JPH0562360U - Retractor for safety belt - Google Patents

Abstract

(57) [Summary] [Purpose] Having both an emergency lock function and an automatic lock function,
A retractor for a safety belt having a simplified switching mechanism. In a retractor for a safety belt that has both an emergency lock mechanism and an automatic lock mechanism that can be switched, a cam member 31 is rotatably provided on a take-up shaft 2 around which a webbing is wound via a speed reduction mechanism. The cam member 31 is provided with a switching projection 32 and a lock stopper 33 in a predetermined angular range, respectively, which project in the radial direction, and a pawl switching arm 35 which engages and disengages with the switching projection 32 and the lock stopper 33 is attached by a toggle spring 36 so as to be swingable. A control member 41 that is biased and rotates in conjunction with the pawl switching arm 35 is provided so as to be disengageable from the pawl 6 that can be engaged with and disengaged from the tooth portion 3a of the ratchet wheel 3 provided on the winding shaft 2. Configured.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a retractor capable of switching between an emergency lock mechanism and an automatic lock mechanism.

[0002]

[Prior Art]

 The retractor of the automobile safety belt device is provided to prevent forward movement of a person seated in the seat, but this involves only automatically winding the seated person after wearing the belt. The belt has an automatic lock mechanism (ALR) that prevents the belt from being pulled out, and the belt can be taken up and pulled out even after it is installed, and the belt is pulled out by a lock mechanism that is activated by a webbing sensor or a vehicle sensor that operates in an emergency. Some have an emergency locking mechanism (ELR) to prevent.

However, the retractor having the automatic lock mechanism does not have a good feeling of wearing because the webbing cannot be pulled out after the occupant has worn it, and rather, the retractor has an emergency locking mechanism that can be wound and pulled out even after being worn. Things are suitable.

By the way, when an auxiliary seat such as a child seat is attached to the seat device or a luggage is placed on the seat, a retractor having an automatic lock mechanism is more suitable for the auxiliary seat or the luggage after the belt is attached. This is advantageous because it can be fastened to the seat. Therefore, a retractor having both an automatic lock mechanism and an emergency lock mechanism is provided. For example, it is a device described in Japanese Utility Model Laid-Open No. 63-145747.

[0005]

[Problems to be solved by the device]

 However, according to the invention disclosed in Japanese Utility Model Laid-Open No. 63-145747, the ELR / ALR switching mechanism includes a speed reducing unit for reducing the rotational speed of the shaft, a braking lever, two pins for activating the braking lever, and a first Also, since it is composed of a damping member consisting of the second actuator section, a starting lever, and an over center spring (toggle spring), the number of parts is large and the cost increases due to an increase in assembly man-hours.

Further, since the lock structure at the time of ALR operation also serves as the lock operation means of the ELR sensor, it is necessary to synchronize the locking timing with the ratchet wheel of the shaft, which requires high precision in the component dimensions. As a result, there is an inconvenience that manufacturing costs and management costs increase.

Therefore, an object of the present invention is to provide a retractor which solves all of the above drawbacks.

[0008]

[Means for Solving the Problems]

 The retractor for a safety belt according to the present invention is a retractor for a safety belt that has both an emergency lock mechanism and an automatic lock mechanism that can be switched, and a cam member is interlocked with a take-up shaft around which a webbing is wound via a reduction mechanism. The cam member is rotatably provided, and a switching projection and a lock stopper in a predetermined angle range are respectively provided to project in the radial direction, and a pawl switching arm that engages and disengages with the switching projection and the lock stopper is swingably attached by a toggle spring. The control member that is biased and that rotates in conjunction with the pawl switching arm is removably provided with a pawl that engages and disengages with the teeth of the ratchet wheel provided on the winding shaft. And

The deceleration mechanism includes a sun gear connected to the winding shaft and a planetary gear that engages with the sun gear, or an outer peripheral tooth portion that engages with the winding shaft via an eccentric shaft, and the outer peripheral tooth portion. It is also characterized in that it is composed of an inner peripheral tooth portion having one more tooth.

[0010]

[Action]

 In the above structure, when the ELB is switched to the ALR function and the webbing is fully pulled out, the cam member rotates within a predetermined range, and the switching projection comes into contact with the pawl switching arm to rotate it, and the state is toggled. The pawl is held by a spring, and the control member rotates in conjunction with the pawl switching arm. The pawl is forcibly engaged with the teeth of the ratchet wheel to prevent the webbing from being pulled out, and the pawl is kept in the always-engaged state. ..

When the webbing is wound by a predetermined amount, the cam member reversely rotates within a predetermined range, and its lock stopper comes into contact with the pawl switching arm to rotate it reversely, and the state is held by the toggle spring. Then, the control member moves away from the pawl in conjunction with the pawl switching arm, so that the pawl moves away from the teeth of the ratchet wheel, and the original ELR state is restored.

[0012]

【Example】

 An embodiment of this invention will be described below. As shown in FIG. 1, a take-up shaft 2 is rotatably supported by penetrating both side walls 1a and 1b of a U-shaped housing 1 and is attached to a take-up shaft 2 protruding from one side wall 1a. The ratchet wheel 3 is integrally rotatably attached to the other side wall 1b, and the inner end of a winding spring (not shown) is coupled to the other end of the winding shaft 2 protruding from the other side wall 1b. A spring case 4 whose ends are connected to each other is fixed to the side wall 1b. A reel 5 penetrates and is supported by the winding shaft 2, and a webbing having an end connected to the winding shaft 2 is wound around the reel 5.

A pawl 6 engaged with and disengaged from a tooth portion 3 a of the ratchet wheel 3 is rotatably supported by a shaft 7 embedded in the housing 1, and a pin 8 is projectingly provided at an end portion of the pawl 6. It The pawl 6 is urged by a return spring 6a to rotate in a direction in which it is always separated from the ratchet wheel 3. Further, a standman box 10 having a tooth 9 that can be engaged with and disengaged from a ratchet tooth portion 22 of a flywheel 21, which will be described later, is fixed to the side wall 1a. The standman box 10 swings when an impact is applied to the housing 1. A standman 11 (weight) pushes and rotates the tooth 9 to engage the flywheel 21 and prevent the winding shaft 2 from rotating. Is a known vehicle sensor.

A cam wheel 12 is rotatably fitted into a small diameter end portion 2a of the winding shaft 2 having a cut-out circular cross section through a center hole 12a of the winding shaft 2. A cam hole 13 that engages the pin 8 of the ur 6 is formed. When the cam wheel 12 rotates in the webbing pull-out direction, the cam hole 13 pulls the pin 8 to engage the pawl 6 with the ratchet wheel 3, and the ratchet wheel 3 rotates in the webbing take-up direction. When it moves, it separates the pin 8 in the radial direction to separate the pawl 6 from the ratchet wheel 3, while it comprises a triangular hole portion 13b for holding the pawl 6 swingably when the control member 41 abuts. The ratchet wheel 3, the pawl 6, and the bite wheel 12 constitute a locking mechanism that prevents the winding shaft 2 from rotating.

A tooth portion 14 is formed on the inner peripheral surface of the cam wheel 12. Further, a return spring 15 is elastically mounted between the cam wheel 12 and the shaft 7. A hook 19 having a claw projection 16 that is engaged with and disengaged from the tooth portion 14 of the cam wheel 12 partially attaches a spring 18 to a hook retainer 17 fitted and fixed to the irregular cross section of the small diameter end 2a of the winding shaft 2. The cam wheel 12 is loosely fitted into the cam wheel 12 and is housed therein.

The hook retainer 17 and the hook 19 are engaged with each other with a hole 19 a and a recess 19 b into which the protrusions 17 a and 17 b projectingly provided on the hook retainer 17 are loosely fitted, and the hook 19 is attached to the hook 19. One end 20a of the spring 20 is inserted into the hole 19c, and the other end 20b of the spring 20 is locked to the flywheel 21. The center hole 21a of the flywheel 21 is rotatably loosely fitted to the shaft portion 17c of the hook retainer 17, and the ratchet teeth 22 are formed on the outer peripheral surface thereof. The hook retainer 17, the spring 18, the hook 19, the spring 20, and the flywheel 21 constitute a so-called webbing sensor.

A case 23 that covers all the above-mentioned structures and that accommodates the following structures is fixed to the side wall 1 a with screws 24, and the small diameter end of the winding shaft 2 that protrudes from the hole 25 of the case 23. A sun gear 26 is captively fixed to 2a, and a planetary gear 27 that meshes with the sun gear 26 is inserted into a hole 28 formed in the outer bottom portion of the case 23 such that its shaft 29 is rotatably supported. It meshes with 30 to form a speed reduction mechanism for detecting the number of rotations of the winding shaft 2. The planetary gear 27 rotates at a fixed position and does not move around. The inner peripheral tooth portion 30 is formed on the cam member 31.

As shown in FIG. 5, the cam member 31 is integrally formed with a switching projection 32 and a lock stopper 33 on the outer peripheral edge thereof so as to project in the radial direction. A pawl control arm 35 which is engaged with and disengaged from the cam member 31 is fixed to a shaft 34 protruding from a through hole 23a provided in the case 23 and is pivotally supported so as to be pivotable.

As shown in FIGS. 4 and 5, the pawl control arm 35 includes a lever 35a with which the switching projection 32 abuts from one side and a lock stopper 33 from the other side, and one end of a toggle spring 36. It is a V-shaped lever having a locking lever portion 35b. The other end of the toggle spring 36 is supported by a pin 37 protruding from the case 23. Therefore, the pawl control arm 35 can swing to the left and right sides of the center line L connecting the pin 37 and the shaft 34 of the pawl control arm 35.

Furthermore, as shown in FIG. 3, the pawl control arm 35 and the shaft 34 penetrating the through hole 23 a provided in the case 23 are fixed to the shaft 34 so that the control member 41 rotates integrally with the pawl control arm 35. It is movably supported. The control member 41 rotates to abut the pawl 6 and engage the pawl 6 with the tooth portion 3a of the ratchet wheel 3. A case lid 44 is attached to the case 23 with screws 45.

FIG. 5 shows another example of the present invention, in which a so-called taumel mechanism is used in place of the speed reduction mechanism composed of the sun gear and the planetary gears as shown in the figure. An inner peripheral tooth portion 50 is formed on the cam member 31, and a gear 52 having an outer peripheral tooth portion 51 which engages with the inner peripheral tooth portion 50 is provided with a gear 52 having a small diameter end portion via an eccentric shaft 53. 2a is engaged. A projection 54 is formed on the gear 52, and a circular hole 55 for engaging the projection 54 is formed in the case 23.

The setting conditions of the sun gear 26, the planetary gear 27, the inner peripheral tooth portion 30, the inner peripheral tooth portion 50, and the outer peripheral tooth portion 51 of the cam member 31, and the setting position of the switching protrusion 32 of the cam member 31 are changed. As a result, the switching position from ALR to ELR can be set appropriately.

The operation of the above embodiment will be described. First, regarding the emergency lock function, when the webbing is pulled out slowly, the winding shaft 2 rotates and the hook retainer 17 rotates, and the hook retainer 17 and the hook 19 connected via the spring 18 are in the same direction. The hook 19 rotates the flywheel 21 in the same direction via the spring 20 so that a necessary amount of webbing is pulled out. At this time, the take-up shaft 2 rotates and the sun gear 26 rotates, thereby rotating the planetary gear 27 that rotates in a fixed position, and thereby rotating the cam member 31, but pulling out the entire amount of webbing. Until then, the cam member 31 holds the pawl control arm 35 as it is and is in the switching neutral position (shown by the solid line in FIG. 4).

Therefore, when the webbing is mounted and a sudden pulling force is applied to the webbing in that state, the winding shaft 2 rotates in the pulling direction, the hook retainer 17 rotates in the same direction, and the hook retainer 17 and the spring 18 are rotated. The hook 19 connected by means of the flywheel 21 also swings under the influence of the delay in rotation due to the inertial force of the flywheel 21 also connected by the spring 20, and its claw projection 16 engages with the tooth portion 14 of the cam wheel 12. Then, the cam wheel 12 is rotated against the force of the return spring 15 so that the elongated hole 13 engages the pawl 6 with the tooth portion 3a of the ratchet wheel 3 through the pin 8 to move the webbing of the winding shaft 2. The webbing is prevented from being pulled out because the rotation in the pulling direction is blocked. Therefore, the wearer of the webbing is restrained in the seat.

When the vehicle body receives an impact while the vehicle is traveling, the stand man 11 swings to push up the tooth 9 to activate the beakle sensor that engages with the ratchet teeth 22 of the flywheel 21. , The pawl 6 is engaged with the tooth portion 3a of the ratchet wheel 3 to prevent the rotation of the winding shaft 2 in the pull-out direction of the webbing, so that the forward movement of the occupant can be prevented.

Next, regarding the automatic lock function, the entire amount of webbing is pulled out while the emergency lock function is enabled. That is, when the webbing is pulled out slowly, the take-up shaft 2 rotates and the hook retainer 17 rotates, and the hook 19 connected to the hook retainer 17 via the spring 18 tries to rotate in the same direction, and the hook 19 moves. By rotating the flywheel 21 in the same direction via the spring 20 and rotating the sun gear 26, the planetary gear 27 rotating at a fixed position rotates, which causes the cam member 31 to rotate.

When the cam member 31 rotates, the switching projection 32 comes into contact with one side of the lever portion 35a of the pawl control arm 35 and moves the pawl control arm 35, as shown in phantom lines in FIG. The control arm 35 rotates, whereby the toggle spring 36 moves from one side of the center line L to the other side, and the state is maintained. Then, as the pawl control arm 35 rotates and the shaft 34 rotates, the control member 41 rotates in the same direction and presses against the pawl 6 to rotate it, as shown in the phantom diagram in FIG. Then, the pawl 6 is forcibly engaged with the tooth portion 3a of the ratchet wheel 3.

Therefore, the winding shaft 2 integrally connected to the ratchet wheel 3 is always prevented from rotating in the pull-out direction. However, rotation in the winding direction is possible when the pawl 6 gets over the tooth portion 3a. That is, since the pin 8 of the pawl 6 is movable by engaging the triangular hole portion 13b of the cam hole 13, the control member 41 pressed against the pawl 6 is biased by the toggle spring 36, so that the pawl 6 Can be repelled and rockable.

After that, the webbing is always wound around the reel 5 by the force of the spring that urges the winding shaft 2 to wind. Therefore, when an auxiliary seat or the like is attached to the seat by webbing, the auxiliary seat is always fastened and fixed to the seat.

Next, when the auxiliary seat is removed to wind up the extra length of the webbing, the winding shaft 2 rotates in the winding direction, the cam member 31 rotates in the reverse direction, and the lock stopper 33 controls the pawl control. Since the pawl control arm 35 is rotated in the opposite direction to the other side of the lever portion 35a of the arm 35, the toggle spring 36 returns from one side of the center line L to the other side and holds that state. Therefore, the shaft 34 rotates and the control member 41 separates from the pawl 6. Then, the pawl 6 returns to its original state by the return spring 6a and is disengaged from the tooth portion 3a of the ratchet wheel 3. Thus, when the predetermined amount of webbing is wound on the reel 5, the emergency lock function is ready again.

[0031]

[Effect of the device]

 According to the invention described above, the mechanism for switching between ALR and ELR is attached to the housing or the sensor cover, and the braking member is not installed on the cam wheel that rotates when locked. Therefore, the structure is simple and the number of parts is small. Because it is good, assembly costs and parts costs can be reduced. In addition, since the pawl itself that is locked during ALR is directly operated, there are few ALR components, and the parts dimensions do not require high precision. This is a device that solves all the drawbacks of the conventional example.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional plan view of a main part of the assembly shown in FIG.

3 is a sectional view taken along line AA of FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is a vertical sectional side view showing another example of the reduction mechanism.

[Explanation of symbols]

1 ... Housing, 2 ... Winding shaft, 3 ... Ratchet wheel, 5 ... Reel, 6 ... Paul, 8 ... Pin, 10 ... Standman box, 12 ... Cam wheel, 13 ... Cam hole,
14 ... Tooth, 16 ... Claw protrusion, 17 ... Hook retainer,
19 ... Hook, 20 ... Spring, 21 ... Flywheel, 2
2 ... Ratchet tooth portion, 26 ... Sun gear, 27 ... Planetary gear, 31 ... Cam member, 32 ... Switching protrusion, 33 ... Lock stopper, 34 ... Shaft, 35 ... Pawl control arm,
41 ... Control member

Claims (3)

[Scope of utility model registration request] 1. A retractor for a safety belt, which has both an emergency lock mechanism and an automatic lock mechanism that can be switched together, wherein a cam member is rotatably provided on a take-up shaft around which a webbing is wound via a reduction mechanism. The cam member is provided with a switching projection and a lock stopper in a predetermined angle range respectively projecting in the radial direction, and a pawl switching arm engaged with and disengaged from the switching projection and the lock stopper is swingably biased by a toggle spring. A retractor for a safety belt, wherein a control member that rotates in conjunction with a switching arm is provided so as to be disengageable from a pawl that engages and disengages with a tooth portion of a ratchet wheel provided on a winding shaft. 2. The reduction mechanism comprises a sun gear connected to a winding shaft, a planetary gear meshing with the sun gear, and a cam member having an inner peripheral tooth portion meshing with the planetary gear. The retractor for a safety belt according to Item 1. 3. The reduction gear mechanism is composed of an outer peripheral tooth portion engaging with the winding shaft via an eccentric shaft, and an inner peripheral tooth portion having one tooth more than the outer peripheral tooth portion. The retractor for a safety belt according to 1.