JPH02199232A - Timing control for fuel injection for internal combustion engine - Google Patents

Abstract

PURPOSE:To facilitate engine starting by applying particular actuating force to a link mechanism by means of an actuating mechanism interlocked with a starter at the time of engine starting so as to be advanced, and thereby preventing said particular actuating force from being transmitted to an external control means by means of a lost motion mechanism. CONSTITUTION:A solenoid 30 is energized with a starter switch turned on so that a projection 30' is projected out, an injection timing regulating shaft 19 of a fuel injection valve 1 being moved via a rotating shaft 23 with a lever 26 rotated by specified turns, a control sleeve 12 coupled in a plunger 5 being moved, the fuel injection timing being thereby advanced. In this case, the movement of the lever 26 is absorbed by a lost motion mechanism interposed within a link 28, but is not transmitted to an accelerator lever 27 acting as an external control means. By this constitution, the injection timing is exceptionally advanced to facilitate engine starting without affecting the set valve of the external control means, it is thereby possible in an intended engine to contrive to let high performance at the time of normal operations be compatible with easiness in starting when the engine is started.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for fuel injection timing in a fuel injection pump for an internal combustion engine.

[Conventional technology]

In fuel injection pumps for diesel engines, in order to adjust the fuel injection timing, a control sleeve is provided that is inserted into the plunger that pressurizes the fuel, and this is moved in the axial direction of the plunger by the injection timing adjustment shaft (control Rondo). It is known that the timing of the start of fuel injection is changed by
In the device described in Japanese Patent No. 18936, a computer-controlled rotary solenoid rotates an injection timing adjustment shaft.

[Problem to be solved by the invention]

In the example of the conventional technology mentioned above, the fuel injection timing can be adjusted to the optimal state according to the operating state of the engine, but the structure of the control system becomes extremely complicated, resulting in a significant increase in cost. .

There is a general tendency that it is better to advance the fuel injection timing during steady engine operation when the engine speed is high, so if that is all you need, it is not necessary to use a computer-controlled rotary solenoid as in the example above. However, contrary to the above-mentioned tendency, the injection timing can be adjusted by moving the control sleeve by pure mechanical means, but this is different only at the time of starting, even though the rotational speed is at or near O. Due to the irregular property that starting is easier when the injection timing is advanced more than when idling, and because it is not known whether the accelerator lever is released at the time of starting, etc., the control means The configuration of the system has become increasingly complex, and this can be said to be one of the reasons for preventing the realization of control means with a simple configuration.

[Means to solve the problem]

A fuel injection timing control device for an internal combustion engine according to the present invention includes a control sleeve that is fitted into a plunger of a fuel injection pump and can be moved in the axial direction of the plunger in order to adjust the injection timing of fuel; a series of link mechanisms connecting them for adjusted movement by an external control means, an idle movement mechanism inserted into a part of the link mechanisms, and a side of the control sleeve viewed from the idle movement mechanism. The present invention is characterized by comprising an actuating device attached to a part of the link mechanism and advancing the fuel injection timing in conjunction with at least the starter.

[For production]

Since the present invention is configured as the above means, the operating force applied to the external control means, such as the accelerator lever of the engine, is transmitted to the fuel injection pump via the link mechanism, and the plunger is The fuel injection timing is adjusted by moving the control sleeve fitted into the cylinder. However, when the engine is started, an actuating device attached to the link mechanism and interlocked with the starter intervenes in the link mechanism and applies an operating force to advance the fuel injection timing independently of the external control means. It is supplied to the control sleeve of the fuel injection pump to advance it and facilitate starting. At this time, part of the special operating force for advancing the fuel injection timing that is supplied to the link mechanism in conjunction with the starter as described above is absorbed by the idle movement mechanism and is reversed to the external control means. Therefore, the advance angle value suitable for starting is transmitted only to the control sleeve of the fuel injection pump, and the advance angle value suitable for starting is transmitted to the fuel injection pump, regardless of the advance angle value instructed by the external control means. can give.

〔Example〕

1 to 6 showing one embodiment of the present invention, a fuel injection pump 1 of any type has three cylinders 3 fixed to a housing 2, and a plunger 5 driven by a cam 4 is connected to the cylinders 3. It is inserted therein and supported so as to be movable in the axial and rotational directions.

6 is a spring that pushes down the plunger 5 toward the cam 4; 7 is a fuel inlet; 8 is a horizontal common fuel storage chamber; 9 is a fuel pressurizing chamber; 10 is a high-pressure fuel delivery valve to each cylinder of the engine; No. 1 indicates the fuel outlet.

A control sleeve 12 is slidably inserted into each of the plungers 5 in the fuel reservoir chamber 8, and each control sleeve 12 itself is guided by a guide 13 on the inner wall surface of the fuel reservoir chamber 8, and the plunger Adjustment movement is possible only in the axial direction of 5. A lead hole 14 opens diagonally on the side surface of the control sleeve 12, and this and a lower edge 15 of the control sleeve 12 open on the side surface of the plunger 5 and communicate with the fuel pressurizing chamber 9 through a passage 16. hole 1
The operating state of the fuel injection pump 1 changes depending on the position it occupies relative to the fuel injection pump 7.

That is, as shown in FIG.
When the hole 17 is closed by the lower edge 15 of the control sleeve 12, pressurization of the fuel starts in the pressurizing chamber 9, and the pressurized fuel is transferred to the high-pressure fuel delivery valve 1.
Since the fuel is pushed open and sent to the corresponding cylinder, the fuel injection valve of that cylinder starts injecting fuel at the same time.

When the plunger 5 is further pushed up and reaches a position where the hole 17 communicates with the lead hole 14 as shown in FIG. ends at that point.

Although a detailed explanation will be omitted as it is not directly related to this invention, since the lead hole 14 is a long hole in an oblique direction, the injection The time from the beginning to the end, that is, the fuel injection amount changes.

As is clear from the explanation of FIG. 5, the timing at which fuel injection starts is determined by changing the axial position of the control sleeve 12-.
Adjustment can be made by determining the position of its lower edge 15. That is, if the cam lift from when the lift amount of the cam 4 is 0 to the start of fuel injection is called a prestroke, when the control sleeve 12 is moved downward, the prestroke becomes smaller and the fuel injection timing becomes earlier ( advance). Conversely, when the control sleeve 12 is moved upward, the prestroke becomes larger and the fuel injection timing is delayed (retarded). Therefore, in order to simultaneously move the control sleeves 12 fitted into each plunger 5 up and down, the grooves 18 provided in each sleeve 12 have a common injection timing adjustment shaft that passes through the housing 2 in the lateral direction. Three pins 20 installed in the control sleeve 19 are engaged with each other, and the height of the control sleeve 12 changes simultaneously depending on the angle at which the adjustment shaft 19 is rotated.

As shown in FIG. 3, a block 21 is fixed at the location where the injection timing adjustment shaft 19 protrudes from the housing 2, and a pin 22 is implanted on the upper surface of the block 21. A vertical rotation shaft 23 is supported on the housing 2, and a fork 24 is fixed to the lower end surface of the housing 2, and a pin 22 of the above-mentioned professional 7 is engaged in a long groove of the fork 24. Therefore, when the rotation shaft 23 is rotated within the angular range, the block 21 is tilted due to the engagement between the fork 24 and the pin 22, and the injection timing adjustment shaft 19 is rotated by an angle corresponding to the engagement of the fork 24 and the pin 22. is adjusted and moved up and down on the plunger 5.

A lever 26 is fixed to the upper end threaded portion 23' of the rotation shaft 23 by a nut 25 as shown in FIG.
Link 2 connecting the engine accelerator lever 27 and the engine accelerator lever 27
8 is constituted by two parts 28' and 28'' and a free movement mechanism 29 in the illustrated embodiment. Next to the lever 26, a protrusion 30' that can protrude to face the link 28 is provided. actuator, in this case solenoid 30
is supported by the housing 2 etc.,
When a starter switch (not shown) for starting the engine is turned on, the solenoid 30 projects to the right in FIG. 1 and pushes the lower end of the lever 26.
By rotating the rotation shaft 23 to the left, the control sleeve 12 is moved downward to advance the fuel injection timing.

The above-mentioned idle movement mechanism 29 is provided to prevent the accelerator lever 27 from moving under the influence of the protrusion 30' when the protrusion 30' is protruded by the actuating device (solenoid 30) actuated by the starter switch. In the embodiment of the lost motion mechanism shown in FIG. 4, portions 28' and 28'' of link 28
Flanges 31 and 32 formed at the ends of the cylinder 33 are inserted into the cylinder 33 so as to be movable in the axial direction, and both ends of the cylinder 33 are caulked inward to prevent the collars 31 and 32 from coming out, and to prevent the collars 31 and 32 from slipping out. is loaded with a compression spring 34, which urges the flanges 31 and 32 outward in opposite directions.

Therefore, the operating force from the accelerator lever 27 is applied to the lever 2.
6, the idle movement mechanism 29 moves as it is without being deformed, and no relative movement occurs between the parts 28' and 28'' of the link 28, but the starter switch causes the solenoid 3o to move. is activated, and when the protrusion 30' projects and presses the lower end of the lever 26 to the right, the spring 34 of the idle movement mechanism 29 is bent and the link part 28' is moved from the other part 2-8 which remains stationary. ” to absorb the displacement of the lever 26 and prevent the movement from being transmitted in the opposite direction towards the accelerator lever 27. In this way, in order for the idle movement mechanism 29 to transmit or not transmit the operating force depending on the direction of force transmission, it is necessary to move the lever 26 to the remote accelerator lever 27.
In practice, it is also necessary to increase the rotational resistance of.

In the embodiment illustrated in FIGS. 1 to 6, when the accelerator lever 27 is rotated, the plunger 5 of the fuel injection pump 1 is rotated by a mechanism whose explanation is omitted, and the plunger 5 of the fuel injection pump 1 is rotated to control the hole 17. The positional relationship between the sleeve 12 and the lead hole 14 changes, and the fuel injection amount force j in the engine cylinder changes, but at the same time, the accelerator lever 27 and the link 28
, lever 26, rotation shaft 23, fork 24, pin 22,
The injection timing adjustment shaft 19 is rotated by the interlocking action of the block 21, and the control sleeve 12 is connected to the plunger 5 via the pin 20.
Since it is moved in the axial direction at the top, the fuel injection amount,
Therefore, as the engine speed increases, the fuel injection timing is advanced as shown in FIG. 10, and the engine is operated with high efficiency.

However, when starting the engine, press the accelerator lever 2.
Regardless of the position of the lever 26, when the starter switch is turned on, the solenoid 30 is energized at the same time as the starter, and the protrusion 30' presses the lower end of the lever 26 to the right, causing the above-mentioned operation to occur. Similarly, the fuel injection timing is exceptionally advanced to facilitate starting. At this time, the operating force by the solenoid protrusion 30' is absorbed as a deflection of the spring 34 in the idle movement mechanism 29, and even if the accelerator lever 27 is in a low speed position such as idling, it is changed. Since the operating force in the opposite direction is not transmitted,
An advance of the fuel injection timing suitable for starting is achieved independently. When the engine starts and the power supply to the starter is stopped, the protrusion 30' also returns to the inside of the solenoid 30,
The injection timing is also determined depending only on the position of the accelerator lever 27.

Three other embodiments of the idle motion mechanism 29 are illustrated in FIGS. 7-9. Compared to the one shown in FIG. 4, the one shown in FIG.
They are substantially the same except that they are directly connected to the cylinder 33'.

The one shown in FIG. 8 is an example in which a tension spring is used instead of a compression spring, and a flange 35 is formed at the tip of a portion 28' of the link 28, and this is caulked to one end of a cylinder 36. A slider 38 is inserted into the internal space 37 of the cylinder 36, and the slider 38 has a slit 3 in the axial direction of the cylinder 36.
A pin 4o whose head extends outside through the hole 9 is implanted. A portion 28'' of the link whose tip is fixed to the slider 38 is loosely inserted into a hole in the cylinder 36.The cylinder 3
6 and the pin 40 of the slider 38
Since a tension spring 42 is placed between the slider 38 and the spring 42, the slider 38 is pressed against the right shoulder of the space 37 by the tension of the spring 42.

As can be easily understood from this structure, the idle motion in the example shown in FIG. 8 is caused by the extension of the tension spring 42, but other points are substantially the same as those in FIGS. 4 and 7. It is. It goes without saying that this example and the one shown in FIG. 7 can be installed with the right and left sides reversed.

The example shown in Fig. 9 utilizes the rotational force of the spring, and the free ends of two arms 44 and 45, which are pivotally connected by a pin shaft 43, can be tilted by a ball joint or a pin shaft. Part of link 28 and other parts 2B', 2
8". A helical spring 46 is hung between the arms 44 and 45 to adjust the angle θ between the arms.
is biased in the direction of expansion. There is a shoulder 47 near the pivot point of the arm, and the angle θ is suppressed below a certain value. Since the operation in this case can be easily understood by referring to the example shown in FIG. 4, detailed explanation will be omitted.

In the embodiments described above, the accelerator lever 27 is used as the basic external control means for adjusting the fuel injection timing, but in other examples, the accelerator lever 27 is automatically expanded according to the engine rotation speed. It may be a centrifugal governor with a diameter or an operating handle that allows the injection timing to be adjusted manually.

〔Effect of the invention〕

Since the present invention has the above-described structure and operation, in normal operating conditions, the fuel injection timing is adjusted by an external control means such as an accelerator lever, but only in the case of starting, the fuel injection timing is adjusted in conjunction with the starter. By applying a special operating force to the link mechanism, the fuel injection timing can be advanced unconditionally.In this case, the idle movement mechanism works and the special operating force is applied to the external control means. Therefore, the setting value of the external control means is not affected, and the injection timing is exceptionally advanced to facilitate starting. Therefore, for the target engine, both high performance during normal operation and ease of starting during startup can be obtained.

Furthermore, the configuration is extremely simple, and it is possible to use purely mechanical means that are less prone to failures, resulting in significant cost reductions compared to computer-controlled systems.

[Brief explanation of the drawing]

1 to 6 show an embodiment of the present invention,
Fig. 1 is a plan view of the fuel injection pump, Fig. 2 is a longitudinal side view thereof, Fig. 3 is a front view thereof, Fig. 4 is a longitudinal sectional front view of an example of the idle movement mechanism which is the main part, Fig. 5 and FIG. 6 is a partially enlarged view showing the operation of the control sleeve in the fuel injection pump, which is another important part. Further, FIGS. 7 to 9 each show other embodiments of the idle motion mechanism, with FIGS. 7 and 8 being longitudinal sectional front views, and FIG. 9 being a front view. Furthermore, FIG. 10 is a diagram showing an example of the operation of the present invention. ! Figure s2... Fuel injection pump, 5... Plunger,... Fuel storage chamber, 12... Control sleeve, 4... Lead hole, 15... Lower end edge, 7... Hole, 9 ...Fuel injection timing adjustment shaft, 2...Pin, 24...Fork, 6...
- Lever 27... Accelerator lever 8... Link, 29... Idle movement mechanism, 0... Solenoid, 0'... Protrusion, 34, 42, 46... Spring.

Claims (1)

[Claims] a control sleeve that is fitted into the plunger of the fuel injection pump and movable in the axial direction of the plunger in order to adjust fuel injection timing; and a control sleeve that is movable in the axial direction of the plunger to adjust the timing of fuel injection; a series of link mechanisms that connect a series of link mechanisms, a lost motion mechanism inserted into a part of the link mechanism, and a lost motion mechanism that is attached to a part of the link mechanism on the side of the control sleeve when viewed from the lost motion mechanism and that is connected to at least the starter. 1. A fuel injection timing control device for an internal combustion engine, comprising: an actuating device that interlocks with the fuel injection timing to advance the fuel injection timing.