KR100658773B1 - Braking apparatus and method for vehicles - Google Patents

Abstract

The present invention provides a braking and deceleration device for a hydraulic brake of a vehicle or a moving object requiring a normal quick response, and a piezoelectric actuator as a pressurizing member for pressurizing the contact member so as to directly contact a rotating wheel or the like. Use

The piezoelectric actuator is applied to a voltage to generate a displacement, and the adjacent contact member is moved by the generated displacement is a braking device for braking is performed by the direct contact with the driving source of the wheel or the rotating member through the wheel.

Description

Braking apparatus and method for driving objects {Braking apparatus and method for vehicles}

1 is a hydraulic circuit diagram of a conventional braking device

2 is a schematic view of a braking device according to the present invention

3 is a front view of the piezoelectric actuator of the present invention.

4 is a cross-sectional view of the braking device according to the first embodiment of the present invention.

Fig. 5 is a sectional view of the displacement expanding mechanism in accordance with the second embodiment of the present invention.

Fig. 6 is a sectional view of the braking device according to the second embodiment of the present invention.

* Explanation of symbols for main parts of drawings *

A: Pressurizing device B: Contact member C: Rotating member D: Braking voltage control unit

10: piezoelectric actuator 10a: displacement expansion mechanism 20: fixed rigid body

30: brake pad 40: pad back plate 50: brake disc

60: caliper housing 12: output stage 13: preload set bolt

14: preload spring 15: fixed end

A pressure is applied to a pressurizing device and a pressurizing device for pushing a contacting member to the rotating member and a contact member for driving a conventional rotating member to rotate the wheel and driving the rotating member and bringing a close contact with the rotating member to generate a braking force by friction. The basic device configuration for braking and deceleration in a vehicle or a moving object provided with a pressure generating drive unit that provides a pressure source to generate the pressure is almost entirely dependent on the pressure generated by the fluid or gas and the generated braking force due to the generated pressure. Have been.

1 is an example of a hydraulic circuit diagram in a conventional braking system, particularly in the case of ABS.

A brake pedal (1) operated by the driver during braking, and a booster device (2) and a master cylinder (4) for amplifying the force transmitted from the pedal to generate brake hydraulic pressure are provided, and the generated brake hydraulic pressure is applied to the wheel cylinder. A normal open type (NO) solenoid valve 9a and a normal closed type (NC) solenoid valve 9b for supplying to (8) are provided.

In addition, the low pressure accumulator (LPA) 3 for storing the brake fluid supplied to the wheel cylinder 8 for a while, and the brake fluid stored in the low pressure accumulator 3 are used for the master cylinder 4 or the wheel cylinder 8. A motor 6 and pumps 7a and 7b for refluxing the reactor, and a high pressure accumulator 5 for linearly changing the pulsation of the refluxed brake fluid are provided.

In this prior art, when the driver presses the brake pedal 1 for the purpose of deceleration and stop, the force transmitted from the pedal is amplified by the booster device 2 and the brake hydraulic pressure is generated by the master cylinder 4. The brake hydraulic pressure generated in this way is supplied to the wheel cylinder 8 through a normally open solenoid valve 9a which is normally kept open, and at this time, a normally closed solenoid valve 9b installed at the output side of the wheel cylinder. The brake hydraulic pressure is applied to the wheel cylinder 8 to maintain the closed state, so that the braking force is exerted. More specifically, the hydraulic pressure that reaches the wheel cylinder 8 of the brake presses the piston in the wheel cylinder to move forward, and a pair of brake pads provided adjacent to the wheel cylinder presses the brake disc on both sides so that friction braking is performed. do.

The conventional hydraulic circuit configuration requires the installation of a complex hydraulic circuit inside a small body and requires various accessories for generating oil such as a drive motor, a hydraulic pump and a wheel cylinder. These accessories complicate the production process of the vehicle or the vehicle, increase the weight of the vehicle body, require frequent filling of the braking fluid, and damage the hydraulic tube due to external shocks, causing the braking fluid to leak. It also provided the cause of the failure.

The present invention is a breakthrough to solve the various problems at once, the sensor for sensing the brake signal of the brake pedal and the electronic control unit (ECU) receiving the brake signal from the sensor and driving the rotary member to rotate the wheel And a contact member which is in contact with the rotating member during braking to generate a braking force by friction, and a pressurizing device for pushing the contact member to the rotating member and a pressure source for providing a pressure source to generate the pressure. In a vehicle equipped with a driving unit,

The pressurization device includes a piezoelectric actuator for generating displacement by electricity, and the pressure generation drive unit includes a power supply device for generating a power and outputting a voltage. The piezoelectric actuator and the braking voltage control unit are connected to an electric transmission member. The present invention relates to a braking device for braking a moving object using a very simple configuration and control method.

 2 schematically shows a brake control circuit of the present invention configuration. As shown in FIG. 2, the present invention provides a pedal sensor for sensing a brake signal of a brake pedal; An electronic control unit (ECU) for receiving a braking signal from the sensor; A contact member (B) for driving a rotating member to rotate the wheels and being in close contact with the rotating member (C) to generate a braking force by friction during braking; A pressing device (A) for pushing the contact member to the rotating member; In a vehicle having a pressure generating drive unit for providing a pressure source to generate pressure in the pressurizing device,

The pressurizing device (A) is provided with a piezoelectric actuator for generating a displacement by the voltage and has a braking voltage control unit including a power supply for generating a power supply to the pressure generating drive unit for outputting the voltage, the piezoelectric actuator and the braking voltage The control unit is connected to a good conductor of electricity. In general, a piezoelectric element is a device using a piezoelectric effect that generates an electrical signal when there is a change in volume under pressure. However, the piezoelectric element used in the present invention, on the contrary, generates a change in volume along with vibration when an electric signal is received. Such piezoelectric elements are generally called piezoelectric actuators. 3 is a cross-sectional view showing a piezoelectric actuator. The piezoelectric element or piezoelectric actuator 10 is formed by laminating thin metals. As the metal used for the piezoelectric element 10, a lot of salts of roselle, barium titanate, and the like are used, and various response characteristics of the piezoelectric element as described above have a height of 10 mm in cross section of a stacked piezoelectric element 6 × 6 mm. In the case of 50㎛ thickness, when the voltage of 150V is applied, the displacement amount is 10㎛, the generating force is 980N, and the response speed is 10㎲ or less. The piezoelectric elements or piezoelectric actuators 10 are provided with + and − terminals, respectively, and voltage is applied thereto. The displacement generated at this time is proportional to the cross-sectional area of the piezoelectric element.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 4 to 6 are schematic diagrams of an embodiment of the present invention in a braking system of a vehicle.

Example 1 shows a braking device by means of a piezoelectric actuator used as a pressurizing device acting directly on a brake wheel in the case of a braking system of a vehicle. As shown in FIG. 4, one end of the piezoelectric actuator 10 is fixed to the caliper housing 60 of the brake. The other end, which is the displacement generating part of the piezoelectric actuator 10, is provided to be in close contact with the pad back plate 40 of the brake or to maintain a very small gap. In addition, a power input terminal is provided at the anodes (+,-) of the piezoelectric actuator 10 to be connected to the braking voltage control unit D with a good conductor of electricity. The braking operation and control method according to the configuration of Embodiment 1 receives a braking signal from the electronic control unit (ECU), sends a braking signal to the braking voltage control unit (D), and the braking voltage control unit (D) is suitable for the braking signal. The voltage is applied to the piezoelectric actuator 10. When a voltage is input from the braking voltage controller D, a fixed rigid body 20 is provided in the caliper housing 60 of the piezoelectric actuator 10, and one end 10b closely adhered to the fixed rigid body 20 is initially Displacement does not occur, and longitudinal displacement occurs at the other end 10a on the brake pad back plate 40 side. By this displacement, the piezoelectric actuator 10 pushes the brake pad back plate 40 and the pad 30 to the brake disc 50 side, and the brake pad back plate 40 which is in contact with the piezoelectric actuator 10. ) And the pad 30 compress the brake disc 50. The displacement generated at the other end 10a of the piezoelectric actuator 10 is primarily the piezoelectric actuator when the pad 30 is pressed against the disk 50 and is blocked by the disk to prevent the pad 30 from moving further. Since one end portion 10b of 10) is caused to be displaced by the repulsive force, the opposite pad 31 is also pressed onto the disk by pushing the housing 60 to friction braking.

Example 2 has the same configuration as in Example 1 above, and merely installs the displacement expanding mechanism 11 between the piezoelectric actuator 10 and the brake pad back plate 40. As shown in the displacement amount of the piezoelectric actuator 10 described above, the displacement amount of the piezoelectric actuator is extremely small. Therefore, in order to secure the displacement required when the piezoelectric actuator 10 pushes the brake pad 30 and compresses the disk 50, if the cross-sectional area of the piezoelectric actuator 10 is not sufficiently secured, the displacement It is preferable that the displacement enlargement mechanism 11 for enlarging is provided at the same time. The known displacement expanding mechanism 11 makes the lever mechanism by electric discharge machining on the metal member, and enlarges the displacement amount by constructing the piezoelectric actuator 10. In order to transfer the displacement amount of the piezoelectric actuator to the displacement expansion mechanism 11 without loss, it is necessary to add a preload of a predetermined load to the piezoelectric actuator 10 and configure it. 5 shows a known example of the displacement expanding mechanism. 6 is a cross-sectional view of the overall configuration of the second embodiment. As shown in Fig. 5, a preload spring 14 is formed in the displacement expanding mechanism 11, and a preload set bolt 13 is used to add a necessary preload. The characteristic of this displacement expanding mechanism 11 is that the mechanism has a symmetrical structure, and in the case of such a lateral symmetrical displacement expanding mechanism, a good straight displacement can be obtained. The displacement expanding mechanism 11 keeps the displacement output end 16 in close contact with the brake pad back plate 40 or maintains a very fine distance, and the other end, that is, the fixed end 15 is fixed to the caliper housing 60 of the brake. Install. In the braking operation and the control method according to the configuration of the second embodiment, the braking signal is input from the electronic control unit (ECU), and the braking signal is transmitted to the braking voltage control unit (D). Appropriate voltage is applied to the piezoelectric actuator 10. The piezoelectric actuator 10 has a longitudinal displacement according to the applied voltage, and the displacement is enlarged through the displacement expanding mechanism 11. The enlarged displacement pushes the pad back plate 40 and the pad 30 of the brake in contact with the displacement expanding mechanism 11, and the brake pad 30 compresses the rotating brake disc 50 so that braking is performed. do.

The embodiment of the present invention discloses only the case where it is applied to a braking device in a vehicle, but it is a matter of course that the present invention is applicable to all operating devices that can stop or decelerate a rotating rotating member by frictional contact. .

 As described in detail above, according to the configuration according to the present invention by implementing a braking system consisting of the existing braking device of the electric circuit only can greatly simplify the braking structure of the various braking device and can be reduced in size and light weight. Therefore, in accordance with the trend of miniaturization of various electronic and mechanical devices, it can be used very effectively for special purpose braking devices that require compact and lightweight as well as replacement of existing hydraulic and pneumatic braking devices. In addition, the piezoelectric actuator has a very good time response, so there is almost no time lag, so a rapid braking response can be expected.

Claims (4)

A sensor for sensing a brake signal of a brake pedal and a rotating member to drive a wheel to rotate the wheel, and a contact member that comes in close contact with the rotating member to generate a braking force by friction when braking, and pushes the contact member to the rotating member. And a pressure generating unit for providing a pressure source to generate pressure in the pressing device, and a braking signal from the sensor to control the contact member, the pressure device, and the pressure generating unit with electrical signals. In a vehicle provided with an electronic control unit (ECU), The pressurization device includes a piezoelectric actuator for generating displacement by electricity, and the pressure generation drive part includes a power supply device for generating power and outputting a voltage according to a braking signal input from the electronic control unit (ECU). And a braking voltage control unit including a control device for controlling a power supply device, wherein the piezoelectric actuator and the braking voltage control unit are connected to an electric transmission member. The braking signal of claim 1, wherein the electronic control unit (ECU) detects a braking signal input from the outside and outputs the braking voltage control unit to the braking voltage control unit, and the braking voltage control unit receives a braking signal to supply a voltage corresponding to the braking signal. The braking control method according to claim 1, wherein the piezoelectric actuator is driven to drive the piezoelectric actuator, and the contact member is pressed against the rotating member by the piezoelectric actuator to perform braking. The braking apparatus according to claim 1, further comprising a displacement expanding mechanism including the piezoelectric actuator as the pressing device. The braking signal of claim 2, wherein the electronic control unit (ECU) detects a braking signal input from the outside and outputs the braking voltage control unit to the braking voltage control unit, and the braking voltage control unit receives a braking signal to supply a voltage corresponding to the braking signal. It is applied to the piezoelectric actuator to drive the piezoelectric actuator, the displacement of the piezoelectric actuator is generated as a further enlarged displacement through the output end of the displacement expanding mechanism, the contact member to the rotating member by the output end of the displacement expanding mechanism The braking control method in a braking device, characterized in that the pressure is compressed.

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