JPH02264149A - Pre-stroke control system for fuel injection device - Google Patents

Abstract

PURPOSE:To prevent fluctuation of pre-stroke position by attaching a balance weight which has the center of gravity at the side of counter-timing sleeve with respect to the axial line of a timing rod in a timing sleeve driving system. CONSTITUTION:When a pre-stroke actuator is operated, a shaft 41 is rotated and U-shaped link 40 is rotated around the center of a center axis C2 of a timing rod 26, then a timing rod 26 is rotated. Then, a pin 28 is rotated and a timing sleeve 14 is slid along a plunger 8, and pre-stroke position is changed. Vibration which is caused by engine operation, the sleeve 14 is liable to be actuated to the side of plunger shaft direction C1, but a balance weight 43 which balances with the sleeve 14 is attached to the rod 42 so as to move freely, so that the power is cancelled by the weight 43, and vibration which is transmitted to the timing rod 26 is absorbed. As a result, fluctuation of pre- stroke position is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a prestroke control mechanism for a fuel injection device.

(Prior Art) The prestroke control mechanism of a conventional fuel injection device includes a timing sleeve that is slidably attached to the plunger, and a timing rod that moves the timing sleeve up and down along the plunger. , the end of this timing rod is engaged with a prestroke actuator via an engagement member (Japanese Utility Model Publication No. Sho 61-118936).

As shown in FIG. 8, in the groove 40a of the O-shaped link 40, which is a retaining member, a ball 41a, which is an eccentric ball 41a, is engaged with the tip of the shaft 41 on the side of the brake stroke actuator.

In addition, as shown in FIG. 7, the timing rod body 23
A pin 28 is fixed with a lock screw 29, and the tip of the pin 28 fits into the groove 14b of the timing sleeve 14.
It is slidably fitted.

The timing sleeve 14 is attached to the timing rod body 23.
A screw hole 23a facing the is provided. The screw hole 23
In order to fix the pin 28 to the timing rod body 23, a lock screw 29 is inserted through a washer 30.
is screwed in. The outer periphery of the lock screw 29 is threaded and has a through hole 29a into which the rear end of the bottle 28 is inserted.

The pre-stroke actuator operates and the ball 41a
When the timing rod 2 moves, the timing rod 2
6 rotates. As the timing rod 26 rotates, the relative position of the plunger and control sleeve 14 changes, controlling the prestroke position.

(Problem to be Solved by the Invention) However, when considering the balance of the moment force of the weight of each part of the timing adjustment mechanism with respect to the timing rod operating axis, if the balance including the weight of the timing sleeve is not maintained, for example, the engine When the timing sleeve 14 is actuated or vibrations caused by the running of the vehicle are transmitted to the fuel injection device, the timing sleeve 14 vibrates in the plunger axial direction, causing the timing sleeve drive mechanism including at least the timing rod and the pre-stroke actuator to You can use a balance weight whose center of gravity is on the side opposite to the timing sleeve with respect to the axis of the timing rod.

(Function) Vibrations caused by engine operation, vehicle running, etc.
21 When the transmission is transmitted to the injection device, the timing sleeve is fitted into the plunger, so the inertia force acts to move the timing sleeve in the axial direction of the plunger. Since this is a benefit of the drive mechanism that includes the timing rod and prestroke actuator, the balance weight cancels out the force that attempts to move the timing sleeve in the plunger axial direction, and vibrations transmitted to the timing rod are absorbed.

(Example) An embodiment of the present invention will be described below based on the drawings.

The stroke position changes. As a result, dynamic fuel consumption, single injection timing, and fuel injection amount are adversely affected.
Deterioration of exhaust gas (increase in emissions, etc.) and engine l
・Various problems such as fluctuations in power occur.

The present invention has been made in view of the above circumstances, and provides a fuel injection device that can absorb vibrations of the timing sleeve in the plunger axial direction caused by vibrations from the engine side and prevent fluctuations in the prestroke position. The purpose is to provide a prestroke control mechanism.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention has a timing sleeve that is slidably attached to a plunger for changing a pre-stroke position, and the timing sleeve is moved up and down along the plunger. FIG. 1 shows a pre-stroke control mechanism of a fuel injection device in which a timing rod is rotatably mounted and a shaft of a pre-stroke actuator is connected to an end of the timing rod. FIG. 3 is an enlarged perspective view showing a prestroke control mechanism of a fuel injection device according to an embodiment of the present invention, and FIG. 3 is a longitudinal sectional view of the fuel injection device including the prestroke (-rotor control mechanism) viewed from the governor side.

In the figure, 2 is a housing of a fuel injection device, 4 and 5 are integral barrels held within the housing, and barrels 4, 5 are integral barrels held within the housing.
5 are located so that the axes of the housing 2 are aligned in parallel on one plane inside the housing 2. 6 is 1 of barrels 4 and 5. I'fl
+ (Delivery valve holder connected to each cylinder of the engine, 7a is the delivery valve,
8 is a plunger that is slidably inserted loosely into the barrels 4 and 5; IO is a spring that urges the plunger 8 downward; 1;
2 is a cam that is linked to a drive shaft of an engine (not shown) and pushes up the plunger 8; 14 is a timing sleeve that is slidably fitted around the outer periphery of the plunger 8; 16 is fixed to the barrel 5 and is engaged with the guide groove 17 of the timing sleeve I4; A guide pin 18, which also restricts rotation thereof, is a sleeve rotatably supported by the barrel 4 and non-rotatably engaged with the plunger 8.

The plunger 8 has an oil passage 8a that communicates between its upper end surface and the circumferential side, a circumferential groove 8b formed on the circumferential side communicating with the oil passage 8a, a vertical groove 8c along the plunger axis, and an oil passage 8b formed on the circumferential side that communicates with the oil passage 8a. A control groove is formed by the grooves 8c, 8d and the circumferential side groove CI8b.On the other hand, the timing sleeve 14 has a control groove that defines the injection path. A hole is provided.

Reference numeral 15 indicates an oil reservoir chamber that stores fuel supplied from a feed pump (not shown), and since the plunger 8 is oil-tightly fitted into the barrel 5, the fuel does not leak into the camshaft chamber 13. Further, 21 is used for oil supply for supplying lubricating oil into the camshaft chamber 13. 26 is timing sleeve l
The timing rod is used to move the /I up and down along the plunger 8, and is a timing rod that can be freely rotated in a direction perpendicular to the plunger 8. As shown in FIG. 7, the timing rod 26 has screw holes 23a facing each timing sleeve 14 inserted into the timing rod main body 2.
3, and a washer 30 is provided in the screw hole 23a in the direction.

There are two balance weights 43 on the free end side of the rod 42.
As shown in FIG. 2, the fixed position of the balance weight 43 is such that it is practically equal to the moment generated by the total weight of the timing sleeves 1.4 (plurality) on the plunger 8 side from the center line C2 of the timing rod 26. The position Q1 is set to obtain a moment on the anti-plunger 8 side including . As a result of an experiment, the moment on the balance weight 43 side (the left side in FIG. 2) is 1 of the moment on the timing sleeve 14 side (the right side in FIG. 2), assuming that the center line C2 in FIG. It was found that it is effective if the value is 2 or more.

A 1-mm thread 42a is cut on the outer periphery of the rod 42 for the take-out τj, and a female thread 43a that engages with the female thread 42a is provided on the balance weight 43. Therefore, depending on the number of cylinders of the engine, variations in weight of individual parts, etc., the lock screw 29 is screwed in to fix the bottle 28.Lock screw 2
9 has a through hole 29a into which the rear end of the bottle 28 is inserted, and a thread 29b is cut on the outer periphery.

The tip of the pin 28 fixed to the timing rod body 23 by the lock screw 29 is attached to the timing sleeve 14.
It is slidably fitted into the groove 14b provided in the third
figure). Therefore, the bin 28 is the timing rod body 2
3 is transmitted to the timing sleeve 14, and the timing sleeve 14 moves up and down along the plunger 8.

The outer circumferential surface of the tip of the bottle 28 has a curvature that constantly contacts the inner circumferential portions of the grooves 1 and 4b to prevent rattling.

Furthermore, as shown in FIG. 1, a 0-shaped link (engaging portion) 40 is fixed to the end of the timing rod 26.

A ball 4 at the tip of a shaft 41 of a pre-stroke actuator (not shown) is located in the engagement groove 40a of the 0-shaped link 40.
1a is engaged.

The 0-shaped link 40 has a take-out (J rod 42) that adjusts Ql by rotating the balance way i. can do.

In the case of this embodiment, the timing sleeve drive mechanism is composed of the timing rod 26, the grease 1 to loak actuator, and the 0-shaped link 40, and the balance weight 43 is connected to the 0-shaped link via the I rod 42. It is 40 (-J).

In addition, the prestroke actuator includes a drive section and a prestroke position sensor section, and the drive section includes a coil, a core,
It is composed of a rotor and a shirt I-41, and when the coil is energized, a magnetic force is generated in the core, causing the rotor to rotate, and when the rotor rotates, the shaft 41 integrated with the rotor rotates.

Next, the operation will be explained.

Camshaft 1 that operates in conjunction with the rotational force from the engine drive shaft
2a, when the cam 12 rotates once, the roller 25a of the tappet 25 reciprocates the plunger 8 up and down by a constant lift amount in one direction, ie, one loaf, each time the roller 25a is pressed by the cam 12.

Here, the fuel injection process will be explained with reference to FIGS. 4(a) to 4(d) (assuming that the timing sleeves l/l are in the normal position). When the plunger 8 and the timing sleeve 14 are in the position shown in FIG. 4(a), that is, when the opening 8b is not yet closed by the timing sleeve 14, the pressure chamber 2° and the oil reservoir chamber 15 are not in communication. Therefore, fuel is not pumped. When the plunger 8 moves upward and the opening 81 is closed by the timing sleeve 14 as shown in FIG. Begin to.

When the plunger 8 further rises by -4- as shown in FIG. 4(C), the pressure in the pressure chamber 20 overcomes the spring force of the delivery valve spring 7b and the delivery valve 7a opens.
High pressure fuel 1 is fed under pressure. When the inclined groove 8d comes to face the control hole 14a as shown in FIG. The pressure inside the chamber 20 drops rapidly, and the pressure feeding ends.

In addition, since the timing sleeve 1 is an old one that can be removed freely when the brake stroke actuator operates,
4 in the plunger axial direction C1 is canceled out by the balance weight 43, and vibrations transmitted to the timing rod 26 are absorbed. As a result, the swing of the timing sleeve in the plunger axial direction C1 caused by vibration can be absorbed, and fluctuations in the prestroke position can be prevented.

In addition, in the two-unit embodiment, a case has been described in which the balance weight is attached to the zero-shaped link 40 of the timing sleeve drive mechanism via the ground utilization rod 42, but instead of this, as shown in FIG. The timing rod 26 is attached to the end of the zero-shaped link 40 on the side opposite to the timing sleeve.
As shown in FIG. 6, a balance weight 43 that protrudes largely in a direction perpendicular to the central axis C2 of the timing sleeve drive mechanism may be provided directly and integrally with the timing rod main body 23 that is a part of the timing rod 26 of the timing sleeve drive mechanism. Even if a thick plate-shaped balance weight 43 is screwed to the end face on the opposite side of the timing sleeve, the same effect as in the embodiment shown in FIG. 1 can be obtained. The link 40 is the central axis C of the timing rod 26
2, and the timing rod 26 rotates. When the timing rod 26 rotates, the pin 28 of the timing rod 26 rotates and the timing sleeve 14
slides along the plunger 8, and the prestroke position changes. When the timing rod 26 rotates in the counterclockwise direction, the timing sleeve l/1 slides downward (towards the cam 12), the blistering position changes to the small side, and the injection timing changes. On the other hand, when the timing rod 26 rotates in one direction, the timing sleeve j4
It slides in one direction (toward the delivery valve 7a side), the prestroke changes to the large side, and the injection timing becomes delayed.

For example, when vibrations caused by engine operation or vehicle running are transmitted to the fuel injection device, the vibrations cause the timing sleeve, which is fitted on the plunger 8, to not move in the plunger axial direction C+, but force is applied to it. However, the balance weight 43 that balances the timing sleeve 14 can be transferred to the rod 42.

(Effects of the Invention) As explained below, according to the pre-stroke control mechanism of the fuel injection device of the present invention, the timing sleeve for changing the pre-stroke position is slidably attached to the plunger, and the timing sleeve is attached to the plunger at 011. A timing rod is rotatably attached to be moved downward along the plunger, and pre-stroke control of the fuel injection device is formed by connecting the shirt I of the Bliss I loaf actuator and the end of the timing rod. In the mechanism, the timing sleeve drive mechanism including at least the IfiJ timing rod and the pre-stroke actuator is provided with a balance way 1~ having a center of gravity on the side opposite to the timing sleeve with respect to the axis of the timing rod. Therefore, when vibrations caused by engine operation or vehicle running, especially downward vibrations, are transmitted to the fuel injection system, the balance weight cancels out the force that tries to move the timing sleeve in the plunger axial direction. , it is possible to prevent variations in the bristloof position.

Therefore, there is an adverse effect on dynamic fuel injection timing and fuel injection amount, deterioration of υ1 gas (increase in emissions, etc.),
It is possible to prevent various problems such as engine torque fluctuations from occurring.

[Brief explanation of drawings]

FIG. 1 is an enlarged perspective view of a prestroke control mechanism according to an embodiment of the present invention, FIG. 2 is a side view of the brist rotor control mechanism, and FIG. FIG. 4 is a diagram for explaining the relationship between the plunger and the timing sleeve, and FIGS. 5 and 6 are diagrams of the pre-stroke control mechanism according to the embodiment of the present invention. FIG. 7 is an exploded perspective view of the timing rod, and FIG. 8 is an enlarged perspective view showing a conventional bliss/loaf control mechanism. 8. Plunger, 14... Timing sleeve, 14
b... Groove, 23... Timing rod body, 26...
Timing rod, 28-bin, 29... lock screw, 40... U-shaped sink, 4-tooth actuator side shaft, 41a... ball at the tip of shirt I, 42.
Rod, 42a・Oi (screw, 43・balance weight, 43a female thread.

Claims (1)

[Claims] 1. A timing sleeve that changes the prestroke position is slidably attached to the plunger, and a timing rod that moves the timing sleeve up and down along the plunger is rotatably attached, and the shaft of the prestroke actuator and the In a pre-stroke control mechanism for a fuel injection device that is connected to an end of a timing rod, a timing sleeve drive mechanism including at least the timing rod and the pre-stroke actuator has a timing sleeve opposite to the axis of the timing rod. A pre-stroke control mechanism for a fuel injection device characterized by a balance weight having a center of gravity attached to the side.