Measuring accessory for measuring size of concave hole and caliper thereof

Abstract

The utility model discloses a measuring accessory for measuring the size of a concave hole and a caliper thereof, which belong to the technical field of measuring appliances and comprise a chuck, a clamping groove and a measuring pin are arranged on the chuck, an elastic component is arranged on the clamping groove, and a measuring pin dismounting piece is arranged between the measuring pin and the chuck. The measuring pin is assembled and disassembled on the clamping head through the measuring pin assembling and disassembling piece and extends towards the outer side of the clamping head in the assembling process. According to the structure, the measuring pin is disassembled and assembled on the chuck by using the disassembling and assembling function of the measuring pin disassembling and assembling part, and the elastic assembly is moved on the clamping groove, so that the size in the clamping groove is increased or reduced, and the chuck is disassembled and assembled on a conventional caliper, so that the conventional caliper can randomly disassemble and assemble measuring accessories according to actual measuring requirements; according to the invention, a user can complete the measurement of the sizes such as the in-hole width and depth of the concave part through the disassembly and assembly of the measurement accessory under the condition that the user does not need to buy a special caliper again, the use cost is reduced, the measuring pin can be disassembled and replaced, the user can replace the measuring pins with different lengths according to the size of the concave hole to be measured, and the disassembled measurement accessory is convenient to carry.

Description

Technical Field

[0001] The utility model relates to the technical field of measuring instruments, in particular to a measuring accessory and a caliper thereof for measuring the size of a concave hole. Background Art

[0002] A vernier caliper is a measuring tool used to measure length, inner and outer diameters, and depth. Examples include a vernier caliper disclosed in Chinese utility model patent No. CN201720871902.1, a vernier caliper disclosed in utility model patent No. CN201120119800.7, a vernier caliper used for measuring the spacing between the outer edges of grooves within a hole disclosed in utility model patent No. CN201420840097.2, and a vernier caliper for measuring the depth of wide-mouth grooves disclosed in utility model patent No. CN201320121010.1. However, for measuring dimensions such as the width and depth of the holes of concave parts, the measuring heads of these vernier calipers are generally of a fixed length. If the width or depth of the concave hole is large, the measuring head cannot reach the inner groove edge, resulting in measurement failure. Providing dedicated calipers for different concave hole measurement situations would be a significant cost waste. Therefore, further improvements are necessary. Utility Model Content

[0003] The utility model aims to provide a measuring accessory and a caliper thereof for measuring the size of a concave hole, so as to overcome the deficiencies in the prior art.

[0004] A measuring accessory designed for this purpose for measuring the size of a recessed hole includes a chuck, a chuck provided with a chuck groove and a measuring needle, a tensioning assembly provided on the chuck groove, a measuring needle disassembly component provided between the measuring needle and the chuck, the measuring needle being disassembled and assembled on the chuck via the measuring needle disassembly component and extending toward the outside of the chuck during assembly.

[0005] One side of the clamping groove is open and provided with a clamping groove opening, and the other side is closed and provided with a positioning wall inside the clamping groove. A clamping head protrusion is also extended from the closed side of the clamping groove, and an assembly hole is provided in the clamping head protrusion. The measuring needle is disassembled and assembled on the assembly hole. The measuring needle disassembly part is disassembled and assembled on the clamping head protrusion by means of threads, snaps, magnets, or adhesives, and the measuring needle is fixed on the assembly hole during assembly.

[0006] The chuck convex part is provided with a convex external thread, the measuring needle disassembly part is axially penetrated by a connecting hole, the interior of the connecting hole is provided with a disassembly internal thread, and the disassembly internal thread cooperates with the convex external thread.

[0007] The assembly hole axially passes through the chuck protrusion, or the chuck protrusion is provided with a positioning step corresponding to the assembly hole.

[0008] The chuck protrusion is conically protruded on the outside of the chuck and is provided with a clamping notch in its axial direction. There are a number of clamping notches arranged in a circular array along the periphery of the chuck protrusion. The internal shape of the measuring needle disassembly part matches the shape of the chuck protrusion, and a disassembly anti-slip part is also provided on the periphery of the measuring needle disassembly part.

[0009] The elastic component is provided with one and is movable and retractable on one side of the clamping groove, or the elastic component is provided with two and is movable and retractable on opposite sides of the clamping groove respectively.

[0010] The said tensioning assembly is provided with two, which are respectively a raised tensioning assembly and a flush tensioning assembly, the raised tensioning assembly includes a cam pressure plate and a cam adjusting member, the flush tensioning assembly includes a flush pressure plate and a flush adjusting member, wherein the cam pressure plate and the flush pressure plate are respectively arranged on the two opposite inner sides of the clamping groove, the cam adjusting member and the flush adjusting member are respectively rotated and adjusted on the two opposite outer sides of the clamping groove, and are respectively driven and connected with the cam pressure plate and the flush pressure plate when rotating.

[0011] The clamping groove is provided with a first clamping groove recess on an inner side, and a clamping groove protrusion on an outer side, the first clamping groove recess is provided on the first clamping groove recess, the clamping groove protrusion is provided with a first internal threaded hole, the first internal threaded hole and the second clamping groove protrusion are connected to each other, the cam pressure plate is provided on the first clamping groove recess, and a cam pressure plate boss is provided on it, the cam pressure plate boss is provided on the second clamping groove recess, and an arc-shaped recess is provided on it, and a plurality of boss notches are provided in an annular array around the cam pressure plate boss, a cam thread column is provided on the cam adjusting member, and the cam thread column cooperates with the first internal threaded hole, a cam driving member is provided at the end of the cam thread column, and is driven and connected to the arc-shaped recess through the cam driving member, and a cam adjustment anti-slip portion is also provided on the periphery of the cam adjusting member, and the cam adjustment anti-slip portion is located on the outer side of the clamping groove protrusion.

[0012] A third recess of the clamping groove is provided on the other inner side of the clamping groove, a second internal threaded hole and a limiting portion are provided on the third recess of the clamping groove, the flush pressure plate is provided on the third recess of the clamping groove, and a flush pressure plate boss and a limiting matching portion are provided on it, the flush pressure plate boss is located on the second internal threaded hole, the limiting matching portion cooperates with the limiting portion, a flush adjustment external thread is provided on the flush adjustment part, and the flush adjustment external thread cooperates with the second internal threaded hole, the inner side surface of the flush adjustment part is drivingly connected to the flush pressure plate boss, and the outer side surface is provided with an adjustment action portion.

[0013] The above-mentioned measuring accessories can be disassembled and assembled on the caliper. The caliper includes a main scale and a vernier. The zero scale end of the main scale is provided with a first caliper arm, and the zero scale end of the vernier is provided with a second caliper arm. The first caliper arm and the second caliper arm are symmetrical to each other.

[0014] The measuring accessory is provided with one and is assembled and disassembled on the first caliper arm or the second caliper arm through the cooperation of the clamping groove and the elastic assembly, or the measuring accessory is provided with two, the two measuring accessories are symmetrical facing each other, and are respectively assembled and disassembled on the first caliper arm and the second caliper arm through the cooperation of the clamping groove and the elastic assembly.

[0015] The present invention improves the above structure and utilizes the disassembly and assembly function of the measuring needle disassembly part so that the measuring needle can be disassembled and assembled on the chuck, and at the same time utilizes the elastic component to move on the clamping groove to make the inner size of the clamping groove larger or smaller, so that the chuck can be disassembled and assembled on the conventional caliper, so that the conventional caliper can freely disassemble and assemble the measuring accessories according to actual measurement needs, effectively solving the disadvantage that the conventional caliper of the prior art cannot measure the size of the concave hole, allowing the user to complete the measurement of the width, depth and other dimensions of the hole of the concave part by disassembling and assembling the measuring accessories without having to repurchase a special caliper, thereby greatly reducing the cost of use. In addition, the measuring needle can also be disassembled and replaced, allowing the user to replace measuring needles of different lengths according to the size of the concave hole to be measured. It has a wide range of uses, and the disassembled measuring accessories are easy to carry, thereby improving the user's usage experience and flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a schematic diagram of the assembly structure of the measuring accessory and the caliper according to one embodiment of the present invention.

[0017] Figure 2 The figure is a schematic diagram of the exploded structure of the measuring accessory and the caliper according to one embodiment of the present invention.

[0018] Figure 3 This is a schematic diagram of the assembly structure of the measuring accessory according to one embodiment of the present utility model.

[0019] Figure 4 This is a schematic diagram of the assembly structure of the measuring accessory from another perspective of an embodiment of the present utility model.

[0020] Figure 5 This is a schematic diagram of the exploded structure of a measuring accessory according to an embodiment of the present invention.

[0021] Figure 6 This is a schematic diagram of the exploded structure of the measuring accessory of one embodiment of the present invention from another perspective.

[0022] Figure 7This is a schematic diagram of the assembled cross-sectional structure of a measuring accessory according to an embodiment of the present utility model.

[0023] Figure 8 Schematic diagram of the structure of the chuck.

[0024] Figure 9 It is a schematic diagram of the cross-sectional structure of the chuck.

[0025] Figure 10 This is a structural diagram of the measuring needle disassembly and assembly parts.

[0026] Figure 11 It is a schematic diagram of the cross-sectional structure of the measuring needle disassembly and assembly parts.

[0027] Figure 12 It is a structural diagram of the cam pressure plate.

[0028] Figure 13 It is a schematic diagram of the cross-sectional structure of the cam pressure plate.

[0029] Figure 14 It is a structural diagram of the cam adjustment component.

[0030] Figure 15 Schematic diagram of the structure of the flush pressure plate. DETAILED DESCRIPTION

[0031] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0033] See also Figures 1-15 The measuring accessory X for measuring the size of a recessed hole comprises a chuck 1, a chuck groove 11 and a measuring needle 2 are provided on the chuck 1, a tensioning assembly is provided on the chuck groove 11, a measuring needle disassembly component 3 is provided between the measuring needle 2 and the chuck 1, and the measuring needle 2 is disassembled and assembled on the chuck 1 through the measuring needle disassembly component 3 and extends toward the outside of the chuck 1 during assembly.

[0034] This embodiment utilizes the disassembly and assembly function of the measuring needle disassembly and assembly part 3 so that the measuring needle 2 can be disassembled and assembled on the chuck 1, and at the same time utilizes the elastic component to move on the clamping groove 11 to make the groove size of the clamping groove 11 larger or smaller, so that the chuck 1 can be disassembled and assembled on the conventional caliper, so that the conventional caliper can freely disassemble and assemble the measuring accessory X according to actual measurement needs, effectively solving the disadvantage that the conventional caliper in the prior art cannot measure the size of the concave hole, allowing users to complete the measurement of the width, depth and other dimensions of the hole of the concave part by disassembling and assembling the measuring accessory X without having to repurchase a special caliper, thereby greatly reducing the cost of use. In addition, the measuring needle 2 can also be disassembled and replaced, allowing users to replace measuring needles 2 of different lengths according to the size of the concave hole to be measured, having a wide range of uses, and the measuring accessory X is easy to carry after disassembly, thereby improving the user's usage experience and flexibility.

[0035] In this embodiment, the measuring needle 2 can be set to different lengths, such as 20 mm, 30 mm, 50 mm, etc. The measuring accessory X can be suitable for measuring the width and depth of different recessed holes by replacing the measuring needles 2 of different lengths.

[0036] Specifically, the measuring accessory X can be disassembled and assembled on a caliper, which can be a digital caliper, a pointer caliper, or a scale caliper, wherein the caliper includes a main scale 100 and a vernier 200, and the zero scale end of the main scale 100 is provided with a first caliper arm 101, and the zero scale end of the vernier 200 is provided with a second caliper arm 201, and the first caliper arm 101 and the second caliper arm 201 are symmetrical towards each other.

[0037] One measuring accessory X is provided, and is assembled and disassembled on the first caliper arm 101 or the second caliper arm 201 by cooperating with the clamping groove 11 and the elastic assembly. Alternatively, two measuring accessories X are provided, and the two measuring accessories X are symmetrical facing each other and are respectively assembled and disassembled on the first caliper arm 101 and the second caliper arm 201 by cooperating with the clamping groove 11 and the elastic assembly.

[0038] In this embodiment, two measuring accessories X are preferably provided. The two measuring accessories X are respectively assembled and disassembled on the first caliper arm 101 and the second caliper arm 201 through the cooperation of the clamping groove 11 and the elastic assembly. After the two measuring accessories X are assembled, the measuring needles 2 of the two are symmetrically facing each other. When in use, the two measuring needles 2 are respectively extended into the concave hole and can respectively contact the inner groove edge of the concave hole, thereby realizing the measurement of the concave hole size.

[0039] One side of the clamping groove 11 is open and provided with a clamping groove opening 12, and the other side is closed and provided with a clamping groove inner positioning wall 13. A clamping head protrusion 14 is also extended from the closed side of the clamping groove 11, and an assembly hole 15 is provided in the clamping head protrusion 14. The measuring needle 2 is disassembled and assembled on the assembly hole 15. The measuring needle disassembly part 3 is disassembled and assembled on the clamping head protrusion 14 by screw threads, snaps, magnets, or adhesives, and the measuring needle 2 is fixed on the assembly hole 15 during assembly.

[0040] In this embodiment, the cross-section of the clamping groove 11 is C-shaped, and can be assembled on the first caliper arm 101 and the second caliper arm 201 through its C-shape, which makes assembly convenient. At the same time, the positioning wall 13 in the clamping groove relies on the first caliper arm 101 and the second caliper arm 201, and the assembly is stable and the positioning is accurate.

[0041] The chuck protrusion 14 is provided with a protrusion external thread, the measuring needle disassembly component 3 is axially penetrated by a connecting hole, the inside of the connecting hole is provided with a disassembly internal thread 31, and the disassembly internal thread 31 cooperates with the protrusion external thread.

[0042] This embodiment utilizes the cooperation of the disassembly internal thread 31 and the convex external thread to enable the measuring needle disassembly component 3 to be disassembled and assembled on the chuck 1, and the assembly is convenient and stable.

[0043] The assembly hole 15 axially passes through the chuck protrusion 14 , or the chuck protrusion 14 is provided with a positioning step corresponding to the assembly hole 15 .

[0044] In this embodiment, the assembly hole 15 axially passes through the chuck protrusion 14, and the measuring needle 2 is inserted into the assembly hole 15 during assembly. The inner end face of the measuring needle 2 is flush with the positioning wall 13 in the clamping groove, and is positioned on the first caliper arm 101 and the second caliper arm 201. The measuring needle 2 is then fixed using the measuring needle disassembly and assembly part 3.

[0045] The chuck protrusion 14 is conically convexly arranged on the outside of the chuck 1, and a clamping notch 16 is arranged axially therein. There are a number of clamping notches 16 arranged in a circular array along the periphery of the chuck protrusion 14. The internal shape of the measuring needle disassembly part 3 matches the shape of the chuck protrusion 14, and a disassembly anti-slip part 32 is also provided on the periphery of the measuring needle disassembly part 3.

[0046] In this embodiment, the conical protruding chuck protrusion 14 can utilize the alignment of the measuring needle disassembly component 3 to facilitate the assembly of the measuring needle disassembly component 3. At the same time, the measuring needle disassembly component 3 can drive the multiple clamping notches 16 to shrink and clamp the measuring needle 2 during assembly, thereby ensuring that the measuring needle 2 is firmly assembled.

[0047] One elastic component is provided and is movable and retractable on one side of the clamping groove 11 , or two elastic components are provided and are movable and retractable on opposite sides of the clamping groove 11 .

[0048] When one tensioning assembly is provided, it cooperates with the other side of the clamping groove 11 to clamp and fix the first caliper arm 101 and the second caliper arm 201. When two tensioning assemblies are provided, the two can clamp and fix the first caliper arm 101 and the second caliper arm 201.

[0049] That is, the tensioning assembly in this embodiment can be set on any caliper arm of the caliper to complete the measurement of the width, depth and other dimensions of the single-sided hole of the concave part. The tensioning assembly can also be set on both caliper arms of the caliper at the same time to complete the measurement of the width, depth and other dimensions of the double-sided hole of the concave part.

[0050] In this embodiment, there are preferably two tensioning assemblies, which are respectively a raised tensioning assembly and a flush tensioning assembly. The raised tensioning assembly includes a cam pressure plate 4 and a cam adjusting member 5, and the flush tensioning assembly includes a flush pressure plate 6 and a flush adjusting member 7. The cam pressure plate 4 and the flush pressure plate 6 are respectively arranged on the two opposite inner sides of the clamping groove 11, and the cam adjusting member 5 and the flush adjusting member 7 are respectively rotated and adjusted on the two opposite outer sides of the clamping groove 11, and are respectively driven and connected with the cam pressure plate 4 and the flush pressure plate 6 when rotating.

[0051] The first recessed portion 17 of the clamping groove is provided on the inner side of the clamping groove 11, and the protruding portion 18 of the clamping groove is provided on the outer side. The second recessed portion 19 of the clamping groove is provided on the first recessed portion 17 of the clamping groove. The first internal threaded hole 110 is provided in the protruding portion 18 of the clamping groove. The first internal threaded hole 110 and the second recessed portion 19 of the clamping groove are communicated with each other. The cam pressing plate 4 is provided on the first recessed portion 17 of the clamping groove and a cam pressing plate boss 41 is provided on it. The cam pressing plate boss 41 is provided on the second recessed portion 19 of the clamping groove and an arc is provided on it. shaped recess 42, a plurality of boss notches 43 are provided in a circular array around the cam pressure plate boss 41, a cam thread column 51 is provided on the cam adjusting member 5, and cooperates with the first internal threaded hole 110 through the cam thread column 51, a cam driving portion 52 is provided at the end of the cam thread column 51, and is driven and connected to the arc-shaped recess 42 through the cam driving portion 52, and a cam adjustment anti-slip portion 53 is also provided on the periphery of the cam adjusting member 5, and the cam adjustment anti-slip portion 53 is located on the outside of the clamping groove convex portion 18.

[0052] A third recess 111 of the clamping groove is provided on the other inner side of the clamping groove 11, and a second internal threaded hole 112 and a limiting portion 113 are provided on the third recess 111 of the clamping groove. The flush pressure plate 6 is provided on the third recess 111 of the clamping groove, and a flush pressure plate boss 61 and a limiting matching portion 62 are provided thereon. The flush pressure plate boss 61 is located on the second internal threaded hole 112, and the limiting matching portion 62 cooperates with the limiting portion 113. A flush adjustment external thread 71 is provided on the flush adjustment member 7, and the flush adjustment external thread 71 cooperates with the second internal threaded hole 112. The inner side surface of the flush adjustment member 7 is drivingly connected to the flush pressure plate boss 61, and the outer side surface is provided with an adjustment action portion 72.

[0053] In this embodiment, the user can use his hand to act on the cam adjustment anti-slip part 53 to make the cam adjustment part 5 rotate on one side of the chuck 1 and drive the cam pressure plate 4 to move and retract on one side of the clamping groove 11. The user can also use a tool to act on the adjustment action part 72 to make the leveling adjustment part 7 rotate on the other side of the chuck 1 and drive the leveling pressure plate 6 to move and retract on the other side of the clamping groove 11. The cam pressure plate 4 and the leveling pressure plate 6 clamp or release the first caliper arm 101 and the second caliper arm 201 when extending and retracting, thereby realizing the disassembly and assembly of the measuring accessory X and the first caliper arm 101 and the second caliper arm 201.

[0054] The above is a preferred embodiment of the present invention, which illustrates and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention, which is defined by the appended claims and their equivalents.

Claims

1. A measuring accessory for measuring the size of a recessed hole, comprising a chuck (1), characterized in that: The chuck (1) is provided with a chuck groove (11) and a measuring needle (2), the chuck groove (11) is provided with a loosening assembly, a measuring needle disassembly component (3) is provided between the measuring needle (2) and the chuck (1), and the measuring needle (2) is disassembled from the chuck (1) through the measuring needle disassembly component (3) and extends toward the outside of the chuck (1) when assembled.

2. The measuring accessory for measuring concave hole size according to claim 1, characterized in that: One side of the clamping groove (11) is open and provided with a clamping groove opening (12), and the other side is closed and provided with a clamping groove inner positioning wall (13). A clamping head protrusion (14) is also extended from the closed side of the clamping groove (11), and an assembly hole (15) is provided in the clamping head protrusion (14). The measuring needle (2) is disassembled and assembled on the assembly hole (15). The measuring needle disassembly component (3) is disassembled and assembled on the clamping head protrusion (14) by screw thread, snap fastener, magnetism, or adhesion, and the measuring needle (2) is fixed on the assembly hole (15) during assembly.

3. The measuring accessory for measuring concave hole size according to claim 2, characterized in that: The chuck convex portion (14) is provided with a convex external thread, the measuring needle disassembly component (3) is axially penetrated by a connecting hole, and a disassembly internal thread (31) is provided inside the connecting hole, and the disassembly internal thread (31) cooperates with the convex external thread.

4. The measuring accessory for measuring concave hole size according to claim 3, characterized in that: The assembly hole (15) axially passes through the chuck protrusion (14), or the chuck protrusion (14) is provided with a positioning step corresponding to the assembly hole (15).

5. The measuring accessory for measuring concave hole size according to claim 3, characterized in that: The chuck protrusion (14) is conically convexly arranged on the outside of the chuck (1), and a clamping notch (16) is arranged axially. The clamping notches (16) are arranged in a plurality and arranged in a circular array along the periphery of the chuck protrusion (14). The internal shape of the measuring needle disassembly component (3) matches the shape of the chuck protrusion (14), and a disassembly component anti-slip portion (32) is also arranged on the periphery of the measuring needle disassembly component (3).

6. The measuring accessory for measuring concave hole size according to claim 1, characterized in that: The elastic component is provided with one and is movably retractable on one side of the clamping groove (11), or the elastic component is provided with two and is movably retractable on opposite sides of the clamping groove (11).

7. The measuring accessory for measuring concave hole size according to claim 6, characterized in that: The tensioning assembly is provided with two, which are respectively a raised tensioning assembly and a flush tensioning assembly. The raised tensioning assembly includes a cam pressure plate (4) and a cam adjusting member (5), and the flush tensioning assembly includes a flush pressure plate (6) and a flush adjusting member (7). The cam pressure plate (4) and the flush pressure plate (6) are respectively arranged on two opposite inner sides of the clamping groove (11), and the cam adjusting member (5) and the flush adjusting member (7) are respectively rotated and adjusted on two opposite outer sides of the clamping groove (11), and are respectively driven and connected with the cam pressure plate (4) and the flush pressure plate (6) when rotating.

8. The measuring accessory for measuring concave hole size according to claim 7, characterized in that: The clamping groove (11) is provided with a first clamping groove concave portion (17) on an inner side and a clamping groove convex portion (18) on an outer side. A second clamping groove concave portion (19) is provided on the first clamping groove concave portion (17). A first internal threaded hole (110) is provided in the clamping groove convex portion (18). The first internal threaded hole (110) and the second clamping groove concave portion (19) are communicated with each other. The cam pressure plate (4) is provided on the first clamping groove concave portion (17) and a cam pressure plate boss (41) is provided on the cam pressure plate boss (41). The cam pressure plate boss (41) is provided on the second clamping groove concave portion (19) and an arc-shaped concave hole is provided on the cam pressure plate boss (41). The cam pressure plate boss (41) has a plurality of boss notches (43) in a peripheral annular array. The cam adjusting member (5) is provided with a cam thread column (51), and the cam thread column (51) cooperates with the first internal thread hole (110). The end of the cam thread column (51) is provided with a cam driving member (52), and is driven and connected to the arc-shaped recessed portion (42) through the cam driving member (52). The cam adjusting member (5) is also provided with a cam adjusting anti-slip portion (53) on the periphery, and the cam adjusting anti-slip portion (53) is located outside the clamping groove convex portion (18).

9. The measuring accessory for measuring concave hole size according to claim 8, characterized in that: A third recess (111) is provided on the other inner side of the clamping groove (11), and a second internal threaded hole (112) and a limiting portion (113) are provided on the third recess (111) of the clamping groove. The flushing pressure plate (6) is provided on the third recess (111) of the clamping groove, and a flushing pressure plate boss (61) and a limiting matching portion (62) are provided on the flushing pressure plate boss (61), and the flushing pressure plate boss (61) is located on the second internal threaded hole (112), and the limiting matching portion (62) cooperates with the limiting portion (113). A flushing adjustment external thread (71) is provided on the flushing adjustment member (7), and the flushing adjustment external thread (71) cooperates with the second internal threaded hole (112). The inner side surface of the flushing adjustment member (7) is drivingly connected to the flushing pressure plate boss (61), and the outer side surface is provided with an adjusting action portion (72).

10. A caliper, characterized in that: A measuring accessory (X) for measuring the size of a recessed hole according to any one of claims 1 to 9, wherein the caliper comprises a main scale (100) and a vernier (200), a first caliper arm (101) is provided at the zero scale end of the main scale (100), a second caliper arm (201) is provided at the zero scale end of the vernier (200), and the first caliper arm (101) and the second caliper arm (201) are symmetrical with each other; The measuring accessory (X) is provided with one and is assembled and disassembled on the first caliper arm (101) or the second caliper arm (201) through the cooperation of the clamping groove (11) and the elastic assembly; or, the measuring accessory (X) is provided with two, the two measuring accessories (X) are symmetrically facing each other and are assembled and disassembled on the first caliper arm (101) and the second caliper arm (201) respectively through the cooperation of the clamping groove (11) and the elastic assembly.

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