JPS6114919Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a safety belt retractor installed in a vehicle or the like.

In conventional retracting devices used for vehicle safety belts, a rewinding spring (hereinafter also referred to as a return spring) is attached to one end of the belt retracting shaft, and the pulled-out belt is pulled out of this spring. It is wound up using spring force (hereinafter referred to as tension). This kind of return spring is designed so that the tension is always applied when the belt is pulled out, so for example, when the driver fastens the safety belt and maintains a normal driving posture, the driver may feel pressure. will be given. For this reason, a safety belt retractor is required that has a mechanism that temporarily relieves the tension of the return spring (hereinafter also referred to as redeuse) once the safety belt is fastened and the driving posture is maintained.

This invention was developed in response to the above-mentioned request, and is a safety belt that has the function of always easing the tension of the return spring in an optimal state according to the driver's driving posture (hereinafter also referred to as tension redeuse). The object of the present invention is to provide a winding device.

The present invention will be specifically explained below using examples.

FIG. 1 is an exploded perspective view showing an embodiment of the safety belt retractor of the present invention, and FIG. 2 is an assembled sectional view of the same. In the figure, reference numeral 1 denotes a frame having a U-shaped cross section, and is fixed to the vehicle floor, seat, etc. by appropriate means. A shaft 2 is rotatably supported between the side plates 1A and 1B of the frame 1 via an insert 1c, and one end of a safety belt 3 is fixed to the shaft 2 so that it can be wound up. As a result, the direction of the arrow X becomes the rotational direction when the belt is pulled out, and the reverse direction Y becomes the rotational direction when the belt is wound. Further, the shaft 2 protrudes outward (leftward in the figure) from one side plate 1A, and has a stepped portion 2A formed at the base end of the protrusion, and one end of a return spring, which will be described later, is locked at the distal end. Locking groove 2B for
is formed. A shaft insertion hole 1D for a reducer, which will be described later, is provided diagonally below the side plate 1A. Further, a retainer 4 having an insertion hole 4A for the shaft 2 in the center thereof is attached to the side plate 1A by appropriate means, and this retainer 4 has a reducer shaft insertion hole 4B and a conductor mounting block described below at the lower part. 4C is provided. In the figure, reference numeral 5 denotes a sensor gear, which consists of a gear 5A having a shaft insertion hole 5E in the center and a stepped protrusion 5B connected to this gear and having an opening on the outside. A plurality of (four in the figure) notches 50A to 50D having different depths are formed at predetermined intervals, and a stepped protrusion 5B is formed.
A plurality (four) of grooves 5D including the notch ends of the notches 50A to 50D are formed at predetermined intervals on the outer peripheral surface of the groove. Further, a spring locking pin 5F is provided below the inside of the stepped protrusion 5B of the sensor gear 5 and protrudes outward along the axis. By the way, each of the cutout portions 50A to 50D is
50 in order based on the shallowest notch 50D
A, 50B, and 50C are arranged, and the second depth notch 50B, the third depth notch 50A, and the deepest notch 50G.
In the figure, 6A to 6D are ring-shaped switch plates, and protrusions 60A to 60D have different lengths, respectively.
It is equipped with Each protruding piece is connected to the inner peripheral edge of the ring-shaped switch plate, and the length relationship is set to be 60D>60B>60A>60C. Such a switch plate is fitted into the groove 5D formed on the outer circumferential surface of the stepped protrusion 5B of the sensor gear 5 by a method such as press fitting, and is fixed in position. At this time, the protrusions of each switch are inserted into the inner surface through cutouts 50A to 50D with different depths provided in the opening of the step protrusion 5B, and the bent portion of the tip of each protrusion is inserted into the inner surface of the sensor gear 5. They are positioned so as to be radially aligned in contact with the wall surface, and each constitute fixed contact pieces A to D. Note that the fixed contact piece C is a first fixed contact,
The fixed contact piece A is a second fixed contact, which is arranged at a position corresponding to the second torque T _{2 of} the return spring 10, and is fixed. The contact piece B is a third fixed contact and is arranged at a position corresponding to the third torque _T3 of the return spring 10, and the fixed contact piece D is a fourth fixed contact and is arranged at a position corresponding to the third torque T3 of the return spring 10. Located at the position corresponding to torque T ₄ . The relationship between the above torques is T ₁ < T ₂ < T ₃ < T ₄ , for example.
T ₁ = 2Kgmm, T ₂ = 4Kgmm, T ₃ = 5Kgmm, T ₄ = 10
Kgmm is set. In the figure, 7 is a ring-shaped common switch plate, which is connected to the inner peripheral edge.
It includes a protrusion 7A extending along the axis, and a movable contact piece 7B provided at the tip of the protrusion 7A and bent along the inner peripheral surface of the common switch plate 7. . In the figure, reference numeral 8 denotes a sensor spring, whose intermediate winding portion is inserted into the shaft 2, and whose one end is locked by a locking pin 5F provided in the stepped protrusion 5B of the sensor gear 5. The end is locked by a locking pin provided on a return spring cover 9, which will be described later. The return spring cover has a sensor spring storage section 9 that is open on one side (on the right side in the drawing) and a return spring storage section 9 that is open on the other side (on the left side in the drawing) sandwiching the intermediate wall section 9B having the shaft insertion hole 9A.
D is formed respectively. A locking pin 9E is formed protruding from inside the sensor spring storage portion 9C to lock one end of the sensor spring 8, and the common switch plate 7 is formed at the open end.
A notch 9F is formed for positioning the movable contact piece 7B provided in the. This notch 9F
The common switch plate 7 is attached and fixed to the outer circumferential surface of the sensor spring accommodating portion via the common switch plate 7. Further, a flange portion 9G is provided at the opening edge of the return spring storage portion 9D.
A spring locking portion 9H is provided at the upper part of the inner wall surface. Inside this return spring storage portion 9D is a spiral return spring 1 whose outer end 10A is locked to the locking portion 9H and whose inner end 10B is inserted into the spring locking groove 2B of the shaft 2.
0 is stored. The return spring cover 9 has a stepped protrusion 5B of the sensor gear 5, which is set to be slightly wider than the outer diameter of the sensor spring storage portion 9C protruding from the right side.
E-ring 1 is inserted loosely into the inside of the E-ring 1.
1A and 11B.

A common switch plate conductor 12E and each switch plate conductor 12D, 12A, 12B, 12C are arranged and fixed in this order on a conductor mounting block 4C formed protruding from the retainer 4, and the tip contact portion of each conductor is The conductors are designed to come into contact with the back surface of each switch plate, and lead wires connected to a control circuit, which will be described in detail later, are connected to the other ends of the conductors. Moreover, the frame side plate 1A
A reduction gear 13 is attached to the inner wall surface of the drive shaft 13A, and a protruding drive shaft 13A protrudes outward through an insertion hole 1D provided in the side plate 1A and an insertion hole 4B provided in the retainer 4. A motor shaft insertion hole 13B is provided on a surface perpendicular to the motor shaft insertion hole 13B, and the drive motor 14 is
is installed. As described above, the driving gear 15 is connected to the tooth portion 5A of the sensor gear 5 through the substantially rectangular mounting hole 15A at the tip of the reducer shaft 13A that protrudes outward from the shaft insertion hole 4B of the retainer 4. They are installed so that they interlock. Incidentally, the motor 14 is driven by a control circuit which will be described later. A cover 16 is attached to the retainer 4 to cover each of the members.

Here, the positional relationship among the sensor gear 5, switch plate, return spring cover 9, sensor spring 8, conductor, etc. will be explained in more detail with reference to FIG. In addition, for convenience of explanation, this figure shows a state where each member is inverted vertically and horizontally, unlike the case of FIG. 1. As shown in the figure, four switch plates 6C,
6B, 6A, and 6D are arranged and fixed in this order, and a sensor spring locking pin 5F is installed on the inner wall surface.
is formed protrudingly, and fixed contact pieces C, A, B, and D connected to each of the switch plates are arranged in this order at appropriate intervals along the wall surface in the vicinity of this pin 5F. Conductors 12C, 12B, 12A, and 12D arranged at predetermined intervals are in contact with the outer peripheral surface of each switch plate in this order. On the other hand, a common switch plate 7 is arranged and fixed on the outer circumferential surface of the return spring cover 9 along the flange portion 9G, and a protrusion 7A connected to the common switch plate 7 extends along the outer circumference of the cover along the axis. A movable contact piece 7B provided at the tip thereof is arranged and fixed along the inner wall surface circumferential surface. This movable contact piece 7
A locking pin 9E for locking one end of the sensor spring 8 is formed protruding from the inner wall surface at a position opposite to position B. The tip of the shaft 2 is inserted through the shaft insertion hole 5E of the sensor gear 5, the sensor spring 8, and the shaft insertion hole 9A of the return spring cover 9, and the return spring cover 9 is inserted inside the sensor gear 5. The two can be connected by fixing the protrusion in a fully fitted state. At this time, the tip of the movable contact piece 7B arranged along the inner wall surface of the return spring cover 9 is attached so as to come into sliding contact with each of the fixed contact pieces A to D arranged on the inner wall surface of the sensor gear 5. Further, the sensor spring 8, which is attached via locking pins 5F and 9E provided on both, detects the strength of the torque in the winding direction of the return spring 10 and is loosely fitted to the sensor gear 5. By changing the twist angle between the movable contact piece 7B and the return spring cover 9, the state of contact between the movable contact piece 7B and the fixed contacts A to D can be changed. Further, in the figure, the direction of arrow X (clockwise) is the direction of rotation when the belt is pulled out, and the opposite direction (counterclockwise, direction of arrow Y) is the direction of rotation when winding the belt.

Next, an example of the configuration of the motor drive motion control circuit will be explained with reference to FIG. A power terminal, between which there is a series circuit of switch SW ₀ and relay coil L ₀ with fixed contact piece B, a direct circuit of switch SW ₁ and relay coil L ₁ with fixed contact piece A, and fixed contact piece C. A series circuit of a switch SW ₂ and a relay coil L ₂ , a series circuit of a switch SW ₃ having a fixed contact piece D and a relay coil L ₃ are connected in parallel, and the switch SW ₀ and a relay coil L ₀ are connected in parallel.
There are three relay contacts with normally closed function between
LS ₁ to LS ₂ are connected, and a normally open relay contact LS ₀ is connected in parallel to this switch SW ₀ . A normally closed relay contact LS ₃ is connected in series to the switch SW ₂ , and a normally open relay contact LS ₂ is connected in parallel. Furthermore, a motor 14 with normally open relay contacts LS ₂ and LS ₂ connected at both ends is connected in series between the power terminal and the normally open relay contact LS between the power terminal side and the terminal side of the motor 14. ₀ and LS ₃ are connected in parallel, and there are also normally open relay contacts on the power terminal side and the motor 14 terminal side.
LS ₃ and LS ₀ are each connected in parallel. Here, the code of each relay coil and the code of each relay contact are correlated, and each relay coil
When L ₀ , L ₁ , L ₂ , and L ₃ are excited, each contact
LS ₀ , LS ₁ , LS ₂ , and LS ₃ are each in operation. If there is such a connection relationship, when connection point B of switch SW ₀ is closed, the relay coil
Since L ₀ is energized and all normally open relay contacts LS ₀ are closed, the motor 14 will rotate in the opposite direction. When contact A of switch SW ₁ is closed, relay coil L ₁ is energized and normally open relay contacts LS ₁ are closed. Since the switch is opened, the motor will stop rotating, and when the contact C of the switch SW ₂ is closed, the relay coil L ₂ will be energized.
Normally closed relay contact LS ₂ opens, normally open relay contact LS ₂
closes, the motor 14 rotates in the forward direction, and when contact D of switch SW ₃ closes, relay coil L ₃ is energized, opening normally closed relay contact LS ₃ and closing normally open relay contact LS ₃ . motor 14
will perform a reverse rotation again. In this sense, among the switches SW ₀ and SW ₃ can be said to be a switch for reverse motor rotation, SW ₁ is a switch for stopping the motor, and SW ₂ is a switch for forward rotation of the motor. Note that when the motor 14 rotates forward, the sensor gear 5 rotates in the belt winding direction, and when the motor 14 rotates in the reverse direction, the sensor gear 5 rotates in the belt pulling direction.

Next, the time chart in Figure 5, Figures 6 to 9
The operation of the device will be described with reference to the operation diagram of the main parts in the figure and the switch operation diagrams of FIGS. 10A to 10F.

When the occupant pulls out the safety belt 3, the shaft 2 rotates in the belt pulling direction (arrow X direction in FIG. 6), and at the same time, the return spring 10 connected to the tip of the shaft 2 is tightened to generate torque. At this time, the movable contact piece 7B is in contact with the contact A of the motor stop switch SW ₁ as shown in FIG. 10A, and the motor 14 is stopped.
Therefore, the sensor gear 5 is also stopped. Next, the return spring cover 9 rotates in the direction of arrow X1 in FIG. 6 due to the spring force of the return spring ₁₀ , which is torqued by the rotation of the shaft 2. The sensor spring 8 connected between the two is twisted in the direction of arrow _X2 in FIG. When the torque applied to the return spring 10 exceeds a set value (for example, the 5 Kgmm line at the set torque shown in FIG. 5), the torsional angle applied to the sensor spring 8 increases, and the return spring cover 9 As shown in FIG. 10B, the connected movable contact piece 7B leaves the contact A of the motor stop switch _SW1 and comes into contact with the contact B of the motor reverse rotation switch _SW0 . Therefore, the motor 14 rotates in the reverse direction due to the operation of the control circuit shown in FIG. 4. As a result, the drive gear 14 attached to the reducer output shaft 13A rotates in the direction of arrow Y in FIG. 8, and drives the sensor gear 5 to rotate in the direction of arrow X. The rotation of the sensor gear 5 in the X direction causes the sensor spring 8 to
The return spring cover 9, which is connected through the return spring cover 9, rotates in the same direction (arrow _X1 direction), and operates to weaken the torque applied to the return spring 10 in the tightening direction.

When the occupant applies torque to the buckle after pulling out the safety belt 3 by a predetermined amount, the pulling out operation of the belt 3 is stopped. When the belt 3 stops pulling out, the torque applied to the return spring 10 becomes weaker as the motor 14 rotates. When the torque of the return spring 10 becomes weaker, the torsion angle decreases due to the spring force of the sensor spring 8, so the return spring cover 9 rotates in the opposite direction (counterclockwise in FIG. 10C), making it movable. The contact piece 7B separates from the contact B of the motor stop switch SW ₁ and comes into contact with the contact A of the motor stop switch SW ₁ , so that the motor 14 stops rotating. The torque of the return spring 10 when the motor is stopped is set, for example, to the 4 Kgmm line in FIG. 5.

If slack (play) occurs in the belt 3 once pulled out by the occupant maintaining a normal driving posture, the belt 3 is wound up by the torque (for example, 4 kgmm) of the return spring 10 when the motor is stopped. . When the amount of winding is large, the amount by which the torque of the return spring 10 is reduced also increases, and when the torque reaches the minimum set value, for example, the line of set torque 2 Kgmm in Fig. 5, the torsion angle by the sensor spring 8 is further reduced. As shown in FIG. 10D, the movable contact piece 7B attached to the return spring cover 9 separates from the stop contact A and comes into contact with the contact C of the motor forward rotation switch _SW2 . As a result, the motor 14 rotates in the forward direction, and the drive gear 15 attached to the reducer output shaft 13A rotates in the direction of arrow X in FIG. 9, so the sensor gear 5 is rotationally driven in the counterclockwise direction (direction of arrow Y). Ru. Since this rotation of the sensor gear 5 is transmitted to the return spring cover 9 via the sensor spring 8, the return spring cover 9 rotates counterclockwise (in the direction of arrow _Y2 in the figure), and the winding force ( torque) is given. Then, as the torque of the return spring 10 increases successively, the torsional angle between the sensor gear 5 and the return spring cover 9 increases, and the torque applied to the sensor spring 8 in the torsional direction increases. As the amount of twisting increases in this way, the movable contact piece 7B separates from the contact C, and sequentially contacts A,
Move B and D in contact with each other. At this time, the fourth
With the configuration of the control circuit shown in the figure, once the motor forward rotation switch _SW2 is turned on, the contacts A and B become ineffective contacts and the forward rotation operation continues. In this way, the torque of the return spring 10 increases, and when it reaches a predetermined value, for example, the set torque line of 10 Kgmm in FIG. 5, the movable contact piece 7B switches the motor reverse rotation switch as shown in FIG. 10E. It will come into contact with contact D of SW ₃ . As a result, the normal rotation of the motor is stopped, and the motor starts rotating in the reverse direction.As mentioned above, when the torque of the return spring 10 is 10 Kgmm, the generated slack is completely wound up.

When motor reverse rotation switch SW ₃ is turned on,
The motor 14 rotates in the opposite direction, and the return spring 10 rotates the sensor gear 5 clockwise (in the direction of the arrow X) as in the case of FIG.
torque becomes weaker. When the torque of the return spring 10 exceeds the 5Kgmm line at the set torque shown in FIG. 5 and approaches the 4Kgmm line, the torsional torque of the sensor spring 8 causes the movable contact piece 7B to contact as shown in FIG. 10F. It passes through point B and moves to contact point A. When the torque reaches 4 Kgmm, contact A is contacted and the rotation of the motor 14 is thereby stopped. As a result, the safety belt 3 is tensioned with an extremely weak torque, allowing the occupant to maintain a comfortable driving condition.

Furthermore, when the occupant changes his or her driving position while wearing the safety belt 3, the belt is freely pulled out in the same way as the above operation, and when it returns to its original position, the same operation as when winding up the slack is performed. The operation is performed in exactly the same manner (see FIG. 5).

Finally, when the tongs are released from the buckle, a slack portion is generated, but the same operation as when winding up the slack portion is performed, and the belt is wound up until it is fully retracted. (See Figure 5).

As detailed above, in the present invention, the safety belt is pulled out and retracted mainly by motor drive, and in particular, the tension of the return spring that is applied when the belt is pulled out is weakened by rotating the spring cover. When installed, the tension is kept constant at its weakest point, so it does not cause any pressure to the occupants. Further, when winding the belt, the torque of the return spring is increased to a maximum value (for example, 10 Kgmm) and then reduced to a steady value (for example, 4 Kgmm), so that the slack of the belt can be reduced to 0 mm. Furthermore, when the belt is rapidly pulled out, the return spring can operate independently, so there is no risk of causing trouble to the motor, speed reducer, etc.

[Brief explanation of the drawing]

FIG. 1 is a schematic exploded perspective view showing an embodiment of the device of the present invention, FIG. 2 is an assembled sectional view of the same essential parts, FIG. 3 is an exploded perspective view of the same essential parts, and FIG. 4 is a motor drive control circuit diagram. FIG. 5 is a time cheat for explaining the operation of the device of the present invention, FIGS. 6 to 9 are diagrams for explaining the operation mode of the main parts, and FIGS. 10A to F are diagrams for explaining the operation mode of the switch. 1... U-shaped frame, 1A... Frame side plate, 2
...Shaft, 3...Safety belt, 4...Retainer, 5
...Sensor gear, 6A-6D...Switch plate, 7...Common switch plate, 7B...Movable contact piece, 8...Sensor spring, 9...Return spring cover, 10...Return spring, 1
2A to 12E...Conductor, 13...Reducer, 14
...Motor, 15...Drive gear.

Claims (1)

[Claims for Utility Model Registration] (1) In a safety belt winding device in which one end is fixed to a belt winding shaft interposed between both side plates of a U-shaped frame, the belt winding device is rotatably attached to the shaft. a return spring having one end fixed to one end of the shaft and the other end fixed to one end of the spring cover; and a sensor gear rotatably supported by the shaft and having a stepped protrusion. and,
A plurality of switch plates arranged at predetermined intervals around the step projection of the sensor gear; The first torque T ₁ and the second torque act on the belt by the expansion and contraction of the return spring based on winding and pulling out.
T ₂ , third torque T ₃ and fourth torque T ₄ (T ₁
<T ₂ <T ₃ <T ₄ <; T ₁ is the minimum torque that acts on the belt when the belt is attached or released, T ₂ is the torque that acts on the belt to give a predetermined tension to the occupant when the belt is attached, and T ₃ is the torque that acts on the belt when the belt is attached and released. The first to fourth fixed contacts are arranged at positions corresponding to the torque that acts on the belt when the belt is pulled out ( _T4 is the maximum torque that acts on the belt when the belt is wound up after the belt is attached), and the side surface of the spring cover. a movable contact that is attached to the spring cover and moves into contact with each of the fixed contacts based on rotation of the spring cover; a plurality of conductors that are arranged in contact with each of the switch plates; and a plurality of conductors that are connected between the sensor gear and the spring cover; A sensor spring that applies a predetermined torsional force between the sensor gear and the spring based on the rotation of the shaft, a motor that rotatably drives the sensor gear, and a movable contact based on signals obtained from each of the conductors. stops the motor when the belt contacts the second fixed contact, and drives the motor in the belt drawing direction when the belt contacts the third fixed contact,
When the first fixed contact is contacted by attaching and releasing the belt, the motor is driven in the belt winding direction, and when the motor is contacted by the fourth fixed contact by winding the belt after attaching the belt. A safety belt retractor comprising: a control circuit that rotates a motor in a belt pulling direction to relieve pressure on an occupant. (2) The first torque T ₁ is 2Kgmm, the second torque T ₂
The safety belt retractor according to claim 1, wherein the third torque T ₃ is set to 4 Kgmm, the third torque T 3 is set to 5 Kgmm, and the fourth torque T ₄ is set to 10 Kgmm.