WO2021124981A1

WO2021124981A1 - Pretensioner and seatbelt device

Info

Publication number: WO2021124981A1
Application number: PCT/JP2020/045639
Authority: WO
Inventors: 一貴池本; 良彦河合; 裕介井浦
Original assignee: ＪｏｙｓｏｎＳａｆｅｔｙＳｙｓｔｅｍｓＪａｐａｎ株式会社
Priority date: 2019-12-20
Filing date: 2020-12-08
Publication date: 2021-06-24
Also published as: JP2023007520A

Abstract

This pretensioner is provided with: a wire having one end connected to a buckle which is a drawn-in member; a piston connected to the other end of the wire; a cylinder that slidably accommodates the piston; and a gas generator that supplies to the piston a gas for operating the piston in a direction of drawing in the wire. The wire comprises a first wire and a second wire arranged in parallel between the buckle and the piston. The gas generator is arranged inside the cylinder.

Description

Pretensioner and seatbelt device

This disclosure relates to a pretensioner and a seatbelt device.

It has been proposed that the seatbelt device of a vehicle is provided with a pretensioner that operates in an emergency such as a vehicle collision and pulls in a retractable member such as a webbing or a buckle to increase the binding force of the occupant of the vehicle by webbing. There is.

For example, Patent Document 1 describes a wire whose one end is connected to the buckle of a seat belt device, a piston connected to the other end of the wire, a cylinder that slidably accommodates the piston, and a direction in which the wire is pulled in. A configuration is disclosed that includes a gas generator that supplies gas for operating the piston to the piston through a gas chamber in the housing.

Japanese Unexamined Patent Publication No. 2000-326823

By the way, in order to improve the initial restraint of the pretensioner, it is desired to increase the power of the pretensioner.

It is an object of the present disclosure to provide a pretensioner and a seatbelt device capable of generating a larger binding force.

The pretensioner according to one aspect of the embodiment of the present invention is a pretensioner that operates in an emergency and pulls in a retractable member to increase the binding force of a vehicle occupant by webbing, and is one of the retractable members. A wire to which one end is connected, a piston connected to the other end of the wire, a cylinder slidably accommodating the piston, and a gas for operating the piston in a direction in which the wire is pulled in. The first wire and the second wire are arranged in parallel between the retracted member and the piston, and the gas generator is the gas generator. It is placed inside the cylinder.

According to the present disclosure, it is possible to provide a pretensioner and a seatbelt device capable of generating a larger binding force.

It is an assembly perspective view of the pretensioner which concerns on embodiment. It is an exploded perspective view of the pretensioner shown in FIG. It is a vertical cross-sectional view of the state before the operation of the pretensioner shown in FIG. It is a vertical sectional view of the state after the operation of the pretensioner. It is sectional drawing which shows the positional relationship of a gas generator and a wire in an embodiment. It is a perspective view of the pretensioner which concerns on the 1st modification. It is sectional drawing which shows the positional relationship of a gas generator and a wire in 1st modification. It is a vertical sectional view around the piston of the pretensioner which concerns on the 2nd modification. It is sectional drawing of the pretensioner which concerns on 3rd modification. It is a block diagram of the seat belt device which concerns on embodiment. It is a partial perspective view of the pretensioner which concerns on 4th modification. It is a vertical sectional view of the pretensioner which concerns on 4th modification. 11 is a cross-sectional view taken along the line AA in FIG. It is a schematic diagram which shows the modification of the arrangement pattern of a gas flow path.

Hereinafter, embodiments will be described with reference to the attached drawings. In order to facilitate understanding of the description, the same components are designated by the same reference numerals as much as possible in each drawing, and duplicate description is omitted.

In the following description, the x-direction, the y-direction, and the z-direction are perpendicular to each other. Typically, the x and y directions are horizontal and the z direction is vertical. The x direction is the sliding direction of the piston 3, and the direction in which the buckle 7 is pulled in is the x positive direction. Further, the x direction is the vehicle front-rear direction when the pretensioner 1 is installed in the vehicle, the x positive direction side is the front side of the vehicle, and the x negative direction side is the rear side of the vehicle. The y direction is the vehicle width direction when the pretensioner 1 is installed in the vehicle.

[Embodiment]
An embodiment will be described with reference to FIGS. 1 to 5 and 10. FIG. 1 is an assembly perspective view of the pretensioner 1 according to the embodiment. FIG. 2 is an exploded perspective view of the pretensioner 1 shown in FIG. FIG. 3 is a vertical cross-sectional view of the pretensioner 1 shown in FIG. 1 in a state before operation. FIG. 10 is a configuration diagram of the seatbelt device 10 according to the embodiment.

As shown in FIG. 10, the seatbelt device 10 includes a webbing 11 (seatbelt) for restraining an occupant drawn out from the retractor 12. The retractor 12 is a device for winding the webbing 11, and is fixedly installed at the lower part of the center pillar 13 on the vehicle interior side. The webbing 11 extended from the retractor 12 to the upper part of the vehicle body is folded back toward the lower part of the vehicle body through the through ring 14 attached to the upper part of the center pillar 13. The tip of the webbing 11 is fixed to an anchor plate 16 provided between the center pillar 13 and the seat 15.

A tongue 17 is provided in the portion between the through ring 14 and the anchor plate 16 in the webbing 11 so that the webbing 11 can be inserted therethrough. The tongue 17 is attached to and detached from the buckle 7 arranged on the opposite side of the anchor plate 16 with the seat 15 in between.

The pretensioner 1 operates in an emergency such as a vehicle collision in the vehicle seatbelt device 10 to pull in a retractable member such as a webbing 11 or a buckle 7 to increase the binding force of the vehicle occupant by the webbing 11. It is a device for. As shown in FIGS. 1 and 10, in the present embodiment, as an example of the pretensioner 1, a buckle pretensioner of a type connected to the buckle 7 and pulling in the buckle 7 of the seatbelt device 10 will be described as an example.

As shown in FIGS. 1 to 3, the pretensioner 1 includes a wire 2 connected to the buckle 7, a piston 3 arranged on the wire 2, a cylinder 4 slidably accommodating the piston 3, and the piston 3. A gas generator 5 for applying a driving force and a bracket 6 connected to the cylinder 4 for positioning the wire 2 are provided.

The pretensioner 1 also has a function as a base of the buckle 7, and is fixed to the vehicle body by inserting a bolt 66 into the

fixing holes

61a and 62a formed in the bracket 6.

The bracket 6 has an outer member 61 and an inner member 62. The inner member 62 is housed inside the outer member 61, and a plurality of screws 67 are inserted and fixed between the outer member 61 and the inner member 62 to be integrated with the outer member 61.

The inner member 62 is provided with two

guide grooves

62b and 62c on the surface on the y negative direction side. The guide groove 62b is formed so as to be curved around the y-axis outward in the radial direction of the fixing hole 62a. The guide groove 62c is formed so as to be curved around the y-axis outside the fixing hole 62a in the radial direction with respect to the guide groove 62b. In a state where the inner member 62 is fitted to the outer member 61, a passage through which the wire 2 is inserted is formed by the

guide grooves

62b and 62c and the inner wall of the outer member 61 facing the

guide grooves

62b and 62c. To. The bracket 6 holds the bending angle of the wire 2 by inserting the wire 2 along the

guide grooves

62b and 62c when the inner member 62 is fitted to the outer member 61.

A buckle 7 is connected to one end of the wire 2.

The other end of the wire 2 is inserted into the piston 3 slidably arranged in the cylinder 4 via the bracket 6 and connected to the wire end 21 in the cylinder 4. An O-ring 33 for improving airtightness is arranged on the outer periphery of the piston 3. Further, a ball 32 and a ball ring 31 for suppressing reversion are arranged in the middle portion of the piston 3.

The gas generator 5 is arranged inside the cylinder 4 as shown in FIGS. 2 and 3, and more specifically, the gas generator 5 is housed in the internal space formed by the cylinder 4 and the bracket 6. The gas generator 5 is fitted in a recess 63a formed on the x-negative side end surface of the holding member 63, and movement in the x-positive direction, y-direction, and z-direction is restricted. The gas generator 5 is installed so as to inject gas from the tip portion in the x-positive direction facing the bottom surface of the recess 63a. A gas flow path 63b is communicated between the bottom surface of the recess 63a and the end surface on the x-positive direction side of the holding member 63.

Further, the fixing member 65 is attached to the holding member 63 from the x-negative direction side of the holding member 63, whereby the movement of the gas generator 5 with respect to the holding member 63 in the x-negative direction is restricted.

The holding member 63 is assembled to the inner member 62 of the bracket 6 in a state of being fitted to the end on the x-negative direction side of the cylinder 4.

A wire guide 64 is arranged between the holding member 63 and the piston 3. The wire guide 64 is fitted, for example, to the x-positive end surface of the holding member 63. The wire guide 64 also functions as a sealing member for improving the airtightness inside the cylinder 4.

Particularly in the present embodiment, in the wire 2, the first wire 2a and the second wire 2b are arranged in parallel between the buckle 7 as a retractable member and the piston 3. The first wire 2a is arranged so as to be curved around the y-axis outward in the radial direction of the fixing hole 62a and to be inserted into the guide groove 62b. The second wire 2b is arranged outside the fixing hole 62a in the radial direction with respect to the first wire 2a so as to be curved around the y-axis and inserted into the guide groove 62c. Further, in the cylinder 4, the first wire 2a is arranged on the z positive direction side (upper side) and the second wire 2b is arranged on the z negative direction side (lower side), and in this arrangement, the first wire 2a penetrates the piston 3 and is in the x positive direction. The side end is fixed to the piston 3 by the wire end 21.

A first insertion portion 63c through which the first wire 2a is inserted is provided on the z-positive direction (upper side) portion of the holding member 63 (see FIG. 5), and as shown in FIG. 3, a first insertion portion passing through the guide groove 62b is provided. The wire 2a is guided into the cylinder 4 and inserted into the wire guide 64. Similarly, a second insertion portion 63d through which the second wire 2b is inserted is provided in the z-negative direction (lower side) portion of the holding member 63 (see FIG. 5), and as shown in FIG. 3, the guide groove 62c is provided. The second wire 2b passing through the wire guide 64 is guided into the cylinder 4 and inserted into the wire guide 64.

Further, the first wire, 2a, and the second wire 2b are one wire member curved at the connecting portion with the buckle 7. With this configuration, the wire 2 and the buckle 7 can be connected by hanging the curved portion 2c between the first wire, the 2a, and the second wire 2b around the member of the buckle 7. This eliminates the need for ferrules required for the connecting portion in the case of the conventional single wire, and the height position of the buckle before operation can be lowered accordingly.

FIG. 5 is a cross-sectional view showing the positional relationship between the gas generator 5 and the wire 2 in the embodiment. The cross-sectional view of FIG. 5 is, for example, a cross-sectional view of a region of the cylinder 4 in FIG. 3 including the gas generator 5 in the longitudinal direction (x direction). As shown in FIG. 5, the first wire 2a and the second wire 2b connected to the piston 3 by the holding member 63 fitted inside the cylinder 4 and arranged side by side in the z direction (vertical direction). A gas generator 5 is arranged between them. With this configuration, the gas generator 5 can be housed in the cylinder 4 without hindering the movement of the wire 2, and space can be saved. At this time, the first wire 2a and the second wire 2b are arranged side by side in the cylinder 4 in the z direction, that is, in the vehicle vertical direction when the pretensioner 1 is installed in the vehicle. Further, the cylinder 4 is installed along the front-rear direction of the vehicle.

FIG. 4 is a vertical cross-sectional view of the state after the operation of the pretensioner 1. The gas generator 5 is connected to, for example, an acceleration sensor (not shown) that detects a vehicle collision, operates at the time of a vehicle collision, and ejects high-pressure gas into the cylinder 4 via the gas flow path 63b. The gas generator 5 generates gas by, for example, a built-in explosive.

The high-pressure gas ejected into the cylinder 4 presses the piston 3 and moves the piston 3 in the direction away from the bracket 6 (x positive direction) as shown in FIG. As the piston 3 moves, the wire 2 is pulled into the bracket 6 and the cylinder 4 and pulls the buckle 7 downward. As a result, the webbing (wrap belt) of the seatbelt device is tightened to strengthen the binding force applied to the occupant.

In the present embodiment, two wires, the first wire 2a and the second wire 2b, are arranged side by side over the entire area between the piston 3 and the buckle 7 which is a retractable member. As a result, as shown in FIG. 5, the dimensions of the piston 3 and the cylinder 4 in the wire parallel direction (z direction) increase, so that the area of the pressure receiving surface of the piston 3 that receives the high pressure gas supplied from the gas generator 5 increases. growing. The shape of the pressure receiving surface of the piston 3, that is, the end surface on the x-negative direction side is substantially circular in the configuration of one wire connected to the conventional piston 3, but in the present embodiment, the shape of the two wires 2a in the z direction is Since 2b are arranged side by side, they extend in the z direction to form an oval shape (a curved surface shape including an ellipse, an oval, an oval, etc., having a major axis and a minor axis, and convex outward). This shape is similar to the shape of the holding member 63 shown in FIG. Due to such a difference in shape, the area of the pressure receiving surface of the piston 3 is almost doubled or more as compared with the configuration in which one wire is connected to the conventional piston 3. Therefore, the force received by the piston 3 from the high-pressure gas is more than doubled, and the binding force transmitted to the buckle 7 via the wire 2 is also substantially doubled. Therefore, the pretensioner 1 of the present embodiment can be increased in power so as to generate a larger binding force, and the binding performance can be improved.

Further, in the present embodiment, in the wire 2, one wire member is curved 180 degrees at the center, and this curved portion is used as a curved portion 2c, and the first wire 2a and the second wire 2b are curved in the same direction from the curved portion 2c. And are arranged side by side to form a structure (loop structure) in which the curved portion 2c is connected to the retractable member (buckle 7). With such a loop structure, the wire 2 can be connected to the buckle 7 by hanging the curved portion 2c around the connecting portion of the buckle 7, so that a ferrule is provided at the connecting portion as in the conventional single wire structure. No need. Therefore, in order to realize a predetermined pull-in amount, the pull-out amount of the wire 2 from the bracket 6 can be shortened by the length of the ferrule, and the height position of the buckle 7 before the operation of the pretensioner 1 can be lowered. That is, if the stroke amount of the piston 3 is increased as compared with the conventional case, the pull-in amount of the buckle 7 can be increased without changing the height position of the buckle 7 or lowering the height position than before. As a result, the pretensioner 1 of the present embodiment can maintain the buckle position at the same level as the position of the current mass-produced product, and can have a long stroke to increase the pull-in amount of the buckle 7, further improving the restraint performance.

Further, since the pressure receiving surface of the piston 3 is oval-shaped, the cross section in the x-axis direction is oval-shaped even at the constricted portion where the ball 32 and the ball ring 31 are arranged in the middle portion of the piston 3. In particular, in the case of an oval shape having upper and lower semicircular portions and a straight portion connecting these semicircular portions, it is preferable that the ball 32 is arranged in the semicircular portion and not in the straight portion. When the ball 32 is arranged in the straight line portion, the straight line portion of the cylinder 4 pushed by the ball 32 from the inside is easily deformed so as to bulge outward, which may affect the locking performance of the piston 3 by the ball 32. This is to prevent the occurrence of such a situation. For example, the ball 32 is arranged in the semicircular portion by providing an element (for example, a protrusion) that can regulate the movement of the ball 32 at the boundary between the semicircular portion and the straight portion of the constricted portion of the piston 3, and the straight portion is formed. It is possible to realize a configuration that does not place.

[Modification example]
FIG. 6 is a perspective view of the pretensioner 1A according to the first modification. FIG. 7 is a cross-sectional view showing the positional relationship between the gas generator 5 and the wire 2 in the first modification.

As shown in FIG. 6, the arrangement of the first wire 2a and the second wire 2b connected to the buckle 7 in the cylinder 4 is in the horizontal direction, for example, the vehicle front-rear direction (x direction) when the pretensioner 1A is installed in the vehicle. May be. In this case, the cylinder 4 is installed along the left-right direction of the vehicle.

Further, as shown in FIG. 7, the first wire 2a and the second wire which are connected to the piston 3 by the holding member 63 which is fitted inside the cylinder 4 and are arranged side by side in the x direction (horizontal direction). A gas generator 5 is arranged between 2b.

In the first modification, the shape of the pressure receiving surface of the piston 3, that is, the end surface on the x negative direction side is an oval shape extending in the x direction. This shape is the same as the shape of the holding member 63 shown in FIG. 7, and is rotated 90 degrees around the y-axis of FIGS. 6 and 7 from the above embodiment. That is, since the area of the pressure receiving surface of the piston 3 can be increased as in the embodiment, the same effect as that of the above embodiment can be obtained.

FIG. 8 is a vertical cross-sectional view of the periphery of the piston 3 of the pretensioner 1B according to the second modification. In the above embodiment, the configuration in which the gas generator 5 is installed on the cylinder 4 side (fixed side) is illustrated, but as shown in FIG. 8, the gas generator 5 may be installed on the piston 3 side (movable side). Good.

In the configuration of FIG. 8, the gas generator 5 is located on the x-positive direction side of the piston 3, the wire end 21 connecting the ends of the first wire 2a and the second wire 2b to the piston 3, that is, the moving direction side of the piston 3. Is placed. The gas generator 5 is connected to the piston 3 by the support member 51.

The gas generator 5 and the wire end 21 are surrounded by a peripheral wall 34 extending in the x-positive direction from the peripheral surface of the piston 3, and a support member 51 is connected at the x-positive end of the peripheral wall 34. ing. The gas generator 5 is installed so as to inject gas from the tip portion on the x-negative direction side. One or a plurality of communication holes 35 are provided in the peripheral wall 34 so as to penetrate between the communication holes 35 and the outer peripheral surface of the piston 3, and high-pressure gas is injected from the communication holes 35 to move the piston 3 in the x-positive direction.

Further, in the above embodiment, the configuration in which the gas generator 5 is arranged between the first wire 2a and the second wire 2b is illustrated, but if the gas generator 5 is arranged at least inside the cylinder 4. Often, other arrangements may be made, such as, for example, the end of the bracket 6 on the x-negative direction of the first wire 2a and the second wire 2b. An example of such another arrangement will be described with reference to FIG.

FIG. 9 is a cross-sectional view of the pretensioner 1C according to the third modification. As shown in FIG. 9, in the pretensioner 1C of the third modification, the end portion 4A on the x-negative direction side of the cylinder 4 is provided so as to project from the bracket 6. The gas generator 5 is housed in the end 4A of the cylinder 4 protruding from the bracket 6 in the x-negative direction.

The gas generator 5 is arranged in the cylinder 4 on the side opposite to the piston 3 (x negative direction side) with respect to the wire 2 connected to the piston 3. That is, inside the cylinder 4, the gas generator 5, the wire 2, and the piston 3 are arranged in a straight line in this order from the x-negative direction side. The gas generator 5 is fixed to the x-negative side end portion 4A of the cylinder 4 by, for example, a support member 52, and is installed so as to inject gas from the x-positive direction side tip portion. The support member 52 is provided with a communication hole 53 on the x-positive direction side of the gas generator 5, and the gas generator 5 injects high-pressure gas from the communication hole 53 in the x-positive direction to inject the piston 3 in the x-positive direction. Move to the side.

In the pretensioner 1C of the third modification, since the movable part of the piston 3 and the holding part of the gas generator 5 are covered with an integrated cylinder 4, even if the pressure inside the cylinder 4 increases, it is one of the component parts. It is possible to prevent the portion from scattering to the outside of the cylinder 4. Further, since all the components can be stored in one cylinder 4, space efficiency can be improved.

FIG. 11 is a partial perspective view of the pretensioner 1D according to the fourth modification. FIG. 12 is a vertical cross-sectional view of the pretensioner 1D according to the fourth modification. FIG. 13 is a cross-sectional view taken along the line AA in FIG. In FIG. 11, the vicinity of the bracket 6 is magnified with the piston 3 and the cylinder 4 not shown.

As shown in FIGS. 12 and 13, the pretensioner 1D of the fourth modification is the gas generator 5 and the wire from the x negative direction inside the cylinder 4, similarly to the pretensioner 1C of the third modification. 2 (bracket 6) and the piston 3 are arranged in a straight line in this order.

In the pretensioner 1D of the fourth modification, as shown in FIGS. 12 and 13, the support member 54 for fixing the gas generator 5 to the end portion 4A on the x-negative direction side of the cylinder 4 is the x of the piston 3. It is formed so as to extend to the position of the wire guide 68 adjacent to the negative direction side. As shown in FIGS. 11 and 13, the support member 54 has a gas flow path 56 that allows gas generated from the gas generator 5 to flow to the piston 3 side in the cylinder 4. The gas flow path 56 flows gas in parallel with the first wire 2a and the second wire 2b along the extending direction of the cylinder 4.

As shown in FIG. 13, the support member 54 has two protrusions 55 at the tip on the x positive direction side. As shown in FIGS. 11 and 13, the two protrusions 55 are arranged side by side along the y direction, and are arranged on both sides of the wire 2 in the y direction. As shown in FIG. 11, the wire guide 68 is provided with two wire insertion holes 69, 69 through which the first wire 2a and the second wire 2b are inserted in the center in the y direction, and the wire insertion holes 69 are provided side by side in the z direction. Two gas supply holes 70, 70 are provided on both sides of the y-direction to allow these protrusions 55 to pass through.

As shown in FIGS. 11 and 13, the gas flow path 56 is opened in the protruding portion 55, and the protruding portion 55 is inserted into the gas supply hole 70 of the wire guide 68 and exposed to the piston 3 side. Gas can be supplied to the piston 3 side.

The shape of the gas flow path 56 is curved along the circumferential direction around the center of the cross-sectional circle of the cylinder 4 as shown in FIG. 11 when viewed from the x direction, and the upper end of the first wire 2a in the z direction. It is formed in an oval shape extending from the vicinity to the vicinity of the lower end of the second wire 2b.

Further, as shown in FIG. 12, the support member 54 having the gas flow path 56 completely separates the internal space of the bracket 6 through which the wire 2 is inserted and the space through which the gas flows.

As described above, the pretensioner 1D of the fourth modification includes a support member 54 having a gas flow path 56 for flowing the gas generated from the gas generator 5 to the piston 3 side in the cylinder 4, and the gas flow path 56 is The gas is flowed in parallel with the first wire 2a and the second wire 2b along the extending direction of the cylinder 4.

With this configuration, even if the gas generator 5 is arranged coaxially with the cylinder 4 and the bracket 6 is interposed between the gas generator 5 and the piston 3 inside the cylinder 4, the gas generated by the gas generator 5 Can be efficiently supplied to the piston 3 side by the gas flow path 56. Further, by flowing the gas in parallel with the wire 2 through the gas flow path 56, it is possible to prevent the gas generated by the gas generator 5 from being directly sprayed onto the wire 2 and the bracket 6, so that the pipe that the gas receives can be prevented. Loss such as road resistance can be reduced. As a result, sufficient gas pressure can be supplied to the piston 3 even if the gas generator 5 is miniaturized, so that the gas generator 5 and the pretensioner 1D as a whole can be miniaturized.

FIG. 14 is a schematic view showing a modified example of the arrangement pattern of the gas flow path. FIG. 14 illustrates four patterns as modified examples of the gas flow path arrangement pattern. For example, as shown in FIG. 14A, a plurality of gas flow paths 56A having a circular cross section are arranged side by side along the circumferential direction of the circular cross section of the cylinder 4, and are arranged in the lower half of the circular cross section. But it may be. Further, as shown in FIG. 14B, a plurality of gas flow paths 56B having a circular cross section are arranged side by side along the circumferential direction of the cross section circle of the cylinder 4, and both sides of the two wire insertion holes 69 in the y direction. The two wire insertion holes 69, 69 may be arranged in a range from the upper end in the z direction to the lower end in the z direction. Further, as shown in FIG. 14C, a single circular gas flow path 56C is arranged at positions equidistant from the centers of both sides of the two wire insertion holes 69 in the y direction, and the two wires. The insertion holes 69 and 69 may be arranged at intermediate positions in the z direction. Further, as shown in FIG. 14D, a single gas flow path 56D is formed so as to extend along the circumferential direction of the cross-sectional circle of the cylinder 4, and is arranged in the lower half of the cross-sectional circle. It may be configured.

The gas flow path 56 of the fourth modification shown in FIG. 11 and the other gas flow paths 56A to 56D shown in FIG. 14 are the first wires when viewed from the extending direction (x direction) of the cylinder 4. It is common in that it is arranged around 2a and the second wire 2b. With this configuration, the wire 2 and the gas flow path 56 can be compactly arranged in the region having a circular cross section of the cylinder 4, and the gas flow path can be provided while preventing the increase in the body shape of the cylinder 4.

Further, the shape of the gas flow path 56 of the fourth modified example shown in FIG. 11 and the shapes of the other gas flow paths 56A to 56D shown in FIG. 14 are when viewed in a circular cross section of the cylinder 4 in the x-direction view. As shown in FIG. 14 (A), the center line C (a line passing through the centers of the two wire insertion holes 69) extending in the z direction through the center of the cross section is formed to be line-symmetrical. It is common in that. By making the arrangement of the gas flow paths 56 line-symmetrical in this way, it is possible to evenly inject the gas onto the end face on the x-negative direction in which the piston 3 receives the gas. As a result, it is possible to efficiently apply a force for the piston 3 to move in the x-positive direction, and it is possible to suppress energy loss and slide the piston 3 more smoothly.

The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Those skilled in the art with appropriate design changes to these specific examples are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Each element included in each of the above-mentioned specific examples, its arrangement, conditions, shape, and the like are not limited to those illustrated, and can be changed as appropriate. The combinations of the elements included in each of the above-mentioned specific examples can be appropriately changed as long as no technical contradiction occurs.

In the above embodiment, the buckle pretensioner in which the retractable member of the pretensioner 1 is the buckle 7 is illustrated, but the retractable member may be a webbing (wrap belt). In this case, the pretensioner also functions as a belt anchor.

In the above embodiment, the wire 2 exemplifies a configuration in which one wire member is curved 180 degrees at the center and the first wire 2a and the second wire 2b are arranged side by side, but at least the piston 3 and the retracted member are illustrated. It suffices if two wires can be arranged side by side with (buckle 7), and the first wire 2a and the second wire 2b may be provided as separate members.

This international application claims priority based on Japanese Patent Application No. 2019-230585 filed on December 20, 2019, and the entire contents of No. 2019-230585 are incorporated herein by reference.

1, 1A, 1B, 1C, 1D Pretensioner 2 Wire 2a 1st wire 2b 2nd wire 3 Piston 4 Cylinder 5 Gas generator 7 Buckle (retracted member)
10 Seatbelt device 11 Webbing 54

Support member

56, 56A, 56B, 56C, 56D Gas flow path

Claims

A pretensioner that operates in an emergency and pulls in the retractable member to increase the binding force of the vehicle occupants by webbing.
A wire to which one end is connected to the retracted member,
With a piston connected to the other end of the wire,
A cylinder that slidably accommodates the piston,
A gas generator that supplies gas for operating the piston in a direction in which the wire is pulled in, and a gas generator that supplies the piston.
With
In the wire, the first wire and the second wire are arranged in parallel between the retractable member and the piston.
The gas generator is located inside the cylinder.
Pretensioner.
The gas generator is arranged inside the cylinder between the first wire and the second wire connected to the piston.
The pretensioner according to claim 1.
The gas generator is arranged inside the cylinder on the side opposite to the piston with respect to the wire connected to the piston, and is installed so as to inject gas to the piston side.
The pretensioner according to claim 1.
A support member having a gas flow path for flowing gas generated from the gas generator to the piston side in the cylinder is provided.
The gas flow path flows gas in parallel with the first wire and the second wire along the extending direction of the cylinder.
The pretensioner according to claim 3.
The gas flow path is arranged around the first wire and the second wire when viewed from the extending direction of the cylinder.
The pretensioner according to claim 4.
The first wire and the second wire are one wire member curved at a connecting portion with the retracted member.
The pretensioner according to any one of claims 1 to 5.
The retractable member is a buckle.
The pretensioner according to any one of claims 1 to 6.
The first wire and the second wire are arranged side by side in the vertical direction in the cylinder when installed in the vehicle.
The cylinder is installed along the front-rear direction of the vehicle.
The pretensioner according to claim 7.
The first wire and the second wire are arranged side by side in the horizontal direction in the cylinder at the time of installation in the vehicle.
The cylinder is installed along the left-right direction of the vehicle.
The pretensioner according to claim 7.
A seatbelt device including the pretensioner according to any one of claims 1 to 9.