JPH0436895B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a U-shaped frame having two side walls, a belt winding shaft that is supported by both side walls of the U-shaped frame and winds a seat belt, and one end of the shaft. A belt winding return spring provided between the frames, a ratchet wheel fixed to the shaft, a main pawl having a pawl that can be engaged with the teeth of the ratchet wheel, and a belt winding return spring provided between the frames. This invention relates to a small-sized emergency lock-type seatbelt retractor comprising an inertia wheel that is driven according to rewinding acceleration.

In the case of conventional emergency lock-type seatbelt retractors, the main pawl extends parallel to the take-up shaft between both side walls of the U-shaped frame, and both ends of the main pawl swing into fan-shaped holes formed in the side walls. freely supported. This main pawl is disposed at a position radially outward from the belt winding diameter when the seat belt is completely wound so as not to interfere with the winding of the seat belt. Moreover, the two ratchet wheels provided inside the side walls have a relatively large diameter corresponding to the radial position of the main pawl. Thus, because the main pawl is relatively radially outwardly located and the ratchet wheel has a relatively large diameter, the main pawl and the ratchet wheel increase the radial dimensions of the retractor.

Furthermore, if this retractor is equipped with a main pawl operating mechanism that is sensitive to the vehicle body, the overall dimensions of the retractor will increase, and the mounting direction of the retractor in this case must also be considered. There were various drawbacks, such as the need to provide a large installation space for the retractor.

Therefore, it is an object of the present invention to particularly reduce the size of an emergency lock-type seatbelt retractor, that is, to make the seatbelt retractor large enough to correspond to the belt winding diameter when the seatbelt is wound around the retractor. The goal is to be configurable. This problem consists of a U-shaped frame having two side walls, a belt winding shaft that is supported by both side walls of the U-shaped frame and winds up a seat belt, and a belt winding shaft that winds a seat belt between one end of the shaft and the U-shaped frame. A return spring for belt winding provided in between, a ratchet wheel fixed to the other end of the shaft, and a pawl hanging surrounding the outer periphery of the ratchet wheel and fixed to the side wall of the U-shaped frame. a pawl portion that is movable in the tangential direction of the ratchet wheel along a guide surface formed on the pawl housing and that is engageable with the ratchet teeth of the ratchet wheel; a main pawl having a protrusion; a clutch wheel loosely fitted to the shaft and having a substantially radial elongated hole that engages with the protrusion of the main pawl; and ring-shaped internal teeth; , a cam wheel having a cam, an inertia wheel loosely fitted to the shaft, and a hook that is pivotally supported by the inertia wheel and can be engaged with the internal teeth of the clutch wheel by contact with the cam of the cam wheel. This is solved by having the following.

In particular, by surrounding the ratchet wheel fixed to the belt winding shaft with the pawl housing fixed to one side wall, the main pawl itself can be made smaller. When the unwinding rotation of the winding shaft is locked, the load applied to the main pawl can be supported by the entire pawl housing while guiding the main pawl in the tangential direction, and the thickness of the ratchet wheel and the thickness of the main pawl can be appropriately selected. This can prevent these plastic deformations. In addition, a belt-sensing main pawl operation mechanism that engages the main pawl with the teeth of the ratchet wheel in an emergency includes a clutch wheel that operates the axial protrusion of the main pawl, a cam wheel that operates the clutch wheel, and a hook. By sequentially loosely fitting, fixing, and loosely fitting the inertia wheel that bears the slatch wheel to the belt winding shaft, it is possible to fit the operating functional parts of the slatch wheel almost within the outer diameter of the main pawl housing. The emergency locking seat belt retractor of the present invention has the advantage that it can be miniaturized and can therefore be put to practical use in places where installation locations are narrow, such as rear seats. Furthermore, since the emergency locking seat belt retractor according to the present invention responds to the unwinding acceleration of the belt, it will lock in an emergency regardless of the position in which it is worn. Another advantage is that it is ideal as a time-lock seat belt retractor.

Next, the present invention will be explained in detail with reference to illustrated embodiments.

As shown in FIGS. 1 and 2, the emergency locking seat belt retractor equipped with a main pawl engagement device according to the present invention consists of a U-shaped frame 1 having two side walls 2 and 3, A belt winding shaft 4 with a belt insertion groove 4' is supported in holes provided in the side walls 2, 3 on the one hand by a bush 6 and on the other hand by a retainer 10, in which the shaft 4 is provided with an insertion groove 4'. A belt take-up reel 5 is provided outside the shaft 4 in this area. This reel 5 is fixed to the shaft 5 with a screw 14. Button 6 in the hole in side wall 3
One end of the return spring 9 is engaged with the shaft end 14', which is supported by the shaft end 14', and the other end is latched to an engaging portion provided on the inner periphery of the spring case 7. This spring case 7 has a side wall 3
Since the belt is provided with a protrusion 7' projecting axially inward and engaging with a small hole provided in the reel 5, it is possible to unwind and take up the belt wound on the reel 5. The outside of the spring case 7 is covered with a cap-shaped spring cover 18.

A ratchet wheel 12 fixed to the shaft 4 is provided at the end of the shaft 4, which is supported by a boss portion of the retainer 10 in a hole in the side wall 2 of the frame 1 (see FIGS. 1 and 3). The ratchet wheel 12 and the shaft 4 can be integrally formed by forging. As shown in FIG. 3, the ratchet wheel 12 has ratchet teeth 1 on its outer periphery.
3' is provided. A ring-shaped pawl housing 15 surrounding the ratchet teeth 13' is fixed to the side wall 2 of the frame 1 with a retainer 10 in between by screws on the outside of the ratchet teeth 13' in the radial direction. The pawl housing 15 has at least one notch 16 on its inner circumferential surface, and this notch 16 has a guide surface 16'' parallel to a line tangent to the outer circumference of the ratchet wheel 12. The guide surface 16'' is a surface that guides the main pawl 18 accommodated within the notch 16.

The thickness of the main pawl 18 accommodated in the notch 16 of the pawl housing 15 is approximately the same as the thickness of the main pawl housing 15 to the ratchet wheel 12. The main pawl 18 has, on the one hand, a pawl portion 20 that is approximately the same shape as the tooth groove of the ratchet tooth 13', and on the other hand, the pawl portion 18 has a pawl portion 20 that is approximately the same shape as the tooth groove of the ratchet tooth 13'.
It has a guide surface 18'' on which it is guided. The main pawl 18 also has a small protrusion 18' that protrudes outward in the axial direction, and the small protrusion 18' is formed into a long hole extending in the radial direction provided in the disk portion 25' of the clutch wheel 25, which will be described later. 30 is engaged.
By doing this, the clutch wheel 25
When the main pawl 18 is moved in the direction of the arrow C shown in FIG.
The pawl portion 20 of No. 8 is moved to a position where it engages with the ratchet tooth 13'.

The clutch wheel 25 is the clutch wheel 2
The neck 1 of the belt winding shaft 4 is located on the axially outer side of the belt winding shaft 5.
A clutch spring 31 is loosely fitted into a boss portion 21' of a cam wheel 21 (described later) fixed to a clutch wheel 25, and a clutch spring 31 is provided on the outer periphery of a ring portion 26 of a clutch wheel 25. 12 ratchet teeth 13', that is, in the opposite direction of arrow C in FIG. 4. In this case, one end of the clutch spring 31 is connected to the clutch disk portion 2.
5', and the other end is hooked to a hole 19 provided in a pawl housing 15 fixed to the frame 1.

The clutch wheel 25 shown in FIG. 4 has a ring portion 26 fixed to a disk portion 25', and the ring portion 26 is provided with internal teeth 26' on its inner peripheral surface. An engagement surface 26'' of an internal tooth 26' of a ring section 26 of a clutch wheel 25 that can be engaged with a claw section 37' of a hook 37 pivotally supported on a flywheel 32, which will be described later, extends in a radial direction from the rotation center of the clutch wheel 25. It almost coincides with the line of internal tooth 26'.
Information surface 26

Claims (1)

[Scope of Claims] 1. A U-shaped frame 1 having two side walls 2 and 3, and a belt winding shaft 4 bearing on both side walls 2 and 3 of the U-shaped frame and winding a seat belt B. , a belt winding return spring 9 provided between one end of the shaft and the U-shaped frame 1, a ratchet wheel 12 fixed to the other end of the shaft 4, and an outer periphery of the ratchet wheel. A pawl housing 15 surrounding and fixed to the side wall 2 of the U-shaped frame, and a guide surface 1 formed on the pawl housing.
6'' along the tangential direction of the ratchet wheel, and the ratchet wheel 12
a pawl portion 20 that can engage with the ratchet teeth 13';
The main pawl 18 has a protrusion 18' projecting outward in the axial direction, a substantially radial elongated hole 30 that engages with the protrusion 18' of the main pawl, and a ring-shaped internal tooth 26'. a clutch wheel 25 loosely fitted to the shaft; a cam wheel 21 fixed to the shaft and having a cam 22; and an inertia wheel 32 loosely fitted to the shaft.
The clutch wheel 2 is pivotally supported by this inertia wheel, and the cam 22 of the cam wheel comes into contact with the clutch wheel 2.
An emergency locking type seat belt retractor comprising a hook 37 that can be engaged with the inner teeth 26' of the seat belt 5. 2. The emergency locking type seat belt handle according to claim 1, wherein the guide surface 16'' of the pawl housing 15 that guides the main pawl 18 is formed in the notch 16 of the pawl housing. Tractor. 3 Main pawl 18 is ratchet wheel 12
Claim 1 or 2, characterized in that two pieces are provided facing each other on the outer periphery of the invention.
Emergency locking seat belt retractor as described in Section 1.