Inner diameter measuring head device

Abstract

To provide an inner diameter measuring head device with which it is possible to measure the inner diameter of a hole, etc., of a measurement object with high accuracy.SOLUTION: An inner diameter measuring head device 1 comprises: a left and a right contact piece 131 capable of moving in the lateral direction so as to touch the inner circumferential surface IC of a hole HO to be measured from the inside of a head unit 100; a contact piece block 130 which is provided with the contact pieces 131; a conversion mechanism 150 for converting the movement amount of the contact pieces 131 into the movement amount in the axial direction; and an output shaft 140 for transmitting the movement amount in the axial direction. In the conversion mechanism 150, a contact ball 152 is in contact with an inclined surface 151 of the contact piece block 130 and an inclined surface 153 of the output shaft 140. When measuring the inner diameter ID of a workpiece WO, the inclined surface 151 moves laterally due to the movement of the contact pieces 131, and the contact ball 152 being in contact with the inclined surface 151 moves laterally. In this case, the contact ball 152 is slightly displaced rolling on the contact surface 153 of the output shaft 140.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an inner diameter measuring head device that is attached to a dial gauge or the like to measure the inner diameter of a hole or the groove width of a groove in a machine part or the like. [Background technology]

[0002] Dial gauges are used in a variety of measuring instruments because they can measure the length of an object with high accuracy through comparative measurement. Conventionally, an inner diameter measuring instrument using a dial gauge to measure the inner diameter of a hole in a mechanical part has been known (for example, Patent Document 1). This inner diameter measuring instrument converts the amount of radial movement obtained through comparative measurement into the amount of movement in the axial direction perpendicular to the radial direction, and measures the amount of axial movement using the dial gauge to measure the inner diameter of the hole. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6333970 Summary of the Invention [Problem to be solved by the invention]

[0004] The conventional inner diameter measuring instrument described in Patent Document 1 measures the inner diameter of a hole by transmitting the radial movement of a contactor that moves so that it can come into contact with the inner circumference of the hole to a shaft that is centered in the axial direction. However, this inner diameter measuring instrument has an elastically deformable section in part of the shaft that has a narrower shaft diameter, so if the tip of the shaft bends even slightly under the load of the contactor, the bending of the shaft could cause an error in the measurement value, which is the amount of movement in the axial direction of the shaft.

[0005] The problem that the technology of this specification aims to solve has been made in consideration of the above points, and its object is to provide an inner diameter measuring head device that can measure the inner diameter of a hole in a measured object such as a mechanical part with high accuracy. [Means for solving the problem]

[0006] The inner diameter measuring head device according to the embodiment of the present specification includes a cylindrical head portion to be inserted into a hole or the like of an object to be measured, a plurality of contact blocks disposed within the head portion so as to be movable in a direction perpendicular to the axis of the head portion, the contact blocks having inclined surfaces at their inner ends; a contact fixed to each of the contact blocks, the tip of which can contact the inner surface of the hole or the like and can protrude from the head portion, and the contact can move together with the contact block; an output shaft disposed substantially at the center of the head portion so as to be movable in the axial direction, the output shaft having a contact surface at its tip on the side of the hole, etc.; a sphere disposed in a space defined by the inclined surface of each of the contact blocks and in contact with the inclined surface and the contact surface of the output shaft; an inner diameter measuring head device which converts movement of the contact into movement of the output shaft via the contact block and the sphere, and outputs measurement information, The sphere is characterized in that it is in rolling contact with the contact surface of the output shaft.

[0007] This inner diameter measuring head device is attached to the holder mounting portion of a dial gauge or digital gauge. The head of the inner diameter measuring head device is inserted into a hole or other object being measured, and the tips of the several slightly protruding contacts contact the inner surface of the hole. The contacts move slightly inward, generating a radial displacement (amount of displacement from the reference value for comparative measurement) of the contacts. As the contacts move inward, the spheres move axially due to the inclined surfaces. This radial displacement is converted into an axial displacement, which is the axial displacement of the output shaft. At this time, the spheres in the inner space created by the inclined surfaces of the several contact blocks roll slightly on the contact surface of the output shaft and shift. As a result, bending stress is not applied to the shaft as in conventional methods, and the radial displacement of the contacts is accurately converted into axial displacement of the output shaft, enabling highly accurate measurement of the inner diameter of the hole or other object being measured.

[0008] Here, in the above inner diameter measuring head device, the contactor block can be attached within the head section via two support plates.

[0009] With this, the contact block of the contact is attached to the head by two support plates, so it can move without deviating from the direction perpendicular to the axis of the head, allowing for highly accurate measurement of the inner diameter of a hole in an object to be measured.

[0010] Furthermore, in the above-mentioned inner diameter measuring head device, the head portion has a cylindrical case, the two contacts are arranged on the diameter line of the cylindrical case in the measurement direction, and the tip portions of the two contacts can be configured to be able to protrude from two openings provided on the circumferential surface of the cylindrical case.

[0011] This allows the inner diameter of the hole in the object to be measured from two points in the diameter direction.

[0012] In the above-mentioned inner diameter measuring head device, the two support plates are fixed to a support fixing portion that fixes the base portions of the support plates, and the support fixing portion is screwed to the ceiling wall of the head portion, The support fixing portion may be provided with an adjustment screw for adjusting the position in the measurement direction.

[0013] With this, the position of the support fixing part that fixes the base parts of the two support plates can be adjusted in the measurement direction by the adjustment screw, thereby adjusting the amount of protrusion of the tip parts of the contacts.

[0014] In addition, in the above-mentioned inner diameter measuring head device, the inclined surface of the contact block can be configured to have surrounding walls surrounding the sphere at the front and rear in a front-to-rear direction perpendicular to the axial direction and the measurement direction.

[0015] This suppresses the movement of the sphere in the forward and backward directions, allowing the inner diameter of a hole in an object to be measured to be measured with higher accuracy. [Effects of the Invention]

[0016] According to the inner diameter measuring head device of the present invention, it is possible to measure the inner diameter of a hole in an object to be measured with high accuracy. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a partial cross-sectional view of an inner diameter measuring head device according to a first embodiment of the present invention in a measurement direction (left-right direction). [Figure 2] FIG. 2 is a partial cross-sectional view of the inner diameter measuring head device in the front-rear direction. [Figure 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 2 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 2 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 2. [Figure 8] 1A and 1B are enlarged cross-sectional views of the measurement direction of the head part of the same internal diameter measuring head device, where (A) is a view of the state in which the contactor has not moved out from the head part, and (B) is a view of the state in which the contactor has moved out from the head part. [Figure 9] FIG. 5 is a cross-sectional view in the measurement direction (left-right direction) of an inner diameter measuring head device according to a second embodiment of the present invention. [Figure 10] FIG. 2 is a partial cross-sectional view of the inner diameter measuring head device in the front-rear direction. [Figure 11] 10A and 10B are diagrams showing a contact block of an inner diameter measuring head device according to a third embodiment of the present invention, in which (A) is a plan view and (B) is a front view. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments. Figures 1 to 8 show an inner diameter measuring head device 1 according to a first embodiment for measuring the inner diameter ID of a hole HO to be measured in a workpiece WO. The inner diameter measuring head device 1 of the first embodiment is provided with measuring units 110 on both the left and right sides of the measurement direction within a head unit 100 having a cylindrical case 101 with an outer diameter OD that fits on the inner peripheral surface IC of the hole HO to be measured. The inner diameter measuring head device 1 includes left and right contactors 131 that contact the inner peripheral surface IC of the hole to be measured HO from inside the head unit 100 and are movable in the radial direction (left and right direction) of the head unit 100, left and right measuring units 110 that provide radial movement of the left and right contactors 131, a conversion mechanism 150 that converts a movement amount corresponding to the radial movement amount RD (radial movement amount RD1 + radial movement amount RD2) of the contactors 131 into an axial movement amount AD (here, a movement amount equal to the radial movement amount RD) in the axial direction perpendicular to the radial direction, and an output shaft 140 that moves axially in accordance with the movement of the contactors 131 and generates the axial movement amount AD. The axial movement amount AD of the output shaft 140 is output as measurement information to a dial gauge or digital gauge (not shown) that measures and displays the axial movement amount AD.

[0019] As shown in Figure 8(B), the radial movement amount RD1 is the radial movement amount of the left contact 131, the radial movement amount RD2 is the radial movement amount of the right contact 131, and the radial movement amount RD is the sum of the radial movement amounts on the left and right (radial movement amount RD1 + radial movement amount RD2).

[0020] For convenience, the orientation of the inner diameter measuring head device 1 in this specification is defined as follows: the side having the axial head unit 100 is defined as the bottom, and the side having the collet chuck 203 to which the dial gauge is attached is defined as the top, as shown in FIGS. 1 and 2. The left-right direction refers to the radial direction in which the contacts 131 and contact block 130 move. The front-rear direction refers to the direction perpendicular to the left-right direction and the up-down direction, respectively, and the side of the head unit 100 having the mounting screw 107a of the set ring 107 is defined as the front. The left-right direction is sometimes referred to as the measurement direction. In the drawings, F indicates the front, B indicates the rear, U indicates the top, D indicates the bottom, L indicates the left, and R indicates the right. Furthermore, the cylindrical case 101 of the head unit 100 is used as the reference point to refer to the inside or outside.

[0021] 1 to 3, the head unit 100 has a cylindrical case 101 as a container, and has openings 103 on the left and right sides of the bottom, through which the contacts 131 advance, and a central hole 102 in the center of the top wall 104, through which the output shaft 140 advances and retreats. The bottom of the cylindrical case 101 is open, and is closed by a cover 105.

[0022] The cylindrical case 101 constituting the head unit 100 is formed from steel. The outer diameter OD of the cylindrical case 101 is, for example, 40 mm -0.06 mm to -0.03 mm, which falls within the tolerance of φ40 mm ±0.000 mm to +0.100 mm for the hole HO to be measured. As shown in FIGS. 1 and 3, openings 103 through which contacts 131 advance are provided on the left and right sides of the lower side of the cylindrical case 101. As shown in FIG. 8, the left and right contacts 131 advance from the openings 103 and move until they contact the inner circumferential surface IC of the hole HO to be measured. The inner diameter ID of the hole HO to be measured is compared based on the radial movement amount RD (radial movement amount RD1 + radial movement amount RD2). Note that the radial movement amount RD is emphasized in FIG. 8(B) for ease of understanding.

[0023] As shown in Figures 1 and 8, the inner diameter measuring head device 1 of the embodiment has a measuring unit 110 on each of the left and right sides, which has a contact block 130, a contact 131, and two pairs of support plates 120, and the measuring unit 110 is formed on a plane connecting the central axis of the cylindrical head unit 100 in the measurement direction (left and right direction).

[0024] The contact block 130 is a substantially rectangular parallelepiped, and as shown in Fig. 8, is disposed on the left and right sides of the center of the lower side of the cylindrical case 101 so as to be movable left and right. An inner support plate 121 suspended from the ceiling wall 104 is connected to the inside of the upper part of the contact block 130 in the measurement direction, and an outer support plate 122 suspended from the ceiling wall 104 is connected to the outside of the measurement direction, so that the contact block 130 is suspended from the ceiling wall 104. The inner support plate 121 and the outer support plate 122 are slightly flexible, allowing the contact block 130 to move slightly in the measurement direction (left and right). The pair of support plates 120 (the inner support plate 121 and the outer support plate 122) are connected to the contact block 130 by two screws 134. A contactor 131 is attached to the contactor block 130 on the lower side of the connected outer support plate 122, facing outward in the measurement direction, and when the contactor block 130 moves in the measurement direction, the contactor 131 comes into contact with the inner surface IC of the hole HO to be measured.

[0025] The pair of support plates 120 (inner support plate 121 and outer support plate 122) are attached facing downward from the ceiling wall 104 inside the head unit 100 via support fixing parts 123, and suspend the contact block 130. The inner support plate 121 and outer support plate 122 of the pair of support plates 120 are formed into a substantially rectangular shape from metal plates having spring elasticity. In the measuring unit 110, the inner support plate 121 and outer support plate 122 are slightly deflected in the left-right direction, allowing the contact block 130 and contacts 131 to move slightly in the measurement direction (left-right direction).

[0026] The inner support plate 121 and the outer support plate 122 have a width in the front-to-rear direction. As shown in Fig. 2, the inner support plate 121 and the outer support plate 122 are each fixed to the contact block 130 by two screws 134 at the front and rear, and are each fixed to the support fixing part 123 by two screws 127 at the front and rear. Therefore, the pair of support plates 120 has a width in the front-to-rear direction that is the distance between the screws 134 or the distance between the screws 127, which makes it possible to further suppress twisting of the measuring part 110.

[0027] The support fixing part 123 to which the support plate pair 120 is attached is a substantially rectangular parallelepiped as shown in Fig. 4, and is attached to the ceiling wall 104 of the head unit 100 as shown in Fig. 8, with an inner support plate 121 connected to the inner side in the measurement direction and an outer support plate 122 connected to the outer side in the measurement direction on each of the left and right sides along the measurement direction. The support fixing part 123 has an insertion hole 123a in the vertical direction in the center, through which the output shaft 140 is inserted, and screw holes 123b in the vertical directions on the front and rear sides, which are attached to the ceiling wall 104 by screws 128 (Fig. 4). As shown in Fig. 2, the support fixing part 123 is attached to the ceiling wall 104 by the screws 128. The support plate pair 120 (the inner support plate 121 and the outer support plate 122) are connected to the support fixing part 123 by two screws 127.

[0028] 1 and 8, the position of the support fixing part 123 can be adjusted in the measurement direction by adjustment screws 124 that bias the support fixing part 123 from both the left and right sides as needed. This makes it possible to adjust the amount of protrusion of the contact 131 from the opening 103.

[0029] As shown in Figures 1 and 8, the adjustment screw 124 is inserted inward through adjustment holes 106 provided on both the left and right sides of the height at which the support fixing part 123 is attached on the upper end side of the cylindrical case 101 of the head part 100, and adjusts the position of the support fixing part 123 in the left-right direction (measurement direction).

[0030] The radial movement amount RD1 (radial movement amount RD2) of the contactor 131, which can protrude from the opening 103, is transmitted to a conversion mechanism 150, which converts the radial movement amount RD into an axial movement amount AD, by a contactor block 130 to which the contactor 131 is attached and which moves in conjunction with the contactor 131. The contactor block 130 is suspended from a support fixture 123 attached to the ceiling wall 104 of the head unit 100 by two pairs of support plates 120 (an inner support plate 121 and an outer support plate 122) that are parallel to each other. Because the radial movement of the contactor 131 and the contactor block 130 is restricted by the pair of support plates 120, the radial movement amount RD1 (radial movement amount RD2) of the contactor 131 is transmitted to the conversion mechanism 150 without deviation from the radial direction. Therefore, the inner diameter measuring head device 1 according to the embodiment exhibits high measurement accuracy.

[0031] As shown in Fig. 8, the conversion mechanism 150 converts the radial movement amount RD (radial movement amount RD1 + radial movement amount RD2) of the contactor 131 into an axial movement amount AD in the axial direction perpendicular to the radial direction. The conversion mechanism 150 is composed of inclined surfaces 151 in the front-rear direction on the inside of each of the left and right contactor blocks 130, a contact surface 153 on the underside of the output shaft 140, and abutting spheres 152 that abut against each of the inclined surfaces 151 and contact surface 153. When the inner diameter measuring head device 1 is attached to the dial gauge, the abutting spheres 152 are pressed downward by the output shaft 140 so that they are always in contact with the contact surface 153 of the output shaft 140 and the left and right inclined surfaces 151.

[0032] The inclined surfaces 151 are formed on the inner sides of the left and right contact blocks 130, respectively, and the inclined surfaces 151 in the front-rear direction are inclined outward with respect to the upward direction. Therefore, as shown in Fig. 8, when the left and right contacts 131 move outward from the head unit 100 by a radial movement amount RD1 (radial movement amount RD2) from a state in which the contacts 131 have not yet moved outward from the head unit 100 (Fig. 8(A)), the left and right inclined surfaces 151 each move outward, and the contact spheres 152 move downward by an axial movement amount AD. Accordingly, the output shaft 140, which presses the contact spheres 152 downward, also moves downward by the axial movement amount AD; in other words, the radial movement amount RD of the contacts 131 is converted into an axial movement amount AD.

[0033] The contact sphere 152 is a separate member from the output shaft 140, and can move left and right while in contact with a contact surface 153 of the output shaft 140. Therefore, even if the radial movement amounts RD1, RD2 of the left and right measuring units 110 are different and the centers of the two inclined surfaces 151, 151 deviate from the axial center of the output shaft 140, only the contact sphere 152 moves to the center of the two inclined surfaces 151, and the output shaft 140 does not deviate from the axial center. In other words, no bending stress is applied to the output shaft 140, which improves measurement accuracy.

[0034] The inclination angle of the inclined surface 151 relative to the central axis (FIGS. 1 and 8(A)) is not particularly limited, but is set to a calculated specific inclination angle α. This inclination angle α is calculated, for example, so that the ratio of the radial movement amount RD (radial movement amount RD1 + radial movement amount RD2) to the axial movement amount AD is 1:1. This allows the measurement information displayed by the dial gauge (spindle type) to be used as the movement amount from the reference value for comparison measurement.

[0035] As shown in FIG. 1, a cylindrical connecting part 145 is fixed facing upward at the center of the upper part of the cylindrical case 101 of the head part 100, and an output shaft 140 is inserted into the center hole of the cylindrical connecting part 145 via a bearing sphere 144 so as to be movable in the axial direction within a predetermined range, with the upper end of the output shaft 140 protruding upward from the cylindrical connecting part 145.

[0036] 1, a stop ring 142 is attached to the output shaft 140, and a metal collar 143 that limits the amount of movement is fitted under the stop ring 142. This limits the axial movement of the output shaft 140, and when the output shaft 140 is urged downward during measurement, the amount of protrusion of the contact 131 from the head portion 100 can be set to a constant amount.

[0037] The axial movement amount AD is transmitted from the output shaft 140 to the connecting shaft 210, and then from the connecting shaft 210, it is finally transmitted to the contact point 301 of the dial gauge. Because the axial movement amount AD is transmitted to the contact point 301 of the dial gauge via the contact point between the output shaft 140 and the connecting shaft 210, even if twisting occurs in the connecting tube 200, for example, the contact point absorbs the twist, and the output shaft 140 and the connecting shaft 210 can transmit the axial movement amount AD to the contact point 301 of the dial gauge.

[0038] The inner diameter measuring head device 1 configured as described above is fixed to a holder mounting portion of a dial gauge (not shown) via a connecting tube 200. As shown in Fig. 1, the connecting tube 200 is configured by fixing a cylindrical body 202 inside a grip tube 201, and inserting a connecting shaft 210 onto the central axis of the cylindrical body 202 via a bearing 204 so that the connecting tube 200 is movable within a predetermined range. The connecting tube 200 transmits the axial movement amount AD to the measuring point 301 of the dial gauge, and also functions as a grip that the operator holds when measuring the inner diameter ID of the hole to be measured HO.

[0039] 1, the output shaft 140 that transmits the axial movement amount AD and the connecting shaft 210 are slidably connected to the axial center of the connecting tube 200, and a collet chuck 203 to which a dial gauge is attached is connected to the upper end side of the connecting tube 200. As shown in FIG. 5, a bearing sphere 144 is inserted around the radial periphery of the upper end side of the output shaft 140 to smooth the sliding of the output shaft 140 and suppress twisting of the output shaft 140.

[0040] The dial gauge has its probe 301 inserted into the collet chuck 203 of the connecting tube 200, and with the probe 301 abutting the upper end of the connecting shaft 210, the holder mounting portion (not shown) of the dial gauge is tightened and fixed by the collet chuck 203.

[0041] Next, we will explain the method for measuring the inner diameter ID of the measurement hole HO using the inner diameter measuring head device 1. When measuring the inner diameter ID, first, calibration is performed using a calibration master for the inner diameter ID, and then the inner diameter ID is measured.

[0042] In calibration, the head unit 100 is inserted into the hole HO to be measured in the calibration master for the inner diameter ID, and the axial movement AD (radial movement RD) is calibrated to 0 mm when the left and right contactors 131 are brought into contact with the inner surface IC of the hole HO to be measured. As a result, the axial movement AD in measuring the inner diameter ID of the workpiece WO to be measured represents the difference in length from the inner diameter ID of the hole HO to be measured in the master guide, which is the comparison measurement.

[0043] The inner diameter ID of the workpiece WO is measured by inserting the head unit 100 into the hole HO to be measured in the workpiece WO, pressing down the probe 301 of the dial gauge, and moving the left and right contactors 131 outward until they come into contact with the inner surface IC of the hole HO to be measured. The movement of the contactors 131 (contactor block 130) is restricted in the radial direction by the pair of support plates 120 of the measuring unit 110, thereby improving measurement accuracy.

[0044] The radial movement amount RD (radial movement amount RD1 + radial movement amount RD2) caused by the movement of the contact 131 moves the inner inclined surfaces 151 of the left and right contact blocks 130 outward or inward, respectively, and the abutting spheres 152 serving as contact surfaces 153 move downward or upward by the axial movement amount AD depending on the angle of the inclined surfaces 151. Accordingly, the output shaft 140 also moves downward or upward by the axial movement amount AD, and the radial movement amount RD is converted into the axial movement amount AD.

[0045] The axial movement amount AD is transmitted to the contact point 301 of the spindle-type dial gauge via the connecting shaft 210. The dial gauge measures the axial movement amount AD by moving the contact point 301, and displays the difference in length from the inner diameter ID (40 mm) of the measured hole HO of the master guide, which is a comparative measurement of the measured measured hole HO, as measurement information.

[0046] The inner diameter measuring head device 1 of this embodiment is attached to the holder mounting portion of a dial gauge when in use. The head portion 100 of the inner diameter measuring head device 1 is inserted into a measurement hole HO or the like of an object to be measured, and the tips of the slightly protruding contacts 131 come into contact with the inner circumferential surface IC of the hole. The contacts 131 move slightly inward, causing a radial movement amount RD (movement amount from the reference value for comparative measurement) of the contacts 131. As the contacts 131 move inward, the inclined surfaces 151 cause the abutting spheres 152 to move axially. Therefore, the radial movement amount RD is converted into an axial movement amount AD, which is the axial movement amount of the output shaft 140. At this time, the abutting spheres 152 in the inner space formed by the inclined surfaces 151 of the multiple contact blocks 130 roll slightly and shift against the contact surfaces 153 of the output shaft 140. Therefore, unlike conventional methods, bending stress is not applied to the shaft, and the radial movement amount RD of the contactor 131 is correctly converted into the axial movement amount AD of the output shaft 140, making it possible to measure the inner diameter ID of the measurement hole HO of the object to be measured with high accuracy.

[0047] The inner diameter measuring head device 1 of the embodiment can also be implemented in the following forms as other embodiments.

[0048] In the inner diameter measuring head device 1 of the first embodiment, two measuring units 110 are used, facing each other on the left and right, but it is also possible to use two or three measuring units 110 arranged at equal intervals in the circumferential direction. In this case, the inclination angle α can be set to 26.565°.

[0049] 9 and 10 show an inner diameter measuring head apparatus 1B of a second embodiment for measuring inner diameters that are smaller than those of the first embodiment. The inner diameter measuring head apparatus 1B of the second embodiment has a cylindrical case 101 with a small outer diameter, and is similar to the inner diameter measuring head apparatus 1 of the above-mentioned embodiment except that no support fixing portion or adjustment screw is provided inside the cylindrical case 101. In the inner diameter measuring head apparatus 1B, components that are the same as those of the inner diameter measuring head apparatus 1 are given the same reference numerals, and their description will be omitted. The usage form and actions and effects of this inner diameter measuring head apparatus 1B are also similar to those of the inner diameter measuring head apparatus 1 of the above-mentioned embodiment.

[0050] 11 shows a contactor block 130C of an inner diameter measuring head device 1C of a third embodiment, in which a surrounding wall 132 surrounding a contact sphere 152 is provided on the inclined surface 151 of the contactor block 130 of the inner diameter measuring head device 1 of the first embodiment. The inner diameter measuring head device 1C of the third embodiment is similar to the inner diameter measuring head device 1 of the above-mentioned embodiment, except that a surrounding wall 132 is provided on the inclined surface 151 of the contactor block 130C. Note that in the inner diameter measuring head device 1C, components that are the same as those in the inner diameter measuring head device 1 will be denoted by the same reference numerals, and their description will be omitted.

[0051] In the inner diameter measuring head device 1C of the third embodiment, surrounding walls 132 are provided on the inclined surface 151 of one of the left and right contact blocks 130C (the right side in FIG. 11 ) at the front and rear of the inclined surface 151, which surrounds the contact sphere 152 in a front-to-rear direction perpendicular to the up-down direction (axial direction) and the left-to-right direction (measurement direction). The surrounding walls 132 are arranged parallel to each other perpendicular to the front-to-rear direction, and the contact sphere 152 is sandwiched between the front and rear surrounding walls 132. A small gap between the contact sphere 152 and the surrounding wall 132 allows the contact sphere 152 to move without being locked. The surrounding wall 132 restricts the movement of the contact sphere 152 in the front-to-rear direction, allowing the left and right contact blocks 130, 130C to move in the measurement direction while suppressing slight tilt in the front-to-rear direction. This allows the inner diameter measuring head device 1C to measure the inner diameter of a hole in an object to be measured with higher accuracy. [Explanation of symbols]

[0052] 1...inner diameter measuring head device, 1B...inner diameter measuring head device, 1C...inner diameter measuring head device, 100...head portion, 101...cylindrical case, 102...center hole, 103...opening, 104...ceiling wall, 105...cover, 107...set ring, 107a...mounting screw, 110...measuring portion, 120...support plate pair, 121...inner support plate, 122...outer support plate, 123...support fixing portion, 123a...insertion hole, 123b...screw hole, 124...adjusting screw, 127...screw, 128...screw, 130...contact block, 130C...contact block, 131...contact, 132...enclosure wall, 134...Screw, 140...Output shaft, 142...Retaining ring, 143...Collar, 144...Bearing sphere, 145...Cylindrical connecting portion, 150...Conversion mechanism, 151...Inclined surface, 152...Abutting sphere, 153...Contact surface, 200...Connecting tube, 201...Grip tube, 202...Cylindrical body, 203...Collet chuck, 204...Bearing, 210...Connecting shaft, 301...Measuring element, AD...Axial movement amount, HO...Measured hole, IC...Inner peripheral surface, ID...Inner diameter, OD...Outer diameter, RD...Radial movement amount, RD1...Radial movement amount, RD2...Radial movement amount, WO...Workpiece, α...Angle.

Claims

1. a cylindrical head portion to be inserted into a hole or the like of the object to be measured; a plurality of contact blocks disposed within the head portion so as to be movable in a direction perpendicular to the axis of the head portion, the contact blocks having inclined surfaces at their inner ends; a contact fixed to each of the contact blocks, the tip of which can contact the inner surface of the hole or the like and can protrude from the head portion, and the contact can move together with the contact block; an output shaft disposed substantially at the center of the head portion so as to be movable in the axial direction, the output shaft having a contact surface at its tip on the side of the hole, etc.; a sphere disposed in a space defined by the inclined surface of each of the contact blocks, in contact with the inclined surface and in rollable contact with the contact surface of the output shaft; an inner diameter measuring head device which converts movement of the contact into movement of the output shaft via the contact block and the sphere, and outputs measurement information, The contact block is attached within the head portion via two support plates, The two support plates are fixed to a support fixing portion that fixes the base portions of the support plates, and the support fixing portion is screwed to the ceiling wall of the head portion, The inner diameter measuring head device is characterized in that the supporting and fixing part is provided with an adjustment screw for adjusting the position in the measurement direction.

2. 2. An inner diameter measuring head device according to claim 1, characterized in that the head portion has a cylindrical case, the two contacts are arranged on a diameter line of the cylindrical case in the measurement direction, and the tip portions of the two contacts can protrude from two openings provided on the circumferential surface of the cylindrical case.

3. An internal diameter measuring head device as described in claim 1 or 2, characterized in that the support plate is formed into an approximately rectangular shape from a metal plate having spring elasticity.

4. An internal diameter measuring head device as described in Claim 3, characterized in that the support plate has a width in the front-to-back direction, is fixed to the contact block by two screws at the front and back, and is fixed to the support fixing portion by two screws at the front and back.

5. An inner diameter measuring head device as described in any one of claims 1 to 4, characterized in that the inclined surface of the contactor block has an enclosure wall surrounding the sphere at the front and rear in a front-to-rear direction perpendicular to the axial direction and the measurement direction.

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