JPS62181937A - Rotating position detector - Google Patents

Abstract

PURPOSE:To reduce the extent of power consumption after an ignition switch is turned off as well as to detect a handle rotating position accurately, by decreasing an electric current flowing in a handle rotating position detecting sensor as long as the duration of the ignition switch being off. CONSTITUTION:When an ignition switch is turned on, a base current flows into respective transistors Tr1 and Tr2 of each of photointerrupters 13 and 16 via a resistor R3, maintaining its on-state. Therefore, the current flows in each of light emitting diodes 11 and 14 through each route of a resistor R1 and these transistors Tr1 and Tr2 in addition to the route of a resistor R2, whereby a light emitting state is maintained. Accordingly, with a slit disc going across these light emitting diodes 11 and 14, an electric signal corresponding to a handle's rotating position is generated in each of output terminals 17 and 18 of respective phototransistors 12 and 15. On the other hand, when the said switch 6 is turned off, the current flows into these photodiodes 11 and 14 through only the route of the resistor R2, thus the desired end is achievable.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotational position detector having a rotational position detection sensor that transmits an electric signal corresponding to the rotational position of the steering wheel in conjunction with steering wheel steering. It is related to.

[Conventional technology]

BACKGROUND ART Conventionally, in vehicles such as automobiles, various controls linked to the steering wheel are performed using a rotational position detection sensor that sends an electric signal according to the rotational position of the steering wheel. Generally, in a rotational position detector configured in this manner, the supply of power to the rotational position detection sensor is cut off after the ignition switch is turned off in order to reduce power consumption by the battery.

[Problem that the invention seeks to solve]

However, according to such conventional rotational position detectors, after the ignition switch is turned off, for example, when the steering wheel is in the stationary position, the steering wheel rotates in a stress-free direction and then stops. This causes a problem in that the rotational position of the handle cannot be detected. Therefore, there is a risk that the system will malfunction the next time the ignition switch is turned on.

[Means for solving problems]

The present invention has been made in view of the above point, and is designed to reduce the current flowing through the rotational position detection sensor while the ignition switch is off.

[Effect]

Therefore, according to the present invention, after the ignition switch is turned off, the current flowing through the rotational position detection sensor is reduced.

〔Example〕

Hereinafter, the rotational position detector according to the present invention will be explained in detail.

FIG. 1 is a circuit diagram showing one embodiment of this rotational position detector. In the figure, 1 is a rotational position detection sensor attached to a slitted disc (not shown) K linked to the handle, and 6 is an ignition switch. Rotational position detection sensor 1
are light emitting diode 11, phototransistor 12, N
PN) A first photo-interrupter 13 consisting of a transistor Tr and resistors R7 to R5, and a light emitting diode 1.
4. Phototransistor 15, NPN) transistor Tr
2 and a second photo-interrupter 16 consisting of resistors R1 to R5, and a light emitting diode 11.
The cathodes of and 14 are connected to the collectors of transistors 'I'rt and Tr2 via a resistor R1, and the anodes of transistors 'I'rt and Tr2 are connected to a high potential power supply terminal 19.

Further, the cathodes of the light emitting diodes 11 and 14 are also connected to one end of the resistor R2, and the other end of the resistor R2 and the emitter of the transistor 'rr I + 'rr 2 are grounded. Transistors Tri and Tr2
The base of is connected to the ignition switch 6 via the resistor R3.
When the ignition switch 6 is turned on, a pace current flows through the resistor R3 and the transistors Trl and Tr2 are turned on. In addition, the collectors of the phototransistors 12 and 15 are connected to the high voltage power supply terminal 19 via the resistor R5, and the connection point between the phototransistor 12 and the resistor R5 and the connection point between the phototransistor 15 and the resistor R5 are , output terminals 1T and 1 of this rotational position detection sensor 1
8 is connected. Furthermore, the resistance R.

The resistance values of R2 and R2 are determined so that R1<<R2. Even if current flows through the photosensors 11 and 14 through only the resistor R2, the photosensors 11 and 14 are sufficiently It maintains its luminous state and performs its function.

Next, the operation of the rotational position detector configured as described above will be explained. That is, it is assumed that the ignition switch 6 is currently in the on state. At this time, the transistors Tr of the first and second photo interrupters 13 and 16
A pace current flows through resistor R3 and Tr2 to maintain the on state. Due to the breakage, the light emitting diodes 11 and 14 are connected to the resistor R1 in addition to the resistor R2.
, transistor Tr1 and resistor R1, transistor T
A current flows through the r2 path to maintain the light emitting state. Therefore, by the action of a handle interlocking slit disk (not shown) across the light emitting diodes 11 and 14, the output terminals 1T and 18 connected to the collectors of the phototransistors 12 and 15 are connected to the output terminals 1T and 18, which correspond to the rotational position of the handle. A corresponding electrical signal will be generated. In this embodiment, the output terminals 17 and 18 are connected to "1" as shown in FIGS. 2(a) and (b) in conjunction with the steering wheel of the automobile.
A pulsed electric signal having the same waveform is generated which alternates between ``'' level and ``0'' level. That is,
By rotating the handle clockwise (clockwise) from the neutral point, a positive electrical signal centered at 0° will be rotated counterclockwise (clockwise), causing the electrical signal to be centered at θ°. An electric signal in the negative direction is generated, and (a) shows the electric signal generated at the output terminal 17, and (b)
indicates an electrical signal generated at the output terminal 18. The electrical signal generated at the output terminal 17 is 90 degrees ahead of the electrical signal generated at the output terminal 18, and when the handle is at the neutral point, that is, at 0 degrees in FIG. The electrical signal generated at 18 is lower than the "1" level rO
During the falling or rising period when changing to the J level, or from the rOJ level to the "1" level),
The electrical signal generated at the output terminal 17 is at rOJ level.

Therefore, when the ignition switch 6 is turned off in such a state, the transistors Tr1 and Tr2 of the first and second photo-interrupters 13 and 16 are turned off.
is turned off, and current no longer flows through the resistor R1 to the photodiodes 11 and 14, and current flows only through the resistor R2. That is, the current flowing through the photodiodes 11 and 14 is significantly reduced after the ignition is turned off. From then on, this reduced weak current begins to flow through the photodiodes 11 and 14, but since this current is sufficient to maintain the light emitting state of the photodiodes 11 and 14, the current is applied to the output terminals 1T and 18. In this case, even after the ignition switch is turned off, an electric signal linked to the steering wheel will continue to be generated. Therefore, even if the handle is rotated after the ignition switch is turned off, it is possible to detect the rotational position of the handle, and there is a risk that the system will malfunction when the ignition switch 6 is turned on next time. disappears. Moreover, while the ignition switch 6 is off, the current flowing through the photodiodes 11 and 14 is small.
Power consumption by the battery can be reduced.

FIG. 3 is a circuit diagram showing an example of a vehicular cornering lamp system that uses the rotational position detector configured as described above and changes headlights in conjunction with steering wheel steering. Hereinafter, the features of this rotational position detector will be clarified while explaining the configuration of this cornering lamp system.

That is, in FIG. 3, 2 is the rotational position detection sensor 1.
3 is a lamp drive unit that drives a headlamp (not shown) based on the processed signal sent from the processing circuit 2; 4 is a DC power source.

The processing circuit 2 includes Nant gates 21 and 22, and an inverter 2.
3. RIIS flip-flop circuit 24, 25, analogue) 26.27, UP/DOWN counter 2B, and decoder/driver 29.
S flip-flop circuits 24 and 25 are negative logic input OR game) 241 , 242 and 251 , 252
It is composed of many parts. Then, the rotational position detection sensor 1
The electrical signal generated at the output terminal 1T of the Nantes Gate 2
1 and 22, and the reset terminals 24r and 25r of the RIIS flip-flop circuits 24 and 25, the electrical signal generated at the output terminal 18 of the rotational position detection sensor 1 is input to the AND gate. 26
one end of the Nant gate 22, the other end of the inverter 23
It is now entered as . The electrical signal output from the inverter 23 is input to the other end of the Nandt gate 21 and one end of the AND gate 27. Furthermore, the outputs of the Nant gates 21 and 22 are input to the R@S flip-flop circuits 24 and 250 set terminals 24g and 25m, and the outputs of the R-S flip-flop circuits 24 and 25 are input to the Q output terminals. AND gate 2 via 244 and 25q
6 and 2T.

Then, the outputs of AND gates 26 and 27 are UP/D
It is designed to be input to the up input terminal 28u and down input terminal 28d of the OWN counter 28, and the UP
/DOWN counter 28 is connected to input terminal 28u or 28
Every time a "1" level signal is input to d, the count value is increased or decreased, and a digital signal corresponding to the count value is sent to the input terminals 29A to 29D of the decoder/driver 29 via the output terminals 28A to 28D. It is designed to be sent to

The decoder/driver 29 receives this digital signal, selects a predetermined output terminal among the output terminals 29a to 290, and sets the level to "0". That is, at the eight points in Figure 2, UP/D
The count value in the OWN counter 28 is set to zero, and at this time the decoder/driver 29 selects the output terminal 29h and sets only the level of this output terminal 29h to the rOJ level. And U
Every time the count value increases by 1 in the P/DOWN counter 28, the output terminal '29 becomes ``0'' level.
The numbers are increased sequentially from h to 29g, 29f-11, and 29a. In addition, the UP/DOWN counter 28
Each time the count value in decreases by 1 from zero, r
Connect the output terminal that becomes OJ level from 29h to 29i, 2
9j...29o, and so on.

It goes without saying that even during countdown after count-up or count-up after countdown, the output terminals that reach the "O" level are successively carried down or carried forward to the adjacent output terminals. Then, the output terminal 29 of the decoder/driver 29
Since m and 29b are the output terminals 2 of the processing circuit 2, 29
c and 29d to output terminal 2b, 29e and 29f
is at output terminal 2C, 29g.

29h and 291 are connected to output terminal 2d, 29j and 2
9k is connected to the output terminal 2. 291 and 29m are connected to the output terminal 2f, and 29n and 29o are connected to the output terminal 2g.

Thus, the sliding contacts 34b where the output terminals 21 to 2g of the processing circuit 2 slide on the semicircular band-shaped conductor patterns 32 and 33 formed on the sliding board 31 of the lamp drive unit 3.
A sliding contact 34m adjacent to the sliding contact 34b is connected to the positive polarity side of the DC power supply 4 via the coil 351 of the relay 35. Further, the sliding contact 34i adjacent to the sliding contact 34h is also connected to the positive polarity side of the DC power supply 4 via the coil 361 of the relay 36, and the diodes 37 and 38 are connected in parallel to the coils 351 and 361. has been done. The normally open/normally closed contacts 352 of the relay 35 and the normally open/normally closed contacts 362 of the relay 36 are connected to both connection ends of the DC motor 39, and when the relay 35 is energized, the normally open/normally closed contacts 352 of the relay 35 and the normally open/normally closed contacts 362 of the relay 36 are connected. The common terminal 352C of the normally closed contact 352 and the normally open contact terminal 352a are electrically connected, and the positive polarity side of the DC power supply 4 is connected to one end of the DC motor 39.

Also, when the relay 36 is in the energized state, it is normally open.
Common terminal 362C of normally closed contact 362 and normally open contact terminal 3
621 is electrically connected to the other end of the DC motor 39, and the DC power supply 4 is connected to the other end of the DC motor 39.
The positive polarity side of is connected. Suwachi,
Normally, the normally open/normally closed contacts 352 and 362 are in a conductive state between their common terminals 352c and 362c and the normally closed contact terminals 352b and 362b, and at this time, the DC motor 3
Both ends of 9 are grounded. Then, when DC power is supplied to the DC motor 39 through the normally open/normally closed contacts 352, the motor rotates the lamp drive shaft 5 clockwise (clockwise rotation in the figure). Along with the rotation, the conductive patterns 32 and 33 are also rotated clockwise together with the sliding substrate 31. Further, when DC power is supplied to the DC motor 39 through the normally open/normally closed contacts 362, the lamp drive shaft 5 rotates counterclockwise, and as the lamp drive shaft 5 rotates counterclockwise, the conductor pattern 32 and 33 rotate counterclockwise integrally with the sliding base plate 31.

It goes without saying that the irradiation direction of the headlight changes by clockwise and counterclockwise rotation of the lamp drive shaft 5, and by clockwise rotation of the lamp drive shaft 5,
The irradiation direction of the headlights is rotated to the right when viewed from the driver's seat, and the lamp drive shaft 5 is rotated to the left, so that the irradiation direction of the headlights is rotated to the left.

Next, the operation of the vehicle cornering lamp system configured as described above will be explained. That is, it is assumed that the vehicle is currently traveling straight and the steering wheel is located at the neutral point (point N in FIG. 2).

At this time, the count value in the UP/DOWN counter 2B is zero, and the decoder/driver 29 outputs m
Only h is expressed as "0" level. In other words, the output terminals 29a to 29g and the output terminals 291 to 29o are all at the "1" level, and the conductor patterns 32 and 3
Sliding contacts 34b to 34d and 34f to 34 in contact with 3
g is at the rlJ level.

Therefore, power is not supplied to relays 35 and 36, and DC motor 39 does not rotate. At this time, the irradiation direction of the headlights and headlights is stopped facing forward.

Therefore, when the steering wheel is turned clockwise and right steering is started from such a state, the photo-interrupters 13 and 16
The electrical signals sent by the terminal are at the "1" and "0" levels (point a in FIG. 2). As a result, the output of the Nant gate 21 changes from the "1" level to the rOJ level, ij)
, the R-S flip-flop circuit 24 is set, and the Q output terminal 24q becomes "1" level. Then, when the right steering is further performed and point b in FIG. UP input terminal 2 of UP/DOWN counter 28
A “1” level signal is input to 3u, UP/DOWN
The count value in the counter 28 increases by one. This is a decoder.

The /driver 29 moves the signal at the 9rOJ level that has been sent out so far from the output terminal 29h to the output terminal 29g and sends it out. However, since the output terminal 29, like the output terminal 29h, is connected to the output terminal 2d of the processing circuit 2, no power is supplied to the motor 39, and the headlight remains facing forward. continue. and,
Further, by continuing to steer to the right, the output terminals 17 and 1B of the rotational position detection sensor 1 become "0" and "1" levels (0 point in FIG. 2), and the R-S flip-flop circuit 24 becomes The reset terminal 24r becomes "0" level, the flip-flop is reset, and the Q output terminal 24q becomes "0" level.
0'' level and prepare for the next count. However,
When the point d in FIG. 2 is reached, the output of the Nantes gate 21 becomes "
The level changed from ``1'' level to r゛OJ level, the R-S flip-flop circuit 24 was not set, and the Q output terminal 24q became ``1'' level again, reaching point e in Figure 2. At this point, the output of the AND gate 26 is at the "1" level, and the count value in the 9 UP/DOWN counter 28 is further incremented by one. In order to increase this count value, the decoder/driver 29 raises the "0" level signal that had been sent out until then and sends it out from the output terminal 29g to the output terminal 29f, and sends it out to the coil 3 of the relay 35.
Sliding contact 34a at 51, conductor pattern 32° sliding contact 3
4d, Tl'tffb flows at the output terminal 2c.

By energizing the coil 351, the common terminal 352C of the normally open/normally closed contact 352 and the normally open contact terminal 35
2a, the DC motor 39 rotates and the lamp drive shaft 5 rotates clockwise. This clockwise rotation of the lamp drive shaft 5 moves the irradiation direction of the headlight clockwise, and the sliding board 31 rotates clockwise while sliding the sliding contacts 34a to 34i on its conductor patterns 32 and 33. . When the sliding contact 34d moves away from the conductor pattern 32, the energization of the coil 351 of the relay 35 is released, and the common terminal 352C of the normally open/normally closed contact 352 and the normally open contact terminal 352a are connected to each other. becomes non-conductive υ, and the power supply to the DC motor 3S is cut off. The DC motor 39 rotates a little due to inertia and then stops, and the sliding board 31 stops with the sliding contact 34d arranged approximately at the center of the opposing gap 31m between the conductor patterns 32 and 33, as shown in FIG. do. From now on, by continuing to steer to the right, the UP/DOWN
The count value in the counter 28 increases sequentially, and the position of the "0" level signal sent out by the decoder/driver 2S moves to the output terminals 29, 29d, . . . , 29a,
As a result, the DC motor 39 rotates intermittently, and the irradiation direction of the headlight moves clockwise in stages.

Next, the operation when the handle is rotated to the left from the neutral point will be explained. That is, when steering to the left from point N in FIG. 2, both the output terminals 1T and 18 of the rotational position detection sensor 1 go to the "1" level (point f in FIG. 2), and the output of the Nantes gate 22 becomes "1". O” level, R-S
The flip-flop circuit 25 is set, and the Q output terminal 2
5q becomes the "1" level. When the point g in FIG. 2 is reached, the output terminals 17 and 1B become "1" and "0".
The level is reached, and the power of both ANDGATE 27 is "1".
level, a “1” level signal is input to the down input terminal 28d of the UP/DOWN counter 28, and the UP
/DOWN counter 28 counts down the count value by one. As a result of this countdown, the decoder/driver 29 lowers the "0" level signal that it had been sending out until then and sends it out from the output terminal 29h to the output terminal 291. When point h in FIG. 2 is reached, both output terminals 17 and 1B become rOJ level, and R-
The 8 flip-flop circuit 25 is reset and the Q output terminal 25q becomes rOJ level in preparation for the next count. However, when the point in Figure 2 is reached, UP/DO
The count value in the WN counter 2B further counts down by 1, and the decoder/driver 29 sends "
0'' level signal position is carried down to the output terminals 291 to 29j. Thereby, the sliding contact 341 degree conductor pattern 33. Current flows through the path between the sliding contact 34f and the output terminal 2e, and the normally open/normally closed contact 362
When the common terminal 362c and the normally open contact terminal 362& are not in a conductive state, the DC motor 39 rotates and the lamp drive shaft 5
rotates to the left. This counterclockwise rotation of the lamp drive shaft 5 moves the irradiation direction of the headlight counterclockwise, and the sliding board 31
rotates counterclockwise, the sliding contact 34f separates from the conductor pattern 33, the energization of the coil 361 of the relay 36 is released, and the common terminal 362c of the normally open/normally closed contact 362 and the normally open contact terminal 362a are connected. It becomes non-conductive and the power supply to the DC motor 39 is cut off.

As a result, the DC motor 39 rotates slightly due to inertia and then stops. Thereafter, in the same manner, by continuing to steer to the left, the count value in the UP/DOWN counter 28 decreases sequentially, and the rO output from the decoder/driver 29 is
J level signal position is output terminal 29k, 29t...
・29o and the lower position rotate, whereby the DC motor 39 rotates intermittently, and the irradiation direction of the headlight moves to the left in stages.

In this embodiment, the stepwise swing angle of the headlight irradiation direction is set to 10 degrees, so the headlight irradiation direction can be swung left and right by a maximum of 30 degrees each. . In order to obtain such a deflection angle, the sliding contacts 34b to 34h are arranged at equal angular intervals, and the intervals are sufficient to swing the irradiation direction of the headlight by 10 degrees in one step. In addition, in this embodiment, the operation was explained when the handle was rotated clockwise and counterclockwise from the neutral point, but the case where the steering wheel is rotated clockwise and then counterclockwise, or when it is rotated counterclockwise and then clockwise. Needless to say, the count value in the UP/DOWN counter 28 is sequentially counted down or counted up, and the irradiation direction of the headlight changes according to this count value.

As described above, according to the cornering lamp system according to the present embodiment, since the direction of travel can be illuminated in conjunction with the steering wheel of the automobile during cornering, safety during driving is ensured. Furthermore, even after the automobile is stopped and the ignition switch 6 is turned off, the light emitting diodes 11 and 14 of the photo interrupters 13 and 16 continue to display 1! Since the current flows and performs its function, even if the handle rotates after the ignition switch is turned off, the UP/DOWN counter 2
8 does not occur, and even after the ignition switch is turned on, accurate headlamp irradiation direction variable operation can be achieved in conjunction with steering wheel steering. In addition, the current flowing through the developed photodiodes 11 and 14 when the ignition switch is turned off is small.
Battery power consumption is significantly reduced.

〔Effect of the invention〕

As explained above, according to the rotational position detector according to the present invention, the current flowing through the rotational position detection sensor is reduced while the ignition switch is turned off, so power consumption after the ignition switch is turned off is reduced, and the steering wheel It becomes possible to accurately detect the rotational position.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing an embodiment of the rotational position detector according to the present invention, Fig. 2 is an output waveform diagram of this rotational position detector, and Fig. 3 is a cornering diagram for a vehicle using this rotational position detector. FIG. 4, which is a circuit diagram of the lamp system, is a state diagram illustrating the operation of the sliding board in this cornering lamp system. 1...Rotational position detection sensor, 11.14...Light emitting diode, 12.15--Φ phototransistor, 1311--Fist first photo interrupter, 16.
Φ-・Second photo interface 77'/, 6...
Ignition switch, Trl+ Tr2 a a
a m NPN) transistor, R, ~R5...resistance. Patent applicant: Koito Seisakusho Co., Ltd. Agent: Masaki Yamakawa (11 or 2 people) Figure 1 Figure 2

Claims (1)

[Claims] In a rotational position detector comprising a rotational position detection sensor that transmits an electric signal according to the rotational position of the steering wheel in conjunction with steering of the steering wheel, the current flowing through the rotational position detection sensor is reduced while the ignition switch is off. A rotational position detector characterized by being provided with current consumption reducing means.