KR101482269B1 - Electric Mechanical Brake System having electric parking brake function - Google Patents

Abstract

In the present invention, an EMB (Electro-mechanical Brake), which is an electric brake apparatus using an actuator driving force with a wheel disc braking force, is driven by an actuator 2 generating power under the control of the ECU 1 so that pads 16a, The first and second gears 6 and 7 having a back lash between the gears are moved in the axial direction while the NSL (Non-Self Locking) screw type braking spindle 8 is moved in the axial direction, And a SL (Self Locking) screw type parking spindle 11 that generates a rotational difference from the braking spindle 8 by a backlash when the actuator 2 is rotated by the power of the actuator 2, The parking brake can be implemented through the parking spindle 11 using the rotation difference with respect to the parking brake 8, so that a separate motor for maintaining the parking brake force or a caliper configuration for improving the vehicle mounting property (packaging layout) Possible features It is.

Parking, electric brake, backlash

Description

TECHNICAL FIELD [0001] The present invention relates to an electric brake system having a parking brake function,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric brake apparatus, and more particularly to an electric brake apparatus having a parking brake function.

Generally, a brake (brake system) is a braking device used for decelerating or stopping a traveling vehicle while maintaining a parking state.

These brakes are usually friction-type brakes that convert kinetic energy into heat energy by using frictional force and release it into the atmosphere, which causes the disc to rotate together with the wheel, Function.

However, since such a hydraulic brake is implemented in a manner that the pad is strongly urged toward the disk by using the hydraulic pressure during braking, the hydraulic brake is operated by the master cylinder which is operated through the booster for exercising the pedal operation force to generate the hydraulic pressure, A complicated configuration is required for various devices to control and assisting them, and the complexity of such a configuration and the reliability of the braking performance due to the use of the hydraulic pressure are limited to some extent.

As a result, EMB (Electro Mechanical Brake) which can simplify the structure that hydraulic brake does not have and enhance reliability of braking performance is used.

However, the EMB using the motor driving force as the disc braking force has the complicated structure of the overall mechanism by the application of the decelerator and the non-self locking type piston, and this complicated mechanism has various additional functions, The addition of the EPB (Electro Parking Brake) increases the size and weight of the EMB to a larger size compared to the hydraulic caliper, and the overall configuration is further complicated, There is a vulnerability to disadvantage.

In the case of applying the solenoid for EPB function to such an EMB, due to the characteristics of the non-self locking type piston applying the wheel disc braking force, It is necessary to construct a separate mechanical structure for maintaining the binding force by the load.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide an electronic parking brake (EPB) function, which is an electric parking function added to an electro mechanical brake (EMB) By using the back lash formed by the interlocking, it is possible to limit the movement of the non-self locking type piston falling from the pad when the parking brake is applied to the back lash of the reducer gear, ) Type braking force can be maintained by the piston, and the EPB function that does not use a separate motor or solenoid is realized, thereby increasing the size of the EMB and minimizing the increase in weight, while also being advantageous in terms of cost.

According to an aspect of the present invention, there is provided an electronic braking system comprising: an ECU for generating a control signal for braking together with measurement information on a vehicle running state when an electric brake apparatus senses a signal of an electronic pedal;

An actuator for generating power by the ECU control;

A braking spindle for moving the inner and outer pads toward the wheel disc when the actuator is driven to generate axial movement for implementing the braking state;

A decelerator rotated through a braking spindle rotated through the actuator;

A parking spindle operated through the speed reducer to generate a parking braking force so that the parking spindle is operated with an interval to the operation of the brake spindle;

A caliper having an inner / outer pad for pressurizing the wheel disc;

.

To this end, the actuator comprises a stator and a rotor positioned in the inner space of the stator via a bearing to transmit rotational force to the braking spindle.

The speed reducer includes a first gear rotated together with a brake spindle receiving rotational power of the actuator and a second gear engaged with the first gear to have a back lash to rotate the parking spindle .

The braking spindle includes a screw shaft to which a first gear having a backlash and a second gear that rotates under the rotation of the actuator are fixed and a second gear that forms a speed reducer and an inner pad which is moved toward the wheel disc according to the rotation direction of the screw shaft. And the piston nut is moved in the axial direction so that the screw shaft and the piston nut are separated from each other. The screw shaft and the piston nut have a non - self locking (NSL) screw structure.

The parking spindle includes a parking screw shaft which is fixed to a second gear engaged with a back lash on a first gear that forms a speed reducer and an inner pad which is rotated toward the wheel disc along a rotating direction of the parking screw shaft And a parking piston nut which is moved in an axial direction so as to move and fall. The parking screw shaft and the parking piston nut have an SL (Self Locking) screw structure.

According to the present invention, when the EMB (Electro-Mechanical Brake) that uses the actuator driving force by the disc braking force limits the movement of the non-self locking (NSL) screw type piston falling from the pad to the back lash of the gear reducer during parking braking , EPB function without separate motors or solenoids, it is possible to minimize the increase of the EMB size and the weight, and it is advantageous in terms of cost with a simpler mechanical structure.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which illustrate exemplary embodiments of the present invention. The present invention is not limited to these embodiments.

1 is a block diagram of an electric braking device having a parking braking function according to the present invention. The electro brake (EMB) of the present invention grasps the driving state of the vehicle, And an actuator 2 for generating power under the control of the ECU 1. The actuator 2 drives the pads 16a and 16b through the power of the actuator 2, And a braking spindle (8) for moving the braking spindle (D) to generate an axial movement for generating a braking force.

In addition, the EMB further includes a speed reducer 5, which is rotated together with the actuator 2, and is composed of a pair of first and second gears 6 and 7 coupled to each other so as to have a back lash, And a parking spindle 11 which is operated through the speed reducer 5 to generate a parking braking force.

To this end, the ECU 1 receives vehicle position information via a yaw moment sensor mounted on the vehicle in addition to the input amount information of the operated electronic pedal, and implements the control required in braking.

The actuator 2 includes a stator 3 controlled by the ECU 1 and a rotor 4 positioned in the inner space of the stator 3 via bearings to transmit a rotational force to the braking spindle 8 ), And if necessary, it is covered with a boot to prevent the outside from entering the inside of the material.

The speed reducer 5 includes a first gear 6 rotated together with a braking spindle 8 receiving a rotational power of the actuator 2 and a second gear 6 having a back lash in the first gear 6, And a second gear (7) which rotates the parking spindle (11).

The sizes of the back lashes B formed between the gears 6a and 7a of the first and second gears 6 and 7 are set such that the braking spindle 8 The inner pads 16a are first moved toward the wheel disc D and the brake spindle 8 is rotated before the parking spindle 11 is rotated during parking braking to move the inner pad 16a to the wheel disc D, (D).

The braking spindle 8 is rotated by the rotational power of the actuator 2 and is rotated by the screw shaft 9 to which the first gear 6 is fixed, And a piston nut (10) which is moved in the axial direction so as to move the wheel (16a) toward and away from the wheel disc (D).

To this end, a ball or roller type screw is applied between the screw shaft 9 and the piston nut 10 to form a non-self locking (NSL) screw type that minimizes frictional force during rotation and axial movement. do.

The parking spindle 11 includes a parking screw shaft 12 rotatably fixed to a second gear 7 meshed with a back lash on the first gear 6, And a parking piston nut (13) moved in the axial direction so as to move the inner pad (16a) toward the wheel disk (D) in accordance with the rotation direction of the wheel (12).

The parking spindle 11 has a self-locking (SL) screw type so that the parking brake force can be maintained when the power is off.

The EMB of the present invention is mounted on a caliper 14 having inner and outer pads 16a and 16b for pressing the wheel disk D. The caliper 14 is driven by the actuator 2 And has a conventional structure in which, when braking and subject braking are performed, the torque is transmitted through the torque member to move the floating side portion toward the wheel disk D side.

The inner pad 16a is moved toward the wheel disk D via the back plate 15, that is, when the force applied by the brake spindle 8 and the parking spindle 11 is applied to the back plate 15, The inner pad 16a is moved toward the wheel disk D through the back plate 15. [

As described above, according to the present invention, an EMB (Electro Mechanical Brake), which is an electric braking device using an actuator driving force with a wheel disc braking force, is driven by an actuator 2 generating power under the control of the ECU 1, (Non-self locking) screw type braking spindle 8 for moving the braking spindle 8 toward the wheel disc D is moved in the axial direction and the first and second gears 6 and 7 having a back lash between gears And a SL (Self Locking) screw type parking spindle 11 which generates a rotational difference from the brake spindle 8 by a backlash when the actuator 2 is rotated by the power of the actuator 2, The parking brake can be implemented through the parking spindle 11 using the rotation difference with respect to the braking spindle 8 so that no separate motor or solenoid for maintaining the parking braking force is used, Caliper configuration possible Thereby characterized.

1, the EMB (Electro Mechanical Brake) is controlled by the ECU 1 to generate power by the actuator 2, and the brake spindle 8 is driven by the power of the actuator 2 A back lash B is applied to the first gear 6 fixed to the brake spindle 8 so as to generate axial movement to move the inner and outer pads 16a and 16b toward the wheel disc D And the parking spindle 11 fixed to the second gear 7 meshed so as to hold the parking braking force when the power is off.

2, when the ECU 1 recognizing the braking state drives the actuator 2, the braking operation of the braking spindle (not shown) is performed through the rotor 4 constituting the actuator 2, The NSN screw type coupled piston nut 10 is pulled out of the screw shaft 9 to the screw shaft 9 as the screw shaft 9 of the piston nut 8 is rotated, The movement pushes the back plate 15 to act to move the inner pad 16a toward the wheel disk D. [

When the inner pad 16a is moved toward the wheel disk D by the action of the screw shaft 9 and the piston nut 10, the outer pad 16b is also rotated by the torque member interlocking action of the caliper 14, D) to implement the braking action.

The operation of the brake spindle 8 rotates the speed reducer 5 but the parking spindle 11 that implements parking braking causes the first gear 6 and the second gear 7 constituting the speed reducer 5 So that the operation of the braking spindle 8 is not affected.

That is, even if the first gear 6 rotates together with the screw shaft 9, the first gear 6 meshes with the first gear 6, As the second gear 7 is rotated after the gear 6 is rotated, the braking spindle 8 is rotated earlier than the rotation of the parking spindle 11. [

Due to the difference in rotation between the braking spindle 8 and the parking spindle 11, the piston nut 10 rotating through the screw shaft 9 of the braking spindle 8 rotates before the parking spindle 11 is operated The back plate 15 can be pushed first.

The gap A is formed between the parking spindle 11 and the back plate 15 even if the first and second gears 6 are continuously rotated and the parking spindle 11 is actuated to move the braking spindle 8 in the axial direction The inner pad 16a presses the wheel disc D to generate the braking force.

3 (A) and 3 (B), the ECU 1 causes the actuator 2 to rotate in the reverse direction, while the first gear 6 is rotated in the reverse direction And the brake spindle 8 comes off from the wheel disk D.

The first gear 6 is first reversely rotated before the meshed second gear 7 is rotated with the back lash interval B so that the inner pad 16a is rotated in the reverse direction D, the back plate 15, which is spaced apart from the gap A, is brought into contact with the parking spindle 11.

When the second gear 7 from which the backlash is removed from the first gear 6 is continuously rotated in the state that the parking spindle 11 is in contact with the back plate 15, The parking piston nut 13 is disengaged in accordance with the rotation of the parking screw shaft 12.

The axial movement of the parking piston nut 13 due to the removal of the parking piston nut 13 pushes the back plate 15 and moves the inner pad 16a together with the back plate 15 toward the wheel disk D to generate a parking brake force .

When the actuator 2 is turned off in the parking braking state as described above, the parking spindle 11 maintains the parking braking force. This is because the parking spindle 12 constituting the parking spindle 11 and the parking- The locking force between the parking screw shaft 12 and the parking piston nut 13 is maintained even if the parking screw shaft 12 is not rotated because the locking screw shaft 13 is made of a SL (Self Locking) screw type.

1 is a block diagram of an electric braking apparatus having a parking braking function according to the present invention

Fig. 2 is a braking operation diagram of the electric braking device according to the present invention. Fig.

Figs. 3 (a) and 3 (b) are a braking operation diagram of the electric braking device according to the present invention

    Description of the Related Art

1: ECU 2: Actuator

3: stator 4: rotor

5: Reduction gear 6, 7: 1st and 2nd gears

6a, 7a: gear

8: Brake spindle 9: Screw shaft

10: Piston nut 11: Parking spindle

12: Parking screw shaft 13: Parking piston nut

14: caliper body 15: back plate

16a and 16b: inner and outer pads

Claims (8)

An ECU (1) for generating a control signal for braking together with measurement information on a vehicle running state when detecting a signal of an electronic pedal; An actuator (2) for generating power under the control of the ECU (1); A screw shaft 9 rotating in response to the rotational power of the actuator 2 and an inner pad 16a moving toward the wheel disk D in a direction of rotation of the screw shaft 9, A braking spindle 8 constituted by a piston nut 10 to be moved; A first gear 6 rotatable together with the braking spindle 8 which receives rotational power of the actuator 2 and a second gear 6 meshed with a back lash on the first gear 6, And a second gear (7) for rotating the first gear (11); A parking spindle (11) operated through the speed reducer (5) to generate a parking braking force so as to be operated with the gap of the backlash against the operation of the brake spindle (8); A caliper 14 having inner and outer pads 16a and 16b for pressurizing the wheel disc D; And a parking braking function. The actuator (2) according to claim 1, characterized in that the actuator (2) comprises a stator (3) and a rotor (4) positioned in the inner space of the stator (3) via bearings to transmit a rotational force to the braking spindle The electric braking device is equipped with a parking braking function. delete delete The electric braking device according to claim 1, wherein the screw shaft (9) and the piston nut (10) are non - self locking (NSL) screw type. The parking spindle according to claim 1, wherein the parking spindle (11) is fixed to a first gear (6) constituting a speed reducer (5) and fixed to a second gear (7) having a back lash And a parking piston nut 13 which is moved in the axial direction so as to move the inner pad 16a toward and away from the wheel disk D in accordance with the rotation direction of the parking screw shaft 12. [ Electric braking device with parking brake function. 7. The electric brake apparatus according to claim 6, wherein the parking screw shaft (12) and the parking piston nut (13) are SL (Self Locking) screw type. The electric braking device according to claim 1, wherein the inner pad (16a) receives a force applied by the braking spindle (8) and the parking spindle (11) via a back plate (15).

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