WO2016031898A1 - Appareil de frein à tambour - Google Patents

Appareil de frein à tambour Download PDF

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Publication number
WO2016031898A1
WO2016031898A1 PCT/JP2015/074166 JP2015074166W WO2016031898A1 WO 2016031898 A1 WO2016031898 A1 WO 2016031898A1 JP 2015074166 W JP2015074166 W JP 2015074166W WO 2016031898 A1 WO2016031898 A1 WO 2016031898A1
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WO
WIPO (PCT)
Prior art keywords
brake
brake shoe
switching lever
drum
pair
Prior art date
Application number
PCT/JP2015/074166
Other languages
English (en)
Japanese (ja)
Inventor
昭彦 関口
Original Assignee
曙ブレーキ工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2014176244A external-priority patent/JP2016050631A/ja
Priority claimed from JP2014176243A external-priority patent/JP2016050630A/ja
Application filed by 曙ブレーキ工業株式会社 filed Critical 曙ブレーキ工業株式会社
Publication of WO2016031898A1 publication Critical patent/WO2016031898A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
    • B60T13/74—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D51/00—Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like
    • F16D51/16—Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like shaped as brake-shoes pivoted on a fixed or nearly-fixed axis
    • F16D51/18—Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like shaped as brake-shoes pivoted on a fixed or nearly-fixed axis with two brake-shoes
    • F16D51/26—Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like shaped as brake-shoes pivoted on a fixed or nearly-fixed axis with two brake-shoes both extending in the same direction from their pivots
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00—Parts or details
    • F16D65/14—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position
    • F16D65/16—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake
    • F16D65/22—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake adapted for pressing members apart, e.g. for drum brakes

Definitions

  • the present invention relates to a drum brake device.
  • Patent Document 1 An electric parking brake device in which a parking lever that frictionally engages a brake lining of a brake shoe with a brake drum is rotated by a motor is known (see Patent Document 1).
  • This type of electric parking brake device 501 shown in FIG. 15 includes a drum brake 510 having a parking brake mechanism and a drive unit 520 that drives the parking brake mechanism.
  • the drum brake 510 is roughly constituted by a pair of brake shoes 503 and 505 arranged to face an inner peripheral surface of a brake drum (not shown), a parking lever 513, a connecting member 533, a backing plate 511, and an anchor portion 517. It is configured.
  • the pair of brake shoes 503 and 505 are elastically supported by the first shoe hold device 507 and the second shoe hold device 509 so as to be relatively movable within a limited range by the backing plate 511.
  • One end portions 503 a and 505 a of the pair of brake shoes 503 and 505 are supported by an anchor portion 517 fixed to the inner surface of the backing plate 511.
  • the parking lever 513 is disposed along one brake shoe 505 such that a rotation support portion 513a on one end side is rotatably supported on one brake shoe 505.
  • a coupling member 533 is interposed between the parking lever 513 and the other brake shoe 503.
  • the driving unit 520 is roughly configured by a motor 521, a rotation-linear motion conversion mechanism 522, a motion transmission member 523, and a case 524. A portion on the rotating shaft side of the motor 521 is accommodated and fixed in the case 524.
  • the rotation-linear motion conversion mechanism 522 is a mechanism that converts the rotational motion of the rotational shaft of the motor 521 into the linear motion of the screw shaft member 527 in the axial direction.
  • the motion transmission member 523 is a member that transmits a motion transmission force due to the linear motion of the screw shaft member 527 in the axial direction to the parking lever 513.
  • a parking brake switch provided in the driver's seat of the vehicle is operated.
  • the motor 521 rotates, and this rotational motion is transmitted to the rotation-linear motion conversion mechanism 522.
  • the transmitted rotational motion is moved to the right in FIG. 15 by the screw shaft member 527. Converted to linear motion.
  • the parking lever 513 rotates counterclockwise in FIG.
  • the parking lever 513 pushes the brake shoe 505 toward the brake drum with the one end portion 505a supported by the anchor portion 517 of the case 524 as a fulcrum. At the same time, the parking lever 513 pushes the brake shoe 503 via the connecting member 533 toward the brake drum with one end portion 503a supported on the anchor portion 517 of the case 524 as a fulcrum. Therefore, the parking brake is applied by frictionally engaging the pair of expanded brake shoes 503 and 505 with the inner peripheral surface of the brake drum.
  • the anchor portion 517 in order to mount the rotation-linear motion conversion mechanism 522 driven by the motor 521, the anchor portion 517 must be configured as a separate member from the rotation-linear motion conversion mechanism 522. For this reason, the layout of the rotation-linear motion conversion mechanism 522 cannot be made compact, and there is a problem that the electric parking brake device 501 increases in size.
  • the present invention has been made in view of the above situation, and a first object of the present invention is to provide a drum brake equipped with an electric parking brake device that can reduce a decrease in braking effectiveness of the parking brake and that compactly arranges the layout of the motor gear unit. To provide an apparatus.
  • a second object of the present invention is to provide a drum brake device that can reduce a decrease in braking effectiveness and that has a compact layout of an expansion mechanism.
  • the first object of the present invention is achieved by the following configurations (1) to (3).
  • a pair of brake shoes disposed so as to oppose the inner peripheral surface of the brake drum and elastically supported so as to be movable on a backing plate, and interposed between adjacent ends of the pair of brake shoes,
  • a gear housing that is fixed to the backing plate and has an anchor portion that abuts one of the adjacent ends, and is interposed between the other adjacent ends of the pair of brake shoes to expand each of the pair of brake shoes.
  • a switching lever that is rotated by the acting force of the expansion mechanism and a wheel series of the pair of brake shoes.
  • a connecting member that is provided between adjacent ends on the side of the tire and that expands adjacent ends on the wheel cylinder side of the pair of brake shoes in accordance with the rotation of the switching lever.
  • the switching lever is pressed and rotated by the expansion mechanism. Moved to the inside of the brake shoe. Thereby, the other adjacent end side of the other brake shoe is pushed out to the outer peripheral side and pressed against the brake drum. At the same time, the other adjacent end side of one brake shoe is pushed out to the outer peripheral side by the reaction force. Therefore, the other adjacent end side of one brake shoe and the other brake shoe is pressed against the brake drum, and a braking force is generated. Further, the spreading mechanism presses one adjacent end side of each of the pair of brake shoes substantially simultaneously with the pressing to the switching lever.
  • the drum brake device having the above configuration (1) first opens the wheel cylinder side of the pair of brake shoes and presses against the brake drum by the switching lever that is pressed and rotated by the expansion mechanism. Is done.
  • the drum brake device having the above-described configuration (1) has a high parking control as a duo servo that generates a braking force when the gear housing side of the pair of brake shoes is expanded and pressed by the expansion mechanism by the expansion mechanism. Power is obtained, and a decrease in braking effectiveness due to external force after the parking operation is prevented.
  • the motor gear unit is constituted by the gear housing and the expansion mechanism, and is interposed between the adjacent ends of the pair of brake shoes to be attached to the backing plate. It is fixed. And one adjacent end in a pair of brake shoes contacts the anchor part of a gear housing.
  • the anchor portion of the gear housing with which one adjacent end of the pair of brake shoes abuts acts to receive the brake reaction force.
  • the anchor portion of the gear housing works in the same manner as a conventional anchor member, and it becomes unnecessary to configure the anchor member and the motor gear unit as separate members, and the layout of the motor gear unit becomes compact.
  • the expansion mechanism is integrated with the first worm wheel rotated by the electric motor, the first worm wheel rotated by meshing with the first worm shaft, and the first worm wheel.
  • a second worm shaft that is rotated, a second worm wheel that is rotated by meshing with the second worm shaft, and a second worm wheel that is coaxially disposed in the second worm wheel and screwing the rotation of the second worm wheel The drum according to (1), further comprising: a projecting screw for expanding and contracting one adjacent end of the pair of brake shoes by moving both ends projecting from the gear housing forward and backward by converting into linear motion by a mechanism. Brake device.
  • the expansion mechanism is constituted by a two-stage worm gear mechanism including a first worm shaft and a second worm shaft, so that the size is small and a high reduction ratio is easy. Can get to. As a result, the electric motor can be downsized and power consumption can be reduced. Further, at the time of parking brake, first, the wheel cylinder side of the pair of brake shoes is expanded and pressed against the brake drum by the switching lever rotated by the projecting screw projecting from the gear housing, and then the pair of the projecting screws is paired by both ends of the projecting screw. When the gear housing side of the brake shoe is expanded and pressed against the brake drum, a braking force is generated.
  • the wheel cylinder side of the pair of brake shoes is expanded by the wheel cylinder and pressed against the brake drum to generate a braking force, and the brake reaction force acts on the anchor portion of the gear housing. Therefore, an expansion mechanism having the above-described configuration (2) that expands the wheel cylinder side and the gear housing side of the pair of brake shoes during parking brake is interposed between the adjacent ends of the pair of brake shoes.
  • a drum brake device according to (1) or (2), further comprising: a second switching lever that is an output side that rotates following the first switching lever.
  • the first switching lever is rotatably supported by the one brake shoe by the first fulcrum pin.
  • the second switching lever is rotatably supported on one brake shoe by the second fulcrum pin.
  • the switching lever which has a 1st switching lever and a 2nd switching lever comprises the booster mechanism.
  • the positions of the first fulcrum pin and the second fulcrum pin, and the sliding contact position where the first switching lever and the second switching lever abut each other are set.
  • the second object according to the present invention is achieved by the following configurations (4) to (6).
  • a pair of brake shoes disposed so as to face the inner peripheral surface of the brake drum and elastically supported so as to be movable on the backing plate, and interposed between adjacent ends of the pair of brake shoes,
  • a gear housing that is fixed to the backing plate and has an anchor portion with which one of the adjacent ends abuts, and a thrust that is disposed in the gear housing and is driven to expand each of the pair of brake shoes.
  • An expansion mechanism having a generation mechanism, a switching lever that is rotatably provided on one of the brake shoes by a fulcrum pin, and rotated by the acting force of the thrust generation mechanism, and the other adjacent end of the pair of brake shoes
  • a connecting member that is driven by the rotation of the switching lever to expand the other adjacent end of the pair of brake shoes
  • the drum brake device having the above configuration (4) when the thrust generating mechanism of the expansion mechanism is driven during braking, a predetermined gap is provided between one adjacent end of one brake shoe. Therefore, first, the switching lever is pressed by the thrust generating mechanism and rotated around the fulcrum pin, and the connecting member side of the other brake shoe is pushed out to the outer peripheral side by the connecting member. At the same time, the gear housing side of the other brake shoe is pushed out to the outer peripheral side by the thrust generating mechanism and pressed against the inner peripheral surface of the brake drum. And the supporting part of the fulcrum pin of one brake shoe is also pushed out to the outer peripheral side by the reaction force.
  • the supporting portion of the fulcrum pin in one brake shoe, the connecting member side and the gear housing side in the other brake shoe are pressed against the inner peripheral surface of the brake drum, respectively, and the brakes are braked at a total of three locations in the pair of brake shoes.
  • a pressing force in the direction toward the drum is applied, and a braking force is generated. Therefore, in the drum brake device having the configuration (4), when the brake is operated, first, the connecting member side of the other brake shoe is pushed out to the outer peripheral side by the switching lever that is pressed and rotated by the thrust generating mechanism of the spreading mechanism. Pressed against the brake drum.
  • the gear housing side of the other brake shoe is pushed out to the outer peripheral side by the expansion mechanism and pressed against the brake drum, and then the supporting part of the fulcrum pin of one brake shoe is also pushed out to the outer peripheral side by the reaction force.
  • a high braking force can be obtained as a duo servo that generates a braking force by being pressed against the brake drum, and a decrease in braking effectiveness due to an external force after the brake is operated is prevented.
  • the gear housing that houses the expansion mechanism is interposed between the adjacent ends of the pair of brake shoes and fixed to the backing plate. And one adjacent end in a pair of brake shoes contacts the anchor part of a gear housing.
  • the anchor portion of the gear housing with which one adjacent end of the pair of brake shoes abuts acts to receive the brake reaction force.
  • the anchor portion of the gear housing works in the same manner as a conventional anchor member, so that it is not necessary to configure the anchor member and the gear housing as separate members, and the layout of the expansion mechanism becomes compact.
  • the thrust generating mechanism of the expansion mechanism driven by the electric motor is disposed in the gear housing interposed between the adjacent ends of the pair of brake shoes. And disposed inside the backing plate, a small electric drum brake can be provided.
  • the switching lever is rotatably supported on the one brake shoe by the first fulcrum pin and rotatably supported on the one brake shoe by the first switching lever on the input side and the second fulcrum pin.
  • the first switching lever is rotatably supported by the one brake shoe by the first fulcrum pin.
  • the second switching lever is rotatably supported on one brake shoe by the second fulcrum pin.
  • the switching lever which has a 1st switching lever and a 2nd switching lever comprises the booster mechanism.
  • the connecting member side of the other brake shoe becomes the ratio of the booster mechanism by the connecting member abutting between the first switching lever and the second fulcrum pin. It is pushed out to the outer peripheral side by the driving force boosted accordingly.
  • the gear housing side of the other brake shoe is pushed out to the outer peripheral side by the thrust generating mechanism and pressed against the inner peripheral surface of the brake drum.
  • the reaction force also pushes the support portions of the first fulcrum pin and the second fulcrum pin of one brake shoe to the outer peripheral side.
  • the supporting portions of the first and second fulcrum pins in one brake shoe, the connecting member side and the gear housing side in the other brake shoe are respectively pressed against the inner peripheral surface of the brake drum, and the pair of brake shoes A pressing force in the direction toward the inner peripheral surface of the brake drum is applied at a total of four locations, and a braking force is generated. Therefore, in the switching lever having the first switching lever and the second switching lever, the positions of the first fulcrum pin and the second fulcrum pin, and the sliding contact position where the first switching lever and the second switching lever abut each other are set. By setting appropriately, it is possible to easily select an appropriate transmission ratio of the first and second switching levers, and it becomes easy to obtain optimum adhesion between the pair of brake shoes and the drum sliding surface.
  • the service brake is operated by leading trailing and the parking brake is operated by a duo servo. Therefore, it is possible to generate the braking effectiveness of the parking brake with less operating force (current, gear ratio, etc.) than the parking operation by leading trailing, and to reduce the braking effectiveness of the parking brake due to the external force after the parking brake is activated.
  • An electric parking brake device that can reduce the motor gear unit layout in a compact manner can be provided.
  • the brake is operated by a duo servo. Therefore, the brake effect can be generated with less operating force (current, gear ratio, etc.) than the brake operation by leading trailing, and the decrease in the brake effect due to the external force after the brake operation can be reduced.
  • the layout can be compacted.
  • FIG. 1 is a schematic perspective view of a drum brake device according to a first embodiment of the present invention.
  • 2 (a) is a front view of the drum brake device shown in FIG. 1
  • FIG. 2 (b) is a side view of FIG. 2 (a).
  • FIGS. 3A and 3B are a front view and a rear view, respectively, in which a part of the drum brake device shown in FIG. 2 is omitted.
  • 4A is a perspective view in which a part of the drum brake device shown in FIG. 2 is omitted
  • FIG. 4B is a front view in which a part of the main part shown in FIG. is there.
  • FIG. 5A is a front view of the spreading mechanism shown in FIG. 4B
  • FIG. 5B is a side view of FIG.
  • FIG. 6 is a schematic perspective view of a drum brake device according to a second embodiment of the present invention.
  • 7 (a) is a front view of the drum brake device shown in FIG. 6, and
  • FIG. 7 (b) is a side view of FIG. 7 (a).
  • FIG. 8 is a rear perspective view in which a part of the drum brake device shown in FIG. 6 is omitted.
  • 9A is a front view in which a part of the main part of the drum brake device shown in FIG. 7 is cut out
  • FIG. 9B is a rear view in which a part of the drum brake device shown in FIG. 7 is omitted. is there.
  • FIG. 10 (a) is a front view of the spreading mechanism shown in FIG. 9 (a), and FIG.
  • FIG. 10 (b) is a side view of FIG. 10 (a).
  • FIG. 11 is a schematic perspective view of a drum brake device according to a third embodiment of the present invention.
  • 12 (a) is a front view of the drum brake device shown in FIG. 11, and
  • FIG. 12 (b) is a bottom view of FIG. 12 (a).
  • FIG. 13 is a rear perspective view in which a part of the drum brake device shown in FIG. 11 is omitted.
  • 14A is a front view in which a part of the drum brake device shown in FIG. 12 is omitted
  • FIG. 14B is a rear view of FIG. It is a front view of the conventional drum brake device.
  • the drum brake device 11 operates as a leading-trailing (LT) type during service braking by the operation of the wheel cylinder 13 when the foot brake pedal is depressed.
  • LT leading-trailing
  • DS duo-servo
  • the drum brake device 11 including the electric parking brake device according to the first embodiment includes a first brake shoe 21 and a second brake shoe 23 that are a pair of brake shoes, and a first brake shoe 21 and a second brake shoe 23. Between one adjacent end (lower in FIG. 1) and the other adjacent end (upper in FIG. 1) of the first brake shoe 21 and the second brake shoe 23. Wheel cylinder 13, expansion mechanism 15 accommodated in the gear housing 41, switching lever 64 rotatably provided on the first brake shoe 21, wheels of the first brake shoe 21 and the second brake shoe 23. A connecting member 17 provided between adjacent ends on the cylinder side is configured as a main member.
  • the drum brake device 11 is integrally fixed to the vehicle body in such a posture that the backing plate 19 is substantially perpendicular to the rotational axis of a wheel (not shown).
  • a first brake shoe 21 and a second brake shoe 23 which are a pair of brake shoes each having a substantially arc shape, are arranged vertically along the left and right outer peripheral edges.
  • the first brake shoe 21 and the second brake shoe 23 are arranged so as to face the inner peripheral surface of the brake drum 25 (see FIG. 2A).
  • the first brake shoe 21 and the second brake shoe 23 are elastically supported movably on the backing plate 19 by the first shoe hold device 27 and the second shoe hold device 29, and can be expanded.
  • the first brake shoe 21 and the second brake shoe 23 are elastically urged in a direction approaching each other by a pair of first shoe return spring 31 and second shoe return spring 33.
  • a wheel cylinder 13 as a fluid actuator is interposed between the other adjacent ends of the first brake shoe 21 and the second brake shoe 23 in the upper part of FIG.
  • the wheel cylinder 13 is attached to the backing plate 19, and the first piston shoe 21 and the second brake shoe 23 are expanded by pushing away between the other adjacent ends by the first piston 35 and the second piston 37.
  • a gear housing 41 that accommodates the expansion mechanism 15 (see FIG. 4B) is fixed to the backing plate 19 between one adjacent ends of the first brake shoe 21 and the second brake shoe 23 in the lower part of FIG. Is done.
  • the expansion mechanism 15 and the electric motor 39 constitute a motor gear unit in the electric parking brake device.
  • the expansion mechanism 15 is driven by the electric motor 39 to expand the space between one adjacent end of the first brake shoe 21 and the second brake shoe 23.
  • the gear housing 41 fixed to the backing plate 19 has anchor portions 42 and 44 with which one adjacent end of the first brake shoe 21 and the second brake shoe 23 abuts. That is, the gear housing 41 supports one adjacent end of the first brake shoe 21 and the second brake shoe 23 by the anchor portions 42 and 44.
  • the wheel cylinder 13 When the service brake is performed by depressing the foot brake pedal, the wheel cylinder 13 is operated by pressurizing the wheel cylinder 13 and the first piston 35 and the second piston 37 that advance from both ends thereof are used for the first brake shoe 21 and the second brake.
  • the shoe 23 is expanded and rotated from the position shown in FIG. 2 around contact points with the anchor portions 42 and 44.
  • the first brake shoe 21 and the second brake shoe 23 are frictionally engaged with the inner peripheral surface of the brake drum 25 to brake it.
  • one of the first brake shoe 21 and the second brake shoe 23 is a leading shoe with respect to the rotation direction of the brake drum 25 and has a self-servo property, and the other is a trailing shoe with respect to the rotation direction of the brake drum 25.
  • the drum brake device 11 acts as a leading / trailing drum brake.
  • a connecting member 17 is interposed between adjacent ends of the first brake shoe 21 and the second brake shoe 23 in the vicinity of the wheel cylinder 13 via an auto adjuster 45 that adjusts the shoe interval (FIG. 4 ( b)).
  • the connecting member 17 is moved to the inside of the first brake shoe 21 following the rotation of the switching lever 64.
  • the auto adjuster 45 is a shoe gap automatic adjustment mechanism, and defines the standby positions of the first brake shoe 21 and the second brake shoe 23 during non-braking.
  • the auto adjuster 45 includes a guide plate 72 fixed to the web 68 of the second brake shoe 23, a wedge-shaped plate 73 interposed between the one end 17 a of the connecting member 17 and the guide plate 72, and a wedge-shaped plate 73.
  • a tension coil spring 75 that biases one adjacent end side of the second brake shoe 23 and a tension coil spring 74 that biases the connecting member 17 toward the guide plate 72 are configured.
  • the auto adjuster 45 changes the standby positions of the first brake shoe 21 and the second brake shoe 23 according to the wear of the friction material. That is, when the amount of movement of the first brake shoe 21 and the second brake shoe 23 during braking increases due to wear of the friction material, the guide plate 72 fixed to the second brake shoe 23 is pressed via the wedge-shaped plate 73. The distance between the one end of the connecting member 17 and the guide plate 72 is increased. Then, the standby positions of the first brake shoe 21 and the second brake shoe 23 during non-braking are separated from each other, and the shoe gap (the total size of the shoe gaps on both sides) is maintained substantially constant.
  • the gear housing 41 is formed as a block body in which half bodies are combined, and is assembled integrally and fixed to the backing plate 19.
  • the gear housing 41 has sufficient strength to receive the brake reaction force when the first brake shoe 21 and the second brake shoe 23 generate the braking force by the anchor portions 42 and 44.
  • the expansion mechanism 15 of the first embodiment is engaged with the first worm shaft 47 rotated by the electric motor 39 and the first worm shaft.
  • a first worm wheel 49 that rotates, a second worm shaft 51 that rotates together with the first worm wheel 49, a second worm wheel 53 that rotates while meshing with the second worm shaft 51, Have
  • first worm shaft 47 arranged obliquely intersecting with the rotation axis of the second worm wheel 53 rotatably supported by the gear housing 41 is mounted in parallel with the rotation axis of the second worm wheel 53.
  • the gear housing 41 is rotatably supported by a pair of shaft support members 46 having an outer peripheral surface.
  • the second worm shaft 51 arranged orthogonal to the rotation axis of the second worm wheel 53 is geared by a pair of pivot pins 48 having a mounting outer peripheral surface parallel to the rotation axis of the second worm wheel 53.
  • the housing 41 is rotatably supported.
  • the expansion mechanism 15 is rotated by the electric motor 39 to expand each of the first brake shoe 21 and the second brake shoe 23.
  • a projecting screw 58 is coaxially disposed in the second worm wheel 53.
  • the protruding screw 58 includes a first protruding screw 57 having a first protruding end 55 at one end and a male threaded portion 57a at the other end, a second protruding end 59 at one end, and a fitting shaft portion 61a at the other end. And a second projecting shaft 61 having
  • the first projecting screw 57 and the second projecting shaft 61 are arranged coaxially with the second worm wheel 53, the male threaded portion 57 a of the first projecting screw 57 is screwed into the female threaded portion at one end of the second worm wheel 53, and 2
  • the fitting shaft portion 61a of the second protruding shaft 61 is rotatably fitted in the fitting hole at the other end of the worm wheel 53.
  • a thrust bearing 62 is provided between the other end of the second worm wheel 53 and the second projecting end 59 of the second projecting shaft 61 for facilitating mutual relative rotation.
  • the first projecting end portion 55 of the first projecting screw 57 is engaged with the web 69 of the first brake shoe 21 and is prevented from rotating.
  • the first projecting screw 57 When the second worm wheel 53 is rotated, the first projecting screw 57 is The screw is fed to move to the first brake shoe 21 side.
  • the reaction force causes the second worm wheel 53 to move along with the second projecting shaft 61 to the second brake shoe 23 side. Move to.
  • the protruding screw 58 converts the rotation of the second worm wheel 53 into a linear motion by a screw mechanism.
  • the projecting screw 58 moves the first projecting end 55 and the second projecting end 59, which are both ends projecting from the gear housing 41, forward and backward, so that the first brake shoe 21 and the second brake shoe 23 One adjacent end is expanded.
  • the first protruding end 55 is located at one adjacent end of the first switching lever 63 and the first brake shoe 21 in the switching lever 64 described later.
  • the second protruding end portion 59 is not in contact with one adjacent end of the second brake shoe 23.
  • the electric parking brake device includes a switching lever 64.
  • the switching lever 64 is rotatably provided on the web 69 of the first brake shoe 21 and is rotated by the acting force of the spreading mechanism 15.
  • the switching lever 64 of the first embodiment includes a first switching lever 63 that is an input side, and a second switching lever 65 that is an output side that rotates following the first switching lever 63.
  • the first switching lever 63 is rotatably supported on the web 69 of the first brake shoe 21 by the first fulcrum pin 67.
  • the second switching lever 65 is rotatably supported on the web 69 of the first brake shoe 21 by the second fulcrum pin 71.
  • the first shoe return spring 31 urges the first switching lever 63 to rotate in the direction in which the lever end 63 a contacts the web 69 via the second switching lever 65.
  • the switching lever 64 having the first switching lever 63 and the second switching lever 65 constitutes a boosting mechanism.
  • the first switching lever 63 is pressed by the first protruding screw 57 and rotates counterclockwise as shown in FIG. 4B, thereby rotating the second switching lever 65 clockwise.
  • the connecting member 17 that is in contact between the first switching lever 63 and the second fulcrum pin 71 is boosted in accordance with the ratio of the boost mechanism.
  • the first brake shoe 21 is moved inside by the driving force.
  • the reaction force causes the second fulcrum pin 71, which is a connecting portion between the first brake shoe 21 and the second switching lever 65, to be pushed outward (to the right in FIG. 4). Is pushed by the brake drum 25, and a braking force is generated by the first brake shoe 21 and the second brake shoe 23.
  • the connecting member 17 that follows the rotation of the first switching lever 63 and the second switching lever 65 is the first.
  • the distance between the fulcrum, the force point, and the action point is such that the adjacent ends of the brake shoe 21 and the second brake shoe 23 on the anchor portions 42, 44 side are expanded against the urging force of the second shoe return spring 33. Is set.
  • the first switching lever 63 and the second switching lever 65 expand the wheel cylinder side of the first brake shoe 21 and the second brake shoe 23 first by the input from the expansion mechanism 15 and thereby the inner peripheral surface of the brake drum 25. Abut. After the positions of the first brake shoe 21 and the second brake shoe 23 are determined, a reaction force from the inner peripheral surface of the brake drum 25 acts on the first brake shoe 21 and the second brake shoe 23 to expand the expansion mechanism 15. The first switching lever 63 and the second switching lever 65 are rotated to transmit the acting force to the connecting member 17 when the acting force (expanding force) becomes equal to or greater than a predetermined value.
  • the operation of the drum brake device 11 having the configuration according to the first embodiment will be described.
  • the switching lever 64 is pressed and rotated by the expansion mechanism 15. 17 is moved to the inside of the first brake shoe 21.
  • the other adjacent end of the second brake shoe 23 is pushed toward the outer peripheral side and is pressed against the brake drum 25.
  • the other adjacent end of the first brake shoe 21 is also pushed to the outer peripheral side by the reaction force. Therefore, the other adjacent end side of the first brake shoe 21 and the second brake shoe is pressed against the brake drum 25, and a braking force is generated.
  • the expansion mechanism 15 also presses one adjacent end side of the first brake shoe 21 and the second brake shoe 23 substantially simultaneously with the pressing to the switching lever 64.
  • the first and second brake shoes 21 and 23 are applied with a pressing force in the direction toward the brake drum 25 at two locations on each of the one adjacent end side and the other adjacent end side (four locations in total).
  • the drum brake device 11 including the electric parking brake device is configured such that the first brake shoe 21 and the drum brake device 21 are first moved by the switching lever 64 that is pressed and rotated by the expansion mechanism 15 when the parking brake is operated.
  • the other adjacent end side (wheel cylinder 13 side) of the second brake shoe 23 is expanded and pressed against the brake drum 25.
  • one of the adjacent end sides (the gear housing 41 side) of the first brake shoe 21 and the second brake shoe 23 is opened and pressed by the brake drum 25 by the spreading mechanism 15 to generate a braking force.
  • a duo servo a high parking braking force can be obtained, and a decrease in braking effectiveness due to an external force after the parking operation is prevented.
  • the motor gear unit is configured by the gear housing 41 and the expansion mechanism 15 and is adjacent to one of the first brake shoe 21 and the second brake shoe. It is interposed between the ends and fixed to the backing plate 19.
  • first brake shoe 21 and the second brake shoe 23 contacts the anchor portions 42 and 44 of the gear housing 41.
  • the anchor portions 42 and 44 of the gear housing 41 with which one adjacent end of the first brake shoe 21 and the second brake shoe 23 abuts act to receive the brake reaction force.
  • the anchor portions 42 and 44 of the gear housing 41 work in the same manner as a conventional anchor member, and it is not necessary to configure the anchor member and the motor gear unit (expansion mechanism 15) as separate members, and the layout of the motor gear unit. Becomes compact.
  • the gear housing 41 accommodates an expansion mechanism 15 that constitutes a motor gear unit.
  • the expansion mechanism 15 has a projecting screw 58 that expands each of the first brake shoe 21 and the second brake shoe 23 by being rotated by the electric motor 39 when the parking brake is operated.
  • the expansion mechanism 15 is composed of a two-stage worm gear mechanism including the first worm shaft 47 and the second worm shaft 51, it is small and a high reduction ratio can be easily obtained. As a result, the electric motor 39 can be downsized and power consumption can be reduced.
  • the structure of the gear of the expansion mechanism 15 is not limited to the said worm gear, The structure of gears other than a worm may be sufficient.
  • the wheel cylinder 13 side of the first brake shoe 21 and the second brake shoe 23 is expanded by the switching lever 64 rotated by the projecting screw 58 projecting from the gear housing 41 to the brake drum 25. Pressed.
  • the gear housing 41 side of the first brake shoe 21 and the second brake shoe 23 is expanded by the first and second projecting end portions 55 and 59 of the projecting screw 58 and pressed against the inner peripheral surface of the brake drum 25. Thus, a braking force is generated.
  • the wheel cylinder 13 opens the wheel cylinder 13 side of the first brake shoe 21 and the second brake shoe 23 and presses against the brake drum 25 to generate a braking force. Acting on the anchor portions 42, 44.
  • the expansion mechanism 15 configured as described above to expand the wheel cylinder 13 side and the gear housing 41 side of the first brake shoe 21 and the second brake shoe 23 at the time of parking brake is the first brake shoe 21 and the second brake shoe. It is disposed in a gear housing 41 that is interposed between one adjacent ends of the shoe 23 and fixed to the backing plate 19.
  • the anchor portions 42 and 44 that receive the brake reaction force and the motor gear unit can coexist, and the motor gear unit can be placed inside the backing plate 19 even in a small brake size. Placement is easy.
  • the dimension H of the protruding portion of the gear housing 41 that houses the expansion mechanism 15 is reduced on the vehicle mounting surface side shown in FIG.
  • the switching lever 64 in the drum brake device 11 of the first embodiment has a first switching lever and a second switching lever to constitute a boost mechanism.
  • the first switching lever 63 is rotatably supported on the web 69 of the first brake shoe 21 by a first fulcrum pin 67.
  • the second switching lever 65 is rotatably supported on the web 69 of the first brake shoe 21 by the second fulcrum pin 71.
  • the first switching lever 65 When the first switching lever 63 is pressed and rotated by the first projecting screw 57 of the expansion mechanism 15, the first switching lever 65 rotates the second switching lever 65 in the opposite direction.
  • the connecting member 17 that is in contact between the first switching lever 63 and the second fulcrum pin 71 is driven by a driving force that is boosted according to the ratio of the boosting mechanism. Move to the inside of the first brake shoe 21.
  • the switching lever 64 having the first switching lever 63 and the second switching lever 65 the positions of the first fulcrum pin 67 and the second fulcrum pin 71 and the first switching lever 63 and the second switching lever 65 are mutually different.
  • An appropriate transmission ratio of the first and second switching levers 63 and 65 can be easily selected by appropriately setting the sliding contact position P to be in contact. Therefore, it is easy to obtain optimum adhesion between the first brake shoe 21 and the second brake shoe 23 and the drum sliding surface of the brake drum 25.
  • the service brake is operated by leading trailing and the parking brake is operated by a duo servo. Therefore, it is possible to generate the braking effectiveness of the parking brake with less operating force (current, gear ratio, etc.) than the parking operation by leading trailing, and to reduce the braking effectiveness of the parking brake due to the external force after the parking brake is activated.
  • An electric parking brake device that can reduce the motor gear unit layout in a compact manner can be provided.
  • the drum brake device 11 can generate the braking effect with a small operating force by operating the parking brake by a duo servo having a braking effect larger than that of the leading / trailing.
  • the compact motor gear unit in which the electric motor 39 and the expansion mechanism 15 are miniaturized forms the layout of the compact electric parking brake device described above.
  • the drum brake device 111 according to the second embodiment of the present invention has a duo-servo (DS) type drum brake structure, for example, incorporated as a parking brake inside a disc brake. It is.
  • the drum brake device 111 according to the second embodiment includes a first brake shoe 121 and a second brake shoe 123 that are a pair of brake shoes, and one of the first brake shoe 121 and the second brake shoe 123 (in FIG. 6, A gear housing 141 interposed between the adjacent lower ends, an expansion mechanism 115 accommodated in the gear housing 141, a switching lever 164 rotatably provided on the first brake shoe 121, and a first brake shoe. 121 and a connecting member 113 provided between adjacent ends of the second brake shoe 123 on the other side (upper in FIG. 6).
  • the drum brake device 111 is integrally fixed to the vehicle body so that the backing plate 119 is substantially perpendicular to the rotational axis of the wheel (not shown).
  • a first brake shoe 121 and a second brake shoe 123 which are a pair of brake shoes each having a substantially arc shape, are arranged vertically along the left and right outer peripheral edges.
  • the first brake shoe 121 and the second brake shoe 123 are arranged so as to face the inner peripheral surface of the brake drum 125 (see FIG. 7A).
  • the first brake shoe 121 and the second brake shoe 123 are elastically supported movably on the backing plate 119 by the first shoe hold device 127 and the second shoe hold device 129, and can be expanded. Further, the first brake shoe 121 and the second brake shoe 123 are elastically biased in a direction approaching each other by a pair of the first shoe return spring 131 and the second shoe return spring 133.
  • the backing plate 119 between one adjacent end of the first brake shoe 121 and the second brake shoe 123 in the lower part of FIG. 6 has an expansion mechanism 115 (FIG. 9A and FIG. 9) having a speed reduction mechanism and a thrust generation mechanism. 10) is fixed.
  • the expansion mechanism 115 constitutes a motor gear unit together with the electric motor 139.
  • the expansion mechanism 115 is driven by the electric motor 139 to expand the space between one adjacent end of the first brake shoe 121 and the second brake shoe 123.
  • the gear housing 141 fixed to the backing plate 119 has anchor portions 142 and 144 with which one adjacent ends of the first brake shoe 121 and the second brake shoe 123 abut. That is, the gear housing 141 supports one adjacent end of the first brake shoe 121 and the second brake shoe 123 by the anchor portions 142 and 144.
  • a connecting member 113 is interposed between the other adjacent ends of the first brake shoe 121 and the second brake shoe 123 in the upper part of FIG.
  • the switching lever 164 rotates about the fulcrum pin 167 and pushes the connecting member 113 by the first projecting end 155 of the projecting screw 158 which is a thrust generating mechanism of the spreading mechanism 115
  • the second brake shoe 123 is moved to the brake drum 125 It is moved to the inner surface.
  • the connecting member 113 according to the second embodiment is formed between the other adjacent ends of the first brake shoe 121 and the second brake shoe 123 according to the progress of the lining wear of the first brake shoe 121 and the second brake shoe 123. It is an adjuster that can adjust the interval.
  • an expansion mechanism 115 is provided inside the gear housing 141 fixed to the backing plate 119. Since the gear housing 141 is fixed to the backing plate 119, the gear housing 141 has sufficient strength to receive the brake reaction force when the first brake shoe 121 and the second brake shoe 123 generate the braking force by the anchor portions 142 and 144. .
  • the expansion mechanism 115 of the second embodiment meshes with the first worm shaft 147 rotated by the electric motor 139 and the first worm shaft 147.
  • a speed reduction mechanism having
  • first worm shaft 147 disposed obliquely intersecting the rotation axis of the second worm wheel 153 rotatably supported by the gear housing 141 is mounted in parallel with the rotation axis of the second worm wheel 153.
  • the gear housing 141 is rotatably supported by a pair of shaft support members 146 having outer peripheral surfaces.
  • second worm shaft 151 disposed orthogonal to the rotation axis of the second worm wheel 153 is rotatably supported by the gear housing 141.
  • the expansion mechanism 115 expands each of the first brake shoe 121 and the second brake shoe 123 by being rotated by the electric motor 139 as shown in FIG.
  • a projecting screw 158 which is a thrust generating mechanism is arranged coaxially.
  • the protruding screw 158 includes a first protruding screw 157 having a first protruding end 155 at one end and a male threaded portion 157a at the other end, a second protruding end 159 at one end, and a fitting shaft portion 161a at the other end.
  • a second projecting member 161 having
  • the first protruding screw 157 and the second protruding member 161 are arranged coaxially with the second worm wheel 153.
  • the male threaded portion 157a of the first projecting screw 157 is screwed into the female threaded portion at one end of the second worm wheel 153, and the fitting shaft portion of the second projecting member 161 is fitted into the fitting hole at the other end of the second worm wheel 153.
  • 161a is rotatably fitted.
  • a thrust bearing 162 is interposed between the other end of the second worm wheel 153 and the second projecting end 159 of the second projecting member 161 for facilitating mutual relative rotation.
  • the first projecting end 155 of the first projecting screw 157 engages with the web 169 of the first brake shoe 121 and is prevented from rotating.
  • the second worm wheel 153 is rotated, the first projecting screw 157 is rotated. The screw is fed to move to the first brake shoe 121 side.
  • the reaction force causes the second worm wheel 153 to move along with the second projecting member 161 to the second brake shoe 123 side. Move to. Therefore, the protruding screw 158 converts the rotation of the second worm wheel 153 into a linear motion by a screw mechanism.
  • the projecting screw 158 moves the first projecting end 155 and the second projecting end 159, which are both ends projecting from the gear housing 141, to move the switching lever 164 around the fulcrum pin 167.
  • the connecting member 113 moves the connecting member 113 side of the second brake shoe 123 to the inner peripheral surface of the brake drum 125.
  • the projecting screw 158 moves the gear housing 141 side of the second brake shoe 123 to the inner peripheral surface of the brake drum 125.
  • the first projecting end 155 is in contact with a switching lever 164 described later, and the web 169 at one adjacent end of the first brake shoe 121.
  • a predetermined gap d is provided between the two and no contact.
  • the second projecting end 159 is in contact with the web 168 at one adjacent end of the second brake shoe 123.
  • the drum brake device 111 includes a switching lever 164 as shown in FIG.
  • the switching lever 164 is rotatably provided on the web 169 of the first brake shoe 121 and is rotated by the acting force of the expansion mechanism 115.
  • the switching lever 164 of the second embodiment is rotatably supported on the web 169 of the first brake shoe 121 by a fulcrum pin 167.
  • the switching lever 164 When the switching lever 164 is braked, the lower side end is pressed by the first projecting screw 157 and rotated about the fulcrum pin 167 in the clockwise direction in FIG.
  • the connecting member 113 side of the second brake shoe 123 is pushed out to the outer peripheral side (the right direction in FIG. 9B) by the connecting member 113 that is driven according to the lever ratio.
  • the second housing member 161 pushes the gear housing 141 side of the second brake shoe 123 to the outer peripheral side and presses it against the inner peripheral surface of the brake drum 125.
  • the fulcrum pin 167 which is a connecting portion between the first brake shoe 121 and the switching lever 164, is pushed out to the outer peripheral side (left direction in FIG.
  • the switching lever 164 When the switching lever 164 is rotated by the acting force of the expansion mechanism 115, the adjacent end of the first brake shoe 121 and the second brake shoe 123 on the connecting member 113 side is used as the biasing force of the first shoe return spring 131.
  • the distances between the fulcrum, the force point, and the action point are set so as to be expanded against each other.
  • the switching lever 164 transmits a driving force to the connecting member 113 by an input from the expanding mechanism 115 to expand the connecting member 113 side of the second brake shoe 123 first, and abuts the inner peripheral surface of the brake drum 125. .
  • the expansion mechanism 115 side of the second brake shoe 123 is brought into contact with the inner peripheral surface of the brake drum 125 by the input from the expansion mechanism 115, and the reaction force causes the connection member 113 and the expansion mechanism 115 to contact the first brake shoe 121.
  • the acting force is transmitted to the support portion of the fulcrum pin 167.
  • the operation of the drum brake device 111 having the configuration according to the second embodiment will be described.
  • the thrust generating mechanism (protruding screw 158) of the expansion mechanism 115 is driven by the electric motor 139 at the time of braking, at the one adjacent end of the first brake shoe 121. Since a predetermined gap d is provided between the web 169 and the first projecting end 155 of the first projecting screw 157, first, the switching lever 164 is pressed by the thrust generating mechanism to center on the fulcrum pin 167.
  • the connecting member 113 pushes the connecting member 113 side (the upper side in FIG. 6) of the second brake shoe 123 to the outer peripheral side.
  • the gear housing 141 side (the lower side in FIG. 6) of the second brake shoe 123 is pushed out to the outer peripheral side by the thrust generating mechanism and pressed against the inner peripheral surface of the brake drum 125.
  • the support part of the fulcrum pin 167 of the 1st brake shoe 121 is also pushed out to the outer peripheral side with the reaction force.
  • the supporting portion of the fulcrum pin 167 in the first brake shoe 121 and the connecting member 113 side and the gear housing 141 side in the second brake shoe 123 are pressed against the inner peripheral surface of the brake drum 125, respectively. Then, a pressing force in the direction toward the inner peripheral surface of the brake drum 125 is applied at a total of three locations in the first brake shoe 121 and the second brake shoe 123, and a braking force is generated.
  • the connecting member 113 side of the second brake shoe 123 is pushed out to the outer peripheral side by the switching lever 164 that is pressed and rotated by the spreading mechanism 115. And pressed against the brake drum 125.
  • the gear housing 141 side of the second brake shoe 123 is pushed out to the outer peripheral side by the spreading mechanism 115 and is pressed against the brake drum 125.
  • the support portion of the fulcrum pin 167 of the first brake shoe 121 is also pushed to the outer peripheral side and pressed against the brake drum 125, whereby a high parking braking force is obtained as a duo servo that generates a braking force.
  • a decrease in braking effectiveness due to external force after the parking operation is prevented.
  • the gear unit includes the gear housing 141 and the expansion mechanism 115, and one of the first brake shoe 121 and the second brake shoe 123 is adjacent to the gear unit. It is interposed between the ends and fixed to the backing plate 119. One adjacent end of the first brake shoe 121 and the second brake shoe 123 comes into contact with the anchor portions 142 and 144 of the gear housing 141. The anchor portions 142 and 144 of the gear housing 141 with which one adjacent end of the first brake shoe 121 and the second brake shoe 123 abuts act to receive the brake reaction force.
  • the anchor portions 142 and 144 of the gear housing 141 work in the same manner as a conventional anchor member, and it is not necessary to configure the anchor member and the gear unit (expansion mechanism 115) as separate members, and the gear unit layout is compact. become.
  • the gear housing 141 accommodates an expansion mechanism 115 that constitutes a gear unit.
  • the expansion mechanism 115 has a projecting screw 158 as a thrust generation mechanism that expands each of the first brake shoe 121 and the second brake shoe 123 by being rotated by the electric motor 139 when the brake is operated. That is, since the expansion mechanism 115 is constituted by a two-stage worm gear mechanism including the first worm shaft 147 and the second worm shaft 151, the expansion mechanism 115 is small and can easily obtain a high reduction ratio. As a result, the electric motor 139 can be downsized and power consumption can be reduced.
  • the configuration of the gear of the expansion mechanism 115 is not limited to the worm gear, and may be a configuration of a gear other than the worm.
  • the connecting member 113 side of the second brake shoe 123 is pushed to the outer peripheral side by the switching lever 164 rotated by the projecting screw 158 projecting from the gear housing 141 and is pressed against the brake drum 125.
  • the second housing end 159 of the projecting screw 158 pushes the gear housing 141 side of the second brake shoe 123 toward the outer peripheral side and is pressed against the inner peripheral surface of the brake drum 125.
  • the supporting portion of the fulcrum pin 167 of the first brake shoe 121 is also pushed to the outer peripheral side and pressed against the brake drum 125, thereby generating a braking force.
  • the expansion mechanism 115 configured as described above that expands the connecting member 113 side and the gear housing 141 side of the first brake shoe 121 and the second brake shoe 123 during braking is the first brake shoe 121 and the second brake shoe.
  • the gear housing 141 is disposed between the other adjacent ends of the 123 and fixed to the backing plate 119.
  • the anchor portions 142 and 144 that receive the brake reaction force and the gear unit can coexist, and the gear unit can be arranged inside the backing plate 119 even in a small brake size. It becomes easy.
  • the dimension H of the protruding portion of the gear housing 141 that houses the expansion mechanism 115 is reduced on the vehicle mounting surface side shown in FIG. That is, a small electric drum brake can be provided.
  • the drum brake device 211 according to the third embodiment has a duo-servo drum brake structure, like the drum brake device 111 according to the second embodiment. It is built into the disc brake as a parking brake.
  • symbol is attached
  • a switching lever 164A is used instead of the switching lever 164 used in the drum brake device 111 according to the second embodiment.
  • the switching lever 164 ⁇ / b> A includes a first switching lever 163 that is an input side, and a second switching lever 165 that is an output side that rotates following the first switching lever 163.
  • the first switching lever 163 is rotatably supported on the web 169 of the first brake shoe 121 by the first fulcrum pin 167A.
  • the second switching lever 165 is rotatably supported on the web 169 of the first brake shoe 121 by the second fulcrum pin 171.
  • the first shoe return spring 131 urges the first switching lever 163 to rotate in the direction in which the lever end 163 a contacts the web 169 via the second switching lever 165.
  • the switching lever 164A having the first switching lever 163 and the second switching lever 165 constitutes a boost mechanism.
  • a predetermined gap d is provided between the web 169 at the other adjacent end of the first brake shoe 121 and the first projecting end 155 of the first projecting screw 157.
  • the second brake shoe is caused by the connecting member 113 that is in contact with the first switching lever 163 and the second fulcrum pin 171.
  • the connecting member 113 side of 123 is pushed out to the outer peripheral side (right direction in FIG. 14B) with the driving force boosted according to the ratio of the booster mechanism.
  • the gear housing 141 side of the second brake shoe 123 is pushed out to the outer peripheral side by the protruding screw 158 and is pressed against the inner peripheral surface of the brake drum 125.
  • the reaction force also pushes the support portion of the first fulcrum pin 167A and the support portion of the second fulcrum pin 171 of the first brake shoe 121 to the outer peripheral side (the left direction in FIG. 14B). Therefore, the supporting portions of the first and second fulcrum pins 167A and 171 in the first brake shoe 121 and the connecting member 113 side and the gear housing 141 side in the second brake shoe 123 press against the inner peripheral surface of the brake drum 125, respectively.
  • a pressing force in the direction toward the inner peripheral surface of the brake drum 125 is applied at a total of four locations in the first brake shoe 121 and the second brake shoe 123, and a braking force is generated.
  • first switching lever 163 and the second switching lever 165 are rotated by the acting force of the spreading mechanism 115, the adjacent ends of the first brake shoe 121 and the second brake shoe 123 on the connecting member 113 side are set to the first ends.
  • the distance between the fulcrum, the force point, and the action point is set so as to expand against the urging force of the shoe return spring 131.
  • the first switching lever 163 and the second switching lever 165 transmit the driving force to the connecting member 113 by the input from the expanding mechanism 115 to expand the connecting member 113 side of the second brake shoe 123 first, and the brake drum 125. It is made to contact with the inner peripheral surface of.
  • the expansion mechanism 115 side of the second brake shoe 123 is brought into contact with the inner peripheral surface of the brake drum 125 by the input from the expansion mechanism 115, and the reaction force causes the connection member 113 and the expansion mechanism 115 to contact the first brake shoe 121.
  • the acting force is transmitted to the support portions of the first and second fulcrum pins 167A and 171.
  • the switching lever 164A includes a first switching lever 163 and a second switching lever 165 to constitute a boost mechanism.
  • the first switching lever 163 is rotatably supported on the web 169 of the first brake shoe 121 by the first fulcrum pin 167A.
  • the second switching lever 165 is rotatably supported on the web 169 of the first brake shoe 121 by the second fulcrum pin 171.
  • the thrust generating mechanism (projecting screw 158) of the expansion mechanism 115 is driven by the electric motor 139, the web 169 and the first projecting end of the first projecting screw 157 at one adjacent end of the first brake shoe 121 are driven. Since a predetermined gap d is provided between the portion 155 and the first switching lever 163, the first switching lever 163 is first pressed by the first projecting screw 157 of the expansion mechanism 115 and rotated about the first fulcrum pin 167A. The second switching lever 165 is rotated counterclockwise around the second fulcrum pin 171.
  • the connecting member of the second brake shoe 123 is connected by the connecting member 113 that is in contact between the first switch lever 163 and the second fulcrum pin 171.
  • the 113 side is pushed out to the outer peripheral side by the driving force boosted according to the ratio of the booster mechanism.
  • the gear housing 141 side of the second brake shoe 123 is pushed out to the outer peripheral side by the protruding screw 158 and is pressed against the inner peripheral surface of the brake drum 125.
  • the supporting portions of the first fulcrum pin 167A and the second fulcrum pin 171 of the first brake shoe 121 are also pushed out to the outer peripheral side by the reaction force. Therefore, the supporting portions of the first and second fulcrum pins 167A and 171 in the first brake shoe 121 and the connecting member 113 side and the gear housing 141 in the second brake shoe 123 are pressed against the inner peripheral surface of the brake drum 125, respectively. The Then, a pressing force in the direction toward the inner peripheral surface of the brake drum 125 is applied at a total of four locations in the first brake shoe 121 and the second brake shoe 123, and a braking force is generated.
  • the switching lever 164A having the first switching lever 163 and the second switching lever 165 the positions of the first fulcrum pin 167A and the second fulcrum pin 171 and the first switching lever 163 and the second switching lever 165 are mutually different.
  • An appropriate transmission ratio of the first and second switching levers 163 and 165 can be easily selected by appropriately setting the sliding contact position P in contact. Therefore, it is easy to obtain optimum adhesion between the first brake shoe 121 and the second brake shoe 123 and the drum sliding surface of the brake drum 125.
  • the drum brake devices 111 and 211 since the brake is operated by the duo servo, the operation force (current, gear ratio, etc.) is smaller than the brake operation by the leading / trailing. The brake effect can be generated. At the same time, it is possible to reduce a decrease in braking effectiveness due to an external force after the brake is actuated, and the layout of the gear unit can be made compact.
  • the drum brake devices 111 and 211 according to the second and third embodiments can generate a brake effect with a small operating force by operating the brake with a duo servo having a greater brake effect than leading trailing. Accordingly, the compact drum brake device layout described above is established by the compact motor gear unit in which the electric motor 139 and the expansion mechanism 115 are miniaturized.
  • a pair of brake shoes (a first brake shoe 21 and a second brake shoe 23) that are disposed so as to face the inner peripheral surface of the brake drum 25 and are elastically supported by the backing plate 19 so as to be movable.
  • An anchor portion 42 that is interposed between one adjacent ends of the pair of brake shoes (the first brake shoe 21 and the second brake shoe 23) and fixed to the backing plate 19, and the one adjacent ends abut against each other.
  • the pair of brake shoes (the first brake shoe 21 and the second brake shoe 23) are interposed between the other adjacent ends of the pair of brake shoes (the first brake shoe 21 and the second brake shoe 23).
  • the expansion mechanism 15 includes a first worm shaft 47 rotated by the electric motor 39, a first worm wheel 49 rotated by meshing with the first worm shaft 47, and the first A second worm shaft 51 that rotates integrally with the worm wheel 49, a second worm wheel 53 that rotates while meshing with the second worm shaft 51, and the second worm wheel 53 are arranged coaxially.
  • the rotation of the second worm wheel 53 is converted into a linear motion by a screw mechanism, whereby both end portions 55 and 59 protruding from the gear housing 41 are moved forward and backward to move the pair of brake shoes (the first brake shoe 21 and the first brake shoe 21).
  • the drum brake device 11 according to the above [1], further including a projecting screw 58 for expanding one adjacent end of the two brake shoes 23).
  • the switching lever 64 is rotatably supported on the one brake shoe (first brake shoe 21) by a first fulcrum pin 67 and is provided on the input side by a first switching lever 63 and a second fulcrum pin 71.
  • the above-mentioned [1] or [2] having a second switching lever 65 which is rotatably supported by the one brake shoe (first brake shoe 21) and which is an output side which rotates following the first switching lever 63.
  • Drum brake device 11 is rotatably supported on the one brake shoe (first brake shoe 21) by a first fulcrum pin 71.
  • a pair of brake shoes (first brake shoe 121 and second brake shoe 123) that are disposed so as to face the inner peripheral surface of the brake drum 125 and are elastically supported by the backing plate 119 so as to be movable.
  • the anchor portion 142 is interposed between one adjacent ends of the pair of brake shoes (the first brake shoe 121 and the second brake shoe 123) and fixed to the backing plate 119, and the one adjacent end abuts.
  • 144 a gear housing 141 having 144
  • An expansion having a thrust generating mechanism protruding screw 158) that is disposed in the gear housing 141 and is driven to expand each of the pair of brake shoes (first brake shoe 121 and second brake shoe 123).
  • An opening mechanism 115 A switching lever 164 that is rotatably provided on one of the brake shoes (first brake shoe 121) by a fulcrum pin 167, and is rotated by the acting force of the thrust generating mechanism (projecting screw 158); Provided between the other adjacent ends of the pair of brake shoes, and the other adjacent ends of the pair of brake shoes (the first brake shoe 121 and the second brake shoe 123) are expanded by the rotation of the switching lever.
  • the switching lever 164A is rotatably supported on the one brake shoe (first brake shoe 121) by the first fulcrum pin 167A and is provided on the input side with the first switching lever 163 and the second fulcrum pin 171.
  • Drum brake device 211
  • drum brake device of the present invention it is possible to reduce a decrease in the braking effectiveness of the parking brake, and to reduce the braking effectiveness by including the electric parking brake device in which the layout of the motor gear unit is compactly arranged. This is useful for drum brake devices that can reduce the layout of the expansion mechanism in a compact manner.

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  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Transportation (AREA)
  • Braking Arrangements (AREA)

Abstract

L'invention porte sur un appareil de frein à tambour (11), lequel appareil comporte un carter d'engrenages ayant une partie d'ancrage (41) avec laquelle une extrémité de chacune d'une paire de garnitures de frein (21, 23) qui sont adjacentes l'une à l'autre entre en contact, un cylindre de roue (13) qui est interposé entre les autres extrémités de la paire de garnitures de frein (21, 23) qui sont adjacentes l'une à l'autre, un mécanisme d'extension (15) qui est disposé à l'intérieur du carter d'engrenages (41) et qui étend la paire de garnitures de frein (21, 23) à l'aide d'un moteur électrique (39), un levier de commutation (64) qui est mis en rotation à l'aide d'une force exercée par le mécanisme d'extension (15), et un élément de liaison (17), qui, à la suite de la rotation du levier de commutation (64), étend les extrémités adjacentes de la paire de garnitures de frein (21, 23) sur le côté de cylindre de roue.
PCT/JP2015/074166 2014-08-29 2015-08-27 Appareil de frein à tambour WO2016031898A1 (fr)

Applications Claiming Priority (4)

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JP2014176244A JP2016050631A (ja) 2014-08-29 2014-08-29 ドラムブレーキ装置
JP2014-176244 2014-08-29
JP2014-176243 2014-08-29
JP2014176243A JP2016050630A (ja) 2014-08-29 2014-08-29 ドラムブレーキ装置

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US20170051802A1 (en) * 2015-08-20 2017-02-23 Hyundai Mobis Co., Ltd. Brake for vehicle
CN112443629A (zh) * 2020-11-18 2021-03-05 霸州市华诚汽车制动器有限公司 一种多级传动机构
US20220163075A1 (en) * 2019-04-12 2022-05-26 Mando Corporation Electronic parking brake

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JP2012211647A (ja) * 2011-03-31 2012-11-01 Advics Co Ltd 電動駐車ブレーキ装置
JP2014070648A (ja) * 2012-09-27 2014-04-21 Advics Co Ltd 電動駐車ブレーキ装置
JP2014126146A (ja) * 2012-12-26 2014-07-07 Hosei Brake Ind Ltd 電動式ドラムブレーキ

Cited By (3)

* Cited by examiner, † Cited by third party
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US20170051802A1 (en) * 2015-08-20 2017-02-23 Hyundai Mobis Co., Ltd. Brake for vehicle
US20220163075A1 (en) * 2019-04-12 2022-05-26 Mando Corporation Electronic parking brake
CN112443629A (zh) * 2020-11-18 2021-03-05 霸州市华诚汽车制动器有限公司 一种多级传动机构

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