JPH06115423A - Brake system for multishaft trailer - Google Patents

Abstract

PURPOSE:To solve a problem of the shortage of braking force at time of cargo loading following the insertion of a proportional pressure reduction control valve to a brake system of wheels which reduce the load in the braking time. CONSTITUTION:As a proportional pressure reduction control valve 80R to be inserted, a proportional pressure reduction control valve provided with a converting means to make the proportional pressure reduction control ineffective or effective is used, and the proportional pressure reduction control is made ineffective according to the rise of the pressure led from an antiskid control valve device 61R at a specific pressure or higher.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake system having an anti-skid control function,
The present invention relates to a braking technique that can be effectively used for a multi-axle trailer having a plurality of axles in the front-rear direction of a vehicle body.

[0002]

[Prior art and its problems] As a brake system for a multi-axle trailer, at least a part of a sensor for monitoring the rotation state of wheels is shared, and a discrimination circuit and an anti-skid control valve device are used based on a signal from the sensor. It is conceivable to control the pressures of all brake actuators (followers) of a plurality of wheels in common. According to this idea, parts of the system or a part of the apparatus can be shared, so that the configuration of the system can be simplified. The general idea of sharing parts and the like is already known, for example, in Japanese Patent Laid-Open No. 60-185662.

However, in the case of a multi-axle trailer, the axle weight of a plurality of axles in the front-rear direction of the vehicle body fluctuates during braking. In consideration of this fluctuation of the axle load, the applicant provides the wheel for which the load during braking becomes lighter among a plurality of wheels when commonly controlling the pressures of all the followers for the wheels on different axles. A technique of interposing a proportional pressure reducing control valve between a driven device and an anti-skid control valve device has been previously proposed (Japanese Patent Application No. 3-352737). The pressure reduction rate of the proportional pressure reducing control valve is set so that the wheels are not locked when the vehicle is empty, considering that the wheels are more likely to be locked when the vehicle is empty than when the vehicle is loaded. for that reason,
In the above-mentioned proposed technique, the braking force tends to be insufficient when the vehicle is loaded, as compared with a trailer equipped with a system having no proportional pressure reducing control valve. It is the same whether in anti-skid control or normal braking.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problem of insufficient braking force at the time of loading the vehicle, which is caused by inserting a proportional pressure reducing control valve in the previously proposed brake system for a multi-axle trailer. To provide.

[0005]

In the present invention, basically, as the proportional pressure reducing control valve to be inserted, one which can be switched to invalidate or enable the proportional pressure reducing control is used. Among them, a particularly preferable proportional pressure reducing control valve has a function of automatically invalidating the proportional pressure reducing control when the pressure introduced from the anti-skid control valve device rises above a predetermined pressure. By using such a proportional pressure reducing control valve, the proportional pressure reducing control function can be invalidated when the vehicle is loaded, and an appropriate braking force can be obtained.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the basic construction of a brake system when the present invention is applied to a two-shaft semitrailer. The basic configuration itself is the same as that of the above-mentioned prior application, except for the proportional pressure reducing control valve used and the control method thereof. In FIG. 1, a portion 10 surrounded by a chain double-dashed line is a vehicle body of a semitrailer. This vehicle body is provided with three couplers 11S, 11E and 12 for connecting to the tractor side (not shown). The two couplers 11S and 11E are hose couplers, one coupler 11S for the service line 13, and the other coupler 11E for the emergency line 15. The remaining coupler 12 is an electrical coupler and is connected to the electronic control unit 20 via the cord 16. The service line 13 and the emergency line 15 are connected to the corresponding ports of the relay emergency valve 25. The relay emergency valve 25 first functions as a relay valve. When the signal pressure from the brake valve on the tractor side is applied to the valve 25 via the service line 13, the valve 25 supplies the air in the air reservoir 26 to the brake line 30 according to the signal pressure. Further, the relay emergency valve 25 functions to apply an emergency brake to the semi-trailer side when the coupler 11E is removed or the emergency line 15 is damaged.

The semi-trailer 10 includes a front shaft 41 and a rear shaft 4.
2 and 2 axles, and each axle has a pair of left and right wheels (or wheel groups) 41L, 41R; 42L, 42R. Then, for each wheel 41L, 41R; 42L, 42R,
Brake chambers 51L, 51R; 52 that are followers
L and 52R are provided. It goes without saying that each of these brake chambers 51L, 51R; 52L, 52R is supplied with brake pressure from the relay emergency valve 25 side via the brake line 30. The brake system belonging to the brake line 30 has two independent left and right.
It is a channel. The brake line 30 is a common line 30C extending from the relay emergency valve 25.
And two branch lines 30R and 30L branched from it
Consists of. On the respective branch lines 30R and 30L, there are the antiskid control valve devices 61R and 61L and the brake chambers 51L and 51R; 52L and 52R, respectively. Each anti-skid control valve device 61R, 61L,
A known solenoid valve device including a shutoff valve and a slack valve,
Based on a command from the electronic control unit 20 that constitutes the determination circuit, each brake chamber 51L, 51R; 52
The brake pressure of the branch lines 30R and 30L leading to L and 52R is controlled. In order to control the brake pressure in this way, it is necessary to monitor the rotation state of the left and right wheels. It uses a wheel speed sensor, but one for each left and right channel to simplify the system.
Two sensors 71R and 71L are provided. This embodiment is front-axis sensing, and the left and right wheels 41 on the front-axis 41 are
Sensors 71R and 71L are provided for R and 41L, respectively.

In the semi-trailer 10, the front shaft 41 and the rear shaft 42 have different axial loads or axial loads during braking, and the front shaft 41 is lighter than the rear shaft 42.
Therefore, the proportional pressure reducing control valves 80R and 80L are interposed between the brake chambers 51R and 51L for braking the wheels 41R and 41L on the front shaft 41 and the left and right anti-skid control valve devices 61R and 61L, respectively. ing. As these proportional pressure-reducing control valves 80R and 80L, those which can be switched so as to invalidate or enable the proportional pressure-reducing control here, in particular, the pressure introduced from the anti-skid control valve devices 61R and 61L is predetermined. A device that can automatically invalidate the proportional pressure reduction control in response to an increase in pressure or more is used.

Proportional pressure reducing control valve 8 in the brake system
When the 0R (or 80L) is provided, it may be provided in the middle of the pipe, or, because some of the pipes may be omitted, it may be provided so as to be integrated with an adjacent device in terms of pipe connection. FIG. 2 shows a proportional pressure reducing control valve 80R.
It shows a case where is integrated with the anti-skid control valve device 61R. The anti-skid control valve device 61R is, for example, as disclosed in Japanese Patent Laid-Open No. 62-253554,
Since its internal structure is well known, detailed description thereof is omitted here. The anti-skid control valve device 61R is provided with two solenoid valve mechanisms, a holding valve and an exhaust valve (both not shown), in the housing 600, and can be switched into three modes of boosting (filling), holding, and depressurizing (relaxing). Replace The switching is performed by the electronic control unit 20, and the connector 610 for electrical connection with the unit 20 is located on the side portion of the housing 600. The housing 600 includes a relay emergency valve 25.
In addition to the inlet 620 connected to the side, the outlet 630 connected to the proportional pressure reducing control valve 80R side, the exhaust port 64 leading to the atmosphere.
There is 0. On the other hand, the limiting quick release valve which is the proportional pressure reducing control valve 80R has a valve stem 810 and a stepped plunger 820 in a housing 800, an exhaust valve 811 at one end of the valve stem 810, and a supply valve 812 at the other end. It is configured. Housing 80 for this limiting quick release valve 80R
0 should be connected to the first outlet 831 which should be connected to the follower (brake chamber 51R) whose axial load is lighter during braking, and the follower (brake chamber 52R) whose brake axial load should be larger during braking. In addition to the second outlet 832, there is an exhaust port 840 that communicates with the atmosphere.

In this limiting quick release valve 80R, the first chamber 821 is at the first outlet 831,
Further, the second chamber 822 communicates with the second outlet 832, respectively, but in view of the relationship with the antiskid control valve device 61R, the second chamber 822 and the second outlet 832 are connected to the outlet 6
I have to call 30. In this example, T
This is made possible by using a bolt member 900 having a V-shaped inlet passage 910 formed therein. That is,
A bolt through hole 850 penetrating laterally is provided in the housing 800 on the limiting quick release valve 80R side, and the opening of the bolt through hole 850 faces the outlet 630 of the housing 600 on the anti-skid control valve device 61R side. There is. Therefore, the housing 800 on the limiting quick release valve 80R side
The rib 880 of the anti-skid control valve device 61R is jointly tightened with the rib 680 of the housing 600 on the anti-skid control valve device 61R side, and the bolt member 900 is passed through the bolt through hole 850 so that the outlet 6 on the anti-skid control valve device 61R side is closed.
Put a sealing member 930 such as a gasket in the portion of 30,
The limiting quick release valve 80R and the anti-skid control valve device 61R can be integrally connected. Inlet passage 91 in bolt member 900 for coupling
Since there is 0, the integration of the two valve devices and the piping can be performed at the same time.

Now, the stepped plunger 82 of the limiting quick release valve 80R which is a proportional pressure reducing control valve.
Note the 0 part. The stepped plunger 820 is
It is an assembly of an outer piston 8201 and an inner piston 8202. Outer and inner pistons 8201, 8
Reference numeral 202 denotes a stepped structure, and each has a large diameter portion 8201.
a, 8202a and small diameter portions 8201b, 8202b. Both pistons 8201 and 8202 have a small diameter portion 8201.
b and 8202b are slidably fitted together. Since the seal ring 8203 is provided at the outer peripheral portion of each large diameter portion 8201a, 8202a and the connecting portion of the small diameter portions 8201b, 8202b, the stepped piston 820
The outer peripheral side and the inner peripheral side are densely partitioned from each other. The outer chamber 8204 is constantly in communication with the atmosphere, and the return spring 8205 for the outer piston 8201 is housed therein. The spring force of the return spring 8205 is the return spring 82 for the inner piston 8202.
Greater than that of 06.

Referring to the brake performance diagram of FIG. 3,
Let us clarify the control characteristic of the proportional pressure reducing control valve 80R including both the outer and inner pistons 8201 and 8202. In FIG. 3, a straight line Lf with a small inclination shown by a broken line is a front side control characteristic proposed by the previous proposal, and a straight line Lr with a large inclination shown by a solid line is a rear side control characteristic proposed by the previous proposal.
In the proportional pressure reducing control valve 80R inserted on the front side, only the inner piston 8202 moves under a relatively low pressure corresponding to a brake when the vehicle is empty. Inner piston 820
The effective pressure receiving area of 2 is smaller on the input side than on the output side. Therefore, as in the case of the previous proposal, the brake pressure reduced at a constant rate with respect to the rear side is supplied to the front side. However, when the pressure introduced into the chamber 822 reaches the predetermined value P, the outer piston 8201 engages with the inner piston 8202, and the two move integrally. The predetermined value P is determined by the input-side effective pressure receiving area of the outer piston 8201 and the spring force of the return spring 8205. Both outer and inner pistons 8201, 8
When the 202 moves integrally, the stepped piston 8
The effective pressure receiving area of 20 is set so that the sum of the input side of the outer piston 8201 and the input side of the inner piston 8202 is equal to or larger than the output side of the inner piston 8202. Therefore, the proportional pressure reducing control valve 80R
Under a relatively high pressure corresponding to the brake when the vehicle is loaded, the decompression control is stopped and the control characteristic becomes similar to that on the rear side.
That is, the proportional pressure reducing control valve 80R is
-The control characteristic which follows ABC is shown. As a result,
Appropriate braking force can be obtained not only when the vehicle is empty but also when the vehicle is loaded.

In the embodiment described above, the proportional pressure reducing control valve having the outer piston 8201 newly added is used. However, instead of using the outer piston 8201, only the stepped inner piston 8202 is used. As shown in FIG.
As shown in FIG.
It is also possible to control the pressure acting on the valve by means of the pilot type auxiliary valve 1000 and to invalidate the proportional pressure reducing control. The auxiliary valve 1000 sets the step portion 8202s to the atmospheric pressure until the input pressure reaches the predetermined pressure, and when the predetermined pressure is reached, sets the step portion 8202s to the same pressure as the input pressure and invalidates the proportional pressure reduction control. Auxiliary valve 1 in FIG.
In 000, since the input pressure is the pilot pressure, the step portion 8202s is passed through the manual switching valve operated by the driver.
Compared to the case where the control pressure is applied to the switch, the switching valve is not forgotten to be switched.

Further, in the embodiment shown in the drawing, the case of front axis sensing is shown, in which the left and right sides are independent of each other. However, the rear axis sensing type also has a common left and right channel. The present invention can be applied to the type of. Further, the present invention can be applied not only to a 2-axle semi-trailer but also to a 3-axle or 4-axle full trailer.

[0015]

According to the present invention, as the proportional pressure reducing control valves 80R and 80L to be inserted, those having switching means for invalidating or validating the proportional pressure reducing control are used, and the antiskid control valve devices 61R and 61L are used. The proportional pressure reduction control is invalidated when the introduced pressure rises above a predetermined pressure, so that the problem of insufficient braking force during loading can be prevented while effectively preventing wheel lock when the vehicle is empty. Can be effectively avoided.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a brake system according to the present invention.

FIG. 2 is a piping diagram of essential parts including a cross-sectional structure of a proportional pressure reducing control valve.

FIG. 3 is a diagram showing an example of a brake performance diagram.

FIG. 4 is a piping diagram of essential parts showing another embodiment of the present invention.

[Explanation of symbols]

20 electronic control unit (discrimination circuit) 25 relay emergency valve (main engine) 26 air reservoir 41L, 41R; 42L, 42R wheels 51L, 51R; 52L, 52R brake chamber (follower) 61R, 61L anti-skid control valve device 71R , 71L Sensor 80R, 80L Proportional pressure reducing control valve 8201 Outer piston 8202 Inner piston 1000 Auxiliary valve

Claims (1)

[Claims] 1. A main engine for sending the pressure of an air reservoir as a brake pressure according to a driver's operation, and a plurality of followers for respectively applying a brake to wheels arranged in a front-rear direction of a vehicle body, These followers are connected to the main drive through one brake system, and in the one brake system, from the main drive based on a command from a determination circuit that monitors and determines the rotation state of the wheels. An anti-skid control valve device for adjusting the pressure of all of the followers in common, a part of the plurality of followers is directly connected to the anti-skid control valve device, and the remaining followers are In a brake system for a multi-axle trailer in which is connected to the anti-skid control valve device via a proportional pressure reducing control valve, the proportional pressure reducing control valve disables the proportional pressure reducing control. Alternatively, the brake system for a multi-axle trailer is provided with a switching means for enabling the proportional pressure reduction control when the pressure introduced from the anti-skid control valve device rises above a predetermined pressure.