JPH0641745B2 - Fuel filter device for diesel engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fuel filter device for a diesel engine equipped with a device for discharging water accumulated in a water reservoir of a filter according to the present invention.

(Prior Art) Generally, the fuel oil of a diesel engine is 300 p of free water.
In many cases, it contains pm or more, and the water may cause problems such as rusting of the injection pump and sticking. To prevent this, a fuel filter that separates and removes the water in the fuel oil is used. . Furthermore, it is necessary to discharge the accumulated water as needed, but this method is detected by the driver with an alarm lamp, buzzer, etc. when the water has accumulated to the required drainage level, and after the engine is stopped, the drain cock is opened manually and the water is discharged. is the current situation.

The amount of water contained in the fuel oil varies depending on the region, but when it is large, the filter water reservoir may be filled 3 to 4 times a day, and the driver may not perform sufficient maintenance. Drainage If not drained when necessary, a large amount of water will flow out of the filter and damage subsequent functional parts.

As an example of conventional technology to prevent this, use a float / valve as the drain valve, set the specific gravity so that the float floats in the water and sinks in the fuel, and close the drain opening when it sinks to float. There is a valve that opens the drain opening in a closed state so that the drain can be opened only when water is accumulated, but it is a valve that depends on the ups and downs of the float, and the force does not work when closing it. Therefore, there is a drawback that the reliability against fuel leakage at the time of closing is small. There is also one that uses a level sensor that detects the amount of water pool and a solenoid valve together to output a signal when discharge is required by the level sensor to open the solenoid valve, but a fuel filter is installed on the suction side of the injection pump of the diesel engine. In the installed system, drainage may not occur smoothly even if the solenoid valve is opened to open the drain.

For example, Japanese Utility Model Laid-Open No. 57-198357 discloses a device which detects the water level in a water reservoir and automatically opens a solenoid valve to discharge water. However, in addition to the above-mentioned problems, since the solenoid valve is provided at the lowermost position, the solenoid valve is apt to malfunction due to water accumulated in the water reservoir, and the discharge path extends below the water reservoir. Therefore, if the solenoid valve fails in the open state, the fuel in the fuel filter may be discharged.

Further, as disclosed in Japanese Examined Patent Publication No. 52-7488, there is known a device for discharging water in a water reservoir portion by using a manual pump for teaching assistance, or a user's operation is required.

[Problems to be Solved by the Invention] In view of the above-mentioned problems of the prior art, the present invention is capable of automatically and surely discharging water from the water reservoir of the fuel filter, and is less likely to cause device failure. An object of the present invention is to provide a diesel engine fuel filter device capable of reliably preventing fuel leakage even at times.

[Means for solving problems]

In order to achieve the above object, the present invention provides a diesel engine fuel filter device having a water reservoir provided in a fuel passage on a suction side of a fuel pump of a diesel engine for separating and storing water mixed in fuel, wherein A fuel inlet (1) and a fuel outlet (2) connected to the passage are provided, and a filter element (6) for filtering the fuel flowing from the fuel inlet to the fuel outlet is housed therein, and the bottom part serves as the water reservoir part. The formed case (3) is a passage having one end connected to the bottom part of the case, which is a passage that opens from the bottom part of the case to the outside after passing through the top part of the case, and discharges water accumulated in the water reservoir part. A discharge path (17, 14, 20) to be driven, and an electric pump (1 provided on the discharge path for discharging the water in the previous-stage water reservoir through the discharge path 3) and a solenoid valve (1) provided at the uppermost part of the discharge path and opening and closing the discharge path at the uppermost part.
1) and control means for controlling energization of the electric pump and the solenoid valve according to the level of water in the water reservoir.

[Action]

According to the above configuration of the present invention, the electric pump is automatically driven according to the water level in the water reservoir, the electromagnetic valve is opened, and the water is discharged. Therefore, the electric pump reliably discharges the fuel, and the solenoid valve reliably prevents fuel leakage.

Moreover, the discharge path extending from the bottom of the case is opened to the outside after passing through the top of the case once from the bottom of the case. Therefore, if the solenoid valve is open,
A large amount of fuel in the case is not discharged through the discharge path, and a large amount of fuel leakage does not occur even when the solenoid valve fails in the open state. Further, since the solenoid valve is provided at the uppermost part of the discharge path, water does not collect in the movable portion such as the valve portion of the solenoid valve, and the moving portion corrodes due to the intrusion of water, which causes a failure. It is also prevented.

(Examples) The present invention will be described in detail below with reference to specific examples. First
In the figure, a cap 4 having a fuel inlet 1 and a fuel outlet 2 is fixed to a case 3. Inside the case 3, a perelenmeto 6 and a water separation element 7 are arranged. Below the water separation element 7 is a water reservoir 9. A float type level switch 10 is arranged in the water reservoir 9. This switch 10 includes a magnet 10d
Built-in float 10a and two reed switch parts 10
b and 10c.

A drain portion 17 is provided on the bottom portion 3a of the case 3, and the inlet 15 of the electric pump 13 is connected thereto. The outlet 14 of the electric pump 13 is connected to the inlet 18 of the solenoid valve 11, and the outlet 19 of the solenoid valve 11 is connected to the drain hose 20. The electric pump 13 is attached to the mount 16.
The solenoid valves 11 are mounted on the valve seats 12, respectively, and the mounting base 16 and the valve seats 12 are mounted on the side wall of the case 3. In the figure, reference numeral 5 is a hand pump for drawing fuel oil into the case 3, and 8 is a mesh filter. The fuel filter having the above structure is inserted in the intake side passage of the fuel injection pump of the diesel engine.

FIG. 2 shows an electric circuit diagram in the above embodiment,
Explaining this, in the float switch 10, the upper reed switch portion 10b is a normally open contact type and the lower reed switch portion 10c is a normally closed contact type.

Both reed switch parts 10b and 10c are connected in series to a power supply circuit including a relay coil 21. One relay contact 22 of the relay coil 21 is connected in parallel with the upper reed switch section 10b. On the other hand, the solenoid valve 11 and the electric pump 13 are connected in parallel to each other, and the other relay contact 2 of the relay coil 21 is connected to the solenoid valve 11 and the electric pump 13.
3 is connected. In the figure, reference numeral 24 is an ignition switch (engine key switch), 25 is a fuse, and 26 is a power source.

Next, the operation of the above structure will be described. Fuel oil is first
Flow through the route shown. The water contained in the fuel oil is separated by the water separation filter 7 and falls into the water reservoir 9.

Then, when the water level rises due to the water falling into the water reservoir 9 and the float 10a is positioned on the upper reed switch 10b, the contact of the switch 10b is closed. Therefore, as can be seen from FIG. 2, the relay coil 21 is energized and the relay contacts 22 and 23 are closed. Therefore, by closing the relay contact 23, the electromagnetic valve 11 and the electromagnetic pump 13 are energized, and the water in the water reservoir 9 is discharged to the outside.

On the other hand, when the water level in the water reservoir 9 drops, the reed switch 10b opens, but the relay contact 22 is closed, so the electromagnetic valve 11 and the electric pump 13 continue to be energized. When the water level further drops and the float 10a is positioned on the lower reed switch section 10c, the switch section 10c
Contact opens. As a result, the relay coil 21 is de-energized and the relay circuit is opened, so that the operation of the solenoid valve 11 and the electric pump 13 is stopped.

It should be noted that, as described above, the level at which the lower reed switch section 10c operates can be set to a level slightly higher than the level at which all water is discharged, so that leakage of fuel oil can be prevented.
Further, even if the solenoid valve 11 is still closed by the stick, the solenoid valve 11 is arranged above the case 3, that is, above the fuel oil level inside the filter including the case 3 and the cap 4, so that the fuel No oil leak will occur.

In the above embodiment, the electric pump 13 for forced drainage is used.
The suction side is connected to the bottom 3a of the case 3, but the pressurizing side may be connected to drain the water in the water reservoir 9 so as to push it out.

Further, two lower reed switch parts 10c may be connected in series in order to enhance safety against fuel leakage.

Further, the electric pump 13 and the bottom portion 3a of the case 3 can be connected by a long pipe.

Furthermore, although the float type reed switch is used as the switch configuration for controlling the operation of the electric pump 13 and the solenoid valve 11 in the above-described embodiment, an electrode type using two electrodes that are conducted by the electrical resistance of water may be used. Also, a transistor circuit may be used instead of the electromagnetic relay circuit.

(Effects of the Invention) As described above, according to the present invention, it is possible to forcibly drain the water accumulated in the water reservoir of the fuel filter and to avoid the fuel leakage.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
It is an operation circuit diagram of a solenoid valve and an electric pump in the figure. 9 ... water reservoir, 10a ... float, 10b, 10c ...
Reed switch, 11 solenoid valve, 13 electric pump, 21 relay coil, 22, 23 relay contacts.

Claims (3)

[Claims] 1. A fuel filter device for a diesel engine, comprising a water reservoir provided in a suction-side fuel passage of a fuel pump of a diesel engine, for separating and retaining water mixed in the fuel, and a fuel connected to the fuel passage at an upper portion thereof. A case (3) in which an inlet (1) and a fuel outlet (2) are provided, a filter element (6) for filtering fuel flowing from the fuel inlet to the fuel outlet is housed therein, and a bottom is formed as the water reservoir. ), One end of which is connected to the bottom of the case, and which is a passage that opens from the bottom of the case to the outside after passing through the top of the case, and a discharge path (17, 14, 20), an electric pump (13) provided in the discharge path for discharging the water in the water reservoir via the discharge path, and A solenoid valve (1) provided at the uppermost portion and opening and closing the discharge path at the uppermost portion
1) and a control means for controlling energization of the electric pump and the solenoid valve according to the level of water in the water reservoir, a fuel filter device for a diesel engine. 2. The control means operates the electric pump and opens the solenoid valve when the level of water in the water reservoir rises to a predetermined level. A fuel filter device for a diesel engine according to the item. 3. The control means stops the electric pump and closes the electromagnetic valve when the level of water in the water reservoir falls to a predetermined level. A fuel filter device for a diesel engine according to the item.