JPS6315559Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piston that can slide in a sealed manner within a cylinder bore of an internal combustion engine, compressor, etc.

Regarding pistons for internal combustion engines, aluminum alloys such as AC8P are conventionally used in such pistons, but due to seizure in the sliding part between the piston and cylinder bore and combustion of the air-fuel mixture in the combustion chamber. There are problems with vibration and hammering noise caused by the resulting explosive force. In order to solve these problems, efforts have been made to form grooves on the outer circumferential surface of the piston to maintain a lubricating oil film, and to increase the rigidity of the cylinder block. However, such striations are cumbersome, and increasing the rigidity of the cylinder block often increases the weight of the engine, which tends to deteriorate the fuel efficiency of the engine.

The object of the present invention is to provide a piston that does not require the above-mentioned striations, increases the rigidity of the cylinder block, and does not increase the weight of the engine. That is, the present invention is a piston in which carbon fiber-reinforced plastic is bonded to the skirt portion in such a manner that the fibers are oriented crosswise to each other so that the direction of the fibers is inclined with respect to the sliding direction of the piston.

The piston according to the present invention will be explained below with reference to the drawings. FIG. 1 is a side view showing a state of a piston for an internal combustion engine according to the present invention before carbon fiber reinforced plastic (CFRP) is bonded thereto. The piston 1 is machined or formed in the state shown in FIG. That is, when this piston 1 is fitted into a cylinder bore (not shown) bored in the cylinder block of an engine, the surface that slides on this cylinder bore, that is, the skirt portion 2 of the piston 1 has a smaller diameter than that of conventional pistons. is being completed. Next, the skirt portion 2
As shown in FIG. 2 with a mesh pattern to emphasize it, carbon fiber reinforced plastic 3 is laminated and bonded so that the gap between the outer peripheral surface of this carbon fiber reinforced plastic 3 and the cylinder bore is an appropriate size. ing. FIG. 2 is a front view showing a state in which the carbon fiber reinforced plastic 3 is laminated and bonded to the piston shown in FIG. 1, and the left half of the figure is a sectional view.

The carbon fiber reinforced plastic (FRP) 3 may be laminated by molding a thermosetting resin 32 such as polyimide or epoxy phenol resin onto a high-rigidity carbon fiber 31 by a hand lay-up method, or by a preform mold die method or SMC. A pressure molding method using a mold such as a method may also be applied. Here, high-rigidity carbon fibers 31 are arranged at an angle with respect to the sliding direction of the piston 1, and are arranged at right angles to each other so that they intersect with each other, for example, so that the fibers each have an inclination of 45 degrees with respect to the piston sliding direction. Orient it so that it crosses the

By laminating and adhering the carbon fiber reinforced plastic 3 to the skirt portion 2 of the piston 1, when the piston 1 slides within the cylinder bore, the high-rigidity carbon fiber 31 acts as a solid lubricant to prevent ignition between the piston 1 and the cylinder bore. sticking is prevented. Further, the slight irregularities between the high-rigidity carbon fibers in the carbon fiber reinforced plastic 3 exhibit a lubricating oil retaining function, further enhancing the above-mentioned seizure prevention function and reducing lubricating oil consumption. Further, the resin 32 of the carbon fiber reinforced plastic 3 absorbs vibration and noise when the piston 1 collides with the cylinder bore. Therefore, seizure during sliding of the piston can be prevented and noise can be reduced.

Furthermore, when the piston of the present invention is used in an internal combustion engine, it is possible to reduce friction loss by reducing friction between the piston 1 and the cylinder bore, and to reduce weight by using carbon fiber reinforced plastic 3, which has a specific weight much smaller than metal. This means that the piston 1
It is possible to increase the output of engines equipped with this and reduce fuel consumption. Furthermore, when conventional aluminum alloy pistons are used, even if the pistons are formed with grooves, there is a risk of seizure if the cylinder block is made of high-silicon aluminum alloy. By using this, concerns about seizure can be greatly reduced, and moreover, there is no need for complicated scratch processing. Furthermore, vibrations and hammering noises caused by the explosive force and inertial force of the internal combustion engine are absorbed by the carbon fiber reinforced plastic resin and are greatly reduced. In addition, since the carbon fibers are oriented so that they intersect with each other and are inclined with respect to the piston sliding direction, the unevenness between the fibers is evenly distributed over the outer peripheral surface of the piston, and its lubricating oil retention function is uniform. The lubrication function is further improved.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the state of the piston according to the present invention before bonding carbon fiber reinforced plastic, and FIG. 2 is a front view showing the state of the piston according to the present invention after bonding carbon fiber reinforced plastic. DESCRIPTION OF SYMBOLS 1...Piston, 2...Skirt portion, 3...Carbon fiber reinforced plastic, 31...High rigidity carbon fiber, 32...Resin.

Claims (1)

[Scope of utility model registration request] The skirt part is made of carbon fiber reinforced plastic.
A piston characterized in that the fibers are bonded and oriented crosswise to each other so that the direction of the fibers is inclined with respect to the sliding direction of the piston.