JP2002114130A - Seat belt tension detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seat belt tension detector that can prevent an air bag from becoming operable in a situation requiring no operation thereof. SOLUTION: The seat belt tension detector 10 comprises an engaging member 11 engaged with webbing W for restraining the body of an occupant onto a seat, a base member 20 for mounting the engaging member 11 on the seat or a vehicle body mounted with the seat while allowing movement of the engaging member 11 according to tension acting on the webbing W, and a sensor means 30 for detecting a relative movement quantity between the engaging member 11 and the seat or vehicle body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat belt tension detecting device used for a seat belt device mounted on a vehicle such as an automobile.

[0002]

2. Description of the Related Art FIG. 8 shows a three-point seat belt device 90 conventionally mounted on an automobile. In the three-point seat belt device 90, the webbing 91 has one end wound around the retractor 100 so as to be able to be pulled out, the other end inserted into the through anchor 94 and the sluting 96 supported by the center pillar 98, and fixed to the vehicle body. It is locked on an anchor plate 97. Seat belt device 90
In use, the occupant engages the slutung 96 with the buckle 93 provided on the seat 95 on the side opposite to the anchor plate 97 side. As a result, the webbing 91 traverses obliquely downward in front of the seat back 95a, is folded back by the sluting 96, and traverses the front of the seat back 95a substantially horizontally along the base end of the seat back 95a (see FIG. 8). State), and the occupant seated on the seat 95 is restrained.

[0003] A child seat 110 may be attached to the passenger seat 95 in some cases. Insertion hole 112 provided in base 111 of child seat 110
And a part of the webbing 91 is inserted into the
The child seat 110 can be attached to the seat 95 by engaging the buckle 93 with the 6. The sheet 95
Can be moved back and forth by removing a seat slide lock device (not shown) provided at the lower part of the seat 95, and by moving the seat 95 forward, the child seat 110 can be moved by the webbing 91 to the seat 9.
5 can be tightened.

[0004] Recent automobiles are equipped with an SRS airbag (not shown) that swells between the occupant and the interior wall of the vehicle and catches the occupant's body in the event of a vehicle emergency such as a collision. In response to this, measures have been taken to improve occupant safety. The airbag is electrically or mechanically activated when a large acceleration acts on the vehicle due to a collision or the like. Generally, the airbag can be activated only when an occupant (adult) of a predetermined size or more sits on the seat 95. The seat 95 is provided with a predetermined detecting means such as a weight sensor for detecting that an adult is seated.

[0005]

Heretofore, it has been desired that the airbag is not operated when the child seat 110 is mounted on the passenger seat 95.
However, the child seat 110 is moved to the seat 9 by webbing of the seat belt device by the above-described method or the like.
When the seat is extremely tightly tightened, the weight sensor and other sensors may erroneously determine that an adult is seated on the seat and enable the airbag to operate. Is required.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent an airbag from becoming operable in a situation where it is not necessary to operate the airbag. To provide a seat belt tension detecting device.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a seat belt tension detecting device used in a seat belt device provided with a webbing for restraining an occupant's body to a seat, wherein an engaging member engaged with the webbing is provided. A joining member, a base member for attaching the engaging member to the seat or a vehicle body to which the sheet is attached while allowing the engaging member to move in accordance with the tension applied to the webbing, the base member, This can be achieved by a seat belt tension detecting device including a sensor means for detecting a relative movement amount with respect to a seat or a vehicle body.

According to the seat belt tension detecting device as described above, it is determined whether or not the tension is applied to the webbing or more than a predetermined time, such as when the child seat is tightly fastened to the seat. Can be detected.
Even in the event of a vehicle emergency such as a collision, the webbing is subjected to a tension greater than a predetermined value.In this case, however, the application time of the force exceeding the predetermined value and other conditions may cause the vehicle emergency such as when the child seat is tightly tightened by the webbing. Different from other times. Therefore, in a preferred configuration of the present invention, based on the difference between the force application time and other conditions during and after the vehicle emergency, it was detected that a predetermined or more tension was applied to the webbing other than during the vehicle emergency. In this case, the operation of the airbag can be prohibited by the control means. By using this seat belt tension detecting device, it is possible to reliably prevent the airbag from being operable in the seat on which the child seat is mounted.

[0009] Preferably, the engagement member, the base member and the sensor means may be connected by a flexible wire.

Preferably, the base member includes a base plate for movably guiding the engagement member, and a mounting member for attaching the base plate to a seat or a vehicle body.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In the embodiments described below, the members and the like having the same configurations and operations as the members and the like already described are denoted by the same reference numerals or corresponding reference numerals in the drawings, and the description thereof will be simplified or omitted.

FIG. 1 shows an embodiment of the present invention. The seat belt tension detecting device 10 has one end connected to the retractor 100.
Plate 11 as an engaging member engaged with the other end of the webbing W wound so as to be able to be pulled out, a base plate 20 as a base member for attaching the anchor plate 11 to the vehicle body so as to be relatively movable, and an anchor plate 11 And an electronic unit (ECU) 30 as a sensor means for detecting a relative movement amount between the vehicle and the vehicle body. Here, the retractor 100 is fixed to a pillar 98 that is a part of the body panel, and the base plate 20 and the electronic unit 30 are fixed to a side sill 99 connected to the pillar 98.

As shown in FIG. 1, the substantially rectangular anchor plate 11 is provided with an engagement hole 11a at one end in the longitudinal direction for engaging with the webbing W, and the longitudinally central portion thereof is provided with an elongated hole. A long hole 11b extending in the direction is provided, and one end of a flexible wire 25 is connected to the other end in the longitudinal direction. The anchor bolt 15 is attached to the base plate 2
In addition to penetrating through the long holes 11b of the anchor plate 11 placed on the base plate 0, the base plate 20 is also penetrated and attached to the vehicle body. FIG. 1 shows a state when the tension acting on the webbing W is small (about 1 N or less; an initial state). The anchor bolt 15 is located on the webbing W side (engagement hole 11a side) in the long hole 11b of the anchor plate 11. In other words, the anchor bolt 15 and the flexible wire 2 of the elongated hole 11b
A relative movement allowable space is formed between the end and the end on the fifth side. The flexible wire 25 having one end connected to the anchor plate 11 has the other end connected to the electronic unit 30. Between the anchor plate 11 and the electronic unit 30, the flexible wire 25 has a sufficient length (has an extra length) and is slightly bent. The electronic unit 30 is connected to a harness section (electric wire section) 30 a that supplies power to the electronic unit 30 and transmits and receives various signals. A connector (electric connection part) 30b is provided at the tip of the harness part 30a.

FIG. 2 shows a vehicle seat 95 and a seat belt device 40 provided with the seat belt tension detecting device 10 described above. One end of the webbing W of the three-point seat belt device 40 is wound around the retractor 100 so as to be able to be pulled out, and the other end is inserted through a through anchor and sluting 96 (not shown), and is engaged with the anchor plate 11. The anchor plate 11 and the base plate 20 are attached to the vehicle body by anchor bolts 15. A buckle 93 is provided on the opposite side of the seat 95 from the anchor plate 11 side. Buckle 9
3 is connected to one end of the anchor member 47. The other end of the anchor member 47 is fixed to the fixing plate 50 by an anchor bolt 49 penetrating therethrough. The fixing plate 50 is fixed to the vehicle body.

When tension is applied to the webbing W while the slutung 96 is engaged with the buckle 93, the anchor plate 11 is moved by the webbing W to the center side of the seat back 95a (the left side in the figure; the side away from the vehicle body) and It is pulled upward. Further, a tension equivalent to the tension acting on the webbing W acts on the anchor member 47, and the anchor bolt 49 and the fixing plate 50 are pulled upward.

FIG. 3 is a sectional view taken along the line III-III in FIG.
The mounting structure of the anchor plate 11 and the base plate 20 will be described with reference to FIG. This mounting structure uses an anchor bolt 1 as a mounting member.
In addition to 5, a resin washer 16 and a resin L bush 17 as a wear and abnormal noise prevention member, a waved washer 18 as an urging member, and an L bush 19 as a flange member are provided. These mounting members fix the base plate 20 to the vehicle body, and
1 is movably mounted on the base plate 20. The base plate 20 includes a back plate 20a and a pair of side plates 20b,
20b having a U-shaped cross section. Backboard 20a
Is provided with a fixing hole 20c through which the anchor bolt 15 passes. Anchor plate 11 is base plate 2
0 is slidably fitted between the side plates 20b, 20b.

The anchor bolt 15 is adjacent to the head portion 15a and has a flange portion 15b having a larger diameter than the head portion 15a, and is adjacent to the flange portion 15b and has a step portion 15c and a step portion 15c having a smaller diameter than the flange portion 15b. The shaft 15d has a smaller diameter than the step 15c. As shown in FIG.
The step 15c passes through the long hole 11b of the anchor plate 11, and the shaft 15d passes through the fixing hole 20a of the base plate 20 and is screwed to the vehicle body. The resin washer 16 is externally fitted to the step 15c of the anchor bolt 15. The resin L bush 17 having a cylindrical portion and a flange portion has its cylindrical portion fitted on the step portion 15c, and its cylindrical portion is slidably fitted on the long hole 11b of the anchor plate 11. I have. The flange portion of the resin L bush 17 is interposed between the anchor plate 11 and the back plate 20b of the base plate 20. These resin washers 1
6 and the resin L bush 17 make the anchor bolt 1
Between the anchor plate 11 and the anchor plate 11 and between the anchor plate 11 and the base plate 20 when the anchor plate 11 slides on the base plate 20 and at the same time, prevents shaving and abnormal noise due to metal contact. are doing.

The L bush 19 has a cylindrical portion and a flange portion, and the waved washer 18 is fitted on the cylindrical portion. The outer diameter of the waved washer 18 is larger than the diameter of the fixing hole 20 c of the base plate 20. When the anchor bolt 15 is screwed into the vehicle body, the tip of the cylindrical portion comes into contact with the step 15c of the anchor bolt 15. A wave washer 18 and an L bush 19 are interposed between the back plate 20a of the base plate 20 and the vehicle body. The base plate 20 and the anchor plate 11 are attached to the vehicle body so as to be rotatable around the anchor bolt 15. The wave washer 18 always urges the base plate 20 in a direction away from the vehicle body to prevent generation of abnormal noise when the base plate 20 rotates.

As shown in FIG. 4, at one end of the back plate 20a of the base plate 20, a wire guide portion 20d is provided substantially at the center between the side plates 20b, 20b. FIG.
FIG. 5 is a sectional view taken along line VV in FIG. 1. The wire guide portion 20d of the base plate 20 has a configuration in which an insertion hole for the flexible wire 25 is provided on an end wall that is raised from the back plate 20a and protrudes above the anchor plate 11. The flexible wire 25 includes a flexible metal core 25a,
And an outer tube 25b as a covering material for covering the core material 25. The outer tube 25b is connected to the wire guide portion 20.
A portion adjacent to the outside of d is bent to form a bulge portion 25c as a locking portion. The end of the core material 25 a is locked on the upper surface of the anchor plate 11 by a locking member 26. On the lower surface (the surface facing the back plate 20a of the base plate 20) on the opposite side (the right side in the figure) of the anchor plate 11 to the side where the webbing W is engaged, a guide projection 11c that comes into contact with the back plate 20a is provided. Is provided.

When a predetermined tension or more acts on the webbing W, the anchor plate 11 is moved by the webbing W in the direction of the arrow P1 (left direction in the figure), which is the plane direction of the anchor plate 11, or in the plane direction of the anchor plate 11. On the other hand, when the anchor plate 11 is pulled in the direction of the arrow P2 in the drawing, which is a direction inclined away from the vehicle body, only the anchor plate 11 is guided between the side plates 20b of the base plate 20, and moves in the direction of the arrow P1 in the drawing. That is, the anchor bolt 1
5 and the base plate 20 do not move, and the resin L bush 17 externally fitted to the anchor bolt 15 relatively slides in the long hole 11b of the anchor plate 11. When the anchor plate 11 is pulled toward the center and upward of the seat back 95a (see FIG. 2), an arrow P2 shown in FIG.
The anchor plate 11 is pulled in the direction of. At this time, the upward movement in FIG. 5 of the anchor plate 11 is regulated by the resin washer 16 abutting on the flange portion 15 b of the anchor bolt 15, and the guide protrusion 11 c is attached to the back plate of the base plate 20. Since it is in contact with the upper surface 20a, it moves smoothly in the direction of arrow P1 without tilting in the direction of arrow P2.

FIG. 6 is a sectional view taken along the line VI-VI in FIG. The case of the electronic unit 30 is formed by combining an upper case 31 and a lower case 32. Lower case 32
Can be formed by press working or the like, and includes a back plate 32a and a side plate 32b. A coil spring 33 as an urging member and a cap member 34 as a moving member are housed in the lower case 32. The cap member 34 is
Cylindrical cup part 34a with a bottom and lid part 3 as a contact part
4b. The lid 34b can be formed by resin molding or the like.

A coil spring 33 is provided between the bottom plate of the cup portion 34a of the cap member 34 and the side plate 32b of the lower case 32.
Is interposed. On the surface of the lid portion 34b fitted into the opening of the cup portion 34a on the side opposite to the coil spring 33 side,
The shaft 38a which is a sensing part of the linear potentiometer 38 is in contact with the linear potentiometer 38. The axial direction of the shaft 38a substantially matches the axial direction of the coil spring 33. The lid portion 34b of the cap member 34 is provided with a slip prevention protrusion 34c so as to surround the tip of the shaft 38a.
The linear potentiometer 38 is fixed to the lower case 32 by screwing or the like. Upper case 31
Are the lower case 32 and the linear potentiometer 38
And a side plate 31b that covers the top plate 31a. The upper case 31 can be formed by press deep drawing, resin die casting, or the like.

To penetrate the core material 25a of the flexible wire 25 and the outer tube 25b through the side plate 31b of the upper case 31 and the side plate 32b of the lower case 32, each side plate 3
1b and 32b have opposite U-shaped notches (not shown)
Is provided. Outer tube 25 of flexible wire 25
As for b, a portion adjacent to the outside of the side plate 31b of the upper case 31 is bent to form a bulge portion 25c. The core material 25a passes through the coil spring 33 in the axial direction, penetrates the bottom plate of the cup portion 34a, and terminates in the cup portion 34a. At the end of the core material 25a, a terminal locking portion 25d having a larger diameter than the core material 25a is provided. In the initial state, as shown, a gap S is provided between the terminal locking portion 25d disposed in the cup portion 34a and the bottom plate of the cup portion 34a.
Is open. Further, the coil spring 33 is not compressed.

The linear potentiometer 38 is connected to control means as shown in FIG. An output from the linear potentiometer (sensor means) 38 is sent to a central processing unit (hereinafter, “CP”) via an input / output interface 54.
U ”). The CPU 51 is connected to a memory 56, a timer 57, an operation prohibition unit 58 for disabling the operation of the airbag, and the like. The CPU 51 performs processing such as judging that a predetermined or more tension has acted on the webbing other than in an emergency of the vehicle, based on the states of the sensor means 38 and the timer 57 and the like. The processing program and various data are stored in the memory 56. CPU
When it is determined that a predetermined or more tension has acted on the webbing other than when the vehicle is in an emergency, the command 51 issues a command to the operation prohibition unit 58 to disable the operation of the airbag.

Returning to FIG. 1, the operation of the present embodiment will be described. Since the flexible wire 30 between the anchor plate 11 and the electronic unit 30 has an extra length, the anchor plate 11 and the base plate 20 are fixed by the anchor bolts in accordance with the movement of the webbing W as shown by the arrow R in the figure. 15 can be rotated by a predetermined amount. When the anchor plate 11 and the base plate 20 are rotated, the core material 25a of the flexible wire 25 may be pulled by the anchor plate 11, but as shown in FIG. Since the gap S is provided between the linear potentiometer 38 and the cup portion 34a, the linear potentiometer 38 does not malfunction due to such disturbance.

Then, the child seat is webbed W
The webbing W is attached to a sheet, and the webbing W has a predetermined tension or more (for example, a tension ten times or more the initial state; 20 N to 2).
When a tension of about 00N is applied, the anchor plate 11 is pulled by the webbing W, and the anchor plate 11 moves relative to the vehicle body. Then, in the electronic unit 30 shown in FIG. 6, the terminal locking portion 25d of the flexible wire 25 abuts against the bottom plate of the cup portion 34a, and the cap member 34 resists the urging force of the coil spring 33 by the flexible wire 25. And then move to be pulled. Accordingly, the shaft 38 of the linear potentiometer 38
a extends and outputs a voltage (current) change corresponding to the relative movement between the anchor plate 11 and the vehicle body to the control means.
The linear potentiometer 38 is not the amount of change in the position of the terminal locking portion 25d of the flexible wire 25, but the coil spring 33.
By measuring the amount of change in the position of the cap member 34 equivalent to the amount of change in the terminal position, the tension applied to the webbing W can be accurately, electrically, and linearly detected.

An example of the processing in the control means shown in FIG. 7 will be described. First, the CPU 51 determines whether the state in which the output value from the linear potentiometer (sensor means) 38 exceeds the threshold has continued for a predetermined time (for example, one minute or more). If the CPU 51 determines that it has continued,
The PU 51 issues a command to the operation prohibition unit 58 to stop the operation of the airbag.

The emergency locking means of the retractor 100 is activated in the event of a vehicle collision, sudden braking, light collision, etc., even when the occupant is restrained by the webbing W, not when the child seat is attached to the seat, and the occupant is in front of the occupant. The webbing W is tensioned by the movement. That is, high tension acts on the webbing. Hereinafter, this is referred to as a normally used high tension state. However, the time during which the tension acts at this time is shorter than the time during which the tension acts on the webbing W when the child seat is mounted on the sheet.

Therefore, according to the seat belt tension detecting device 10 of the present embodiment, it is possible to detect that a predetermined or more continuous tension acts on the webbing W continuously for a long time, such as when a child seat is worn, and it is possible to detect a normal use high tension. State
The webbing W can be reliably distinguished from the case where the child seat is mounted on the passenger seat or the like. And
When the child seat is mounted on the passenger seat, the operation of the airbag can be prohibited by the control means.

It should be noted that the present invention is not limited to the above-described embodiment, and appropriate modifications and improvements can be made. For example, the seat belt tension detecting device can be connected to a driving recorder or the like. For example, the anchor plate 11, the base plate 20, and the electronic unit 3
0 may be provided in the same case, and the seat belt tension detecting device may be configured as one unit. For example, the present invention can be applied to a buckle mounting structure of a seat belt device.

[0031]

As described above, by using the seat belt tension detecting device of the present invention, it is possible to reliably prevent the air bag from being operable in a situation where it is not necessary to operate the air bag.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a front view showing a seat and a seatbelt device using one embodiment of the present invention.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

FIG. 4 is an exploded perspective view illustrating an attachment structure of an anchor plate and a base plate.

FIG. 5 is a sectional view taken along line VV in FIG. 1;

FIG. 6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 is a block diagram showing an electrical schematic configuration of an embodiment of the present invention.

FIG. 8 is a diagram illustrating a state in which a child seat is mounted on a passenger seat.

[Explanation of symbols]

 Reference Signs List 10 seat belt tension detecting device 11 anchor plate (engaging member) 11b long hole 15 anchor bolt (base member) 20 base plate (base member) 25 flexible wire 30 electronic unit (sensor means) 57 timer (timer means) W webbing

Claims (1)

[Claims] 1. A seat belt tension detecting device used in a seat belt device provided with webbing for restraining an occupant's body to a seat, comprising: an engaging member engaged with the webbing; and the webbing of the engaging member. A base member for attaching the engaging member to the seat or a vehicle body to which the seat is attached, and a relative movement amount between the engaging member and the seat or the vehicle body while allowing movement according to the tension applied to the seat. A seat belt tension detecting device comprising a sensor means.