JPS62101513A - Electronic control suspension - Google Patents

Abstract

PURPOSE:To protect the contact of a compressor relay by arranging the constitution in such a way that the stoppage of a compressor relay may be delayed by a specified time when a pressure switch in a reserve tank is changed from ON to OFF, in the above-mentioned suspension device provided with adjustment function for car floor height. CONSTITUTION:When a pressure switch 5 is turned OFF by a car floor height adjustment signal (a) and chattering occurs, a timer circuit T1 is triggered and turned ON for a specified time. And the signal of a pressure switch 5 is input into OR circuit OR1, but since the output from a timer circuit T1 is ON, the output of OR1 keeps an ON condition. Consequently, a compressor relay 17 performs a usual operation and stops operation after a specified time. Therefore, there is never such a case where a starting current flows whenever the pressure switch 5 is closed or opened for a short time in the driving circuit of a compressor 1 and it is possible to contrive to protect a relay contact.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronically controlled suspension having a vehicle height adjustment function.

[Conventional technology]

The fourth figure is a diagram showing 14 configurations of a conventional electronically controlled suspension. In the figure, 1 is an electric compressor that generates compressed air, 2 is an air filter installed on the intake side of this compressor l, 3 is an exhaust solenoid provided on the exhaust side, and 4 is an electric compressor that stores compressed air. A reserve tank 5 is attached to this reserve tank 4, and a pressure switch 6 for detecting the pressure inside the tank is disposed on the compressed air suction side of the reserve tank 4.
A dryer for drying the compressed air from 7, an air supply solenoid pulp attached to the reserve tank 4, 8, 9
are a front solenoid pulp and a rear solenoid pulp, to which are respectively connected a front suspension unit 1o and a rear suspension unit 11 whose vehicle height is changed by compressed air.
Reference numerals 12 and 13 designate a front wheel and a rear wheel, respectively, and 14 and 15 designate a vehicle height sensor for detecting the front vehicle height and a vehicle height sensor for detecting the rear vehicle height. Furthermore, 16 is piping connecting the compressor l and the reserve tank 4, the reserve tank 4 and the front and rear solenoids 8 and 9, each solenoid 8.9 and the front and rear suspension units 10 and 11, etc.
17 is a compressor relay for driving the compressor 1; 18 is a control unit that operates the compressor relay 17 and each solenoid pulp 3, 7, 8.9 according to the signal from the vehicle height sensor 14.15 and the signal from the pressure switch 5; 19 is a key switch for turning on and off, and 20 is a power supply device for driving each of the above components.

FIG. 5 is a circuit diagram showing the connection between the control unit 18 and the compressor relay 17, etc. In the figure, 18a is a compressor relay differential circuit, and Ro is a resistance inside the control unit 18 for taking out the signal of the pressure switch 5. .

Next, the operation will be explained. The compressor l takes in atmospheric air through the air cleaner 2, compresses it, and supplies it to the dryer 6. The compressed air dried by the silica glue etc. of the dryer 6 is supplied to the suspension units 10 and 11 as indicated by solid line arrows in FIG. Furthermore, when the compressed air is discharged from the suspension unit 10.11, it is discharged to the atmosphere through the exhaust solenoid pulp 3 as shown by each broken line arrow. Furthermore, since the reserve tank 4 is connected to the dryer 6, a portion of the compressed air is sent from this reserve tank 4 to each suspension 22 via the air supply solenoid pulp 7 and the front and rear solenoid pulses 7''8 and 9e. ) 10.degree. 11.Front and rear vehicle height detection signals are supplied to the control unit 18 from vehicle height sensors 14 and 15, respectively.

These vehicle height sensors 14 and 15 have one of the Hall IC elements and magnets on the wheel 12. The distance from each level is detected.

It should be noted that the vehicle height sensor may have other configurations, such as one using a phototransistor.

Furthermore, the compressed air in the reserve tank 4 changes each time it is supplied to the suspension unit 1O211 during vehicle height control, and the pressure switch 5 detects this change. Here, for example, if the pressure is below the set value, the pressure switch 5 supplies an ON signal to the control unit 18, and the control unit 18 operates the compressor relay 17, which drives the compressor l, and the reserve via the dryer 6. Supply compressed air to tank 4. When the pressure in the reserve tank 4 rises and reaches the set pressure, the contact point of the pressure switch 5 changes from on to off, and this off signal causes the compressor relay 17 to be inactivated via the control unit 18. l stops.

[Problem that the invention seeks to solve]

Since the conventional electronically controlled suspension is configured as described above, the compressor 1 must be operated via the compressor relay 17 in response to the operation of the pressure switch 5. Therefore, if the pressure switch 5 chattering (instantly turns on and off several times) or if a stop signal is input immediately after starting the compressor 1 during vehicle height control, the large current generated when the compressor 1 starts will be transferred to the compressor. Relay 17 will be cut off. This is shown in FIG. 6. When the signal waveform at point a, that is, the signal from pressure switch 5, turns on and off, the output signal of compressor relay drive circuit 18a (signal at point b) turns on and off accordingly. Therefore, the starting current flows each time the current (0 point) to the compressor I flows. Therefore, when this is interrupted, arcing occurs between the contacts of the compressor relay 17, and if this is repeated many times, there are problems such as significantly shortening the life of the contacts and causing welding of the contacts.

This invention was made to solve the above-mentioned problems, and its purpose is to provide an electronically controlled suspension that can reliably protect the contacts of a compressor relay.

[Means for solving problems]

The electronically controlled suspension according to the present invention includes a pressure switch that detects the pressure in the reserve tank, and a compressor relay IJK operation based on the signal of the pressure switch.
The compressor is equipped with a compressor that is energized and controlled by a compressor relay, and a delay means that stops the compressor relay after a predetermined time delay when the pressure switch changes from on to off.

[Effect]

In this invention, since the delay means is provided,
Even if the pressure switch chattering or a stop signal is input to the control unit immediately after the compressor starts, the compressor relay will stop after a predetermined period of time, and the drive will not respond to the stop immediately after the compressor starts or the pressure switch is turned on and off for a short time. Not done.

〔Example〕

FIG. 1 is a circuit diagram showing a narrow portion of an electronically controlled suspension according to an embodiment of the present invention. In the figure, 21 is a control unit, R is a resistor whose one end is connected to the power supply 20 and the other end is connected to the pressure switch 5 to detect the contact signal of the pressure switch 5, and R is a resistor whose one end is connected to the power supply 20. , the other end is a resistor connected to the timer circuit Tt, C2 is a capacitor, OR1 is an OR circuit which inputs the output signal of the timer circuit T+ and the signal from the pressure switch 5 and performs OR logic.
Compressor relay drive 00 path 21 a to its output terminal
is connected. Further, the timer circuit T is triggered by the fall of the output signal of the pressure switch 5 from on to off, and is configured to be on for a predetermined time determined by C3 and C3. Note that 1.17 is a compressor and a compressor relay as in FIG.

Next, the operation of the electronically controlled suspension configured as described above will be explained using FIG. 2. When normal vehicle height control is being performed and one pressure switch 5 is turned off and chattering occurs as shown in the signal at point a, timer circuit T
t is triggered and turned on for a predetermined time as shown by the signal at point b. And the signal from pressure switch 5 is an OR circuit
However, since the output from the timer circuit TI is on, the output of the OR circuit OR remains on (signal at point e). This is the best way to go
7 performs normal operation as shown by the current at point d, and the compressor relay 17 becomes inactive after a predetermined time. Therefore, no starting current flows through the drive circuit of the compressor 1 every time the pressure switch 5 is opened or closed for a short time.

Next, the operation when the control unit 21t'' software is configured will be explained using the flowchart shown in FIG. 5 is on or off. If the pressure switch 5 is on, the result is YES and the process proceeds to step S3. Then, in step S3, the on flag of the pressure switch 5 is set.

When the pressure switch 50 ON flag is set, the process proceeds to step S4, and in this step S4, the compressor relay 17 is activated and the process returns.

10,000, if it is determined in step S2 that the pressure switch 5 is off, the answer is NO9, and the process proceeds to step S5, where the pressure switch 5 is determined to be off.
Determine whether the on flag is set. If the ON flag of the pressure switch 5 is set, the answer is YES and the process proceeds to step S6, and after waiting for a predetermined time, the process proceeds to step S7. When the process proceeds to step S7, the ON flag of the pressure switch 5 is cleared, and the process proceeds to step S8, where the compressor relay 17 is deactivated and the process returns. If the process waits for a predetermined time in step S6, the answer is NO, and the process returns to step S6. Furthermore, if the ON flag of the pressure switch 5 is not set in step S5, the answer is NO9, and the process proceeds to step S8, where the compressor relay 17t is deactivated and the process returns.

〔Effect of the invention〕

As described above, according to the present invention, since the compressor relay drive circuit is provided with a delay means for delaying the off signal from the pressure switch for a predetermined period of time, the compressor does not stop immediately after starting, and therefore the compressor relay contacts Since there is no large current interruption and only the normal current is interrupted, the life of the contact is extended and the occurrence of welding etc. can be prevented.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing the main parts of an electronically controlled suspension according to an embodiment of the present invention, Fig. 2 is a time chart showing the operation of each part in Fig. 1, and Fig. 3 is the operating order of the electronically controlled suspension. FIG. 4 is a flowchart showing the overall configuration of a conventional electronically controlled suspension.
This figure shows a conventional compressor relay drive circuit, and FIG. 6 is a time chart showing the operation of each part in FIG. 5. 1... Compressor, 4... Reserve tank, 5...
...Pressure switch, io, tt...Suspension unit, 12.13...Wheel, 17...Compressor relay, 20...[Power supply fill, 21...Control 22], 21a... ...Compressor relay drive circuit, T□...Timer circuit. In addition, the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] A hydraulic suspension unit that is interposed between the wheels and the vehicle body of a vehicle and has a fluid chamber for adjusting vehicle height, a reserve tank that stores fluid to be supplied to the fluid chamber, and a pressure that detects the pressure in the reserve tank. a switch, a compressor that pressure-feeds fluid to the reserve tank, a compressor relay that is installed between the compressor and the power supply device and turns on/off the energization, a control unit that drives and controls the compressor relay based on a signal from the pressure switch; An electronically controlled suspension comprising a delay means for stopping the compressor relay after a predetermined delay when the signal from the pressure switch changes from on to off.