JPS62189311A - Internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the efficiency of combustion and reduce block smoke and nitrogen oxide by providing an air supply means for supplying air to a precombustion chamber, a fuel supply means for supplying fuel to said chamber and a valve means for affording communication between a main combustion chamber and the precombustion chamber. CONSTITUTION:An internal combustion engine 1 has a precombustion chamber 4 provided additionally above a main combustion chamber 2 and communicating to the main combustion chamber 2 through a valve means 3. Further, an air supply means 5 for supplying air into the precombustion chamber 4 and a compressed air supply means 6 for supplying compressed air into the precombustion chamber 4 are provided while a fuel supply means 7 for injecting and supplying fuel into the precombustion chamber 4 is provided. Fuel can be premixed and activated under high pressure and temperature in the precombustion chamber 4. Thus, the efficiency of combustion can be improved and black smoke and nitrogen oxide can be reduced.

Description

[Detailed description of the invention] a. Industrial application field The present invention relates to an internal combustion engine with a pre-combustion chamber.

b. Prior art and its problems Combustion systems for internal combustion engines, for example compression ignition engines, include direct injection, pre-combustion chamber, swirl chamber, and air chamber.

However, in both combustion methods, liquid fuel is injected directly into the combustion chamber, so before a uniform gas mixture of the injected liquid fuel and air is formed,
Compression ignition combustion may have started. In this case, unburned hydrocarbons are generated within the combustion chamber and black smoke is emitted from the compression ignition engine, thus reducing fuel efficiency and contributing to air pollution.

In addition, many of the current compression ignition engines burn at high compression ratios and high temperatures, so they emit nitrogen oxides (Nox).
) were emitted in large quantities, which also contributed to air pollution.

The present invention was invented in view of the above-mentioned circumstances, and its purpose is to achieve high combustion efficiency and to greatly reduce black smoke, nitrogen oxides, etc. contained in exhaust gas. The purpose is to provide internal combustion engines.

Means for Solving Problem C1 In order to achieve the above object, the present invention provides an internal combustion engine having a pre-combustion chamber, an air supply means for supplying air to the pre-combustion chamber, and an air supply means for supplying air into the pre-combustion chamber. a fuel supply means for supplying fuel; interposed between the main combustion chamber and the pre-combustion chamber;
An internal combustion engine is provided with a valve means that is opened at a predetermined ignition timing to communicate the main combustion chamber and the pre-combustion chamber.

d. Examples Hereinafter, examples of the internal combustion engine according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an internal combustion engine 1 which is an embodiment of the present invention.
5 to 5 are diagrams showing various operating states of the internal combustion engine l,
Figure 6 shows inner P, 1! 1 is a diagram showing the operation of function 1;

The internal combustion engine 1 of this embodiment includes a pre-combustion chamber 4 attached above a main combustion chamber 2 and communicating with the main combustion chamber through a valve means 3.
and further includes an air supply means 5 for supplying air (atmosphere) into the precombustion chamber, and a compressed air supply means 6 for supplying compressed air into the precombustion chamber, and a means for supplying fuel into the precombustion chamber. It is equipped with fuel supply means 7 for supplying fuel by injection.

Furthermore, the internal combustion engine 1 has a premixture (
(described later)).

Next, the configurations of the valve means 3, air supply means 5, compressed air supply means 6, and compression means 8 will be described in detail.

The valve means 3 has a valve body 3a connected to the cam 3 via a rod 3b.
It is configured to be moved up and down by c.

The valve body 3a is always urged upward by a spring 3e disposed between the upper end 3d of the loft 3b and the compression means 8, and thereby the valve seat 3f formed above the main combustion chamber 2 of the cylinder 9 It is a normally closed valve.

The cam 3c is fixed to a camshaft 10, and is rotated by the rotational power of a crank shirt 11 (see FIGS. 2 to 5) being transmitted via a power transmission means (not shown) and the camshaft.

The rotational speed ratio between the camshaft 10 and the crankshaft 11 is determined according to a predetermined ignition timing,
In the case of this embodiment, since the internal combustion engine is a 4-cycle engine, 2=1.

Note that such a rotation speed ratio is preferably 1:1 in the case of a two-stroke engine, but is not particularly limited in any case.

Here, the main combustion chamber 2 is surrounded by a cylinder 9, a piston 12, and a valve body 3a, and the pre-combustion chamber 4 is formed by an auxiliary cylinder 9a extending above the cylinder 9 and a piston 8a.
and the valve body 3a.

Further, an annular portion 9b is protruded from the inner circumferential wall of the auxiliary cylinder 9a, and is located slightly above the upper surface of the piston 8a at the top dead center.
A subchamber 4a is formed by the auxiliary cylinder 9a and the auxiliary cylinder 9a.

Further, a passage 4b is formed in the wall forming the pre-combustion chamber 4 of the auxiliary cylinder 9a, and this passage 4b is connected to the sub-chamber 4a through holes 4c and 4d formed in the upper and central portions of the passage 4b.
and the pre-combustion chamber 4, respectively.

The holes 4c and 4d are controlled to open and close as the piston 8a moves up and down. The opening/closing timing of these holes 4c and 4d will be explained later.

The air supply means 5 includes a suction pipe 5a that guides clean air obtained through an air cleaner or the like (not shown) to the passage 4b, and a check valve 5b interposed between the suction pipe 5a and the passage 4b.

In the check valve 5b, the valve body 5C is pressed against the valve seat 5 by the spring 5d.
The e side is always biased, thereby forming a normally open valve.

This check valve 5b allows the suction pipe 5a from the passage 4b side to
Air backflow is prevented.

The compressed air supply means 6 is a pump 6a that compresses a part of clean air obtained through an air cleaner or the like as described above.
, a tank 6b that stores air compressed by the pump, and a conduit 6 that leads the compressed air from the tank to the passage 4b.
c, a check valve 6d having the same structure as the check valve 5b and interposed between the conduit 6c and the passage 4b, a normally closed solenoid valve 6e interposed in the middle of the conduit 6c, and the solenoid valve. It is composed of a solenoid valve control section 6f that controls the opening and closing of the valve 6e as appropriate.

The pump 6a is driven by the power of the crankshaft 11 of the internal combustion engine transmitted through a power transmission means (not shown).

The electromagnetic valve control unit 6f opens the electromagnetic valve 6e when the internal combustion engine is being accelerated (hereinafter referred to as acceleration) or under load (hereinafter referred to as loading), and compresses the air to the passage 4b side. It is operated to send air.

In this embodiment, the control rank 6g of the fuel supply pump 7a is largely moved in one direction when the internal combustion engine is accelerated or loaded, and the actuator of the switch 6h is pressed by the operation of the control rack 6g. The switch is opened, thereby allowing operating current to flow from the battery 61 to the solenoid valve 6e via the switch 6h.

In addition, 6J is a check valve interposed in the middle of the conduit 6 connecting the pump 6a and the tank 6b to prevent the compressed air from flowing back from the tank 6b to the pump 6a side, and 61 is a check valve in the tank 6b. This is a relief valve to keep the pressure constant.

The fuel supply means 7 is configured to inject and supply fuel pressurized by the fuel supply means pump 7a into the pre-combustion chamber 4 from an injection nozzle 7b.

Note that 7c is a glow plug for promoting vaporization of the fuel injected from the injection nozzle 7b.

The compression means 8 includes a piston 8a and an upper portion 8 of the piston 8a.
A cam receiver extending upward from b is a member 8c, the cam receiver is a spring 8d interposed between the member and the annular portion 9b of the auxiliary cylinder 9a, the cam receiver is disposed on the member, and It consists of a pair of cams 88 fixed to the camshaft 10.

The piston 8a is always urged upward by a spring 8d, and is moved up and down as the cam 8e rotates.

Note that the shape of the cam 8e is appropriately determined along with the shape of the cam 3G so as to satisfy the operation timing described later.

Further, the upper part 8b of the piston 8a has a hole 9c in the annular part 9b.
The hole is slidably inserted into the hole while maintaining a seal between the hole and the hole.

Furthermore, in the hole 8t drilled in the center of the piston 8a,
The rods 3b of the valve means 3 are slidably inserted through each other while maintaining a sealing property.

In addition, in FIG. 1, 8g is the relief recess of the glow plug 7c formed at the lower part of the piston 8a, 1) is the cylinder liner, 14 is the bearing that rotatably supports the cam shirt NO on the upper part of the auxiliary cylinder 9a, and in FIG. , 16
1 is an intake pipe that introduces air into the main combustion chamber 2; 16a is an intake valve thereof; 17 is an exhaust pipe that exhausts air from the main combustion chamber 2;
7a is its exhaust valve.

Next, with reference to FIGS. 2 to 6, the operation of this embodiment will be explained separately for normal operation and acceleration operation (or operation under load).

First, in the case of normal operation, during the intake stroke, the intake valve 16a is opened and the screw I/N 2 is moved downward. Accordingly, clean air is drawn into the main combustion chamber 2 through the intake pipe 16. At this time, the valve means 3 and check valves 5b and 6d are each closed, and the piston 8a is also in an immovable state. This state is shown in FIG. 2 (at the entry point in FIG. 6). When this state is maintained for a while and the compression stroke begins, the intake valve 1 immediately
6a is closed, and as the piston 1) moves upward, the air in the main combustion chamber 2 begins to be compressed, and on the other hand, the injection supply of fuel to the pre-combustion chamber 4 begins. Next, crank angle 27
The piston 8a is now moved downward by the cam 3c from around 0°C (point B in FIG. 6), and this point B is preferably about 270° in terms of crank angle. Following this downward movement of the piston 8a, the hole 4c is immediately opened, and the hole 4d is soon closed. As a result, compression of the premixture formed in the precombustion chamber 4 begins, and at the same time, the piston 8
The check valve 5b is opened by the negative pressure generated in the auxiliary chamber 4a by the downward movement of the auxiliary chamber 4a, and air is sucked and supplied into the auxiliary chamber 4a via the air supply means 5 (in FIG. point), and the situation at this time is shown in FIG.

In this state, when the check valve 5b is opened, air suddenly flows into the auxiliary chamber 4a, so the downward movement of the piston 8a is promoted, and the cam 8e and the cam receiver are mechanically connected to the member 8c. losses are reduced.

The activation of the premixture in the precombustion chamber 4 progresses, and the piston 12
When the fuel mixture approaches the top dead center, the premixture in the precombustion chamber 4 starts to precombust due to high temperature and pressure, and then the valve means 3 is opened (point D in FIG. 6). ,
Along with this, the pre-combustion gas in the pre-combustion chamber 4 is transferred to the main combustion chamber 2.
The fuel is suddenly injected into the main combustion chamber 2, and combustion begins within the main combustion chamber 2.

The state at this time is shown in FIG. Note that it is preferable that the fuel supply from the injection nozzle 7b is terminated before entering the expansion stroke, but the invention is not limited to this, and,
Before entering the expansion stroke, the piston 8a reaches the bottom dead center, and the check valve 5b is closed at the same time.

Next, when entering the expansion stroke, the valve means 3 is first closed (point E in FIG. 6), and then the piston 8a starts to move upward.

At this time, both check valves 5b and 6d are in a closed state.

This upward movement of the piston 8a causes the auxiliary chamber 9c and the passage
Compression of the air present in 54b begins. The state at this time is shown in FIG.

Further, when the piston 12 approaches the bottom dead center, the exhaust valve 17a is opened and the main combustion chamber 2 is opened during the exhaust stroke.
The combustion gas inside is exhausted to the outside via the exhaust pipe 17.

Subsequently, when the piston 12 approaches the top dead center, the intake valve 16a is opened, and after the piston 12 has passed around the top dead center, the exhaust valve 17a is closed, and the exhaust stroke ends, and the above-mentioned intake stroke starts again. , and thereafter the same operations as described above are repeated.

Next, the operation when the internal combustion engine 1 is in an operating state during acceleration or load application will be described.

Now, while the internal combustion engine 1 is performing normal operation as described above, it is suddenly accelerated (or a load is applied).
As described above, this sudden acceleration state (or Kaga load state) is detected by the electromagnetic valve control section 6f, whereby the switch 6h is closed and the 1iff valve 6e is operated and opened. Accordingly, the compressed air in the tank 6b is forcibly supplied to the passage 4b via the electromagnetic valve 6e + conduit 6c and the check valve 6d, and the air shortage in the pre-combustion chamber 4 is eliminated. This compressed air supply means 6 does not operate at a fixed timing, but is operated whenever acceleration or load is applied. Therefore, the compressed air supply means 6 is operable at both times.

In the above embodiment, the downward movement start timing (point B) and the upward movement start timing (point F) of the piston 8a are the opening timing (point D) and the closing timing (point E) of the valve means 3.
This is determined in close relation to the above, and is not particularly limited, but if limited, the valve means 3 is opened at least after the piston 8a starts to move downward, and the upward movement of the piston 8a is started after the valve means 3 is opened. According to this, the pre-mixture in the pre-combustion chamber 4 can be effectively compressed by the piston 8a, and the combustion gas in the pre-combustion chamber 4 can be effectively and almost completely exhausted. can be done.

Further, the timing to start the downward movement of the piston 8a and the timing to open the valve means 3 are at a crank angle of 270 degrees within the compression stroke.

Although it is preferable that the upward movement timing of the piston 8a and the closing timing of the valve means 3 be set after that time, the timing of the upward movement of the piston 8a and the closing timing of the valve means 3 are not necessarily limited to within the expansion stroke, but before the next downward movement start timing of the piston 8a comes from the expansion stroke. It is preferable that the time is set within a range sufficient for the piston 8a to return to the top dead center.

In this embodiment, the timing at which the piston 8a starts to move downward (point B)
The crank angle is around 270 degrees, the timing when the valve means 3 is opened (point D) is around the crank angle 330 degrees, and the timing when the piston 8a reaches the bottom dead center is immediately after the time when the valve means 3 is opened. It is preferable that the downward movement start timing of the piston 8a and the opening timing of the valve means 3 are advanced in accordance with the rotational speed.

Furthermore, it is preferable that the timing of fuel supply by the fuel supply means 7 is within the compression stroke (particularly within the range from the start of downward movement of the piston 8a to the crank angle of 360 @), but is of course not limited to this. It is sufficient that the fuel supply timing is within the range from after the closing of the piston 3 to the first half of the next expansion stroke. The length is preferably about 70'', but is of course not limited to this.

Further, in the above embodiment, the piston 8a and the valve means 3 are formed coaxially, but the present invention is not limited to this. The piston 8a and the valve means 3 may be configured to be actuated by the respective cams, and in short, the pre-combustion chamber 4 and the main combustion chamber 2 may communicate with each other via the valve means 3. However, it may be configured in any way.

Further, in the above embodiment, the piston 8a and the valve body 3a are formed separately and are configured to operate independently, but the present invention is not limited to this. It may be formed integrally and configured to be operated by one cam. In this case, since the valve means 3 is opened with the downward movement of the piston 8a, the premixture in the precombustion chamber 4 is It is not compressed, and its activation is particularly promoted.

Furthermore, in the above embodiment, the acceleration or loading of the internal combustion engine is detected from the amount of movement of the control rank 6g of the fuel supply pump 7a, but this is not limited to the present invention. It may be detected from the amount of rotation of the throttle valve or choke valve in the carburetor brake, or the amount of movement of the pump lever of the accelerator pump in the carburetor brake.In short, when the internal combustion engine is accelerating (
Any method may be used as long as it can detect the presence of the load (or when a load is applied).

Furthermore, it is of course possible to interpose various types of superchargers in the suction pipe 5a of the air supply means 5.

In addition, the internal combustion engine according to the present invention may be of either a two-stroke or four-stroke type, and may be a normal gasoline engine (Otto cycle) or a diesel engine, and is not particularly limited.

e. As described in detail, the internal combustion engine according to the present invention is capable of premixing and activating fuel under high pressure and high temperature in the precombustion chamber. In particular, combustion efficiency can be increased even when the compression ratio is lower than that of a compression ignition engine. For this reason, black smoke, nitrogen oxides (
NOx) can be reduced, and therefore air pollution caused by black smoke and nitrogen oxide emissions can be prevented. Furthermore, it is possible to prevent the occurrence of diesel knock, etc., and to improve acceleration performance while preventing the emission of a large amount of black smoke during acceleration or load application.

Furthermore, in the present invention, by additionally installing a compression means in the pre-combustion chamber, it is possible to further improve the activation of the fuel in the pre-combustion chamber, and also to effectively pre-combust the fuel. This allows the combustion efficiency to be further increased (improved).

[Brief explanation of drawings]

Conceptual diagram showing various operating states to explain the 6th
The figure is a diagram showing the operation of the embodiment shown in FIG. 1... Internal combustion engine, 2... Main combustion chamber, 3
... Valve means, 3a... Valve body, 3b...
・Rod, 3c...Cam, 3d...Upper end, 3e...Spring, 3f...Valve seat, 4...Pre-combustion chamber,
4a...Auxiliary room, 4b...Aisle, 4c
, 4d... hole, 5... air supply means, 5a... suction pipe, 5b... check valve,
5c...Valve body, 5d...Spring, 6...Compressed air supply means, 6a...Pump, 6
b... Tank, 6C... Conduit, 6d
...Check valve, 6e...Solenoid valve, 6f.
...1! Magnetic valve control unit, 7...Fuel supply means, 7
a... Fuel supply pump, 7b... Fuel injection nozzle, 7c... Glow plug, 8... Compression means, 8a... Piston, 8b... Piston upper part, 8C
...Cam holder is a member, 8d...Spring, 8
e...cam, 8f Kawakou, 8g...
Relief recess, 9... cylinder, 9a...
Auxiliary cylinder, 9b...annular part, 9c...hole, 1o...camshaft, 11...
・Crankshaft, 12...Piston, ]3...
・Cylinder litchi, I4...Bearing, 15・
... Sub-chamber, 16... Intake pipe, 16a
...Intake valve, 17...Exhaust pipe, 17a.
・Exhaust valve. 1st! Figure 2 Figure 4 Figure 30 ′::′25 end

Claims (3)

[Claims] (1) In an internal combustion engine equipped with a pre-combustion chamber, an air supply means for supplying air to the pre-combustion chamber, a fuel supply means for supplying fuel into the pre-combustion chamber, the main combustion chamber and the pre-combustion chamber. An internal combustion engine comprising: a valve means interposed between the main combustion chamber and the pre-combustion chamber that is opened at a predetermined ignition timing to communicate the main combustion chamber with the pre-combustion chamber. (2) The internal combustion engine according to claim (1), further comprising compression means for compressing the premixture formed in the precombustion chamber at a predetermined ignition timing. (3) Claims (1) and (2), characterized in that the invention further comprises a compressed air supply means for supplying compressed air to the pre-combustion chamber during acceleration and/or during load application. Internal combustion engine.