Hydraulic control method for land leveler, hydraulic control device of land leveler, and land leveler

Abstract

Provided in the present application are a hydraulic control method for a land leveler, a hydraulic control device of a land leveler, and a land leveler. The land leveler comprises a frame, a swing frame mechanism, an operating member, a plurality of driving oil cylinders and a lock pin assembly, wherein the swing frame mechanism is movably disposed on the frame; each driving oil cylinder is connected to the swing frame mechanism and the operating member; a plurality of lock pin holes are provided in the swing frame mechanism; and the lock pin assembly comprises a first driving member and a lock pin, which are connected to each other, the lock pin being configured to be capable of being inserted into or withdrawn from any one of the plurality of lock pin holes under the drive of the first driving member. The hydraulic control method comprises: controlling the pressure relief of oil cavities of at least two driving oil cylinders; when the oil pressure in the oil cavities of the at least two driving oil cylinders is less than or equal to a set value, controlling a swing frame mechanism to move relative to a frame, so as to align a lock pin with a target hole of the plurality of lock pin holes; and controlling a first driving member to drive the lock pin to be inserted into the target hole.

Description

Hydraulic control method of motor grader, hydraulic control device 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 November 21, 2023, with application number "202311558041.8" and application name "Hydraulic Control Method of Grader, Hydraulic Control Device 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 method for a motor grader, a hydraulic control device for a motor grader, and a motor grader. Background Art

[0003] As a kind of earth-moving and transporting machinery, the working device of the grader can be applied to different working conditions such as earthwork leveling, ditch excavation, and slope finishing by replacing the locking pin hole position.

[0004] Currently, the traditional method for replacing the locking pin holes on a motor grader's swing frame is manual replacement, which is difficult and inefficient. To reduce this difficulty, related technologies use hydraulic plug-in / plug-out systems to replace the locking pin holes. However, when the locking pin is removed, the kinematic coupling between the operating device and the swing frame mechanism creates non-unique motion, making it difficult to align the locking pin with the target hole, resulting in low efficiency and the risk of alignment failure.

[0005] Summary of the Invention

[0006] The embodiments of the present application are intended to solve or improve 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 method for a motor grader.

[0008] A second aspect of the embodiments of the present application provides a hydraulic control device for a motor grader.

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

[0010] In view of this, according to the first aspect of an embodiment of the present application, a hydraulic control method for a grader is provided, the grader includes a frame, a swing frame mechanism, a working piece, a plurality of driving cylinders and a locking pin assembly, the swing frame mechanism is movably arranged on the frame, each driving cylinder is connected to the swing frame mechanism and the working piece, the swing frame mechanism is provided with a plurality of locking pin holes, the locking pin assembly includes a connected first driving member and a locking pin, the locking pin is configured to be able to be inserted into or removed from any one of the plurality of locking pin holes under the drive of the first driving member, the hydraulic control method includes: controlling the oil chambers of at least two driving cylinders to release pressure; when the oil pressure of the oil chambers of at least two driving cylinders is less than or equal to a set value, controlling the swing frame mechanism to move relative to the frame so that the locking pin is opposite to a target hole position among the plurality of locking pin holes; controlling the first driving member to drive the locking pin to insert into the target hole position.

[0011] According to a second aspect of the present application, a hydraulic control device of a grader is provided, the grader includes a frame, a swing frame mechanism and a working piece, the swing frame mechanism is movably arranged on the frame, the swing frame mechanism is provided with a plurality of locking pin holes, the hydraulic control device includes: a plurality of driving cylinders, each driving cylinder is connected to the swing frame mechanism and the working piece; a locking pin assembly, the locking pin assembly includes a connected first driving member and a locking pin, the locking pin is configured to be able to be inserted into or removed from any one of the plurality of locking pin holes under the drive of the first driving member; a valve assembly, connected to at least two of the plurality of driving cylinders; wherein, when the valve assembly makes the oil pressure of the oil chambers of the at least two driving cylinders less than or equal to a set value, the swing frame mechanism can move relative to the frame so that the locking pin is opposite to a target hole position among the plurality of locking pin holes, and the first driving member drives the locking pin to insert into the target hole position.

[0012] According to the third aspect of the present application, a grader is provided, comprising a hydraulic control device for the grader as provided by any of the above technical solutions, thereby having all the beneficial technical effects of the hydraulic control device for the grader, which will not be repeated here.

[0013] Additional aspects and advantages of the present application will be given in the following description, and in part will become apparent from the following description, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] 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:

[0015] 1 to 6 are flowcharts of a hydraulic control method for a motor grader according to one embodiment of the present application;

[0016] 7-8 are schematic structural diagrams showing a hydraulic control device for a motor grader according to an embodiment of the present application;

[0017] 9-10 are schematic structural diagrams of a motor grader according to an embodiment of the present application.

[0018] 7 to 10 , the correspondence between the reference numerals and the component names is as follows: 100 hydraulic control device of the grader, 110 driving cylinder, 111 first lifting cylinder, 112 second lifting cylinder, 113 swing cylinder, 120 locking pin assembly, 121 locking pin, 122 first driving member, 130 valve assembly, 131 first valve group, 132 second valve group, 140 first detection member, 150 second detection member, 160 third detection member, 170 display device, 171 controller, 172 display screen, 180 switch member, 190 control valve, 300 grader, 310 frame, 320 swing frame mechanism, 321 locking pin hole, 322 first swing arm, 323 second swing arm, 324 third swing arm, 330 working member. DETAILED DESCRIPTION

[0019] 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.

[0020] 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.

[0021] 1 to 10 , a hydraulic control method for a motor grader, a hydraulic control device 100 for a motor grader, and a motor grader 300 according to some embodiments of the present application will be described below.

[0022] In one embodiment of the present application, as shown in FIG1 , a hydraulic control method for a motor grader is provided. The motor grader includes a frame, a swing frame mechanism, a working member, a plurality of drive cylinders, and a lock pin assembly. The swing frame mechanism is movably disposed on the frame. Each drive cylinder is connected to the swing frame mechanism and the working member. The swing frame mechanism is provided with a plurality of lock pin holes. The lock pin assembly includes a first drive member and a lock pin connected to each other. 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 first drive member. The hydraulic control method includes:

[0023] Step 102, controlling the oil chambers of at least two driving oil cylinders to release pressure;

[0024] Step 104: When the oil pressure in the oil chambers of at least two driving oil cylinders is less than or equal to a set value, control the swing frame mechanism to move relative to the frame so that the lock pin is aligned with a target hole position among the plurality of lock pin holes;

[0025] Step 106: Control the first driving member to drive the locking pin to insert into the target hole.

[0026] The hydraulic control method of the grader provided in the embodiment of the present application includes: before the swing frame mechanism moves relative to the frame to make the locking pin opposite to the target hole position, first relieving the pressure in the oil chambers of at least two driving cylinders; specifically, controlling the oil chambers of the at least two driving cylinders to be connected to the return oil port of the oil source respectively; when the oil pressure in the oil chambers of the at least two driving cylinders is less than or equal to the set value, the oil pressure in the oil chambers of the at least two driving cylinders is the standby oil pressure.

[0027] Alternatively, the oil chambers of at least two driving cylinders are controlled to communicate with an external oil tank. When the oil pressure in the oil chambers of the at least two driving cylinders is less than or equal to a set value, the oil pressure in the oil chambers of the at least two driving cylinders can be zero. Each driving cylinder is connected to the swing frame mechanism and the workpiece, so that the working posture of the workpiece can be adjusted under the drive of multiple driving cylinders.

[0028] The swing frame mechanism is provided with a plurality of locking pin holes, and the locking pin assembly includes a connected locking pin and a first driving member. Under the drive of the first driving member, the locking pin can be inserted into or removed from any locking pin hole, so that the working part can switch to different working postures of the working part by replacing the locking pin hole, and thus can operate under different working conditions such as earth leveling, ditch excavation and slope finishing.

[0029] The lockpin hole currently located in the lockpin is called the current hole position, and the lockpin hole to which the lockpin is intended to be switched is called the target hole position. When the motor grader wants to switch its working posture, that is, from the left ditching working posture to the left slope working posture, the lockpin needs to be moved out of the current hole position. The swing frame mechanism moves relative to the frame so that the lockpin hole corresponding to the left slope is aligned with the lockpin. After alignment, the first drive member drives the lockpin into the lockpin hole corresponding to the left slope, achieving the working posture switch.

[0030] However, when the locking pin is pulled out from the current hole position, due to the motion coupling between the swing frame mechanism and the workpiece, the swing frame mechanism has motion non-uniqueness when moving relative to the frame to align the target hole position, which increases the difficulty of centering the target hole position, reduces the hole changing efficiency, and there is a risk of centering failure.

[0031] By relieving the pressure in at least two driving cylinders before the swing frame mechanism moves relative to the frame, the workpiece falls to the ground under the action of its own gravity and is fixed to the ground by its own gravity, thereby achieving movement separation between the swing frame mechanism and the workpiece. When the swing frame mechanism moves relative to the frame to align the target hole position, it has movement uniqueness, thereby achieving accurate alignment between the locking pin and the target hole position, reducing the difficulty of aligning the locking pin and the target hole position, and improving the hole changing efficiency.

[0032] Optionally, the multiple drive cylinders include a first lift cylinder, a second lift cylinder, and a swing cylinder. Optionally, the set value is 1 MPa or 2 MPa. Optionally, the working member includes a blade. Optionally, the first drive member is a hydraulic cylinder. Where the first drive member is a hydraulic cylinder, the motor grader further includes a control valve connected to the hydraulic cylinder for controlling the flow between the rod chamber and rodless chamber of the hydraulic cylinder and the oil outlet and return port of the oil source, thereby driving the locking pin to be inserted into or removed from the locking pin hole.

[0033] In some embodiments, the multiple driving cylinders include a first lifting cylinder, a second lifting cylinder, and a swing cylinder, and controlling the pressure relief of the oil chambers of at least two driving cylinders specifically includes: controlling the pressure relief of the oil chamber of the first lifting cylinder and the oil chamber of the second lifting cylinder; or controlling the pressure relief of the oil chamber of the first lifting cylinder, the oil chamber of the second lifting cylinder, and the swing cylinder.

[0034] In this embodiment, the plurality of driving cylinders are defined to include a first lifting cylinder, a second lifting cylinder, and a swing cylinder. The first lifting cylinder and the second lifting cylinder are used to adjust the workpiece in the height direction, and the swing cylinder is used to adjust the workpiece to swing left or right.

[0035] Before the swing frame mechanism is moved relative to the frame, the oil chamber of the first lifting cylinder and the oil chamber of the second lifting cylinder are depressurized so that the oil pressure in the oil chamber of the first lifting cylinder and the oil pressure in the oil chamber of the second lifting cylinder are both less than or equal to the set value, that is, the first lifting cylinder and the second lifting cylinder are in a floating state. At this time, the workpiece falls to the ground under the action of its own gravity and is fixed to the ground by its own gravity, thereby realizing the movement separation between the swing frame mechanism and the workpiece. When the swing frame mechanism moves relative to the frame to align the target hole position, it has movement uniqueness, thereby realizing accurate alignment between the locking pin and the target hole position, reducing the difficulty of centering the locking pin and the target hole position, and improving the hole changing efficiency.

[0036] When the first lifting cylinder and the second lifting cylinder are in a floating state, the swing cylinder is used as a power source to drive the swing frame mechanism to move relative to the frame to align the locking pin with the target hole position, which is easy to control and does not require an additional power source to drive the swing frame mechanism, thereby reducing the production cost of the grader.

[0037] Alternatively, before the swing frame mechanism is moved relative to the frame, the oil chamber of the first lifting cylinder, the oil chamber of the second lifting cylinder and the oil chamber of the swing cylinder are depressurized so that the oil pressure in the oil chamber of the first lifting cylinder, the oil pressure in the oil chamber of the second lifting cylinder and the oil pressure in the oil chamber of the swing cylinder are all less than or equal to the set value, that is, the first lifting cylinder, the second lifting cylinder and the swing cylinder are all in a floating state. At this time, the workpiece falls to the ground under the action of its own gravity and is fixed to the ground by its own gravity, thereby realizing the motion separation between the swing frame mechanism and the workpiece. When the swing frame mechanism moves relative to the frame to align the target hole position, it has motion uniqueness, thereby realizing accurate alignment between the locking pin and the target hole position, reducing the difficulty of centering the locking pin and the target hole position, and improving the hole changing efficiency.

[0038] After the swing mechanism is separated from the workpiece, at least one of the first, second, and swing cylinders can be used as a power source to drive the swing mechanism. However, before using it as a power source, it must first be released from the floating state. This means that the oil chamber of at least one of the first, second, and swing cylinders must be disconnected from the oil return port or an external oil tank.

[0039] For example, using the first lifting cylinder as the power source, first, the oil chamber of the first lifting cylinder is controlled to be cut off from the oil return port or the external oil tank, that is, the pressure relief is stopped, and then, the rodless chamber of the first lifting cylinder is controlled to connect to the oil outlet of the oil source, so that the first lifting cylinder drives the swing frame mechanism to move.

[0040] Optionally, the first lifting cylinder includes a cylinder body and a piston rod, wherein a first end of the piston rod is connected to the workpiece, and a second end of the piston rod is located within the cylinder body. The cylinder body is movably connected to the swing frame mechanism. When the workpiece lands, hydraulic oil is introduced into the rodless chamber, causing the cylinder body to move relative to the piston rod, thereby driving the swing frame mechanism. This allows the first lifting cylinder to drive the swing frame mechanism to move even when the swing frame mechanism and the workpiece are separated in motion, thereby aligning the lock pin with the target hole.

[0041] In some embodiments, before controlling the oil chambers of at least two driving cylinders to release pressure, it also includes: controlling the piston rod of the swing cylinder to extend or retract a preset length according to the positional relationship between the current hole position of the locking pin and the target hole position.

[0042] In this embodiment, before relieving the pressure in the oil chambers of at least two driving cylinders, the piston rod of the swing cylinder is controlled to extend or retract a preset length according to the position between the current hole position of the locking pin and the target hole position to be switched.

[0043] The cylinder body of the swing cylinder is connected to the working part, the first end of the piston rod of the swing cylinder is located in the cylinder body, and the second end of the piston rod is connected to the swing frame mechanism. Before the swing frame mechanism moves relative to the frame to align the locking pin with the target hole position, the piston rod of the swing cylinder is first controlled to extend or retract a certain length, so that the swing frame mechanism has sufficient movement space when moving relative to the frame, thereby ensuring that the swing frame mechanism can move relative to the frame, or the swing frame mechanism can cross more locking pin holes at one time when moving, which can further improve the hole changing efficiency.

[0044] In some embodiments, the piston rod of the swing cylinder is controlled to extend or retract a preset length based on the positional relationship between the current hole position where the locking pin is located and the target hole position, specifically including: judging whether the target hole position is located on the first side of the current hole position; when the target hole position is located on the first side of the current hole position, controlling the piston rod of the swing cylinder to extend a preset length; when the target hole position is not located on the first side of the current hole position, controlling the piston rod of the swing cylinder to retract a preset length.

[0045] In this embodiment, multiple locking pin holes are spaced apart on the swing frame mechanism, and the piston rod of the swing cylinder can be determined to extend or retract a certain length based on the direct positional relationship between the current hole position of the locking pin and the target hole position.

[0046] Specifically, it is determined whether the target hole position is located on the first side of the current hole position. If so, the piston rod of the swing cylinder is controlled to extend by a preset length, thereby ensuring that the piston rod of the swing cylinder has sufficient space to retract when the swing frame mechanism moves relative to the frame. If not, the piston rod of the swing frame is controlled to retract by a preset length, thereby ensuring that the piston rod of the swing cylinder has sufficient space to extend when the swing frame mechanism moves relative to the frame.

[0047] For example, the first side includes the left side. Before moving the swing mechanism relative to the frame, it is first determined whether the target hole position is located to the left of the current hole position. If so, the swing mechanism needs to be shifted rightward so that the locking pin is aligned with the target hole position, i.e., the piston rod of the swing cylinder needs to be retracted. Therefore, before the swing mechanism is shifted rightward, the piston rod of the swing cylinder is first extended by a preset length to ensure that the swing cylinder has room to retract during the swing mechanism movement. If not, i.e., the target hole position is located to the right of the current hole position, the swing mechanism needs to be shifted leftward so that the locking pin is aligned with the target hole position, i.e., the piston rod of the swing cylinder needs to be extended. Therefore, before the swing mechanism is shifted leftward, the piston rod of the swing cylinder is first extended by a retraction length to ensure that the swing cylinder has room to extend during the swing mechanism movement. Optionally, the piston rod of the swing cylinder can be fully extended or fully retracted, thereby reserving as much retraction space or extension space as possible when the swing mechanism moves relative to the frame.

[0048] In some embodiments, controlling the swing frame mechanism to move relative to the frame specifically includes: controlling at least one driving cylinder to stop depressurizing, and controlling the at least one driving cylinder that stops depressurizing to drive the swing frame mechanism to move relative to the frame; or controlling the remaining driving cylinders among the multiple driving cylinders to drive the swing frame mechanism to move relative to the frame; or controlling the second driving member of the grader to drive the swing frame mechanism to move relative to the frame.

[0049] In this embodiment, at least one of the at least two driving cylinders that are in a floating state is controlled to stop depressurizing and drive the swing mechanism relative to the frame. Specifically, at least one of the at least two driving cylinders in a floating state is released from the floating state and serves as the power source for driving the swing mechanism to align the locking pin with the target hole. By utilizing the motor grader's inherent power source, there is no need for a separate power source to drive the swing mechanism, thus reducing the production cost of the motor grader.

[0050] For example, if the first, second, and swing cylinders are all in a floating state and the workpiece lands, the first lift cylinder is used as the power source. First, the oil chamber of the first lift cylinder is disconnected from the oil return port or an external oil tank, thereby stopping pressure relief and exiting the floating state. Then, the rodless chamber of the first lift cylinder is connected to the oil outlet of the oil source, thereby causing the first lift cylinder to drive the swing frame mechanism. Alternatively, the remaining drive cylinders among the multiple drive cylinders are controlled to drive the swing frame mechanism to move relative to the frame, i.e., the drive cylinders not in the floating state serve as the power source for driving the swing frame mechanism to align the lock pin with the target hole.

[0051] For example, when the first and second lift cylinders are in a floating state and the workpiece lands, the swing cylinder serves as the power source for driving the swing mechanism relative to the frame to align the locking pin with the target hole. This facilitates control and eliminates the need for a separate power source to drive the swing mechanism, reducing the production cost of the motor grader. Alternatively, if both the first and second lift cylinders serve as the power sources for driving the swing mechanism, the first lift cylinder must first be released from the floating state. Alternatively, the motor grader may further include a second drive element. Specifically, after the swing mechanism is decoupled from the workpiece, the second drive element drives the swing mechanism relative to the frame. This additional drive element serves as the power source for driving the swing mechanism to align the locking pin with the target hole.

[0052] Before driving the swing mechanism, the first lifting cylinder, the second lifting cylinder, and the swing cylinder can all be placed in a floating state. This allows for complete decoupling of the working member from the swing mechanism during movement, simplifying the drive mechanism, further enabling accurate alignment of the locking pin with the target hole position, and improving hole-changing efficiency. Optionally, the second driving member comprises a hydraulic cylinder.

[0053] In some embodiments, after controlling the pressure relief of the oil chambers of at least two driving cylinders, it also includes: when the oil pressure of the oil chambers of at least two driving cylinders is less than or equal to a set value, controlling the first driving member to drive the locking pin out of the current hole position of the multiple locking pin holes.

[0054] In this embodiment, after depressurizing at least two drive cylinders and before moving the swing mechanism relative to the frame to align the locking pin with the target hole, the first drive member is controlled to drive the locking pin out of its current hole position. In other words, before removing the locking pin, the oil pressure in the oil chambers of at least two drive cylinders is reduced, placing the at least two drive cylinders 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 first drive member is then controlled to drive the locking pin out of its current hole position, reducing the difficulty of removing the locking pin, enabling faster removal and improving construction efficiency.

[0055] In some embodiments, the swing frame mechanism is controlled to move relative to the frame so that the locking pin is opposite to the target hole position among the multiple locking pin holes, which specifically also includes: detecting the swing angle of the swing frame mechanism; when the swing angle is equal to the set angle, determining that the locking pin is opposite to the target hole position corresponding to the set angle.

[0056] In this embodiment, when each locking pin hole is opposite to the locking pin, the swing frame mechanism has a corresponding swing angle, that is, the swing angle of the swing frame mechanism has a one-to-one correspondence with the locking pin hole.

[0057] Therefore, as the swing mechanism moves relative to the frame to align the locking pin with the target hole position, the swing angle of the swing mechanism is detected in real time. When the detected swing angle matches the swing angle corresponding to the target hole position, the locking pin is determined to be aligned with the target hole position. At this point, the first drive member is controlled to drive the locking pin into the target hole position, achieving accurate alignment between the locking pin and the target hole position. Compared to related technologies that compare the real-time displacement of the cylinder with pre-calibrated cylinder displacement data for judgment, this reduces calibration work, simplifies the control process, improves hole-changing efficiency, achieves full working condition coverage, and reduces the risk of alignment failure.

[0058] In some embodiments, the swing frame mechanism includes a first swing arm, a second swing arm and a third swing arm, one end of the first swing arm and one end of the second swing arm are respectively movably connected to the frame, and both ends of the third swing arm are respectively movably connected to the other end of the first swing arm and the other end of the second swing arm, and the third swing arm is provided with multiple locking pin holes, and detecting the swing angle of the swing frame mechanism specifically includes: detecting the swing angle of the first swing arm or the second swing arm relative to the frame; and / or detecting the swing angle of the first swing arm or the second swing arm relative to the third swing arm.

[0059] In this embodiment, the swing frame mechanism includes a first swing arm, a second swing arm, and a third swing arm. Specifically, one end of the first swing arm and one end of the second swing arm are respectively connected to the frame via kinematic pairs, i.e., movable connections. The two ends of the third swing arm are respectively connected to the other ends of the first swing arm and the other ends of the second swing arm via kinematic pairs, i.e., movable connections. In other words, the swing frame mechanism is a quadrilateral linkage mechanism.

[0060] The swing angle of the first or second swing arm relative to the frame is detected in real time. Alternatively, the swing angle of the first or second swing arm relative to the third swing arm is detected. Alternatively, the swing angle of the first or second swing arm relative to the frame and the swing angle of the first or second swing arm relative to the third swing arm are detected. Specifically, the angle sensor can be installed at the connection between the first swing arm and the frame, the connection between the second swing arm and the frame, the connection between the first swing arm and the third swing arm, or the connection between the second swing arm and the third swing arm. The specific installation can be based on actual needs.

[0061] In some embodiments, controlling the first driving member to drive the locking pin to insert into the target hole position specifically includes: when the number N of locking pin holes between the current hole position where the locking pin is located and the target hole position is greater than the maximum number n of locking pin holes that the swing frame mechanism can move each time, determining the number of hole changes based on the number of locking pin holes N and the number of locking pin holes n, the number of hole changes d = ROUNDUP[(N+1) / n]; controlling the first driving member to drive the locking pin to move based on the number of hole changes so that the locking pin is inserted into the target hole position.

[0062] In this embodiment, when the number of locking pin holes between the current hole position and the target hole position is greater than the maximum number of locking pin holes that the swing frame mechanism can move at one time, that is, when the swing frame mechanism cannot complete the alignment of the target hole position and the locking pin in one movement, the locking pin cannot directly change the hole to the target hole position in one time, and it is necessary to change the hole to the target hole position in multiple times.

[0063] The number of hole-changing times is determined based on the number of locking pin holes between the current hole position and the target hole position, as well as the maximum number of locking pin holes that the swing mechanism can move at one time. Specifically, d = ROUNDUP[(N+1) / n], where (N+1) / n is rounded up to the nearest integer. This means that the swing mechanism is moved each time according to the maximum number of locking pin holes it can move until the target hole position is reached, ensuring maximum hole-changing efficiency.

[0064] In one embodiment of the present application, as shown in FIG2 , a hydraulic control method for a motor grader is proposed. The control method includes:

[0065] Step 202, detect the current vehicle speed V; Step 204, determine V = 0, if so, go to step 206, if not, go to step 208; Step 206, input the target lock pin hole position; Step 208, stop the car, put the car in P gear, and go to step 202; Step 210, determine whether the target lock pin hole position is on the left side of the current hole position, if so, go to step 212, if not, go to step 214; Step 212, control the oil cylinder control valve group to drive the swing oil cylinder to fully extend, and go to step 216; Step 214, control the oil cylinder control valve group to drive the swing oil cylinder to fully retract, and go to step 216; Step 216, control the oil cylinder floating valve group to float the left and right lifting oil cylinders and the shovel blade falls to the ground; Step 218, control the lock pin control valve to make the lock pin oil The cylinder piston rod retracts, and the lock pin cylinder displacement sensor monitors the lock pin is pulled out and then proceeds to the next step; step 220, controls the cylinder floating valve group to make the swing cylinder float and the right lifting cylinder exit floating; step 222, controls the cylinder control valve group to extend (retract) the right lifting cylinder piston rod and drive the swing arm to move right (left) to complete the lock pin hole centering; step 224, determines whether the swing arm angle A0 corresponding to the target lock pin hole position is equal to the real-time swing arm angle A, if so, proceeds to step 226, if not, proceeds to step 222; step 226, controls the lock pin control valve to extend the lock pin cylinder piston rod, and the lock pin cylinder displacement sensor monitors the lock pin is inserted and then proceeds to the next step; step 228, controls the cylinder floating valve group to make the left lifting cylinder and the swing cylinder exit floating.

[0066] In this embodiment, the cylinder control valve group is the second valve group, the cylinder floating valve group is the first valve group, the lock pin control valve is the control valve, and the lock pin cylinder is the first driving member.

[0067] In one embodiment of the present application, as shown in FIG3 , a hydraulic control method for a motor grader is proposed. The control method includes:

[0068] Step 302, detect the current vehicle speed V; Step 304, determine V = 0, if so, go to step 306, if not, go to step 308; Step 306, input the target lock pin hole position; Step 308, stop the car, put the car in P gear, and go to step 302; Step 310, determine whether the target lock pin hole position is on the left side of the current hole position, if so, go to step 312, if not, go to step 314; Step 312, control the oil cylinder control valve group to drive the swing oil cylinder to fully extend, and go to step 316; Step 314, control the oil cylinder control valve group to drive the swing oil cylinder to fully retract, and go to step 316; Step 316, control the oil cylinder floating valve group to float the left and right lifting oil cylinders and the shovel blade lands; Step 318, control the lock pin control valve to make the lock pin oil The cylinder piston rod retracts, and the lock pin cylinder displacement sensor monitors the lock pin is pulled out and then proceeds to the next step; step 320, controls the cylinder floating valve group to make the swing cylinder float and the left lifting cylinder exit floating; step 322, controls the cylinder control valve group to extend (retract) the left lifting cylinder piston rod and drive the swing arm to move left (right) to complete the lock pin hole centering; step 324, determines whether the swing arm angle A0 corresponding to the target lock pin hole position is equal to the real-time swing arm angle A, if so, proceeds to step 326, if not, proceeds to step 322; step 326, controls the lock pin control valve to extend the lock pin cylinder piston rod, and the lock pin cylinder displacement sensor monitors the lock pin is inserted and then proceeds to the next step; step 328, controls the cylinder floating valve group to make the right lifting cylinder and the swing cylinder exit floating.

[0069] In one embodiment of the present application, as shown in FIG4 , a hydraulic control method for a motor grader is proposed. The control method includes:

[0070] Step 402, detect the current vehicle speed V; Step 404, determine V = 0, if so, go to step 406, if not, go to step 408; Step 406, input the target lock pin hole position; Step 408, stop the car, put the car in P gear, and go to step 402; Step 410, determine whether the target lock pin hole position is on the left side of the current hole position, if so, go to step 412, if not, go to step 414; Step 412, control the oil cylinder control valve group to drive the swing oil cylinder to fully extend, and go to step 416; Step 414, control the oil cylinder control valve group to drive the swing oil cylinder to fully retract, and go to step 416; Step 416, control the oil cylinder floating valve group to float the left and right lifting oil cylinders and let the shovel fall to the ground; Step In step 418, the lock pin control valve is controlled to retract the piston rod of the lock pin cylinder, and the lock pin cylinder displacement sensor monitors the removal of the lock pin before proceeding to the next step; in step 420, the cylinder control valve group is controlled to extend (retract) the piston rod of the swing cylinder, and drive the swing arm to move left (right) to complete the centering of the lock pin hole; in step 422, it is determined whether the swing arm angle A0 corresponding to the target lock pin hole position is equal to the real-time swing arm angle A, if so, proceed to step 424, if not, proceed to step 420; in step 424, the lock pin control valve is controlled to extend the piston rod of the lock pin cylinder, and the lock pin cylinder displacement sensor monitors the insertion of the lock pin before proceeding to the next step; in step 426, the cylinder floating valve group is controlled to make the left lifting cylinder and the right lifting cylinder exit floating.

[0071] In one embodiment of the present application, as shown in FIG5 , a hydraulic control method for a motor grader is proposed. The control method includes:

[0072] Step 502, detecting the current vehicle speed V;

[0073] Step 504, determine if V=0, if so, go to step 506, if not, go to step 508;

[0074] Step 506, input the target lock pin hole position;

[0075] Step 508: Stop the car, shift to P gear, and proceed to step 502;

[0076] Step 510, determine whether the target lock pin hole position is to the left of the current hole position, if so, proceed to step 512, if not, proceed to step 528;

[0077] Step 512: Control the oil cylinder control valve group to drive the swing oil cylinder to fully extend;

[0078] Step 514: Control the oil cylinder floating valve group to float the left and right lifting oil cylinders and land the shovel blade.

[0079] Step 516: Control the lock pin control valve to retract the piston rod of the lock pin cylinder. The lock pin cylinder displacement sensor monitors that the lock pin is pulled out before proceeding to the next step.

[0080] Step 518: Control the cylinder float valve group to float the swing cylinder and the left lift cylinder, and stop the right lift cylinder from floating.

[0081] Step 520: Control the oil cylinder control valve group to extend the piston rod of the right lift oil cylinder, driving the swing arm to move rightward to align the lock pin hole;

[0082] Step 522, determine whether the swing arm angle A0 corresponding to the target lock pin hole position is equal to the real-time swing arm angle A, if so, proceed to step 524, if not, proceed to step 520;

[0083] Step 524: Control the lock pin control valve to extend the piston rod of the lock pin oil cylinder. The lock pin oil cylinder displacement sensor monitors whether the lock pin is inserted and then proceeds to the next step.

[0084] Step 526, controlling the cylinder float valve group to make the left lift cylinder and the swing cylinder stop floating;

[0085] Step 528: Control the oil cylinder control valve group to drive the swing oil cylinder to fully retract;

[0086] Step 530: Control the oil cylinder floating valve group to float the left and right lifting oil cylinders and land the shovel blade.

[0087] Step 532: Control the lock pin control valve to retract the piston rod of the lock pin oil cylinder. The lock pin oil cylinder displacement sensor monitors that the lock pin is pulled out and then proceeds to the next step.

[0088] Step 534, control the cylinder float valve group to float the swing cylinder and the right lift cylinder, and stop the left lift cylinder from floating;

[0089] Step 536 , controlling the oil cylinder control valve group to extend the piston rod of the left lift oil cylinder, driving the swing arm to move leftward to align the lock pin hole;

[0090] Step 538, determine whether the swing arm angle A0 corresponding to the target lock pin hole position is equal to the real-time swing arm angle A, if so, proceed to step 540, if not, proceed to step 536;

[0091] Step 540: Control the lock pin control valve to extend the piston rod of the lock pin oil cylinder. The lock pin oil cylinder displacement sensor monitors whether the lock pin is inserted and then proceeds to the next step.

[0092] Step 542, control the cylinder floating valve group to make the right lifting cylinder and the swing cylinder stop floating.

[0093] In one embodiment of the present application, as shown in FIG6 , a hydraulic control method for a motor grader is proposed. The control method includes:

[0094] Step 602, detecting the current vehicle speed V;

[0095] Step 604, determine if V=0, if so, go to step 606, if not, go to step 608;

[0096] Step 606, input the target lock pin hole position;

[0097] Step 608: Stop the car, shift to P gear, and proceed to step 602;

[0098] Step 610: Determine whether the target lock pin hole is to the left of the current hole. If so, control the swing cylinder to fully extend; otherwise, control the swing cylinder to fully retract.

[0099] Step 612, calculate the number of lock pin hole changes, read the interval N between the target lock pin hole position and the current hole position, and calculate the number of hole changes Ni = ROUNDUP [(N + 1) / N0];

[0100] Step 614, the i-th automatic lock pin hole change process, controls the left lift cylinder, right lift cylinder, swing cylinder, and lock pin cylinder to drive the lock pin, swing frame mechanism, and operating device to complete the lock pin extraction, centering, and insertion, completing the i-th automatic lock pin hole change process. The number of holes changed in one time is N0;

[0101] Step 616: Determine whether the target lock pin hole is to the left of the current hole. If so, control the swing cylinder to fully extend; otherwise, control the swing cylinder to fully retract.

[0102] Step 618, the Ni-th automatic lock pin hole change, controls the left lifting cylinder, right lifting cylinder, swing cylinder and lock pin cylinder to drive the lock pin, swing frame mechanism and operating device to move, complete the lock pin extraction, centering and insertion, and complete the entire lock pin automatic hole change process.

[0103] According to a second aspect of the present application, as shown in Figures 7, 8, 9 and 10, a hydraulic control device 100 for a motor grader is provided. The motor grader 300 includes a frame 310, a swing frame mechanism 320 and a working member 330. The swing frame mechanism 320 is movably arranged on the frame 310. The swing frame mechanism 320 is provided with a plurality of lock pin holes 321. The hydraulic control device includes: a plurality of driving cylinders 110, each driving cylinder 110 is connected to the swing frame mechanism 320 and the working member 330; a lock pin assembly 120, the lock pin assembly 120 including a first driving member 122 and a lock pin 121 connected thereto. 1. The lock pin 121 is configured to be able to be inserted into or removed from any lock pin hole 321 among the multiple lock pin holes 321 under the drive of the first driving member 122; the valve assembly 130 is connected to at least two driving cylinders 110 among the multiple driving cylinders 110; wherein, when the valve assembly 130 makes the oil pressure of the oil chambers of the at least two driving cylinders 110 less than or equal to a set value, the swing mechanism 320 can move relative to the frame 310 so that the lock pin 121 is opposite to the target hole position among the multiple lock pin holes 321, and the first driving member 122 drives the lock pin 121 to be inserted into the target hole position.

[0104] The hydraulic control device 100 of the grader provided in the embodiment of the present application includes multiple driving cylinders 110, a locking pin assembly 120 and a valve assembly 130. Specifically, each driving cylinder 110 is connected to a swing frame mechanism 320 and a working piece 330, so that the working posture of the working piece 330 can be adjusted under the drive of the multiple driving cylinders 110.

[0105] The swing frame mechanism 320 is provided with a plurality of locking pin holes 321, and the locking pin assembly 120 includes a connected locking pin 121 and a first driving member 122. Driven by the first driving member 122, the locking pin 121 can be inserted into or removed from any locking pin hole 321, so that the working member 330 can switch between different working postures by replacing the locking pin hole 321, and thus can operate under different working conditions such as earth leveling, ditch excavation and slope finishing.

[0106] The lockpin hole 321 where the lockpin 121 is currently located is the current hole position, and the lockpin hole 321 to which the lockpin 121 is intended to be switched is the target hole position. When the motor grader 300 wishes to switch its working posture, that is, from the left-ditching working posture to the left-slope working posture, the lockpin 121 must be moved out of the current hole position. The swing mechanism 320 then moves relative to the frame 310 so that the lockpin hole 321 corresponding to the left-slope is aligned with the lockpin 121. After alignment, the first drive member 122 drives the lockpin 121 into the lockpin hole 321 corresponding to the left-slope, thereby switching the working posture.

[0107] However, when the locking pin 121 is pulled out from the current hole position, due to the motion coupling between the swing frame mechanism 320 and the workpiece 330, the swing frame mechanism 320 has motion non-uniqueness when moving relative to the frame 310 to align the target hole position, which increases the difficulty of centering the target hole position, reduces the hole changing efficiency, and there is a risk of centering failure.

[0108] Before the swing mechanism 320 moves relative to the frame 310 to make the locking pin 121 aligned with the target hole position, the oil chambers of at least two driving cylinders 110 are first depressurized through the valve assembly 130. Specifically, the valve assembly 130 connects the oil chambers of at least two driving cylinders 110 with the oil return ports of the oil source, respectively. When the oil pressures of the oil chambers of at least two driving cylinders 110 are less than or equal to a set value, the oil pressures of the oil chambers of at least two driving cylinders 110 are the standby oil pressures.

[0109] Alternatively, the valve assembly 130 connects the oil chambers of at least two driving cylinders 110 to the external oil tank respectively. When the oil pressure of the oil chambers of at least two driving cylinders 110 is less than or equal to the set value, the oil pressure of the oil chambers of at least two driving cylinders 110 may be 0.

[0110] Before the swing mechanism 320 moves relative to the frame 310, the valve assembly 130 releases the pressure in at least two driving cylinders 110, so that the working piece 330 falls to the ground under the action of its own gravity and is fixed to the ground by its own gravity, thereby realizing the movement separation between the swing mechanism 320 and the working piece 330. When the swing mechanism 320 moves relative to the frame 310 to align the target hole position, it has movement uniqueness, thereby realizing accurate alignment between the locking pin 121 and the target hole position, reducing the difficulty of centering the locking pin 121 and the target hole position, and improving the hole changing efficiency.

[0111] Optionally, the plurality of driving cylinders 110 include a first lifting cylinder 111, a second lifting cylinder 112, and a swing cylinder 113. Optionally, the set value is 1 MPa or 2 MPa. Optionally, the working member 330 includes a blade. Optionally, the first driving member 122 is a hydraulic cylinder. Specifically, when the first driving member 122 is a hydraulic cylinder, the grader 300 further includes a control valve 190, which is connected to the hydraulic cylinder and is used to control the conduction between the rod chamber and the rodless chamber of the hydraulic cylinder and the oil outlet and return port of the oil source, thereby driving the lock pin 121 to be inserted into or removed from the lock pin hole 321.

[0112] Optionally, as shown in FIG9 , the plurality of locking pin holes 321 include a middle locking pin hole, a right 1 locking pin hole, a right 2 locking pin hole, a left 1 locking pin hole, and a left 2 locking pin hole. When the locking pin is inserted into the middle locking pin hole, the leveling operation requirement of the motor grader is met; when the locking pin is inserted into the right 1 locking pin hole, the left trenching operation requirement of the motor grader is met; when the locking pin is inserted into the right 2 locking pin hole, the left slope operation requirement of the motor grader is met; when the locking pin is inserted into the left 1 locking pin hole, the right trenching operation requirement of the motor grader is met; and when the locking pin is inserted into the left 2 locking pin hole, the right slope operation requirement of the motor grader is met.

[0113] As shown in Figures 7, 8, 9 and 10, in some embodiments, the multiple driving cylinders 110 include a first lifting cylinder 111, a second lifting cylinder 112 and a swinging cylinder 113, and the valve assembly 130 includes a first valve group 131. The first valve group 131 can connect the oil chamber of the first lifting cylinder 111 and the oil chamber of the second lifting cylinder 112 to the return oil port of the oil source respectively, so that the oil pressure of the oil chamber of the first lifting cylinder 111 and the oil pressure of the oil chamber of the second lifting cylinder 112 are both less than or equal to the set value; or the first valve group 131 can connect the oil chamber of the first lifting cylinder 111, the oil chamber of the second lifting cylinder 112 and the swinging cylinder 113 to the return oil port of the oil source respectively, so that the oil pressure of the oil chamber of the first lifting cylinder 111, the oil pressure of the oil chamber of the second lifting cylinder 112 and the oil pressure of the oil chamber of the swinging cylinder 113 are both less than or equal to the set value.

[0114] In this embodiment, the valve assembly 130 is defined to include a first valve group 131. Specifically, the plurality of driving cylinders 110 include a first lifting cylinder 111, a second lifting cylinder 112, and a swing cylinder 113. The first lifting cylinder 111 and the second lifting cylinder 112 are used to adjust the height of the working member 330, and the swing cylinder 113 is used to adjust the working member 330 to swing left or right.

[0115] Before the swing mechanism 320 moves relative to the frame 310, the first valve group 131 connects the oil chamber of the first lifting cylinder 111 and the oil chamber of the second lifting cylinder 112 with the return oil port of the oil source to relieve pressure, so that the oil pressure in the oil chamber of the first lifting cylinder 111 and the oil pressure in the oil chamber of the second lifting cylinder 112 are less than or equal to the set value, that is, the first lifting cylinder 111 and the second lifting cylinder 112 are in a floating state. At this time, the working piece 330 falls to the ground under the action of its own gravity and is fixed to the ground by its own gravity, thereby realizing the movement separation between the swing mechanism 320 and the working piece 330. When the swing mechanism 320 moves relative to the frame 310 to align the target hole position, it has movement uniqueness, thereby realizing accurate alignment between the locking pin 121 and the target hole position, reducing the difficulty of centering the locking pin 121 and the target hole position, and improving the hole changing efficiency.

[0116] When the first lifting cylinder 111 and the second lifting cylinder 112 are in a floating state, the swing cylinder 113 is used as a power source to drive the swing frame mechanism 320 to move relative to the frame 310, so as to align the locking pin 121 with the target hole position, which is convenient for control and does not require an additional power source to drive the swing frame mechanism 320, thereby reducing the production cost of the grader 300.

[0117] Alternatively, before the swing mechanism 320 moves relative to the frame 310, the first valve group 131 connects the oil chamber of the first lifting cylinder 111, the oil chamber of the second lifting cylinder 112, and the oil chamber of the swing cylinder 113 to the oil return port of the oil source to relieve pressure, so that the oil pressure of the oil chamber of the first lifting cylinder 111, the oil pressure of the oil chamber of the second lifting cylinder 112, and the oil pressure of the oil chamber of the swing cylinder 113 are all less than or equal to the set value, that is, the first lifting cylinder 111, the second lifting cylinder 112, and the oil pressure of the oil chamber of the swing cylinder 113 are all less than or equal to the set value. 12 and the swing cylinder 113 are both in a floating state. At this time, the working piece 330 falls to the ground under the action of its own gravity and is fixed to the ground by its own gravity, thereby realizing the movement separation between the swing frame mechanism 320 and the working piece 330. When the swing frame mechanism 320 moves relative to the frame 310 to align the target hole position, it has movement uniqueness, thereby realizing accurate alignment between the locking pin 121 and the target hole position, reducing the difficulty of centering the locking pin 121 and the target hole position, and improving the hole changing efficiency.

[0118] After the swing mechanism 320 and the workpiece 330 are separated, at least one of the first lifting cylinder 111, the second lifting cylinder 112, and the swing cylinder 113 can be used as a power source to drive the swing mechanism 320. However, before using it as a power source, it must first exit the floating state, that is, the oil chamber of at least one of the first lifting cylinder 111, the second lifting cylinder 112, and the swing cylinder 113 must be disconnected from the oil return port or an external oil tank.

[0119] For example, the first lifting cylinder 111 is used as a power source. First, the first valve group 131 cuts off the oil chamber of the first lifting cylinder 111 from the oil return port or the external oil tank, that is, stops the pressure relief. Then, the second valve group 132 connects the rodless chamber of the first lifting cylinder 111 to the oil outlet of the oil source, so that the first lifting cylinder 111 drives the swing frame mechanism 320 to move.

[0120] Optionally, the first lifting cylinder 111 includes a cylinder body and a piston rod. The first end of the piston rod is connected to the working piece 330, and the second end of the piston rod is located within the cylinder body. The cylinder body is movably connected to the swing frame mechanism 320 via a fork. When the working piece 330 lands, hydraulic oil is introduced into the rodless chamber, causing the cylinder body to move relative to the piston rod, thereby driving the swing frame mechanism 320. This ensures that when the swing frame mechanism 320 and the working piece 330 are separated in motion, the first lifting cylinder 111 drives the swing frame mechanism 320 to move, thereby aligning the locking pin 121 with the target hole.

[0121] As shown in Figures 7, 8, 9 and 10, in some embodiments, the valve assembly 130 further includes a second valve group 132, which can connect the oil chamber of the first lifting cylinder 111, the oil chamber of the second lifting cylinder 112 and the oil chamber of the swing cylinder 113 to the oil outlet of the oil source, so as to drive the swing frame mechanism 320 to move relative to the frame 310 when the valve assembly 130 makes the oil pressure of the oil chambers of at least two driving cylinders 110 less than or equal to a set value; or the hydraulic control device 100 of the grader further includes a second drive member, which is connected to the swing frame mechanism 320, and can drive the swing frame mechanism 320 to move relative to the frame 310 when the valve assembly 130 makes the oil pressure of the oil chambers of at least two driving cylinders 110 less than or equal to a set value.

[0122] In this embodiment, the valve assembly 130 further includes a second valve group 132. Specifically, the second valve group 132 connects the oil chambers of the first lift cylinder 111, the second lift cylinder 112, and the swing cylinder 113 to the oil outlet of the oil source. When the valve assembly 130 sets the oil pressure in the oil chambers of at least two drive cylinders 110 to less than or equal to a set value, the swing mechanism 320 is driven to move relative to the frame 310. In other words, at least one of the first lift cylinder 111, the second lift cylinder 112, and the swing cylinder 113 serves as the power source for the swing mechanism 320. This utilizes the inherent structure of the motor grader 300 as the power source, eliminating the need for a separate power source to drive the swing mechanism 320 and reducing the production cost of the motor grader 300.

[0123] For example, the first lifting cylinder 111, the second lifting cylinder 112 and the swing cylinder 113 are all in a floating state, the working part 330 falls to the ground, and the first lifting cylinder 111 is used as a power source. First, the first valve group 131 cuts off the oil chamber of the first lifting cylinder 111 from the return oil port or the external oil tank, that is, stops pressure relief and exits the floating state. Then, the second valve group 132 connects the rodless chamber of the first lifting cylinder 111 to the oil outlet of the oil source, so that the first lifting cylinder 111 drives the swing frame mechanism 320 to move.

[0124] For example, the first lifting cylinder 111 and the second lifting cylinder 112 are in a floating state, the workpiece 330 falls to the ground, and the swing cylinder 113 is used as a power source to drive the swing frame mechanism 320 to move relative to the frame 310, so as to align the locking pin 121 with the target hole position, which is convenient for control and does not require an additional power source to drive the swing frame mechanism 320, thereby reducing the production cost of the grader 300.

[0125] Optionally, if the first lifting cylinder 111 and the swing cylinder 113 are simultaneously used as the power source for driving the swing frame mechanism 320 to move, the first lifting cylinder 111 needs to be exited from the floating state first.

[0126] Alternatively, the hydraulic control device 100 of the grader also includes a second driving member. Specifically, after the swing frame mechanism 320 is separated from the working member 330, the swing frame mechanism 320 is driven to move relative to the frame 310 by the second driving member, that is, a second driving member is additionally provided as a power source for driving the swing frame mechanism 320 to move so as to align the locking pin 121 with the target hole position.

[0127] Before driving the swing mechanism to move, the first lifting cylinder 111, the second lifting cylinder 112 and the swing cylinder 113 can all be placed in a floating state, so that when the swing frame mechanism 320 moves, the working part 330 can be completely separated from the movement of the swing frame mechanism 320, simplifying the driving method, further realizing accurate alignment of the locking pin 121 with the target hole position, and improving the hole changing efficiency.

[0128] Optionally, the second drive member includes a hydraulic cylinder. Optionally, the second valve group 132 controls the connection or disconnection between the rod and rodless chambers of the first lifting cylinder 111, the second lifting cylinder 112, and the swing cylinder 113 and the hydraulic oil tank (return port) and the pressure oil source (oil outlet), respectively, to achieve extension, retraction, and locking of the cylinders, thereby controlling the posture of the working member 330.

[0129] As shown in Figures 7 and 8, in some embodiments, the hydraulic control device 100 of the grader further includes a first detection member 140, which is provided on the swing frame mechanism 320 and is used to detect the swing angle of the swing frame mechanism 320; wherein, when the swing angle is equal to the set angle, the locking pin 121 is opposite to the target hole position corresponding to the set angle.

[0130] In this embodiment, the hydraulic control device 100 of the motor grader further includes a first detection member 140 . Specifically, the first detection member 140 is disposed on the swing frame mechanism 320 , and the first detection member 140 is used to detect the swing angle of the swing frame mechanism 320 .

[0131] When each locking pin hole 321 is opposite to the locking pin 121 , the swing mechanism 320 has a corresponding swing angle. That is, the swing angle of the swing mechanism 320 and the locking pin hole 321 have a one-to-one correspondence.

[0132] Therefore, during the movement of the swing mechanism relative to the frame 310 to align the locking pin 121 with the target hole position, the first detection member 140 detects the swing angle of the swing mechanism 320 in real time. When the detected swing angle is consistent with the swing angle corresponding to the target hole position, it is determined that the locking pin 121 is aligned with the target hole position. At this time, the first driving member 122 is controlled to drive the locking pin 121 into the target hole position, achieving accurate alignment of the locking pin 121 with the target hole position. Compared with the related art, which compares the real-time displacement of the cylinder with the pre-calibrated cylinder displacement data for judgment, this method reduces calibration work, simplifies the control process, improves hole-changing efficiency, achieves full working condition coverage, and reduces the risk of alignment failure.

[0133] Optionally, the swing mechanism 320 includes a first swing arm 322, a second swing arm 323, and a third swing arm 324. Specifically, one end of the first swing arm 322 and one end of the second swing arm 323 are respectively connected to the frame 310 via a kinematic pair, i.e., a movable connection. The two ends of the third swing arm 324 are respectively connected to the other end of the first swing arm 322 and the other end of the second swing arm 323 via a kinematic pair, i.e., a movable connection. In other words, the swing mechanism 320 is a quadrilateral linkage mechanism, and the third swing arm 324 is provided with a plurality of locking pin holes 321.

[0134] The first detection member 140 detects in real time the swing angle of the first swing arm 322 or the second swing arm 323 relative to the frame 310. Alternatively, the first detection member 140 detects in real time the swing angle of the first swing arm 322 or the second swing arm 323 relative to the third swing arm 324. Alternatively, the first detection member 140 detects in real time the swing angle of the first swing arm 322 or the second swing arm 323 relative to the frame 310, and detects in real time the swing angle of the first swing arm 322 or the second swing arm 323 relative to the third swing arm 324.

[0135] That is, the first detection member 140 can be disposed at the connection between the first swing arm 322 and the frame 310, the connection between the second swing arm 323 and the frame 310, the connection between the first swing arm 322 and the third swing arm 324, or the connection between the second swing arm 323 and the third swing arm 324. Specific arrangements can be made based on actual needs. Optionally, the first detection member 140 includes an angle sensor.

[0136] As shown in Figures 7 and 8, in some embodiments, the hydraulic control device 100 of the grader further includes a second detection member 150 and a third detection member 160, wherein the second detection member 150 is provided on the locking pin assembly 120 for detecting whether the locking pin 121 is inserted into or removed from the locking pin hole 321, and the third detection member 160 is used to detect the vehicle speed of the grader 300.

[0137] In this embodiment, the hydraulic control device 100 for a motor grader further includes a second detection member 150 and a third detection member 160. Specifically, the second detection member 150 is disposed on the lock pin assembly 120 and is capable of detecting whether the lock pin 121 is inserted into or removed from the lock pin hole 321. This ensures smooth operation of the motor grader 300 by detecting whether the lock pin 121 is inserted or removed. The third detection member 160 is used to detect the speed of the motor grader 300. Automatic hole resetting of the lock pin 121 is performed only when the speed reaches zero, ensuring driving safety.

[0138] Optionally, if the first driving member 122 includes a hydraulic cylinder, the second detecting member 150 is integrated into the hydraulic cylinder to detect the displacement of the piston rod of the hydraulic cylinder to identify whether the lock pin 121 is inserted or removed. Optionally, the second detecting member 150 includes a displacement sensor or other sensor such as a proximity switch. Optionally, the third detecting member 160 includes a vehicle speed sensor.

[0139] As shown in Figures 7 and 8, in some embodiments, the hydraulic control device further includes a display device 170 and a switch element 180, wherein the display device 170 is electrically connected to the valve assembly 130, and the switch element 180 is connected to the display device 170, and the switch element 180 is used to control whether the display device 170 starts working.

[0140] In this embodiment, it is defined that the hydraulic control device also includes a display device 170 and a switch element 180. Specifically, the display device 170 is electrically connected to the valve assembly 130, that is, the display device 170 is an intelligent display screen 172, which integrates the human-computer interaction function of the display and the control function of the controller 171.

[0141] The display device 170 can display the current hole position of the locking pin 121, and can also set the target hole position on the display device 170. The switch component 180 is connected to the display device 170. Specifically, the switch component 180 can control whether the display device 170 is started to work, thereby ensuring that the grader 300 changes the hole when it is parked, that is, preventing the hole from being changed while driving due to accidental touching of the display device 170, thereby ensuring safety. Optionally, the switch component 180 is a manual switch. Optionally, the switch component 180 is an enabling switch. The locking pin 121 can only be changed in the hole if the control switch component 180 is in the open state. Optionally, the switch component 180 includes a rocker switch or a silicone button, etc.

[0142] As shown in Figure 7, in some embodiments, when the hydraulic control device includes a display device 170 and a switch element 180, the display device 170 includes a controller 171 and a display screen 172, wherein the controller 171 is electrically connected to the valve assembly 130, the switch element 180 is connected to the controller 171 for controlling whether the controller 171 starts working, and the display screen 172 is electrically connected to the controller 171.

[0143] In this embodiment, the display device 170 is defined as comprising a controller 171 and a display screen 172. Specifically, the controller 171 is electrically connected to the valve assembly 130, and the display screen 172 is electrically connected to the controller 171. The display screen 172 can display the current hole position of the locking pin 121 and can also be used to set a target hole position on the display device 170, thereby implementing human-computer interaction. A switch 180 is connected to the controller 171. Specifically, the switch 180 can control whether the controller 171 is activated, thereby ensuring that the grader 300 can change the hole position while parked. This prevents accidental touches on the display screen 172 while the grader 300 is in motion, thereby ensuring safety.

[0144] According to the third aspect of the present application, a grader 300 is provided, comprising the hydraulic control device 100 for the grader provided in any of the above embodiments, and thus possessing all the beneficial technical effects of the hydraulic control device 100 for the grader, which will not be elaborated here.

[0145] 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.

[0146] 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.

[0147] 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 method for a grader, wherein: The grader includes a frame, a swing frame mechanism, a working piece, a plurality of driving cylinders and a lock pin assembly, wherein the swing frame mechanism is movably arranged on the frame, each of the driving cylinders is connected to the swing frame mechanism and the working piece, the swing frame mechanism is provided with a plurality of lock pin holes, the lock pin assembly includes a first driving piece and a lock pin connected to each other, 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 first driving piece, and the hydraulic control method includes: Controlling the pressure relief of the oil chambers of at least two of the driving oil cylinders; When the oil pressure of the oil chambers of at least two of the driving oil cylinders is less than or equal to a set value, the swing frame mechanism is controlled to move relative to the frame so that the lock pin is aligned with a target hole position among the plurality of lock pin holes; The first driving member is controlled to drive the locking pin to insert into the target hole.

2. The hydraulic control method for a motor grader according to claim 1, wherein: The plurality of driving cylinders include a first lifting cylinder, a second lifting cylinder and a swing cylinder, and the control of depressurizing the oil chambers of at least two of the driving cylinders specifically includes: Controlling the oil chamber of the first lifting cylinder and the oil chamber of the second lifting cylinder to release pressure; or The oil chamber of the first lifting cylinder, the oil chamber of the second lifting cylinder and the oil chamber of the swing cylinder are controlled to release pressure.

3. The hydraulic control method of a motor grader according to claim 2, wherein: Before the control is performed to release the pressure of the oil chambers of at least two of the driving oil cylinders, the method further includes: According to the positional relationship between the current hole position where the locking pin is located and the target hole position, the piston rod of the swing cylinder is controlled to extend or retract to a preset length.

4. The hydraulic control method for a motor grader according to claim 3, wherein: The controlling the piston rod of the swing cylinder to extend or retract a preset length according to the positional relationship between the current hole position where the lock pin is located and the target hole position specifically includes: Determining whether the target hole position is located on a first side of the current hole position; When the target hole position is located at the first side of the current hole position, controlling the piston rod of the swing cylinder to extend to the preset length; When the target hole position is not located at the first side of the current hole position, the piston rod of the swing cylinder is controlled to retract to the preset length.

5. The hydraulic control method for a motor grader according to any one of claims 1 to 4, wherein: The controlling the swing mechanism to move relative to the frame specifically includes: Control at least one of the driving cylinders to stop releasing pressure, and control at least one of the driving cylinders that stops releasing pressure to drive the swing frame mechanism to move relative to the frame; or Control the remaining driving cylinders among the plurality of driving cylinders to drive the swing frame mechanism to move relative to the frame; or The second driving member of the motor grader is controlled to drive the swing frame mechanism to move relative to the frame.

6. The hydraulic control method for a motor grader according to any one of claims 1 to 4, wherein: After the control is performed to release the pressure of the oil chambers of at least two of the driving oil cylinders, the method further comprises: When the oil pressure of the oil chambers of at least two of the driving oil cylinders is less than or equal to the set value, the first driving member is controlled to drive the locking pin to move out of a current hole position of the plurality of locking pin holes.

7. The hydraulic control method for a motor grader according to any one of claims 1 to 4, wherein: The controlling the swing mechanism to move relative to the frame so that the locking pin is aligned with a target hole position in the plurality of locking pin holes specifically includes: Detecting the swing angle of the swing frame mechanism; When the swing angle is equal to the set angle, it is determined that the locking pin is opposite to the target hole position corresponding to the set angle.

8. The hydraulic control method for a motor grader according to any one of claims 1 to 4, wherein: The controlling the first driving member to drive the locking pin to insert into the target hole specifically includes: When the number of lock pin holes N between the current hole position where the lock pin is located and the target hole position is greater than the maximum number of lock pin holes n that the swing frame mechanism can move each time, the number of hole changes is determined according to the number of lock pin holes N and the number of lock pin holes n, and the number of hole changes d=ROUNDUP[(N+1) / n]; The first driving member is controlled to drive the locking pin to move according to the hole-changing times, so that the locking pin is inserted into the target hole position.

9. A hydraulic control device for a grader, wherein: The grader comprises a frame, a swing frame mechanism and a working piece, wherein the swing frame mechanism is movably arranged on the frame, and the swing frame mechanism is provided with a plurality of locking pin holes, and the hydraulic control device comprises: A plurality of driving cylinders, each of which is connected to the swing frame mechanism and the working piece; A locking pin assembly, the locking pin assembly comprising a first driving member and a locking pin connected to each other, the locking pin being configured to be inserted into or removed from any of the plurality of locking pin holes under the drive of the first driving member; A valve assembly connected to at least two of the plurality of driving cylinders; Wherein, when the valve assembly makes the oil pressure in the oil chambers of at least two of the driving cylinders less than or equal to a set value, the swing frame mechanism can move relative to the frame so that the locking pin is opposite to a target hole position among the multiple locking pin holes, and the first driving member drives the locking pin to insert into the target hole position.

10. The hydraulic control device for a motor grader according to claim 9, wherein: The plurality of driving cylinders include a first lifting cylinder, a second lifting cylinder and a swing cylinder, and the valve assembly includes: a first valve group, wherein the first valve group can connect the oil chamber of the first lifting cylinder and the oil chamber of the second lifting cylinder to the oil return port of the oil source respectively, so that the oil pressure of the oil chamber of the first lifting cylinder and the oil pressure of the oil chamber of the second lifting cylinder are both less than or equal to the set value; or The first valve group can connect the oil chamber of the first lifting cylinder, the oil chamber of the second lifting cylinder and the oil chamber of the swing cylinder to the oil return port of the oil source respectively, so that the oil pressure of the oil chamber of the first lifting cylinder, the oil pressure of the oil chamber of the second lifting cylinder and the oil pressure of the oil chamber of the swing cylinder are all less than or equal to the set value.

11. The hydraulic control device for a motor grader according to claim 10, wherein: The valve assembly further comprises a second valve group, which is capable of connecting at least one of the oil chambers of the first lifting cylinder, the second lifting cylinder and the swing cylinder to an oil outlet of an oil source, so as to drive the swing frame mechanism to move relative to the frame when the valve assembly makes the oil pressure of the oil chambers of at least two driving cylinders less than or equal to the set value; or The hydraulic control device of the grader also includes a second driving member, which is connected to the swing frame mechanism. When the valve assembly makes the oil pressure in the oil chambers of at least two of the driving cylinders less than or equal to the set value, the second driving member can drive the swing frame mechanism to move relative to the frame.

12. The hydraulic control device for a motor grader according to any one of claims 9 to 11, wherein: The hydraulic control device of the grader also includes: A first detection member is provided on the swing frame mechanism and is used to detect a swing angle of the swing frame mechanism. When the swing angle is equal to a set angle, the locking pin is opposite to the target hole position corresponding to the set angle; and / or a second detection member, provided on the lock pin assembly, for detecting whether the lock pin is inserted into or removed from the lock pin hole; and / or a third detection member, used for detecting the speed of the grader; and / or A display device and a switch component, wherein the display device is electrically connected to the valve assembly, and the switch component is connected to the display device, and the switch component is used to control whether the display device starts working.

13. A motor grader, wherein: A hydraulic control device for a motor grader comprising any one of claims 9 to 12.

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