Automatic grabbing mechanism for camshaft cover
Through the combination of the material box conveying raceway, 3D vision system and six-axis robot driving system, the efficient and accurate grasp of the camshaft cover is achieved, solving the problem of manual dependence in traditional camshaft cover grabbing operations, and improving production efficiency and equipment reliability.
Patent Information
- Application Number
- CN202422590959.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-25
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2034-10-25
AI Technical Summary
Traditional camshaft cover grabbing operations mainly rely on manual operations, which are labor-intensive, low-efficiency and prone to misoperation, which affects the production rhythm of the entire production line.
The material box conveying raceway, 3D vision system, six-axis robot driving system and cylinder head camshaft cover are automatically grasped by the robot. Through the six-axis robot driving system, the camshaft cover on the raceway is accurately grasped and placed in the position to be assembled.
It realizes efficient and accurate camshaft cover grabbing, reduces the intensity of human labor, avoids the phenomenon of missing camshaft cover, and improves the production rhythm and equipment reliability of the production line.
Smart Images

Figure CN223239107U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to an automatic grabbing mechanism for a camshaft cover, and relates to the technical field of automated production lines, in particular to an automatic grabbing mechanism for a camshaft cover of a logistics conveying cylinder head. Background Art
[0002] Traditional camshaft cover grasping operations rely primarily on manual labor, resulting in high labor intensity, low efficiency, and a high risk of operational errors. This represents a bottleneck in production efficiency, impacting the overall production line's tact time. With the advancement of industrial automation, the demand for efficient and precise grasping methods is becoming increasingly urgent.
[0003] In view of the problems existing in the above-mentioned prior art, it is very necessary to research and design a new type of camshaft cover automatic grasping mechanism to overcome the problems existing in the prior art. Summary of the Invention
[0004] According to the above-mentioned prior art, the traditional camshaft cover grabbing operation mainly relies on manual operation, which has technical problems such as high labor intensity, low efficiency, easy misoperation, and affecting the inspection rhythm of the entire production line. A camshaft cover automatic grabbing mechanism is provided. In order to realize the automatic grabbing of the camshaft cover by the manipulator, a material box conveying roller, a 3D vision system, a six-axis robot drive system, and a cylinder head camshaft cover automatic grabbing manipulator are used. The manipulator is driven by the six-axis robot drive system and guided by 3D vision to accurately grab the camshaft cover in the material box on the material box conveying roller. After grabbing, the robot places it in the position to be assembled. The grabbing content of this utility model is the cylinder head camshaft cover, the cylinder head camshaft positioning cover, the camshaft front bearing cover, the material box partition and the empty material box grabbing function.
[0005] The technical means adopted by this utility model are as follows:
[0006] A camshaft cover automatic grabbing mechanism includes: a mounting plate, a connecting flange, a camshaft cover grabbing module, a camshaft positioning cover grabbing module, a camshaft front bearing cover grabbing module, a material box grabbing module and a material box partition grabbing module;
[0007] Furthermore, the mounting plate is a cross-shaped plate structure having four support plates;
[0008] Furthermore, the four support plates of the mounting plate are sequentially equipped with a camshaft cover grabbing module, a camshaft positioning cover grabbing module, a camshaft front bearing cover grabbing module and a material box grabbing module;
[0009] Furthermore, a material box partition grabbing module is also assembled on the support plate assembled with the material box grabbing module;
[0010] Furthermore, a connecting flange is assembled on one side of the middle of the mounting plate, and the connecting flange is connected to the robot, and the robot drives the camshaft cover automatic grasping mechanism to complete the grasping work of various components.
[0011] Furthermore, the camshaft cover grabbing module, the camshaft positioning cover grabbing module and the camshaft front bearing cover grabbing module have the same structure, and all include: a cover grabbing mechanism and a material box partition pressing mechanism.
[0012] Furthermore, the cover grasping mechanism includes: a bracket, a guide shaft, a spring A, a linear bearing, a linear bearing connecting plate, an air gripper mounting plate, an air gripper A, a clamping block, a limit switch, a switch bracket A, a decree plate, a switch bracket B, and a proximity switch;
[0013] Furthermore, the rear end of the bracket is fixedly mounted on the lower portion of the support plate of the mounting plate;
[0014] Furthermore, two guide shafts are symmetrically mounted on the front end of the bracket;
[0015] Furthermore, the front end of each guide shaft is equipped with a linear bearing;
[0016] Furthermore, a spring A is mounted on the guide shaft, and both ends of the spring A are in contact with the bracket and the linear bearing respectively;
[0017] Furthermore, the linear bearing connecting plate is fixedly mounted on the upper portion of the two linear bearings;
[0018] Furthermore, the rear end of the air gripper mounting plate is fixedly mounted on the linear bearing connecting plate;
[0019] Furthermore, the air gripper A is fixedly mounted on the front end of the air gripper mounting plate;
[0020] Furthermore, two clamping blocks are symmetrically installed at both ends of the front of the air gripper A for grabbing the cover;
[0021] Furthermore, a switch bracket B is fixedly mounted on the top of the air gripper A;
[0022] Furthermore, the proximity switch is fixedly assembled with the front end of the switch bracket B;
[0023] Furthermore, the decree plate is fixedly mounted on the linear bearing connecting plate;
[0024] Furthermore, the limit switch is mounted on one side of the front end of the decree plate through a switch bracket A.
[0025] Furthermore, the material box partition pressing mechanism includes: a bracket, a cylinder connecting plate, a double-guide rod cylinder, a connecting plate, a pressing rod, a spring B, a limiting sleeve, and a self-lubricating sleeve;
[0026] Furthermore, the rear end of the bracket is fixedly mounted on the lower portion of the support plate of the mounting plate;
[0027] Furthermore, the double-guide-rod cylinder is fixedly mounted on the side of the bracket via a cylinder connecting plate;
[0028] Furthermore, one end of the connecting plate is fixedly mounted on the output end of the double-guide rod cylinder, and the other end is provided with a pressing rod; a self-lubricating sleeve is provided between the pressing rod and the connecting plate;
[0029] Furthermore, the limiting sleeve is mounted on the middle portion of the pressing rod, and a spring B is mounted on the pressing rod between the limiting sleeve and the connecting plate.
[0030] Furthermore, the specifications of the air gripper A vary according to the sizes of the camshaft cover, camshaft positioning cover and camshaft front bearing cover grasped by the camshaft cover grasping module, camshaft positioning cover grasping module and camshaft front bearing cover grasping module structure, so that the clamping block assembled thereon is suitable for grasping different cover bodies.
[0031] Furthermore, the length of the connecting plate varies according to the sizes of the camshaft cover, camshaft positioning cover and camshaft front bearing cover captured by the camshaft cover capture module, camshaft positioning cover capture module and camshaft front bearing cover capture module structure, so that the clamping rod assembled thereon can clamp different cover bodies.
[0032] Furthermore, the material box partition grasping module includes: a suction cup mounting plate, a suction cup and a diffuse reflection switch;
[0033] Furthermore, the suction cup mounting plate is fixedly mounted on the front end of the support plate of the mounting plate;
[0034] Furthermore, a suction cup is symmetrically mounted on each end of the suction cup mounting plate to hold the partition;
[0035] Furthermore, the diffuse reflection switch is fixedly mounted on the suction cup mounting plate.
[0036] Furthermore, the material box grabbing module includes: a left slide, a right slide, a left clamping block, a right clamping block, and an air gripper B;
[0037] Furthermore, the air gripper B is fixedly mounted on the upper front end of the support plate of the mounting plate on which the material box partition gripping module is mounted;
[0038] Furthermore, the air gripper B is equipped with a left slide plate and a right slide plate;
[0039] Furthermore, the left clamping block and the right clamping block are respectively mounted on the left slide plate and the right slide plate.
[0040] The working process of this utility model is:
[0041] The automatic grasping mechanism of the camshaft cover on the six-axis robot is guided by 3D vision to the top of the camshaft cover magazine (the air claw is in the closed state, and the magazine partition pressing mechanism is in the in-situ state). The clamp is inserted into the bottom hole of the camshaft cover bolt, and the air claw opens to clamp the camshaft cover. The double-guide rod cylinder extends to press the magazine partition (this design prevents the camshaft cover from driving the partition when grasping the camshaft cover). Repeat the above actions to grasp and position the bearing cover and the front bearing cover respectively. If the visual feedback signal indicates that there is no material in the magazine but there is a partition, the robot rotates the magazine partition grasping module downward to grasp the partition and place the partition in the designated position. If the visual feedback signal indicates that there is no material and no partition in the magazine. The robot rotates the magazine grasping module downward to grasp the magazine and place the magazine in the designated position.
[0042] Compared with the prior art, the utility model has the following advantages:
[0043] 1. The camshaft cover automatic grabbing mechanism provided by the utility model has a tight assembly and solves the problem of camshaft cover missing assembly;
[0044] 2. The camshaft cover automatic grabbing mechanism provided by the utility model reduces the labor intensity and solves the problems of increased labor costs.
[0045] 3. The camshaft cover automatic grabbing mechanism provided by the utility model has a proximity switch set at the clamping position to sense whether there is material on the camshaft cover at the grabbing position
[0046] 4. The camshaft cover automatic grabbing mechanism provided by the utility model has a material box partition pressing mechanism set at the clamping block position to prevent the camshaft cover from driving the partition
[0047] 5. The camshaft cover automatic grabbing mechanism provided by the utility model has the advantages of novel structure, simple processing, flexibility to adapt to different camshaft cover specifications, high reliability, and reduced labor costs.
[0048] In summary, the application of the technical solution of the utility model solves the problems in the traditional camshaft cover grasping operation in the existing technology, which mainly relies on manual operation, has high labor intensity, low efficiency, is prone to misoperation, and affects the inspection rhythm of the entire production line. BRIEF DESCRIPTION OF THE DRAWINGS
[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.
[0050] Figure 1 This is a schematic diagram of the structure of the utility model;
[0051] Figure 2 This is the P-direction view of the utility model;
[0052] Figure 3 This is the AA view of the present invention.
[0053] In the figure: 1, bracket 2, guide shaft 3, spring A 4, linear bearing 5, linear bearing connecting plate 6, air gripper mounting plate 7, air gripper A 8, clamping block 9, limit switch 10, switch bracket 1 11, decree plate 12, switch bracket 2 13, proximity switch 14, cylinder connecting plate 15, double guide rod cylinder 16, connecting plate 17, clamping rod 18, spring B 19, limit sleeve 20, self-lubricating sleeve 21, suction cup mounting plate 22, suction cup 23, diffuse reflection switch 24, left slide 25, right slide 26, left clamping block 27, right clamping block 28, air gripper B 29, mounting plate 30, connecting flange DETAILED DESCRIPTION
[0054] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.
[0055] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0056] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.
[0057] Unless otherwise specified, the relative arrangement of the parts and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technology, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.
[0058] In the description of the present invention, it needs to be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.
[0059] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.
[0060] In addition, it should be noted that the use of words such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of this utility model.
[0061] As shown in the figure, the utility model provides a camshaft cover automatic grasping mechanism including: a mounting plate 29, a connecting flange 30, a camshaft cover grasping module, a camshaft positioning cover grasping module, a camshaft front bearing cover grasping module, a material box grasping module and a material box partition grasping module; the mounting plate 29 is a cross-shaped plate structure with four support plates; the four support plates of the mounting plate 29 are sequentially equipped with the camshaft cover grasping module, the camshaft positioning cover grasping module, the camshaft front bearing cover grasping module and the material box grasping module; the support plate on which the material box grasping module is assembled is also equipped with a material box partition grasping module; a connecting flange 30 is equipped on one side of the middle part of the mounting plate 29, and the connecting flange 30 is connected to the robot, and the robot drives the camshaft cover automatic grasping mechanism to complete the grasping work of each component.
[0062] The camshaft cover grabbing module, the camshaft positioning cover grabbing module and the camshaft front bearing cover grabbing module have the same structure, and all include: a cover grabbing mechanism and a material box partition pressing mechanism.
[0063] The cover grabbing mechanism includes: a bracket 1, a guide shaft 2, a spring A3, a linear bearing 4, a linear bearing connecting plate 5, an air gripper mounting plate 6, an air gripper A7, a clamping block 8, a limit switch 9, a switch bracket A10, a decree plate 11, a switch bracket B12 and a proximity switch 13; the rear end of the bracket 1 is fixedly mounted on the lower part of the support plate of the mounting plate 29; two guide shafts 2 are symmetrically mounted on the front end of the bracket 1; a linear bearing 4 is mounted on the front end of each guide shaft 2; a spring A3 is mounted on the guide shaft 2, and the two ends of the spring A3 respectively conflict with the bracket 1 and the linear bearing 4 ; The linear bearing connecting plate 5 is fixedly mounted on the upper part of the two linear bearings 4; the rear end of the air gripper mounting plate 6 is fixedly mounted on the linear bearing connecting plate 5; the air gripper A7 is fixedly mounted on the front end of the air gripper mounting plate 6; two clamping blocks 8 are symmetrically mounted at both ends of the front of the air gripper A7 for grabbing the cover body; the top of the air gripper A7 is fixedly assembled with a switch bracket B12; the proximity switch 13 is fixedly assembled with the front end of the switch bracket B12; the decree plate 11 is fixedly mounted on the linear bearing connecting plate 5; the limit switch 9 is mounted on the front side of the decree plate 11 through the switch bracket A10.
[0064] The material box partition pressing mechanism includes: a bracket 1, a cylinder connecting plate 14, a double-guide rod cylinder 15, a connecting plate 16, a pressing rod 17, a spring B18, a limiting sleeve 19, and a self-lubricating sleeve 20; the rear end of the bracket 1 is fixedly mounted on the lower part of the support plate of the mounting plate 29; the double-guide rod cylinder 15 is fixedly mounted on the side of the bracket 1 through the cylinder connecting plate 14; one end of the connecting plate 16 is fixedly mounted on the output end of the double-guide rod cylinder 15, and the other end is equipped with a pressing rod 17; a self-lubricating sleeve 20 is installed between the pressing rod 17 and the connecting plate 16; the limiting sleeve 19 is installed in the middle of the pressing rod 17, and a spring B 18 is installed on the pressing rod 17 between the limiting sleeve 19 and the connecting plate 16.
[0065] The specifications of the air gripper A7 vary according to the sizes of the camshaft cover, camshaft positioning cover and camshaft front bearing cover grasped by the camshaft cover grasping module, camshaft positioning cover grasping module and camshaft front bearing cover grasping module structure, so that the clamping block 8 assembled thereon is suitable for grasping different cover bodies.
[0066] The length of the connecting plate 16 varies according to the sizes of the camshaft cover, camshaft positioning cover and camshaft front bearing cover captured by the camshaft cover capture module, camshaft positioning cover capture module and camshaft front bearing cover capture module structure, so that the clamping rod 17 assembled thereon can clamp different cover bodies.
[0067] The material box partition grabbing module includes: a suction cup mounting plate 21, a suction cup 22 and a diffuse reflection switch 23; the suction cup mounting plate 21 is fixedly mounted on the front end of the support plate of the mounting plate 29; a suction cup 22 is symmetrically installed at each end of the suction cup mounting plate 21 for sucking the partition; the diffuse reflection switch 23 is fixedly mounted on the suction cup mounting plate 21.
[0068] The material box grabbing module includes: a left slide 24, a right slide 25, a left clamping block 26, a right clamping block 27, and an air gripper B28; the air gripper B28 is fixedly mounted on the upper front end of the support plate of the mounting plate 29 on which the material box partition grabbing module is mounted; the air gripper B28 is equipped with the left slide 24 and the right slide 25; the left clamping block 26 and the right clamping block 27 are respectively mounted on the left slide 24 and the right slide 25.
[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A camshaft cover automatic grabbing mechanism, characterized by: The camshaft cover automatic grabbing mechanism comprises: a mounting plate (29), a connecting flange (30), a camshaft cover grabbing module, a camshaft positioning cover grabbing module, a camshaft front bearing cover grabbing module, a material box grabbing module and a material box partition grabbing module; The mounting plate (29) is a cross-shaped plate structure having four support plates; The four support plates of the mounting plate (29) are sequentially equipped with a camshaft cover grabbing module, a camshaft positioning cover grabbing module, a camshaft front bearing cover grabbing module and a material box grabbing module; The support plate on which the material box grabbing module is assembled is also equipped with a material box partition grabbing module; A connecting flange (30) is mounted on one side of the middle portion of the mounting plate (29), and the connecting flange (30) is connected to a robot, which drives an automatic grasping mechanism of the camshaft cover to complete grasping work of various components.
2. The camshaft cover automatic gripping mechanism according to claim 1, characterized in that: The camshaft cover grabbing module, the camshaft positioning cover grabbing module and the camshaft front bearing cover grabbing module have the same structure, and all include: a cover grabbing mechanism and a material box partition pressing mechanism.
3. The camshaft cover automatic grabbing mechanism according to claim 2, characterized in that: The cover grabbing mechanism comprises: a bracket (1), a guide shaft (2), a spring A (3), a linear bearing (4), a linear bearing connecting plate (5), an air gripper mounting plate (6), an air gripper A (7), a clamping block (8), a limit switch (9), a switch bracket A (10), a decree plate (11), a switch bracket B (12) and a proximity switch (13); The rear end of the bracket (1) is fixedly mounted on the lower portion of the support plate of the mounting plate (29); The front end of the bracket (1) is symmetrically provided with two guide shafts (2); The front end of each guide shaft (2) is equipped with a linear bearing (4); The guide shaft (2) is equipped with a spring A (3), and the two ends of the spring A (3) are respectively in conflict with the bracket (1) and the linear bearing (4); The linear bearing connecting plate (5) is fixedly mounted on the upper parts of the two linear bearings (4); The rear end of the air claw mounting plate (6) is fixedly mounted on the linear bearing connecting plate (5); The air gripper A (7) is fixedly mounted on the front end of the air gripper mounting plate (6); Two clamping blocks (8) are symmetrically installed at both ends of the front of the air gripper A (7) for grasping the cover; The top end of the air gripper A (7) is fixedly mounted with a switch bracket B (12); The proximity switch (13) is fixedly assembled with the front end of the switch bracket B (12); The decree plate (11) is fixedly mounted on the linear bearing connecting plate (5); The limit switch (9) is mounted on one side of the front end of the decree plate (11) through a switch bracket A (10).
4. The camshaft cover automatic grabbing mechanism according to claim 2, characterized in that: The material box partition pressing mechanism comprises: a bracket (1), a cylinder connecting plate (14), a double-guide rod cylinder (15), a connecting plate (16), a pressing rod (17), a spring B (18), a limiting sleeve (19), and a self-lubricating sleeve (20); The rear end of the bracket (1) is fixedly mounted on the lower portion of the support plate of the mounting plate (29); The double-guide-rod cylinder (15) is fixedly mounted on the side of the bracket (1) via a cylinder connecting plate (14); One end of the connecting plate (16) is fixedly mounted on the output end of the double-guide rod cylinder (15), and the other end is provided with a pressing rod (17); a self-lubricating sleeve (20) is provided between the pressing rod (17) and the connecting plate (16); The limiting sleeve (19) is installed on the middle part of the pressing rod (17), and a spring B (18) is installed on the pressing rod (17) between the limiting sleeve (19) and the connecting plate (16).
5. The camshaft cover automatic grabbing mechanism according to claim 3, characterized in that: The specifications of the air gripper A (7) are different according to the sizes of the camshaft cover, camshaft positioning cover and camshaft front bearing cover grasped by the camshaft cover grasping module, camshaft positioning cover grasping module and camshaft front bearing cover grasping module structures, so that the clamping block (8) assembled thereon is suitable for grasping different cover bodies.
6. The camshaft cover automatic gripping mechanism according to claim 4, characterized in that: The length of the connecting plate (16) varies according to the sizes of the camshaft cover, camshaft positioning cover and camshaft front bearing cover captured by the camshaft cover capturing module, camshaft positioning cover capturing module and camshaft front bearing cover capturing module structures, so that the pressing rod (17) assembled thereon can press different cover bodies.
7. The camshaft cover automatic gripping mechanism according to claim 1, characterized in that: The material box partition grabbing module comprises: a suction cup mounting plate (21), a suction cup (22) and a diffuse reflection switch (23); The suction cup mounting plate (21) is fixedly mounted on the front end of the support plate of the mounting plate (29); The two ends of the suction cup mounting plate (21) are symmetrically equipped with a suction cup (22) for sucking the partition; The diffuse reflection switch (23) is fixedly mounted on the suction cup mounting plate (21).
8. The camshaft cover automatic gripping mechanism according to claim 1, characterized in that: The material box grabbing module comprises: a left slide plate (24), a right slide plate (25), a left clamping block (26), a right clamping block (27), and an air gripper B (28); The air claw B (28) is fixedly mounted on the upper front end of the support plate of the mounting plate (29) on which the material box partition grabbing module is mounted; The air gripper B (28) is equipped with a left slide plate (24) and a right slide plate (25); The left clamping block (26) and the right clamping block (27) are respectively mounted on the left slide plate (24) and the right slide plate (25).