Hydraulic walking system and self-propelled aerial work platform

Abstract

The present invention discloses a hydraulic walking system and a self-propelled aerial work platform. The hydraulic walking system includes: a first hydraulic motor, including a first oil port and a second oil port; a second hydraulic motor, including a third oil port and a fourth oil port; an oil supply device for supplying oil to the first hydraulic motor and the second hydraulic motor, including a fifth oil port connected to the first hydraulic motor and the second hydraulic motor; a flow dividing and collecting valve, including a collecting oil port, a first flow dividing oil port and a second flow dividing oil port, the collecting oil port is connected to the fifth oil port, the first flow dividing oil port is connected to the first oil port, and the second flow dividing oil port is connected to the third oil port; a bypass pipeline, including a first pipeline with two ends respectively connected to the first flow dividing oil port and the fifth oil port and a second pipeline with two ends respectively connected to the second flow dividing oil port and the fifth oil port; a control valve group, including a first on-off valve for controlling the on-off of the first pipeline and a second on-off valve for controlling the on-off of the second pipeline.

Description

Technical Field

[0001] The present invention relates to the field of hydraulics, and particularly to a hydraulic walking system and a self-propelled aerial work platform. Background Art

[0002] A hydraulic walking system is a walking system that uses hydraulic oil to transmit driving force. Usually, an engine drives a hydraulic pump to rotate, the hydraulic pump supplies hydraulic oil to a hydraulic motor to drive the hydraulic motor to rotate, and the hydraulic motor drives the walking wheels to rotate so that the vehicle can move. In order to enable the vehicle to have better straight-line walking ability, the hydraulic pump is connected to multiple hydraulic motors through a flow dividing and collecting valve. Under the action of the flow dividing and collecting valve, the flow rate of the hydraulic oil passing through the hydraulic motor remains the same, so that the wheel speeds of the walking wheels driven by the hydraulic motor can be the same, enabling a walking machine such as a self-propelled aerial work platform to have better straight-line walking ability. However, the hydraulic oil passing through the flow dividing and collecting valve generates a large pressure loss, causing the system to heat up and increasing fuel consumption. Summary of the Invention

[0003] The purpose of the present invention is to provide a hydraulic walking system that can selectively make the hydraulic oil flowing through the hydraulic motor flow through the flow dividing and collecting valve or not flow through the flow dividing and collecting valve.

[0004] The first aspect of the present invention discloses a hydraulic walking system, comprising:

[0005] A first hydraulic motor for driving a first walking wheel, comprising a first oil port and a second oil port;

[0006] A second hydraulic motor for driving a second walking wheel, comprising a third oil port and a fourth oil port;

[0007] An oil supply device for supplying oil to the first hydraulic motor and the second hydraulic motor, comprising a fifth oil port connected to the first hydraulic motor and the second hydraulic motor;

[0008] A flow dividing and collecting valve, comprising a collecting oil port, a first flow dividing oil port and a second flow dividing oil port, the collecting oil port is connected to the fifth oil port, the first flow dividing oil port is connected to the first oil port, and the second flow dividing oil port is connected to the third oil port;

[0009] A bypass pipeline, comprising a first pipeline with two ends respectively connected to the first flow dividing oil port and the fifth oil port and a second pipeline with two ends respectively connected to the second flow dividing oil port and the fifth oil port;

[0010] A control valve group, comprising a first on-off valve for controlling the on-off of the first pipeline and a second on-off valve for controlling the on-off of the second pipeline.

[0011] In some embodiments, the first on-off valve includes a first hydraulic control valve provided on the first pipeline, the second on-off valve includes a second hydraulic control valve provided on the second pipeline, the hydraulic walking system further includes a first hydraulic control pipeline, the first hydraulic control pipeline is connected to the first hydraulic control end of the first hydraulic control valve and the first hydraulic control end of the second hydraulic control valve, the control valve group further includes a first reversing valve with an oil outlet connected to the first hydraulic control pipeline, and the first reversing valve is configured to adjust the oil pressure of the hydraulic oil sent from the first hydraulic control pipeline to the first hydraulic control ends of the first hydraulic control valve and the second hydraulic control valve by switching the valve position, so as to control the on-off of the first hydraulic control valve and the second hydraulic control valve.

[0012] In some embodiments, the oil supply device further includes a sixth oil port connected to both the second oil port and the fourth oil port, the oil supply device supplies oil to the first hydraulic motor and the second hydraulic motor through the fifth oil port or the sixth oil port, the hydraulic walking system further includes an oil tank and a second reversing valve, the second reversing valve includes two oil inlets respectively connected to the fifth oil port and the sixth oil port, the oil inlet and the oil outlet of the first reversing valve are respectively connected to the oil outlet of the second reversing valve and the oil tank, the first reversing valve is configured to switch the valve position to enable the first hydraulic control pipeline to switch between communicating with the oil outlet of the second reversing valve and communicating with the oil tank, and the second reversing valve is configured to connect its oil outlet to the low oil pressure oil port among the fifth oil port and the sixth oil port.

[0013] In some embodiments, the second reversing valve is a three-position three-way hydraulic control reversing valve, the second reversing valve includes a first oil inlet connected to the fifth oil port, a second oil inlet connected to the sixth oil port and an oil outlet, the first hydraulic control end and the second hydraulic control end of the second reversing valve are respectively communicated with the first oil inlet and the second oil inlet, when the oil pressure at the first hydraulic control end of the second reversing valve is higher than that at the second hydraulic control end, the second reversing valve switches to the first valve position, and the second oil inlet of the second reversing valve is communicated with the oil outlet; when the oil pressure at the second hydraulic control end of the second reversing valve is higher than that at the first hydraulic control end, the second reversing valve switches to the third valve position, and the first oil inlet of the second reversing valve is communicated with the oil outlet; when the oil pressures at the first hydraulic control end and the second hydraulic control end of the second reversing valve are the same, the second reversing valve switches to the second valve position, and the first oil inlet, the second oil inlet and the oil outlet of the second reversing valve are not communicated.

[0014] In some embodiments, the second hydraulic control end of the first hydraulic control valve has two hydraulic control ports. The two hydraulic control ports of the first hydraulic control valve are respectively connected to the fifth oil port and the first shunt oil port. A spring is further provided at the first hydraulic control end of the first hydraulic control valve. When the first hydraulic control pipeline is communicated with the oil outlet of the second reversing valve, the first hydraulic control valve is in its first valve position and the first pipeline is disconnected. When the first hydraulic control pipeline is communicated with the fuel tank, the first hydraulic control valve is in its second valve position and the first pipeline is communicated. The second hydraulic control end of the second hydraulic control valve has two hydraulic control ports. The two hydraulic control ports of the second hydraulic control valve are respectively connected to the fifth oil port and the second shunt oil port. A spring is further provided at the second hydraulic control end of the second hydraulic control valve. When the first hydraulic control pipeline is communicated with the oil outlet of the second reversing valve, the second hydraulic control valve is in its first valve position and the second pipeline is disconnected. When the first hydraulic control pipeline is communicated with the fuel tank, the second hydraulic control valve is in its second valve position and the second pipeline is communicated.

[0015] In some embodiments, the first hydraulic motor and the second hydraulic motor are variable motors. The hydraulic walking system further includes a second hydraulic control pipeline, which is connected to the variable displacement adjusting mechanisms of both the first hydraulic motor and the second hydraulic motor. The hydraulic walking system further includes a third reversing valve, which includes an oil inlet, an oil outlet and an oil drain port. The oil outlet of the third reversing valve is connected to the second hydraulic control pipeline. The oil inlet and the oil drain port of the third reversing valve are respectively connected to the oil outlet of the second reversing valve and the fuel tank. The third reversing valve is configured to adjust the oil pressure of the hydraulic oil fed into the variable displacement adjusting mechanisms of the first hydraulic motor and the second hydraulic motor through the second hydraulic control pipeline by switching the valve position so as to adjust the displacement of the first hydraulic motor and the second hydraulic motor.

[0016] In some embodiments, the first reversing valve and / or the third reversing valve is an electromagnetic reversing valve.

[0017] In some embodiments, the hydraulic walking system further includes a throttle port, and both ends of the throttle port are respectively connected to the first shunt oil port and the second shunt oil port.

[0018] In some embodiments, the hydraulic walking system is a closed hydraulic walking system. The oil supply device includes a sixth oil port connected to both the second oil port and the fourth oil port. The oil supply device includes a bidirectional hydraulic pump, and the bidirectional hydraulic pump includes the fifth oil port and the sixth oil port.

[0019] In some embodiments, the fuel supply device further includes a makeup oil pump, a first check valve, and a second check valve. The outlet of the makeup oil pump is connected to the inlets of the first check valve and the second check valve, and the outlets of the first check valve and the second check valve are respectively connected to the fifth oil port and the sixth oil port.

[0020] A second aspect of the present invention discloses a self-propelled aerial work platform, including the hydraulic walking system described above.

[0021] Based on the hydraulic walking system provided by the present invention, by providing a bypass pipeline and a control valve group, when the road surface is uneven, when the control valve group controls the first pipeline and the second pipeline to be disconnected, the hydraulic oil flows through the flow dividing and collecting valve into the first hydraulic motor and the second hydraulic motor, or the hydraulic oil flowing out from the first hydraulic motor and the second hydraulic motor flows through the flow dividing and collecting valve. The flow dividing and collecting valve can make the flow rate of the hydraulic oil flowing through the first hydraulic motor and the second hydraulic motor the same, and the walking machine has better straight-line walking ability. When the road surface is flat, the control valve group controls the first pipeline and the second pipeline to be connected, so that the hydraulic oil can bypass the flow dividing and collecting valve and enter the first hydraulic motor and the second hydraulic motor from the first pipeline and the second pipeline, or the hydraulic oil flowing out from the first hydraulic motor and the second hydraulic motor bypasses the flow dividing and collecting valve and flows out from the first pipeline and the second pipeline, reducing the hydraulic loss caused by the hydraulic oil flowing through the flow dividing and collecting valve and improving the fuel utilization rate of the system.

[0022] Other features and advantages of the present invention will become clear from the following detailed description of the exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0024] Figure 1 It is a schematic structural principle diagram of the hydraulic walking system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0026] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, further discussion thereof is not required in subsequent drawings.

[0027] For the sake of convenience of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. may be used herein to describe the spatial positional relationship of one device or feature to other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the drawing is inverted, the device described as "above" or "over" other devices or structures will then be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding interpretations of the spatial relative descriptions used herein will be made.

[0028] As Figure 1 shown, the hydraulic walking system of the embodiment of the present invention includes a first hydraulic motor 11, a second hydraulic motor 12, an oil supply device, a flow dividing and collecting valve 13, a bypass pipeline, and a control valve group.

[0029] The first hydraulic motor 11 is used to drive the first walking wheel, and the first hydraulic motor 11 includes a first oil port a1 and a second oil port a2. The second hydraulic motor 12 is used to drive the second walking wheel, and the second hydraulic motor 12 includes a third oil port a3 and a fourth oil port a4. The two oil ports of the first hydraulic motor 11 and the second hydraulic motor 12 are used for oil inlet and oil discharge. In as Figure 1In the illustrated embodiment, the first hydraulic motor 11 and the second hydraulic motor 12 are bidirectional hydraulic motors. By supplying oil and discharging oil through different oil ports of the two oil ports of the bidirectional hydraulic motor, the first hydraulic motor 11 and the second hydraulic motor 12 can be driven to rotate in different directions, so that the first traveling wheel and the second traveling wheel can be driven to rotate in different directions. In some embodiments not shown in the drawings, the first hydraulic motor 11 and the second hydraulic motor 12 may also be unidirectional hydraulic motors. At this time, a transmission device is provided between the first hydraulic motor 11 and the second hydraulic motor 12 and the corresponding traveling wheels for driving. The transmission device can change the transmission direction. When it is necessary to realize the rotation of the traveling wheels in different directions, the transmission direction of the transmission device can be changed.

[0030] The oil supply device is used to supply oil to the first hydraulic motor 11 and the second hydraulic motor 12, and includes a fifth oil port a5 connected to the first hydraulic motor 11 and the second hydraulic motor 12. In the embodiment as Figure 1 shown, the first hydraulic motor 11 and the second hydraulic motor 12 are both bidirectional hydraulic motors. The oil supply device includes a bidirectional hydraulic pump. The bidirectional hydraulic pump includes a fifth oil port a5 and a sixth oil port a6. The fifth oil port a5 of the bidirectional hydraulic pump is connected to one oil port of the first hydraulic motor 11 and one oil port of the second hydraulic motor 12. The sixth oil port a6 of the bidirectional hydraulic pump is connected to the other oil port of the first hydraulic motor 11 and the other oil port of the second hydraulic motor 12. When the first hydraulic motor 11 and the second hydraulic motor 12 rotate in one direction, the fifth oil port a5 of the bidirectional hydraulic pump is used to supply oil to them. When the first hydraulic motor 11 and the second hydraulic motor 12 rotate in opposite directions, the sixth oil port a6 supplies oil to them. The fifth oil port a5 receives the oil discharged from the first hydraulic motor 11 and the second hydraulic motor 12. In some embodiments not shown in the drawings, the first hydraulic motor 11 and the second hydraulic motor 12 are both bidirectional hydraulic motors. The oil supply device may also include a unidirectional hydraulic pump and a reversing valve connected between the first hydraulic motor 11, the second hydraulic motor 12 and the unidirectional hydraulic pump. Through the valve position change of the reversing valve, the unidirectional hydraulic pump is communicated with the oil ports of the first hydraulic motor 11 and the second hydraulic motor 12, so as to realize the rotation of the first hydraulic motor 11 and the second hydraulic motor 12 in different directions. At this time, the fifth oil port a5 can be the oil outlet of the unidirectional hydraulic pump or an oil outlet of the reversing valve.

[0031] The flow dividing and collecting valve 13 includes a collecting oil port b3, a first flow dividing oil port b1, and a second flow dividing oil port b2. When hydraulic oil is input from the collecting oil port b3 and output from the first flow dividing oil port b1 and the second flow dividing oil port b2, the flow rates of the hydraulic oil output from the first flow dividing oil port b1 and the second flow dividing oil port b2 are the same. When hydraulic oil is input from the first flow dividing oil port b1 and the second flow dividing oil port b2 and output from the collecting oil port b3, the flow rates of the hydraulic oil input from the first flow dividing oil port b1 and the second flow dividing oil port b2 are the same. The collecting oil port b3 is connected to the fifth oil port a5, the first flow dividing oil port b1 is connected to the first oil port a1, and the second flow dividing oil port b2 is connected to the third oil port a3. The first hydraulic motor 11 and the second hydraulic motor 12 can respectively drive two corresponding traveling wheels on both sides of the traveling machine, such as the left front wheel and the right front wheel, or the left rear wheel and the right rear wheel. When the hydraulic traveling system is working and the flow dividing and collecting valve 13 is functioning, the flow rates of the hydraulic oil passing through the first hydraulic motor 11 and the second hydraulic motor 12 are the same, so that the rotational speeds of the two corresponding traveling wheels driven are the same, and the traveling machine can maintain good straight traveling ability.

[0032] As Figure 1 shown, the bypass pipeline includes a first pipeline 21 with two ends respectively connected to the first flow dividing oil port b1 and the fifth oil port a5, and a second pipeline 22 with two ends respectively connected to the second flow dividing oil port b2 and the fifth oil port a5.

[0033] The control valve group includes a first on-off valve for controlling the on-off of the first pipeline 21 and a second on-off valve for controlling the on-off of the second pipeline 22. When the first on-off valve connects the first pipeline 21 and the second on-off valve connects the second pipeline 22, the hydraulic oil flowing from the fifth oil port a5 to the first hydraulic motor 11 and the second hydraulic motor 12 or the hydraulic oil flowing from the first hydraulic motor 11 and the second hydraulic motor 12 to the fifth oil port a5 can directly flow through the first pipeline 21 and the second pipeline 22 with less resistance without passing through the flow dividing and collecting valve 13, and the flow dividing and collecting valve 13 does not function. When the first on-off valve disconnects the first pipeline 21 and the second on-off valve disconnects the second pipeline 22, the hydraulic oil still passes through the flow dividing and collecting valve 13, and the flow dividing and collecting valve 13 still functions.

[0034] In the hydraulic walking system of this embodiment, by providing a bypass pipeline and a control valve group, when the road surface is uneven, the control valve group can be used to control the disconnection of the first pipeline 21 and the second pipeline 22. The hydraulic oil flows through the flow dividing and collecting valve 13 and enters the first hydraulic motor 11 and the second hydraulic motor 12, or the hydraulic oil flowing out of the first hydraulic motor 11 and the second hydraulic motor 12 flows through the flow dividing and collecting valve 13. The flow dividing and collecting valve 13 can make the flow rates of the hydraulic oil flowing through the first hydraulic motor 11 and the second hydraulic motor 12 the same, and the walking machine has better straight-line walking ability. When the road surface is flat, the control valve group can be used to control the connection of the first pipeline 21 and the connection of the second pipeline 22. Thus, the hydraulic oil can bypass the flow dividing and collecting valve 13 and enter the first hydraulic motor 11 and the second hydraulic motor 12 from the first pipeline 21 and the second pipeline 22, or the hydraulic oil flowing out of the first hydraulic motor 11 and the second hydraulic motor 12 bypasses the flow dividing and collecting valve 13 and flows out from the first pipeline 21 and the second pipeline 22, reducing the hydraulic loss caused when the hydraulic oil flows through the flow dividing and collecting valve 13, reducing system heat generation, and improving the utilization rate of the hydraulic oil in the system.

[0035] As Figure 1 shown, in some embodiments, the first on-off valve includes a first hydraulic control valve 31 provided on the first pipeline 21, the second on-off valve includes a second hydraulic control valve 32 provided on the second pipeline 22, the hydraulic walking system further includes a first hydraulic control pipeline 41 (the dotted line part in the figure), the first hydraulic control pipeline 41 is connected to the first hydraulic control end of the first hydraulic control valve 31 and the first hydraulic control end of the second hydraulic control valve 32, and the control valve group further includes a first reversing valve 51 with an oil outlet connected to the first hydraulic control pipeline 41. The first reversing valve 51 is configured to adjust the oil pressure of the hydraulic oil sent from the first hydraulic control pipeline 41 to the first hydraulic control ends of the first hydraulic control valve 31 and the second hydraulic control valve 32 by switching the valve position, so as to control the on-off of the first pipeline 21 and the second pipeline 22 by the first hydraulic control valve 31 and the second hydraulic control valve 32. For example, in Figure 1In the illustrated embodiment, when the first reversing valve 51 switches its valve position to connect the first hydraulic control pipeline 41 to high-pressure hydraulic oil, the first hydraulic control pipeline 41 delivers the high-pressure hydraulic oil to the first hydraulic control end of the first hydraulic control valve 31 and the first hydraulic control end of the second hydraulic control valve 32. At this time, the first hydraulic control valve 31 and the second hydraulic control valve 32 are in the off state, that is, the first pipeline 21 and the second pipeline 22 are in the off state. When the first reversing valve 51 switches its valve position to connect the first hydraulic control pipeline 41 to low-pressure hydraulic oil, the first hydraulic control pipeline 41 delivers the low-pressure hydraulic oil to the first hydraulic control end of the first hydraulic control valve 31 and the first hydraulic control end of the second hydraulic control valve 32. At this time, the first hydraulic control valve 31 and the second hydraulic control valve 32 switch their valve positions to be in the connected state, that is, the first pipeline 21 and the second pipeline 22 are in the connected state. In this embodiment, the first reversing valve 51 is adopted to simultaneously control the first hydraulic control valve 31 and the second hydraulic control valve 32 in a hydraulic control manner. Since the hydraulic control manner is sensitive in response, the first hydraulic control valve 31 and the second hydraulic control valve 32 can be quickly and accurately controlled to be simultaneously off or connected, so that the state of the hydraulic walking system can be quickly changed.

[0036] In some embodiments, as Figure 1 shown, the oil supply device further includes a sixth oil port a6 connected to both the second oil port a2 and the fourth oil port a4. The oil supply device supplies oil to the first hydraulic motor 11 and the second hydraulic motor 12 through the fifth oil port a5 or the sixth oil port a6. The hydraulic walking system further includes an oil tank 19 and a second reversing valve 52. The second reversing valve 52 includes two oil inlets respectively connected to the fifth oil port a5 and the sixth oil port a6. The oil inlet and the oil outlet of the first reversing valve 51 are respectively connected to the oil outlet of the second reversing valve 52 and the oil tank 19. The first reversing valve 51 is configured to switch its valve position to make the first hydraulic control pipeline 41 switch between being connected to the oil outlet of the second reversing valve 52 and being connected to the oil tank 19. The second reversing valve 52 is configured to connect its oil outlet to the low-oil-pressure oil port among the fifth oil port a5 and the sixth oil port a6. In this embodiment, when the first hydraulic control pipeline 41 is to access high-pressure hydraulic oil, the first hydraulic control pipeline is always connected to the low-oil-pressure oil port among the fifth oil port a5 and the sixth oil port a6, so that the first hydraulic control pipeline 41 can obtain high-pressure hydraulic oil with relatively stable pressure, and at the same time, the pressure of the obtained high-pressure hydraulic oil is suitable for the hydraulic control end of the hydraulic control valve.

[0037] In some embodiments, as Figure 1As shown, the second reversing valve 52 is a three-position three-way hydraulically controlled reversing valve. The second reversing valve 52 includes a first oil inlet connected to the fifth oil port a5, a second oil inlet connected to the sixth oil port a6, and an oil outlet. The first hydraulic control end and the second hydraulic control end of the second reversing valve 52 are respectively communicated with the first oil inlet and the second oil inlet. The high-oil-pressure hydraulic control end among the first hydraulic control end and the second hydraulic control end of the second reversing valve 52 pushes the second reversing valve 52 to switch its valve position. The high-oil-pressure hydraulic control end refers to the hydraulic control end with a larger oil pressure among the first hydraulic control end and the second hydraulic control end of the second reversing valve 52. When the first hydraulic control end of the second reversing valve 52 is the high-oil-pressure hydraulic control end, that is, the oil pressure of the first hydraulic control end is greater than that of the second hydraulic control end, at this time, the hydraulic oil pressure of the fifth oil port a5 is greater than the pressure of the sixth oil port a6, and the second reversing valve 52 switches to the first valve position, and the second oil inlet of the second reversing valve 52 is communicated with the oil outlet. When the second hydraulic control end of the second reversing valve 52 is the high-oil-pressure hydraulic control end, that is, the oil pressure of the second hydraulic control end is greater than that of the first hydraulic control end, at this time, the hydraulic oil pressure of the sixth oil port a6 is greater than the fifth oil port a5, and the second reversing valve 52 switches to the third valve position, and the first oil inlet of the second reversing valve 52 is communicated with the oil outlet. When the oil pressures of the first hydraulic control end and the second hydraulic control end of the second reversing valve 52 are the same, the second reversing valve 52 switches to the second valve position, and the first oil inlet, the second oil inlet, and the oil outlet of the second reversing valve 52 are all not communicated. This embodiment can conveniently and reliably connect the oil outlet of the second reversing valve 52 with the low-oil-pressure oil port among the fifth oil port a5 and the sixth oil port a6.

[0038] In some embodiments, the second hydraulic control end of the first hydraulic control valve 31 has two hydraulic control ports. The two hydraulic control ports of the first hydraulic control valve 31 are respectively connected to the fifth oil port a5 and the first shunt oil port b1. A spring is further provided at the first hydraulic control end of the first hydraulic control valve 31. When the first hydraulic control pipeline 41 is communicated with the oil outlet of the second reversing valve 52, the first hydraulic control valve 31 is in its first valve position, and the first pipeline 21 is disconnected. When the first hydraulic control pipeline 41 is communicated with the fuel tank 19, the first hydraulic control valve 31 is in its second valve position, and the first pipeline 21 is communicated; the second hydraulic control end of the second hydraulic control valve 32 has two hydraulic control ports. The two hydraulic control ports of the second hydraulic control valve 32 are respectively connected to the fifth oil port a5 and the second shunt oil port b2. A spring is further provided at the second hydraulic control end of the second hydraulic control valve 32. When the first hydraulic control pipeline 41 is communicated with the oil outlet of the second reversing valve 52, the second hydraulic control valve 32 is in its first valve position, and the second pipeline 22 is disconnected. When the first hydraulic control pipeline 41 is communicated with the fuel tank 19, the second hydraulic control valve 32 is in its second valve position, and the second pipeline 22 is communicated. This embodiment can stably and reliably realize the hydraulic control valve position switching of the first hydraulic control valve and the second hydraulic control valve.

[0039] In some embodiments, the first hydraulic motor 11 and the second hydraulic motor 12 are variable motors. The hydraulic walking system further includes a second hydraulic control pipeline 42, and the second hydraulic control pipeline 42 is connected to the variable displacement adjusting mechanisms 18 of both the first hydraulic motor 11 and the second hydraulic motor 12. The hydraulic walking system further includes a third reversing valve 53. The third reversing valve 53 includes an oil inlet, an oil outlet, and an oil drain port. The oil outlet of the third reversing valve 53 is connected to the second hydraulic control pipeline 42, and the oil inlet and the oil drain port of the third reversing valve 53 are respectively connected to the oil outlet of the second reversing valve 52 and the fuel tank 19. The third reversing valve 53 is configured to adjust the oil pressure of the hydraulic oil entering the variable displacement adjusting mechanisms 18 of the first hydraulic motor 11 and the second hydraulic motor 12 by switching the valve position to adjust the displacement of the first hydraulic motor 11 and the second hydraulic motor 12. By providing the third reversing valve 53 in this embodiment, the displacement of the first hydraulic motor 11 and the second hydraulic motor 12 can be adjusted, so that the rotational speed-torque relationship of the first hydraulic motor 11 and the second hydraulic motor 12 can be adjusted. For example, a high-torque low-speed walking mode of the walking machine can be achieved, or a low-torque high-speed walking mode of the walking machine can be achieved. At the same time, the third reversing valve 53 is connected to the oil outlet of the second reversing valve 52, which can stabilize the pressure of the hydraulic oil when the hydraulic control pipeline of the variable displacement adjusting mechanism 18 accesses high-pressure hydraulic oil.

[0040] In some embodiments, the first reversing valve 51 and / or the third reversing valve 53 is an electromagnetic reversing valve.

[0041] In some embodiments, as Figure 1 shown, the hydraulic walking system further includes a throttle orifice 17, and both ends of the throttle orifice 17 are respectively connected to the first shunt oil port b1 and the second shunt oil port b2. Setting the throttle orifice 17 can adaptively adjust the flow rate of the hydraulic oil between the first hydraulic motor 11 and the second hydraulic motor 12 when there is a rotational speed difference between the first hydraulic motor 11 and the second hydraulic motor 12 during the turning of the walking machine.

[0042] In some embodiments, the hydraulic walking system is a closed-loop hydraulic walking system. The oil supply device further includes a sixth oil port a6 that is connected to both the second oil port a2 and the fourth oil port a4. The oil supply device includes a bidirectional hydraulic pump 14, and the bidirectional hydraulic pump 14 includes a fifth oil port a5 and a sixth oil port a6.

[0043] In some embodiments, the oil supply device further includes a makeup oil pump 15, a first one-way valve 161, and a second one-way valve 162. The oil outlet of the makeup oil pump 15 is connected to the oil inlets of the first one-way valve 161 and the second one-way valve 162, and the oil outlets of the first one-way valve 161 and the second one-way valve 162 are respectively connected to the fifth oil port a5 and the sixth oil port a6. This setting can achieve the makeup oil of the hydraulic walking system, which is beneficial to improving the stability and reliability of the hydraulic walking system.

[0044] In some embodiments, a self-propelled aerial work platform is also disclosed, including a hydraulic walking system.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that it is still possible to modify the specific implementation manners of the present invention or perform equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered by the scope of the technical solutions claimed in the present invention.

Claims

1. A hydraulic walking system, characterized in that, it comprises: a first hydraulic motor (11) for driving a first walking wheel, including a first oil port (a1) and a second oil port (a2); a second hydraulic motor (12) for driving a second walking wheel, including a third oil port (a3) and a fourth oil port (a4); an oil supply device for supplying oil to the first hydraulic motor (11) and the second hydraulic motor (12), including a fifth oil port (a5) connected to the first hydraulic motor (11) and the second hydraulic motor (12); a flow dividing and collecting valve (13), including a collecting oil port (b3), a first flow dividing oil port (b1) and a second flow dividing oil port (b2), the collecting oil port (b3) is connected to the fifth oil port (a5), the first flow dividing oil port (b1) is connected to the first oil port (a1), and the second flow dividing oil port (b2) is connected to the third oil port (a3); a bypass pipeline, including a first pipeline (21) with two ends respectively connected to the first flow dividing oil port (b1) and the fifth oil port (a5) and a second pipeline (22) with two ends respectively connected to the second flow dividing oil port (b2) and the fifth oil port (a5); a control valve group, including a first on-off valve for controlling the on-off of the first pipeline (21) and a second on-off valve for controlling the on-off of the second pipeline (22); Among them, the first on-off valve includes a first hydraulic control valve (31) provided on the first pipeline (21), the second on-off valve includes a second hydraulic control valve (32) provided on the second pipeline (22), the hydraulic walking system further includes a first hydraulic control pipeline (41), the first hydraulic control pipeline (41) is connected to the first hydraulic control end of the first hydraulic control valve (31) and the first hydraulic control end of the second hydraulic control valve (32), the control valve group further includes a first reversing valve (51) whose oil outlet is connected to the first hydraulic control pipeline (41), the first reversing valve (51) is configured to adjust the oil pressure of the hydraulic oil sent from the first hydraulic control pipeline (41) to the first hydraulic control ends of the first hydraulic control valve (31) and the second hydraulic control valve (32) by switching the valve position, so as to control the on-off of the first hydraulic control valve (31) and the second hydraulic control valve (32), the oil supply device further includes a sixth oil port (a6) connected to both the second oil port (a2) and the fourth oil port (a4), the oil supply device supplies oil to the first hydraulic motor (11) and the second hydraulic motor (12) through the fifth oil port (a5) or the sixth oil port (a6), the hydraulic walking system further includes an oil tank (19) and a second reversing valve (52), the second reversing valve (52) includes two oil inlets respectively connected to the fifth oil port (a5) and the sixth oil port (a6), the oil inlet and the oil drain port of the first reversing valve (51) are respectively connected to the oil outlet of the second reversing valve (52) and the oil tank (19), the first reversing valve (51) is configured to switch the valve position to make the first hydraulic control pipeline (41) switch between being communicated with the oil outlet of the second reversing valve (52) and being communicated with the oil tank (19), the second reversing valve (52) is configured to make its oil outlet communicate with the low oil pressure oil port among the fifth oil port (a5) and the sixth oil port (a6); the hydraulic walking system further includes a throttle port (17), both ends of the throttle port (17) are respectively connected to the first shunt oil port (b1) and the second shunt oil port (b2); the oil supply device includes a bidirectional hydraulic pump (14), and the bidirectional hydraulic pump (14) includes the fifth oil port (a5) and the sixth oil port (a6).

2. The hydraulic walking system according to claim 1, characterized in that, The second reversing valve (52) is a three-position three-way hydraulically controlled reversing valve. The second reversing valve (52) includes a first oil inlet connected to the fifth oil port (a5), a second oil inlet connected to the sixth oil port (a6), and an oil outlet. The first hydraulic control end and the second hydraulic control end of the second reversing valve (52) are respectively communicated with the first oil inlet and the second oil inlet. When the oil pressure at the first hydraulic control end of the second reversing valve (52) is higher than that at the second hydraulic control end, the second reversing valve (52) switches to the first valve position, and the second oil inlet of the second reversing valve (52) is communicated with the oil outlet. When the oil pressure at the second hydraulic control end of the second reversing valve (52) is higher than that at the first hydraulic control end, the second reversing valve (52) switches to the third valve position, and the first oil inlet of the second reversing valve (52) is communicated with the oil outlet. When the oil pressures at the first hydraulic control end and the second hydraulic control end of the second reversing valve (52) are the same, the second reversing valve (52) switches to the second valve position, and the first oil inlet, the second oil inlet, and the oil outlet of the second reversing valve (52) are not communicated with each other.

3. The hydraulic walking system according to claim 1, characterized in that, the second hydraulic control end of the first hydraulic control valve (31) has two hydraulic control ports, the two hydraulic control ports of the first hydraulic control valve (31) are respectively connected to the fifth oil port (a5) and the first shunt oil port (b1), and a spring is further provided at the first hydraulic control end of the first hydraulic control valve (31). When the first hydraulic control pipeline (41) is communicated with the oil outlet of the second reversing valve (52), the first hydraulic control valve (31) is in its first valve position, and the first pipeline (21) is disconnected. When the first hydraulic control pipeline (41) is communicated with the fuel tank (19), the first hydraulic control valve (31) is in its second valve position, and the first pipeline (21) is communicated; the second hydraulic control end of the second hydraulic control valve (32) has two hydraulic control ports, the two hydraulic control ports of the second hydraulic control valve (32) are respectively connected to the fifth oil port (a5) and the second shunt oil port (b2), and a spring is further provided at the second hydraulic control end of the second hydraulic control valve (32). When the first hydraulic control pipeline (41) is communicated with the oil outlet of the second reversing valve (52), the second hydraulic control valve (32) is in its first valve position, and the second pipeline (22) is disconnected. When the first hydraulic control pipeline (41) is communicated with the fuel tank (19), the second hydraulic control valve (32) is in its second valve position, and the second pipeline (22) is communicated.

4. The hydraulic walking system according to claim 1, characterized in that, The first hydraulic motor (11) and the second hydraulic motor (12) are variable motors. The hydraulic walking system further includes a second hydraulic control pipeline (42), and the second hydraulic control pipeline (42) is connected to the variable displacement adjusting mechanisms (18) of the first hydraulic motor (11) and the second hydraulic motor (12). The hydraulic walking system further includes a third reversing valve (53). The third reversing valve (53) includes an oil inlet, an oil outlet, and an oil drain port. The oil outlet of the third reversing valve (53) is connected to the second hydraulic control pipeline (42). The oil inlet and the oil drain port of the third reversing valve (53) are respectively connected to the oil outlet of the second reversing valve (52) and the fuel tank (19). The third reversing valve (53) is configured to adjust the oil pressure of the hydraulic oil fed into the variable displacement adjusting mechanisms (18) of the first hydraulic motor (11) and the second hydraulic motor (12) through the second hydraulic control pipeline (42) by switching the valve position so as to adjust the displacement of the first hydraulic motor (11) and the second hydraulic motor (12).

5. The hydraulic walking system according to claim 4, characterized in that, the first reversing valve (51) and / or the third reversing valve (53) is an electromagnetic reversing valve.

6. The hydraulic walking system according to claim 1, characterized in that, the oil supply device further includes a makeup oil pump (15), a first check valve (161), and a second check valve (162). The oil outlet of the makeup oil pump (15) is connected to the oil inlets of the first check valve (161) and the second check valve (162). The oil outlets of the first check valve (161) and the second check valve (162) are respectively connected to the fifth oil port (a5) and the sixth oil port (a6).

7. A self-propelled aerial work platform, characterized in that, it includes the hydraulic walking system according to any one of claims 1 to 6.

Images