Intelligent trailer system of hydrostatic vehicle and control method

Abstract

The invention relates to a hydrostatic vehicle intelligent trailer system and a control method, the hydrostatic vehicle intelligent trailer system comprises at least two groups of closed high-pressure loops, and each group of closed high-pressure loops comprises a walking pump, a walking motor and a hydraulic control reversing valve; the hydraulic control reversing valves of the two closed high-pressure loops are connected through a pipeline, a stop valve and a trailer valve are arranged on the pipeline, the other end of the stop valve is connected with a brake clutch through a pipeline, the brake clutch is connected with an oil supplementing mechanism through a pipeline, and a manual pump, an automatic pump and a trailer reversing valve are integrated in the trailer valve. According to the trailer environment and the trailer distance, a manual mode or an automatic mode can be autonomously adopted to relieve the braking resistance of the hydrostatic walking system, in the trailer process, the system has a braking low-pressure early warning function, the rotating speed of a motor can be automatically adjusted, internal leakage of a control valve and a clutch can be compensated according to the braking pressure requirement, and smooth trailer operation is guaranteed; the brake is prevented from being damaged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engineering machinery, in particular to a static hydraulic vehicle intelligent trailer system and a control method. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] The walking system of static hydraulic engineering vehicles such as push-loading machines and static hydraulic bulldozers is a closed system, which is composed of two independent closed systems through a pump and a motor. In the process of whole machine operation, if a major failure occurs and the construction site cannot be repaired, the vehicle needs to be transported to a repair point for failure disposal, or the failed vehicle is directly towed back to the repair point.

[0004] Since the static hydraulic walking system adopts a normally closed brake, the brake needs to be released to realize towing. In addition, during towing, the motor of the closed system will drag the pump and engine, increasing the difficulty of towing. Therefore, before towing, the high-pressure pipelines on both sides need to be connected to reduce the resistance caused by the closed system.

[0005] The brake of the static hydraulic vehicle is small in size and has a leakage that is not easy to detect. The internal leakage of various control valves in the system also exists. The leakage (brake, control valve, etc.) will cause the pressure of the closed system to be unable to be maintained, further increasing the difficulty of towing. In order to ensure smooth towing, the system needs to compensate for the leakage in time to maintain the stable pressure of the system. SUMMARY

[0006] In order to solve the technical problems in the background art, the present application provides a static hydraulic vehicle intelligent towing system and a control method, which can autonomously decide to use manual or automatic mode to release the braking resistance of the static hydraulic walking system according to the towing environment and towing distance. During towing, the system has a brake low-pressure warning function, can automatically adjust the motor speed according to the brake pressure demand, compensate for the internal leakage of the control valve and clutch, ensure smooth towing, and avoid damaging the brake.

[0007] In order to achieve the above purpose, the present application adopts the following technical solutions: The first aspect of the present application provides a static hydraulic vehicle intelligent towing system, which comprises at least two groups of closed high-pressure circuits, each of which comprises a walking pump, a walking motor and a hydraulic control reversing valve. The hydraulic control reversing valves of the two groups of closed high-pressure circuits are connected through a pipeline, the pipeline is provided with a stop valve and a towing valve, the other end of the stop valve is connected to a brake clutch through a pipeline, the brake clutch is connected to an oil supplementing mechanism through a pipeline, and the towing valve is integrated with a manual pump, an automatic pump and a towing reversing valve.

[0008] Further, the oil supplement mechanism comprises a one-way valve, a brake solenoid valve, an oil supplement pump and an oil tank connected in sequence through pipelines.

[0009] Further, a filter is arranged on the pipeline between the brake solenoid valve and the oil supplement pump.

[0010] Further, in the closed high-pressure circuit, the traveling pump, the traveling motor and the hydraulic control reversing valve are connected in parallel, and the hydraulic control reversing valve has an oil discharge port and a pilot end.

[0011] Further, in the two groups of closed high-pressure circuits, the pilot ends of the hydraulic control reversing valves are connected through a pipeline, and the pipeline is connected to the A end of the stop valve.

[0012] Further, the A end of the stop valve is connected to the M port of the trailer valve through a pipeline.

[0013] Further, the B end of the stop valve is connected to the brake clutch through a pipeline.

[0014] Further, a sensor is further arranged to obtain the pressure in the pipeline between the stop valve and the brake clutch.

[0015] Further, a controller is further arranged to communicate with the automatic pump in the trailer valve; in the automatic mode, when the pressure obtained by the sensor is lower than a set value, the controller sends a command to the automatic pump to increase the rotating speed until the pressure obtained by the sensor is not lower than the set value, and the automatic pump returns to the initial rotating speed.

[0016] The second aspect of the present application provides a control method of the hydrostatic vehicle intelligent trailer system, comprising the following steps: Before the trailer is towed by the traction force, the stop valve is opened, the brake solenoid valve in the oil supplement mechanism is closed, the manual pump or the automatic pump in the trailer valve is actuated, the pressure oil is output from the M port, one way is to enter the brake clutch after passing through the stop valve, and the brake is contacted; the other way is to enter the pilot end of the hydraulic control reversing valve to drive the hydraulic control reversing valve to open, and the two groups of closed high-pressure circuits are conducted between them. When the pressure obtained by the sensor exceeds the set value, a prompt signal is sent, the manual pump or the automatic pump in the trailer valve is stopped, and the trailer is allowed to be towed. In the manual mode, when the pressure obtained by the sensor is lower than the set value, an alarm signal is sent to prompt the operator to start the manual pump in the trailer valve to compensate for the pressure drop caused by the leakage. In the automatic mode, the pressure obtained by the sensor is sent to the controller, and when the pressure is lower than the set value, the controller outputs a signal to the automatic pump in the trailer valve to gradually increase the rotating speed to compensate for the pressure drop caused by the leakage until the pressure obtained by the sensor is not lower than the set value, and the automatic pump returns to the initial rotating speed.

[0017] Compared with the prior art, the above one or more technical solutions have the following beneficial effects: 1. The trailer valve is connected between two closed high-pressure circuits independent of each other, and a leakage compensation mechanism is formed by using the integrated manual pump, automatic pump and trailer reversing valve in the trailer valve, combined with the obtained system pressure, to ensure the pressure stability during the trailer.

[0018] 2. Compared with the traditional trailer period, the two closed systems are connected by an additional high-pressure pipeline, and the oil control reversing valve is connected to the pilot end. With closed-loop control, the trailer process can be simplified (such as quick release of the brake and reduction of system resistance), and the pressure stability during the trailer is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings accompanying the specification of this application form a part thereof, serve to further provide a further understanding of the application, and together with the description of the exemplary embodiments of the application, serve to explain the application, and do not constitute an improper limitation of the application.

[0020] Figure 1 is a schematic diagram of an intelligent trailer system for a hydrostatic vehicle provided by one or more embodiments of the application; Figure 2 is a schematic diagram of a trailer valve provided by one or more embodiments of the application.

[0021] In the figure: 1 oil tank, 2 oil supplement pump, 3 filter, 4 brake solenoid valve, 5 trailer valve, 6 load valve, 7 controller, 8 sensor, 9 check valve, 10 right walking pump, 11 right walking motor, 12 left walking pump, 13 left walking motor, 14 right hydraulic control reversing valve, 15 left hydraulic control reversing valve, 16 right brake clutch, 17 left brake clutch. DETAILED DESCRIPTION

[0022] The application will be further described below in conjunction with the drawings and embodiments.

[0023] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the application belongs.

[0024] It should be noted that the terms used herein are only for the purpose of describing the specific embodiments and are not intended to limit the exemplary embodiments according to the application. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form, and in addition, it should be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or combination thereof.

[0025] Terminology: Closed Circuit Hydraulic System, a kind of hydraulic transmission system, its characteristic is that hydraulic oil forms a closed circulation loop between the pump and the motor (or oil cylinder), and the oil does not directly return to the oil tank, but circulates inside the system.

[0026] The working principle of the closed system is as follows: the variable pump drives the hydraulic motor, high pressure oil flows from the pump outlet to the motor, and low pressure oil returns from the motor to the inlet of the pump, forming a closed circulation. By changing the angle of the swash plate of the pump (displacement) and direction, the speed and direction of the motor can be controlled. The oil supply pump continuously supplies oil to the low pressure side to compensate for leakage and cool the system.

[0027] The characteristics of the closed system are as follows: Structural closure. The pump and motor form an independent circulation loop, and the hydraulic oil circulates inside, without the need for frequent oil replenishment (compared with open system).

[0028] Energy transmission bidirectionality. The motor can be reversed to become a "pump working condition", and the engine can be reversed (when towing, the pipeline needs to be connected to avoid this phenomenon).

[0029] Braking relies on hydraulic pressure. Normally closed brake needs to be released by system pressure; leakage will cause pressure drop, which may cause accidental braking.

[0030] High precision and high efficiency. Suitable for continuous speed regulation and frequent direction change scenes (such as bulldozer walking system), but the maintenance complexity is high.

[0031] Sensitive to leakage. Small leakage may cause pressure instability, and additional compensation devices (such as accumulators or oil supply pumps) are needed.

[0032] As introduced in the background art, the static hydraulic engineering vehicle has the problem of towing difficulty, because it is a normally closed brake, which needs to be manually released to tow. When towing, the motor reverses the pump and engine (due to the mechanical linkage of the closed system), resulting in increased resistance. At the same time, the leakage in the system (brake, control valve, etc.) will cause the pressure to be unable to maintain, further increasing the difficulty of towing.

[0033] When the static hydraulic engineering vehicle breaks down, the existing solution has limitations: the faulty vehicle needs to be transported to the repair point, but before towing, the high pressure pipeline on both sides needs to be connected (to avoid the motor reversing the pump), and the system leakage needs to be continuously compensated (to maintain stable pressure and prevent accidental brake clamping).

[0034] Therefore, the following embodiments give a kind of static hydraulic vehicle intelligent towing system and control method, which solves the core problems of how to simplify the towing process (such as quickly releasing the brake, reducing system resistance), and how to design a leakage compensation mechanism to ensure stable pressure when towing.

[0035] Embodiment one: A hydrostatic vehicle intelligent trailer system, comprising an oil tank 1, an oil supplement pump 2, a filter 3, a brake solenoid valve 4, a trailer valve 5, a stop valve 6, a controller 7, a sensor 8, a one-way valve 9, a right walking pump 10, a right walking motor 11, a left walking pump 12, a left walking motor 13, a right hydraulic control reversing valve 14, a left hydraulic control reversing valve 15, a right brake clutch 16, a left brake clutch 17 and the like elements. It is divided into two implementation modes of manual mode and automatic mode.

[0036] As shown in Figure 1 The oil tank 1 is connected to the oil supplement pump 2, the filter 3 and the inlet of the brake solenoid valve 4 in sequence through pipes, the outlet of the brake solenoid valve 4 is connected to the right brake clutch 16 and the left brake clutch 17 through pipes respectively via the one-way valve 9, and the pipes are provided with the sensor 8 which is in communication connection with the controller 7.

[0037] The right walking pump 10, the right walking motor 11 and the right hydraulic control reversing valve 14 form a group of closed high-pressure circuits, the left walking pump 12, the left walking motor 13 and the left hydraulic control reversing valve 15 form another group of closed high-pressure circuits, and the two groups of high-pressure circuits are independent of each other.

[0038] As a further implementation mode, the trailer valve 5 is connected to the oil tank 1 through pipes for oil supplement during the trailer.

[0039] As a further implementation mode, the brake solenoid valve 4 is also connected to the oil return port (T port) of the oil tank 1 through pipes, when the brake solenoid valve is powered off, the outlet of the brake solenoid valve 4 is in communication with the T port to return hydraulic oil to the oil tank 1 to release pressure, and when the brake solenoid valve 4 is powered on, it is opened and the outlet of the brake solenoid valve 4 is in communication with the oil inlet port.

[0040] The reversing valves in the two groups of closed high-pressure circuits are connected through pipes, the pipes are connected to the A end of the stop valve 6, the pipes are provided with the trailer valve 5, and the B end of the stop valve 6 is connected to the right brake clutch 16 and the left brake clutch 17 through pipes. Specifically, the walking pump, the walking motor and the hydraulic control reversing valve in the high-pressure circuit are connected in parallel, and the hydraulic control reversing valve also has a unloading port and a pilot end. The pilot ends of the right hydraulic control reversing valve 14 and the left hydraulic control reversing valve 15 are connected through pipes, and the pipes are connected to the A end of the stop valve 6.

[0041] The A end of the stop valve 6 is connected to the trailer valve 5 through pipes, and the manual pump and the electric pump are integrated in the trailer valve 5. The two independent closed high-pressure circuits are connected in series by using the hydraulic control reversing valve, when the short-distance trailer is needed, the trailer valve 5 can be manually or automatically controlled, and when the long-distance trailer is needed, the automatic control is adopted.

[0042] The functions of the above elements are as follows: The oil supplement pump 2 provides initial pressure oil to ensure that the brake system and the hydraulic control valve pilot pressure are stable.

[0043] Filter 3: Protect the system from pollution, prolong the life of the valve.

[0044] One-way valve 9: Prevents brake clutch (16, 17) pressure oil backflow, maintains brake release state.

[0045] Sensor 8: Real-time monitoring of brake pressure, triggering low pressure alarm or automatic pressure compensation.

[0046] Brake solenoid valve 4: When de-energized, the outlet is connected to the tank (oil tank), the brake pressure is released, and the brake resistance is removed. When energized, the outlet is connected to the oil inlet (P port), providing pressure to the brake, and locking during normal driving.

[0047] Brake clutch (16, 17): When towing, the brake is released by pressure oil to avoid mechanical friction loss.

[0048] Towing valve 5: Integrates manual pump (short distance emergency) and electric pump (long distance automatic control) to adapt to different scenarios. Provides pressure oil to the pilot chamber of the hydraulic directional control valve to ensure that the high-pressure circuit is connected during towing.

[0049] Stop valve 6: Controls the connection and disconnection of the towing valve 5 and the pilot chamber of the hydraulic directional control valve (14, 15), determining whether to enable the towing mode.

[0050] Hydraulic directional control valve (14, 15): During normal driving, the direction of the motor (11, 13) is controlled by the traveling pump (10, 12). When towing, the pilot chamber pressure oil makes it switch to a series state, allowing the two high-pressure circuits to communicate, avoiding resistance caused by motor pumping effect.

[0051] Traveling pump / motor (10-13): When towing, the hydraulic control valve bypasses to prevent the motor from being passively rotated and damaging the system.

[0052] Before applying traction to tow the trailer, the towing system needs to be started, the stop valve 6 is opened, the brake solenoid valve 4 is de-energized to release pressure, and the manual or electric pump in the towing valve 5 works. Pressure oil from the oil tank 1 enters the brake (16, 17) and the pilot chamber of the hydraulic directional control valve (14, 15), the brake and the hydraulic directional control valve are opened, and the two independent closed high-pressure circuits are connected, avoiding power reverse transmission during towing. Due to the leakage of the clutch and the respective valve body, the brake pressure gradually decreases during towing. When the brake pressure detected by the sensor 8 decreases to the critical pressure, the low pressure alarm light flashes. In manual mode, the alarm light prompts the operator to operate the manual pump to supply oil to the system; in automatic mode, the sensor 8 feeds back the detected critical pressure value to the controller 7, and the controller 7 gradually increases the motor speed, the pump output flow increases, compensates for internal leakage, until the brake pressure reaches the highest set value. At this time, the high pressure alarm light flashes, and then the control motor speed decreases to the initial speed.

[0053] After the trailer ends, stop the manual or electric pump, pull out the trailer valve stem, the low-pressure alarm light flashes, stay for more than 2 minutes, close the stop valve.

[0054] In this embodiment: 1When two independent closed high-pressure circuits are connected respectively, the power reverse transmission during towing can be avoided. The present scheme realizes the connection between the two closed high-pressure circuits through the trailer valve 5.

[0055] 2Due to the clutch and the internal leakage of each valve body, the brake pressure will gradually decrease during towing.

[0056] 3When the brake pressure decreases to the critical pressure, the low-pressure alarm light will flash: In manual mode: the alarm light prompts the operator to operate the manual pump to supply oil to the system.

[0057] In automatic mode: the sensor feeds back the detected critical pressure value to the controller, and the controller gradually increases the motor speed, and the pump output flow increases to compensate for internal leakage, until the brake pressure reaches the highest set value (at this time the high-pressure alarm light flashes), and then the control motor speed decreases to the initial speed.

[0058] When towing at close range, manual and minimum selection are convenient and flexible; when towing at a long distance, electric control mode is safe and reliable.

[0059] An internal leakage compensation mechanism is proposed, which automatically adjusts the motor speed through pressure feedback, solving the brake failure problem caused by internal leakage in traditional towing systems. The closed-loop control used can effectively compensate for the internal leakage of the clutch and valve body, improve the towing efficiency, and effectively protect the core components such as the friction plate.

[0060] A trailer valve is connected between two closed high-pressure circuits independent of each other, and a manual pump, an automatic pump, and a trailer reversing valve are integrated in the trailer valve to form a dual-mode redundant design, and a leakage compensation mechanism is formed by obtaining the system pressure to ensure stable pressure during towing.

[0061] Compared with the traditional towing period, the method of connecting two closed systems with an additional high-pressure pipeline can simplify the towing process (such as quickly releasing the brake and reducing system resistance) by pre-designing the oil circuit for connection inside the engineering vehicle and connecting the pilot end of the hydraulic control reversing valve, and ensuring stable pressure during towing.

[0062] Through intelligent control, hydraulic compensation, and redundant design, this system effectively solves problems encountered by hydrostatically driven vehicles during towing, such as high braking resistance, insufficient pressure due to internal system leakage, and poor adaptability to towing modes. It can automatically select manual or automatic control based on the towing distance (short / long), improving adaptability. Sensors monitor brake pressure in real time; when internal leakage causes insufficient pressure, the system automatically adjusts the motor speed to compensate for the pressure, preventing brake damage. The brake solenoid valve automatically releases pressure (return oil at port T) when de-energized, ensuring no braking resistance in the initial state of the trailer.

[0063] Example 2: A control method for a hydrostatic intelligent trailer system includes the following steps: Before applying traction to the trailer, the shut-off valve opens, the brake solenoid valve in the oil replenishment mechanism closes, the manual or automatic pump in the trailer valve is activated, and the pressurized oil is output from port M. One path passes through the shut-off valve and enters the brake clutch, where the brakes are engaged; the other path enters the pilot end of the hydraulic directional valve, driving the hydraulic directional valve to open, and the two sets of closed high-pressure circuits are connected. If the pressure detected by the sensor exceeds the set value, a warning signal is issued, and the manual or automatic pump in the trailer valve stops, allowing the trailer to be towed. In manual mode, if the pressure detected by the sensor is lower than the set value, an alarm signal will be issued, prompting the operator to start the manual pump in the trailer valve to compensate for the pressure drop caused by leakage. In automatic mode, the pressure acquired by the sensor is sent to the controller. When the pressure is lower than the set value, the controller sends a signal to the automatic pump in the trailer valve to gradually increase the speed to compensate for the pressure drop caused by leakage, until the pressure acquired by the sensor is not lower than the set value, and the automatic pump returns to the initial speed.

[0064] In this embodiment, the trailer valve 5 integrates a manual pump, an electric pump, a shuttle valve, a check valve, an overflow valve, and a trailer directional valve. The specific structure is not limited; this embodiment uses the following... Figure 2 The trailer valve shown is an example. It can use a manual or electric pump to pump the pressurized oil in tank 1 to the output port M, and return the excess pressurized oil to tank 1 after the trailer is finished. The shuttle valve, check valve, overflow valve, and trailer directional valve can be configured according to the specific oil circuit.

[0065] Combination Figure 1 The given system structure is as follows: the oil tank 1 is connected to the inlet of the oil replenishment pump 2, the filter 3 and the brake solenoid valve 4 in sequence through the pipeline. The outlet of the brake solenoid valve 4 is connected to the right brake clutch 16 and the left brake clutch 17 respectively through the pipeline and the one-way valve 9. The pipeline is equipped with a sensor 8, which is connected to the controller 7 for communication.

[0066] The right traveling pump 10, the right traveling motor 11 and the right hydraulic control reversing valve 14 form a closed high pressure circuit, the left traveling pump 12, the left traveling motor 13 and the left hydraulic control reversing valve 15 form another closed high pressure circuit, and the two high pressure circuits are independent of each other.

[0067] The reversing valves in the two closed high pressure circuits are connected through a pipeline connected to the A end of the stop valve 6, and the pipeline is provided with the trailer valve 5, and the B end of the stop valve 6 is connected to the right brake clutch 16 and the left brake clutch 17 through a pipeline.

[0068] The A end of the stop valve 6 is connected to the trailer valve 5 through a pipeline, and the manual pump and the electric pump are integrated in the trailer valve 5. The hydraulic control reversing valves are connected in series between the two independent closed high pressure circuits, and when a short distance trailer is needed, the trailer valve 5 can be manually or automatically controlled, and when a long distance trailer is needed, automatic control is adopted.

[0069] Taking the automatic mode as an example: Before the trailer is pulled by the traction force, the trailer reversing valve is actuated, the stop valve 6 is opened, the brake solenoid valve 4 is de-energized and closed, the electric pump is energized and works, and the pressure oil from the oil tank 1 is output through the M port of the trailer valve 5 and is divided into two paths: One path enters the right brake clutch 16 and the left brake clutch 17 after passing through the stop valve 6, and the two brake clutches are filled with oil, and the left and right brakes are released; The other path enters the left hydraulic control reversing valve 15 and the right hydraulic control reversing valve 14 into the pilot end, respectively, so that the left and right hydraulic control reversing valves are opened, and the left and right independent high pressure circuits are conducted. When the sensor 8 detects that the pressure in the system reaches the set value, the whole vehicle pressure signal light is turned on, prompting the operator to pull the trailer, and the electric pump stops working.

[0070] During the trailer pulling process, the clutches and the respective valve bodies leak, and the brake pressure gradually decreases. When the brake pressure decreases to the critical pressure, the low pressure alarm light flashes. The sensor 8 feeds back the detected critical pressure value to the controller 7, the controller 7 outputs a signal to gradually increase the motor speed, the electric pump starts to output flow, compensates for the internal leakage, and the brake pressure reaches the highest set value. At this time, the high pressure alarm light flashes, and then the electric pump is stopped, the trailer reversing valve rod is pulled out, the low pressure alarm light flashes, and stays for more than 2 minutes, and the stop valve is closed. After the trailer pulling is finished, the electric pump is stopped, the trailer reversing valve rod is pulled out, the low pressure alarm light flashes, and stays for more than 2 minutes, and the stop valve is closed. The manual operation mode is similar to the automatic mode in control strategy, except that the power source is changed to manual operation, and the operation needs to be performed according to the indicator light prompt.

[0071] In this embodiment, the function of the trailer reversing valve is to switch the flow direction of the pressure oil in the trailer valve 5, so that the pressure oil in the oil tank 1 can flow into the trailer valve 5, and then be driven by the electric pump or the manual pump, or the pressure oil can return to the oil tank from the trailer valve 5. The specific oil circuit arrangement is mature prior art, and the present scheme is not limited.

[0072] In this embodiment, the working principle of the hydraulic control reversing valve is as follows: after the trailer valve sends the pressure oil to the pilot chamber, the spring force is overcome, the valve core is pushed to move, and the hydraulic control reversing valve is connected.

[0073] In this embodiment, the trailer valve 5 has a C port for connecting with the sensor 8 to obtain the oil pressure.

[0074] In the above method, by connecting the trailer valve between two independent closed high-pressure circuits, using the manual pump, automatic pump and trailer reversing valve integrated in the trailer valve, a double-mode redundant design is formed, and a leakage compensation mechanism is formed by combining the obtained system pressure, to ensure the stability of the pressure during towing.

[0075] Compared with the traditional towing period, the method of connecting two closed systems through an additional high-pressure pipeline is designed in advance in the engineering vehicle to guide the oil circuit, and the pilot end of the hydraulic control reversing valve is connected, which can simplify the towing process (such as quickly releasing the brake and reducing system resistance) and ensure the stability of the pressure during towing.

[0076] Through intelligent control, hydraulic compensation and redundant design, the problems of large brake resistance, insufficient pressure caused by internal leakage, poor adaptability of the towing mode and the like of the hydrostatic drive vehicle during towing are effectively solved, the manual or automatic control can be automatically selected according to the towing distance (short / long), the adaptability is improved, the brake pressure is monitored in real time by using the sensor, the motor speed is automatically adjusted to compensate the pressure when the pressure is insufficient due to internal leakage, and the brake damage is avoided. When the brake solenoid valve is powered off, the pressure is automatically released (T port returns oil), and the initial state without brake resistance during towing is ensured.

[0077] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A hydrostatic vehicle intelligent trailer system, characterized by, The closed high-pressure circuit comprises at least two groups of closed high-pressure circuits, each of which comprises a traveling pump, a traveling motor and a hydraulic control reversing valve. The hydraulic control reversing valves of the two groups of closed high-pressure circuits are connected by a pipeline, the pipeline is provided with a stop valve and a trailer valve, the other end of the stop valve is connected to a brake clutch through a pipeline, the brake clutch is connected to an oil supplementing mechanism through a pipeline, and the trailer valve is integrated with a manual pump, an automatic pump and a trailer reversing valve.

2. A hydrostatic vehicle intelligent trailer system as claimed in claim 1, characterized in that, The oil supplementing mechanism comprises a one-way valve, a brake electromagnetic valve, an oil supplementing pump and an oil tank connected in sequence through pipelines.

3. A hydrostatic vehicle intelligent trailer system as claimed in claim 2, characterized in that, A filter is arranged on the pipeline between the brake electromagnetic valve and the oil supplementing pump.

4. A hydrostatic vehicle intelligent trailer system as in claim 1, wherein, In the closed high-pressure circuit, the traveling pump, the traveling motor and the hydraulic control reversing valve are connected in parallel, and the hydraulic control reversing valve has an oil discharge port and a pilot end.

5. A hydrostatic vehicle intelligent trailer system as claimed in claim 4, characterized in that, In the two groups of closed high-pressure circuits, the pilot ends of the hydraulic control reversing valves are connected by a pipeline, and the pipeline is connected to the A end of the stop valve.

6. A hydrostatic vehicle intelligent trailer system as claimed in claim 5, characterized in that The A end of the stop valve is connected to the M port of the trailer valve through a pipeline.

7. A hydrostatic vehicle intelligent trailer system as claimed in claim 5, wherein, The B end of the stop valve is connected to the brake clutch through a pipeline.

8. A hydrostatic vehicle intelligent trailer system as in claim 1, wherein, A sensor is further arranged to obtain the pressure in the pipeline between the stop valve and the brake clutch.

9. A hydrostatic vehicle intelligent trailer system as in claim 1, wherein, A controller is further arranged in communication with the sensor and the automatic pump in the trailer valve; in the automatic mode, when the pressure obtained by the sensor is lower than a set value, the controller sends a command to the automatic pump to increase the rotating speed until the pressure obtained by the sensor is not lower than the set value, and the automatic pump returns to the initial rotating speed.

10. Control method of the hydrostatic vehicle intelligent trailer system according to any one of claims 1-9, characterized in that, The method comprises the following steps: Before the trailer is pulled, the stop valve is opened, the brake electromagnetic valve in the oil supplementing mechanism is closed, the manual pump or the automatic pump in the trailer valve is actuated, the pressure oil is output from the M port, one way is to enter the brake clutch after passing through the stop valve to realize brake contact, and the other way is to enter the pilot end of the hydraulic control reversing valve to drive the hydraulic control reversing valve to be opened to realize conduction between the two groups of closed high-pressure circuits; When the pressure obtained by the sensor exceeds the set value, a prompt signal is sent, the manual pump or the automatic pump in the trailer valve is stopped, and the trailer is allowed to be pulled; In the manual mode, when the pressure obtained by the sensor is lower than the set value, an alarm signal is sent to prompt the operator to start the manual pump in the trailer valve to compensate for the pressure drop caused by leakage; In the automatic mode, the pressure obtained by the sensor is sent to the controller, when the pressure is lower than the set value, the controller outputs a signal to the automatic pump in the trailer valve to gradually increase the rotating speed to compensate for the pressure drop caused by leakage until the pressure obtained by the sensor is not lower than the set value, and the automatic pump returns to the initial rotating speed.

Images