Tractor with double-pipe trailer hydraulic control system and tractor

Abstract

The present disclosure relates to the field of tractor technology, and particularly relates to a tractor dual-pipeline trailer hydraulic control system and a tractor. The tractor dual-pipeline trailer hydraulic control system of the embodiment of the present disclosure comprises a trailer parking brake, a trailer service brake, a solenoid valve and a pilot valve, the trailer parking brake is used for brake separation under the action of hydraulic oil, the trailer service brake is used for brake braking under the action of hydraulic oil, the solenoid valve is connected with the trailer parking brake to deliver hydraulic oil to the pilot valve or return the hydraulic oil in the trailer service brake, and the pilot valve is connected with the trailer service brake to deliver hydraulic oil to the pilot valve or return the hydraulic oil in the trailer service brake. The tractor dual-pipeline trailer hydraulic control system of the embodiment of the present disclosure improves the flexibility and reliability of brake operation, and improves the overall safety performance in the driving process.

Description

Technical Field

[0001] This disclosure relates to the field of tractor technology, specifically to a hydraulic control system for a tractor-mounted dual-line trailer and the tractor itself. Background Technology

[0002] Tractors, as essential machinery in agriculture, construction, and industry, are frequently used to tow large equipment, trailers, or other attachments. During towing, the control and coordination between the tractor and trailer are crucial. In related technologies, tractor-trailer control systems typically employ a single hydraulic control method or rely on mechanical connections. These methods have numerous limitations when facing complex working conditions or heavy-duty trailers, affecting the overall braking safety and reliability of the machine. Summary of the Invention

[0003] This disclosure aims to at least partially address one of the technical problems in the related art.

[0004] Therefore, embodiments of this disclosure propose a dual-line trailer hydraulic control system for tractors, which improves the flexibility and reliability of braking operation and enhances overall safety performance during operation.

[0005] Embodiments of this disclosure also propose a tractor.

[0006] The hydraulic control system for a tractor-mounted dual-line trailer according to embodiments of this disclosure includes: A trailer parking brake, comprising a first cylinder and a first spring, wherein the inner cavity of the first cylinder is divided into a first rod chamber and a first rodless chamber by a first piston, the first spring is disposed in the first rodless chamber and is used to drive the first piston to move for braking, and the first cylinder is provided with a first interface communicating with the first rod chamber. A trailer service brake, comprising a second cylinder and a second spring, wherein the inner cavity of the second cylinder is divided into a second rod chamber and a second rodless chamber by a second piston, the second spring is disposed in the second rod chamber and is used to drive the second piston to move for brake disengagement, and the second rodless chamber is provided with a second interface; The solenoid valve is provided with a third interface, a fourth interface and a fifth interface. The third interface is connected to the first interface through a pipe. The fourth interface is used for returning hydraulic oil. The fifth interface is used for supplying or returning hydraulic oil. The third interface is used to communicate with the fourth interface or the fifth interface. The pilot valve has a sixth port, a seventh port and an eighth port. The sixth port is connected to the second port through a pipe. The seventh port is used to supply hydraulic oil. The eighth port is used to discharge hydraulic oil. The sixth port is used to communicate with the seventh port or the eighth port.

[0007] The tractor-mounted dual-line trailer hydraulic control system of this embodiment features a trailer parking brake. This allows for pressure delivery to the first rod chamber to drive the first piston, disengaging the brake. Furthermore, by draining hydraulic oil from the first rod chamber, the first piston can be driven to move under the action of a first spring, achieving braking. This system is safe and reliable. In the event of leakage in the pipeline between the trailer parking brake and the solenoid valve, automatic braking is achieved via the first spring. This solves the braking safety problem caused by pressure leakage in the hydraulic pipeline of the trailer parking brake, improving driving safety. The inclusion of a trailer service brake and a pilot valve facilitates the control of hydraulic oil delivery to and drainage from the trailer service brake, enhancing the flexibility and reliability of its operation. By controlling relatively independent hydraulic pipelines for the trailer parking brake and trailer service brake respectively, flexible control of the service and parking brakes is achieved, improving the flexibility and precision of the hydraulic control system in braking operation.

[0008] In some embodiments, the hydraulic control system for a tractor-mounted dual-line trailer also includes a two-position three-way directional valve. The two-position three-way directional valve has a ninth port, a tenth port, and an eleventh port. The ninth port is connected to the fifth port via a pipe. The tenth port is used to return hydraulic oil, and the eleventh port is used to supply hydraulic oil. The ninth port is used to connect to the tenth port or the eleventh port.

[0009] In some embodiments, the two-position three-way directional valve is further provided with a first pilot port, a second pilot port on the left side and a third pilot port on the right side. The first pilot port is connected to the second port via a pipe, the second pilot port is connected to an oil supply pipe, and the third pilot port is connected to a pipe for supplying hydraulic oil during braking.

[0010] In some embodiments, the pilot valve is provided with a fourth pilot port and a fifth pilot port. The fourth pilot port is connected to the second port, and the fifth pilot port is connected to a pipeline for supplying hydraulic oil during braking. The pilot valve is used to connect the sixth port and the seventh port when the oil supply pressure at the fifth pilot port is greater than the oil supply pressure at the fourth pilot port.

[0011] In some embodiments, the tractor-mounted dual-line trailer hydraulic control system further includes a brake pedal and a rear axle brake. The brake pedal is connected to the rear axle brake via a pipe and is used to hydraulically drive the rear axle brake for braking. The fifth pilot interface is connected to the connecting pipe between the brake pedal and the rear axle brake.

[0012] In some embodiments, the tractor-mounted dual-line trailer hydraulic control system further includes a shuttle valve, the brake pedals include a left brake pedal and a right brake pedal, the rear axle brakes include a left rear axle brake and a right rear axle brake, the left brake pedal is connected to the left rear axle brake via a hydraulic oil delivery line, the right brake pedal is connected to the right rear axle brake via a hydraulic oil delivery line, the two input ends of the shuttle valve are respectively connected to the left rear axle brake and the right rear axle brake and select the one with the higher hydraulic oil input pressure to output hydraulic oil, and the first output end of the shuttle valve is connected to the fifth pilot interface.

[0013] In some embodiments, the tractor-mounted dual-line trailer hydraulic control system further includes a front axle control valve and a front axle brake. The front axle control valve includes a twelfth port, a thirteenth port, and a sixth pilot port. The twelfth port is connected to a pipeline for supplying hydraulic oil. The thirteenth port is connected to the front axle brake via a hydraulic oil delivery pipeline. The sixth pilot port is connected to the other output end of the shuttle valve. The front axle control valve is used to connect the twelfth port and the thirteenth port under the action of the hydraulic oil supplied by the sixth pilot port to hydraulically drive the front axle brake for braking.

[0014] In some embodiments, the tractor-mounted dual-line trailer hydraulic control system further includes a first pressure sensor located at the first interface. The first pressure sensor is used to monitor the hydraulic oil supply pressure of the trailer parking brake. The first pressure sensor is electrically connected to a controller, which is electrically connected to the solenoid valve. The controller is used to de-energize the solenoid valve to connect the third and fourth interfaces when the pressure measured by the first pressure sensor is less than a first set value.

[0015] In some embodiments, the tractor-mounted dual-line trailer hydraulic control system further includes a second pressure sensor located at the second interface. The second pressure sensor is used to monitor the hydraulic oil supply pressure of the trailer service brake. The second pressure sensor is electrically connected to a controller, which is electrically connected to an alarm. The controller is used to control the alarm to issue an alarm signal when the pressure measured by the second pressure sensor is less than a second set value.

[0016] The tractors of embodiments of this disclosure include the tractor-mounted dual-line trailer hydraulic control system of any of the above embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the connection of the hydraulic control system for a tractor-mounted dual-line trailer according to an embodiment of the present disclosure during normal vehicle operation.

[0018] Figure 2 This is a schematic diagram of the connection of the hydraulic control system for a tractor-mounted dual-line trailer during parking brake operation, according to an embodiment of this disclosure.

[0019] Figure 3 This is a schematic diagram of the connection of the hydraulic control system for a tractor-mounted dual-line trailer during service braking, according to an embodiment of this disclosure.

[0020] Figure 4 This is a schematic diagram of the connection of the hydraulic supply line of the trailer parking brake in the tractor dual-line trailer hydraulic control system according to an embodiment of the present disclosure when there is a leak.

[0021] Figure 5 This is a schematic diagram of the connection of the hydraulic transmission line of the trailer service brake in the tractor dual-line trailer hydraulic control system according to an embodiment of the present disclosure when there is a leak.

[0022] Figure label: Trailer parking brake 1; first cylinder 101; first spring 102; first interface 103; Trailer service brake 2; second cylinder 201; second spring 202; second interface 203; Solenoid valve 3; Third port 301; Fourth port 302; Fifth port 303; Pilot valve 4; Sixth port 401; Seventh port 402; Eighth port 403; Fourth pilot port 404; Fifth pilot port 405; Hydraulic oil tank 5; Two-position three-way directional valve 6; Ninth port 601; Tenth port 602; Eleventh port 603; First pilot port 604; Second pilot port 605; Third pilot port 606; Hydraulic oil source 7; Brake pedal 8; Left brake pedal 801; Right brake pedal 802; Rear axle brake 9; Left rear axle brake 901; Right rear axle brake 902; Shuttle valve 10; Front axle control valve 11; 12th port 1101; 13th port 1102; 6th pilot port 1103; Front axle brake 12; One-way valve 13; Throttling valve 14; First pressure sensor 15; Second pressure sensor 16. Detailed Implementation

[0023] Embodiments of this disclosure are described in detail below, with examples of these embodiments illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this disclosure, and should not be construed as limiting it.

[0024] The following is a reference appendix. Figures 1 to 5 This disclosure describes a tractor-mounted dual-line trailer hydraulic control system according to embodiments of the present disclosure.

[0025] like Figures 1 to 5 As shown, the hydraulic control system for a tractor-mounted dual-line trailer in an embodiment of this disclosure includes a trailer parking brake 1, a trailer service brake 2, a solenoid valve 3, and a pilot valve 4.

[0026] The trailer parking brake 1 includes a first cylinder 101 and a first spring 102. A first piston moves axially along the first cylinder 101 and is sealed to the first cylinder 101. The inner cavity of the first cylinder 101 is divided into a first rod chamber and a first rodless chamber by the first piston. A first rod is fixedly provided on the first piston. The first rod part is located in the first rod chamber and the end away from the first piston extends out of the first rod chamber. The first spring 102 is located in the first rodless chamber and is used to drive the first piston to move for braking. The first cylinder 101 is provided with a first interface 103 that communicates with the first rod chamber.

[0027] The trailer service brake 2 includes a second cylinder 201 and a second spring 202. A second piston moves axially along the second cylinder 201 and is sealed to the second cylinder 201. The inner cavity of the second cylinder 201 is divided into a second rod chamber and a second rodless chamber by the second piston. A second rod is fixedly provided on the second piston. The second rod is located in the second rod chamber and extends out of the second rod chamber at one end away from the second piston. The second spring 202 is located in the second rod chamber and is used to drive the second piston to move for brake disengagement. The second rodless chamber is provided with a second interface 203.

[0028] The solenoid valve 3 is provided with a third port 301, a fourth port 302 and a fifth port 303. The third port 301 is connected to the first port 103 through a pipe. The fourth port 302 is connected to the hydraulic oil tank 5 through a pipe for hydraulic oil return. The fifth port 303 is used for supplying or returning hydraulic oil. The solenoid valve 3 is used to connect the third port 301 and the fifth port 303 when energized, and to connect the third port 301 and the fourth port 302 when de-energized.

[0029] The pilot valve 4 is provided with a sixth port 401, a seventh port 402 and an eighth port 403. The sixth port 401 is connected to the second port 203 through a pipe. The seventh port 402 is used to supply hydraulic oil, and the eighth port 403 is used to return hydraulic oil. The sixth port 401 is used to communicate with the seventh port 402 or the eighth port 403.

[0030] The working principle of the hydraulic control system for a tractor-mounted dual-line trailer according to the present disclosure is as follows: When the trailer is parked, the handbrake is pulled up, the solenoid valve 3 is de-energized, the third interface 301 and the fourth interface 302 are connected, and the hydraulic oil in the first rod chamber of the first cylinder 101 is discharged back to the hydraulic oil tank 5 through the first interface 103, the third interface 301 and the fourth interface 302. The pressure in the first rod chamber is lost or reduced, and the first spring 102 drives the first piston and the first rod to move to realize the braking of the trailer parking brake 1. When the trailer starts normally, after the tractor is powered on and the vehicle is started, the handbrake is released, the solenoid valve 3 is energized, the third interface 301 and the fifth interface 303 are connected, and the hydraulic oil enters the first rod chamber of the first cylinder 101 through the fifth interface 303, the third interface 301 and the first interface 103. The first rod chamber is pressurized, which drives the first piston to squeeze the first spring 102 and move the first piston to realize the brake separation of the trailer parking brake 1. At this time, the vehicle can drive normally. When braking is applied during trailer travel, the sixth port 401 and the seventh port 402 are connected in the pilot valve 4. Hydraulic oil is delivered to the second rodless chamber of the second cylinder 201 through the pilot valve 4. The second rodless chamber is pressurized, which drives the second piston to squeeze the second spring 202 and move the second piston to achieve braking of the trailer travel brake 2. When a leak occurs in the hydraulic line of the trailer parking brake 1, the hydraulic oil in the first rod chamber of the first cylinder 101 leaks through the first interface 103 at the leak point, causing the first rod chamber to lose pressure or depressurize. The first spring 102 drives the first piston and the first rod to move to achieve braking of the trailer parking brake 1.

[0031] The tractor-mounted dual-line trailer hydraulic control system of this embodiment, by setting a trailer parking brake 1, facilitates the movement of the first piston by supplying pressure to the first rod chamber to disengage the brake. It can also achieve braking by draining hydraulic oil from the first rod chamber and driving the first piston to move under the action of the first spring 102. This is safe and reliable. Furthermore, in the event of leakage in the pipeline between the trailer parking brake 1 and the solenoid valve 3, automatic braking is achieved through the first spring 102, solving the braking safety problem caused by pressure leakage in the hydraulic pipeline of the trailer parking brake 1 and improving driving safety. By setting a trailer service brake 2 and a pilot valve 4, it is easy to control the supply or drainage of hydraulic oil to the trailer service brake 2, improving the flexibility and reliability of operating the trailer service brake 2. The independent hydraulic pipelines of the trailer parking brake 1 and trailer service brake 2, as well as the independent hydraulic pipelines of the trailer parking brake 1 and trailer service brake 2, facilitate flexible control of the service brake and parking brake, improving the flexibility and control accuracy of the hydraulic control system for braking operation.

[0032] In some implementations, such as Figures 1 to 5 As shown, the sixth port 401 of the pilot valve 4 is connected to the hydraulic oil tank 5 through a pipeline, and a pump body is connected between the sixth port 401 and the hydraulic oil tank 5. The pump body is used to transport the hydraulic oil in the hydraulic oil tank 5 to the sixth port 401. The structure is simple and easy to install and control.

[0033] In some implementations, such as Figures 1 to 5 As shown, the hydraulic control system for a tractor-mounted dual-line trailer also includes a two-position three-way directional valve 6. The two-position three-way directional valve 6 is provided with a ninth port 601, a tenth port 602, and an eleventh port 603. The ninth port 601 is connected to the fifth port 303 via a pipeline. The tenth port 602 is used to return hydraulic oil, and the eleventh port 603 is used to supply hydraulic oil. The ninth port 601 is used to connect with the tenth port 602 or the eleventh port 603.

[0034] In this embodiment, by setting a two-position three-way reversing valve 6, it is convenient to control the connection between the ninth interface 601 and the tenth interface 602 or the ninth interface 601 and the eleventh interface 603, thereby facilitating the control operation of supplying hydraulic oil to the fifth interface 303 or draining hydraulic oil through the fifth interface 303. This improves the flexibility and reliability of controlling the trailer parking brake 1 and enhances the safety of the vehicle during operation.

[0035] In some embodiments, the eleventh port 603 is connected to a hydraulic oil source 7 via a pipe, the hydraulic oil source 7 being used to supply hydraulic oil to the eleventh port 603 at a set delivery pressure.

[0036] In some implementations, such as Figures 1 to 5 As shown, the two-position three-way directional valve 6 is also provided with a first pilot port 604 and a second pilot port 605 on the left side and a third pilot port 606 on the right side. The first pilot port 604 is connected to the second port 203 via a pipeline, the second pilot port 605 is connected to the oil supply pipeline, and the third pilot port 606 is connected to a pipeline for supplying hydraulic oil during braking.

[0037] In this embodiment, by setting a second pilot interface 605, when the trailer starts normally, hydraulic oil enters the second pilot interface 605 through the oil supply line to increase the pressure on the left side of the two-position three-way reversing valve 6. The two-position three-way reversing valve 6 switches to the left position, and the ninth interface 601 and the eleventh interface 603 are connected. The hydraulic oil enters the first rod chamber of the first cylinder 101 through the eleventh interface 603, the ninth interface 601, the fifth interface 303, the third interface 301 and the first interface 103. The pressure in the first rod chamber is increased, thereby realizing the brake separation of the trailer parking brake 1. The second pilot port facilitates the adjustment of the reversing of the two-position three-way reversing valve 6, which improves the flexibility and reliability of the control of the trailer parking brake 1 and facilitates the improvement of the safety of the whole vehicle when driving.

[0038] In this embodiment, by setting a first pilot interface 604, when the hydraulic line of the trailer service brake 2 leaks, the hydraulic oil in the second rodless chamber of the second cylinder 201 leaks at the leak point through the second interface 203. The second rodless chamber loses pressure or depressurizes. The second spring 202 drives the second piston and the second rod to move to realize the braking diversion of the trailer parking brake 1, that is, the trailer service brake 2 fails to brake. The pressure on the left side of the two-position three-way reversing valve 6 decreases, and the two-position three-way reversing valve 6 switches to the right position. The ninth interface 601 and the tenth interface 602 are connected. The hydraulic oil in the first rod chamber of the first cylinder 101 is discharged back to the hydraulic oil tank 5 through the first interface 103, the third interface 301, the fifth interface 303, the ninth interface 601 and the tenth interface 602. The first rod chamber loses pressure or depressurizes, thereby realizing the braking of the trailer parking brake 1.

[0039] In this embodiment, the hydraulic lines of the trailer parking brake 1 and the trailer service brake 2 are connected together through the first pilot interface 604 and the second pilot interface 605. When the trailer parking brake 1 and the trailer service brake 2 can be hydraulically controlled separately, leakage in the hydraulic line of the trailer service brake 2 can achieve the switching adjustment of the two-position three-way reversing valve 6, thereby controlling the trailer parking brake 1 to brake. This realizes the linkage control of the trailer parking brake 1 and the trailer service brake 2, solves the braking safety problem caused by leakage in the hydraulic line of the trailer service brake 2, and improves the reliability of the vehicle braking and the safety of the vehicle when leakage occurs in the hydraulic line of the trailer service brake 2.

[0040] In some implementations, such as Figures 1 to 5 As shown, the pilot valve 4 is provided with a fourth pilot port 404 and a fifth pilot port 405. The fourth pilot port 404 is connected to the second port 203, and the fifth pilot port 405 is connected to a pipeline for supplying hydraulic oil during braking. The pilot valve 4 is used to connect the sixth port 401 and the seventh port 402 when the oil supply pressure of the fifth pilot port 405 is greater than the oil supply pressure of the fourth pilot port 404.

[0041] In this embodiment, by setting a fourth pilot interface 404, when the trailer service brake 2 is released, the pressure of the fourth pilot interface 404 is greater than the pressure of the fifth pilot interface 405. The pilot valve 4 switches to the left position, connecting the sixth interface 401 and the eighth interface 403. The hydraulic oil in the second rodless chamber of the second cylinder 201 is discharged back to the hydraulic oil tank 5 through the second interface 203, the sixth interface 401 and the eighth interface 403. The pressure in the second rodless chamber is lost or reduced, thereby realizing the brake separation of the trailer service brake 2.

[0042] In some implementations, such as Figures 1 to 5As shown, the hydraulic control system for the tractor-mounted dual-line trailer also includes a brake pedal 8 and a rear axle brake 9. The brake pedal 8 is connected to the rear axle brake 9 via a pipe and is used to brake the rear axle brake 9 by hydraulically driving it. The fifth pilot interface 405 is connected to the connecting pipe between the brake pedal 8 and the rear axle brake 9.

[0043] In this embodiment, the brake pedal 8 facilitates braking control of the rear axle brake 9, improving driving safety. By connecting the fifth pilot interface 405 to the connecting pipes of the brake pedal 8 and the rear axle brake 9, when the brake pedal 8 is pressed, some hydraulic oil in the connecting pipes of the brake pedal 8 and the rear axle brake 9 reaches the fifth pilot interface 405 through the pipeline, thereby increasing the hydraulic oil at the fifth pilot interface 405. This facilitates the linkage control of the trailer service brake 2 and the rear axle brake 9, improving the convenience of braking operation and the reliability of braking of the entire vehicle.

[0044] In some implementations, such as Figures 1 to 5 As shown, the hydraulic control system for the tractor-mounted dual-line trailer also includes a shuttle valve 10, a brake pedal 8 including a left brake pedal 801 and a right brake pedal 802, and a rear axle brake 9 including a left rear axle brake 901 and a right rear axle brake 902. The left brake pedal 801 is connected to the left rear axle brake 901 through a hydraulic oil delivery pipeline, and the right brake pedal 802 is connected to the right rear axle brake 902 through a hydraulic oil delivery pipeline. The two input ends of the shuttle valve 10 are respectively connected to the left rear axle brake 901 and the right rear axle brake 902, and the valve selects the one with the larger hydraulic oil input pressure to output hydraulic oil. The first output end of the shuttle valve 10 is connected to the fifth pilot interface 405.

[0045] In this embodiment, when braking, the left brake pedal 801 and / or the right brake pedal 802 are pressed. The left brake pedal 801 and / or the right brake pedal 802 drive the hydraulic oil in the corresponding hydraulic oil delivery line to move towards the left rear axle brake 901 and / or the right rear axle brake 902. At the same time, part of the hydraulic oil in the delivery line of the left rear axle brake 901 and / or the right rear axle brake 902 passes through the shuttle valve 10 to the pilot valve 4. By setting the shuttle valve 10, it is convenient to realize the braking by controlling the left rear axle brake 901 and / or the right rear axle brake 902 through the left brake pedal 801 and / or the right brake pedal 802. At the same time, the hydraulic oil output from the left rear axle brake 901 and / or the right rear axle brake 902 with the larger hydraulic oil input pressure can be selected to be delivered to the fifth pilot port 405 of the pilot valve 4 to improve the reliability and stability of braking.

[0046] In some embodiments, the left rear axle brake 901 includes a third cylinder and a third spring. The third piston moves axially along the third cylinder and is sealed to the third cylinder. The inner cavity of the third cylinder is divided into a third rod chamber and a third rodless chamber by the third piston. A third rod is fixedly provided on the third piston. The third rod is located in the third rod chamber and extends out of the third rod chamber at one end away from the third piston. The third spring is located in the third rod chamber and is used to drive the third piston to move for brake release. The third rodless chamber is connected to the hydraulic supply line of the left brake pedal 801 for easy processing and operation.

[0047] In some embodiments, the right rear axle brake 902 includes a fourth cylinder and a fourth spring. The fourth piston moves axially along the fourth cylinder and is sealed to the fourth cylinder. The inner cavity of the fourth cylinder is divided into a fourth rod chamber and a fourth rodless chamber by the fourth piston. A fourth rod is fixedly provided on the fourth piston. The fourth rod is located in the fourth rod chamber and extends out of the fourth rod chamber at one end away from the fourth piston. The fourth spring is located in the fourth rod chamber and is used to drive the fourth piston to move for brake disengagement. The fourth rodless chamber is connected to the hydraulic supply line of the right brake pedal 802 for easy processing and operation.

[0048] In some implementations, such as Figures 1 to 5 As shown, the hydraulic control system for the tractor-mounted dual-line trailer also includes a front axle control valve 11 and a front axle brake 12. The front axle control valve 11 includes a twelfth port 1101, a thirteenth port 1102, and a sixth pilot port 1103. The twelfth port 1101 is connected to a pipeline for supplying hydraulic oil. The thirteenth port 1102 is connected to the front axle brake 12 through a hydraulic oil supply pipeline. The sixth pilot port 1103 is connected to the other output end of the shuttle valve 10. The front axle control valve 11 is used to connect the twelfth port 1101 and the thirteenth port 1102 under the action of the hydraulic oil supplied by the sixth pilot port 1103 to hydraulically drive the front axle brake 12 for braking.

[0049] In this embodiment, when braking, the left brake pedal 801 and / or the right brake pedal 802 are pressed. The left brake pedal 801 and / or the right brake pedal 802 drive the hydraulic oil in the corresponding hydraulic oil delivery pipeline through the shuttle valve 10 and then deliver it to the sixth pilot port 1103 at the other output end of the shuttle valve 10. The pressure of the hydraulic oil in the sixth pilot port 1103 increases, the front axle control valve 11 switches to the left position, and the twelfth port 1101 and the thirteenth port 1102 are connected. The hydraulic oil is delivered to the rear axle brake 9 through the twelfth port 1101 and the thirteenth port 1102, and the rear axle brake 9 performs braking. When the hydraulic oil is pressurized at the sixth pilot port 1103, the front axle control valve 11 switches to the right position, the twelfth port 1101 and the thirteenth port 1102 are disconnected, and the front axle brake 12 discharges hydraulic oil to perform brake separation.

[0050] In this embodiment, by setting a front axle control valve 11 and a front axle brake 12, the number of brakes and the braking position are increased, which facilitates the improvement of the braking reliability of the whole vehicle. The front axle control valve 11 makes it easy to control the front axle brake 12 to achieve front axle braking, which is convenient to operate.

[0051] In some implementations, such as Figures 1 to 5 As shown, there are two front axle brakes 12, which are connected in parallel at the thirteenth interface 1102.

[0052] In some embodiments, the front axle brake 12 includes a fifth cylinder and a fifth spring. The fifth piston moves axially along the fifth cylinder and is sealed to the fifth cylinder. The inner cavity of the fifth cylinder is divided into a fifth rod chamber and a fifth rodless chamber by the fifth piston. A fifth rod is fixedly provided on the fifth piston. The fifth rod is located in the fifth rod chamber and extends out of the fifth rod chamber at one end away from the fifth piston. The fifth spring is located in the fifth rod chamber and is used to drive the fifth piston to move for brake release. The fifth rodless chamber is connected to the thirteenth interface 1102 for easy processing and operation.

[0053] In some implementations, such as Figures 1 to 5 As shown, the third pilot port 606 is connected to the sixth pilot port 1103, and a one-way valve 13 and a throttle valve 14 are connected in parallel on the connecting pipe between the third pilot port 606 and the sixth pilot port 1103. The one-way valve 13 is used to supply hydraulic oil to flow from the third pilot port 606 to the sixth pilot port 1103.

[0054] In this embodiment, by setting a one-way valve 13 and a throttle valve 14 in the third pilot interface 606, the flow rate of hydraulic oil to the third pilot interface is adjusted, thereby achieving the effect of "slow in and fast out" of hydraulic oil, and improving the reliability and stability of the two-position three-way directional valve 6 during directional adjustment.

[0055] In some implementations, such as Figures 1 to 5 As shown, the hydraulic control system for a tractor-mounted dual-line trailer also includes a first pressure sensor 15, which is located at the first interface 103. The first pressure sensor 15 is used to monitor the hydraulic oil supply pressure of the trailer parking brake 1. The first pressure sensor 15 is electrically connected to a controller, which is electrically connected to a solenoid valve 3. The controller is used to de-energize the solenoid valve 3 to connect the third interface 301 and the fourth interface 302 when the pressure measured by the first pressure sensor 15 is less than a first set value.

[0056] In this embodiment, the first pressure sensor 15 is set to facilitate the monitoring of the hydraulic oil supply pressure of the trailer parking brake 1, thereby improving the reliability and safety of the trailer parking brake. Through the electrical connection between the controller and the solenoid valve 3, the solenoid valve 3 can be switched and adjusted when the hydraulic line of the trailer parking brake 1 leaks, so as to reduce the leakage of hydraulic oil in the hydraulic line of the trailer parking brake 1, which is more environmentally friendly.

[0057] In some implementations, such as Figures 1 to 5 As shown, the hydraulic control system for the tractor-mounted dual-line trailer also includes a second pressure sensor 16. The second pressure sensor 16 is located at the second interface 203. The second pressure sensor 16 is used to monitor the hydraulic oil supply pressure of the trailer service brake 2. The second pressure sensor 16 is electrically connected to a controller, and the controller is electrically connected to an alarm. The controller is used to control the alarm to issue an alarm signal when the pressure measured by the second pressure sensor 16 is less than a second set value.

[0058] In this embodiment, the second pressure sensor 16 is set to facilitate the monitoring of the hydraulic oil supply pressure of the trailer service brake 2. The controller and alarm connected by electricity can promptly issue an alarm signal to remind the driver that the hydraulic line of the trailer service brake 2 has leaked, so that the driver can stop the vehicle and perform maintenance in a timely manner, thereby improving the safety and reliability of driving.

[0059] Embodiments of this disclosure also provide a tractor. The tractor of this disclosure includes the dual-line trailer hydraulic control system for tractors of any of the above embodiments. The beneficial effects of the tractor of this disclosure are the same as those of the dual-line trailer hydraulic control system for tractors of the above embodiments, and will not be repeated here.

[0060] In the description of this disclosure, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this disclosure 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. Therefore, they should not be construed as limitations on this disclosure.

[0061] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

[0062] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0063] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0064] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0065] Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A hydraulic control system for a tractor-mounted dual-line trailer, characterized in that, include: A trailer parking brake, comprising a first cylinder and a first spring, wherein the inner cavity of the first cylinder is divided into a first rod chamber and a first rodless chamber by a first piston, the first spring is disposed in the first rodless chamber and is used to drive the first piston to move for braking, and the first cylinder is provided with a first interface communicating with the first rod chamber. A trailer service brake, comprising a second cylinder and a second spring, wherein the inner cavity of the second cylinder is divided into a second rod chamber and a second rodless chamber by a second piston, the second spring is disposed in the second rod chamber and is used to drive the second piston to move for brake disengagement, and the second rodless chamber is provided with a second interface; The solenoid valve is provided with a third interface, a fourth interface and a fifth interface. The third interface is connected to the first interface through a pipe. The fourth interface is used for returning hydraulic oil. The fifth interface is used for supplying or returning hydraulic oil. The third interface is used to communicate with the fourth interface or the fifth interface. The pilot valve has a sixth port, a seventh port and an eighth port. The sixth port is connected to the second port through a pipe. The seventh port is used to supply hydraulic oil. The eighth port is used to discharge hydraulic oil. The sixth port is used to communicate with the seventh port or the eighth port.

2. The hydraulic control system for a tractor-mounted dual-line trailer according to claim 1, characterized in that, The tractor-mounted dual-line trailer hydraulic control system also includes a two-position three-way reversing valve. The two-position three-way reversing valve has a ninth port, a tenth port, and an eleventh port. The ninth port is connected to the fifth port via a pipeline. The tenth port is used to return hydraulic oil, and the eleventh port is used to supply hydraulic oil. The ninth port is used to connect with the tenth port or the eleventh port.

3. The hydraulic control system for a tractor-mounted dual-line trailer according to claim 2, characterized in that, The two-position three-way directional valve is also provided with a first pilot port and a second pilot port on the left side and a third pilot port on the right side. The first pilot port is connected to the second port via a pipeline, the second pilot port is connected to the oil supply pipeline, and the third pilot port is connected to a pipeline for supplying hydraulic oil during braking.

4. The hydraulic control system for a tractor-mounted dual-line trailer according to claim 1, characterized in that, The pilot valve is provided with a fourth pilot port and a fifth pilot port. The fourth pilot port is connected to the second port, and the fifth pilot port is connected to a pipeline for supplying hydraulic oil during braking. The pilot valve is used to connect the sixth port and the seventh port when the oil supply pressure at the fifth pilot port is greater than the oil supply pressure at the fourth pilot port.

5. The hydraulic control system for a tractor-mounted dual-line trailer according to claim 4, characterized in that, The tractor-mounted dual-line trailer hydraulic control system also includes a brake pedal and a rear axle brake. The brake pedal is connected to the rear axle brake via a pipe and is used to brake the rear axle brake hydraulically. The fifth pilot interface is connected to the connecting pipe of the brake pedal and the rear axle brake.

6. The hydraulic control system for a tractor-mounted dual-line trailer according to claim 5, characterized in that, The tractor-mounted dual-line trailer hydraulic control system also includes a shuttle valve. The brake pedals include a left brake pedal and a right brake pedal. The rear axle brakes include a left rear axle brake and a right rear axle brake. The left brake pedal is connected to the left rear axle brake via a hydraulic oil delivery line, and the right brake pedal is connected to the right rear axle brake via a hydraulic oil delivery line. The two input ends of the shuttle valve are respectively connected to the left rear axle brake and the right rear axle brake, and the valve selects the one with the higher hydraulic oil input pressure to output hydraulic oil. The first output end of the shuttle valve is connected to the fifth pilot interface.

7. The hydraulic control system for a tractor-mounted dual-line trailer according to claim 6, characterized in that, The tractor-mounted dual-line trailer hydraulic control system also includes a front axle control valve and a front axle brake. The front axle control valve includes a twelfth port, a thirteenth port, and a sixth pilot port. The twelfth port is connected to a pipeline for supplying hydraulic oil. The thirteenth port is connected to the front axle brake via a hydraulic oil delivery pipeline. The sixth pilot port is connected to the other output end of the shuttle valve. The front axle control valve is used to connect the twelfth port and the thirteenth port under the action of the hydraulic oil supplied by the sixth pilot port to hydraulically drive the front axle brake for braking.

8. The hydraulic control system for a tractor-mounted dual-line trailer according to any one of claims 1-7, characterized in that, The tractor-mounted dual-line trailer hydraulic control system further includes a first pressure sensor located at the first interface. The first pressure sensor is used to monitor the hydraulic oil supply pressure of the trailer parking brake. The first pressure sensor is electrically connected to a controller, which is electrically connected to the solenoid valve. The controller is used to de-energize the solenoid valve to connect the third and fourth interfaces when the pressure measured by the first pressure sensor is less than a first set value.

9. The hydraulic control system for a tractor-mounted dual-line trailer according to any one of claims 1-7, characterized in that, The tractor-mounted dual-line trailer hydraulic control system also includes a second pressure sensor located at the second interface. The second pressure sensor is used to monitor the hydraulic oil supply pressure of the trailer's service brake. The second pressure sensor is electrically connected to a controller, which is electrically connected to an alarm. The controller is used to control the alarm to issue an alarm signal when the pressure measured by the second pressure sensor is less than a second set value.

10. A tractor, characterized in that, Includes the tractor-mounted dual-line trailer hydraulic control system as described in any one of claims 1-9.

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