JP6719916B2 - Electric brake device and method of manufacturing electric brake device - Google Patents

Description

The present invention relates to an electric brake device that uses an electric motor as a drive source, and a method for manufacturing the electric brake device.

Conventionally, as a vehicle brake device, a hydraulic brake device using hydraulic pressure as a drive source has been widely adopted, but the hydraulic brake device uses a brake oil and thus has a high environmental load, and also has an ABS and a stability control system. , It is difficult to further enhance the functions such as brake assist. Therefore, an electric brake device using an electric motor as a drive source has been attracting attention as a means for realizing further higher functionality of the brake device and reduction of environmental load.

As an electric brake device, for example, one disclosed in Patent Document 1 is known. The electric brake device described in Patent Document 1 includes a brake disc that rotates integrally with a wheel, inner and outer brake pads that axially face each other with the brake disc interposed therebetween, and a brake disc of the outer brake pad. A caliper body having a claw portion for supporting a side surface opposite to the opposite side (hereinafter referred to as "back surface of outer brake pad"), and a side surface opposite to a side of the inner brake pad facing the brake disc ( Hereinafter, a single electric linear actuator that presses the "back surface of the inner brake pad").

This electric linear actuator has a piston arranged to face the back surface of the inner brake pad, an electric motor, and a linear mechanism that converts the rotation of the electric motor into a linear motion of the piston. Here, the piston is housed in a housing hole formed directly in the caliper body so as to be movable parallel to the axial direction of the brake disc.

In this electric brake device, when the electric motor rotates, the rotational driving force of the electric motor is transmitted to the piston via the linear motion mechanism, and the piston moves linearly. The piston presses the back surface of the inner brake pad, so that the inner brake pad is pressed against the brake disc. At this time, the caliper body, which is axially movable with respect to the brake disc, moves axially toward the inner side due to the axial reaction force that the inner side brake pad receives from the brake disc, and the rear portion is moved back by the claw portion of the caliper body. The outer side brake pad supported by is pressed against the brake disc. In this way, the inner side and outer side brake pads are pressed against the brake disc, and the friction between the contact surfaces generates a braking force on the brake disc.

JP, 2005-137667, A

The electric brake device described in Patent Document 1 is for a small load, which is assumed to be used for a rear wheel of a vehicle of a general size and a front wheel of a small vehicle. Here, the inventor of the present application uses an electric brake device as disclosed in Patent Document 1 for heavy loads (for example, a brake device for a front wheel of an automobile of a general size or a brake for a large automobile such as a bus or a truck). It was considered to be adopted as a device).

However, the inventor has noticed the following problems when the electric brake device described in Patent Document 1 is used for a large load. That is, in the electric brake device described in Patent Document 1, the number of electric linear actuators that press the back surface of the inner brake pad is one, and accordingly, the number of pistons that press the back surface of the inner brake pad are increased. The number is also one.

Therefore, since a large load (large braking force) is generated, if the pressing force that acts on the inner brake pad from the piston is increased, the pressure between the inner brake pad and the brake disc will be uniform over the entire inner brake pad. It doesn't happen. As a result, the problem of fading (a phenomenon in which the friction part of the brake pad becomes hot and gas is generated and the frictional force between the inner brake pad and the brake disc decreases due to the gas) tends to occur. It has been found that there is a problem that the side brake pad is easily worn locally.

Then, the inventor has proposed in-house the following configuration as an electric brake device for a large load in which a fade phenomenon is unlikely to occur even when a large load is generated, and local wear of a brake pad is unlikely to occur. ..
A caliper body having a claw portion that supports a side surface of a pair of brake pads that are opposed to each other in the axial direction with the brake disk interposed therebetween and that is opposite to the side opposite to the brake disk.
First and second electric linear actuators that press a side surface of the other brake pad of the pair of brake pads on the side opposite to the side facing the brake disc at two locations separated in the circumferential direction of the brake disc. When,
Electric brake device having a.

Since the electric brake device having the above-described structure is configured to press the back surface of the brake pad at two locations that are separated in the circumferential direction, even when the pressing force that acts on the brake pad is increased, the pressure between the brake pad and the brake disc is increased. The entire surface of the brake pad tends to be uniform. Therefore, even when a large braking force is generated, the fade phenomenon is unlikely to occur and the wear of the brake pads is unlikely to progress.

Here, although the inventor differs in the number of electric linear actuators between the electric brake device for large loads and the electric brake device for small loads, the electric brake device for large loads and the electric brake device for small loads are different. I have noticed that the electric linear actuator can have the same shape as the electric brake device.

The problem to be solved by the present invention is to reduce the manufacturing cost of a heavy-duty electric brake device in which a fade phenomenon is unlikely to occur and the wear of a brake pad is less likely to proceed.

In order to solve the above problems, the present invention provides an electric brake device having the following configuration.
A caliper body having a claw portion that supports a side surface of a pair of brake pads that are opposed to each other in the axial direction with the brake disk interposed therebetween and that is opposite to the side opposite to the brake disk.
First and second electric linear actuators that press a side surface of the other brake pad of the pair of brake pads on the side opposite to the side facing the brake disc at two locations separated in the circumferential direction of the brake disc. Has and
The electric brake device in which the first and second electric linear actuators are detachably attached to the caliper body.

With this configuration, since the back surface of the brake pad is pressed at two locations that are separated in the circumferential direction, even when the pressing force that acts on the brake pad is increased, the pressure between the brake pad and the brake disc is reduced. The entire surface of the pad tends to be uniform. Therefore, when a large load is generated, the fade phenomenon does not easily occur, and the wear of the brake pad does not easily proceed.

Further, since the first and second electric linear motion actuators are respectively attachable to and detachable from the caliper body, at least one of the first and second electric linear motion actuators is used to manufacture an electric brake device for small loads. It is possible to reduce the manufacturing cost of the electric brake device by sharing the electric linear motion actuator used in the above. That is, it is possible to manufacture an electric brake device for a small load by mounting the electric linear actuator having the same shape as either the first or the second electric linear actuator on the caliper body for a small load. .. In this way, when manufacturing electric brake devices for heavy loads and small loads, the electric linear actuator of the electric brake device for large loads and the electric linear actuator of the electric brake device for small loads are used. It can be shared, and the manufacturing cost of the electric brake device can be reduced.

The above electric brake device preferably has the following configuration.
The first electric direct-acting actuator includes a first piston that is arranged to face a side surface of the other brake pad opposite to a side that faces the brake disc, and a shaft of the brake disc. A first piston housing that is movably accommodated in parallel with the direction and is detachably fixed to the caliper body; a first electric motor; and rotation of the first electric motor that is converted into linear motion of the first piston. Having a first linear motion mechanism,
The second electric direct-acting actuator faces the side surface of the other brake pad opposite to the side facing the brake disc at a position distant from the first piston in the circumferential direction of the brake disc. A second piston that is disposed so as to be movable, a second piston housing that accommodates the second piston so as to be movable parallel to the axial direction of the brake disc, a second electric motor, and a rotation of the second electric motor. A second linear motion mechanism that converts the linear motion of two pistons,
The first and second pistons have the same shape as each other,
The first and second piston housings have the same shape as each other,
The first and second electric motors have the same shape,
The first and second linear motion mechanisms have the same shape.

With this configuration, since each component of the first electric linear motion actuator and each component of the second electric linear motion actuator have the same shape, the manufacturing cost of the electric brake device can be more effectively reduced. Is possible.

Further, the above electric brake device may have the following configurations.
The first electric linear motion actuator has two first caliper arms extending on both sides in the circumferential direction of the brake disc, and one of the two first caliper arms has the caliper body. The first slide pin that supports the brake disc so as to be movable parallel to the axial direction is fixed,
The second electric linear motion actuator has two second caliper arms extending on both sides in the circumferential direction of the brake disc, and one of the two second caliper arms has the caliper body. A second slide pin, which is movably supported parallel to the axial direction of the brake disc, is fixed.

Furthermore, the first caliper arm of the two first caliper arms on the side where the first slide pin is not fixed is fixed to the caliper body, and the first caliper arm of the two second caliper arms is fixed. The second caliper arm on the side where the two slide pins are not fixed can be fixed to the caliper body.

In this case, it is preferable to adopt the following configuration.
The two first caliper arms are axially displaced from each other,
The two second caliper arms are axially displaced from each other,
Of the two first caliper arms, the first caliper arm on the side where the first slide pin is not fixed, and the second slide pin of the two second caliper arms are not fixed. The second caliper arm on the side is fixed to the caliper body with a common bolt in a state of overlapping in the axial direction.

With this configuration, the first caliper arm on the side where the first slide pin is not fixed and the second caliper arm on the side where the second slide pin is not fixed are arranged so as to overlap in the axial direction. Since the arms are overlapped with each other, the size of the electric brake device can be reduced.

The caliper body has two caliper arms extending parallel to the circumferential direction of the brake disc, and a slide that movably supports the caliper body on the two caliper arms in parallel with the axial direction of the brake disc. It is also possible to adopt a configuration in which the pins are fixed.

Further, the present invention provides the following configuration as a method for manufacturing an electric brake device for manufacturing a heavy load electric brake device and a small load electric brake device.
A caliper body for heavy load having a claw portion for supporting a side surface of one of the pair of brake pads opposed to each other in the axial direction with the brake disk interposed therebetween, the side surface being opposite to the side opposed to the brake disk. ,
First and second electric linear actuators that press a side surface of the other brake pad of the pair of brake pads on the side opposite to the side facing the brake disc at two locations separated in the circumferential direction of the brake disc. Use and
An electric brake device for heavy load is manufactured by detachably attaching the first and second electric linear actuators to the heavy caliper body.
A caliper body for small loads smaller than the caliper body,
At least one of the first and second electric linear actuators and an electric linear actuator of the same shape are used,
An electric brake device for small loads is manufactured by detachably attaching the electric linear actuator of the same shape to the caliper body for small loads.
Electric brake device manufacturing method.

By doing so, the electric linear motion actuator of the electric brake device for large loads and the electric linear motion actuator of the electric brake device for small loads can be shared, and the manufacturing cost of the electric brake device can be reduced. can do.

Since the electric brake device of the present invention is configured to press the back surface of the brake pad at two locations that are separated in the circumferential direction, even when the pressing force that acts on the brake pad is increased, the electric force between the brake pad and the brake disc is increased. The pressure tends to be uniform over the entire surface of the brake pad. Therefore, when a large load is generated, the fade phenomenon does not easily occur, and the wear of the brake pad does not easily proceed. Further, since the first and second electric linear motion actuators are respectively attachable to and detachable from the caliper body, at least one of the first and second electric linear motion actuators is used to manufacture an electric brake device for small loads. It is possible to reduce the manufacturing cost of the electric brake device by making it common to the electric linear motion actuator used for the.

The figure which saw a part of electric brake equipment of an embodiment of this invention, and was seen from the inner side. Sectional view taken along line II-II of FIG. The figure which looked at the electric brake equipment shown in FIG. 1 from the outer side. The figure which saw a part of electric brake equipment shown in Drawing 1, and was seen from the radial outside of a brake disc. Enlarged sectional view of the vicinity of the first linear motion mechanism of FIG. Sectional view taken along line VI-VI in FIG. The figure which shows an example of the electric brake device for small loads manufactured using the electric linear actuator of the same shape as the 1st electric linear actuator shown in FIG. Left side view of the electric brake device for small loads shown in FIG. The figure which looked at the electric brake device for small loads shown in FIG. 7 from the radial direction outer side of a brake disc. FIG. 1 is a perspective view showing an electric linear motion actuator having the same shape as the first electric linear motion actuator shown in FIG. The figure which shows the modification of the electric brake device for heavy loads shown in FIG. The figure which looked at the electric brake equipment shown in Drawing 11 from the radial direction outside of a brake disc. The figure which shows an example of the electric brake device for small loads manufactured using the electric linear motion actuator of the same shape as the 1st electric linear motion actuator shown in FIG. The figure which looked at the electric brake device shown in FIG. 13 from the radial direction outer side of a brake disc.

1 to 4 show an electric brake device 1 according to a first embodiment of the present invention. As shown in FIG. 2, the electric brake device 1 includes a brake disc 2 that rotates integrally with wheels (not shown), and inner and outer brake pads that axially face each other with the brake disc 2 interposed therebetween. A caliper body 6 having claws 3 and 4 for supporting the side surface of the outer brake pad 4 opposite to the side facing the brake disc 2 (hereinafter referred to as the "back surface of the outer brake pad 4"), The first side and the second side of the inner side brake pad 3 opposite to the side facing the brake disc 2 (hereinafter referred to as "the back side of the inner side brake pad 3") are pressed at two positions apart from each other in the circumferential direction of the brake disc 2. It has 2nd electric type linear motion actuator 7a, 7b (refer FIG. 1). Here, the inside and the outside in the vehicle width direction when the electric brake device 1 is assembled to the vehicle body are referred to as the inner side and the outer side, respectively.

As shown in FIG. 1, a pair of ear pieces 8 are formed at both ends of the inner brake pad 3. The ear piece 8 is slidably supported by a pair of guide grooves 10 formed in the mounting bracket 9. The mounting bracket 9 is fixed to the vehicle body immovably in the axial direction with respect to the brake disc 2. The guide groove 10 is a groove extending parallel to the axial direction of the brake disc 2. By the engagement of the guide groove 10 and the ear piece 8, the inner brake pad 3 is movably supported between a position where it contacts the inner side surface of the brake disc 2 and a position where it separates from it.

As shown in FIG. 3, a pair of ear pieces 11 is formed at both ends of the outer brake pad 4. The ear piece 11 is slidably supported by a pair of guide grooves 12 formed in the mounting bracket 9. The guide groove 12 is a groove extending parallel to the axial direction of the brake disc 2. By the engagement of the guide groove 12 and the ear piece 11, the outer brake pad 4 is movably supported between a position in contact with the outer side surface of the brake disc 2 and a position in which the brake disc 2 is separated from the outer side face.

As shown in FIG. 2, the inner brake pad 3 and the outer brake pad 4 are composed of a friction material 13 that contacts the brake disc 2, and a backing metal 14 that is provided by being adhered to the back surface of the friction material 13. The ear pieces 8 and 11 (see FIGS. 1 and 3) of the inner brake pad 3 and the outer brake pad 4 are formed integrally with the back metal 14.

The caliper body 6 has a claw portion 5 that axially faces the back surface of the outer brake pad 4, and an outer shell portion 15 that faces the outer diameter side of the brake disc 2. A screw hole 16 for fixing the first and second electric linear actuators 7a, 7b (see FIG. 1) is formed on the inner end surface of the outer shell portion 15.

As shown in FIGS. 1 and 4, the first electric direct-acting actuator 7 a has two first caliper arms 17 extending on both sides of the brake disc 2 in the circumferential direction. The first slide pin 18 is fixed to one of the two first caliper arms 17, and the other first caliper arm 17 is fixed to the caliper body 6 with bolts 19. The first slide pin 18 is a rod-shaped member that extends parallel to the axial direction of the brake disc 2, and is slidably inserted into a first pin hole 20 provided in the mounting bracket 9. The first electric linear motion actuator 7a is also fixed to the caliper body 6 with two bolts 21. The first electric direct-acting actuator 7a is attachable to and detachable from the caliper body 6 by attaching and detaching the bolts 19 and 21.

Similarly, the second electric linear motion actuator 7b also has two second caliper arms 22 extending on both sides of the brake disc 2 in the circumferential direction. The second slide pin 23 is fixed to one of the two caliper arms 22, and the other second caliper arm 22 is fixed to the caliper body 6 with bolts 19. The second slide pin 23 is a rod-shaped member that extends parallel to the axial direction of the brake disc 2, and is slidably inserted in a second pin hole 24 provided in the mounting bracket 9. The second electric linear motion actuator 7b is also fixed to the caliper body 6 with two bolts 25. The second electric direct-acting actuator 7b is attachable/detachable to/from the caliper body 6 by attaching/detaching the bolts 19 and 25.

Here, the caliper body 6 and the first and second electric linear motion actuators 7a and 7b fixed to the caliper body 6 are the first and second slide pins 18 and 23, and are in the axial direction of the brake disc 2. It is movably supported in parallel.

As shown in FIG. 4, the two first caliper arms 17 of the first electric linear motion actuator 7 a are arranged so as to be displaced from each other in the axial direction of the brake disc 2. Similarly, the two second caliper arms 22 of the second electric linear motion actuator 7b are also axially displaced from each other. Then, in a state where the axial position of the first electric linear actuator 7a and the axial position of the second electric linear actuator 7b are matched, the first caliper on the side where the first slide pin 18 is not fixed. The arm 17 and the second caliper arm 22 on the side where the second slide pin 23 is not fixed axially overlap each other, and the first and second caliper arms 17 and 22 are fixed to the caliper body 6 by the common bolt 19. Has been done.

As shown in FIG. 2, the first electric linear motion actuator 7a includes a first piston 26a arranged to face the back surface of the inner brake pad 3, and the first piston 26a in the axial direction of the brake disc 2. A first piston housing 27a that is movably accommodated in parallel, a first electric motor 28a, a first linear motion mechanism 29a that converts the rotation of the first electric motor 28a into a linear motion of the first piston 26a, and a first linear movement mechanism 29a. A first reduction gear train 30a that decelerates and transmits the rotation of the electric motor 28a to the first linear motion mechanism 29a.

Similarly, the second electric direct-acting actuator 7b is disposed at a position distant from the first piston 26a in the circumferential direction of the brake disc 2 so as to face the back surface of the inner brake pad 3 and face the second piston 26b( 4), a second piston housing 27b (see FIG. 4) that houses the second piston 26b so as to be movable parallel to the axial direction of the inner side brake disc 2, and a second electric motor 28b (see FIG. 1). And a second linear motion mechanism 29b (see FIG. 4) that converts the rotation of the second electric motor 28b into a linear motion of the second piston 26b, and the rotation of the second electric motor 28b is reduced to the second linear motion mechanism 29b. And a second reduction gear train 30b (see FIG. 1) for transmitting.

Here, each component of the first electric linear motion actuator 7a and each component of the second electric linear motion actuator 7b have the same shape (in the figure, the first and second electric linear motions). The actuators 7a and 7b are the same). That is, the first and second pistons 26a and 26b have the same shape, the first and second piston housings 27a and 27b have the same shape, and the first and second electric motors 28a and 28b have the same shape. The first and second linear motion mechanisms 29a and 29b have the same shape, and the first and second reduction gear trains 30a and 30b also have the same shape. Therefore, hereinafter, in the second electric linear motion actuator 7b, the portions corresponding to those of the first electric linear motion actuator 7a are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 2, the first piston housing 27a is arranged such that the claw portion 5 of the caliper body 6 and the first piston housing 27a face each other in the axial direction with the inner side and outer side brake pads 3 and 4 interposed therebetween. It is located in. A piston accommodating hole 31 is formed in the first piston housing 27a so as to slidably accommodate the first piston 26a in parallel with the axial direction of the brake disc 2. The first electric motor 28a is arranged radially inward of the brake disc 2 with respect to the first piston 26a.

The first linear motion mechanism 29 a has a rotation shaft 32 arranged on the center line of the piston housing hole 31. The first electric motor 28a is arranged such that the motor shaft 33 of the first electric motor 28a and the rotation shaft 32 of the first linear motion mechanism 29a are parallel to each other. The first reduction gear train 30a includes an input gear 34 to which the rotation of the first electric motor 28a is input, an output gear 35 that outputs rotation to the first linear motion mechanism 29a, and an input gear 34 and an output gear 35. And a plurality of intermediate gears 36 that transmit rotation. The first linear motion mechanism 29a converts the rotation input from the first electric motor 28a to the rotary shaft 32 via the first reduction gear train 30a into the axial movement of the first piston 26a.

The first reduction gear train 30a is housed in a gear case 37 attached to the first piston housing 27a. The gear case 37 includes a side plate 38 and a lid 39. The side plate 38 is attached to the end of the first piston housing 27a opposite to the side of the brake disc 2 in parallel with the brake disc 2. The first electric motor 28a is attached to the side plate 38.

A bolt insertion hole 40 is formed in the first piston housing 27a so as to penetrate in parallel with the axial direction of the brake disc 2. The first piston housing 27 a is fixed to the caliper body 6 by tightening the bolt 21 inserted into the bolt insertion hole 40. The first caliper arm 17 (see FIG. 1) is formed integrally with the first piston housing 27a.

As shown in FIGS. 5 and 6, the first linear motion mechanism 29a includes a plurality of planetary rollers 41 that are circumferentially spaced between the inner circumference of the first piston 26a and the outer circumference of the rotary shaft 32. And a carrier 42 that holds each planet roller 41 so that it can rotate and revolve. The first piston 26a is formed in a cylindrical shape that faces the outer circumference of the rotary shaft 32 in the radial direction.

Each planetary roller 41 is in rolling contact with the outer circumference of the rotating shaft 32. The contact portion of the rotary shaft 32 with the planetary roller 41 is a cylindrical surface. When the rotating shaft 32 rotates, each planetary roller 41 revolves around the rotating shaft 32 while revolving around the roller shaft 43, along the inner circumference of the first piston 26a.

A spiral ridge 44 is provided on the inner circumference of the first piston 26a. The spiral ridge 44 is a ridge that extends obliquely with a predetermined lead angle with respect to the circumferential direction. A plurality of circumferential grooves 45 that engage with the spiral ridges 44 are formed on the outer circumference of each planetary roller 41 at intervals in the axial direction. The interval between the circumferential grooves 45 adjacent to each other in the axial direction on the outer circumference of each planetary roller 41 has the same size as the pitch of the spiral ridges 44. Here, the circumferential groove 45 having a lead angle of 0 degrees is provided on the outer circumference of the planetary roller 41, but a spiral groove having a lead angle different from that of the spiral projection 44 may be provided instead of the circumferential groove 45. ..

The carrier 42 is provided in the center of each planet roller 41, and a pair of disks 46 and 47 axially opposed to each other with the planet roller 41 in between, a connecting portion 48 connecting the disks 46 and 47 to each other, and is rotatable about its axis. And a roller shaft 43 that supports it. Both ends of each roller shaft 43 are supported by the disks 46 and 47, respectively. Each of the disks 46 and 47 is formed in an annular shape that penetrates the rotary shaft 32, and a slide bearing 49 that is in sliding contact with the outer circumference of the rotary shaft 32 is mounted on the inner circumference thereof.

A thrust bearing 50 is incorporated between each planet roller 41 and the disk 47 to axially support the planet roller 41 in a rotatable state. Further, between the thrust bearing 50 and the disk 47, an aligning seat 51 that supports the planetary roller 41 in a tiltable manner via the thrust bearing 50 is incorporated.

Inside the piston accommodating hole 31 of the first piston housing 27a, there is a state where the rotary shaft 32 penetrates at a position separated from the side of the brake disc 2 (see FIG. 2) when viewed from the first piston 26a. A reaction force receiving member 52 formed in an annular shape is provided. A plurality of rolling bearings 53 that rotatably support the rotating shaft 32 are incorporated on the inner circumference of the reaction force receiving member 52.

A thrust bearing 54 is installed between the carrier 42 and the reaction force receiving member 52 to axially support the carrier 42 in a revolvable state. Further, a spacer 55 that revolves integrally with the carrier 42 is incorporated between the carrier 42 and the thrust bearing 54.

A boot 56 is attached to an opening edge of the piston housing hole 31 on the brake disc 2 side. The boot 56 is a tubular member that is folded in a bellows shape and is expandable and contractable in the axial direction. One end of the boot 56 is connected to the inner circumference of the piston housing hole 31, and the other end of the boot 56 is connected to the outer circumference of the first piston 26a. The boot 56 prevents foreign matter from entering between the sliding surfaces of the piston housing hole 31 and the first piston 26a.

An engaging concave portion 58 that engages with an engaging convex portion 57 formed on the back surface of the inner brake pad 3 is formed at an end portion of the first piston 26a on the side of the brake disc 2. The engaging convex portion 57 is formed. The engagement of the engagement recess 58 with the first piston 26a prevents the first piston 26a from rotating.

When the rotary shaft 32 rotates, the first linear motion mechanism 29a transmits the rotation to the planet rollers 41 that make rolling contact with the outer periphery of the rotary shaft 32, and each planet roller 41 rotates about the roller shaft 43. It revolves around the rotating shaft 32. At this time, the planetary roller 41 and the first piston 26a move relative to each other in the axial direction due to the engagement of the circumferential groove 45 on the outer circumference of the planetary roller 41 and the spiral ridge 44 on the inner circumference of the first piston 26a. Since the roller 41 and the carrier 42 are restricted from moving in the axial direction, the planetary roller 41 does not move in the axial direction with respect to the first piston housing 27a, and the first piston 26a does not move with respect to the first piston housing 27a. Move in the direction. In this way, the first linear motion mechanism 29a converts the rotation of the rotary shaft 32 into the linear motion of the first piston 26a. Similarly, the second linear motion mechanism 29b also converts the rotation transmitted from the second electric motor 28b (see FIG. 1) to the rotary shaft 32 into the linear motion of the second piston 26b (see FIG. 4).

An operation example of the electric brake device 1 will be described.

When the motor shafts 33 (see FIG. 1) of the first and second electric motors 28a and 28b rotate, the rotations of the motor shafts 33 are transmitted through the first and second reduction gear trains 30a and 30b to the first and second linear motion mechanisms 29a. , 29b (see FIG. 4) are transmitted to respective rotary shafts 32, and the rotations thereof are converted into linear motions of the first and second pistons 26a and 26b (see FIG. 4), respectively. As a result, the first and second pistons 26a and 26b press the inner side brake pad 3 at two locations spaced apart from each other in the circumferential direction of the brake disc 2, so that the inner side brake pad 3 is brought into contact with the inner side surface of the brake disc 2. Press down. At this time, the caliper body 6 slides with respect to the mounting bracket 9 by the axial reaction force that the first and second pistons 26a and 26b receive from the brake disc 2, and the pawl portion 5 of the caliper body 6 is braked to the outer side. The back surface of the pad 4 is pressed, and the outer brake pad 4 is pressed against the outer side surface of the brake disc 2. In this way, the inner brake pad 3 and the outer brake pad 4 are pressed against the brake disc 2, and the friction between the contact surfaces of the brake pads 3 and 4 and the brake disc 2 generates a braking force on the brake disc 2. To do.

Since the electric brake device 1 is configured to press the back surface of the inner side brake pad 3 at two locations that are separated from each other in the circumferential direction, even when the pressing force acting on the inner side brake pad 3 is increased, the inner side brake pad 3 is pressed. The pressure between the pad 3 and the brake disc 2 tends to be uniform over the entire surface of the inner brake pad 3. Therefore, even when a large braking force (large load) is generated, the fade phenomenon (the friction material 13 of the inner side brake pad 3 becomes high temperature and gas is generated, and the gas causes the inner side brake pad 3 and the brake disc 2 to be generated. It is possible to effectively prevent such a phenomenon that the frictional force between the inner side brake pad 3 and the inner side brake pad 3 is locally worn.

Further, in the electric brake device 1, since the first and second electric linear actuators 7a and 7b are respectively attachable to and detachable from the caliper body 6, the first and second electric linear actuators 7a and 7b are attached. By making at least one of them common with the electric linear motion actuator 7a used for manufacturing the electric brake device 60 for small loads as shown in FIGS. 7 to 9, the manufacturing cost of the electric brake device 1 is reduced. It is possible.

For example, as shown in FIGS. 7 to 9, an electric linear actuator 7a (see FIG. 10) having the same shape as the first electric linear actuator 7a shown in FIGS. 1 to 4 and the electric linear actuator. Using a small caliper body 61 for small loads to which only one 7a can be attached, the electric linear actuator 7a is attached to the caliper body 61 for small loads to manufacture an electric braking device 60 for small loads. can do. The electric brake device 60 for small loads shown in FIGS. 7 to 9 is different from the electric brake device 1 for large loads shown in FIGS. 1 to 4 only in the number of electric linear actuators. Other basic configurations are the same.

7 to 9, slide pins 63 are fixed to two first caliper arms 17 extending from the first piston housing 27a to both sides of the brake disc 62 (see FIG. 8) in the circumferential direction. Each slide pin 63 is slidably inserted into a pin hole 65 formed in a mounting bracket 64 for a small load, and the slide of the slide pin 63 causes the caliper body 61 for a small load and the first electric direct-acting unit to move. The actuator 7a is movable with respect to the mounting bracket 64 for a small load in parallel to the axial direction of the brake disc 62 for a small load.

As described above, in manufacturing the heavy-duty and small-load electric brake devices 1 and 60, the electric linear actuator 7a of the heavy-load electric brake device 1 shown in FIGS. Since the electric linear motion actuator 7a of the electric brake device 60 for small loads shown in FIG. 9 can be shared, the manufacturing cost of the electric brake devices 1, 60 for large loads and small loads can be reduced. Is possible.

Further, in the electric brake device 1 described above, since each component of the first electric linear motion actuator 7a and each component of the second electric linear motion actuator 7b have the same shape, the manufacturing cost of the electric brake device 1 is reduced. It can be effectively reduced.

Further, in the above electric brake device 1, the first caliper arm 17 on the side where the first slide pin 18 is not fixed and the second caliper arm 22 on the side where the second slide pin 23 is not fixed are in the axial direction. Since the arms 17 and 22 overlap each other, the size of the electric brake device 1 can be reduced.

In the above embodiment, an example in which the first and second caliper arms 17 and 22 for fixing the first and second slide pins 18 and 23 respectively are provided to the first and second electric linear actuators 7a and 7b is given. However, as shown in FIGS. 11 and 12, it is also possible to provide the caliper arm 66 for fixing the first and second slide pins 18, 23 on the caliper body 6 side. The electric brake device 1 shown in FIGS. 11 and 12 is different from the electric brake device 1 of the above embodiment only in the portion of the caliper arm 66, and the other parts are the same. Therefore, the electric brake device 1 of the above embodiment will be described below. The parts corresponding to are given the same reference numerals and the description thereof will be omitted.

As shown in FIGS. 11 and 12, the large-load caliper body 6 to which both the first and second electric linear motion actuators 7a and 7b can be attached is arranged in the circumferential direction of the brake disc 2 (see FIG. 2). It has two caliper arms 66 extending in parallel.

As shown in FIGS. 13 and 14, the caliper body 61 for a small load, to which only one electric linear motion actuator 7a having the same shape as the first electric linear motion actuator 7a can be attached, also includes the brake disc 62 (see FIG. 8). (See reference) has two caliper arms 67 extending parallel to the circumferential direction.

In each of the above embodiments, the first and second linear motion mechanisms 29a and 29b for converting the rotations transmitted from the first and second electric motors 28a and 28b into the linear motions of the first and second pistons 26a and 26b, respectively, Although the example in which the planetary roller mechanism that uses the planetary roller 41 is adopted has been described, other types of linear motion mechanisms (such as a feed screw mechanism and a ball ramp mechanism) may be used. Further, although the first and second electric motors 28a and 28b are arranged radially inward of the brake disc 2 with respect to the first and second pistons 26a and 26b, respectively, other positions (for example, the brakes). It may be arranged on the outer side in the radial direction of the disc 2).

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

1 Electric brake device 2 for heavy load 2 Brake disc 3 Inner side brake pad 4 Outer side brake pad 5 Claw portion 6 Heavy load caliper body 7a, 7b First and second electric linear actuator 17 First caliper arm 18 First slide pin 19 Bolt 22 Second caliper arm 23 Second slide pin 26a First piston 26b Second piston 27a First piston housing 27b Second piston housing 28a First electric motor 28b Second electric motor 29a First linear motion mechanism 29b 2nd linear motion mechanism 30a 1st reduction gear train 30b 2nd reduction gear train 60 Electric brake device for small loads 61 Caliper body 66 for small loads Caliper arm

Claims (7)

Of the pair of brake pads (3, 4) axially opposed to each other with the brake disc (2) interposed therebetween, the side surface of one brake pad (4) opposite to the side opposed to the brake disc (2). A caliper body (6) having a claw part (5) for supporting the
The side surface of the other brake pad (3) of the pair of brake pads (3, 4) opposite to the side facing the brake disk (2) is separated from the side surface in the circumferential direction of the brake disk (2). Having first and second electric linear actuators (7a, 7b) that are pressed at points,
The first and second electric linear actuators (7a, 7b) are detachably attached to the caliper body (6) ,
The first electric linear motion actuator (7a) is provided with a first piston (26a) arranged so as to face a side surface of the other brake pad (3) opposite to a side thereof facing the brake disc (2). And a first piston housing (27a) that accommodates the first piston (26a) so as to be movable parallel to the axial direction of the brake disc (2) and is detachably fixed to the caliper body (6), A first electric motor (28a) and a first electric motor (28a), which converts rotation of the first electric motor (28a) into linear motion of the first piston (26a) and is housed in the first piston housing (27a). 1 linear motion mechanism (29a),
The second electric linear motion actuator (7b) is located at a position distant from the first piston (26a) in the circumferential direction of the brake disc (2), and the brake disc (3) of the other brake pad (3). 2) A second piston (26b) arranged opposite to the side surface opposite to the side opposite to 2), and the second piston (26b) can be moved in parallel with the axial direction of the brake disc (2). A second piston housing (27b) which is housed and formed separately from the first piston housing (27a) and is detachably fixed to the caliper body (6); and a second electric motor (28b). The rotation of the second electric motor (28b) is converted into the linear movement of the second piston (26b), and the second linear motion mechanism (29b) housed in the second piston housing (27b) is provided. Have,
Electric brake device. The first and second pistons (26a, 26b) have the same shape,
The first and second piston housings (27a, 27b) have the same shape,
The first and second electric motors (28a, 28b) have the same shape,
The first and second linear motion mechanisms (29a, 29b) have the same shape,
The electric brake device according to claim 1. The first electric linear motion actuator (7a) has two first caliper arms (17) extending on both sides in the circumferential direction of the brake disc (2), and the two first caliper arms (17). ), a first slide pin (18) that movably supports the caliper body (6) in parallel with the axial direction of the brake disc (2) is fixed,
The second electric linear motion actuator (7b) has two second caliper arms (22) extending on both sides in the circumferential direction of the brake disc (2), and the two second caliper arms (22). ), a second slide pin (23) for movably supporting the caliper body (6) in parallel with the axial direction of the brake disc (2) is fixed.
The electric brake device according to claim 1. Of the two first caliper arms (17), the first caliper arm (17) on the side where the first slide pin (18) is not fixed is fixed to the caliper body (6),
Of the two second caliper arms (22), the second caliper arm (22) on the side where the second slide pin (23) is not fixed is fixed to the caliper body (6).
The electric brake device according to claim 3. The two first caliper arms (17) are axially displaced from each other,
The two second caliper arms (22) are axially displaced from each other,
Of the two first caliper arms (17), the first caliper arm (17) on the side where the first slide pin (18) is not fixed and the two second caliper arms (22) The second slide pin (23) is fixed to the caliper body (6) with a common bolt (19) in a state where the second slide pin (23) and the second caliper arm (22) on the non-fixed side are overlapped in the axial direction. ing,
The electric brake device according to claim 3 or 4. The caliper body (6) has two caliper arms (66) extending parallel to the circumferential direction of the brake disc (2), and the caliper body (6) is attached to the two caliper arms (66). Slide pins (18, 23) for movably supporting the brake disc (2) parallel to the axial direction are fixed, respectively.
The electric brake device according to claim 1. Of the pair of brake pads (3, 4) axially opposed to each other with the brake disc (2) interposed therebetween, the side surface of one brake pad (4) opposite to the side opposed to the brake disc (2). A heavy-duty caliper body (6) having a claw portion (5) for supporting the
The side surface of the other brake pad (3) of the pair of brake pads (3, 4) opposite to the side facing the brake disk (2) is separated from the side surface in the circumferential direction of the brake disk (2). Using the first and second electric linear actuators (7a, 7b) that press at points,
An electric brake device (1) for heavy load is manufactured by detachably attaching the first and second electric linear motion actuators (7a, 7b) to the heavy caliper body (6). ,
A caliper body (61) for small load, which is smaller than the caliper body (6),
At least one of the first and second electric linear actuators (7a, 7b) and an electric linear actuator (7a) having the same shape are used,
An electric brake device (60) for small load is manufactured by detachably attaching the electric linear actuator (7a) of the same shape to the caliper body (61) for small load.
Electric brake device manufacturing method.

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