CN108262979B

CN108262979B - PE valve welding machine

Info

Publication number: CN108262979B
Application number: CN201810298076.5A
Authority: CN
Inventors: 于法相; 周运强
Original assignee: Weihai Yinghu Automation Equipment Co ltd
Current assignee: Weihai Yinghu Automation Equipment Co ltd
Priority date: 2018-04-04
Filing date: 2018-04-04
Publication date: 2024-02-06
Anticipated expiration: 2038-04-04
Also published as: CN108262979A

Abstract

The invention discloses a PE valve welding machine, which comprises a workbench, wherein the front side part of the workbench is fixedly connected with a main clamping mechanism used for clamping a valve seat, and the tops of the workbench positioned at the left side and the right side of the main clamping mechanism are connected with auxiliary clamping mechanisms used for clamping an end pipe in a left-right sliding manner; the back side part of the workbench is connected with a welding surface cutting mechanism which can cut the welding surface of the end pipe and the valve seat in a front-back sliding way; secondly, a heating welding mechanism positioned above the welding surface cutting mechanism is also arranged on the rear side part of the workbench; the PE valve welding machine is simple in structure, the valve clamping and assembling mechanism, the welding surface cutting and leveling mechanism and the heating and welding mechanism are compact and reasonable in arrangement structure, high in welding efficiency and high in welding precision.

Description

PE valve welding machine

Technical Field

The invention relates to a PE valve welding machine.

Background

Compared with the traditional metal valve, the PE ball valve has the characteristics of light weight, corrosion resistance, no maintenance, small opening and closing moment, small volume, small occupied area and the like, and is convenient to install and simple to use because of being matched with PE pipe materials, and is more and more common along with the wide use of PE gas pipes in urban gas pipe networks.

As shown in fig. 1, the structure of the current PE valve generally includes a valve seat, a valve ball, a valve rod, two supporting check rings, two end pipes respectively located at two ends of the valve seat, and the like, in addition, the valve ball is installed in an inner cavity of the valve seat, the valve rod is installed at the top of the valve seat and can drive the valve ball to rotate, and the end pipes are generally reducing pipe bodies with a large diameter at one end and a small diameter at the other end, meanwhile, the diameter of the end part of the end pipe close to one side of the valve seat is larger than that of the end pipe far from one side of the valve seat, meanwhile, two opposite inner end surfaces of the two end pipes respectively form welding surfaces for connecting to the valve seat, and two outer end surfaces of the valve seat also respectively form welding surfaces for connecting the two end pipes, in addition, the end pipes are connected to the valve seat through ends with a large diameter, and the end pipes are welded at two ends of the valve seat through a hot melt welding mode, and the supporting check rings are installed between the end pipes and the valve seat in advance before welding; at present, the welding process of the PE valve generally comprises the processes of coaxial fixation of a valve seat and two end pipes, cutting and leveling of a welding surface of the two end pipes connected with the valve seat, heating of the welding surface and pressure maintaining welding of the welding surface.

At present, the welding machine for realizing the welding process generally has the problems of complex structure, low welding precision and low working efficiency.

Disclosure of Invention

The PE valve welding machine is simple in structure, convenient to use, high in automation degree, good in welding efficiency and high in welding precision, and the welding process can be automatically realized.

In order to solve the technical problems, the invention comprises a workbench, wherein a valve clamping and assembling mechanism, a welding surface cutting mechanism and a heating and welding mechanism are arranged on the workbench, and the structure is characterized in that: the valve clamping assembly mechanism comprises a main clamping mechanism fixedly connected to the workbench and used for clamping the valve seat, auxiliary clamping mechanisms used for clamping the same-side end pipes are respectively connected to the tops of the workbench at the left side and the right side of the main clamping mechanism in a left-right sliding manner, and driving mechanisms used for driving the auxiliary clamping mechanisms to slide left and right and enabling the welding surfaces of the two end pipes and the valve seat to coaxially lean against each other are respectively arranged between the workbench and the two auxiliary clamping mechanisms;

the welding surface flattening mechanism comprises flattening cutting plates which are positioned at the rear side of the valve clamping assembly mechanism and are connected to the workbench in a front-back sliding manner, the tops of the left side and the right side of the flattening cutting plates are respectively connected with a flattening cutting frame capable of sliding transversely left and right, the front part of each flattening cutting frame is rotationally connected with a cutter shaft which is transversely arranged, one end of each cutter shaft is provided with a valve seat cutter for cutting a valve seat, the other end of each cutter shaft is provided with an end pipe cutter for cutting an end pipe, each flattening cutting frame is also provided with a cutter motor for driving the cutter shaft to rotate, the workbench is provided with a longitudinal flattening cutting driving mechanism for driving the flattening cutting plates to slide forwards and backwards, and when the flattening cutting plates slide forwards for a certain distance, the valve seat cutters and the end pipe cutters can be pushed into gaps of the main clamping mechanism and the auxiliary clamping mechanisms at the same side, and the flattening cutting plates are provided with transverse flattening cutting driving mechanisms for driving the two flattening cutting frames to slide in the same direction or in opposite directions;

The heating welding mechanism comprises a welding bracket arranged on a workbench at the rear side of the valve clamping and assembling mechanism, and the top of the welding bracket is connected with a left welding device and a right welding device which can slide left and right in a sliding manner; the left welding device comprises a welding slide plate which is connected to a welding bracket in a left-right sliding manner, a supporting shaft which is transversely arranged is rotationally connected to the welding slide plate, a welding arm which can swing along the supporting shaft is fixedly connected to the supporting shaft, a first driving device which drives the welding arm to swing in a reciprocating manner is arranged on the welding slide plate, the tail end of the welding arm is fixedly connected with a heating disc which can swing to a welding position at the front lower part when working and a reset position at the rear upper part when not working, the heating disc which swings to the welding position can be coaxially arranged with an end pipe and a valve seat, and the left end surface and the right end surface of the heating disc respectively form a heating surface for heating the welding surface of the end pipe and the welding surface of the valve seat; the right welding device and the left welding device are in the same structure, and are symmetrically arranged along the bilateral symmetry center plane of the main clamping mechanism; and a second driving device for driving the left welding device and the right welding device to slide in the same direction or in opposite directions so as to enable the heating disc to be contacted with or separated from the welding surface of the end pipe at the same side and the welding surface at the corresponding side of the valve seat is also arranged on the welding support.

After the structure is adopted, the valve seat can be clamped in the main clamping mechanism, and the end pipes at two sides can be respectively clamped in the auxiliary clamping mechanisms at the same side; when the welding surfaces of two end pipes and the welding surfaces on two sides of the valve seat are required to be cut and leveled, the two auxiliary clamping mechanisms are slid to a position far away from one side of the main clamping mechanism, then the cutting and leveling plates are pushed to move forwards for a certain distance through the longitudinal cutting and leveling driving mechanism, the valve seat cutters and the end pipe cutters are pushed into gaps between the main clamping mechanism and the auxiliary clamping mechanisms on the same side, meanwhile, the valve seat cutters and the end pipe cutters are ensured to be coaxially arranged with the valve seat, then the transverse cutting and leveling driving mechanism is controlled to push the two cutting and leveling racks to slide in the same direction, the valve seat cutters are contacted with the welding surfaces on two ends of the valve seat, so that the welding surfaces on two ends of the valve seat are cut and leveled, meanwhile, the welding surfaces of the two end pipes are enabled to be attached to the end pipe on the same side, then the cutting and leveling operations are carried out on the welding surfaces of the two end pipes, after the cutting and leveling operations are completed, the two auxiliary clamping mechanisms are controlled to slide reversely, and then the cutting and leveling plates are controlled to move to a reset position; when the welding surfaces of the two end pipes and the welding surfaces on the two sides of the valve seat are required to be heated, the two auxiliary clamping mechanisms are kept to slide to a position far away from one side of the main clamping mechanism, then the heating discs of the left welding device and the right welding device are controlled to swing to the welding position, at the moment, the heating discs swinging to the welding position, the end pipes and the valve seat are coaxially arranged, then the second driving device is controlled to enable the left welding device and the right welding device to slide in the same direction, the heating surfaces of the left heating disc and the right heating disc are respectively pressed against the welding surfaces on the two ends of the valve seat, and meanwhile, the two auxiliary clamping mechanisms are controlled to slide in the same direction, so that the welding surfaces of the two end pipes are respectively pressed against the heating surfaces of the heating discs on the same side, and at the moment, the two heating discs are respectively clamped between the end pipes on the same side and the valve seat, and therefore the welding surfaces of the two end pipes and the two ends of the valve seat can be synchronously heated; after heating for a period of time, controlling the two auxiliary clamping mechanisms to carry out reverse synchronous sliding, simultaneously controlling the left welding device and the right welding device to carry out reverse synchronous sliding, after the heating discs on two sides are separated from the welding surface of the valve seat and the welding surface of the end pipe on the same side respectively, controlling the welding arms on two sides to swing the heating discs to a reset position, and then controlling the two auxiliary clamping mechanisms to carry out the same-direction sliding so as to butt-joint the two end pipes with the valve seat and finish pressure-maintaining welding work; in addition, the left welding device and the right welding device are arranged above the workbench through the welding bracket, and the heating discs in the left welding device and the right welding device move between the end pipe and the valve seat in a swinging manner, so that the volume of the PE valve welding machine on the horizontal plane can be reduced, meanwhile, the space above the PE valve welding machine can be fully utilized, and secondly, the end pipe and the valve seat can be heated better; in addition, the invention has high automation degree, better welding efficiency and high welding precision.

In order to realize the structure of the main clamping mechanism and the auxiliary clamping mechanism, the main clamping mechanism comprises a main lower clamping seat, a main lower positioning opening for positioning a valve seat is formed in the top of the main lower clamping seat, a main upper clamping seat capable of swinging up and down is hinged to the rear part of the main lower clamping seat, a main upper positioning opening for pressing the valve seat is formed in the bottom of the main upper clamping seat, and a main power mechanism capable of driving the main upper clamping seat to be pressed on the top of the main upper clamping seat is arranged between the main lower clamping seat and the main upper clamping seat; the auxiliary clamping mechanism comprises an auxiliary lower clamping seat, an auxiliary lower positioning opening for positioning the end pipe is formed in the top of the auxiliary lower clamping seat, an auxiliary upper clamping seat capable of swinging up and down is hinged to the rear portion of the auxiliary lower clamping seat, an auxiliary upper positioning opening for pressing and taking the end pipe on the same side is formed in the bottom of the auxiliary upper clamping seat, and an auxiliary power mechanism capable of driving the auxiliary upper clamping seat to be pressed on the top of the auxiliary lower clamping seat on the same side is arranged between the auxiliary lower clamping seat and the auxiliary upper clamping seat; the main lower positioning opening and the auxiliary lower positioning opening are coaxially arranged.

The top surface of the workbench is provided with transverse dovetail rails positioned at the left side and the right side of the main clamping mechanism, each transverse dovetail rail on each side is correspondingly provided with a sliding seat in a sliding manner, and the auxiliary clamping mechanisms are arranged on the sliding seats on the same side; the driving mechanism comprises two telescopic cylinders which are arranged on the workbench and are symmetrically arranged at intervals left and right, and the outer ends of telescopic rods of the two telescopic cylinders are respectively connected with sliding seats on the same side; the main power mechanism comprises a telescopic oil cylinder hinged between the rear side part of the main upper clamping seat and the rear side part of the main lower clamping seat; the auxiliary power mechanism comprises a telescopic oil cylinder hinged between the rear side part of the auxiliary upper clamping seat and the rear side part of the auxiliary lower clamping seat.

In order to fully clamp the valve seat and the end pipe, the front part of the auxiliary lower clamping seat is provided with an auxiliary locking mechanism which can keep the auxiliary upper clamping seat pressed on the top of the auxiliary lower clamping seat in a pressing state; the front part of the main lower clamping seat is provided with a main locking mechanism which can keep the main upper clamping seat pressed on the top of the main lower clamping seat in a pressing state; the main locking mechanism comprises a main board body transversely connected to the front side part of the main upper clamping seat and a main support arranged on the front side part of the main lower clamping seat, a main hinge shaft transversely arranged is arranged on the main support, a main locking plate with one end extending backwards and the other end extending forwards is arranged on the main hinge shaft in a penetrating manner, a main locking oil cylinder capable of driving the rear end part of the main locking plate to swing up and down is hinged between the front end part of the main locking plate and the main lower clamping seat, and the rear end part of the main locking plate can be pressed against the top of the main board body when the main upper clamping seat is pressed on the top of the main lower clamping seat; the auxiliary locking mechanism comprises an auxiliary plate body transversely connected to the front side part of the auxiliary upper clamping seat and an auxiliary support arranged on the front side part of the auxiliary lower clamping seat, an auxiliary hinge shaft transversely arranged is arranged on the auxiliary support, an auxiliary locking plate with one end extending backwards and the other end extending forwards is arranged on the auxiliary hinge shaft in a penetrating mode, an auxiliary locking oil cylinder capable of driving the rear end of the auxiliary locking plate to swing up and down is hinged between the front end of the auxiliary locking plate and the auxiliary lower clamping seat, and the rear end of the auxiliary locking plate can be pressed against the top of the auxiliary plate body when the auxiliary upper clamping seat is pressed on the top of the auxiliary lower clamping seat.

The welding support comprises two vertical beams which are arranged at intervals left and right, the two vertical beams are symmetrically arranged on the workbench left and right along the left and right symmetrical central plane of the main clamping mechanism, and the tops of the two vertical beams are connected with a welding support plate which is arranged transversely; the top of the welding support plate is provided with a transversely arranged welding slide rail, two groups of welding slide blocks which are arranged at left and right intervals are arranged on the welding slide rail in a sliding mode, the welding slide plate of the left welding device is arranged at the top of the left welding slide block, and the welding slide plate of the right welding device is arranged at the top of the right welding slide block; the second driving device comprises two telescopic welding cylinder bodies which are symmetrically arranged at the bottom of the welding support plate in a left-right mode, two ends of the welding support plate are respectively provided with a vertical through transverse strip hole, the bottom of the welding slide plate is connected with a push-pull plate which extends downwards from the transverse strip holes at the same side, and the push-pull plate is connected with an output shaft of the telescopic welding cylinder body at the same side; the first driving device comprises a welding servo motor arranged on the welding slide plate, and an output shaft of the welding servo motor is connected with the supporting shaft.

In order to realize the structure of the heating plate, the heating plate comprises a fixed plate body, wherein the left end face and the right end face of the fixed plate body are respectively connected with a side plate body, the side plate body comprises an inner plate surface which is closely attached to the corresponding end face of the fixed plate body and an outer plate surface which is far away from one end of the fixed plate body, an annular roundabout oil duct which is densely distributed on the inner plate surface is arranged on the inner plate surface of the side plate body, the roundabout oil duct comprises an oil inlet end part and an oil outlet end part, an oil inlet pipe mounting hole which is communicated with the oil inlet end part of the left end plate body and an oil outlet pipe mounting hole which is communicated with the oil inlet end part of the right end plate body are arranged on the outer peripheral wall of the fixed plate body, and an oil through hole which is communicated with the oil outlet end part of the left end plate body and the oil outlet end part of the right end plate body is arranged on the fixed plate body; heating heads for heating the valve seat or the end pipe are respectively arranged on the outer disc surfaces of the two side disc bodies.

In order to realize the structure of circuitous oil duct, circuitous oil duct includes the minor arc shaped arc groove that many radiuses diminish and equipartition in proper order on the inner disc face, and the axis and the side disk body axis coaxial setting of many arc grooves, the both ends portion of arc groove includes head end and end, thereby the end of every arc groove all communicates to a circuitous oil duct with the head end of the less arc groove of adjacent diameter, thereby makes many arc grooves communicate to a circuitous oil duct, and the one end of circuitous oil duct that is close to side disk body peripheral wall is the oil feed tip, and the one end of circuitous oil duct that is close to side disk body axle center is the oil outlet tip.

In order to realize the structure of the heating head, the heating head comprises a substrate arranged on the outer disc surface of the side disc body, the inner plate surface of the substrate is close to the outer disc surface of the side disc body, and an annular boss is arranged on the outer plate surface of the substrate; the outer peripheral wall of the fixed disk body is provided with a section of mounting part which protrudes radially and is convenient to connect to the heating welding mechanism.

The top of the rear side part of the workbench is longitudinally provided with a plurality of longitudinal support sliding rails which are arranged at intervals in a left-right parallel manner, each longitudinal support sliding rail is connected with a longitudinal support sliding seat in a sliding manner, the cutting and flattening slide plate is arranged on the longitudinal support sliding seat, the longitudinal cutting and flattening driving mechanism comprises a longitudinal cutting and flattening cylinder longitudinally arranged on the workbench, and the outer end part of a telescopic rod of the longitudinal cutting and flattening cylinder is connected with the cutting and flattening slide plate; the top of cutting the smooth board transversely installs two piece at least horizontal support slide rails that parallel interval set up around, install two sets of horizontal support slide that the interval set up about on the horizontal support slide rail, two cut Ping Jijia install respectively on the horizontal support slide of homonymy, horizontal cut flat actuating mechanism includes two horizontal cut flat cylinder, two horizontal cuts Ping Qigang and transversely installs respectively on cutting smooth board both ends top surface, two horizontal telescopic link outer ends of cutting flat cylinder link together with the cutting flat frame of homonymy respectively.

The cutter shaft is rotatably arranged on the cutting and leveling machine frame through the middle part, and the left end part and the right end part of the cutter shaft extend out of the left side and the right side of the cutting and leveling machine frame respectively; the two end pipe cutters are respectively arranged on the cutter shaft ends on the opposite sides of the two cutter shafts, and the two valve seat cutters are respectively arranged on the cutter shaft ends on the opposite sides of the two cutter shafts; the cutter shaft is provided with a chain wheel, and the rear part of each cutting and leveling machine frame is provided with a cutter motor which drives the chain wheels on the same side to rotate through a chain.

In summary, the invention has simple structure and convenient use, and can clamp and fix valve seats and end pipes with different model sizes according to the use requirement, so the invention has high universality, and secondly, the invention can conveniently and rapidly clamp and fix the valve seat and the two end pipes, thereby improving the production efficiency, and in addition, the invention can ensure higher coaxial precision between the valve seat and the two end pipes, thereby improving the welding precision between the valve seat and the two end pipes; secondly, the heating disc heats uniformly and can accurately control the heating precision, so that the corresponding welding surfaces of the end pipe and the valve seat can be effectively heated; in addition, the valve clamping and assembling mechanism, the welding surface cutting and leveling mechanism and the heating and welding mechanism are compact and reasonable in arrangement structure.

Drawings

The invention is described in further detail below with reference to the attached drawings and detailed description:

FIG. 1 is a schematic diagram of a PE valve in a front cross-sectional configuration;

FIG. 2 is a schematic perspective view of the present invention;

FIG. 3 is a schematic perspective view of another angle of the present invention;

FIG. 4 is a schematic perspective view of a weld face trimming mechanism;

FIG. 5 is a schematic perspective view of a weld face cutting mechanism mounted on a table;

FIG. 6 is a schematic diagram of a front view of the valve clamping assembly mechanism mounted on a table;

FIG. 7 is a schematic perspective view of FIG. 6;

FIG. 8 is a schematic perspective view of a valve clamping assembly mechanism;

FIG. 9 is a schematic perspective view of another angle of the valve clamping assembly mechanism;

FIG. 10 is a schematic cross-sectional view taken along line A-A of FIG. 8;

FIG. 11 is a schematic view of a front view of a heat welding mechanism;

FIG. 12 is a schematic view showing a perspective structure in which a heat welding mechanism is mounted on a table;

FIG. 13 is a schematic view of a cross-sectional front view of a hotplate;

FIG. 14 is a left side view of the stationary platen of FIG. 13;

fig. 15 is a left-side view of the right-side tray of fig. 13.

Detailed Description

In order to facilitate understanding of the object and the structural principle of the present invention, the structure of the PE valve is described first, as shown in fig. 1, the structure of the PE valve at present generally includes a valve seat 16, a valve ball, a valve rod, two supporting retainers, two end pipes 17 located at two ends of the valve seat 16, etc., in addition, the valve ball is installed in an inner cavity of the valve seat 16, the valve rod is installed at the top of the valve seat 16 and can drive the valve ball to rotate, the end pipe 17 is a reducing pipe body with a large end diameter and a small end diameter, at the same time, the diameter of the end pipe end close to one side of the valve seat is larger than the end pipe end far from one side of the valve seat, at the same time, two opposite inner end surfaces of the two end pipes respectively form welding surfaces for connecting the two end pipes, at the same time, the end pipe 17 is connected to the valve seat 16 through the large end, and the end pipe 17 is welded at two ends of the valve seat 16 through hot melt welding, and the supporting retainers are installed between the end pipe 17 and the valve seat 16 in advance before welding; at present, the welding process of the PE valve generally comprises the processes of coaxial fixation of the valve seat 16 and the two end pipes 17, cutting and leveling of the welding surfaces of the two end pipes 17 connected with the valve seat 16, heating of the welding surfaces and pressure maintaining welding of the welding surfaces.

In summary, in order to facilitate the implementation of the welding process, as shown in fig. 2-15, the welding machine for PE valve includes a workbench 1, on which a valve clamping assembly mechanism, a welding surface trimming mechanism and a heating welding mechanism are installed.

As shown in fig. 6 to 10, the valve clamping assembly mechanism comprises a main clamping mechanism 2 fixedly connected to a workbench and used for clamping a valve seat 16, a sliding seat 4 capable of sliding left and right is respectively arranged on the top of the workbench 1 positioned on the left side and the right side of the main clamping mechanism 2, a driving mechanism 5 capable of driving the sliding seat 4 on the left side and the right side to slide left and right is arranged on the workbench 1, and a secondary clamping mechanism 3 used for clamping a pipe 17 on the same side is respectively arranged on the left sliding seat 4 and the right sliding seat 4; in order to ensure that the two sliding carriages 4 can precisely and stably slide left and right on the workbench 1, so that the assembly precision of the valve seat 16 and the two end pipes 17 is improved, the top surface of the front side part of the workbench 1 is provided with transverse dovetail rails 8 positioned on the left side and the right side of the main clamping mechanism 2, and the bottoms of the two sliding carriages 4 are respectively provided with dovetail grooves which are in sliding fit connection with the transverse dovetail rails 8 on the same side, so that the sliding connection structure of the transverse dovetail rails and the dovetail grooves can ensure the sliding precision and the stability of the sliding carriages 4; in addition, in order to drive two slide carriages 4 to slide, this actuating mechanism 5 includes two telescopic cylinder that install on workstation 1 and bilateral symmetry interval set up, as shown in fig. 8, these two telescopic cylinder can install respectively at the both ends face middle part of horizontal forked tail track 8, simultaneously, the telescopic link outer tip of two telescopic cylinders stretches to main fixture 2 direction respectively horizontally, in addition, still be equipped with the dodging heavy groove of dodging the telescopic link of two telescopic cylinders on the horizontal forked tail track 8 top surface, and the bottom of slide 4 is equipped with the connecting plate that stretches into in the heavy groove of homonymy dodging, secondly, the telescopic link outer tip and the connecting plate fixed connection of homonymy seat 4 bottom of telescopic cylinder, consequently, telescopic cylinder can push-pull connecting plate control slide 4 control slide.

6-10, the clamping structure and working principle of the main clamping mechanism 2 and the two auxiliary clamping mechanisms 3 are the same, in order to clamp the valve seat 16, the main clamping mechanism 2 comprises a main lower clamping seat, a main lower positioning opening for positioning the valve seat 16 is formed in the top of the main lower clamping seat, a main upper clamping seat capable of swinging up and down is hinged at the rear part of the main lower clamping seat, a main upper positioning opening for pressing the valve seat 16 is formed in the bottom of the main upper clamping seat, and in addition, a main power mechanism 10 capable of driving the main upper clamping seat to press the top of the main upper clamping seat is arranged between the main lower clamping seat and the main upper clamping seat, and because the outline shape of the valve seat 16 is generally circular, the main lower positioning opening and the main upper positioning opening are preferably minor arc openings, and meanwhile, after the main upper clamping seat is pressed on the top of the main lower clamping seat, the axes of the main lower positioning opening and the main upper positioning opening can be coaxially overlapped together; in addition, in order to clamp and fix the valve seat 16 with different model and size, so as to improve the universality of the invention, two left and right adjusting plates are respectively arranged in the main upper positioning opening and the main lower positioning opening at intervals, and the bottom of the upper adjusting plate and the top of the lower adjusting plate in the main clamping mechanism 2 are respectively provided with a semicircular clamping opening which is matched with the outline shape of the position to be clamped of the valve seat 16, therefore, the valve seat 16 with corresponding specification can be clamped by replacing the adjusting plates of the semicircular clamping openings with different shapes and sizes; in addition, in order to realize the structure of the main power mechanism 10, the main power mechanism 10 includes a telescopic cylinder hinged between the rear side portion of the main upper holder and the rear side portion of the main lower holder. With continued reference to the drawings, in order to sufficiently clamp the valve seat 16, a main locking mechanism capable of maintaining the main upper holder pressed on the top of the main lower holder in a pressed state is installed at the front portion of the main lower holder; the main locking mechanism comprises a main board body transversely connected to the front side part of the main upper clamping seat and a main support arranged on the front side part of the main lower clamping seat, wherein a main hinge shaft transversely arranged is arranged on the main support, a main locking plate with one end extending backwards and the other end extending forwards is arranged on the main hinge shaft in a penetrating manner, and a main locking oil cylinder capable of driving the rear end of the main locking plate to swing up and down is hinged between the front end of the main locking plate and the main lower clamping seat.

6-10, in order to clamp the end pipes 17 on two sides, the auxiliary clamping mechanism 3 comprises an auxiliary lower clamping seat 6, an auxiliary lower positioning opening for positioning the end pipes 17 is formed in the top of the auxiliary lower clamping seat 6, an auxiliary upper clamping seat 7 capable of swinging up and down is hinged to the rear part of the auxiliary lower clamping seat 6, an auxiliary upper positioning opening for pressing the end pipes 17 on the same side is formed in the bottom of the auxiliary upper clamping seat 7, and an auxiliary power mechanism 11 capable of driving the auxiliary upper clamping seat 7 to be pressed on the top of the auxiliary lower clamping seat on the same side is arranged between the auxiliary lower clamping seat 6 and the auxiliary upper clamping seat 7; because the outline shape of the end pipe 17 is generally circular, the auxiliary lower positioning opening and the auxiliary upper positioning opening are preferably minor arc openings, and meanwhile, after the auxiliary upper clamping seat 7 is pressed on the top of the auxiliary lower clamping seat 6, the axes of the auxiliary lower positioning opening and the auxiliary upper positioning opening can be coaxially overlapped; secondly, in order to ensure the coaxiality of the valve seat 16 and the two end pipes 17, the main lower positioning port and the auxiliary lower positioning port are coaxially arranged. In addition, in order to clamp and fix the end pipes 17 with different model and sizes, thereby improving the universality of the invention, two adjusting plates 9 which are arranged at left and right intervals are respectively arranged in the auxiliary upper positioning opening and the auxiliary lower positioning opening; the bottom of the upper adjusting plate 9 and the top of the lower adjusting plate 9 in the auxiliary clamping mechanism 3 are respectively provided with a semicircular clamping opening which is matched with the outline shape of the position to be clamped of the same side end pipe 17, so that the end pipe 17 with corresponding specification can be clamped by replacing the adjusting plates 9 with semicircular clamping openings with different shapes and sizes; in addition, in order to realize the structure of the sub power mechanism 11, the sub power mechanism 11 includes a telescopic cylinder hinged between the rear side portion of the sub upper holder 7 and the rear side portion of the sub lower holder 6. With continued reference to the drawings, in order to sufficiently clamp the end pipe 17, the front part of the sub lower holder 6 is provided with a sub locking mechanism capable of maintaining the sub upper holder 7 pressed on the top of the sub lower holder 6 in a pressed state, and as shown in fig. 10, the sub locking mechanism comprises a sub plate body 12 transversely connected to the front side part of the sub upper holder 7, a sub bracket 13 mounted on the front side part of the sub lower holder 6, the sub bracket 13 is provided with a sub hinge shaft transversely arranged, the sub hinge shaft is penetrated with a sub locking plate 14 with one end extending backward and the other end extending forward, and a sub locking cylinder 15 capable of driving the rear end of the sub locking plate 14 to swing up and down is hinged between the front end of the sub locking plate 14 and the sub lower holder 6; therefore, the rear end portion of the sub-lock plate 14 can be pressed against the top of the sub-plate body 12 when the sub-upper holder 7 is pressed against the top of the sub-lower holder 6, thereby locking the sub-upper holder 7 in the pressed state.

As shown in fig. 2-5, the welding surface leveling mechanism comprises leveling cutting plates 60 which are positioned at the rear side of the valve clamping assembly mechanism and are connected to the workbench in a front-back sliding manner, in order to support the leveling cutting plates 60 to slide back and forth, four longitudinal support sliding rails 65 which are arranged at intervals in parallel left and right are longitudinally arranged at the top of the rear side part of the workbench, a longitudinal support sliding seat is connected to each longitudinal support sliding rail 65 in a sliding manner, and the leveling cutting plates 60 are arranged on the longitudinal support sliding seats on the four longitudinal support sliding rails 65; in addition, the tops of the left and right sides of the cutting and leveling plate 60 are respectively connected with a cutting Ping Jijia which can slide left and right transversely, in order to realize a left and right sliding mechanism of the two cutting and leveling frames 61, the top of the cutting and leveling plate 60 is transversely provided with at least two transverse support sliding rails 67 which are arranged in parallel at intervals from front to back, each transverse support sliding rail 67 is provided with two groups of transverse support sliding seats which are arranged at intervals from left to right in a sliding manner, and the two cutting and leveling frames 61 are respectively arranged on the transverse support sliding seats on the same side; in addition, the front part of each flat cutting frame 61 is rotatably connected with a cutter shaft which is transversely arranged, the cutter shaft is rotatably arranged on the flat cutting frame 61 through the middle part, and secondly, the left end and the right end of the cutter shaft respectively extend out from the left side and the right side of the flat cutting frame 61, therefore, one end of the cutter shaft is provided with a valve seat cutter 62 for cutting a valve seat, the other end of the cutter shaft is provided with an end pipe cutter 63 for cutting an end pipe, of course, the two end pipe cutters 63 are respectively arranged on the cutter shaft ends on the opposite sides of the two cutter shafts, and the two valve seat cutters 62 are respectively arranged on the cutter shaft ends on the opposite sides of the two cutter shafts; in addition, the end pipe cutter 63 and the valve seat cutter 62 each comprise a disc-shaped cutter seat capable of being mounted on a cutter shaft, and a cutter blade for cutting a welding surface is mounted on the outer end surface of the cutter seat; in addition, a cutter motor 64 for driving the cutter shaft to rotate is mounted at the rear part of each cutting flat frame 61, and a chain wheel is mounted on the cutter shaft for driving the cutter shaft to rotate, and each cutter motor drives the chain wheel at the same side to rotate through a chain.

Secondly, a longitudinal flat cutting driving mechanism for driving the flat cutting plate 60 to slide forwards and backwards is also arranged on the workbench, and when the flat cutting plate 60 is driven to slide forwards for a certain distance by the longitudinal flat cutting driving mechanism, the valve seat cutter 62 and the end pipe cutter 63 can be pushed into the gap between the main clamping mechanism and the auxiliary clamping mechanism on the same side; in order to realize a longitudinal cutting and leveling driving mechanism, the longitudinal cutting and leveling driving mechanism comprises a longitudinal cutting Ping Qigang 66 longitudinally arranged on a workbench, and the outer end part of a telescopic rod of a longitudinal cutting and leveling cylinder 66 is connected with a cutting and leveling plate 60; in addition, a transverse flat cutting driving mechanism for driving the two flat cutting racks 61 to slide in the same direction or slide in the opposite direction is mounted on the flat cutting plate 60, the transverse flat cutting driving mechanism comprises two transverse flat cutting cylinders, two transverse flat cutting Ping Qigang are respectively and transversely mounted on the top surfaces of two end parts of the flat cutting plate 60, and simultaneously, the outer end parts of telescopic rods of the two transverse flat cutting cylinders are respectively connected with the flat cutting racks 61 on the same side.

As shown in fig. 11 to 15, the heating welding mechanism comprises a welding bracket 20 installed on a workbench 1 at the rear side of the valve clamping assembly mechanism, in order to realize the structure of the welding bracket 20, the welding bracket 20 comprises two vertical beams 27 which are arranged at intervals left and right, the two vertical beams 27 are installed on the workbench 1 in a bilateral symmetry manner along a bilateral symmetry center plane of the main clamping mechanism 2, meanwhile, a gap between the two vertical beams 27 is used for the front and back sliding movement of a welding surface cutting mechanism, and secondly, the tops of the two vertical beams 27 are commonly connected with a welding supporting plate 28 which is arranged transversely, and the height of the supporting plate is higher than the top surface of the welding surface cutting mechanism; secondly, the top of the welding bracket 20 is also connected with a left welding device 21 and a right welding device 22 which can slide left and right in a sliding way; the left welding device 21 comprises a welding slide plate 23 which is connected to the welding bracket 20 in a left-right sliding way, a transverse supporting shaft is rotatably connected to the welding slide plate 23, two bearing seats for supporting two end parts of the supporting shaft are preferably arranged on the welding slide plate 23 for the rotation of the supporting shaft, a welding arm 24 capable of swinging along the supporting shaft is fixedly connected to the middle part of the supporting shaft, and correspondingly, a first driving device 25 for driving the welding arm 24 to swing reciprocally is also arranged on the welding slide plate 23, the first driving device 25 preferably comprises a welding servo motor arranged on the welding slide plate 23, and an output shaft of the welding servo motor is connected with the supporting shaft, and of course, the first driving device 25 can also be a swinging oil cylinder; the end of the welding arm 24 is fixedly connected with a heating plate 26 which can swing to a front lower welding position when in operation and to a rear upper resetting position when not in operation, the heating plate 26 is in a disc shape, the left and right end surfaces of the heating plate 26 respectively form heating surfaces for heating the welding surface of the end pipe 17 and the welding surface of the valve seat 16, and the heating plate 26 is preferably a heating plate for heating by a heat conducting oil medium, and of course, the heating plate 26 can be an electric heating plate, and the electric heating plate is an electric heating plate with various shapes formed by casting a metal tubular electric heating element in an aluminum plate, an aluminum plate or welding or embedding the metal tubular electric heating element on the aluminum plate; in addition, in order to heat the welding surface of the end pipe 17 and the welding surface of the valve seat 16, the heating plate 26 swung to the welding position can be disposed coaxially with the end pipe 17 and the valve seat 16; as shown in fig. 11 to 12, the right welding device 22 has the same structure as the left welding device 21, and the right welding device 22 and the left welding device 21 are symmetrically arranged along the right-left symmetry center plane of the main clamping mechanism 2, so that the specific structure of the right welding device 22 is not repeated.

In addition, in order to conveniently realize the sliding connection structure of the left welding device 21 and the right welding device 22, it is preferable that the top of the welding support plate 28 is provided with two welding slide rails which are transversely arranged, and the two welding slide rails are preferably arranged at intervals from front to back, and secondly, each welding slide rail is provided with two groups of welding slide blocks which are arranged at intervals from left to right in a sliding manner, so that the welding slide plate 23 of the left welding device 21 is arranged at the top of the left welding slide block, and the welding slide plate 23 of the right welding device 22 is arranged at the top of the right welding slide block, and therefore, both the left welding device 21 and the right welding device 22 can be connected at the top of the welding support plate 28 in a sliding manner from left to right. In addition, a second driving device for driving the left welding device 21 and the right welding device 22 to slide in the same direction or in opposite directions is also arranged on the welding bracket 20, and the heating disc 26 is contacted with or separated from the welding surface of the end pipe 17 at the same side and the welding surface of the valve seat 16 at the corresponding side by driving the left welding device 21 and the right welding device 22 to slide in the same direction or in opposite directions; in order to facilitate the realization of the structure of the second driving device, the second driving device comprises two telescopic welding cylinders 29 symmetrically arranged at the bottom of the welding support plate 28, the telescopic welding cylinders 29 can be telescopic cylinders or telescopic cylinders, in addition, two ends of the welding support plate 28 are respectively provided with a vertical through transverse strip hole, the bottoms of the two welding slide plates 23 are connected with push-pull plates 30 extending downwards from the transverse strip holes at the same side, and the push-pull plates 30 at the two sides are correspondingly connected with the output shafts of the telescopic welding cylinders 29 at the same side, so that the two telescopic welding cylinders 29 drive the left welding device 21 and the right welding device 22 to slide in the same direction or in opposite directions by pushing the push-pull plates 30.

As shown in fig. 13 to 15, the heating plate 26 for heating by using the heat conducting oil medium includes a fixed plate body 40, side plate bodies 41 are respectively connected to the left and right end surfaces of the fixed plate body 40, the side plate bodies 41 are preferably connected to the fixed plate body 40 by welding, meanwhile, in order to reduce the weight of the fixed plate body 40 and the side plate body 41, the fixed plate body 40 and the side plate body 41 are both annular plate bodies, secondly, in order to conveniently install the heating plate 26 on the welding arm 24, a section of mounting portion 51 which protrudes radially and is conveniently connected to the heating welding mechanism is provided on the outer peripheral wall of the fixed plate body 40, and a plurality of mounting holes are provided on the mounting portion 51.

Secondly, the side disc body 41 comprises an inner disc surface which is closely attached to the corresponding end surface of the fixed disc body 40 and an outer disc surface which is far away from one end of the fixed disc body 40, the inner disc surface of the side disc body 41 is provided with a roundabout oil duct 42 which is annularly densely distributed on the inner disc surface, the roundabout oil duct 42 comprises an oil inlet end 43 and an oil outlet end 44, high-temperature heat conduction oil is circularly injected into the roundabout oil duct 42 to heat the side disc body 41 at two ends, and in order to realize the structure of the roundabout oil duct 42, the roundabout oil duct 42 can be in a spiral shape, at the moment, one end of the roundabout oil duct close to the outer peripheral wall of the side disc body 41 is the oil inlet end 43, and one end of the roundabout oil duct close to the axle center of the side disc body 41 is the oil outlet end 44; of course, in order to realize the structure of the roundabout oil duct 42, the roundabout oil duct may include a plurality of minor arc-shaped arc grooves with sequentially smaller radii and uniformly distributed on the inner disc surface, the axes of the plurality of arc grooves are coaxially arranged with the axis of the side disc 41, two ends of each arc groove include a head end and a tail end, the tail end of each arc groove is communicated with the head end of an arc groove with smaller adjacent diameter so as to enable the plurality of arc grooves to be communicated to one roundabout oil duct, one end of the roundabout oil duct close to the peripheral wall of the side disc 41 is an oil inlet end 43, and one end of the roundabout oil duct close to the axis of the side disc 41 is an oil outlet end 44; of course, as shown in fig. 15, the circuitous oil passage 42 may have other shapes, which will not be described.

The outer peripheral wall of the fixed disk 40 is provided with an oil inlet pipe mounting hole 45 communicating with the oil inlet end 43 of the left disk 41 and an oil outlet pipe mounting hole 46 communicating with the oil inlet end 43 of the right disk 41, and the outer peripheral wall of the fixed disk 40 is also provided with an oil passage hole 47 communicating with the oil outlet end 44 of the left disk 41 and the oil outlet end 44 of the right disk 41. In addition, heating heads 48 for heating the valve seats or end pipes are respectively mounted on the outer disk surfaces of the two side disk bodies 41; in order to conveniently realize the structure of the heating head 48, the heating head 48 comprises a base plate 49 arranged on the outer disc surface of the side disc body 41, the base plate 49 is arranged on the outer disc surface of the side disc body 41 at the same end through bolts, and meanwhile, the inner plate surface of the base plate 49 is close to the outer disc surface of the side disc body 41, so that the base plate 49 and the side disc body 41 are guaranteed to be heated fully, in addition, an annular boss 50 is arranged on the outer plate surface of the base plate 49, in order to reduce the weight of the heating head 48, the annular boss 50 can effectively heat the annular welding surfaces of the end pipe and the valve seat, and the annular outer end surface of the annular boss 50 is a heating surface for the heating end pipe and the valve seat; of course, when the heating plate is used, the heating plate and the external heat conduction oil heating device are required to be connected through the heat conduction oil inlet pipe and the heat conduction oil outlet pipe, meanwhile, the heat conduction oil inlet pipe is installed in the oil inlet pipe installation hole 45, and the heat conduction oil outlet pipe is installed in the oil outlet pipe installation hole 46, at this time, high-temperature heat conduction oil can circulate into the left roundabout oil duct 42 through the oil inlet pipe installation hole 45, and then the heat conduction oil sequentially passes through the left roundabout oil duct 42, the oil outlet end 44 of the left roundabout oil duct 42, the oil through hole 47, the oil outlet end 44 of the right roundabout oil duct 42, the oil inlet end 43 of the right roundabout oil duct 42 and the oil outlet pipe installation hole 46, and is discharged into the heat conduction oil heating device through the heat conduction oil outlet pipe, and the inner wall of the roundabout oil duct 42 can be fully and uniformly heated, so that the side plate body 41 and the heating head 48 can be fully and uniformly heated; secondly, because the circuitous oil duct 42 on the side disc 41 is convenient to process, and the wall thickness between the circuitous oil duct 42 and the outer disc surface of the side disc 41 is convenient to process and control, the outer disc surface of the side disc 41 can be ensured to have accurate and uniform heated temperature, and the heating head 48 can be ensured to be fully and uniformly heated.

When the valve seat is particularly used, the valve seat can be clamped in the main clamping mechanism, and the end pipes at two sides can be respectively clamped in the auxiliary clamping mechanisms at the same side; when the welding surfaces of two end pipes and the welding surfaces of two ends of the valve seat are required to be cut and leveled, the two auxiliary clamping mechanisms are slid to a position far away from one side of the main clamping mechanism, then the cutting and leveling plate 60 is pushed to move forwards for a certain distance through the longitudinal cutting and leveling driving mechanism, the valve seat cutter 62 and the end pipe cutter 63 are pushed into a gap between the main clamping mechanism and the auxiliary clamping mechanism on the same side, meanwhile, the valve seat cutter 62 and the end pipe cutter 63 are ensured to be coaxially arranged with the end pipes and the valve seat, then the transverse cutting and leveling driving mechanism is controlled to push the two cutting and leveling racks 61 to slide in the same direction, the valve seat cutter 62 is contacted with the welding surfaces of two ends of the valve seat, so that the welding surfaces of the two end pipes are cut and leveled, the welding surfaces of the two end pipes are enabled to be abutted against the end pipe cutters 63 on the same side, and then the two auxiliary clamping mechanisms are controlled to slide reversely after the cutting and leveling operations are completed, and then the two cutting and leveling racks 61 are controlled to slide reversely, and the valve seat cutter 60 is controlled to move to a reset position; when the welding surfaces of the two end pipes and the welding surfaces of the two ends of the valve seat are required to be heated, the two auxiliary clamping mechanisms are kept to slide to a position far away from one side of the main clamping mechanism, then the heating discs of the left welding device and the right welding device are controlled to swing to the welding position, at the moment, the heating discs swinging to the welding position, the end pipes and the valve seat are coaxially arranged, then the second driving device is controlled to enable the left welding device and the right welding device to slide in the same direction, the heating surfaces of the left heating disc and the right heating disc are respectively pressed against the welding surfaces of the two ends of the valve seat, and meanwhile, the two auxiliary clamping mechanisms are controlled to slide in the same direction, so that the welding surfaces of the two end pipes are respectively pressed against the heating surfaces of the heating discs on the same side, and at the moment, the two heating discs are respectively clamped between the end pipes on the same side and the valve seat, and therefore the welding surfaces of the two end pipes and the two ends of the valve seat can be synchronously heated; after heating for a period of time, controlling the two auxiliary clamping mechanisms to carry out reverse synchronous sliding, simultaneously controlling the left welding device and the right welding device to carry out reverse synchronous sliding, after the heating discs on two sides are separated from the welding surface of the valve seat and the welding surface of the end pipe on the same side respectively, controlling the welding arms on two sides to swing the heating discs to a reset position, and then controlling the two auxiliary clamping mechanisms to carry out the same-direction sliding so as to butt-joint the two end pipes with the valve seat and finish pressure-maintaining welding work; in addition, the left welding device and the right welding device are arranged above the workbench through the welding bracket, and the heating discs in the left welding device and the right welding device move between the end pipe and the valve seat in a swinging manner, so that the volume of the PE valve welding machine on the horizontal plane can be reduced, meanwhile, the space above the PE valve welding machine can be fully utilized, and secondly, the end pipe and the valve seat can be heated better; in addition, the invention has high automation degree, better welding efficiency and high welding precision.

In summary, the present invention is not limited to the above embodiments. Those skilled in the art can make several changes and modifications without departing from the spirit and scope of the invention, and all such changes and modifications shall fall within the scope of the invention.

Claims

1. The utility model provides a PE valve welding machine, includes the workstation, install valve centre gripping equipment mechanism, welding face and cut flat-bed machine and heat welding mechanism on the workstation, its characterized in that: the valve clamping assembly mechanism comprises a main clamping mechanism (2) fixedly connected to a workbench and used for clamping a valve seat (16), auxiliary clamping mechanisms (3) used for clamping end pipes (17) on the same side are respectively connected to the tops of the workbench (1) on the left side and the right side of the main clamping mechanism (2) in a left-right sliding mode, and driving mechanisms (5) used for driving the auxiliary clamping mechanisms (3) to slide left and right and enabling welding surfaces of the two end pipes (17) and the valve seat (16) to coaxially lean against each other are respectively arranged between the workbench (1) and the two auxiliary clamping mechanisms (3);

the welding surface flattening mechanism comprises flattening cutting plates (60) which are positioned at the rear side of the valve clamping assembly mechanism and are connected on a workbench in a front-back sliding mode, a flattening cutter Ping Jijia (61) which can slide left and right transversely is respectively connected to the tops of the left side and the right side of the flattening cutting plates (60), a cutter shaft which is arranged transversely is rotationally connected to the front part of each flattening cutting frame (61), a valve seat cutter (62) for cutting a valve seat is arranged at one end of each cutter shaft, an end pipe cutter (63) for cutting an end pipe is arranged at the other end of each cutter shaft, a cutter motor (64) for driving the cutter shaft to rotate is further arranged on each flattening cutting frame (61), a longitudinal flattening driving mechanism for driving the flattening cutting plates (60) to slide back and forth is arranged on the workbench, and when the flattening cutting plates (60) slide forwards for a certain distance, the cutter shafts (62) and the end pipe cutters (63) can be pushed into gaps of the main clamping mechanism and the auxiliary clamping mechanism on the same side, and the transverse flattening driving mechanisms for driving the two flattening cutting frames (61) to slide in the same direction or reversely;

The heating welding mechanism comprises a welding bracket (20) arranged on a workbench (1) at the rear side of the valve clamping and assembling mechanism, and the top of the welding bracket (20) is connected with a left welding device (21) and a right welding device (22) which can slide left and right in a sliding manner; the left welding device (21) comprises a welding slide plate (23) which is connected to the welding bracket (20) in a left-right sliding manner, a transversely arranged supporting shaft is connected to the welding slide plate (23) in a rotating manner, a welding arm (24) which can swing along the supporting shaft is fixedly connected to the supporting shaft, a first driving device (25) which drives the welding arm (24) to swing back and forth is arranged on the welding slide plate (23), a heating disc (26) which can swing to a front lower welding position when working and to a rear upper resetting position when not working is fixedly connected to the tail end of the welding arm (24), the heating disc (26) which swings to the welding position can be coaxially arranged with the end pipe (17) and the valve seat (16), and the left end surface and the right end surface of the heating disc (26) respectively form a welding surface for heating the end pipe (17) and a heating surface of the valve seat (16); the right welding device (22) and the left welding device (21) have the same structure, and the right welding device (22) and the left welding device (21) are symmetrically arranged along the bilateral symmetry center plane of the main clamping mechanism (2); the welding bracket (20) is also provided with a second driving device which drives the left welding device (21) and the right welding device (22) to slide in the same direction or in opposite directions so as to enable the heating disc (26) to be contacted with or separated from the welding surface of the end pipe (17) at the same side and the welding surface of the corresponding side of the valve seat (16).

2. The PE valve welding machine according to claim 1, wherein the main clamping mechanism (2) comprises a main lower clamping seat, a main lower positioning opening for positioning a valve seat is formed in the top of the main lower clamping seat, a main upper clamping seat capable of swinging up and down is hinged at the rear part of the main lower clamping seat, a main upper positioning opening for pressing the valve seat is formed in the bottom of the main upper clamping seat, and a main power mechanism (10) capable of driving the main upper clamping seat to press the top of the main upper clamping seat is arranged between the main lower clamping seat and the main upper clamping seat; the auxiliary clamping mechanism (3) comprises an auxiliary lower clamping seat (6), an auxiliary lower positioning opening for positioning the end pipe is formed in the top of the auxiliary lower clamping seat (6), an auxiliary upper clamping seat (7) capable of swinging up and down is hinged to the rear portion of the auxiliary lower clamping seat (6), an auxiliary upper positioning opening for pressing and taking the end pipe on the same side is formed in the bottom of the auxiliary upper clamping seat (7), and an auxiliary power mechanism (11) capable of driving the auxiliary upper clamping seat (7) to be pressed and combined on the top of the auxiliary lower clamping seat on the same side is arranged between the auxiliary lower clamping seat (6) and the auxiliary upper clamping seat (7); the main lower positioning opening and the auxiliary lower positioning opening are coaxially arranged.

3. The PE valve welding machine according to claim 2, wherein the top surface of the workbench (1) is provided with transverse dovetail rails (8) positioned on the left side and the right side of the main clamping mechanism (2), each transverse dovetail rail is correspondingly provided with a sliding seat in a sliding manner, and the auxiliary clamping mechanisms are arranged on the sliding seats on the same side; the driving mechanism (5) comprises two telescopic cylinders which are arranged on the workbench (1) and are symmetrically arranged at intervals left and right, and the outer ends of telescopic rods of the two telescopic cylinders are respectively connected with the sliding seat (4) on the same side; the main power mechanism (10) comprises a telescopic oil cylinder hinged between the rear side part of the main upper clamping seat and the rear side part of the main lower clamping seat; the auxiliary power mechanism (11) comprises a telescopic oil cylinder hinged between the rear side part of the auxiliary upper clamping seat (7) and the rear side part of the auxiliary lower clamping seat (6).

4. The PE valve welding machine according to claim 2, wherein the front part of the auxiliary lower clamping seat (6) is provided with an auxiliary locking mechanism capable of keeping an auxiliary upper clamping seat (7) pressed on the top of the auxiliary lower clamping seat (6) in a pressed state; the front part of the main lower clamping seat is provided with a main locking mechanism which can keep the main upper clamping seat pressed on the top of the main lower clamping seat in a pressing state; the main locking mechanism comprises a main board body transversely connected to the front side part of the main upper clamping seat and a main support arranged on the front side part of the main lower clamping seat, a main hinge shaft transversely arranged is arranged on the main support, a main locking plate with one end extending backwards and the other end extending forwards is arranged on the main hinge shaft in a penetrating manner, a main locking oil cylinder capable of driving the rear end part of the main locking plate to swing up and down is hinged between the front end part of the main locking plate and the main lower clamping seat, and the rear end part of the main locking plate can be pressed against the top of the main board body when the main upper clamping seat is pressed on the top of the main lower clamping seat; the auxiliary locking mechanism comprises an auxiliary plate body (12) transversely connected to the front side part of the auxiliary upper clamping seat (7), and an auxiliary bracket (13) mounted on the front side part of the auxiliary lower clamping seat (6), wherein an auxiliary hinge shaft transversely arranged is mounted on the auxiliary bracket (13), an auxiliary locking plate (14) with one end extending backwards and the other end extending forwards is arranged on the auxiliary hinge shaft in a penetrating manner, an auxiliary locking cylinder (15) capable of driving the rear end of the auxiliary locking plate (14) to swing up and down is hinged between the front end of the auxiliary locking plate (14) and the auxiliary lower clamping seat (6), and the rear end of the auxiliary locking plate (14) can be pressed against the top of the auxiliary plate body (12) when the auxiliary upper clamping seat (7) is pressed on the top of the auxiliary lower clamping seat (6).

5. The PE valve welding machine according to claim 1, wherein the welding bracket (20) comprises two vertical beams (27) which are arranged at intervals left and right, the two vertical beams (27) are symmetrically arranged on the workbench (1) left and right along the left and right symmetrical central plane of the main clamping mechanism (2), and the tops of the two vertical beams (27) are commonly connected with a welding support plate (28) which is transversely arranged; the top of the welding supporting plate (28) is provided with a transversely arranged welding sliding rail, two groups of welding sliding blocks which are arranged at left and right intervals are arranged on the welding sliding rail in a sliding mode, a welding sliding plate (23) of the left welding device (21) is arranged at the top of the left welding sliding block, and a welding sliding plate (23) of the right welding device (22) is arranged at the top of the right welding sliding block; the second driving device comprises two telescopic welding cylinders (29) which are symmetrically arranged at the bottom of a welding support plate (28), two ends of the welding support plate (28) are respectively provided with a vertical through transverse strip hole, the bottom of the welding slide plate (23) is connected with a push-pull plate (30) which extends downwards from the transverse strip hole at the same side, and the push-pull plate (30) is connected with an output shaft of the telescopic welding cylinder (29) at the same side; the first driving device (25) comprises a welding servo motor arranged on the welding sliding plate (23), and an output shaft of the welding servo motor is connected with the supporting shaft.

6. The PE valve welding machine as set forth in claim 1, wherein the heating plate (26) comprises a fixed plate body (40), side plate bodies (41) are respectively connected to the left end face and the right end face of the fixed plate body (40), the side plate bodies (41) comprise inner plate surfaces which are sealed and lean against the corresponding end faces of the fixed plate body (40) and outer plate surfaces which are far away from one end of the fixed plate body (40), an annular detour oil duct (42) which is densely distributed on the inner plate surfaces of the side plate bodies (41) is arranged on the inner plate surfaces of the side plate bodies (41), the detour oil duct (42) comprises an oil inlet end part (43) and an oil outlet end part (44), an oil inlet pipe mounting hole (45) which is communicated with the oil inlet end part (43) of the left end plate body (41) and an oil outlet pipe mounting hole (46) which is communicated with the oil outlet end part (43) of the right end plate body (41) are arranged on the outer peripheral wall of the fixed plate body (40); heating heads (48) for heating the valve seat or the end pipe are respectively arranged on the outer disc surfaces of the two side disc bodies (41).

7. The PE valve welding machine according to claim 6, wherein the circuitous oil duct comprises a plurality of minor-arc-shaped arc grooves with sequentially smaller radiuses and uniformly distributed on the inner disc surface, the axes of the arc grooves and the axes of the side disc bodies (41) are coaxially arranged, two end parts of each arc groove comprise a head end and a tail end, the tail end of each arc groove is communicated with the head end of an adjacent arc groove with smaller diameter so that the arc grooves are communicated to one circuitous oil duct, one end of the circuitous oil duct close to the peripheral wall of the side disc body (41) is an oil inlet end part (43), and one end of the circuitous oil duct close to the axis of the side disc body (41) is an oil outlet end part (44).

8. The PE valve welding machine according to claim 6, wherein the heating head (48) comprises a base plate (49) arranged on the outer disc surface of the side disc body (41), the inner plate surface of the base plate (49) is close to the outer disc surface of the side disc body (41), and an annular boss (50) is arranged on the outer disc surface of the base plate (49); the outer peripheral wall of the fixed disc body (40) is provided with a section of mounting part (51) which protrudes radially and is convenient to connect to the heating welding mechanism.

9. The PE valve welding machine according to claim 1, wherein a plurality of longitudinal support sliding rails (65) are longitudinally arranged at the top of the rear side part of the workbench at intervals in a left-right parallel manner, a longitudinal support sliding seat is connected to each longitudinal support sliding rail (65) in a sliding manner, the cutting and leveling plate (60) is arranged on the longitudinal support sliding seat, the longitudinal cutting and leveling driving mechanism comprises a longitudinal cutting Ping Qigang (66) longitudinally arranged on the workbench, and the outer end part of a telescopic rod of the longitudinal cutting Ping Qigang (66) is connected with the cutting and leveling plate (60); the top of surely smooth board (60) transversely installs two piece at least horizontal support slide rails (67) that parallel interval set up around, install two sets of horizontal support slide that the interval set up about on horizontal support slide rail (67), two surely smooth frame (61) are installed respectively on the horizontal support slide of homonymy, horizontal surely smooth actuating mechanism includes two horizontal surely smooth cylinders, and two horizontal surely Ping Qigang are transversely installed respectively on surely smooth board (60) both ends top surface, and the telescopic link outer tip of two horizontal surely smooth cylinders is in the same place with cutting Ping Jijia (61) of homonymy respectively.

10. The PE valve welding machine according to claim 9, wherein the cutter shaft is rotatably mounted on the cutter Ping Jijia (61) through a middle portion, and left and right end portions of the cutter shaft extend from left and right sides of the cutter Ping Jijia (61), respectively; the two end pipe cutters (63) are respectively arranged on the cutter shaft ends on the opposite sides of the two cutter shafts, and the two valve seat cutters (62) are respectively arranged on the cutter shaft ends on the opposite sides of the two cutter shafts; the cutter shaft is provided with a chain wheel, and the rear part of each cutting and leveling machine frame (61) is provided with a cutter motor which drives the chain wheels on the same side to rotate through a chain.