JPS62203653A - Centrifugal casting method for gear - Google Patents

Abstract

PURPOSE:To simplify casting process of a gear and to shorten casting time by pouring a Cu alloy in a centrifugal casting mold and pouring a cast iron before cooling of the Cu alloy poured, to adhere as melting a gear teeth part and a body part as solid casting. CONSTITUTION:A flange of a rotor is fixed as setting into a dent part 13 of a lower mold 11 for the casting mold 12, forming of the upper mold 10 and the lower mold 11. Next, the molten Cu alloy is poured into a casting cavity while rotating round the axis (0) as center, to form the gear teeth part 14 of the gear by the centrifugal casting. In succession, the number of rotation is raised up, and the molten cast iron is poured while the condition, of which the gear teeth part 14 is yet at high temp., to form the body part 15 of the gear by the centrifugal casting. Then, the cast iron having high temp. melts Cu alloy, which advances to cool from the outer circumference, at the joining face 16 of the both 14, 15 and welds surely as melting mutually. Therefore, the gear is surely joined, and has no blow hole and has high mechanical strength.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a method for centrifugal casting of gears.

(Prior art) In conventional VJ manufacturing of gears, as shown in FIG. The incisor portion 5 made of copper alloy is centrifugally cast by pouring molten copper alloy and casting.

For this purpose, a boss 8 is attached to the lower mold 3 in order to hold the vJ iron main body part 1 set in advance so that it does not move into the mold.
116, and is further filled with anti-sand 7 to prevent hot water from entering the main body part 1 when pouring the copper alloy, and dovetail-shaped protrusions 8 are provided at multiple locations on the outer periphery of the main body part 1 to prevent rotation. made it stand out.

Further, the riser 9 remained in the incisor portion 5.

(Problems to be Solved by the Invention) As mentioned above, in order to cast the copper alloy incisor part 5 on the cast iron main body part 1 by casting, the structure of the cast iron main body part 1 and the VJ molding are complicated. There are problems such as the trouble of setting the anti-sand 7 and leaving the copper alloy riser 9. Furthermore, due to the temperature difference between the pre-cast main body part 1 and the molten copper alloy 5, the joining part of the two parts may There was a problem in that it was easy to do this.

The present invention aims to eliminate these problems and simultaneously cast the iron main body part and the copper alloy incisor part integrally using a simple method.

[Structure of the invention]

(Means for Solving the Problems) The present invention involves centrifugally casting a gear incisor by injecting molten copper alloy into a centrifugal casting mold, and then pouring molten cast iron into the same casting mold before the copper alloy has cooled. The main body of the gear is then centrifugally cast, the incisors and the main body are welded together at the joint surfaces, and the outer incisors made of copper alloy are centrifugally cast! Following the 7i construction, by centrifugally casting the inner peripheral main body part made of copper alloy in the same mold, the joint surfaces of the incisor part and the main body part were integrally FJl, making the mold complicated, setting anti-sand, and pressing. By eliminating the need for hot water and simultaneously casting the incisor part and the main body part, the production process is simplified by eliminating the "su" formation caused by temperature differences l)
This is an attempt to shorten the time.

(For 0) The present invention is centrifugal! The high-temperature copper alloy centrifugally produced in 5-shape trI and the high-temperature cast iron subsequently centrifugally produced in #1 are welded to each other at their joint surfaces. In addition, at this time, since the outer periphery composition ↑ has a higher specific gravity than cast iron, the two do not mix into H at the joint surface.

(Example) An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

(1) As shown in FIG. 1, a casting mold 12 formed by an upper mold 10 and a lower mold 11 is fixed by fitting a rotary flange into the recess 13 of the lower mold 11,
The incisor portion 14 of the gear is formed by centrifugal casting by injecting molten copper alloy into the casting space while rotating at or, p, and m.

(2) Next, as shown in Figure 2, the number of revolutions is increased to 6.
50 r, p, and m, molten cast iron is injected while the upper incisor portions 14 are in a high temperature state, and the main body portion 15 of the gear is formed by centrifugal casting. At this time, the copper alloy of the incisor portion 14 which is in a high temperature state is 1150°C, and the molten private railway is 1350°C, so there is a small temperature difference, and the high temperature cast iron at the joint surface 16 of both melts the copper alloy which is cooling from the outer periphery. It is securely welded to the Further, the specific gravity of the copper alloy on the outer periphery is 8.1, and the specific gravity of the cast iron on the inner periphery is 7.5-7.
6, the joining surfaces of the inner and outer peripheries are not disturbed by H due to centrifugal casting.

〔Effect of the invention〕

According to the present invention, a molten copper alloy is injected into a centrifugal casting mold to centrifugally cast a gear incisor part, and before the copper alloy has cooled down, molten cast iron is injected into the same casting mold to continue the gear body part. In order to create centrifugal vI and weld the incisor part and the main body part together at the joint surface, the incisor part of the gear and the main body part of the gear are successively poured into the same casting mold and manufactured in succession. This simplifies the casting process and greatly reduces casting time. Furthermore, since the incisor portion and the main body portion are welded together in a molten state, the connection is reliable and there is no possibility of cracking, resulting in high mechanical strength.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams of a manufacturing process showing one embodiment of the present invention, and FIG. 3 is an explanatory diagram of a conventional method. 12...Centrifugal casting mold, 14...Gear incisor part, 15...
Tooth width body part, 16...joint surface.

Claims (1)

[Claims] (1) Inject molten copper alloy into a centrifugal casting mold to centrifugally cast the incisor teeth of the gear, and before the copper alloy has cooled down, pour molten cast iron into the same casting mold and then centrifugally cast the main body of the gear. A centrifugal casting method for gears, characterized by welding the incisor portion and the main body portion together at the joint surface.