JP7767376B2 - Seatbelt retractor system - Google Patents

Description

The present invention relates to a seat belt retractor system equipped with a retractor having an energy absorption mechanism that allows the webbing to be unwound while absorbing energy when a load exceeding a predetermined value is applied to the webbing.

Conventionally, retractors installed in vehicle seatbelt devices retract and unwind webbing (seatbelt) by rotating a spindle, and in the event of a vehicle collision, a locking mechanism locks the spindle's rotation to prevent the webbing from unwinding. However, when the impact force of a collision is extremely strong, the webbing tension increases over time after the collision, increasing the load placed on the occupant by the webbing. Therefore, retractors are equipped with an energy absorption mechanism that absorbs energy and unwinds a predetermined amount of 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).

A variety of load limiters (force limiters) have been proposed as energy absorption mechanisms for retractors. For example, the simplest and most representative type (hereinafter sometimes 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 a twist in the torsion bar, which then absorbs energy as it twists due to plastic deformation. There is also a type (hereinafter sometimes referred to as "LLS") in which a stopper is provided on the LL to forcibly stop the LL. Furthermore, there is also a type (hereinafter sometimes referred to as an "LLD" or "two-stage load limiter") in which a bending element is provided in the LL, and the load limiter load (energy absorption load) is increased by the strain (friction) of the bending element in the early stage of the collision, and the strain of the bending element is released in the later stage of the collision, allowing the LL to function as a normal LL (energy absorption by a torsion bar). Another type (hereinafter sometimes referred to as an "LLD" or "two-stage load limiter") is also available in which a torque tube or the like is provided in the LL, and the load limiter load is set to a high value when the occupant is large and to a low value when the occupant is small (hereinafter sometimes referred to as an "LLA" or "variable load limiter"). For example, in an LLA, if the default load limiter load is set to a high value and a small occupant is detected, an MGG (micro gas generator) is activated at the moment of collision to switch to a low load limiter load. There are also types that combine LLD or LLA with LLS (hereinafter referred to as "LLDS" or "LLAS"). Furthermore, LLS, LLD, and LLA can be combined with each other, and there are also types that combine all of these.

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 levels, with a thick torsion bar setting a high load limiter load and a thin torsion bar setting a low load limiter load.

Japanese Patent Application Publication No. 10-250529 International Publication No. 2016/063634

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 continuously adjusts the load limiter load would be complex. In addition, the system that controls the webbing withdrawal speed would also be complex.

The present invention aims to provide a seat belt retractor system with a relatively simple configuration that can accommodate a variety of restraint performance conditions depending on the occupant.

A seat belt retractor according to one aspect of the present invention is a seat belt retractor system equipped with 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 further equipped with 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 first predetermined value is applied to the webbing along the routing path of the webbing extending from the retractor, the additional energy absorption mechanism being configured to be selectively operable independently of the first energy absorption mechanism.

According to this aspect, it is possible to select whether or not to activate the additional energy absorption mechanism, and if activated, the additional energy absorption mechanism can be operated independently of the first energy absorption mechanism. When the additional energy absorption mechanism is not activated, the energy absorption load is that of the first energy absorption mechanism. On the other hand, when the additional energy absorption mechanism is activated, 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 a variety of restraint performance conditions depending on the occupant.

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; 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. 1A and 1B are diagrams showing an LLA load limiter, which is an example of an energy absorption mechanism for a retractor, where (A) shows the load transmission path when the load limiter load is set to a high value, and (B) shows the load transmission path when the load limiter load is set to a low value. 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. FIG. 2 is a perspective view showing the disassembled parts constituting the clamp EA according to the first embodiment, together with a retractor. 10 is a perspective view showing a state in which a clamp frame has been removed from the clamp EA according to the first embodiment, together with a retractor. FIG. FIG. 10 is a cross-sectional view of the clamp EA according to the first embodiment in the initial position, taken at a position passing through the shaft portion of the clamp member. FIG. 10 is a cross-sectional view of the clamp EA according to the first embodiment in the initial position, taken at a position passing through the center (shear pin) of the clamp member. 10A to 10C are schematic diagrams showing an outline of the operation of the clamp EA according to the first embodiment, in which FIG. 10A shows the initial position, FIG. 10B shows the start of operation, and FIG. 10C shows the state during energy absorption. 5A to 5D are cross-sectional views showing details of the operation of the clamp EA according to the first embodiment, in which (a) is a view showing the initial position, (b) is a view showing the start of operation, (c) is a view showing energy absorption, and (d) is a view showing energy absorption (clamp release). FIG. 4 is a diagram showing an outline of combinations of load limiter loads in the retractor system according to the first embodiment. 12A to 12C are diagrams illustrating an outline of a load acting on the webbing in the case of each load limiter load in FIG. 11 . FIG. 13 is a diagram showing an outline of the load acting on the webbing when an LLD is used instead of the LLA load limiter of FIG. 12 . FIG. 10 is a view showing a clamp EA according to a second embodiment. FIG. 10 is a diagram showing an overview of a clamp EA according to a third embodiment. FIG. 11 is a diagram showing an outline of combinations of load limiter loads in the retractor system according to the third embodiment. 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. 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. This is a cross-sectional view taken along line AA in Figure 18. 10A and 10B are cross-sectional views showing the flow of operation of the clamp EA according to the third embodiment, where (a) shows the start of operation, (b) shows energy absorption, and (c) shows after energy absorption (clamp release). 10A and 10B are enlarged perspective views showing the clutch disengagement operation of the clamp EA according to the third embodiment, in which (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 little after (b).

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

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 the correct 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 the correct 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 the correct 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.

EA is an abbreviation 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 load acting on the webbing.

[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.

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

The control device 8 is configured, for example, as 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, ROM and RAM. The ROM stores the control program and control data processed by the CPU, while the RAM is primarily used as a work area for various control processes. The input/output interface is electrically connected to the weight sensor 5, body size sensor 6, and camera 7, as well as a collision sensor 9 that detects vehicle collisions and various actuators (actuator 55 and LPAs 161, 761, and 861, described below). The collision sensor 9 is used to detect vehicle collisions, and can be any of a variety of well-known types, such as an acceleration sensor or pressure sensor.

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, physique sensor 6, or camera 7. Based on the determination result, the control device 8 selects one of multiple 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, i.e., in the event of a vehicle emergency (determines whether 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) to achieve the selected EA load.

[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 for restraining an occupant. The webbing 11 includes a shoulder belt portion 14 extending from an upper guide loop or anchorage 12 to a tongue 13 and a lap belt portion 16 extending 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.

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

[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.

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, the end of the lap belt portion 16 of the webbing 11 is fixed to an anchorage 15 (e.g., the retractor frame 21, the vehicle seat 1, or another part of the vehicle such as the floor pan).

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

The pretensioner 40 is activated, for example, in a vehicle emergency, and pulls the webbing 11 by rotating the spindle 22 in a direction that retracts the webbing 11, thereby removing slack. One example of the pretensioner 40 includes a rod that can move within the 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 upon receiving 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 a vehicle emergency, generating gas that moves the rod within the gas tube 42, causing the tip of the rod to engage with the spindle 22 directly or via another member, and rotating the spindle 22 in the retraction direction. This retracts the webbing 11, removing slack and reducing forward movement or displacement of the occupant.

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), for example, when 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 unwind, giving the occupant a certain degree of freedom of movement, and the webbing 11 may become slack during normal use.

As is well known, a torsion bar constitutes an energy absorption mechanism (load limiter) that maintains a constant level of the restraining force of the webbing 11 applied to the occupant during a frontal collision of the vehicle. For example, in an LL load limiter, the torsion bar is positioned inside the spindle 22, with one end connected to the spindle 22 and the other end connected to a locking member of the locking mechanism. When the locking member locks during a frontal collision of the vehicle, rotation of the spindle 22 is locked. However, if 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, causing the torsion bar to twist. The torsion bar twists due to plastic deformation, absorbing energy and mitigating the impact on the occupant's chest. In other words, the retractor 20 has an energy absorption mechanism 24 that allows the webbing 11 to be unwound while absorbing energy when a load exceeding a predetermined value is applied to the webbing 11.

[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 or the like is 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. Because the LLA load limiter 50 is also a known configuration, the following description will be limited to a brief overview of the configuration and the load transmission path.

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 the tread head 53. The spindle 22 is connected at two points: one end of the thin torsion bar 52 and the connection 54 between the thick torsion bar 51 and the thin torsion bar 52. An actuator 55 selects whether the connection 54 is connected or disconnected, switching the load (torque).

As shown in Figure 3(A), when a high load limiter load (a high predetermined value) is set, the connection portion 54 is also connected to the spindle 22. In this case, the tensile load acting on the webbing 11 is transmitted, in order, to the spindle 22, locking member 56, torque tube 57, thick torsion bar 51, and tread head 53. At this time, the thick torsion bar 51 twists due to the tensile load acting on the webbing 11, absorbing energy. On the other hand, as shown in Figure 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, thin torsion bar 52, thick torsion bar 51, and tread head 53. At this time, only the thin torsion bar 52 twists due to the tensile load acting on the webbing 11, absorbing energy.

The LLA load limiter 50 is set to a high load limiter load by default, for example. 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 can be, for example, a micro-gas generator using explosives. The LLA load limiter 50 is set to switch to a low load limiter load if it is determined that the occupant's weight or physique is small. 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.

[Clamp EA Overview]
2 again, the retractor system of this embodiment includes a clamp EA 30 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, any known energy absorption mechanism, such as an LL, LLS, LLD, LLDS, or LLAS, can be used for the energy absorption mechanism 24.

The clamp EA30 is an additional energy absorption mechanism provided on the routing path 60 of the webbing 11 extending from the retractor 20. Like the energy absorption mechanism 24 of the retractor 20, the clamp EA30 allows the webbing 11 to be unwound 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 high load limiter load and low load limiter load) of the energy absorption mechanism 24. Furthermore, the clamp EA30 is configured to be selectively operable independently of the energy absorption mechanism 24 (details will be described later).

The routing path 60 for the webbing 11 includes a first path 61 extending from the retractor 20 in a first direction (here, upward), an anchorage 12 (through anchor) provided at the end of the first path 61 and capable of guiding 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 positioned 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 away from the retractor 20. Alternatively, the clamp EA30 may be attached to a frame extension portion extending 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 is described below.

[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.

Figure 5 is an exploded perspective view of the parts that make up the clamp EA30. Figure 6 shows the clamp EA30 with the clamp frame 110 removed. Figures 7 and 8 are cross-sectional views of the clamp EA30 in the initial position (when the clamp EA30 is not operating). Of these, Figure 7 is a cross-sectional view taken at a position passing through the shaft 133 of the clamp member 130, and Figure 8 is a cross-sectional view taken at a position passing through the center (shear pin 136) of the clamp member 130. The following describes the configuration of the clamp EA30, mainly with reference to Figure 5. Please refer to Figures 4 and 6-8 as appropriate.

The clamp EA30 comprises 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.

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 attaching various parts. Both ends of the bar member 140 are inserted into the guide holes 113a, 113b. Both ends of the EA plate 150 are fixed to the mounting holes 114, 114. Both ends of the pin 190 are journaled in the mounting holes 115, 115. The mounting holes 116, 116 are used to secure the clamp EA 30 to the retractor frame 21. In other words, the clamp EA 30 is attached to the retractor frame 21 via the clamp frame 110. Plates 118 with webbing insertion holes 117 are attached to the upper ends of the side walls 111a, 111b and the bottom wall 112. The webbing insertion holes 117 are formed in the shape of horizontally elongated slits, through which the webbing 11 is inserted (see Figure 7).

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. Furthermore, on the side opposite the bottom wall 112, the lower plate 120 has two regions 123 and 124 with different plate thicknesses. The thin-walled region 124 is located above the thick-walled region 123, and the surface facing the clamp member 130 is thin-walled.

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 the tip of the wedge. The pressing surface 131 is formed with a number of locking protrusions 135 that can be locked onto the webbing 11 (see Figure 7). The guide surface 132 faces the bar member 140. The guide surface 132 is configured to be able to slide along the guide surface 142 of the bar member 140.

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 Figure 8). The shear pin 136 is designed to break due to the shear force acting when the clamp member 130 begins to slide relative to the bar member 140. In other words, before the clamp member 130 begins to slide, the shear pin 136 holds the clamp member 130 to the bar member 140. When an external force is applied to the shaft portion 133, the shear pin 136 breaks, allowing the clamp member 130 to slide relative to the bar member 140 (see Figure 9).

The bar member 140 has a flat fixed surface 141 and an inclined guide surface 142 on the opposite side of the fixed surface 141. Multiple (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 Figure 7).

The bar member 140 is also movable up and down within the range of the vertical length of the guide holes 113a and 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 and 113b. When the bar member 140 moves upward, it is guided by the guide holes 113a and 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 and 113b, the movement of the bar member 140 is restricted.

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

The actuator unit 160 includes an LPA (Linear Pilot Actuator) 161, which serves as 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 cylindrical housing 162 houses the LPA 161 and the piston 163 below it. The piston 163 moves downward in response to the actuation of the LPA 161. In the initial position, the lower end of the piston 163 faces or abuts against the lever 170 (see Figure 8). When the piston 163 moves downward in response to the actuation of the LPA 161, the piston 163 inputs a force to the lever 170, causing it to rotate.

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 force from the piston 163. The input portion 172 is located 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 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 on the clamp frame 110 so as to be rotatable around the rotating shaft portion 173 (pin 190).

The guide 180 has a webbing insertion slit 181 and an insertion shaft 182. The webbing insertion slit 181 is formed as a horizontally elongated slit through which the webbing 11 is inserted (see Figure 7). The webbing insertion slit 181 guides the webbing 11 immediately after it is unwound from the retractor 20. Three insertion shafts 182 are formed at intervals. 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 tip 183 of the guide 180, which is on the opposite side from the insertion shaft 182, is inserted and fixed into the bottom wall 112 of the clamp frame 110. Therefore, the guide 180 is fixed to the clamp frame 110 via the tip 183 and insertion shaft 182 (pin 190).

[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.

As shown in Figure 9(b), when the LPA 161 is activated, the lever 170 is rotated via the piston 163. The lever 170 then pushes in the clamp member 130, 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 into (pierces) the webbing 11. This secures the locking projection 135 to the webbing 11.

Then, the clamp member 130, which is fixed to the webbing 11 via the locking projection 135, attempts to move in the direction of arrow 200 due to the tension of the webbing 11 (the force in the direction of pulling from the spindle 22), as shown in FIG. 9(c). 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, attempting 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 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.

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 activation 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 protrusion 135 is spaced apart from the webbing 11 as described above, and therefore the locking protrusion 135 does not affect the webbing 11.

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

In the initial position shown in Figure 10(a), the locking projection 135 of the clamp member 130 is separated from the webbing 11. The bar member 140 is positioned at the lower side of the guide hole 113a. The EA plate 150 is in the non-energy absorbing mode.

Figure 10(b) shows the time when the LPA 161 is activated. When the LPA 161 is activated, the piston 163 moves downward, rotating the lever 170. When the lever 170 rotates, the input portion 172 of the lever 170 abuts against the shaft portion 133 of the clamp member 130, moving the clamp member 130. The clamp member 130 is guided upward and toward the webbing 11 by the guide surface 142 of the bar member 140, and the locking projection 135 locks onto (pierces) the webbing 11 and is fixed in place. 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, sandwiching the webbing 11 between them.

Figure 10(c) shows the EA plate 150 in energy-absorbing mode absorbing energy. In the position shown in Figure 10(c), the clamp member 130 is 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 arrow 210 causes the clamp member 130 to move together with the bar member 140 in the direction of 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 arrow 210, causing plastic deformation. The location of plastic deformation shifts on the U-shaped portion 151 as the bar member 140 moves. During this plastic deformation, energy is absorbed and the webbing 11 is unwound. As the EA plate 150 absorbs more energy, the portion of the locking projection 135 that faces the lower plate 120 across the webbing 11 transitions from the thick region 123 to the thin region 124.

Figure 10(d) shows the point when the clamp EA30 reaches its stroke end. Due to the tension of the webbing 11 in the direction of arrow 210, the bar member 140 abuts against the upper end of the guide hole 113a, restricting its movement. Energy absorption by the EA plate 150 ends. All of the locking protrusions 135 have moved to positions facing the thin-walled region 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 protrusions 135 come off the webbing 11. Because the webbing 11 is applied to the tip of the locking protrusion 135, the stress in the locking protrusion 135 changes from shear stress to bending stress and increases. The locking protrusion 135 cannot withstand the bending stress and breaks. This causes the clamp EA30 to release the webbing 11 and unclamp.

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 engaged with the webbing 11, while the thin region 124 (second region) is located in the payout direction of the webbing 11 from the thick region 123, promoting a tendency for the clamp member 130 to release its engagement with the webbing 11. If the thin region 124 were not provided on the lower plate 120, the engaging projection 135 would not come off the webbing 11 and would not break. In this case, although energy absorption by the EA plate 150 would stop at the stroke end, the clamp would not be released.

As can be understood from the explanation of Figure 10, the clamp EA30 operates independently of the energy absorption mechanism 24 of the retractor 20. This means that the operation of either the clamp EA30 or the energy absorption mechanism 24 occurs without affecting the operation of the other.

The driver can select whether to activate or deactivate the clamp EA30. This selection is made by the control device 8 (see FIG. 1) based on the occupant's weight, build, and other factors. If activation of the clamp EA30 is selected, the LPA 161 is activated in the event of a frontal vehicle collision, and the EA plate 150 is placed in energy absorption mode. On the other hand, if deactivation of the clamp EA30 is selected, the LPA 161 is not activated in the event of a frontal vehicle collision, and the EA plate 150 remains in the non-energy absorption mode. In this case, the clamp EA30 does not affect the retraction or unreeling 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 retraction or unreeling force. Naturally, the clamp EA30 allows the webbing 11 to be unreeled without affecting the action (energy absorption) of the energy absorption mechanism 24.

[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 selection of two load limiter load levels, and it is possible to select whether or not to activate the clamp EA 30. Therefore, a total of four load limiter load levels (2 levels x 2 levels) can be selected.

Figure 11(a) shows the combination of a high load limiter load due to a thick torsion bar 51 and the load limiter load when the clamp EA30 is activated. Figure 11(b) shows the combination of a high load limiter load due to a thick torsion bar 51 when the clamp EA30 is not activated. Similarly, Figure 11(c) shows the combination of a low load limiter load due to a thin torsion bar 52 and the load limiter load when the clamp EA30 is activated. Figure 11(d) shows the combination of a low load limiter load due to a thin torsion bar 52 when the clamp EA30 is not activated. It can be seen 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.

Figure 12 is a diagram showing an overview of the load acting on the webbing 11 for each load limiter load shown in Figure 11. In Figure 12, solid lines indicate the case where the clamp EA30 is not activated, and dashed lines indicate the case where the clamp EA30 is activated. For reference, Figure 12 also shows the 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 seen that a forcible stop results in a higher load acting on the webbing 11.

Figure 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 with Figure 12, in Figure 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 with the LLA load limiter 50, it can be seen 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).

As explained above, the retractor system according to this embodiment includes a retractor 20 having an energy absorption mechanism 24, as well as a clamp EA30 (additional energy absorption mechanism) that can be selectively activated independently of the energy absorption mechanism 24. This allows for a relatively simple configuration to select from multiple loads for restraining the occupant, enabling the system to 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., making it possible to restrain the occupant with a load appropriate for the occupant's weight, physique, etc. in the event of a frontal collision of the vehicle.

Next, other embodiments will be described. The following description will focus on the differences from the first embodiment, and components common to the first embodiment will be assigned the same or similar reference numerals and will not be described further.

[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, rather than 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 a 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).

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, bar member 140, and rack gear 330 move upward in the figure, rotating the pinion gear 320. This applies a torsion moment to one end of the torsion bar 310. As the torsion bar 310 twists due to plastic deformation, the energy acting on the webbing 11 is absorbed by the torsion bar 310, and the webbing 11 is unwound.

Here, there may be one torsion bar 310, but there may also be multiple torsion bars. For example, the pinion gear 320 and rack gear 330 can be placed in the center of the clamp frame 110, and torsion bars 310, 310 can be placed on both sides of the pinion gear 320. This improves the load balance compared to when the torsion bar 310 is placed on only one side of the pinion gear 320. In addition, the thickness (diameter) of the torsion bars 310, 310 placed on both sides of the pinion gear 320 can be different from each other, allowing for subtle torque adjustments.

[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.

The clamp EA400 has a pinion gear 420 and a rack gear 430 at the center of the clamp frame 110. One end of a thick torsion bar 411 is connected to the left half of the pinion gear 420, and one end of a thin torsion bar 412 is connected to the right half of the pinion gear 420. The other end of the thick torsion bar 411 is supported by the 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 the 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.

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

Therefore, the load limiter load that can be selected for 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).

[Load limiter load combination summary]
Figure 16 is a diagram showing an overview of combinations of load limiter loads in a retractor system according to the third embodiment. Here, as in the case of Figure 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.

In Figure 16, "ON" and "OFF" mean the following: "OFF" for the LLA load limiter 50 means that the default high load limiter load is used. "ON" for the LLA load limiter 50 means that the low load limiter load set by operating the actuator 55 is used. "OFF" for the clamp EA400 means that the clamp EA400 is not operated, and "ON" for the clamp EA400 means that the clamp EA400 is operated. Furthermore, "ON" for the clutch 500 means that the clutch 500 is operated and separated, i.e., energy absorption by the thick torsion bar 411 is not performed, and the load limiter load by the thin torsion bar 412 is added. "OFF" for clutch 500 means that clutch 500 is not operated and remains connected, i.e., the load limiter load from thick torsion bar 411 is added. "ON" and "OFF" for clutch 600 are the same as for clutch 500.

The clutches 500 and 600 can use various mechanisms. For example, the switching mechanism in the LLA load limiter 50 can be used. This type of switching mechanism is already known, but an overview will be explained with reference to Figure 17 onwards.

[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 A-A 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 shape of the side walls 111a and 111b of the clamp frame 110 has been modified. Specifically, mounting openings 900a and 900b are formed in the side walls 111a and 111b.

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 at the end facing the pinion gear 420, connecting the torsion bars 411, 412 to each other. The torque transmission portions 414, 415, 416 can be configured in the form of serrations or splines.

The pinion gear 420 has a gear portion 421 at the center of its cylindrical outer periphery that meshes with the rack gear 430. Parts of the torsion bars 411 and 412 are inserted into the interior of the pinion gear 420. A torque transmission portion 422 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 Figure 19).

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. Because clutches 500 and 600 have similar configurations, the following description will focus on clutch 500, and for clutch 600, components similar to those in clutch 500 will be assigned the same reference numerals and will not be described again.

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.

The stopper 520 is formed in an overall ring shape. 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 opposing positions 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 opposing positions across the axis of the stopper 520. The cam groove 522 and the engaging protrusion 523 are offset, for example, by 90 degrees from the axis of the stopper 520.

The cam plate 530 has a ring portion 531, a cam portion 532, and an input receiving portion 533. The bearing 510 and stopper 520 are arranged inside the ring portion 531. The outer surface of the ring portion 531 abuts against the inner surface of the side wall 111a. The cam portion 532 protrudes axially from the inner surface of the ring portion 531. A pair of cam portions 532 are formed at opposing positions across the axis of the cam plate 530. The pair of cam portions 532, 532 respectively engage with a pair of cam grooves 522, 522. The input receiving portion 533 protrudes from the outer periphery of the ring portion 531. The input receiving portion 533 is configured to be able to input power from the actuator unit 700. When this power is input, the cam plate 530 receives a rotational force.

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 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 releasably engages with the pair of engagement receiving portions 920a, 920a, respectively.

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

[When clutches 500 and 600 are engaged (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.

Figure 20 is a cross-sectional view showing the operation of clamp EA400, with (a) showing the start of operation, (b) showing energy absorption, and (c) showing the end of energy absorption (when clamp EA400 reaches the end of its stroke).

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.

Here, the other ends of the torsion bars 411, 412 are fixed to the clamp frame 110 via bearings 510, 610 and stoppers 520, 620, so 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 engage with the engaging receiving portions 920a, 920b of the side walls 111a, 111b, so that 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, 412, the torsion bars 411, 412 are twisted by plastic deformation, and the energy acting on the webbing 11 is absorbed by the torsion bars 411, 412.

After that, as shown in Figure 20(c), energy absorption by the clamp EA400 ends. The operation of ending energy absorption by the clamp EA400 and releasing the clamp is the same as in the first embodiment (Figure 10(d)).

[When disengaging 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.

Figure 21 is an enlarged perspective view showing the disengagement operation of the clutch 500, with (a) showing the initial position (clutch 500 engaged), (b) showing the time immediately after a frontal collision of the vehicle, and (c) showing a time a short time after (b).

As shown in Figure 21(b), during a frontal collision of the vehicle, the LPA 761 of the actuator unit 700 is activated. This causes the piston 763 to move out of the housing 762 and come into contact with the input receiving portion 533 of the cam plate 530, causing the cam plate 530 to rotate. As the cam plate 530 rotates, the cam portion 532 of the cam plate 530 interferes with the cam groove 522 of the stopper 520, causing the stopper 520 to move in the thrust direction.

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

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

As explained above, the retractor system according to the third embodiment allows for a greater number of load settings, enabling it to respond to a wider variety of restraint performance conditions.

The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the scope of the present invention. The elements included in the embodiments, as well as their arrangement, materials, conditions, shape, size, etc., are not limited to those exemplified and may be modified as appropriate.

For example, in the modified example of the second embodiment, the pinion gear 320 and 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 rack gear 330 can also be positioned other than at the center of the clamp frame 110.

In addition, in the third embodiment, the clamp EA400 is equipped with both the first clutch 500 and the second clutch 600, but it may also be equipped with only one of them.

Additional Considerations Regarding Various Embodiments
[Embodiment 1]
A seat belt retractor system including a retractor (20) having an energy absorption mechanism (24, 50) that can unwind a webbing (11) while absorbing energy 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).

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

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

[Embodiment 4]
The additional energy absorption mechanism (30, 300, 400)
an actuator (161) that is actuated by 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);
4. The seat belt retractor system of any one of claims 1 to 3, comprising:

[Embodiment 5]
A seat belt retractor system according to claim 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.

[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) sends the activation signal to the actuator (161) when the control device (8) selects to activate the additional energy absorption mechanism (30, 300, 400) in the event of a collision of a vehicle equipped with the seat belt retractor system.

[Embodiment 7]
A seat belt retractor system according to claim 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).

[Embodiment 8]
A seat belt retractor system according to claim 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.

[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,
9. A seat belt retractor system according to any one of claims 4 to 8, wherein when a load exceeding the second predetermined value is applied to the webbing, 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.

[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 claim 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.

[Embodiment 11]
The energy absorbing member (310, 411, 412) has one or more torsion bars (310, 411, 412),
The torsion bar (310, 411, 412) has one end connected to the connecting member (320, 420),
10. A 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 (310, 411, 412) via the clamp member (130) and the connecting member (140, 320, 330, 420, 430), thereby absorbing energy.

[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 claim 11, wherein 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 the rotational force of the pinion gear (420) is transmitted to the first torsion bar (411) and the second torsion bar (412).

[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;
13. A seat belt retractor system according to claim 12, further comprising at least one of:

[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);
15. A seat belt retractor system according to any one of claims 9 to 14, further comprising: a second region (124) located 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).

1...vehicle seat, 2...seat back, 3...seat cushion, 4...headrest, 5...weight sensor, 6...body size sensor, 7...camera, 8...control device, 9...collision sensor, 10...seat belt assembly, 11...webbing, 12...anchorage, 13...tang, 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, 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 2...Fixing hole, 123...Thick region (first region), 124...Thin region (second region), 130...Clamp member, 131...Pressing surface, 132...Guide surface, 133...Shaft portion, 135...Engaging 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...contact portion, 172...input portion, 173...rotating 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, 6 23...engaging protrusion, 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...engaging receiving portion

Claims (14)

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. The seat belt retractor system of claim 1, wherein the additional energy absorption mechanism, when selected to be deactivated, allows the webbing to be unwound without affecting the action of the energy absorption mechanism. 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. 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: The seat belt retractor system of claim 4, wherein when the additional energy absorption mechanism is selected to be deactivated, the actuator is not activated and the energy absorption member is maintained in the non-energy absorbing mode. 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. The seat belt retractor system of claim 6, wherein the control device selects whether to activate or deactivate the additional energy absorption mechanism depending on the occupant seated in the vehicle seat. The seat belt retractor system of claim 7, wherein the control device selects whether to activate or deactivate the additional energy absorption mechanism depending on at least one of the weight and body size of the occupant. 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. 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. 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. 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. 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: the additional energy absorption mechanism further includes a receiving member that faces the clamping member with the webbing sandwiched therebetween,
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.