KR100626932B1 - Piston for diesel engine - Google Patents

Abstract

The present invention provides a piston for a two-cycle diesel engine that can block oil from flowing into the combustion chamber while operating the engine, and at the same time, prevent explosion pressure or turbo pressure from flowing into the crank chamber. Of the six rings provided in the main body of the piston, a plurality of passages are formed on the upper surface of the first ring inserted into the first receiving groove of the main body to guide the movement of the explosion pressure during the explosive stroke, and the inclined portion is provided on the upper side of the first ring. Formed; An inclined portion is formed at each of the upper and lower sides of the third ring inserted into the third accommodating groove of the main body, and the outer periphery forms a flat surface for adsorption of oil; The fourth ring inserted into the fourth receiving groove of the main body has an inclined portion formed on the upper side, a scraping portion formed on the lower side to scrape oil off, and an outer periphery of the oil to prevent oil from flowing into the combustion chamber. Pocket grooves are formed to accommodate the; The fifth ring inserted into the fifth accommodating groove of the main body has a continuously formed first outer circumference which is inclined downward on the upper part of the outer circumference to prevent the oil from flowing into the combustion chamber and prevent the turbo pressure from flowing into the crank chamber. And a second outer periphery smaller than the first outer periphery and in which a plurality of oil through grooves are formed discontinuously.

2-cycle diesel engine, piston, oil ring, compression ring, scraping, cylinder liner

Description

Piston for two cycle diesel engine {PISTON FOR DIESEL ENGINE}

1 is a perspective view showing a piston for a conventional two-cycle diesel engine.

2 is a partially enlarged cross-sectional view sequentially showing rings inserted into the piston of FIG.

Figure 3 is a perspective view showing a piston for a two cycle diesel engine according to the present invention.

4A-4F are partially enlarged cross-sectional views sequentially showing the rings inserted into the piston of FIG. 3.

♣ Explanation of symbols for the main parts of the drawing ♣

10: main body 12-22: receiving groove

30: first ring 32: passage

40: second ring 50: third ring

56: flat surface 60: fourth ring

64: scraping part 66: pocket groove

70: fifth ring 80: sixth ring

The present invention relates to a piston for a two-cycle diesel engine, and more particularly, to reduce smoke and prevent fire during operation of the train, to extend the life of the engine, and to provide a stable and environmentally friendly operation of a locomotive. A piston for a two cycle diesel engine having a functional ring.

In general, various systems, machines, devices and the like are equipped with engines or engines for their own drive or for generating the required power. Such engines may be classified into gasoline engines, diesel engines, gas engines, electric engines, etc., depending on the fuel used, and may also be classified into two-cycle engines, four-cycle engines, and the like depending on the operation.

Basically, all such engines are essentially equipped with one or more cylinders and pistons reciprocating in each cylinder. That is, a typical engine has one or more cylinders, and a cylinder liner is provided inside the cylinder. In the center of the cylinder, an air inlet port is provided for supplying air into the cylinder from a turbocharger (not shown).

On the other hand, in the case of railway vehicles, due to the rail, that is, due to the particularity of traveling along the railway, the engine is different from the general vehicle, and in particular, the piston constituting the engine is provided with a plurality of functional rings. That is, as shown in Figs. 1 and 2, the two-cycle diesel engine piston has a cylindrical body (B) that can be operated up and down by a connecting rod in the cylinder liner (L) of the cylinder (C). Six accommodating grooves R are formed around the main body B, and piston rings, that is, first to sixth rings 1, 2, 3, 4, 5, and 6, are inserted into each receiving groove. Here, the first ring (1) to the fourth ring (4) is a compression ring, and serves to prevent the leakage of compressed air during the compression stroke and the explosion gas in the explosion stroke. Each of these piston rings, that is, compression rings 1 to 4, has a great influence on wear, engine efficiency and performance when gas pressure is transmitted to the compression rings to interact between the cylinder liner, piston, and piston ring. The first ring (1) of each of the compression ring is the top surface is flat, the upper side and the lower side is chamfered, the receiving groove (1a) of a predetermined interval is formed along the periphery, the upper surface and each receiving groove Are plated with chrome. The second ring 2 is formed similarly to the first ring, and each of the receiving grooves 2a is plated with chromium. The receiving ring 3a is formed in the third ring 3 and is formed in the same manner as the second ring 2. The fourth ring 4 has a configuration in which the upper side and the lower side have not been chamfered, and ferrous oxide 4a is inserted at a predetermined interval around the fourth ring 4.

The other piston ring, i.e. the fifth ring 5 and the sixth ring 6, inserted into the receiving groove of the piston below this compression ring is an oil ring, to scrape the lubricant from rising to the upper part of the cylinder, that is, the upper part of the combustion chamber. It prevents the inflow into the combustion chamber. Here, the fifth ring 5 is an oil ring that serves as a scraping role, and has two outer circumferential edges 5a at the outer circumference thereof and an oil through groove 5b is formed at the outer circumferential edge of the lower portion. An elastic ring 6a is inserted into the sixth ring 6, and a protruding piece 6b capable of scraping oil along its periphery is integrally formed at the center and the bottom of the outer side.

However, this conventional two-cycle diesel engine piston has been shown to cause a variety of problems. First, among the compression rings provided on the upper part of the piston, the first ring is in excessive contact with the cylinder liner, so that the pressure increases, wear is increased, and the flutter of the ring is caused. Outflow of pressure is caused, there is a problem that the oil flows into the combustion chamber by the fourth ring.

In addition, there is a problem in that oil flows into the combustion chamber and turbo pressure flows into the crank chamber by the fifth ring.

As a result, the above problems result in an increase in soot and nitrogen oxides (NOx), emissions of engine oil and atmospheric emissions of exhaust gas flames, increased fuel consumption and shortened engine life, There is a problem that results in unstable and unenvironmental operation.

On the other hand, it has been found that the problems as described above may inevitably be caused by the structure of the conventional cylinder or the cylinder liner and the oil ring having the oil scraping function. That is, the inlet port of the cylinder is expanded to take into account thermal expansion while the oil scraping oil ring has the same diameter of each of the hooks located at the top and the bottom, so that when the piston is at top dead center or downward motion After switching, the lower hook contacts the cylinder liner while the upper hook does not make contact with the cylinder liner. As a result, a gap or gap is formed between the cylinder liner and the oil ring having the scraping function, and the pressure is introduced into the cylinder and the piston through the gap, which is the main cause of the problems described above.

Therefore, the present invention has been invented to solve the above problems, an object of the present invention is to provide a piston for a two-cycle diesel engine that can save fuel, reduce soot and nitrogen oxides, and increase the thermal efficiency and engine efficiency. To provide.

Another object of the present invention is to provide a piston for a two-cycle diesel engine that can improve the atmospheric environment and become environmentally friendly.

These objects are provided with a cylinder liner therein and reciprocate in a cylinder in which the side communicates with an air source, four receiving grooves are formed from the upper side of the outer side, and two receiving grooves are formed in the lower portion of the first to sixth ends. In the piston for the two-cycle diesel engine, the first to sixth ring is accommodated in each receiving groove, the upper surface of the first ring is inserted into the first receiving groove of the body A plurality of passages are formed to guide the movement of the explosion pressure during the explosion stroke, and an inclined portion is formed on the upper side; An inclined portion is formed at each of the upper and lower sides of the third ring inserted into the third accommodating groove of the main body, and the outer periphery forms a flat surface for adsorption of oil; The fourth ring inserted into the fourth receiving groove of the main body has an inclined portion formed on the upper side, a scraping portion formed on the lower side to scrape oil off, and an outer periphery of the oil to prevent oil from flowing into the combustion chamber. Pocket grooves are formed to accommodate the; The fifth ring inserted into the fifth accommodating groove of the main body has a continuously formed first outer circumference which is inclined downward on the upper part of the outer circumference to prevent the oil from flowing into the combustion chamber and prevent the turbo pressure from flowing into the crank chamber. And smaller than the first outer circumference, and may be achieved by a piston for a two cycle diesel engine, characterized in that it is integrally provided with a second outer circumference in which a plurality of oil through grooves are formed discontinuously.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, referring to FIG. 3, a piston for a diesel engine, in particular a two cycle diesel engine, according to the present invention basically has a piston body 10 reciprocating in a cylinder, as described above. The piston body 10 is provided with a plurality of receiving grooves in the upper portion, the piston ring is inserted in each receiving groove.

In more detail, six receiving grooves 12; 14; 16; 18; 20; 22 are formed in the main body 10 of the piston, and the first receiving groove 12 of the uppermost of these receiving grooves is formed. The first ring 30, which is one of the compression rings, is inserted. A plurality of passages 32 are formed on the first ring 30. In the present embodiment, the number of passages 32 is preferably eight. Each of these passages 32 serves to guide or promote the movement of the explosion pressure during the explosion stroke. A relatively large inclined portion 34 is formed on the upper side of the first ring, and a relatively small inclined portion 36 is formed on the lower side. It is preferable that the inclination angle a of the inclination part 34 of the upper side is set to about 30 degrees. It is preferable that a plurality of grooves 38 are formed at predetermined intervals around the first ring 30. In addition, the first ring 30 is preferably plated with chromium.

The second ring 40 inserted into the second accommodating groove 14 is also a compression ring, and relatively small inclined portions 42 and 44 are formed at the upper and lower sides, respectively, and a plurality of grooves 46 are formed at the outer periphery. Is formed. The second ring 40 is preferably plated with chromium.

Relatively small inclined portions 52 and 54 are formed on the upper and lower sides of the third ring 50 inserted into the third accommodating groove 16, respectively. In addition, unlike the first ring 30 and the second ring 40 described above, the outer circumference forms a flat surface 56 in which no groove is formed, which is to enhance the adsorption of oil.

The fourth ring 60 inserted into the fourth accommodating groove 18 serves to prevent oil from flowing into the combustion chamber. The fourth ring 60 is an oil ring serving as a scraping role. The upper side of the fourth ring 60 is formed with a relatively large inclined portion 62. In addition, the lower side is formed with a scraping portion 64 that is almost perpendicular or acute. In particular, the outer periphery is formed pocket groove 66 that can accommodate the oil.

The fifth ring 70 inserted into the fifth accommodating groove 20 is an oil ring which serves to prevent oil from flowing into the combustion chamber and turbo pressure from flowing into the crank chamber. The second outer portion of the fifth ring 70 is smaller than the first outer circumference 72 and the first outer circumference continuously formed to be inclined downward and the second outer circumference is formed discontinuously. The peripheral edge 74 is integrally provided. In this embodiment, the difference in diameter between the first outer circumference 72 and the second outer circumference 74 is preferably about 0.2 mm to about 0.6 mm, most preferably about 0.5 mm. Accordingly, as shown in the drawing, the radial protrusion difference d between the first outer circumference 72 and the second outer circumference 74 is about 0.1 mm to about 0.3 mm, and preferably about 0.25 mm. .

The sixth ring 80 inserted into the sixth accommodating groove 22 serves as an oil ring similar to the fifth ring 70. The sixth ring 80 is generally formed with an accommodating groove 82 therein, and an elastic spring 84 for inserting elasticity is inserted into the accommodating groove. The rail 86 is integrally formed to protrude from the center and the lower side of the outer periphery. Each rail 86 is preferably plated with chromium.

Hereinafter, the operation mode of the piston for a two-cycle diesel engine according to the present invention will be described in detail.

For example, in a two-cycle diesel engine of a railway vehicle, the explosion pressure generated during the explosion stroke of the piston is rapidly moved and introduced through the passage 32 formed on the upper surface of the first ring 30 to be delivered to the ring, thereby compressing performance. In addition to improving the airtightness of the explosive gas, the pressure applied to the inside of the first ring 30 is reduced by the range in which the respective passages 32 are formed, thereby reducing the contact area of the cylinder liner L and the contact pressure thereof. This not only reduces the wear of the ring and liner, but also prevents ring oscillation or vibration, ie flutter of the ring. Of course, the second ring 40 is a compression ring to prevent leakage of fuel gas during compression and explosion stroke.

The third ring 50 is a compression ring formed of cast iron or DCI cast iron is to be strongly adsorbed during the compression and explosion stroke to prevent the pressure flow through the gap between the liner (L) and the outer peripheral surface of the ring (50). .

The fourth ring 60 is a ring that plays a role of scraping. The inclined portion 62 moves the oil to the periphery of the ring and distributes the oil evenly in the liner L as well as providing oil to the surrounding pocket groove 66. It may also contain excess oil that is scraped off by the scraping portion 64 and consequently prevents oil from entering or entering the combustion chamber.

The fifth ring 70 is an air / oil retaining ring. The first outer circumference 72 contacts the cylinder liner L, while the second outer circumference 74 has a through groove 76 formed therein, so that the lubricating oil While returning to the crank chamber, entry into the combustion chamber is prevented as well as blocking the turbo pressure from entering the crank chamber.

The sixth ring 80 is a final oil ring, which serves to scrape excess oil in the cylinder and return it to the crank chamber by the expansion force of the spring 84 and the action of the rail 86.

As such, when the piston is reciprocated by the operation of the engine, oil is prevented from entering the combustion chamber by the respective piston rings, and at the same time, the explosion pressure or the turbo pressure can be prevented from flowing into the crank chamber.

As a result, according to the piston for a two-cycle diesel engine of a railway vehicle according to the present invention, it is possible to block the oil flowing into the combustion chamber during the operation of the engine and at the same time to prevent the explosion pressure or turbo pressure from flowing into the crankcase fuel Is reduced, soot and nitrogen oxides are reduced, and the engine efficiency is increased, thereby improving product quality.

In addition, since the engine oil is prevented from intruding into the combustion chamber, the temperature rise of the engine oil or the flame thereof is prevented from being released to the outside, thereby preventing fire and environmental pollution, thereby improving reliability.

While a preferred embodiment according to the present invention has been described above, it will be understood by those skilled in the art that various modifications and changes can be made without departing from the scope of the appended claims.

Claims (4)

A cylinder liner is provided inside and reciprocates in a cylinder communicating with an air supply source, four receiving grooves are formed from the upper side of the outer side, and two receiving grooves are formed at the lower side to form the first to sixth receiving grooves. In the piston for the two-cycle diesel engine, the first to sixth ring is accommodated in each receiving groove, A plurality of passages are formed on an upper surface of the first ring inserted into the first accommodating groove of the main body to guide movement of the explosion pressure during an explosion stroke, and an inclined portion is formed on the upper side; An inclined portion is formed at each of the upper and lower sides of the third ring inserted into the third accommodating groove of the main body, and the outer periphery forms a flat surface for adsorption of oil; The fourth ring inserted into the fourth accommodating groove of the main body has an inclined portion formed on the upper side, and a scraping portion formed on the lower side to scrape oil off to prevent oil from flowing into the combustion chamber. A pocket groove for accommodating oil is formed; The fifth ring, which is inserted into the fifth accommodating groove of the main body, is continuously formed to be inclined downward at an upper portion of the outer circumference to prevent oil from flowing into the combustion chamber and to prevent turbo pressure from flowing into the crank chamber. A piston for a 2 cycle diesel engine, characterized in that it is integrally provided with a second outer circumference which is smaller than the circumference and the first outer circumference, and a plurality of oil through grooves are formed discontinuously. The piston for a 2 cycle diesel engine according to claim 1, wherein the inclination angle of the inclined portion of the first ring is 30 degrees. The piston for a 2 cycle diesel engine according to claim 1, wherein a difference between the diameters of the first outer circumference and the second outer circumference of the fifth ring is 0.2 mm to 0.6 mm. The piston for a 2 cycle diesel engine according to claim 1, wherein the radial protrusion difference between the first outer circumference and the second outer circumference of the fifth ring is 0.25 mm.

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