JPH09317500A - Injection quantity controller for fuel injector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To limit the maximum injection quantity for an engine in its lower speed range not to cause black smoke by providing a control means which outputs an operation signal directing the higher of lower speed range than a predetermined speed in response to the output signal from a speed sensor to thereby control a control rack stopper. SOLUTION: A speed sensor 8 detects the number of revolutions of an internal combustion engine. A control rack stopper 10 inhibits a control rack 1 of a fuel injector from being pushed out over its predetermined level in the direction to increase fuel A control means 7 outputs an operation signal directing the higher or lower speed range than a predetermined speed in response to the output signal from the speed sensor 8 to thereby control the stopper 10. As a result of which even by high-pressure injection, a sufficient power is ensured in the higher speed range as well as the generation of smoke is controlled in the lower speed range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection amount control device for a fuel injection device for a non-supercharged (naturally charged) internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, in a fuel injection device for an internal combustion engine, a control rack 1 for controlling the fuel injection amount is
Control rack 1 on the smoke limiter 9 shown in FIG.
One end abuts to limit the maximum movement amount and regulate the maximum injection amount. That is, in FIG. 8, the vertical axis indicates the position of the control rack 1 and the horizontal axis indicates the number of revolutions. The maximum position of the rack is limited to the position indicated by the symbol S ₀ by the smoke limiter and indicated by the symbol G ₀ . As described above, the governor pulls back the control rack when the rotational speed exceeds a predetermined value. In the smoke limiter 9, the spring B having a setting force pushes the push rod P to limit the maximum position of the control rack 1, and at the time of starting, the spring B can be pushed to increase the fuel amount. The range of fuel increase at the time of starting is indicated by the code D _{0 in the} low speed range (left in the figure).
Indicated by The control rack is controlled in this way, but as shown in FIG. 9, the fuel injection amount (vertical axis)
Since the volumetric efficiency of the plunger is not constant, it has a relationship as indicated by the symbol Q ₁ with respect to the rotation speed (horizontal axis).

On the other hand, the injection pressure of the fuel injection device has been increased to purify the exhaust gas, and the nozzle injection holes have been narrowed down. In such high-pressure injection, the injection amount reduction at high rotation side becomes large with respect to the same rack position, the code Q ₂ in FIG. 9
The characteristics are as shown in. Conventionally, to reduce the injection amount in such a high rotation range, as shown by reference numeral G ₁ in FIG. 10, an Angleich device for moving the rack to the injection amount increasing side at the time of high rotation by a governor has been used. However, the limit of the maximum rack position by the smoke limiter 9 must be set at a position beyond the rack position in the high rotation range by the Angleich device. Therefore, if the injection amount decrease at high rotation in high pressure injection is compensated for by the Angleich device,
The set position of the smoke limiter 9 becomes the high rack position as indicated by symbol S ₁ , and the fuel injection amount is indicated by the symbol Q _{2 in} FIG.
As shown in, the black smoke is generated in the low rotation speed range D _{2 because} it becomes excessive.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention relates to a fuel injection device for a non-supercharged internal combustion engine which performs control for limiting the maximum injection amount in the low rotation speed region in order to suppress the generation of black smoke in the low rotation speed region. An object is to provide a fuel injection amount control device.

[0005]

According to the present invention, the rotation speed sensor for detecting the rotation speed of the internal combustion engine and the control rack of the fuel injection device are prevented from being pushed in the fuel increasing direction beyond a predetermined amount. A control rack stopper
And a control means for controlling the stopper by outputting an operation signal in a high rotation range and a low rotation range above a predetermined rotation speed in response to an output signal of the rotation speed sensor.

According to the present invention, the control rack stopper is formed in a V shape as a whole, and one end of the control rack stopper is connected to the operating rod, and the operating rod is urged to one side. And a solenoid that actuates the actuation rod against the spring when energized.

Alternatively, the control rack stopper communicates with an air source and the air source via an air pipe, and a diaphragm chamber having one surface formed of a diaphragm, and an operating member connected to the diaphragm of the diaphragm chamber. It has a rod, a spring for urging the operating rod to one side, and an on-off valve which is interposed in the air pipe and is opened and closed by an output signal of the control means.

Alternatively, the control rack stopper is composed of a piston cylinder unit that expands and contracts according to the output of the control means.

Since the present invention is constituted as described above, the control means outputs an operation signal in a high rotation range and a low rotation range above a predetermined rotation speed according to the output signal of the rotation speed sensor,
This signal causes a stopper for the control rack, for example, a solenoid in the second invention, to move the operating rod up and down against the spring force to rotate the V-shaped link, and at its tip end, the maximum stop position of the control rack is set. It is limited to two parts, a high speed range and a low speed range.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a control rack 1 slidably provided on an injection pump main body (not shown) has an end protruding from the injection pump main body, and one end thereof is locked by a control rack stopper 10 described later. The protruding portion 1a is formed. This control rack 1
A solenoid 2 is provided above the protruding portion 1a, and an operating rod 3 which is operated by the solenoid 2 is provided downwardly biased by a spring 4. Then, a V-shaped link 5 rotatably supported at a fulcrum A is provided, one end 5a thereof is connected to one end of the operating rod 3, and the other end 5b thereof is provided with a protrusion 1 of the control rack 1.
The control rack 1 is arranged so as to lock a and stop at a predetermined position. The solenoid 2, the operating rod 3, the spring 4, and the V-shaped link 5 constitute a stopper 10 for a control rack.

The solenoid 2 responds to the output signal of the rotation speed sensor 8 for detecting the rotation speed of the internal combustion engine, turns off the solenoid in a rotation speed range higher than a predetermined rotation speed N _E , and lowers the rotation speed below the predetermined rotation speed N _E. In the rotation range, the control means 7 for turning on the solenoid is connected.

Next, the operation of this embodiment will be described.
In the flowchart of FIG. 4, the rotation speed sensor 8 reads the rotation speed N _E into the control means 7 (Step 1),
It is compared with the predetermined rotation speed N (Step 2). When the rotational speed is lower than the predetermined speed N, the solenoid 2 is energized (Step 3),
The operating rod 3 is pulled up against the spring 4, the V-shaped link 5 rotates, and the projection 1a of the rack 1 abuts against the tip 5b of the V-shaped link 5 at the first stop position S _L. Since they are in contact with each other, the amount of movement of the rack 1 in the injection amount increasing direction (direction of arrow F) is limited. If the rotation speed N _E is equal to or higher than the predetermined rotation speed N, the solenoid 2 is turned off (Step
4), the operating rod 3 is pulled down by the spring 4, and the tip portion 5 of the V-shaped link 5 as shown by the broken line in FIG.
b moves to the second stop position S _H. The second
The stop position may not be in contact with the V-shaped link 5 and may be limited by another rack stop or a stop limiter.

Therefore, as shown in FIG. 5, the control rack 1 can be moved in the direction of increasing fuel up to S _{H in} the high rotation range, and is limited by S _L in the low rotation range. Then, as shown by the curve G, since it is controlled by the governor, the output in the high rotation speed range can be secured (FIG. 6), while the portion indicated by the reference numeral D in the low rotation speed region is cut, so that the black smoke emission Is prevented.

FIG. 2 shows a control rack stopper 20 of the third invention. An air reservoir 13 as an air source is provided, and a diaphragm chamber 11 having a diaphragm 12 instead of the solenoid 2 is provided at the position of the solenoid 2 of the second invention. And
An air reservoir 13 is provided in the air chamber below the diaphragm 12.
An air pipe 15 having an opening / closing valve 14 is communicated therewith. The open / close valve 15 is opened / closed by an output signal of the control means 7. An operating rod 3A is connected to the diaphragm 12 and is biased upward by a spring 4A.

Therefore, the control means 7 controls the opening / closing valve 15 by the signal of the rotation speed sensor 8, and at a predetermined rotation speed N or less, the opening / closing valve 15 is opened and air is sent from the air reservoir 13 to the diaphragm chamber 11. , V-shaped links 5 limit the control rack 1 at the first stop position S _L. Then, the predetermined rotational speed or more N, the air in the diaphragm chamber 11 is opened, the operating rod 3A is pulled by the spring 4A, V-shaped link 5 is rotated, the control rack 1 to a second stop position S _H Can be moved.

FIG. 3 shows a piston / cylinder unit 30 which is a stopper for a control rack of the fourth invention. In this piston cylinder unit 30, the stopper portion at the tip can be extended / contracted, and the control means 7 outputs and controls it by the signal of the rotation speed sensor 8. At the time of extension, it abuts on the protrusion 1a of the control rack 1 and the rack 1 Limit the amount of movement of.

[0018]

Since the present invention is configured as described above, it has the following excellent effects. (1) Even in high-pressure injection, the output in the high rotation range can be secured, and the smoke in the low rotation range can be suppressed. (2) A large number of standard mechanical governor or boost compensator parts for a supercharged engine can be used, which is inexpensive and highly reliable.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of the present invention.

FIG. 2 is a partial sectional view showing an embodiment of a third invention.

FIG. 3 is a partial sectional view showing an embodiment of a fourth invention.

FIG. 4 is a flowchart showing the operation of the present invention.

FIG. 5 is a diagram showing a relationship between rack positions according to the present invention.

FIG. 6 is a diagram showing an injection amount characteristic according to the present invention.

FIG. 7 is a sectional view of a conventional smoke limiter.

FIG. 8 is a diagram showing a conventional rack position relationship.

9 is a diagram showing an injection amount characteristic according to FIG.

FIG. 10 is a diagram showing a relationship between rack positions when high-pressure injection is applied to a conventional control device.

FIG. 11 is a diagram showing an injection amount characteristic according to FIG.

[Explanation of symbols]

 1 ... Control rack 2 ... Solenoid 3, 3A ... Actuating rod 4, 4A ... Spring 5 ... V-shaped link 7 ... Control means 8 ... Rotation speed sensor 9. ..Smoke limiters 10, 20 ... Control rack stopper 11 ... Diaphragm chamber 12 ... Diaphragm 13 ... Air reservoir 14 ... Open / close valve 15 ... Air piping 30 ... Piston cylinder unit

Claims (4)

[Claims] 1. A rotation speed sensor for detecting a rotation speed of an internal combustion engine, a control rack stopper for preventing a control rack of a fuel injection device from being pushed in a fuel increasing direction beyond a predetermined amount, and the rotation speed. A fuel injection amount control device for a fuel injection device, comprising: a control unit that responds to an output signal of a sensor and outputs an operation signal in a high rotation range and a low rotation range than a predetermined rotation speed to control the stopper. . 2. The control rack stopper is formed in a V shape as a whole, and one end of which is connected to an operation rod, a V shape link, a spring for urging the operation rod to one side, and an energization state. A solenoid for actuating the actuating rod against the spring.
The fuel injection amount control device of the fuel injection device according to. 3. The stopper for the control rack,
An air source, a diaphragm chamber communicating with the air source through an air pipe and having a diaphragm on one surface, an operating rod connected to the diaphragm in the diaphragm chamber, and the operating rod urged to one side. The fuel injection amount control device for a fuel injection device according to claim 1, further comprising a spring that opens, and an on-off valve that is interposed in the air pipe and that opens and closes according to an output signal of the control means. 4. The control rack stopper comprises:
The fuel injection amount control device for a fuel injection device according to claim 1, comprising a piston cylinder unit that expands and contracts according to the output of the control means.