Seatbelt retractor system

Abstract

To provide a retractor system for seat belt that can correspond to restraint performance of various conditions depending on a crewman with a relatively simple configuration.SOLUTION: A retractor system for seat belt comprises a retractor having a first energy absorption mechanism that can deliver a webbing while absorbing energy when a load exceeding a specified value is added to the webbing, and comprises an additional energy absorption mechanism which can deliver a webbing onto a webbing crawl path extended from the retractor while absorbing energy when a load exceeding a second specified value different from the specified value is added to the webbing. The additional energy absorption mechanism is independent from the first energy absorption mechanism, and can be selectively operated.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a seat belt retractor system including a retractor having an energy absorption mechanism that enables the webbing to be unwound while absorbing energy when a load exceeding a predetermined value is applied to the webbing. [Background technology]

[0002] Conventionally, a retractor provided in a vehicle seatbelt device winds and unwinds a webbing (seatbelt) by rotating a spindle, and in the event of a vehicle collision, a locking mechanism locks the rotation of the spindle to prevent the webbing from unwinding. Meanwhile, when the impact force of a collision is extremely large, the tension in the webbing increases over time after the collision, increasing the load on the occupant from the webbing. Therefore, the retractor is provided with an energy absorption mechanism that absorbs energy and unwinds a predetermined amount of the webbing when the load acting on the webbing exceeds a predetermined value, thereby reducing the strain on the occupant's chest (see, for example, Patent Documents 1 and 2).

[0003] Various types of load limiters (force limiters) have been proposed as energy absorption mechanisms for retractors. For example, the simplest and most representative type (hereinafter referred to as "LL" or "LL load limiter") has a torsion bar (energy absorption member) inside a spindle around which the webbing is wound, with one end of the torsion bar connected to a locking member. When the locking member is locked, the spindle rotates in response to the tension on the webbing, causing the torsion bar to twist. The torsion bar then twists due to plastic deformation, absorbing energy. There is also a type (hereinafter referred to as "LLS") that has a stopper on the LL to forcibly stop the LL. Still another type (hereinafter referred to as "LLD" or "two-stage load limiter") has a bending element on the LL that increases the load limiter load (energy absorption load) through friction (friction) of the bending element in the early stages of a collision, and then releases the bending element's friction in the later stages of the collision, allowing the LL to function as a normal LL (energy absorption by a torsion bar) (hereinafter referred to as "LLD" or "two-stage load limiter"). There are also types (hereinafter referred to as "LLA" or "variable load limiter") that are equipped with a torque tube or the like in the LL, and that set a high load limiter load when the occupant is large, and a low load limiter load when the occupant is small. For example, in an LLA, if the default load limiter load is set to a high load, and if a small occupant is detected, an MGG (micro gas generator) is activated at the moment of collision, switching to a low load limiter load. There are also types (hereinafter referred to as "LLDS" or "LLAS") that combine an LLS with an LLD or LLA. Furthermore, the LLS, LLD, and LLA can be combined with each other, and there are also types that combine all of these.

[0004] The energy absorption mechanism described in Patent Document 2 is an LLA type that uses two torsion bars with different shaft diameters. The load limiter load can be switched between two stages, with a thick torsion bar setting a high load limiter load and a thin torsion bar setting a low load limiter load. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-250529 [Patent Document 2] International Publication No. 2016 / 063634 Summary of the Invention [Problem to be solved by the invention]

[0006] Occupants vary not only in weight and physique, but also in skeletal strength and internal organ resistance levels. If the load limiter load could be adjusted in more than two stages, it would be possible to accommodate a wider range of occupants, further improving occupant restraint performance. However, a system that adjusts the load limiter load continuously would be complex. In addition, the system that controls the webbing withdrawal speed would also be complex.

[0007] An object of the present invention is to provide a seat belt retractor system that has a relatively simple configuration and is capable of responding to a variety of restraint performance conditions depending on the occupant. [Means for solving the problem]

[0008] A seat belt retractor according to one embodiment of the present invention is a seat belt retractor system including a retractor having a first energy absorption mechanism that enables the webbing to be unwound while absorbing energy when a load exceeding a predetermined value is applied to the webbing, and an additional energy absorption mechanism that enables the webbing to be unwound while absorbing energy when a load exceeding a second predetermined value different from the predetermined value is applied to the webbing on a routing path of the webbing extended from the retractor, and the additional energy absorption mechanism is configured to be operable independently of and selectively operable from the first energy absorption mechanism.

[0009] According to this aspect, it is possible to select whether or not to operate the additional energy absorption mechanism, and when operating the additional energy absorption mechanism, the additional energy absorption mechanism can be operated independently of the first energy absorption mechanism. When the additional energy absorption mechanism is not operated, the energy absorption load is the energy absorption load of the first energy absorption mechanism. On the other hand, when the additional energy absorption mechanism is operated, the corresponding energy absorption load can be added to the energy absorption load of the first energy absorption mechanism. This means that if the first energy absorption mechanism can switch the energy absorption load in two stages, the switchable energy absorption load can be set to at least four stages. Therefore, with a relatively simple configuration, it is possible to respond to various conditions of restraint performance depending on the occupant. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing an example of a seat of a vehicle equipped with a seat belt retractor system according to an embodiment; [Figure 2] 2 is a view showing a seat belt assembly including a retractor and a clamp EA in the seat belt retractor system of FIG. 1. FIG. [Figure 3]1A and 1B are diagrams showing an LLA load limiter, which is an example of an energy absorption mechanism for a retractor. FIG. 1A shows the load transmission path when the load limiter load is set to a high value, and FIG. 1B shows the load transmission path when the load limiter load is set to a low value. [Figure 4] FIG. 10 is a perspective view showing an example in which the clamp EA according to the first embodiment is fixed to a retractor frame. [Figure 5] FIG. 2 is a perspective view showing a state in which parts constituting the clamp EA according to the first embodiment are disassembled, together with a retractor. [Figure 6] FIG. 2 is a perspective view showing a state in which a clamp frame is removed from the clamp EA according to the first embodiment, together with a retractor. [Figure 7] FIG. 10 is a cross-sectional view of the clamp EA according to the first embodiment in an initial position, taken along a line passing through the shaft of the clamp member. [Figure 8] FIG. 1 is a cross-sectional view of the clamp EA according to the first embodiment in an initial position, taken along a line passing through the center (shear pin) of the clamp member. [Figure 9] 1A to 1C are schematic diagrams showing an outline of the operation of the clamp EA according to the first embodiment, in which (a) is an initial position, (b) is the start of operation, and (c) is a diagram showing energy absorption. [Figure 10] 5A and 5B are cross-sectional views showing details of the operation of the clamp EA according to the first embodiment, in which (a) is an initial position, (b) is the start of operation, (c) is during energy absorption, and (d) is after energy absorption (clamp release). [Figure 11] FIG. 3 is a diagram showing an outline of combinations of load limiter loads in the retractor system according to the first embodiment. [Figure 12] 12 is a diagram showing an outline of a load acting on a webbing in the case of each load limiter load of FIG. 11. FIG. [Figure 13] 13 is a diagram showing an outline of a load acting on a webbing when an LLD is used instead of the LLA load limiter of FIG. 12. FIG. [Figure 14] 10A and 10B are diagrams illustrating a clamp EA according to a second embodiment. [Figure 15]FIG. 10 is a diagram showing an outline of a clamp EA according to a third embodiment. [Figure 16] FIG. 11 is a diagram showing an outline of combinations of load limiter loads in the retractor system according to the third embodiment. [Figure 17] FIG. 11 is a perspective view showing a state in which parts constituting a clamp EA according to a third embodiment are disassembled, together with a retractor. [Figure 18] FIG. 11 is a front view of a state in which a clamp EA according to a third embodiment is fixed to a retractor frame. [Figure 19] 19 is a cross-sectional view taken along the line AA in FIG. 18. [Figure 20] 10A and 10B are cross-sectional views showing the operation flow of the clamp EA according to the third embodiment, in which (a) shows the start of operation, (b) shows energy absorption, and (c) shows after energy absorption (clamp release). [Figure 21] An enlarged oblique view showing the clutch disengagement operation of the clamp EA in the third embodiment, where (a) shows the initial position (clutch engaged state), (b) shows the point immediately after a frontal collision of the vehicle, and (c) shows a point a short time after (b). DETAILED DESCRIPTION OF THE INVENTION

[0011] A preferred embodiment of the present invention will be described with reference to the accompanying drawings.

[0012] In this document, up / down, left / right, and front / rear are defined as follows: When an occupant is seated in a seat (vehicle seat) in a normal posture, the direction the occupant is facing is referred to as forward, and the opposite direction is referred to as backward, and when indicating the axes of coordinates, these are referred to as the front / rear direction. Also, when an occupant is seated in a vehicle seat in a normal posture, the right side of the occupant is referred to as the right direction, and the left side of the occupant is referred to as the left direction, and when indicating the axes of coordinates, these are referred to as the left / right direction. Similarly, when an occupant is seated in a normal posture, the direction of the occupant's head is referred to as upward, and the direction of the occupant's waist is referred to as downward, and when indicating the axes of coordinates, these are referred to as the up / down direction.

[0013] Additionally, EA stands for energy absorption. EA load is an abbreviation for energy absorption load, and is synonymous with load limiter load or force limiter load. EA load refers to the limit load (the load that limits the withdrawal of the webbing) that indicates the limit amount of the load acting on the webbing.

[0014] [Vehicle seat] 1 is a diagram showing an example of a vehicle seat 1. The vehicle seat 1 may be a front seat (i.e., a driver's seat or a passenger seat) or a rear seat. The vehicle seat 1 includes a seat back 2 that supports the back of an occupant, a seat cushion 3 on which the occupant sits, and a headrest 4 that supports the head of the occupant.

[0015] As is well known, a vehicle can be equipped with sensors and systems that detect an occupant seated in a vehicle seat 1. For example, a weight sensor 5 that detects the weight of the occupant can be provided on the seat cushion 3. Also, a physique sensor 6 (such as a strain gauge) that detects the physique of the occupant (adult, child, etc.) can be provided on the seat cushion 3. Also, a camera 7 that captures an image of the occupant can be provided, and the weight and / or physique of the occupant can be detected by analyzing the image generated by the camera 7 with a control device 8 (ECU).

[0016] The control device 8 is configured as, for example, a microcomputer and includes a CPU, memory, and an input / output interface. The CPU executes desired calculations according to a control program and performs various processes and controls. The memory includes, for example, a ROM and a RAM. The ROM stores the control program and control data processed by the CPU, and the RAM is mainly used as various work areas for control processes. In addition to the weight sensor 5, the body size sensor 6, and the camera 7, a collision sensor 9 that detects a vehicle collision and various actuators (actuator 55 and LPAs 161, 761, and 861, which will be described later) are electrically connected to the input / output interface. The collision sensor 9 is for detecting a vehicle collision and may be any of various known types, such as an acceleration sensor or a pressure sensor.

[0017] The control device 8 determines the weight and / or physique of the occupant seated in the vehicle seat 1 based on information from sensing devices such as the weight sensor 5, the physique sensor 6, or the camera 7. Depending on the determination result, the control device 8 selects one of a plurality of selectable EA loads as the EA load for restraining the occupant. Then, when the control device 8 receives an input signal from the collision sensor 9, that is, in the event of a vehicle emergency (when it determines whether or not the vehicle has experienced a frontal collision and determines that a frontal collision has occurred), it controls the seat belt assembly 10 (retractor 20, clamp EA 30) so that the selected EA load is applied.

[0018] [Seatbelt assembly] A seat belt assembly 10 is associated with a vehicle seat 1. The seat belt assembly 10 includes a webbing 11, which is a seat belt that restrains an occupant. The webbing 11 includes a shoulder belt portion 14 that extends from an upper guide loop or anchorage 12 to a tongue 13 and a lap belt portion 16 that extends from the tongue 13 to an anchorage 15. The tongue 13 may include a loop portion 17 through which the webbing 11 extends. The tongue 13 is configured to be insertable into a buckle 18 to lock and unlock the seat belt assembly 10. A cable 19 of the buckle 18 secures the buckle 18 to a portion of the vehicle structure (e.g., the vehicle frame) directly or in cooperation with other components. When the tongue 13 is inserted into the buckle 18 and fastened, the seat belt assembly 10 defines a three-point restraint between the anchorage 12, the tongue 13, and the anchorage 15.

[0019] As shown in FIGS. 1 and 2, the seat belt assembly 10 also includes a retractor 20 and a clamp EA30.

[0020] [Retractor] The retractor 20 can basically have a known configuration. The retractor 20 is configured to be able to retract the webbing 11, thereby making it possible to adjust the effective length of the webbing 11. The retractor 20 is positioned within the vehicle seat 1 or structurally coupled to the vehicle body.

[0021] As shown in FIG. 2, the retractor 20 has a retractor frame 21 and a spindle 22 rotatably housed in the retractor frame 21. The spindle 22 engages with the shoulder belt portion 14 of the webbing 11 and rotates to wind or unwind the webbing 11. The spindle 22 biases the webbing 11 in the winding direction by a power spring, an electric motor, or the like. Meanwhile, an end of the lap belt portion 16 of the webbing 11 is fixed to an anchorage 15 (for example, the retractor frame 21, the vehicle seat 1, or another part of the vehicle such as a floor pan).

[0022] The retractor 20 has a pretensioner 40, a locking mechanism, and a torsion bar. Known structures can also be used for the pretensioner 40, the locking mechanism, and the torsion bar. An example will be described.

[0023] The pretensioner 40 is activated, for example, in the event of a vehicle emergency, and pulls the webbing 11 by rotating the spindle 22 in a direction to retract the webbing 11, thereby removing slack in the webbing 11. One example of the pretensioner 40 has a rod that is movable within a gas tube 42 and a gas generator 44 (micro gas generator (MGG)) at the end of the gas tube 42. The gas generator 44 is electrically connected to the control device 8 and is activated in response to a signal from the control device 8 that detects a vehicle emergency situation. With this configuration, the pretensioner 40 activates the gas generator 44 in the event of a vehicle emergency, causing the generated gas to move the rod within the gas tube 42, engaging the tip of the rod with the spindle 22 directly or via another member, and rotating the spindle 22 in the retraction direction. As a result, the webbing 11 is retracted, removing slack therein and reducing forward movement or displacement of the occupant.

[0024] As is well known, the locking mechanism locks the rotation of the spindle 22 by limiting the rotation of the locking member (locking the locking member) when, for example, the vehicle decelerates at a predetermined rate or the brakes are applied with a predetermined force, thereby stopping the unwinding of the webbing 11. The locking mechanism also locks the rotation of the spindle 22 in the event of a vehicle emergency. As a result, the occupant is secured to the vehicle seat 1. Note that during normal vehicle operation, the retractor 20 allows the webbing 11 to be unwound, giving the occupant a certain degree of freedom of movement, and the webbing 11 may become slack during normal use.

[0025] As is well known, the torsion bar constitutes an energy absorption mechanism (load limiter) that maintains the restraining force of the webbing 11 applied to the occupant at a constant level during a frontal collision of the vehicle. For example, in an LL load limiter, the torsion bar is disposed inside the spindle 22, one end connected to the spindle 22, and the other end connected to a lock member of a locking mechanism. When the lock member locks during a frontal collision of the vehicle, rotation of the spindle 22 is locked. However, when the occupant is displaced forward within the vehicle cabin due to inertia, the tensile load acting on the webbing 11 increases. When this load exceeds a predetermined value, the spindle 22 rotates in response to the tension on the webbing 11, thereby twisting the torsion bar. When the torsion bar twists due to plastic deformation, energy is absorbed and the impact on the occupant's chest is alleviated. That is, the retractor 20 has an energy absorption mechanism 24 that enables the webbing 11 to be unwound while absorbing energy when a load exceeding a predetermined value is applied to the webbing 11.

[0026] [LLA Load Limiter (Energy Absorption Mechanism)] 3 shows an LLA load limiter 50, which is another example of the energy absorption mechanism 24. As described above, the LLA load limiter 50 is an LL load limiter to which a torque tube 57 and the like are additionally provided, and the load limiter load can be set in two stages. For example, the LLA load limiter 50 can be set to a high load limiter load when the occupant is large, and can be set to a low load limiter load when the occupant is small. The LLA load limiter 50 is also a known configuration, so the following will only briefly describe an overview of the configuration and the load transmission path.

[0027] First, in the LLA load limiter 50, a thick torsion bar 51 and a thin torsion bar 52 are connected in series. One end of the thick torsion bar 51 is connected to a tread head 53. The spindle 22 is connected at two points: one end of the thin torsion bar 52 and a connection portion 54 between the thick torsion bar 51 and the thin torsion bar 52. An actuator 55 selects whether the connection portion 54 is connected or disconnected, thereby switching the load (torque).

[0028] As shown in FIG. 3(A), when a high load limiter load (a high predetermined value) is set, the webbing 11 is also connected to the spindle 22 at the connection portion 54. In this case, the tensile load acting on the webbing 11 is transmitted, in order, to the spindle 22, the locking member 56, the torque tube 57, the thick torsion bar 51, and the tread head 53. At this time, the thick torsion bar 51 is twisted by the tensile load acting on the webbing 11, and energy is absorbed. On the other hand, as shown in FIG. 3(B), when a low load limiter load (a low predetermined value) is set, the connection portion 54 is separated from the spindle 22. In this case, the tensile load acting on the webbing 11 is transmitted to the spindle 22, the thin torsion bar 52, the thick torsion bar 51, and the tread head 53. At this time, only the thin torsion bar 52 is twisted by the tensile load acting on the webbing 11, and energy is absorbed.

[0029] In the LLA load limiter 50, for example, a high load limiter load is set as a default. In the default setting, the actuator 55 is not activated. The actuator 55 is activated by an activation signal from the control device 8, and may be, for example, a micro gas generator using explosives. In the LLA load limiter 50, if it is determined that the weight or physique of the occupant is small, the load limiter is set to switch to a low load limiter load. This is achieved by activating the actuator 55 at the moment of a frontal collision, thereby separating the connection portion 54 from the spindle 22.

[0030] [Clamp EA Overview] 2 again, the retractor system of this embodiment includes a clamp EA30 in addition to a retractor 20 having an energy absorption mechanism 24. The energy absorption mechanism 24 is, for example, an LLA load limiter 50. However, known energy absorption mechanisms such as LL, LLS, LLD, LLDS, and LLAS can also be used for the energy absorption mechanism 24.

[0031] The clamp EA30 is an additional energy absorption mechanism provided on the crawling path 60 of the webbing 11 extended from the retractor 20. Like the energy absorption mechanism 24 of the retractor 20, the clamp EA30 enables the webbing 11 to be paid out while absorbing energy when a load exceeding a certain set value is applied to the webbing 11. However, this set value (second predetermined value) is different from the set value (first predetermined value, such as the above-mentioned high load limiter load and low load limiter load) in the energy absorption mechanism 24. Furthermore, the clamp EA30 is configured to be able to be selectively operated independently of the energy absorption mechanism 24 (details will be described later).

[0032] The routing path 60 for the webbing 11 includes a first path 61 along which the webbing 11 extends from the retractor 20 in a first direction (here, upward), an anchorage 12 (through anchor) that is provided at an end of the first path 61 and that can guide the webbing 11 so as to fold back in a second direction (here, downward or diagonally downward), and a second path 62 along which the folded back webbing 11 extends. The clamp EA30 is provided on the first path 61 and is located between the retractor 20 and the anchorage 12. In this case, the clamp EA30 may be structurally fixed to the vehicle body at a position separated from the retractor 20. Alternatively, the clamp EA30 may be attached to a frame extension portion that extends from the retractor frame 21 in the first direction (here, upward). An example in which the clamp EA30 is fixed to the retractor frame 21 will be described below.

[0033] [First embodiment] [Clamp EA Details] 4 shows an example in which the clamp EA30 is fixed to the retractor frame 21. The clamp EA30 is fixed to the upper part of the retractor frame 21 so as to protrude upward from the retractor 20.

[0034] FIG. 5 is an exploded perspective view of the parts that make up the clamp EA30. FIG. 6 shows the clamp EA30 with the clamp frame 110 removed. Also, FIGS. 7 and 8 are cross-sectional views of the clamp EA30 in the initial position (when the clamp EA30 is not operating). Of these, FIG. 7 is a cross-sectional view taken at a position that passes through the shaft portion 133 of the clamp member 130, and FIG. 8 is a cross-sectional view taken at a position that passes through the center (shear pin 136) of the clamp member 130. The configuration of the clamp EA30 will be described below, mainly with reference to FIG. 5. Please refer to FIGS. 4 and 6 to 8 as appropriate.

[0035] The clamp EA30 includes a clamp frame 110 (mounting frame), a lower plate 120 (receiving member), a clamp member 130, a bar member 140 (connecting member), an EA plate 150 (energy absorbing member), an actuator unit 160, a lever 170, a guide 180, and a pin 190.

[0036] The clamp frame 110 has opposing side walls 111a, 111b and a bottom wall 112 connecting the side walls. The side walls 111a, 111b are formed with guide holes 113a, 113b extending in the vertical direction, as well as mounting holes 114, 115, and 116 for mounting various parts. Both ends of a bar member 140 are inserted into the guide holes 113a, 113b. Both ends of an EA plate 150 are fixed to the mounting holes 114, 114. Both ends of a pin 190 are journaled in the mounting holes 115, 115. The mounting holes 116, 116 are used to fasten the clamp EA30 to the retractor frame 21. That is, the clamp EA30 is attached to the retractor frame 21 via the clamp frame 110. A plate 118 having a webbing insertion hole 117 formed therein is attached to the upper ends of the side walls 111a, 111b and the bottom wall 112. The webbing insertion hole 117 is formed in the shape of a horizontally long slit, through which the webbing 11 is inserted (see FIG. 7).

[0037] The lower plate 120 has fixing holes 121 and 122 at diagonal positions. The lower plate 120 is fixed to the bottom wall 112 of the clamp frame 110 via the fixing holes 121 and 122. The lower plate 120 also has two regions 123 and 124, each having a different plate thickness, on the side opposite the bottom wall 112. The thin region 124 is located above the thick region 123, and has a thin surface on the side facing the clamp member 130.

[0038] The clamp member 130 has a wedge-shaped structure made up of a pressing surface 131 and a guide surface 132, and has a pair of shafts 133, 133 on the side opposite to the tip of the wedge. A number of locking protrusions 135 that can be locked onto the webbing 11 are formed on the pressing surface 131 (see FIG. 7). The guide surface 132 faces the bar member 140. The guide surface 132 is configured to be slidable on a guide surface 142 of the bar member 140.

[0039] A shear pin 136 protrudes from the center of the guide surface 132. The shear pin 136 is inserted into the bar member 140 (see FIG. 8). The shear pin 136 is broken by a shear force acting when the clamp member 130 starts to slide relative to the bar member 140. That is, before the clamp member 130 starts to slide, the shear pin 136 holds the clamp member 130 to the bar member 140. When a force is input to the shaft portion 133 from the outside, the shear pin 136 breaks, allowing the clamp member 130 to slide relative to the bar member 140 (see FIG. 9).

[0040] The bar member 140 has a flat fixed surface 141 and an inclined guide surface 142 on the opposite side to the fixed surface 141. A plurality of (four in this example) fixing holes 143 are formed in the fixed surface 141. The fixed surface 141 faces the EA plate 150 and is fixed to the EA plate 150 via the fixing holes 143. The guide surface 142 faces the guide surface 132 of the clamp member 130 and guides the movement of the clamp member 130 toward the webbing 11 (see FIG. 7).

[0041] The bar member 140 is also movable in the vertical direction within the range of the vertical length of the guide holes 113a, 113b of the clamp frame 110. In the initial position, the lower end 144 of the bar member 140 abuts against the lower ends of the guide holes 113a, 113b. When the bar member 140 moves upward, it is guided by the guide holes 113a, 113b and moves upward along them. When the upper end 145 of the bar member 140 abuts against the upper ends of the guide holes 113a, 113b, the movement of the bar member 140 is restricted.

[0042] The EA plate 150 is formed into a predetermined shape by, for example, bending a metal plate, and has a U-shaped portion 151. The U-shaped portion 151 has a flat fixing portion 152 and a pair of curved portions 153, 153. The fixing portion 152 is fixed to the fixing surface 141 of the bar member 140. One end of each of the pair of curved portions 153, 153 is connected to both sides of the lower end of the fixing portion 152, and extends upward in a U-shape from there, with the other end connected to a flat bridge portion 154. The bridge portion 154 is parallel to the fixing portion 152 and located above it. Side pieces 155, 155 are formed on both sides of the bridge portion 154, bent toward the opposite side from the fixing portion 152. A fixing hole 156 is formed through the side piece 155. Furthermore, a hook piece 157 is formed facing outward at the upper end of the side piece 155. The EA plate 150 is fixed by aligning the fixing holes 156 with the mounting holes 114 of the side walls 111 a and 111 b, and the hook pieces 157 are hooked onto the upper ends of the side walls 111 a and 111 b. In the EA plate 150, the pair of curved portions 153 plastically deform to absorb energy.

[0043] The actuator unit 160 includes an LPA (Linear Pilot Actuator) 161, which is an actuator, a housing 162, and a piston 163. The LPA 161 is a drive source for actuating the clamp EA30, and may be, for example, an electromagnetic actuator or a pyrotechnic actuator. The LPA 161 is actuated by receiving an actuation signal from the control device 8. The housing 162 houses the LPA 161 and the piston 163 below it in its cylindrical interior. The piston 163 moves downward within the housing 162 due to actuation of the LPA 161. In the initial position, the lower end of the piston 163 faces or abuts against a lever 170 (see FIG. 8). When the piston 163 moves downward due to actuation of the LPA 161, the piston 163 inputs a force to the lever 170, causing the lever 170 to rotate.

[0044] The lever 170 has a contact portion 171, an input portion 172, and a rotating shaft portion 173. The contact portion 171 contacts the piston 163 and receives a force from the piston 163. The input portion 172 is provided on the opposite side of the rotating shaft portion 173 from the contact portion 171. There are a pair of input portions 172, each of which contacts the shaft portion 133 of the clamp member 130 and inputs a force to the shaft portion 133 to move the clamp member 130. There are a pair of rotating shaft portions 173, each of which has a pin 190 inserted through its center. Both ends of the pin 190 are supported by the side walls 111a, 111b of the clamp frame 110. Therefore, the lever 170 is supported by the clamp frame 110 so as to be rotatable around the rotating shaft portion 173 (pin 190).

[0045] The guide 180 has a webbing insertion slit 181 and an insertion shaft 182. The webbing insertion slit 181 is formed in a horizontally long slit shape, and the webbing 11 is inserted through it (see FIG. 7). The webbing insertion slit 181 guides the webbing 11 immediately after it has been unwound from the retractor 20. Three insertion shafts 182 are formed at intervals from one another. The rotation shaft 173 of the lever 170 is located in the space between adjacent insertion shafts 182. A pin 190 is inserted through the center of the insertion shaft 182. The guide 180 is fixed by inserting a tip end 183, which is on the opposite side to the insertion shaft 182, into the bottom wall 112 of the clamp frame 110. Therefore, the guide 180 is fixed to the clamp frame 110 via the tip end 183 and the insertion shaft 182 (pin 190).

[0046] [Outline of operation of clamp EA30] 9A and 9B are schematic diagrams showing an outline of the operation of the clamp EA 30. In the initial position shown in FIG.

[0047] As shown in FIG. 9(b), when the LPA 161 is actuated, the lever 170 is rotated via the piston 163. Then, the clamp member 130 is pushed in by the lever 170, and its movement toward the webbing 11 is guided by the guide surface 142 of the bar member 140. At this time, the shear pin 136 breaks. When the clamp member 130 moves toward the webbing 11, the locking projection 135 locks onto (pierces) the webbing 11. As a result, the locking projection 135 is fixed to the webbing 11.

[0048] Thereafter, the clamp member 130 fixed to the webbing 11 via the locking projection 135 attempts to move in the direction of arrow 200 as shown in FIG. 9( c) due to the tension of the webbing 11 (the force in the direction of being pulled out from the spindle 22). The webbing tension applied to the clamp member 130 acts from the guide surface 132 of the clamp member 130 to the guide surface 142 of the bar member 140, and attempts to move the bar member 140 in the direction of arrow 200. As a result, the U-shaped portion 151 (curved portion 153) of the EA plate 150 connected to the bar member 140 is plastically deformed, and the clamp member 130 and the bar member 140 move together in the direction of arrow 200. As a result, the energy acting on the webbing 11 is absorbed by the EA plate 150, and the webbing 11 is unwound.

[0049] In this way, the EA plate 150 is switched from the non-energy absorbing mode (see FIG. 9(a)) to the energy absorbing mode (see FIG. 9(c)) by the operation of the LPA 161. When the clamp EA30 is selected to be deactivated, the LPA 161 is not activated, and the EA plate 150 is maintained in the non-energy absorbing mode (see FIG. 9(a)). In the non-energy absorbing mode, the locking projection 135 is separated from the webbing 11 as described above, and therefore the locking projection 135 does not affect the webbing 11.

[0050] [Details of the operation of the EA30 clamp] Next, the operation of the clamp EA30 will be described in detail with reference to FIG.

[0051] 10(a), the locking projection 135 of the clamp member 130 is spaced apart from the webbing 11. The bar member 140 is positioned on the lower side of the guide hole 113a. The EA plate 150 is in the non-energy absorbing mode.

[0052] FIG. 10(b) shows the time when the LPA 161 is actuated. When the LPA 161 is actuated, the piston 163 moves downward, causing the lever 170 to rotate. When the lever 170 rotates, the input portion 172 of the lever 170 abuts against the shaft portion 133 of the clamp member 130, causing the clamp member 130 to move. The clamp member 130 is guided by the guide surface 142 of the bar member 140 in its upward movement toward the webbing 11, and the locking projection 135 locks onto (pierces) the webbing 11 and is fixed. In other words, the clamp EA30 clamps the webbing 11. At this time, the locking projection 135 faces the thick-walled region 123 of the lower plate 120, with the webbing 11 sandwiched therebetween.

[0053] FIG. 10(c) shows the EA plate 150 in the energy-absorbing mode absorbing energy. In the position shown in FIG. 10(c), the clamp member 130 is moved away from the input portion 172 of the lever 170, and the bar member 140 is moved to a vertically intermediate position in the guide hole 113a. This is because the tension of the webbing 11 in the direction of the arrow 210 causes the clamp member 130 to move together with the bar member 140 in the direction of the arrow 210. As this movement occurs, the U-shaped portion 151 (curved portion 153) of the EA plate 150 connected to the bar member 140 is pulled in the direction of the arrow 210 and plastically deforms. The location of the plastic deformation shifts on the U-shaped portion 151 as the bar member 140 moves. During this plastic deformation, the webbing 11 is unwound while energy is absorbed. As the energy absorption by the EA plate 150 progresses, the portion of the locking projection 135 that faces the lower plate 120 with the webbing 11 sandwiched therebetween transitions from the thick region 123 to the thin region 124.

[0054] FIG. 10(d) shows the point in time when the clamp EA30 reaches the stroke end. The tension of the webbing 11 in the direction of arrow 210 causes the bar member 140 to abut against the upper end of the guide hole 113a, restricting its movement. Energy absorption by the EA plate 150 ends. All of the locking projections 135 have moved to positions facing the thin-walled regions 124, sandwiching the webbing 11. Therefore, when tension is applied to the webbing 11 in the direction of arrow 210, the webbing 11 disengages from the lower plate 120, and the locking projections 135 come off the webbing 11. Because the webbing 11 is caught on the tip of the locking projection 135, the stress in the locking projection 135 changes from shear stress to bending stress and increases. The locking projection 135 cannot withstand the bending stress and breaks. This causes the clamp EA30 to release the webbing 11 and unclamp.

[0055] As can be understood from the above description, in the lower plate 120, the thick region 123 (first region) sandwiches the webbing 11 and the clamp member 130 that is locked to the webbing 11, and the thin region 124 (second region) is located in the payout direction of the webbing 11 from the thick region 123, and promotes a tendency to release the locking of the clamp member 130 to the webbing 11. If the thin region 124 were not provided in the lower plate 120, the locking projection 135 would not come off the webbing 11 and would not break. In this case, although energy absorption by the EA plate 150 stops at the stroke end, the clamp is not released.

[0056] 10, the clamp EA30 is operated independently of the energy absorption mechanism 24 of the retractor 20. This means that the operation of one of the clamp EA30 and the energy absorption mechanism 24 is performed without affecting the operation of the other.

[0057] Furthermore, it is possible to select whether to activate the clamp EA30 or not (deactivate it). This selection is made by the control device 8 of FIG. 1 according to the weight, physique, etc. of the occupant. When it is selected to activate the clamp EA30, the LPA 161 is activated in the event of a frontal collision of the vehicle, and the EA plate 150 is shifted to the energy absorbing mode. On the other hand, when it is selected not to activate the clamp EA30, the LPA 161 is not activated in the event of a frontal collision of the vehicle, and the EA plate 150 is maintained in the energy non-absorbing mode. In this case, the clamp EA30 does not affect the winding / releasing of the webbing 11. In other words, the clamp EA30 does not come into contact with the webbing 11 in a way that would change the winding force / withdrawal force. Naturally, the clamp EA30 allows the webbing 11 to be paid out without affecting the action (energy absorption) of the energy absorption mechanism 24.

[0058] [Load limiter load combination summary] 11 is a diagram showing an overview of the combinations of load limiter loads in the retractor system according to this embodiment. Here, an example is shown in which an LLA load limiter 50 is used as the energy absorption mechanism 24 of the retractor 20. The LLA load limiter 50 allows the load limiter load to be selected in two stages, and it is possible to select whether or not to activate the clamp EA30. Therefore, a total of four load limiter loads can be selected (2 stages x 2 stages).

[0059] FIG. 11(a) shows a combination of a high load limiter load due to the thick torsion bar 51 and the load limiter load when the clamp EA30 is activated. FIG. 11(b) shows a combination of a high load limiter load due to the thick torsion bar 51 when the clamp EA30 is not activated. Similarly, FIG. 11(c) shows a combination of a low load limiter load due to the thin torsion bar 52 and the load limiter load when the clamp EA30 is activated. FIG. 11(d) shows a combination of a low load limiter load due to the thin torsion bar 52 when the clamp EA30 is not activated. It will be understood that when the clamp EA30 is activated, the load limiter load due to the clamp EA30 is added to the load limiter load due to the energy absorption mechanism 24.

[0060] FIG. 12 is a diagram showing an overview of the load acting on the webbing 11 for each load limiter load in FIG. 11. In FIG. 12, solid lines indicate cases where the clamp EA30 is not activated, and dashed lines indicate cases where the clamp EA30 is activated. For reference, FIG. 12 also shows a case where a stopper is provided on the LLA load limiter 50. The stopper can be provided to forcibly stop the LLA load limiter 50 to prevent the occupant from moving too far forward during a collision. It can be understood that a forcible stop results in a higher load acting on the webbing 11.

[0061] Fig. 13 is a diagram showing an overview of the load acting on the webbing 11 when an LLD is used instead of the LLA load limiter 50. As in Fig. 12, in Fig. 13, the solid line indicates the case when the clamp EA30 is not activated, and the dashed line indicates the case when the clamp EA30 is activated. For reference, a case where a stopper is provided on the LLD is also shown. As in the case of the LLA load limiter 50, it will be understood that when the clamp EA30 is activated, an additional load is added to the load limiter load due to the LLS (energy absorption mechanism 24).

[0062] As described above, the retractor system according to this embodiment includes the retractor 20 having the energy absorption mechanism 24, as well as the clamp EA30 (additional energy absorption mechanism) that can be selectively activated independently of the energy absorption mechanism 24. This allows a selection of multiple loads to restrain the occupant with a relatively simple configuration, and can accommodate a variety of restraint performance conditions depending on the occupant. In particular, the control device 8 can select in advance whether to activate or deactivate the clamp EA30 depending on the occupant's weight, physique, etc., and can restrain the occupant with a load appropriate for the occupant's weight, physique, etc. in the event of a frontal collision of the vehicle.

[0063] Next, other embodiments will be described. The other embodiments will be described mainly focusing on the differences from the first embodiment, and the same or similar reference numerals will be used to designate the same components as the first embodiment, and the description thereof will be omitted.

[0064] [Second embodiment] 14 is a diagram showing a clamp EA300 according to the second embodiment. The clamp EA300 uses a torsion bar 310 as an energy absorption member instead of the above-described EA plate 150. One end of the torsion bar 310 is connected to a pinion gear 320, and the other end is connected to a fixed element such as the clamp frame 110. A rack gear 330 meshes with the pinion gear 320, and the rack gear 330 is fixed to the bar member 140. In other words, the torsion bar 310 and the clamp member 130 are actually connected by three connecting members (the pinion gear 320, the rack gear 330, and the bar member 140).

[0065] The torsion bar 310 is switched from a non-energy absorbing mode to an energy absorbing mode by the operation of the LPA 161. When the LPA 161 is operated, the clamp member 130 moves via the lever 170, and the locking projection 135 locks onto the webbing 11. Then, due to the tension of the webbing 11, the clamp member 130, the bar member 140, and the rack gear 330 move upward in the figure, causing the pinion gear 320 to rotate. As a result, a torsion moment acts on one end of the torsion bar 310. When the torsion bar 310 is twisted by plastic deformation, the energy acting on the webbing 11 is absorbed by the torsion bar 310, and the webbing 11 is unwound.

[0066] Here, there may be one torsion bar 310, or there may be multiple torsion bars 310. For example, the pinion gear 320 and the rack gear 330 may be disposed at the center of the clamp frame 110, and the torsion bars 310, 310 may be disposed on both sides of the pinion gear 320. This improves the balance of the load compared to when the torsion bar 310 is provided on only one side of the pinion gear 320. In addition, the thicknesses (diameters) of the torsion bars 310, 310 disposed on both sides of the pinion gear 320 may be different from each other, which allows for subtle torque adjustment.

[0067] [Third embodiment] [Clamp EA Overview] 15 is a diagram showing an outline of a clamp EA400 according to the third embodiment. The clamp EA400 is different from the clamp EA300 according to the second embodiment in that clutches 500 and 600 are added to torsion bars 411 and 412 disposed on both sides of a pinion gear 420.

[0068] The clamp EA400 has a pinion gear 420 and a rack gear 430 at the center of the clamp frame 110, with one end of a thick torsion bar 411 connected to the left half of the pinion gear 420 and one end of a thin torsion bar 412 connected to the right half of the pinion gear 420. The other end of the thick torsion bar 411 is supported by a side wall 111a of the clamp frame 110 via a clutch 500, and the other end of the thin torsion bar 412 is supported by a side wall 111b of the clamp frame 110 via a clutch 600. The clutches 500 and 600 switch the load (torque) on the torsion bars 411 and 412, respectively.

[0069] Specifically, when clutch 500 is engaged, the other end of thick torsion bar 411 is connected to side wall 111a, and rotation of pinion gear 420 causes thick torsion bar 411 to plastically deform and absorb energy. When clutch 500 is disengaged, the other end of thick torsion bar 411 is disengaged from side wall 111a. In this case, even if pinion gear 420 rotates, thick torsion bar 411 is not twisted and does not absorb energy. The same applies to engagement and disengagement of clutch 600, where the other end of thin torsion bar 412 is switched between connection and disconnection with side wall 111b.

[0070] Therefore, the load limiter load that can be selected by clamp EA400 is in four stages (when both clutches 500 and 600 are connected, when only clutch 500 is connected, when only clutch 600 is connected, and when both clutches 500 and 600 are disconnected).

[0071] [Load limiter load combination summary] Fig. 16 is a diagram showing an overview of combinations of load limiter loads in a retractor system according to the third embodiment. As in the case of Fig. 11, an example is shown in which an LLA load limiter 50 is used as the energy absorption mechanism 24 of the retractor 20. The LLA load limiter 50 allows selection of two load limiter load levels, and it is also possible to select whether or not to activate the clamp EA 400, and, if activated, which clutches 500, 600 to disengage (turn ON). Thus, a total of eight load limiter load levels can be selected, with two levels x four levels.

[0072] In FIG. 16 , “ON” and “OFF” mean the following: “OFF” for the LLA load limiter 50 means that a high load limiter load set by default is used; “ON” for the LLA load limiter 50 means that a low load limiter load set by operating the actuator 55 is used; “OFF” for the clamp EA 400 means that the clamp EA 400 is not operated; and “ON” for the clamp EA 400 means that the clamp EA 400 is operated. “ON” for the clutch 500 means that the clutch 500 is operated to separate, i.e., energy absorption by the thick torsion bar 411 is not performed, and a load limiter load by the thin torsion bar 412 is added. “OFF” for the clutch 500 means that the clutch 500 is not operated and remains connected, i.e., a load limiter load by the thick torsion bar 411 is added. The "ON" and "OFF" states of the clutch 600 are the same as those of the clutch 500.

[0073] Here, various mechanisms can be used for the clutches 500, 600. For example, it is possible to use the switching mechanism in the LLA load limiter 50. This type of switching mechanism is already known, but an outline will be described with reference to Figure 17 onwards.

[0074] [Clamp EA Details] Fig. 17 is an exploded perspective view of the parts that make up the clamp EA400. Fig. 18 is a front view of the clamp EA400 fixed to the retractor frame 21, and Fig. 19 is a cross-sectional view taken along line AA in Fig. 18 (a cross-sectional view passing through the center of the clamp EA400). Compared to Fig. 5, Fig. 17 uses a thick torsion bar 411, a thin torsion bar 412, a pinion gear 420, a rack gear 430, clutches 500 and 600, and actuator units 700 and 800. Furthermore, the shapes of the side walls 111a and 111b of the clamp frame 110 have been changed. Specifically, mounting openings 900a and 900b are formed in the side walls 111a and 111b.

[0075] The torsion bars 411, 412 each have a first torque transmission portion 414, 415 at the other end opposite the pinion gear 420. The torsion bars 411, 412 also have a second torque transmission portion 416 that connects the torsion bars 411, 412 to each other at one end on the pinion gear 420 side. The torque transmission portions 414, 415, 416 can be configured in the shape of serrations or splines.

[0076] The pinion gear 420 has a gear portion 421 that meshes with the rack gear 430 at the center of its cylindrical outer periphery. Parts of the torsion bars 411 and 412 are inserted inside the pinion gear 420. A torque transmission portion 422 that is fastened to the second torque transmission portion 416 is formed inside the pinion gear 420 so that the rotational torque of the pinion gear 420 is transmitted to the torsion bars 411 and 412 (see FIG. 19).

[0077] Clutch 500 has a bearing 510, a stopper 520, and a cam plate 530. Clutch 600 has a bearing 610, a stopper 620, and a cam plate 630. Since clutches 500 and 600 have similar configurations, the following description will focus on clutch 500, and for clutch 600, components similar to those of clutch 500 will be assigned the same reference numerals and descriptions thereof will be omitted.

[0078] The bearing 510 has an inner torque transmission portion 511, an outer torque transmission portion 512, and an outer ring portion 513. The inner torque transmission portion 511 and the outer torque transmission portion 512 can be configured in the shape of serrations or splines. The first torque transmission portion 414 of the torsion bar 411 is connected to the inner torque transmission portion 511. The torque transmission portion 521 of the stopper 520 is connected to the outer torque transmission portion 512. The outer ring portion 513 is rotatably supported in the mounting opening 900a of the side wall 111a.

[0079] The stopper 520 is formed in a ring shape as a whole. A torque transmission portion 521 is formed on the inside of the stopper 520, and is connected to the outer torque transmission portion 512 of the bearing 510. A cam groove 522 is formed on the outer peripheral surface of the stopper 520. A pair of cam grooves 522 are formed at positions facing each other across the axis of the stopper 520. In addition, an engaging protrusion 523 is formed on the outer end of the axial direction of the stopper 520. A pair of engaging protrusions 523 are formed at positions facing each other across the axis of the stopper 520. The cam groove 522 and the engaging protrusion 523 are offset from the axis of the stopper 520 by, for example, 90 degrees.

[0080] Cam plate 530 has ring portion 531, cam portion 532, and input receiving portion 533. Bearing 510 and stopper 520 are disposed inside ring portion 531. The outer surface of ring portion 531 abuts against the inner surface of side wall 111a. Cam portion 532 protrudes in the axial direction from the inner peripheral surface of ring portion 531. A pair of cam portions 532 are formed at positions facing each other across the axis of cam plate 530. The pair of cam portions 532, 532, respectively, engage with a pair of cam grooves 522, 522. Input receiving portion 533 protrudes from the outer periphery of ring portion 531. Input receiving portion 533 is configured to be able to input power from actuator unit 700. When this power is input, cam plate 530 receives a rotational force.

[0081] The mounting opening 900a in the side wall 111a has a circular portion 910a and an engagement receiving portion 920a. The bearing 510 is inserted from the outside of the circular portion 910a, and the outer ring portion 513 of the bearing 510 is rotatably supported on the inner circumferential surface of the circular portion 910a. A pair of engagement receiving portions 920 are formed at opposing positions across the center of the mounting opening 900a. A pair of engagement protrusions 523 of the stopper 520 engages with the pair of engagement receiving portions 920a, 920a, respectively, in a disengageable manner.

[0082] The actuator units 700 and 800 are used to disengage the clutches 500 and 600, respectively. The actuator units 700 and 800 are configured similarly to the actuator unit 160, and each include an LPA 761 and 861, a housing 762 and 862, and a piston 763 and 863. The housings 762 and 862 can be provided in the same structure as the housing 162 of the actuator unit 160.

[0083] [When clutch 500, 600 is connected (default setting)] In this case, the load limiter load in the retractor system is the load limiter load due to the energy absorption mechanism 24 of the retractor 20 plus the load limiter loads due to the torsion bars 411 and 412. The LPAs 761 and 861 of the actuator units 700 and 800 are not activated.

[0084] FIG. 20 is a cross-sectional view showing the operation of the clamp EA 400, where (a) shows the start of operation, (b) shows energy absorption, and (c) shows the end of energy absorption (when the clamp EA 400 reaches the stroke end).

[0085] As shown in Figure 20(a) , when the LPA 161 of the actuator unit 160 is activated during a frontal collision of the vehicle, the clamp member 130 moves via the lever 170, and the locking projection 135 locks onto the webbing 11. Then, as shown in Figure 20(b) , the tension of the webbing 11 causes the clamp member 130, bar member 140, and rack gear 430 to move upward in the figure, rotating the pinion gear 420. As a result, a rotational force is transmitted from the second torque transmission portion 416 of the pinion gear 420 to the torque transmission portions 422 at one end of each of the torsion bars 411 and 412.

[0086] Here, the other ends of the torsion bars 411, 412 are fixed to the clamp frame 110 via the bearings 510, 610 and the stoppers 520, 620, and therefore a torsion moment acts on one end of the torsion bars 411, 412. Specifically, the first torque transmission portions 414, 415 of the torsion bars 411, 412 are connected to the inner torque transmission portions 511 of the bearings 510, 610, the outer torque transmission portions 512, 612 of the bearings 510, 610 are connected to the torque transmission portions 521, 621 of the stoppers 520, 620, and the engaging protrusions 523, 623 of the stoppers 520, 620 are engaged with the engaging receiving portions 920a, 920b of the side walls 111a, 111b, and therefore the other ends of the torsion bars 411, 412 are fixed to the clamp frame 110. When a torsion moment acts on one end of the torsion bars 411 and 412 , the torsion bars 411 and 412 are twisted by plastic deformation, and the energy acting on the webbing 11 is absorbed by the torsion bars 411 and 412 .

[0087] Thereafter, as shown in FIG. 20(c), the energy absorption by the clamp EA 400 ends. The operation of ending the energy absorption by the clamp EA 400 and releasing the clamp is the same as in the first embodiment (FIG. 10(d)).

[0088] [When separating the clutch 500] In this case, the load limiter load in the retractor system is the load limiter load due to the torsion bar 412 added to the load limiter load due to the energy absorption mechanism 24 of the retractor 20. The load limiter load due to the torsion bar 411 is not added. The LPA 861 of the actuator unit 800 is not activated.

[0089] Figure 21 is an enlarged oblique view showing the disengagement operation of clutch 500, where (a) shows the initial position (connected state of clutch 500), (b) shows the point immediately after a frontal collision of the vehicle, and (c) shows a point a short time after (b).

[0090] 21(b), during a frontal collision of the vehicle, LPA 761 of actuator unit 700 is activated. Then, piston 763 moves out of housing 762 and abuts against input receiving portion 533 of cam plate 530, causing cam plate 530 to rotate. When cam plate 530 rotates, cam portion 532 of cam plate 530 interferes with cam groove 522 of stopper 520, causing stopper 520 to move in the thrust direction.

[0091] As shown in FIG. 21(c), when cam plate 530 further rotates and stopper 520 moves in the thrust direction, engaging protrusion 523 of stopper 520 disengages from engaging receiver 920a of side wall 111a. This separates (releases) the other end of torsion bar 411 from side wall 111a. Furthermore, torque transmission portion 521 of stopper 520 disengages from and is released from outer torque transmission portion 512 of bearing 510. As a result, torsion bar 411 to which rotational force is input from pinion gear 420 rotates together with bearing 510, and is not twisted and does not absorb the energy acting on webbing 11. In this case, only torsion bar 412 to which rotational force is input from pinion gear 420 is twisted and absorbs the energy.

[0092] Although not described in detail, when the clutch 600 is to be disengaged, the LPA 861 of the actuator unit 800 is actuated.

[0093] As described above, the retractor system according to the third embodiment allows for a greater number of load settings, and can accommodate restraint performance under a wider variety of conditions.

[0094] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The elements included in the embodiments, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those exemplified and can be modified as appropriate.

[0095] For example, in the modified example of the second embodiment, the pinion gear 320 and the rack gear 330 are positioned at the center of the clamp frame 110, and the torsion bars 310, 310 are positioned on both sides of the pinion gear 320, but the pinion gear 320 and the rack gear 330 can also be positioned other than at the center of the clamp frame 110.

[0096] In the third embodiment, the clamp EA 400 is provided with both the first clutch 500 and the second clutch 600, but it may be provided with only one of them.

[0097] Additional Considerations Regarding Various Implementations [Embodiment 1] A seat belt retractor system including a retractor (20) having an energy absorption mechanism (24, 50) that can absorb energy and unwind the webbing (11) when a load exceeding a predetermined value is applied to the webbing (11), an additional energy absorption mechanism (30, 300, 400) that enables the webbing (11) to be unwound while absorbing energy when a load exceeding a second predetermined value different from the predetermined value is applied to the webbing (11) on a routing path (60) of the webbing (11) extended from the retractor (20); The additional energy absorbing mechanism (30, 300, 400) is configured to be selectively operable independently of the energy absorbing mechanism (24, 50).

[0098] [Embodiment 2] A seat belt retractor system according to claim 1, wherein the additional energy absorption mechanism (30, 300, 400), when selected to be inactive, allows the webbing (11) to be unwound without affecting the action of the energy absorption mechanism (24, 50).

[0099] [Embodiment 3] The webbing (11) has a crawling path, a first path (61) through which the webbing (11) extends in a first direction from the retractor; a through anchor (12) provided at the end of the first path (61) and capable of guiding the webbing (11) to fold back in a second direction; 3. A seat belt retractor system according to claim 1 or 2, wherein the additional energy absorption mechanism (30, 300, 400) is provided in the first path (61).

[0100] [Embodiment 4] The additional energy absorption mechanism (30, 300, 400) an actuator (161) that operates upon receiving an actuation signal; an energy absorbing member (150, 310, 411, 412) that is switched from a non-energy absorbing mode to an energy absorbing mode by the actuation of the actuator (161); A seat belt retractor system according to any one of embodiments 1 to 3, comprising:

[0101] [Embodiment 5] A seat belt retractor system according to embodiment 4, wherein the additional energy absorption mechanism (30, 300, 400), when selected to be inactive, does not activate the actuator (161) and maintains the energy absorption member (150, 310, 411, 412) in the non-energy absorbing mode.

[0102] [Embodiment 6] a control device (8) for selecting whether to activate or deactivate the additional energy absorption mechanism (30, 300, 400); A seat belt retractor system according to embodiment 4 or 5, wherein the control device (8) selects to activate the additional energy absorption mechanism (30, 300, 400) and sends the activation signal to the actuator (161) in the event of a collision of a vehicle equipped with the seat belt retractor system.

[0103] [Embodiment 7] A seat belt retractor system according to embodiment 6, wherein the control device (8) selects whether to activate or deactivate the additional energy absorption mechanism (30, 300, 400) depending on the occupant seated in the vehicle seat (1).

[0104] [Embodiment 8] A seat belt retractor system according to embodiment 7, wherein the control device (8) selects whether to activate or deactivate the additional energy absorption mechanism (30, 300, 400) depending on at least one of the weight and body size of the occupant.

[0105] [Embodiment 9] The additional energy absorption mechanism (30, 300, 400) a clamp member (130) that engages with the webbing upon actuation of the actuator; one or more connecting members (140, 320, 330, 420, 430) connecting the clamping member and the energy absorbing member; Furthermore, A seat belt retractor system according to any one of embodiments 4 to 8, wherein when a load exceeding the second predetermined value is applied to the webbing (11), the energy absorption member (150, 310, 411, 412) deforms via the clamp member (130) and the connecting member (140, 320, 330, 420, 430) to absorb energy.

[0106] [Embodiment 10] The energy absorbing member (150) has a U-shaped portion (151), A part (152) of the U-shaped portion (151) is fixed to the connecting member (140), A seat belt retractor system according to embodiment 9, wherein when a load exceeding the second predetermined value is applied to the webbing (11), the other portion (153) of the U-shaped portion (151) of the energy absorption member (150) plastically deforms via the clamp member (130) and the connecting member (140) to absorb energy.

[0107] [Embodiment 11] The energy absorbing member (310, 411, 412) has one or more torsion bars (310, 411, 412), The torsion bars (310, 411, 412) have one end connected to the connecting member (320, 420), A seat belt retractor system according to embodiment 9, wherein when a load exceeding the second predetermined value is applied to the webbing (11), a torsion moment is applied to the one end of the torsion bar (310, 411, 412) via the clamp member (130) and the connecting member (140, 320, 330, 420, 430), thereby absorbing energy.

[0108] [Embodiment 12] The one or more torsion bars (411, 412) a first torsion bar (411); a second torsion bar (412), The one or more connecting members (140, 420, 430) a pinion gear (420) connected to one end of the first torsion bar (411) and one end of the second torsion bar (412); a rack gear (430) that meshes with the pinion gear; a bar member (140) provided between the rack gear and the clamp member, A seat belt retractor system according to embodiment 11, configured such that when a load exceeding the second predetermined value is applied to the webbing (11), the bar member (140) and the rack gear (430) move via the clamp member (130), thereby rotating the pinion gear (420), and transmitting the rotational force of the pinion gear (420) to the first torsion bar (411) and the second torsion bar (412).

[0109] [Embodiment 13] The additional energy absorption mechanism (400) comprises: a first clutch (500) that can switch between a connected state in which the first torsion bar (411), to which the rotational force of the pinion gear (420) is transmitted, can apply a torsion moment without rotating, and a disconnected state in which the first torsion bar (411) rotates and does not apply a torsion moment; a second clutch (600) that can switch between a connected state in which the second torsion bar (412), to which the rotational force of the pinion gear (420) is transmitted, can apply a torsion moment without rotating, and a disconnected state in which the second torsion bar (412) rotates and does not apply a torsion moment; A seat belt retractor system according to embodiment 12, further comprising at least one of the following:

[0110] [Embodiment 14] The additional energy absorption mechanism (30, 300, 400) further includes a receiving member (120) that faces the clamping member (130) with the webbing (11) sandwiched therebetween, The receiving member (120) is a first region (123) that clamps the clamp member (130) engaged with the webbing (11) and the webbing (11); A seat belt retractor system according to any one of embodiments 9 to 14, further comprising: a second region (124) positioned in the unwinding direction of the webbing (11) than the first region (123) for promoting a tendency for the clamp member (130) to release the engagement of the webbing (11). [Explanation of symbols]

[0111] 1...vehicle seat, 2...seat back, 3...seat cushion, 4...headrest, 5...weight sensor, 6...body size sensor, 7...camera, 8...controller, 9...collision sensor, 10...seat belt assembly, 11...webbing, 12...anchorage, 13...tongue, 14...shoulder belt portion, 15...anchorage, 16...lap belt portion, 17...loop portion, 18...buckle, 19...cable, 20...retractor, 21...retractor frame, 22...spindle, 24...energy absorption mechanism, 30...clamp EA (additional energy absorption mechanism), 40...pretensioner a torque limiter, 42...gas tube, 44...gas generator, 50...LLA load limiter (energy absorption mechanism), 51, 52...torsion bar, 53...tread head, 54...connection portion, 55...actuator, 56...locking member, 57...torque tube, 60...crawling path, 61...first path, 62...second path, 110...clamp frame, 111a, 111b...side wall, 112...bottom wall, 113a, 113b...guide hole, 114, 115, 116...mounting hole, 117...webbing insertion hole, 118...plate, 120...lower plate (receiving member), 121, 122...fixing Hole, 123... thick region (first region), 124... thin region (second region), 130... clamping member, 131... pressing surface, 132... guide surface, 133... shaft portion, 135... locking projection, 136... shear pin, 140... bar member (connecting member), 141... fixing surface, 142... guide surface, 143... fixing hole, 144... lower end, 145... upper end, 150... EA plate (energy absorbing member), 151... U-shaped portion, 152... fixing portion, 153... curved portion, 154... bridge portion, 155... side piece, 156... fixing hole, 157... latching piece, 160... actuator unit, 161... LPA, 162... Housing, 163... piston, 170... lever, 171... abutment portion, 172... input portion, 173... rotation shaft portion, 180... guide, 181... webbing insertion slit, 182... insertion shaft portion, 183... tip portion, 190... pin, 200, 210... arrow, 210... arrow, 300... clamp EA (additional energy absorption mechanism), 310... torsion bar (energy absorption member), 320... pinion gear, 330... rack gear, 400... clamp EA (additional energy absorption mechanism), 411, 412... torsion bar, 414, 415... first torque transmission portion, 416... second torque transmission portion,420... pinion gear, 421... gear portion, 422... torque transmission portion, 430... rack gear, 500, 600... clutch, 510, 610... bearing, 511, 611... inner torque transmission portion, 512, 612... outer torque transmission portion, 513, 613... outer ring portion, 520, 620... stopper, 521, 621... torque transmission portion, 522, 622... cam groove, 523, 623... engagement Convex and concave portions, 530, 630...cam plate, 531, 631...ring portion, 532, 632...cam portion, 533, 633...input receiving portion, 700, 800...actuator unit, 761, 861...LPA, 762, 862...housing, 763, 863...piston, 900a, 900b...mounting opening, 910a, 910b...circular portion, 920a, 920b...engagement receiving portion,

Claims

1. A seat belt retractor system including a retractor having an energy absorption mechanism that can absorb energy and unwind the webbing when a load exceeding a predetermined value is applied to the webbing, an additional energy absorption mechanism that enables the webbing to be unwound while absorbing energy when a load exceeding a second predetermined value different from the predetermined value is applied to the webbing on a path along which the webbing is routed that has been extended from the retractor; The seat belt retractor system, wherein the additional energy absorbing mechanism is configured to be selectively operable independently of the energy absorbing mechanism.

2. 2. The seat belt retractor system according to claim 1, wherein when the additional energy absorption mechanism is selected to be inactive, the additional energy absorption mechanism allows the webbing to be unwound without affecting the action of the energy absorption mechanism.

3. The webbing has a crawling path, a first path along which the webbing extends from the retractor in a first direction; a through anchor provided at an end of the first path and capable of guiding the webbing to fold back in a second direction, 2. The seat belt retractor system of claim 1, wherein the additional energy absorption mechanism is provided in the first path.

4. The additional energy absorption mechanism includes: an actuator that operates in response to receiving an actuation signal; an energy absorbing member that is switched from a non-energy absorbing mode to an energy absorbing mode by operation of the actuator; 10. The seat belt retractor system of claim 1, comprising:

5. 5. The seat belt retractor system of claim 4, wherein the additional energy absorbing mechanism, when selected to be deactivated, does not activate the actuator and maintains the energy absorbing member in the non-energy absorbing mode.

6. a control device that selects whether to activate or deactivate the additional energy absorption mechanism; 5. The seat belt retractor system according to claim 4, wherein, when the control device selects to activate the additional energy absorption mechanism, the control device transmits the activation signal to the actuator in the event of a collision of a vehicle equipped with the seat belt retractor system.

7. 7. The seat belt retractor system according to claim 6, wherein the control device selects whether to activate or deactivate the additional energy absorbing mechanism depending on the occupant seated in the vehicle seat.

8. 8. The seat belt retractor system according to claim 7, wherein the control device selects whether to activate or deactivate the additional energy absorbing mechanism depending on at least one of the weight and the physique of the occupant.

9. The additional energy absorption mechanism includes: a clamp member that engages with the webbing by actuation of the actuator; one or more connecting members connecting the clamping member and the energy absorbing member; Furthermore, 9. The seat belt retractor system according to claim 4, wherein when a load exceeding the second predetermined value is applied to the webbing, the energy absorbing member deforms via the clamp member and the connecting member to absorb energy.

10. The energy absorbing member has a U-shaped portion, a portion of the U-shaped portion is fixed to the connecting member, 10. The seat belt retractor system according to claim 9, wherein, when a load exceeding the second predetermined value is applied to the webbing, another portion of the U-shaped portion of the energy absorption member is plastically deformed via the clamp member and the connecting member to absorb energy.

11. the energy absorbing member includes one or more torsion bars; One end of the torsion bar is connected to the connecting member, 10. The seat belt retractor system according to claim 9, wherein when a load exceeding the second predetermined value is applied to the webbing, a torsion moment is applied to the one end of the torsion bar via the clamp member and the connecting member, thereby absorbing energy.

12. The one or more torsion bars a first torsion bar; a second torsion bar; The one or more connecting members are a pinion gear connected to one end of the first torsion bar and one end of the second torsion bar; a rack gear that meshes with the pinion gear; a bar member provided between the rack gear and the clamp member, 12. The seat belt retractor system according to claim 11, wherein when a load exceeding the second predetermined value is applied to the webbing, the bar member and the rack gear move via the clamp member, thereby rotating the pinion gear, and the rotational force of the pinion gear is transmitted to the first torsion bar and the second torsion bar.

13. The additional energy absorption mechanism includes: a first clutch that can switch between a connected state in which the first torsion bar, to which the rotational force of the pinion gear is transmitted, can be caused to apply a torsion moment without rotating, and a disconnected state in which the first torsion bar is rotated and does not cause a torsion moment to be applied; a second clutch that can switch between a connected state in which the second torsion bar, to which the rotational force of the pinion gear is transmitted, can be caused to apply a torsion moment without rotating, and a disconnected state in which the second torsion bar is caused to rotate and not cause a torsion moment to be applied; 13. The seat belt retractor system of claim 12, further comprising at least one of:

14. the additional energy absorption mechanism further includes a receiving member that faces the clamp member with the webbing sandwiched between them, The receiving member is a first region that clamps the webbing and the clamp member engaged with the webbing; 10. The seat belt retractor system according to claim 9, further comprising: a second region located further in the unwinding direction of the webbing than the first region, for promoting a tendency for the clamp member to release the engagement of the webbing with the clamp member.

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