CN201343061Y

CN201343061Y - Integrated internal combustion forklift dynamic signal load sensing hydraulic steering system

Info

Publication number: CN201343061Y
Application number: CNU2008201703555U
Authority: CN
Inventors: 徐征宇; 杨旭; 王建超
Original assignee: Zhejiang Hangcha Imp&expco Ltd
Current assignee: Hangcha Group Co Ltd
Priority date: 2008-12-18
Filing date: 2008-12-18
Publication date: 2009-11-11
Anticipated expiration: 2018-12-18

Abstract

The utility model relates to an integrated internal combustion forklift dynamic signal load sensing hydraulic steering system. The utility model aims to provide the hydraulic steering system with the advantages of simple structure, high sensitivity, high response speed and good stability. The technical scheme for solving the problem is as follows: an outlet of a quantitative gear pump is connected to an oil inlet of a priority valve, a first oil outlet of the priority valve is connected to a steering device which is communicated with an oil cylinder through a PF oil way, a second oil outlet of the priority valve is connected to the steering device through an LS signal oil way, a third oil outlet of the priority valve is communicated with an oil return pipeline and a high-flow multi-way directional valve at the same time, an oil outlet of the high-flow multi-way directional valve is connected to an oil return filter through the oil return pipeline, a steering overflow valve is arranged at the second oil outlet of the priority valve, the other end of the steering overflow valve is communicated with the oil return filter through the oil return pipeline, and an oil return port of the steering device is connected to the oil return filter. The integrated internal combustion forklift dynamic signal load sensing hydraulic steering system is mainly used for 1-3.5t internal combustion counter balanced forklift trucks.

Description

Integrated diesel fork lift truck dynamic state signal load sensing hydraulic steering system

Technical field

The utility model relates to a kind of diesel fork lift truck hydrostatic steering system, and particularly a kind of integrated diesel fork lift truck dynamic state signal load sensing hydraulic steering system is mainly used in the 1-3.5t engine balance forklift.

Background technology

As shown in Figure 1, common diesel fork lift truck hydrostatic steering system by oil suction oil filter 1 ', quantitative gear pump 2 ', system's by pass valve 3 ', flow divider valve 4 ', turn to by pass valve 5 ', deflector 6 ', turn to oil cylinder 7 ', multiple directional control valve 8 ', lift oil tank 9 ' and governor valve 10 ', dump ram 11 ', oil return oil filter 12 ' etc. form, and sees for details shown in Figure 1.No matter whether deflector works, the flow that flow divider valve all guarantees 10-12L/min through the PF oil circuit by deflector for turning to oil cylinder to use, or flow back to fuel tank by deflector, like this, when deflector is not worked, waste the flow about 10L/min, not only increased system's heating, and reduced the work efficiency of complete machine; In addition, owing to be the stationary singnal system, system sensitivity is lower, speed of response is slower, and stability neither be fine.

Summary of the invention

The technical problems to be solved in the utility model is: at the problem of above-mentioned existence provide a kind of simple in structure, highly sensitive, speed of response fast, the integrated diesel fork lift truck dynamic state signal load sensing hydraulic steering system of good stability, when deflector is not worked, can save the flow of hydraulic oil, to reach energy-conservation, minimizing system heating, the purpose of increasing work efficiency simultaneously.

The technical scheme that the utility model adopted is: integrated diesel fork lift truck dynamic state signal load sensing hydraulic steering system, has the oil suction oil filter, its mouth is connected to quantitative gear pump, this quantitative gear pump outlet is connected with system's by pass valve, system's by pass valve other end is connected to the oil return oil filter by oil return line, it is characterized in that: described quantitative gear pump outlet is connected to the oil inlet of pressure-gradient control valve, an oil outlet of pressure-gradient control valve is connected to and the deflector that turns to oil cylinder to be communicated with by the PF oil circuit, second oil outlet of pressure-gradient control valve is connected to deflector by LS signal oil circuit, the 3rd oil outlet of pressure-gradient control valve is communicated with oil return line and big flow multiple directional control valve simultaneously, the return opening of big flow multiple directional control valve is connected to the oil return oil filter by oil return line, second oil outlet place of described pressure-gradient control valve is provided with and turns to by pass valve, this turns to the by pass valve other end to be communicated to oily oil filter by oil return line, and the return opening of deflector is connected to the oil return oil filter.

Described big flow multiple directional control valve is the serial multiplex change-over valve that the inclination change-over valve and the change-over valve that hoists are formed, and the actuator port of its medium dip change-over valve is communicated to dump ram, and the actuator port of the change-over valve that hoists is connected to hoist cylinder by governor valve.

The body cavity B that every way reversing valve body is used to install valve rod in the described big flow multiple directional control valve expands as φ 23mm by φ 22mm, and valve rod hole A expands as φ 16mm by φ 15mm.

Described LS signal oil circuit is provided with flow regulating valve.

Described PF oil circuit is provided with check valve.

The beneficial effects of the utility model are: 1) the employing pressure-gradient control valve is controlled to the work loop and is turned to the loop fuel feeding, article two, the loop is independent of each other, during deflector work, the preferential flow that guarantees 10-12L/min through the PF oil circuit by deflector for turning to the oil cylinder use, when deflector is not worked, has only seldom flow (1L/min) through LS signal oil circuit, flow back to fuel tank by deflector and oil return oil filter, compare with common diesel fork lift truck hydrostatic steering system of the prior art, when deflector is not worked, flow is saved about 10L/min, thereby realized energy saving of system, reduced system's heating, when engine idle and rated speed of rotation, the door frame lifting velocity can improve respectively about 100% and 20%, has improved work efficiency; 2) adopt the Dynamic Signal system to replace stationary singnal of the prior art system, when deflector is not worked, remain the flow about 1L/min in the LS signal oil circuit, the sensitivity and the speed of response of system have been improved greatly, valve body is difficult for clamping stagnation, it is more reliable to work, and has improved the startability of system under the cold conditions simultaneously; 3) big flow multiple directional control valve is by strengthening multiple directional control valve oil duct latus rectum, optimizing oil channel structure, the more common multiple directional control valve of rated flow increases by 20%, reach 80L/min, significantly reduced the loss of pressure of multiple directional control valve, be used with the load sensing hydrostatic steering system, under quantitative gear pump discharge capacity unmodified prerequisite, overcome the phenomenon that increases the loss of pressure increase that causes owing to hydraulic fluid flow rate effectively by multiple directional control valve, make system performance more perfect.

Description of drawings

Fig. 1 is the structure diagram of the utility model background technology.

Fig. 2 is a structure diagram of the present utility model.

Fig. 3 is the constructional drawing of single commutation valve body in the big flow multiple directional control valve of the utility model.

The specific embodiment

As shown in Figure 2, present embodiment has oil suction oil filter 1, its mouth is connected to quantitative gear pump 2, this quantitative gear pump outlet is connected with system's by pass valve 3, system's by pass valve 3 other ends are connected to oil return oil filter 12 by oil return line, described quantitative gear pump 2 outlets are connected to the oil inlet of pressure-gradient control valve 4, an oil outlet of pressure-gradient control valve 4 is connected to and the deflector 6 that turns to oil cylinder 7 to be communicated with by PF oil circuit 14, second oil outlet of pressure-gradient control valve 4 is connected to deflector 6 by LS signal oil circuit 13, the 3rd oil outlet of pressure-gradient control valve 4 is communicated with oil return line and big flow multiple directional control valve 8 simultaneously, the return opening of big flow multiple directional control valve 8 is connected to oil return oil filter 12 by oil return line, second oil outlet place of described pressure-gradient control valve 4 is provided with and turns to by pass valve 5, this turns to the by pass valve other end to be communicated to oily oil filter 12 by oil return line, and the return opening of deflector 6 is connected to oil return oil filter 12.

Described big flow multiple directional control valve 8 is the serial multiplex change-over valve of the inclination change-over valve and the change-over valve composition that hoists, the 3rd oil outlet of pressure-gradient control valve 4 is communicated to the inclination change-over valve and the oil inlet of the change-over valve that hoists by two check valves respectively, the actuator port of its medium dip change-over valve is communicated to dump ram 11, the actuator port of change-over valve of hoisting is connected to hoist cylinder 9 by governor valve 10, and the return opening of the inclination change-over valve and the change-over valve that hoists all is connected to oil return oil filter 12 by oil return line.

As shown in Figure 3, in order to strengthen multiple directional control valve oil duct latus rectum, to optimize oil channel structure, this example is expanded as φ 23mm with the body cavity B that every way reversing valve body is used to install valve rod by original φ 22mm, valve rod hole A expands as φ 16mm by original φ 15mm, the more common multiple directional control valve of rated flow after the optimization increases by 20%, reach 80L/min, significantly reduced the loss of pressure of multiple directional control valve.

Described LS signal oil circuit 13 is provided with flow regulating valve.

Described PF oil circuit 14 is provided with check valve, can only flow to deflector 6 from pressure-gradient control valve 4 with assurance hydraulic oil, and can not reverse reflux.

In this example, oil suction oil filter 1 and oil return oil filter 12 are used to guarantee the cleanliness level of system's hydraulic oil; System's by pass valve 3, turn to by pass valve 5 control system oil circuit and turn to the pressure of oil circuit respectively, when oil circuit pressure surpassed limit value, by pass valve was opened unloading, guaranteed the fork truck trouble free service; 10 flows by modulated pressure oil of governor valve when forklift door frame is descended, are controlled at descending speed in the safe range, and when door frame rose, governor valve was then inoperative.

The principle of work of present embodiment is: hydraulic oil is behind oil suction oil filter 1 impurity screening, in the quantitative gear pump 2 suction pressure-gradient control valves 4 that drive by driving engine 15, when deflector 6 is not worked, pressure-gradient control valve 4 control PF oil circuits 14 are fuel feeding not, simultaneously seldom the hydraulic oil of flow (1L/min) through LS signal oil circuit 13, flow back to fuel tank by deflector 6 and oil return oil filter 12, remaining hydraulic oil is then sent into the inclination change-over valve by pressure-gradient control valve 4 and is hoisted in the change-over valve, use for fork truck dump ram 11 and lift oil tank 9, and the tilting action that is respectively forklift door frame by the inclination change-over valve and the change-over valve that hoists provides power with the action that hoists, if this moment, forklift door frame was failure to actuate, then this part hydraulic oil passes through oil return line, oil return oil filter 12 flows back to fuel tank; When deflector 6 work, pressure-gradient control valve 4 preferential assurances turn to loop works, the promptly preferential flow that guarantees 10-12L/min through the PF oil circuit by deflector 6 for turning to the oil cylinder use, realize turning to of fork truck by deflector 6 controls, remaining hydraulic oil then uses for fork truck dump ram 11 and lift oil tank 9 by the inclination change-over valve and the change-over valve that hoists, if this moment, forklift door frame was failure to actuate, then this part hydraulic oil flows back to fuel tank by oil return line, oil return oil filter 12.

In order to reduce system pipeline quantity, significantly reduce pressure loss in piping, pressure-gradient control valve 4 and big flow multiple directional control valve 8 can be integrated.

Claims

1, a kind of integrated diesel fork lift truck dynamic state signal load sensing hydraulic steering system, has oil suction oil filter (1), its mouth is connected to quantitative gear pump (2), this quantitative gear pump outlet is connected with system's by pass valve (3), system's by pass valve (3) other end is connected to oil return oil filter (12) by oil return line, it is characterized in that: described quantitative gear pump (2) outlet is connected to the oil inlet of pressure-gradient control valve (4), an oil outlet of pressure-gradient control valve (4) is connected to and the deflector (6) that turns to oil cylinder (7) to be communicated with by PF oil circuit (14), second oil outlet of pressure-gradient control valve (4) is connected to deflector (6) by LS signal oil circuit (13), the 3rd oil outlet of pressure-gradient control valve (4) is communicated with oil return line and big flow multiple directional control valve (8) simultaneously, the return opening of big flow multiple directional control valve (8) is connected to oil return oil filter (12) by oil return line, second oil outlet place of described pressure-gradient control valve (4) is provided with and turns to by pass valve (5), this turns to the by pass valve other end to be communicated to oily oil filter (12) by oil return line, and the return opening of deflector (6) is connected to oil return oil filter (12).

2, integrated diesel fork lift truck dynamic state signal load sensing hydraulic steering system according to claim 1, it is characterized in that: described big flow multiple directional control valve (8) is the serial multiplex change-over valve of the inclination change-over valve and the change-over valve composition that hoists, the actuator port of its medium dip change-over valve is communicated to dump ram (11), and the actuator port of the change-over valve that hoists is connected to hoist cylinder (9) by governor valve (10).

3, integrated diesel fork lift truck dynamic state signal load sensing hydraulic steering system according to claim 1 and 2, it is characterized in that: the body cavity B that every way reversing valve body is used to install valve rod in the described big flow multiple directional control valve (8) expands as Φ 23mm by Φ 22mm, and valve rod hole A expands as Φ 16mm by Φ 15mm.

4, integrated diesel fork lift truck dynamic state signal load sensing hydraulic steering system according to claim 1 and 2 is characterized in that: described LS signal oil circuit (13) is provided with flow regulating valve.

5, integrated diesel fork lift truck dynamic state signal load sensing hydraulic steering system according to claim 1 and 2 is characterized in that: described PF oil circuit (14) is provided with check valve.

6, integrated diesel fork lift truck dynamic state signal load sensing hydraulic steering system according to claim 3 is characterized in that: described PF oil circuit (14) is provided with check valve.