WO2007136180A1

WO2007136180A1 - Engine cylinder assembly

Info

Publication number: WO2007136180A1
Application number: PCT/KR2007/002253
Authority: WO
Inventors: Chang Dae Kim
Original assignee: Chang Dae Kim
Priority date: 2006-05-23
Filing date: 2007-05-08
Publication date: 2007-11-29
Also published as: KR200427698Y1

Abstract

An engine cylinder assembly is provided, which includes: a cylinder block; a cylinder liner; a piston; and an injection valve. In addition, an injection stroke is further included between an expansion stroke and an exhaust stroke. In the case that the piston reaches a bottom dead center of a cylinder according to the expansion stroke, an injection pressure of the obstacle exhaust injector assists the piston to further ascend, to thereby make the cylinder operate smoothly.

Description

ENGINE CYLINDER ASSEMBLY

Technical Field

The present invention relates to an engine cylinder assembly, and more particularly, to an engine cylinder assembly which can overcome an exhaust pressure obstacle when a piston ascend by an exhaust stroke after the piston has descended to a bottom dead center according to an expansion stroke.

Background Art

In general, an engine is configured as follows. A cylinder is manufactured as a part which forms a main body of the engine. The cylinder includes a cylinder block in which a water jacket through which cooling water flows, a cylinder head which is installed in the upper portion of the cylinder block to form a combustion chamber together with the piston, in which various valve mechanism, sparkplugs, etc., are installed, and a crankshaft which is combined with the cylinder head.

In the case of this cylinder, the piston reciprocates in the inside of the cylinder, through an air-absorption stroke, a compression stroke, an expansion stroke, and an exhaust stroke.

By the way, there is a problem that an exhaust pressure obstacle occurs to thus instantaneously cause an obstacle, by a high-pressure exhaust gas which remains in the inside of a conventional cylinder at a point in time when a piston which has reached a bottom dead center at an expansion stroke ascends again at an exhaust stroke, to thereby deteriorate a running efficiency of the engine.

Disclosure of the Invention

It is an object of the present invention to provide an engine cylinder assembly which further comprises an injection stroke so as to discharge an exhaust gas which remains in the inside of a cylinder after an expansion stroke and simultaneously inject part of the exhaust gas on a piston, to thus enable an engine to run smoothly.

To accomplish the above object of the present invention, there is provided an engine cylinder assembly comprising: a cylinder block in which a water jacket is incorporated, and on the inner wall surface of which a valve groove is formed at a position which is lower by a certain value than a bottom dead center; a cylinder liner which is installed in the inside of the cylinder block, in which an obstacle exhaust entrance and an obstacle exhaust injector communicating with the obstacle exhaust entrance are formed at a position corresponding to the valve groove, and an obstacle exhaust exit communicating with an exhaust pipe is formed in one side of the obstacle exhaust injector; a piston having an outer diameter smaller than an inner diameter of the cylinder liner so as to reciprocate in the inside of the cylinder liner, and on the outer circumferential surface of which a compression ring and an oil ring are combined so as to closely adhered to the inner wall of the cylinder liner; and an injection valve which is installed in the valve groove, in order to open and close the obstacle exhaust entrance and the obstacle exhaust injector.

Brief Description of the Drawings. FIG. 1 is a cross-sectional view showing a cylinder assembly which is viewed from the front side, according to a first exemplary embodiment of the present invention;

FIG. 2 is an enlarged view showing a portion "II" of FIG. 1 in detail; FIG. 3 is a cross-sectional view cut along line "IH-III" of FIG. 2;

FIG. 4 is a cross-sectional view showing a cylinder assembly which is viewed from the front side, according to a second exemplary embodiment of the present invention; FIG. 5 is an enlarged view showing a portion "V" of FIG. 4 in detail;

FIG. 6 is a cross-sectional view showing a cylinder assembly which is viewed from the front side, according to a third exemplary embodiment of the present invention; FIG. 7 is an enlarged view showing a portion "VII" of FIG. 6 in detail; and

FIG. 8 is a perspective view showing a modification of a cylinder liner according to the present invention.

Best Mode for Carrying out the Invention

Hereinbelow, an engine cylinder assembly according to preferred embodiments of the present invention will be described with reference to the accompanying drawings, respectively. Like reference numerals are assigned for like elements in the drawings.

As illustrated in FIG. 1, a cylinder assembly according to an exemplary embodiment of the present invention includes a cylindrical cylinder block 10, a cylinder liner 20 which is attached on the inside of the cylinder block 10, a cylinder head 30 which is combined with the upper side of the cylinder block 10, and a piston 40 which reciprocates in the inside of the cylinder liner 20.

A water jacket 11 which cools the cylinder whose temperature rises up during reciprocation of the piston 40 is provided in the inner wall of the cylinder block 10. An air inhalation passageway 31 and an air exhaust passageway 32 are formed in the cylinder head 30, and an air inlet valve 31a and an air outlet valve 32a are installed in the air inhalation passageway 31 and the air exhaust passageway 32, respectively.

On the inner circumferential surface of the cylinder liner 20 are provided an obstacle exhaust entrance 21 to make exhaust gas flow toward the cylinder liner 20, an obstacle exhaust injector 22 to make the exhaust gas discharged toward the piston 40, and an obstacle exhaust outlet 23 which makes the exhaust gas discharged toward the outside of the cylinder at certain intervals at a position corresponding to a bottom dead center L of the piston 40.

That is, as illustrated in FIGS. 2 and 3, the obstacle exhaust entrance 21 is formed at a position lower than the bottom dead center L of the piston 40. The obstacle exhaust injector 22 communicates with the lower side of the obstacle exhaust entrance 21 through an injection path 24. The obstacle exhaust outlet 23 is formed in one side of the obstacle exhaust injector 22 at the same height as that of the obstacle exhaust injector 22 (the height can be adjusted as being the case) and communicates with the exhaust pipe 25 which discharges the exhaust gas to the outside of the cylinder.

Here, the obstacle exhaust injector 22 is formed inwards and upwards slantingly to assist the exhaust gas flown into the obstacle exhaust entrance 21 to make the piston 40 move upwards. It is preferable that the obstacle exhaust injector 22 is slantingly formed at an angle of 45^° or more to further promote an ascending operation of the piston 40.

A valve groove 12 is formed with a certain depth to the outer direction in the inner side surface of the cylinder block 10 in correspondence to the position where the obstacle exhaust entrance 21 and the obstacle exhaust injector 22 are formed. An injection valve 50 is installed in the valve groove 12 in which the injection valve 50 controls the exhaust gas to be discharged through the obstacle exhaust injector 22 toward the piston 40 instantaneously. The injection valve 50 includes an opening and closing member 51 which is installed in the valve groove 12 to open and close the obstacle exhaust entrance 21 and the obstacle exhaust injector 22, and a plate spring 52 which is disposed in the outer side of the opening and closing member 51 and giving an elastic force to the opening and closing member 51. Here, the opening and closing member 51 may be installed to open and close only the obstacle exhaust injector 22.

In the case that the piston 40 is located at the bottom dead center L of the cylinder, the piston 40 has an outer diameter smaller than an inner diameter of the cylinder liner 20 so that exhaust gas remaining in the cylinder flows into the obstacle exhaust entrance 21. At least one ring groove (not shown) is formed with a certain depth on the outer circumferential surface of the piston 40. A compression ring 41 and an oil ring 42 are combined with the ring groove so as to closely adhered to the inner wall of the cylinder liner 20.

An injection guidance groove 43 is formed in the piston 40 at a position corresponding to the obstacle exhaust injector 22 in the case that the piston 40 reaches the bottom dead center L. It is preferable that the injection guidance groove 43 is slantingly- formed at the same angle as that of the obstacle exhaust injector 22.

FIGS. 4 and 5 illustrate an engine cylinder assembly according to a second exemplary embodiment of the present invention, respectively. Since the structure of cylinder assembly according to the second exemplary embodiment is substantially the same as that of the first exemplary embodiment, the detailed description thereof will be omitted. Only the composition of the injection valve 50 differs between the first and second exemplary embodiments.

That is, the injection valve 50 includes an opening and closing member 51 which is installed in the valve groove 12 to open and close the obstacle exhaust entrance 21 and the obstacle exhaust injector 22, a plunger 53 which is combined with the outer side of the opening and closing member 51 to move horizontally to thus transfer a driving force to the opening and closing member 51, and a coil spring 52' which is wound around the outer side of the plunger 53 to thus provide the plunger with an elastic force. Here, it is preferable that a housing groove (not shown) of a certain length is extensively formed in the cylinder block 10 to the outer side of the valve groove 12 to the cylinder blocklO, and a housing 54 is installed so that the plunger 53 and the coil spring 52' are incorporated in the housing groove. Meanwhile, a water jacket 11 is provided in the cylinder blocklO, to control a temperature rise by operation of the piston

40. In addition to the water jacket 11, a number of radiation fins

26 are installed on the outer circumferential surface of the cylinder liner 20 as illustrated in FIG. 8 in a vertical direction with a certain gap, to thereby further raise a cooling efficiency.

FIGS. 6 and 7 illustrate an engine cylinder assembly according to a third exemplary embodiment of the present invention, respectively. An injection valve 50 is vertically installed in an injection path 24 which connects the obstacle exhaust entrance 21 and the obstacle exhaust injector 22 in the third exemplary embodiment .

That is, the third exemplary embodiment is equal to the second exemplary embodiment in that composition of the injection valve 50 includes the opening and closing member 51, the plunger 53 and the coil spring 52', but the injection valve 50 in the third exemplary embodiment is installed to ascend and descend vertically in the injection path 24 which connects the obstacle exhaust entrance 21 and the obstacle exhaust injector 22 vertically. Here, the length of the injection path 24 is extended in comparison with those of the first and second embodiments to make the injection valve 50 fully reciprocate in the vertical direction.

A slope 51a which proceeds downwards from the outer side to the inner side in the upper end portion of the opening and closing member 51, so that the exhaust gas pressure can be sufficiently is delivered when the exhaust gas flows into from the obstacle exhaust entrance 21.

An operating process of the engine cylinder assembly having the above-described structure will follow.

First, the piston 40 descends while undergoing an expansion stroke through an air inhalation stroke and a compression stroke, at a state where the piston 40 is located in a top dead center H of the cylinder liner 20. If the piston 40 is located at the bottom dead center L of the cylinder liner 20, gas flows into the obstacle exhaust entrance 21 through a certain gap between the piston 40 and the inner wall of the cylinder liner 20, to thus overcome an elastic force of a plate spring 52 (or a coil spring) to then push out and open the opening and closing member 51 which blocks the obstacle exhaust entrance 21 and the obstacle exhaust injector 22.

Thereafter, the opening and closing member 51 which has been pushed out is restored again and guides the piston 40 to ascend upwards by an injection stroke which discharges exhaust gas instantaneously toward an injection guide groove 43 of the piston

40 through the obstacle exhaust injector 22.

Therefore, the piston 40 rises up by the injection pressure of the exhaust gas which is discharged from the obstacle exhaust injector 22, not to cause an exhaust pressure obstacle to occur but make an exhaust stroke occur smoothly.

As described above, the present invention further include an injection stroke between the expansion stroke and the exhaust stroke. In the case that the piston reaches a bottom dead center of a cylinder according to the expansion stroke, an injection pressure of the obstacle exhaust injector assists the piston to further ascend to thereby make the cylinder operate smoothly.

As described above, the present invention has been described with respect to particularly preferred embodiments. However, the present invention is not limited to the above embodiments, and it is possible for one who has an ordinary skill in the art to make various modifications and variations, without departing off the spirit of the present invention. Thus, the protective scope of the present invention is not defined within the detailed description thereof but is defined by the claims to be described later and the technical spirit of the present invention.

Industrial Applicability

As described above, the present invention provides an engine cylinder assembly which can overcome an exhaust pressure obstacle when a piston ascend by an exhaust stroke after the piston has descended to a bottom dead center according to an expansion stroke.

Claims

What is claimed is:

1. An engine cylinder assembly comprising: a cylinder block in which a water jacket is incorporated,, and on the inner wall surface of which a valve groove is formed at a position which is lower by a certain value than a bottom dead center; a cylinder liner which is installed in the inside of the cylinder block, in which an obstacle exhaust entrance and an obstacle exhaust injector communicating with the obstacle exhaust entrance are formed at a position corresponding to the valve groove, and an obstacle exhaust exit communicating with an exhaust pipe is formed in one side of the obstacle exhaust injector; a piston having an outer diameter smaller than an inner diameter of the cylinder liner so as to reciprocate in the inside of the cylinder liner, and on the outer circumferential surface of which a compression ring and an oil ring are combined so as to closely adhered to the inner wall of the cylinder liner; and an injection valve which is installed in the valve groove, in order to open and close the obstacle exhaust entrance and the obstacle exhaust injector.

2. The engine cylinder assembly according to claim 1, wherein an injection guidance groove is formed on the outer circumferential surface of the engine cylinder assembly in correspondence to the obstacle exhaust injector when the piston reaches a bottom dead center .

3. The engine cylinder assembly according to claim 1 or 2, wherein the obstacle exhaust injector and the injection guidance groove are slantingly formed upwards .

4. The engine cylinder assembly according to claim 1, wherein the injection valve comprises an opening and closing member which opens and closes the obstacle exhaust entrance and the obstacle exhaust injector and a plate spring which is arranged at the outer side of the opening and closing member.

5. The engine cylinder assembly according to claim 1, wherein the injection valve comprises an opening and closing member which opens and closes the obstacle exhaust entrance and the obstacle exhaust injector, a plunger which is combined with the opening and closing member to move horizontally, and a coil spring which is wound around the outer side of the plunger.

6. The engine cylinder assembly according to claim 1, wherein a number of radiation fins are protrudingly formed in a vertical direction in the outer circumferential surface of the cylinder liner.

7. An engine cylinder assembly comprising: a cylinder block in which a water jacket is incorporated, and an exhaust pipe is vertically formed; a cylinder liner which is installed in the inside of the cylinder block, in which an obstacle exhaust entrance and an obstacle exhaust injector communicate with each other by an injection path at a position lower than by a certain value than a bottom dead center, and an obstacle exhaust exit communicating with the exhaust pipe is formed in one side of the obstacle exhaust injector; a piston having an outer diameter smaller than an inner diameter of the cylinder liner so as to reciprocate in the inside of the cylinder liner, and on the outer circumferential surface of which a compression ring and an oil ring are combined so as to closely adhered to the inner wall of the cylinder liner; and an injection valve which is vertically installed in the injection path in order to open and close the obstacle exhaust entrance and the obstacle exhaust injector.

8. The engine cylinder assembly according to claim 7 , wherein the injection valve comprises an opening and closing member which opens and closes the obstacle exhaust entrance and the obstacle exhaust injector, a plunger which is combined with the opening and closing member to move vertically in the injection path and a coil spring which is provided in the lower side of the plunger.

9. The engine cylinder assembly according to claim 7, wherein a slope is formed downwards from the inner side to the outer side in the upper end portion of the opening and closing member.