JP4863284B2 - Pretensioner and seat belt device - Google Patents

Description

  The present invention relates to a pretensioner and a seat belt device for restraining an occupant by a seat belt by pulling a seat belt buckle when the vehicle is suddenly decelerated.

  Conventionally, a seat belt device for restraining an occupant is provided in a vehicle seat to prevent the occupant from jumping forward due to inertial force when the vehicle suddenly stops or an impact such as a collision occurs. . Such a seat belt device does not restrain the occupant's movement during normal operation, and locks the seat belt retracting shaft only when a vehicle impact occurs to prevent further extension of the seat belt. It is customary to have a locking retractor (hereinafter abbreviated as ELR). The ELR locks the take-up shaft in a very short time when a deceleration greater than a predetermined value is detected, so that the seat belt is not further drawn.

  However, when the seat belt in a state where the occupant is restrained is loosely wound around the take-up shaft with the one that only locks the take-up shaft as in the ELR described above, even if the take-up shaft is locked, The seat belt will be paid out to some extent. Further, even if the seat belt is not loosely wound, the seat belt is unwound after the deceleration of a predetermined value or more is detected until the winding shaft is locked.

  Therefore, when a predetermined deceleration is detected as a device that cancels out the seat belt unwinding due to the time difference until the seat belt loosens and the winding shaft is locked, the seat belt buckle is used. A pretensioner that is retracted is known (for example, see Patent Document 1).

The pretensioner described in Patent Document 1 includes a wire having one end connected to a seat belt buckle and the other end fixed to a piston in the cylinder, and a housing that penetrates the wire and holds the cylinder. When deceleration of the vehicle is detected, high pressure gas is injected into a gas chamber formed in the housing, thereby moving the piston and pulling the wire. A guide pipe for protecting the wire is disposed in the gas chamber in the housing.
JP 2003-146184 A (FIGS. 2 and 4)

  However, in the above prior art, the high-pressure gas flowing into the gas chamber is blocked by the guide pipe for protecting the wire, and thus tends to be guided to a minute gap at both ends of the guide pipe. As a result, high temperature heat may concentrate locally on the wire exposed in the gap.

  In order to optimize the pretensioner, it is required to pursue heat dispersion.

  Accordingly, an object of the present invention is to provide a technique effective in achieving the optimization of a pretensioner device by distributing heat with a high-temperature gas.

  In order to achieve the above object, a first invention is a pretensioner for restraining an occupant by a seat belt by retracting a seat belt buckle when an impact of a vehicle occurs, and the seat belt at one end portion. A wire connected to a buckle; a piston connected to the other end of the wire; a cylinder that slidably accommodates the piston; a housing that penetrates the wire and holds the cylinder; and the wire A gas supply means for supplying a gas for operating the piston in the direction in which the piston is drawn into the cylinder through the housing, and a gas supply means disposed in the housing so as to cover at least the gas supply means side of the outer peripheral surface of the wire. A diffusion member made of a porous material and capable of diffusing the gas, and disposed in the housing. Is characterized in that a seal member for sealing between the wire or the diffusion member and the inner wall surface of the housing.

  In such a pretensioner, when an impact of the vehicle occurs, a gas for moving the piston (hereinafter referred to as high pressure gas) is injected by the gas supply means, and the high pressure gas is supplied to the cylinder through the housing. Then, the piston moves by the pressure of the high-pressure gas to pull in the wire, and the seat belt buckle is pulled in accordingly.

  Here, since the diffusion member made of a porous material is provided at least on the gas supply means side on the outer peripheral side of the wire, when the high pressure gas is injected by the gas supply means, the high pressure gas is diffused by the porosity of the diffusion member. . As a result, it is possible to diffuse high-temperature heat from the high-pressure gas and prevent local concentration of the high-temperature heat on a part of the wire as in the conventional structure.

  In a second aspect of the present invention, preferably, the diffusion member is configured to extend to an inner side of an end surface of the piston on the diffusion member side in a state where the piston is in an initial position with respect to the cylinder. To do.

  By adopting a structure in which the diffusing member sinks inside the piston, the adhesion between both members can be improved.

  The third invention is preferably characterized in that the seal member has a tapered shape that tapers toward the opposite side of the diffusion member.

  In this case, the seal member is easily pushed into the opposite side of the diffusion member by the pressure of the high-pressure gas injected by the gas supply means. Thereby, the adhesiveness of a sealing member and a housing inner wall surface can be improved.

  In a fourth aspect of the present invention, preferably, the diffusion member is configured by forming the heat-resistant material as the porous material into a mesh shape.

  By providing a mesh shape such as weaving a heat-resistant material resistant to high temperatures, air permeability can be imparted, and thereby high-temperature gas can be reliably diffused.

  The fifth invention is preferably characterized in that the heat-resistant material is a non-metal.

  Thereby, it is possible to realize a diffusion member that is resistant to high temperatures and has air permeability.

  The sixth invention is preferably characterized in that at least a part of the diffusing member is covered with a coating agent.

  Thereby, in the diffusing member constituted by knitting, it is possible to prevent partial fraying in the knitted state from occurring. In addition, since the coating material is melted by the high temperature when the high temperature gas flows in, the gas diffusion function by the porous material of the diffusion member is not hindered.

  The seventh invention is a seat belt, a retractor that winds up the seat belt, a tongue provided on the seat belt, a seat belt buckle to which the tongue is attached and detached, and retracting the seat belt buckle when a vehicle impact occurs, A seat belt device including a pretensioner for restraining an occupant by a seat belt, wherein the pretensioner includes a wire connected to the seat belt buckle at one end, and the other end of the wire A piston connected to the piston, a cylinder for slidably housing the piston, a housing for penetrating the wire and holding the cylinder, and a gas for operating the piston in the direction of drawing the wire, A gas supply means for supplying gas into the cylinder through the housing; A diffusing member that is disposed in the housing so as to cover at least the gas supply means side of a peripheral surface and is made of a porous material and capable of diffusing the gas, and is disposed in the housing, and the wire or the diffusing member And a sealing member for sealing between the inner wall surface of the housing.

  In such a seat belt device, by providing the above-described pretensioner, it is possible to diffuse high-temperature heat from the high-pressure gas and prevent local concentration on a part of the wire as in the conventional structure.

  According to the present invention, heat can be dispersed by high-temperature gas, and the pretensioner device can be optimized.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a pretensioner and a seat belt device according to the present invention will be described in detail with reference to the drawings.

  First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a seat belt apparatus provided with a first embodiment of a pretensioner according to the present invention.

  In the figure, a seat belt device 1 includes a seat belt 3 for restraining an occupant that is fed from a retractor 2. The retractor 2 is a device that winds up the seat belt 3 and is fixed to the lower portion of the center pillar 4 on the vehicle interior side. The seat belt 3 drawn out from the retractor 2 to the upper side of the vehicle body is inserted through a through ring 5 attached to the upper part of the center pillar 4 and folded back toward the lower side of the vehicle body. The leading end of the seat belt 3 is fixed to an anchor plate 7 provided between the center pillar 4 and the seat 6.

  A tongue 8 is provided in a portion of the seat belt 3 between the through ring 5 and the anchor plate 7 so that the seat belt 3 can be inserted therethrough. The tongue 8 is attached to and detached from a seat belt buckle 9 disposed on the opposite side of the anchor plate 7 across the seat 6.

  The seat belt buckle 9 holds the pretensioner 10 of the present embodiment. The pretensioner 10 is a device for restraining the occupant by the seat belt 3 by pulling the seat belt buckle 9 when the vehicle suddenly stops or when an impact such as a collision occurs.

  The pretensioner 10 includes a wire 11 connected to the seat belt buckle 9, a housing 12 that is fixed to the vehicle body directly or via a bracket (not shown), and penetrates the wire 11, and one side of the housing 12. It has a holder 13 having a guide portion 13a (see FIG. 2) which is held by the portion and guides the wire 11 so as to bend a part thereof, and a cylinder 14 held by the other side portion of the housing 12.

  FIG. 2 is a vertical sectional view of the pretensioner 10. In the drawing, one end of the wire 11 is held by a seat belt buckle 9 (see FIG. 1), and the other end of the wire 11 is held by a piston 15. The piston 15 is slidably accommodated in the cylinder 14.

  The piston 15 includes a piston main body portion 16 that allows the wire 11 to pass therethrough, and a wire holding portion 17 that is coupled to the tip of the piston main body portion 16 and fixes the other end portion of the wire 11. An O-ring 19 that seals between the piston body 16 and the inner wall surface of the cylinder 14 is disposed in the annular groove 18 formed in the piston body 16.

  The piston body 16 has a tapered portion 20 that is formed on the distal end side (wire holding portion 17 side) of the annular groove portion 18 and gradually increases in diameter toward the distal end side. A ball ring 21 and a plurality of balls 22 are disposed between the tapered portion 20 and the inner wall surface of the cylinder 14. As a result, movement of the piston 15 toward the distal end side (A side in the figure) is allowed, and movement of the piston 15 toward the proximal end side (in the figure B side) is prevented.

  The housing 12 that holds the cylinder 14 is provided with a gas generator 23 that generates high-pressure gas for moving the piston 15 to the A side in the figure. Although not shown, the gas generator 23 has a gas generation part and an ignition part. For example, when a sudden deceleration of the vehicle is detected by a sensor (not shown), an ignition signal is sent to the ignition part and the ignition part is Operates, and the gas generator injects high-temperature high-pressure gas.

  Inside the housing 12, a gas flow path 24 for supplying the high-pressure gas injected from the gas generator 23 to the cylinder 14 and the gas flow path 24 communicate with the gas flow path 24, and the diameter gradually decreases toward the holder 13. The seal accommodating portion 25 is formed. The gas flow path 24 is formed between the cylinder 14 and the seal housing portion 25 in the housing 12.

  A diffusion member 26 is provided in the gas flow path 24 so as to cover at least the outer peripheral surface of the wire 11 on the gas generator 23 side. The diffusion member 26 is made of a porous material (see FIG. 3). In this example, the diffusion member 26 is made of a non-metal having a low thermal conductivity, preferably a heat-resistant material such as glass fiber or ceramic fiber, and knitted by knitting them. Or you may comprise the diffusion member 26 with a sintered metal. Further, for example, a plurality of holes (through holes or non-through holes) may be provided in a cylindrical body made of metal or the like, and thereby the diffusing member 26 may be configured. By configuring the diffusing member 26 with the porous material in this way, the high temperature gas can be reliably diffused (in the case of a through-hole, air permeability can be further increased).

  At this time, preferably, at least part of the diffusing member 26 (for example, both ends in the axial direction) may be covered with a predetermined coating agent (not shown). Thereby, for example, when the diffusing member 26 is formed in a mesh shape by knitting as described above, it is possible to prevent partial fraying in the knitted state. At this time, since the coating agent is melted by the high temperature when the high temperature gas flows in, the gas diffusion function of the porous member of the diffusion member 26 is not hindered.

  2 and 3, the diffusing member 26 includes a tubular portion 27 and an annular flange portion 28 provided on the outer peripheral surface of one end portion of the tubular portion 27 (the end portion on the seal accommodating portion 25 side). It is made up of. The inner diameter of the tubular portion 27 is slightly larger than the outer diameter of the wire 11, so that the wire 11 can slide relative to the diffusion member 26. Further, the other end of the tubular portion 27 is more than the base end surface (end surface on the diffusion member 26 side) 16a of the piston main body portion 16 when the piston 15 is in the initial position with respect to the cylinder 14 (the state shown in FIG. 2). Is also configured to extend to the inside, for example, to a position corresponding to the O-ring 19. Specifically, an annular recess 29 that fits with the tubular portion 27 is formed on the inner wall of the proximal end portion of the piston main body portion 16. The other end portion of the tubular portion 27 is fitted in the annular recess 29.

  The seal housing portion 25 is provided with a seal member 30 that seals between the wire 11 or the diffusing member 26 and the inner wall surface of the housing 12. The seal member 30 is configured separately from the diffusion member 26 (in FIG. 2 and FIG. 3, it is extracted and shown integrally for convenience), and the holder 13 corresponds to the diameter of the seal housing portion 25. It has a tapered shape that tapers toward the side. The seal member 30 is formed of, for example, a rubber material (such as synthetic rubber including various additives), a synthetic resin material, or a metal material having elasticity. Further, the inner diameter of the seal member 30 is slightly larger than the outer diameter of the wire 11 so that the wire 11 can slide relative to the seal member 30.

  In the present embodiment configured as described above, when the vehicle detects a sudden deceleration, for example, when the vehicle suddenly stops or collides, an ignition signal is sent to the ignition part of the gas generator 23, A high-temperature high-pressure gas is injected from the gas generator 23. The high-pressure gas is supplied to the cylinder 14 through the gas flow path 24 in the housing 12. As a result, the piston 15 is displaced in the direction A of FIG. 2, and the wire 11 is drawn as shown in FIG. 4, and the seat belt buckle 9 is drawn accordingly.

  At this time, since the diffusion member 26 made of a porous material is provided on the outer peripheral side of the wire 11, when the high pressure gas is injected from the gas generator 23, the high pressure gas is diffused by the porosity of the diffusion member 26. As a result, it is possible to diffuse high-temperature heat from the high-pressure gas and prevent local concentration on a part of the wire 11 as in the conventional structure.

  In the present embodiment, in particular, since the annular flange portion 28 that engages with the seal member 30 is provided at one end portion of the diffusion member 26, when the high pressure gas is injected from the gas generator 23, the high pressure gas is discharged as described above. The annular flange portion 28 receives pressure, and the annular flange portion 28 is pressed toward the seal member 30 side. At this time, since the seal member 30 is tapered with respect to the opposite side of the diffusion member 26, the annular flange portion 28 is sufficiently pushed into the seal member 30 side. As a result, the adhesion between the diffusing member 26 and the seal member 30 is increased, so that a gap is hardly formed between the diffusing member 26 and the seal member 30. Therefore, pressure efficiency can be improved. Note that the annular flange portion 28 is not necessarily provided as long as the effect of diffusing heat by the high-pressure gas inherent to the present invention is obtained.

  Further, particularly in the present embodiment, in a state where the piston 15 is in the initial position with respect to the cylinder 14, the tubular portion 27 of the diffusion member 26 extends to the inside of the piston main body portion 16. By adopting a structure that sinks into the inside of the piston main body 16, the adhesion between the members 26 and 16 can be improved, and the pressure efficiency can also be improved. In addition, as long as the effect of diffusing heat due to the high-pressure gas inherent to the present invention is obtained, the diffusion member 26 does not necessarily have to enter the piston body 16 as described above.

  A second embodiment of the present invention will be described with reference to FIGS. In the figure, the same or equivalent members as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 5 is a vertical sectional view showing a second embodiment of the pretensioner according to the present invention. In the same figure, the pretensioner 40 of this embodiment has a diffusion member 41 and a seal member 42 instead of the diffusion member 26 and the seal member 30 in the first embodiment. The diffusion member 41 is a tubular body as shown in FIG. 6 and is formed of the same material as the diffusion member 26 described above. As shown in FIG. 6, the seal member 42 has a tapered shape that tapers toward the holder 13, and is formed of the same material as the seal member 30 described above. The outer diameter of the end surface (base end surface) 42 a on the diffusion member 41 side in the seal member 42 is larger than the outer diameter of the diffusion member 41.

  The diffusion member 41 extends to the inner side of the base end surface 42a of the seal member 42. That is, an annular recess 43 that fits with the tubular diffusion member 41 is formed on the inner wall of the seal member 42. The end of the diffusing member 41 on the seal member 42 side is fitted in the annular recess 43. As a result of such a structure, the seal member 42 seals between the diffusion member 41 and the wire 11 and the inner wall surface of the housing 12.

  Also in such a pretensioner 40, the same thermal diffusion effect as that of the first embodiment is obtained.

  In the present embodiment, in particular, when the high pressure gas is injected from the gas generator 23, the pressure of the high pressure gas is received by the base end surface 42a of the seal member 42, so that the seal member 42 is pressed to the holder 13 side as it is. The At this time, since the seal member 42 is structured to seal between the diffusion member 41 and the wire 11 and the inner wall surface of the housing 12 as described above, the seal member 42 is pushed by being pushed in as described above. And adhesion between the diffusion member 41 and the inner wall surface of the housing 12 are enhanced. As a result, it is difficult to form a gap between the diffusing member 41 and the seal member 42. In particular, the taper shape increases the adhesion between the diffusing member 41 and the seal member 42, thereby increasing the effect of suppressing the generation of the gap. Therefore, the pressure efficiency can be improved as described above. In addition, as long as the effect of diffusing heat by the high-pressure gas inherent to the present invention is obtained, the end of the diffusion member 41 on the seal member 42 side does not have to be fitted into the annular recess 43 as described above.

  A third embodiment of the present invention will be described with reference to FIG. In the figure, the same or equivalent members as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 7 is a vertical sectional view showing a third embodiment of the pretensioner according to the present invention. In the figure, the pretensioner 50 of the present embodiment is substantially equivalent to a combination of the structure of the first embodiment and the structure of the second embodiment, and specifically, diffusion in the second embodiment. A diffusing member 51 is provided instead of the member 41. The diffusion member 51 includes a tubular portion 52 and an annular flange portion 53 that is provided on the outer peripheral surface of the tubular portion 52 and engages with the seal member 42. The diffusing member 51 is made of the same material as the diffusing member 26 in the first embodiment. The tubular portion 52 of the diffusing member 51 extends to the inner side of the base end surface 42a of the seal member 42, similarly to the diffusing member 41 in the second embodiment.

  Such a pretensioner 50 also obtains the same thermal diffusion effect as that of the first embodiment.

  In the present embodiment, particularly, when the high pressure gas is injected from the gas generator 23, the pressure of the high pressure gas is received by the annular flange portion 53, so that the annular flange portion 53 is pressed toward the seal member 42. Thereby, the adhesiveness of the diffusion member 51 and the sealing member 42 becomes sufficiently high, and there is an effect that the adhesiveness can be further improved and the pressure efficiency can be improved as compared with the first and second embodiments.

  In the structure shown in FIG. 5 and the structure shown in FIG. 7, the end of the diffusing member 41 is inserted into the seal member 42. However, the present invention is not limited to this. For example, FIG. As shown in FIG. 9, the axial dimension of the seal member 42 may be shortened so that the diffusion member 41 has a structure in the axial direction on the inner side. In these cases, similar effects can be obtained.

  Furthermore, the present invention is not limited to the above structure. For example, in the above embodiment, in the state where the piston 15 is in the initial position with respect to the cylinder 14, the diffusion member is more than the base end surface 16 a of the piston main body 16. Although it extends to the inside, it is not limited to such a configuration. For example, the piston member 16 may be configured to contact the base end surface 16a of the piston body 16 without providing the annular recess 29 in the piston body 16, or at the end of the diffusion member on the piston 15 side. While providing the annular flange part engaged with the piston main-body part 16, you may form several through-holes for allowing a high pressure gas to pass through in the said annular flange part.

  Moreover, in the said embodiment, although the shape of the sealing member was made into the taper shape, especially the shape of a sealing member is not restricted to this, It is good also as a cylindrical shape where an outer diameter dimension is equal in the whole axial direction.

It is a perspective view showing a seat belt device provided with a first embodiment of a pretensioner according to the present invention. FIG. 2 is a vertical sectional view of the pretensioner shown in FIG. 1. It is a perspective view which extracts and represents the diffusion member and seal member shown in FIG. FIG. 3 is a vertical sectional view showing a state where the pretensioner shown in FIG. 2 is operated. It is a vertical direction sectional view showing a 2nd embodiment of the pretensioner concerning the present invention. It is a perspective view of the diffusion member and seal member shown in FIG. It is a vertical direction sectional view showing a 3rd embodiment of the pretensioner concerning the present invention. It is a vertical direction sectional view showing the modification in which a diffusion member penetrates a seal member. It is a vertical direction sectional view showing other modification which a diffusion member penetrates a seal member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Seat belt apparatus 2 Retractor 3 Seat belt 8 Tongue 9 Seat belt buckle 10 Pretensioner 11 Wire 12 Housing 14 Cylinder 15 Piston 16a Base end surface 23 Gas generator (gas supply means)
24 Gas flow path (gas supply means)
26 Diffusion Member 28 Tubular Flange 30 Seal Member 40 Pretensioner 41 Diffusion Member 42 Seal Member 42a Base End Surface 50 Pretensioner 51 Diffusion Member

Claims (7)

A pretensioner for restraining an occupant by a seat belt by retracting a seat belt buckle when a vehicle impact occurs,
A wire connected to the seat belt buckle at one end;
A piston connected to the other end of the wire;
A cylinder that slidably accommodates the piston;
A housing for penetrating the wire and holding the cylinder;
A gas supply means for supplying a gas for operating the piston in a direction in which the wire is pulled into the cylinder through the housing;
A diffusing member that is disposed in the housing so as to cover at least the gas supply means side of the outer peripheral surface of the wire, and is made of a porous material and capable of diffusing the gas;
A pretensioner, comprising: a seal member that is disposed in the housing and seals between the wire or the diffusing member and an inner wall surface of the housing.   The diffusion member is configured to extend to an inner side of an end surface of the piston on the diffusion member side in a state where the piston is in an initial position with respect to the cylinder. The pretensioner described.   The pretensioner according to claim 1, wherein the seal member has a tapered shape that tapers toward an opposite side of the diffusion member. The diffusion member;
The pretensioner according to any one of claims 1 to 3, wherein the heat resistant material as the porous material is formed in a mesh shape.   The pretensioner according to claim 4, wherein the heat resistant material is a non-metal.   The pretensioner according to claim 4 or 5, wherein at least a part of the diffusing member is covered with a coating agent. Seat belts,
A retractor that winds up the seat belt;
A tongue provided on the seat belt;
A seat belt buckle to which the tongue is attached and detached;
A seat belt device including a pretensioner for restraining an occupant by the seat belt by retracting the seat belt buckle when a vehicle impact occurs,
The pretensioner is
A wire connected to the seat belt buckle at one end;
A piston connected to the other end of the wire;
A cylinder that slidably accommodates the piston;
A housing for penetrating the wire and holding the cylinder;
A gas supply means for supplying a gas for operating the piston in a direction in which the wire is pulled into the cylinder through the housing;
A diffusing member that is disposed in the housing so as to cover at least the gas supply means side of the outer peripheral surface of the wire, and is made of a porous material and capable of diffusing the gas;
A seat belt device comprising: a seal member disposed in the housing and sealing between the wire or the diffusing member and an inner wall surface of the housing.

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