CN210706569U

CN210706569U - Compression fittings between material

Info

Publication number: CN210706569U
Application number: CN201921107800.8U
Authority: CN
Inventors: 邓玉坚
Original assignee: Cheung Wo Hing Printing Machinery Co ltd
Current assignee: Cheung Wo Hing Printing Machinery Co ltd
Priority date: 2019-07-15
Filing date: 2019-07-15
Publication date: 2020-06-09
Anticipated expiration: 2029-07-15

Abstract

The utility model belongs to the technical field of compression fittings technique and specifically relates to indicate a compression fittings between material, include frame, supporting mechanism, pressing mechanism and set up in pressing mechanism's guide mechanism, pressing mechanism sets up in the pressfitting seat of frame, sets up in the pressfitting seat and be used for the feeder of transported substance material and install in the pressfitting actuating mechanism of frame including rotating, supporting mechanism is provided with and presses the backup plate of seat cooperation with the pressfitting material, the feeder is located guide mechanism, guide mechanism is used for leading to the material that the feeder was carried, pressfitting actuating mechanism is used for driving the pressfitting seat with the material pressfitting after the direction on the backup plate. The utility model has the advantages of simple structure, convenient operation leads through the removal of guide mechanism to the material, has improved the stability and the position precision that the material removed, rethread pressing seat and backup plate cooperation are in the same place with two adjacent material pressfitting, and the pressfitting between the material is efficient, and the pressfitting is of high quality.

Description

Compression fittings between material

Technical Field

The utility model belongs to the technical field of compression fittings technique and specifically relates to indicate a compression fittings between material.

Background

At present, with the rapid development of economy, people have higher and higher requirements on book production in quality, and more books are produced in types and quantities. In the production and manufacturing process of books, paper materials need to be pressed and bonded, and a plurality of materials are bonded together to form a book; in the prior art, the efficiency of pressing and bonding between paper materials is low, the pressing quality is poor, and a solution needs to be provided urgently.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, an object of the utility model is to provide a compression fittings between material, its simple structure, convenient operation leads through the removal of guide mechanism to the material, has improved the stability and the position accuracy that the material removed, rethread compression seat and backup plate cooperation are in the same place with two adjacent material pressfitting, and the pressfitting between the material is efficient, and the pressfitting is of high quality.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the utility model provides a compression fittings between material, its includes frame, supporting mechanism, pressing mechanism and sets up in pressing mechanism's guide mechanism, pressing mechanism is including rotating the pressing seat that sets up in the frame, set up in the pressing seat and be used for carrying the feeder of material and install the pressfitting actuating mechanism in the frame, supporting mechanism is provided with the backup plate with the cooperation of pressing seat with the pressfitting material, the feeder is located guide mechanism, guide mechanism is used for leading the material that the feeder was carried, pressfitting actuating mechanism is used for driving the pressing seat with the pressfitting of the material after the direction on the backup plate.

Further, the feeder comprises a vacuum conveyor belt and a conveying driving mechanism, wherein the vacuum conveyor belt is rotatably arranged on the pressing seat, the conveying driving mechanism is used for driving the vacuum conveyor belt to rotate, and one side of the vacuum conveyor belt is exposed out of the pressing surface of the pressing seat.

Furthermore, the pressing surface of the pressing seat is provided with a plurality of blowing holes for blowing the materials away from the vacuum conveyor belt.

Furthermore, the material guide mechanism comprises two groups of material guide assemblies arranged in parallel and a distance adjuster used for driving the two groups of material guide assemblies to be close to or far away from each other, and the feeder is positioned between the two groups of material guide assemblies.

Furthermore, the material guiding assembly comprises a material guiding seat in driving connection with the distance adjuster, a plurality of material guiding claws arranged on the material guiding seat and a material guiding elastic sheet arranged at one end, close to the backup plate, of the material guiding claw, the material guiding claws are provided with material guiding inclined planes, the material guiding claws are arranged from top to bottom, the pressing seat is provided with a plurality of guide grooves, and each material guiding claw stretches out of the pressing surface of the pressing seat through one guide groove.

Furthermore, the guide claw is provided with a through hole, one end of the guide elastic sheet is arranged on the outer side of the guide claw, and the other end of the guide elastic sheet protrudes out of the guide inclined plane after passing through the through hole.

Further, the material guiding assembly further comprises a plurality of material guiding rods, and each material guiding rod is located between two adjacent material guiding claws.

Further, the supporting mechanism comprises a supporting seat, a moving seat arranged on the supporting seat in a sliding manner, a moving driver arranged on the supporting seat and used for driving the moving seat to move, and a first air cylinder arranged on the moving seat, wherein a piston rod of the first air cylinder is rotatably connected with the middle part of the backup plate, and the bottom of the backup plate is rotatably connected with the moving seat.

Further, the movable driver comprises a second cylinder, a motor installed on the support seat, a driving gear installed on an output shaft of the motor, a rotating shaft rotatably installed on the support seat, a first driven gear installed on the rotating shaft and engaged with the driving gear, a rack installed on the movable seat, and a second driven gear installed on the rotating shaft and engaged with the rack, wherein a cylinder body of the second cylinder is installed on the movable seat, and a piston rod of the second cylinder is connected with the support seat.

Furthermore, the pressing driving mechanism comprises a rotating rod rotatably arranged on the pressing seat, a cam arranged on the rotating rod, a roller rotatably arranged in the middle of the pressing seat and used for rolling and abutting against the contour of the cam, a rotating driver used for driving the rotating rod to rotate and a tension spring used for driving the pressing seat to reset, wherein one end of the tension spring is connected with the rack, the other end of the tension spring is connected with the pressing seat, and one end, far away from the backup plate, of the pressing seat is rotatably connected with the rack.

The utility model has the advantages that: in this embodiment, the materials are exemplified by two materials, which include cardboard and lining paper. In actual operation, the external device cyclically supplies the jammed paper and the interleaving paper to the feeder, and if the external device supplies the jammed paper to the feeder first and then supplies the interleaving paper to the feeder; the external equipment supplies a paperboard to the feeder, the feeder conveys the paperboard to move along the material guiding mechanism, so that the paperboard moves to a set position of a pressing surface of the pressing seat, the material guiding mechanism supports the paperboard, then the pressing driving mechanism drives the pressing seat to rotate close to the backup plate until the pressing surface of the pressing seat presses the paperboard on the material guiding mechanism on the backup plate, the backup plate supports the paperboard, then the pressing driving mechanism drives the pressing seat to reset and rotate, the external equipment supplies a lining paper coated with glue to the feeder, the feeder conveys the lining paper to move along the material guiding mechanism, so that the lining paper moves to the set position of the pressing surface of the pressing seat, the material guiding mechanism supports the lining paper coated with glue, finally the pressing driving mechanism drives the pressing seat to rotate close to the backup plate until the pressing surface of the pressing seat presses the lining paper coated with glue on the material guiding mechanism on the paperboard of the backup plate, pressing and bonding the paperboard and the lining paper together, and enabling the pressed paperboard and the lining paper to lean against the backup plate; according to the actual production requirement, the operations can be repeated, and products (such as books and the like) which are formed by bonding a plurality of paperboard and a plurality of lining paper at intervals can be produced. The utility model has the advantages of simple structure, convenient operation leads through the removal of guide mechanism to the material, has improved the stability and the position precision that the material removed, rethread pressing seat and backup plate cooperation are in the same place with two adjacent material pressfitting, and the pressfitting between the material is efficient, and the pressfitting is of high quality.

Drawings

Fig. 1 is a schematic perspective view of the present invention.

Fig. 2 is a schematic view of the three-dimensional structure of the hidden frame of the present invention.

Fig. 3 is a schematic view of the three-dimensional structure of the pressing mechanism and the material guiding mechanism of the present invention.

Fig. 4 is a schematic perspective view of the pressing mechanism of the present invention.

Fig. 5 is a partially enlarged view of a portion a in fig. 3.

Fig. 6 is a schematic perspective view of the supporting mechanism of the present invention.

Description of reference numerals:

11. a frame; 51. a support mechanism; 511. a backup plate; 512. a supporting seat; 513. a movable seat; 514. a movement driver; 5141. a second cylinder; 5142. a motor; 5143. a driving gear; 5144. a rotating shaft; 5145. a first driven gear; 5146. a rack; 5147. a second driven gear; 515. a first cylinder; 52. a pressing mechanism; 521. a pressing seat; 5211. blowing holes; 5212. a guide groove; 522. a feeder; 5221. a vacuum conveyor belt; 5222. a transfer drive mechanism; 523. a pressing driving mechanism; 5231. a rotating rod; 5232. a cam; 5233. a roller; 5234. a tension spring; 5235. a rotation driver; 53. a material guiding mechanism; 531. a material guiding assembly; 532. a distance adjuster; 533. a material guide seat; 534. a material guiding claw; 535. a material guiding elastic sheet; 536. a material guiding inclined plane; 537. a through hole; 538. a material guiding rod.

Detailed Description

In order to facilitate understanding of those skilled in the art, the present invention will be further described with reference to the following examples and drawings, which are not intended to limit the present invention.

As shown in fig. 1 to 6, the utility model provides a pair of compression fittings between material, it includes frame 11, supporting mechanism 51, pressing mechanism 52 and sets up in pressing mechanism 52's guide mechanism 53, pressing mechanism 52 sets up in pressing seat 521 of frame 11 including rotating, sets up in pressing seat 521 and feeder 522 that is used for carrying the material in pressing seat 521 and installs in frame 11's pressfitting actuating mechanism 523, supporting mechanism 51 is provided with the backup plate 511 with the pressfitting material with the cooperation of pressing seat 521, feeder 522 is located guide mechanism 53, guide mechanism 53 is used for leading the material that feeder 522 carried, pressfitting actuating mechanism 523 is used for driving pressing seat 521 to rotate and will lead the back material pressfitting on backup plate 511. Specifically, the material may be one material or two materials; the utility model is used for two materials that the pressfitting is adjacent.

In this embodiment, the materials are exemplified by two materials, which include cardboard and lining paper. In actual operation, the external device cyclically supplies the jammed paper and the interleaving paper to the feeder 522, and it is assumed that the external device supplies the jammed paper to the feeder 522 and then supplies the interleaving paper to the feeder 522; the external device supplies a paper jam to the feeder 522, the feeder 522 conveys the paper jam to move along the material guiding mechanism 53, so that the paper jam moves to a set position of the pressing surface of the pressing seat 521, at this time, the material guiding mechanism 53 supports the paper jam, then the pressing driving mechanism 523 drives the pressing seat 521 to rotate close to the backup plate 511 until the pressing surface of the pressing seat 521 presses the paper jam on the backup plate 511, the backup plate 511 supports the paper jam, then the pressing driving mechanism 523 drives the pressing seat 521 to rotate again, the external device supplies a lining paper coated with glue to the feeder 522, the feeder 522 conveys the lining paper to move along the material guiding mechanism 53, so that the lining paper moves to a set position of the pressing surface of the pressing seat 521, at this time, the material guiding mechanism 53 supports the lining paper coated with glue, finally the pressing driving mechanism 523 drives the pressing seat 521 to rotate close to the backup plate 511 until the pressing surface of the pressing seat 521 presses the paper jam coated with the lining paper on the glue on the lining paper jam on the material guiding mechanism 53 on the backup plate 511, the paperboard and the lining paper are pressed and bonded together, and the pressed paperboard and the lining paper lean against the backup plate 511; according to the actual production requirement, the operations can be repeated, and products (such as books and the like) which are formed by bonding a plurality of paperboard and a plurality of lining paper at intervals can be produced. The utility model has the advantages of simple structure, convenient operation leads through the removal of guide mechanism 53 to the material, has improved the stability and the position precision that the material removed, and rethread pressing seat 521 cooperates with backup plate 511 in order to be in the same place two adjacent material pressfitting, and the pressfitting between the material is efficient, and the pressfitting is of high quality, is particularly suitable for producing card paper book.

In this embodiment, the feeder 522 includes a vacuum conveyor 5221 rotatably disposed on the press seat 521 and a conveying driving mechanism 5222 for driving the vacuum conveyor 5221 to rotate, and one side of the vacuum conveyor 5221 is exposed to the press surface of the press seat 521; specifically, the conveying driving mechanism 5222 may adopt a structure in which a servo motor drives a timing belt and a timing wheel, and the vacuum conveying belt 5221 is communicated with an external vacuum device.

In actual operation, the external device supplies the material to the vacuum conveyor belt 5221, the vacuum conveyor belt 5221 sucks the surface of the material without glue, and the vacuum conveyor belt 5221 sucks the material to move to a set position of the pressing surface of the pressing seat 521 along the material guiding mechanism 53 under the condition that the conveying driving mechanism 5222 drives the vacuum conveyor belt 5221 to rotate, so that the conveying mode further improves the stability and the position accuracy of the movement of the material.

In this embodiment, the pressing surface of the pressing base 521 is provided with a plurality of blowing holes 5211 for blowing the material off the vacuum conveyor belt 5221, and the blowing holes 5211 are communicated with an external blowing device; when the pressing surface of the pressing base 521 presses the material against the backup plate 511, the vacuum conveyor belt 5221 releases the material, and the material blowing holes 5211 blow the material, so that the material is separated from the vacuum conveyor belt 5221, and the pressing base 521 can press the material against the backup plate 511 conveniently.

Preferably, the number of the vacuum conveyor belts 5221 is two, and two vacuum conveyor belts 5221 are arranged in parallel and at intervals, so that the stability of the vacuum conveyor belts 5221 for sucking materials is improved, the stability of the vacuum conveyor belts 5221 for conveying materials for moving is further improved, and the plurality of blowing holes 5211 are located between the two vacuum conveyor belts 5221, so that the materials are conveniently blown to be separated from the vacuum conveyor belts 5221.

In this embodiment, the material guiding mechanism 53 includes two sets of material guiding assemblies 531 arranged in parallel and a distance adjuster 532 for driving the two sets of material guiding assemblies 531 to approach or separate from each other, and the feeder 522 is located between the two sets of material guiding assemblies 531; specifically, the distance adjuster 532 may adopt a structure in which a servo motor drives a bidirectional lead screw and a nut. Distance between two guide subassemblies 531 can be adjusted to distance adjuster 532, and then be applicable to and lead the material of different specifications, and the practicality is strong, and application scope is wide.

In this embodiment, the material guiding assembly 531 includes a material guiding base 533 connected to the distance adjuster 532 in a driving manner, a plurality of material guiding claws 534 disposed on the material guiding base 533, and a material guiding elastic sheet 535 disposed at an end of the material guiding claw 534 close to the backup plate 511, the material guiding claw 534 is provided with a material guiding inclined surface 536, the plurality of material guiding claws 534 are arranged from top to bottom, the pressing base 521 is provided with a plurality of guiding grooves 5212, the guiding grooves 5212 are horizontally disposed, each material guiding claw 534 protrudes out of the pressing surface of the pressing base 521 through one guiding groove 5212, and the material guiding claw 534 can move along the length direction of the guiding groove 5212. The material guide inclined plane 536 enables the material guide claw 534 to form a material guide structure with a wide top and a narrow bottom, so that the feeder 522 can convey materials to enter the material guide mechanism 53 and move along the material guide mechanism 53, and the material guide elastic sheet 535 has a limiting effect on the materials in the material guide mechanism 53, thereby preventing the materials from being separated from the material guide claw 534 in the moving process.

In actual operation, the feeder 522 conveys materials to move, the materials enter the material guiding mechanism 53 under the guidance of the material guiding inclined surface 536 and move downwards along the material guiding mechanism 53 until the materials move to the set position of the pressing surface of the pressing seat 521, the bottom of the material guiding mechanism 53 supports the bottom of the materials, then the pressing seat 521 presses the materials on the backup plate 511, in the process, along with the rotation of the pressing seat 521, the pressing seat 521 rotates with the materials close to the backup plate 511, the materials move close to the backup plate 511 along the length direction of the material guiding claw 534 and press the material guiding elastic sheet 535, so that the material guiding elastic sheet 535 is elastically deformed until the materials are separated from the material guiding elastic sheet 535 and pressed on the backup plate 511, at the moment, the material guiding elastic sheet 535 is not pressed, and the material guiding elastic sheet 535 returns to the original shape under the action of resilience force, so as to guide and limit the next material.

In this embodiment, the guiding claw 534 is provided with a through hole 537, one end of the guiding elastic piece 535 is installed outside the guiding claw 534, and the other end of the guiding elastic piece 535 protrudes out of the guiding inclined plane 536 through the through hole 537. When the material guide elastic sheet 535 is extruded by the material, the material guide elastic sheet 535 is elastically deformed and retracts into the through hole 537, so that the material is pressed on the backup plate 511; when the material guiding elastic piece 535 is not pressed by the material, the material guiding elastic piece 535 protrudes out of the material guiding inclined plane 536 through the through hole 537.

In this embodiment, the material guiding assembly 531 further includes a plurality of material guiding rods 538, the material guiding rods 538 are parallel to the material guiding claws 534, and each material guiding rod 538 is located between two adjacent material guiding claws 534, so that the accuracy and stability of guiding the material by the material guiding assembly 531 are further improved.

In this embodiment, the supporting mechanism 51 includes a supporting base 512, a moving base 513 slidably disposed on the supporting base 512, a moving driver 514 installed on the supporting base 512 and used for driving the moving base 513 to move, and a first cylinder 515 installed on the moving base 513, wherein a piston rod of the first cylinder 515 is rotatably connected to a middle portion of the backup plate 511, and a bottom portion of the backup plate 511 is rotatably connected to the moving base 513.

The first cylinder 515 can drive the backup plate 511 to rotate, so as to adjust the angle between the backup plate 511 and the movable seat 513, and when the pressing seat 521 presses the material on the backup plate 511, the first cylinder 515 provides a pressing force for the backup plate 511, so that the backup plate 511 and the pressing seat 521 can press the material conveniently, and the quality of material pressing is ensured. Along with the utility model discloses constantly carry out the pressfitting to the material, the material after the pressfitting is more and more on the backup plate 511, removes driver 514 drive and removes seat 513 and take first cylinder 515 and backup plate 511 intermittent type backward movement.

In this embodiment, the moving driver 514 includes a second cylinder 5141, a motor 5142 installed on the supporting seat 512, a driving gear 5143 installed on an output shaft of the motor 5142, a rotating shaft 5144 rotatably installed on the supporting seat 512, a first driven gear 5145 installed on the rotating shaft 5144 and engaged with the driving gear 5143, a rack 5146 installed on the moving seat 513, and a second driven gear 5147 installed on the rotating shaft 5144 and engaged with the rack 5146, wherein a cylinder body of the second cylinder 5141 is installed on the moving seat 513, and a piston rod of the second cylinder 5141 is connected to the supporting seat 512.

When the moving driver 514 needs to drive the moving base 513 to move close to the pressing base 521, the motor 5142 drives the driving gear 5143 to rotate, the rotating driving gear 5143 drives the first driven gear 5145 to rotate, the rotating first driven gear 5145 drives the rotating shaft 5144 to rotate, the rotating shaft 5144 drives the second driven gear 5147 to rotate, the rotating second driven gear 5147 drives the rack 5146 to move, the moving rack 5146 drives the moving base 513 to move, and the moving base 513 drives the backup plate 511 to move forward. When the moving driver 514 needs to drive the moving base 513 to move away from the pressing base 521, the piston rod of the second cylinder 5141 extends, so that the cylinder body of the second cylinder 5141 drives the moving base 513 to move away from the pressing base 521, and the moving base 513 drives the backup plate 511 to move backwards. This structural design stabilizes the movement of the movable stand 513.

In this embodiment, the pressing driving mechanism 523 includes a rotating rod 5231 rotatably disposed on the pressing base 521, a cam 5232 disposed on the rotating rod 5231, a roller 5233 rotatably disposed in the middle of the pressing base 521 and configured to be in rolling contact with the profile of the cam 5232, a rotary driver 5235 configured to drive the rotating rod 5231 to rotate, and a tension spring 5234 configured to drive the pressing base 521 to reset, wherein one end of the tension spring 5234 is connected to the frame 11, the other end of the tension spring 5234 is connected to the pressing base 521, and one end of the pressing base 521, which is away from the backup plate 511, is rotatably connected to the frame 11; specifically, the rotary driver 5235 may adopt a servo motor driving gear set structure, and the tension spring 5234 makes the roller 5233 always interfere with the profile of the cam 5232.

When the pressing driving mechanism 523 needs to drive the pressing seat 521 to rotate, the rotating driver 5235 drives the rotating rod 5231 to rotate, the rotating rod 5231 drives the cam 5232 to rotate, the profile of the rotating cam 5232 is in rolling contact with the roller 5233, so that the roller 5233 drives the pressing seat 521 to transfer, and the pressing seat 521 moves circularly according to an expected movement rule along with the continuous rotation of the cam 5232. The roller 5233 is in rolling contact with the profile of the cam 5232, so that the direct contact between the press seat 521 and the profile of the cam 5232 is avoided, the abrasion of the press seat 521 and the cam 5232 is reduced, and the service lives of the press seat 521 and the cam 5232 are prolonged.

All the technical features in the embodiment can be freely combined according to actual needs.

The above-mentioned embodiment is the utility model discloses the implementation scheme of preferred, in addition, the utility model discloses can also realize by other modes, any obvious replacement is all within the protection scope of the utility model under the prerequisite that does not deviate from this technical scheme design.

Claims

1. The utility model provides a compression fittings between material which characterized in that: the pressing mechanism comprises a pressing seat rotatably arranged on the frame, a feeder arranged on the pressing seat and used for conveying materials, and a pressing driving mechanism arranged on the frame, the supporting mechanism is provided with a backup plate matched with the pressing seat to press the materials, the feeder is located in the guiding mechanism, the guiding mechanism is used for guiding the materials conveyed by the feeder, and the pressing driving mechanism is used for driving the pressing seat to press the guided materials on the backup plate.

2. A device according to claim 1, characterised in that: the feeder comprises a vacuum conveyor belt and a conveying driving mechanism, wherein the vacuum conveyor belt is rotatably arranged on the pressing seat, the conveying driving mechanism is used for driving the vacuum conveyor belt to rotate, and one side of the vacuum conveyor belt is exposed out of the pressing surface of the pressing seat.

3. An inter-material pressing device according to claim 2, wherein: the pressing surface of the pressing seat is provided with a plurality of material blowing holes for blowing materials away from the vacuum conveyor belt.

4. A device according to claim 1, characterised in that: the material guide mechanism comprises two groups of material guide assemblies arranged in parallel and a distance adjuster used for driving the two groups of material guide assemblies to be close to or far away from each other, and the feeder is positioned between the two groups of material guide assemblies.

5. An inter-material pressing device according to claim 4, wherein: the guide assembly comprises a guide seat in driving connection with the distance regulator, a plurality of guide claws arranged on the guide seat and a guide elastic sheet arranged at one end, close to the backup plate, of each guide claw, each guide claw is provided with a guide inclined plane, the guide claws are arranged from top to bottom, the pressing seat is provided with a plurality of guide grooves, and each guide claw stretches out of the pressing surface of the pressing seat through one guide groove.

6. An inter-material pressing device according to claim 5, wherein: the material guide claw is provided with a through hole, one end of the material guide elastic sheet is arranged on the outer side of the material guide claw, and the other end of the material guide elastic sheet extends out of the material guide inclined plane after passing through the through hole.

7. An inter-material pressing device according to claim 5, wherein: the material guiding assembly further comprises a plurality of material guiding rods, and each material guiding rod is located between two adjacent material guiding claws.

8. A device according to claim 1, characterised in that: the supporting mechanism comprises a supporting seat, a moving seat arranged on the supporting seat in a sliding mode, a moving driver arranged on the supporting seat and used for driving the moving seat to move, and a first air cylinder arranged on the moving seat, wherein a piston rod of the first air cylinder is rotatably connected with the middle of the backup plate, and the bottom of the backup plate is rotatably connected with the moving seat.

9. An inter-material press fit device according to claim 8, wherein: the movable driver comprises a second cylinder, a motor arranged on the supporting seat, a driving gear arranged on an output shaft of the motor, a rotating shaft arranged on the supporting seat in a rotating mode, a first driven gear arranged on the rotating shaft and meshed with the driving gear, a rack arranged on the movable seat and a second driven gear arranged on the rotating shaft and meshed with the rack, wherein a cylinder body of the second cylinder is arranged on the movable seat, and a piston rod of the second cylinder is connected with the supporting seat.

10. A device according to claim 1, characterised in that: the pressfitting actuating mechanism sets up in the bull stick of pressfitting seat, installs in the cam of bull stick, rotates and sets up in the middle part of pressfitting seat and be used for rolling the gyro wheel of contradicting with the profile of cam, be used for driving bull stick pivoted rotation driver and be used for driving the extension spring that the pressfitting seat resets in the rotation, the one end and the frame of extension spring are connected, and the other end and the pressfitting seat of extension spring are connected, the one end that the backup plate was kept away from to the pressfitting seat rotates with the frame and is connected.