KR20020045464A - Levelling valve having check valve - Google Patents

Abstract

PURPOSE: A leveling valve having a check valve is provided to prevent movement of a cab in stopping tilting by checking pressure with mounting the check valve in an air outlet of the leveling valve and by regulating pressure with a check spring. CONSTITUTION: An air suspension is composed of a cab, a cab tilt cylinder, an air spring, a leveling valve keeping the height of the vehicle, a floating bar, a hydraulic latch, a shock absorber, a cab bridge and a mudguard pipe. Impact from a chassis is absorbed with installing an air spring between the chassis and the cab, and driving experience is improved with the cab suspension of a large truck. A check valve is installed in the leveling valve to keep pneumatic pressure. The leveling valve has an upper case(11), a lever, a disk(13), a shaft(14), a pivot(15), a coil spring(16) and a lower case(17). Pressure of air is kept with the check valve, and pressure is regulated with tension of a check spring. Movement of the cab is prevented with mounting the check valve in the leveling valve in stopping tilting of the cab.

Description

Leveling valve with built-in check valve {LEVELLING VALVE HAVING CHECK VALVE}

The present invention relates to a leveling valve with a built-in check valve, and more particularly, a leveling valve with a built-in check valve that can solve the flow problem when the cap tilts by integrating the functions of the magnetic valve and the leveling valve in a cap air suspension application vehicle.

Due to the repetition of supplying and discharging air to the air spring due to the lever flow of the leveling valve for leveling valve according to the position change of the center of gravity of the cab, the intermediate point of cab tilting in a cab air suspension-mounted vehicle of a large truck The flow occurred back and forth to the cap at the tilting stop.

Conventionally, a magnetic valve, a valve that controls air to allow constant speed cap tilting by blocking the flow of air when tilting the cap, has been added.However, due to the lever flow of the leveling valve according to the center of gravity of the cap, the air line There was a problem accompanied by a change in the internal air pressure.

An object of the present invention is to provide a leveling valve having an air pressure maintaining function on its own instead of a magnetic valve installed to prevent a conventional lever flow in order to solve the flow problem in the cap tilting.

According to a feature of the present invention for solving the above problems, in the air suspension device having a leveling valve for maintaining a constant height of the cap by the suction and discharge of air to absorb the shock transmitted from the chassis to the cap, the The leveling valve has a check valve built in, and the check valve is built in an air outlet side of the leveling valve. The check valve performs a check function when the required pressure is lower than the required pressure, and the required pressure is controlled by a check spring.

1 is a perspective view showing the structure of a cab air suspension of a freight vehicle;

2 is a circuit diagram of a cab air suspension system of a conventional freight vehicle in part A of FIG.

3 is a circuit diagram of a cab air suspension system of a freight vehicle according to the invention in part A of FIG.

4 is a schematic perspective view of a leveling valve according to the present invention;

5A-5C are schematic diagrams illustrating air pressure operation of a leveling valve equipped with a check valve according to the present invention.

<Explanation of symbols for main parts of drawing>

1: Cap of cargo vehicle 2, 24, 32: Leveling valve

3: floating bar 4: hydraulic latch

5: mudguard pipe 6: cap bridge

7: air spring 8: shock absorber

9: frame 10: cap tilt cylinder

11: upper case 12: lever

13: disk 14: shaft

15 pivot 16: coil spring

17: lower case 21: air tank

22: magnetic valve 23: air supply valve

25: check valve 26, 27: surge tank

28, 29: air spring 30, 31: cap mounting

The configuration of the present invention will be described below with reference to the accompanying drawings.

1 is a perspective view showing an air suspension structure. As shown in Fig. 1, the air suspension is used with a cab (1), a cab tilt cylinder (10), an air spring (7) of a freight vehicle, generally one at the front suspension and two at the rear suspension. Leveling valve (2), floating bar (3), hydraulic latch (4), shock absorber (8), cap bridge (6), mudguard pipe (5), and the like. In a large truck, the cab suspension system is applied for the purpose of improving the riding comfort. The cab suspension system includes a coil type suspension and an air type air suspension with an air spring, and the present invention provides a shock transmitted from the chassis while driving. Air suspension is absorbed by air spring installed between chassis and cab to improve the comfort of the safety while driving.

2 is a circuit diagram of a cab air suspension system of a conventional freight vehicle in part A of FIG. As shown in FIG. 2, the cab air suspension system includes an air tank 21, a magnetic valve 22 that is a valve that controls air so as to allow constant speed cap tilting by blocking the flow of air during cab tilting, and an air suspension system. Air supply valve 23 which prevents air backflow inside and protects the brake system, and leveling valves 24 and 32 which are valves which maintain a constant cap height by intake and discharge of air when the cap height is changed by the vertical movement of the cap while driving. ), A surge tank (26, 27) as an air spring constant correction aid, and an air spring (28, 29) that cushions and attenuates the cap by using air. ). The working pressure of the air supply valve is preferably 3.2 to 3.5 kgf / cm ² .

3 is a circuit diagram of a cab air suspension system of a freight vehicle according to the invention in part A of FIG. As shown in FIG. 3, the magnetic valve 22 installed to prevent the lever flow was removed, and a check valve 25 which functions as an air pressure holding function was added to the leveling valve 24 instead.

4 is a schematic perspective view of a leveling valve according to the invention. As shown in FIG. 4, the leveling valve includes an upper case 11, a lever 2 for regulating air inflow, a disk 13, a shaft 14, a pivot 15, a coil spring 16, and a lower portion. And a case 17.

Figure 5a shows a leveling valve incorporating a check valve in accordance with the present invention, the check valve performs an air pressure maintenance function using a check pivot and a check spring and the required pressure adjustment is performed by turning the check spring tension. Fig. 5B shows the operation of the check valve before the air pressure operation, and Fig. 5C shows the operation of the check valve during the air pressure operation.

The present invention is not limited to the above embodiments and can be implemented in various modifications.

As described above, according to the present invention, a check valve for controlling air may be built in the leveling valve to perform a check function at a required pressure or less. Therefore, it is possible to solve the problem that the cap flows back and forth when the cap tilting stop (40 °) tilting stops in a vehicle equipped with a cab air suspension of a large truck.

Claims (2)

An air suspension device having a leveling valve that maintains a constant height of a cap by suction and discharge of air to absorb a shock transmitted from the chassis to the cap. And said leveling valve has a built-in check valve. The method of claim 1, The check valve is provided on the air outlet side of the leveling valve, characterized in that the air suspension device.