, the display 102 has a pass/fail judgment function that judges whether the measurement value is within the set pass/fail judgment/rank judgment range and displays and outputs the result.

The display 102 can be configured to link a plurality of length measuring devices 101, and can perform multi-point calculation display. The display 102 can also be provided with various interfaces for external input/output, and can be used according to the purpose.
As for the configuration of the display 102, the length measuring device 101 may have the same functions inside. Also, it is possible to communicate with the display 102 using various wireless communication functions without using the cable 103.

The cable 103 is provided with a connector that can be detached from the connector provided at the rear end of the length measuring device 101 in a male/female relationship.

The air supplier 104 is controlled by a control unit (not shown). The air supplier 104 supplies air to the length measuring device 101 through an air tube 105, thereby advancing the moving part 110 from the housing part 150. The air supplier 104 also controls an electromagnetic valve to release the air supplied to the length measuring device 101 to the atmosphere, thereby drawing the moving part 110 into the housing part 150.
In this embodiment, the length measuring device 101 can change the pressing force of the probe 114 against the measurement object and the moving speed of the probe 114 according to the air supply conditions by the air supplier 104 .

One end of the air tube 105 is connected to the air inlet/outlet of the air supplier 104, and the other end is connected to a connection portion provided on the rear end side of the length measuring device 101. The air tube 105 forms an air path between the air supplier 104 and the length measuring device 101. In this embodiment, the air tube 105 is provided with a supply path 106 that supplies air to the length measuring device 101, and an open path 107 that releases the air supplied to the length measuring device 101 to the atmosphere. A configuration may be adopted in which the air tube 105 supplies air without being divided into the supply path 106 and the open path 107, and the air is released from a different location.

Here, in the contact displacement meter 12, the displacement of the moving part 110 is measured by the measuring part. The measuring part has a light-emitting element that irradiates light, and a light-receiving element that receives the light irradiated by the light-emitting element. An LED or the like can be used as the light-emitting element. The light-receiving element has a sensor IC such as a photodiode or image sensor, and reads the transmitted light that has passed through the glass scale, and detects the information of the scale of the glass scale obtained based on the change in the amount of light from the light-emitting element. The measurement result based on the detected information is displayed on the display 102.

In the contact type displacement meter 12, the moving part 110 is biased by a compression coil spring in a direction in which it is pulled into the housing part 150 (towards the rear end side). The contact type displacement meter 12 according to the present embodiment is a single-acting push-out air cylinder.
When air is supplied from the air supplier 104 to the internal space of the housing 150, the air in the internal space reaches a predetermined pressure, and a force acts on the moving part 110 to move it toward the tip end against the spring force of the compression coil spring. Also, when the supply of air to the internal space is stopped, the moving part 110 moves toward the rear end due to the spring force of the compression coil spring.
By adjusting the air supply, the position or amount of movement of the moving part 110 relative to the housing part 150 can be controlled.

The contact displacement meter 12 is driven by the measuring instrument itself, so by using the contact displacement meter 12, the structure of the inner diameter measuring instrument 1 can be simplified. For example, it is possible to move the measuring instrument up and down using an external mechanism, but this would complicate the structure and would be a factor affecting measurement accuracy due to repeated positioning. By including the contact displacement meter 12 in the inner diameter measuring instrument 1, such concerns are eliminated.

[Relationship between tip 21 and measurement target hole 10a]
Figure 6 is a diagram explaining the state in which the tip 21 of the inner diameter measuring gauge 11 has entered the measurement target hole 10a of the machined part 10, and each of (a) to (e) shows a different state of the tip 21.
6(a), the needle 5 is located away from the contact holder 4, and the tapered portion 51 is not in contact with the contact holder 4. The pair of contacts 3 held by the contact holder 4 do not protrude from the opening 22 of the main body 2, but are completely recessed and embedded in the tip portion 21. The distance between the outer circumferential surface of the tip portion 21 and the contacts 3 is dimension δ1.

In the state shown in FIG. 6(b), the taper portion 51 of the needle 5 is in contact with the contact holder 4, but the needle 5 exerts almost no pressure on the contact holder 4 and is completely retracted. The pair of contacts 3 are buried, as in FIG. 6(a), and the distance between the outer circumferential surface of the tip portion 21 and the contacts 3 is dimension δ1' (δ1'≦δ1).

In the state shown in FIG. 6(c), the needle 5 advances more toward the contacts 3 than in FIG. 6(b), and the pressure from the needle 5 to the contact holder 4 becomes higher. More specifically, although pressure from the tapered portion 51 of the needle 5 acts on the contact holder 4, the pair of contacts 3 are buried and do not protrude from the outer circumferential surface of the tip 21, and are not in contact with the inner wall 10b of the measurement target hole 10a. The distance between the outer circumferential surface of the tip 21 and the contacts 3 is dimension δ2, which is smaller than dimension δ1 (δ2<δ1'≦δ1).

In the state shown in FIG. 6(d), the needle 5 advances further toward the contact 3 than in FIG. 6(c), so the pressure from the tapered portion 51 of the needle 5 to the contact holder 4 is even higher than in FIG. 6(c). The pair of contacts 3 have moved to the position of the outer circumferential surface of the tip portion 21. If the contacts 3 in the state shown in FIG. 6(d) were measured, the dimensions would be almost the same as the outer diameter of the tip portion 21. In other words, they are neither buried nor protruding, but are flush.

In the state shown in Fig. 6(e), the needle 5 advances further toward the contacts 3 than in the case of Fig. 6(d), and the pressure from the contact holder 4 is higher than in the case of Fig. 6(d). In the state shown in Fig. 6(e), the pair of contacts 3 protrude from the outer circumferential surface of the tip portion 21. The amount of contacts 3 protruding from the outer circumferential surface of the tip portion 21 is dimension δ3, which is smaller than dimension δ4, which is the radial difference between the outer circumferential surface of the tip portion 21 and the inner wall 10b of the measurement target hole 10a (δ3<δ4).
In addition, when measuring the inner diameter, the needle 5 is advanced toward the contact 3 until the contact 3 comes into contact with the inner wall 10b. When the needle 5 is advanced toward the contact 3 and comes into contact with the inner wall 10b, the needle 5 will no longer advance even when pressure is applied, and the inner diameter of the measurement target hole 10a is calculated based on the measurement result in this state.

The state shown in FIG. 6(e) is one in which pressure from the contact displacement meter 12 is transmitted from the needle 5 to the contact holder 4, causing the contact 3 held by the contact holder 4 to protrude from the outer circumferential surface of the tip 21. In other words, the state shown in FIG. 6(e) is one in which the pressure from the contact displacement meter 12 causes the contact 3 to protrude from the tip 21.

6(a) to 6(c) of (a) to 6(e), the pair of contacts 3 are buried in the tip portion 21. That is, (a) to (c) of the same figure show a state in which pressure transmission from the contact type displacement meter 12 to the contacts 3 via the needle 5 is restricted, and the contacts 3 are buried in the tip portion 21.
Therefore, when the tip 21 of the inner diameter measuring gauge 11 is inserted or removed from the measurement target hole 10a of the machined part 10, if it is in any of the states shown in (a) to (c) in the same figure, it is possible to prevent the pair of contacts 3 from coming into contact with the inner wall 10b of the measurement target hole 10a, thereby preventing damage to the inner wall 10b or wear of the contacts 3.

6(d), the pair of contacts 3 do not protrude from the outer circumferential surface of the tip portion 21. That is, FIG. 6(d) shows a state in which pressure transmission from the contact-type displacement meter 12 to the contacts 3 via the needle 5 is restricted so that the contacts 3 do not protrude from the tip portion 21.
Therefore, when inserting or removing the tip portion 21 into or from the measurement target hole 10a, even in the state shown in Figure 6 (d), contact between the contact 3 and the inner wall 10b can be prevented, thereby preventing damage to the inner wall 10b and wear on the contact 3.

To explain further, in FIG. 6(e), a pair of contacts 3 protrude from the tip 21, but there is a gap between them and the inner wall 10b (=(δ4-δ3)/2), and they are not in contact with the inner wall 10b. Therefore, it is possible to insert and remove the tip 21 into the measurement target hole 10a without the contact 3 coming into contact with the inner wall 10b of the measurement target hole 10a. Therefore, when the relative positional relationship between the tip 21 and the machined part 10 is positioned with high precision, even if the contact 3 protrudes from the tip 21, the contact 3 does not come into contact with the inner wall 10b when the tip 21 is inserted or removed from the measurement target hole 10a. Therefore, even in the case of FIG. 6(e), it is possible to reduce the resistance when inserting and removing the tip 21 or the contact 3 into or from the hole whose inner diameter is to be measured.

When inserting and removing the tip portion 21 into and from the measurement target hole 10a, by preventing the contact 3 from protruding further than during measurement, as shown in Figures 6(a) to (e), it is possible to reduce the resistance when inserting and removing the contact 3 into and from the measurement target hole 10a.
In addition, when the inner diameter measuring gauge 11 is inserted and removed, the load on the contact holder 4, which has a thin portion due to its structure, can be reduced, and the measuring force during measurement can be increased.

A preferred mode for preventing the contacts 3 from protruding more than during measurement when inserting and removing the tip portion 21 into and from the measurement target hole 10a is to prevent the contacts 3 from protruding from the outer circumferential surface of the tip portion 21, as shown in Figures 6(a) to 6(d). A more preferred mode for insertion and removal is to have the contacts 3 retract from the outer circumferential surface of the tip portion 21, as shown in Figures 6(a) to 6(c).
Here, in this document, "embedded" refers to a state in which the contact 3 does not protrude from the outer peripheral surface of the tip portion 21, and in this document, "limiting pressure transmission" refers to suppressing the pressure transmitted from the contact displacement meter 12 to the contact 3 via the needle 5 to an extent that the contact 3 does not protrude from the outer peripheral surface of the tip portion 21.

Figure 7 is a diagram explaining the contact and separation of the contact-type displacement meter 12 with the inner diameter measuring gauge 11 due to the operation of the contact-type displacement meter 12, (a) shows a state in which the probe 114 of the contact-type displacement meter 12 is separated from the needle 5 of the inner diameter measuring gauge 11, and (b) shows a state in which they are in contact. The inner diameter measuring instrument 1 shown in Figure 7 is arranged so that the contact-type displacement meter 12 is on the lower side and the inner diameter measuring gauge 11 is on the upper side. In Figure 7, the machined part 10 having the measurement target hole 10a and the measurement table 71 on which the machined part 10 is placed are shown by dashed lines.
Fig. 7(a) shows a state in which the needle 5 is separated from the contact holder 4, and the pressure transmission path between the needle 5 and the contact 3 is interrupted. In other words, when air is not supplied to the contact displacement gauge 12, the moving part 110 is pulled in by the spring force of the compression coil spring, as shown in Fig. 6(a), and the measuring element 114 of the contact displacement gauge 12 separates from the needle 5 of the inner diameter measuring gauge 11. The needle 5 moves downward by its own weight.

On the other hand, when air is supplied to the contact type displacement gauge 12, a pressure transmission path is formed or connected between the needle 5 and the contact 3. That is, as shown in Fig. 7(b), the moving part 110 is pulled out against the spring force of the compression coil spring, and the probe 114 of the contact type displacement gauge 12 comes into contact with the needle 5 of the inner diameter measurement gauge 11. When this supply of air continues, contact between the probe 114 of the contact type displacement gauge 12 and the needle 5 of the inner diameter measurement gauge 11 is maintained.
Furthermore, the amount by which the moving part 110 is pulled out can be set to any value by air control.

[Explanation of connecting and disconnecting the pressure transmission path]
Here, the pressure transmission path is disconnected as shown in Figure 7(a) and connected as shown in the same figure (b), and switching between such disconnection and connection is performed by moving the needle 5 of the inner diameter measuring gauge 11.
The moving speed of the needle 5 when connecting and disconnecting the pressure transmission path depends on the amount of air supplied or discharged by the air supplier 104 in the contact displacement meter 12. That is, if the flow rate of the air supplied or discharged is increased, the moving speed of the needle 5 increases, and if the flow rate is decreased, the moving speed of the needle 5 decreases.

Such speed control is performed by meter-in control, which controls the amount of air supplied by a speed controller, or meter-out control, which controls the amount of air discharged.
It is possible to consider a mode in which the air supply is controlled so that the movement speed of the needle 5 is different when a blocked pressure transmission path is connected and when a connected pressure transmission path is blocked, and a mode in which the air supply speed is controlled so that the movement speed is the same.

Specifically, by adopting control that makes the movement speed of the needle 5 slower when connecting the pressure transmission path than the movement speed of the needle 5 when blocking the pressure transmission path, the impact when the needle 5 comes into contact with the contact holder 4 is reduced, damage to the contact holder 4 can be prevented, and the component life of the contact holder 4 can be extended.
Furthermore, by adopting control that sets the movement speed of the needle 5 when connecting the pressure transmission path to the same as the movement speed of the needle 5 when blocking the pressure transmission path, the pressure transmission path can be connected in a short time, thereby making the measurement process more efficient.
The air supplier 104 is an example of a control means.

As described above, the probe 114 of the contact type displacement gauge 12 comes into contact with the needle 5, thereby transmitting pressure to the contact 3 (see FIG. 7(b)). The probe 114 of the contact type displacement gauge 12 comes into contact with the needle 5 by controlling the air supply from the air supplier 104 in the contact type displacement gauge 12 to start, and moves away from the needle 5 by the spring force of the compression coil spring described above by controlling the air supply to stop. Therefore, the air supplier 104 and the compression coil spring of the contact type displacement gauge 12 are an example of a contact embedding means.

[Needle 5 Drive Mode]
As described above, the needle 5 in this embodiment is driven by a single-acting air cylinder that moves the moving part 110 in one direction by air and in the other direction by a compression coil spring. That is, the direction in which the pressure transmission path is established is performed by the air cylinder, and the direction in which the pressure transmission path is blocked is performed by the compression coil spring.
In other words, a single-acting air cylinder built into the contact displacement gauge 12 serves as an actuator that moves the needle 5 so that a pressure transmission path is formed, and a compression coil spring built into the contact displacement gauge 12 serves as a spring member that biases the needle 5 in a direction in which the pressure transmission path is blocked (the direction opposite to the direction in which the needle 5 is moved by the air cylinder).
The term "actuator" used here refers to a drive device that converts energy such as electricity, air pressure, or hydraulic pressure into mechanical movement to move equipment accurately.

The manner in which the needle 5 is driven is not limited to the above-described embodiment, and various modifications are possible.
(Variation 1)
For example, in the case where the contact type displacement gauge 12 does not incorporate a single-acting air cylinder but incorporates a compression coil spring, a drive mode can be adopted in which a single-acting air cylinder is retrofitted to the outside of the contact type displacement gauge 12. That is, in this drive mode, a retrofitted single-acting air cylinder is used as an actuator that moves the needle 5 so that a pressure transmission path is formed, and the needle 5 is moved in a direction in which the pressure transmission path is blocked by the compression coil spring incorporated in the contact type displacement gauge 12.

As described above, when a drive mode is adopted in which the actuator is used for movement in the direction in which the pressure transmission path is formed, and the compression coil spring is used for movement in the direction in which the pressure transmission path is blocked, the moving part 110 (see FIG. 5 ) is pushed out by the pressure of the actuator which overcomes the pressure of the compression coil spring.
Therefore, since the force (measuring force) required to move the needle 5 and cause the contact 3 to protrude when measuring the inner diameter is the variable pressure generated by the actuator minus the spring force generated by the compression coil spring, the measuring force can be fine-tuned by adjusting the air pressure.
This effect is not achieved in a configuration that does not use an actuator. In other words, in a configuration that does not use an actuator, the measuring force is the spring force of a compression coil spring, making it difficult to fine-tune the measuring force, and in a configuration that does not use an actuator, the measuring force also changes depending on whether the contact 3 is in an upper position or a lower position, resulting in limitations on the mounting position. The above-mentioned driving mode that uses an actuator also achieves the effect of eliminating such limitations.

(Variation 2)
As another driving mode, it is possible to use a compression coil spring for the movement in the direction in which the pressure transmission path is formed, and an actuator for the movement in the direction in which the pressure transmission path is interrupted. In this driving mode, the spring force of the compression coil spring pushes out the moving part 110 (see FIG. 5).
In this case, the measuring force is the spring force of the compression coil spring minus the variable pressure of the actuator, so that the measuring force can be finely adjusted by adjusting the air pressure.
Additionally, the air cylinder as the actuator may be of a vacuum-driven type instead of a compressed air-driven type, in which the pressure of the vacuum air overcomes the compression coil spring to pull back the moving part 110 (see FIG. 5) and cut off the force transmission path.

(Variation 3)
As another driving mode, when the contact displacement gauge 12 is configured to include a double-acting air cylinder instead of a single-acting type, it is not necessary to incorporate a compression coil spring in the contact displacement gauge 12. In other words, the needle 5 may be driven by a double-acting air cylinder that has two ports and realizes reciprocating movement in a direction in which the pressure transmission path is formed and in a direction in which the pressure transmission path is blocked by air by switching between intake and exhaust.

(Variation 4)
In addition, when the contact-type displacement meter 12 is configured to include an electric motor or solenoid (not shown) instead of a single-acting air cylinder, another driving mode can be adopted. For example, the movement in the direction in which the pressure transmission path is formed may be performed by an electric motor or solenoid built into the contact-type displacement meter 12, and the movement in the direction in which the pressure transmission path is cut off may be performed by a compression coil spring built into the contact-type displacement meter 12.

(Variation 5)
Furthermore, in the case where the contact type displacement gauge 12 does not have a built-in compression coil spring, the movement in the direction in which a pressure transmission path is formed and the movement in the direction in which the pressure transmission path is blocked may be performed by an electric motor built into the contact type displacement gauge 12, or may be performed by a solenoid built into the contact type displacement gauge 12.
The above-mentioned air cylinder, electric motor, solenoid, and other actuators are examples of the actuator, and the above-mentioned compression coil spring is an example of the spring member.

(Variation 6)
8A and 8B are diagrams for explaining a sixth modified example regarding the driving mode of the needle 5, in which (a) shows the buried state of the contact 3 and (b) shows the protruding state of the contact 3. In the sixth modified example, as shown in FIG.
The contact-type displacement meter according to the sixth modification incorporates a single-acting air cylinder 81, but does not incorporate a compression coil spring. The air cylinder 81 moves the needle 5 of the inner diameter measurement gauge 11 in a direction in which a pressure transmission path is formed. A double-acting air cylinder 83 disposed outside the contact-type displacement meter 12 moves the needle 5 in a direction in which the pressure transmission path is blocked.

As shown in FIG. 8(a) or (b), in the sixth modification, the contact 3 is switched between recessed and protruding by an internal air cylinder 81 and an external air cylinder 83. That is, the needle 5 is driven in a direction in which a pressure transmission path is formed by the air cylinder 81, and the needle 5 is driven in a direction in which the pressure transmission path is blocked by another air cylinder 83.

More specifically, a release plate 82 extending outside the contact displacement meter 12 is connected to the needle 5. The release plate 82 moves together with the needle 5 by an internal air cylinder 81. Note that, although the release plate 82 is attached to the needle 5 in the sixth modification, this is not limiting, and the release plate 82 may be attached to, for example, the moving part 110 (see FIG. 7) of the contact displacement meter 12.
Further, a release plate 84 capable of coming into contact with the release plate 82 is connected to the external air cylinder 83. The release plate 84 is moved by the external air cylinder 83.

When the needle 5 is moved in a direction in which the pressure transmission path is blocked, the external air cylinder 83 is operated. When the release plate 84 is moved by the external air cylinder 83, as shown in FIG. 8(a), the release plate 84 comes into contact with the release plate 82, and then moves while pushing the release plate 82. This causes the needle 5 to move in a direction in which the pressure transmission path is blocked.

When measuring the inner diameter by moving the needle 5 in the direction in which a pressure transmission path is formed, the external air cylinder 83 is first actuated to move the release plate 84 away from the release plate 82 as shown in FIG. 8(b), and the release plate 84 is then retracted to prevent interference. Next, the built-in air cylinder 81 is actuated to move the release plate 82. This causes the needle 5 to move in the direction in which a pressure transmission path is formed.

The air cylinders 81 and 83 are connected to an operation unit 85 that is operated by the user. The operation unit 85 accepts the user's operation to control the operation of the air cylinders 81 and 83, and switches the contact 3 between recessed and protruding.

Here, the built-in air cylinder 81 is an example of a second actuator, and the external air cylinder 83 is an example of a first actuator. Also, the operation unit 85 is an example of an operation means. The inner diameter measuring instrument 1 to which the modified example 6 is applied is an example of an inner diameter measuring device.
In the case of the above-described embodiment (see FIG. 5), the operation unit 85 operated by the user is connected to the air supplier 104 (see FIG. 5).

[Application of Inner Diameter Measuring Instrument 1]
The above-mentioned inner diameter measuring instrument 1 can be applied to a manual measuring instrument, and can also be applied to an automatic measuring instrument.
Such a manual measuring machine includes an inner diameter measuring instrument 1 (see, for example, Figure 7) mounted with the tip 21 facing upward, a measuring table 71 (see, for example, Figure 7) on which the machined part 10 is placed, an up-down mechanism (not shown) for fine-tuning the measuring height, and a controller (not shown).
The inner diameter measuring instrument 1 is controlled by a controller (not shown).

An example of a processing procedure in a manual measuring device will now be described.
FIG. 9 is a flowchart illustrating an example of a processing procedure in the manual measuring device.
In the example of the processing procedure shown in Fig. 9, first, a pre-processing is performed using a master gauge (step 101). In this pre-processing, the master gauge is set, the air is turned on, the master gauge is measured, the reference zero point is preset, and the tolerance range for the master gauge is set. Then, the air is turned off, and the master gauge is removed.

Then, the machined part 10 is placed on the measuring table 71 (step 102), the tip 21 of the inner diameter measuring gauge 11 is inserted into the measurement target hole 10a of the machined part 10 (step 103), and the air is turned ON (step 104). When the tip 21 is inserted, the air is OFF and the contact 3 is in a buried state, and when the air is turned ON after the entry, the contact 3 becomes in a protruding state and can be measured.

The measured value is read and judged (step 105), and after the air is turned off (step 106), the tip 21 is withdrawn from the measurement target hole 10a (step 107), and the machined part 10 is removed (step 108). Thereafter, steps 102 to 108 are repeated each time another machined part 10 is measured.
When the tip portion 21 is withdrawn, the air is turned off and the contact 3 is in a buried state.

In this way, when the tip 21 is inserted into or removed from the measurement target hole 10a, the pressure transmission path is blocked by turning the air off, thereby burying the contact 3 within the tip 21, thereby preventing the inner wall of the measurement target hole 10a from being damaged or the contact 3 from being worn down due to resistance during insertion and removal.
On the other hand, during measurement, the air is turned on and a pressure transmission path is formed, causing the contact 3 to protrude from the tip portion 21 .

An automatic measuring machine to which the above-mentioned inner diameter measuring instrument 1 is applied is equipped with an inner diameter measuring unit including the inner diameter measuring instrument 1 (for example, FIG. 7).
An example configuration of the automatic measuring machine, although not shown in the figure, includes a transfer station for transferring the machined part 10 having the measurement target hole 10a formed therein from the previous process, a supply hand for supplying the machined part 10 from the transfer station to the measuring table 71, a laser displacement meter for checking whether the machined part 10 is present on the measuring table 71, an inner diameter measurement unit for measuring the machined part 10 on the measuring table 71, a judgment section for determining whether the part is passable or not based on the measurement results by the inner diameter measurement unit, a pass-product storage tray for storing machined parts 10 determined to be passable by the judgment section, and a reject product collection case for collecting machined parts 10 not determined to be passable by the judgment section.
By using an automatic measuring machine, automatic measurement can be achieved while preventing damage to the inner wall of the measurement target hole 10a of the machined part 10 and wear of the contact 3 of the inner diameter measuring instrument 1.

1...inner diameter measuring instrument, 3...contact, 4...contact holder, 5...needle, 10...machined part, 10a...hole to be measured, 10b...inner wall, 11...inner diameter measuring gauge, 12...contact displacement meter, 21...tip, 51...tapered part, 81, 83...air cylinder, 85...operating part, 104...air supplier, 110...moving part

Claims (11)

A method for measuring an inner diameter of a measurement target hole based on a movement amount of a movement axis corresponding to a position of a contact that can contact an inner wall of the measurement target hole, the method comprising:
when the tip having the contact is inserted into the measurement target hole to measure the inside diameter, the contact is protruded from the tip by pressure from a contact type displacement meter which indicates a value for specifying the inside diameter of the measurement target hole according to the amount of movement of the movement axis;
A measurement method characterized in that, when the tip is inserted or removed from the measurement target hole, the transmission of pressure from the contact displacement gauge to the contactor via the moving axis is restricted to bury the contactor within the tip. The measurement method according to claim 1, characterized in that the pressure transmission is restricted by blocking the pressure transmission path between the moving shaft and the contact. The pressure transmission path is disconnected and connected by the movement of the moving shaft,
3. The method according to claim 2, wherein the moving speed of said moving axis in said connection state is slower than the moving speed of said moving axis in said disconnection state. The pressure transmission path is disconnected and connected by the movement of the moving shaft,
3. The method according to claim 2, wherein the moving speed of said moving axis in said connection state is the same as the moving speed of said moving axis in said disconnection state. A tip portion that enters a measurement target hole that is a measurement target hole;
a contact provided on the tip portion so as to be capable of protruding and adapted to come into contact with an inner wall of the measurement target hole when measuring the inner diameter of the measurement target hole;
a moving axis that is capable of approaching and separating from the contact and moves in a direction intersecting a direction in which the contact protrudes;
a contact type displacement meter that indicates a value for identifying the inner diameter of the measurement target hole according to the amount of movement of the moving axis;
a contact embedding means for limiting pressure transmission from the contact type displacement gauge to the contact via the moving shaft to embed the contact in the tip portion;
An inner diameter measuring instrument comprising: The internal diameter measuring instrument according to claim 5, characterized in that the contact embedding means limits the pressure transmission by blocking the pressure transmission path between the moving shaft and the contact. The contact embedding means is
an actuator that moves the movement shaft so that the pressure transmission path is formed;
7. The inner diameter measuring instrument according to claim 6, further comprising a spring member which biases the actuator in a direction opposite to the direction in which the actuator moves the moving shaft, and wherein the pressure transmission path is blocked by the biasing force of the spring member when the actuator is stopped from operating. The internal diameter measuring instrument according to claim 6, characterized in that the contact embedding means includes an actuator that moves the moving shaft so that the pressure transmission path is interrupted and also moves the moving shaft so that the pressure transmission path is formed. the contact embedding means includes a first actuator that moves the moving shaft so that the pressure transmission path is interrupted;
7. The inner diameter measuring instrument according to claim 6, further comprising a second actuator which moves the movement shaft so that the pressure transmission path is formed. a control means for controlling at least one of a speed at which the moving shaft is moved away from the contact by the contact burying means and a speed at which the moving shaft is brought into contact with the contact, so that the one speed is different from the other speed;
6. The inner diameter measuring instrument according to claim 5, wherein the speed of said contacting is lower than the speed of said separating. An inner diameter measuring instrument according to any one of claims 5 to 10,
an operation means for switching between burying the contacts and protruding the contacts by the contact burying means;
An inner diameter measuring device comprising: