JPS6116152A - emergency rock retractor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a webbing retractor equipped with an emergency locking mechanism for aircraft, automobiles, etc., and more particularly to a webbing sensing retractor.

In general, seat belt retractors include an emergency lock retractor (E L R) that locks the webbing drawer only in an emergency, and an automatic lock retractor (A) that locks the webbing drawer at any position. LR). There are two types of emergency locking mechanisms: a vehicle body sensing type that locks when the vehicle body receives an impact or is tilted significantly, and a webbing sensing type that locks when the webbing is pulled out early.

Vehicle body sensing type ELRs are generally used as seatbelts for front seats, but there are also examples where vehicle body sensing type ELRs are used, which can combine the above ELR and ALR and switch from one to the other by pressing a button. There is. However, in the case of a seat belt for a rear seat, there is a restriction in the installation space and the direction in which the webbing is pulled out is different depending on the type of vehicle. Therefore, when adopting the vehicle body sensing method for rear seats, it is necessary to adjust the sensing angle of the sensing mechanism for each vehicle type. For this reason, a webbing-sensing emergency locking mechanism is usually used for rear seats, which allows the user to freely choose the mounting mode. By the way, when comparing the webbing-sensing ELR and ALR, the ELR, which does not lock the webbing when it is pulled out, is generally better in terms of ease of use when wearing a seatbelt. However, in Europe and America, it is mandatory for children to sit in the rear seat, and therefore ALR is convenient for restraining children so that they do not move around while driving, and for securing child seats.
is suitable for rear seats.

In this case, if the vehicle body sensing type ELR and ALR are combined and switched by button operation as in the case for the front seats,
It is necessary to adjust the sensing mechanism according to the installation method, and a pushbutton is also required, leading to an expensive amplifier, and there is no room for installation space.9 The present invention was made in view of the above points. It is an object of the present invention to provide a webbing-sensing retractor that can be switched to an automatic locking mode when desired without using special switching means and is suitable for use in rear seats.

Hereinafter, the configuration of the present invention will be explained based on specific examples. FIG. 1 is an exploded perspective view showing a webbing sensing retractor as an embodiment of the present invention, and FIGS. 2 and 3 are a plan view and a side view thereof. Webbing W
The reel 1 for winding up the webbing is made up of a pair of latch plates lb, lb fixed to both ends of a cylinder 1a on which the webbing is wound, and a large number of ratchet teeth are evenly formed on the entire circumferential surface of each latch plate 1b. has been done. This rule 1
is extrapolated to the shaft 2 so as to be able to rotate integrally therewith. The shaft 2 on which the reel 1 is inserted is inserted into insertion holes 3b, 3b formed in opposing side plates βa, 3a of a U-shaped retractor base 3, for example, and is rotatably supported. There is.

A mounting hole 3d is drilled in the bottom cutout 3c of the retractor base 3, and this is used to attach the seat belt retractor to an appropriate position on the body of a vehicle such as an automobile using a fixing member such as a bolt. be able to.

A spiral spring 4 is attached to one end of the shaft 2 protruding from the side plate 3a. The spiral spring 4 urges the shaft 2 and the reel 1 to rotate in the direction of winding the webbing W. The spiral spring 4 is covered with a bowl-shaped case 5. Both ends of the spiral spring 4 are locked at appropriate positions on the inner peripheral surfaces of the shaft 2 and the case 5, respectively.

The other end of the shaft 2 is equipped with a mechanism that detects a change in the webbing unwinding speed when it is unwound at a predetermined speed or higher, extracts it as a dynamic way of unwinding, and transmits it to the required part. Detection means are provided. In this example, a flange 6 is fitted to one end of a shaft 2 formed in an oval-shaped cross section so as to be rotatable therewith. Two pins 6a and 6b are erected on the back side of the side of the flange 6 into which the shaft 2 is fitted. A lock piece 7 having a sharp claw portion 7a formed at the tip thereof is rotatably inserted into one pin 6a through a hole 7b drilled approximately in the center, and the tip of this pin 6a is attached to a stopper. The retainer flange 8 is rotatably inserted into one of two holes 8a formed in the retainer flange 8. The other pin 6b has a disc-shaped inertia block 9 formed with a groove 9a and a notch 9b for accommodating the lock piece 7, retainer flange 8, etc.
is rotatably inserted through a bottle hole 9c bored in its center, and the tip of this shaft 6b is rotatably inserted into the other hole 8b similarly bored in the retainer flange 8. . FIG. 4 is a view of the assembled state of the flange 6, lock piece 7, inertia block 8, and retainer flange 9 viewed from the shaft 2 side. In FIG. 4, a coil spring 10 is stretched between a proper position on the claw part 7a side of the lock piece 7 housed in the groove part 9a of the inertia block 9 and a corresponding proper position on the flange 6.

Therefore, when the speed change of unwinding the webbing increases beyond a predetermined value, the inertia block 9 cannot follow the rotation (arrow) of the flange 6 due to its own inertia, causing a rotation delay with respect to the flange 6, as shown in FIG. <] The retainer flange rotates while being in contact with the side portion 9b of the block 9 on the upstream side with respect to the rotational direction of the notch portion 9b. That is, the flange 6 rotates relative to the block 9 around the pin 6b within the range of the notch 9b. Therefore, the lock piece 7 into which the pin 6a is inserted cannot be slid along the groove 9a (see FIG. 4), and the tip claw 7a is attached to the block 9.
protrude from

An assembly consisting of the flange 6, lock piece 7, inertia block 9, and retainer flange 8 is housed in a bowl-shaped latch cup 11 that is rotatably fitted onto the shaft 2. The inner peripheral surface of the side wall of the latch cup 11 is provided with ratchet teeth 11a evenly distributed over the entire circumference. and.

An annular clutch spring 12 is attached to the outer peripheral surface of the side wall so as to be frictionally engaged. Therefore, the tip claw portion 7a of the lock piece 7 protruding from the inertia block 9 is
As shown in FIG. 5, the latch cup 11 and the shaft 2 rotate together as they mesh with the ratchet teeth 11a, and the clutch spring 12 follows and rotates as a result of frictional engagement therewith.

Two engaging protrusions 12a, 12a are erected at appropriate positions on the outer peripheral surface of the clutch spring 12, and these engage with a switch mechanism to be described later to operate the locking member.

In FIG. 1, both side plates 3a and 3 of the retractor base 3 are shown.
Diagonally below the insertion holes 3b and 3b of a.

Sector-shaped holes 3e and 3e are drilled, respectively. Both ends of a pawl pawl 13 that engages with the aforementioned latch plate 1b and locks only the feeding rotation of the reel 1 are inserted into these fan-shaped holes 3e, 3e, respectively. A pair of lock teeth 13a, 13a are protruded from both ends of the ball 13, and these engage with the ratchet teeth of the latch plate 1b, respectively. A sensing plate 18 is fixed between the pair of lock teeth 13a and L3'a, which comes into contact with the webbing wound on the reel 1 and senses the amount of winding. At least both ends of the ball 13 are formed into a plate shape with a rectangular cross section, and therefore, the ball 13 supports both ends in a loosely fitted state that can rotate within the range of the central angle α of the fan-shaped hole 3e. has been done. The end of the ball 13 of this example, which corresponds to the end on which the acceleration detection mechanism of the shaft 2 described above is attached, is formed in two stages, and the lower end 13b protruding from the side plate 3a has a
A switch mechanism is installed to appropriately switch between two types of locking methods: ALR and ELR.

As the switch mechanism of this example, a toggle mechanism is employed in which a lock arm 14 and a swing arm 15 are connected by a spring 16, and the lock arm 14 and the swing arm 15 are connected to each other and operated by a snap action due to the cooperative effect of these elements. In the lock arm 14, an L-shaped engagement angle 14b and a locking angle 14c to which one end of the spring 16 is locked are protrudingly provided at a predetermined local location of the disk 14a, and a locking angle 14c that locks one end of the spring 16 is protruded from a central portion of the disk 14a. A center hole 14d having a rectangular shape substantially the same as the tip cross section of the ball 13 is bored in the center hole 14d.

The tip 13b of the ball 13 is fitted into the center hole 14d, and the ball 13 and lock arm 14 rotate together.

The engagement angle 14b is provided so as to be able to engage with the engagement protrusion 12a when the clutch spring 12 described above rotates. Therefore, the engagement angle 14b engages with the engagement protrusion 12a, and the lock arm 14 is rotated, so that the ball 13 is moved to the side 1 where the lock tooth 13a is not provided.
It rotates as a unit using 3G as a fulcrum. swing arm 15
is approximately fan-shaped, and has a locking protrusion 15a erected at its base to which the other end of the spring 16 is locked, and a fan-shaped hole 15b opening in the same direction is bored slightly closer to its tip. It is set up. The distal end 13b of the ball 13, on which the lock arm 14 is fitted, is loosely inserted into the fan-shaped hole 15b, and a stopper 17 for preventing falling off is fixed to the distal end. A spring 16 is stretched between each locking angle 14b and the locking protrusion 15a of the lock arm 14 and swing arm 15, and its elastic force moves the pole 13 via the lock arm 14 to the locked side or to the unlocked side. Apply force to either side.

Here, the snap operation for switching the locking method of the toggle switch mechanism of this example will be explained based on FIGS. 6a to 6c. Figure 6a shows the ELR state of the switch mechanism in this retractor, and Figure 6c shows the ALR state.
FIG. 6b shows the ELR and ALR in their neutral positions, respectively. When the shaft (not shown) is rotated with a speed change of more than a predetermined value, the above-mentioned detection means is activated, and the clutch spring 12 rotates clockwise following this, causing the engagement protrusion 12a to engage with the lock arm 14. The joint angle 14a is engaged, and the lock arm 14 is engaged with the spring 16.
It is rotated counterclockwise together with the pole 13 about its side portion 13c as a fulcrum against the urging force of the pole 13. In this rotational movement, after passing the neutral position where both ends of the spring 16 and the side 13c of the ball 13 serving as a fulcrum are aligned in a straight line as shown in FIG. 6b, the direction of the biasing force of the spring 16 becomes counterclockwise. After that, it rotates smoothly along the biasing force, and the ALR state shown in FIG. 6C is obtained. Also, at the same time, the swing arm 15 moves to the side part 13c.
The spring 16 is rotated clockwise by the biasing force of the spring 16, and the line connecting both ends of the spring 16 is shifted from the fulcrum O, so that the ALR state is stably maintained. In the ALR state, the lock teeth 13a of the ball 13 mesh with the ratchet teeth provided on the latch plate 1b of the reel 1, and the webbing rotates in the payout direction (clockwise in the figure).
to prevent

When switching from ALR to ELR, first, as shown in FIG. 7, the reel 1 is rotated counterclockwise by the elastic force of the spiral spring 4 to wind the webbing W around the cylinder 1a. In this case, due to the effect of the ratchet engagement, the reel 1 is prevented from rotating only in the unwinding direction of the webbing W, and is smoothly rotated in the winding direction (counterclockwise in the figure). The tip of the sensing plate 18 is brought into contact with the wound webbing W, and as the amount of winding increases, the ball 13 is gradually rotated clockwise around the side portion 13c. That is, in FIG. 6c, as the sensing plate rotates, the lock arm 14 is gradually rotated in the clockwise direction against the biasing force of the spring 16 acting counterclockwise. After reaching the neutral position shown in the figure, the direction of action of the biasing force of the spring 16 changes in the same way, and the sixth
Return to the ELR state shown in figure a. As mentioned above, ELR and A
Since the bipolar states of LR are each maintained along the biasing force of the spring 16, each state is stably maintained.

The operation of the above embodiment configured as described above will be explained below. The retractor of this example always operates in the ELR state when it normally pulls out and winds up the webbing. When the webbing W is suddenly pulled out due to a collision or the like when the belt is attached, and the rotational angular acceleration of the shaft 2 exceeds a predetermined value, the inertia block 9, which is loosely fitted to the shaft 2, will not rotate due to its own inertia. The rotation cannot be followed and a rotation delay occurs with respect to the shaft 2. That is, shirt 1~
2 rotates toward the advancing side relative to the inertia block 9. As a result, the lock piece 7 rotatably supported on the pin 6a of the flange 6 is moved to the inertia block 9.
The latch cup 11 and the shaft 2 are rotated together by protruding from the latch cup 11 and meshing with ratchet teeth 11a provided on the inner circumferential surface of the latch cup 11. When the latch cup 11 rotates, the clutch spring 12 follows and rotates due to frictional engagement. As the clutch spring 12 rotates, its engagement protrusion 12a adjusts to the engagement angle 1 of the lock arm 14.
4a, the toggle switch mechanism operates as described above, and the ball 13 engages with the latch plate 1b, and the EL
The locking method changes from R to ALR state. After this, even if the webbing W is attempted to be pulled out, the resilient force of the spring 16 urges the pawl 13 toward the lock side, so that unwinding is reliably prevented and the occupant is safely protected.

When storing the webbing W after releasing the belt, since the webbing W is in the winding direction, the ratchet effect of the latch plate 1b and the pawl 13 does not prevent the winding rotation by the spiral spring 4 of the reel 1, and the webbing W is smoothly wound in its entirety. be returned.

At this time, the sensing plate 18 rotates according to the amount of winding, activates the toggle switch mechanism as described above, and sets the locking method to AL.
Switch from R to ELR. In addition, if the occupant wants to switch from ELR to ALR in order to secure a child seat, etc., instead of wearing the seat belt himself, if the occupant suddenly pulls out the webbing that has been pulled out a predetermined amount, the switch can be made in the same way as described above. It will be done.

Switching from ALR to ELR is also performed in the same way if the webbing is wound up. In this way, if the webbing is pulled out to a desired value with a speed change greater than a predetermined value, it is possible to easily switch from ELR to ALR.

As described in detail above, according to the present invention, by combining an acceleration detection mechanism using inertia and a switch mechanism using a snap action, the installation space is small and the locking method between A L R and ELR can be switched off when desired. A webbing-sensing retractor suitable for use in the rear seats of automobiles and the like can be obtained at low cost. still,
It goes without saying that the present invention is not limited to the specific embodiments described above, and that various modifications can be made within the technical scope of the present invention.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing one embodiment of the present invention. 2 and 3 are respectively a plan view and a side view showing one embodiment of the present invention, FIG. 4 is an explanatory diagram showing the main parts of one embodiment of the present invention, and FIG. 6a to 6c are explanatory diagrams each showing the operation of one embodiment of the present invention, and FIG. 7 is a side view showing the operation of one embodiment of the present invention. It is a schematic cross-sectional view. (Explanation of symbols) 1a: Cylinder 1b: Latch plate 2: Shaft 9: Inertia block 12: Clutch spring 13: Lock ball 14: Lock arm 15: Swing arm patent applicant NSK Warner Co., Ltd. Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. An emergency lock retractor that automatically locks the webbing in the event of an emergency such as a collision, which includes a shaft around which the webbing is wound, and a shaft adapted to rotate the webbing in the direction in which the webbing is wound. a locking means that can be freely changed between a locking position in which the shaft only prevents rotation in the direction in which the webbing is fed out and a non-locking position in which it does not prevent rotation in both directions;
a detection means for detecting a change in the rotational speed of the shaft due to sudden unwinding of the webbing in an emergency; a detection means for detecting the amount of winding of the webbing onto the shaft; and an output from the detection means for the locking means. A retractor characterized in that it has a switch mechanism that switches from the unlocked position to the locked position and switches from the locked position to the unlocked position in response to the sensing means. 2. The retractor according to item 1 above, wherein the switch mechanism is a toggle switch mechanism.