WO2019128013A1

WO2019128013A1 - Reverse brake control valve for hydraulic walking system

Info

Publication number: WO2019128013A1
Application number: PCT/CN2018/084988
Authority: WO
Inventors: 熊文辉; 张峥明; 任剡; 汪宏
Original assignee: 中国铁建高新装备股份有限公司
Priority date: 2017-12-28
Filing date: 2018-04-28
Publication date: 2019-07-04
Also published as: CN109973452A; CN109973452B

Abstract

A reverse brake control valve for a hydraulic walking system, comprising a valve body (15), a two-position three-way solenoid valve A (1) and a two-position three-way solenoid valve B (3) being provided in the valve body (15), and both the two-position three-way solenoid valve A (1) and the two-position three-way solenoid valve B (3) comprising orifices, an upstream side of the two-position three-way solenoid valve A (1) being connected to an oil inlet MB (20), and an upstream side of the two-position three-way solenoid valve B (3) being connected to an oil inlet MA (23); a downstream side of the two-position three-way solenoid valve A (1) is connected to a sequence valve A (14), and a downstream side of the sequence valve A (14) is connected to oil outlets XIV by means of a check valve C (11) and a check valve D (12), respectively. A solenoid directional valve, an overflow valve and the like mounted in the valve body provided by the reverse brake control valve adopt threaded insertion pieces, the structure is compact, and the reverse brake pressure control process is hydraulic automatic control, the reaction is rapid, sensitive and accurate, and can effectively limit the maximum reverse hydraulic braking force of the walking system, thereby controlling the magnitude of the anti-dragging force of the walking system to the engine, so as to ensure the normal function of the engine and hydraulic drive circuit elements and the operation safety of the whole vehicle.

Description

Reverse brake control valve for hydraulic running system

Technical field

The invention relates to a hydraulic control valve, in particular to a reverse brake control valve for a hydraulic running system, belonging to the technical field of hydraulic control.

Background technique

When the large-scale road maintenance machinery is self-propelled in the track line, the maximum running speed is usually 80-100km/h, and its running drive has three common transmission modes: hydraulic mechanical transmission, hydraulic transmission and electric transmission.

The hydraulic transmission travel system, also known as the hydraulic travel system, is usually driven by a closed hydraulic circuit consisting of a hydraulic variable pump and a variable motor. The output flow of the pump is controlled by an electronically controlled or hydraulically controlled travel handle to drive the hydraulic motor mounted on the axle. The hydraulic motor then drives the wheels to rotate to achieve the vehicle. The vehicle speed is adjusted by controlling the displacement of the variable pump, and the system working pressure varies with the operating conditions to meet the driving force requirements.

Since the large-scale road maintenance machinery is self-contained and has a large inertia, the hydraulically-traveled vehicle will be turned into a pump working condition when the running handle is quickly pulled back for deceleration or running on a long ramp. Turning into the motor working condition, the driving circuit generates the reverse hydraulic braking force through the hydraulic motor, and the hydraulic pump will reverse the engine. If no measures are taken, when the reverse drag pressure is too high, that is, the reverse hydraulic braking force is too large, It may cause the engine to fly, or damage the hydraulic components of the running drive circuit, affecting the normal running function of the whole vehicle, and even threatening the operation safety of the railway line.

The Chinese invention patent application with the application number 201510364468.3 relates to a control device for an actuator with a brake valve, comprising an oil inlet passage, an oil return passage, a three-position four-way reversing valve, and the three-position four-way reversing valve The valve is provided with a first port connected to the oil inlet passage, a second port connected to the oil return passage, and a third port and a fourth port connected to the actuator, and the oil inlet passage and the oil return passage are further provided. There is a brake valve for controlling the opening and closing of the oil inlet passage and the oil return passage, and the connection position of the brake valve and the oil inlet passage is located between the oil inlet end of the oil inlet passage and the first port, the brake valve and the oil return passage The connection position is between the oil return end of the oil return passage and the second port. The control device according to the above technical solution can be used for emergency braking in the operating state of the actuator without impact. However, it still cannot solve the braking problem of large road maintenance machinery.

Summary of the invention

The invention provides a reverse brake control valve for a hydraulic running system, and is particularly suitable for reverse braking control of a hydraulic running system of a large road maintenance machine.

The reverse brake control valve for the hydraulic running system of the present invention comprises a valve body, wherein the valve body is provided with a two-position three-way solenoid valve A and a two-position three-way solenoid valve B, the two-position three-way solenoid valve A and two positions The three-way solenoid valve B includes an orifice, the two-position three-way solenoid valve A is connected upstream of the oil inlet port MB, and the two-position three-way solenoid valve B is connected upstream to the oil inlet port MA; the two-position three-way electromagnetic The valve A is connected downstream of the sequence valve A, and the downstream of the sequence valve A is connected to an output port XIV through a check valve C and a check valve D. The two-position three-way solenoid valve B is connected downstream with a sequence valve B, and the sequence valve B Downstream, one output port XIII is connected to each of the check valve A and the check valve B, and an output port XIII downstream of the check valve A and an output port XIV downstream of the check valve C are further equipped with two The two-way solenoid valve B is further provided with a two-position two-way solenoid valve A between the output port XIII downstream of the check valve B and the output port XIV downstream of the check valve D, the sequence valve A A shuttle valve is also connected between the downstream and the downstream of the sequence valve B, and the shuttle valve is connected to the relief valve.

Preferably, the pressure of the relief valve ranges from 40 to 50 bar, and the outlet of the shuttle valve installed between the sequence valve A and the oil passage after the sequence valve B in the two branches is connected to the relief valve. Regardless of which branch is pressurized oil, the pressurized oil reaches the inlet of the overflow valve through the shuttle valve, and begins to overflow when the pressure of the pressure oil reaches the set pressure of the relief valve, thereby The maximum pressure of the pressurized oil after the sequence valve A and the sequence valve B are limited does not exceed the set pressure range of the relief valve by 40-50 bar.

In any of the above aspects, when the two-position two-way solenoid valve B and the two-position two-way solenoid valve A are de-energized, the output port XIII and the output port XIV are in communication, and the two ends of the variable cylinder of the hydraulic pump The pressure is the same, so the variable control cannot be performed, and the hydraulic pump has no flow output. When the whole vehicle is parked, the whole vehicle can be prevented from moving due to the pump malfunction.

In any of the above aspects, it is preferred that the oil inlets MA and MB are connected to the main ports A and B of the hydraulic traveling system drive circuit, respectively.

In any of the above aspects, it is preferred that the relief valve is also connected to the K pressure tap to detect its working pressure.

In any of the above aspects, it is preferred that the sequence valve A is connected to the K1 pressure tap to detect its working pressure.

In any of the above aspects, it is preferred that the sequence valve B is connected to the K2 pressure tap to detect its working pressure.

In any of the above aspects, it is preferable that the orifice of the two-position three-way solenoid valve A is a fixed orifice A.

In any of the above aspects, it is preferable that the orifice of the two-position three-way solenoid valve B is a fixed orifice B.

In any of the above aspects, it is preferred that the fixed orifice A has a diameter of 2-3 mm.

In any of the above aspects, it is preferred that the fixed orifice B has a diameter of 2-3 mm.

In any of the above aspects, it is preferred that the valve body includes a eye nut for transportation.

In any of the above aspects, it is preferable that the set pressure of the sequence valve is the maximum pressure of the hydraulic reverse brake, which can be adjusted according to the requirements of the entire vehicle.

In any of the above aspects, it is preferred that the set pressure of the sequence valve ranges from 90 to 120 bar.

In any of the above aspects, it is preferred that the relief valve employs a threaded insert.

Each hydraulic component and the oil passage in the valve body form a parallel branch, the composition of each branch is basically the same, starting from the inlet port MA or MB, through the two-position three-way solenoid valve, fixed orifice, sequence valve , check valve to output port XIII or XIV.

The two-position three-way solenoid valve A or the two-position three-way solenoid valve B passes the power loss or the power logic to control whether the input port and the sequence valve are connected or disconnected, when the two-position three-way solenoid valve A or two After the three-way solenoid valve B is de-energized, when the pressure of the inlet of the sequence valve A or the sequence valve B reaches its set opening pressure, the sequence valve A or the sequence valve B will be turned on, and the pressure oil passes through the sequence valve A or B and The latter check valve A or check valve B or check valve C or check valve D reaches the output port XIII or XIV, so that the variable mechanism of the hydraulic pump automatically adjusts the hydraulic pump, and the fixed orifice in the path A or fixed orifice B limits the flow through the sequence valve. The check valve ensures that the pressure oil can only flow out of the output port XIII or XIV, while ensuring that the two sets of output ports XIII or XIV are independent and do not affect each other, thereby enabling control of one pump or simultaneous control of both pumps. The closed hydraulic drive circuit realizes the required rotational speed and working pressure through the flow matching of the variable pump and the variable motor. Under normal circumstances, the hydraulic pump output flow drives the motor to rotate, and establishes a certain pressure between the hydraulic pump outlet and the motor inlet. The output flow of the hydraulic pump determines the speed of the motor. When the displacement of the hydraulic pump is rapidly reduced and the hydraulic motor maintains the original rotational speed, the flow rate of the hydraulic pump output will be less than the flow required by the hydraulic motor to maintain the rotational speed, and the flow output of the hydraulic motor is greater than the flow drawn by the hydraulic pump. When the hydraulic motor will become the pump working condition, the hydraulic pump will become the motor working condition, the hydraulic motor will drive the hydraulic pump to rotate; or when the displacement of the hydraulic pump is constant and the speed of the hydraulic motor is rapidly increased, the output of the hydraulic pump The flow rate is also less than the flow drawn by the hydraulic motor. The flow output from the hydraulic motor is greater than the flow drawn by the hydraulic pump. The hydraulic pump will become the motor operating condition and the hydraulic motor will become the pump operating condition.

In the self-propelled process, the above technical solution can be connected to the high-voltage side and the low-pressure side of the main circuit of the traveling system through the oil inlets MA and MB, and then the oil on the low-pressure side can be controlled by controlling the power loss of the two-position three-way electromagnetic reversing valve. The liquid reaches the sequence valve through the two-position three-way solenoid valve and the fixed orifice, and the oil on the high pressure side and the sequence valve are not connected. When the speed is reduced by the running handle or when running on the long ramp, the pump and motor of the running circuit The working conditions change, the pressure on the high pressure side and the low pressure side of the system also changes. The pressure on the original low pressure side rises, and the running drive circuit generates reverse hydraulic braking force. The speed of the whole vehicle will gradually decrease or the speed will no longer increase. When the pressure on the low pressure side rises to the set pressure of the sequence valve, the sequence valve is turned on, and the displacement of the pressure oil into the variable control cylinder of the hydraulic pump automatically increases the displacement of the pump, thereby absorbing the output flow of the hydraulic motor and making the original low pressure. The pressure on the side is no longer raised. When the vehicle speed drops to a certain value, the pressure on the low pressure side will decrease below the opening pressure of the sequence valve, the sequence valve will be closed, and the displacement of the hydraulic pump will be restored. The state of the original travel handle control.

The above solution includes two sets of output port XIII and two sets of output port XIV, which can control two parallel running pumps at the same time, or only use one set of output ports XIII or XIV to control a running pump, specifically Choose according to the number of running pumps.

The reverse running brake control valve of the hydraulic running system of the invention can detect the change of the pressure in the driving circuit of the running system, automatically control the displacement of the running pump, and limit the maximum reverse hydraulic braking force of the driving system, thereby effectively controlling the running system pair. The reverse thrust of the engine ensures the normal function of the engine and hydraulic drive circuit components and the operational safety of the vehicle.

The electromagnetic reversing valve and the relief valve installed in the valve body of the invention adopt the threaded inserting parts, and the structure is compact, and the reverse brake pressure control process is hydraulic automatic control, and the reaction is quick, sensitive and accurate, and can effectively limit the maximum reverse of the running system. The hydraulic braking force is used to control the magnitude of the anti-pull force of the running system to ensure the normal function of the engine and the hydraulic drive circuit components and the operational safety of the vehicle.

Sequence valve A and sequence valve B set a pressure of 100 bar and a relief valve set pressure of 40 bar.

When the whole vehicle is in a static state, the two-position two-way solenoid valve is de-energized, the two sets of X and X are connected, the hydraulic pump is in the bypass state, and the variable control cannot be performed, thereby effectively avoiding the malfunction of the hydraulic pump control and improving the parking safety. Sex.

Working condition 1: Forward self-propelled, the reverse brake pressure does not exceed 100 bar.

When the walking handle is moved forward, the two-position two-way solenoid valve is energized, and the two sets of X and X are disconnected. It is assumed that the high-pressure side is connected to the port MA at this time, and the low-pressure side is connected to the port MB. At this time, the two-position three-way solenoid valve is de-energized, MB is connected to the sequence valve A, the two-position three-way solenoid valve is energized, and the MA is disconnected from the sequence valve B. When moving forward normally, the pressure on the low pressure side of the running circuit is about 28 bar, the sequence valve A is in the closed state, and the hydraulic pump operates under the control of the running handle. When the whole vehicle is decelerated due to inertia acceleration or normal running during the downhill section, the motor will become the pump working condition, the pressure of the oil port MB will rise, the faster the car accelerates or the faster the handle pulls back, the oil The faster the pressure of the port MB rises, the reverse hydraulic braking force is generated by the running system because the motor becomes a pump operating condition. When the pressure of the port MB reaches 100 bar, the sequence valve A is opened, the pressure oil passes through the sequence valve A and the check valve C and the check valve D, and then enters the variable control mechanism of the hydraulic pump through the X port, in the shuttle valve and Under the action of the relief valve, the oil pressure of the port X is limited to 40 bar, and the displacement of the hydraulic pump is increased under the action of the pressure oil, thereby absorbing the oil output from the motor, so that the oil pressure of the port MB is not maintained. When it rises again, the reverse hydraulic braking force reaches a limited maximum value, and the whole vehicle is decelerated by the action of the hydraulic brake. When the vehicle speed decreases to a certain value, the oil pressure of the original low pressure side of the running circuit, that is, the MB port, will drop below 100 bar, the sequence valve A (14) is closed, and the displacement of the pump is restored to the running handle control state.

Working condition 2: Self-propelled backwards, the reverse braking pressure does not exceed 100 bar.

When the push handle is moved forward, the two-position two-way solenoid valves (9) and (10) are energized, and the two sets of XIII and XIV ports are disconnected, assuming that the port connected to the port MA is the low pressure side, and the oil The port MB is connected to the high pressure side. At this time, the two-position three-way solenoid valve (1) is energized, MB is disconnected from the sequence valve A (14), the two-position three-way solenoid valve (3) is de-energized, MA and the sequence valve B (5) is turned on. When moving backwards normally, the pressure on the low pressure side of the running circuit is about 28 bar, the sequence valve B (5) is in the closed state, and the hydraulic pump operates under the control of the running handle. When the whole vehicle is decelerated due to inertia acceleration or normal running during the downhill section, the motor will become the pump working condition, the pressure of the oil port MA will rise, the faster the car accelerates or the faster the handle pulls back, the oil The faster the pressure of the port MA rises, the reverse hydraulic braking force is generated by the running system because the motor becomes a pump operating condition. When the pressure of the port MA reaches 100 bar, the sequence valve B (5) is opened, and the pressure oil passes through the sequence valve B (5) and the check valve A (7) and the check valve B (8), and then through the two XIII oils. The port enters the variable control mechanism of the hydraulic pump. Under the action of the shuttle valve (6) and the relief valve (13), the oil pressure of the port XIII is limited to 40 bar, and the displacement of the hydraulic pump is increased under the action of the pressure oil. Therefore, the oil outputted by the motor is absorbed, so that the oil pressure of the oil port MA is kept rising, and the reverse hydraulic braking force reaches a limited maximum value, and the whole vehicle is decelerated by the action of the hydraulic brake. When the vehicle speed is reduced to a certain value, the original low pressure side pressure of the running circuit, that is, the oil pressure of the MA port will drop below 100 bar, the sequence valve B (5) is closed, and the displacement of the pump is restored to the running handle control state.

DRAWINGS

1 is a hydraulic schematic diagram of a preferred embodiment of a reverse brake control valve for a hydraulic running system according to the present invention;

Figure 2 is a front elevational view showing the structure of the embodiment shown in Figure 1;

Figure 3 is a left side view of the embodiment of Figure 2;

Figure 4 is a bottom plan view of the embodiment of Figure 2;

The meanings of the numbers in Figures 1 - 4 are:

1 two-position three-way solenoid valve A 2 fixed orifice A 3 two-position three-way solenoid valve B

4 fixed orifice B 5 sequence valve B 6 shuttle valve 7 check valve A 8 check valve B

9 two-position two-way electromagnetic reversing valve B 10 two-position two-way electromagnetic reversing valve A 11 one-way valve C

12 check valve D 13 relief valve 14 sequence valve A 15 valve body 17K2 pressure tap

18K3 pressure measuring port 19 ring nut 16K1 pressure measuring port 20MB port

21 output port XIIIA 22 output port XIVA23 inlet port MA 24 output port XIVB

25 output port XIIIB.

Detailed ways

Embodiment 1.1: A reverse brake control valve for a hydraulic running system includes a valve body 15 in which a two-position three-way solenoid valve A 1 and a two-position three-way solenoid valve B 3 are disposed, and two-position three-way electromagnetic The valve A 1 is connected upstream of the oil inlet port MB 20 , the two-position three-way solenoid valve B3 is connected upstream of the oil inlet port MA 23 , the two-position three-way solenoid valve A 1 includes a fixed orifice A 2 , and the fixed orifice A 2 has a diameter of 2mm; the two-position three-way solenoid valve B 3 includes a fixed orifice B 4 , the fixed orifice B 4 has a diameter of 2 mm; the two-position three-way solenoid valve A 1 is connected downstream with a sequence valve A 14 , and the sequence valve A 14 passes downstream The check valve C 11 is connected to the output port XIVA 22, and the downstream of the sequence valve A 14 is also connected to the output port XIVB 24 through the check valve D 12 , and the 2/2-way solenoid valve B 3 is connected downstream to the sequence valve B 5 , The sequence valve B5 is connected downstream to the output port XIIIA 21 via a check valve A7, and the sequence valve B5 is also connected to the output port XIV A 22 via a check valve B8, the output oil downstream of the check valve A7 The port XIIIA21 and the output port X IV A 22 downstream of the check valve C 11 are also equipped with a two-position two-way solenoid valve B and a check valve B 8 downstream. There is also a two-position two-way solenoid valve A 10 between the output port XIV A 22 and the output port XIV B 24 downstream of the check valve D 12 , and the downstream of the sequence valve A 14 and the downstream of the sequence valve B 5 are also connected. The shuttle valve 6, the shuttle valve 6 is connected to the relief valve 13, the relief valve is a threaded insert, and the valve body 15 includes a ring nut 19 for convenient transportation.

The pressure of the relief valve 13 ranges from 40 to 50 bar, and the outlet of the shuttle valve 6 installed between the oil passages of the sequence valve A14 and the sequence valve B5 in the two branches is connected to the relief valve 13, no matter which one In the branch, it is pressure oil, and the pressure oil reaches the inlet of the relief valve 13 through the shuttle valve 6. When the pressure of the pressure oil reaches the set pressure of the relief valve 13, the overflow begins, thereby limiting the sequence valve A14 and the sequence valve B5. The maximum pressure of the pressurized oil does not exceed the set pressure range of the relief valve 13 by 40-50 bar; the relief valve 13 is also connected to the K3 pressure measuring port 18 to detect its working pressure; the sequence valve A14 is connected to the K1 pressure measuring port 16 so that The working pressure is detected; the sequence valve B5 is connected to the K2 pressure measuring port 17 to detect its working pressure.

When the two-position two-way solenoid valve B 9 and the two-position two-way solenoid valve A 10 are de-energized, the output port XIII and the output port XIV are connected, and the pressure of the variable cylinder of the hydraulic pump is the same, so variable control cannot be performed, the hydraulic pump No flow output, when the whole vehicle stops, it can prevent the whole vehicle from moving due to pump malfunction.

The inlet port MA 23 and the inlet port MB 20 are connected to the main ports A and B of the hydraulic traveling system drive circuit, respectively.

The set pressure of the sequence valve A14 and the sequence valve B5 is the maximum pressure of the hydraulic reverse brake, which can be adjusted according to the requirements of the whole vehicle. The set pressure of the sequence valve A14 and the sequence valve B5 ranges from 90 to 120 bar. Each hydraulic component and the oil passage in the valve body form two parallel branches, and the composition of each branch is basically the same, starting from the oil inlet port MA 23 or the oil inlet port MB 20, and being fixed by a two-position three-way solenoid valve. Throttle, sequence valve, check valve to output port XIII or XIV.

The two-position three-way solenoid valve A 1 or the two-position three-way solenoid valve B3 passes the power failure or the power logic to control whether the input port and the sequence valve are connected or disconnected, when the two-position three-way solenoid valve A 1 or After the two-position three-way solenoid valve B3 is de-energized, when the pressure of the inlet of the sequence valve A 14 or the sequence valve B 5 reaches its set opening pressure, the sequence valve A 14 or the sequence valve B 5 will be turned on, and the pressure oil passes through the sequence. Valve A 14 or sequence valve B5 and its check valve A or check valve B or check valve C or check valve D reach the output port XIIIA 21 or the output port XIIIB 25 or the output port XIVA 22 or the output The port XIVB 24, whereby the variable mechanism entering the hydraulic pump automatically adjusts the hydraulic pump, and the fixed orifice A or fixed orifice B in the path limits the flow through the sequence valve A14 and the sequence valve B5. The check valve ensures that the pressure oil can only flow out from the output port XIIIA21 or the output port XIIIB 25 or the output port XIVA 22 or the output port XIVB 24, while ensuring two sets of output port XIIIA 21, output port XIIIB 25 or output The oil port XIVA 22 and the output port XIVB 24 are independent and do not affect each other, so that one pump can be controlled or two pumps can be controlled at the same time.

The closed hydraulic drive circuit realizes the required rotational speed and working pressure through the flow matching of the variable pump and the variable motor. Under normal circumstances, the hydraulic pump output flow drives the motor to rotate, and establishes a certain pressure between the hydraulic pump outlet and the motor inlet. The output flow of the hydraulic pump determines the speed of the motor. When the displacement of the hydraulic pump is rapidly reduced and the hydraulic motor maintains the original rotational speed, the flow rate of the hydraulic pump output will be less than the flow required by the hydraulic motor to maintain the rotational speed, and the flow output of the hydraulic motor is greater than the flow drawn by the hydraulic pump. When the hydraulic motor will become the pump working condition, the hydraulic pump will become the motor working condition, the hydraulic motor will drive the hydraulic pump to rotate; or when the displacement of the hydraulic pump is constant and the speed of the hydraulic motor is rapidly increased, the output of the hydraulic pump The flow rate is also less than the flow drawn by the hydraulic motor. The flow output from the hydraulic motor is greater than the flow drawn by the hydraulic pump. The hydraulic pump will become the motor operating condition and the hydraulic motor will become the pump operating condition.

The above embodiment includes two sets of output port XIII and two sets of output port XIV, that is, the output port XIIIA 21 and the output port XIIIB 25, the output port XIVA 22 and the output port XIVB 24, through the output port XIIIA 21 and output port XIIIB 25, output port XIVA 22 and output port XIVB 24 can simultaneously control two parallel running pumps.

Embodiment 1.2: A reverse brake control valve for a hydraulic running system is the same as Embodiment 1.1 except that only one set of output port XIIIA 21 and output port XIIIB 25 are used to control a running pump.

Embodiment 1.3: A reverse travel brake control valve for a hydraulic running system is the same as Embodiment 1.1 except that only one set of output port XIVA 22 and output port XIVB 24 are used to control a running pump.

Embodiment 1.4: A reverse brake control valve for a hydraulic running system is the same as Embodiment 1.1 except that the fixed orifice A 2 has a diameter of 2.5 mm.

Embodiment 1.5: A reverse brake control valve for a hydraulic running system, which is the same as Embodiment 1.1 or 1.4, except that the fixed orifice B 4 has a diameter of 2.5 mm.

Embodiment 1.6: A reverse brake control valve for a hydraulic running system is the same as Embodiment 1.1 except that the fixed orifice A 2 has a diameter of 3 mm.

Embodiment 1.7: A reverse brake control valve for a hydraulic running system is the same as Embodiment 1.1 or 1.6 except that the fixed orifice B 4 has a diameter of 3 mm.

The reverse running brake control valve of the hydraulic running system of the above embodiment can detect the change of the pressure in the driving circuit of the running system, automatically control the displacement of the running pump, and limit the maximum reverse hydraulic braking force of the driving system, thereby effectively controlling the running system. The reverse drag of the engine ensures the normal function of the engine and hydraulic drive circuit components and the operational safety of the vehicle.

Embodiment 2.1: A reverse braking control method for a hydraulic running system, comprising:

A1. During the self-propelled operation of the working vehicle, the inlet port MA23 and the inlet port MB20 are connected to the high-pressure side and the low-pressure side of the main circuit of the running system, and then the low-voltage condition of the two-position three-way electromagnetic reversing valve is controlled to make the low voltage The oil on the side reaches the sequence valve through the two-position three-way solenoid valve and the fixed orifice;

B1. The oil on the high pressure side is not connected to the sequence valve. When the speed is reduced by the running handle or when running on the long ramp, the pump and motor operating conditions of the running circuit change, and the pressure on the high pressure side and the low pressure side of the system also changes. The pressure on the original low pressure side rises, and the running drive circuit generates the reverse hydraulic braking force. The speed of the whole vehicle will gradually decrease or the speed will not increase any more. When the pressure on the original low pressure side rises to the set pressure of the sequence valve, the sequence When the valve is turned on, the pressure oil enters the variable pressure cylinder of the hydraulic pump, and the displacement of the automatic control pump is rapidly increased, thereby absorbing the output flow of the hydraulic motor, so that the pressure on the original low pressure side is no longer raised;

C1. When the vehicle speed drops to a certain value, the pressure on the low pressure side will decrease below the opening pressure of the sequence valve, the sequence valve will be closed, and the displacement of the hydraulic pump will return to the state of the original running handle control.

Steps a1, b1, and c1 are sequentially executed to reach the reverse braking control of the hydraulic running system.

Embodiment 2.2: A reverse braking control method for a hydraulic running system, comprising:

A2. Sequence valve A14 and sequence valve B5 set pressure is 100bar, relief valve 13 set pressure is 40bar; forward self-propelled, reverse brake pressure does not exceed 100bar;

B2. When the push handle is moved forward, the two-position two-

way solenoid valves

9 and 10 are energized, the output port XIIIA 21 is disconnected from the output port XIVA 22, the output port XIIIB 25 and the output port XIVB 24 are off. On; assume that the high pressure side connected to the inlet port MA 23 and the low pressure side connected to the inlet port MB 20, at this time, the two-position three-way solenoid valve 1 is de-energized, the inlet port MB 20 and the sequence valve When A14 is turned on, the two-position three-way solenoid valve 3 is energized, the oil inlet port MA23 is disconnected from the sequence valve B5; when the forward running normally, the low pressure side pressure of the running circuit is about 28 bar, the sequence valve A14 is in the closed state, and the hydraulic pump is in Work under the control of the travel handle;

C2. When the whole vehicle is decelerated due to inertia acceleration or normal running during the downhill section, the motor will become the pump working condition, the pressure of the inlet port MB 20 will rise, and the faster the car accelerates or the handle pulls back. The faster the pressure of the inlet port MB 20 rises, the reverse hydraulic braking force is generated by the running system because the motor becomes the pump operating condition;

D2. When the pressure of the inlet port MB 20 reaches 100 bar, the sequence valve A14 is opened, and the pressure oil passes through the sequence valve A14 and the check valve C11 and the check valve D12, and then enters through the output port XIVA 22 and the output port XIVB 24. The variable control mechanism of the hydraulic pump, under the action of the shuttle valve 6 and the relief valve 13, the oil pressure of the oil port XIV is limited to 40 bar, and the displacement of the hydraulic pump under the action of the pressure oil becomes large, thereby absorbing the output of the motor. The oil keeps the oil pressure of the inlet port MB 20 from rising, and the reverse hydraulic braking force reaches a limited maximum value, and the whole vehicle is decelerated by the action of the hydraulic brake;

E2. When the vehicle speed decreases to a certain value, the oil pressure of the original low pressure side of the running circuit, that is, the oil inlet port MB 20 will drop below 100 bar, the sequence valve A14 is closed, and the displacement of the pump is restored to the running handle control state;

F2. When the whole vehicle is at rest, the two-position two-way solenoid valve A9 and the two-position two-way solenoid valve B10 are de-energized, and the two output ports XIII and XIV are connected, that is, the output port XIIIA 21 and the output port are connected. The XIVA22 is connected, the output port XIIIB 25 is in communication with the output port XIVB 24; the hydraulic pump is in the bypass state, and the variable control cannot be performed, thereby effectively avoiding the malfunction of the hydraulic pump control and improving the parking safety.

Steps a2, b2, c2, d2, e2, and f2 are sequentially performed.

Embodiment 2.3: A reverse braking control method for a hydraulic running system, comprising:

A3. Sequence valve A14 and sequence valve B5 set pressure is 100bar, relief valve 13 set pressure is 40bar; backward self-propelled, reverse brake pressure does not exceed 100bar;

B3. When the push handle is moved forward, the two-position two-

way solenoid valves

9 and 10 are energized, the output port XIIIA21 is disconnected from the output port XIVA 22, and the output port XIIIB 25 is disconnected from the output port XIVB 24; It is assumed that the low pressure side connected to the oil inlet port MA 23 and the high pressure side connected to the oil inlet port MB 20 at this time, the two-position three-way solenoid valve 1 is energized, and the oil inlet port MB 20 and the sequence valve A14 are disconnected. Open, the two-position three-way solenoid valve 3 is de-energized, and the inlet port MA 23 is connected to the sequence valve B5;

C3. When moving backwards normally, the pressure on the low pressure side of the running circuit is about 28 bar, the sequence valve B5 is in the closed state, and the hydraulic pump works under the control of the running handle; when the whole vehicle is pulled back in the downhill section due to inertia acceleration or normal running When the handle is decelerating, the motor will become the pump working condition, the pressure of the inlet port MA 23 will rise, the faster the car accelerates or the faster the handle pulls back, the faster the pressure of the inlet port MA 23 rises, because the motor becomes In the case of pump operation, the running system will generate reverse hydraulic braking force;

D3. When the pressure of the inlet port MA 23 reaches 100 bar, the sequence valve B5 is opened, and the pressure oil passes through the sequence valve B5 and the check valve A7 and the check valve B8, and then enters through the output port XIIIA 21 and the output port XIIIB 25 Variable control mechanism for the hydraulic pump;

E3. Under the action of the shuttle valve 6 and the relief valve 13, the oil pressure of the output port XIIIA 21 and the output port XIIIB 25 is limited to 40 bar, and the displacement of the hydraulic pump is increased under the action of the pressure oil, thereby absorbing The oil outputted by the motor keeps the oil pressure of the inlet port MA 23 from rising, and the reverse hydraulic braking force reaches a limited maximum value, and the whole vehicle is decelerated by the action of the hydraulic brake;

F3. When the vehicle speed is reduced to a certain value, the original low pressure side pressure of the running circuit, that is, the oil pressure of the inlet port MA 23 will drop below 100 bar, the sequence valve B5 is closed, and the displacement of the pump is restored to the running handle control state. Steps a3, b3, c3, d3, e3, and f3 are sequentially performed.

Claims

A reverse running brake control valve for a hydraulic running system, comprising a valve body 15, wherein a two-position three-way solenoid valve A (1) and a two-position three-way solenoid valve B (3) are disposed in the valve body 15, the two positions The three-way solenoid valve A (1) and the two-position three-way solenoid valve B (3) each include an orifice, and the two-position three-way solenoid valve A (1) is connected upstream of the inlet port MB (20), the second The three-way solenoid valve B (3) is connected upstream of the oil inlet port MA (23); characterized in that: the two-position three-way solenoid valve A (1) is connected downstream of the sequence valve A (14), the sequence valve A (14) The downstream is connected to an output port XIV through the check valve C (11) and the check valve D (12), and the second three-way solenoid valve B (3) is connected downstream of the sequence valve B (5), the sequence valve B ( 5) Downstream is connected to one output port XIII through the check valve A (7) and the check valve B (8), the output port XIII downstream of the check valve A (7) and the downstream of the check valve C (11) There is also a two-position two-way solenoid valve B (9) between the output ports XIV, and between the output port XIII downstream of the check valve B (8) and the output port XIV downstream of the check valve D (12). It is equipped with a two-position two-way solenoid valve A (10). A shuttle valve (6) is also connected between the downstream of the sequence valve A (14) and the downstream of the sequence valve B (5). The shuttle valve (6) is connected to the overflow. (13).
A reverse brake control valve for a hydraulic running system according to claim 1, wherein said relief valve has a pressure range of 40 to 50 bar, and a sequence valve A (14) and a sequence valve B in the two branches. (5) The oil outlet of the shuttle valve (6) installed between the rear oil passages is connected to the relief valve, and no matter which branch is the pressure oil, the pressure oil will reach the overflow through the shuttle valve. The inlet of the valve starts to overflow when the pressure of the pressure oil reaches the set pressure of the relief valve, thereby limiting the maximum pressure of the pressure oil after the sequence valve A (14) and the sequence valve B (5) does not exceed the overflow The set pressure of the flow valve ranges from 40 to 50 bar.
A reverse brake control valve for a hydraulic running system according to claim 1, wherein the oil inlet port MA (23) and the oil inlet port MB (20) are respectively associated with the main port A of the hydraulic traveling system drive circuit. Connected to B.
A reverse brake control valve for a hydraulic running system according to claim 1, wherein the relief valve (13) is further connected to the K3 pressure measuring port (18), and the sequence valve A (14) is connected to the K1 pressure measuring port ( 16), the sequence valve B (5) is connected to the K2 pressure measuring port (17).
The reverse brake control valve for a hydraulic running system according to claim 1, wherein the two-way three-way solenoid valve A (1) comprises an orifice that is a fixed orifice A (2), and the throttle is fixed. Hole A (2) has a diameter of 2-3 mm.
The reverse brake control valve for a hydraulic running system according to claim 1, wherein the two-way three-way solenoid valve B (3) comprises an orifice that is a fixed orifice B (4), and the fixed throttle Hole B (4) has a diameter of 2-3 mm.
A reverse brake control valve for a hydraulic running system according to claim 1, wherein the set pressure of the sequence valve A (14) and the sequence valve B (5) is the maximum pressure of the hydraulic reverse brake. The set pressure of the sequence valve A (14) and the sequence valve B (5) ranges from 90 to 120 bar.
A reverse braking control method for a hydraulic running system, characterized in that:

A1. During the self-propelled operation of the working vehicle, the inlet port MA 23 and the inlet port MB 20 are connected to the high-pressure side and the low-pressure side of the main circuit of the running system, and then the power loss of the two-position three-way electromagnetic reversing valve is controlled. Passing the oil on the low pressure side through the 2/2-way solenoid valve and the fixed orifice to the sequence valve;

B1. The oil on the high pressure side is not connected to the sequence valve. When the speed is reduced by the running handle or when running on the long ramp, the pump and motor operating conditions of the running circuit change, and the pressure on the high pressure side and the low pressure side of the system also changes. The pressure on the original low pressure side rises, and the running drive circuit generates the reverse hydraulic braking force. The speed of the whole vehicle will gradually decrease or the speed will not increase any more. When the pressure on the original low pressure side rises to the set pressure of the sequence valve, the sequence When the valve is turned on, the pressure oil enters the variable pressure cylinder of the hydraulic pump, and the displacement of the automatic control pump is rapidly increased, thereby absorbing the output flow of the hydraulic motor, so that the pressure on the original low pressure side is no longer raised;

C1. When the vehicle speed drops to a certain value, when the low pressure side pressure will decrease below the opening pressure of the sequence valve, the sequence valve is closed, and the displacement of the hydraulic pump is restored to the state of the original running handle control;

Steps a1, b1, and c1 are sequentially executed to reach the reverse braking control of the hydraulic running system.
A reverse braking control method for a hydraulic running system, comprising the steps of:

A2. Sequence valve A14 and sequence valve B5 set pressure is 100bar, relief valve 13 set pressure is 40bar; forward self-propelled, reverse brake pressure does not exceed 100bar;

B2. When the push handle is moved forward, the two-position two-way solenoid valves 9 and 10 are energized, the output port XIIIA 21 is disconnected from the output port XIVA 22, the output port XIIIB 25 and the output port XIVB 24 are off. On; assume that the high pressure side connected to the inlet port MA 23 and the low pressure side connected to the inlet port MB 20, at this time, the two-position three-way solenoid valve 1 is de-energized, the inlet port MB 20 and the sequence valve When A14 is turned on, the two-position three-way solenoid valve 3 is energized, the oil inlet port MA23 is disconnected from the sequence valve B5; when the forward running normally, the low pressure side pressure of the running circuit is about 28 bar, the sequence valve A14 is in the closed state, and the hydraulic pump is in Work under the control of the travel handle;

C2. When the whole vehicle is decelerated due to inertia acceleration or normal running during the downhill section, the motor will become the pump working condition, the pressure of the inlet port MB 20 will rise, and the faster the car accelerates or the handle pulls back. The faster the pressure of the inlet port MB 20 rises, the reverse hydraulic braking force is generated by the running system because the motor becomes the pump operating condition;

D2. When the pressure of the inlet port MB 20 reaches 100 bar, the sequence valve A14 is opened, and the pressure oil passes through the sequence valve A14 and the check valve C11 and the check valve D12, and then enters through the output port XIVA 22 and the output port XIVB 24. The variable control mechanism of the hydraulic pump, under the action of the shuttle valve 6 and the relief valve 13, the oil pressure of the oil port XIV is limited to 40 bar, and the displacement of the hydraulic pump under the action of the pressure oil becomes large, thereby absorbing the output of the motor. The oil keeps the oil pressure of the inlet port MB 20 from rising, and the reverse hydraulic braking force reaches a limited maximum value, and the whole vehicle is decelerated by the action of the hydraulic brake;

E2. When the vehicle speed decreases to a certain value, the oil pressure of the original low pressure side of the running circuit, that is, the inlet port MB 20 will drop below 100 bar, the sequence valve A14 is closed, and the displacement of the pump is restored to the running handle control state;

F2. When the whole vehicle is at rest, the two-position two-way solenoid valve A9 and the two-position two-way solenoid valve B10 are de-energized, and the two output ports XIII and XIV are connected, that is, the output port XIIIA 21 and the output port are connected. The XIVA 22 is connected, the output port XIIIB 25 is in communication with the output port XIVB 24; the hydraulic pump is in the bypass state, and the variable control cannot be performed, thereby effectively avoiding the malfunction of the hydraulic pump control and improving the parking safety;

It is characterized in that steps a2, b2, c2, d2, e2, and f2 are sequentially performed.
A reverse braking control method for a hydraulic running system, characterized in that:

A3. Sequence valve A14 and sequence valve B5 set pressure is 100bar, relief valve 13 set pressure is 40bar; backward self-propelled, reverse brake pressure does not exceed 100bar;

B3. When the push handle is moved forward, the 2/2-way solenoid valves 9 and 10 are energized, the output port XIIIA 21 is disconnected from the output port XIVA 22, and the output port XIIIB 25 is disconnected from the output port XIVB 24. Assume that the low pressure side connected to the inlet port MA 23 and the high pressure side connected to the inlet port MB 20 at this time, the two-position three-way solenoid valve 1 is energized, the inlet port MB 20 and the sequence valve A14 Disconnected, the two-position three-way solenoid valve 3 is de-energized, and the inlet port MA 23 is connected to the sequence valve B5;

C3. When moving backwards normally, the pressure on the low pressure side of the running circuit is about 28 bar, the sequence valve B5 is in the closed state, and the hydraulic pump works under the control of the running handle; when the whole vehicle is pulled back in the downhill section due to inertia acceleration or normal running When the handle is decelerating, the motor will become the pump working condition, the pressure of the inlet port MA 23 will rise, the faster the car accelerates or the faster the handle pulls back, the faster the pressure of the inlet port MA 23 rises, because the motor becomes In the case of pump operation, the running system will generate reverse hydraulic braking force;

D3. When the pressure of the inlet port MA 23 reaches 100 bar, the sequence valve B5 is opened, and the pressure oil passes through the sequence valve B5 and the check valve A7 and the check valve B8, and then enters through the output port XIIIA 21 and the output port XIIIB 25 Variable control mechanism for the hydraulic pump;

E3. Under the action of the shuttle valve 6 and the relief valve 13, the oil pressure of the output port XIIIA 21 and the output port XIIIB 25 is limited to 40 bar, and the displacement of the hydraulic pump is increased under the action of the pressure oil, thereby absorbing The oil outputted by the motor keeps the oil pressure of the inlet port MA 23 from rising, and the reverse hydraulic braking force reaches a limited maximum value, and the whole vehicle is decelerated by the action of the hydraulic brake;

F3. When the vehicle speed is reduced to a certain value, the original low pressure side pressure of the running circuit, that is, the oil pressure of the inlet port MA 23 will drop below 100 bar, the sequence valve B5 is closed, and the displacement of the pump is restored to the running handle control state;

Steps a3, b3, c3, d3, e3, and f3 are sequentially performed.