JPH11115684A - Throwback prevention device and webbing tension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a throwback prevention device and a webbing tension device, which are small in size, and are hardly thrown back. SOLUTION: If a pulley 22 intends to go backward to the direction indicated by an arrow head, since a tapered surface 68 formed in the housing recessed part 66 of the pulley 22 presses a roller 58 onto a base plate 12, a space between the tapered surface 68 and the roller 58, and a space between the base plate 12 and the roller 58 are subjected to friction force, and the friction force is turned out the resistance of rotation to the webbing unwinding direction of the pulley 22. The roller 58 is engaged with each trough part 62, since it is subjected to the pushing back force of an oblique surface formed from the trough part 62 up to a crest part 64, the aforesaid friction force is thereby magnified. Besides, the tip end of the pawl piece 60 of a guide plate 54 is hitched over the trough part 62 of the base plate 12. By this constitution, the throwback of the pulley 22 is made little. Since there is no need for providing a separate member in the outer side area of the pulley 22, a throwback prevention device and a webbing tension device can be made small in size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reversing prevention device and a webbing tensioning device, for example, a webbing tensioning device for preventing a webbing from being loosened under a certain condition, and a reversion preventing device used in the webbing tensioning device. .

[0002]

2. Description of the Related Art In a vehicle seat belt device, a member to be wound such as a wire is extended from a buckle provided at an intermediate portion of a webbing, and the member to be wound is fixed under a certain condition such as when the vehicle suddenly decelerates. Is provided with a pretensioner (webbing tensioning device) of a type that tensions webbing by winding the webbing. In this type of pretensioner, a rewind preventing device is used to prevent rewind of the wound wire (Japanese Patent Application Laid-Open No. 9-303471).

As shown in FIG. 11, in this pretensioner 110, a plurality of gear teeth 116 constituting a reverse rotation preventing device are formed on the outer periphery of a pulley 114 on which a wire 112 is wound. On the other hand, a pawl 120, which also constitutes a reverse prevention device, is pivotally supported on the base plate 118 on which the pulley 114 is pivotally supported, and the teeth 122 formed on the pawl 120 can engage with the gear teeth 116. I have.

When the pulley 114 rotates in the winding direction of the wire 112 (clockwise direction in FIG. 11, direction of arrow C), one end 124A of the spring 124 is disengaged by the gear teeth 116 (counterclockwise in FIG. 11). (Circumferential direction).
As a result, the pawl 120 rotates in the disengagement direction (counterclockwise direction in FIG. 11, arrow D direction), so that the teeth 122
Do not engage the gear teeth 116. On the other hand, as shown in FIG. 12, when the pulley 114 tries to rotate in the pulling direction of the wire 112 (counterclockwise direction, the direction opposite to the arrow C), one end 124A of the spring 124 is moved by the gear teeth 116. It is pushed in the engagement direction (clockwise direction in FIG. 12). As a result, the pawl 120 rotates in the engaging direction (the clockwise direction in FIG. 12, the direction of the arrow E), so that the teeth 122 engage with the gear teeth 116. As a result, the rotation of the pulley 114 in the wire pull-out direction is prevented.

However, in this pretensioner 110,
Since the pawl 120 is attached to a position on the radially outer side of the pulley 114 to constitute the reverse return preventing device, the reverse return preventing device becomes large. In particular, when the teeth 122 are formed in a large size in order to reduce the reverse movement (specifically, the reverse rotation of the pulley 114) due to, for example, a delay in engagement, the pawl 12
0 also becomes large, and the whole anti-return device becomes larger.

[0006] Such a problem occurs not only when the reversing prevention device is applied to a pretensioner but also when applied to any device.

[0007]

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a reversing prevention device and a webbing tensioning device which are small in size and have little reversion.

[0008]

According to the first aspect of the present invention, the moving means to which the moving member is fixed, the supporting means for movably supporting the moving means, and the moving means under a certain condition. A driving unit for moving the supporting unit in a predetermined direction, an intermediate member disposed between the moving unit and the supporting unit, provided on one of the moving unit and the supporting unit, When the moving unit attempts to return to the supporting unit in a direction opposite to the moving direction of the driving unit, a pressing unit that presses the intermediate member toward one of the moving unit and the supporting unit, and the moving unit. A movement preventing means provided on one of the other of the supporting means and preventing movement of the intermediate member pressed by the pressing means.

Under certain conditions, the driving means moves the moving means in a predetermined direction with respect to the supporting means, so that the moving member fixed to the moving means also moves in the predetermined direction.

When the moving means tries to move (return) with respect to the supporting means in the direction opposite to the moving direction,
A pressing means provided on one of the moving means and the supporting means presses the intermediate member toward the other of the moving means and the supporting means. Due to this reaction force, the intermediate member is pressed toward both the support means and the moving means, and the friction between the support means and the intermediate member and between the moving means and the intermediate member increases. For this reason, the friction between the supporting means and the moving means also increases, and the movement of the moving means becomes a resistance.

Further, the intermediate member pressed against one of the moving means and the supporting means by the pressing means is prevented from moving by the movement preventing means. For this reason, the intermediate member does not move with respect to the moving means or the supporting means. That is, the return of the moving means to the supporting means is reduced.

[0012] The intermediate member is disposed between the moving means and the supporting means, and is not provided at a position outside the moving means or the supporting means. For this reason, the reverse movement prevention device can be downsized.

According to a second aspect of the present invention, in the first aspect of the present invention, the movement preventing means engages with the intermediate member pressed against moving means or supporting means by the pressing means. It is characterized by being.

That is, it is possible to constitute the movement preventing means with a simple structure in which the engaging concave portion with which the intermediate member is engaged is provided in either the moving means or the supporting means, and to prevent the movement of the intermediate member. it can.

According to the third aspect of the present invention, a pulley to which a wire extending from a buckle attached to the seat belt webbing is fixed, a base plate for rotatably supporting the pulley, and the vehicle being rapidly decelerated. Rotating means for rotating a pulley in the winding direction of the wire, a roller housed in a housing recess formed on a surface of the pulley facing the base plate, wherein the pulley has an axial direction, and a housing recess. And a tapered surface that presses the roller toward the base plate when the pulley tries to rotate in the wire pull-out direction, and engages with the roller formed on the base plate and pressed by the tapered surface. And an engaging portion for preventing movement of the roller.

When the vehicle is rapidly decelerating, the rotating means rotates the pulley in the winding direction of the wire, so that the wire is wound on the pulley. Thereby, the buckle approaches the webbing tensioning device, and the webbing is tensioned.

Depending on the cause of the wire being pulled,
As the pulley attempts to rotate in the direction of wire withdrawal, the tapered surface pushes the rollers toward the base plate. With this reaction force, the roller is pressed toward the tapered surface. As a result, the friction between the base plate and the roller and between the tapered surface and the roller increases, so that the friction between the pulley and the base plate also increases, resulting in resistance to the rotation of the pulley.

Further, the roller pressed against the base plate by the tapered surface engages with the engaging portion and is prevented from moving. For this reason, the roller does not move with respect to the pulley or the base plate, and the return of the pulley is reduced.

The roller is housed in a housing recess formed on the surface of the pulley facing the base plate, and is not disposed outside the pulley. For this reason, the webbing tensioning device can be downsized.

According to a fourth aspect of the present invention, in the third aspect of the invention, the engaging portion is a valley formed by partially recessing a surface of the base plate facing the pulley. It is characterized by the following.

That is, the engaging portion is formed by a simple structure in which the valley portion with which the roller is engaged is formed by partially recessing the surface of the base plate facing the pulley, and the movement of the roller is prevented. Can be.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a webbing tensioning device 10 using a reverse rotation preventing device according to an embodiment of the present invention.

The webbing tensioning device 10 has a metal base plate 12 fixed to or near a vehicle seat cushion (not shown). The base plate 12 includes a substantially disk-shaped support part 14 and a substantially rectangular parallelepiped mounting part 16 formed integrally with the support part 14. Further, as described later, the support portion 14 has
A substantially conical storage portion 18 for storing the wire 32 unwound from the pulley 22 is formed.

As shown in FIG. 5, from the center of the support portion 14, a shaft 20 whose normal direction (the vertical direction in FIG. 5) of the support portion 14 is set to be the axial direction. Shaft 2
0 is the center hole 22A of the pulley 22 (see FIGS. 3 and 4)
, Whereby the pulley 22 is rotatably supported by the shaft 20.

A pulley cover 24 is mounted on the support portion 14, and the pulley cover 24
Are shielded from the outside. A bolt 26 is screwed into the tip of the shaft 20, and the head of the bolt 26 contacts the pulley cover 24, thereby preventing the pulley 22 and the pulley cover 24 from coming off.

The pulley 22 includes a large-diameter winding portion 28 formed at a portion near the support portion 14 and a small-diameter winding portion 30 formed at a portion distant from the support portion 14. The wire 32 is wound around the large diameter winding section 28 and the small diameter winding section 30 in order.

As shown in FIG. 1 and FIG.
In FIG. 2, a gently bent curved portion 34 is formed. The position of the curved portion 34 is shifted toward the one end 32A side from the longitudinal center of the wire 32, and the other end 32B side of the wire 32 is longer than the one end 32A side.

A hook 3 of a buckle 36 attached to a webbing (not shown) is attached to the curved portion 34 of the wire 32.
8 is hooked. Thereby, the wire 32
Is connected to the hook 38 and cannot be removed.

Between the buckle 36 and the support portion 14, a bellows-like wire cover 40 which is substantially cylindrical and partially expandable and contractable is provided.
Is attached. The portion of the wire 32 from the buckle 36 to the webbing tensioning device 10 is shielded from the outside by the wire cover 40, and the appearance is improved. Further, as shown in FIG. 2, the pulley 22 rotates in the wire winding direction (clockwise direction in FIG. 2, arrow A direction) to wind the wire 32 around the pulley 22, and the buckle 36 faces the webbing tensioning device 10. When approaching, the buckle 36 pushes the bellows portion of the wire cover 40 to bend and overlap, and the wire cover 40 as a whole shrinks.

As shown in FIGS. 1 and 2, a wire aligning plate 42 is fixed in the receiving portion 18 of the base plate 12 as wire aligning means. As shown in FIG. 6, the wire alignment plate 42 is formed in a substantially flat conical shape, and has two insertion holes 44 along the same direction as the center line.
Are formed. Each of the insertion holes 44 is
The diameter is the same as or slightly larger than that of the shaft 20 and two are formed adjacent to each other in the longitudinal direction of the shaft 20 (the direction perpendicular to the slope in FIGS. 1 and 2 and the horizontal direction in FIG. 6). Therefore, the wire 32 in which the bending portion 34 is hooked on the hook 38,
The portion on one end 32A side and the portion on the other end 32B side are inserted into the insertion hole 44 while approaching each other. And
The portion on the one end 32A side and the portion on the other end 32B side of the wire 32 are always aligned in the axial direction of the shaft 20.

The wire 32 is thus connected to the shaft 2.
While maintaining the state aligned in the 0 axis direction, pulley 2
The second large-diameter winding section 28 is wound around the second large-diameter winding section 28. Wire 32
Is shorter than the other end 32B side.
2A is fixed to the fixing portion 46 formed on the pulley 22. The portion of the wire 32 on the other end 32B side is further wound around the small-diameter winding portion 30 of the pulley 22, and its tip (one end 32A). Is fixed to the piston 48.

The piston 48 is connected to the base plate 12
Of the pulley 22 in the cylinder 50 in a normal state.
Located closest to When a state in which the deceleration of the vehicle exceeds a predetermined value (vehicle rapid deceleration state) is detected by a sensor (not shown) mounted on the mounting portion 16, the gas generator 52 mounted on the mounting portion 16 operates. Then, as shown in FIG.
To the rear wall 50A.

As a result, the pulley 22 rotates in the wire winding direction (clockwise direction in FIGS. 1 and 2, arrow A direction),
A portion of the wire 32 from the pulley 22 to the hook 38 is gradually wound up by the large-diameter winding portion 28 of the pulley 22.

As shown in detail in FIGS. 3, 4 and 7 to 10, a guide plate 54 is arranged between the base plate 12 and the pulley 22. The guide plate 54 is formed in a substantially semi-annular shape, and
Base plate 12 so that it can rotate coaxially with
It is supported by.

At a plurality of (four in the present embodiment) positions at predetermined intervals in the circumferential direction, the plate material constituting the guide plate 54 is partially cut, and the guide plate 54 is cut. Are raised toward the pulley 22 to form a pair of holding plate pairs 5.
6 are formed. A roller 58 is arranged between the pair of holding plates 56.

The roller 58 is formed in a substantially cylindrical shape, and the center axis direction of the roller 58 matches the radial direction of the guide plate 54. The outer peripheral surface of the roller 58 faces the inner surface of the holding plate pair 56 with a slight gap. Thus, the roller 58 is held so as not to be inadvertently moved in the circumferential direction with respect to the guide plate 54. Therefore, when the guide plate 54 rotates relative to the base plate 12, the roller 58 rotates on the surface of the base plate 12 while maintaining the position relative to the guide plate 54 at a constant position.

The outer peripheral surface of the roller 58 is knurled, and a plurality of knurls whose longitudinal direction is the axial direction of the roller 58 are formed at predetermined intervals in the circumferential direction. The frictional force between the roller 58 and the base plate 12 or a tapered surface 68 described later is increased by the knurls.

At a position between the plurality of holding plate pairs 56 in the guide plate 54, the plate material constituting the guide plate 54 is cut in a substantially U-shape, and the cut inner portion is directed in the wire drawing direction ( It is a cantilevered claw piece 60 extending toward the direction of arrow B in FIGS. 7 to 10). Further, the tip of the claw piece 60 is bent toward the base plate 12 at an obtuse angle to form an engagement piece 60A.

On the other hand, on the surface of the base plate 12 facing the guide plate 54, a waveform is formed in which valleys 62 and ridges 64 are alternately continuous along the circumferential direction. Thereby, when the guide plate 54 tries to rotate in the wire winding direction (the direction of arrow A in FIGS. 1 and 2, the direction opposite to the arrow B in FIGS. 7 to 10) with respect to the base plate 12. As can be seen from FIG. 8, the engagement piece 60A is pushed up toward the pulley 22 by the peak portion 64 and is bent, so that this rotation is not prevented. On the other hand, when the guide plate 54 tries to rotate with respect to the base plate 12 in the wire drawing direction (the direction of the arrow B), as shown in FIGS. This rotation is prevented because the hook is caught by the valley 62.

A receiving recess 56 is formed on the surface of the pulley 22 facing the guide plate 54. Housing recess 5
Reference numeral 6 is formed at a position corresponding to the roller 58, and accommodates the roller 58 and the holding plate pair 56. Further, as shown in FIGS. 7 to 10, a tapered surface 68 is formed in the housing recess 56 so as to gradually separate from the base plate 12 in the wire drawing direction (the direction of the arrow B), and is formed substantially in a wedge shape as a whole. I have. Therefore, as shown in FIG. 10, when the pulley 22 attempts to rotate in the wire pull-out direction with respect to the base plate 12, the taper surface 68 pushes the roller 58, so that the roller 58
Pressed on 2. For this reason, the pulley 22 and the roller 5
8 and base plate 12 and rollers 58
And the friction between the pulley 22 and the pulley 22 is increased.

The waveform shape of the base plate 12 is as follows:
The shape is determined in advance so that the roller 58 pressed against the base plate 12 enters the valley 62 in this manner. As a result, the roller 58 pressed against the base plate 12 engages with the valley 62,
When the roller 58 tries to move, the roller 58 receives a reaction force from the slope toward the peak 64 and approaches the tapered surface 68 along the slope, and further strongly contacts the tapered surface 68 and the base plate 1.
Pressed on 2. Therefore, the movement of the roller 58 is prevented, and the rotation of the pulley 22 is also prevented.

On the other hand, when the pulley 22 rotates in the wire winding direction with respect to the base plate 12, the taper surface 68 is separated from the roller 58, so that the roller 58 is not pushed toward the taper surface 68 and the base plate 12. . Since no friction occurs between the tapered surface 68 and the roller 58 and between the base plate 12 and the roller 58, the pulley 22 can rotate without receiving any resistance.

Next, the operation of the webbing tensioning device 10 using the reverse rotation preventing device according to the present embodiment will be described.

As shown in FIG. 1, in a normal state, the gas generator 52 is not operating, and the piston 48 is located in the cylinder 50 at a position closest to the pulley 22. The wire 32 extends from the large-diameter winding portion 28 of the pulley 22 by a predetermined length, and the buckle 36 is not drawn toward the webbing tensioning device 10. For this reason, the webbing is mounted on the occupant with a predetermined appropriate tension.

When the vehicle is rapidly decelerated and a deceleration equal to or more than a predetermined value is detected by a sensor (not shown), the gas generator 52 operates and the piston 48 is moved to the inner wall 50A of the cylinder 50 as shown in FIG. Move towards.
Thereby, one end of the wire 32 is pulled into the cylinder 50, and the pulley 22 is urged to rotate in the wire winding direction (clockwise direction in FIG. 2, arrow A direction).

Here, as shown in FIG. 8, when the pulley 22 tries to rotate with respect to the base plate 12 in the wire winding direction (the direction opposite to the arrow B), the taper formed in the accommodation recess 66 of the pulley 22 is increased. Surface 68 moves away from roller 58. Since the space between the tapered surface 68 and the roller 58 and the space between the base plate 12 and the roller 58 are separated and no friction occurs, the pulley 22 can rotate in the wire winding direction.

As the pulley 22 rotates in the wire winding direction, one of the holding plate pairs 56 is pressed against the side surface of the housing recess 66, so that the guide plate 54 is also moved in the wire winding direction (opposite to the arrow B in FIG. 8). Direction). At this time, the claw piece 60 rides on the crest 64 of the base plate 12, so that the rotation of the guide plate 54 in the wire winding direction is not prevented. As described above, the pulley 22 and the guide plate 54 integrally rotate in the wire winding direction (the direction indicated by the arrow A in FIG. 2), and the portion of the wire 32 that is wound toward the hook 38 gradually becomes larger. It is wound by the diameter winding unit 28. As a result, the buckle 36 is also gradually drawn toward the webbing tensioning device 10, and the tension of the webbing (not shown) increases (pretension operation).

When the wire 32 is wound on the pulley 22, the wire 32 moves along the insertion hole 44 of the wire alignment plate 42. Thereby, two wires 32 (one end 3)
The wire 32 on the 2A side and the wire 32) on the other end 32B are wound around the large-diameter winding section 28 of the pulley 22 without being twisted or overlapping, and always arranged in the axial direction on the pulley 22.

As shown in FIG. 2, the buckle 36 comes closest to the webbing tensioning device 10 in a state where the piston 48 hits the inner wall 50A of the cylinder 50 and one end 32A of the wire 32 is drawn into the cylinder 50 as much as possible. And
The webbing (not shown) is tensioned at a predetermined tension (a tension higher than the normal state). As a result, the webbing wearer can be restrained by the vehicle seat with a large force.

When the user wears the webbing, for example, the buckle 36 moves in the direction away from the webbing tensioning device 10 when the user wears the webbing by inertia in the traveling direction of the vehicle. It receives a rotational force in the clockwise direction (arrow B directions in FIGS. 9 and 10).

At this time, as shown in FIG.
Since the taper surface 68 formed in the second accommodation recess 66 presses the roller 58 against the base plate 12, a frictional force is generated between the taper surface 68 and the roller 58 and between the base plate 12 and the roller 58, and the pulley 22 This is a resistance to rotation in the wire unwinding direction. In particular, in this state, the roller 58 is engaged with the valley 62, and
Since the roller 58 is pushed back by the inclined surface toward the slope 4, the frictional force generated between the tapered surface 68 and the roller 58 and between the base plate 12 and the roller 58 increases.

Further, since the tip of the claw piece 60 of the guide plate 54 is caught by the valley 62 of the base plate 12, the guide plate 54 is prevented from rotating in the wire unwinding direction. This prevents the pulley 22 from rotating in the wire unwinding direction. The amount of movement (return) of the buckle 36 in the direction away from the webbing tensioning device 10 is reduced, and the tension of the webbing (not shown) is maintained.

As described above, the roller 58 pressed toward the base plate 12 is engaged with the valley portion 62 with a simple configuration in which the surface of the base plate 12 facing the guide plate 54 is formed in a corrugated shape. , The nail pieces 60 can be hooked. Thereby, the resistance to the rotation of the pulley 22 and the guide plate 54 in the wire drawing direction can be increased.

In order to prevent the pulley 22 from rotating in the wire pull-out direction, for example, the pulley 22
There is no need to provide a separate member (such as the pawl 120 shown in FIG. 11) in the outside portion of the device, and the size of the reverse prevention device is reduced. As a result, the webbing tensioning device as a whole becomes smaller as compared with the conventional one.

In the above description, the case where the reverse rotation preventing device of the present invention is used for the webbing tensioning device 10 has been described as an example. However, as a device to which the reverse rotation preventing device of the present invention can be applied, It is a matter of course that the webbing tensioning device 10 is not limited to this.

In the above description, the pulley 22 as the moving means is replaced with the base plate 1 as the supporting means.
Although it is configured to rotate and move with respect to 2, the form of movement is limited to rotation, and such movement may be used as long as the moving means moves with respect to the support means. For example,
A rail may be provided on the support means, and the moving means may move along the rail. In this case, the movement trajectory of the moving means can be set arbitrarily according to the shape of the rail. As a driving means for moving the moving means,
The condition for moving the moving means is not limited to the above-described piston 48 but may be any as long as the moving means (the pulley 22) can be moved under a certain condition. Is appropriately set depending on the use conditions of each device used.

Further, the intermediate member is not limited to the roller 58. In short, when the moving means (the pulley 22) attempts to move the moving direction of the driving means in the opposite direction, it is pressed against the moving means or the supporting means (the base plate 12). Any member can be used. The pressing means is not limited to the tapered surface 68 described above, but may be any as long as the roller 58 is pressed against the base plate 12 when the pulley 22 tries to return. Similarly, the movement preventing means is not limited to the valleys 62 but may be the tapered surface 6.
It is sufficient if the roller 58 prevents the movement of the roller 58 pressed against the base plate 12. For example, engagement recesses with which the rollers 58 engage may be formed intermittently at regular intervals on the surface of the base plate 12 facing the guide plate 54. Further, pressing means (taper surface 6)
8) is formed on the supporting means (base plate 12), and the movement preventing means (valley 62) is formed on the moving means (pulley 2).
It may be formed in 2).

In addition, the wire aligning means is not limited to the above-described wire aligning plate 42, and a portion on one end 32A side and a portion on the other end 32B side of the wire 32 are arranged along the axial direction of the shaft 20. What is necessary is just to be able to be in a state. For example, if a member formed in a substantially “8” shape is used as a wire aligning means and two holes of this member are arranged along the axial direction of the shaft 20, these two holes can be inserted into the wire aligning plate 42. The same operation as the hole 44 is performed, and the wires 32 can be arranged in the axial direction of the shaft 20. The insertion hole 44 of the wire alignment plate 42 and the hole of the substantially “8” -shaped member do not necessarily need to be formed completely separated from each other. For example, an elongated hole through which two wires 32 can be inserted at the same time. In this case, substantially the same operation as in the case where two insertion holes 44 are formed may be employed.

The mounting portion of the wire aligning means is not limited to the accommodating portion 18 of the base plate 12, but may be a pulley 22.
Any portion that can align the wire 32 between the buckle 36 and the buckle 36 may be used. For example, hook 3 of buckle 36
8 may be attached to the lower end. In particular, when the wire 32 is attached to the housing portion 18 of the base plate 12 as in the present embodiment, the wire 32 extends substantially linearly from the hook 38 to the pulley 22 as compared with the case where the wire 32 is attached to the lower end of the hook 38. Therefore, the load on the wire 32 is reduced, and the assembling becomes easy.

[0060]

According to the first aspect of the present invention, the moving means to which the member to be moved is fixed, the supporting means for movably supporting the moving means, and the moving means being attached to the supporting means under certain conditions. Driving means for moving in a predetermined direction, an intermediate member disposed between the moving means and the supporting means, and provided on one of the moving means and the supporting means, wherein the moving means is When trying to return to the supporting means in the direction opposite to the moving direction by the driving means,
Pressing means for pressing the intermediate member toward one of the other of the moving means and supporting means, and movement of the intermediate member provided on one of the other of the moving means and the supporting means and pressed by the pressing means And the movement preventing means for preventing the movement of the moving means from returning to the support means is reduced, and the size of the reverse movement preventing device can be reduced.

According to a second aspect of the present invention, in the first aspect of the present invention, the movement preventing means is an engaging recess in which the intermediate member pressed against a moving means or a supporting means by the pressing means is engaged. Therefore, the movement preventing means can be configured with a simple structure.

According to the third aspect of the present invention, a pulley to which a wire extending from a buckle attached to the seat belt webbing is fixed, a base plate rotatably supporting the pulley, and Rotating means for rotating a pulley in the winding direction of the wire, a roller housed in a housing recess formed on a surface of the pulley facing the base plate, wherein the pulley has an axial direction, and a housing recess. And a tapered surface that presses the roller toward the base plate when the pulley tries to rotate in the wire pull-out direction, and engages with the roller formed on the base plate and pressed by the tapered surface. And an engagement portion for preventing the movement of the roller, so that the pulley is prevented from returning backward, The Ebingu tensioning device can be reduced in size.

According to a fourth aspect of the present invention, in the third aspect of the invention, the engaging portion is a valley formed by partially recessing a surface of the base plate facing the pulley. Therefore, the engaging portion can be configured with a simple structure, and the movement of the roller can be prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a webbing tensioning device using a reverse rotation prevention device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which the webbing tensioning device using the reverse rotation prevention device according to the embodiment of the present invention has wound up a wire.

FIG. 3 is a perspective view showing a pulley, a guide plate, and a roller of the reverse movement prevention device according to the embodiment of the present invention.

FIG. 4 is a perspective view showing a pulley, a guide plate, and a roller of the reverse movement prevention device according to the embodiment of the present invention.

FIG. 5 is a cross-sectional view taken along the line VV of FIG. 1 showing a webbing tensioning device using the reverse rotation preventing device according to the embodiment of the present invention.

FIG. 6 is a front view showing a wire alignment plate of the reverse rotation prevention device according to the embodiment of the present invention.

FIG. 7 is an enlarged cross-sectional view showing a base plate, a guide plate, a roller, and a pulley of the reverse rotation prevention device according to the embodiment of the present invention.

8 is a cross-sectional view showing a state in which the pulley has been rotated in the wire winding direction from the state shown in FIG. 7 in the reverse movement prevention device according to one embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a state in which the pulley is further rotated in the wire winding direction from the state shown in FIG. 8 in the reverse movement prevention device according to the embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a state in which the pulley attempts to rotate in the wire pull-out direction and the rotation is prevented in the reverse rotation preventing device according to the embodiment of the present invention.

FIG. 11 is a front view showing a conventional reverse rotation prevention device.

12 is a front view showing a state in which the conventional reverse rotation preventing device shown in FIG. 11 prevents the pulley from returning.

[Explanation of symbols]

 Reference Signs List 10 webbing tensioning device 12 base plate (supporting means) 22 pulley (moving means) 32 wire (moved member) 48 piston (rotating means, driving means) 58 roller (intermediate member) 62 valley (engaging portion, engaging concave portion, Movement inhibiting means) 68 Taper surface (pressing means)

Claims (4)

[Claims] 1. A moving means to which a member to be moved is fixed, a supporting means movably supporting the moving means, and a driving means for moving the moving means in a predetermined direction with respect to the supporting means under certain conditions. An intermediate member disposed between the moving unit and the supporting unit; and an intermediate member provided on one of the moving unit and the supporting unit, wherein the moving unit is driven by the driving unit with respect to the supporting unit. When trying to return in the reverse direction to the moving direction, pressing means for pressing the intermediate member toward the other of the moving means and the supporting means, and provided on one of the other of the moving means and the supporting means, And a movement preventing means for preventing movement of the intermediate member pressed by the pressing means. 2. The apparatus according to claim 1, wherein the movement preventing means is an engaging recess in which the intermediate member pressed against the moving means or the supporting means by the pressing means is engaged.
The device for preventing reverse movement according to claim 1. 3. A pulley to which a wire extending from a buckle attached to a seat belt webbing is fixed, a base plate rotatably supporting the pulley, and winding of the pulley in a state where the vehicle is rapidly decelerated. A rotating means for rotating the pulley in a housing recess formed in a surface of the pulley facing the base plate, a roller having a pulley whose axial direction is the axial direction; and A taper surface that presses the roller toward the base plate when trying to rotate in the wire pull-out direction; and a member that engages with the roller that is formed on the base plate and pressed by the taper surface to prevent the movement of the roller. A webbing tensioning device, comprising: a joining portion; 4. The webbing tensioning device according to claim 3, wherein the engaging portion is a valley formed by partially recessing a surface of the base plate facing the pulley.