CN212917935U

CN212917935U - Reaming tapping machine

Info

Publication number: CN212917935U
Application number: CN202021291214.6U
Authority: CN
Inventors: 丁覃
Original assignee: Beijing Dongnan Automobile Parts Co ltd
Current assignee: Beijing Dongnan Automobile Parts Co ltd
Priority date: 2020-07-03
Filing date: 2020-07-03
Publication date: 2021-04-09
Anticipated expiration: 2030-07-03

Abstract

The application relates to a reaming tapping machine, which solves the problem of inconvenient reaming and tapping of parts in the prior art; the device comprises a workbench, a hole expanding machine and a thread tapping machine which are arranged on two sides of the workbench, a lifting assembly which is arranged on the workbench and respectively corresponds to the hole expanding machine and the thread tapping machine and is used for driving the hole expanding machine and the thread tapping machine to lift up and down, a clamping assembly which is arranged on the workbench and a first positioning assembly which is arranged on the workbench and is used for driving the clamping assembly to linearly slide along the arrangement direction of the hole expanding machine and the thread tapping machine; a reaming shaft lever is vertically arranged at one end of the reaming machine facing the workbench; a hole expanding drill bit is arranged at one end of the hole expanding shaft lever facing the workbench; a tapping shaft lever is vertically arranged at one end of the thread tapping machine facing the workbench; and a tapping drill bit is arranged at one end of the tapping shaft rod facing the workbench. The utility model has the advantage of more convenient operation.

Description

Reaming tapping machine

Technical Field

The application relates to the technical field of machining equipment, in particular to a reaming tapping machine.

Background

At present, threaded connection is one of the most important and common connection modes between parts, and in order to realize the threaded connection between the parts, threaded holes need to be processed on the parts; the method for processing the threaded holes on the parts is also called tapping or tapping, and various tapping modes are adopted, such as reaming tapping and reaming tapping; in the reaming and tapping, a drill bit is directly used for drilling threaded holes in parts, and the tapping method needs to accurately position the tapping part before tapping; in the reaming and tapping process, a positioning hole is formed in a part to be tapped in advance, then a reaming machine is used for processing and expanding the positioning hole, and then a tapping machine is used for processing threads; for example, when an automobile part is produced, a direct pouring mode is adopted to improve the strength of the part, when the part is poured, a positioning hole is poured at a position needing tapping, and because the inner side wall of the poured positioning hole is rough and has a small aperture, a hole expanding machine is needed to process the inside of the positioning hole and expand the aperture of the positioning hole, and then an internal thread is formed in the hole by the tapping machine.

In the existing reaming and tapping method, two workers respectively operate two devices, namely a reaming machine and a tapping machine, a cast part firstly processes and expands a positioning hole through the reaming machine and then processes a thread in the hole through the tapping machine.

With respect to the related art among the above, the inventors consider that the following drawbacks exist: when the parts are reamed and tapped, the parts are subjected to a large acting force from a reaming machine or a tapping machine, positioning holes are required to be kept in a vertical state all the time during reaming and tapping, and the parts cannot be skewed during reaming or tapping, so that the parts are required to be clamped and positioned; by using the technical scheme, the reaming and tapping of the parts are separately operated, the parts need to be respectively clamped on the reaming machine and the tapping machine, and the operation is inconvenient.

SUMMERY OF THE UTILITY MODEL

In order to improve the convenience of spare part reaming and tapping operation, this application provides a reaming tapping machine.

The application provides a pair of reaming tapping machine adopts following technical scheme:

a hole-drawing tapping machine comprises a workbench, a hole-expanding machine and a thread tapping machine which are arranged on two sides of the workbench, a lifting assembly which is arranged on the workbench and respectively corresponds to the hole-expanding machine and the thread tapping machine and is used for driving the hole-expanding machine and the thread tapping machine to lift up and down, a clamping assembly which is arranged on the workbench and is used for clamping and fixing parts, and a first positioning assembly which is arranged on the workbench and is used for driving the clamping assembly to linearly slide along the arrangement direction of the hole-expanding machine and the thread tapping machine; a driving module and a control module are arranged inside the hole expanding machine and the thread tapping machine; a reaming shaft lever is vertically arranged at one end of the reaming machine facing the workbench; a hole expanding drill bit is arranged at one end of the hole expanding shaft lever facing the workbench; a tapping shaft lever is vertically arranged at one end of the thread tapping machine facing the workbench; and a tapping drill bit is arranged at one end of the tapping shaft rod facing the workbench.

By adopting the technical scheme, when the component is subjected to reaming and tapping, the component is firstly placed on the clamping assembly to be clamped and fixed, then the first positioning assembly is started, and the clamping assembly slides between the reaming machine and the thread tapping machine under the driving of the first adjusting assembly; the clamping assembly firstly slides to a position below a hole expanding drill bit of the hole expanding machine, then the hole expanding machine is started, the hole expanding drill bit rotates on a hole expanding shaft lever, the hole expanding machine moves downwards under the driving of the lifting assembly, and the hole expanding drill bit drills into a positioning hole to process and expand the positioning hole; after reaming, the reaming bit moves upwards under the driving of the lifting assembly; then starting the first positioning assembly, driving the clamping assembly to move towards the direction of the thread tapping machine by the first positioning assembly, starting the thread tapping machine when the clamping assembly moves below the thread tapping machine, driving the thread tapping machine to move downwards by the lifting assembly, and forming internal threads on the inner wall of the hole in the tapping drill bit insertion hole; through adopting above-mentioned scheme, when carrying out the reaming tapping to spare part, only need start the adjustment that the position subassembly can accomplish spare part position between reamer and tapping machine, therefore only need carry out a clamping to spare part, improved the convenience of spare part reaming tapping operation.

Preferably, the lifting assembly comprises a vertical seat, a cylinder, a guide block and a mounting frame; the vertical seat is arranged on the workbench and internally provided with an installation groove extending along the length direction of the vertical seat; the cylinder is arranged in the mounting groove, and the axis of the output end is parallel to the extending direction of the mounting groove; the guide block is arranged in the mounting groove and is in sliding fit with the mounting groove; the guide block is fixedly connected with the output end of the air cylinder; a guide groove which has an extension direction parallel to the extension direction of the mounting groove and is communicated with the inside of the mounting groove is arranged at a position on the vertical seat corresponding to the guide block; the guide block which is provided with a convex guide groove and is matched with the guide groove in a sliding way is fixedly connected with the position of the guide block corresponding to the guide groove; the mounting frame is fixedly connected with the guide block; the hole expanding machine and the thread tapping machine are fixedly connected with the mounting frame.

Through adopting above-mentioned technical scheme, start the cylinder, drive the guide block and slide from top to bottom under the drive of cylinder, the guide block drives the connecting block and slides from top to bottom to drive reamer or the screw hole tapping machine on the mounting bracket and reciprocate, conveniently carry out reaming or tapping to spare part.

Preferably, a first positioning chute extending along the arrangement direction of the hole expanding machine and the thread tapping machine is formed in the workbench; the first positioning component comprises a positioning screw rod which is rotatably supported in the first positioning chute and a positioning slide block which is screwed on the positioning screw rod and is in sliding fit with the first positioning chute; the clamping assembly is arranged on the position adjusting sliding block.

Through adopting above-mentioned technical scheme, through the rotation of positioning lead screw, the positioning slider slides in first positioning spout to adjust the position of clamping component between reamer and screw tapping machine, conveniently carry out reaming and tapping to spare part.

Preferably, the first positioning component further comprises a servo motor with an output end coaxially and fixedly connected to one end of the positioning screw rod.

Through adopting above-mentioned technical scheme, compare in artificial drive, servo motor's precision is higher, and is comparatively laborsaving moreover, makes the regulation of first adjusting part to holding the subassembly position more laborsaving convenience.

Preferably, the clamping assembly comprises a bottom plate, a side clamping plate, a clamping screw rod, a side clamping plate and an adjusting block; the bottom plate is arranged on the first adjusting assembly; the side clamping plate is arranged on one surface of the bottom plate, which is far away from the first adjusting component; a movable clamping plate with a plate surface opposite to the side clamping plate is arranged on one side of the bottom plate opposite to the side clamping plate; a clamping chute with the extending direction parallel to the arrangement direction of the side clamping plate and the movable clamping plate is arranged between the side clamping plate and the movable clamping plate on the bottom plate; the clamping screw rod is rotatably supported in the clamping chute; the adjusting block is screwed on the clamping screw rod and is in sliding fit with the clamping sliding groove.

Through adopting above-mentioned technical scheme, through rotating the centre gripping lead screw, moving clamp moves towards or deviates from the side splint to press from both sides tight or locking to spare part, make the tight fixed more convenient of clamp of spare part.

Preferably, a second positioning component is arranged between the first positioning component and the clamping component; the second positioning component comprises a mounting seat, a positioning screw rod and a positioning sliding block; the mounting seat is arranged on the first positioning component; a second positioning chute with the extending direction perpendicular to the arrangement direction of the hole expanding machine and the thread tapping machine is formed in the mounting seat; the positioning screw rod is rotatably supported in the second positioning chute; the positioning slide block is in threaded connection with the positioning screw rod and is in sliding fit with the second positioning sliding groove.

By adopting the technical scheme, the positioning screw rod is rotated, the positioning screw rod rotates in the second positioning sliding groove, so that the positioning sliding block is driven to slide in the second clamping sliding groove, and the positioning groove drives the clamping assembly to slide on the mounting seat; through first positioning subassembly and second positioning subassembly, can make spare part adjust in X axle and Y axle direction, every locating hole on the spare part in certain scope all is in reaming tapping process range, has further reduced the clamping number of times of spare part to the convenience of spare part reaming tapping operation has further been improved.

Preferably, the guide grooves are two and symmetrically arranged on two sides of the vertical seat.

Through adopting above-mentioned technical scheme, improve reamer and screw tapping machine in the stability and the smoothness degree of lift subassembly upper and lower displacement.

Preferably, the bottom plate is symmetrically provided with limiting grooves with extending directions parallel to the extending direction of the clamping sliding groove on two sides of the clamping sliding groove; a limiting block is arranged on the movable clamping plate corresponding to the limiting groove; the limiting block is embedded in the limiting groove and is in sliding fit with the limiting groove.

Through adopting above-mentioned technical scheme, improve the stability and the smoothness degree that movable clamp plate slided on the bottom plate to improve the stability of side splint and movable clamp plate to the spare part centre gripping.

In summary, the present application includes at least one of the following beneficial technical effects:

1. compared with the prior art, the utility model improves the convenience of reaming and tapping operation of parts by arranging the first positioning component;

2. through setting up second adjusting part, the convenience of spare part reaming tapping operation has further been improved.

Drawings

FIG. 1 is a schematic diagram of a reaming tapping machine;

FIG. 2 is a cross-sectional view of the first positioning assembly and the second positioning assembly;

fig. 3 is a cross-sectional view showing the structure of the clamping assembly.

Description of reference numerals: 1. A work table; 10. a first positioning chute; 2. a lifting assembly; 20. a vertical seat; 200. mounting grooves; 201. a guide groove; 21. a cylinder; 22. a guide block; 220. connecting blocks; 23. a mounting frame; 3. a hole expanding machine; 30. reaming the shaft lever; 300. a hole expanding drill bit; 4. a thread tapping machine; 40. tapping the shaft rod; 400. tapping drill bits; 5. a first positioning component; 50. adjusting a lead screw; 51. a position adjusting slide block; 52. a servo motor; 6. a clamping assembly; 60. a base plate; 600. clamping the chute; 601. a limiting groove; 61. a side clamping plate; 62. clamping the screw rod; 620. a hand wheel; 63. an adjusting block; 64. moving the clamping plate; 640. a limiting block; 7. a second positioning component; 70. a mounting seat; 700. a second positioning chute; 71. positioning a lead screw; 710. a handle; 72. and positioning the slide block.

Detailed Description

The present application is described in further detail below with reference to figures 1-3.

The embodiment of the application discloses drilling and tapping machine. Referring to fig. 1, the reaming tapping machine includes a workbench 1 with a horizontal upper surface, two lifting assemblies 2 arranged on one side of the workbench 1 and along the length direction of the workbench 1, a reaming machine 3 and a thread tapping machine 4 respectively arranged on the two lifting assemblies 2, a first positioning assembly 5 arranged on the workbench 1 and located between the two lifting assemblies 2, and a clamping assembly 6 arranged on the first positioning assembly 5 and driven by the first positioning assembly 5 to linearly move between the two lifting assemblies 2.

Referring to fig. 1 and 2, the reamer 3 and the thread tapping machine 4 are internally provided with circuit modules such as a driving module, a control module and the like; a hole expanding shaft rod 30 is vertically arranged at one end of the hole expanding machine 3 facing the workbench 1; a hole expanding drill bit 300 is arranged at one end of the hole expanding shaft rod 30 facing the workbench 1; a tapping shaft lever 40 is vertically arranged at one end of the thread tapping machine 4 facing the workbench 1; a tapping drill 400 is arranged at one end of the tapping shaft rod 40 facing the workbench 1; the lifting assembly 2 comprises a vertical base 20, a cylinder 21, a guide block 22 and a mounting frame 23; the vertical seat 20 is arranged on the workbench 1 and is internally provided with a mounting groove 200; the cylinder 21 is arranged in the mounting groove 200 of the vertical seat 20, and the output end of the cylinder is vertically upward; the guide block 22 is fixedly connected with the output end of the cylinder 21 and is in sliding fit with the mounting groove 200; two guide grooves 201 are symmetrically arranged on two opposite sides of the vertical seat 20 along the vertical direction; a connecting block 220 is convexly arranged on the guide block 22 at a position corresponding to the guide groove 201; one end of the connecting block 220, which is far away from the guide block 22, protrudes out of the guide groove 201 and is in sliding fit with the guide groove 201; the mounting frame 23 is fixedly connected with the connecting blocks 220 on the two sides of the vertical seat 20; the reamer 3 and the thread tapping machine 4 are fixedly connected with the mounting frames 23 on the two lifting assemblies 2 respectively.

Referring to fig. 3, the clamp assembly 6 includes a base plate 60, a side clamp plate 61, a clamp screw 62, an adjusting block 63, and a moving clamp plate 64; the bottom plate 60 is horizontally arranged; a side clamping plate 61 with a plate surface vertical to the plate surface of the bottom plate 60 is fixedly connected to one side of the bottom plate 60; a clamping chute 600 with the extending direction vertical to the surface of the side plate is arranged on the bottom plate 60; the clamping screw 62 is rotatably supported in the clamping chute 600 and the length direction is parallel to the extending direction of the clamping chute 600; one end of the clamping screw rod 62 departing from the side clamping plate 61 penetrates through the clamping sliding groove 600; an annular hand wheel 620 is arranged at one end of the clamping screw rod 62 penetrating out of the clamping chute 600; the adjusting block 63 is arranged in the clamping chute 600 and is in threaded connection with the clamping screw rod; the plate surface of the movable clamping plate 64 is arranged opposite to the plate surface of the side clamping plate 61; the bottom side of the movable clamping plate 64 is fixedly connected with the adjusting block 63; when the screw is rotated, the movable clamp plate 64 moves toward or away from the side clamp plate 61.

In order to further improve the stability of the movable clamp plate 64 sliding on the bottom plate 60, referring to fig. 3, a plurality of limiting grooves 601 are formed on one surface of the bottom plate 60, which is provided with the clamping sliding groove 600, and the extending direction of the limiting grooves is parallel to the extending direction of the clamping sliding groove 600; a position of the bottom of the movable clamp plate 64 corresponding to the position of the limiting groove 601 is provided with a limiting block 640, and the limiting block 640 is embedded in the limiting groove 601 and is matched with the limiting groove 601 in a sliding manner.

Referring to fig. 2, a first positioning chute 10 extending along the arrangement direction of the two lifting assemblies 2 is arranged below the two lifting assemblies 2 on the worktable 1; the first positioning component 5 comprises a positioning screw 50 which is rotatably supported in the first positioning chute 10 and one end of which penetrates out of the first positioning chute 10, a positioning slider 51 which is screwed on the positioning screw 50 and is in sliding fit with the first positioning chute 10, and a servo motor 52 which is coaxially and fixedly connected with one end of the positioning screw 50, which penetrates out of the first positioning chute 10; the clamping assembly 6 is arranged on the positioning slide block 51.

The implementation principle of the embodiment is as follows: when reaming and tapping are performed on parts, the parts are firstly placed on the bottom plate 60 of the clamping assembly 6, then the hand wheel 620 of the clamping assembly 6 is rotated, the lead screw rotates to drive the adjusting block 63 to slide in the clamping chute 600, the movable clamping plate 64 moves towards the side clamping plate 61, and the parts are clamped and positioned by the side clamping plate 61 and the movable clamping plate 64; then, a servo motor 52 on the first positioning component 5 is started, the servo motor 52 drives a positioning screw rod 50 to rotate, a positioning sliding block 51 slides in the first positioning sliding groove 10, and the positioning sliding block 51 drives the clamping component to slide between the hole expanding machine 3 and the thread tapping machine 4; the clamping assembly firstly slides to a position below a hole expanding drill bit 300 of the hole expanding machine 3, then the hole expanding machine 3 is started, the hole expanding drill bit 300 rotates on a hole expanding shaft rod 30, the mounting frame 23 moves downwards by replacing the hole expanding machine 3 under the driving of an air cylinder 21 on the lifting assembly 2, and the hole expanding drill bit 300 drills into a positioning hole to process and expand the positioning hole; after reaming, the cylinder 21 drives the lower reaming bit 300 to move upwards; then the servo motor 52 is driven, the positioning screw 50 drives the clamping assembly 6 to move towards the direction of the thread tapping machine 4, when the clamping assembly moves to a position below the thread tapping machine 4, the thread tapping machine 4 is started, the thread tapping machine 4 moves downwards under the driving of the lifting assembly 2, and the tapping drill 400 is inserted into the hole to form an internal thread on the inner wall of the hole; through adopting above-mentioned scheme, when carrying out the reaming tapping to spare part, only need start the positioning subassembly and can accomplish the adjustment of spare part position between reamer 3 and tapping machine, therefore only need carry out a clamping to the spare part, improved the convenience of spare part reaming tapping operation.

In practical application, a plurality of threaded holes which are not in the same straight line are sometimes formed in a part, and in order to further improve the convenience of reaming and tapping on the part, referring to fig. 2, a second positioning assembly 7 is arranged between a first positioning assembly 5 and a clamping assembly 6; the second positioning component 7 comprises a mounting seat 70, a positioning screw 71 and a positioning slide block 72; the bottom surface of the mounting seat 70 is fixedly connected with the positioning slide block 51; a second positioning chute 700 with an extending direction perpendicular to the extending direction of the first positioning chute 10 is arranged on one surface of the mounting seat 70 departing from the positioning slider 51; the positioning screw 71 is rotatably supported in the second positioning chute 700, and one end of the positioning screw penetrates through the second positioning chute 700; an annular handle 710 is fixedly connected to one end of the positioning screw rod 71 penetrating out of the second positioning chute 700; the positioning slide block 72 is arranged in the second positioning chute 700 and is in threaded connection with the positioning screw rod 71; the positioning slide block 72 is in sliding fit with the second positioning chute 700; the side of the clamping assembly 6 facing away from the side clamping plate 61 is fixedly connected with the positioning slide 72.

The second positioning component 7 is implemented according to the following principle: by rotating the handle 710, the positioning screw 71 rotates in the second positioning chute 700, so as to drive the positioning slider 72 to slide in the second clamping chute 600, and the positioning chute drives the clamping assembly 6 to slide on the mounting seat 70; through first positioning subassembly 5 and second positioning subassembly 7, can make spare part adjust in X axle and Y axle direction, every locating hole on the spare part in certain scope all is in reaming tapping process range, has further reduced the clamping number of times of spare part to the convenience of spare part reaming tapping operation has further been improved.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. A reaming tapping machine is characterized in that: the device comprises a workbench (1), a hole expanding machine (3) and a thread tapping machine (4) which are arranged on two sides of the workbench (1), a lifting assembly (2) which is arranged on the workbench (1) and respectively corresponds to the hole expanding machine (3) and the thread tapping machine (4) and is used for driving the hole expanding machine (3) and the thread tapping machine (4) to lift up and down, a clamping assembly (6) which is arranged on the workbench (1) and is used for clamping and fixing parts, and a first positioning assembly (5) which is arranged on the workbench (1) and is used for driving the clamping assembly (6) to slide linearly along the arrangement direction of the hole expanding machine (3) and the thread tapping machine (4); a driving module and a control module are arranged in the hole expanding machine (3) and the thread tapping machine (4); a reaming shaft lever (30) is vertically arranged at one end of the reaming machine (3) facing the workbench (1); a hole expanding drill bit (300) is arranged at one end of the hole expanding shaft rod (30) facing the workbench (1); a tapping shaft lever (40) is vertically arranged at one end of the thread tapping machine (4) facing the workbench (1); a tapping drill (400) is arranged at one end of the tapping shaft rod (40) facing the workbench (1).

2. The reaming tapping machine of claim 1, wherein: the lifting assembly (2) comprises a vertical seat (20), a cylinder (21), a guide block (22) and a mounting frame (23); the vertical seat (20) is arranged on the workbench (1) and is internally provided with an installation groove (200) extending along the length direction of the vertical seat (20); the cylinder (21) is arranged in the mounting groove (200) and the axis of the output end is parallel to the extending direction of the mounting groove (200); the guide block (22) is arranged in the mounting groove (200) and is in sliding fit with the mounting groove (200); the guide block (22) is fixedly connected with the output end of the air cylinder (21); a guide groove (201) which has an extending direction parallel to the extending direction of the mounting groove (200) and is communicated with the inside of the mounting groove (200) is arranged at a position, corresponding to the guide block (22), on the vertical seat (20); a connecting block (220) which is protruded out of the guide groove (201) and is matched with the guide groove (201) in a sliding way is fixedly connected at the position of the guide block (22) corresponding to the guide groove (201); the mounting frame (23) is fixedly connected with the connecting block (220); the hole expanding machine (3) and the thread tapping machine (4) are fixedly connected with the mounting frame (23).

3. The reaming tapping machine of claim 1, wherein: a first positioning chute (10) extending along the arrangement direction of the hole expanding machine (3) and the thread tapping machine (4) is formed in the workbench (1); the first positioning component (5) comprises a positioning screw rod (50) which is rotatably supported in the first positioning chute (10) and a positioning slide block (51) which is screwed on the positioning screw rod (50) and is in sliding fit with the first positioning chute (10); the clamping assembly is arranged on the position adjusting sliding block (51).

4. The reaming tapping machine of claim 1, wherein: the first positioning component (5) further comprises a servo motor (52) of which the output end is coaxially and fixedly connected to one end of the positioning screw rod (50).

5. The reaming tapping machine of claim 1, wherein: the clamping assembly (6) comprises a bottom plate (60), a side clamping plate (61), a clamping screw rod (62), the side clamping plate (61) and an adjusting block (63); the bottom plate (60) is arranged on the first adjusting component; the side clamping plate (61) is arranged on one surface of the bottom plate (60) departing from the first adjusting component; a movable clamping plate (64) with a plate surface opposite to the side clamping plate (61) is arranged on one side of the bottom plate (60) opposite to the side clamping plate (61); a clamping sliding chute (600) with the extending direction parallel to the arrangement direction of the side clamping plate (61) and the movable clamping plate (64) is arranged between the side clamping plate (61) and the movable clamping plate (64) on the bottom plate (60); the clamping screw rod (62) is rotatably supported in the clamping chute (600); the adjusting block (63) is screwed on the clamping screw rod (62) and is in sliding fit with the clamping chute (600).

6. The reaming tapping machine of claim 1, wherein: a second positioning component (7) is arranged between the first positioning component (5) and the clamping component (6); the second positioning assembly (7) comprises a mounting seat (70), a positioning screw rod (71) and a positioning sliding block (72); the mounting seat (70) is arranged on the first positioning component (5); a second positioning sliding groove (700) with the extending direction perpendicular to the arrangement direction of the hole expanding machine (3) and the thread tapping machine (4) is formed in the mounting seat (70); the positioning screw rod (71) is rotatably supported in the second positioning chute (700); the positioning slide block (72) is screwed on the positioning screw rod (71) and is in sliding fit with the second positioning sliding groove (700).

7. The reaming tapping machine of claim 2, wherein: two guide grooves (201) are symmetrically arranged on two sides of the vertical seat (20).

8. The reaming tapping machine of claim 5, wherein: limiting grooves (601) with the extending directions parallel to the extending direction of the clamping sliding groove (600) are symmetrically formed in the two sides, located on the clamping sliding groove (600), of the bottom plate (60); a limiting block (640) is arranged on the movable clamping plate (64) at a position corresponding to the limiting groove (601); the limiting block (640) is embedded in the limiting groove (601) and is in sliding fit with the limiting groove (601).