WO2015019748A1 - Friction brake device - Google Patents

Abstract

A friction brake device (10) comprises: a brake rotor (12); brake pads (14A, 14B) that rotate around an axis of rotation (36) that is parallel to the axis of rotation (18) of the friction brake device; rotating torque transmission devices (80A, 80B) that transmit rotating torque between the brake rotor and the brake pads; and a pressing device (54) that presses pressing members (34A, 34B) against the brake pads, and presses the brake pads against the brake rotor. Furthermore, the friction brake device has rotating torque-pressing force conversion mechanisms (42A, 42B, 82A, 82B) that transmit the rotating torque of the brake pads to the pressing members, and convert the rotating torque of the pressing members to a pressing force with which the pressing members press the brake pads.

Description

Friction brake device

The present invention relates to a friction brake device, and more particularly to a friction brake device that generates a frictional force by pressing a friction member against a brake rotor.

As one of the friction brake devices, for example, as described in the following Patent Document 1 applied to the applicant of the present application, the friction brake device has a friction member that is pressed against the rotor disk via the pressing member, and the friction member is the rotor disk. There is already known a brake device that can rotate around a rotation axis parallel to the rotation axis. In this type of disc type brake device, the friction member revolves around the rotation axis relative to the rotor disc, so that a braking torque is generated, and the rotation around the rotation axis relative to the rotor disc occurs. As a result, drag torque is generated. The braking torque is also generated when the drag torque is transmitted to the rotor disk by the gear device.

According to the brake device described in Patent Document 1, the braking force is increased as compared with a general brake device in which braking torque is generated only when the friction member revolves relative to the rotor disk. be able to. In this case, the braking force can be increased without increasing the pressing force with which the pressing device presses the friction member against the rotor disk via the pressing member.

JP 2008-151199 A

[Problems to be Solved by the Invention]
However, in the friction brake device described in the above publication, since the pressing force by which the pressing member presses the friction member against the rotor disk is not increased, it is the same as the pressing force by which the pressing device presses the pressing member against the friction member. It is. For this reason, there is a limit to increasing the braking force without increasing the pressing force of the pressing device, and there is room for improvement in further increasing the braking force.

The present invention has been made in view of the above-described limitations in a friction brake device having a friction member capable of rotating and a transmission device for transmitting rotational torque between the brake rotor and the friction member. The main object of the present invention is to increase the pressing force by which the pressing member presses the friction member against the rotor disk without effectively increasing the pressing force of the pressing device by effectively using the rotational torque of the friction member. It is.

[Means for Solving the Problems and Effects of the Invention]
According to the present invention, the rotational torque is mutually exchanged between the brake rotor rotating around the rotation axis, the rotary friction member rotatable around the rotation axis parallel to the rotation axis, and the brake rotor and the rotation friction member. In the friction brake device having a rotational torque transmission device that transmits to the brake friction member and a pressing device that presses the rotational friction member against the brake rotor by pressing the pressing member against the rotational friction member, the rotational torque of the rotational friction member Is provided to the pressing member, and there is provided a friction brake device having a rotational torque-pressing force conversion mechanism for converting the rotational torque of the pressing member into a pressing force by which the pressing member presses the rotating friction member. The

According to this configuration, the rotational torque of the brake rotor is transmitted to the rotational friction member by the rotational torque transmission device. The rotational torque-pressing force conversion mechanism transmits the rotational torque of the rotational friction member to the pressing member, and the rotational torque of the pressing member is converted into a pressing force that presses the rotational friction member by the pressing member. Therefore, the pressing force by which the pressing member presses the rotating friction member against the rotor disk can be increased by effectively using the rotational torque transmitted from the brake rotor to the friction member.

Therefore, even if the pressing device does not increase the pressing force that presses the rotating friction member against the brake rotor via the pressing member, the rotating friction member is revolved and rotated as compared with the friction brake device described in the above publication. The braking force generated by the rotation can be further increased.

According to the invention, in the above configuration, the pressing member supports the rotating friction member rotatably around the rotation axis, and is supported rotatably around the rotation axis by the stationary support member. The torque-pressing force conversion mechanism is disposed between the rotational friction member and the stationary support member, and transmits the rotational torque from the rotational friction member to the pressing member, and the pressure against the stationary support member around the rotation axis. A rotation-linear displacement conversion mechanism that converts the relative rotation of the member into a linear displacement of the pressing member toward the brake rotor along the rotation axis.

According to this configuration, the rotational torque is transmitted from the rotational friction member to the pressing member by the rotational torque transmission member. Further, the rotation-linear displacement converting mechanism converts the relative rotation of the pressing member with respect to the stationary support member around the rotation axis into linear displacement of the pressing member toward the brake rotor along the rotation axis. Therefore, since the rotating friction member can be moved in the direction toward the brake rotor along the rotation axis by the pressing member, the pressing force with which the rotating friction member presses the rotor disk can be increased.

Further, according to the present invention, the rotation-linear displacement conversion mechanism may be a screw-type rotation-linear displacement conversion mechanism provided with a guide groove extending spirally around the rotation axis.

According to this configuration, the rotation-linear displacement conversion mechanism is a screw-type rotation-linear displacement conversion mechanism provided with a guide groove extending spirally around the rotation axis. Therefore, the rotational movement of the pressing member can be converted into a linear movement of the pressing member toward the brake rotor along the rotation axis by the screw action by the guide groove.

According to the present invention, in the configuration described above, the rotation-linear displacement conversion mechanism is an inclined surface of the pressing member and the stationary support member facing each other along the rotation axis, and is relative to a virtual plane perpendicular to the rotation axis. It may be a wedge type rotation-linear displacement conversion mechanism having an inclined surface inclined in the same direction and extending in an arc shape around the rotation axis.

According to this configuration, the rotation-linear displacement conversion mechanism is an inclined surface of the pressing member and the stationary support member, and is inclined in the same direction with respect to a virtual plane perpendicular to the rotation axis, and is arcuate around the rotation axis. This is a wedge-type rotation-linear displacement conversion mechanism having an inclined surface extending in the direction. Therefore, by the wedge action by the inclined surfaces of the pressing member and the stationary support member, the rotational movement of the pressing member can be converted into a linear movement of the pressing member toward the brake rotor along the rotation axis.

Further, according to the present invention, in the above configuration, each inclined surface may have a region inclined in the opposite direction to the virtual plane.

According to this configuration, since each inclined surface has regions inclined in opposite directions with respect to the virtual plane, the rotating friction member is braked along the rotation axis by the pressing member regardless of the rotation direction of the pressing member. It can be moved in the direction toward the rotor. Therefore, regardless of the rotation direction of the rotor disk, it is possible to increase the pressing force with which the rotating friction member presses the rotor disk. Therefore, when the brake device of the present invention is applied to a vehicle brake device, a high braking force can be generated with high responsiveness regardless of whether the vehicle is moving forward or backward.

According to the present invention, in the above configuration, the rotational friction member has a shaft portion extending coaxially with the rotation axis, and the rotational torque transmission member is an elastically deformable region along the rotation axis. When the amount of compressive deformation in the region exceeds the reference value, the rotational torque transmitted by the rotational torque transmitting member is engaged with the pressing member on the rotation axis. A rotational torque transmission limiting mechanism that prevents the torque from increasing may be formed.

According to this configuration, when the amount of compressive deformation in the elastically deformable region exceeds the reference value, the shaft portion of the rotating friction member engages with the pressing member on the rotation axis, so that the rotational torque transmitting member The rotational torque transmitted by is prevented from increasing. Further, when the rotational torque of the rotational friction member is the same, the rotational torque transmitted to the pressing member by the rotational torque transmitting member changes according to the pressing force of the pressing device that presses the pressing member against the rotational friction member. To do.

Therefore, the rotational torque transmission limiting mechanism can reliably prevent the rotational torque of the pressing member from being converted into a pressing force that presses the rotational friction member without limit. In addition, it is possible to increase the pressing force according to the pressing force of the pressing device, and it is possible to reliably prevent the pressing force from increasing without limit.

According to the invention, in the above configuration, the rotational torque transmitting member extends along the rotation axis while being fitted to the shaft portion, and is supported at one end by one of the rotational friction member and the stationary support member. The other end of the rotary friction member and the stationary support member may be frictionally engageable over the entire circumference.

According to this configuration, for example, the rotational torque is more favorably transmitted from the rotational friction member to the pressing member than when the rotational torque transmission member is provided only in a partial region around the rotation axis. be able to. Further, for example, compared with the case where the other end of the rotational torque transmitting member can be frictionally engaged with the other of the rotational friction member and the stationary support member only in a partial region around the rotation axis, the rotational friction member is applied to the pressing member. Rotational torque can be transmitted satisfactorily. Further, it is possible to reduce the possibility of abnormal wear such as uneven wear occurring on the other of the rotary friction member and the stationary support member that frictionally engage with the other end of the rotational torque transmission member, and improve the durability of the brake device. .

Further, according to the present invention, in the above configuration, the rotational torque transmission device may include a gear provided on the brake rotor and the rotational friction member and meshing with each other.

According to this configuration, the rotational torque is transmitted between the brake rotor and the rotational friction member by the rotational torque transmission device including the gears meshing with each other. Therefore, the rotational friction member can be reliably rotated around the rotation axis by the rotation torque of the brake rotor, and the drag torque generated by the rotation of the rotation friction member can be reliably converted into the braking torque and transmitted to the brake rotor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a first embodiment of a friction brake device according to the present invention configured as a vehicle brake device, cut along a cut surface passing through a rotation axis. It is sectional drawing which cuts and shows 2nd embodiment of the friction brake device by this invention comprised as a brake device for vehicles by the cut surface which passes along a rotating shaft line. It is sectional drawing which cut | disconnects and shows 3rd embodiment of the friction brake device by this invention comprised as a brake device for vehicles by the cut surface which passes along a rotating shaft line. FIG. 4 is a partial cross-sectional view showing the wedge-type rotational torque-pressing force conversion mechanism shown in FIG. 3 cut along a cylindrical cut surface extending around a rotation axis. FIG. 6 is a partial cross-sectional view showing a wedge-type rotational torque-pressing force conversion mechanism when a pressing member and a supporting member are relatively displaced. FIG. 5 is a partial cross-sectional view showing one modified example of a cam surface of a wedge-type rotational torque-pressing force conversion mechanism. FIG. 6 is a partial cross-sectional view showing another modification of the cam surface of the wedge-type rotational torque-pressing force conversion mechanism.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

[First embodiment]
FIG. 1 is a cross-sectional view showing a first embodiment of a friction brake device according to the present invention configured as a vehicle brake device, cut along a cut surface passing through a rotation axis.

In FIG. 1, reference numeral 10 denotes an overall brake device, and the brake device 10 includes a brake rotor 12 and brake pads 14A and 14B as first and second rotating friction members. The brake rotor 12 rotates about a rotation axis 18 together with a rotation axis 16 of a wheel (not shown). In particular, in the illustrated embodiment, the brake rotor 12 includes a main rotor 20 that is integral with the rotary shaft 16 and a sub-rotor 22 that rotates integrally with the main rotor. The main rotor 20 and the sub rotor 22 are formed of the same metal material.

The main rotor 20 has a disk portion 20A and a cylindrical portion 20B that are spaced apart from each other along the rotation axis 18. The disk portion 20 </ b> A is integrally connected to the rotation shaft 16 at the inner peripheral portion, and extends substantially in a disk shape around the rotation axis 18 perpendicular to the rotation axis 18. The cylindrical portion 20B is integrally connected to the outer peripheral portion of the disk portion 20A and extends in a cylindrical shape around the rotation axis 18. The sub-rotor 22 extends in the shape of an annular plate around the rotation axis 18 perpendicular to the rotation axis 18, and is connected to the end of the cylindrical portion 20B opposite to the disk portion 20A by a plurality of bolts 24 at the outer periphery. Has been.

The disk portion 20A and the sub-rotor 22 have the same thickness, and the thickness of the cylindrical portion 20B is smaller than the thickness of the disk portion 20A and the sub-rotor 22. However, since the cylindrical portion 20 </ b> B extends in a cylindrical shape around the rotation axis 18, it has higher rigidity than the disk portion 20 </ b> A and the sub-rotor 22.

Thus, the disk portion 20 </ b> A and the sub-rotor 22 function as first and second disk portions extending around the rotation axis 18 perpendicular to the rotation axis 18 and spaced apart from each other along the rotation axis 18. The cylindrical portion 20 </ b> B functions as a connecting portion that cooperates with the bolt 24 to integrally connect the outer peripheral portion of the disk portion 20 </ b> A and the sub-rotor 22. The disk portion 20A, the cylindrical portion 20B, and the sub-rotor 22 have a U-shaped cross-sectional shape opened inward in the radial direction when viewed from a radial cut surface passing through the rotation axis 18. The mutually opposed surfaces of the disk portion 20A and the sub-rotor 22 define first and second friction surfaces extending around the rotation axis 18 in parallel to each other perpendicular to the rotation axis 18 respectively. .

The rotary shaft 16 is rotatably supported around the rotary axis 18 by a sleeve portion 28A of a wheel support member 28 via a pair of ball bearings 26. A space between the pair of ball bearings 26, the rotating shaft 16, and the sleeve portion 28A is filled with a lubricant such as grease. A pair of seal members 30 are arranged on both sides in the axial direction with respect to the pair of ball bearings 26. The seal member 30 is disposed between the rotary shaft 16 and the sleeve portion 28A so that dust and muddy water do not enter the ball bearing 26. It is sealed.

Although not shown in the drawing, the disk portion 20A of the main rotor 20 is a wheel rim formed by four bolts 32 and nuts screwed to the four bolts 32 while being spaced apart from each other by 90 ° around the rotation axis 18. It is designed to be integrally connected to the part. Therefore, the rotating shaft 16 and the brake rotor 12 (the main rotor 20 and the sub-rotor 22) rotate around the rotating axis 18 together with the wheels.

The brake pads 14A and 14B are disposed between the disc portion 20A and the sub-rotor 22, and have the same shape and size. Each of the brake pads 14A and 14B has a disc portion and a shaft portion that are coaxial with each other, and the disc portion is located on the side of the disc portion 20A and the sub-rotor 22. The disc portion of the brake pad 14A has a friction portion 14AA on the outer peripheral portion of the outer surface, and the disc portion of the brake pad 14B has a friction portion 14BA on the outer peripheral portion of the outer surface. Each friction part extends in the form of a ring around the axis of the brake pad in a state of protruding from the side surface of the disk part.

The brake pads 14A and 14B may be formed integrally with the disc portion by being manufactured by, for example, a powder sintering method. Further, the friction part may be formed by attaching an annular belt-like friction material to the side surface of the disk part by bonding or other means. Furthermore, although the friction portions 14AA and 14BA are made of the same friction material, they may be made of different friction materials.

The brake pads 14A and 14B can be rotated around a rotation axis 36 parallel to the rotation axis 18 by pressing members 34A and 34B, respectively, and can be relatively displaced along the rotation axis 36 with respect to the pressing members 34A and 34B. Is supported. The pressing members 34A and 34B each have a cylindrical portion surrounding the shaft portions of the brake pads 14A and 14B, a shaft portion formed integrally with the cylindrical portion, and a disk portion connecting them integrally. Yes. The tip ends of the shaft portions of the brake pads 14A and 14B have a spherical shape, and are slightly spaced apart from the pressing members 34A and 34B, respectively. A plurality of balls 38A and 38B are interposed between the shaft portions of the brake pads 14A and 14B and the cylindrical portions of the pressing members 34A and 34B, respectively.

The pressing members 34A and 34B are supported by the support members 40A and 40B, respectively, so that they can rotate around the rotation axis 36 and can be displaced relative to the support members 40A and 40B along the rotation axis 36. Yes. The support members 40 </ b> A and 40 </ b> B each have an outer cylindrical portion and an inner cylindrical portion that are integral with each other, and these cylindrical portions are aligned with the rotation axis 18. The outer cylindrical portions of the support members 40A and 40B support the cylindrical portions of the pressing members 34A and 34B via the ball screw mechanisms 42A and 42B, respectively, and the inner cylindrical portions of the support members 40A and 40B are respectively pressed members 34A and 34B. The shaft part is directly supported.

The ball screw mechanism 42A includes screw grooves provided on the outer surface of the cylindrical portion of the pressing member 34A and the inner surface of the outer cylindrical portion of the support member 40A, and a plurality of balls 48A that are partially engaged in these screw grooves. Is included. Similarly, the ball screw mechanism 42B includes a plurality of screw grooves provided on the outer surface of the cylindrical portion of the pressing member 34B and the inner surface of the outer cylindrical portion of the support member 40B, and a plurality of portions that are partially engaged with these screw grooves. Ball 48B. Each thread groove extends spirally around the rotation axis 36.

Support members 40A and 40B are supported by stationary member 50 in a state where their inner ends are in contact with each other. In particular, in the illustrated embodiment, the stationary member 50 has a cylindrical portion 50X extending along the rotation axis 36, and the support members 40A and 40B are fixed to the cylindrical portion 50X by press-fitting. Therefore, the support members 40 </ b> A and 40 </ b> B do not rotate around the rotation axis 36 relative to the stationary member 50, and are not displaced along the rotation axis 36 relative to the stationary member 50. Accordingly, the support members 40A and 40B and the stationary member 50 work together to function as a stationary support member. The stationary member 50 has a cylindrical inner peripheral portion 50Y, and the cylindrical portion 50X is integrally connected to the inner peripheral portion 50Y by an annular plate-like portion 50Z extending around the rotational axis 18 perpendicular to the rotational axis 18. Has been.

The shaft portions of the brake pads 14A and 14B and the inner cylindrical portions of the support members 40A and 40B cooperate with each other to form a piston-cylinder device 54 having a cylinder chamber 52. Between the inner ends of the support members 40A and 40B, a plurality of radial passages 56 are formed by a plurality of radial grooves provided at the inner ends. Around the inner ends of the support members 40A and 40B, an annular passage 58 extending around the rotation axis 36 in cooperation with the cylindrical portion 50X of the stationary member 50 is formed.

In FIG. 1, only one each of the brake pads 14A and 14B, the pressing members 34A and 34B, the support members 40A and 40B, the cylindrical portion 50X, the piston-cylinder device 54, etc. is shown. However, a plurality of these may be provided in a state of being evenly spaced around the rotation axis 18.

A radial passage 60 communicating with the annular passage 58 at the radially outer end is formed inside the cylindrical portion 50X and the annular plate-like portion 50Z of the stationary member 50. An annular groove 62 extending around the rotation axis 18 is formed on the inner surface of the inner peripheral portion 50 </ b> Y of the stationary member 50, and the annular groove 62 communicates with the radially inner end of the radial passage 60. ing. The annular groove 62 is connected to a hydraulic brake actuator by a communication hole 64 provided in the inner peripheral portion 50Y of the stationary member 50 and a conduit (not shown).

The regions between the shaft portions of the pressing members 34A and 34B and the inner cylindrical portions of the support members 40A and 40B are sealed by O- ring seals 66A and 66B on both sides of the cylinder chamber 52. The regions between the outer cylindrical portions of the support members 40A and 40B and the cylindrical portion 50X of the stationary member 50 are sealed by O- ring seals 68A and 68B on both sides of the annular passage 58. Further, regions between the sleeve portion 28A of the wheel support member 28 and the inner peripheral portion 50Y of the stationary member 50 on both sides of the annular groove 62 are sealed by O- ring seals 70A and 70B.

Further, a cover member 72 is fixed to the side surface of the annular plate-like portion 50Z of the stationary member 50 by screwing. The cover member 72 covers the sub-rotor in a state of being separated from the sub-rotor 22, and prevents dust and muddy water from entering the brake device 10 between the brake rotor 12 and the stationary member 50.

External gears 76A and 76B are provided on the outer peripheries of the disc parts of the brake pads 14A and 14B, respectively, and the external gears 76A and 76B mesh with internal gears 78A and 78B provided on the cylindrical part 20B of the main rotor 20, respectively. is doing. The external gears 76A and 76B and the internal gears 78A and 78B are not dependent on the frictional force between the brake rotor 12 and the brake pads 14A and 14B, and the rotational torque transmission device 80A and It functions as 80B.

The shaft portions of the brake pads 14A and 14B have a large-diameter portion on the base side and a small-diameter portion on the tip side, and rotational torque transmitting members 82A and 82B are fitted in the small-diameter portions, respectively. The rotational torque transmitting members 82A and 82B fulfill the function of transmitting rotational torque around the rotation axis 36 between the brake pads 14A and 14B and the pressing members 34A and 34B, respectively, as necessary.

The rotational torque transmitting members 82A and 82B are made of an elastic cylinder made of an elastic material such as hard rubber having a high elastic modulus, and are disposed closer to the cylinder chamber 52 than the elastic cylinder and are substantially rigid bodies such as metal. And a hard cylindrical body formed by The elastic cylinder and the hard cylinder are integrally connected by means such as adhesion at the inner end and the outer end, respectively. The outer end of the elastic cylinder is fixed to the shoulder between the large-diameter portion and the small-diameter portion by means such as adhesion, and the inner end of the hard cylinder can be frictionally engaged with the pressing members 34A and 34B. It has become.

When the rotational torque of the brake pads 14A and 14B is transmitted to the pressing members 34A and 34B by the rotational torque transmitting members 82A and 82B, these pressing members are rotated around the rotation axis 36 relative to the support members 40A and 40B. Rotate to. The twist direction of each screw groove of the ball screw mechanisms 42A and 42B is such that the pressing members 34A and 34B are rotated around the rotation axis 36 and displaced toward the brake pads 14A and 14B when the vehicle moves forward. Is set.

Therefore, when the brake pads 14A and 14B rotate, the pressing members 34A and 34B are displaced in a direction approaching the brake pads 14A and 14B, and the pressing members press the brake pads via the rotational torque transmission members 82A and 82B. Therefore, the ball screw mechanisms 42A and 42B and the rotational torque transmission members 82A and 82B cooperate with the pressing members 34A and 34B and the support members 40A and 40B, and use the rotational torque of the brake pads 14A and 14B as the pressing force of the pressing members. Functions as a conversion mechanism for conversion.

The length of the rotational torque transmitting members 82A and 82B in the free state is the length of the small diameter portion of the shaft portion of the brake pads 14A and 14B, that is, the length from the shoulder portion to the tip end between the large diameter portion and the small diameter portion. Too long. However, when the rotational torque transmitting member receives a compressive stress in the longitudinal direction, the intermediate cylindrical body is compressed and deformed, so that the length of the rotating torque transmitting member can be reduced to the length of the small diameter portion of the shaft portion. Accordingly, the rotational torque transmitting members 82A and 82B are subjected to compressive stress in the longitudinal direction, and in a situation where their length is greater than the length of the small diameter portion of the shaft portion, Rotational torque is transmitted to The rotational torque transmitted is proportional to the frictional force between the inner end of the hard cylindrical body and the pressing members 34A and 34B, and is therefore proportional to the compressive stress received by the rotational torque transmitting member.

However, when the compressive stress received by the rotational torque transmitting member further increases and the tips of the shaft portions of the brake pads 14A and 14B abut against the pressing members 34A and 34B, respectively, the compressive stress received by the rotational torque transmitting member further increases. Disappear. Therefore, in this situation, even if the pressing force by which the pressing members 34A and 34B press the shaft portions of the brake pads 14A and 14B is increased, the rotational torque transmitted between the brake pad and the pressing member does not increase. Accordingly, the shaft portions of the brake pads 14A and 14B and the rotational torque transmission members 82A and 82B cooperate with each other to limit the rotational torque transmission between the brake pads 14A and 14B and the pressing members 34A and 34B. Functions as limiting mechanisms 84A and 84B.

As understood from the above description, when the hydraulic pressure in the cylinder chamber 52 of the piston-cylinder device 54 is increased, the brake pads 14A and 14B and the pressing members 34A and 34B are driven in directions away from each other. As a result, the brake pads 14A and 14B are pressed against the friction surfaces of the disk portion 20A and the sub-rotor 22, respectively. Therefore, the piston-cylinder device 54 is supported by the stationary member 50, and serves as first and second pressing devices that press the brake pads 14A and 14B against the disk portion 20A and the sub-rotor 22 via the pressing members 34A and 34B, respectively. Function.

When a wheel (not shown) rotates, the brake rotor 12 and the rotating shaft 16 rotate around the rotating axis 18 together with the wheel. However, the brake pads 14A and 14B, the sleeve portion 28, the support members 40A and 40B, the stationary member 50, and the cover member 72 do not rotate around the rotation axis 18. Therefore, the disk portion 20A and the sub-rotor 22 rotate around the rotation axis 18 relative to the brake pads 14A and 14B. Further, the rotational torques of the disk portion 20A and the sub-rotor 22 are converted into rotational torque around the rotation axis 36 by the rotational torque transmission devices 80A and 80B, respectively, and transmitted to the brake pads 14A and 14B. Accordingly, the brake pads 14A and 14B revolve around the rotation axis 18 relative to the disk portion 20A and the sub-rotor 22 while rotating around the rotation axis 36, and rotate relatively to the pressing members 34A and 34B. Rotates about axis 36.

When the brake pads 14A and 14B are pressed by the pressing members 34A and 34B, the friction portions of the brake pads 14A and 14B are frictionally engaged with the disc portion 20A and the sub-rotor 22, respectively, and a friction force is generated. Therefore, in addition to the braking torque Trv due to the revolution of the brake pads 14A and 14B, the braking torque Trt due to the rotation is generated, and the sum of these becomes the braking torque Tb.

The braking torques Trv and Trt are proportional to the pressing force of the brake pads 14A and 14B against the disc portion 20A and the sub-rotor 22. These pressing forces are increased by a rotational torque-pressing force conversion mechanism using ball screw mechanisms 42A, 42B, etc., and these pressing forces are proportional to the hydraulic pressure in the cylinder chamber 52 of the piston-cylinder device 54. Therefore, by controlling the pressing force by controlling the hydraulic pressure in the cylinder chamber 52, the braking torque Tb, that is, the braking force generated by the brake device 10 can be controlled.

As described above, the braking torque Tb is the sum of the braking torque Trv due to revolution and the braking torque Trt due to rotation. Further, the pressing force of the brake pads 14A and 14B against the disc portion 20A and the sub-rotor 22 is increased by a rotational torque-pressing force conversion mechanism such as a ball screw mechanism 42A or 42B. The rotational torque is derived from the rotational torque transmitted from the disk portion 20A and the sub-rotor 22 to the brake pads 14A and 14B via the rotational torque transmission devices 80A and 80B, that is, the rotational torque of the wheels.

Therefore, according to the first embodiment, it is possible to generate a braking torque far higher than that of a conventional brake device having a general structure that generates only the braking torque Trv, and the rotational torque is converted into a pressing force. Therefore, it is possible to generate a higher braking torque than that of the brake device described in the above-mentioned publication in which the pressing force is not increased.

For example, although not shown in FIG. 1, the distance between the rotation axis 18 and the rotation torque transmission devices 80A and 80B is 152.5 mm, the distance between the rotation axis 18 and the rotation axis 36 is 120 mm, and the rotation axis 36 The distance from the center of the friction portions 14AA and 14BA is 25 mm. Further, the friction coefficient of each friction contact portion is μ, the pressing force by the piston-cylinder device 54 as the pressing device is F1 kgf, and the pressing force after the increase due to the rotation torque being converted into the pressing force is F2 kgf.

The drag torque Tst around the rotation axis 36 generated by the rotation of the brake pads 14A and 14B is the sum of the drag torque generated by the rotation of the two brake pads, and is expressed by the following formula 1.
Tst = 2 × 25 × μ × F2
= 50μF2 (1)

The drag torque Tst is converted into a rotational torque in the braking direction around the rotational axis 18 by the rotational torque transmission devices 80A and 80B, and transmitted to the brake rotor 12 as a braking torque Trt by rotation. Since the distance between the rotation axis 36 and the rotational torque transmission devices 80A and 80B is 32.5 mm, the braking torque Trt due to the rotation is expressed by the following equation (2).
Trt = 50 μF2 / 32.5 × 152.5
= 234μF2 (2)

Further, it is considered that the braking torque Trv due to revolution is generated by the frictional force generated when the brake pads 14A and 14B are pressed against the disk portion 20A and the sub-rotor 22 by the pressing force F2 acting along the rotation axis 36. Good. Therefore, the braking torque Trv is expressed by the following formula 3.
Trv = 2 × 120μF2
= 240μF2 (3)

Therefore, the braking torque Tb, which is the sum of the braking torque Trv and the braking torque Trt due to rotation, is expressed by the following Equation 4, and is compared with a brake device having a conventional general structure that generates only the braking torque Trv. The servo ratio Rbt1 of the braking torque is expressed by the following formula 5.
Tb = 234μF2 + 240μF2
= 474μF2 (4)
Rbt1 = 474μF2 / 240μF2
= 1.975 (5)

Further, the lead angle of the thread groove of the ball screw mechanisms 42A and 42B is set to 14 degrees, the efficiency for converting the rotational torque into the pressing force is set to 100%, and the distance between the rotation axis 36 and the centers of the balls 48A and 48B is set to 18 mm. The friction coefficient μ2 between the rotational torque transmission members 82A and 82B and the pressing members 34A and 34B is set to 0.6, and the distance from the rotation axis 36 to the thickness center of the rotational torque transmission members 82A and 82B is 6 mm.

The servo force F3 generated by converting the rotational torque into the pressing force is expressed by the following equation (6). Further, since the pressing force F1 is F2-F3, the servo ratio Rbt2 of the increase due to the rotation torque being converted into the pressing force is expressed by the following equation (7).
F3 = F2 × 0.6 × 6/18 / tan14
= F2 x 0.802 (6)
Rbt2 = F2 / F1
= {1 / (1-0.802)}
= 5.05 (7)

Therefore, the servo ratio of the braking torque in comparison with a conventional general brake device in which the brake pad does not rotate is Rbt1 × Rbt2 = 9.98. Further, the servo ratio of the braking torque in comparison with the brake device described in the above-mentioned publication in which the brake pad rotates is Rbt2, that is, 5.05. Therefore, according to the first embodiment, in the case of the above specifications, it is possible to generate a braking torque about 10 times that of a brake device having a conventional general structure, and is described in the above-mentioned publication. A braking torque about 5 times that of the braking device can be generated.

In this embodiment, when N (positive integer) brake pads are provided around the rotation axis 18, the braking torque Tb is N times the value expressed by Equation 5. Therefore, a higher braking torque can be generated, and both of the servo ratios Rbt1 and Rbt2 can be further increased.

Further, as the pressing force by the piston-cylinder device 54 increases, the amount of compressive deformation of the rotational torque transmitting members 82A and 82B increases. Therefore, when the pressing force by the piston-cylinder device 54 exceeds a certain value, the tip ends of the shaft portions of the brake pads 14A and 14B come into contact with the pressing members 34A and 34B at the position of the rotation axis 36. Therefore, since the rotational torque transmitted from the brake pad to the pressing member does not increase any more, the servo ratio of the braking torque in that situation is Rbt1.

Further, when the vehicle is moving backward, the pressing members 34A and 34B have a function of converting the rotational torque into the pressing force by the ball screw mechanisms 42A and 42B so as to reduce the pressing force of the brake pads 14A and 14B on the disc portion 20A and the sub-rotor 22. Works. However, as described above, when the pressing force by the piston-cylinder device 54 exceeds a certain value, the tip ends of the shaft portions of the brake pads 14A and 14B abut against the pressing members 34A and 34B, and are transmitted from the brake pad to the pressing member. The rotational torque does not increase any further. Therefore, although the responsiveness of the generation of the braking force is somewhat lower than when the vehicle moves forward, the braking force can be generated according to the braking operation even when the vehicle moves backward. Also in this case, the servo effect by the rotation of the brake pads 14A and 14B can be obtained.

[Second Embodiment]
FIG. 2 is a cross-sectional view showing a second embodiment of the friction brake device according to the present invention configured as a vehicle brake device, cut along a cut surface passing through the rotation axis. In FIG. 2, the same members as those shown in FIG. 1 are denoted by the same reference numerals as those in FIG. The same applies to FIG. 3 described later.

In the second embodiment, the main rotor 20 does not have the cylindrical portion 20B and is a member different from the rotating shaft 16. Further, the annular plate-like disk portion 20A of the main rotor 20 is integrally connected to the sub-rotor 22 by a connection portion 64 made of fins for heat dissipation. The rotary shaft 16 has a flange portion 16A at an outer end portion, and the inner peripheral portion of a rim portion 20C integrated with the disc portion 20A is connected to the flange portion 16A by four bolts 32. Accordingly, although not shown in the drawing, the bolt 32 and the nut screwed to the bolt 32 integrally connect the rim portion 20C to the disc portion of the wheel together with the flange portion 16A.

The brake pads 14A and 14B, the pressing members 34A and 34B, and the support members 40A and 40B are disposed on both sides of the brake rotor 12 in the opposite direction to the case of the first embodiment. Therefore, the disc portions of the brake pads 14A and 14B are located on the disk portion 20A and the sub-rotor 22 side, and the shaft portions extend away from the disc portion. Further, the support members 40A and 40B are displaced relative to the caliper along the rotation axis 36 by the caliper 88 extending substantially in a U-shaped cross section across the outer periphery of the brake rotor 12 and around the rotation axis 36. It is supported so as not to rotate.

The caliper 88 is composed of half bodies 88A and 88B integrally connected by connecting means such as bolts or welding, and the half body 88B is integrally fixed to the stationary member 50 by connecting means such as bolts. Half bodies 88A and 88B cooperate with pressing members 34A and 34B and support members 40A and 40B, respectively, to form piston- cylinder devices 54A and 54B having cylinder chambers 52A and 52B. The piston- cylinder devices 54A and 54B form a pressing device that presses the brake pads 14A and 14B against the disk portion 20A and the sub-rotor 22 via the pressing members 34A and 34B, respectively.

Although not shown in FIG. 2, the cylinder chambers 52A and 52B are connected to a hydraulic brake actuator by internal passages provided in the half bodies 88A and 88B and conduits communicating therewith, respectively. Accordingly, the hydraulic pressure in the cylinder chambers 52A and 52B is simultaneously controlled to the same pressure by the brake actuator.

A ring gear member 90 having a substantially cylindrical shape is fixed to the outer periphery of the main rotor 20 by means such as welding, and the ring gear member 90 extends around the rotation axis 18. Internal gears 78A and 78B are provided on the inner surfaces of both ends of the ring gear member 90, and these internal gears mesh with external gears 76A and 76B provided on the outer circumferences of the disc portions of the brake pads 14A and 14B, respectively. is doing. As in the case of the first embodiment, the external gears 76A and 76B and the internal gears 78A and 78B transmit the rotational torque between the brake rotor 12 and the brake pads 14A and 14B. And 80B.

As understood from the comparison between FIG. 2 and FIG. 1, the other points of the second embodiment are configured in the same manner as the first embodiment described above. Accordingly, the second embodiment operates in the same manner as the first embodiment, except that the brake pads 14A and 14B are pressed in the directions approaching each other by the pressing force by the piston- cylinder devices 54A and 54B, respectively.

Therefore, according to the second embodiment, as in the case of the first embodiment, it is possible to generate a braking torque far higher than that of a conventional brake device having a general structure. It is possible to generate a higher braking torque than the brake device described in 1).

If the distances of the brake device 10 are the same as in the first embodiment, the servo ratios Rbt1 and Rbt2 of the braking torque are also the same as in the first embodiment. Therefore, according to the second embodiment, in the case of the above specifications, it is possible to generate a braking torque about 10 times that of a brake device having a conventional general structure, and is described in the above-mentioned publication. A braking torque about 5 times that of the braking device can be generated.

[Third embodiment]
FIG. 3 is a cross-sectional view showing a third embodiment of the friction brake device according to the present invention configured as a vehicle brake device, cut along a cut surface passing through the rotation axis, and FIG. 4 is shown in FIG. FIG. 3 is a partial cross-sectional view showing a wedge-type rotational torque-pressing force conversion mechanism cut along a cylindrical cut surface extending around a rotation axis.

As can be seen from a comparison between FIG. 3 and FIG. 1, in this third embodiment, instead of the ball screw mechanisms 42A and 42B in the first and second embodiments, a wedge-type rotational torque-pressing force conversion mechanism. 90A and 90B are provided. In FIG. 3, two rotational torque-pressing force conversion mechanisms 90A and 90B are shown. However, there may be only one rotational torque-pressing force conversion mechanism, and the rotation torque-pressing force conversion mechanism is uniform around the rotation axis 36. A plurality of rotational torque-pressing force conversion mechanisms may be provided in a state of being spaced apart from each other.

Each of the rotational torque-pressing force conversion mechanisms 90A and 90B is provided on the outer surface of the inner end of the cylindrical portion of the pressing members 34A and 34B, and has a cylindrical shoulder facing radially outward and the cylinders of the support members 40A and 40B. Balls 92A and 92B interposed between the two parts are included. Balls 92A and 92B are made of a material such as a substantially rigid metal.

The surfaces of the pressing member 34A and the support member 40A facing each other along the rotation axis 36 in the radial region where the ball 92A is disposed have cam surfaces 34AZ and 40AZ that can engage with the ball 92A, respectively. . Similarly, the surfaces of the pressing member 34B and the support member 40B facing each other along the rotation axis 36 in the radial region where the ball 92B is disposed have cam surfaces 34BZ and 40BZ that can be engaged with the ball 92B, respectively. is doing. Each cam surface extends in an arc shape centering on the rotation axis 36.

As shown in FIG. 4, the cam surface 34AZ includes a curved portion 34AZA that opens toward the support member 40A, and planar inclined portions 34AZB and 34AZC that extend from the curved portion to both sides of the curved portion. And have. The inclined portions 34AZB and 34AZC are inclined with respect to a virtual plane 94 perpendicular to the rotation axis 36 so as to approach the support member 40A as the distance from the curved portion 34AZA increases. Similarly, the cam surface 40AZ has a curved portion 40AZA that opens toward the pressing member 34A, and planar inclined portions 40AZB and 40AZC that extend continuously from the curved portion to both sides of the curved portion. The inclined portions 40AZB and 40AZC are inclined with respect to the virtual plane 94 so as to approach the pressing member 34A as the distance from the curved portion 40AZA increases.

In the illustrated embodiment, as shown in FIG. 4, the inclination angles of the inclined portion 34AZB and the like with respect to the virtual plane 94 are the same. Therefore, the inclined portions 34AZB and 40AZC and 34AZC and 40AZB facing each other in the radial direction of each ball 92A are inclined in the same direction with respect to the virtual plane 94 and extend in parallel to each other.

Although not shown in the figure, the rotational torque-pressing force conversion mechanism 90B has the same structure as the rotational torque-pressing force conversion mechanism 90A. That is, the cam surfaces 34BZ and 40BZ are formed in the same manner as the cam surfaces 34AZ and 40AZ, respectively, except that the direction along the rotation axis 36 is opposite.

In addition, as understood from the comparison between FIG. 3 and FIG. 1, in the third embodiment, the rotational torque transmitting members 82A and 82B are fixed to the pressing members 34A and 34B. As shown in FIG. 3, the pressing members 34 </ b> A and 34 </ b> B extend over the entire circumference around the rotation axis 36 in a region radially opposed to the small diameter portion of the shaft portion of the brake pads 14 </ b> A and 14 </ b> B. Notches are provided. The rotational torque transmission members 82A and 82B are arranged in a state in which these notches are accommodated.

The elastic cylinders of the rotational torque transmitting members 82A and 82B are fixed to the side surfaces of the pressing members 34A and 34B by means such as adhesion, and the end surfaces of the hard cylinders are the large and small diameter portions of the shaft portions of the brake pads 14A and 14B. Opposite the shoulder between. Therefore, also in the third embodiment, the shaft portions of the brake pads 14A and 14B and the rotational torque transmission members 82A and 82B cooperate with each other to limit the transmission of rotational torque between the brake pad and the pressing member. It functions as rotational torque transmission limiting mechanisms 84A and 84B.

As understood from the comparison between FIG. 3 and FIG. 1, the other points of the third embodiment are configured in the same manner as the first embodiment described above. Accordingly, the third embodiment is the first embodiment except that the rotational torque of the brake rotor 12 is converted into the pressing force for the brake pads 14A and 14B by the wedge-type rotational torque-pressing force conversion mechanisms 90A and 90B. Operates in the same way. As in the first and second embodiments, in addition to the braking torque Trv due to the revolution of the brake pads 14A and 14B, the braking torque Trt due to the rotation is generated, and the sum of these becomes the braking torque Tb.

For example, as shown in FIG. 3, during non-braking when the pressure in the cylinder chamber 52 of the piston-cylinder device 54 is not increased, the components of the rotational torque-pressing force converting mechanism are the pressing member 34A and the supporting member 40A. Positioned in the standard position shown in FIG. When the pressing members 34A and 34B and the supporting members 40A and 40B are in the standard positions, the distance between the pressing members 34A and 34B and the supporting members 40A and 40B in the direction along the rotation axis 36 is minimized, and the two No force for separating the pressing members is generated. Therefore, the brake pads 14A and 14B are not substantially frictionally engaged with the disc portion 20A and the sub-rotor 22, respectively, and no braking force is generated.

On the other hand, during braking in which the pressure in the cylinder chamber 52 is increased, the pressing members 34A and 34B are pressed against the brake pads 14A and 14B via the rotational torque transmitting members 82A and 82B by the pressing force of the piston-cylinder device 54. The Therefore, the brake pads 14A and 14B are frictionally engaged with the disk portion 20A and the sub-rotor 22, respectively.

Further, the rotational torques of the disk portion 20A and the sub-rotor 22 are converted into rotational torque around the rotation axis 36 by the rotational torque transmission devices 80A and 80B, respectively, and transmitted to the brake pads 14A and 14B. The rotational torque of the brake pads 14A and 14B is transmitted to the pressing members 34A and 34B via the rotational torque transmission members 82A and 82B. Therefore, the pressing members 34A and 34B rotate relative to the supporting members 40A and 40B around the rotation axis 36, respectively.

As a result, as shown in FIG. 5, the pressing member 34A and the support member 40A are relatively rotated and displaced in opposite directions, so that the cam surfaces 34ZA and 40ZA at the position of the ball 38A tend to approach each other. However, since the ball 38A is not compressed and deformed, a so-called wedge effect is generated, and the pressing member and the support member 16 are relatively displaced along the rotation axis 36 in a direction away from each other. Accordingly, the pressing force of the brake pads 14A and 14B against the disc portion 20A and the sub-rotor 22 is increased.

The braking torques Trv and Trt are proportional to the pressing force of the brake pads 14A and 14B against the disc portion 20A and the sub-rotor 22. These pressing forces are increased by the wedge-type rotational torque-pressing force conversion mechanisms 90A and 90B, and these pressing forces are proportional to the hydraulic pressure in the cylinder chamber 52 of the piston-cylinder device 54. Therefore, by controlling the pressing force by controlling the hydraulic pressure in the cylinder chamber 52, the braking torque Tb, that is, the braking force generated by the brake device 10 can be controlled.

Therefore, according to the third embodiment, as in the case of the first and second embodiments, it is possible to generate a braking torque far higher than that of a brake device having a conventional general structure, A braking torque higher than that of the brake device described in the above publication can be generated.

Further, assuming that the distances of the brake device 10 are the same as those in the first embodiment, the inclination angle of the cam surface 34ZA and the like is 14 deg, and the conversion efficiency from the rotational torque to the pressing force is 100%. The servo ratios Rbt1 and Rbt2 of the braking torque are also the same as in the first embodiment. Therefore, according to the third embodiment, in the case of the above specifications, it is possible to generate a braking torque about 10 times that of a brake device having a conventional general structure, and is described in the above-mentioned publication. A braking torque about 5 times that of the braking device can be generated.

In particular, according to the third embodiment, the inclined portions 40AZB and 40AZC of the cam surface 40AZ are inclined in directions opposite to each other with respect to the virtual plane 94, and the inclined portions 40AZB and 40AZC are also opposite to each other in relation to the virtual plane 94. Inclined. Therefore, the wedge-type rotational torque-pressing force conversion mechanisms 90A and 90B use the rotational torque as the pressing force when the pressing members 34A and 34B are rotationally displaced relative to the support members 40A and 40B in any direction. Can be converted. Therefore, a high braking force can be generated with high responsiveness regardless of whether the vehicle is moving forward or backward.

According to the first to third embodiments described above, when the pressing force by the piston-cylinder device 54 increases, the amount of compressive deformation of the rotational torque transmitting members 82A and 82B increases. When the amount of compressive deformation exceeds a preset value, the tip ends of the shaft portions of the brake pads 14A and 14B come into contact with the pressing members 34A and 34B at the position of the rotation axis 36, and from the brake pad to the pressing member. The transmitted rotational torque no longer increases.

Therefore, it is possible to reliably prevent the rotational torque of the pressing member from being converted into a pressing force that presses the brake pad without limit. Further, the pressing force can be increased according to the pressing force by the piston-cylinder device 54 by converting the rotational torque of the pressing member into the pressing force, and the pressing force can be increased without limit. Can be reliably prevented.

Further, according to the first to third embodiments described above, the rotational torque transmitting members 82A and 82B are made of an elastic cylinder and a hard cylinder, and are fitted to the shaft portions of the brake pads 14A and 14B, respectively. Yes. The rigid cylindrical body can be frictionally engaged with the pressing member or the brake pad over the entire circumference around the rotation axis 36.

Therefore, for example, the rotational torque can be more favorably transmitted from the brake pad to the pressing member than when the rotational torque transmitting member is provided only in a partial region around the rotation axis. Further, for example, the rotational torque is transmitted from the rotational friction member to the pressing member as compared with the case where the other end of the rotational torque transmitting member can be frictionally engaged with the brake pad or the pressing portion only in a partial region around the rotation axis. Can be performed satisfactorily. Furthermore, it is possible to reduce the possibility that abnormal wear such as uneven wear occurs on the brake pad or the pressing member frictionally engaged with the other end of the rotational torque transmitting member, and to improve the durability of the brake device.

Further, for example, the rotational torque transmission member is formed only of an elastic material such as hard rubber, and the wear of the rotational torque transmission member is suppressed as compared with the case where the elastic material directly frictionally engages the brake pad or the pressing portion. However, this also improves the durability of the brake device.

In addition, according to the first and third embodiments described above, the disk portion 20A, the cylindrical portion 20B, and the sub-rotor 22 are opened inward in the radial direction when viewed from a radial cut surface passing through the rotation axis 18. It has a letter-shaped cross-sectional shape. The pressing members 34A and 34B and the like are disposed between the disk portion 20A and the sub-rotor 22, and press the brake pads 14A and 14B and the like in a direction away from each other.

Therefore, a caliper that extends across both sides of the brake rotor and supports the friction member and the pressing device and supports the reaction force of the pressing force of the pressing device as in the conventional disc brake device is unnecessary, and the rigidity of the caliper is reduced. It is not necessary to make it higher. Further, since the disk portion 20A and the sub-rotor 22 extend around the rotation axis 18 over the entire circumference, the rigidity of the brake rotor 12 is improved as compared with a caliper that extends only in an arc around the rotation axis. Can be high.

Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. This will be apparent to those skilled in the art.

For example, in each of the above-described embodiments, the rotational torque transmission members 82A and 82B are fitted to the shaft portions of the brake pads 14A and 14B, respectively. However, the rotational torque transmission member may be provided only in a partial region around the rotation axis 36 as long as the rotation torque can be transmitted at a position spaced radially from the rotation axis 36.

The rotational torque transmission members 82A and 82B are made of an elastic cylinder and a hard cylinder, and are fixed to the brake pads 14A and 14B or the pressing members 34A and 34B by the elastic cylinder. However, the rotational torque transmitting members 82A and 82B are supported at one end, for example, by contacting one of the brake pad and the pressing member, and are not fixed as long as they can be frictionally engaged with the other of the brake pad and the pressing member. May be. Further, if the elastic material is also excellent in wear resistance, the hard portion may be omitted.

In the above-described embodiments, the friction engagement members 14A and 14B have the same size, and their rotation axes 36 are aligned with each other. However, the friction engagement members 14A and 14B may have different sizes and diameters, and their rotation axes may not be aligned with each other.

Further, in each of the above-described embodiments, the friction portions 14AA and 14BA of the friction engagement members 14A and 14B are provided at positions having the same radius around the rotation axis 36. However, the friction portions 14AA and 14BA may be provided at positions having different radii.

In each of the above embodiments, the pressing device that presses the pressing members 34A and 34B against the brake pads 14A and 14B is a piston-cylinder device, but the pressing device may be an electromagnetic pressing device.

In the first and second embodiments described above, the rotational torque-pressing force conversion mechanism is the ball screw mechanisms 40A and 42B, but as long as it has a guide groove extending spirally around the rotation axis 36. The screw mechanism may not include a rolling element such as a ball. In this case, the shape of the screw groove and the tooth engaged therewith may be any shape such as an involute tooth shape or a rectangular shape.

In the third embodiment described above, the cam surfaces 34AZ and 40AZ of the wedge-type rotational torque-pressing force conversion mechanisms 90A and 90B are respectively curved portions 34AZA and 40AZA and planes extending on both sides of the curved portion. Inclined portions 34AZB, 40AZB and 34ZC, 40AZC. However, the cam surface of the rotational torque-pressing force conversion mechanism may have another shape as long as it has an inclined surface inclined in the same direction with respect to a virtual plane 94 perpendicular to the rotation axis 36.

For example, as shown in FIG. 6, the cam surface 34AZ may have a mountain shape, and the cam surface 40AZ may have a valley shape that receives the cam surface 34AZ. In this modified example, a rolling element such as a ball may be interposed between the cam surfaces of the pressing member 34A and the support member 40A. Further, as shown in FIG. 7, the inclined portions 34AZB, 40AZB and 34AZC, 40AZC extending on both sides of the curved portion are inclined so that the inclination angle with respect to the virtual plane 94 gradually decreases as the distance from the curved portion increases. May be curved.

Further, as in the third embodiment described above, when a rolling element such as a ball is interposed between the cam surfaces of the pressing member and the support member, only the inclination angle of one cam surface is greater than that of the curved portion. You may curve so that it may become small gradually as it leaves | separates. The rolling element may be a cylindrical roller or a tapered roller.

According to these modified examples, as the relative displacement of the pressing member around the rotation axis 36 and the support member 16 increases, the component of the force that causes the rotational torque to be decomposed in the direction along the rotation axis 36 is gradually increased. Can do. Therefore, the brake characteristic of the brake device can be changed to a progressive brake characteristic.

In the third embodiment described above, the cam surfaces 34AZ and 40AZ have the curved portions 34AZA and 40AZA, respectively. May be.

In the first and third embodiments described above, the cylindrical portion 20B is formed integrally with the disc portion 20A to form the main rotor 20. However, the cylindrical portion 20B may be formed integrally with the sub-rotor 22, and the disc portion 20A, the cylindrical portion 20B, and the sub-rotor 22 may be formed separately.

Moreover, although the brake device of each embodiment is a brake device for vehicles, the brake device of the present invention may be applied to uses other than vehicles.

DESCRIPTION OF SYMBOLS 10 ... Brake device, 12 ... Brake rotor, 14A, 14B ... Brake pad, 18 ... Rotation axis, 20 ... Main rotor, 22 ... Subrotor, 34A, 34B ... Pressing member, 36 ... Spinning axis, 40A, 40B ... Support member, 42A, 42B ... ball screw mechanism, 50 ... stationary member, 54 ... piston-cylinder device, 80A, 80B ... rotational torque transmission device, 82A, 82B ... rotational torque transmission member, 84A, 84B ... rotational torque transmission limiting mechanism, 88 ... Caliper, 90A, 90B ... Wedge-type rotational torque-pressing force conversion mechanism

Claims (8)

1. Rotational torque is mutually transmitted between the brake rotor rotating around the rotation axis, the rotary friction member rotatable around the rotation axis parallel to the rotation axis, and the brake rotor and the rotation friction member. In a friction brake device comprising: a rotational torque transmission device; and a pressing device that presses the rotating friction member against the brake rotor by pressing the pressing member against the rotating friction member.
   A rotational torque-pressing force conversion mechanism for transmitting the rotational torque of the rotational friction member to the pressing member and converting the rotational torque of the pressing member into a pressing force by which the pressing member presses the rotational friction member;
   A friction brake device characterized by that.
2. The pressing member supports the rotational friction member rotatably around the rotation axis, and is supported rotatably around the rotation axis by a stationary support member.
   The rotational torque-pressing force conversion mechanism is disposed between the rotational friction member and the stationary support member, and transmits a rotational torque from the rotational friction member to the pressing member. A rotation-linear displacement conversion mechanism that converts relative rotation of the pressing member with respect to the surrounding stationary support member into linear displacement of the pressing member toward the brake rotor along the rotation axis. The friction brake device according to claim 1.
3. 3. The friction brake according to claim 2, wherein the rotation-linear displacement conversion mechanism is a screw-type rotation-linear displacement conversion mechanism having a guide groove extending spirally around the rotation axis. apparatus.
4. The rotation-linear displacement conversion mechanism is an inclined surface of the pressing member and the stationary support member facing each other along the rotation axis, and is inclined in the same direction with respect to a virtual plane perpendicular to the rotation axis. 3. The friction brake device according to claim 2, wherein the friction brake device is a wedge-type rotation-linear displacement conversion mechanism having an inclined surface extending in an arc shape around the rotation axis.
5. 5. The friction brake device according to claim 4, wherein each inclined surface has regions inclined in opposite directions with respect to the virtual plane.
6. The rotational friction member has a shaft portion extending coaxially with the rotation axis, and the rotational torque transmission member includes a region that is elastically compressible and deformable along the rotation axis, and the rotation torque transmission member And when the amount of compressive deformation in the region becomes equal to or greater than a reference value, the shaft portion engages with the pressing member on the rotation axis, thereby rotating torque transmitted by the rotation torque transmitting member. The friction brake device according to any one of claims 2 to 5, further comprising a rotational torque transmission limiting mechanism for preventing the torque from increasing.
7. The rotational torque transmission member extends along the rotation axis while being fitted to the shaft portion, and is supported at one end by one of the rotational friction member and the stationary support member, and at the other end The friction brake device according to claim 6, wherein the friction brake device can be frictionally engaged with the other of the rotating friction member and the stationary support member over the entire circumference.
8. The friction brake device according to any one of claims 1 to 7, wherein the rotational torque transmission device includes gears provided on the brake rotor and the rotational friction member and meshing with each other.

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