CN114393307A

CN114393307A - Two-side clamping type welding tool

Info

Publication number: CN114393307A
Application number: CN202210245127.4A
Authority: CN
Inventors: 游迪; 罗盛滔; 王枫宇; 李寿仁; 李鑫阳
Original assignee: Zhejiang Shunde Machinery Co ltd
Current assignee: Zhejiang Shunde Machinery Co ltd
Priority date: 2022-03-14
Filing date: 2022-03-14
Publication date: 2022-04-26
Anticipated expiration: 2042-03-14
Also published as: CN114393307B

Abstract

The utility model provides a both sides centre gripping type welding frock, relates to laser welding centre gripping frock field, including: a base station; the welding device comprises a base station, a driving clamping table, a rotating motor, a welding motor and a welding motor, wherein the driving clamping table is used for clamping the upper part and the lower part of one side of a part to be welded; the driven clamping table is rotatably connected with the base table and is used for clamping the upper part and the lower part of the other side of the part to be welded; the locking mechanism is fixedly arranged on the base station, and the driven clamping table is provided with an insertion part for the locking mechanism to be inserted into; after the locking mechanism is inserted into the insertion part, the driven clamping table interrupts clamping of the part to be welded, and after the locking mechanism leaves the insertion part, the driven clamping table maintains clamping of the part to be welded. This application provides the location to the initial condition of anchor clamps, prevents that the condition that rocks from appearing when not pressing from both sides tight part of waiting to process in anchor clamps.

Description

Two-side clamping type welding tool

Technical Field

The invention relates to the field of laser welding clamping tools, in particular to a two-side clamping type welding tool.

Background

Because the technical problems of manufacturing instruments or molds integrally formed in complex shapes are more, the integral forming is pursued only to raise the manufacturing cost, and the welding mode is still adopted to reduce the cost in the low-batch production; because need connect more than two at least things in welding process, comparatively simple structure can place and weld on ground, but just need to cooperate the centre gripping with the help of anchor clamps to the product that the structure is complicated, in addition, no matter manual welding or with the help of the automatic weld of manipulator, anchor clamps possess the ability of taking the product motion can effectively reduce the welded degree of difficulty.

For example, chinese utility model patent application No. CN202121696058.6 discloses a rotatable welding jig for producing a wind power module, which comprises a fixed plate, a rotary jig structure, and a movable auxiliary rotary structure; the rotary clamp structure comprises a first motor, a synchronous wheel transmission structure, a first rotating shaft, a first bearing seat fixing seat and a first clamping structure; the movable auxiliary rotating structure comprises a moving structure and a jacking structure. The rotary fixture is structurally placed at one end of the wind power module to be welded, the other end of the wind power module is fixed through the movable auxiliary rotary structure, and in the welding process, the rotary fixture structure drives the wind power module to rotate at different angles according to requirements, so that one-time welding is realized, the welding time is greatly shortened, and the welding quality is improved.

But above-mentioned technical scheme does not consider the condition that anchor clamps can't effective location when the centre gripping treats the processing article, because general welded part all is the metalwork, the quality is heavier to need to transport to anchor clamps with the help of the hoist on, in case anchor clamps appear certain rocking will increase the degree of difficulty of unloading, influence efficiency, cause the incident that treats welding part and drop even.

Disclosure of Invention

The utility model provides a both sides centre gripping type welding frock, including: a base station; the welding device comprises a base station, a driving clamping table, a rotating motor, a welding motor and a welding motor, wherein the driving clamping table is used for clamping the upper part and the lower part of one side of a part to be welded; the driven clamping table is rotationally connected with the base table and is used for clamping the part to be welded above and below the other side of the side clamped by the driving clamping table; the locking mechanism is fixedly arranged on the base station, and the driven clamping table is provided with an insertion part for the locking mechanism to be inserted into; after the locking mechanism is inserted into the insertion part, the driven clamping table interrupts clamping of the part to be welded, and after the locking mechanism leaves the insertion part, the driven clamping table maintains clamping of the part to be welded.

Preferably, the insertion part comprises an insertion groove adapted to the locking mechanism and a short-circuit switch located at the bottom end of the insertion groove; when the short circuit switch is disconnected, the driven clamping table maintains a clamping state.

Preferably, the driving clamping table or the driven clamping table is provided with clamping planes for supporting the lower end faces of the parts to be welded, the driving clamping table or the driven clamping table controls clamping or loosening of the parts to be welded through vertical cylinders, and the two vertical cylinders are respectively arranged above the driving clamping table and the driven clamping table; when the locking mechanism is inserted into the inserting groove, the end face of the clamping plane faces upwards and is horizontal.

Preferably, the two vertical cylinders are respectively a first cylinder for controlling the driving clamping table to clamp the part to be welded and a second cylinder for controlling the driven clamping table to clamp the part to be welded, the short-circuit switch is used for controlling the second cylinder, and when the short-circuit switch is switched off, the second cylinder continuously pushes.

Preferably, in the above technical solution, the driven clamping table includes a movable clamping block and a fixed clamping seat, the clamping plane is disposed on the fixed clamping seat and opposite to the lower end of the movable clamping block, and the movable clamping block moves relative to the clamping plane to clamp or loosen the part to be welded by the driven clamping table.

As the optimization of the technical scheme, a safety locking plate is further arranged on the driven clamping table and is fixedly connected with the movable clamping block, and the safety locking plate is detachably connected with the fixed clamping seat through a positioning bolt.

Preferably, the safety lock plate is provided with a waist-shaped hole, the fixed clamping seat is provided with a threaded hole, the positioning bolt penetrates through the waist-shaped hole to be in threaded fit with the threaded hole, the length of the waist-shaped hole is matched with the lifting distance of the movable clamping block, and the nut part of the positioning bolt abuts against the safety lock plate in a fixed state of the fixed clamping seat.

As the optimization of the above technical solution, the base station includes a supporting base plate, a driving clamping table supporting seat, a driven clamping table supporting seat, the driving clamping table supporting seat reaches the driven clamping table supporting seat set on the supporting base plate, a sliding rail is provided on the supporting base plate, the driven clamping table supporting seat passes through the sliding rail and the supporting base plate in sliding connection, and the driven clamping table supporting seat is controlled by a third cylinder to be close to/away from the driving clamping table supporting seat.

Preferably, the lower end surface of the clamping block and the clamping plane are both provided with positioning columns

Preferably, the driving clamping table and the driven clamping table are provided with threading frames.

In summary, the invention has the following advantages:

1. in the embodiment, the initial state of the clamp can be positioned, so that the clamp is prevented from shaking when a part to be machined is not clamped, and the difficulty of feeding and discharging is reduced;

2. furthermore, the clamp provides a supporting plane, so that a part to be machined is more stable when placed on the clamp, and the risk of the part sliding is reduced;

3. still further, this application provides the initial position of locking mechanism to driven centre gripping platform and has carried out the locking and has assisted the location of initiative centre gripping platform then, has set up the short circuit switch in the grafting portion with locking mechanism complex in addition for driven centre gripping platform can relax the part of treating processing only after accomplishing the location, promotes the security of centre gripping.

The benefits of further or other details will be discussed in the examples.

Drawings

FIG. 1 is a schematic diagram of the overall structure of an embodiment of the present application;

FIG. 2 is a front elevation and partial cross-sectional view of an embodiment of the present application;

FIG. 3 is a schematic structural diagram of a driven clamping table according to an embodiment of the present application;

FIG. 4 is a schematic view of a locking mechanism and a mating part according to an embodiment of the present disclosure;

FIG. 5 is a schematic of the circuit for controlling actuation of the second cylinder according to the present application;

FIG. 6 is a schematic view of a part to be welded according to the present application when placed in a welding fixture;

wherein, 1-base station, 2-driving clamping station, 3-driven clamping station, 4-locking mechanism, 5-safety lock plate, 6-threading frame, 11-supporting bottom plate, 12-driving clamping station supporting seat, 13-driven clamping station supporting seat, 111-sliding track, 31-movable clamping block, 32-fixed clamping seat, 34-insertion part, 341-insertion groove, 342-short circuit switch, 100-part to be welded, d-rotating motor, e-rotating shaft bearing, v-1-first rotating shaft, v-2-second rotating shaft, 5-a-waist-shaped hole, C1-first cylinder, C2-second cylinder, C3-third cylinder, R1-driven clamping station working circuit, R2-load resistance, S1-short circuit switch.

Detailed Description

The terms of orientation of up, down, left, right, front, back, top, bottom, and the like as referred to or as may be referred to in this specification are defined with respect to the configuration shown in the drawings, and the terms "inner" and "outer" refer to directions toward and away from the geometric center of a particular component and are relative terms, and thus may be changed accordingly depending on the position and the state of use of the particular component. Therefore, these and other directional terms should not be construed as limiting terms.

The invention is further illustrated by the following examples:

example (b):

referring to fig. 1 and 2, a two-side clamping type welding tool comprises a base station 1, a driving clamping table 2, a driven clamping table 3 and a locking mechanism 4; the active clamping table 2 is used for clamping the upper part and the lower part of one side of a part to be welded, a rotating motor a is arranged in the base table 1 and is in transmission connection with the active clamping table 2 through a first rotating shaft v-1, the rotating motor a is mainly used for controlling the active clamping table 2 to rotate around the central axis of the first rotating shaft v-1, and the rotating motor a can control the active clamping table 2 to rotate for a certain angle in a clockwise or anticlockwise direction and brake, so that the active clamping table 2 is fixed in place after rotating for a certain angle; a rotating shaft bearing e is arranged at the matching position of the base station 1 and the driven clamping station 3, the driven clamping station 3 is in rotating fit with the rotating shaft bearing e on the base station 1 through a second rotating shaft v-2, and the driven clamping station 3 is used for clamping a part to be welded relative to the upper part and the lower part of the other side of the side clamped by the driving clamping station 2; different from the situation that the driving clamping table 2 can be braked at a required position by a rotating motor a to be positioned, the driven clamping table 3 is easy to rotate relative to the driven clamping table 2 under the action of external force, for example, when a part to be welded collides with the driven clamping table 3 during feeding, the driven clamping table 3 can rotate by a certain angle to cause the driven clamping table 3 to swing back and forth, and the unstable driven clamping table 3 influences the feeding efficiency, so that the application designs that the locking mechanism 4 limits the driven clamping table 2 in the feeding stage, the locking mechanism 4 is fixedly arranged on the base table 1, the driven clamping table 3 is provided with an insertion part 34 for the locking mechanism 4 to be inserted into, please combine with the drawing 1 and the drawing 2, under the state that the machine is stopped or the previous part is welded and taken down, the driven clamping table 2 is at the position shown in the drawing 1, at the moment, the locking mechanism 4 is electrically inserted into the insertion part 34 matched with the locking mechanism, the rotation of driven grip slipper 2 is injectd, and the condition of rotation can not appear no matter be the unstable or external force striking driven grip slipper 2 of focus, makes things convenient for subsequent material loading.

In particular, the method comprises the following steps of,referring to fig. 3, the driven clamping table 3 includes a movable clamping block 31 and a fixed clamping seat 32, wherein the movable clamping block 31 is controlled by a second air cylinder C2 to approach or separate from the fixed clamping seat 32, the fixed clamping seat 32 includes a clamping plane 23-a opposite to the movable clamping block 31, the movable clamping block 31 moves relative to the clamping plane 23-a to clamp or loosen the part to be welded by the driven clamping table 3, and a clamping structure adopted by the driving clamping table 2 may be selected as required in the prior art, in this embodiment, the driving clamping table 2 preferably adopts the same clamping structure as the driven clamping table 3 and also includes a clamping plane 23-a, and the driving clamping table 2 is controlled by a first air cylinder C1 to clamp or loosen the part to be welded. First cylinder C1 and second cylinder C2 are the vertical cylinder of vertical setting, and wherein, first cylinder C1 sets up in initiative grip slipper 2 top, and second cylinder C2 sets up in driven grip slipper 3 top and moves clamp splice 31 transmission and be connected. The clamping plane 23-a is mainly used for supporting the parts to be welded placed on the clamping plane, the parts to be welded need to be placed on the driving clamping table 2 and the driven clamping table 3 before the driving clamping table 2 and the driven clamping table 3 are clamped, and the placed area needs to provide support and ensure that the parts placed on the clamping plane do not incline and fall. For the driving clamping table 2 and the driven clamping table 3, in the process from the feeding stage to the clamping state, the clamping plane 23-a of the driving clamping table 2 and the driven clamping table 3 need to be kept horizontal, if the parts to be welded are inclined to a certain degree, the parts are easy to slide when being placed on the driving clamping table 2 and the driven clamping table 3, and safety accidents can happen in a serious situation; for the driven clamping table 3, which is only connected with the base table 1 in a rotating way, namely the rotation can occur by applying force on the surface of the driven clamping table 3 as mentioned above, the position of the clamping plane 23-a can be locked only by the locking mechanism 4 matching with the insertion part 34, therefore, the applicationThe structure is designed in such a way that the clamping plane 23-a of the driven clamping table 3 is upward and horizontal to the ground when the locking mechanism 4 is matched with the inserting part 34. In the whole process from the beginning of clamping to the completion of welding of the driving clamping table 2 and the driven clamping table 3, the driving clamping table 2 drives the driven clamping table 3 to rotate at the same rotating speed and rotating direction, the relative position of the clamping planes 23-a of the driving clamping table 2 and the driven clamping table 3 is kept unchanged, so when the driven clamping table 3 is positioned by the locking mechanism 4 and the inserting part 34, not only the clamping plane 23-a of the driven clamping table 3 is kept horizontal, but also the clamping plane 32-a of the driving clamping table 2 is kept horizontal, the driving clamping table 2 is accurately controlled to be kept horizontal at the same time instead of being kept horizontal by manually observing and adjusting the rotating motor a, in addition, the rotating motor a brakes the driving clamping table 2 when stopping rotating, as long as the power supply of the rotating motor a is cut off at the moment to prevent the rotating motor a from continuously working, the position of the driving clamping table a is kept unchanged when the driving clamping table is controlled to rotate by the rotating motor a next time, in summary, as long as the locking mechanism 4 is successfully engaged with the insertion part 34, it can be determined that the clamping planes 23-a of the driving clamping table 2 and the driven clamping table 3 are kept upward and horizontal. Referring to fig. 6, when the part 100 to be welded is placed on a two-side clamping type welding fixture through a lifting appliance, the clamping planes 23-a of the driving clamping table 2 and the driven clamping table 3 are kept upward and horizontal, and the lower end surface of the part 100 to be welded waits for the next step of downward pressing of the movable clamping block 31 through the supporting stable positions of the two clamping planes 23-a to complete the clamping step.

In a more specific point, the first and second electrodes are,referring to fig. 4 and 5, the insertion part 34 includes an insertion slot 341 adapted to the locking mechanism 4 and a short-circuit switch 342 located at the bottom end of the insertion slot 341; in the present application, the locking mechanism 4 only enters the inside of the inserting portion 34 (i.e. is inserted into the inserting groove 341) during the time period from the loading stage to the clamping state, and the main purpose is to abut against the short-circuit switch 342 inside the inserting groove 341, in the present application, the short-circuit switch 342 and the circuit for controlling the cylinder action of the movable clamping block 31 of the driven clamping table 3 are connected in parallel, and in the specific power circuit diagram of the short-circuit switch 342 and the circuit for controlling the cylinder action are shown in fig. 5, in the diagram, R1 is the working circuit of the driven clamping table 3, and R2 is the working circuit of the driven clamping table 3The load resistor, S1 is the short-circuit switch 342, under the normal power-on condition, S1 is in the off-state, the current provided by the power supply flows through R1 and R2, at this time, the driven clamping table 3 is in the working state, continuously clamps the parts located thereon, when S1 is closed, R1 is short-circuited, the electrons provided by the power supply no longer pass through the line where R1 is located, which is equivalent to that the driven clamping table 3 no longer has the clamping effect in the whole effect, and the existence of R2 mainly prevents the circuit from being burned out. To sum up, with the specific explanation of the whole structure, when the short-circuit switch 342 is pressed, since the resistance in the circuit is nearly zero at this time, electrons pass through the circuit connected with the short-circuit switch 342, the circuit of the second cylinder C2 on the driven clamping table 3 is controlled to be short-circuited, at this time, the second cylinder C2 controlling the movement of the movable clamping block 31 stops working temporarily, the part is no longer controlled by the clamping force of the driven clamping table 3, the clamping state of the part by the driving clamping table 3 is opened, the welded part can be easily taken down, then a new part to be welded is placed in the clamping range of the driving clamping table 2 and the driven clamping table 3, and when the pre-positioning of the new part to be welded by the driving clamping table 2 and the driven clamping table 3 is completed (the new part to be welded is placed on the clamping plane 23-a of the driving clamping table 2 and the driven clamping table 3), the locking mechanism 4 exits from the insertion groove 341, the short-circuit switch 342 is turned off, current flows through the circuit of the second air cylinder C2 of the driven clamping table 3, the second air cylinder C2 is turned on to carry out clamping operation, at this time, the first air cylinder C1 and the second air cylinder C2 respectively clamp the parts to be welded on the two clamping planes 32-a, the parts to be welded are clamped and fixed from the upper and lower ends of the two sides of the parts to be welded, the locking mechanism 4 completely exits from the insertion groove 341 when clamping is completed, and at this time, the driven clamping table 3 can rotate along with the driving clamping table 2.

In conclusion, the whole locking mechanism 4 is matched with the insertion part 34 arranged on the driven clamping table 3, so that the position of the driven clamping table 3 can be stabilized under the condition that the driven clamping table 3 does not clamp any part, the driving clamping table 2 can be assisted to select a proper position to stop and is braked by a motor, the clamping state of the driven clamping table 3 is ensured to be opened under the condition that the whole part is stably arranged on the clamping plane 23-a, the clamping plane 32-a is prevented from being inclined to cause part sliding when loading and unloading are carried out, and safe and efficient welding is ensured.

In addition, in consideration of the problem of applicability, the two-side clamping type welding tool has certain adjusting capacity,utensil for cleaning buttock In a word of body, it is said that,the base 1 includes supporting baseplate 11, initiative grip stage supporting seat 12, driven grip stage supporting seat 13, and initiative grip stage supporting seat 12 and driven grip stage supporting seat 13 set up on supporting baseplate 11, are provided with slip track 111 on the supporting baseplate 11, and driven grip stage supporting seat 13 passes through slip track and supporting baseplate 11 sliding connection, and, driven grip stage supporting seat 13 is close to/keeps away from initiative grip stage supporting seat 12 by the control of third cylinder C3. Based on above-mentioned structure setting, driven centre gripping platform supporting seat 13 is used for adjusting the interval between initiative centre gripping platform 2 and the driven centre gripping platform 3 in the directional removal under the cylinder control to the welding part of different lengths is got to the adaptation clamp.

In a still further aspect of the present invention,the part processed by welding is generally a metal part, the mass of the part is larger, the part is clamped by the aid of the force exerted by the first air cylinder C1 and the second air cylinder C2, if air leakage occurs in the first air cylinder C1 and the second air cylinder C2 in the working process of the machine, the driving clamping table 2 and the driven clamping table 3 are loosened simultaneously, the tool is rotatable, the part cannot be deflected at any angle under the condition of air leakage, the part can fall off from the welding tool as long as the part cannot obtain effective clamping force or supporting force, the machine is damaged, and even a safety accident is caused, referring to fig. 3, the safety locking plate 5 is arranged on the driven clamping table 3, and after the driving clamping table 2 and the driven clamping table 3 are locked, the position of the driven clamping table 3 is mechanically locked for the second time by the safety locking plate 5, so, even if the circumstances of gas leakage simultaneously appears in first cylinder C1 and second cylinder C2, still be locked owing to the position of driven grip slipper 3, so the circumstances that the part dropped can not appear at least, the lower extreme of safety locking plate 5 with move clamp splice 31 fixed connection, and seted up waist type hole 5-a on the safety locking plate 5, set up threaded hole on the holder 32, safety locking plate 5 passes through positioning bolt detachable the connection with holder 32, specifically, positioning bolt passes and passes the circumstances of leaking gas simultaneouslyThe waist-shaped hole 5-a is in threaded fit with a threaded hole formed in the fixed clamping seat 32, the positioning bolt is continuously tightened by a wrench so that the nut part of the positioning bolt is abutted against the safety locking plate 5, the safety locking plate 5 is tightly attached to the fixed clamping seat 32, the position of the movable clamping block 31 relative to the fixed clamping seat 32 is fixed, the movable clamping block 31 can not move under the action of external force, therefore, the clamping safety is ensured, when the movable clamping block 31 needs to move, only the positioning bolt needs to be loosened by a spanner, the positioning bolt does not need to be completely rotated out of a threaded hole, only the nut of the positioning bolt does not cling to the safety locking plate 5 any more, during the process that the movable clamping block 31 moves up and down, the stud part of the positioning bolt moves relatively in the kidney-shaped hole 5-a without interfering with the movement of the movable clamping block 31, and based on the relative movement, when the safety locking piece 5 is designed, the length of the waist-shaped hole 5-a is the same as the lifting distance of the movable clamping block 31.

The upper end surface and the lower end surface of two sides of a part to be welded are provided with matching grooves, the clamping plane 23-a and the lower end surface of the movable clamping block 31 are both provided with positioning columns 23-b, the positioning columns 23-b are truncated cone-shaped, the surface fixed with the clamping plane 23-a or the lower end surface of the movable clamping block 31 is a bottom surface, the area of the bottom surface is larger than that of the top surface, the inner contour of the matching groove is the same as that of the positioning columns 23-b, the design is mainly to facilitate the positioning of the welding parts when the welding parts are placed on the driving clamping table 2 and the driven clamping table 3, of course, in order to improve the applicability of the two-side clamping type welding tool, the positioning column 23-b is detachably connected with the driving clamping table 2 and the driven clamping table 3, because not every workpiece to be welded is provided with a mating groove, some parts may not be able to be provided with a mating groove due to shape or function limitations.

Because this application is the frock that can rotate, all install threading frame 6 on initiative grip-pad 2 and the driven grip-pad 3 and guide the trachea of cylinder (the trachea of cylinder is not drawn in the picture) and walk the line, prevent that the trachea from twining.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. The utility model provides a both sides centre gripping type welding frock which characterized in that, including:

a base (1);

the welding fixture comprises a base station (1), an active clamping table (2) and a welding fixture, wherein the active clamping table (2) is used for clamping the upper part and the lower part of one side of a part to be welded, a rotating motor (a) is arranged on the base station (1), the active clamping table (2) is in transmission connection with the rotating motor (a), and the rotating motor (a) controls the active clamping table (2) to rotate;

the driven clamping table (3) is rotationally connected with the base table (1) and is used for clamping the part to be welded relative to the upper part and the lower part of the other side of the side clamped by the driving clamping table (2);

the locking mechanism (4) is fixedly arranged on the base station (1), and the driven clamping table (3) is provided with an inserting part (34) into which the locking mechanism (4) is inserted; after the locking mechanism (4) is inserted into the insertion part (34), the driven clamping table (3) interrupts clamping of the part to be welded, and after the locking mechanism (4) leaves the insertion part (34), the driven clamping table (3) maintains clamping of the part to be welded.

2. The both sides centre gripping type welding frock of claim 1, its characterized in that: the plug-in part (34) comprises an insertion groove (341) matched with the locking mechanism (4) and a short-circuit switch (342) positioned at the bottom end of the insertion groove (341); when the short-circuit switch (342) is switched off, the driven clamping table (3) maintains a clamping state.

3. The both sides centre gripping type welding frock of claim 2, its characterized in that: the driving clamping table (2) or the driven clamping table (3) is provided with clamping planes (23-a) for supporting the lower end faces of parts to be welded, the driving clamping table (2) or the driven clamping table (3) controls clamping or loosening of the parts to be welded through two vertical cylinders, and the two vertical cylinders are respectively arranged above the driving clamping table (2) and the driven clamping table (3); when the locking mechanism (4) is inserted into the insertion groove (341), the end surface of the clamping plane (23-a) faces upwards and is horizontal.

4. The both sides centre gripping type welding frock of claim 3, its characterized in that: two vertical cylinder is respectively for control initiative grip slipper (2) are treated welding part and are carried out first cylinder (C1) of clamping action and be used for control driven grip slipper (3) are treated welding part and are carried out second cylinder (C2) of clamping action, short circuit switch (342) are used for control second cylinder (C2), work as when short circuit switch (342) break off, second cylinder (C2) continuously promote.

5. The both sides centre gripping type welding frock of claim 4, its characterized in that: the driven clamping table (3) comprises a movable clamping block (31) and a fixed clamping seat (32), the clamping plane (23-a) is arranged on the fixed clamping seat (32) and is opposite to the lower end of the movable clamping block (31), and the movable clamping block (31) moves relative to the clamping plane (23-a) so as to clamp or loosen the part to be welded by the driven clamping table (3).

6. The both sides centre gripping type welding frock of claim 5, characterized in that: still be provided with safe locking plate (5) on driven centre gripping platform (3), safe locking plate (5) with move clamp splice (31) fixed connection, just, safe locking plate (5) pass through positioning bolt with decide the detachable connection of holder (32).

7. The both sides centre gripping type welding frock of claim 6, its characterized in that: waist type hole (5-a) has been seted up on safety lock piece (5), set up threaded hole on holder (32), positioning bolt passes waist type hole (5-a) with screw hole screw-thread fit, the length of waist type hole (5-a) with the lift distance looks adaptation that moves clamp splice (31), safety lock piece (5) with under holder (32) fixed state, positioning bolt's nut part supports and leans on safety lock piece (5).

8. The both sides centre gripping type welding frock of claim 1, its characterized in that: base station (1) is including supporting baseplate (11), initiative grip block supporting seat (12), driven grip block supporting seat (13), initiative grip block supporting seat (12) reaches driven grip block supporting seat (13) set up in on supporting baseplate (11), be provided with slip track (111) on supporting baseplate (11), driven grip block supporting seat (13) are passed through slip track (111) with supporting baseplate (11) sliding connection, just, driven grip block supporting seat (13) are close to/keep away from by third cylinder (C3) control initiative grip block supporting seat (12).

9. The both sides centre gripping type welding frock of claim 3, its characterized in that: and positioning columns (23-b) are arranged on the lower end surface of the clamping block (231) and the clamping plane (23-a).

10. The both sides centre gripping type welding frock of claim 1, its characterized in that: the driving clamping table (2) and the driven clamping table (3) are provided with threading frames (6).