JP5905363B2 - Brake device - Google Patents

Description

  The present invention relates to a brake device used for a vehicle seat height adjustment mechanism and the like.

  In the height adjustment mechanism for a vehicle seat, the output shaft rotates by operating a lever provided on the input side that swings up and down. However, the weight of the seat and the occupant applies a force to the seat to lower the seat. However, the brake device comprised so that an output shaft may not rotate is used (patent document 1).

  Such a brake device includes an outer ring having a cylindrical inner peripheral surface, a plurality of brake cams (clamping members in Patent Document 1) opposed to the inner peripheral surface, and an output side disposed inside the brake cam. A rotating member (in Patent Document 1, a bolt having a wing) is provided. The rotation operation input to the brake cam is transmitted from the brake cam to the operation of the output side rotation member. However, even if the output side rotation member is rotated, the output side rotation member contacts the brake cam and the brake cam is rotated. The force exerted on the brake acts mainly as a force pressing the brake cam against the outer ring, and the rotational force applied to the brake cam by the output side rotating member cannot exceed the frictional force that can be generated between the brake cam and the outer ring. The cam cannot be rotated.

Japanese translation of PCT publication No. 2002-511035

  By the way, when a brake device is provided in the height adjustment mechanism of the vehicle seat, a large load may be applied to the brake device when the vehicle collides. However, in the brake device described in Patent Document 1, when a large load is input to the output-side rotating member, the braking force continues to increase, and when the allowable load is exceeded, there is a possibility that the components of the brake device are deformed.

Accordingly, an object of the present invention is to suppress deformation of a component when a large load is input to an output-side rotating member in a brake device that generates a braking force by pressing a brake cam against an outer ring.
Moreover, an object of this invention is to simplify a structure in the brake device which has the above brake release mechanisms.
Another object of the present invention is to reduce the weight of the brake device.

  In order to achieve the above-described object, the present invention provides an outer ring having a cylindrical inner peripheral surface, and is arranged so as to be aligned in the circumferential direction on the inner side of the outer ring, and at both ends in the circumferential direction on the side facing the outer ring. At least two brake cams having a brake surface that can come into contact with the inner peripheral surface of the outer ring, and a contact portion that is disposed on the radially inner side of each brake cam and is capable of contacting the radially inner surface of the brake cam An output-side rotating member having a rotational force input to the brake cam is transmitted to the operation of the output-side rotating member, while the output-side rotating member has a rotational force of a predetermined value or less in at least one direction. The brake cam is configured not to rotate even if the contact portion presses the brake cam. In this brake device, the brake cam has a first engagement portion, and the output-side rotation member has the first engagement portion when a rotational force larger than the predetermined value is input in the one direction. A second engaging portion that engages in the circumferential direction, and the second engaging portion engages with the first engaging portion, whereby the output-side rotating member and the brake cam rotate integrally. Configured to do.

  According to such a configuration, when a rotational force larger than a predetermined value is input from the outside to the output side rotating member in the one direction, the second engaging portion of the output side rotating member is engaged with the first engagement of the brake cam. Engage with the joint in the circumferential direction to rotate the brake cam. That is, when a large rotational force is input to the output-side rotating member, the brake is released and the brake cam and the output-side rotating member rotate together, so that deformation of parts of the brake device can be suppressed.

In the brake device described above, the brake cam may have a first protrusion that protrudes radially inward, and the first engagement portion may be provided in the first protrusion. .
The output-side rotating member may have a second projecting portion that projects outward in the radial direction, and the second engaging portion may be provided on the second projecting portion.

  According to these structures, a 1st engaging part or a 2nd engaging part can be made into a simple structure.

  In the above-described configuration in which the second engaging portion is provided in the second projecting portion, the contact portion can be provided in the second projecting portion.

  Thus, a structure can be simplified by providing a contact part and a 2nd engaging part in a 2nd protrusion part.

  In the brake device described above, three or more brake cams may be provided side by side in the circumferential direction.

  According to this configuration, compared to the case where there are two brake cams, the points at which force is applied from the brake cam to the outer ring are dispersed in the circumferential direction, so that the outer ring can easily withstand this force. For this reason, it is possible to reduce the weight by reducing the thickness of the outer ring, or to reduce the width of the outer ring and the cam brake, or to reduce the number arranged in the axial direction.

  In the brake device described above, when the surface passing through the midpoint of the inner end of each brake surface and the central axis of the inner peripheral surface of the outer ring is a central surface, the contact portion is the brake cam. Corresponding to the above, it is provided on both sides of the central surface, and the bidirectional rotation of the output side rotation member can be configured not to be transmitted to the brake cam.

  With such a configuration, it is possible to prevent the brake cam from rotating regardless of whether the rotational force input to the output side rotation member is input in the forward or reverse direction, depending on the device to be applied.

  In each of the brake devices described above, it is preferable that the outer ring includes carbon fiber. According to this, it is possible to increase the specific strength of the outer ring and reduce the weight of the brake device.

  The carbon fiber is preferably disposed along at least one of an inner peripheral surface and an outer peripheral surface of the outer ring. As described above, by arranging the carbon fibers along the inner and outer peripheral surfaces where the greatest stress is applied to the outer ring, the strength of the outer ring can be effectively increased and further weight reduction can be achieved.

  As for at least one part of the said carbon fiber, it is desirable for the longitudinal direction of a fiber to be arrange | positioned along the circumferential direction of an outer ring | wheel. Since the carbon fiber has resistance to the tensile force in the longitudinal direction of the fiber, such a configuration can effectively increase the strength of the outer ring and reduce the weight.

  According to the first aspect of the present invention, when a large rotational force is input to the output-side rotating member, the brake is released and the brake cam and the output-side rotating member rotate together. Can be suppressed.

  According to the structure of Claim 2, a 1st engaging part can be made into a simple structure.

  According to the structure of Claim 3, a 2nd engaging part can be made into a simple structure.

  According to the structure of Claim 4, the structure of an output side rotation member can be simplified by providing a contact part and a 2nd engaging part in a 2nd protrusion part.

  According to the configuration of the fifth aspect, it is possible to reduce the weight by reducing the thickness of the outer ring, or to reduce the width of the outer ring and the cam brake, or to reduce the number arranged in the axial direction. It becomes possible.

  According to the configuration of the sixth aspect, depending on the device to be applied, the brake cam can be prevented from rotating regardless of whether the rotational force input to the output side rotating member is input in the forward or reverse direction. .

  According to the structure of Claim 7, the specific strength of an outer ring | wheel can be made high and the weight reduction of a brake device can be achieved.

  According to the structure of Claim 8 or Claim 9, the intensity | strength of an outer ring | wheel can be raised effectively and weight reduction can be achieved.

It is a disassembled perspective view of the brake device concerning one embodiment. It is sectional drawing of the brake device which concerns on one Embodiment. It is a figure explaining operation | movement of a brake device, and shows the case where a rotational force is given to the input side rotation member. It is a figure explaining operation | movement of a brake device, and shows the case where a rotational force is given to the output side rotation member. It is a figure explaining operation | movement of a brake device, and shows the case where big rotational force is given to the output side rotation member. It is a figure explaining operation | movement of a brake device, and shows the case where big rotational force is given to the output side rotation member. It is sectional drawing of the brake device which concerns on a 1st modification. It is sectional drawing of the brake device which concerns on a 2nd modification.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. As shown in FIG. 1, the brake device 100 according to an embodiment includes an outer ring 10, a brake cam 20, an output side rotating member 30, and an input side rotating member 40.

  The outer ring 10 includes a ring portion 11 having a predetermined thickness and a side wall 12 provided on one side surface of the ring portion 11. The ring portion 11 has a cylindrical (circular cross section) inner peripheral surface 11A. A through hole 12A is formed in the side wall 12 corresponding to the central axis of the inner peripheral surface 11A.

  The brake cams 20 are members that generate a braking force between the outer ring 10 and three brake cams 20 are arranged inside the outer ring 10 at equal intervals in the circumferential direction as shown in FIG. The brake cam 20 has a brake surface 21 that protrudes from both ends of the outer ring 10 facing the inner peripheral surface 11 </ b> A, that is, at both ends in the circumferential direction on the outer peripheral side, and can contact the inner peripheral surface 11 </ b> A of the outer ring 10. The brake surface 21 has a cylindrical surface having the same radius as the inner peripheral surface 11A of the outer ring 10, and is in close contact with the inner peripheral surface 11A of the outer ring 10 when the brake cam 20 is urged radially outward. It has become.

  The brake cam 20 has a cylindrical outer peripheral surface 22 having a smaller diameter than the brake surface 21 between the brake surfaces 21 at both ends on the outer peripheral side. Further, the surface on the radially inner side of the brake cam 20 (in this specification, the radial direction and the circumferential direction are based on the inner circumferential surface 11A of the outer ring 10) is a plane that faces the central axis of the outer ring 10. Have. This plane is an abutting surface 23 that abuts an output-side rotating member 30 described later.

  And the brake cam 20 has the rotation input surface 24 in the edge part of the circumferential direction. Further, on both the left and right sides of the contact surface 23 in FIG. 2, there are first projecting portions 25 and 26 that project inward toward the central axis of the outer ring 10. The first protrusions 25 and 26 engage with the output-side rotating member 30 only when a rotational force (excessive rotational force) larger than a predetermined value is input to the output-side rotating member 30 on the left and right inner wall surfaces, respectively. First engaging portions 25A and 26A. All three brake cams 20 have the same configuration.

As shown in FIG. 1, the output-side rotating member 30 is disposed inside the three brake cams 20 and includes a shaft portion 31 and an action portion 32 provided at an end portion of the shaft portion 31. ing.
The shaft portion 31 is a portion that extends toward the side wall 12 of the outer ring 10, is exposed to the outside from the above-described through hole 12 </ b> A, and engages with other components. For example, a gear is provided at the tip of the shaft portion 31 to be engaged with a driving force input gear of a vehicle seat height adjustment mechanism.

The action portion 32 has a substantially disc shape, and as shown in FIG. 2, the action portion 32 protrudes toward the contact surface 23 of each brake cam 20 on the outer periphery thereof, and can be contacted with the contact surface 23. Two projecting portions 35 and 36 are provided. A total of three second protrusions 35 are provided for each contact surface 23, and three second protrusions 36 are provided for each contact surface 23, a total of three. It has been.
Of the pair of second protrusions 35 and 36 provided corresponding to the brake cam 20 provided on the upper side in FIG. 2, the left second protrusion 35 rotates the output side rotation member 30 clockwise. The right-side second protrusion 36 has a contact portion 35A that comes into contact with the contact surface 23 when trying to rotate, and the second protrusion 36 on the right side contacts the contact surface 23 when trying to rotate the output-side rotating member 30 counterclockwise. A contact portion 36A that contacts the surface. Further, the second protrusion 35 on the left side is engaged with the first engagement portion 25A of the brake cam 20 in the circumferential direction when a large counterclockwise rotational force is input to the output-side rotation member 30. The right second projecting portion 36 has a joint portion 35B and engages with the first engaging portion 26A of the brake cam 20 in the circumferential direction when a large clockwise rotational force is input to the output side rotating member 30. A second engaging portion 36B.
The two pairs of second projecting portions 35 and 36 provided corresponding to the two brake cams 20 provided on the lower side in FIG. 2 are provided corresponding to the brake cams 20 provided on the upper side. The second protrusions 35 and 36 are configured in the same manner.

  The abutting portion 35A and the abutting portion 36A are arranged at the midpoint 55 between the two end portions 52 on the left and right inner sides of each brake surface 21 and the central axis (output) of the inner peripheral surface 11A of the outer ring 10 when the brake surface 21 is not operated. A plane passing through the same axis as the rotation axis 56 of the side rotating member 30 is defined as a center plane S1, and is located offset from the center plane S1. The larger the deviation amount D1, the easier it is to transmit the rotational force between the brake cam 20 and the output side rotating member 30, and the smaller the deviation D1, the more difficult it is to transmit the rotational force. Therefore, when the deviation amount D1 is too large, when the rotational force is input to the output side rotating member 30, the brake cam 20 rotates and the braking force cannot be generated. This deviation amount D1 depends on the friction coefficient between the contact portions 35A, 36A and the contact surface 23, the friction coefficient between the brake surface 21 and the inner peripheral surface 11A of the outer ring 10, the size of the distance between the end portions 52, and the like. Set as appropriate.

  The brake device 100 sets the shift amount D1 to an appropriate size, so that the rotation operation input to the brake cam 20 is transmitted to the operation of the output-side rotation member 30, while the rotation operation of the output-side rotation member 30 is performed. Is configured not to be transmitted to the operation of the brake cam 20. In the present embodiment, the abutting portions 35A and 36A are provided on both sides of the central surface S1 corresponding to each brake cam 20, so that the forward and reverse rotating operations of the output side rotating member 30 can be performed. It is configured not to be transmitted to the brake cam 20.

  As shown in FIG. 1, the input-side rotating member 40 includes a disc-shaped main body 41 and three pins 42 that protrude from the main body 41 toward the side wall 12 of the outer ring 10. The pin 42 is provided at a position and thickness that match the gap between the three brake cams 20, that is, the gap between the rotation input surfaces 24. For this reason, the pin 42 is arrange | positioned every 120 degrees centering | focusing on the rotating shaft 56 of the output side rotation member 30 (refer FIG. 2). Further, the pin 42 is disposed in the vicinity of the outer end portion in the radial direction on the rotation input surface 24 in order to easily transmit the rotational force to the brake cam 20.

The operation and effect of the brake device 100 configured as described above will be described.
As shown in FIG. 3, when the clockwise rotation force in the drawing is applied to the input side rotation member 40, the three pins 42 urge the rotation input surface 24 of the brake cam 20 adjacent in the clockwise direction. A rotational force is applied to each brake cam 20. In each brake cam 20, each contact surface 23 comes into contact with the contact portion 36A of the second projecting portion 36 of the output side rotation member 30, and the clockwise rotation from the contact portion 36A to the output side rotation member 30 occurs. Give power. Thus, when the input side rotation member 40 is rotated clockwise, the brake cam 20 and the output side rotation member 30 are integrally rotated clockwise.

  When the input-side rotating member 40 is rotated counterclockwise in the figure, the force application and the rotating direction are reversed, and the brake cam 20 and the output-side rotating member 30 are integrally turned by the same action. Rotate clockwise.

  As shown in FIG. 4, when the rotational force in the clockwise direction in the drawing is applied to the output side rotating member 30 with a magnitude equal to or smaller than a predetermined value, the abutting portions 35A of the three second projecting portions 35 correspond to the corresponding brakes. Abutting on the abutting surface 23 of the cam 20, the abutting surface 23 is pushed radially outward. The force F1 pressing the contact surface 23 acts to rotate the brake cam 20 clockwise according to the amount of the shift amount D1, since the contact point 51A is shifted from the center plane S1 by the shift amount D1. To do. Further, the frictional force F2 acting at the abutting portion 35A also acts to slightly rotate the brake cam 20 clockwise.

  However, the force F <b> 1 generates a force F <b> 3 that presses the brake cam 20 against the inner peripheral surface 11 </ b> A of the outer ring 10 at the brake surface 21. In accordance with this force F3, a frictional force F4 that acts to counteract the force that causes the brake cam 20 to rotate clockwise acts between the inner peripheral surface 11A and the brake surface 21. In the brake device 100 of the present embodiment, since the deviation amount D1 is appropriately set, the force for rotating the brake cam 20 in the clockwise direction cannot exceed the frictional force F4 and is output. The side rotation member 30, the brake cam 20, and the input side rotation member 40 cannot rotate with respect to the outer ring 10. That is, the brake device 100 can generate a braking force.

  In addition, when trying to rotate the output side rotation member 30 counterclockwise in the figure, the method of applying force is reversed and acts in the same manner, and the output side rotation member 30, the brake cam 20, and the input side rotation member 40 cannot rotate with respect to the outer ring 10. That is, the brake device 100 can generate a braking force.

  Here, the operation and effect when a large rotational force is input to the output-side rotating member 30 will be described. As shown in FIG. 5, when a large rotational force is input to the output-side rotating member 30 in the clockwise direction in the figure, the left second protrusion 35 strongly contacts the contact surface 23, and the brake cam 20 is Bend radially outward. As a result, the output-side rotating member 30 can be slightly rotated clockwise relative to the brake cam 20, and the second engagement portion 36 </ b> B of the right-side second protrusion 36 is connected to the first protrusion 26. Engage with the engaging portion 26A in the circumferential direction. When the second engagement portion 36B is engaged with the first engagement portion 26A, the rotational force transmitted from the output-side rotation member 30 to the brake cam 20 increases at a stretch, so this rotational force is increased between the brake surface 21 and the inner periphery of the outer ring 10. As shown in FIG. 6, the output-side rotating member 30 and the brake cam 20 are rotated integrally with the outer ring 10 in the clockwise direction by overcoming the braking force acting with the surface 11A. The input side rotating member 40 also rotates integrally with the output side rotating member 30 and the brake cam 20.

  As described above, when a rotational force larger than a predetermined value is input to the output-side rotating member 30, the output-side rotating member 30 and the brake cam 20 rotate in a clockwise direction. Even when a shocking force is input, it is possible to suppress the output-side rotating member 30, the brake cam 20, or the outer ring 10 from being deformed due to a large force.

  When a large counterclockwise rotational force is input to the output-side rotating member 30, the right second protrusion 36 deflects the brake cam 20 radially outward, and the second engaging portion 35B is the first engaging portion 35B. The output side rotating member 30 and the brake cam 20 are integrally rotated in the counterclockwise direction by engaging with the engaging portion 25A in the circumferential direction (see FIG. 2 for the reference numerals). That is, the deformation of each member can be suppressed in the same manner as in the clockwise direction.

  Further, in the brake device 100 of the present embodiment, the brake cam 20 has first projecting portions 25 and 26, and the first engaging portions 25 </ b> A and 26 </ b> A are provided on the first projecting portions 25 and 26. Therefore, the first engaging portions 25A and 26A can be simply configured. Further, since the second engaging portions 35B and 36B are respectively provided on the second projecting portions 35 and 36 provided on the output side rotating member 30, the second engaging portions 35B and 36B are simply configured. Can do.

  Further, in the brake device 100 according to the present embodiment, the contact portions 35A and 36A are also provided on the second projecting portions 35 and 36, so the contact portions 35A and 36A and the second engagement portions 35B and 36B are simplified. Can be configured.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment. About a concrete structure, it can change suitably in the range which does not deviate from the meaning of this invention.

  For example, in the embodiment, three brake cams 20 are arranged side by side in the circumferential direction, but two brake cams may be arranged side by side in the circumferential direction, or four or more brake cams may be arranged side by side. It may also be configured.

  Moreover, it is good also as a structure which eliminated the 2nd protrusion part 36 of the right side with respect to the said embodiment like the brake device 200 shown in FIG. Further, the output-side rotating member 230 of the brake device 200 is configured to transmit a driving force that can contact the rotation input surface 224 that is the circumferential end surface of the brake cam 220 in the counterclockwise direction instead of the second projecting portion 36. A contact portion 233 is provided. According to such a configuration, when the output-side rotating member 230 is to be rotated clockwise, the brake cam 220 is not rotated but a braking force is generated, but the counterclockwise rotation is attempted. In this case, the rotational force can be transmitted from the driving force transmission contact portion 233 to the brake cam 220 so that the output side rotating member 230, the brake cam 220, and the input side rotating member 40 can be rotated together.

  Moreover, the structure containing the carbon fiber may be sufficient as the ring part 311 of the outer ring | wheel 310 like the brake device 300 shown in FIG. Specifically, the ring portion 311 is provided with a CFRP layer (carbon fiber reinforced plastic layer) 315 along the outer peripheral surface 312 and a CFRP layer 316 along the inner peripheral surface 313. In each CFRP layer 315, 316, the longitudinal direction of a part of the carbon fibers is arranged along the circumferential direction of the outer ring 310 (that is, the carbon fibers are oriented in the circumferential direction).

  According to such a configuration, the specific strength of the outer ring 310 can be increased, and the weight of the brake device 300 can be reduced. Particularly, the brake device 300 reinforces the outer peripheral surface 312 and the inner peripheral surface 313 of the ring portion 311 where the greatest stress is applied, and the longitudinal direction of the carbon fiber is along the circumferential direction of the outer ring 310. The strength of the outer ring 310 can be effectively increased and further weight reduction can be achieved. Note that all of the carbon fibers of the CFRP layers 315 and 316 may be oriented along the circumferential direction of the outer ring 310.

  Further, in the brake device 300 shown in FIG. 8, each brake cam 320 includes one first protrusion 325 that protrudes radially inward along the center surface S <b> 1 on the inner peripheral side thereof. On the other hand, the output side rotation member 330 is formed with a recess 335 for receiving the first protrusion 325 on the outer peripheral side. In such a configuration, the first engagement portions 325A and 325B are provided on the side surface of the first protrusion 325 facing the circumferential direction, and the second engagement portions 335A and 335B are formed on the side surface of the recess 335 facing the circumferential direction. Provided. Even with such a configuration, the second engagement portion 335A engages with the first engagement portion 325A when a large rotational force is input to the output side rotation member 330, as in the above-described embodiment, or Since the second engaging portion 335B engages with the first engaging portion 325B, the output-side rotating member 330 and the brake cam 320 rotate together, and deformation of each member can be suppressed.

  In the above-described embodiment, the contact portions 35A and 36A are provided on the second projecting portions 35 and 36 provided on the output-side rotating member 30, but a protrusion is formed on the contact surface 23 of the brake cam 20 to output the contact. The contact portion of the side rotation member 30 may be a flat surface.

  In the embodiment and each modification, the brake cams are arranged at regular intervals in the circumferential direction. However, the brake cams are not necessarily arranged at regular intervals. However, the brake cams are arranged at equal intervals in the circumferential direction, so that the position of the output side rotation member can be stabilized.

DESCRIPTION OF SYMBOLS 10 Outer ring 11 Ring part 11A Inner peripheral surface 20 Brake cam 21 Brake surface 22 Outer peripheral surface 23 Contact surface 25,26 1st protrusion part 25A, 26A 1st engaging part 30 Output side rotation member 35,36 2nd protrusion part 35A , 36A Contact portion 35B, 36B Second engagement portion 40 Input side rotating member 51A Current contact 52 End portion 55 Midpoint 56 Rotating axis 100 Brake device S1 Central surface

Claims (9)

An outer ring having a cylindrical inner peripheral surface;
At least two brake cams disposed on the inner side of the outer ring in the circumferential direction and having brake surfaces that can come into contact with the inner peripheral surface of the outer ring at both ends in the circumferential direction on the side facing the outer ring;
An output-side rotating member that is disposed on the radially inner side of each of the brake cams and has a contact portion that can contact the radially inner surface of the brake cam;
The rotation operation input to the brake cam is transmitted to the operation of the output-side rotation member, while a torque less than a predetermined value is applied to the output-side rotation member in at least one direction, and the contact portion is A brake device configured to prevent the brake cam from rotating even when the cam is pressed,
The brake cam has a first engagement portion,
The output-side rotation member has a second engagement portion that engages with the first engagement portion in the circumferential direction when a rotational force larger than the predetermined value is input in the one direction.
The brake device, wherein the output side rotation member and the brake cam rotate integrally when the second engagement portion engages with the first engagement portion.   2. The brake according to claim 1, wherein the brake cam has a first projecting portion projecting radially inward, and the first engaging portion is provided in the first projecting portion. apparatus.   The output-side rotating member has a second projecting portion projecting radially outward, and the second engaging portion is provided on the second projecting portion. Item 5. The brake device according to item 2.   The brake device according to claim 3, wherein the contact portion is provided in the second projecting portion.   The brake device according to any one of claims 1 to 4, wherein three or more brake cams are provided side by side in the circumferential direction. A surface passing through the midpoint of the inner end of each brake surface and the central axis of the inner peripheral surface of the outer ring as a central surface,
The abutting portions are provided on both sides of the central surface corresponding to the brake cams, and are configured such that bidirectional rotation of the output side rotation member is not transmitted to the brake cams. The brake device according to any one of claims 1 to 5, wherein the brake device is provided.   The brake device according to any one of claims 1 to 6, wherein the outer ring includes carbon fiber.   The brake device according to claim 7, wherein the carbon fiber is disposed along at least one of an inner peripheral surface and an outer peripheral surface of the outer ring.   The brake device according to claim 8, wherein at least a part of the carbon fibers is arranged such that a longitudinal direction of the fibers is along a circumferential direction of the outer ring.

Images