JPS6067765A - Single type fuel injection pump - Google Patents

Abstract

PURPOSE:To reduce the size of a fuel injection pump and improve the responsibility thereof by disposing an electrically operated actuator, having an output shaft which makes axial movement in the for and back directions, at one end of a control rack which controls fuel injection and arranging the output shaft coaxially with the control rack. CONSTITUTION:An equipment changes the fuel injection timing by axially moving a movable barrel 3 by the wedge effect of the inclined face 38a which is formed on one side of a pinion 38, namely. The inclined face 38a is thrusted between the pinion 38 and opposed inclined face 39a which is formed on the face of a barrel retainer 39 by the turn of the pinion 38. In such equipment, a barrel driving rack 37 meshes the pinion 38. And a stepping motor 55 is disposed as to have the output shaft 58 thereof coaxial with the rack 37. Said stepping motor 55 is controlled by the output signal fed from a control circuit and the output shaft 58 thereof is driven forth and back in the axial direction to move the output shaft 58. The output shaft 58 may move in the same direction the rack 37 which is loaded with a compression spring 62, whereby enabling the control of injection timing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection pump suitable for electronic control.

There are two types of fuel injection pumps used in diesel engines, etc.: in-line pumps, which have the same number of plungers as cylinders, and individual pumps, which are installed independently for each cylinder.In large engines, individual pumps are generally used. It is used. In this case, as the number of cylinders increases, the link mechanism that connects the governor and pump becomes longer and larger, and the mass also increases, so the governor also has a larger capacity and is larger. ◇Also, there are problems such as foreign objects getting caught. In the event that a plunger sticks due to trouble, it is necessary to urgently cut off the fuel in other cylinders, but it is difficult to deal with this problem properly using a conventional link mechanism. This was developed with the aim of providing an independent fuel injection pump that does not require a link mechanism and is easy to control simultaneously and individually. An electric actuator having an output shaft that moves forward and backward in the axial direction according to input signals is provided at one end K of the control rack for controlling the control rack, etc., so that the output shaft is located on the same axis as the control rack. As the electric actuator, for example, a stepping motor or a driving near solenoid is used.In other words, in the present invention, since the control rack is driven by an electric actuator, the microcomputer By adopting an electronic control method that utilizes the following, it is easy to perform simultaneous control or individual control, and since the control rack and the output shaft of the actuator are placed coaxially, space can be used effectively and the product can be made smaller. Furthermore, since the mass of the movable parts is reduced, it is possible to perform control with good responsiveness using a relatively small capacity actuator.

Hereinafter, the present invention will be specifically explained with reference to an illustrated embodiment. In this example, the barrel is divided into upper, middle, and lower parts to reduce the mass of the movable barrel for adjusting the injection timing, and a busy cam mechanism is adopted, and the control rack for adjusting the injection timing is made smaller. It can be operated by driving force, and the features of the present invention can be fully demonstrated.

In the figure, (1) is the crack of the bonder, (2) is the upper fixed barrel, (3) is the movable barrel, (4) is the lower fixed barrel, and (5) is the plunger. Upper fixed barrel (
2) and the lower fixed barrel (4) are fixed in the hack rack (1), and the movable barrel (3) is attached to each fixed barrel f21 +4
The grunger (5) is axially movably inserted into the housing +11 at an intermediate position between the two fixed barrels (2), (4) and the movable barrel (3). It is inserted so that it can be moved in any direction. (6) is a lubricating oil holding groove provided in the granger (6).

(7) is a plunger spring chamber formed in the lower part of the hack rack (1), (8) is a plunger spring, (9) is a tappet, and the tappet (9) is attached to the lower end of the plunger (5). The plunger chamber is compressed between the upper spring receiver (00) on the side of the plunger chamber (1) and the lower spring receiver (1) on the plunger (5) side, and the plunger (5) is moved upward by a cam (not shown). The plunger spring chamber (7) also contains a control binion (+41) that engages the control rank O and the control rack θ□□□. A control sleeve QI19 is provided with a groove S (φ) at the lower end of the control sleeve a.
By not moving the control rack wheel in the direction perpendicular to the plane of the figure, the control binion 041 rotates, and the plunger (5 ) is designed to rotate.

(I@ is the sliding direction guide pin that also serves as a rotation stopper for the rack 0 kun, and 輠 is the C-shaped lip to prevent the tappet from falling off.

(2]) surrounds the movable barrel (3).
1) Fuel oil chamber formed on the inner surface of the main body, @ is the movable barrel (3
) and the lower fixed barrel (4), the suction boat is formed in communication with the fuel oil chamber body υ, (2Il) is the spill boat formed in the movable barrel (3), and the company is the plunger (5). ) is a lead part having an escape hole communicating with the end face (5a) of the lead part. The suction boat (sha) is connected to the lead part (sha) when the plunger (5) is at the bottom, and the spill boat is connected to the lead part (sha) when the granger (5) is at the top.
It is located in such a position that it communicates with the That is, fuel is fed from the fuel filler port (not shown) to the fuel oil chamber body),
Suction boat when Granger (5) is near bottom dead center □
□□, the lead part (b), the plunger chamber formed by the plunger (5) and the upper fixed barrel (2) through the relief hole (2Q), and the plunger (5) moves to the ascending process and is supplied to the lead part. When the communication between the clitoris and the suction boat is cut off, pressure feeding starts, and the plunger (5) rises again, and when the door 5 (25i) communicates with the spill boat, the pressure feeding stops. The effective stroke of the plunger (5) corresponding to the fuel injection amount is determined by the control rack O1.
to change the position of the inclined upper part 79 (25a) of the lead part 4 with respect to the spill boat (24I).
Therefore, it is done. A delivery pulp ψ0 is provided at the top of the crack (1), and is urged downward by a delivery spring (9), and usually the pulp guide (
BaK is pressed closed, but when the granger (6) is raised and pumped, it opens against the spring 0, and fuel is injected through the pre/revipe (not shown) connected to the pulp holder 0. be done. This is a spill protector installed in response to spill boats.

Reference η is the rack for driving the barrel, Iguchi is the rank 7) Binion for driving the barrel that engages with Ic, (Incorporated)) is the annular barrel holder, (8) is the return spring, Binion (Incorporated) and Barrel holder @ The pinion is placed between the upper fixed barrel (21K formed step (2a) and the upper end surface (3a) of the movable barrel (3)), and the pinion (3 barrels and barrel presser extension 9). As shown in Figure 2, the contact area has a sloped surface (
38a) and (39a) are provided to constitute a surface cam button Iυ. Note that this surface cam mechanism uses a sloped wedge plug, and may be replaced with another mechanism such as a screw. The return spring member is interposed between the stepped portion (3b) of the movable barrel (3) and the lower edge (21a) of the fuel oil chamber (21), and biases the movable barrel (3) upward.

The barrel drive rack @7) is designed to move in the direction perpendicular to the plane of the paper in Figure 1, and by moving the rack, the barrel drive binion rotates, and the surface cam mechanism (41) rotates. Due to the wedge action of the inclined surfaces (38a) and (39a) K, the distance G between the Binion plate and the barrel presser (39) changes, and the movable barrel (3) moves in the axial direction. Therefore, the position of the upper R (22a) of the suction port (24) and the sub-bottle port changes with respect to the lead part (to) of the plunger (5), and the timing of starting and stopping the pumping changes. This makes it possible to change the injection timing.The barrel holder (3) and the movable barrel (3)K form axial grooves (39b) and (3c), respectively, and the guide pin (4ALL48) is used to prevent rotation. It has been given
In addition, the barrel presser (to) K is provided with a through hole (b) and a groove (
39b) The gap between the upper fixed barrel (2) and the movable barrel (3) is communicated with the fuel oil chamber body INK via (3c).

i4'7) is the lower fixed barrel (4) and I Kuzing (1)
), and hs is an oil supply passage provided in the lower fixed barrel (4). Refueling route t
he is open in the annular groove ←9) formed on the inner circumferential surface of the lower fixed barrel (4), and the other end is a crack (
It opens into the annular groove ←0) provided at +1, and is further connected from the check valve υ to a high-pressure supply source of lubricating oil (not shown) via a piping sister. That is, when the plunger (5) reciprocates up and down, lubricating oil is supplied to the circumferential surface of the plunger (5), and the lubricating oil retaining groove (6) of the plunger (5) reaches the annular groove ← 9) Lubricating oil is also supplied here,
When the sliding surfaces of the plunger (5) and the lower fixed barrel (4) are forcibly lubricated, a film of lubricating oil forms a seal between the fuel oil chamber η and the plunger spring chamber (7). . This, together with the action of the O-ring (4η), prevents fuel from leaking into the plunger spring chamber (7).

Note that the upper half of the plunger (5) is powered by fuel oil.

As mentioned above, the control rack θ is a control rack for controlling the amount of fuel to be injected, and the barrel drive rack G3η is a control rack for controlling the injection timing. The position IP' is adjusted by an actuator.

In FIG. 3, (5[i) is a stepping motor, and the rotation of the rotor (A) is converted into axial movement of the output shaft H via the screw connection (C) η. ) moves forward and backward in the axial direction according to the number of drive steps, and the tip of the output shaft - is brought into contact with one end of the rack (37), so that the output shaft 8) and the rank 7) are on the same axis. The mounting part -) is screwed into the mounting hole θO) of the rack fl) so as to be located on the line. The other end of the rack 07 is provided with a compression spring held by one of the combined spring receivers, biasing the rack 07) in the direction of the stepping motor.

With this configuration, the stepping motor (output shaft of 5119) advances and retreats in the axial direction in response to the output signal from the control circuit using a microcomputer, etc., and the rank 0η, which is energized by the compression spring, It moves in the axial direction following the end of the output shaft, and the barrel drive pinion rotates, moving the movable barrel fli1 as described above, and controlling the injection timing. Note that - indicates the output (2) is an air passage that connects the spaces at both ends of the rank η via the circumference of the binion, and (61 is a gasket).

In FIG. 4, the shaft is a linear shaft, and is provided with an output shaft (72) movable in the axial direction along a guide rod (70), and a movable core (72) connected to the output shaft (72).
73) is the electromagnetic force of the coil (74) (c) and the coil spring (
It moves in the axial direction in response to the repulsive force of the output shaft (741), and the output shaft (7) moves forward and backward in the axial direction according to the input signal to the coil (741). The tip is brought into contact with one end of Ratsuta Kasumi, and the output shaft (spring shaft C'7 extended from 7) is passed through the shaft hole (13a) of rack 03), and the end of the spring shaft (c) is inserted into the shaft hole (13a) of rack 03). A compression spring (79) is provided between the other end of the provided spring receiving plate V □ The output shaft (the mounting part - is screwed into the mounting hole 0111 of the rack fl) so that the output shaft and the rack track are located on the same axis. , @'4 is a screw cap, and A3) (84) is a gasket. Since it is configured in this way, the output shaft (72) advances and retreats in the axial direction in response to an output signal from a control circuit using a microcomputer, etc., and the rack (13) ld output is biased by the compression spring (79). The output shaft follows and moves in the axial direction, the control pinion (I4) rotates, the plunger (5) rotates as described above, and the fuel injection (1) is controlled.

This embodiment has the structure and function as described above, and is suitable for use with linear remade (70), which is an electric actuator, or D However, its output shaft (7η extension 8) is ranked (
1: H7), the overall length of the rack 0 0 0 η is short and the mass of the movable parts can be reduced, and the overall axial length including the actuator is short. The entire structure can be made smaller. In addition, since each output shaft ζ1J stem 8) is not directly mechanically connected to the rack 03), there is a large tolerance for misalignment of their axes, and processing and assembly are facilitated.

In particular, in Fig. 4, the structure is such that a compression spring (79) is provided at the tip of the spring shaft (C) that passes through the rack 03), so that the automatic spring between the output shaft (C) and the rack 0 rises. The centering effect is fully exerted, and frequent operations associated with tilting the governor operation can be performed more smoothly.

As is clear from the above embodiments, in the zero-start FJJ, the control rack is driven by an electric actuator, and its output shaft is arranged coaxially with the control rack 7 so that it moves forward and backward in the axial direction. Therefore, it is possible to obtain a fuel injection pump that is small, has good responsiveness, and can easily improve controllability by adopting an electronic control method.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of one embodiment of the present invention, Fig. 2 is a front view of the above surface cam mechanism, Fig. 3 is a cross-sectional view taken along line 8-A of Fig. 1-L, and Fig. 4 is a sectional view of It is a sectional view taken along the line B-B in the figure. +l)...Ha9 Sink s (+3)...Controller/L/Rack, o71...Barrel drive rack, Frame...Stamping motor, (5→...Output M, I7
0)...Linear solenoid, ID, (7ri...Output shaft 0
Patent applicant Yanmar Diesel Co., Ltd. Agent Patent attorney Shino 1) Minoru

Claims (1)

[Claims] (1) At one end of the control rack that controls the fuel injection amount or injection timing, an electric actuator is installed at one end of the control rack, and the output shaft advances in the axial direction according to the input signal. An independent fuel injection pump 0 characterized in that it is provided so as to be located on the same axis as the