Erhu rod bending machine

Abstract

The application discloses a two-bending mechanism for a double-horn rod, and relates to the technical field of musical instrument processing. The inside of the frame is internally provided with the hydraulic mechanism, the upper end of the frame is provided with the first bending mechanism, the second bending mechanism and the controller, one side of the first bending mechanism is provided with the bending angle adjusting mechanism, and the controller is connected with the hydraulic mechanism. Through the arrangement of the frame, the controller, the first bending mechanism, the second bending mechanism, the bending angle adjusting mechanism and the hydraulic mechanism, the bending angle and the bending shape of the end of the rod can be automatically and accurately controlled, and the end of the rod can be bent once or twice.

Description

Technical Field

[0001] This invention relates to the field of musical instrument processing technology, and in particular to a bending machine for the erhu (a two-stringed bowed instrument). Background Technology

[0002] The erhu is a traditional Chinese bowed string instrument that originated in the Tang Dynasty. Originally called the huqin, it was renamed erhu in modern times and began to flourish. With a history of over a thousand years, the erhu is a highly distinctive solo instrument. A traditional erhu typically consists of a wooden soundbox, neck, strings, and bow. The end of the bow stick used with the erhu is generally curved with one or two bends (one arc), and the bending angle of the erhu's end is subject to strict requirements.

[0003] In existing technologies, the bending method of the erhu lever is to bend it by holding it with a hand clamp. This bending method cannot guarantee the bending angle and the shape of the bend. Moreover, for levers that are bent twice, the bending is more difficult and the bending angle and shape are more difficult to control. Summary of the Invention

[0004] The purpose of this invention is to provide an erhu tie rod bending machine to solve the above-mentioned technical problems.

[0005] The technical solution adopted in this invention is as follows:

[0006] A bending machine for the erhu (a two-stringed bowed instrument) includes a frame, a controller, a first bending mechanism, a second bending mechanism, a bending angle adjustment mechanism, and a hydraulic mechanism. The hydraulic mechanism is installed inside the frame, and the first bending mechanism, the second bending mechanism, and the controller are installed at the upper end of the frame. The bending angle adjustment mechanism is installed on one side of the first bending mechanism, and the controller is connected to the hydraulic mechanism.

[0007] The double bending mechanism includes an end plate, a first swing arm mechanism, a second swing arm, a third swing arm, a first drive shaft, a second drive shaft, a first pressure rod, a second pressure rod, a first main bend, and a second main bend. The two end plates are positioned opposite each other at the upper end of the frame. The first drive shaft, the first main bend, the second main bend, and the second drive shaft are sequentially arranged between the two end plates from top to bottom. The second swing arm and the third swing arm are arranged on one side of one end plate, and the first swing arm mechanism is arranged on one side of the other end plate. The first swing arm mechanism is connected to the hydraulic mechanism. One end of the second swing arm and the first swing arm mechanism are connected to both ends of the first drive shaft. One end of the third swing arm and the first swing arm mechanism are connected to both ends of the second drive shaft. The two ends of the first pressure rod are connected to the other end of the second swing arm mechanism and the first swing arm mechanism. The two ends of the second pressure rod are connected to the other end of the third swing arm and the first swing arm mechanism. The first pressure rod and the second pressure rod are located on both sides of the first main bend.

[0008] The outer wall of the first main bend is provided with a plurality of first arc-shaped grooves, and the outer wall of the second main bend is provided with a plurality of second arc-shaped grooves. The first arc-shaped grooves and the second arc-shaped grooves are directly opposite each other. The first pressure rod and the second pressure rod are each provided with a plurality of first annular grooves.

[0009] Preferably, the hydraulic mechanism includes a hydraulic station, a first cylinder, and a second cylinder. The piston rod of the first cylinder is connected to the first swing arm mechanism, and the piston rod of the second cylinder is connected to the bending mechanism. The first cylinder and the second cylinder are respectively connected to the hydraulic station.

[0010] As a further preferred embodiment, the system also includes a first limit sensor, a second limit sensor, a first limit stop, and a second limit stop. A first cylinder connector is provided on the piston rod of the first cylinder, and a second cylinder connector is provided on the piston rod of the second cylinder. The first limit sensor is located on both sides of the first cylinder, and the second limit sensor is located on both sides of the second cylinder. The first limit stop is located on the first cylinder connector, and the second limit stop is located on the second cylinder connector. The first limit stop can contact the first limit sensor, and the second limit stop can contact the second limit sensor. The hydraulic station, the first limit sensor, and the second limit sensor are respectively connected to the controller.

[0011] Preferably, the first swing arm mechanism includes a first connecting arm, a second connecting arm, and a third connecting arm. The middle part of the first connecting arm is connected to one end of the first drive shaft, one end of the first connecting arm is connected to one end of the first pressure rod, one end of the second connecting arm is hinged to the other end of the first connecting arm, the other end of the second connecting arm is hinged to one end of the third connecting arm and one end of the second pressure rod, the middle part of the third connecting arm is connected to one end of the second drive shaft, and the other end of the third connecting arm is connected to the hydraulic mechanism.

[0012] Preferably, the device further includes a first heating sleeve, a pressing mechanism, and a movable plate. The movable plate is movably disposed on the upper end of the two end plates. The lower end of the pressing mechanism passes through the movable plate and is connected to the first main bend. The first heating sleeve is disposed on both the first main bend and the second main bend.

[0013] As a further preferred embodiment, the clamping mechanism includes a threaded sleeve, a screw, a handle, and a bolt top block. The threaded sleeve passes through the movable plate, the screw is disposed inside the threaded sleeve, the upper end of the screw is provided with the handle, the upper end of the first main bend is provided with the bolt top block, the bolt top block is provided with a positioning hole, and the lower end of the screw extends into the positioning hole.

[0014] Preferably, the bending mechanism includes a connecting seat, a third drive shaft, a third main bend, a third pressure rod, a fourth swing arm, and a fifth swing arm. Two connecting seats are positioned opposite each other at the upper end of the frame, and the third main bend is positioned between the two connecting seats. The outer wall of the third main bend has several third arc-shaped grooves, and the lower end of the third main bend has the third drive shaft. The fourth swing arm is mounted on one connecting seat, and the fifth swing arm is mounted on the other connecting seat. The two ends of the third pressure rod are connected to one end of the fourth swing arm and one end of the fifth swing arm. The outer wall of the third pressure rod has several second annular grooves. The other end of the fourth swing arm is connected to the hydraulic mechanism, and the two ends of the third drive shaft are connected to the middle of the fourth swing arm and the other end of the fifth swing arm.

[0015] As a further preferred embodiment, the fourth swing arm is arranged in a "V" shape.

[0016] As a further preferred embodiment, the bending angle adjustment mechanism includes a fixed block, a handwheel, a threaded post, and a sliding block. The fixed block is located on one side of the third main bend, and the threaded post is threadedly connected to the fixed block. One end of the threaded post is connected to the handwheel, and the other end of the threaded post is connected to the sliding block. The sliding block faces the third main bend, and a plurality of first slots are provided on one side of the sliding block.

[0017] As a further preferred embodiment, the device also includes a base plate, with the lower end of the sliding block having the base plate attached. The base plate is connected to the frame, and the slider is slidably connected to the base plate.

[0018] The above technical solution has the following advantages or beneficial effects:

[0019] In this invention, by setting up a frame, a controller, a first bending mechanism, a second bending mechanism, a bending angle adjustment mechanism, and a hydraulic mechanism, the bending angle and bending shape of the end of the pull rod can be automatically and accurately controlled, and the end of the pull rod can be bent once or twice. Attached Figure Description

[0020] Figure 1 This is a front view of the erhu tie rod bending machine of the present invention;

[0021] Figure 2 This is a top view of the erhu tie rod bending machine of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of the erhu tie rod bending machine in this invention. Figure 1 ;

[0023] Figure 4 This is a schematic diagram of the structure of the erhu tie rod bending machine in this invention. Figure 2 ;

[0024] Figure 5 This is a schematic diagram of the two-bend mechanism in this invention. Figure 1 ;

[0025] Figure 6 This is a schematic diagram of the two-bend mechanism in this invention. Figure 2 ;

[0026] Figure 7 This is a schematic diagram of the bending mechanism in this invention. Figure 1 ;

[0027] Figure 8 This is a schematic diagram of the bending mechanism in this invention. Figure 2 ;

[0028] Figure 9 This is a schematic diagram of the bending angle adjustment mechanism in this invention.

[0029] In the diagram: 1. Frame; 2. Controller; 3. First bending mechanism; 301. Connecting seat; 302. Third drive shaft; 303. Third main bend; 304. Third pressure rod; 305. Fourth swing arm; 306. Fifth swing arm; 4. Second bending mechanism; 401. End plate; 402. First swing arm mechanism; 403. Second swing arm; 404. Third swing arm; 405. First drive shaft; 406. Second drive shaft; 407. First pressure rod; 408. Second pressure rod; 409. First main bend; 410. Second main bend; 411. First connecting arm; 412. Second connecting arm; 413. Third connecting arm; 414. First heating tube sleeve 415. Clamping mechanism; 416. Moving plate; 417. Threaded sleeve; 418. Screw; 419. Handle; 420. Bolt top block; 5. Bending angle adjustment mechanism; 501. Fixing block; 502. Handwheel; 503. Threaded column; 504. Sliding block; 505. Base plate; 506. First slot; 507. Second slot; 6. Hydraulic mechanism; 601. Hydraulic station; 602. First cylinder; 603. Second cylinder; 604. First limit sensor; 605. Second limit sensor; 606. First limit stop; 607. Second limit stop; 608. First cylinder connector; 609. Second cylinder connector. Detailed Implementation

[0030] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In the description of this invention, it should be noted that terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, terms such as "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] Figure 1 This is a front view of the erhu tie rod bending machine of the present invention; Figure 2 This is a top view of the erhu tie rod bending machine of the present invention; Figure 3 This is a schematic diagram of the structure of the erhu tie rod bending machine in this invention. Figure 1 ; Figure 4 This is a schematic diagram of the structure of the erhu tie rod bending machine in this invention. Figure 2 ; Figure 5 This is a schematic diagram of the two-bend mechanism in this invention. Figure 1 ; Figure 6 This is a schematic diagram of the two-bend mechanism in this invention. Figure 2 ; Figure 7 This is a schematic diagram of the bending mechanism in this invention. Figure 1 ; Figure 8 This is a schematic diagram of the bending mechanism in this invention. Figure 2 ; Figure 9 This is a schematic diagram of the bending angle adjustment mechanism in this invention. Please refer to [link / reference]. Figures 1 to 9 The diagram illustrates a preferred embodiment of an erhu (a two-stringed bowed instrument) bending machine, comprising a frame 1, a controller 2, a primary bending mechanism 3, a secondary bending mechanism 4, a bending angle adjustment mechanism 5, and a hydraulic mechanism 6. The hydraulic mechanism 6 is housed inside the frame 1. The primary bending mechanism 3, the secondary bending mechanism 4, and the controller 2 are located at the upper end of the frame 1. The bending angle adjustment mechanism 5 is located on one side of the primary bending mechanism 3. The controller 2 is connected to the hydraulic mechanism 6. In this embodiment, see [reference needed]. Figure 3 As shown, the controller 2 can be a PLC controller 2, which is used to control the hydraulic mechanism 6, so that the hydraulic mechanism 6 can drive the first bending mechanism 3 and the second bending mechanism 4 to perform the bending action.

[0034] The controller 2 controls the hydraulic mechanism 6, which in turn controls the first bending mechanism 3 and the second bending mechanism 4 to automatically bend the rod. No manual operation is required, which can realize the rapid bending of the rod end. The bending angle and shape can be controlled, which can improve work efficiency.

[0035] The double-bending mechanism 4 includes an end plate 401, a first swing arm mechanism 402, a second swing arm 403, a third swing arm 404, a first drive shaft 405, a second drive shaft 406, a first pressure rod 407, a second pressure rod 408, a first main bend 409, and a second main bend 410. The two end plates 401 are positioned opposite each other at the upper end of the frame 1. Between the two end plates 401, from top to bottom, are sequentially arranged the first drive shaft 405, the first main bend 409, the second main bend 410, and the second drive shaft 406. The second swing arm 403 and the third swing arm 404 are located on one side of one end plate 401, while the first swing arm mechanism 402 is located on one side of the other end plate 401. The first swing arm mechanism 402 is connected to the hydraulic mechanism 6. One end of the second swing arm 403 and both ends of the first swing arm mechanism 402 are connected to the first drive shaft 405. One end of the third swing arm 404 and both ends of the first swing arm mechanism 402 are connected to the second drive shaft 406. Both ends of the first pressure rod 407 are connected to the other end of the second swing arm 403 mechanism and the first swing arm mechanism 402. Both ends of the second pressure rod 408 are connected to the other end of the third swing arm 404 and the first swing arm mechanism 402. The first pressure rod 407 and the second pressure rod 408 are located on both sides of the first main bend 409. In this embodiment, the lower ends of the two end plates 401 are fixed to the upper end of the frame 1 by bolts. Both ends of the first drive shaft 405 and the second drive shaft 406 pass through the two end plates 401 respectively. The second swing arm 403 is fixedly connected to the first drive shaft 405, and the third swing arm 404 is fixedly connected to the second drive shaft 406. The two ends of the first pressure rod 407 are rotatably connected to the first swing arm mechanism 402 and the second swing arm 403. The second pressure rod 408 is rotatably connected to the first swing arm mechanism 402 and the third swing arm 404. The first swing arm mechanism 402 can be connected to the piston rod of the first oil cylinder 602. The controller 2 controls the hydraulic station 601, so that the hydraulic station 601 controls the first oil cylinder 602 to drive the first swing arm mechanism 402 to rotate. The first swing arm mechanism 402 can drive the first drive shaft 405 and the second drive shaft 406 to rotate. At the same time, the second swing arm 403 and the third swing arm 404 follow the rotation, thereby controlling the first pressure rod 407 and the second pressure rod 408 to swing, thereby pressing down on the pull rod and bending the pull rod.

[0036] The outer wall of the first main bend 409 is provided with several first arc-shaped grooves, and the outer wall of the second main bend 410 is provided with several second arc-shaped grooves. The first arc-shaped grooves and the second arc-shaped grooves are directly opposite each other. The first pressure rod 407 and the second pressure rod 408 are each provided with several first annular grooves. In use, the end of the pull rod is inserted from the upper side of the first pressure rod 407 into the space between the first main bend 409 and the second main bend 410, and then extends from the lower side of the second pressure rod 408. At this time, the outer wall of the pull rod abuts against the inner walls of the first arc-shaped groove, the second arc-shaped groove, and the first annular groove. Then, the hydraulic station 601 controls the first oil cylinder 602 to drive the first swing arm mechanism 402 to rotate, which ultimately drives the second pressure rod 408 to press down, while the first pressure rod 407 pushes the pull rod upward. With the limiting effect of the first main bend 409 and the second main bend 410, the pull rod is bent. By controlling the swing angle of the first swing arm mechanism 402, the bending angle of the pull rod is controlled. Since both the first main bend 409 and the second main bend 410 in this embodiment are arc-shaped plate structures, the parts that can bend the rod are all arc-shaped. The double-bending mechanism 4 in this embodiment makes the bending shape of the rod resemble an S-shape.

[0037] Furthermore, in a preferred embodiment, the hydraulic mechanism 6 includes a hydraulic station 601, a first cylinder 602, and a second cylinder 603. The piston rod of the first cylinder 602 is connected to the first swing arm mechanism 402, and the piston rod of the second cylinder 603 is connected to a bending mechanism 3. The first cylinder 602 and the second cylinder 603 are respectively connected to the hydraulic station 601. The hydraulic station 601 provides power to the first cylinder 602 and the second cylinder 603, enabling the piston rods of the first cylinder 602 and the second cylinder 603 to extend and retract.

[0038] Furthermore, as a preferred embodiment, it also includes a first limit sensor 604, a second limit sensor 605, a first limit baffle 606, and a second limit baffle 607. A first cylinder connector 608 is provided on the piston rod of the first cylinder 602, and a second cylinder connector 609 is provided on the piston rod of the second cylinder 603. The first limit sensor 604 is located on both sides of the first cylinder 602, and the second limit sensor 605 is located on both sides of the second cylinder 603. The first limit baffle 606 is located on the first cylinder connector 608, and the second limit baffle 607 is located on the second cylinder connector 609. The first limit baffle 606 can contact the first limit sensor 604, and the second limit baffle 607 can contact the second limit sensor 605. The hydraulic station 601, the first limit sensor 604, and the second limit sensor 605 are respectively connected to the controller 2. By setting the first limit baffle 606 and the two first limit sensors 604, the stroke of the piston rod of the first cylinder 602 can be limited. By setting the second limit baffle 607 and the second limit sensor 605, the stroke of the piston rod of the second cylinder 603 can be limited. The first limit sensors 604 and the second limit sensors 605 are respectively connected to the controller 2. When the first limit sensors 604 and the second limit sensors 605 detect the first limit baffle 606 and the second limit baffle 607, the controller 2 can automatically control the hydraulic station 601, so that the hydraulic station 601 controls the first cylinder 602 or the second cylinder 603 to stop working.

[0039] Furthermore, as a preferred embodiment, the first swing arm mechanism 402 includes a first connecting arm 411, a second connecting arm 412, and a third connecting arm 413. The middle part of the first connecting arm 411 is connected to one end of the first drive shaft 405, and one end of the first connecting arm 411 is connected to one end of the first pressure rod 407. One end of the second connecting arm 412 is hinged to the other end of the first connecting arm 411, and the other end of the second connecting arm 412 is hinged to one end of the third connecting arm 413 and one end of the second pressure rod 408. The middle part of the third connecting arm 413 is connected to one end of the second drive shaft 406, and the other end of the third connecting arm 413 is connected to the hydraulic mechanism 6. The first connecting arm 411 is rotatably connected to the first pressure rod 407, and the second connecting arm 412 is rotatably connected to the first connecting arm 411, the third connecting arm 413, and the second pressure rod 408. This allows the first pressure rod 407 and the second pressure rod 408 to rotate. During the process of pressing down the pull rod, the first pressure rod 407 and the second pressure rod 408 can rotate, reducing the contact friction with the pull rod, protecting the surface of the pull rod, and facilitating the bending of the pull rod.

[0040] Furthermore, as a preferred embodiment, it also includes a first heating sleeve 414, a pressing mechanism 415, and a moving plate 416. The moving plate 416 is movably disposed on the upper end of both end plates 401. The lower end of the pressing mechanism 415 passes through the moving plate 416 and is connected to the first main bend 409. The first heating sleeve 414 is disposed on both the first main bend 409 and the second main bend 410. The first heating sleeve 414 can be connected to the controller 2, and the controller 2 controls the first heating sleeve 414 to heat the first main bend 409 and the second main bend 410, so that the first main bend 409 and the second main bend 410 can heat the tie rod, which is more conducive to the bending of the tie rod. In this embodiment, both ends of the first main bend 409 and the second main bend 410 are connected to the two end plates 401.

[0041] Furthermore, as a preferred embodiment, the clamping mechanism 415 includes a threaded sleeve 417, a screw 418, a handle 419, and a bolt top block 420. The threaded sleeve 417 penetrates the movable plate 416, and the screw 418 is disposed within the threaded sleeve 417. The upper end of the screw 418 is provided with the handle 419, and the upper end of the first main bend 409 is provided with the bolt top block 420. The bolt top block 420 has a positioning hole, and the lower end of the screw 418 extends into the positioning hole. By controlling the rotation of the screw 418 through the handle 419, the screw 418 can extend into the positioning hole, thereby pressing down on the first main bend 409, allowing the first main bend 409 to press against the pull rod, thus making the structure more stable. The bolt top block 420 abuts against the upper end of the first main bend 409 and can be separated from it. The threaded sleeve 417 is fixedly connected to the movable plate 416. The connecting plate has slotted holes at both ends, and the upper end of the end plate 401 has bolt holes. Bolts pass through the slotted holes and connect to the bolt holes. When the bolts are tightened, the movable plate 416 can be fixed. When the bolts are loosened, the movable plate 416 can move for easy position adjustment. When position adjustment is needed, the bolt top block 420 can be moved to the designated position first, and then the movable plate 416 can be moved to drive the threaded sleeve 417 and the screw 418 to move, so that the lower end of the screw 418 can extend into the positioning hole on the bolt top block 420. In this embodiment, see... Figure 6 As shown, the third connecting arm 413 is arranged in a "V" shape. The third connecting arm 413 can be replaced with models with different included angles in the middle. When the piston rod stroke of the first oil cylinder 602 is fixed, the rotation amplitude of the first pressure rod 407 and the second pressure rod 408 can be changed, thereby controlling the bending angle of the tie rod.

[0042] Furthermore, as a preferred embodiment, a bending mechanism 3 includes a connecting seat 301, a third drive shaft 302, a third main bending pipe 303, a third pressure rod 304, a fourth swing arm 305, and a fifth swing arm 306. Two connecting seats 301 are arranged opposite each other at the upper end of the frame 1. The third main bending pipe 303 is arranged between the two connecting seats 301. The outer wall of the third main bending pipe 303 is provided with several third arc-shaped grooves. The lower end of the third main bending pipe 303 is provided with the third drive shaft 302. The fourth swing arm 305 is arranged on one connecting seat 301, and the fifth swing arm 306 is arranged on the other connecting seat 301. The two ends of the third pressure rod 304 are connected to one end of the fourth swing arm 305 and one end of the fifth swing arm 306. The outer wall of the third pressure rod 304 is provided with several second annular grooves. The other end of the fourth swing arm 305 is connected to the hydraulic mechanism 6. The two ends of the third drive shaft 302 are connected to the middle part of the fourth swing arm 305 and the other end of the fifth swing arm 306. See Figure 7 and Figure 8 As shown, the connecting seat 301 can be connected to the upper end of the frame 1 by bolts. The third drive shaft 302 passes through two connecting seats 301 and is rotatably connected to the connecting seats 301. The fourth swing arm 305 and the fifth swing arm 306 are fixedly connected to the third drive shaft 302. The other end of the fourth swing arm 305 is used to connect to the piston rod of the second oil cylinder 603. The second oil cylinder 603 drives the fourth swing arm 305 to rotate, thereby driving the third drive shaft 302 to rotate. The third drive shaft 302 drives the fifth swing arm 306 to rotate, which in turn drives the third pressure rod 304 to rotate. A second heating sleeve is provided on the bottom wall of the third main bend pipe 303.

[0043] When the tie rod needs to be bent once, the end of the tie rod can be passed through the lower side of the third pressure rod 304 and then through the upper side of the third main bend 303, so that the outer wall of the tie rod abuts against the inner wall of the third arc groove and the inner wall of the second annular groove. Then, the hydraulic station 601 controls the second oil cylinder 603 to drive the fourth swing arm 305 to rotate, which finally drives the third pressure rod 304 to press down the tie rod, and cooperates with the third main bend 303 to realize the bending of the tie rod once.

[0044] Among them, the first cylinder connector 608 on the first cylinder 602 is used to connect the third swing arm 404, and the second cylinder connector 609 on the second cylinder 603 is used to connect the fourth swing arm 305.

[0045] Furthermore, as a preferred embodiment, the fourth swing arm 305 is arranged in a "V" shape, and the fourth swing arm 305 can be disassembled and replaced, and different models with different included angles in the middle can be replaced.

[0046] Furthermore, as a preferred embodiment, the bending angle adjustment mechanism 5 includes a fixed block 501, a handwheel 502, a threaded post 503, and a sliding block 504. The fixed block 501 is located on one side of the third main bend 303. The threaded post 503 is threadedly connected to the fixed block 501. One end of the threaded post 503 is connected to the handwheel 502, and the other end of the threaded post 503 is connected to the sliding block 504. The sliding block 504 faces the third main bend 303, and a plurality of first slots 506 are provided on one side of the sliding block 504. The lower end of the sliding block 504 is provided with a base plate 505, which is connected to the frame 1. The slider is slidably connected to the base plate 505. The base plate 505 is L-shaped and has several second slots 507. The first slot 506 and the second slot 507 are opposite each other to form a positioning slot. The end of the pull rod can be inserted into the positioning slot. The diameter of the positioning slot can be adjusted. By rotating the handwheel 502, the threaded column 503 is rotated. The threaded column 503 moves forward and pushes the sliding block 504 to slide on the base plate 505. At this time, the sliding block 504 will push the end of the pull rod. During the bending process of the pull rod, the bending angle of the pull rod can be finely adjusted. For example, when the threaded post 503 pushes the sliding block 504 to move, the sliding block 504 will push the pull rod, which will increase the bending angle of the pull rod. When the threaded post 503 retracts, the sliding block 504 will automatically retract under the push of the end of the pull rod, at which time the bending angle of the end of the pull rod will become smaller.

[0047] The sliding block 504 has a strip groove, and the base plate 505 has a bolt hole. The bolt passes through the strip groove and connects to the bolt hole. Tightening the bolt can fix the position of the sliding block 504. When the bolt is loosened, the position of the sliding block 504 can be moved.

[0048] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A bending machine for the tie rod of an erhu (a two-stringed bowed instrument), characterized in that, The device includes a frame, a controller, a first bending mechanism, a second bending mechanism, a bending angle adjustment mechanism, and a hydraulic mechanism. The hydraulic mechanism is installed inside the frame. The first bending mechanism, the second bending mechanism, and the controller are installed at the upper end of the frame. The bending angle adjustment mechanism is installed on one side of the first bending mechanism. The controller is connected to the hydraulic mechanism. The double bending mechanism includes an end plate, a first swing arm mechanism, a second swing arm, a third swing arm, a first drive shaft, a second drive shaft, a first pressure rod, a second pressure rod, a first main bend, and a second main bend. The two end plates are positioned opposite each other at the upper end of the frame. The first drive shaft, the first main bend, the second main bend, and the second drive shaft are arranged sequentially from top to bottom between the two end plates. The second swing arm and the third swing arm are arranged on one side of one end plate, and the first swing arm mechanism is arranged on one side of the other end plate. The first swing arm mechanism is connected to the hydraulic mechanism. One end of the second swing arm and the first swing arm mechanism are connected to both ends of the first drive shaft. One end of the third swing arm and the first swing arm mechanism are connected to both ends of the second drive shaft. The two ends of the first pressure rod are connected to the other end of the second swing arm and the first swing arm mechanism. The two ends of the second pressure rod are connected to the other end of the third swing arm and the first swing arm mechanism. The first pressure rod and the second pressure rod are located on both sides of the first main bend. The outer wall of the first main bend is provided with a plurality of first arc-shaped grooves, and the outer wall of the second main bend is provided with a plurality of second arc-shaped grooves. The first arc-shaped grooves and the second arc-shaped grooves are directly opposite each other. The first pressure rod and the second pressure rod are each provided with a plurality of first annular grooves. The first swing arm mechanism includes a first connecting arm, a second connecting arm, and a third connecting arm. The middle part of the first connecting arm is connected to one end of the first drive shaft, and one end of the first connecting arm is connected to one end of the first pressure rod. One end of the second connecting arm is hinged to the other end of the first connecting arm, and the other end of the second connecting arm is hinged to one end of the third connecting arm and one end of the second pressure rod. The middle part of the third connecting arm is connected to one end of the second drive shaft, and the other end of the third connecting arm is connected to the hydraulic mechanism.

2. The erhu tie rod bending machine as described in claim 1, characterized in that, The hydraulic mechanism includes a hydraulic station, a first cylinder, and a second cylinder. The piston rod of the first cylinder is connected to the first swing arm mechanism, and the piston rod of the second cylinder is connected to the bending mechanism. The first cylinder and the second cylinder are respectively connected to the hydraulic station.

3. The erhu tie rod bending machine as described in claim 2, characterized in that, It also includes a first limit sensor, a second limit sensor, a first limit stop, and a second limit stop. A first cylinder connector is provided on the piston rod of the first cylinder, and a second cylinder connector is provided on the piston rod of the second cylinder. The first limit sensor is located on both sides of the first cylinder, and the second limit sensor is located on both sides of the second cylinder. The first limit stop is located on the first cylinder connector, and the second limit stop is located on the second cylinder connector. The first limit stop can contact the first limit sensor, and the second limit stop can contact the second limit sensor. The hydraulic station, the first limit sensor, and the second limit sensor are respectively connected to the controller.

4. The erhu tie rod bending machine as described in claim 1, characterized in that, It also includes a first heating sleeve, a pressing mechanism and a moving plate. The moving plate is movably disposed on the upper end of the two end plates. The lower end of the pressing mechanism passes through the moving plate and is connected to the first main bend. The first heating sleeve is disposed on both the first main bend and the second main bend.

5. The erhu tie rod bending machine as described in claim 4, characterized in that, The clamping mechanism includes a threaded sleeve, a screw, a handle, and a bolt top block. The threaded sleeve passes through the movable plate, the screw is located inside the threaded sleeve, the upper end of the screw is provided with the handle, the upper end of the first main bend is provided with the bolt top block, the bolt top block has a positioning hole, and the lower end of the screw extends into the positioning hole.

6. The erhu tie rod bending machine as described in claim 1, characterized in that, The bending mechanism includes a connecting seat, a third drive shaft, a third main bend, a third pressure rod, a fourth swing arm, and a fifth swing arm. Two connecting seats are positioned opposite each other at the upper end of the frame, and the third main bend is positioned between the two connecting seats. The outer wall of the third main bend has several third arc-shaped grooves. The lower end of the third main bend is provided with the third drive shaft. The fourth swing arm is provided on one connecting seat, and the fifth swing arm is provided on the other connecting seat. The two ends of the third pressure rod are connected to one end of the fourth swing arm and one end of the fifth swing arm. The outer wall of the third pressure rod has several second annular grooves. The other end of the fourth swing arm is connected to the hydraulic mechanism. The two ends of the third drive shaft are connected to the middle part of the fourth swing arm and the other end of the fifth swing arm.

7. The erhu tie rod bending machine as described in claim 6, characterized in that, The fourth swing arm is arranged in a "V" shape.

8. The erhu tie rod bending machine as described in claim 6, characterized in that, The bending angle adjustment mechanism includes a fixed block, a handwheel, a threaded post, and a sliding block. The fixed block is located on one side of the third main bend. The threaded post is threadedly connected to the fixed block. One end of the threaded post is connected to the handwheel, and the other end of the threaded post is connected to the sliding block. The sliding block faces the third main bend, and a plurality of first slots are provided on one side of the sliding block.

9. The erhu tie rod bending machine as described in claim 8, characterized in that, It also includes a base plate, the lower end of which is provided with the base plate, the base plate being connected to the frame, and the sliding block being slidably connected to the base plate.

Images