JPH1122491A - Centrifugal governor for diesel engine - Google Patents

Abstract

(57) [Problem] To reduce a governor difference with a simple mechanical configuration in a centrifugal governor device. SOLUTION: One end side of a governor lever 2 is pivotably supported on a base shaft 3 so as to apply a pulling force of a governor force 6 and a governor spring 7 to the governor lever 2.
The governor spring 7 is operatively connected to the speed control lever 8, and an actuator 17 is engaged with the tip of the speed control lever 8. When it is determined by the limit switch 20 that the control rack 5 is at a position lower than the predetermined low load position, the operating portion 18 of the actuator 17
To rotate the governing lever 8 to a position where it contacts the low-speed rotation speed setting limit bolt 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal governor for a diesel engine, and more particularly to a centrifugal governor capable of reducing a governor difference with a simple structure.

[0002]

2. Description of the Related Art In a diesel engine equipped with a centrifugal governor, when the engine is operated at the full load maximum rotation speed Nf and the load of the engine is reduced for some reason, the centrifugal governor is operated. It functions to reduce the injection amount in order to prevent the rotation speed fluctuation, but this function has a limit, and the rotation speed increases to some extent.

FIG. 4 shows the engine speed on the horizontal axis and the fuel injection amount on the vertical axis. The maximum engine speed Na in the full load state (4/4) and the maximum engine speed in the no load state (0/4) are shown. FIG. 9 is a diagram illustrating a difference d between the rotation speeds Nf, and the smaller the difference d, the higher the performance of the governor device. In addition, the speed fluctuation rate K indicates the rotational stability performance of the governor device with respect to the load.
(%) Is defined, and the speed fluctuation rate K is given by K = (Nf-Na) / Nf. The speed variation rate K is also called a governor difference. Due to the nature of the engine, the smaller the governor difference, the better. However, in the case of an engine mounted on a working machine that allows a certain degree of change in the number of revolutions, the demand for reducing the governor difference is not so strong.

[0004]

However, in an engine generator or the like, since the power generation frequency changes when the engine speed changes, the rotation stability against load fluctuation is strictly required.

A conventional method adopted to maintain a high rotational stability of the engine even when such a load fluctuation occurs is, for example, as follows. First, a first method is a method of setting a governor device so as to reduce a governor difference. For example, a governor lever is interlockedly connected to a control rack of a fuel injection pump, and a control rack is biased to a fuel increasing side (R) by a governor spring via a governor lever, whereas a governor force is biased to a fuel decreasing side by a governor force. In the centrifugal governor device of the system, a weak spring is adopted by reducing the hook coefficient of a governor spring that pulls fuel toward the fuel reduction side. However, this method has a problem that the operation of the centrifugal governor device becomes unstable and hunting easily occurs.

A second method is to reduce the governor difference by using an electronic governor device. According to the method using the electronic governor, it is possible to make the governor difference practically zero. However, expensive central processing units (CP
U), it is necessary to use a sensor or the like, and there is a problem that the manufacturing cost of the engine increases. In addition, when an engine for a working machine that is often used under severe conditions such as continuous operation for a long time under extremely low temperature or high temperature environment conditions is considered, the environmental stability of the CPU and the sensor remains uneasy.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a centrifugal governor for a diesel engine which can solve the above problems. An example of a specific purpose is as follows. (a) The difference in governor is reduced with a simple configuration, while taking advantage of the low cost and good environmental stability of the centrifugal governor. The problems of the invention other than those described above and the means for solving the problems will be described in detail in the section of the means for solving the problems, the operation, and the embodiments of the invention described later.

[0008]

Means for Solving the Problems The first invention is, for example,
Referring to FIGS. 1 to 3, the governor lever 2 is connected to the control rack 5 of the fuel injection pump 4 in an interlocking manner.
While the control rack 5 is urged toward the fuel increasing side R by the governor spring 7 via the governor lever 2,
The governor force 6 urges the governor spring 7 toward the fuel reduction side L and operates the speed control lever 8 connected to the governor spring 7 so that the tension of the governor spring 7 can be adjusted and operated.
Further, the urging means 14 for urging the speed control lever 8 to a predetermined high-speed position, the driving means 16 for driving the speed control lever 8 to the low-speed rotation side, and whether the control rack 5 is at a position lower than the predetermined low-load position. Position determining means 19 for determining whether or not the control rack 5 is moved to the predetermined low load position by the position determining means 19 when the engine in which the governing lever 8 is set to the predetermined high-speed position by the urging means 14 in advance is operated. In response to determining that it is at a higher load position,
The urging means 14 is configured to maintain the governing lever 8 at the predetermined high-speed position, and the urging is performed in response to the position discriminating means 19 determining that the control rack 5 is at or below the predetermined low load position. The speed control lever 8 is operated to a predetermined low speed position by the driving means 16 against the urging force of the means 14, and the predetermined low speed position is maintained.

The second invention will be described with reference to, for example, FIGS. 1 to 3. The fuel metering device 33 of the fuel injection pump 4 is urged toward the fuel increasing side R by the governor spring 7 via the governor lever 2. On the other hand, the governor force 6 urges the governor spring 7 toward the fuel reduction side L, and the tension of the governor spring 7 can be adjusted and operated by moving the position of the governing spring 9 connected to the governor spring 7. Position discriminating means 1 for discriminating whether or not the metering tool 33 is at or below a predetermined low load position.
9 and that the position determining means 19 has determined that the fuel metering device 33 is at a position of a load larger than the predetermined low load position during operation of the engine in which the speed adjusting operation device 9 is set at the predetermined high speed position in advance. , The speed control device 9 is configured to maintain a predetermined high-speed position,
9, in response to the determination that the fuel metering device 33 is at a position equal to or lower than the predetermined low load position, the speed adjusting operation device 9 is operated to the predetermined low speed position, and the predetermined low speed position is maintained. It is characterized by.

[0010]

According to the first aspect of the present invention, when the engine is running, the control rack 5 is detected by the position determining means 19.
Is determined to be at a load position larger than the predetermined low load position, the urging means 14 keeps the governing lever 8 at the predetermined high speed position, and the position determination means 19 causes the control rack 5 to move the control rack 5 to the predetermined low load position. In response to the determination that the position is equal to or lower than the position, the speed adjusting lever 8 is operated to the predetermined low speed position by the driving means 16 against the urging force of the urging means 14, and the predetermined low speed position is maintained. Thus, in the no-load state (0/4), the governing lever 8 is at the predetermined low-speed position, and as shown in FIG. 2, the no-load state (0/4).
Can be reduced as compared with the conventional case (see Nf in FIG. 2), and the full load state (4
In the case of (/ 4), the governing lever 8 is at the predetermined high-speed position, and the high-speed rotation speed Na 'in the full load state (4/4) is reduced to the same size as the conventional one (see Na in FIG. 4). can do. Therefore, (Nf′−Na ′) / Nf ′ can be set smaller than the conventional (Nf−Na) / Nf. Even in this case, the strength of the governor spring 7 can be increased to the extent that hunting does not occur, and the governor difference can be reduced while preventing unstable governor operation.

According to the second aspect of the present invention, during the operation of the engine, in response to the determination by the position determining means 19 that the fuel metering device 33 is at a position with a load greater than the predetermined low load position, the speed control device is operated. 9 maintains the predetermined high-speed position, and in response to the position determining means 19 determining that the fuel metering device 33 is at a position equal to or less than the predetermined low-load position, the speed-control operating device 9 is operated to the predetermined low-speed position; The predetermined low-speed position is maintained. Thus, in the no-load state (0/4), the governing lever 8 is at the predetermined low-speed position, and the high-speed rotation speed Nf 'in the no-load state (0/4) is reduced as shown in FIG. It can be made smaller than in the conventional case (see Nf in FIG. 2), and at full load (4/4), the speed control lever 8
Is in the predetermined high-speed position, and is fully loaded (4/4)
The high-speed rotation speed Na 'is set to the same size as the conventional one (Na in FIG. 4).
See). Therefore, (Nf′−N
a ′) / Nf ′ can be set smaller than the conventional (Nf−Na) / Nf. Even in this case, the strength of the governor spring 7 can be increased to the extent that hunting does not occur, and the governor difference can be reduced while preventing unstable governor operation.

[0012]

As described above, the first and second inventions have the following specific effects (a) and (b). (A) The basic governor control operation can adopt the operation of the centrifugal governor, and the governor difference is reduced by moving the governor lever or governor during engine operation.
The moving mechanism can be implemented with a simple configuration. (B) Since the governor difference is reduced by moving the speed control lever or speed control device, a complicated circuit is unnecessary,
It is cheaper and has better environmental stability than an electronic governor using a CPU.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram illustrating a centrifugal governor device for a diesel engine according to the present invention, and FIGS. 2A and 2B are diagrams illustrating the operation of the centrifugal governor device.

The centrifugal governor 1 shown in FIG. 1 is configured as follows. First, one end of the governor lever 2 is pivotally supported on the base shaft 3 so as to be swingable, and the other end is connected to the fuel injection pump 4.
And linked to the control rack 5. A governor force 6 is applied to the governor lever 2 by rotation of a governor weight (not shown), and the governor force 6 biases the control rack 5 to the fuel reduction side L. On the other hand, one end of a governor spring 7 is fixed to the governor lever 2, and the other end of the governor spring 7 is interlocked with a speed control lever 8 of the engine. The governor spring 7 pulls the control rack 5
To the fuel increasing side R. Note that the control rack 5 is illustrated as a fuel metering tool 33.

A speed control lever 8 as a speed control operating tool 9 is pivotally supported by a base shaft 35 so as to be swingable. The range of rotation of the speed control lever 8 is determined by a predetermined high-speed position setting tool 10 and a predetermined low-speed position setting. It is specified by the tool 11. In the embodiment shown in FIG. 1, the predetermined high-speed position setting tool 10 and the predetermined low-speed position setting tool 11 are configured by a high-speed rotation speed setting limit bolt 12 and a low-speed rotation speed setting limit bolt 13, respectively.

At the leading end of the speed control lever 8, a speed control lever 8
A tension spring 15 as the urging means 14 for pulling the motor toward the high-speed side is locked, and the tension of the tension spring 15 causes the speed control lever 8 to abut against the high-speed rotation speed setting limit bolt 12 during engine operation. (That is, a predetermined high-speed position).

An actuator 17 as the driving means 16 is engaged with the distal end of the speed control lever 8, and when the actuator 17 is turned on, the operating portion 18 of the actuator 17 is turned on. The distal end side is pushed to overcome the tension of the tension spring 15 and rotate the speed control lever 8 to a state where it comes into contact with the low-speed rotation setting limit bolt 13 (that is, a predetermined low-speed position).

Control rack 5 for fuel injection pump 4
A limit switch 20 as the position determining means 19 is provided at the left end 5a on the decreasing side. The limit switch 20 has a configuration in which a conductive contact member 22 is connected to a 12 V power supply via a relay coil 21. A conductive spring 23 is provided at the tip of the conductive abutting tool 22. When the control rack 5 is located at a load position equal to or lower than a predetermined low load position, the conductive spring 23 maintains the contact state when the control rack 5 moves. It is configured so as to follow while performing. When the control rack 5 is located at a load position higher than the predetermined low load position, the tip of the conductive spring 23 is separated from the left end 5 a of the control rack 5.

The conductive abutment 22 is disposed on a predetermined wall of the engine with an insulator 24 interposed therebetween. When the conductive spring 23 of the conductive abutment 22 is in contact with the control rack 5, a voltage of 12 V is applied. A current flows from the power supply to the relay coil 21, the conductive contact member 22, the control rack 5, and the engine base, and the switch contact 25 of the relay coil 21 is turned on.
(Short-circuit state). Since the earth contact 26 of the actuator 17 is connected to the switch contact 25,
When the control rack 5 moves below the predetermined low-load position, the actuator 17 is turned on, and the operating portion 18 projects as indicated by the imaginary line 34, so that the actuator 17 is adjusted to a position where it comes into contact with the low-speed rotation speed setting limit bolt 13. The speed lever 8 is rotated. The centrifugal governor device is mounted on a working machine, such as an engine generator, on the premise that the engine is operated at a constant rotational speed. In the case of such a working machine, even if the load state of the engine is detected only by the position of the control rack, the detection accuracy does not deteriorate as much as a problem in practical use.

The operation of the centrifugal governor for a diesel engine having the above configuration will be described with reference to FIG. FIGS. 2A and 2B are explanatory diagrams of the operation of the governor in which the horizontal axis indicates the engine speed and the vertical axis indicates the fuel injection amount of the fuel injection pump, and corresponds to FIG.

2A and 2B, a characteristic curve 27 and a characteristic curve 28 respectively show a change in rotation speed due to a change in load. Here, a characteristic curve 27 shows a characteristic in a state in which the speed control lever 8 is in contact with the high-speed rotation speed setting limit bolt 12, and a characteristic curve 28 is a condition in which the speed control lever 8 is in contact with the low-speed rotation speed setting limit bolt 13. The characteristics in the state shown in FIG. In the characteristic curve 27, for example, no load (0/4)
, The engine speed Nf is 4000 rpm,
Engine speed Na at full load (4/4) is 3600
At rpm, the governor difference is 400/4000, which is as high as 10%. On the other hand, according to the characteristic curve 28, when the speed control lever 8 is in contact with the low-speed rotation speed setting limit bolt 13, the rotation speed Nf 'of the no-load (0/4) engine is 3700 rpm.

In order to reduce the governor difference, in the present embodiment, the actuator 17 is driven so as to shift from the characteristic curve 27 to the characteristic curve 28 when the load position becomes equal to or less than the predetermined low load position P. Then, the setting position of the governing lever 8 is changed from the predetermined high-speed position to the predetermined low-speed position. A characteristic curve when the actuator 17 is driven instantaneously is a first actual operation curve 29 indicated by a thick line in FIG. 2A, and a characteristic curve when the actuator 17 is gradually driven is shown in FIG. 7B is a second actual operation curve 30 indicated by a bold line in FIG. When the engine is operated as indicated by the first actual operation curve 29 and the second actual operation curve 30 in this manner, the high-speed rotation speed Nf ′ of the engine at the time of no load (0/4).
Is 3700 rpm, and the engine high-speed rotation speed Na '(same as Na in FIG. 4) at full load (4/4) is 3600 rpm.
pm, and the governor difference is 100/3700,
% To about 2.7%.

The first actual operation curve 29 as shown in FIG. 2A is obtained by forming the actuator 17 shown in FIG. 1 with an on / off type solenoid, and when the operating portion 18 is protruded and when it is retracted. It can be configured by taking only the two states in the case. This configuration has the advantage that it can be implemented at low cost. A second actual operation curve 30 as shown in FIG. 2B employs an actuator 17 in which the amount of protrusion of the operating portion 18 can be continuously changed. For example, when the limit switch 20 is turned on, 1
It can be realized with a configuration in which the amount of protrusion is gradually changed with time by a timer (not shown) or the like after the 2 V voltage is supplied. With such a configuration, it is possible to prevent the fuel injection amount from changing abruptly in a short time, and to realize a smooth operation.

FIG. 3 is a schematic configuration diagram for explaining a second embodiment of the present invention. The second embodiment is different from the first embodiment in that the governing spring 8 is not provided and the other end of the governor spring 7 is directly connected to the operating portion 1 of the actuator 17.
This is the point connected to No. 8. Note that, in the second embodiment, the above-mentioned speed-control operating device 9 is an operating unit 18 of an actuator 17.
It is composed of The actuator 1
The position of the operating portion 18 is not changed by the pulling force of the governor spring 7. Further, a manual operation panel 3 is provided so that the position of the operation section 18 of the actuator 17 can be freely changed by an operation of the operator.
1 is provided. During the operation of the manual operation panel 31, the control operation by the limit switch 20 is released, and when the operation of the manual operation panel 31 is stopped, that is, after the predetermined high-speed position is set by the manual operation panel 31, , The control operation by turning on and off the limit switch 20 is started.

In the configuration of the second embodiment, the same operation as that of the first embodiment can be performed. In the second embodiment, the manual operation panel 31 controls the actuator 17.
It is necessary to be able to operate, but as compared with the configuration of the first embodiment, the speed adjusting lever 8, the low-speed rotation setting limit bolt 13, the high-speed rotation setting limit bolt 12, the tension spring 15, and the like are not required. There is an advantage that the speed control mechanism becomes compact. On the other hand, according to the configuration of the first embodiment, an engine having a general specification having the governing lever 8 can be used for a generator, and there is an advantage that manufacturing cost can be reduced.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the present invention. Hereinafter, such an embodiment will be described. (1) Needless to say, the configuration and the position of the limit switch 20 can be appropriately set according to the specifications of the engine. Further, the configuration of the position determining means 19 is not limited to the configuration of the switch. (2) In the first embodiment, the speed control lever 8 has been described as an example of the speed control device 9, but various speed control devices 9 employed in various engines are interlocked and connected to the governor spring 7. If it is, the same can be applied. However, when the speed adjusting operation tool 9 has a special configuration, it is necessary to consider the configuration of the actuator 17 to be driven.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram for explaining a centrifugal governor device for a diesel engine according to the present invention.

FIGS. 2A and 2B are diagrams illustrating the operation of a centrifugal governor device.

FIG. 3 is a schematic configuration diagram for explaining a second embodiment of the present invention.

FIG. 4 is a diagram for explaining a governor difference of a conventional centrifugal governor device.

[Explanation of symbols]

2 ... governor lever, 4 ... fuel injection pump, 5 ... control rack, 6 ... governor spring, 7 ... governor spring, 8 ... governor lever, 9 ... governor, 14 ... urging means, 16 ... drive means, 19 ... Position discriminating means, 33 ... Fuel metering tool.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 41/40 F02D 41/40 G

Claims (2)

[Claims] A governor lever (2) is interlockedly connected to a control rack (5) of a fuel injection pump (4), and a control rack (5) is connected to a governor spring via the governor lever (2).
(7), the governor force (6) urges the fuel to the fuel decreasing side (L), and the governor force (6) urges the fuel to the decreasing fuel side (L), and the governing lever (8) connected to the governor spring (7). ) Can be operated to adjust the tension of the governor spring (7). Further, an urging means (14) for urging the speed control lever (8) to a predetermined high-speed position, and a speed control lever (8) ) To the low-speed rotation side, and position determining means for determining whether or not the control rack (5) is at or below a predetermined low load position.
(19) is provided, and the control rack (5) is moved to a predetermined low position by the position discriminating means (19) during operation of the engine in which the governing lever (8) is previously set to the predetermined high-speed position by the urging means (14). In response to the determination that the load position is greater than the load position, the biasing means (14) is configured to maintain the governing lever (8) at the predetermined high-speed position, and the position determining means (19) In response to determining that the control rack (5) is at a position lower than the predetermined low load position, the speed control lever (8) is moved to the predetermined position by the driving means (16) against the urging force of the urging means (14). A centrifugal governor device for a diesel engine, wherein the centrifugal governor is configured to operate at a low speed position and maintain the predetermined low speed position. 2. A fuel metering device (33) for a fuel injection pump (4).
Is biased toward the fuel increasing side (R) by the governor spring (7) via the governor lever (2), while the governor force is
In (6), it is urged to the fuel reduction side (L), and the governor spring (7)
The speed of the governor spring (7) can be adjusted by moving the position of the speed control device (9) connected to the control device (9), and whether or not the fuel control device (33) is at a position lower than a predetermined low load position is determined. Position determining means (19) for determining whether the fuel metering tool (33) is in a predetermined position by the position determining means (19) during operation of the engine in which the speed adjusting operation tool (9) is set to a predetermined high-speed position in advance. The speed control device (9) is configured to maintain a predetermined high-speed position in response to the determination that the load position is larger than the low-load position, and the position determination means (19)
In response to the determination that the fuel metering device (33) is at a position lower than the predetermined low load position, the speed adjusting operation device (9) is operated to the predetermined low speed position and maintains the predetermined low speed position. A centrifugal governor device for a diesel engine, wherein the governor device is configured.