A process method for controlling welding deformation of a hook arm

Abstract

The present invention discloses a process method for controlling welding deformation of a hook arm. The hook arm includes at least one arm body. The lower cover plate, left side plate, right side plate and upper cover plate of the arm body are clamped in the middle by a welding fixture to form a frame shape and fit together with each other. An inner cavity positioning member is placed in the inner cavity of the arm body. Spot welding is performed at the side joint seams of the four components, and then continuous welding is performed along the same direction at each side joint seam to complete the welding process. The process method for controlling welding deformation of the hook arm provided by the present invention can ensure that the dimensional tolerances of the front arm and vertical arm of the hook arm after welding are within ±0.5 mm, and there is no distortion, so that the post-welding correction process can be omitted.

Description

Technical Field

[0001] The present invention relates to the field of hook arm production, and particularly to a process method for controlling welding deformation of a hook arm. Background Art

[0002] The hook arm structure is commonly used in special vehicles or large lifting tools. The plate thickness of the hook arm assembly is basically in the range of 4 - 8 mm, and the material is S460MC. The original welding method was to directly weld one side after another according to the convention. After welding, there were problems such as large deformation, overall distortion, and the need for post-welding correction. Moreover, the dimensions could not be guaranteed within the tolerance of ±0.5 mm, and the L-shaped structure was not perpendicular, and the hook head was asymmetric with the hook arm reference after welding, and the symmetry could not be guaranteed within 3 mm. In addition, the original welding method had low production efficiency, was difficult to achieve mass production, and had poor product consistency. Summary of the Invention

[0003] The purpose of the present invention is to provide a process method for controlling welding deformation of a hook arm, in which the dimensional tolerance of the front arm and the vertical arm of the hook arm can be guaranteed within ±0.5 mm after welding, and there is no distortion, and the post-welding correction process can be omitted.

[0004] To achieve the above purpose, the present invention provides a process method for controlling welding deformation of a hook arm. The hook arm includes at least one arm body; the lower cover plate, the left side plate, the right side plate, and the upper cover plate of the arm body are clamped in the middle by a welding fixture to form a frame shape and fit together, and an inner cavity positioning member is placed in the inner cavity of the arm body; spot welding is performed at the side splicing seams of the four components, and then continuous welding is performed on each side splicing seam in the same direction to complete the welding and assembly process.

[0005] As a further improvement of the present invention, the lower cover plate of the arm body is placed on the bottom plate of the welding fixture; the left side plate and the right side plate of the arm body are arranged oppositely, and one of their outer side walls is positioned by the side plate positioning component of the welding fixture, and the other outer side wall is pressed by the pressing rod component of the welding fixture; the upper cover plate is attached to the left side plate and the right side plate through the pressing plate screw component and the upper pressing plate of the welding fixture.

[0006] As a further improvement of the present invention, the arm body includes a front arm and a vertical arm; after the front arm and the vertical arm complete the welding and assembly process, a hook arm basic assembly step is carried out: the front arm and the vertical arm are placed on the assembly fixture for positioning and fitting to form a hook arm base, and then spot welding is performed at their splicing seams; the front arm and the vertical arm are temporarily connected by a first reinforcing rib; then continuous welding is performed at the splicing seams of the front arm and the vertical arm; after welding is completed, the first reinforcing rib is removed.

[0007] As a further improvement of the present invention, when carrying out the hook arm basic assembly step, the hook arm base is placed on the assembly bottom plate of the assembly fixture, the outside of the hook arm base is positioned by the assembly positioning member, and the inside of the hook arm base is pressed by the assembly pressing rod component.

[0008] As a further improvement of the present invention, after the hook arm foundation assembly step is completed, a hook head welding step is carried out: place the hook arm foundation and the hook head on the assembly fixture, position and fit one end of the vertical arm with the hook head, and then spot weld the joint seam between the two; temporarily connect the hook head and the hook arm foundation through a second reinforcing rib; then continuously weld the joint seam between the vertical arm and the hook head; after welding, remove the second reinforcing rib.

[0009] As a further improvement of the present invention, the hook head is provided with a positioning hole, and the assembly fixture is provided with a hook head positioning component. The hook head positioning component includes a hook head backing plate and a positioning protrusion, and the positioning protrusion of the hook head positioning component corresponds to the positioning hole of the hook head.

[0010] As a further improvement of the present invention, when the front arm is clamped by the welding fixture, bushings are placed on the through holes corresponding to the left and right side plates of the front arm, and the positioning shaft passes through the bushings on both sides at the same time. A positioning shaft sleeve is also sleeved on the positioning shaft, and both ends of the positioning shaft sleeve are in contact with the inner end faces of the bushings on both sides respectively; the outer end faces of the bushings on both sides are clamped by a first pressing rod assembly and a first lateral positioning member respectively; then the bushings are welded to the left and right side plates together.

[0011] As a further improvement of the present invention, when continuously welding the joint seams on each side of the arm body in the same direction, each side joint seam is continuously welded in at least two sections.

[0012] Beneficial effects

[0013] Compared with the prior art, the advantages of the hook arm control welding deformation process method of the present invention are as follows:

[0014] 1. For the arm body of the hook arm, each panel part is first fixed, and after spot welding, the joint seam is continuously welded. The dimensional tolerances of the front arm and the vertical arm of the hook arm can be guaranteed within ±0.5 mm after welding, and there is no distortion, so the post-welding correction process can be omitted. Moreover, the welding efficiency is high, the manufacturing cost is low, mass production can be realized, and the product consistency is high.

[0015] 2. The bushings on both sides of the front arm adopt the method of welding through the shaft, ensuring the coaxiality of the bushings on both sides.

[0016] 3. After the front arm and the vertical arm are positioned and assembled, they are first spot welded, and the rigidity is improved by setting reinforcing ribs, and then the joint seam is continuously welded to ensure that the L shape remains vertical after welding.

[0017] 4. After the hook head and the hook arm foundation are positioned and assembled, they are first spot welded, and the rigidity is improved by setting reinforcing ribs, and then the joint seam is continuously welded. The deformation of the hook head after welding is small, and the correction process can be omitted. The central symmetry with the hook arm foundation can be controlled within 3 mm.

[0018] The present invention will become more apparent from the following description taken in conjunction with the accompanying drawings, which are used to explain embodiments of the present invention. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0020] Figure 1 Is a perspective view of the forearm;

[0021] Figure 2 Is a perspective view of the forearm fixed by the side plate positioning assembly and the pressing rod assembly of the welding fixture;

[0022] Figure 3 Is a perspective view of the forearm fixed by the upper pressing plate;

[0023] Figure 4 Is a welding sequence diagram of the forearm;

[0024] Figure 5 Is a perspective view of the vertical arm;

[0025] Figure 6 Is a perspective view of the vertical arm fixed by the side plate positioning assembly and the pressing rod assembly of the welding fixture;

[0026] Figure 7 Is a top view of the vertical arm fixed by the upper pressing plate;

[0027] Figure 8 Is a welding sequence diagram of the vertical arm;

[0028] Figure 9 Is a perspective view of the hook arm base positioned by the assembly fixture;

[0029] Figure 10 Is a schematic diagram of the hook arm base welding the first reinforcing rib;

[0030] Figure 11 Is one of the welding sequence diagrams of the hook arm base;

[0031] Figure 12 Is the second welding sequence diagram of the hook arm base;

[0032] Figure 13 Is a perspective view of the hook head;

[0033] Figure 14 Is a perspective view of the hook head and the hook arm base positioned by the assembly fixture;

[0034] Figure 15 Schematic diagram of the second reinforcing rib welded to the base of the hook head and the hook arm

[0035] Figure 16 Sequence diagram of continuous welding of the hook head and the hook arm base

[0036] Figure 17 Sequence diagram of welding the anti-collision components on the hook arm base

[0037] Figure 18 Stereogram of the hook arm Specific implementation mode

[0038] Now refer to the accompanying drawings to describe the embodiments of the present invention.

[0039] Embodiment

[0040] The specific implementation mode of the present invention is as follows Figures 1 to 5 As shown, a process method for controlling the welding deformation of a hook arm. The hook arm includes at least one arm body. The lower cover plate, left side plate, right side plate and upper cover plate of the arm body are clamped in the middle by a welding fixture to form a frame shape and fit together, and an inner cavity positioning part is placed in the inner cavity of the arm body. Spot welding is performed on the side splicing seams of the four parts, and then continuous welding is performed on each side splicing seam in the same direction to complete the welding process. When performing continuous welding on each side splicing seam of the arm body in the same direction, each side splicing seam is welded in at least two continuous sections.

[0041] In this embodiment, the arm body includes a front arm 1 and a vertical arm 2. The two are arranged perpendicular to each other. The hook arm also includes a hook head 7. Place the lower cover plate of the arm body on the bottom plate of the welding fixture. The left side plate and the right side plate of the arm body are arranged opposite to each other. One of their outer side walls is positioned by the side plate positioning component of the welding fixture, and the other outer side wall is pressed by the pressing rod component of the welding fixture. The upper cover plate is attached to the left side plate and the right side plate through the pressing plate screw component and the upper pressing plate of the welding fixture.

[0042] Specifically, the front arm 1 includes a first lower cover plate 12, a first left side plate 13, a first right side plate 14 and a first upper cover plate 11. Among them, the first lower cover plate 12 of the front arm 1 is placed on the first bottom plate 31 of the first welding fixture. The first left side plate 13 and the first right side plate 14 are arranged opposite to each other. The outer side wall of the first right side plate 14 is positioned by the first side plate positioning component 32 of the first welding fixture as the positioning reference. The outer side wall of the first left side plate 13 is pressed by the first pressing rod component 33 of the first welding fixture, as Figure 2As shown. The first upper cover plate 11 is attached to the first left side plate 13 and the first right side plate 14 by the first pressing plate screw assembly 37 and the first upper pressing plate 38 of the first welding fixture. The first pressing plate screw assembly 37 includes at least two small pressing plates and a screw-nut structure. The first upper pressing plate 38 is pressed directly above the first upper cover plate 11, and the first upper pressing plate 38 completely covers the first upper cover plate 11. The small pressing plates are arranged at intervals along the length direction of the first upper pressing plate 38 and are pressed above the first upper pressing plate 38. The screw of the first pressing plate screw assembly 37 passes through the small pressing plates and the first bottom plate 31 and presses the two towards the middle. A number of first inner cavity positioning members 34 are placed inside the forearm 1. The first inner cavity positioning members 34 are fitted to the inner wall of the forearm 1, and the positions of the first inner cavity positioning members 34 correspond to those of the first pressing rod assembly 33 and the first side plate positioning assembly 32. Spot welding is performed at the side splicing seams of the forearm 1, and then continuous welding is performed on each side splicing seam in the same direction. The welding sequence is as Figure 4 shown, thus completing the welding process of the forearm 1. After welding is completed, the first welding fixture is removed. In order to eliminate stress concentration and control deformation and distortion after welding, it is necessary to wait until it is completely cooled before removing all the pressing plates and bolts.

[0043] When clamping the forearm 1 with the first welding fixture, bushings 15 are placed on the through holes corresponding to the first left side plate 13 and the first right side plate 14 of the forearm 1. The positioning shaft passes through the bushings 15 on both sides at the same time. A positioning shaft sleeve 35 is also sleeved on the positioning shaft, and the two ends of the positioning shaft sleeve are respectively in contact with the inner end faces of the bushings 15 on both sides. The outer end faces of the bushings 15 on both sides are respectively clamped by the first pressing rod assembly 33 and the first lateral positioning member 32. Then the bushings 15 are welded to the first left side plate 13 and the first right side plate 14. After welding is completed, the positioning shaft is withdrawn and the positioning shaft sleeve 35 is removed.

[0044] The vertical arm 2 includes a second lower cover plate 22, a second left side plate 23, a second right side plate 24, and a second upper cover plate 21. Among them, the second lower cover plate 22 of the vertical arm 2 is placed on the second bottom plate 41 of the second welding fixture. The second left side plate 23 and the second right side plate 24 are arranged oppositely. The outer side wall of the second right side plate 24 is positioned by the second side plate positioning assembly 42 of the second welding fixture as the positioning reference. The outer side wall of the second left side plate 23 is pressed tightly by the second pressing rod assembly 43 of the second welding fixture, as Figure 6 shown. The second upper cover plate 21 is attached to the second left side plate 23 and the second right side plate 24 by the second pressing plate screw assembly 47 and the second upper pressing plate 48 of the second welding fixture. The second pressing plate screw assembly 47 includes at least two small pressing plates and a screw-nut structure. The second upper pressing plate 48 is pressed directly above the second upper cover plate 21, and the second upper pressing plate 48 completely covers the second upper cover plate 21. The small pressing plates are arranged at intervals along the length direction of the second upper pressing plate 48 and are pressed above the second upper pressing plate 48. The screw of the second pressing plate screw assembly 47 passes through the small pressing plates and the second bottom plate 41 and presses the two towards the middle.

[0045] A number of second inner cavity positioning members 44 are placed inside the vertical arm 2. Adjacent second inner cavity positioning members 44 are connected by a connecting rod 45. The second inner cavity positioning members 44 are in contact with the inner wall of the vertical arm 2, and the positions of the second inner cavity positioning members 44 correspond to those of the second pressing rod assembly 43 and the second side plate positioning assembly 42.

[0046] Spot welding is carried out at the side splicing seams of the vertical arm 2, and then continuous welding is carried out on each side splicing seam in the same direction. The welding sequence is as Figure 8 shown, thus completing the welding process of the vertical arm 2. After welding is completed, the second welding fixture is removed. In order to eliminate stress concentration and control deformation and distortion after welding, all the pressing plates and bolts can be disassembled only after it is completely cooled.

[0047] In the welding stage, a third reinforcing rib 9 is spot welded between the first left side plate 13 and the first right side plate 14 at the end of the front arm 1 for reinforcement; at the end of the vertical arm 2 for fitting with the front arm 1, a fourth reinforcing rib 10 is spot welded between the second left side plate 23 and the second right side plate 24 for reinforcement. Both the third reinforcing rib 9 and the fourth reinforcing rib 10 are removed after the continuous welding of the respective edges of the front arm 1 and the vertical arm 2 is completed and cooled.

[0048] After the welding process of the front arm 1 and the vertical arm 2 is completed, the hook arm foundation assembly step is carried out: the front arm 1 and the vertical arm 2 are placed on the assembly fixture for positioning and fitting to form the hook arm foundation, and then spot welding is carried out at the splicing seams of the two.

[0049] Specifically, when carrying out the hook arm foundation assembly step, the hook arm foundation is placed on the assembly bottom plate 51 of the assembly fixture, the outside of the hook arm foundation is positioned by the assembly positioning member 52, and the inside of the hook arm foundation is pressed by the assembly pressing rod assembly 53, as Figure 9 shown.

[0050] After spot welding is completed at the splicing joint of the front arm 1 and the vertical arm 2, the front arm 1 is placed on the third base 61, and the front arm 1 is pressed on the third base 61 by the third pressing plate screw assembly 62. The front arm 1 and the vertical arm 2 are temporarily connected by the first reinforcing rib 63, as Figure 10 shown. Then continuous welding is carried out at the splicing seams of the front arm 1 and the vertical arm 2, as Figure 11 、 12 shown. After welding is completed, the first reinforcing rib 63 is removed.

[0051] After the hook arm foundation assembly step is completed, the hook head welding step is carried out: the hook arm foundation and the hook head 7 are placed on the assembly fixture, the end of the vertical arm 2 is positioned and fitted with the hook head 7, and then spot welding is carried out at the splicing seams of the two, as Figure 14 shown.

[0052] Among them, a positioning hole 71 is provided on the hook head 7, and a hook head positioning component 54 is provided on the assembly jig. The hook head positioning component 54 includes a hook head backing plate and a positioning protrusion. The positioning protrusion of the hook head positioning component 54 corresponds to the positioning hole 71 of the hook head 7. A clamping groove is provided at the bottom of the hook head 7. A hook head positioning plate 72 is provided on one side of the clamping groove. The clamping groove of the hook head 7 is clamped and matched with one end of the vertical arm 2, and the hook head positioning plate 72 is attached to one side of the vertical arm 2. The thickness of the hook head plate is 40 mm, and the material is Q690. In order to ensure the welding quality, the hook head must be preheated before welding, and the preheating temperature is 200 - 250 °. In order to ensure that the symmetry between the hook head and the hook arm base is within 3 mm, the hook head cannot be welded into shape at one time during welding. It needs to be welded in two layers, and the front and back sides are welded alternately. For specific details, see the welding sequence of the final hook arm after welding the hook head Figure Seven . In order to eliminate stress concentration and control deformation and distortion after welding, the reinforcing ribs can be removed only after it has completely cooled down.

[0053] After spot welding is completed at the joint between the hook arm base and the hook head 7, the front arm 1 is placed on the third base 61, and the front arm 1 is pressed on the third base 61 through the third pressing plate screw assembly 62. The hook head 7 and the hook arm base are temporarily connected through the second reinforcing rib 8, and specifically, a welding method can be adopted. Then, continuous welding is performed at the joint between the vertical arm 2 and the hook head 7, and the welding sequence is as Figure 16 shown. After welding is completed, the second reinforcing rib 8 is removed, thereby completing the overall forming of the hook arm.

[0054] The present invention has been described in combination with the best embodiments, but the present invention is not limited to the disclosed embodiments above, and should cover various modifications and equivalent combinations made according to the essence of the present invention.

Claims

1. A hook arm control welding deformation process method, characterized in that, The hook arm includes at least one arm body; the lower cover plate, left side plate, right side plate, and upper cover plate of the arm body are clamped in the middle by a welding fixture to form a frame shape and fit together, and an inner cavity positioning member is placed in the inner cavity of the arm body; spot welding is performed at the side splicing seams of the four components, and then continuous welding is performed on each side splicing seam in the same direction to complete the welding process; the arm body includes a forearm (1) and a vertical arm (2); after the forearm (1) and the vertical arm (2) complete the welding process, the following hook arm foundation assembly steps are carried out: place the forearm (1) and the vertical arm (2) on an assembly fixture for positioning and fitting to form a hook arm foundation, and then perform spot welding at the splicing seam between the two; the forearm (1) and the vertical arm (2) are temporarily connected by a first reinforcing rib (63); then continuous welding is performed on the splicing seam between the forearm (1) and the vertical arm (2); after welding is completed, the first reinforcing rib (63) is removed; when carrying out the hook arm foundation assembly steps, the hook arm foundation is placed on the assembly bottom plate (51) of the assembly fixture, the outside of the hook arm foundation is positioned by an assembly positioning member (52), and the inside of the hook arm foundation is pressed by an assembly pressing rod assembly (53); after spot welding is completed at the splicing part between the forearm (1) and the vertical arm (2), place the forearm (1) on the third base (61), and press the forearm (1) on the third base (61) by a third pressing plate screw assembly (62); the forearm (1) and the vertical arm (2) are temporarily connected by a first reinforcing rib (63); then continuous welding is performed on the splicing seam between the forearm (1) and the vertical arm (2), and after welding is completed, the first reinforcing rib (63) is removed.

2. A hook arm control welding deformation process method according to claim 1, characterized in that Place the lower cover plate of the arm body on the bottom plate of the welding fixture; the left side plate and the right side plate of the arm body are arranged oppositely, one of their outer side walls is positioned by the side plate positioning component of the welding fixture, and the other outer side wall is pressed by the pressing rod component of the welding fixture; the upper cover plate is attached to the left side plate and the right side plate by the pressing plate screw assembly and the upper pressing plate of the welding fixture.

3. A hook arm control welding deformation process method according to claim 1, characterized in that, When carrying out the hook arm foundation assembly steps, the hook arm foundation is placed on the assembly bottom plate (51) of the assembly fixture, the outside of the hook arm foundation is positioned by an assembly positioning member (52), and the inside of the hook arm foundation is pressed by an assembly pressing rod assembly (53).

4. A hook arm control welding deformation process method according to claim 1, characterized in that After the hook arm foundation assembly steps are completed, the following hook head welding steps are carried out: place the hook arm foundation and the hook head (7) on an assembly fixture, position and fit one end of the vertical arm (2) with the hook head (7), and then perform spot welding at the splicing seam between the two; the hook head (7) and the hook arm foundation are temporarily connected by a second reinforcing rib (8); then continuous welding is performed on the splicing seam between the vertical arm (2) and the hook head (7); after welding is completed, the second reinforcing rib (8) is removed.

5. A hook arm control welding deformation process method according to claim 4, characterized in that The hook head (7) is provided with a positioning hole (71), and the assembly fixture is provided with a hook head positioning component (54). The hook head positioning component (54) includes a hook head backing plate and a positioning protrusion, and the positioning protrusion of the hook head positioning component (54) corresponds to the positioning hole (71) of the hook head (7).

6. A hook arm control welding deformation process method according to claim 1, characterized in that, When clamping the front arm (1) by the welding fixture, bushings (15) are placed on the through holes corresponding to the left and right side plates of the front arm (1). The positioning shaft passes through the bushings (15) on both sides at the same time. A positioning shaft sleeve (35) is also sleeved on the positioning shaft. The two ends of the positioning shaft sleeve are respectively in contact with the inner end faces of the bushings (15) on both sides. The outer end faces of the bushings (15) on both sides are respectively clamped by a first pressing rod assembly (33) and a first lateral positioning member (32). Then, the bushings (15) are welded to the left and right side plates together.

7. A hook arm control welding deformation process method according to claim 1, characterized in that, When continuously welding the splicing seams of each side of the arm body in the same direction, each side splicing seam is welded in at least two continuous segments.

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