JPS6082472A - Braking force controller for vehicle - Google Patents

Abstract

PURPOSE:To control braking force in an air suspension car according to its loading capacity, by linking up an on-off controlling plunger part installed in a load sensing valve with an air pressure feed passage of an air bellows for a suspension. CONSTITUTION:A port 10 is installed in a part of a plunger 9 of a load sensing valve 4. Then, an air pressure feed passage to an air bellows 1 of an air suspension is linked up with the port 10 through an air pressure pipe 8. With this constitution, the plunger 9 is set in motion with hydraulic pressure to the air bellows 1, controlling the load sensing valve 4 according to its loading capacity.

Description

[Detailed description of the invention] The present invention relates to a braking force control device for a vehicle.

The weight difference between empty and loaded trucks and buses varies greatly depending on the number of passengers, and there is a particularly significant difference in the load applied to the rear wheels. Normally, the appropriate braking force is designed according to the weight of the loaded vehicle, so when the vehicle is empty, excessive braking is applied, making the rear wheels in particular more likely to lock up. In order to prevent this, it is known that a load sensing pulp is installed which controls the air pressure or hydraulic pressure Z to operate the rear wheel braking device according to the weight of the loaded vehicle to provide an appropriate braking force.

This load sensing pulp controls the amount of displacement of the rear axle relative to the frame using a lever.

However, some vehicle suspensions use air bellows, but in this case, the distance between the rear axle and the frame is constant regardless of the load, so it may be difficult to control braking mold using conventional means. be.

Nowadays, many vehicles equipped with air suspensions are being produced to improve ride comfort, and there is a demand for air suspension vehicles to be able to control the braking force in accordance with the weight of the vehicle loaded.

In response to the above-mentioned requirements, the present invention makes it possible to control the braking force using a load sensing valve without changing the design of air suspension vehicles.

Embodiments of the present invention will be described below with reference to the drawings.

In Fig. 1, 1 is an air bellows that suspends the vehicle body, and is connected to an air tank via a leveling valve 2 and a surge tank 3, and a leveling pulp 2 opens and closes depending on the loading type ff1K, and the required air pressure is applied to the air bellows. 1. The present invention provides a load sensing pulp 4 in a vehicle whose body is suspended by such an air bellows 1. This load sensing pulp 4 is controlled according to the signal pressure from the brake valve 5 according to the weight of the loaded vehicle as in the past, and the signal pressure is sent to the relay pulp 6, and the air pressure for braking is sent from the air tank to the brake chamber 7. The braking force is controlled to an appropriate level according to the weight of the loaded vehicle, but like a conventional load sensing valve, it uses a lever that is activated by the amount of displacement of the rear axle relative to the frame, and a lever that is connected to this lever.
A plunger for opening/closing control installed inside the load sensing valve? The entire operating link machine J6'tjY (removed, and the boat 1 is attached to the plunger 90 part as shown in Figure 2)
0'=a? Provided, if necessary, between the outer periphery of the granger 9 and the valve casing? The structure includes a seal ring 2 for sealing. The bow 10 and the air pressure supply path between the surge tank 3 and the air bellows 1 in the air bellows 1 are connected by an air pressure conduit 8. In FIG. 3, a piston 11 is formed in order to increase the pressure receiving area of the plunger 9, and a spring 12 is attached to the piston 11.
This shows an example of a design change in which the characteristics of the air pressure inside the air bellows and the input to the plunger can be changed depending on the situation.

According to the present invention, the air bellows 1
The pressure fluctuations in the air pressure inside are applied as a signal pressure to the load sensing pulp 4 through the air pressure conduit 8, and the rear wheel braking force is appropriately controlled according to the loaded state of the vehicle. Therefore, it is possible to control the braking force when an air suspension vehicle is empty or loaded, which was previously impossible, and the mechanism can be easily obtained without major design changes to the conventional piping configuration. In addition, it has the advantage of being able to be put to practical use at a low cost.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of the apparatus of the present invention, FIG. 2 is a sectional view of a load sensing pulp, and FIG. 3 is a sectional view of a main part showing an example of a design change of the load sensing pulp. 1...-Air bellows, 4-a. Load sensing pulp, 8...-Air pressure conduit, 9... Plunger, 10-
··boat. Figure 2 i-4 Figure 3

Claims (1)

[Claims] In a vehicle in which the vehicle body is suspended by air bellows, a load sensing valve is provided for controlling the fluid pressure that operates the rear wheel braking device, and a plunger portion for opening/closing control provided in the load sensing valve and the air bellows are provided. A braking force control device for a vehicle, characterized in that the air pressure supply path is connected to the air pressure supply path through four air pressure pipes.