JPH09287484A - Centrifugal governor for diesel engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the emission of black smoke from an engine at its rapidly- accelerated running as well as prevent an engine stall caused when the engine is shifted from its low idling state to its crawlingly-running range. SOLUTION: A rack pin 2 of a fuel injection pump 1 is interlocked with a governor weight 6 through a governor lever 3 which is connected to a governor lever 5 through a governor spring 4. Thus the rack pin 2 is elastically pressed by the governor spring 4 toward the fuel-increasing side R and is pressed by the governor weight 6 toward the fuel-decreasing side L, to limit the fuel quantity injected in the medium and low speed running ranges of an engine at torques not higher than its maximum torque by a fuel limiter 20 for rapid acceleration. In addition, there are provide a detector 11 for detecting the engine is in its crawlingly-running range to output a driving signal K, and a fuel- increasing means 12 for moving the rack pin 2 toward the fuel-increasing side R on the basis of the driving signal K.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal type governor for a diesel engine, and more particularly to reducing acceleration smoke in a medium to low speed rotation range below the maximum torque of the engine E.
The present invention relates to a technology for preventing engine stall in an ultra-low speed rotation range.

[0002]

[Technical background] Centrifugal governors for diesel engines are
For example, as shown in FIG. 5, the rack pin 2 of the fuel injection pump 1 is connected to the output portion of the first lever 3a that constitutes the governor lever 3, and the governor weight 6 is attached to the input portion of the first lever 3a via the governor sleeve 15. Connect, second
Governor spring 4 to lever 3b
While the governor spring 4 presses the fuel increase side R, the governor weight 6 presses the first lever 3a toward the fuel decrease side L and the second lever 3b uses the fuel limit pin 9 for the full load ( 4/4) It is configured such that it can be received at an equivalent position, and a torque increasing device 16 is interposed between the first lever 3a and the second lever 3b, and the torque increasing device 16 causes the first lever 3a to fully load (4 / 4) It is configured to be swingable from a corresponding position to a position corresponding to the maximum torque (Tr), and the injected fuel in the medium to low speed rotation range equal to or less than the maximum torque (Tr) is suppressed by the fuel limiting device (20) during sudden acceleration. It is configured.

Reference numeral 2a in FIG. 5 is a metering rack for the fuel injection pump 1, 7 is a high idle spring for suppressing rapid movement of the first lever 3a to the reducing side L, and 17 is a high idle spring 7. An adjusting bolt for adjusting the spring force, 8 is a start / start spring, and 19 is a governor shaft. The fuel limiting pin 9 and the adjusting bolt 1
7 are fixed so that they can pass through the machine wall and be adjusted back and forth.

By the way, in a diesel engine, black smoke is generated during a sudden acceleration operation. This black smoke is shown in Figure 2.
As indicated by the solid line in the figure, the speed control lever 5 is moved from the low idle rotation position L (for example, a position corresponding to 1000 rpm) to the high idle rotation position H (for example, a position corresponding to 3600 rpm).
This black smoke is generated when the fuel injection pump 1 is rapidly accelerated because the tension of the governor spring 4 immediately increases.
The rack pin 2 overshoots, but there is a time delay in the increase in the engine speed, so there is a time delay in increasing the intake air amount of the engine until the tension of the governor spring 4 is balanced with the governor force G. It occurs because an excessive amount of fuel is supplied with respect to the intake amount.

The rack pin 2 of the fuel injection pump 1 that overshoots is positioned at a position corresponding to the maximum torque (Tr) of the engine (around 2000 rpm) until the governor force G balances with the tension of the governor spring 4, and then in FIG. As indicated by the solid line, the position reaches the no-load (0/4) position as the engine speed increases. That is, the fuel injection amount Q in the medium to low speed rotation range (Nt) equal to or lower than the maximum torque (Tr) of the engine influences the black smoke during the sudden acceleration operation.

[0006]

2. Description of the Related Art A fuel injection pump having a boost compensator and a CTD (Compact Timing Device) has been conventionally used as a means for preventing the generation of black smoke during sudden acceleration (hereinafter, these are generically referred to as sudden acceleration). Fuel limiter) is known.

The boost compensator 20 shown in FIG.
As shown in FIG. 3, a diaphragm 23 that partitions the interior of the casing 21 into a primary chamber 22a and a secondary chamber 22b, an output rod 25 that interlocks with the diaphragm 23, and the output rod 25 via the diaphragm 23 to the primary chamber 22a side. When the engine is suddenly accelerated, there is a time delay in the increase of the engine speed and a supercharging operation. Even if there is a delay in the rise of the supercharging pressure P of the container 30, the biasing force of the spring 24 causes the abutment tool 26 to move to the first lever 3
It is brought into contact with a to limit its sudden acceleration oscillation and limit the fuel injection amount Q that is about to be excessively supplied.

In addition, CTD (Compact Timing Devi)
CE has a maximum torque (Tr)
By suppressing the injected fuel in the medium to low speed rotation range (Nt) below, it is configured to prevent the generation of black smoke during the sudden acceleration operation. 2 shows the engine rotation speed (r
pm) and the position of the rack pin (fuel injection amount Q), the two-dot chain line (BC) in the figure shows the behavior of the rack pin when the boost compensator is provided, and the one-dot chain line (CTD) is The solid line shows the behavior of the rack pin when the fuel injection pump having the CTD is built in, and the solid line shows the behavior of the rack pin when neither of the above is provided.

[0009]

However, when the fuel injection pump incorporating the boost compensator or the CTD is adopted, the engine is not subjected to a load due to the turning operation of the tractor, for example, in a low idle rotation state (for example, 1000 rpm). Therefore, when the rotation speed further decreases, for example, below 1000 rpm, the fuel injection amount Q further decreases and the torque is insufficient in the rotation range Ns from the low idle rotation state to the engine stall (hereinafter, referred to as an ultra-low speed rotation range). And then (at 850 rpm, for example)
There is a problem of inducing stalling. The present invention has been made in consideration of such circumstances, and when the engine shifts from the low idle rotation state to the ultra-low speed rotation range Ns while preventing the generation of black smoke during the sudden acceleration operation, the engine stall The technical issue is to prevent the induction.

[0010]

In order to solve the above problems, the present invention is configured as follows. That is, the governor weight 6 is interlockingly connected to the rack pin 2 of the fuel injection pump 1 via the governor lever 3, the speed governing lever 5 is connected to the governor lever 3 via the governor spring 4, and the rack pin 2 is connected to the governor spring 4 by the governor spring 4. While the pressure is increased to the fuel increase side R, the governor force G of the governor weight 6 pushes to the fuel decrease side L, and the medium to low speed rotation range (N) is equal to or less than the maximum torque (Tr) of the engine.
In the centrifugal governor of a diesel engine configured to suppress the injected fuel at t) by the fuel limiting device 20 at the time of sudden acceleration, it is detected that the engine E is in the ultra-low speed rotation range Ns and the drive signal K is output. And a fuel increasing means 12 for moving the rack pin 3 to the fuel increasing side R based on the drive signal K.

[0011]

According to the present invention, in addition to the fuel limiting device 20 for sudden acceleration, the detector 11 for detecting that the engine is in the ultra-low speed rotation range Ns and outputting the drive signal K, and the drive signal described above. Since the fuel quantity increasing means 12 for moving the rack pin 3 to the fuel quantity increasing side R on the basis of K is additionally provided, when the speed adjusting lever 5 is rapidly accelerated to shift the engine from the low idle rotation state to the high idle rotation state, During the rapid acceleration, the fuel limiting device 20 operates to suppress the excessive supply of fuel. This prevents the generation of black smoke during sudden acceleration.

On the other hand, when the engine is loaded in the low idle rotation state and the rotation speed further decreases, the detector 11 detects that the engine is in the ultra-low speed rotation range Ns and outputs the drive signal K. Based on this drive signal K, the fuel amount increasing means 12 moves the rack pin 3 to the fuel amount increasing side R. As a result, the fuel injection amount Q increases in the ultra-low speed rotation range Ns, and the induction of engine stall is prevented. Even if the fuel injection amount Q increases in the ultra-low speed rotation range Ns, black smoke does not occur.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a centrifugal governor according to a first embodiment of the present invention. This centrifugal governor has the same basic structure as the conventional example (FIG. 5). That is, the rack pin 2 of the fuel injection pump 1 is elastically pressed to the fuel increasing side R by the governor spring 4 via the governor lever 3, while the governor weight 6 is pressed to the fuel decreasing side L, and the governor lever 3 is configured to be pressed. A fuel limiting device 20 for sudden acceleration is provided to face the above.

The governor lever 3 comprises a first lever 3a and a second lever 3b. The governor weight 6 is interlockingly connected to the input part of the first lever 3a via a governor sleeve 15, and the rack pin 2 is connected to the output part. The start spring 8 is interlockingly connected, the speed control lever 5 is connected to the second lever 3b through the governor spring 4, and
The fuel limiting pin 29 can receive the lever 3b at a position corresponding to the full load (4/4). Also, the first
A torque increasing device 16 is interposed between the lever 3a and the second lever 3b, and the torque increasing device 16 allows the first
The lever 3a is configured to be movable from a position corresponding to the full load (4/4) to a position corresponding to the maximum torque (Tr), and is configured to increase the fuel amount against the overload applied to the engine to exhibit tenacity. .

The fuel control device for sudden acceleration 20 has a structure similar to that of the boost compensator shown in FIG. 5, and when the engine is rapidly accelerated, there is a time delay in the increase of the engine speed and the supercharger of the supercharger. Even if there is a delay in the rise of the supercharging pressure P, the biasing force of the spring 24 causes the abutment device 26 to abut against the first lever 3a to limit its sudden acceleration and oscillation, and fuel that is about to be supplied excessively. It is configured to limit the injection amount Q. In addition, among the reference numerals in FIG. 1, the reference numerals described in FIG. 5 are given the same reference numerals, and overlapping description will be omitted.

In the present invention, as shown in FIG. 1, in addition to the fuel limiting device 20 at the time of sudden acceleration, it is detected that the engine is in the ultra-low speed rotation range Ns shown in FIG. 2 and the drive signal K is output. A detector 11 and a fuel amount increasing means 12 for moving the rack pin 3 to the fuel amount increasing side R based on the drive signal K are provided. The characteristic structure of the first embodiment will be described below.

This centrifugal governor corresponds to claim 2. The detector 11 for detecting that the engine is in the ultra-low speed rotation range Ns is, for example, a sensor for detecting the engine speed or negative pressure pulsation. Used. Further, as the fuel amount increasing means 12, an electromagnetic solenoid 15 that causes the high idle spring 7 to project to the fuel amount increasing side R when the engine is in the ultra-low speed rotation range Ns is used. According to this embodiment, when the engine is loaded in the low idle rotation state and the rotation speed further decreases, the rack pin 3 is moved to the fuel increase side R via the high idle spring 7 and the fuel injection amount Q is increased. Is increased (see symbol B in FIG. 2) to prevent the engine stall.

FIG. 3 is a schematic view of a centrifugal governor according to the second embodiment of the present invention. This centrifugal governor is claim 3.
As the fuel amount increasing means 12, an electromagnetic solenoid 15 is used which pulls the start spring 8 toward the fuel amount increasing side R to increase the tension thereof when the engine is in the ultra-low speed rotation range Ns. According to this embodiment,
When the rotation speed further decreases from the low idle rotation state, the start spring 8 is pulled to move the rack pin 3 to the fuel increase side R to increase the fuel injection amount Q and prevent the engine stall.

FIG. 4 is a schematic view of a centrifugal governor according to the third embodiment of the present invention. This centrifugal governor is claim 4.
It is particularly useful when a fuel injection pump with a built-in CTD is adopted. As the detector 11 that detects that the engine is in the ultra-low speed rotation range Ns, a sensor that detects negative pressure pulsation of the engine is used,
As the fuel amount increasing means 12, an electromagnetic solenoid 15 for retracting the fuel limiting pin 9 to the fuel amount increasing side R is used.

According to this embodiment, when the number of revolutions further decreases from the low idle revolution state, the fuel limiting pin 9 is retracted to the fuel increasing side R so that the tensions of the governor spring 4 and the start spring 8 are applied. The rack pin 3 is moved to the fuel increase side R to increase the fuel injection amount Q.
(Refer to symbol C in FIG. 2), preventing the engine stall. In each of the above-mentioned embodiments, an electromagnetic solenoid is used as the actuator, but an actuator that operates with compressed air may be used instead.

[Brief description of drawings]

FIG. 1 is a schematic view of a centrifugal governor according to a first embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the engine speed (rpm) and the position of a rack pin of the fuel injection pump (fuel injection amount Q).

FIG. 3 is a view corresponding to FIG. 1 of a centrifugal governor according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram of a centrifugal governor according to a third embodiment of the present invention.

FIG. 5 is a schematic diagram of a centrifugal governor according to a conventional example.

[Explanation of symbols]

1 ... Fuel injection pump, 2 ... Rack pin, 3 ... Governor lever, 4 ... Governor spring, 5 ... Governor lever, 6 ... Governor weight, 7 ... High idle spring, 8 ... Start spring, 9 ... Fuel restriction pin, 11 ... Detection Bowl, 12
... Fuel increasing means, 15 ... Actuator (electromagnetic solenoid), 20 ... Fuel limiting device for sudden acceleration, E ... Engine, G
... Governor force, R ... Fuel increase side, L ... Fuel decrease side, K ... Drive signal, Ns ... Ultra low speed rotation range, Nt ... Medium / low speed rotation range, T
r ... maximum torque.

Claims (4)

[Claims] 1. A governor weight (6) is interlockingly connected to a rack pin (2) of a fuel injection pump (1) via a governor lever (3), and the governor lever (3) is adjusted via a governor spring (4). While the speed lever (5) is connected and the rack pin (2) is elastically pressed by the governor spring (4) to the fuel increase side (R), the governor force (G) of the governor weight (6) reduces fuel consumption. The fuel limiting device (2) is configured to be pushed to the side (L), and the injected fuel in the medium to low speed rotation range (Nt) equal to or less than the maximum torque (Tr) of the engine (E) is to be rapidly accelerated.
In a centrifugal governor for a diesel engine, which is configured to suppress in 0), a detector (11) that detects that the engine (E) is in an ultra-low speed rotation range (Ns) and outputs a drive signal (K) And a fuel amount increasing means (12) for moving the rack pin (3) to the fuel amount increasing side (R) based on the drive signal (K), the centrifugal governor for a diesel engine. 2. The centrifugal governor for a diesel engine according to claim 1, wherein the fuel amount increasing means (12) is provided.
Is a centrifugal governor for a diesel engine, characterized in that the actuator (15) causes the high idle spring (7) to project toward the fuel amount increasing side (R). 3. The centrifugal governor for a diesel engine according to claim 1, wherein the fuel amount increasing means (12) is provided.
Is a centrifugal governor for a diesel engine, characterized in that the actuator (15) pulls the start spring (8) toward the fuel increase side (R) to increase the tension thereof. 4. The centrifugal governor for a diesel engine according to claim 1, wherein the fuel amount increasing means (12) is provided.
The fuel limiting pin (9) by the actuator (15)
A centrifugal governor for a diesel engine, which is configured to be retracted to the fuel increase side (R).