CN-122010021-A - Dual pressure maintaining hydraulic system of AGV fork truck decline proportional valve

Abstract

The invention relates to the technical field of intelligent logistics, discloses a dual pressure maintaining hydraulic system of an AGV fork truck descending proportional valve, and aims to solve the problem that the existing single pressure maintaining structure is easy to cause potential safety hazard after pressure release failure, the hydraulic control is carried out by using the original one-way valve and the T-way electromagnetic valve, and meanwhile, the electromagnetic valve is additionally arranged on the P, T oil way respectively to control the on-off of the oil way. P, T oil ways respectively realize double pressure maintaining measures, and potential safety hazards are avoided.

Inventors

• XIANG WEIFENG
• CHEN JIALIANG
• WANG LEI
• WANG CHIRU

Assignees

• 安徽合力宇锋智能科技有限公司

Dates

Publication Date

20260512

Application Date

20251226

Claims (6)

1. 1. The utility model provides a dual pressurize hydraulic system of AGV fork truck decline proportional valve which characterized in that includes: the oil tank (1) is used for storing lubricating oil, and an oil pump motor (2) is arranged above the oil tank; The P-way electromagnetic valve (3) is a two-position two-way electromagnetic valve, an oil way is not communicated when the power is off, the P-way electromagnetic valve is connected with the oil pump motor (2), the output lubricating oil is conveyed to the T-way electromagnetic valve (5) through the one-way valve (4), and the T-way electromagnetic valve (5) is communicated with the oil cylinder (6); an overflow proportional electromagnetic valve (7) for realizing the communication between the T-path electromagnetic valve (5) and the oil tank (1); After the lifting is finished, the oil pump motor (2) and the P-way electromagnetic valve (3) are in a power-off state, a P oil way is not communicated, the P-way electromagnetic valve (3) and the one-way valve (4) cannot reversely circulate, hydraulic oil cannot flow back, and double pressure maintaining is achieved.
2. 2. The AGV forklift descending proportional valve double pressure maintaining hydraulic system according to claim 1, wherein a valve core (11) is arranged in the overflow proportional electromagnetic valve (7) in a sealing manner, and the valve core (11) is controlled according to an electromagnetic control assembly (8) fixed at one end of the overflow proportional electromagnetic valve (7); The inner side of the overflow proportional electromagnetic valve (7) and two ends of the valve core (11) are respectively provided with a buffer cavity (703) and a backflushing cavity (704), the outer side part of the overflow proportional electromagnetic valve (7) is connected with an input pipe (701) communicated with the T-path electromagnetic valve (5), and the outer side of the overflow proportional electromagnetic valve (7) is also provided with an output pipe (702) communicated with the backflushing cavity (704); a return spring (110) is fixedly connected between the valve core (11) and the inner side of the overflow proportional electromagnetic valve (7); when the pressure is actively released, the area between the input pipe (701) and the recoil cavity (704) is increased, so that the reflux speed of hydraulic oil is controlled; Impurities in the input pipe (701) can be accumulated in the buffer cavity (703), the pressure of the input hydraulic oil is excessive, the pressure is enough to overcome the elastic force of the return spring (110), the buffer cavity (703) is communicated with the output pipe (702) by the valve core (11), and the impurities in the buffer cavity (703) and the lubricating oil are discharged through the output pipe (702).
3. 3. The AGV forklift descending proportional valve double pressure maintaining hydraulic system according to claim 2 is characterized in that a filter cartridge (12) which is coaxially and fixedly connected through bolts is arranged at the end part of the valve core (11), and a filter hole is formed in the outer side part of the filter cartridge (12).
4. 4. The AGV forklift descending proportional valve double pressure maintaining hydraulic system according to claim 3, wherein the end part of the filter cylinder (12) is coaxially and fixedly connected with a rotating seat (13), a plurality of inclined grooves which are annularly arranged are formed in the outer side of the rotating seat (13), a detection pipe (9) is fixedly arranged at the outer side part of the overflow proportional electromagnetic valve (7), a detection piston (15) is movably sleeved on the detection pipe (9) in a sealing mode, a detection spring (151) is fixedly arranged at the bottom end of the detection piston (15) and the inner side of the detection pipe (9), and a limiting ejector rod (152) is fixedly arranged at the top end of the detection piston (15).
5. 5. The dual pressure maintaining hydraulic system of the AGV forklift descending proportional valve according to claim 4, wherein a bleeder tube (10) communicated with the output tube (702) is fixedly arranged at the bottom of the outer side of the detection tube (9).
6. 6. The dual pressure maintaining hydraulic system of the AGV forklift descending proportional valve according to claim 4, wherein an anti-blocking ring (14) is movably mounted at the end part of the valve core (11), and a buffer spring (140) is arranged between the anti-blocking ring (14) and the valve core (11).

Description

Dual pressure maintaining hydraulic system of AGV fork truck decline proportional valve Technical Field The invention relates to the technical field related to intelligent logistics, in particular to a dual pressure maintaining hydraulic system of an AGV forklift descending proportional valve. Background AGV fork truck plays an increasingly important role in the field of industrial automation by virtue of advanced automatic control technology and intelligent perception system as a highly intelligent industrial vehicle robot. Compared with a common AGV, the AGV forklift not only has basic point-to-point material carrying capacity, but also can accurately convey cargoes from one position to another according to a preset path, and can be deeply integrated and realize a logistics transportation task of seamless butt joint among a plurality of production links. However, there are some problems in hydraulic systems of the AGV (unmanned) forklifts currently on the market that need to be solved. Taking an AGV forklift descending proportional valve hydraulic system as an example, in a P oil way (namely an oil cylinder ascending oil way), the pressure relief is limited by mainly relying on a one-way valve in a valve group, namely, the hydraulic oil is prevented from flowing back. This single dwell design appears to be somewhat placket in the face of a complex work environment and long term use. Once the check valve fails or the sealing performance is reduced, the hydraulic oil is easy to flow back, and the normal lifting action of the oil cylinder is affected. In the T oil way (namely the oil cylinder descending oil way), the valve group realizes the on-off of the oil way and the adjustment of the flow rate (by changing the size of the valve port) by controlling the valve port of the proportional electromagnetic valve. However, in the actual use process, the proportional solenoid valve often has a valve blocking phenomenon due to various reasons. For example, the cleanliness of hydraulic oil is not a significant factor. Because the hydraulic system is in operation, the hydraulic oil may be contaminated by the outside, such as dust, metal chips, and other impurities mixed therein. These impurities flow to the proportional solenoid valve along with the hydraulic oil, so that the impurities are easy to clamp at the valve port or the valve core, the proportional solenoid valve cannot be normally opened or closed, and then the oil way is not tightly closed, so that the pressure relief problem is caused. At present, P, T oil ways are respectively provided with only one pressure maintaining measure, and the pressure relief probability is relatively high due to the relatively simple pressure maintaining design. Once pressure release occurs, various faults can occur in the AGV forklift, so that after-sales maintenance is frequent, the operation cost of enterprises is increased, and the service efficiency of the AGV forklift is seriously affected. More serious, when the oil way is not pressure-maintaining, the oil cylinder descends to drive the fork to descend so as to change the position of the fork. If the control system of the AGV forklift fails to accurately identify the change of the position of the fork in time, safety accidents are possibly caused in the subsequent carrying or operating process, damage is caused to personnel and cargoes, and great potential safety hazards are brought. Disclosure of Invention The invention provides a dual pressure maintaining hydraulic system of an AGV forklift descending proportional valve, which has the advantage of dual pressure maintaining and aims to effectively solve the problem that the existing single pressure maintaining structure in the background art is easy to cause potential safety hazards after pressure release faults occur. The technical scheme is that the AGV forklift descending proportional valve dual pressure maintaining hydraulic system comprises an oil tank, a P-way electromagnetic valve, an overflow proportional electromagnetic valve, an oil pump motor, a P-way electromagnetic valve, a hydraulic oil return valve and a dual pressure maintaining valve, wherein the oil tank is used for storing lubricating oil, the oil pump motor is arranged above the oil tank, the P-way electromagnetic valve is a two-position two-way electromagnetic valve, an oil way is not communicated when the power is off, the oil pump motor is connected with the oil pump motor, the output lubricating oil is conveyed to a T-way electromagnetic valve after passing through a one-way valve, the T-way electromagnetic valve is communicated with an oil cylinder, the overflow proportional electromagnetic valve is used for realizing the communication between the T-way electromagnetic valve and the oil tank, the oil pump motor and the P-way electromagnetic valve are in a power-off state after ascending is completed, the P-way electromagnetic valve and the one-way electromagnetic valve are not communicated rev