JP2009226970A - Seat belt winding unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seat belt winding unit enabling to accurately execute winding control while minimizing cost and labor required for wiring. <P>SOLUTION: The seat belt winding unit 10 comprises a seat belt winding device 15, and a seat belt ECU 50 for controlling the tension of a webbing. The seat belt winding device 15 has a spool 16 to which one end of the webbing is fixed, a motor 45 for generating driving force, a gear mechanism 35 for transmitting the driving force generated by the motor 45 to the spool 16, and a holding member 20 for holding theses and fixing them to a vehicle. The holding member 20 has a spool supporting portion 25, a motor supporting portion 26, and a fixing portion 27 integrally formed in sequence from the upper part to the lower part. The fixing portion 27 is formed as a plate-like site protruded from the motor supporting portion 26. On the fixing portion 27, the seat belt ECU 50 is installed in no contact with the motor 45. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a seat belt winding unit for controlling webbing tension.

  Conventionally, when it is determined that the possibility of collision between the own vehicle and an obstacle existing on the traveling path of the own vehicle (hereinafter referred to as collision possibility) is equal to or greater than a threshold value, the pre-strengthening force for restraining the seat belt is increased. Crash safety systems are known.

  This pre-crash safety system has a monitoring device (for example, a millimeter wave radar device) that monitors the traveling path of the host vehicle, a seat belt winding device for winding a webbing that is a belt of a seat belt, and a possibility of collision. If an electronic control device (so-called ECU, hereinafter referred to as a pre-crash ECU) that determines whether or not the threshold is equal to or greater than the threshold and the result of determination by the pre-crash ECU indicates that the collision possibility is equal to or greater than the threshold, the tension is defined in advance. And an electronic control unit (hereinafter referred to as a seat belt ECU) that performs winding control for winding the webbing so that the target value is achieved.

  Among these, the seat belt retractor includes a spool with one end of the webbing fixed, a motor that generates a driving force for rotating the spool, a gear group that transmits rotation of the motor to the spool, a spool and a motor. And a support mechanism for fixing the gear group to the vehicle. The seat belt retractor is disposed in each of the center pillars (so-called B pillars) of the vehicle in order to restrain the passengers seated in the driver's seat and the passenger seat of the vehicle to the seat.

  The seat belt ECU includes a switching unit provided in the energization path and a known microcomputer having at least a CPU for controlling the switching unit in order to conduct and block the energization path to the motor. .

  Since the seat belt ECU controls the seat belt retractor for each of the driver's seat and the passenger seat with one ECU, the seat belt ECU is separated from at least one of the two seat belt retractors installed in each center pillar. It will be installed in a different position. For example, when the seat belt ECU is installed at the center in the vehicle width direction of the vehicle, the distance between the seat belt ECU and the seat belt retractor is larger than when the seat belt ECU is installed in the vicinity of each center pillar. become longer.

  For this reason, in the conventional pre-crash safety system, there is a problem that the lead wire connecting the motor and the seat belt ECU becomes long and costs increase, and it takes time to wire the lead wire.

In order to solve this problem, it has been proposed that the seat belt ECU is constituted by a one-chip IC and the one-chip IC (that is, the seat belt ECU) is mounted on each seat belt retractor (for example, Patent Document 1).
JP 2001-199309 A

  However, as described in Patent Document 1, even if the one-chip IC is mounted on the seat belt retractor, if the seat belt ECU and the motor are arranged so as to be in contact with each other, the influence of heat generation or noise from the motor Therefore, there is a problem that the seat belt ECU cannot receive the seat belt winding control accurately.

On the other hand, if the distance between the seat belt ECU and the motor is too large, the wiring becomes long and the problem of increased cost and labor remains.
In other words, depending on the positional relationship between the seat belt ECU and the motor, there are problems that conventional problems cannot be solved and webbing winding control cannot be executed accurately.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a seat belt winding unit capable of accurately performing winding control while reducing the cost and labor required for wiring as much as possible.

  In the present invention made to achieve the above object, one end of a webbing is fixed, a spool for winding the webbing, a motor for generating a driving force in accordance with an input driving signal, and the spool rotate. A gear mechanism for transmitting the driving force generated by the motor to the spool, a seat belt retractor having a holding member that supports them (spool, motor, and gear mechanism) and is fixed to the moving body; A seat belt winding unit including a control device that generates and outputs a drive signal so that the tension becomes a prescribed target value.

And in the seatbelt winding unit of this invention, a control apparatus is arrange | positioned in the attachment position which becomes non-contact with a motor on a seatbelt winding apparatus.
According to such a seat belt winding unit of the present invention, since the control device and the motor are not in contact with each other, it is possible to reduce the influence of heat generated from the motor and noise generated by the motor. Control can be executed more reliably.

  Furthermore, according to the seat belt winding unit of the present invention, since the control device and the motor are a set of units, it can be controlled to a target value in consideration of the characteristics of each motor and the characteristics of each control device, As a result, a control error can be suppressed.

The non-contact position mentioned here means that the motor and the control device do not directly contact each other, and does not include contact via another member.
By the way, a general holding member includes a spool support portion that rotatably supports the spool, a motor support portion that is integrated with the spool support portion, supports the motor, and a plate-like member that protrudes from the motor support portion. And a fixing portion for fixing the seat belt retractor to the moving body.

And when a holding member is comprised in this way, it is desirable for the attachment position in the seatbelt winding unit of this invention to be provided on the fixing | fixed part.
In such a seat belt winding unit of the present invention, it is only necessary to dispose the control device on the fixed portion in the conventional seat belt winding device, so there is no need to change the structure of the seat belt winding device. Therefore, the above-described effects can be obtained without increasing the cost more than necessary.

  In particular, according to the seat belt winding unit of the present invention, the motor and the control device can be brought closer to each other compared to a conventional general seat belt winding unit. As a result, according to the seat belt winding unit of the present invention, the conducting wire between the motor and the control device can be shortened.

  In addition, when the motor support part is formed as a thing larger than the diameter of a motor, a control apparatus and a motor will be non-contact only by installing a control apparatus in a fixing | fixed part. Accordingly, in this case, the attachment position of the control device may be determined so as to come into contact with the motor support portion.

  On the other hand, when the motor support portion is formed to be smaller than the motor diameter, the motor supported by the motor support portion protrudes from the motor support portion. Therefore, in this case, it is desirable that the mounting position is determined at a position away from the motor support portion.

Note that the substrate in the present invention is preferably formed of a metal material.
According to the seat belt winding unit of the present invention using such a substrate, since the control device is disposed in the fixing portion formed of a metal material, the control device can be operated by causing the fixing portion to function as a heat sink. The generated heat can be radiated efficiently. As a result, according to the seat belt winding unit of the present invention, the seat belt winding control can be more reliably executed.

  By the way, the holding member is configured to include a substrate portion formed in a band plate shape and two support pieces arranged at positions on the substrate portion facing each other so as to support the spool and the motor. There are many.

  When the holding member is configured as described above, a general gear mechanism is composed of a plurality of gears including a first gear to which the driving force generated by the motor is directly transmitted, and the opposing surfaces (that is, the supporting pieces) , Support surfaces) each configured to include a gear group installed on a surface (that is, an outer surface) opposite to each other, and a case that has an installation surface that is parallel to the outer surface and covers the gear group. Has been.

  And when a gear mechanism is comprised in this way, the attachment position in the seatbelt winding unit of this invention may be provided on the extension line of the rotating shaft of the 1st gear in an installation surface.

  In such a seat belt winding unit of the present invention, the seat belt can be simply installed on the extension line of the rotation shaft of the first gear on the installation surface of the gear mechanism in the conventional seat belt winding device. There is no need to change the structure of the winding device. Therefore, the above-described effects can be obtained without increasing the cost more than necessary.

  In particular, according to the seat belt winding unit of the present invention, it is possible to install the motor and the control device closer to each other as compared with a conventional general seat belt winding unit. As a result, according to the seat belt winding unit of the present invention, the conducting wire between the motor and the control device can be shortened.

  Note that the case is preferably formed of a resin material.

Embodiments of the present invention will be described below with reference to the drawings.
<overall structure>
First, FIG. 3 is a block diagram showing a schematic configuration of a pre-crash safety system including a seat belt winding unit to which the present invention is applied.

  This pre-crash safety system 1 increases the braking force of the host vehicle or increases the braking force of the seat belt when there is a high possibility of a collision between the obstacle on the traveling path and the host vehicle (hereinafter referred to as a collision possibility). Strengthens the binding force.

  In order to realize this, the pre-crash safety system 1 is configured according to the output from the front monitoring device 5 that monitors the traveling path of the host vehicle, the brake control device 7 that controls the brake mechanism of the host vehicle, and the front monitoring device 5. The electronic control device (so-called ECU, hereinafter referred to as pre-crash ECU) 6 that controls whether or not the collision possibility is equal to or higher than a set threshold and controls the brake control device 7 according to the determination result, and the pre-crash ECU 6 When it is determined that the possibility of collision is equal to or greater than the set threshold value, the seat belt retracting unit 10 that strengthens the restraining force of the seat belt is provided.

  Among these, the forward monitoring device 5 detects a target such as a preceding vehicle by transmitting and receiving a radar wave, and acquires target information including the position and speed of the target and the host vehicle. The apparatus is mainly configured by an apparatus and the like, and the acquired target information is output to the pre-crash ECU 6. The forward monitoring device 5 is arranged so as to capture the traveling direction of the host vehicle, and an in-vehicle camera that acquires target information based on the captured image, or a target such as a preceding vehicle by transmitting and receiving laser light. It may be configured centering on a laser radar device that detects the target and obtains target information, or may be configured by combining these (that is, millimeter wave radar, in-vehicle camera, and laser radar device).

  The pre-crash ECU 6 is configured around a known microcomputer including at least a CPU, a ROM, a RAM, and a bus connecting them. Then, the pre-crash ECU 6 calculates the collision possibility according to the target information acquired from the front monitoring device 5, notifies the calculated collision possibility in the own vehicle, and the calculated collision possibility is It is determined whether or not the threshold value is equal to or higher than a first threshold value that is defined in advance as one of the setting threshold values. A process for increasing the braking force of the vehicle is executed. In addition to this, the pre-crash ECU 6 determines whether or not the possibility of collision is greater than the first threshold value and is equal to or greater than a second threshold value that is defined in advance as one of the setting threshold values. As a result, if the possibility of collision is equal to or greater than the second threshold value, a determination result output process for outputting a collision determination result indicating that the possibility of collision is equal to or greater than the second threshold value is executed for the seat belt retracting unit 10. Has been.

<Seat belt take-up unit>
Next, the seat belt winding unit will be described.
FIG. 1 is a perspective view showing a schematic configuration of a seat belt winding unit.

  The seat belt retracting unit 10 constitutes a part of a seat belt mechanism for restraining a person (hereinafter also referred to as drivers) seated in a driver seat and a passenger seat provided in an automobile to the seat. A belt band (hereinafter referred to as webbing) can be pulled out and wound.

The seat belt retracting unit 10 is disposed in each of the center pillars (so-called B pillars) of the vehicle in order to restrain the drivers on the seats.
The seat belt retracting unit 10 is preliminarily defined when it acquires a seat belt retractor (so-called retractor) 15 for retracting the webbing and a collision determination result indicating that the possibility of collision is greater than or equal to a second threshold value. And an electronic control unit (so-called ECU, hereinafter referred to as a seat belt ECU) 50 that performs winding control for controlling the tension of the webbing so as to achieve the target value.

Here, FIG. 2 is a front view and a right side view showing a schematic configuration of the seat belt retractor. However, about FIG. 2 (A), a part of site | part is shown with the cross section and internal structure.
The seat belt retractor 15 includes a spool 16 to which one end of the webbing is fixed, a motor 45 that generates a driving force for driving the spool 16, and a gear mechanism that transmits the driving force generated by the motor 45 to the spool 16. 35 and a lock mechanism 48 for preventing the webbing from being pulled out with a force greater than a predetermined force, a spool 16, a motor 45, a gear mechanism 35, and a lock mechanism 48, and are fixed to the vehicle. And a holding member 20 for the purpose.

  In the seat belt retractor 15, the upper side shown in FIG. 2 is called the upper part, the lower side shown in FIG. 2 is called the lower part, and the vertical direction shown in FIG. 2 is called the vehicle height direction, and FIG. The left-right direction shown is called the full length direction, and the left-right direction shown in FIG. 2B is called the vehicle width direction.

  The spool 16 is a member formed of a metal material in a cylindrical shape, and one end of the webbing is fixed. However, the spool 16 has a length in the axial direction (full length direction) (hereinafter referred to as a spool width) longer than the width of the webbing and shorter than the width of the center pillar.

  The motor 45 is a well-known motor that is housed in a casing 46 made of a metal material and converts electrical energy into rotational motion (ie, kinetic energy). The motor 45 includes a power source mounted on the host vehicle by the seat belt ECU 50. When the gap is made conductive, the drive shaft rotates to generate a driving force for rotating the spool 16.

  The holding member 20 includes a spool support portion 25 that rotatably supports the spool 16, a motor support portion 26 that supports the motor, and a fixing portion 27 that fixes the seat belt retractor 15 to the center pillar. It has.

  Each part (that is, the spool support part 25, the motor support part 26, and the fixing part 27) provided in the holding member 20 is configured to support the substrate 21 formed in a band plate shape, the spool 16 and the motor 45. This is realized by the two support pieces 22 and 23 arranged at positions facing each other on the upper side. However, the board | substrate 21 and the support pieces 22 and 23 are integrally formed with the metal material (for example, chromium molybdenum steel).

  In the following description, the surfaces of the support piece 22 and the support piece 23 that face each other are referred to as opposing surfaces, and the surfaces of the support piece 22 and the support piece 23 that are opposite to the opposing surfaces are referred to as outer surfaces. In the following, among the plurality of surfaces of the substrate 21, a surface at least part of which is in contact with the center pillar when fixed to the automobile is referred to as an attachment surface, and among the surfaces of the substrate 21, The surface that becomes the passenger compartment side when fixed to the automobile is referred to as a reference surface 24.

Among these, the board | substrate 21 is integrally formed with the rectangular site | part which is a site | part formed in the rectangular shape, and the tongue piece protruded from the rectangular site | part.
The tongue piece is formed as a lower end portion of the substrate 21 having a predetermined length that is predetermined in the vehicle height direction, and is used to fix the holding member 20 (and consequently the seat belt retractor 15) to the center pillar. The fastening element (for example, countersunk screw) can be inserted, and an insertion hole 28 having a shape in which the fastening element does not protrude (that is, does not protrude) from the reference surface 24 is formed. However, the insertion hole 28 penetrates from the reference surface 24 to the mounting surface at a position where the seat belt retractor 15 is fixed to the center pillar and the rigidity is such that the holding member 20 is not deformed when the webbing is pulled out. So that it is drilled.

That is, the lower end portion of the substrate 21 is formed as the fixing portion 27.
In addition, the board | substrate 21 is formed in the vehicle height direction length (henceforth a vehicle height length) as a whole longer than the support pieces 22 and 23, and also the length (namely, board | substrate) in the full length direction. 21 (hereinafter referred to as the substrate width) is longer than the webbing and shorter than the spool width.

  On the other hand, the support piece 22 is between the first support piece 22a protruding from the upper part of the substrate 21 (more precisely, a rectangular part) and the upper part and lower part of the substrate 21 (that is, the central part, more precisely, the rectangular part). The first support piece 22a and the third support piece 22b are integrally formed. The support piece 23 is formed between the second support piece 23a protruding from the upper part of the substrate 21 (more precisely, a rectangular part) and the upper and lower parts of the substrate 21 (that is, the central part, more precisely, the rectangular part). The second support piece 23a and the fourth support piece 23b are integrally formed.

  The first support piece 22a and the second support piece 23a are made of a plate material that can rotatably support the spool 16, and project from each of a pair of sides parallel to the vehicle height direction. ing. However, in the first support piece 22a and the second support piece 23a, the protruding amount from the substrate 21 (that is, the length in the vehicle width direction, hereinafter referred to as the protruding length) is the diameter of the spool 16 (that is, the webbing is taken up). The diameter including the thickness of the webbing at the time.

  That is, the spool 16 supported by the first support piece 22a and the second support piece 23a so as to be rotatable and to cover the upper portion of the reference surface 24 has a predetermined direction (hereinafter referred to as a winding direction). The webbing is wound around the spool 16 itself, and the webbing is pulled out from the spool 16 itself by rotating in the direction opposite to the winding direction (hereinafter referred to as the pulling direction). That is, the spool support portion 25 is configured by the first support piece 22a and the second support piece 23a.

  Further, the third support piece 22b and the fourth support piece 23b are made of a plate material capable of fixing the motor 45, and project from each of a pair of sides parallel to the vehicle height direction. That is, the third support piece 22b and the fourth support piece 23b constitute a motor support portion 26 in which the motor 45 is fixed so that at least a part of the drive shaft protrudes from the outer surface and covers the central portion of the reference surface 24. ing. For this reason, the housing 45 of the motor 45 fixed to the motor support portion 26 is exposed.

  Further, in order to increase the rigidity of the holding member 20, the holding member 20 is provided with bridge pieces 29 and 30 formed in a rectangular strip shape so as to connect the support piece 22 and the support piece 23. It has been.

  As described above, the holding member 20 includes the spool support portion 25, the motor support portion 26, and the fixed portion in the direction in which the spool support portion 25, the motor support portion 26, and the fixed portion 27 are directed from the upper part to the lower part. In particular, the fixing portion 27 is made of a metal material as a plate-like portion protruding from the motor support portion.

The gear mechanism 35 includes a gear group 36 that transmits the driving force of the motor 45 to the spool 16 and a gear case 37 that houses the gear group 36.
Among these, the gear group 36 includes a first gear 38 connected to the drive shaft of the motor 45 and an n-th gear fixed to one end of the spool 16 (n is a natural number determined by the number of intermediate gears described later, 39 in this embodiment) and at least one (1 in this embodiment) intermediate gear 40 that transmits the driving force from the first gear 38 to the n-th gear 39 while changing the rotational speed. It has. These gears (that is, the first gear 38, the nth gear 39, and the intermediate gear 40) are disposed on the outer surface of the support piece 23.

  On the other hand, the gear case 37 is fixed to the outer surface of the support piece 23 and has a surface parallel to the outer surface (hereinafter referred to as an installation surface), and a storage space for storing the gear group 36 therein. Is formed.

  Further, a spring (so-called “spring”, not shown) is accommodated in the gear case 37, and this spring generates an urging force in the winding direction when the spool 16 is rotated in the pull-out direction. One end is locked to the gear case 37 and the other end is locked to the spool 16. As a result, when the pulling direction force applied to the webbing is released (for example, when the occupant removes the seat belt), the spool 16 rotates in the winding direction to wind up the webbing.

  That is, the gear mechanism 35, when the pulling direction force applied to the webbing is released (for example, when the occupant removes the seat belt), the spool 16 rotates in the winding direction and winds up the webbing. The driving force generated by the motor 45 is transmitted to the spool 16, and the spool 16 is rotated in the winding direction or the drawing direction so that the webbing tension can be adjusted.

<Seat belt ECU>
Next, the seat belt ECU will be described.
The seat belt ECU 50 includes a board circuit for controlling the motor 45 and a housing that covers the board circuit. The seat belt ECU 50 is formed in a substantially rectangular parallelepiped shape (that is, a surface on which no element is placed, hereinafter also referred to as a contact surface) (that is, one chip having a rectangular parallelepiped shape). Packaged in). However, the length of the longest side (hereinafter referred to as the longest side) of the seat belt ECU 50 is shorter than the substrate width, and the length of the shortest side (hereinafter referred to as the shortest side) is the support piece 22. , 23 has a length shorter than the protruding amount.

  As shown in FIG. 3, the board circuit is provided in an energization path from a battery (not shown) mounted on the host vehicle to the motor 45, and a switching unit 51 for conducting and blocking the energization path. And a microcomputer (hereinafter also referred to as a microcomputer) 56 that generates a motor control signal that permits conduction in the switching unit 51 and outputs the motor control signal to the switching unit 51.

  The switching unit 51 is an H-bridge circuit having four N-channel type power MOSFETs (field effect transistors). Among the four N-channel type power MOSFETs, two power MOSFETs have a microcomputer 56 at the gate. The battery is connected to the drain, the motor 45 is connected to the source, and the two power MOSFETs have the microcomputer 56 connected to the gate, the motor 45 connected to the drain, and the source grounded. That is, the switching unit 51 can switch the forward rotation and reverse rotation (that is, the winding direction or the drawing direction) of the motor 45 by switching the power MOSFET that can be energized between the drain and the source.

  The microcomputer 56 includes a ROM 57 that stores data and programs that need to be stored even when the power is turned off, a RAM 58 that stores data temporarily generated during processing, and processes stored in the ROM 57 and RAM 58. The CPU 59 is a known device including at least a CPU 59 for executing a program and a bus connecting them.

In the ROM 57, information acquisition processing for transmitting / receiving information to / from other ECUs mounted on the vehicle such as the pre-crash ECU 6 (that is, ECUs other than the seat belt ECU) and whether the operation of the seat belt ECU 21 is normal. A processing program for the CPU 59 to execute an operation confirmation process for determining whether or not is stored is stored. In addition, the ROM 57 stores a processing program for the CPU 59 to execute a motor driving process for outputting a motor control signal immediately after obtaining a collision determination result from the pre-crash ECU 6.
<Mounting position>
Next, the mounting position of the seat belt ECU will be described.

The seat belt ECU 50 is disposed at a predetermined mounting position on the fixing portion 27 of the holding member 20.
The mounting position is set so that the longest side is parallel to the full length direction of the board 21 and is within the board width after the seat belt ECU 50 is separated from the motor 45 so as not to contact the motor 45. Yes. However, the mounting position is set so that the shortest side is parallel to the vehicle width direction of the substrate 21.

Further, the attachment position is set so that the reference surface 24 on the fixed portion 27 and at least a part of the contact surface of the seat belt ECU 50 are in contact with each other.
Therefore, the seat belt ECU 50 attached to the attachment position is not in contact with the motor 45 and is accommodated in a space on the fixed portion 27 adjacent to the motor support portion 26, and the contact surface of the seat belt ECU 50 is a substrate. 21 is in contact with the reference surface 24. However, “non-contact” in the present embodiment means that the motor 45 and the seat belt ECU 50 do not directly contact each other, and does not include contact via another member.
[Effect of the embodiment]
As described above, according to the seat belt retractor unit 10 of the present embodiment, the seat belt ECU 50 and the motor 45 are installed so as not to contact each other. The influence of noise to be reduced can be reduced, and the seat belt winding control can be executed more reliably.

  According to the seat belt retractor unit 10 of the present embodiment, the seat belt ECU 50 is disposed in the fixed portion 27 adjacent to the motor support portion 26, and therefore, compared with a conventional general seat belt retractor unit. The seat belt ECU 50 and the motor 45 can be disposed close to each other. Therefore, according to the seatbelt retractor unit 10 of the present embodiment, the conductor for connecting the seatbelt ECU 50 and the motor 45 can be shortened, and the cost of the conductor and the labor for wiring the conductor are reduced. it can.

  Furthermore, if the motor 45 is not driven for a long period of time, i.e., if the state where the possibility of collision is kept low is maintained, the conductor may be deteriorated as time elapses. According to the unit 10, since the conducting wire can be shortened, deterioration of the conducting wire can be prevented to the minimum.

  Furthermore, according to the seatbelt retractor unit 10 of the present embodiment, the seatbelt ECU 50 and the motor 45 are a set of units, so that the target value is determined in consideration of the characteristics of the motor 45 and the characteristics of the seatbelt ECU 50. As a result, control error can be suppressed.

  In particular, according to the seat belt retractor 10 of the present embodiment, the seat belt ECU 50 and the motor 45 can be installed close to each other, so that the temperature of the seat belt ECU 50 and the temperature of the motor 45 are regarded as substantially the same temperature. Thus, the winding control can be executed more accurately.

That is, according to the seat belt winding unit 10 of the present embodiment, the winding control can be accurately executed while reducing the cost and labor required for wiring as much as possible.
In addition, according to the seat belt winding unit 10 of the present embodiment, the seat belt ECU 50 is disposed on the substrate 21 (that is, the fixing portion 27) formed of a metal material, and thus generated from the seat belt ECU 50. Heat can be efficiently radiated through the substrate 21. As a result, according to the seat belt retractor 10 of the present embodiment, the heat sink configured separately from the seat belt retractor 15 and the seat belt ECU 50 is not attached to the seat belt ECU 50, and the seat belt ECU 50 The temperature increase of the seat belt ECU 50 can be suppressed without increasing the circuit area (that is, the area of the substrate circuit).

That is, according to the seat belt retractor unit 10 of the present invention, the heat dissipation efficiency of the seat belt ECU 50 can be improved while suppressing the cost as much as possible.
As a result, according to the seat belt winding unit 10 of the present embodiment, the winding control can be executed more reliably.
[Other Embodiments]
As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it can implement in various aspects.

  For example, in the above embodiment, the fixing position 27 on the holding member 20 is the mounting position, but the mounting position may be on the extension line of the rotation shaft of the first gear 38 on the installation surface of the gear case 37. . That is, as long as the motor 45 and the seat belt ECU 50 are not in contact with each other and can be installed in the vicinity of the motor 45, the attachment position may be any position.

  In addition, the seat belt retractor unit 10 in the above embodiment is disposed in the center pillar, but the disposition position of the seat belt retractor unit 10 is not limited to the center pillar. You may arrange | position on the seat frame | skeleton in a passenger seat and a backseat. In particular, the seat belt retracting unit 10 for restraining a person seated in the rear seat to the seat is arranged in the seat where the shoulder of the person seated in the seat exists or on the ceiling of the own vehicle. Also good.

  Further, the seat belt ECU 50 in the above embodiment is configured with a microcomputer as the center, but the seat belt ECU 50 is configured with an electric circuit configured to obtain an equivalent function without using the microcomputer. May be.

It is a perspective view which shows schematic structure of a seatbelt control unit. It is explanatory drawing (a front view, a right view) which shows schematic structure of a seatbelt winding device. It is a block diagram which shows schematic structure of a pre-crash safety system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pre-crash safety system 10 ... Seat belt winding unit 15 ... Seat belt winding device 16 ... Spool 20 ... Holding member 21 ... Substrate 22, 23 ... Support piece 25 ... Spool support part 26 ... Motor support part 27 ... Fixed part 28 ... Insertion hole 29, 30 ... Bridge piece 35 ... Gear mechanism 36 ... Gear group 37 ... Gear case 38 ... First gear 39 ... Nth gear 40 ... Intermediate gear 45 ... Motor 48 ... Lock mechanism 50 ... Seat belt ECU 51 ... Switching unit 56 ... Microcomputer 57 ... ROM 58 ... RAM 59 ... CPU

Claims (4)

A spool for winding webbing, a motor for generating a driving force in accordance with an input driving signal, a gear mechanism for transmitting the driving force generated by the motor to the spool so that the spool rotates, the spool, A seat belt winding device having a holding member that supports the motor and the gear mechanism and fixes them to a moving body;
A seat belt winding unit comprising: a control device that generates and outputs the drive signal so that the tension of the webbing is a prescribed target value;
The control device;
A seat belt retracting unit, wherein the seat belt retracting unit is disposed at an attachment position that is not in contact with the motor on the seat belt retracting device. The holding member is
A spool support portion for rotatably supporting the spool;
A motor support portion configured integrally with the spool support portion and supporting the motor;
Formed as a plate-like member protruding from the motor support portion, and comprising a fixing portion for fixing the seat belt winding device to the movable body,
The mounting position is
The seat belt winding unit according to claim 1, wherein the seat belt winding unit is provided on the fixing portion. The fixing part is
The seat belt winding unit according to claim 2, wherein the seat belt winding unit is made of a metal material. The holding member is
A substrate portion formed in a strip shape, and
Two support pieces arranged at positions on the substrate portion facing each other so as to support the spool and the motor;
With
The gear mechanism is
Each of the opposing surfaces of the support piece is a support surface, the surface opposite to the support surface is an outer surface, and includes a plurality of gears including a first gear to which a driving force generated by the motor is directly transmitted, A group of gears installed on the outer surface;
An installation surface that is a surface parallel to the outer surface, and a case that covers the gear group;
The mounting position is
The seat belt retractor according to claim 1, wherein the seat belt retractor is provided on an extension line of a rotation shaft of the first gear on the installation surface.

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