JPS6327066Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an internal combustion engine in which the pressure inside the combustion chamber is high, such as a diesel engine, in which the explosion pressure can be controlled.

Linear combustion diesel internal combustion engines, in which fuel is injected directly into the combustion chamber through an injection nozzle, have started to spontaneously ignite and explode at the same time as the fuel is injected due to the high temperature of the compressed air. There is. Therefore, at the time of an explosion, high pressure is created within the combustion chamber, and the cylinder and cylinder head that make up the combustion chamber must be made thick in order to withstand the high pressure. For this reason, internal combustion engines have become larger,
Increase in weight is unavoidable, which also causes an increase in costs.

This idea installed an explosion pressure control valve to keep the pressure in the combustion chamber below a certain value, and made the cylinder and cylinder head thinner.
The present invention aims to provide an internal combustion engine that can generate turbulence in late-stage combustion and improve combustion efficiency.

This invention will be explained below based on an embodiment shown in the drawings. Reference numeral 1 in FIGS. 1 and 2 is a cylinder, and a cylinder liner 2 is provided on the inner peripheral surface of the cylinder. A piston 3 is inserted into the cylinder liner 2 so as to be able to reciprocate, and a piston ring 4 fitted on the outer circumferential surface of the piston 3 slides on the inner circumferential surface of the cylinder liner 2.
A cylinder head 5 is provided at the top of the cylinder 1, and a combustion chamber 6 is formed between the inner surface of the cylinder head 5 and the head of the piston 3. Further, the cylinder head 5 is provided with an intake valve 7, an exhaust valve 8, an injection nozzle 9 for injecting fuel into the combustion chamber 6, and an explosion pressure control valve 10, which will be described later. To explain the explosion pressure control valve 10 in detail, 11 is a cylindrical housing provided integrally with the cylinder head 5, and a pressure accumulation chamber 13 communicating with the combustion chamber 6 via a communication portion 12 is formed inside the housing. ing. And this communication part 1
2 is provided with a first valve 14 and a second valve 15 that communicate or disconnect the combustion chamber 6 and the pressure accumulation chamber 13. That is, an outer valve seat 16 is provided at the opening edge of the pressure accumulating chamber 13, and a valve portion 17 of the second valve 15 is provided on the outer valve seat 16 so as to be able to move toward and away from the outer valve seat 16. This valve part 17
is formed by bulging out the tip of the valve pipe 18 in a trumped shape, and the bulging portion 19 is provided with a plurality of communication holes 20, 20 that communicate with the pressure accumulating chamber 13. Furthermore, the valve pipe 18 of this second valve 15
is a sliding hole 21 bored in the head of the housing 11.
The spring stopper ring 22 is fitted to the proximal end of the spring stopper ring 22 . A compression spring 23 is interposed between this spring stop ring 22 and the head of the housing 11, and the second valve 1
5 is always urged upward, that is, in a direction that presses the valve portion 17 against the outer valve seat 16. Further, an inner valve seat 24 is provided at the opening edge of the valve portion 17 of the second valve 15, and a valve portion 25 of the first valve 14 is provided on this inner valve seat 24 so as to be able to move toward and away from the inner valve seat 24. . The valve portion 25 is integrally provided at the tip of a valve shaft 26, and the valve shaft 26 is slidably inserted into the valve pipe 18 of the second valve 15. Furthermore, a compression spring 28 is interposed between the proximal end surface of the valve shaft 26 and a cap 27 attached to the proximal end of the valve pipe 18.
The valve 14 is always urged upward, that is, in a direction in which the valve portion 25 is brought into pressure contact with the inner valve seat 24. The spring force of the compression spring 28 is set so that the first valve 14 opens when the gas pressure in the combustion chamber 6 exceeds a certain value during an explosion.
The spring force of the compression spring 23 is set so that it is compressed and the second valve 15 opens when the inside of the combustion chamber 6 becomes lower than the pressure accumulation chamber 13 in the late stage of combustion.

As the piston 3 rises, the fuel injected from the injection nozzle 9 into the combustion chamber 6 spontaneously ignites due to the high temperature of the high pressure air, causing an explosion. When the gas pressure in the combustion chamber 6 exceeds a certain value due to this explosion, the valve portion 25 of the first valve 14 separates from the inner valve seat 24, and the first valve 14 opens. Therefore, a portion of the gas in the combustion chamber 6 escapes into the pressure accumulation chamber 13 via the communication holes 22, 22.
Therefore, the gas pressure in the combustion chamber 6 decreases, and the first valve 14 is closed by the restoring force of the compression spring 28. Furthermore, when the piston 3 descends and the inside of the combustion chamber 6 becomes lower than the pressure accumulation chamber 13, the second valve 15
The valve part 17 is separated from the outer valve seat 16 and the second valve 15 is opened. Therefore, the gas in the pressure accumulator 13 is ejected into the combustion chamber 6, and the ejected energy at this time causes turbulence in the latter half of combustion.

Here, when comparing the performance of the conventional internal combustion engine without an explosion pressure control valve and the internal combustion engine of this invention, as shown in Figures 3 and 4, this invention has an explosion pressure control valve that controls internal pressure. Even if P is suppressed to Pmax=P ₀ , thermal efficiency is improved by generating turbulence in the late stage of combustion. In FIGS. 3 and 4, the broken line curve is for the conventional internal combustion engine, the solid line curve is for the internal combustion engine of this invention, and the shaded area is the part cut by the first valve.

In the above embodiment, the explosion pressure control valve was configured by providing the first and second valves in duplicate, but this invention is not limited to the above embodiment; Two valves may be provided adjacently.

As explained above, this idea is to provide a pressure accumulating chamber in the cylinder head that communicates with the combustion chamber through a communication part, and to open the communication part to accumulate gas when the pressure inside the combustion chamber exceeds a certain value. Since an explosion pressure control valve is provided to release the combustion chamber, the pressure inside the combustion chamber can be kept below a certain value, and the cylinder and cylinder head can be made thinner. Furthermore, when the gas pressure in the combustion chamber becomes lower than the pressure in the pressure accumulation chamber, the gas in the pressure accumulation chamber is injected into the combustion chamber, which creates turbulence in the late stages of combustion and improves combustion efficiency. be.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is a longitudinal sectional front view of the cylinder head portion, FIG. 2 is a bottom view of the cylinder head, and FIGS. 3 and 4 are curve diagrams showing the performance of the conventional cylinder head and the present invention. DESCRIPTION OF SYMBOLS 1... Cylinder, 3... Piston, 5... Cylinder head, 6... Combustion chamber, 10... Explosion pressure control valve, 12... Communication portion, 13... Pressure accumulation chamber, 14... First valve, 15...Second valve.

Claims (1)

[Scope of utility model registration request] a cylinder, a piston that reciprocates within the cylinder, a cylinder head that is installed at the head of the cylinder and forms a combustion chamber between the head of the piston, and a cylinder head that is installed at the cylinder head and communicates with the combustion chamber. A first valve that is provided in a communication section between a pressure accumulation chamber and the combustion chamber of the pressure accumulation chamber and opens when the gas explosive force in the combustion chamber exceeds a certain value to release the gas in the combustion chamber to the pressure accumulation chamber; and a combustion chamber. An internal combustion engine characterized by comprising an explosion pressure control valve comprising a second valve that opens when the pressure in the chamber falls below a certain value and injects gas in the pressure accumulation chamber into the combustion chamber.