JP4246865B2 - Seat belt device - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a pretensioner that is used in a retractor of a seat belt device such as a vehicle and forcibly rotates a webbing take-up shaft and tensions the webbing in an occupant restraining direction when the vehicle suddenly decelerates.
[0002]
[Prior art]
Conventionally, various types of retractor pretensioners are known from the viewpoint of the principle of the emergency winding structure for webbing. For example, a system that pushes rolling elements (mass body) with gas pressure, a so-called "slip" system that uses wires, a system that rotates a spring-spring-like member with gas pressure, and a gas For example, the planetary gear is driven to rotate by pressure.
[0003]
Among these various types of pretensioners, examples of a method of extruding rolling elements with gas pressure and the like include, for example, Japanese Patent Laid-Open No. 56-23972, German Patent Publication “DE 195 12 660 A1”, German Patent Publication “DE 196 02 549A1 ”and the like are known.
In a pretensioner equipped with these rolling elements, as represented by, for example, Japanese Patent Laid-Open No. Sho 56-23972, a plurality of rolling elements are pumped through a duct with high-pressure gas at the time of a vehicle collision, and the rolling elements are moved to a retractor. By sequentially engaging with drive gears mounted around the shaft, the retractor shaft is provided with a torque for rapidly winding the seat belt.
[0004]
The pretensioner with a structure that directly rotates the retractor shaft using the urging force of the rolling element sets a longer stroke for moving the rolling element, that is, a moving path of the rolling element, in order to generate a sufficient urging force. There is a need to. For this reason, if the moving path is simply formed in a straight line, the entire pretensioner is enlarged in a specific direction. Usually, the pipe serving as the moving path is twisted or bent into a spiral shape to obtain a sufficient length. We are trying to ensure the correct stroke.
[0005]
[Problems to be solved by the invention]
However, the pretensioner that secures the moving path is complicated in its machining process and has high machining accuracy because the path width must always be kept at a predetermined value even in a curved portion because the pipe is bent in a complicated manner. There are many parts that are required. For this reason, the manufacturing cost increases. On the other hand, even if an increase in size in a specific direction can be avoided, an increase in the size of the entire pretensioner is inevitable. In addition, since the shape of the moving passage is complicated, a high countermeasure against gas leakage is required. Therefore, finally, the manufacturing cost is increased and the size is increased.
The present invention generates a sufficient amount of rotation of the retractor shaft for winding the webbing even when the moving stroke of the pressure transmitting material pushed out by the pressure is short, and has a webbing winding function equivalent to that when the stroke length is long. On the other hand, an object of the present invention is to reduce the manufacturing cost while reducing the overall structure by reducing the size and simplifying the vehicle and facilitating on-vehicle use.
[0006]
Another object of the present invention is to reduce gas leakage in the moving passage.
[Means for Solving the Problems]
In order to achieve the above object, a seat belt device of the present invention includes a pipe or a housing including a pressure chamber and a moving body passage communicating with the pressure chamber, and a high-pressure gas provided in the pipe or housing. A pressure applying device that generates the pressure, a moving body arranged in the moving body passage, an extrusion member that moves the moving body under the high pressure, and a coaxial arrangement with the retractor shaft, and the outer circumference is unidirectional. A clutch connected to the retractor shaft, a tension medium attached at one end to the outer periphery of the clutch and wound around the clutch, and the other end engaged with the movable body and attached to the housing. The other end of the tension medium is fixed by a clamp whose release is restricted by the position of the moving body.
[0007]
Preferably, the retractor shaft is plastically deformed when a force exceeding a certain value is applied, and the webbing take-up mechanism is free.
[0008]
Preferably, the clutch includes a pulley having a cam formed on an inner surface, a plate including a claw portion that comes into contact with the cam, and a sleeve that can mesh with the claw portion. Deviation (phase difference) occurs in
[0009]
Preferably, the moving body includes a groove that engages with the pulling medium at a leading portion, and reliably engages with the pulling medium.
[0010]
By adopting such a configuration, a larger amount of the tension medium than the moving distance of the moving body is extracted (acceleration), and a compact pretensioner can be configured. In addition, after the pretensioner is operated, the tension medium is released from the clamp, so that the retractor shaft can be freely rotated, and the wound webbing can be drawn out.
[0011]
A seat belt device according to the present invention includes a pipe or a housing including a pressure chamber and a moving body passage communicating with the pressure chamber, and a pressure applying device that is provided in the pipe or the housing and generates high-pressure gas in the pressure chamber. When the outer periphery rotates in one direction, the retractor shaft is arranged coaxially with the retractor shaft, the movable member disposed in the movable body passage, the push member that moves the movable body under the high pressure, and the retractor shaft. And a tension medium attached at one end to the outer periphery of the clutch and wound around the clutch, and the other end engaged with the movable body and attached to the housing. A rigid body to which a high pressure is applied, and a seal member that is spread outward by the rigid body and is in close contact with the inner surface of the moving body passage.
[0012]
By adopting such a configuration, it is possible to prevent gas leakage from the moving body passage and to effectively use the gas pressure. Further, since the sealing member is positively spread, there is little influence even if there is some variation in the accuracy of the single member of the push-up member.
[0013]
The seat belt device of the present invention includes a housing including a pressure chamber and a moving body passage communicating with the pressure chamber, a pressure applying device that is provided in the housing and generates high-pressure gas in the pressure chamber, and the moving body. A moving body arranged in the passage, an extrusion member that moves the moving body under the high pressure, and a clutch that is arranged coaxially with the retractor shaft and that is connected to the retractor shaft when the outer periphery rotates in one direction. And a tension medium attached at one end to the outer periphery of the clutch and wound around the clutch, and having the other end engaged with the movable body and attached to the housing, and the movable body passage is centered on the retractor shaft The movable body is single or arcuate.
[0014]
With such a configuration, a compact pretensioner can be configured.
[0015]
Further, the present invention is a pretensioner that forcibly rotates the webbing take-up shaft and tensions the webbing in the occupant restraint direction when the vehicle suddenly decelerates, and is movable to a passage provided in a pipe or a housing. A contained moving body, an extruding member that moves the moving body under pressure, a pressure applying device that applies pressure to the extruding member to move the moving body, and changes the movement of the moving body into a circular motion And a clutch device that transmits the rotational torque to the take-up shaft and rotates the take-up shaft in the webbing take-up direction.
Since the pretensioner having this structure is equipped with a speed increasing mechanism that changes the movement of the moving body into a circular movement, it is sufficient for winding up the webbing even if the linear moving stroke of the moving body is short. Can generate a large rotational torque.
[0016]
Preferably, the pipe is an L-shaped pipe. In this pipe, a gas generator is attached to one pipe having a cylindrical cross section, and a plurality of moving bodies are accommodated in the other pipe having a square cross section.
[0017]
Preferably, a push-up member serving as a piston is disposed in a storage portion of the moving body by a pipe or a housing, and the push-up member is pushed outward by gas pressure.
[0018]
Further, a projection is formed in a piston ring shape on the outer periphery of the push-up member, and the projection is brought into close contact with the cylinder to improve the sealing performance.
[0019]
Further, the push-up member is formed with a through-hole that communicates the gas expansion chamber and the movable body side space in order to release the residual pressure of the expansion gas.
[0020]
Further, the push-up member is provided with a buffer material in order to suppress the vibration of the moving body.
[0021]
Preferably, the end of the tension medium is cast so that the locking by the clamp is more reliable.
[0022]
In addition, a "<" shape utilizing a lever principle is used for the clamp.
[0023]
Preferably, a groove for accommodating a tension medium is formed in the moving body passage. Thereby, it is avoided that the tension medium is pinched by the movable body passage wall and the movable body, and damage to the tension medium is reduced.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a seat belt device including a retractor including a pretensioner according to a first embodiment of the present invention will be described with reference to the drawings. In the drawings, corresponding parts are denoted by the same reference numerals, and redundant description is omitted.
[0025]
1 is an explanatory view showing a state in which the seatbelt device retractor according to the first embodiment is viewed from the side surface in the axial direction, and is shown by a cross-sectional view in the BB direction (pretensioner portion) shown in FIG. ing. 2 is a cross-sectional view of the retractor shown in FIG. 1 in the AA direction (pretensioner portion). FIG. 3 is an explanatory diagram illustrating the configuration of the clutch. 4 and 5 are explanatory diagrams for explaining the operation of the clutch.
As shown in FIGS. 1 and 2, the retractor 10 for a seat belt apparatus according to Embodiment 1 includes a retractor body 13 that winds up a webbing (not shown), and one end portion in the axial direction of the retractor body 13. The emergency lock mechanism 14 is provided, and the pretensioner 12 and the take-up spring device 11 are sequentially provided at the other end.
[0026]
The retractor body 13 includes a take-up reel 22 that can freely wind or pull out the webbing. The take-up reel 22 is always urged in the direction in which the webbing is taken up by the take-up spring device 11 connected to the retractor shaft 24 that is the take-up shaft. Furthermore, when the webbing is to be pulled out at an acceleration of a predetermined value or more, the emergency lock mechanism 14 connected to one end of the retractor shaft 24 in the axial direction is operated, the rotation of the retractor shaft 24 is prevented, and the webbing is not pulled out. It is configured as follows.
[0027]
The take-up reel 22 portion of the retractor shaft 24 is a torsion shaft 24a. For example, as shown in Japanese Patent Application Laid-Open No. 46-7710, when an excessive force is applied after the emergency locking mechanism is operated, the torsion shaft 24a The take-up reel 22 that is twisted and plastically deformed and connected to the left side of the shaft 24a through the sleeve 44a in a non-rotatable manner is rotatable in the webbing pull-out direction.
[0028]
The casing of the pretensioner 12 is formed by fitting a plate 28 into the housing 26 as a lid body in an airtight manner. This casing has a built-in mechanism for forcibly winding the webbing and instantly eliminating the slack of the webbing when a sudden deceleration occurs during a vehicle collision. Hereinafter, the configuration of this mechanism will be described.
[0029]
As shown in FIG. 2, a pressure chamber 30 is formed in the housing 26 in the lower lateral direction. A pressure applying device 32 is inserted into one end side of the pressure chamber 30 and is attached by screwing a cap 34 to the housing 26 from the outside. The pressure application device 32 is, for example, a horizontal-type pressurized gas generator, and the pressurized gas generator includes an electrode, an ignition device, and a high-pressure gas generating agent (not shown). Connected to the electrode is an ignition signal transmission harness for transmitting a signal from a shock sensor for detecting a rapid acceleration generated at the time of a vehicle collision. When an ignition signal is transmitted from the shock sensor to the electrode, the ignition device ignites the high-pressure gas generating agent to instantly generate high-pressure gas.
[0030]
A moving body passage 38 extending upward from the upper part on the other end side of the pressure chamber 30 is formed in the housing 26. The moving body passage 38 includes a straight path portion (cylinder) 38 a and a peripheral circuit 38 b centering on the retractor shaft 24. A plurality of rolling elements 36 as moving bodies are arranged in a line in the straight path portion 38a.
[0031]
For example, as shown in FIG. 10, the rolling element 36 preferably has a columnar (cylindrical) shape having a width B narrower than the diameter A (A> B). Preferably, the uppermost rolling element 36 has an engagement groove 36a that engages with a tension medium 40 described later, as shown in FIG.
[0032]
An extrusion member 42 is provided below the lowermost rolling element 36 so as to be in close contact with the moving body passage 38a and push up the rolling element 36 by gas pressure. In order to prevent gas leakage, the push-out member 42 has an outer diameter slightly larger than the inner diameter of the straight path (cylinder) portion 38a before assembly (see FIG. 51).
[0033]
A clutch device 44 is provided on the retractor shaft 24 for winding the webbing. As shown in FIG. 3, the clutch device 44 includes a sleeve 44a, a plate 44b, and a pulley 44c that are concentrically arranged.
[0034]
A plurality of projections (claws) 44bb bent in the axial direction are formed on the plate 44b, and holes 44ba are formed at the roots of the projections 44bb of the plate 44b so that the projections 44bb are easily deformed. The cross-sectional area of the bent projection (claw) 44bb of the plate 44b is a quadrangle in the illustrated example, but various shapes such as a circle, an ellipse, and a bow (arc) shape can be appropriately selected.
[0035]
As shown in FIGS. 1 and 2, the sleeve 44 a is attached to the left end side of the retractor shaft 24 and is connected to the reel 22 so as not to rotate relative thereto. On the surface of the sleeve 44a facing the pulley 44c, a large number of groove ridges (knurls) that circulate around the shaft (retractor shaft 24) are formed in the axial direction, and a meshing force is generated when the projections 44bb of the plate 44b come into contact.
[0036]
Pulling medium 40 is attached to the outer peripheral surface of pulley 44c, and the cam surface is formed on the inner peripheral surface. This cam surface is opposed to the groove portion of the sleeve 44a through the protrusion 44bb of the plate 44b. The plate 44b is held by an inertial body, a frictional holding member, a shearing pin, or the like so that the pulley 44c rotates with a delay after the pulley 44c rotates and a deviation (phase difference) occurs. For example, the pulley 44c sandwiches the plate 44b between its side surface and the housing 26, and generates an appropriate frictional force that causes a phase difference.
[0037]
4 and 5 are explanatory diagrams for explaining the operation of the clutch device 44. In the state shown in FIG. 4, when the pulley 44c rotates counterclockwise relative to the plate 44b, the projection 44bb is bent toward the axial center by the cam surface of the pulley 44c and abuts against the groove of the sleeve 44a. As shown in FIG. 5, a protrusion 44bb is interposed between the inner surface of the pulley 44c and the groove 44 of the sleeve 44a, and the rotation of the pulley 44c is transmitted to the retractor shaft 24 through the protrusion 44bb and the sleeve 44a. Is done. Thereby, the webbing can be wound.
[0038]
The outer diameter of the pulley 44 c of the clutch 44 is smaller than the outer diameter of the reel 22. On the outer peripheral surface of the clutch 44 (pulley 44c), a mechanism in which a tension medium 40 as a speed increasing mechanism is wound almost twice is provided. The tension medium 40 is a linear body or a belt-like body, and is formed of a metal material having a predetermined width and length, such as a wire, a rope, or steel. One end of the tension medium 40 is fixed to the outer peripheral surface of the clutch 40 by hooks, screws, spot welding, etc. (not shown). After the tension medium 40 is wound a plurality of times (for example, approximately two turns as shown in FIG. 1) in the counterclockwise direction in FIG. 2, the other end crosses the moving body passage 38 and clamps the housing space 26a of the housing 26. Insert into 46 and secure.
[0039]
The clamp 46 is a longitudinally extending longitudinal member that forms a part of the moving body passage 38b whose inner surface circulates, and the outer surface of the clamp 46 is engaged by a series of teeth that catch the tension medium 40. A stop 46a is formed. The lower end side of the clamp 46 is fixed by a pin 46b so as to be rotatable, and the upper end side of the clamp 46 is movable in a pendulum shape.
[0040]
As described above, a plurality of cylindrical rolling elements 36 are inserted into the movable body passage 38a in a row so as to be in contact with each other and freely rollable. The leading ends of the plurality of rolling elements 36 are located between the side surface of the clamp 46 and the clutch 44 as shown in FIG. The tension medium 40 wound around the clutch 44 makes a half turn in contact with the side surface of the leading rolling element 36, passes between the rolling element 36 and the inside of the clamp 46, and extends from the lower end of the clamp 46 to the outer side surface of the clamp 46. And is clamped and fixed by the locking portion 46a of the clamp 46 and the inner wall of the housing.
[0041]
When a certain amount of strong pressure is applied to the rolling element 36 at the lower end of the rolling element row via the pushing portion 42, the pressure is transmitted to the rolling element 36 on the opposite side, and the plurality of rolling elements 36 are integrally moved as a whole row. It can move in the passage 38a. As shown in FIG. 7, when the row of the rolling elements 36 moves and moves from the moving body passage 38a to the circulating passage 38b, the leading rolling body 36 pushes the pulling medium 40 and the outer periphery of the clutch 44. And the circumferential path of the circulation passage 38b formed by the inner periphery of the housing 26. That is, if necessary, a circumferential groove is formed on the inner surface of the housing 26 so as to communicate with the moving body passage 38a and between the outer peripheral portion of the clutch device 44, and the rolling element 36 has the circumferential groove. Go around.
[0042]
Next, the operation of this embodiment will be described. First, in the initial state in which the occupant gets on the vehicle, sits down, and wears the webbing, the pretensioner 12 is in the initial state shown in FIGS. In this initial state, as shown in both figures, since the projection 44bb of the plate 44b and the sleeve 44a are separated from each other, the clutch device 44 is not involved in the pretensioner 12, and the winding spring device 11 performs webbing. Is pulled out and can be rolled up.
[0043]
In this initial state, it is assumed that a sudden speed reduction occurs at the time of a collision in the vehicle. As a result, the pressure application device 32 instantaneously generates a pressurized gas, and this pressurized gas is released into the pressure chamber 30. As a result, a sudden pressing force is applied to the pushing member 42 from below, and the entire rolling element row is pushed out instantaneously from the moving passage 38a upward.
[0044]
This pushing force is superior to the force of the tension medium 40 holding the rolling element row in the initial state. As shown in FIG. 7, the rolling element row moves to the circulation passage 38 b while pushing the intermediate portion of the moving passage crossing portion of the tension medium 40. That is, the linear motion in the linear passage 38a in which the rolling element row is easy to move is changed to the circular motion along the circumferential activation in the circular passage 38b.
[0045]
At this time, one end of the tension medium 40 is fixed to the outer periphery of the pulley 44c of the clutch 44, and the other end is fixed to the clamp 46 after being wound around the pulley 44c at least once. For this reason, the tension medium 40 pushed by the rolling element row that has shifted to the circular motion draws the tension medium part outside the clutch by the pushed amount, that is, the length twice the moving distance of the rolling element row. As a result, the pulley 44c of the clutch 44 rotates by an angle corresponding to the pull-in amount. That is, the pulling medium 40 exhibits a double speed increasing action by a so-called “slip” method, and rotates the pulley 44c, which is the outer periphery of the clutch, in the direction of the arrow in FIG.
[0046]
As a result, the pulley 44c and the plate 44b are displaced, and the plurality of cam surfaces on the inner periphery of the pulley 44c deform the plurality of protrusions 44bb of the plate 44b and push the protrusions 44bb inwardly, and the protrusions 44bb engage the sleeve 44a. The clutch device 44 is engaged (see FIG. 5). As a result, the speed increasing mechanism represented by the tension medium 40 (that is, the pretensioner 12) and the retractor shaft 24 are coupled, and the retractor shaft 24 rotates in the direction of arrow A integrally with the rotation of the clutch device 44.
[0047]
As the rolling motion of the rolling element row proceeds, the amount of pulling by the tension medium 40 increases, and the rotation of the retractor shaft 24 proceeds at a stretch. The rotating torque of the retractor shaft 24 forcibly rotates the webbing take-up reel 22 fitted to the retractor shaft 24, and the webbing is wound in a very short time.
[0048]
When the webbing is finished and then the webbing is pulled out by the movement of the occupant during the collision, the winding reel 22 is rotated in the webbing drawing-out direction. This rotation is transmitted to the retractor shaft 24 via the sleeve 44a, which in turn rotates in the pull-out direction. At this time, since the right side of the shaft 24 in FIG. 1 is prevented from rotating in the webbing pull-out direction by the emergency lock mechanism, the torsion shaft 24a is twisted and plastically deformed as described above.
[0049]
When the retractor shaft 24 rotates in the webbing pull-out direction, the pulley 44c coupled to the retractor shaft 24 rotates in the reverse direction, winding (winding) the tension medium around the outer periphery of the pulley 44c, and rolling via the tension medium 40. Push the moving object back toward the initial position.
[0050]
As shown in FIG. 9, when the rolling element 36 is pushed back further than the initial position of the rolling element 36 shown in FIG. 8, the biasing force applied to the clamp 46 by the rolling element 36 is lost. The upper end side of can be moved, and the clamp is released. When one end of the tensioning medium 40 is released from the clamp, there is nothing limiting the rotation of the clutch 44 and further rotation of the retractor shaft 24 coupled to the clutch 44 is allowed.
[0051]
Therefore, when the seat belt device detects excessive acceleration, the webbing is fastened in a short time to restrain the occupant to the seat, and then the webbing is released, so that the safety and freedom of the occupant can be ensured.
[0052]
12 to 16 show other examples of the pushing member 42. The linear passage 38a of the rolling element 36 is a cylinder having the pushing member 42 as a piston, and plays a role of moving the rolling element while maintaining gas pressure. In this example, the pushing member 42 is deformed by the gas pressure to improve the sealing performance against gas leakage in the linear passage 38a when the rolling element 36 is moved.
[0053]
In the example shown in FIG. 12, the pushing member 42 is constituted by a piston (plate) 42a and a sealing member 42b which are square corresponding to a cylinder having a square cross section. A hole 42c is formed in the center of the seal member 42b. The seal member 42b is made of plastic such as rubber or resin. The piston 42a is selected to be harder (rigid body) than the sealing member 42b such as iron or hard plastic.
[0054]
As shown in FIG. 13, in the initial state, the seal member 42b is in close contact with the lower end of the rolling element 36. However, when gas pressure is generated, the piston 42a is pushed upward as shown in FIG. In close contact with the rolling element 36. A component component of the pushing-up force is generated in the lateral direction due to the arc shape at the bottom of the rolling element 36, and the seal member 42b is pushed and expanded in the direction of the arrow (outward) in the figure. Thereby, the sealing member 42b increases the degree of adhesion to the cylinder wall surface, and the gas sealing performance is improved. The rolling element 36 moves upward in the moving body passage 38a by pushing up the seal member 42b.
[0055]
15 and 16 show still another example of the pushing member 42. In this example, as shown in FIG. 15, a projecting portion (conical frustum portion) 42d having a taper is formed at the center of the piston 42a, and is in contact with the lower side of the seal member 42b having a hole 42c formed at the center. . The inner diameter of the hole 42c is set narrower than the outer diameter of the base of the protrusion.
[0056]
When the gas pressure is generated, as shown in FIG. 16, the piston 42a is pushed upward, and the protrusion 42d is pushed into the hole 42c of the seal member 42b. The seal member 42b is pushed and expanded in the direction of the arrow (outward) by the inclined surface of the protrusion 42d. Thereby, the sealing member 42b increases the degree of adhesion to the cylinder wall surface, and the gas sealing performance is improved. Since the seal member 42b is expanded by the rigid body, more reliable adhesion can be expected. The protrusion may be a triangular pyramid or a quadrangular pyramid, and a similar effect can be expected by forming a taper on the protrusion.
[0057]
According to such a seal structure, it is possible to obtain high confidentiality without being greatly affected by dimensional accuracy and the like, and it is possible to effectively use the gas pressure.
[0058]
17 to 24 show examples of other moving objects. In this example, as shown in FIG. 17, the moving body passage 38 starts from the pressure chamber 30, and the entire passage is formed so as to go around the clutch 44. As shown in FIG. 21, one moving body 64 having a square cross section in which the inner surface and the outer surface are formed in an arc shape so as to fit the moving body passage 38 is used. As shown in the cross-sectional view in the CC direction of FIG. 21 in FIG. 21, a groove 64 a with which the tension medium 40 is engaged is formed at the tip of the moving body 64.
[0059]
The pushing member 62 is in contact with the rear end of the moving body 64. The push-out member 62 prevents gas leakage at the cylinder portion 38 a and pushes up the moving body 64. The pushing member 62 has an arcuate inner side surface and an outer side surface, and has a square cross section. As shown in FIGS. 23 and 24, the width A of the pushing member 62 is slightly larger than the width B of the moving body passage 38a before assembly. Thereby, the pushing member 62 is brought into close contact with the passage wall, and the sealing performance is improved.
[0060]
FIG. 18 shows a state in which the moving body 64 has moved by the gas pressure from the initial state shown in FIG. Thereby, the drawing medium 40 wound around the pulley is drawn, the pulley rotates, and the clutch 44 operates. The pulley and shaft are connected. Since the operation as the pretensioner is the same as the example described above, the description thereof is omitted.
[0061]
19 and 20 show a state before the release of the clamp 46 and a state after the release, respectively. As in the example shown in FIGS. 8 and 9, when the moving body 64 returns to the position lower than the initial position, the urging force of the moving body 64 to the clamp 46 is lost, the clamp 46 is released, and the drawing medium 40 is released. Therefore, the retractor shaft 24 can freely rotate.
[0062]
As described above, according to the pretensioner according to the embodiment of the present invention, the speed increasing mechanism is centered on the moving body (row of rolling elements 36 or single moving body 64) and the "slip" type tension medium 40. Since a unique structure that does not exist in the past is combined, the stroke of the cylinder 38a that accommodates the moving body can be reduced. Therefore, the whole pretensioner is reduced in size and the vehicle-mounted conditions are eased. Moreover, since the sealing property of the extrusion member is good, the processing process of the moving body passage is simplified, and thereby the manufacturing cost can be reduced.
[0063]
Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, parts corresponding to those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0064]
In the second embodiment, an L-shaped pipe 70 is used as the passage 38 of the rolling element 36 of the pretensioner 12. This example will be described with reference to FIGS.
[0065]
FIG. 25 is a partial cross-sectional view of the retractor device similar to FIG. 1, and shows the pretensioner portion 12 in a cross-sectional view in the EE direction (pretensioner portion) shown in FIG. 26. 26 is a cross-sectional view of the pretensioner section in the DD direction (pretensioner section) shown in FIG. FIG. 27 is a perspective view showing an example of an L-shaped pipe. FIG. 28 is a cross-sectional view along the axial direction of the pipe.
[0066]
In this example, as shown in FIG. 27, an L-shaped pipe 70 is formed by a cylindrical pipe 72 and a rectangular pipe 74, and both pipes are connected via a constricted portion 76. The constricted portion 76 has a deep constriction on the upper side 76a and a gentle taper on the lower side 76b. The gas generator 32 is fitted into the end 78 of the pipe 72, and the end 78 is caulked and attached. In addition, the attachment by screwing or a cap may be sufficient. A plurality of rolling elements 36 are accommodated on the pushing member 42 inside the pipe 74. The extrusion member 42 is a heat-resistant elastic body.
[0067]
As shown in FIG. 51, the outer diameter (lateral width) A of the pushing member 42 is slightly larger (A> B) than the inner diameter (lateral width) B of the pipe 74, and the pushing member 42 is formed on the inner wall of the pipe (cylinder) 74. Adhere closely to prevent gas leakage.
[0068]
As described above, the rolling element 36 has a cylindrical shape (see FIG. 10), but as shown in FIG. 39, it can be reduced in weight as a hollow body. As shown in FIG. 11, the leading rolling element 36 in contact with the pulling medium 40 can be provided with an engaging groove 36a.
[0069]
In this way, the housing 26 can be easily manufactured by configuring the gas generator and the rolling element passage (rolling element storage portion) with an L-shaped pipe. In addition, the shape of the pretensioner 12 can be further reduced.
[0070]
29 to 33 show other examples of the clutch mechanism 44. In this example, a shear pin 26ca is used.
As shown in FIG. 29, the clutch 44 includes a sleeve 44a that fits into a retractor shaft (not shown), a plate 44b that is concentrically disposed so that a protrusion (claw) 44bb faces the groove surface of the sleeve 44a, and a protrusion ( (Claw) 44bb is constituted by a pulley 44c arranged so as to fit on the cam surface portion of the inner periphery. A shear pin 26ca is provided on a wall of the housing 26 that forms a clutch housing space. The shear pin 26ca is fitted into the hole 44ca of the pulley 44c through the long hole 44bc of the plate 44b. The position of the pulley 44c is determined by the shear pin 26ca. In the initial state where the pretensioner 12 does not operate, as shown in FIG. 30, the protrusion (claw) 44bb and the groove surface of the sleeve 44a are separated from each other, and the pulley 44c and the retractor shaft 24 are mechanically coupled. Not. When the gas generator generates 32 high-pressure gas and pushes the rolling element 36, the wound tension member 40 is pulled out and the pulley 44c rotates. Thereby, as shown in FIG. 31, the shear pin 26ca is sheared, a phase difference is generated between the pulley 44c and the plate 44b, and the plurality of protrusions (claws) 44bb are deformed in the axial direction by the cam surface of the pulley 44c. Further, as shown in FIG. 32, the pulley 44c rotates relative to the plate 44b, and a plurality of claw portions of the plate 44b bite into a number of grooves (knurls) of the sleeve 44a, as shown in FIG. Then, the clutch is engaged and the retractor shaft 24 is rotated. The speed increasing mechanism using the pulley 44c, the pulling medium 40, the rolling element 36, and the like rotates while increasing the speed to rotate the retractor shaft in the webbing take-up direction (direction of arrow A in the figure) (see FIG. 33), and the reel 22 Let the webbing take up.
[0071]
One end of the tension medium 40 is fixed to the housing 26 by a clamp 46 in the initial state as shown in FIG. The clamp 46 is pivotally supported on the housing 26 by a shaft 46b on the lower end side, and a plurality of teeth 46a are provided on the outer peripheral side of the clamp 46 so that the tension medium 40 can be easily fixed. One end portion of the tension medium 40 is formed by thin casting so that the plurality of teeth 46a of the clamp 46 can be easily bitten. The tension medium 40 is fixed by rotating the clamp 46 in the clockwise direction with one end of the tension medium 40 along the outer peripheral side of the clamp 46.
[0072]
When the above-described webbing winding is finished, and then the webbing is pulled out by the movement of the occupant during the collision, the winding reel 22 is rotated in the webbing pull-out direction. This rotation is transmitted to the retractor shaft 24 via the sleeve 44a, which in turn rotates the shaft 24 in the pull-out direction. At this time, since the right side of the shaft 24 in FIG. 25 is prevented from rotating in the webbing pull-out direction by the emergency lock mechanism 14, the torsion shaft 24a is twisted and plastically deformed as described above.
[0073]
When the retractor shaft 24 rotates in the webbing pull-out direction, the pulley 44c coupled to the retractor shaft 24 rotates in the reverse direction, winding (winding) the tension medium around the outer periphery of the pulley 44c, and rolling via the tension medium 40. The moving body 36 is pushed back toward the initial position.
[0074]
As shown in FIG. 35, when the rolling element 36 is pushed back further than the initial position of the rolling element 36 shown in FIG. 34, the biasing force applied to the clamp 46 by the rolling element 36 is lost. The upper end side of can be moved, and the clamp is released. When one end of the tensioning medium 40 is released from the clamp, there is nothing limiting the rotation of the clutch 44 and further rotation of the retractor shaft 24 coupled to the clutch 44 is allowed.
[0075]
36 to 38 show other examples of clamps. This clamp uses the lever principle to release the clamp.
[0076]
As shown in FIG. 36, the clamp 48 is formed in a “<” shape and is pivotally supported on the housing 26 by a shaft 48b at the center. In the initial state shown in FIG. 36 and the operating state of the pretensioner shown in FIG. 37, the load F applied by the rolling element 36 is applied to the upper side of the clamp 48. The clamp 48 tries to rotate clockwise around the shaft 48b as a fulcrum, and the lower tooth crest 48a of the clamp 48 is engaged with the retracting member 40 (FIG. 37).
[0077]
As shown in FIG. 38, when the webbing is pulled out as described above and the rolling element 36 is further pushed back from the initial position, the urging force applied to the clamp 48 by the rolling element 36 is lost. 48 rotates in a direction (counterclockwise) to release the holding of the tension medium 40. The tension medium 40 is released from the clamp 48 and further allows rotation of the retractor shaft in the webbing withdrawal direction.
[0078]
40 and 41 show an example in which damage to the tension medium 40 is reduced. 40 is a cross-sectional view of the pretensioner, and FIG. 41 is a cross-sectional view of the housing 26 in the FF direction in FIG. In this example, a groove is formed along the moving body passage 38b in order to reduce radial damage to the tension medium 40 caused by the rolling elements 36. That is, a circumferential groove 26 b is formed on the inner surface of the clamp 46 and the inner periphery of the housing 26. The tension medium 40 is accommodated in the groove 26b, and the rolling element 36 is moved in direct contact with the moving body passage 38b. Thereby, it is avoided that the tension medium 40 is sandwiched between the rolling element 36 and the moving body passage 38b.
[0079]
36 to 38 described above, the groove 26b is formed on the inner surface of the movable body passage 38b of the housing 26 and the clamp 48. Thereby, the damage received by the tension medium 40 is reduced.
[0080]
If necessary, the groove 26b can be coated or coated with resin, rubber, gel, or the like to further reduce damage to the tensile medium.
[0081]
FIG. 42 shows an example in which damage to the tension medium 40 by the rolling elements 36 is reduced. In this example, an impact absorbing member 41 is provided between the leading rolling element 36 and the tension medium 40. The impact absorbing member 41 absorbs and relaxes the impact exerted on the tension medium 40 by the rolling elements 36 extruded by the rapid gas expansion caused by the ignition of the explosive. The shock absorbing member 41 is made of resin, rubber or the like.
[0082]
43 and 44 show an example in which the movement of the rolling element 36 in the rotational direction is stabilized. 43 is a cross-sectional view of the pretensioner, and FIG. 44 is a cross-sectional view in the GG direction of FIG. In this example, a spacer 43 is provided between the rolling element 36 and the tension medium 40. The intermediate member 43 is a belt-shaped thin film that is in contact with the outer periphery of the rolling element, and is disposed inside the pipe 74 and along the drawing medium 40. Thereby, a rolling element is smoothly moved to a rotation direction. The intermediate member 43 is formed of a flexible material such as a stainless plate, a steel plate, or a high-strength resin that absorbs an impact.
[0083]
Next, another example of the pushing member 42 will be described.
[0084]
In the example of the extruded member shown in FIG. 45, two elastic portions 42e are formed on the upper surface (rolling element side) of the prismatic seal member 42b. The elastic part 42e is made of an elastic body such as rubber, plastic, resin, etc., and is composed of two protrusions formed in parallel to each other corresponding to the round rolling element 36. The elastic portion 42e suppresses the movement of the rolling element 36 in the vehicle traveling direction due to the vibration of the vehicle, and prevents the generation of sound.
[0085]
In the example of the pushing member shown in FIGS. 46 and 47, a plurality of annular protrusions 42f that make a round around the outer periphery are formed on the outer periphery of the pushing member 42 that is in close contact with the inner surface (cylinder portion) of the pipe 74. When the pushing member 42 is inserted into the cylinder of the pipe 74, the annular protrusion 42f is crushed and deformed, and the adhesion between the pushing member 42 and the cylinder is improved.
[0086]
The extruded member shown in FIGS. 48 to 50 includes a vent hole. A through-hole (narrow tube) 42g is formed between the upper surface and the lower surface of the pushing member 42 shown in FIG. Further, a slit 42h is formed on the upper surface so as to create a gap for allowing the residual pressure gas to escape between the rolling element 36 and the opening of the through hole 42g.
[0087]
FIG. 49 is a perspective view for explaining an example of the pushing member 42 having such a thin tube. In this example, the pushing member 42 includes a sealing member 42b and an upper member 42i. The seal member 42b has a space (through hole) formed in a cylindrical shape in the vertical direction of the central portion. The upper member 42i is a member having a “T” -shaped longitudinal section in which a slit 42h is formed on the upper surface and a cylindrical projection is formed in the center of the lower surface. A through-hole (narrow tube) 42g extending from the center of the slit 42h to the lower surface of the protrusion is formed. The upper member 42i is formed of, for example, metal or heat-resistant plastic (resin). The seal member 42b is also formed of a heat resistant elastic body. The cylindrical protrusion is fitted into the through-hole of the seal member 42b, and the push-out member 42 with a thin tube is assembled.
[0088]
FIG. 50 is a diagram illustrating the function of the thin tube 42g. As described above, in a state where the retractor shaft 24 is twisted and the webbing can be pulled out, the rolling element 36 moves back into the cylinder. When the pushing member 42 tries to return toward the initial position, the residual pressure of the combustion gas in the expansion chamber 30 prevents the pushing member 42 from returning. Therefore, the residual pressure gas is discharged from the gas vent slit 42h to the cylinder side through the narrow tube 42g of the pushing member 42, so that the rolling elements 36 and the pushing member 42 are returned smoothly.
[0089]
FIG. 52 is a cross-sectional view illustrating an example in which the pushing member 42 shown in FIG. 12 is combined with the example of the pretensioner using the pipe shown in FIG.
[0090]
In this example, the linear passage of the rolling element 36 is constituted by a pipe 74 and is a cylinder having the pushing member 42 as a piston. The cylinder plays a role of moving the rolling elements while maintaining the gas pressure. The push-out member 42 is constituted by a square piston (plate) 42a and a seal member 42b corresponding to the pipe 74 having a square cross section. A hole 42c is formed in the center of the seal member 42b. The seal member 42b is made of plastic such as rubber or resin. The piston 42a is selected to be harder (rigid body) than the sealing member 42b such as iron or hard plastic. As described with reference to FIGS. 13 and 14, in this example as well, the sealing performance against gas leakage in the linear passage 38 a when the rolling element 36 is moved by deforming the pushing member 42 by the gas pressure is improved.
[0091]
Further, as shown in FIG. 53, the extruded member 42 in which a protruding portion (conical frustum portion) 42d having a taper at the center portion of the piston 42a shown in FIGS. 15 and 16 is formed on the extruded member in the pipe. Can be used. Also in this case, the sealing member 42b is pushed outward from the center by the taper of the protrusion 42d, and the sealing performance of gas leakage is improved.
[0092]
In the embodiment shown in FIGS. 17 to 20, a covering 40a can be formed by casting in order to improve the biting of the clamp 46 at one end portion of the tension medium 40.
[0093]
Further, other modifications are not prevented from being added to the above-described embodiment.
【The invention's effect】
As described above, the seatbelt device including the pretensioner according to the present invention moves the moving body by applying pressure to the moving body that is movably accommodated in a passage provided in the housing or the pipe. A pressure applying device to be engaged, a speed increasing mechanism by a pulling medium that engages the moving body and is drawn out more than a moving distance of the moving body, changes the moving body movement into a circular movement and generates a rotating torque, and a rotating torque. A clutch device that transmits to the take-up shaft and rotates the take-up shaft in the webbing take-up direction. The amount of rotation of the retractor shaft is generated, and the webbing take-up function equivalent to that when the stroke length is long is obtained, while the overall structure is downsized and simplified. Te, it is possible to reduce the manufacturing cost facilitated the vehicle.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view of a retractor device of a seat belt device as viewed from the outside in the retractor axial direction.
FIG. 2 is a cross-sectional view illustrating a pretensioner provided in the retractor device.
FIG. 3 is an exploded perspective view illustrating a clutch 44 used in a pretensioner.
FIG. 4 is an explanatory diagram for explaining an initial state of a clutch 44;
FIG. 5 is an explanatory diagram for explaining an operation (connection) state of a clutch 44;
FIG. 6 is an explanatory diagram for explaining an initial state of a rolling element.
FIG. 7 is an explanatory diagram for explaining the movement of a rolling element and the operation of a clutch 44;
8 is an explanatory diagram for explaining an initial state of the rolling element 36 and a clamping operation of the clamp 46. FIG.
9 is an explanatory diagram for explaining the return position of the rolling element 36 and the release of the clamp of the clamp 46. FIG.
FIG. 10 is an explanatory view for explaining a rolling element 36;
FIG. 11 is an explanatory diagram for explaining an example of a leading rolling element.
12 is a cross-sectional view for explaining an example of another pushing member 42. FIG.
13 is a cross-sectional view illustrating an example (an initial state) of another pushing member 42. FIG.
14 is a cross-sectional view illustrating an example (operation state) of another pushing member 42. FIG.
FIG. 15 is a cross-sectional view illustrating still another example (initial state) of the pushing member 42;
16 is a cross-sectional view illustrating an example (operation state) of still another push-out member 42. FIG.
FIG. 17 is an explanatory diagram for explaining an example of a pretensioner using one moving body 64;
FIG. 18 is an explanatory diagram for explaining an example in which a pretensioner using a moving body 64 operates.
FIG. 19 is an explanatory diagram for explaining a clamped state by a moving body.
FIG. 20 is an explanatory diagram for explaining a clamp release state by a moving body.
FIG. 21 is an explanatory diagram illustrating an example of a moving object.
22 is an explanatory diagram for explaining a partial cross section of a moving body 64. FIG.
FIG. 23 is an explanatory diagram for explaining a dimension example of the pushing member 62;
24 is an explanatory diagram for explaining a dimension example of a circulation passage 38a of the moving body 64. FIG.
FIG. 25 is a partial cross-sectional view of an example in which a pipe is used for the pretensioner of the retractor device as viewed from the outside in the retractor axial direction.
FIG. 26 is a cross-sectional view illustrating an example of a pretensioner using an L-shaped pipe.
FIG. 27 is a perspective view illustrating an L-shaped pipe.
FIG. 28 is a sectional view in the axial direction of an L-shaped pipe.
FIG. 29 is an exploded perspective view illustrating the clutch 44;
30 is an explanatory diagram for explaining the operation of the clutch 44; FIG.
FIG. 31 is an explanatory diagram for explaining the operation of the clutch 44;
FIG. 32 is an explanatory diagram for explaining the operation of the clutch 44;
FIG. 33 is an explanatory diagram for explaining the operation of the clutch 44;
FIG. 34 is an explanatory diagram for explaining the clamp 46 and the covering 40a of the tension medium 40;
FIG. 35 is an explanatory diagram for explaining the operation of the clamp 46;
FIG. 36 is an explanatory view illustrating an example of a clamp 48 using this principle as a clamp.
FIG. 37 is an explanatory diagram for explaining the operation of the clamp 48;
FIG. 38 is an explanatory diagram for explaining the operation of the clamp 48;
39 is a perspective view showing an example in which a hollow (cylindrical) roller is used as the rolling element 36. FIG.
FIG. 40 is an explanatory diagram illustrating an example in which a tension medium is stored in a groove.
41 is a cross-sectional view in the AA direction of FIG. 40 for explaining an example in which the tension medium 40 is accommodated in the groove.
42 is an explanatory view illustrating an example in which an impact relaxation member 41 is provided between the tension medium 40 and a rolling element (moving body) 36. FIG.
FIG. 43 is an explanatory diagram for explaining an example in which a spacer 43 is provided to smoothly move the rolling elements along the rolling element passage.
44 is a cross-sectional view in the BB direction of FIG. 43. FIG.
FIG. 45 is a perspective view illustrating an example of an extrusion member that reduces rattling of the rolling elements.
FIG. 46 is a perspective view for explaining an example in which a plurality of protrusions surrounding the periphery of the extruded member are formed to enhance the sealing effect.
FIG. 47 is an explanatory diagram illustrating a sealing effect due to deformation of a protrusion.
48 is a perspective view for explaining an example in which a gas vent hole is formed in the pushing member to release the residual pressure in the pipe and the rolling element 36 can be easily returned. FIG.
FIG. 49 is a perspective view illustrating an assembly example of an extrusion member having a gas vent hole.
FIG. 50 is an explanatory diagram for explaining the operation of an extrusion member having a gas vent hole.
FIG. 51 is an explanatory diagram for explaining a dimensional relationship between an extruded member and a pipe.
FIG. 52 is an explanatory diagram for explaining an example in which a pipe and a seal member that spreads outward by gas pressure are combined.
FIG. 53 is an explanatory view illustrating an example in which a pipe and a seal member in which the seal member spreads outward by a tapered protrusion are combined.
[Explanation of symbols]
10 Retractor
12 Pretensioner
24 Retractor shaft
26 Housing
28 Lid
32 Pressurized gas generator (pressure application device)
36 Rolling elements
38 Mobile passage
38a Moving body passage (cylinder part)
40 Tensile media
42 Extruded member
44 Clutch device
46 Clamp member
64 mobile
62 Extruded member

Claims (3)

A housing including a pressure chamber and a moving body passage communicating with the pressure chamber;
A pressure applying device that is provided in the housing and generates high-pressure gas in the pressure chamber;
A moving body disposed in the moving body passage;
An extruding member that moves the moving body under the high pressure;
When the outer periphery rotates in one direction and is arranged coaxially with the retractor shaft, a clutch connected to the retractor shaft;
A tension medium attached at one end to the outer periphery of the clutch and wound around the clutch, and the other end engaged with the movable body and attached to the housing;
A seat belt device comprising a retractor including a pretensioner mechanism, wherein the other end of the tension medium is fixed by a clamp whose release is restricted by an arrangement position of the moving body. A pipe including a pressure chamber and a moving body passage communicating with the pressure chamber;
A pressure applying device that is provided in the pipe and generates high-pressure gas in the pressure chamber;
A housing fixing the pipe;
A moving body disposed in the moving body passage;
An extruding member that moves the moving body under the high pressure;
When the outer periphery rotates in one direction and is arranged coaxially with the retractor shaft, a clutch connected to the retractor shaft;
A tension medium attached at one end to the outer periphery of the clutch and wound around the clutch, and the other end engaged with the movable body and attached to the housing;
A seat belt device comprising a retractor including a pretensioner mechanism, wherein the other end of the tension medium is fixed by a clamp whose release is restricted by an arrangement position of the moving body. A housing including a pressure chamber and a moving body passage communicating with the pressure chamber;
A pressure applying device that is provided in the housing and generates high-pressure gas in the pressure chamber;
A moving body disposed in the moving body passage;
An extruding member that moves the moving body under the high pressure;
When the outer periphery rotates in one direction and is arranged coaxially with the retractor shaft, a clutch connected to the retractor shaft;
A tension medium attached at one end to the outer periphery of the clutch and wound around the clutch, and the other end engaged with the movable body and attached to the housing;
The moving body passageway is formed so as to surround the clutch substantially on the circumference of a circle centered on the retractor shaft, wherein the movable body is formed of a single body of a shape conforming to the moving body passageway, the pretensioner mechanism A seatbelt device comprising a retractor including:

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