CN113427184A

CN113427184A - Manual pallet truck welding device

Info

Publication number: CN113427184A
Application number: CN202110984731.4A
Authority: CN
Inventors: 王京武
Original assignee: Shandong Shanyu Heavy Industry Machinery Co ltd
Current assignee: Shandong Shanyu Heavy Industry Machinery Co ltd
Priority date: 2021-08-26
Filing date: 2021-08-26
Publication date: 2021-09-24
Anticipated expiration: 2041-08-26
Also published as: CN113427184B

Abstract

The invention discloses a manual pallet truck welding device, and relates to the technical field of pallet truck welding. The motor-driven rotary table comprises a housing, be provided with first motor, carousel and centre frame on the casing, first motor sets up the bottom at the casing, the carousel sets up at the middle part of casing and rotates with the casing to be connected, just the output shaft of first motor and the bottom fixed connection of carousel, the centre frame sets up the top at the casing, the both sides of centre frame all are provided with welding assembly, be provided with second motor, two-way screw rod, first locating component and two second locating component in the centre frame. The welding gun can adaptively change the welding angle of the welding gun according to the angles of different trapezoid blocks, so that the welding gun is always welded in the middle of a welding included angle, the formation of a welding seam is ensured, the welding effect is improved, the angle adjustment of the welding gun and the transverse positioning of the trapezoid blocks are simultaneously carried out, the welding steps are simplified, and the working efficiency during welding is improved.

Description

Manual pallet truck welding device

Technical Field

The invention relates to the technical field of pallet truck welding, in particular to a manual pallet truck welding device.

Background

The manual pallet truck is simple, convenient and effective logistics carrying equipment. The welding production mode of the existing pallet truck of an enterprise realizes the automatic welding of the truck frame to a certain extent, wherein the end part of the pallet truck welded with the trapezoidal block is an important ring in welding.

The Chinese patent with the publication number of CN103801888A discloses an automatic welding device of a lifting type manual pallet truck, which comprises a base, a position changing machine base and a welding robot, wherein the position changing machine base is positioned on one side of the pallet truck base, the welding robot is positioned on the other side of the pallet truck base, the pallet truck base is used for roughly positioning the manual pallet truck, the position changing machine base comprises a pallet truck tooling frame, the pallet truck tooling frame is used for finely positioning and clamping the manual pallet truck, the pallet truck tooling frame is a frame body horizontally extending along the y direction on the front side of the pallet truck tooling frame, and the pallet truck tooling frame can drive the manual pallet truck to move up and down and rotate along the position changing machine base. The welding processing procedure of the manual pallet truck is greatly reduced, and the area of a processing field is effectively saved; the production efficiency and the processing quality of the manual pallet truck welding processing are improved; the welding processing specification of the manual pallet truck is increased; the number of workers and labor intensity are reduced, the limitation is made up or reduced by the electromechanical integration design idea, and a scheme is provided for automatic flexible welding processing of the manual pallet truck.

However, the above scheme has the following technical problems:

(1) the welding rifle head in this scheme can't make the angular adjustment of adaptability to the different angles of trapezoidal piece lateral wall, has influenced the shaping of welding seam for welding effect receives the influence.

(2) The positioning system in the scheme is complex in structure and complex in operation, not only is the cost of equipment increased, but also the positioning time of the manual pallet truck during welding is prolonged, and therefore the welding efficiency is reduced.

Disclosure of Invention

The invention aims to provide a manual pallet truck welding device to solve the technical problems in the prior art.

The invention provides a manual pallet truck welding device which comprises a shell, wherein a first motor, a rotary table and a central frame are arranged on the shell, the first motor is arranged at the bottom of the shell, a sliding groove is formed in the inner wall of the shell, the rotary table is rotationally connected with the sliding groove, an output shaft of the first motor is fixedly connected with the bottom of the rotary table, the central frame is arranged at the top of the shell, welding assemblies are arranged on two sides of the central frame, a second motor, a two-way screw rod, a first positioning assembly and two second positioning assemblies are arranged in the central frame, the central frame is composed of two symmetrically arranged supporting frames, the second motor is arranged on one side of one of the two supporting frames, the two-way screw rod penetrates through the two supporting frames, one end of the two-way screw rod is fixedly connected with the output end of the second motor, the first positioning assembly is arranged between the two supporting frames, two second locating component sets up respectively in two support frames, first locating component includes driving gear, driven gear, drive belt, two pivots and two splint, two the pivot runs through two support frames respectively, and two the pivot sets up in the both sides of two-way screw rod, every the one end of splint is all established in the pivot that corresponds, the middle part at two-way screw rod is established to the driving gear cover, driven gear overlaps and is established in one of them pivot, the drive belt cover is established in two-way screw rod and another pivot, every the inboard of splint all is provided with the part of rectifying.

Further, second locating component is including removing frame, locating plate and regulating plate, the top cover that removes the frame establish the one end of two-way screw rod and with two-way screw rod threaded connection, locating plate and regulating plate all set up in removing the frame and rotate with removing the frame and be connected, the locating plate sets up the inboard at removing the frame, locating plate one side is provided with first gear, one side of regulating plate is provided with the second gear, first gear and second gear meshing.

Further, the circumference of the first gear is half of the circumference of the second gear.

Further, the welding subassembly includes cylinder, movable block, telescopic link, sliding disk and welding rifle, the movable block set up in one side of centre frame and with the top sliding connection of casing, the cylinder sets up the side at the movable block, just one side fixed connection of output and movable block of cylinder, the telescopic link sets up in the movable block, and the removal end of telescopic link sets up towards the centre frame, one side of link and the removal end fixed connection of telescopic link, the both sides of sliding disk are articulated with the both ends of link respectively, the opposite side of regulating plate is provided with two T-shaped blocks, one side of sliding disk all is provided with two T-shaped grooves, every the equal block of T-shaped block is in the T-shaped inslot that corresponds, sliding disk and the regulating plate sliding fit of homonymy, the welding rifle sets up the bottom at the sliding disk.

Further, the deviation rectifying component comprises a square hole, an elastic gasket and two springs, the square hole is formed in the inner side of the clamping plate, the elastic gasket is arranged in the square hole in a sliding mode, and the two springs are arranged on the two sides of the elastic gasket respectively.

Further, the top of casing is seted up and is held the passageway of tray frame and welding gun motion.

Furthermore, the side of the shell is provided with a through groove for accommodating the movement of the tray frame.

Compared with the prior art, the invention has the beneficial effects that:

(1) according to the invention, when the trapezoidal block is positioned, the transverse positioning and the longitudinal positioning are simultaneously carried out, and due to the arrangement of the deviation rectifying component, after the trapezoidal block is longitudinally aligned with the end part of the tray frame, the trapezoidal block is allowed to transversely move when the trapezoidal block is transversely aligned with the end part of the tray frame, the two clamping plates always keep the longitudinal fixation of the trapezoidal block, only the elastic gasket transversely moves along with the trapezoidal block, so that the transverse positioning and the longitudinal positioning of the trapezoidal block can be simultaneously carried out, the positioning mode of the trapezoidal block is simplified, the equipment cost is reduced, the positioning time of the trapezoidal block is shortened, and the welding efficiency is improved.

(2) The invention transversely positions the trapezoid blocks by the second positioning assembly, simultaneously, the first gear is meshed with the second gear, so that the adjusting plate rotates along with the positioning plate when the positioning plate rotates, the sliding disc is driven to move along with the adjusting plate due to the clamping of each T-shaped block and the corresponding T-shaped groove, the rotating angles of the welding gun on the sliding disc and the adjusting plate are the same, and the rotating angle of the adjusting plate is half of the rotating angle of the positioning plate by designing the circumference of the first gear to be half of the circumference of the second gear, namely the rotating angle of the welding gun is also half of the rotating angle of the positioning plate, the welding device can adaptively change the welding angle of the welding gun according to the angles of different trapezoid blocks, so that the welding gun is always welded in the middle of the welding included angle, the formation of a welding seam is ensured, and the welding effect is improved, and the angle adjustment of the welding gun and the transverse positioning of the trapezoidal block are carried out simultaneously, so that the welding steps are simplified, and the working efficiency during welding is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a perspective view of the present invention;

FIG. 2 is a first partial schematic of the present invention;

FIG. 3 is a second partial structural view of the present invention;

FIG. 4 is an exploded view of a second positioning assembly and welding assembly;

FIG. 5 is a schematic structural diagram of a deviation correcting assembly;

fig. 6 is an exploded view of the housing.

Reference numerals: 1. a housing; 2. a first motor; 3. a turntable; 4. a center frame; 5. a second motor; 6. a bidirectional screw; 7. a first positioning assembly; 8. a second positioning assembly; 9. welding the assembly; 10. a channel; 11. a through groove; 41. a support frame; 71. a driving gear; 72. a driven gear; 73. a transmission belt; 74. a rotating shaft; 75. a splint; 76. a deviation rectifying component; 77. a square hole; 78. an elastic pad; 79. a spring; 81. a movable frame; 82. positioning a plate; 83. an adjusting plate; 84. a first gear; 85. a second gear; 86. a T-shaped block; 87. a T-shaped slot; 91. a cylinder; 92. a moving block; 93. a telescopic rod; 94. a connecting frame; 95. a sliding disk; 96. and (4) welding the gun.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention.

The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention.

All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 1 to 6, an embodiment of the present invention provides a manual pallet truck welding device, which includes a housing 1, wherein a first motor 2, a rotating disc 3, and a center frame 4 are disposed on the housing 1, the first motor 2 is disposed at the bottom of the housing 1, a sliding slot is disposed on an inner wall of the housing 1, the rotating disc 3 is rotatably connected to the sliding slot, an output shaft of the first motor 2 is fixedly connected to the bottom of the rotating disc 3, the center frame 4 is disposed at the top of the housing 1, welding assemblies 9 are disposed on two sides of the center frame 4, a second motor 5, a two-way screw 6, a first positioning assembly 7, and two second positioning assemblies 8 are disposed in the center frame 4, the center frame 4 is composed of two symmetrically disposed support frames 41, the second motor 5 is disposed on one side of one of the support frames 41, the two-way screw 6 penetrates through the two support frames 41, and the one end of two-way screw rod 6 and the output fixed connection of second motor 5, first locating component 7 sets up between two support frames 41, two second locating component 8 sets up respectively in two support frames 41, first locating component 7 includes driving gear 71, driven gear 72, drive belt 73, two pivot 74 and two splint 75, two pivot 74 runs through two support frames 41 respectively, and two pivot 74 sets up in the both sides of two-way screw rod 6, every one end of splint 75 is all established on corresponding pivot 74, driving gear 71 cover is established at the middle part of two-way screw rod 6, driven gear 72 cover is established on one of them pivot 74, drive belt 73 cover is established on two-way screw rod 6 and another pivot 74, every the inboard of splint 75 all is provided with deviation correcting part 76. During the use, place the tray frame on carousel 3 earlier, make the tip of tray frame place under centre frame 4, and preliminarily place the trapezoidal piece at the tip of tray frame, then start the second motor 5 of centre frame 4 one side, make two-way screw 6 rotate, because two pivots 74 set up about two-way screw 6 horizontal symmetry, the one end of every splint 75 all overlaps on corresponding pivot 74, driving gear 71 overlaps the middle part at two-way screw 6, driven gear 72 overlaps on one of them pivot 74, drive belt 73 overlaps on two-way screw 6 and another pivot 74, make when two-way screw 6 rotates, two splint 75 simultaneously downstream and press from both sides tight trapezoidal piece through the elastic gasket 78 in the part of rectifying 76, make trapezoidal piece vertically align with tray frame tip.

Specifically, second locating component 8 is including removing frame 81, locating plate 82 and regulating plate 83, the top cover that removes frame 81 establish two-way screw rod 6 one end and with two-way screw rod 6 threaded connection, locating plate 82 and regulating plate 83 all set up in removing frame 81 and with remove frame 81 and rotate and be connected, locating plate 82 sets up the inboard at removing frame 81, locating plate 82 one side is provided with first gear 84, one side of regulating plate 83 is provided with second gear 85, first gear 84 meshes with second gear 85. Because the screw thread direction at two ends of the two-way screw rod 6 is opposite, and the moving frames 81 on two sides of the central frame 4 are respectively in threaded connection with one end of the two-way screw rod 6, so that the two moving frames 81 move inwards at the same time, and finally the positioning plate 82 is abutted and pressed on the trapezoidal block, so that the trapezoidal block is transversely aligned with the end part of the tray frame. When the second positioning assembly 8 transversely positions the trapezoidal blocks, the first gear 84 is engaged with the second gear 85, so that when the positioning plate 82 rotates, the adjusting plate 83 rotates together with the positioning plate 82, and each T-shaped block 86 is engaged with the corresponding T-shaped groove 87, so that the sliding disc 95 is driven to move together with the adjusting plate 83, and the rotation angles of the welding gun 96 on the sliding disc 95 and the adjusting plate 83 are the same.

Specifically, the circumference of the first gear 84 is one-half of the circumference of the second gear 85. Through designing first gear 84 to be the half of second gear 85 size, make the turned angle of regulating plate 83 be the half of locating plate 82 turned angle, the turned angle of welding rifle 96 also is the half of locating plate 82 turned angle promptly, make this welding set can change welding rifle 96's welding angle according to the angle adaptability of the trapezoidal piece of difference through this structure, make welding rifle 96 be in welded optimum angle all the time, the welding seam is formed has been guaranteed, the welding effect has been improved, and welding rifle 96's angle modulation and the transverse positioning of trapezoidal piece go on simultaneously, the welding step has been simplified, work efficiency when welding has been improved.

Specifically, the welding assembly 9 includes an air cylinder 91, a moving block 92, an expansion link 93, a connecting frame 94, a sliding disk 95 and a welding gun 96, the moving block 92 is disposed on one side of the central frame 4 and slidably connected to the top of the housing 1, the air cylinder 91 is disposed beside the moving block 92, an output end of the air cylinder 91 is fixedly connected to one side of the moving block 92, the expansion link 93 is disposed in the moving block 92, a moving end of the expansion link 93 is disposed toward the central frame 4, one side of the connecting frame 94 is fixedly connected to a moving end of the expansion link 93, two sides of the sliding disk 95 are respectively hinged to two ends of the connecting frame 94, two T-shaped blocks 86 are disposed on the other side of the adjusting plate 83, two T-shaped grooves 87 are disposed on one side of the sliding disk 95, each T-shaped block 86 is engaged in a corresponding T-shaped groove 87, and the sliding disk 95 is slidably engaged with the adjusting plate 83 on the same side, the welding gun 96 is disposed at the bottom of the sliding tray 95. And (3) welding after the trapezoidal block is positioned, starting the air cylinders 91 on two sides of the central frame 4, pushing the moving block 92 to slide on the shell 1, matching the T-shaped groove 87 to enable the sliding disc 95 to slide on the T-shaped block 86, and enabling the welding gun 96 below the sliding disc 95 to perform welding. And (3) welding after the trapezoidal block is positioned, starting the air cylinders 91 on two sides of the central frame 4, pushing the moving block 92 to slide on the shell 1, matching the T-shaped groove 87 to enable the sliding disc 95 to slide on the T-shaped block 86, and enabling the welding gun 96 below the sliding disc 95 to perform welding.

Specifically, the deviation correcting component 76 includes a square hole 77, an elastic washer 78 and two springs 79, the square hole 77 is opened on the inner side of the clamping plate 75, the elastic washer 78 is slidably disposed in the square hole 77, and the two springs 79 are disposed on two sides of the elastic washer 78 respectively. Due to the arrangement of the deviation rectifying component 76, after the trapezoidal block is longitudinally aligned with the end part of the tray frame, when the trapezoidal block is transversely aligned with the end part of the tray frame, the trapezoidal block moves transversely, the two clamping plates 75 always keep the longitudinal fixation of the trapezoidal block, and only the elastic gasket 78 moves transversely along with the trapezoidal block, so that the transverse positioning and the longitudinal positioning of the trapezoidal block can be simultaneously carried out, the positioning mode of the trapezoidal block is simplified, the equipment cost is reduced, the positioning time of the trapezoidal block is shortened, and the welding efficiency is improved.

Specifically, the top of the housing 1 is opened with a channel 10 for accommodating the pallet carriage and the movement of the welding gun 96. The channel 10 is arranged, so that more operation space is provided for welding work, and the welding effect is ensured.

Specifically, a through groove 11 for accommodating the movement of the pallet frame is formed at the side of the housing 1. The through groove 11 that the casing 1 side was seted up can allow the length of tray frame slightly longer than the radius of carousel 3 for this device can adapt to the tray frame of not unidimensional, has increased the practicality of device.

The working principle is as follows: when in use, firstly, the pallet frame is placed on the turntable 3 positioned below the channel 10, the end part of the pallet frame is placed under the central frame 4, the trapezoidal block is preliminarily placed at the end part of the pallet frame, then the second motor 5 at one side of the central frame 4 is started, the two-way screw 6 rotates, because the two rotating shafts 74 are horizontally and symmetrically arranged relative to the two-way screw 6, one end of each clamping plate 75 is sleeved on the corresponding rotating shaft 74, the driving gear 71 is sleeved on the middle part of the two-way screw 6, the driven gear 72 is sleeved on one rotating shaft 74, the driving belt 73 is sleeved on the two-way screw 6 and the other rotating shaft 74, when the two-way screw 6 rotates, the two clamping plates 75 simultaneously move downwards and clamp the trapezoidal block through the elastic gasket 78 in the deviation correcting part 76, so that the trapezoidal block is longitudinally aligned with the end part of the pallet frame, meanwhile, the thread directions of the two ends of the two-way screw 6 are opposite, and the removal frame 81 of centre frame 4 both sides respectively with the one end threaded connection of two-way screw rod 6 to make two removal frame 81 simultaneously inwards move, finally make locating plate 82 conflict and compress tightly the trapezoidal piece, make the trapezoidal piece transversely align with tray frame tip, because the setting of part 76 of rectifying, after the trapezoidal piece vertically aligns with tray frame tip, allow when the trapezoidal piece transversely aligns with tray frame tip, the trapezoidal piece carries out lateral shifting, and two splint 75 remain the longitudinal fixation to the trapezoidal piece all the time, only elastic gasket 78 is along with the transverse movement of trapezoidal piece, this structure has simplified the locate mode of trapezoidal piece, the equipment cost has been reduced, and the location time of trapezoidal piece has been reduced, welding efficiency has been improved.

When the second positioning component 8 transversely positions the trapezoid blocks, the first gear 84 is meshed with the second gear 85, so that when the positioning plate 82 rotates, the adjusting plate 83 rotates along with the positioning plate 82, and each T-shaped block 86 is clamped with the corresponding T-shaped groove 87 to drive the sliding disc 95 to move along with the adjusting plate 83, and the rotating angles of the welding gun 96 on the sliding disc 95 and the adjusting plate 83 are the same, and by designing the first gear 84 to be one half of the size of the second gear 85, the rotating angle of the adjusting plate 83 is one half of the rotating angle of the positioning plate 82, namely the rotating angle of the welding gun 96 is also one half of the rotating angle of the positioning plate 82, through the structure, the welding device can adaptively change the welding angle of the welding gun 96 according to the angles of different trapezoid blocks, so that the welding gun 96 is always welded in the middle of an included angle, and the formation of a welding seam is ensured, the welding effect is improved, the angle adjustment of the welding gun 96 and the transverse positioning of the trapezoidal block are carried out simultaneously, the welding steps are simplified, and the working efficiency during welding is improved.

And (3) welding after the trapezoidal block is positioned, starting the air cylinders 91 on two sides of the central frame 4, pushing the moving block 92 to slide on the shell 1, matching the T-shaped groove 87 to enable the sliding disc 95 to slide on the T-shaped block 86, and enabling the welding gun 96 below the sliding disc 95 to perform welding.

After welding the both sides of trapezoidal piece, start first motor 2, make 3 rotatory ninety degrees of carousel, continue to weld the other both sides of trapezoidal piece through above-mentioned step, give unnecessary details here, accomplish welding back through first motor 2 and order about carousel 3 and reset at the trapezoidal piece, in order to take out the tray frame that the welding is good, and logical groove 11 that 1 side of casing was seted up can allow the length of tray frame slightly longer than the radius of carousel 3, make this device can adapt to not unidimensional tray frame, the practicality of device has been increased.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A manual pallet truck welding device comprises a shell (1) and is characterized in that a first motor (2), a rotary table (3) and a center frame (4) are arranged on the shell (1), the first motor (2) is arranged at the bottom of the shell (1), a sliding groove is formed in the inner wall of the shell (1), the rotary table (3) is rotatably connected with the sliding groove, an output shaft of the first motor (2) is fixedly connected with the bottom of the rotary table (3), the center frame (4) is arranged at the top of the shell (1), welding assemblies (9) are arranged on two sides of the center frame (4), a second motor (5), a two-way screw (6), a first positioning assembly (7) and two second positioning assemblies (8) are arranged in the center frame (4), and the center frame (4) is composed of two symmetrically arranged support frames (41), the second motor (5) is arranged on one side of one support frame (41), the two-way screw (6) penetrates through the two support frames (41), one end of the two-way screw (6) is fixedly connected with the output end of the second motor (5), the first positioning assembly (7) is arranged between the two support frames (41), the two second positioning assemblies (8) are respectively arranged in the two support frames (41), the first positioning assembly (7) comprises a driving gear (71), a driven gear (72), a transmission belt (73), two rotating shafts (74) and two clamping plates (75), the two rotating shafts (74) respectively penetrate through the two support frames (41), the two rotating shafts (74) are arranged on two sides of the two-way screw (6), one end of each clamping plate (75) is sleeved on the corresponding rotating shaft (74), the driving gear (71) is sleeved on the middle part of the two-way screw (6), the driven gear (72) is sleeved on one of the rotating shafts (74), the transmission belt (73) is sleeved on the two-way screw (6) and the other rotating shaft (74), and the inner side of each clamping plate (75) is provided with a deviation rectifying component (76).

2. The manual pallet truck welding device according to claim 1, characterized in that the second positioning assembly (8) comprises a moving frame (81), a positioning plate (82) and an adjusting plate (83), the top of the moving frame (81) is sleeved at one end of the bidirectional screw (6) and is in threaded connection with the bidirectional screw (6), the positioning plate (82) and the adjusting plate (83) are both arranged in the moving frame (81) and are in rotational connection with the moving frame (81), the positioning plate (82) is arranged on the inner side of the moving frame (81), a first gear (84) is arranged on one side of the positioning plate (82), a second gear (85) is arranged on one side of the adjusting plate (83), and the first gear (84) is meshed with the second gear (85).

3. Manual pallet truck welding device according to claim 2, characterized in that the circumference of said first gear wheel (84) is half the circumference of said second gear wheel (85).

4. The manual pallet truck welding device according to claim 2, characterized in that the welding assembly (9) comprises an air cylinder (91), a moving block (92), an expansion link (93), a connecting frame (94), a sliding disc (95) and a welding gun (96), the moving block (92) is arranged on one side of the central frame (4) and is in sliding connection with the top of the shell (1), the air cylinder (91) is arranged on the side of the moving block (92), the output end of the air cylinder (91) is fixedly connected with one side of the moving block (92), the expansion link (93) is arranged in the moving block (92), the moving end of the expansion link (93) is arranged towards the central frame (4), one side of the connecting frame (94) is fixedly connected with the moving end of the expansion link (93), two sides of the sliding disc (95) are respectively hinged with two ends of the connecting frame (94), and the other side of the adjusting plate (83) is provided with two T-shaped blocks (86), one side of the sliding disc (95) is provided with two T-shaped grooves (87), each T-shaped block (86) is clamped in the corresponding T-shaped groove (87), the sliding disc (95) is in sliding fit with the adjusting plate (83) on the same side, and the welding gun (96) is arranged at the bottom of the sliding disc (95).

5. Manual pallet truck welding device according to claim 1, characterized in that said deviation rectifying member (76) comprises a square hole (77), an elastic washer (78) and two springs (79), said square hole (77) is opened on the inner side of the clamping plate (75), said elastic washer (78) is slidingly arranged in the square hole (77), two springs (79) are respectively arranged on both sides of the elastic washer (78).

6. Manual pallet truck welding device according to claim 4, characterized in that the top of the housing (1) opens a channel (10) accommodating the pallet truck and the movement of the welding gun (96).

7. Manual pallet truck welding device according to claim 1, characterized in that the housing (1) is flanked by through slots (11) accommodating pallet truck movements.