A tension spring for use in an automotive braking system

Abstract

The application relates to the field of automobile braking technology, and particularly discloses a tension spring used in an automobile braking system, which comprises a tension spring, fixed columns arranged at the two ends of the tension spring, hooks arranged at the two ends of the tension spring and hung on the two fixed columns, the tension spring is installed in a brake drum, two brake shoes are further installed in the brake drum, mounting plates are connected to the brake shoes, connecting plates are arranged at the ends of the two mounting plates which are close to each other, rotating rings are rotatably installed on the connecting plates and sleeved on the spiral part of the tension spring. When the end of the tension spring is broken, the mounting plate can stretch the tension spring through the second telescopic rod, the connecting plate, the first pull ring, the second pull ring, the rotating seat, the prism and the rotating ring, the rotating ring is clamped on the tension spring in the reverse direction, the rotating ring is prevented from being separated from the tension spring, the driver can continue to brake, the driver can continue to brake after the end of the tension spring is broken, the driver can continue to drive to a repair shop for repair, and the situation that the automobile cannot be driven after the tension spring is broken is avoided.

Description

Technical Field

[0001] This invention relates to the field of automotive braking technology, and more particularly to a tension spring for use in automotive braking systems. Background Technology

[0002] Automotive braking is a braking technology used to slow down or stop a car during driving. Common brakes include disc brakes and drum brakes. The rotating element in the friction pair of a drum brake is the brake drum, and its working surface is a cylindrical surface. After braking, a drum brake needs to use a tension spring to drive the brake shoes to return to their original position.

[0003] Once the ends of the tension spring are fixed during installation, they generally cannot be adjusted. In order to maintain a high tension after braking, the tension spring is kept in a stretched state. After prolonged use, the spring's rebound force will decrease. Furthermore, the tension spring is under greater stress at its ends due to being in a stretched state for a long time, which may lead to breakage. Once the tension spring breaks, it is difficult for the brake shoes to reset, the car cannot continue to move, and it is extremely dangerous for the driver. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a tension spring for use in automotive braking systems.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A tension spring for an automotive braking system includes a tension spring with fixed posts at both ends. Hooks at both ends of the tension spring are respectively hung on the two fixed posts. The tension spring is installed inside a brake drum. Two brake shoes are also installed inside the brake drum. Mounting plates are connected to the brake shoes. Connecting plates are provided at the ends of the two mounting plates that are close to each other. The fixed posts are slidably connected to the mounting plates. A rotating ring is rotatably mounted on the connecting plate. The rotating ring is sleeved on the helical part of the tension spring. A reinforcing block is welded at the connection between the helical part of the tension spring and the hook.

[0007] Preferably, an L-shaped plate is slidably connected to the top of the mounting plate, the bottom of the horizontal end of the L-shaped plate is connected to the mounting plate, the bottom of the fixing column is fixedly connected to the top of the horizontal end of the L-shaped plate, a rubber plate is fixedly connected to the side of the vertical end of the L-shaped plate near the fixing column, a vertical groove is vertically opened on the side of the fixing column near the rubber plate, a vertical rod is provided in the vertical groove, a pull rod is fixedly connected to the bottom of the vertical rod, the end of the pull rod away from the vertical rod passes through the vertical end of the L-shaped plate, and the vertical end of the L-shaped plate is slidably connected.

[0008] Preferably, a first telescopic rod is fixedly connected to the side of the L-shaped plate away from the fixed column on the vertical end. A pull plate is fixedly connected to the end of the first telescopic rod away from the fixed column. The bottom of the pull plate is fixedly connected to the pull rod. A baffle is provided on the side of the pull plate away from the first telescopic rod. The bottom of the baffle is fixedly connected to the top of the mounting plate. A contact switch is fixedly installed on the side of the pull plate near the baffle. The contact switch can abut against the baffle.

[0009] Preferably, two limiting grooves are provided on the horizontal end of the L-shaped plate, and the two limiting grooves are located on both sides of the fixing column. Two threaded grooves are provided on the top of the mounting plate, and a second bolt is installed in the threaded groove, which passes through the limiting groove.

[0010] Preferably, the connecting plate has a circular groove, and a rotating seat is provided in the circular groove. The bottom of the rotating seat is rotatably connected to the bottom of the circular groove. A first pull ring is fixedly connected to one side of the rotating seat. A horizontal groove is provided on one side of the circular groove, and a second telescopic rod is provided in the horizontal groove. A second pull ring is fixedly connected to one end of the second telescopic rod, and the second pull ring is interlocked with the first pull ring. The other end of the second telescopic rod is fixedly connected to the mounting plate.

[0011] Preferably, the top of the rotating seat has a column groove, and a prism is slidably connected in the column groove along the vertical direction. A sliding groove is opened at the bottom of the prism along the horizontal direction, and a slider is slidably installed in the sliding groove. A third telescopic rod is fixedly connected to one end of the slider near the center of the prism, and the other end of the third telescopic rod away from the slider is fixedly connected to the inner wall of the sliding groove. A slot is opened on the bottom side wall of the column groove, and the slider can be locked in the slot. The top of the slider has an inclined surface.

[0012] Preferably, a brake cylinder is fixedly connected inside the brake drum, and the two ends of the brake cylinder abut against two brake shoes respectively. Two friction pads are provided inside the brake drum, and a mounting block is fixedly connected to the inner annular surface of the friction pads. The mounting block is connected to the brake shoes.

[0013] Preferably, the brake shoe has multiple mounting grooves on one side, and threaded holes are provided in the mounting grooves. The mounting block also has threaded holes of the same size. The mounting block is connected to the mounting groove by the first bolt. The mounting groove is located between the middle of the brake shoe and the end that abuts against the brake cylinder.

[0014] Preferably, when the mounting block is installed in a mounting groove far from the brake cylinder, the friction pads are closer to the inner ring surface of the brake drum.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. When the end of the tension spring breaks, the hook of the tension spring disengages from the helical part, the connecting plate disengages from the mounting plate and stretches the second telescopic rod. The first and second pull rings prevent the rotating ring from rotating, thus preventing the helical part of the tension spring from slipping out of the rotating ring. The end of the second telescopic rod pulls the first and second pull rings, and the rotating seat and rotating ring prevent the tension spring from continuing to contract. When braking, the mounting plate can stretch the tension spring through the second telescopic rod, connecting plate, first pull ring, second pull ring, rotating seat, prism and rotating ring. The rotating ring rotates in the opposite direction and locks the tension spring, preventing the rotating ring from disengaging from the tension spring. The driver can continue to brake, and can continue to drive to a relatively safe area or repair shop for repair after the end of the tension spring breaks, avoiding the situation where the car cannot be driven immediately after the tension spring breaks.

[0017] 2. When the tension spring breaks, the mounting plate pulls the connecting plate through the second telescopic rod. The second telescopic rod can reduce the tension on the tension spring and reduce the possibility of the helical part of the tension spring separating from the swivel. The reinforcing block on the tension spring jams the swivel after the tension spring breaks, further reducing the possibility of the helical part of the tension spring separating from the swivel.

[0018] 3. When adjusting the position of the mounting block, the mounting plate and connecting plate move with it. Adjusting the position of the mounting block away from the brake cylinder can increase the distance between the two mounting blocks, thereby increasing the distance between the two fixing posts and increasing the tension of the tension spring. After prolonged use, the tension spring may experience a decrease in rebound force. Adjusting the mounting block can simultaneously adjust the tension of the tension spring to ensure braking performance and increase the rebound efficiency of the tension spring.

[0019] 4. During braking, the brake cylinder pushes the two brake shoes to both sides. The brake shoes drive the mounting block and friction pads to move. The friction pads first contact the inside of the brake drum. After the friction pads wear to a certain extent, the first bolt can be unscrewed, and the mounting block can be installed in the mounting groove away from the brake cylinder. This reduces the gap between the friction pads and the brake drum. The distance between the friction pads and the brake drum remains constant, thus keeping the brake stroke of the brake cylinder constant. This prevents the brake performance from being affected by the wear of the friction pads, thereby increasing safety performance. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the tension spring shown in this invention;

[0021] Figure 2 As shown in this invention Figure 1 Enlarged schematic diagram of part A;

[0022] Figure 3 As shown in this invention Figure 1 Enlarged schematic diagram of part B;

[0023] Figure 4This is a schematic diagram showing the installation position of the tension spring according to the present invention;

[0024] Figure 5 This is a schematic diagram showing the installation position of the mounting block according to the present invention;

[0025] Figure 6 This is a schematic diagram of the structure of the fixed column shown in this invention;

[0026] Figure 7 This is a schematic diagram of the structure of the connecting plate shown in this invention;

[0027] Figure 8 This is a cross-sectional view of the connecting plate shown in this invention;

[0028] Figure 9 This is a cross-sectional view of the rotating seat shown in this invention.

[0029] In the diagram: 1. Tension spring; 2. Reinforcing block; 3. Rotary ring; 4. Fixed column; 5. Brake drum; 6. Brake shoe; 7. Mounting groove; 8. Mounting block; 9. First bolt; 10. Friction plate; 11. Mounting plate; 12. Connecting plate; 13. L-shaped plate; 14. Second bolt; 15. Limiting groove; 16. Rubber plate; 17. Pull rod; 18. Pull plate; 19. First telescopic rod; 20. Contact switch; 21. Baffle; 22. Brake cylinder; 23. Rotating seat; 24. Prism; 25. Horizontal groove; 26. Second telescopic rod; 27. First pull ring; 28. Second pull ring; 29. ​​Slider; 30. Third telescopic rod; 31. Vertical rod. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] Reference Figure 1-9A tension spring for an automotive braking system includes a tension spring 1, with fixed posts 4 at both ends of the tension spring 1. Hooks at both ends of the tension spring 1 are respectively hung on the two fixed posts 4. The tension spring 1 is installed inside a brake drum 5. Two brake shoes 6 are also installed inside the brake drum 5. Mounting plates 11 are connected to the brake shoes 6. Connecting plates 12 are provided at the ends of the two mounting plates 11 that are close to each other. The fixed posts 4 are slidably connected to the mounting plates 11. A rotating ring 3 is rotatably installed on the connecting plate 12. The rotating ring 3 is sleeved on the helical part of the tension spring 1. A reinforcing block 2 is welded at the connection between the helical part of the tension spring 1 and the hook. When prolonged use causes the end of the tension spring 1 to break, the hook of the tension spring 1 disengages from the helical part. When the tension spring 1 contracts, it pulls the rotating ring 3. The first pull ring 27 and the second pull ring 28 prevent the rotating ring 3 from rotating, thus preventing the helical part of the tension spring 1 from slipping out of the rotating ring 3. The end of the second telescopic rod 26 pulls the first pull ring 27 and the second pull ring 28. Through the rotating seat 23 and the rotating ring 3, the tension spring 1 can be prevented from continuing to contract. When braking, the mounting plate 11 can stretch the tension spring 1 through the second telescopic rod 26, the connecting plate 12, the first pull ring 27, the second pull ring 28, the rotating seat 23, the prism 24 and the rotating ring 3. The rotating ring 3 rotates in the opposite direction and locks the tension spring 1, preventing the rotating ring 3 from losing contact with the tension spring 1. The driver can continue to brake, ensuring that braking can continue even after the end of the tension spring 1 breaks. The driver can continue to drive to a relatively safe area or repair shop for repair, avoiding the situation where the car cannot be driven immediately after the tension spring 1 breaks.

[0032] As a technical optimization of the present invention, an L-shaped plate 13 is slidably connected to the top of the mounting plate 11. The bottom of the horizontal end of the L-shaped plate 13 is connected to the mounting plate 11. The bottom of the fixing post 4 is fixedly connected to the top of the horizontal end of the L-shaped plate. A rubber plate 16 is fixedly connected to the side of the vertical end of the L-shaped plate 13 near the fixing post 4. A vertical groove is vertically opened on the side of the fixing post 4 near the rubber plate 16. A vertical rod 31 is provided in the groove. A pull rod 17 is fixedly connected to the bottom of the vertical rod 31. The end of the pull rod 17 away from the vertical rod 31 passes through the vertical end of the L-shaped plate 13, and the vertical end of the L-shaped plate 13 is slidably connected. When the tension spring 1 breaks, the first telescopic rod 19 resets and pushes the pull plate 18 away from the fixing post 4. The pull plate 18 drives the pull rod 17 and the vertical rod 31 to move. The vertical rod 31 is provided with a rubber sheet to increase friction. The vertical rod 31 and the pull plate 18 will clamp the hook of the tension spring 1 to prevent the hook of the tension spring 1 from falling out of the brake drum 5, affecting the brake and causing danger.

[0033] As a technical optimization of the present invention, a first telescopic rod 19 is fixedly connected to the side of the L-shaped plate 13 away from the fixed post 4. A pull plate 18 is fixedly connected to the end of the first telescopic rod 19 away from the fixed post 4. The bottom of the pull plate 18 is fixedly connected to the pull rod 17. A baffle 21 is provided on the side of the pull plate 18 away from the first telescopic rod 19. The bottom of the baffle 21 is fixedly connected to the top of the mounting plate 11. A contact switch 20 is fixedly installed on the side of the pull plate 18 near the baffle 21. The contact switch 20 can abut against the baffle 21. When the first telescopic rod 19 pushes the pull plate 18 to move, the baffle 21 is made of rubber. The baffle 21 will squeeze the contact switch 20 without hindering the movement of the pull plate 18. An alarm is connected to the contact switch 20 to promptly remind the driver that the tension spring 1 inside the brake drum 5 has broken, allowing the driver to have it repaired in time.

[0034] As a technical optimization of the present invention, two limiting grooves 15 are formed on the horizontal end of the L-shaped plate 13, and the two limiting grooves 15 are respectively located on both sides of the fixing post 4. Two threaded grooves are formed on the top of the mounting plate 11, and a second bolt 14 is installed in the threaded groove, which passes through the limiting groove 15. When the distance between the two fixing posts 4 needs to be finely adjusted, the position of the L-shaped plate 13 can be adjusted by the limiting grooves 15 and the second bolts 14, thereby increasing the range of adjustment for the distance between the two fixing posts 4.

[0035] As a technical optimization of the present invention, a circular groove is provided on the connecting plate 12, and a rotating seat 23 is provided in the circular groove. The bottom of the rotating seat 23 is rotatably connected to the bottom of the circular groove. A first pull ring 27 is fixedly connected to one side of the rotating seat 23. A horizontal groove 25 is provided on one side of the circular groove, and a second telescopic rod 26 is provided in the horizontal groove 25. A second pull ring 28 is fixedly connected to one end of the second telescopic rod 26, and the second pull ring 28 is engaged with the first pull ring 27. The other end of the second telescopic rod 26 is fixedly connected to the mounting plate 11. The first pull ring 27 and the second pull ring 28 prevent the rotating ring 3 from rotating, thus preventing the spiral part of the tension spring 1 from slipping out of the rotating ring 3. Furthermore, the end of the second telescopic rod 26 pulls the first pull ring 27 and the second pull ring 28, and the rotating seat 23 and the rotating ring 3 can lock the tension spring 1, further preventing the rotating ring 3 and the tension spring 1 from slipping out.

[0036] As a technical optimization of the present invention, the top of the rotating seat 23 is provided with a column groove, and a prism 24 is slidably connected in the vertical direction within the column groove. A sliding groove is provided at the bottom of the prism 24 in the horizontal direction, and a slider 29 is slidably installed within the sliding groove. A third telescopic rod 30 is fixedly connected to one end of the slider 29 near the center of the prism 24, and the other end of the third telescopic rod 30 away from the slider 29 is fixedly connected to the inner wall of the sliding groove. A retaining groove is provided on the bottom side wall of the column groove, allowing the slider 29 to be engaged in the retaining groove. The top of the slider 29 is provided with an inclined surface. The prism 24 on the rotating ring 3 is inserted into the top of the rotating seat 23, causing the slider 29 to be engaged in the retaining groove, which prevents the prism 24 from disengaging from the column groove when the tension spring 1 pulls the prism 24.

[0037] As a technical optimization of the present invention, a brake cylinder 22 is fixedly connected inside the brake drum 5. The two ends of the brake cylinder 22 abut against two brake shoes 6 respectively. Two friction pads 10 are provided inside the brake drum 5. A mounting block 8 is fixedly connected to the inner circumference of each friction pad 10, and the mounting block 8 is connected to the brake shoes 6. The friction pads 10 initially contact the inner side of the brake drum 5. After the friction pads 10 have worn to a certain extent, the mounting block 8 can be installed in a mounting groove 7 away from the brake cylinder 22, thereby reducing the gap between the friction pads 10 and the brake drum 5. Maintaining a constant distance between the friction pads 10 and the brake drum 5 ensures that the braking stroke of the brake cylinder 22 remains constant, preventing wear of the friction pads 10 from affecting braking performance and increasing safety.

[0038] As a technical optimization of the present invention, a plurality of mounting grooves 7 are provided on one side of the brake shoe 6, and threaded holes are provided in the mounting grooves 7. The mounting block 8 is also provided with threaded holes of the same size. The mounting block 8 is connected to the mounting groove 7 by the first bolt 9. The mounting groove 7 is located between the middle of the brake shoe 6 and the end that abuts against the brake cylinder 22. As a technical optimization of the present invention, when the mounting block 8 is installed in the mounting groove 7 away from the brake cylinder 22, the friction plate 10 is closer to the inner ring surface of the brake drum 5. When adjusting the position of mounting block 8, mounting plate 11 and connecting plate 12 move with it. Adjusting the position of mounting block 8 away from brake cylinder 22 can increase the distance between the two mounting blocks 8, thereby increasing the distance between the two fixing posts 4 and increasing the tension of spring 1. After prolonged use, spring 1 may experience a decrease in rebound force. Adjusting mounting block 8 can simultaneously adjust the tension of spring 1, ensuring braking performance and increasing the rebound efficiency of spring 1. The two brake shoes 6 of the leading and trailing shoe brake may have different wear levels. When the two friction pads 10 have different wear levels, the position of one of the mounting blocks 8 can be adjusted, allowing for individual adjustment based on the actual wear condition.

[0039] When using this invention, firstly, install the mounting block 8 into the mounting groove 7 near the brake cylinder 22, tighten the first bolt 9, push the pull plate 18 so that the vertical rod 31 is located in the vertical groove, then hang the hook of the tension spring 1 on the two fixed columns 4 respectively, and then insert the prism 24 on the rotating ring 3 into the top of the rotating seat 23 so that the slider 29 is locked in the slot to prevent the prism 24 from disengaging from the column slot when the tension spring 1 pulls the prism 24.

[0040] When prolonged use causes the end of the tension spring 1 to break, the hook of the tension spring 1 disengages from the helical part. At this time, the fixing post 4 can no longer keep the tension spring 1 stretched. When the tension spring 1 contracts, it pulls the rotating ring 3. The rotating ring 3 pulls the prism 24, the rotating seat 23, and the connecting plate 12. The connecting plate 12 disengages from the mounting plate 11 and stretches the second telescopic rod 26. The first pull ring 27 and the second pull ring 28 prevent the rotating ring 3 from rotating, thus preventing the helical part of the tension spring 1 from slipping out of the rotating ring 3. At the same time, the end of the second telescopic rod 26 pulls the first pull ring 27 and the second pull ring 28, which, through the rotating seat 23 and The rotating ring 3 can prevent the tension spring 1 from continuing to contract. When braking, the mounting plate 11 can stretch the tension spring 1 through the second telescopic rod 26, the connecting plate 12, the first pull ring 27, the second pull ring 28, the rotating seat 23, the prism 24 and the rotating ring 3. The rotating ring 3 will lock the tension spring 1 when it rotates in the opposite direction, preventing the rotating ring 3 from losing contact with the tension spring 1. The driver can continue to brake, so that the driver can continue to brake even after the end of the tension spring 1 breaks. The driver can continue to drive to a relatively safe area or repair shop for repair, avoiding the situation where the car cannot be driven immediately after the tension spring 1 breaks.

[0041] When the tension spring 1 breaks, the mounting plate 11 pulls the connecting plate 12 through the second telescopic rod 26. The second telescopic rod 26 can reduce the tension on the tension spring 1 and reduce the possibility of the helical part of the tension spring 1 separating from the rotating ring 3. The reinforcing block 2 on the tension spring 1 jams the rotating ring 3 after the tension spring 1 breaks, further reducing the possibility of the helical part of the tension spring 1 separating from the rotating ring 3.

[0042] The first pull ring 27 and the second pull ring 28 allow the rotating seat 23 to rotate at a certain angle in its natural state. When the tension spring 1 is in normal tension and contraction, the rotating ring 3 can rotate, thus preventing the rotating ring 3 from affecting the tension and contraction of the tension spring 1 in its normal state.

[0043] When the tension spring 1 breaks, the first telescopic rod 19 resets and pushes the pull plate 18 away from the fixed column 4. The pull plate 18 drives the pull rod 17 and the vertical rod 31 to move. The vertical rod 31 is provided with a rubber sheet to increase friction. The vertical rod 31 and the pull plate 18 will clamp the hook of the tension spring 1 to prevent the hook of the tension spring 1 from falling out of the brake drum 5, affecting the brake and causing danger.

[0044] The pull plate 18 is equipped with a magnetic block. When the tension spring 1 breaks, it works with the rubber plate 16 and the vertical rod 31 to fix the hook of the broken tension spring 1, further preventing the hook of the tension spring 1 from falling off. When the first telescopic rod 19 pushes the pull plate 18 to move, the baffle 21 is made of rubber. The baffle 21 will squeeze the contact switch 20 without obstructing the movement of the pull plate 18. The contact switch 20 is connected to an alarm, which can promptly remind the driver that the tension spring 1 in the brake drum 5 has broken, allowing the driver to have it repaired in time.

[0045] When braking, the brake cylinder 22 pushes the two brake shoes 6 to both sides. The brake shoes 6 drive the mounting block 8 and the friction pad 10 to move. The friction pad 10 first contacts the inner side of the brake drum 5. After the friction pad 10 is worn to a certain extent, the first bolt 9 can be unscrewed, and the mounting block 8 can be installed in the mounting groove 7 away from the brake cylinder 22, thereby reducing the gap between the friction pad 10 and the brake drum 5. The distance between the friction pad 10 and the brake drum 5 is kept constant, so that the braking stroke of the brake cylinder 22 is kept constant, avoiding the impact of friction pad 10 wear on braking performance and increasing safety performance.

[0046] After the friction pad 10 is completely worn, the brake pads on the brake shoe 6 can continue to be used, which increases the service life of the brake. After the friction pad 10 is worn, the friction pad 10 and the mounting block 8 can be replaced directly without replacing the brake shoe 6 and the brake pads on the brake shoe 6, making replacement simpler and reducing costs.

[0047] When adjusting the position of the mounting block 8, the mounting plate 11 and the connecting plate 12 move with it. Adjusting the position of the mounting block 8 away from the brake cylinder 22 can increase the distance between the two mounting blocks 8, thereby increasing the distance between the two fixing posts 4 and increasing the tension of the tension spring 1. After prolonged use, the tension spring 1 may experience a decrease in rebound force. Adjusting the mounting block 8 can simultaneously adjust the tension of the tension spring 1, ensuring braking performance and increasing the rebound efficiency of the tension spring 1.

[0048] The two brake shoes 6 of the leading-follower shoe brake may have different degrees of wear. When the two friction pads 10 have different degrees of wear, the position of one of the mounting blocks 8 can be adjusted to make individual adjustments according to the actual wear condition.

[0049] L-shaped plate 13 is connected to mounting plate 11 by second bolt 14. When the distance between the two fixed posts 4 needs to be finely adjusted, the position of L-shaped plate 13 can be adjusted by limiting groove 15 and second bolt 14 to increase the range of adjustment of the distance between the two fixed posts 4.

[0050] The above description is only 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. A tension spring for use in an automotive braking system, comprising a tension spring (1), characterized in that, The tension spring (1) has fixed posts (4) at both ends. The hooks at both ends of the tension spring (1) are respectively hung on the two fixed posts (4). The tension spring (1) is installed inside the brake drum (5). Two brake shoes (6) are also installed inside the brake drum (5). A mounting plate (11) is connected to the brake shoes (6). A connecting plate (12) is provided at the end of the two mounting plates (11) that are close to each other. The fixed posts (4) are slidably connected to the mounting plates (11). A rotating ring (3) is rotatably installed on the connecting plate (12). The rotating ring (3) is sleeved on the helical part of the tension spring (1). A reinforcing block (2) is welded at the connection between the helical part of the tension spring (1) and the hook. The mounting plate (11) is slidably connected to the top of an L-shaped plate (13). The bottom of the horizontal end of the L-shaped plate (13) is connected to the mounting plate (11). The bottom of the fixing column (4) is fixedly connected to the top of the horizontal end of the L-shaped plate. A rubber plate (16) is fixedly connected to the side of the vertical end of the L-shaped plate (13) near the fixing column (4). A vertical groove is vertically opened on the side of the fixing column (4) near the rubber plate (16). A vertical rod (31) is provided in the vertical groove. A pull rod (17) is fixedly connected to the bottom of the vertical rod (31). The end of the pull rod (17) away from the vertical rod (31) passes through the vertical end of the L-shaped plate (13), and the vertical end of the L-shaped plate (13) is slidably connected.

2. A tension spring for an automotive braking system according to claim 1, characterized in that, The vertical end of the L-shaped plate (13) away from the fixed column (4) is fixedly connected to a first telescopic rod (19). The end of the first telescopic rod (19) away from the fixed column (4) is fixedly connected to a pull plate (18). The bottom of the pull plate (18) is fixedly connected to the pull rod (17). A baffle (21) is provided on the side of the pull plate (18) away from the first telescopic rod (19). The bottom of the baffle (21) is fixedly connected to the top of the mounting plate (11). A contact switch (20) is fixedly installed on the side of the pull plate (18) near the baffle (21). The contact switch (20) can abut against the baffle (21).

3. A tension spring for an automotive braking system according to claim 2, characterized in that, The L-shaped plate (13) has two limiting grooves (15) on its horizontal end. The two limiting grooves (15) are located on both sides of the fixing column (4). The mounting plate (11) has two threaded grooves on its top. The second bolt (14) is installed in the threaded groove and passes through the limiting groove (15).

4. A tension spring for an automotive braking system according to claim 1, characterized in that, The connecting plate (12) has a circular groove, and a rotating seat (23) is provided in the circular groove. The bottom of the rotating seat (23) is rotatably connected to the bottom of the circular groove. A first pull ring (27) is fixedly connected to one side of the rotating seat (23). A horizontal groove (25) is horizontally provided on one side of the circular groove. A second telescopic rod (26) is provided in the horizontal groove (25). A second pull ring (28) is fixedly connected to one end of the second telescopic rod (26). The second pull ring (28) is interlocked with the first pull ring (27). The other end of the second telescopic rod (26) is fixedly connected to the mounting plate (11).

5. A tension spring for an automotive braking system according to claim 4, characterized in that, The rotating seat (23) has a column groove at the top, and a prism (24) is slidably connected in the vertical direction in the column groove. A sliding groove is opened at the bottom of the prism (24) in the horizontal direction. A slider (29) is slidably installed in the sliding groove. A third telescopic rod (30) is fixedly connected to one end of the slider (29) near the center of the prism (24). The end of the third telescopic rod (30) away from the slider (29) is fixedly connected to the inner wall of the sliding groove. A slot is opened on the bottom side wall of the column groove, and the slider (29) can be locked in the slot. The top of the slider (29) has an inclined surface.

6. A tension spring for an automotive braking system according to claim 1, characterized in that, A brake cylinder (22) is fixedly connected inside the brake drum (5). The two ends of the brake cylinder (22) abut against two brake shoes (6) respectively. Two friction plates (10) are provided inside the brake drum (5). An mounting block (8) is fixedly connected to the inner ring surface of the friction plate (10). The mounting block (8) is connected to the brake shoe (6).

7. A tension spring for an automotive braking system according to claim 6, characterized in that, The brake shoe (6) has multiple mounting grooves (7) on one side, and threaded holes are provided in the mounting grooves (7). The mounting block (8) also has threaded holes of the same size. The mounting block (8) is connected to the mounting groove (7) by the first bolt (9). The mounting groove (7) is located between the middle of the brake shoe (6) and the end that abuts against the brake cylinder (22).

8. A tension spring for an automotive braking system according to claim 7, characterized in that, When the mounting block (8) is installed in the mounting groove (7) away from the brake cylinder (22), the friction pad (10) is closer to the inner ring surface of the brake drum (5).

Images