JP2002321595A - Retractor for seatbelts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a retractor for seatbelts which prevents excessive winding of a webbing and feeling of tight pressure and oppression of passengers. SOLUTION: The retractor 1 for seatbelts is constituted by the webbing 3, an axis of winding 7 which winds the webbing 3, and a main case which stores the axis of winding 7 to be able to rotate. At one end of the axis of winding 7 is connected to a spiral spring 8, and two sheets of lock gears 6 in piles are connected to the axis at the other end of the axis. At the lower position of the two sheets of lock gears 6,a first acceleration speed detection censor 6a to lock rotation of a first lock gear 5a to the winding direction X of the webbing, and a second acceleration speed detection censor 6b to lock rotation of a second lock gear 5b to the drawing direction Y of the webbing are created.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction technique of a seat belt retractor.

[0002]

2. Description of the Related Art An emergency lock type retractor (ELR) is known as a seat belt retractor used for securing a vehicle occupant or the like to a seat to ensure safety. This emergency lock type retractor is provided with acceleration detecting means that responds to sudden acceleration / deceleration or collision of the vehicle, detects a vehicle acceleration exceeding a predetermined value, and physically pulls out the webbing stored in the retractor. To lock (stop the drawer). If the drawer of the webbing is locked during a vehicle collision or the like, the occupant or the like is not thrown out of the seat, so that injury or the like due to a secondary collision can be prevented.

However, in such an emergency lock type retractor, for example, when the vehicle travels on an uneven road surface, the acceleration detecting means which detects the acceleration caused by the vibration of the vehicle body pulls out the webbing for a short time. It is known that a lock is frequently made in between. As described above, when only the webbing is pulled out frequently, only the webbing is wound unilaterally by the spiral spring or the like provided in the retractor, and the occupant feels restrained by the excessively wound webbing. And a feeling of oppression. In particular, in a seat belt device such as a bench seat designed so that the occupant can move relatively freely even when the webbing is mounted, the movement of the occupant is relatively smaller than when the user sits on another seat (for example, a separate seat or the like). This is a problem because the occupant is more strongly restrained, oppressed, and the like.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has been developed in such a manner that a vehicle frequently travels on an uneven road surface and is locked in a webbing pull-out direction. Even in such a case, an object of the present invention is to provide a seatbelt retractor in which excessive winding of a webbing is prevented and an occupant of a seat does not feel a feeling of tightening or pressure.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention has the configuration as described in each claim. The retractor for a seat belt according to the first aspect of the present invention includes a winding shaft for storing (winding) the webbing in a rewindable / pullable state, and a lock unit for locking the rotation of the winding shaft. The locking means includes a winding direction locking mechanism for locking the rotation of the winding shaft in the webbing winding direction, and a drawing direction locking mechanism for locking the rotation of the winding shaft in the webbing drawing direction.
Here, the “webbing take-up direction” refers to a rotation direction for taking up the webbing, and the “webbing take-out direction” refers to a rotation direction for taking out the webbing. According to the seatbelt retractor of the present invention, not only can the webbing be drawn out but also the webbing can be locked. This prevents the webbing from being excessively wound up due to the fact that only the webbing drawer is locked.

In the seat belt retractor of the present invention, the winding direction lock mechanism detects a predetermined vehicle acceleration and locks the rotation of the winding shaft in the webbing winding direction. It has. Here, the term “vehicle acceleration” refers to “vehicle acceleration” including at least the acceleration of the vehicle body in the front-rear direction, and more preferably includes the acceleration of the vehicle body in the left-right direction and the vertical direction. "Vehicle acceleration" refers to the magnitude when the acceleration in any direction is captured in absolute amount. In addition, "predetermined vehicle acceleration" refers to the first
The vehicle body acceleration to be detected by the acceleration detection sensor is appropriately set as “predetermined vehicle body acceleration” from vibration of the vehicle body on uneven roads and the like. Further, in the seat belt retractor according to claim 2, the pull-out direction locking mechanism includes a second acceleration detection sensor that detects a vehicle acceleration greater than a “predetermined vehicle acceleration” detected by the first acceleration detection sensor. Have. When the vehicle body vibrates strongly or collides, the draw-out of the webbing is locked by the second acceleration detection sensor, so that the safety of the occupant is ensured. In the seat belt retractor according to the second aspect, the vehicle body acceleration for locking the webbing withdrawal is set to be larger than the vehicle body acceleration for locking the webbing winding. Thereby, for example, when the vehicle is traveling on an uneven road,
When the vibration of the vehicle body is not so large, only the winding of the webbing is locked, and when the vibration of the vehicle body becomes large, the drawer of the webbing is locked. Such an operation prevents excessive winding of the webbing when traveling on an uneven road or the like, and ensures the safety of the occupant when the vehicle body shakes significantly.

In the seat belt retractor according to the third aspect, the winding direction lock mechanism is configured to mesh with the first lock gear provided coaxially with the winding shaft and the first lock gear. And a first lock member that operates. Then, when the first lock member is operated by the first acceleration detection sensor that has detected a predetermined vehicle body acceleration, the rotation of the winding shaft in the webbing winding direction is locked by meshing with the first lock gear. It has become so. Similarly, the pull-out direction lock mechanism
A second lock gear provided coaxially with the winding shaft; and a second lock member that operates so as to mesh with the second lock gear. When the lock member is operated, the rotation of the winding shaft in the pull-out direction is locked.
According to the above configuration, in the seat belt retractor according to the third aspect, the first lock gear and the second lock gear are provided coaxially and commonly, so that the rotation of the winding shaft is locked. The mechanism is extremely simple and compact.

In the seat belt retractor according to the present invention, at least one of the first acceleration detection sensor and the second acceleration detection sensor is a lock member that is an inertial body that swings due to vehicle body acceleration. Is pressed toward the lock gear to operate the lock member. As the “inertia body”, for example, a steel ball housed in a swingable state in a sensor case or the like, or a steel cylindrical shape configured so that the weight at the other end swings around one end as a fulcrum A member or the like is used. With the acceleration detection sensor configured as described above, the vehicle body acceleration can be sensed sensitively, and the pulling-out and winding-up locking operations of the webbing can be accurately performed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view showing an appearance of a seat belt retractor 1 according to the present embodiment. As shown in FIG. 1, a seat belt retractor 1 includes a webbing 3 wound around a waist and an upper body of an occupant, and a substantially cylindrical shape wound around the webbing 3 so that the webbing 3 can be wound up and pulled out. And a main body case 2 formed by bending a metal plate-like member into a substantially U-shape.

An insertion hole 10 is formed in both side surfaces of the main body case 2, and a winding shaft 7 is attached so as to penetrate the insertion hole 10. To one end of the take-up shaft 7, a spiral spring 8 that constantly applies a rotational urging force to the take-up shaft 7 in the take-up direction is connected. The webbing 3 guided by the webbing guide 9 and drawn out of the main body case 2 is automatically taken up by the rotational urging force of the take-up shaft 7, and is again stored in the main body case 2. ing. Further, two lock gears 5 are connected to the other end of the winding shaft 7 in a coaxially stacked state. Hereinafter, of the two lock gears 5, a lock gear for locking the rotation of the winding shaft 7 in the webbing winding direction (the direction indicated by the arrow X in the drawing) will be referred to as a first lock gear.
And a lock gear for locking the take-up shaft 7 from rotating in the webbing withdrawing direction (the direction indicated by the arrow Y in the drawing) is referred to as a second lock gear 5b.

Below the two lock gears 5, two acceleration detecting sensors 6 are provided which lock the rotation of the two lock gears 5 in response to the acceleration of the vehicle body. The two acceleration detection sensors 6 are firmly attached to side surfaces of the main body case 2 by welding or the like, and claws pushed up in response to the acceleration of the vehicle body are provided on the tooth surfaces of the two lock gears 5. By meshing with each other, the rotation of the two lock gears 5 in one direction is locked (the details will be described later). Below,
Among these two acceleration detection sensors 6, an acceleration detection sensor for locking the rotation of the first lock gear 5a is called a first acceleration detection sensor 6a, and is used for locking the rotation of the second lock gear 5b. The acceleration detection sensor is called a second acceleration detection sensor 6b.

A pair of case members 4a, 4a formed by injection molding of a synthetic resin or the like are provided on both side surfaces of the main body case 2.
b is covered from the outside. As a result, the spiral spring 8 arranged outside one of the side surfaces of the main body case 2 is protected from external impact and the like. In addition, when foreign matter or the like is caught in a driving portion for locking the rotation of the winding shaft 7, such as two lock gears 5 and two acceleration detection sensors 6 arranged outside the other side surface portion of the main body case 2. , So that smooth operation is not hindered. Bearing portions 1 are provided on the inner surfaces of the pair of case members 4a and 4b.
1a and 11b are respectively formed in a cylindrical shape, and both ends of a core shaft body 12 provided so as to penetrate the axis of the winding shaft 7 are fitted into the bearing portions 11a and 11b. It has become. Both ends of the core shaft body 12 are
The take-up shaft 7 is held rotatably in the main body case 2 by being rotatably fitted into each of 1a and 11b.

FIG. 2 and FIG. 3 are front views showing a state in which the side surface of the seat belt retractor 1 on which the two lock gears 5 are arranged is viewed from the front. In order to explain the operation of the two lock gears 5 in an easy-to-understand manner, FIG. 2 shows a first lock gear 5a and a first acceleration detection sensor for locking the rotation of the first lock gear 5a. 6A shows a state where only 6a is disposed on the side surface of the main body case 2. FIG. 3 shows a state in which only the second lock gear 5 b and the second acceleration detection sensor 6 b for locking the rotation of the second lock gear 5 b are arranged on the side surface of the main body case 2. ing.

As shown in FIG. 2, the first lock gear 5a
Is provided with an infinite number of teeth 13a on its outer periphery to form a ratchet. That is, the pawl 14a pushed up by the first acceleration detection sensor 6a meshes with the tooth surface of the ratchet provided on the outer periphery of the first lock gear 5a, so that the webbing of the first lock gear 5a is wound. Only rotation in the taking direction (the direction indicated by arrow X in the drawing) is locked. Then, when the first lock gear 5a is slightly rotated in the direction opposite to the webbing winding direction, the claw portion 14b meshed with the tooth surface of the ratchet drops due to the action of gravity or the like, and the first lock gear 5a drops. Is released from the locked state. In the present embodiment, the combination of the first lock gear 5a and the first acceleration detection sensor 6a corresponds to the "winding direction lock mechanism" in the present invention. As shown in FIG. 3, the configurations of the second lock gear 5b and the second acceleration detection sensor 6b are substantially symmetrical to the “winding direction lock mechanism” shown in FIG. The claw portion 14b pushed up by the second acceleration detection sensor 6b meshes with the tooth surface of a ratchet provided on the outer periphery of the second lock gear 5b, so that the webbing withdrawal direction of the second lock gear 5b (see FIG. Only rotation in the direction indicated by the arrow Y in the middle) is locked. The second lock gear 5b is released from the locked state when the second lock gear 5b is slightly rotated in the opposite direction to the webbing withdrawal direction. In the present embodiment, the combination of the second lock gear 5b and the second acceleration detection sensor 6b corresponds to the "pull-out direction lock mechanism" of the present invention. In the present embodiment, as shown in FIGS. 1 to 3, the first lock gear 5a and the second lock gear 5b
Are provided coaxially with respect to the winding shaft 7. As a result, the mechanism for locking the rotation of the winding shaft 7 is extremely simple and compact as a whole.

FIG. 4 is a view showing the internal structure of the first acceleration detecting sensor 6a by breaking the sensor case 16a. As shown in FIG. 4, the first acceleration detection sensor 6a includes a sensor case 16a and an inertial body 15a housed inside the sensor case 16a. The inertia body 15a is a steel columnar member that is housed in an upright state inside the sensor case 16a, and the outer diameter at an arbitrary location in the substantially upper half is larger than the outer diameter in the optional location in the substantially lower half. Is also formed in a large size. Thus, the center of gravity of the entire inertial body 15a is set so as to be deviated toward the upper half. The tip portion 17a on the upper end side of the inertial body 15a is formed in a hemispherical shape. The hemispherical tip portion 17a is covered with a sensor cap 18a formed in a bowl shape with a depressed center. One end of the sensor cap 18a is connected to the sensor case 16a via a hinge 19a so that the claw 14a provided integrally with the other end can move up and down with the swing of the inertia body 17a. It is configured. That is, FIG.
As shown in (A), when the inertia body 15a stands straight without receiving the vehicle body acceleration, the claw portion 14a is not moved up and does not mesh with the first lock gear 5a. OFF state). FIG. 4 (B)
As shown in the figure, when the inertial body 15a receives a vehicle acceleration equal to or more than a predetermined value and tilts by a predetermined angle in an arbitrary direction, a hemispherical surface formed at the tip portion 17a has a pot-like inclination of the sensor cap 18a. By smoothly moving along the surface, the claw portion 14a is pushed up with the hinge portion 19a as a fulcrum, and meshes with the first lock gear 5a (this state is hereinafter referred to as an ON state). . Note that the second acceleration detection sensor 6b has a configuration that is substantially symmetrical to the first acceleration detection sensor 6a described above. However, in the second acceleration detection sensor 6b, the vehicle body acceleration (the vehicle body acceleration that is turned on) when the inertial body swings and the claw portion 14b is pushed up is turned on in the first acceleration detection sensor 6a. It is set to be larger than the vehicle body acceleration. That is, the second
The inertial body in the acceleration detection sensor 6b is set to be “harder to swing (harder to tilt)” than the inertial body 15a in the first acceleration detection sensor 6a. Such a setting can be realized by, for example, increasing the weight of the inertial body in the second acceleration detection sensor 6b, setting the center of gravity lower, or increasing the weight of the sensor cap placed on the tip end. it can. In the first and second acceleration detection sensors 6a and 6b described above, the claws 14a and 14b that move up and down with the swing of the inertial body correspond to the "lock member" in the present invention.

How the seat belt retractor 1 described above operates to prevent the webbing 3 from being excessively wound up will be described in detail below.

When the vehicle is driven, for example, on an uneven road, the vehicle body swings irregularly in all directions. In addition, the “sway” of the vehicle body may be “sway” with relatively small momentum or “sway” with large momentum.
When the seatbelt retractor 1 is attached to the seat of the vehicle, the first acceleration detection sensor 6a and the second acceleration detection sensor 6b respond to the vibration strength of the vehicle body, that is, the acceleration of the vehicle body. One or both of them are turned on. In the seatbelt retractor 1 of the present embodiment, by appropriately setting the vehicle body acceleration for turning on the two vehicle body acceleration detection sensors 6, the winding operation of the webbing 3 or the locking operation of pulling out the webbing 3 is appropriately performed. It is done at the timing.

In the seat belt retractor 1 according to the present embodiment, when the vehicle body sway is small (weak),
That is, when the vehicle acceleration is small, only the first acceleration detection sensor 6a is set to the ON state. Such a setting requires the vehicle body acceleration to be such that only the winding of the webbing 3 needs to be locked, in other words, it is necessary to prevent the webbing 3 from being tightly tightened due to the strength of the vehicle body swinging on the uneven road. However, this is performed by ascertaining the vehicle acceleration that does not require the locking of the webbing 3 even when the occupant is not shaken enough to be thrown out. Such a value of the vehicle body acceleration which only needs to lock the winding of the webbing 3 is preferably 0.2 G (= 1.96 m / s ² ) or more.
A value less than 0.45 G (= 4.41 m / s ² ) is set.

In the seat belt retractor 1 according to the present embodiment, the vehicle body swings greatly (strong).
In other words, when the vehicle acceleration is large, the first acceleration sensor 6a and the second acceleration sensor 6b
Are set to be in the ON state. Such setting is performed, for example, by determining the vehicle acceleration at which it is necessary to lock the drawer of the webbing 3 so that the occupant is not thrown out because the vehicle body shakes strongly.
Preferably, the value of the vehicle body acceleration that locks the winding and pulling out of the webbing 3 is 0.45 G
(= 4.41 m / s ² ) or more is set. In addition,
The value of 0.45 G (= 4.41 m / s ² ) is determined from a value defined by a related law or the like as a value of the vehicle body acceleration for urgently locking the webbing withdrawal. The correspondence between the ON / OFF state of the first acceleration detection sensor 6a and the second acceleration detection sensor 6b described above and the fluctuation range of the vehicle body acceleration Gs [G] is summarized in Table 1 below. .

[0020]

[Table 1]

As shown in Table 1, the webbing take-up and pull-out locking operations realized by the two acceleration detection sensors 6 in which the vehicle acceleration values to be turned on are set will be described. FIG. 5 is a graph showing an example of a temporal change of the vehicle body acceleration of a vehicle traveling on an uneven road. As shown in FIG. 5, the value of the vehicle body acceleration Gs of the vehicle traveling on the uneven road is 0.2 G
≦ Gs <0.45G (the range of (II) in FIG. 5). However, the value of the vehicle body acceleration Gs is in the range of 0.45G ≦ Gs ((III) in FIG. 5).
) Is frequently reached, and 0 ≦
It also drops occasionally in the range of Gs <0.2 (the range of (I) in FIG. 5). While the value of the vehicle body acceleration Gs fluctuates in the range of (II), only the first acceleration detection sensor 6a is in the ON state, and only the rotation of the winding shaft 7 in the webbing winding direction X is performed. Locked. Thereby, the winding of the webbing 3 is locked, so that the webbing 3 is prevented from being excessively wound while traveling on the uneven road. When the value of the vehicle body acceleration Gs reaches the range of (III), the second acceleration detection sensor 6b is turned ON, and the rotation of the winding shaft 7 in the webbing withdrawing direction Y is locked. As a result, the drawer of the webbing 3 is locked, and the occupant can be fixed to the seat to ensure safety. When the value of the vehicle body acceleration Gs falls to the range (I), the first and second acceleration detection sensors 6a and 6b are both turned off. As a result, the webbing 3 is automatically wound up by the spiral spring 8 to a length that fits the occupant's body.

It is also possible to set the values of the vehicle accelerations at which the two acceleration detection sensors 6 should be turned on to the settings shown in Table 2 below, instead of the settings shown in Table 1, to obtain an excessive amount of the webbing 3. Winding can be prevented.

[0023]

[Table 2]

In setting the value of the vehicle body acceleration Gs shown in Table 2, unlike the setting shown in Table 1, the first acceleration detecting sensor 6a is turned off in the range of 0.45 ≦ Gs (the range of (III)). It is set to be in the state of. As a result, in the range of (III) in which the vehicle body is strongly shaken and the occupant should be fixed to the seat, only the locking operation for pulling out the webbing 3 is performed, and the locking operation for winding the webbing 3 is not performed. When the vehicle body is shaking strongly, it is considered that it is not necessary to lock the winding of the webbing 3 in particular. Therefore, the excessive winding of the webbing 3 is effectively prevented even by the locking operation according to the setting in Table 2. You. However, in order to turn the first acceleration detection sensor 6a once turned on in the range (II) into the off state again in the range (III), the acceleration by the inertial body 15a shown in FIG. Since it may be difficult to realize with a detection mechanism, other known acceleration detection sensors (for example, an acceleration detection sensor that obtains an acceleration value by converting a displacement amount of a pendulum into a current value, or a claw portion using a steel ball. It is necessary to use an acceleration detection sensor that moves the robot upward.

The seatbelt retractor 1 according to the present embodiment, when installed on a bench seat or the like, exhibits the effect of preventing webbing from being tightened more effectively.
That is, the bench seat installed in the vehicle is designed so that its shape is flatter than other seats (for example, a separate seat or the like) and the occupant can relatively freely move while sitting. For this reason, if the webbing is excessively tightened when sitting on a bench seat, the occupant will feel more restricted in movement than if the webbing is seated and tightened on another seat. Become. However, if the seatbelt retractor 1 according to the present embodiment is used, excessive tightening of the webbing 3 is effectively prevented, so that the length of the webbing 3 wound around the occupant is limited to the bench seat. It is possible to ensure a generous length similar to that at the time of initial sitting.

The present invention is not limited to the above embodiment. In the embodiment, the example in which the acceleration detection sensor of the type that pushes up the claw portion by the swing of the inertial body is applied, but various types of acceleration detection sensors can be applied to the present invention. For example, a known acceleration detection sensor using a steel ball that swings by acceleration in a bowl-shaped sensor case can be used. Regardless of whether it is cylindrical or ball-shaped, the use of an acceleration detection sensor that pushes up the lock member by the swing of the inertial body allows sensitive detection of changes in vehicle body acceleration and winds up the webbing. In addition, the lock operation of the drawer can be performed at an accurate timing.

In the embodiment, by adjusting the weight, the center of gravity, and the like of the inertial body and the sensor cap, Table 1 and Table 2 are adjusted.
Although the example of realizing the operation of the seatbelt retractor according to the settings described in (1) is shown, the present invention is not limited to such an embodiment. For example, the value of the vehicle body acceleration Gs is extracted as a numerical value converted into an electric signal by a known acceleration sensor, and the value of the extracted Gs is applied to the settings in Tables 1 and 2 to turn on / off the acceleration detection sensor. OF
Determine the F operation. If it is determined that the acceleration detection sensor is ON, the claw portion is moved upward by an actuator (for example, an electromagnetic coil or the like) that operates by an electromagnetic force or the like. If it is determined that the acceleration detection sensor is OFF,
Deactivate the actuator to drop the claw. In order to determine the ON / OFF operation of the acceleration detection sensor in accordance with such a predetermined setting (for example, the setting in Table 1 or Table 2), the value of the vehicle body acceleration taken out from the acceleration detection sensor is determined by using a microcomputer or an IC. What is necessary is just to input to arithmetic means, such as a circuit. Then, the result of the ON / OFF operation determined by the arithmetic means such as a microcomputer may be output to the actuator as an electric signal.

The seatbelt retractor according to the present invention can exert its effect effectively even when it is attached not only to an automobile but also to another vehicle. For example,
Even if the seatbelt retractor according to the present invention is used by being attached to a seat such as an aircraft or a ship, the effect can be effectively exerted.

[0029]

As described above, according to the present invention,
Even when the vehicle travels on an uneven road surface and locks frequently in the webbing pull-out direction, excessive winding of the webbing is prevented, and the occupant of the seat feels tightness and pressure. It is possible to realize a seat belt retractor that does not make the user feel.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an appearance of a seat belt retractor according to an embodiment.

FIG. 2 is a front view of a side of the seat belt retractor on which two lock gears are arranged;
It is the front view showing the state where only the 1st lock gear and the 1st acceleration detection sensor were arranged.

FIG. 3 is a front view of a side of the seat belt retractor on which two lock gears are arranged,
It is the front view showing the state where only the 2nd lock gear and the 2nd acceleration detection sensor were arranged.

FIG. 4 is a diagram showing an internal structure of a first acceleration detection sensor.

FIG. 5 is a graph showing an example of a temporal change of the vehicle body acceleration of a vehicle traveling on an uneven road.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Seat belt retractor 2 ... Body case 3 ... Webbing 4a, 4b ... Case member 5a ... 1st lock gear 5b ... 2nd lock gear 6a ... 1st acceleration detection sensor 6b ... 2nd acceleration detection sensor 7 ... Winding shaft 8 ... Spiral spring 9 ... Webbing guide 11a, 11b ... Bearing part 13a, 13b ... Teeth 14a, 14b ... Claw part 15a ... Inertial body 16a ... Sensor case 17a ... Tip part

Claims (4)

[Claims] 1. A seat belt retractor comprising: a winding shaft on which a webbing is wound; and locking means for locking rotation of the winding shaft, wherein the locking means comprises a webbing winding of the winding shaft. A retractor for a seat belt, comprising: a take-up direction lock mechanism that locks rotation in a take-up direction; and a pull-out direction lock mechanism that locks rotation of the take-up shaft in a webbing pull-out direction. 2. The retractor for a seat belt according to claim 1, wherein the winding direction lock mechanism detects a predetermined vehicle body acceleration and locks the rotation of the winding shaft in the webbing winding direction.
A pull-out direction locking mechanism that detects a vehicle acceleration greater than the vehicle acceleration detected by the first acceleration detection sensor and locks the rotation of the winding shaft in the webbing pull-out direction. A seat belt retractor comprising the acceleration detection sensor according to any one of the preceding claims. 3. The retractor for a seat belt according to claim 2, wherein the winding direction lock mechanism includes a first lock gear provided coaxially with a winding shaft, and the first lock. A first lock member that operates so as to mesh with a gear; and a winding direction of the winding shaft when the first lock member is operated by a first acceleration detection sensor that detects a predetermined vehicle body acceleration. The pull-out direction locking mechanism is operated so as to mesh with a second lock gear provided coaxially with the winding shaft and the second lock gear. The second lock member is operated by a second acceleration detection sensor that detects a vehicle acceleration greater than the vehicle acceleration detected by the first acceleration detection sensor. Previous A seatbelt retractor which is characterized in that rotation of the pull-out direction of the winding shaft is configured to be locked. 4. The seatbelt retractor according to claim 3, wherein at least one of the first acceleration sensor and the second acceleration sensor is an inertia rocked by vehicle acceleration. A retractor for a seat belt, wherein the body is configured to actuate the lock member by pressing the lock member toward the lock gear.