JPH0547007Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention moves the webbing in response to opening and closing of vehicle doors, etc., so that the webbing can be placed in a position where the occupant is restrained or a position where the occupant is not restrained. The present invention relates to a passive type seat belt, and particularly to a drive device for moving the webbing.

[Prior art and its problems]

The above-mentioned passive seat belt generally has a guide rail arranged inside the vehicle, a webbing holding member that is movable along the guide rail, and the middle part of the webbing is inserted through the webbing holding member. Or, by attaching the end of the webbing, the webbing is moved by moving the webbing holding member along the guide rail, so that the webbing can be placed in a position where the occupant is restrained or a position where it is not restrained. It is something. In order to move the webbing, such a passive seat belt includes a drive device having a strip connected to a webbing holding member and a motor for driving the strip.

By the way, typical drive devices for conventional passive seatbelts are disclosed in Japanese Utility Model Publication No. 52-27470, Japanese Utility Model Application Publication No. 76156-1987, and Japanese Utility Model Application Publication No. 1988-1989.
Each of these is described in Publication No. 30553.

Of these, Publication No. 52-27470 (first publication)
In the method described in , the base end of a strip of synthetic resin wire is fixed to the smallest diameter part of a truncated conical winding drum, and the rotational force from a motor is transmitted to the drum by frictional coupling to rotate the drum. This allows the wire to be fed out from the main body.

Further, in the method described in Japanese Utility Model Application Publication No. 57-76156 (second publication), the base end of a strip having a rectangular cross section is fixed to a rotating body having a groove portion around which the strip is wound.
By rotating this rotating body with a motor, the strip is fed out from the casing.

Furthermore, Utility Model Application No. 58-30553 (3rd publication)
In the method described in , the proximal end of the resin tape is fixed to a rotating body with a plurality of protruding teeth on the outer circumferential surface, and the resin tape is rotated one by one through a large number of openings arranged in a row in the longitudinal direction. The resin tape is fed out from the rotating body by winding the rotating body so as to fit into the teeth of the body and rotating the rotating body with a motor.

However, the devices described in each of the above-mentioned publications are difficult to use because the strips are not fed out and wound up at a constant speed, and because the devices are relatively large, they can be used inside the body at the bottom of the shoulder anchor point, or at the door. There has been a problem in that the mounting location of the passive seat belt as a drive device is restricted, as it can be mounted in various locations such as inside the vehicle, next to the front dart board, and inside the rear body.

In addition, in the first publication, frictional force acts between the wire introduction part of the main body, the winding drum, and the wire, so that the wire slips and becomes unstable when the wire is paid out and taken up. Because of this, there was a risk that the running speed of the wire would change suddenly or that the wire would get caught.

Furthermore, in the case of the second publication, there is no problem when winding up the strip, but when the strip is unwound, the strip loosens due to its elastic restoring force as the rotating body rotates and bulges out to the outer periphery of the rotating body. There was a problem in that the strips would get caught on the inner peripheral surface of the casing, making it difficult to feed out.

In order to overcome this problem in the second publication, in the third publication, the teeth protruding from the rotating body are fitted into the holes of the resin tape to form a strip. prevents loosening. However, in this third publication, in order to ensure that the holes in the resin tape wound around the rotating body fit into the teeth of the rotating body, the intervals between the holes in the resin tape must be adjusted in the direction in which the resin tape is fed out. The resin tape had to be gradually widened toward the tip, making the manufacturing process of the resin tape complicated and increasing the cost. In addition, in the third publication, since the resin tape is fed out and wound up while being pressed against the rotating body by the pressing member, power loss due to sliding friction between the pressing member and the resin tape is large. There was a problem.

[Purpose of invention]

The present invention overcomes the problems of the conventional ones described above, and provides a driving device for a passive seat belt that can unwind and rewind a strip at a constant speed and stably, and can be manufactured at a low cost. The purpose is to

[Summary of the idea]

The present invention provides a drive device for a passive seat belt that includes a strip connected to a webbing holding member of a seat belt and a motor for driving the strip, in which the strip is made of a flexible material. A rotating storage cylinder is formed by a rack, and a driving gear rotationally driven by the motor is meshed with the resin rack, and the resin rack is helically pressed against the inner surface of the rack to accommodate the rotary storage cylinder, which is driven by the movement of the resin rack. It is characterized by being rotatably provided so that it can be rotated.

[Example of idea]

The present invention will be explained below with reference to embodiments shown in the drawings.

1 and 2 show the entire driving device for a passive seat belt according to the present invention, and this driving device 1 has a casing 2 and a gear casing 3 that are adjacent to each other. The casing 3 has a shape in which a large diameter portion 3A and a small diameter portion 3B are concentrically connected. Further, the casing 2 has a cylindrical shape as a whole, and an opening 3C formed in a large diameter portion 3A at the base end of the gear casing 3 faces one end wall 4 of the casing 2. A bracket 6 is provided on the outside of the upper part of the small diameter portion 3B on the tip side of the gear casing 3, and a motor 7 is attached to the bolt 8 on the bracket 6.
It is installed vertically. Rotating shaft 9 of this motor 7
extends inside the small diameter portion 3B of the gear casing 3, and its base end is supported by a bearing (not shown), and a worm 11 is fitted onto the rotating shaft 9.

A support shaft 12 extending in a direction perpendicular to the rotating shaft 9 of the motor 7 is fixedly disposed inside the gear casing 3, and the tip of the support shaft 12 is connected to the end wall of the casing 2. 4. A bearing 13 is rotatably fitted on the outer periphery of the support shaft 12, and a rotating body 14 that can rotate integrally with the bearing 13 is fitted on the outer periphery of the bearing 13. A worm wheel 15 that meshes with the worm 11 is formed at an end of the rotary body 14, and a worm wheel 15 is formed at the other end of the rotary body 14 inside the large diameter portion 3A of the gear casing 3. A drive gear 16 facing near the circumferential surface is formed. This drive gear 16 is connected to a resin rack 17 which will be described later.
The resin rack 17 is driven in the feeding direction and the winding direction through the guide port 3D formed in the large diameter portion 3A of the gear casing 3. A guide member 18 is provided for stably driving the resin rack 17 by the drive gear 16. This guide member 18 has a pair of guide gears 20, 20 rotatably supported by a guide pin 19 attached to the end wall 4 of the casing 2 and the gear casing 3 so as to extend parallel to the support shaft 12. and each guide gear 20 is connected to the drive gear 16.
It meshes with the axial end of. Further, each guide gear 20 is formed to protrude in the direction of the adjacent guide gear 20 and has a guide surface 21 having an arcuate cross section.
1 is joined to the resin rack 17, thereby stably engaging the resin rack 17.

A counter gear 22 that rotates integrally with the bearing 13 is protruded from the tip of the bearing 13, and the counter gear 22 is connected to the casing 2.
The counter gear 22 extends into the casing 2 through an opening 23 formed in the end wall 4, and a tooth portion 22A is formed at the end of the counter gear 22 on the casing 2 side. A large-diameter annular shaft 24 protruding from the end wall 4 of the casing 2 faces inside the casing 2, and the annular shaft 24 has slits 25, 25... is formed.
On the other hand, an opening 26 is formed in the casing 2 on the end surface opposite to the end wall 4, and this opening 26 is covered by a lid 27 so as to be openable and closable. A projection 28 protruding from the lid 27 fits into the annular shaft 24 and each slit 25 to position the lid 27. moreover,
An internal gear 29 is rotatably fitted to the annular shaft 24, and although not shown, the internal gear 29 meshes with the counter gear 22. Therefore, the rotation of the counter gear 22 causes the internal gear 29 to rotate at a reduced rotation speed, but the rotation speed of the internal gear 29 is one rotation even if the resin rack 17 is driven to the maximum. The reduction ratio with the counter gear 22 is set as follows. Furthermore, a protrusion 30 is provided on one end surface of the outer periphery of the internal gear 29, as shown in detail in FIGS. Accordingly, the actuator 32A of the micro switch 32 mounted on the pedestal 31 formed on the outside of the end wall 4 of the casing 2 can be contacted. This micro switch 32
is for stopping the motor 7 at the limit of feeding out the resin rack 17. A cylindrical rotary storage cylinder 34 for storing the resin rack 17 in a spiral manner on the inner circumferential side is rotatably disposed in the casing 2 at a position close to the peripheral wall 33 of the casing 2. A stopper 35 for preventing the resin rack 17 from sliding against the lid 27 is integrally formed at the end of the cylinder 34 on the lid 27 side. Further, on the outer circumferential side of the rotary storage cylinder 34, a rotation storage cylinder 34 that is connected to the peripheral wall 33 of the casing 2 is provided.
Lubricants such as grease are supplied to ensure smooth sliding. Furthermore, this rotating storage cylinder 34
As is clear from FIG. 1, the drive gear 16
The resin rack 17 that has passed between the drive gear 16 and the guide member 18 is wound up spirally through an opening (not shown) formed in the end wall 4. In addition, resin rack 1
Since the base end of 7 is sequentially shifted in the axial direction of the rotation storage tube 34, it is not fixed to the rotation storage tube 34 and is left in a free state.

As shown in detail in FIGS. 4A and 4B, the resin rack 17 has a long main body 36 made of flexible synthetic resin, and this main body 36 has a cylindrical surface 37 and a flat surface 38. It has a substantially semicircular cross section, and a reinforcing wire body 39 is embedded inside. On the plane 38 of the main body 36, the drive gear 16 is disposed.
Chevron-shaped teeth 40, 40, .
The curved surface is smoothly connected to the cylindrical surface 37 of.
Therefore, the cross section of the toothed portion 40 of the resin rack 17 is approximately circular, and the resin rack 17 has the following shape.
It has a substantially cylindrical shape except for the grooves 43, 43, . . . between the teeth 40, 40. This is resin rack 17
This is to make it three-dimensionally deformable.

A webbing holding member (not shown) is attached to the tip of the resin rack 17 exposed to the outside of the gear casing 3, and this webbing holding member is attached to a guide rail arranged three-dimensionally inside the vehicle. The resin rack 17 moves inside the resin rack 17 as it is fed out from the drive device 1 and taken up. Webbing is attached indirectly or directly to the webbing holding member, and as the webbing holding member moves along the guide rail, the webbing moves toward and away from the seat, and is placed in a position where the occupant is restrained. and an unrestrained position. In addition, a micro switch (not shown) faces the end of the guide rail close to the drive device 1, and the maximum winding position of the resin rack 17 when the webbing holding member reaches the end of the guide rail is controlled. The motor 7 is stopped at .

Next, the operation of the embodiment described above will be explained.

As shown in FIG. 1, in order to unwind the resin rack 17 from the state where the resin rack 17 is housed in the rotary storage cylinder 34 in the maximum spiral shape, the motor 7 is driven by a signal such as the opening/closing of a vehicle door. Then, the rotating body 14 is rotated clockwise in FIG. 2 via the worm 11 and the worm wheel 15. Then, the cylindrical surface 37 on the back becomes the guide member 18.
The resin rack 17, whose teeth 40 are accurately meshed with the drive gear 16 while being guided by the guide surfaces 21, 21 of the guide gears 20, 20, is shown by arrow A.
A webbing holding member (not shown) is moved along a guide rail to move the webbing. In this manner, when the resin rack 17 is fed out, the rotary storage tube 34 is rotated by the frictional force of the resin rack 17 which is in pressure contact with the rotation storage tube 34 due to its elasticity, and the rotation storage tube 34 is rotated. Resin rack 1 stored in 34
7 gradually moves closer to the drive gear 16. As described above, the resin rack 17 is fed out and moved along the three-dimensionally arranged guide rails, and the webbing holding member is moved until the webbing holding member reaches the final position, that is, the feeding limit of the resin rack 17. When reaching , the internal gear 29 meshing with the counter gear 22 rotating together with the rotating body 14 rotates nearly 360 degrees from the initial position, and the protrusion 30 of the internal gear 29 engages the actuator 32A of the micro switch 32. come into contact with. Then, the signal from this microswitch 32 is transmitted to the motor 7, and the drive of the motor 7 is stopped.
In this state, the webbing connected to the webbing holding member is in a position where the occupant is not restrained or restrained.

On the other hand, in order to wind up the resin rack 17 onto the rotary storage cylinder 34 from the maximum unwinding position of the resin rack 17 described above, the motor 7 is driven in the opposite direction to the direction in which the resin rack 17 is unwinded. Rotate counterclockwise in Figure 2. Then, the resin rack 17 held from the back side by the guide member 18 and accurately meshed with the drive gear 16 is wound up in the direction of arrow B, and the rotating storage cylinder 34 is rolled up by the frictional force.
are sequentially and spirally stored on the inner circumferential surface of the rotary storage tube 34 as they are rotated. As a result, the webbing holding member moves along the guide rail to move the webbing. And resin rack 17
When the winding reaches the maximum winding position, a micro switch (not shown) is placed facing the guide rail.
is energized and stops driving the motor 7.

As described above, according to this embodiment, the guide member 18
Since the resin rack 17 held by the drive gear 16 accurately meshes with the drive gear 16, the resin rack 17 can run stably. 16
It is easy to use because it is fed out or wound up while traveling at a constant speed. In addition, resin rack 1
7 is housed in a spiral shape on the inner circumferential surface of the rotary storage tube 34 that rotates freely, so the drive device 1 can be made compact and can be installed at various positions in the vehicle. Furthermore, the device of this embodiment does not have any particularly complicated structure and has a small number of parts, so it can be manufactured at low cost. Furthermore, since the resin rack 17 has a generally cylindrical shape as a whole, it can be deformed (bent) three-dimensionally, and can therefore follow any shape of guide rail. In addition, the micro switch 32 for the feeding limit of the resin rack 17 is not provided at the tip of the guide rail, and the drive device 1
Since it is provided in the same direction, the wiring length can also be shortened.

[Effect of idea]

As explained above, according to the present invention, it is possible to unwind and wind up the resin rack as a strip at a constant speed and stably, and moreover, it has the practical effect of being able to be manufactured at low cost.

[Brief explanation of drawings]

Fig. 1 is a partially longitudinal sectional front view showing an embodiment of a passive seat belt drive device according to the present invention, Fig. 2 is a partially longitudinal sectional side view of Fig. 1, and Figs. 3 A and B.
1 and 2 are a front view and a right side view of the internal gear, and FIGS. 4A and 4B are an enlarged front view and a sectional view of the main parts of FIGS. 1 and 2. DESCRIPTION OF SYMBOLS 1... Drive device, 2... Casing, 3... Gear casing, 7... Motor, 11... Worm, 14... Rotating body, 15... Worm wheel, 16... Drive gear, 17... Resin rack ,1
8... Guide member, 20... Guide gear, 22...
... Counter gear, 29 ... Internal gear, 32 ... Micro switch, 34 ... Rotating storage cylinder, 36 ...
Main body, 37... Cylindrical surface, 38... Plane, 39...
Reinforcement wire body, 40... tooth portion, 43... groove portion.

Claims (1)

[Claims for Utility Model Registration] 1. A drive device for a passive seat belt comprising a strip connected to a webbing holding member of a seat belt and a motor for driving the strip, which allows the strip to be moved. A rotary storage cylinder is formed of a flexible resin rack, and a driving gear rotationally driven by the motor is meshed with the resin rack, and the resin rack is helically pressed against the inner surface of the resin rack to accommodate the rotary storage cylinder. 1. A drive device for a passive seat belt, characterized in that it is rotatably provided so as to be able to rotate according to the movement of the seat belt. 2. The passive seat belt drive device according to claim 1, which is provided with a guide member that meshes with the drive gear and holds the resin rack from the back side. 3. The drive device for a passive seat belt according to claim 1 or 2, wherein the rotation storage tube is provided close to the drive gear. 4. The drive device for a passive seat belt according to claim 1, 2 or 3, wherein the resin rack has a substantially circular cross section and can be bent three-dimensionally. .