JPS63242764A - Electric type brake control device for vehicle - Google Patents

Abstract

PURPOSE:To reduce the size and the weight of a device and to perform fine control, by a method wherein the drive direction of an electric motor means is decided by means of signals from a brake pedal stepping force detecting means and a brake reaction force detecting means, and a brake pad is pressed and separated. CONSTITUTION:A control 4 compares a step-up force lambda of a brake pedal 5 with a signal from a reaction force sensor 1B for detecting the reaction force of a brake pad 1F. Based on a comparing value, the drive direction of a DC motor 1C secured to a machine frame 1A is decided, and the brake pad 1F is pressed and separated against and from a brake disc 3 through a screw 1D and a pad ash 1E to generate a brake force responding to a brake step-on force. In this constitution, since a proper brake force is ensured and electric control is performed, response to brake control is rapid, and fine control is practicable. Further, a hydraulic mechanism is eliminated and the size and weight of a device are reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a brake control device for a vehicle, and particularly to a control device in an electric brake unit.

(Prior Art and Problems to be Solved by the Invention) Hitherto, hydraulic systems have been widely used for vehicle brakes due to their large load characteristics.

In this conventional hydraulic vehicle brake, power is basically transmitted to the brake pads through a path such as: brake pedal depression force by the driver -> master cylinder valve = 2MS oil pressure - piping -> wheel cylinder oil pressure Pw. For this reason, after the driver depresses the brake pedal, the wheel cylinder pressure P is applied to the brake pads.
There was a problem in that it took a long time until the load was applied.

Further, in this hydraulic vehicle brake, the weight and size of the hydraulic system are large, making it difficult to downsize. In addition, when trying to perform various brake force controls (9) such as anti-skid brakes depending on driving conditions, it is necessary to place control valves in various locations, resulting in a very complicated structure. There were drawbacks.

Furthermore, the biggest drawback of this hydraulic brake is that when controlling the braking force, it is difficult to detect the magnitude of the applied braking force, which makes fine control difficult.

As a brake, it had the drawback of not being able to exert 100% safe braking force.

The present invention uses an electric brake in view of the drawbacks of the conventional hydraulic brake as described above.

By providing this electric brake control device, it is possible to achieve a reduction in size and weight, and the purpose is to enable detailed control when performing various brake controls depending on driving conditions.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes an electric means for pressing a brake pad against and away from a brake disk depending on the driving direction, and switching the driving direction of this electric means. A switching means, a detection means for detecting the brake pedal depression force, a detection means for detecting the brake reaction force generated on the brake pad, and a drive direction of the electric means by comparing the detected brake pedal depression force and the brake reaction force. and a controller that determines the switching means and switches the switching means.

(Function) In this electric brake control device for a vehicle, braking between the brake pad and brake disc is performed electrically instead of hydraulically, and the brake pad and brake disc are pressed into contact and separated by electric means. It will be done.

As this electric means, for example, a brake pad may be attached to the tip of a screw shaft that is moved back and forth by a forward/reverse drive of a DC motor, and the pad may be pressed into contact with and separated from a brake disc. The driving direction of this electric means is switched by the switching means, and the brake pad is pressed into contact with or separated from the brake disc.

The controller compares the brake pedal depression force detected by the brake pedal depression force detection means with the brake reaction force detected by the brake reaction force detection means, and determines the driving direction of the electric means based on this comparison value. Then, the switching means is switched. In other words, when the brake pedal depression force is larger than the brake reaction force, the electric means is driven in the direction of pressing the brake pad against the brake disc, and when the brake reaction force increases and becomes larger than the brake pedal depression force, the electric means is driven to press the brake pad against the brake disc. The driving direction of the means is switched, the pressing force between the brake pad and the brake disc is relaxed, and the braking force is weakened.

In this way, an appropriate braking force is ensured, and since it is electrically controlled, the braking response is quick.

(Example) The present invention will be described in more detail below based on an example shown in one drawing.

In Figures 1 and 2, the brake unit 1 is connected to the vehicle body 2.
The brake unit 1 has a reaction force sensor IB formed by a strain gauge installed in a recess formed in the second part of the machine frame IA. Further, a DC motor IC is fixed to the machine frame IA, and a screw ID screwed into the center of the DC motor IC is moved back and forth in its axial direction.

A brake pad IF is attached to the tip of the screw ID via a pad ash IE, and the brake pad IF can be freely pressed against and separated from the brake disc 3 by the forward and backward movement of the screw 10.

The controller 4 receives a signal λ when the brake pedal 5 is depressed, and controls the DC motor I according to the amount of depression of the brake pedal 5.
A drive signal is output to C. Further, a brake reaction force signal is fed back to the controller 4 from the reaction force sensor 1B of the brake unit 1.

The configuration for controlling the rotational direction of the DC motor IC by the controller 4 is as shown in FIG. The input converted signal V
λ is manually input to the signal comparison section 8. Similarly, after the brake reaction force F is detected (b) by the strain gauge sensor 9 and input to the F signal converter 1o and converted into a conversion signal VP,
The signal is output to the signal comparison section 8.

The signal comparison section 8 outputs a comparison signal to the motor drive logic section 11, and this motor drive logic section 11 performs DC control by on/off control of four transistors 12a to 12d.
Switches the rotation direction of the motor IC (switching means). For example, turn on transistors 12a and 1.2d, turn on transistor 12b! By keeping 2c off, the current flows through transistor 12a - DC motor IC - transistor 1
2d, the DC motor Ic rotates clockwise (arrow
). Furthermore, if the transistors are turned on and off in the opposite manner as described above, the DC motor 10 rotates to the left (arrow Y).

Next, the control of the vehicle electric brake will be explained based on the flow chart shown in FIG.
After the brake pedal depression force is detected (a) and signal converted (C), this converted signal Vλ is sent to the signal comparator 8.
compared with the conversion signal VP of the brake reaction force F (d,
e, f'). At the start of this braking, the brake reaction force F is zero, so Vλ>IVFI(d
), and the above-mentioned on/off control of the transistor is performed by this comparison signal to rotate the DC motor 1C clockwise and advance the screw ID to tighten the brake pad IF to the disc 3 (i) Brake braking I do.

When braking starts due to the pressure bond between the brake pad IF and the disc 3, a brake reaction force F is generated in the brake unit 1 as shown in FIG. 1, and this brake reaction force F is detected by the reaction force sensor IB. (b). The detected brake reaction force F is.

The F signal converter 10 converts the converted signal V I) into a converted signal (j
) and input to the signal comparison section 8.

In the comparison between the brake pedal depression conversion signal Vλ and the brake reaction force conversion signal vF in the signal comparison unit 8, it is found that Vλ is still Vλ.
>IVFI(d), motor drive logic section [l continues clockwise rotation of DC motor 1C L (1), Vλ-
When it reaches 1vp+(e), the DC motor IC is stopped and the tightening by the brake pad IF is stopped (l]). When Vλ<IVFI(1'), the DC motor IC is rotated counterclockwise to loosen the brake pad IF (g
).

In the above embodiment, a strain gauge is used as the 2 reaction force sensor IB, but it is also possible to use a ceramic piezoelectric sensor, a semiconductor load sensor, a load cell, etc. In this case, the As shown by reference numeral IB' in FIG. 1, it is attached to the joint between the brake unit 1 on the vehicle body 2 side and the machine frame 18.

Figures 6 and 7 show other embodiments of the method of connecting the vehicle body and the brake unit. In contrast to the embodiment shown in Figure 1 in which the brake unit was attached to the vehicle body with a single connecting nut, this In this embodiment, it is attached by two connecting nuts 3', and a reaction force sensor IB'', which is a strain gauge, is directly attached to the connecting nuts 3'.Other constructions are the same as in the previous embodiment. Further, as the reaction force sensor, a ceramic piezoelectric sensor, a semiconductor load sensor, a load cell, etc. can be used as in the previous embodiment (reference numeral 2113' in FIG. 6).

FIG. 8 shows still another embodiment of the present invention. In the embodiments of FIGS. 1 and 6, a hollow drive motor is used, but in the case of this embodiment, the output shaft of the motor 31 is 3
1a is connected to a screw 33 of the brake pad 32 via a roller bearing 34, and the brake pad 3z and brake disc 35 are engaged and disengaged. The reaction force sensor 3G is a ceramic piezoelectric sensor,
Semiconductor pressure sensor or load cell is used in one machine frame 3
0 and the roller bearing 34 to detect the pressing force of the brake pad 32 as a brake reaction force.

FIG. 9 is a flowchart 1 showing control by the brake control device, which is basically the same as the embodiment described above, and detects the pressing force of the brake pad as a brake reaction force (
b') L, After converting this into a signal (j), compare it with the converted signal of the brake pedal depression force (d'), (e')
, (f”) to perform brake control.

(Effects of the Invention) As described above, in the present invention, since brake control is performed by electric means, the braking force rises from the depression of the brake pedal very quickly compared to the conventional hydraulic type. It is also lighter and more compact than the hydraulic type. Furthermore, it is easy to detect the brake force during braking, and by this detection, brake force control such as anti-skid brake can be easily performed, and 100% safe control force can be ensured. Furthermore, the structure for this purpose is simple.

Furthermore, when manually transmitting drive signals from the controller to the brake unit, the brake characteristics can be improved by using a compensation circuit that compensates for signal advance and delay, etc., and provides greater freedom in control compared to hydraulic types. It is possible to increase the degree further.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
3 is a circuit diagram showing the control system in the same embodiment, FIG. 4 is a block diagram showing the switching means and its control system in the same embodiment, and FIG. 5 is a circuit diagram showing the control system in the same embodiment. FIG. 6 is a configuration diagram showing another embodiment of the present invention, FIG. 7 is a sectional view taken along the line ■-■ in FIG. 6, and FIG. A sectional view showing the embodiment, FIG. 9 is a flow chart in the embodiment of FIG. 1, l゛...Brake unit 2.2°...Vehicle body 1B, IB', 21B, 21B', 3B...
Reaction force sensor Ic, 31...DC motor IP, 32...Brake pad 3.35...Brake disc 4...Controller 12a, 12b, 12c, 12d...) Langister Applicant: Aisin Seiki Co., Ltd. Patent Attorney Asami Kato (1 other person) Figure 4 Figure 6 ■-

Claims (1)

[Claims] An electric means for pushing the brake pad into contact with and separating it from the brake disk depending on the driving direction, a switching means for switching the driving direction of the electric means, a detection means for detecting the brake pedal depression force, and a means for detecting the brake reaction generated on the brake pad. For a vehicle, comprising: a detection means for detecting force; and a controller for comparing the detected brake pedal depression force and the brake reaction force to determine the driving direction of the electric means and switching the switching means. Electric brake control device.