JPH06239253A - Idling-up device for industrial vehicle - Google Patents

Abstract

PURPOSE:To prevent the occurrence of an engine stop by increasing engine speed up to the predetermined number of revolutions through the operation of either a work machine system or a power steering system. CONSTITUTION:A hydraulic valve 6 capable of giving two different stroke values according to two different hydraulic pressure values, is directly fitted to a seat 22 on the existing piping 21 of a hydraulic circuit section. Furthermore, the piston section of an operation rod is of labyrinth groove seal type, and the piston is single acting type. In addition, a drain passage 24 is formed in a spring chamber, and a necessary amount for pressing a throttle valve 9 is made adjustable through a throttle side lever ratio variable link 11 for the stroke of the valve 6 via a cable connection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an idle up device for an industrial vehicle, which controls an engine speed according to a load.

[0002]

2. Description of the Related Art In a conventional idle-up device, a throttle valve is opened and closed by a diagram-type actuator that operates by negative pressure in an intake manifold of an engine. On the other hand, the present applicant has previously proposed Japanese Patent Application No. 3-213109, in which the load hydraulic pressure is introduced into the hydraulic valve and the throttle valve is actuated via the actuating rod by the operation of the spools having different movement strokes. It was designed to control the opening and closing.

[0003]

With the above-mentioned improvement, the engine speed can be controlled according to the load, and a device which is responsive and has less noise can be provided. However, the mounting position of the hydraulic valve is in the throttle portion. Therefore, a dedicated bracket for mounting is required, and if oil leaks, the exhaust will be oiled and there is a risk of fire.

Further, the hydraulic valve piping circuit requires two high-pressure circuit pipings for a working machine system and a power steering system, and since the return spring side is open to the atmosphere, it causes oil leakage to the outside due to deterioration of the seal. Becomes

Regarding the stroke of the hydraulic valve,
The two-stage piston changes the two different pressures in the working machine system and the power steering system into two different strokes. Therefore, the required thrust amount of the throttle valve must be adjusted by the spacer inside the valve depending on the engine difference. It had a problem of solution.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a hydraulic valve is directly mounted by providing a seat on an existing pipe of a hydraulic circuit, and a piston portion of an operating rod is provided with a labyrinth groove seal. A single piston is used, a drain circuit is installed on the spring chamber side, and the required amount to press the throttle valve can be adjusted with a lever ratio variable link on the throttle side, and a cable is connected between the throttle levers of the hydraulic valves. .

[0007]

With the above structure, by changing the mounting position of the hydraulic valve, there is no fear of fire due to oil leakage, the dedicated bracket for the throttle part is not required, and the mounting on the existing pipe and the spring chamber side By providing a drain circuit on the back side, piping for the low pressure drain 1 circuit of the return spring is enough and there is no oil leakage to the outside. In addition, the hydraulic valve is a single piston, and the structure is simple because it has a built-in spring that balances the stroke in proportion to the pressure.Since the labyrinth groove seal system is adopted for the piston part of the operating rod, no seal is required and repeated operation durability In addition to improving the speed, it is easy to adjust the required amount of pushing the throttle, so it is highly versatile. In addition, since the hydraulic valve and the throttle lever are connected by a cable, it has excellent flexibility that it can be easily mounted on different engines.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an idle-up device for an industrial vehicle according to an embodiment of the present invention, FIG. 2 is a sectional view of a hydraulic valve, and FIG. 3 is an example showing operating characteristics of an operating rod. As shown in FIGS. 6 and 7 showing the hydraulic circuit of the present invention, a seat 22 is provided on the discharge side hydraulic pipe 21 of the hydraulic pump 2 driven by the engine 1, and the hydraulic valve 6 is attached. In the case of the two pumps in FIG. 7, the hydraulic valve 6 is attached via the check valve 23 in order to prevent the hydraulic interference between the working machine system and the power steering system.

As shown in FIG. 2, the hydraulic valve 6 has an operating rod 6j and a piston portion 6b which are integrally formed.
It has a single piston configuration. Therefore, in order to obtain a stroke proportional to the hydraulic pressure, the structure is simple with a balance system incorporating the spring 7, and the drain circuit piping 24 is provided on the spring chamber side to prevent oil leakage to the outside. In addition to the fact that there is no oil leakage to the outside, there is no risk of fire due to the hydraulic pipe 21 being mounted at the mounting position and being separated from the engine. Further, since the piston portion 6b adopts the labyrinth groove seal system, no seal is required and the repeated operation durability is improved.

The stroke S of the operating lot 6j can be easily changed by replacing the spacer 6i. An example of the characteristic of the operating rod 6j is shown in FIG. 3, but it can be easily changed by replacing the spring 7 of the hydraulic valve 6 and the spacer 6i.

Using the tap 6k at the tip of the operating rod 6j of the hydraulic valve 6, the stroke S of the operating rod 6j is transmitted to the lever ratio variable type link 11 via the cable 12, and the link 11 pushes the push rod 13, The throttle lever 8 is turned so as to change the pushing amount of the throttle valve 9.

The variable lever ratio type link 11 moves the position of the lever fulcrum 26 with respect to the push rod 13 by means of the set screw 25, whereby the hydraulic valve 6 is moved.
After the stroke S is transmitted to the push rod 13 via the cable 12, it can be adjusted to the stroke S, and by changing the rotation angle of the throttle lever 8, the pushing amount of the throttle valve 9 can be adjusted. The push rod 13 is combined with the return spring 16, the loosening prevention spring 17, and the adjusting bolt 19, and is attached to the holder 14 together with the variable lever ratio type link 11.
The existing vacuum type diaphragm bracket 15 is used as it is and fixed.

FIG. 4 is a view showing another example of connection between the operating rod 6j and the cable 12. Fig. 5 shows the position of the lever fulcrum of the variable lever ratio type link using the set screw 25.
The adjustment part to move is shown.

[0014]

As described in detail above, according to the present invention, even if the working machine system and the power steering system are operated simultaneously or independently, the engine speed can be set to a preset value without lowering the engine speed. , The engine will not stop due to load fluctuations, and the engine speed will not rise unnecessarily and will not cause noise. In addition, it has a simple structure and can be manufactured at low cost, and because it can be easily adjusted, it can be easily mounted on engines with different specifications, and has excellent versatility.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an idle-up device for an industrial vehicle according to an embodiment of the present invention.

FIG. 2 is a sectional view of a hydraulic valve.

FIG. 3 is an example showing operating characteristics of an operating rod.

FIG. 4 is another example showing the connection of the working rod and the cable.

FIG. 5 is a front view showing an adjusting unit of the lever ratio variable link.

FIG. 6 is a hydraulic circuit diagram (at the time of one pump) of the present invention.

FIG. 7 is a hydraulic circuit diagram (at the time of two pumps) of the present invention.

[Explanation of symbols]

 1 Engine 2 Hydraulic Pump 2'Hydraulic Pump 3 Flow Divider 6 Hydraulic Valve 6b Piston Part 6j Actuating Rod 7 Spring 8 Throttle Lever 9 Throttle Valve 11 Link 12 Cable 13 Push Rod 21 Piping 21 'Piping 22 Seat 24 Drain Piping

Claims (1)

[Claims] 1. An industrial vehicle in which the discharge pressure of a hydraulic pump 2 driven by an engine 1 is diverted by a flow divider 3 to be supplied to a working machine system and a power steering system, or a working machine driven by an engine. System hydraulic pump and a power steering system hydraulic pump, in an industrial vehicle, two different hydraulic pressures are introduced, and the hydraulic valve 6 that changes two different moving strokes in proportion to the different generated hydraulic pressures is used. Existing piping 2
1 is provided with a seat 22 and is directly mounted, and the hydraulic valve 6 is a balance system of a single piston in which the piston portion 6b of the operating rod 6j is a labyrinth groove seal and a spring 7, and a drain circuit pipe 24 is provided on the spring chamber side. Is provided, and the stalk obtained by the hydraulic valve 6 is connected to the push rod 13 via a lever ratio variable link 11 which is connected by a cable 12 between the hydraulic valve 6 and the throttle lever 8.
Thus, the idle-up device for an industrial vehicle is characterized in that it can be adjusted and set to an optimum pushing amount of the throttle valve 9.