Hydraulic system for walking and aerial work equipment

Abstract

The application discloses a walking hydraulic system, comprising a first reversing valve, a shunt valve and a high-low gear control valve, the first reversing valve comprises an oil inlet, an oil return, a first working oil outlet and a second working oil outlet, the shunt valve comprises a first oil port, a second oil port connected with the high-low gear control valve and a third oil port connected with a first oil port of a second motor, the high-low gear control valve has a high gear and a low gear, when the high-low gear control valve is in the high gear state, the second oil port of the shunt valve is communicated with the first oil port of the second motor, the second oil port of the second motor is communicated with the second oil port of the first motor, the first motor and the second motor are connected in series, when the high-low gear control valve is in the low gear state, the second oil port of the shunt valve is communicated with the second oil port of the first motor, the second oil port of the second motor is communicated with the second working oil outlet of the first reversing valve, the first motor and the second motor are connected in parallel. On the basis of not affecting the high-low gear function of the existing aerial work platform, the anti-slip function is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to a hydraulic system, in particular to a walking hydraulic system. Furthermore, the present application also relates to an aerial work equipment. BACKGROUND

[0002] At present, the hydraulic walking system of the mainstream two-wheel drive scissor-type aerial work platform in the market controls the series and parallel switching of the oil paths of two hydraulic walking motors through a magnetic valve, realizes the change of high and low speed and torque gears, and thus meets the needs of improving work efficiency through low-torque high-speed walking on flat ground and improving passing ability through high-torque low-speed walking on slopes.

[0003] However, in the existing technical solution, the hydraulic walking system of the scissor-type aerial work platform only adopts a simple series and parallel solution for the oil paths of two hydraulic walking motors, and the drive wheel of the mainstream scissor-type aerial work platform is a rigid axle, and the drive wheel does not have sufficient adjustment ability of the contact pressure with the undulating ground. Therefore, when the two hydraulic walking motor oil paths are in parallel during low-speed driving, the device cannot normally drive when one side of the motor often slips and idles in the case of uneven ground or wet ground. SUMMARY

[0004] The purpose of the present application is to provide a walking hydraulic system which can realize the anti-slip function without affecting the high and low gear functions of the existing scissor-type aerial work platform.

[0005] The purpose of the present application is to provide a walking hydraulic system which can realize the anti-slip function without affecting the high and low gear functions of the existing scissor-type aerial work platform.

[0006] In order to achieve the above object, the present application provides a walking hydraulic system in one aspect, comprising a first reversing valve, a shunt valve and a high-low gear control valve, the first reversing valve comprising an oil inlet, an oil return, a first working oil port connected with a first oil port of the shunt valve and a second working oil port for connecting with a first oil port of a first motor, the shunt valve comprising the first oil port, a second oil port connected with the high-low gear control valve and a third oil port for connecting with a first oil port of a second motor, the high-low gear control valve having a high gear position and a low gear position, when the high-low gear control valve is in the high gear position state, the second oil port of the shunt valve is communicated with the first oil port of the second motor through the high-low gear control valve, and the second oil port of the second motor is communicated with the second working oil port of the first reversing valve through the high-low gear control valve, so that the first motor and the second motor are connected in series, when the high-low gear control valve is in the low gear position state, the second oil port of the shunt valve is communicated with the second working oil port of the first reversing valve through the high-low gear control valve, and the second oil port of the second motor is communicated with the second working oil port of the first reversing valve through the high-low gear control valve, so that the first motor and the second motor are connected in parallel.

[0007] In some embodiments, a first oil supplementing oil path and a second oil supplementing oil path are further included, the high-low gear control valve comprising a first oil port connected with the second oil port of the shunt valve, a second oil port connected with the second oil port of the first motor, a third oil port connected with the first oil port of the first motor, a fourth oil port connected with the first oil port of the second motor, a fifth oil port connected with the second oil port of the first motor and a sixth oil port connected with the second oil port of the second motor, one end of the first oil supplementing oil path being connected with the oil return of the first reversing valve, and the other end being connected on an oil path between the fifth oil port of the high-low gear control valve and the second oil port of the first motor, so as to be able to supplement oil to the first motor or the second motor when the high-low gear control valve is in the high gear position state and the wheels are steering, one end of the second oil supplementing oil path being connected with the oil return of the first reversing valve, and the other end being connected with the first oil port of the second motor, so as to be able to supplement oil to the second motor when the high-low gear control valve is in the low gear position state and the wheels are steering.

[0008] In some embodiments, the high-low gear control valve comprises a second reversing valve connected with the first oil port, the second oil port, the third oil port, the fourth oil port, the fifth oil port and the sixth oil port of the high-low gear control valve respectively, when the high-low gear control valve is in the high gear state, the first oil port and the fourth oil port of the high-low gear control valve are communicated through the second reversing valve, the sixth oil port of the high-low gear control valve and the fifth oil port are communicated through the second reversing valve, when the high-low gear control valve is in the low gear state, the first oil port and the second oil port of the high-low gear control valve are communicated through the second reversing valve, the sixth oil port of the high-low gear control valve and the third oil port are communicated through the second reversing valve.

[0009] In some embodiments, the high-low gear control valve comprises a third reversing valve and a fourth reversing valve, the third reversing valve is connected with the first oil port, the fourth oil port, the fifth oil port and the sixth oil port of the high-low gear control valve respectively, the fourth reversing valve is connected with the first oil port, the second oil port, the third oil port and the sixth oil port of the high-low gear control valve respectively, when the high-low gear control valve is in the high gear state, the first oil port and the fourth oil port of the high-low gear control valve are communicated through the third reversing valve, the sixth oil port of the high-low gear control valve and the fifth oil port are communicated through the third reversing valve, when the high-low gear control valve is in the low gear state, the first oil port and the second oil port of the high-low gear control valve are communicated through the fourth reversing valve, the sixth oil port of the high-low gear control valve and the third oil port are communicated through the fourth reversing valve.

[0010] In some embodiments, the first oil supplementing oil path is provided with a first one-way valve for guiding the hydraulic oil to flow from the oil return port of the first reversing valve to the high-low gear control valve unidirectionally, and the second oil supplementing oil path is provided with a second one-way valve for guiding the hydraulic oil to flow from the oil return port of the first reversing valve to the second motor unidirectionally.

[0011] In some embodiments, the oil inlet port of the first reversing valve is connected with the hydraulic pump through an oil inlet oil path.

[0012] In some embodiments, the oil inlet oil path is provided with a flow valve, the flow valve comprises a first oil port connected with the hydraulic pump, a second oil port connected with the oil inlet port of the first reversing valve and a third oil port.

[0013] In some embodiments, the third oil port of the flow valve is connected with a steering oil cylinder through a fifth reversing valve, and the steering oil cylinder is connected with the oil inlet oil path through the fifth reversing valve, when the fifth reversing valve is in the neutral state, the third oil port of the flow valve is communicated with the oil inlet oil path through the fifth reversing valve.

[0014] In some embodiments, the oil inlet oil way is connected with a brake oil inlet.

[0015] In some embodiments, the oil return port of the first reversing valve is connected with an oil return oil way.

[0016] In some embodiments, a third one-way valve is arranged on the oil return oil way.

[0017] In some embodiments, a filter is arranged on the oil return oil way.

[0018] In some embodiments, the split ratio of the split valve is 50%:50%.

[0019] Another aspect of the present application provides a high-altitude working device provided with the walking hydraulic system according to any one of the above technical solutions.

[0020] Through the above technical solutions, the present application has the following beneficial effects:

[0021] Without changing the existing user usage habits, the present application adopts a split valve combined with a high-low gear control valve to form an oil way in which two driving motors are connected in series and parallel and switchable, so as to realize the conversion of high and low speed gears. In the process of realizing high-speed gear fast driving, both of the two motors in the process of driving have power output, which reduces the probability that the wheel slip idling leads to the other motor and the wheel without power, thereby improving the road adaptability and passing performance of the device.

[0022] Other features and advantages of the present application will be described in detail in the following specific embodiment part. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, and are used together with the following specific embodiments to explain the present application, but do not constitute a limitation on the present application. In the drawings:

[0024] Figure 1 is a hydraulic principle diagram of the walking hydraulic system in the first specific embodiment of the present application.

[0025] Figure 2 is a hydraulic principle diagram of the walking hydraulic system in the second specific embodiment of the present application.

[0026] EXPLANATION OF REFERENCE NUMERALS

[0027] 1 first reversing valve P1 oil inlet of the first reversing valve

[0028] T1 oil return port of the first reversing valve E1 first working oil port of the first reversing valve

[0029] E2 second working oil port of the first reversing valve 2 split valve

[0030] F1 port of the first flow valve F2 port of the second flow valve

[0031] F3 port of the third flow valve 3 first motor

[0032] D first port of the first motor C second port of the first motor

[0033] 4 second motor A first port of the second motor

[0034] B second port of the second motor G1 first port of the high-low gear control valve

[0035] G2 second port of the high-low gear control valve G3 third port of the high-low gear control valve

[0036] G4 fourth port of the high-low gear control valve G5 fifth port of the high-low gear control valve G6 sixth port of the high-low gear control valve 5 second directional valve

[0037] 6 third directional valve 7 fourth directional valve

[0038] 8 first check valve 9 second check valve

[0039] 10 hydraulic pump 11 flow valve

[0040] H1 first port of the flow valve H2 second port of the flow valve

[0041] H3 third port of the flow valve 12 fifth directional valve

[0042] 13 steering oil cylinder 14 third check valve

[0043] 15 filter Br brake inlet DETAILED DESCRIPTION

[0044] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings, it should be understood that the specific embodiments described herein are only used to explain and illustrate the present application, the protection scope of the present application is not limited to the specific embodiments described below.

[0045] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "arranged", "mounted", "connected" should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrally connected, it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0046] In addition, the terms "first", "second", "third", "fourth", "fifth", "sixth" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features, therefore, the features limited by "first", "second", "third", "fourth", "fifth", "sixth" can be explicitly or implicitly include one or more of the features.

[0047] First of all, it needs to be pointed out that the hydraulic system of the walking hydraulic system of the present application belongs to the field of hydraulic pressure, and for the skilled person in the field, the essential technical concept lies in the hydraulic connection relationship. Related hydraulic elements, such as reversing valve, motor, shunt valve, flow valve, hydraulic pump, filter, check valve, etc. all belong to the well-known ones for the skilled person in the field, and are also common components in existing hydraulic systems, therefore, the following description of these hydraulic elements is only brief. After knowing the technical concept of the present application, the skilled person in the field can also simply replace the oil way or valve, etc. to realize the function of the hydraulic system of the walking hydraulic system of the present application, which also belongs to the protection scope of the present application.

[0048] As shown in Figure 1 and Figure 2 , the present application provides a walking hydraulic system, comprising a first reversing valve 1, a shunt valve 2 and a high-low gear control valve, the first reversing valve 1 comprising an oil inlet P1, an oil return T1, a first working oil port E1 and a second working oil port E2, the first working oil port E1 of the first reversing valve 1 being connected with the first oil port F1 of the shunt valve 2, the second working oil port E2 of the first reversing valve 1 being used for connecting with the first oil port D of the first motor 3; the shunt valve 2 comprising a first oil port F1, a second oil port F2 and a third oil port F3, the second oil port F2 of the shunt valve 2 being connected with the high-low gear control valve, the third oil port F3 of the shunt valve 2 being used for connecting with the first oil port A of the second motor 4; the high-low gear control valve having two states of high speed gear and low speed gear, when the high-low gear control valve is in the state of high speed gear, the second oil port F2 of the shunt valve 2 is communicated with the first oil port A of the second motor 4 through the high-low gear control valve, the second oil port B of the second motor 4 is communicated with the second oil port C of the first motor 3 through the high-low gear control valve, realizing that the first motor 3 and the second motor 4 are in series, when the high-low gear control valve is in the state of low speed gear, the second oil port F2 of the shunt valve 2 is communicated with the second oil port C of the first motor 3 through the high-low gear control valve, the second oil port B of the second motor 4 is communicated with the second working oil port E2 of the first reversing valve 1 through the high-low gear control valve, realizing that the first motor 3 and the second motor 4 are in parallel.

[0049] When the first motor 3 and the second motor 4 are in parallel, the hydraulic oil flowing into the first oil port F1 of the shunt valve 2 is divided into two paths, one of which flows to the second motor 4 through the third oil port F3 of the shunt valve 2, and the other of which flows to the first motor 3 through the second oil port F2 of the shunt valve 2 and the high-low gear control valve, so that the flow of the two motors is distributed according to the design, achieving the purpose of stable flow of the two motors not affected by the load, preventing the motor from idling when the wheels slip. Moreover, by controlling the high-low gear control valve to reverse, the two motor circuits can be changed from series to parallel, so that the walking hydraulic system has two gears of high speed and low speed, and the walking of the equipment takes into account the needs of both driving efficiency and climbing ability.

[0050] In the preferred case, the shunt ratio of the shunt valve 2 is 50%:50%, so that the flow of the two motors is evenly distributed, achieving the purpose of stable flow of the two motors not affected by the load, preventing the motor from idling when the wheels slip.

[0051] In some embodiments, in order to prevent the motor speed from being inconsistent due to the wheel speed difference when the equipment is turning, a first oil supplementing oil path and a second oil supplementing oil path can be provided in the system. Specifically, as shown in FIG. 6, the first oil supplementing oil path is connected between the first oil port F1 of the shunt valve 2 and the first motor 3, and the second oil supplementing oil path is connected between the second oil port F2 of the shunt valve 2 and the second motor 4. Figure 1As shown, the high / low gear control valve includes a first port G1, a second port G2, a third port G3, a fourth port G4, a fifth port G5, and a sixth port G6. The first port G1 of the high / low gear control valve is connected to the second port F2 of the flow divider valve 2. The second port G2 of the high / low gear control valve is connected to the second port C of the first motor 3. The fifth port G5 of the high / low gear control valve is also connected to the second port C of the first motor 3. Furthermore, one end of the first replenishing oil circuit is connected to the return port T1 of the first directional valve 1, and the other end of the first replenishing oil circuit is connected to the high / low gear control valve. The second oil port G2 and the fifth oil port G5 of the valve are respectively connected to the second oil port C of the first motor 3. The third oil port G3 of the high and low gear control valve is respectively connected to the second working oil port E2 of the first reversing valve 1 and the first oil port D of the first motor 3. The fourth oil port G4 of the high and low gear control valve is connected to the first oil port A of the second motor 4. The sixth oil port G6 of the high and low gear control valve is connected to the second oil port B of the second motor 4. One end of the second oil replenishment circuit is connected to the return oil port T1 of the first reversing valve 1, and the other end of the second oil replenishment circuit is connected to the first oil port A of the second motor 4. When the high / low gear control valve is in the high-speed gear state, and the motor speed is inconsistent due to the wheel speed difference when the equipment turns, the return oil output from the return port T1 of the first reversing valve 1 can directly replenish oil to the first motor 3 through the first replenishing oil circuit, or replenish oil to the second motor 4 through the fifth oil port G5 and the sixth oil port G6 of the high / low gear control valve. When the high / low gear control valve is in the low-speed gear state, and the motor speed is inconsistent due to the wheel speed difference when the equipment turns, the return oil output from the return port T1 of the first reversing valve 1 is divided into two paths. One path can directly replenish oil to the first motor 3 through the first replenishing oil circuit, and the other path can directly replenish oil to the second motor 4 through the second replenishing oil circuit. That is, when the motor speed is inconsistent due to the wheel speed difference when the equipment turns, oil is replenished to the motor with a larger flow demand.

[0052] Furthermore, a first check valve 8 can be installed on the first replenishment oil line. The first check valve 8 guides the hydraulic oil to flow unidirectionally from the return port T1 of the first directional valve 1 to the high / low gear control valve, replenishing oil to the motor with the higher flow demand when the motor speed is inconsistent due to wheel speed differences during equipment turning. A second check valve 9 can be installed on the second replenishment oil line. The second check valve 9 guides the hydraulic oil to flow unidirectionally from the return port T1 of the first directional valve 1 to the second motor 4, replenishing oil to the motor with the higher flow demand when the motor speed is inconsistent due to wheel speed differences during equipment turning.

[0053] As a specific embodiment of a high / low gear control valve, such as Figure 1As shown, the high-low gear control valve is specifically composed of a second reversing valve 5, which can be a two-position six-way reversing valve, such as a two-position six-way electromagnetic reversing valve. The second reversing valve 5 is connected with the first oil port G1, the second oil port G2, the third oil port G3, the fourth oil port G4, the fifth oil port G5 and the sixth oil port G6 of the high-low gear control valve. When the high-low gear control valve is in the high-speed gear state, the first oil port G1 and the fourth oil port G4 of the high-low gear control valve are communicated through the second reversing valve 5, and the sixth oil port G6 and the fifth oil port G5 of the high-low gear control valve are communicated through the second reversing valve 5. When the high-low gear control valve is in the low-speed gear state, the first oil port G1 and the second oil port G2 of the high-low gear control valve are communicated through the second reversing valve 5, and the sixth oil port G6 and the third oil port G3 of the high-low gear control valve are communicated through the second reversing valve 5. In this way, the series and parallel conversion of the oil paths of the two motors can be realized, and the switching of the high-speed and low-speed gears can be achieved.

[0054] As another specific embodiment of the high-low gear control valve, as shown in FIG. 2, Figure 2 As shown, the high-low gear control valve can be composed of a third reversing valve 6 and a fourth reversing valve 7. The third reversing valve 6 is connected with the first oil port G1, the fourth oil port G4, the fifth oil port G5 and the sixth oil port G6 of the high-low gear control valve. The fourth reversing valve 7 is connected with the first oil port G1, the second oil port G2, the third oil port G3 and the sixth oil port G6 of the high-low gear control valve. When the high-low gear control valve is in the high-speed gear state, the first oil port G1 and the fourth oil port G4 of the high-low gear control valve are communicated through the third reversing valve 6, and the sixth oil port G6 and the fifth oil port G5 of the high-low gear control valve are communicated through the third reversing valve 6. When the high-low gear control valve is in the low-speed gear state, the first oil port G1 and the second oil port G2 of the high-low gear control valve are communicated through the fourth reversing valve 7, and the sixth oil port G6 and the third oil port G3 of the high-low gear control valve are communicated through the fourth reversing valve 7. The third reversing valve 6 and the fourth reversing valve 7 can be two-position four-way reversing valves, such as two-position four-way electromagnetic reversing valves. The third reversing valve 6 and the fourth reversing valve 7 can be powered on and powered off at the same time, and the functions realized thereby are consistent with those when the second reversing valve 5 is powered on and powered off. Specifically, the third reversing valve 6 can be a normally closed reversing valve, and the fourth reversing valve 7 can be a normally open reversing valve.

[0055] In the above two embodiments, the high-low gear control valve adopts different specific structural forms. As can be known, on the basis of the technical concept of the present application, various different hydraulic valve combinations can also be adopted to form the high-low gear control valve to realize the control of the series and parallel conversion of the oil paths of the two motors by the high-low gear control valve. These simple modifications all belong to the protection scope of the present application.

[0056] In some embodiments, the return oil port T1 of the first directional valve 1 is connected to a return oil line. Further, a third one-way valve 14 is arranged on the return oil line, and the third one-way valve 14 is configured to allow the hydraulic oil output from the return oil port T1 of the first directional valve 1 to flow to the oil tank in one direction. Moreover, a filter 15 is arranged on the return oil line to filter the impurities in the return oil.

[0057] In some embodiments, the traveling hydraulic system further comprises a hydraulic pump 10 connected to the oil inlet port P1 of the first directional valve 1 through an oil inlet line.

[0058] In some embodiments, a flow valve 11 is arranged on the oil inlet line, and the flow valve 11 comprises a first oil port H1, a second oil port H2, and a third oil port H3. The first oil port H1 of the flow valve 11 is connected to the hydraulic pump 10, and the second oil port H2 of the flow valve 11 is connected to the oil inlet port P1 of the first directional valve 1. Further, a steering oil cylinder 13 is arranged and connected to the third oil port H3 of the flow valve 11. Specifically, the third oil port H3 of the flow valve 11 is connected to the steering oil cylinder 13 through a fifth directional valve 12, and the steering oil cylinder 13 is connected to the oil inlet line through the fifth directional valve 12. When the fifth directional valve 12 is in the neutral state, the third oil port H3 of the flow valve 11 is in communication with the oil inlet line through the fifth directional valve 12. When the fifth directional valve 12 is in the left or right state, the piston rod of the steering oil cylinder 13 is controlled to extend or retract, so that the hydraulic oil in the hydraulic chamber of the steering oil cylinder 13 flows into the oil inlet line and then flows to the oil inlet port P1 of the first directional valve 1.

[0059] In some embodiments, the oil inlet line is connected to a brake oil inlet port Br leading to a brake, and the brake oil inlet port Br provides the brake with pressure oil to open the brake before the motor rotates.

[0060] In order to better understand the technical concept of the present application, the following will be described in combination with relatively comprehensive technical features.

[0061] As Figure 1 and Figure 2As shown, the preferred embodiment of the present application provides a walking hydraulic system, comprising a first reversing valve 1, a shunt valve 2, a high-low gear control valve, a hydraulic pump 10, a flow valve 11, a fifth reversing valve 12, a steering oil cylinder 13, a first oil supplement oil way and a second oil supplement oil way, the first reversing valve 1 comprises an oil inlet P1, an oil return T1, a first working oil port E1 and a second working oil port E2, the oil return T1 of the first reversing valve 1 is connected with an oil return oil way, a third one-way valve 14 is arranged on the oil return oil way, the third one-way valve 14 is used to make the hydraulic oil output by the oil return T1 of the first reversing valve 1 flow to the oil tank in one direction, a filter 15 is arranged on the oil return oil way, and is used to filter impurities in the oil return. The hydraulic pump 10 is connected with the oil inlet P1 of the first reversing valve 1 through an oil inlet oil way, the flow valve 11 is arranged on the oil inlet oil way, the flow valve 11 comprises a first oil port H1, a second oil port H2 and a third oil port H3, the first oil port H1 of the flow valve 11 is connected with the hydraulic pump 10, the second oil port H2 of the flow valve 11 is connected with the oil inlet P1 of the first reversing valve 1, the third oil port H3 of the flow valve 11 is connected with the steering oil cylinder 13 through the fifth reversing valve 12, the steering oil cylinder 13 is connected with the oil inlet oil way through the fifth reversing valve 12, and the third oil port H3 of the flow valve 11 is communicated with the oil inlet oil way through the fifth reversing valve 12. The oil inlet oil way is connected with a brake oil inlet Br, the brake oil inlet Br leads to a brake, the oil inlet provides pressure oil for opening the brake, and the brake is unlocked before the motor rotates.The first working oil port E1 of the first reversing valve 1 is connected with the first oil port F1 of the shunt valve 2, and the second working oil port E2 of the first reversing valve 1 is used to be connected with the first oil port D of the first motor 3; the high-low gear control valve comprises a first oil port G1, a second oil port G2, a third oil port G3, a fourth oil port G4, a fifth oil port G5 and a sixth oil port G6, the sixth oil port G6 of the high-low gear control valve is connected with the second oil port B of the second motor 4, the second oil port G2 and the fifth oil port G5 of the high-low gear control valve, the second oil port C of the first motor 3 are connected with the oil return port T1 of the first reversing valve 1 through the first oil supplement oil way, the third oil port G3 of the high-low gear control valve, the first oil port D of the first motor 3 are connected with the second working oil port E2 of the first reversing valve 1, the fourth oil port G4 of the high-low gear control valve is connected with the first oil port A of the second motor 4, the shunt valve 2 comprises a first oil port F1, a second oil port F2 and a third oil port F3, the second oil port F2 of the shunt valve 2 is connected with the first oil port G1 of the high-low gear control valve, and the third oil port F3 of the shunt valve 2 is used to be connected with the first oil port A of the second motor 4; the high-low gear control valve is composed of the second reversing valve 5, the second reversing valve 5 can be a two-position six-way electromagnetic reversing valve, and the second reversing valve 5 is connected with the first oil port G1, the second oil port G2, the third oil port G3, the fourth oil port G4, the fifth oil port G5 and the sixth oil port G6 of the high-low gear control valve respectively; alternatively, the high-low gear control valve can be composed of the third reversing valve 6 and the fourth reversing valve 7, the third reversing valve 6 and the fourth reversing valve 7 can be two-position four-way electromagnetic reversing valves, the third reversing valve 6 is connected with the first oil port G1, the fourth oil port G4, the fifth oil port G5 and the sixth oil port G6 of the high-low gear control valve respectively, and the fourth reversing valve 7 is connected with the first oil port G1, the second oil port G2, the third oil port G3 and the sixth oil port G6 of the high-low gear control valve respectively; the high-low gear control valve has two states of high-speed gear and low-speed gear, when the high-low gear control valve is in the high-speed gear state, the second oil port F2 of the shunt valve 2 is communicated with the first oil port A of the second motor 4 through the high-low gear control valve, the second oil port B of the second motor 4 is communicated with the second oil port C of the first motor 3 through the high-low gear control valve, and the first motor 3 and the second motor 4 are connected in series, when the high-low gear control valve is in the low-speed gear state, the second oil port F2 of the shunt valve 2 is communicated with the second oil port C of the first motor 3 through the high-low gear control valve, the second oil port B of the second motor 4 is communicated with the second working oil port E2 of the first reversing valve 1 through the high-low gear control valve, and the first motor 3 and the second motor 4 are connected in parallel.

[0062] With reference to the embodiment shown in the drawings, Figure 1 The working process of the walking hydraulic system is described, Figure 2 The walking hydraulic system has similar working process, which will not be described here.

[0063] The walking hydraulic system is in high-speed gear

[0064] The second reversing valve 5 is not powered, the two motor oil circuits are in series, the oil flows out from the hydraulic pump 10, through the second oil port H2 and the third oil port H3 of the flow valve 11, the first reversing valve 1, the oil flows into the first oil port Fl of the flow distribution valve 2, half of the total flow rate of the oil flows out from the third oil port F3 of the flow distribution valve 2, the other half of the total flow rate of the oil flows out from the second oil port F2 of the flow distribution valve 2, through the first oil port Gl and the fourth oil port G4 of the second reversing valve 5, and then merges with the oil flowing out from the third oil port F3 of the flow distribution valve 2, and then flows into the first oil port A of the second motor 4, the oil flows out from the second oil port B of the second motor 4, through the sixth oil port G6 and the fifth oil port G5 of the second reversing valve 5, flows into the second oil port C of the first motor 3 of the motor 3, the oil flows out from the first oil port D of the first motor 3, and then flows back to the oil tank through the first reversing valve 1, the third check valve 14 and the filter 15.

[0065] In the high-speed gear state, the oil in the second oil port F2 and the third oil port F3 of the flow distribution valve 2 has merged before (or after) flowing into (or flowing out of) the second motor 4, at this time the system does not need the flow distribution valve 2 to distribute the flow rate for the first motor 3 and the second motor 4. The first reversing valve 1 is used to switch the direction of the oil flowing into the first motor 3 and the second motor 4, so as to realize the forward and reverse rotation control of the motor, so as to make the equipment move forward or backward. The brake inlet port Br leads to the brake, this oil port provides the brake with open pressure oil, and the brake is unlocked before the motor rotates, so as to release the brake on the first motor 3 and the second motor 4. In the two-motor series state, during the equipment driving and steering process, there is a speed difference between the two wheels, which causes the flow rates of the two motors to be inconsistent, at this time the oil which should flow back to the oil tank can be supplemented to the motor with high speed and large flow rate demand through the first check valve 8.

[0066] The walking hydraulic system is in the low-speed gear state

[0067] The second reversing valve 5 is powered, the two motor oil circuits are in parallel, the oil flows out from the hydraulic pump 10, through the second oil port H2 and the third oil port H3 of the flow valve 11, the first reversing valve 1, the oil flows into the first oil port Fl of the flow distribution valve 2, half of the total flow rate of the oil flows out from the third oil port F3 of the flow distribution valve 2, flows into the first oil port A of the second motor 4, the oil flows out from the second oil port B of the second motor 4, through the sixth oil port G6, the third oil port G3 of the second reversing valve 5, the first reversing valve 1, the third check valve 14 and the filter 15, and then flows back to the oil tank; the other half of the total flow rate of the oil flows out from the second oil port F2 of the flow distribution valve 2, through the first oil port Gl and the second oil port G2 of the second reversing valve 5, flows into the second oil port C of the first motor 3 of the motor 3, the oil flows out from the first oil port D of the first motor 3, and then flows back to the oil tank through the first reversing valve 1, the third check valve 14 and the filter 15.

[0068] Wherein, in the parallel state of the first motor 3 and the second motor 4, the flow distribution valve 2 evenly distributes the flow output by the hydraulic pump 10 to the two motors, so that the two motors always have a fixed flow and rotational speed and are not affected by the load of each motor. During the driving and steering process of the device, there is a rotational speed difference between the two wheels, resulting in inconsistent flow of the two motors. At this time, the oil in the six oil tanks should be supplemented to the motor with high rotational speed and large flow demand through the first one-way valve 8 and the second one-way valve 9.

[0069] The present application increases the flow distribution valve anti-slip function on the basis of not affecting the high-low gear function of the existing scissor-type aerial work platform, and innovatively integrates the two functions on one hydraulic control circuit. That is, on the basis of not changing the existing user usage habit, the flow distribution valve is combined with two two-position four-way electromagnetic valves or two-position six-way electromagnetic valves to form an oil path with switchable series-parallel connection of the two motors, so that the flow of the two motors is evenly distributed by a flow distribution valve with a flow distribution ratio of 50:50, so that the two motors have power output during driving, reduces the probability of wheel slip idling leading to no power of other motors, and achieves the purpose of stable flow of the two motors not affected by the load and prevents motor idling due to wheel slip; the two two-position four-way electromagnetic valves or two-position six-way electromagnetic valves are used to switch the oil path, so that the two motor circuits can be switched between series connection and parallel connection, so that the walking system has two gear positions of high speed and low speed, and the walking of the device takes into account the requirements of driving efficiency and climbing ability; the first one-way valve and the second one-way valve are arranged to form a first oil supplementing oil path and a second oil supplementing oil path for supplementing oil to the motor with large flow when the rotational speed of the motor is inconsistent due to the rotational speed difference of the wheels during steering of the device.

[0070] On the basis of the technical scheme of the above-mentioned walking hydraulic system of the present application, the present application further provides an aerial work device, wherein it comprises the walking hydraulic system of any one of the above-mentioned technical schemes. Of course, the walking hydraulic system of the present application is not limited to the aerial work device, but can also be applied to other walking devices that need to switch between high speed and low speed.

[0071] The preferred embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the specific details in the above-mentioned embodiments, and various simple modifications can be made to the technical scheme of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0072] In addition, it should be noted that each specific technical feature described in the above-mentioned specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

[0073] Furthermore, the various embodiments of the present application can be combined with each other, as long as it does not violate the spirit of the present application, and it should be considered as disclosed in the present application.

Claims

1. A walking hydraulic system, characterized in that, The system includes a first directional valve (1), a flow divider valve (2), and a high / low gear control valve. The first directional valve (1) includes an inlet (P1), a return port (T1), a first working port (E1) connected to the first port (F1) of the flow divider valve (2), and a second working port (E2) for connecting to the first port (D) of the first motor (3). The flow divider valve (2) includes the first port (F1), a second port (F2) connected to the high / low gear control valve, and a third port (F3) for connecting to the first port (A) of the second motor (4). The high / low gear control valve has a high-speed gear and a low-speed gear. When the high / low gear control valve is in the high-speed gear state, the second port (F1) of the flow divider valve (2) is open. 2) The high and low gear control valve is connected to the first oil port (A) of the second motor (4), and the second oil port (B) of the second motor (4) is connected to the second oil port (C) of the first motor (3) through the high and low gear control valve, so that the first motor (3) and the second motor (4) are connected in series. When the high and low gear control valve is in the low speed gear state, the second oil port (F2) of the diverter valve (2) is connected to the second oil port (C) of the first motor (3) through the high and low gear control valve, and the second oil port (B) of the second motor (4) is connected to the second working oil port (E2) of the first reversing valve (1) through the high and low gear control valve, so that the first motor (3) and the second motor (4) are connected in parallel. The system also includes a first replenishing oil circuit and a second replenishing oil circuit. The high and low gear control valve includes a first oil port (G1) connected to the second oil port (F2) of the diverter valve (2), a second oil port (G2) connected to the second oil port (C) of the first motor (3), a third oil port (G3) connected to the first oil port (D) of the first motor (3), a fourth oil port (G4) connected to the first oil port (A) of the second motor (4), a fifth oil port (G5) connected to the second oil port (C) of the first motor (3), and a sixth oil port (G6) connected to the second oil port (B) of the second motor (4). The first replenishing oil circuit... One end is connected to the return port (T1) of the first reversing valve (1), and the other end is connected to the oil line between the fifth oil port (G5) of the high and low gear control valve and the second oil port (C) of the first motor (3), so as to replenish oil to the first motor (3) or the second motor (4) when the high and low gear control valve is in the high gear state and the wheel is turning. One end of the second replenishing oil line is connected to the return port (T1) of the first reversing valve (1), and the other end is connected to the first oil port (A) of the second motor (4), so as to replenish oil to the second motor (4) when the high and low gear control valve is in the low gear state and the wheel is turning.

2. The walking hydraulic system according to claim 1, characterized in that, The high / low gear control valve includes a second directional valve (5). The second directional valve (5) is connected to the first oil port (G1), second oil port (G2), third oil port (G3), fourth oil port (G4), fifth oil port (G5), and sixth oil port (G6) of the high / low gear control valve. When the high / low gear control valve is in the high-speed gear state, the first oil port (G1) and its fourth oil port (G4) of the high / low gear control valve are connected through the second directional valve (5), and the sixth oil port (G6) and its fifth oil port (G5) of the high / low gear control valve are connected through the second directional valve (5). When the high / low gear control valve is in the low-speed gear state, the first oil port (G1) and its second oil port (G2) of the high / low gear control valve are connected through the second directional valve (5), and the sixth oil port (G6) and its third oil port (G3) of the high / low gear control valve are connected through the second directional valve (5).

3. The walking hydraulic system according to claim 1, characterized in that, The high / low gear control valve includes a third directional valve (6) and a fourth directional valve (7). The third directional valve (6) is connected to the first port (G1), fourth port (G4), fifth port (G5), and sixth port (G6) of the high / low gear control valve, respectively. The fourth directional valve (7) is connected to the first port (G1), second port (G2), third port (G3), and sixth port (G6) of the high / low gear control valve, respectively. When the high / low gear control valve is in the high-speed gear state, the high / low gear control valve... The first oil port (G1) and its fourth oil port (G4) are connected through the third directional valve (6). The sixth oil port (G6) and its fifth oil port (G5) of the high and low gear control valve are connected through the third directional valve (6). When the high and low gear control valve is in the low speed gear state, the first oil port (G1) and its second oil port (G2) of the high and low gear control valve are connected through the fourth directional valve (7). The sixth oil port (G6) and its third oil port (G3) of the high and low gear control valve are connected through the fourth directional valve (7).

4. The walking hydraulic system according to claim 1, characterized in that, The first oil replenishment circuit is provided with a first check valve (8) for guiding hydraulic oil to flow unidirectionally from the return port (T1) of the first directional valve (1) to the high and low gear control valve, and the second oil replenishment circuit is provided with a second check valve (9) for guiding hydraulic oil to flow unidirectionally from the return port (T1) of the first directional valve (1) to the second motor (4).

5. The walking hydraulic system according to any one of claims 1 to 4, characterized in that, The oil inlet (P1) of the first directional valve (1) is connected to the hydraulic pump (10) through the oil inlet circuit.

6. The walking hydraulic system according to claim 5, characterized in that, A flow valve (11) is provided on the oil inlet line. The flow valve (11) includes a first oil port (H1) connected to the hydraulic pump (10), a second oil port (H2) connected to the oil inlet (P1) of the first directional valve (1), and a third oil port (H3).

7. The walking hydraulic system according to claim 6, characterized in that, The third port (H3) of the flow valve (11) is connected to the steering cylinder (13) through the fifth directional valve (12). The steering cylinder (13) is connected to the oil inlet circuit through the fifth directional valve (12). When the fifth directional valve (12) is in the neutral position, the third port (H3) of the flow valve (11) is connected to the oil inlet circuit through the fifth directional valve (12).

8. The walking hydraulic system according to claim 5, characterized in that, The oil inlet circuit is connected to the brake inlet (Br).

9. The walking hydraulic system according to any one of claims 1 to 4, characterized in that, The return port (T1) of the first reversing valve (1) is connected to the return oil circuit.

10. The walking hydraulic system according to claim 9, characterized in that, A third check valve (14) is installed on the return oil line.

11. The walking hydraulic system according to claim 9, characterized in that, A filter (15) is installed on the return oil line.

12. The walking hydraulic system according to any one of claims 1 to 4, characterized in that, The flow divider valve (2) has a flow divider ratio of 50%:50%.

13. An aerial work platform, characterized in that, The system is equipped with a walking hydraulic system as described in any one of claims 1 to 12.

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