JPS6338618A - Variable mechanism for advance timing characteristic of timer in fuel injection pump - Google Patents

Abstract

PURPOSE:To easily control the fuel injection timing, by longitudinally movably mounting a spring receiver of a timer spring and providing a control means which longitudinally moves the spring receiver. CONSTITUTION:A timer spring 5 mounts to its spring receiver 8 a rod 13, and the rod 13 is longitudinally movably mounted penetrating through a through hole 9a of a timer cap 9. A slide cam 10, which is adapted to the rod 13, is connected with a control handle, located in the vicinity of a driver's seat, through an operating arm 16 and a regulating lever 17. In this way, the fuel injection timing can be easily controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel injection pump for a diesel engine, and more specifically, to advance characteristics of a timer that controls fuel injection timing according to engine rotational speed. Concerned with variable mechanisms.

(Prior Art) FIG. 4 shows a conventional hydraulic timer operated by a pressure port of a feed pump controlled by a regulating valve. It is installed in the timer spring chamber 32 at right angles to the drive shaft 33 of the pump, and is activated within the timer chamber 32 by the balance between the change in the oil pressure and the spring force of the timer spring 34. Further, the timer piston 30 is coupled to a roller ring 35 rotatably attached to the drive shaft 33 via a slide pin 3G.

Therefore, although the timer piston 30 is always suppressed and biased in the direction of injection delay by the timer spring 34,
As the engine speed increases, the fuel pressure in the pump chamber increases.
When it is pressed, it is pushed against the timer spring 34,
the roller ring 35 in the rotational direction of the drive shaft 33;
In other words, the injection timing is advanced by rotating in the opposite direction to the pump rotation direction.

(Problem to be Solved by the Invention) However, the conventional timer described above has a structure in which the advance angle characteristics cannot be changed after assembly, and therefore engine vibration caused by improper adjustment of the fuel injection timing・!
; It was not possible to make adjustments to reduce the 4-tone sound.

In view of the above-mentioned problems, the technical problem of the present invention is to provide a timer with a function of changing advance angle characteristics.

(Means for solving the problem) The technical means for solving the above problem is to install the timer piston, which is operatively inserted into the timer chamber of the timer housing, so that it can rotate on the drive shaft. The timer screw 1 is moved by the balance between the change in the pressure oil in the timer chamber and the spring force of the timer spring to move the roller ring. In a timer for a fuel injection pump that rotates in an advance direction or a retard direction, the spring receiver of the timer spring is attached to the timer housing so as to be movable in the forward and backward directions, and the timer housing is equipped with an adjusting means for moving the spring receiver in the forward and backward directions. The timer advance angle characteristic variable mechanism was constructed using the following features.

(Operation) Therefore, by moving the spring receiver forward or backward through the adjustment means and changing the position of the timer piston through the timer spring, the advance angle characteristic of the timer can be changed.

(Example) Hereinafter, an example of the present invention will be specifically described based on the drawings. As shown in FIG. 1, a timer piston 3 is installed in a timer chamber 2 formed in a timer housing 1 so as to be perpendicular to a shaft 4 of a pump dryer. The fuel pressure in the pump chamber acts on the side, and the fuel pressure on the suction side of the feed pump acts on the opposite side. A timer spring 5 is housed in the timer chamber 2 on the feed pump suction side fuel pressure acting side, and the balance between the spring force of the timer spring 5 and the change in the hydraulic pressure acting on the timer piston 3 causes the timer piston to move. 3 is slid within the timer chamber 2. Further, the timer piston 3 is connected via a slide pin 7 to a roller ring 6 rotatably attached to the drive shirts 1 to 4. Therefore,
The timer piston 3 is normally pressed in the direction of injection delay by the timer spring 5, but when the engine speed increases and the fuel pressure in the timer chamber 2 increases,
It is pushed against the timer spring 5, thereby causing the roller ring 6 to rotate in the opposite direction to the rotational direction of the dry foot 11 foot 4, thereby advancing the injection timing.

Next, the advance angle characteristic variable #3 structure attached to the timer configured as described above will be explained. The spring receiver 8 that receives the timer spring 5 moves forward and backward into the timer chamber 2.
) + A slide housing 11 having a built-in slide cam 10 is fixed to the timer cap 9 on the timer spring housing side with bolts 12.

A rod 13 with a threaded portion at one end is attached to the spring receiver 8 via a nut 14.
3 passes through a through hole 9a formed in the timer cap 9 and extends to the slider housing 11 side, and its tip abuts against the slide cam 10. slide cam 10
The number of slides formed in the slide housing 11 is
The spring receiver 8 is housed in the spring support 5 so as to be able to move in a direction perpendicular to the advancing and retracting direction, and the vibrator, which is the contact surface with the rod 13, is set on the slope 10a, and the spring receiver 8 can be moved up and down across the slope 10a. A flange 10b is formed as a guide. Note that the tip of the a-rad 13 is the slide cam 1.
The slope corresponds to the slope 10a of 0.

Further, an actuation arm 16 is integrally connected to one end of the slide cam 10, and this actuation arm 16 extends to the outside of the slide housing 11 and is folded back into a substantially U-shape, and its QQ portion is The adjustment lever 17 is rotatably attached to the outer surface of the slide housing 11 via a pin 18 and is connected to one end of an adjustment lever 17 via a long hole 19 via a pin 20 . Note that this adjustment lever 17 is always urged counterclockwise in FIG. 3 by a torsion spring 21 arranged around the bottle. The adjustment lever 17 is connected to an adjustment handle 23 rotatably installed near the driver's seat via a bin 22 and a wire spring 2.
4 and wires 25. In addition, 26
27 is a wire stopper, and 27 is a locking threaded rod attached to a fixing nut 28 to fix the adjustment handle 23 in the adjustment position, the tip of which is attached to the 51w1 handle in the direction opposite to the 1-John spring 21. 2
It is designed to lock by coming into contact with a part of 3. On the other hand, in the timer chamber 2, a return spring 29 is housed on the pump chamber fuel pressure acting side so as to oppose the timer spring 5.

This embodiment is configured as described above, and therefore!
T! With the lock screw unlocked indoors, the adjustment lever 17 can be rotated against the torsion spring 21 via the wire spring 24 and the wire 25 by rotating the adjustment handle 23 clockwise as shown in the figure. When the slide cam 1 is moved, the slide cam 1 is
0 is moved, and the spring receiver 8 is advanced via the rod 13 by the slope 10a of the timer spring 5.
is pushed against the timer spring, and the roller ring 6 is rotated via the slide pin 7 in a direction to retard the injection timing.

On the other hand, when the adjustment handle 23 is rotated counterclockwise in the figure, the slide cam 10 moves in the opposite direction to the above due to the spring force of the spring 21. In this case, the return spring 29 is , the timer piston 3 and the timer spring 5 are moved backward, and the roller ring 6 is rotated via the slide pin 7 in a direction to advance the injection timing.

That is, the timer advance characteristic can be changed by moving the spring receiver 8 of the timer spring 5 forward or backward in a single chamber as described above, and after changing, the tip of the locking threaded rod 26 can be changed. By abutting against the adjustment handle 23, it can be held in the adjustment position.

In this embodiment, the adjustment operation for changing the timer characteristics can be performed inside the vehicle compartment, but it may also be performed inside the engine compartment, that is, near the fuel injection pump. Further, as a means for locking in the adjusted position, it is possible to change the method using the illustrated locking screw 26 to the method described above.

(Effects of the Invention) As described above, according to the present invention, the timer drift characteristic can be changed as desired by moving the spring receiver of the timer spring forward or backward, so that it is possible to change the timer drift characteristics as desired. This can be easily adjusted in the 11th gear, and it is also possible to improve ride comfort by adjusting the engine vibration and grinding noise of the J5 engine, especially during idling.

[Brief explanation of drawings]

Fig. 1 is a front cross-sectional view showing an embodiment of the variable timer characteristic mechanism for a fuel injection pump according to the present invention, Fig. 2 is a side view of the variable timer characteristic mechanism, and Fig. 3 shows the relationship between the slider cam and the spring receiver. FIG. 4 is a front sectional view showing a conventional timer. 1...Timer housing 2...Timer chamber 3...
Timer piston 4... Drive shift V 1-5...
・Timer spring 6...Roller ring 7...Slide pin 8...Spring receiver 10...Slide cam 11...Slide housing 13...Rod
16... Actuation arm 17... Lever
23...Adjustment handle 27...Threaded rod for lock Applicant Toyota Industries Corporation Representative Patent attorney Hidehiko Okada (3 others) Figure 1 Figure 2

Claims (2)

[Claims] (1) A timer piston slidably fitted into a timer chamber of a timer housing is interlocked with a roller ring rotatably mounted on a drive shaft via a slide pin, and the timer piston is slidably fitted into a timer chamber of a timer housing. In a fuel injection pump timer that rotates a roller ring in an advance direction or a retard direction by moving it depending on the balance between the change in pressure oil and the spring force of a timer spring, the spring receiver of the timer spring is attached to the timer housing. A timer advance angle characteristic variable mechanism for a fuel injection pump, which is mounted so as to be movable forward and backward, and is equipped with an adjusting means for moving a spring receiver forward and backward in a timer housing. (2) The adjustment means for moving the spring receiver forward and backward includes a rod protruding from the spring receiver, a slide cam slidably abutted on the end face of the rod, and an adjustment lever linked to the slide cam. and an adjustment handle that is operably attached to the driver's seat and connected to the adjustment lever via a wire, and a locking member that fixes the spring receiver at the adjustment position. A mechanism for variable timer advance angle characteristics in fuel injection pumps.