Forklift hydraulic system with dynamic throttling speed governing circuit

Abstract

The invention discloses a forklift hydraulic system with a dynamic throttling speed governing circuit. The forklift hydraulic system comprises a multi-way reversing valve, an oil inlet P, an oil returning opening T and a compensation valve. An oil inlet C of the multi-way reversing valve and an oil inlet of the compensation valve communicate with the oil inlet P. An oil returning opening D of the multi-way reversing valve and an oil outlet of the compensation valve communicate with the oil returning opening T. When the multi-way reversing valve reaches a first work position in a reversing mode, a first work oil opening F of the multi-way reversing valve communicates with the oil inlet C and an oil outlet E of the multi-way reversing valve, and a second work oil opening G of the multi-way reversing valve communicates with the oil returning opening D of the multi-way reversing valve. When the multi-way reversing valve reaches a second work position in a reversing mode, the first work oil opening F of the multi-way reversing valve communicates with the oil returning opening D of the multi-way reversing valve, and the second work oil opening G of the multi-way reversing valve communicates with the oil inlet C and the oil outlet E of the multi-way reversing valve; the oil outlet E of the multi-way reversing valve communicates with a control oil opening where the end, with a spring, of the compensation valve is located, and a control oil opening where the end, without the spring, of the compensation valve is located communicates with the oil inlet P. According to the forklift hydraulic system, the effect that a forklift has a constant portal frame tilting angle and accessory movement speed during the empty load or load carrying can be ensured, and the work efficiency is ensured.

Description

technical field [0001] The invention relates to a forklift hydraulic system, in particular to a forklift hydraulic system with a dynamic throttling speed regulation circuit. Background technique [0002] At present, most of the forklifts below 25T in China use a quantitative pump hydraulic system, and the flow of the system is generally determined according to the flow requirements required for the mast to rise. When the mast is tilted or the attachment is moved, due to the requirement of the working cylinder's movement speed, the required flow is only 30% to 50% of the maximum flow, and the excess flow is overflowed back to the hydraulic oil tank through the overflow valve at high pressure, and the This produces a large energy loss, causing the system to heat up and affecting the normal operation of the system. [0003] The invention patent application with the Chinese patent application number CN201410224032.X proposes a forklift hydraulic system with a throttling and spe...

AI Technical Summary

Problems solved by technology

However, this solution also has the following disadvantages: under the premise of a certain pump speed, the solution will lean forward faster when it is loaded than when it is unloaded, and when it is loaded, it will tilt backward faster than when it is no-load. The backward tilting speed is slow, which will affect the normal working efficiency of the forklift

Therefore, this solution still cannot realize dynamic throttling and speed regulation, and fails to realize the characteristic that the speed of the forklift mast or attachment is constant regardless of whether it is loaded or not.

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