WO2019230389A1

WO2019230389A1 - Pretensioner, retractor, and seat belt device

Info

Publication number: WO2019230389A1
Application number: PCT/JP2019/019239
Authority: WO
Inventors: 清史渡邉; 忠之浅子
Original assignee: ＪｏｙｓｏｎＳａｆｅｔｙＳｙｓｔｅｍｓＪａｐａｎ株式会社
Priority date: 2018-05-30
Filing date: 2019-05-15
Publication date: 2019-12-05
Also published as: JP2019206285A; JP7144195B2

Abstract

Provided are a pretensioner, a retractor, and a seat belt device in which a sealing member can be formed from an inexpensive and highly machinable material, and which facilitates cost reduction and ease of machining. A power transmission device 32 includes: a rod-shaped power transmission member 32a that transmits power to a ring gear 31 while being plastically deformed; a pipe-shaped pressure container 32b that guides the power transmission member 32a to the ring gear 31; a sealing member 32c that is disposed behind the power transmission member 32a; a piston 32d that is disposed behind the sealing member 32c; and a gas generator 32e that is disposed at the rear end of the pressure container 32b. The pressure container 32b is provided with a diameter-reduced section 32f formed at the leading end. The sealing member 32c has a diameter D larger than the gap G of the diameter-reduced section 32f, and has a hardness lower than that of the pressure container 32b, and is configured to stop while being plastically deformed in the event of collision with the diameter-reduced section 32f.

Description

Pretensioner, retractor and seat belt device

The present invention relates to a pretensioner, a retractor, and a seat belt device, and more particularly, to a pretensioner, a retractor, and a seat belt device suitable for a configuration including a rod-shaped power transmission member.

2. Description of the Related Art A vehicle such as an automobile is generally provided with a seat belt device that restrains an occupant on a seat that includes a seat portion on which the occupant sits and a backrest portion that is positioned on the back of the occupant. Such a seat belt device includes a webbing that restrains an occupant, a retractor that winds the webbing, a buckle that is disposed on a side surface of the seat, and a tongue that is disposed on the webbing, and the tongue is fitted to the buckle. The passenger is restrained to the seat by webbing. Moreover, it has become common for the retractor to have a pretensioner that removes the slack of the webbing in an emergency such as a vehicle collision (see, for example, Patent Document 1).

In Patent Document 1, an elongate pressure cylinder, an inflator that supplies pressurized fluid into the pressure cylinder, a piston that moves in the pressure cylinder by the pressurized fluid, and a piston that is pushed out of the pressure cylinder by the moving piston. Rod-shaped thrust means, and a pretensioner configured to rotate a gear by the thrust means pushed out from the pressure cylinder is disclosed.

Further, the pressure cylinder has a plastically deformable stopper formed by contracting only one side at a front end portion, the stopper is plastically deformed by colliding the piston against the stopper, and the piston is moved to the pressure cylinder. It is comprised so that it may decelerate by sticking inside.

Special table 2016-523198 gazette

According to the invention described in Patent Document 1 described above, by stopping a piston (hereinafter referred to as “sealing member”) within a pressure cylinder (hereinafter referred to as “pressure container”), the pressure container The release of the pressurized fluid supplied inside can be suppressed. However, in this invention, there is a problem that the hardness of the sealing member needs to be higher than the hardness of the pressure vessel, which causes a cost increase and makes the processing difficult.

The present invention has been devised in view of such problems, and the pretensioner can be configured with a material that is inexpensive and excellent in workability as a sealing member, and can reduce costs and improve workability. An object of the present invention is to provide a retractor and a seat belt device.

According to the present invention, in the pretensioner comprising: a ring gear connected to a spool that winds up a webbing that restrains an occupant; and a power transmission device that transmits power to the ring gear in an emergency, the power transmission device Includes a power transmission member that transmits power to the ring gear, a pipe-shaped pressure vessel that guides the power transmission member to the ring gear, and a sealing member that is disposed behind the power transmission member. The pressure vessel includes a reduced diameter portion formed at a distal end portion, and the sealing member has a diameter larger than a gap of the reduced diameter portion, and is plastically deformed when colliding with the reduced diameter portion. A pretensioner is provided that is configured to stop while.

According to the present invention, in the retractor including a spool that winds up a webbing that restrains an occupant and a pretensioner that winds up the webbing to remove slack in an emergency, the pretensioner is attached to the spool. A ring gear connected to the ring gear, and a power transmission device that transmits power to the ring gear in an emergency, the power transmission device transmitting power to the ring gear; and A pipe-shaped pressure vessel guided to a ring gear; and a sealing member disposed behind the power transmission member, wherein the pressure vessel includes a reduced diameter portion formed at a tip, and the sealing The member has a diameter larger than a gap of the reduced diameter portion, and is configured to stop while plastically deforming when the member collides with the reduced diameter portion. A character is provided.

According to the present invention, in a seat belt device including a webbing that restrains an occupant and a retractor that winds up the webbing, the retractor includes a ring gear connected to the spool, and the ring in an emergency. A power transmission device that transmits power to the gear, the power transmission device transmitting power to the ring gear, and a pipe-shaped pressure vessel that guides the power transmission member to the ring gear; A sealing member disposed behind the power transmission member, and the pressure vessel includes a reduced diameter portion formed at a distal end portion, and the sealing member is more than a gap between the reduced diameter portions. A seatbelt device having a large diameter and configured to stop while plastically deforming when colliding with the reduced diameter portion is provided.

In the above-described pretensioner, retractor, and seat belt device, the reduced diameter portion is a processing portion in which a side surface of the pressure vessel is recessed inward, a metal fitting disposed so as to protrude from the side surface of the pressure vessel, or Further, it may be constituted by any of the cylindrical members inserted into the pressure vessel.

The reduced diameter portion may have a shorter axial length than the sealing member.

The sealing member may have a spherical shape, a cylindrical shape, or a cylindrical shape having a hemispherical surface at one end or both ends. The sealing member may have a through hole or a recess.

The sealing member may have a hardness lower than that of the pressure vessel. Further, the hardness of the sealing member may be a numerical value of 40 to 60% with respect to the hardness of the pressure vessel.

According to the above-described pretensioner, retractor, and seat belt device according to the present invention, the sealing member has a lower hardness than that of the pressure vessel so that the sealing member collides with the reduced diameter portion. Can be stopped by plastic deformation. Therefore, according to the present invention, it is not necessary to make the hardness of the sealing member higher than that of the pressure vessel, and the sealing member can be made of a material that is inexpensive and excellent in workability, which reduces cost and ease of processing. Improvements can be made.

It is a component expanded view which shows the retractor which concerns on one Embodiment of this invention. It is an expanded sectional view which shows the diameter reduction part vicinity of a pressure vessel, (A) is the state at the moment when the sealing member collided with the diameter reduction part, (B) is the state which the sealing member stopped, (C) is a comparison The state which the sealing member of the example stopped is shown. It is a figure which shows the relationship between the load and displacement when a sealing member collides with a reduced diameter part. It is a figure which shows the shape of a reduced diameter part, (A) is a 1st example, (B) is a 2nd example, (C) is a 3rd example, (D) is a 4th example, (E) is a 5th example. , (F) shows a sixth example. It is a figure which shows the shape of a sealing member, (A) is a 1st example, (B) is a 2nd example, (C) is a 3rd example, (D) is a 4th example, (E) is a 5th example. , (F) shows a sixth example, (G) shows a seventh example, (H) shows an eighth example, (I) shows a ninth example, and (J) shows a tenth example. 1 is an overall configuration diagram showing a seat belt device according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. Here, FIG. 1 is an exploded view showing a retractor according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing the vicinity of the reduced diameter portion of the pressure vessel, (A) is a state at the moment when the sealing member collides with the reduced diameter portion, (B) is a state where the sealing member is stopped, C) shows a state in which the sealing member of the comparative example is stopped.

As shown in FIGS. 1 and 2, the retractor 1 according to an embodiment of the present invention includes a spool 2 that winds up a webbing that restrains an occupant, and a pretensioner that winds up the webbing in an emergency to remove slack. The pretensioner 3 includes a ring gear 31 connected to the spool 2 and a power transmission device 32 that transmits power to the ring gear 31 in an emergency. In FIG. 1, webbing is omitted.

The power transmission device 32 includes a rod-shaped power transmission member 32a that transmits power to the ring gear 31 while plastically deforming, a pipe-shaped pressure vessel 32b that guides the power transmission member 32a to the ring gear 31, and a power transmission member 32a. The pressure member 32b includes a sealing member 32c disposed at the rear of the pressure member 32, a piston 32d disposed at the rear of the sealing member 32c, and a gas generator 32e disposed at the rear end of the pressure vessel 32b. The sealing member 32c has a diameter D larger than the gap G of the reduced diameter portion 32f, and stops while being plastically deformed when colliding with the reduced diameter portion 32f. Is configured to do.

The spool 2 is a winding drum that winds up the webbing, and is rotatably accommodated in a base frame 11 that forms the skeleton of the retractor 1. The base frame 11 includes, for example, a first end surface 111 and a second end surface 112 that face each other, and a side surface 113 that connects these end surfaces. The base frame 11 may include a tie plate 114 facing the side surface 113 and connected to the first end surface 111 and the second end surface 112.

Further, for example, the spring unit 4 is disposed on the first end surface 111 side, and the pretensioner 3 and the lock mechanism 5 are disposed on the second end surface 112 side. In addition, arrangement | positioning of the spring unit 4, the pretensioner 3, the lock mechanism 5, etc. is not limited to the structure shown in figure.

Further, an opening 111 a that passes through the shaft portion of the spool 2 is formed on the first end surface 111 of the base frame 11, and a pawl (not shown) of the lock mechanism 5 is formed on the second end surface 112 of the base frame 11. ) And an opening 112a having internal teeth that can be engaged. Further, a part of the pretensioner 3 (for example, the ring gear 31) is disposed inside the second end surface 112 of the base frame 11. The lock mechanism 5 is disposed outside the second end surface 112 of the base frame 11, and the lock mechanism 5 is accommodated in the retainer cover 51.

The vehicle sensor 6 that detects sudden deceleration or inclination of the vehicle body may be disposed on the retainer cover 51. The vehicle sensor 6 includes, for example, a spherical mass body (not shown) and a sensor lever 61 that is swung by the movement of the mass body. The vehicle sensor 6 is fixed by being fitted into an opening 112 b formed in the second end surface 112 of the base frame 11.

The spool 2 may have a hollow at the center, and a torsion bar 21 forming an axis may be inserted therethrough. The torsion bar 21 is connected to the locking base 52 of the locking mechanism 5 whose first end is connected to the end of the spool 2, and the second end is connected to the spring core of the spring unit 4. Therefore, the spool 2 is connected to the spring unit 4 via the locking base 52 and the torsion bar 21, and is urged in the direction of winding the webbing by the spring spring stored in the spring unit 4.

It should be noted that the first end of the torsion bar 21 may be connected to the spool 2 without using the locking base 52. Further, the means for applying the winding force to the spool 2 is not limited to the spring unit 4 and may be other means using an electric motor or the like.

The locking base 52 includes a pawl (not shown) arranged so as to be able to appear and retract from a side surface portion thereof. When the lock mechanism 5 is operated, the pawl is protruded from the side surface portion of the locking base 52 to engage with the internal teeth formed in the opening 112a of the base frame 11, and the rotation of the locking base 52 in the webbing pull-out direction is restricted. To do.

Therefore, even when a load is applied in the webbing pull-out direction in a state where the lock mechanism 5 is activated, the spool 2 can be held in a non-rotating state until a load equal to or greater than a threshold value is generated in the torsion bar 21. it can. And when the load beyond a threshold value arises in the torsion bar 21, when the torsion bar 21 twists, the spool 2 will produce a relative rotational motion and webbing will be pulled out.

Further, the lock mechanism 5 includes a lock gear 53 arranged so as to be adjacent to the locking base 52. The lock gear 53 includes a flywheel (not shown) arranged so as to be swingable. When the webbing is faster than the normal pulling speed, the flywheel swings and is formed on the retainer cover 51. Engage with the inner teeth. Further, when the vehicle sensor 6 is activated, the sensor lever 61 is engaged with an external tooth formed on the side surface of the lock gear 53.

Thus, the rotation of the lock gear 53 is restricted by the operation of the flywheel or the vehicle sensor 6. When the rotation of the lock gear 53 is restricted, relative rotation occurs between the locking base 52 and the lock gear 53, and the pawl protrudes from the side surface portion of the locking base 52 with this relative rotation.

Note that the lock mechanism 5 is not limited to the configuration shown in the figure, and various types of existing configurations can be arbitrarily selected and used. Further, the spool 2 may include an impact absorbing mechanism configured by a combination of a shaft and a wire-shaped or plate-shaped plastic deformation member instead of the torsion bar 21.

The pretensioner 3 includes, for example, a ring gear 31 having engagement teeth on the outer periphery, a power transmission device 32, a pretensioner cover 33 that stores the ring gear 31, and a guide spacer that forms a moving space for the power transmission member 32a. 34, a guide block 35 disposed at a meshing start portion of the ring gear 31 and the power transmission member 32a, and a shaft guide 36 for restricting the radial movement of the ring gear 31.

The pretensioner cover 33, the guide spacer 34, and the shaft guide 36 are disposed inside the second end surface 112 of the base frame 11, and the guide spacer 34 and the shaft guide 36 are accommodated in the pretensioner cover 33. The ring gear 31 is disposed so as to be positioned in a space between the pretensioner cover 33 and the second end surface 112 secured by the guide spacer 34. The ring gear 31 may be referred to as a driving wheel or a rotating member.

The power transmission device 32 is, for example, arranged in the order of a gas generator 32e, a piston 32d, a sealing member 32c, and a power transmission member 32a made of a rod-shaped resin from the rear end to the front end of the pressure vessel 32b having an elongated shape. Has been. The power transmission member 32a, the sealing member 32c, and the piston 32d are accommodated in the pressure vessel 32b and are moved in the pressure vessel 32b by the working gas generated from the gas generator 32e disposed at the rear end of the pressure vessel 32b. To do. The power transmission member 32a is not limited to a resin rod, but may be a ball or a rack that is engaged with the engagement teeth of the ring gear 31 and rotated.

For example, as shown in FIG. 1, the pressure vessel 32 b passes through the upper portion of the first end surface 111, the upper portion of the tie plate 114, and the upper portion of the second end surface 112, and is formed by the second end surface 112 and the side surface 113. It arrange | positions so that it may extend toward the downward direction from the upper part inside a part.

A guide block 35 is disposed at the tip of the pressure vessel 32b. In addition, an opening 32g is formed at the tip of the pressure vessel 32b to discharge the power transmission member 32a guided by the guide block 35 from the pressure vessel 32b to the space formed by the pretensioner cover 33 and the guide spacer 34. Yes.

A reduced diameter portion 32f in which the cross-sectional area of the pressure vessel 32b is partially reduced is formed at the front end portion of the pressure vessel 32b and in front of the opening portion 32g (rear end side). The reduced diameter portion 32f can be formed, for example, by drawing all or a part of the outer periphery of the pressure vessel 32b, or a metal member such as a bolt or rivet or a cylindrical member separate from the pressure vessel 32b is used. It can also be formed.

Here, FIG. 4 is a figure which shows the shape of a reduced diameter part, (A) is a 1st example, (B) is a 2nd example, (C) is a 3rd example, (D) is a 4th example, (E) shows a fifth example, and (F) shows a sixth example. 4A to 4F are longitudinal sectional views (cross-sectional views including the axial direction) of the distal end portion of the pressure vessel 32b.

The first example of the reduced diameter portion 32f shown in FIG. 4A is obtained by drawing the entire outer periphery of the pressure vessel 32b. The second example of the reduced diameter portion 32f shown in FIG. 4B is obtained by drawing only a part of the outer periphery of the pressure vessel 32b.

In the embodiment shown in FIGS. 4 (A) and 4 (B), the reduced diameter portion 32f is formed by forming a processed portion in which the side surface of the pressure vessel 32b is recessed inward. Thus, by processing a part of the pressure vessel 32b to form the reduced diameter portion 32f, an increase in the number of parts and weight can be suppressed. The processing method for forming the reduced diameter portion 32f is not limited to drawing.

A third example of the reduced diameter portion 32f shown in FIG. 4 (C) has a bolt 32h arranged on a part of the outer periphery of the pressure vessel 32b. The number of bolts 32h is arbitrary and is not limited to the number shown. In the fourth example of the reduced diameter portion 32f shown in FIG. 4D, a rivet 32i is arranged on a part of the outer periphery of the pressure vessel 32b. The number of rivets 32i is arbitrary and is not limited to the number shown.

In the embodiment shown in FIGS. 4C and 4D, the reduced diameter portion 32f is formed by arranging a metal fitting so as to protrude from the side surface of the pressure vessel 32b. Thus, the reduced diameter portion 32f can be easily formed by arranging the metal fittings from the side surface to form the reduced diameter portion 32f. The metal fittings that form the reduced diameter portion 32f are not limited to the bolts 32h and the rivets 32i.

In the fifth example of the reduced diameter portion 32f shown in FIG. 4E, a short cylinder-shaped collar 32j is arranged inside the pressure vessel 32b. The cross section of the collar 32j is not necessarily circular, and may be a C-shaped cross section. In the sixth example of the reduced diameter portion 32f shown in FIG. 4F, a long cylindrical pipe 32k is arranged inside the pressure vessel 32b. The cross section of the pipe 32k is not necessarily annular, and may be C-shaped.

In the embodiment shown in FIGS. 4E and 4F, a double tube structure is formed by inserting a cylindrical member into the pressure vessel 32b, and a reduced diameter portion 32f is formed by the stepped portion. It is. In this manner, by inserting the cylindrical member into the reduced diameter portion 32f, the reduced diameter portion 32f can be easily formed while suppressing an increase in the number of parts to a minimum.

The sealing member 32c is a stopper for preventing the working gas supplied to the pressure vessel 32b from being released to the outside when the pretensioner 3 is operated. Specifically, for example, as shown in FIG. 2A, the diameter D of the sealing member 32c is formed larger than the gap G of the reduced diameter portion 32f. Therefore, when the sealing member 32c reaches the reduced diameter portion 32f, the sealing member 32c collides with the reduced diameter portion 32f. The gap G is set to a size that allows the power transmission member 32a to pass therethrough.

Further, the sealing member 32c has a hardness lower than that of the pressure vessel 32b. In general, the pressure vessel 32b is made of a material whose main component is iron. The sealing member 32c is made of, for example, a material mainly composed of aluminum.

If the Vickers hardness of the pressure vessel 32b is HV130, the sealing member 32c is, for example, about HV60 (about 46% of the hardness of the pressure vessel 32b). Note that the hardness of the sealing member 32c is not limited to such a value, and empirically, for example, it may be a value of about 40 to 60% of the hardness of the pressure vessel 32b.

Here, FIG. 5 is a figure which shows the shape of a sealing member, (A) is a 1st example, (B) is a 2nd example, (C) is a 3rd example, (D) is a 4th example, (E) shows the fifth example, (F) shows the sixth example, (G) shows the seventh example, (H) shows the eighth example, (I) shows the ninth example, and (J) shows the tenth example. ing. 5A to 5I are cross-sectional views of the sealing member 32c parallel to the axial direction of the pressure vessel 32b, and FIG. 5J shows the pressure of the sealing member 32c. A cross-sectional view perpendicular to the axial direction of the container 32b is shown.

The first example of the sealing member 32c shown in FIG. 5A is obtained by forming the sealing member 32c into a spherical shape. In the second example of the sealing member 32c shown in FIG. 5B, the sealing member 32c is formed in a cylindrical shape having hemispherical surfaces at both ends. In the third example of the sealing member 32c shown in FIG. 5C, the sealing member 32c is formed in a cylindrical shape. In a fourth example of the sealing member 32c shown in FIG. 5D, the sealing member 32c is formed in a cylindrical shape having a hemispherical surface at one end.

A fifth example of the sealing member 32c shown in FIG. 5 (E) is obtained by forming an axial through hole 32m of the pressure vessel 32b in the sealing member 32c of the second example shown in FIG. 5 (B). is there. Further, the sixth example of the sealing member 32c shown in FIG. 5 (F) is obtained by forming the concave portion 32n in the axial direction of the pressure vessel 32b on the sealing member 32c of the second example shown in FIG. 5 (B). It is. Thus, by forming the axial through hole 32m or the recess 32n, the plastic deformation amount or the plastic deformation shape of the sealing member 32c can be controlled. The number of through holes 32m or recesses 32n is arbitrary, and both the through holes 32m and the recesses 32n may be formed.

In the seventh example of the sealing member 32c shown in FIG. 5G, the through-hole 32p in the radial direction of the pressure vessel 32b is formed in the sealing member 32c of the second example shown in FIG. is there. Further, the eighth example of the sealing member 32c shown in FIG. 5 (H) is obtained by forming the radial concave portion 32q of the pressure vessel 32b on the sealing member 32c of the second example shown in FIG. 5 (B). It is. Thus, the plastic deformation amount or the plastic deformation shape of the sealing member 32c can also be controlled by forming the radial through hole 32p or the recess 32q. The number of through holes 32p or recesses 32q is arbitrary, and both the through holes 32p and the recesses 32q may be formed.

A ninth example of the sealing member 32c shown in FIG. 5 (I) has an annular recess 32r formed on the outer periphery of the sealing member 32c of the second example shown in FIG. 5 (B). In the tenth example of the sealing member 32c shown in FIG. 5J, the axial recess 32s of the pressure vessel 32b is formed on the surface of the sealing member 32c of the second example shown in FIG. It is a thing. Thus, by forming the

recesses

32r and 32s on the surface of the sealing member 32c, the plastic deformation amount or the plastic deformation shape of the sealing member 32c can be controlled. The number of the

recesses

32r and 32s is arbitrary, and both the

recesses

32r and 32s may be formed.

Since the sealing member 32c described above is accommodated in the pressure vessel 32b, the diameter D of the sealing member 32c is formed smaller than the inner diameter of the pressure vessel 32b. Therefore, a slight gap is formed between the sealing member 32c and the inner surface of the pressure vessel 32b. When the working gas is generated from the gas generator 32e, the working gas may be discharged to the outside from the tip of the pressure vessel 32b through this gap.

Therefore, in the present embodiment, a piston 32d made of an elastic material is disposed behind the sealing member 32c. By disposing the piston 32d, as shown in FIG. 2A, the piston 32d can be pressed against the sealing member 32c by the pressure of the working gas, and the sealing member 32c and the pressure vessel are elastically deformed. The gap with the inner surface of 32b can be sealed.

Since the sealing member 32c that has collided with the reduced diameter portion 32f is formed of a material having a hardness lower than that of the pressure vessel 32b, for example, it is plastically deformed as shown in FIG. The vehicle decelerates while sinking into 32f, and finally stops without passing through the reduced diameter portion 32f.

The axial length L of the reduced diameter portion 32f may be formed shorter than the diameter D of the sealing member 32c, as shown in FIG. The axial length L of the reduced diameter portion 32f depends on conditions such as the amount of protrusion of the reduced diameter portion 32f, the amount of plastic deformation of the sealing member 32c, and the amount of kinetic energy when the sealing member 32c collides with the reduced diameter portion 32f. The sealing member 32c is set so as not to pass through the reduced diameter portion 32f.

The comparative example shown in FIG. 2C shows the behavior when the sealing member 32c ′ has a higher hardness than the pressure vessel 32b ′. In this case, as illustrated, the pressure vessel 32b 'side is deformed, and the sealing member 32c' stops at the reduced diameter portion 32f '.

Here, FIG. 3 is a diagram showing the relationship between the load and the displacement when the sealing member collides with the reduced diameter portion. Specifically, the sealing

members

32c and 32c ′ are in contact with the reduced

diameter portions

32f and 32f ′, a load is applied to the sealing

members

32c and 32c ′ by a pressing jig, and the displacement is measured. is there. The horizontal axis represents displacement (mm), and the vertical axis represents load (kN). Moreover, the test result of the sealing member 32c according to the present embodiment is indicated by a solid line, and the test result of the sealing member 32c ′ of the comparative example is indicated by a dotted line.

As shown in the drawing, the load maximum point Ms of the present embodiment using the soft sealing member 32c is higher than the load maximum point Mh of the comparative example using the hard sealing member 32c ′. It can be seen that the displacement until reaching the maximum load reaching point Ms is also small. Therefore, according to the sealing member 32c having a low hardness according to the present embodiment, after colliding with the reduced diameter portion 32f, the load reaching point Ms can be quickly reached and the reduced diameter portion 32f can be efficiently sealed. .

Here, the operation of the pretensioner 3 will be described. In the normal state before the operation of the pretensioner 3, the state where the power transmission member 32a is accommodated in the pressure vessel 32b is maintained. In an emergency such as a vehicle collision (when the pretensioner 3 is activated), the piston 32d, the sealing member 32c, and the power transmission member 32a are pushed out by the working gas supplied by the gas generator 32e, and the pressure vessel Move in 32b.

The power transmission member 32a pushed out in the pressure vessel 32b moves along the guide block 35 and collides with the engaging teeth of the ring gear 31. Thereafter, the power transmission member 32a is pushed into a space (passage) formed by the pretensioner cover 33 and the guide spacer 34, and moves along the passage while being plastically deformed and engaged with the engagement teeth of the ring gear 31. .

The power transmission member 32a finally stops when it collides with the end of the passage formed by the guide spacer 34 or finishes winding up the webbing slack.

Here, in the present embodiment, as shown in FIG. 2A, after the sealing member 32c collides with the reduced diameter portion 32f, the sealing member 32c is changed as shown in FIG. The piston 32d is held in the pressure vessel 32b by being plastically deformed and stopped at the reduced diameter portion 32f.

According to the pretensioner 3 according to the above-described embodiment, the hardness of the sealing member 32c is lower than the hardness of the pressure vessel 32b, so that when the sealing member 32c collides with the reduced diameter portion 32f, the sealing member 32c can be plastically deformed and stopped. Therefore, according to the present embodiment, it is not necessary to make the hardness of the sealing member 32c higher than that of the pressure vessel 32b, and the sealing member 32c can be made of a material that is inexpensive and excellent in workability, thereby reducing costs and The processability can be improved.

In the above-described embodiment, the case where the pretensioner 3 includes the guide block 35 has been described. However, the pretensioner 3 according to the present embodiment is also applicable to a conventional pretensioner that does not include the guide block 35. Can do.

Next, a seat belt device according to an embodiment of the present invention will be described with reference to FIG. Here, FIG. 6 is an overall configuration diagram showing the seat belt device according to the embodiment of the present invention. In FIG. 6, for convenience of explanation, components other than the seat belt device are indicated by a one-dot chain line.

A seat belt device 100 according to the present embodiment shown in FIG. 6 includes a webbing W that restrains an occupant, a retractor 1 that winds the webbing W, a guide anchor 101 that is provided on the vehicle body side and guides the webbing W, The retractor 1 includes, for example, the configuration shown in FIG. 1. The retractor 1 includes a belt anchor 102 that fixes the webbing W to the vehicle body side, a buckle 103 disposed on the side surface of the seat S, and a tongue 104 disposed on the webbing W. have.

Hereinafter, components other than the retractor 1 will be briefly described. The seat S includes, for example, a seat portion S1 on which an occupant sits, a backrest portion S2 located on the back of the occupant, and a headrest portion S3 that supports the occupant's head. The retractor 1 is built in, for example, the B pillar P of the vehicle body. In general, the buckle 103 is often disposed on the side surface of the seat portion S1, and the belt anchor 102 is often disposed on the lower surface of the seat portion S1. Further, the guide anchor 101 is often disposed on the B pillar P. The webbing W has one end connected to the belt anchor 102 and the other end connected to the retractor 1 via the guide anchor 101.

Therefore, when the tongue 104 is fitted to the buckle 103, the webbing W is pulled out from the retractor 1 while sliding through the insertion hole of the guide anchor 101. Further, when the occupant wears the seat belt or releases the seat belt when getting off the vehicle, the webbing W is wound up to a certain load by the action of the spring unit 4 of the retractor 1.

The above-described seat belt device 100 is obtained by applying the retractor 1 according to the above-described embodiment to a normal seat belt device in a front seat. Therefore, according to the seatbelt device 100 according to the present embodiment, it is not necessary to make the sealing member 32c harder than the pressure vessel 32b, and the sealing member 32c is made of a material that is inexpensive and excellent in workability. Thus, cost reduction and processability can be improved.

Note that the seat belt device 100 according to the present embodiment is not limited to the application to the front seat, and can be easily applied to the rear seat, for example, by omitting the guide anchor 101. Moreover, the seatbelt apparatus 100 which concerns on this embodiment can be used also for vehicles other than a vehicle.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

Reference Signs List 1 retractor 2 spool 3 pretensioner 4 spring unit 5 lock mechanism 6 vehicle sensor 11 base frame 21 torsion bar 31 ring gear 32 power transmission device 32a power transmission member

32b pressure vessel

32c sealing member 32d piston

32e gas generator 32f reduced diameter portion 32g Opening 32h Bolt 32i Rivet 32j Collar 32k Pipe 32m Through hole 32n Recess 32p Through

hole

32q, 32r, 32s Recess 33 Pretensioner cover 34 Guide spacer 35 Guide block 36 Shaft guide 51 Retainer cover 52 Locking base 53 Lock gear 61 Sensor lever DESCRIPTION OF SYMBOLS 100 Seat belt apparatus 101 Guide anchor 102 Belt anchor 103 Buckle 104 Tongue 111 1st end surface 111a Opening part 112 2nd end surface 12a, 112b opening 113 side 114 tie

Claims

In a pretensioner including a ring gear connected to a spool that winds up a webbing that restrains an occupant, and a power transmission device that transmits power to the ring gear in an emergency,
The power transmission device includes a power transmission member that transmits power to the ring gear, a pipe-shaped pressure vessel that guides the power transmission member to the ring gear, and a sealing member that is disposed behind the power transmission member And including
The pressure vessel includes a reduced diameter portion formed at a distal end portion,
The sealing member has a diameter larger than the gap of the reduced diameter portion, and is configured to stop while plastically deforming when colliding with the reduced diameter portion.
Pretensioner characterized by that.
The reduced diameter portion is a processing portion in which a side surface of the pressure vessel is recessed inward, a metal fitting disposed so as to protrude from the side surface of the pressure vessel, or a cylindrical member inserted into the pressure vessel. The pretensioner according to claim 1, wherein the pretensioner is configured by any of the above.
The pretensioner according to claim 1, wherein the reduced diameter portion has an axial length shorter than that of the sealing member.
The pretensioner according to claim 1, wherein the sealing member has a spherical shape, a cylindrical shape, or a cylindrical shape having a hemispherical surface at one end or both ends.
The pretensioner according to claim 4, wherein the sealing member has a through hole or a recess.
The pretensioner according to claim 1, wherein the sealing member has a hardness lower than that of the pressure vessel.
The pretensioner according to claim 6, wherein the hardness of the sealing member is a value of 40 to 60% with respect to the hardness of the pressure vessel.
In a retractor including a spool that winds up a webbing that restrains an occupant and a pretensioner that winds up the webbing to remove slack in an emergency,
The retractor according to any one of claims 1 to 7, wherein the pretensioner is the pretensioner according to any one of claims 1 to 7.
In a seat belt device including a webbing that restrains an occupant and a retractor that winds the webbing,
A seatbelt device, wherein the retractor includes the pretensioner according to any one of claims 1 to 7.