A hydraulic system capable of dual control

Abstract

The invention discloses a hydraulic system capable of dual control, including a double pump provided with a large pump and a small pump, the large pump is used to supply the oil circuit of the main control valve at the turret, the small pump is used to supply the oil circuit of the platform control valve, the main control valve is a large flow manual self-resetting reversing valve, which is reset by a spring and installed on the turret, the hydraulic oil supplied by the large pump directly enters the main control valve, when the hydraulic handle of the main control valve is operated at the turret to change direction, the hydraulic oil enters the motor through the reversing valve to control the lifting and lowering of the hoist; the platform control valve is installed in the working bucket and supplied with oil by the small pump, when the platform control valve is not working, the oil circuit automatically unloads back to the oil tank through the platform control valve; when any reversing valve of the platform control valve changes direction, the hydraulic oil enters the system through the actuator to realize the movement of each action. The reversing valve controls the reversing of the main control valve, thereby controlling the lifting and lowering of the hoist, the system can realize the operation of the turret and the platform working bucket, the control process is simple and easy to use, and the practicability is strong.

Description

Technical Field

[0001] The invention relates to the field of hydraulic systems, and in particular to a hydraulic system capable of dual-control operation. Background Art

[0002] Aerial work vehicles are equipment that transports people to high altitudes for work. They require two controls, namely getting off the vehicle (turret) and the working bucket. Since the working bucket is at the end of the working arm, if control is achieved in the working bucket, the following methods are usually used:

[0003] 1. The electric control valve is installed at the vehicle turret. It can be electrically controlled or manually controlled at the turret. The working bucket is controlled by electric control. The pipeline is simple and easy to implement.

[0004] Disadvantages: 1) The electronic control is unreliable and prone to failure; 2) It is not suitable for insulated high-altitude operations.

[0005] 2. Hydraulic control valve: the valve is installed at the vehicle turret, the hydraulic control handle is installed at the working bucket, and the hydraulic control pipeline enters the working bucket through the boom. This system requires a constant pressure system, and the hydraulic control system requires fast pressure buildup and pressure relief.

[0006] Disadvantages: 1) For longer pipelines, this system has the problem of slow pressure build-up and difficulty in exhausting; 2) The system cost is relatively high.

[0007] 3. Conventional full hydraulic system, that is, a set of multi-way valves is placed on the turret and the platform respectively, and the two sets of multi-way valves are connected in parallel to realize the control of each action, so the platform valve flow is required to be larger and the pipeline is larger.

[0008] Disadvantages: 1) Pipeline layout is difficult; 2) Pipeline pressure loss is large, greatly affected by temperature, and slow in winter; 3) For insulated vehicles, since pipeline insulation is required, the pipeline cannot have steel wire, so the insulating pipe cannot meet the requirements of high pressure and large pipe diameter.

[0009] Based on the above problems, a system is urgently needed to solve the above problems. Summary of the invention

[0010] In view of the above-mentioned technical deficiencies, the purpose of the present invention is to provide a hydraulic system capable of dual control, which can realize operation of both the turret and the platform working bucket, has simple working bucket control and is relatively cost-effective.

[0011] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0012] The present invention provides a hydraulic system capable of dual control, comprising a double pump provided with a large pump and a small pump, wherein the oil outlet of the large pump of the double pump is connected to the P1 port of the main control valve, the main control valve is a manual reversing valve and its spring chamber is provided with two hydraulic control ports, the main control valve comprises a relief valve and a single or multiple reversing valves, the P1 port of the main control valve is connected to the oil inlet of the relief valve and the oil inlet of the reversing valve; the T1 port of the main control valve is connected to the oil return port of the relief valve and the oil return port of the reversing valve, the A and B ports of the reversing valve are connected to the motor, and the oil drain port of the motor is connected to the oil tank through an oil unloading pipeline; the two hydraulic control ports of the reversing valve spring chamber are connected to the platform control The A2 and B2 ports of the valve are connected; the platform control valve includes one or more manual reversing valves, the oil inlet of the manual reversing valve is connected to the P2 port of the platform control valve; the oil return port of the manual reversing valve is connected to the T2 port of the platform control valve; the A2 port of the manual reversing valve is connected to the oil inlet of the second relief valve, the B2 port of the manual reversing valve is connected to the oil inlet of the first relief valve, the oil return port of the first relief valve and the oil return port of the second relief valve are both connected to the T2 port of the platform control valve; the T2 port of the platform control valve is mixed with the T1 port of the main control valve and then flows back to the oil tank, and the P2 port of the platform control valve is connected to the oil outlet of the small pump of the duplex pump.

[0013] Preferably, the two hydraulic control ports of the reversing valve spring chamber are connected to the A2 and B2 ports of the platform control valve through pipelines, and the two pipelines are also connected through damping holes. and damping holes It is connected to the oil tank through the oil unloading pipeline.

[0014] Preferably, the oil from the T2 port of the platform control valve is mixed with the oil from the T1 port of the main control valve and then enters the oil tank through the oil return filter.

[0015] Preferably, the large pump and the small pump in the duplex pump are selected from one of a gear pump, a vane pump, a plunger pump or a mixed pump.

[0016] Preferably, the manual reversing valve is an O-type mid-position function three-position four-way reversing valve.

[0017] The beneficial effects of the present invention are as follows: the system has a simple principle and low cost. In actual use, the pipeline pressure is small, the pipe diameter is small, and it is easy to arrange and install. Therefore, when used on an insulated vehicle, an insulated pipeline without steel wire can be used, which meets the use requirements of the insulated vehicle. At the same time, the reversing of a large-flow manual reversing valve can be controlled remotely to achieve a dual control function. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A hydraulic principle diagram of a dual-controllable hydraulic system provided by an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of the structure of a special equipment for live aerial work provided in an embodiment of the present invention.

[0021] Description of reference numerals:

[0022] 1. Duplex pump, 2. Main control valve, 3. Overflow valve, 4. Reversing valve, 5. Motor, 6. Platform control valve, 7. Manual reversing valve, 8. First overflow valve, 9. Second overflow valve, 10. Insulated pipeline, 11. Oil drain pipeline, 12. Special equipment for live aerial work, 13. Turret, 14. Insulated telescopic arm, 15. Working bucket. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The pole aerial work vehicle is a special equipment for live aerial work12. Figure 2 The equipment has many functions such as lifting, drilling, boom luffing, telescopic, and rotation, and requires all functions except drilling to be realized at the two operating points of the turret 13 and the platform working bucket 15. Since the lifting function has high power and requires a large flow rate, and this vehicle is an insulated vehicle with an insulated telescopic arm 14, conventional control systems cannot realize it. It can be realized by using a hydraulic control valve, but the control is complicated and the price is high. Please refer to the attached Figure 1A hydraulic system capable of dual control in this embodiment includes a double pump 1 provided with a large pump and a small pump, the oil outlet of the large pump of the double pump 1 is connected to the P1 port of the main control valve 2, the main control valve 2 is a manual reversing valve and its spring chamber is provided with two hydraulic control ports, and the reversing valve can be driven to reverse by external hydraulic power, the main control valve 2 includes a relief valve 3 and a reversing valve 4, the P1 port of the main control valve 2 is connected to the oil inlet of the relief valve 3 and the oil inlet of the reversing valve 4; the T1 port of the main control valve 2 is connected to the oil return port of the relief valve 3 and the oil return port of the reversing valve 4, the A and B ports of the reversing valve 4 are connected to the motor 5, and the oil drain port of the motor 5 is connected to the oil tank through the oil unloading pipeline 11; the two hydraulic control ports of the spring chamber of the reversing valve 4 are connected to the platform control The A2 and B2 ports of valve 6 are connected to realize the remote control of the platform control valve 6 to the main control valve 2. The platform control valve 6 includes two manual reversing valves 7. The oil inlet of the manual reversing valve 7 is connected to the P2 port of the platform control valve 6; the oil return port of the manual reversing valve 7 is connected to the T2 port of the platform control valve 6; the A2 port of the manual reversing valve 7 is connected to the oil inlet of the second relief valve 9, and the B2 port of the manual reversing valve 7 is connected to the oil inlet of the first relief valve 8. The oil return port of the first relief valve 8 and the oil return port of the second relief valve 9 are both connected to the T2 port of the platform control valve 6; the T2 port of the platform control valve 6 is mixed with the T1 port of the main control valve 2 and then flows back to the oil tank, and the P2 port of the platform control valve 6 is connected to the small pump oil outlet of the duplex pump 1

[0025] The two hydraulic control ports of the spring chamber of the reversing valve 4 are connected to the A2 and B2 ports of the platform control valve 6 through insulating pipelines, and the two insulating pipelines are also connected through damping holes. and damping holes The oil unloading pipeline 11 is connected to the oil tank.

[0026] The oil from the T2 port of the platform control valve 6 and the T1 port of the main control valve 2 are mixed and then enter the oil tank through the return oil filter.

[0027] The large pump and the small pump in the double pump 1 are selected from one of a gear pump, a vane pump, a plunger pump or a mixed pump.

[0028] The large pump of the double pump 1 is used to supply the oil circuit of the main control valve 2 at the turret 13, and the small pump is used to supply the platform control valve 6; the main control valve 2 controls the lifting and lowering, and the switching of the main control valve 2: one is to switch the direction through the hydraulic operating handle of this valve; the other is to push the main control valve 2 to switch the direction through the A2 and B2 oil circuits of the platform control valve 6. Since the switching pressure of the main control valve 2 is relatively small, the secondary pressure limiting valves, the first relief valve 8 and the second relief valve 9, are set in the A2 and B2 oil circuits of the platform control valve 6 to limit the size of the switching pressure of the main control valve 2.

[0029] The main control valve 2 is a large-flow manual self-resetting reversing valve, which is reset by a spring and installed on the turret. The hydraulic oil supplied by the large pump directly enters the main control valve 2. When the hydraulic handle of the main control valve 2 is operated to change direction at the turret, the hydraulic oil enters the motor 5 through the reversing valve 4. The motor 5 drives the lifting winch to control the lifting and lowering. When A2 is connected to the pressure oil, the main control valve 2 is reversed upward, and the A port is the pressure oil, which enters the motor 5 to realize the lifting; when B2 is connected to the pressure oil, the main control valve 2 is reversed downward, and the B port is the pressure oil, which enters the motor 5 to realize the lifting and lowering; the overflow valve 3 controls the maximum lifting pressure, that is, the maximum lifting amount; the reversing valve 4 controls the forward and reverse rotation of the motor 5.

[0030] The platform control valve 6 is installed in the working bucket 15 and is supplied with oil by a small pump. When the platform control valve 6 is not working, the oil circuit automatically unloads back to the oil tank through the platform control valve 6; when any reversing valve of the platform control valve 6 is reversed, hydraulic oil enters the system to realize the movement of each action, and the manual reversing valve 7 controls the reversing of the main control valve 2, thereby controlling the lifting and lowering.

[0031] The manual reversing valve 7 uses an O-type three-position four-way reversing valve with a mid-position function. When the manual reversing valve 7 is reversed by the handle, the hydraulic oil enters the spring chamber of the main control valve 2 through the A2 or B2 oil circuit, pushing the main control valve 2 to change direction. Since the spring chamber is a fixed volume, the A2 or B2 oil circuit builds up pressure after entering the spring chamber of the main control valve 2, pushing the main control valve 2 to change direction, and no hydraulic oil flows, so the hydraulic oil from the small pump to A2 or B2 must overflow back to the oil tank through the secondary pressure limiting valve 8 or 9, or through the damping hole and Return to the oil tank through the oil unloading line.

[0032] When the handle of the reversing valve 7 returns to the middle position, in order to prevent the return oil back pressure from affecting the main control valve 2, the reversing valve 7 must be an O-type function. However, when the reversing valve returns to the middle position, the O-type function is prone to pressure buildup at the A2 or B2 ports, so a throttle plug is set on the A2 and B2 oil lines. and throttle plug Used to release the pressure of ports A2 and B2, thereby releasing the spring chamber pressure of the main control valve 2 to ensure the reset of the main control valve 2; throttle plug and throttle plug The size of needs to be matched according to the flow of ports A2 and B2. If it is too large, it is easy to fail to build up pressure, and the main control valve 2 cannot be switched; if it is too small, the pressure of ports A2 and B2 cannot be released in time, affecting the lifting accuracy. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A hydraulic system capable of dual control, characterized in that: The invention comprises a double pump (1) provided with a large pump and a small pump, wherein the oil outlet of the large pump of the double pump (1) is connected to the P1 port of the main control valve (2), the main control valve (2) is a manual reversing valve and its spring chamber is provided with two hydraulic control ports, the main control valve (2) comprises a relief valve (3) and a single or multiple reversing valves (4), the P1 port of the main control valve (2) is connected to the oil inlet of the relief valve (3) and the oil inlet of the reversing valve (4); the T1 port of the main control valve (2) is connected to the oil return port of the relief valve (3) and the oil return port of the reversing valve (4), the A and B ports of the reversing valve (4) are connected to the motor (5), and the oil drain port of the motor (5) is connected to the oil tank through the oil unloading pipeline (11); the two hydraulic control ports of the spring chamber of the reversing valve (4) are connected to the A2 and B ports of the platform control valve (6), and the oil drain port of the motor (5) is connected to the oil tank through the oil unloading pipeline (11); the two hydraulic control ports of the spring chamber of the reversing valve (4) are connected to the A2 and B ports of the platform control valve (6). 2 ports are connected; the platform control valve (6) comprises one or more manual reversing valves (7); the oil inlet of the manual reversing valve (7) is connected to the P2 port of the platform control valve (6); the oil return port of the manual reversing valve (7) is connected to the T2 port of the platform control valve (6); the A2 port of the manual reversing valve (7) is connected to the oil inlet of the second relief valve (9), the B2 port of the manual reversing valve (7) is connected to the oil inlet of the first relief valve (8), the oil return port of the first relief valve (8) and the oil return port of the second relief valve (9) are both connected to the T2 port of the platform control valve (6); the T2 port of the platform control valve (6) and the T1 port of the main control valve (2) are mixed and then flow back to the oil tank, and the P2 port of the platform control valve (6) is connected to the oil outlet of the small pump of the double pump (1).

2. A dual-controllable hydraulic system as claimed in claim 1, characterized in that: The two hydraulic control ports of the spring chamber of the reversing valve (4) are respectively connected to the A2 and B2 ports of the platform control valve (6) through pipelines. The two pipelines are also connected to the oil tank through the damping hole φ1 and the damping hole φ2 via the oil unloading pipeline (11).

3. A dual-controllable hydraulic system as claimed in claim 1, characterized in that: The oil from the T2 port of the platform control valve (6) and the T1 port of the main control valve (2) is mixed and enters the oil tank through the oil return filter.

4. A dual-controllable hydraulic system as claimed in claim 1, characterized in that: The large pump and the small pump in the double pump (1) are selected from one of a gear pump, a vane pump, a plunger pump or a mixed pump.

5. A dual-controllable hydraulic system as claimed in claim 1, characterized in that: The manual reversing valve (7) is an O-type three-position four-way reversing valve with a mid-position function.

Images