CN219564185U - Plastic welding device - Google Patents

Abstract

The utility model discloses a plastic welding device, which comprises a workbench, wherein the top of the workbench is fixedly connected with a top mounting frame, and a pressing part is arranged below the top mounting frame; the positioning and clamping assembly is fixedly connected with a bottom mounting frame at the top of the workbench, a lower die is fixedly connected with the top of the bottom mounting frame, and positioning and clamping assemblies are arranged on two sides of the bottom mounting frame. According to the utility model, through the structural design of the ejection assembly, the finished product of the oil-gas separator can be ejected by starting the driving cylinder after welding is finished, the oil-gas separator is not required to be taken down manually, the labor intensity of manpower is greatly reduced, the working efficiency is improved, the oil-gas separator is placed at the top of the lower die when welding is carried out through the structural design of the positioning and clamping assembly, and the first movable frame and the second movable frame simultaneously position and clamp the oil-gas separator while the lifting ejector plate moves downwards by starting the driving cylinder.

Description

Plastic welding device

Technical Field

The utility model relates to the technical field of plastic welding equipment, in particular to a plastic welding device.

Background

The engine automobile is provided with an oil-gas separator. The oil-gas separator is used for efficiently separating engine oil in the crankcase blowby gas. When the automobile engine normally works and runs, part of unburned combustible mixed gas and combustion waste gas enter the crankcase, the temperature in the crankcase can be increased by the blowby gas, the evaporation capacity of engine oil of the oil pan is increased, and the cover plate of the oil-gas separator and the separator body are required to be welded during production. The welding mode is that special welding lines placed at the joint of the plastics are melted by ultrasonic waves or electromagnetic waves, so that the welding joint of the plastics is realized.

As disclosed in chinese patent (CN 217752813U), an automatic frequency tracking welding device for plastic part processing is disclosed, one side of the automatic frequency tracking welding device is rotatably connected with an adjusting handle, a chute is formed on the upper surface of the automatic frequency tracking welding device, one end of the bidirectional screw rod penetrates through one side of the automatic frequency tracking welding device, the clamping mechanism comprises two clamping blocks, the two clamping blocks are slidably connected to the upper surface of the automatic frequency tracking welding device, the sliding block is in threaded connection with the outer surface of the bidirectional screw rod, and the inner wall of the sliding block is attached to the inner wall of the sliding block. This an automatic frequency-chasing welding set for plastic part processing can be with base centre gripping, also can carry out the centre gripping to the work piece simultaneously to the fixed work piece of being convenient for prevents that the unexpected skew of work piece from leading to processing failure.

However, when the present inventors embodied this device, the following drawbacks were found to exist: the welding device needs manual operation when clamping the workpiece, and clamping work needs to be carried out on two sides respectively, so that the welding device is not convenient to use and not efficient enough in working efficiency.

Based on the above, a plastic welding device is provided, and a new solution is provided for solving the technical problems.

Disclosure of Invention

Based on this, it is necessary to provide a plastic welding device, through the structural design of ejecting subassembly, make after the welding accomplish can be ejecting with the oil and gas separator finished product through the start drive cylinder, need not the manual work and take off the oil and gas separator, artificial intensity of labour has greatly reduced, work efficiency has been improved, structural design through location clamping assembly makes when welding, place the oil and gas separator at the top of lower mould, start drive cylinder, can make lift ejector plate downwardly moving while first movable frame and second movable frame simultaneously carry out location clamp to the oil and gas separator, after the welding work is accomplished, start drive cylinder and remove the oil and gas separator ejecting while first movable frame and second movable frame are kept away from each other towards the direction of keeping away from each other, thereby automatic unclamping is to the clamp of oil and gas separator, easy operation is swift, greatly increased convenience when using, through the setting of flexible clamping lever, can slide relative first movable frame or second movable frame according to the appearance of part, thereby adapt to the part of different appearances, and can repeat practicality, greatly increased the practicality of this welding device.

In order to solve the technical problems, the utility model adopts the following technical scheme:

a plastic welding device is applied to welding of plastic products.

The plastic welding device specifically comprises: the workbench is characterized in that the top of the workbench is fixedly connected with a top mounting frame, and a pressing part is arranged below the top mounting frame;

the positioning and clamping assembly is fixedly connected with a bottom mounting frame at the top of the workbench, a lower die is fixedly connected with the top of the bottom mounting frame, and positioning and clamping assemblies are arranged on two sides of the bottom mounting frame;

and the ejection assembly is arranged on the inner side of the bottom mounting frame and positioned below the lower die.

As a preferred implementation mode of the plastic welding device provided by the utility model, the ejection assembly comprises a driving cylinder and a lifting ejector plate, the bottom of the inner side of the bottom mounting frame is fixedly connected with the driving cylinder, the output end of the driving cylinder is fixedly connected with the lifting ejector plate, four end corners of the top of the lifting ejector plate are respectively fixedly connected with a first ejector rod, a second ejector rod, a third ejector rod and a fourth ejector rod, the tops of the first ejector rod, the second ejector rod, the third ejector rod and the fourth ejector rod penetrate through the bottom mounting frame and the lower die and are in sliding connection with the bottom mounting frame and the lower die, the tops of the first ejector rod, the second ejector rod, the third ejector rod and the fourth ejector rod are all in the same inclined plane with the top of the lower die, and the top of the inner side of the bottom mounting frame is provided with an ejector groove which can be matched with the lifting ejector plate.

As a preferred implementation mode of the plastic welding device provided by the utility model, the positioning and clamping assembly comprises the connecting plates and the driving racks, the connecting plates are fixedly connected to the two sides of the bottom of the lifting ejector plate, the driving racks are fixedly connected to the tops of the two connecting plates, which are far away from each other, respectively, the driving racks are rotatably connected to the two sides of the bottom mounting frame through the rotating shafts, and the driving racks are meshed with the driving gears.

As a preferred implementation mode of the plastic welding device provided by the utility model, the positioning and clamping assembly further comprises a transmission rack and a displacement mounting box, wherein the transmission rack is connected with the top of one end of the transmission gear, which is far away from the driving rack, in a meshed manner, the outer side of the transmission rack is fixedly connected with the displacement mounting box, the two ends of the top of the displacement mounting box are respectively and rotatably connected with a first connecting rod, the two ends of the top of the bottom mounting box are respectively and rotatably connected with two second connecting rods, a first movable frame is rotatably connected between the tops of the two second connecting rods at one end, a second movable frame is rotatably connected between the tops of the two second connecting rods, which are far away from one end of the first movable frame, and the first movable frame and the second movable frame are respectively and rotatably connected with the two first connecting rods at the same end.

As a preferred implementation mode of the plastic welding device provided by the utility model, one side of the displacement mounting box, which is close to the bottom mounting frame, is provided with the connecting groove, and the rotating shaft is positioned at the inner side of the connecting groove at the same end and is in sliding connection with the connecting groove at the same end.

As a preferred embodiment of the plastic welding device provided by the utility model, a plurality of flexible clamping rods are slidably connected to the inner sides of the first movable frame and the second movable frame and are positioned above the lower die.

As a preferred implementation mode of the plastic welding device provided by the utility model, the pressing part comprises a pressing plate, the pressing plate is in sliding connection with the top mounting frame through a guide post, the top of the top mounting frame is fixedly connected with a hydraulic cylinder, the output end of the hydraulic cylinder penetrates through the top mounting frame and is fixedly connected with the pressing plate, the bottom of the pressing plate is fixedly connected with an upper die, and the inner side of the pressing plate is fixedly connected with an air claw above the upper die.

Compared with the prior art, the utility model has the following beneficial effects:

1. according to the utility model, through the structural design of the ejection assembly, the finished product of the oil-gas separator can be ejected by starting the driving cylinder after welding is finished, the oil-gas separator is not required to be taken down manually, the labor intensity of manpower is greatly reduced, and the working efficiency is improved.

2. According to the utility model, through the structural design of the positioning and clamping assembly, when welding is carried out, the oil-gas separator is placed at the top of the lower die, the driving cylinder is started, so that the lifting ejector plate moves downwards, the first movable frame and the second movable frame simultaneously clamp the oil-gas separator in a positioning way, after the welding work is finished, the driving cylinder is started to eject the oil-gas separator, and the first movable frame and the second movable frame move in the direction away from each other, so that the clamping of the oil-gas separator is automatically released, the operation is simple and quick, and the convenience in use is greatly increased.

3. According to the welding device, the flexible clamping rods are arranged, and the first movable frame or the second movable frame can slide relatively according to the appearance of the part, so that the welding device is suitable for parts with different appearances, can be repeatedly and practically used, and greatly increases the practicability of the welding device.

Drawings

In order to more clearly illustrate the solution of the present utility model, a brief description will be given below of the drawings required for the description of the embodiments, it being obvious that the drawings in the following description are some embodiments of the present utility model, and that other drawings may be obtained from these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a front view of the present utility model;

FIG. 2 is an isometric view of the present utility model;

FIG. 3 is a schematic view of the structure of the bottom mounting bracket, the drive cylinder and the lifting ejector plate of the present utility model;

FIG. 4 is a schematic view of the displacement mounting box and the driving rack, the first movable frame and the second movable frame of the present utility model;

FIG. 5 is a schematic view of the structure of the flexible clamping lever of the present utility model;

FIG. 6 is a schematic view of a second connecting rod according to the present utility model;

fig. 7 is a schematic view of the structure of the transmission gear and the transmission rack of the present utility model.

The labels in the figures are illustrated below:

1. a work table; 2. a top mount; 3. a hydraulic cylinder; 4. a pressing plate; 5. an upper die; 6. a gas claw; 7. a bottom mounting rack; 8. a driving cylinder; 9. lifting the ejector plate; 10. a lower die; 11. a first movable frame; 12. a second movable frame; 13. a flexible clamping rod; 14. a first connecting rod; 15. a second connecting rod; 16. a displacement mounting box; 17. a drive rack; 18. a first ejector rod; 19. a transmission gear; 20. a drive rack; 21. a second ejector rod; 22. a third ejector rod; 23. a fourth ejector rod; 24. a connecting plate; 25. an oil-gas separator.

Detailed Description

In order that those skilled in the art will better understand the present utility model, a technical solution in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present utility model, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present utility model without making any inventive effort, shall fall within the scope of the present utility model.

As mentioned in the background art, the welding device needs manual operation when clamping the workpiece, and the workpiece is clamped on two sides respectively, so that the welding device is inconvenient to use and has low working efficiency.

In order to solve the technical problem, the utility model provides a plastic welding device which is applied to welding of plastic products.

Specifically, referring to fig. 1-7, a plastic welding device specifically includes: the workbench (1), wherein the top of the workbench (1) is fixedly connected with a top mounting frame (2), and a pressing part is arranged below the top mounting frame (2);

the positioning and clamping assembly is fixedly connected with a bottom mounting frame 7 at the top of the workbench 1, a lower die 10 is fixedly connected with the top of the bottom mounting frame 7, and positioning and clamping assemblies are arranged on two sides of the bottom mounting frame 7;

and the ejection assembly is arranged on the inner side of the bottom mounting frame 7 and is positioned below the lower die 10.

According to the plastic welding device provided by the utility model, through the structural design of the ejection assembly, finished products of the oil-gas separator 25 can be ejected through the actuating cylinder 8 after welding is finished, the oil-gas separator 25 is not required to be taken down manually, the labor intensity of manpower is greatly reduced, the working efficiency is improved, through the structural design of the positioning and clamping assembly, the oil-gas separator 25 is placed at the top of the lower die 10 when welding is carried out, the actuating cylinder 8 is actuated, the lifting ejection plate 9 can move downwards while the first movable frame 11 and the second movable frame 12 simultaneously clamp the oil-gas separator 25 in a positioning manner, after the welding work is finished, the actuating cylinder 8 is actuated to eject the oil-gas separator 25 while the first movable frame 11 and the second movable frame 12 move towards the directions far away from each other, so that the clamping of the oil-gas separator 25 is automatically released, the operation is simple and quick, the convenience in use is greatly increased, the parts with different shapes can be adapted to slide relative to the first movable frame 11 or the second movable frame 12 according to the shapes of the parts through the arrangement of the flexible clamping rod 13, and the practicability of the device is greatly increased.

In order to make the person skilled in the art better understand the solution of the present utility model, the technical solution of the embodiment of the present utility model will be clearly and completely described below with reference to the accompanying drawings.

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

It should be noted that, under the condition of no conflict, the embodiments of the present utility model and the features and technical solutions in the embodiments may be combined with each other.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

Example 1

Referring to fig. 1-7, a plastic welding device comprises a workbench 1, wherein a top mounting frame 2 is fixedly connected to the top of the workbench 1, and a pressing part is arranged below the top mounting frame 2; the positioning and clamping assembly is fixedly connected with a bottom mounting frame 7 at the top of the workbench 1, a lower die 10 is fixedly connected with the top of the bottom mounting frame 7, and positioning and clamping assemblies are arranged on two sides of the bottom mounting frame 7; and the ejection assembly is arranged on the inner side of the bottom mounting frame 7 and is positioned below the lower die 10.

Referring to fig. 5, the ejector assembly comprises a driving cylinder 8 and a lifting ejector plate 9, the bottom of the inner side of the bottom mounting frame 7 is fixedly connected with the driving cylinder 8, the output end of the driving cylinder 8 is fixedly connected with the lifting ejector plate 9, four end corners of the top of the lifting ejector plate 9 are respectively fixedly connected with a first ejector rod 18, a second ejector rod 21, a third ejector rod 22 and a fourth ejector rod 23, the tops of the first ejector rod 18, the second ejector rod 21, the third ejector rod 22 and the fourth ejector rod 23 penetrate through the bottom mounting frame 7 and the lower die 10 and are in sliding connection with the bottom mounting frame 7 and the lower die 10, the tops of the first ejector rod 18, the second ejector rod 21, the third ejector rod 22 and the fourth ejector rod 23 are all in the same inclined plane with the top of the lower die 10, ejector grooves which can be matched with the lifting ejector plate 9 are formed in the top of the inner side of the bottom mounting frame 7, and in particular, when the top surfaces of the first ejector rod 18, the second ejector rod 21, the third ejector rod 22 and the fourth ejector rod 23 are in the same plane with the upper surface of the lower die 10, and the first ejector rod 18, the second ejector rod 21, the third ejector rod 22 and the fourth ejector rod 23 are in particular in the same plane, and when the first ejector rod 8, the second ejector rod 21 and the third ejector rod 22 and the fourth ejector rod are in the same plane are simultaneously, and the lifting rod 8 are driven, and the lifting rod 25 are simultaneously, and the lifting ejector rod 23 are well are moved.

According to the plastic welding device, through the structural design of the ejection assembly, after welding is completed, the finished product of the oil-gas separator 25 can be ejected through the start driving cylinder 8, the oil-gas separator 25 is not required to be taken down manually, the labor intensity is greatly reduced, and the working efficiency is improved.

Example 2

The embodiment discloses a specific structure of a positioning and clamping assembly on the basis of embodiment 1, please refer to fig. 5-7, the positioning and clamping assembly comprises a connecting plate 24 and a driving rack 17, both sides of the bottom of a lifting ejector plate 9 are fixedly connected with the connecting plate 24, the tops of the sides, away from each other, of the two connecting plates 24 are fixedly connected with the driving rack 17, both sides of the bottom mounting frame 7 are rotatably connected with a transmission gear 19 through a rotating shaft, the driving rack 17 is in meshed connection with the transmission gear 19, and in particular, the connecting plate 24 can be fixed on both sides of the lifting ejector plate 9 through screws so as to facilitate the installation and the disassembly of the lifting ejector plate 9.

Referring to fig. 5-7, the positioning and clamping assembly further comprises a transmission rack 20 and a displacement mounting box 16, the top of one end of the transmission rack 17 is far away from the transmission gear 19, which is in meshed connection with the transmission rack 20, the outer side of the transmission rack 20 is fixedly connected with the displacement mounting box 16, two ends of the top of the displacement mounting box 16 are all in rotational connection with a first connecting rod 14, two ends of the top of the bottom mounting box 7 are fixedly connected with two second connecting rods 15, a first movable frame 11 is rotationally connected between the tops of the two second connecting rods 15 at one end, a second movable frame 12 is rotationally connected between the tops of the two second connecting rods 15 at one end far away from the first movable frame 11, the first movable frame 11 and the second movable frame 12 are both in rotational connection with the two first connecting rods 14 at the same end, during specific use, the driving cylinder 8 can be driven by the lifting ejector plate 9 to move the two connecting rods 24, and further the driving gear 19 is driven by the driving plate 17 to move the lifting movement, and further the transmission gear 19 is driven by the driving gear 19 to move the lifting movement, and further the lifting movement of the two driving racks 16 is driven by the lifting plate 17 to move the first connecting rods 14, or the first movable frame is driven by the first movable frame is driven to move towards the first movable frame 12, and the manual positioning is easy to work is achieved, and the work is easy to move and the work and the clamping is easy to move towards the opposite.

Referring to fig. 5-7, the displacement mounting boxes 16 are provided with connecting grooves on one side close to the bottom mounting frame 7, the rotating shafts are located on the inner sides of the connecting grooves on the same end and slidably connected with the connecting grooves on the same end, specifically, the displacement mounting boxes 16 perform lifting motion on the outer sides of the rotating shafts, and the rotating shafts and the transmission gears 19 play a role in limiting and guiding the displacement mounting boxes 16 when moving.

According to the plastic welding device, through the structural design of the positioning and clamping assembly, when welding is carried out, the oil-gas separator 25 is placed at the top of the lower die 10, the driving cylinder 8 is started, so that the lifting ejector plate 9 moves downwards, the first movable frame 11 and the second movable frame 12 simultaneously clamp the oil-gas separator 25 in a positioning mode, after the welding work is finished, the driving cylinder 8 is started to move the oil-gas separator 25 in the direction away from each other, and therefore the clamping of the oil-gas separator 25 is automatically loosened, the operation is simple and quick, and convenience in use is greatly improved.

Example 3

This example is further optimized for example 1 and example 2.

Referring to fig. 5-6, the inner sides of the first movable frame 11 and the second movable frame 12 and above the lower mold 10 are slidably connected with a plurality of flexible clamping rods 13, and the plurality of flexible clamping rods 13 can slide relative to the first movable frame 11 or the second movable frame 12 according to the shape of the part, so as to adapt to the parts with different shapes, particularly the special-shaped parts, and the practicality is greatly increased.

Referring to fig. 1-2, the pressing part comprises a pressing plate 4, the pressing plate 4 is slidably connected with the top mounting frame 2 through a guide column, a hydraulic cylinder 3 is fixedly connected with the top of the top mounting frame 2, the output end of the hydraulic cylinder 3 penetrates through the top mounting frame 2 and is fixedly connected with the pressing plate 4, an upper die 5 is fixedly connected with the bottom of the pressing plate 4, and an air claw 6 is fixedly connected with the inner side of the pressing plate 4 and located above the upper die 5.

The application process of the plastic welding device provided by the utility model is as follows:

when welding work is performed, an upper part to be welded is placed in two clamping jaws of the air jaw 6, the air jaw 6 is started, the air jaw 6 clamps the upper part to be welded, then an oil-gas separator 25 is placed on the outer side of the lower die 10, a driving cylinder 8 is started, the driving cylinder 8 drives two connecting plates 24 to move downwards through a lifting ejector plate 9, then two driving racks 17 are driven to move downwards, then the driving racks 17 drive a transmission gear 19 to rotate, then the transmission gear 19 drives a transmission rack 20 to move upwards, then a displacement mounting box 16 is driven to move upwards, then a first connecting rod 14 is driven to move, then a first movable frame 11 and a second movable frame 12 are driven to move towards directions close to each other, positioning and clamping work of a workpiece is completed, and then a hydraulic cylinder 3 drives a pressing plate 4 and an upper die 5 to move downwards integrally, so that welding can be performed;

after the welding is finished, the hydraulic cylinder 3 is started, the hydraulic cylinder 3 drives the pressing plate 4 and the upper die 5 to integrally move upwards, then the driving cylinder 8 is started, the driving cylinder 8 drives the two connecting plates 24 to move upwards through the lifting ejector plate 9, then the two driving racks 17 are driven to move upwards, then the driving racks 17 drive the transmission gear 19 to rotate, then the transmission gear 19 drives the transmission rack 20 to move downwards, then the displacement mounting box 16 is driven to move downwards, then the first connecting rod 14 is driven to move, then the first movable frame 11 and the second movable frame 12 are driven to move towards the direction away from each other, and the machined object is loosened and ejected.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

It is apparent that the above-described embodiments are only some embodiments of the present utility model, but not all embodiments, and the preferred embodiments of the present utility model are shown in the drawings, which do not limit the scope of the patent claims. This utility model may be embodied in many different forms, but rather, embodiments are provided in order to provide a thorough and complete understanding of the present disclosure. Although the utility model has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing description, or equivalents may be substituted for elements thereof. All equivalent structures made by the content of the specification and the drawings of the utility model are directly or indirectly applied to other related technical fields, and are also within the scope of the utility model.

Claims (7)

1. The plastic welding device is applied to welding of plastic products and is characterized by comprising a workbench (1), wherein a top mounting frame (2) is fixedly connected to the top of the workbench (1), and a pressing part is arranged below the top mounting frame (2);

the positioning and clamping assembly is fixedly connected with a bottom mounting frame (7) at the top of the workbench (1), a lower die (10) is fixedly connected with the top of the bottom mounting frame (7), and positioning and clamping assemblies are arranged on two sides of the bottom mounting frame (7);

and the ejection assembly is arranged on the inner side of the bottom mounting frame (7) and is positioned below the lower die (10).

2. A plastic welding device according to claim 1, characterized in that the ejector assembly comprises a driving cylinder (8) and a lifting ejector plate (9), the bottom of the inner side of the bottom mounting frame (7) is fixedly connected with the driving cylinder (8), the output end of the driving cylinder (8) is fixedly connected with the lifting ejector plate (9), four end corners of the top of the lifting ejector plate (9) are fixedly connected with a first ejector rod (18), a second ejector rod (21), a third ejector rod (22) and a fourth ejector rod (23), the tops of the first ejector rod (18), the second ejector rod (21), the third ejector rod (22) and the fourth ejector rod (23) penetrate through the bottom mounting frame (7) and the lower die (10) and are in sliding connection with the bottom mounting frame (7) and the lower die (10), and the tops of the first ejector rod (18), the second ejector rod (21), the third ejector rod (22) and the fourth ejector rod (23) are in a plane which can be matched with the bottom of the lower die (10) and the inner side of the bottom mounting frame (7) is provided with the top of the lifting ejector plate (7).

3. A plastic welding device according to claim 2, characterized in that the positioning and clamping assembly comprises a connecting plate (24) and a driving rack (17), wherein the connecting plates (24) are fixedly connected to two sides of the bottom of the lifting ejector plate (9), the driving racks (17) are fixedly connected to the tops of two sides, away from each other, of the connecting plates (24), the driving rack (19) is rotatably connected to two sides of the bottom mounting frame (7) through a rotating shaft, and the driving rack (17) is meshed with the driving gear (19).

4. A plastic welding device according to claim 3, characterized in that the positioning and clamping assembly further comprises a transmission rack (20) and a displacement mounting box (16), the transmission rack (19) is far away from the top of one end of the driving rack (17) and is connected with the transmission rack (20) in a meshed mode, the outer side of the transmission rack (20) is fixedly connected with the displacement mounting box (16), the two ends of the top of the displacement mounting box (16) are respectively connected with a first connecting rod (14) in a rotating mode, the two ends of the top of the bottom mounting rack (7) are respectively fixedly connected with two second connecting rods (15), a first movable frame (11) is rotatably connected between the tops of the two second connecting rods (15) located at one end, a second movable frame (12) is rotatably connected between the tops of the two second connecting rods (15) located at the same end, and the first movable frame (11) and the second movable frame (12) are respectively connected with the two first connecting rods (14) located at the same end in a rotating mode.

5. A plastic welding device according to claim 4, characterized in that the displacement mounting boxes (16) are provided with connecting grooves on the sides close to the bottom mounting frame (7), and the rotating shafts are located on the inner sides of the connecting grooves on the same end and are slidably connected with the connecting grooves on the same end.

6. A plastic welding device according to claim 4, wherein a plurality of flexible clamping rods (13) are slidably connected to the inner sides of the first movable frame (11) and the second movable frame (12) and above the lower die (10).

7. The plastic welding device according to claim 4, wherein the pressing part comprises a pressing plate (4), the pressing plate (4) is slidably connected with the top mounting frame (2) through a guide column, a hydraulic cylinder (3) is fixedly connected with the top of the top mounting frame (2), an output end of the hydraulic cylinder (3) penetrates through the top mounting frame (2) and is fixedly connected with the pressing plate (4), an upper die (5) is fixedly connected with the bottom of the pressing plate (4), and an air claw (6) is fixedly connected with the inner side of the pressing plate (4) and located above the upper die (5).