JPH0562362U - 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 switching tooth 41 that can be engaged with and disengaged from a ratchet wheel 3 provided on a winding shaft 2 around which webbing is wound. Cam wheel 1
The main cam 31 that urges the shaft 2 to swing and supports the take-up shaft 2 through the reduction mechanism on the winding shaft 2 and the sub-cam 33 that engages and disengages the main cam 31 are respectively rotated. The sub cam 33 and the switching tooth 41 are detachably provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a safety belt retractor capable of switching an emergency lock function to an automatic lock function.

[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, the retractor for the safety belt having the automatic lock mechanism is more suitable after the webbing is attached. This is advantageous because the degree of tightening the luggage and luggage to the seat is high. Therefore, a retractor for safety belts, which has both advantages, is being developed. For example, in the inventions disclosed in Japanese Utility Model Laid-Open No. 62-172658 and Japanese Patent Laid-Open No. 63-149245, the emergency lock mechanism can be switched to the automatic lock mechanism.

[0005]

[Problems to be solved by the device]

 However, according to the invention / invention described in the above publication, when the webbing is set in the fully retracted position and the ALR switching portion is set with the webbing switched from the ELR to the ALR, the state where the webbing is once wound is resumed. When the full amount is pulled out, the ALR switching part may not return to the set position due to the fitting backlash (mismatch) of each part, and as a result, it may not switch to ALR.

Therefore, it is necessary to set the webbing at the fully retracted position of the winding shaft and set the ALR switching part after setting the webbing in a slightly wound state in order to consider the looseness in fitting. Therefore, there is an inconvenience in that the assembly further requires labor and costs are increased.

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 locking mechanism and an automatic locking mechanism that can be switched, and can be disengaged with a ratchet wheel provided on a winding shaft around which a webbing is wound. A switching tooth is urged by a cam wheel to pivotally support the switching wheel, and a main cam that regulates the switching tooth via a speed reduction mechanism on a winding shaft and a sub-cam that engages and disengages from the main cam. Each of them is rotatably provided, and the sub-cam and the switching tooth are detachably provided.

Further, the reduction mechanism is composed of a planetary gear that engages with the take-up shaft via a sun gear, and an inner peripheral tooth portion formed on the main cam so that the planetary gear engages, It is characterized by being composed of an outer peripheral tooth portion that engages with the winding shaft via an eccentric shaft, and a cam member having an inner peripheral tooth portion that has one tooth more than the outer peripheral tooth portion. To do.

[0010]

[Action]

 When the webbing is fully pulled out, the main cam rotates together with the sub cam, so that the sub cam releases the restriction of the switching tooth, while the main cam restricts the ratchet with the force exerted by the switching tooth. If you temporarily hold the engagement with the tooth of the wheel and then wind the webbing a little, the main cam will rotate in the opposite direction, the main cam will release the restriction of the switching tooth, and the switching tooth will The urging force pushes the sub cam away and engages the ratchet wheel to switch the ELR to ALR.

Then, when the webbing is wound up by a predetermined amount, both the main cam and the sub cam rotate in opposite directions, the sub cam engages with the switching tooth, and the switching tooth resists the urging force of the ratchet wheel. The ALR is switched to the ELR by being forcedly rotated in the direction away from the teeth.

[0012]

【Example】

 An embodiment of the retractor according to the present 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 a take-up shaft 2 protruding from one side wall 1a is not supported. The ratchet wheel 3 is rotatably mounted as a whole, and the inner end of a winding spring (not shown) is connected 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 A standman box 10 having a tooth 9 which 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. In the standman box 10, the standman 11 (weight) that swings when an impact is applied to the housing 1 pushes the tooth 9 to rotate it, thereby engaging the flywheel 21 and preventing the winding shaft 2 from rotating. It 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. An elongated hole 13 for engaging the pin 8 of the ur 6 is formed. When the cam wheel 12 turns in the webbing pull-out direction, the elongated hole 13 pulls the pin 8 to engage the pawl 6 with the ratchet wheel 3, and when the cam wheel 12 turns in the webbing take-up direction, the pin 8 moves away. The lock pawl 6 is pulled away from the ratchet wheel 3. The ratchet wheel 3, the pawl 6, and the cam wheel 12 constitute a lock 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, and a return spring 15 is mounted between the cam wheel 12 and the shaft 7. Further, a bracket 12b is integrally formed on the flange portion of the cam wheel 12. Shafts 44, 44 of a switching tooth 41 that engages with and disengages from the tooth portion 3a of the ratchet wheel 3 are supported by the bracket 12b, and the switching tooth 41 can be always engaged with the tooth portion 3a by a spring 42. Being urged. As shown in FIGS. 2, 3, and 4, the switching tooth 41 is provided with a braking projection 40 for engaging and disengaging the main cam 31 and the sub cam 33, which will be described later. It can penetrate the elongated hole 23a formed in the outer bottom, contact the sub-cam 33, and engage the lock stopper 32 of the main cam 31.

A hook 19 formed in part with a claw projection 16 that engages and disengages with the tooth portion 14 of the cam wheel 12 is fitted and fixed to the irregular cross section of the small diameter end portion 2 a of the winding shaft 2. It is engaged with a retainer 17 via a spring 18 and is loosely fitted in the cam wheel 12. The hook retainer 17 and the hook 19 are engaged with each other by having a hole 19a into which the projections 17a and 17b projecting from the hook retainer 17 are loosely fitted and a recess 19b, and the hook 19 has a spring 20 in its hole 19c. One end 20a of the spring 20 is inserted, 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 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 a main cam 31 which constitutes a switching cam.

As shown in FIG. 5, the main cam 31 is integrally formed with a lock stopper 32 having a substantially L-shaped cover on the outer peripheral edge thereof so as to project in the radial direction. The lock stopper 32 is a member for adjusting the timing of engaging the switching tooth 41 with the tooth portion 3a. That is, the webbing is slightly wound so that the ALR does not function immediately after the entire amount of the webbing is pulled out but the winding shaft 2 rotates a little in the winding direction to function first. It is provided for this purpose.

The main cam 31 is loosely fitted in the inner circumference circle of the sub cam 33, and the sub cam 33 is rotatably interposed with respect to the main cam 31. The sub-cam 33 is formed in a radial direction with a predetermined width to form a cam portion 34 in a predetermined angular range, a slope 35 is formed at one end of the cam portion 34, and a stopper 36 is formed at the other end thereof. A stopper 37 with which the stopper 32 abuts is formed. In addition, projections 39 with which the stoppers 36 abut are formed on the outer bottom of the case 23, respectively. A case lid 44 is attached to the case 23 with screws 45.

The setting conditions of the sun gear 26, the planetary gear 27, the inner peripheral tooth portion 30 and the inner peripheral tooth portion 50 of the cam member 31, the outer peripheral tooth portion 51, 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.

FIG. 5 shows the operating range of the main cam 31 and the sub-cam 33. In the figure, a is a range in which ALR functions, b is a range in which ALR does not function and the webbing is fully wound, that is, ELR. Represents the range in which

FIG. 6 to FIG. 8 show another example of the present invention, in which a so-called Taumel mechanism is used as a reduction mechanism as shown. That is, the cylindrical portion 23b is formed in the case 23 with the hole 25 as the center, the inner peripheral tooth portion 51 is formed on the inner peripheral surface of the cylindrical portion 23b, and the outer peripheral tooth portion engaging with the inner peripheral tooth portion 51 is formed. A gear 53 forming 52 is engaged with the small diameter end portion 2a of the winding shaft 2 via an eccentric shaft 54. A protrusion 55 is formed on the gear 53, and an oval hole 56 that engages with the protrusion 55 is formed on the main cam 31.

The operation of the above embodiment will be described. First, the emergency lock function will be described. When the webbing is completely wound up, as shown in FIG. 9A, the lock stopper 32 of the main cam 31 is the stopper 37 of the sub cam 33. And the cam portion 34 of the sub-cam 33 pushes the braking projection 40 of the switching tooth 41 radially outward against the force of the spring 42, thereby switching the tooth. 41 is prevented from engaging with the tooth portion 3a of the ratchet wheel 3.

Therefore, when the webbing is pulled out slowly in this state, the take-up shaft 2 rotates and the hook retainer 17 rotates, and the hook retainer 17 and the hook 19 connected via the spring 18 move in the same direction. As the hooks 19 attempt to rotate, the springs 19 cause the springs 20 to rotate in the same direction as the flywheel 21, thereby drawing out the required amount of webbing.

At this time, as the take-up shaft 2 rotates and the sun gear 26 rotates, the planetary gear 27 that rotates at a fixed position also rotates, which causes the main cam 31 to rotate. Until it is pulled out, the braking protrusion 40 of the switching tooth 41 is in sliding contact with the cam portion 34 of the sub cam 33, and thus is in the switching neutral position.

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 The hook 19 connected by means of the flywheel 12 swings under the influence of a delay in rotation due to the inertial force of the flywheel 12 also connected by the spring 20, and its claw projection 16 engages with the tooth portion 14 of the cam wheel 21. Then, the cam wheel 21 is rotated against the force of the return spring 15 so that the long hole 13 engages the pawl 6 with the tooth portion 3a of the ratchet wheel 3 through the pin 8 to allow the ratchet wheel 3 to move. Since the rotation in the pull-out direction is blocked, the webbing of the winding shaft 2 is blocked from being pulled out. 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 and the vehicle sensor that engages with the ratchet teeth 22 of the flywheel 3 operates. By engaging the pawl 6 with the base portion 3a of the ratchet wheel 3, it becomes impossible to rotate the winding shaft 2 in the webbing pull-out direction. Therefore, the wearer of the webbing is bound to the seat.

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 spring 20 in the same direction as the flywheel 21 and rotating the sun gear 26, the planetary gear 27 that rotates at a fixed position rotates, which causes the main cam 31 to rotate.

The main cam 31 rotates and its lock stopper 32 contacts the slope 35 of the sub cam 33 while rotating the sub cam 33 in the same direction, as shown in FIG. 9B. As a result, when the braking protrusion 40 of the switching tooth 41 tries to move to the slope 35 via the cam portion 34, the lock stopper 32 is in contact with the slope 35, so that the braking protrusion 40 is attached to the outer edge of the lock stopper 32. The transfer tooth 41 is retained so that the switching tooth 41 is engaged with the tooth portion 3a of the ratchet wheel 3.

In this way, when the webbing is pulled out from the state where the entire amount of webbing is pulled out, that is, when the winding shaft 2 rotates a little, the main cam 31 moves in the reverse direction as shown in FIG. 9C. Since the braking projection 40 is disengaged from the lock stopper 32 by rotating in the direction, the switching tooth 41 is engaged with the tooth portion 3a of the ratchet wheel 3 by the force of the biased spring 42. When the switching tooth 41 contacts the slope 35 and the switching tooth 41 rotates, the sub cam 33 rotates in the direction opposite to the direction of the main cam 31 and contacts the protrusion 39 and stops.

In this state, when the winding shaft 2 is further rotated about half a turn and the amount of the wound web is further pulled out, the cam wheel 12 is rotated as shown in FIG. 9D. By moving the pin 8 that engages with the elongated hole 13 toward the cam wheel 12, the pawl 6 engages with the tooth portion 3a of the ratchet wheel. It should be noted that the lock stopper 32 is provided with a relief portion so that the switching tooth 41 which rotates simultaneously with the rotation of the cam wheel 12 can move.

Thus, the ALR works, and after that, all the webbing is wound up and cannot be pulled out. Therefore, when an auxiliary seat or the like is attached to the seat, the auxiliary seat is tightly fastened to the seat by winding the webbing.

Then, when the auxiliary seat is removed from the seat and a predetermined amount of webbing is completely wound up, the main cam 31 rotates in the opposite direction to the above, the lock stopper 32 separates from the braking protrusion 40, and as shown in FIG. As shown in e), the lock stopper 32 contacts the stopper 37 of the sub cam 33 to rotate the sub cam 33 in the same direction. Therefore, the slope 35 of the sub-cam 33 approaches the braking protrusion 40 of the switching tooth 41 and pushes the braking protrusion 40 outward in the radial direction, so that the switching tooth 41 is pressed as shown in FIG. 9 (f). Since the engagement between the tooth and the tooth portion 3a is released, the ALR does not function. After that, as long as the braking protrusion 40 is in sliding contact with the cam portion 34, the braking protrusion 40 does not engage with the tooth portion 3a, and thus the original emergency lockable state is restored.

In order to assemble the webbing to the take-up shaft, as shown in FIG. 10A, the take-up shaft 2 is rotated until the full amount is pulled out, and the sewn end of the webbing 60 is taken up. The pin 80 is inserted through the slit 70 of FIG. 2 and assembled, and the webbing 60 is wound around the reel 5 by the urging force of the return spring. When the ALR switching is the time when the webbing 60 is completely pulled out, as shown in FIG. 10B, when the webbing 60 is wound up on the reel 5 again and pulled out again, the dimensional error of each component causes play. Since the winding shaft 2 may not return to the state shown in FIG. 10A, it cannot be switched to ALR. Therefore, if the ALR switching is set to a time when the full amount is withdrawn and a little wound, it is possible to reliably switch to the ALR.

[0035]

[Effect of the device]

 According to the present invention described above, the safety belt retractor enables the ELR to function when the occupant is seated and used, and the ALR to function when the luggage or auxiliary seat is mounted on the seat. In addition, when assembling the webbing, the ALR does not work immediately even when the ALR is set to the drawer and the webbing is returned by a small amount to switch to the ALR. Even if there is play due to the difference in dimensional accuracy, ALR switching will not be disabled. Therefore, the operation of the ALR function can be reliably performed. Moreover, since labor is not required for the assembling, the assembling property is improved.

[Brief description of drawings]

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

FIG. 2 is a general cross-sectional front 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 the arrow B in FIG.

FIG. 5 is a partial front view.

FIG. 6 is an exploded perspective view showing another embodiment.

FIG. 7 is a general cross-sectional front view showing a main part of the assembly shown in FIG.

8 is a sectional view taken along line CC of FIG.

9 (a) to 9 (g) are explanatory views of the operation of the main part.

10A and 10B are explanatory views of a webbing assembled state.

[Explanation of symbols]

1 ... Housing, 2 ... Winding shaft, 3 ... Ratchet wheel, 5 ... Reel, 6 ... Lock pawl, 10 ... Stand man box, 12 ... Cam wheel, 13 ... Long hole, 14 ...
Tooth, 16 ... Claw protrusion, 17 ... Hook retainer, 19 ...
Hook, 20 ... Spring, 21 ... Flywheel, 22 ... Ratchet teeth, 26 ... Sun gear, 27 ... Planetary gear, 30
... Inner peripheral tooth portion, 31 ... Main cam, 32 ... Lock stopper, 33 ... Sub cam, 34 ... Cam portion, 35 ... Slope,
36, 37 ... Stoppers, 38, 39 ... Protrusions, 40 ...
Braking protrusion, 41 ... switching tooth, 42 ... spring

Claims (3)

[Scope of utility model registration request] 1. A retractor for a safety belt having both an emergency lock mechanism and an automatic lock mechanism that can be switched, and a ratchet wheel provided on a take-up shaft around which a webbing is wound and a switchable tooth that can be engaged and disengaged. A main cam that urges the wheel to pivotally support it while restricting the switching tooth via a speed reduction mechanism on the winding shaft, and a sub cam that engages and disengages with the main cam are rotatably provided. A retractor for a safety belt, wherein a sub-cam and the switching tooth are detachably provided. 2. The reduction mechanism comprises a planetary gear that engages with the take-up shaft via a sun gear, and an inner peripheral tooth portion formed on a main cam to engage with the planetary gear. The retractor for a safety belt according to Item 1. 3. A deceleration mechanism is composed of an outer peripheral tooth portion engaging with a winding shaft via an eccentric shaft, and a cam member having an inner peripheral tooth portion having one tooth more than the outer peripheral tooth portion. The retractor for a safety belt according to claim 1, wherein the retractor is for a safety belt.