JP2003014014A - Electric brake device - Google Patents

Abstract

(57) [Problem] To provide an electric brake device capable of easily releasing a brake without relying on a special assembling member. SOLUTION: A caliper 2 having a piston 11, a motor 12, and a ball ramp mechanism 13 for converting the rotation of the motor into a linear motion and transmitting the linear motion to the piston 11 is supported by the carrier 1 in a floating manner. The piston 11 is propelled to press one brake pad 4 against one surface of the disk rotor D, and the claw 5 of the caliper 2 is
In the electric brake device which generates a braking force by pressing the other brake pad 3 against the other surface of the disk rotor D by a, a screw hole 45 is provided in the claw portion 5a of the caliper 2 so that the brake is activated by the failure of the motor 12. When locked, the screw member 46 is screwed into the screw hole 45 to press the other brake pad 3, and the reaction
To reverse to release the brake.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric brake device for generating a braking force by a torque of a motor, and more particularly to an electric brake device provided with a brake release mechanism for forcibly releasing a brake.

[0002]

2. Description of the Related Art As an electric brake device, a caliper having a piston, a motor, and a rotation-linear motion converting mechanism for converting a rotation of the motor into a linear motion and transmitting the linear motion to the piston is provided in a vehicle. A carrier fixed to a rotating unit is supported so as to be floatable, and the piston is propelled in response to the rotation of the motor to press one of a pair of brake pads supported by the carrier against one surface of the disc rotor. There is a method in which the other side of the brake pad is pressed against the other surface of the disc rotor by the claw portion of the caliper by utilizing the reaction to generate a braking force.

In such an electric brake device,
If the piston becomes uncontrollable due to a motor failure or the like during braking when thrust is generated in the piston, the reverse operability of the rotation-to-linear motion conversion mechanism is low, so thrust remains in the piston and the brake remains locked. Become. Therefore, conventionally, for example, in the one disclosed in Japanese Patent Laid-Open No. 2000-74110,
A wedge-shaped member is arranged on the back surface side of the claw portion of the caliper, and the wedge-shaped member is wedge-fixed to the back surface of the claw portion by a bolt that passes through the claw portion. Measures are taken to change the position and release the brake.

[0004]

However, according to the brake release mechanism provided with the wedge-shaped member, it is extremely difficult to change the position of the wedge-shaped member when a high thrust is generated in the piston, and it takes a long time to release the brake. There was a problem that it took time. In addition, since the wedge-shaped member must be separately prepared and assembled to the caliper, there is a problem that an increase in manufacturing cost due to an increase in the number of assembling steps cannot be avoided. The present invention has been made in view of the above technical background, and an object thereof is to provide an electric brake device capable of easily releasing a brake without relying on a special assembly member. It is in.

[0005]

In order to solve the above-mentioned problems, the present invention provides a piston, a motor and a rotation-linear motion conversion mechanism for converting the rotation of the motor into a linear motion and transmitting the linear motion to the piston. The installed caliper is floatably supported by a carrier fixed to a non-rotating portion of the vehicle, and the piston is propelled in accordance with the rotation of the motor, so that one of a pair of brake pads supported by the carrier is a disc. While pressing against one surface of the rotor, using the reaction of the other part of the brake pad by the claw part of the caliper to press the other surface of the disc rotor to generate a braking force, in the claw part of the caliper, A through hole for inserting an operation member that applies a pressing force to the disc rotor side to the other brake pad is provided. In the electric brake device configured as described above, when the brake is locked due to a motor failure or the like, the operating member is inserted through the through hole provided in the claw portion of the caliper, and the pressing force is applied to the brake pad facing the claw portion. When added, the reaction causes the piston to retract and the thrust of the piston to decrease. The present invention can be configured such that the through hole provided in the claw portion is a screw hole, and a screw member as an operating member is screwed into the screw hole. In this case, the screw member is simply screwed. Then, you can easily release the brake. The present invention can also be configured such that a key-like protrusion is integrally provided on the front side of the claw portion, and an operation member is provided in an operation tool that can be rotated around the key-like protrusion as a fulcrum. The brake can be released with one touch simply by hooking the tip of the tool on the key-like protrusion and rotating it.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an electric brake device according to a first embodiment of the present invention. In the figure, 1 is a carrier fixed to a non-rotating portion (knuckle or the like) of the vehicle located inside the vehicle from the disc rotor D, 2
Is a caliper supported on the carrier 1 so as to be floatable in the axial direction of the disc rotor D. Reference numerals 3 and 4 are a pair of brake pads arranged on both sides of the disc rotor D. The brake pads 3 and 4 are the disc rotor D. Is supported by the carrier 1 so as to be movable in the axial direction. The caliper 2 includes a claw member 5 having a claw portion 5a on the tip side, and an annular base 6 connected to the base end side of the claw member 5 by a bolt (not shown).
The base 6 is provided with an assembly type caliper body 10 including a ring-shaped support plate 8 and a motor case 9 which are joined together by bolts 7, and the claw portion 5a of the claw member 5 of the brake pad 3 outside the vehicle. It is located close to the back.

The caliper 2 also includes a piston 11 which can come into contact with the back surface of a brake pad 4 inside the vehicle, and a motor 12.
And a ball ramp mechanism (rotation-linear motion conversion mechanism) 13 for converting the rotation of the motor 12 into a linear motion and transmitting it to the piston 11, and a differential for decelerating the rotation of the motor 12 and transmitting it to the ball ramp mechanism 13. And a speed reduction mechanism 14.

The piston 11 has a large-diameter body portion 15 and a small-diameter shaft portion 16 which are connected to each other.
5 is arranged close to the brake pad 4 inside the vehicle. The shaft portion 16 of the piston 11 is provided with a shaft hole 16a, and the piston 11 has a rod 18 extending from the end plate 17 of the motor case 9 inserted into the shaft hole 16a. 18 is slidably and non-rotatably supported. A rubber cover 1 for closing the inside of the caliper body 10 from the outside is provided between the body portion 15 of the piston 11 and the claw member 5 of the caliper body 10.
9 is stretched.

The motor 12 comprises a stator 20 fitted and fixed to the motor case 9 and a hollow rotor 21 arranged in the stator 20. The rotor 21 has a bearing 22 on the motor case 9 and the support plate 8. , 23 rotatably supported. The motor 12 operates so as to rotate the rotor 21 by a desired torque and a desired angle in response to a command from a controller (not shown). The rotation angle of the rotor 21 is the resolver rotor 24 fixed to the rotor 21 and the motor case 9. The rotation detector 26 is composed of a resolver stator 25 fixed to the end plate 17 and is detected. The motor case 9 has a motor 12
A signal line 27 connecting the stator 20, the rotation detector 26 and the controller is routed.

The ball ramp mechanism 13 as a rotation-linear motion conversion mechanism includes a ring-shaped first disk 31 rotatably supported on the inner peripheral portion of the annular base body 6 of the caliper body 10 via a cross roller bearing 30. The ring-shaped second disc 32 screwed to the shaft portion 16 of the piston 10 and both discs 31
And a ball 33 interposed between and.

The balls 33 are loaded on the facing surfaces of the first disk 31 and the second disk 32 between three ball grooves 34 and 35 formed in an arc shape along the circumferential direction, respectively. There is. The ball grooves 34 and 35 are respectively inclined in the same direction and are arranged at equal intervals in the range of an equal center angle (for example, 90 °). When rotating clockwise when viewed from the right side of 2, the second disk 32 moves forward (moves linearly) to the left in the figure. At this time, there is a considerable resistance in the threaded portion between the second disc 32 and the shaft portion 16 of the piston 11, which causes the second disc 32 to move forward without rotating, and the piston 11 accordingly moves. Advance (promotion)
Then, the brake pad 4 inside the vehicle is pressed against the disc rotor D.

On the other hand, the piston 11 of the second disk 32
An extension cylinder portion 36 that greatly extends toward the end plate 17 side of the motor case 9 is continuously provided at a portion screwed to the shaft portion 16 of the rod case. One end of the rod 18 is provided in the extension cylinder portion 36. A disc spring 37 is provided which is locked and normally urges the second disc 32 toward the first disc 31 via the extension tube portion 36. As a result, the ball 33 of the ball ramp mechanism 13 is strongly pressed between the two disks 31 and 32,
When the first disc 31 rotates counterclockwise with respect to the second disc 32 when viewed from the right in FIG. 2, the second disc 32 retracts to the right in the diagram and the piston 11 moves from the brake pad 4 to the right. It comes to separate. A limiter mechanism 38 that causes the piston 11 to follow the wear of the brake pad 4 is disposed around the extension cylinder portion 36 of the second disc 32.

The differential reduction mechanism 14 is an eccentric shaft 40 formed at an extension end of the rotor 21 of the motor 12 toward the disk rotor D side, and is rotatably fitted to the eccentric shaft 40 via a bearing 41. An eccentric plate 42, an Oldham mechanism 43 interposed between the eccentric plate 42 and the support plate 8 of the caliper main body 10, and between the eccentric plate 42 and the first disc 31 of the ball ramp mechanism 13. The cycloidal ball reduction mechanism 44 is mounted. The eccentric plate 42 revolves in response to the rotation of the eccentric shaft 40 without rotating due to the operation of the Oldham mechanism 43, while the cycloidal ball reduction mechanism 44 operates in response to the revolution motion of the eccentric plate 42. The first disk 31 of the ball ramp mechanism 13 rotates with the rotor 21 at a constant rotation ratio. Note that FIG.
Where O ₁ is the center of rotation of the rotor 21, and O ₂ is the eccentric shaft 40.
, Δ indicates the eccentric amount of both.

A screw hole (through hole) 45 is provided in the claw portion 5a of the claw member 5 constituting the caliper body 10. The screw hole 45 is formed substantially concentric with the rotation center O _{1 of the} rotor 21, that is, the axial center of the piston 11, and is provided with a screw member (operating member) when brake release described later becomes necessary. ) 46 is screwed.

The operation of the electric brake device configured as described above will be described below. At the time of braking (at the time of braking), the motor 12 is operated by a command from a controller (not shown).
When the rotor 21 of is rotated clockwise with a predetermined torque,
The eccentric shaft 40 rotates integrally with this, and the eccentric plate 42 revolves by the Oldham mechanism 43 without rotating. Then, by the revolution movement of the eccentric plate 42, the cycloid ball reduction mechanism 44 operates, and the first disk 31 of the ball ramp mechanism 13 rotates with the rotor 21 at a constant rotation ratio. On the other hand, since the rotation of the second disc 32 is restricted by the resistance of the screwing portion of the piston 11 with respect to the shaft portion 16, the second disc 32 moves forward in accordance with the rotation of the first disc 31.

At this time, the cycloid ball reduction mechanism
Reference circle of the cycloid groove on the eccentric plate 42 side at 44
The diameter of d is the base of the cycloid groove on the side of the first disc 31.
If the diameter of the quasi-circle is D, the first part of the ball ramp mechanism 13
The disk 31 has a constant rotation ratio N {= (D-
Rotate with d) / D}. In this case, the first disc
The rotation speed of the rotor 21 when 31 makes one rotation is equal to the reduction ratio α
(= 1 / N). Then, when the rotor 21 has a certain angle θ
The rotation angle θ of the first disk 21 _AIs θ /
α, and the ball grooves 34, 35 of the ball ramp mechanism 13
When the inclination (lead) of the second disk 32 is L
The vehicle moves forward by {= (L / 360) × (θ / α)}.

Then, the second of the ball ramp mechanism 13
As a result of the disc 32 moving forward, the piston 11 propels the brake pad 4 inside the vehicle against the disc rotor D, and the reaction force causes the caliper 2 to move with respect to the carrier 1 and the pawl portion of the pawl member 5. 5a presses the brake pad 3 outside the vehicle against the outside surface of the disc rotor D,
As a result, a braking force corresponding to the torque of the motor 12 is generated. On the other hand, when the rotor 21 of the motor 12 is reversely rotated from this braking state, the second disc 32 and the piston 11 are integrally retracted by the urging force of the disc spring 37, and the pressing force to the disc rotor D is released, and the brake is applied. Is released.

If the motor 12 breaks down during braking and the piston 11 becomes uncontrollable, the ball ramp mechanism 13 and the differential reduction mechanism 14 act as resistance and thrust remains on the piston 11 to lock the brake. It will remain. In such a case, a separately prepared screw member 46 is screwed into the screw hole 45 of the claw portion 5a. Then, the tip end of the screw member 46 comes into contact with the back surface (back plate) of the brake pad 3 outside the vehicle, and a pressing force to the disc rotor D side acts on the brake pad 3 in accordance with the screwing of the screw member 46. . Then, the reaction causes the piston 1
When a force in the backward direction is applied to 1 and the force exceeds the friction required for the backward movement of the piston 11, the piston 11 starts to move backward. Then, when the screw member 46 is loosened when the piston 11 retracts to some extent, the disc rotor D
The pressing force of the brake pad 3 with respect to is released, the brake pad 3 is brought into a state of slightly contacting or slightly separated from the disc rotor D, and the brake is released.
Therefore, after that, the vehicle can be moved to a safe place by using the remaining normal braking system.

In the first embodiment, only the screw hole 45 is formed in the claw portion 5a of the claw member 5 which constitutes the caliper main body 10. Therefore, in order to release the brake, a special part such as a wedge-shaped member is formed. It is not necessary to assemble the components to the caliper 2, and the manufacturing cost can be reduced by reducing the number of parts and the number of assembling steps. Further, the claw portion 5a of the claw member 5
Since it is not necessary to provide a wedge mating surface, the conventional thickness is sufficient and the caliper main body 10 does not become large. In the first embodiment, since the rotation of the rotor 21 of the motor 12 is sufficiently reduced by the differential reduction mechanism 14, the torque required for the motor 12 can be reduced as much as possible. Therefore, the motor 12 can be downsized, and the caliper body 10 can be downsized.

FIG. 2 shows an electric brake device according to a second embodiment of the present invention. Since the overall configuration and operation of the present electric brake device are the same as those of the first embodiment described above, the same parts as those shown in FIG. It will be omitted. In the second embodiment, the claw portion 5a of the claw member 5 that constitutes the caliper body 10 is used.
In place of the screw hole 45 in the first embodiment, a simple through hole 50 is provided, while a key-like protrusion 51 is provided on the upper side of the claw portion 5a of the claw member 5 on the front side. A plate-shaped operation tool 53 having an operation member 52 that can be inserted into the through hole 50 is prepared. The tip of the operation tool 53 is
The operation tool 53 has a taper-shaped portion that gradually reduces the plate thickness, and the operation tool 53 has an engaging claw 53 provided at the tip of the taper-shaped portion.
By engaging a with the key-like protrusion 51, the key-like protrusion 51 can swing about the fulcrum. Then, the operation member 42 moves the operation tool 53 around the key-like protrusion 51 as a fulcrum,
It is provided at a position just entering the through hole 50 of the claw portion 5a when rotated in the direction of the arrow F, that is, in the direction approaching the claw portion 5a.

According to the second embodiment, when the motor 12 breaks down during braking and the piston 11 becomes uncontrollable, the operating tool 53 has a key-like engagement pawl 53a. The protrusion 51 is engaged and rotated in the direction of arrow F. As a result, the operating member 52 provided on the operating tool 53 causes the claw portion 5a to move.
Brake pad 3 on the outside of the vehicle
Abut the back of. Therefore, when the operation tool 53 is further rotated in the direction of arrow F from this state, the key-like protrusion 5
1 serves as a fulcrum and the tip of the operating member 52 serves as a point of action, the operating tool 53 functions like a lever, and a pressing force to the disc rotor D side acts on the brake pad 3. Then, as in the case of the first embodiment, the reaction causes a backward force to be applied to the piston 11, and the piston 11 starts to retract.
Then, when the piston 11 retracts to some extent, the operating tool 53 is rotated in the direction opposite to the arrow F direction, that is, in the return direction, the pressing force of the brake pad 3 on the disc rotor D is released, and the brake pad 3 is released. The brake is released when it comes into light contact with D or is slightly separated. In the second embodiment, the brake can be released with one touch simply by hooking the engaging claw 53a at the tip of the operation tool 53 on the key-like projection 51 and rotating the brake, and the brake can be released in a shorter time. Can be run with.

In the above two embodiments,
The ball ramp mechanism 1 as a rotation-linear motion conversion mechanism that converts the rotation of the motor 12 into a linear motion and transmits it to the piston 11.
Although 3 is used, it goes without saying that a ball screw mechanism may be used as the rotation-linear motion converting mechanism.

[0024]

As described in detail above, according to the electric brake device of the present invention, the brake can be easily released by using the through hole provided in the claw portion of the caliper, and the special brake is used. Since the attaching member is not necessary, the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a structure of an electric brake device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a structure of an electric brake device according to a second embodiment of the present invention.

[Explanation of symbols]

1 career 2 calipers 3, 4 brake pads 5 claw members 5a Claw D disk rotor 10 Caliper body 11 pistons 12 motors 13 Ball ramp mechanism (rotation-linear motion conversion mechanism) 14 Differential reduction mechanism 45 Screw hole (through hole) on the claw 46 Screw member (operation member) 50 Through hole in the claw 51 key projection 52 Operation member 53 Operation tool

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3J058 AA43 AA48 AA53 AA63 AA78                       AA87 BA17 BA62 BA80 CC15                       CC26 CC56 CC76 FA01 FA11                       FA21

Claims (3)

[Claims] 1. A caliper having a piston, a motor, and a rotation-linear motion conversion mechanism for converting the rotation of the motor into a linear motion and transmitting the linear motion to the piston is fixed to a non-rotating portion of a vehicle. The carrier is supported so as to be floatable, and the piston is propelled according to the rotation of the motor to press one of the pair of brake pads supported by the carrier against one side surface of the disc rotor, and by utilizing the reaction thereof. In an electric brake device in which the other side of the brake pad is pressed against the other side surface of the disc rotor by the claw portion of the caliper to generate a braking force, the claw portion of the caliper pushes the other brake pad toward the disc rotor side. An electric brake device having a through hole for inserting an operation member for applying pressure. 2. The electric brake device according to claim 1, wherein the through hole provided in the claw portion is a screw hole, and a screw member as an operating member is screwed into the screw hole. 3. A key-like projection is integrally provided on the front side of the claw portion, and an operating tool is provided with an operating tool rotatable about the key-like projection as a fulcrum. Electric brake device.