JPS5936663Y2 - Fuel injection pump control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of an electric fuel injection pump control device for a diesel engine.

Diesel engines have come to be used in general passenger cars due to their economic efficiency in fuel costs, but there are problems with their drivability, and improvements are desired.

One of these is improving the responsiveness of the fuel injection pump control device.

FIG. 1 is an explanatory diagram of a conventionally proposed fuel injection pump control device.

Pneumatic governor 2 attached to injection pump 1
The inside of the control chamber 4 is divided into two parts by a diaphragm 3, and a venturi 16 of a control valve 15 is connected to the control chamber 4 through a control pressure connection port 5.
Negative pressure generated in is introduced.

The control valve 15 changes the rotational state of the engine.
The control valve 1 is activated by the accelerator pedal 18 operated by the driver.
The amount of air sucked through the control valve 15 is changed by adjusting the opening degree of the control valve 7.

At this time, the negative pressure of the venturi 16 changes in proportion to the amount of intake air.

At the diaphragm 3 of the pneumatic governor 2, there is a control rack 10 that determines the amount of fuel to be injected and a rack end 11.
connected via.

A relatively large coiled compression spring 8 with one end in contact with the diaphragm 3 is housed in the control chamber 4.
The diaphragm 3 and the control rank 10 connected thereto are always pushed to the left.

When the opening degree of the throttle valve 17 is increased to increase the amount of air intake from the control valve 15, the negative pressure in the venturi 16 decreases, so the pressure in the control chamber 4 increases, and the control rack 10 is moved to the left to initiate injection. Increase fuel amount.

On the contrary, when the opening degree of the throttle valve 17 is small, the negative pressure in the venturi 16 increases and the pressure in the control chamber 4 decreases, so the diaphragm 3 resists the spring force of the compression spring 8. Pulling the control rack 10 to the right reduces the amount of fuel injected.

In this way, diaphragm 3 and control rack 1
0 moves to the left in proportion to the pressure in the control chamber 4 (that is, in proportion to the intake air amount of the control valve 15), but its maximum movement is limited by a stopper 12 installed opposite the rack end 11. be done.

Further, when moving to the right, the rack end 11 is restricted to a position where it comes into contact with the tip of the plunger 6 installed on the wall of the control room 4 via a small coil spring 7.

In the middle, the diaphragm 3 is in a position where the negative pressure in the control chamber 4 and the spring force of the compression spring 8 are balanced, and the position changes depending on the operating state of the engine.

Note that the spring force of the compression spring 8 is selected so that the position where the diaphragm 3 is restricted by the plunger 6 provides the injection amount during no-load operation of the engine.

The stop cam 12 is held in the Y' position during normal operation by a spring device (not shown), but can be moved to the X' or Z' position by external operation.

The X' position is the position at which a larger amount of fuel is supplied at start-up than the normal maximum injection quantity, and the Z' position is when the engine is stopped by cutting off the fuel supply.

At this Z' position, the coil spring 7 is compressed and the plunger 6 is forcibly pressed.

The rotation shaft of the stopper cam 12 is connected to the rotation shaft of an external operating lever 21, and the operating lever 21 is rotated in X, Y, and Z by rotation of a rotating arm 23 via a rod 22.
Become located in the direction.

The rotary arm 23 is rotated by an intermittent drive mechanism described below, and is positioned at three positions, a start control position 24, an operation control position 25, and a stop control position 26, as necessary.

That is, when the rotating arm 23 is at the operation control position 25 as shown in the figure, the operating lever 21 is at the Y position and the stopper cam 12 is at the Y' position.

Similarly, when the rotating arm 23 is in the start control position 24, it is in the x and x' positions, and when it is in the stop control position 26, it is in the z,
The position will be z'.

If the rotating arm 23 is rotated in the direction of the arrow, operation control position 25 → stop control position 26 → (operation control position)
→ Start control position 24, but it is always rotated in the same direction in this way and is driven by the Geneva mechanism described below.

The rotating arm 23 is attached coaxially with an intermittent drive mechanism using a Geneva cloth 35 and a three-position detection plate 42, and is rotated intermittently.

That is, the worm wheel 31 with the drive roller 32 installed
When the worm wheel 30 is rotated by a worm 30 attached to the rotating shaft of the motor 29, the drive roller 32 fits into the groove 36 of the Geneva cloth 35, and as the worm wheel 31 rotates once, the Geneva cloth 35 is rotated by %.

Therefore, the rotating arm 23 and the three-position detection plate 42 also rotate by %.

A lock land 34 having an arcuate relief portion 33 is coaxially fixed to the worm wheel 31, and a concave portion 37 of the Geneva cross 35 engages with a circular portion of the lock land 34, thereby preventing rotation of the Geneva cross 35. .

Since the worm wheel 31 is rotated in the direction of the arrow, the lock land 34 also rotates, and the driving roller 32 is fitted into the structure 36 at point A, and the Geneva cross 3 is rotated to point B.
Rotate 5.

At this time, the relief portion 33 of the lock land 34 allows the Geneva cross 35 to rotate in the direction of the arrow, and the end point C of the lock land 34 is located between the center of the Geneva cross 35 and the worm wheel 3.
1, the Geneva cross 35 can be rotated in the direction of the arrow thereafter.

That is, with one rotation of the worm wheel 31, the Geneva cross 3
5 is rotated by the reciprocal of the groove portion 36, and the Geneva cross 35 is stationary except when rotated.

In this way, the intermittent drive mechanism using the Geneva mechanism allows each control device to be accurately determined, making it easy to intercept the operation conversion parts such as part of the lever, and warming up the burden functions at each stop position. 30 and the worm wheel 31 can be provided.

Further, there are advantages such as the fact that the stop position of the motor does not need to be accurate.

3-position detection plate 4 installed coaxially with Geneva Cross 35
The shaded part 2 is a non-conducting part that fits within the insulating material.

The starting position brush 43, the operating position brush 44, and the stop position brush 45 are provided at positions corresponding to the starting control position 24, the operation control position 25, and the stop control position 26 of the rotary arm 23, respectively. Common brush 46
The brush in the non-conducting state selects the control position of the rotary arm 23.

In the figure, the operation control brush 44 is in a non-conducting state with the common brush 46.

Note that below this three-position detection plate 42, there is a fixed-position detection plate 47 attached to the rotating shaft of the worm wheel 31.
The other end of the common brush 46 is in contact and is in a conductive state.

As mentioned above, when the drive roller 32 rotates to the 8th position, point D is located at the deepest part of the recess 37 of the Geneva cross 35, so it is necessary to further rotate the worm wheel 31 to bring it to the position shown in the figure. .

The fixed position detection plate 47 is provided for this purpose, and a portion thereof is a non-conducting portion.

The shaded non-conducting portion is always at the same rotational position as the relief portion 33 of the worm wheel 31, and when the brush 48 reaches the stop position as shown in the figure, the fixed position brush 48 is in contact with the non-conducting portion.

A power source 101 for auxiliary operation of the engine has its negative pole grounded, and its positive pole connected to a common terminal of an instruction switch 102 for selecting three positions of the intermittent drive device.

The common terminal of the instruction switch 102 is connected to the start instruction position 103, operation instruction position 104, and stop instruction position 1 as necessary.
It is possible to conduct with one of the three terminals of 05.

These three terminals are connected to a starting position brush 43, an operating position brush 44, and a stopping position brush 45, respectively.

One of the two terminals that excites and rotates the motor 29 is grounded,
The other end is connected to the common brush 46.

The positive pole of the flying power source 101 is connected to the fixed position brush 48.

In the illustrated state, the instruction switch 102 is in the operating position, the rotating arm 23 and the 3-position detection plate of the intermittent drive mechanism are in the operation control position, and the fixed position detection plate 47 is in the normal position.

Therefore, current from the power supply tends to flow from the path between the instruction switch 102 and the operation instruction position 104, but the diagonally shaded insulation portion of the three-position detection plate 42 prevents the current from flowing to the motor.

In addition, the path from the positive pole of the power source 101 to the fixed position brush 48, which is another path, is not formed by the diagonally shaded insulating portion of the fixed position detection plate 47 to the motor.

Now, let us consider the case where the instruction switch 102 is brought into conduction with the stop instruction position 105 from this state.

The current flows to the motor 29 via the positive pole of the power supply 101, the indicator switch 102, the stop instruction position 105, the stop position brush 45.3, the conductive part excluding the shaded part of the position detection plate 42, and the common brush 46 (the first current (assuming that a passage has been formed).

By the time the worm wheel 31 rotates and the drive roller 32 reaches point A, the insulating part of the fixed position detection plate 47 comes off the fixed position brush 48, and at this point the positive pole of the power supply 101,
A current path (referred to as a second current path) passing through the fixed position brush 48, the conductive part of the fixed position detection plate 47, and the common brush 46 is formed, but at this point, the current distribution is only divided into two, so there is no significant effect. do not have.

After the drive roller 32 passes point A, the Geneva cross starts rotating, and when it reaches point B, the Geneva cross stops rotating, but a little before this, the stop position detection brush 45 has an insulating part of the three position detection plate 42. are brought into contact with each other.

As a result, the first current path disappears, but the second current path remains formed and the motor continues to drive.

When the lock land 34 on the worm wheel 31 fully engages with the concave portion of the Geneva cloth 35, the insulating portion of the fixed position detection plate 47 comes into contact with the fixed position brush 48, and the second current path disappears, causing the motor 29 to rotate by inertia. Stop after.

The size of the insulating portion on the fixed position detection plate 47 is selected so that it will not come off the fixed position brush 48 due to the coasting.

Although not shown in the figure, in order to reduce coasting, the motor 2
It is known to short-circuit the two terminals of 9.

When the instruction switch 102 is selected to an arbitrary position, the insulating portion of the three-position detection plate comes into contact with the corresponding brush 43, 44, 45, and the insulating portion of the fixed-position detection plate comes into contact with the fixed-position brush 48. It will be understood from the above description that the position where the motor continues to drive until the rotation arm 23 stops corresponds to the selected position of the instruction switch 102.

As described above, in the conventional fuel injection pump control device, since the Geneva mechanism has only one drive roller 32, the Geneva cloth 35 only rotates by % for one rotation of the worm wheel 31.

Therefore, the operation lever 21 is moved to the operating position x, y, z
It takes time to move the injected fuel to the desired position, and the injected fuel amount has a low degree of coordination.

For example, when it is necessary to stop a car in an emergency, it takes time to stop the fuel being supplied to the engine, and from the viewpoint of safety, there has been a desire to shorten this time.

The purpose of the present invention is to provide a control device for a fuel injection pump that is suitable for increasing the responsiveness of changes in operating conditions of a diesel engine. The Geneva cross is rotated multiple times per revolution of the worm wheel of the Geneva mechanism provided to select one of the three states, thereby reducing the time required to select one of the three states.

FIG. 2 is an explanatory diagram of a fuel injection pump control device which is an embodiment of the present invention, and the same parts as in FIG. 1 are given the same reference numerals.

The worm wheel 31 is provided with two driving rollers 32 in the diametrical direction, and the lock land 34 has two relief portions 33 in the diametrical direction.

Further, the fixed position detection plate 47 is 9
Two non-conducting parts are provided at positions shifted by 0'.

When the motor 29 rotates, the drive roller 32a engages with the groove 36 of the Geneva cloth 35 and rotates, causing the Geneva cloth 35 to rotate.
Rotate by % to make a withdrawal.

When the worm wheel 31 further rotates by half a rotation, the other drive roller 32b similarly rotates the Geneva cross 35 by 1/2 turn.

At this time, the non-conducting portions provided at two locations on the fixed position detection plate 47 come into contact with the fixed position brush 48, and the brush stops at the relative position shown in FIG.

The wiring is the same as in the case of one drive roller described above, and basically the non-conducting portion of the three-position detection plate 42 contacts the brush 43, 44, 45 corresponding to the selected position, and It is easy to understand that the rotation continues until the non-conducting portion of the fixed position detection plate 47 comes into contact with the fixed position brush 48.

Therefore, the Geneva cross 35 is rotated by X every time the worm wheel 31 makes a half turn, so
It becomes possible to operate the operating lever 21 in the time of , and the fuel supply amount of the fuel injection pump can be changed quickly.

Further, since the highly accurate rotational positioning function of the Geneva mechanism can be fully utilized, the control position can be determined accurately with coordination.

The control device of this embodiment achieves coordination for changing the amount of injected fuel by a relatively simple modification of providing two relief parts for the drive roller of the worm wheel, two relief parts for the rock land, and two non-conducting parts for the fixed position detection plate. It has the effect of being able to double the improvement.

The embodiment shown in FIG. 2 is a case where the main parts related to the correspondence of the injected fuel amount are reduced to two as described above, but if these main parts are further increased to three or four, The connectivity is further 3
It is possible to improve the performance by a factor of two or four.

The diesel engine fuel injection pump control device of the present invention has the effect of improving drivability through relatively simple modification.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional fuel injection pump control device, and FIG. 2 is an explanatory diagram of a fuel injection pump control device that is an embodiment of the present invention. 2...Pneumatic cabana, 3...
Diaphragm, 4... Control room, 10...
・Control rack, 12... Stop cam, 15... Control valve, 17... Throttle valve,
18... Accelerator pedal, 21... Operation lever 23... Rotating arm, 24...
・Start control position, 25... Operation control position, 26
...Stop control position, 29...Motor,
30... Worm, 31... Worm foil, 32... Drive roller, 33...
・Escape Department, 34...Rockland, 35...
...Geneva Cross, 36... Groove, 37...
...Recessed portion, 42...3 position detection plate, 43.
...Start position brush, 44...Operating position brush, 45...Stop position brush, 46...
...Common brush, 47...Fixed position detection plate,
48...Fixed position brush.

Claims (1)

[Claims for Utility Model Registration] Fuel for controlling the fuel injection pump into one of three states, starting operation and stopping, by controlling the position of a control rack provided on the fuel injection pump that supplies fuel to a diesel engine. Injection pump control device
A plurality of drive rollers 32a are arranged at equal angular intervals.
, 32b and a lock land 34 having a relief portion 33 facing each of the drive rollers 32a, 32b, and a worm wheel 31 that is connected to a stopper cam 21 that determines the position of the control rack and the drive roller 32.
The drive roller 32a rotates in synchronization with the worm wheel 31 and detects the state in which the Geneva cross 35 and the worm wheel 31 are disengaged. a fixed position detection plate 47 having the same number of non-conducting parts as 32b at equal angular intervals; and a three-position detection plate 42 having a non-conducting part that rotates in synchronization with the Geneva cross 35 and detects the position state of the Geneva cross 35. , When a terminal instructing one of the three states of start, operation, and stop is selected, the combination of the fixed position detection plate 47 and the three position detection plate 42 rotates the worm wheel 31 to the selected state. A fuel injection pump control device consisting of a motor 29.