JPS6045454A - Car brake system - Google Patents

Abstract

PURPOSE:To prevent slip of wheel due to increase of adhesion factor between the wheel and rail by subtracting the brake force corresponding to the down slope from specific brake force upon facing to down slope. CONSTITUTION:A command signal corresponding to predetermined brake force provided from a commander 1 and a deceleration detecting signal provided from a deceleration detector 2 are compared in a deceleration controller 3 to produce a deceleration command signal Vbeta. While a slope signal theta provided from a slope detector 4 is converted in a converter 5 into a conversion signal tantheta which is provided to a multiplier 7 to be multiplied with a car load signal W provided from a car load detector 6 to produce a slope component signal Wbeta. Then the car load conditions are added to the deceleration command signal Vbeta by a load controller 8 to produce a command correction signal Vbeta0 while the slope component signal Wbeta is subtracted from the command correction signal Vbeta0 in a subtractor 9. Consequently, a brake force signal corresponding to the horizontal state is produced to apply predetermined brake force onto the wheel 11 from a brake force generator 10.

Description

[Detailed description of the invention] The present invention relates to a vehicle brake system.

A conventional one is shown in FIG. In the figure, a command signal Vp corresponding to a predetermined braking force commanded by a driver from a command device (1) and a vehicle deceleration detection signal β detected by a deceleration detector (g) are sent to a deceleration controller. Comparing (2), if the deceleration is insufficient, add the shortfall △β to the command signal Vp to make Vβ = Vp + △β, and if the deceleration is excessive, set Vβ = Vp - △β. Transmit Vβ to each car. Each vehicle receives Vβ and outputs a brake force generator (9
) K controls the electric brake or air brake to act on the wheel αυ to generate a predetermined deceleration. By feedback-controlling this deceleration via the deceleration detector (2) and automatically correcting changes in braking force due to the friction coefficient between the wheels and brake shoes,
It was controlled so that a constant deceleration was always obtained in response to commands. In this case, the braking force required to achieve the necessary deceleration does not change even though the wheel diameter and friction coefficient are corrected.
Adhesion between wheels and rails is basically irrelevant.

However, when the vehicle goes down a slope, the braking force for the slope is insufficient, so the control increases the deceleration command to increase the braking force, which increases the adhesion coefficient used between the wheels and the rail, making it difficult to skid. more likely to occur.

The braking force F on a downhill slope is expressed as equation (1).

Here, W is the weight (ton), and W' is the inertial equivalent weight (t
on) yt acceleration of gravity, β is deceleration (Km/h/s)
, θ is the slope angle, and 51 degrees slope (010O'').

For example, when a 50 ton vehicle is decelerated to a deceleration of 3.5%/h/s, the braking force F1 is F1=(50+
2S)
If 4 and Nane have the same conditions with a slope of 800100,
Brake force F2 is F2 (60+25) x 8578
52B +50 x 80/1000 = 6.71
ton, and the adhesive coefficient μ2 used is μ2 = 6.71
Since 150 = 0.184, skidding is more likely to occur.

The present invention has been made in view of the above, and provides a brake device for a vehicle that can prevent skidding on a downhill slope by subtracting a braking force corresponding to the amount of downhill slope from a commanded braking force.

The figures will be explained below. In FIGS. 2 and 8, (1) is a command signal Vp corresponding to a predetermined braking force.
(2) is a deceleration detector that outputs a deceleration detection signal β; (3) is a deceleration detector that compares the command device 8Vp and the deceleration detection signal β and outputs a deceleration command signal Vβ When the deceleration is insufficient, the controller calculates the shortage △β as Vβ= Vp
+Δβ, and when it is excessive, Vβ=Vp-6β. (4
) is a slope detector consisting of a gyro or the like that detects a downward slope and outputs a slope signal θ, and (5) is a slope detector that converts the slope signal θ into a converted signal t.
(6) is a load detector that detects the vehicle load and outputs a load signal of 8W; (7) is a converter that converts to anθ.
A multiplier (8) multiplies the load condition number W and outputs the gradient signal Wβ, and (8) adds the vehicle load condition to the deceleration command signal Vβ in accordance with the vehicle load to generate a command correction signal "!8". A variable load controller that outputs −vβ0, (9) is a subtracter that subtracts the gradient signal Wβ from the command correction signal gvβ0, and outputs a brake force signal corresponding to the horizontal state.α1 is from the subtracter (9) This is a brake force generator that generates a predetermined brake force and applies it to the wheel (1) based on the brake force signal of the brake force signal.

In the above configuration, W-tanθ is obtained by multiplying the conversion signal tanθ and the load signal 8w by the multiplier (7), so if this is subtracted from the command correction signal Vβ0, the brake force corresponding to the horizontal state is obtained. I got a signal. The brake force generator OQ is controlled by the conoflake force signal, and a predetermined brake force is applied to the wheel α0.

In the above embodiment, when the slope angle θ is small, the case θ
Since it can be regarded as nθ, it is not necessary to provide the converter (5).

According to this invention, by subtracting the braking force corresponding to the amount of downhill slope from the commanded braking force, it is possible to prevent the wheels from sliding.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional vehicle brake system, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is an explanatory diagram showing the relationship between a command signal and a steering wheel angle. In the figure, (1) is a command device, (2) is a deceleration detector,
(4) is a gradient detector, (6) is a load detector, (7) is a multiplier, and (9) is a subtracter. Note that the same reference numeral t in each figure indicates the same or equivalent part. Agent Masuo Oiwa

Claims (1)

[Claims] (1) A command device that outputs a first signal corresponding to a predetermined braking force, a deceleration detector that detects the deceleration of the vehicle and outputs a second signal, the first signal and the $2 signal a deceleration controller that outputs an eighth signal by comparing the slope of the vehicle; a slope detector that detects a downward slope and outputs a fourth signal; and a slope detector that detects the load of the vehicle and outputs a fifth signal. a load detector that outputs a load detector; a multiplier that multiplies the fourth signal and the fifth signal and outputs a sixth signal; a multiplier that outputs a sixth signal;
A vehicle brake device comprising a subtracter that subtracts the sixth signal from the signal and outputs a seventh signal.