JP3155820B2 - Fluid supply control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid supply control device, and more particularly to a fluid supply control device for supplying a predetermined amount of fluid continuously supplied from a tank to a supply target.

[0002]

2. Description of the Related Art For example, there is a device for automatically supplying a predetermined amount of oil as a fluid into a damper at the time of manufacturing an oil damper. FIG. 5 shows a schematic configuration of a hydraulic circuit in such a device. There is something like that.

In FIG. 5, a pump 7 is driven by driving means (not shown), and the pump 7
Oil as a fluid stored in the flow sensor 2
For example, the oil is supplied to an oil damper 9 through an electromagnetic switching valve. Flow sensor 2 and switching valve 4
Is electrically connected to the controller 1 for controlling the apparatus, and the controller 10 includes a counter 3 for integrating a flow signal from the flow sensor 2 and an oil supply start switch SW. Connected.

When the switch SW is in the off state, the switching valve 4 is switched to the tank return side for returning the oil continuously pumped from the pump 7 into the tank 8, but the switch SW is turned on. Then, it switches to the supply target side for supplying oil to the oil damper 9 as the supply target. Then, the flow signal of, for example, a pulse wave from the flow sensor 2 is integrated by the counter 3, and when the integrated flow value reaches a preset value, a count-up signal from the counter 3 is output to the controller 10, and A switching signal is output from the controller 10 to the switching valve 4. In response to the switching signal, the tank 8
The switching valve 4 switches to the side to return to the inside, and the oil damper 9
The oil supply to is terminated.

[0005] Incidentally, the control unit of the hydraulic circuit is shown in FIG.
Is configured as schematically shown in FIG. In FIG.
The signal of the switch SW is input to the clock terminal CLK of the flip-flop FF1 via the inverting circuit NT1 in the controller 10. The flip-flop FF1
Is connected to the inverted output terminal -Q, and the output terminal Q is connected to the base of the driving transistor T1. The collector of the drive transistor T1 is connected to the coil of the drive relay 5 for selectively driving the solenoid SOL of the switching valve 4.

The switch signal of the count-up switch CS of the counter 3 is input to the reset terminal R of the flip-flop FF1 via the inverting circuit NT4. The flow sensor 2 outputs a pulse wave corresponding to the flow, and a flow signal based on the pulse wave is output from the signal gate circuit 1 in the controller 10.
1 input terminal I. The output terminal O of the signal gate circuit 11 is connected to the base of the transistor T2 whose collector is connected to the signal input terminal of the counter 3. The output terminal Q of the flip-flop FF1 is connected to the gate terminal G of the signal gate circuit 11.

The controller 1 constructed as described above
The operation of 0 will be described below. When the switch SW is turned on, the clock terminal CLK of the flip-flop FF1
As the input signal rises, the output of the output terminal Q goes high (H) and the drive transistor T1 is turned on, so that the contact of the drive relay 5 is turned on and the coil SOL of the switching valve 4 is excited. State. Therefore, the switching valve 4 switches from the tank 8 return side to the supply target side,
Oil pumped by the pump 7 can be supplied to the oil damper 9.

The signal gate circuit 11 opens the gate by inputting an H level signal to the gate terminal G in the above oil supply state, and can input a flow detection signal from the flow sensor 2 to the counter 3 via the transistor T2. To Then, the flow detection signal is integrated by the counter 3, and when it reaches the set value, the switch signal of the count-up switch CS is output, and the reset terminal R of the flip-flop FF1 is reset.
Becomes low level (L), the flip-flop FF1
Is reset. Therefore, the output of the output terminal Q of the flip-flop FF1 becomes L level, the switching valve 4 is switched to the tank return side by turning off the drive transistor T1, and the gate of the signal gate circuit 11 is closed. The signal input is cut off.

However, in the above-mentioned circuit, if the flow signal is not output from the flow sensor 2 for some reason, there is a problem that the oil is continuously supplied because the counting is not performed.

[0010]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, a main object of the present invention is to improve the flow sensor in order to prevent the fluid from being continuously supplied to the supply object when the flow sensor fails. The purpose of the present invention is to provide a fluid supply control device for supplying the fluid.

[0011]

According to the present invention, it is an object of the present invention to selectively distribute fluid continuously pumped from a tank to one of a supply target side and a tank return side. A switching valve, a flow sensor for detecting the flow of the fluid, a supply start signal generating means (SW), and a supply amount of the fluid is calculated based on a flow detection signal from the flow sensor. Count up
A counter (3) for generating a stop signal;
Supply start signal from the generating means and the flow by the flow sensor
Is the said switching valve by an input of the two signals of the detection signal
When a switching valve drive signal for switching to the supply target side is generated,
And said count-up signal switching means you switch the switching valve to the tank return-side by the input of the (FF2),
When the flow detection signal is not detected for a predetermined time or more, the switching valve is switched to the tank return side.
Reset means (6) for resetting the switching means , wherein the switching means (FF2) outputs the supply start signal
If the flow detection signal is not input when
This is achieved by providing a fluid supply control device that does not generate the switching valve drive signal .

[0012]

In this way, when the flow detection signal from the flow sensor is not detected by the reset means for a predetermined time or more, the switching valve is switched to the tank return side, and
The means switching the flow detection signal in the event of a supply start signal
Ri because there is possible to switch the switching valve to the supply side of the object if not detected, at the time of the flow sensor failure without a state in which the switching valve has been switched to the supply side of the object, the normal
The flow detection signal can be monitored at the same time to prevent the oil from being continuously supplied at the start of the supply and during the supply.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a preferred embodiment of the present invention.

FIG. 1 is a circuit diagram schematically showing a control unit of a hydraulic control circuit of an oil supply device for an oil damper to which the present invention is applied. This embodiment is applied to the hydraulic circuit shown in FIG. 5 of the above-described conventional example, and corresponds to the control circuit shown in FIG. 6, and the same parts as those described above are denoted by the same reference numerals. And a detailed description thereof will be omitted.

The controller 1 shown in FIG. 1 includes an oil supply start switch SW as a supply start signal generating means , a flow sensor 2, a counter 3, and a drive relay 5 for a switching valve 4, as in the conventional example. Each is connected. In the controller 1, a first flip-flop FF1 which receives a switch signal from a switch SW via a first inverting circuit NT1, and a second flip-flop F serving as switching means connected to the first flip-flop FF1
F2. First flip-flop FF1
Is connected to the D terminal of the second flip-flop FF2, and the output terminal Q of the second flip-flop FF2 is connected to the base of the drive transistor T1 for the drive relay 5. When the drive transistor T1 is turned on, the coil of the drive relay 5 for driving the switching valve 4 is excited as in the conventional example.

The flow signal from the flow sensor 2 is input to the clock terminal CLK of the second flip-flop FF2 via the second inverting circuit NT2 at the preceding stage. Therefore,
When the switch SW is turned on, the second flip-flop FF2 receives the H signal output from the output terminal Q of the first flip-flop FF1, and waits for input to the clock terminal CLK. Then, when a flow detection signal including a pulse wave is input from the flow sensor 2, an H level signal is output from the output terminal Q of the second flip-flop FF2.

The output signal from the inverted output terminal -Q of the second flip-flop FF2 and the output signal from the flow sensor 2 after passing through the preceding and succeeding second and third inverting circuits NT2 and NT3. , A first NOR circuit NOR in parallel with each other
1 is input. The output signal from the first NOR circuit NOR is input to the base of the transistor T2.
2 is used as a flow detection signal for the counter 3
Is input to

The flow signal from the flow sensor 2 is the second
The signal is input to the A input terminal of the multivibrator 6 as reset means via the inverting circuit NT2. An external CR circuit is connected to the T1 and T2 terminals of the multivibrator 6, and the output signal from the inverted output terminal -Q of the multivibrator 6 is output to the fourth inverting circuit N of the counter 3.
Along with the count-up signal after passing through T4, they are input to the second NOR circuit NOR2 in parallel with each other. The output signal of the second NOR circuit NOR2 is input to each of the reset terminals R of the flip-flops FF1 and FF2.

The controller 1 constructed as described above
The operation of each signal (A) to each point at each point shown in FIG.
This is shown below with reference to FIG. 2 showing the time chart of (I). (A) shows the switch signal of the ON / OFF state of the switch SW, (B) shows the oil supply permission signal which is the Q output of the first flip-flop FF1, (C) shows the flow detection signal by the flow sensor 2, D) is a solenoid valve drive signal for switching the switching valve 4 to the load supply side, (E) is a flow detection enable signal of the flow detection signal, (F) is a flow detection capture signal captured by the counter 3, (G) Is the count-up signal from the counter 3, and (H) is both flip-flops F
(I) shows a reset signal for F1 and FF2, and (I) shows an abnormality detection signal of the flow detection signal.

In the initial state, the pump 7 having the same configuration as that of FIG. 5 is rotated to continuously pump oil, but the switching valve 4 is selected to return to the tank and the pump is fed. The oil has been returned to the tank 8. In this state, the flow of the oil is detected by the flow sensor 2. However, since the switch SW is off, the oil supply permission signal (B) is at the L level, and the flow detection permission signal (E) is output. Since the flow detection signal is at the H level, the flow detection capture signal (F) remains at the L level regardless of a change in the flow detection signal (C), and the flow detection signal is not input to the counter 3.

Next, when the switch SW is turned on to supply oil to the oil damper 9, its rise is detected and the oil supply permission signal (B) becomes H level, and the clock of the second flip-flop FF2 is clocked. Terminal CLK
By detecting the rise of the flow detection signal (C) by the switching
The solenoid valve drive signal (D) as the replacement valve drive signal becomes H level, the solenoid SOL of the switching valve 4 is excited, and the switching valve 4 is switched to the supply target side. As described above, the switching condition of the switching valve 4 is set by combining the two flip-flops FF1 and FF2, that is, when the flow detection signal (C) is not detected when the oil supply permission signal (B) is generated. A circuit that inhibits the operation of switching the switching valve 4 on the supply target side is configured.

At the same time as the switching valve 4 is switched to the supply target side, the flow detection permission signal (E) becomes L level, and the flow detection capture signal (F) is output to the counter 3. Then, as shown in the second stage from the bottom of the time chart of FIG. 2, the supply amount calculated in the counter 3 based on the flow detection capture signal (F) which is equivalent to the flow detection signal (C). Is increased.

The inverted output of the multivibrator 6
The abnormality detection signal (I) which is Q outputs an L level signal of a predetermined width triggered by a rising edge of the flow detection signal (C) to the input terminal A. This width can be adjusted by an external CR circuit. If the pulse width is set longer than the pulse width of the flow signal in the normal state, the L level signal is always output in the normal state as shown in the second stage from the top in FIG. Therefore, if the flow detection signal (C) remains at L level due to abnormality, the inverted output -Q of the multivibrator 6 becomes H level after the set time by the CR circuit. The combination of the multivibrators 6 constitutes a circuit for switching the switching valve 4 to the tank return side when the flow detection signal (C) is not detected for a predetermined time or more.

When the integrated value reaches a predetermined set value N while the oil is continuously supplied, the count-up switch CS in the counter 3 is turned on, and the count-up signal (G) goes to the L level. In the normal state, the abnormality detection signal (I) is at the L level, and the reset signal (H) goes to the H level in response to the change of the count-up signal (G) to the L level.
1 · FF2 is reset, the output of the flow detection capture signal (F) to the counter 3 is not performed, and the switching valve 4 is switched to the return side so that the oil damper 9 is reset.
Supply of oil to the pump is stopped.

FIG. 3 is a time chart corresponding to FIG. 2 in a case where the flow sensor 2 is out of order for some reason and fails to output a pulse wave, and is in an abnormal state in which the flow sensor 2 is always at the L level. It is shown below with reference.

If the above-mentioned abnormality has occurred before the start of oil supply, even if the switch SW is turned on and the switch signal (A) becomes H level, the flow detection signal (C) becomes L level.
Since the level remains, the reset signal (H) becomes H level due to the H level of the abnormality detection signal (I), and both flip-flops FF1 and FF2 are in the reset state. Therefore, as shown in the first half of FIG. 3, the solenoid valve drive signal (D) remains at the L level, and oil is not supplied to the oil damper 9 in the event of an abnormality.

Next, as shown in the middle part of FIG.
When the flow sensor 2 is normal, when the switch SW is turned on and the switch signal (A) becomes H level, the integrated value in the counter 3 starts to increase as described above. Then, as shown in the second half of FIG. 3, when the flow sensor 2 fails during the counting and the pulse wave is not input, the counting is interrupted before reaching the set value N in the counter 3. Therefore, the L level signal of the count-up signal (G) is not output from the counter 3.

However, after an elapse of a predetermined time T, an abnormality is detected by the multivibrator 6 and the abnormality detection signal (I) becomes H level, so that the reset signal (H) becomes H level.
Level, and the solenoid valve drive signal (D) from the second flip-flop FF2 becomes L level. Then, the solenoid SOL of the switching valve 4 is de-energized, and the switching valve 4 is switched to the tank return side, so that oil is not supplied to the oil damper 9. Therefore, it is possible to prevent the oil supply to the oil damper 9 from being continued without counting up due to the failure of the flow sensor 2.

As described above, according to the present embodiment, the flow detection signal is constantly monitored, and if the flow detection signal is no longer input due to the failure of the flow sensor or the disconnection of the harness, the switching valve 4 is returned to the tank. As a result, it is possible to prevent the oil from being unnecessarily supplied to the oil damper 9.

FIG. 4 shows a second embodiment according to the present invention. In the second embodiment, the same parts as those in the above embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the second embodiment, the case where the multivibrator of the first embodiment is not used is shown, and the flow detection signal (C) via the second inverting circuit NOT2 is shown.
Are the clock terminal of the second flip-flop FF2 and the third
The count-up signal from the counter 3 is input to the reset terminals R of the flip-flops FF1 and FF2 only through the fourth inverter NT4. Also in this case, when the rising edge of the flow detection signal (C) is input to the clock terminal CLK of the second flip-flop FF2, the inverted output terminal -Q of the second flip-flop FF2 becomes L level, A signal corresponding to the change in the flow detection signal (C) is output from the first NOR circuit NOR1 to the transistor T2.

As described above, when the flow detection signal is not input due to the failure of the flow sensor or the disconnection of the harness, the solenoid valve drive signal (D) from the second flip-flop FF2 remains at the L level. Since the solenoid SOL of the switching valve 4 is not excited and the switching valve 4 is held on the tank return side, no oil is supplied to the oil damper 9. Therefore, when the switch SW is turned on,
If the flow detection signal (C) is not input due to some abnormality, the solenoid SOL of the switching valve 4 does not become excited and the switching valve 4 does not switch to the supply target side.
Inconvenience that oil is supplied to the oil damper 9 at the time of abnormality can be prevented.

[0033]

As described above, according to the present invention, the flow detection is always performed.
If a flow detection signal is not input due to a failure of the flow sensor or the like, the switching valve is returned to the tank side when the detection signal is not detected for a predetermined time during supply, and the supply signal is monitored. If the detection signal is not detected at the start, the switching valve is not switched to the supply target side from the beginning, so even if the supply permission signal is generated, the supply switching valve does not switch to the supply target side, and the flow is not changed. It is possible to prevent the inconvenience of continuously supplying the fluid to the supply target without being able to calculate the supply amount due to a sensor failure or the like.

[Brief description of the drawings]

FIG. 1 is a circuit diagram schematically showing a control unit of a hydraulic control circuit of an oil supply device for an oil damper to which the present invention is applied.

FIG. 2 is a diagram showing a time chart in a normal state in control according to the present invention.

FIG. 3 is a diagram showing a time chart at the time of abnormality in control according to the present invention.

FIG. 4 is a view showing a second embodiment and corresponding to FIG. 1;

FIG. 5 is a diagram schematically showing a hydraulic circuit of a hydraulic control circuit of an oil supply device for an oil damper according to a conventional example.

FIG. 6 is a circuit diagram schematically showing a control unit of a conventional hydraulic control circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Controller 2 Flow sensor 3 Counter 4 Switching valve 5 Drive relay 6 Multivibrator 7 Pump 8 Tank 9 Oil damper 10 Controller 11 Signal gate circuit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B67D 5/00 F17D 3/00

Claims (1)

(57) [Claims] And 1. A supply side of the object fluid is continuously pumped from the tank and the tank return side switching valve for distributing selectively to one of a flow sensor for detecting the flow of the fluid, supply A supply amount of the fluid is calculated based on a start signal generating means (SW) and a flow detection signal from the flow sensor, and counting is performed when the supply amount reaches a predetermined value.
A counter (3) for generating an up signal;
The supply start signal from the signal generation means and the flow sensor
The switching valve is activated by the input of both signals
Generates a switching valve drive signal for switching to the supply target side
Means switching Switching between the switching valve to the tank return-side by the input of the count-up signal with (FF2)
When the reset means and said flow detection signal when it is no longer detected for a predetermined time for resetting said switching means to switch said switching valve to the tank return side (6)
And the switching means (FF2) receives the supply start signal.
Sometimes, when the flow detection signal is not input,
A fluid supply control device that does not generate a valve drive signal .