CN211147538U

CN211147538U - Ball axial clearance detects and positioning fixture frock in bullet head type nib

Info

Publication number: CN211147538U
Application number: CN201922382082.1U
Authority: CN
Inventors: 武建勇; 牛锁堂; 李峰; 悦艳红; 高洋洋; 秦清昆
Original assignee: Shanxi Dazhong Ruihao Technology Co ltd
Current assignee: Shanxi Dazhong Ruihao Technology Co ltd
Priority date: 2019-12-26
Filing date: 2019-12-26
Publication date: 2020-07-31
Anticipated expiration: 2029-12-26

Abstract

The utility model discloses a tool for detecting and positioning the axial clearance of a ball in a bullet-shaped pen head, which comprises an axial clearance detecting tool (100) and a pen head positioning fixture (200); axial gap detects frock (100) and includes base (101), and base (101) middle part is equipped with installation baffle (102), and it is amesdial place the platform (103) to lie in installation baffle (102) one side on base (101), lie in installation baffle (102) opposite side and be anchor clamps platform (104), and installation baffle (102) middle part is equipped with installation seam (105) in advance, and it has the mounting hole to open on installation baffle (102), and installation seam (105) transversely run through the mounting hole, place digital display amesdial (111) on amesdial place the platform (103), and outer pole (112) of digital display amesdial (111) pass the mounting hole. The utility model relates to a rationally, fine practical application is worth having.

Description

Ball axial clearance detects and positioning fixture frock in bullet head type nib

Technical Field

The utility model relates to a bullet head type nib detects frock specifically is a ball axle clearance detects and positioning fixture frock in bullet head type nib, is applicable to the detection of bullet head type gel ink pen head parameter.

Background

The 24-station machine is a special machine for processing the neutral pen point, and the working principle is as follows: the blank is sucked into the equipment by a particle through the vibrating disk, then flows into a finished product box through the discharge pipe after 24 processing procedures (including the procedures of external turning, internal drilling, bead filling, closing, hammering and the like). Whether one pen head is processed to be qualified or not needs to detect various parameters of the pen head, and professional instruments including a microscope, a dynamometer (digital display dial indicator) and the like are also needed for detecting the parameters; in order to ensure that the processed pen point is installed on the pen core and then writing is smooth and continuous, the ball is not blocked or dead in the ball seat body, and ink is discharged uniformly. Therefore, the quality is strictly controlled in the processing process of the pen point, the assembly diameter, the inner diameter and the wall thickness of the bowl opening, the dew size, the size of the ball socket, the ejection force, the gap of the ball socket and other parameters of the pen point are detected according to the standard requirement, and the main parameters are finely adjusted according to the matching of the ink condition, so that the ink output of hundreds of meters required by a client is achieved; the detection of the axial gap size of the ball in the ball seat body is particularly important, the detection directly influences the quality of the pen point, if the gap is zero, the phenomena of ball death and ball clamping can be caused, ink cannot be discharged, and if the gap is too large, the ink discharge amount is easy to be large. However, the tight frock of location clamp to bullet head type nib at present hardly has, because the individual nothing of neutral pen head, loses easily, is difficult for fixing, leads to certain puzzlement for its detection, consequently this application design this frock is exactly for more accurate, efficient detection out multiple parameters such as axial clearance size, makes things convenient for workman's operation.

Disclosure of Invention

To the assembly diameter, bowl mouth internal diameter and wall thickness, dew size, ball socket size, multiple parameters such as axial clearance that want the accurate detection go out the nib, should guarantee under the condition that does not harm the nib, the utility model aims at designing a special frock good back reuse professional instrument of nib and detecting it.

The utility model discloses an adopt two kinds of technical scheme as follows to realize:

a tool for detecting and positioning axial clearance of a ball in a bullet-shaped pen point comprises an axial clearance detecting tool and a pen point positioning clamp.

The axial clearance detection tool comprises a base, wherein an installation partition plate is arranged in the middle of the base, a dial indicator placing platform is arranged on one side, located on the installation partition plate, of the base, a fixture platform is arranged on the other side, located on the installation partition plate, an installation seam is pre-arranged in the middle of the installation partition plate, an installation hole is formed in the installation partition plate, the installation seam transversely penetrates through the installation hole, a digital display dial indicator is placed on the dial indicator placing platform, an outer rod of the digital display dial indicator penetrates through the installation hole, a locking screw is arranged on the installation partition plate in a threaded mode, the locking screw is located on one side of the installation hole, and after the locking screw is screwed, the installation seam is compressed, so; the improved pen point clamp is characterized in that a clamping seat is arranged on the clamp platform, a hinge pressing plate is installed on the clamping seat, pen point placing grooves are correspondingly formed in the surface of the clamping seat and the back face of the hinge pressing plate, and after a pen point is horizontally placed in each pen point placing groove, the pen point portion of the pen point is right opposite to the measuring rod center of the digital display dial indicator.

The pen point positioning clamp comprises a fixed seat, a core rod, a cap body and a spring; a step through hole is axially formed in the center of the fixing seat, and a V-shaped clamping groove is formed in the small hole end, located in the step through hole, of the fixing seat; the core rod comprises a rod body and a clamping cap, wherein the clamping cap is integrally arranged at one end of the rod body, and threads are arranged at the other end of the rod body; the spring is placed from the large hole end of the fixing seat, the core rod penetrates through the small hole end of the fixing seat, the cap body is inserted into the large hole end of the fixing seat and is in threaded connection with the core rod to compress the spring, and the pen point is positioned and clamped in the V-shaped clamping groove by the clamping cap of the core rod.

To the axial clearance detection frock, during the assembly, the digital display amesdial is placed on the amesdial place the platform on the base, passes the mounting hole at installation baffle middle part with the outer pole of digital display amesdial, then is located the measuring staff of outer pole and has passed the installation baffle. And then the locking screw is screwed down, and the outer rod of the digital display dial indicator is fixed in the mounting hole by extruding the mounting seam, so that the digital display dial indicator is fixed. The other side of the middle mounting baffle plate of the base is provided with a clamp platform, and a clamping seat which is convenient to operate and can fix the pen point is arranged on the clamp platform. During the measurement, put the nib on the nib standing groove on holder surface, notice the nib front end at this moment will bulldoze behind the measuring staff certain stroke of digital display amesdial and will press the digital display amesdial to return to zero, then manual upset hinge clamp plate, compress tightly the nib with the nib standing groove at the hinge clamp plate back, insert the inside ball department of nib with the stylus by the nib hole of nib afterbody, lightly push away the ball and do axial motion and observe the reading of amesdial numerical value, this numerical value is exactly the axial clearance value of the ball in the nib.

For the pen point positioning clamp, under the normal state, the clamping cap of the core rod is abutted against the fixed seat under the action of the spring. When the pen is used, the pen point is clamped in the V-shaped clamping groove of the fixing seat, the cap body is pushed and pressed firstly, the clamping cap of the core rod is separated from the fixing seat, then the pen point is vertically placed in the V-shaped clamping groove of the fixing seat, the tail part of the pen point is supported on the rod body of the core rod, the pen point is clamped by the pressure of the spring through the reciprocating motion of the core rod, and the clamping force is adjustable according to the pressure of the spring. Therefore, the pen point can be firmly fixed on the tool according to the condition, the pen point of the pen point faces upwards, and after the pen point is fixed, various parameters such as the assembly diameter, the inner diameter and the wall thickness of the bowl opening, the dew size, the ball socket size and the like of the pen point are detected by a professional instrument.

And the tool comprises an axial clearance detection tool and a pen point positioning clamp.

The axial clearance detection tool comprises a base, wherein an installation partition plate is arranged in the middle of the base, a dial indicator placing platform is arranged on one side, located on the installation partition plate, of the base, a fixture platform is arranged on the other side, located on the installation partition plate, an installation seam is pre-arranged in the middle of the installation partition plate, an installation hole is formed in the installation partition plate, the installation seam transversely penetrates through the installation hole, a digital display dial indicator is placed on the dial indicator placing platform, an outer rod of the digital display dial indicator penetrates through the installation hole, a locking screw is arranged on the installation partition plate in a threaded mode, the locking screw is located on one side of the installation hole, and after the locking screw is screwed, the installation seam is compressed, so; and a transverse mounting groove is formed in the clamp platform.

The pen point positioning clamp comprises a fixed seat, a core rod, a cap body and a spring; a step through hole is axially formed in the center of the fixing seat, and a V-shaped clamping groove is formed in the small hole end, located in the step through hole, of the fixing seat; the core rod comprises a rod body and a clamping cap, wherein the clamping cap is integrally arranged at one end of the rod body, and threads are arranged at the other end of the rod body; the spring is placed from the large hole end of the fixing seat, the core rod penetrates through the small hole end of the fixing seat, the cap body is inserted into the large hole end of the fixing seat and is in threaded connection with the core rod to compress the spring, the pen point is positioned and clamped in the V-shaped clamping groove by the clamping cap of the core rod, a through hole is formed in the connection position of the rod body of the core rod and the clamping cap, and when the pen point is clamped by the clamping cap, the through hole is opposite to the pen point hole.

After the pen point positioning clamp is installed in the transverse installation groove in a sliding mode, the pen point portion of the pen point is opposite to the center of the measuring rod of the digital display dial indicator.

Similarly, for the axial clearance detection tool, during assembly, the digital display dial indicator is placed on the dial indicator placing platform on the base, the outer rod of the digital display dial indicator penetrates through the mounting hole in the middle of the mounting partition plate, and the measuring rod in the outer rod penetrates through the mounting partition plate; and then the locking screw is screwed down, and the outer rod of the digital display dial indicator is fixed in the mounting hole by extruding the mounting seam, so that the digital display dial indicator is fixed. The other side of the middle installation clapboard of the base is provided with a clamp platform, and the clamp platform is provided with a transverse installation groove which is convenient to operate. For the pen point positioning clamp, under the action of a spring, the clamping cap of the core rod is abutted against the fixed seat in a normal state; when the pen is used, the pen point is clamped in the V-shaped clamping groove of the fixing seat, the cap body is pushed and pressed firstly, the clamping cap of the core rod is separated from the fixing seat, then the pen point is vertically placed in the V-shaped clamping groove of the fixing seat, the tail part of the pen point is supported on the rod body of the core rod, the pen point is clamped by the pressure of the spring through the reciprocating motion of the core rod, the clamping force is adjustable according to the pressure of the spring, the pen point can be firmly fixed on a tool according to the condition, and the pen point of the pen point faces.

During measurement, a pen point positioning fixture is installed in a transverse installation groove of the axial clearance detection tool in a sliding mode, the pen point portion of the pen point is right opposite to the measuring rod center of the digital display dial indicator, the front end of the pen point is noticed to push and press the measuring rod of the digital display dial indicator for a certain stroke and then return the digital display dial indicator to zero, then the measuring needle penetrates through a through hole of the rod body, the ball is slightly pushed at the ball point position inside the pen point to move axially through a pen point hole in the tail portion of the pen point, and the numerical value is the axial clearance value of the ball in the pen point. Then, the pen point positioning clamp is taken down, and a professional instrument is used for detecting various parameters of the pen point, such as the assembly diameter, the inner diameter and the wall thickness of the bowl opening, the dew size, the ball socket size and the like.

The utility model relates to a rationally, fine practical application is worth having.

Drawings

Fig. 1 shows a schematic view of an axial clearance inspection tool.

FIG. 2 is a schematic view of the outer appearance of the pen tip positioning fixture.

FIG. 3 is a schematic cross-sectional view of the pen tip positioning fixture.

Fig. 3a shows a schematic cross-sectional view of the outer casing.

Figure 3b shows a schematic cross-sectional view of the core rod.

Figure 3c shows a schematic cross-sectional view of the cap.

FIG. 4 shows an assembly diagram of the axial clearance detection tool and the pen point positioning fixture.

Fig. 5 shows a schematic view of a bullet-nose type cartridge.

In the figure: 100-axial clearance detection tool, 101-base, 102-installation partition plate, 103-dial indicator placement platform, 104-clamp platform, 105-installation gap, 106-locking screw, 107-clamp seat, 108-hinge pressure plate, 109-pen point placement groove, 110-transverse installation groove, 111-digital display dial indicator, 112-external rod and 113-measuring rod; 200-pen point positioning clamp, 201-fixing seat, 202-step through hole, 203-V-shaped clamping groove, 204-core rod, 205-rod body, 206-clamping cap, 207-through hole, 208-cap body and 209-spring; 300-pen point.

Detailed Description

The following describes in detail specific embodiments of the present invention with reference to the accompanying drawings.

Example 1

A tool for detecting and positioning axial clearance of a ball in a bullet-shaped pen point comprises an axial clearance detecting tool 100 and a pen point positioning fixture 200.

As shown in fig. 1, the axial clearance detecting tool 100 includes a base 101, a mounting partition plate 102 is arranged in the middle of the base 101, a dial indicator placing platform 103 is arranged on one side of the mounting partition plate 102 on the base 101, a fixture platform 104 is arranged on the other side of the mounting partition plate 102, a mounting seam 105 is arranged in the middle of the mounting partition plate 102 in advance, a mounting hole is formed in the mounting partition plate 102, the mounting seam 105 transversely penetrates through the mounting hole, a digital display dial indicator 111 is placed on the dial indicator placing platform 103, an outer rod 112 of the digital display dial indicator 111 penetrates through the mounting hole (not shown in the mounting hole diagram), a locking screw 106 is installed on the mounting partition plate 102 in a threaded manner, the locking screw 106 is arranged on one side of the mounting hole, and the mounting seam 105 is compressed after being. The clamp platform 104 is provided with a clamp seat 107, the clamp seat 107 is provided with a hinge pressing plate 108, the surface of the clamp seat 107 and the back surface of the hinge pressing plate 108 are correspondingly provided with a pen point placing groove 109, and after the pen point 300 is horizontally placed in the pen point placing groove 109, the pen point part of the pen point 300 is opposite to the center of the measuring rod 113 of the digital display dial indicator 111.

The tool is characterized in that a digital dial indicator is fixed on a base, a digital dial indicator 111 is placed on a dial indicator placing platform 103 on the base 101, an outer rod 112 of the digital dial indicator 111 penetrates through a mounting hole in the middle of a mounting partition plate 102, and a measuring rod 113 located in the outer rod 112 penetrates through the mounting partition plate 102. Then, the locking screw 106 is tightened (the mounting slit 105 is squeezed), and the outer rod 112 of the digital display dial indicator 111 is fixed in the mounting hole, so that the digital display dial indicator is fixed. The other side of the partition plate 102 is provided with a clamp platform 104 at the middle part of the base 101, and a clamp seat 107 which is convenient to operate and can fix the pen point is arranged on the clamp platform 104.

During measurement, the pen point 300 is placed on the pen point placing groove 109 on the surface of the clamping seat 107, the front end of the pen point 300 is noticed to push and press the measuring rod 113 of the digital display dial indicator 111 for a certain stroke and return the digital display dial indicator to zero, then the hinge pressing plate 108 is manually turned, the pen point 300 is pressed by the pen point placing groove 109 on the back of the hinge pressing plate 108, the measuring needle is inserted into the ball point inside the pen point from the pen point hole at the tail of the pen point 300 to slightly push the ball point to perform axial movement, and the numerical value of the dial indicator is observed, and the numerical value is the axial clearance value of the ball point inside the pen point. The tool is convenient and accurate to operate.

As shown in fig. 2 and 3, the pen point positioning fixture 200 includes a fixing base 201, a core rod 204, a cap 208 and a spring 209. As shown in FIG. 3a, a stepped through hole 202 is axially formed in the center of the fixing seat 201, a large hole end is used for installing a cap body 208 and a spring 209, and a small hole channel is used for inserting a core rod 204. The small hole end of the fixed seat 201, which is positioned at the step through hole 202, is provided with a V-shaped clamping groove 203. As shown in fig. 3b, the stem 204 comprises a rod 205 and a clamp cap 206, wherein the clamp cap 206 is integrally disposed at one end of the rod 205, and the other end of the rod is threaded for connecting with a cap 208. As shown in fig. 3, the cap 208 has an internal thread on one side that mates with the other end of the rod 205.

As shown in fig. 3, the spring 209 is inserted from the large hole end of the fixing base 201, the core rod 204 is inserted from the small hole end of the fixing base 201, the cap 208 is inserted from the large hole end of the fixing base 201 and is in threaded connection with the core rod 204 to compress the spring 209, and the clip cap 206 of the core rod 204 positions and clamps the pen point 300 in the V-shaped clip groove 203.

Because the big end hole of the fixed seat 201 is provided with the spring 209, under the action of the spring 209, the clamping cap 206 of the core rod 204 is abutted against the fixed seat 201 in a normal state. When the special positioning fixture tool is used, the pen point 300 is clamped in the V-shaped clamping groove 203 of the fixing seat 201, the cap body 208 is pushed firstly, the clamping cap 206 of the core rod 204 is separated from the fixing seat 201, then the pen point 300 is vertically placed in the V-shaped clamping groove 203 of the fixing seat 201, the tail part of the pen point 300 is supported on the rod body 205 of the core rod 204, the pen point 300 is clamped by the reciprocating motion of the core rod 204 through the pressure of the spring 209, the clamping force is adjustable according to the pressure of the spring, and the threaded connection distance between the cap body 208 and the core rod 204 is adjusted, namely the pressure of the spring can be adjusted. Therefore, the pen point can be firmly fixed on the tool according to the situation, the pen point of the pen point 300 faces upwards, and the requirements of detecting other parameters, such as the inner diameter and the wall thickness of the bowl mouth, the exposed bead size and the ball socket size, can be met accurately under a microscope. The tool is light, small in size, practical and very convenient to use.

Example 2

As shown in fig. 4, the axial gap detection tool 100 includes a base 101, a mounting partition plate 102 is arranged in the middle of the base 101, a dial indicator placing platform 103 is arranged on one side of the mounting partition plate 102 on the base 101, a fixture platform 104 is arranged on the other side of the mounting partition plate 102, a mounting seam 105 is pre-arranged in the middle of the mounting partition plate 102, a mounting hole is formed in the mounting partition plate 102, the mounting seam 105 transversely penetrates through the mounting hole, a digital display dial indicator 111 is placed on the dial indicator placing platform 103, an outer rod 112 of the digital display dial indicator 111 penetrates through the mounting hole, a locking screw 106 is threadedly mounted on the mounting partition plate 102, the locking screw 106 is arranged on one side of the mounting hole, and after being screwed, the mounting seam 105 is compressed so; the clamp platform 104 is provided with a transverse mounting slot 110.

The pen point positioning fixture 200 comprises a fixed seat 201, a core rod 204, a cap body 208 and a spring 209; a step through hole 202 is axially formed in the center of the fixing seat 201, and a V-shaped clamping groove 203 is formed in the small hole end, located on the step through hole 202, of the fixing seat 201; the core rod 204 comprises a rod body 205 and a clamping cap 206, wherein one end of the rod body 205 is integrally provided with the clamping cap 206, and the other end of the rod body is provided with threads; the spring 209 is put in from the big hole end of the fixing seat 201, the core rod 204 is penetrated through from the small hole end of the fixing seat 201, the cap body 208 is inserted into the big hole end of the fixing seat 201 and is in threaded connection with the core rod 204 to compress the spring 209, the pen point 300 is positioned and clamped in the V-shaped clamping groove 203 by the clamping cap 206 of the core rod 204, a through hole 207 is formed at the connection part of the rod body 205 of the core rod 204 and the clamping cap 206 (as shown in fig. 3b, when the through hole 207 is used for detecting the axial movement clearance of the ball inside the pen point, the measuring pin penetrates through the through hole), and when the pen point 300 is clamped.

As shown in FIG. 4, after the pen point positioning fixture 200 is slidably mounted in the transverse mounting groove 110, the pen point portion of the pen point 300 is opposite to the center of the measuring rod 113 of the digital dial indicator 111.

It can be seen that, in embodiment 1, the axial gap detection tool 100 and the nib positioning fixture 200 are used independently, in embodiment 2, the axial gap detection tool 100 and the nib positioning fixture 200 are used in cooperation, the axial gap detection tool 100 does not need to be additionally provided with the clamping seat 107 and the hinge pressing plate 108, and the nib positioning fixture 200 is used to clamp the nib and then assembled to the axial gap detection tool 100 for axial detection. The difference between the pen tip positioning jig 200 of embodiments 1 and 2 is that in embodiment 2, a through hole 207 is formed at the joint of the rod 205 and the clamp cap 206 of the core rod 204. When the tool is used, after the pen point 300 is clamped by the pen point positioning fixture 200, the pen point positioning fixture 200 is installed in the transverse installation groove 110 of the axial clearance detection tool 100 in a sliding mode, the pen point portion of the pen point 300 is opposite to the center of the measuring rod 113 of the digital display dial indicator 111, attention is paid to the fact that the front end of the pen point 300 pushes the measuring rod 113 of the digital display dial indicator 111 for a certain stroke and then the digital display dial indicator is reset to zero, then the measuring needle penetrates through the through hole 207 of the rod body 205, the pen point hole at the tail portion of the pen point 300 is inserted into the ball point inside the pen point 300, the ball is pushed slightly to move axially, the reading of the numerical value of the dial indicator is observed.

Then, the pen point positioning jig 200 is removed, the pen point of the pen point 300 is upward, and the inner diameter and the wall thickness of the bowl mouth, the dew size and the ball socket size are accurately measured by a microscope.

The above description is only a preferred example of the present invention and should not be taken as limiting the invention, and any modification, equivalent replacement or improvement that is within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a ball axle clearance detects and positioning fixture frock in bullet head type nib which characterized in that: the tool comprises an axial clearance detection tool (100) and a pen point positioning clamp (200);

the axial clearance detection tool (100) comprises a base (101), a mounting clapboard (102) is arranged in the middle of the base (101), a dial indicator placing platform (103) is arranged on one side of the base (101) positioned on the installation clapboard (102), a clamp platform (104) is arranged on the other side of the installation clapboard (102), the middle part of the installation clapboard (102) is provided with an installation slit (105) in advance, the installation clapboard (102) is provided with an installation hole, the mounting seam (105) transversely penetrates through the mounting hole, a digital dial indicator (111) is arranged on the dial indicator placing platform (103), an outer rod (112) of the digital dial indicator (111) penetrates through the mounting hole, a locking screw (106) is installed on the mounting partition plate (102) in a threaded mode, the locking screw (106) is positioned on one side of the mounting hole, and after the locking screw is screwed, the mounting seam (105) is compressed, so that the outer rod (112) of the digital dial indicator (111) is fixed in the mounting hole; the clamp platform (104) is provided with a clamp seat (107), a hinge pressing plate (108) is installed on the clamp seat (107), pen point placing grooves (109) are correspondingly formed in the surface of the clamp seat (107) and the back face of the hinge pressing plate (108), and after the pen point (300) is horizontally placed in the pen point placing grooves (109), the pen point part of the pen point (300) is opposite to the center of a measuring rod (113) of the digital display dial indicator (111);

the pen point positioning clamp (200) comprises a fixed seat (201), a core rod (204), a cap body (208) and a spring (209); a step through hole (202) is axially formed in the center of the fixed seat (201), and a V-shaped clamping groove (203) is formed in the small hole end, located on the step through hole (202), of the fixed seat (201); the core rod (204) comprises a rod body (205) and a clamping cap (206), wherein the clamping cap (206) is integrally arranged at one end of the rod body (205), and threads are arranged at the other end of the rod body; the spring (209) is placed in from the big hole end of the fixing seat (201), the core rod (204) penetrates through from the small hole end of the fixing seat (201), the cap body (208) is inserted into the big hole end of the fixing seat (201) and is in threaded connection with the core rod (204) to compress the spring (209), and the clamping cap (206) of the core rod (204) positions and clamps the pen point (300) in the V-shaped clamping groove (203).

2. The utility model provides a ball axle clearance detects and positioning fixture frock in bullet head type nib which characterized in that: the tool comprises an axial clearance detection tool (100) and a pen point positioning clamp (200);

the axial clearance detection tool (100) comprises a base (101), a mounting clapboard (102) is arranged in the middle of the base (101), a dial indicator placing platform (103) is arranged on one side of the base (101) positioned on the installation clapboard (102), a clamp platform (104) is arranged on the other side of the installation clapboard (102), the middle part of the installation clapboard (102) is provided with an installation slit (105) in advance, the installation clapboard (102) is provided with an installation hole, the mounting seam (105) transversely penetrates through the mounting hole, a digital dial indicator (111) is arranged on the dial indicator placing platform (103), an outer rod (112) of the digital dial indicator (111) penetrates through the mounting hole, a locking screw (106) is installed on the mounting partition plate (102) in a threaded mode, the locking screw (106) is positioned on one side of the mounting hole, and after the locking screw is screwed, the mounting seam (105) is compressed, so that the outer rod (112) of the digital dial indicator (111) is fixed in the mounting hole; a transverse mounting groove (110) is formed in the clamp platform (104);

the pen point positioning clamp (200) comprises a fixed seat (201), a core rod (204), a cap body (208) and a spring (209); a step through hole (202) is axially formed in the center of the fixed seat (201), and a V-shaped clamping groove (203) is formed in the small hole end, located on the step through hole (202), of the fixed seat (201); the core rod (204) comprises a rod body (205) and a clamping cap (206), wherein the clamping cap (206) is integrally arranged at one end of the rod body (205), and threads are arranged at the other end of the rod body; the spring (209) is placed in from the large hole end of the fixing seat (201), the core rod (204) penetrates from the small hole end of the fixing seat (201), the cap body (208) is inserted into the large hole end of the fixing seat (201) and is in threaded connection with the core rod (204) to compress the spring (209), the pen point (300) is positioned and clamped in the V-shaped clamping groove (203) by the clamping cap (206) of the core rod (204), a through hole (207) is formed in the connection position of the rod body (205) of the core rod (204) and the clamping cap (206), and when the pen point (300) is clamped by the clamping cap (206), the through hole (207) is opposite to the pen point hole;

after the pen point positioning clamp (200) is installed in the transverse installation groove (110) in a sliding mode, the pen point portion of the pen point (300) is opposite to the center of the measuring rod (113) of the digital display dial indicator (111).