JPH10991A - Horn controller of automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a horn controller installable in a steering wheel without increasing the channel number of a spiral cable. SOLUTION: An FET 25 is operated on or off, driving an electromagnetic relay 26 into pulsation. In brief, when this FET 25 is turned on, a power source is supplied to this relay 26, but when it is off, the power source is supplied to a power condenser 24. Accordingly, a power line of a horn control circuit 8 and a signal line connecting the horn control circuit 8 and a horn 10 both jointly use one piece of wiring 9a constituting a spiral cable 9. Since watt consumption in a microcomputer 21 and a constant voltage power circuit 22 is small, in time of the FET 25 being turned off, any electric current is not energized to the input side of the electromagnetic relay 26, therefore a horn body 27 will not sound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horn control device for an automobile.

[0002]

2. Description of the Related Art A horn control system for a vehicle disclosed in US Pat. No. 5,309,135 has been proposed. In this system, a flexible substrate to which a flexible potentiometer is adhered is adhered to an inner surface of a steering wheel hub cover. Flexible potentiometers consist of a variable resistance conductive material whose resistance changes significantly when the conductive material is bent. Therefore, when the driver pushes the outside of the hub cover, the flexible potentiometer is deformed,
The resistance value changes. The flexible potentiometer is connected to the horn control circuit. The horn control circuit detects a change in the resistance of the flexible potentiometer and activates the horn according to the change in the resistance. Accordingly, when the driver pushes the outside of the hub cover with a certain force or more, the horn sounds.

[0003]

By the way, various switches such as a cruise control switch and a car telephone are mounted on the steering wheel. The connections between the various switches and the circuits provided on the vehicle body side include:
Spiral cables are used. The spiral cable is composed of multiple wiring materials, and the steering wheel
It is arranged on the outer periphery of the shaft.

In the system disclosed in the above publication, it is necessary to connect a power supply line for supplying power to the horn control circuit. In addition, it is necessary to connect the horn control circuit and the horn attached to the vehicle body with a signal line. Therefore, when the horn control circuit is provided inside the hub cover, a spiral cable must be used as the power supply line and the signal line. Therefore, it is necessary to increase the number of wiring members (that is, the number of channels) of the spiral cable by the power supply lines and the signal lines.

However, since the spiral cable is used for wiring the above-mentioned various switches, it is difficult to increase the number of channels. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a horn control device for an automobile in which a horn control device can be provided on a steering wheel without increasing the number of spiral cable channels. Is to provide.

[0006]

According to a first aspect of the present invention, there is provided an electromagnetic horn (10) provided on a vehicle body side and a horn drive control means (11, 21, 21) provided on a steering wheel (W). 24, 25), wiring (9a) commonly used for supplying power to the electromagnetic horn and the drive control means, and that the wiring constitutes a spiral cable (9) connecting the vehicle body and the steering wheel. I do.

According to a second aspect of the present invention, there is provided an electromagnetic horn (10) provided on the vehicle body side, a switching element (25) for pulse-driving the electromagnetic horn, and a horn operating means provided on the steering wheel (W). (11) and control means (21) for driving and controlling the switching element according to the operation of the horn operating means, charged when the electromagnetic horn is not energized, discharged when the electromagnetic horn is energized, and supplying power to the control means during the discharge (24) and wiring (9) commonly used for energizing the electromagnetic horn and charging the capacitor.
a) and its wiring constitutes a spiral cable (9) connecting the vehicle body and the steering wheel, and the charging time of the capacitor is set shorter than the recovery time of the electromagnetic horn. And

According to a third aspect of the present invention, there is provided a horn (10) provided on a vehicle body side, and the horn is provided with an electromagnetic relay (2).
A switching element (25) for pulsating the electromagnetic relay by controlling sounding when the electromagnetic relay is energized, and controlling energization of the electromagnetic relay; and a horn operating means provided on the steering wheel (W). (11)
A control means (21) for driving and controlling the switching element according to the operation of the horn operating means; a capacitor which is charged when the electromagnetic relay is not energized, discharged when the electromagnetic relay is energized, and supplies power to the control means when the electromagnetic relay is discharged ( 24)
Wiring (9a) shared for energizing the electromagnetic relay and charging the capacitor, the wiring constitutes a spiral cable (9) connecting the vehicle body and the steering wheel, and the electromagnetic relay and the capacitor are connected via the wiring. A battery (BATT) to be connected and the charging time of the capacitor is set to be shorter than the return time of the electromagnetic relay.

(Operation) According to the first aspect of the present invention, one wire constituting the spiral cable is commonly used for supplying power to the electromagnetic horn and the drive control means.

According to the second aspect of the present invention, one wire constituting the spiral cable is commonly used for energizing the electromagnetic horn and charging the capacitor. Further, when the electromagnetic horn is energized, the control means is supplied with power by discharging the capacitor. And the charging time of the capacitor is
Since the time is shorter than the return time of the electromagnetic relay, even when the electromagnetic horn is not energized in accordance with the driving of the switching element, its sounding is maintained.

According to the third aspect of the present invention, one wire constituting the spiral cable is commonly used for energizing the electromagnetic relay and charging the capacitor. Further, when the electromagnetic relay is energized, the control unit is supplied with power by discharging the capacitor. And the charging time of the capacitor is
Since the time is shorter than the return time of the electromagnetic relay, even when the electromagnetic horn is not energized in accordance with the driving of the switching element, its sounding is maintained.

[0012]

According to the invention as set forth in any one of the first to third aspects, the horn control of the automobile can provide the horn control device on the steering wheel without increasing the number of spiral cable channels. An apparatus can be provided.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a plan view of the steering wheel W in the present embodiment, and FIG. 3 is a cross-sectional view taken along line II of FIG.

As shown in these figures, the steering wheel main body 101 of the steering wheel W has an annular ring portion 102, a hub cover 4 disposed at the center of the ring portion 102, and three extending from the ring portion 102. And a spoke portion 104. Also, the ring part 102
Is composed of a ring core 105 made of, for example, a steel pipe and a covering 107a that covers the same.
Reference numeral 04 denotes a spoke portion core bar 106 made of a light-weight die-cast metal such as an aluminum alloy, and a cover 107b that covers them. Coatings 107a, 1
07b and the hub cover 4 are integrally formed of a soft synthetic resin material (for example, polyurethane foam). The steering wheel main body 101 is fixedly attached to the boss 108. This mounting structure will be described later in detail.

On the other hand, a storage recess 111 surrounded by a cover 107b is formed below the hub cover 4. In the storage recess 111, the flexible board 7, the horn control circuit 8, and the airbag device 113 are provided. The flexible substrate 7 is adapted to deform as the hub cover 4 is deformed.

The airbag device 113 includes a bag-shaped airbag 114 folded and stored, and an airbag 114.
115 for supplying gas for inflation to the
And a bag holder 116 for holding and fixing the airbag 114 and the inflator 115. The bag holder 116 is fixed to the spoke portion core bar 106, and a part of the
The bracket 116a is fixed to the steering wheel main body 101 (also to the boss 108 in the present embodiment) as described later.

Next, the mounting structure of the steering wheel W will be described in detail. First, the mounting structure of the boss 108 will be described. An external thread (not shown) is formed at the most distal end of the steering wheel shaft 6, and a serration 132 and a tapered surface 133 are formed below the external thread. The serration 132 of the steering wheel shaft 6 is formed with a predetermined number (generally, about 30) of teeth 132a. The above-mentioned boss 108 is inserted through the tip of the steering wheel shaft 6, and the boss 108 is fixed by a nut 134 screwed to the male screw portion.

The boss 108 is composed of a steel part 108a located on the inner peripheral side and an aluminum part 108b made of die-cast aluminum located on the outer peripheral side of the steel part 108a, and these are integrally formed. I have. Serrations 120 corresponding to the serrations 132 and the tapered surface 133 of the steering wheel shaft 6 are provided on the inner peripheral surface of an insertion hole (steering wheel shaft insertion hole) 119 provided substantially at the center of the boss 108 (steel portion 108a). A tapered surface 121 is formed. Further, a rib 122 protruding upward is integrally formed on a part of the upper surface of the boss 108. This rib 122
Has a bolt hole 123 formed therein. In addition, Boss 1
08 is integrally formed with a connecting portion 124 extending obliquely upward.

On the other hand, the steering wheel body 10
Among the three spoke cores 106 in FIG. 1, one core 106A located on the driver side is connected to a connecting part 124 extending from the boss 108 via a hinge part 125 so as to be relatively rotatable. ing. In other words, the C-shaped gripping portions 126 are provided on both sides of the distal end portion of the spoke portion core bar 106A.
Are integrally formed. On the other hand, the distal end portion of the connecting portion 124 is integrally formed with a columnar gripped portion 127 extending in a direction orthogonal to the connecting portion 124. The hinge portion 125 is configured by fitting the gripped portion 127 into the grip portion 126. For this reason, the spoke portion core bar 106A and, consequently, the steering wheel main body 101 can rotate about the hinge portion 125 with respect to the connecting portion 124 and, consequently, the boss 108.

Further, in the present embodiment, the two spoke cores 106 except for the one spoke core 106A are connected to each other at substantially their respective distal ends, and the connected spoke cores 106B Is composed. A bolt hole 128 similar to the bolt hole 123 is also provided at a substantially central portion of the connecting spoke portion core bar 106B.
Are formed. Then, both bolt holes 123, 128
With the two spokes aligned with each other,
06B and the rib 122 of the boss 108 are screwed and fixed by bolts 29A and nuts 29B. The bolt 129A and the nut 129B constitute a fastening unit in the present embodiment. In this embodiment, a spiral cable 9 composed of a plurality of wiring members is provided on the outer periphery of the steering wheel shaft 6. Furthermore, the steering wheel body 1
01 and a lower cover 136 made of resin so as to surround the lower side.
Are arranged.

The horn control circuit 8 is connected to a horn 10 attached to a vehicle body (not shown) through a single wire 9a constituting a spiral cable 9. The steering wheel shaft 6 is grounded to the vehicle body.

FIG. 4 is a plan view of the flexible substrate 7. The shape of the flexible substrate 7 conforms to the shape of the inner surface of the hub cover 4. Flexible substrate 7
A flexible potentiometer 11 is adhered to the surface of. The flexible potentiometer 11
Plurality of printed resistors 12 made of conductive material with variable resistance
And a printed wiring 1 for connecting each printed resistor 12 in series
And 3. When the flexible substrate 7 is deformed, each printed resistor 12 bends, and the resistance value of each printed resistor 12 changes greatly. When the flexible substrate 7 returns to its original shape, each printed resistor 12 also returns to its original shape, and the resistance value of each printed resistor 12 also returns to its original value.

FIG. 1 shows a block circuit diagram of the present embodiment. The horn control circuit 8 includes a microcomputer 21, a constant voltage power supply circuit 22, a diode 23, a power supply capacitor 24, a field effect transistor (FET;
d Effect Transistor) 25. Each member (21, 2) constituting the horn control circuit 8
4, 25) are grounded to the vehicle body via the steering wheel shaft 6.

Wiring 9a constituting spiral cable 9
From the diode 23 via the power supply capacitor 24,
It is connected to a constant voltage power supply circuit 22. Also, the wiring 9a
Are grounded from the source / drain terminals of the FET 25 to the vehicle body via the steering wheel shaft 6.

The other wires 9b constituting the spiral cable 9 include various switches (not shown) such as a cruise control switch and a car phone attached to the steering wheel W, and various circuits (not shown) provided on the vehicle body side. ) And connected.

The microcomputer 21 is supplied with a constant voltage Vc from a constant voltage power supply circuit 22. And
The microcomputer 21 detects a change in the resistance value of the flexible potentiometer 11 and controls the ON / OFF operation of the FET 25 according to the change in the resistance value. That is, when the resistance value of the flexible potentiometer 11 exceeds a predetermined value within a predetermined time, the microcomputer 21 turns on and off the FET 25 at a constant cycle,
When the resistance value of the flexible potentiometer 11 becomes less than the predetermined value, the FET 25 is turned off.

The clock frequency for operating the microcomputer 21 is set to a minimum value at which a necessary operation is ensured. Further, the constant voltage power supply circuit 22 is configured to reduce the bias current. In particular,
When the constant voltage power supply circuit 22 is configured using a three-terminal regulator, a three-terminal regulator having a small bias current is selectively used. By doing so, the circuits 21, 22
Power consumption can be reduced.

The horn 10 includes an electromagnetic relay 26 and a horn main body 27. One end (node A) on the input side of the electromagnetic relay 26 is connected to the positive terminal of the battery BATT, and the other end (node B) on the input side is connected to the wiring 9a. The output side of the electromagnetic relay 26 is the horn body 2
7 is connected. The negative terminal of the battery BATT is grounded to the vehicle body. Therefore, the electromagnetic relay 26
When the input-side node B is grounded, a current flows between the input-side nodes A and B, and a current also flows to the output side. The horn body 27 is designed to sound when energized.

Next, the operation of the present embodiment configured as described above will be described with reference to the timing chart shown in FIG. When no external force is applied to the hub cover 4 (normal state), the flexible substrate 7 is not deformed, and the resistance value of each printed resistor 12 is less than the predetermined value. Therefore, the microcomputer 21 uses the FET
Turn off 25.

When the FET 25 is turned off, the electromagnetic relay 26
(Ie, the anode of the diode 23) is in a high impedance state,
Are connected to the power supply capacitor 24 and the constant voltage power supply circuit 22 from the wiring 9a via the diode 23. Therefore, a current flows from the diode 23 to the ground via the microcomputer 21 and the constant voltage power supply circuit 22, and a current also flows between the nodes A and B on the input side of the electromagnetic relay 26.

Here, the current flowing from the diode 23 to the ground via the microcomputer 21 and the constant voltage power supply circuit 22 is set to be smaller than the minimum current value required for driving the electromagnetic relay 26. Keep it. Specifically, as described above, the power consumption of the microcomputer 21 and the constant voltage power supply circuit 22 is reduced.

In this way, in a normal state,
Sufficient current is not supplied to the nodes A and B on the input side of the electromagnetic relay 26, and the electromagnetic relay 26 is not driven. As a result, the horn body 27 does not sound.

In this normal state, a current flows through the diode 23, so that the power supply capacitor 24 is charged and ready for discharging in a period T1 described later. When the driver pushes the outside of the hub cover 4 with a certain force or more, the hub cover 4 is deformed, and the flexible substrate 7 is also deformed with the deformation, and each printed resistor 12 is bent with the deformation, and each printed resistor 12 is bent. 12 greatly changes.

When the resistance value of the flexible potentiometer 11 becomes higher than a predetermined value within a predetermined time, the microcomputer 21 turns on and off the FET 25 at a constant cycle. When the resistance value of the flexible potentiometer 11 becomes lower than the predetermined value, The FET 25 is turned off. That is, as shown in FIG. 5, when the resistance value of the flexible potentiometer 11 becomes equal to or more than a predetermined value within a predetermined time, the FET 25 is turned on only for a period T1.
The FET 25 is turned off only for the period T2. The on / off operation of each of the periods T1 and T2 is repeated until the resistance value of the flexible potentiometer 11 becomes less than the predetermined value.

The flexible potentiometer 11
The resistance value changes not only when an external force is applied but also when the ambient temperature changes. However, the change in the resistance value of the flexible potentiometer 11 when the temperature changes is smaller and more gradual than that when an external force is applied. Therefore, flexible
Based on the magnitude of the resistance value of the potentiometer 11 and the speed at which the resistance value changes, it is possible to determine whether the change in the resistance value is due to an external force or a temperature change. The microcomputer 21 performs this determination operation, and turns on and off the FET 25 only when the resistance value of the flexible potentiometer 11 changes due to an external force.

In a period T1 shown in FIG.
Is turned on, the node B on the input side of the electromagnetic relay 26 enters a low impedance state, and the FET 25
And is grounded to the vehicle body via the steering wheel shaft 6. Therefore, the nodes A and B on the input side of the electromagnetic relay 26 are connected between both terminals of the battery BATT and are energized. As a result, the horn body 27 is energized and sounds.

In this period T1, since no current flows through the diode 23, the power supply capacitor 24 is not charged, and the electric charge stored before that is discharged. Constant voltage power supply circuit 2
2 is a constant voltage V from the discharge current of the power supply capacitor 24.
c is generated and supplied to the microcomputer 21.
Since the discharge current of the power supply capacitor 24 is stopped by the diode 23, it does not flow into the wiring 9a.

Subsequently, during a period T2 shown in FIG.
When the ET 25 is turned off, the node B on the input side of the electromagnetic relay 26 enters a high impedance state, and is connected to the power supply capacitor 24 and the constant voltage power supply circuit 22 via the wiring 9 a via the diode 23. Therefore, the electromagnetic relay 26
No sufficient current is supplied to each of the nodes A and B on the input side. Therefore, by making the period T2 shorter than the relay return time of the electromagnetic relay 26, the sound of the horn main body 27 is maintained even when the nodes A and B are not energized.

In this period T2, since the current flows through the diode 23, the power supply capacitor 24 is charged, and is prepared for the discharge in the period T1. As described above, according to the present embodiment, the following operations and effects can be obtained.

(1) The power supply line to the electromagnetic relay 26 is a positive terminal of the battery BATT → the node A on the input side of the electromagnetic relay 26 → the node B on the input side → the wiring 9a → FET.
25 → Steering wheel shaft 6 → Battery BA
This is the negative terminal of TT.

On the other hand, the power supply line to the constant voltage power supply circuit 22 (that is, the microcomputer 21) is a positive terminal of the battery BATT → the node A on the input side of the electromagnetic relay 26 → the node B on the input side → the wiring 9a → Diode 23
→ power supply capacitor 24 → steering wheel shaft 6 → negative terminal of battery BATT.

When the FET 25 is turned on, a power supply line to the electromagnetic relay 26 is formed.
Is off, a power supply line to the power supply capacitor 24 is formed. That is, the electromagnetic relay 26 and the microcomputer 21 share the wiring 9a as a power supply line. The on / off operation of the FET 25 is controlled by the microcomputer 21. That is,
A power supply line to the electromagnetic relay 26 functions as a signal line connecting the horn control circuit 8 and the horn 10. A power supply line to the microcomputer 21 can be regarded as a power supply line of the horn control circuit 8.

Accordingly, the power supply line of the horn control circuit 8 and the signal line connecting the horn control circuit 8 and the horn 10 share one wire 9a constituting the spiral cable 9. Become. for that reason,
It is not necessary to increase the number of wiring members (that is, the number of channels) of the spiral cable 9.

(2) When no external force is applied to the hub cover 4 (normal state), the current flowing from the diode 23 to the ground via the microcomputer 21 and the constant voltage power supply circuit 22 is small. Is not sufficiently supplied to the input side, and the horn body 27 does not ring.

(3) The electromagnetic relay 26 is pulse-driven by turning on and off the FET 25. That is, when the FET 25 is off, the power supply capacitor 24
Is charged, and power is not supplied to the electromagnetic relay 26.
Therefore, the horn 10 is caused to sound also in the period T2 by setting the off time of the FET 25 (= period T2 = charge time of the power supply capacitor 24) shorter than the relay return time of the electromagnetic relay 26. Therefore,
The sound of the horn 10 is not interrupted by the on / off operation of the FET 25.

(4) The power consumption of the microcomputer 21 and the constant voltage power supply circuit 22 is small. Also, FET2
Reference numeral 5 denotes a voltage driving element, and thus a driving current (gate current)
Is not required. Therefore, the power consumption of the horn control circuit 8 can be reduced.

(5) From the above (4), the power supply capacitor 2
4 can be made smaller. Therefore, Horn
Since the external dimensions of the control circuit 8 are also reduced and the space is not taken up in the hub cover 4, the horn control circuit 8 does not become an obstacle even when an airbag is mounted in the hub cover 4.

The above embodiments may be modified as described below, and the same operation and effect can be obtained in such a case. (1) Printed resistor 12 made of a conductive material having a variable resistance value
Is replaced with a piezoresistive element composed of a semiconductor strain gauge.

(2) Flexible potentiometer 1
1 is replaced by another type of pressure-sensitive sensor (piezoelectric transducer, capacitor pickup, etc.) for detecting an external force applied to the hub cover 4.

While the embodiments have been described above, technical ideas other than the claims that can be grasped from the embodiments will be described below together with their effects. (B) In the horn control device for an automobile according to claim 2 or 3, the horn operating means is bonded to a flexible substrate (7) bonded to an inner surface of a hub cover (4) of a steering wheel (1). Flexible
A potentiometer (11), said control means (2)
1) A horn control device for an automobile, which detects that the horn operating means has been operated according to a change in the resistance value of the flexible potentiometer.

In this way, when the user pushes the outside of the hub cover, the resistance value of the flexible potentiometer changes, and the control means can detect that the horn operating means has been operated.

(B) In the horn control device for an automobile according to claim 2 or 3, the control means (21)
A horn control device for an automobile, wherein a current flowing through the horn is smaller than a current required for driving the horn (10).

In this way, it is possible to prevent the horn from sounding when the horn is not driven by the switching element. (C) The horn control device for an automobile according to claim 2 or 3, wherein the switching element (25) is a voltage drive element.

With this configuration, since no current is required for driving the switching element, the power consumption of the device can be reduced. By the way, in this specification, a switching element includes not only an FET but also a bipolar transistor, an SIT (Static Induction Transistor), a thyristor, and the like.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram of one embodiment.

FIG. 2 is a plan view of the steering wheel according to the embodiment.

FIG. 3 is a partial cross-sectional view of the steering wheel according to the embodiment;

FIG. 4 is a plan view of a flexible substrate according to one embodiment.

FIG. 5 is a timing chart for explaining the operation of the embodiment.

[Explanation of symbols]

W: steering wheel, 9: spiral cable,
9a: wiring, 10: horn, 11: flexible potentiometer as drive control means or horn operation means, 21: microcomputer as drive control means or control means, 24: capacitor as drive control means, 25 ... switching element, 26 ... Electromagnetic relay

Claims (3)

[Claims] An electromagnetic horn (10) provided on a vehicle body side
A horn drive control means (11, 21, 24, 25) provided on the steering wheel (W); a wiring (9a) commonly used for power supply to the electromagnetic horn and the drive control means; A horn control device for an automobile, comprising: a spiral cable (9) connecting the steering wheel and the steering wheel. 2. An electromagnetic horn (10) provided on a vehicle body side.
And a switching element (25) for pulse driving the electromagnetic horn
A horn operating means (11) provided on the steering wheel (W); a control means (21) for driving and controlling the switching element according to the operation of the horn operating means; A capacitor (24) that discharges when energized and supplies power to the control means at the time of discharge, wiring (9a) shared for energizing the electromagnetic horn and charging the capacitor, and the wiring connects the vehicle body and the steering wheel. A spiral cable (9), wherein the charging time of the capacitor is set shorter than the return time of the electromagnetic horn. 3. A horn (10) provided on a vehicle body side,
The horn includes an electromagnetic relay (26), which sounds when the electromagnetic relay is energized, and controls the energization of the electromagnetic relay to provide a switching element (25) for driving the electromagnetic relay in pulses, and a steering wheel (W). A horn operating means (11) provided; a control means (21) for driving and controlling the switching element in accordance with the operation of the horn operating means; charged when the electromagnetic relay is de-energized, discharged when the electromagnetic relay is energized, and A capacitor (24) for supplying power to the control means, a wire (9a) commonly used for energizing the electromagnetic relay and charging the capacitor, and the wire constitutes a spiral cable (9) connecting the vehicle body and the steering wheel. And a battery (BATT) connected to an electromagnetic relay and a capacitor via the wiring, Charging time of capacitor, the automobile horn controller is set to be shorter than the recovery time of the electromagnetic relay.