JPS6048368B2 - Seat belt retractor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a seat belt retractor for automatically retracting a seat belt, and more particularly to a mechanism for controlling the retracting force.

A spiral spring in a winding device such as a conventional glue tractor has its center end fixed to the winding shaft of the winding device, and its outer peripheral end fixed to the main body of the winding device through a storage box such as a barrel.
Generally, by unwinding the seat belt from a winding device, the mainspring spring is further tightened and the winding force of the seat belt is applied.

With conventional winding devices like this, the mainspring spring is tightened when the seat belt is unwound, so the retracting force usually increases as the seat belt is unrolled. Belt systems that are pulled out and worn have the disadvantage that the winding force is too strong when the belt is worn, increasing the feeling of restraint on the occupant and making it uncomfortable to wear the belt.

In particular, when a lap belt or shoulder belt is a continuous webbing and a winding device is installed on the shoulder belt side, the amount of belt winding by the winding device increases further. Therefore, if the strength of the mainspring spring is set to be appropriate when the occupant is restrained, the winding force of the belt during storage will be insufficient. On the other hand, if the belt winding force at the time of storage is set sufficiently, the restraint force at the time of restraining the occupant becomes too strong, resulting in extremely poor usability. In order to eliminate the above-mentioned drawbacks, the present invention aims to provide a seat belt retractor that improves the feeling of wearing the seat belt and improves the retracting performance by controlling the seat belt tension according to the vehicle speed. There is a purpose.

An embodiment of the present invention apparatus shown in the drawings will be described below. In Figures 1 to 3, a frame 1 constitutes the main body of this winding device, and is made of a thick iron plate with a cross section of approximately U.
It is formed by pressing or the like into a letter-shaped shape, and consists of a base and side plates 1a and 1b. This base is provided with a hole 1c so that it can be attached to an appropriate position, for example, on the floor of an automobile, using bolts or the like. Holes for rotatably suspending the take-up reel 2 are provided in the side plates 1a and 1b at mutually opposing positions, and these holes have bearing bushes 1d and 1e made of Teflon or the like.
are installed respectively. Take-up reel 2 is shaft 2
a) Flanges 2b, 2c and shaft portions 2d, 2e described below
It is rotatably suspended on the frame 1 by a shaft 2a. Further, the shaft 2a is configured to attach one end of the belt 3 so as not to rotate. The belt 3 attached in this manner is wound on the shaft 2a between flanges 2b and 2c at both ends of the shaft 2a. Furthermore, one-way gears (not shown) are provided facing each other on the outer circumferential surfaces of the flanges 2b, 2c, and in an emergency, this one-way gear engages with an unillustrated torque device to tighten the take-up reel 2. It is configured to stop the rotation and prevent the belt 3 from unwinding. The belt 3 is a well-known type made of webbing, and one end is wound around the take-up reel 2 as described above, and an anchor or buckle (not shown) is attached to the other end. The spring case 4 and gear case 8 are made of resin or the like and are formed into a substantially cup shape, with a latch attached to a part. It has an opening for engaging a gear and is fixed to the side plates 1b and 1a of the frame 1. The hole 4a in the center is a bearing portion that rotatably suspends a latch gear 5 that constitutes a connection state control mechanism to be described later. In this way, the spring case 4 houses the first spring member 6, and the gear case 8 houses the latch gear 9.

The latch gear 5 (Fig. 3) has a stepped disc shape and is installed inside the spring case 4, with shaft portions 5c (Fig. 1) at both ends,
Bearing part 5e Bearing part 4a of spring case 4) Spool 2
It is rotatably suspended by the shaft portion 2d. The large diameter part of this latch gear 5 (right side in Figure 1)
A one-way gear 5a is formed on the outer periphery of the spring, and a spring winding fixing portion is provided in the small diameter portion (left side in FIG. 1). Further, the latch gear 9 is disk-shaped, is installed in the gear case 8, is fixed to the shaft portion 2e of the spool 2, and is integrated with the spool 2. And this latch gear 9
A one-way gear 9a is formed on the outer periphery of. Next, the first spring member 6, which becomes the first spring portion, is a known S-shaped or spiral-shaped spring member, and is housed in the spring case 4, and its outer peripheral end is
The center end of the spring case 4 is connected to the shaft portion 5b of the latch gear 5.
are fixed respectively. The second spring member 7, which serves as the second spring portion, is also of a known type having a spiral shape, and the strength of the spring is set to be weaker than that of the first spring member 6, and is stored inside the large diameter portion of the latch gear 5. The outer peripheral end 7b (FIG. 3) is inserted into and fixed to the spring fixing portion 5e of the latch gear 5, and the central end 7a is inserted into the slit 2e of the shaft 2a as shown in FIG. In this way, the first and second spring members 6,
7 are connected in series with the latch gear 5 as a connection part, and when the latch gears 5 and 9 can rotate (rotate), that is, when both the spring members 6 and 7 are connected, the resultant force of both spring members is applied to the shaft 2a. It is applied and acts as a belt winding force.
Further, when the latch gear 9 is fixed, the shaft 2 is fixed in the winding direction, eliminating the belt winding force. Next, in FIGS. 2 and 3, 10 and 14 are ratchets 1
The plunger 10 is fixed on the base plate of the frame 1 with a known electric solenoid for operating the plunger 10.
Consisting of a, 14a) drive pins 10b, 14b) return springs 10c, 14c, and coils 10d, 14d. Actuators 11 and 15 are actuated by solenoids 10 and 14, and actuators 1f and 1g of the rotating shaft portions of the frame 1
Bearing portions 11A and 15a are rotatably suspended on.

One end of the actuators 11, 15 (lower end in FIGS. 2 and 3) is configured with a U-shaped connecting portion 11d, 15d to be connected to the solenoids 10, 14. It is slidably connected between the drive pins 10b, 14b and the return springs 10c, 14c. Further, at the other end, there are rotating shafts 11B, 15b of ratchets 12, 16, which will be described later, and a stopper 11C.
, l5c are formed, and the ratchets 12, 16 are suspended rotatably within a set range. 12 and 16 are ratchets rotatably suspended on the rotation shafts 11B and 15b of the actuators 11 and 15, and rotary bearings 12a and 1
6a) and one-way gear 5a of the latch gears 5, 9,
It is composed of tooth tips 12b and 16b that selectively mesh with tooth 9a.

Furthermore, the L ratchet 12 is connected to the actuators 11 and 15.
, 16 are provided with urging springs 13, 17 so as to always urge them to rotate clockwise. Therefore, the ratchets 12, 16 are attached to the stoppers 11 of the actuators 11, 15.
It is stopped in a state where it is in contact with C and l5c (Figs. 2 and 3). As shown in FIG. The plunger 10a moves to the right, and the plunger 10a moves to the left in FIG. Prevents clockwise rotation. In addition, the ratchet 12 is aligned as shown in FIG.
It meshes with the one-way gear 5a and prevents the latch gear 5 from rotating in the counterclockwise direction. Further, when the solenoids 10 and 14 are in a non-energized and non-energized state, the tips of the teeth of the ratchets 12 and 16, 12b and 16b, are connected to the one-way gear 5, as shown by the two-dot chain line in FIGS.
a, 9a, and the latch gears 5, 9 are free to rotate. Note that this operation is performed by the return springs 10c and 14c.
It depends on the urging force of In addition, the actuator 11
rotates counterclockwise, and the tooth tip 12b of the ratchet 12 separates from the one-way gear 5a. Next, based on FIG. 4, the control circuit for the solenoids 10 and 14 will be explained.
d is the coil of solenoid 10, 14d is solenoid 14
The coil 18 is a sequence control device (not shown) that controls a solenoid based on a signal from a vehicle speed detection means 18a that detects vehicle speed, leaning toward the back of the seat, and insertion and release of a buckle. The solenoid coil 14d is inserted into the buckle and the solenoid coil 14d is turned 0N and the coil 10d is turned 0FF when the vehicle speed is 0 or low and the passenger is in the normal driving position leaning against the seatback. Regardless of the normal driving posture, the solenoid coil 14d turns 0FF.
0d becomes 0N.

At high speed, both solenoid coils 14d and 10d are 0.
Becomes FF. Further, when a metal fitting such as a tank is unlocked or released from a buckle, both solenoid coils 10d and 14d are set to 0FF. 19 is a known ignition switch for an automobile, and 20 is a power source for the automobile such as a battery.

Next, to explain the behavior of this embodiment, first, the belt 3
is wound onto the take-up reel 2 and stored in the take-up device, the metal fittings such as the tongue are separated from the buckle, so the switch of the buckle (not shown) is set to 0F.
F, and the solenoid 10d is activated by the operation of the control device 18.
, 14d are de-energized, the ratchet 16 is in the state shown in FIG. 2, and the ratchet 12 is in the state shown in FIG. The tension of member 6 is applied.

In this state, the second spring member 7 is almost fully compressed by the first spring member 6. Next, from this state, when the occupant pulls out the belt 3 to put on the seat belt, the belt 3 is pulled out while tightening the first spring member 6.

If the ignition switch 19 is already turned 0N when the passenger pulls it out and inserts a metal fitting such as a tongue into the buckle and locks it, and the passenger is in the normal driving position, the buckle switch (not shown) will be turned 0N, and the passenger will be in the normal driving position (not shown). The seat back switch to be detected is also turned ON, and the coil 14d of the solenoid 14 is brought into an energized and excited state by the operation of the sequence control device 18. Further, the coil 10d of the solenoid 10 is de-energized, and the ratchet 16 is brought into mesh with the one-way gear 9a of the latch gear 9, as shown by the solid line in FIG. Since the suction force of the solenoid 14 is set to be sufficient to inhibit the rotation of the latch gear 9, in this state, the rotation of the latch gear 5 in five clockwise directions is completely inhibited. On the other hand, regarding the counterclockwise rotation of the latch gear 9, since the latch 16 can rotate on the actuator 15 even when the solenoid 14 is in the suction state, the biasing spring 17 is activated as shown by the two-dot chain line in FIG. Against,
Since the latch 16 rotates clockwise, it is rotatable. That is, even after the metal fittings such as the tongue are inserted into the buckle and locked, if the belt 3 is pulled out due to the occupant's behavior,
The latch gear 9 can also freely rotate clockwise.

In this way, when the seat belt is attached to the passenger,
Latch gear 9 rotates counterclockwise (belt 3 pulling direction)
is free and rotation is inhibited only in the clockwise direction (the winding direction of the belt 3), so the tension of the first and second spring members 6 and 7 is no longer applied to the take-up reel 2, and when the belt is attached, the vehicle speed is 0. Or, if the vehicle is at low speed and in a normal driving position, the belt tension will disappear. Next, when the vehicle speed becomes medium speed, a signal from the vehicle speed detection means 18a is input to the control device 18, and the coil 14d of the solenoid 14 is de-energized and de-energized by the operation of the control device 18, regardless of whether the seatback switch is 0N or 0FF. Therefore, the coil 10d of the solenoid 10 becomes energized and excited.

In FIG. 2, the rotation of the latch gear 9 becomes free because the ratchet 16 moves to 16'. In addition, in FIG. 3, since the latch 12 meshes with the latch gear 5, the tension of the first spring member 6 is no longer applied to the take-up reel 2, and only the tension of the second spring member 7 is applied. Tension will be reduced. Next, when the vehicle speed becomes high, the solenoid coils 10d and 14d are deenergized and de-energized by the sequence control device 18, and the ratchets 12 and 16 are turned 12', 12' and 14d, respectively, as shown by two-dot chain lines in FIGS. Since the latch gear 5 is moved to the position 16' by the rotational force of the return springs 10c, 14c and the latch gears 5, 9, the counterclockwise rotation of the latch gear 5 becomes free, and the first spring member 6, which had been retightened, is removed all at once. is released, and the second spring member 7 is tightened. While eating,
It stops at a position where the tensions of both spring members 6 and 7 are balanced.

In this state, when the belt tension is high, the second spring member 7 is almost fully compressed, and the strong tension of the first spring member 6 applies a strong tension to the belt. Next, when the belt is retracted, when a metal fitting such as a tongue is unlocked from a buckle by an occupant, the sequence control device 1
8 receives a signal from a buckle switch (not shown),
And the seatback switch signal is on and the vehicle speed is o.
Or the state in case of q low speed, i.e., solenoid coil 1
0d is a non-energized de-energized state and the solenoid coil 14d is energized and energized, but by the operation of the control device 18, the current is cut off to both solenoid coils 10d and 14d, and both latch gears 5 and 9 are free to rotate. Thus, the state is similar to the state where the vehicle speed is high, that is, the state where the belt winding force is strong, and the belt 3 is taken up on the take-up reel 2.

Therefore, storage defects are less likely to occur. Next, latch gear 5,
If we explain the case where the control mechanism is operated when the position of the latch gear 9 is slightly shifted from that in FIGS. Solenoid 10 hits the tip of tooth 9a.
, 14 may not be fully absorbed, but in this case,
Since the tension of belt 3 is not reduced, latch gear 5,
9 rotates as the belt 3 is pulled out, and the latch gear 5
, When the damage prevention of 9 is gone, Ratchet 12, 16
Since the solenoids 10 and 14 are completely in the suction state at the same time as they are completely at the inhibiting position, the state shown by the solid line in FIGS. 2 and 3 can be immediately achieved.

Also, solenoid 1? , 14 reaches several times the initial suction force in the complete suction state, so the ratchet 1
2 and 16 are in mesh with the latch gears 5 and 9, the rotational force is greater than that of the latch gears 5 and 9 and can be sufficiently suppressed. Further, since the solenoid is designed to be able to lock the latch gear in a fully suction state, the initial suction force of the solenoid can be reduced, and there is an advantage that the solenoid can be made smaller and cost can be reduced. In the above embodiment, the signal to the sequence control device is sent by a combination of the seatbelt buckle switch and the seatback switch, but either one of the switches may be used in common, or the seat cushion switch, It may also be used in combination with a door switch, handbrake switch, etc.

Further, the first spring part and the second spring part are connected in series in the above embodiment, but one end of the first spring part is connected to the take-up reel, the other end is connected to the main body of the winding device, and the second spring part is connected to the take-up reel. Of course, it is also possible to use a spring means which connects one end to the winding device main body and the other end to a latch gear, and connects and disconnects the latch gear and the winding reel to change the seat belt winding force.

Also, reducing the number of solenoids in FIG. 1 to one, that is,
Using only the solenoid 10, a two-stage belt winding force system is set in which the belt winding force is set to high when the vehicle speed is 0 and the vehicle speed is high, and to a low belt winding force when the vehicle speed is low or medium. It is also possible to In this case, a sequence control device may be used, but it is also possible to eliminate the sequence control device by controlling the solenoid using a known signal that detects the vehicle speed and locks the door. In addition, in the above embodiment, two springs, the first and second spring parts, were used, but it is possible to use only one spring for the first spring part and fix or release this spring using a ratchet and a latch gear. Accordingly, the belt winding force is changed to two stages: a case where the belt winding force is 0 and a case where the belt winding force is large. That is,
The vehicle speed may be detected, and the belt winding force may be o when the vehicle speed is low, and a large belt winding force may be applied when the vehicle speed is 0 or medium to high speed. As described above, in the present invention, since a strong spring means can be used, the belt retracting operation can be stabilized, and the belt winding force can be changed according to the vehicle speed, so it can be used in urban areas etc. The winding force of the belt is set to such a level that the occupant does not feel it, and the belt winding force is increased on highways, etc., giving the occupant stability and peace of mind, and improving the range of use of the belt.

Furthermore, as the vehicle speed increases, the belt winding force increases and the play in the belt decreases, which has the excellent effect of increasing the occupant protection effect in the event of a vehicle collision while increasing the range of use of the belt.

[Brief explanation of the drawing]

FIGS. 1 to 3 schematically show the operating state of an embodiment of the seat belt retractor according to the present invention.
The figure is a partial sectional view seen from the front. FIG. 2 is a partial sectional view seen from the right side, and FIG. 3 is a partial sectional view viewed from the left side. FIG. 4 is an electric circuit diagram for explaining the operation of a solenoid constituting the control mechanism of the device. 2... Winding shaft, 3... Seat belt, 6, 7... Spring means, 5, 9, 12
, 16, 10, 14, 18...Latch gears 5, 9 and ratchets 12, 16, respectively, which serve as a connection state control mechanism.
, solenoids 10, 14, sequence control device 18, 1
8a...Vehicle speed detection means.

Claims (1)

[Claims] 1. A winding shaft to which one end of the seat belt is connected and rotatably supported on the winding device body, a spring means for applying a seat belt winding force to the winding shaft via a connection state control mechanism, and a vehicle vehicle speed detection means for detecting the speed of the vehicle, and the connection state control means switches to transmit or cut off the seat belt winding force of the spring means to the winding shaft according to a vehicle speed signal from the vehicle speed detection means. A seat belt retractor characterized in that it is controlled.