A closed hydraulic walking system control device and method

Abstract

The application discloses a closed hydraulic walking system control device and method, and relates to the technical field of hydraulic control. The control device comprises a closed pump, at least two pairs of left and right wheel driving assemblies, a switching valve group, a closed pump oil outlet pipeline and a closed pump oil return pipeline. Each wheel driving assembly is connected with a wheel, and the wheel driving assembly has a wheel driving assembly oil circuit. The switching valve group is suitable for connecting the wheel driving assembly oil circuits on the same side in series, connecting the wheel driving assembly oil circuits on the left and right sides in parallel after series connection, and connecting the closed pump oil outlet pipeline and the closed pump oil return pipeline to form a closed loop. The application connects the wheel driving assembly oil circuits on the same side in series through the switching valve group, connects the closed pump to form a closed loop, can effectively reduce the flow of oil in the closed loop under the same speed requirement, can effectively reduce the displacement of the closed pump, and can reduce the volume and cost of the closed pump.

Description

Technical Field

[0001] This invention relates to the field of hydraulic control technology, specifically to a closed-loop hydraulic walking system control device and method. Background Technology

[0002] This section provides only background information relevant to this disclosure and does not necessarily constitute prior art.

[0003] Existing hydraulic drive systems typically employ a fully hydraulic proportional control, four-wheel drive configuration. The hydraulic pump is connected to four motors controlling wheel rotation via oil supply lines. These four motors are connected in parallel to the hydraulic pump, and the hydraulic fluid output from the pump's outlet lines is distributed to the respective motor circuits. Since the motors, as the components driving wheel rotation, have an input oil flow rate directly proportional to their rotational speed, the parallel connection of the four motors results in each motor receiving approximately one-quarter of the hydraulic pump's output oil flow. Therefore, when a specific motor speed is required, the hydraulic pump's output oil flow rate is relatively high.

[0004] The relationship between hydraulic pump displacement and flow rate is: Flow rate = Displacement × Rotation speed. Therefore, when the hydraulic pump output flow rate is large, with the pump rotation speed remaining constant, the hydraulic pump displacement needs to be increased. Increasing the displacement of the hydraulic pump will increase its size. However, the installation space for hydraulic travel systems is limited, and there is a problem where the original assembly cannot be arranged due to space constraints. Furthermore, using a hydraulic pump with a larger displacement will increase the manufacturing cost of the hydraulic travel system. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the four motors of the existing hydraulic walking system are connected to the hydraulic oil pump in parallel, which makes it impossible to arrange the original assembly due to the limited space. Thus, a closed hydraulic walking system control device and method are provided.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A closed-loop hydraulic walking system control device, comprising:

[0008] Closed-loop pump;

[0009] At least two pairs of wheel drive assemblies, the wheel drive assemblies being connected to wheels, the wheel drive assemblies having wheel drive assembly oil passages suitable for controlling wheel speed and steering;

[0010] The switching valve group is adapted to connect the wheel drive assembly oil lines in series on the same side, connect the wheel drive assembly oil lines in parallel after series connection on both sides, and connect the closed pump to form a closed loop.

[0011] Further optimization of the technical scheme, the closed pump has a closed pump oil outlet pipeline and a closed pump oil return pipeline;

[0012] The switching valve group is connected with the wheel drive assembly oil lines, and is connected with the closed pump oil outlet pipeline and the closed pump oil return pipeline to form a closed loop.

[0013] Further optimization of the technical scheme, the switching valve group includes:

[0014] The oil feeding main pipeline is divided into a first oil feeding pipeline and a second oil feeding pipeline at one end, the first oil feeding pipeline is adapted to connect at least two wheel drive assembly oil lines in series on the right side, the second oil feeding pipeline is adapted to connect at least two wheel drive assembly oil lines in series on the left side, and the other end of the oil feeding main pipeline is connected with the closed pump oil outlet pipeline;

[0015] The oil return main pipeline is connected with the oil return port of the first oil feeding pipeline and the oil return port of the second oil feeding pipeline at one end, and is connected with the closed pump oil return pipeline at the other end.

[0016] Further optimization of the technical scheme, the first oil feeding pipeline includes a first oil inlet pipeline, a first oil outlet pipeline and at least one first transition oil line;

[0017] The first oil inlet pipeline is connected with the oil inlet port of the wheel drive assembly oil line at the last end on the right side;

[0018] The oil return port of the wheel drive assembly oil line on the right side is connected with the oil inlet port of the adjacent wheel drive assembly oil line through the first transition oil line, so as to realize the series connection of the wheel drive assembly oil lines on the right side;

[0019] The oil return port of the wheel drive assembly oil line at the first end on the right side is connected with the oil return main pipeline through the first oil outlet pipeline.

[0020] Further optimization of the technical scheme, the second oil feeding pipeline includes a second oil inlet pipeline, a second oil outlet pipeline and at least one second transition oil line;

[0021] The second oil inlet pipeline is connected with the oil inlet port of the wheel drive assembly oil line at the last end on the left side;

[0022] The oil return port of the wheel drive assembly oil line on the left side is connected with the oil inlet port of the adjacent wheel drive assembly oil line through the second transition oil line, so as to realize the series connection of the wheel drive assembly oil lines on the left side;

[0023] The oil return port of the wheel drive assembly oil circuit at the front left end is connected to the oil return main circuit through a second oil outlet pipeline.

[0024] Further optimization, the first oil supply pipeline and the second oil supply pipeline are provided with a throttle valve, the throttle valve is suitable for balancing the oil flow of the first oil supply pipeline and the second oil supply pipeline;

[0025] And / or the oil supply main circuit and the oil return main circuit are provided with a connecting oil circuit, and a stop valve is arranged on the connecting oil circuit.

[0026] Further optimization, the first oil supply pipeline and the second oil supply pipeline are further provided with an oil supplementing structure, and the oil supplementing structure is suitable for supplementing the oil in the oil tank to the first oil supply pipeline and the second oil supply pipeline.

[0027] Further optimization, the wheel drive assembly comprises:

[0028] A double-speed motor comprising a first motor and a second motor, the first motor and the second motor are coaxially connected with the wheel respectively; the wheel drive assembly oil circuit comprises a first motor oil circuit, a second motor oil circuit and a double-speed motor oil return circuit;

[0029] A double-speed motor high-low speed switching valve, the double-speed motor high-low speed switching valve has a switching valve oil inlet and a switching valve oil return port, and the double-speed motor high-low speed switching valve is suitable for controlling the connection between the first motor oil circuit and / or the second motor oil circuit and the switching valve oil inlet.

[0030] Further optimization, the double-speed motor high-low speed switching valve has a first working position and a second working position, and the first working position and the second working position of the double-speed motor high-low speed switching valve are switched by a switching valve control system;

[0031] The switching valve control system comprises a first oil suction pipeline, an oil suction pump, a high-pressure filter and a second electromagnetic reversing valve, the first oil suction pipeline is connected with the oil tank, the oil suction pump, the high-pressure filter and the second electromagnetic reversing valve are arranged in sequence on the first oil suction pipeline, and the oil outlet of the first oil suction pipeline is connected with the cavity of each double-speed motor high-low speed switching valve respectively;

[0032] The second electromagnetic reversing valve has a second electromagnetic reversing valve one position and a second electromagnetic reversing valve two position; when the second electromagnetic reversing valve is powered, one end of the second electromagnetic reversing valve one position is in communication with the first oil suction pipeline, and the other end of the second electromagnetic reversing valve one position is in communication with the cavity of each double-speed motor high-low speed switching valve respectively; when the second electromagnetic reversing valve loses power, one end of the second electromagnetic reversing valve two position is in communication with the oil discharge pipeline, and the other end of the second electromagnetic reversing valve two position is in communication with the cavity of each double-speed motor high-low speed switching valve respectively.

[0033] Further optimization technical solutions, the control device also includes a release parking brake system, the release parking brake system is suitable for controlling the caliper brake to separate from the brake of the wheel shaft;

[0034] The release parking brake system includes a second oil suction pipeline, a caliper brake, and a first electromagnetic reversing valve; the caliper brake is provided with a plurality of and respectively brakes one wheel shaft; the second oil suction pipeline is respectively communicated with each caliper brake; the first electromagnetic reversing valve has a first electromagnetic reversing valve one position and a first electromagnetic reversing valve two position; when the first electromagnetic reversing valve is powered, one end of the first electromagnetic reversing valve one position is communicated with the first oil suction pipeline, and the other end of the first electromagnetic reversing valve one position is respectively communicated with the second oil suction pipeline; when the first electromagnetic reversing valve loses power, one end of the first electromagnetic reversing valve two position is communicated with the oil discharge pipeline, and the other end of the first electromagnetic reversing valve two position is communicated with the second oil suction pipeline.

[0035] Further optimization technical solutions, the release parking brake system also includes a manual oil supplement pipeline, an oil suction filter, a manual pump and an accumulator, the oil suction filter, the manual pump and the accumulator are sequentially arranged on the manual oil supplement pipeline, one end of the manual oil supplement pipeline is connected with the oil tank, and the other end of the manual oil supplement pipeline is connected with the side of the first oil suction pipeline.

[0036] A closed hydraulic walking system control method, the method is based on the closed hydraulic walking system control device, including the control step of vehicle driving state:

[0037] According to the high and low speed driving state required by the vehicle, the high and low speed switching valve of the double speed motor of each wheel driving assembly is switched to control the work position: when the vehicle needs to drive at low speed, the high and low speed switching valve of the double speed motor of each wheel driving assembly is switched to the first working position, and the oil liquid output by the closed pump flows through the wheel driving assembly, at the same time, it is supplied to the parallel first motor and second motor, the double speed motor is full displacement, and the double speed motor outputs low speed and high torque; when the vehicle needs to drive at high speed, the high and low speed switching valve of the double speed motor of each wheel driving assembly is switched to the second working position, and the oil liquid output by the closed pump flows through the wheel driving assembly, only to supply to the first motor, the double speed motor is half displacement, and the double speed motor outputs high speed and low torque;

[0038] And / or when the left and right sides of the vehicle need to drive differentially, the oil flow of the oil circuit of the left side series connected wheel driving assembly and the oil flow of the oil circuit of the right side series connected wheel driving assembly are adjusted to different states, so that the rotation speeds of the double speed motors on the left and right sides are different.

[0039] Further optimization technical solutions, also including the control step of the release parking state:

[0040] The oil in the oil tank is automatically or manually controlled to be delivered to each caliper brake, so that the caliper brake is switched to a work station, and the caliper brake is controlled to be separated from the brake of the wheel shaft.

[0041] The technical scheme of the present application has the following advantages:

[0042] 1. The closed hydraulic walking system control device provided by the present application connects the oil paths of the same side wheel driving assemblies in series through the adapter valve group, and then connects the closed pump to form a closed loop, so that the oil flow of each wheel driving assembly oil path is half of the oil flow output by the closed pump oil outlet pipeline, and then when the wheel driving assembly drives the wheel to reach the same speed requirement, the oil flow output by the closed pump oil outlet pipeline is reduced by half compared with the existing hydraulic walking system, that is, the displacement of the closed pump can be effectively reduced; compared with the parallel connection mode of the four wheel driving assemblies and the closed pump, the displacement of the closed pump in the present application can be halved, thereby reducing the volume and cost of the closed pump, which is beneficial to the arrangement and cost control of small equipment.

[0043] 2. The closed hydraulic walking system control device provided by the present application further comprises an oil supplementing structure between the first oil feeding pipeline and the second oil feeding pipeline, so that when the flow of the closed loop is insufficient due to pipeline and motor leakage, the first one-way valve of the adapter valve group absorbs oil from the oil tank to achieve the effect of oil supplementing. At the same time, the oil supplementing effect of the adapter valve group can avoid the suction phenomenon caused by insufficient hydraulic oil flow of the connected motor, and the adapter valve group has the oil supplementing function in addition to the series connection of the motor oil path.

[0044] 3. The closed hydraulic walking system control device provided by the present application adopts a hydraulic control mode for the high-low speed switching valve of the double-speed motor, so that the switching of the working position of the high-low speed switching valve of the double-speed motor can be effectively controlled by the on-off control of the second electromagnetic reversing valve, and then the switching of the high-speed mode and the low-speed mode of the vehicle can be realized, which is very convenient.

[0045] 4. The closed hydraulic walking system control device provided by the present application comprises a first electromagnetic reversing valve, and the second oil suction pipeline is communicated with the first oil suction pipeline when the first electromagnetic reversing valve is powered on. The oil output from the oil suction pump passes through the high-pressure filter, the second one-way valve, and then the oil port of the first electromagnetic reversing valve to form a pilot oil, so as to supply oil to the caliper brake of each double-speed motor and release the parking brake. The parking brake release system and the switching valve control system are arranged on the first oil suction pipeline, so that the same oil suction pump can be directly used to realize the control of the two modes.

[0046] 5. The closed hydraulic walking system control device provided by the present application, wherein the oil suction filter, the manual pump and the energy accumulator are sequentially arranged on the manual oil supplement pipeline, one end of the manual oil supplement pipeline is connected with the oil tank, and the other end of the manual oil supplement pipeline is connected with the side of the first oil suction pipeline, so that the manual pump can manually release the parking brake in the engine failure state. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the specific embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0048] Figure 1 The hydraulic principle diagram of the closed hydraulic walking system control device provided by the present application when the vehicle is running at low speed;

[0049] Figure 2 The hydraulic principle diagram of the closed hydraulic walking system control device provided by the present application when the vehicle is running at high speed.

[0050] LIST OF REFERENCE NUMERALS

[0051] 1, right front wheel double-speed motor, 11, right front wheel double-speed motor high-low speed switching valve, 12, right front wheel caliper brake, 2, right rear wheel double-speed motor, 21, right rear wheel double-speed motor high-low speed switching valve, 22, right rear wheel caliper brake, 3, left front wheel double-speed motor, 31, left front wheel double-speed motor high-low speed switching valve, 32, left front wheel caliper brake, 4, left rear wheel double-speed motor, 41, left rear wheel double-speed motor high-low speed switching valve, 42, left rear wheel caliper brake, 5, switching valve group, 51, first check valve, 52, throttle valve, 53, oil feeding main pipeline, 54, first oil feeding pipeline, 55, second oil feeding pipeline, 56, oil return main pipeline, 6, first electromagnetic directional valve, 7, second electromagnetic directional valve, 8, second check valve, 9, high-pressure filter, 10, energy accumulator, 13, oil tank, 14, closed pump, 141, oil suction pump, 142, flushing valve, 143, oil suction pump safety valve, 144, first walking safety valve, 145, second walking safety valve, 146, proportional electromagnetic valve, 147, closed pump oil outlet pipeline, 148, closed pump oil return pipeline, 15, stop valve, 16, manual pump, 17, oil suction filter. DETAILED DESCRIPTION

[0052] Exemplary embodiments of the present disclosure will be described in greater detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure can be more thoroughly understood, and so that the scope of the present disclosure can be completely conveyed to those skilled in the art. It should be noted that the present application is described by connecting the motor oil circuit through the switching valve group to realize the series connection and oil supplement function, and the closed hydraulic walking system control device is only a preferred embodiment, and is not a limitation on the protection scope of the closed hydraulic walking system control device.

[0053] It should be noted that "parking brake" means locking the transmission shaft or the wheel; "releasing parking brake" means canceling or releasing the parking brake on the vehicle, so that the vehicle can move freely without being fixed by the brake.

[0054] The existing hydraulic walking system often adopts the form of full hydraulic proportional control and four-wheel drive. The hydraulic oil pump needs to be connected with four motors for controlling the rotation of the wheels through oil supply pipelines respectively, the four motors are connected with the hydraulic oil pump in parallel, and the oil output by the oil outlet pipeline of the hydraulic oil pump is respectively divided into four motor oil circuits. Since the input oil flow of the motor is proportional to the rotation speed, the four motors are connected with the hydraulic oil pump in parallel, so that the input oil flow of each motor accounts for one quarter of the oil flow in the oil outlet pipeline of the hydraulic oil pump. Therefore, when the motor needs to reach a certain rotation speed, the oil flow output by the hydraulic oil pump is large.

[0055] The relationship between the displacement and the flow of the hydraulic oil pump is: flow = displacement x rotation speed. Therefore, when the flow output by the hydraulic oil pump is large, the displacement of the hydraulic oil pump needs to be increased under the condition that the rotation speed of the hydraulic oil pump is unchanged, and the increase of the displacement of the hydraulic oil pump will increase the volume of the hydraulic oil pump. Since the installation position of the hydraulic walking system has limited space, there is a problem that the original assembly cannot be arranged due to the small space.

[0056] Based on this, the present application provides a closed hydraulic walking system control device, which can reduce the volume of components as much as possible to complete the arrangement and reduce the cost under the premise of meeting the normal demand of walking.

[0057] The specific embodiments of the present application will be described in detail below in combination with the closed hydraulic walking system control device of the first aspect of the present application.

[0058] It should be noted that the closed hydraulic walking system control device of the first aspect of the present application is only a preferred embodiment of the present application, and the closed hydraulic walking system control device of the present application can adopt the closed hydraulic walking system control device of the first aspect of the present application or other structures. In order to facilitate the description, the closed hydraulic walking system control device of the first aspect of the present application is described below.

[0059] In combination Figures 1 to 2 As shown in the embodiment, the closed hydraulic walking system control device comprises a closed pump 14, a wheel driving assembly and a switching valve group 5. The closed pump 14 has a closed pump oil outlet pipeline 147 and a closed pump oil return pipeline 148. The wheel driving assembly is provided with at least two pairs, and each two wheel driving assemblies are located on the left and right sides. Each wheel driving assembly is connected with a wheel, and the wheel driving assembly has a wheel driving assembly oil circuit suitable for controlling the wheel speed and steering. The switching valve group 5 is suitable for connecting the wheel driving assembly oil circuits on the same side in series, connecting the wheel driving assembly oil circuits on the left and right sides in parallel after series connection, and connecting the closed pump oil outlet pipeline 147 and the closed pump oil return pipeline 148 to form a closed loop.

[0060] Under the same speed requirement, the parallel connection of the wheel driving assembly oil circuit requires more oil flow than the series connection, so that the required displacement of the closed pump 14 is larger, resulting in a larger volume of the closed pump 14. Therefore, in the embodiment, the wheel driving assembly oil circuits on the same side of the vehicle are connected in series through the switching valve group 5, and then connected with the closed pump 14 to form a closed loop. When the wheel driving assembly oil circuits on the same side of the vehicle are connected in series, the shunt effect of the wheel driving assembly oil circuits on the same side of the vehicle is cancelled, so that the oil flow of each wheel driving assembly oil circuit is half of the output oil flow of the closed pump oil outlet pipeline 147. Therefore, under the same speed requirement, the wheel driving assembly drives the wheel, and the output oil flow of the closed pump oil outlet pipeline 147 is reduced by half compared with the existing hydraulic walking system, that is, the displacement of the closed pump 14 (hydraulic oil pump) can be effectively reduced. Therefore, compared with the parallel connection of the plurality of wheel driving assemblies and the closed pump 14, the displacement of the closed pump 14 can be reduced by half, thereby reducing the volume and cost of the closed pump 14, which is beneficial to the arrangement and cost control of small equipment.

[0061] It should be noted that in the embodiment, the wheel driving assembly is provided with at least two pairs, so the application scope of the embodiment includes but is not limited to four-wheel drive vehicles, and can also be applied to other types of vehicles, such as six-wheel drive vehicles.

[0062] In some embodiments, the closed pump 14 is provided with a proportional electromagnetic valve 146, which is adapted to control the direction and displacement of the closed pump 14, affecting the forward and reverse state of the vehicle. The closed pump 14 is also provided with a first travel safety valve 144, a second travel safety valve 145, a flushing valve 142, an oil suction pump safety valve 143 and the like.

[0063] In some embodiments, the wheel drive assembly includes a double-speed motor and a double-speed motor high-low speed switching valve. The double-speed motor includes a first motor and a second motor, which are coaxially connected with the wheels, respectively. The wheel drive assembly oil circuit includes a first motor oil circuit, a second motor oil circuit and a double-speed motor oil return circuit. The double-speed motor high-low speed switching valve has a switching valve oil inlet and a switching valve oil return, and is adapted to control the connection of the first motor oil circuit and / or the second motor oil circuit with the switching valve oil inlet.

[0064] In the present embodiment, the double-speed motor high-low speed switching valve has a switching valve one position and a switching valve two position. When the vehicle is in low-speed driving mode, the double-speed motor high-low speed switching valve is in the switching valve one position, at which time the switching valve oil inlet is in communication with the first motor oil circuit and the second motor oil circuit, respectively, the first motor oil circuit and the second motor oil circuit are connected in parallel, the double-speed motor is in full displacement, the amount of oil flowing through the first motor oil circuit and the second motor oil circuit is small, the double-speed motor outputs low speed and high torque. The double-speed motor at this time can rotate at low speed, and low speed corresponds to low-speed driving. When the vehicle is in high-speed driving mode, the double-speed motor high-low speed switching valve is in the switching valve two position, at which time the switching valve oil inlet is in communication with the first motor oil circuit, and the switching valve oil inlet is not in communication with the second motor oil circuit, and the oil in the closed loop can flow through the first motor oil circuit; or the first motor oil circuit and the second motor oil circuit are connected in series, and the first motor oil circuit and the second motor oil circuit are connected with the switching valve oil inlet; at this time, the double-speed motor is in half displacement, the motor outputs high speed and low torque. The double-speed motor at this time can rotate at high speed, and high speed corresponds to high-speed driving.

[0065] In some embodiments, the adapter valve group 5 includes an oil feeding main circuit 53 and an oil return main circuit 56. One end of the oil feeding main circuit 53 is divided into a first oil feeding circuit 54 and a second oil feeding circuit 55, the first oil feeding circuit 54 is adapted to connect the at least two wheel drive assembly oil circuits on the right side in series, the second oil feeding circuit 55 is adapted to connect the at least two wheel drive assembly oil circuits on the left side in series, the other end of the oil feeding main circuit 53 is connected with the closed pump oil outlet circuit 147. One end of the oil return main circuit 56 is connected with the oil return port of the first oil feeding circuit 54 and the oil return port of the second oil feeding circuit 55, respectively, the other end of the oil return main circuit 56 is connected with the closed pump oil return circuit 148.

[0066] More specifically, the first oil feeding pipeline 54 includes a first oil feeding pipeline, a first oil outlet pipeline and at least one first transition oil path. The first oil feeding pipeline is connected with the switching valve oil inlet of the high-low speed switching valve at the right end. The switching valve oil return port of the high-low speed switching valve at the right side is connected with the switching valve oil inlet of the high-low speed switching valve adjacent thereto through the first transition oil path, so as to realize the series connection of the oil paths of the wheel driving assemblies at the right side. The switching valve oil return port of the high-low speed switching valve at the left end is connected with the oil return main pipeline 56 through the first oil outlet pipeline.

[0067] The second oil feeding pipeline 55 includes a second oil feeding pipeline, a second oil outlet pipeline and at least one second transition oil path. The second oil feeding pipeline is connected with the switching valve oil inlet of the high-low speed switching valve at the left end. The switching valve oil return port of the high-low speed switching valve at the left side is connected with the switching valve oil inlet of the high-low speed switching valve adjacent thereto through the second transition oil path, so as to realize the series connection of the oil paths of the wheel driving assemblies at the left side. The switching valve oil return port of the high-low speed switching valve at the left end is connected with the oil return main pipeline 56 through the second oil outlet pipeline.

[0068] In the embodiment, the switching valve oil return port of the high-low speed switching valve at the same side is connected with the switching valve oil inlet of the high-low speed switching valve adjacent thereto, so as to realize the series connection of the oil paths of the driving assemblies at the same side. The first oil feeding pipeline 54 and the second oil feeding pipeline 55 are each divided into a plurality of oil paths, which can reduce the length of the oil paths and make the connection of the oil paths more orderly, thereby avoiding the problem of disordered connection of the oil paths. The switching valve group 5 can further include a box body, and the first oil feeding pipeline, the first oil outlet pipeline, the first transition oil path, the second oil feeding pipeline, the second oil outlet pipeline and the second transition oil path are arranged in the box body.

[0069] Since the flow rates of the motors at the left and right sides are basically the same and the instantaneous speeds are basically the same, the vehicle is prone to skidding or overturning at high speed in the case of differential speed during turning. In some embodiments, a throttle valve 52 is arranged between the first oil feeding pipeline 54 and the second oil feeding pipeline 55, and the throttle valve 52 is adapted to balance the flow rates of the oil in the first oil feeding pipeline 54 and the second oil feeding pipeline 55. The control mode of the throttle valve 52 can be electronic, pneumatic or hydraulic, and the opening and closing degree of the valve is automatically adjusted through a feedback signal, the size of the throttle hole is adjusted, the speed of the oil passing through the throttle hole is controlled, and the flow rate is accurately controlled. Then, when the vehicle needs differential speed during turning, the flow rates of the oil in the first oil feeding pipeline 54 and the second oil feeding pipeline 55 can be controlled by adjusting the throttle valve 52, so that the speeds of the motors at the left and right sides are different, thereby avoiding the occurrence of skidding or overturning of the vehicle.

[0070] In some embodiments, a connecting oil line is arranged between the oil feeding main line 53 and the oil return main line 56, and a stop valve 15 is arranged on the connecting oil line.

[0071] In some embodiments, a supplementary oil structure is further arranged between the first oil feeding line 54 and the second oil feeding line 55, and the supplementary oil structure is adapted to supply oil in the oil tank 13 to the first oil feeding line 54 and the second oil feeding line 55. When the flow in the closed circuit is insufficient due to leakage in the lines and the motors, the first one-way valve 51 of the adapter valve group 5 absorbs oil from the oil tank 13, achieving the effect of supplementing oil. At the same time, the motors in series can avoid the phenomenon of insufficient hydraulic oil flow by the effect of supplementing oil of the adapter valve group 5. In this embodiment, in addition to being able to realize series connection of the motor oil lines, the adapter valve group 5 also has the function of supplementing oil.

[0072] In some embodiments, the high-low speed switching valve of the dual-speed motor has a first working position and a second working position, and the first working position and the second working position of the high-low speed switching valve of the dual-speed motor are switched by a switching valve control system. The switching valve control system includes a first oil suction line, an oil suction pump 141, a high-pressure filter 9, and a second electromagnetic reversing valve 7. The first oil suction line is connected to the oil tank 13, the oil suction pump 141, the high-pressure filter 9, and the second electromagnetic reversing valve 7 are arranged in sequence on the first oil suction line, and the oil outlet of the first oil suction line is connected to the cavities of the high-low speed switching valves of the dual-speed motors through third oil suction lines. The second electromagnetic reversing valve 7 has a second electromagnetic reversing valve one position and a second electromagnetic reversing valve two position; when the second electromagnetic reversing valve 7 is powered, one end of the second electromagnetic reversing valve one position is in communication with the first oil suction line, and the other end of the second electromagnetic reversing valve one position is in communication with the cavities of the high-low speed switching valves of the dual-speed motors through the third oil suction lines; when the second electromagnetic reversing valve 7 is de-energized, one end of the second electromagnetic reversing valve two position is in communication with the oil discharge line, and the other end of the second electromagnetic reversing valve two position is in communication with the cavities of the high-low speed switching valves of the dual-speed motors.

[0073] In this embodiment, the high-low speed switching valve of the dual-speed motor is in a hydraulic control mode, and the switching of the working position of the high-low speed switching valve of the dual-speed motor can be effectively controlled by the on-off control of the second electromagnetic reversing valve 7, thereby realizing the switching of the high-speed mode and the low-speed mode of the vehicle, which is very convenient.

[0074] In some embodiments, the closed hydraulic traveling system control device further comprises a release parking brake system adapted to control the disengagement of the caliper brake from braking the wheel shaft. The release parking brake system comprises a second oil suction pipeline, the caliper brake and the first electromagnetic directional valve 6. The caliper brake is provided with a plurality of caliper brakes and brakes one wheel shaft respectively; the second oil suction pipeline is in communication with each caliper brake respectively; the first electromagnetic directional valve 6 has a first electromagnetic directional valve one position and a first electromagnetic directional valve two position; when the first electromagnetic directional valve is powered, one end of the first electromagnetic directional valve one position is in communication with the first oil suction pipeline, and the other end of the first electromagnetic directional valve one position is in communication with the second oil suction pipeline respectively; when the first electromagnetic directional valve is de-energized, one end of the first electromagnetic directional valve two position is in communication with the oil discharge pipeline, and the other end of the first electromagnetic directional valve two position is in communication with the second oil suction pipeline.

[0075] In the embodiment, when the vehicle is in the release parking mode, the first electromagnetic directional valve 6 is powered, and the second oil suction pipeline is in communication with the first oil suction pipeline. The oil output from the oil suction pump 141 passes through the high-pressure filter 9, the second check valve 8, and the oil port of the first electromagnetic directional valve 6 to form pilot oil, and supply oil to the caliper brake of each double-speed motor, thereby releasing the parking brake. The release parking brake system and the switching valve control system are both arranged on the first oil suction pipeline, and the control of the two modes can be directly realized by using the same oil suction pump 141.

[0076] The prerequisite for forming the pilot oil is that the engine needs to rotate to drive the closed pump 14 to rotate, and the oil suction pump 141 can suck oil. When the engine fails, the oil suction pump 141 cannot supply oil, resulting in that the parking cannot be released. In order to solve the technical problem, the release parking brake system is further provided with a manual release parking mode. The release parking brake system further comprises a manual oil supplement pipeline, an oil suction filter 17, a manual pump 16 and an accumulator 10, the oil suction filter 17, the manual pump 16 and the accumulator 10 are arranged in sequence on the manual oil supplement pipeline, one end of the manual oil supplement pipeline is connected with the oil tank 13, and the other end of the manual oil supplement pipeline is connected with the side of the first oil suction pipeline. The embodiment combines the automatic release parking mode with the manual release parking mode, so that the device has both the automatic release parking function and the manual release parking function. When the engine fails, the manual oil supply of the manual pump 16 is combined with the action of the accumulator 10 to form pressure oil, so as to achieve the purpose of releasing the parking.

[0077] The closed hydraulic traveling system control device of the present application will be described in detail below by taking the example that the wheel, the double-speed motor and the double-speed motor high-low speed switching valve are all provided with four.

[0078] The four double-speed motors in the embodiment are, in sequence, a right front wheel double-speed motor 1 connected with the right front wheel, a right rear wheel double-speed motor 2 connected with the right rear wheel, a left front wheel double-speed motor 3 connected with the left front wheel, and a left rear wheel double-speed motor 4 connected with the left rear wheel. The four double-speed motor high-low speed switching valves are a right front wheel double-speed motor high-low speed switching valve 11, a right rear wheel double-speed motor high-low speed switching valve 21, a left front wheel double-speed motor high-low speed switching valve 31, and a left rear wheel double-speed motor high-low speed switching valve 41. The four caliper disc brakes are a right front wheel caliper disc brake 12, a right rear wheel caliper disc brake 22, a left front wheel caliper disc brake 32, and a left rear wheel caliper disc brake 42.

[0079] The closed variable pump is connected with the four groups of double-speed hydraulic motor pipelines through the adapter valve group 5 to form a closed loop. The left front wheel and the left rear wheel are connected in series through the oil circuit of the adapter valve group 5, and the right front wheel and the right rear wheel are connected in series through the oil circuit of the adapter valve group 5. The proportional electromagnetic valve 146 controls the forward and reverse rotation of the closed variable pump to control the forward and reverse movement and speed of the walking system. When the proportional electromagnetic valve 146 returns to the neutral position, the oil supply is stopped, and the vehicle friction force reaches the deceleration and stop state. The first electromagnetic reversing valve 6 controls the motor parking brake, and the second electromagnetic reversing valve 7 controls the high and low speed of the walking system. The manual pump 16 cooperates with the accumulator 10 to manually release the parking when the engine fails.

[0080] The walking system connects the motors on the same side in series, which can effectively reduce the displacement of the walking pump under the same speed requirement. At the same time, the adapter valve group 5 can avoid the air suction phenomenon caused by insufficient hydraulic oil flow. At the same time, because there is no driving brake system, it is suitable for low-speed form, and the specific upper limit of the driving speed needs to be further calculated according to the working condition and braking distance requirement, which is not described here.

[0081] The closed hydraulic walking system control device of the present application will be described in detail in combination with the low-speed driving mode, high-speed driving mode and parking release mode of the vehicle.

[0082] 1. Low-speed driving mode

[0083] Firstly, the proportional electromagnetic valve 146 controls the direction and displacement of the closed pump 14, which affects the forward and reverse state of the vehicle. The specific principle is not described here.

[0084] In the low-speed driving state, the hydraulic principle is as shown in Figure 1 The double-speed motor is full displacement, and the double-speed motor outputs low speed and high torque.

[0085] Specific oil circuit is: the B port of closed pump 14 oil, through the adapter valve group 5 B port shunt, wherein the adapter valve group 5 B1 port and the left rear wheel double speed motor high low speed switch valve 41 A port connected, through the motor inside, and then by the left rear wheel double speed motor high low speed switch valve 41 R port oil, then and adapter valve group 5 C2 port connected, again through the adapter valve group 5 C1 port and the left front wheel double speed motor high low speed switch valve 31 A port connected, again through the motor inside, and then by the left front wheel double speed motor high low speed switch valve 31 R port oil, with adapter valve group 5 A1 port connected;

[0086] The B2 port of the other side of the adapter valve group 5 is connected with the A port of the right rear wheel double speed motor high low speed switch valve 21, and the oil is discharged from the R port of the right rear wheel double speed motor high low speed switch valve 21 after passing through the motor inside, then connected with the C4 port of the adapter valve group 5, and then connected with the A port of the right front wheel double speed motor high low speed switch valve 11 through the C3 port of the adapter valve group 5, and then connected with the A2 port of the adapter valve group 5 through the R port of the right front wheel double speed motor high low speed switch valve 11 after passing through the motor inside.

[0087] The A1 and A2 ports of the adapter valve group 5 are connected through the A port of the adapter valve group 5, and the A port of the closed pump 14 is connected to complete the circulation of the closed loop.

[0088] The E port of the adapter valve group 5 is connected with the oil tank 13. When the left front wheel and the left rear wheel are connected in series and the flow is not enough due to pipeline and motor leakage, the oil is sucked from the oil tank 13 through the E port of the adapter valve group 5 and the first check valve 51, achieving the effect of oil supplement. The throttle valve 52 balances the flow of the two oil circuits.

[0089] 2, high speed mode

[0090] The second electromagnetic reversing valve 7 electromagnet is powered, the first oil suction pipeline is connected with the cavity of the four double speed motor high low speed switch valves, more specifically, the oil circuit led out by the second electromagnetic reversing valve 7 is divided into two, one is connected with the right front wheel double speed motor high low speed switch valve 11 and the right rear wheel double speed motor high low speed switch valve 21, the other is connected with the left front wheel double speed motor high low speed switch valve 31 and the left rear wheel double speed motor high low speed switch valve 41. The oil from the oil suction pump 141 passes through the high pressure filter 9, the second check valve 8, and then the oil port of the second electromagnetic reversing valve 7, forming a pilot oil, and the four double speed motor high low speed switch valves are reversed.

[0091] The hydraulic principle is shown in Figure 2 The double speed motor is half displacement, and the motor outputs high speed and low torque. The specific oil circuit is exactly the same as the low speed mode. Only the double speed motor is switched from full displacement to half displacement.

[0092] When the proportional solenoid valve 146 switches to the energized state, it only affects the A and B ports of the closed pump 14 to become high-pressure oil ports, and only affects the oil inlet direction of the dual-speed motor, i.e. forward and backward states. The oil circuit connection is exactly the same, only the direction is different.

[0093] 3. Release parking mode

[0094] The oil in the oil tank 13 is automatically or manually controlled to be delivered to each caliper disc brake, so that the caliper disc brake can switch positions and control the caliper disc brake to disengage from the wheel axle.

[0095] Taking the automatic control of the oil supply in the oil tank 13 to each caliper disc brake as an example, such as Figure 1 As shown, the first solenoid directional valve 6 is energized, and the second oil suction line is connected to the first oil suction line. Oil from the oil suction pump 141 passes through the high-pressure filter 9, the second check valve 8, and then through the oil port of the first solenoid directional valve 6 to form pilot oil, which supplies oil to the caliper disc brakes of the four dual-speed motors, thereby releasing the parking brake.

[0096] When the engine malfunctions, manual oil supply via manual pump 16, combined with the function of accumulator 10, forms pressurized oil that is supplied to the four caliper disc brakes, thereby releasing the parking brake.

[0097] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A closed hydraulic travel system control device characterized by comprising: The application relates to a closed-circuit hydraulic system for a vehicle, which comprises: a closed pump (14) having a closed pump oil outlet pipeline (147) and a closed pump oil return pipeline (148); at least two pairs of wheel driving assemblies connected with wheels, the wheel driving assemblies having wheel driving assembly oil lines suitable for controlling the rotating speed and steering of the wheels; a switching valve group (5) suitable for connecting the wheel driving assembly oil lines on the same side in series, connecting the wheel driving assembly oil lines on the two sides in parallel after series connection, and connecting the wheel driving assembly oil lines with the closed pump (14) to form a closed loop so as to reduce the displacement and volume of the closed pump (14); the switching valve group (5) comprises an oil feeding main pipeline (53) and an oil return main pipeline (56), the oil feeding main pipeline (53) is connected with the closed pump oil outlet pipeline (147), the oil return main pipeline (56) is connected with the closed pump oil return pipeline (148), and a connecting oil line is arranged between the oil feeding main pipeline (53) and the oil return main pipeline (56), wherein a stop valve (15) is arranged on the connecting oil line; one end of the oil feeding main pipeline (53) is divided into a first oil feeding pipeline (54) and a second oil feeding pipeline (55), a supplementary oil structure is further arranged between the first oil feeding pipeline (54) and the second oil feeding pipeline (55), the supplementary oil structure is suitable for supplying oil in an oil tank (13) to the first oil feeding pipeline (54) and the second oil feeding pipeline (55), and the supplementary oil structure comprises a first supplementary oil pipeline, a second supplementary oil pipeline, a third supplementary oil pipeline and a first one-way valve (51); the first supplementary oil pipeline is communicated with the first oil feeding pipeline (54), the first supplementary oil pipeline is communicated with the second oil feeding pipeline (55), a supplementary oil E port is formed between the first supplementary oil pipeline and the second supplementary oil pipeline, the first supplementary oil pipeline and the second supplementary oil pipeline are respectively provided with the first one-way valve (51), and the supplementary oil E port is communicated with the oil tank (13) through the third supplementary oil pipeline; when the flow of the closed loop is insufficient due to pipeline and motor leakage of the series-connected wheels, oil is sucked from the oil tank (13) through the first one-way valve (51) of the switching valve group (5) to achieve the effect of supplementary oil supply; the control device further comprises a parking brake releasing system suitable for controlling the disengagement of a caliper disc brake from a wheel shaft; the parking brake releasing system comprises an automatic parking brake releasing system and a manual parking brake releasing system; the manual parking brake releasing system comprises a manual supplementary oil pipeline, an oil suction filter (17), a manual pump (16) and an accumulator (10), the oil suction filter (17), the manual pump (16) and the accumulator (10) are sequentially arranged on the manual supplementary oil pipeline, one end of the manual supplementary oil pipeline is connected with the oil tank (13), and the other end of the manual supplementary oil pipeline is connected with a side of a first oil suction pipeline; when the engine fails, pressure oil is formed through manual oil supply of the manual pump (16) and the action of the accumulator (10) to achieve the purpose of releasing parking.

2. The closed hydraulic travel system control apparatus according to claim 1, characterized by The switching valve group (5) is connected with the wheel driving assembly oil lines and connected with the closed pump oil outlet pipeline (147) and the closed pump oil return pipeline (148) to form a closed loop.

3. The closed hydraulic travel system control apparatus according to claim 1, characterized by The first oil feeding pipeline (54) is suitable for connecting at least two wheel driving assembly oil paths on the right side in series, and the second oil feeding pipeline (55) is suitable for connecting at least two wheel driving assembly oil paths on the left side in series. One end of the oil return main pipeline (56) is connected with the oil return port of the first oil feeding pipeline (54) and the oil return port of the second oil feeding pipeline (55) respectively.

4. The closed hydraulic travel system control apparatus according to claim 3, characterized by The first oil feeding pipeline (54) comprises a first oil inlet pipeline, a first oil outlet pipeline and at least one first transition oil path; the first oil inlet pipeline is connected with the oil inlet port of the wheel driving assembly oil path at the right end; the oil return port of the wheel driving assembly oil path on the right side is connected with the oil inlet port of the wheel driving assembly oil path adjacent thereto through the first transition oil path, so as to realize the series connection of the wheel driving assembly oil paths on the right side; the oil return port of the wheel driving assembly oil path at the left end is connected with the oil return main pipeline (56) through the first oil outlet pipeline. The second oil feeding pipeline (55) comprises a second oil inlet pipeline, a second oil outlet pipeline and at least one second transition oil path; the second oil inlet pipeline is connected with the oil inlet port of the wheel driving assembly oil path at the left end; the oil return port of the wheel driving assembly oil path on the left side is connected with the oil inlet port of the wheel driving assembly oil path adjacent thereto through the second transition oil path, so as to realize the series connection of the wheel driving assembly oil paths on the left side; the oil return port of the wheel driving assembly oil path at the right end is connected with the oil return main pipeline (56) through the second oil outlet pipeline.

5. The closed hydraulic travel system control apparatus of claim 3, wherein A throttle valve (52) is arranged between the first oil feeding pipeline (54) and the second oil feeding pipeline (55), and the throttle valve (52) is suitable for balancing the oil flow of the first oil feeding pipeline (54) and the second oil feeding pipeline (55).

6. The closed hydraulic travel system control apparatus according to any one of claims 1-5, wherein The wheel driving assembly comprises: A double-speed motor comprising a first motor and a second motor, which are coaxially connected with a wheel respectively; the wheel driving assembly oil path comprises a first motor oil path, a second motor oil path and a double-speed motor return oil path; A double-speed motor high-low speed switching valve having a switching valve oil inlet port, a switching valve oil return port, a first working position and a second working position, which is suitable for controlling the first motor oil path and / or the second motor oil path to be connected with the switching valve oil inlet port.

7. The closed hydraulic travel system control apparatus according to claim 6, characterized by The first working position and the second working position of the double-speed motor high-low speed switching valve are switched by a switching valve control system; The switching valve control system comprises a first oil suction pipeline, an oil suction pump (141), a high-pressure filter (9) and a second electromagnetic reversing valve (7); the first oil suction pipeline is connected with an oil tank (13); the oil suction pump (141), the high-pressure filter (9) and the second electromagnetic reversing valve (7) are arranged on the first oil suction pipeline in sequence; the oil outlet ports of the first oil suction pipeline are respectively connected with the cavities of the double-speed motor high-low speed switching valves. The second electromagnetic reversing valve (7) has a second electromagnetic reversing valve one position and a second electromagnetic reversing valve two position; when the second electromagnetic reversing valve (7) is powered, one end of the second electromagnetic reversing valve one position is in communication with the first oil suction pipeline, and the other end of the second electromagnetic reversing valve one position is in communication with the cavities of the high-low speed switching valves of the double-speed motors respectively; when the second electromagnetic reversing valve (7) is powered off, one end of the second electromagnetic reversing valve two position is in communication with the oil discharge pipeline, and the other end of the second electromagnetic reversing valve two position is in communication with the cavities of the high-low speed switching valves of the double-speed motors respectively.

8. The closed hydraulic travel system control apparatus of claim 6, wherein The automatic parking release system comprises a second oil suction pipeline, a caliper disc brake, and a first electromagnetic reversing valve (6); the caliper disc brake is provided with a plurality of caliper disc brakes and brakes one wheel shaft respectively; the second oil suction pipeline is in communication with the caliper disc brakes respectively; the first electromagnetic reversing valve (6) has a first electromagnetic reversing valve one position and a first electromagnetic reversing valve two position; when the first electromagnetic reversing valve (6) is powered, one end of the first electromagnetic reversing valve one position is in communication with the first oil suction pipeline, and the other end of the first electromagnetic reversing valve one position is in communication with the second oil suction pipeline respectively; when the first electromagnetic reversing valve (6) is powered off, one end of the first electromagnetic reversing valve two position is in communication with the oil discharge pipeline, and the other end of the first electromagnetic reversing valve two position is in communication with the second oil suction pipeline.

9. A control method for a closed hydraulic travel system, characterized by, The method is based on the closed hydraulic walking system control device of any one of claims 6-8, comprising a control step of the vehicle running state: According to the high-low speed running state required by the vehicle, the high-low speed switching valve of the double-speed motor of each wheel driving assembly is controlled to switch the working position: when the vehicle needs to run at low speed, the high-low speed switching valve of the double-speed motor of each wheel driving assembly is controlled to switch to the first working position, and the oil output by the closed pump (14) flows through the wheel driving assembly, and is supplied to the first motor and the second motor in parallel at the same time, the double-speed motor is full displacement, and the double-speed motor outputs low speed and high torque; when the vehicle needs to run at high speed, the high-low speed switching valve of the double-speed motor of each wheel driving assembly is controlled to switch to the second working position, and the oil output by the closed pump (14) flows through the wheel driving assembly, and is supplied to the first motor only, the double-speed motor is half displacement, and the double-speed motor outputs high speed and low torque; And / or when the left and right sides of the vehicle need to run differentially, the oil flow of the oil circuit of the left side series connected wheel driving assembly and the oil flow of the oil circuit of the right side series connected wheel driving assembly are adjusted to different states, so that the speeds of the double-speed motors on the left and right sides are different.

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