JPS6036972B2 - Seat belt retractor - Google Patents

Description

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

Conventionally, a winding device such as a retractor that automatically winds up a seat belt simply uses one spiral spring.
The central machine is attached to a winding shaft, and its outer peripheral end is fixed to a spring case installed in the main body of the winding device, and the seat belt is unwound from the winding device, thereby retightening the mainspring spring, and this operation causes the seat belt to tighten. It was common to apply a winding force to the However, in such conventional devices, the mainspring spring is tightened as the seatbelt unwinds, so the retracting force generally increases as the seatbelt unwinds. Belt systems in which the seatbelt is unrolled and worn have the disadvantage that the winding force is too strong when the seatbelt is worn, increasing the feeling of restraint on the occupant and impairing usability. In particular, when a lap belt or a shoulder belt is made of 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 seatbelt will be insufficient when the seatbelt is retracted. On the other hand, if the belt winding force is set to be the same as when the vehicle is stored, the restraint force upon restraining the occupant becomes too strong, resulting in extremely poor usability. Furthermore, in a bathshuff belt system in which the amount of belt winding increases, the usability becomes even worse. In order to eliminate these drawbacks, those skilled in the art have developed a spring means in which a first spring and a second spring are connected in series, a connection part such as a latch gear connected to the spring means, and a connection part such as a latch gear that is connected to the spring means, and a connection part such as a latch gear that is rotatably operated to connect the lock. A winding device has also been proposed, which consists of a ratchet that is controlled by a ratchet, and a control section that controls the ratchet according to the state of belt unwinding, so that the belt tension can be changed according to the state of belt unwinding. However, the configuration of the control section is complicated and large, which poses a major constraint when installed in a vehicle. In order to solve the above-mentioned drawbacks, the present invention provides a first spring and a second spring.
a spring means for applying a belt winding force by connecting a second spring having a weaker spring force than the spring to the winding shaft in parallel; and a spring force control section for controlling the direction in which the spring force is applied to the second spring. By configuring the belt winding force according to the belt unwinding state to be the resultant force of the first spring and the second spring when stored, and the differential force between the first spring and the second spring when restrained,
It is an object of the present invention to provide a seat belt retractor that reduces the belt winding force during restraint, further increases the belt winding force when stored, and has a simple configuration, small size, and better belt tension characteristics. It is something to do. Embodiments of the apparatus of the present invention shown in the drawings will be described below.

An embodiment of the present invention will be described with reference to FIGS. 1 to 7. Reference numeral 1 denotes a main body of a winding device such as a retractor, which rotatably suspends a winding shaft 2, which will be described later, and outside the main body 1. It is configured so that each component described later can be attached to the mounting hole la, the side frame lb, and a horizontally long hole suspension part l for suspending a gear shaft 8, which will be described later.
It consists of c, etc. 2 is a winding shaft which connects the main body 1
It is suspended so as to be freely rotatable, and fixes a take-up reel 3, which will be described later.One end has a first spring 5, which will be described later, suspended by a slit part 2a, and the other end has a first gear part 2b and a second gear part 2c. It has the following.

Reference numeral 3 denotes a take-up reel for winding up a seat belt 4, which will be described later, which is fixed to the take-up shaft 2 and has a latch gear 3a.

4 is a seat belt for restraining the occupant; one end is suspended on the take-up shaft 2 and taken up on the take-up reel 3; the other end is connected to an anchor via a slip joint (not shown); the entire seat belt is The system is configured.

Reference numeral 5 denotes a first spring stored in a barrel 6, which will be described later. Its outer peripheral end is fixed to the main body 1' via the barrel 6, and its center end is suspended in a slit 2a of the winding shaft 2.

The first spring 5 continuously rotates the winding shaft 2 into the seat belt 4
This applies a spring force in the direction of winding up the material. Reference numeral 6 denotes a barrel to which the outer peripheral end of the first spring 5 is fixed and for housing the first spring 5, and is fixed to the side frame lb of the main body 1.

Reference numeral 7 denotes a barrel gear rotatably suspended on a gear shaft 8, which will be described later.

The gear portion 7a is the gear portion that meshes with the first gear portion 2b of the cover removal shaft 2 via an intermediate gear 14, which will be described later.
A gear portion that directly engages with the second gear portion 2c of the winding shaft 2 is the second gear portion 7b. Furthermore, it has a barrel part 7c which stores a second spring 9, which will be described later, and suspends the outer peripheral end thereof. Reference numeral 8 denotes a gear shaft for rotatably suspending the barrel gear 7, one end of which is suspended by a housing 18, which will be described later, and the other end of which is suspended by a suspension portion lc of the main body 1.

Furthermore, although the gear shaft 8 does not rotate relative to the main body 1, it can only move in the left-right direction in FIG. It is biased toward the right, that is, toward the winding shaft 2 side. Reference numeral 9 denotes a second spring having a weaker spring force than the first spring 5, and its outer peripheral end is fixed to the barrel part 7c of the barrel gear 7, and its center end is fixed to the slit part 8 of the gear shaft 8.
a, and constantly biases the barrel gear 7 in the counterclockwise direction in FIG. 2 with a spring force.

Reference numeral 10 denotes a detection lever fixed to a lever shaft 11 to be described later, which detects the amount of winding of the seat belt, and has a spring property.

Reference numeral 11 designates a lever shaft that suspends the detection lever 10, is rotatably suspended from the side frame 1 of the main body 1, and has a galley lever 13 (described later) fixedly suspended at the end on the side of a housing 18 (described later).

Reference numeral 12 denotes a turn spring that constantly applies a spring force to a galley lever 13, which will be described later, in the clockwise direction in FIG.

Reference numeral 13 denotes a galley lever having one end fixed to the lever shaft 11 and a pin 15, which will be described later, fixed to the other end.

Reference numeral 14 denotes an intermediate gear that is rotatably suspended on a pin 15, which will be described later, and that meshes with the first gear part 2b of the winding shaft 2 and the first gear part 7a of the barrel gear 7.

A pin 15 is fixed to the galley lever 13 and rotatably suspends the intermediate gear 14.

A stopper 16 is fixed to the side frame lb of the main body 1 and restricts the rotation range of the gear lever 13.

17 is a spring suspended between the winding shaft 2 and the gear shaft 8, and the gear shaft 8 is constantly moved to the winding shaft 2.
A spring force is applied to the side.

Reference numeral 18 denotes a housing fixed to the side frame lb of the main body 1, and has a suspension portion 18a for suspending the gear shaft 8 so as to be movable in the left-right direction in FIG.

The operation of one embodiment of the above configuration will be explained below. First, the belt unwinding operation for the occupant to fasten the seat belt will be explained based on FIGS. The galley lever 13 is positioned as shown in FIG. Therefore, the intermediate gear 14 includes the first gear portion 2b of the winding shaft 2 and the first gear portion 7a of the barrel gear 7.
It is in a free state without interfering with it. However, the barrel gear 7 is on the winding shaft 2 side due to the spring force of the spring 17, and the second gear portion 2c of the winding shaft 2 and the barrel gear 7b are in mesh as shown in FIGS. 5 and 6. . The tension T of the seat belt 4 in this state is as follows. Since the second spring 9 applies its spring force to the barrel gear 7 in the counterclockwise direction in FIG.
The spring force of spring 9 acts in a clockwise direction. Since the spring force of the 11th spring 5 also acts clockwise on the winding shaft 2, the spring force of the 1st spring 5 is T, and the spring force of the 21st spring 9 is T.
2, the tension T becomes T, 10 T2, and if the seat belt 4 is pulled out by overcoming the tension T of the seat belt 4, unwinding is possible. When the seat belt 4 is unwound in this manner, the amount of the seat belt 4 taken up on the take-up reel 3 decreases. It begins to rotate clockwise as shown in Figure 6. When the winding amount decreases to the amount L shown in Fig. 7, the lever shaft 1
1 rotates to a position where it engages with the intermediate gear 14, the first gear portion 7a of the barrel gear 7, and the first gear portion 2b of the winding shaft 2. At this time, the spring force of the eleventh spring 5 and the second spring 9 further rotates the intermediate gear 14 in the clockwise direction, resulting in a fully meshed state as shown in FIGS. 1 and 4. Intermediate gear 1
4, the gal lever 13 is restrained by the stopper 16, so that it does not rotate any further in the clockwise direction. Furthermore, due to the meshing of the intermediate gear 14, the meshing between the second gear portion 2c of the winding shaft 2 and the second gear portion 2b of the barrel gear 2 as shown in FIGS. 5 and 6 is released. . In this way, when the intermediate gear 14 is engaged, the tension T (FIG. 7) of the seat belt 4 is applied to the winding shaft 2 by the spring force of the second spring 9 via the intermediate gear 14, and in the opposite direction. The spring force becomes , and the torque difference between the first spring 5 and the second spring 9 becomes T, -T2. In other words, as shown in FIG. 7, the tension T of the seat belt 4 is reduced in the range where the force ratio of the winding amount L is further reduced. Therefore, if the winding amount L of the seat belt 4 at the wearing position of the seat belt 4 when the passenger is in the vehicle is less than or equal to L, the feeling of restraint given to the passenger is reduced, and the seat belt 4 can be worn without discomfort. Further, when the occupant moves by operating the front panel switches, the intermediate gear 14 is in mesh with the first gear portion 2b of the winding shaft 2 and the first gear portion 7a of the barrel gear 7, so that the seat belt 4 The tension remains reduced and there is no problem. Next, the process of releasing the seat belt 4 will be explained.

When a buckle (not shown) or the like is unlocked, the seatbelt 4 moves to the first gear of the winding shaft 2, as shown in FIG.
Since the gear portion 2b and the first gear portion 7a of the barrel gear 7 are in mesh with each other, the gear is wound onto the take-up reel with a spring force of T, -T2. When the winding amount of the seat belt 4 reaches L, the detection lever 10 rotates the lever shaft 11 counterclockwise, and the intermediate gear 14 is connected to the first gear portion 2c of the winding shaft 2 via the galley lever 13. The engagement state of the barrel gear 7 with the first gear portion 7a is released. At the same time, barrel gear 7
is moved to the right in FIG. 4 by the spring force of the spring 17, and the second gear portion 2c of the winding shaft 2 and the second gear portion 7b of the barrel gear 7 mesh with each other. The tension of the seat belt 4 becomes T, T2 again, and the seat belt 4 is wound up by this tension. The seat belt 4 is also at the retracted position T, 10 T2, and has sufficient tension for retracting. The key points for understanding the above embodiment are as follows.

A first spring 5 is coupled to one end of the winding shaft 2, and a first gear portion 2b and a second gear portion 2c are coupled to the other end. The barrel gear 7 is rotatably provided on a gear shaft 8. The barrel gear 7 has a gear part 7a that engages with the first gear 2b via an intermediate gear 14, and a gear part 7b that directly and selectively (moves) engages with the second gear part 2c. The second spring 9 is housed in a barrel part 7c that is integrated with the barrel gear 7, and one end 9a is fixed to the barrel part 7c and the other end 9b is fixed to the gear shaft 8. The second spring 9 acts to rotate the barrel gear 7 counterclockwise in FIG. Reference numeral 12 denotes a return spring which acts to rotate the galley lever 13 clockwise in FIG.

A pin 15 is fixed to the other end of the galley lever 13.
17 (Fig. 1, Fig. 6) is the gear shaft 8 with a spring.
It works to move the winding shaft to the winding shaft 2 side.

18a has a slit shape.

When the belt is first unwound, it is in the position shown in Figure 6.

At this time, the intermediate gear 14 does not mesh anywhere. When the belt is unwound to a certain extent, the amount of belt winding decreases, so the bar shaft 11 rotates and engages the intermediate gear 14, the gear part 7a of the barrel gear 7, and the first gear part 2b. As a result, the shaft 8 moves to the left, and the second gear portion 2c no longer engages with the gear portion 2b of the barrel gear 2. In this state, the spring force of the second spring 9 is applied to the shaft 2 in the opposite direction via the intermediate gear 14, and the tension becomes T, -T2. However, in the above configuration, the spring force control section that controls the second spring force application direction serves as belt winding state detection means (
It mainly consists of a lever shaft 11, a gear lever 13, a return spring 12), and one of the application direction transmission mechanisms (the gear part 2b of the winding shaft 2, the intermediate gear 14, and the gear part 7a of the barrel gear 7). . Note that the present invention is not limited to the above-mentioned embodiment; for example, the intermediate gear 14 is rotated using a detection lever that detects the amount of winding of the seat belt 4; Of course, it is also possible to detect the rotational speed and drive the intermediate gear 14 using a cam mechanism or the like, or to electrically or mechanically detect the displacement when inserting the tongue plate into a buckle or the like to control the intermediate gear. be.

Further, the second spring 5 has its outer peripheral end suspended on the barrel gear 7 and its center end fixed to the main body 1 via the gear shaft and the housing. may be fixed to the main body 1 via the housing. Furthermore, although the direction of applying the spring force to the second spring 5 was changed by rotating the intermediate gear 14, the intermediate gear 14 was fixed and the barrel gear 7 was changed.
It is also possible to move the gears in the vertical direction in FIG. 1 to control the engagement of the respective gear parts. As described above, in the present invention, a first spring and a second spring having a weaker spring force than the first spring are connected in parallel to the winding shaft to apply a belt winding force, and the spring means 2. Spring force control that controls the direction of application of the upward spring force.Depending on the belt unwinding state, the belt winding force is the resultant force of the first spring and the second spring when retracted, and the resultant force of the first spring and the second spring when the occupant is restrained. By configuring the second spring to have a differential force, it has the excellent effect of reducing the belt winding force during restraint and further increasing the belt winding force when stored.

Moreover, the structure is simple and can be made small, which is an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of the device of the present invention viewed from the plane, FIG. 2 is a cross-sectional view taken along the arrow line B--B shown in FIG. 1, and FIG. 3 is a cross-sectional view taken along the arrow shown in FIG. A cross-sectional view along line C-C,
Figure 4 is a sectional view taken along the arrow A-A line shown in Figure 1;
The figure is a sectional view taken from the plane after the work as shown in Figure 1, Figure 6 is a sectional view taken along the arrow A'-A' line shown in Figure 5, and Figure 7 is the apparatus shown in Figure 1. FIG. 2... Winding shaft, 4... Belt, 5... First pan, 9... 25th copy, 11, 13, 12...
In particular, the lever shaft 1 serves as a belt winding state detection means.
1, gear lever 13, return spring 12, 2c,
7b... Particularly the gear part 2 which becomes one of the application direction transmission mechanisms
c, gear parts 7b, 2b, 14, 7a...particularly gear part 2b, intermediate gear 14, gear part 7 which becomes the other application direction transmission mechanism
a. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Scope of Claims] 1. Spring means for applying a winding force to the seat belt by connecting a first spring and a second spring having a weaker spring force than the first spring in parallel to a winding shaft, and the second spring a spring force control unit that controls the spring force application direction of the spring force, and applies a resultant force to the first spring and the second spring when the seat belt is in the retracted state; A seat belt retractor characterized in that a differential force of a second spring is applied to the seat belt. 2. The spring force control unit includes a seatbelt winding state detection means, a transmission mechanism that applies and transmits the spring force of the second spring to become a resultant force with respect to the spring force of the first spring, and a spring force of the second spring. The seatbelt retractor according to claim 1, further comprising a transmission mechanism that applies and transmits force so as to be a differential force with respect to the spring force of the first spring.