JP2844706B2 - Fuel injection device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improved governor structure for a fuel injection device for a diesel engine.

[Problems to be solved by conventional technology and invention]

The governor of the diesel engine fuel injection system has a function to increase or decrease the fuel injection amount of the fuel injection pump according to the driver's accelerator operation, and the fuel injection according to the load to maintain the engine speed at the set value. Some have the function of increasing or decreasing the amount, but all of them are required to have good operation responsiveness and high reliability.

In order to improve the above responsiveness and reliability, it is effective to use a forced lubrication system in which lubricating oil pressurized from an engine lubricating oil pump is supplied to sliding parts in the governor to reduce sliding friction of each part of the governor. .

However, in the conventional governor, when the engine is started particularly when the engine temperature is low, a problem may occur because low-temperature lubricating oil is supplied from the engine to the governor. In other words, in the conventional governor, the lubricating oil whose viscosity is increased due to the low temperature is supplied to the sliding portion in the banana, so that the operating resistance of the members due to the flow resistance of the lubricating oil increases and the governor responsiveness decreases. I was This decrease in governor responsiveness appears as unstable rotation when starting the engine.Especially when the engine speed is increased by depressing the accelerator with no load immediately after starting, the engine speed sharply increases, There is a problem that a so-called engine blow-up that does not decrease even if the pressure is returned.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to prevent a high-viscosity lubricating oil from being supplied to a governor at the time of starting an engine, and to improve low-temperature starting characteristics of a fuel injection pump such as governor responsiveness.

Incidentally, Japanese Utility Model Publication No. 61-17149 discloses an invention in which the operation of a boost compensator of a supercharged internal combustion engine is corrected in accordance with the ambient temperature by using a spring made of a shape memory alloy. It does not indicate.

[Means for solving the problem]

In the present invention, when the lubricating oil temperature is lower than a set value, such as when starting the engine at a low temperature, the lubricating oil supply to the governor is stopped to prevent an increase in the operating resistance of the governor internal operating member due to the high-viscosity lubricating oil. A valve is provided.

[Action]

With the above configuration, when the lubricating oil temperature is low, such as when the engine is started at a low temperature, the piston of the shut-off valve is biased by the spring and comes to the position where the lubricating oil passage is closed, so that the supply of the pressure lubricating oil to the governor is performed. Will be shut off. Therefore, it is possible to prevent the low-temperature high-viscosity lubricating oil from being supplied to the governor and increasing the operating resistance of the member. When the lubricating oil temperature rises due to the warm-up operation after the engine is started and exceeds the set temperature, the temperature sensing member pushes the valve body against the bias of the spring and moves to a position where the lubricating oil passage is opened. Let it. Therefore, the governor is supplied with the pressure lubricating oil. Therefore, only the lubricating oil whose viscosity has been sufficiently lowered at the set temperature or higher is supplied to the governor.

〔Example〕

FIG. 1 shows an embodiment of the fuel injection device of the present invention. In the figure, reference numeral 30 denotes an electric governor of the fuel injection pump, which adjusts the fuel injection amount by transmitting the operation of the movable iron core 18 of the electromagnetic actuator 15 to the fuel pump 14 via the fuel injection amount adjusting member 19. The movable iron core 18 is supported by bearings 16 and 17, and slides on the bearings 16 and 17 in the axial direction according to an accelerator opening signal. The position of the movable iron core 18 is detected by a position detecting member 21 supported by a bearing 22 via a link 20, and is converted into a fuel injection amount signal and output. Also,
Reference numeral 23 denotes a cam shaft of the fuel injection pump 14, and a rotation speed detecting gear 24 is provided at an end thereof.

Lubricating oil is pumped into the governor 30 from a lubricating oil pump of an engine (not shown) via a pipe 7 and a shutoff valve 100 which is a feature of the present invention. Via the electromagnetic actuator movable iron core 18
After being supplied to the bearings 16 and 17 and lubricating the sliding portions, the lubricant flows into a lubricating oil reservoir in the governor housing through a lubricating oil return passage 26 provided in the governor cover 25, and thereafter returns to the engine.

As shown in FIG. 2, the shutoff valve 100 includes a housing 1, a piston 2 as a valve body slidably provided in the housing 1, and a stopper 5 attached to an end of the housing via a gasket 6.
The piston 2 is pressed and urged in opposite directions by springs 3 and 4 disposed on both sides thereof. An oil passage 8 is provided in the housing 1 of the shut-off valve 100, one end of which is connected to an annular groove 9 provided on the inner surface of the cylinder that houses the piston 2, and the other end of which is connected to a lubricating oil pipe from an engine lubricating oil pump. It is connected. In this embodiment, the housing 1 of the shut-off valve 100 is attached to a governor housing 11 by screwing, and is fixed by a nut 10 so that the lubricating oil passage 12 of the governor housing communicates with the cylinder bottom receiving the piston 2. Has been. Further, the piston 2 is provided with an oil passage 13 communicating the both end surfaces of the piston, so that the pressure on both end surfaces of the piston 2 is balanced so that the operation of the piston 2 is not hindered by the pressure difference between the both end surfaces. Has been. The piston 2 includes the springs 3 and 4 as described above.
However, the annular groove 9 communicating with the oil passage 8 is closed by the piston side surface when the spring 4 moves in the direction urged by the spring 4, that is, in the cylinder bottom direction. Lubricating oil does not flow from the oil passage 8. Also, the piston 2 moves in the direction of the stopper 5 by the spring 3 in the opposite direction,
Stepped portion where spring 3 is attached to piston 2 and annular groove 9
And the oil passage 8 communicates with the lubricating oil passage 12 in the governor housing, and the lubricating oil is supplied from the engine lubricating oil pump to the electromagnetic actuator 15 of the governor 30 via the pipe 7, the oil passage 8, and the lubricating oil passage 12. Is supplied.

In this embodiment, the spring 3 is made of a shape memory alloy. When the temperature exceeds the set temperature T as shown in FIG. 4, a large force acts to restore the spring length stored in advance, The spring reaction force at the time of compression changes around the set temperature T. On the other hand, the spring 4 is made of a normal material, and the spring reaction force in the compressed state has a constant value regardless of the temperature.

The relationship between the set values of the spring reaction force when the springs 3 and 4 of this embodiment are mounted is such that the spring reaction forces of the springs 3 and 4 are reversed at the set temperature T as shown in FIG. Have been. The shut-off valve 100 performs a shut-off / opening operation using this spring characteristic.
FIG. 2 and FIG. 2 show a state where the spring 3 is lower than the set temperature T. This state corresponds to a state in which the lubricating oil temperature is low immediately after the start of the engine. Under this temperature condition, the spring 2 has a larger spring reaction force than the spring 3 as shown in FIG. It has been pushed to the position shown in FIGS. 1 and 2. In this position, the annular groove 9 is closed on the side surface of the piston 2, the flow of the lubricating oil from the oil passage 8 to the lubricating oil passage 12 is cut off, and the low-temperature lubricating oil is not supplied into the governor. This shut-off valve is not provided, and low-temperature lubricating oil flows through lubricating oil passage 12 (Fig. 1).
When the lubricating oil is supplied to the governor 30, the flow resistance in the lubricating oil outlet passage 26 from the electromagnetic actuator 15 increases because the viscosity of the lubricating oil is high, and the amount of the lubricating oil discharged from the outlet passage 26 is reduced. As a result, the lubricating oil is filled inside the electromagnetic actuator 15. Since the operation of the movable iron core 18 is disturbed by the filled lubricating oil, the responsiveness of the governor is deteriorated, and the above-described problem such as the engine speed-up occurs. When the lubricating oil temperature is high and the viscosity is sufficiently low, the amount of lubricating oil discharged from the lubricating oil outlet passage 26 is sufficiently large that the electromagnetic actuator 15 is not filled with lubricating oil.

Next, FIG. 3 shows the state of the shut-off valve 100 when the engine is warmed up and the lubricating oil temperature exceeds a set value. In this state, the strength of the spring reaction force of the springs 3 and 4 is reversed, and the spring reaction force of the spring 3 increases. Therefore, the piston 2 is pushed by the spring 3 and moves in the direction of the stopper 5 to move the annular groove 9. To be exposed, the oil passage 8 communicates with the lubricating oil passage 12 of the governor housing 11 and supplies the electromagnetic actuator 15 with lubricating oil having a high temperature and a sufficiently reduced viscosity.

As described above, since the shut-off valve 100 has the function of stopping the supply of the lubricating oil to the governor 30 until the lubricating oil temperature exceeds the set value, the electromagnetic actuator 15 of the governor 30 is not changed until the lubricating oil temperature increases after the engine is started. Although the engine is operated with insufficient lubricating oil supply, the engine lubricating oil temperature rises to the set value in a short time after starting, so it is unlikely that the governor 30 will be adversely affected or the durability will decrease during this operation. Absent.

FIG. 5 shows an embodiment using a thermoactuator 38 having a cylinder 36 in which a thermowax 35 is sealed and a thermopiston 37 as a temperature sensing member instead of the shape memory alloy spring 3 of the embodiment of FIG. is there. In this case, the thermoactuator 38 is set so as to push the piston 2 according to the temperature and to open the groove 9 when the set temperature is reached. There is no difference.

〔The invention's effect〕

The present invention provides a shut-off valve in a lubricating oil supply passage to the fuel injection pump governor, and stops lubricating oil supply to the governor until the lubricating oil temperature reaches a set value or more.
Low-temperature lubricating oil is supplied to the governor when the engine is started or the like, thereby deteriorating the governor responsiveness and preventing the engine from becoming unstable.

[Brief description of the drawings]

FIG. 1 is a sectional view of a fuel injection pump governor according to the present invention,
2 and 3 are cross-sectional views showing the operation of the lubricating oil shut-off valve used in the embodiment, FIG. 4 is a diagram showing a change in the reaction force of the spring due to temperature, and FIG. Another embodiment. 1 ... housing, 2 ... piston, 3, 4 ... spring, 5
... Stopper, 6 ... Gasket, 8 ... Oil passage, 11 ... Governor housing, 12 ... Lubricant oil passage, 15 ... Electromagnetic actuator, 16,17 ... Bearing, 18 ... Movable iron core, 26 ... Lubricant outlet passage, 30 ... Governor , 35 ... Thermo wax, 37 ... Thermo piston, 38 ... Thermo actuator, 100 ... Lubricating oil shutoff valve.

Claims (3)

(57) [Claims] 1. A fuel injection device for an internal combustion engine having a governor for forcibly applying pressure lubrication oil from a lubrication oil circuit of the internal combustion engine, wherein a lubricating oil temperature is set to a predetermined value in a pressure lubricating oil supply passage to the governor. When it is lower, the pressure lubricating oil supply passage is shut off to stop the supply of the pressure lubricating oil to the governor, and when the lubricating oil temperature exceeds the set value, the pressure lubricating oil supply passage is opened and the pressure lubricating oil is supplied to the governor. A fuel injection device provided with a lubricating oil shutoff valve for supplying. 2. The lubricating oil shutoff valve includes a valve body biased by a spring in a direction to close the pressure lubricating oil supply passage, and a valve that opposes the spring when the lubricating oil temperature becomes equal to or higher than the set value. The fuel injection device according to claim 1, further comprising a temperature-sensitive member that pushes the valve body to open the pressure lubricating oil passage. 3. The fuel injection device according to claim 2, wherein said temperature-sensitive member is a shape memory alloy formed in a spring shape.