JPH0314445Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a pressure relief device for a seat belt retractor of an automobile, etc., and relates to a ratchet structure in the pressure relief device.

FIGS. 1 and 2 show an example of a conventional retractor pressure relief device. 1 is the main body of the retractor, which includes a bottom plate 2 and a pair of side plates 3.
Therefore, the shaft 4 is attached to the button 5 on the side plate 3.
The shaft 4 is rotatably supported via a shaft 4, and a webbing 6 is wound around the shaft 4. One end of the shaft 4 projects from the side plate 3 to form a protrusion 7, and a slit 8 is formed in the protrusion 7. An external gear 9 is attached to the tip of the protruding portion 7 of the shaft 4 so as to rotate together with the shaft 4, and has external teeth 10 carved on its outer periphery.

Reference numeral 11 denotes a disk-shaped rotating member that is rotatably supported by the external gear 9. A sleeve 12 is protruded from the center of the rotating member, and there is a space between the sleeve 12 and the casing 13. , a spiral spring 14 for winding the webbing 6 is attached. Further, a pin 15 is provided protruding from the side surface of the rotating member 11.

Reference numeral 16 denotes a rotary plate rotatably supported by the external gear 9, and an internal gear 18 having internal teeth 17 carved inside is provided on the outer periphery of the rotating plate to project laterally. ing. Furthermore, ratchet teeth 19 are formed on the outer periphery of the rotating plate 16. Further, an annular rib 20 is provided protruding from the side surface of the rotating plate 16.

Reference numeral 21 denotes a planetary gear, which is rotatably supported by the pin 15 of the rotating member 11, and is supported by the external teeth 10 of the external gear 9 and the internal teeth 17 of the rotating plate 16.
It meshes with the

22 is a spiral spring, and the shaft 4
and the annular rib 20 of the rotary plate 16, and is attached to the rotary plate 16 so as to apply a rotational force to the shaft 4 in the webbing winding direction. There is. Therefore, the elasticity of the spiral spring 22 is sufficiently weaker than the elasticity of the spiral spring 14.

Reference numeral 23 denotes a rotating member that is rotatably supported with respect to the main body 1, and a ratchet 24 that can engage and disengage from the ratchet teeth 19 of the rotating plate 16 is provided at the tip of the rotating member 23. , is rotatably attached to the rotating member 23. The rotating member 23 is moved by the spring 25 to the ratchet 24.
is biased away from the ratchet teeth 19, and the ratchet 24 is biased by a spring 26 with respect to the pivot member 23 into engagement with the ratchet teeth 19.

Further, a suction plate 28 is provided on the tail portion 27 of the rotating member 23, and the suction plate 28 is opposed to an electromagnet 29 that is operated from the outside. The switch for the electromagnet 29 is usually incorporated into the seat belt buckle (not shown).
Electricity is applied when the buckle is engaged.

On the other hand, due to the elasticity of the spiral spring 14, a rotational force is applied to the rotating member 11 in a counterclockwise direction (in the webbing winding direction), and as a result, the planetary gear 2
A counterclockwise rotational force is also applied to the rotary plate 16 via the rotary plate 16, and this rotational force causes the weak spiral spring 22 to be fully wound. Therefore, the rotational force applied to the rotating plate 16 is
The rotating force of the shaft 4 is generated through the tightly wound spiral spring 22, and the webbing 6 is fully wound around the shaft 4.

When the webbing 6 is pulled out to fasten the seat belt, the shaft 4 rotates clockwise.
Along with this, the external gear 9, the rotating member 11, and the rotating plate 16 also rotate clockwise together with the shaft 4.

When the buckle is engaged after pulling out the webbing 6, the electromagnet 29 is energized to attract the suction plate 28,
The pivot member 23 is pivoted clockwise and the ratchet 24 engages the ratchet teeth 19. When the extra webbing 6 is wound up, the elasticity of the spiral spring 14 causes the rotating member 11, external gear 9,
The rotating plate 16 rotates counterclockwise, but since the rotating plate 16 is stopped by the ratchet 24, the rotational force of the spiral spring 14 is attenuated and transmitted to the shaft 4 by the action of the planetary gear 21. The winding force applied to the webbing 6 is reduced, and the feeling of pressure on the wearer's body is reduced.

By the way, in this type of device, since the ratchet 24 needs to engage and disengage from the ratchet teeth 19 of the rotary plate 16, the tip of the rotary member 23 rotates approximately in the radial direction of the rotary plate 16. There is a need. For this purpose, it is necessary that the fulcrum 30 and the tip of the rotating member 23 be located substantially in the tangential direction of the rotary plate 16. Therefore, conventionally, the rotating member 23
is approximately L-shaped as shown in FIG. 2, and the suction plate 28
and the ratchet 24 were provided on opposite sides. Therefore, the shape of the rotating member 23 had to be large, and the space within the retractor also needed to be large.

Further, as described above, since the tip of the rotating member 23 moves in the substantially radial direction of the rotary plate 16, the direction of movement of the ratchet 24 also becomes the same direction. Therefore, in order to release the operation of the pressure relief mechanism, the rotating member 2
3 attempts to rotate counterclockwise in FIG. 2, the tip of the ratchet 24 does not come off from the ratchet tooth 19 because a counterclockwise rotational force is acting on the rotary plate 16, and the pressure relief mechanism It may not be possible to release the .

The present invention has been developed in consideration of such circumstances, and by making the direction of movement of the tip of the rotating member 23 substantially parallel to the tangential direction of the rotating plate 16,
The rotating member 23 is made smaller, the shape of the entire retractor is made compact, and the ratch 2 is made smaller by the movement of the tip of the rotating member 23.
4 is converted into a radial movement of the rotary plate 16 by a cam, thereby enabling the ratchet 24 to engage and disengage from the ratchet teeth 19.

FIG. 3 shows the main part of the present invention. In this example, the electromagnet 29 is oriented in the opposite direction to that in the prior art example, and the rotating member 23 extends in a substantially straight line from the tip of the electromagnet 29 in a substantially upward direction. The rotating member 23 has a fulcrum 30 at its center, and the direction of movement of the tip of the rotating member 23 when the electromagnet 29 is activated is substantially tangential to the rotating plate 16. They are becoming parallel. A ratchet 24 is provided at the tip of the rotating member 23.
is rotatably supported and biased by a spring 31 in the direction of engagement with the ratchet teeth 19.

A cam 32 is fixedly supported on the side surface of the side plate 3 of the main body 1, and a projection 33 protruding from the back surface of the ratchet 24 slides along the cam surface 34.

When the electromagnet 29 is energized, the rotating member 23 rotates counterclockwise as shown by the solid line in FIG. 3, the ratchet 24 is pushed upward to the left, and the protrusion 33 is The cam 32 is moving to the lower side. And the ratchet 24 is the spring 3
1 causes the rotating member 23 to rotate clockwise and engage with the ratchet teeth 19. On the other hand, when the electromagnet becomes de-energized,
The rotating member 23 is rotated clockwise as shown by the chain line. Therefore, the ratchet 24 is pulled toward the lower right in the figure, and the protrusion 33 is biased toward the higher side of the cam 32, and is separated from the ratchet tooth 19 against the elasticity of the spring 31.

According to the present invention, there is no need to extend the rotating member 23 from left to right in the figure, and since the rotating member 23 is linear, the rotating member 23 can be small, and the installation space within the retractor is also small. I'll try it. Therefore, the entire retractor can be made small and compact.

Further, the moving direction of the ratchet 24 when releasing the pressure relief mechanism is the tangential direction of the rotary plate 16 and the direction away from the ratchet teeth 19.
In the process of movement, it rides on the cam 32 and separates from the ratchet teeth 19, so there is no possibility that it cannot separate from the ratchet teeth 19 as in the conventional example, and it can always operate reliably.

[Brief explanation of the drawing]

FIGS. 1 and 2 show an example of a conventional retractor, with FIG. 1 being a central vertical sectional view of the main part, and FIG. 2 being a sectional view taken from FIG. 1.
FIG. 3 is a drawing similar to FIG. 2, showing the main parts of the present invention. DESCRIPTION OF SYMBOLS 1... Main body, 16... Rotating plate, 19... Ratchet teeth, 23... Rotating member, 24... Ratchet, 32... Cam.

Claims (1)

[Scope of utility model registration request] In a pressure relief device for a seat belt retractor, ratchet teeth 19 are provided on the outer periphery of a rotary plate 16.
A rotary member 23 is provided outside the ratchet teeth 19 so that the tip thereof moves substantially parallel to the tangent to the rotary plate 16, and a ratchet 24 is provided at the tip of the rotary member 23. The ratchet 24 is rotatably supported, and the ratchet 24 is urged in a direction to engage the ratchet teeth 19, and as the tip of the rotary member 23 moves on the retractor main body 1, the ratchet 24 is rotated. A ratchet structure in a pressure relief device for a seatbelt retractor, characterized in that a cam 32 is provided to guide teeth 19 into engagement and disengagement.