KR810001924B1 - Piston for internal combustion engine - Google Patents

Abstract

The direct injection diesel engine piston has the crown region(3) carrying two piston rings(8) and has the piston pin bosses(4) attached. A skirt region(7) is separately located in the bore & also has piston pin bosses incorporated in it. The crown & skirt regions are held relative to each other and the connecting rod(19) by means of the piston pin(13). Shelves are formed inside the piston skirt and are inclined upwards, towards the top of small end boss of the rod. The purpose of the shelves is to guide lubricant, sprayed up from piston cooling jets in the crank case, towards the small end bosses and against the underside of the crown.

Description

Pistons of internal combustion engines

1 is a longitudinal sectional view of a cylinder of an internal combustion engine having an axially movable piston therein;

2 is a cross sectional view of the cylinder and piston by the line I-I of FIG.

3 is a longitudinal sectional view of a cylinder of an internal combustion engine having an axially movable piston therein and at least one guide surface with a hill-shaped ridge therein;

4 is a cross sectional view of a cylinder and piston by line II-II of FIG.

The present invention relates to a piston of an internal combustion engine, in particular a diesel engine, having a mantle connecting the piston head to the lower part of the piston and being pivotally coupled to the piston pin shaft portion for the connecting rod via the lower part of the piston.

Particularly in modern internal combustion engine structures, good combustion of the fuel-air mixture is achieved when a combustion chamber temperature distribution is performed in which the combustion chamber is heated to a significantly higher temperature than the bottom of the combustion chamber at the combustion chamber opening, with sufficient combustion air being well filled in the combustion chamber. It is well known that it is possible. Such a temperature distribution is obtained by providing a heat insulating section for suppressing heat conduction in the combustion chamber opening, in particular, between the combustion chamber and the mantle of the piston, for example by spraying oil to release heat.

Known pistons for internal combustion engines of this type have a rotationally symmetric, almost spherical combustion chamber in favor of their piston heads, which are arranged against the ring support between the combustion chamber and the so-called mantle supporting the ring support. It has a heat insulating part to insulate. In this case, the said heat insulation part manufactured as an insert corresponding to a combustion chamber shape is attached by piston or its mantle indentation, and it is produced as what is called a burner part which tightens a combustion chamber opening. The part opposite the ring-shaped support of the piston is manufactured as the lower part of the piston, which is pivotally coupled to the piston pin bearing part via the piston pin. In this piston, it has an extremely short circumferential surface, but only a ring-shaped support supports a piston ring which seals it against the cylinder wall, in which case the piston itself is also subjected to a vertical force that is pivotally coupled to the piston bearing. It is supported by the cylinder by the sliding shoe which accommodates it. The release of heat generated by the combustion of the fuel-air mixture is carried out mainly in the cylinders, via the piston lower shaft, and the sliding shoe, in the cylinder and here as the cooling system of the internal combustion engine. Experiments using this type of piston have shown that it is desirable to release heat even more quickly, especially in an internal combustion engine capable of high load operation (Specification of German Patent Application Publication No. 1567013).

In order to satisfy such rapid heat dissipation, it is known to cause cooling oil to be sprayed from a nozzle arranged in a crank chamber in a piston mantle provided between the ring-shaped support and the lower portion of the piston in the same piston. Due to the good cooling of the mantle, the cooling oil fraction injected from the nozzle to the piston by the ring-shaped cutting part provided in the mantle is divided into two sets, one in the cutting between the ring support and the mantle, and the other along the mantle. Guided to the lower part of the piston. However, in this case also the whole of the first described turn of the piece must be cooled down to the high temperature of the piston chamber and the so-called low temperature. Partial temperature distribution is not obtained and moreover the heat release from the lower piston and piston pin shaft part. Such cooling oil does not carry out it quickly enough (the specification of the Federal Republic of Germany Patent No. 2007801).

An object of the present invention is to improve the piston for an internal combustion engine so as to produce a high temperature range at the opening of the piston chamber by a simple method, and to obtain a desired temperature distribution which causes a so-called low temperature range at the bottom of the combustion chamber and the piston bearing.

According to the present invention, this object is concluded by performing the following in the piston of the type described first. That is, according to the present invention, at least one guide surface is provided in the range of the piston pin shaft bearing portion because of cooling or lubricant, for example, oil, which is injected from the crank seal of the internal combustion engine toward the piston. Cooling or lubricant is passed through the piston pin bearing part while simultaneously passing through the piston pin in contact with the piston pin at the lower part of the piston and the piston bearing part.

According to this method, a desired temperature distribution is obtained in the combustion chamber, whereby the exhaust gas emissions can be reduced together with the complete combustion of the flue-air mixture. From the bottom of the combustion chamber to the sliding shoe from the lower part of the piston to the sliding shoe, and from here through the cylinder, the heat load on the piston is not only reduced by the heat dissipation of the internal combustion engine's cooling system but also the heat dissipation from the piston in question is relatively large. It is done quickly as long as there is a heat conductive surface. Moreover, part of the heat is released to the cooling oil directly or indirectly by the injection oil, whereby the cooling action is significantly increased. Another advantage of the present invention is that the cooling or spraying oil is directed to the piston pin bearing part, which is not only cooled but also lubricated, which is of great importance for the lifetime of the piston and also the internal combustion engine.

According to a preferred embodiment of the present invention, one guide surface or guide rib is provided on the main surface of the sliding shoe symmetrically with respect to the piston pin bearing part.

This arrangement of the guide surfaces or guide ribs ensures that the jet coolant to be guided to the piston pin bearing part is guided and collected after cooling the jet or coolant to be cooled. It can be turned to oil.

In one embodiment of the present invention, the free surface of the guide surface or guide rib reaches almost the piston pin bearing part in order to guide the injection or cooling oil to where it should be cooled or lubricated and discharge it from there again.

According to an embodiment of the present invention, each guide surface or guide rib is installed on the circumferential surface of the sliding shoe in an advantageous manner, and the jetting or cooling oil is supplied to the piston bearing part even during the movement of the piston moving toward the crank chamber. Is maintained.

In this way, the piston is lubricated independently of the piston stroke and the necessary oil is supplied to the lubricated part of the piston.

In order to configure the sliding shoe, in particular, to make it simple, the sliding shoe may have a guide surface or guide rib extending in a plate shape around the piston pin shaft part when only one guide surface or guide rib is used. have.

This configuration of the sliding shoe is simple in its manufacture and at the same time the injection or cooling oil is not only isolated from the wall or the wall by the shielding action of the cylinder wall portion located in the axial direction of the piston pin of the piston pin bearing part, It has the advantage that it enters the cooling or lubricant of the internal combustion engine, for example oil.

Especially in pistons of large diameter pistons, for example, in powerful internal combustion engines, cooling or lubricating oils are classified in the piston pin shaft part and the lower part of the piston in spite of the presence of guide surfaces or guide ribs in the range of the piston pin bearing part. The bottom surface is rarely reached throughout, resulting in dangerous temperatures somewhere in their part. According to another embodiment of the present invention, a guide surface is provided on a sliding shoe pivotally coupled to a piston pin bearing portion so that the free end of the guide surface almost reaches the piston bearing. .

In order to ensure that the cooling or lubricant reaches the pivot point of the piston pin in the sliding shoe, according to one embodiment of the present invention the bottom of the sliding shoe guide surface reaches at least the pivot point of the piston pin in the sliding shoe.

Next, the present invention will be described with reference to the embodiments shown.

The piston 1 for an internal combustion engine, for example a diesel engine, has a ring head and a mantle 3 having a piston head mainly configured as a ring-shaped support 2 and a piston lower part 5 supporting the piston head and having a piston pin bearing portion 4 thereon. It consists of a sliding shoe (7) which guides the support in the cylinder (6) and receives the vertical force resulting from the working stroke movement of the piston and is pivoted on the piston pin bearing. In this case it has a circumferential surface as necessary to accommodate the piston ring 8 which seals the extremely narrow ring-shaped support 2 against the cylinder 6, but the piston head, which has not been passed, is suitably rotationally symmetrical in this case. In order to simplify the structure, it has a spherical combustion chamber 9 and its bottom surface 10 is within the range of the lower piston 5 and the other chamber 11 of the combustion chamber 9 is the mantle of the piston 1. (3) Insulation is heat-insulated by the heat insulating part 12 which is simply abbreviated. The lower piston 5 held by the piston pin 13 in the piston pin bearing portion 4, such as the sliding shoe 7, can be manufactured as a bipartite portion 14 having a pivot space 15 due to the piston pin. In addition, the sliding shoe itself can be manufactured as a molding wheel member which has a closed mantle 16 in the form of a bowl or a dish or has a sliding jaw (not shown) disposed at its end.

In the configuration of the sliding shoe 7 shown in FIGS. 1 and 2, the sliding shoe is a main type and at least one pivot space 17, 18 in the range of the longitudinal axis Z of the piston pin 13. It is supported by the end part of the connecting rod 19 inserted in the piston pin 13 of the pin shaft part 4. In addition to the pivot spaces 17 and 18, the sliding shoe 7 has at least one guide surface suitably guide ribs 21 between the inner circumferential surface 20 and the piston pin bearing portion 4, which is wet. It is provided in the inner periphery of Dongshu, and the free end part 22 is facing the bearing part 4. This guide rib 21 is arranged on the inner circumferential surface 20 of the sliding shoe 7 as follows. That is, the guide rib 21 collects cooling or lubricants such as oil 25 injected from the crank chamber 24 to the piston 1 by the nozzle 23, and collects the piston pin bearing 4 and the lower part of the piston. By the guide surface of the guide rib toward the oil can be guided around the piston pin bearing portion (4). Thus, on one side, the bottom face 10 of the combustion chamber 9, that is, the lower part of the combustion chamber and the lower part of the piston 5, on the other side, the dividing part 14, the piston pin 13 and the piston pin bearing part 4 are sufficiently formed. The oil 25 is supplied, further cooled and lubricated. In particular, in order to allow this lubrication or coolant, i.e., oil 25, to return to the source after cooling and lubrication of the part, the second guide rib 27 is symmetrically symmetric with respect to the piston pin bearing 4. It is arranged on the inner circumferential surface 20 of the sliding shoe 7, and the free end 28 of the shoe also reaches the position of the piston pin bearing part 4, whereby the oil 25 coming out of the bearing part 4 is It is collected again and returned to the oil system of the internal combustion engine, for example oil. In this case, the inclination angle of the second guide ribs 27 may be equal to the inclination angle of the first guide ribs 21 described above, but the two guide ribs 21 and 27 have different inclination angles. In some cases, for example, it is also possible to produce a shape of the wing, which is advantageous for a separate flow movement. In addition, the classification of the oil 25 injected from the nozzle 23 in order to ensure that the spray or coolant, i.e., the oil 25 reaches the portion to be cooled or lubricated of the piston 1, is divided into the longitudinal center axis of the cylinder 6. When the piston 1 rises and falls relative to X, the oil 25 is inclined so as to be guided over almost the entire guide surface of the first guide rib 21. Thus, the 2nd guide rib 27 is also arrange | positioned so that the collected oil 25 may return to the oil which is not shown in figure. In this configuration, the guide ribs 21 and 27 are inclined excessively in a large amount or excessively to one side so that the injection or coolant, or oil 25, reaches the lower part of the piston 5, whereby The circularity of the sealing surface of the piston 1 is prevented from being damaged.

In the embodiment of Figs. 1 and 2, the sliding shoe 7 is configured in a main shape, and the mantle 16, which is guided and slides along the cylinder 6, has a circular shape around the piston pin bearing part 4. Surrounded by In this embodiment of the sliding shoe 7, the guide ribs 21/27 extend toward the bearing portion 4 in an arc shape without being in contact with the bearing portion 4.

However, the sliding shoe 7 is also constituted as a molding wheel member in which sliding jaws are provided at the free end in the range of the transverse center plane Y through the bearing part 4, and the molding slide member 7 is a cylindrical sliding shoe 7. Likewise, it is also possible to pivotally couple the piston pin bearing portion (4). In addition, the guide ribs 21 and 27 are formed in a dish shape, and these dish members surround the entire piston pin bearing part 4 in an arc shape, and these dish members are formed in the piston pin bearing part 4. It is also possible to provide the lower portion 5 of the piston 5 and the cutting portion 29 for the dividing portions 14 and 30 of the connecting rod 19 extending around the cross-section. In the inner circumferential surface 20 of the sliding shoe 7 of the singular or plural guide ribs 21, 27, the connecting portion is the transverse center of the sliding shoe 7 as in the embodiment of FIGS. 1 and 2. It is provided at or below or above a high order point between the plane Y and the durable wall 20.

The embodiments of FIGS. 3 and 4 are at least one guide rib 21, 27, that is, firstly oil 25, whether or not merely installed in the sliding shoe 7 with respect to the embodiments of FIGS. 1 and 2. The only difference is that the guide rib 21 supplied with) has the functional ridges 31. This ridge 31 facing the fractionation side of the oil 25 has a range 32 to 35 of varying heights, of which radially inner end 22 of the guide rib 21. The range 32 adjacent to is at a higher position than the ranges 32 to 35 continuing behind it. In this case, `` high '' means that the 힁 cross-sectional area of the guide rib 21 is large. This highest range, ie from the cross section 36 to the cross section of the ridge 31, is radial and axial, i.e. decreases in the longitudinal and transverse direction of the piston pin 13 and finally at the base or range 35 of the ridge. To reach. Although the ranges 33 to 35 shown in FIG. 4 extend in an arc shape, they are not in the center of the other type, that is, the ridges 31, but the grooves of which the edges are raised most. It is also possible to give a wing shape. In this case, what is important in the configuration of the ridge 31 is that the ridge has a function of distributing oil 25 along the longitudinal axis of the piston pin 13.

Claims (1)

In a piston of an internal combustion engine having a mantle that couples a piece tuck head to a lower piston, and pivotally coupled to a piston pin bearing portion via a piston lower portion, the crank chamber 24 of the internal combustion engine within the range of the piston pin bearing portion 4. At least one guide surface 21, 27 of the cooling or lubricant 25 sprayed from the piston to the piston pin 1 so that the cooling or lubricant is applied to the lower part 5 of the piston 1 and the piston pin bearing part. A piston of an internal combustion engine, characterized by flowing along (13) and passing around a piston pin bearing part.

Images