CN111673550A

CN111673550A - Automatic turnover type knife sharpener

Info

Publication number: CN111673550A
Application number: CN202010625441.6A
Authority: CN
Inventors: 倪立连
Original assignee: Shandong Lilian Intelligent Equipment Co ltd
Current assignee: Shandong Lilian Intelligent Equipment Co ltd
Priority date: 2020-07-02
Filing date: 2020-07-02
Publication date: 2020-09-18
Anticipated expiration: 2040-07-02
Also published as: CN111673550B

Abstract

The invention discloses an automatic turnover type knife sharpener, which comprises a bottom plate, a top plate and a grinding mechanism, wherein a supporting plate consists of two supporting guide plates and a transition plate, the two supporting guide plates are right-angled in the horizontal direction, continuous racks are uniformly distributed on the same sides of the two supporting guide plates and the transition plate, a driven shaft is fixed at the upper end of the transition plate, a clamping mechanism is fixed at the top end of the driven shaft, the grinding mechanism comprises a driving shaft, a grinding wheel, a first driving gear and a second driving gear, which are sequentially fixed on the driving shaft from top to bottom, a bidirectional motor is fixed at the bottom end of the driving shaft, under the common cooperation of the second driving gear and the racks on the side wall of the supporting plate, the grinding wheel can move from one end of one supporting guide plate to one end of the other supporting guide plate, meanwhile, two surfaces of a blade can be ground, meanwhile, the automatic overturning of the blade can be realized in the moving process, and the effect of killing two birds with one stone is achieved.

Description

Automatic turnover type knife sharpener

Technical Field

The invention relates to the technical field of knife sharpeners, in particular to an automatic turnover type knife sharpener.

Background

The knife sharpener is used for trimming the blade, compared with the blade obtained by manual sharpening, the service strength of the blade is increased, the service life of the blade and the processing capacity of the blade are correspondingly improved, and therefore the knife sharpener is an essential special device for industries such as printing, papermaking, packaging, plastic leather, woodworking and the like. After the blade works for a long time, the sharpness of the blade point is reduced or the blade is abraded, so the blade needs to be sharpened again, and different machine types can be selected according to the type and the size of the blade to sharpen the blade.

The existing knife sharpener generally comprises a motor, a grinding wheel and a knife rest clamping seat, wherein the grinding wheel is driven by the motor to rotate, the knife rest clamping seat is used for fixing a cutter, only one surface of the blade can be ground in the grinding process, when another knife surface of the blade needs to be ground, the blade needs to be detached from the knife rest clamping seat to be installed again, the knife surface which is not ground is just opposite to the grinding wheel, and then the knife sharpener is started to grind the blade again, so that the labor capacity of workers is increased, and the grinding efficiency is also reduced.

Disclosure of Invention

The invention aims to provide an automatic turnover type knife sharpener so as to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: an automatic turnover type knife sharpener comprises a bottom plate, a top plate, a supporting plate and a grinding mechanism, wherein the top plate is fixed above the bottom plate and is parallel to the bottom plate, the supporting plate is horizontally fixed between the bottom plate and the top plate, the supporting plate is composed of two supporting guide plates and a transition plate used for connecting the two supporting guide plates, the two supporting guide plates are in a right angle in the horizontal direction, the transition plate is of an arc-shaped structure, the transition plate and the two supporting guide plates are integrally formed, continuous racks are uniformly distributed on the same sides of the two supporting guide plates and the transition plate, a driven shaft is vertically fixed at the upper end of the transition plate through a bearing, a clamping mechanism used for fixing a blade is fixed at the top end of the driven shaft, a driven gear is fixed below the clamping mechanism, the transition plate is one fourth of the driven gear, a right-angle slide rail I with a T-shaped cross section is arranged at the bottom end of the top, the shape of the first right-angle sliding rail is the same as that of the supporting plate, the first right-angle sliding rail is connected with a first sliding block in a sliding mode, and the bottom end of the first sliding block is rotatably connected with a polishing mechanism;

the grinding mechanism comprises a driving shaft parallel to the driven shaft, a grinding wheel, a first driving gear and a second driving gear, wherein the grinding wheel is sequentially fixed on the driving shaft from top to bottom and corresponds to the blade, the first driving gear is located on the same horizontal plane with the driven shaft and is matched with the driven shaft, the second driving gear is meshed with the side wall of the supporting plate, and a bidirectional motor is fixed at the bottom end of the driving shaft through a coupler.

Preferably, the driven shaft is located below the driven gear and is fixed with a fixing ring in rotary connection with the driven shaft, and the fixing ring is fixed with a locking mechanism.

Preferably, locking mechanism is including fixing on the stationary ring lateral wall and opening decurrent guide sleeve, fixing the permanent magnet piece on the inside top of guide sleeve, fixing on the permanent magnet piece and along the flexible fixed spring of guide sleeve length direction and fix the electromagnet piece on the fixed spring bottom, cross the cab apron up end and seted up two mutually perpendicular and all with the spacing draw-in groove of electromagnet piece looks adaptation, and two spacing draw-in grooves correspond respectively and support the deflector parallel with two.

Preferably, the clamping mechanism comprises a clamping block, a fixing groove formed in the center of the upper end of the clamping block, two first fixing holes formed in the upper end of the clamping block and symmetrical with respect to the fixing groove, a clamping baffle, a clamping pressure plate fixed at the bottom end of the clamping baffle, two fixing holes formed in the clamping baffle and corresponding to the first fixing holes one by one, and fixing bolts penetrating through the second fixing holes and connected with the first fixing holes in a threaded manner.

Preferably, the inner wall of the fixed groove is provided with a layer of protective pad.

Preferably, the upper end of the second driving gear is rotatably connected with a connecting block, one side, close to the supporting plate, of the connecting block is connected with a connecting rod, one end, far away from the connecting block, of the connecting rod is hinged with a second sliding block, and the second sliding block is connected with a second right-angle sliding rail which is arranged on the supporting plate and is in the same shape as the first right-angle sliding rail in a sliding mode.

Compared with the prior art, the invention has the beneficial effects that:

(1) when the double-direction grinding machine is used, the double-direction motor is started, the double-direction motor drives the driving shaft to rotate, the driving gear II on the driving shaft is meshed and connected with the rack on the side wall of the supporting plate, so that the driving gear II moves along the side wall of the supporting plate, the driving shaft moves under the action of the first sliding block and the second sliding block while rotating and simultaneously moves correspondingly along the first right-angle sliding rail and the second right-angle sliding rail from one end to the other end of the supporting plate, the driving shaft automatically drives the grinding wheel to move along one knife face edge of the blade to be ground in the moving process, when the driving gear II on the driving shaft leaves the supporting guide plate and enters the transition plate, the locking mechanism is unlocked to the driven shaft, meanwhile, the driving gear I starts to be meshed with the driven gear, and when the driving gear II on the driving shaft moves from, at the moment, the driving gear on the driving shaft just rotates one fourth of the driven gear from the process of meshing with the driven gear to just disengaging from the driven gear, so that the driven shaft rotates 90 degrees clockwise, further, the blade at the upper end of the driven shaft also rotates 90 degrees (namely, the blade rotates from the position above one supporting guide plate to the position above the other supporting guide plate), and the non-polished knife face is opposite to one side of the rack, the automatic turning function of the blade is realized, when the driving shaft leaves the transition plate, the driving shaft moves to the other supporting guide plate and moves to the end part along the length direction of the supporting guide plate (when the driving shaft leaves the transition plate to enter the other supporting guide plate, the locking mechanism locks the driving shaft), and the grinding wheel performs edge moving and polishing on the non-polished knife face of the knife blade, thereby realized the effect of two-sided polishing, then started the reverse rotation of two-way motor, made polishing mechanism return initial position department, in the in-process that returns, its operation is the same with above-mentioned principle.

(2) The clamping mechanism comprises a clamping block, a fixing groove arranged at the central position of the upper end of the clamping block, two fixing holes I which are arranged at the upper end of the clamping block and are symmetrical relative to the fixing groove, a clamping baffle plate, a clamping pressure plate fixed at the bottom end of the clamping baffle plate, fixing holes II which are arranged on the clamping baffle plate and correspond to the fixing holes I one by one, and fixing bolts which penetrate through the fixing holes II and are in threaded connection with the fixing holes I, when the clamping mechanism is used, a cutter handle of a blade is clamped on the fixing groove on the clamping block, the length of the blade is parallel to that of one of the supporting guide plates, then the clamping pressure plate on the clamping baffle plate is abutted against the cutter handle of the blade through the fixing bolt, the fixing of the blade is completed, and the depth of the clamping pressure plate extending into the fixing groove is indirectly adjusted by adjusting the extension of the fixing bolt extending into the first fixing hole, so that the fixing of the tool handles with different sizes is met.

Therefore, the two surfaces of the blade can be polished while the grinding wheel moves from one end of one of the supporting guide plates to one end of the other supporting guide plate under the condition that the second driving gear and the rack on the side wall of the supporting plate are matched together, polishing efficiency is improved, automatic overturning of the blade can be achieved in the moving process, and the effect of killing two birds with one stone is achieved.

Drawings

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

FIG. 2 is a side view of the clamping mechanism of FIG. 1 in the direction A-A;

FIG. 3 is a top view of the support plate construction;

FIG. 4 is an enlarged view of the structure of the portion B in FIG. 1;

FIG. 5 is an enlarged view of a portion C of FIG. 1 (a view illustrating the structure of a clamping mechanism);

fig. 6 is a schematic structural view of the locking mechanism.

In the figure: 1. a base plate; 2. a top plate; 3. a support plate; 301. supporting the guide plate; 302. a transition plate; 4. a drive shaft; 5. driving a gear I; 6. driving a gear II; 7. a grinding wheel; 8. a first sliding block; 9. a driven shaft; 10. a driven gear; 11. a first right-angle slide rail; 12. a bi-directional motor; 13. connecting blocks; 14. a connecting rod; 15. a second sliding block; 16. a right-angle slide rail II; 17. a limiting clamping groove; 18. a fixing ring; 19. a locking mechanism; 1901. a guide sleeve; 1902. permanent magnet blocks; 1903. fixing the spring; 1904. an electromagnet block; 20. a clamping mechanism; 201. a clamping block; 202. fixing the groove; 203. a first fixing hole; 204. clamping the baffle; 205. clamping the pressing plate; 206. a second fixing hole; 207. fixing the bolt; 21. a protective pad; 22. a blade.

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 derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-6, an embodiment of the present invention is shown: an automatic turnover knife sharpener comprises a bottom plate 1, a top plate 2 fixed above the bottom plate 1 and parallel to the bottom plate 1, a supporting plate 3 and a grinding mechanism fixed between the bottom plate 1 and the top plate 2 horizontally, wherein the supporting plate 3 is composed of two supporting guide plates 301 and a transition plate 302 used for connecting the two supporting guide plates 301, the two supporting guide plates 301 are right-angled in the horizontal direction, the transition plate 302 is of an arc-shaped structure, the transition plate 302 and the two supporting guide plates 301 are integrally formed, two same sides of the supporting guide plates 301 and the transition plate 302 are both uniformly distributed with continuous racks, the upper end of the transition plate 302 is vertically fixed with a driven shaft 9 through a bearing, the top end of the driven shaft 9 is fixed with a clamping mechanism 20 used for fixing a blade 22, the driven shaft 9 is fixed with a driven gear 10 below the clamping mechanism 20, the transition plate 302 is one fourth of the driven gear 10, when the second driving gear 6 on the driving shaft 4 moves from one end of the transition plate 302 to the other end of the transition plate 302, in this case, it is exactly the process that the first driving gear 5 on the driving shaft 4 is meshed with the driven gear 10 to just separate from the driven gear 10, and the driven gear 10 rotates by a quarter, so that the driven shaft 9 rotates by 90 degrees clockwise, further the blade 22 at the upper end of the driven shaft 9 also rotates by 90 degrees (i.e. the blade 22 rotates from above one supporting guide plate 301 to above the other supporting guide plate 301), the automatic turning function of the blade 22 is realized, so that the two surfaces of the blade 22 can be ground when the grinding wheel 7 moves from one end of one supporting guide plate 301 to one end of the other supporting guide plate 301 under the cooperation of the second driving gear 6 and the rack on the side wall of the supporting plate 3, the polishing efficiency is improved, a right-angle sliding rail I11 with a T-shaped section is arranged at the bottom end of the top plate 2, the shape of the right-angle sliding rail I11 is the same as that of the supporting plate 3, a sliding block I8 is connected in the right-angle sliding rail I11 in a sliding mode, and the bottom end of the sliding block I8 is rotatably connected with a polishing mechanism;

the grinding mechanism comprises a driving shaft 4 parallel to the driven shaft 9, a grinding wheel 7, a first driving gear 5 and a second driving gear 6, wherein the grinding wheel 7 is sequentially fixed on the driving shaft 4 from top to bottom and corresponds to the blade 22, the first driving gear is located on the same horizontal plane with the driven shaft 9 and is matched with the driven shaft 9, the second driving gear is meshed with the side wall of the supporting plate 3, and the bottom end of the driving shaft 4 is fixedly provided with a bidirectional motor 12 through a coupler.

Further, the driven shaft 9 is located below the driven gear 10 and is fixed with a fixing ring 18 rotatably connected with the driven shaft 9, and a locking mechanism 19 is fixed on the fixing ring 18, and the blade 22 is fixed through the locking mechanism 19, so that the driven shaft 9 is prevented from driving the blade 22 to deviate in the process that the grinding wheel 7 polishes the blade 22 while moving, and the polishing effect is ensured.

Further, the locking mechanism 19 includes a guide sleeve 1901 fixed on a side wall of the fixing ring 18 and having a downward opening, a permanent magnet block 1902 fixed on an inner top end of the guide sleeve 1901, a fixing spring 1903 fixed on the permanent magnet block 1902 and extending along a length direction of the guide sleeve 1901, and an electromagnet block 1904 fixed on a bottom end of the fixing spring 1903, wherein two limit slots 17 perpendicular to each other and adapted to the electromagnet block 1904 are formed on an upper end surface of the transition plate 302, and the two limit slots 17 are respectively parallel to the two support guide plates 301, in this embodiment, magnetism of the electromagnet block 1904 is opposite to that of the permanent magnet block 1904, so that the electromagnet block 1904 generates magnetism under the power-on condition and is opposite to that of the permanent magnet block 1902, at this time, an attractive force is generated between the electromagnet block 1904 and the permanent magnet block 1902, and at this time, the electromagnet block 1904 can overcome the tensile force of the fixing spring 1903 and move away from the permanent magnet block 1902 along an inner wall of the guide sleeve 1901 by separating from the permanent magnet block 1902 In addition, the bottom port of the guide sleeve 1901 is fitted to the upper end face of the transition plate 302, when the blade 22 on the driven shaft 9 is located directly above one of the supporting guide plates 301, the electromagnet 1904 on the locking mechanism 19 is powered off and sinks into the limit slot 17 under the action of the fixed spring 1903, so as to lock the driven shaft 9, when the driven shaft 9 is rotated, and the electromagnet 1904 is powered on, the electromagnet 1904 can move away from the limit slot 17 to the permanent magnet 1902 along the inner wall of the guide sleeve 1901 under the action of suction and overcoming the tension of the fixed spring 1903, so that the driven shaft 9 rotates, the driven shaft 9 rotates 90 ° clockwise until the blade 22 located at the upper end of the driven shaft overturns to the position directly above the other supporting guide plate 301, and meanwhile, the locking mechanism 19 is located just above the upper end of the other limit slot 17, and then the electromagnet 1904 is powered off, electromagnet 1904 after the outage sinks into spacing draw-in groove 17 under the effect of fixed spring 1903 to lock driven shaft 9 once more, therefore, prevent that emery wheel 7 from driving blade 22 and taking place to rotate and influence the effect of polishing at the in-process driven shaft 9 of polishing to blade 22.

Further, the clamping mechanism 20 includes a clamping block 201, a fixing groove 202 formed at the central position of the upper end of the clamping block 201, two first fixing holes 203 formed at the upper end of the clamping block 201 and symmetrical with respect to the fixing groove 202, a clamping baffle 204, a clamping pressure plate 205 fixed at the bottom end of the clamping baffle 204, two second fixing holes 206 formed on the clamping baffle 204 and corresponding to the first fixing holes 203 one by one, and a fixing bolt 207 penetrating through the second fixing holes 206 and threadedly connected with the first fixing holes 203, when in use, the shank of the blade 22 is clamped on the fixing groove 202 on the clamping block 201, the length of the blade 22 is parallel to the length of one of the supporting guide plates 301, then the clamping pressure plate 205 on the clamping baffle 204 is abutted on the shank of the blade 22 through the fixing bolt 207, that is the blade 22 is fixed, and the depth of the clamping pressure plate 205 extending into the fixing groove 202 is indirectly adjusted by adjusting the extension of the fixing bolt 207 extending into the first fixing hole 203, thereby satisfying the fixation of the tool shanks with different sizes.

Further, a layer of protection pad 21 is disposed on the inner wall of the fixing groove 202.

Further, the upper end of the second driving gear 6 is rotatably connected with a connecting block 13, one side, close to the supporting plate 3, of the connecting block 13 is connected with a connecting rod 14, one end, far away from the connecting block 13, of the connecting rod 14 is hinged with a second sliding block 15, the second sliding block 15 is in sliding connection with a second right-angle sliding rail 16 which is arranged on the supporting plate 3 and is identical to the first right-angle sliding rail 11 in shape, the connecting block 13, the connecting rod 14 and the second sliding block 15 play a role in supporting a grinding mechanism, and under the common cooperation of the connecting block 13, the connecting rod 14, the second sliding block 15, the second right-angle sliding rail 16, the first right-angle sliding rail 11.

The working principle is as follows: when the grinding device is used, an external power supply is connected, the grinding mechanism is located at one end of one of the supporting guide plates 301 at the moment, the blade 22 is fixed on the clamping mechanism 20, meanwhile, the blade 22 is also located right above the supporting guide plates 301 (at the moment, the knife face of the blade 22 is perpendicular to the upper end of the supporting guide plate 301), after the blade 22 is installed, the driven shaft 9 is locked through the cooperation of the locking mechanism 19 and the limiting clamping groove 17 so as to prevent the grinding effect from being influenced due to deviation in the grinding process, the two-way motor 12 is started, the two-way motor 12 drives the driving shaft 4 to rotate, the second driving gear 6 on the driving shaft 4 is meshed and connected with the rack on the side wall of the supporting plate 3, the second driving gear 6 moves along the side wall of the supporting plate 3 (the moving direction is shown in figure 3), the driving shaft 4 moves under the action of the first sliding block 8 and the second sliding block 15 and simultaneously and moves to the right And the other end, the driving shaft 4 moves and automatically drives the grinding wheel 7 to move along one face edge of the blade 22 to be ground, when the driving gear II 6 on the driving shaft 4 leaves the supporting guide plate 301 and enters the transition plate 302, the locking mechanism 19 is unlocked from the driven shaft 9, meanwhile, the driving gear I5 starts to be meshed with the driven gear 10, when the driving gear II 6 on the driving shaft 4 moves from one end of the transition plate 302 to the other end of the transition plate 302, at the same time, the driving gear I5 on the driving shaft 4 just starts to be meshed with the driven gear 10 to just separate from the driven gear 10, and just rotates the driven gear 10 by a quarter, so that the driven shaft 9 rotates by 90 degrees clockwise, and further, the blade 22 on the upper end of the driven shaft 9 also rotates by 90 degrees (namely, the blade 22 rotates from the upper part of one supporting guide plate 301 to the other supporting guide plate 301) And the unpolished knife face is opposite to the side where the rack is located, so that the automatic turnover function of the blade 22 is realized, when the driving shaft 4 leaves the transition plate 302, moves to the other supporting guide plate 301 and moves to the end part of the supporting guide plate 301 along the length direction (when the driving shaft 4 leaves the transition plate 302 and enters the other supporting guide plate 301, the locking mechanism 19 locks the driving shaft 9), the grinding wheel 7 grinds the unpolished knife face of the blade 22 while moving, so that the double-face grinding effect is realized, then the bidirectional motor 12 is started to rotate reversely, so that the grinding mechanism returns to the initial position, and in the returning process, the operation is the same as the principle.

Therefore, under the common cooperation of the second driving gear 6 and the rack on the side wall of the support plate 3, the grinding wheel 7 can move from one end of one support guide plate 301 to one end of the other support guide plate 301, and meanwhile, two surfaces of the blade 22 can be ground, so that the grinding efficiency is improved, and meanwhile, the blade 22 can be automatically turned over in the moving process, and the effect of killing two birds with one stone is achieved.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the embodiments and/or modifications of the invention can be made, and equivalents and modifications of some features of the invention can be made without departing from the spirit and scope of the invention.

Claims

1. The utility model provides an automatic convertible sharpedge grinding machine, includes bottom plate (1), fix in bottom plate (1) top and with roof (2) that bottom plate (1) is parallel, the level is fixed backup pad (3) and grinding machanism between bottom plate (1) and roof (2), its characterized in that: the supporting plate (3) is composed of two supporting guide plates (301) and a transition plate (302) used for connecting the two supporting guide plates (301), the two supporting guide plates (301) are in a right angle in the horizontal direction, the transition plate (302) is in an arc-shaped structure, the transition plate (302) and the two supporting guide plates (301) are integrally formed, continuous racks are uniformly distributed on the same sides of the two supporting guide plates (301) and the transition plate (302), a driven shaft (9) is vertically fixed at the upper end of the transition plate (302) through a bearing, a clamping mechanism (20) used for fixing a blade (22) is fixed at the top end of the driven shaft (9), a driven gear (10) is fixed below the clamping mechanism (20) of the driven shaft (9), the transition plate (302) is a quarter of the driven gear (10), a right-angle slide rail I (11) with a T-shaped section is arranged at the bottom end of the top plate (2), the shape of the right-angle sliding rail I (11) is the same as that of the supporting plate (3), a sliding block I (8) is connected in the right-angle sliding rail I (11) in a sliding mode, and the bottom end of the sliding block I (8) is rotatably connected with a polishing mechanism;

grinding machanism includes drive shaft (4) parallel with driven shaft (9), from last to fixing in proper order on drive shaft (4) with emery wheel (7) that blade (22) correspond down, be located same horizontal plane with driven shaft (9) and with drive gear (5) of driven shaft (9) looks adaptation and with backup pad (3) lateral wall meshing connection drive gear two (6), the bottom of drive shaft (4) is fixed with two-way motor (12) through the shaft coupling.

2. The auto-inverting knife sharpener of claim 1, wherein: the driven shaft (9) is located below the driven gear (10) and is fixedly provided with a fixing ring (18) which is rotationally connected with the driven shaft (9), and a locking mechanism (19) is fixed on the fixing ring (18).

3. The auto-inverting knife sharpener of claim 2, wherein: locking mechanism (19) including fix on solid fixed ring (18) lateral wall and opening guide sleeve (1901) downwards, fix permanent magnet piece (1902) on guide sleeve (1901) inside top, fix on permanent magnet piece (1902) and follow the flexible fixed spring (1903) of guide sleeve (1901) length direction and fix electromagnet piece (1904) on fixed spring (1903) bottom, cross cab apron (302) up end and seted up two mutually perpendicular and all with spacing draw-in grooves (17) of electromagnet piece (1904) looks adaptation, and two spacing draw-in grooves (17) correspond respectively and two support deflector (301) are parallel.

4. The auto-inverting knife sharpener of claim 1, wherein: the clamping mechanism (20) comprises a clamping block (201), a fixing groove (202) formed in the center of the upper end of the clamping block (201), two fixing holes I (203) formed in the upper end of the clamping block (201) and symmetrical with the fixing groove (202), a clamping baffle plate (204), a clamping pressure plate (205) fixed to the bottom end of the clamping baffle plate (204), fixing holes II (206) formed in the clamping baffle plate (204) and corresponding to the fixing holes I (203) one by one, and fixing bolts (207) penetrating through the fixing holes II (206) and connected with the fixing holes I (203) in a threaded mode.

5. The auto-inverting sharpener of claim 4, wherein: the inner wall of the fixed groove (202) is provided with a layer of protective pad (21).

6. The auto-inverting knife sharpener of claim 1, wherein: drive gear two (6) upper end is rotated and is connected with connecting block (13), and one side that connecting block (13) are close to backup pad (3) is connected with connecting rod (14), the one end that connecting block (13) were kept away from in connecting rod (14) articulates there is slider two (15), and slider two (15) with set up in backup pad (3) and with right angle slide rail two (16) sliding connection that right angle slide rail (11) the same shape.