JPS6145326Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a reduced-cylinder operation device for a multi-cylinder diesel engine, and more specifically, improves a distributed fuel injection pump to enable reduced-cylinder operation under light loads.

In recent years, in multi-cylinder diesel engines, when the engine load is light, the fuel supply to some cylinders is cut off and the remaining cylinders are operated, thereby improving overall fuel efficiency in the light load range. Reduced cylinder engines have been proposed.

Reduced-cylinder operation was designed based on the tendency for fuel efficiency to improve as the engine is operated under higher loads.By stopping the operation of some cylinders when the engine's full output is not required, the remaining cylinders can be reduced. Since the load on the active cylinder increases relatively, it is possible to improve fuel efficiency without impairing power performance.

By the way, in conventional engines like this, the inactive cylinder that stops operating during cylinder reduction operation and the active cylinder that is always active are usually limited in advance. In addition, the ignition timing of the cylinders on the operating side is set in an orderly manner and at equal intervals, thereby maintaining the balance of engine operation and performing reduced-cylinder operation.

However, this is only possible for engines with an even number of cylinders, and in the case of an engine with an odd number of cylinders, it is not possible to set the ignition timing of the active cylinder at equal intervals, so the number of cylinders can be adjusted in a well-balanced manner. It is becoming difficult to control.

For example, the firing order of each cylinder is #1-#2-#4
-#5-#3, and the ignition interval is expressed by the rotation angle of the crankshaft (hereinafter, expressed in the same manner).Since one rotation of the crankshaft is 360 degrees, the rotation angle of two rotations is divided into 5 equal parts. In the case of a 4-cycle in-line 5-cylinder diesel engine where the angles of the cylinders are 144 degrees each, if the operation of #2 and #5 cylinders is stopped (called cylinder reduction), the ignition order will be #1-#4. -#3
-#1-#4-#3, there is no problem, but
The ignition interval is #1-288°-#4-288°-#3-
144゜-#1-288゜-#4-288゜-#3, and no matter how hard you try, it is impossible to make them evenly spaced. Therefore, when operating with reduced cylinders, unpleasant vibrations can be avoided. I can't.

In view of these problems, the present invention makes it possible to control the number of cylinders by attaching a simple cylinder reduction device to a normal distribution fuel injection pump used in diesel engines, and in particular, it makes it possible to ignite even in engines with an odd number of cylinders. To provide a multi-cylinder diesel engine in which fuel is injected at equal intervals and easy cylinder reduction operation can be performed while keeping the engine well balanced.

Embodiments of the present invention will be described below with reference to the drawings, but first a general distribution type fuel injection pump in which the cylinder reduction device of the present invention is installed will be schematically described.

In FIGS. 1 and 2, the fuel sucked from the inlet 1 of the pump body by the feed pump 3 driven by the drive shaft 2 is transferred to the regulator 4.
After the supply pressure is controlled by
The fuel is sent to a high-pressure plunger pump 7 from a fuel intake port 6 provided on the inner wall.

In the high-pressure plunger pump 7, the plunger 8 is fixed to an eccentric disk 9, which is driven by the drive shaft 2 via a spline-like joint 2A.
and a roller 1 disposed on a roller ring 11.
Since the plunger 8 reciprocates by a predetermined cam lift while rotating over 2, the plunger 8 also rotates and reciprocates the same number of times as the number of cylinders per rotation.

Therefore, the fuel introduced through the guide groove 8A of the plunger 8 is pressurized by the reciprocating movement of the plunger 8 within the cylinder 7A, and then flows through the center passage 8B from the discharge port 8C of the rotating plunger 8. is supplied to the distribution port 13 facing the.

The distribution port 13 is formed in the pusher 13A,
As shown in FIG. 2, for example, in a 5-cylinder diesel engine, there are the same number of cylinders as the number of cylinders, that is, five locations, and radially around the outer circumference of the plunger 8.
And they are arranged so that the outer circumference is divided into five equal parts.

The fuel supplied to each distribution port 13 in order and at equal intervals is forced through the delivery valve 14 to an injection nozzle (not shown).

In this way, the fuel from the inlet 1 of the pump body is brought to a high pressure and is injected into each cylinder in sequence.

Furthermore, the amount of fuel to be injected is determined by the position of the spill ring 16 that covers the spill port 15 formed in the plunger 8. When the spill port 15 is opened by moving the plunger 8 to the right, high-pressure fuel is injected into the inside of the pump housing 5. to end the pumping.

The position of the spill ring 16 is controlled via the wrinkle bar 18 by the movement of a governor mechanism 17 driven by the rotation of the drive shaft 2, and the amount of fuel injection is increased or decreased in accordance with the engine speed.

This rotation of the drive shaft 2 is caused by the first and second rotations.
The speed is increased by the gears 19 and 20, and the governor mechanism 17
can be conveyed to. 21 is a governor shaft that supports the governor mechanism 17 and the second gear 20 axially.

FIG. 3 is a main part of the present invention, and functionally shows the cylinder reduction device of the present invention installed in a distributed fuel injection pump of a five-cylinder engine.

The center passage 8B formed in the plunger 8 of the high-pressure plunger pump 7 is made a deeper hole, and a hole is made in the plunger 8 from the outside at approximately the middle position between the spill port 15 and the eccentric disk 9 so as to communicate with the center passage 8B. A port 22 is formed.

The relief port 22 is the spill port 15
Similarly to the spill ring 16 for the spill port 15, a cylinder reducing sleeve 23 covering the relief port 22 is slidably and rotatably interposed in the plunger 8. equipped.

However, the detailed structure of the tube reduction sleeve 23 is as shown in FIG. E is formed so that its inner circumference is divided into five equal parts. The width of the relief grooves A to E in the circumferential direction is determined by the land portion 23 between the grooves.
C, and the length of the groove in the axial direction of the plunger 8 is approximately half the thickness of the cylinder reduction sleeve 23, and the cylinder reduction sleeve 23 is formed between the openings 23A of the relief grooves A to E and the closing part 23. Discern. Further, a predetermined number of teeth 23D are provided on the outer circumferential portion of the cylinder reducing sleeve 23 to form a gear.

Again in FIG. 3, the cylinder reduction sleeve 23
A driving device 24 is provided so as to selectively position the openings 23A or the closing portions 23B of the relief grooves I to E of the cylinder reduction sleeve 23 with respect to the relief port 22 by sliding the valve against the plunger 8. This drive device 24 converts the back and forth movement of the operating lever 25 into a linear motion to slide the cylinder reduction sleeve 23, and when the load is light, the cylinder reduction sleeve 23 is moved to the left and the relief port 22 is connected to its opening 23A.
The operating lever 25 is interlocked by a solenoid or the like operated via an engine load detection means so as to communicate with the engine load.

Apart from this sliding, the cylinder reduction sleeve 23
are rotated at different cycles relative to the plunger 8 which rotates in synchronization with the drive shaft 2, and during cylinder reduction operation, the relief port 22 of the plunger 8 is connected to the pump chamber 5A at a predetermined interval or rotation angle by its relief grooves I to H. A rotating device 26 is provided which communicates with the two. The rotating device 26 extracts the rotation of the drive shaft 2 at a predetermined reduction ratio via the first and second gears 19, 20, etc. that drive the governor mechanism 17, and
It is formed so as to transmit the rotation to the cylinder reduction sleeve 23 which is a gear.

In this case, the second gear 2 meshing with the first gear 19
0 is fixed to the governor shaft 21A, and a third gear 27 (pinion) that drives the cylinder reduction sleeve 23 is further fixed to the governor shaft 21A. In these reduction ratios, the number of teeth is set such that, for example, the cylinder reduction sleeve 23 rotates half a rotation for one rotation of the drive shaft 2 (plunger 8). The governor mechanism 17 is fixed to the tip of the governor shaft 21, and 28 is a bearing for the rotating governor shaft 21.

Next, the effect will be explained.

During all-cylinder operation, the drive device 24 closes the relief grooves A to E of the cylinder reduction sleeve 23 at the closing portions 23B.
covers the relief port 22 of the plunger 8 at all times, so the fuel introduced from the fuel intake port 6 into the high-pressure plunger pump 7 is caused by the rotational reciprocation of the plunger 8. The fuel is pressure-fed from the distribution port 13 through the delivery valve 14 to the injection nozzle, and is injected into all cylinders in sequence.

During cylinder reduction operation, the openings 23A of the relief grooves I to H of the cylinder reduction sleeve 23 are located above the relief port 22 of the plunger 8, and the rotating plunger 8
The relief port 22 is repeatedly communicated with and disconnected from the pump chamber 5A by the cylinder reducing sleeve 23 which rotates relative to the pump chamber 5A.

In this case, the relief groove of the cylinder reduction sleeve 23 is
As described above with reference to FIG. 8 rotates once in the direction of the arrow from the position shown in FIG. Repeat one more rotation,
The relief port 22 passes through the relief grooves D and E in this order and returns to its original position.

Therefore, the high-pressure fuel pressurized by the plunger 8 and supplied to each distribution port 13 in turn is
Radially arranged distribution ports 13 (injection order #1,
#2, #4, #5, #3) are sequentially released into the pump chamber 5A via the relief port 22, so no fuel is injected into the cylinder corresponding to the distribution port 13 and the cylinder is inactive. Pause.

In this way, injection is stopped 5 times (10 times when all cylinders are used) for every two revolutions of the plunger 8, and deceleration operation, that is, cylinder number control can be performed.For example, in an in-line 5-cylinder diesel engine,
When controlling the number of cylinders, the ignition order is #1-#2-
#4-#5-#3 is #1-#4-#3-#2-
#5-#1, and the ignition interval was 144°, #1-288°-#4-288°-#3-288
゜-#2-288゜-#5-288゜-#1,
The ignition intervals become equal and each cylinder is equally reduced.

Therefore, even in an engine with an odd number of cylinders, it is possible to control the number of cylinders without losing the balance of the engine, and since there is no need to limit the cylinders that are inactive, piston rings, liners, pistons, etc. wear is evened out,
Durability can also be improved.

Note that the relief grooves A to H of the cylinder reduction sleeve 23 covering the relief port 22 of the plunger 8,
If the rotation speed of the cylinder reduction sleeve 23 is appropriately selected,
It becomes possible to freely increase or decrease the number of reduced cylinders. Furthermore, it is clear that the present invention can be implemented in a similar manner for engines other than five-cylinder engines.

As explained above, in the present invention, a relief port is provided on the plunger of a distribution type fuel injection pump, and during partial cylinder operation, this relief port is communicated with the pump chamber at predetermined intervals in response to the operation of the plunger. Since the structure is configured so that the fuel supplied to each cylinder is opened or cut alternately and in order, it is easy to control the number of cylinders in a multi-cylinder diesel engine, and even in the case of an engine with an odd number of cylinders, it is possible to In the same way, evenly spaced ignition is possible, keeping the engine well balanced, and since each cylinder is reduced evenly, the number of cylinders can be controlled without uneven wear and tear on pistons, etc. It has excellent effects.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a normal distribution type fuel injection pump, Fig. 2 is a distribution diagram of the distribution port, Fig. 3 is a cross-sectional view showing an embodiment of the present invention, and Fig. 4 is a reduced-tube reduction cylinder according to the present invention. FIG. 3 is a front view of the sleeve. 6...Fuel suction port, 7...High pressure plunger pump, 8...Plunger, 8A...Guiding groove, 8B
...Center passage, 8C...Discharge port, 9...
Eccentric disk, 10...Face cam, 12...Roller, 13...Distribution port, 14
... Deliverable, 15 ... Spill Port, 16
... Spill ring, 17... Governor mechanism, 19...
...First gear, 20...Second gear, 21A...Governor shaft, 22...Relief port, 23...
Cylinder reduction sleeve, 23A...Opening part, 23B...Closing part, 23C...Land part, 23D...Teeth part, 2
4... Drive device, 25... Operation lever, 26...
Rotating device, 27...Third gear, 28...Bearing,
A, B, H, D, H... Relief groove.

Claims (1)

[Scope of utility model registration request] In a distribution type fuel injection pump in which fuel sucked by a feed pump is pressurized by a high-pressure plunger pump and then forcefully delivered to each cylinder, the plunger is provided with a relief port that releases high-pressure fuel to the pump chamber, and this relief port is A cylinder reduction sleeve with relief grooves arranged at equal intervals on the inner periphery is freely slidable on the plunger so as to selectively communicate with the pump chamber at predetermined rotation angle intervals, and the cylinder reduction sleeve is slid in the axial direction of the plunger. 1. A cylinder reduction device for a multi-cylinder diesel engine, comprising: a drive device that fully opens or fully closes a relief groove; and a rotation device that rotates a cylinder reduction sleeve relative to a plunger.