Grader hydraulic control system, grader hydraulic control method, and grader

Abstract

The present application provides a grader hydraulic control system, a grader hydraulic control method, and a grader. The grader comprises an oscillating frame assembly and a first working device, and a plurality of lock pin holes are formed in the oscillating frame assembly. The grader hydraulic control system comprises: a cylinder assembly, connected to the oscillating frame assembly and the first working device, wherein the cylinder assembly comprises a plurality of first working cylinders; a lock pin assembly, wherein the lock pin assembly comprises a driving member and a lock pin which are connected to each other, and the lock pin is configured to be capable of being inserted into or moved out of any one of the plurality of lock pin holes under the driving of the driving member; and a control valve group, connected to at least one of the plurality of first working cylinders, wherein when the control valve group enables the oil pressure of a first oil chamber and the oil pressure of a second oil chamber of the at least one first working cylinder to be smaller than or equal to a preset value, the driving member drives the lock pin to move out of the lock pin hole.

Description

Hydraulic control system of motor grader, hydraulic control method of motor grader and motor grader

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on October 26, 2023, with application number "202311404299.2" and application name "Hydraulic control system of grader, hydraulic control method of grader and grader", the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of motor graders, and in particular to a hydraulic control system of a motor grader, a hydraulic control method of a motor grader, and a motor grader. Background Art

[0003] Currently, motor graders, as earth-moving and transporting machines, can adapt their working mechanisms to various applications, such as earthwork leveling, ditch excavation, and slope adjustment, simply by changing the locking pin hole position. In related technologies, the locking pin insertion and removal methods for motor grader swing frames primarily include manual and hydraulic insertion and removal, with hydraulic insertion and removal being the most widely used due to its convenience.

[0004] However, when hydraulically controlled plugging and unplugging are performed, the left and right lifting and swing cylinders are in a locked state, and the unbalanced pressure of each cylinder applies a large radial load to the locking pin. As the bearings of the operating device and the swing frame mechanism wear, the radial force will further increase, making it difficult to pull out the locking pin and affecting construction.

[0005] Summary of the Invention

[0006] The embodiments of the present application are intended to solve at least one of the technical problems existing in the prior art.

[0007] To this end, a first aspect of an embodiment of the present application provides a hydraulic control system for a motor grader.

[0008] A second aspect of an embodiment of the present application provides a motor grader.

[0009] A third aspect of the embodiments of the present application provides a hydraulic control method for a motor grader.

[0010] In view of this, according to the first aspect of an embodiment of the present application, a hydraulic control system of a grader is provided, the hydraulic control system of the grader is used for the grader, the grader includes a swing frame assembly and a first working device, the swing frame assembly is provided with a plurality of locking pin holes, the hydraulic control system of the grader includes: a cylinder assembly, connected to the swing frame assembly and the first working device, the cylinder assembly includes a plurality of first working cylinders; a locking pin assembly, the locking pin assembly includes a connected driving member and a locking pin, the locking pin is configured to be able to be inserted into or moved out of any one of the plurality of locking pin holes under the drive of the driving member; a control valve group, connected to at least one of the plurality of first working cylinders, when the control valve group makes the oil pressure of the oil chamber of at least one first working cylinder less than or equal to a preset value, the driving member drives the locking pin to move out of the locking pin hole.

[0011] Before removing the locking pin, the hydraulic control system of the motor grader provided in the embodiments of the present application reduces the oil pressure in the oil chamber of at least one first working cylinder, placing the at least one first working cylinder in a floating state. This depressurizes the at least one first working cylinder, thereby reducing the radial force applied to the locking pin and unloading the radial load on the locking pin. At this point, the driving member then drives the locking pin out of the locking pin hole, reducing the difficulty of removing the locking pin, enabling faster removal and improving construction efficiency.

[0012] According to a second aspect of the present application, a motor grader is provided, comprising a hydraulic control system for a motor grader as provided by any of the above technical solutions, thereby providing all the beneficial technical effects of the hydraulic control system for a motor grader, which are not further described herein. Furthermore, the motor grader includes a display screen electrically connected to the control valve assembly.

[0013] According to a third aspect of the present application, a hydraulic control method for a grader is provided, wherein the grader includes a swing frame assembly, a first working device, a cylinder assembly and a locking pin assembly, wherein the cylinder assembly is connected to the swing frame assembly and the first working device, the cylinder assembly includes a plurality of first working cylinders, the swing frame assembly is provided with a plurality of locking pin holes, the locking pin assembly includes a connected driving member and a locking pin, and the locking pin is configured to be able to be inserted into or moved out of any one of the plurality of locking pin holes under the drive of the driving member, and the control method includes: controlling the pressure relief of the oil chamber of at least one first working cylinder so that the oil pressure of the oil chamber of at least one first working cylinder is less than or equal to a preset value; and controlling the driving member to drive the locking pin to move out of the locking pin hole.

[0014] The hydraulic control method for a motor grader provided in an embodiment of the present application relieves pressure in at least one first hydraulic cylinder before extracting the locking pin, placing the at least one first hydraulic cylinder in a floating state. This reduces the radial force applied to the locking pin and unloads the radial load on the locking pin. At this point, the driving member then drives the locking pin out of the locking pin hole, reducing the difficulty of extracting the locking pin, enabling faster extraction and improving construction efficiency.

[0015] Additional aspects and advantages of the present application will be given in the following description, and in part will become obvious from the following description, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0017] FIG1 shows one structural schematic diagram of a hydraulic control system of a motor grader according to an embodiment of the present application;

[0018] FIG2 shows one of the structural schematic diagrams of a display screen according to an embodiment of the present application;

[0019] FIG3 shows a second structural schematic diagram of a hydraulic control system of a motor grader according to an embodiment of the present application;

[0020] FIG4 shows a second structural schematic diagram of a display screen according to an embodiment of the present application;

[0021] FIG5 shows a third structural schematic diagram of a hydraulic control system of a motor grader according to an embodiment of the present application;

[0022] FIG6 shows a third structural schematic diagram of a display screen according to an embodiment of the present application;

[0023] FIG7 shows one of the structural schematic diagrams of a motor grader according to an embodiment of the present application;

[0024] FIG8 shows a second structural schematic diagram of a motor grader according to an embodiment of the present application;

[0025] FIG9 shows a flow chart of a hydraulic control method for a motor grader according to an embodiment of the present application;

[0026] FIG10 shows a second flow chart of a hydraulic control method for a motor grader according to an embodiment of the present application;

[0027] FIG11 shows a third flow chart of a hydraulic control method for a motor grader according to an embodiment of the present application;

[0028] FIG12 shows a fourth flow chart of a hydraulic control method for a motor grader according to an embodiment of the present application.

[0029] The corresponding relationship between the reference numerals and component names in Figures 1 to 8 is as follows:

[0030] 100 Hydraulic control system of the grader, 110 Cylinder assembly, 111 First working cylinder, 112 Second working cylinder, 113 Lifting cylinder, 120 Lock pin assembly, 121 Driving member, 122 Lock pin, 123 Driving cylinder, 130 Control valve group, 131 First control valve, 132 Second control valve, 133 Third control valve, 134 Fourth control valve, 135 Speed ​​regulating valve, 136 Fifth control valve, 137 First valve body, 138 Second valve body, 140 Pump body assembly, 141 First pump body, 142 2 Second pump body, 150 Oil source, 151 Oil outlet, 152 Oil return port, 160 First chamber, 170 Second chamber, 180 Hydraulic lock, 190 Shuttle valve, 210 Second relief valve, 220 Compensation valve, 230 First oil chamber, 240 Second oil chamber, 250 First relief valve, 260 Flow limiting hole, 270 First pipeline, 280 Filter assembly, 290 Detection component, 300 Grader, 310 Display screen, 320 Swing frame assembly, 321 Lock pin hole, 330 First working device, 340 Hydraulic motor. DETAILED DESCRIPTION

[0031] In order to more clearly understand the above-mentioned objects, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features therein can be combined with each other in the absence of conflict.

[0032] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0033] 1 to 12 , a hydraulic control system 100 for a motor grader, a motor grader 300 , and a hydraulic control method for a motor grader according to some embodiments of the present application will be described below.

[0034] In one embodiment of the present application, as shown in Figures 1, 2, 3, 7 and 8, a hydraulic control system 100 for a motor grader is proposed. The hydraulic control system 100 for a motor grader is used for a motor grader 300. The motor grader 300 includes a swing frame assembly 320 and a first working device 330. The swing frame assembly 320 is provided with a plurality of lock pin holes 321. The hydraulic control system 100 for the motor grader includes: an oil cylinder assembly 110 connected to the swing frame assembly 320 and the first working device 330. The oil cylinder assembly 110 includes a plurality of first working devices. Cylinder 111; locking pin assembly 120, the locking pin assembly 120 includes a connected driving member 121 and a locking pin 122, the locking pin 122 is configured to be able to be inserted into or moved out of any locking pin hole 321 among the multiple locking pin holes 321 under the drive of the driving member 121; the control valve group 130, connected to at least one of the multiple first working cylinders 111, when the control valve group 130 makes the oil pressure of the oil chamber of at least one first working cylinder 111 less than or equal to a preset value, the driving member 121 drives the locking pin 122 to move out of the locking pin hole 321.

[0035] The hydraulic control system 100 of the grader provided in the embodiment of the present application includes a cylinder assembly 110, a locking pin assembly 120 and a control valve group 130. Specifically, the grader 300 includes a swing frame assembly 320 and a first working device 330. The cylinder assembly 110 connects the swing frame assembly 320 and the first working device 330. Optionally, the first working device 330 includes a blade.

[0036] A plurality of locking pin holes 321 are provided on the swing frame assembly 320. The locking pin assembly 120 includes a connected locking pin 122 and a driving member 121. Driven by the driving member 121, the locking pin 122 can be inserted into or removed from any locking pin hole 321, so that the first working device 330 can switch between different working postures of the first working device 330 by replacing the locking pin hole 321, and thus can operate under different working conditions such as earthwork leveling, ditch excavation and slope finishing.

[0037] When removing the locking pin 122 from the locking pin hole 321 to replace the locking pin hole 321, the imbalanced pressures within the multiple first working cylinders 111 in the cylinder assembly 110 exert a significant radial load on the locking pin 122. Furthermore, as the equipment ages and the bearings of the first operating device and the swing frame assembly 320 wear, the imbalanced pressures within the cylinders increase during operation, making it difficult to remove the locking pin 122 and affecting construction efficiency.

[0038] The cylinder assembly 110 includes a plurality of first working cylinders 111 . Optionally, the plurality of first working cylinders 111 include a lifting cylinder 113 and a swing cylinder, wherein the lifting cylinder 113 includes a left lifting cylinder and a right lifting cylinder.

[0039] The control valve group 130 is connected to at least one first working cylinder 111, and the control valve group 130 can relieve the pressure in the oil chamber of at least one first working cylinder 111 to reduce the oil pressure in the oil chamber of at least one first working cylinder 111, and when the oil pressure in the oil chamber of at least one first working cylinder 111 is reduced to below a preset value, the locking pin 122 is driven out of the locking pin hole 321 through the driving member 121.

[0040] That is, before extracting the lock pin 122, the oil pressure in the oil chamber of at least one first working oil cylinder 111 is reduced to place the at least one first working oil cylinder 111 in a floating state, i.e., the at least one first working oil cylinder 111 is depressurized, thereby reducing the radial force applied to the lock pin 122 and unloading the radial load of the lock pin 122. At this time, the driving member 121 is used to drive the lock pin 122 out of the lock pin hole 321, which can reduce the difficulty of extracting the lock pin 122, achieve rapid extraction of the lock pin 122, and improve construction efficiency.

[0041] Optionally, when the oil pressure in the oil chamber of at least one first working cylinder 111 is less than or equal to a preset value, the oil pressure in the oil chamber of at least one first working cylinder 111 is the system standby oil pressure, or the oil pressure in the oil chamber of at least one first working cylinder 111 is equal to 0.

[0042] The at least one first working oil cylinder 111 is depressurized to the oil return port 152 of the oil source 150. When the oil pressure in the oil chamber of the at least one first working oil cylinder 111 is less than or equal to a preset value, the oil pressure in the oil chamber of the at least one first working oil cylinder 111 is the standby oil pressure of the system.

[0043] When relieving pressure from the at least one first working cylinder 111 to another oil tank, if the oil pressure in the oil chamber of the at least one first working cylinder 111 is less than or equal to a preset value, the oil pressure in the oil chamber of the at least one first working cylinder 111 may be zero. The oil pressure in the oil chamber of the at least one first working cylinder 111 being zero eliminates the pressure in the at least one first working cylinder 111, thereby further reducing the radial force applied to the lock pin 122 and completely unloading the radial load on the lock pin 122.

[0044] That is, the oil chamber of at least one first working oil cylinder 111 can be connected to the oil return port 152 of the oil source 150 or other oil tank through the control valve group 130 to relieve the pressure of the oil chamber of at least one first working oil cylinder 111.

[0045] Optionally, the preset value is 1 MPa or 2 MPa. When the oil pressure of the oil chamber of at least one first working oil cylinder 111 is relieved to the standby oil pressure of the system, the standby oil pressure is less than or equal to 1 MPa, or the standby oil pressure is less than or equal to 2 MPa.

[0046] Alternatively, the locking pin 122 is pulled out after the oil pressure of the oil chamber of at least one first working oil cylinder 111 is relieved to below 1 MPa or below 2 MPa.

[0047] Optionally, the left lifting cylinder and the right lifting cylinder can be in a floating state at the same time, or the left lifting cylinder and the swing cylinder can be in a floating state at the same time, or the right lifting cylinder and the swing cylinder can be in a floating state at the same time, or the left lifting cylinder, the right lifting cylinder and the swing cylinder can be in a floating state at the same time, so as to minimize the radial load applied to the locking pin 122 by each cylinder due to unbalanced pressure, and further realize the rapid removal of the locking pin 122.

[0048] In some embodiments, the control valve assembly 130 can make the oil pressure of the oil chamber of the at least one first working oil cylinder 111 equal to 0 MPa.

[0049] In this embodiment, the unbalanced force of at least one first working cylinder 111 is eliminated, thereby further reducing the radial force applied to the locking pin 122, achieving complete unloading of the radial load of the locking pin 122, and further reducing the difficulty of pulling out the locking pin 122.

[0050] Optionally, when the pressure of the at least one first working oil cylinder 111 is relieved to another oil tank, the oil pressure of the oil chamber of the at least one first working oil cylinder 111 may be relieved to 0 MPa.

[0051] When the left lifting cylinder, the right lifting cylinder and the swing cylinder are in the floating state at the same time, the first working device 330 floats to the ground.

[0052] As shown in Figures 1, 2 and 3, in some embodiments, the hydraulic control system 100 of the grader further includes a pump body assembly 140 and an oil source 150. Specifically, the pump body assembly 140 includes a first pump body 141, which can be connected to the cylinder assembly 110. The oil source 150 includes an oil outlet 151 and an oil return port 152. The oil outlet 151 is connected to the first pump body 141. The control valve group 130 can connect the oil chamber of at least one first working cylinder 111 with the oil return port 152; wherein, when the oil pressure of the oil chamber of at least one first working cylinder 111 is less than or equal to a preset value, the oil pressure of the oil chamber of the first working cylinder 111 is the standby oil pressure of the hydraulic control system 100 of the grader.

[0053] In this embodiment, the hydraulic control system 100 of the grader further includes a pump body assembly 140 and an oil source 150. Specifically, the pump body assembly 140 includes a first pump body 141, which can be connected to the cylinder assembly 110 to adjust the working posture of the first working device 330.

[0054] The first pump body 141 is connected to the oil outlet 151 of the oil source 150. Before the lock pin 122 is removed, the oil chamber of at least one first working oil cylinder 111 is connected to the oil return port 152 of the oil source 150 through the control valve group 130 to relieve the pressure in the oil chamber of at least one first working oil cylinder 111, thereby reducing the radial force applied to the lock pin 122 and unloading the radial load of the lock pin 122. At this time, the driving member 121 is used to drive the lock pin 122 out of the lock pin hole 321, which can reduce the difficulty of removing the lock pin 122, achieve rapid removal of the lock pin 122, and improve construction efficiency.

[0055] Optionally, the first pump body 141 includes an open plunger pump, wherein the open plunger pump includes a load-sensitive variable displacement pump or a fixed displacement pump. Specifically, the open plunger pump includes a load-sensitive variable displacement pump, which can realize self-regulation of displacement according to the load of the working cylinder.

[0056] Optionally, the load sensing variable displacement pump includes an LS oil port, which is communicated with the LS oil passage (the passage for controlling the load sensing function) of the control valve group 130 .

[0057] Optionally, the metering pump comprises a gear pump.

[0058] Optionally, the control valve group 130 includes an electrically controlled multi-way valve or a manual multi-way valve.

[0059] Optionally, the control valve group 130 includes a load-sensitive multi-way valve for a variable system or a load-sensitive multi-way valve for a quantitative system. The load-sensitive multi-way valve for a variable system is equipped with a load-sensitive variable pump, and the load-sensitive multi-way valve for a quantitative system is equipped with a quantitative pump.

[0060] As shown in Figures 1 and 3, in some embodiments, multiple first working cylinders 111 include a lifting cylinder 113, the oil chamber of the lifting cylinder 113 includes a first chamber 160 and a second chamber 170, the control valve group 130 includes a first control valve 131 and / or a second control valve 132, the first control valve 131 is connected to the first chamber 160, and is used to control the connection or cutoff of the first chamber 160 with the return oil port 152, and the second control valve 132 is connected to the second chamber 170, and is used to control the connection or cutoff of the second chamber 170 with the return oil port 152.

[0061] In this embodiment, the control valve assembly 130 is defined as including a first control valve 131 and / or a second control valve 132. Specifically, the first control valve 131 can control whether the first chamber 160 is connected to the oil return port 152, that is, the first control valve 131 can control whether the pressure in the first chamber 160 is relieved. The second control valve 132 can control whether the second chamber 170 is connected to the oil return port 152, that is, the second control valve 132 can control whether the pressure in the second chamber 170 is relieved.

[0062] When it is necessary to pull out the locking pin 122 to replace the locking pin hole 321, the first chamber 160 is connected to the oil return port 152 through the first control valve 131, and the second chamber 170 is connected to the oil return port 152 through the second control valve 132, so as to simultaneously relieve the pressure in the first chamber 160 and the second chamber 170 of the lifting cylinder 113, reduce the radial load applied to the locking pin 122, and reduce the difficulty of pulling out the locking pin 122.

[0063] Optionally, the first control valve 131 includes a solenoid valve or a manual valve.

[0064] Optionally, the second control valve 132 includes a solenoid valve or a manual valve.

[0065] Alternatively, if both first control valve 131 and second control valve 132 are solenoid valves, when the motor grader 300 is in operation, both the first solenoid valve (first control valve 131) and the second solenoid valve (second control valve 132) are de-energized. As shown in Figures 1 and 3, both the first and second solenoid valves are in the right position, and both the first and second chambers 160, 170 are disconnected from the oil return port 152. When the lock pin 122 needs to be removed, both the first and second solenoid valves are energized and in the left position. The first and second chambers 160, 170 are connected to the oil return port 152, respectively. The oil pressure in the first and second chambers 160, 170 drops to the system's standby oil pressure, causing the blade to float to the ground. The unbalanced force on the lift cylinder 113 is eliminated, unloading the lock pin 122, and driving the lock pin 122 out.

[0066] Optionally, the lift cylinder 113 includes a left lift cylinder and a right lift cylinder, and the number of first control valves 131 and second control valves 132 is two each. One pair of first control valves 131 and second control valves 132 respectively controls whether the first chamber 160 and second chamber 170 of the left lift cylinder are simultaneously depressurized. The other pair of first control valves 131 and second control valves 132 respectively controls whether the first chamber 160 and second chamber 170 of the right lift cylinder are simultaneously depressurized.

[0067] Optionally, the plurality of first working cylinders 111 further include a swing cylinder, and the first control valve 131 and the second control valve 132 respectively control whether the first chamber 160 and the second chamber 170 of the swing cylinder are depressurized simultaneously. Specific configurations can be made according to actual needs.

[0068] Optionally, each first working cylinder 111 further includes a first oil port and a second oil port, and the first pump body 141 can be connected to the first chamber 160 through the first oil port, and the first pump body 141 can also be connected to the second chamber 170 through the second oil port to adjust the working posture of the blade.

[0069] As shown in Figure 5, in some embodiments, multiple first working cylinders 111 include a lifting cylinder 113, the oil chamber of the lifting cylinder 113 includes a first chamber 160 and a second chamber 170, the control valve group 130 includes a third control valve 133, the third control valve 133 is connected to the first pump body 141 and the lifting cylinder 113, the third control valve 133 includes multiple working positions, the multiple working positions include a first working position and a second working position; wherein, when the third control valve 133 is in the first working position, the first chamber 160 and the second chamber 170 are respectively connected to the return oil port 152; when the third control valve 133 is in the second working position, one of the first chamber 160 and the second chamber 170 is connected to the first pump body 141, and the other is connected to the return oil port 152.

[0070] In this embodiment, another method of placing the first working cylinder 111 in a floating state is defined. Specifically, the control valve group 130 includes a third control valve 133 , which is connected to the first pump body 141 and the lifting cylinder 113 .

[0071] Third control valve 133 has multiple operating positions, including a first operating position and a second operating position. When third control valve 133 is in the first operating position, first chamber 160 and second chamber 170 of lift cylinder 113 are connected to oil return port 152, respectively, thereby relieving pressure in first chamber 160 and second chamber 170. In other words, when it is necessary to remove lock pin 122, third control valve 133 is first placed in the first operating position. After the oil pressure in first chamber 160 and second chamber 170 drops below a preset value, driver 121 is controlled to remove lock pin 122, thereby simplifying removal.

[0072] When the third control valve 133 is in the second working position, the first chamber 160 is in communication with the first pump body 141, and the second chamber 170 is in communication with the oil return port 152. Alternatively, the second chamber 170 is in communication with the first pump body 141, and the first chamber 160 is in communication with the oil return port 152. In other words, when the third control valve 133 is in the second working position, the working posture of the blade can be adjusted upward or downward.

[0073] Optionally, the plurality of first working cylinders 111 further include a swing cylinder, which is placed in different working positions through the third control valve 133 to control the swing cylinder to be in a blade posture adjustment or floating state.

[0074] Optionally, the third control valve 133 includes a reversing valve, wherein the reversing valve includes an electromagnetic reversing valve or a manual reversing valve.

[0075] As shown in Figure 5, in some embodiments, the multiple working positions also include a third working position; the hydraulic control system 100 of the grader also includes a hydraulic lock 180, which is arranged on the communication path between the third control valve 133 and the lifting cylinder 113, and the hydraulic lock 180 can be opened or closed; wherein, when the third control valve 133 is in the first working position or the second working position, the hydraulic lock 180 is opened; when the third control valve 133 is in the third working position, the hydraulic lock 180 is closed, and either the first chamber 160 or the second chamber 170 is cut off from the first pump body 141 and the return oil port 152.

[0076] In this embodiment, the hydraulic control system 100 of the grader is defined to also include a hydraulic lock 180. Specifically, the multiple working positions also include a third working position. When the third control valve 133 is in the third working position, the first chamber 160 is cut off from the first pump body 141 and the return oil port 152, and the second chamber 170 is cut off from the first pump body 141 and the return oil port 152, and the working position of the first working device 330 is locked.

[0077] Optionally, when the reversing valve includes an electromagnetic reversing valve, the electromagnetic reversing valve includes a first valve body 137 and a second valve body 138. Specifically, the first valve body 137 loses power, the second valve body 138 obtains the maximum blocking current, the electromagnetic reversing valve is in the lower position, the pilot oil circuit of the hydraulic lock 180 is the same as the pressure oil circuit, the hydraulic lock 180 is opened, the first chamber 160 and the second chamber 170 are both connected to the oil drain circuit (return oil port 152), and the lifting cylinder 113 floats, that is, the electromagnetic reversing valve is in the first working position.

[0078] When the first valve body 137 is energized and the second valve body 138 is de-energized, the electromagnetic reversing valve is in the upper position. The pilot oil circuit of the hydraulic lock 180 is the same as the pressure oil circuit. The hydraulic lock 180 is open, the first chamber 160 is connected to the pressure oil circuit (first pump body 141), and the second chamber 170 is connected to the oil return port 152. The lift cylinder 113 descends, adjusting the blade downward. This is the first condition of the electromagnetic reversing valve in the first working position.

[0079] The first valve body 137 loses power, the second valve body 138 receives mid-range current, the electromagnetic reversing valve is in the lower-middle position, the pilot oil circuit of the hydraulic lock 180 is the same as the pressure oil circuit, the hydraulic lock 180 opens, the second chamber 170 connects to the pressure oil circuit (first pump body 141), the first chamber 160 connects to the oil return port 152, and the lift cylinder 113 rises to adjust the blade upward. This is the second situation of the electromagnetic reversing valve in the first working position.

[0080] The first valve body 137 loses power, the second valve body 138 loses power, the electromagnetic reversing valve is in the middle position, the hydraulic lock 180 is closed, and the lifting cylinder 113 is locked, that is, the first chamber 160 is not connected to the pressure oil circuit and the return oil port 152, and the second chamber 170 is not connected to the pressure oil circuit and the return oil port 152. The blade position is locked for working conditions.

[0081] Optionally, the multiple first working cylinders 111 also include a swing cylinder, the control valve group 130 also includes a sixth control valve, the sixth control valve is connected to the first pump body 141 and the swing cylinder, the sixth control valve includes an electromagnetic reversing valve, the electromagnetic reversing valve includes a third valve body and a fourth valve body, the third valve body and the fourth valve body are both de-energized, the electromagnetic reversing valve is in the middle position, the hydraulic lock 180 is closed, the swing cylinder is locked, and the shovel position is locked for working conditions.

[0082] The third valve body is energized, the fourth valve body is de-energized, the electromagnetic reversing valve is in the upper position, the pilot oil circuit of the hydraulic lock 180 is connected to the pressure oil circuit, the hydraulic lock 180 is opened, the pressure oil enters the rodless chamber of the swing cylinder, the rod chamber of the swing cylinder is connected to the oil drain circuit (return oil port 152), and the swing cylinder is extended to the right swing working position, which is used to adjust the shovel blade posture to the right.

[0083] The third valve body loses power, the fourth valve body receives power, the electromagnetic reversing valve is in the lower position, the pilot oil circuit of the hydraulic lock 180 is connected to the pressure oil circuit, the hydraulic lock 180 is opened, the pressure oil enters the rod chamber of the swing cylinder, the rodless chamber of the swing cylinder is connected to the oil drain circuit, the swing cylinder retracts, and is in the left swing working position, which is used to adjust the blade posture to the left.

[0084] The first valve body 137 , the second valve body 138 , the third valve body and the fourth valve body are electrically connected to the display screen 310 of the motor grader 300 , and the motion control of each working cylinder is achieved by controlling the power supply or power loss of each valve body.

[0085] As shown in Figures 1 and 5, in some embodiments, the grader 300 also includes a second working device, the driving member 121 includes a driving cylinder 123; the cylinder assembly 110 also includes a second working cylinder 112, and the second working cylinder 112 is used to connect the second working device; the control valve group 130 also includes a fourth control valve 134, and the fourth control valve 134 is provided on the second working cylinder 112. The fourth control valve 134 can connect the second working cylinder 112 with the first pump body 141 to increase the main oil pressure of the hydraulic control system 100 of the grader; when the fourth control valve 134 connects the second working cylinder 112 with the first pump body 141, the control valve group 130 connects the driving cylinder 123 with the first pump body 141 to drive the locking pin 122 to move out of the locking pin hole 321.

[0086] In this embodiment, the control valve assembly 130 further includes a fourth control valve 134. Specifically, the cylinder assembly 110 further includes a second working cylinder 112, which is used to connect to a second working device. Optionally, the second working device includes a ripper, a bulldozer, a ripper harrow, or a front wheel tilt cylinder. In other words, the second working cylinder 112 includes a ripper cylinder, a bulldozer cylinder, a ripper harrow cylinder, or a front wheel tilt cylinder.

[0087] The driving member 121 is a driving cylinder 123 , which is in communication with the first pump body 141 . In other words, the locking pin 122 is driven to be inserted into or removed from the locking pin hole 321 by the driving cylinder 123 .

[0088] The fourth control valve 134 controls whether the second hydraulic cylinder 112 is connected to the first pump body 141. When the fourth control valve 134 connects the second hydraulic cylinder 112 to the first pump body 141, that is, when pressurized oil enters the oil chamber of the second hydraulic cylinder 112, the main oil pressure of the entire hydraulic control system is increased.

[0089] When the locking pin 122 needs to be pulled out, pressurized oil is first introduced into the second working cylinder 112 through the fourth control valve 134 to increase the main oil pressure of the entire hydraulic control system, and then the oil chamber of the driving cylinder 123 is connected to the first pump body 141 to drive the locking pin 122 out of the locking pin hole 321, which can increase the locking pin pulling-out force to meet the force required for pulling out the locking pin 122, thereby realizing the rapid pulling out of the locking pin 122.

[0090] In addition, before pulling out the locking pin 122, pressurized oil is introduced into the second working cylinder 112 so that the locking pin pulling-out force is greater than the locking pin insertion force. Compared with the related art in which the insertion force of the locking pin 122 cylinder is greater than the pulling-out force, the locking pin 122 is fit into the tapered sleeve, which can further reduce the radial load applied to the locking pin 122 by the tapered sleeve in the locking pin hole 321. As the equipment is used for a longer time, when the required locking pin pulling-out force increases due to wear, poor lubrication, rust and other factors of the locking pin 122 and the locking pin 122 tapered sleeve, the difficulty of pulling out the locking pin 122 is reduced, and the pulling-out force required for pulling out the locking pin 122 is met.

[0091] Specifically, the pulling out of the locking pin 122 from the oil cylinder depends on the main oil pressure of the system, according to the formula: out =P out ×S b ;

[0092] Among them, F out is the pin extraction force, P out To pull out the lock pin 122, press the oil pressure, S b The cross-sectional area is the cross-sectional area of ​​the first oil chamber 230 of the driving cylinder 123 minus the cross-sectional area of ​​the piston rod of the driving cylinder 123 .

[0093] Increasing the main oil pressure of the system correspondingly increases the oil pressure for pulling out the lock pin 122, thereby increasing the lock pin pulling force.

[0094] Optionally, the fourth control valve 134 includes a solenoid valve, and the solenoid valve is controlled to be energized, thereby controlling the second working cylinder 112 to communicate with the first pump body 141 .

[0095] Optionally, the driving cylinder 123 includes a first oil chamber 230 and a second oil chamber 240. When the first oil chamber 230 is in communication with the first pump body 141, the driving cylinder 123 drives the lock pin 122 into the lock pin hole 321. When the second oil chamber 240 is in communication with the first pump body 141, the driving cylinder 123 drives the lock pin 122 out of the lock pin hole 321. In other words, the first oil chamber 230 is a rodless chamber, and the second oil chamber 240 is a rod-mounted chamber.

[0096] Optionally, there are multiple second working cylinders 112 and multiple fourth control valves 134, and each fourth control valve 134 is connected to a second working cylinder 112. When the locking pin 122 needs to be pulled out, multiple second working cylinders 112 are controlled to be connected to the first pump body 141 through multiple fourth control valves 134.

[0097] Even if pressurized oil is introduced into multiple second working cylinders 112 so that the lock pin extraction force is much greater than the lock pin insertion force, compared with the related art in which the insertion force of the lock pin 122 cylinder is greater than the extraction force, so that the lock pin 122 is fitted into the tapered sleeve, the radial load applied to the lock pin 122 by the tapered sleeve in the lock pin hole 321 can be further reduced, and the difficulty of extracting the lock pin 122 can be further reduced. The force required for inserting and extracting the lock pin 122 throughout its life cycle can be met, and the problem of difficulty in extracting the lock pin 122 is effectively solved.

[0098] Optionally, the hydraulic control system 100 of the grader further includes multiple shuttle valves 190 and multiple compensation valves 220, the number of third control valves 133 is multiple, the multiple third control valves 133 are respectively connected to the multiple first working cylinders 111, and the multiple compensation valves 220 are respectively arranged at the outlets of the multiple third control valves 133 and the fourth control valve 134.

[0099] Specifically, the workload of each first working cylinder 111 is connected to the oil inlet of the corresponding shuttle valve 190 through the third control valve 133 connected thereto. Through the pressure comparison function of the shuttle valve 190, the maximum workload of all working cylinders is output to multiple compensation valves 220. Through the compensation valve 220, the outlet oil pressure of multiple third control valves 133 and the fourth control valve 134 is made consistent and maximum, ensuring the oil pressure required to drive each working cylinder to operate simultaneously.

[0100] Optionally, the hydraulic control system 100 of the grader further includes a second overflow valve 210, which connects the LS oil port of the first pump body 141 and the return oil port 152, thereby limiting the pressure of the LS oil circuit through the second overflow valve 210, thereby controlling the maximum oil pressure of the system and protecting the system.

[0101] In addition, through the oil pressure feedback of the LS oil port, the displacement of the first pump body 141 is adjusted to meet the flow required for the operation of the cylinder assembly 110.

[0102] As shown in Figure 3, in some embodiments, the grader 300 also includes a fan and a hydraulic motor 340, the hydraulic motor 340 is used to drive the fan, the driving member 121 includes a driving cylinder 123, the pump body assembly 140 also includes a second pump body 142, and the second pump body 142 is connected to the hydraulic motor 340; the control valve group 130 also includes a speed regulating valve 135, the speed regulating valve 135 is provided on the hydraulic motor 340, and the speed regulating valve 135 includes a first state and a second state; wherein, when the speed regulating valve 135 is in the first state, the speed of the hydraulic motor 340 is a first speed value, and the control valve group 130 enables the driving cylinder 123 to be connected with the second pump body 142 to drive the locking pin 122 to move out of the locking pin hole 321; when the speed regulating valve 135 is in the second state, the speed of the hydraulic motor 340 is a second speed value, and the second speed value is less than the first speed value.

[0103] In this embodiment, the control valve group 130 further includes a speed regulating valve 135 . Specifically, the motor grader 300 includes a hydraulic motor 340 and a fan. The hydraulic motor 340 is used to drive the fan to rotate so as to dissipate heat from the device to be dissipated.

[0104] The hydraulic motor 340 is connected to the second pump body 142, and the second pump body 142 can be connected to the driving cylinder 123. The increase in the speed of the hydraulic motor 340 can increase the main oil pressure of the oil circuit between the oil source 150, the second pump body 142 and the driving cylinder 123, that is, increase the main oil pressure of the second pump body 142.

[0105] The speed regulating valve 135 has a first state and a second state. When the speed regulating valve 135 is in the first state, the speed of the hydraulic motor 340 is greater than when the speed regulating valve 135 is in the second state. In other words, when the lock pin 122 needs to be removed, the speed regulating valve 135 is placed in the first state, causing the hydraulic motor 340 to operate at a high speed. This increases the main oil pressure of the second pump body 142, thereby increasing the lock pin removal force to meet the required force for removing the lock pin 122, thereby enabling rapid removal of the lock pin 122.

[0106] In addition, before pulling out the locking pin 122, by increasing the rotation speed of the hydraulic motor 340, the locking pin pulling-out force is made greater than the locking pin insertion force. Compared with the related art in which the insertion force of the locking pin 122 cylinder is greater than the pulling-out force, the locking pin 122 is made to fit into the tapered sleeve. This can further reduce the radial load applied to the locking pin 122 by the tapered sleeve in the locking pin hole 321. As the equipment is used for a longer time, when the required locking pin pulling-out force increases due to wear, poor lubrication, rust and other factors of the locking pin 122 and the locking pin 122 tapered sleeve, the difficulty of pulling out the locking pin 122 is reduced, and the pulling-out force required for pulling out the locking pin 122 is met.

[0107] When the lock pin 122 is pulled out, the speed regulating valve 135 is placed in the second state, thereby causing the hydraulic motor 340 to operate at a low speed.

[0108] Optionally, the second state includes an exit control state, that is, when the lock pin 122 is completely pulled out, the control of the speed regulating valve 135 is exited.

[0109] Optionally, the speed regulating valve 135 includes a proportional solenoid valve. When the proportional solenoid valve loses power, the speed of the hydraulic motor 340 is maximized, so that the lock pin extraction force is much greater than the insertion force, meeting the force required for the lock pin 122 to be inserted and removed throughout its life cycle.

[0110] That is, the rotation speed of the hydraulic motor 340 is adjusted by controlling the proportional solenoid valve to lose power or exit control.

[0111] Optionally, the speed of the hydraulic motor 340 is adjusted by controlling the magnitude of the applied current, which can be set according to actual needs.

[0112] Optionally, the first pump body 141 and the second pump body 142 may be connected to the same oil source 150 , or may be connected to different oil sources 150 .

[0113] Optionally, the second pump body 142 can obtain a pressure oil source 150 from a system having an independent oil source 150, such as a brake hydraulic system, a transmission hydraulic system, etc. The specific configuration can be made according to actual needs.

[0114] Optionally, the second pump body 142 includes a variable displacement pump or a fixed displacement pump.

[0115] Specifically, when the second pump body 142 includes a variable displacement pump, the variable displacement pump includes a load-sensing open-type plunger pump. When the second pump body 142 includes a fixed displacement pump, the fixed displacement pump includes a gear pump.

[0116] As shown in Figures 1, 3 and 5, in some embodiments, the driving cylinder 123 includes a first oil chamber 230 and a second oil chamber 240, and the control valve group 130 also includes a fifth control valve 136. The fifth control valve 136 is connected to the driving cylinder 123 and the pump body assembly 140. The fifth control valve 136 can connect the first oil chamber 230 or the second oil chamber 240 to the pump body assembly 140; when the fifth control valve 136 connects the first oil chamber 230 to the pump body assembly 140, the driving cylinder 123 drives the locking pin 122 to be inserted into any locking pin hole 321; the hydraulic control system 100 of the grader also includes a first overflow valve 250, which is connected to the first oil chamber 230 and can be connected to the oil return port 152.

[0117] In this embodiment, the control valve assembly 130 further includes a fifth control valve 136. Specifically, the fifth control valve 136 is connected to the driving cylinder 123 and the pump assembly 140. The fifth control valve 136 can connect the pump assembly 140 to the first oil chamber 230 or the second oil chamber 240 of the driving cylinder 123 to drive the lock pin 122 to be inserted into or removed from the lock pin hole 321.

[0118] Specifically, when the lock pin 122 needs to be inserted into the lock pin hole 321 , the fifth control valve 136 allows the pump body assembly 140 to communicate with the first oil chamber 230 , that is, the first oil chamber 230 is a rodless chamber.

[0119] When the lock pin 122 needs to be pulled out, the fifth control valve 136 allows the pump body assembly 140 to communicate with the second oil chamber 240 , that is, the second oil chamber 240 is a rodless chamber.

[0120] Optionally, the fifth control valve 136 includes a solenoid valve, which is energized or de-energized to control the pump body assembly 140 to communicate with the first oil chamber 230 or the second oil chamber 240 .

[0121] The hydraulic control system 100 of the motor grader further includes a first relief valve 250 . Specifically, the first relief valve 250 is connected to the first oil chamber 230 and the oil return port 152 .

[0122] When the locking pin 122 needs to be inserted into the locking pin hole 321, the fifth control valve 136 connects the pump body assembly 140 with the first oil chamber 230. When the locking pin 122 is inserted into place, due to the provision of the first overflow valve 250, when the oil pressure in the first oil chamber 230 is further increased, the first overflow valve 250 opens to overflow, thereby keeping the oil pressure in the first oil chamber 230 stable, meeting the force required for the insertion of the locking pin 122 while preventing the locking pin insertion force from being too large, thereby preventing the locking pin 122 from excessively fitting into the tapered sleeve in the locking pin hole 321, reducing the fitting force between the tapered sleeve and the locking pin 122, and when the locking pin 122 needs to be pulled out, the radial force of the tapered sleeve on the locking pin 122 can be reduced, thereby reducing the difficulty of pulling out the locking pin 122.

[0123] Specifically, according to the formula: F in =P in ×S a ;

[0124] Among them, F in is the locking pin insertion force, P in is the oil pressure of the first oil chamber 230, S a is the cross-sectional area of ​​the first oil chamber 230 of the driving cylinder 123 .

[0125] By setting the first overflow valve 250, the oil pressure in the first oil chamber 230 can be kept constant, that is, the locking pin insertion force can be kept at a constant value, which greatly reduces the engagement force between the taper sleeve and the locking pin 122, and solves the problem that the control pressure of the driving cylinder 123 is kept at a constant value, or the locking pin insertion force increases proportionally while the locking pin extraction force increases, thereby meeting the required locking pin insertion force while preventing the insertion force from being too large.

[0126] As shown in Figures 1, 3 and 5, in some embodiments, the hydraulic control system 100 of the grader further includes a filter assembly 280 and a flow limiting hole 260, wherein the inlet of the filter assembly 280 is connected to the pump body assembly 140, and the outlet of the filter assembly 280 can be connected to the cylinder assembly 110 and the driving cylinder 123, the inlet of the flow limiting hole 260 is connected to the outlet of the filter assembly 280 through the first pipeline 270, and the outlet of the flow limiting hole 260 is connected to the driving cylinder 123; wherein the flow cross-sectional area of ​​the flow limiting hole 260 is smaller than the flow cross-sectional area of ​​the first pipeline 270.

[0127] In this embodiment, the hydraulic control system 100 of the grader is defined to further include a filter assembly 280. Specifically, the oil flowing out of the pump body assembly 140 is filtered by the filter assembly 280 and then enters the cylinder assembly 110 or the drive cylinder 123, thereby filtering impurities in the hydraulic oil, ensuring the cleanliness of the oil in the entire system, and further ensuring the reliability and stability of the operation of the entire system.

[0128] The hydraulic control system 100 of the grader also includes a flow limiting hole 260. Specifically, the two ends of the flow limiting hole 260 are respectively connected to the filter assembly 280 and the driving cylinder 123. Since the flow cross-sectional area of ​​the flow limiting hole 260 is smaller than the flow cross-sectional area of ​​the first pipeline 270, the flow of the hydraulic oil entering the driving cylinder 123 is limited. While meeting the flow required for inserting and removing the locking pin 122, it prevents excessive flow entering the fifth control valve 136 when the system pressure is high, thereby preventing the problem of high system energy consumption, thereby ensuring stable operation of the system.

[0129] Optionally, the flow restriction hole 260 includes a damping hole.

[0130] Optionally, the hydraulic control system 100 of the grader further includes a one-way valve, which is located between the flow limiting hole 260 and the fifth control valve 136. The one-way valve is used to control the one-way conduction from the filter assembly 280 to the driving cylinder 123, thereby reversely locking the driving cylinder 123 in the shutdown state, that is, maintaining the pressure in the first oil chamber 230 of the driving cylinder 123 to prevent the locking pin 122 from withdrawing from the locking pin hole 321.

[0131] Specifically, when the locking pin 122 needs to be inserted into the locking pin hole 321, the solenoid valve (fifth control valve 136) loses power, and the pressure oil enters the first oil chamber 230 through the flow limiting hole 260, the one-way valve and the solenoid valve, and the hydraulic oil in the second oil chamber 240 flows to the return oil port 152.

[0132] When the lock pin 122 needs to be pulled out, the solenoid valve is energized, and the pressure oil enters the second oil chamber 240 through the flow limiting hole 260, the one-way valve and the solenoid valve, and the hydraulic oil in the first oil chamber 230 flows to the oil return port 152.

[0133] As shown in FIG. 2 , FIG. 4 and FIG. 6 , in some embodiments, the hydraulic control system 100 of the motor grader further includes a detection member 290 . The detection member 290 is provided on the locking pin assembly 120 and is used to detect whether the locking pin 122 is inserted into or removed from the locking pin hole 321 .

[0134] In this embodiment, the hydraulic control system 100 of the motor grader further includes a detection member 290. Specifically, the detection member 290 is provided on the locking pin assembly 120, and the detection member 290 is capable of detecting whether the locking pin 122 is inserted into or removed from the locking pin hole 321. That is, the detection member 290 detects whether the locking pin 122 is in an inserted state or a pulled-out state, thereby ensuring smooth operation of the motor grader 300.

[0135] Optionally, the detection member 290 is integrated on the driving cylinder 123 and is used to detect the displacement of the piston rod of the driving cylinder 123 to identify whether the locking pin 122 is in the inserted state or the pulled-out state.

[0136] Optionally, the detection member 290 includes other sensors such as a displacement sensor or a proximity switch.

[0137] According to the second aspect of the present application, a grader 300 is provided, comprising the hydraulic control system 100 of the grader provided in any of the above embodiments, and thus possessing all the beneficial technical effects of the hydraulic control system 100 of the grader, which will not be described in detail here.

[0138] As shown in FIG. 2 , FIG. 4 and FIG. 6 , in some embodiments, the motor grader 300 further includes a display screen 310 , which is electrically connected to the control valve assembly 130 .

[0139] In this embodiment, the motor grader 300 is further provided with a display screen 310 . Specifically, the display screen 310 is electrically connected to the control valve group 130 . The display screen 310 controls the movement of the cylinder assembly 110 through the control valve group 130 , thereby facilitating operation.

[0140] Optionally, the motor grader 300 further includes a controller, which is electrically connected to the control valve assembly 130 .

[0141] As shown in FIG10 , in a specific embodiment, the method for operating the locking pin (the hydraulic control method for the grader) includes:

[0142] Step 202, check whether the vehicle speed is 0, if the vehicle speed is zero, enter the lock pin removal control program;

[0143] Among them, it prevents the lock pin from being pulled out during driving, affecting driving safety.

[0144] Step 204 , energize the four solenoid valves of the floating valve group to float the left and right lifting cylinders, causing the blade to fall to the ground under its own weight, thereby unloading the lock pin.

[0145] Step 206: A solenoid valve in the control valve group is energized (any one of the ripper, bulldozer, ripper harrow, and front wheel tilt cylinder) to increase the system main oil pressure.

[0146] Among them, sufficient oil pressure is provided for pulling out the lock pin.

[0147] Step 208: The lock pin control solenoid valve is energized to start pulling out the lock pin. The lock pin piston rod oil cylinder displacement sensor detects that the lock pin has been pulled out and proceeds to the next step.

[0148] Step 210 , the four solenoid valves of the control float valve group are de-energized, and a certain solenoid valve in the control valve group is de-energized, and the floating state is exited, and the main oil pressure of the system drops to the previous pressure.

[0149] In this embodiment, the floating valve group includes multiple first control valves and multiple second control valves, which control the four solenoid valves of the floating valve group to be energized, that is, control the two first control valves and the two second control valves to be energized, so that the oil chambers of the two first working cylinders are connected to the oil return port for pressure relief.

[0150] When a certain solenoid valve in the control valve group is energized, the fourth control valve is controlled to be energized so that the pressure oil is supplied to the second working oil cylinder.

[0151] The left and right lifting cylinders are the two first working cylinders.

[0152] The lock pin control solenoid valve is the fifth control valve, and the lock pin piston rod cylinder displacement sensor is the detection component.

[0153] As shown in FIG11 , in another specific embodiment, the method for operating the locking pin (the hydraulic control method for the grader) includes:

[0154] Step 302, check whether the vehicle speed is 0, if the vehicle speed is zero, enter the lock pin removal control program;

[0155] Among them, it prevents the lock pin from being pulled out during driving, affecting driving safety.

[0156] Step 304: energize the four solenoid valves of the floating valve group to float the left and right lifting cylinders, causing the blade to fall to the ground under its own weight, thereby unloading the lock pin.

[0157] Step 306 , controlling the fan speed regulating valve solenoid valve to lose power and increasing the fan pump main oil pressure;

[0158] Step 308: The lock pin control solenoid valve is energized to start pulling out the lock pin. The lock pin piston rod oil cylinder displacement sensor detects that the lock pin has been pulled out and proceeds to the next step.

[0159] Step 310 , control the four solenoid valves of the floating valve group to lose power, exit the control of the fan speed regulating valve solenoid valve, exit the floating, and reduce the system main oil pressure to the previous pressure.

[0160] In this embodiment, the floating valve group includes multiple first control valves and multiple second control valves, which control the four solenoid valves of the floating valve group to be energized, that is, control the two first control valves and the two second control valves to be energized, so that the oil chambers of the two first working cylinders are connected to the oil return port for pressure relief.

[0161] The left and right lifting cylinders are the two first working cylinders.

[0162] The fan speed regulating valve solenoid valve is the solenoid valve. The fan pump is the second pump body.

[0163] The lock pin control solenoid valve is the fifth control valve, and the lock pin piston rod oil cylinder displacement sensor is the detection component.

[0164] As shown in FIG12 , in another specific embodiment, the method for pulling out the locking pin (the hydraulic control method for the grader) includes:

[0165] Step 402, checking whether the vehicle speed is 0, if the vehicle speed is zero, entering the lock pin removal control program;

[0166] Among them, it prevents the lock pin from being pulled out during driving, affecting driving safety.

[0167] Step 404: Control the multi-way valves D1 and D2 to obtain the maximum blocking current, and de-energize C1 and C2, so that the left and right lifting cylinders float, and the blade falls to the ground under its own weight, thus achieving lock pin unloading;

[0168] Step 406 , control the multi-way valve D4 to be energized and C4 to be de-energized, thereby increasing the system main oil pressure;

[0169] In step 408, the lock pin control solenoid valve is energized and begins to pull out the lock pin. The lock pin piston rod oil cylinder displacement sensor detects that the lock pin has been pulled out and then proceeds to the next step.

[0170] In step 410 , the multi-way valves D1 , D2 , and D4 are controlled to lose power, exit the floating state, and the main oil pressure of the system drops to the previous pressure.

[0171] In this embodiment, the multi-way valve includes a third control valve and a fourth control valve. There are two third control valves, which are respectively connected to different first working cylinders. C1 and C2 are respectively the first valve bodies of the two third control valves, and D1 and D2 are respectively the second valve bodies of the two third control valves.

[0172] The fourth control valve includes an electromagnetic reversing valve, which includes a fifth valve body and a sixth valve body. C4 is the fifth valve body, and D4 is the sixth valve body.

[0173] The lock pin control solenoid valve is the fifth control valve, and the lock pin piston rod oil cylinder displacement sensor is the detection component.

[0174] According to a third aspect of the present application, as shown in FIG9 , a hydraulic control method for a motor grader is provided. The motor grader includes a swing frame assembly, a first working device, a cylinder assembly, and a lock pin assembly. The cylinder assembly is connected to the swing frame assembly and the first working device. The cylinder assembly includes a plurality of first working cylinders. The swing frame assembly is provided with a plurality of lock pin holes. The lock pin assembly includes a connected driving member and a lock pin. The lock pin is configured to be inserted into or removed from any of the plurality of lock pin holes under the drive of the driving member. The control method includes:

[0175] Step 102: Controlling the pressure relief of the oil chamber of at least one first working oil cylinder so that the oil pressure of the oil chamber of at least one first working oil cylinder is less than or equal to a preset value;

[0176] Step 104: Control the driving member to drive the locking pin to move out of the locking pin hole.

[0177] The hydraulic control method of the grader provided in the embodiment of the present application is, specifically, the grader includes a swing frame assembly, a first working device, a cylinder assembly and a locking pin assembly, the cylinder assembly connects the swing frame assembly and the first working device, optionally, the first working device includes a blade.

[0178] There are multiple locking pin holes on the swing frame assembly. The locking pin assembly includes a connected locking pin and a driving member. Under the drive of the driving member, the locking pin can be inserted into or moved out of any locking pin hole, so that the first working device can switch between different working postures of the first working device by replacing the locking pin hole, and can operate under different working conditions such as earth leveling, ditch excavation and slope trimming.

[0179] When the locking pin needs to be removed from the lockpin hole for replacement, the imbalanced pressures within the multiple first working cylinders in the cylinder assembly exert a significant radial load on the lockpin. Furthermore, as the equipment ages and the bearings of the first operating device and the swing frame assembly wear, the imbalanced pressures within the cylinders increase during operation, making it difficult to remove the lockpin and impacting work efficiency.

[0180] The cylinder assembly includes a plurality of first working cylinders. Optionally, the plurality of first working cylinders include a lifting cylinder and a swing cylinder, wherein the lifting cylinder includes a left lifting cylinder and a right lifting cylinder.

[0181] Before pulling out the locking pin, the oil chamber of at least one first working oil cylinder is depressurized to reduce the oil pressure in the oil chamber of at least one first working oil cylinder. When the oil pressure in the oil chamber of at least one first working oil cylinder is less than or equal to a preset value, the control drive member drives the locking pin to move out of the locking pin hole.

[0182] In other words, before removing the locking pin, the at least one first hydraulic cylinder is depressurized, causing it to float, thereby reducing the radial force exerted on the locking pin and unloading the radial load. At this point, the driving member is then used to drive the locking pin out of the locking pin hole, which reduces the difficulty of removing the locking pin, enabling faster removal and improving construction efficiency.

[0183] Optionally, when the oil pressure in the oil chamber of at least one first working cylinder is less than or equal to a preset value, the oil pressure in the oil chamber of at least one first working cylinder is the system standby oil pressure, or the oil pressure in the oil chamber of at least one first working cylinder is equal to 0.

[0184] The at least one first working oil cylinder is depressurized to the oil return port of the oil source. When the oil pressure of the oil chamber of the at least one first working oil cylinder is less than or equal to a preset value, the oil pressure of the oil chamber of the at least one first working oil cylinder is the standby oil pressure of the system.

[0185] When relieving pressure from the at least one first working cylinder to another oil tank, the oil pressure in the oil chamber of the at least one first working cylinder may be zero when the oil pressure in the oil chamber of the at least one first working cylinder is less than or equal to a preset value. When the oil pressure in the oil chamber of the at least one first working cylinder is zero, the pressure in the at least one first working cylinder is eliminated, thereby further reducing the radial force applied to the lock pin and completely unloading the radial load on the lock pin.

[0186] That is, the oil chamber of the at least one first working oil cylinder can be connected to the oil return port of the oil source or other oil tanks through the control valve group to relieve the pressure of the oil chamber of the at least one first working oil cylinder.

[0187] Optionally, the preset value is 1 MPa or 2 MPa.

[0188] Optionally, the left lifting cylinder and the right lifting cylinder can be in a floating state at the same time, or the left lifting cylinder and the swing cylinder can be in a floating state at the same time, or the right lifting cylinder and the swing cylinder can be in a floating state at the same time, or the left lifting cylinder, the right lifting cylinder and the swing cylinder can be in a floating state at the same time, so as to minimize the radial load applied to the locking pin by each cylinder due to unbalanced pressure, and further realize the rapid removal of the locking pin.

[0189] In some embodiments, the driving member includes a driving cylinder, and the grader also includes a second working device, a first pump body and a second working cylinder. The first pump body is connected to the driving cylinder, and the second working cylinder is used to connect to the second working device. Before controlling the driving member to drive the locking pin out of the locking pin hole, it also includes: controlling the second working cylinder to connect to the first pump body.

[0190] In this embodiment, the second working cylinder is used to connect to the second working device. Optionally, the second working device includes a ripper, a bulldozer, a ripper harrow, or a front wheel tilt cylinder, that is, the second working cylinder includes a ripper cylinder, a bulldozer cylinder, a ripper harrow cylinder, or a front wheel tilt cylinder.

[0191] The driving member is a driving oil cylinder, which is connected to the first pump body. In other words, the locking pin is driven to be inserted into or removed from the locking pin hole by the driving oil cylinder.

[0192] When the locking pin needs to be pulled out, the second working cylinder is controlled to be connected with the first pump body, that is, pressurized oil is introduced into the second working cylinder to increase the main oil pressure of the entire hydraulic control system, and then the oil chamber of the driving cylinder is connected with the first pump body to drive the locking pin out of the locking pin hole. This can increase the locking pin pulling-out force to meet the force required for pulling out the locking pin, thereby realizing rapid pulling out of the locking pin.

[0193] In addition, before pulling out the locking pin, pressurized oil is introduced into the second working oil cylinder so that the locking pin pulling-out force is greater than the locking pin insertion force. Compared with the related art in which the insertion force of the locking pin cylinder is greater than the pulling-out force, the locking pin is engaged in the tapered sleeve. This can further reduce the radial load applied to the locking pin by the tapered sleeve in the locking pin hole. As the equipment is used for a longer time, the required pulling-out force of the locking pin increases due to wear, poor lubrication, rust and other factors of the locking pin and the locking pin tapered sleeve. This reduces the difficulty of pulling out the locking pin and meets the pulling-out force required for pulling out the locking pin.

[0194] Specifically, the locking pin pull-out cylinder depends on the system main oil pressure, according to the formula: F out =P out ×S b ;

[0195] Among them, F out is the pin extraction force, P out To pull out the lock pin, use oil pressure, S b It is the cross-sectional area of ​​the first oil chamber of the driving cylinder minus the cross-sectional area of ​​the piston rod of the driving cylinder.

[0196] Increasing the system main oil pressure will correspondingly increase the lock pin extraction oil pressure, which in turn can increase the lock pin extraction force.

[0197] Optionally, the drive cylinder includes a first oil chamber and a second oil chamber. When the first oil chamber is connected to the first pump body, the drive cylinder drives the lock pin into the lock pin hole. When the second oil chamber is connected to the first pump body, the drive cylinder drives the lock pin out of the lock pin hole. In other words, the first oil chamber is a rodless chamber, and the second oil chamber is a rod chamber.

[0198] Optionally, there are multiple second working oil cylinders, and when the lock pin needs to be pulled out, the multiple second working oil cylinders are controlled to be connected to the first pump body. Even if pressurized oil is supplied to the multiple second working oil cylinders, the lock pin extraction force is much greater than the lock pin insertion force. Compared with the lock pin cylinder in the related art where the insertion force is greater than the extraction force, so that the lock pin is engaged in the tapered sleeve, the radial load applied to the lock pin by the tapered sleeve in the lock pin hole can be further reduced, further reducing the difficulty of lock pin extraction, and meeting the force required for inserting and removing the lock pin throughout its life cycle, effectively solving the problem of difficult lock pin extraction.

[0199] In some embodiments, the driving member includes a driving cylinder, and the grader also includes a fan, a hydraulic motor and a second pump body. The hydraulic motor is used to drive the fan, and the second pump body is connected to the hydraulic motor and the driving cylinder. Before controlling the driving member to drive the locking pin out of the locking pin hole, it also includes: controlling the speed of the hydraulic motor to run at a first speed value; after controlling the driving member to drive the locking pin out of the locking pin hole, it also includes: controlling the speed of the hydraulic motor to run at a second speed value; wherein the second speed value is less than the first speed value.

[0200] In this embodiment, the motor grader includes a hydraulic motor and a fan. The hydraulic motor is used to drive the fan to rotate to dissipate heat from the device to be cooled.

[0201] The hydraulic motor is connected to the second pump body, which is in turn connected to the drive cylinder. When the speed of the hydraulic motor increases, the main oil pressure of the oil circuit between the oil source, the second pump body and the drive cylinder is increased, that is, the main oil pressure of the second pump body is increased.

[0202] In addition, before pulling out the locking pin, the rotation speed of the hydraulic motor is increased so that the locking pin pulling-out force is greater than the locking pin insertion force. Compared with the related technology in which the insertion force of the locking pin cylinder is greater than the pulling-out force, the locking pin is engaged in the tapered sleeve. This can further reduce the radial load applied to the locking pin by the tapered sleeve in the locking pin hole. As the equipment is used for a longer time, the required locking pin pulling-out force increases due to wear, poor lubrication, rust and other factors of the locking pin and the locking pin tapered sleeve. This reduces the difficulty of pulling out the locking pin and meets the pulling-out force required for pulling out the locking pin.

[0203] When the lock pin is pulled out, the hydraulic motor runs at a low speed.

[0204] In this specification, the terms "connect," "install," and "fix" should be understood broadly. For example, "connect" can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection or an indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0205] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0206] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A hydraulic control system for a grader, wherein: The grader includes a swing frame assembly and a first working device, the swing frame assembly is provided with a plurality of lock pin holes, and the hydraulic control system of the grader includes: A cylinder assembly connected to the swing frame assembly and the first working device, wherein the cylinder assembly includes a plurality of first working cylinders; A locking pin assembly, the locking pin assembly comprising a connected driving member and a locking pin, the locking pin being configured to be inserted into or removed from any of the plurality of locking pin holes under the driving of the driving member; A control valve group is connected to at least one of the first working cylinders. When the control valve group makes the oil pressure in the oil chamber of at least one of the first working cylinders less than or equal to a preset value, the driving member drives the locking pin to move out of the locking pin hole.

2. The hydraulic control system of a motor grader according to claim 1, wherein: The control valve group can make the oil pressure of the oil chamber of at least one of the first working cylinders equal to 0 MPa.

3. The hydraulic control system of a motor grader according to claim 1, wherein: The hydraulic control system of the grader further comprises: A pump body assembly, the pump body assembly comprising a first pump body, the first pump body being capable of communicating with the oil cylinder assembly; An oil source, the oil source comprising an oil outlet and an oil return port, the oil outlet being in communication with the first pump body, and the control valve group being capable of connecting the oil chamber of at least one of the first working oil cylinders with the oil return port; Wherein, when the oil pressure of the oil chamber of at least one of the first working oil cylinders is less than or equal to the preset value, the oil pressure of the oil chamber of the first working oil cylinder is the standby oil pressure of the hydraulic control system of the motor grader.

4. The hydraulic control system of a motor grader according to claim 3, wherein: The plurality of first working cylinders include a lifting cylinder, the oil chamber of the lifting cylinder includes a first chamber and a second chamber, and the control valve group includes: A first control valve is connected to the first chamber and is used to control the connection or cutoff between the first chamber and the oil return port; and / or, A second control valve is connected to the second chamber and is used to control the connection or cutoff between the second chamber and the oil return port; and / or, A third control valve connected to the first pump body and the lifting cylinder, the third control valve comprising a plurality of working positions, the plurality of working positions comprising a first working position and a second working position; Wherein, when the third control valve is in the first working position, the first chamber and the second chamber are respectively connected to the oil return port; When the third control valve is in the second working position, one of the first chamber and the second chamber is communicated with the first pump body, and the other is communicated with the oil return port.

5. The hydraulic control system of a motor grader according to claim 3, wherein: The motor grader further comprises a second working device, wherein the driving member comprises a driving cylinder; The cylinder assembly also includes: A second working cylinder, used for connecting the second working device; The control valve group also includes: a fourth control valve, provided at the second working oil cylinder, the fourth control valve being capable of connecting the second working oil cylinder with the first pump body to increase the main oil pressure of the hydraulic control system of the grader; When the fourth control valve connects the second working cylinder to the first pump body, the control valve group connects the driving cylinder to the first pump body to drive the lock pin to move out of the lock pin hole.

6. The hydraulic control system of a motor grader according to claim 3, wherein: The grader further comprises a fan and a hydraulic motor, wherein the hydraulic motor is used to drive the fan, the driving member comprises a driving cylinder, and the pump body assembly further comprises a second pump body, wherein the second pump body is connected to the hydraulic motor; The control valve group also includes: A speed regulating valve, provided on the hydraulic motor, the speed regulating valve includes a first state and a second state; Wherein, when the speed regulating valve is in the first state, the speed of the hydraulic motor is a first speed value, and the control valve group connects the driving cylinder with the second pump body to drive the locking pin to move out of the locking pin hole; When the speed regulating valve is in the second state, the rotation speed of the hydraulic motor is a second rotation speed value, and the second rotation speed value is smaller than the first rotation speed value.

7. The hydraulic control system of a motor grader according to claim 5 or 6, wherein: The driving oil cylinder includes a first oil chamber and a second oil chamber, and the control valve group also includes: a fifth control valve connected to the driving oil cylinder and the pump body assembly, wherein the fifth control valve is capable of connecting the first oil chamber or the second oil chamber to the pump body assembly; When the fifth control valve connects the first oil chamber with the pump body assembly, the driving cylinder drives the locking pin to be inserted into any one of the locking pin holes; the hydraulic control system of the grader also includes a first overflow valve, which is connected to the first oil chamber and can be connected to the oil return port.

8. The hydraulic control system of a motor grader according to claim 5 or 6, wherein: The hydraulic control system of the grader further comprises: A filter assembly, wherein the inlet of the filter assembly is in communication with the pump assembly, and the outlet of the filter assembly is in communication with the cylinder assembly and the driving cylinder; A flow limiting hole, wherein the inlet of the flow limiting hole is connected to the outlet of the filter assembly through a first pipeline, and the outlet of the flow limiting hole is connected to the driving cylinder; Wherein, the flow cross-sectional area of ​​the flow limiting hole is smaller than the flow cross-sectional area of ​​the first pipeline.

9. The hydraulic control system of a motor grader according to any one of claims 1 to 6, wherein: The hydraulic control system of the grader further comprises: A detection member is provided on the lock pin assembly and is used to detect whether the lock pin is inserted into or removed from the lock pin hole.

10. A motor grader, wherein: include: A hydraulic control system for a motor grader according to any one of claims 1 to 9; A display screen is electrically connected to the control valve group.

11. A hydraulic control method for a grader, wherein: The grader comprises a swing frame assembly, a first working device, a cylinder assembly and a lock pin assembly, wherein the cylinder assembly is connected to the swing frame assembly and the first working device, the cylinder assembly comprises a plurality of first working cylinders, the swing frame assembly is provided with a plurality of lock pin holes, the lock pin assembly comprises a connected driving member and a lock pin, the lock pin is configured to be able to be inserted into or removed from any of the plurality of lock pin holes under the drive of the driving member, and the control method comprises: Controlling the pressure relief of the oil chamber of at least one of the first working oil cylinders so that the oil pressure of the oil chamber of at least one of the first working oil cylinders is less than or equal to a preset value; The driving member is controlled to drive the locking pin to move out of the locking pin hole.

12. The hydraulic control method for a motor grader according to claim 11, wherein: The driving member includes a driving cylinder, the motor grader also includes a second working device, a first pump body and a second working cylinder, the first pump body is connected to the driving cylinder, the second working cylinder is used to connect the second working device, and before controlling the driving member to drive the locking pin to move out of the locking pin hole, the motor grader also includes: The second working oil cylinder is controlled to be connected to the first pump body.

13. The hydraulic control method for a motor grader according to claim 11, wherein: The driving member includes a driving cylinder, the motor grader also includes a fan, a hydraulic motor and a second pump body, the hydraulic motor is used to drive the fan, the second pump body is connected to the hydraulic motor and the driving cylinder, and before controlling the driving member to drive the lock pin to move out of the lock pin hole, the motor grader also includes: Controlling the speed of the hydraulic motor to operate at a first speed value; After controlling the driving member to drive the locking pin to move out of the locking pin hole, the method further includes: Controlling the speed of the hydraulic motor to operate at a second speed value; The second speed value is smaller than the first speed value.

Images