JPS62279254A - Fuel injection engine - Google Patents

Abstract

PURPOSE: To prevent the seizing of the sliding part of a fuel injection pump by providing a fuel level detector for detecting the fuel level in a fuel tank and automatically decelerating the engine speed of an engine under a specified condition of said fuel level. CONSTITUTION:A fuel injection pump 15 is driven being interlocked with the rotation of an engine 13. Fuel in a fuel tank 23 is sent by pressure into the combustion chamber of the engine due to the drive of the fuel injection pump 15. The fuel level in the fuel tank 23 is detected by a fuel level detector 48. And, the engine speed of the engine 13 is automatically decelerated in a condition that the fuel level becomes below a defined level. The idle rotating speed and the idle rotating time of the fuel injection pump 15 which is idly rotated in a condition of no fuel can also be restrained low. Thereby, the seizing of the sliding part of the fuel injection pump 15 can be prevented.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a fuel injection engine suitable for use in outboard motors and the like.

[Prior Art] A fuel injection engine is a fuel injection engine in which an outboard motor, etc. is equipped with a fuel injection pump that is driven in conjunction with the rotation of one engine, and the fuel in the fuel tank is pumped into the combustion chamber of the engine by driving the fuel injection pump. is used.

Here, the fuel injection pump is supplied from the fuel tank,
The fuel that it pumps itself causes each part of the pump to squeak and slide, ensuring smooth operation.

[Problems to be Solved by the Invention] However, in the conventional fuel injection engine described above, if the fuel in the fuel tank becomes empty while the engine is rotating, the engine will rotate at a considerable rotational speed due to inertia force. It continues to rotate over time. At this time, the fuel injection pump operates in conjunction with the rotation of the engine in a state where there is no fuel (in a state where air is introduced).
You will end up idling. In this case, there is a risk that the sliding parts of the fuel injection pump will seize due to insufficient lubrication, resulting in a serious problem in which it will be impossible to restart the engine.

An object of the present invention is to prevent the fuel injection pump from idling, which would cause seizure of the sliding parts of the fuel injection pump when the fuel in the fuel tank becomes empty.

[Means for Solving the Problems] The present invention includes a fuel injection pump that is driven in conjunction with the rotation of the engine, and the fuel in the fuel tank is pumped into the combustion chamber of the seven engines by driving the fuel injection pump. In a fuel injection engine, a fuel level detector detects the fuel level in a fuel tank, and when the fuel level falls below a predetermined level, the rotational speed of the engine is automatically reduced.

[Operation] According to the present invention, when the fuel level in the fuel tank falls below a predetermined level and approaches the time when the fuel becomes empty, the rotational speed of the engine is automatically reduced.

As a result, the rotational speed of the engine when the fuel is completely empty is reduced, the inertia of each engine is also reduced, and the rotational speed and rotation time of the engine can be kept low based on the inertia after the fuel runs out. It becomes possible. Therefore, the idling speed and idling time of the fuel injection pump, which is linked to the engine and runs idly when there is no fuel, can be kept low, and it is possible to prevent idling to the extent that the pump's sliding parts may seize. becomes. This allows the fuel injection engine to
It is possible to smoothly drive and restart the fuel injection pump.

[Example] Fig. 1 is a schematic diagram showing an outboard motor to which the present invention is applied;
The figure is a partially cutaway plan view of the fuel injection engine in Figure 1;
Figure 3 is a sectional view showing the fuel injection pump in Figure 1, Figure 4 is a sectional view taken along the rV-rV line in Figure 3, and Figure 5 is a partially cutaway view of the main tank in Figure 1. 6 is a partially cutaway side view of the sub-tank shown in FIG. 1, and FIG. 7 is a circuit diagram showing an engine deceleration control circuit.

The outboard y110 can be attached to the hull 11, and has a two-cylinder fuel injection engine 13 mounted on top of its propulsion unit 12.

The engine 13 includes a fuel injection pump 15 on the side of the engine body 14.
It is equipped with The injection pump 15 has teeth on a pulley 18 fixed to an intermediate transmission shaft 17 that is gear-connected (not shown) to an injection pump shaft 16 to be described later, and on a pulley 20 fixed to a crankshaft 19 of the first engine 13. Attached belt 21
By winding it around, it is driven in conjunction with the rotation of the engine 13.

Here, the injection pump 15 has a built-in vane type feed pump 22, as shown in FIGS. The injection pump shaft 16 is transmitted via
As shown in FIG. Suction.

The oil pressure sent by the feed pump 22 is controlled by the action of a pressure regulating valve 29, allowing fuel to be sent to the pump chamber 30. The pump plunger 31 of the injection pump 15 is driven by a cam plate 32 connected to the injection pump shaft 16, rotates and reciprocates, and after sucking fuel from the pump chamber 30, corresponds to each cylinder of the engine 13. It is possible to inject high pressure into the combustion chamber 37 of each cylinder from an injection nozzle 36 provided in a cylinder head portion 35 corresponding to each cylinder of the engine 13 through a distribution passage 33, a distribution valve 34, and a distribution port 34A. 38 is a fuel pressure pipe. Note that the spray layer from the spray nozzle 36 can be controlled by moving a spill ring 41 that is operated by driving a slide lever 40. 3LA is pump plunger 3
This is a closing screw for the first housing space. Injection nozzle 36
The fuel sent under pressure by the feed pump 22 that exceeds the amount distributed to the sub tank 26 is transferred from the return pipe 22A to the sub tank 26 via the check valve 22B.
will be returned to. At this time, the air accumulated in the upper part of the pump chamber 30 is carried along with it, making it possible to automatically bleed air from the pump chamber 3o.

- The injection pump 15 lubricates each part of the pump with fuel supplied from the sub-tank 26 and pumped by itself to ensure smooth operation.

Note that the engine 13 includes a spark plug 42 in the cylinder head portion 35 corresponding to each cylinder.

43 is an ignition coil.

Here, the main tank 23 is constructed as shown in FIG. That is, a supply port 44 to which the cap 23A is screwed is formed in the ceiling of the main tank 23, and a connection port 4 to which the suction pipe 23B is connected is formed in the side surface on the bottom side.
5 is formed. 23C is a pump, and 23D is a pump pipe. Note that the cap 23A is provided with a check valve 46 that is opened when pumping fuel and makes it possible to maintain the space inside the main tank 23 at atmospheric pressure. The main tank 23 is set with an oil level called a caution oil level 47, and has an oil level detector 48 built therein which forms a caution means. The oil level detector 48 includes a plug 50 that fits into an opening provided in the ceiling of the main tank 23;
The main tank 23 has a cylindrical part 51 that hangs down from the lower surface of the main tank 23 to near the bottom of the main tank 23, and a plurality of communication holes 52 that allow fuel to flow therethrough, and is fixed to the cylindrical part 51 so as to cover the lower part of the cylindrical part 51. a float 54 that is movable up and down in a ring-shaped space between the cylindrical portion 51 and the housing 53;
, a reed switch 55 installed at a level corresponding to the caution oil level 47 in the cylindrical portion 51 , and a magnetic ring 56 fixed to the float 54 to turn on the reed switch 55 . Here, the housing 53 of the oil level detector 48 is fixed to the cylindrical part 51 so that the inner surface of its upper end substantially coincides with the caution oil level 47, and the float 54
The upper limit position of the housing 53 is regulated by contact with the inner surface of the upper end portion of the housing 53. That is, when the oil level in the main tank 23 is located above the caution oil level 47, the oil level detector 48 detects the reed switch 55 by the magnetic ring 56 of the float 54 that remains at the upper limit position.
is maintained in the ON state, and the reed switch 55 is turned OFF while the oil level in the main tank 23 is lower than the caution oil level 47 and the magnetic ring 56 of the float 54 is lowered to the same level as the actual oil level. This makes it possible to perform cautionary actions, which will be described later.

Next, the sub tank 26 is constructed as shown in FIG. That is, a connection port 57 to which the pumping pipe 23D is connected is formed in the side surface on the ceiling side of the sub-tank 26, and a connection port 57 to which the suction pipe 26A is connected is formed in the bottom of the sub-tank 26. There is. In addition, sub tank 26
A check valve installation chamber 59 provided in a part of the ceiling includes a check valve 60 that opens when fuel is pumped up, and a check valve 61 that opens when fuel is supplied to the injection pump 15. The space inside the sub-tank 26 is always maintained at atmospheric pressure, and the pump 23C1 and the injection pump 15 are smoothly driven.

The sub-tank 26 has a full oil level 62A and a supplementary oil level 62A.
Three oil level levels, 2B and a warning oil level 62C, are set, and an oil level detector 63 is built in, which forms full oil level detection means, replenishment oil level detection means, and warning means.

The oil level detector 63 includes a stopper 65 that fits into an opening 64 provided in the ceiling of the sub-tank 26 and a cylindrical part 66 that hangs down from the bottom surface of the stopper 65 to near the bottom of the sub-tank 26.
The plug body 65 and the cylindrical portion 66 are provided with a plurality of flow holes 67 that allow fuel to flow therethrough, and the plug body 65 and the cylindrical portion 66 are arranged so as to cover the entire length of the cylindrical portion 66.
a float 69 that moves up and down in the ring-shaped space between the cylindrical part 66 and the housing 68 according to changes in the oil level; Reed switch 70A installed in
, 70B, 70C, and each reed switch 70A to 70 is fixed to a float 69 and located at the same level as the actual oil level.
It is composed of a magnetic ring 71 that performs 0Ct-ON operation. That is, the oil level detector 63
Depending on the oil level change in each reed, switch 70A~7
By turning on the QC, it is possible to perform a pumping operation and a warning operation, which will be described later. The float 69 contacts the lower surface of the stopper 65 and the bottom surface of the housing 68 at its upper limit position and lower limit position, respectively, and is able to maintain the ON state of the reed switches 70A to 70C.

Here, a control box 72 is fixed to the side of the first engine L3,
The pumping operation, caution operation, and warning operation in this embodiment can be controlled by the electric circuit shown in FIG. In addition, in FIG. 7, 573 is a battery, and 74
is the power switch, 75 is the pump 23C motor,
76 is an emergency switch, 77 is a tilt switch, 78 is a green normal light, 79 is a yellow caution light, 80 is a red warning light,
81 is a warning buzzer, 82 is an injection amount control device, and 83 is a temperature detector. 84 is a flip-flop circuit (bistable multivibrator), 85 to 87 are transistors, 88
-97 are resistors, and 98-104 are diodes. Further, each point PL, P2) P3, P4, P5 is connected to the opposite side of the power switch 74 from the battery.

Hereinafter, the pumping operation and caution operation 1g alerting operation in this embodiment will be sequentially explained.

First, the pumping operation will be explained. The oil level in the sub-tank 26 drops from the full oil level 62A due to fuel consumption,
When the supply oil level 62B is reached, the float 69 also descends,
The magnetic ring 71 turns on the reed switch 70Bt. The ON signal of the reed switch 70H changes the flip-flop circuit 84 in the control box 72 to a zero potential output state and turns off the transistor 85, so the transistor 86 is turned on and the motor 75 of the pump 23C starts driving. Then, the fuel in the main tank 23 is pumped up into the sub tank 26. When the pump 23C starts pumping, the float 69 and the magnetic ring 71 rise, and the reed switch 70B is turned off again. However, the zero potential output state of the flip-flop circuit 84 does not change, and the motor 75 of the pump 23C continues driving. The flow rate of the fuel pumped up by the pump 23C is set to be larger than the maximum injection amount of fuel pumped by the injection pump 15, and therefore the oil level in the sub-tank 26 rises to reach the full oil level 62A. At this time, the float 69 also rises in response to the rise in the oil level, and the magnetic ring 71 turns the reed switch 70A ONL, changes the flip-flop circuit 84 to a positive potential output state, and turns on the transistor 85. 86 is turned off, the motor 75 of the pump 23C stops, and pumping of fuel is stopped. In addition, if fuel is consumed after the pump 23C stops pumping,
Although the magnetic ring 71 of the float 69 is lowered and the reed switch 70A is turned off again, the positive potential output state of the flip-flop circuit 84 does not change, and the pump 23
C is maintained in its stopped state. Normally, by repeating the pumping operation described above, the lubricating oil in the sub-tank 26 can be maintained between the full oil level 62A and the supply oil level 62B.

Here, a tilt switch 77 that is turned on when the outboard motor is tilted up or above a predetermined tilt angle is disposed in the control box 72, and the outboard motor travels in a tilt-up or trim-up state and responds to changes in its traveling attitude. Even when the float 69 descends due to the oil level change in the sub-tank 26 and turns on the reed switch 70B, the transistor 86 is maintained in the OFF state by turning on the tilt switch 77, and the motor 75 of the pump 23C is turned on. By keeping it in a stopped state, sub tank 2
This makes it possible to prevent overflow caused by excessive pumping to 6.

In addition, during the above-mentioned normal pumping operation, the oil level in the main tank 23 is located at a level above the caution oil level 47, and the magnetic ring 56 of the float 54 in the main tank 23 is at its northern limit position as described above. stop, reed switch 55
The green normal light 78 remains on.
is lit.

Next, we will use it for attention actions. That is, after the normal pumping operation described above, when the oil level in the main tank 23 reaches a level below the caution oil level 47 and the remaining amount becomes below a predetermined value, the float 54 and the magnetic ring 56 are activated to prevent the oil level from decreasing. At the same time, the reed switch 55 is turned off.

Therefore, in this case, reed switch 55. Since both reed switches 70C are turned off and the transistor 87 is turned on, the yellow color caution light 79 is turned on to warn the driver that the remaining amount of the main tank 23 is low. Further, in this case, since the transistor 85 is turned on when the reed switch 55 is turned off, the transistor 86 is turned off, and the motor 75 of the pump pump 23C is immediately stopped regardless of the oil level state in the sub-tank 26. . Therefore, in response to these warnings, the driver can calculate the cruising distance with the remaining fuel and formulate a safe cruising plan.

The motor 75 of the pump 23G, which has stopped when the reed switch 55 is turned off, can be driven again by the driver manually turning on the emergency switch 76. Pour the remaining fuel into the sub tank 26.
It is possible to pump up water to

Next, the warning operation will be explained. Namely.

After the above-mentioned caution operation has passed, the supply of fuel to the sub-tank 26 is cut off, and the oil level in the sub-tank 26 drops from the replenishment oil level 62B as fuel is consumed, and when it reaches the warning oil level 62C, the float 69 also lowers. Then, the magnetic ring 71 turns on the reed switch 70C, so the red warning light 8
0 will be lit. In this case, even if the oil level in the main tank 23 is below the caution oil level 47 and the reed switch 55 is in the OFF state, the transistor 87 is in the OFF state because the reed switch 70C is in the ON state. In this case, the reed switch 70C is turned on, the warning buzzer 81 sounds, and the injection amount control device 82 automatically adjusts the carrot rotation speed. Slowed down.

The injection amount control device 82 drives and controls the slide lever 40 of the injection pump 15 to reduce the amount of injection from the injection nozzle 36 by moving the spill ring 41 described above, thereby automatically reducing the rotational speed of the engine 13. to become

That is, according to the embodiment described above, when the fuel level in the sub-tank 26 falls below a predetermined level and approaches the time when the fuel becomes empty, the rotational speed of the engine 13 is automatically reduced. As a result, the rotational speed of the engine 13 when the fuel is completely empty is reduced, and the inertial force of the engine 13 is also reduced.
It becomes possible to keep the rotation speed and rotation time of the engine 13 low based on the inertia force after the fuel runs out. Therefore, the idling speed and idling time of the fuel injection pump 15, which is interlocked with the engine 13 and idling when there is no fuel, are kept low, and idling to the extent that would cause seizure of the sliding parts of the pump 15 is prevented. becomes possible. As a result, the fuel injection engine 13 is operated by the fuel injection pump 15 after being refilled with fuel.
It is possible to drive and restart the engine smoothly.

Note that the injection amount control device 82 is also connected to a temperature detector 83 made of a bimetal or the like that is turned on when the engine is overheated, through a connection terminal 110. Therefore, one engine 13
Not only when the oil level in the sub-tank 26 is low,
Even when the temperature detector 83 is turned on due to overheating, the engine rotational speed is automatically reduced, making it possible to prevent the overheating state from continuing.

Further, in the above embodiment, the rotational speed of the engine 13 is reduced using the injection amount control device 82, but in the implementation of the present invention, an ignition control device may be used instead of the injection amount control device 82. good. That is, when the oil level in the sub-tank 26 falls below a predetermined level, the ignition operation by the spark plug 42 is caused to misfire at an appropriate cycle, so that the engine 13
The rotation speed may be automatically reduced.

FIG. 8 is a schematic diagram showing a modification of the present invention.

This modification differs from the embodiment shown in FIGS. 1 to 7 above in that the sub-tank 26 is removed as a fuel tank and only the main tank 23 is used, and that the injection pump 15 is not provided with a fuel feed pump. A diaphragm fuel feed pump 2 driven by the pulsation of pressure in the crank chamber of the engine 13
The reason is that 00 was set. In this case, the main tank 23
The fuel level in the main tank 23 is detected by the oil level detector 48 provided therein, and when the fuel level is below a predetermined level, the rotational speed of the engine 13 is automatically adjusted in the same manner as in the previous embodiment. [Effect of the Invention] As described above, the present invention includes a fuel injection pump that is driven in conjunction with the rotation of the engine, and pressurizes the fuel in the fuel tank into the combustion chamber of the engine by driving the fuel injection pump. In the fuel injection engine, the fuel level in the fuel tank is detected by a fuel level detector, and the rotational speed of the engine is automatically reduced when the fuel level is below a predetermined level.

That is, according to the present invention, when the fuel level in the fuel tank falls below a predetermined level and approaches the time when the fuel is empty, the rotational speed of the engine is automatically reduced. As a result, the rotational speed of the engine when the fuel is completely empty is reduced, the inertia of the engine is also reduced, and the rotational speed and rotation time of the engine can be kept low based on the inertia after the fuel runs out. It becomes possible. Therefore, linked to the above institutions.

The idle speed of a fuel injection pump that idles without fuel,
The idling time is also suppressed to a low level, and it is possible to prevent idling to the extent that it may cause seizure of the sliding parts of the pump. Thereby, the fuel injection engine can smoothly drive the fuel injection pump and restart after replenishing the fuel.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an outboard motor to which the present invention is applied;
The figure is a partially cutaway plan view of the fuel injection engine in Figure 1;
Figure S3 is a sectional view showing the fuel injection pump in Figure 1, Figure 4 is a sectional view taken along the IT-IT line in Figure 3, and Figure 5 is a partially cutaway side view of the main tank in Figure 1. 6 is a partially cutaway side view of the sub-tank shown in FIG. 1, FIG. 7 is a circuit diagram showing an engine deceleration control circuit, and FIG. 8 is a schematic diagram showing a modification of the present invention. 13...Fuel injection engine, 15...Fuel injection pump,
23...Main tank, 26...Sub tank, 37...
- Combustion chamber, 48... Oil level detector, 63... Oil level detector, 72... Control box, 82... Injection amount control device. Agent Patent Attorney Osamu Shiokawa Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (2)

[Claims] (1) In a fuel injection engine that is equipped with a fuel injection pump that is driven in conjunction with the rotation of the engine, the fuel in the fuel tank is pumped into the combustion chamber of the engine by driving the fuel injection pump,
A fuel injection engine characterized in that a fuel level detector detects a fuel level in a fuel tank, and when the fuel level is below a predetermined level, the rotational speed of the engine is automatically reduced. (2) The fuel injection engine according to claim 1, wherein the engine is a spark ignition type fuel injection engine, and the rotational speed of the engine is reduced by misfiring the ignition operation.