JPH0444105B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel injection device for use in a compression ignition engine.

[Conventional technology]

The fuel injection method for compression ignition engines is the air injection method, in which fuel is injected together with compressed air.
There are two types: the airless injection type, which injects only fuel under high compression.In recent years, the latter method has been adopted in most engines, except in special cases.

[Problem that the invention seeks to solve]

The above-mentioned airless injection type fuel injection means has come to be widely used because it has less power loss and no failure than the air injection type, but it also improves the atomization and combustion condition of the fuel injection. This necessitates high-pressure injection and requires complex and highly accurate injection pumps and injection nozzles, leading to high cast. In addition, the latent heat of vaporization required to atomize the fuel when injected into the cylinders is taken away, making it difficult to start the engine unless the compression ratio is increased, and the combustion state during warm-up is affected. It also has a negative impact.

The present invention aims to provide a fuel injection device with a simple structure and low cost, which has good fuel atomization performance, makes it easy to obtain a good combustion state, and is effective in easily performing a cold start.

[Means for solving problems]

The characteristic structure adopted by the present invention in order to achieve the above object is configured to suck air into the plunger chamber during the return stroke of the plunger driven in synchronization with engine rotation, and to A fuel inlet is connected to the passage so that the fuel is atomized and mixed into the intake air as air is drawn into the plunger chamber, and the compressed air-fuel mixture is injected by the advancing operation of the plunger. It is configured to blow out the compressed air in the cylinder through the hole.

[Effect]

If configured as described above, for example, FIGS. 3 and 1
As shown in the figure, when the plunger 32 retreats to the left in the drawing and air is rapidly drawn into the plunger chamber 33 through the passage 36, the fuel from the fuel inlet 28 flows out with this air flow. The liquid passes through the passage 40 and flows into the passage 36 while being atomized. As a result, air and atomized fuel are mixed in the passage 36, and this air-fuel mixture is sucked into the plunger chamber 33 from the passage 36.

Next, when the plunger 32 advances to the right in the drawing, the air-fuel mixture is compressed in the plunger chamber 33 to a high pressure, and the temperature of the air-fuel mixture is raised by the heat of compression at this time.

Then, the aforementioned high-pressure, high-temperature air-fuel mixture is directly injected into the compressed and high-temperature air inside the cylinder.

〔Effect of the invention〕

Since the combustion injection device according to the present invention is constructed and operates as described above, it brings about the following effects.

Air and fuel are mixed in advance to a certain extent in the passage before entering the plunger chamber, and then rapidly sent into the plunger chamber, so the fuel can be mixed even under particularly high pressure than when air and fuel are sent separately into the plunger chamber. This results in good atomization and sufficient mixing of air and fuel within the plunger chamber.

Since the air-fuel mixture in the plunger chamber is compressed to a high pressure and high temperature, the latent heat of vaporization due to fuel atomization can be compensated for in advance during injection, and a reliable and smooth start can be performed without particularly increasing the compression ratio.

Since the air-fuel mixture is compressed to high pressure and high temperature in the plunger chamber and injected into the engine combustion chamber, it is easier to achieve good combustion conditions and reduce diesel nok and smoke.

It does not require complicated and highly accurate equipment such as conventional injection pumps and injection nozzles, and can be implemented at low cost.

In the present invention, the amount of air sucked into the plunger chamber is determined by the volume of the plunger chamber when the plunger is moved back the most. If the amount of air to be taken in is determined in this way, the amount of fuel that flows into this air along with the flow of the air to be taken in is also approximately determined.

Therefore, it is only necessary to provide a general variable throttle valve and a governor device for fuel, and there is no particular need for a device that accurately controls the amount of fuel.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on illustrative drawings.

FIG. 1 shows an overall longitudinal side view of the engine, and FIG. 2 shows its longitudinal front view. The main body case 1 of this engine has a two-part structure in which a front case 1a, which is the output side, and a rear case 1b, which is the head side, are bolted together. 3 is rotatably supported horizontally.

The cylinder case 3 includes the bearings 2,
It consists of front and rear cylindrical shaft cases 4, 5 which are supported by 2, and an intermediate case 6 which is clamped and connected between them.
A through-type cylinder 7 having an axis perpendicular to the rotation axis P of the cylinder case 3 is attached to the intermediate case 6.
is formed.

A pair of pistons 8 , 8 are fitted inside the cylinder 7 so as to face each other, and a steel ball (solid or hollow) 9 is rotatably attached to the skirt portion of each piston 8 via a bearing metal 10 having a partially spherical shell shape. and is supported by a stopper ring 11 to prevent it from coming off.

A cam plate 12 is fastened together between the front and rear cases 1a, 1b of the main body case 1, and the steel balls of the pistons 8, 8 are inserted into an oblong cam hole 13 formed in the center of the cam plate 12. 9 and 9 are inscribed, and each piston 8 reciprocates twice for each rotation of the cylinder case 3.

The rear end surface of the cylinder 7 is configured to be in sliding contact with the head portion 14 formed at the center of the rear case 1b in the direction of the cylinder case axis, and a single suction shaft eccentric to the cylinder case rotation axis P is provided on the rear end surface of the cylinder. An exhaust port 15 is formed. Further, an exhaust hole 16, an intake hole 17, and a fuel injection hole 18 are provided on the sliding surface of the head portion 14 with a predetermined angular phase along the moving direction of the intake and exhaust port 15, and the cylinder case 3 As the cylinder case 3 rotates, the intake/exhaust port 15 is sequentially communicated with the exhaust/intake holes 16, 17 and the nozzle 18 at appropriate timings, and four cycles of exhaustion-intake-compression-explosion-expansion are performed, and the cylinder case 3
is continuously rotated in a fixed direction A.

The rotational output of the cylinder 3 is then fitted into the pulley 19 attached to the outer end of the front cylinder shaft case 4 or into the shaft end spline hole 20.
It is adapted to be taken out from a PTO shaft (not shown).

A fan 21 is attached to the shaft end of the front cylinder shaft case 4 together with the output pulley 19, and a fan 21 is attached to the shaft end of the front cylinder shaft case 4 so as to circulate the outside air taken in from an opening 22 formed at the center of the rear part of the rear cylinder shaft case 5 around the cylinder 7. After the cooling air passes through the cooling air passage 24 formed between the ribs 23, it is suctioned and discharged from the exhaust port 25 provided on the front end circumference of the front cylinder shaft case 4, and is discharged from the head 14 and the cylinder 7.
It is configured to provide cooling.

The exhaust hole 1 is provided on the outer side of the head portion 14.
A muffler 26 that communicates with the intake hole 6 and an air cleaner 27 that communicates with the intake hole 17 are connected to each other, and a fuel inlet 28 that is connected via piping to a fuel tank (not shown) is provided. is connected to a fuel injection device described below.

Details of the fuel injection system are shown in FIG.

That is, a plunger type pump casing 29 is embedded and fixed inside the head portion 14, and the injection nozzle 18 is formed at the tip thereof. Inside this pump casing 29, there is a Rocker arm 3.
A plunger 32, which is driven forward and backward by a spring 31 and biased to return to a backward position by a spring 31, is fitted inside the plunger 32. A group of small holes 34 are formed around the circumference of the plunger chamber 33 formed in the pump casing 29, and are opened when the plunger 32 is retracted.
This group of small holes 34 is connected to the intake hole 17 via an annular groove 35 and a passage 36.

A fuel control valve 37 whose opening degree is adjusted is provided in the intake system passage 36. The fuel control valve 37 includes a fixed sleeve 38 located on the rotational axis P of the cylinder case 3 and embedded in the head 14, and a tapered needle that moves back and forth along the axis P with respect to the fixed sleeve 38. 39, the fuel inlet 28 communicates with the inside of the sleeve 38 via a flow path 40, an annular groove 41, and a communication hole 42, and a gap between the sleeve 38 and the needle 39 is opened by moving the needle 39 back and forth. By adjusting the temperature, the amount of fuel flowing into the passage 36 of the intake system is adjusted.

The needle 39 is configured to be controlled to advance and retreat by a mechanical governor. This governor is
A governor spring 43 that presses the needle 39 in a direction that increases the opening of the control valve 37, and a governor weight 4 that generates a governor force that presses the needle 39 in a direction that decreases the opening of the control valve.
4, and is configured to be able to set the speed by adjusting the forward and backward movement of a spring receiving rod 45 that receives the rear end of the governor spring 43 using a speed regulating arm 46. The speed regulating arm 46 is linked to a speed regulating lever (not shown) via a release wire 47.

The governor weight 44 is attached to the cylinder case 3
It is housed in a recess 48 formed eccentrically with respect to the rotation axis P at the rear end, and is pivotably supported on a bracket 49 screwed and fixed to the cylinder case 3. An arm 44a connected from the governor weight 44 is brought into contact with the tip of a push rod 39a connected from the needle 39, so that the centrifugal force (governor force) of the governor weight 44 is transmitted to the needle 39. .

The rocker arm 30 for driving the plunger is supported by a ball fulcrum 51 formed integrally with the head cover 50, and one end of the arm 51 is connected to the bush rod 5.
2 to one end of the bell crank 53,
Furthermore, the other end of this bell crank 53 is provided with a ball 5 on the outer periphery of a cam 54 which is integrally formed with the rear cylinder shaft case 5.
5, and the plunger 32 is driven to reciprocate once for each rotation of the cylinder case 3. The tip of the rocker arm 30 on the plunger side is engaged in a recess 57 of an abutment piece 56 that is driven and fixed to the rear end of the plunger 32, thereby preventing the rocker arm 30 from swinging laterally.

The engine according to the present invention is constructed as described above, and its operation will be explained next.

The cylinder case 3 is rotated clockwise in FIG. 5, and the intake/exhaust port 15 overlaps the exhaust hole 16, and both pistons 8, 8 move toward each other to perform exhaustion, and then the intake/exhaust port 15 overlaps with the exhaust hole 16. The exhaust port 15 overlaps with the intake hole 17, and both pistons 8, 8 move away from each other due to centrifugal force, so that the cylinder 7
Air is taken into the engine and continues into the intake compression stroke.

Then, before this intake compression stroke is completed, the plunger 32 is driven backward and forward once, and the spring 31
Air is rapidly sucked into the plunger chamber 33 by the retreat of the plunger 32 via the control valve 3 due to the negative pressure generated in the passage 36 at this time.
Fuel is sucked in from 7 and mixed with the air while being atomized. The air-fuel mixture thus formed flows into the plunger chamber 33 through the group of small holes 34, and atomization of the fuel is further promoted at this time. Then, due to the forced advance of the plunger 32, the plunger chamber 33
A certain amount of the air-fuel mixture within is compressed and becomes a high-pressure, high-temperature air-fuel mixture.

After this air-fuel mixture compression is completed, the intake/exhaust port 15 of the cylinder case 3, which has completed the intake compression stroke, is connected to the nozzle 1.
8, the high-pressure, high-temperature air-fuel mixture in the plunger chamber 33 is ejected into the high-temperature compressed air in the cylinder 7, and the explosion and expansion stroke begins. During this explosion and expansion stroke, the plunger 32 is held at the final advance (compression) position, and the combustion gas is maintained in a state where it is prevented from flowing into the plunger chamber 33.

Then, following the explosion and expansion stroke, the exhaust stroke begins, and this cycle is repeated thereafter.

The intake/exhaust port 15 and the head portion 1 when the cylinder 7 is in the intake compression stroke and the explosion expansion stroke.
4, a thrust ring 59 with a seal ring 58 is fitted into the edge step of the intake/exhaust port 15, and the internal pressure of the cylinder 7 is transferred to the front gap 60 of the thrust ring 59. The thrust ring 59 is brought into close contact with the head portion 14 by acting on the thrust ring 59.

Further, on the end surface of the head portion 14, the air intake/exhaust port 1 is provided.
An annular groove 61 for collecting gas leaked from the groove 6 is formed, and a part of the groove 61 is communicated with the intake hole 17 via a passage 62.
The cylinder 7 is configured to return the gas recovered in the cylinder 1 to the cylinder 7 together with the intake air.

Incidentally, lubricating oil is stored in the main body case 1 to lubricate various sliding and rolling parts.

[Another example]

The fuel injection device according to the present invention can be used not only for the above-mentioned three-cylinder case rotating type engine, but also as a fuel injection device for a general compression ignition engine with intake and exhaust valves.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view of an engine according to the present invention;
Figure 2 is a longitudinal front view, Figure 3 is an enlarged sectional view of the fuel injection device, Figure 4 is a front view from the head side,
FIG. 5 is a front view of the head portion taken longitudinally. 7... Cylinder, 18... Injection hole, 28... Fuel inlet, 32... Plunger, 33... Plunger chamber, 36... Passage.

Claims (1)

[Claims] 1. The plunger 32 is driven in synchronization with the rotation of the engine and is configured to suck air into the plunger chamber 33 during the return stroke, and the fuel inlet 28 is connected in communication with the air intake passage 36 to the plunger chamber 33. As air is drawn into the plunger chamber 33, the fuel is atomized and mixed into the intake air. An engine fuel injection device configured to inject fuel into the compressed intake air in the engine.