JPS6079140A - Piston engine for aluminum cylinder - Google Patents

Abstract

PURPOSE:To improve the durability of the inner face of cylinder easily with low cost by applying honing finish on a plasma coating layer of iron or iron and chromium provided on the inner face of aluminum cylinder. CONSTITUTION:An aluminum cylinder 1 and a crank case 2 are mounted on a rotary table 3 then rotated through a rotary shaft 4. An arc generator 5 and a metal powder feeder 6 constituting a plasma coating system is inserted into the cylinder 1 from above, to spray molten metal blast 7 through said arc generator 5 and metal powder feeder 6 onto the inner face of cylinder 1 thus to form a plasma coating layer 8. Thereafter, a honing system 9 is inserted into the cylinder 1 to apply honing finish onto the plasma coating layer 8. Consequently, the plasma coating layer 8 is adhered firmly to the inner face of cylinder 1 resulting in improvement of durability of the inner face of cylinder 1 easily with low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylinder inner surface structure in a piston engine having an aluminum cylinder.

In conventional piston engines with aluminum cylinders, the following surface treatment method was used to prevent wear on the inner surface of the aluminum cylinder.

1. Cast or fit a cast iron liner inside the aluminum cylinder. In this case, if there is a gap between the aluminum and the liner, there is a drawback that heat conduction becomes poor.

2. The aluminum cylinder is made of arsine, which is a high-silicon aluminum alloy containing 20% to 12% silicon, and a eutectic of aluminum and silicon is deposited on the inner surface. In this case, the entire surface of the piston must be plated with chrome or iron.

The problem with the above-mentioned conventional finishing process is that it is a complicated manufacturing process and is expensive.

The present invention provides an aluminum cylinder piston engine that solves the above-mentioned problems.

The present invention will be explained with reference to figures showing its manufacturing method.

In FIG. 1, an aluminum cylinder 1 and a crankcase 2 are placed on a rotary table 3. The rotating table 3 is rotated by a rotating shaft 4.

The plasma coating device consists of an arc generator 5 and a metal powder supply device 6, both of which are inserted into the cylinder 1 from above. The plasma coating device or the rotary table moves up and down by a sliding mechanism (not shown).

An arc of about 20,000'C is created by the arc generator 5, and the active gold is converted into argon,
The metal particles are supplied with a flow of inert gas such as helium, and are melted while passing through the arc, and are blown to the inner surface of the cylinder as a blast by the high-speed airflow, and are deposited on the inner surface of the cylinder. The cylinder 1 and the molten metal blast 7 are moved up and down relative to each other and the cylinder is rotated, so that the metal plasma coating can be applied over the entire surface in a spiral manner within the cylinder. The metal powder has a composition of iron, iron and chromium, or iron and molybdenum, etc., and has a thickness of 0.
．． 8 plasma coating layers of 1 tan to 0.3 vm are made.

Next, as shown in FIG. 2, the plasma-coated inner surface of the aluminum cylinder 1 is honed by vertically moving and rotating a honing device 9. The honing device 9 performs a finishing process on the inner surface of the cylinder 1 by removing, for example, the plasma coating layer 8 by 0.05 ttan to 0.1 ttan.

FIG. 3 shows a state in which a piston 10 having several piston rings 11, 11', . 12 is a crank mechanism.

In the piston engine of the present invention, in which the inner surface of the aluminum cylinder is honed to have a plasma coating layer of about 0.1 mm, the plasma coating layer firmly adheres to the inner surface of the cylinder and does not peel off during operation. Also, it fits well with the piston and piston ring,
There is no need to plate the piston surface, it is much more durable than the conventional anti-wear treatments mentioned earlier, it eliminates the pollution caused by traditional chrome plating, and the plasma coated and honed finish is much more durable than the conventional anti-wear treatments mentioned earlier. It is much easier and cheaper than any conventional wear prevention method.

In addition, the plasma coating process of the present invention has an inner diameter of 60+mn.
It can also be applied to small diameter cylinders.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing the state in which plasma coating is applied to the inner surface of an aluminum cylinder on the rotating table, and Figure 2 is an explanatory diagram showing the state in which honing is applied to the plasma coating layer of the aluminum cylinder on the rotating table. , FIG. 3 is a side sectional view showing an aluminum cylinder piston engine according to the present invention. 1 is an aluminum cylinder, 2 is a crankcase 3 is a rotary table, 4Fi is a rotating shaft, 5 is an arc generator, 6 is a metal powder supply device, 7 is a molten metal plasto, 8 is a coating layer,
9 is a honing device, 10 is a piston, 11 is a piston ring, and 12 is a crank mechanism.

Claims (1)

[Claims] A piston engine with an aluminum cylinder that has a honed finish on the inner surface of the cylinder with a plasma coating layer of iron, iron and chrome, or iron and molybdenum.