CN115233432B

CN115233432B - Movable vibration knife cutting machine

Info

Publication number: CN115233432B
Application number: CN202210827985.XA
Authority: CN
Inventors: 刘�文
Original assignee: Gbos Laser Inc
Current assignee: Gbos Laser Inc
Priority date: 2022-07-13
Filing date: 2022-07-13
Publication date: 2023-04-04
Anticipated expiration: 2042-07-13
Also published as: CN115233432A

Abstract

The invention relates to a movable type vibrating knife cutting machine which comprises a cutting table, wherein a cutting area is formed in the top surface of the cutting table in a concave mode, a vertical rod is fixed on the back surface of the cutting table, a projector is fixed on the vertical rod, two U-shaped frames are fixed in the cutting area, a U-shaped plate is arranged between the two U-shaped frames, a driving mechanism is arranged on one side, opposite to each other, of each U-shaped frame, a pressing roller is rotatably arranged in each U-shaped plate along the long edge of each U-shaped plate, and a color sensor facing materials on the cutting area is fixed on each U-shaped plate. The accessible presses the compression roller to place the cloth on the cutting area and carries out the roll extrusion and sweep, makes the cloth shake to its border along pressing the department to along with the roll extrusion of pressing the compression roller, when guaranteeing to place the cloth tiling on the cutting area and fixed, cooperating the border of color sensor discernment cloth, need not artifical manual smoothing and adjust fixed cloth, can smooth automatically and fix, efficiency is also high when the precision is high.

Description

Movable vibration knife cutting machine

Technical Field

The invention relates to the technical field of a vibration cutter cutting machine, in particular to a movable vibration cutter cutting machine.

Background

The vibration sword cutting machine is used for the flexible material cutting to get better selection tool, present but wide application in automotive interior cutting, the cutting of carpet pad, the clothing material cutting, the cutting of packaging material, furniture fabric cutting, advertising material cutting, the cutting of leather bag, trades such as combined material cutting, vibration sword cutting machine is used the trade very extensively, can join in marriage different cutters, the cutter that the different materials of cutting used also differs, it is more suitable to cut the vibration sword cutting for the leather sponge combined material, it is more suitable with pneumatic sword and circular knife cutting to cut the cloth, the cutting paper subsides can be with dragging the sword, the material that vibration sword cutting machine can cut is still very many anyway, for example: carbon fiber, glass fiber, cellucotton, prepreg cloth, aramid fiber, ceramic fiber, cloth, silk rings, leather, felt, carpet, sound-absorbing cotton, silica gel, rubber, kt board and the like.

In-process at cloth class material cutting, the position precision that the cloth was placed on the workstation is especially important, when the precision of workstation is high, the blade on the cutting blade seat can carry out the high accuracy and cut off, the precision can obtain great assurance certainly, slight error can lead to cutting off the reduction of precision, bring the loss for the mill, and the workstation of vibrations sword cutting machine among the prior art is after placing the cloth, generally rely on the manual work to smooth the cloth and adjust cloth fixed position, when comparatively troublesome, the precision still can not be guaranteed, based on this, this application provides a portable vibrations sword cutting machine in order to solve above-mentioned problem.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a movable vibration knife cutting machine, which has the advantage of improving the cutting precision and solves the problem that the precision cannot be ensured while the conventional vibration knife cutting machine is troublesome because the cloth is flattened and the cloth fixing position is adjusted manually.

In order to achieve the purpose, the invention provides the following technical scheme: the movable type vibrating knife cutting machine comprises a cutting table for placing materials and a cutting knife seat arranged above the cutting table and used for cutting the materials, wherein four movable wheels used for moving the whole equipment are arranged below the cutting table, and a moving mechanism used for driving the cutting knife seat to move along an X axis, a Y axis and a Z axis is arranged on the cutting table;

the top surface of the cutting table is recessed inwards to form a cutting area, the back surface of the cutting table is fixedly provided with a vertical rod, and a projector for projecting onto the cutting area is fixedly arranged on the vertical rod;

two U-shaped frames which are arranged in parallel are fixed in the cutting area, two U-shaped plates which can move linearly left and right are arranged between the two U-shaped frames, and driving mechanisms which respectively drive the two U-shaped plates to move oppositely or oppositely are arranged on the opposite sides of the two U-shaped frames;

the U-shaped plate is internally provided with a pressing roller which is used for pressing and holding materials in the cutting area along the long edge of the U-shaped plate, and a color sensor which faces the materials in the cutting area is fixed on the U-shaped plate.

Further, be equipped with U type mounting bracket in the U type frame, the rotating tube that rather than rotating through the bearing and being connected is all run through perpendicularly to the front and back both sides face of U type mounting bracket, two the one end that the rotating tube was carried on the back mutually is the closed form, press the compression roller suit to be located between two rotating tubes and the three is located same axis, two the one end that the rotating tube is relative is fixed with the both ends of pressing the compression roller respectively, two color sensor is located one side that two pressure rollers carried on the back mutually respectively.

Furthermore, a plurality of telescopic rods which are vertically fixed with the inner top wall of the U-shaped frame are vertically fixed on the top surface of the U-shaped mounting frame, and extrusion springs are movably sleeved on the telescopic rods.

Further, two the relative one end of rotating-tube respectively with press the both ends intercommunication of compression roller and fixed, the left side of cutting bed is fixed with high pressure positive blower, high pressure positive blower's air-out end is connected with the air-out hose, the other end of air-out hose run through the U type frame that is located the rear and with be located the left rear rotating-tube intercommunication, press the compression roller and be inside hollow cylinder, a plurality of exhaust holes that are the annular array and distribute are seted up to its surface.

Further, be located the rear U type frame is gone up and has been seted up rectangular through-hole along its long limit direction, the air-out hose runs through rectangular through-hole and linear movement about doing in rectangular through-hole.

Furthermore, adjusting bins are fixed on the two sides of the U-shaped frames, the driving mechanism is arranged in the adjusting bins, guide rods are vertically fixed between the inner walls of the left side and the right side of each U-shaped frame, two movable blocks are slidably sleeved on the two guide rods, the U-shaped plates are fixed between the two corresponding movable blocks, the driving mechanism comprises a driving motor fixed in the adjusting bins, a threaded rod fixed with an output shaft of the driving motor, the other end of the threaded rod is rotatably connected with the inner wall of the adjusting bins through a bearing, and a movable block movably sleeved on the threaded rod and in threaded connection with the threaded rod, a sliding block is fixed on the movable block, a sliding rail slidably connected with the sliding block is fixed on the inner wall of the adjusting bins, a connecting rod penetrating through the U-shaped frames and fixed with the movable blocks is fixed on one side face of each movable block facing the U-shaped frames, and the two connecting rods are fixed with the two movable blocks on the left back and the right front respectively.

Furthermore, one side of the adjusting bin facing the U-shaped frame is in a missing shape, a limiting strip hole is formed in the U-shaped frame along the long edge direction of the U-shaped frame, the connecting rod penetrates through the limiting strip hole and moves linearly leftwards and rightwards in the connecting rod, and a threaded through hole for the threaded rod to penetrate through and is in threaded connection with the threaded rod is formed in the moving block.

Further, one side of cutting blade holder towards the cutting area is fixed with U type fixing base, vertically in the U type fixing base be fixed with two gag lever posts, two slide the cover on the gag lever post and be equipped with a mount pad, the movable sleeve is equipped with two and is located the buffer spring of both sides about the mount pad respectively on the gag lever post, vertically run through on the mount pad have one rather than fixed setting-out pen.

Furthermore, the mounting seat is provided with two limiting holes, and the two limiting rods respectively penetrate through the two limiting holes and are in clearance fit with the limiting holes.

Compared with the prior art, the technical scheme of the application has the following beneficial effects:

this portable vibrations sword cutting machine, the accessible presses the compression roller to place the cloth on the cutting area roll extrusion and sweep, makes the cloth shake to its border along pressing the department to along with the roll extrusion of pressing the compression roller, ensure when placing the cloth tiling on the cutting area and fixed, cooperate the border of color sensor discernment cloth, need not artifical manual smoothing and adjust fixed cloth, can smooth automatically and fix, efficiency is also high when the precision is high.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic top view of the present invention;

FIG. 3 is an enlarged view of A in FIG. 2 according to the present invention;

FIG. 4 is a schematic view of the left side structure of the U-shaped plate of the present invention;

FIG. 5 is a schematic view of the left side of the present invention;

FIG. 6 is an enlarged view of B in FIG. 5 according to the present invention.

In the figure: 1. cutting the table; 2. a high pressure fan; 3. an air outlet hose; 4. erecting a rod; 5. a projector; 6. A Z-axis linear module; 7. a movable table; 8. an X-axis linear module; 9. a cutter seat; 10. a Y-axis linear module; 11. a slider; 12. a moving block; 13. a cutting zone; 14. a movable block; 15. a U-shaped plate; 16. a guide bar; 17. a threaded rod; 18. a slide rail; 19. a drive motor; 20. a regulating bin; 21. a U-shaped frame; 22. A telescopic rod; 23. extruding the spring; 24. a U-shaped mounting frame; 25. rotating the tube; 26. pressing the roller; 27. an air exhaust hole; 28. a color sensor; 29. a line drawing pen; 30. a U-shaped fixed seat; 31. a limiting rod; 32. a buffer spring; 33. a mounting seat; 34. a connecting rod; 35. a connecting seat.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

Referring to fig. 1-2, a mobile vibration knife cutting machine in the prior art includes a cutting table 1 for placing cloth and a cutting knife seat 9 arranged above the cutting table 1 for cutting the cloth, four moving wheels for moving the whole equipment are arranged below the cutting table 1, the four moving wheels are distributed at four corners of the bottom surface of the cutting table 1, the whole equipment is moved by the moving wheels, a moving mechanism for driving the cutting knife seat 9X-axis, the Y-axis and the Z-axis to move is arranged on the cutting table 1, wherein the moving mechanism includes an X-axis linear module 8, a Y-axis linear module 10 and a Z-axis linear module 6,X shaft linear module 8 fixed on the cutting table 1, a movable table 7,Z shaft linear module 6 driven to move left and right is fixed on a movable table 7, a connecting seat 35 driven by the Z-axis linear module 6 to move front and back is arranged on the left side of the Z-axis linear module 10 fixed on the connecting seat 35, and the cutting knife seat 9 is driven by the Y-axis linear module 10 to move up and down.

During the cutting, through placing the cloth on cutting bed 1, then cutting blade holder 9 is being moved the cloth top by the moving mechanism drive and is cutting the cloth, it needs to explain that cutting blade holder 9 is cutting blade holder 9 that the conventional vibrations sword cutting machine that prior art publicly known had to cut the cloth among the prior art, and the text is no longer repeated its specific structure and theory of operation.

Referring to fig. 1-6, in the present invention, in order to cut the fabric more accurately, a cutting area 13 is formed by recessing the top surface of the cutting table 1, a vertical rod 4 is fixed on the back surface of the cutting table 1, a projector 5 for projecting onto the cutting area 13 is fixed on the vertical rod 4, and an area to be cut is projected onto the fabric through the projector 5, so as to facilitate the cutting of the cutting tool holder 9, it should be noted that a visual sensor facing the fabric is fixed on the cutting tool holder 9, and the cutting blade can be cut according to the projected area.

Meanwhile, two U-shaped frames 21 which are arranged in parallel front and back are fixed in the cutting area 13, two U-shaped plates 15 which can move linearly left and right are arranged between the two U-shaped frames 21, a driving mechanism which respectively drives the two U-shaped plates 15 to move oppositely or oppositely is arranged on one side of each of the two U-shaped frames 21, pressing rollers 26 which are used for pressing and holding the cloth on the cutting area 13 are arranged in the U-shaped plates 15 in a rotating mode along the long sides of the U-shaped frames, color sensors 28 which face the cloth on the cutting area 13 are fixed on the U-shaped plates 15, the driving mechanisms drive the two U-shaped plates 15 to move oppositely or oppositely, the pressing rollers 26 are operated to move, the two pressing rollers 26 can press the edges of the cloth, the cloth is ensured to be stably fixed, it is required to be stated that when the cloth is placed in the cutting area 13, the positions where the cloth is placed are different, the pressing rollers 26 judge whether the cloth is pressed on the cloth through the color sensors 28, when the cloth moves, if the cloth covers the lower square of the color sensors 28 in the U-shaped plates 15, the color sensors 28 can sense the color change, then the position of the material is judged, the U-pressing rollers are stopped, the U-shaped plates 15 can move, the edges can be pressed, the edges of the cloth can be flatly fixed, and the cloth can be pressed on the cloth, and the cloth can be pressed.

In order to enable the pressing roller 26 to have appropriate force when pressing the cloth and better smooth the cloth, a U-shaped mounting frame 24 is arranged in the U-shaped frame 21, rotating pipes 25 rotatably connected with the U-shaped mounting frame 24 through bearings vertically penetrate through the front side surface and the rear side surface of the U-shaped mounting frame 24, the back ends of the two rotating pipes 25 are closed, the pressing roller 26 is sleeved between the two rotating pipes 25, the three rotating pipes are located on the same central axis, the opposite ends of the two rotating pipes 25 are respectively fixed to the two end portions of the pressing roller 26, the two color sensors 28 are respectively located on the back sides of the two pressing rollers 26, a plurality of telescopic rods 22 vertically fixed to the inner top wall of the U-shaped mounting frame 21 are vertically fixed to the top surface of the U-shaped mounting frame 24, and the pressing roller 26 is movably sleeved with an extrusion spring 23, so that the pressing spring 23 is pressed and held by the tension of the extrusion spring 23 in the process of pressing the pressing roller 26 pressing the cloth, and the pressing roller 26 can better smooth the cloth in the rolling process.

It should be noted that the telescopic rod 22 is composed of a sleeve bin and a moving rod, one end of the moving rod penetrates through and extends into the sleeve bin, a limiting block is fixed at the end of the moving rod, a through hole for the moving rod to be inserted into and in clearance fit with the moving rod is formed in the sleeve bin, and the moving rod is prevented from being separated from the sleeve bin in the moving process by the limiting block.

The opposite ends of two rotating pipes 25 are respectively communicated and fixed with two ends of a pressing roller 26, a high-pressure fan 2 is fixed on the left side of a cutting table 1, an air outlet end of the high-pressure fan 2 is connected with an air outlet hose 3, the other end of the air outlet hose 3 penetrates through a U-shaped frame 21 located behind and is communicated with the rotating pipe 25 located behind the left side, the pressing roller 26 is a hollow cylinder, a plurality of air outlet holes 27 distributed in an annular array are formed in the outer surface of the pressing roller, a long through hole is formed in the U-shaped frame 21 located behind along the long side direction of the long through hole, the air outlet hose 3 penetrates through the long through hole and moves linearly left and right in the long through hole, the left pressing roller 26 can be directly arranged in the middle of cloth, then the high-pressure fan 2 is started, high-pressure air flow enters the pressing roller 26 and is blown out through the air outlet holes 27 distributed in the annular array on the pressing roller 26, then the upper surface of the cloth is blown, when the other side of the cloth is not pressed, the cloth can be shaken up, the cloth, one side of the cloth can be blown out while sweeping and rolling, the cloth, the rolling press the cloth, the cutting accuracy of the cloth can be improved by a cutter holder 9, and the cutting accuracy of the cloth can be improved.

For the point that the U-shaped frames 21 are driven to move, adjusting bins 20 are fixed on the opposite sides of the two U-shaped frames 21, a driving mechanism is arranged in the adjusting bins 20, one side of each adjusting bin 20 facing the U-shaped frame 21 is in an absent state, guide rods 16 are vertically fixed between the inner walls of the left side and the right side of each U-shaped frame 21, two movable blocks 14 are sleeved on the two guide rods 16 in a sliding mode, a U-shaped plate 15 is fixed between the two corresponding movable blocks 14, the driving mechanism comprises a driving motor 19 fixed in the adjusting bins 20, a threaded rod 17 fixed with an output shaft of the driving motor 19, the other end of the threaded rod 17 is rotatably connected with the inner wall of each adjusting bin 20 through a bearing, a movable block 12 movably sleeved on the threaded rod 17 and in threaded connection with the threaded rod 17, a threaded through hole for the threaded rod 17 to penetrate through and in threaded connection with the threaded rod 17 is formed in the movable block 12, a sliding block 11 is fixed on the movable block 12, a sliding rail 18 slidably connected with the sliding block 11 is fixed on the inner wall of each adjusting bin 20, a connecting rod 14 is fixed on one side face of each U-shaped frame 21, a connecting rod 34 fixed with the U-shaped frame 21 and a long hole formed in the direction, a left side and a right side hole is formed in the connecting rod 34, and two long side of each connecting rod 14, and two long connecting rod 14 are fixed in the left side and two long side of the left side and the left side.

During operation, the driving motor 19 is started to enable the threaded rod 17 to rotate, under the action of limiting sliding of the sliding block 11 and the sliding rail 18, the moving block 12 can be connected with the threaded rod 17 through the threaded through hole in a threaded mode to move left and right, the connecting rod 34 is driven to move left and right, the moving block 14 is further driven to move, and therefore moving of the U-shaped plate U-shaped frame is achieved.

In addition, a U-shaped fixing seat 30 is fixed on one side of the cutting tool holder 9 facing the cutting area 13, two limiting rods 31 are vertically fixed in the U-shaped fixing seat 30, a mounting seat 33 is slidably sleeved on the two limiting rods 31, two limiting holes are formed in the mounting seat 33, the two limiting rods 31 respectively penetrate through the two limiting holes and are in clearance fit with the two limiting holes, two buffer springs 32 are movably sleeved on the limiting rods 31 and are respectively located on the upper side and the lower side of the mounting seat 33, a line drawing pen 29 fixed with the mounting seat 33 vertically penetrates through the mounting seat 33, the line drawing pen 29 penetrates through the mounting seat 33, a cylindrical through hole for the line drawing pen 29 to penetrate through is formed in the mounting seat 33, a threaded hole vertically communicated with the cylindrical through hole is formed in one side of the mounting seat 33, the screw rod is screwed into the threaded hole, one end of the screw rod enters the cylindrical through hole and forms abutting connection with the line drawing pen 29, and accordingly fixing of the line drawing pen 29 is achieved, in the actual use process, the cutting tool holder 9 is driven to move down, cloth 29, and later-cutting is convenient and accurate later-stage cutting is achieved.

The control mode of the invention is controlled by a controller, the control circuit of the controller can be realized by simple programming of a person skilled in the art, the supply of the power supply also belongs to the common knowledge in the field, and the invention is mainly used for protecting mechanical devices, so the control mode and the circuit connection are not explained in detail in the invention.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. Portable vibrations sword cutting machine includes:

the cutting table (1) is used for placing materials, and four moving wheels used for moving the whole equipment are arranged below the cutting table (1);

the cutting machine comprises a cutting tool apron (9) arranged above a cutting table (1) and used for cutting materials, wherein the cutting table (1) is provided with a moving mechanism for driving the cutting tool apron (9) to move along an X axis, a Y axis and a Z axis;

the method is characterized in that: the top surface of the cutting table (1) is recessed inwards to form a cutting area (13), the back surface of the cutting table (1) is fixedly provided with an upright rod (4), and a projector (5) for projecting onto the cutting area (13) is fixedly arranged on the upright rod (4);

two U-shaped frames (21) which are arranged in parallel in the front and back are fixed in the cutting area (13), two U-shaped plates (15) which can move linearly left and right are arranged between the two U-shaped frames (21), and driving mechanisms which respectively drive the two U-shaped plates (15) to move oppositely or back to back are arranged on the opposite sides of the two U-shaped frames (21);

a pressing roller (26) used for pressing and holding the materials on the cutting area (13) is rotatably arranged in the U-shaped plate (15) along the long edge of the U-shaped plate, and a color sensor (28) facing the materials on the cutting area (13) is fixed on the U-shaped plate (15);

a U-shaped mounting frame (24) is arranged in the U-shaped frame (21), rotating pipes (25) which are rotatably connected with the U-shaped mounting frame through bearings vertically penetrate through the front side surface and the rear side surface of the U-shaped mounting frame (24), the opposite ends of the two rotating pipes (25) are closed, the pressing rollers (26) are sleeved between the two rotating pipes (25), the pressing rollers (26) are located in the same central axis, the opposite ends of the two rotating pipes (25) are respectively fixed with the two end parts of the pressing rollers (26), and the two color sensors (28) are respectively located on the opposite sides of the two pressing rollers (26);

a plurality of telescopic rods (22) vertically fixed with the inner top wall of the U-shaped frame (21) are vertically fixed on the top surface of the U-shaped mounting frame (24), and extrusion springs (23) are movably sleeved on the telescopic rods (22);

the opposite ends of the two rotating pipes (25) are respectively communicated and fixed with two ends of a pressing roller (26), a high-pressure fan (2) is fixed on the left side of the cutting table (1), an air outlet end of the high-pressure fan (2) is connected with an air outlet hose (3), the other end of the air outlet hose (3) penetrates through a U-shaped frame (21) located behind and is communicated with the rotating pipe (25) located behind the left side, the pressing roller (26) is a hollow cylinder, and a plurality of air exhaust holes (27) distributed in an annular array are formed in the outer surface of the pressing roller (26);

lie in the rear U type frame (21) is gone up and has been seted up rectangular through-hole along its long limit direction, air-out hose (3) run through rectangular through-hole and about linear movement is done in rectangular through-hole.

2. The mobile vibratory knife cutter of claim 1 wherein: adjusting bins (20) are fixed on the two sides, opposite to each other, of the U-shaped frames (21), driving mechanisms are arranged in the adjusting bins (20), guide rods (16) are perpendicularly fixed between the inner walls of the left side and the right side of each U-shaped frame (21), two movable blocks (14) are sleeved on the two guide rods (16) in a sliding mode, the U-shaped plates (15) are fixed between the two corresponding movable blocks (14), each driving mechanism comprises a driving motor (19) fixed in each adjusting bin (20), a threaded rod (17) fixed to an output shaft of the driving motor (19) and connected with the inner wall of each adjusting bin (20) through bearings in a rotating mode, a movable block (12) movably sleeved on the threaded rod (17) and connected with the threaded rod (17) in a threaded mode, a sliding block (11) is fixed to the movable block (12), sliding rails (18) connected with the sliding blocks (11) are fixed to the inner walls of the adjusting bins (20), one side, facing the U-shaped frames (21), of each movable block (14) is fixed with a connecting rod (34) penetrating through the U-shaped frames (14) and fixed to the corresponding movable blocks (14), and two connecting rods (34) are fixed to the left side and the rear side of the two movable blocks (14).

3. The mobile vibratory knife cutter of claim 2 wherein: one side of the adjusting bin (20) facing the U-shaped frame (21) is in a missing shape, a limiting strip hole is formed in the U-shaped frame (21) along the long side direction of the U-shaped frame, the connecting rod (34) penetrates through the limiting strip hole and moves linearly left and right in the limiting strip hole, and a threaded through hole for the threaded rod (17) to penetrate through and is in threaded connection with the threaded rod (17) is formed in the moving block (12).

4. The mobile vibratory knife cutter of any one of claims 1 or 3 wherein: cutting blade holder (9) are fixed with U type fixing base (30) towards one side of cutting area (13), vertical two gag lever post (31) of being fixed with in U type fixing base (30), two sliding sleeve is equipped with a mount pad (33) on gag lever post (31), the movable sleeve is equipped with two and is located buffer spring (32) of both sides about mount pad (33) respectively on gag lever post (31), vertical running through has one rather than fixed setting-out pen (29) on mount pad (33).

5. The mobile vibratory knife cutter of claim 4 wherein: the mounting seat (33) is provided with two limiting holes, and the two limiting rods (31) penetrate through the two limiting holes respectively and are in clearance fit with the limiting holes.