JPS5839735Y2 - safety belt retractor - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a safety belt retractor.

Traditionally used in safety belts for vehicles, etc., to prevent vehicle collisions, rollovers, etc.
In an emergency lock type retractor that prevents the safety belt from being pulled out in the event of an emergency such as a sudden stop, a retractor that utilizes rotational inertia, which allows the belt to be rapidly pulled out by the force of an occupant trying to jump out in an emergency, is generally used. However, in such a retracting device, if the pull-out detection performance is increased to a high performance such as 0.3G detection, the inertial mechanism will be There was an inconvenience that the belt would lock when activated, making it impossible to shoot the bow.

In addition, in a winding device that locks the belt by sensing the deceleration of the cutting edge caused by a vehicle collision, etc., if a sensing mechanism is installed in the winding device itself, it can detect a wide range of sensing performance, such as 0.3G to 1°OG. When this was done, the volume of the winding device became large, which caused problems in installing the winding device inside the vehicle.

In addition, if such a sensing mechanism is installed in a location other than the winding device, it will require a lot of electrical wiring inside the car and the winding device will have to be operated electrically, which has the disadvantage that the winding device cannot be used depending on the car model. .

Furthermore, in many of the conventional devices described above, locking is performed by engaging a pawl also made of iron to a ratchet wheel made of iron fixed to the belt take-up reel, which reduces the number of parts and weight. Furthermore, there was also the drawback that it placed restrictions on miniaturization and weight reduction of the device.

Therefore, the inventor of the present invention first eliminated the above-mentioned drawbacks in Japanese Patent Application No. 54-47237, and for example, 0.3
This is a so-called dual type system that has both a sensing mechanism that senses 710 speed in the high performance range of G to 0.7G and a sensing mechanism that senses acceleration of 0.7G or more, and locks the belt drawer for each. We have proposed a safety belt retractor that is a safety type, has a simple structure, has a small number of parts, and can be made smaller, lighter, and less expensive.

However, in this type of device, in the first spring interposed between the flange and the latch member and the second spring interposed between the inertia wheel and the cover, the elasticity of the first spring is Since the second spring is set to be weaker than the above, the outward movement of the inertia wheel only acts when the inertia wheel is rapidly pulled out, and normally due to vibrations of the vehicle body when pulling out or attaching a belt. In some cases, the inertia wheel may swing and the belt may become locked at an undesired time.

This invention aims to solve the above problems and completely prevents the inertia wheel from swinging when the belt is pulled out.
It is an object of the present invention to provide a safety belt winding device that can completely prevent the belt from locking at an undesired time.

This invention will be explained with reference to embodiments shown in the drawings.

As shown in FIG. 1, reference numeral 1 denotes a frame having a U-shaped cross section, and is attached to the vehicle floor, seat, etc. by appropriate means.

Through holes la and lb are provided in approximately the center of both side plates IA and IB of this U-shaped frame 1, respectively, and bearing members 2A-22B are provided in these through holes la and Ib.
A shaft 4 with a shaft wheel 3 is rotatably supported through the shaft.

A return spring 7 is attached to the outside of one side plate 1B of the frame 1 via a ring 5 and a spring pad 6.
A spring cover 8 housing the spring cover 8 is fastened with a coupling screw 9 or the like.

End portion 7A of this return spring 7. 7B is fixed between one end 4A of the shaft 4 and a locking portion 8A of the spring cover 8, and this return spring 7
The belt take-up reel 3 and shaft 4 are urged to rotate in the direction of arrow A (clockwise) shown by the solid line in the figure, and the safety belt has one end fitted onto the belt take-up reel 3. It is designed to wind 10 times.

Therefore, when the safety belt 10 is pulled out, the belt take-up reel 3 and shaft 4 are moved to the arrow B indicated by the broken line in the figure.
direction (counterclockwise).

Further, on the outer surface of the other side plate 1A of the U-shaped frame 1, a plurality of (12 in the figure) locking portions 11 are formed at regular intervals on the outer peripheral surface of the through hole 1a. .

This locking portion 11 consists of a substantially fan-shaped groove or hole (a groove is shown in the figure), and one inner side of the valley groove has a taper 11A that slopes downward in a counterclockwise direction as required.
is formed.

The tip of the shaft 4 protrudes outward from the through hole 1a of the other side plate 1A, and at the base end of the protrusion is a disc-shaped flange 12 having a plurality of notches 12A on the circumference. It is fixed.

A plurality of these notches 12A (six in the figure) are provided at positions corresponding to the grooves 11 provided in one side plate.

A disk-shaped cam plate 13 having a diameter approximately equal to the circumference of the notch 12A is fixed to the outside of the flange 12, and a cam plate 13 that protrudes from the side of the flange 12 is attached to the center of the cam plate 13. Fitting hole 13 fixed to protrusion base 4B
A is formed, and a plurality of guide pieces 13 (six in the figure) are provided along the periphery at a position opposite to the flange 12 and not corresponding to the notch 12A.
B is provided.

Although the cam plate 13 is manufactured separately from the flange 12 and is fixed thereto, the present invention is not limited to this, and the flange 12 and the cam plate 13 may be integrally formed.

Further, on the outside of this cam plate 13, a latch spring 14 of a first spring is housed in a guide piece 13B.
A latch member 15 having a substantially disc shape is attached to the shaft 4 via
The notch 12A of the flange 12 is disposed around the periphery of the latch member 15.
The same number of protrusions 15A (for example, six) as the notches 12A are provided, and the distal end 15a of each protrusion 15A is arranged in a clockwise direction. It is formed into an inclined taper.

This latch member 15 is normally urged outward by the latch spring 14, but when pushed by the action of the cam portion of the inertia wheel 16, which will be described later,
Guided by the side surface of the guide piece 13B of the cam plate 13, it thrusts inward, and the tip of the protrusion 15A passes through the notch 12A of the flange 12 and engages the locking part 11 provided on the side plate 1A. It is designed to engage.

In this case, since the locking portion 11 and the protruding portion 15A are each formed with a taper having a relative inclination, a secure engagement is achieved and rotation in the belt winding direction is not inhibited. .

Further, on the plate surface of the latch member 15, a plurality of (six in the figure) first cam portions 15B are provided at regular intervals on the circumference.

This first cam portion 15B is, for example, a substantially fan-shaped hole,
are formed at equal intervals at corresponding positions between the respective protrusions,
The counterclockwise inner surface of each company forms a taper that widens outward.

Here, since the protrusion 15A of the latch member 15 is always engaged with the notch 12A of the flange 12, the latch member 15 rotates together with the shaft 4, which rotates in response to the pulling out and winding operations of the safety belt 10. There is.

An inertia wheel 16 is disposed outside of the latch member 15 and has a fitting hole 16D supported in a loose manner by the projection 4B of the shaft 4 so as to be movable in the thrust direction.

This inertia wheel 16 has a substantially cup-like shape as a whole, and has a plurality (12 teeth in the drawing) of first ratchet teeth 16A on its outer circumferential surface.
It has the same number of second ratchet teeth 16B as A and is arranged radially toward the center, and further has second ratchet teeth 16B on the inner surface that engage with the first cam hole 15B of the latch member 15. 2 cam portion 16C and the guide piece 13B of the cam plate 13
It has an engaging portion 16F that engages with the engaging portion 16F.

This engaging portion 16F is formed with a taper in the direction of belt withdrawal, if necessary.

Here, the same number of second ratut teeth 16B (12 teeth in the figure) are provided at positions corresponding to the locking portions 11 provided on the side plate 1A of the frame 1.

Specifically, as shown in FIG. 3, the second cam portion 16C is a mountain-shaped protrusion arranged to correspond to the first cam hole 15B provided in the latch member 15. , one side portion 16E of each of the protrusions is tapered downward in the opposite direction to the rotational direction (broken line arrow B) of the latch member 15 when the belt is pulled out.

Such an inertia wheel 16 is usually connected to the second
The protrusion 16C, which is a cam part, is fully inserted into the hole 15B, which is a first cam part, of the latch member 15, and is biased by the second spring 17 so that its base is in contact with the plate surface of the latch member 15. .

This second spring 17 is fixed between the inertia wheel 16 and the bush 18.

Therefore, the rotation of this inertia wheel 16 causes the latch member 15 to
0) If the delay is later than that, the latch member 15 will first slide on the taper 16E of the cam projection 16C of the inertia wheel 16 in the fan-shaped hole 15B, and one of them will move along the axial direction. Become.

Note that the latch member 15 is guided by the protrusion 13B of the cam plate 13, and the inward movement of the inertia wheel 16 is restricted by the protrusion 13B.
The biasing force of the first spring 14 biasing the latch member 15 does not need to be stronger than that of the second spring 17 biasing the inertia wheel 16; It can be done.

Therefore, the inertia wheel 16 is directed to the right (outward) as shown in FIG.
(in the direction of arrow C in the figure).

Furthermore, an engaging portion 16F is provided on the inner surface of the inertial wheel 16 to engage the tip of the guide piece 13B provided on one side of the cam plate 13.

This engaging portion 16F has a taper 16f formed on one side in the rotational direction of the inertia wheel 16, and this taper 16f
is configured to easily separate the guide piece 13B of the cam plate 13 from the retaining portion 16F of the memory wheel 16 when the inertia wheel 16 moves toward the cover 19 due to inertia.

A fan-shaped retaining portion 16 (three in the drawing) is formed between the fitting hole 16D of the inertia wheel 16 and the second ratchet tooth 16B, and the protrusion 18A of the bushing 18
are configured to engage with each other.

Reference numeral 19 designates a cup-shaped cover attached to the side plate surface of the frame 1 with fasteners such as screws 21 so as to cover each of the above-mentioned members, and the inner surface corresponds to the second ratchet teeth 16B provided on the inertia wheel 16. The same number of third ratchet teeth 19A (12 teeth in the drawing) are provided at the positions where the third ratchet teeth 19A can mesh with the third ratchet teeth.

This third ratchet tooth 19A meshes with the second ratchet tooth 16B when the inertia wheel 16 moves outward due to the action of the first and second cam portions as described above. It is designed to stop rotation.

Therefore, the second and third ratchet teeth 16B, 19A
When the rotation of the inertial wheel 16 is stopped due to the engagement of the latch member 15, the latch member 15 moves to the left (inward) in the figure (in the direction of the arrow) as shown in FIG.

Here, the number of the third ratchet teeth 19A does not necessarily have to be the same as the number of the second ratchet teeth, and it is sufficient that they are formed at at least one location.

In addition, the fitting hole 1 provided at the lower part of the side plate 1A of the frame 1
An inertial sensing device 20 (hereinafter referred to as a sensor) is housed and held inside.

This sensor 20 includes a box-shaped case 20A in which a dish-shaped protrusion 20C is formed approximately in the center of a bottom plate 20B, and has openings at the top and sides, and is usually placed on the dish of the protrusion 20C. In the operating state, it is swingably attached to the case 20A via a ball 20D which is removably installed on the peripheral side of the plate and a pin 20E, and the distal end claw is moved to the above-mentioned position by the relocation of the ball 20D. inertia wheel 1
It is comprised of an engaging piece 20F that is arranged to move between a position where it engages and a position where it does not engage with the six first ratchet teeth 16A, and a cap 20G that covers the opening of the case 20A.

This sensor 20 detects, for example, 0 when the vehicle suddenly stops or tilts.
．． The relationship between each member is set so that it will act when an acceleration of about 3G to 0.7G is applied, and the relationship between other members, such as the weight of the inertial wheel 16 and the spring 17, will be affected by the impact of a vehicle collision, etc. For example, the value is set so that when an acceleration of 0.7 G or more is rapidly applied, the inertia wheel 16 is pushed outward and collides with the inner surface of the cover 19.

Incidentally, among the above-mentioned members, at least the frame 1. Reel 3. Shaft 4. Although it is preferable to use a material with high strength such as iron for the flange 12° latch member 15 due to its nature, the other members may use lightweight and inexpensive materials such as synthetic resin.

Next, the operation of the above will be explained.

When the safety belt 10 is in a normal state and is pulled out at a normal speed, reel 3. Shaft 4. Flange 12. Cam plate 13. The latch member 15 and the inertia wheel 16 rotate at the same time as the shaft 4. At this time, the latch member 15 is not pushed by the cam protrusion 16C of the inertia wheel 16, so it does not move.
A is never engaged with the locking portion 11 of the side plate 1A of the frame 1.

In this way, the safety belt 10 is stretchably pulled out and retracted in accordance with the movements of the occupant.

Next, as shown in FIG. 4, when the vehicle suddenly stops or tilts, for example, an acceleration force of about 0.3G to 0.7G (over 770, the rolling of the ball 20D of the sensor 20 causes the engaging piece 2
0F moves as a-)b-+c, and the inertia wheel 16
meshes with one of the first ratchet teeth 16A.

At this time, the safety belt 10 is about to be pulled out due to the acceleration force of the occupant, and the shaft 4 and the flange 12 fixed to the shaft 4. Cam plate 13 and latch member 15 will now rotate, but inertia wheel 16 will not.

At this time, due to the interaction between the first cam hole 15B of the latch member 15 and the second cam portion 16c of the inertia wheel 16, the inertia wheel 16 first moves outward toward the second spring 17.
The second ratchet teeth 16B and the third meshing protrusion 19A are pushed outward against the inner surface of the cover 19 (FIG. 5a), so that the second ratchet teeth 16B and the third meshing protrusion 19A engage with each other. Movement is prevented (Fig. 5b).

In this case, since the second and third ratchet teeth are provided at the same spacing and in the same number, their meshing is performed reliably and smoothly.

Then, at the stage when the movement of the inertia wheel 16 in the thrust direction is blocked, the cam part 15B of the latch member 15 is pushed by the cam part 16C of the inertia wheel 16.
4 and is pushed leftward (inward) in the figure while being guided by the guide piece 13B of the cam plate 13.

As a result, the protruding portion 15A of the latch member 15 engages with the locking portion 11 of the frame 1, and the withdrawal of the safety belt 10 is locked (FIG. 5C).

In this case, the protruding portion 15A of the latch member 15 and the locking portion 11 of the frame 1 that receives the protruding portion 15A are provided with corresponding tapers, and the arrangement of each member corresponds to each other, so that the retention thereof is ensured. will be carried out smoothly and reliably.

Next, if the force speed of 0.7 G or more is suddenly reduced due to a collision of the vehicle C or the like, the inertia wheel 16 will lag behind the rotation of the shaft 4.

In this case as well, the cam hole 15 of the latch member 15
B and the cam portion 16C of the inertia wheel 16, the inertia wheel 16 is first moved outward, and the ratchet teeth 16B engage the engagement projections 19A of the cover 19, thereby preventing rotation.

Thereafter, the safety belt 10 is finally locked in the same manner as in the case described above.

In this way, the belt drawer is reliably locked even in the case of incomplete activation of the sensitive sensor.

In any case, if the posture of the vehicle or the occupant returns to its original state, the sensor returns to normal, and the latch member 15 and inertia wheel 16 return to their original positions due to the elastic force of the springs 14 and 17. The belt will be unlocked.

Also, in the above operation, in any case, frame 1
The number of locking parts provided on the side plate 1A and the inertia wheel 1
By making the number of the second ratchet teeth 16B formed on the side surface of the latch member 15 the same and correspondingly arranged, the engagement between the protruding portion 15A of the latch member 15 and the locking portion 11 is performed simultaneously. Therefore, the belt pull-out operation can be quickly and reliably locked.

The action of the cam plate 13 during the above operation will be described in detail.

Except for emergency locking, the tip of the guide piece 13B of the cam plate 13 is engaged with the retaining part 16F of the inertia wheel 16, so the relative position between the flange 12 and the inertia wheel 16 is secured, and therefore the inertia wheel 16 is There is no possibility that the latch member 15 will be erroneously moved due to swinging and thrust movement when unnecessary.

That is, it is possible to reliably prevent malfunctions, and there is no need to provide any difference in strength between the first spring 14 and the second spring 17.

In addition, in the case of emergency locking, the protrusion 15A of the latch member 15 that moves in the thrust direction is guided by the side surface of the guide piece 13B of the cam plate 13, so that the operation becomes smooth and reliable. It will contribute.

Furthermore, since the guide piece 13B of the cam plate 13 and the inertia wheel 16 are in a state of frictional engagement except during emergency locking, even if there is some impact, the flange 12 (or shaft 4) and the inertia wheel 16 are in a state of frictional engagement. There is no rotational deviation between the two, and malfunctions due to various factors can be prevented.

It should be noted that the above embodiment is merely an example, and it goes without saying that each member can be replaced with another member having the same function.

As detailed above, according to the device of this invention, when the occupant fastens the safety belt, the belt will not be locked even if the belt is pulled out quite suddenly, and in an emergency, the vehicle body detection and belt withdrawal detection will be activated. Double safety system allows the belt to be locked safely.

Moreover, since it has an extremely simple configuration and many of the members are made of synthetic resin or the like, it can contribute to miniaturization and weight reduction of the device.

Furthermore, when the belt is being pulled out, the inertial wheel is completely prevented from swinging, and the belt can be completely prevented from locking at an undesired time, which is an excellent effect.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the device of this invention;
Figure 2 is a partially cutaway sectional view showing the assembled state;
The figure is a schematic perspective view showing an example of the configuration of an inertia wheel used in this device, FIG.
6c is a sectional view of a main part for explaining the operation of the device of this invention, and FIG. 6 is a sectional view for explaining the operation of the device of this invention. 1... Frame, 3... Belt take-up reel, 4... Shaft, 10... Safety belt, 11... Locking Part, 12...
Flange, 12A...Notch, 13...
・Cam plate, 14... Spring, 15.
...Latch member, 15A ...Protrusion part, 1
5B...First cam portion, 16...Inertia wheel, 16A...First ratchet tooth, 1
6B...Second ratchet tooth, 16C...
...Second cam part, 17...Spring, 19
...Cover, 19A...Third ratchet tooth, 20...Inertial sensing device, 20D...
···Pole.

Claims (4)

[Scope of utility model registration request] (1) One end of the safety belt is fixed to a belt take-up reel that is fixed to a shaft that is rotatably supported via a bearing member between both side plates of a U-shaped frame, and resists the biasing force of an elastic spring. In the belt winding device, the belt is pulled out and retracted by the biasing force of an elastic spring. and a plurality of notches fixed to the shaft protruding from the side plate and formed at predetermined intervals on the circumference, and not corresponding to the notches in the circumferential part on the opposite side of the frame. A flange having a plurality of guide pieces protruding from the flange, and a flange that constantly meshes with the notch of the flange and runs along the side surface of the guide piece of the flange between a position where it engages with the locking part and a position where it does not engage with the locking part. a latch member that is movably supported by the shaft and has a plurality of first cam parts arranged at predetermined intervals on the circumference, and a latch member that is formed with a movable protrusion and is disposed at predetermined intervals on the circumference; and between the flange and the latch member. a first biasing member that is inserted and biases the latch member to a position where the protruding part of the latch member does not normally engage with the locking part of the side plate; It has an engaging part that engages with the guide piece and a plurality of second cam parts corresponding to the first cam part, and has first ratchet teeth arranged at predetermined intervals on the outer peripheral surface, and further has On the outside there is a second
an inertia wheel that is movably supported on the shaft and has ratchet teeth formed therein; a cover that is fixed to the frame and has third ratchet teeth that can mesh with the second ratchet teeth on its inner surface; a second biasing member inserted between the wheel and the cover and biasing the inertia wheel to a position where the second ratchet teeth of the inertia wheel and the third ratchet teeth of the cover do not normally mesh; an inertial sensing device disposed at the bottom and having an engaging piece capable of engaging with a first ratchet tooth in response to acceleration or deceleration of the vehicle, and a latch member that rotates when the safety belt is rapidly pulled out when the vehicle suddenly decelerates; The cam portion of the latch member is rotated by either a delay in rotation due to the inertia of the inertia wheel itself, or control of the inertia wheel by the engagement piece engaging the first ratchet tooth in response to the inertia sensing device. Pushed by the cam part of the inertia wheel, the protruding part moves along the side of the guide piece, passes through the notch, and engages with the locking part, thereby locking the rotation of the belt take-up reel. A safety belt winding device characterized by: (2) The safety belt winder according to claim 1), wherein the first cam part and the second cam part each have a taper inclined in a direction opposite to the direction in which the belt is pulled out. Device. (3) Registration of a utility model characterized in that the engagement between the protrusion of the latch member and the locking portion is synchronized by making the number of the locking portions and the number of teeth of the second ratchet teeth the same. A safety belt retractor according to claim (1). (4) The inertia sensitive device includes an engagement piece that moves between a position where it engages and a position where it does not engage with the first ratchet tooth of the inertia wheel, and a sphere that rolls when the vehicle is decelerated; A safety belt winding device according to claim (1) of the utility model registration, characterized in that the locking piece is actuated by the transfer of the sphere.