A press bending forming apparatus for a vehicle leaf spring
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANDONG SHANTAN AUTO PARTS CO LTD
- Filing Date
- 2025-11-14
- Publication Date
- 2026-07-21
Smart Images

Figure CN121131476B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of leaf spring manufacturing technology, specifically to an automotive leaf spring bending and forming equipment. Background Technology
[0002] Automotive leaf springs are traditional elastic elements in automotive suspension systems. They consist of multiple alloy spring steel plates of unequal length stacked together to form an elastic beam of approximately equal strength. Using alloy materials such as silicon-manganese steel, the metal properties are optimized to balance hardenability and crack resistance. This component transmits forces and torques in all directions through longitudinal installation, utilizing the inter-plate friction of the multi-plate stacked structure to achieve vibration damping. It also functions as a buffer, guide, and elastic support. The manufacturing process includes more than ten steps such as blanking, earing, quenching, and shot peening. Its core characteristic is that it can withstand vertical loads with unidirectional bending stress. The product has the advantages of simple structure, high reliability, and low cost. It is suitable for non-independent suspension systems and can replace independent guide devices and shock absorbers. Its service life is affected by the heat treatment process, shot peening quality, and usage conditions. When purchasing, it is necessary to focus on checking quality indicators such as surface rust prevention and assembly markings.
[0003] In the production process of leaf springs, the leaf springs need to be bent into shape. After being heated at high temperature, the leaf springs are conveyed to the quenching fixture by a conveyor belt, pressed into the ideal arc, and then immersed in cold oil. However, when moving the leaf springs from the conveyor belt to the fixture, manual operation is required. The operator puts the heated leaf springs from the conveyor belt into the fixture, bends them, and then moves the leaf springs back to the conveyor belt. This is labor-intensive and poses safety hazards. In order to achieve the purpose of automatically moving the leaf springs, an automotive leaf spring bending forming equipment is provided. Summary of the Invention
[0004] The purpose of this invention is to provide an automotive leaf spring bending and forming device in order to achieve automatic movement of leaf springs.
[0005] To achieve the above objectives, the present invention provides the following technical solution: an automotive leaf spring bending forming device, comprising a cold oil tank, a conveyor belt installed at one end of the cold oil tank, a mounting frame fixedly connected to the top of the cold oil tank, a first hydraulic cylinder installed at the top of the mounting frame, a movable seat connected to the output end of the first hydraulic cylinder, a mounting plate fixedly connected to the outer wall of the movable seat, a second hydraulic cylinder installed at the top of the mounting plate, an extrusion seat connected to the output end of the second hydraulic cylinder, a plurality of upper pressure rods arranged in an arc shape fixedly connected to the bottom end of the extrusion seat, a plurality of lower pressure rods fixedly connected to the outer wall of the movable seat below the upper pressure rods, the plurality of lower pressure rods being arranged in an arc shape, the leaf spring being displaced by a displacement mechanism, and the leaf spring being prevented from slipping off the lower pressure rods by a limiting mechanism; The displacement mechanism includes a vertical plate, which is fixedly connected to the end of the conveyor belt away from the movable seat. A groove is provided at one end of the vertical plate, and a third hydraulic cylinder is installed at the other end of the vertical plate. A push plate is connected to the output end of the third hydraulic cylinder, and a connecting rod is fixedly connected to one end of the push plate.
[0006] As a further embodiment of the present invention: the displacement mechanism further includes a locking block, the locking block being slidably connected to the interior of the connecting rod and extending out of the connecting rod, a first spring being connected between the locking block and the connecting rod, a displacement rod being slidably connected to the interior of the connecting rod on one side of the locking block, the displacement rod extending out of the push plate, a push frame being slidably connected to the interior of the movable seat, the push frame being located between the upper pressure rod and the lower pressure rod, a displacement plate being fixedly connected to one end of the push frame, a second spring being connected between the displacement plate and the movable seat, a connecting groove being provided at the other end of the push frame, and a locking groove being provided at the bottom of the inner wall of the connecting groove.
[0007] As a further embodiment of the present invention: the limiting mechanism includes a vertical rod, which is symmetrically and fixedly connected to both sides of the extrusion seat. The outer wall of the movable seat is fixedly connected to a limiting seat below the pressing rod. The outer wall of the limiting seat has a limiting groove. A baffle is slidably connected to the inner wall of the limiting groove. A limiting rod penetrating the baffle is fixedly connected to the inner wall of the limiting groove. Connecting rods are symmetrically and rotatably connected to both sides of the baffle. A horizontal rod is rotatably connected to one end of the connecting rod. The horizontal rod is slidably connected to the limiting seat. A sliding plate is fixedly connected to one end of the horizontal rod. The sliding plate is slidably connected to the inside of the limiting seat and extends out of the limiting seat.
[0008] As a further embodiment of the present invention: the outer wall of one end of the connecting rod is in contact with the inner wall of the connecting groove, and the outer wall of the bottom end of the card block is in contact with the inner wall of the card groove.
[0009] As a further embodiment of the present invention: the end of the card block extending from the connecting rod is provided with a first inclined surface, the first inclined surface facing away from the end of the push plate.
[0010] As a further embodiment of the present invention: the outer wall of the push plate is in contact with the inner wall of the groove.
[0011] As a further embodiment of the present invention: a second inclined surface is provided on one side of the outer wall of the card block, and the displacement rod is in contact with the second inclined surface.
[0012] As a further embodiment of the present invention: the top of the skateboard is provided with a third inclined surface, and the bottom end of the vertical rod is located above the third inclined surface.
[0013] As a further embodiment of the present invention: both ends of the connecting rod are connected to the crossbar and the baffle via rotating shafts.
[0014] As a further embodiment of the present invention: the outer wall of the baffle is in contact with the inner wall of the limiting groove, and a limiting hole is formed on the outer wall of the baffle, and the inner wall of the limiting hole is in contact with the outer wall of the limiting rod.
[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. By setting a displacement mechanism, the push plate is pushed to contact the leaf spring, and the leaf spring is pushed to the lower pressure rod. After completion, the push plate is pushed into the groove for reset operation. After the leaf spring is bent, it enters the cold oil tank. After completion, the movable seat moves upward, and the push plate moves to drive the connecting rod to move. The connecting rod moves and inserts into the connecting groove to fix the connecting rod and the push frame. After completion, the push plate moves in the opposite direction, and the push frame moves to push the leaf spring onto the conveyor belt, which facilitates automatic displacement of the leaf spring. The leaf spring is automatically moved from the conveyor belt to the bending equipment, and then the bent leaf spring is moved onto the conveyor belt for displacement operation.
[0016] 2. By setting a limiting mechanism, the pressing seat moves downward, which in turn moves the vertical rod. The vertical rod then contacts the sliding plate, pushing the sliding plate to move. The sliding plate's movement causes the horizontal rod to move, which in turn moves the baffle via a connecting rod. The baffle moves upward, blocking one end of the lower pressing rod to prevent the leaf spring from slipping off the lower pressing rod due to vibration when the upper pressing rod is not in contact with the leaf spring, thus affecting the bending operation of the leaf spring. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the mounting bracket of the present invention; Figure 3 This is a schematic diagram of the structure of the movable seat of the present invention; Figure 4 This is a cross-sectional view of the movable seat of the present invention; Figure 5 This is a cross-sectional view of the pusher frame of the present invention; Figure 6 This is a cross-sectional view of the vertical plate of the present invention; Figure 7 This is a cross-sectional view of the push plate of the present invention; Figure 8 This is a schematic diagram of the structure of the limiting seat of the present invention; Figure 9 This is a cross-sectional view of the limiting seat of the present invention.
[0018] In the diagram: 1. Cold oil tank; 2. Conveyor belt; 3. Mounting frame; 4. First hydraulic cylinder; 5. Movable seat; 6. Mounting plate; 7. Second hydraulic cylinder; 8. Displacement mechanism; 801. Vertical plate; 802. Groove; 803. Third hydraulic cylinder; 804. Push plate; 805. Connecting rod; 806. Locking block; 807. First spring; 808. Displacement rod; 809. Pushing frame; 810. Displacement plate; 811. Second spring; 812. Connecting groove; 813. Locking groove; 9. Limiting mechanism; 901. Vertical rod; 902. Limiting seat; 903. Limiting groove; 904. Limiting rod; 905. Baffle; 906. Connecting rod; 907. Horizontal rod; 908. Slide plate; 10. Extrusion seat; 11. Upper pressure rod; 12. Lower pressure rod. Detailed Implementation
[0019] 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 some embodiments of the present invention, and not all embodiments. 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.
[0020] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and 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, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," and "set up" 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 communication 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. The following describes embodiments of the invention based on its overall structure.
[0021] Please see Figures 1 to 9In this embodiment of the invention, an automotive leaf spring bending forming device includes a cold oil tank 1, a conveyor belt 2 installed at one end of the cold oil tank 1, a mounting frame 3 fixedly connected to the top of the cold oil tank 1, a first hydraulic cylinder 4 installed at the top of the mounting frame 3, a movable seat 5 connected to the output end of the first hydraulic cylinder 4, a mounting plate 6 fixedly connected to the outer wall of the movable seat 5, a second hydraulic cylinder 7 installed at the top of the mounting plate 6, a pressing seat 10 connected to the output end of the second hydraulic cylinder 7, a plurality of arc-shaped upper pressing rods 11 fixedly connected to the bottom end of the pressing seat 10, a plurality of lower pressing rods 12 fixedly connected to the outer wall of the movable seat 5 below the upper pressing rods 11, the plurality of lower pressing rods 12 being arc-shaped, the leaf spring being displaced by a displacement mechanism 8, and the leaf spring being prevented from slipping off the lower pressing rods 12 by a limiting mechanism 9.
[0022] In this embodiment: the heated leaf spring moves onto the lower pressure rod 12, the second hydraulic cylinder 7 is activated, the second hydraulic cylinder 7 rotates and drives the compression seat 10 to move, the compression seat 10 moves and drives the upper pressure rod 11 to move, the upper pressure rod 11 moves and together with the lower pressure rod 12 bends the leaf spring; the first hydraulic cylinder 4 is activated, the first hydraulic cylinder 4 rotates and drives the movable seat 5 to move, the movable seat 5 moves and drives the leaf spring to move into the cold oil bath 1 through the lower pressure rod 12. After being immersed in cold oil, the high temperature and cold oil collide violently, giving the leaf spring excellent hardness and toughness, easily resisting heavy loads and bumps, and protecting it in harsh road conditions.
[0023] Please refer to this carefully. Figures 2 to 7 The displacement mechanism 8 includes a vertical plate 801, which is fixedly connected to the end of the conveyor belt 2 away from the movable seat 5. A groove 802 is provided at one end of the vertical plate 801, and a third hydraulic cylinder 803 is installed at the other end of the vertical plate 801. A push plate 804 is connected to the output end of the third hydraulic cylinder 803, and a connecting rod 805 is fixedly connected to one end of the push plate 804. The displacement mechanism 8 also includes a locking block 806, which is slidably connected to the inside of the connecting rod 805 and extends out of the connecting rod 805. The locking block 806 and the connecting rod 805 are connected... There is a first spring 807. Inside the connecting rod 805, a displacement rod 808 is slidably connected to one side of the locking block 806. The displacement rod 808 extends into a push plate 804. Inside the movable seat 5, a push frame 809 is slidably connected. The push frame 809 is located between the upper pressure rod 11 and the lower pressure rod 12. One end of the push frame 809 is fixedly connected to a displacement plate 810. A second spring 811 is connected between the displacement plate 810 and the movable seat 5. The other end of the push frame 809 is provided with a connecting groove 812. The bottom of the inner wall of the connecting groove 812 is provided with a locking groove 813.
[0024] In this embodiment: when bending the leaf spring, the heated leaf spring is moved to one end of the lower pressure rod 12 via the conveyor belt 2. At this time, the top of the highest vertical lower pressure rod 12 is flush with the top of the conveyor belt 2. The third hydraulic cylinder 803 is activated, and the operation of the third hydraulic cylinder 803 drives the push plate 804 to move. The push plate 804 moves out of the groove 802 and comes into contact with the leaf spring, pushing the heated leaf spring to move. The leaf spring moves onto the lower pressure rod 12. After completion, the push plate 804 moves into the groove 802 for reset operation. Then, the upper pressure rod 11 moves downward, bending the leaf spring together with the lower pressure rod 12. The leaf spring then moves into the cold oil bath 1. After completion, the movable seat 5 moves upward, aligning the top of the lowest vertical pressure rod 12 with the top of the conveyor belt 2. The upper pressure rod 11 moves away from the lower pressure rod 12, releasing the leaf spring. The third hydraulic cylinder 803 is then activated again, pushing the plate 804 to move, causing the connecting rod 805 to move as well. At this point, the connecting rod 805 is aligned with the connecting groove 812. When the connecting rod 805 moves and inserts into the connecting groove 812, the locking block 806 contacts the inner wall of the connecting groove 812. The locking block 806 is displaced by force and enters the connecting rod 805, compressing the first spring 807 until the locking block 806 contacts the slot 813. The locking block 806, under the elastic force of the first spring 807, engages and enters the slot 813, fixing the connecting rod 805 and the pusher frame 809. After completion, the pusher plate 804 moves in the opposite direction, and the pusher plate 804 passes through the connecting rod 805... The pusher 809 is displaced, which in turn causes the displacement plate 810 to move, compressing the second spring 811. The pusher 809 then contacts the leaf spring, pushing the bent leaf spring onto the conveyor belt 2. At this time, the pusher plate 804 moves into the groove 802, and the displacement rod 808 contacts the inner wall of the groove 802. The displacement rod 808 is subjected to force and displaces relative to the connecting rod 805. The displacement rod 808 pushes the locking block 806 to move, thus displacing the first spring 807. The compression causes the card block 806 to displace out of the card slot 813, thus removing the fixation between the connecting rod 805 and the push frame 809. The displacement plate 810 is reset by the elastic force of the second spring 811. The reset of the displacement plate 810 drives the push frame 809 to reset and displace. At this time, the leaf spring after bending can be displaced by the conveyor belt 2, which facilitates the automatic displacement of the leaf spring. The leaf spring is automatically moved from the conveyor belt 2 to the bending equipment, and then the bent leaf spring is moved to the conveyor belt 2 for displacement.
[0025] Please refer to this carefully. Figures 8 to 9The limiting mechanism 9 includes a vertical rod 901, which is symmetrically and fixedly connected to both sides of the extrusion seat 10. The outer wall of the movable seat 5 is fixedly connected to a limiting seat 902 below the pressing rod 12. A limiting groove 903 is opened on the outer wall of the limiting seat 902. A baffle 905 is slidably connected to the inner wall of the limiting groove 903. A limiting rod 904 that passes through the baffle 905 is fixedly connected to the inner wall of the limiting groove 903. A connecting rod 906 is symmetrically and rotatably connected to both sides of the baffle 905. A horizontal rod 907 is rotatably connected to one end of the connecting rod 906. The horizontal rod 907 is slidably connected to the limiting seat 902. A sliding plate 908 is fixedly connected to one end of the horizontal rod 907. The sliding plate 908 is slidably connected to the inside of the limiting seat 902 and extends out of the limiting seat 902.
[0026] In this embodiment: when bending the leaf spring, the compression seat 10 moves downward, causing the vertical rod 901 to move. The vertical rod 901 then contacts the sliding plate 908, pushing the sliding plate 908 to move. The sliding plate 908 then moves the horizontal rod 907, which in turn moves the baffle 905 via the connecting rod 906. The baffle 905 moves upward, blocking one end of the lower pressure rod 12 to prevent the leaf spring from slipping off one end of the lower pressure rod 12 when the upper pressure rod 11 is not in contact with the leaf spring. When releasing the leaf spring, the compression seat 10 moves the upper pressure rod 11 away from the lower pressure rod 12 until the vertical rod 901 separates from the sliding plate 908. The baffle 905 then moves downward under gravity to reset, removing the blockage on one end of the lower pressure rod 12.
[0027] Please refer to this carefully. Figures 2 to 7 One end of the connecting rod 805 is attached to the inner wall of the connecting groove 812, and the bottom end of the locking block 806 is attached to the inner wall of the locking groove 813. The locking block 806 extends out of the connecting rod 805 and is provided with a first inclined surface, which faces away from the push plate 804.
[0028] In this embodiment: the third hydraulic cylinder 803 operates to drive the push plate 804 to move, and the displacement of the push plate 804 drives the connecting rod 805 to move. At this time, the connecting rod 805 is aligned with the connecting groove 812. The connecting rod 805 moves and inserts into the connecting groove 812. The locking block 806 contacts the inner wall of the connecting groove 812. The locking block 806 is displaced by force and enters the connecting rod 805, which compresses the first spring 807 until the locking block 806 contacts the locking groove 813. The locking block 806 is locked into the locking groove 813 by the elastic force of the first spring 807, and the connecting rod 805 and the push frame 809 are fixed together.
[0029] Please refer to this carefully. Figures 2 to 7 The outer wall of the push plate 804 fits against the inner wall of the groove 802.
[0030] In this embodiment: the push plate 804 moves into the groove 802, the displacement rod 808 contacts the inner wall of the groove 802, and the displacement rod 808 is displaced relative to the connecting rod 805 under force.
[0031] Please refer to this carefully. Figures 2 to 7 A second inclined surface is provided on one side of the outer wall of the card block 806, and the displacement rod 808 is in contact with the second inclined surface.
[0032] In this embodiment: the displacement rod 808 moves to push the locking block 806 to move, causing compression on the first spring 807. The locking block 806 moves out of the locking groove 813, thus canceling the fixation between the connecting rod 805 and the push frame 809.
[0033] Please refer to this carefully. Figures 8 to 9 The top of the skateboard 908 has a third inclined surface, and the bottom of the vertical rod 901 is located above the third inclined surface.
[0034] In this embodiment: the extrusion seat 10 moves downward, and the displacement of the extrusion seat 10 causes the vertical rod 901 to move. The vertical rod 901 moves and contacts the sliding plate 908, pushing the sliding plate 908 to move.
[0035] Please refer to this carefully. Figures 8 to 9 Both ends of the connecting rod 906 are connected to the crossbar 907 and the baffle 905 via pivots.
[0036] In this embodiment: the displacement of the slide plate 908 causes the crossbar 907 to move, and the displacement of the crossbar 907 causes the baffle 905 to move through the connecting rod 906.
[0037] Please refer to this carefully. Figures 8 to 9 The outer wall of the baffle 905 contacts the inner wall of the limiting groove 903. A limiting hole is provided on the outer wall of the baffle 905, and the inner wall of the limiting hole fits against the outer wall of the limiting rod 904.
[0038] In this embodiment: the baffle 905 slides on the inner wall of the limiting groove 903, and the limiting rod 904 slides in the limiting hole to limit the displacement direction of the baffle 905.
[0039] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. An automotive leaf spring bending forming device, comprising a cold oil bath (1), characterized in that, A conveyor belt (2) is installed at one end of the cold oil tank (1). A mounting frame (3) is fixedly connected to the top of the cold oil tank (1). A first hydraulic cylinder (4) is installed at the top of the mounting frame (3). A movable seat (5) is connected to the output end of the first hydraulic cylinder (4). A mounting plate (6) is fixedly connected to the outer wall of the movable seat (5). A second hydraulic cylinder (7) is installed at the top of the mounting plate (6). A pressing seat (10) is connected to the output end of the second hydraulic cylinder (7). A plurality of upper pressing rods (11) are fixedly connected to the bottom end of the pressing seat (10). A plurality of lower pressing rods (12) are fixedly connected to the outer wall of the movable seat (5) below the upper pressing rods (11). The plurality of lower pressing rods (12) are arranged in an arc shape. The leaf spring is displaced by the displacement mechanism (8). The leaf spring is prevented from slipping off the lower pressing rods (12) by the limiting mechanism (9). The displacement mechanism (8) includes a vertical plate (801), which is fixedly connected to one end of the conveyor belt (2) away from the movable seat (5). A groove (802) is provided at one end of the vertical plate (801), and a third hydraulic cylinder (803) is installed at the other end of the vertical plate (801). A push plate (804) is connected to the output end of the third hydraulic cylinder (803), and a connecting rod (805) is fixedly connected to one end of the push plate (804). The displacement mechanism (8) further includes a locking block (806), which is slidably connected to the interior of the connecting rod (805) and extends out of the connecting rod (805). A first spring (807) is connected between the locking block (806) and the connecting rod (805). A displacement rod (808) is slidably connected to the interior of the connecting rod (805) on one side of the locking block (806). The displacement rod (808) extends out of the push plate (804). The movable seat (5) is internally slidably connected to a pusher frame (809), which is located between the upper pressure rod (11) and the lower pressure rod (12). One end of the pusher frame (809) is fixedly connected to a displacement plate (810), and a second spring (811) is connected between the displacement plate (810) and the movable seat (5). The other end of the pusher frame (809) is provided with a connecting groove (812), and the bottom of the inner wall of the connecting groove (812) is provided with a slot (813). The limiting mechanism (9) includes a vertical rod (901), which is symmetrically fixedly connected to both sides of the pressing seat (10). The outer wall of the movable seat (5) is fixedly connected to a limiting seat (902) below the pressing rod (12). A limiting groove (903) is formed on the outer wall of the limiting seat (902). A baffle (905) is slidably connected to the inner wall of the limiting groove (903). A through-hole is fixedly connected to the inner wall of the limiting groove (903). The baffle (905) has a limiting rod (904). The baffle (905) is symmetrically and rotatably connected to two sides by connecting rods (906). One end of the connecting rod (906) is rotatably connected to a crossbar (907). The crossbar (907) is slidably connected to the limiting seat (902). One end of the crossbar (907) is fixedly connected to a sliding plate (908). The sliding plate (908) is slidably connected to the inside of the limiting seat (902) and extends out of the limiting seat (902).
2. The automotive leaf spring bending forming equipment according to claim 1, characterized in that, One end of the connecting rod (805) is attached to the inner wall of the connecting groove (812), and the bottom end of the locking block (806) is attached to the inner wall of the locking groove (813).
3. The automotive leaf spring bending and forming equipment according to claim 1, characterized in that, The locking block (806) extends from one end of the connecting rod (805) and is provided with a first inclined surface, the first inclined surface facing away from the end of the push plate (804).
4. The automotive leaf spring bending and forming equipment according to claim 1, characterized in that, The outer wall of the push plate (804) is in contact with the inner wall of the groove (802).
5. The automotive leaf spring bending and forming equipment according to claim 1, characterized in that, The outer wall of one side of the card block (806) is provided with a second inclined surface, and the displacement rod (808) is in contact with the second inclined surface.
6. The automotive leaf spring bending and forming equipment according to claim 1, characterized in that, The top of the slide plate (908) is provided with a third inclined surface, and the bottom end of the vertical rod (901) is located above the third inclined surface.
7. The automotive leaf spring bending forming equipment according to claim 1, characterized in that, Both ends of the connecting rod (906) are connected to the crossbar (907) and the baffle (905) via pivots.
8. The automotive leaf spring bending and forming equipment according to claim 1, characterized in that, The outer wall of the baffle (905) is in contact with the inner wall of the limiting groove (903), and a limiting hole is provided on the outer wall of the baffle (905). The inner wall of the limiting hole is in contact with the outer wall of the limiting rod (904).