JP2939599B2 - Mechanical governor for diesel engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical governor for a diesel engine in which rotation speed fluctuations due to load fluctuations at low speed rotation are reduced.

<Prior Art> As is well known, an idle spring in a mechanical governor of this type is a weak spring having a considerably smaller spring constant than a governor spring. The idling rotation speed is maintained.

FIG. 5 illustrates the relationship between the maximum rack position with respect to the number of rotations and the number of rotations and the rack position in a low load state (hereinafter referred to as NR characteristics). If the spring force of the idle spring is high, the slope of the NR characteristic becomes gentle like A or A ', and the governor action becomes pure, and the rotation speed fluctuation accompanying the load fluctuation increases, but the spring force is weak. And B or B ', the inclination becomes steep, the governor becomes sensitive, and the rotation speed fluctuation accompanying the load fluctuation becomes small.

However, in order to stabilize the number of revolutions at the time of idling, it is preferable that the slope of the NR characteristic is gentle like A, and B
If the inclination is steep, the rack position will fluctuate greatly even with a slight change in the number of revolutions, and idle hunting will easily occur, and a good settling state cannot be obtained. Therefore, in a general governor, the spring constant of the idle spring is selected so that NR characteristics such as A can be obtained.

<Problem to be Solved by the Invention> When the slope of the NR characteristic is gentle as described above, the load increases when the idle spring is still effective, that is, when the engine is operating at a low speed relatively close to the idle speed. This results in a large decrease in the number of revolutions. For example, in a work boat, when operating the engine at a low speed NL close to the idle speed Nidl to secure a fixed position against the tide, and at the same time operating a compressor to send air to diving workers, When other equipment such as a side thruster or a hoist is operated, if the NR characteristic such as A 'is used, the engine speed is greatly reduced due to an increase in load, and the compressor cannot be operated sufficiently. It is very dangerous. In order to avoid this, at idle speeds other than the idling range, the spring force of the idle spring may be weakened and the slope of the NR characteristic may be steeper as in B '. The spring force cannot be adjusted during the operation of.

When the spring force of the idle spring is adjusted so as to be optimal for idling, the same effect as when the spring force of the entire governor spring is increased is produced. For this reason,
As shown in C, the settling state near the no-load maximum rotation speed deteriorates, and the maximum rotation speed Nmax increases, causing a problem such as abrasion of the drive system and jumping.

Conventionally, adjustments have been made while appropriately balancing these problems.

The present invention pays attention to such a problem, and can select the spring force of the idle spring so as to be optimal for idling, and furthermore, suppresses fluctuations in the number of rotations in a low rotation speed region under a load state, and does not deteriorate the settling at the highest rotation speed. It was made for the purpose of.

<Means for Solving the Problems> In order to achieve the above object, according to the present invention, an auxiliary idle spring that generates a spring force in the same direction as an idle spring, and the auxiliary idle spring only in an idling rotation range And a control means for cooperating with each other. The spring force of each spring is selected so that a predetermined spring constant suitable for idling can be obtained in a state where both springs cooperate.

<Operation> When the auxiliary idle spring cooperates with the idle spring, the spring force of the auxiliary idle spring is applied to the idle spring, whereby the spring force is strengthened, and a relatively gentle NR characteristic suitable for idling can be obtained. . Further, the spring force of the auxiliary idle spring does not act outside of the idling rotation range, the NR characteristic becomes relatively steep, the rotation speed fluctuation in the low rotation range under load is reduced, and the setting state at the maximum rotation is set. Does not get worse.

<Example> Next, an example of the present invention will be described. FIG. 1 is a partially cut-away schematic side view showing a configuration of a main part, FIG. 2 is a schematic side view,
FIG. 3 is a sectional view of the auxiliary idle spring unit, and FIG. 4 is a connection diagram.

In the figure, 1 is a mechanical governor, 2 is a flyweight, 3 is a weight sleeve, 4 is a governor lever, 5
Is a tension lever, 6 is a regenerator lever, 7 is a governor spring, 8 is a link, 9 is a control rack, and 10 is an idle spring. Fly weight 2
Is rotated and spreads, the weight sleeve 3 moves accordingly, the governor lever 4 rotates, and the control rack 9 moves in the depressing direction via the link 8. Further, in response to the operation of an accelerator (not shown), the regulator lever 6 rotates counterclockwise, the tension lever 5 rotates via the governor spring 7, and the movement is transmitted to the governor lever 4 via the idle spring 10. For this reason, the control rack 9 moves in the increasing direction, the fuel corresponding to the operation amount and the load of the accelerator is supplied, and the operation is interrupted at the rotation speed at which the centrifugal force of the flyweight 2 and the spring force of the governor spring 7 are balanced. . When the load exceeds a certain value, the idle spring 10 is completely compressed.

6a is an external lever portion of the regulator lever 6 connected to the accelerator, 6b is a regulator lever shaft, 11 is an idle speed set bolt, and 12 is a combustion limiting bolt.

The above operation, the structure of each member, and the like are basically the same as the well-known ones, and thus detailed description is omitted.

Next, a part related to the present invention will be described. Reference numeral 15 denotes an auxiliary idle spring unit which is screwed to the governor housing 1a and fixed by a lock nut 15a, and 16 is an auxiliary idle spring. The auxiliary idle spring 16 is provided inside a slide body 17 housed in a case 15b of the unit 15, and presses an operation rod 18 protruding from the slide body 17. Unit 15 is an electromagnetic magnet type, 19 is an exciting coil, 20 is its plunger,
When the exciting coil 19 is excited, the plunger 20 is attracted to be in a solid line state, and the operating rod 18 is pushed out by pressing the slide body 17 with the tip 20a, and the tip of the governor lever 4 is pushed.
Abuts on the contact surface 4a at the end of the contact. Therefore,
When idling is performed in this state, the governor lever 4 is supported by the spring force of the auxiliary idle spring 16, and the tension lever 5 is in a state in which the spring force of the idle spring 10 is applied to the spring force of the idle spring 10. As a result, the idle spring 10 is reinforced by the auxiliary idle spring 16. 21 is the operation stick 18
And a return spring for returning the slide body 17 and the like to the position indicated by the chain line.

Here, a constant is selected for the idle spring 10 and the auxiliary idle spring 16 so that a predetermined spring force suitable for idling can be obtained when the spring force of both springs is applied. The spring is weaker than the governor.

25 is screwed into the governor housing 1a and lock nut 25a
The idling position detection switch is fixed by an external lever portion of the regulator lever 6 in the same manner as the idle speed set bolt 11, for example.
When the regulator lever 6 is in the idling position, it is turned on when it comes into contact with the ridge 6c of 6a.
The switch 25 can be attached to a position other than the position shown in the figure.

In FIG. 4, reference numeral 26 denotes a fuel injection pump in which the mechanical governor 1 is assembled, 27 denotes a battery, and 28 denotes a selection switch that is turned on when the auxiliary idle spring 16 is operated. A series circuit of the detection switch 25 and the selection switch is connected to the battery 27.

This embodiment is configured as described above, and includes a selection switch.
When 28 is on, the detection switch 25 is turned on during idling, and the auxiliary idle spring unit
The 15 excitation coils 19 are excited. For this reason, the operating rod 18 projects and its tip hits the contact surface 4a of the governor lever 4, and the spring force of the idle spring 10
As shown in FIG. 5, at the idle speed Nidl, the slope of the NR characteristic becomes gentle as shown at A, and a stable governor action is exhibited. The idling speed is usually 400 to 450 rpm, but the range varies depending on the type and size of the engine, so the range for operating the auxiliary idle spring 16 adjusts the mounting position of the idling position detection switch 25. It is selected as appropriate.

Further, in a state where the engine is operated at a rotation speed NL slightly higher than the idling rotation speed with a certain load applied, for example, about 500 to 700 rpm, the detection switch 25 is turned off since the regulator lever 6 is rotated according to the load. Becomes As a result, the exciting coil 19 is de-energized, the operating rod 18 is retracted by the return spring 21, and the auxiliary idle spring 16
The effect of reinforcing the spring force is eliminated. Therefore, the NR characteristic has a steep slope like B ', and the rack position greatly fluctuates even with a small change in the rotation speed, thereby suppressing the change in the rotation speed. Therefore, even if the load increases, the rotation speed is increased. It does not decline.

In addition, the detection switch 25 is off because the regulator lever 6 has rotated to some extent near the no-load maximum rotation speed, and the no-load maximum rotation speed Nmax does not increase as in C.

Even if the spring force of the idle spring 10 itself is small, the spring force required for idling can be obtained by reinforcement with the auxiliary idle spring 16, so that the idle spring 10 By setting the spring force of the idle spring 10 small, the idle spring 10 can also serve as the increasing spring at the start.

<Effects of the Invention> As is apparent from the above description, the present invention provides an auxiliary idle spring to cooperate with the idle spring only in the idling rotation range so as to reinforce the spring force of the idle spring. In other cases, the spring force of the auxiliary idle spring is not applied.

Therefore, N- with a relatively gentle slope suitable for idling
The mechanical governor can realize both the R characteristic and the NR characteristic having a relatively steep slope other than the idling rotation region, and the rotation speed fluctuation in the rotation region where the load condition is reduced is reduced, and The setting state in rotation does not deteriorate.

For this reason, even when the load fluctuates when the engine is operating at a low speed, the fluctuation in the engine speed is suppressed.For example, in a work boat, even if other equipment is operated while the air supply compressor is operating, the compressor may not operate. There is no reduction in the number of revolutions that would cause a malfunction, and a dangerous situation can be avoided.
In addition, since the setting at the maximum rotation is also maintained in a good state, it is possible to prevent the maximum rotation speed with no load from increasing and causing abrasion of the drive system and jumping.

[Brief description of the drawings]

FIG. 1 is a partially cut-away schematic side view showing the configuration of a main part of one embodiment of the present invention, FIG. 2 is a schematic side view, FIG. 3 is a sectional view of an auxiliary idle spring unit, and FIG. FIG. 5 is a diagram showing an example of the NR characteristics. 1 ... mechanical governor, 4 ... governor lever, 4a ... contact surface, 5 ... tension lever, 6 ... regulator lever, 10 ... idle spring, 15 ... auxiliary idle spring unit, 16 ... auxiliary idle Spring, 17
... Slide body, 18 ... Operation rod, 19 ... Exciting coil, 20 ... Plunger, 25 ... Idling position detection switch, 28 ... Selection switch.

Claims (1)

(57) [Claims] An auxiliary idle spring for generating a spring force in the same direction as the idle spring; and control means for causing the auxiliary idle spring to cooperate with the idle spring only in an idling rotation range. A mechanical governor for a diesel engine, wherein spring constants of both springs are selected so that a predetermined spring force suitable for idling is obtained when spring forces of an idle spring and an auxiliary idle spring are applied.