JP2003343620A - Electric disc brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable easy release of a clamp force by simple operation, such as hand operation, without using an electric power, when fastening occurs to an electric motor, a reduction gear mechanism, and an advancing and reversing mechanism in a state of pressing a friction pad against a disc rotor, and to easily form the clamp releasing means through simple constitution. <P>SOLUTION: A reduction gear mechanism 17 to decelerate the drive force of the electric motor 15 and transmit it to the advancing and reversing mechanism consists of: a planetary arm 18 rotated by the electric motor 15; a planetary gear 23 rotatably axially supported at the planetary arm 18; and a solar gear 26 to rotate the planetary gear 23 non-rotatably fixed by a fixing member 28. As a means for releasing the clamp when the fastening occurs in the electric motor 15, the reduction gear mechanism 17, and the advancing reversing mechanism, fixing by the fixing member 28 of the solar gear 26 is released, the solar gear 26 is changed into a rotatable state, and by manually operating the reduction gear mechanism 17, the advancing and reversing mechanism is operated, and pressing of the disc rotor 1 by friction pads 3 and 4 is released. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mounted on various vehicles such as automobiles and motorcycles, in which a forward / backward movement mechanism is moved forward / backward by a driving force of an electric motor, and a friction pad is pressed and slid on a disk rotor for braking. It is related to the electric disc brake that is performed, and when the friction pad is pressed against the disc rotor, if the electric motor, the reduction gear mechanism, the advancing / retreating mechanism, etc. are stuck, the clamping force of the friction pad Can be manually released easily and the braking is released.

[0002]

2. Description of the Related Art Conventionally, in various vehicles such as automobiles and motorcycles, an advancing / retreating mechanism operated by a driving force of an electric motor presses a friction pad against a disk rotor through a pressing member to perform braking. There is an electric disc brake that does. When this electric disc brake is activated, if the friction pad is pressed against the disc rotor and sticking occurs in the electric motor, the forward / backward movement mechanism, or the like, the braking release operation may not be performed. As a means for releasing the clamping force in such a case, in the conventional invention described in Japanese Patent Publication No. 2001-506348, a permanent magnet brake that operates with electric power from a power source different from the electric motor is provided.

In this prior art, as a brake actuating mechanism, a threaded roller transmission device is actuated by an electric motor to push and slide the friction pad against the disk rotor. The permanent magnet type brake has a support portion including a disk-shaped flange hub that supports a nut of a threaded roller transmission device and a spindle fitted to the flange hub via a pin, and the support portion. It is composed of a permanent magnet that is fixed so that it cannot rotate, and an electromagnet that has a magnetic field that opposes the magnetic field of this permanent magnet.

In the above permanent magnet type brake, the electromagnet is normally in the off state, and the support portion is fixed to the main body cover by the permanent magnet so that the support portion cannot rotate and slide, and is moved toward the support portion by the reaction force from the friction pad. It supports the biased nut. When the electric motor or the threaded roller transmission device becomes stuck and the braking cannot be released, the electromagnet is opposed to the magnetic field of the permanent magnet by energization from a power source different from that of the electric motor. The magnetic field of the permanent magnet is canceled by generating the magnetic field that generates, and the permanent magnet type brake is released. With this release, the support portion that supports the nut can be rotated, and the support portion can be retracted in the direction opposite to the friction pad. By this retraction, the entire threaded roller transmission device also retracts in the same direction, and the friction pad separates from the disk rotor, so that the clamping force can be released.

[0005]

However, in the above-mentioned means for releasing the clamping force by the electric power, when the electric power cannot be supplied due to the voltage drop or the line trouble, the releasing operation of the permanent magnet type brake cannot be performed, and the clamp I could not release my power. Further, the structure of the magnet type brake is complicated, the number of parts is large, and the assembling property and the maintainability may be deteriorated.

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and when the friction pad is pressed against the disc rotor, the electric motor, the reduction gear mechanism, the advancing / retreating mechanism, and the like are fixed to each other. If the electric disc brake malfunctions, you can manually operate the advancing / retreating mechanism without using electric power, etc., so that the pressing force on the friction pad can be released. It is a means of opening. Further, the means for releasing the clamping force can be easily formed with a simple structure without requiring complicated parts and a large number of assembling steps to improve productivity and maintainability.

[0007]

In order to solve the above-mentioned problems, the present invention provides an advancing / retreating mechanism for advancing / retreating by a driving force of an electric motor to generate a pressing force on a pressing member of a friction pad, and this advancing / retreating mechanism. A reduction gear mechanism for reducing and transmitting the driving force of the electric motor is provided on the caliper body, and an electric disk brake for braking by sliding the friction pad against the disk rotor by the advancing / retreating mechanism. The reduction gear mechanism is a planetary arm rotatable by an electric motor, a planetary gear rotatably supported on the outer periphery of the planetary arm, and a caliper body that is non-rotatably fixed by a fixing member. The sun gear that rotates the sun gear is fixed, and when the friction pad is pressed against the disc rotor, if the electric motor, the reduction gear mechanism, and the advancing / retreating mechanism become stuck, the sun gear is fixed. By releasing the fixing by the material and making the sun gear rotatable, the advancing / retreating mechanism is manually operated through the reduction gear mechanism, and the pressing member of the friction pad is forcibly returned to the inoperative state. It serves as a means for releasing the clamping force.

Further, the fixing member is engaged with the sun gear by the pressing plate and is urged toward the pressing plate by the urging means having an urging force smaller than the engaging force, so that the fixing member moves the fixing member to the sun gear. When the sun gear is engaged and fixed so that it cannot rotate, and when the clamping force is released, the fixing member is disengaged by the pressing plate, and the fixing member is disengaged from the sun gear by the urging force of the urging means. It is also possible to release the fixing of the gear and make the sun gear rotatable.

Further, the sun gear is provided with a circumferential groove concentric with the sun gear on the side of the pressing plate, and a small-diameter tip of a fixing member circumferentially arranged in the circumferential groove at a constant interval. Part is loosely slidable relative to each other, and fixing holes for inserting large-diameter insertion parts of the fixing member are provided in the circumferential groove at regular intervals. The sun gear is fixed so that it cannot be rotated by inserting the diameter insertion part into the fixing hole, and when the clamping force is released, the engagement of the fixing member by the pressing plate is released to fix the large diameter insertion part of the fixing member. It is also possible to release the fixing of the sun gear by detaching it from the fixing hole, and to rotate the sun gear while relatively sliding the small-diameter tip of the fixing member in the circumferential groove.

Further, the advancing / retreating mechanism has a ball screw nut which has a diameter larger than that of the planetary gear of the reduction gear mechanism and is rotated by the rotation of the planetary gear, and by the rotation of the ball screw nut,
It consists of a ball screw shaft that moves back and forth in the direction of the disk shaft.By rotating a large diameter ball screw nut with a planetary gear, the rotational force transmitted from the reduction gear mechanism is further reduced, and the ball screw shaft A pressing force may be generated on the pressing member via the.

[0011]

The present invention is configured as described above, and the sun gear of the reduction gear mechanism is non-rotatably fixed to the caliper body by the fixing member during normal operation of the electric disc brake. Therefore, when the brake pedal is depressed to perform the braking operation and the electric motor is driven to rotate the planetary arm, the planetary gear rotatably supported by the planetary arm rotates around the outer periphery of the non-rotatably fixed sun gear. Move. By the rotation of the planetary gear, the rotation speed of the planetary arm by the electric motor is reduced and transmitted to the advancing / retreating mechanism. By operating the advancing / retreating mechanism to generate a pressing force on the pressing member of the friction pad, the friction pad is pressed against the disc rotor and braking is performed.

[0012] When some adhesion is caused in the electric motor, the reduction gear mechanism, the forward / backward moving mechanism, etc. while the disk rotor is pressed by the friction pad, the braking may not be released. The electric motor is fixed because the electric motor is fixed due to a voltage drop, a line failure or the like, or foreign matters are caught between the gears of the reduction gear mechanism so that the respective parts such as gears are fixed and the rotation failure occurs. , The deceleration gear mechanism, the advancing / retreating mechanism, and the like individually, as well as the fixing between the electric motor and the reducing gear mechanism, the fixing between the decelerating gear mechanism and the advancing / retreating mechanism, or between the electric motor and the advancing / retreating mechanism. It also includes mutual fixing such as fixing at each other. In such a case, the clamping force releasing means of the present invention allows the clamping force to be easily released by a simple manual operation without using electric power or the like. To this end, the fixing of the sun gear by the fixing member is released, and the rotatable sun gear is rotated in the braking release direction using a tool or the like.

Due to the rotation of the sun gear, the planetary gear rotates, and the advancing / retreating mechanism, which has moved forward in the friction pad direction and generated the pressing force on the pressing member, retracts in the direction opposite to the friction pad. Since the pressing force is released by the retraction of the advancing / retreating mechanism, the friction pad is separated from the disc rotor,
The clamping force can be released. By releasing the clamping force, the wheels can be operated, and the towing operation of the vehicle to the repair shop or the like can be performed without any trouble.

Further, the fixing member of the sun gear can be constituted by any mechanism as long as it can easily fix and release the fixing of the sun gear by manual operation. For example,
The fixing member is configured to be engaged with the sun gear by the pressing plate and to be urged toward the pressing plate by the urging means having an urging force smaller than the engaging force. Then, normally, the fixing member is engaged with the sun gear by the pressing plate to fix the sun gear in a non-rotatable manner. Also, when the clamping force needs to be released, the fixing member is automatically released from the sun gear by the urging force of the urging means by manually releasing the engagement of the fixing member by the pressing plate. However, the fixing of the sun gear is released, and the sun gear can be rotated. Thus, the fixing of the sun gear can be easily performed by a simple manual operation, the structure of the fixing means is simple, and the assembling property and the maintainability are improved.

As a further preferable structure for fixing the sun gear, the sun gear is provided with a circumferential groove concentric with the sun gear on the side of the holding plate, and the circumferential groove is provided at a constant interval. Formed by loosely inserting the small diameter tips of the fixed members arranged in a circle so that they can be slid relative to each other, and providing fixing holes in the circumferential groove at fixed intervals for inserting the large-diameter fitting portions of the fixing member. To do.
When fixing the sun gear, the large-diameter insertion portion of the fixing member is inserted into the fixing hole by the pressing plate to fix the sun gear in a non-rotatable manner.

When the clamping force is released, the fixing member is disengaged from the holding plate, and the large-diameter insertion portion of the fixing member is disengaged from the fixing hole to release the fixing of the sun gear. It is possible to rotate. Here, even when the fixing member is not completely removed from the sun gear and the small diameter tip is inserted in the circumferential groove, the small diameter tip does not move when the sun gear rotates. Since the inside relatively slides, the sun gear can be rotated without any trouble. After releasing the clamping force, the vehicle can be moved with the fixing member attached, and the loss of parts such as the fixing member can be prevented.

The advancing / retreating mechanism may be any conventionally known mechanism, for example, a ball screw nut having a diameter larger than that of the planetary gear of the reduction mechanism and pivotable by the rotation of the planetary gear. A ball screw mechanism including a ball screw shaft that moves back and forth in the direction of the disk shaft by rotating the ball screw nut can be used. Then, by rotating the large diameter ball screw nut with the planetary gear, the rotational motion reduced by the reduction gear mechanism is further reduced, so that the rotational motion of the planetary arm by the electric motor is changed to that of the ball screw shaft. It is possible to efficiently convert it into forward and backward movements and generate a strong pressing force on the pressing member.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings. (1) is a disk rotor which rotates integrally with a wheel of an automobile and faces both friction surfaces (2). Figure 1
As shown in FIG. 3, a pair of friction pads (3) and (4) are arranged inside the tire wheel (5). Further, the bracket (6) is attached to the vehicle body so as to face the disc rotor (1).
Fixed to the caliper support arm (7) projecting from the fixed side by straddling the outer periphery of the disc rotor (1) to the opposite side,
The friction pads (3) and (4) are slidably arranged.

Further, as shown in FIG. 2, a pair of caliper bodies (8) for pressing the friction pads (3) and (4) against the disc rotor (1) are attached to the caliper support arms (7) of the bracket (6) as shown in FIG. It is connected via a slide pin (9) so that it can move back and forth. As shown in FIG. 1, the caliper body (8) includes an action portion (10) arranged on the back surface of one friction pad (3) with the disc rotor (1) sandwiched between it and the other friction pad (4). A reaction portion (12) provided with a reaction force claw (11) arranged on the back surface,
It is composed of a bridge portion (13) connecting the action portion (10) and the reaction portion (12) across the outer circumference of the disc rotor (1).

As shown in FIG. 1, the acting portion (10) is provided in the cylinder (14) with a brushless electric motor.
(15), a ball screw mechanism (16) for generating a pressing force of the friction pads (3), (4), and a deceleration for decelerating and transmitting the driving force of the electric motor (15) to the ball screw mechanism (16). It houses the gear mechanism (17). This reduction gear mechanism (17)
As shown in FIG. 8, a planetary arm (18) rotatable by a driving force of an electric motor (15), a planetary gear (23) pivotally supported by the planetary arm (18), and a planetary gear (23) It is composed of a sun gear (26) for rotating the planetary gear (23).

The planetary arm (18) is connected to the electric motor (1).
A cylindrical portion (20) having a magnet (39) acting as a rotor of (5) arranged on the outer periphery and a diameter larger than the cylindrical portion (20), and provided at the rear side opposite to the friction pad (3) Large diameter part
It consists of (21) and, by the driving force of the electric motor (15),
The inside of the cylinder (14) is rotatable via the bearing (57). Then, as shown in FIG. 8, planetary gears (23) are rotatably supported by notches (22) provided at three locations on the outer periphery of the large diameter portion (21). Further, as shown in FIGS. 2 and 8, the large-diameter portion (21) cuts the outer circumference between adjacent planetary gears (23) in a triangular shape to reduce the weight of the planetary arm (18) and to be described later. The rotation angle sensor can be used as a rotor.

The planetary gear (23) has a first gear part (2).
4) and a second gear having a smaller number of teeth than the first gear part (24)
The gear part (25) is formed integrally by separating it in the front and rear in the axial direction, and the first gear part (24) is attached to the sun gear (26) fixed to the caliper body (8) in a non-rotatable manner. The sun gear (26) meshes with each other, and the planetary gear (23) can be rotated.

Then, in the planetary arm (18), a bearing portion is provided.
The ball screw nut (34) of the ball screw mechanism (16) is rotatably accommodated via (58). The bearing portion (58) of the ball screw nut (34) is locked at both ends on the side of the planetary arm (18) as shown in FIG. 3 so that it cannot move in the direction of the disc axis. The part (58) can be removed. Further, the ball screw nut (34) is supported by the sun gear (26) through a bearing portion (67) arranged between the ball screw nut (34) and the sun gear (26), and is rotatable but the sun gear (34) is rotatable.
It is prevented from moving backward in the (26) direction. Further, the ball screw nut (34) fixes the reduction gear (35) having a smaller number of teeth than the sun gear (26) to the outer periphery of the rear end of the planetary arm (18) located on the large diameter portion (21) side. ing. This reduction gear (35)
Meshes with the second gear part (25) of the planetary gear (23),
The ball screw nut (34) is rotated by the rotation of the planetary gear (23).
It is possible to rotate. A ball screw shaft (38) is screwed into a ball groove (36) provided on the inner diameter side of the ball screw nut (34) through a plurality of balls (37) so as to be movable back and forth.

Further, the ball screw shaft (38) is provided at the tip,
As a pressing member of the friction pad (3), a flat pad pressing plate (40) is inseparably connected to each other. With this pad pressing plate (40), the friction pad (3) is pressed in a large area without concentrating the pressing force on a part, and the disc rotor is rotated.
It can be pressed in parallel with (1).

A dust seal which can expand and contract between the outer periphery of the pad pressing plate (40) and the inner periphery of the cylinder (14).
(47) is connected to cover the opening (45) of the cylinder (14) to prevent dust, water droplets, pebbles, etc. from entering the cylinder (14). In order to further improve the sealing performance inside the cylinder (14), the ball screw shaft (38) and the pad pressing plate (40) are connected as follows.

First, as shown in FIG. 1, the ball screw shaft (3
In 8), the inside is formed in a hollow shape, a hollow portion (41) is provided, and a fixing wall (49) for fixing the mounting screw (42) is formed on the friction pad (3) side. Also, the pad pressing plate (4
A mounting hole (43) in the shape of a bag hole is recessed on the back surface of (0). Further, as shown in FIG. 4, in the center of the ball screw nut (34), the sun gear (26), and the cap (33) of the back plate (27), hexagonal tool holes (61) (62) (63) are respectively formed. ) Is opened, and various parts can be assembled and disassembled by inserting bolts and tools. And the tool hole (61)
(62) Through (63), the hollow part of the ball screw shaft (38)
Insert the mounting screw (42) into the (41) and
(42) is screwed into the mounting hole (43) of the pad pressing plate (40) through the fixing wall (49) of the ball screw shaft (38), so that the ball screw shaft (38) and the pad pressing plate (40) is inseparably connected.

With this structure, the pad pressing plate (40) includes the inside of the cylinder (14) and the friction pad (3).
No hole or the like communicating with the outside on the side is formed, and the connection between the pad pressing plate (40) and the ball screw shaft (38) is covered with the pad pressing plate (40) and the dust seal (47). It will be done in the designated space. Therefore, the sealing property of the opening (45) of the cylinder (14) is improved, and it is possible to reliably prevent the intrusion of fine dust and a small amount of water droplets into the cylinder (14) from the friction pad (3) side. . Further, since the pad pressing plate (40) and the ball screw shaft (38) can be connected from the rear side of the caliper body (8), the assembling property and the maintainability are also improved.

Further, in order to reduce the heat conduction on the outer surface of the caliper body (8), the caliper body (8) is replaced by an electric motor.
3 on the friction pad (3) side of (15) and the reduction gear mechanism (17) side
As shown in FIG. 1, a heat insulating ring member (46) made of a heat insulating material having a lower thermal conductivity than that of the caliper body (8) is inserted and arranged between the parts so as to be divided. By this heat insulating ring member (46), the braking heat of the friction pads (3) (4) is transferred to the electric motor (15) and the reduction gear mechanism (17) via the outer surface of the caliper body (8). And the driving heat of the electric motor (15) is reduced by the reduction gear mechanism.
It can also be prevented from being transmitted to (17).

Since the heat insulating ring member (46) is formed by dividing the main body of the caliper body (8) and inserting and arranging between the parts, when the heat insulating member is provided inside the caliper body (8). Compared to, it is easier to assemble and does not affect productivity. Further, by forming the parts separately, it is possible to improve the assembling property and the maintainability of various parts inside the caliper body (8).

As shown in FIGS. 1 and 5, a load sensor (48) is provided at the tip of the ball screw shaft (38) to detect the load applied to the friction pad (3). Then, as shown in FIG. 1, the harness (50) for connecting the load sensor (48) and the detector body (not shown) is provided with a ball screw shaft (38).
It is inserted in the hollow part (41) of the. In addition, the harness (5
0) is arranged in the hollow portion 41 with a sufficient length according to the moving distance of the ball screw shaft 38 to move forward and backward. However, there is a risk that the slack in the allowance portion may enter into the gap between the parts and cause catching or cutting.

In order to solve this problem, as shown in FIG. 1, the harness (50) is tensioned and urged by the tension spring (51) so that the slack portion is always disposed in the hollow portion (41).
Outside of (41), the harness (50) is always in tension. Then, even if the ball screw shaft (38) advances toward the friction pad (3) and a tensile force is applied to the harness (50), the tensile spring (51) expands, so that the harness (50) is hard to be cut. Becoming, ball screw shaft
(38) It becomes difficult to hinder the forward movement. Further, when the ball screw shaft (38) retracts, the tension spring (51) restores and contracts, so that it is possible to prevent the harness (50) from loosening at a position other than the hollow portion (41).

Further, the rotation angle of the planetary arm (18) is detected in order to adjust the pressing of the disc rotor (1) by the friction pads (3) and (4) at the time of braking to enable proper braking. A rotation angle sensor is provided, and the drive of the brushless electric motor (15) can be controlled and the amount of advance / retreat of the ball screw shaft (38) can be calculated based on the rotation angle detected by the rotation angle sensor. In this rotation angle sensor, as shown in FIGS. 2 and 4, the triangular large diameter portion (21) of the planetary arm (18) is used as the rotor of the rotation angle sensor, and as shown in FIGS. Most (2
A coil (19) is circumferentially arranged on the inner peripheral surface of the cylinder (14) so as to face the outer periphery of (1) to form a stator.

Then, since the triangular large-diameter portion (21) rotates around the inner circumference of the coil (19) to generate a waveform output voltage, the rotation angle sensor detects the planet arm (18). It is possible to detect the rotation angle of. Thus, the planetary arm (1
Since the large diameter part (21) of 8) can be used as a rotor, it is not necessary to provide a rotor for the rotation angle sensor separately from the planetary arm (18), and it is possible to prevent an increase in the number of parts and the number of assembling steps. it can.

Further, as shown in FIGS. 1 and 4, the planetary arm (1
A solenoid (54) of the parking mechanism is provided on the back plate (27) so as to face the rear end surface of the large diameter portion (21) of (8). When the vehicle is parked, the friction pad (3)
While braking by (4), solenoid (54)
The lock pin (55) engages with any one of the locking holes (56) provided in the end surface of the large diameter portion (21) of the planetary arm (18) when the lever is actuated. By this engagement, the planetary arm (18) is fixed so that it cannot rotate, and the braking by the friction pads (3) and (4) can be maintained. Also, an O-ring is provided on the outer periphery of the back plate (27).
The covering cover (44) is attached via (60) and is fixed with a plurality of fixing screws (59). By this cover (44), the solenoid (54) and the back plate (27),
Tool holes (61) as well as protecting others from external impact
Water and dust are prevented from entering the cylinder (14) via (62) and (63).

Then, with the friction pads (3) and (4) pressed against the disc rotor (1), the electric motor (15), the reduction gear mechanism (17), and the ball screw mechanism (1) constituting the forward / backward moving mechanism.
6) and the like, if some kind of sticking occurs and the braking cannot be released, as a means for releasing the clamping force, in the embodiment of the present invention, the sun gear (26 ) Is carried out by manually rotating. Therefore, as shown in FIGS. 1, 3 and 7, the sun gear (26) is provided on the back surface of the back plate (27) side with the sun gear (26).
A circumferential groove (52) that is concentric with (26) is recessed, and the circumferential groove (52) is
A plurality of fixing holes (30) having a diameter larger than that of the circumferential groove (52) are opened in the (52) in a circumferential shape at regular intervals.

Corresponding to the plurality of fixing holes (30), a plurality of insertion holes (29) are opened in the back plate (27), and a sun gear (26) is provided in each of the insertion holes (29). ), The pin-shaped fixing member (28) is inserted, and the fixing member (28) is inserted into the fixing hole (30) recessed in the back surface of the sun gear (26) to The gear (26) is non-rotatably fixed to the back plate (27).

Further, as shown in FIG. 7, the fixing member (28) is formed such that the tip side thereof has substantially the same diameter as the formation width of the circumferential groove (52) of the sun gear (26). 52) Freely inserted into the circumferential groove
A small-diameter tip portion (64) capable of relatively sliding in the (52) is provided, and a large-diameter insertion portion (which can be inserted into the fixing hole (30) continuously with the small-diameter tip portion (64) ( 65) is provided. Then, a brim-shaped pressing plate (53) is projectingly provided on the cap (33) to be screwed into the mounting hole (32) of the back plate (27), and the pressing plate (53) is mounted when the cap (33) is mounted. ) Fixing member
The head (66) of (28) is engaged with the back plate (27). By this engagement, the large diameter insertion portion (6) of the fixing member (28)
5) is inserted into the fixing hole 30 and the inserted state is maintained.

Further, as described above, the fixing member (28) is inserted into the insertion hole (29) of the back plate (27) and the fixing hole (30) of the sun gear (26) to back the sun gear (26). plate
There is a case where the insertion hole (29) and the fixing hole (30) are displaced from each other when they are fixed to (27). However, the fixing hole (30) of the sun gear (26) is provided with a circumferential groove.
Since it is provided in (52), the insertion hole (29) and the fixing hole (30)
It is possible to surely insert the fixing member (28). That is,
After the fixing member (28) is inserted into the insertion hole (29) in the above-mentioned misaligned state, the small-diameter tip portion (64) of the fixing member (28) is loosely inserted into the circumferential groove (52).

Next, when the sun gear (26) is rotated in the circumferential direction while the fixing member (28) is supported by the pressing plate (53) of the cap (33), the fixing member (28) is thinned. Diameter tip
(64) slides in the circumferential groove (52) relative to each other. Then, when the position of the fixing hole (30) and the large-diameter insertion portion (65) are aligned by the rotation of the sun gear (26), the cap is released.
By performing the screwing operation of (33), the fixing member (28) is engaged with the back plate (27) by the pressing plate (53), and the large diameter insertion portion (65) of the sun gear (26). It will be surely inserted into the fixing hole (30).

By inserting the large diameter insertion portion (65) into the fixing hole (30), the sun gear (26) is non-rotatably fixed, and the sun gear (26) is attached to the ball screw nut (34). ) Direction, the sun gear (26) and the back plate (2
As shown in FIG. 3, a gap portion (68) is formed between the gap (7) and 7). In addition, the fixing member (28) is provided with a pressing spring (31) between the head (66) and the back plate (27), and the cap (33) is loosened to be engaged by the pressing plate (53). When released, the fixing member is urged by the urging force of the pressing bar (31).
It is assumed that (28) is disengaged from the fixing hole (30) and the fixing of the sun gear (26) is released.

In the electric disc brake constructed as described above, when the driver of the automobile depresses the brake pedal to perform the braking operation, the electric motor (15) is driven according to the amount of depression, and the planetary arm (18) ) Rotates in the cylinder (14). Due to the rotation of the planetary arm (18), the large diameter portion (2
A planetary gear (23) which is axially supported by 1) and which meshes the first gear portion (24) with the sun gear (26) rotates around the outer periphery of the sun gear (26). The rotation of the planetary gear (23) causes the second gear part to rotate.
Ball screw nut that engages reduction gear (35) with (25)
(34) is rotated.

Then, due to the action of the ball screw mechanism (16), the rotational force of the ball screw nut (34) is changed to the ball screw shaft.
(38) is converted into a forward force in the direction of the friction pad (3), and the friction pad on the action portion (10) side is passed through the pad pressing plate (40).
(3) is pressed and slid, and pressed against the disc rotor (1).
Furthermore, the reaction force of the forward movement of the ball screw shaft (38) causes the caliper body (8) to retract, and the reaction force claw (11) of the reaction portion (12)
Braking is performed by pressing and sliding the friction pad (4) on the side of the reaction portion (12) and pressing it against the disc rotor (1).

During this braking, as described above, the planetary gears are used.
(23) is the first gear part (24) that meshes with the sun gear (26)
The number of teeth of the second gear part (25) that meshes with the reduction gear (35) of the ball screw nut (34) is smaller than that of the sun gear (26) in this second gear part (25). The reduction gear (35) having a small number of teeth is rotated. By these actions, the rotation of the planetary arm (18) by the electric motor (15) is efficiently decelerated and converted into the rotation of the ball screw nut (34) having a strong torque, so that the friction pads (3) (4) ), A strong pressing force is generated, and effective braking can be performed.

When the depression of the brake pedal is released, the planetary arm (18) rotates in the opposite direction to that during braking under the control of the electric motor (15), and the ball screw nut (34) is passed through the planetary gear (23). ) Rotates in the opposite direction to the previous rotation, the ball screw shaft (38) retracts, and the friction pad (3)
Is released. Further, due to the reaction force of the backward movement of the ball screw shaft (38), the caliper body (8) also slides in the restoring direction, and the pressing of the friction pad (4) on the reaction portion (12) side is released, so braking is performed. It is canceled.

However, when the disk rotor (1) is pressed by the friction pads (3) and (4), the electric motor (15),
If the deceleration gear mechanism (17), the ball screw mechanism (16), or the like should have some adhesion, it may not be possible to release the braking. The sticking means a voltage drop,
The electric motor (15) may become stuck due to a line failure, the meshing part between the planetary gear (23) and the sun gear (26), or the screwing part between the ball screw nut (34) and the ball screw shaft (38). At this time, the reduction gear mechanism is
(17) and the ball screw mechanism (16) are fixed individually, as well as the planetary arm of the electric motor (15) and the reduction gear mechanism (17).
Sticking with (18) by baking, reduction gear mechanism (17)
Sun gear (26) and reduction gear of ball screw mechanism (16)
Electric motor (15), reduction gear mechanism, such as sticking to (35)
(17), the ball screw mechanism (16) and the like are also included in the case where they are fixed to each other.

In such a case, the clamping force releasing means of the present invention can easily release the clamping force by a simple manual operation. For this purpose, as shown in FIG. 4, the fixing screw (59) of the cover cover (44) is removed, and the cover cover (44) and the O-ring (6) are removed from the back plate (27).
Remove 0). Next, when the cap (33) is rotated and loosened in the direction in which it is separated from the back plate (27), as shown in FIG. 5, the pressing plate () for the fixing member (28) that fixes the sun gear (26) is fixed. The engagement by 53) is released. By this release of the pressure, the pressure spring (31) is restored, and the restoring force moves the fixing member (28) in the direction of disengagement from the fixing hole (30) of the sun gear (26). The pressing biasing force acting toward the ball screw nut (34) is released.

Further, a friction pad for the disc rotor (1)
(3) By the reaction force of the pressure of (4), the ball screw nut (34)
A strong urging force is applied to the sun gear (26), and the ball screw nut (34) passes through the bearing (67) to the sun gear.
It is pressed against (26). Therefore, when the pressing biasing force to the sun gear (26) is released by the movement of the fixing member (28) as described above, the sun gear (26) and the ball screw mechanism are
(16) The entire unit retracts toward the back plate (27).
This retreat is performed by the distance of the gap portion (68) interposed between the sun gear (26) and the back plate (27), the sun gear (26) hits the back plate (27), and the retreat is performed. Be stopped. Further, due to the retreat of the sun gear (26), the fixing member (28) remains inserted into the fixing hole (30) and the sun gear (26) cannot rotate at the time of FIG. .

The sun gear (26) and the ball screw mechanism
Only by retreating (16), the clamping force by the friction pads (3) and (4) on the disc rotor (1) can be reduced. However, the friction pads (3) and (4) are replaced by the disc rotor (1).
In order to release the clamping force from the friction surface (2) of (1), the cap (33) should be further loosened.
As shown in FIG. 6, the fixing member is restored by the restoring force of the pressing bar (31).
(28) moves further in the separating direction. At this time, the sun gear
Since (26) hits the back plate (27) and is prevented from moving backward, only the fixing member (28) moves,
The large diameter insertion portion (65) of the fixing member (28) is
Completely separate from the fixing hole (30) of 6).

However, even if the large-diameter insertion portion (65) is detached from the fixing hole (30), the small-diameter tip portion (64) is loosely inserted in the circumferential groove (52). However, the thin tip (64) has a circumferential groove (5
2) Because it can slide inside, the fixing member (28)
The sun gear (26) is no longer fixed by the sun gear (2)
6) can be rotated without hindrance. And the cap
Through the tool hole (63) of (33), insert a special tool such as a hex wrench into the tool hole (62) of the sun gear (26), and engage.
This tool rotates the sun gear (26) in the braking release direction. By this rotation, the sun gear (26) is attached to the first gear portion.
The planet gear (23) meshing with (24) rotates,
Ball screw nut that meshes with the second gear part (25) of (23)
(34) rotates.

By the rotation of the ball screw nut (34), the ball screw shaft (38) retracts in the direction opposite to the friction pad (3), and therefore the pad pressing plate (40) connected to the ball screw shaft (38). ) Retracts with the friction pad (3), and the friction pad (3) separates from the disc rotor (1). Also,
The caliper body (8) advances toward the disc rotor (1) by the reaction force of the backward movement of the ball screw shaft (38), so that the pressing force on the friction pad (4) on the reaction portion (12) side is also released. Therefore, the friction pad (4) is also separated from the disc rotor (1), and the clamping force can be released.

Since the wheel can be rotated by releasing the clamping force, the vehicle can be moved to a road shoulder, a repair shop, or the like. As described above, the cap provided with the pressing plate (53) for engaging the fixing member (28) with the sun gear (26)
The clamping force can be easily released by a simple operation of loosening (33) to release the fixing of the sun gear (26) and rotating the sun gear (26) with a tool. Further, since it is not necessary to completely remove the cap (33) and the fixing member (28), the vehicle can be moved and other work can be performed with the cap (3) attached to the back plate (27).
It is also possible to prevent the loss of small parts such as 3), the fixing member (28), and the pressing bar (31). Also, after releasing the clamping force, the O-ring (60) and the covering cover (44) that were previously removed were removed.
Can be reattached and used.

Further, in this embodiment, since the gap portion (68) between the sun gear (26) and the back plate (27) is formed, the ball screw mechanism corresponds to the distance of the gap portion (68).
(16) The clamping force can be reliably released by rotating the ball screw mechanism (16) via the sun gear (26), although it can be performed only by retracting the whole. Therefore, it is not necessary to provide the gap portion 68 in a long length, and it is possible to prevent the disc rotor 1 from becoming long in the direction of the disc axis.

[0053]

The present invention, which is configured as described above, has an electric motor when the friction pad is pressed against the disc rotor.
If the reduction gear mechanism, advancing / retreating mechanism, etc. become stuck and braking cannot be released, the sun gear is unfixed and the sun gear is manually rotated to press the friction pad. The member can be returned to the non-braking position, the friction pad can be separated from the disc rotor, and the clamping force can be released. Therefore, the clamping force can be released easily by a simple manual operation without requiring electric power, etc., and the reliability and workability of releasing the clamping force are improved. Further, the fixing and releasing means for fixing the sun gear can be formed with a simple structure by using a fixing member, and the productivity can be improved. In addition, it is not necessary to provide a lot of space for releasing the clamping force in the caliper body,
By preventing the caliper body from becoming long in the direction of the disc axis, it is possible to make the caliper body more compact and increase the degree of freedom in layout when installing the electric disc brake.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an electric disc brake installed facing a disc rotor according to an embodiment of the present invention.

2 is a cross-sectional view taken along the line AA of FIG. 3, in which the fixing member of the sun gear and the harness are omitted.

FIG. 3 is a partially enlarged sectional view of the back plate side of FIG.
The state where the sun gear is fixed non-rotatably by a fixing member is shown.

FIG. 4 is an enlarged cross-sectional view showing a state in which the covering cover is removed from the caliper body in the step of releasing the clamping force.

FIG. 5 is an enlarged cross-sectional view showing a state in which the fixing member is disengaged from the holding plate by loosening the cap, and the sun gear and the ball screw mechanism move in the back plate direction.

FIG. 6 is an enlarged cross-sectional view showing a state in which the large-diameter insertion portion of the fixing member is released from the fixing hole of the sun gear and the fixing of the sun gear is released.

FIG. 7 is an enlarged cross-sectional view near the fixing member in FIG.

FIG. 8 is a perspective view of a reduction gear mechanism.

[Explanation of symbols]

1 disk rotor 3 friction pad 4 friction pad 8 caliper body 15 Electric motor 16 Ball screw mechanism (forward / backward movement mechanism) 17 Reduction gear mechanism 18 planetary arms 23 planetary gears 26 sun gear 28 Fixing member 30 fixing holes 34 Ball screw nut 38 Ball screw shaft 40 Pad pressing plate (pressing member) 52 circumferential groove 53 Press plate 64 small diameter tip 65 Large diameter insertion part

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[Procedure amendment]

[Submission date] May 27, 2002 (2002.5.2)
7)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

Title of Invention Arrangement structure of electric disc brake ────────────────────────────────────── ───────────────

[Procedure amendment]

[Submission date] May 30, 2002 (2002.5.3)
0)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

Title of invention Electric disc brake

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

Claims (4)

[Claims] 1. An advancing / retreating mechanism for advancing / retreating by a driving force of an electric motor to generate a pressing force on a pressing member of a friction pad, and a reduction gear mechanism for decelerating and transmitting the driving force of an electric motor to the advancing / retreating mechanism. In an electric disc brake that is provided on a caliper body and performs braking by sliding a friction pad against the disc rotor by the advancing / retreating mechanism, the reduction gear mechanism includes a planetary arm rotatable by an electric motor, The planetary gear is rotatably supported on the outer circumference of the planetary arm, and the sun gear is fixed to the caliper body by a fixing member so as to be non-rotatable and rotates the planetary gear. When the electric motor, the reduction gear mechanism, and the advancing / retreating mechanism become stuck while the pad is pressed, the fixing of the sun gear by the fixing member is released to make the sun gear rotatable. By this, the arrangement structure of the electric disc brake is characterized in that the advancing / retreating mechanism is manually operated via the reduction gear mechanism to provide a clamping force releasing means for forcibly returning the pressing member of the friction pad to the inoperative state. . 2. The fixing member is engaged with the sun gear by the pressing plate and is urged toward the pressing plate by the urging means having an urging force smaller than this engaging force, and the fixing member is fixed to the sun gear by the pressing plate. When the sun gear is engaged and fixed so that it cannot rotate, and when the clamping force is released, the fixing member is disengaged by the pressing plate, and the fixing member is disengaged from the sun gear by the urging force of the urging means. 2. The arrangement structure of an electric disc brake according to claim 1, wherein the fixing of the gear is released and the sun gear is rotatable. 3. The sun gear is provided with a circumferential groove concentric with the sun gear on the side of the holding plate, and a small-diameter tip of a fixing member circumferentially arranged in the circumferential groove at regular intervals. Part is loosely slidable relative to each other, and fixing holes for inserting large-diameter insertion parts of the fixing member are provided in the circumferential groove at regular intervals. The sun gear is fixed so that it cannot be rotated by inserting the diameter insertion part into the fixing hole, and when the clamping force is released, the engagement of the fixing member by the pressing plate is released to fix the large diameter insertion part of the fixing member. 3. The sun gear is released from the fixing hole to release the fixing of the sun gear, and the sun gear can be rotated while relatively sliding the small-diameter tip of the fixing member in the circumferential groove. Arrangement structure of electric disc brakes. 4. The advancing / retreating mechanism is a ball screw nut having a diameter larger than that of the planetary gear of the reduction gear mechanism and rotating by the rotation of the planetary gear, and the advancing / retreating in the direction of the disk shaft by the rotation of the ball screw nut. It consists of a moving ball screw shaft, and by rotating a large diameter ball screw nut with a planetary gear, the rotational force transmitted from the reduction gear mechanism is further reduced, and a pressing member is applied via the ball screw shaft. The arrangement structure of the electric disc brake according to claim 1, wherein a pressing force is generated.