A coupling welding fixture

Abstract

This invention relates to the field of welding technology, and more particularly to a welding fixture for couplings. The technical problem of this invention is that current adjustments to the clamps reduce the efficiency of fixing the coupling and spline sleeve, thereby reducing the efficiency of welding the coupling and spline sleeve. Manual fixing is prone to misalignment or deviation, easily leading to inaccurate welding. During clamping, the bottom of the spline sleeve and the top of the coupling may not fit properly, affecting the welding quality. A coupling welding fixture includes a base, a rotating rod, and a chassis; the rotating rod is rotatably mounted on the base, and the chassis is mounted on the top of the rotating rod. This invention uses three initial straightening frames moving towards each other to straighten and fix the coupling body, and three swing frames moving towards each other to straighten and fix the spline sleeve. This allows for the straightening and fixing of coupling bodies and spline sleeves of different specifications, improving the applicability of this fixture.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to a welding fixture for couplings. Background Technology

[0002] When welding spline sleeves onto couplings, the spline sleeve is typically placed on the coupling, and then a clamp is used to secure both the coupling and the spline sleeve. However, due to the varying specifications of couplings and spline sleeves, manual adjustment of the clamp is often required for different sizes of couplings and spline sleeves. This reduces the efficiency of securing the coupling and spline sleeve, thus reducing the overall welding efficiency. Furthermore, manual clamping for different sizes of couplings and spline sleeves can easily lead to misalignment or misalignment, causing relative movement between the coupling and spline sleeve during welding. This can result in inaccurate welding. Currently, during the clamping process, the bottom of the spline sleeve may not fit snugly against the top of the coupling, affecting the welding quality. Summary of the Invention

[0003] In view of this, the present invention provides a coupling welding fixture that can stably fix couplings and spline sleeves of various specifications, and can also straighten the couplings and spline sleeves to prevent relative movement between them during the welding process, thereby improving fixing efficiency and subsequent welding accuracy. It can also press the spline sleeve so that the bottom of the spline sleeve can be tightly attached to the top of the coupling, further improving the welding quality of the spline sleeve and the coupling.

[0004] The technical implementation scheme of the present invention is as follows: a coupling welding fixture includes a base, a rotating rod, a chassis, a cover sleeve, a preliminary straightening mechanism, a locking mechanism, and a secondary straightening mechanism. The rotating rod is rotatably mounted on the base, and the chassis is mounted on the top of the rotating rod. The cover sleeve is mounted on the chassis, and the coupling body is placed on the cover sleeve. The spline sleeve to be welded is placed on the coupling body. The chassis and the cover sleeve are provided with a preliminary straightening mechanism for straightening the coupling body. The cover sleeve and the preliminary straightening mechanism are provided with a locking mechanism for locking the preliminary straightening mechanism. The cover sleeve is provided with a secondary straightening mechanism for straightening the spline sleeve.

[0005] More preferably, the preliminary correction mechanism includes guide rails, electric sliders, lower magnets, preliminary correction frames, and upper magnets. Several guide rails are evenly spaced on the chassis, and each guide rail is equipped with an electric slider that slides along it. Each electric slider is equipped with a lower magnet. Several preliminary correction frames are evenly spaced on the cover cylinder, and each preliminary correction frame is equipped with an upper magnet at its lower part. The several upper magnets are located inside the cover cylinder. The magnetic poles of the lower magnets and upper magnets are opposite on the side that is close to each other, and the lower magnets and upper magnets attract each other.

[0006] More preferably, the locking mechanism includes guide sleeves, threaded locking rods, spur gears, and drive racks. Several guide sleeves are evenly spaced at the top of the cover cylinder. The lower parts of several primary straightening frames are slidably connected to several guide sleeves. Each guide sleeve has a threaded locking rod threadedly connected to both sides. The sides of two threaded locking rods that are close to each other are located on both sides of the primary straightening frame. A spur gear is installed on the sides of two threaded locking rods that are far apart from each other. The two spur gears on each guide sleeve form a group. A drive rack is installed on both sides of each electric slider. Each drive rack is located diagonally below each spur gear.

[0007] More preferably, the secondary correction mechanism includes a hollow slide, a return spring, a positioning rod, a double rack frame, a slot frame, a sliding frame, a swing frame, swing teeth, and a vertical rack frame. The cover cylinder has several evenly spaced slots, each slot containing a sliding hollow slide. A return spring connects each hollow slide to each slot. A positioning rod is installed on the side of each slot near the return spring, with the other end of each positioning rod contacting one side of each hollow slide. Several double rack frames are evenly spaced and slidably arranged at the top of the cover cylinder, each rack frame connecting to two columns in each group. The gears mesh, and a slotted frame is installed on one side of several double rack frames that are close to each other. Each slotted frame has a drive slot, and each drive slot consists of an inclined part and a horizontal part. A sliding frame is slidably installed inside each hollow slide, and the bottom of each sliding frame is slidably connected to the drive slot in each slotted frame. A swing frame is rotatably installed on the top of each hollow slide, and a swing tooth is installed on each side of each swing frame. The two swing teeth on each swing frame form a group. A vertical rack frame is installed on the top of each slide frame, and each vertical rack frame meshes with the two swing teeth in each group.

[0008] More preferably, it also includes handles, with several handles evenly spaced on the chassis.

[0009] More preferably, it also includes a pressing mechanism, which is mounted on the swing frame. The pressing mechanism is used to press the spline sleeve. The pressing mechanism includes a pressing frame and a compression spring. Each swing frame is slidably provided with a pressing frame, and each pressing frame is connected to each swing frame with a compression spring.

[0010] More preferably, it also includes a limiting mechanism, which is set on the base and chassis. The limiting mechanism is used to limit the chassis and cover cylinder. The limiting mechanism includes a positioning frame, a positioning spring and an internal gear ring. Several slots are evenly spaced on the base. A positioning frame is slidably installed in each slot. A positioning spring is connected between each positioning frame and each slot. An internal gear ring is installed at the bottom of the chassis. Several positioning frames are locked in the teeth of the internal gear ring.

[0011] The beneficial effects of this invention are: 1. The coupling body can be corrected and fixed by moving the three initial straightening frames closer to each other, and the spline sleeve can be corrected and fixed by moving the three swing frames closer to each other, so that the center of the spline sleeve is aligned with the center of the coupling body. In this way, coupling bodies and spline sleeves of different specifications can be corrected and fixed, improving the applicability of this tooling and improving the efficiency of fixing the coupling body and spline sleeve. At the same time, it is easier for the operator to use a welding torch to weld the coupling body and spline sleeve together more accurately.

[0012] 2. The three swing arms are driven by the swing teeth to swing from a vertical position to a horizontal position. The three swing arms drive the three lower pressure arms and the three compression springs to swing downwards to a horizontal position. After the three lower pressure arms contact the top of the spline sleeve, the three compression springs will be stretched. The three lower pressure arms can press the spline sleeve, so that the bottom of the spline sleeve is tightly attached to the top of the coupling body, thereby preventing the spline sleeve from loosening during welding and improving the quality of the spline sleeve welding on the coupling body.

[0013] 3. By cooperating with the positioning bracket and the internal gear ring, the cover cylinder can be limited, making it less likely for the coupling body and spline sleeve on the cover cylinder to wobble during welding, thereby further improving the quality of the spline sleeve welding onto the coupling body. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural diagram of the initial state of the present invention.

[0015] Figure 2 This is a three-dimensional structural diagram of the present invention in its working state.

[0016] Figure 3 This is a three-dimensional structural diagram showing the disassembled base, rotating rod, chassis, and cover cylinder of the present invention.

[0017] Figure 4 This is a three-dimensional structural diagram of the primary correction mechanism and the secondary correction mechanism of the present invention.

[0018] Figure 5 This is a three-dimensional structural diagram of the preliminary correction mechanism, locking mechanism, and secondary correction mechanism of the present invention.

[0019] Figure 6 This is a three-dimensional structural diagram of the locking mechanism and the secondary correction mechanism of the present invention.

[0020] Figure 7 This is a three-dimensional structural diagram of the secondary correction mechanism of the present invention.

[0021] Figure 8 This is a three-dimensional structural diagram showing the disassembled parts of the preliminary correction mechanism and locking mechanism of the present invention.

[0022] Figure 9 This is a three-dimensional structural diagram showing the disassembled parts of the secondary correction mechanism and the pressing mechanism of the present invention.

[0023] Figure 10 This is a three-dimensional structural diagram of the limiting mechanism of the present invention.

[0024] The components in the attached diagram are labeled as follows: 1_base, 2_rotating rod, 3_chassis, 4_cover sleeve, 41_coupling body, 42_spline sleeve, 51_guide rail, 52_electric slider, 521_lower magnet, 53_initial straightening frame, 531_upper magnet, 61_guide sleeve, 62_threaded clamping rod, 63_spur gear, 64_drive rack, 71_slide groove, 72_hollow slide, 73_reset spring, 74_positioning rod, 75_double rack frame, 76_slot frame, 761_sliding frame, 77_swing frame, 78_swing gear, 79_vertical rack frame, 8_handle, 91_lower pressure frame, 92_compression spring, 101_slotted, 102_positioning frame, 103_positioning spring, 104_internal gear ring. Detailed Implementation

[0025] The following description is only a preferred embodiment of the present invention and does not limit the scope of protection of the present invention.

[0026] Example 1: A welding fixture for couplings, such as Figures 1-9 As shown, the device includes a base 1, a rotating rod 2, a chassis 3, a cover 4, a preliminary straightening mechanism, a locking mechanism, and a secondary straightening mechanism. The rotating rod 2 is rotatably mounted on the base 1 via bearings. The chassis 3 is bolted to the top of the rotating rod 2. The cover 4 is mounted on the chassis 3. The coupling body 41 is placed on the cover 4. The spline sleeve 42 to be welded is placed on the coupling body 41. The chassis 3 and the cover 4 are equipped with a preliminary straightening mechanism for straightening the coupling body 41. The cover 4 and the preliminary straightening mechanism are equipped with a locking mechanism for locking the preliminary straightening mechanism. The cover 4 is equipped with a secondary straightening mechanism for straightening the spline sleeve 42.

[0027] The preliminary correction mechanism includes guide rails 51, electric sliders 52, lower magnets 521, primary correction frames 53, and upper magnets 531. Three guide rails 51 are evenly spaced on the chassis 3 by bolts. Each of the three guide rails 51 is equipped with an electric slider 52 that slides along the guide rails 51. Each electric slider 52 is equipped with a lower magnet 521. Three primary correction frames 53 are evenly spaced on the cover cylinder 4. Each primary correction frame 53 is equipped with an upper magnet 531 at its lower part. All three upper magnets 531 are located inside the cover cylinder 4. The magnetic poles of the three lower magnets 521 and the three upper magnets 531 are opposite on the side that is close to each other, and the three lower magnets 521 and the three upper magnets 531 attract each other.

[0028] The locking mechanism includes guide sleeves 61, threaded locking rods 62, spur gears 63, and drive racks 64. Three guide sleeves 61 are evenly spaced at the top of the cover cylinder 4. The lower parts of the three primary straightening frames 53 are slidably connected to the three guide sleeves 61 respectively. Each guide sleeve 61 has a threaded locking rod 62 threadedly connected to both sides. The sides of the two threaded locking rods 62 that are close to each other are located on both sides of the primary straightening frame 53. Both sides of the three primary straightening frames 53 are set with rough surfaces. The sides of the two threaded locking rods 62 that are close to each other are also set with rough surfaces. A spur gear 63 is installed on the sides of the two threaded locking rods 62 that are far from each other. The two spur gears 63 on each guide sleeve 61 form a group. A drive rack 64 is installed on both sides of each electric slider 52. Each drive rack 64 is located diagonally below each spur gear 63. After the drive rack 64 moves, it will mesh with the spur gear 63.

[0029] The secondary correction mechanism includes a hollow slide 72, a return spring 73, a positioning rod 74, a double rack frame 75, a slot frame 76, a sliding frame 761, a swing frame 77, a swing tooth 78, and a vertical rack frame 79. Three evenly spaced sliding grooves 71 are evenly spaced on the cover cylinder 4. A hollow slide 72 is slidably installed in each of the three grooves 71, and the hollow slide 72 slides along the groove 71. A return spring 73 is connected between each of the three hollow slides 72 and the three grooves 71. A positioning rod 74 is installed on the side of each of the three grooves 71 near the return spring 73. The other end of the positioning rod 74 contacts one side of each of the three hollow slides 72. The three return springs 73 are wound around the three positioning rods 74. Three double rack frames 75 are evenly spaced and slidably installed at the top of the cover cylinder 4. Each... Each double rack frame 75 meshes with two spur gears 63 in each group. A slot frame 76 is installed on one side of each of the three double rack frames 75 that are close to each other. Each slot frame 76 has a drive slot, and each drive slot consists of an inclined part and a horizontal part. Each hollow slide 72 has a sliding frame 761 that is slidably installed inside. The bottom of each sliding frame 761 is slidably connected to the drive slot in each slot frame 76. Each hollow slide 72 has a swing frame 77 that is rotatably installed on its top. Each swing frame 77 has a swing tooth 78 installed on both sides. The two swing teeth 78 on each swing frame 77 form a group. Each slide frame 761 has a vertical rack frame 79 that is bolted to its top. Each vertical rack frame 79 meshes with the two swing teeth 78 in each group.

[0030] During welding, the operator first places the coupling body 41 at the center of the cover sleeve 4, and then places the spline sleeve 42 on the coupling body 41. The three hollow slides 72 are all located inside the coupling body 41 and the spline sleeve 42. The operator activates the three electric sliders 52 to move them closer together along the three guide rails 51. The three electric sliders 52 drive the three lower magnets 521 to move closer together, which in turn drive the three upper magnets 531, the initial straightening frame 53, and the drive rack 64 to move closer together. The three initial straightening frames 53, moving closer together, push the coupling body 41 and the spline sleeve 42 to move. The three initial straightening frames 53 can perform preliminary straightening of the coupling body 41 and the spline sleeve 42, facilitating precise welding of the coupling body 41 and the spline sleeve 42 by the operator. Once the coupling body 41 is positioned, the three electric sliders 52... The moving slider 52 continues to drive the three lower magnets 521 and the drive rack 64 to move closer to each other. Since the three primary straightening frames 53 and the three upper magnets 531 are blocked by the coupling body 41 and no longer move, the three lower magnets 521 will separate from the three upper magnets 531. The three electric sliders 52 drive the six drive racks 64 to move closer to each other. The six drive racks 64 mesh with the six spur gears 63. The six drive racks 64 will drive the six spur gears 63 to rotate. The rotation of the six spur gears 63 will drive the six threaded rods 62 to rotate. The two threaded rods 62 on each guide sleeve 61 will move closer to each other. The two threaded rods 62 on each guide sleeve 61 fix the primary straightening frames 53 on each guide sleeve 61 respectively. The threaded rods 62 will drive the spur gears 63 on them to move respectively, but the spur gears 63 will not disengage from the drive racks 64.The rotation of six column gears 63 drives three double rack frames 75 to move away from each other. The three double rack frames 75 drive three slot frames 76 to move away from each other. The positioning rod 74 holds the hollow slide frame 72, preventing the three hollow slide frames 72 from moving away from each other. Initially, the lower part of the slide frame 761 is slidably connected to the inclined part of the drive slot on the slot frame 76. Under the action of the inclined part of the drive slot on the slot frame 76, the three slide frames 761 will move downward. The three slide frames 761 drive the three vertical rack frames 79 to move downward. The three vertical rack frames 79 drive the six swing teeth 78 to rotate. The swing teeth 78 drive the three swing frames 77 to swing from a vertical position to a horizontal position. The three electric sliders 52 continue to move. The system will contact three hollow slides 72, which will drive three double rack supports 75, three sliding supports 761, three swing supports 77, six swing teeth 78, and three vertical rack supports 79 to move closer to each other. At this time, the lower part of the sliding support 761 slides in the horizontal part of the drive groove on the slot support 76. The three horizontally swinging supports 77 moving closer to each other will push the spline sleeve 42 to move. Through the three horizontally swinging supports 77, the spline sleeve 42 can be further corrected so that the center of the spline sleeve 42 is aligned with the center of the coupling body 41, which facilitates more precise welding of the coupling body 41 and the spline sleeve 42 by the operator. After the center of the main body 41 is aligned, the operator controls the three electric sliders 52 to stop moving. The three initial straightening frames 53 can be moved closer together to straighten and fix the coupling body 41. The three swing frames 77 can be moved closer together to straighten and fix the spline sleeve 42. This allows for the straightening and fixing of coupling bodies 41 and spline sleeves 42 of different specifications, improving the applicability of the tooling and increasing the efficiency of fixing the coupling body 41 and spline sleeve 42. Subsequently, the operator uses a welding torch to weld the coupling body 41 and spline sleeve 42 together. During welding, the operator can rotate the cover cylinder 4. The cover cylinder 4, the base 3, and the rotating rod 2 rotate along the base 1. The coupling body 41 and spline sleeve 42 on 4 will also rotate, which makes it convenient for the operator to weld the spline sleeve 42. After welding, the operator starts the three electric sliders 52 to move away from each other along the three guide rails 51. When the three electric sliders 52 are separated from the three hollow slides 72, under the action of the three return springs 73, the hollow slides 72 drive the three double rack frames 75, the three sliding frames 761, the three swing frames 77, the six swing teeth 78 and the three vertical rack frames 79 to move away from each other. The three hollow slides 72 re-contact the three positioning rods 74, and the three swing frames 77 that swing horizontally move away from each other and separate from the spline sleeve 42.As the three electric sliders 52 drive the six drive racks 64 and three lower magnets 521 to move away from each other, when the six drive racks 64 mesh with the six spur gears 63, the six drive racks 64 will drive the six spur gears 63 to rotate in the opposite direction. The reverse rotation of the six spur gears 63 will drive the six threaded clamps 62 to rotate in the opposite direction. The two threaded clamps 62 on each guide sleeve 61 will move away from each other, and the two threaded clamps 62 on each guide sleeve 61 will no longer fix the initial straightening frame 53 on each guide sleeve 61. The reverse rotation of the six spur gears 63 will drive the three double rack frames 75 to move closer to each other. The three double rack frames 75 will drive the three slot frames 76 to move towards each other. As the three sliding frames 761 move towards each other, under the action of the inclined part of the drive groove on the slot frame 76, the three sliding frames 761 will move upward. The three sliding frames 761 will drive the three vertical rack frames 79 to move upward. The three vertical rack frames 79 will drive the six swing teeth 78 to rotate in the opposite direction. The swing teeth 78 will drive the three swing frames 77 to swing from a horizontal position to a vertical position. Then, the three lower magnets 521 will re-attract to the three upper magnets 531. The three lower magnets 521 will drive the three upper magnets 531, the three initial straightening frames 53 and the six drive racks 64 to move away from each other. The three initial straightening frames 53 will separate from the coupling body 41. The operator can then remove the welded coupling body 41 and spline sleeve 42.

[0031] Example 2: Based on Example 1, such as Figures 1-9 As shown, it also includes handles 8, with three handles 8 evenly spaced on the chassis 3.

[0032] It also includes a pressing mechanism, which is set on the swing frame 77. The pressing mechanism is used to press the spline sleeve 42. The pressing mechanism includes a pressing frame 91 and a compression spring 92. Each swing frame 77 is slidably provided with a pressing frame 91, and each pressing frame 91 is connected to a compression spring 92.

[0033] The operator can move the three handles 8 in sequence to more conveniently and precisely control the rotation angle of the cover cylinder 4, thereby making it easier and more precise to control the rotation angle of the coupling body 41 and the spline sleeve 42.

[0034] When the sway gear 78 drives the three swaying frames 77 to swing from a vertical position to a horizontal position, the three swaying frames 77 drive the three lower pressure frames 91 and the three compression springs 92 to swing downwards to a horizontal position. After the three lower pressure frames 91 contact the top of the spline sleeve 42, the three compression springs 92 will stretch. The three lower pressure frames 91 can press the spline sleeve 42, so that the bottom of the spline sleeve 42 is tightly attached to the top of the coupling body 41, thereby preventing the spline sleeve 42 from loosening during welding and improving the quality of the spline sleeve 42 welded to the coupling body 41. When the sway gear 78 drives the three swaying frames 77 to swing from a horizontal position to a vertical position, the three swaying frames 77 drive the three lower pressure frames 91 and the three compression springs 92 to swing upwards to a vertical position. The three lower pressure frames 91 no longer contact the spline sleeve 42.

[0035] Example 3: Based on Example 2, such as Figures 7-10 As shown, it also includes a limiting mechanism, which is set on the base 1 and the chassis 3. The limiting mechanism is used to limit the chassis 3 and the cover cylinder 4. The limiting mechanism includes a positioning frame 102, a positioning spring 103 and an internal gear ring 104. Three slots 101 are evenly spaced on the base 1. A positioning frame 102 is slidably installed in each slot 101. A positioning spring 103 is connected between each positioning frame 102 and each slot 101. An internal gear ring 104 is installed at the bottom of the chassis 3. The three positioning frames 102 are all locked in the teeth of the internal gear ring 104.

[0036] When the cover cylinder 4 rotates, it drives the internal gear ring 104 to rotate. The teeth in the internal gear ring 104 continuously contact and separate from the positioning frame 102. Under the action of the positioning spring 103, the positioning frame 102 continuously swings back and forth in the slot 101. Through the cooperation between the positioning frame 102 and the internal gear ring 104, the cover cylinder 4 can be limited, so that the coupling body 41 and spline sleeve 42 on the cover cylinder 4 are not easy to shake during welding, further improving the quality of the spline sleeve 42 welded to the coupling body 41.

[0037] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Therefore, all equivalent changes made to the content described in the claims of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A welding fixture for couplings, characterized in that: It includes a base (1), a rotating rod (2), a chassis (3), a cover sleeve (4), a preliminary straightening mechanism, a locking mechanism, and a secondary straightening mechanism. The rotating rod (2) is rotatably mounted on the base (1), and the chassis (3) is mounted on the top of the rotating rod (2). The cover sleeve (4) is mounted on the chassis (3), and the coupling body (41) is placed on the cover sleeve (4). The spline sleeve (42) to be welded is placed on the coupling body (41). The chassis (3) and the cover sleeve (4) are equipped with a preliminary straightening mechanism, which is used to straighten the coupling body (41). The cover sleeve (4) The initial correction mechanism is equipped with a locking mechanism to lock the initial correction mechanism. The cover tube (4) is equipped with a secondary correction mechanism to correct the spline sleeve (42). The initial correction mechanism includes a guide rail (51), an electric slider (52), a lower magnet (521), an initial correction frame (53), and an upper magnet (531). Several guide rails (51) are evenly spaced on the chassis (3). Each guide rail (51) is equipped with an electric slider (52) that slides on it. Each electric slider (52) is equipped with a lower magnet. Magnet (521), several primary straightening frames (53) are evenly spaced and slidably arranged on the cover cylinder (4). Each primary straightening frame (53) has an upper magnet (531) installed at its lower part. Several upper magnets (531) are located inside the cover cylinder (4). The magnetic poles of the lower magnet (521) and the upper magnet (531) are opposite on the side that are close to each other, and the lower magnet (521) and the upper magnet (531) attract each other. The secondary straightening mechanism includes a hollow slide (72), a return spring (73), a positioning rod (74), a double rack frame (75), a slot frame (76), and a sliding frame. The cover cylinder (4) has several evenly spaced sliding grooves (71), each sliding groove (71) has a hollow slide (72) that slides in a sliding manner, and each hollow slide (72) is connected to each sliding groove (71) with a return spring (73). Each sliding groove (71) has a positioning rod (74) installed on the side near the return spring (73), and the other end of each positioning rod (74) is in contact with one side of each hollow slide (72).

2. A coupling welding fixture according to claim 1, characterized in that: The locking mechanism includes a guide sleeve (61), a threaded rod (62), a spur gear (63), and a drive rack (64). Several guide sleeves (61) are evenly spaced at the top of the cover cylinder (4). The lower parts of several primary straightening frames (53) are slidably connected to several guide sleeves (61). Each guide sleeve (61) has a threaded rod (62) threadedly connected to both sides. The side of the two threaded rods (62) that are close to each other is located on both sides of the primary straightening frame (53). The side of the two threaded rods (62) that are far apart from each other is equipped with a spur gear (63). The two spur gears (63) on each guide sleeve (61) form a group. Each electric slider (52) has a drive rack (64) installed on both sides. Each drive rack (64) is located diagonally below each spur gear (63).

3. A coupling welding fixture according to claim 2, characterized in that: The top of the cover cylinder (4) is provided with several double rack frames (75) at even intervals. Each double rack frame (75) meshes with two spur gears (63) of each group. A slot frame (76) is installed on the side of each double rack frame (75) that is close to each other. Each slot frame (76) has a drive slot. Each drive slot consists of an inclined part and a horizontal part. A sliding frame (761) is provided in each hollow slide (72). The bottom of each sliding frame (761) is slidably connected to the drive slot in each slot frame (76). A swing frame (77) is rotatably installed on the top of each hollow slide (72). A swing tooth (78) is installed on both sides of each swing frame (77). The two swing teeth (78) on each swing frame (77) form a group. A vertical rack frame (79) is installed on the top of each sliding frame (761). Each vertical rack frame (79) meshes with the two swing teeth (78) of each group.

4. A coupling welding fixture according to claim 3, characterized in that: It also includes handles (8), and several handles (8) are evenly spaced on the chassis (3).

5. A coupling welding fixture according to claim 4, characterized in that: It also includes a pressing mechanism, which is set on the swing frame (77). The pressing mechanism is used to press the spline sleeve (42). The pressing mechanism includes a pressing frame (91) and a compression spring (92). Each swing frame (77) is slidably provided with a pressing frame (91), and each pressing frame (91) is connected to each swing frame (77) with a compression spring (92).

6. A coupling welding fixture according to claim 5, characterized in that: It also includes a limiting mechanism, which is set on the base (1) and chassis (3). The limiting mechanism is used to limit the chassis (3) and cover cylinder (4). The limiting mechanism includes a positioning frame (102), a positioning spring (103) and an internal gear ring (104). Several slots (101) are evenly spaced on the base (1). A positioning frame (102) is slidably provided in each slot (101). A positioning spring (103) is connected between each positioning frame (102) and each slot (101). An internal gear ring (104) is installed at the bottom of the chassis (3). Several positioning frames (102) are locked in the teeth of the internal gear ring (104).

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