WO2012011344A1

WO2012011344A1 - Seatbelt retractor

Info

Publication number: WO2012011344A1
Application number: PCT/JP2011/063882
Authority: WO
Inventors: 和範山咲; 将崇田中
Original assignee: 芦森工業株式会社
Priority date: 2010-07-20
Filing date: 2011-06-17
Publication date: 2012-01-26
Also published as: JP2012025207A

Abstract

A seatbelt retractor provided with a pretensioner mechanism section which, in a collision, etc. of the vehicle, winds webbing by rotating a winding drum in the winding direction. The pretensioner mechanism section is provided with: a gas generation member for generating gas; a long tube-shaped cylinder having one end to which the gas generation member is mounted; a piston movably contained within the cylinder and rotating the winding drum in the winding direction by being pressed and driven within the cylinder by the pressure of the gas generated by the gas generation member; and seal members mounted so as to be superposed on the end of the piston, which is located on the side which is subjected to the gas pressure, and sealing between the piston and the inner wall of the cylinder. The seal members comprise at least two types of seal members having different characteristics of resistance to the environment.

Description

Seat belt retractor

The present invention relates to a seat belt retractor for removing slack of webbing in an emergency such as a vehicle collision.

Conventionally, various seat belt retractors for removing slack of a seat belt in an emergency such as a vehicle collision have been proposed.
For example, a seal member composed of an O-ring is placed on the pressure-receiving side surface that receives the gas pressure of a substantially cylindrical piston that is slidably held in a cylinder and has a rack, and further, a circular member is placed on the O-ring. There is a retractor for a seat belt provided with a print tensioner mechanism in which plate-shaped pressure receiving plates are arranged in an overlapping manner (see, for example, JP-A-9-202213).

In the above-described conventional pretensioner mechanism for a seatbelt retractor, the seal member formed of an O-ring is often formed of an elastic material such as rubber. Such rubber materials generally tend to sacrifice high temperature characteristics if they are excellent in low temperature characteristics, and conversely tend to sacrifice low temperature characteristics if they are excellent in high temperature characteristics. There is. On the other hand, the pull-in performance of the webbing when the pretensioner mechanism of the seat belt retractor is operated, under all temperature environments where the automobile can be used, that is, from cold regions such as polar regions to tropical regions such as deserts just below the equator, It is necessary to secure in a wide area from low temperature environment to high temperature environment.

Accordingly, the present invention has been made to solve the above-described problems, and is a sheet that can ensure the pull-in performance of the webbing of the pretensioner mechanism in a wide area from a low temperature environment to a high temperature environment. An object is to provide a retractor for a belt.

In order to achieve the above object, a retractor for a seat belt of the present invention includes a winding drum that winds and stores a webbing, a housing that rotatably supports the winding drum, and the winding drum in an emergency such as a vehicle collision. A retractor for a seat belt comprising a pretensioner mechanism that winds the webbing by rotating the webbing direction, wherein the pretensioner mechanism includes a gas generating member that generates gas and the gas generating at one end. A long cylindrical cylinder on which a member is mounted, and the winding drum is driven in the winding direction by being pressed and driven in the cylinder by the pressure of gas generated from the gas generating member that is movably accommodated in the cylinder And a piston that is rotated so as to overlap the gas pressure side end of the piston, and the piston and the inner wall of the cylinder And a plurality of seal members for sealing between said plurality of sealing members is characterized by having at least two sealing members different environmental resistance.

In such a seat belt retractor, at least two types of seal members having different environmental resistances are attached to the gas pressure side end of the piston movably accommodated in the cylinder of the pretensioner mechanism, The gap between the piston and the inner wall of the cylinder is sealed. Thereby, it becomes possible to ensure the pull-in performance of the webbing of the pretensioner mechanism in a wide area from a low temperature environment to a high temperature environment.

In the seat belt retractor of the present invention, the plurality of seal members may include a seal member formed of silicone rubber and a seal member formed of nitrile rubber.

In such a seatbelt retractor, a seal member made of silicone rubber and a seal member made of nitrile rubber are provided at the gas pressure side end of the piston movably accommodated in the cylinder of the pretensioner mechanism. And are attached. As a result, the webbing retractability of the pretensioner mechanism can be reduced from a low temperature environment to a high temperature environment by using a seal member formed of silicone rubber with excellent low temperature characteristics and a seal member formed of nitrile rubber with excellent high temperature characteristics. It will be possible to ensure in a wide area.

In the seatbelt retractor of the present invention, the piston has a mounting recess with a predetermined depth formed on an end surface on the gas pressure receiving side, and the plurality of seal members are end surfaces on the gas pressure receiving side of the piston. The first seal member having a through-hole formed at a position facing the mounting recess and substantially the same as the end surface on the gas pressure receiving side of the piston And a second seal member having a mounting convex portion standing at a position facing the mounting concave portion, wherein the mounting convex portion is the first seal. It may be inserted into the through hole of the member and fitted into the piston by being fitted into the mounting recess of the piston.

In such a seatbelt retractor, the mounting convex portion of the second seal member is inserted into the through hole of the first seal member, and the mounting convex portion is formed at a predetermined depth formed on the pressure receiving side end surface of the piston. By fitting into the mounting recess, the flat plate-like first seal member and the second seal member can be overlapped and integrally assembled to the pressure-receiving side end surface of the piston, and the mounting work efficiency can be improved. .

Further, since the first seal member and the second seal member are flat plate members having substantially the same shape as the end surface on the gas pressure receiving side of the piston, the piston to which each seal member is attached is inserted into the cylinder from the pressure receiving surface side. At this time, it is possible to prevent torsion, displacement, disengagement, and the like due to friction with the cylinder inner wall of each seal member. As a result, it is possible to reliably prevent deterioration of the sealing performance due to improper mounting of each sealing member, and to ensure the webbing retraction performance of the pretensioner mechanism in a wide range of areas from low to high temperatures. It becomes.

In the seatbelt retractor according to the present invention, the second seal member has a gas vent hole formed so as to penetrate the mounting convex portion in the thickness direction, and the piston extends from the mounting concave portion. You may make it have a communicating hole formed so that it may penetrate along the moving direction of the said piston.

In such a seat belt retractor, the gas vent hole of the second seal member and the communication hole of the piston communicate with each other. As a result, when the seat belt retractor is provided with an energy absorbing mechanism that pulls out the webbing and reduces the impact on the occupant when the pulling force acting on the webbing exceeds a predetermined value, the piston is When moving to the normal position, the residual gas remaining in the cylinder between the second seal member and the gas generating member can be released to the outside through the vent hole and the communication hole, and the pressure of the residual gas is energy. It is possible to prevent the operation of the absorption mechanism from being hindered.

Further, since the mounting convex portion of the second seal member is hollow, it is easy to bend and can be easily fitted into the mounting concave portion of the piston, and the work efficiency of attaching the first seal member and the second seal member to the piston is further improved. Improvements can be made.

Furthermore, in the seatbelt retractor of the present invention, the first seal member may be formed of silicone rubber, and the second seal member may be formed of nitrile rubber.

In such a seat belt retractor, of the first seal member and the second seal member, the second seal member in which the high-temperature gas generated from the gas generating member directly contacts the pressure receiving side surface is made of nitrile rubber having excellent high-temperature characteristics. By forming, it is possible to secure the webbing retraction performance of the pretensioner mechanism in a wide area from a low temperature environment to a high temperature environment while protecting the first seal member formed of silicone rubber from high temperature gas. it can. In addition, a first seal member formed of silicone rubber having excellent low temperature characteristics is disposed between the pressure-receiving side end surface of the piston and a second seal member formed of nitrile rubber, so that a pretensioner in a low temperature environment is provided. It becomes possible to ensure the pull-in performance of the webbing of the mechanism part.

1 is an external perspective view of a seatbelt retractor according to the present embodiment. It is the perspective view which decomposed | disassembled the seatbelt retractor for every unit. It is a disassembled perspective view of a pretensioner unit. It is a disassembled perspective view of a pretensioner unit. It is a partially cutaway side view of a pretensioner unit. It is the perspective view seen from the pressure receiving surface side of the piston. It is sectional drawing of a piston. It is a principal part expanded sectional view of the pipe cylinder of FIG. It is a disassembled perspective view of a housing unit. It is a side view of the state which removed the lock unit of the retractor for seatbelts. It is explanatory drawing which shows the state which the piston moved by the action | operation of the gas generation member of the pretensioner mechanism, and the lower end part of the rotation lever removed from the front-end | tip part of a gear side arm. It is explanatory drawing which shows the operation | movement of the pawl corresponding to FIG. It is a drawing-in performance comparison table which shows an example of the comparison result which compared drawing-in performance of webbing. It is a perspective view which shows an example of the 1st seal plate and 2nd seal plate which concern on other Embodiment 1. FIG. It is a principal part expanded sectional view of the pipe cylinder which shows an example which attached the 1st seal plate and 2nd seal plate of FIG. 14 to the piston. It is the perspective view seen from the pressure receiving surface side of the piston which concerns on other Embodiment 2. FIG. It is a principal part expanded sectional view of the pipe cylinder which shows an example of the 1st seal plate and 2nd seal plate which were attached to the piston of FIG. It is a principal part expanded sectional view of the pipe cylinder which shows an example which attached the 1st seal member and 2nd seal member which were formed in frame shape concerning other Embodiment 3 to the piston.

Hereinafter, a retractor for a seat belt according to an embodiment of the present invention will be described in detail with reference to the drawings based on an embodiment.

[Schematic configuration]
First, a schematic configuration of the seatbelt retractor 1 according to the present embodiment will be described with reference to FIGS. 1 and 2.
FIG. 1 is an external perspective view of a seatbelt retractor 1 according to this embodiment. FIG. 2 is an exploded perspective view of the seat belt retractor 1 for each unit.

As shown in FIGS. 1 and 2, the seat belt retractor 1 is a device for winding a webbing 3 of a vehicle, and includes a housing unit 5, a winding drum unit 6, a pretensioner unit 7, and a winding. A spring unit 8 and a lock unit 9 are included.
The lock unit 9 is fixed to the side wall portion 12 of the housing 11 constituting the housing unit 5 and is activated to stop the withdrawal of the webbing 3 in response to a sudden change of the webbing 3 or a rapid acceleration of the vehicle. Perform the action.

Further, the pretensioner unit 7 provided with a pretensioner mechanism 17 (see FIG. 3), which will be described later, is substantially omitted from the upper and lower end edges of the

side plate portions

13 and 14 facing each other of the substantially U-shaped housing unit 5 in plan view. Each screw 15 inserted through from the outside of the pretensioner unit 7 is inserted into the

screw fixing portions

13A, 13B, 14A formed with screw holes by extending in a right angle inner direction and the pin fixing portions 14B formed with through holes. The stopper pin 16 is screwed and inserted from the inside of the housing 11 and is fixed by a push nut 18 inserted into the stopper pin 16. Thereby, the pretensioner unit 7 constitutes the other side wall portion facing the side wall portion 12 of the housing 11.

Further, the take-up spring unit 8 is fixed to the outside of the pretensioner unit 7 by each ny latch 8A integrally formed with the spring case 19.
The take-up drum unit 6 around which the webbing 3 is wound is rotatably supported between a lock unit 9 fixed to the side wall 12 of the housing unit 5 and the pretensioner unit 7. The winding drum unit 6 includes a guide drum 21, a drum shaft 22, a wire plate 25, a ratchet gear 26, and the like.

The guide drum 21 is formed of an aluminum material or the like, and is formed in a substantially cylindrical shape in which the end surface portion on the pretensioner unit 7 side is closed. Further, a flange portion 27 extending in the radial direction from the outer peripheral portion and further extending in a substantially right-angled outward direction is formed on the end edge portion on the pretensioner unit 7 side in the axial direction of the guide drum 21. . In addition, a clutch gear 30 is formed on the inner peripheral surface of the flange portion 27 to which the clutch pawls 29 (see FIG. 3) are engaged and the rotation of the pinion gear body 33 (see FIG. 3) is transmitted in the event of a vehicle collision. ing.

Further, a cylindrical mounting boss 31 is erected at the center position of the end surface portion of the guide drum 21 on the pretensioner unit 7 side, and a drum shaft 22 formed of a steel material or the like is fixed by press fitting or the like. Further, the mounting boss 31 is fitted into a cylindrical portion 32A (see FIG. 3) of the bearing member 32 formed of a synthetic resin material such as polyacetal constituting a clutch mechanism 48 (see FIG. 3) described later.

Thus, one end side of the winding drum unit 6 is rotatably supported by the bearing portion 33A (see FIG. 4) of the pinion gear body 33 constituting the pretensioner unit 7 via the bearing member 32. In addition, the tip of the drum shaft 22 of the winding drum unit 6 is coupled to a spiral spring in the winding spring unit 8, and the winding drum unit 6 is always biased in the winding direction of the webbing 3 by the biasing force of the spiral spring. Structured.

Further, on the lock unit 9 side of the guide drum 21 in the axial direction, a flange portion 35 extending in the radial direction from the outer peripheral surface slightly inside from the end edge portion is formed. Further, the outer peripheral portion of the flange portion 35 is covered with a wire plate 25 having a substantially oval shape in a side view formed of an aluminum material or the like. A ratchet gear 26 is fixed to the outer central portion of the wire plate 25 by caulking or the like.

The ratchet gear 26 has a disc shape formed of steel or the like, and a ratchet gear portion 26A that engages with a pawl 37 (see FIG. 9) in an emergency such as a vehicle collision as described later is formed on the outer peripheral surface. Has been. A shaft portion 28 is erected at the center position on the outer side of the ratchet gear 26. A spline is formed on the outer peripheral surface of the shaft portion 28, and the winding drum unit 6 is rotatably supported by the lock unit 9 via the shaft portion 28.

[Schematic configuration of pretensioner unit]
Next, a schematic configuration of the pretensioner unit 7 will be described with reference to FIGS.
3 and 4 are exploded perspective views in which the pretensioner unit 7 is disassembled. FIG. 5 is a partially cutaway side view of the pretensioner unit 7. FIG. 6 is a perspective view of the piston 47 as seen from the pressure receiving surface side. FIG. 7 is a sectional view of the piston 47. FIG. 8 is an enlarged sectional view of a main part of the pipe cylinder 42 of FIG.

As shown in FIGS. 2 to 4, the pretensioner unit 7 includes a pretensioner mechanism 17, a forced lock mechanism 51 that rotates a pawl 37 (see FIG. 10) pivotally supported on the side wall portion 12 of the housing unit 5, and And the cover plate 53.

[Pretensioner mechanism]
As shown in FIGS. 3 to 5, the pretensioner mechanism 17 operates the gas generating member 41 in an emergency such as a vehicle collision, and uses the gas pressure by the gas generating member 41 to flange the winding drum unit 6. This is a mechanism for rotating the winding drum unit 6 in the winding direction of the webbing 3 via a portion 27.

Here, the pretensioner mechanism 17 includes a gas generating member 41, a pipe cylinder 42, a first seal plate 43, a second seal plate 44, and a piston that move in the pipe cylinder 42 under the gas pressure of the gas generating member 41. 47, a pinion gear body 33 that rotates in mesh with a rack 47A formed on the piston 47, a base plate 45 to which the pipe cylinder 42 is attached, and a base plate 45 that contacts the side surface of the pipe cylinder 42 on the pinion gear body 33 side. The base block body 46 is disposed in contact with the base block body 46, and the clutch mechanism 48 is disposed on the outer surface of the base plate 45.

Further, the pinion gear body 33 has a substantially cylindrical shape formed of a steel material or the like, and a pinion gear portion 55 that meshes with a rack 47A formed on the piston 47 is formed on the outer periphery thereof. Further, a cylindrical support portion 56 extending outward from the end portion of the pinion gear portion 55 on the axial direction cover plate 53 side is formed. The support portion 56 is formed to have a length substantially equal to the thickness dimension of the cover plate 53 with the valley diameter of the pinion gear portion 55 as an outer diameter.

Further, a flange portion 57 projecting in the radial direction is formed at an end portion of the pinion gear portion 55 on the axial base plate 45 side. Furthermore, the boss 58 is formed with a bearing 33A into which the cylindrical shaft 32A of the bearing member 32 is inserted while the drum shaft 22 of the winding drum unit 6 is inserted in a substantially cylindrical shape outward from the flange 57. Is formed. Further, on the outer peripheral surface of the boss portion 58, three splines each having an outer diameter of the base end portion are formed at intervals of about 120 degrees of the central angle.

The clutch mechanism 48 includes a bearing member 32 formed of a synthetic resin material such as polyacetal, a substantially annular pawl base 61 formed of a steel material, and three clutch pawls formed of a steel material. 29 and a substantially annular pawl guide 62 that is formed of a synthetic resin such as polyacetal and sandwiches each clutch pawl 29 together with the pawl base 61.

As shown in FIGS. 3 and 4, the bearing member 32 has a substantially cylindrical shape in which a cylindrical mounting boss 31 erected at the center position of the end surface portion of the guide drum 21 on the pretensioner unit 7 side is rotatably fitted. The cylindrical portion 32 A and an annular flange portion 32 B extending radially outward from the outer periphery of the edge portion of the cylindrical portion 32 A on the guide drum 21 side.

Further, on the peripheral edge of the flange portion 32B, there are formed three projecting portions 32C extending in the form of a tapered flat plate having a substantially triangular shape when viewed from the front at an interval of about 120 degrees in the central angle. Further, the locking piece 32D is arranged at the distal end portion in the radial direction of each projecting portion 32C so as to face the outer peripheral surface of the cylindrical portion 32A in the axial direction, rather than the thickness dimension of the clutch mechanism 48. It is erected with a slightly lower height. Furthermore, an engaging protrusion is formed at the tip of each locking piece 32D and protrudes in a substantially right triangle shape in a side section in a substantially right angle outward direction.

As shown in FIGS. 3 and 4, on the inner peripheral surface of the pawl base 61, there are three spline grooves into which a spline formed on the boss portion 58 of the pinion gear body 33 is press-fitted at an interval of about 120 degrees in the central angle. It is formed one by one. Further, the pawl base 61 has three insertion holes 65 into which the rotation support shafts 29A of the respective clutch pawls 29 are rotatably fitted, and the pawl base 61 is thick so as to surround each insertion hole 65 on the outer diameter side of the pawl base 61. Each pawl support block 66 is provided. A locking block 67 is formed at the outer diameter end of each pawl support block 66.

Further, when the cylindrical portion 32A of the bearing member 32 is inserted into the pawl base 61, the flange portion 32B and the respective protruding portions 32C are fitted into the surface of the pawl base 61 on the guide drum 21 side. A hollow portion 68 having a substantially triangular shape in front view is formed. The depth of the recessed portion 68 is formed to have a depth dimension substantially equal to the thickness of each flat plate-like protruding portion 32C. In addition, each through hole 69 through which each locking piece 32 D of the bearing member 32 is inserted is formed at each vertex portion of the bottom surface of the recess 68.

As shown in FIGS. 3 and 4, the inner peripheral diameter of the pawl guide 62 is formed larger than the spline groove of the pawl base 61, and the axially outer side surface portion of the pawl guide 62 is 3 Each of the long and narrow positioning protrusions 71 protrudes along the radial direction at intervals of a central angle of 120 degrees. Further, three locking hooks 72 that engage with the locking blocks 67 of the pawl base 62 are formed on the outer periphery of the pawl guide 62.

Then, the rotational support shafts 29A of the clutch pawls 29 are fitted and placed in the through holes 69 of the pawl base 61, and the locking hooks 72 of the pawl guide 62 are connected to the locking blocks 67 of the pawl base 61 from above. By engaging with each other, each clutch pawl 29 is held in a state of being accommodated rotatably about the rotation support shaft 29. Subsequently, each positioning protrusion 71 protruding from the axially outer side surface portion of the pawl guide 62 of the clutch mechanism 48 is fitted into each positioning hole 75 of the base plate 45, so that the clutch mechanism 48 is attached to the base plate 45. Place on the outside.

After that, after the boss portion 58 of the pinion gear body 33 is fitted into the through hole 76 formed in the substantially central portion of the base plate 45, each spline formed in the boss portion 58 is replaced with each of the pawl base 61 constituting the clutch mechanism 48. Press fit into the spline groove. Thus, the clutch mechanism 48 and the pinion gear body 33 are disposed and fixed on the base plate 45, and the pinion gear portion 55 of the pinion gear body 33 is always positioned and fixed at the position shown in FIG.

As a result, as will be described later, when the pinion gear body 33 rotates in an emergency such as a vehicle collision, the pawl base 61 rotates and the clutch pawls 29 rotate outward in the radial direction. After projecting outward in the radial direction, it meshes with the clutch gear 30 of the guide drum 21. Further, when the pinion gear body 33 rotates, each positioning protrusion 71 of the pawl guide 62 is sheared, and the clutch mechanism 48 and the guide drum 21 rotate in the winding direction of the webbing 3.

Subsequently, as shown in FIG. 3 and FIG. 4, the cylindrical portion 32 A is fitted into the bearing portion 33 A of the pinion gear body 33 while inserting the locking pieces 32 D of the bearing member 32 into the through holes 69 of the pawl base 61. To do. Then, the flange portion 32 B and each projecting portion 32 C of the bearing member 32 are fitted into the recessed portion 68. As a result, the both side surfaces of each protrusion 32C of the bearing member 32 are disposed so as to oppose the inner surface of each apex portion of the recess 68, and therefore the bearing member 32 cannot rotate relative to the pawl base 61. Attached to.

The base block body 46 is made of a synthetic resin such as polyacetal. The gear housing 81 is formed in a substantially semicircular shape in a plan view from the side edge on the inner side of the base block body 46 and formed in a substantially ring shape with a bottom surface protruding outward. The flange portion 57 of the pinion gear body 33 is inserted into the through hole 82 in the bottom surface portion. Further, each positioning boss 83 protruding from the side surface portion of the base block body 46 on the base plate 45 side is fitted into each positioning hole 85 of the base plate 45, and the base block body 46 is disposed on the inner surface of the base plate 45. .

Further, the base block body 46 faces the piston housing part 42B in which the piston 47 is housed from the lower end part facing the housing part 42A in which the gas generating member 41 of the pipe cylinder 42 is housed to the position near the housing part 42A. Thus, the block extension part 87 extended by a predetermined width (for example, about 10 mm width) with the same thickness is formed. A through-hole 89 through which a screw 88 (see FIG. 2) is inserted is formed at the lower end of the block extension 87.

Also, an elastic locking piece 46A extending from the outer side surface portion of the base block body 46 to the base plate 45 side and formed to be elastically deformable in the outer direction, and the upper side surface portion and the lower side surface of the base block body 46 Each elastic locking piece 46 B extending from the portion toward the base plate 45 and elastically deformable in the outward direction is locked to the side end of the base plate 45. As a result, the base block body 46 is disposed on the base plate 45.

Note that the height of the gear housing portion 81 is formed to be approximately equal to the sum of the heights of the pinion gear portion 55 and the flange portion 57 of the pinion gear body 33.

[Forced locking mechanism]
Here, the forced lock mechanism 51 disposed in the base block body 46 will be described with reference to FIGS. 3 to 5.
As shown in FIGS. 3 to 5, the base block body 46 is formed with a recess 91 in which the forced lock mechanism 51 is disposed, and a push block 92 that constitutes the forced lock mechanism 51, a rotary lever 93, A block urging spring 92A for urging the push block 92 in the direction of the rotation lever 93, a gear side arm 94, and a urging spring 95 for urging the gear side arm 94 in the direction of the rotation lever 93 are provided. ing. The gear side arm 94 is connected to a connecting shaft 96 constituting the forced lock mechanism 51 and a mechanical side arm 97 from the outside of the base plate 45.

The rotary lever 93 is formed of a synthetic resin such as polyacetal, an aluminum material, or the like, and is formed in a substantially square shape, and a through hole is formed in a bent portion. As shown in FIG. 5, the rotary lever 93 is rotatable on a boss 98 erected on the bottom surface of the concave portion 91 of the base block body 46 so that one end side thereof faces the pinion gear portion 55 of the pinion gear body 33. It is supported.

The push block 92 is made of a synthetic resin such as polyacetal. As shown in FIG. 5, the push block 92 has one end positioned near the teeth of the pinion gear portion 55 of the pinion gear body 33 and the other end thereof by the positioning protrusion 101 erected on the bottom surface portion of the recess 91. It is positioned so as to be located in the vicinity of the rotation lever 93. Further, the push block 92 is urged toward the rotating lever 93 by a block urging spring 92A to prevent rattling.

Therefore, when the pinion gear body 33 rotates as will be described later, the rotation lever 93 can be rotated outward (counterclockwise in FIG. 5) by the push block 92 pushed by the teeth of the pinion gear portion 55. It is configured (see FIG. 11). The push block 92 is prevented from returning to the pinion gear body 33 side by the block biasing spring 92A.

Further, the gear side arm 94 is formed of a synthetic resin such as polyacetal, an aluminum material or the like and is formed in a substantially flat plate shape, and at one end side far from the rotation lever 93 on the side surface portion on the base block body 46 side, A boss 103 is erected to be inserted into the through hole 102 formed in the bottom surface portion of the recess 91 of the base block body 46. Further, a groove portion 105 having a predetermined depth through which the bent portion on one end side of the connecting shaft 96 is inserted is formed on a side surface portion where the boss 103 of the gear side arm 94 is erected.

Further, the gear side arm 94 has a stepped portion 106 formed on the upper surface of the distal end portion on the rotating lever 93 side so that the other end side of the rotating lever 93 abuts. The gear side arm 94 is rotatably supported on the rotating lever 93 side by inserting the boss 103 into the through hole 102 formed in the bottom surface of the recess 91. Further, the gear side arm 94 is urged by the urging spring 95 on the lower surface of the other tip portion facing the step portion 106 (in the upward direction in FIG. 5), and the step portion 106. Is in contact with the other end of the rotary lever 93.

Therefore, when the rotary lever 93 is rotated counterclockwise in FIG. 5, the other end of the rotary lever 93 is separated from the tip of the gear side arm 94, and the gear side arm 94 is attached to the biasing spring 95. It is configured to be able to rotate outward (in the counterclockwise direction in FIG. 5) by the force.

The connecting shaft 96 is formed of a wire material such as a steel material, and is bent at a substantially right angle so that both ends face each other with a shift of about 90 degrees. Also. The length of the straight portion of the connecting shaft 96 is slightly longer than the width of the

side plate portions

13 and 14 of the housing unit 5 (see FIG. 9).

Further, as shown in FIG. 4, a groove 107 through which the bent portion on one end side of the coupling shaft 96 is inserted extends from the outer peripheral portion in the through hole 102 formed in the bottom surface portion of the concave portion 91 of the base block body 46. ing. Further, a through hole 108 through which the one end side bent portion of the connection shaft 96 is inserted is formed in a portion of the base plate 45 facing the gear side arm 94.

Therefore, the one end side bent portion of the connecting shaft 96 passes through the through hole 108 of the base plate 45, the through hole 102 and the groove 107 of the base block body 46, and the gear side disposed in the recess 91 of the base block body 46. The arm 94 is inserted into the groove 105.

The mechanical arm 97 is formed of a synthetic resin such as polyacetal, aluminum, or the like, and is formed into a substantially flat plate-like narrow fan shape, and on the outer surface of the edge on the central angle side. A boss 112 that is rotatably fitted in a through hole 111 (see FIG. 9) formed in the side wall portion 12 (see FIG. 9) of the housing unit 5 is provided. Further, a boss 97 A that is inserted into the notch 113 (see FIGS. 9 and 10) is provided upright on the outer surface on the side wall 12 side of the outer peripheral edge of the mechanical arm 97. A groove 115 having a predetermined depth is formed on the inner side surface of the mechanical arm 97 along the center line.

Therefore, by inserting the other end side bent portion of the connecting shaft 96 into the groove 115 of the mechanical side arm 97, the mechanical side arm 97 is placed on the outer surface of the end edge portion on the central angle side of the mechanical side arm 97. It is attached to the other end side of the connecting shaft 96 so that the axial center of the boss 112 erected and the axial center of the connecting shaft 96 are substantially straight.

When the pretensioner unit 7 is attached to the housing unit 5 as will be described later, the boss 112 of the mechanical arm 97 is rotatably inserted into the through hole 105 formed in the side wall portion 12 (see FIG. 10). Further, the boss 97 A of the mechanical arm 97 is inserted into a notch 138 formed in the side wall portion 12 and is rotatably attached to the inside of the side wall portion 12.

[Pretensioner mechanism]
Next, the configuration and attachment of the pipe cylinder 42 constituting the pretensioner mechanism 17 will be described with reference to FIGS.
As shown in FIGS. 3 to 5, the pipe cylinder 42 is formed in a substantially L shape with a steel pipe material or the like. And the one end side (lower bending part in FIG. 3) is comprised so that the substantially cylindrical accommodating part 42A may be formed and the gas generating member 41 may be accommodated. The gas generating member 41 includes explosives, and is configured to ignite the explosives according to an ignition signal from a control unit (not shown) and generate gas by combustion of the gas generating agent.

Further, the other end side (the upper bent portion in FIG. 3) of the pipe cylinder 42 is formed with a piston housing portion 42B having a substantially rectangular cross section, and a notch portion 117 is formed at a portion facing the pinion gear body 33. 45, the pinion gear portion 55 of the pinion gear body 33 is configured to fit into the notch 117. Further, the upper end portion of the piston accommodating portion 42B is provided with an opening 118 that is cut out so as to be inclined obliquely outward from a substantially central portion in the width direction of both side surfaces abutting against the base plate 45 and the cover plate 53. Yes.

In addition, the pretensioner unit 7 is attached to the housing unit 5 on both sides of the piston storage portion 42B below the inclined portion 118A inclined to the outside of the opening 118 formed at the upper end portion, and the piston 47 A pair of opposed through-holes 121 into which the stopper pin 16 functioning as a retaining member can be inserted is formed.

Further, as shown in FIGS. 3 and 4, the first seal plate 43 is formed of a rubber material having excellent low temperature characteristics such as silicone rubber. The first seal plate 43 is formed in a substantially rectangular flat plate shape that can be inserted from the upper end side of the piston housing portion 42B, and has substantially the same shape as the gas pressure receiving side surface that receives the gas of the piston 47. The first seal plate 43 is opposed to a mounting recess 122 (see FIG. 6) having a circular cross section having a predetermined depth (for example, a depth of about 4 mm) formed on the gas pressure receiving side surface of the piston 47. In addition, a through hole 125 having a diameter substantially the same as the diameter of the mounting recess 122 is formed.

The second seal plate 44 is formed of a rubber material having excellent high temperature characteristics such as nitrile rubber. The second seal plate 44 is formed in a substantially rectangular flat plate shape that can be inserted from the upper end side of the piston accommodating portion 42 B, and has substantially the same shape as the gas pressure receiving side surface that receives the gas of the piston 47. Further, the second seal plate 44 is provided with a substantially cylindrical mounting convex portion 123 fitted into the mounting concave portion 122 at a position facing the mounting concave portion 122 formed on the gas pressure receiving side surface of the piston 47. .

The mounting convex portion 123 of the second seal plate 44 is formed at a predetermined height that can be inserted into the mounting concave portion 122 with the first seal plate 43 interposed therebetween after fitting into the through hole 125 of the first seal plate 43. Therefore, the second seal plate 44 is inserted into the mounting recess 122 with the first seal plate 43 interposed therebetween after the mounting protrusion 123 is inserted into the through-hole 125 of the first seal plate 43, and is attached to the gas pressure receiving side surface of the piston 47. It is attached. In addition, a gas vent hole 124 that communicates from the pressure receiving side surface that receives the gas of the second seal plate 44 along the axis is formed at the center of the mounting convex portion 123.

Further, as shown in FIGS. 3 to 7, the piston 47 is formed of a steel material or the like, has a substantially rectangular cross section that can be inserted from the upper end side of the piston accommodating portion 42B, and has an elongated shape as a whole. ing. A rack 47 A that meshes with the pinion gear portion 55 of the pinion gear body 33 is formed on the side surface of the piston 47 on the pinion gear body 33 side. Further, a stepped portion 126 capable of abutting against the stopper pin 16 is formed on the back surface of the front end portion (the upper end portion in FIGS. 3 and 5) of the rack 47A.

In addition, a pair of grooves 127 having a predetermined depth (for example, a depth of about 2 mm) are formed on both side surfaces of the rack 47A of the piston 47 from the upper edge of the step 126 to the cutting edge at the lower edge of the rack 47A. They are formed so as to face each other along the longitudinal direction of the piston 47 up to the facing position. In addition, a through hole 128 having a rectangular cross section that is long along the longitudinal direction of the piston 47 is formed at the lower end of the pair of grooves 127, and both side surface portions communicate with each other. Further, the mounting recess 122 formed on the pressure receiving side surface of the piston 47 and the through hole 128 are communicated with each other by a small communication hole 131 formed along the longitudinal direction of the piston 47.

Then, as shown in FIG. 5 and FIG. 8, the fitting convex portion 123 of the second seal plate 44 is fitted into the through hole 125 of the first sealing plate 43 and then fitted into the fitting concave portion 122 formed on the pressure receiving side surface of the piston 47. Then, the first seal plate 43 and the second seal plate 44 are attached to the gas pressure receiving side surface of the piston 47. Then, the first seal plate 43 and the second seal plate 44 are set to the back side, and the piston 47 is press-fitted from the upper end side of the piston housing portion 42B to the back side. Further, the gas vent hole 124 of the second seal plate 44 communicates with the through hole 128 via the communication hole 131 of the piston 47.

Accordingly, in this state, the first seal plate 43 and the second seal plate 44 are pressed by the pressure of the gas generated by the gas generating member 41, and the piston 47 moves to the upper end side opening 118 of the piston housing portion 42B. . After that, when the webbing 3 is pulled out again, the gas vent hole 124 of the second seal plate 44, the communication hole 131 of the piston 47, and the through hole when the piston 47 is lowered downward by the reverse rotation of the pinion gear body 33. The gas in the pipe cylinder 42 is released through 128, and the piston 47 is smoothly lowered.

Further, as shown in FIG. 5, in a normal state until the gas generating member 41 is operated, the piston 47 is retracted to the back side of the piston housing part 42B, and the tip of the rack 47A is not engaged with the pinion gear part 55. It is located to become. The base plate is inserted into the notches 117 of the piston housing part 42B configured in this way while the protruding parts 109 projecting outward from both side edges of the gear housing part 81 of the base block body 46 are fitted. The pipe cylinder 42 is disposed on the 45.

At this time, a rack retaining pin 133 having a substantially U-shaped cross-section standing on the gear housing portion 81 of the base block body 46 is inserted into the gear groove at the upper end of the rack 47A, and the vertical movement of the piston 47 is restricted. Is done. Further, the tip of the piston 47 is located in the vicinity of the pinion gear portion 55 of the pinion gear body 33 and is in a non-meshing state.

As a result, the piston accommodating portion 42B of the pipe cylinder 42 is separated from each of the ribs 134 having a substantially triangular cross-section standing on the side surface of the base block body 46 and the portion of the side edge of the base plate 45 facing the pinion gear body 33. Both side portions are supported by a back support portion 135 extending substantially at a right angle.

As shown in FIGS. 3 and 5, the back support portion 135 extends so as to be substantially the same height as the piston housing portion 42 B, and is located on the upper end side from the substantially central portion of the edge portion in the extending direction. A notch 136 having a predetermined width (for example, a width of about 8 mm) is formed with a predetermined depth (for example, about 4 mm). Further, a lower end edge portion of the back support portion 135 is extended by a predetermined length (for example, about 4 mm) in a substantially perpendicular outer direction, and a lower corner portion of the back support portion 135 is provided with a cover plate 53. A stepped portion 137 having a height substantially equal to the thickness is formed.

Further, as shown in FIGS. 3 to 5, through

holes

141, 142 through which the front end portion of the back support portion 135 can be inserted into the side end portion of the cover plate 53 facing the back support portion 135 of the base plate 45. Is formed. Moreover, the side edge part which opposes the outer surface of the backrest part 135 of each through-hole 141,142 is predetermined height (for example, about 3 mm height) to an inner side direction (left direction in FIG. 4). It is depressed. Thereby, when each edge part of the extending direction of the back support part 135 is inserted in each through-hole 141,142, the inner surface of each through-hole 141,142 becomes an outer surface of the back support part 135. It is comprised so that it may contact | abut reliably.

Then, in a state where the base block body 46, the forced lock mechanism 51, the pipe cylinder 42, and the like are arranged on the base plate 45, the positioning bosses 143 that protrude from the side surface portion on the cover plate 53 side of the base block body 46 are covered with the cover. The cover plate 53 is disposed on the upper side of the base block body 46, the forced lock mechanism 51, the pipe cylinder 42, and the like by being fitted into the positioning holes 144 of the plate 53. At the same time, the cylindrical support portion 56 of the pinion gear body 33 is fitted into the support hole 145 formed in the substantially central portion of the cover plate 53.

Further, the back support part 135 extending substantially at right angles from the side edge part of the base plate 45 is inserted into the through

holes

141 and 142 formed in the side edge part facing the back support part 135 of the cover plate 53. To do. An elastic locking piece 46C that extends from the outer side surface of the base block body 46 toward the cover plate 53 and is elastically deformable in the outer direction, and a cover from the upper side surface of the base block body 46. Elastic locking pieces 46 D that extend toward the plate 53 side and are formed so as to be elastically deformable in the outward direction are respectively locked to the side end portions of the cover plate 53.

Then, a screw 88 is inserted into a through hole 157 formed at a position facing the through hole 89 of the base block body 46 of the cover plate 53 and fastened to a screw hole 158 formed by burring processing of the base plate 45.

Thus, the cover plate 53 is disposed and fixed to the base block body 46, and the pipe cylinder 42 is attached between the cover plate 53 and the base plate 45. Further, the support portion 56 formed at the end of the pinion gear body 33 is rotatably supported by the support hole 145 of the cover plate 53. Accordingly, the base end portion of the boss portion 58 formed at both ends of the pinion gear body 33 and the support portion 56 are rotatably supported by the through hole 76 of the base plate 45 and the support hole 145 of the cover plate 53, respectively.

Further, each through hole 121 of the pipe cylinder 42, a through hole 147 formed at a position facing each through hole 121 of the cover plate 53, and a through hole formed at a position facing each through hole 121 of the base plate 45. 148 is arranged on the same axis. As a result, as shown in FIG. 2, the stopper pin 16 formed of steel or the like is inserted into the through hole 148 of the base plate 45, the through holes 121 of the pipe cylinder 42, and the cover plate 53 from the pinning portion 14 B side of the housing 11. It can be inserted into the through hole 147 and fixed by the push nut 18.

Therefore, the pipe cylinder 42 is sandwiched between the cover plate 53 and the base plate 45, and both side surfaces are sandwiched between the base block body 46 and the backrest 135. Further, the first seal plate 43 and the second seal plate 44 are pressed by the pressure of the gas generated by the gas generating member 41, and the piston 47 is opened at the upper end side of the piston housing portion 42B (the upper end portion in FIG. 5). The stepped portion 126 of the piston 47 can be brought into contact with the stopper pin 16 inserted through each through-hole 121 and stopped.

Further, the opening 118 on the upper end side of the piston accommodating portion 42B is a first extending portion that extends from the upper end edge of the cover plate 53 to the base plate 45 side at a substantially half width with respect to the piston accommodating portion 42B. The flat portion 118B perpendicular to the axial direction of the piston accommodating portion 42B of the opening 118 is covered by 151. In addition, the inclined portion 118A is covered by the second extending portion 152 that extends obliquely outward from the side end edge of the opening 118 of the first extending portion 151 on the inclined portion 118A side. Is called. Further, an end edge portion of the first extension portion 151 on the base block body 46 side is extended by a predetermined length (for example, a length of about 4 mm) in the lower right direction.

Further, the base plate 45 is bent and extended with a predetermined width (for example, a width of about 3 mm) so as to face the outer end edge in the extending direction of the second extending portion 152 of the cover plate 53. The pressed portion 155 is provided. The pressing portion 155 has a predetermined width (for example, a width of about 3 mm) so as to be parallel to the second extending portion 152 from a position facing the through hole 148 at the upper end edge of the base plate 45. It extends a predetermined length (for example, about 8 mm) and is bent at a right angle so as to face the outer end edge in the extending direction of the second extending portion 152 from a substantially central portion.

Thereby, the opening 118 on the upper end side of the piston housing part 42B is covered with the first extending part 151 and the second extending part 152. Further, the outer end edge portion in the extending direction of the second extending portion 152 of the cover plate 53 faces the side surface portion of the pressing portion 155 of the base plate 45.

[Schematic configuration of housing unit]
Next, a schematic configuration of the housing unit 5 will be described with reference to FIGS. 9 and 10.
FIG. 9 is an exploded perspective view of the housing unit 5. FIG. 10 is a side view of the seatbelt retractor 1 with the lock unit 9 removed.
As shown in FIG. 9, the housing unit 5 includes a housing 11, a bracket 161, a protector 163, a pawl 37, and a pawl rivet 165.

The housing 11 is formed of a steel material or the like in a substantially U shape in plan view, and a through hole 166 into which the tip of the ratchet gear 26 of the winding drum unit 6 is inserted is formed in the side wall portion 12 on the back side. Has been. Further, a notch 113 is formed in a portion of the through hole 166 facing the obliquely lower pawl 37 so that the pawl 37 rotates smoothly. A through hole 168 for rotatably mounting the pawl 37 is formed on the lateral side of the notch 113.

Further, a semicircular guide portion 169 is formed on the concentric circle of the through hole 168 at a portion where the pawl 37 of the cutout portion 113 abuts. On the other hand, the portion of the pawl 37 that slides in contact with the guide portion 169 has a height substantially equal to the thickness dimension of the side wall portion 12 and a step that is recessed in an arc shape having the same curvature radius as the side edge of the guide portion 169. The part 37B is formed slightly higher than the thickness dimension of the side wall part 12. As shown in FIG. 10, a guide pin 37 A that is inserted into a guide groove (not shown) of a clutch (not shown) that constitutes the lock unit 9 is erected at the tip of the outer side surface of the pawl 37. ing.

Further, as shown in FIG. 9, the

side plate portions

13 and 14 facing each other are extended from both side edge portions of the side wall portion 12. In addition, an opening is formed in the central portion of each of the

side plate portions

13 and 14 to reduce the weight and improve the efficiency of attaching the webbing 3. Further, upper and lower edge portions of the

side plate portions

13 and 14 are formed with screwing

portions

13A, 13B, and 14A and pinning portions 14B that extend in a substantially right-angle inner direction with a predetermined width.

Moreover, each screwing

part

13A, 13B, 14A is formed with each screw hole 171 by which each screw 15 is screwed by burring, and the screwing part 14B has a through-hole 172 through which the stopper pin 16 is inserted. Is formed. Accordingly, as shown in FIGS. 2 to 4, each screw 15 is inserted from each through hole 185 of the cover plate 53 to each through hole 186 of the base plate 45 and is screwed to each screw hole 171.

In addition, the bracket 161 attached to each upper end edge of the side plate portion 13 by a rivet 162 is formed of a steel material or the like, and webbing is performed on an extended portion that extends substantially inward from the upper end edge of the side plate portion 13. A horizontally long through-hole 173 from which 3 is pulled out is formed, and a horizontally long frame-shaped protector 163 formed of a synthetic resin such as nylon is fitted therein. Further, a bolt insertion hole 178 into which a bolt 176 (see FIG. 10) is inserted when being attached to a fastening piece 175 (see FIG. 10) of the vehicle is formed in the lower end portion of the side plate portion 13.

Further, as shown in FIGS. 9 and 10, the pawl 37 formed of steel or the like is rotatably inserted into the through hole 168 from the outside of the side wall portion 12 with the stepped portion 37 B abutting against the guide portion 169. The pawl rivet 165 is rotatably fixed. Accordingly, the side surface of the pawl 37 and the side surface of the ratchet gear 26 are positioned so as to be substantially flush with the outer surface of the side wall portion 12.

Further, as shown in FIG. 10, when the pretensioner unit 7 is attached to the housing unit 5 by the screws 15, the stopper pins 16, and the push nuts 18, the pretensioner unit 7 is attached to the bent portion on the other end side of the connecting shaft 96. The boss 112 of the mechanical arm 97 is rotatably fitted in a through hole 111 formed in the side wall portion 12 and is positioned in the vicinity of the lower side surface portion of the pawl 37 located in the notch portion 113. . Further, a boss 97 A standing on the outer side surface of the mechanical arm 97 is inserted into the notch 113. Further, the pawl 37 is normally close to the mechanical arm 97 and is not engaged with the ratchet gear 26.

Further, below the pawl 37 and the mechanical arm 97 attached to the side wall portion 12, a predetermined width from a position that is a predetermined height above the lower end surface of the side wall portion 12 (for example, a position that is about 10 mm above). (For example, the width is about 10 mm), and the arm protection fold is bent at a substantially right angle inward (toward the front in FIG. 7) so as to face the pawl 37 and the mechanical arm 97. A curved portion 180 is provided. That is, below the pawl 37 and the mechanical side arm 97 attached to the side wall portion 12, a predetermined length (for example, a length of about 10 mm) is set at a substantially right angle so as to face the mechanical side arm 97 with a predetermined width. An arm protection bent portion 180 extending inward is provided.

In addition, a laterally long opening 181 is formed in a portion of the side wall portion 13 that faces the connecting shaft 96, and faces the entire length of the connecting shaft 96, and is substantially inward from the lower edge of the opening 181. A shaft protecting bent portion 182 that is bent at a right angle is provided. Further, the end edge portion on the guide drum 21 side of the shaft protecting bent portion 182 extends so as to be inside the connecting shaft 96 facing the side wall portion 13. A bolt insertion hole 178 is formed below the shaft protecting bent portion 182, and a bolt 176 is inserted into the bolt insertion hole 178 and fixed to a vehicle fastening piece 175 by a nut 177.

[Description of forced lock mechanism and pawl operation]
Next, the operations of the forced lock mechanism 51 and the pawl 37 that are activated by the operation of the gas generation member 41 of the pretensioner mechanism 17 in an emergency such as a vehicle collision will be described with reference to FIGS. 11 and 12. FIG. 11 is an explanatory view showing a state where the piston 47 is moved by the operation of the gas generating member 41 of the pretensioner mechanism 17 and the lower end portion of the rotation lever 93 is disengaged from the tip end portion of the gear side arm 94. FIG. 12 is an explanatory view showing the operation of the pawl 37 corresponding to FIG.

As shown in FIG. 11, when the gas generation member 41 of the pretensioner mechanism 17 is activated in an emergency such as a vehicle collision, the piston of the pipe cylinder 42 is stored by the pressure of the gas generated by the gas generation member 41. The first seal plate 43 and the second seal plate 44 in the portion 42B are pressed. As a result, the piston 47 shears the rack stop pin 133 from the normal state shown in FIG. 5 and moves it upward (in the direction of arrow X1), and moves the pinion gear body 33 counterclockwise in the front view (in the direction of arrow X2). Rotate to). Further, since the upper end portion of the rotation lever 93 is further pushed by the push block 92 pushed by the block urging spring 92 A, the lower end portion of the rotation lever 93 is disengaged from the tip end portion of the gear side arm 94.

Therefore, the gear side arm 94 is pressed outward by the biasing spring 95 and rotates in the counterclockwise direction when viewed from the front (in the direction of the arrow X3). The push block 92 is pressed outward by the block biasing spring 92A and is maintained in a state of being separated from the pinion gear portion 55 of the pinion gear body 33, and the upper end portion of the rotary lever 93 is abutted against the inner wall surface of the recess 91. Keep in contact.

Also, as shown in FIG. 12, when the lower end portion of the rotation lever 93 is disengaged from the tip end portion of the gear side arm 94, the gear side arm 94 is counterclockwise when viewed from the front (the direction of the arrow X3). ), The connecting shaft 96 in which the one-end bent portion is inserted into the groove portion 105 of the gear side arm 94 also rotates counterclockwise (in the direction of the arrow X3) around the axis. To do.

For this reason, the mechanical side arm 97 has the other end side bent portion of the connecting shaft 96 inserted into the groove 115, and therefore, when the gear side arm 94 rotates, it is counterclockwise when viewed from the front (in the direction of arrow X8). And the pawl 37 is engaged with the ratchet gear portion 26A of the ratchet gear 26. The pawl 37 and the ratchet gear portion 26A of the ratchet gear 26 are configured to mesh with each other so as to prevent the winding drum unit 6 from rotating in the webbing 3 pull-out direction and to allow rotation in the webbing 3 winding direction. ing.

Therefore, when the pawl 37 and the ratchet gear portion 26A of the ratchet gear 26 are engaged, a locking operation is performed to prevent the winding drum unit 6 from rotating in the webbing 3 pull-out direction, and in the webbing 3 winding direction. Is allowed to rotate. Note that before the clutch mechanism 48 and the pinion gear body 33 start to rotate together, the pawl 37 is in a state in which the winding drum unit 6 can be prevented from rotating in the direction in which the webbing 3 is pulled out.

The gas generated from the gas generating member 41 presses the pressure receiving side surfaces of the first seal plate 43 and the second seal plate 44 and is formed on the pressure receiving side surface of the piston 47 from the gas vent hole 124 of the second seal plate 44. It flows out in the directions of the arrows X4 to X7 through the communication holes 131 that allow the mounting recess 122 and the through hole 128 to communicate with each other.

The first extending portion 151 and the second extending portion 152 of the cover plate 53 that cover the opening 118 of the piston accommodating portion 42B are pressed outward by the gas pressure, but the second extending portion 152 Since the outer edge in the extending direction is pressed against the pressing portion 155 of the base plate 45, the gas is discharged from the gap between the opening 118 and the first extending portion 151 and the second extending portion 152. The

Further, after the operation of the pretensioner mechanism 17, after the rotation of the pinion gear body 33 is stopped, the state where the lower end portion of the rotation lever 93 is disengaged from the distal end portion of the gear side arm 94 is maintained as shown in FIG. The That is, after the operation of the pretensioner mechanism 17, the engagement between the pawl 37 and the ratchet gear portion 26A of the ratchet gear 26 is maintained. For this reason, the ratchet gear 26 and the wire plate 25 of the winding drum unit 6 are prevented from rotating in the direction in which the webbing 3 is pulled out.

Here, an example in which the pull-in performance of the webbing 3 is measured by changing the materials of the first seal plate 43 and the second seal plate 44 will be described with reference to FIG. FIG. 13 is a drawing performance comparison table 191 showing an example of comparison results comparing the drawing performance of the webbing 3.

As shown in FIG. 13, the pull-in performance comparison table 191 includes “No.” representing the experiment number, “Material” representing the respective materials of the first seal plate 43 and the second seal plate 44, and “JIS K 7215”. "Hardness (HDA)" representing the hardness of the first seal plate 43 and the second seal plate 44 measured on the basis of the "Type A" standard, "Structure" representing the seal structure, and retraction performance of the webbing 3 It is comprised from "the pulling-in performance determination" showing the determination result.

In addition, the comparison of the drawing-in performance of the webbing 3 was performed according to the criterion shown below the drawing-in performance comparison table 191. In other words, the amount of reduction of the pull-in amount is based on the pull-in amount (for example, the pull-in amount is 110 mm) of the webbing 3 in the normal temperature environment of the experiment number “No. 1” (for example, the outside air temperature is about 20 ° C.). When it is less than 15% (for example, when the reduction amount of the pull-in amount is less than 16.5 mm), the determination result is represented by “double circle”.

Further, when the decrease in the pull-in amount is 15% or more and less than 30% based on the pull-in amount of the webbing 3 in the normal temperature environment of the experiment number “No. 1” (for example, the decrease in the pull-in amount is 16.5 mm or more and 33 mm). The determination result is expressed as “single circle”. Further, when the decrease in the pull-in amount is 30% or more and less than 45% based on the pull-in amount of the webbing 3 in the normal temperature environment of the experiment number “No. 1” (for example, the decrease in the pull-in amount is 33 mm or more and 49.5 mm). The determination result is represented by “triangle”. Further, when the decrease in the pull-in amount is 45% or more on the basis of the pull-in amount of the webbing 3 in the normal temperature environment of the experiment number “No. 1” (for example, the decrease in the pull-in amount is 49.5 mm or more). ), And the determination result is represented by “×”.

For example, as the “material” of the experiment number “No. 1”, the first seal plate 43 and the second seal plate 44 are both formed of nitrile rubber (NBR). The hardness of the experiment number “No. 1” is that the hardness of the first seal plate 43 and the second seal plate 44 are both “HDA 90”. In addition, in the “configuration” of the experiment number “No. 1”, the first seal plate 43 and the second seal plate 44 formed of nitrile rubber were overlapped and attached to the pressure receiving side end face of the piston 47 (see FIG. 8).

The determination result in the “normal temperature environment” (for example, the outside air temperature is 20 ° C.) of the experiment number “No. 1” is “double circle”, that is, the pulling amount of the webbing 3 is the reference pulling amount (for example, the reference pulling amount). The pull-in amount is 110 mm.). In addition, the determination result in the “low temperature environment” (for example, the outside air temperature is −30 ° C.) is “x”, that is, the pulling amount of the webbing 3 is reduced by 45% or more with respect to the reference pulling amount. The determination result in the “high temperature environment” (for example, the outside air temperature is 50 ° C.) is “single circle”, that is, the pulling amount of the webbing 3 is a decrease of 15% or more and less than 30% with respect to the reference pulling amount. there were.

Further, as the “material” of the experiment number “No. 2”, the first seal plate 43 and the second seal plate 44 are both formed of silicone rubber. In addition, the hardness of the experiment number “No. 2” is the hardness “HDA 90” for both the first seal plate 43 and the second seal plate 44. In the “configuration” of the experiment number “No. 2”, the first seal plate 43 and the second seal plate 44 formed of silicone rubber were overlapped and attached to the pressure receiving side end face of the piston 47 (see FIG. 8).

The determination result in the “normal temperature environment” (for example, the outside air temperature is 20 ° C.) of the experiment number “No. 2” is “single circle”, that is, the pull-in amount of the webbing 3 is 15 with respect to the reference pull-in amount. % Or more and less than 30%. In addition, the determination result in the “low temperature environment” (for example, the outside temperature is −30 ° C.) is “double circle”, that is, the pulling amount of the webbing 3 is less than 15% of the reference pulling amount. It was. The determination result in the “high temperature environment” (for example, the outside air temperature is 50 ° C.) is “x”, that is, the pull-in amount of the webbing 3 is reduced by 45% or more with respect to the reference pull-in amount.

In addition, regarding the “material” of the experiment number “No. 3”, the first seal plate 43 was formed of silicone rubber, and the second seal plate 44 was formed of nitrile rubber (NBR). Further, the hardness of the experiment number “No. 3” is that the hardness of both the first seal plate 43 and the second seal plate 44 is “HDA 90”. In addition, in the “configuration” of the experiment number “No. 3”, the first seal plate 43 formed of silicone rubber and the second seal plate 44 formed of nitrile rubber are overlapped and attached to the pressure receiving side end surface of the piston 47. (See FIG. 8).

The determination result in the “normal temperature environment” (for example, the outside air temperature is 20 ° C.) of the experiment number “No. 3” is “double circle”, that is, the pull-in amount of the webbing 3 is relative to the reference pull-in amount. The decrease was less than 15%. In addition, the determination result in the “low temperature environment” (for example, the outside temperature is −30 ° C.) is “single circle”, that is, the pulling amount of the webbing 3 is reduced by 15% or more and less than 30% with respect to the reference pulling amount. Met. The determination result in the “high temperature environment” (for example, the outside air temperature is 50 ° C.) is “single circle”, that is, the pulling amount of the webbing 3 is a decrease of 15% or more and less than 30% with respect to the reference pulling amount. there were.

Therefore, when the first seal plate 43 made of silicone rubber and the second seal plate 44 made of nitrile rubber are overlapped and attached to the pressure receiving side end face of the piston 47, the "normal temperature environment" and "high temperature environment" In addition to securing the pull-in amount of the webbing 3, the pull-in amount of the webbing 3 in the “low temperature environment” is also attached to the pressure receiving side end surface of the piston 47 by overlapping the first seal plate 43 and the second seal plate 44 formed of nitrile rubber. It is improved and secured than the case.

Here, the winding drum unit 6 is an example of a winding drum. The pretensioner mechanism 17 is an example of a pretensioner mechanism unit. The pipe cylinder 42 is an example of a cylinder. The first seal plate 43 is an example of a first seal member. The second seal plate 44 is an example of a second seal member.

As described in detail above, in the seatbelt retractor 1 according to the present embodiment, the gas pressure side end of the piston 47 movably accommodated in the pipe cylinder 42 of the pretensioner mechanism 17 is formed of silicone rubber. The first seal plate 43 and the second seal plate 44 formed of nitrile rubber are attached so as to overlap each other, and the gap between the piston 47 and the inner wall of the pipe cylinder 42 is sealed. In addition, the first seal plate 43 formed of silicone rubber having excellent low temperature characteristics is disposed between the pressure-receiving side end face of the piston 47 and the second seal plate 44 formed of nitrile rubber.

As a result, of the first seal plate 43 and the second seal plate 44, the second seal plate 44 in which the high-temperature gas generated from the gas generating member 41 directly contacts the pressure receiving side surface is formed of nitrile rubber having excellent high-temperature characteristics. Thus, it is possible to secure the pull-in performance of the webbing 3 of the pretensioner mechanism 17 in a wide area from a low temperature environment to a high temperature environment while protecting the first seal plate 43 formed of silicone rubber from high temperature gas. it can.

Further, the first seal plate 43 formed of silicone rubber having excellent low temperature characteristics is disposed between the pressure-receiving side end surface of the piston 47 and the second seal plate 44 formed of nitrile rubber. It is possible to ensure the retraction performance of the webbing 3 of the pretensioner mechanism 17 at.

Further, the mounting convex portion 123 of the second seal plate 44 is inserted into the through-hole 125 of the first seal plate 43, and the mounting convex portion 123 is further attached to the pressure receiving side end surface of the piston 47 with a predetermined depth. By fitting into the recess 122, the flat plate-like first seal plate 43 and the second seal plate 44 can be overlapped and integrally assembled to the pressure-receiving side end surface of the piston 47, thereby improving the mounting work efficiency. be able to.

In addition, since the first seal plate 43 and the second seal plate 44 are flat plate members having substantially the same shape as the end surface of the piston 47 on the gas pressure receiving side, the piston 47 to which the

seal members

43 and 44 are attached is used as the pressure receiving surface. When inserting into the pipe cylinder 42 from the side, it is possible to prevent the

seal members

43 and 44 from being twisted, displaced, detached, etc. due to friction with the inner wall of the pipe cylinder 42. As a result, the deterioration of the sealing performance due to poor mounting of the sealing

members

43 and 44 is surely prevented, and the pull-in performance of the webbing 3 of the pretensioner mechanism 17 is more reliably ensured in a wide area from a low temperature environment to a high temperature environment. It becomes possible to do.

Further, the gas vent hole 124 of the second seal plate 44 and the communication hole 131 of the piston 44 communicate with each other. Thus, when the seat belt retractor 1 is provided with an energy absorbing mechanism that pulls out the webbing 3 and reduces the impact on the occupant when the pulling force acting on the webbing 3 exceeds a predetermined value, the pretensioner mechanism 17 is activated. Even if the piston 47 moves to the normal position, the residual gas remaining in the cylinder between the second seal plate 44 and the gas generating member 41 is released to the outside through the gas vent hole 124 and the communication hole 131. It is possible to prevent the residual gas pressure from interfering with the operation of the energy absorption mechanism.

Further, since the mounting convex portion 123 of the second seal plate 44 is hollow, it can be easily bent and can be easily fitted into the mounting concave portion 122 of the piston 47, so that the first sealing plate 43 and the piston 47 of the second sealing plate 44 can be fitted. The mounting work efficiency can be further improved.

Note that the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the scope of the present invention.

[Other embodiment 1]
(A) For example, the seatbelt retractor 201 according to another embodiment 1 has substantially the same configuration as the seatbelt retractor 1 described above, but instead of the first seal plate 43 and the second seal plate 44, FIG. The first seal plate 203 and the second seal plate 204 may be attached to the pressure-receiving side end face of the piston 47.

Here, the first seal plate 203 and the second seal plate 204 will be described with reference to FIGS. FIG. 14 is a perspective view showing an example of the first seal plate 203 and the second seal plate 204. FIG. 15 is an enlarged cross-sectional view of the main part of the pipe cylinder 42 showing an example in which the first seal plate 203 and the second seal plate 204 are attached to the piston 47. In the following description, the same reference numerals as those of the first seal plate 43 and the second seal plate 44 according to the embodiment shown in FIGS. 1 to 13 denote the same components as those of the first seal plate 43 according to the embodiment. 2 shows the same or corresponding part as the configuration of the seal plate 44.

As shown in FIG. 14, the second seal plate 204 has substantially the same configuration as the second seal plate 44, but a substantially cylindrical positioning protrusion 205 is erected on the surface that contacts the first seal plate 203. ing. The height dimension of the positioning protrusion 205 is equal to the thickness of the first seal plate 203 or slightly smaller than the thickness. On the other hand, the first seal plate 203 is positioned at a position facing the positioning projection 205 of the second seal plate 204 when the mounting convex portion 123 of the second seal plate 204 is fitted into the through hole 125. A positioning hole 206 having a diameter substantially equal to the diameter of the first through hole is formed therethrough.

Then, as shown in FIG. 15, first, the mounting convex portion 123 of the second seal plate 204 is fitted into the through hole 125 of the first seal plate 203, and the positioning protrusion 205 of the second seal plate 204 is inserted into the first seal plate. It fits into the positioning hole 206 of 203. Thereafter, the mounting convex portion 123 of the second seal plate 204 is fitted into the mounting concave portion 122 formed on the pressure receiving side surface of the piston 47, and the first seal plate 203 and the second seal plate 204 are attached to the gas pressure receiving side surface of the piston 47. .

Then, the first seal plate 203 and the second seal plate 204 are set to the back side, and the piston 47 is press-fitted from the upper end side of the piston housing portion 42B to the back side. Further, the gas vent hole 124 of the second seal plate 204 communicates with the through hole 128 via the communication hole 131 of the piston 47.

Therefore, in this state, the first seal plate 203 and the second seal plate 204 are pressed by the pressure of the gas generated by the gas generating member 41, and the piston 47 moves to the upper end side opening 118 of the piston housing portion 42B. . After that, when the webbing 3 is pulled out again, the gas vent hole 124 of the second seal plate 204, the communication hole 131 of the piston 47, and the through hole when the piston 47 is lowered downward by the reverse rotation of the pinion gear body 33. The gas in the pipe cylinder 42 is released through 128, and the piston 47 is smoothly lowered.

Further, the first seal plate 203 is attached to the second seal plate 204 by fitting the mounting projection 123 and the positioning protrusion 205 of the second seal plate 204 into the through hole 125 and the positioning hole 206 of the first seal plate 203. The piston 47 can be attached to the end face on the gas pressure receiving side of the piston 47 in a surely positioned state.

Thereby, when the piston 47 to which the

seal plates

203 and 204 are attached is inserted into the pipe cylinder 42 from the pressure receiving surface side, the twist and displacement due to friction with the inner wall of the pipe cylinder 42 of the

seal plates

203 and 204, Detachment can be reliably prevented. Therefore, it is possible to surely prevent the sealing performance from being deteriorated due to poor mounting of the

seal plates

203 and 204, and to further ensure the pull-in performance of the webbing 3 of the pretensioner mechanism 17 in a wide area from a low temperature environment to a high temperature environment. It becomes possible.

[Other embodiment 2]
(B) For example, the seatbelt retractor 211 according to another embodiment 2 has substantially the same configuration as the seatbelt retractor 201 according to other embodiment 1 described above. However, it is different in that a piston 213 shown in FIG. Further, the second seal plate 214 is different from the second seal plate 204 in that a second seal plate 214 shown in FIG.

Here, the piston 213, the first seal plate 203, and the second seal plate 214 will be described with reference to FIGS. FIG. 16 is a perspective view of the piston 213 viewed from the pressure receiving surface side. FIG. 17 is an enlarged cross-sectional view of the main part of the pipe cylinder 42 showing an example in which the first seal plate 203 and the second seal plate 214 are attached to the piston 213. In the following description, the same reference numerals as those in FIG. 1 to FIG. 15 indicate the same or corresponding parts as those in FIG. 1 to FIG.

First, as shown in FIG. 17, the second seal plate 214 has substantially the same configuration as the second seal plate 204 according to the other embodiment 1, but instead of the positioning protrusion 205, a substantially cylindrical positioning protrusion 215. Is erected on the surface in contact with the first seal plate 203. The diameter of the positioning protrusion 215 is formed to be approximately equal to the diameter of the positioning hole 206 of the first seal plate 203. The height of the positioning protrusion 215 is formed so as to protrude a predetermined height (for example, about 2 mm in height) when the positioning protrusion 215 is fitted into the positioning hole 206 of the first seal plate 203. Has been.

As shown in FIG. 16, the piston 213 has substantially the same configuration as the piston 47, but the mounting recess 122 is formed on the pressure receiving side end surface at a position facing the mounting projection 123 of the second seal plate 214. In addition, a positioning recess 216 having the same diameter as the positioning projection 215 is formed at a position facing the positioning projection 215 of the second seal plate 214. The depth dimension of the positioning recess 216 is formed to be slightly deeper than the height dimension at which the positioning projection 215 protrudes from the first seal plate 203.

Then, as shown in FIG. 17, first, the mounting protrusion 123 of the second seal plate 214 is fitted into the through hole 125 of the first seal plate 203, and the positioning protrusion 215 of the second seal plate 214 is inserted into the first seal plate. It fits into the positioning hole 206 of 203. Thereafter, the mounting convex portion 123 of the second seal plate 214 is fitted into the mounting concave portion 122 formed on the pressure receiving side surface of the piston 47, and the positioning projection 215 is fitted into the positioning concave portion 216, so that the first seal plate 203 and the second sealing plate The seal plate 214 is attached to the gas pressure receiving side surface of the piston 213.

Then, the first seal plate 203 and the second seal plate 214 are set to the back side, and the piston 213 is press-fitted from the upper end side of the piston housing portion 42B to the back side. Further, the gas vent hole 124 of the second seal plate 214 communicates with the through hole 128 through the communication hole 131 of the piston 213.

Therefore, in this state, the first seal plate 203 and the second seal plate 214 are pressed by the pressure of the gas generated by the gas generating member 41, and the piston 213 moves to the upper end side opening 118 of the piston housing portion 42B. . Thereafter, when the webbing 3 is pulled out again, when the piston 213 descends downward due to the reverse rotation of the pinion gear body 33, the gas vent hole 124 of the second seal plate 214, the communication hole 131 of the piston 213, and the through hole The gas in the pipe cylinder 42 is released through 128, and the piston 213 is smoothly lowered.

Further, the first seal plate 203 is attached to the second seal plate 204 by fitting the mounting protrusion 123 and the positioning protrusion 215 of the second seal plate 214 into the through hole 125 and the positioning hole 206 of the first seal plate 203. It can be attached to the end surface of the piston 213 on the gas pressure receiving side in a reliably positioned state. Further, by inserting the positioning projection 215 of the second seal plate 214 into the positioning recess 216 of the piston 213, the rotation of the

seal plates

203 and 214 with respect to the piston 213 can be reliably prevented.

Thereby, when the piston 213 to which each

seal plate

203, 214 is attached is inserted into the pipe cylinder 42 from the pressure receiving surface side, the twist, displacement due to friction with the inner wall of the pipe cylinder 42 of each

seal plate

203, 214, Detachment can be reliably prevented. Accordingly, it is possible to surely prevent the sealing performance from being deteriorated due to poor mounting of the

seal plates

203 and 214, and to further ensure the retraction performance of the webbing 3 of the pretensioner mechanism 17 in a wide area from a low temperature environment to a high temperature environment. It becomes possible.

[Other embodiment 3]
(C) For example, the seatbelt retractor 221 according to another embodiment 3 has substantially the same configuration as the seatbelt retractor 1, but instead of the first seal plate 43, the second seal plate 44, and the piston 47. The first seal member 223, the second seal member 224, and the piston 225 shown in FIG. 18 may be mounted in the pipe cylinder 42.

Here, the first seal member 223, the second seal member 224, and the piston 225 will be described with reference to FIG. FIG. 18 is an enlarged cross-sectional view of a main part of a pipe cylinder showing an example in which a first seal member and a second seal member formed in a frame shape are attached to a piston. In the following description, the same reference numerals as those of the first seal plate 43, the second seal plate 44, and the piston 47 according to the embodiment shown in FIGS. 1 to 13 denote the first seal plate according to the embodiment. 43, the second seal plate 44, and the piston 47 are shown in the same or corresponding configuration.

As shown in FIG. 18, the piston 225 has substantially the same configuration as the piston 47 according to the embodiment. However, a seal attachment groove 226 having a predetermined depth (for example, a depth of about 2 mm) is formed on the side surface portion of the piston 225 in the vicinity of the pressure-receiving side end surface. The width dimension of the piston 225 in the longitudinal direction of the seal mounting groove 226 is formed to be approximately equal to the total thickness of the first seal member 223 and the second seal member 224. Further, the pressure receiving side end surface of the piston 225 and the through hole 128 are communicated with each other by a small communication hole 227 formed along the longitudinal direction of the piston 225.

The first seal member 223 is formed of a silicone rubber having a hardness of “HDA 90” in a frame shape, and has an inner peripheral surface smaller than the cross section of the seal attachment groove 226 of the piston 225. Fitted. Accordingly, the first seal member 223 is attached to the through hole 128 side of the seal attachment groove 226 so as to seal the gap between the piston 225 and the inner wall of the pipe cylinder 42.

The second seal member 224 is formed of a nitrile rubber having a hardness of “HDA 90” in a frame shape, and has an inner peripheral surface smaller than the cross section of the seal attachment groove 226 of the piston 225. Fitted. Therefore, the second seal member 224 is attached to the pressure receiving side of the seal attachment groove 226 so as to seal the gap between the piston 225 and the inner wall of the pipe cylinder 42.

As a result, of the first seal member 223 and the second seal member 224, the second seal member 224 in which the high-temperature gas generated from the gas generating member 41 directly contacts the pressure receiving side surface is formed of nitrile rubber having excellent high-temperature characteristics. Accordingly, it is possible to secure the pull-in performance of the webbing 3 of the pretensioner mechanism 17 in a wide area from a low temperature environment to a high temperature environment while protecting the first seal member 223 formed of silicone rubber from high temperature gas. it can.

Claims

A winding drum for winding and storing the webbing;
A housing that rotatably supports the winding drum;
A pretensioner mechanism for winding the webbing by rotating the winding drum in a winding direction in an emergency such as a vehicle collision;
In the seat belt retractor with
The pretensioner mechanism is
A gas generating member that generates gas;
A long cylindrical cylinder to which the gas generating member is attached at one end;
A piston that is movably accommodated in the cylinder and is driven to be pressed by the pressure of gas generated from the gas generating member to rotate the winding drum in the winding direction;
A plurality of seal members attached to overlap the gas pressure side end of the piston and sealing a gap between the piston and the inner wall of the cylinder;
With
The retractor for a seat belt, wherein the plurality of seal members include at least two types of seal members having different environmental resistances.
The seat belt retractor according to claim 1, wherein the plurality of seal members include a seal member formed of silicone rubber and a seal member formed of nitrile rubber.
The piston has a mounting recess of a predetermined depth formed on the end surface on the gas pressure receiving side,
The plurality of seal members are:
A first seal member having a through hole formed at a position facing the mounting recess and being in contact with the end surface by a flat plate member having substantially the same shape as the end surface on the gas pressure receiving side of the piston;
A second seal member having a mounting convex portion erected at a position facing the mounting concave portion, in a flat plate member having substantially the same shape as the end surface of the piston on the gas pressure receiving side;
Have
2. The second seal member, wherein the mounting convex portion is inserted into the through hole of the first sealing member and is fitted into the mounting concave portion of the piston to be attached to the piston. The seatbelt retractor according to claim 2.
The second seal member has a vent hole formed so as to penetrate the mounting convex portion in the thickness direction,
The retractor for a seat belt according to claim 3, wherein the piston has a communication hole formed so as to penetrate from the mounting recess along the moving direction of the piston.
The first seal member is formed of silicone rubber;
The retractor for a seat belt according to claim 3 or 4, wherein the second seal member is made of nitrile rubber.