JPH05112227A - Brake device of car - Google Patents

Abstract

PURPOSE:To accomplish a brake system for use in the brake device of a car, in which particularly no fluid pressure such as oil pressure, pneumatic pressure, etc. CONSTITUTION:A brake device for car is equipped with a rotor coil 5 to rotate in a single piece with a member 3 to be braked, a stator coil 6 located in the neighborhood of the rotor coil 5 and fixed to the inner surface of stator 1, a motor-driven actuator 8 fitted with a friction member 7 to make frictional contact and separation with/from the rotating foremost face of the rotor 3, a stroke stamp force sensor 11 connected with a brake pedal 10, and a control circuit 12 to control them. A judgement is passed in compliance with the depth and manner of stamping the pedal 10, whether the electromagnetic force braking due to current feed to the rotor coil 5 is to be done or a combination is formed with the disc braking (or drum braking) the motor-driven actuator 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking device for a vehicle such as an automobile, and more particularly to a technique effective for realizing a braking system which does not use fluid pressure such as hydraulic pressure and pneumatic pressure.

[0002]

2. Description of the Related Art As a braking device for a vehicle of this type, a drum brake, a disc brake, etc. are generally used.
The pressure generated by the depression force of the brake pedal is amplified and transmitted by hydraulic piping to operate the brake pad.

[0003]

However, in the braking system using the hydraulic pipe as described above, the braking efficiency is not always good because the loss of the pressure transmitted in the pipe is large. Moreover, in order to secure a certain piping space, there is no degree of freedom in the layout design of the parts in the vehicle body.

Further, since braking depends only on the frictional force between the member to be braked (rotor) and the friction member (pad), noise during braking is large, and if a braking state continues for a long time, a fade phenomenon may occur, which is dangerous. In addition, a separate special actuator is required to perform auxiliary braking such as anti-lock control system or traction control, which not only increases the number of parts but also increases the cost.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a vehicle braking system capable of highly reliable braking control without the need for brake piping.

[0006]

The present invention uses the following means as a vehicle braking device. That is, the braked member 3 that is rotated integrally with the braked shaft 2 in the stator 1
A rotor coil 5 disposed in the center of the surface of the braked member 3 and rotated integrally with the braked member 3 and energized by the stator 1, and a rotor coil 5 provided in the vicinity of the rotatable rotor coil 5 to the stator 1. An electric actuator 8 including a fixed stator coil 6, a friction member 7 that frictionally comes into contact with and separates from the rotating tip surface of the braked member 3, a stroke pedal force sensor 11 connected to a brake pedal 10, and The rotor coil 5, the stator coil 6, the electric actuator 8, and the control circuit 12 electrically connected to the stroke pedal force sensor 11 are configured to be provided. The first braking control in which the stroke pedal force of the brake operation is detected, and this is arithmetically processed to energize the rotor coil 5. Or it was adapted to determine the second brake control or for performing energization of the electric actuator 8 performs power supply to the rotor coil 5.

[0007]

According to the above-mentioned means, the brake braking can be realized only by the electric signal from the control circuit 12 without using the brake pipe, so that the efficient brake braking can be realized without causing the pressure loss. At the same time, only the wiring space needs to be considered instead of the piping space, and the degree of freedom in arranging components in the vehicle body is improved.

In addition, when braking the brake, the electric actuator 8 (disk brake or drum brake)
And the electromagnetic force (electromagnetic brake) generated by power supply to the rotor coil 5 are used to determine whether the disc brake (or drum brake) and the electromagnetic brake need to be gently braked based on the stroke pedal force of the brake pedal 10. By automatically determining whether or not the combined rapid braking is required, it is possible to realize appropriate and reliable brake braking according to the situation where the braking is required.

For example, when the driver gently depresses the brake pedal 10, braking is performed only by the electromagnetic brake so that the braking is realized at a deceleration that is normally expected by the driver. When the brake pedal 10 is suddenly depressed, it is necessary to perform sudden braking, and both the electromagnetic brake and the disc brake (or the drum brake) are activated to realize the sudden stop, which may cause a danger such as a collision. To avoid.

During the braking, the energizing on / off switch 14 of the control circuit 12 may be closed to use the regenerative current generated in the stator coil 6 for charging the battery 13. Current generated by the stator coil 6 that functions as a generator by the rotation of the braked member 3 (regenerative current)
Is applied to an electric load such as the battery 13, the braking force by the electromagnetic force is increased, and the battery 13 can be used for a long time.

Further, the control circuit 12 inputs a signal from, for example, the speed sensor 15, and forcibly performs caliper control when the traveling speed of the vehicle becomes a predetermined value or less while maintaining the brake braking. It may be possible to switch to disc brake braking (or drum brake braking) in which braking is performed only by a signal. That is, since the electromagnetic brake realizes braking by electromagnetic force, it is suitable for relatively gentle braking, but is not suitable for sudden stop or stop control from low speed running. Further, the disc brake (or drum brake) is suitable for rapid braking and stop braking, but not for many uses because of the contact structure between the pad 7 and the braked member 3.

According to the present invention, the brake required by the driver is properly recognized according to how the brake pedal 10 is depressed, and the electromagnetic brake and the disc brake (or the drum brake) are selectively used.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic explanatory view showing a brake braking system which is an embodiment of the present invention, and FIG. 2 is a control flow chart in a control circuit.

The system configuration of this embodiment has a stroke pedal force sensor 11 connected to a brake pedal 10 as shown in FIG. This stroke pedal force sensor 1
Reference numeral 1 denotes a detector that detects the pedaling force of the brake pedal 10, that is, the amount of movement of the brake pedal 10 per unit time and the amount of depression of the entire brake pedal.

The stator 1 has a shaft 2 as a braked shaft which axially penetrates into a housing having an oval cross section and is rotated in association with wheels. A rotating disk-shaped rotor 3 (member to be braked) is fixed.

A rotor coil 5 that rotates integrally with the rotor 3 is mounted near the center of the rotor 3 in the axial direction. The rotor coil 5 has a brush 4 whose base end is fixed to the inner surface of the stator 1. The tip of the rotor is in contact with the rotor coil 5 and the outside (control circuit 12) can be energized.

Inside the stator 1, the rotor coil 5 is sandwiched between the front and rear sides of the rotor coil 5 in the axial direction so that the rotor coil 5 is sandwiched between the rotor coil 5 and the rotor coil 5 without contacting the rotor coil 5. It is fixed.

An electromagnetic brake is constituted by the rotor coil 5 and the stator coil 6 described above. That is, by supplying electric power from the outside through the brush 4, an electromagnetic force is generated in the rotor coil 5, and this electromagnetic force generates a rotational force in the opposite direction of the rotor 3, that is, the shaft 2, and brake braking by the electromagnetic force is performed. Will be realized.

The coil material of the rotor coil 5 and the stator coil 6 is preferably a low resistance conductive material, and particularly by using a superconducting material, the size and weight of the entire braking device can be reduced.

A part of the rotating tip of the rotor 3 is inserted into a caliper 16 provided inside the stator 1, and an electric actuator 8 driven by a motor is installed in the caliper 16. A pad 7 (friction member) is provided at the tip of the electric actuator 8, and the pad 7 is operated by the operation of the electric actuator 8 so that the pad 7 sandwiches the tip surface of the rotor 3 and makes frictional contact, thereby realizing disc brake braking. It has a structure.

The electric actuator 8 is provided with a mechanism for converting electric power into hydraulic pressure in the caliper 16, for example, Japanese Patent Application No. 3-2 already proposed by the applicant.
The one described in No. 21872 or the one provided with a mechanism for directly pressing the pad with an electric force can be used.

The control circuit 12 is, for example, an 8-bit or 16-bit processing microprocessor and RAM / RO.
As shown in FIG. 1, the microcomputer system is provided with a memory such as M. As shown in FIG. 1, the detection signals from the stroke pedal force sensor 11, the vehicle body speed sensor 15 and the like are input, predetermined arithmetic processing is performed, and a caliper control signal and And a rotor coil power supply signal.

Further, the control circuit 12 is provided with an energization opening / closing switch 14 for the battery 13, and also controls the opening / closing operation of this switch. A detailed description of the vehicle body speed sensor 15 is omitted, but a Doppler radar or the like can be used.

Next, the control procedure of the control circuit 12 in this embodiment will be described with reference to FIG. First, when the detection signal from the stroke pedal force sensor 11 is input (step 20
1), the control circuit 12 calculates the deceleration desired by the driver corresponding to the detected pedal effort (202). The deceleration may be calculated, for example, by preparing a correspondence table of deceleration values preset for the pedaling force in the RAM or ROM and outputting the deceleration corresponding to the input detection signal.

Next, it is determined whether or not the deceleration calculated above is equal to or less than a threshold deceleration that is a reference. Here, for example, the deceleration when the driver steps on the brake pedal 10 in the expectation of a gentle deceleration in normal traveling is, for example, 0.2 G, and this threshold deceleration may be 0.2 G. ..

In this case, in the process of the judgment step 203, the deceleration calculated in the step 202 is 0.2.
If it is equal to or less than G, only the rotor coil power supply signal is output and only the electromagnetic brake is operated to perform relatively gentle braking (204).

At this time, the control circuit 12 closes the energization opening / closing switch 14 and energizes the rotor coil 5 and the battery 13 at the same time as the operation of the electromagnetic brake. As a result, the rotor coil 5 is energized with the battery 13, which is an electrical load, and an electromagnetic force that opposes the rotation of the stator coil 6 is generated. The rotating force of the rotor 3 is further suppressed by this electromagnetic force. At this time, the stator coil 6 functions as a generator, so to speak,
A regenerative current is generated and the battery 13 is charged through the energization switch 14 which is closed.

On the other hand, in the above-mentioned judgment step 203, the deceleration calculated is 0.2 G which is the threshold deceleration.
If it is determined that the driver needs relatively rapid braking, the control circuit 12 outputs the rotor coil power supply signal and the caliper control signal to output the electromagnetic force. Performs synergistic braking of the brake and the disc brake (electric actuator 8) (20
5) Realize rapid braking.

Next, by inputting a signal from the vehicle body speed sensor 15, it is judged whether or not the speed of the vehicle is below a threshold speed (for example, 10 kilometers per hour) (206). If the brake pedal 10 is continuously depressed in step 207 (207), the processing from step 201 onward is repeated.

When the depression of the brake pedal 10 is released, the brake braking is stopped (20
8). In step 206, when the vehicle speed is equal to or lower than the predetermined value, only the caliper control signal is output and the rotor coil 5 power control signal is turned off. As a result, only the disc brake (electric actuator 8) is activated (209).

In the next step 210, it is detected whether or not the brake pedal 10 is continuously depressed (21
0) If the brake pedal 10 is still depressed, the braking by the disc brake is continued. If the brake pedal 10 is not depressed, the disc brake (electric actuator 8) is released (211).

As described above, in the present embodiment, when the driver expects a relatively gentle brake braking depending on how the driver depresses the brake pedal 10, braking is performed only by the electromagnetic brake. Do (203-20
4) When sudden braking is required for avoiding a collision, the electromagnetic braking and the disc brake (electric actuator 8) are used together to perform the braking (203 to 20).
5). Then, when the vehicle speed becomes sufficiently low, the braking is switched to the disc brake (electric actuator 8) only (206 to 209) to stop the vehicle.

As described above, by selecting the optimum brake braking according to how the brake pedal 10 is depressed and the speed of the vehicle, stable and highly safe vehicle steering can be achieved.

Further, according to this embodiment, a separate actuator is used for auxiliary braking, for example, anti-lock braking for preventing slip during vehicle braking, traction control for preventing slip during acceleration, and the like. Instead, it can be realized with only a small addition of software in the control circuit 12. Therefore, a vehicle with high running safety can be realized with a small number of parts and at low cost.

In the description of the embodiment, the threshold deceleration is set to 0.2 G and the threshold speed is set to 10 km / h. However, the values are not limited to these values.

In the embodiment, the Doppler radar is mentioned as an example of the speed sensor, but the wheel (or shaft 2) is used.
A speed sensor may be attached directly to the. Alternatively, the rotor 3 may have a drum shape, and a drum brake including the electric actuator 8 may be used.

[0037]

According to the present invention, by using both the electromagnetic brake and the disc brake by the electric actuator, it is possible to perform highly reliable brake control without the need for brake piping.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing a brake braking system which is an embodiment of the present invention.

FIG. 2 is a control flow chart showing a braking procedure in a control circuit in the embodiment.

[Explanation of symbols]

 1-stator 2-braked shaft (shaft) 3-braked member (rotor) 4-brush 5-rotor coil 6-stator coil 7-friction member (pad) 8-electric actuator 10 Brake pedal 11 Stroke pedal force sensor 12 Control circuit 13 Battery 14 energizing switch 15 Speed sensor 16 Caliper

Claims (3)

[Claims] 1. A braked member (3) which rotates integrally with a braked shaft (2) in a stator (1), and a rotor coil (5) which rotates integrally with the braked member (3). A frictional contact / separation operation is performed between the stator coil (6) fixed to the stator (1) and provided near the rotatable rotor coil (5), and the rotating tip surface of the braked member (3). An electric actuator (8) having a friction member (7), a stroke pedal force sensor (11) connected to a brake pedal (10), the rotor coil (5), and a stator coil (6).
An electric actuator (8) and a control circuit (12) electrically connected to the stroke pedal force sensor (11), wherein the control circuit (12) is operated by the driver from the stroke pedal force sensor (11). The first braking control in which the stroke pedal force of the brake operation is detected, and this is arithmetically processed to energize the rotor coil (5), or the rotor coil (5)
To the electric actuator (8)
A braking device for a vehicle, characterized in that it is determined whether to perform a second braking control for energizing the vehicle. 2. The control circuit (12) comprises a battery (1
3) is provided with an energization opening / closing switch (14), the energization opening / closing switch (14) is closed during braking, and the stator coil (6) and the battery (13) are energized to generate electricity in the stator coil (6). The vehicle braking system according to claim 1, wherein a regenerative current is used to charge the battery (13). 3. The electric actuator (8), wherein the control circuit (12) receives the input signal from the speed sensor (15) when the traveling speed of the vehicle is below a certain value.
The vehicle braking apparatus according to claim 1, wherein the third braking control is performed only by energizing the vehicle.