JP5121653B2 - Welding apparatus and welding method - Google Patents

Description

  The present invention relates to a welding apparatus and a welding method for joining a knuckle bracket to an outer tube of a shock absorber.

  Conventionally, in the step of welding and joining the knuckle bracket of the shock absorber, the knuckle bracket is externally fitted to the outer tube, and the end surface of the external fitting portion of the knuckle bracket is arc welded in a circumferential shape and joined.

Patent Document 1 discloses an invention relating to an outer tube unit formed by welding and joining a knuckle bracket to an outer tube and a welding method thereof.
JP 2002-219570 A

  However, generally, in arc welding, distortion occurs during welding, and when cooled after welding, the bead contracts and deforms, resulting in variations in finished dimensions for each product. In addition, the finished dimensions of the shock absorbers vary depending on the processing accuracy of the single knuckle bracket, which is a sheet metal part, and quality control is difficult.

  In view of the above problems, an object of the present invention is to provide a welding apparatus that can suppress variations in finished dimensions of products.

  The present invention provides a knuckle comprising: a main body portion that is fitted on the outer periphery of an outer tube of a shock absorber; and a pair of attachment portions that are formed so as to protrude substantially parallel to the main body portion and have holes for attachment to a knuckle of a vehicle. A welding device for temporarily welding a bracket to the outer periphery of the outer tube, a state sandwiched between a plurality of spot welders for temporarily welding the knuckle bracket to the outer tube and the pair of attachment portions And a fixing jig for supporting the outer tube and the knuckle bracket and defining a distance between the pair of mounting parts, and inserting a tip into a hole of the mounting part to fix the mounting part to the fixing jig. A positioning pin that determines the position of the knuckle bracket with respect to the outer tube, and inserts the positioning pin into the hole. The position of the hole with respect to the outer tube is determined by pressing the pair of mounting portions against the fixing jig, and the distance between the pair of mounting portions is defined by the width of the fixing jig. The outer tube and the end of the knuckle bracket are spot welded by the plurality of spot welders.

  According to the present invention, the relative position between the outer tube and the knuckle bracket can be fixed by preliminarily welding the knuckle bracket to the outer tube by determining the position of the hole of the knuckle bracket relative to the outer tube and the interval between the mounting portions. Therefore, deformation caused by subsequent main welding and deformation due to bead shrinkage can be minimized.

  Therefore, it is possible to obtain a welding apparatus that can suppress variations in the finished dimensions of the product.

  Hereinafter, a welding apparatus 100 according to an embodiment of the present invention will be described with reference to the drawings.

  1 is a front view of a welding apparatus 100 according to an embodiment of the present invention, FIG. 2 is a right side view of FIG. 1, FIG. 3 is a plan view of FIG. It is a two-view figure of the container 1, (a) is a front view, (b) is a right view. In FIG. 1, the spot welder 50 is not displayed in order to describe the positioning device 200 in detail.

  As shown in FIG. 4, the shock absorber 1 which is a product to be welded by the welding apparatus 100 includes a cylindrical outer tube 2 forming a cylinder of the shock absorber 1 and a knuckle bracket attached to a knuckle (not shown) for steering a wheel. 3.

  A piston and a piston rod (not shown) are inserted into the cylindrical outer tube 2 in the axial direction. A fluid such as gas or oil is sealed inside the cylinder.

  The knuckle bracket 3 includes a main body portion 3e fitted to the outer periphery of the outer tube 2 and two attachment portions 3a for attachment to the knuckle of the vehicle. The main body 3e is fitted in the outer peripheral direction of the outer tube 2 and is fixed to the outer tube 2 by welding. Both ends of the knuckle bracket 3 in the outer peripheral direction rise from the outer tube 2 and protrude, and a pair of attachment portions 3a parallel to each other are formed. Each of the pair of attachment portions 3a is provided with two holes 3b. The attachment portion 3a is fastened to the knuckle of the vehicle by a bolt as a fastener fitted into the hole 3b.

  The shock absorber 1 attached to the vehicle keeps the width α of the pair of attachment portions 3a that are the portions fastened to the knuckle and the size of the position β of the fastening hole 3b with respect to the central axis of the outer tube 2 within a specified range. There is a need. These dimensions are dimensions that must be within a specified range in order to mount the shock absorber 1 on the vehicle, that is, dimensional accuracy is required.

  The welding device 100 is a device for temporarily welding and fixing the knuckle bracket 3 to the outer tube 2 of the shock absorber 1.

  The welding apparatus 100 includes a positioning device 200 that determines the position of the knuckle bracket 3 with respect to the central axis of the outer tube 2, and four spot welders 50 that temporarily weld the outer tube 2 and the knuckle bracket 3. The welding apparatus 100 is attached on the gantry 60.

  The positioning device 200 supports the outer tube 2 of the shock absorber 1 at the upper part, and is fixed to the fixing jig 30 that is sandwiched between the two attachment portions 3a of the knuckle bracket 3 and the four holes 3b of the knuckle bracket 3, respectively. And a pin insertion unit 10 for inserting the positioning pin 20 from both sides of the knuckle bracket 3 into the hole 3b.

  As shown in FIG. 1, the fixing jig 30 is provided on the uppermost portion of the positioning device 200 in the welding device 100, and supports the outer tube 2 and the knuckle bracket 3 of the shock absorber 1 when in use. At the top of the fixing jig 30, an arc-shaped recess 30 b that is parallel to the outer tube 2 and that corresponds to the outer peripheral surface of the outer tube 2 is formed. On both side surfaces in the axial direction of the shock absorber 1 of the fixing jig 30, a step 30 a having the same thickness as the knuckle bracket 3 and corresponding to the mounting portion 3 a of the knuckle bracket 3 is formed.

  The fixing jig 30 is attached to the upper part of the base 40 fixed on the gantry 60 via a slider 41 that slides parallel to the longitudinal direction of the shock absorber 1. That is, the fixing jig 30 can be moved relative to the gantry 60 and can be translated in the longitudinal direction of the shock absorber 1. The base 40 that supports the fixing jig 30 has a block shape, and a lower end is fixed on the gantry 60.

  The shock absorber 1 in a state where the main body portion 3e of the knuckle bracket 3 is externally fitted to the outer tube 2 is placed on the fixing jig 30 when the welding apparatus 100 is used. That is, the fixing jig 30 supports the shock absorber 1 in a state where the outer peripheral surface of the outer tube 2 is in contact with the upper concave portion 30b and the mounting portion 3a of the knuckle bracket 3 sandwiches the step 30a.

  The width of the fixing jig 30 at the portion sandwiched between the attachment portions 3 a is formed larger than the product dimension α between the pair of attachment portions 3 a of the knuckle bracket 3. This is because the space between the attachment portions 3a is reduced by shrinkage after welding. Here, it is conceivable that the attachment portion 3 a strongly holds the fixing jig 30 after welding, and the shock absorber 1 cannot be detached from the fixing jig 30. Therefore, inside the fixing jig 30, a knockout pin (not shown) for removing the placed outer tube 2 is provided. The knockout pin is provided vertically in the fixing jig 30 and projects the outer peripheral surface of the outer tube 2 upward. The knockout pin is driven by a pneumatic cylinder (not shown).

  The positioning pin 20 is a cylindrical pin whose tip is inserted into the hole 3 b of the knuckle bracket 3 supported on the fixing jig 30. The positioning pin 20 is provided such that its axial direction is perpendicular to the fixing jig 30 and parallel to the gantry 60. The number of positioning pins 20 corresponding to the holes 3b of the knuckle bracket 3 is provided.

  The positioning pin 20 moves in the axial direction when the welding apparatus 100 is used, and is inserted into the hole 3 b of the knuckle bracket 3. The diameter of the positioning pin 20 is larger than that of the hole 3b, and a chamfered portion 20a is formed at the tip thereof. The diameter of the tip of the chamfered portion 20a of the positioning pin 20 is formed smaller than that of the hole 3b. That is, the positioning pin 20 is easily inserted into the hole 3b by forming the chamfered portion 20a. The positioning pin 20 fits into the hole 3b in the middle of the chamfered portion 20a. After the positioning pin 20 is fitted in the hole 3b, even if the positioning pin 20 is moved, it is not inserted into the hole 3b any more, and the mounting portion 3a is pressed while being fitted in the hole 3b.

  As shown in FIG. 4, the positioning pin 20 determines the position β of the knuckle bracket 3 with respect to the central axis of the outer tube 2 with reference to the position of the hole 3 b. In the present embodiment, a total of four positioning pins, two on each side, are provided facing the mounting portion 3a of the knuckle bracket 3.

  The pin insertion unit 10 holds a rectangular frame 15 that holds one of the two positioning pins 20 inside, and the other two positioning pins 20, and is relatively inside the frame 15 relative to the frame 15. A moving plate 14 that translates.

  The rectangular frame 15 includes fixing plates 12 and 13 provided in parallel to the central axis of the shock absorber 1 and perpendicular to the gantry 60, and two end plates 11 that fix both sides thereof. The fixed plates 12 and 13 and the two end plates 11 form a quadrangle when viewed in plan as shown in FIG. Inside the frame 15, a moving plate 14 that moves relative to the fixed plates 12 and 13 is provided in parallel with the fixed plates 12 and 13.

  The frame 15 formed by the fixed plates 12 and 13 and the end plate 11 of the pin insertion unit 10 and the moving plate 14 are perpendicular to the central axis of the shock absorber 1 on the frame 60 via independent slider mechanisms (not shown). And is supported so as to be movable in the horizontal direction.

  Two positioning pins 20 are attached to the opposing surfaces of the movable plate 14 and the fixed plate 12 constituting one side of the quadrangular frame 15, respectively. When the welding apparatus 100 is used, the positioning pin 20 provided opposite to the knuckle bracket 3 is moved by the frame 15 and the moving plate 14 relatively moving in a direction in which the mounting surfaces of the positioning pins 20 approach each other. It moves and presses so that it may insert in the hole 3b.

  The fixed plate 12 is a rectangular and thick block-like plate provided perpendicular to the gantry 60 and parallel to the central axis of the shock absorber 1. The fixing plate 12 holds one of the two positioning pins 20 in accordance with the height corresponding to the hole 3 b of the knuckle bracket 3 of the shock absorber 1 held on the fixing jig 30. A pneumatic cylinder 18 that displaces the position of the fixing plate 12 with respect to the base 40 that supports the fixing jig 30 is attached to the outer side surface of the fixing plate 12 at right angles to the shock absorber 1.

  The fixed plate 13 is a rectangular and thick block-like plate that is parallel to the fixed plate 12 and provided on the opposite side across the shock absorber 1. A pneumatic cylinder 17 for displacing the position of the fixing plate 13 with respect to the base 40 that supports the fixing jig 30 is attached to the outer side surface of the fixing plate 13 so as to be orthogonal to the shock absorber 1. The fixing plate 13 is further provided with a hydraulic cylinder 19 for pressing the spacing between the mounting portions 3a of the knuckle bracket 3 until the predetermined spacing is reached after the positioning pin 20 is inserted into the hole 3b of the knuckle bracket 3. . The pneumatic cylinder 17 and the hydraulic cylinder 19 are provided side by side so that the hydraulic cylinder 19 is disposed above the pneumatic cylinder 17.

  A two-dot chain line in FIG. 1 is an end plate 11 on the near side and the opposite side of the solid line part, and is shown by a two-dot chain line in order to describe the solid line part in detail.

  The two end plates 11 are substantially rectangular plates provided perpendicular to the gantry 60 and are provided in contact with both end surfaces of the two fixing plates 12 and 13 in the longitudinal direction. Secure with. As a result, the fixed plates 12 and 13 and the two end plates 11 form a rectangular frame 15 that is a skeleton of the pin insertion unit 10. A notch 11 a for the shock absorber 1 and the spot welder 50 is formed on the upper portion of the end plate 11.

  The movable plate 14 is a rectangular and thick block-like plate provided in parallel with the fixed plates 12 and 13 and inside the rectangular frame 15 formed by the fixed plates 12 and 13 and the end plate 11 so as to be movable in parallel. It is. The moving plate 14 holds the other two positioning pins 20 in accordance with the height corresponding to the hole 3 b of the knuckle bracket 3 of the shock absorber 1 held on the fixing jig 30.

  The moving plate 14 has a rod fixing portion 14e for fixing the tip 17b of the rod 17a of the pneumatic cylinder 17 to the fixed plate 13 side facing, and a pressure receiving plate 14c that receives a pressing force from a hydraulic cylinder 19 as a pressure cylinder. Is provided.

  On the side surfaces of the fixed plate 12 and the moving plate 14 on the shock absorber 1 side, recesses 12c and 14d are formed near both ends in the longitudinal direction, respectively. Sliders 12b and 14b for adjusting the height of the positioning pin 20 are fitted into the recesses 12c and 14d. Pin bases 12 a and 14 a are slidably attached to the fixed plate 12 and the movable plate 14 on the sliders 12 b and 14 b. Two positioning pins 20 are attached to each of the pin bases 12 a and 14 a so as to face the shock absorber 1.

  The pin bases 12a and 14a whose heights are adjusted by the sliders 12b and 14b are fixed at the positions by operating the levers 12f and 14f. Therefore, the height of the positioning pin 20 does not change after the heights of the pin bases 12a and 14a are fixed.

  The pneumatic cylinder 17 is attached to a substantially central portion in the longitudinal direction of the fixed plate 13 and to an outer side surface of the fixed plate 13. The pneumatic cylinder 17 includes a rod 17a that enters and exits by air pressure. The rod 17a penetrates the fixed plate 13, and the tip 17b is formed to have a larger diameter than the rod 17a and is fixed to a rod fixing portion 14e provided on the moving plate 14. The rod fixing portion 14e restrains both the front and back surfaces of the tip 17b of the rod 17a. Therefore, the moving plate 14 can follow both the movement of the pneumatic cylinder 17 in and out.

  The pneumatic cylinder 18 is attached to a substantially central portion in the longitudinal direction of the fixed plate 12 and an outer end surface of the fixed plate 12. The pneumatic cylinder 18 includes a rod 18a that enters and exits by air pressure. The rod 18 a penetrates the fixing plate 12, and the tip 18 b is formed with a larger diameter than the rod 18 a and is fixed to a rod fixing portion 40 a provided on the base 40. A rod fixing portion 40 a for fixing the tip 18 b of the rod 18 a of the pneumatic cylinder 18 is provided on the side surface of the base 40 on the fixing plate 12 side. The rod fixing portion 40a restrains both the front and back surfaces of the tip 18b of the rod 18a. Therefore, the fixed plate 12 can follow both the movement of the pneumatic cylinder 18 in and out.

  The pneumatic cylinders 17 and 18 are provided for inserting the positioning pins 20 into the holes 3 b of the knuckle bracket 3. The pneumatic cylinders 17 and 18 are based on the center of the shock absorber 1 fixed on the fixing jig 30, and the fixed plate 12 to which the positioning pin 20 is fixed and the moving plate 14 are directed toward the center of the shock absorber 1. Move. At this time, the pneumatic cylinder 17 operates to project the rod, and the pneumatic cylinder 18 operates to contract the rod.

  Here, the fixed plate 13 that forms a rectangular frame 15 integrally with the fixed plate 12 and the end plate 11 is moved in a direction away from the shock absorber 1 together with the frame 15 by the stroke of the pneumatic cylinder 18. This is because the tip 18b of the rod 18a is fixed by the rod fixing portion 40a. At this time, the two positioning pins attached to the fixed plate 12 approach the shock absorber 1, but the two positioning pins 20 attached to the moving plate 14 are separated from the shock absorber 1. Therefore, in order to coordinate the movement of the four positioning pins 20 attached to the fixed plate 12 and the moving plate 14 toward the center, the stroke of the pneumatic cylinder 17 cancels the stroke of the pneumatic cylinder 18 and further moves. A stroke for moving the plate 14 closer to the shock absorber 1 is necessary. That is, the stroke of the pneumatic cylinder 17 needs to be twice the stroke of the pneumatic cylinder 18.

  The hydraulic cylinder 19 is a cylinder that is mounted on the fixed plate 13 side by side above the pneumatic cylinder 17 and allows the rod 19a to enter and exit hydraulically. The rod 19a is provided through the fixed plate 13, and its tip 19b presses the pressure receiving plate 14c provided on the moving plate. Since the tip 19b of the rod 19a only abuts on the moving plate 14 and is not restrained by the moving plate 14, the hydraulic cylinder 19 performs only the operation of pressing the moving plate 14.

  The pneumatic cylinders 17 and 18 and the hydraulic cylinder 19 are connected to a pneumatic circuit and a hydraulic circuit (not shown), respectively, and operate by switching valves. The valve may be an electromagnetic valve or a manual valve, and its type is not limited.

  Below, the spot welder 50 is demonstrated, referring FIG. 2, FIG. In FIG. 2, the pin insertion unit 10 is not displayed in order to explain the position of the spot welder 50. FIG. 3 shows a state in which the shock absorber 1 is not mounted in order to explain the welding apparatus 100 in detail.

  Four spot welders 50 are provided facing the shock absorber 1 fixed on the positioning device 200. These spot welders 50 correspond to welders.

  The respective tip portions of the four spot welders 50 are directed to the end portions 3c and 3d where the knuckle bracket 3 is attached to the outer tube 2 of the shock absorber 1, and the respective positions are spot welded so that the knuckle bracket 3 Is temporarily welded to the outer tube 2 and fixed. Specifically, the knuckle bracket 3 is temporarily welded near the boundary where the knuckle bracket 3 changes from the main body portion 3e fitted on the outer periphery of the outer tube 2 to the portion that rises to form the attachment portion 3a. This is because the positioning pin 20 presses the mounting portion 3 a by the hydraulic cylinder 19, the distance between the two mounting portions 3 a is set to the width of the fixing jig 30, and the hole 3 b of the knuckle bracket 3 with respect to the central axis of the outer tube 2. This is because temporary welding is performed with the position held at a specified position.

  Of the four spot welders 50, the two spot welders 50 </ b> A and 50 </ b> B are provided facing one end 3 d side of the knuckle bracket 3. The spot welders 50A and 50B are attached to the left and right sides of the outer tube 2 so as not to interfere with the outer tube 2 to be inserted, with the front end portion thereof being obliquely upward from where the knuckle bracket 3 is located. The spot welders 50 </ b> A and 50 </ b> B are each mounted on a gantry 60 via a pneumatic cylinder 51 so as to be movable in the vertical direction by a slider 52. The rod 51a of the pneumatic cylinder 51 is attached to the spot welders 50A and 50B, and the vertical positions of the spot welders 50A and 50B are translated by the operation of the pneumatic cylinder 51 moving in and out of the rod 51a.

  The remaining two spot welders 50C and 50D are provided opposite to the other end 3c side of the knuckle bracket 3. The spot welders 50 </ b> C and 50 </ b> D are provided in parallel with the shock absorber 1. The spot welders 50C and 50D are provided to be movable in the axial direction of the shock absorber 1 by a slider and a pneumatic cylinder (not shown), respectively.

  In the present embodiment, four spot welders 50 are provided. However, the number of spot welders 50 is not limited to this number, as long as the knuckle bracket 3 can be welded to the outer tube 2. For example, a mode in which one spot welder 50 is moved and a plurality of locations are temporarily welded and fixed may be used.

  Below, the operation | movement of the welding apparatus 100 which concerns on embodiment of this invention, and the welding method using the welding apparatus 100 are demonstrated.

  On the fixing jig 30, the shock absorber 1 in a state where only the knuckle bracket 3 is externally fitted to the outer tube 2 but not yet fixed is placed. At this time, the outer periphery of the outer tube 2 is brought into contact with the fixing jig 30, and the end of the mounting portion 3 a is brought into contact with the step 30 a so that the fixing jig 30 is sandwiched by the mounting portion 3 a of the knuckle bracket 3. Let This process corresponds to a support process. This supporting step may be performed manually or automatically using a robot or the like. When the support process is completed, the process proceeds to the positioning process.

The pneumatic cylinders 17 and 18 are operated by switching valves (not shown), and the moving plate 14 holding the two positioning pins 20 and the frame 15 having the fixed plate 12 are moved toward the center of the shock absorber 1. . The pneumatic cylinder 17 is driven in a direction to project the rod 17a, and the pneumatic cylinder 18 is driven in a direction to contract the rod 18a. When the moving plate 14 and the rectangular frame 15 having the fixed plate 12 move, the four positioning pins 20 move in the axial direction, and the tips of the positioning pins 20 are inserted into the holes 3b of the knuckle bracket 3, respectively . Therefore, while the chamfered portion 20a of the positioning pin 20 is inserted into the hole 3b, the position of the positioning pin 20 in the height direction and the position of the positioning pin 20 in the axial direction of the shock absorber 1 are finely adjusted. Is inserted into the center of the hole 3b.

  Thereafter, when the hydraulic cylinder 19 is operated by switching a valve (not shown), the rod 19a protrudes and the moving plate 14 is further pressed against the shock absorber 1. At this time, the positioning pin 20 is further pushed into the hole 3 b and the attachment portion 3 a of the knuckle bracket 3 is pushed against the fixing jig 30. As a result, the position of the hole 3b of the knuckle bracket 3 with respect to the central axis of the outer tube 2 is determined to be a predetermined position β, and the interval of the attachment portions 3a of the knuckle bracket 3 is determined to be a predetermined interval α. Further, by adjusting the hydraulic pressure of the hydraulic cylinder 19, it can be adjusted to a desired pressing force.

  The positioning pins 20 are inserted into the holes 3b by the pneumatic cylinders 17 and 18 and the hydraulic cylinder 19, and the position of the hole 3b of the mounting portion 3a with respect to the central axis of the outer tube 2 is determined as a specified position β. The step of determining the interval 3a to the prescribed width α corresponds to the positioning step.

  Here, the diameter of the positioning pin 20 is larger than that of the hole 3b, and the middle of the chamfered portion 20a formed at the tip thereof is formed to be equal to the hole 3b. Therefore, after the chamfered portion 20a is fitted in the hole 3b, the positioning pin 20 is not inserted into the hole 3b any more even if the hydraulic cylinder 19 protrudes from the rod 19a, and the fitting portion 3a is pressed while being fitted in the hole 3b. To do. Therefore, only a small portion of the tip of the positioning pin 20 is inserted into the hole 3b, and the tip of the inserted positioning pin 20 interferes with the fixing jig 30 with which the mounting portion 3a of the knuckle bracket 3 abuts. Absent. When the positioning process is completed, the process proceeds to a temporary welding process.

  When the rod 51a of the pneumatic cylinder 51 is projected, the spot welders 50A and 50B are raised to a position where one end 3d of the knuckle bracket 3 can be welded. When a rod of a pneumatic cylinder (not shown) is projected, the spot welders 50C and 50D move horizontally to the position at which the other end 3c of the knuckle bracket 3 can be welded.

  In the spot welder 50, the knuckle bracket 3 facing each tip is fixed by spot welding a part of the end portion attached to the outer tube 2. Specifically, the base end portion of the rising portion is spot-welded to form the attachment portion 3a from the main body portion 3e of the knuckle bracket 3 fitted to the outer periphery of the outer tube 2. Thus, in a state where the relative position between the hole 3b of the attachment portion 3a of the knuckle bracket 3 and the outer tube 2 is kept at a prescribed distance β, and the interval between the two attachment portions 3a is kept at a prescribed interval α, The knuckle bracket 3 is temporarily welded to the outer tube 2 and fixed. This process corresponds to a temporary welding process.

  When the provisional welding process is completed, the spot welding machine 50 moves to a position where the rod 51a of the pneumatic cylinder 51 connected thereto is contracted and does not interfere when the shock absorber 1 is removed from the fixing jig 30.

  The hydraulic cylinder 19 operates by switching a valve (not shown), and the rod 19a moves in a contracting direction. As a result, the tip 19 b of the rod 19 a of the hydraulic cylinder 19 is separated from the moving plate 14. At this time, since the tip 19b of the rod 19a is not restrained by the moving plate 14, the moving plate 14 is not moved depending on the contracting operation of the rod 19a, and the tip 19b is only separated from the moving plate 14.

  Thereafter, the pneumatic cylinder 17 operates in a direction in which the rod 17a contracts, and the pneumatic cylinder 18 operates in a direction in which the rod 18a protrudes. The fixed plate 12 and the moving plate 14 are separated from the shock absorber 1, and the positioning pin 20 is detached from the hole 3 b of the knuckle bracket 3. Since the tips 17b and 18b of the rods 17a and 18a are fixed to the rod fixing part 40a of the base 40 and the rod fixing part 14e of the moving plate 14, respectively, the pneumatic cylinders 17 and 18 drive the fixing plate 12 and The moving plate 14 can be separated from the shock absorber 1.

  When the positioning pin 20 is sufficiently separated from the shock absorber 1, a knockout pin (not shown) provided inside the fixing jig 30 and protruding vertically to the upper part of the fixing jig 30 is protruded by a pneumatic cylinder (not shown), The shock absorber 1 in which the knuckle bracket 3 is temporarily welded to the outer tube 2 is pushed upward from the fixing jig 30 and removed. Thus, the temporary welding of the knuckle bracket 3 and the outer tube 2 of the shock absorber 1 is completed.

  The removed shock absorber 1 is transferred to the next main welding process (not shown), and is respectively arc welded along both end portions 3c and 3d of the knuckle bracket 3 which is temporarily welded and fixed to the outer tube 2. Circumferential arc welding. As a result, the entire peripheries of both end portions 3c and 3d of the knuckle bracket 3 are welded to and joined to the outer tube 2.

  At this time, the knuckle bracket 3 is temporarily welded to the outer tube 2, and the interval α between the attachment portions 3 a and the position β of the hole 3 b of the knuckle bracket 3 with respect to the central axis of the outer tube 2 are determined as prescribed. It is firmly fixed. Therefore, even if the main welding is performed, the shaft is prevented from being displaced or decentered by the weight of the outer tube 2. Specifically, in the process of first welding one end portion 3c first, since the opposite end portion 3d is temporarily welded, the outer tube 2 and the knuckle bracket 3 are not welded even if the end portion 3c is finally welded. The relative position β with respect to the hole 3b and the distance α between the mounting portions 3a are suppressed from changing. Next, in the step of main welding the other end 3d, since the end 3c has already been fully welded, the relative position β and the attachment between the outer tube 2 and the hole 3b of the knuckle bracket 3 even if the end 3d is fully welded. The change in the distance α between the parts 3a is suppressed. Therefore, the distortion which generate | occur | produces at the time of this welding and the deformation | transformation by shrinkage | contraction of the formed bead are suppressed. The same effect can be obtained even if the end 3d is finally welded first and then the end 3c is finally welded.

  According to the above embodiment, the following effects are obtained.

  The knuckle bracket 3 is temporarily welded to the outer tube 2 with the position β of the hole 3b of the knuckle bracket 3 relative to the central axis of the outer tube 2 and the interval between the mounting portions 3a being determined as specified, whereby the knuckle bracket 3 is Subsequent main welding can be performed in a state where the tube 2 is fixed to a prescribed position. Therefore, dimensional variations due to bead shrinkage and the like that occur during main welding can be minimized.

  Therefore, it is possible to obtain the welding apparatus 100 that can suppress variations in the finished dimensions of the product.

  In the conventional method, the finished size of the shock absorber 1 varies depending on the processing accuracy of the single knuckle bracket 3 that is a sheet metal part. However, according to the present embodiment, temporary welding is performed with the positioning pin 20 and the fixing jig 30 fixing the position β of the hole 3b of the knuckle bracket 3 and the interval α between the mounting portions 3a. For this reason, regardless of the processing accuracy of the knuckle bracket 3, the finished dimensions of the shock absorber 1 can be kept within a certain allowable range. That is, it is possible to correct variations in machining accuracy of the knuckle bracket 3 alone.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  The welding apparatus and the welding method according to the present invention can be used for a process of welding a knuckle bracket of a shock absorber to an outer tube and other similar processes.

It is a front view of the welding apparatus which concerns on embodiment of this invention. It is a right view in FIG. FIG. 3 is a plan view in FIG. 2. It is a two-view figure of the shock absorber which is a product welded with a welding apparatus.

Explanation of symbols

100 welding device 200 positioning device 1 shock absorber 2 outer tube 3 knuckle bracket 3a mounting portion 3b hole 3c end portion 3d end portion 10 pin insertion unit 14 moving plate 15 frame 17 pneumatic cylinder 18 pneumatic cylinder 19 hydraulic cylinder 20 positioning pin 30 Fixing jig 50 Spot welder 51 Pneumatic cylinder

Claims (6)

A main body portion that is inserted into the outer periphery of the outer tube of the shock absorber;
A pair of attachment portions that are formed to project substantially parallel from the main body portion and have holes for fitting fasteners to be attached to the knuckle of the vehicle;
A knuckle bracket comprising a welding device for temporary welding to the outer periphery of the outer tube,
A plurality of welding machines for temporarily welding the knuckle bracket to the outer tube;
A fixing jig for supporting the outer tube and the knuckle bracket in a state sandwiched between a pair of the mounting portions, and defining a distance between the pair of mounting portions,
A positioning pin that inserts a tip into the hole of the mounting portion and presses the mounting portion against the fixing jig to determine the position of the knuckle bracket with respect to the outer tube;
With
By positioning the positioning pins into the holes and pressing the pair of mounting portions against the fixing jig, the positions of the holes with respect to the outer tube are determined and the interval between the pair of mounting portions is fixed. A welding apparatus, wherein the outer tube and the end of the knuckle bracket are temporarily welded by the plurality of welders in a state defined by a width of a jig.   The welding apparatus according to claim 1, wherein the temporary welding is performed on one end and the other end of the knuckle bracket in the axial direction of the outer tube.   The temporary welding is performed at a total of four locations: two locations at the base end of the mounting portion at the one end and two locations at the base end of the mounting portion at the other end. The welding apparatus according to claim 2. A rectangular frame that holds one positioning pin inside the one side and translates in the axial direction of the positioning pin;
A movable plate that is provided inside the rectangular frame, holds the other positioning pin opposite to the one positioning pin, and moves parallel to the axial direction of the positioning pin;
Further comprising
4. The welding apparatus according to claim 1, wherein the positioning pin is inserted into the hole by the relative movement of the frame and the moving plate. 5.   The welding apparatus according to claim 4, wherein the moving plate is moved by a pressure cylinder. A body portion that is fitted around the outer tube of the shock absorber;
A pair of attachment portions that are formed to project substantially parallel from the main body portion and have holes for fitting fasteners to be attached to the knuckle of the vehicle;
A knuckle bracket comprising: a welding method for temporarily welding to the outer periphery of the outer tube,
A supporting jig for supporting the knuckle bracket and the outer tube with a fixing jig provided so as to be sandwiched between a pair of the mounting portions;
By inserting the tip of the positioning pin into the hole and pressing the pair of mounting portions against the fixing jig, the position of the hole with respect to the outer tube is determined, and the distance between the pair of mounting portions is set. A positioning step defined by the width of the fixing jig;
A temporary welding step of temporarily welding the outer tube and the end of the knuckle bracket;
A welding method comprising:

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