CN213812006U - Measuring device for workpiece taper hole - Google Patents

Abstract

The utility model relates to a measure technical field, disclose a measuring device of work piece taper hole. The measuring device comprises a meter body and a telescopic rod, wherein the meter body is movably connected with the telescopic rod. The measuring device further comprises a measuring gauge, the measuring gauge is provided with a through hole, the telescopic rod penetrates through the through hole and can stretch out or retract relative to the measuring gauge, the meter body can measure and display the stretching amount of the telescopic rod, the part, far away from the meter body, of the measuring gauge is a first gauge section, the outer peripheral surface of the first gauge section is a conical surface, and the diameter of each position of the first gauge section in the axial direction is gradually reduced along the direction far away from the meter body. In this way, the utility model discloses can make things convenient for the instant, measurement on throne and the reduction measurement cost of work piece taper hole.

Description

Measuring device for workpiece taper hole

Technical Field

The utility model relates to a measure technical field, especially relate to a measuring device of work piece taper hole.

Background

At present, the taper hole of the workpiece is usually measured by disassembling the workpiece from a machine tool after the workpiece is machined, and measuring the workpiece by using a three-coordinate measuring instrument. That is to say, the in-place measurement of the workpiece cannot be realized at present, which causes that if the workpiece needs to be processed continuously, the processing precision cannot be ensured due to errors caused by secondary clamping of the workpiece. In addition, the three-coordinate measuring instrument is expensive, complex to operate, high in requirements on measuring personnel, extremely harsh in requirements on working environment, constant temperature and humidity, free of vibration and pollution and difficult to meet the requirement for immediate and in-place measurement in a workshop.

SUMMERY OF THE UTILITY MODEL

In view of this, the present invention provides a measuring device for workpiece taper hole, which can facilitate the instant and on-site measurement of workpiece taper hole and reduce the measurement cost.

In order to solve the technical problem, the utility model discloses a technical scheme be: a measuring device for workpiece taper holes is provided. The measuring device comprises a meter body and a telescopic rod, wherein the meter body is movably connected with the telescopic rod. The measuring device further comprises a measuring gauge, the measuring gauge is provided with a through hole, the telescopic rod penetrates through the through hole and can stretch out or retract relative to the measuring gauge, the meter body can measure and display the stretching amount of the telescopic rod, the part, far away from the meter body, of the measuring gauge is a first gauge section, the outer peripheral surface of the first gauge section is a conical surface, and the diameter of each position of the first gauge section in the axial direction is gradually reduced along the direction far away from the meter body.

In an embodiment of the present invention, the through hole includes a first hole section and a second hole section which are communicated with each other, an inner diameter of the first hole section is different from an inner diameter of the second hole section, the telescopic rod includes a first rod section and a second rod section which are connected with each other, a diameter of the first rod section is different from a diameter of the second rod section; the inner diameter of the first hole section is matched with the diameter of the first rod section, the first rod section is arranged in the first hole section in a penetrating mode, the inner diameter of the second hole section is matched with the diameter of the second rod section, and the second rod section is arranged in the second hole section in a penetrating mode.

In an embodiment of the invention, the inner diameter of the first bore section is equal to the diameter of the first rod section and the inner diameter of the second bore section is equal to the diameter of the second rod section.

In an embodiment of the present invention, the inner diameter of the first hole section is smaller than the inner diameter of the second hole section, the first hole section is far away from the watch body relative to the second hole section, the diameter of the first rod section is smaller than the diameter of the second rod section, and the first rod section is far away from the watch body relative to the second rod section.

In an embodiment of the present invention, the first rod section and the second rod section are relatively fixed, and the second rod section is movably connected to the watch body.

In an embodiment of the present invention, a portion of the measuring gauge near the gauge body is a second gauge section, and a diameter of each position of the second gauge section in the axial direction is equal.

In an embodiment of the present invention, the taper angle of the outer peripheral surface of the first gauge section is 5.767 ° ± 0.042 °.

In an embodiment of the present invention, the measuring gauge is fixed to the watch body.

In an embodiment of the present invention, when the end of the telescopic rod away from the watch body is flush with the end of the first gauge section away from the watch body, the reading of the watch body is zero.

The utility model discloses an in the embodiment, measuring device includes the amesdial, and the amesdial includes the table body and telescopic link.

The utility model has the advantages that: be different from prior art, the utility model provides a measuring device of work piece taper hole. The measuring device comprises a meter body and a telescopic rod, wherein the meter body is movably connected with the telescopic rod. The measuring device further comprises a measuring gauge, and the telescopic rod penetrates through the through hole of the measuring gauge and can extend out or retract relative to the measuring gauge. After the first gauge section of the measuring gauge is embedded into the taper hole of the workpiece, the meter body can measure and display the extension amount of the telescopic rod, and then whether the taper hole of the workpiece meets the requirements or not can be judged, and the processes can be carried out in the state that the workpiece is clamped on a machine tool, namely in-situ measurement. It can be seen that the utility model provides a measuring device can realize the instant, measurement on the throne of work piece taper hole to easy and simple to handle, measuring result is accurate, the structure is reliable, and the cost is lower simultaneously, can reduce measurement cost.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention. Moreover, the drawings and the description are not intended to limit the scope of the inventive concept in any way, but rather to illustrate it by those skilled in the art with reference to specific embodiments.

Fig. 1 is a schematic structural diagram of an embodiment of a measuring device for workpiece taper holes according to the present invention;

FIG. 2 is a schematic structural view of an embodiment of the artificial femoral head of the present invention;

fig. 3 is a schematic structural diagram of an embodiment of the measuring gauge of the present invention;

fig. 4 is a schematic structural diagram of an embodiment of a measuring state of the measuring device for workpiece taper holes according to the present invention;

fig. 5 is a schematic view illustrating an embodiment of a relationship between a radius variation and an axial dimension variation of a taper hole according to the present invention.

Detailed Description

To make the objects, technical solutions and advantages of the present invention clearer, embodiments of the present invention are combined to clearly and completely describe the technical solutions in the embodiments of the present invention, and obviously, the described embodiments are some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

The taper hole of inconvenient work piece is instant, the measurement and the higher technical problem of measurement cost on throne among the prior art for solving, an embodiment of the utility model provides a measuring device of work piece taper hole. The measuring device comprises a meter body and a telescopic rod, wherein the meter body is movably connected with the telescopic rod. The measuring device further comprises a measuring gauge, the measuring gauge is provided with a through hole, the telescopic rod penetrates through the through hole and can stretch out or retract relative to the measuring gauge, the meter body can measure and display the stretching amount of the telescopic rod, the part, far away from the meter body, of the measuring gauge is a first gauge section, the outer peripheral surface of the first gauge section is a conical surface, and the diameter of each position of the first gauge section in the axial direction is gradually reduced along the direction far away from the meter body. As described in detail below.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an embodiment of a measuring device for workpiece taper holes according to the present invention.

In an embodiment, the measurement device may be applied in the field of orthopedic implants, such as in-situ, on-site measurement of a tapered hole of an artificial femoral head, and the like.

Artificial hip replacement is one of the most successful operations in the history of surgical development, wherein the related orthopedic implants comprise an artificial femoral head, a femoral stem and the like, and the two need to realize firm fit locking between the two through specific and mutually meshed tapers so as to realize safe and effective implantation of the set of medical equipment in a human body.

The specific taper is a critical determining factor for the design and manufacture of artificial femoral heads and femoral stems, and if the specific taper cannot meet the set requirements, unequal leg lengths, postoperative pain, prosthesis loosening and abrasion increase can be caused, even infection of surrounding soft tissues is caused, the joint replacement operation fails, and a secondary revision operation is required.

Taking the artificial femoral head illustrated in fig. 2 as an example, the taper angle of the artificial femoral head is generally 5.767 degrees, the angular tolerance range is generally ± 0.042 degrees, and the tolerance range of the relevant diameter dimension of the artificial femoral head is generally ± 0.03 mm, the straightness is generally 0.003mm, and the roundness is generally 0.008 mm. In addition, the relative position precision of the conical surface of the artificial femoral head conical hole is higher, because the size is also a functional size, relates to the eccentricity of the artificial femoral head implant, and therefore needs to be less than or equal to 0.05 mm. In view of the above dimensional accuracy requirement, the processing and measurement of the artificial femoral head taper hole, especially the instant and in-situ measurement, to avoid unnecessary disassembly and assembly is a very delicate problem.

In view of this, the selection of the measuring tool capable of meeting the above accuracy requirement is very limited. High precision three-coordinate measuring machines are commonly used today. However, the machining of a workpiece such as the artificial femoral head cannot be completed at one time on a machine tool, and the workpiece needs to be detached from the machine tool and the taper hole of the workpiece is measured by using a three-coordinate measuring machine. That is to say, the in-place measurement of the workpiece cannot be realized at present, which causes that if the workpiece needs to be processed continuously, the processing precision cannot be ensured due to errors caused by secondary clamping of the workpiece. In addition, the three-coordinate measuring instrument is expensive, complex to operate, high in requirements on measuring personnel, extremely harsh in requirements on working environment, constant temperature and humidity, free of vibration and pollution and difficult to meet the requirement for immediate and in-place measurement in a workshop. The measuring device for the workpiece taper hole provided by the embodiment can well solve the technical problems in the prior art.

Specifically, the measuring device of the present embodiment includes a meter body 10 and an expansion link 20, and the meter body 10 is movably connected to the expansion link 20. The measuring device further comprises a measuring gauge 30, the measuring gauge 30 is provided with a through hole 31, and the telescopic rod 20 penetrates through the through hole 31 and can extend out or retract relative to the measuring gauge 30.

The portion of the measuring gauge 30 away from the watch body 10 is a first gauge section 32, the outer peripheral surface of the first gauge section 32 is a tapered surface, and the diameter of the first gauge section 32 at each position in the axial direction gradually decreases in the direction away from the watch body 10. The outer peripheral surface of the first gauge section 32 of the measuring gauge 30 corresponds to the inner conical surface of the workpiece taper hole, so that after the first gauge section 32 of the measuring gauge 30 is embedded into the taper hole of the workpiece, the first gauge section 32 of the measuring gauge 30 and the taper hole of the workpiece can be matched with each other, and whether the machining condition of the taper hole of the workpiece meets the requirement or not is detected.

The telescopic rod 20 extends or retracts relative to the measuring gauge 30, which means that the telescopic rod 20 also extends or retracts relative to the meter body 10, and the meter body 10 can measure and display the extension amount of the telescopic rod 20 so as to provide the reading of a measurer, and further detect whether the machining condition of the workpiece taper hole meets the requirement.

Referring to fig. 1 and 3, fig. 3 is a schematic structural diagram of an embodiment of the measuring gauge of the present invention.

In one embodiment, the through bore 31 of the gauge 30 includes a first bore section 311 and a second bore section 312 in communication, with the inner diameter of the first bore section 311 being different from the inner diameter of the second bore section 312. The telescopic rod 20 comprises a first rod segment 201 and a second rod segment 202 connected, the diameter of the first rod segment 201 being different from the diameter of the second rod segment 202.

Specifically, the inner diameter of the first bore section 311 matches the diameter of the first rod section 201, and the first rod section 201 is inserted into the first bore section 311 for guiding the first rod section 201 to move along the first bore section 311. The second bore section 312 has an inner diameter matching the diameter of the second rod section 202, and the second rod section 202 is inserted into the second bore section 312 for guiding the second rod section 202 to move along the second bore section 312. Therefore, the telescopic rod 20 can extend out or retract relative to the measuring gauge 30, and further, after the measuring gauge 30 extends into the taper hole of the workpiece, the telescopic rod 20 can extend out relative to the measuring gauge 30 to abut against the bottom of the blind hole of the workpiece, so as to perform corresponding measuring operation.

Further, the inner diameter of the first hole section 311 is equal to the diameter of the first rod section 201, which is beneficial to improve the guiding effect of the first hole section 311 for guiding the first rod section 201 to move along the first hole section 311 to the maximum extent, and to avoid the movement of the first rod section 201 deviating from the central axis of the measuring gauge 30. Similarly, the inner diameter of the second bore section 312 is equal to the diameter of the second rod section 202, which is beneficial to improve the guiding effect of the second bore section 312 for guiding the second rod section 202 to move along the second bore section 312 to the maximum extent, and to prevent the movement of the second rod section 202 from deviating from the central axis of the gauge 30.

Further, the inner diameter of the first hole section 311 is smaller than the inner diameter of the second hole section 312, the first hole section 311 is far away from the watch body 10 relative to the second hole section 312, the diameter of the first rod section 201 is smaller than the diameter of the second rod section 202, and the first rod section 201 is far away from the watch body 10 relative to the second rod section 202.

The first rod segment 201 and the second rod segment 202 are relatively fixed, and the second rod segment 202 is movably connected with the watch body 10. This means that the flexible connection between the telescopic rod 20 and the watch body 10 is, in particular, the flexible connection between the second rod section 202 and the watch body 10, so that the first rod section 201 and the second rod section 202 can extend or retract together relative to the watch body 10.

Please continue to refer to fig. 1. In one embodiment, the portion of the gauge 30 adjacent to the case body 10 is a second gauge section 33, and the second gauge section 33 has the same diameter at each position in the axial direction. That is, the gauge 30 includes a first gauge section 32 and a second gauge section 33 that are connected. The outer peripheral surface of the first gauge 32 is a tapered surface and the diameter of the first gauge 32 at each position in the axial direction is gradually reduced in a direction away from the watch body 10, while the diameter of the second gauge 33 at each position in the axial direction is equal. It will be appreciated that the first gauge section 32 of the gauge 30 has a sufficient axial dimension that is greater than the depth of the workpiece taper hole.

Of course, in other embodiments of the present invention, the gauge 30 may include only the first gauge section 32, and is not limited thereto.

Please continue to refer to fig. 1. In one embodiment, the gauge 30 is fixed to the watch body 10, that is, the gauge 30 and the watch body 10 are kept relatively fixed, so that the relative movement between the gauge 30 and the watch body 10 is prevented from affecting the accuracy of the measurement result.

Please continue to refer to fig. 1. In one embodiment, the measuring device comprises a dial indicator, which comprises a dial indicator body 10 and a telescopic rod 20. That is to say, the dial indicator 10 and the telescopic rod 20 of the present embodiment are in the form of a dial indicator, and the dial indicator has accurate reading, which is beneficial to improving the measurement accuracy of the processing condition of the workpiece taper hole. The principle that the gauge body 10 measures and displays the expansion amount of the telescopic rod 20 based on the form of the dial gauge belongs to the understanding scope of the technicians in the field, and is not described herein again.

The principle of the measuring device of the present embodiment for measuring the taper hole is described below, and the artificial femoral head is taken as an example, which is only needed for discussion and is not limited thereby:

referring to fig. 1 and 2, the artificial femoral head has a blind hole 40 for the artificial femoral stem to be inserted into, and the artificial femoral head and the artificial femoral stem are engaged with each other by a specific taper fit, so as to be locked firmly and reliably. The blind hole 40 of the artificial femoral head includes a straight hole 42 at the bottom of the hole in addition to a tapered hole 41, the tapered hole 41 is shown as being arranged with different diameters at different positions in the axial direction, the straight hole 42 is shown as being arranged with the same diameter at different positions in the axial direction, and the straight hole 42 is communicated with the tapered hole 41. Further, the cross-sections of the straight hole 42 and the tapered hole 41 are circular.

Figure 2 illustrates the theoretical dimensions of an exemplary embodiment of the artificial femoral head of the present invention. Of course, the sizes of different types of artificial femoral heads are different. In fig. 2, the theoretical depth of the blind hole 40 of the artificial femoral head is 15.20 ± 0.50mm, the theoretical depth of the taper hole 41 is 11.10 ± 0.50mm, the theoretical minimum diameter of the taper hole 41 is 12.579 ± 0.030mm, the theoretical taper angle of the taper hole 41 is 5.767 ° ± 0.042 °, i.e. 5 ° 46 '0 "± 0 ° 2' 30", and the theoretical straightness of the taper surface of the taper hole 41 is required to be 0.003 mm. As such, at the measurement point X where the depth of the blind hole 40 is 3.60mm, the diameter of the tapered hole 41 at the measurement point X should be 13.335 ± 0.030mm, while at the measurement point Y where the depth of the blind hole 40 is 9.60mm, the diameter of the tapered hole 41 at the measurement point Y should be 12.730 ± 0.030mm, and the taper angle of the portion of the tapered hole 41 between the measurement point X and the measurement point Y should be 5.767 ° ± 0.042 ° as described above.

However, in the actual machining process, due to the existence of errors caused by various factors, the actual machining condition of the blind hole 40 of the artificial femoral head needs to be further measured to detect whether the above theoretical dimensions are reached. It will be appreciated that the gauge 30 for measuring the tapered bore 41 of the femoral prosthesis is made strictly in accordance with the theoretical dimensions of the femoral prosthesis. For example, the first gauge section 32 of the measurement gauge 30 of the present embodiment is manufactured according to the theoretical size of the artificial femoral head, for example, the taper angle of the outer peripheral surface of the first gauge section 32 is 5.767 ° ± 0.042 ° as shown in fig. 3.

Referring to fig. 4, fig. 4 shows a state that the measuring gauge 30 of the measuring apparatus of the present embodiment is inserted into the blind hole 40 of the artificial femoral head until the measuring gauge cannot be inserted further. The measuring process specifically comprises the following steps: at least the peripheral surface of the first gauge section 32 of the measuring gauge 30 is coated with a plurality of pieces of display agent along the axial direction, then the measuring gauge 30 of the measuring device of the embodiment is inserted into the blind hole 40 of the artificial femoral head until the artificial femoral head cannot be inserted continuously, at this time, the measuring gauge 30 is matched with the tapered hole 41 of the artificial femoral head, the telescopic rod 20 extends to abut against the bottom of the blind hole 40, namely, the bottom of the straight hole 42 relative to the measuring gauge 30, and the meter body 10 displays the extension amount of the telescopic rod 20. The measuring device is then rotated through a certain angle and the reading displayed by the watch body 10 at that time is subsequently read.

After the measuring device is withdrawn from the blind hole 40 of the artificial femoral head, the distribution of the disclosing agent on the outer peripheral surface of the first gauge section 32 of the measuring gauge 30 is observed, and whether the taper angle of the taper hole 41 and the straightness of the taper surface meet the product requirements can be confirmed. The display agent is prepared by mixing red lead powder and engine oil according to a certain proportion, and 3 to 4 pieces of display agent can be smeared on the outer peripheral surface of the first section 32. The specific principle of confirming whether the taper angle of the tapered hole 41 and the straightness of the tapered surface satisfy the product requirements based on the distribution of the developer on the outer peripheral surface of the first gauge section 32 is based on a painting method commonly used for finished surface inspection, and will not be described herein again.

And, whether the relative position of the taper hole 41 in the blind hole 40 meets the requirement is judged by judging whether the current extension amount of the telescopic rod 20 meets the set value, and further whether the processing condition of the taper hole 41 meets the product requirement is judged. Specifically, when the machining condition of the taper hole 41 meets the product requirement, the distance between the measuring gauge 30 and the bottom of the blind hole 40 meets a set value, that is, the current extension amount (the reading displayed by the meter body 10) of the telescopic rod 20 meets the set value; when the taper hole 41 is too close to the bottom of the blind hole 40, the distance between the measuring gauge 30 and the bottom of the blind hole 40 is smaller than a set value when the measuring gauge 30 extends into the blind hole 40 of the artificial femoral head until the measuring gauge cannot extend into the blind hole 40 continuously, that is, the current extension amount (the reading displayed by the meter body 10) of the telescopic rod 20 is smaller than the set value, which means that the inner diameters of the measuring point X, the measuring point Y and other positions are too large; when the taper hole 41 is too far away from the bottom of the blind hole 40, the distance between the measuring gauge 30 and the bottom of the blind hole 40 is greater than a predetermined value when the measuring gauge 30 extends into the blind hole 40 of the artificial femoral head until the measuring gauge cannot extend further, that is, the current extension amount (the reading displayed by the meter body 10) of the telescopic rod 20 is greater than the predetermined value, which means that the inner diameters of the measuring points X and Y are too small.

Referring to fig. 5, the theoretical taper angle θ (θ may be 5.767 ° ± 0.042 ° or the like) of the tapered hole 41, the radius variation Δ r of the tapered hole 41, and the axial dimension variation Δ H of the tapered hole 41 have the following relationship: Δ r/Δ H is tan (θ/2). It can be seen that, because the theoretical taper angle θ of the tapered hole 41 is small, the ratio of the radial variation Δ r to the axial dimension variation Δ H of the tapered hole 41 is small, for example, when the theoretical taper angle θ of the tapered hole 41 is 5.767 ° ± 0.042 °, the ratio of the radial variation Δ r to the axial dimension variation Δ H of the tapered hole 41 is about 1: 20.

This means that there is a small variation in the radius of the tapered bore 41, which is enlarged by about 20 times and reflected in the axial dimension of the tapered bore 41, i.e. the difference between the radius of the measurement points X and Y and the theoretical dimension is enlarged by about 20 times and reflected in the distance between the gauge 30 and the bottom of the blind bore 40, i.e. in the reading of the watch body 10. Moreover, the dial indicator 10 and the telescopic rod 20 are in the form of dial indicators, and the dial indicators have accurate readings, so that the inside diameter conditions of the measuring points X and Y can be accurately reflected, and the measuring accuracy and reliability of the relative position of the taper hole 41 in the blind hole 40 can be ensured.

For example, as shown in fig. 4, when the end of the telescopic rod 20 away from the watch body 10 is flush with the end of the first gauge section 32 of the measuring gauge 30 away from the watch body 10, the reading of the watch body 10 is set to zero. And when the machining condition of the taper hole 41 meets the product requirement, the measuring gauge 30 extends into the blind hole 40 of the artificial femoral head until the measuring gauge cannot extend into the blind hole, at this time, the end part of the first gauge section 32 far away from the gauge body 10 is flush with the minimum diameter end of the taper hole 41 of the artificial femoral head, and at this time, the reading of the gauge body 10 is the distance between the minimum diameter end of the taper hole 41 of the artificial femoral head and the bottom of the blind hole 40 of the artificial femoral head, namely the difference between the theoretical depth of the blind hole 40 and the theoretical depth of the taper hole 41, specifically 4.1 mm.

Furthermore, the utility model discloses measuring device can be used for measuring the processing condition of different model artificial femoral head taper holes 41, wherein the utility model discloses the cone angle of its first rule section 32 outer peripheral face of measuring gauge 30 of measuring device equals with the cone angle of this different model artificial femoral head taper holes 41 to the external diameter that the tip of table body 10 was kept away from to first rule section 32 of measuring gauge 30 is less than or equal to in the minimum diameter of each artificial femoral head taper holes 41 in this different model artificial femoral head can.

To sum up, the utility model provides a measuring device of work piece taper hole, it includes the table body and telescopic link, table body and telescopic link swing joint. The measuring device further comprises a measuring gauge, and the telescopic rod penetrates through the through hole of the measuring gauge and can extend out or retract relative to the measuring gauge. After the first gauge section of the measuring gauge is embedded into the taper hole of the workpiece, the meter body can measure and display the extension amount of the telescopic rod, and then whether the taper hole of the workpiece meets the requirements or not can be judged, and the processes can be carried out in the state that the workpiece is clamped on a machine tool, namely in-situ measurement. It can be seen that the utility model provides a measuring device can realize the instant, measurement on the throne of work piece taper hole to easy and simple to handle, measuring result is accurate, the structure is reliable, and the cost is lower simultaneously, can reduce measurement cost.

Furthermore, in the present invention, unless otherwise expressly specified or limited, the terms "connected," "stacked," and the like are to be construed broadly, e.g., as meaning permanently connected, detachably connected, or integrally formed; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims (10)

1. A workpiece taper hole measuring apparatus, comprising:

the meter body is movably connected with the telescopic rod;

the meter comprises a meter body, a meter body and a telescopic rod, wherein the meter body is provided with a first gauge section, the telescopic rod penetrates through the through hole and can extend out or retract relative to the meter body, the meter body can measure and display the telescopic amount of the telescopic rod, the part of the meter body, which is far away from the meter body, of the meter body is the first gauge section, the outer peripheral surface of the first gauge section is a conical surface, and the diameter of the first gauge section at each position in the axial direction is gradually reduced along the direction of far away from the meter body.

2. The measuring device of claim 1,

the through hole comprises a first hole section and a second hole section which are communicated, the inner diameter of the first hole section is different from that of the second hole section, the telescopic rod comprises a first rod section and a second rod section which are connected, and the diameter of the first rod section is different from that of the second rod section;

wherein the inner diameter of the first bore section matches the diameter of the first rod section, the first rod section is disposed through the first bore section, the inner diameter of the second bore section matches the diameter of the second rod section, and the second rod section is disposed through the second bore section.

3. A measuring device according to claim 2, wherein the first bore section has an inner diameter equal to the diameter of the first rod section and the second bore section has an inner diameter equal to the diameter of the second rod section.

4. A measuring device according to claim 3, wherein the first bore section has an internal diameter smaller than the internal diameter of the second bore section, the first bore section being remote from the watch body relative to the second bore section, the first stem section having a diameter smaller than the diameter of the second stem section, the first stem section being remote from the watch body relative to the second stem section.

5. A measuring device as claimed in claim 4, wherein the first and second pole segments are relatively fixed and the second pole segment is movably connected to the watch body.

6. A measuring device as claimed in claim 1, wherein the portion of the gauge adjacent the case body is a second gauge section having an equal diameter at each location in the axial direction.

7. A measuring device according to claim 1, wherein the taper angle of the outer peripheral surface of the first gauge section is 5.767 ° ± 0.042 °.

8. A measuring device as claimed in any one of claims 1 to 7, characterized in that the gauge is fixed to the watch body.

9. A measuring device as claimed in any one of claims 1 to 7, wherein the meter body has a zero reading when the end of the telescopic rod remote from the meter body is level with the end of the first gauge section remote from the meter body.

10. The measuring device according to any one of claims 1 to 7, wherein the measuring device comprises a dial indicator, and the dial indicator comprises the indicator body and the telescopic rod.

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