CN220592845U

CN220592845U - Measuring clamp for motor end cover

Info

Publication number: CN220592845U
Application number: CN202321709379.4U
Authority: CN
Inventors: 王康康; 高力; 王健
Original assignee: Siemens Motor China Co ltd
Current assignee: Siemens Motor China Co ltd
Priority date: 2023-06-30
Filing date: 2023-06-30
Publication date: 2024-03-15
Anticipated expiration: 2033-06-30

Abstract

The application provides a measurement fixture of motor end cover, including bottom plate and N locating component, N is greater than or equal to 2, and every locating component includes: the second end of the positioning table is detachably arranged at a preset position of the bottom plate, the positioning table is provided with M pin holes extending from the first end face of the positioning table along the first direction, and M is more than or equal to 2; m floating positioning mechanisms, each floating positioning mechanism comprising: the floating positioning pin is arranged in the pin hole in a floating mode and can float between a first position and a second position along a first direction, the first position is that the first end of the floating positioning pin extends out of the first end of the positioning table by a preset distance D, and the second position is that the first end of the floating positioning pin is positioned in the positioning table; the locking mechanism is detachably connected with the floating locating pin and used for locking the floating locating pin at the second position; and by locking different floating locating pins at the second position, the measuring clamp of the motor end cover is applicable to motor end covers of different models.

Description

Measuring clamp for motor end cover

Technical Field

The embodiment of the application relates to the field of motor manufacturing, in particular to a measuring clamp for a motor end cover.

Background

The motor end cover is a core part of the motor, plays roles of supporting the transmission part, determining the relative position of the rotor and the stator and protecting internal devices of the motor, and has higher dimensional accuracy requirements. Once the dimensional accuracy deviates, the assembly performance of the end cover and the reliability of the motor are affected.

In the prior art, a manual mode is generally adopted to be matched with measuring tools such as a vernier caliper and a three-coordinate instrument to measure the key size of the motor end cover, and the manual measuring mode has the following problems:

(1) A large measurement error;

(2) More inspectors are required to be equipped, and the requirements of the inspectors on higher expertise are met, so that the labor cost is increased;

(3) The inspection time is long, the efficiency is low, and the hundred percent full inspection cannot be realized.

Disclosure of Invention

Based on the above-mentioned problems, the embodiments of the present application provide a measuring fixture of a motor end cover, which is matched with an automatic measuring device to measure the motor end cover, so as to at least partially solve the above-mentioned technical problems.

The application solves the technical problems through the following technical scheme:

the application provides a measurement clamp of motor end cover, a serial communication port, including bottom plate and N locating component, N is greater than or equal to 2, wherein, every locating component includes:

the second end of the positioning table is detachably arranged at a preset position of the bottom plate, M pin holes extending along the first direction from the first end face of the positioning table are formed in the positioning table, the first direction is perpendicular to the bottom plate, and M is more than or equal to 2;

m floating positioning mechanisms, wherein each of the floating positioning mechanisms comprises:

the floating locating pin is arranged in the pin hole in a floating mode and can float between a first position and a second position along a first direction, wherein the first position is that the first end of the floating locating pin extends out of a preset distance D relative to the first end of the locating table, the second position is that the first end of the floating locating pin is positioned in the locating table, and the floating locating pin at the first position is suitable for being inserted into a flange hole of a motor end cover along the reverse direction of the first direction and fixing the motor end cover along the circumferential direction;

the locking mechanism is detachably connected with the floating locating pin and used for locking the floating locating pin at the second position; and

by locking different floating locating pins at the second position, the measuring clamp of the motor end cover can be suitable for motor end covers of different types.

In one embodiment, the floating locator pin includes:

the guide sleeve is arranged in the pin hole;

the floating pin body penetrates through the guide sleeve and is in clearance fit with the guide sleeve;

the central shaft of the elastic piece is overlapped with the central shaft of the floating pin body, the first end of the elastic piece is connected with the second end of the floating pin body, and the second end of the elastic piece is connected with the positioning table;

when the floating locating pin is located at the first position, the elastic piece is in a free state.

In one embodiment, the side surface of the positioning table is provided with M L-shaped slideways, which comprise a first slideway and a second slideway, wherein the first slideway is parallel to the first direction, one end of the second slideway is communicated with the second end of the first slideway, and the length of the first slideway is longer than the preset distance D;

the locking mechanism is a handle, a first end of the handle is detachably connected with the floating pin body, a second end of the handle extends out of the positioning table through the L-shaped slide way, and the handle can move along the L-shaped slide way; the method comprises the steps of,

when the handle is positioned on the second slideway, the elastic piece is compressed, and the floating locating pin is locked at the second position.

In one embodiment, the first slide and the second slide are located on the same side of the positioning table, and the second slide is provided with a limit boss extending along the first direction; or alternatively, the first and second heat exchangers may be,

the second slide way comprises a first sub slide way and a second sub slide way which are respectively positioned on two adjacent side surfaces of the positioning table, wherein the first sub slide way and the first slide way are positioned on the same side surface of the positioning table, the first end of the first sub slide way is communicated with the second end of the first slide way, the second end of the first sub slide way is communicated with the second sub slide way, and the planes of the first sub slide way and the second sub slide way are parallel to the bottom plate.

In one embodiment, the floating pin body is a circular truncated cone-cylinder combination or a conical cone-cylinder combination, wherein the circular truncated cone or the conical cone is located at the first end of the floating pin body, the height H of the circular truncated cone or the conical cone is equal to the predetermined distance D, the diameter of the small end of the circular truncated cone or the conical cone is smaller than the diameter of the flange hole of the motor end cover matched with the small end of the circular truncated cone or the conical cone, and the diameter of the large end of the circular truncated cone or the conical cone is larger than the diameter of the flange hole matched with the small end of the circular truncated cone or the conical cone.

In one embodiment, the predetermined distance D is less than or equal to the depth of the flange aperture of the motor end cap with which the floating locator pin is engaged.

In one embodiment, the positioning table comprises a base and a top cover, wherein the top cover is detachably connected with the base, and the top cover is made of copper.

In one embodiment, n=2, the measuring fixture of the motor end cover further comprises P support tables having the same height as the positioning table (21), and the second end of each support table is detachably mounted on the bottom plate, wherein P is greater than or equal to 1.

In one embodiment, p=2, and the two support tables and the two positioning assemblies are arranged at intervals along the circumferential direction of the base plate.

In one embodiment, the supporting table is made of stainless steel, the surface roughness Ra of the first end surface of the supporting table is less than or equal to 6.3, and the edge of the first end surface of the supporting table is provided with a chamfer.

According to the measuring clamp of the motor end cover, according to the common characteristics of the motor end covers of various types, the installation position of the positioning table and the installation position of each floating positioning pin are planned, and the floating positioning pins are arranged to be capable of floating up and down along the first direction, so that at least two floating positioning pins are guaranteed to be matched with flange holes of the motor end cover to be measured, and other floating positioning pins float downwards and are hidden in the positioning table to avoid interference to the current motor end cover, so that the measuring clamp of the embodiment of the application can be applied to the motor end cover of various types, a special clamp is not required to be designed for each motor end cover, the motor end covers of similar outline dimensions share the same clamp, the number of the measuring clamp is greatly reduced, the design, manufacturing and storage cost of the clamp are further reduced, the clamp is avoided to be replaced manually frequently during measurement, and the working efficiency is greatly improved. According to the measuring clamp of the motor end cover, which is matched with the measuring equipment, automatic measurement of the motor end cover and automatic calibration of the measuring equipment are realized, the measuring accuracy is improved, and the measuring error and misjudgment of staff are avoided. Meanwhile, the measurement time is saved, the measurement efficiency is improved, and the hundred-percent full detection can be realized.

Drawings

The following drawings are only for purposes of illustration and explanation of the present application and are not intended to limit the scope of the present application. Wherein,

FIG. 1 shows an overall schematic of a measurement fixture of an embodiment of the present application;

FIG. 2 shows a schematic diagram of the assembly of a measuring clamp with a motor end cap;

FIG. 3 shows a schematic view of a positioning assembly of an embodiment of the present application;

fig. 4 shows an exploded view of a positioning assembly of an embodiment of the present application.

Reference numerals illustrate:

10: a bottom plate;

20: a positioning assembly;

21: a positioning table;

211: a base;

212: a top cover;

213: a pin hole;

214: a first slideway;

215 a second slide;

2151: a first sub-slideway;

2152: a second sub-slideway;

22, floating locating pins;

221: a guide sleeve;

222: a floating pin body;

223: an elastic member;

23: a handle;

30: a support table;

40: a motor end cover;

41: a flange hole;

s1, a first position;

s2, a second position;

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail below with reference to the accompanying drawings and examples. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application. All other technical solutions obtained by a person skilled in the art based on the examples in the present application fall within the scope of protection of the present application.

(1) A large measurement error;

(2) More pressure reducing personnel are required to be equipped, and the requirements of higher professional knowledge are met for the inspection personnel, so that the labor cost is increased;

A specific embodiment of the measuring jig of the present application will be described below with reference to fig. 1 to 4, in which an arrow 1B in the upper right corner represents a first direction, and an arrow 1A represents the opposite direction to the first direction. In a first direction, each component of the inspection jig has two ends, wherein a first end in the first direction may be denoted as 1A end and a second end in the second direction may be denoted as 1B end.

The embodiment of the application provides a measuring fixture of a motor end cover, which comprises a bottom plate 10 and at least two positioning assemblies 20. As shown in FIG. 1, each positioning assembly 20 comprises a positioning table 21 and M floating positioning mechanisms, wherein a second end (1B end) of the positioning table 21 is detachably mounted at a preset position of the bottom plate 10, a first end (1A end) surface of the positioning table 21 is provided with M pin holes 213 extending along a first direction from a first end (1A end) surface of the positioning table 21, and the first direction is perpendicular to the bottom plate 10, and M is greater than or equal to 2. Each floating positioning mechanism includes a floating positioning pin 22 and a locking mechanism. As shown in fig. 1 and 2, the floating alignment pins 22 are floatingly mounted in the corresponding pin holes 213, and the floating alignment pins 22 are floatable in a first direction (i.e., axial direction) between a first position S1, in which a first end (1A end) of the floating alignment pins 22 protrudes a predetermined distance D with respect to a first end (1A end) of the alignment stage 21, and a second position S2, in which the first end (1A end) of the floating alignment pins 22 is located in the alignment stage 21, as shown in fig. 3. The floating alignment pin 22 of the first position S1 is adapted to be inserted into the flange hole 41 of the motor end cap 40 in a direction opposite to the first direction and to circumferentially fix the motor end cap 40. The locking mechanism is detachably connected to the floating alignment pin 22, which locks the floating alignment pin 22 in the second position S2. By locking the different floating alignment pins 22 in the second position S2, the measuring fixture of the motor end cap is adapted to different types of motor end caps 40.

The specifications of the motor end cover are numerous, and even the motor end covers with the same or similar external dimensions, the hole sites and structures inside the motor end cover have differences. If a measuring clamp is only suitable for motor end covers of one specification, a plurality of clamps are required to be designed, the cost is high, and the storage management of the clamps is also a difficult problem. And the clamp is required to be frequently replaced during measurement, so that the time and the labor are consumed, the working efficiency is low, and the burden of workers is increased. According to the measuring clamp for the motor end cover, according to the common characteristics of the motor end covers of various types, the installation positions of the positioning table 21 and the installation positions of the floating positioning pins 22 are planned, the floating positioning pins 22 are arranged to be capable of floating up and down along the first direction, at least two floating positioning pins 22 are guaranteed to be matched with the flange holes 41 of the motor end cover 40 to be measured, other floating positioning pins 22 float downwards and are hidden in the positioning table 21 so as to avoid interference to the current motor end cover 40, so that the measuring clamp can be suitable for the motor end covers of various types, a special clamp is not required to be designed for each motor end cover, the motor end covers of similar outline dimensions share the same clamp, the number of measuring clamps is greatly reduced, the design, manufacturing and storage costs of the clamps are reduced, the clamps are avoided to be replaced manually frequently during measurement, and the working efficiency is greatly improved.

The measuring clamp of the motor end cover is suitable for motor end covers with various specifications, is matched with measuring equipment, achieves automatic measurement of the motor end cover and automatic calibration of the measuring equipment, improves measuring accuracy, and avoids measuring errors and misjudgment of staff. Meanwhile, the measurement time is saved, and the measurement efficiency is improved, so that the full detection of hundred percent can be realized.

In one embodiment, the floating alignment pin 22 includes a guide sleeve 221, a floating pin body 222, and an elastic member 223. As shown in fig. 4, a guide bush 221 is installed in the pin hole 213, and a floating pin body 222 is penetrated in the guide bush 221, which is clearance-fitted with the guide bush 221. The elastic member 223 is mounted at the lower end of the floating pin body 222, the first end (1A end) of the elastic member 223 is connected to the second end (1B end) of the floating pin body 222, the second end (1B end) of the elastic member 223 is connected to the positioning table 21, and the central axis of the elastic member 223 coincides with the central axis of the floating pin body 222. When the floating positioning pin 22 is located at the first position S1, the elastic member 223 is in a free state. When the floating pin body 222 is pressed downwards, the elastic member 223 is compressed to drive the floating pin body 222 to move downwards, and the guide sleeve 221 can enable the floating pin body 222 to move along the first direction.

In one embodiment, the elastic member 223 is a compression spring. The pressure spring has simple structure, lower manufacturing cost and good stability.

In one embodiment, the positioning table 21 is provided with M L-shaped slides on its sides. Each L-shaped slide includes a first slide 214 and a second slide 215 that are vertically disposed, as shown in fig. 3, the first slide 214 being parallel to the first direction, one end of the second slide 215 being in communication with the second end (1B end) of the first slide 214, the length of the first slide 214 being greater than the predetermined distance D. The locking mechanism is a handle 23, as shown in fig. 3 and 4, a first end (1A end) of the handle 23 is detachably connected to the floating pin body 222, a second end (1B end) of the handle 23 extends out of the positioning table 21 through a slideway, and the handle 23 can move along the L-shaped slideway; when the handle 23 slides downwards along the first slideway 214, the handle 23 applies downward pressure to the elastic piece 223 through the floating pin body 222, and the elastic piece 223 deforms under the action of external force so as to drive the floating pin body 222 to float upwards and downwards in the first direction; when the handle 23 is slid into the second slide 215, the floating alignment pin 22 is locked in the second position S2.

When it is desired to conceal a certain floating alignment pin 22, the operator can grasp the handle 23 to move it along the L-shaped slide. When the handle 23 moves downward along the first slideway 214, the handle 23 applies a downward pressure to the elastic member 223, the elastic member 223 is compressed to drive the floating pin body 222 to move downward, and the displacement Δl of the handle 23 along the first direction is equal to the deformation of the elastic member 223 and is equal to the displacement Δd of the floating pin body 222. When the handle 23 enters the second slide 215, the displacement of the handle 23 in the first direction is equal to the length L of the first slide 214, and thus the displacement of the floating pin 222 is also equal to the length L of the first slide 214, and since the length L of the first slide 214 is greater than the predetermined distance D, the floating pin 222 is fully entered into the floating platform when the handle 23 enters the second slide 215. The floating alignment pin 22 is locked in the second position S2 by a vertically disposed second slide 215.

In one embodiment, the first slide 214 and the second slide 215 are located on the same side of the positioning table 21, and a first end (1A end) surface or a second end (1B end) surface of the second slide 215 is provided with a limiting boss, where the limiting boss can fix the handle 23, so as to effectively prevent the handle from falling out of the second slide 215.

In another embodiment, the second slide 215 includes two sub-slides, namely a first sub-slide 2151 and a second sub-slide 2152, as shown in fig. 3 and 4, the first sub-slide 2151 and the second sub-slide 2152 are located on two adjacent sides of the positioning table 21, respectively, wherein the first sub-slide 2151 and the first slide 214 are located on the same side, a first end (1A end) of the first sub-slide 2151 communicates with a second end (1B end) of the first slide 214, a second end (1B end) of the first sub-slide 2151 communicates with the second sub-slide 2152, and a plane on which the first sub-slide 2151 and the second sub-slide 2152 are located is parallel to the bottom plate 10. The first sub-slide 2151 and the second sub-slide 2152 are respectively arranged on adjacent sides, on the one hand, the three-dimensional structure of the positioning table 21 is fully utilized, so that the total length of the second slide 215 is increased as much as possible in a limited space; on the other hand, when the handle 23 slides into the second sub-slideway 2152, the handle 23 rotates the floating pin body 222 by 90 °, further preventing the handle 23 from moving out of the second slideway 215.

In one embodiment, the floating pin body 222 is a circular truncated cone-cylinder combination or a conical-cylinder combination, as shown in fig. 1-4, the circular truncated cone or cone is located at a first end (1A end) of the floating pin body 222, the circular truncated cone or cone has a height H equal to a predetermined distance D, the diameter of the small end of the circular truncated cone or cone is smaller than the diameter of the flange hole 41 of the motor end cap 40 engaged therewith, and the diameter of the large end of the circular truncated cone or cone is larger than the diameter of the flange hole 41 engaged therewith. When the handle 23 is located on the first slideway 214, the elastic force of the elastic piece 223 enables the conical surface of the floating pin body 222 to be in close contact with the flange hole 41 all the time, so that the gap between the pin and the hole is eliminated, and the fixation of the motor end cover 40 in the circumferential direction is completed.

In one embodiment, the predetermined distance D is less than or equal to the depth of the flange aperture 41 of the motor end cap 40 that mates with the floating locator pin 22. That is, when the motor end cover 40 is placed on the measuring jig, the floating pin body 222 does not protrude out of the flange hole 41, thereby avoiding interference during automatic measurement and ensuring the accuracy of the test result.

In one embodiment, the positioning table 21 includes a base 211 and a top cover 212, the top cover 212 is detachably connected to the base 211, and the top cover 212 is made of copper. The material of the motor end cover 40 is usually an aluminum alloy with higher hardness, and in order to avoid the positioning table 21 from scratching the flange, a copper top cover 212 is used, and the hardness of copper is lower than that of the aluminum alloy, so that damage to the motor end cover 40 is avoided.

In one embodiment, two positioning assemblies 20 and P supporting tables 30 with the same height as the positioning tables 21 are installed on the bottom plate 10, and the second end (1B end) of each supporting table 30 is detachably installed on the bottom plate 10, wherein P is larger than or equal to 1. The positioning assembly 20 has both a supporting function and a positioning function, wherein the positioning function requires two positioning assemblies 20, and at least three positioning tables 21 are required to support the motor end cover 40 in order to ensure the flatness of the motor end cover 40 at the time of measurement. The positioning assembly 20 has a complex structure and high price. Thus, two positioning assemblies 20 and at least one support table 30 can be provided, while meeting the support and positioning requirements of the motor end cover 40, while reducing costs.

In one embodiment, two sets of positioning assemblies 20 and two support tables 30 are mounted on the base plate 10, and as shown in fig. 2, the two positioning assemblies 20 and the two support tables 30 are arranged at intervals along the circumferential direction of the base plate 10, so that the stress is more uniform.

In one embodiment, the support base 30 is made of stainless steel, and the surface roughness Ra of the first end surface (1A end surface) of the support base 30 is equal to or less than 6.3, and the edge of the first end surface (1A end surface) of the support base 30 has a chamfer.

The supporting table 30 is made of stainless steel, and the surface, which is in contact with the motor end cover 40, of the supporting table 30 is subjected to surface treatment, so that the roughness Ra of the surface is less than or equal to 6.3, and meanwhile, the edge of the first end face (1A end face) of the supporting table 30 is chamfered, so that the supporting table 30 is effectively prevented from scratching the motor end cover 40.

The foregoing is merely a preferred embodiment of the present application, and is not intended to limit the scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. The utility model provides a measurement fixture of motor end cover, its characterized in that includes bottom plate (10) and N locating component (20), and N is greater than or equal to 2, wherein, every locating component (20) include:

the second end of the positioning table (21) is detachably arranged at a preset position of the bottom plate (10), the positioning table (21) is provided with M pin holes (213) extending from the first end surface of the positioning table (21) along a first direction, and the first direction is perpendicular to the bottom plate (10), and M is more than or equal to 2;

a floating positioning pin (22) which is floatingly mounted in the pin hole (213), wherein the floating positioning pin (22) can float between a first position (S1) and a second position (S2) along a first direction, the first position (S1) is that a first end of the floating positioning pin (22) protrudes a predetermined distance D relative to a first end of the positioning table (21), the second position (S2) is that the first end of the floating positioning pin (22) is located in the positioning table (21), and the floating positioning pin (22) of the first position (S1) is suitable for being inserted into a flange hole (41) of a motor end cover (40) along a direction opposite to the first direction and fixing the motor end cover (40) along a circumferential direction;

a locking mechanism detachably connected to the floating positioning pin (22) for locking the floating positioning pin (22) at the second position (S2); and

by locking different floating locating pins (22) in the second position (S2), the measuring clamp of the motor end cover is applicable to motor end covers (40) of different types.

2. The measuring clamp of an end cover of an electric machine as claimed in claim 1, wherein the floating locating pin (22) comprises:

a guide sleeve (221) installed in the pin hole (213);

a floating pin body (222) penetrating the guide sleeve (221) and in clearance fit with the guide sleeve (221);

an elastic member (223) having a center axis coincident with the center axis of the floating pin body (222), a first end of the elastic member (223) being connected to a second end of the floating pin body (222), a second end of the elastic member (223) being connected to the positioning table (21);

wherein the elastic member (223) is in a free state when the floating positioning pin (22) is located at the first position (S1).

3. The measuring jig of motor end cover according to claim 2, wherein,

the side surface of the positioning table (21) is provided with M L-shaped slide ways which comprise a first slide way (214) and a second slide way (215), wherein the first slide way (214) is parallel to the first direction, one end of the second slide way (215) is communicated with the second end of the first slide way (214), and the length of the first slide way (214) is larger than the preset distance D;

the locking mechanism is a handle (23), a first end of the handle (23) is detachably connected with the floating pin body (222), a second end of the handle (23) extends out of the positioning table (21) through the L-shaped slideway, and the handle (23) can move along the L-shaped slideway; the method comprises the steps of,

when the handle (23) is located on the second slide (215), the elastic member (223) is compressed, and the floating positioning pin (22) is locked at the second position (S2).

4. A measuring clamp for motor end caps according to claim 3, characterized in that the first slide (214) and the second slide (215) are located on the same side of the positioning table (21), the second slide (215) being provided with a limit boss extending in the first direction; or alternatively, the first and second heat exchangers may be,

the second slide way (215) comprises a first sub slide way (2151) and a second sub slide way (2152) which are respectively positioned on two adjacent side surfaces of the positioning table (21), wherein the first sub slide way (2151) and the first slide way (214) are positioned on the same side surface of the positioning table (21), a first end of the first sub slide way (2151) is communicated with a second end of the first slide way (214), a second end of the first sub slide way (2151) is communicated with the second sub slide way (2152), and planes of the first sub slide way (2151) and the second sub slide way (2152) are parallel to the bottom plate (10).

5. The measuring jig of motor end caps according to claim 4, wherein the floating pin body (222) is a round table-cylinder combination or a cone-cylinder combination, wherein a round table or a cone is located at a first end of the floating pin body (222), a height H of the round table or the cone is equal to the predetermined distance D, a diameter of a small end of the round table or the cone is smaller than a diameter of a flange hole (41) of a motor end cap (40) to be fitted therewith, and a diameter of a large end of the round table or the cone is larger than a diameter of the flange hole (41) to be fitted therewith.

6. The measuring jig of motor end cover according to claim 5, wherein the predetermined distance D is less than or equal to a depth of a flange hole (41) of a motor end cover (40) to which the floating detent pin (22) is fitted.

7. The measuring fixture for motor end covers according to claim 6, wherein the positioning table (21) comprises a base (211) and a top cover (212), the top cover (212) is detachably connected with the base (211), and the top cover (212) is made of copper.

8. The measuring clamp of the motor end cover according to claim 7, wherein n=2, the measuring clamp of the motor end cover further comprises P supporting tables (30) with the same height as the positioning table (21), the second end of the supporting tables (30) is detachably mounted on the bottom plate (10), and P is larger than or equal to 1.

9. The measuring clamp of an end cover of an electric motor according to claim 8, characterized in that P = 2, two of said support tables (30) and two of said positioning assemblies (20) are arranged at intervals along the circumference of said base plate.

10. The measuring clamp of the motor end cover according to claim 9, wherein the supporting table (30) is made of stainless steel, the surface roughness Ra of the first end surface of the supporting table (30) is less than or equal to 6.3, and the edge of the first end surface of the supporting table (30) is provided with a chamfer.