JPH0732294Y2 - Seat belt retractor - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a seat belt retractor, and more particularly to a spring means for urging the webbing in the winding direction in order to reduce the feeling of pressure when the seat belt is worn. The present invention relates to a retractor for a seat belt that is tensioned to remove slack of the webbing and that winds the webbing with a motor when the webbing is stored.

[Conventional technology]

Conventionally, as a retractor for this type of seat belt, a retractor disclosed in Japanese Utility Model Laid-Open No. 56-27156 is known. This one has a spring means having a tension enough to remove the slack of the webbing, a motor for winding the webbing, and a switch means for turning on the motor for a sufficient time for winding the webbing, When the seat belt is attached, the webbing is lightly biased in the winding direction by the spring means, and when the seat belt is disengaged, the webbing is wound by a motor that is driven only while the buckle release button is pressed.

However, according to the conventional example, there is a problem that the buckle release button must be continuously pressed in order to wind up the webbing.

Therefore, the applicant provided the one described in Japanese Utility Model Laid-Open No. 58-80254 as a solution to such a problem. This product is equipped with spring means with a tension that can remove the slack of the webbing.When the seat belt is attached, the spring means lightly urges the webbing in the winding direction.When the seat belt is disengaged, the buckle disengagement signal is detected. Then, the webbing is wound by the motor for a predetermined time.

However, in the above-mentioned conventional example, the drive of the motor is limited only to the set time, and therefore the motor is stopped when the set time elapses due to the webbing or tongue being caught by the passenger or the interior parts of the vehicle. In some cases, the winding of the webbing remains uncompleted.

Therefore, the Applicant also intends to solve such a problem by connecting to a spindle for supporting a take-up drum of a webbing, and a spring means for constantly exerting a spring force to the spindle to remove a slack of the webbing, Detecting means for detecting disengagement of the tongue from the buckle for mounting the webbing on an occupant, a motor driven by the buckle disengagement signal from the detecting means to rotate the spindle in the webbing winding direction, and acting on the webbing Tension detecting means for detecting tension, and switch means for stopping energization to the motor when the tension of the webbing detected by the tension detecting means exceeds a predetermined value,
There is provided a seat belt retractor having a holding means for holding a state where the energization of the motor by the switch means is stopped.

However, in this device, the switch means reacts sensitively to the tension detecting means, and thus there is a risk of causing a so-called hiccup phenomenon in which the motor repeatedly turns on and off.

Therefore, as a solution to such a problem, the applicant further has a sheet having a holding means for holding only the fluctuation of the tension of the webbing which is equal to or more than a predetermined amount to the switch means so as to hold the stopped state of the energization of the motor. Provided a belt retractor.

[Problems to be solved by the device]

In the conventional example of the applicant, the switch is not turned on unless the webbing is wound by a certain amount of weak spring force after the motor is stopped, and the force of the spring means is lowered particularly near the end of winding. , For example, if the webbing is caught on a sheet or a human body and the winding is stopped, the winding force of the weak spring is balanced with the weight of the tongue and the friction at the sash guide portion, and the webbing may not be further wound. there were.

The present invention has been made in view of the above problems of the conventional technology, and its purpose is to prevent the motor from repeatedly turning on and off when the webbing is retracted and stored, and An object of the present invention is to provide a seatbelt retractor that can be completely wound up and stored without causing a so-called cramping phenomenon when pulling out the webbing.

[Means for Solving the Problems]

In order to achieve the above object, a seat belt retractor according to the present invention comprises a spindle for supporting a take-up drum of a webbing, and a spring which is connected to the spindle and constantly applies a spring force capable of removing looseness of the webbing to the spindle. Means, a detecting means for detecting the disengagement of the tongue for mounting the webbing on the occupant from the buckle, a motor driven in the webbing winding direction by the buckle disengagement signal from the detecting means, and the start of energization of the motor. A delay unit that delays for a certain period of time, a first clutch gear to which the rotational force of the motor is transmitted, a pawl pivotally attached to the first clutch gear, and a first clutch gear that engages with the pawl when the first clutch gear rotates. A centrifugal clutch equipped with a second clutch gear that rotates integrally with one clutch gear, and a drive that rotates integrally with the spindle. Centrifugal, equipped with a planetary gear that is rotatably supported on the shaft, a sun gear that has external teeth that mesh with the planetary gear when the rotation of the second clutch gear is transmitted, and a sensor gear that has internal teeth that mesh with the planetary gear. A planetary gear mechanism that transmits the rotation of the clutch in the webbing winding direction to the spindle, a tension detection unit that urges the sensor gear in the webbing winding direction to detect the tension acting on the webbing, and is rotatably supported by the drive shaft. The webbing tension has exceeded a predetermined value by having a winding amount detecting means for detecting the winding of the entire amount of the webbing by a cam plate that rotates deceleratingly via a detection gear and a switch means for stopping the energization of the motor. When the webbing is completely wound by the rotation of the sensor gear that rotates against the biasing force of the hour tension detecting means, the winding amount detecting means By rotation of the cam plate, it is so allowed to stop energization of the motor by actuating the switch means.

〔Example〕

 Examples will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a seat belt retractor according to the present invention, FIG. 2 is a side sectional view, and FIG. 3 is an exploded perspective view of essential parts.

10 is a retractor body, which is a bottom plate fixed to the vehicle body 11
And a pair of side plates 12a erected from both side edges of the bottom plate 11,
And 12b are formed in a substantially U-shaped cross section. Both side plates 12
A spindle 13 is rotatably supported at the central portions of a and 12b. A winding drum 14 for winding a webbing (not shown) is mounted on the outer circumference of the spindle 13 between the side plates 12a and 12b. Reference numeral 15 is a ratchet wheel that is integrally fitted to the spindle 13.

A known locking mechanism (not shown) covered with a cover 16 is arranged outside the side plate 12b. This lock mechanism detects the acceleration of the vehicle body, the acceleration of the webbing pullout, etc., and engages the stoppers rotatably supported by the side plates 12a, 12b with the ratchet wheels 15, 15 to restrain the webbing pullout. It has become.

On the other hand, on the outer side of the side plate 12a, a substrate 17 extending below the side plate 12a is attached. A motor 18, which is small and rotates only in one direction, is attached to the lower end of the board 17. The rotation shaft 18a of the motor 18 is exposed inside the substrate 17, and a pinion 19 is fitted to the tip of the rotation shaft 18a. The motor 18 is driven by a buckle dissociation signal from a detection unit that detects dissociation of the tongue from the buckle, which will be described later.

On the base plate 17 in the vicinity of the pinion 19, a spindle having a first clutch gear 20 protruding from the base plate 17 so as to mesh with the pinion 19.
It is rotatably supported by 21 and when the motor 18 rotates, its driving force is transmitted to the first clutch gear 20 via the pinion 19. A second clutch gear 22 pivotally supported by the support shaft 21 is rotatably fitted to the first clutch gear 20. The first clutch gear 20 is provided with a support pin 23 protruding toward the second clutch gear 22 side, and a pawl 24 is rotatably pivotally attached to the support pin 23. This Paul 24
Is engaged with a ratchet 25a formed on the inner peripheral surface of the annular wall 25 of the second clutch gear 22, and in the webbing winding direction of the first clutch gear 20 (clockwise direction in FIGS. 2 and 3). A claw portion 24a that transmits the rotation to the second clutch gear 22 is formed. Between the pawl 24 and the pin 26 protruding from the first clutch gear 20, a coil spring 27 for urging the pawl portion 24a of the pawl 24 in a direction to disengage the second clutch gear 22 from the engagement with the ratchet 25a. Is stretched. The annular wall 25 of the second clutch gear 22 is formed so as to surround the outer periphery of the first clutch gear 20, and external teeth 25b are formed on the outer peripheral surface of the annular wall 25. The first clutch gear 20, the second clutch gear 22, and the pawl 24 constitute a centrifugal clutch, and when the first clutch gear 20 rotates clockwise in FIG. Ratchet 25 by rotating outward against the elasticity of 27
By engaging a, the rotation of the first clutch gear 20 is transmitted to the second clutch gear 22.

An insertion hole 28 is formed in the substrate 17 above the first clutch gear 20, and one end of the spindle 13 projects from the insertion hole 28, and the boss 30 of the drive shaft 29 and the spindle 13 are projected in this projection. It is fitted so that it can rotate integrally. A disk is attached to the tip of the boss 30 of this drive shaft 29.
31 are arranged around each other.
Three support pins 32, 32, 32 are provided to project at an angle of 0 degree. Further, the eccentric portion 30 is attached to the tip of the boss 30 in front of the disc 31.
A support shaft 33 is formed on the front side of the eccentric portion 30a and has an axial slit 33a formed at the tip thereof so as to project coaxially with the boss 30.

A planetary gear 34 of a planetary gear mechanism is rotatably supported on each support pin 32 of the drive shaft 29. Each planetary gear 34 is an external tooth of the sun gear 35 of the planetary gear mechanism that is independently rotatably fitted to the boss 30 of the drive shaft 29.
It meshes with 35a. At one end of this sun gear 35 is a disc 36
An outer tooth 36a that meshes with the outer tooth 25b of the second clutch gear 22 is formed on the outer peripheral surface of the disc 36. Then, the rotation of the second clutch gear 22 is changed to the sun gear 35.
Is transmitted to the spindle 13 by rotating the drive shaft 29 in the webbing winding direction (counterclockwise direction in FIGS. 2 and 3) by the planetary gear train of the planet gears 34, 34, 34 and the sensor gear 37. Communicate to.

The sensor gear 37 is interposed between the drive shaft 29 and the sun gear 35. An annular wall 38 surrounding the disc 31 of the drive shaft 29 is provided around the outer periphery of the sensor gear 37, and an inner tooth 38a with which the planetary gears 34 mesh is formed on the inner peripheral surface of the annular wall 38. Has been done. A protrusion 39 is provided on the outer peripheral side of the annular wall 38 of the sensor gear 37.
A coil spring 41 for urging the sensor gear 37 in the webbing winding direction (counterclockwise direction in FIGS. 2 and 3) is stretched between the and the pin 40 protruding from the substrate 17. The coil spring 41 normally has a spring force that keeps the balance of the torque applied to the sensor gear 37, keeps the sensor gear 37 stationary, and rotates the sensor gear 37 when torque is applied when the spindle 13 is stopped. It functions as a tension detecting means for detecting the tension acting on the. The annular wall 38 of the sensor gear 37 has a protruding portion on the drive shaft 29 side.
42 is formed. A mounting portion 43 is provided in a protruding manner on the substrate 17 near the sensor gear 35, and a first micro switch 44 is mounted on the mounting portion 43. Then, when the sensor gear 37 is rotated by the planetary gear train, the protruding portion 42 comes into contact with the actuator 44a of the first micro switch 44 to stop the energization of the motor 18.

A cam plate 45 is fitted on the boss 30 of the drive shaft 29 so as to be rotatable independently of the boss 30. The cam plate 45 is formed with circular holes 46, 46, 46 at an angle of 120 degrees from each other. Further, a protrusion 47 is provided on the outer peripheral portion of the cam plate 45.

48 is a rotation detection gear, and the boss 30 of the drive shaft 29
Is fitted to the eccentric portion 30a. Protrusions 49, 49, 49 are provided on the back surface of the rotation detection gear 48 at an angle of 120 degrees from each other, and the protrusions 49 are fitted in the circular holes 46 of the cam plate 45.

Reference numeral 50 is a cover fitted with the board 17. Inner teeth 51, which are larger than the pitch circle diameter of the rotation detecting gear 48 and more than the number of teeth of the rotation detecting gear 48, are formed on the cover 50 at positions corresponding to the rotation detecting gear 48. The support shaft 33 penetrates the cover 50, and the tip of the support shaft 33 exposed to the outside of the cover 50 is covered with a spring case 52 attached to the cover 50. An inner end of the spring case 52 is held by the slit 33a of the support shaft 33, and an extremely weak winding force to the extent that the slack of the webbing can be removed at all times by the spindle 13
A mainspring spring 53, which is a spring means to be applied to the. Then, the rotation of the drive shaft 29 to which the driving force of the motor 18 is transmitted causes the rotation detection gear 48 to rotate in the inner teeth 51 of the cover 50 in an internal cycloid manner, and transmits this rotation to the cam plate 45. When the webbing take-up amount is reached, the protrusion 47 of the cam plate 45 comes into contact with the actuator 44a of the first micro switch 44, and the power supply to the motor 18 is stopped.

FIG. 4 shows a control circuit for controlling the drive of the motor 18. The second micro switch 54 is arranged in the buckle of the seat belt, and is turned on when the tongue inserted in the webbing is disengaged from the buckle, and detects disengagement of the tongue from the buckle. It functions as a detection means. When the tongue is disengaged from the buckle, the second micro switch 54 is turned on, current flows from the base of the transistor T to the emitter through the resistors R1 and R2, the micro relay L is excited and the relay is closed, and the motor 18 is webbed. Drive in the winding direction. On the other hand, the protrusion 42 of the sensor gear 37 or the protrusion 47 of the cam plate 45 is connected to the first micro switch 44.
When the actuator 44a is contacted, the first micro switch 44 is turned off, and the power supply to the motor 18 is stopped. Five
Reference numeral 5 denotes a capacitor, which functions as a delay unit that delays the start of energization of the motor 18 for a fixed time. In addition, B is a power supply and S is a stabilized power supply by a three-terminal regulator.

[Action]

When the webbing is completely wound around the winding drum 14, the coil spring 41 for biasing the sensor gear 37 in the webbing winding direction (counterclockwise direction in FIGS. 2 and 3) causes The protrusion 42 of the sensor gear 37 is not in contact with the actuator 44a of the first micro switch 44. However, due to the control mechanism of the motor 18 based on the rotation speed detection, the protrusion 47 of the cam plate 45 causes the first micro switch to move.
Since the actuator 44a of 44 is in contact with the actuator 44a, the first micro switch 44 is turned off and the motor 18 is stopped.

In such a state, when the occupant sits on the seat, picks up the webbing, and pulls out the webbing from the winding drum 14 against the weak tension of the mainspring 53, the winding drum 14
At the same time, the spindle 13 rotates, and this rotation is transmitted from the drive shaft 29 to each planet gear 34, and each planet gear 34 revolves clockwise in FIG. Then, either the sun gear 35 or the sensor gear 37 is selectively rotated clockwise in FIG. 3 according to the pulling force of the webbing. When a strong pulling force is applied, the sensor gear 37 rotates, and the protrusion 42 of the sensor gear 37 contacts the actuator 44a of the first micro switch 44. On the other hand, the rotation of the drive shaft 29 causes the rotation detection gear 48 to rotate within the inner teeth 51 of the cover 50, and the rotation of the rotation detection gear 48 causes the cam plate 45 to also rotate. It is separated from the actuator 44a of the first micro switch 44.

After pulling out the webbing, engage the tongue inserted in the webbing with the buckle and attach the seat belt,
Although the sensor gear 37 returns to the stationary state by the spring force of the coil spring 41, the cam plate 45 does not have the webbing completely housed in the take-up drum 14, so the protrusion 47 does not contact the actuator 44a, and the first micro The switch 44 is turned on. However, the second micro switch 54 is turned off and the motor 18 is not driven. In this state, the mainspring 53 exerts only a spring force to the extent that the looseness of the webbing can be removed on the spindle 13, so that a comfortable wearing state can be obtained. Since the centrifugal clutch is provided, the motor 18 does not rotate as the spindle 13 rotates.

Next, when the tongue is disengaged from the buckle, the second micro switch 54 is turned on and the first micro switch 44 is also turned on, so that the motor 18 is driven. The motor 18
With the capacitor 55 provided in the control circuit, even if the second micro switch 54 is turned on, the start of energization of the motor 18 is delayed for a certain period of time, and the webbing can be prevented from being suddenly wound up.

When the motor 18 rotates, its driving force is transmitted to the first clutch gear 20 via the pinion 19. First clutch gear 20
When the wheel rotates, the pawl 24 causes the coil spring 27 due to the centrifugal force.
The rotation of the first clutch gear 20 is transmitted to the second clutch gear 22 by pivoting outward against the elastic force of the above and engaging with the ratchet 25a. The rotation of the second clutch gear 22 is transmitted to the sun gear 35, and the planetary gear train of the planet gears 34, 34, 34 and the sensor gear 37 causes the drive shaft 29 to rotate in the webbing winding direction (counterclockwise in FIGS. 2 and 3). Direction), the spindle 13 rotates, and the webbing is wound around the winding drum 14.

Since the tension of the webbing of the sensor gear 37 is very small until the winding of the webbing is completed, the balance of the torque applied to the sensor gear 37 is maintained by the coil spring 41 and the sensor gear 37 is stationary. When the winding of the webbing is completed, the tension of the webbing sharply increases and a torque exceeding the spring force of the coil spring 41 is applied. Therefore, the planet gears 34, 34, 34
The sensor gear 37 is rotated by the planetary gear train of and. When the sensor gear 37 rotates, the protrusion 42 of the sensor gear 37 contacts the actuator 44a of the first micro switch 44, the first micro switch 44 is turned off, and the power supply to the motor 18 is stopped.

Further, the rotation of the drive shaft 29 causes the rotation detection gear 48 to rotate in the inner teeth 51 of the cover 50 in an inner cycloidal manner to control the number of rotations.
Transmitted to 45. Then, when the winding amount of the webbing is reached, the protrusion 47 of the cam plate 45 causes the first micro switch 44 to move.
Contact the actuator 44a of the first microswitch 4
4 is turned off and the power supply to the motor 18 is stopped. As a result, the webbing is wound up until the webbing is completely stored in the winding drum 14.

When the motor 18 is stopped, the sensor gear 37 is rotated counterclockwise in FIG. 3 by the action of the coil spring 41, the protrusion 42 is separated from the actuator 44a, and the winding of the webbing is completed.

[Effect of device]

The present invention is configured as described above, and it is possible to detect the winding and storing by the winding amount detecting means and perform the winding until the webbing is completely stored in the winding drum.

Further, since the energization of the motor is stopped after the webbing is completely housed in the take-up drum, the motor is not repeatedly turned on and off when the webbing is taken up and housed.

Further, there is no possibility that a so-called hiccup phenomenon occurs when the webbing being mounted is pulled out.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a seat belt retractor according to the present invention, FIG. 2 is a side sectional view, FIG. 3 is an exploded perspective view of essential parts, and FIG. 4 is a control circuit diagram of a motor. 10 ... Retractor body, 13 ... Spindle, 14 ... Winding drum, 18 ... Motor, 20 ... First clutch gear, 22 ...
… Second clutch gear, 24 …… Pawl, 29 …… Drive shaft, 34 …… Planetary gear, 35 …… Sun gear, 37 …… Sensor gear, 41 …… Coil spring, 42 …… Projection part, 44 …… First Micro switch, 45 …… cam plate, 47 …… projection piece,
48 …… Rotation detection gear, 51 …… Internal teeth, 53 …… Spring spring, 54 …… Second micro switch, 55 …… Capacitor.

Claims (1)

[Scope of utility model registration request] 1. A spindle for supporting a take-up drum of a webbing, a spring means connected to the spindle for constantly applying a spring force to the slack of the webbing to the spindle, and a tongue for mounting the webbing on an occupant. Detecting means for detecting disengagement from the buckle, a motor driven in the webbing winding direction by the buckle disengagement signal from the detecting means, a delay means for delaying the start of energization to the motor for a predetermined time, and a rotational force of the motor. A first clutch gear transmitted, a pawl pivotally attached to the first clutch gear, and a second clutch that engages with the pawl when the first clutch gear rotates and rotates integrally with the first clutch gear. Centrifugal clutch with gear, planetary gear rotatably supported on drive shaft that rotates integrally with spindle, second clutch A planetary gear having a sun gear formed with external teeth formed to mesh with the planet gears by transmitting the rotation of the gear and a sensor gear formed with internal teeth formed to mesh with the planet gears, and transmitting the rotation in the webbing winding direction of the centrifugal clutch to the spindle. A gear mechanism and a tension detecting means for urging the sensor gear in the webbing winding direction to detect a tension acting on the webbing,
The webbing has a winding amount detection means for detecting the entire amount of winding of the webbing by a cam plate rotatably supported by the drive shaft and rotating at a reduced speed via a rotation detection gear, and a switch means for stopping the energization of the motor. When the webbing is completely wound up by the rotation of the sensor gear that rotates against the urging force of the tension detecting means when the tension of the winding exceeds a predetermined value, the switch means is rotated by the rotation of the cam plate of the winding amount detecting means. A seat belt retractor characterized by being activated so as to stop energizing the motor.