Self-centering fixture for welding a rotary cultivator beam tube and flanges

Abstract

The application provides a self-centering clamp for welding a rotary cultivator beam pipe and a flange, comprising a transmission mechanism, a clamping mechanism, a movable core and a supporting mechanism, the supporting mechanism comprises a positioning support, the positioning support is upwardly provided with a first support and a second support, one end of the transmission mechanism is movably connected to the first support, the other end of the transmission mechanism is fixed with the movable core, the movable core is provided with a center guide protruding shaft and a division positioning protruding shaft, the second support is provided with a center guide hole and a division positioning hole, one end of the clamping mechanism is drivingly connected with the transmission mechanism, and the clamping mechanism is hinged to the top of the second support. Thus, when the transmission mechanism drives the movable core to move so that the division positioning protruding shaft penetrates through the division positioning hole to be inserted into the flange for positioning, and the clamping mechanism is driven to abut against the beam pipe, the centering and clamping are simultaneously performed, the positioning is accurate, the concentricity is high, the clamping is stable, the operation process is convenient, and the self-centering clamp is suitable for batch production.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery technology, and in particular to a self-centering clamp for welding the crossbeam tube and flange of a rotary tiller. Background Technology

[0002] A rotary tiller is a type of soil tillage machinery that uses rotating blades as its working parts. It is also known as a rotary tiller. The frame of a rotary tiller usually has a crossbeam tube, and both ends of the crossbeam tube need to be welded to the flange as a whole. In order to ensure the normal use of the machine, the concentricity of the crossbeam tube and the flange must be ensured.

[0003] In the existing technology, the welding structure of flange beams generally adopts the method of pre-processing the flange and the locating end of the beam pipe separately, and then welding or post-weld integral processing to ensure concentricity. This method is relatively complex and inefficient. In addition, due to the large volume of the beam, the overall quality is difficult to control, making it unsuitable for mass production.

[0004] Therefore, it is necessary to propose a self-centering fixture for welding the crossbeam tubes and flanges of rotary tillers to solve or at least alleviate the above-mentioned defects. Summary of the Invention

[0005] The main objective of this invention is to provide a self-centering fixture for welding the crossbeam tube and flange of a rotary tiller, so as to solve the problem that the concentric welding structure in the prior art is relatively complex, resulting in low efficiency and unsuitability for mass production.

[0006] To achieve the above objectives, the present invention provides a self-centering clamp for welding the crossbeam tube and flange of a rotary tiller, comprising two self-centering clamp structures arranged opposite each other along the extension direction of the crossbeam tube, wherein each of the self-centering clamp structures includes a transmission mechanism, a clamping mechanism, a movable centering element, and a support mechanism; wherein,

[0007] The support mechanism includes a positioning support, which has two protruding supports and a second support that are arranged opposite each other along its own length. One end of the transmission mechanism is movably connected to the first support along the extension direction of the crossbeam tube, and the other end of the transmission mechanism is fixedly connected to the movable core.

[0008] The movable core is provided with a central guide cam and a plurality of indexing and positioning cams for connecting with the flange on the side near the second support. The second support is provided with a central guide hole corresponding to the central guide cam and a plurality of indexing and positioning holes corresponding one-to-one with the indexing and positioning cam.

[0009] One end of the clamping mechanism is connected to the transmission mechanism, the other end of the clamping mechanism is used to abut against the crossbeam tube, and the middle part of the clamping mechanism is hinged to the top of the second support.

[0010] When the transmission mechanism moves toward the second support, it drives the movable centering shaft to move so that the indexing positioning cam passes through the indexing positioning hole and is inserted into the flange for positioning, and drives the clamping mechanism to swing around the top of the second support to clamp the crossbeam tube.

[0011] Preferably, the transmission mechanism includes a double-threaded shaft, a force-transmitting bearing, and a movable sleeve, wherein the force-transmitting bearing is rotatably mounted on the top of the first support.

[0012] The double-threaded shaft includes a first end and a second end arranged opposite to each other along the axial direction. The first end of the double-threaded shaft passes through and extends out of the force transmission bearing. The second end of the double-threaded shaft has an external thread and an internal thread. The movable sleeve has an internal thread hole that matches the external thread of the double-threaded shaft, so that the movable sleeve is sleeved on the second end of the double-threaded shaft. One end of the clamping mechanism is drivenly connected to the movable sleeve.

[0013] The movable core has an external threaded shaft protruding on the side away from the second support. The external threaded shaft of the movable core is matched with the internal thread of the double threaded shaft so that the external threaded shaft of the movable core is connected to the inner side of the double threaded shaft.

[0014] Preferably, the clamping mechanism includes a plurality of clamping units arranged at intervals along the circumference of the movable clamping sleeve. The movable clamping sleeve is provided with a plurality of lugs that correspond one-to-one with the clamping units along its own circumference. The top of the second support is provided with a plurality of ear plates that correspond one-to-one with the lugs. Each clamping unit includes a connecting rod and a gripper.

[0015] One end of the connecting rod is hinged to the support lug via a rivet pin. The gripper includes a connecting end and a clamping end arranged opposite to each other. The other end of the connecting rod is hinged to the connecting end of the gripper via a rivet pin. The middle part of the gripper is hinged to the lug via a rivet pin.

[0016] Preferably, the clamping unit further includes a clamping wheel, and the clamping end of the jaw has an installation space for mounting the clamping wheel, the clamping wheel being hinged to the installation space by a rivet pin.

[0017] Preferably, the system further includes a guiding mechanism, which includes a guide groove and a guide block. The guide groove is fixed to the side wall of the first support by bolts, and a sliding space is formed between the guide groove and the double-threaded shaft. The guide block is fixed to the bottom of the movable sleeve and abuts against the guide groove, so that the guide block is slidably disposed in the sliding space along the extension direction of the guide groove.

[0018] Preferably, the support mechanism further includes a clamping platform and an auxiliary bracket for assisting in supporting the crossbeam tube. The top of the auxiliary bracket is arranged in an arc shape with the opening facing upward. Both the positioning support and the auxiliary bracket are fixed on the clamping platform, and the auxiliary bracket is arranged close to the second support.

[0019] Preferably, the double-threaded shaft, the central guide cam, and the central guide hole are arranged on the same axis.

[0020] Preferably, it also includes a bearing cover, wherein a semi-circular groove is formed in the top recess of the first support, the bearing cover is placed on the semi-circular groove, and a limiting space is formed between the bearing cover and the semi-circular groove, and the force transmission bearing is rotatably installed in the limiting space.

[0021] Preferably, it also includes a handwheel, which is fixedly connected to the first end of the double-threaded shaft by a cap nut.

[0022] Preferably, it further includes a spacer sleeve, which is sleeved on the first end of the double-threaded shaft and disposed between the handwheel and the force transmission bearing.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention provides a self-centering clamp for welding the crossbeam tube and flange of a rotary tiller, comprising two self-centering clamp structures arranged opposite each other along the extension direction of the crossbeam tube. Each self-centering clamp structure includes a transmission mechanism, a clamping mechanism, a movable center, and a support mechanism. The support mechanism includes a positioning support, with a first support and a second support protruding upward from the positioning support. One end of the transmission mechanism is movably connected to the first support, and the other end of the transmission mechanism is fixedly connected to the movable center. The movable center has a central guide cam and a plurality of indexing positioning cams for connecting to the flange protruding on the side near the second support. The second support has a central guide hole corresponding to the central guide cam and a plurality of indexing positioning holes corresponding one-to-one with the indexing positioning cams. One end of the clamping mechanism is drivenly connected to the transmission mechanism, and the other end of the clamping mechanism is used to abut against the crossbeam tube, and the middle part of the clamping mechanism is hinged to the top of the second support. When the transmission mechanism moves toward the second support, it drives the movable centering shaft to move so that the indexing positioning cam passes through the indexing positioning hole and is inserted into the flange for positioning. It also drives the clamping mechanism to swing around the top of the second support to abut against the crossbeam tube, thus achieving synchronous centering and clamping. This results in accurate positioning, high concentricity, stable clamping, and convenient operation, making it suitable for mass production. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0026] Figure 1 This is a cross-sectional schematic diagram of a self-centering clamping structure during positioning and clamping in one embodiment of the present invention;

[0027] Figure 2 This is a three-dimensional schematic diagram of the overall structure in an application scenario according to one embodiment of the present invention;

[0028] Figure 3 This is a cross-sectional and three-dimensional schematic diagram of the overall structure when it is loosened in one embodiment of the present invention.

[0029] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings.

[0030] Explanation of icon numbers:

[0031] 10. Transmission mechanism; 110. Double threaded shaft; 111. Spacer; 120. Force transmission bearing; 121. Bearing cover; 130. Movable clamp; 131. Support lug; 140. Handwheel; 20. Clamping mechanism; 210. Clamping unit; 211. Connecting rod; 212. Gripper; 213. Clamping wheel; 30. Movable centering; 310. Central guide cam; 320. Indexing and positioning cam; 330. External threaded shaft; 340. Guide mechanism; 341. Guide groove; 342. Guide block; 40. Support mechanism; 410. First support; 420. Second support; 421. Central guide hole; 422. Indexing and positioning hole; 423. Ear plate; 430. Fixture platform; 440. Auxiliary bracket; 50. Crossbeam tube; 60. Flange. Detailed Implementation

[0032] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0035] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0036] Please see the appendix Figure 1-3This invention provides a self-centering fixture for welding a rotary tiller crossbeam tube 50 and a flange 60, comprising two self-centering fixture structures arranged opposite each other along the extension direction of the crossbeam tube 50. Each self-centering fixture structure includes a transmission mechanism 10, a clamping mechanism 20, a movable centering mechanism 30, and a support mechanism 40. First, it should be noted that, unlike the prior art where the welding structure of the flange 60 crossbeam generally involves pre-machining the flange 60 disc and the mating stop of the crossbeam tube 50, and then welding or post-weld integral machining to ensure concentricity, this method is complex and inefficient. Furthermore, due to the large volume of the crossbeam, the overall quality is difficult to control, making it unsuitable for mass production. This application addresses the above-mentioned deficiencies in the prior art by providing a self-centering fixture for welding a rotary tiller crossbeam tube 50 and a flange 60.

[0037] Specifically as follows:

[0038] The support mechanism 40 includes a positioning support. The positioning support has two first supports 410 and second supports 420 that are arranged opposite each other along its own length direction. One end of the transmission mechanism 10 is movably connected to the first support 410 along the extension direction of the crossbeam tube 50, and the other end of the transmission mechanism 10 is fixedly connected to the movable core 30. The movable core 30 has a central guide shaft 310 and a plurality of indexing positioning shafts 320 for connecting with the flange 60 protruding on the side near the second support 420. The second support 420 has a central guide hole 421 corresponding to the central guide shaft 310 and a plurality of indexing positioning holes 422 corresponding one-to-one with the indexing positioning shafts 320.

[0039] Specifically, the self-centering clamp for welding the crossbeam tube 50 and flange 60 of a rotary tiller in this application includes two self-centering clamp structures. The two self-centering clamp structures are arranged opposite each other along the extension direction of the crossbeam tube 50 to simultaneously fix both ends of the crossbeam tube 50, thereby ensuring the concentricity of both ends of the crossbeam tube 50 and the flange 60. Each self-centering clamp structure includes a transmission mechanism 10, a clamping mechanism 20, a movable centering element 30, and a support mechanism 40. The transmission mechanism 10 is used to drive the clamping mechanism 20 and the movable centering element 30 to move through its own movement. The clamping mechanism 20 is used to clamp the crossbeam tube 50 to prevent the crossbeam tube 50 from shifting during welding. The movable centering element 30 is used to fix the flange 60 to position the flange 60. The support mechanism 40 is used for mounting the transmission mechanism 10 and the clamping mechanism 20, and at the same time for fixing and supporting the crossbeam tube 50.

[0040] The support mechanism 40 includes a positioning support. The positioning support has two opposing first supports 410 and second supports 420 protruding upwards along its length. The first supports 410 are used to mount the transmission mechanism 10, allowing one end of the transmission mechanism 10 to be movably connected to the first supports 410 along the extension direction of the crossbeam tube 50, while the other end of the transmission mechanism 10 is fixedly connected to the movable core 30, facilitating the transmission mechanism 10 to drive the movable core 30 to move back and forth. Furthermore, the movable core 30 mates with the flange 60. A central guide shaft 310 and multiple indexing positioning shafts 320 protrude from the side of the movable core 30 near the second supports 420. The central guide shaft 310 facilitates a sliding connection between the movable core 30 and the second supports 420. Therefore, a central guide hole 421 corresponding to the central guide shaft 310 is provided on the second supports 420. Here, "correspondingly provided" refers to the central guide... The convex shaft 310 and the central guide hole 421 are of the same size and coaxially aligned. Simultaneously, the indexing and positioning convex shaft 320 is used to position the flange 60. Since the flange 60 typically has multiple flange 60 connection holes along its circumference, when the transmission mechanism 10 moves the movable centering shaft 30, it moves the indexing and positioning convex shaft 320 to position the flange 60. Therefore, multiple indexing and positioning holes 422 corresponding one-to-one with the indexing and positioning convex shaft 320 need to be provided on the second support 420. The one-to-one correspondence setting means that the indexing positioning cam 320 and the indexing positioning hole 422 are the same size and coaxially arranged, so that when the movable centering 30 moves toward the second support 420, the center guide cam 310 extends through the center guide hole 421 to slide with the second support 420, while the indexing positioning cam 320 extends through the indexing positioning hole 422 and into the flange 60 connection hole of the flange 60 to position the flange 60, ensuring positioning accuracy.

[0041] One end of the clamping mechanism 20 is connected to the transmission mechanism 10, and the other end of the clamping mechanism 20 is used to abut against the crossbeam tube 50. The middle part of the clamping mechanism 20 is hinged to the top of the second support 420. When the transmission mechanism 10 moves toward the second support 420, it drives the movable centering 30 to move so that the indexing positioning cam 320 passes through the indexing positioning hole 422 to be inserted into the flange 60 for positioning, and drives the clamping mechanism 20 to swing around the top of the second support 420 to clamp the crossbeam tube 50.

[0042] In detail, one end of the clamping mechanism 20 is connected to the transmission mechanism 10. Thus, when the transmission mechanism 10 moves, the clamping mechanism 20 moves along with it. During this movement, since the middle of the clamping mechanism 20 is hinged to the top of the second support 420, when the transmission mechanism 10 pushes towards the second support 420, leveraging the lever principle, the clamping mechanism 20 swings around the top of the second support 420, causing the other end of the clamping mechanism 20 to abut against the crossbeam tube 50, forming a clamping state for stability. The crossbeam tube 50 is fixed. When the transmission mechanism 10 moves toward the second support 420, it drives the movable centering 30 forward and simultaneously drives the clamping mechanism 20. The two are carried out synchronously. At this time, the indexing positioning cam 320 passes through the indexing positioning hole 422 to be inserted into the flange 60 for positioning, while the clamping mechanism 20 swings around the top of the second support 420 to clamp the crossbeam tube 50, so as to achieve synchronous centering and synchronous clamping, improve the concentricity during welding, improve production accuracy, and the structure is convenient to operate and speeds up production efficiency.

[0043] In a preferred embodiment of the present invention, the transmission mechanism 10 includes a double-threaded shaft 110, a force-transmitting bearing 120, and a movable sleeve 130. The force-transmitting bearing 120 is rotatably mounted on the top of the first support 410. The double-threaded shaft 110 includes a first end and a second end arranged axially opposite to each other. The first end of the double-threaded shaft 110 passes through and extends out of the force-transmitting bearing 120. The second end of the double-threaded shaft 110 has external threads and internal threads. The movable sleeve 130 has a connection with the double-threaded bearing 120. The threaded shaft 110 has an internal threaded hole that matches the external thread, so that the movable sleeve 130 is sleeved on the second end of the double threaded shaft 110. One end of the clamping mechanism 20 is connected to the movable sleeve 130 in a driving connection. The movable core 30 has an external threaded shaft 330 protruding on the side away from the second support 420. The external threaded shaft 330 of the movable core 30 is matched with the internal thread of the double threaded shaft 110, so that the external threaded shaft 330 of the movable core 30 is connected to the inner side of the double threaded shaft 110.

[0044] It should be noted that the transmission mechanism 10 includes a double-threaded shaft 110, a force-transmitting bearing 120, and a movable sleeve 130. The double-threaded shaft 110 facilitates simultaneous internal and external threaded connection, making connection convenient and disassembly easy. The force-transmitting bearing 120 supports the rotating body (double-threaded shaft 110) to reduce its coefficient of friction during rotation. It is rotatably mounted on the top of the first support 410, with the first end of the double-threaded shaft 110 passing through the force-transmitting bearing 120, and extending beyond the force-transmitting bearing 120 for easy operation by the operator. The double-threaded shaft 110... The second end has external and internal threads. The external thread is used for the installation connection of the movable sleeve 130. Therefore, the movable sleeve 130 has an internal thread hole that matches the external thread of the double-threaded shaft 110, so that the movable sleeve 130 is sleeved on the second end of the double-threaded shaft 110. Since one end of the clamping mechanism 20 is connected to the movable sleeve 130 in a transmission manner, the movable sleeve 130 is circumferentially rotated and limited. Thus, when the double-threaded shaft 110 is rotated, due to the threaded connection, the double-threaded shaft 110 rotates at its original position, while the movable sleeve 130 rotates at its original position. If the circumferential limit cannot rotate synchronously, relative movement occurs, allowing the double-threaded shaft 110 to move back and forth along its length direction according to its rotation direction. During this movement, the movable sleeve 130 also drives the clamping mechanism 20 to swing around the top of the second support 420. Furthermore, the internal thread of the double-threaded shaft 110 is used for connection to the movable centering shaft 30. The movable centering shaft 30 has an external threaded shaft 330 protruding from its side away from the second support 420, and the external threaded shaft 330 of the movable centering shaft 30 is matched with the internal thread of the double-threaded shaft 110, thus enabling… The external threaded shaft 330 of the movable core 30 is connected to the inner side of the double threaded shaft 110. Similarly, since the movable core 30 has its central guide cam 310 and indexing positioning cam 320 passing through the central guide hole 421 and indexing positioning hole 422 respectively, a circumferential limit is generated, which prevents the movable core 30 from rotating synchronously with the double threaded shaft 110. Therefore, the external threaded shaft 330 of the connected movable core 30 also drives the movable core 30 to move back and forth along the length direction of the double threaded shaft 110 through relative motion, thereby realizing the positioning and separation of the flange 60.

[0045] In a preferred embodiment of the present invention, the clamping mechanism 20 includes a plurality of clamping units 210 arranged circumferentially along the movable clamping sleeve 130. The movable clamping sleeve 130 is provided with a plurality of lugs 131 corresponding to the clamping units 210 in its circumferential direction. The top of the second support 420 is provided with a plurality of ear plates 423 corresponding to the lugs 131 in their respective positions. Each clamping unit 210 includes a connecting rod 211 and a jaw 212. One end of the connecting rod 211 is hinged to the lug 131 by a rivet pin. The jaw 212 includes a connecting end and a clamping end arranged opposite to each other. The other end of the connecting rod 211 is hinged to the connecting end of the jaw 212 by a rivet pin. The middle part of the jaw 212 is hinged to the ear plate 423 by a rivet pin.

[0046] It should be noted that the clamping mechanism 20 includes multiple clamping units 210. These clamping units 210, arranged circumferentially along the movable sleeve 130, abut against the crossbeam tube 50 to achieve clamping. Therefore, for ease of installation, the movable sleeve 130 is provided with multiple lugs 131 that correspond one-to-one with the clamping units 210. Each clamping unit 210 is matched with one lug 131 for hinged connection at one end. On the top of the second support 420, multiple ear plates 423 are provided, corresponding one-to-one with the lugs 131. Here, "one-to-one correspondence" means that the number of ear plates 423 is the same and they are located on the same longitudinal horizontal axis. The ear plates 423 are used for hinged connection. The other end of the clamping unit 210 is hinged; wherein, each clamping unit 210 includes a connecting rod 211 and a gripper 212. One end of the connecting rod 211 is hinged to the lug 131 by a rivet pin, and the gripper 212 includes a connecting end and a clamping end arranged opposite to each other. The other end of the connecting rod 211 is hinged to the connecting end of the gripper 212 by a rivet pin. Thus, when the movable sleeve 130 moves, the connecting rod 211 moves accordingly, and the gripper 212 is transmitted according to the principle of the connecting rod 211. Furthermore, the swing range of the gripper 212 is limited by the fact that the middle part of the gripper 212 is hinged to the lug 423 by a rivet pin, thereby allowing the gripper 212 to swing around the lug 423 to achieve the clamping and releasing of the crossbeam tube 50.

[0047] In a preferred embodiment of the present invention, the clamping unit 210 further includes a clamping wheel 213, and the clamping end of the jaw 212 has an installation space for mounting the clamping wheel 213. The clamping wheel 213 is hinged to the installation space by a rivet pin.

[0048] It is worth noting that the clamping unit 210 also includes a clamping wheel 213. The clamping wheel 213 is used to increase the contact area between the gripper 212 and the crossbeam tube 50, and to make the contact smoother during clamping, so as to avoid damage to the crossbeam tube 50 during clamping. The clamping end of the gripper 212 has an installation space, which is used for the installation of the clamping wheel 213, so that the clamping wheel 213 can be rotatably connected to the installation space.

[0049] In a preferred embodiment of the present invention, a guide mechanism 340 is further included. The guide mechanism 340 includes a guide groove 341 and a guide block 342. The guide groove 341 is fixed to the side wall of the first support 410 by bolts. A sliding space is formed between the guide groove 341 and the double threaded shaft 110. The guide block 342 is fixed to the bottom of the movable sleeve 130 and abuts against the guide groove 341 so that the guide block 342 is slidably disposed in the sliding space along the extension direction of the guide groove 341.

[0050] It is worth noting that the guide mechanism 340 is used to increase the circumferential limit when the movable sleeve 130 moves, making it easier for the movable sleeve 130 to move relative to the others, and requiring less effort from the operator when rotating the double threaded shaft 110. The guide mechanism 340 includes a guide groove 341 and a guide block 342. The guide groove 341 is used for limiting the movement and is fixed to the side wall of the first support 410 by bolts, forming a sliding space between it and the double threaded shaft 110. The guide block 342 is used to connect the sliding sleeve so that the sliding sleeve is confined in the sliding space, and can only slide in the sliding space along the extension direction of the guide groove 341.

[0051] Furthermore, the support mechanism 40 also includes a clamping platform 430 and an auxiliary bracket 440 for assisting in supporting the crossbeam tube 50. The top of the auxiliary bracket 440 is arranged in an arc shape with the opening facing upward. Both the positioning support and the auxiliary bracket 440 are fixed on the clamping platform 430, and the auxiliary bracket 440 is arranged close to the second support 420.

[0052] It should be noted that the support mechanism 40 also includes a clamping platform 430 and an auxiliary bracket 440. The auxiliary bracket 440 is used to assist in supporting the crossbeam tube 50 so that the crossbeam tube 50 can be pre-erected at the target welding height, improving the stability during welding and further improving the welding accuracy. Its top is set in an arc shape with an opening facing upwards to match the crossbeam tube 50 and facilitate prevention. The clamping platform 430 is used for the installation of the positioning support and the auxiliary bracket 440 so that the positioning support and the auxiliary bracket 440 are both fixed on the clamping platform 430. It is worth mentioning that since the crossbeam tube 50 is erected between two flanges 60, the auxiliary bracket 440 is set close to the second support 420.

[0053] Furthermore, the double-threaded shaft 110, the central guide cam 310, and the central guide hole 421 are arranged coaxially.

[0054] It should be understood that the coaxial alignment of the double threaded shaft 110, the central guide cam 310, and the central guide hole 421 can facilitate increased concentricity and improved welding accuracy.

[0055] Furthermore, it also includes a bearing cover 121, the top of the first support 410 is recessed to form a semi-circular groove, the bearing cover 121 is covered on the semi-circular groove, the bearing cover 121 and the semi-circular groove together form a limiting space, and the force transmission bearing 120 is rotatably installed in the limiting space.

[0056] It should be noted that the bearing cover 121 is used to protect the force transmission bearing 120 to prevent dust, substances and impurities from entering the force transmission bearing 120, thereby increasing friction or causing wear on the double threaded shaft 110. The top of the first support 410 is recessed to form a semi-circular groove, which is used for the rotatable installation of the force transmission bearing 120. The bearing cover 121 is placed on the semi-circular groove to form a limiting space, which can further restrict the movement of the force transmission bearing 120, so that it can only rotate in its original position and avoid axial displacement.

[0057] Furthermore, it also includes a handwheel 140, which is fixedly connected to the first end of the double-threaded shaft 110 by a cap nut.

[0058] It should be noted that the handwheel 140 is designed for the operator to hold, making it convenient and effortless to operate.

[0059] Furthermore, it also includes a spacer 111, which is sleeved on the first end of the double-threaded shaft 110 and disposed between the handwheel 140 and the force transmission bearing 120.

[0060] It is understood that the spacer 111 can protect the double-threaded shaft 110 between the handwheel 140 and the force transmission bearing 120, preventing it from being exposed to air for a long time, thereby improving its service life. Therefore, it is sleeved on the first end of the double-threaded shaft 110 and positioned between the handwheel 140 and the force transmission bearing 120.

[0061] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A self-centering fixture for welding a tiller beam tube and a flange, characterized by, The system includes two self-centering clamping structures arranged opposite each other along the extension direction of the crossbeam tube. Each self-centering clamping structure includes a transmission mechanism, a clamping mechanism, a movable centering element, and a support mechanism. The support mechanism includes a positioning support, which has two protruding supports and a second support that are arranged opposite each other along its own length. One end of the transmission mechanism is movably connected to the first support along the extension direction of the crossbeam tube, and the other end of the transmission mechanism is fixedly connected to the movable core. The movable core is provided with a central guide cam and a plurality of indexing and positioning cams for connecting with the flange on the side near the second support. The second support is provided with a central guide hole corresponding to the central guide cam and a plurality of indexing and positioning holes corresponding one-to-one with the indexing and positioning cam. One end of the clamping mechanism is connected to the transmission mechanism, the other end of the clamping mechanism is used to abut against the crossbeam tube, and the middle part of the clamping mechanism is hinged to the top of the second support. When the transmission mechanism moves toward the second support, it drives the movable center to move so that the indexing positioning cam passes through the indexing positioning hole to be inserted into the flange for positioning, and drives the clamping mechanism to swing around the top of the second support to clamp the crossbeam tube. The transmission mechanism includes a double-threaded shaft, a force-transmitting bearing, and a movable sleeve. The force-transmitting bearing is rotatably mounted on the top of the first support. The double-threaded shaft includes a first end and a second end arranged opposite to each other along the axial direction. The first end of the double-threaded shaft passes through and extends out of the force transmission bearing. The second end of the double-threaded shaft has an external thread and an internal thread. The movable sleeve has an internal thread hole that matches the external thread of the double-threaded shaft, so that the movable sleeve is sleeved on the second end of the double-threaded shaft. One end of the clamping mechanism is drivenly connected to the movable sleeve. The movable core has an external threaded shaft protruding on the side away from the second support. The external threaded shaft of the movable core is matched with the internal thread of the double threaded shaft so that the external threaded shaft of the movable core is connected to the inner side of the double threaded shaft.

2. The self-centering clamp for welding the crossbeam tube and flange of a rotary tiller according to claim 1, characterized in that, The clamping mechanism includes multiple clamping units arranged at intervals along the circumference of the movable clamping sleeve. The movable clamping sleeve has multiple lugs protruding along its circumference, each corresponding to one of the clamping units. The top of the second support has multiple ear plates protruding, each corresponding to one of the lugs. Each clamping unit includes a connecting rod and a gripper. One end of the connecting rod is hinged to the support lug via a rivet pin. The gripper includes a connecting end and a clamping end arranged opposite to each other. The other end of the connecting rod is hinged to the connecting end of the gripper via a rivet pin. The middle part of the gripper is hinged to the lug via a rivet pin.

3. The self-centering clamp for welding the crossbeam tube and flange of a rotary tiller according to claim 2, characterized in that, The clamping unit further includes a clamping wheel, and the clamping end of the jaw has an installation space for mounting the clamping wheel. The clamping wheel is hinged to the installation space by a rivet pin.

4. The self-centering clamp for welding the crossbeam tube and flange of a rotary tiller according to claim 1, characterized in that, It also includes a guiding mechanism, which includes a guide groove and a guide block. The guide groove is fixed to the side wall of the first support by bolts. A sliding space is formed between the guide groove and the double threaded shaft. The guide block is fixed to the bottom of the movable sleeve and abuts against the guide groove so that the guide block is slidably disposed in the sliding space along the extension direction of the guide groove.

5. The self-centering clamp for welding the crossbeam tube and flange of a rotary tiller according to claim 1, characterized in that, The support mechanism also includes a clamping platform and an auxiliary bracket for assisting in supporting the crossbeam tube. The top of the auxiliary bracket is arranged in an arc shape with the opening facing upward. Both the positioning support and the auxiliary bracket are fixed on the clamping platform, and the auxiliary bracket is arranged close to the second support.

6. The self-centering clamp for welding the crossbeam tube and flange of a rotary tiller according to claim 1, characterized in that, The double-threaded shaft, the central guide cam, and the central guide hole are arranged coaxially.

7. The self-centering clamp for welding the crossbeam tube and flange of a rotary tiller according to claim 1, characterized in that, It also includes a bearing cover, the top of the first support is recessed to form a semi-circular groove, the bearing cover is placed on the semi-circular groove, the bearing cover and the semi-circular groove together form a limiting space, and the force transmission bearing is rotatably installed in the limiting space.

8. The self-centering clamp for welding the crossbeam tube and flange of a rotary tiller according to claim 1, characterized in that, It also includes a handwheel, which is fixedly connected to the first end of the double-threaded shaft by a cap nut.

9. The self-centering clamp for welding the crossbeam tube and flange of a rotary tiller according to claim 8, characterized in that, It also includes a spacer sleeve, which is fitted onto the first end of the double-threaded shaft and positioned between the handwheel and the force-transmitting bearing.

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