JP5280068B2 - Control unit integrated seat belt device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seatbelt device integrated with a control unit, achieving miniaturization by the optimum arrangement and structure of the control unit and having excellent mountability on a vehicle. <P>SOLUTION: This seatbelt device includes at least a motor retractor 10 provided with at least a spool 12 taking up a webbing belt, a motor 20 taking up or rewinding the webbing belt 19 by rotating the spool and a power transmission mechanism section 16 transmitting the rotating torque of the motor to the spool, and the control unit 30 controlling rotation of the motor. The motor retractor has a recessed portion formed between webbing taken up by the spool and the motor. The control unit has a projecting portion formed on one side thereof for collectively arranging large components. The projecting portion of the control unit is installed to be fitted into the recessed portion of the motor retractor. The rear surface of the control unit on the side opposite to the one side is substantially flat. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a seat belt device installed in a vehicle such as a passenger car, and more particularly, to a seat belt device including a motor that winds and unwinds a seat belt and a control unit that controls the motor.

  A motor retractor having a configuration in which a winding function of a webbing winding device provided in the occupant restraint seat belt device is assisted by a motor is known. This type of motor retractor, for example, reduces excessive pressure when wearing a webbing, eliminates slack by winding up the webbing during an emergency deceleration of the vehicle, etc., and increases the restraining force of the occupant to hold the body It is desired to further ensure the functions and to exhibit functions such as assisting winding and drawing when the webbing is detached.

  In order to obtain these functions, a control unit for controlling motor rotation has been conventionally attached to a vehicle as a separate body from the motor retractor. However, if the control unit is provided separately, a harness must be wired between the motor and the motor, which complicates the assembly work and generates a large amount of noise to drive the motor to control the drive. Cause various problems. For this reason, it is desirable that the control unit be arranged close to the motor.

  In order to realize this, Patent Document 1 shows an example of an apparatus in which a motor retractor and a control unit are integrated. In the belt retractor for an occupant restraint device disclosed in Patent Document 1, a frame, a belt reel (spool) rotatably mounted in the frame, and a motor and a control unit are arranged on the side surface in the spool rotation axis direction of the frame. Has been. However, in this example, since the motor and the control unit are arranged on the side surface of the frame, there is a problem that the width direction (spool rotation axis direction) of the entire seat belt device is increased. The seat belt device for the front seat is generally attached to the lower part in the pillar of the vehicle, and its mounting space is narrow. Therefore, it has been desired to reduce the size of the seat belt device in which the control unit is integrated.

JP 2001-187561 A

  The present invention is a seat belt device in which a motor drive control unit is integrated with a motor retractor, and the control unit is optimally arranged and configured, so that the size of the control unit can be reduced and the control unit can be easily mounted on a vehicle. An object is to provide a seat belt device.

To achieve the above object, the control unit integrated seat belt apparatus of the present invention, the webbing belt spool for winding a motor unit having a motor which rotates the spool capable of winding or unwinding of the webbing belt When a motor retractor having at least a power transmission mechanism for transmitting to the spool rotation torque of said motor, and a control unit for controlling rotation of the motor, the seat belt apparatus having at least, the motor retractor, the has a recess formed between said webbing belt wound up on the spool the motor unit, wherein the control unit includes a protruding portion formed on the control board cover provided on its one side, said convex portion of said control board cover, et assembled so fitted in the concave portion of the motor retractor Characterized in that was.

  In addition to the above feature, the control unit-integrated seat belt device of the present invention is characterized in that the back surface of the control unit opposite to the one side is substantially flat.

  In addition to the above features, the control unit-integrated seat belt device of the present invention includes a control board, and at least a large component mounted on the control board corresponds to the convex portion. It is characterized by being arranged in a centralized manner.

  In addition to the above features, the control unit-integrated seat belt device according to the present invention has a control board holding member for holding a control board and an outer side of the control board holding member on the opposite side of the one side of the control unit. A control unit cover mounted on the outer periphery of the control board cover, and an outer edge of the control board holding member overlaps with an outer side of the outer edge of the control board cover so as to form a minute gap with respect to an inner side of the outer edge of the control board cover. The outer edge of the control unit cover overlaps so as to form a gap, and the passage has a drip-proof function by forming a passage in which the outer shell and the two outer edges are bent.

  In the control unit-integrated seat belt device of the present invention, the mounting surface of the large circuit component of the control board is on the motor retractor side, and the position is gathered into the recess between the web wound around the spool and the motor, thereby The convex portions of the control unit can be arranged facing each other. In addition, on the outer surface (back surface) of the control unit of the control unit integrated seat belt device, a chip component such as a resistor or a diode, a relatively small component such as a connector terminal, or a component having a low height is mounted. Therefore, the entire apparatus can be formed in a shape close to a rectangle with a substantially flat shape with almost no unevenness.

  Therefore, it is possible to provide a seat belt retractor that is small and can be mounted without any trouble even in a small space below the center pillar of the vehicle, for example, with a minimum apparent thickness of the control unit. it can.

  In addition, since large parts on which the motor driving current acts are concentrated and arranged near the connector, the connection path on the control board is minimized, and the generation of noise can be suppressed.

  In addition, the control unit has a labyrinth structure around the case by the control board holding member, the control board cover member, and the control unit cover member that constitute the case, and further, the connector of the control board is at the bottom, A drip-proof function of the control board can be provided, and an inexpensive control unit can be provided with a simple configuration.

  Furthermore, since the large components on which the motor driving current acts are concentrated on the control board near the connector, the connection path with the motor is minimized, and as a result, the generation of noise generated by the motor driving current is suppressed.

  The present invention has the remarkable effects as described above.

  FIG. 1 is a connection diagram of a vehicle to which the present invention is applied and a collision safety device mounted thereon. The vehicle 112 is equipped with an obstacle sensor 102 at the front of the vehicle, and the obstacle sensor 102 outputs a signal corresponding to the distance to the obstacle existing in the front direction of the vehicle. This is transmitted to a collision determination controller 106 that is electrically connected to the sensor 102. The wheel speed sensor 104 mounted on the vehicle body outputs a signal corresponding to the speed of the vehicle, and this signal is transmitted to the collision determination controller 106 that is electrically connected to the wheel speed sensor 104.

  The collision determination controller 106 determines whether or not the vehicle 112 collides with an obstacle based on signals from the obstacle sensor 102 and the wheel speed sensor 104. When the distance from the obstacle obtained from the output signal of the obstacle sensor 102 is shorter than a predetermined value and the vehicle speed obtained from the output signal of the wheel speed sensor 104 is higher than the predetermined value, the collision is judged. The controller 106 determines that the vehicle 112 collides with the obstacle, and outputs a command signal to the brake assist device 108 and the seat belt drive controller 110 before the vehicle 112 collides with the obstacle.

  The brake assist device 108 and the seat belt drive controller 110 are electrically connected to the collision determination controller 106, and execute predetermined operations based on command signals from the collision determination controller 106, respectively. The seat belt drive controller 110 is electrically connected to the retractor 103, and controls power feeding to the retractor 103.

  FIG. 2 shows a circuit diagram of an example of a motor drive circuit used in the present invention. In the present invention, the motor drive circuit shown in FIG. 2 is mounted inside the housing of the retractor 103. The motor drive circuit includes a central processing unit (hereinafter referred to as “CPU”) 302 that controls signal processing, an H bridge including switching elements T1 to T4 that switches a power supply state to the motor 200, and a signal output from the CPU 302. The pre-driver 304 converts the signals into signals that can drive the switching elements T1 to T4.

  The D03 terminal of the CPU 302 is connected to an EN terminal that causes the pre-driver 304 to transition to an activated state (hereinafter referred to as “Enable state”). By outputting 5 V from the D03 terminal of the CPU 302, the pre-driver is enabled, and a PWM switching signal (hereinafter referred to as “PWM signal”) and a signal for switching the rotation direction (hereinafter referred to as “DIR signal”), which will be described later. The input of becomes valid.

  The D01 terminal of the CPU 302 is connected to the PWM terminal of the pre-driver 304, and a rectangular wave signal defined by a predetermined duty and frequency is output from the CPU 302.

  The D02 terminal of the CPU 302 is connected to the DIR terminal of the pre-driver 304. When 5V is input to the PWM terminal, the motor rotates in the forward direction when the D02 terminal is 5V, and the motor when the D02 terminal is 0V. Rotates in the opposite direction.

  The GT1 terminal and GT3 terminal of the pre-driver 304 are connected to the gate electrodes of the switching elements T1 and T3 on the high side of the H bridge circuit via the resistors R1 and R3, respectively. Here, since T1 and T3 are N-channel MOSFETs, the voltage of the gate electrode (hereinafter referred to as “gate voltage”) is set to the voltage of the source electrode (hereinafter referred to as “gate voltage”) in order to turn on T1 and T3. It is necessary to set it higher by about 10V than "source voltage". The pre-driver 304 has a charge pump circuit and a bootstrap circuit inside, and can output a voltage 10 V or more higher than the source voltage (voltage of the power supply 308 in the circuit of FIG. 3) to the GT1 and GT3 terminals. It has become.

  The GT2 terminal and GT4 terminal of the pre-driver 304 are connected to the gate electrodes of T2 and T4, which are low-side N-channel MOSFETs, via resistors R2 and R4, respectively.

  The resistors R1 to R4 are gate current limiting resistors. When the resistance value is increased, the gate inrush current is limited and the switching speed of T1 and T3 is reduced. Although the switching speed of T1 to T4 is related to the gate capacitance of T1... T4, in the present invention, in the N-channel MOSFET having a gate capacitance of about 3000 pF, by adopting a resistance of 100Ω to the resistors R1 to R4, A switching speed of 16 MHz is achieved.

  In the switching elements T1... T4 which are MOSFETs, parasitic diodes indicated by D1 to D4 in FIG. 2 are formed between the drain electrode and the source electrode, respectively, and the breakdown voltage is 40V to 60V. .

  In connection with the motor 200, the source electrode of T1 and the drain electrode of T2 are connected to one terminal of the motor 200. Since this motor terminal is connected to an analog input terminal (hereinafter referred to as “AN1 terminal”) of the CPU 302, the CPU 302 can monitor the motor terminal voltage. When T1 to T4 are in the OFF state, the motor terminal voltage is undefined and undefined, but by placing resistor R5 between motor 200 and power supply 308 and resistor R6 between motor 200 and GND, the motor terminal voltage Can be determined. In this embodiment, the resistors R5 and R6 are connected to terminals on different sides of the motor, respectively, for the purpose of detecting the opening of the motor terminal.

  In this embodiment, a pre-driver with dead time control developed exclusively for PWM control is used, and the output signal of the pre-driver always turns on two switching elements simultaneously, and turns on only one switching element. It is not possible. Therefore, it is possible to diagnose a failure of the power supply switch only after the motor is driven, and there is a problem that failure detection cannot be performed when the motor is stopped, that is, when the switch is open.

  Therefore, a diagnostic circuit 306 is provided for diagnosing failures in T1 to T4. A transistor T5 is mounted on the diagnostic circuit 306. The collector electrode of the transistor T5 is connected to the gate electrode of the transistor T1, and the emitter electrode of the transistor T5 is grounded. A resistor R8 is connected between the base electrode and the emitter electrode of T5, and a resistor R7 is connected between the base electrode of T5 and the D04 terminal of the CPU 302.

  Although not shown directly in FIG. 2, circuit connections similar to those described above are also configured for T2 to T4, and are respectively shown through transistors (in FIG. 2, abbreviated to overlap the transistor T5). Thus, it is an interface between the D05 to D07 terminals of the CPU 302 and the gate electrodes of T2... T4.

  FIG. 3 shows a rear view of the overall configuration of the control unit-integrated seat belt device according to the embodiment of the present invention as viewed from the control unit side. FIG. 4 is a perspective view of the overall configuration of the seat belt apparatus according to the embodiment of the present invention shown in FIG. Furthermore, FIG. 5 shows a part on the control unit side of the cross-sectional view taken along the line AA in FIG. FIG. 6 is an exploded perspective view of the seat belt device according to the embodiment of the present invention.

  As shown in FIGS. 3, 5, and 6, a connector 33a mounted on a control board 33 is disposed below the control unit 30, and a connector A22 of a harness 21a is fitted to the connector 33a. The other end of the harness 21a is connected to a power source from the vehicle and an input signal connection connector B23.

  The connector B23 is fixed to the side surface of the motor retractor 10 (in the embodiment, the motor power transmission mechanism 16), and the connector B23 is inserted and removed in the front (indoor side) direction when the control unit integrated seat belt device is mounted on the vehicle. Arranged in the same direction. Further, the connector A22 is connected to a power supply terminal (not shown) of the motor unit 20 by a harness 21b. In this embodiment, the connector 33a is arranged on the control board 33, but the harnesses 21a and 21b may be directly connected to the control board 33 without arranging the connector.

  As shown in FIGS. 5 and 6, the control unit 30 includes a control board 33, a control board holding member 31, a control unit cover 32, a control board cover 34, and screws 35 that fasten and fix the constituent members. It is configured. In addition, the control board holding member 31 and the control unit cover 32 are provided with flat surfaces parallel to the control board 33 that are in contact with each other at the peripheral portions thereof, and both of them are fixed by, for example, resistance welding or adhesion. It is integrated into one component configuration. In addition, in FIG. 6, the state before integration of these both components is shown.

  Further, the control unit cover 32 is provided with a frame that rises in a box shape, and a fixed portion 32a that extends a part of the frame and fixes the entire control unit 30 to the motor retractor 10 is provided. . The frame raised in a box shape constitutes an outline (see FIG. 5) positioned further outside the outline of the control board cover 34.

  The control board holding member 31 has a convex part 31a and a lower wall 31b. The control board 33 is inserted into the control board holding member 31 by fitting with the concave parts 33e and 33f provided on the control board 33. In doing so, the positioning is performed.

  A connector 33a is disposed at the end of the control board 33, and large components such as a capacitor 33b, a choke coil 33c, and a relay 33d are disposed in close proximity, and a motor drive current control IC is integrated and mounted. The path through which a large current for driving the motor flows is the shortest. The control board 33 is mounted with other semiconductor components and the like constituting the CPU and various input processing circuits. On the back surface on the control board holding member 31 side opposite to the large component mounting surface, FIG. As shown in FIG. 10, since chip components such as resistors and diodes, relatively small components such as connector terminals, components with low height, and the like are mounted, the shape is substantially flat with almost no unevenness. Therefore, when the control unit 30 is attached to the motor retractor 10, the apparent thickness of the control unit is minimized as shown in FIG. Can also be attached.

  As shown in FIG. 5, the control board cover 34 is formed in a concavo-convex shape corresponding to the concavo-convex shape of the parts mounted on the front (indoor) direction side when the control board 33 is mounted on the vehicle, and the control board cover 34 is controlled. It is a box-like shape that covers the outer surface side of the outer surface of the substrate holding member 31, and the inner surface that is fixed by the screw 35 or the like coincides with the surface of the control circuit substrate 33.

  7 and 8 show examples of mounting the seat belt device on a vehicle. FIG. 7 is a view of the right side of the front seat, and FIG. 8 is a view of the left side of the front seat as viewed from the indoor side.

  On either the left or right side of the front seat of the vehicle, the control unit-integrated seat belt device 1 is fixed to a mounting portion 101 below the center pillar 100 of the vehicle, for example, with a bolt, and the webbing 19 is pulled out upward. Or wound downward. The control unit 30 (in FIG. 7 and FIG. 8, on the back side of the motor retractor 10) is an input signal from the vehicle (a forward monitoring device that detects the distance to the vehicle and obstacle ahead, a brake sensor, and a collision determination controller). And a function of controlling the winding and rewinding of the webbing by driving the motor according to a driving mode stored in advance by a signal from a webbing buckle device or the like.

  When the motor retractor shown in FIGS. 7 and 8 is mounted on the vehicle, the control unit 30 is disposed from the spool 12 to the motor unit 20 as shown in FIG. In addition, the motor power transmission mechanism unit 16 is fixed to the case of the control unit cover 32 with a screw 24, for example, via a fixing unit 32a.

  As described above, when the control unit-integrated seat belt device is mounted on a vehicle, as shown in FIG. 5, the control board cover 34 is formed at the front end of the outer wall of the control board holding member 31 surrounding the outer periphery of the control board 33. The tip of the inner wall of the control unit cover 32 overlaps with a small gap (which cannot be clearly shown in FIG. 5), and on the outer side, as shown clearly in FIG. Since these three members form a labyrinth seal structure by adopting a cover-over configuration, the drip-proof function can protect the control circuit board 30 against water drops falling from the top (upper in FIG. 5). Have Therefore, it is possible to omit providing a sealing means such as providing a sealing material as a separate member or using an adhesive between these three members.

  On the control board 33, a large component with a high component height is mounted on the surface on the motor retractor 10 side, and a relatively small component with a low component height is mounted on the back surface of the control unit 30. The control substrate holding member 31 side can be flat. Further, the large component mounted on the surface of the control board 33 on the side of the motor retractor 10 is the webbing 19 wound on the spool 12 of the motor retractor 10 (FIG. 5 shows a state at the time of maximum winding). And the motor unit 20 (FIG. 5 shows the position of the cylindrical outline), the control unit 30 can be arranged close to the motor retractor 10. it can.

  The control unit-integrated seat belt apparatus configured as described above effectively utilizes the non-occupied space of the motor retractor and eliminates the unevenness on the outside of the vehicle when integrating the control unit 30 with the motor retractor 10. By configuring the control unit, the overall shape of the control unit-integrated seat belt device can be reduced to a substantially rectangular parallelepiped shape. As a result, the installation work of the harness connecting the motor and the control unit with the integrated control unit is omitted, noise is prevented by flowing a large current through the harness, and the degree of freedom of installation in the vehicle interior is increased. It is possible to realize simplification of the mounting work, effective use of the interior space of the vehicle, improvement of handleability when the seat belt device is packed and transported, and the like.

  The control unit-integrated seat belt apparatus of the present invention is suitably used for a control unit-integrated seat belt apparatus in which a motor retractor is provided in a motor retractor configured to assist the winding and withdrawal of a webbing by a motor. can do.

FIG. 1 is a connection diagram of a vehicle to which the present invention is applied and a collision safety device mounted thereon. FIG. 2 shows a circuit diagram of an example of a motor drive circuit used in the present invention. FIG. 3 shows a rear view of the overall configuration of the control unit-integrated seat belt device according to the embodiment of the present invention as viewed from the control unit side. FIG. 4 is a perspective view of the overall configuration of the seat belt apparatus according to the embodiment of the present invention shown in FIG. FIG. 5 shows a part on the control unit side of the sectional view taken along the line AA in FIG. FIG. 6 is an exploded perspective view of the seat belt device according to the embodiment of the present invention. FIG. 7 shows an example in which the seat belt device is mounted on a vehicle, and is a view of the right side of the front seat as viewed from the indoor side. FIG. 8 shows an example in which the seat belt device is mounted on a vehicle, and is a view of the left side of the front seat as viewed from the indoor side. FIG. 9 is a perspective view of the back surface (other side) of the control board. FIG. 10 is a plan view of the back surface (other side) of the control board.

Explanation of symbols

1 Control unit integrated seat belt device
10 Motor retractor
11 frames
12 Spool
13 Locking mechanism
14 Acceleration detector
15 Pretensioner section
16 Motor power transmission mechanism
17 Return spring
18 stays
19 Webbing
20 Motor section
21a harness
21b harness
22 Connector A
23 Connector B
24 screws
30 Control unit
31 Control board holding member
32 Control unit cover
33 Control board
33a connector
33b capacitor
33c choke coil
33d relay
34 Control board cover
35 screws
100 center pillar
101 Retractor mounting
102 Obstacle sensor
103 Retractor
104 Wheel speed sensor
106 Collision judgment controller
108 Brake assist device
110 Seat belt drive controller
112 vehicles
200 motor
302 CPU
304 pre-driver
308 power supply

Claims (4)

A spool for winding a webbing belt;
A motor unit having a motor which rotates the spool capable of winding or unwinding of the webbing belt,
A motor retractor having at least a power transmission mechanism for transmitting to the spool rotation torque of said motor,
A control unit for controlling the rotation of the motor;
In at least a seat belt device having:
The motor retractor has a recess formed between the taken-up the webbing belt to the spool and the motor unit,
The control unit has a convex portion formed on a control board cover provided on one side thereof,
The control unit-integrated seat belt device, wherein the convex portion of the control board cover is assembled so as to fit into the concave portion of the motor retractor. The apparatus of claim 1, wherein
The control unit-integrated seat belt apparatus according to claim 1, wherein a back surface of the control unit opposite to the one side is substantially flat. The apparatus according to claim 1 or 2,
The control unit includes a control board, and at least large components mounted on the control board are arranged in a concentrated manner in a region corresponding to the convex portion. The apparatus of claim 1 , wherein
The opposite side of the one side of the control unit includes a control board holding member for holding a control board and a control unit cover mounted on the outside of the control board holding member,
The outer edge of the control board holding member overlaps so as to form a minute gap with respect to the inner side of the outline of the control board cover, and the control unit cover so as to form a gap with respect to the outer side of the outline of the control board cover. A control unit-integrated seat belt device, wherein the outer edge of the control unit overlaps to form a passage in which the outer shell and the two outer edges are bent, whereby the passage has a drip-proof function.

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