Hydraulic system of double-hung mine dump truck

Abstract

The application provides a hydraulic system of a double-hung mine dump truck, belonging to the technical field of mine dump trucks. The system comprises a tractor hydraulic unit, which comprises an overflow valve, a steering priority valve, a first one-way valve, a first ball valve, a second ball valve, a first pressure reducing valve, a first electromagnetic reversing valve and some ports. The system is connected with a steering gear, a constant pressure variable pump and a parking brake of the tractor, and can provide hydraulic oil to the parking brake and the steering gear based on the hydraulic oil provided by the constant pressure variable pump. Thus, the two functions of steering and braking can be realized by the hydraulic system, enriching the functions that can be realized by the hydraulic system. In addition, the constant pressure variable pump is used for pressure supply in the steering and braking system, which can reduce the energy consumption of the whole vehicle and prolong the service life of the hydraulic elements.

Description

Technical Field

[0001] This application relates to the field of mining dump truck technology, and more specifically, to a hydraulic system for a double-trailer mining dump truck. Background Technology

[0002] The hydraulic system of a double-trailer mining dump truck is a hydraulic system used to provide various functions to the double-trailer mining dump truck.

[0003] A current hydraulic system for a dual-trailer mining dump truck includes a hydraulic power steering unit, which provides steering functionality to the tractor unit within the truck. Additionally, the truck includes an air brake unit, which provides braking functionality.

[0004] However, the aforementioned hydraulic system has a relatively limited function.

[0005] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this application is to overcome the shortcomings of the prior art and provide a hydraulic system for a double-trailer mining dump truck.

[0007] According to one aspect of this application, a hydraulic system for a double-trailer mining dump truck is provided, the double-trailer mining dump truck including a tractor, a first trailer and a second trailer; The hydraulic system of the double-trailer mining dump truck includes: a tractor hydraulic unit, which includes a steering priority valve, an overflow valve, a first check valve, a first ball valve, a second ball valve, a first pressure reducing valve, a first solenoid directional valve, a first port, a second port, a third port, and a fourth port. The steering priority valve is connected to the second port, the outlet of the first check valve, and the third port respectively. The second port is connected to the oil inlet of the steering gear of the tractor vehicle, the third port is connected to the control port of the steering gear, and the oil return port of the steering gear is connected to the fourth port. The overflow valve is connected to the outlet of the first check valve and the fourth port, respectively. The first ball valve is connected to the outlet of the first check valve and the fourth port respectively. The inlet of the first check valve is connected to the first port. The first port is connected to the constant pressure variable pump in the double-trailer mining dump truck. The second ball valve is connected to the fourth port and the oil inlet of the first pressure reducing valve, respectively; The return port of the first pressure reducing valve is connected to the return port of the first solenoid directional valve, the working port is connected to the inlet port of the first solenoid directional valve, and the working port of the first solenoid directional valve is connected to the parking brake of the tractor.

[0008] Optionally, the system further includes a first proportional pressure reducing valve, a second proportional pressure reducing valve, a fifth port, and a sixth port; The first proportional pressure reducing valve is connected to the return port of the first electromagnetic reversing valve, the inlet port of the first pressure reducing valve, and the fifth port, respectively. The fifth port is connected to the service brake of the tractor. The second proportional pressure reducing valve is connected to the return port of the first electromagnetic reversing valve, the inlet port of the first pressure reducing valve, and the sixth port, respectively. The sixth port is connected to the service brake of the first trailer.

[0009] Optionally, the system further includes a seventh port, which is connected to the steering accumulator of the tractor and the outlet of the first one-way valve, respectively.

[0010] Optionally, the system further includes an eighth port, which is connected to the brake accumulator of the tractor, and the oil inlet of the first pressure reducing valve is connected to the eighth port.

[0011] Optionally, the system further includes a ninth port, which is connected to the fourth port; The ninth port is also connected to a radiator in the tractor, which has an oil temperature controller for activating the radiator when the oil temperature in the radiator is greater than or equal to a first specified temperature.

[0012] Optionally, the system further includes: a first manual pump and a tenth port, the tenth port being connected to one end of the first manual pump and the hydraulic pump station tank of the tractor, and the other end of the first manual pump being connected to the oil inlet of the first pressure reducing valve.

[0013] Optionally, the system further includes: two trailer hydraulic pump station lifting valve groups corresponding to the first trailer and the second trailer, respectively; Each of the trailer hydraulic pump station lifting valve assemblies includes a second solenoid directional valve, a first two-position three-way directional valve, a second two-position three-way directional valve, a first diverter valve, a second diverter valve, an eleventh port, a twelfth port, a thirteenth port, a fourteenth port, a fifteenth port, and a sixteenth port. The return port of the second electromagnetic directional valve is connected to the sixteenth port, the sixteenth port is connected to the hydraulic oil tank of the trailer, the working port of the second electromagnetic directional valve is connected to the control port of the first two-position three-way directional valve and the second two-position three-way directional valve, the inlet port of the second electromagnetic directional valve is connected to the eleventh port, the eleventh port is connected to the gear pump of the trailer, and the gear pump is connected to the hydraulic oil tank of the trailer. The first valve port of the first two-position three-way reversing valve is connected to the thirteenth port, and the thirteenth port is connected to the lifting valve of the trailer. The second valve port of the first two-position three-way reversing valve is connected to the fourteenth port, and the fourteenth port is connected to the cargo box lifting cylinder of the trailer. The third valve port of the first two-position three-way reversing valve is connected to the fifteenth port, and the fifteenth port is connected to the side door lifting cylinder of the trailer. The control return port of the first two-position three-way reversing valve is connected to the sixteenth port. The first valve port of the second 2-position three-way directional valve is connected to the 12th port, and the 12th port is connected to the lifting valve of the trailer. The second valve port of the second 2-position three-way directional valve is connected to the second diverter valve, and the second diverter valve is connected to the cargo box lifting cylinder of the trailer. The third valve port of the second 2-position three-way directional valve is connected to the first diverter valve, and the first diverter valve is connected to the side door lifting cylinder of the trailer. The control return port of the second 2-position three-way directional valve is connected to the 16th port.

[0014] Optionally, the number of cargo box lifting cylinders is 2, and the two cargo box lifting cylinders are respectively connected to the second valve port of the second two-position three-way reversing valve; The number of side door lifting cylinders is 2, and the two side door lifting cylinders are respectively connected to the third valve port of the second two-position three-way reversing valve.

[0015] Optionally, the system further includes a second trailer hydraulic pump station brake valve assembly installed on the second trailer. The second trailer hydraulic pump station brake valve assembly includes a second manual pump, a second pressure reducing valve, a third solenoid directional valve, a third ball valve, a third proportional pressure reducing valve, a second check valve, a seventeenth port, an eighteenth port, a nineteenth port, a twentieth port, a twenty-first port, a twenty-second port, and a twenty-third port. The second manual pump is connected to the seventeenth port and the working oil port of the second pressure reducing valve, the seventeenth port is connected to the hydraulic oil tank of the second trailer, and the nineteenth port is connected to the parking brake of the second trailer. The oil inlet of the second pressure reducing valve is connected to the oil outlet of the second check valve, the oil return port of the second pressure reducing valve is connected to the twenty-third port, the twenty-third port is connected to the twenty-fifth port of the tractor hydraulic unit, and the twenty-fifth port is connected to the oil return port of the first solenoid directional valve. The oil inlet of the third solenoid directional valve is connected to the working oil port of the second pressure reducing valve, the working oil port of the third solenoid directional valve is connected to the nineteenth port, and the oil return port of the third solenoid directional valve is connected to the twenty-third port. One end of the third ball valve is connected to the twenty-third port, and the other end of the third ball valve is connected to the oil inlet of the second pressure reducing valve; The third proportional pressure reducing valve is connected to the other end of the third ball valve, the second thirteenth port and the second eleventh port respectively. The second eleventh port is connected to the service brake of the second trailer, and the second twelfth port is connected to the second eleventh port and the pressure sensor respectively. The inlet of the second one-way valve is connected to the eighteenth port, and the outlet is connected to the other end of the third ball valve and the twentieth port. The twentieth port is connected to the brake accumulator of the second trailer.

[0016] Optionally, the tractor hydraulic unit further includes a third check valve and a twenty-fourth port. The inlet of the third check valve is connected to the first port, and the outlet of the third check valve is connected to the twenty-fourth port. The twenty-fourth port is also connected to one end of the first manual pump and the eighteenth port of the second trailer hydraulic pump station brake valve group.

[0017] The beneficial effects of the hydraulic system of the double-trailer mining dump truck provided in this application include at least the following: A hydraulic system for a dual-trailer mining dump truck is provided. The system includes a tractor hydraulic unit, which comprises an overflow valve, a flow divider / combiner valve, a first check valve, a first ball valve, a second ball valve, a first pressure reducing valve, a first solenoid directional valve, and several ports. The system is connected to the tractor's steering gear, constant pressure variable pump, and parking brake. It can supply hydraulic oil to the parking brake and steering gear based on the hydraulic oil supplied by the constant pressure variable pump. Thus, both steering and braking functions can be achieved through the hydraulic system, enriching the functions that the hydraulic system can perform.

[0018] In addition, the steering and braking system uses a constant pressure variable pump for pressure supply, which can reduce the energy consumption of the whole vehicle and extend the service life of hydraulic components.

[0019] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0021] Figure 1 This is a schematic diagram of the hydraulic system of a double-trailer mining dump truck provided in an embodiment of this application.

[0022] Figure 2 This is a schematic diagram of the hydraulic system of another double-trailer mining dump truck provided in this application embodiment.

[0023] Figure 3 This is a schematic diagram of the hydraulic system of another double-trailer mining dump truck provided in this application embodiment.

[0024] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0026] In current double-trailer mining dump trucks, the tractor unit includes a hydraulic power steering unit and an air brake unit. The hydraulic power steering unit provides steering function to the tractor unit in the double-trailer mining dump truck, while the air brake unit provides braking function.

[0027] However, the aforementioned hydraulic systems have relatively limited functionality, and the air brake units have slow response times, seriously affecting driving safety. Furthermore, the hydraulic power steering units in these technologies have numerous components and limited chassis mounting space, resulting in cumbersome installation and complex hydraulic piping connections.

[0028] The hydraulic system of the double-trailer mining dump truck provided in this application embodiment can solve some of the problems existing in the above-mentioned related technologies.

[0029] The double-trailer mining dump truck described in this application includes a tractor, a first trailer, and a second trailer. The first trailer is connected to the tractor, and the second trailer is connected to the first trailer. The tractor is used to tow the first and second trailers, and thus the tractor has braking and steering components. The first and second trailers can be side-tipping trailers, and thus the first and second trailers have braking and cargo box driving components. This double-trailer mining dump truck can be a wide-body double-trailer mining dump truck.

[0030] In one exemplary embodiment, the tractor unit includes a steering gear, a hydraulic tank (i.e., a tractor unit hydraulic pump station), a constant pressure variable pump, a parking brake, a service brake, a steering accumulator, and a brake accumulator.

[0031] The first and second trailers may include service brakes, cargo box lifting cylinders (used to raise or lower one side of the cargo box), side door lifting cylinders (used to open or close the side door of the cargo box), hydraulic oil tanks, and brake accumulators, etc.

[0032] Figure 1 This is a schematic diagram of the hydraulic system of a double-trailer mining dump truck provided in an embodiment of this application. The double-trailer mining dump truck includes a tractor, a first trailer, and a second trailer. The hydraulic system of the double-trailer mining dump truck includes: a tractor hydraulic unit 10, which includes a steering priority valve 11, an overflow valve 12, a first check valve 13, a first ball valve 14, a second ball valve 15, a first pressure reducing valve 16, a first solenoid directional valve 17, a first port d1, a second port d2, a third port d3, and a fourth port d4.

[0033] The steering priority valve 11 is connected to the second port d2, the outlet of the first check valve 13 and the third port d3 respectively. The second port d2 is connected to the oil inlet of the steering gear of the tractor vehicle, the third port d3 is connected to the control port of the steering gear, and the return port of the steering gear is connected to the fourth port d4.

[0034] The overflow valve 12 is connected to the outlet of the first check valve 13 and the fourth port d4, respectively.

[0035] The first ball valve 14 is connected to the outlet of the first check valve 13 and the fourth port d4. The inlet of the first check valve 13 is connected to the first port d1, which is connected to the constant pressure variable pump in the double-trailer mining dump truck. The constant pressure variable pump can be located in the hydraulic pump station of the tractor.

[0036] The second ball valve 15 is connected to the fourth port d4 and the oil inlet P of the first pressure reducing valve 16, respectively.

[0037] The return port T of the first pressure reducing valve 16 is connected to the return port T of the first solenoid directional valve 17, the working port A is connected to the inlet port p of the first solenoid directional valve 17, and the working port A of the first solenoid directional valve 17 is connected to the parking brake of the tractor.

[0038] Hydraulic oil from the constant pressure variable pump flows in through the first port d1, passes through the first pressure reducing valve 16 and the first solenoid directional valve 17, and flows to the port X1 of the parking brake of the tractor vehicle. The port X1 of the parking brake of the tractor vehicle is connected to the parking brake of the tractor vehicle, so that hydraulic oil can be supplied to the parking brake of the tractor vehicle to realize the parking brake function.

[0039] In addition, the constant pressure variable pump and the gear pump in the hydraulic pump station of the tractor are connected to the motor drive shaft through a spline. The hydraulic oil provided by the constant pressure variable pump flows into the hydraulic unit 10 of the tractor (the hydraulic unit 10 can be the steering brake valve group of the hydraulic pump station of the tractor) through the first port d1, and then flows into the P port (oil inlet) of the steering gear through the second port d2. The Ls port (control port) of the steering gear is connected to the third port d3, and the T port (oil return port) of the steering gear is connected to the fourth port d4 for steering return oil. In this way, the valve group structure can realize the function of controlling the steering gear of the tractor to achieve steering.

[0040] In summary, the embodiments of this application provide a hydraulic system for a double-trailer mining dump truck. The system includes a tractor hydraulic unit, which includes an overflow valve 11, a flow divider / combiner valve, a first check valve, a first ball valve, a second ball valve, a first pressure reducing valve, a first solenoid directional valve, and some ports. The system is connected to the tractor's steering gear, constant pressure variable pump, and parking brake, and can supply hydraulic oil to the parking brake and steering gear based on the hydraulic oil supplied by the constant pressure variable pump. In this way, steering and braking functions can be realized through the hydraulic system, enriching the functions that the hydraulic system can achieve.

[0041] In addition, the steering and braking system uses a constant pressure variable pump for pressure supply, which can reduce the energy consumption of the whole vehicle and extend the service life of hydraulic components.

[0042] The pressure reducing valve involved in the embodiments of this application can be used to reduce the input high-pressure hydraulic oil to the stable low pressure required by the system, and maintain the outlet pressure basically constant, unaffected by inlet pressure fluctuations and outlet flow changes.

[0043] In one exemplary embodiment, the hydraulic system of the dual-trailer mining dump truck further includes a first proportional pressure reducing valve 18, a second proportional pressure reducing valve 19, a fifth port d5, and a sixth port d6.

[0044] The first proportional pressure reducing valve 18 is connected to the return port T of the first solenoid directional valve 17, the inlet port P of the first pressure reducing valve 16, and the fifth port d5. The fifth port d5 is connected to the service brake of the tractor vehicle.

[0045] The second proportional pressure reducing valve 19 is connected to the return port T of the first solenoid directional valve 17, the inlet port P of the first pressure reducing valve 16, and the sixth port d6. The sixth port d6 is connected to the service brake of the first trailer. The proportional pressure reducing valve involved in this application embodiment can continuously and accurately adjust the output hydraulic oil pressure according to the proportional change of the input electrical signal (such as current or voltage), realize the linear correspondence between pressure and electrical signal, and maintain stable outlet pressure.

[0046] The constant-pressure variable pump hydraulic oil is connected to the tractor's service brake via the first port d1, the third check valve 191, and the first proportional pressure reducing valve 18, thereby supplying hydraulic oil to the tractor's service brake to control it. Additionally, the constant-pressure variable pump hydraulic oil is connected to the first trailer's service brake via the first port d1, the third check valve 191, and the second proportional pressure reducing valve 19, thereby supplying hydraulic oil to the first trailer's service brake to control it. This allows for continuous control of the tractor's and trailer's service brake pressures.

[0047] In one exemplary embodiment, the hydraulic system of the dual-trailer mining dump truck further includes a seventh port d7, which is connected to the steering accumulator of the tractor and the outlet of the first one-way valve 13. Hydraulic oil from the constant-pressure variable pump flows in through the first port d1, and then through the first one-way valve 13 and the seventh port d7 into the steering accumulator. During rapid steering, the steering accumulator flows into the tractor's hydraulic unit 10 through the seventh port d7, replenishing the steering gear with hydraulic oil, thus enhancing the steering power. It can also absorb system pressure pulses, allowing for the selection of a small-displacement constant-pressure variable pump.

[0048] In one exemplary embodiment, the system further includes: a first manual pump b1 and a tenth port d10, the tenth port d10 being connected to one end of the first manual pump b1 and the hydraulic pump station tank of the tractor, and the other end of the first manual pump being connected to the oil inlet P of the first pressure reducing valve 16.

[0049] In one exemplary embodiment, the hydraulic system of the dual-trailer mining dump truck further includes an eighth port d8, which is connected to the brake accumulator of the tractor unit. The oil inlet P of the first pressure reducing valve 16 is connected to the eighth port d8. Hydraulic oil supplied by the constant pressure variable pump flows into the brake accumulator through the third check valve 191 and the eighth port d8, providing hydraulic oil during emergency braking to enhance the braking capacity of the parking brake. The steering gear can be depressurized through the first ball valve 14, and the parking brake can be depressurized through the second ball valve 15. In an emergency, the parking brake can be released through the first manual pump b1.

[0050] In one exemplary embodiment, the hydraulic system of the double-trailer mining dump truck further includes a ninth port d9, which is connected to a fourth port d4. The ninth port d9 is also connected to a radiator in the tractor unit. The radiator has an oil temperature controller, which is used to activate the radiator when the oil temperature in the radiator is greater than or equal to a first specified temperature. For example, the first specified temperature can be 44 degrees Celsius, and the radiator is a fan radiator. The oil temperature controller can control the fan radiator to operate at a first speed when the oil temperature in the radiator is greater than or equal to 44 degrees Celsius. Additionally, the oil temperature controller is also used to control the fan radiator to operate at a second speed when the oil temperature in the radiator is greater than or equal to a second specified temperature. The second specified temperature is greater than the first specified temperature, for example, 55 degrees Celsius, and the second speed is greater than the first speed, for example, the second speed can be the maximum speed of the fan radiator. This achieves the effect of reducing oil temperature and improving the overall stability of the system.

[0051] In one exemplary embodiment, the first preset port X2 is a pressure testing connector, the second preset port X3 is connected to a pressure sensor to monitor the parking brake pressure and determine whether the parking brake has been released, the third preset port X4 is connected to the brake of the first trailer, the fourth preset port X5 is a pressure testing connector, the fifth preset port MA1 is connected to a pressure sensor to monitor the service brake pressure of the tractor, the sixth preset port MA2 is connected to a pressure sensor to monitor the service brake pressure of the first trailer, the tenth port d10 is connected to the hydraulic pump station oil tank of the tractor for manual pump oil suction, the seventh preset port M2 is connected to a pressure sensor, and the eighth preset port M1 and the ninth port M3 are connected to the pressure testing connector.

[0052] In one exemplary embodiment, please refer to Figure 2 , Figure 2This is a schematic diagram of the hydraulic system of another double-trailer mining dump truck provided in this application embodiment. The hydraulic system of the double-trailer mining dump truck further includes: two trailer hydraulic pump station lifting valve groups 20 corresponding to the first trailer and the second trailer, respectively; each trailer hydraulic pump station lifting valve group 20 includes a second solenoid directional valve 21, a first two-position three-way directional valve 22, a second two-position three-way directional valve 23, a first diverter valve 24, a second diverter valve 25, an eleventh port d11, a twelfth port d12, a thirteenth port d13, a fourteenth port d14, a fifteenth port d15, and a sixteenth port d16.

[0053] The return port T of the second solenoid directional valve 21 is connected to the sixteenth port d16, which is connected to the trailer's hydraulic oil tank. The working port A of the second solenoid directional valve 21 is connected to the control ports of the first two-position three-way directional valve 22 and the second two-position three-way directional valve 23. The inlet port p of the second solenoid directional valve 21 is connected to the eleventh port d11, which is connected to the trailer's gear pump. The gear pump is connected to the trailer's hydraulic oil tank and can supply high-pressure oil (pressure greater than 18 MPa) to the eleventh port.

[0054] The first port of the first two-position three-way directional valve 22 is connected to the thirteenth port d13, which is connected to the trailer's lifting valve. The second port of the first two-position three-way directional valve 22 is connected to the fourteenth port d14, and the third port is connected to the fifteenth port d15. The fourteenth port d14 is connected to the trailer's cargo box lifting cylinder, and the fifteenth port d15 is connected to the trailer's side door lifting cylinder. The control return port of the first two-position three-way directional valve 22 is connected to the sixteenth port d16. The control ports of the first two-position three-way directional valve 22 and the second two-position three-way directional valve 23 are used to control the connection between the first and second ports, or between the first and third ports. This allows for the switching of control between the cargo box lifting cylinder and the side door lifting cylinder. The first valve port of the second two-position three-way directional valve 23 is connected to the twelfth port d12, and the twelfth port d12 is connected to the lifting valve of the trailer. The second valve port of the second two-position three-way directional valve 23 is connected to the second diverter valve 25, and the second diverter valve 25 is connected to the cargo box lifting cylinder of the trailer. The third valve port of the second two-position three-way directional valve 23 is connected to the first diverter valve 24, and the first diverter valve 24 is connected to the side door lifting cylinder of the trailer. The control return port of the second two-position three-way directional valve 23 is connected to the sixteenth port d16.

[0055] Among them, the gear pumps of the first trailer hydraulic pump station and the second trailer hydraulic pump station are connected to the motor drive shaft through splines. The hydraulic oil enters the second solenoid directional valve 21 through the eleventh port d11, which pushes the first two-position three-way directional valve 22 and the second two-position three-way directional valve 23 to switch the operation of the trailer's cargo box lifting cylinder and the trailer's side door lifting cylinder. The trailer also includes a lifting valve, which is connected to port 12 (d12) and port 13 (d13). When the lifting valve is in the lifting position, the hydraulic oil supplied by the lifting valve flows from port 12 (d12) into the trailer hydraulic pump station lifting valve assembly 20, and returns from port 13 (d13). Similarly, when the lifting valve is in the lowering position, the hydraulic oil flows in from port 13 (d13) and returns from port 12 (d12). The oil then flows through the second two-position three-way directional valve 23 and the first diverter / combiner valve 24 into the side door lifting cylinders, and returns from port 14 (d14) and port 15 (d15) through the first two-position three-way directional valve 22 to open the side door. Additionally, there are two cargo box lifting cylinders, each connected to the second port of the second two-position three-way directional valve 23; and two side door lifting cylinders, each connected to the third port of the second two-position three-way directional valve 23.

[0056] The first cargo box lifting cylinder port A1 and the second cargo box lifting cylinder port B1 are respectively connected to two cargo box lifting cylinders to control the lifting of the cargo box so that the cargo box can be tilted. During lifting, oil enters the first cargo box lifting cylinder port A1 and the second cargo box lifting cylinder port B1, and returns through the fourteenth port d14, the first two-position three-way reversing valve 22 and the thirteenth port d13. During lowering, oil returns through the first cargo box lifting cylinder port A1, the second cargo box lifting cylinder port B1, the second diverter valve 25, the second two-position three-way reversing valve 23 and the twelfth port d12, and enters through the fourteenth port d14.

[0057] Similarly, the first side door lifting cylinder port A2 and the second side door lifting cylinder port B2 are respectively connected to two side door lifting cylinders to control the lifting of the side door of the cargo box.

[0058] The first diversion and mixing valve 24 ensures that the two side door lifting cylinders operate synchronously, preventing twisting during side door operation. The second diversion and mixing valve 25 ensures that the two cargo box lifting cylinders operate synchronously, preventing twisting during cargo box operation.

[0059] Please refer to Figure 3 , Figure 3This is a schematic diagram of the hydraulic system of another double-trailer mining dump truck provided in this application embodiment. The hydraulic system of the double-trailer mining dump truck also includes a second trailer hydraulic pump station brake valve group 30 installed on the second trailer. The second trailer hydraulic pump station brake valve group includes a second manual pump 31, a second pressure reducing valve 32, a third solenoid directional valve 33, a third ball valve 34, a third proportional pressure reducing valve 35, a second check valve 36, a seventeenth port d17, an eighteenth port d18, a nineteenth port d19, a twentieth port d20, a twenty-first port d21, a twenty-second port d22, and a twenty-third port d23.

[0060] The second manual pump 31 is connected to the seventeenth port d17 and the working oil port A of the second pressure reducing valve 32 respectively. The seventeenth port d17 is connected to the hydraulic oil tank of the second trailer, and the nineteenth port d19 is connected to the parking brake of the second trailer.

[0061] The oil inlet p of the second pressure reducing valve 32 is connected to the oil outlet of the second check valve 36, and the oil return port T of the second pressure reducing valve 32 is connected to the twenty-third port d23. The twenty-third port d23 is connected to... Figure 1 The 25th port d25 of the hydraulic unit of the tractor shown is connected to the return port T of the first solenoid directional valve 17.

[0062] The oil inlet p of the third solenoid directional valve 33 is connected to the working oil port A of the second pressure reducing valve 32. The working oil port A of the third solenoid directional valve 33 is connected to the nineteenth port d19. The oil return port T of the third solenoid directional valve 33 is connected to the twenty-third port d23.

[0063] One end of the third ball valve 34 is connected to the twenty-third port d23, and the other end of the third ball valve 34 is connected to the oil inlet p of the second pressure reducing valve 32.

[0064] The third proportional pressure reducing valve 35 is connected to the other end of the third ball valve 34, the twenty-third port d23 and the twenty-first port d21 respectively. The twenty-first port d21 is connected to the service brake of the second trailer. The twenty-second port d22 is connected to the twenty-first port d21 and the pressure sensor respectively.

[0065] The inlet of the second one-way valve 36 is connected to the eighteenth port d18, and the outlet is connected to the other end of the third ball valve 34 and the twentieth port d20. The twentieth port d20 is connected to the brake accumulator of the second trailer.

[0066] In one exemplary embodiment, please refer to Figure 1 and Figure 3The hydraulic system of the double-trailer mining dump truck also includes a third check valve 191 and a twenty-fourth port d24. The inlet of the third check valve 191 is connected to the first port d1, and the outlet of the third check valve 191 is connected to the twenty-fourth port d24. The twenty-fourth port d24 is also connected to one end of the first manual pump and the eighteenth port d18 of the brake valve group of the second trailer hydraulic pump station.

[0067] The eighteenth port d18 of the brake valve assembly of the second trailer hydraulic pump station is connected to... Figure 1 The tractor unit's hydraulic pump station's steering brake valve assembly is connected to port 24 (d24), allowing it to provide brake pressure to the second trailer. Port 23 (d23) is connected to port 25 (d25) of the tractor unit's hydraulic system. Port 20 (d20) is connected to a brake accumulator, increasing the hydraulic service brake response speed of the second trailer.

[0068] Simultaneously, it can provide pressurized oil to the second trailer brake in emergencies. Port 19 (d19) is connected to the second trailer parking brake; when the vehicle is in motion, the first solenoid directional valve 17 is energized, releasing the parking brake. Port 21 (d21), connected to the third proportional pressure reducing valve 35, is connected to the second trailer's service brake, enabling continuous control of the service brake pressure. Port 22 (d22) is connected to a pressure sensor to monitor the service brake pressure. Port 17 (d17) is connected to the second trailer's hydraulic oil tank; in case of hydraulic pump failure, the parking brake can be manually released via the second manual pump 31. During maintenance, the third ball valve 34 can be used to release pressure. Trailer port F1 is connected to the pressure sensor.

[0069] The hydraulic system of the dual-trailer mining dump truck provided in this application embodiment can include a tractor hydraulic pump station, a first trailer hydraulic pump station, and a second trailer hydraulic pump station, saving installation space for the entire vehicle's hydraulic system and facilitating its installation and maintenance. Furthermore, the tractor hydraulic pump station, the first trailer hydraulic pump station, and the second trailer hydraulic pump station are independent of each other, isolating the vehicle's hydraulic steering, braking, and lifting functions. When there is no lifting task, the lifting motor is in a stopped state, effectively saving overall vehicle energy consumption and improving the safety and reliability of the entire vehicle's hydraulic system.

[0070] In summary, the embodiments of this application provide a hydraulic system for a double-trailer mining dump truck. The system includes a tractor hydraulic unit, which includes an overflow valve, a flow divider / combiner valve, a first check valve, a first ball valve, a second ball valve, a first pressure reducing valve, a first solenoid directional valve, and some ports. The system is connected to the tractor's steering gear, constant pressure variable pump, and parking brake, and can supply hydraulic oil to the parking brake and steering gear based on the hydraulic oil supplied by the constant pressure variable pump. In this way, steering and braking functions can be realized through the hydraulic system, enriching the functions that the hydraulic system can achieve.

[0071] In addition, the steering and braking system uses a constant pressure variable pump for pressure supply, which can reduce the energy consumption of the whole vehicle and extend the service life of hydraulic components.

[0072] In this application, the terms “first,” “second,” “third,” and “fourth,” etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term “multiple” means two or more, unless otherwise expressly defined.

[0073] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A hydraulic system for a double-trailer mining dump truck, characterized in that, This is used for a double-trailer mining dump truck, which includes a tractor, a first trailer, and a second trailer; The hydraulic system of the double-trailer mining dump truck includes: a tractor hydraulic unit, which includes an overflow valve, a flow divider / combiner valve, a first check valve, a first ball valve, a second ball valve, a first pressure reducing valve, a first solenoid directional valve, a first port, a second port, a third port, and a fourth port. The overflow valve is connected to the second port, the outlet of the first check valve, and the third port respectively. The second port is connected to the oil inlet of the steering gear of the tractor vehicle, the third port is connected to the control port of the steering gear, and the oil return port of the steering gear is connected to the fourth port. The diversion and combination valve is connected to the outlet of the first one-way valve and the fourth port, respectively. The first ball valve is connected to the outlet of the first check valve and the fourth port respectively. The inlet of the first check valve is connected to the first port. The first port is connected to the constant pressure variable pump in the double-trailer mining dump truck. The second ball valve is connected to the fourth port and the oil inlet of the first pressure reducing valve, respectively; The return port of the first pressure reducing valve is connected to the return port of the first solenoid directional valve, the working port is connected to the inlet port of the first solenoid directional valve, and the working port of the first solenoid directional valve is connected to the parking brake of the tractor. The system also includes: two trailer hydraulic pump station lifting valve groups corresponding to the first trailer and the second trailer respectively; Each of the trailer hydraulic pump station lifting valve assemblies includes a second solenoid directional valve, a first two-position three-way directional valve, a second two-position three-way directional valve, a first diverter valve, a second diverter valve, an eleventh port, a twelfth port, a thirteenth port, a fourteenth port, a fifteenth port, and a sixteenth port. The return port of the second electromagnetic directional valve is connected to the sixteenth port, the sixteenth port is connected to the hydraulic oil tank of the trailer, the working port of the second electromagnetic directional valve is connected to the control port of the first two-position three-way directional valve and the second two-position three-way directional valve, the inlet port of the second electromagnetic directional valve is connected to the eleventh port, the eleventh port is connected to the gear pump of the trailer, and the gear pump is connected to the hydraulic oil tank of the trailer. The first valve port of the first two-position three-way reversing valve is connected to the thirteenth port, and the thirteenth port is connected to the lifting valve of the trailer. The second valve port of the first two-position three-way reversing valve is connected to the fourteenth port, and the fourteenth port is connected to the cargo box lifting cylinder of the trailer. The third valve port of the first two-position three-way reversing valve is connected to the fifteenth port, and the fifteenth port is connected to the side door lifting cylinder of the trailer. The oil return port of the first two-position three-way reversing valve is connected to the sixteenth port. The first valve port of the second 2-position three-way reversing valve is connected to the 12th port, and the 12th port is connected to the lifting valve of the trailer. The second valve port of the second 2-position three-way reversing valve is connected to the second diverter valve, and the second diverter valve is connected to the cargo box lifting cylinder of the trailer. The third valve port of the second 2-position three-way reversing valve is connected to the first diverter valve, and the first diverter valve is connected to the side door lifting cylinder of the trailer. The return port of the second 2-position three-way reversing valve is connected to the 16th port.

2. The hydraulic system of the double-trailer mining dump truck according to claim 1, characterized in that, The system also includes a first proportional pressure reducing valve, a second proportional pressure reducing valve, a fifth port, and a sixth port; The first proportional pressure reducing valve is connected to the return port of the first electromagnetic reversing valve, the inlet port of the first pressure reducing valve, and the fifth port, respectively. The fifth port is connected to the service brake of the tractor. The second proportional pressure reducing valve is connected to the return port of the first electromagnetic reversing valve, the inlet port of the first pressure reducing valve, and the sixth port, respectively. The sixth port is connected to the service brake of the first trailer.

3. The hydraulic system of the double-trailer mining dump truck according to claim 1, characterized in that, The system further includes a seventh port, which is connected to the steering accumulator of the tractor and the outlet of the first one-way valve.

4. The hydraulic system of the double-trailer mining dump truck according to claim 2, characterized in that, The system also includes an eighth port, which is connected to the brake accumulator of the tractor vehicle, and the oil inlet of the first pressure reducing valve is connected to the eighth port.

5. The hydraulic system of the double-trailer mining dump truck according to claim 1, characterized in that, The system also includes a ninth port, which is connected to the fourth port; The ninth port is also connected to a radiator in the tractor, which has an oil temperature controller for activating the radiator when the oil temperature in the radiator is greater than or equal to a first specified temperature.

6. The hydraulic system of the double-trailer mining dump truck according to claim 2, characterized in that, The system also includes a first manual pump and a tenth port, wherein the tenth port is connected to the first port, one end of the first manual pump and the oil tank of the tractor hydraulic pump station, and the other end of the first manual pump is connected to the oil inlet of the first pressure reducing valve.

7. The hydraulic system of the double-trailer mining dump truck according to claim 1, characterized in that, The number of cargo box lifting cylinders is 2, and the two cargo box lifting cylinders are respectively connected to the second valve port of the second two-position three-way reversing valve; The number of side door lifting cylinders is 2, and the two side door lifting cylinders are respectively connected to the third valve port of the second two-position three-way reversing valve.

8. The hydraulic system of the double-trailer mining dump truck according to claim 6, characterized in that, The system also includes a second trailer hydraulic pump station brake valve assembly installed on the second trailer. The second trailer hydraulic pump station brake valve assembly includes a second manual pump, a second pressure reducing valve, a third solenoid directional valve, a third ball valve, a third proportional pressure reducing valve, a second check valve, a seventeenth port, an eighteenth port, a nineteenth port, a twentieth port, a twenty-first port, a twenty-second port, and a twenty-third port. The second manual pump is connected to the seventeenth port and the working oil port of the second pressure reducing valve, the seventeenth port is connected to the hydraulic oil tank of the second trailer, and the nineteenth port is connected to the parking brake of the second trailer. The oil inlet of the second pressure reducing valve is connected to the oil outlet of the second check valve, the oil return port of the second pressure reducing valve is connected to the twenty-third port, the twenty-third port is connected to the twenty-third port of the tractor hydraulic unit, and the twenty-third port is connected to the oil return port of the first solenoid directional valve. The oil inlet of the third solenoid directional valve is connected to the working oil port of the second pressure reducing valve, the working oil port of the third solenoid directional valve is connected to the nineteenth port, and the oil return port of the third solenoid directional valve is connected to the twenty-third port. One end of the third ball valve is connected to the twenty-third port, and the other end of the third ball valve is connected to the oil inlet of the second pressure reducing valve; The third proportional pressure reducing valve is connected to the other end of the third ball valve, the second thirteenth port and the second eleventh port respectively. The second eleventh port is connected to the service brake of the second trailer, and the second twelfth port is connected to the second eleventh port and the pressure sensor respectively. The inlet of the second one-way valve is connected to the eighteenth port, and the outlet is connected to the other end of the third ball valve and the twentieth port. The twentieth port is connected to the brake accumulator of the second trailer.

9. The hydraulic system of the double-trailer mining dump truck according to claim 8, characterized in that, The tractor hydraulic unit also includes a third check valve and a twenty-fourth port. The inlet of the third check valve is connected to the first port, and the outlet of the third check valve is connected to the twenty-fourth port. The twenty-fourth port is also connected to one end of the first manual pump and the eighteenth port of the brake valve group of the second trailer hydraulic pump station.

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