JP2864471B2 - Distributed fuel injection pump with boost compensator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distribution type fuel injection pump in which the amount of fuel injection is increased by a boost compensator.

[0002]

2. Description of the Related Art Generally, in a distribution type fuel injection pump for supplying fuel to a diesel engine, the fuel injection amount at the time of maximum load changes as shown in abcdcef of FIG. Is configured. That is, the fuel injection amount will become Q ₂ is at the start of the rotational speed of the engine to N ₁ (section a-b), during operation speed is N ₁ or more conventional Q ₁
become. By the way, recently, a diesel engine with a supercharger has been used, and a fuel injection pump for supplying fuel to this type of engine is often referred to as a boost compensator (hereinafter sometimes abbreviated as boucon). ) Is installed to increase the fuel injection amount in response to the increase in the intake air amount by the supercharger when the engine is rotating at high speed (see Japanese Utility Model Laid-Open No. 1-139038). For example, when the rotation speed of the engine exceeds a N ₂ the interval d-
Instead of the fuel injection quantity Q ₁ in e, the section d-d'-
The amount increases like e'-e.

[0003]

However, in the conventional distribution type fuel injection pump with a boucon, if an attempt is made to increase the fuel injection amount during high-speed rotation as in the section d-d'-e'-e, When the fuel injection amount at the time of startup is
-B 'fuel injection amount in Q ₃ (section d'-e' equal to the fuel injection amount.) Or more (the interval a "
−b ″, the fuel injection amount Q ₄ ), and there is a problem that the proper fuel injection amount Q ₂ at the start is greatly exceeded. Conversely, the fuel injection amount at the start is set at the appropriate amount Q ₂ . In this case, the fuel injection amount at the time of high-speed rotation can be increased only up to the fuel injection amount at the time of starting.
-D "-e" -e can only increase the amount,
There is a problem that the fuel injection amount cannot be sufficiently increased. The reason for this problem will be described later.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and has a boost compensator capable of sufficiently increasing the fuel injection amount during high-speed rotation while appropriately maintaining the fuel injection amount at the time of starting. It is an object to provide a distribution type fuel injection pump.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a booster having a boocon lever which rotates toward a fuel increasing side in response to an increase in boost pressure when the boost pressure exceeds a predetermined pressure. A compensator, a tension lever whose rotation toward the fuel increasing side is restricted by abutting on the boocon lever, and a rotation with the tension lever in contact with the tension lever during operation of the engine to start the engine sometimes the boost compensator with distributor type fuel injection pump having a governor lever assembly having a start lever to increase when starting the fuel injection quantity by turning away from the tension lever to the fuel increase side, the boost compensator, the When the engine is started, the fuel injection amount at start
Than the maximum fuel injection amount regulated by the
Turn the start lever toward the fuel increase side to reduce
Momentum, and the boost pressure is lower than the predetermined pressure.
When it is above, from the start lever to the fuel increase side
As the distance increases, the fuel increases according to the increase in the boost pressure.
A sub boucon lever is provided which can be turned to the side . In this case, the auxiliary boucon lever may be formed integrally with the boucon lever, or may be formed separately.

[0006]

[Function] When starting the engine, increase the fuel on the start lever.
Is restricted by the auxiliary boucon lever . It
The fuel injection amount at startup is controlled by the tension lever.
Is smaller than the maximum fuel injection amount that is regulated. When the boost compensator is activated, the auxiliary boucon lever rotates to the fuel increasing side, so the start lever and tension
The rotation of the lever toward the fuel increase side is controlled by the auxiliary boucon lever.
Are not regulated. Therefore, tension lever
The maximum fuel injection amount regulated by
More than quantity.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the distribution type fuel injection pump of this embodiment has the same configuration as the conventional one except for a part of the boocon lever 38. Therefore,
First, components similar to those of the related art will be briefly described.

In FIG. 1, reference numeral 1 denotes a pump chamber 2 inside.
Are formed in the pump housing. A barrel 4 is attached to the pump housing 1 via a block 3. A plunger 5 is slidably provided in the barrel 4. The plunger 5 is configured to reciprocate integrally with a cam disk 6 driven to rotate by a drive shaft (not shown).

In the above configuration, when the plunger 5 moves forward (moves leftward in FIG. 1), the fuel in the fuel pressurizing chamber 7 is pressurized. The pressurized fuel is pressure-fed to a fuel injection nozzle (not shown) via a delivery valve 8,
From there, it is injected into the combustion chamber (not shown) of the engine. When the cutoff port 5a is exposed from the control sleeve 9 to the pump chamber 2 during the forward movement of the plunger 5, the fuel in the fuel pressurizing chamber 7 flows out to the pump chamber 2 through the cutoff port 5a. This allows plunger 5
, The actual fuel pressurization ends, and the fuel injection ends. Therefore, when the control sleeve 9 is displaced in the forward movement direction of the plunger 5 (the direction of arrow A in FIG. 2), the fuel injection amount increases, and when the control sleeve 9 is moved in the opposite direction, the fuel injection amount decreases. When the plunger 5 returns, the pump chamber 2
The fuel inside is sucked and introduced into the fuel pressurizing chamber 7 through the passage 3a.

In this distribution type fuel injection pump, a governor mechanism 10 is provided to adjust the fuel injection amount by displacing the control sleeve 9, and the fuel injection amount at the maximum load is adjusted according to the boost pressure. A boost compensator 30 for adjusting the pressure is provided.

First, the boost compensator 30 will be described. A casing 31 is mounted on the upper part of the pump housing 1. The inside of the casing 31 is partitioned by a diaphragm 32 into a boost pressure chamber 33 and an atmospheric pressure chamber 34. A boost pressure of intake air supplied to the engine from a supercharger (not shown) is introduced into the boost pressure chamber 33. On the other hand, the atmospheric pressure chamber 34 is opened to the outside, and the atmosphere is introduced. A spring 35 is disposed in the atmospheric pressure chamber 34, and the diaphragm 35 urges the diaphragm 32 from the atmospheric pressure chamber 34 toward the boost pressure chamber 33.

An upper end of an adjusting pin 36 is fixed to the center of the diaphragm 32. As shown in FIG. 4, the adjusting pin 36 increases the boost pressure introduced into the boost pressure chamber 33 to a predetermined pressure P ₁ (the boost pressure becomes P ₁ when the engine speed reaches N ₂ ). When it exceeds, the diaphragm 32 moves in the direction of arrow C in FIG. 2 as the diaphragm 32 moves toward the atmospheric pressure chamber 34. However, when the boost pressure reaches a pressure P ₂ (the rotational speed of the engine becomes N ₃ boost pressure is P _2.), Since the adjusting pin 36 reaches the movement limit position, the boost pressure P ₂
Does not move in the direction of arrow C.

The adjusting pin 36 has a tapered portion 36a having a diameter gradually decreasing from the lower end toward the upper end. One end of a pin 37 is in contact with the tapered portion 36a , and the other end of the pin 37 is in contact with the upper end of a boucon lever 38.
The boocon lever 38 has an intermediate portion rotatably provided on the pump housing 1 via a shaft 39, and a first stopper portion with which a tension lever 13 described below abuts on a left portion below the shaft 39. 38a are formed.

Next, the governor mechanism 10 will be described. The governor mechanism 10 includes a governor lever assembly 11 for directly displacing the control sleeve 9. The governor lever assembly 11 includes a collector lever 12, a tension lever 13, and a start lever 1.
4 is a main component, and the collector lever 1
2 is rotatably provided on the pump housing 1 via a shaft 15 (see FIG. 2). However, one end of the collector lever 12 is biased by a strong spring 16,
The other end abuts the adjusting bolt 17 by the urging force. Therefore, unless the adjustment bolt 17 is adjusted forward and backward, the collector lever 12 does not rotate.

The tension lever 13 is rotatably supported by the collector lever 12 via a shaft 18. A governor spring 20 is provided between the tension lever 13 and a control lever 19 provided on the pump housing 1. When the control lever 19 is turned to the fuel increasing side, the tension lever 13 is moved to the governor spring 20. The first stopper portion 38a of the boucon lever 38 is rotated in the direction of arrow F in FIG.
It comes to hit. When the tension lever 13 abuts against the first stopper portion 38a, the boucon lever 38 is pressed into contact with the pin 37, and the pin 3
7 comes into pressure contact with the tapered portion 36a of the adjusting pin 36.

The start lever 14 is rotatably supported on a shaft 18. The lower end of the start lever 14 is engaged with the control sleeve 9. When the start lever 14 rotates in the direction of arrow F, the control sleeve 9 moves toward the fuel increasing side (in the direction of arrow A). When the lever 14 rotates in the direction of arrow G, the control sleeve 9 moves toward the fuel decreasing side (direction of arrow B).

Further, one end of a start spring 14a is fixed to the start lever 14. The other end of the start spring 14a abuts against the tension lever 13, and urges the start lever 14 to rotate in the direction of arrow F with respect to the tension lever 13. Therefore, the start lever 14
When the engine is started, it is rotated in the direction of arrow F by the urging force of the start spring 14a, and is separated from the tension lever 13. However, as will be described later, during normal rotation of the engine, the engine comes into contact with the projection 13a of the tension lever 13 and rotates integrally with the tension lever 13.

A governor shaft 2 having an axis crossing the start lever 14 is provided on a wall of the pump housing 1.
1 is fixed. The governor shaft 21 is rotatably provided with a fly weight holder 23 which is rotated via the gear 22 by the drive shaft. The fly weight holder 23 has a fly weight 24
Is installed. When the rotation speed of the flyweight holder 23 increases, the flyweight 24 rotates in the direction of the arrow in FIG. 1 (hereinafter, rotation in the direction of the arrow is called open rotation, and rotation in the opposite direction is called close rotation). )).

A governor sleeve 25 is slidably provided on the governor shaft 21. The governor sleeve 25 is pressed toward the distal end when the fly weight 24 is opened and rotated.
The tip of 5 is in contact with the start lever 14.
Thus, the governor sleeve 25, during normal operation other than the start of the engine moves toward the distal end side by the pressing force of the flyweight 24 (the rotational speed is N ₁ or more during operation in FIG. 3) (hereinafter, referred to as forward )) And start lever 1
4 is rotated in the direction of arrow G to abut on the protrusion 13 a of the tension lever 13. Then, while maintaining this state, the start lever 14 and the tension lever 13 are pressed to rotate in the direction of arrow G against the urging force of the governor spring 20. Therefore, the tension lever 13 and the start lever 14 rotate so that the pressing force of the governor sleeve 25 and the biasing force of the governor spring 20 are balanced, and stop at a position where the two forces are balanced.

Next, the features of the present invention will be described.
In order to clarify the contents of the present invention, the operation of the distribution type fuel injection pump with boucon (having the same configuration as the conventional one) with the above configuration will be described first with reference to FIG.

Now, it is assumed that the engine is rotating in the range of the number of revolutions N _{1 to} N ₂ . At this time, the start lever 14 comes into contact with the protrusion 13 a of the tension lever 13, and rotates together with the tension lever 13. In this state, when the control lever 19 is turned to the maximum load state, the tension lever 13 and the start lever 14 are turned in the direction of arrow F by the urging force of the governor spring 20. When the tension lever 13 comes into contact with the first stopper portion 38a of the boocon lever 38, both levers 13 and 14 stop. By turning the start lever 14 in the direction of arrow F,
The control sleeve 9 is moved in the direction of arrow A. Fuel injection amount at this time is a fuel injection amount Q ₁ defined by the section c-d of FIG.

[0022] In the above state, increases the rotational speed of the engine reaches the pressure P ₁ boost pressure rises with it, boost compensator 30 begins to operate, the adjusting pin 36 in response to the boost pressure 2 In the direction of arrow C. When the adjusting pin 36 moves in the direction of arrow C, the pin 37 can move in the direction of arrow D, and the boocon lever 38 can rotate in the direction of arrow E. Therefore, the tension lever 13 and the start lever 14
Is rotated in the direction of arrow F with the movement of the adjusting pin 36 by the urging force of the governor spring 20. As the levers 13 and 14 rotate, the governor sleeve 25 is retracted, and the control sleeve 9 is moved in the direction of arrow A, thereby increasing the fuel injection amount. Fuel injection amount, revolution speed of the engine reaches N _3,
Boost pressure is increased until it reaches the P ₂ (section Figure 3 d
-D "-d ').

If the adjusting pin 36 reaches the movement limit position in the direction of arrow C and cannot move any further, the boucon lever 38 cannot rotate in the direction of arrow E, so that the engine speed increases. As a result, the boost pressure becomes P ₂
Even after the above, the fuel injection amount becomes the maximum fuel injection amount and becomes constant (section d'-e ').

Here, even if the fuel injection amount is maximized, the governor sleeve 25 can be further retracted, and the control sleeve 9 moves further toward the fuel increasing side, that is, the arrow A
It can move in any direction. In this embodiment, the governor sleeve 25 and control sleeve 9, the amount of fuel injection is movable until Q _4. This is because when the fuel injection amount reaches the maximum fuel injection amount, if at least one of the governor sleeve 25 and the control sleeve 9 cannot be moved further to the fuel increasing side, the sleeve 9, This is because there is a possibility that a desired maximum fuel injection amount may not be obtained due to a dimensional error or an assembly error of 25 or the like, and such an inconvenience is prevented by providing a certain margin.

When the rotation speed of the engine exceeds N ₄ , the levers 13 and 14 are pushed by the governor sleeve 25 due to the pressing force of the governor sleeve 25 accompanying the opening rotation of the fly weight 24.
It is turned in the direction of arrow G against the urging force of 0, and the fuel injection amount gradually decreases (section e′-e ″ -ef).

As described above, the control sleeve 9 and the governor sleeve 25 have the fuel injection amount in the section d'-
Until the fuel injection amount of e '(equal to the fuel injection amount in the section a "-b"), the fuel can be moved to the fuel increasing side. Under such a configuration, when the engine is started, in order to increase the fuel injection amount at the time of starting, the control lever 19 is rotated to the fuel increasing side, and the tension lever 13 is moved to the boocon lever 38.
The start lever 14 is rotated in the direction of arrow F by the start spring 14a. Accordingly, the control sleeve 9 and the governor sleeve 25 are moved toward the fuel increasing side. In this case, the control sleeve 9
And the governor sleeve 25 is moved to any of the movement limit positions to the fuel increase side. Therefore, the starting time fuel injection quantity becomes the fuel injection quantity Q ₄ of the section a "-b". The fuel injection amount Q ₄ are, those exceeding the fuel injection amount Q ₂ of the section a-b is a proper start timing fuel injection amount significantly.

In order to prevent such inconvenience, that is, to make the fuel injection amount at the time of starting appropriate, in the fuel injection pump of the present invention, the boocon lever 38 is provided with the second stopper portion 38b. .

That is, the lower end of the boocon lever 38 has a second position at a position facing the upper end of the start lever 14.
A stopper 38b is formed. When the start lever 14 abuts against the second stopper portion 38b, the start lever 14 at the time of starting the engine is moved.
Of is intended for restricting the rotation amount, so that the fuel injection amount in a state in which the start lever 14 hits the second stopper portion 38b is a fuel injection quantity Q ₂ in the section a-b in FIG. 3, arranged Is formed.

However, during normal operation of the engine, the start lever 14 does not hit the second stopper portion 38b. The load on the engine is the maximum load, and the engine speed is N
₁ to N ₂ in a range in the (boost compensator 30 is a range in inactive state), the tension lever 13 is abutting against the first stopper portion 38a in the same manner as in the start-up. On the other hand, the start lever 14 is rotated in the direction of arrow G by the governor sleeve 25, and the tension lever 14
Is in contact with Therefore, the second stopper 38b and the start lever 14 are separated by an amount corresponding to the rotation of the start lever 14 in the direction of the arrow G after leaving the second stopper 38b. The distance between the start lever 14 and the second stopper 38b in this state is hereinafter referred to as a start stroke.

When the engine speed exceeds N ₂ , the boocon 30 operates and the boocon lever 38 rotates in the direction of arrow E. Then, the tension lever 13 rotates in the direction of the arrow F, and the start lever 14 rotates integrally therewith. However, at this time, the second stopper portion 38b
Is rotated by the boucon lever 38 in the direction of arrow E,
It moves in a direction away from the start lever 14. The total distance of this movement distance and the above-mentioned start stroke is set to be always larger than the distance approaching the second stopper portion 38b by the rotation of the start lever 14. Therefore, even if the boucon 30 operates,
The start lever 14 does not hit the second stopper portion 38b.

In particular, in this embodiment, since the second stopper portion 38b is formed at a position farther from the shaft 39 than the first stopper portion 38a, the second stopper portion 38b associated with the rotation of the boocon lever 38 is formed. The moving distance is larger than the moving distance of the first stopper 38a. Therefore, it is possible to reliably prevent the start lever 14 from hitting the second stopper portion 38b during the operation of the boocon 30. In addition, as long as the moving distance between the start stroke and the second stopper portion 38b due to the rotation of the boocon lever 38 is always longer than the moving distance to the second stopper portion 38b due to the rotation of the start lever 14, The location where the two stoppers 38b are formed is arbitrary.

In the distribution type fuel injection pump provided with the second stopper portion 38b, when the start lever 14 is turned to the fuel increasing side at the time of starting, the amount of the rotation is the second amount.
It is regulated by the stopper 38b. Therefore, when appropriate start-up fuel injection amount Q ₂ is obtained.

Here, if the fuel injection amount at the time of starting is simply adjusted to an appropriate value, for example, a pin or the like is fixed to the pump housing 1 or the casing 31 and the start lever 14 abuts on the pin. The starting fuel injection amount can be made appropriate.

However, if an appropriate starting fuel injection amount is obtained by using such pins, a desired maximum fuel injection amount cannot be obtained. That is, when the pin is fixed, the range in which the start lever 14 can be turned to the fuel increasing side is restricted by the pin regardless of whether it is during start-up or during normal operation. Therefore, the start timing fuel injection amount when that has been set to Q _2, initially the operation of the boost compensator 30, boost compensator lever 38 with the rotation in the arrow E direction to the tension lever 13 and start lever 14 is a fuel increase side Then, the fuel injection amount increases (section d-d ″ in FIG. 3). However, when the fuel injection amount reaches Q ₂ , the start lever 14 hits the pin, so that the boocon 30 increases the fuel. Start lever 1
4 and the tension lever 13 cannot rotate to the fuel increasing side. Therefore, the maximum fuel injection amount obtained becomes Q ₂ (section d "-e").

In this regard, in this distribution type fuel injection pump, the second type for restricting the rotation of the start lever 14 is described.
The stopper portion 38b is formed on the boocon lever 38, and when the start lever 14 rotates to the fuel increasing side, the second stopper portion 38b moves so as to be separated from the start lever 14. Therefore, the second stopper portion 38b
Does not hit the start lever 14. Therefore, it is possible to increase the maximum fuel injection amount until the desired fuel injection quantity Q _3.

The present invention is not limited to the above-described embodiment, and can be appropriately modified without departing from the gist thereof. For example, in the above-described embodiment, the second stopper portion 38b is formed on the boucon lever 38, but another boucon lever (sub boucon lever) that rotates following the pin 37 can be freely rotated on the casing 31. And a second stopper portion with which the start lever 14 abuts on the auxiliary boucon lever may be formed. As is apparent from this point, it can be said that the above-described embodiment has the auxiliary boucon lever formed integrally with the boucon lever 38. In addition to the pin 37, the adjusting pin 3
Another pin that moves following the movement of 6 may be provided, and the auxiliary boucon lever may be rotated by this pin.

[0037]

As described above, according to the distribution type fuel injection pump with the boost compensator of the present invention,
The boost compensator is provided with a sub-boocon lever that rotates to increase the fuel as the boost pressure increases, and the sub-boocon lever restricts the rotation of the start lever when the engine is started. In this case, it is possible to obtain an effect that the fuel injection amount can be made appropriate and the maximum fuel injection amount can be increased to a desired amount.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a main part of one embodiment of the present invention.

FIG. 3 is a diagram showing a fuel injection amount characteristic under a maximum load in one embodiment of the present invention.

FIG. 4 is a diagram illustrating a relationship between a boost pressure and a moving distance of an adjusting pin in a boost compensator.

[Explanation of symbols]

 Reference Signs List 11 governor lever assembly 13 tension lever 14 start lever 30 boost compensator 38 boocon lever 38a first stopper portion 38b second stopper portion

Claims (2)

(57) [Claims] 1. A boost compensator having a boocon lever which rotates to the fuel increasing side in response to an increase in the boost pressure when the boost pressure becomes equal to or higher than a predetermined pressure; Is controlled by the tension lever, and rotates together with the tension lever in contact with the tension lever during operation of the engine. A governor lever assembly having a start lever for increasing the amount at start-up, wherein the boost compensator includes:
When the engine is started, the fuel injection amount at the time of starting
Less than the maximum fuel injection amount regulated by the
The amount of rotation of the start lever to increase the fuel
And the boost pressure is equal to or higher than the predetermined pressure.
Sometimes, move away from the start lever to increase fuel
As the boost pressure increases, the fuel increases.
A distribution type fuel injection pump with a boost compensator, comprising a sub boucon lever that can be rotated . 2. The distribution type fuel injection pump with a boost compensator according to claim 1, wherein the auxiliary boucon lever is provided integrally with the boucon lever.