Measuring tool for measuring axial dimension of inner hole

Abstract

The invention belongs to the technical field of measuring tools, and particularly discloses a measuring tool for measuring the axial dimension of an inner hole, and the measuring tool comprises a main ruler which is of a cuboid structure as a whole, the front side surface of the main ruler is provided with scale marks, and the bottom of the left side section of the main ruler is fixedly provided with a left clamping tooth; the auxiliary ruler is slidably installed in a sliding groove in the back of the main ruler, a right clamping tooth is fixed to the bottom of the left side section of the auxiliary ruler, and the right side section of the main ruler limits the auxiliary ruler through a limiting plate; the guide pin is installed on the front side face of the auxiliary ruler and used for sliding in the guide groove of the main ruler. The sliding block moves downwards in the inner frame by pulling the header, the clamping teeth can be conveniently and correspondingly clamped in the clamping grooves in different positions under the elastic force of the first elastic piece, the distance between the header and the bottom face of the left clamping tooth and / or the bottom face of the right clamping tooth can be adjusted, and the header can conveniently measure the axial sizes of different depths of an inner hole of a part.

Description

Technical Field

[0001] This invention belongs to the field of measuring instrument technology, and specifically relates to a measuring instrument for measuring the axial dimension of an inner hole. Background Technology

[0002] Inspection technology is an important means of ensuring the quality of mechanical products, and the dimensional accuracy of parts is an important indicator of the quality of mechanical products.

[0003] In the machining process of mechanical products, the cleats of measuring tools such as inside diameter gauges, inside micrometers or vernier calipers are usually used to measure the inner diameter of the workpiece. However, when measuring the inner diameter of some deep inner holes with intermediate shafts or bosses, cleats that are too short cannot be used.

[0004] Therefore, it is necessary to invent a measuring tool for measuring the axial dimension of an inner hole to solve the above problems. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a measuring tool for measuring the axial dimension of an inner hole, thereby resolving the issues raised in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a measuring tool for measuring the axial dimension of an inner hole, comprising: a main scale, wherein the main scale is configured as a cuboid structure, the front side of the main scale is provided with scale lines, and a left chuck is fixed to the bottom of the left side section of the main scale; a secondary scale, wherein the secondary scale is slidably installed inside a groove on the back of the main scale, a right chuck is fixed to the bottom of the left side section of the secondary scale, and the right side section of the main scale is limited by a limiting plate; a guide pin, installed on the front side of the secondary scale, for sliding inside a guide groove of the main scale; and a scale, installed on the front side of the secondary scale by multiple screws, wherein the rear side of the scale is attached to the front side of the main scale, and the front side of the scale is provided with scale lines for measuring the axial dimension of the inner hole.

[0007] Furthermore, the left and right locking teeth are identical in shape and are positioned opposite each other. When the scale line of the main scale corresponds to the scale line of the ruler, the right side of the left locking tooth and the left side of the right locking tooth fit together tightly.

[0008] Furthermore, the left locking tooth includes: a first locking plate and a second locking plate; the first locking plate and the second locking plate are arranged opposite to each other, and the inner sides of the first locking plate and the second locking plate are provided with an inner frame. A slider is provided inside the inner frame, and the bottom surface of the slider is connected to a pointer head by a connecting rod. The outer end of the pointer head is flush with the outer side of the left locking tooth.

[0009] Furthermore, an outer frame is provided on the outside of the inner frame. The outer frame is fixedly connected to the slider. The outer frame slides and fits on the outside of the inner frame. The two opposite outer frames are connected by a sleeve. A vertical rod is inserted vertically inside the sleeve. The top of the vertical rod inside the left clamp is connected to the bottom surface of the main scale, and the top of the vertical rod inside the right clamp is connected to the bottom surface of the secondary scale.

[0010] Furthermore, the slider is provided with a limiting component, which includes: a sleeve installed on the inner side of the outer frame, and the outer frame is connected to the sleeve via the sleeve; an insert rod movably inserted into the sleeve, and the inner end of the insert rod is fixed with a locking tooth; and a first elastic element installed inside the slider for driving the inner end of the insert rod to press against the vertical rod.

[0011] Furthermore, a baffle is fixed to the top of the insertion rod, and a limiting groove corresponding to the baffle is opened on the top surface of the slider. The elastic force of the first elastic element causes the baffle to slide inside the limiting groove.

[0012] Furthermore, the surface of the vertical rod is provided with multiple slots, and the locking teeth at the inner end of the insertion rod correspond to and engage with the slots.

[0013] Furthermore, a protruding plate is fixed to the side of the outer frame, and a side edge is fixed to the inner sidewall of the first and second clamping plates. A clamping component for limiting the protruding plate is provided on the side edge. The clamping component includes: an arc-shaped plate, two arc-shaped plates are arranged opposite each other and clamp the end of the protruding plate; a sliding frame is fixedly installed on the top of the arc-shaped plate; a positioning rod is fixedly installed on the inner sidewall of the side edge, and the sliding frame is slidably sleeved on the surface of the positioning rod; and a second elastic element is installed inside the sliding frame for driving the two arc-shaped plates to move closer to each other.

[0014] Furthermore, a crossbar is fixed to the surface of the positioning rod, which passes through the slide frame, and the moving slide frame slides on the surface of the crossbar.

[0015] Furthermore, an arc-shaped piece is provided at the bottom of the arc-shaped plate, and the upward-moving convex plate slides between the two arc-shaped plates using the arc-shaped piece.

[0016] The technical effects and advantages of this invention are as follows: 1. This invention allows the slider to move downward inside the inner frame by pulling the pointer. Under the elastic force of the first elastic element, the corresponding clips of the teeth are conveniently located in the slots at different positions. This allows the distance between the pointer and the bottom surface of the left and / or right clips to be adjusted, making it convenient for the pointer to measure the axial dimensions of the inner hole of the part at different depths.

[0017] 2. The present invention uses the elastic force of the second elastic element to make the two arc-shaped plates cooperate to clamp the end of the convex plate, which facilitates the limiting of the label head and avoids the label head from moving directly away from the left and / or right clamping teeth due to simple pulling, thus ensuring the stability of the label head at the bottom of the left and / or right clamping teeth. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall measuring tool for measuring the axial dimension of an inner hole according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the back structure of the main ruler according to an embodiment of the present invention; Figure 3This is a schematic diagram of the connection between the vernier scale and the standard scale according to an embodiment of the present invention; Figure 4 This is a three-dimensional schematic diagram of the left retainer tooth according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the slider connection outer frame according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the ends of the two arc-shaped plates clamping the convex plate in an embodiment of the present invention; In the diagram: 1. Main scale; 101. Left locking tooth; 102. Slide groove; 103. Guide groove; 2. Secondary scale; 201. Right locking tooth; 3. Guide pin; 4. Scale; 5. First locking plate; 6. Second locking plate; 7. Inner frame; 8. Slider; 801. Limiting groove; 9. Marker head; 10. Outer frame; 11. Sleeve; 12. Vertical rod; 13. Sleeve tube; 14. Insert rod; 141. Locking tooth; 15. First elastic element; 16. Baffle; 17. Locking groove; 18. Protruding plate; 19. Side; 20. Arc plate; 21. Slide frame; 22. Positioning rod; 23. Second elastic element; 24. Horizontal bar; 25. Arc plate. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0020] This invention provides a measuring tool for measuring the axial dimension of an inner hole, such as... Figures 1 to 3 As shown, it includes: a main scale 1, a secondary scale 2, a guide pin 3, and a scale 4; the main scale 1 is set as a cuboid structure, with scale lines on the front side of the main scale 1, and a slide groove 102 on the back of the main scale 1. The secondary scale 2 is slidably engaged inside the slide groove 102. The secondary scale 2 is limited by a limiting plate on the right side of the main scale 1. The scale 4 is fixed to the front side of the secondary scale 2 by multiple screws. The scale lines are set on the front side of the scale 4, and the 0 scale line of the main scale 1 corresponds to the 0 scale line of the scale 4.

[0021] A guide pin 3 is spirally mounted on the left side of the front side of the auxiliary scale 2, and a guide groove 103 corresponding to the guide pin 3 is opened on the surface of the main scale 1. The moving auxiliary scale 2 causes the guide pin 3 to slide inside the guide groove 103. A left locking tooth 101 is fixed to the bottom of the left side section of the main scale 1, and a right locking tooth 201 is fixed to the bottom of the left side section of the auxiliary scale 2. The left locking tooth 101 and the right locking tooth 201 have the same shape and are arranged opposite to each other. When the 0 mark of the main scale 1 corresponds to the 0 mark of the scale 4, the right side of the left locking tooth 101 and the left side of the right locking tooth 201 fit tightly together.

[0022] Specifically, the auxiliary scale 2 is snapped into the groove 102 on the back of the main scale 1. At this time, the main scale 1 uses the limiting plate to limit the right side of the auxiliary scale 2. The guide pin 3 is then screwed onto the front side of the auxiliary scale 2 through the guide groove 103. The guide pin 3 and the guide groove 103 cooperate to limit the left side of the auxiliary scale 2. At this time, the 0 mark of the main scale 1 corresponds to the 0 mark of the scale 4, and the right side of the left locking tooth 101 and the left side of the right locking tooth 201 fit tightly together.

[0023] Place the part to be measured on the top surface of the workbench. Hold the measuring tool and insert the bottom ends of the left chuck 101 and right chuck 201 into the inner hole of the part. Push the vernier scale 2 to slide inside the slide groove 102. The moving vernier scale 2 causes the guide pin 3 to slide inside the guide groove 103. The moving vernier scale 2 drives the right chuck 201 away from the left chuck 101, and the vernier scale 2 causes the scale 4 to slide on the front side of the main scale 1 until the outer sides of the left chuck 101 and right chuck 201 are in contact with the inner wall of the inner hole of the part. At this time, according to the scale of the main scale 1 corresponding to the 0 mark of the scale 4, the preliminary length L can be obtained.

[0024] Since the left locking tooth 101 and the right locking tooth 201 are the same, we can know that the thickness of the left locking tooth 101 is X, and the axial dimension of the inner hole of the part is L+2X.

[0025] In this embodiment, the left clasp 101 and the right clasp 201 are separated by moving the auxiliary scale 2, and the scale 4 is aligned with the main scale 1 by sliding the guide pin 3 and the guide groove 103, which facilitates the rapid measurement of the axial dimension of the inner hole of the part to be measured.

[0026] To measure the axial dimension inside the bore of the part, the gauge head 9 is used for measurement. Figure 1 , Figure 4 and Figure 5 In the left clamp 101, there are: a first clamping plate 5 and a second clamping plate 6; the first clamping plate 5 and the second clamping plate 6 are arranged opposite each other, and the inner sides of the first clamping plate 5 and the second clamping plate 6 are provided with an inner frame 7. A slider 8 is provided inside the inner frame 7, and the bottom surface of the slider 8 is connected to a scale head 9 by a connecting rod. The connecting rod is vertically arranged, and the bottom end of the connecting rod passes through the bottom surface of the inner frame 7. The outer end of the scale head 9 is flush with the outer surface of the left clamp 101. An outer frame 10 is provided outside the inner frame 7. The outer frame 10 is fixedly connected to the slider 8. The outer frame 10 slides and fits on the outside of the inner frame 7. The two opposite outer frames 10 are connected by a sleeve 11. A vertical rod 12 is vertically inserted into the sleeve 11. The top end of the vertical rod 12 inside the left clamp 101 is connected to the bottom surface of the main scale 1, and the top end of the vertical rod 12 inside the right clamp 201 is connected to the bottom surface of the auxiliary scale 2.

[0027] Specifically, when the head 9 is pulled down, the connecting rod causes the slider 8 to move down inside the inner frame 7. The moving inner frame 7 causes the sleeve 11 to move down on the surface of the vertical rod 12 through the outer frame 10. The moving head 9 gradually moves away from the bottom surface of the left jaw 101.

[0028] Holding the measuring tool, insert the gauge head 9 at the bottom of the connecting rod into the inner hole of the part until the gauge head 9 is in the appropriate position. Then, move the guide pin 3 inside the guide groove 103. At this time, the auxiliary scale 2 causes the right clasp 201 to move away from the left clasp 101. The moving right clasp 201 causes the gauge head 9 to move. Since the outer end of the gauge head 9 is flush with the outer side of the left clasp 101, until the outer end of the gauge head 9 contacts the inner wall of the inner hole, the scale on the main scale 1 can be read through the 0 mark of the scale 4 to easily know the axial dimension inside the inner hole of the part to be measured.

[0029] In this embodiment, the depth to which the probe 9 penetrates into the inner hole of the part is adjusted by moving the slider 8 down inside the inner frame 7, so that the measuring tool can use the movable probe 9 to measure the axial dimension of the inner hole of the part at different depths.

[0030] To limit the header 9, a positioning slider 8 is used with a limiting component. Figure 4 and Figure 5 In the middle, the slider 8 is provided with a limiting component, which includes: sleeve 13, insert rod 14 and first elastic element 15. The first elastic element 15 is set as a spring. The sleeve 13 is fixed on the inner side of the outer frame 10, and the sleeve 11 is fixed on the inner end of the sleeve 13. At this time, the sleeve 11 is sleeved on the surface of the vertical rod 12. The insert rod 14 is inserted into the sleeve 13. The slider 8 is provided with an inner groove corresponding to the insert rod 14. The first elastic element 15 is located inside the inner groove. The top of the insert rod 14 is fixed with a baffle 16, and the top surface of the slider 8 is provided with a limiting groove 801 corresponding to the baffle 16. The elastic force of the first elastic element 15 causes the inner side of the baffle 16 to abut against the inner side wall of the limiting groove 801.

[0031] The vertical rod 12 has multiple slots 17 on its surface, and the inner end of the insertion rod 14 is fixed with a tooth 141 corresponding to the slot 17. The inner end of the insertion rod 14 is set as an arc-shaped surface, and the arc-shaped surface of the inner end of the insertion rod 14 is attached to the surface of the vertical rod 12.

[0032] Specifically, when the slider 8 moves downward inside the inner frame 7 by pulling the head 9, the downward slider 8 uses the sleeve 13 to make the sleeve 11 move downward on the surface of the vertical rod 12. Since the first elastic element 15's locking tooth 141 engages with the slot 17, the downward-moving sleeve 13 causes the insertion rod 14 to move downward. At this time, the bottom surface of the locking tooth 141 slides on the inner bottom surface of the slot 17. The sliding locking tooth 141 gradually moves out of the slot 17. At this time, the locking tooth 141 causes the insertion rod 14 to press the first elastic element 15 inside the inner groove, and the insertion rod 14 causes the baffle 16 to move away from the vertical rod 12.

[0033] When the lowered locking tooth 141 engages with the next locking slot 17, the elastic force of the first elastic element 15 causes the insertion rod 14 to approach the vertical rod 12 until the locking tooth 141 is engaged inside the locking slot 17. At this time, the inner side of the baffle 16 abuts against the inner side wall of the limiting groove 801.

[0034] In this embodiment, by pulling the pointer 9, the slider 8 moves down inside the inner frame 7. Under the elastic force of the first elastic element 15, the corresponding latch 141 can be adjusted to fit inside the slot 17 at different positions. This allows the pointer 9 to adjust the distance between the pointer 9 and the bottom surface of the left latch 101 and / or the right latch 201, making it convenient for the pointer 9 to measure the axial dimensions of the inner hole of the part at different depths.

[0035] To lock the head 9, the clamping component clamps the protrusion 18. Figures 4 to 6 In the middle, a protruding plate 18 is fixed on the side of the outer frame 10, and a side 19 is fixed on the inner side wall of the first clamping plate 5 and the second clamping plate 6. A clamping component is provided on the side 19 to limit the protruding plate 18. The clamping component includes: an arc plate 20, a sliding frame 21, a positioning rod 22, a second elastic element 23 and a crossbar 24. The second elastic element 23 is set as a spring sheet. The number of arc plates 20 is set to two, and the two arc plates 20 are arranged opposite to each other to clamp the end of the protruding plate 18. A sliding frame 21 is fixed at the top of each of the two arc plates 20, and the sliding frame 21 is slidably sleeved on the surface of the positioning rod 22. The positioning rod 22 is fixedly installed on the inner side wall of the side 19, and a crossbar 24 that penetrates the sliding frame 21 is fixed on the surface of the positioning rod 22. The moving sliding frame 21 slides on the surface of the crossbar 24.

[0036] Specifically, after measuring the axial dimension of the inner hole of the part to be measured using the gauge head 9, the gauge head 9 is pushed upward. The upward-moving gauge head 9 uses the connecting rod to make the slider 8 move upward inside the inner frame 7. The slider 8 uses the sleeve 13 to make the sleeve 11 move upward on the surface of the vertical rod 12. The upward-moving sleeve 13 makes the insert rod 14 move upward. At this time, the top surface of the clasp 141 slides on the top surface inside the slot 17. The sliding clasp 141 gradually moves out of the slot 17. At this time, the clasp 141 makes the insert rod 14 press against the first elastic element 15 inside the inner groove, and the insert rod 14 makes the baffle 16 move away from the vertical rod 12.

[0037] When the upward-moving locking tooth 141 engages with the previous locking slot 17, the elastic force of the first elastic element 15 causes the insertion rod 14 to approach the vertical rod 12 until the locking tooth 141 is engaged inside the locking slot 17. At this time, the inner side of the baffle 16 abuts against the inner side wall of the limiting groove 801. The continuously moving slider 8 uses the outer frame 10 to make the top of the convex plate 18 contact the arc-shaped piece 25 at the bottom of the arc-shaped plate 20. At this time, the upward-moving convex plate 18 uses the arc-shaped piece 25 to make the two arc-shaped plates 20 move away from each other. The arc-shaped plate 20 slides on the surface of the positioning rod 22 using the sliding frame 21, and the sliding frame 21 slides on the surface of the horizontal rod 24. At this time, the moving sliding frame 21 and the positioning rod 22 press the second elastic element 23 until the convex plate 18 moves up to between the two arc-shaped plates 20. The elastic force of the second elastic element 23 makes the two arc-shaped plates 20 move closer to each other until the two arc-shaped plates 20 cooperate to clamp the convex plate 18.

[0038] In this embodiment, the elastic force of the second elastic element 23 causes the two arc-shaped plates 20 to cooperate in clamping the end of the protrusion plate 18, which facilitates the limiting of the label head 9 and prevents the label head 9 from moving directly away from the left clamping tooth 101 and / or the right clamping tooth 201 due to simple pulling, thus ensuring the stability of the label head 9 at the bottom of the left clamping tooth 101 and / or the right clamping tooth 201.

[0039] Working principle of this invention: Reference Figures 1 to 6 As shown, the auxiliary ruler 2 is snapped into the groove 102 on the back of the main ruler 1. At this time, the main ruler 1 uses the limiting plate to limit the right side of the auxiliary ruler 2. The guide pin 3 is then screwed onto the front side of the auxiliary ruler 2 through the guide groove 103. The guide pin 3 and the guide groove 103 cooperate to limit the left side of the auxiliary ruler 2. At this time, the 0 mark of the main ruler 1 corresponds to the 0 mark of the scale 4, and the right side of the left locking tooth 101 and the left side of the right locking tooth 201 fit tightly together.

[0040] Place the part to be measured on the top surface of the workbench. Hold the measuring tool and insert the bottom ends of the left chuck 101 and right chuck 201 into the inner hole of the part. Push the vernier scale 2 to slide inside the slide groove 102. The moving vernier scale 2 causes the guide pin 3 to slide inside the guide groove 103. The moving vernier scale 2 drives the right chuck 201 away from the left chuck 101, and the vernier scale 2 causes the scale 4 to slide on the front side of the main scale 1 until the outer sides of the left chuck 101 and right chuck 201 are in contact with the inner wall of the inner hole of the part. At this time, according to the scale of the main scale 1 corresponding to the 0 mark of the scale 4, the preliminary length L can be obtained.

[0041] Since the left clamp 101 and the right clamp 201 are the same, we can know that the thickness of the left clamp 101 is X. At this time, the axial dimension of the inner hole of the part is L+2X, thus completing the measurement of the axial dimension of the inner hole.

[0042] In order to measure the axial dimension inside the inner hole of the part, the gauge head 9 is pulled. During the downward movement of the gauge head 9, the connecting rod causes the slider 8 to move down inside the inner frame 7. The downward movement of the inner frame 7 causes the sleeve 11 to move down on the surface of the vertical rod 12 through the outer frame 10. The downward movement of the gauge head 9 gradually moves away from the bottom surface of the left chuck 101.

[0043] When the slider 8 moves downward inside the inner frame 7 by pulling the head 9, the downward slider 8 uses the sleeve 13 to make the sleeve 11 move downward on the surface of the vertical rod 12. Since the first elastic element 15's locking tooth 141 is engaged with the slot 17, the downward sleeve 13 makes the insertion rod 14 move downward. At this time, the bottom surface of the locking tooth 141 slides on the inner bottom surface of the slot 17. The sliding locking tooth 141 gradually moves out of the slot 17. At this time, the locking tooth 141 makes the insertion rod 14 press the first elastic element 15 inside the inner groove, and the insertion rod 14 makes the baffle 16 move away from the vertical rod 12.

[0044] When the lowered locking tooth 141 engages with the next locking slot 17, the elastic force of the first elastic element 15 causes the insertion rod 14 to approach the vertical rod 12 until the locking tooth 141 is engaged inside the locking slot 17. At this time, the inner side of the baffle 16 abuts against the inner side wall of the limiting groove 801.

[0045] Holding the measuring tool, insert the gauge head 9 at the bottom of the connecting rod into the inner hole of the part until the gauge head 9 is in the appropriate position. Then, move the guide pin 3 inside the guide groove 103. At this time, the auxiliary scale 2 causes the right clasp 201 to move away from the left clasp 101. The moving right clasp 201 causes the gauge head 9 to move. Since the outer end of the gauge head 9 is flush with the outer side of the left clasp 101, until the outer end of the gauge head 9 contacts the inner wall of the inner hole, the scale on the main scale 1 can be read through the 0 mark of the scale 4 to easily know the axial dimension inside the inner hole of the part to be measured.

[0046] After measuring the axial dimension of the inner hole of the part to be measured using the gauge head 9, the gauge head 9 is pushed upward. The upward movement of the gauge head 9 causes the slider 8 to move upward inside the inner frame 7 via the connecting rod. The slider 8 causes the sleeve 11 to move upward on the surface of the vertical rod 12 via the sleeve 13. The upward movement of the sleeve 13 causes the insertion rod 14 to move upward. At this time, the top surface of the clasp 141 slides on the top surface inside the slot 17. The sliding clasp 141 gradually moves out of the slot 17. At this time, the clasp 141 causes the insertion rod 14 to press the first elastic element 15 inside the inner groove, and the insertion rod 14 causes the baffle 16 to move away from the vertical rod 12.

[0047] When the upward-moving locking tooth 141 engages with the previous locking slot 17, the elastic force of the first elastic element 15 causes the insertion rod 14 to approach the vertical rod 12 until the locking tooth 141 is engaged inside the locking slot 17. At this time, the inner side of the baffle 16 abuts against the inner side wall of the limiting groove 801. The continuously moving slider 8 uses the outer frame 10 to make the top of the convex plate 18 contact the arc-shaped piece 25 at the bottom of the arc-shaped plate 20. At this time, the upward-moving convex plate 18 uses the arc-shaped piece 25 to make the two arc-shaped plates 20 move away from each other. The arc-shaped plate 20 slides on the surface of the positioning rod 22 using the sliding frame 21, and the sliding frame 21 slides on the surface of the horizontal rod 24. At this time, the moving sliding frame 21 and the positioning rod 22 press the second elastic element 23 until the convex plate 18 moves up to between the two arc-shaped plates 20. The elastic force of the second elastic element 23 makes the two arc-shaped plates 20 move closer to each other until the two arc-shaped plates 20 cooperate to clamp the convex plate 18.

[0048] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

Claims

1. A gage for measuring the axial dimension of an internal bore, characterized in that, Include: Main ruler (1), the main ruler (1) is integrally provided as a cuboid structure, the main ruler (1) front side is provided with scale line, and the main ruler (1) left side segment bottom is fixed with left card tooth (101); Sub ruler (2), the sub ruler (2) is slidably installed in the slide groove (102) of the back of the main ruler (1), the left side segment bottom of the sub ruler (2) is fixed with right card tooth (201), and the right side segment of the main ruler (1) is limited by the limiting plate the sub ruler (2); Guide pin (3), installed on the front side of the sub ruler (2), for sliding in the guide slot (103) of the main ruler (1); Scale (4), installed on the front side of the sub ruler (2) by a plurality of screw rods, and the rear side of the scale (4) is attached to the front side of the main ruler (1), the front side of the scale (4) is provided with scale line, for measuring the axial dimension of the inner hole.

2. The measuring axial dimension of the inner hole gauge according to claim 1, wherein: The left card tooth (101) and the right card tooth (201) are the same shape, the left card tooth (101) and the right card tooth (201) are oppositely arranged, when the 0 scale line of the main ruler (1) corresponds to the 0 scale line of the scale (4), the right side of the left card tooth (101) and the left side of the right card tooth (201) are closely attached.

3. The measuring axial dimension of the inner hole gauge according to claim 2, wherein: The left card tooth (101) comprises a first clamping plate (5) and a second clamping plate (6); The first clamping plate (5) and the second clamping plate (6) are oppositely arranged, the inner side of the first clamping plate (5) and the second clamping plate (6) is provided with an inner frame (7), the inner frame (7) is provided with a sliding block (8) inside, and the bottom of the sliding block (8) is connected with a mark head (9) by a connecting rod, and the outer side end of the mark head (9) corresponds with the outer side of the left card tooth (101) in a flat manner.

4. The measuring axial dimension of the inner hole gauge according to claim 3, wherein: The outer side of the inner frame (7) is provided with an outer frame (10), the outer frame (10) is fixedly connected with the sliding block (8), the outer frame (10) is slidably sleeved on the outer side of the inner frame (7), the opposite two outer frames (10) are connected by a sleeve (11), a vertical rod (12) is vertically inserted into the sleeve (11), the top end of the vertical rod (12) inside the left card tooth (101) is connected with the bottom of the main ruler (1), and the top end of the vertical rod (12) inside the right card tooth (201) is connected with the bottom of the sub ruler (2).

5. The measuring axial dimension of the inner hole gauge according to claim 4, wherein: The inner side of the sliding block (8) is provided with a limiting component, the limiting component comprises: A sleeve (13) is installed on the inner side of the outer frame (10), and the outer frame (10) is connected with the sleeve (11) by the sleeve (13); A plug rod (14) is movably inserted into the sleeve (13), and a card tooth (141) is fixedly connected to the inner side end of the plug rod (14). A first elastic member (15) is arranged inside the sliding block (8) to drive the inner end of the insertion rod (14) to press the vertical rod (12).

6. The gauge for measuring the axial dimension of an inner hole according to claim 5, characterized in that: A baffle (16) is fixed on the top of the insertion rod (14), and a limiting groove (801) corresponding to the baffle (16) is formed on the top surface of the sliding block (8), and the elastic force of the first elastic member (15) enables the baffle (16) to slide inside the limiting groove (801).

7. The gauge for measuring the axial dimension of an inner hole according to claim 5, characterized in that: A plurality of clamping grooves (17) are arranged on the surface of the vertical rod (12), and the clamping tooth (141) on the inner end of the insertion rod (14) is correspondingly matched with the clamping grooves (17).

8. The gauge for measuring the axial dimension of an inner hole according to claim 4, characterized in that: A convex plate (18) is fixed on the side surface of the outer frame (10), and a side edge (19) is fixed on the inner side wall of the first clamping plate (5) and the second clamping plate (6), and a clamping component for limiting the convex plate (18) is arranged on the side edge (19), and the clamping component comprises: Two arc-shaped plates (20) are arranged, and the two arc-shaped plates (20) are oppositely arranged on the end of the convex plate (18); A sliding frame (21) is fixedly arranged on the top of the arc-shaped plate (20); A positioning rod (22) is fixedly arranged on the inner side wall of the side edge (19), and the sliding frame (21) is slidingly sleeved on the surface of the positioning rod (22); A second elastic member (23) is arranged inside the sliding frame (21) to drive the two arc-shaped plates (20) to move close to each other.

9. The gauge for measuring the axial dimension of an inner hole according to claim 8, characterized in that: A cross rod (24) penetrating through the sliding frame (21) is fixed on the surface of the positioning rod (22), and the sliding frame (21) moves on the surface of the cross rod (24).

10. The gauge for measuring the axial dimension of an inner hole according to claim 8, characterized in that: An arc-shaped piece (25) is arranged on the bottom of the arc-shaped plate (20), and the convex plate (18) moves up and slides between the two arc-shaped plates (20) by means of the arc-shaped piece (25).

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