JPS61135806A - Vehicle height adjusting apparatus - Google Patents

Abstract

PURPOSE:To prevent the malfunction and runaway of a car height adjusting apparatus having a digital control means, according to a method wherein a power source is turned off with a delay time after an ignition switch is turned off, and car height control is stopped after the output voltage of a constant voltage generating means decreases. CONSTITUTION:When Ig and Sw are turned off, a transistor T2 is driven only through R4, and then VIN of a micro computer 30 becomes low. Therefore, the destruction timer in the micro computer 30 is operated, VOUT being turned off after a predetermined times, T1 and T2 being turned off, electric supply to a constant voltage Vcc being stopped. The voltage Vcc is monitored through R8 by means of a comparator CMP, the signal at the RES terminal of the micro computer 30 being decreased to low level through R7 when the voltage Vcc is lower than the Zener voltage Vz of Z1. According to the above constitution, the micro computer 30 is certainly turned off after the transistors T1 and T2 are turned off, so that malfunction and runaway can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a vehicle height adjustment device, and more particularly to a vehicle height adjustment device equipped with a digital control device.

[The burden of invention]

Conventionally, the vehicle height adjustment device has been installed on the ignition switch (hereinafter referred to as I).
Abbreviated as g and Sw. ) The adjustment operation was performed only while the t-on was on, but considering the need for people to get on and off, loading and unloading cargo, etc., the 114 adjustment operation should remain for a certain period even after Ig and 3W are turned off. Since it is more convenient, a device with a built-in delay circuit is used, for example, as disclosed in Japanese Patent Application Laid-Open No. 1983. No. 99809. As mentioned above, the function of automatically cutting off the power after Ig and 3W are turned off is called a self-destruction function.

On the other hand, the adjustment device uses a logic IC to accommodate higher functionality.
, microcomputers (hereinafter abbreviated as microcomputers), etc. are increasingly being used. However, by using the above self-destruct function, the above digital equipment was allowed to continue operating for a certain period of time after the Ig and SW were turned off, and then the radio waves were turned off (
In other words, when the power supply to the circuit is cut off, the applied voltage decreases with a time constant that incorporates the power supply voltage, so it passes through a voltage that is not guaranteed by the IC itself, that is, an uncertain region 9, and the above device fogs up. There is a very small chance that it will run or become incapable of self-destruction. In the vehicle height adjustment control device, if a malfunction occurs as described above, the compressor motor will overheat and burn out.
Or, because the Ig was turned off after 8W, the battery died, which was a serious problem for the car. This self-destruction function differs from the OFF timers of other household electrical appliances in that the timer circuit itself has to shut itself down in order to prevent the battery from dying due to the power consumption of the control device.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above-mentioned shortcomings in the prior art, it is an object of the present invention to provide a digital vehicle height control device that can reliably self-destruct without causing foggy driving due to malfunction of the control device. That's true.

[Summary of the invention]

A feature of the present invention is that, in a vehicle height adjustment device having a digital control section composed of a microcomputer, an IC, etc., the output voltage of a constant voltage circuit is detected, and the detected value constitutes the control section of the vehicle height adjustment device. A low voltage detection means is provided that stops the function when the minimum guaranteed operating voltage that guarantees normal operation of the microcomputer or IC is reached.

As a second feature of the present invention, the above object is achieved by providing an integrating circuit in place of the low voltage detection means.

Examples of the invention] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the first invention, in which a vehicle height sensor 10 detects a change in vehicle height and sends a vehicle height detection signal S1 via an input boat 15 to the vehicle height sensor 10. It is output to the microcomputer 30 which is a control means. The microcomputer that receives the vehicle height detection signal Ss performs predetermined arithmetic processing, and then outputs the signal via the input port 15 to the drive circuit 20 that adjusts the vehicle height, thereby adjusting the vehicle height.

On the other hand, the microcomputer 30 receives the power supply voltage VB from the power supply control means 5.
0, is supplied to the Mac terminal of the microcomputer 30 (7) through the constant voltage conversion means 40 and the low voltage detection circuit 60i. This power supply control means 50 is composed of two transistors T1 and T2 and five resistors R1 to R5. Immediately-b,
A power supply voltage 3 is connected to the emitter of the PNP transistor T1, and a resistor R1 is connected between the emitter and base. The base of this transistor T1 is connected to the collector of the NPN transistor T2 via a resistor Rzf. The emitter of the transistor T2 is grounded, the base thereof is grounded via the resistor R3, and
It is connected to the output end of an ignition switch Ig8W, which will be described later, via a resistor R6. Also, both ends of the resistor R6 are connected to the microcomputer 3 through the resistors R4 and R6, respectively.
0's VOUT and vTN terminals.

The collector of the transistor T1, which is the output of the power supply control circuit 50, is input to the constant voltage conversion means 40, and its input terminal is connected to the capacitor C! connected via. The output terminal of this constant voltage conversion output stage 40 is input to a low voltage detection circuit 60, which will be described next, and is grounded via a capacitor C1.

This low voltage detection circuit 60 is composed of a comparator CMP. The output of the power supply control circuit 50 is connected to the power supply terminal of the comparator CMP, and the output is connected to the resistor 9
and Zener diode z1 are directly connected to each other and input to the negative (-) terminal. The output of the constant voltage conversion means 40 is connected to the plus (+) of the comparator CMP via the resistor R8.
+) terminal. The output of the comparator CMP is connected to the RE'3 terminal of the microcomputer 30 through the resistor R+71&:. This terminal is grounded via a capacitor Cs, and is also connected to the Vcc terminal of the microcomputer 30 via a resistor tot''.

The operation of the above embodiment will be explained below. In this circuit, the microcomputer 30 takes in the output of the vehicle height increaser 10 related to vehicle height adjustment, performs arithmetic processing, and outputs the output to the drive circuit 20 via the input/output port 15. Ig, S.W.
When it is turned on, Tzt- is turned on through Rst'', and similarly, Tt' is turned on through R2.

As a result, the battery power supply Vm passes through TtL and the constant voltage circuit 40'i-, and starts supplying a constant voltage to the Vcc terminal. Capacitors Cs and Cm are for smoothing and prevention of oscillation. Note that the control microphone 30 is R1o; Cs
When the power is turned on, the device is reset and starts operating. On the other hand, Ig, 8w, on signal is via R18t-, VIN
The signal is taken into the microcomputer 30 as a signal, and the microcomputer 30 outputs a HIGH signal from VoυT. This will turn on Tz' through R4t, so Ig, 8w.

This means that Tzt" is turned on from two systems, L and V o a τ. Normally, vehicle height control is performed in this state.

Next, we can see the operation when Ig, 8W, is turned off, but Rst
-T via! Drive is impossible 9, 几4 from Voat
T2 drive will be performed only via the route.

On the other hand, Ig, 8w, off signal is via s't'', vI
Also set N to LOW level. Then, a self-destruct timer starts operating inside the microcontroller 30, and after a certain period of time, the Votr
Turn off at t', turn off T2 and Tt, constant voltage ■c
Stop supplying to c. However, since CIICL is charged with electric charge, Vcc does not decrease sharply, but decreases with a time constant as shown in FIG. If left as is, self-destruction will be incomplete due to runaway of the microcontroller 30 in the uncertain region, incorrect port settings of the microcontroller 30, etc. Therefore, the voltage of Vcc is always monitored through the comparator CMP through the terminals υ and Ra, and when the Zener voltage Vz of Zl is lowered, the voltage is dropped to the RE8 terminal 'kLOW of the microcontroller 30 through the γ. However, Vzk
It is set equal to the minimum guaranteed operating voltage of the microcontroller 30. With the above protection, the p microcontroller 30 has Tz H
After Tt is turned off, it is definitely turned off.

According to this embodiment, the low voltage detection circuit 60 can be used as it is as a low voltage reset circuit, and the effect as a protection against a drop in battery power can be obtained.

Next, another embodiment of the above invention will be described using the third figure sound. In the figures, the same reference numbers or symbols as in FIG. 1 represent the same elements. A feature of this other embodiment is that a prohibition circuit 70 is further provided, and the output terminal of the comparator CMP of the low voltage detection circuit 60 is inputted to this prohibition circuit 70 through a resistor. This prohibition circuit 70
Further, the base input of the transistor T2 of the power supply control means 50 is inputted through the resistor R4t-.

The operation of the embodiment described above is almost the same as that of FIG. In the case of this embodiment, a digital device is used as the vehicle height control means 30, and it is effective when there is no reset terminal. When the constant voltage VCC reaches the minimum guaranteed operating voltage or lower, it cannot be reset, so the vehicle height vI4! It is not possible to completely stop the i-device. Therefore, as in this embodiment, the comparator CMP
The output is connected to an inhibit circuit 70 provided between the output terminal Vucrt and the power supply control means 50. This prohibition circuit 70 prevents the re-output of the HOLD signal from the output terminal V otrt from being transmitted to the power supply control means 50 by the signal from the comparator CMF when the constant voltage Vcc reaches the Zener voltage Vz or less. . Second, the vehicle height control means 3 is composed of digital equipment.
Even if the vehicle height adjustment device malfunctions in the uncertain region (below six V cc), the output of the output terminal Votr is not transmitted to the power supply control means 50, so that the vehicle height adjustment device can completely stop its operation.

Further, the object of the present invention can also be achieved by the following configuration.

That is, by combining the power supply control means 50 and the integrating circuit 80 which constitute a constant voltage circuit), the power supply control means 50 is provided with a delay function. The basic configuration diagram is shown in Figure 4. As shown in the figure, the power supply controller R50 and the vehicle height adjustment means I
The integration circuit 80t is provided between the C30 and the integrator circuit 80t. Specifically, as shown in Figure 6(a), the power supply controller R50
The above-mentioned second inventions can be achieved.

The operation according to the second invention above, i.e. the delayed state '1V
The cc waveform is shown in Figure 5. First, Ig, 8w.

After a certain period of time has passed after turning off, the self-destruction operation ends and HO
LD signal turns off. However, when the constant voltage circuit is turned off via the integrating circuit 80, the rounding is delayed as shown in FIG. Next KIg, SW.

Even when it is turned on, it is turned on with a delay due to the integration circuit 80.

According to this method, after the self-destruction ends, the constant voltage circuit turns off and V
Even if ca decreases to below -, vcc and the vehicle height adjustment IC malfunctions and the HOLD signal turns on, the mote circuit will not turn on until after a certain delay time according to TI, so Vca will not turn on during that time. , and the entire system goes down. In this way, reliable self-destruction can be achieved by integrating the self-destruction input signal.

[Effects of the Invention] According to the present invention, it is possible to easily provide a self-destruct circuit that does not malfunction as described above.

[Brief explanation of the drawing]

Figure 1 shows the vehicle height v according to the present invention! Figure 2 is a block diagram showing the vehicle height adjustment device shown in Figure 1.
3 is a block diagram showing another embodiment, FIG. 4 is a block diagram showing a vehicle height adjustment device according to another invention, and FIG. 5 is a diagram showing the embodiment shown in FIG. 4. FIG. 6 is a waveform diagram for explaining the operation, and FIG. 6 is a circuit diagram showing a specific circuit configuration of FIG. 4. 10...Vehicle height, 20...Drive circuit, 30...
- Microcomputer, 40... Constant voltage conversion means, 50... Power supply control means, 60... Low voltage detection circuit, 70... Inhibition circuit, 80... Integrating circuit.

Claims (1)

[Claims] 1. A vehicle height sensor that detects the vehicle height of a vehicle; a vehicle height control means that outputs a vehicle height adjustment signal in response to a signal from the vehicle height sensor; A vehicle height adjustment driving means for correspondingly adjusting the vehicle height of the vehicle; a constant voltage converting means for converting a power supply voltage into a constant voltage and supplying the constant voltage to the vehicle height control means; and an on/off switch for an ignition switch. In a vehicle height adjustment device comprising a power supply control means that turns on and off the supply of power supply voltage in conjunction with a means for turning off the power supply to the power supply control means; and a means for stopping the function of the vehicle height control means when the output voltage of the constant voltage generation means drops below a predetermined reference value after the power supply is turned off. A vehicle height adjustment device characterized by having low voltage detection means. 2. The vehicle height adjustment device according to claim 1, further comprising means for locking the output of the vehicle height control means when the low voltage detection means stops the function of the vehicle height control means. Vehicle height adjustment device. 3. a vehicle height sensor that detects the vehicle height of the vehicle; a vehicle height control means that outputs a vehicle height adjustment signal in response to a signal from the vehicle height sensor; and a vehicle height control means that outputs a vehicle height adjustment signal in response to the vehicle height adjustment signal; a vehicle height adjustment driving means for adjusting the vehicle height; a constant voltage converting means for converting a power supply voltage into a constant voltage and supplying the same to the vehicle height control means; - In a vehicle height adjustment device comprising a power supply control means that turns off, the power supply to the power supply control means is switched off by a power supply stop signal output from the vehicle height control means after a predetermined period of time has elapsed after the ignition switch is turned off. A vehicle height adjustment device characterized in that, when the vehicle height control device is turned off, a power supply stop signal that is an output of the vehicle height control device is taken into the power supply control device via an integrating circuit.