Traction machine hydraulic system and traction machine

Abstract

The invention relates to the field of line traction construction equipment, and discloses a tractor hydraulic system and a tractor. The motor pump comprises an oil pump assembly and a motor for driving the oil pump assembly, and an oil inlet of the oil pump assembly is connected with the oil tank; the main oil supply path is connected with an oil discharge port of the oil pump assembly and can supply oil to the hydraulic actuating mechanism; the main oil return path can be connected with the oil tank and the hydraulic actuating mechanism; and the brake control valve is used for connecting the pressure control port of the speed reducer brake with the oil discharge port of the oil pump assembly and the oil tank, and can control the speed reducer brake to start and stop. The hydraulic system of the traction machine can solve the problems that an existing traction machine is large in pollution and noise, the transmission efficiency can be improved, and energy consumption can be reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of line traction construction equipment, and specifically relates to a traction machine hydraulic system and a traction machine. Background Art

[0002] The traction machine can be used for traction construction of overhead power lines and other lines. It uses a gasoline engine or a diesel engine to provide power to the hydraulic pump station, and the hydraulic pump station then provides hydraulic power to drive the various hydraulic actuators to operate, thereby achieving different functions.

[0003] However, the existing traction machines are powered by gasoline or diesel engines, which cause heavy pollution, loud noise and poor environmental friendliness. In addition, the gasoline or diesel engine drives the hydraulic pump, which in turn drives the hydraulic actuator, resulting in low transmission efficiency and high energy consumption. Summary of the invention

[0004] The purpose of the present application is to provide a traction machine hydraulic system and a traction machine, which can solve the problems of high pollution and high noise, improve transmission efficiency and reduce energy consumption.

[0005] In order to achieve the above objectives, the present application provides a tractor hydraulic system, which includes:

[0006] tank;

[0007] A motor pump, comprising an oil pump assembly and a motor driving the oil pump assembly, wherein the oil inlet of the oil pump assembly is connected to the oil tank;

[0008] A main oil supply circuit, connected to the oil discharge port of the oil pump assembly and capable of supplying oil to the hydraulic actuator;

[0009] A main oil return line, capable of connecting the oil tank and the hydraulic actuator; and

[0010] The brake control valve is used to connect the pressure control port of the speed reducer brake with the oil discharge port of the oil pump assembly and the oil tank, and can control the opening and closing of the speed reducer brake.

[0011] In some embodiments, the oil pump assembly includes a large-displacement oil pump and a small-displacement oil pump with a displacement smaller than that of the large-displacement oil pump, the oil discharge port of the large-displacement oil pump and the oil discharge port of the small-displacement oil pump are both connected to the main oil supply circuit and the brake control valve, and the tractor hydraulic system also includes a first unloading control valve, and the oil discharge port of the large-displacement oil pump is connected to the main oil return circuit through the first unloading control valve.

[0012] In some embodiments, the tractor hydraulic system further includes a second unloading control valve, and the oil discharge port of the small-displacement oil pump is connected to the main oil return circuit through the second unloading control valve.

[0013] In some embodiments, when the motor starts to start, the first unloading control valve can connect the oil discharge port of the large-displacement oil pump and the main return oil circuit, and the second unloading control valve can connect the oil discharge port of the small-displacement oil pump and the main return oil circuit.

[0014] In some embodiments, the tractor hydraulic system further includes a first pressure sensor capable of detecting a confluence pressure between the main oil supply circuit and the oil discharge port of the large displacement oil pump and the oil discharge port of the small displacement oil pump;

[0015] Under the working condition that the confluence pressure is greater than the preset maximum confluence pressure, the first unloading control valve can conduct the oil discharge port of the large-displacement oil pump and the main oil return line.

[0016] In some embodiments, the tractor hydraulic system further includes a first one-way valve and a second one-way valve, the oil discharge port of the large-displacement oil pump is connected to the brake control valve via the first one-way valve, and the oil discharge port of the small-displacement oil pump is connected to the brake control valve via the second one-way valve.

[0017] In some embodiments, the oil pump assembly includes a load-sensitive variable displacement pump, the main oil supply circuit and the brake control valve are both connected to the oil discharge port of the load-sensitive variable displacement pump, and the traction machine hydraulic system also includes a load feedback oil circuit, which is used to connect the load control port of the load-sensitive variable displacement pump with the hydraulic actuator.

[0018] In some embodiments, the tractor hydraulic system further includes a load feedback relief valve connecting the main oil return circuit and the load feedback circuit.

[0019] In some embodiments, the tractor hydraulic system further comprises a pressure reducing valve with adjustable oil discharge pressure, the oil inlet of the pressure reducing valve is connected to the oil discharge port of the oil pump assembly, the oil discharge port of the pressure reducing valve is connected to the pressure control port of the reduction gear brake through the brake control valve, and the pressure relief port of the pressure reducing valve is connected to the oil tank.

[0020] In some embodiments, the tractor hydraulic system further includes a first pressure sensor capable of detecting an inlet oil pressure of the pressure reducing valve and a second pressure sensor capable of detecting an outlet oil pressure of the pressure reducing valve.

[0021] In some embodiments, under the condition that the oil inlet pressure of the pressure reducing valve is not less than the oil discharge pressure and the oil discharge pressure is within the first preset oil pressure range, the brake control valve can conduct the oil discharge port of the oil pump assembly with the pressure control port of the speed reducer brake;

[0022] Under the condition that the oil inlet pressure of the pressure reducing valve is less than the oil discharge pressure and / or the oil discharge pressure is not within the first preset oil pressure range, the brake control valve cannot connect the oil discharge port of the oil pump assembly with the pressure control port of the speed reducer brake.

[0023] In some embodiments, the tractor hydraulic system further includes a second pressure sensor capable of detecting the drain oil pressure of the pressure reducing valve and a third pressure sensor capable of detecting the oil pressure of the pressure control port of the speed reducer brake;

[0024] Under the working condition that the discharge oil pressure of the pressure reducing valve is equal to the oil pressure of the pressure control port of the speed reducer brake and the discharge oil pressure of the pressure reducing valve is within the second preset oil pressure range, the speed reducer brake can be started;

[0025] Under the condition that the discharge oil pressure of the pressure reducing valve is not equal to the oil pressure of the pressure control port of the speed reducer brake and / or the discharge oil pressure of the pressure reducing valve is not within the second preset oil pressure range, the speed reducer brake cannot be started.

[0026] In some embodiments, the tractor hydraulic system further includes a third pressure sensor for detecting the oil pressure of a pressure control port of a reduction machine brake.

[0027] In some embodiments, under the condition that the motor needs to be started and the oil pressure at the pressure control port of the speed reducer brake is not greater than the preset maximum starting oil pressure, the motor can be started; under the condition that the motor needs to be started and the oil pressure at the pressure control port of the speed reducer brake is greater than the preset maximum starting oil pressure, the motor cannot be started.

[0028] A second aspect of the present application further provides a tractor, which includes the above-mentioned tractor hydraulic system.

[0029] Through the above technical solution, the tractor hydraulic system of the present application uses the motor as the power source, and the motor can drive the oil pump assembly to operate, so that the oil pump assembly produces a pumping action to suck the hydraulic oil in the oil tank into its oil inlet, and the oil pump assembly can supply the hydraulic oil to the reducer brake through the brake control valve through its oil discharge port, and can also supply the hydraulic oil to the hydraulic actuator through the main oil supply oil circuit, so as to open the reducer brake or drive the hydraulic actuator. It can be seen that the tractor hydraulic system of the present application has no pollution emissions when in use, low noise, clean and environmentally friendly, and compared with the use of fuel power source, the use of the motor as the power source has high transmission efficiency and reduced energy consumption.

[0030] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without creative work. In the drawings:

[0032] Figure 1 A schematic diagram of a traction machine hydraulic system, a multi-way valve, a speed reducer brake, and a plurality of hydraulic actuators in a specific implementation manner of the present application;

[0033] Figure 2 It is a schematic diagram of another traction machine hydraulic system, a multi-way valve, a speed reducer brake and multiple hydraulic actuators in a specific implementation manner of the present application.

[0034] Description of Reference Numerals

[0035] 1 Hydraulic pump station 2 Multi-way valve

[0036] 3 Reducer brake 4 Tail rope bracket motor

[0037] 5. Flipping cylinder 6. Pressing cylinder

[0038] 7 Outrigger Cylinder

[0039] 11 Fuel tank 12 Fuel pump assembly

[0040] 13 Motor 14 Control valve group

[0041] 15 First pressure sensor 16 Second pressure sensor

[0042] 17 Third pressure sensor

[0043] 121 Large displacement oil pump 122 Small displacement oil pump

[0044] 123 Load sensing variable pump 141 Main oil supply line

[0045] 142 Main oil return line 143 Load feedback oil line

[0046] 144 Brake control valve 145 First unloading control valve

[0047] 146 Second unloading control valve 147 First check valve

[0048] 148 Second check valve 149 Load feedback relief valve

[0049] 1410 pressure reducing valve 1411 oil supply relief valve

[0050] 1412 Auxiliary oil supply line 1413 Auxiliary oil return line DETAILED DESCRIPTION

[0051] The specific implementation of the present application is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present application, and is not used to limit the present application.

[0052] Reference Figure 1 and Figure 2 The first exemplary embodiment of the present application provides a tractor hydraulic system, which includes an oil tank 11 , a motor pump, a main oil supply circuit 141 , a main oil return circuit 142 and a brake control valve 144 .

[0053] Specifically, the motor pump includes an oil pump assembly 12 and a motor 13 driving the oil pump assembly 12. The oil inlet of the oil pump assembly 12 is connected to the oil tank 11. The motor 13 can drive the oil pump assembly 12 to operate, so that the oil pump assembly 12 generates a pumping action to suck the hydraulic oil in the oil tank 11 into its oil inlet.

[0054] In addition, the main oil supply circuit 141 is connected to the oil discharge port of the oil pump assembly 12. The oil pump assembly 12 can pump the hydraulic oil to the main oil supply circuit 141 through its oil discharge port. Then the main oil supply circuit 141 can supply the hydraulic oil to the hydraulic actuator in the tractor (for example, the tail rope frame motor 4, the tilting cylinder 5, the wire pressing cylinder 6 and the outrigger cylinder 7 of the tractor), so as to drive the hydraulic actuator to operate. The main oil return circuit 142 can connect the oil tank 11 and the hydraulic actuator. When the hydraulic actuator operates, the hydraulic oil discharged by the hydraulic actuator can flow back to the oil tank 11 through the main oil return circuit 142.

[0055] Usually, the tail rope frame motor 4, the tilting cylinder 5, the wire pressing cylinder 6 and the outrigger cylinder 7 do not work at the same time and can be started and stopped independently of each other. The tail rope frame motor 4 is used to drive the tail rope frame in the traction machine to rotate to retract and release the wire wound on the tail rope frame, the tilting cylinder 5 is used to drive the tail rope frame to flip up and down as a whole to adjust the height of the tail rope frame from the ground, the wire pressing cylinder 6 is used to press the wire, and the outrigger cylinder 7 is used to achieve the leveling of the traction machine.

[0056] In addition, the brake control valve 144 is used to connect the pressure control port (i.e., Br port) of the reducer brake 3 in the traction machine with the oil discharge port of the oil pump assembly 12 and the oil tank 11, and can control the opening and closing of the reducer brake 3. More specifically, when the traction machine needs to use its line traction function, the reducer in the traction machine is required to be in the starting state, and the reducer needs to be started, which requires the reducer brake 3 to be opened. Therefore, at this time, the oil pump assembly 12 can supply oil to the pressure control port of the reducer brake 3 through its oil discharge port through the brake control valve 144, so that the pressure control port of the reducer brake 3 is pressurized, and then the reducer brake 3 is opened. At this time, the reducer of the traction machine can operate, and the traction machine can use its line traction function. When the reducer needs to stop running, the reducer brake 3 is required to be closed. Therefore, at this time, the oil pump assembly 12 stops running, and the reducer brake 3 can return oil to the oil tank 11 through its pressure control port through the brake control valve 144, so that the pressure control port of the reducer brake 3 is relieved, the reducer brake 3 is closed, and the reducer can stop running.

[0057] As an example, the brake control valve 144 may be a two-position four-way electromagnetic reversing valve. When the two-position four-way electromagnetic reversing valve is energized, the oil discharge port of the oil pump assembly 12 may be connected to the pressure control port of the speed reducer brake 3. At this time, the two-position four-way electromagnetic reversing valve controls the speed reducer brake 3 to open. When the two-position four-way electromagnetic reversing valve loses power, the pressure control port of the speed reducer brake 3 may be connected to the oil tank 11. At this time, the oil discharge port of the oil pump assembly 12 is not connected to the pressure control port of the speed reducer brake 3, so that the pressure control port of the speed reducer brake 3 is depressurized and the speed reducer brake 3 is closed. Of course, the brake control valve 144 may also be other types of valves, and the present application does not limit this.

[0058] Through the above arrangement, the traction machine hydraulic system of the present application uses the motor 13 as a power source, has no pollution emissions when in use, has low noise, is clean and environmentally friendly, and has high transmission efficiency and reduced energy consumption compared to fuel power sources.

[0059] In some embodiments, reference Figure 1 , the oil pump assembly 12 may include a large displacement oil pump 121 and a small displacement oil pump 122 whose displacement is smaller than that of the large displacement oil pump 121. In this case, the oil discharge port of the oil pump assembly 12 includes the oil discharge port of the large displacement oil pump 121 and the oil discharge port of the small displacement oil pump 122. Among them, the main oil supply oil circuit 141 and the brake control valve 144 are both connected to the oil discharge port of the large displacement oil pump 121, and the main oil supply oil circuit 141 and the brake control valve 144 are both connected to the oil discharge port of the small displacement oil pump 122. In other words, the hydraulic oil pumped out of the oil discharge port of the large displacement oil pump 121 and the hydraulic oil pumped out of the oil discharge port of the small displacement oil pump 122 can first converge and then flow to the main oil supply oil circuit 141 and the brake control valve 144.

[0060] In addition, the traction machine hydraulic system may also include a first unloading control valve 145, and the oil discharge port of the large-displacement oil pump 121 is connected to the main oil return circuit 142 through the first unloading control valve 145, so the first unloading control valve 145 can open or cut off the connection between the oil discharge port of the large-displacement oil pump 121 and the main oil return circuit 142.

[0061] When the speed reducer brake 3 needs to be opened, the first unloading control valve 145 needs to cut off the oil discharge port of the large-displacement oil pump 121 and the main return oil circuit 142, so that the hydraulic oil discharged from the large-displacement oil pump 121 can be merged with the hydraulic oil discharged from the small-displacement oil pump 122, so that the brake control valve 144 can supply the merged hydraulic oil to the pressure control port of the speed reducer brake 3, thereby controlling the opening of the speed reducer brake 3.

[0062] Since the traction machine generally requires a faster retraction and release speed but a lower load requirement when retracting and releasing the line, the tail rope frame motor 4 generally operates under a large flow and low pressure condition, while the turning cylinder 5, the line pressing cylinder 6 and the outrigger cylinder 7 have a larger load but a low speed requirement, and therefore generally operate under a small flow and high pressure condition.

[0063] It can be seen that the tail rope frame motor 4 needs to work under a high-flow and low-pressure condition. Therefore, when the tail rope frame motor 4 is running, the first unloading control valve 145 needs to cut off the oil discharge port of the large-displacement oil pump 121 and the main oil return oil circuit 142, so that the hydraulic oil discharged by the large-displacement oil pump 121 can be merged with the hydraulic oil discharged by the small-displacement oil pump 122, so that the main oil supply oil circuit 141 can supply the hydraulic oil with a large flow and low pressure to the tail rope frame motor 4.

[0064] The flipping cylinder 5, the wire pressing cylinder 6 and the outrigger cylinder 7 need to work under low flow and high pressure conditions. Therefore, when any one of the flipping cylinder 5, the wire pressing cylinder 6 and the outrigger cylinder 7 is in operation, the first unloading control valve 145 needs to connect the oil discharge port of the large-displacement oil pump 121 and the main return oil circuit 142, so that the hydraulic oil discharged by the large-displacement oil pump 121 can directly flow back to the oil tank 11 through the main return oil circuit 142. At this time, the hydraulic oil in the main oil supply circuit 141 only comes from the small-displacement oil pump 122. Therefore, the main oil supply circuit 141 can supply low-flow and high-pressure hydraulic oil to any one of the flipping cylinder 5, the wire pressing cylinder 6 and the outrigger cylinder 7.

[0065] It should be noted that, since the flow and pressure of the hydraulic oil flowing through the brake control valve 144 and the main oil supply circuit 141 can be controlled by switching the on-off state of the first unloading control valve 145 in this embodiment, both the large displacement oil pump 121 and the small displacement oil pump 122 can use a fixed displacement pump, such as a fixed displacement gear pump, etc., but this application does not limit the large displacement oil pump 121 and the small displacement oil pump 122 to use a variable displacement pump. Moreover, this application does not limit the number of motors 13. For example, when only one motor 13 is provided, the large displacement oil pump 121 and the small displacement oil pump 122 connected in series can be driven by the motor 13 at the same time; when two motors 13 are provided, the large displacement oil pump 121 and the small displacement oil pump 122 can be driven independently by the two motors 13 respectively.

[0066] In addition, the first unloading control valve 145 can be a two-position two-way electromagnetic reversing valve, which conducts the oil discharge port of the large-displacement oil pump 121 and the main oil return oil path 142 when the two-position two-way electromagnetic reversing valve is energized, and cuts off the oil discharge port of the large-displacement oil pump 121 and the main oil return oil path 142 when the two-position two-way electromagnetic reversing valve is de-energized. Of course, the present application does not limit the first unloading control valve 145 to other types of valves.

[0067] Through the arrangement of this embodiment, since the flow and pressure of the hydraulic oil flowing through the brake control valve 144 and the main oil supply oil circuit 141 can be controlled by switching the on-off state of the first unloading control valve 145, the different flow and pressure requirements of the reducer brake 3 and different hydraulic actuators in the tractor for the hydraulic oil can be better met. In this way, the motor 13 can use a small-power motor with constant power (of course, the present application does not exclude the use of a high-power motor), so that the size of the motor 13 is small, which can reduce the overall space occupied by the tractor hydraulic system and reduce the production and manufacturing costs. When the tractor hydraulic system of the present application is integrated into a hydraulic pump station that can be transported independently, the transportation cost and transportation difficulty of the hydraulic pump station can be reduced; when the tractor hydraulic system of the present application is installed and fixed on the tractor, the overall transportation cost and transportation difficulty of the tractor can be reduced.

[0068] In some embodiments, the traction machine hydraulic system may further include a second unloading control valve 146 , and the oil discharge port of the small-displacement oil pump 122 is connected to the main oil return circuit 142 through the second unloading control valve 146 , so the second unloading control valve 146 can open or cut off the connection between the oil discharge port of the small-displacement oil pump 122 and the main oil return circuit 142 .

[0069] When the reducer brake 3 needs to be opened, not only the first unloading control valve 145 needs to cut off the oil discharge port of the large-displacement oil pump 121 and the main return oil circuit 142, but the second unloading control valve 146 also needs to cut off the oil discharge port of the small-displacement oil pump 122 and the main return oil circuit 142.

[0070] In addition, the tail rope rack motor 4 needs to work under high flow and low pressure conditions. Therefore, when the tail rope rack motor 4 is running, not only the first unloading control valve 145 needs to cut off the oil discharge port of the large-displacement oil pump 121 and the main oil return oil circuit 142, but the second unloading control valve 146 also needs to cut off the oil discharge port of the small-displacement oil pump 122 and the main oil return oil circuit 142.

[0071] The flipping cylinder 5, the wire pressing cylinder 6 and the outrigger cylinder 7 need to work under small flow and high pressure conditions. Therefore, when any one of the flipping cylinder 5, the wire pressing cylinder 6 and the outrigger cylinder 7 is in operation, the first unloading control valve 145 needs to connect the oil discharge port of the large-displacement oil pump 121 and the main return oil circuit 142, but the second unloading control valve 146 needs to cut off the oil discharge port of the small-displacement oil pump 122 and the main return oil circuit 142.

[0072] It should be noted that the second unloading control valve 146 may be a two-position two-way solenoid reversing valve, which conducts the oil discharge port of the small-displacement oil pump 122 and the main oil return oil circuit 142 when the two-position two-way solenoid reversing valve is energized, and cuts off the connection between the oil discharge port of the small-displacement oil pump 122 and the main oil return oil circuit 142 when the two-position two-way solenoid reversing valve is de-energized. Of course, the present application does not limit the second unloading control valve 146 to other types of valves.

[0073] In some embodiments, when the motor 13 starts to start, the first unloading control valve 145 can connect the oil discharge port of the large-displacement oil pump 121 and the main oil return line 142, and the second unloading control valve 146 can connect the oil discharge port of the small-displacement oil pump 122 and the main oil return line 142. Therefore, when the motor 13 starts to start, the entire traction machine hydraulic system is unloaded to avoid the motor 13 from starting under load, which is beneficial to speed up the acceleration of the motor 13 and protect the motor 13.

[0074] In some embodiments, the traction machine hydraulic system may further include a first pressure sensor 15, which can detect the confluence pressure between the main oil supply circuit 141 and the oil discharge port of the large-displacement oil pump 121 and the oil discharge port of the small-displacement oil pump 122. When the first pressure sensor 15 detects that the confluence pressure is greater than the preset maximum confluence pressure, the first unloading control valve 145 can connect the oil discharge port of the large-displacement oil pump 121 and the main oil return circuit 142, thereby unloading the large-displacement oil pump 121 to avoid overloading the motor 13 driving the large-displacement oil pump 121.

[0075] For example, the tail rope rack motor 4 needs to work under high flow and low pressure conditions. According to the formula P=Qv*Δp / 600 / η (where P is power (kW), Qv is flow (L / min), Δp is pressure (bar), and η is efficiency), when the power is constant, the greater the flow, the lower the pressure. When the traction machine drives the tail rope rack to retract and release the line at the normal maximum speed through the tail rope rack motor 4, the tail rope rack motor 4 requires the maximum flow, and both the large displacement oil pump 121 and the small displacement oil pump 122 need to supply oil to the main oil supply oil circuit 141. However, if the line load changes significantly at this time and the above-mentioned confluence pressure detected by the first pressure sensor 15 is greater than the preset maximum confluence pressure, the first unloading control valve 145 can be connected to the oil discharge port of the large displacement oil pump 121 and the main oil return oil circuit 142 to unload the large displacement oil pump 121, thereby avoiding overloading of the motor 13 and affecting the line retracting and releasing function of the traction machine. At the same time, since the power of the motor 13 can be set to be constant, when the flow of the entire traction machine hydraulic system is reduced due to the unloading of the large-displacement oil pump 121, according to the above formula, the system pressure will gradually increase, so that the system returns to a suitable pressure level.

[0076] In some embodiments, the traction machine hydraulic system may further include a first one-way valve 147 and a second one-way valve 148. In this case, the oil discharge port of the large-displacement oil pump 121 is connected to the brake control valve 144 through the first one-way valve 147, and the oil discharge port of the small-displacement oil pump 122 is connected to the brake control valve 144 through the second one-way valve 148.

[0077] By setting the first one-way valve 147, it can be ensured that when the large-displacement oil pump 121 is unloaded through the first unloading control valve 145, the hydraulic oil discharged by the large-displacement oil pump 121 will not have sufficient oil pressure to conduct the first one-way valve 147 and flow to the brake control valve 144, and when the first unloading control valve 145 is disconnected, the first one-way valve 147 can prevent the oil pressure of the hydraulic oil flowing from the large-displacement oil pump 121 to the brake control valve 144 from being too low.

[0078] Similarly, by providing the second one-way valve 148, it can be ensured that when the small-displacement oil pump 122 is unloaded through the second unloading control valve 146, the hydraulic oil discharged by the small-displacement oil pump 122 will not have sufficient oil pressure to open the second one-way valve 148 and flow to the brake control valve 144, and when the second unloading control valve 146 is disconnected, the second one-way valve 148 can prevent the oil pressure of the hydraulic oil flowing from the small-displacement oil pump 122 to the brake control valve 144 from being too low.

[0079] In some embodiments, reference Figure 2, the oil pump assembly 12 may include a load-sensitive variable pump 123, in which case the oil discharge port of the oil pump assembly 12 includes the oil discharge port of the load-sensitive variable pump 123, and the main oil supply circuit 141 and the brake control valve 144 are both connected to the oil discharge port of the load-sensitive variable pump 123, so the load-sensitive variable pump 123 can supply oil to the main oil supply circuit 141 and the brake control valve 144, and since the load-sensitive variable pump 123 can adjust the displacement, the load-sensitive variable pump 123 can match the different flow and pressure requirements of different hydraulic actuators. At the same time, the first unloading control valve 145, the second unloading control valve 146, the first check valve 147 and the second check valve 148 can be saved, thereby simplifying the system composition.

[0080] In the case where the load-sensitive variable pump 123 is provided, a load feedback oil circuit 143 is also provided in the traction machine hydraulic system, and the load feedback oil circuit 143 is used to connect the load control port of the load-sensitive variable pump 123 and the hydraulic actuator. For example, when any one of the tail rope frame motor 4, the tilting cylinder 5, the wire pressing cylinder 6 and the outrigger cylinder 7 is working, if its working pressure changes, the working pressure can be fed back to the load control port of the load-sensitive variable pump 123 through the load feedback oil circuit 143, and the load-sensitive variable pump 123 can automatically adjust the pump displacement according to the change of the working pressure to match the flow and pressure requirements under different specific working conditions.

[0081] Through the arrangement of this embodiment, since the displacement of the load-sensitive variable pump 123 is adjustable, the different flow and pressure requirements of the reducer brake 3 and different hydraulic actuators in the tractor for the hydraulic oil can be met. Therefore, in this embodiment, the motor 13 can also use a small-power motor with constant power (of course, this application does not exclude the use of a high-power motor), so that the size of the motor 13 is small, which can reduce the overall space occupied by the tractor hydraulic system and reduce the production and manufacturing costs. When the tractor hydraulic system of the present application is integrated into a hydraulic pump station that can be transported independently, the transportation cost and transportation difficulty of the hydraulic pump station can be reduced; when the tractor hydraulic system of the present application is installed and fixed on the tractor, the overall transportation cost and transportation difficulty of the tractor can be reduced.

[0082] In some embodiments, the traction machine hydraulic system may further include a load feedback relief valve 149 connecting the main return oil circuit 142 and the load feedback oil circuit 143 . The load feedback relief valve 149 may limit the maximum working pressure of the load feedback oil circuit 143 , thereby achieving safety protection for the load-sensitive variable pump 123 .

[0083] For example, if the load-sensitive variable pump 123 needs to be installed inside the oil tank 11 based on compactness requirements, the maximum cut-off pressure of the load-sensitive variable pump 123 cannot be adjusted at this time. Therefore, the above-mentioned load feedback overflow valve 149 can be set to limit the maximum working pressure of the load feedback oil circuit 143, so that the load-sensitive variable pump 123 can also be safely protected while meeting the compact installation requirements of the load-sensitive variable pump 123 and the oil tank 11.

[0084] It should be noted that the load feedback relief valve 149 may be a relief valve with adjustable opening pressure or a relief valve with constant opening pressure. For example, the load feedback relief valve 149 may be an electric proportional relief valve, in which case the maximum working pressure of the load feedback oil circuit 143 may be adjusted by remote electric control. Of course, the load feedback relief valve 149 may also be other types of valves, which are not limited in the present application.

[0085] In some embodiments, the tractor hydraulic system may further include an oil supply relief valve 1411 connecting the main oil supply circuit 141 and the main oil return circuit 142 . The oil supply relief valve 1411 may prevent overpressure in the main oil supply circuit 141 , thereby improving system safety.

[0086] In some embodiments, the tractor hydraulic system may further include a pressure reducing valve 1410 with adjustable oil discharge pressure, the oil inlet of the pressure reducing valve 1410 is connected to the oil discharge port of the oil pump assembly 12, the oil discharge port of the pressure reducing valve 1410 is connected to the pressure control port of the speed reducer brake 3 through the brake control valve 144, and the pressure relief port of the pressure reducing valve 1410 is connected to the oil tank 11. It can be seen that by providing the pressure reducing valve 1410, the hydraulic oil flowing out of the oil discharge port of the oil pump assembly 12 can be first reduced in pressure by the pressure reducing valve 1410 and then flow into the pressure control port of the speed reducer brake 3 through the brake control valve 144. The oil discharge pressure of the pressure reducing valve 1410 can be set according to the opening pressure range of the speed reducer brake 3. For example, when the opening pressure range of the speed reducer brake 3 is 3MPa to 10MPa, the oil discharge pressure of the pressure reducing valve 1410 can be set within 3MPa to 10MPa (for example, set to 5MPa).

[0087] It should be noted that when the tractor is working, the normal operation of the speed reducer brake 3 is the primary prerequisite for the safe operation of the whole machine. Therefore, in order to ensure the normal opening and closing of the speed reducer brake 3, the pressure at different positions of the tractor hydraulic system can be monitored through the following embodiments, as follows:

[0088] In some embodiments, the tractor hydraulic system may further include a first pressure sensor 15 capable of detecting the inlet oil pressure of the pressure reducing valve 1410 and a second pressure sensor 16 capable of detecting the discharge oil pressure of the pressure reducing valve 1410, so as to monitor the inlet oil pressure and discharge oil pressure of the pressure reducing valve 1410, so as to avoid failure to detect the abnormal pressure in the oil circuit where the brake control valve 144 is located. In addition, combined with the above content, it can be known that the first pressure sensor 15 can be used to detect the confluence pressure between the main oil supply circuit 141 and the discharge ports of the large displacement oil pump 121 and the discharge ports of the small displacement oil pump 122, and can also be used to detect the inlet oil pressure of the pressure reducing valve 1410, so it has multiple detection application modes.

[0089] In some embodiments, under the condition that the oil inlet pressure of the pressure reducing valve 1410 is not less than the oil discharge pressure and the oil discharge pressure is within a first preset oil pressure range (for example, it can be set to 3MPa to 5MPa), the brake control valve 144 can connect the oil discharge port of the oil pump assembly 12 with the pressure control port of the speed reducer brake 3, that is, the oil pump assembly 12 is allowed to supply hydraulic oil to the pressure control port of the speed reducer brake 3 at this time.

[0090] However, when the oil inlet pressure of the pressure reducing valve 1410 is lower than the oil discharge pressure and / or the oil discharge pressure is not within the first preset oil pressure range mentioned above, it can be determined that there is an abnormality in the system pressure. At this time, the brake control valve 144 cannot connect the oil discharge port of the oil pump assembly 12 with the pressure control port of the speed reducer brake 3, that is, the oil pump assembly 12 is not allowed to supply hydraulic oil to the pressure control port of the speed reducer brake 3 at this time, thereby ensuring system safety.

[0091] In some embodiments, the tractor hydraulic system may further include a second pressure sensor 16 capable of detecting the drain oil pressure of the pressure reducing valve 1410 and a third pressure sensor 17 capable of detecting the oil pressure of the pressure control port of the speed reducer brake 3 .

[0092] Under the working condition that the discharge oil pressure of the pressure reducing valve 1410 is equal to the oil pressure of the pressure control port of the speed reducer brake 3 and the discharge oil pressure of the pressure reducing valve 1410 is within the second preset oil pressure range (this range can be set to be equal to the aforementioned first preset oil pressure range, for example, it can be set to 3MPa to 5MPa), it means that the brake control valve 144 is not blocked or has not been switched to the on state, so the speed reducer brake 3 can be started at this time.

[0093] However, when the discharge oil pressure of the pressure reducing valve 1410 is not equal to the oil pressure of the pressure control port of the speed reducer brake 3 and / or the discharge oil pressure of the pressure reducing valve 1410 is not within the above-mentioned second preset oil pressure range, it can be determined that there is an abnormality in the system pressure, and the brake control valve 144 may be blocked or not switched to the on state. At this time, the speed reducer brake 3 is not allowed to start, thereby ensuring system safety.

[0094] In some embodiments, under the premise that the traction machine hydraulic system is provided with a third pressure sensor 17, and under the condition that the motor 13 needs to be started and the oil pressure at the pressure control port of the speed reducer brake 3 is not greater than the preset maximum starting oil pressure (for example, it can be set to zero), it means that the speed reducer brake 3 has completed unloading, and the motor 13 can be started at this time, thereby avoiding its load starting.

[0095] When the motor 13 needs to be started and the oil pressure at the pressure control port of the speed reducer brake 3 is greater than the above-mentioned preset maximum starting oil pressure, it means that the speed reducer brake 3 has not been completely unloaded. At this time, the motor 13 cannot be started and the speed reducer brake 3 needs to be unloaded first.

[0096] For the multiple system pressure detection embodiments listed above, when the system pressure is determined to be abnormal, an alarm signal can be sent out by setting an alarm and / or fault information can be displayed through a display device to remind the user to check the system abnormality and fault.

[0097] In addition, the first pressure sensor 15, the second pressure sensor 16, the third pressure sensor 17, the alarm and the display device can all communicate with the controller in the traction machine, so that the controller can automatically determine whether there is an abnormality in the system pressure, and automatically control the alarm to send an alarm signal in a timely manner, thereby realizing intelligent control of the traction machine hydraulic system.

[0098] In some embodiments, the tractor hydraulic system of the present application may also include an auxiliary oil supply circuit 1412 branching from the main oil supply circuit 141 and an auxiliary oil return circuit 1413 branching from the main oil return circuit 142. The auxiliary oil supply circuit 1412 and the auxiliary oil return circuit 1413 can be used to connect to other external hydraulic actuators, thereby expanding the function of the tractor.

[0099] In some embodiments, the tractor hydraulic system of the present application is integrated into an independently transportable hydraulic pump station 1, in which a control valve group 14 is provided, and the control valve group 14 can integrate multiple valves in the tractor hydraulic system.

[0100] In addition, a second exemplary embodiment of the present application further provides a tractor, which includes the above-mentioned tractor hydraulic system.

[0101] In some embodiments, the traction machine may further include a reducer, a reducer brake 3 and different hydraulic actuators such as a tail rope frame motor 4, a tilting cylinder 5, a wire pressing cylinder 6, and a leg cylinder 7.

[0102] In some embodiments, the traction machine may further include a multi-way valve 2. At this time, hydraulic actuators such as the tail rope rack motor 4, the tilting cylinder 5, the wire pressing cylinder 6 and the outrigger cylinder 7 can be connected to the main oil supply circuit 141 and the main oil return circuit 142 through the multi-way valve 2, so that the tail rope rack motor 4, the tilting cylinder 5, the wire pressing cylinder 6 and the outrigger cylinder 7 can be controlled to start and stop respectively through multiple control valves in the multi-way valve 2.

[0103] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0104] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0105] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0106] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. Tractor hydraulic system, characterized in that: include: Fuel tank (11); A motor pump, comprising an oil pump assembly (12) and a motor (13) driving the oil pump assembly (12), wherein an oil inlet of the oil pump assembly (12) is connected to the oil tank (11); A main oil supply circuit (141) connected to the oil discharge port of the oil pump assembly (12) and capable of supplying oil to the hydraulic actuator; A main oil return line (142) capable of connecting the oil tank (11) and the hydraulic actuator; and The brake control valve (144) is used to connect the pressure control port of the speed reducer brake (3) with the oil discharge port of the oil pump assembly (12) and the oil tank (11), and can control the opening and closing of the speed reducer brake (3).

2. The tractor hydraulic system according to claim 1, characterized in that: The oil pump assembly (12) comprises a large-displacement oil pump (121) and a small-displacement oil pump (122) having a smaller displacement than the large-displacement oil pump (121); the oil discharge port of the large-displacement oil pump (121) and the oil discharge port of the small-displacement oil pump (122) are both connected to the main oil supply circuit (141) and the brake control valve (144); the tractor hydraulic system further comprises a first unloading control valve (145); the oil discharge port of the large-displacement oil pump (121) is connected to the main oil return circuit (142) via the first unloading control valve (145).

3. The tractor hydraulic system according to claim 2, characterized in that: The tractor hydraulic system further comprises a second unloading control valve (146), and the oil discharge port of the small displacement oil pump (122) is connected to the main oil return line (142) via the second unloading control valve (146).

4. The tractor hydraulic system according to claim 3, characterized in that: When the motor (13) starts to start, the first unloading control valve (145) can conduct the oil discharge port of the large-displacement oil pump (121) and the main oil return line (142), and the second unloading control valve (146) can conduct the oil discharge port of the small-displacement oil pump (122) and the main oil return line (142).

5. The tractor hydraulic system according to claim 2, characterized in that: The tractor hydraulic system further comprises a first pressure sensor (15) capable of detecting the confluence pressure between the main oil supply circuit (141) and the oil discharge port of the large displacement oil pump (121) and the oil discharge port of the small displacement oil pump (122); Under the operating condition where the confluence pressure is greater than the preset maximum confluence pressure, the first unloading control valve (145) can conduct the oil discharge port of the large-displacement oil pump (121) and the main oil return line (142).

6. The tractor hydraulic system according to claim 2, characterized in that: The tractor hydraulic system further comprises a first one-way valve (147) and a second one-way valve (148); the oil discharge port of the large-displacement oil pump (121) is connected to the brake control valve (144) via the first one-way valve (147); and the oil discharge port of the small-displacement oil pump (122) is connected to the brake control valve (144) via the second one-way valve (148).

7. The tractor hydraulic system according to claim 1, characterized in that: The oil pump assembly (12) comprises a load-sensitive variable displacement pump (123), the main oil supply circuit (141) and the brake control valve (144) are both connected to the oil discharge port of the load-sensitive variable displacement pump (123), and the traction machine hydraulic system further comprises a load feedback circuit (143), and the load feedback circuit (143) is used to connect the load control port of the load-sensitive variable displacement pump (123) and the hydraulic actuator.

8. The tractor hydraulic system according to claim 7, characterized in that: The traction machine hydraulic system further comprises a load feedback relief valve (149) connecting the main oil return circuit (142) and the load feedback circuit (143).

9. The tractor hydraulic system according to claim 1, characterized in that: The tractor hydraulic system further comprises a pressure reducing valve (1410) with adjustable oil discharge pressure, wherein the oil inlet of the pressure reducing valve (1410) is connected to the oil discharge port of the oil pump assembly (12), the oil discharge port of the pressure reducing valve (1410) is connected to the pressure control port of the speed reducer brake (3) via the brake control valve (144), and the pressure relief port of the pressure reducing valve (1410) is connected to the oil tank (11).

10. The tractor hydraulic system according to claim 9, characterized in that: The tractor hydraulic system further comprises a first pressure sensor (15) capable of detecting the oil inlet pressure of the pressure reducing valve (1410) and a second pressure sensor (16) capable of detecting the oil outlet pressure of the pressure reducing valve (1410).

11. The tractor hydraulic system according to claim 10, characterized in that: Under the operating condition that the oil inlet pressure of the pressure reducing valve (1410) is not less than the oil discharge pressure and the oil discharge pressure is within a first preset oil pressure range, the brake control valve (144) is capable of conducting the oil discharge port of the oil pump assembly (12) and the pressure control port of the speed reducer brake (3); Under the operating condition that the oil inlet pressure of the pressure reducing valve (1410) is lower than the oil discharge pressure and / or the oil discharge pressure is not within the first preset oil pressure range, the brake control valve (144) cannot connect the oil discharge port of the oil pump assembly (12) with the pressure control port of the speed reducer brake (3).

12. The tractor hydraulic system according to claim 9, characterized in that: The traction machine hydraulic system further comprises a second pressure sensor (16) capable of detecting the discharge oil pressure of the pressure reducing valve (1410) and a third pressure sensor (17) capable of detecting the oil pressure of the pressure control port of the speed reducer brake (3); Under the operating condition that the discharge oil pressure of the pressure reducing valve (1410) is equal to the oil pressure of the pressure control port of the speed reducer brake (3) and the discharge oil pressure of the pressure reducing valve (1410) is within the second preset oil pressure range, the speed reducer brake (3) can be started; Under the condition that the discharge oil pressure of the pressure reducing valve (1410) is not equal to the oil pressure at the pressure control port of the speed reducer brake (3) and / or the discharge oil pressure of the pressure reducing valve (1410) is not within the second preset oil pressure range, the speed reducer brake (3) cannot be started.

13. The tractor hydraulic system according to claim 1, characterized in that: The traction machine hydraulic system further comprises a third pressure sensor (17) for detecting the oil pressure of the pressure control port of the reduction machine brake (3).

14. The tractor hydraulic system according to claim 13, characterized in that: Under the operating condition that the motor (13) needs to be started and the oil pressure at the pressure control port of the speed reducer brake (3) is not greater than the preset maximum starting oil pressure, the motor (13) can be started; under the operating condition that the motor (13) needs to be started and the oil pressure at the pressure control port of the speed reducer brake (3) is greater than the preset maximum starting oil pressure, the motor (13) cannot be started.

15. A traction machine, characterized in that: The invention comprises a tractor hydraulic system according to any one of claims 1 to 14.

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