Dual cylinder control system and tracked vehicle braking device

Abstract

The utility model relates to a kind of double-oil-cylinder control system and tracked vehicle brake device, involve hydraulic steering brake actuator field, the utility model to solve the existing tracked loader adopts steering pull rod by connecting rod to make clutch separate, simultaneously drive brake pad braking, make driving wheel deceleration or stop, different from the operation mode of transmission vehicle, lead to user operation inconvenience, and cannot realize the problem of sliding to, including left telescopic cylinder, right telescopic cylinder and energy accumulator I, the oil return of left telescopic cylinder and right telescopic cylinder is all communicated with energy accumulator I;It also includes oil supply system, full hydraulic steering gear I, full hydraulic steering gear II, check valve I, check valve II, check valve III, check valve IV and delay closing device, the utility model is used for tracked vehicle brake steering control.

Description

Technical Field

[0001] This invention relates to the field of hydraulic steering and braking actuators, and particularly to a dual-cylinder control system and a braking device for tracked vehicles. Background Technology

[0002] Tracked vehicles are vehicles that use a tracked running system instead of a wheeled running system. Tracked vehicles have strong traversal capabilities on unpaved roads, and special tracked vehicles have long tracks, strong climbing ability, and strong adaptability to complex terrain in forest areas. Existing tracked loader transmission systems often use hydrostatic drive devices or driveshafts combined with mechanical gearboxes. Among them, the driveshaft combined with a mechanical gearbox transmission has advantages such as high transmission efficiency and large transmission torque. Its widespread use in forest fire-fighting tracked loaders has given tracked loaders advantages such as high torque, strong passability, and the ability to climb slopes. When turning, existing driveshaft-type tracked loaders cut off power to the rear axle drive wheels by pulling a single-sided steering lever in the cab, simultaneously pressing the brake friction pads to brake one side of the vehicle, thus creating a speed difference between the two tracks and completing the turning operation. When braking, tracked loaders need to pull both left and right steering levers simultaneously, and the brake friction pads brake both drive wheels of the vehicle simultaneously, thus achieving the effect of service braking.

[0003] However, existing tracked loaders use a steering tie rod to disengage the clutch via a connecting rod, which simultaneously engages the brake friction pads to slow or stop the drive wheels. This differs from the operation of traditional transmission vehicles, making it inconvenient for users. Furthermore, the steering tie rod has a relatively large pulling torque, typically between 200N and 500N, making it difficult to precisely control the braking intensity during steering and thus hindering accurate slip steering. Summary of the Invention

[0004] This invention addresses the problems of existing tracked loaders that use a steering tie rod to disengage the clutch via a connecting rod, simultaneously engaging the brake friction pads to decelerate or stop the drive wheels. This differs from the operation of conventional vehicles with transmission systems, leading to inconvenience for users. Furthermore, the steering tie rod has a relatively large pulling torque, typically between 200N and 500N, making it difficult to precisely control braking intensity during steering and achieving accurate slip steering. Therefore, this invention provides a dual-cylinder control system and a tracked vehicle braking device to solve the problems mentioned in the background art.

[0005] The technical solution of this invention is:

[0006] A dual-cylinder control system includes a left telescopic cylinder, a right telescopic cylinder, and an accumulator I, wherein the oil return ports of both the left and right telescopic cylinders are connected to the accumulator I.

[0007] It also includes an oil supply system, a fully hydraulic steering gear I, a fully hydraulic steering gear II, a check valve I, a check valve II, a check valve III, a check valve IV, and a time-delayed shut-off device;

[0008] Port B of the fully hydraulic steering gear I is connected to the inlet ports of check valve I and check valve II. The outlet port of check valve I is connected to the inlet port of the right telescopic cylinder and the inlet port of check valve III. The outlet port of check valve II is connected to the inlet port of the left telescopic cylinder and the inlet port of check valve IV. The outlet ports of check valve III and check valve IV are connected to port B of the fully hydraulic steering gear I through the actuator of the time-delay closing device. The control terminal of the time-delay closing device is connected to port A of the fully hydraulic steering gear I. The T port of the fully hydraulic steering gear I is connected to the oil tank return pipe, and the P port of the fully hydraulic steering gear I is connected to the A port of the oil supply system; the A port of the fully hydraulic steering gear II is connected to the oil outlet of the one-way valve II and the oil inlet of the left telescopic cylinder, the B port of the fully hydraulic steering gear II is connected to the oil outlet of the one-way valve I and the oil inlet of the right telescopic cylinder, the T port of the fully hydraulic steering gear II is connected to the oil tank return pipe, and the P port of the fully hydraulic steering gear II is connected to the B port of the oil supply system.

[0009] Furthermore, it also includes a normally open hydraulic control valve, the oil inlet of which is connected to the T port of the fully hydraulic steering gear II, the oil outlet of which is connected to the oil return pipe of the oil tank, and the control end of which is connected to the B port of the fully hydraulic steering gear I.

[0010] Furthermore, the delayed shutdown device includes an accumulator II and a normally closed hydraulic control valve. The actuating end of the delayed shutdown device is the oil inlet and outlet of the normally closed hydraulic control valve. The oil outlets of check valves III and IV are connected to the oil inlet of the normally closed hydraulic control valve. The oil outlet of the normally closed hydraulic control valve is connected to port B of the fully hydraulic steering gear I. The control end of the normally closed hydraulic control valve and the oil inlet of accumulator II are connected to port A of the fully hydraulic steering gear I.

[0011] Furthermore, the oil supply system includes a gear pump and a single-path stabilizing flow divider valve. The inlet of the gear pump is connected to the oil tank, and the outlet of the gear pump is connected to the inlet of the single-path stabilizing flow divider valve. Port A of the single-path stabilizing flow divider valve is the A port of the oil supply system, and port B of the single-path stabilizing flow divider valve is the B port of the oil supply system.

[0012] Furthermore, the output flow rate at port B of the single-channel stable diverter valve is 15 L / min.

[0013] Furthermore, a relief valve I is connected to port B of the single-path stable flow divider valve, and the overflow port of relief valve I is connected to the oil return pipe of the oil tank.

[0014] Furthermore, the output port of the gear pump is connected to an overflow valve II, and the overflow port of the overflow valve II is connected to the oil return pipe of the oil tank.

[0015] Furthermore, the control end of the fully hydraulic steering gear I is connected to the brake pedal, and the control end of the fully hydraulic steering gear II is connected to the steering wheel shaft.

[0016] A tracked vehicle braking device includes a frame, a rear axle box, a brake shaft, a steering arm, a left telescopic cylinder, a right telescopic cylinder, and a handbrake push rod;

[0017] The rear axle housing is fixed to the frame. Steering arms are fixedly connected to the brake axles on both sides of the rear axle housing. Sliding protrusions are provided on both the upper and lower sides of the steering arms. The fixed ends of the left and right telescopic cylinders are hinged to the frame. The movable ends of the left and right telescopic cylinders are fixed with a lower elongated hole connector. The two lower elongated hole connectors are slidably connected to the elongated holes in the sliding protrusions at the lower end of the corresponding steering arms. The two handbrake push rods are fixed with upper elongated hole connectors. The two upper elongated hole connectors are slidably connected to the elongated holes in the sliding protrusions at the upper end of the steering arms.

[0018] Furthermore, the sliding protrusion at the upper end of the steering arm abuts against the left end of the long hole in the upper long hole connector, and the sliding protrusion at the lower end of the steering arm abuts against the right end of the long hole in the lower long hole connector.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. The dual-cylinder control system of this invention controls the extension of either the left or right telescopic cylinder via a fully hydraulic steering gear II to steer the tracked loader, and controls the extension of both the left and right telescopic cylinders via a fully hydraulic steering gear I to brake the tracked loader. The fully hydraulic steering gear provides power assist, resulting in a steering wheel torque of 20 N·m. Therefore, compared to the traditional braking method where the brake pedal drives the brake friction pads via a linkage, the operation is more effortless.

[0021] 2. The tracked loader uses a steering wheel and brake pedal to control steering and braking, making its operation similar to that of conventional vehicles, thus facilitating driver control. Furthermore, the steering wheel drives the fully hydraulic steering system to supply oil to the brake cylinders, allowing for slight braking on one side with a short stroke of the brake cylinders, enabling slip steering and more precise steering.

[0022] 3. Equipped with a normally open hydraulic control valve, when the brake pedal is pressed, hydraulic oil flows into the control end of the normally open hydraulic control valve, the normally open hydraulic control valve closes, cutting off the return oil circuit of the fully hydraulic steering gear II, so that the control function of the fully hydraulic steering gear II is disabled, so that even if the steering wheel is turned after the brake pedal is pressed, the braking system is still in the braking state, ensuring the stability of the braking action.

[0023] 4. A delayed-closing device is installed, comprising an accumulator II and a normally closed hydraulic control valve. During the brake reset action, when the output oil pressure at port IA of the fully hydraulic steering gear decreases, the hydraulic oil stored in accumulator II is released. Accumulator II continues to supply oil to the control end of the normally closed hydraulic control valve, causing the normally closed hydraulic control valve to close with a 0.5s delay, thus achieving the delay effect and allowing the left and right telescopic cylinders to fully reset until the braking effect disappears. This prevents the brakes from remaining in a braking state due to incomplete reset of the left and right telescopic cylinders.

[0024] 5. In the tracked vehicle braking device of the present invention, the handbrake push rod, left telescopic cylinder, and right telescopic cylinder on the rear axle box respectively drive the steering arm to rotate through the upper and lower elongated hole connectors to complete handbrake braking or hydraulic braking. When the left and right telescopic cylinders drive the steering arm to rotate clockwise through the lower elongated hole connector, bilateral braking of the drive wheels is completed in the moving state, and the upper end of the steering arm slides in the upper elongated hole connector; when the handbrake push rod drives the steering arm to rotate clockwise through the upper elongated hole connector, handbrake braking is completed in the stopped state, and the lower end of the steering arm slides in the lower elongated hole connector. This achieves rear axle braking by both the handbrake push rod and the left and right telescopic cylinders, and the braking actions do not interfere with each other. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the hydraulic steering and braking system of the present invention;

[0026] Figure 2 This is a schematic diagram of the hydraulic steering and braking system of the present invention for left-turning.

[0027] Figure 3 This is a schematic diagram of the hydraulic steering and braking system of the present invention for right-turning.

[0028] Figure 4 This is a schematic diagram of the braking principle of the hydraulic steering braking system of the present invention;

[0029] Figure 5 This is a schematic diagram of the brake reset principle of the hydraulic steering brake system of the present invention;

[0030] Figure 6 This is a schematic diagram of the structure of a tracked loader;

[0031] Figure 7 This is a schematic diagram of the rear axle housing structure;

[0032] Figure 8 This is a side view of the rear axle housing;

[0033] Figure 9 This is a side view of the hydraulic braking device and the handbrake braking device;

[0034] Figure 10 This is a schematic diagram of the hydraulic braking device and the handbrake braking device.

[0035] In the diagram: 101, Left telescopic cylinder; 102, Right telescopic cylinder; 103, Accumulator I; 2, Oil supply system; 301, Fully hydraulic steering gear I; 302, Fully hydraulic steering gear II; 303, Check valve I; 304, Check valve II; 305, Check valve III; 306, Check valve IV; 4, Normally open hydraulic control valve; 5, Delayed closing device; 501, Accumulator II; 502, Normally closed hydraulic control valve; 201, Gear pump; 202, Single-path stabilizing diverter valve; 203, Relief valve I; 204, Relief valve II; 601, Rear axle housing; 602, Brake shaft; 603, Steering arm; 604, Handbrake push rod; 605, Upper elongated hole connector; 606, Lower elongated hole connector; 607, Sliding protrusion. Detailed Implementation

[0036] Specific implementation method one: See Figures 1-5 As shown, the dual-cylinder control system of this embodiment includes a left telescopic cylinder 101, a right telescopic cylinder 102 and an accumulator I 103. The oil return ports of the left telescopic cylinder 101 and the right telescopic cylinder 102 are both connected to the accumulator I 103.

[0037] It also includes an oil supply system 2, a fully hydraulic steering gear I 301, a fully hydraulic steering gear II 302, a check valve I 303, a check valve II 304, a check valve III 305, a check valve IV 306, and a delayed closing device 5; the B port of the fully hydraulic steering gear I 301 is connected to the oil inlet ports of check valve I 303 and check valve II 304, the oil outlet port of check valve I 303 is connected to the oil inlet port of the right telescopic cylinder 102 and the oil inlet port of check valve III 305, the oil outlet port of check valve II 304 is connected to the oil inlet port of the left telescopic cylinder 101 and the oil inlet port of check valve IV 306, and the oil outlet ports of check valve III 305 and check valve IV 306 are connected to the fully hydraulic steering gear I 301 through the actuator of the delayed closing device 5. The B port of hydraulic steering gear I 301 is connected; the control terminal of the delayed closing device 5 is connected to the A port of the full hydraulic steering gear I 301; the T port of the full hydraulic steering gear I 301 is connected to the oil tank return pipe; and the P port of the full hydraulic steering gear I 301 is connected to the A port of the oil supply system 2. The A port of the full hydraulic steering gear II 302 is connected to the oil outlet of the one-way valve II 304 and the oil inlet of the left telescopic cylinder 101; the B port of the full hydraulic steering gear II 302 is connected to the oil outlet of the one-way valve I 303 and the oil inlet of the right telescopic cylinder 102; the T port of the full hydraulic steering gear II 302 is connected to the oil tank return pipe; and the P port of the full hydraulic steering gear II 302 is connected to the B port of the oil supply system 2.

[0038] Furthermore, by using the steering wheel to drive the fully hydraulic steering gear II 302 to supply oil to the left telescopic cylinder 101 or the right telescopic cylinder 102, a short-stroke unilateral advance of the left or right telescopic cylinder 101 or 102 can be achieved. The short-stroke advance of the brake cylinder completes slight unilateral braking, allowing a small speed difference between the two forward wheels of the tracked vehicle, enabling the tracked loader to turn at a small angle and achieve more precise steering. Similarly, the brake pedal, controlled by the fully hydraulic steering gear I 301, allows the left and right telescopic cylinders 101 and 102 to advance synchronously with short strokes, achieving partial or slight braking. When used in tracked fire trucks operating at higher speeds in forest areas, this further enhances the precision of steering and braking.

[0039] Specific Implementation Method Two: See Figures 1-5 As shown, this embodiment also includes a normally open hydraulic control valve 4. The oil inlet of the normally open hydraulic control valve 4 is connected to the T port of the fully hydraulic steering gear II 302, the oil outlet of the normally open hydraulic control valve 4 is connected to the oil return pipe of the oil tank, and the control end of the normally open hydraulic control valve 4 is connected to the B port of the fully hydraulic steering gear I 301.

[0040] Furthermore, the normally open hydraulic control valve 4 is used to disconnect the return oil circuit between the T port of the fully hydraulic steering gear II 302 and the oil tank after the brake pedal is depressed. When the brake pedal is depressed, hydraulic oil flows into the control terminal of the normally open hydraulic control valve 4, which closes, cutting off the return oil circuit of the fully hydraulic steering gear II 302. This prevents the oil in the rodless chambers of the left telescopic cylinder 101 and the right telescopic cylinder 102 from flowing back into the fully hydraulic steering gear II 302, thus disabling the control function of the fully hydraulic steering gear II 302. This ensures that even when the steering wheel is turned after the brake pedal is depressed, the braking state remains, ensuring the stability and priority of the braking action. The trigger pressure of the control terminal of the normally open hydraulic control valve 4 is 1 MPa.

[0041] Specific implementation method three: See Figures 1-5 As shown, the delayed shutdown device 5 of this embodiment includes an accumulator II 501 and a normally closed hydraulic control valve 502. The actuating end of the delayed shutdown device 5 is the oil inlet and oil outlet of the normally closed hydraulic control valve 502. The oil outlets of check valve III 305 and check valve IV 306 are connected to the oil inlet of the normally closed hydraulic control valve 502. The oil outlet of the normally closed hydraulic control valve 502 is connected to port B of the fully hydraulic steering gear I 301. The control end of the normally closed hydraulic control valve 502 and the oil inlet of the accumulator II 501 are connected to port A of the fully hydraulic steering gear I 301.

[0042] Furthermore, the normally closed hydraulic control valve 502 is used to close the common return oil circuit of the left telescopic cylinder 101 and the right telescopic cylinder 102, so that the common return oil circuit of the left telescopic cylinder 101 and the right telescopic cylinder 102 is only opened during brake reset. An accumulator II 501 is provided to store the oil output from port A of the fully hydraulic steering gear I 301 during the brake pedal release process, and to stabilize the trigger hydraulic pressure at the control end of the normally closed hydraulic control valve 502 during the brake pedal release process. A torsion spring is provided at the brake pedal hinge for reset release. During the brake pedal release process, the valve core of the fully hydraulic steering gear I 301 first moves from the right position to the center position, supplying oil to port A and returning oil to port B of the fully hydraulic steering gear I 301. Simultaneously, the normally closed hydraulic control valve 502 opens, the left telescopic cylinder 101 and the right telescopic cylinder 102 retract, and the braking effect disappears. Then the valve core of the fully hydraulic steering gear I301 reaches the neutral position, and finally the valve core crosses the neutral position to reach the left position, and connects port A and port T to the oil return position. At this time, the oil stored in accumulator II501 flows back to the oil tank through port A.

[0043] Furthermore, when the output oil pressure at port A of the fully hydraulic steering gear I 301 decreases, the accumulator II 501 releases pressure into the control terminal of the normally closed hydraulic control valve 502, extending the opening time of the normally closed hydraulic control valve 502 by 0.5 seconds. This ensures the smooth flow of the return oil circuit, allowing the left telescopic cylinder 101 and the right telescopic cylinder 102 to fully reset and retract until the braking effect disappears. This prevents the left telescopic cylinder 101 and the right telescopic cylinder 102 from remaining in a braking state due to incomplete reset.

[0044] Detailed Implementation Method Four: See [link] Figures 1-5 As shown, the oil supply system 2 of this embodiment includes a gear pump 201 and a single-path stabilizing diversion valve 202. The oil inlet of the gear pump 201 is connected to the oil tank, and the output port of the gear pump 201 is connected to the oil inlet of the single-path stabilizing diversion valve 202. Port A of the single-path stabilizing diversion valve 202 is the A port of the oil supply system 2, and port B of the single-path stabilizing diversion valve 202 is the B port of the oil supply system 2.

[0045] Specific implementation method five: See Figures 1-5 As shown, the output flow rate of port B of the single-channel stabilizing diverter valve 202 in this embodiment is 15 L / min.

[0046] Furthermore, since the output of the full hydraulic steering gear is positively correlated with its input rotation angle and flow rate, in order to ensure that the left telescopic cylinder 101 and the right telescopic cylinder 102 extend to the same length each time the steering wheel is turned, a single-path stabilizing flow divider valve 202 is used to limit the oil flow rate of the full hydraulic steering gear II 302 to 15L / min.

[0047] Specific implementation method six: See Figures 1-5As shown, in this embodiment, the B port of the single-path stabilizing diversion valve 202 is connected to the overflow valve I 203, and the overflow port of the overflow valve I 203 is connected to the oil return pipe of the oil tank.

[0048] Detailed implementation method seven: See Figures 1-5 As shown, in this embodiment, the output port of the gear pump 201 is connected to an overflow valve II 204, and the overflow port of the overflow valve II 204 is connected to the oil return pipe of the oil tank.

[0049] Furthermore, relief valves I 203 and II 204 are used to maintain a constant system pressure. When the system pressure increases, the relief valves automatically open, allowing excess flow to return to the oil tank to ensure a constant pump outlet pressure.

[0050] Detailed Implementation Method Eight: See also Figures 1-5 As shown, in this embodiment, the control end of the full hydraulic steering gear I 301 is connected to the brake pedal, and the control end of the full hydraulic steering gear II 302 is connected to the steering wheel shaft.

[0051] Furthermore, the use of a steering wheel and brake pedal to control the steering and braking of the tracked loader makes its operation similar to that of conventional vehicles, facilitating user operation. The steering wheel drives a fully hydraulic steering system to supply oil to the brake cylinders. Compared to conventional dual-pedal steering, this allows for a shorter stroke of the brake cylinders to achieve slight braking on one side, enabling the tracked loader to turn at small angles with greater precision.

[0052] Working Principle: Accumulator I 103 is connected to the return ports of the left telescopic cylinder 101 and the right telescopic cylinder 102. When there is no oil pressure at the inlet ports of the left and right telescopic cylinders 101 and 102, accumulator I 103 releases oil to the return ports of the left and right telescopic cylinders 101 and 102, thus resetting them. When the control end of the fully hydraulic steering gear I 301 or II 302 is turned to the left, port A outputs oil proportionally to the angle of rotation of the control end to the left. Port B and port T are connected to form a return oil circuit. The natural return oil flow rate at port B is not controlled by the rotation angle of the control end. When the control ends of the fully hydraulic steering gear I 301 and II 302 are turned to the right, port B outputs oil proportionally to the angle of rotation of the control end to the right. Port A and port T are connected to form a return oil circuit. The natural return oil flow rate at port A is not controlled by the rotation angle of the control end. Check valves I (303), II (304), III (305), and IV (306) are in a flow state from the inlet to the outlet, and in a shut-off state from the outlet to the inlet.

[0053] When the steering wheel is turned to the left, ports A and P of the fully hydraulic steering gear II 302 are connected, and ports B and T are connected. Port A of the fully hydraulic steering gear II 302 outputs hydraulic fluid proportionally to the angle of the steering wheel's leftward rotation. At this time, the normally closed hydraulic control valve 502 is closed, and the normally open hydraulic control valve 4 is open. The hydraulic fluid flows from port A of the fully hydraulic steering gear II 302 into the rodless chamber of the left telescopic cylinder 101, while the hydraulic fluid in the rod chamber of the left telescopic cylinder 101 flows into the accumulator I 103. If the right telescopic cylinder 102 is in the extended state, the hydraulic fluid in the rod chamber of the left telescopic cylinder 101 flows into the rod chamber of the right telescopic cylinder 102, and the hydraulic fluid in the rodless chamber of the right telescopic cylinder 102 flows back from port B of the fully hydraulic steering gear II 302. The right telescopic cylinder 102 retracts, completing the extension of the left telescopic cylinder 101 and the reset of the right telescopic cylinder 102, causing the left track to brake and the right track to move forward, thus achieving leftward steering.

[0054] When the steering wheel is turned to the right, port A and port T of the fully hydraulic steering gear II 302 are connected, and port B and port P are connected. Port B of the fully hydraulic steering gear II 302 outputs hydraulic fluid proportionally to the angle of the steering wheel's rightward rotation. At this time, the normally closed hydraulic control valve 502 is closed, and the normally open hydraulic control valve 4 is open. The hydraulic fluid flows from port B of the fully hydraulic steering gear II 302 into the rodless chamber of the right telescopic cylinder 102, while the hydraulic fluid in the rod chamber of the right telescopic cylinder 102 flows into the accumulator I 103. If the left telescopic cylinder 101 is in the extended state at this time, the hydraulic fluid in the rod chamber of the right telescopic cylinder 102 simultaneously flows into the rod chamber of the left telescopic cylinder 101, and the hydraulic fluid in the rodless chamber of the left telescopic cylinder 101 flows back from port A of the fully hydraulic steering gear II 302. The left telescopic cylinder 101 retracts, completing the extension of the right telescopic cylinder 102 and the reset of the left telescopic cylinder 101, causing the right track to brake and the left track to move forward, thus achieving rightward steering.

[0055] When the brake pedal is depressed, ports A and T of the fully hydraulic steering gear I 301 are connected, and ports B and P are connected. Port B of the fully hydraulic steering gear I 301 outputs hydraulic fluid proportionally to the angle of rotation of the brake pedal to the left. The hydraulic fluid enters the inlet of check valve I 303, the inlet of check valve II 304, and the control terminal of normally open hydraulic control valve 4 through port B of the fully hydraulic steering gear I 301. The hydraulic fluid passes through check valve I 303 and check valve II 304 and enters the rodless chamber of the left telescopic cylinder 101 and the right telescopic cylinder 102. The left telescopic cylinder 101 and the right telescopic cylinder 102 extend simultaneously. Normally open hydraulic control valve 4 closes, cutting off the return oil circuit of the fully hydraulic steering gear II 302, preventing oil from flowing back from the rodless chambers of the left telescopic cylinder 101 and the right telescopic cylinder 102 to the fully hydraulic steering gear II 302. The control function of the fully hydraulic steering gear II 302 fails, ensuring that even if the steering wheel is turned after the brake pedal is pressed, the braking system remains in the braking state, ensuring the stability and priority of the braking action.

[0056] When the brake pedal is released, ports A and P of the fully hydraulic steering gear I 301 are connected, and ports B and T are connected. Port A of the fully hydraulic steering gear I 301 outputs hydraulic fluid proportionally to the change in brake pedal angle. The hydraulic fluid enters accumulator II 501 and normally closed hydraulic control valve 502 from port A of the fully hydraulic steering gear I 301, completing the charging of accumulator II 501 and the opening of normally closed hydraulic control valve 502. At the same time, accumulator I 103 releases hydraulic fluid, which enters the rod chambers of the left telescopic cylinder 101 and the right telescopic cylinder 102. The hydraulic fluid in the rodless chamber of the left telescopic cylinder 101 flows out through check valve IV 306 and enters port B of the fully hydraulic steering gear I 301. The hydraulic fluid in the rodless chamber of the right telescopic cylinder 102 enters port B of the fully hydraulic steering gear I 301 through check valve III 305. The resetting braking effect of the left telescopic cylinder 101 and the right telescopic cylinder 102 disappears. When the brake pedal is fully released, the valve core moves past the center position to the left position, and connects port A and port T to the oil return position. At this time, the oil stored in accumulator II 501 flows back to the oil tank through port A.

[0057] Detailed Implementation Method Nine: See also Figures 6-10 As shown, the tracked vehicle braking device of this embodiment includes a frame, a rear axle box 601, a brake shaft 602, a steering arm 603, a left telescopic cylinder 101, a right telescopic cylinder 102, and a handbrake push rod 604.

[0058] The rear axle housing 601 is fixed to the vehicle frame. Steering arms 603 are fixedly connected to the brake shafts 602 on both sides of the rear axle housing 601. Sliding protrusions 607 are provided on both the upper and lower sides of the steering arms 603. The fixed ends of the left telescopic cylinder 101 and the right telescopic cylinder 102 are hinged to the vehicle frame. The movable ends of the left telescopic cylinder 101 and the right telescopic cylinder 102 are fixed with a lower elongated hole connector 606. The two lower elongated hole connectors 606 are slidably connected to the elongated holes in the sliding protrusions 607 at the lower end of the corresponding steering arms 603. The two handbrake push rods 604 are fixed with upper elongated hole connectors 605. The two upper elongated hole connectors 605 are slidably connected to the elongated holes in the sliding protrusions 607 at the upper end of the corresponding steering arms 603.

[0059] Detailed Implementation Method Ten: See [link / details] Figures 6-10 As shown, in this embodiment, the sliding protrusion 607 at the upper end of the steering arm 603 abuts against the left end of the long hole in the upper long hole connector 605, and the sliding protrusion 607 at the lower end of the steering arm 603 abuts against the right end of the long hole in the lower long hole connector 606.

[0060] Furthermore, brake shafts 602 are provided on both sides of the rear axle housing 601. The rear axle housing 601 includes clutch and brake friction pads, and the brake shafts 602 are used to simultaneously control the clutch and brake friction pads. Braking of the rear axle housing 601 is divided into two stages. In the first stage, the brake shaft 602 rotates, disengaging the clutch from the transmission main shaft in the rear axle housing 601, thus cutting off power. In the second stage, the brake shaft 602 continues to rotate, engaging the brake friction pads, thus decelerating and braking the drive wheels. The braking intensity is adjustable; as the rotation angle of the brake shaft 602 increases, the braking intensity gradually increases, completing single-sided braking. The brake shaft 602 on the left side of the rear axle housing 601 controls the braking of the left drive wheel, and the brake shaft 602 on the right side controls the braking of the right drive wheel. Figure 8 Taking a perspective example, when the steering arm 603 drives the brake shaft 602 to rotate clockwise, single-sided braking is completed; when the brake shaft 602 rotates counterclockwise to reset, the braking ends and the power transmission to the drive wheel is restored. The tracked loader cab is equipped with a handbrake lever, and two handbrake push rods 604 are connected to the handbrake lever. When the handbrake lever is pulled, the handbrake lever simultaneously drives the two handbrake push rods 604 to move to the right, completing the braking action.

[0061] Furthermore, the upper elongated hole connector 605 and the lower elongated hole connector 606 are provided with two plate-like structures, and the steering arm 603 slides between the two plate-like structures. The plate-like structures are provided with elongated slots, and the sliding protrusions 607 on the steering arm 603 are slidably connected in the elongated slots. Taking the left-side braking as an example, when the left telescopic cylinder 101 extends, the right end of the long hole in the lower long hole connector 606 presses against the sliding protrusion 607 located at the lower end of the steering arm 603 and moves to the left, thereby driving the steering arm 603 to rotate clockwise. The steering arm 603 drives the brake shaft 602 to rotate clockwise, completing the braking. At the same time, the sliding protrusion 607 located at the upper end of the steering arm 603 slides to the right in the long hole groove of the upper long hole connector 605, without interfering with the handbrake push rod 604. When the left telescopic cylinder 101 retracts, the brake in the brake shaft 602 drives the brake shaft 602 to rotate counterclockwise, completing the reset of the brake shaft 602 and the steering arm 603. When the handbrake lever 604 moves to the left, the left end of the long hole in the upper long hole connector 605 abuts against the sliding protrusion 607 located at the upper end of the steering arm 603 and moves to the right, thereby causing the steering arm 603 to rotate clockwise. The steering arm 603 causes the brake shaft 602 to rotate clockwise, completing the braking. At the same time, the sliding protrusion 607 located at the lower end of the steering arm 603 slides to the left in the long hole groove of the lower long hole connector 606, without interfering with the left telescopic cylinder 101. When the handbrake lever 604 moves to the right, the brake in the brake shaft 602 causes the brake shaft 602 to rotate counterclockwise, completing the reset of the brake shaft 602 and the steering arm 603.

[0062] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dual-cylinder control system, comprising a left telescopic cylinder (101), a right telescopic cylinder (102) and an accumulator I (103), wherein the oil return ports of the left telescopic cylinder (101) and the right telescopic cylinder (102) are both connected to the accumulator I (103); Its features are: It also includes an oil supply system (2), a fully hydraulic steering gear I (301), a fully hydraulic steering gear II (302), a check valve I (303), a check valve II (304), a check valve III (305), a check valve IV (306), and a time-delay shut-off device (5); Port B of the fully hydraulic steering gear I (301) is connected to the inlet ports of check valve I (303) and check valve II (304). The outlet port of check valve I (303) is connected to the inlet port of the right telescopic cylinder (102) and the inlet port of check valve III (305). The outlet port of check valve II (304) is connected to the inlet port of the left telescopic cylinder (101) and the inlet port of check valve IV (306). The outlet ports of check valve III (305) and check valve IV (306) are connected to port B of the fully hydraulic steering gear I (301) through the actuator of the time-delay closing device (5). The control terminal of the time-delay closing device (5) is connected to the fully hydraulic steering gear I (301). (301) A port is connected, T port of full hydraulic steering gear I (301) is connected to oil tank return pipe, P port of full hydraulic steering gear I (301) is connected to oil supply system (2) A port; A port of full hydraulic steering gear II (302) is connected to one-way valve II (304) outlet and left telescopic cylinder (101) inlet, B port of full hydraulic steering gear II (302) is connected to one-way valve I (303) outlet and right telescopic cylinder (102) inlet, T port of full hydraulic steering gear II (302) is connected to oil tank return pipe, P port of full hydraulic steering gear II (302) is connected to oil supply system (2) B port; It also includes a normally open hydraulic control valve (4), the oil inlet of which is connected to the T port of the fully hydraulic steering gear II (302), the oil outlet of which is connected to the oil tank return pipe, and the control end of which is connected to the B port of the fully hydraulic steering gear I (301). The delayed shut-off device (5) includes an accumulator II (501) and a normally closed hydraulic control valve (502). The actuating end of the delayed shut-off device (5) is the oil inlet and oil outlet of the normally closed hydraulic control valve (502). The oil outlets of check valve III (305) and check valve IV (306) are connected to the oil inlet of the normally closed hydraulic control valve (502). The oil outlet of the normally closed hydraulic control valve (502) is connected to the B port of the fully hydraulic steering gear I (301). The control end of the normally closed hydraulic control valve (502) and the oil inlet of the accumulator II (501) are connected to the A port of the fully hydraulic steering gear I (301).

2. The dual-cylinder control system according to claim 1, characterized in that: The oil supply system (2) includes a gear pump (201) and a single-path stabilizing diverter valve (202). The oil inlet of the gear pump (201) is connected to the oil tank, and the output port of the gear pump (201) is connected to the oil inlet of the single-path stabilizing diverter valve (202). Port A of the single-path stabilizing diverter valve (202) is the A port of the oil supply system (2), and port B of the single-path stabilizing diverter valve (202) is the B port of the oil supply system (2).

3. The dual-cylinder control system according to claim 2, characterized in that: The output flow rate at port B of the single-channel stabilizing diverter valve (202) is 15 L / min.

4. The dual-cylinder control system according to claim 2, characterized in that: The B port of the single-path stabilizing diverter valve (202) is connected to the overflow valve I (203), and the overflow port of the overflow valve I (203) is connected to the oil return pipe of the oil tank.

5. The dual-cylinder control system according to claim 2, characterized in that: The output port of the gear pump (201) is connected to the overflow valve II (204), and the overflow port of the overflow valve II (204) is connected to the oil return pipe of the oil tank.

6. The dual-cylinder control system according to claim 1, characterized in that: The control end of the fully hydraulic steering gear I (301) is connected to the brake pedal, and the control end of the fully hydraulic steering gear II (302) is connected to the steering wheel shaft.

7. A tracked vehicle braking device comprising the dual-cylinder control system according to any one of claims 1-6, characterized in that: Includes a frame, rear axle box (601), brake shaft (602), steering arm (603), left telescopic cylinder (101), right telescopic cylinder (102) and handbrake lever (604); The rear axle housing (601) is fixed on the vehicle frame. Steering arms (603) are fixedly connected to the brake shafts (602) on both sides of the rear axle housing (601). Sliding protrusions (607) are provided on both the upper and lower sides of the steering arms (603). The fixed ends of the left telescopic cylinder (101) and the right telescopic cylinder (102) are hinged to the vehicle frame. The movable ends of the left telescopic cylinder (101) and the right telescopic cylinder (102) are fixed with a lower elongated hole connector (606). The two lower elongated hole connectors (606) are slidably connected to the elongated holes in the sliding protrusions (607) at the lower end of the corresponding steering arms (603). The two handbrake push rods (604) are fixed with upper elongated hole connectors (605). The two upper elongated hole connectors (605) are slidably connected to the elongated holes in the sliding protrusions (607) at the upper end of the corresponding steering arms (603).

8. The tracked vehicle braking device according to claim 7, characterized in that: The sliding protrusion (607) at the upper end of the steering arm (603) abuts against the left end of the long hole in the upper long hole connector (605), and the sliding protrusion (607) at the lower end of the steering arm (603) abuts against the right end of the long hole in the lower long hole connector (606).

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