JP2008175303A - Electric parking brake device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric parking brake device for a vehicle, which is lightweight and compact at low costs. <P>SOLUTION: The on-vehicle electric parking brake device comprises a reciprocating member, in which respective body side ends of two parking brake cables connected with parking brakes of which wheel side ends are respectively equipped with a set of left and right wheels are connected with each other to pull or release the parking brake cables by reciprocating on a shaft with a screw in response to motor output, and a housing of the reciprocating member for keeping the inner peripheral surface shaped enough to retain the reciprocating member at a predetermined locking position by engaging with the reciprocating member. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention generally relates to an electric parking brake (parking brake) device mounted on a vehicle, and more particularly, to a low-cost, lightweight and compact electric parking brake device for a vehicle.

  Conventionally, an electric parking brake device for vehicles is known (for example, refer to patent documents 1).

Patent Document 1 includes an equalizer mechanism (C) that evenly distributes a linear driving force obtained by decelerating and converting a rotational driving force, which is an output of an electric motor (11), to two cables (17, 19). An electric parking brake device is disclosed.
JP-A-2005-016600

  In the conventional apparatus described in Patent Document 1, a lock mechanism such as a spring clutch that functions as a stopper for holding the cable tension at the time when the operation of the electric motor is stopped is required.

  The present invention provides a low-cost, lightweight and compact electric parking brake device for a vehicle that realizes a configuration and structure for holding cable tension while the electric motor is stopped without using the lock mechanism as described above. The main purpose is to do.

  One aspect of the present invention for achieving the above object is an electric parking brake device mounted on a vehicle, the wheel side ends of which are respectively connected to parking brakes mounted on a pair of left and right wheels. A reciprocating member that pulls or releases the parking brake cable by reciprocating on a shaft that is threaded in accordance with the output of the motor. An electric parking system for a vehicle having an inner peripheral surface formed in a shape that engages with the reciprocating member and holds the member in a predetermined lock position during operation stop of the reciprocating member. Brake device.

  In the above aspect, in order to realize the holding of the reciprocating member at the predetermined lock position by the inner peripheral surface, for example, A) the inner peripheral surface is reciprocated with respect to the axial direction of the shaft. A moving member that has a sliding surface (for example, an inner peripheral surface of the housing) that is inclined in the same direction as the direction that rotates together with the shaft when the parking brake cable is released by the motor output. Or B) The inner circumferential surface is the same as the direction in which the reciprocating member rotates with the shaft when the reciprocating member releases the parking brake cable by the motor output with respect to the axial direction of the shaft. The side surface has a step that is one step lower, and has a sliding surface (for example, an inner peripheral surface of the housing) with the reciprocating member. Or as having a protrusion which raised side and the sliding of the sliding surface when moving over.

  According to the above aspect, a lock mechanism (for example, a spring-type clutch or the like) for maintaining the cable tension at the time when the operation of the electric motor is stopped becomes unnecessary, so that the number of parts can be reduced and the vehicle The electric parking brake device can be made low-cost, lightweight and compact.

  In the above aspect, when the reciprocating member is released from the predetermined lock position in order to reduce the drag resistance, the parking brake cable is temporarily pulled on the shaft by the motor output. It is preferable to move the parking brake cable in a direction to release the parking brake cable.

  According to the present invention, it is possible to provide an electric parking brake device for a vehicle that is low-cost, lightweight, and compact.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings. Note that the basic concept of the electric parking brake device, the main hardware configuration, the operating principle, the basic control method, and the like are known to those skilled in the art and will not be described in detail.

  First, with reference to FIGS. 1-11, the electric parking brake apparatus which concerns on one Example (Example 1) of this invention is demonstrated.

  FIG. 1 is a schematic configuration diagram of an electric parking brake device 100 for a vehicle according to the present embodiment.

  The vehicle electric parking brake device 100 includes an actuator 101 and a control unit 102 that controls the operation of the actuator 101.

  The control unit 102 is, for example, an ECU (Electronic Control Unit).

  For example, the road surface gradient information is transmitted to the control unit 102, and the actuator 101 is controlled so that the cable tension suitable for the road surface gradient at that time is realized when the electric parking brake is operated.

  Here, the road surface gradient information may be detected by, for example, a front-rear G sensor that detects acceleration in the vehicle front-rear direction, which is known to those skilled in the art, or, for example, GPS ( It may be extracted by illuminating the current position of the host vehicle detected by a Global Positioning System (Global Positioning System) or the like.

  The electric parking brake device 100 is activated by a predetermined operation of the driver (for example, pressing a predetermined button) when the manual mode is set, and is stopped for a long time, for example, when the auto mode is set. Triggered when a situation occurs, such as seat belt removal, driver's seat door open, engine hood open, luggage door open, hydraulic brake system failure.

  The actuator 101 includes an electric motor 103 that rotates according to a command from the control unit 102 and generates a torque for pulling / releasing parking brake cables 107 and 108 described later. As long as such a function is realized, the electric motor 103 may be any type of motor.

  The actuator 101 further includes a housing 104, a shaft 105 and an equalizer 106 housed in the housing 104.

  The rotation of the electric motor 103 is transmitted to the threaded shaft 105, for example, via a gear group that functions as a speed reducer. The shaft 105 passes through the equalizer 106 and is screwed with a female screw cut in the equalizer 106.

  As described above, when the electric motor 103 rotates and thus the shaft 105 rotates, the equalizer 106 reciprocates on the shaft 106 in accordance with the rotation direction.

  The equalizer 106 is connected to the vehicle body side ends of parking brake cables 107 and 108 whose wheel side ends are connected to parking brakes (usually so-called drum brakes) for the left and right rear wheels. The equalizer 106 has a function of evenly distributing the tension to the left and right parking brake cables 107 and 108.

  In the case of a conventional actuator, a lock mechanism (for example, a spring-type clutch) for holding cable tension is generally provided while the electric motor is stopped. Since a stopper for mechanically holding the movement of the equalizer 106 is formed by using the inner peripheral surface of this, there is no need to separately provide a lock mechanism such as a spring clutch.

  More specifically, the inner peripheral surface of the housing 104 according to the present embodiment is divided into a flat lock region surface 104a and a sliding region surface 104b inclined with respect to the lock region surface 104a.

  Hereinafter, with reference to FIGS. 2 to 11, how the cable tension holding while the electric motor 103 is stopped is realized by the lock region surface 104 a and the sliding region surface 104 b will be described.

  2 to 4 are a perspective view, a top view, and an axial side view, respectively, showing a state where the equalizer 106 is on the sliding area surface 104b.

  As shown in the drawing, the bottom surface of the equalizer 106 slides on the sliding region surface 104b when the equalizer 106 linearly moves on the sliding region surface 104b along the shaft 105.

  In the figure, an arrow A is a release direction in which the cable tension is loosened, and an arrow B is a pulling direction in which the cable tension is increased. Further, here, when the equalizer 106 is wound up in the pulling direction B by the rotation of the shaft 105, the sliding is performed in the rotation direction as indicated by the arrow C in FIG. The inclination direction of the area surface 104b and the screw direction of the shaft 105 are determined.

  5 to 7 are a perspective view, a top view, and an axial side view showing a state where the equalizer 106 is held in the locked position, respectively.

  As described above, when the equalizer 106 is wound in the pulling direction B, the equalizer 106 rotates in the rotation direction indicated by the arrow C in FIG. When entering the lock area surface 104a, it rotates in the direction C and becomes substantially horizontal with the lock area surface 104a. When the operation of the electric motor 103 stops in this state, the equalizer 106 comes into contact with the side surface of the raised portion of the inner peripheral surface of the housing 104, which partially forms the sliding region surface 104b, as shown in FIG. Further, the equalizer 106 cannot move in the release direction A.

  Due to the engagement state between the stopper portion formed on the inner peripheral surface of the housing 104 and the equalizer 106, the equalizer 106 is held at the position shown in FIGS. 5 to 7, and thus the cable tension is also kept at the tension in that state. The

  FIGS. 8 to 11 are respectively a perspective view, a top view, and two axial side views showing a state in which the equalizer 106 is released for releasing the parking brake from the state where the equalizer 106 is held in the locked position.

  When the equalizer 106 is released from the holding state in the lock position shown in FIGS. 5 to 7 to release the parking brake and moved on the sliding area surface 104b in the release direction A, first, the electric motor 103 is moved. Once the equalizer 106 is rotated in the winding direction, the equalizer 106 is pulled away from the engaged state with the side surface of the sliding region surface 104b.

  Then, the equalizer 106 once rotates in the direction of the arrow C as shown in FIG.

  Here, when the rotation direction of the electric motor 103 is switched and the shaft 105 is rotated so that the equalizer 106 moves in the release direction A along the shaft 105, this time, the equalizer is directed in the direction of the arrow D as shown in FIG. 106 rotates together.

  FIG. 8 shows a state in which the equalizer 106 is thus disengaged and the shaft 105 moves the equalizer 106 in the release direction A.

  As described above, when releasing, the equalizer 106 can be locked in advance by moving the equalizer 106 in the winding direction once so that the direction of the equalizer 106 matches the inclination of the sliding area surface 104b in advance. It can move smoothly without being caught when moving from the area surface 104a to the sliding area surface 104b.

  As described above, according to the present embodiment, the shape design of the inner peripheral surface of the housing 104 realizes that the equalizer 106 is held in the locked position while the electric motor 103 is stopped. An equalizer holding member such as a mechanical stopper which is a separate member from the mechanism and the housing is not required, and the cost, weight and size of the actuator 101 can be reduced.

  In the conventional electric parking brake device, a tension sensor is generally provided on at least one of the parking brake cables, and the measurement value is generally transmitted to a control unit that controls the operation of the actuator. According to the present embodiment, such a tension sensor is also unnecessary.

  In the present embodiment, the position where the equalizer 106 is held while the electric motor 103 is stopped is determined in one place, and the electric motor 103 requires a larger current as the equalizer 106 is wound up. Cable tension is estimated using a sensor that measures the distance from the current position of the equalizer 106 to the lock position, or an ammeter that measures the magnitude of the current value supplied to the electric motor 103, instead of the tension sensor. can do.

  Next, an electric parking brake device according to another embodiment (embodiment 2) of the present invention will be described with reference to FIGS. The schematic configuration of the vehicle electric parking brake device 100 according to the present embodiment is the same as that of the vehicle electric parking brake device according to the first embodiment, and therefore illustration and detailed description thereof are omitted.

  The present embodiment differs from the first embodiment in that the shape of the inner peripheral surface of the housing 104 that functions as a stopper for the equalizer 106 is not an inclined surface but a stepped surface. Further, the equalizer 106 according to the present embodiment is formed with a raised portion 106a in addition to the step surface.

  More specifically, in this embodiment, the surface on which the equalizer 106 slides on the inner peripheral surface of the housing 104 includes a higher step surface 104c that slides with the raised portion 106a of the equalizer 106 and a lower step surface. 104d.

  In this embodiment, as an example, it is assumed that the step surfaces 104c and 104d have a lateral width that bisects the width direction, and the raised portion 106a of the equalizer 106 is hemispherical.

  12 to 14 are a perspective view, a top view, and an axial side view showing a state where the equalizer 106 is on the stepped surfaces 104c and 104d, respectively.

  As shown in the drawing, the raised portion 106a of the equalizer 106 slides on the step surface 104c when the equalizer 106 linearly moves on the step surfaces 104c and 104d along the shaft 105.

  In the figure, an arrow A is a release direction in which the cable tension is loosened, and an arrow B is a pulling direction in which the cable tension is increased. Further, here, when the equalizer 106 is wound up in the pulling direction B by the rotation of the shaft 105, the step surface is rotated in the rotation direction as indicated by an arrow C in FIG. 14 by screw friction with the shaft 105. Which of 104c and 104d is made higher and the screw direction of the shaft 105 are determined.

  FIGS. 15 to 17 are a perspective view, a top view, and an axial side view showing a state in which the equalizer 106 is held in the locked position, respectively.

  As described above, when the equalizer 106 is wound in the pulling direction B, the equalizer 106 rotates together in the rotation direction indicated by the arrow C in FIG. 14, so that the equalizer 106 passes over the step surfaces 104 c and 104 d and the entire equalizer 106 is completely completed. When entering the lock area surface 104a, it rotates in the direction C and becomes substantially horizontal with the lock area surface 104a. When the operation of the electric motor 103 stops in that state, the equalizer 106 abuts against the side surface of the raised portion of the inner peripheral surface of the housing 104 where the raised portion 106a forms the stepped surface 104c, as shown in FIG. After that, the equalizer 106 cannot move in the release direction A.

  Due to the engagement state between the stopper portion formed on the inner peripheral surface of the housing 104 and the equalizer 106, the equalizer 106 is held at the position shown in FIGS. 15 to 17, and thus the cable tension is also held at the tension in that state. The

  FIGS. 18 to 21 are a perspective view, a top view, and two axial side views showing a state in which the equalizer 106 is released for releasing the parking brake from the state where the equalizer 106 is held in the locked position.

  When releasing the equalizer 106 from the holding state shown in FIGS. 15 to 17 to release the parking brake and moving it on the step surfaces 104c and 104d in the release direction A, first, the electric motor 103 is turned on. The equalizer 106 is once rotated in the winding direction, and the equalizer 106 is pulled away from the engaged state with the side surface of the step surface 104c.

  Then, the equalizer 106 once rotates in the direction of the arrow C as shown in FIG.

  Here, when the rotation direction of the electric motor 103 is switched and the shaft 105 is rotated so that the equalizer 106 moves in the release direction A along the shaft 105, this time, the equalizer is moved in the direction of the arrow D as shown in FIG. 106 rotates together.

  FIG. 18 shows a state where the equalizer 106 is thus disengaged and the shaft 105 moves the equalizer 106 in the release direction A.

  As described above, when releasing, the equalizer 106 is once moved in the winding direction, so that the direction of the equalizer 106 can be set in an inclined state such that the raised portion 106a rides on the stepped surface 104c in advance. 106 can move smoothly without being caught when moving from the lock area surface 104a to the step surfaces 104c and 104d.

  As described above, according to this embodiment, the shape of the inner peripheral surface of the housing 104 and the equalizer 106 can be used to hold the equalizer 106 in the locked position while the electric motor 103 is stopped. Thus, there is no need for an equalizer holding member such as a mechanical stopper separate from the lock mechanism or the housing, and the actuator 101 can be reduced in cost, weight, and size.

  In this embodiment as well, the position where the equalizer 106 is held while the electric motor 103 is stopped is determined in one place, and the electric motor 103 requires a larger current as the equalizer 106 is wound up. Instead of providing a sensor in the parking brake cable, a cable that uses a sensor that measures the distance from the current position of the equalizer 106 to the lock position, an ammeter that measures the magnitude of the current value supplied to the electric motor 103, etc. The tension can be estimated.

  INDUSTRIAL APPLICABILITY The present invention can be used for an electric parking brake device for a vehicle having a configuration / structure that employs the equalizer as described above. The power source type, fuel type, appearance design, weight, size, running performance, etc. of the vehicle to be mounted are all unquestioned.

1 is a schematic configuration diagram of an electric parking brake device for a vehicle according to an embodiment (Embodiment 1) of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a state where an equalizer is on a sliding area surface in an electric parking brake device for a vehicle according to one embodiment (first embodiment) of the present invention. 1 is a top view showing a state where an equalizer is on a sliding area surface in an electric parking brake device for a vehicle according to one embodiment (first embodiment) of the present invention. FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an axial side view showing a state where an equalizer is on a sliding area surface in an electric parking brake device for a vehicle according to one embodiment (first embodiment) of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a state where an equalizer is held at a lock position in an electric parking brake device for a vehicle according to one embodiment (first embodiment) of the present invention. 1 is a top view showing a state where an equalizer is held at a lock position in an electric parking brake device for a vehicle according to one embodiment (first embodiment) of the present invention. FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an axial side view showing a state in which an equalizer is held at a lock position in an electric parking brake device for a vehicle according to an embodiment (Embodiment 1) of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a state where an equalizer is held at a lock position in an electric parking brake device for a vehicle according to one embodiment (first embodiment) of the present invention. 1 is a top view showing a state where an equalizer is held at a lock position in an electric parking brake device for a vehicle according to one embodiment (first embodiment) of the present invention. FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an axial side view showing a state in which an equalizer is held at a lock position in an electric parking brake device for a vehicle according to an embodiment (Embodiment 1) of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an axial side view showing a state in which an equalizer is held at a lock position in an electric parking brake device for a vehicle according to an embodiment (Embodiment 1) of the present invention. FIG. 7 is a perspective view showing a state where an equalizer is on a sliding area surface in an electric parking brake device for a vehicle according to another embodiment (Embodiment 2) of the present invention. In the electric parking brake device for a vehicle according to another embodiment of the present invention (embodiment 2), it is a top view showing a state where the equalizer is on the sliding area surface. In the electric parking brake device for a vehicle according to another embodiment (Embodiment 2) of the present invention, FIG. FIG. 6 is a perspective view showing a state where an equalizer is held at a lock position in an electric parking brake device for a vehicle according to another embodiment (Embodiment 2) of the present invention. FIG. 6 is a top view showing a state where an equalizer is held at a lock position in an electric parking brake device for a vehicle according to another embodiment (Example 2) of the present invention. FIG. 6 is an axial side view showing a state where an equalizer is held at a lock position in an electric parking brake device for a vehicle according to another embodiment (Embodiment 2) of the present invention. FIG. 6 is a perspective view showing a state where an equalizer is held at a lock position in an electric parking brake device for a vehicle according to another embodiment (Embodiment 2) of the present invention. FIG. 6 is a top view showing a state where an equalizer is held at a lock position in an electric parking brake device for a vehicle according to another embodiment (Example 2) of the present invention. FIG. 6 is an axial side view showing a state where an equalizer is held at a lock position in an electric parking brake device for a vehicle according to another embodiment (Embodiment 2) of the present invention. FIG. 6 is an axial side view showing a state where an equalizer is held at a lock position in an electric parking brake device for a vehicle according to another embodiment (Embodiment 2) of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Electric parking brake apparatus for vehicles 101 Actuator 102 Control part 103 Electric motor 104 Housing 104a Lock area surface 104b Sliding area surface 104c, 104d Step surface 105 Shaft 106 Equalizer 107, 108 Parking brake cable

Claims (4)

An electric parking brake device mounted on a vehicle,
The vehicle side ends of the two parking brake cables connected to the parking brakes mounted on the left and right wheels respectively connected to the pair of left and right wheels are connected to and reciprocated on the threaded shaft according to the motor output. A reciprocating member that pulls or releases the parking brake cable by moving;
A housing for the reciprocating member having an inner peripheral surface formed to engage with the reciprocating member and hold the member in a predetermined locking position while the motor is stopped. An electric parking brake device for vehicles. The electric parking brake device for a vehicle according to claim 1,
The reciprocating movement in which the inner peripheral surface is inclined with respect to the axial direction of the shaft in the same direction as the reciprocating member rotates together with the shaft when the parking brake cable is released by the motor output. An electric parking brake device for a vehicle having a sliding surface with a member. The electric parking brake device for a vehicle according to claim 1,
The inner peripheral surface has a step that is one step lower on the same side as the direction in which the reciprocating member rotates together with the shaft when the reciprocating member releases the parking brake cable by the motor output with respect to the axial direction of the shaft. Having a sliding surface with the reciprocating member;
The electric parking brake device for a vehicle according to claim 1, wherein the reciprocating member has a protrusion that slides with the one higher side of the sliding surface when moving on the shaft. It is an electric parking brake device for vehicles according to any one of claims 1 to 3,
When the reciprocating member is released from the predetermined lock position, the reciprocating member is once moved in the direction of pulling the parking brake cable on the shaft by the motor output, and then in the direction of releasing the parking brake cable. An electric parking brake device for a vehicle, wherein the electric parking brake device is moved.

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