CN213108247U

CN213108247U - Welding device for mask ear straps

Info

Publication number: CN213108247U
Application number: CN202021740596.6U
Authority: CN
Inventors: 母德和; 杨华平; 高红茹
Original assignee: Sichuan Lvdong Biotechnology Co ltd
Current assignee: Sichuan Lvdong Biotechnology Co ltd
Priority date: 2020-08-19
Filing date: 2020-08-19
Publication date: 2021-05-04
Anticipated expiration: 2030-08-19

Abstract

The utility model discloses a mask ear band welding device, which relates to the technical field of mask processing and solves the problems of more ear band welding operation flows and low production efficiency in the traditional mask production, and comprises a workbench, wherein the workbench is provided with an ear band positioning welding device, a mask positioning device and an ear band cutting device; a welding plate is arranged between the two ear belt clamping mechanisms on the same side, the welding plates are connected with the linear driving mechanism, and the ear belt positioning plate is connected with the comprehensive driving mechanism; the utility model discloses cut the ear area equidistance, the ear area is integrative with gauze mask location, ear area welding, and the simplified operation flow replaces manual work, increases substantially production efficiency.

Description

Welding device for mask ear straps

Technical Field

The utility model relates to a gauze mask production technical field, concretely relates to gauze mask ear area welding set.

Background

The mask is a sanitary article, is generally worn at the position of the mouth and the nose for filtering air entering the mouth and the nose so as to achieve the effect of blocking harmful gas, smell, spray, virus and other substances, has a certain filtering effect on air entering the lung, and has a very good effect when being worn in the operation in the environment polluted by dust and the like when respiratory infectious diseases are prevalent. The disposable medical mask is widely applied to public protection environments.

The ear strap of gauze mask needs to fix the both sides at the gauze mask main part through heat-pressing welded's mode, in traditional production technology, need carry out isometric cutting to the ear strap earlier, the rethread is artifical carries out the position matching and the location back of gauze mask and ear strap, uses the hot welding mode to weld to accomplish the welding of gauze mask ear strap, this kind of production mode process is numerous, the big degree of automation of manpower demand is low, production efficiency is low, the production that great output demand can't be satisfied to this kind of production mode.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a: in order to solve the problem that the ear strap welding operation flow is many, production efficiency is low in traditional gauze mask production, the utility model provides an effectively simplify work flow, improve production efficiency's gauze mask ear strap fixed-position welding device.

The utility model discloses a realize above-mentioned purpose and specifically adopt following technical scheme: a mask ear strap welding device comprises a workbench, wherein an ear strap positioning welding device, a mask positioning device and an ear strap cutting device are arranged on the workbench, the ear strap positioning welding device comprises a rectangular ear strap positioning plate, two connecting rods are symmetrically arranged on two opposite sides of the ear strap positioning plate, one ends, away from the ear strap positioning plate, of the connecting rods are respectively provided with a winding plate, and four ear strap clamping mechanisms are symmetrically arranged on two opposite sides, which are not connected with a connecting plate, of the ear strap positioning plate; a welding plate is arranged between the two ear belt clamping mechanisms on the same side, a groove which is recessed along the central line of the ear belt positioning plate and can accommodate the welding plate to pass through is arranged on the ear belt positioning plate between the two ear belt clamping mechanisms on the same side, the two welding plates are both connected with a linear driving mechanism which drives the welding plate to reciprocate up and down, and the central point of the ear belt positioning plate is connected with a comprehensive driving mechanism which drives the ear belt positioning plate to reciprocate up and down and rotate around the central point; a fastening table which can be correspondingly attached to the two welding plates is arranged below the ear band positioning plate on the workbench, the mask positioning device is arranged beside the fastening table, and the positioning surface of the mask positioning device and the upper surface of the fastening table are in the same horizontal plane; the ear band cutting device comprises a telescopic cutting execution end, and the cutting execution end faces to a groove on one side of the ear band positioning plate; still be equipped with the tight line roller, the tight line roller remains the coplanar throughout with the ear area locating plate and is close to the side that the ear area was tailor device one side with the ear area locating plate and is located the collinear, and the distance of tight line roller to ear area locating plate is greater than the distance between winder plate to the ear area locating plate.

Preferably, each ear strap clamping mechanism comprises a clamping plate parallel to the side face of the ear strap positioning plate and a linear cylinder driving the clamping plate to be away from or attached to the side face of the ear strap positioning plate, and a cylinder body of the linear cylinder is fixed on the ear strap positioning plate.

Preferably, synthesize actuating mechanism and include casing and the vertical execution lead screw that sets up in the casing, the cover is equipped with screw-nut and spline nut on the execution lead screw, and screw-nut and spline nut all are connected with driving motor, be equipped with on the execution lead screw with the rotatory screw thread of screw-nut adaptation and with the vertical screw thread of spline nut adaptation, be equipped with the support frame on the workstation, the casing is fixed on the support frame, and the lower extreme of execution lead screw stretches out downwards and is connected with the ear area locating plate.

Preferably, the execution screw rod positioned on the upper part of the ear belt positioning plate is sleeved with a bearing sleeve, the bearing sleeve is connected with a fixed rod, and the wire tightening roller is rotatably connected onto the fixed rod.

Preferably, the mask positioning device comprises a mask positioning plate, and limiting plates which can be opened and closed are arranged on the mask positioning plate corresponding to two sides of the mask.

Preferably, the cross section of the plate is l-shaped, one free end of the plate faces the mask positioning plate and is attached to the upper surface of the mask positioning plate, and the other free end of the plate is rotatably connected to the side of the mask positioning plate through a rotary cylinder.

Preferably, the bottom of the mask positioning plate is connected with a rotation driving mechanism for driving the mask positioning plate to rotate around the center of the mask positioning plate.

Preferably, the ear band cutting device comprises a pneumatic scissors and a scissors driving cylinder for driving the pneumatic scissors to do linear reciprocating motion, the execution end of the scissors driving cylinder is connected with the body of the pneumatic scissors, and the pneumatic scissors are driven to extend into or withdraw from a groove on the ear band positioning plate.

Preferably, the side surface of the winding plate which is flush with the side surface of the ear strap positioning plate is provided with an inward concave wire guiding groove with an arc-shaped cross section.

Preferably, one side of the wire winding plate, which is far away from the connecting rod, is arc-shaped.

The utility model has the advantages as follows:

1. the utility model discloses a set up ear area fixed-position welding device, gauze mask positioner and ear area and tailor the device and cut ear area equidistance, ear area and gauze mask location, ear area welding are integrated integrative, and the simplified operation flow replaces manual work, increases substantially production efficiency.

2. The utility model discloses an ear area locating plate is by synthesizing the actuating mechanism drive, can realize linear motion and rotation from top to bottom, and the winder and the ear area clamping mechanism that the collocation side set up directly realize the automation in ear area and get material, press from both sides tight location, and the welding plate that can cooperate when conveniently cutting can reciprocate corresponds ear area and gauze mask downwards in step, welds, and overall structure performance integration nature is strong, avoids the activity duration extravagant, saves the manual work, effectively reduces manufacturing cost.

3. The utility model discloses an ear area clamping mechanism adopts cylinder and clamp plate, utilizes the clamp plate to realize the tight location of clamp of ear area with the side of ear area locating plate, and simple structure easily controls, and the function is stable.

4. The utility model discloses a synthesize actuating mechanism adopts generalized type to carry out the lead screw, and the motor of application difference carries out different drives, can realize sharp reciprocating motion or rotary motion in a flexible way to this drive ear area locating plate is nimble rotatory and upper and lower, and the stable in structure precision is high, and the wide application is in the wrist joint of scara robot, and the part maturity is high, and is with low costs.

5. The utility model discloses the cover is equipped with the bearing housing on carrying out the lead screw, and the bearing housing passes through the dead lever to be connected with the tight line roller rotation, and like this, carry out the lead screw and do not drive tight line roller synchronous revolution when rotatory, tight line roller synchronous motion when carrying out the lead screw up-and-down motion effectively ensures tight line roller rigidity and all the time is in same horizontal plane with ear area locating plate, effectively guarantees ear area feed direction's stability.

6. The utility model realizes the positioning of the mask through the openable limiting plate, facilitates the welding of the ear band, has simple integral structure, saves cost and has stable performance; in addition, the rotary driving mechanism is arranged at the bottom of the mask positioning plate to drive the mask positioning plate to rotate, so that ear bands at two ends of the mask can be conveniently welded, a middle mask reversing process is saved, and the production efficiency is further improved.

7. The utility model discloses a device is tailor to ear area adopts the structure of the pneumatic scissors of cylinder drive, and the part maturity is strong, and the stable performance is convenient for unified control.

8. The utility model discloses set up the metallic channel in the side of winder plate, can be more stable when guaranteeing the wire winding around the winder plate side with the ear area, avoid the ear area slippage.

Drawings

FIG. 1 is a front view of the structure of the present invention;

FIG. 2 is a left side view of FIG. 1;

fig. 3 is a top view of the ear strap positioning plate of fig. 2.

Reference numerals: 1-workbench, 2-scissor driving cylinder, 3-pneumatic scissor, 4-fastening table, 5-clamping plate, 6-linear cylinder, 7-winding plate, 8-shell, 9-execution screw rod, 10-screw nut, 11-driving motor, 12-spline nut, 13-servo electric cylinder, 14-welding plate, 15-support frame, 16-mask positioning plate, 17-limiting plate, 18-rotating shaft, 19-wire guide groove, 20-ear belt wire, 21-connecting rod, 22-bearing sleeve, 23-fixing rod, 24-wire tightening roller, 25-rotating cylinder and 26-ear belt positioning plate.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

In the description of the embodiments of the present invention, it should be noted that the terms "inside", "outside", "up", and the like indicate the directions or positional relationships based on the directions or positional relationships shown in the drawings, or the directions or positional relationships that the products of the present invention are conventionally placed when used, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element to which the term refers must have a specific direction, be constructed and operated in a specific direction, and thus, should not be construed as limiting the present invention.

Example 1

As shown in fig. 1 to 3, the mask ear band welding device provided in this embodiment includes a workbench 1, an ear band positioning and welding device, a mask positioning device and an ear band cutting device are disposed on the workbench 1, the ear band positioning and welding device includes a rectangular ear band positioning plate 26, two connecting rods 21 are symmetrically disposed on two opposite sides of the ear band positioning plate 26, a winding plate 7 is disposed at one end of each connecting rod 21 away from the ear band positioning plate 26, and four ear band clamping mechanisms are symmetrically disposed on two opposite sides of the ear band positioning plate 26, which are not connected to the connecting plates; a welding plate 14 is arranged between the two ear belt clamping mechanisms on the same side, a groove which is recessed along the central line of the ear belt positioning plate 26 and can accommodate the welding plate 14 to pass through is arranged on the ear belt positioning plate 26 between the two ear belt clamping mechanisms on the same side, the two welding plates 14 are both connected with a linear driving mechanism for driving the welding plate 14 to reciprocate up and down, and the central point of the ear belt positioning plate 26 is connected with a comprehensive driving mechanism for driving the ear belt positioning plate 26 to reciprocate up and down and rotate around the central point; a fastening table 4 which can be correspondingly attached to the two welding plates 14 is arranged below the ear band positioning plate 26 on the workbench 1, the mask positioning device is arranged beside the fastening table 4, and the positioning surface of the mask positioning device and the upper surface of the fastening table 4 are in the same horizontal plane; the ear band cutting device comprises a telescopic cutting execution end, and the cutting execution end faces to a groove on one side of the ear band positioning plate 26; still be equipped with tight line roller 24, tight line roller 24 is located gauze mask positioner's top and keeps the coplanar with ear area locating plate 26 throughout to tight line roller 24 is located same straight line with ear area locating plate 26 near the side of ear area cutting device one side, and tight line roller 24 is greater than the distance between 7 to ear area locating plate 26 of winder to ear area locating plate 26's distance, and the ear area directly comes with the coil stock mode, walks around tight line roller 24 and stretches into ear area clamping mechanism. Wherein, the side of the winding plate 7 far away from the connecting rod 21 is arc-shaped, and the side position of the winding plate 7 which is parallel and level with the side of the ear belt positioning plate 26 is provided with a wire groove 19 which is concave inwards and has an arc-shaped cross section, so that the ear belt wire 20 is prevented from slipping off during winding.

In the present embodiment, the ear strap clamping mechanism includes a clamping plate 5 parallel to the side surface of the ear strap positioning plate 26 and a linear cylinder 6 for driving the clamping plate 5 away from or against the side surface of the ear strap positioning plate 26, and the cylinder body of the linear cylinder 6 is fixed on the ear strap positioning plate 26. The linear cylinder 6 is communicated with an external air source.

As a preferred embodiment of the present embodiment, the integrated driving mechanism includes a housing 8 and an actuating screw 9 vertically disposed in the housing 8, the actuating screw 9 is sleeved with a screw nut 10 and a spline nut 12, the screw nut 10 and the spline nut 12 are both connected with a driving motor 11, the actuating screw 9 is provided with a rotating thread adapted to the screw nut 10 and a vertical thread adapted to the spline nut 12, the two driving motors 11 can respectively drive the actuating screw 9 to perform linear reciprocating motion and rotating motion, the structure and the driving principle of the actuating screw rod are the same as those of a scara robot wrist actuating screw rod 9, a screw rod with a proper specification and parts matched with the screw rod are selected according to actual application requirements, a support frame 15 is arranged on the workbench 1, the shell 8 is fixed on the support frame 15, and the lower end of the actuating screw rod 9 extends downwards and is fixedly connected with the upper surface of an ear band positioning plate 26.

Wherein, the linear driving mechanism that drives welding plate 14 up-and-down reciprocating motion adopts servo electric jar 13, and stability is strong and the bearing is big, and welding plate 14 is connected with the power.

In order to guarantee that the wire tightening roller 24 and the ear strap positioning plate 26 are always positioned on the same plane, the bearing sleeve 22 is sleeved on the execution screw rod 9 positioned on the upper portion of the ear strap positioning plate 26, the bearing sleeve 22 is connected with the fixing rod 23, the wire tightening roller 24 is rotatably connected onto the fixing rod 23, therefore, the execution screw rod 9 does not drive the wire tightening roller 24 to rotate synchronously when rotating, the wire tightening roller 24 moves synchronously when the execution screw rod 9 moves up and down, the position of the wire tightening roller 24 is effectively fixed, the wire tightening roller and the ear strap positioning plate 26 are always positioned on the same horizontal plane, and the structure is simple and high.

It should be noted that, in order to facilitate the control of the whole device, a controller may be provided, the controller may be a conventional PLC controller, the integrated driving mechanism, the servo electric cylinder 13, the linear air cylinder 6 and other electrical components may be controlled by the PLC controller in a unified manner, the application of the PLC controller to control the electrical components belongs to the conventional application of the PLC controller, and the control wiring and the like are not uniquely limited, so as to achieve the required functions.

The working principle is as follows: when the utility model is used for ear belt welding, an air source power supply is switched on, a stub bar of the ear belt line 20 is introduced, the stub bar is wound around the wire tightening roller 24 and extends into an ear belt clamping mechanism which is at the same side with the wire tightening roller 24 and is close to the wire tightening roller 24, the clamping is controlled to realize the positioning of the ear belt stub bar, the mask to be welded is fixed on the mask positioning device, the position of the ear belt to be welded on the side edge of the mask is positioned on the fastening table 4, then the comprehensive driving mechanism drives the ear strap positioning plate 26 to rotate, the ear strap is wound on the side surfaces of the winding plate 7 and the ear strap positioning plate 26, then, driving the two ear belt clamping mechanisms positioned on the same side of the wire tightening roller 24 to clamp tightly, positioning the ear belts, driving the ear belt cutting device to be close to and extend into the groove of the ear belt positioning plate 26, cutting the ear belts, winding and positioning the cut ear belts on the wire winding plate 7 and the ear belt positioning plate 26 which are positioned on one side far away from the mask positioning mechanism, and enabling two ends of the cut ear belts to face towards the mask; then, the ear band positioning plate 26 is driven to move downwards to be close to the surface of the mask, so that two stub bars of the ear band are positioned on the mask, the two stub bars are kept still and the welding plate 14 is driven to be attached to the fastening table 4 downwards, the mask ear band welding is completed, the linear air cylinders 6 of the ear band clamping mechanisms of the two stub bars of the ear band which is positioned and cut off are loosened, the positioning of the ear band is loosened, the ear band positioning plate 26 and the welding plate 14 are driven to move upwards to reset, the one-time ear band welding is completed, the direction of the mask is changed and the same position is fixed, the operation is repeated, the two ear band welding of the mask is completed, and the continuous production is carried out in a circulating.

Example 2

As shown in fig. 1 and fig. 3, the present embodiment is further optimized based on embodiment 1, specifically:

the mask positioning device comprises a mask positioning plate 16, the upper surface of the mask positioning plate 16 is flush with a fastening table 4, limiting plates 17 which can be opened and closed are arranged on the mask positioning plate 16 corresponding to two sides of a mask, the cross section of each limiting plate 17 is reversed, one free end of each limiting plate 17 faces the mask positioning plate 16 and is buckled on the upper surface of the mask positioning plate 16, and the other free end of each limiting plate 17 is rotatably connected with the side edge of the mask positioning plate 16 through a rotary cylinder 25. Of course, revolving cylinder 25 switch-on air supply is controlled by the PLC controller, and in order to judge whether to place the gauze mask on the gauze mask locating plate 16, can install inductor (not shown in the figure) on gauze mask locating plate 16, the inductor sets up on gauze mask locating plate 16 bottom plate according to conventional mode, the inductive head up can, revolving cylinder 25 drive limiting plate 17 is rotatory, limiting plate 17 is opened, place the gauze mask on gauze mask locating plate 16, the inductor senses gauze mask and passback PLC controller, PLC controller control revolving cylinder 25 antiport, it can to make limiting plate 17 lock accomplish the gauze mask location on gauze mask locating plate 16.

Example 3

As shown in fig. 2, the present embodiment is further optimized on the basis of the

embodiments

1 and 2, specifically:

the bottom of gauze mask locating plate 16 is connected with the rotatory actuating mechanism of drive gauze mask locating plate 16 around its central rotation through pivot 18, rotatory actuating mechanism preferred use step motor (not shown in the figure) can, once weld the back, start the 16 rotation degrees of step motor drive gauze mask locating plate, can realize gauze mask direction conversion, save secondary positioning time, do not interfere with the fastening platform when in order to ensure gauze mask locating plate 16 is rotatory, the side that gauze mask locating plate 16 is close to the revolving stage and offside side are all the arc that the axial lead top point that uses pivot 18 is the dot.

Example 4

As shown in fig. 1 and fig. 3, the present embodiment is further optimized based on

embodiments

1, 2 and 3, and specifically includes:

the ear band cutting device comprises a pneumatic scissors 3 and a scissors driving cylinder 2 for driving the pneumatic scissors 3 to do linear reciprocating motion, a body of the scissors driving cylinder 2 is fixed on a workbench 1, an execution end of the scissors driving cylinder 2 is connected with the body of the pneumatic scissors 3, the pneumatic scissors 3 is driven to stretch into or withdraw from a groove on an ear band positioning plate 26, the pneumatic scissors 3 is closed after entering the groove, the ear band can be cut, and the ear band can be cut and withdrawn.

Claims

1. The utility model provides a gauze mask ear area welding set, includes workstation (1), its characterized in that: the ear band positioning and welding device comprises a rectangular ear band positioning plate (26), two connecting rods (21) are symmetrically arranged on two opposite sides of the ear band positioning plate (26), one ends, far away from the ear band positioning plate (26), of the connecting rods (21) are respectively provided with a winding plate (7), and four ear band clamping mechanisms are symmetrically arranged on two opposite sides, which are not connected with the connecting plate, of the ear band positioning plate (26); a welding plate (14) is arranged between the two ear belt clamping mechanisms on the same side, a groove which is recessed along the central line of the ear belt positioning plate and can accommodate the welding plate (14) to pass through is arranged on the ear belt positioning plate (26) between the two ear belt clamping mechanisms on the same side, the two welding plates (14) are connected with a linear driving mechanism which drives the welding plate (14) to do up-and-down reciprocating motion, and the central point of the ear belt positioning plate (26) is connected with a comprehensive driving mechanism which drives the ear belt positioning plate (26) to do up-and-down linear reciprocating motion and rotate around the central point; a fastening table (4) which can be correspondingly attached to the two welding plates (14) is arranged below the ear band positioning plate (26) on the workbench (1), the mask positioning device is arranged beside the fastening table (4), and the positioning surface of the mask positioning device and the upper surface of the fastening table (4) are positioned on the same horizontal plane; the ear band cutting device comprises a telescopic cutting execution end, and the cutting execution end faces to a groove on one side of the ear band positioning plate; still be equipped with tight line roller (24), tight line roller (24) and ear area locating plate (26) remain the coplanar throughout and with ear area locating plate (26) be close to the side of ear area cutting device one side and be located the collinear, and tight line roller (24) are greater than the distance between winder (7) to ear area locating plate (26) to the distance of ear area locating plate (26).

2. The mask ear band welding device according to claim 1, wherein: each ear strap clamping mechanism comprises a clamping plate (5) parallel to the side face of the ear strap positioning plate (26) and a linear cylinder (6) for driving the clamping plate (5) to be far away from or attached to the side face of the ear strap positioning plate, and a cylinder body of the linear cylinder (6) is fixed on the ear strap positioning plate (26).

3. The mask ear band welding device according to claim 1, wherein: synthesize actuating mechanism and include casing (8) and vertical execution lead screw (9) of setting in casing (8), the cover is equipped with screw-nut (10) and spline nut (12) on execution lead screw (9), and screw-nut (10) and spline nut (12) all are connected with driving motor (11), are equipped with on execution lead screw (9) with the rotatory screw thread of screw-nut (10) adaptation and with the vertical screw thread of spline nut (12) adaptation, be equipped with support frame (15) on workstation (1), casing (8) are fixed on support frame (15), and the lower extreme of execution lead screw (9) is stretched out downwards and is connected with earlap locating plate (26).

4. The mask ear band welding device according to claim 3, wherein: the execution screw rod (9) positioned on the upper portion of the ear band positioning plate (26) is sleeved with a bearing sleeve (22), the bearing sleeve (22) is connected with a fixing rod (23), and the wire tightening roller (24) is rotatably connected onto the fixing rod (23).

5. The mask ear band welding device according to claim 1, wherein: the mask positioning device comprises a mask positioning plate (16), and limiting plates (17) which can be opened and closed are arranged on the mask positioning plate (16) corresponding to two sides of the mask.

6. The mask ear band welding device according to claim 5, wherein: the cross section of the limiting plate (17) is of an L shape, one free end of the limiting plate (17) faces the mask positioning plate (16) and is attached to the upper surface of the mask positioning plate (16), and the other free end of the limiting plate (17) is rotatably connected with the side edge of the mask positioning plate (16) through a rotary cylinder (25).

7. The mask ear band welding device according to claim 5, wherein: the bottom of the mask positioning plate (16) is connected with a rotary driving mechanism which drives the mask positioning plate (16) to rotate around the center of the mask positioning plate.

8. The mask ear band welding device according to claim 1, wherein: the ear band cutting device comprises pneumatic scissors (3) and a scissors driving cylinder (2) for driving the pneumatic scissors (3) to do linear reciprocating motion, the execution end of the scissors driving cylinder (2) is connected with the pneumatic scissors (3), and the pneumatic scissors (3) is driven to extend into or withdraw from a groove on an ear band positioning plate.

9. The mask ear band welding device according to claim 1, wherein: the side surface of the winding plate (7) which is flush with the side surface of the ear strap positioning plate (26) is provided with a wire guide groove (19) which is concave inwards and has an arc-shaped cross section.

10. The mask ear band welding device according to claim 1 or 9, wherein: one side of the wire winding plate (7) far away from the connecting rod (21) is arc-shaped.