JP3676006B2 - Fuel injection pump control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel injection pump for an internal combustion engine, and more particularly to a control device for a jerk fuel injection pump for a diesel engine.
[0002]
[Prior art]
FIG. 4 is a plan view showing an example of a control device for a diesel engine.
In FIG. 4, 100 is an engine body, 1 is a fuel injection pump that pressurizes fuel and supplies it to a fuel injection valve (not shown), 12 is a governor that controls the rotational speed of the engine, and 2 is the fuel injection pump 1. It is a fuel rack that adjusts the fuel injection amount.
[0003]
In such a diesel engine, a mechanical governor whose output end is a shifter that changes depending on the balance between the force of the flyweight and the governor spring, and a hydraulic type whose output end is a power piston that operates hydraulically due to a change in engine speed The governor and an electronic governor having an output that is an actuator that is operated by analog or digital electronic control with the engine speed or load as an input are used. The output ends of these governors are the governor outputs shown in FIG. Connected to link 3.
[0004]
The governor output link 3 is connected to the fuel rack 2 via a connection link 4 fixed thereto. Reference numeral 7 denotes a bracket that supports the governor output link 3 so as to be slidable back and forth, and is fixed to the engine body 100 with bolts.
[0005]
During operation of a diesel engine equipped with such a fuel injection pump control device, the output from the governor 12 is transmitted to the governor output link 3 by increasing or decreasing the engine speed or load, and this reciprocates as indicated by the arrow Z in FIG. . This reciprocating displacement is transmitted to the fuel rack 2 via the connecting link 4, and the fuel rack 2 is reciprocated. As is well known by the reciprocating displacement of the rack 2, the plunger is rotated through the pinion of the fuel injection pump 1 to change the effective stroke thereof, thereby changing the fuel injection amount.
[0006]
[Problems to be solved by the invention]
In the diesel engine, various methods for injecting water together with fuel are provided in order to suppress generation of nitrogen oxide (NO _x ) in exhaust gas. In such a diesel engine, in the case of a system in which fuel and water are mixed and injected from a single fuel injection valve, the amount of fuel injected from the fuel injection pump 1 is much larger than that of fuel alone because water is added to the fuel. Need to increase.
[0007]
However, the governor 12 that controls the fuel injection control generally sets the maximum fuel control operation range at the maximum output of the engine on the premise that the injection amount control of only the fuel is performed. That is, in the prior art, in the fuel injection amount diagram shown in FIG. 5, the maximum fuel control value of the governor 12, that is, the maximum operating amount M1 of the governor and the maximum fuel injection amount Q1 corresponding thereto are set.
[0008]
Therefore, in such a diesel engine, when water is added as described above, the governor 12 operates beyond its operating range, that is, the maximum operating amount M1 by an amount corresponding to the increase in the injection amount. This causes a problem that the injection amount control by the governor 12 becomes impossible.
[0009]
In view of the problems of the prior art, the present invention can deal with an increase in the injection amount accompanying the injection of other fluids such as water injection without changing the maximum operation amount of the governor, that is, the operation range, It is an object of the present invention to provide a control device for a fuel injection pump that can freely switch between injection and fuel-only injection without changing the governor performance.
[0010]
[Means for Solving the Problems]
In order to solve this problem, the present invention provides a fuel injection pump control apparatus in which an output of a governor is transmitted to a fuel rack for adjusting a fuel injection amount of a fuel injection pump via a governor output link.
The governor output link and the fuel rack are connected to the governor output link so as to be able to reciprocate, and the fuel rack is inserted between the connection link and the governor output link to reduce the injection amount. And a fluid pressure cylinder having a cylinder fixed to the governor output link, a piston reciprocating in the cylinder, and an adjusting screw fixed to an end of the piston. The movement of the governor output link in the fuel increasing direction can be transmitted to the fuel rack via the cylinder, piston and adjustment screw, and the piston and adjustment screw are displaced in the direction of compressing the spring. The fuel rack is configured to increase the injection amount, and the working fluid supply path to the fluid pressure cylinder includes the piston of the fluid pressure cylinder and the adjustment screw. Supply to the fluid pressure cylinder of the hydraulic fluid for allowing moving, proposes a fuel injection pump control apparatus characterized by comprising providing a solenoid valve Nikki by Tsukasa blocking.
[0011]
Further, the present invention, in addition to the above means, connects the governor output shaft and the fuel rack via a connecting link, and interposes the spring between one end surface of the connecting link and the governor output link, When the end face of the adjusting screw is brought into contact with the surface of the connecting link opposite to the spring, and the adjusting screw is protruded, the fuel rack moves in the direction of increasing the injection amount through the connecting link. Configure.
[0012]
According to this invention, when the water (including other fluid) injection is supported, the solenoid valve is closed and the supply of the fluid to the fluid chamber on one side of the fluid pressure cylinder is shut off, so that the adjusting screw is The fuel rack is shifted to the injection amount increase position. That is, it is possible to increase the injection amount of the fuel injection pump without changing the position of the governor output link, that is, the governor operation amount, and to cope with the increase in the injection amount due to water injection.
[0013]
When shutting off water injection, if the solenoid valve is closed and the working fluid is supplied to both fluid chambers of the fluid pressure cylinder, the fuel rack will reduce the injection amount via the adjustment screw due to the area difference in the fluid pressure cylinder. The shift of the injection amount increase for the water injection is canceled by being pulled back in the direction.
[0014]
Therefore, by controlling the supply and discharge of the working fluid to and from the fluid pressure cylinder by the solenoid valve, the injection amount can be increased or decreased without changing the governor operation amount, and the governor is set to the maximum fuel injection amount. The injection amount can be increased by water injection within the corresponding maximum operating range.
[0015]
Further, the amount of increase in the injection amount can be arbitrarily adjusted by adjusting the protruding amount of the adjusting screw attached to the fluid pressure cylinder.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings.
However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only.
[0017]
FIG. 1 is a plan view of a main part of a fuel injection pump control device for a diesel engine according to an embodiment of the present invention, FIG. 2 is a structural diagram in the vicinity of an air cylinder mounting portion, and FIG.
[0018]
1 and 2, 1 is a fuel injection pump, 2 is a fuel rack for adjusting the fuel injection amount of the fuel injection pump 1, and 12 is a governor including the mechanical governor, hydraulic governor, electronic governor and the like.
[0019]
3 is a governor output link which is an output end of the governor 12, and 7 is a bracket which is fixed to the engine body 100 and supports the governor output link 3 so as to be reciprocally slidable.
Reference numeral 4 denotes a connecting link composed of a boss portion 4a and a lever portion 4b. The end of the lever portion 4b is fixed to the fuel rack 2, and the governor output link 3 can reciprocate in the insertion hole of the boss portion 4a. It is inserted.
[0020]
6 is a spring installed between the end face 4c of the boss 4a of the connecting link 4 on the governor 12 side and the spring receiving portion 3a formed on the governor output link 3, and is constituted by a compression spring, and the connecting link 4, the fuel rack 2 is urged in the direction of the injection amount “0” (zero) (the direction opposite to the Y arrow in FIG. 2).
Therefore, the governor output link 3 and the connection link 4 are not directly connected but are connected via the spring 6.
[0021]
Reference numeral 5 denotes an air cylinder in which a cylinder 5d is fixed to the governor output link 3. An adjustment screw 11 is attached to one end of a reciprocating piston 5a of the air cylinder 5, and a tip of the adjustment screw 11 is connected to the connecting link 4 The lever portion 4b is always brought into contact with the plate surface 4d on the side opposite to the governor (the plate surface opposite to the end surface 4c of the boss 4a) by the elasticity of the spring 6.
[0022]
5b is a first air chamber defined by the piston 5a of the air cylinder 5, 5c is a second air chamber, 9 is a main air pipe connected to the second air amount 5c, and 10 is first air. A pilot air pipe 8 connected to the chamber 5 b is an electromagnetic valve for opening / closing control provided in the pilot air pipe 10. The sectional area of the first air chamber 5b is larger than that of the second air chamber 5c.
[0023]
The second air chamber 5c of the air cylinder 5 is supplied with air constantly pressurized to a predetermined pressure through the main air pipe 9, and the first air chamber 5b is supplied with the pilot air. Air is supplied and disconnected by opening and closing the electromagnetic valve 8 through the pipe 10.
[0024]
During operation of the diesel engine using the fuel injection pump control device having such a configuration, when the governor output link 3 operates in the direction of fuel reduction, the governor output link 3 connects the spring 6 and the connection link 4 to each other. Thus, the fuel rack 2 is operated in the fuel decreasing direction (the direction opposite to the arrow Y in FIG. 2). When the governor output link 3 is operated in the direction of increasing fuel, the cylinder 5d fixed to the governor output link 3 as described above, the second air chamber 5c and the piston 5a in which the constant air pressure is applied, and the adjustment. The fuel rack 2 is actuated in the direction of increasing fuel (in the direction of arrow Y in FIG. 2) via the screw 11.
Then, when the electromagnetic valve 8 of the pilot air pipe 10 is closed, the first air chamber 5b is in a state where the pressurized air that has passed through the main air pipe 9 is supplied to the second air chamber 5c of the air cylinder 5. Air supply to is cut off. As a result, the piston 5a and the adjusting screw 11 of the air cylinder 5 displace the fuel rack 2 in the right direction of FIG. 2, that is, in the direction of increasing the injection amount indicated by the Y arrow, by an amount corresponding to the stroke of the piston 5a.
[0025]
That is, in FIG. 3, the fuel rack 2 is displaced in the direction of increasing the injection amount by c by the governor operating amount M2 (governor displacement amount a), and water is injected into the same governor operating amount M2 by an amount corresponding to this c. The amount will be tolerated.
[0026]
When the governor operation amount M increases in this state, the fuel rack 2 is displaced so as to increase the injection amount along the line A in FIG. 3, and fuel and water are injected.
Then, when the water injection is completed and the solenoid valve 8 is switched to open at the governor displacement amount b in FIG. 3, the pilot air (second air) which has passed through the pilot air pipe 10 into the first air chamber 5 b of the air cylinder 5. The same pressure as the air in the air chamber 5c is supplied.
[0027]
In response to this, the piston 5a is displaced together with the adjusting screw 11 in the direction opposite to the arrow Y in FIG. 2, that is, in the direction of decreasing the injection amount due to the cross-sectional area difference between the first air chamber 5b and the second air chamber 5c. The rack 2 is pushed back in the direction of decreasing the injection amount (from the point B to the point C in FIG. 3) with the same governor operation amount M3 through the connecting link 4 by the elasticity of the spring 6.
Thus, only the fuel is injected from the point C to the point D in FIG. 3 by the control of the governor 12.
[0028]
The increase amount of the fuel rack 2 corresponding to the water injection, that is, the amount c in FIG. 3 is arbitrarily adjusted by adjusting the protruding amount of the adjusting screw 11 attached to the piston 5a of the air cylinder 5. Can do.
[0029]
Also, the displacement start position for increasing the injection amount of the fuel rack 2 at the water injection start timing, that is, the position a in FIG. 3, and the displacement start position for decreasing the injection amount of the fuel rack 2 at the water injection end timing, that is, b in FIG. The position can be adjusted by changing the start timing and closing timing of the solenoid valve 8 of the pilot air pipe 10.
[0030]
That is, if the closing timing of the solenoid valve 8 is made earlier, a in FIG. 3 becomes smaller, the shift to the injection amount increase of the fuel rack 2 for water injection becomes faster, and if the opening timing of the solenoid valve 8 is made earlier. 3, the position b in FIG. 3 is reduced, and the release of the shift for water injection (reduction of the injection amount) is accelerated (the reverse is true when the opening / closing timing of the solenoid valve 8 is delayed).
[0031]
In addition, it can replace with the air cylinder 5 in this embodiment, and can also be set as the fluid pressure cylinder which uses other fluids, such as a hydraulic cylinder.
[0032]
【The invention's effect】
As described above, according to the present invention, the governor operating amount is controlled by controlling the supply and discharge of the working fluid to and from the fluid pressure cylinder connected to the fuel rack of the fuel injection pump via the adjusting screw. The injection amount can be increased / decreased without changing, and the injection amount can be increased by water injection within the maximum operating range corresponding to the maximum fuel injection amount of the governor.
[0033]
Further, the amount of increase in the injection amount can be arbitrarily adjusted by adjusting the protruding amount of the adjusting screw attached to the fluid pressure cylinder.
As a result, when the engine is stopped and during operation, switching between the fuel-only operation and the fuel / water injection operation can be easily realized without changing the governor performance.
[Brief description of the drawings]
FIG. 1 is a plan view of an essential part of a fuel injection pump control device for a diesel engine according to an embodiment of the present invention.
FIG. 2 is an enlarged structural view of the vicinity of a cylinder (fluid pressure cylinder) mounting portion in the embodiment of FIG. 1;
FIG. 3 is an operation explanatory diagram of the embodiment of FIG. 1;
FIG. 4 is a plan view of a main part of a conventional fuel injection pump control device.
5 is an operation explanatory diagram of the prior art of FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fuel injection pump 2 Fuel rack 3 Governor output link 4 Connection link 5 Air cylinder 5a Piston 5b 1st air chamber 5c 2nd air chamber 6 Spring 8 Solenoid valve 9 Main air pipe 10 Pilot air pipe 11 Adjustment screw 12 Governor

Claims (2)

In the fuel injection pump control device configured to transmit the output of the governor to the fuel rack for adjusting the fuel injection amount of the fuel injection pump via the governor output link,
The governor output link and the fuel rack are connected to the governor output link so as to be able to reciprocate, and the fuel rack is inserted between the connection link and the governor output link to reduce the injection amount. And a fluid pressure cylinder having a cylinder fixed to the governor output link, a piston reciprocating in the cylinder, and an adjusting screw fixed to an end of the piston. The movement of the governor output link in the fuel increasing direction can be transmitted to the fuel rack via the cylinder, piston and adjustment screw, and the piston and adjustment screw are displaced in the direction of compressing the spring. Configure the fuel rack to increase the injection amount,
The working fluid supply path to the fluid pressure cylinder is provided with an electromagnetic valve for controlling the supply and shutoff of the working fluid for moving the piston and the adjusting screw of the fluid pressure cylinder to the fluid pressure cylinder. A fuel injection pump control device. When the end face of the adjusting screw is brought into contact with the surface of the connecting link opposite to the spring, and the adjusting screw is protruded, the fuel rack moves in the direction of increasing the injection amount through the connecting link. The fuel injection pump control device according to claim 1, which is configured as follows.

Images