JPS63188548A - Tension lock retractor for cam mechanism type seat belt - Google Patents

Abstract

PURPOSE:To enable temporary retention of winding rotation during the action of an electromagnetic drive means and to prevent production of an oppressive sensation, by a method wherein a cam, rotating a cam plate for controlling a lock means, is provided with a claw part, engaged with a control lever, and an arcuate inner peripheral part causing engagement of a friction clutch. CONSTITUTION:A winding shaft 3, formed integrally with a reel, is rotatably supported to a machine frame 1 formed in a U-shape in cross section, and a base 6 of a belt winding mechanism is disposed to the one end side of a shaft 3. A friction clutch 9, a gear 10, and a cam 12 are orderly engaged with the shaft 3, and the cam 12 is engaged with the friction clutch 9 and is rotatable in a specified range. A swing plate 17, a gear 18, and a cam plate 19, with which a lock mechanism is formed, are respectively rotatably engaged with a shaft protrusion 6g of the vase 6. Rotation of the cam 12 causes unwinding of a seat belt, and can be inhibited by a control lever 26 during winding. The cam 12 is provided with a pair of claw parts 12e and 12f, engaged with and disengaged from the control lever 25, and an arcuate inner peripheral part 12d causing engagement of the friction clutch 9.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tension lock retractor for seat belts.
Regarding.

[Prior art] Generally, tension lock retractors for seat belts
This is a tractor that eliminates the feeling of pressure from the seat belt by locking the seat belt so that no winding force is generated after the seat belt is fastened. Various types of towing tractors of this type are available, but generally they have an electromagnetic drive means that is energized and excited by a switch that is turned ON when the tongue of the seat belt is inserted into the buckle, and the operation of the electromagnetic drive means is controlled. After the seat belt is temporarily held in place and the seat belt is fitted to the wearer, when the wearer pulls out the seat belt a certain amount, the operation of the electric ia drive means is terminated, and the tension lock mechanism engages with the seat belt retracting shaft. However, the winding shaft is locked so that only a certain amount of drawers can be drawn out and the winding can be performed (for example, the
(See Publication No. 4015).

[Problems to be Solved by the Invention] However, according to the above-mentioned conventional technology, after the electromagnetic drive means operates, it is temporarily held in place so that the tension lock mechanism does not immediately engage with the winding shaft. The mechanical structure is complex and the number of parts is large, making it difficult to assemble, which inevitably increases manufacturing costs.
Due to the high unit price, it could not be used for anything other than luxury cars. In addition, due to the complex configuration and large number of parts,
The degree of freedom in the design of the retractor is reduced.

This has also been an obstacle to reducing the size and weight of the retractor.

[Means for Solving the Problems] The present invention has been made to solve the above problems, and includes a friction clutch that is driven by rotation of a winding shaft of a sorting belt;
A cam that engages with this friction clutch and can rotate within a certain range, and a cam that engages and disengages from this cam to prevent rotation of the cam when the seat belt is pulled out and retracted, and a cam that engages with and disengages from this cam to prevent rotation of the cam when the seat belt is pulled out and retracted. A cam plate having a control lever that allows rotation of the cam, an electromagnetic drive means that rotates the control lever, and a locking means that is rotatable by engaging with the cam and is detachable from the winding shaft. Tension lock retractor for seat belts comprising:
The cam has a cam protrusion protruding from its surface that engages with the cam plate, and a spring hook protrusion of a spring that biases rotation in one direction and a portion of the control lever on its circumferential side. The friction clutch has a pair of spaced apart claw parts that engage and disengage, while the back surface has an arc-shaped inner peripheral part that engages a part of the friction clutch, and stopper parts that protrude on both sides of the arc-shaped inner peripheral part. This is a cam mechanism type tension lock retractor for seat belts.

[Operation] According to the above structure of the present invention, the cam is rotated by the friction clutch that follows the rotation of the take-up shaft, the cam plate that engages with the cam is rotated, and the locking means is rotated by the rotation of the take-up shaft. Allows and locks only within a certain range. In this case, the cam is held by the control lever to allow the winding rotation of the winding shaft without being rotated immediately by the operation of the electromagnetic drive means, and rotates only after the seat belt is pulled out by a predetermined amount again. A locking means is engaged with the take-up shaft. To this end, the cam has an arcuate inner circumferential surface that engages with a part of the friction clutch, a stopper part that protrudes on both sides of the arc, and a pair of pawl parts that engage and disengage with a part of the control lever, and a cam. It has a spring-loaded protrusion that rotates in a certain direction.

[Example] The present invention will be explained below based on illustrated embodiments.

FIG. 1 is an exploded perspective view, FIGS. 2 and 3 are partial front and rear views, and FIGS. 4 to 6 are action explanatory views.

In FIG. 1, a reel 2 is integrally and rotatably supported with a winding shaft 3 (hereinafter simply referred to as "shaft 3") on a base frame 1 having a U-shaped cross section. A webbing sensor 4 and a belt winding mechanism 5 are fixedly provided to the base frame l.

To explain the belt winding mechanism 5, a base 6 made of a synthetic resin plate having approximately the same shape as the side surface 1a of the base frame l has a claw 6a.
It is configured so that it can be attached and fixed to the side surface 1a via the screw hole 6b. One side of the base 6 includes a mounting portion 6c for fixing an electromagnetic drive means 23 such as a solenoid, a circular hole 6d through which the shaft 3 passes, and an oblong hole 6 drilled near the circular hole 6d.
e, a holding guide portion 6f having a hook-shaped cross section, and a plurality of shaft protrusions 6g to 6j are provided, respectively. A disc spring 7 fitted onto the shaft 3 is loosely fitted into the circular hole 6d, and a coil spring 8 and a friction clutch 9 are loosely fitted onto the shaft 3 in contact with the disc spring 7. A gear 10 is secured to the outside of the friction clutch 9 by an E-ring 3e, and a shaft hole 1 is fitted into the irregular cross section 3a of the shaft 3.
It is integrally rotatably engaged with the shaft 3 via 0a. Further, a cam 12 is rotatably loosely fitted to the shaft 3 on the outside of the gear IO, and a case 13 is fitted on the outside of the cam I2.

The case 13 is mounted on the base 6 and fixed through diagonally located screw holes 13a, 13a, and is integrally formed with a spring seat 13c centered on the hole +3b in the substantially central portion from which the shaft 3 protrudes. A spiral spring 14 is placed on the spring seat 13c, and the inner end 14a of the spring 14 is inserted into the groove 11a of the roller 11 and the groove 3b of the shaft 3. The roller 11 is fitted into the irregular cross-section portion 3C of the shaft 3 and can rotate integrally therewith.

The outer end portion 14b of the mainspring spring 14 is engaged with and fixed to a fastening portion 15a provided on the inner peripheral surface of the housing I5 that crowns the spring seat 13c of the case 13. Numeral 16 is a screw, which is inserted into the screw hole 15b of the housing 15 and the screw hole 13a of the case 13 and the screw hole 6b of the base 6.
and the screw holes 1b of the base frame 1 to fix the four parts together.

The friction clutch 9 and the cam 12 are in a certain interlocking relationship, and the friction clutch 9 has a rising projection 9a projecting in the radial direction, and as shown in FIGS. 2 and 3, the cam 12 has a rising protrusion 9a. Cam protrusion 12a and the rising protrusion 9a
An arcuate inner circumferential portion +2b is formed to engage the arcuate inner circumferential portion +2b, and stopper portions 12c, 1.2 are provided at both ends of the arcuate inner circumferential portion 12b.
d, and the rising protrusion 9a can rotate between the stopper portions 12c and 12d. Further, the cam 12 is integrally formed with claw portions 12e, 12f and a spring hook portion I2g which protrude in the radial direction on the outer peripheral portion thereof.

On the other hand, on the shaft protrusion 6g on the base 6 is a rocking plate 17 that constitutes the locking mechanism 5a. The gear 18 and the cam plate 19 are each rotatably fitted loosely, and the cam plate 19 is prevented from slipping out between it and the shaft projection 6g. The swing plate 17 is 1.
Projections 17a, 17a are fitted with springs 20 that press against the gear 18 to prevent over-rotation, a stopper pin 17b is contacted by a projection 18a protruding from the circumferential side of the gear 18, and the gear 2
The gear 18 has eight teeth on the circumferential side, and the gear 21 has a cylindrical portion 21a that accommodates the mainspring spring 22. and a protrusion 21b that protrudes longer than the tooth in the radial direction.
The gear 21 meshes with the gear 10 and can rotate, and the protrusion 21b meshes with the gear 18, so that one rotation of the gear 21 causes the gear 18 to rotate by one tooth. The cam plate 19 has a shaft hole 19a into which the shaft projection 6g is loosely fitted, a shaft hole 19b into which the shaft projection 17c of the rocking plate 17 is fitted, and a cam hole 19c into which the projection 12a of the cam 12 is fitted.

Furthermore, an electromagnetic drive means 23 is mounted on the mounting portion 6C of the base 6, and one end of the control lever 25 is connected to the plunger 24a of the solenoid 24 through a long hole 25a and a pin 26.
It is rotatably attached via the shaft. control lever 25
supports the control spring 27 at the other end, and is integrally formed with a spring seat 25b rotatably supported by the shaft protrusion 6j of the base 6, and is provided with a protruding spring hook 25c. The control spring 27 is a coiled spring having one hook-shaped end 27a and the other end 27b. A coil spring 28 is elastically mounted between the spring hook projection 25c and the shaft projection 6h of the base 6, and the control lever 25 is biased to rotate in the counterclockwise direction in the drawing about the shaft projection 6j. Further, a coil spring 29 is elastically loaded between the spring hooking protrusion 12g of the cam 12 and the shaft projection 61 of the base 6, and the cam 12 is biased to rotate in the counterclockwise direction in the drawing about the shaft 3. .

Incidentally, on the base 6, similar to the shaft projections 6g to 6j, a stopper pin 6 in the shape of a shaft projection with a low height is provided with 6f2 protrudingly provided at a distance. A stopper pin 6 612 restricts the spring hooking protrusion 12g of the cam 12 so that it can rotate only between them. Further, the base 6 is provided with a predetermined length of a mold 6e centered around the shaft protrusion 6g within the locus of rotation of the protrusion 18a of the gear 18. A fumigation 1c matching this fumigation 6e is bored in the side surface 1a of the base frame l, and an actuating piece 30 protrudes outward from the base 6 from these fumigation 1c and 6e.
A limit switch with 3! is attached and fixed to the back surface of the side surface 1a of the base frame l via screws 32. The limit switch 31 is connected in series to the electric wiring when a buckle switch (not shown) is turned on to energize the electromagnetic drive means 23. When the actuating piece 30 is in contact with the circumferential surface of the gear 18, it is in an ON operating state (normally closed), and is in an O'FF operating state at the protrusion 18a of the gear 18. The operating piece 30 is required to be able to turn on and off without any trouble by rotating the protrusion 18a in the forward and reverse directions.

Next, the operation of the retractor according to the above configuration will be explained based on FIGS. 4 to 6. As shown in FIG. 4, the seat belt 34 is normally pulled out and retracted when the buckle switch is in the OFF state, so the electromagnetic drive means 23
is in the OFF operating state, and the lever 25 and spring seat 25
b does not rotate around the shaft protrusion 6j, therefore, one end 27b of the control spring 27 is caught on the claw portion 12f of the cam 12, and the clockwise rotation of the cam 12 is restrained. 19 rotates clockwise around the shaft protrusion 6g,
Gear IO is disengaged from gear 21. Furthermore, the protrusion 18a of the gear 18 contacts the stopper pin 17b to prevent counterclockwise rotation, and the protrusion 21b of the gear 21 is located on a line connecting the centers of movement of the gear 18 and the gear 21.

In this state, when the seat belt 34 is pulled out,
Since the friction clutch 9 in sliding contact with the shaft 3 rotates as the shaft 3 rotates clockwise, the rising protrusion 9a hits one stopper portion 12b of the cam 12, causing the cam 12 to rotate clockwise around the shaft 3. . However, the other end 27b of the control spring 27 abuts the claw portion 12f of the cam 12, preventing its clockwise rotation and maintaining its original state. on the other hand,
Since the shaft 3 can continue to rotate clockwise, a predetermined amount of the seat belt 34 is pulled out.

Next, when the seat belt 34 stops being pulled out, a tongue (not shown) is inserted, and the buckle switch is turned on, the electromagnetic drive means 23 is energized, and the plunger 2
4a is attracted to the right in the figure. However, the other end 27b7 of the control spring 27! l<claw portion 12 of cam I2
f, the lever 25 is forced to rotate only a certain amount around the shaft protrusion 6j and then stop. Since the state shown in FIG. 4 continues, the seatbelt 3
The remaining length of 4 is wound onto the reel 2 rotated by the shaft 3 by the force of the mainspring spring 14. At this time, as shown in FIG. 5, the shaft 3 rotates counterclockwise, so the friction clutch 9 rotates counterclockwise, and the rising protrusion 9a of the cam 1 rotates.
Move the arcuate inner circumferential portion 12b of the second stopper portion 12 to the other stopper portion 12
At point d, the cam 12 rotates counterclockwise until its spring hook protrusion 12g comes into contact with the stopper pin 6k, and the other end 27b of the control spring 27 is thereby removed from the cam 12.

Therefore, the lever 25 rotates clockwise due to the continuous suction force of the plunger 24a, moving to the right through its full stroke, and the one end 27a of the control spring 27 approaches the cam 12. After this, the seat belt 34 is wound up until it fits the wearer. and,
Once the seat belt 34 is fitted to the wearer, the wearer then leans his/her body slightly forward and pulls out the seat belt 34 again by a predetermined length. As a result of this operation, as shown in FIG. 6, the shaft 3 rotates clockwise again, the friction clutch 9 follows it and rotates clockwise, and the rising protrusion 9a moves along the arcuate inner circumference 12b, causing the shaft 3 to rotate clockwise again. The cam 12 rotates clockwise against the force of the coil spring 29, and the spring hooked protrusion 12g hits the stopper pin 6e and stops. When the cam 12 rotates clockwise, the cam projection 12a rotates clockwise, and the cam plate 19 rotates counterclockwise about the shaft projection 6g. Cam plate! 9 rotates counterclockwise, one end 27a of the control spring 27 engages the claw portion 12.
At point e, the gear IO meshes with the gear 21, and according to the rotation of the gear IO (that is, the rotation of the shaft 3), the gear 21 rotates against the force of the mainspring spring 14, and the protrusion 21b engages with the gear 1.
Rotate 8 one tooth at a time. However, since the gear 18 stops when its protrusion 18a hits the stopper pin 17b, the seat belt 34 can be pulled out and wound up until the gear 18 makes one rotation. Note that when the gear 18 rotates, the spring 20 prevents its over-rotation and ensures rotation of each tooth of the gear 18. The cam 12 is connected to the other end 27 of the control spring 27.
a, counterclockwise rotation due to the force of the coil spring 29 is prevented, and this state continues as long as the electromagnetic drive means 23 is energized, that is, as long as the buckle switch is turned on. It is. However, if the seat belt 34 is more than a predetermined amount (for example, 1801
1m or more) When pulled out, the protrusion 18a of the gear 18
presses the actuating piece 30 of the limit switch 31, and the actuating piece 3
0 falls and turns off the limit switch 31. When the limit switch 31 h< OFF is operated, it is the same as turning off the buckle switch, and therefore the electromagnetic drive means 23 is de-energized and returns to its original state, that is, the state shown in FIG. The memory is released without removing the tongue from the buckle, and
Memory starts again. That is, the lever 25 rotates counterclockwise around the shaft protrusion 6j by the force of the coil spring 28 to pull out the plunger 24a, and the cam 12' rotates counterclockwise by the force of the coil spring 29 to close the spring hook protrusion. 12g
hits stopper bin 6k and stops. Therefore, the cam plate 19 rotates clockwise via the cam protrusion 12a, and the gears 10 and 21 are disengaged. And gear 21
is rotated in the opposite direction by the force of the built-in mainspring spring 22 and gear 1
The protrusion 18a of No. 8 returns to its original position where it abuts against the stopper pin 17b and stops. In this way, if the seatbelt 34 is pulled out more than a predetermined amount after the seatbelt 34 is fastened, this means that the seatbelt 34 did not fit properly, so the tongue can be set without removing the tongue from the buckle. This is what I did.

[Effects of the Invention] According to the present invention described above, the cam that rotates the cam plate in order to engage and disengage the locking means from the winding shaft is biased to rotate in one direction by a spring, and the cam is biased to rotate in one direction by a spring, and the cam is biased to rotate in one direction by a spring. Since the configuration includes a pair of disengaged pawls, an arcuate inner circumferential portion and a stopper portion that engage a friction clutch that is driven by the rotation of the winding shaft, even if the electromagnetic drive means operates, the winding of the winding shaft is immediately stopped. A player who does not prevent the rotation but temporarily suspends the movement.
Not only does the mechanical configuration become simpler and the number of parts is reduced, leading to lower manufacturing costs, but the degree of freedom in design is greater, and the cam and cam plate can be formed as desired, making the tractor as a whole smaller and more compact. , weight reduction is possible.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view, FIGS. 2 and 3 are partial front and rear views, and FIGS. 4 to 6 are action explanatory views. I... Base frame, 2... Reel, 3... Winding shaft, 5...
...Belt winding mechanism, 5a...Lock mechanism, 6...Base, 8...Coil spring, 9...Friction clutch,! 2・
...Cam, 12a...Cam protrusion, +2b...Arc-shaped inner peripheral part, 12c, 12d...Stopper part, 12e, 12
f...Claw portion, 12g...Spring hook protrusion, 19...Cam plate, 23...Electromagnetic drive means, 25...Control lever, 29...Spring. 2 people Figure 2 Figure 3

Claims (1)

[Claims] A friction clutch that follows the rotation of the seatbelt take-up shaft, a cam that engages with the friction clutch and can rotate within a certain range, and a cam that engages with and disengages from this cam to pull out and take up the seatbelt. a control lever that prevents rotation of the cam and allows rotation of the cam when the seat belt is re-drawn; an electromagnetic drive means that rotates the control lever; A tension lock retractor for a seatbelt, comprising a cam plate having locking means that can be engaged with and detached from a take-up shaft, the cam having a cam protrusion protruding from its surface that engages with the cam plate. In addition, the circumferential side has a spring hooking protrusion of a spring that biases rotation in one direction and a pair of spaced claws with which a part of the control lever engages and disengages, while the back side has a spring hook of a spring that biases rotation in one direction, and a pair of spaced claws that engage and disengage a part of the control lever. A cam mechanism type tension lock retractor for a seatbelt, characterized by having an arcuate inner circumferential portion that partially engages, and stopper portions protruding on both sides of the arcuate inner peripheral portion.