Aerial work platform applying gravity lowering speed compensation control system

Abstract

The application discloses a kind of aerial work platforms of application gravity under speed compensation control system, including hydraulic oil tank, gear pump, system overflow valve, lifting proportional valve, lifting electromagnetic reversing valve, falling proportional valve, check valve, luffing cylinder, falling electromagnetic reversing valve and overflow valve, the falling electromagnetic reversing valve is the valve of control switch quantity, falling proportional valve is the valve of control analog quantity, the opening of falling proportional valve determines the oil return speed of the large cavity hydraulic oil of luffing cylinder, when platform drops, the pressure difference before and after proportional valve is guaranteed unchanged by compensator, and the same proportion valve core opening degree.The application is realized when platform drops by using the platform gravity drop system of gravity drop valve with compensation valve, the pressure difference before and after proportional electromagnetic valve is guaranteed unchanged by compensator, the same proportion valve core opening degree, no matter how much platform load drops speed, realizes more optimal speed adjustability, safety and comfort.

Description

TECHNICAL FIELD

[0001] The application relates to a scissor-type aerial work platform, in particular to an aerial work platform applying a gravity lowering speed compensation control system. BACKGROUND

[0002] Among many engineering machines, a platform lowering system is one of important components of manned aerial work products, and compared with a walking system, the platform lowering system determines lowering operation, comfort and stability of the whole platform.

[0003] A platform gravity lowering system of an existing off-road scissor-type aerial work platform mainly opens an electromagnetic valve by providing a voltage to the electromagnetic valve on a luffing cylinder, and at this time, gravity can be used to realize falling, and falling speed is changed by changing a valve core opening of a proportional electromagnetic valve, but the platform gravity lowering system has obvious differences in falling speed under the same valve core opening when different loads are on the platform, especially when the platform load is heavy, the falling speed is fast, the platform gravity lowering system has certain safety hazards, and speed adjustability and comfort are poor.

[0004] When the platform falling action is performed, the load on the working platform also directly affects the falling speed of the platform, so that under the premise that the same proportional valve core opening is the same, the falling speed of the platform has great differences under the conditions of empty load and full load. SUMMARY

[0005] The application aims to provide an aerial work platform applying a gravity lowering speed compensation control system.

[0006] The technical scheme is that the application is an aerial work platform applying a gravity lowering speed compensation control system, which comprises a hydraulic oil tank, a gear pump, a system overflow valve, a lifting proportional valve, a lifting electromagnetic reversing valve, a falling proportional valve, a one-way valve, a luffing cylinder, a falling electromagnetic reversing valve and an overflow valve, the falling electromagnetic reversing valve is a valve for controlling switching quantity, the falling proportional valve is a valve for controlling analog quantity, and the opening of the falling proportional valve determines the oil return speed of the hydraulic oil in the large cavity of the luffing cylinder, when the platform is lowered, the pressure difference before and after the proportional valve is kept unchanged and the proportional valve core opening is kept the same through a compensator.

[0007] Further, the proportional valve and the lifting electromagnetic reversing valve are powered at the same time, the lifting electromagnetic reversing valve is reversed to the left side, the engine drives the gear pump to rotate, and the gear pump sucks oil from the hydraulic oil tank to provide hydraulic oil for the lifting action.

[0008] Further, the oil in the hydraulic oil tank reaches the P end of the lifting electromagnetic reversing valve through the lifting proportional valve, then reaches the A end of the lifting electromagnetic reversing valve, then reaches the one-way valve through the hydraulic pipeline, and finally reaches the large cavity of the luffing cylinder directly through the falling electromagnetic reversing valve.

[0009] Further, the oil in the luffing cylinder makes the cylinder rod extend and retract, and performs the platform lifting and falling action.

[0010] Further, the lower lifting proportional valve cannot be electrified, the lifting electromagnetic reversing valve, the falling proportional valve and the falling electromagnetic reversing valve are electrified at the same time, the falling electromagnetic reversing valve is fully opened, the hydraulic oil in the large cavity of the luffing cylinder reaches the falling proportional valve through the falling electromagnetic reversing valve, and then reaches the T end of the lifting electromagnetic reversing valve from the B end of the lifting electromagnetic reversing valve through the pipeline to return to the oil tank.

[0011] Further, the opening degree of the valve port of the falling proportional valve is determined by the size of the handle angle.

[0012] Beneficial effects: compared with the prior art, the present application has the following remarkable advantages:

[0013] (1) The platform is completely lowered by gravity, the opening and closing of the platform falling are controlled by controlling the opening and closing of the electromagnetic valve, the fuel consumption during falling can be saved, the vehicle endurance and continuous working time are significantly improved, and more convenient and efficient service is provided for customers;

[0014] (2) The process of gravity descent is not affected by the load, the descent process is more stable and comfortable, and the user experience is better;

[0015] (3) The electromagnetic valve for gravity descent is a proportional valve, which can adjust the speed of falling, and provides high-quality products for users. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The working principle diagram of the present application. DETAILED DESCRIPTION

[0017] The technical solutions of the present application will be further described below in combination with the drawings.

[0018] As shown in the accompanying Figure 1 The device of the present application includes a hydraulic oil tank 1, a gear pump 2, a system overflow valve 3, a lifting proportional valve 4, a lifting electromagnetic reversing valve 5, a falling proportional valve 6, a one-way valve 7, a luffing cylinder 8, a falling electromagnetic reversing valve 9 and an overflow valve 10. The falling electromagnetic reversing valve 9 is a control switch valve, the falling proportional valve 6 is a control analog valve, the opening of the falling proportional valve 6 determines the return oil speed of the large cavity hydraulic oil of the luffing cylinder 8, and when the platform is lowered, the pressure difference before and after the proportional valve is kept unchanged and the valve core opening ratio is kept the same through the compensator.

[0019] When the lifting action is performed, the lifting proportional valve 4 and the electromagnetic reversing valve 5 are powered at the same time, the lifting electromagnetic reversing valve 5 is reversed to the left side, the engine drives the gear pump 2 to rotate, the gear pump sucks oil from the hydraulic oil tank 1 to provide hydraulic oil for the lifting action, the hydraulic oil reaches the P end of the lifting electromagnetic reversing valve 5 through the lifting proportional valve 4, then reaches the A end of the lifting electromagnetic reversing valve 5, then reaches the single-way valve 7 through the hydraulic pipeline, then reaches the falling electromagnetic reversing valve 9, and then directly reaches the large cavity of the variable amplitude oil cylinder 8, so that the cylinder rod of the variable amplitude oil cylinder 8 is extended, and the lifting action of the platform is performed.

[0020] When the lowering action is performed, the lifting proportional valve 4 is not powered, the lifting electromagnetic reversing valve 5, the falling proportional valve 6 and the falling electromagnetic reversing valve 9 are powered at the same time, wherein the lifting electromagnetic reversing valve 5 is an on-off valve, the valve is fully open, the falling proportional valve 6 is an analog valve, and the valve opening size is determined by the handle angle size. At this time, the hydraulic oil in the large cavity of the variable amplitude oil cylinder 8 reaches the falling proportional valve 6 through the lifting electromagnetic reversing valve 5, then reaches the B port of the lifting electromagnetic reversing valve 5 through the pipeline, and then reaches the T port. The hydraulic oil is directly returned to the tank at this time. At this time, the variable amplitude oil cylinder rod is retracted, and the platform can be lowered.

[0021] The opening of the falling proportional valve 6 directly determines the return speed of the hydraulic oil in the large cavity of the variable amplitude oil cylinder. By using the platform gravity descent system with a gravity descent valve with a compensator, when the platform is lowered, the pressure difference before and after the proportional valve is ensured to be constant through the compensator, the platform lowering speed is the same under the same proportional valve core opening regardless of the platform load, and the problem of fast speed does not occur, and better speed adjustability, safety and comfort are achieved.

[0022] The existing off-road scissors-type aerial work platform platform gravity descent system mainly opens the electromagnetic valve on the variable amplitude oil cylinder by applying voltage to the electromagnetic valve, and then relies on gravity to achieve the lowering. The lowering speed is changed by changing the valve core opening of the proportional electromagnetic valve, but the platform gravity descent system has a significant difference in lowering speed under the same valve core opening when the platform has different loads, especially when the platform load is heavy, the lowering speed is fast, and the platform gravity descent system has certain safety hazards and poor speed adjustability and comfort.

[0023] By using the platform gravity descent system with a gravity descent valve with a compensator, when the platform is lowered, the pressure difference before and after the proportional electromagnetic valve is ensured to be constant through the compensator, the platform lowering speed is the same under the same proportional valve core opening regardless of the platform load, and the problem of fast speed does not occur, and better speed adjustability, safety and comfort are achieved.

Claims

1. An aerial work platform applying a gravity lowering speed compensation control system, characterized in that: The hydraulic system comprises a hydraulic oil tank (1), a gear pump (2), a system overflow valve (3), a lifting proportional valve (4), a lifting electromagnetic reversing valve (5), a falling proportional valve (6), a one-way valve (7), an amplitude cylinder (8), a falling electromagnetic reversing valve (9) and an overflow valve (10), the falling electromagnetic reversing valve (9) is a valve for controlling switching value, the falling proportional valve (6) is a valve for controlling analog value, the opening of the falling proportional valve (6) determines the oil return speed of the large cavity hydraulic oil of the amplitude cylinder (8), when the platform is descending, the pressure difference before and after the lifting proportional valve (4) and the falling proportional valve (6) is kept unchanged, and the valve core opening degree proportion is kept the same through a compensator; the proportional valve (4) and the lifting electromagnetic reversing valve (5) are powered at the same time, the lifting electromagnetic reversing valve (5) is reversed to the left side, the engine drives the gear pump (2) to rotate, the gear pump (2) sucks oil from the hydraulic oil tank (1) to provide hydraulic oil for the lifting action; the oil in the hydraulic oil tank (1) reaches the P end of the lifting electromagnetic reversing valve (5) through the lifting proportional valve (4), then reaches the A end of the lifting electromagnetic reversing valve (5), then reaches the large cavity of the amplitude cylinder (8) through the hydraulic pipeline and the one-way valve (7) and finally reaches the oil cylinder large cavity through the falling electromagnetic reversing valve (9).

2. The aerial work platform using the gravity lowering speed compensation control system according to claim 1, characterized in that: The oil in the amplitude cylinder (8) makes the oil cylinder rod extend and retract, and performs the platform lifting and falling action.

3. The aerial work platform using the gravity lowering speed compensation control system according to claim 1, characterized in that: The lifting proportional valve (4) is not powered, the lifting electromagnetic reversing valve (5), the falling proportional valve (6) and the falling electromagnetic reversing valve (9) are powered at the same time, the falling electromagnetic reversing valve (9) is fully opened, the hydraulic oil in the large cavity of the amplitude cylinder (8) reaches the falling proportional valve (6) through the falling electromagnetic reversing valve (9), then reaches the T end from the B end of the lifting electromagnetic reversing valve (5) through the pipeline and returns to the oil tank.

4. The aerial work platform using the gravity lowering speed compensation control system according to claim 1, characterized in that: The opening degree of the valve port of the falling proportional valve (6) is determined by the size of the handle angle.

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