CN110387456B

CN110387456B - New energy automobile torsion bar spring suspension surface laser heat treatment device

Info

Publication number: CN110387456B
Application number: CN201910705615.7A
Authority: CN
Inventors: 刘华
Original assignee: Suida Taizhou New Energy Co ltd
Current assignee: Suida Taizhou New Energy Co ltd
Priority date: 2019-08-01
Filing date: 2019-08-01
Publication date: 2021-04-16
Anticipated expiration: 2039-08-01
Also published as: CN110387456A

Abstract

The invention discloses a laser heat treatment device for the surface of a torsion bar spring suspension of a new energy automobile, which comprises a reaction frame, wherein a reaction cavity is formed in the reaction frame, the reaction cavity is upwards communicated with the outside, a clamping cavity and a constant pressure cavity which are communicated with the reaction cavity are respectively formed in the front end and the rear end of the reaction cavity, two positioning plates are welded on the top of the reaction frame, and one ends, close to each other, of the two positioning plates are respectively provided with a clamping groove. Has the advantages that: the invention is provided with the movable baffle and the driven gear, which perfectly realizes the centering clamping of the torsion bar, and when the torsion bar moves to the reaction cavity, the micro motor can be started to drive the driving gear to rotate, the driving gear can drive the driven gear meshed with the driving gear to rotate in the rotating process, the driven gear rotates to drive the inner circular sleeve to rotate, the inner circular sleeve drives the clamping claw and the torsion bar to rotate, and the laser on the laser plate can be ensured to be uniformly irradiated on the torsion bar.

Description

New energy automobile torsion bar spring suspension surface laser heat treatment device

Technical Field

The invention relates to the technical field of suspension machining, in particular to a laser heat treatment device for the surface of a torsion bar spring suspension of a new energy automobile.

Background

The torsion bar spring suspension is a rod spring which generates spring action by utilizing torsional deformation of rod (or bar or strip) material, and is characterized by that its unit volume can be used for producing spring action, and its unit volume can be used for storing large energy, its structure form is simple, and its weight is light, so that it can be used as suspension spring and stabilizing device of vehicle, and can be used as valve spring of high-speed rotating machine. The cross section of the torsion bar spring suspension frame material generally comprises three types of round bar materials, hollow bar materials and rectangular cross section bar materials, and the most common is the torsion bar spring suspension frame made of the round bar materials; the existing torsion bar bending, uneven hardness, fatigue resistance weakening, large relaxation deformation and the like easily caused, and the application solves the problems.

Disclosure of Invention

The invention aims to solve the problems that a torsion bar is easy to bend, uneven in hardness, weak in fatigue resistance, large in relaxation deformation amount and the like in the prior art, and provides a laser heat treatment device for the surface of a torsion bar spring suspension of a new energy automobile.

In order to achieve the purpose, the invention adopts the following technical scheme: a laser heat treatment device for the surface of a torsion bar spring suspension of a new energy automobile comprises a reaction frame, wherein a reaction cavity is formed in the reaction frame, the reaction cavity is upwards communicated with the outside, a clamping cavity and a constant pressure cavity which are communicated with the reaction cavity are respectively formed in the front end and the rear end of the reaction cavity, two positioning plates are welded on the upper top of the reaction frame, a clamping groove is formed in one end, close to each other, of each positioning plate, a laser plate capable of emitting laser is clamped in the two clamping grooves together, the laser plate is located right above the reaction cavity, a light detection plate is fixed at the upper end opening of the reaction cavity and the outside, a plurality of spray heads pointing to the geometric center of the reaction cavity are fixedly connected to the inner wall of the reaction cavity, the spray heads are communicated with an air pipe together, and an air valve for controlling the air pipe to be opened;

the clamping cavity is a cylindrical cavity, a bottom groove parallel to the axis of the clamping cavity is formed in the inner wall of the clamping cavity, a traveling rod is connected to the bottom groove in a rotating mode through a bearing, a movable baffle is connected to the clamping cavity in a sliding mode, a driven gear is fixed to the movable baffle in a concentric mode, the centers of the driven gear and the movable baffle are hollowed out, and the driven gear and the traveling rod are connected with a power device.

In the laser heat treatment device for the surface of the torsion bar spring suspension of the new energy automobile, an adjusting plate is fixed between the reaction cavity and the light detection plate, an adjusting cavity is formed in the adjusting plate, the adjusting cavity is downwards communicated with the reaction cavity, a telescopic film for sealing the adjusting cavity and the reaction cavity is arranged at the communication position of the adjusting cavity and the reaction cavity, the air pipe and the adjusting cavity are jointly communicated with a branch pipe, and the communication position of the branch pipe and the air pipe is positioned on one side, close to the spray nozzle, of the air valve.

In the laser heat treatment device for the surface of the torsion bar spring suspension of the new energy automobile, a fixed baffle is fixedly welded on the inner wall of the constant pressure cavity, a plurality of pores are formed in the fixed baffle, and refractory cotton is filled in each pore.

In foretell new energy automobile torsion bar spring suspension surface laser heat treatment device, power device includes the slide, the slide is T type structure, the bottom sliding connection of slide is in the kerve, the part that the slide is located the kerve has seted up a screw hole, the screw hole cooperatees with the pole of marcing, the upper end of slide is fixed with a tripod, two extreme point welded fastening that the slide was kept away from to the tripod have a sliding ball, driven gear keeps away from movable baffle's terminal surface and has seted up an annular groove with one heart, two sliding ball sliding connection is in the annular groove, fixedly connected with a micro motor on the slide, micro motor's output fixedly connected with a driving gear, the driving gear meshes with driven gear, the last fixing device who is provided with fixed torsion bar of driven gear.

In the laser heat treatment device for the surface of the torsion bar spring suspension of the new energy automobile, the fixing device comprises an outer circular sleeve and an inner circular sleeve which are concentrically fixed on the driven gear, the diameter of the outer circular sleeve is larger than that of the inner circular sleeve, the outer circular sleeve is rotatably connected with a plurality of circular rods by using bearings, one end of each circular rod, which is positioned outside the outer circular sleeve, is fixedly connected with a handle, one end of each circular rod, which is positioned inside the outer circular sleeve, is fixedly connected with a cylindrical gear, a plurality of cylindrical gears are jointly meshed with a face gear, the face gear is slidably connected with the driven gear, one end, which is far away from the handle, of each circular rod is connected with a screw rod in a threaded manner, and a clamping jaw is.

In the laser heat treatment device for the surface of the torsion bar spring suspension of the new energy automobile, the clamping jaw is formed by welding a columnar slide bar and an arc-shaped plate, the slide bar is welded and fixed with the screw rod, and the slide bar penetrates through the inner circular sleeve and is connected with the inner circular sleeve in a sliding manner.

In the above laser heat treatment device for the surface of the torsion bar spring suspension of the new energy automobile, an annular gear groove is formed in the driven gear, a T-shaped structure is formed in the cross section of the gear groove, a plurality of T-shaped blocks matched with the gear groove are connected in the gear groove in a sliding mode, and each T-shaped block is welded and fixed with the end face gear.

In the laser heat treatment device for the surface of the torsion bar spring suspension of the new energy automobile, the cross section of the sliding rod on the clamping jaw is of a square structure, and each handle is provided with anti-skid grains.

Compared with the prior art, the invention has the advantages that:

1. the movable baffle and the driven gear are arranged, so that the torsion bar is clamped in a centering mode, only the handle needs to be rotated during clamping, the cylindrical gears can synchronously rotate along with the cylindrical gears, the end face gear is driven to rotate around the axis of the driven gear, each cylindrical gear can synchronously rotate to enable the corresponding clamping jaws to approach to the rotating center of the corresponding clamping jaw simultaneously until the torsion bar is fixed to the axis of the driven gear, the torsion bar is fixed, when the torsion bar moves into the reaction cavity, the micro motor can be started to drive the driving gear to rotate, the driving gear can drive the driven gear meshed with the driving gear to rotate in the rotating process, the driven gear rotates to drive the inner circular sleeve to rotate, the torsion bar sleeve drives the clamping jaws and the torsion bar to rotate, and the laser on the laser plate can be uniformly irradiated on the torsion bar.

2. The adjusting plate capable of adjusting the effective irradiation power of the laser plate is arranged, when the air valve is opened, gas in the air pipe can infuse the adjusting cavity to enable the telescopic film to protrude downwards until the air pressure in the adjusting cavity is equal to the air pressure in the air pipe, the larger the opening degree of the air valve is, the larger the air pressure in the air pipe is, the larger the air pressure in the adjusting cavity is, the larger the downward protruding degree of the telescopic film is, and when the telescopic film protrudes downwards, the adjusting plate can form a convex lens to focus parallel light emitted by the laser plate towards the middle. The stronger the laser irradiated on the torsion bar, the more the utilization degree of the laser can be increased, the better the heating effect of the torsion bar is ensured under certain power, the greater the hardness of the torsion bar after heat treatment is completed, the more difficult the torsion, the stronger the fatigue resistance and the smaller the relaxation deformation.

Drawings

FIG. 1 is a cross sectional view of a new energy automobile torsion bar spring suspension surface laser heat treatment device provided by the invention;

FIG. 2 is a side sectional view of a reaction frame part in a new energy automobile torsion bar spring suspension surface laser heat treatment device provided by the invention;

FIG. 3 is a schematic structural view of a movable baffle part in a new energy automobile torsion bar spring suspension surface laser heat treatment device provided by the invention;

fig. 4 is an enlarged schematic view of a portion a of fig. 3.

In the figure: the device comprises a reaction frame 1, a reaction chamber 2, a clamping chamber 3, a constant pressure chamber 4, a positioning plate 5, a laser plate 6, a light detection plate 7, a spray head 8, an air pipe 9, an air valve 10, a fixed baffle 11, a pore 12, a branch pipe 13, an adjusting plate 14, an adjusting chamber 15, a telescopic membrane 16, a movable baffle 17, a driven gear 18, an annular groove 19, a tripod 20, a sliding ball 21, a bottom groove 22, a sliding plate 23, a threaded hole 24, a traveling rod 25, a driving gear 26, an outer circular sleeve 27, a handle 28, a cylindrical gear 29, an end face gear 30, an inner circular sleeve 31, a claw 32 and a screw 33.

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.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are used merely to facilitate the description of the present invention and to simplify the description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and when an element is referred to as being "secured to" another element, it may be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present, and thus the present invention should not be considered limited to such elements.

Examples

Referring to fig. 1-4, a new energy automobile torsion bar spring suspension surface laser heat treatment device comprises a reaction frame 1, wherein a reaction chamber 2 is arranged in the reaction frame 1, the reaction chamber 2 is upwards communicated with the outside, a clamping chamber 3 and a constant pressure chamber 4 which are communicated with the reaction chamber 2 are respectively arranged at the front end and the rear end of the reaction chamber 2, two positioning plates 5 are welded at the upper top of the reaction frame 1, one end, close to each other, of each positioning plate 5 is provided with a clamping groove, a laser plate 6 capable of emitting laser is clamped in the two clamping grooves together, the laser plate 6 is positioned right above the reaction chamber 2, a light detection plate 7 is fixed at the upper end opening of the reaction chamber 2 and the outside, a plurality of spray heads 8 pointing to the geometric center of the reaction chamber 2 are fixedly connected to the inner wall of the reaction chamber 2, the plurality of spray heads 8 are communicated with an air pipe 9 together, and an;

the clamping cavity 3 is a cylindrical cavity, a bottom groove 22 parallel to the axis of the clamping cavity 3 is formed in the inner wall of the clamping cavity 3, a traveling rod 25 is rotatably connected into the bottom groove 22 through a bearing, a movable baffle 17 is slidably connected into the clamping cavity 3, a driven gear 18 is concentrically fixed on the movable baffle 17, centers of the driven gear 18 and the movable baffle 17 are hollowed, and the driven gear 18 and the traveling rod 25 are jointly connected with a power device.

An adjusting plate 14 is fixed between the reaction cavity 2 and the light detecting plate 7, an adjusting cavity 15 is formed in the adjusting plate 14, the adjusting cavity 15 is communicated with the reaction cavity 2 downwards, a telescopic film 16 for sealing the adjusting cavity 15 and the reaction cavity 2 is arranged at the communication position of the adjusting cavity 15 and the reaction cavity 2, the air pipe 9 and the adjusting cavity 15 are communicated together to form a branch pipe 13, and the communication position of the branch pipe 13 and the air pipe 9 is positioned on one side of the air valve 10 close to the spray head 8.

The inner wall of the constant pressure cavity 4 is fixedly welded with a fixed baffle plate 11, a plurality of pores 12 are formed in the fixed baffle plate 11, and refractory cotton is filled in each pore 12. The power device comprises a sliding plate 23, the sliding plate 23 is of a T-shaped structure, the bottom of the sliding plate 23 is slidably connected into a bottom groove 22, a threaded hole 24 is formed in the part, located in the bottom groove 22, of the sliding plate 23, the threaded hole 24 is matched with a traveling rod 25, a tripod 20 is fixed at the upper end of the sliding plate 23, two end points, far away from the sliding plate 23, of the tripod 20 are fixedly welded with a sliding ball 21, an annular groove 19 is concentrically formed in the end face, far away from a movable baffle 17, of a driven gear 18, the two sliding balls 21 are slidably connected into the annular groove 19, a micro motor is fixedly connected onto the sliding plate 23, a driving gear 26 is fixedly connected onto the output end of the micro motor, the driving gear 26 is meshed.

Fixing device is including concentric outer circle cover 27 and the interior circle cover 31 of fixing on driven gear 18, the diameter of outer circle cover 27 is greater than the diameter of interior circle cover 31, use the bearing to rotate on the outer circle cover 27 and be connected with a plurality of round bars, the round bar is located handle 28 of the outer one end fixedly connected with of outer circle cover 27, the round bar is located cylindrical gear 29 of the one end fixedly connected with of outer circle cover 27, a plurality of cylindrical gear mesh jointly has a face gear 30, face gear 30 and driven gear 18 sliding connection, the equal threaded connection of one end that handle 28 was kept away from to every round bar has a screw rod 33, claw 32 of fixedly connected with on the screw rod 33.

The claw 32 is formed by welding a columnar slide rod and an arc-shaped plate, the slide rod is welded and fixed with the screw 33, and the slide rod penetrates through the inner circular sleeve 31 and is connected with the inner circular sleeve in a sliding manner. An annular gear groove and a T-shaped structure of the section of the gear groove are formed in the driven gear 18, a plurality of T-shaped blocks matched with the gear groove are connected in the gear groove in a sliding mode, and each T-shaped block is welded and fixed with the end face gear 30. The cross section of the sliding rod on the clamping jaw is of a square structure, and each handle 28 is provided with anti-skid lines.

When the device is used, a torsion bar to be subjected to heat treatment penetrates through the movable baffle 17, the torsion bar is fixed by using the fixing device, the handle 28 is twisted by using a hand in the process, the handle 28 drives the screw 33 fixed with the handle to rotate, and the slide bar on the jaw 32 cannot rotate along with the screw 33 and only can slide relative to the inner circular sleeve 31, so that the slide bar drives the jaw 32 to move towards the axis of the inner circular sleeve 31 and abut against the torsion bar;

in the rotation process of the handle 28, the cylindrical gears 29 synchronously rotate along with the handle, so as to drive the end face gear 30 to rotate around the axis of the driven gear 18, and each cylindrical gear 29 is meshed with the end face gear 30, so that the cylindrical gears 29 synchronously rotate to enable the corresponding claws 32 to simultaneously approach to the rotating center of the corresponding claws, until the torsion bar is fixed at the axis of the driven gear 18, and the fixation of the torsion bar is completed.

After the torsion bar is fixed, an external driving device is used for driving the advancing rod 25 to rotate, and the advancing rod 25 is matched with the threaded hole 24, and the sliding plate 23 cannot rotate in the bottom groove 22, so that the sliding plate 23 can slide towards the reaction cavity 2 along the bottom groove 22 in the rotating process of the advancing rod 25, and the torsion bar can move towards the lower part of the laser plate 6;

when the torsion bar moves to the reaction chamber, the micro motor can be started to drive the driving gear 26 to rotate, the driving gear 26 can drive the driven gear 18 engaged with the driving gear to rotate in the rotating process, the driven gear 18 rotates to drive the inner circular sleeve 31 to rotate, the inner circular sleeve 31 drives the clamping jaws 32 and the torsion bar to rotate, and the laser on the laser plate 6 can be uniformly irradiated on the torsion bar.

The laser emitted downwards by the laser plate 6 can directly irradiate the torsion bar, and in the laser heat treatment process, the gas valve 10 can be opened to blow inert gas into the reaction chamber through the gas pipe 9 from the outside, and the inert gas can prevent residual oxygen in the reaction chamber 2 from oxidizing the torsion bar in a high-temperature state.

The adjusting plate 14 communicated with the air pipe 9 is arranged, the laser plate 6 can irradiate uniform laser downwards, more laser can be directly irradiated on the torsion bar, the effective irradiation power of the laser plate 6 is increased, the telescopic membrane 16 has certain elasticity, when the air valve 10 is opened, the air in the air pipe 9 can be infused into the adjusting cavity 15, the air pressure in the adjusting cavity 15 is increased to extrude the telescopic membrane 16 to be protruded downwards until the air pressure in the adjusting cavity 15 is equal to the air pressure in the air pipe 9, and it is worth explaining that the larger the opening degree of the air valve 10 is, the larger the air pressure in the air pipe 9 is, the larger the air pressure in the adjusting cavity 15 is, and the larger the downward protruding degree of the telescopic membrane 16 is;

when the telescopic film 16 is protruded downwards, the adjusting plate 14 forms a convex lens to focus the parallel light emitted from the laser plate 6 towards the middle, and in the present invention, the more the telescopic film 16 is protruded downwards, the shorter the focal length of the convex lens formed by the adjusting plate 14 is, and the larger the focusing degree of the laser light emitted from the laser plate 6 is. The stronger the laser irradiated on the torsion bar, the more the utilization degree of the laser can be increased, the better the heating effect of the torsion bar is ensured under certain power, the greater the hardness of the torsion bar after heat treatment is completed, the more difficult the torsion, the stronger the fatigue resistance and the smaller the relaxation deformation.

Although terms such as the reaction frame 1, the reaction chamber 2, the clamping chamber 3, the constant pressure chamber 4, the positioning plate 5, the laser plate 6, the light detection plate 7, the spray head 8, the gas pipe 9, the gas valve 10, the fixed baffle 11, the fine hole 12, the branch pipe 13, the adjusting plate 14, the adjusting chamber 15, the telescopic membrane 16, the movable baffle 17, the driven gear 18, the annular groove 19, the tripod 20, the sliding ball 21, the bottom groove 22, the sliding plate 23, the threaded hole 24, the traveling rod 25, the driving gear 26, the outer circular sleeve 27, the handle 28, the cylindrical gear 29, the face gear 30, the inner circular sleeve 31, the claw 32, and the screw 33 are used more frequently, the possibility of using other terms is not excluded. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed as being without limitation to any additional limitations that may be imposed by the spirit of the present invention.

Claims

1. A new energy automobile torsion bar spring suspension surface laser heat treatment device comprises a reaction frame (1) and is characterized in that a reaction cavity (2) is formed in the reaction frame (1), the reaction cavity (2) is upwards communicated with the outside, a clamping cavity (3) and a constant pressure cavity (4) which are communicated with the reaction cavity (2) are respectively formed in the front end and the rear end of the reaction cavity (2), two positioning plates (5) are welded on the upper top of the reaction frame (1), one ends, close to each other, of the two positioning plates (5) are respectively provided with a clamping groove, a laser plate (6) capable of emitting laser is clamped in the two clamping grooves together, the laser plate (6) is located right above the reaction cavity (2), a light detection plate (7) is fixed at the upper end connection opening of the reaction cavity (2) and the outside, and a plurality of spray nozzles (8) pointing to the geometric center of the reaction cavity (2) are fixedly connected to the inner wall of the reaction cavity (2), the plurality of nozzles (8) are communicated with an air pipe (9) together, and an air valve (10) for controlling the opening and closing of the air pipe (9) is arranged on the air pipe;

the clamping cavity (3) is a cylindrical cavity, a bottom groove (22) parallel to the axis of the clamping cavity (3) is formed in the inner wall of the clamping cavity (3), a traveling rod (25) is rotatably connected in the bottom groove (22) through a bearing, a movable baffle (17) is connected in the clamping cavity (3) in a sliding mode, a driven gear (18) is concentrically fixed on the movable baffle (17), the centers of the driven gear (18) and the movable baffle (17) are hollowed, and the driven gear (18) and the traveling rod (25) are jointly connected with a power device;

the power device comprises a sliding plate (23), the sliding plate (23) is of a T-shaped structure, the bottom of the sliding plate (23) is slidably connected into a bottom groove (22), a threaded hole (24) is formed in the part, located in the bottom groove (22), of the sliding plate (23), the threaded hole (24) is matched with a traveling rod (25), a tripod (20) is fixed to the upper end of the sliding plate (23), two end points, far away from the sliding plate (23), of the tripod (20) are fixedly welded with a sliding ball (21), an annular groove (19) is concentrically formed in the end face, far away from a movable baffle (17), of a driven gear (18), the two sliding balls (21) are slidably connected into the annular groove (19), a micro motor is fixedly connected onto the sliding plate (23), and a driving gear (26) is fixedly connected to the output end of the micro motor, the driving gear (26) is meshed with the driven gear (18), and a fixing device for fixing the torsion bar is arranged on the driven gear (18).

2. The laser heat treatment device for the suspension surface of the torsion bar spring of the new energy automobile according to claim 1, characterized in that an adjusting plate (14) is fixed between the reaction chamber (2) and the light detection plate (7), an adjusting chamber (15) is formed in the adjusting plate (14), the adjusting chamber (15) is communicated with the reaction chamber (2) downwards, a telescopic film (16) for sealing the adjusting chamber (15) is arranged at the communication position of the adjusting chamber (15) and the reaction chamber (2), the air pipe (9) and the adjusting chamber (15) are communicated together to form a branch pipe (13), and the communication position of the branch pipe (13) and the air pipe (9) is located on one side of the air valve (10) close to the spray nozzle (8).

3. The laser heat treatment device for the suspension surface of the torsion bar spring of the new energy automobile according to claim 1, wherein a fixed baffle (11) is fixed to an inner wall of the constant pressure chamber (4) in a welding manner, a plurality of pores (12) are formed in the fixed baffle (11), and refractory cotton is filled in each pore (12).

4. The laser heat treatment device for the suspension surface of the torsion bar spring of the new energy automobile according to claim 1, wherein the fixing device comprises an outer circular sleeve (27) and an inner circular sleeve (31) which are concentrically fixed on the driven gear (18), the diameter of the outer circular sleeve (27) is larger than that of the inner circular sleeve (31), a plurality of circular rods are rotatably connected to the outer circular sleeve (27) through bearings, a handle (28) is fixedly connected to one end of each circular rod which is positioned outside the outer circular sleeve (27), a cylindrical gear (29) is fixedly connected to one end of each circular rod which is positioned inside the outer circular sleeve (27), a face gear (30) is jointly meshed with the plurality of cylindrical gears, the face gear (30) is slidably connected with the driven gear (18), and a screw rod (33) is threadedly connected to one end of each circular rod which is far away from the handle (28), and a clamping jaw (32) is fixedly connected to the screw rod (33).

5. The laser heat treatment device for the surface of the torsion bar spring suspension of the new energy automobile according to claim 4, wherein the claw (32) is formed by welding a columnar slide bar and an arc-shaped plate, the slide bar is fixedly welded with the screw rod (33), and the slide bar penetrates through the inner circular sleeve (31) and is connected with the inner circular sleeve in a sliding manner.

6. The laser heat treatment device for the suspension surface of the torsion bar spring of the new energy automobile according to claim 4, wherein an annular gear groove is formed in the driven gear (18), the section of the gear groove is of a T-shaped structure, a plurality of T-shaped blocks matched with the gear groove are connected in the gear groove in a sliding mode, and each T-shaped block is welded and fixed with the face gear (30).

7. The laser heat treatment device for the surface of the torsion bar spring suspension of the new energy automobile according to claim 5, wherein the cross section of the sliding bar on the clamping jaws (32) is of a square structure, and each handle (28) is provided with anti-skid lines.