JPS6212388B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for separating water in fuel for an internal combustion engine.

When moisture is mixed into the fuel supplied to an internal combustion engine, rust may occur in the fuel passage, combustion chamber, or fuel tank. Particularly in the case of diesel engines, when moisture is sucked into the fuel injection pump along with fuel, the high-speed moving parts within the pump seize up, leading to poor fuel supply and engine stall, as well as damage to the pump. I can't escape it.

Therefore, in the past, a water separation tank was provided in the fuel passage, for example, in the fuel passage upstream of the fuel injection pump in a diesel engine, to separate the fuel and water into two upper and lower tanks based on the difference in specific gravity, and a predetermined amount of moisture was collected in the water separation tank. At that stage, the water level was detected, an alarm was issued, and the water in the water separation tank was drained (Nissan Motor Co., Ltd.: Showa
Service Bulletin No. 418 “Datsutosan Bluebird” published in April 1955, p. 60). Such conventional water separation devices detect the water level by installing a thermistor in the water separation tank, whose resistance value changes depending on whether it is in the fuel oil or in the water. Another conventional example is shown in FIG.

In FIG. 1, a float 2 equipped with a fixed magnet 1 is provided in a water separation tank, and the float 2 is pivotally supported on a vertically extending guide member 3 so as to be slidable up and down. The guide body 3 has a built-in reed switch 4, and as the water level in the water separation tank (not shown) rises, the float 2
When the fixed magnet 1 moves upward and reaches almost the same level as the reed switch 4, the reed switch 4 is closed by the magnetic force of the fixed magnet 1, and a warning lamp (not shown) is turned on. Ta. At this time, the warning lamp may be turned on and the fuel supply to the injection pump or engine may be cut off at the same time, but if this is configured, the engine will suddenly stop and the driver may be surprised. This is dangerous due to the shock of the engine, or the sudden stop of the engine may cause a rear-end collision with a following vehicle, leading to an accident. Therefore, when the warning lamp lights up as described above, the driver of the vehicle pulls the vehicle to one side and drains the water in the water separation tank as soon as possible.

However, for example, with a distribution type fuel injection pump, as much as 60 fuel flows per hour even in an engine with a total displacement of about 200 c.c., whereas in a water separation tank, at most 1
Therefore, after the water level detection value detects a predetermined water level and lights up the alarm lamp, there is a high possibility that the water separation tank will immediately become full of water and overflow and be introduced into the fuel injection pump. This is because a large amount of water may enter the fuel tank and be sucked in at a certain instant.

Also, Utility Model No. 56-173661 (Utility Application No. 55-71186)
(No.) has two low and high water level sensors that detect low and high water levels.
There is a known water level detector that has several water level detection means, a warning light turns on only when the water level reaches a predetermined low water level, and when the water level reaches a predetermined high water level, the fuel supply is automatically stopped using a fuel cut solenoid. There is.

However, in this case, no special alarm is issued to notify that the predetermined high water level has been reached, so there is no direct connection between the engine stop and the fact that the water in the water separation tank has risen to a high level. It turns out. In other words, the lighting of the warning light simply indicates that the water level is above a low level, and the engine stoppage may be due to clutch malfunction, air-fuel ratio control malfunction, or ignition system malfunction, or other reasons that a person skilled in the art may think of. This is because it simply includes the possibility that the water level in the water separation tank rose to a high level and caused the engine to stop.

For this reason, when the engine stops, it is necessary to investigate and eliminate all possible causes of the engine stopping, and even if the engine stops due to other reasons, the If the water level is at a high level, it is impossible to eliminate the cause of the engine stopping even if the water is drained. On the contrary, in this case, it is mistakenly assumed that water has accumulated to a high level, so there is a risk that not only water but also fuel will be discharged.

In addition, Utility Model No. 55767 (1983)
No. 137373) is equipped with one water level sensor, and when the sensor detects that the water level exceeds a predetermined value, a warning is issued by flashing a lamp, and the stored water is automatically discharged. It is being

However, even when the extractor is running, the fuel supply to the engine continues, so
A problem arises in that the supply of moisture to the engine cannot be completely blocked due to the relationship between the rate of increase in moisture storage and the amount of moisture discharged.

In view of the above-mentioned disadvantages of conventional fuel/water separation devices, the present invention provides a low level sensor and a high level sensor for detecting two high and low water levels, respectively, in a water separation tank, and the low level sensor detects a predetermined water level. If water is detected, an alarm is issued first, and at this stage the alarm is issued to remove the water in the water separation tank as soon as possible. If a high water level is detected, a warning will be issued that is different from a low water level, and the fuel shutoff device will be activated to shut off the fuel passage and prevent fuel from entering the fuel injection pump or engine. It is configured to do so. Furthermore, among the two level sensors,
When at least one of them detects a predetermined water level, a water draining device is attached to drain the water in the water separation tank, thereby ensuring that the water in the water separation tank is never supplied to the fuel injection pump or the engine. The present invention provides a fuel/water separation device that prevents the occurrence of

Embodiments of the present invention will be described based on the drawings from FIG. 2 onwards.

In FIG. 2, the fuel injection pump 11 is connected to a fuel suction hole 12 provided in the fuel injection pump 11 and a fuel tank 13 through a fuel supply passage 16 equipped with a fuel filter 14 and a water separation tank 15. A fuel pump built into the fuel tank 11 supplies fuel in the fuel tank 13 into the pump housing.
The fuel in the pump housing is fed under pressure by a plunger pump (not shown), etc. to the delivery valve 1.
7 and a high-pressure passage 18 to an injection nozzle 19, from which fuel is injected into each combustion chamber of the engine. On the other hand, surplus fuel that has not been supplied to the injection nozzle 19 flows out from the outlet 20 of the fuel injection pump 11 into the fuel return passage 21, joins with the fuel flowing out from the spill port 22 of the injection nozzle 19, and flows into the fuel tank 13. be returned. 23 is a fuel cutoff valve installed in the fuel supply passage 16;
Configure fuel stop device. 24 is a manual priming pump.

FIG. 3 shows details of the water separation tank 15.

The water separation tank 15 has a fuel inlet 31 and a fuel outlet 32.
A filter 36 is attached to a drain pipe 35 that opens in the bottom wall of the case 34, and a drain valve 37 of an electromagnetic opening/closing type is provided below the drain pipe 35. magnet 4
The ring-shaped float 42 equipped with 1 is connected to the lid body 33
The outer periphery of the guide body 43, which is fixedly installed and suspended, is slid up and down depending on the specific gravity of the case 34 and the level of the water stored therein. 43a is a stopper for the float 42 provided at the lower end of the guide. The guide body 43 is made of a non-magnetic material, and has a first reed switch 44 constituting a low level sensor inside.
and a second reed switch 45 constituting a high level sensor are connected in parallel. The positive terminal of the first reed switch 44 is connected to the ignition switch 52 via an alarm lamp 51 as shown in FIG. and is connected to the ignition switch 52. The relay coil 53 turns on the relay switch 54 by being energized and energized, and applies the voltage of the battery 55 to the fuel cutoff valve 23 and the drain valve 37. In addition, 5
7 is the voltage regulator and its L (lamp)
By connecting the ground terminal of the alarm lamp 51 to the terminal, the lamp lights up when the key is put in before starting, and is used to check the function of the device in the same way as other alarm lamps (for example, oil pressure). It is.

According to this configuration, the fuel in the fuel supply passage 16 is sucked into the fuel injection pump 11 by the fuel injection pump 11 via the fuel filter 14, the water separation tank 15, and the fuel cutoff valve 23. In this state, the fuel cutoff valve 23 is open and the drain valve 37 is closed. Fuel is water separation tank 1
When water is mixed into the fuel during the process of flowing through the fuel, it is separated into two layers due to the difference in specific gravity, with the water being located in the lower layer and the fuel being located in the upper layer. As the level of water stored at the bottom of the case 34 rises, the float 42 moves upward, and the magnet 41 fixed thereto first closes the first reed switch 44 by its magnetic force. Therefore, the current of the battery 55 is
1. Since it is grounded via the first reed switch 44, the alarm lamp 51 lights up and the water separation tank 1
Warning to drain the water stored in the tank at the earliest opportunity. The alarm lamp 51 may be a buzzer, as long as it emits a different alarm from the alarm device connected to the second reed switch 45, or both may be provided together. At this stage, the drain pipe 35 can be freely attached to and detached from the case 34, or the excitation circuit of the drain valve 37 can be closed by the push button 56, and the drain pipe 35 can be freely attached to and detached from the case 34.
5, the water stored in the case 34 can be taken out to the outside. At this time, the filter 36 generates rust in the fuel tank due to the presence of moisture in the fuel, and if the rust powder accumulates in the case 34, it may adhere to the valve seat of the drain valve 37. It has a function of filtering out these impurities upstream of the drain valve 37 so as not to impair the sealing performance of the valve.

Even if the warning lamp 51 lights up, if you neglect or forget to drain the water as described above, or if the fuel tank 1
If a large amount of water is stored in the tank 3 and all of it flows into the water separation tank 15 at once, case 3
The water level inside 4 further rises and reaches near the second reed switch 45. At this time, the magnet 41 of the float 42, which has surfaced due to the rising water level,
The reed switch 45 of
Ground through. Therefore, the driving vehicle is informed of the occurrence of such a situation by the alarm buzzer 51A, and
When the relay switch 54 is closed, the fuel cutoff valve 23
is energized and excited to shut off the fuel supply passage 16 and open the drain valve 37. Therefore, since the fuel injection pump 11 is no longer supplied with fuel, the intrusion of water can be stopped beforehand, and the injection supply of fuel from the injection nozzle 19 is stopped, so that the rotation of the engine is stopped. Since the alarm buzzer 51A is activated when the engine is stopped, the driver is clearly notified that the cause of the engine stop is the rise in the water level in the case 34 and not other causes. Then, it is sufficient to simply wait for the water drain valve 37 to open and the water to be drained from the case 34 without examining other causes or taking other measures. On the other hand, when the water drain valve 37 is opened, the water stored in the case 34 is released to the outside, and when the water level drops and the float 42 reaches a position below the vicinity of the second reed switch 45,
The second reed switch 45 opens again, turning off the relay switch 54. For this reason, drain valve 3
At the same time as the valve 7 closes, the fuel cutoff valve 23 opens and the fuel suction action of the fuel injection pump 11 is resumed, allowing the engine to rotate.

In this way, when the water stored in the case 34 is at a low level, a request is made to drain the water, and when the water level rises further and reaches a predetermined high level, it is distinguished from the low level. By issuing a warning and automatically stopping the fuel and draining water, the driver is clearly notified that the cause of the engine stoppage is the high water level inside the case 34. Since the water level is clearly indicated by a high water level alarm, there is no need to bother with inspection work for other causes, and the fuel injection pump 11
Since water does not flow into the fuel injection pump 11, it is possible to reduce the amount of fuel supplied due to seizure of various moving parts within the fuel injection pump 11, and prevent engine stall due to this. Damage to the pump 11 can be prevented from burning.

In the above embodiment, the opening action of the drain valve 37 is performed by the low level sensor, that is, the first reed switch 4.
Of course, this may be performed at the stage where 4 is closed. Alternatively, as shown in FIG. 5, once a high level is reached and water draining and oil supply stop begins, it may continue until reaching a low level. Furthermore, it is also possible to easily recover the fuel cutoff valve 23 by changing the electric circuit when the water level drops below the high level. On the other hand, in the embodiment, a magnet 41 with a low level sensor and a high level sensor fixed to a float 42 and a reed switch 4 are connected to each other.
Although the switch configuration is not limited to this, other known water levels may be used, such as using a thermistor or using the difference in dielectric constant of fuel and water to detect the water level. It goes without saying that detection means can be used. Further, in the embodiment, an example was shown in which the present invention was applied to a fuel injection type internal combustion engine equipped with an injection pump, but it is obvious that the present invention can be applied to, for example, a carburetor type gasoline engine without an injection pump. In this case, the moisture that enters the fuel tank is separated by the water separation tank and removed, thereby preventing the supply of moisture and impurities into the fuel system and combustion chamber, which causes the inconvenience of damaging these parts. can be removed.

As described above, according to the present invention, a low level sensor for detecting a low water level and a high level sensor for detecting a high water level are provided in a water separator installed in a fuel supply passage, and the low level sensor detects a predetermined water level. When it detects water, it activates an alarm system to remind you to drain the water.
While it is possible to prepare in advance so that water is not supplied to the fuel injection pump or engine, etc., if the water level rises further than this, the high level sensor will detect this and lower the water level. It issues an alarm that is distinct from the alarm at the time of the accident, and cuts off the fuel supply.
Therefore, moisture in the fuel is supplied to the fuel injection pump or the engine, and a reduction in engine output, damage to the fuel injection pump, and damage to the engine can be automatically prevented. Furthermore, the driver can receive warnings for high water levels, which are differentiated from warnings for low water levels.
It is possible to accurately detect that the cause of the engine stoppage is due to a rise in the water level in the water separation tank, and there is no need to bother with unnecessary inspections for other causes.In addition, fuel can be discharged together with water during water drainage work. can be prevented. When at least one of the two level sensors detects a predetermined water level, the water in the water separation tank is automatically drained based on this output signal by operating a water drain valve, which prevents fuel injection. The injection of moisture into the pump or engine is more reliably prevented, and if the engine stops due to high water levels, it can be detected that the engine can be restarted by waiting for the extraction work time, and other causes of the stoppage can be detected. Inspection work becomes unnecessary.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view of the water level detection means of a conventional fuel/water separator, Fig. 2 is a system diagram of a fuel circulation system equipped with the fuel/water separator of the present invention, and Fig. 3 is a schematic sectional view of the water level detection means of a conventional fuel/water separator. A vertical cross-sectional schematic diagram showing one embodiment of the water separation device, FIG. 4 is an electric circuit diagram of the device of this embodiment, and FIG.
The figure is another electrical circuit diagram. 11...Fuel injection pump, 13...Fuel tank, 15...Water separation tank, 16...Fuel supply passage,
23...Fuel cutoff valve, 37...Drain valve, 44...
...First reed switch, 45...Second reed switch, 51...Warning lamp.

Claims (1)

[Claims] 1. A water separation tank provided in a fuel supply passage of an internal combustion engine, and a low level sensor and a high level sensor that respectively detect two high and low levels of water stored in the water separation tank; An alarm device that issues an alarm in response to the output of the low level sensor; an alarm device that issues another alarm distinct from the low water level alarm device when the high level sensor detects a high water level; and a fuel supply passage. A fuel/water separation device for an internal combustion engine, comprising a fuel stop device that shuts off the fuel. 2. A water separation tank provided in the fuel supply passage of the internal combustion engine, a low level sensor that detects two high and low levels of water stored in the water separation tank, and a sensor that receives the outputs of the high level sensor and the low level sensor. an alarm device that issues an alarm when the high level sensor detects a high water level; an alarm device that issues another alarm distinct from the low water level alarm device when the high level sensor detects a high water level; and a fuel stop device that shuts off the fuel supply passage. A fuel/water separation device for an internal combustion engine, comprising: a water draining device that receives a detection signal from at least one of a low level sensor and a high level sensor and drains water from a water separation tank.