CN114198353A

CN114198353A - Scissor fork type aerial work platform hydraulic control system

Info

Publication number: CN114198353A
Application number: CN202111668508.5A
Authority: CN
Inventors: 陈德义; 沈超
Original assignee: Hangzhou Hangcha High Altitude Equipment Co ltd; Hangcha Group Co Ltd
Current assignee: Hangzhou Hangcha High Altitude Equipment Co ltd; Hangcha Group Co Ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2022-03-18

Abstract

The invention discloses a scissor type aerial work platform hydraulic control system, which comprises: a main oil inlet path; a main oil return path; a steering circuit including a steering oil inlet path; the lifting loop comprises a lifting oil inlet path; a walking loop including a walking oil inlet path; the oil inlet P1 of the first reversing valve is connected with a main oil inlet path, the oil return port T1 of the first reversing valve is connected with the main oil return path, and the working oil port B1 of the first reversing valve is connected with a lifting oil inlet path; an oil inlet P2 of the flow priority valve is connected with a working oil port A1, a working oil port A2 is connected with a steering oil inlet way, and a working oil port B2 is connected with a walking oil inlet way; a lifting hydraulic cylinder; an oil inlet P3 of the proportional reversing valve is connected with a lifting oil inlet path, and a working oil port A3 of the proportional reversing valve is connected with a rodless cavity of a lifting hydraulic cylinder; the proportional reversing valve is positioned at a first station, and a first oil passage between the oil inlet P3 and the working oil port A3 is communicated; the proportional reversing valve is located at a second station, the opening-adjustable second oil passage between the oil inlet P3 and the working oil port A3 is communicated, and the descending speed is adjustable.

Description

Scissor fork type aerial work platform hydraulic control system

Technical Field

The invention relates to the technical field of aerial work platform control, in particular to a scissor-type aerial work platform hydraulic control system.

Background

In the industries such as the building industry, the logistics industry, airports, railways and the like, the demand for scissor-type aerial work platforms is increasing day by day. The scissor type aerial work platform mainly aims at leasing markets, and due to the fact that the use working conditions of different industries are different, higher requirements are put forward on the technology of the aerial work platform.

The existing scissor-fork type aerial work platform falls by means of dead weight, the falling speed of the platform is controlled by damping, and due to the fact that the use requirements of different customers are inconsistent, the falling damping needs to be frequently replaced, and inconvenience is brought to the use of different customers.

Therefore, how to make the descending speed of the scissor-type aerial work platform meet the use requirements of different customers is a problem to be solved urgently by the technical personnel in the field at present.

Disclosure of Invention

In view of this, the present invention provides a scissor-type aerial work platform hydraulic control system, in which the descending speed of the aerial work platform is adjustable to meet the use requirements of different customers.

In order to achieve the above purpose, the invention provides the following technical scheme:

a scissor type aerial work platform hydraulic control system comprises:

a main oil inlet path for supplying hydraulic oil;

the main oil return path is used for supplying hydraulic oil to return to the oil tank;

the steering loop is used for controlling the steering of the aerial work platform and comprises a steering oil inlet path;

the lifting loop is used for controlling the lifting of the aerial work platform and comprises a lifting oil inlet path;

the walking loop is used for controlling the aerial work platform to walk and comprises a walking oil inlet path;

the first reversing valve comprises an oil inlet P1, an oil return port T1, a working oil port A1 and a working oil port B1, the oil inlet P1 is connected with the main oil inlet path, the oil return port T1 is connected with the main oil return path, and the working oil port B1 is connected with the lifting oil inlet path; when the first reversing valve is in a first station, the oil inlet P1 is communicated with the working oil port A1, and the oil return port T1 is communicated with the working oil port B1; when the first reversing valve is positioned at a second station, the oil inlet P1 is communicated with the working oil port B1, and the oil return port T1 is communicated with the working oil port A1;

the flow priority valve comprises an oil inlet P2, a working oil port A2 and a working oil port B2, the oil inlet P2 is connected with the working oil port A1, the working oil port A2 is connected with the steering oil inlet way, and the working oil port B2 is connected with the walking oil inlet way; when the high-altitude operation platform turns and walks simultaneously, hydraulic oil is preferably supplied to the working oil port A2;

the lifting hydraulic cylinder is used for driving the aerial work platform to lift;

the proportional reversing valve comprises an oil inlet P3 and a working oil port A3, the oil inlet P3 is connected with the lifting oil inlet path, and the working oil port A3 is connected with a rodless cavity of the lifting hydraulic cylinder; when the proportional reversing valve is in a first station, the first oil passage between the oil inlet P3 and the working oil port A3 is communicated; when the proportional reversing valve is in a second station, the second oil passage between the oil inlet P3 and the working oil port A3 is communicated, and the opening degree of the second oil passage is adjustable.

Preferably, the lifting hydraulic cylinder comprises a first lifting hydraulic cylinder and a second lifting hydraulic cylinder, a first explosion-proof valve is arranged between the working oil port A3 and the first lifting hydraulic cylinder, and a second explosion-proof valve is arranged between the working oil port A3 and the second lifting hydraulic cylinder.

Preferably, when the lifting hydraulic cylinder needs to descend, the switching action of the second explosion-proof valve lags behind the switching action of the proportional reversing valve for a preset time.

Preferably, the walking circuit includes:

a first hydraulic motor connected to a first oil passage and a second oil passage;

a second hydraulic motor connected to a third oil passage and a fourth oil passage;

the second reversing valve comprises an oil inlet P4, an oil return port T4, a working oil port A4 and a working oil port B4, the oil inlet P4 is connected with the walking oil inlet path, and the oil return port T4 is connected with the main oil return path; when the second reversing valve is in a first station, the oil inlet P4 is communicated with the working oil port A4, and the oil return port T4 is communicated with the working oil port B4; when the second reversing valve is positioned at a second station, the oil inlet P4 is communicated with the working oil port B4, and the oil return port T4 is communicated with the working oil port A4;

the third reversing valve comprises an oil inlet P5, an oil return port T5, a working oil port A5 and a working oil port B5, the working oil port A5 is connected with the third oil way, and the working oil port B5 is connected with the second oil way; when the third reversing valve is in a first station, the oil inlet P5 is communicated with the working oil port A5, and the oil return port T5 is communicated with the working oil port B5; when the third reversing valve is in a second station, the oil inlet P5 and the oil return port T5 are closed, and the working oil port A5 is communicated with the working oil port B5;

a first end of the fifth oil path is connected with the working oil port A4, a second end of the fifth oil path is respectively connected with the first oil path and the oil inlet P5, and the fifth oil path is provided with a first balance valve;

and a first end of the sixth oil path is connected with the working oil port B4, a second end of the sixth oil path is respectively connected with the fourth oil path and the oil return port T5, and the second oil path is provided with a second balance valve.

Preferably, the first end of the needle valve is connected with the fifth oil path, the second end of the needle valve is connected with the sixth oil path, and the connecting position of the first end of the needle valve and the fifth oil path is located between the first balance valve and the second end of the fifth oil path; and the connection position of the second end of the needle valve and the sixth oil path is positioned between the second balance valve and the second end of the sixth oil path.

Preferably, the second oil path is connected to the main oil return path through a seventh oil path, and the seventh oil path is provided with a first check valve, so that hydraulic oil flows from the main oil return path to the second oil path; the third oil path is connected with the main oil return path through an eighth oil path, and the eighth oil path is provided with a second one-way valve so that hydraulic oil flows to the third oil path from the main oil return path.

Preferably, the walking oil inlet path is connected with a braking oil path, the braking oil path is provided with a one-way throttle valve, the one-way throttle valve is used for throttling and regulating the speed of hydraulic oil flowing back from the braking oil path to the walking oil inlet path, the braking oil path is connected with a manual pump of the aerial work platform, and the manual pump is connected with a brake of the aerial work platform.

Preferably, the manual pump is connected with the brake oil path through a manual pump oil pipe, and the manual pump oil pipe is provided with a bending part.

Preferably, the method further comprises the following steps:

an inlet of the first overflow valve is connected with the main oil inlet path, and an outlet of the first overflow valve is connected with the main oil return path;

an inlet of the second overflow valve is connected with the lifting oil inlet path, and an outlet of the second overflow valve is connected with the main oil return path;

an inlet of the third overflow valve is connected with the steering oil inlet path, and an outlet of the third overflow valve is connected with the walking oil inlet path;

and the inlet of the fourth overflow valve is connected with the joint of the braking oil path and the walking oil inlet path, and the outlet of the fourth overflow valve is connected with the oil inlet P4.

Preferably, the first direction changing valve, the flow priority valve, the second direction changing valve, the third direction changing valve, the first balance valve, the second balance valve, the needle valve, the first check valve, the second check valve, the one-way throttle valve, the first overflow valve, the second overflow valve, the third overflow valve and the fourth overflow valve are integrated in a same valve block, a valve body of the valve block is a cast valve body, and a valve core of the valve block is a plate-type electromagnetic valve core.

When the scissor-type aerial work platform needs to descend, the first reversing valve is located at the first station, the proportional reversing valve is located at the second station, at the time, the working oil port B1 of the first reversing valve is communicated with the oil return port T1, the second oil duct between the oil inlet P3 of the proportional reversing valve and the working oil port A3 is communicated, the aerial work platform compresses hydraulic oil in the rodless cavity of the lifting hydraulic cylinder by means of self weight, the hydraulic oil in the rodless cavity of the lifting hydraulic cylinder enters the proportional reversing valve, flows out of the oil inlet P3 of the proportional reversing valve through the second oil duct of the proportional reversing valve, then flows into the first reversing valve from the working oil port B1, and finally flows into the main oil return path from the oil return port T1 of the first reversing valve, and finally flows back to the oil tank. Because the opening degree of the second oil duct of the proportional reversing valve is adjustable, the descending speed of the aerial work platform can be adjusted by adjusting the opening degree of the second oil duct of the proportional reversing valve in the descending process of the aerial work platform, so that the descending speed of the aerial work platform can be adjusted to meet the use requirements of different customers.

In addition, the proportional reversing valve with not very high response speed is adopted to adjust the descending speed of the aerial work platform, and the cost performance is high.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a control schematic diagram of a hydraulic control system of a scissor-type aerial work platform according to an embodiment of the present invention.

The reference numerals in fig. 1 are as follows:

1 is a main oil inlet passage, 2 is a main oil return passage, 3 is a steering oil inlet passage, 4 is a lifting oil inlet passage, 5 is a traveling oil inlet passage, 6 is a first directional control valve, 7 is a flow priority valve, 8 is a lifting hydraulic cylinder, 9 is a proportional directional control valve, 10 is a first explosion-proof valve, 11 is a second explosion-proof valve, 12 is a first hydraulic motor, 13 is a second hydraulic motor, 14 is a first oil passage, 15 is a second oil passage, 16 is a third oil passage, 17 is a fourth oil passage, 18 is a second directional control valve, 19 is a third directional control valve, 20 is a fifth oil passage, 21 is a first balance valve, 22 is a sixth oil passage, 23 is a second balance valve, 24 is a needle valve, 25 is a seventh oil passage, 26 is a first one-way valve, 27 is an eighth oil passage, 28 is a second one-way valve, 29 is a braking oil passage, 30 is a one-way throttle valve, 31 is a manual pump, 32 is a brake, 33 is a manual pump, 34 is a first overflow valve, 35 is a second overflow valve, Reference numeral 36 denotes a third relief valve, 37 denotes a fourth relief valve, 38 denotes a fourth direction switching valve, 39 denotes a fourth check valve, 40 denotes a hydraulic pump, 41 denotes a motor, 42 denotes a second filter, 43 denotes a third filter, 44 denotes an air filter, and 45 denotes an oil tank.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The core of the invention is to provide a scissor type hydraulic control system for an aerial work platform, and the descending speed of the aerial work platform is adjustable so as to meet the use requirements of different customers.

Referring to fig. 1, a control schematic diagram of a hydraulic control system of a scissor-type aerial work platform according to an embodiment of the present invention is shown.

The invention provides a hydraulic control system of a scissor-type aerial work platform, which comprises a main oil inlet path 1, a main oil return path 2, a steering loop, a lifting loop, a walking loop, a first reversing valve 6, a flow priority valve 7, a lifting hydraulic cylinder 8 and a proportional reversing valve 9.

Wherein, the main oil inlet 1 is used for supplying hydraulic oil; the main oil return path 2 is used for supplying hydraulic oil to return to the oil tank 45; the steering loop is used for controlling the aerial work platform to steer and comprises a steering oil inlet path 3; the lifting loop is used for controlling the lifting of the aerial work platform and comprises a lifting oil inlet path 4; the walking loop is used for controlling the aerial work platform to walk and comprises a walking oil inlet path 5; the first reversing valve 6 comprises an oil inlet P1, an oil return port T1, a working oil port A1 and a working oil port B1, the oil inlet P1 is connected with the main oil inlet path 1, the oil return port T1 is connected with the main oil return path 2, and the working oil port B1 is connected with an inlet of the lifting oil inlet path 4; when the first reversing valve 6 is in the first station, the oil inlet P1 is communicated with the working oil port A1, and the oil return port T1 is communicated with the working oil port B1; when the first reversing valve 6 is in the second station, the oil inlet P1 is communicated with the working oil port B1, and the oil return port T1 is communicated with the working oil port A1; the flow priority valve 7 comprises an oil inlet P2, a working oil port A2 and a working oil port B2, the oil inlet P2 is connected with the working oil port A1, the working oil port A2 is connected with the steering oil inlet path 3, and the working oil port B2 is connected with the walking oil inlet path 5; when the high-altitude operation platform turns and walks simultaneously, hydraulic oil is preferably supplied to the working oil port A2; the lifting hydraulic cylinder 8 is used for driving the aerial work platform to lift; the proportional reversing valve 9 comprises an oil inlet P3 and a working oil port A3, the oil inlet P3 is connected with the lifting oil inlet path 4, and the working oil port A3 is connected with a rodless cavity of the lifting hydraulic cylinder 8; when the proportional reversing valve 9 is in the first station, the first oil passage between the oil inlet P3 and the working oil port A3 is communicated; when the proportional reversing valve 9 is in the second station, the second oil passage between the oil inlet P3 and the working oil port A3 is communicated, and the opening degree of the second oil passage is adjustable.

It can be seen that the first directional control valve 6 mainly controls the flow direction of the hydraulic oil, when the first directional control valve 6 is in the first station, the oil inlet P1 is communicated with the working oil port a1, after the hydraulic oil supplied from the main oil inlet path 1 enters the oil inlet P1, the hydraulic oil flows into the oil inlet P2 of the flow priority valve 7 from the working oil port a1, a part of the hydraulic oil entering the oil inlet P2 enters the steering oil inlet path 3 from the working oil port a2 of the flow priority valve 7, and the steering oil inlet path 3 supplies the steering loop with the hydraulic oil, so as to realize the steering of the aerial work platform; meanwhile, the other part of the hydraulic oil entering the oil inlet P2 enters the walking oil inlet path 5 from the working oil port B2 of the flow priority valve 7, and the walking oil inlet path 5 supplies the walking circuit with the hydraulic oil, so that the walking of the aerial work platform is realized. At the moment, the working oil port B1 of the first reversing valve 6 is communicated with the oil return port T1, and oil return is realized by the lifting hydraulic cylinder, namely, the aerial work platform cannot rise under the working condition, so that the aerial work platform is prevented from rising in the walking and/or steering process.

When the first reversing valve 6 is in the second station, the oil inlet P1 is communicated with the working oil port B1, hydraulic oil supplied by the main oil inlet path 1 enters the oil inlet P1 and flows into the lifting oil inlet path 4 from the working oil port B1, and the lifting oil inlet path 4 supplies hydraulic oil to the lifting loop, so that the lifting of the aerial work platform is realized; at the moment, the working oil port A1 of the first reversing valve 6 is communicated with the oil return port T1, oil return is realized by the steering loop and the walking loop, the aerial work platform cannot walk or steer, and the aerial work platform is prevented from walking or steering in the lifting process. That is, the lifting process, the steering process and the walking process of the aerial work platform are independent and can not be carried out in parallel.

The proportional reversing valve 9 is mainly used for adjusting the descending speed of the aerial work platform. When the aerial work platform needs to be lifted, the first reversing valve 6 is located at the second station, the proportional reversing valve 9 is located at the first station, at this time, the work oil port B1 of the first reversing valve 6 is communicated with the oil inlet P1, the first oil duct between the oil inlet P3 of the proportional reversing valve 9 and the work oil port B3 is communicated, hydraulic oil supplied by the main oil inlet 1 enters the oil inlet P1 of the first reversing valve 6, flows out of the work oil port B1 of the first reversing valve 6 and flows into the oil inlet P3 of the proportional reversing valve 9, flows out of the work oil port A3 of the proportional reversing valve 9 through the first oil duct of the proportional reversing valve 9, and finally flows into the rodless cavity of the lifting hydraulic cylinder 8 to push the piston rod of the lifting hydraulic cylinder 8 to extend, so that the aerial work platform rises.

When the scissor-type aerial work platform needs to descend, the first reversing valve 6 is located at the first station, the proportional reversing valve 9 is located at the second station, at the moment, the working oil port B1 of the first reversing valve 6 is communicated with the oil return port T1, the second oil duct between the oil inlet P3 of the proportional reversing valve 9 and the working oil port A3 is communicated, the aerial work platform compresses the hydraulic oil in the rodless cavity of the lifting hydraulic cylinder 8 by means of self weight, after the hydraulic oil in the rodless cavity of the lifting hydraulic cylinder 8 enters the proportional reversing valve 9, the hydraulic oil flows out of the oil inlet P3 of the proportional reversing valve 9 through the second oil duct of the proportional reversing valve 9, then flows into the first reversing valve 6 from the working oil port B1, and finally flows into the main oil return path 2 from the oil return port T1 of the first reversing valve 6, and finally the hydraulic oil flows back to the oil tank 45. Because the opening degree of the second oil duct of the proportional reversing valve 9 is adjustable, in the descending process of the aerial work platform, the descending speed of the aerial work platform can be adjusted by adjusting the opening degree of the second oil duct of the proportional reversing valve 9, so that the descending speed of the aerial work platform can be adjusted to meet the use requirements of different customers.

In addition, the proportional reversing valve 9 with not very high response speed is adopted in the embodiment to adjust the descending speed of the aerial work platform, and the cost performance is high.

In order to adjust the opening degree of the second oil passage of the proportional directional valve 9, on the basis of the above embodiment, the proportional directional valve further comprises a control handle, the control handle is connected with a controller, and the controller controls the opening degree of the second oil passage according to the action amplitude of the control handle. That is to say, in this embodiment, the control handle is additionally provided to facilitate the operation of an operator, and when the operator operates the control handle, the controller controls the opening amount of the second oil passage of the proportional directional valve 9 according to the action amplitude of the control handle, so as to achieve the purpose of adjusting the descending speed of the aerial work platform, and the controller is convenient to operate and can adjust the descending speed of the aerial work platform at any time and any place.

In order to avoid the jamming of the proportional directional valve 9 due to the poor cleanliness of the hydraulic oil in the rodless cavity, a first filter (not shown in fig. 1) is arranged between the working oil port a3 of the proportional directional valve 9 and the rodless cavity of the hydraulic cylinder 8 on the basis of the above-mentioned embodiment. Therefore, when the aerial work platform descends, the hydraulic oil in the rodless cavity of the lifting hydraulic cylinder 8 enters the proportional reversing valve 9 after being filtered by the first filter, the cleanliness of the hydraulic oil entering the proportional reversing valve 9 can be improved, the proportional reversing valve 9 is prevented from being blocked due to impurities in the hydraulic oil and the like, and the fault rate of the proportional reversing valve 9 can be reduced.

On the basis of the above-described embodiment, the first filter is integrated with the proportional directional valve 9 in consideration of the convenience of assembly. In other words, the first filter is built in the proportional directional valve 9, so that the proportional directional valve 9 becomes the proportional directional valve 9 with the filtering function, the hydraulic oil can be automatically cleaned, and the proportional directional valve 9 can be directly installed at a required position during assembly, thereby bringing convenience to the overall assembly.

In addition, when the aerial work platform ascends, in order to avoid the backflow of the hydraulic oil, and improve the ascending stability of the aerial work platform, on the basis of the above embodiment, the first oil passage of the proportional directional valve 9 is provided with the third check valve, so that the hydraulic oil in the first oil passage flows from the oil inlet P3 to the working oil port A3. That is to say, the setting of third check valve for hydraulic oil in the first oil duct can only flow to working oil port A3 from oil inlet P3, and can not flow to oil inlet P3 from working oil port A3, thereby can promote aerial work platform at the stationarity of the in-process that rises, avoid producing undulant in the in-process that rises, moreover, after aerial work platform rises to target in place, still have the effect of pressurize, improve the security.

Further, in order to provide sufficient power for the aerial work platform to ascend and to improve safety, the hydraulic cylinder 8 includes a first hydraulic cylinder and a second hydraulic cylinder, a first explosion-proof valve 10 is disposed between the hydraulic port A3 and the first hydraulic cylinder, and a second explosion-proof valve 11 is disposed between the hydraulic port A3 and the second hydraulic cylinder. That is, the first lifting hydraulic cylinder and the second lifting hydraulic cylinder are used for driving the aerial work platform to lift simultaneously in the embodiment. It will be appreciated that the working port a3 of the proportional directional valve 9 is connected to the rodless chambers of the first and second hydraulic rams respectively.

In addition, in view of the fact that when the aerial work platform descends at a low speed, the displacement of the control handle is small, the proportional directional valve 9 has a dead zone, when the dead zone of the proportional directional valve 9 does not exist yet, when the hydraulic oil in the rodless cavity of the hydraulic lifting cylinder 8 flows into the proportional directional valve 9 from the second anti-explosion valve 11, the situation that the flow is unstable can occur, and the phenomenon that the aerial work platform shakes during the descending process is caused. That is to say, when aerial work platform need descend, at first make proportional reversing valve 9 move earlier for the second oil duct of proportional reversing valve 9 has a stable opening volume earlier, makes second explosion-proof valve 11 move again, just can make aerial work platform begin to descend, avoids appearing the unstable phenomenon of flow, makes aerial work platform speed stability better when the proportion descends, promotes aerial work platform's lift and experiences sense and travelling comfort.

In addition, in order to avoid the situation that the aerial work platform descends too fast to cause stalling and descending, on the basis of the above embodiment, the second explosion-proof valve 11 is internally provided with a first throttle valve to control the descending speed of the second lifting hydraulic cylinder. It should be noted that in the present embodiment, the first throttle is disposed in the second explosion-proof valve 11, so as to prevent the aerial work platform from falling and stalling after the second explosion-proof valve 11 is stuck.

In the above embodiments, the specific structure of the traveling circuit is not limited as long as the aerial work platform can travel. However, in order to solve the problem that the conventional aerial work platform tends to slide down when descending a slope, the traveling circuit includes the first hydraulic motor 12, the second hydraulic motor 13, the first oil passage 14, the second oil passage 15, the third oil passage 16, the fourth oil passage 17, the second direction changing valve 18, the third direction changing valve 19, the fifth oil passage 20, the sixth oil passage 22, the first balance valve 21, and the second balance valve 23 in addition to the above-described embodiment.

Specifically, the first hydraulic motor 12 and the second hydraulic motor 13 are used for driving the aerial work platform to walk (including forward traveling and backward traveling), the first hydraulic motor 12 is connected with the first oil passage 14 and the second oil passage 15, and the second hydraulic motor 13 is connected with the third oil passage 16 and the fourth oil passage 17. The second reversing valve 18 comprises an oil inlet P4, an oil return port T4, a working oil port A4 and a working oil port B4, the oil inlet P4 is connected with an outlet of the walking oil inlet path 5, and the oil return port T4 is connected with the main oil return path 2; when the second reversing valve 18 is in the first station, the oil inlet P4 is communicated with the working oil port A4, and the oil return port T4 is communicated with the working oil port B4; when the second reversing valve 18 is in the second station, the oil inlet P4 is communicated with the working oil port B4, and the oil return port T4 is communicated with the working oil port A4. The third reversing valve 19 comprises an oil inlet P5, an oil return port T5, a working oil port A5 and a working oil port B5, the working oil port A5 is connected with the third oil way 16, and the working oil port B5 is connected with the second oil way 15; when the third reversing valve 19 is in the first station, the oil inlet P5 is communicated with the working oil port A5, and the oil return port T5 is communicated with the working oil port B5; when the third reversing valve 19 is in the second station, the oil inlet P5 and the oil return port T5 are both closed, and the working oil port A5 is communicated with the working oil port B5; a first end of the fifth oil path 20 is connected with the working oil port A4, a second end of the fifth oil path 20 is respectively connected with the first oil path 14 and the oil inlet P5, and the first balance valve 21 is arranged between the first end and the second end of the fifth oil path 20; a first end of the sixth oil passage 22 is connected to the working oil port B4, a second end of the sixth oil passage 22 is connected to the fourth oil passage 17 and the oil return port T5, respectively, and the second balance valve 23 is provided between the first end and the second end of the sixth oil passage 22.

It should be noted that the first hydraulic motor 12 and the second hydraulic motor 13 can respectively rotate forward and backward, which defines that when the first hydraulic motor 12 and the second hydraulic motor 13 rotate forward, the aerial work platform travels forward, and when the first hydraulic motor 12 and the second hydraulic motor 13 rotate backward, the aerial work platform moves backward; of course, the reverse control may be used, that is, when the first hydraulic motor 12 and the second hydraulic motor 13 rotate in the forward direction, the aerial work platform moves backward, and when the first hydraulic motor 12 and the second hydraulic motor 13 rotate in the reverse direction, the aerial work platform moves forward. The second direction switching valve 18 is used to control the forward rotation and the reverse rotation of the first hydraulic motor 12 and the second hydraulic motor 13; the third direction valve 19 is used to control the series and parallel connection of the first hydraulic motor 12 and the second hydraulic motor 13.

Specifically, when the first directional control valve 6 is at the first station, the second directional control valve 18 is at the first station, and the third directional control valve 19 is at the first station, after the hydraulic oil supplied from the main oil inlet passage 1 enters the oil inlet P1, the hydraulic oil flows into the oil inlet P2 of the flow priority valve 7 from the working oil port a1, the hydraulic oil entering the oil inlet P2 enters the traveling oil inlet passage 5 from the working oil port B2 of the flow priority valve 7, then enters the oil inlet P4 from the traveling oil inlet passage 5, and then flows out from the working oil port a4, after the hydraulic oil flowing out from the working oil port a4 flows through the first balance valve 21, the hydraulic oil enters the first oil passage 14 and the oil inlet P5 through the fifth oil passage 20, the hydraulic oil entering the first forward rotation oil passage 14 finally enters the first hydraulic motor 12 to drive the first hydraulic motor 12, the hydraulic oil entering the oil inlet P5 flows out from the working oil port a5, enters the third oil passage 16, and finally enters the second hydraulic motor 13 through the third oil passage 16, to drive the second hydraulic motor 13 to rotate forward. It can be seen that the hydraulic oil supplied by the traveling oil inlet 5 is divided into two parts and respectively enters the first hydraulic motor 12 and the second hydraulic motor 13, so that the first hydraulic motor 12 and the second hydraulic motor 13 work in parallel, and the high-altitude operation platform can travel forwards at a high speed.

In the process, the hydraulic oil of the first hydraulic motor 12 enters the working oil port B5 through the second oil path 15, flows out from the oil return port T5, enters the working oil port B4 after passing through the sixth oil path 22 and the second balance valve 23, flows out from the oil return port T4 to the main oil return path 2, and finally flows back to the oil tank 45 through the main oil return path 2, so that oil return of the first hydraulic motor 12 is realized. Meanwhile, the hydraulic oil of the second hydraulic motor 13 enters the sixth oil path 22 through the fourth oil path 17, passes through the sixth oil path 22 and the second balance valve 23, enters the working oil port B4, flows out of the main oil return path 2 through the oil return port T4, and finally flows back to the oil tank 45 through the main oil return path 2, so that oil return of the second hydraulic motor 13 is realized.

When the first directional control valve 6 is at the first station, the second directional control valve 18 is at the first station, and the third directional control valve 19 is at the second station, after the hydraulic oil supplied from the main oil inlet path 1 enters the oil inlet P1, the hydraulic oil flows into the oil inlet P2 of the flow priority valve 7 from the working oil port a1, the hydraulic oil entering the oil inlet P2 enters the walking oil inlet path 5 from the working oil port B2 of the flow priority valve 7, then enters the oil inlet P4 from the walking oil inlet path 5, and flows out from the working oil port a4, because the oil inlet P5 is closed at this time, the hydraulic oil flowing out from the working oil port a4 flows through the first balance valve 21, then enters only the first oil path 14 through the fifth oil path 20, the hydraulic oil entering the first oil path 14 finally enters the first hydraulic motor 12 to drive the first hydraulic motor 12, the hydraulic oil flowing out from the first hydraulic motor 12 enters the working oil path B5 through the second oil path 15, and at this time, because the working oil port B5 is communicated with the working oil port a5, therefore, the hydraulic oil flows from the working port B5 to the working port a5, flows out from the working port a5, passes through the third oil passage 16, flows into the second hydraulic motor 13, and drives the second hydraulic motor 13 to rotate forward. It can be seen that after the hydraulic oil supplied by the traveling oil inlet 5 enters the first hydraulic motor 12, the hydraulic oil enters the second hydraulic motor 13 through the first hydraulic motor 12, that is, the first hydraulic motor 12 and the second hydraulic motor 13 are connected in series to work, so that the aerial work platform travels forwards at a high speed.

In this process, the hydraulic oil flowing out of the second hydraulic motor 13 enters the sixth oil passage 22 through the fourth oil passage 17, passes through the sixth oil passage 22 and the second balance valve 23, enters the working oil port B4, flows out of the main oil return passage 2 through the oil return port T4, and finally flows back to the oil tank 45 through the main oil return passage 2, so that oil return of the first hydraulic motor 12 and the second hydraulic motor 13 is realized.

Similarly, when the first directional control valve 6 is at the first station, the second directional control valve 18 is at the second station, and the third directional control valve 19 is at the first station, after the hydraulic oil supplied from the main oil inlet 1 enters the oil inlet P1, the hydraulic oil flows into the oil inlet P2 of the flow priority valve 7 from the working oil port a1, the hydraulic oil entering the oil inlet P2 enters the walking oil inlet 5 from the working oil port B2 of the flow priority valve 7, then enters the oil inlet P4 from the walking oil inlet 5, flows out from the working oil port B4, after the hydraulic oil flowing out from the working oil port B4 passes through the second balance valve 23, the hydraulic oil respectively enters the fourth oil passage 17 and the oil return port T5 through the sixth oil passage 22, the hydraulic oil entering the fourth oil passage 17 finally enters the second hydraulic motor 13 to drive the second hydraulic motor 13 to rotate reversely, the hydraulic oil entering the oil return port T5 flows out from the working oil port B5, enters the second oil passage 15, and finally enters the first hydraulic motor 12 through the second oil passage 15, to drive the first hydraulic motor 12 in reverse. It can be seen that the hydraulic oil supplied by the traveling oil inlet 5 is divided into two parts and respectively enters the first hydraulic motor 12 and the second hydraulic motor 13, so that the first hydraulic motor 12 and the second hydraulic motor 13 work in parallel, and the high-altitude operation platform turtle moves backwards at a high speed.

In this process, the hydraulic oil of the first hydraulic motor 12 enters the fifth oil path 20 through the first oil path 14, passes through the fifth oil path 20 and the first balance valve 21, enters the working oil port a4, flows out of the main oil return path 2 from the oil return port T4, and finally flows back to the oil tank 45 through the main oil return path 2, so that oil return of the first hydraulic motor 12 is realized. Hydraulic oil of the second hydraulic motor 13 enters the working oil port a5 through the third oil path 16, flows out from the oil inlet P5, enters the working oil port a4 through the fifth oil path 20 and the first balance valve 21, flows out to the main oil return path 2 through the oil return port T4, and finally flows back to the oil tank 45 through the main oil return path 2, so that oil return of the second hydraulic motor 13 is realized.

When the first directional control valve 6 is at the first station, the second directional control valve 18 is at the second station, and the third directional control valve 19 is at the second station, after the hydraulic oil supplied from the main oil inlet path 1 enters the oil inlet P1, the hydraulic oil flows into the oil inlet P2 of the flow priority valve 7 from the working oil port a1, the hydraulic oil entering the oil inlet P2 enters the walking oil inlet path 5 from the working oil port B2 of the flow priority valve 7, then enters the oil inlet P4 from the walking oil inlet path 5, and flows out from the working oil port B4, because the oil return port T5 is closed at this time, the hydraulic oil flowing out from the working oil port B4 flows through the second balance valve 23, and then only enters the fourth oil path 17 through the sixth oil path 22, the hydraulic oil entering the fourth oil path 17 finally enters the second hydraulic motor 13 to drive the second hydraulic motor 13 to rotate reversely, the hydraulic oil flowing out from the second hydraulic motor 13 enters the working oil port a2 through the third oil path 16, and at this time, because the working oil port a5 is communicated with the working oil port B5, therefore, the hydraulic oil flows from the working port a5 to the working port B5, flows out from the working port B5, passes through the second oil passage 15, flows into the first hydraulic motor 12, and drives the first hydraulic motor 12 to rotate in reverse. It can be seen that after the hydraulic oil supplied from the traveling oil inlet passage 5 enters the second hydraulic motor 13, the hydraulic oil enters the first hydraulic motor 12 through the second hydraulic motor 13, that is, the first hydraulic motor 12 and the second hydraulic motor 13 are connected in series to work, so that the aerial work platform moves backward at a high speed.

In this process, the hydraulic oil flowing out of the first hydraulic motor 12 enters the fifth oil passage 20 through the first oil passage 14, passes through the fifth oil passage 20 and the first balance valve 21, enters the working oil port a4, flows out of the main oil return passage 2 through the oil return port T4, and finally flows back to the oil tank 45 through the main oil return passage 2, so that oil return of the first hydraulic motor 12 and the second hydraulic motor 13 is realized.

Therefore, in the four processes (high-altitude platform cruise forward running, high-speed forward running, cruise backward running and high-speed backward running), either the first balance valve 21 or the second balance valve 23 exists in the oil return paths of the first hydraulic motor 12 and the second hydraulic motor 13, and the backpressure of the oil return paths of the first hydraulic motor 12 and the second hydraulic motor 13 is increased through the first balance valve 21 and the second balance valve 23, so that the oil return resistance of the first hydraulic motor 12 and the second hydraulic motor 13 is relatively large. Therefore, no matter which process brakes the aerial work platform, the braking performance and the braking stability can be improved, so that the vehicle does not shake forwards and backwards, and the braking is stable. Particularly, when the aerial work platform is braked on a slope, even if the brake 32 is still closed, the braking force is small and is not enough to keep braking on the vehicle, the vehicle can be braked by utilizing the large oil return resistance of the first hydraulic motor 12 and the second hydraulic motor 13, therefore, when the aerial work platform is braked on the slope, the aerial work platform can be prevented from sliding down the slope, and the aerial work platform cannot roll over when braked on the slope with the maximum height.

In one embodiment, as shown in FIG. 1, the second diverter valve 18 is a three-position, four-way diverter valve, the first position of the second diverter valve 18 is the left position, the second position of the second diverter valve 18 is the right position, and the neutral position of the second diverter valve 18 is preferably H-shaped.

It can be understood that, due to the addition of the first and second balance valves 21 and 23, when the power source of the main oil feed line 1 is out of order or runs short of power, when oil is manually pumped to the brake 32 by the manual pump 31 of the aerial work platform, so that the brake 32 releases the brake for towing, since the hydraulic oil is subjected to the resistance of the first and second balance valves 21 and 23, so that the oil return resistance of the first and second hydraulic motors 12 and 13 is large, in this case, it is difficult to push or pull the vehicle, so that the aerial work platform cannot move or pull, and in order to solve the technical problem, on the basis of the above embodiment, the hydraulic control device further comprises a needle valve 24, wherein a first end of the needle valve 24 is connected with the fifth oil path 20, a second end of the needle valve 24 is connected with the sixth oil path 22, and a connecting position of the first end of the needle valve 24 and the fifth oil path 20 is located between the first balance valve 21 and the second end of the fifth oil path 20; the connection position of the second end of the needle valve 24 and the sixth oil passage 22 is between the second balance valve 23 and the second end of the sixth oil passage 22.

That is, in the present embodiment, by adding the needle valve 24, when the power source of the main oil inlet 1 fails or is in power shortage, the needle valve 24 is opened, so that the circuits of the first hydraulic motor 12 and the second hydraulic motor 13 are connected in series, and hydraulic oil circulates inside the first hydraulic motor 12 and the second hydraulic motor 13 without passing through the first balance valve 21 and the second balance valve 23, and therefore, when the brake 32 releases the brake and pulls the aerial work platform, the aerial work platform can be easily pushed, so that the aerial work platform can be moved to a fixed maintenance site or a charging site.

In addition, it should be noted that the first hydraulic motor 12 and the second hydraulic motor 13 are respectively located on two sides of the frame of the aerial work platform, when the aerial work platform runs at a high speed and turns, the rotation speeds of the first hydraulic motor 12 and the second hydraulic motor 13 are different, which causes the oil supply amount of the first hydraulic motor 12 and the second hydraulic motor 13 to be different, and when the oil supply amount required by the first hydraulic motor 12 and the second hydraulic motor 13 is not reached, the first hydraulic motor 12 or the second hydraulic motor 13 will suck air into the first hydraulic motor 12 or the second hydraulic motor 13, which generates noise, and in order to solve the technical problem, on the basis of the above embodiment, the second oil path 15 is connected with the main oil return path 2 through the seventh oil path 25, and the seventh oil path 25 is provided with the first one-way valve 26, so that the hydraulic oil flows from the main oil return path 2 to the second oil path 15; the third oil passage 16 is connected to the main return passage 2 through an eighth oil passage 27, and the eighth oil passage 27 is provided with a second check valve 28 for allowing hydraulic oil to flow from the main return passage 2 to the third oil passage 16. As can be seen from the above, when the aerial work platform travels forwards at a high speed or moves backwards at a high speed, the first hydraulic motor 12 and the second hydraulic motor 13 work in series, so that the seventh oil path 25 is provided with the first check valve 26, so that the oil tank 45 supplies hydraulic oil to the second oil path 15 during steering, and the first hydraulic motor 12 and the second hydraulic motor 13 supply hydraulic oil when the aerial work platform moves backwards at a high speed; and through set up second check valve 28 in eighth oil circuit 27, realize supplementing hydraulic oil to third oil circuit 16 through oil tank 45 during turning to for when high altitude construction platform goes forward at a high speed supplementing hydraulic oil to first hydraulic motor 12 and second hydraulic motor 13, avoid first hydraulic motor 12 and second hydraulic motor 13 because of the oil supply is insufficient inhales the air, consequently, the noise can be reduced.

In addition, in order to prevent the hydraulic oil of the brake 32 of the aerial work platform from being quickly released to cause sudden braking, on the basis of the above embodiment, the traveling oil inlet 5 is connected with the brake oil passage 29, the brake oil passage 29 is provided with the one-way throttle valve 30, the one-way throttle valve 30 is used for throttling and regulating the speed of the hydraulic oil flowing back from the brake oil passage 29 to the traveling oil inlet 5, the brake oil passage 29 is connected with the manual pump 31, and the manual pump 31 is connected with the brake 32. It can be understood that the brake 32 of the aerial work platform is a spring brake, during the running process of the vehicle, the hydraulic oil in the main oil inlet 1 enters the brake oil path 29, enters the manual pump 31 through the one-way valve of the one-way throttle valve 30, enters the spring brake 32 from the manual pump 31, and pushes the spring of the brake 32 to compress, so that the brake 32 releases the brake, and the normal running of the aerial work platform is ensured. When the brake 32 is needed to brake the aerial work platform, the hydraulic oil in the brake 32 flows back to the manual pump 31, then enters the brake oil path 29 from the manual pump 31, further enters the walking oil inlet path 5 through the throttle valve of the one-way throttle valve 30, and finally flows back to the oil tank 45. Because the one-way throttle valve 30 can provide buffer resistance, sudden braking caused by quick release of hydraulic oil of the brake 32 can be prevented, and braking impact caused by sudden closing of the brake 32 can be reduced.

In addition, when the power system of the main oil inlet 1 has a fault, if the aerial work platform is not started for a long time, the hydraulic oil in the oil passages of the first hydraulic motor 12 and the second hydraulic motor 13 returns to the oil tank 45, at this time, the manual pump 31 is used for self-priming and pumping oil, and oil is difficult to be pumped from the oil tank 45, that is, the hydraulic oil of the manual pump 31 cannot be pumped into the brake 32, so that the brake cannot be released, and the aerial work platform cannot be pulled or moved.

It can be understood that, because the manual pump oil pipe 33 has a bent portion, when a power system of the main oil inlet path 1 fails, the hydraulic oil in the section of the oil pipe from the bent portion to the manual pump 31 of the manual pump oil pipe 33 can be prevented from returning to the oil tank 45, so that a certain amount of hydraulic oil is stored in the section of the oil pipe from the bent portion to the manual pump 31 of the manual pump oil pipe 33, and therefore the hydraulic oil can be pumped manually by the manual pump 31, and the hydraulic oil in the section of the oil pipe from the bent portion to the manual pump 31 of the manual pump oil pipe 33 enters the brake pump, so that the brake 32 can be opened easily, the brake is released, and the aerial work platform can be pulled or moved.

In addition, on the basis of the above embodiment, the fuel tank further includes a first overflow valve 34, a second overflow valve 35, a third overflow valve 36, and a fourth overflow valve 37, wherein an inlet of the first overflow valve 34 is connected to the main oil inlet path 1, and an outlet of the first overflow valve 34 is connected to the main oil return path 2; an inlet of the second overflow valve 35 is connected with the lifting oil inlet path 4, and an outlet of the second overflow valve 35 is connected with the main oil return path 2; the inlet of the third overflow valve 36 is connected with the steering oil inlet path 3, and the outlet of the third overflow valve 36 is connected with the walking oil inlet path 5; the inlet of the fourth spill valve 37 is connected to the junction of the brake oil path 29 and the traveling oil supply path 5, and the outlet of the fourth spill valve 37 is connected to the oil inlet P4. It can be understood that the first relief valve 34 can regulate the maximum pressure output from the main oil inlet 1 to the whole hydraulic system to ensure the safety of the hydraulic control system. The second overflow valve 35 is capable of adjusting the maximum pressure at which the hydraulic lift cylinder 8 is lifted. The third relief valve 36 can regulate the maximum pressure of the steering circuit. The fourth relief valve 37 can ensure that the hydraulic oil in the walking oil inlet path 5 first reaches the pressure value set by the fourth relief valve 37 before entering the oil inlet P4 (i.e. the hydraulic oil enters the first hydraulic motor 12 and the second hydraulic motor 13) so as to completely open the brake 32 and release the brake, thus avoiding the shaking of the aerial work platform when the aerial work platform travels at a low pressure, preventing the pressure at which the brake 32 is completely opened from being reached when the aerial work platform travels at a low pressure, and causing the shaking of the aerial work platform and the stopping of the walking when the aerial work platform travels due to the unstable braking resistance of the brake 32 to the aerial work platform.

Further, in consideration of the convenience of assembly, on the basis of the above embodiment, the first direction changing valve 6, the flow priority valve 7, the second direction changing valve 18, the third direction changing valve 19, the first balance valve 21, the second balance valve 23, the needle valve 24, the first check valve 26, the second check valve 28, the check throttle valve 30, the first relief valve 34, the second relief valve 35, the third relief valve 36, and the fourth relief valve 37 are integrated into the same valve block, a valve body of the valve block is a cast valve body, and a valve core of the valve block is a plate-type electromagnetic valve core. It can be understood that the first reversing valve 6, the flow priority valve 7, the second reversing valve 18, the third reversing valve 19, the first balance valve 21, the second balance valve 23, the needle valve 24, the first check valve 26, the second check valve 28, the one-way throttle valve 30, the first overflow valve 34, the second overflow valve 35, the third overflow valve 36 and the fourth overflow valve 37 are integrated into the same valve block, so that the valves can be prevented from being arranged independently when a hydraulic control system of a scissor-type aerial work platform is assembled, and the assembly is convenient. In addition, the valve body of the valve block is a cast valve body, so that an internal oil channel of the valve block is superior to a machined part, the resistance of the oil channel is small, and the energy consumption is low. And the valve core of the plate-type electromagnetic valve is used as the valve core in the valve block, so that the cost is low, the supply time is short, and the market demand can be conveniently met.

In addition, as shown in fig. 1, in order to facilitate the control of the steering of the aerial work platform, the steering loop includes a steering cylinder 46 and a fourth directional valve 38, the steering cylinder 46 includes a first rod cavity and a second rod cavity, the fourth directional valve 38 includes an oil inlet P6, an oil return port T6, a working oil port a6 and a working oil port B6, the oil inlet P6 is connected to the steering oil inlet path 3, the oil return port T6 is connected to the walking oil inlet path 5, a fourth check valve 39 is disposed between the oil return port T6 and the walking oil inlet path 5, the fourth check valve 39 allows hydraulic oil to flow from the oil return port T6 to the walking oil inlet path 5 only, but not vice versa, the working oil port a6 is connected to the first rod cavity, and the working oil port B6 is connected to the second rod cavity. The fourth reversing valve 38 is a three-position four-way valve, when the fourth reversing valve 38 is in the left position, the oil inlet P6 is communicated with the working oil port A6, and the oil return port T6 is communicated with the working oil port B6, so that the left rotation of the aerial work platform can be realized; when the fourth reversing valve 38 is positioned at the right position, the oil inlet P6 is communicated with the working oil port B6, and the oil return port T6 is communicated with the working oil port A6, so that the aerial work platform can rotate rightwards; when the fourth reversing valve 38 is located at the middle position, the oil inlet P6 is communicated with the oil return port T6, the working oil port a6 and the working oil port B6 are both closed, and at this time, the aerial work platform is not steered, so that the hydraulic oil flowing out of the flow priority valve 7 can fully enter the walking loop.

In order to control the stability of the steering, a second throttle valve is preferably arranged between the working oil port A6 and the first rod cavity; and a third throttle valve is arranged between the working oil port B6 and the second rod cavity.

Further, the fourth direction valve 38, the fourth check valve 39, the second throttle valve, and the third throttle valve may also be all integrated into the above-described valve block for further convenience of assembly.

It should be noted that, in each of the above embodiments, the main oil inlet path 1 only needs to be connected to any hydraulic pressure source with stable pressure, and as a preferable scheme, on the basis of the above embodiments, an oil inlet of the main oil inlet path 1 is connected to a motor-pump set for providing hydraulic power. That is, the present embodiment provides the main oil inlet path 1 with hydraulic power through the motor-pump set.

In one embodiment, the motor-pump assembly includes a hydraulic pump 40 and an electric motor 41 connected to the hydraulic pump 40. Preferably, a second filter 42 is connected to an inlet of the hydraulic pump 40 to ensure cleanliness of the hydraulic oil entering the hydraulic pump 40.

Preferably, an air filter 44 is further provided in an oil tank 45 for supplying an oil source to the hydraulic pump 40.

In addition, the main oil return 2 is preferably provided with a third filter 43 to ensure the cleanliness of the hydraulic oil that is returned to the oil tank 45.

It is further noted that, in the present specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

The embodiments are described in a progressive manner in the specification, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The hydraulic control system of the scissor-type aerial work platform provided by the invention is described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims

1. The utility model provides a cut fork aerial working platform hydraulic control system which characterized in that includes:

a main oil inlet passage (1) for supplying hydraulic oil;

a main oil return path (2) for returning the hydraulic oil to the oil tank (45);

the steering loop is used for controlling the steering of the aerial work platform and comprises a steering oil inlet path (3);

the lifting loop is used for controlling the lifting of the aerial work platform and comprises a lifting oil inlet path (4);

the walking loop is used for controlling the aerial work platform to walk and comprises a walking oil inlet path (5);

the first reversing valve (6) comprises an oil inlet P1, an oil return port T1, a working oil port A1 and a working oil port B1, the oil inlet P1 is connected with the main oil inlet path (1), the oil return port T1 is connected with the main oil return path (2), and the working oil port B1 is connected with the lifting oil inlet path (4); when the first reversing valve (6) is in a first station, the oil inlet P1 is communicated with the working oil port A1, and the oil return port T1 is communicated with the working oil port B1; when the first reversing valve (6) is in a second station, the oil inlet P1 is communicated with the working oil port B1, and the oil return port T1 is communicated with the working oil port A1;

the flow priority valve (7) comprises an oil inlet P2, a working oil port A2 and a working oil port B2, the oil inlet P2 is connected with the working oil port A1, the working oil port A2 is connected with the steering oil inlet path (3), and the working oil port B2 is connected with the walking oil inlet path (5); when the high-altitude operation platform turns and walks simultaneously, hydraulic oil is preferably supplied to the working oil port A2;

the lifting hydraulic cylinder (8) is used for driving the aerial work platform to lift;

the proportional reversing valve (9) comprises an oil inlet P3 and a working oil port A3, the oil inlet P3 is connected with the lifting oil inlet path (4), and the working oil port A3 is connected with a rodless cavity of the lifting hydraulic cylinder (8); when the proportional reversing valve (9) is in a first station, the first oil passage between the oil inlet P3 and the working oil port A3 is communicated; when the proportional reversing valve (9) is in a second station, the second oil channel between the oil inlet P3 and the working oil port A3 is communicated, and the opening degree of the second oil channel is adjustable.

2. A scissor type aerial work platform hydraulic control system according to claim 1, wherein the lifting hydraulic cylinder (8) comprises a first lifting hydraulic cylinder and a second lifting hydraulic cylinder, a first explosion-proof valve (10) is arranged between the working port A3 and the first lifting hydraulic cylinder, and a second explosion-proof valve (11) is arranged between the working port A3 and the second lifting hydraulic cylinder.

3. A scissor aerial work platform hydraulic control system according to claim 2, wherein the switching of the second anti-explosion valve (11) lags behind the switching of the proportional reversing valve (9) for a preset period of time when the hydraulic lift cylinder (8) needs to be lowered.

4. A scissor type aerial work platform hydraulic control system according to any one of claims 1 to 3 wherein the walking circuit comprises:

a first hydraulic motor (12) to which a first oil passage (14) and a second oil passage (15) are connected;

a second hydraulic motor (13) to which a third oil passage (16) and a fourth oil passage (17) are connected;

the second reversing valve (18) comprises an oil inlet P4, an oil return port T4, a working oil port A4 and a working oil port B4, the oil inlet P4 is connected with the walking oil inlet path (5), and the oil return port T4 is connected with the main oil return path (2); when the second reversing valve (18) is in a first station, the oil inlet P4 is communicated with the working oil port A4, and the oil return port T4 is communicated with the working oil port B4; when the second reversing valve (18) is in a second station, the oil inlet P4 is communicated with the working oil port B4, and the oil return port T4 is communicated with the working oil port A4;

the third reversing valve (19) comprises an oil inlet P5, an oil return port T5, a working oil port A5 and a working oil port B5, the working oil port A5 is connected with the third oil way (16), and the working oil port B5 is connected with the second oil way (15); when the third reversing valve (19) is in a first station, the oil inlet P5 is communicated with the working oil port A5, and the oil return port T5 is communicated with the working oil port B5; when the third reversing valve (19) is in a second station, the oil inlet P5 and the oil return port T5 are closed, and the working oil port A5 is communicated with the working oil port B5;

a fifth oil path (20), wherein a first end of the fifth oil path (20) is connected with the working oil port A4, a second end of the fifth oil path (20) is respectively connected with the first oil path (14) and the oil inlet P5, and the fifth oil path (20) is provided with a first balance valve (21);

the first end of the sixth oil way (22) is connected with the working oil port B4, the second end of the sixth oil way (22) is respectively connected with the fourth oil way (17) and the oil return port T5, and the second oil way (15) is provided with a second balance valve (23).

5. A scissor type hydraulic control system for an aerial work platform according to claim 4, further comprising a needle valve (24), wherein a first end of the needle valve (24) is connected with the fifth oil path (20), a second end of the needle valve (24) is connected with the sixth oil path (22), and a connecting position of the first end of the needle valve (24) and the fifth oil path (20) is located between the first balance valve (21) and the second end of the fifth oil path (20); the connection position of the second end of the needle valve (24) and the sixth oil path (22) is located between the second balance valve (23) and the second end of the sixth oil path (22).

6. A scissor type aerial work platform hydraulic control system according to claim 5, wherein the second oil path (15) is connected with the main oil return path (2) through a seventh oil path (25), and the seventh oil path (25) is provided with a first check valve (26) so that hydraulic oil flows from the main oil return path (2) to the second oil path (15); the third oil path (16) is connected with the main oil return path (2) through an eighth oil path (27), and the eighth oil path (27) is provided with a second one-way valve (28) so that hydraulic oil flows to the third oil path (16) from the main oil return path (2).

7. A scissor type hydraulic control system for an aerial work platform according to claim 6, wherein the walking oil inlet passage (5) is connected with a brake oil passage (29), the brake oil passage (29) is provided with a one-way throttle valve (30), the one-way throttle valve (30) is used for throttling and regulating the speed of hydraulic oil flowing back from the brake oil passage (29) to the walking oil inlet passage (5), the brake oil passage (29) is connected with a hand pump (31) of the aerial work platform, and the hand pump (31) is connected with a brake (32) of the aerial work platform.

8. A scissor type aerial work platform hydraulic control system according to claim 7, wherein the manual pump (31) is connected with the brake oil path (29) through a manual pump oil pipe (33), and the manual pump oil pipe (33) is provided with a bent portion.

9. A scissor-type aerial work platform hydraulic control system as claimed in claim 7 further comprising:

an inlet of the first overflow valve (34) is connected with the main oil inlet path (1), and an outlet of the first overflow valve (34) is connected with the main oil return path (2);

an inlet of the second overflow valve (35) is connected with the lifting oil inlet path (4), and an outlet of the second overflow valve (35) is connected with the main oil return path (2);

an inlet of the third overflow valve (36) is connected with the steering oil inlet path (3), and an outlet of the third overflow valve (36) is connected with the walking oil inlet path (5);

and the inlet of the fourth overflow valve (37) is connected with the joint of the brake oil path (29) and the walking oil inlet path (5), and the outlet of the fourth overflow valve (37) is connected with the oil inlet P4.

10. A scissor type aerial work platform hydraulic control system according to claim 9, wherein the first directional control valve (6), the flow priority valve (7), the second directional control valve (18), the third directional control valve (19), the first balance valve (21), the second balance valve (23), the needle valve (24), the first check valve (26), the second check valve (28), the throttle check valve (30), the first overflow valve (34), the second overflow valve (35), the third overflow valve (36) and the fourth overflow valve (37) are integrated in a same valve block, a valve body of the valve block is a cast valve body, and a valve core of the valve block is a plate type electromagnetic valve core.