Crew protection devices

Abstract

In a configuration where an airbag is provided in a seat belt equipped with a heater, the present invention provides an occupant protection device that can efficiently transfer heat emitted from the heater to the occupant. [Solution] The occupant protection device 10 comprises a seat belt 11, a heater 80 attached to the seat belt 11 that generates heat when an electric current is applied, an airbag 30 attached to the seat belt 11 in a folded state and configured to inflate when an inflation gas is supplied to catch the occupant M, the airbag 30 being positioned away from the occupant M relative to the heater 80 when the seat belt 11 is fitted to the occupant M, and a heat-reflective film 78 positioned between the heater 80 and the folded airbag 30 in the thickness direction of the seat belt 11, which reflects the heat emitted from the heater 80.

Description

Technical Field

[0001] The present invention relates to an occupant protection device that protects an occupant sitting on a vehicle seat.

Background Art

[0002] Conventionally, as an occupant protection device that protects an occupant sitting on a vehicle seat, a seat belt that restrains the occupant to the seat is widely known. Further, in Patent Document 1, a configuration is described in which an airbag is provided in a lap belt portion that restrains the waist of the occupant in the seat belt, and the occupant is received and protected by the airbag.

[0003] Also, in Patent Document 2, a configuration is described in which a heater is provided in the lap belt portion of the seat belt, and the heater warms the vicinity of the waist of the occupant wearing the seat belt.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, a configuration in which an airbag is provided in a seat belt provided with a heater by combining the configurations of Patent Document 1 and Patent Document 2 can be considered. Thereby, while warming the occupant wearing the seat belt with the heater, the occupant can be received and protected by the airbag. However, when such a configuration is adopted, there is a possibility that the heat of the heater escapes to the airbag side and the heat is not efficiently transmitted to the occupant.

[0006] Therefore, the present invention aims to provide an occupant protection device in which an airbag is provided in a seat belt equipped with a heater, which can efficiently transfer heat emitted from the heater to the occupant. [Means for solving the problem]

[0007] A typical configuration of the occupant protection device according to the present invention for solving the above problems is an occupant protection device for protecting an occupant seated in a seat, comprising: a seat belt that restrains the occupant to the seat; a heater attached to the seat belt that generates heat when an electric current is passed through it; an airbag attached to the seat belt in a folded state and configured to inflate when an inflation gas is supplied to catch the occupant, the airbag positioned away from the occupant relative to the heater when the seat belt is fitted to the occupant; an inflator that releases the inflation gas supplied to the airbag; and a heat reflecting member positioned between the heater and the folded airbag in the thickness direction of the seat belt, which reflects the heat emitted from the heater.

[0008] According to the present invention, in an occupant protection device in which an airbag is provided in a seat belt equipped with a heater, the heat emitted from the heater can be efficiently transferred to the occupant. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of the seat. [Figure 2] This is a left side view of the seat. [Figure 3] This is a front view of the seat with the occupant seated and wearing the seatbelt. [Figure 4] This is a cross-section of an airbag unit and a seat belt. [Figure 5] This is a front view of the seat with the airbag inflated. [Figure 6]This is a left side view of the seat with the airbag inflated. [Figure 7] This is a perspective view of an airbag unit in an inflated state. [Figure 8] This is a cross-sectional view of a modified airbag unit. [Modes for carrying out the invention]

[0010] The following describes an occupant protection device 10 according to one embodiment of the present invention. Note that the dimensions, materials, shapes, and relative arrangements of the components described below are not intended to limit the scope of this invention to those unless specifically stated otherwise.

[0011] Furthermore, in the following explanation, the left-right direction refers to the left and right directions of the seat 1 where occupant M, who is the protected person of the occupant protection device 10, is seated, specifically the left and right directions as seen from occupant M seated on seat 1. The front-rear direction refers to the front and rear directions of seat 1, specifically the front and rear directions as seen from occupant M seated on seat 1. The up-down direction refers to the upward and downward directions in the vertical direction.

[0012] The occupant protection device 10 protects occupant M, who is seated in seat 1 of the vehicle 50, by catching them with an airbag 30. Figure 1 is a perspective view of seat 1. Figure 2 is a left side view of seat 1, showing occupant M seated in seat 1 with seat belt 11 fastened by a dashed line. Figure 3 is a front view of seat 1 with occupant M seated and seat belt 11 fastened. Figure 4 is a cross-sectional view of the airbag unit 70 and seat belt 11 cut along the AA section shown in Figure 3.

[0013] As shown in Figures 1 to 4, the occupant protection device 10 comprises a seat belt 11, an airbag unit 70 attached to the seat belt 11 and including an airbag 30, and an inflator 24 that supplies inflation gas to the airbag 30. The occupant protection device 10 also comprises a control device 22 that controls the operation of the inflator 24, and an acceleration sensor 21 used for detecting collisions of the vehicle 50.

[0014] The seat belt 11 is a belt-like member that restrains the occupant M to the seat 1, and in this embodiment, it is formed of a synthetic fiber such as nylon. The seat belt 11 is configured to be able to be drawn out from a winding mechanism 15 provided inside the vicinity of the upper left edge of the backrest portion 1a of the seat 1. The lower end portion of the seat belt 11 is fixed to an anchor member 17 provided on the left side of the seat portion 1b of the seat 1.

[0015] A tongue 18 is attached to an intermediate portion of the seat belt 11. The tongue 18 is fastened to a buckle 19 provided on the right side of the seat portion 1b of the seat 1. The state where the occupant M is seated on the seat 1 and the tongue 18 is fastened to the buckle 19 is the state where the seat belt 11 is worn by the occupant M. Incidentally, the occupant M can release the fastening of the tongue 18 to the buckle 19 by pressing a release button (not shown) provided on the buckle 19 and remove the tongue 18 from the buckle 19.

[0016] The winding mechanism 15 has a pretensioner mechanism 16 configured to stop the drawing out in the case of a sudden draw out of the seat belt 11 and to wind up the drawn out seat belt 11 in the event of a collision of the vehicle 50 or the like. The pretensioner mechanism 16 winds up the seat belt 11 by rotating the shaft around which the seat belt 11 is wound by operating a built-in gas generator (not shown).

[0017] The seat belt 11 in the state of being worn by the occupant M extends from the tongue 18 toward the winding mechanism 15 side, is disposed in front of the upper body MU of the occupant M, and has a shoulder belt portion 12 configured to restrain the upper body MU, and extends from the tongue 18 toward the anchor member 17 side, is disposed in front of the waist MW of the occupant M, and has a lap belt portion 13 configured to restrain the waist MW.

[0018] The lap belt portion 13 has a passenger side surface 13a disposed on the passenger M side and a counter-passenger side surface 13b which is the surface on the opposite side of the passenger side surface 13a in a state where the seat belt 11 is worn by the passenger M. Since the lap belt portion 13 is a part of the seat belt 11, the passenger side surface 13a of the lap belt portion 13 can also be said to be the passenger side surface of the seat belt 11. Similarly, the counter-passenger side surface 13b of the lap belt portion 13 can also be said to be the counter-passenger side surface of the seat belt 11.

[0019] A heater 80 that generates heat by being energized is attached to the passenger side surface 13a of the lap belt portion 13 via a heater cover 81. The heater 80 of the present embodiment is a flexible rectangular sheet-like carbon heater using carbon fiber, and is arranged such that the direction in which the long side of the rectangle extends is along the longitudinal direction of the lap belt portion 13. That is, the longitudinal direction of the lap belt portion 13 and the longitudinal direction of the heater 80 are the same direction. Note that the type and shape of the heater 80 are not limited to this, and other ones may be used.

[0020] The heater cover 81 is made of an insulator, and is configured to cover a passenger side surface 80a which is the surface on the passenger M side of the heater 80 in a state where the seat belt 11 is worn by the passenger M, and an end face 80c in the width direction that is orthogonal to the longitudinal direction and the thickness direction of the heater 80. The heater cover 81 is connected to the lap belt portion 13 by a portion covering the end face 80c of the heater 80 being sewn to the passenger side surface 13a of the lap belt portion 13. The heater 80 attached to the lap belt portion 13 in this way has its passenger side surface 80a and end face 80c in the width direction covered by the heater cover 81, and the counter-passenger side surface 80b opposite to the passenger side surface 80a is covered by the lap belt portion 13. Note that the heater cover 81 of the present embodiment is formed of synthetic fiber which is the same material as the lap belt portion 13, whereby the heater 80 and the heater cover 81 are less conspicuous in appearance.

[0021] Furthermore, wires (not shown) are connected to both ends of the heater 80 in the longitudinal direction, electrically connecting the heater 80 to the control device 22. The heater 80 receives power from a power source (not shown) mounted on the vehicle 50 via these wires, and receives control signals from the control device 22. In this embodiment, the heater 80 is attached to the occupant side 13a of the lap belt section 13, but it is also possible to attach the heater 80 to the opposite occupant side 13b of the lap belt section 13 in the same manner as described above. However, since the heat from the heater 80 is more easily transferred to the occupant M when the heater 80 is closer to the occupant M, it is preferable to attach the heater 80 to the occupant side 13a of the lap belt section 13 as in this embodiment.

[0022] The acceleration sensor 21 is mounted on the front bumper (not shown) of the vehicle 50 and detects the impact caused by collisions, etc., of the vehicle 50 as acceleration. The control unit 22 (control unit) is configured with a CPU, memory, etc., and is mounted in a predetermined location inside the vehicle 50. The control unit 22 is electrically connected to the acceleration sensor 21, the inflator 24, the pretensioner mechanism 16, thermistor 75 (Figure 7), which will be described later, and the heater 80. The control unit 22 transmits operating signals to the inflator 24 and the pretensioner mechanism 16 according to the detection result of the acceleration sensor 21.

[0023] Furthermore, the control device 22 controls the power supplied to the heater 80 so that the temperature detected by the thermistor 75 becomes the target temperature stored in a memory (not shown). The occupant M can switch the heater 80 on and off and set the target temperature of the heater 80 by operating an operation unit (not shown) mounted on the vehicle 50.

[0024] The inflator 24 consists of a roughly cylindrical gas generating section 24a that generates expansion gas internally, and a tubular pipe section 24b that guides the expansion gas released from the gas generating section 24a to the airbag 30. The gas generating section 24a is attached to the rear surface of the seat frame 1c that supports the seat portion 1b of the seat 1 by bolts (not shown) or the like. The pipe section 24b extends to the left from the gas generating section 24a and is bent in a roughly L-shape along the side surface from the bottom of the seat portion 1b. The inflator 24 is activated and generates expansion gas when an operation signal is input from the control device 22.

[0025] Next, the configuration of the airbag unit 70 will be described. Figure 5 is a front view of the seat 1 with the airbag 30 inflated. Figure 6 is a left side view of the seat 1 with the airbag 30 inflated. In Figures 5 and 6, the occupant M, seated in the seat 1 and fastened with the seat belt 11, is shown by a dashed line. Figure 7 is a perspective view of the airbag unit 70 with the airbag 30 inflated, and the airbag cover 73 of the airbag unit 70 is omitted.

[0026] As shown in Figures 4 to 7, the airbag unit 70 includes an airbag 30, a bag connecting portion 72 that connects the airbag 30 to the wrap belt portion 13, a heat reflective film 78 that reflects heat emitted from the heater 80, a thermistor 75, and an airbag cover 73 that covers the folded airbag 30 and bag connecting portion 72, etc.

[0027] The airbag 30 comprises a bag body 30a configured to inflate and deploy to catch the occupant M when inflation gas is supplied, and a conduit 30b that guides the inflation gas released from the inflator 24 to the inlet 30a3a of the bag body 30a. Before inflation gas is supplied, the bag body 30a is folded and housed inside the airbag cover 73 (see Figure 3). The bag body 30a is made of a base fabric for bags, which is a woven fabric formed by plain weaving polyester fibers.

[0028] When inflation is complete, the bag body 30a is positioned directly in front of the occupant M and facing the occupant M, and has a rear wall portion 30a1 that contacts and supports the occupant M's upper body MU as it moves forward, and a front wall portion 30a2 positioned on the front side opposite to the rear wall portion 30a1. Furthermore, when inflation is complete, the bag body 30a has a lower wall portion 30a3 positioned on the bottom and supported by the occupant M's thigh portion MF, a left wall portion 30a4 positioned on the left side, and a right wall portion 30a5 positioned on the right side. The lower wall portion 30a3 of the bag body 30a is provided with two inlets 30a3a, which are openings for allowing the inflation gas from the conduit portion 30b to flow in.

[0029] The conduit section 30b is a cylindrical member that extends along the longitudinal direction of the wrap belt section 13 and is made of the same bag base fabric as the bag body section 30a. One end 30b2 of the conduit section 30b in the longitudinal direction is connected to the pipe section 24b of the inflator 24, and the other end 30b3 is connected to the inlet 30a3a of the bag body section 30a.

[0030] Specifically, one end 30b2 of the conduit section 30b and the pipe section 24b of the inflator 24 are fastened together with a clamp 27, thereby connecting them in a way that prevents the expansion gas from leaking out. In addition, a communication port 30b1 is formed at the other end 30b3 of the conduit section 30b, which is an opening that communicates with the inlet 30a3a of the bag body section 30a. The periphery of the inlet 30a3a of the bag body section 30a and the periphery of the communication port 30b1 of the conduit section 30b are sewn together, so that the other end 30b3 of the conduit section 30b and the bag body section 30a are connected with the inlet 30a3a and the communication port 30b1 in communication. As a result, the expansion gas released from the inflator 24 into the conduit section 30b of the airbag 30 flows into the inside of the bag body section 30a via the communication port 30b1 and the inlet 30a3a.

[0031] The bag connecting portion 72 is a member that connects the wrap belt portion 13 with the airbag 30 and the heat-reflective film 78. In this embodiment, it is made of the same base fabric as the base fabric for the bag that forms the airbag 30. The bag connecting portion 72 is a through-hole that penetrates along its longitudinal direction and has a belt insertion portion 72a through which the wrap belt portion 13 is inserted, and a film storage portion 72b that houses the heat-reflective film 78. The film storage portion 72b is a tubular portion that extends along the longitudinal direction of the bag connecting portion 72, and both ends in the longitudinal direction are sealed by sewing together the base fabrics that constitute the bag connecting portion 72. The upper surface of the bag connecting portion 72 is also sewn to the lower surface of the conduit portion 30b of the airbag 30. With this configuration, the airbag 30 and the heat-reflective film 78 are connected to the wrap belt portion 13 via the bag connecting portion 72. The longitudinal direction of the bag connecting portion 72 and the longitudinal direction of the wrap belt portion 13 are the same.

[0032] Furthermore, a thermistor 75 (temperature detection unit) for detecting temperature is provided inside the belt insertion portion 72a of the bag connecting portion 72. The temperature information detected by the thermistor 75 is input to the control device 22 which is electrically connected to the thermistor 75. Alternatively, another type of temperature sensor may be used instead of the thermistor 75.

[0033] With the airbag 30, heat-reflective film 78, and heater 80 connected to the lap belt section 13 as described above, their positional relationships are as follows. That is, when the seat belt 11 is fastened to the occupant M, the heater 80 is positioned on the side of the lap belt section 13 where the occupant M is located, and the airbag 30 is positioned on the opposite side of the lap belt section 13 from where the occupant M is located. Also, when the seat belt 11 is fastened to the occupant M, the airbag 30 is positioned on the side of the heater 80 away from the occupant M. These positional relationships are based on the thickness direction of the lap belt section 13.

[0034] Furthermore, in the thickness direction of the lap belt portion 13, the heat reflective film 78 is positioned between the heater 80 and the folded airbag 30. In this embodiment, since the heater 80 is attached to the occupant side 13a of the lap belt portion 13, it can also be said that the heat reflective film 78 is positioned between the lap belt portion 13 and the folded airbag 30. The thermistor 75 is positioned so as to overlap with the heat reflective film 78 and the heater 80 when viewed from the thickness direction of the lap belt portion 13.

[0035] The heat-reflective film 78 (heat-reflective member) is a member that has the property of reflecting heat. In this embodiment, the heat-reflective film 78 is made of a flexible rectangular film made of aluminum, and the direction in which the longer side of the rectangle extends is aligned with the longitudinal direction of the wrap belt portion 13. Furthermore, in the width direction perpendicular to the longitudinal direction and thickness direction of the wrap belt portion 13, the width L1 of the heat-reflective film 78 is wider than the width L2 of the wrap belt portion 13. Note that the longitudinal direction, thickness direction, and width direction of the wrap belt portion 13 are the same as the longitudinal direction, thickness direction, and width direction of the heat-reflective film 78.

[0036] The heat emitted from the heater 80 is reflected towards the occupant M by the heat-reflective film 78. The heat-reflective film 78 is not limited to an aluminum film; any film with heat-reflective properties may be used, such as a synthetic resin film made of polyester. Alternatively, another non-film-like material with heat-reflective properties may be used as the heat-reflective element instead of the heat-reflective film 78.

[0037] The airbag cover 73 is a cylindrical member attached to the wrap belt portion 13, and in this embodiment, it is made of the same base fabric as the base fabric for the bag that forms the airbag 30. The airbag cover 73 houses the entire bag body portion 30a, a part of the conduit portion 30b, the entire bag connecting portion 72, the entire heat reflective film 78, and a part of the wrap belt portion 13 of the folded airbag 30 inside the cylinder. When the bag body portion 30a inflates, the airbag cover 73 receives pressure from the bag body portion 30a and ruptures to form an opening, allowing the bag body portion 30a to be unfurled through this opening.

[0038] Next, the occupant protection operation of the occupant protection device 10 will be described. First, when the vehicle 50 collides, the acceleration sensor 21 detects this collision as acceleration. If the acceleration detected by the acceleration sensor 21 is above a predetermined level, the control device 22 determines that the vehicle 50 has collided and sends an operation signal to the inflator 24 and the pretensioner mechanism 16.

[0039] Next, the pretensioner mechanism 16 is activated, and the seat belt 11 attached to occupant M is retracted by the pretensioner mechanism 16. As a result, the lap belt portion 13 of the seat belt 11 is pulled towards the tongue 18 and the shoulder belt portion 12 is pulled towards occupant M's shoulder, stabilizing occupant M's seated position.

[0040] Next, the inflator 24 activates and releases inflation gas, which is supplied to the bag body 30a via the conduit 30b of the airbag 30. This causes the bag body 30a to inflate. Subsequently, the upper body MU of occupant M, which moves forward due to the impact of the collision with the vehicle 50, is caught by the bag body 30a. In this way, the occupant protection device 10 protects occupant M.

[0041] In this embodiment, as described above, the heat-reflective film 78 is positioned between the heater 80 and the folded airbag 30 in the thickness direction of the lap belt portion 13. With this configuration, the heat emitted from the heater 80 is reflected towards the occupant M by the heat-reflective film 78, and the escape of heat towards the airbag 30 is suppressed. Therefore, according to the configuration of this embodiment, in an occupant protection device 10 equipped with an airbag 30 on a seat belt 11 with a heater 80, the heat emitted from the heater 80 can be efficiently transferred to the occupant M.

[0042] Furthermore, in the width direction of the lap belt portion 13, the width L1 of the heat reflective film 78 is wider than the width L2 of the lap belt portion 13. As a result, even if the lap belt portion 13 or the heat reflective film 78 shifts in the width direction inside the belt insertion portion 72a or film storage portion 72b of the bag connecting portion 72, the lap belt portion 13 is more likely to be positioned to overlap with the heat reflective film 78 when viewed from the thickness direction of the lap belt portion 13, thus making it easier for the heat from the heater 80 attached to the lap belt portion 13 to be reflected towards the occupant M by the heat reflective film 78.

[0043] Furthermore, the thermistor 75 is positioned so as to overlap with the heat-reflective film 78 and the heater 80 when viewed from the thickness direction of the lap belt section 13. This allows the thermistor 75 to detect the temperature of the parts of the heat-reflective film 78 that are prone to temperature increases due to heat reflection, thereby controlling the heater 80 and preventing the body temperature of the occupant M from rising too high due to the heat from the heater 80.

[0044] In this embodiment, a configuration has been described in which a film storage section 72b is provided in the bag connecting section 72 and the heat reflective film 78 is stored in this film storage section 72b. However, the present invention is not limited to this configuration. That is, as long as the heat reflective film 78 is positioned between the heater 80 and the airbag 30, the same effects as described above can be obtained even if the heat reflective film 78 is stored in another position.

[0045] For example, as shown in Figure 8A, the heat-reflective film 78 may be attached to the upper surface of the belt insertion portion 72a of the bag connecting portion 72 by adhesive or stitching. Alternatively, as shown in Figure 8B, the heat-reflective film 78 may be attached to the lower surface of the conduit portion 30b of the airbag 30 by adhesive or stitching. Figures 8A and 8B are cross-sectional views of modified airbag units 70, respectively.

[0046] Furthermore, although this embodiment describes a configuration in which an airbag 30, heater 80, and heat-reflective film 78 are provided on the lap belt portion 13 of the seat belt 11, the present invention is not limited to this. That is, the same effects can be obtained by attaching the heater 80 and airbag unit 70 to the shoulder belt portion 12 of the seat belt 11 in the same manner as described above.

[0047] Furthermore, although the occupant protection device 10 has been described using a so-called three-point seat belt 11, which comprises a shoulder belt portion 12 and a lap belt portion 13, as an example in this embodiment, the present invention is not limited thereto. That is, even if the present invention is applied to a so-called two-point seat belt 11, which has a lap belt portion 13 but does not have a shoulder belt portion 12, the same effects as described above can be obtained. [Explanation of Symbols]

[0048] 1...Seat, 10...Occupant protection device, 11...Seat belt, 13...Wrap belt section, 22...Control device (control unit), 24...Inflator, 30...Airbag, 30a...Bag body section, 30b...Conduit section, 75...Thermistor (temperature detection section), 78...Heat reflective film (heat reflective material), 80...Heater, M...Occupant, MW...Waist section

Claims

1. In an occupant protection device that protects an occupant seated in a seat, A seat belt that restrains the occupant to the seat, A heater attached to the aforementioned seat belt, which generates heat when electricity is passed through it, An airbag that is attached to the seat belt in a folded state and is configured to inflate when an inflation gas is supplied to catch the occupant, wherein the airbag is positioned on the side away from the occupant relative to the heater when the seat belt is fastened to the occupant, An inflator that releases the inflation gas supplied to the airbag, A heat reflective member is positioned in the thickness direction of the seat belt between the heater and the folded airbag, and reflects the heat emitted from the heater. A occupant protection device characterized by being equipped with the following features.

2. With respect to the seat belt in the state in which it is attached to the occupant, the heater is positioned on the side where the occupant is located, and the folded airbag is positioned on the opposite side from where the occupant is located. The occupant protection device according to claim 1, characterized in that the heat reflective member is positioned between the seat belt and the folded airbag.

3. The occupant protection device according to claim 1, characterized in that, in the width direction of the seat belt perpendicular to the longitudinal direction and the thickness direction of the seat belt, the width of the heat reflective member is wider than the width of the seat belt.

4. The occupant protection device according to claim 1, characterized in that the heat reflective member is attached to the airbag.

5. A temperature detection unit that detects temperature, A control unit that controls the heater based on the detection result of the temperature detection unit, Furthermore, The occupant protection device according to claim 1, characterized in that the temperature detection unit is positioned to overlap with the heat reflective member and the heater when viewed from the thickness direction of the seat belt.

6. The occupant protection device according to claim 1, characterized in that the heat reflective member is made of a metal film.

7. The occupant protection device according to claim 1, characterized in that the heat reflective member is made of a synthetic resin film.

8. The seat belt has a lap belt portion configured to restrain the occupant's waist, The occupant protection device according to any one of claims 1 to 7, characterized in that the heater and the airbag are attached to the lap belt portion.

9. The airbag comprises a bag body configured to inflate and catch the occupant when the inflation gas is supplied, and a conduit connected to the inflator, which guides the inflation gas released from the inflator to the bag body. The occupant protection device according to claim 8, characterized in that the heat reflective member is positioned between the heater and the conduit in the thickness direction of the lap belt portion.

Images