JPH108931A - Oil passage forming method for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate apprehension of infiltration of a fusing member in a hollow part of a pipe member to form an oil passage easily, in the case of forming the oil passage by casting the hollow pipe member at the time of casting of a cast member constituting an engine. SOLUTION: In an oil passage forming method for an engine, a pipe member 18 closing both end parts 18a, 18b is previously set up in a cast mold of a cast member 2L of the engine, lengths L1, L2 of the pipe member 18 are set so as to protrude both ends of a hollow part of this pipe member 18 outward from cutting work surfaces A, B, C after casting the cast member 2L, at cutting work time after casting the cast member 2L, both the end parts 18a, 18b of the pipe member 18 are cut of by cutting work, the hollow part of the pipe member 18 is made to communicate with the outside, and this hollow part is formed as an oil passage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an oil passage in an engine for forming an oil passage inside a casting member constituting the engine.

[0002]

2. Description of the Related Art Several oil passages are formed inside a motorcycle or an automobile engine. These oil passages are formed so as to connect between an oil pump provided in the engine and bearings and sliding parts inside the engine, and lubricating oil discharged from the oil pump passes through the oil passage. It is supplied to each bearing and sliding part.

Conventionally, there are two methods of forming an oil passage: a method of simultaneously casting out an oil passage using a thin core when casting a cast member such as a crankcase or a cylinder block, and a method of drilling after casting the cast member. A method of forming an oil passage by cutting.

However, in the method in which the oil passage is formed by casting, the diameter of the core cannot be made very small, so that it is difficult to form a thin oil passage, and it is also impossible to form a bent oil passage.

[0005] In the method of forming an oil passage by cutting, it is difficult to form a long and narrow hole, which makes mass production of the engine difficult. Further, in order to form a bent oil passage, cutting is performed by drilling from two directions. Since it is necessary to provide a troublesome configuration for closing at least one end of the passage with a plug member such as a cover or a bolt, the manufacturing cost of the engine is greatly increased.

Therefore, as disclosed in, for example, Japanese Utility Model Laid-Open Publication No. 64-44308, a method of casting a hollow pipe member at the time of casting a casting member such as a cylinder block and using the hollow of this pipe member as an oil passage as it is. There is.

[0007] According to this method, the oil passage can be easily formed without resorting to difficult cutting such as drilling, and the bent shape can be obtained without using any plug member such as a cover or a bolt. An oil passage can be formed.

[0008]

However, when an oil passage is formed by casting a hollow pipe member as described above, there is a concern that a molten material may enter the hollow of the pipe member and block the oil passage during casting. There is.

SUMMARY OF THE INVENTION The present invention has been made to solve this problem. When casting a hollow pipe member at the time of casting a casting member constituting an engine to form an oil passage,
An object of the present invention is to provide a method for forming an oil passage in an engine, which eliminates a concern that a molten material enters a hollow portion of a pipe member and can easily form an oil passage.

[0010]

In order to achieve the above object, an oil passage forming method for an engine according to the present invention is characterized in that a pipe member having both ends closed is formed of a cast member of an engine. Pre-installed in the casting mold, the length of the pipe member is set such that both ends of the hollow portion of the pipe member protrude outward from the post-cast cutting surface of the cast member, At the time of cutting, both ends of the pipe member are cut off by cutting, and the hollow portion of the pipe member communicates with the outside, and this hollow portion is used as an oil passage.

According to such an oil passage forming method for an engine, the molten material is prevented from entering the hollow portion of the pipe member at the time of casting of the cast member by the pipe member whose both ends are closed, so that the cast member is formed. Since the both ends of the pipe member are cut off at the same time as the cutting after the casting, and the hollow portion of the pipe member becomes the oil passage as it is, the oil passage can be formed very easily.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a left side view of an engine employing the oil passage forming method according to the present invention. The engine 1 is a single-cylinder four-cycle engine for a motorcycle, for example, and the left side in FIG.

The engine 1 has a cylinder block 3, a cylinder head 4, and a head cover 5 on a crankcase 2.
Are sequentially placed and fixed to each other.
The crankcase 2 is, for example, divided into two parts, left and right, and bearings 6 and 6 are provided on the left and right case halves 2L and 2R, respectively.
A crankshaft 9, a countershaft 10, and a drive shaft 11 are rotatably supported by these bearings 6, 7, and 8.

A primary reduction gear (not shown) is provided between the crankshaft 9 and the counter shaft 10, and a transmission including a constant mesh multi-stage gear is incorporated between the counter shaft 10 and the drive shaft 11. In addition, a generator for power generation, a balancer shaft for vibration reduction, an oil pump for lubrication, and the like are housed in the crankcase 2.

As shown in FIG. 2, an oil passage 13 is formed in the left case half 2L on the left side of the crankcase 2, for example. The oil passage 13 extends leftward in the ceiling wall 14 of the left case half 2L horizontally, then refracts at a right angle and extends vertically downward in the left side wall 15 to support the left end side of the drive shaft 11. 8. The end of the oil passage 13 is opened between the bearing 8 and the oil seal 16 so that the lubricating oil discharged from the oil pump flows into the crankcase 2 through the inside of the bearing 8.

The crankcase 2 is a cast member, and the oil passage 13 is formed simultaneously with the casting of the left case half 2L. The forming method is as follows.

First, a pipe member 18 bent at a right angle in accordance with the shape of the oil passage 13 is prepared. The material of the pipe member 18 is selected so as not to be melted or deformed by the temperature of the molten material when the left case half 2L is cast. For example, when the left case half 2L is made of an aluminum alloy, the pipe member 18 is made of steel.

Next, both ends 18a and 18a of the pipe member 18 will be described.
b is closed (see FIG. 3). This closing process is performed by crushing both ends 18a and 18b or by using a simple plug member at both ends.
This is performed by press-fitting or welding to 18a and 18b. After the pipe member 18 thus processed is previously set in a casting mold of the left case half 2L, the molten material is poured into the casting mold to cast the left case half 2L.

FIG. 3 is a longitudinal sectional view of the left case half 2L after casting and before cutting. As shown in this figure, the lengths L1 and L2 of the pipe member 18 from the bending portion 18c are shown.
It is necessary to set such that both ends of the hollow portion of the pipe member 18 after the casting of the left case half 2L are sufficiently protruded outward from the cut surfaces A, B, C of the left case half 2L.

The cutting surface A is a joining surface for tightly joining the right case half 2R to the left case half 2L, and is machined into a flat surface. The cutting surfaces B and C are press-fit surfaces of the bearing 8 and the oil seal 16, respectively, and are formed into cylindrical surfaces. The cutting surface D is a flat surface for determining the position of the transmission mounted on the drive shaft 11 in the axial direction.

When the casting of the left case half 2L is completed and the cutting surfaces A to D are cut, as shown in FIG. 4, the left case half 2L is located outside the cutting surfaces A to D. All the meat has been removed. Then, the right end 18a of the pipe member 18 is cut off simultaneously with the cutting of the cutting surface A, and the left end 18b of the pipe member 18 is cut off simultaneously with the cutting of the cutting surfaces B and C. For this reason,
The hollow portion of the pipe member 18 communicates with the outside, and this hollow portion becomes the oil passage 13 as it is.

As described above, according to the present embodiment, the pipe member 18 whose both ends 18a, 18b are closed is connected to the left case half 2
By casting at the time of casting L, the molten material is prevented from entering the hollow portion of the pipe member 18 at the time of casting,
The oil passage 13 can be formed very easily.

In the present embodiment, an example in which the oil passage 13 is formed in the crankcase 2 (left case half 2L) of the motorcycle engine 1 has been described. The oil passage forming method according to the present invention can be applied to the case where an oil passage is formed in the head 4, and the oil according to the present invention is applied not only to an engine for a motorcycle but also to an engine of an automobile or another vehicle. The passage forming method can be widely applied.

The method of the present invention can be applied to a method for forming not only an oil passage but also a passage for other uses. Further, the method of the present invention can be applied not only to an engine but also to a case where a narrow passage is formed inside another casting structure.

[0026]

As described above, according to the method for forming an oil passage of an engine according to the present invention, a pipe member having both ends closed is previously set in a casting mold of a casting member of an engine, and a hollow portion of the pipe member is formed. The length of the pipe member is set so that both ends of the cast member protrude outward from the cut surface of the cast member after casting, and both ends of the pipe member are cut off by cutting during cutting after casting of the cast member. The hollow portion of the pipe member communicates with the outside, and this hollow portion is used as an oil passage.

According to such an oil passage forming method for an engine, the pipe member whose both ends are closed prevents the molten material from entering the hollow portion of the pipe member at the time of casting the cast member. Since the both ends of the pipe member are cut off at the same time as the cutting after the casting, and the hollow portion of the pipe member becomes the oil passage as it is, the oil passage can be formed very easily.

[Brief description of the drawings]

FIG. 1 is a left side view of an engine employing an oil passage forming method according to the present invention.

FIG. 2 is a longitudinal sectional view taken along the line II-II of FIG.

FIG. 3 is a longitudinal sectional view of a left case half body after casting and before cutting, showing an embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a left case half body after cutting.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Crankcase 2L Left case half body which is a cast member of engine 13 Oil passage 18 Pipe members 18a, 18b Both end portions of pipe member 18c Bend portions of pipe member A, B, C Cutting machined surface L1, L2 Pipe member 18 length

Claims (1)

[Claims] 1. A pipe member having both ends 18a and 18b closed.
18 is previously set in a casting mold of a casting member (2L) of the engine 1, and both ends of a hollow portion of the pipe member 18 are cast members (2L).
L) The lengths L1 and L2 of the pipe member 18 are set so as to protrude outward from the cut surfaces A, B and C after casting of the cast member (L). A method of forming an oil passage for an engine, comprising cutting off both end portions (18a, 18b) of the pipe member (18) by cutting, and connecting the hollow portion of the pipe member (18) to the outside, and using the hollow portion as an oil passage (13).