JPS602218B2 - safety belt retractor - 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 winding devices used for vehicle safety belts, an unwinding spring (
A return spring (hereinafter also referred to as a return spring) is attached, and the pulled out belt is wound up by the spring force of this spring.

This type of turn spring always applies tension to the safety belt when the belt is pulled out, so for example, if the driver maintains a normal driving posture after tightening the safety belt, This will give a feeling of pressure. Therefore, once the safety belt is fastened and the driving position is maintained, a safety belt retractor is required that has a mechanism that temporarily relieves (hereinafter also referred to as "reduce") the tension on the safety belt due to the return spring. .
The present invention has been made in order to meet the above-mentioned demands,
By winding up the safety belt mainly by motor drive, the tension of the safety belt (hereinafter also referred to as tension) is always maintained in an optimal state according to the driving posture of the driver, and in addition, in an emergency, the belt can be instantly tightened. The object of the present invention is to provide a safety belt retractor that can apply a strong tension.

The present invention will be specifically explained below using Examples.

FIG. 1 is a schematic exploded perspective view showing one embodiment of the safety belt retractor of the present invention, and FIG. 2 is an assembled side 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 or seat by appropriate means. A shaft 2 is rotatably supported between the side plates IA and IB of the frame 1 through an insertion hole IC, and one end of a safety belt 3 is fixed to the shaft 2 so that it can be wound. There is. As a result, the arrow x direction 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 from one side plate IA (toward the left in the figure), and has a rectangular fitting protrusion 2A, which will be described later, at the tip of the protrusion for fixing a shaft drive gear, which will be described later. A groove 2B is provided for securing one end of the sub-spring. Furthermore, an insertion hole 4B is provided diagonally below the side plate IA, into which a shaft portion of a drive gear to be described later is inserted. Further, this side plate IA is provided with an insertion hole 4A for the shaft 2, and mounting holes 4C, 4C for mounting a gear holding plate, which will be described later. Reference numeral 5 denotes a gear holding plate, which has a convex cross-section and has mounting holes 5C and 5C at both ends, and holes 5A and 5B for holding reduction gears, which will be described later, in the raised part of the middle part. It is being

This gear holding plate 5 has mounting holes 5C at both ends,
Mounting holes 4C and 4C of the frame side plate IA through 5C
It is attached by appropriate means such as screws. A ball portion 6A of the drive gear 6 is rotatably inserted into the insertion hole 4B of the frame side plate IA, and a fixing hole is provided in the ball portion 6A. A rotary shaft 7A of the motor 7 attached to the motor 7 is inserted and fixed. This motor 7 is connected via a lead wire 78 to a control circuit block 12 whose details will be described later. A reduction gear mechanism 8 is attached to the gear holding plate 5. This reduction gear mechanism 8 has teeth 6 of the drive gear 6.
A first reduction gear 8A that meshes with B, and this first reduction gear 8
A second reduction gear 8B coaxially fixed to A, and this second reduction gear 8B
A third reduction gear 8C that meshes with the reduction gear 8B;
A fourth reduction gear 80 coaxially fixed to the reduction gear 8C, a turning pin 88 rotatably attaching the first and second reduction gears to the attachment hole 5B of the holding plate 5, and the third reduction gear 80.
, a rotating pin 8F with a fourth reduction gear rotatably attached to the mounting hole 5A of the holding plate 5, and both rotating pins 8E, 8F.
and a connecting plate 8G rotatably connected to each other. Reference numeral 10 denotes a sub-spring whose one end is fixed to a groove 28 at the tip of the shaft 2 that projects outward from the insertion hole 4A of the frame side plate IA.
The other end of 0 is a spring cover 11 disposed on the outside thereof.
It is fixed to the inner surface of.

This spring cover 11 has a cup shape, and is fixed to the side surface of the frame side plate IA by appropriate means while covering the supplement spring, and the shaft 2 is inserted through the insertion hole 11A formed in the center thereof. The tip is protruding. Competing protrusion 2 at the protruding tip of this shaft 2
A shaft drive gear 9 is engaged with A through a coupling hole 9A, and this shaft drive gear 9 meshes with the fourth reduction gear 8D of the reduction mechanism 8. Further, a pulser 20 is fixed to the tip of the shaft 2 that projects outward (to the right in the figure) from the frame side plate IB. For example, as shown in FIG.
A conductive foil pattern (for example, copper foil) 208 is attached to the surface of 0A, and this copper foil is attached to the circular ground portion 21 on the inner circumference.
E, an intermediate portion 21 connected to this and extending radially to the outer periphery;
A, an externally extending portion 21 further extending from the intermediate portion via the stepped portion;
It has a region B, and contacts E, A, and B fixed to the frame 1, for example, are arranged at positions corresponding to each region (see FIGS. 2 and 3). Note that a lead wire (not shown) extends from each contact point, and the tip of the lead wire is connected to the control circuit block 12. This pulser 20 and contacts E, A, and B constitute a shaft rotation direction detection section. Incidentally, an inertial sensing device (hereinafter also referred to as a G sensor) 22 that operates in an emergency such as a vehicle collision is attached to the outside of the frame side plate IB. This G sensor 2
2 closes a switch by the displacement of a pendulum, for example, and sends an electric signal to a control circuit. Next, the contents of the control circuit block 12 will be explained with reference to FIG. This control circuit block 12 includes a phase detection circuit 13 that inputs the contact outputs pulser A and pulser B of the balser 20 and detects their phases, and gates the output of the pulser A and the two outputs C and D of the phase detection circuit 13. two AND gates that generate two outputs E, F, respectively.
AND2, take-up side (W) pulse processing circuit 14A, drawer side (D) pulse processing circuit 14B, and D pulse processing circuit 1
Time lag circuit 15 that gives a time lag to the output of 4B
, a first storage circuit 16 that stores the output of the time lag circuit 15, an inverter IN that inverts the output of the D pulse processing circuit 14B, and a tong and buckle (not shown) provided at the tip of the safety belt 3. a transition detection circuit 17 that outputs a pulse every time the output signal of the buckle switch SW, which operates depending on the engagement state of the buckle switch SW changes, and a second storage circuit 18 that stores the output of the transition detection circuit 17
This second memory circuit 18, the first memory circuit 16, W
It is controlled by an OR gate OR, which has three inputs for each output of the pulse processing circuit 14A, an AND gate AND3, which has two inputs for each output of the OR gate OR, and the inverter elbow, and the output of this AND gate AND3. a first driving transistor Tr for driving the motor 7; an ungate AND4 having two inputs: the output signal from the buckle switch SW; and the output M when the G sensor 22 operates; It is constituted by a second driving transistor T that drives the motor 7 under the control of the output of an AND gate AND4, and a current limiting circuit 19 that limits the current flowing through the first driving transistor T. Here, the current limiting circuit 19 is provided because the first driving transistor T is used to make the rotation of the motor 7 relatively slow during normal safety belt winding.
In contrast, in the case of emergency winding, a high tension must be applied to the safety belt, so the second driving transistor Tr is
21, the current 12 flowing therethrough is made larger. As the power supply +V, a battery power supply of DC 12V or 24V is used. Incidentally, each of the memory circuits 16 and 18 are both W.
The output of the side pulse processing circuit 14A changes from the "H" level to the "L" level.
” The level is cleared the moment you step down. The phase detection circuit 13 includes, for example, inverters IN2 and IN3 for inverting the outputs from the contacts A and B for the pulser 20, and a D-type flip-flop FF, as shown in FIG.
It is composed of.

When the above-mentioned pulser 20 and contacts E, A, and B are in the relationship as shown in FIG. 6, each output A, B, A, and B as shown in FIG. 7a during clockwise (CW) rotation. , Q are obtained, and the rotation in the winding direction (W, W) is detected. When rotating in the counterclockwise direction (CCW), an output as shown in FIG. 7b is obtained, and the rotation in the drawing direction (Drawer, 0 ) is now detected. The transition detection circuit 17 is connected to the power supply Vcc and the buckle switch SW, as shown in FIG.
, the first exclusive logic gate EX whose two inputs are the output date of
OR, and the power supply Vcc and the first exclusive logic gate EXOR
, and output J obtained through a time constant circuit (consisting of a resistor Ro and a capacitor Co). Output K and the buckle switch SW
, the third exclusive logic gate EX whose two inputs are the output date of
It is composed of OR3 and buckle switch S.
Every time the signal date of W changes, a pulse-like output L having a predetermined width T as shown in FIG. 9 is generated. This predetermined width T can be arbitrarily adjusted depending on how the time constant circuit is set. Next, the operation of the above-mentioned component device will be explained with reference to an explanatory diagram of control operation torque in FIG. First, when the belt 3 is pulled out, the motor 7 idles and the sub-spring (sub-S
PC) 10 is involved.

At this time, the belt pull-out resistance is the sum of the load when the motor is idling and the torque when winding the sub-spring 10 (for example, 3 to 4 k9 · ribs), so if the tension of the sub-spring 10 is set weak, the belt can be pulled out. This can be done easily (state 1 in Figure 10). At this time, Balcer 2
Since the motor rotates clockwise (CW), the pulsar A output is generated first, and then the pulsar B output is generated in a partially wrapped state (the state shown in Fig. 7 2), as shown in Fig. 4. The phase detection circuit 13 in the control circuit 12 has C=“H”,
Since it generates an output of 0 = “L”, the AND gate AND2
The D-side pulse processing circuit 148 is activated by the pulse output F, and generates an "H" level output. This "H" level output is inverted to "L" level by the inverter IN, so the AND gate AN that controls the transistor Tr.
The output G of D3 goes to the "L" level and turns off this transistor Tr, so that the motor 7 is not driven to rotate and maintains its idling state. Next, when the occupant pulls out the safety belt 3 to a desired length and engages the tongs in the buckle (not shown), the buckle switch SW is turned on, and at this moment the transition detection circuit 17
A pulse-like output L as shown in the figure is generated and is stored in the second storage circuit I8, so the storage output ("H" level) is input to the OR gate OR, and the OR gate OR,
The output becomes "H" level. If the occupant releases the safety belt 3 once the tongue is engaged with the buckle, the safety belt becomes slack. At this stage, the belt winding shaft 2 begins to rotate in the belt winding direction, so the pulser 20 also rotates in the belt winding direction, generating pulse outputs as shown in A and B in FIG. 7b. . As a result, the output of the phase detection circuit 13 is C
= "L" and D = "H", a pulse-like output E is generated from the ungate AND, and an "H" level output is generated from the W-side pulse processing circuit 14A. On the other hand, the output of the O side pulse processing circuit 14B falls to the "L" level, and this falling state is stored in the first storage circuit 16 via the time lag circuit 15. At this time, the output of the OR gate OR, is at the "H" level, and the output of the inverter IN, is "H" level.
” level, the output G of the AND gate AND3 is “
Since the level becomes "H" and the transistor Tr becomes conductive, the motor 7 is driven to rotate. The slack of the safety belt 3 is quickly absorbed by the rotation of the motor 7 (first
0 state in Figure 2). When the slack is absorbed and the safety belt 3 fits the occupant (belt attachment complete state), the W side pulse processing circuit 14A is turned off and its output falls from "H" to "L". The second memory circuits 16 and 18 are cleared and the AND gate AND3 is closed, so the motor drive is stopped (the state shown in FIG. 10).

After the safety belt 3 is pulled out, if the tongue is left unattached to the buckle, the sub-spring 1
Even when the zero torque, the friction and weight of the safety belt 3 are balanced and the belt is not wound, the output of the first memory circuit 16 that stores the state of the D-side pulse processing circuit 148 becomes "H" level. Since the motor 7 is rotated, the safety belt 3 is wound up and stored. At this time, if the belt is wound even slightly by the force of the sub-spring 10, the W-side pulse processing circuit 14A generates an output, so that the belt is wound regardless of the operation of the time lag circuit 15. When the occupant leans forward after wearing the safety belt, the safety belt 3 is pulled out, causing the motor 7 to idle as described above, and when the occupant returns to the original position, the subspring 10 is activated. The belt is wound up by the force, a pulse output is generated from the W-side pulse processing circuit 14A, and the motor 7 is driven to rotate, thereby absorbing the slack generated in the belt 3.

That is, the slack is absorbed by a large torque that is the sum of the torques of the subspring 10 and the motor 7 (states shown in FIGS. 5 and 6). When the slack is sufficiently absorbed, the W-side pulse processing circuit 14A is turned off and its output falls from "H" to "L", so the first and second memory circuits 16 and 18 are cleared and the motor is turned off. lock. When the buckle is released to remove from the attached state, a pulse-like output L is generated from the transition detection circuit 17 due to the output of the buckle switch SW, and an "H" level output is generated from the second memory circuit 18. At this time, ○ Since the output of the side pulse processing circuit 14B is at the "L" level, the AND gate AN
D3 opens, the motor 7 is driven to rotate, and the safety belt 3 is wound with a large torque. At this time, if the safety belt 3 is caught on a seat or the like, the output of the W-side pulse processing circuit 14A falls to the "L" level, so that the drive of the motor 7 is stopped. When the cause of the safety belt 3 being caught is removed, the safety belt 3 is first wound up by the sub-spring 10, so that the W side pulse processing circuit 14
The output of A becomes "H" level, the motor 7 rotates, and the belt is retracted as described above (state shown in Fig. 10, 7).
. When the safety belt 3 is completely retracted and the belt stops moving, the output of the W-side pulse processing circuit 14A changes from "H" to "L".
The motor 7 stops driving, and the belt becomes unused (states shown in FIGS. 8 and 9).

Next, in an emergency such as when the vehicle causes a collision with the occupant wearing the safety belt 3, the G sensor 22 operates at this moment and outputs the signal M, so the control circuit 1
An output is generated from the AND gate AND4 in the second driving transistor Tr2, the second driving transistor Tr2 becomes conductive, and a large current 12 flows.

Therefore, the motor 7 rotates at high speed in the belt winding direction to increase the tension of the safety belt 3. The torque at this time is set to, for example, 45k9.
condition). At this time, the first driving transistor Tr,
When the motor 7 is properly conductive, the current flowing through the motor 7 is 1,112, which further increases the torque. Since the above operations are performed instantaneously, the safety of the occupants is ensured. Generally, when the vehicle stops after a collision occurs, the G-sensor 22 returns to its original state (resets), so the occupant can easily disengage by removing the tongue from the buckle, but the G-sensor 22 does not return to its original state. In case it does not return, the buckle switch SW, signal path or G
If a reset button is attached to one of the signal paths from the sensor 22, no trouble will occur during use. In the above operation explanation, if it takes some time to pull out the safety belt and engage the tongue with the buckle to put on the safety belt (in other words, when the predetermined time has elapsed after the belt has been pulled out), First memory circuit 1
The output of the motor 6 becomes "H" level, the motor 7 is driven, and the belt winding operation is performed, but the winding is started for a predetermined time (i.e., the operation setting time of the W side pulse processing circuit 14A).
Later, since the output of this W-side pulse processing circuit 14A falls from "H" to "L", the motor 7 enters an idling state and has no effect on the subsequent drawing operation.

In the above embodiment, when the safety belt is worn and slack occurs on the belt, the slack is absorbed by the sum of the torque of the sub-spring and the rotational torque of the motor. If the high-torque slack absorption mode causes discomfort to the occupant, the motor rotation signal may be gated using, for example, a buckle switch so that the motor 7 is not driven to rotate when the belt is attached. Further, the configuration of the motor drive system within the control circuit 12 may be as shown in FIG. 11.

That is, the motor 7 is placed on the ground side, the current limiting circuit 19 and the first driving transistor Tr are connected in series between the power supply +V, and the emitter of the second driving transistor Tr2 is connected to the motor 7 side. Connect the collector to DC-DC
Connect to the output power supply +V side of the converter 23. This D
The C-DC converter 23 boosts and outputs a power supply of 10 V (for example, 12 V), and is stabilized by a capacitor Co. As a result, a current 12 larger than the current 1 flowing through the first driving transistor Tr can be passed through the second driving transistor Tr2, and the purpose can be achieved. According to the present invention described in detail above, when the safety belt is worn, only the weak tension of the sub-spring is applied to the belt, so the occupant can drive comfortably without feeling the pressure exerted by the belt, and at the same time, in an emergency, high torque can be applied. It is possible to maintain the safety of passengers by providing tension. Furthermore, since the safety belt can be wound up mainly by the motor, the operation can be made faster and the safety belt can be easily operated. Further, since the control circuit is operated only by the rotational output of the pulser and the operation output of the buckle switch, the circuit configuration is simple, and since the operation is simple, the circuit design is also easy. In addition, since only the idling state and normal rotation state are utilized, low-cost products can be used, and the cost of the apparatus as a whole can be reduced.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view showing one embodiment of the device of the present invention;
3 is a front view of the pulsar used in the same embodiment, FIG. 4 is a block diagram showing an example of the control circuit in the same embodiment, and FIG. 5 is an assembled side view of the same main part. FIG. 6 is an explanatory diagram showing the relationship between the pulsar and the bush point, FIG. 7 a and b are time charts for explaining the operation of the phase detection circuit, and FIG. A circuit diagram showing an example of a transition detection circuit used in the control circuit, FIG. 9 is a time chart for explaining its operation, and FIG. 10 is a diagram showing operating torque for explaining the operation of the embodiment device. FIG. 11 shows a partial modification of the control circuit of the present invention. 1... U-shaped frame, IA, IB...
・Side plate, 2...Shaft, 3...Safety belt, 7...Motor, 8...Deceleration mechanism, 10... Sap spring, 12...
・Control circuit block, 13...phase detection circuit,
14A, 14B...Pulse processing circuit, 15...
・...Time lag circuit, 16, 18... Memory circuit, 17... Transition detection circuit, 19... Current limiting circuit, 20... Pulser, 22... ...
Inertial sensing device, SW.・・・・・・/ゞTsukuru Switch. Figure 1 Figure 2 Figure 3 Figure 5 Figure 6 Figure 7 Figure 4 Figure 8 Figure 9 Figure 10 Figure 11

Claims (1)

[Claims] 1. A safety belt, one end of which is fixed to a belt winding shaft interposed between both sides of the U-shaped frame, is stored so that it can be pulled out and wound up, and the pulled out safety belt is connected between the buckle and the tongs. In the safety belt winding device, which is used by attaching the belt to the belt winding shaft, the safety belt winding device includes a motor attached to the side plate of the frame, a deceleration mechanism that decelerates the rotation of the motor and transmits the rotation to the belt winding shaft, and the belt winding shaft. A sub-spring that provides a relatively weak winding force to the shaft,
a shaft rotation direction detection member that detects the rotation of the belt winding shaft in the belt pull-out direction and the belt winding direction and generates different signals respectively; and a shaft rotation direction detection member that detects the state of engagement between the buckle and the tongue and generates a signal an inertial sensing device that generates a detection signal in the event of a vehicle emergency, and at least when a belt pull-out direction rotation signal is output from the shaft rotation direction detection member and an engagement state signal is generated from the buckle switch. When no signal is generated from the shaft rotation direction detection member, the motor is set to idle, and when there is no engagement state signal from the buckle switch and a belt winding direction rotation signal is output from the shaft rotation direction detection member. A control circuit is provided that sometimes drives the motor to rotate in the belt winding direction, and at the same time controls the motor to rotate at high speed in the belt winding direction when a signal from the buckle switch and a signal from the inertial sensing device are input. A safety belt winding device characterized by: