Hydraulic system for a tractor and tractor

Abstract

The application relates to the field of line traction construction equipment, and discloses a traction machine hydraulic system and a traction machine. The traction machine hydraulic system comprises an oil tank, a motor pump, a main oil supply oil path, a main oil return oil path and a brake control valve. 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 oil path is connected with an oil outlet of the oil pump assembly and can supply oil to a hydraulic actuator. The main oil return oil path can connect the oil tank with the hydraulic actuator. The brake control valve is used for connecting a pressure control port of a speed reducer brake, the oil outlet of the oil pump assembly and the oil tank, and can control the opening and closing of the speed reducer brake. The traction machine hydraulic system can solve the problems of large pollution and large noise of the existing traction machine, and can improve transmission efficiency and reduce energy consumption.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of line traction construction equipment, and particularly relates to a traction machine hydraulic system and a traction machine. BACKGROUND

[0002] The traction machine can be used for line traction construction of power grid overhead lines and the like, and provides power for a hydraulic pump station through a gasoline engine or a diesel engine, and then provides hydraulic power for driving various hydraulic actuators to act, so as to realize different functions.

[0003] However, the existing traction machine provides source power through a gasoline engine or a diesel engine, which is large in pollution and noise and poor in environmental friendliness; in addition, the hydraulic pump is driven by the gasoline engine or the diesel engine, and then the hydraulic actuator is driven by the hydraulic pump, which is low in transmission efficiency and large in energy consumption. SUMMARY

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

[0005] In order to achieve the above-mentioned purpose, the application provides a traction machine hydraulic system in one aspect, which comprises:

[0006] an oil tank;

[0007] a motor pump comprising an oil pump assembly and a motor for driving the oil pump assembly, and an oil inlet of the oil pump assembly being connected with the oil tank;

[0008] a main oil supply oil path connected with an oil outlet of the oil pump assembly and capable of supplying oil to a hydraulic actuator;

[0009] a main oil return oil path capable of connecting the oil tank with the hydraulic actuator; and

[0010] a brake control valve for connecting a pressure control port of a speed reducer brake with the oil outlet of the oil pump assembly and the oil tank, and capable of controlling the opening and closing of the speed reducer brake.

[0011] In some embodiments, the oil pump assembly comprises 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 outlet of the large-displacement oil pump and the oil outlet of the small-displacement oil pump are both connected with the main oil supply oil path and the brake control valve, and the traction machine hydraulic system further comprises a first unloading control valve, and the oil outlet of the large-displacement oil pump is connected with the main oil return oil path through the first unloading control valve.

[0012] In some embodiments, the traction machine hydraulic system further comprises a second unloading control valve, and the oil outlet of the small-displacement oil pump is connected with the main oil return oil path through the second unloading control valve.

[0013] In some embodiments, the first unloading control valve is capable of conducting the oil discharge port of the large displacement oil pump and the main oil return passage when the motor starts to start, and the second unloading control valve is capable of conducting the oil discharge port of the small displacement oil pump and the main oil return passage.

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

[0015] In some embodiments, the first unloading control valve is capable of conducting the oil discharge port of the large displacement oil pump and the main oil return passage when the confluence pressure is greater than the preset maximum confluence pressure.

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

[0017] In some embodiments, the oil pump assembly comprises a load-sensitive variable pump, the main oil supply passage and the brake control valve are connected to the oil discharge port of the load-sensitive variable pump, and the tractor hydraulic system further comprises a load feedback passage for connecting the load control port of the load-sensitive variable pump and the hydraulic actuator.

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

[0019] In some embodiments, the tractor hydraulic system further comprises a pressure-adjustable pressure reducing valve, 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 speed reducer 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 comprises a first pressure sensor capable of detecting the oil inlet pressure of the pressure reducing valve and a second pressure sensor capable of detecting the oil discharge pressure of the pressure reducing valve.

[0021] In some embodiments, the brake control valve is capable of conducting the oil discharge port of the oil pump assembly and the pressure control port of the speed reducer brake when the oil inlet pressure of the pressure reducing valve is not less than the oil discharge pressure and the oil discharge pressure is within a first preset oil pressure range.

[0022] In a working condition where the oil inlet pressure of the pressure reducing valve is less than the oil outlet pressure and / or the oil outlet pressure is not in the first preset oil pressure range, the brake control valve cannot connect the oil outlet of the oil pump assembly to the pressure control port of the speed reducer brake.

[0023] In some embodiments, the traction machine hydraulic system further comprises a second pressure sensor capable of detecting the oil outlet 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] In a working condition where the oil outlet pressure of the pressure reducing valve is equal to the oil pressure of the pressure control port of the speed reducer brake and the oil outlet pressure of the pressure reducing valve is in the second preset oil pressure range, the speed reducer brake can be started.

[0025] In a working condition where the oil outlet 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 oil outlet pressure of the pressure reducing valve is not in the second preset oil pressure range, the speed reducer brake cannot be started.

[0026] In some embodiments, the traction machine hydraulic system further comprises a third pressure sensor for detecting the oil pressure of the pressure control port of the speed reducer brake.

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

[0028] The second aspect of the present application also provides a traction machine comprising the traction machine hydraulic system described above.

[0029] Through the above technical solution, the traction machine hydraulic system of the present application uses the motor as a power source. The motor can drive the oil pump assembly to operate, so that the oil pump assembly generates a pumping action to suck the hydraulic oil in the oil tank into its oil inlet port. The oil pump assembly can supply the hydraulic oil to the speed reducer brake through the brake control valve through its oil outlet port, and can also supply the hydraulic oil to the hydraulic actuator through the main oil supply oil path, thereby opening the speed reducer brake or driving the hydraulic actuator. It can be seen that the traction machine hydraulic system of the present application has no pollution emission and low noise when in use, is clean and environmentally friendly, and has high transmission efficiency and reduced energy consumption compared with using a fuel power source.

[0030] Other features and advantages of the embodiments of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0031] The accompanying drawings are included to provide a further understanding of embodiments of the application, and are incorporated in and constitute a part of this specification, illustrate embodiments of the application, and together with the description serve to explain embodiments of the application. Other embodiments of the application can be obtained from a review of the drawings, either from the description of the figures or by practicing the application. In the drawings:

[0032] Figure 1 is a schematic view of a hydraulic system, a multi-way valve, a retarder, and a plurality of hydraulic actuators according to an embodiment of the application;

[0033] Figure 2 is a schematic view of a hydraulic system, a multi-way valve, a retarder, and a plurality of hydraulic actuators according to another embodiment of the application.

[0034] BRIEF DESCRIPTION OF DRAWINGS

[0035] 1 hydraulic pump station 2 multi-way valve

[0036] 3 retarder 4 tail rope frame motor

[0037] 5 turnover cylinder 6 line pressing cylinder

[0038] 7 outrigger cylinder

[0039] 11 oil tank 12 oil 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 oil passage

[0045] 142 main oil return oil passage 143 load feedback oil passage

[0046] 144 retarder 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 secondary oil supply oil passage 1413 secondary oil return oil passage DETAILED DESCRIPTION

[0051] The specific embodiments of the present application will be described in detail hereinafter with reference to the drawings. It should be understood that the specific embodiments described herein are merely illustrative and explanatory and are not intended to limit the present application.

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

[0053] Specifically, the motor pump comprises an oil pump assembly 12 and a motor 13 for driving the oil pump assembly 12, the oil pump assembly 12 has an oil inlet connected to the oil tank 11, and 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 oil passage 141 is connected to an oil outlet of the oil pump assembly 12, and the oil pump assembly 12 can pump the hydraulic oil through its oil outlet to the main oil supply oil passage 141, and then the main oil supply oil passage 141 can supply the hydraulic oil to the hydraulic actuators (for example, the tail rope frame motor 4, the overturning cylinder 5, the line pressing cylinder 6 and the leg cylinder 7 of the tractor, etc.) in the tractor to drive the hydraulic actuators to act. The main oil return oil passage 142 can connect the oil tank 11 and the hydraulic actuators, and when the hydraulic actuators act, the hydraulic oil discharged by the hydraulic actuators can flow back to the oil tank 11 through the main oil return oil passage 142.

[0055] Generally, the above-mentioned tail rope frame motor 4, overturning cylinder 5, line pressing cylinder 6 and leg cylinder 7 do not work at the same time, and can be independently started and stopped. The tail rope frame motor 4 is used to drive the tail rope frame in the tractor to rotate to wind or unwind the line wound on the tail rope frame, the overturning cylinder 5 is used to drive the tail rope frame as a whole to overturn up and down to adjust the ground clearance of the tail rope frame, the line pressing cylinder 6 is used to press the line, and the leg cylinder 7 is used to realize the leveling of the tractor.

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

[0057] As an example, the brake control valve 144 can be a two-position four-way electromagnetic reversing valve. When the two-position four-way electromagnetic reversing valve is powered on, it can connect the oil discharge port of the oil pump assembly 12 to the pressure control port of the retarder brake 3. At this time, the two-position four-way electromagnetic reversing valve controls the retarder brake 3 to open. When the two-position four-way electromagnetic reversing valve is powered off, it can connect the pressure control port of the retarder brake 3 to the oil tank 11, and at this time the oil discharge port of the oil pump assembly 12 is not connected to the pressure control port of the retarder brake 3. Thus, the pressure control port of the retarder brake 3 is depressurized, the retarder brake 3 is closed, and the retarder can stop running. Of course, the brake control valve 144 can also use other types of valves, which are not limited in the present application.

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

[0059] In some embodiments, referring to Figure 1 , the oil pump assembly 12 can include a large displacement oil pump 121 and a small displacement oil pump 122 with a smaller displacement than the large displacement oil pump 121. At this time, 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. The main oil supply oil line 141 and the brake control valve 144 are connected to the oil discharge port of the large displacement oil pump 121, and the main oil supply oil line 141 and the brake control valve 144 are 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 be first merged and then flow to the main oil supply oil line 141 and the brake control valve 144.

[0060] In addition, the traction machine hydraulic system can further comprise a first unloading control valve 145, and the oil outlet of the large displacement oil pump 121 is connected to the main oil return oil path 142 through the first unloading control valve 145, so that the first unloading control valve 145 can conduct or cut off the connection between the oil outlet of the large displacement oil pump 121 and the main oil return oil path 142.

[0061] When the retarder brake 3 needs to be opened, the first unloading control valve 145 needs to cut off the connection between the oil outlet of the large displacement oil pump 121 and the main oil return oil path 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, thereby enabling the brake control valve 144 to supply the merged hydraulic oil to the pressure control port of the retarder brake 3 to control the opening of the retarder brake 3.

[0062] Since the traction machine generally requires fast line winding and unwinding speed but low load during the line winding and unwinding process, the tail rope frame motor 4 generally operates in a large-flow low-pressure working condition, while the turnover cylinder 5, the line pressing cylinder 6 and the outrigger cylinder 7 have large load but low speed requirement, and thus generally operate in a small-flow high-pressure working condition.

[0063] It can be seen that the tail rope frame motor 4 needs to operate in a large-flow low-pressure working condition, so when the tail rope frame motor 4 operates, the first unloading control valve 145 needs to cut off the connection between the oil outlet of the large displacement oil pump 121 and the main oil return oil path 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, thereby enabling the main oil supply oil path 141 to supply the large-flow low-pressure hydraulic oil to the tail rope frame motor 4.

[0064] The turnover cylinder 5, the line pressing cylinder 6 and the outrigger cylinder 7 need to operate in a small-flow high-pressure working condition, so when any one of the turnover cylinder 5, the line pressing cylinder 6 and the outrigger cylinder 7 operates, the first unloading control valve 145 needs to conduct the connection between the oil outlet of the large displacement oil pump 121 and the main oil return oil path 142, so that the hydraulic oil discharged by the large displacement oil pump 121 can be directly returned to the oil tank 11 through the main oil return oil path 142, and at this time, the hydraulic oil of the main oil supply oil path 141 only comes from the small displacement oil pump 122, so the main oil supply oil path 141 can supply the small-flow high-pressure hydraulic oil to any one of the turnover cylinder 5, the line pressing cylinder 6 and the outrigger cylinder 7.

[0065] It should be noted that, since the flow rate and pressure of the hydraulic oil flowing through the brake control valve 144 and the main oil supply oil path 141 can be controlled by switching the on-off state of the first unloading control valve 145, both the large-displacement oil pump 121 and the small-displacement oil pump 122 can be a fixed-displacement pump, such as a fixed-displacement gear pump, but the present application does not limit the large-displacement oil pump 121 and the small-displacement oil pump 122 to be a variable-displacement pump. Moreover, the present application also does not limit the number of the motor 13, for example, when only one motor 13 is provided, the large-displacement oil pump 121 and the small-displacement oil pump 122 can be driven by the motor 13 in series; when two motors 13 are provided, the large-displacement oil pump 121 and the small-displacement oil pump 122 can be independently driven 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, when powered, conducts the drain port of the large-displacement oil pump 121 and the main oil return oil path 142, and when de-energized, cuts off the drain port of the large-displacement oil pump 121 and the main oil return oil path 142. Of course, the present application also does not limit the first unloading control valve 145 to be other types of valves.

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

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

[0069] When it is necessary to open the speed reducer brake 3, not only does the first unloading control valve 145 need to cut off the drain port of the large-displacement oil pump 121 and the main oil return oil path 142, but the second unloading control valve 146 also needs to cut off the drain port of the small-displacement oil pump 122 and the main oil return oil path 142.

[0070] In addition, the tail rope frame motor 4 needs to work in a large flow and low pressure condition, so when the tail rope frame motor 4 is running, not only does the first unloading control valve 145 need to cut off the oil outlet 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 outlet of the small displacement oil pump 122 and the main oil return oil circuit 142.

[0071] The turnover oil cylinder 5, the line pressing oil cylinder 6, and the outrigger oil cylinder 7 need to work in a small flow and high pressure condition, so when any one of the turnover oil cylinder 5, the line pressing oil cylinder 6, and the outrigger oil cylinder 7 is running, the first unloading control valve 145 needs to conduct the oil outlet of the large displacement oil pump 121 and the main oil return oil circuit 142, but the second unloading control valve 146 needs to cut off the oil outlet of the small displacement oil pump 122 and the main oil return oil circuit 142.

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

[0073] In some embodiments, in the working condition when the motor 13 starts to start, the first unloading control valve 145 can conduct the oil outlet of the large displacement oil pump 121 and the main oil return oil circuit 142, and the second unloading control valve 146 can conduct the oil outlet of the small displacement oil pump 122 and the main oil return oil circuit 142, so that when the motor 13 starts to start, the entire traction machine hydraulic system is unloaded, avoiding the load start of the motor 13, which is beneficial to speed up the acceleration speed of the motor 13 and plays a role in protecting the motor 13.

[0074] In some embodiments, the traction machine hydraulic system can further include a first pressure sensor 15 capable of detecting the confluence pressure between the main oil supply oil circuit 141 and the oil outlet of the large displacement oil pump 121 and the oil outlet of the small displacement oil pump 122. When the first pressure sensor 15 detects that the confluence pressure is greater than a preset maximum confluence pressure, the first unloading control valve 145 can conduct the oil outlet of the large displacement oil pump 121 and the main oil return oil 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 frame motor 4 needs to work in a large flow and low pressure condition, according to the formula P = Qv*Ap / 600 / η (wherein P is power (kW), Qv is flow (L / min), Ap is pressure (bar), and η is efficiency), when the power is constant, if the flow is larger, the pressure is smaller. When the traction machine drives the tail rope frame through the tail rope frame motor 4 to carry out the line winding and unwinding at a normal maximum speed, the flow required by the tail rope frame motor 4 is the largest at this time, and the large displacement oil pump 121 and the small displacement oil pump 122 both need to supply oil to the main oil supply oil way 141, but if the load of the line changes greatly at this time, and the above-mentioned junction pressure detected by the first pressure sensor 15 is greater than the preset maximum junction pressure, the first unloading control valve 145 can be turned on to connect the oil discharge port of the large displacement oil pump 121 and the main oil return oil way 142, so that the large displacement oil pump 121 is unloaded, thereby avoiding the overload of the motor 13 and affecting the line winding and unwinding 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 whole traction machine hydraulic system is reduced due to the unloading of the large displacement oil pump 121, according to the above-mentioned 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 can further comprise a first one-way valve 147 and a second one-way valve 148, at this time, 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 does not have enough oil pressure to turn on the first one-way valve 147 to flow to the brake control valve 144, and when the first unloading control valve 145 is disconnected, the first one-way valve 147 can avoid that the oil pressure of the hydraulic oil flowing from the large displacement oil pump 121 to the brake control valve 144 is too low.

[0078] Similarly, by setting 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 does not have enough oil pressure to turn on the second one-way valve 148 to flow to the brake control valve 144, and when the second unloading control valve 146 is disconnected, the second one-way valve 148 can avoid that the oil pressure of the hydraulic oil flowing from the small displacement oil pump 122 to the brake control valve 144 is too low.

[0079] In some embodiments, referring to Figure 2, the oil pump assembly 12 can include a load-sensing variable pump 123, and the oil discharge port of the oil pump assembly 12 includes the oil discharge port of the load-sensing variable pump 123, and the main oil supply oil passage 141 and the brake control valve 144 are connected to the oil discharge port of the load-sensing variable pump 123, so that the load-sensing variable pump 123 can supply oil to the main oil supply oil passage 141 and the brake control valve 144, and because the load-sensing variable pump 123 can adjust the displacement, the load-sensing variable pump 123 can match different flow and pressure requirements of different hydraulic actuators. At the same time, the settings of 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 of the load-sensing variable pump 123, the traction machine hydraulic system further comprises a load feedback oil passage 143 for connecting the load control port of the load-sensing variable pump 123 and the hydraulic actuators. For example, when any one of the tail rope frame motor 4, the overturning cylinder 5, the wire pressing cylinder 6, and the outrigger cylinder 7 is working, if the working pressure of the working changes, the working pressure can be fed back to the load control port of the load-sensing variable pump 123 through the load feedback oil passage 143, and the load-sensing variable pump 123 can adjust the pump displacement according to the change of the working pressure to match the flow and pressure requirements in different specific working conditions.

[0081] Through the setting of the embodiment, because the displacement of the load-sensing variable pump 123 is adjustable, the different flow and pressure requirements of the traction machine reducer brake 3 and different hydraulic actuators for hydraulic oil can be met. Therefore, in the embodiment, the motor 13 can also be a small-power motor with constant power (of course, a large-power motor is not excluded in the present application), so that the volume of the motor 13 is smaller, the overall occupied space of the traction machine hydraulic system can be reduced, and the production manufacturing cost can be reduced. When the traction machine hydraulic system of the present application is integrated into a hydraulic pump station that can be independently transported, the transportation cost and difficulty of the hydraulic pump station can be reduced; when the traction machine hydraulic system of the present application is installed and fixed on the traction machine, the overall transportation cost and difficulty of the traction machine can be reduced.

[0082] In some embodiments, the traction machine hydraulic system can further comprise a load feedback overflow valve 149 connected between the main oil return oil passage 142 and the load feedback oil passage 143, which can limit the maximum working pressure of the load feedback oil passage 143 to realize safety protection of the load-sensing variable pump 123.

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

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

[0085] In some embodiments, the tractor hydraulic system can further include a supply overflow valve 1411 connected between the main oil supply circuit 141 and the main oil return circuit 142, which can prevent the main oil supply circuit 141 from overpressure, thereby improving system safety.

[0086] In some embodiments, the tractor hydraulic system can further include a pressure reducing valve 1410 with adjustable discharge pressure, the inlet of the pressure reducing valve 1410 being connected to the oil discharge port of the oil pump assembly 12, the outlet of the pressure reducing valve 1410 being connected to the pressure control port of the speed reducer brake 3 through the brake control valve 144, and the relief port of the pressure reducing valve 1410 being 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 first pass through the pressure reducing valve 1410 to reduce the pressure and then flow into the pressure control port of the speed reducer brake 3 through the brake control valve 144. The 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 discharge pressure of the pressure reducing valve 1410 can be set within 3MPa to 10MPa (such as 5MPa).

[0087] It should be noted that during the operation of the tractor, the normal operation of the speed reducer brake 3 is the primary prerequisite for the safe operation of the entire machine, and therefore to ensure the normal opening and closing of the speed reducer brake 3, the pressure of different positions of the tractor hydraulic system can be monitored through the following embodiments, as follows:

[0088] In some embodiments, the tractor hydraulic system can further comprise 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 outlet oil pressure of the pressure reducing valve 1410, so as to monitor the inlet oil pressure and the outlet oil pressure of the pressure reducing valve 1410 to avoid the situation that the abnormal pressure of the oil circuit where the brake control valve 144 is located is not detected. In addition, as can be known from the foregoing, the first pressure sensor 15 can be used to detect not only the confluence pressure between the main oil supply circuit 141 and the outlet of the large displacement oil pump 121 and the outlet of the small displacement oil pump 122, but also the inlet oil pressure of the pressure reducing valve 1410, thus having multiple detection application modes.

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

[0090] Under the working condition that the inlet oil pressure of the pressure reducing valve 1410 is less than the outlet oil pressure and / or the outlet oil pressure is not within the first preset oil pressure range, it can be judged that the system pressure is abnormal, at this time, the brake control valve 144 cannot conduct the outlet of the oil pump assembly 12 to the pressure control port of the reduction brake 3, that is, at this time, the oil pump assembly 12 is not allowed to supply hydraulic oil to the pressure control port of the reduction brake 3, so as to ensure the safety of the system.

[0091] In some embodiments, the tractor hydraulic system can further comprise a second pressure sensor 16 capable of detecting the outlet 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 reduction brake 3.

[0092] Under the working condition that the outlet oil pressure of the pressure reducing valve 1410 is equal to the oil pressure of the pressure control port of the reduction brake 3 and the outlet oil pressure of the pressure reducing valve 1410 is within a second preset oil pressure range (which can be set to be equal to the first preset oil pressure range described above, for example, which can be set to 3-5 MPa), it means that the brake control valve 144 does not have the phenomenon of blockage or not switching to the conducting state, so at this time, the reduction brake 3 can be started.

[0093] Under the working condition that the outlet oil pressure of the pressure reducing valve 1410 is not equal to the oil pressure of the pressure control port of the reduction brake 3 and / or the outlet oil pressure of the pressure reducing valve 1410 is not within the second preset oil pressure range, it can be judged that the system pressure is abnormal, the brake control valve 144 can have the phenomenon of blockage or not switching to the conducting state, at this time, the reduction brake 3 is not allowed to start, so as to ensure the safety of the system.

[0094] In some embodiments, in the case that the third pressure sensor 17 is provided in the traction machine hydraulic system, and in the case that the motor 13 needs to be started and the oil pressure of the pressure control port of the retarder brake 3 is not greater than the preset maximum starting oil pressure (for example, which can be set to zero), it means that the retarder brake 3 has completed unloading, and at this time the motor 13 can be started, so that the load starting of the motor 13 can be avoided.

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

[0096] For the above-mentioned multiple system pressure detection embodiments, when it is judged that the system pressure is abnormal, an alarm signal can be sent by setting an alarm and / or fault information can be displayed by a display device, so as 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 judge whether the system pressure is abnormal, and automatically control the alarm to send an alarm signal in time, so as to realize intelligent control of the traction machine hydraulic system.

[0098] In some embodiments, the traction machine hydraulic system of the present application can further include a secondary oil supply oil path 1412 branched from the main oil supply oil path 141 and a secondary oil return oil path 1413 branched from the main oil return oil path 142, and the secondary oil supply oil path 1412 and the secondary oil return oil path 1413 can be used to connect other hydraulic actuators, so that the function of the traction machine can be expanded.

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

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

[0101] In some embodiments, the traction machine can further include a retarder, a retarder brake 3, and different hydraulic actuators such as a tail rope rack motor 4, a turnover cylinder 5, a wire pressing cylinder 6, a support leg cylinder 7, etc.

[0102] In some embodiments, the traction machine can further comprise a multi-way valve 2, and the hydraulic actuators such as the tail rope frame motor 4, the overturning cylinder 5, the line pressing cylinder 6 and the outrigger cylinder 7 can be connected to the main oil supply oil way 141 and the main oil return oil way 142 through the multi-way valve 2, so that the hydraulic actuators such as the tail rope frame motor 4, the overturning cylinder 5, the line pressing cylinder 6 and the outrigger cylinder 7 can be controlled to start and stop through the control valves in the multi-way valve 2.

[0103] In the description of the present application, it should be understood that the terms "first", "second" are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can be explicitly or implicitly included at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0104] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connecting", "fixing" and other terms should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or communicate with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0105] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the present application 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 limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to 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 the 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 A 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 is capable of controlling the opening and closing of the speed reducer brake (3); The oil pump assembly (12) includes 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 includes 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).

2. The tractor hydraulic system according to claim 1, 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).

3. The tractor hydraulic system according to claim 2, 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 oil circuit (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 oil circuit (142).

4. The tractor hydraulic system according to claim 1, characterized in that: The tractor hydraulic system further comprises a first pressure sensor (15) capable of detecting the combined 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 connect the oil discharge port of the large-displacement oil pump (121) and the main oil return line (142).

5. The tractor hydraulic system according to claim 1, 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).

6. The tractor hydraulic system according to claim 1, characterized in that: The oil pump assembly (12) includes 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 includes 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.

7. The tractor hydraulic system according to claim 6, characterized in that: The tractor hydraulic system further includes a load feedback overflow valve (149) connecting the main oil return circuit (142) and the load feedback circuit (143).

8. 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).

9. The tractor hydraulic system according to claim 8, characterized in that: The tractor hydraulic system further includes 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).

10. The tractor hydraulic system according to claim 9, 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) and the pressure control port of the speed reducer brake (3).

11. The tractor hydraulic system according to claim 8, characterized in that: The traction machine hydraulic system further includes 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 operating conditions that 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 second preset oil pressure range, the speed reducer brake (3) cannot be started.

12. 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 speed reducer brake (3).

13. The tractor hydraulic system according to claim 12, 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.

14. Tractor, characterized in that: The invention comprises a tractor hydraulic system according to any one of claims 1 to 13.

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