JPS6032022B2 - Fuel injection pump control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a fuel injection pump, and more particularly to a connection structure between a fuel injection pump and an electronic governor for controlling the fuel injection pump.

This is a so-called Bosch-type fuel injection pump, which pumps fuel by reciprocating the plunger within the barrel, and adjusts the fuel injection amount by moving the rack back and forth.
When controlling with a speed governing mechanism that changes the amount of movement of its actuator according to the engine speed, such as a centrifugal governor or an electronic governor, the metering characteristics of the fuel injection pump should be adjusted to match the load characteristics of the engine. It is desirable to set it as follows.

In other words, when the normal engine speed is in a relatively high speed range, the metering characteristics of the fuel injection pump are adjusted so that the displacement of the actuator of the speed mechanism is most sensitively transmitted to the rack rod near the maximum fuel injection amount. On the other hand, when the normal rotation speed is relatively low, the metering characteristics of the fuel injection pump are adjusted so that changes in the actuator of the speed governing mechanism are transmitted to the rack rod most acutely near the minimum fuel injection amount. It is desirable that the However, in the conventional control device for this type of fuel injection pump, the rack rod and the actuator are connected by an appropriate connecting member so that the amount of displacement of the actuator and the amount of displacement of the rack rod, that is, the fuel injection amount, are always proportional to each other. Because they were connected, there was a problem in that it was not possible to control the fuel injection amount in accordance with the load characteristics of the engine.

In view of the above-mentioned problems, the present invention makes it possible to control the fuel injection amount in accordance with the load condition of the engine by transmitting the displacement of the actuator sensitively or insensitively to the rack rod according to the fuel injection amount. The purpose of this study was to propose a control device for a fuel injection pump that uses the following methods. below,
The present invention will be explained based on the embodiment shown in FIGS. 1 to 5. In FIG. 1, reference numeral 1 denotes an iron bag in which a barrel 3, a plunger 4, a plunger rotation wheel 5, a cam roller 6, etc. are housed in a pump casing 2. Fuel is pumped by reciprocating the plunger 4 within the barrel 3, and a rack rod 7 is disposed so as to mesh with a pinion gear 5a provided on the plunger rotation wheel 5, and the plunger 4 is moved forward and backward by the rack rod 7. This is a so-called Bosch-type fuel injection pump that adjusts the amount of fuel injection by changing the timing of the passage between the shield 35 provided on the top side of the barrel 3 and the oil escape hole 36 provided on the inner peripheral surface of the barrel 3. The fuel injection pump 1 passes through the cylinder block wall 31 and is attached to the outer surface of the cylinder block wall 31 by its mounting flange 43 so that the rack rod 7 is located inside the cylinder block wall 31.

Next, the control device for the fuel injection pump 1 of the illustrated embodiment will be explained. This fuel injection pump 1 has an electronic governor 29 as a main control member, in which a rack rod 7 for controlling the fuel injection amount is attached to the outer surface of the cylinder block wall 31. Further, the rack lever 7 is moved forward and backward using a centrifugal governor 33 as an auxiliary control member.

The electronic governor 29 receives an electric signal such as a voltage or a pulse according to the engine speed from an electric engine speed detector (not shown), and controls its actuator 3 according to the electric signal.
In the illustrated embodiment, the displacement of the actuator 30 of the electronic governor 29 is always transmitted to the rack rod 7.

i.e. cylinder tub. In order to interlock the rack rod 7 located inside the cylinder block wall 31 with the electronic governor 29 located outside the cylinder block wall 31, it is rotated through the cylinder block wall 31 in a direction parallel to the barrel axis of the fuel injection pump 1. A moving shaft 20 is provided. A cylindrical post material 2 attached to this spread shaft 2 passes through the cylinder block wall 31.
It is rotatably supported within 1 by needle bearings 22, 22. Further, at one end 20a of the rotating shaft 20 that protrudes outward from the cylinder block wall 31, there is a rotating arm 2 that serves as a connecting member for connecting to the actuator 301 of the electronic governor 29.
3 is fixed. This rotating arm 23 is made of a plate material of an appropriate size, and one end 23a of the rotating arm 23 is provided with an operating lever 2, which will be described later.
A guide groove 24 is provided in which a pin-shaped slider 25 provided at 6 is slidably inserted with iron. Operation lever 26
is composed of a plate material with one end thereof having two-pronged clamping portions 27 with an appropriate interval, and the other end 26a of which is an actuator 30' of an electronic governor 29 disposed parallel to the advancing and retreating direction of the rack rod 7. It is attached vertically with a tightening bolt 28. Therefore, the operating lever 26 moves the rack rod 7 along with the forward and backward movement of the actuator 30.
The holding portion 2 is moved horizontally in parallel with the advancing and retreating direction of the
The rotary arm 23 engaged with the slider 25 provided at 7 is moved, thereby causing the rotary shaft 20 to rotate in the direction of the arrow V-W shown in the figure. In the illustrated embodiment, the slider 2
The rotating arm 23 and the operating lever 2 are connected to each other by 5.
6 and one end 2 of the electronic governor 29 and the rotation shaft 20.
It constitutes a lever joint (outer lever joint) 8 between the outer lever joint and the outer lever joint 0a. On the other hand, a lever joint (inside lever joint) 18 having a spherical slider 17 in the middle is attached between the other end 20b of the rotary shaft 20 and the rack rod 7, and the rotary hoe 20 rotates. The rack rod 7 is moved forward and backward by dynamic operation.

The inner lever joint 18 includes a substantially U-shaped guide member 11 fixed to one end 7a of the rack rod 7, and a spherical slider 17 that is slidable in the vertical direction within the guide portion 11 at one end 19b. It is composed of a lever member 19 made of. Further, the lever member 19 has the other negative end 19a as a mounting boss portion, and is attached to the negative end 20b of the rotation shaft 20. Therefore, the lever member 19 is rotated in an arc with the rotation of the rotation shaft 20, and the slider 17 at the tip thereof is slid in the vertical direction within the guide member 11 to perform an arcuate movement, thereby moving the rack rod. 7 moves forward and backward. That is, the displacement of the actuator 30 of the electronic governor 29 is directly transmitted to the rack rod 7 via the connecting member 9 consisting of the outer lever joint 8, the rotation shaft 20, and the inner lever joint 18. In the illustrated embodiment, the rotating arm 23 and the bar portion 19 attached to both ends 20a and 20b of the rotating shaft 20 of the connecting member 9 extend in opposite directions with respect to the rotating shaft axis. By appropriately moving the electronic governor 29 in the front-back direction and changing its relative position with the rotating shaft 20,
The rotating arm 23 can be rotated in an arc on either the front or rear side of a perpendicular line drawn from the axis of the rotating shaft 20 to the axis of the actuator 30. On the other hand, a centrifugal governor 33 is connected to the rack rod 7 through a protrusion 1, a bar 12, and a lever 16, and a centrifugal governor 33 is connected to the lever 12 only when the engine speed increases abnormally. The end of the elongated hole 13 and the protrusion 10 engage with each other, thereby acting to move the rack rod 7 in a direction in which the amount of fuel to be injected decreases.

Next, the operation of the control device for the fuel injection pump of the illustrated embodiment will be explained with reference to FIGS. 2 to 5.
is reciprocated within the barrel 3 to forcefully send fuel to the fuel injection valve through the delivery valve 49, and the injection amount is constantly controlled by the electronic governor 29.

That is, when the engine speed decreases, the actuator 30 of the electronic governor 29 retracts, thereby moving the rack rod 7 in the direction of the arrow X in the figure, increasing the amount of fuel injection and restoring the engine speed to the set speed. do. Conversely, when the engine speed increases too much, the actuator 30 protrudes, causing the rack rod 7 to move in the direction of arrow Y, reducing the fuel injection amount and lowering the engine speed to the set speed.

At this time, as shown in FIG. 2, when the electronic governor 29 is moved so that its actuator 30 is at the maximum protrusion position, the rotating arm 23 of the connecting member 9 is centered from the axis of the rotating shaft 20 to the center of the actuator 30. If the rotating arm 23 is mounted so as to be positioned on the perpendicular line, the rotating arm 23 will rotate in an arc in front of the perpendicular line, and the more the actuator 30 protrudes, the more the rack rod 7 will be displaced in the arrow x-Y direction. The fuel injection rate increases, and the fuel injection amount suddenly increases or decreases near the maximum protrusion position (minimum fuel injection amount) of the actuator 30, as shown in FIG. Conversely, if the electronic governor 29 is arranged so that the rotary arm 23 of the connecting part village 9 is located on the perpendicular line when the actuator 30 is at the minimum protrusion position, as shown in FIG. is rotated in an arc on the rear side of the perpendicular line, and the smaller the amount of protrusion of the actuator 30, the greater the displacement rate of the rack rod 7 in the arrow x-Y direction,
As shown in FIG. 5, the fuel injection amount suddenly increases or decreases near the minimum protrusion amount (maximum fuel injection amount) of the operating element 30. That is, by appropriately setting the relative distance between the connecting member 9 and the electronic governor 29, the rate of increase/decrease in the fuel injection amount relative to the displacement amount of the actuator 30 can be maximized or This means that it can be set to the minimum. Next, to explain the effects of the present invention, according to the fuel injection pump control device of the present invention, the actuator 30 of the electronic governor 29
The rotating arm 23 of the connecting member 9 connected to the connecting member 9 is rotated in an arc on either side of a perpendicular line drawn from the rotating shaft 20, which is the center of rotation of the connecting member 9, onto the axis 0 of the actuator 30. Since the displacement rate of the rack lever 7 of the fuel injection pump 1, that is, the rate of increase/decrease in the fuel injection amount is maximized or minimized near the maximum injection amount position or the minimum injection amount position, the engine load characteristics In addition, the actuator 3 is more sensitive near the maximum injection amount position or the minimum injection amount position.
This has the effect that zero displacement can be transmitted to the rack rod, and the fuel injection amount can be precisely and quickly controlled in accordance with the load characteristics of the engine.

[Brief explanation of drawings]

FIG. 1 is a partially sectional perspective view of a fuel injection pump control device according to an embodiment of the present invention, and FIG. 2 is an explanation of the operation of the fuel injection pump control device shown in FIG. 1 in a first relative positional relationship. 3 is an explanatory diagram of the operation of the fuel injection pump control device in the case of FIG. 2, and FIG. 4 is an explanatory diagram of the operation of the fuel injection pump control device in the second relative positional relationship shown in FIG. 1. , FIG. 5 is an explanatory diagram of the operation of the fuel injection pump control device in the case of FIG. 4. 1... Fuel injection pump, 3... Barrel, 4...
Plunger, 7... Rack rod, 8... Bar joint, 9... Connection member, 11... Guide member, 1
4...Guide groove, 17...Slider, 18...
...Lever joint, 20...Rotation shaft, 20a, 20b
...Rotation shaft end, 23... Rotating arm, 24...Guide groove, 25...Slider, 29...Electronic governor, 30...
... Actuator, 31... Cylinder block wall, 35... Lead 36... Oil escape hole. Figure 3 Grave S Figure 2 Figure 4

Claims (1)

[Claims] 1 Inside the barrel 3 having an oil escape hole 36 on the inner circumference, the plunger 4 having an oil escape lead 35 on the outer circumferential surface is reciprocated to forcefully feed fuel, and the plunger 4 is rotated by moving the rack rod 7 back and forth. The fuel injection pump 1 is configured to change the communication timing between the oil escape hole 36 and the lead 35, thereby changing the fuel injection amount, so that the rack rod 7 is located inside the cylinder block wall 31. An electronic governor 29 is attached to the cylinder block wall 31 and arranged outside the cylinder block wall 31 so that the amount of movement of the actuator 30 changes according to the amount of electricity that changes according to the engine speed. Further, the rack rod 7 of the fuel injection pump 1 and the actuator 30 of the electronic governor 29 are guided to both ends 20a and 20b of the rotating shaft 20 passing through the cylinder block wall 31 to one end thereof. A rotating arm 23 having a groove 24 and rotating in an arc together with the rotating shaft 20, and a slider 25 sliding in the guide groove 24 of the rotating arm 23 on one end thereof, and the electronic type A lever joint 8 consisting of an operating lever 26 that converts the advance and retreat of the governor actuator 30 into an arc rotation of the rotation arm 23, a slider 17 that is rotated in an arc by the rotation shaft 20, and the slider The mover 17 is inserted into the guide groove 14 and connected by a connecting member 9 which is constructed by attaching a lever joint 18 consisting of a guide member 11 that is moved in the horizontal direction as the slider 17 rotates in an arc. On the other hand, the rotary arm 23, which is rotated in an arc as the actuator 30 of the electronic governor 29 advances and retreats, is placed in front of a perpendicular line drawn from the axis of the rotary shaft 20 to the axis of the actuator 30. A control device for a fuel injection pump, characterized in that the control device is configured to rotate in an arc on either side of the rear.