JPH0564567U - Groove shape of piston ring for internal combustion engine - Google Patents

Abstract

(57) [Abstract] [Purpose] By reducing the waviness of the ring groove due to the deformation of the piston that occurs within the expected operating time of the internal combustion engine, the disadvantages such as increase in blow-by gas amount and oil consumption amount are eliminated. In the groove shape of a piston ring for an internal combustion engine, the ring groove 2 is formed so that the positions of the piston thrust side T and the piston anti-thrust side UT undulate toward the crankshaft side rather than the positions of the piston front and rear sides F, R. , A shape that has been processed in advance.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a groove shape of a piston ring for an internal combustion engine.

[0002]

[Prior Art]

 Conventionally, the groove shape of a piston ring for an internal combustion engine is preliminarily machined so as to have a linear shape or a minimum waviness shape as shown in the piston appearance view of FIG. 4 and the ring groove development view of FIG.

[0003]

[Problems to be solved by the device]

 However, the conventional groove shape described above has a disadvantage that it is permanently deformed within the expected working time as shown in the ring groove development view of FIG. For details, as shown in the piston head external view of FIG. 6 and the piston external view of FIG. 7, when the internal combustion engine is operating, the piston 1 moves around the pin hole 3 due to the combustion gas pressure p applied to the piston head. However, as the piston 1 is permanently deformed, the ring groove 2 is also permanently deformed and wavy. That is, the position of the piston thrust side T and the piston anti-thrust side UT of the ring groove 2 is undulated toward the crankshaft side rather than the positions of the piston front and rear sides F, R. As a result, the sliding performance between the piston ring and the cylinder liner wall deteriorates, and problems such as increase in blow-by gas amount and oil consumption amount are promoted.

[0004]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the groove shape of the piston ring for an internal combustion engine according to the present invention will be described with reference to FIG. 1. The ring groove 2 has a piston thrust side T and a piston anti-thrust side UT. The shape is pre-processed so that the position undulates from the positions of the front and rear sides F and R of the piston toward the side opposite to the crankshaft.

[0005]

According to the above configuration, the waviness of the ring groove 2 due to the deformation of the piston 1 after the operation is offset by the waviness of the ring groove 2 provided in advance by the above configuration.

[0006]

【Example】

 An embodiment of the present invention will be described with reference to the partial cross-sectional external view of the piston of FIG. 1 and the ring groove development view of FIG. The piston 1 in the figure is provided with three piston rings and their ring grooves 21, 22 and 23 (note that the piston ring and ring groove need not be limited to three).

As shown in the ring groove development view of FIG. 2, these ring grooves 21, 22 and 23 are located at positions of the piston thrust side T and the piston anti-thrust side UT on the piston front and rear sides F and R, respectively. It has been processed in advance so that it swells to the side opposite the crankshaft.

According to the above-described embodiment, when the piston 1 is permanently deformed by the combustion gas pressure p during operation, it is caused by the undulation of the ring groove 2 previously provided by the above-mentioned configuration and the deformation of the piston 1. The waviness of the ring groove 2 is offset, the waviness of the ring groove is reduced, the sliding performance between the piston ring and the cylinder liner wall is improved, and the increase in blowby gas amount and oil consumption etc. can be suppressed. become able to.

By the way, the amount of waviness of the ring groove 2 given in advance by the present invention is preferably as follows. This will be described with reference to FIG. In the same figure, ~ indicates the amount of swell to the crankshaft side at the positions of the piston thrust side T and the piston anti-thrust side UT of the ring groove 2 during the operating time. Shows a prior art, and shows an embodiment of the present invention. Is aimed at the expected operating time X, and the positions of the piston thrust side T and the piston anti-thrust side UT of the ring groove 2 are swung a1 toward the counter crankshaft side rather than the piston front and rear sides F, R. It has been processed in advance. On the other hand, is aimed at X1 hour, which is less than the expected operation time X, and the positions of the piston thrust side T and the piston anti-thrust side UT of the ring groove 2 are set to be opposite to those of the piston front and rear sides F and R. It was pre-processed so that only a2 undulates toward the crankshaft (a1> a2). Therefore, comparing with and is ideal at first glance, but in this case, since a large swell a1 is generated in the initial stage of operation, the sliding performance between the piston ring and the cylinder liner wall is correspondingly increased. Decrease, which is one of the causes of the increase in blow-by gas and oil consumption at the beginning of operation. Therefore, it is appropriate to set a1 ≧ a2 ≧ (a1) / 2 as described above.

[0010]

[Effect of the device]

 As described above, according to the groove shape of the piston ring for the internal combustion engine according to the present invention, the ring groove 2 is located in the positions of the piston thrust side T and the piston anti-thrust side UT on the front and rear sides F and R of the piston. Since the shape is preliminarily processed so as to swell to the side opposite to the crankshaft, the swell of the ring groove 2 caused by the permanent deformation of the piston 1 due to the combustion gas pressure can be offset. As a result, it becomes possible to eliminate inconveniences such as an increase in blow-by gas amount and oil consumption during the expected operating time of the internal combustion engine.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional external view of a piston showing an embodiment of the present invention.

FIG. 2 is a development view of a ring groove according to an embodiment of the present invention.

FIG. 3 is a graph illustrating another embodiment of the present invention.

FIG. 4 is an external view of a piston showing a conventional technique.

FIG. 5 is a development view of a ring groove which is a conventional technique.

FIG. 6 is a piston head front view for defining each position of the ring groove.

FIG. 7 is a diagram illustrating a ring groove shape after the operation of the internal combustion engine in the related art.

FIG. 8 is a development view of a ring groove after the operation of the internal combustion engine in the related art.

[Explanation of symbols]

 1 Piston 2 Ring groove T Piston thrust side UT Piston anti-thrust side F Piston front side R Piston rear side

Claims (1)

[Scope of utility model registration request] 1. In a groove shape of a piston ring for an internal combustion engine, the ring groove 2 has a position where a piston thrust side T and a piston anti-thrust side UT are undulated toward the crankshaft side rather than positions on the front and rear sides F and R of the piston. As described above, a groove shape of a piston ring for an internal combustion engine, which is characterized by being preliminarily processed.