JPH1094620A - Safety belt winding device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle safety belt winding device small in breadthwise dimension at low manufacture cost by stabilizing load in the case of absorbing shock energy, and simplifying its structure. SOLUTION: A webbing winding rod 4 is composed of a bobbin 11 supporting one terminal part of webbing and a shaft 13, which has a latch plate 5, axially supported on a base so as to be freely rotated and axially supported through a hollow part 12 of the bobbin 11 so as to be freely rotated together with the bobbin 11 and between the shaft 13 and the inner surface of hollow part 12 of the bobbin 11, an easily breaking part 14 to be broken only in rotating direction by the rotational force of the bobbin 11 and an engage member 15 for breaking the easily breaking part 14 are interposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a winding device for a safety belt used for vehicles such as automobiles and airplanes, and more particularly to a winding device equipped with an energy absorbing retractor which functions when a large load is applied due to a collision or the like. .

[0002]

2. Description of the Related Art As a conventional vehicle safety belt winding device, there is an example as shown in Japanese Utility Model Laid-Open No. 50-42323.

That is, a conventional vehicle safety belt winding device includes a webbing, a base supported by a vehicle body,
A webbing take-up shaft rotatably supported by the base and winding the webbing, a latch plate fixed to one end of the webbing take-up shaft and having ratchet teeth on the outer periphery, and attached to the base; A pawl that can stop the rotation of the webbing take-up shaft by engaging with the ratchet teeth of the latch plate in an emergency, wherein the webbing take-up shaft has a single or more thread groove on its outer peripheral surface and is continuous with the thread groove. A shaft having an increased portion larger than the width dimension of the thread groove, a sleeve concentric with the shaft and disposed outside the shaft and having several axial grooves on an inner peripheral surface thereof;
The ball has a thread groove increasing portion of the shaft and several balls fitted between the grooves of the sleeve.

[0004] With this configuration, when a force for rotating the sleeve is applied to the webbing by a biasing force of an occupant, such as when a vehicle collides, if the latch teeth of the latch plate are stopped by the pawls, the latching plates move in opposite directions. By the load, the ball is displaced in the axial direction while plastically deforming the thread groove of the shaft and moves in the rotational direction, so that the guide function when rolling the ball and the plastic deformation of the thread groove And a function of absorbing impact energy applied to the webbing.

[0005]

However, according to the energy absorbing means having such a configuration, the screw groove itself having a guiding function when rolling the ball is plastically deformed, so that the position where the load is applied is stable. Will not do.

Further, due to an error in the shape of the thread groove, the load at the time of performing the impact energy absorbing function is not stable, and the accuracy of the shape of the thread groove is required. Therefore, improvement is required.

Further, the structure of the vehicle safety belt winding device is complicated, and there is a problem in productivity. In this respect, it also causes a rise in manufacturing cost, and improvement is required.

Further, the webbing take-up shaft needs to move in the axial direction, so that the width of the vehicle safety belt take-up device itself has to be large, and the layout of the layout is required in a case where the webbing take-up shaft is disposed in a narrow space. When the limiting conditions are severe, improvement is required, for example, in that it is impossible to cope with such a large width dimension.

Therefore, the present invention has been made in view of the above points, and an object thereof is to reduce the cost by stabilizing the load when performing the impact energy absorbing function and by adopting a simple structure. An object of the present invention is to provide a vehicle safety belt winding device having a small width at a low manufacturing cost.

[0010]

According to a first aspect of the present invention, there is provided a webbing, a base supported on a vehicle body, and a web rotatably supported by the base and winding the webbing. A webbing take-up shaft, a latch plate fixed to one end of the webbing take-up shaft and having ratchet teeth on the outer periphery, and a webbing take-up device attached to the base and meshing with the ratchet teeth of the latch plate in an emergency. In a vehicle safety belt winding device having at least a pawl capable of stopping rotation of a shaft, the webbing winding shaft rotates with respect to a hollow bobbin on which one end of the webbing is supported, and the base. A shaft rotatably supported and rotatably supported by the hollow portion of the bobbin and having the latch plate; A breakable portion between the shaft and the inner surface of the hollow portion of the bobbin, the breakable portion being capable of being broken only in the rotational direction by the rotational force of the bobbin; It is characterized in that a joining member is interposed.

According to a second aspect of the present invention, there is provided the vehicle safety belt winding device according to the first aspect, wherein the engaging members are formed on the outer peripheral surface of the shaft and the inner surface of the hollow portion of the bobbin, respectively. And a tongue piece protruding into the concave space from near the bottom surface of the concave portion of the bobbin.

According to a third aspect of the present invention, there is provided the vehicle safety belt winding device according to the second aspect, wherein the concave portion of the shaft is substantially formed on an outer peripheral surface of the shaft from a root of the latch plate to a non-latch plate support portion. The bobbin is formed in a straight line, and the concave portion of the bobbin is formed in a swirl shape on the inner surface of the hollow portion of the bobbin.

According to a fourth aspect of the present invention, in the vehicle safety belt retractor according to the first aspect, the engaging member is slidably engaged in a groove formed in the shaft. And a boss protruding from the slider, and the easy-to-break portion comprises a tongue piece protruding into the concave space from near the bottom surface of the concave portion of the bobbin.

According to a fifth aspect of the present invention, there is provided the vehicle safety belt winding device according to the fourth aspect, wherein the groove portion of the shaft is substantially formed on an outer peripheral surface of the shaft from a root of the latch plate to an anti-latch plate support portion. The bobbin is formed in a straight line, and the concave portion of the bobbin is formed in a swirl shape on the inner surface of the hollow portion of the bobbin.

According to a sixth aspect of the present invention, there is provided the vehicle safety belt winding device according to the first aspect, wherein the engaging member is movably screwed to a threaded portion formed on the shaft. It is characterized in that it is composed of a boss protruding from a nut, and that the easily breakable portion is composed of a tongue piece disposed in a recess of the bobbin.

According to a seventh aspect of the present invention, there is provided the vehicle safety belt winding device according to the sixth aspect, wherein the bobbin has a recess.
It is characterized by being formed substantially linearly.

The invention according to claim 8 is the invention according to claim 6 or claim 7.
The vehicle safety belt winding device according to claim 1, wherein the boss is provided to project from at least four sides of the nut, and the tongue piece is provided to project from at least four sides of the recess. .

The invention of claim 9 is the invention of claim 2 or claim 3.
Or the vehicle safety belt winding device according to claim 5, 7 or 8, wherein the bobbin has a concave portion,
An escape groove is formed so that the tongue can be engaged in the recess of the bobbin.

According to a tenth aspect of the present invention, there is provided the vehicle safety belt winding device according to the first aspect, wherein the engagement member is movably threadedly engaged with a female screw portion formed in a hollow portion of the bobbin. A flange portion protruding from an inner surface of a hollow portion of the hollow bolt, wherein the easily breakable portion is near a bottom surface of a concave portion formed so that the flange portion can be engaged with an outer peripheral surface of the shaft. It is characterized in that it comprises a tongue piece protruding into the recessed space.

According to an eleventh aspect of the present invention, in the vehicle safety belt winding device according to the tenth aspect, the concave portion of the shaft has a shaft outer periphery from a root of the latch plate of the shaft to an anti-latch plate support portion. It is characterized by being formed substantially linearly on the surface.

According to a twelfth aspect of the present invention, there is provided the vehicle safety belt winding device according to the tenth or eleventh aspect, wherein the flange portion is provided so as to project from a position at least facing the inner surface of the hollow bolt. It is characterized by becoming.

[0022]

As is clear from the above, according to the first aspect of the present invention, a large tensile load is applied to the webbing, and the pawl meshes with the ratchet teeth of the latch plate due to the deceleration, so that the webbing take-up shaft of the webbing takes up. When the rotation is stopped, the bobbin of the webbing take-up shaft, which is engaged with the projection of the shaft of the webbing take-up shaft, applies a rotational force to the shaft with the rotational force of the webbing of the bobbin, Since the engaging member breaks the easily breakable portion interposed between the shaft and the bobbin only in the rotation direction, the impact energy, in other words, the pulling force on the webbing is reduced by such a process.

Since the impact energy is absorbed without any intervening members other than the easily breakable portion and the engaging member, the absorption value is stabilized. In addition, with such a simple structure, the webbing winding shaft can be provided at an inexpensive manufacturing cost, and there is no axial displacement of the webbing winding shaft, so that the width of the vehicle safety belt winding device is small.

According to the second aspect of the present invention, in addition to the effect of the first aspect, the engaging member as the engaging member which can move in the concave portions formed on the outer peripheral surface of the shaft and the inner surface of the hollow portion of the bobbin, respectively. When the ball rotates, the tongue piece as the easily breakable portion, which protrudes into the concave space from the vicinity of the bottom surface of the concave portion of the bobbin by rotating the bobbin, is destroyed in the rotation direction. Energy is reliably absorbed.

Further, by simply changing the hardness, material and the like of the tongue piece, the setting of the breaking load by the ball can be easily changed, and the easy change of the load tuning can contribute to safety. Become.

According to the third aspect of the invention, in addition to the effect of the second aspect, the concave portion of the shaft is formed substantially linearly on the outer peripheral surface of the shaft from the base of the latch plate to the anti-latch plate support portion. Therefore, the assembly of the shaft to the bobbin is easy.

Further, since the concave portion of the bobbin is formed in a swirl shape on the inner surface of the hollow portion of the bobbin, the ball can move smoothly when the bobbin rotates, and the tongue piece of the bobbin moves smoothly. Destructible.

According to the fourth aspect of the present invention, in addition to the effect of the first aspect, an engagement protruded from a slider slidably engaged in a groove formed in the shaft. By the boss as a member, the bobbin rotates,
Since the tongue piece as the easy-to-break portion, which protrudes into the concave space from the vicinity of the bottom surface of the concave portion of the bobbin, is broken in the rotation direction, the impact energy is reliably absorbed.

Further, it is possible to easily change the setting of the breaking load by the boss only by changing the hardness, the material, and the like of the tongue piece, and the easy change of the load tuning can contribute to safety. Become.

According to the fifth aspect of the present invention, in addition to the effect of the fourth aspect, the groove portion of the shaft is formed substantially linearly on the outer peripheral surface of the shaft from the base of the latch plate to the anti-latch plate support portion. Therefore, the assembly of the shaft to the bobbin is easy.

Also, since the recess of the bobbin is formed in a swirl shape on the inner surface of the hollow portion of the bobbin, the boss can move smoothly when the bobbin rotates.
The tongue of the bobbin can be smoothly broken.

According to the sixth aspect of the present invention, in addition to the effect of the first aspect, in addition to the above, the engaging member protruded from a nut movably screwed to a threaded portion formed on the shaft is provided. When the bobbin rotates, the tongue piece as the easily breakable portion provided in the recess of the bobbin is broken in the rotation direction, so that the impact energy is reliably absorbed. Is done.

Further, by simply changing the hardness, material, and the like of the tongue piece, the setting of the breaking load by the boss can be easily changed, and the easy change of the load tuning can contribute to safety. Become.

According to the seventh aspect of the present invention, in addition to the effect of the sixth aspect, the concave portion of the bobbin is formed in a substantially linear shape, so that the nut and the shaft can be easily assembled to the bobbin. is there.

According to an eighth aspect of the present invention, in addition to the effect of the sixth or seventh aspect, the boss is protruded from at least four sides of the nut, and the tongue piece is formed at least in the recess. Since it is projected from all sides, when the bobbin rotates, the tongue piece is not easily broken by the boss, and the degree of freedom in selecting the material of the bobbin is increased by that amount, without having to select a high-strength material. The good news is that manufacturing costs can be reduced.

According to the ninth aspect of the present invention, in addition to the effect of the second, third, fifth, seventh, or eighth aspect, the tongue piece is provided in the recess of the bobbin. Since the recessed groove is formed in the recess so that the tongue is bent by the engaging member, the tongue can be easily engaged in the recessed groove.

According to the tenth aspect, in addition to the effect of the first aspect, in addition to the inner surface of the hollow portion of the hollow bolt, the hollow bolt is movably screwed into the female screw portion formed in the hollow portion of the bobbin. The provided flange portion as an engaging member is formed on the shaft outer peripheral surface of the shaft by rotation of the bobbin, whereby the hollow bolt is rotationally moved by the female screw portion, and by rotation of the hollow bolt. Since the tongue piece as an easily breakable portion provided in the concave portion is broken in the rotation direction, the impact energy is reliably absorbed.

Further, by simply changing the hardness, material, and the like of the tongue piece, the setting of the breaking load by the flange portion can be easily changed, and the easy change of the load tuning can contribute to safety. become.

According to the eleventh aspect of the present invention, in addition to the effect of the tenth aspect, the concave portion of the shaft has a substantially linear shape on the outer peripheral surface of the shaft from the root of the latch plate to the anti-latch plate support portion of the shaft. Therefore, the hollow bolt can be easily assembled to the shaft.

According to the twelfth aspect of the present invention, in addition to the effect of the tenth or eleventh aspect, the flange portion is provided so as to protrude from a position at least facing the inner surface of the hollow bolt. When the bobbin is rotated, the tongue can be reliably broken by the hollow bolt rotated by the female screw of the bobbin.

[0041]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 6 are structural views showing the structure of the first embodiment of the present invention.

That is, the vehicle safety belt winding device 1 comprises:
A webbing 2 of the safety belt 2a, a base 3 supported by a vehicle body (not shown), and a webbing winding shaft 4 rotatably supported by the base 3 and winding the webbing 2 thereon
A latch plate 5 fixed to one end 4a of the webbing take-up shaft 4 and having ratchet teeth 5a on its outer periphery;
A magnet 7 attached to the base 3 and in an emergency
Is excited to engage the ratchet teeth 5a of the latch plate 5 to stop the rotation of the webbing take-up shaft 4, and the webbing take-up shaft 4 is always attached to the webbing take-up shaft 4 in the direction in which the webbing 2 is taken up. And a cover member 8 for covering a take-up spring (not shown) that is biased.

The webbing take-up shaft 4 comprises a hollow bobbin 11 having one end of the webbing 2 supported thereon,
A shaft 13 rotatably supported by the base 3 and rotatably supported by the hollow portion 12 of the bobbin 11 together with the bobbin 11 and having the latch plate 5.

Between the shaft 13 and the inner surface of the hollow portion 12 of the bobbin 11, a tongue piece 14 as an easily breakable portion and a ball 15 as an engaging member capable of breaking the tongue piece 14 are interposed. By detecting the tensile load (approximately 1 ton) applied to the webbing 2, the rotation of the shaft 13 is stopped by the pawl 6 engaged with the ratchet teeth 5 a of the latch plate 5. ,
Due to the rotational force generated by the inertia of the bobbin 11 due to the tensile load applied to the webbing 2, the tongue 1
4 can be destroyed only in the direction of rotation.

The ball 15 is movably engaged with a concave portion 16 formed on the outer peripheral surface of the shaft 13 and a concave portion 17 formed on the inner surface of the hollow portion 12 of the bobbin 11. .

The tongue piece 14 protrudes from the vicinity of the bottom surface 17a of the concave portion 17 formed on the inner surface of the hollow portion 12 of the bobbin 11, as shown by a two-dot chain line in FIG. As shown in FIG. 4, a space for accommodating the ball 15 from one end 11a is formed in the recess 1.
7 to the other end 11b.

As shown in FIG. 4, the concave portion 16 of the shaft 13 is formed substantially linearly on the shaft outer peripheral surface 13a from the base of the latch plate 5 to the anti-latch plate support portion. The recess 17 is provided in the bobbin 1.
It is formed in a swirl shape on the inner surface of one hollow portion 12.

The recess 17 of the bobbin 11 is provided with an escape groove 18 in which the tongue 14 can be engaged in the recess 17 of the bobbin 11.

With the configuration of the first embodiment, when a large tensile load (approximately 1 ton) is applied to the webbing 2 of the safety belt 2a, the pawl 6 is moved by the magnet 7 excited by the deceleration, When the pawl 6 meshes with the ratchet teeth 5 a of the latch plate 5, the rotation of the shaft 13 of the webbing winding shaft 4 is stopped.

However, the bobbin 11 of the webbing take-up shaft 4 does not stop immediately, and the bobbin 11 is rotationally urged by the rotational force of the safety belt 2a caused by the tensile inertia of the webbing 2.

The stopped shaft 13 and ball 15
Since the rotational force of the bobbin 11 is transmitted to the bobbin 11 through the recess 17, the ball 15 interposed between the shaft 13 and the bobbin 11 starts rolling in the recesses 16 and 17, and the bobbin 11 From one end 11a to the other end 1
Start moving to 1b.

Therefore, the ball 15 collides with the tongue piece 14 protruding into the space of the concave portion 17, and the tongue piece 14 is sequentially bent and broken into the escape groove 18 from the projecting position only in the rotation direction. In this way, the impact energy, in other words, the pulling force on the webbing 2 is reduced due to this progress, and the impact energy is reliably absorbed.

Since the impact energy is absorbed without any intervening members other than the ball 15 and the tongue piece 17, the absorption value is stabilized. In addition, with such a simple structure, the webbing take-up shaft 4 can be provided at an inexpensive manufacturing cost, and there is no displacement in the axial direction of the webbing take-up shaft 4, so that the width of the vehicle safety belt take-up device 1 is small. Become.

Further, it is possible to easily change the setting of the breaking load by the ball 15 only by changing the hardness, the material, and the like of the tongue piece 14, and the easy change of the load tuning contributes to safety. You can do it.

Since the concave portion 16 of the shaft 13 is formed substantially linearly on the shaft outer peripheral surface 13a from the base of the latch plate 5 to the anti-latch plate support portion, the assembly of the shaft 13 to the bobbin 11 is easy. is there.

The recess 17 of the bobbin 11 is
As shown in FIG. 3, since the bobbin 11 is formed in a swirl shape on the inner surface thereof, the ball 15 can move smoothly when the bobbin 11 rotates, and the tongue piece 14 of the bobbin 11 moves smoothly. Destructible.

The tongue 1 is inserted into the recess 17 of the bobbin 11.
Since the escape groove 4 is formed in the recess 17 of the bobbin 11 so that the tongue 14 can be bent by the ball 15, the escape groove 18 can be easily engaged in the escape groove 18.

As shown in FIG. 7, the tongue piece 14 and the escape groove 18 may be formed on the shaft 13 side.

Further, as shown in FIG.
May be provided not only on one of the tongue pieces 14 (FIGS. 6 and 7), but also on both sides, so that the tongue pieces 14 are not bent but compressed from the distal end 14a to be broken. .

FIG. 9 is a structural diagram showing the configuration of the second embodiment of the present invention.

That is, the vehicle safety belt winding device 1
A webbing 2 of the safety belt 2a, a base 3 supported by a vehicle body (not shown), and a webbing winding shaft 4 rotatably supported by the base 3 and winding the webbing 2 thereon
A latch plate 5 fixed to one end 4a of the webbing take-up shaft 4 and having ratchet teeth 5a on its outer periphery;
A magnet 7 attached to the base 3 and in an emergency
Is excited to be engaged with the ratchet teeth 5a of the latch plate 5 to stop the rotation of the webbing take-up shaft 4, and the pawl 6 is always attached to the webbing take-up shaft 4 in the direction in which the webbing 2 is taken up. As shown in FIGS. 1 to 3, at least a cover member 8 that covers a take-up spring (not shown) that is biased is the same as the configuration of the first embodiment of the present invention.

The webbing take-up shaft 4 is rotatably supported by the bobbin 11 on one end of the webbing 2 and the base 3 so as to be rotatable with respect to the base 3, and is formed together with the bobbin 11 by the hollow portion 12 of the bobbin 11. It comprises a shaft 21 rotatably supported and having the latch plate 5.

A tongue piece 25 as an easily breakable portion and a boss 22 as an engagement member capable of breaking the tongue piece 25 are interposed between the shaft 21 and the inner surface of the hollow portion 12 of the bobbin 11. By detecting a tensile load (approximately 1 ton) applied to the webbing 2, the pawl 6 engaged with the ratchet teeth 5a of the latch plate 5 is detected.
After the rotation of the shaft 21 is stopped, the tongue piece 25 is rotated by the rotational force generated by the coasting force of the bobbin 11 due to the tensile load applied to the webbing 2.
Can be destroyed only in the direction of rotation.

The boss 22 is projected from a slider 24 slidably engaged in a groove 23 formed in the shaft 21.
7 and the tongue piece 25.

The groove 23 of the shaft 21 is formed substantially linearly on the shaft outer peripheral surface 21a from the base of the latch plate 5 to the anti-latch plate support.

With the configuration of the second embodiment, when a large tensile load (approximately 1 ton) is applied to the webbing 2 of the safety belt 2a, the pawl 6 is moved by the magnet 7 excited by the deceleration, When the pawl 6 meshes with the ratchet teeth 5 a of the latch plate 5, the rotation of the shaft 21 of the webbing winding shaft 4 is stopped.

However, the bobbin 11 of the webbing take-up shaft 4 does not stop immediately, and the bobbin 11 is urged to rotate by the rotational force of the safety belt 2a caused by the tensile inertia of the webbing 2.

Since the rotating force of the bobbin 11 is transmitted to the stopped shaft 21 and the boss 22 via the recess 17, the boss 22 interposed between the shaft 21 and the bobbin 11 is The bobbin 11 starts sliding from one end 11a to the other end 11b.

Therefore, the boss 22 hits the tongue piece 25 disposed beside the recess 17 and sequentially folds the tongue piece 25 into the escape groove 18 from the projecting position only in the rotational direction. By doing so, the impact energy, in other words, the pulling force on the webbing 2 is reduced by this progress, and the impact energy is reliably absorbed.

Further, by simply changing the hardness, material, and the like of the tongue piece 25, the setting of the breaking load by the boss 22 can be easily changed. You can do it.

Since the groove portion 23 of the shaft 21 is formed substantially linearly on the shaft outer peripheral surface 21a from the base of the latch plate 5 to the anti-latch plate support portion, the assembly of the shaft 21 to the bobbin 11 is easy. It is.

Further, since the recess 17 of the bobbin 11 is formed in a swirl shape on the inner surface of the hollow portion 12 of the bobbin 11, the boss 22 can move smoothly when the bobbin 11 rotates. The eleven tongue pieces 25 can be broken smoothly.

FIGS. 10 and 11 are structural views showing the configuration of the third embodiment of the present invention.

That is, the vehicle safety belt winding device 1
A webbing 2 of the safety belt 2a, a base 3 supported by a vehicle body (not shown), and a webbing winding shaft 4 rotatably supported by the base 3 and winding the webbing 2 thereon
A latch plate 5 fixed to one end 4a of the webbing take-up shaft 4 and having ratchet teeth 5a on its outer periphery;
A magnet 7 attached to the base 3 and in an emergency
Are excited to be engaged with the ratchet teeth 5a of the latch plate 5 to stop the rotation of the webbing take-up shaft 4, and the pawl 6 is always attached to the webbing take-up shaft 4 in the direction in which the webbing 2 is taken up. As shown in FIGS. 1 to 3, at least a cover member 8 that covers a take-up spring (not shown) that is biased is the same as the configuration of the first embodiment of the present invention.

The webbing take-up shaft 4 is supported by a bobbin 31 on which one end of the webbing 2 is supported, and is rotatably supported on the base 3 together with the bobbin 31 by a hollow portion 32 of the bobbin 31. It comprises a shaft 33 rotatably supported and having the latch plate 5.

Between the shaft 33 and the inner surface of the hollow portion 32 of the bobbin 31, tongue pieces 34, 34 as easily breakable portions are provided.
And bosses 35, 35 as engaging members capable of breaking the tongue pieces 34, 34 are interposed.
The rotation of the shaft 33 is stopped by the pawl 6 engaged with the ratchet teeth 5 a of the latch plate 5 by detecting the tensile load (approximately 1 ton) applied to the webbing 2. The tongue piece 34 can be broken only in the rotation direction by the rotational force generated by the inertia of the bobbin 31 due to the tensile load.

The bosses 35, 35 as the engaging members are
A tongue piece 34, 34 as an easily breakable portion is provided on the bobbin 31 so as to protrude from upper and lower end surfaces of a nut 37 movably screwed to a screw portion 36 formed on the shaft 33. Concave portions 38, 38 formed linearly
It is arranged beside.

The recesses 38, 38 of the bobbin 31 are formed with a relief groove 39 into which the tongues 34, 34 can be engaged.

With the configuration of the third embodiment described above, when a large tensile load (approximately 1 ton) is applied to the webbing 2 of the safety belt 2a, the pawl 6 is moved by the magnet 7 excited by the deceleration, When the pawl 6 meshes with the ratchet teeth 5a of the latch plate 5, the rotation of the shaft 33 of the webbing winding shaft 4 is stopped.

However, the bobbin 31 of the webbing take-up shaft 4 does not stop immediately, and the bobbin 31 is rotationally urged by the rotational force of the safety belt 2a caused by the tensile inertia of the webbing 2.

The shaft 33 and the boss 35 stopped,
35, the rotational force of the bobbin 31 is transmitted through the concave portions 38, 38, so that the shaft 33 and the bobbin 31
The bosses 35, 35 interposed between the
38, the bobbin 31 starts to move from one end 31a to the other end 31b.

Therefore, the bosses 35, 35
The tongues 34, 34, which are arranged beside the 38, collide with the tongues 34 sequentially from the protruding position into the escape groove 39 only from the rotation direction, thereby breaking the tongues. Energy, in other words webbing 2
Is reduced, and the impact energy is reliably absorbed.

Further, only by changing the hardness, material, etc. of the tongue pieces 34, 34, the setting of the breaking load by the bosses 35, 35 can be easily changed, and it is easy to change the load tuning. , Which can contribute to safety.

Since the concave portions 38 of the bobbin 31 are formed substantially linearly from the one end 31a to the other end 31b, the shaft 33 can be easily assembled to the bobbin 31. is there.

As shown in FIG. 12, the boss 35 may be formed so as to protrude from at least four sides of the nut 37.
8 is projected from at least four sides.

In this case, when the bobbin 31 is rotated, it is possible to prevent the boss 35 from easily breaking the tongue piece 34, so that the degree of freedom in selecting the material of the bobbin 31 is increased. Since it is not necessary to select a high-strength material, manufacturing costs can be reduced.

FIG. 13 is a structural diagram showing the configuration of the fourth embodiment of the present invention.

That is, the vehicle safety belt winding device 1
A webbing 2 of the safety belt 2a, a base 3 supported by a vehicle body (not shown), and a webbing winding shaft 4 rotatably supported by the base 3 and winding the webbing 2 thereon
A latch plate 5 fixed to one end 4a of the webbing take-up shaft 4 and having ratchet teeth 5a on its outer periphery;
A magnet 7 attached to the base 3 and in an emergency
Are excited to be engaged with the ratchet teeth 5a of the latch plate 5 to stop the rotation of the webbing take-up shaft 4, and the pawl 6 is always attached to the webbing take-up shaft 4 in the direction in which the webbing 2 is taken up. As shown in FIGS. 1 to 3, at least a cover member 8 for covering an energized take-up spring (not shown) is the same as the configuration of the first embodiment of the present invention.

The webbing take-up shaft 4 includes a bobbin 41 supporting one end of the webbing 2 and a hollow bolt 44 screwed into a female screw 43 formed in a hollow portion 42 of the bobbin 41. It comprises a shaft 45 rotatably supported by the base 3 and having the latch plate 5.

Between the shaft 45 and the inner surface of the hollow portion 42 of the bobbin 41, tongue pieces 46, 46 serving as easily breakable portions are provided.
And a flange portion 47, 47 as an engaging member capable of breaking the tongue pieces 46, 46, interposed therebetween, and by detecting a tensile load (about 1 ton) applied to the webbing 2, the latch Ratchet teeth 5a of plate 5
After the rotation of the shaft 45 is stopped by the pawl 6 engaged with the tongue 6, the tongue pieces 46, 46 are rotated by the rotational force generated by the inertia of the bobbin 41 due to the tensile load applied to the webbing 2. It is possible to break only in the direction of rotation.

The flanges 47, 47 are movably screwed into a female thread 43 formed on the inner surface of the hollow portion 42 of the bobbin 41.
It is provided so as to protrude from a position at least opposite to the inner surface.

The tongue piece 46 extends from the root of the latch plate 5 of the shaft 45 to the anti-latch plate support so that the flanges 47 can be freely engaged with the shaft outer peripheral surface 45a of the shaft 45. It is formed on the outer peripheral surface 45a beside the concave portions 49, 49 formed substantially linearly.

In the concave portions 49, 49 of the shaft 41,
Escape grooves 50, 50 into which the tongues 46, 46 can be engaged
Is formed.

With the configuration of the fourth embodiment described above, when a large tensile load (approximately 1 ton) is applied to the webbing 2 of the safety belt 2a, the pawl 6 is moved by the magnet 7 excited by the deceleration, When the pawl 6 meshes with the ratchet teeth 5a of the latch plate 5, the rotation of the shaft 45 of the webbing winding shaft 4 is stopped.

However, the bobbin 41 of the webbing take-up shaft 4 does not stop immediately, and the bobbin 41 is rotationally urged by the rotational force of the safety belt 2a caused by the tensile inertia of the webbing 2.

The concave portion 49 of the shaft 45 stopped,
49, the rotational force of the bobbin 41 is transmitted via the hollow bolt 44, so that the hollow bolt 44 is
Along 9 and 49, the bobbin 41 starts to slide slightly from one end 41a to the other end 41b.

When the bobbin 41 is rotated, the hollow bolt 44 is rotationally moved by the female screw 43, and the rotation of the hollow bolt 44 causes the shaft 4 to rotate.
5, tongue pieces 46, 46 as easy-to-break portions formed beside concave portions 49, 49 formed on outer peripheral surface 45a of shaft 5
Is destroyed in the rotational direction, so that the impact energy is reliably absorbed.

Further, by simply changing the hardness, material, and the like of the tongue pieces 46, 46, the setting of the breaking load by the flange portions 47, 47 can be easily changed, and the load tuning can be easily changed. Can contribute more to safety.

The recesses 49, 49 of the shaft 45 are formed substantially linearly on the shaft outer peripheral surface 45a from the base of the latch plate 5 to the anti-latch plate support portion of the shaft 45. The hollow bolt 44 can be easily assembled.

Since the flange portions 47, 47 project from at least positions opposing each other from the inner surface 48 of the hollow bolt 44, when the bobbin 41 rotates,
The tongues 46, 46 can be reliably bent and broken sequentially in the escape groove 50 by the hollow bolt 44 rotated by the female screw 43 of the bobbin 41.

[Brief description of the drawings]

FIG. 1 is a top view showing a vehicle safety belt winding device according to a first embodiment of the present invention.

FIG. 2 is a side view taken along the arrow A in FIG.

FIG. 3 is a side view taken along the line BB of FIG. 1;

FIG. 4 is an exploded perspective view of the webbing take-up shaft of FIG. 2;

FIG. 5 is a sectional view taken along the line CC of FIG. 2;

FIG. 6 is an operation explanatory view of FIG. 5;

FIG. 7 is a sectional view corresponding to FIG. 5 according to another example of the first embodiment of the present invention.

FIG. 8 is a sectional view corresponding to FIG. 5 according to yet another example of the first embodiment of the present invention.

FIG. 9 is an exploded perspective view of a webbing winding shaft of the vehicle safety belt winding device according to the second embodiment of the present invention.

FIG. 10 is an exploded perspective view of a webbing winding shaft of a vehicle safety belt winding device according to a third embodiment of the present invention.

FIG. 11 is an explanatory sectional view of FIG. 10;

FIG. 12 shows another example of the third embodiment of the present invention.
FIG.

FIG. 13 is an exploded perspective view of a webbing winding shaft of a vehicle safety belt winding device according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle safety belt winding device 2 Safety belt webbing 3 Base 4 Webbing winding shaft 5 Latch plate 5a Ratchet tooth 6 Stopper 11, 31, 41 Bobbin 12, 32, 42 Hollow portion of bobbin 13, 21, 33, 45 Shafts 14, 25, 34, 46 Tongue piece 15 as an easily breakable part 15 Ball as an engaging member 16, 17, 38, 49 Recessed part 18, 39, 50 Relief groove part 22, 35 Boss as an engaging member 23 Shaft groove part Reference Signs List 24 Slider 36 Screw part of shaft 37 Nut 43 Female screw of hollow part of bobbin 44 Hollow bolt 47 Flange part as engaging member 48 Hollow part of hollow bolt

Claims (12)

[Claims] 1. A webbing, a base supported by a vehicle body, a webbing winding shaft rotatably supported by the base and winding the webbing, and fixed to one end of the webbing winding shaft; A vehicle safety belt winding device having at least a latch plate having ratchet teeth on an outer periphery thereof and a pawl attached to the base and capable of engaging with the ratchet teeth of the latch plate to stop rotation of the webbing winding shaft in an emergency. In the above, the webbing take-up shaft is rotatably supported with respect to the base by a hollow bobbin on which one end of the webbing is supported, and rotatably supported by the hollow portion of the bobbin together with the bobbin. And a shaft having the latch plate, wherein the shaft and the inner surface of the hollow portion of the bobbin are formed. A vehicle safety belt, wherein an easy breakable portion capable of being broken only in the rotational direction by the rotational force of the bobbin and an engaging member capable of breaking the easily breakable portion are interposed. Winding device. 2. The vehicle safety belt take-up device according to claim 1, wherein the engagement member is movable in a recess formed in an outer peripheral surface of the shaft and an inner surface of a hollow portion of the bobbin. A safety belt winding device for a vehicle, wherein the easy-to-break portion comprises a tongue piece protruding into the concave space from near the bottom surface of the concave portion of the bobbin. 3. The vehicle safety belt winding device according to claim 2, wherein the concave portion of the shaft is formed substantially linearly on a shaft outer peripheral surface from a root of the latch plate to an anti-latch plate support portion. The concave portion of the bobbin is formed in a swirl shape on the inner surface of the hollow portion of the bobbin. 4. The vehicle safety belt winding device according to claim 1, wherein the engagement member protrudes from a slider slidably engaged in a groove formed in the shaft. A safety belt winding device for a vehicle, wherein the easy breakable portion comprises a tongue piece protruding into the concave space from near the bottom surface of the concave portion of the bobbin. 5. The vehicle safety belt winding device according to claim 4, wherein the groove portion of the shaft is formed substantially linearly on a shaft outer peripheral surface from a base of the latch plate to a counter latch plate support portion. The concave portion of the bobbin is formed in a swirl shape on the inner surface of the hollow portion of the bobbin. 6. The vehicle safety belt take-up device according to claim 1, wherein the engagement member protrudes from a nut that is movably screwed to a threaded portion formed on the shaft. The vehicle safety belt winding device according to claim 1, wherein the easily breakable portion comprises a tongue piece disposed in a recess of the bobbin. 7. The vehicle safety belt winding device according to claim 6, wherein the recess of the bobbin is formed in a substantially linear shape. 8. The vehicle safety belt take-up device according to claim 6, wherein the boss is provided to project from at least four sides of the nut, and the tongue piece is provided at least in the recess. A safety belt winding device for vehicles, which is protruded from all sides. 9. The vehicle safety belt winding device according to claim 2, wherein the tongue piece is provided in the recess of the bobbin. A safety belt winding device for a vehicle, characterized in that an escape groove portion capable of being engaged is formed in the concave portion. 10. The vehicle safety belt winding device according to claim 1, wherein the engagement member is movably screwed into a female screw portion formed in a hollow portion of the bobbin. A flange portion protruding from an inner surface of the hollow portion, and the easily breakable portion is formed in the concave space from a vicinity of a bottom surface of a concave portion formed so that the flange portion can be engaged with an outer peripheral surface of the shaft. A safety belt winding device for a vehicle, comprising a tongue piece protruding from the vehicle. 11. The vehicle safety belt winding device according to claim 10, wherein the concave portion of the shaft is substantially linear in a shaft outer peripheral surface from a root of the latch plate to an anti-latch plate support portion of the shaft. A safety belt winding device for a vehicle, wherein the winding device is formed on a vehicle. 12. The vehicle safety belt winding device according to claim 10, wherein the flange portion is provided so as to project from a position at least opposite to an inner surface of the hollow bolt. Vehicle safety belt winding device.