JPH0775919A - Oil passage machining method for engine crank shaft - Google Patents

Abstract

PURPOSE:To easily machine an oil passage by moving a tool, which has drilling teeth at the end and a tapered end mill therebehind so as to be recessed inside ranging from the drilling teeth, from the opening to a drilled end to open a hole. CONSTITUTION:At the first step of drilling, an oil passage 14 is drilled from the opening 16 of a main spindle bearer 11 and from the opposide side to a preset position. At the second step of cutting while moving a tool 17, which has drilling teeth 18 at the end and a tapered end mill 19 therebehind so as to be recessed inside ranging from the drilling teeth 18, from the opening 16 of the main spindle bearer to the drilled end at the first step, the oil passage 14 is opened. At the time, a curved portion is partially formed from the opening to the outer periphery of the main spindle bearer by the end mill 19. At the third step of cutting the outer periphery of the main spindle bearer while moving the tool 17 backward and moving the end mill 19 along the outer periphery of the main spindle bearer, the curved portion is formed as specified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing an oil passage of an engine crankshaft.

[0002]

2. Description of the Related Art In a crankshaft of an engine, lubricating oil supplied from a main gallery to a main bearing is guided to a crankpin portion through an oil passage inside the crankshaft, and a connecting rod is also mounted on the main bearing. Lubrication of the crank pin part is performed.

In order to improve the oil supply performance from the main bearing side to the crankpin portion, the oil passage 1 is provided eccentrically from the rotation center of the crankshaft 2 as shown in FIGS. 7 and 8, and the main bearing portion thereof is provided. It is considered that the opening 4 of the (journal portion) 3 is provided so as to be curved along the outer periphery of the main bearing portion 3.

According to this, the lubricating oil smoothly flows into the oil passage 1 from the groove (circumferential groove) of the main bearing due to the opening shape of the crankshaft which faces the rotation direction, and is sent to the crankpin portion 5 by the centrifugal force. (Japanese Patent Application No. 5-173
No. 080).

In processing the oil passage 1 as described above, a processing method as shown in FIGS. 9 and 10 is generally used.

That is, the oil passage 1 is halfway drilled from the crankpin portion side opposite to the opening 4 of the main bearing portion 3, and then the passage 1 is opened by drilling from the opening 4 side.

After this, the end mill 6 is applied from the direction perpendicular to the opening 4, and the end mill 6 is moved from a to b in FIG.
Then, a curved portion that continues to the outer periphery of the main bearing portion 3 is cut and formed by the tip portion thereof.

[0008]

However, with such a processing method, the oil passage 1 is drilled from the opening 4 side.
Since the curved portion is formed again by the end mill 6 after the hole is drilled to open the passage 1, the working process becomes complicated and the cost increases.

Further, a step is formed at the boundary between the drilling and the end milling, which interferes with the flow of the lubricating oil from the main bearing side into the oil passage 1 and causes a decrease in pressure. The amount of oil to the pin part may decrease.

An object of the present invention is to provide a processing method which solves such a problem.

[0011]

A first aspect of the present invention is a method for processing an oil passage that opens in a main bearing portion of an engine crankshaft and is connected to the outer periphery of the main bearing portion while the opening is curved. A first step of drilling a passage from the side opposite to the opening, and a tool having a drill tooth portion at the tip end thereof and a tapered end mill portion which is recessed inwardly connected to the drill tooth portion are provided at the opening side. To the drilling end of the first step to open and drill, and following the second step, the tool is retracted and the end mill portion is formed along the outer circumference of the main bearing portion to form a curved portion. The third step is to:

A second aspect of the present invention is a method for processing an oil passage that opens to a main bearing portion of an engine crankshaft and is connected to the outer periphery of the main bearing portion while the opening is curved, the oil passage being opposite to the opening. A first step of drilling from the side, and a curved shape leading to the drilling end of the first step by translating a tool having a tapered end mill portion that is concave inward from the outer periphery of the main bearing portion on the opening side. And a second step of cutting and forming the opening.

[0013]

In the first aspect of the invention, the oil passage is drilled from the side opposite to the opening side of the main bearing portion to a predetermined position by the first step of drilling, and then the drill tooth portion is provided at the tip portion and the drill tooth portion is provided behind the drill tooth portion. A tool having a tapered end mill part that is continuous with the inner part and is concave inward from the main bearing part opening side.
In the second step of cutting while moving to the boring end of the step, the oil passage is opened, and the end mill portion partially forms a curved portion from the opening to the outer periphery of the main bearing portion.

Then, while retreating the tool,
A predetermined curved portion is formed by the third step of cutting the outer circumference of the main bearing portion while making the end mill portion along the outer circumference of the main bearing portion.

According to the second aspect of the invention, the tool having the tapered end mill portion which is bored in the oil passage from the side opposite to the opening side of the main bearing portion to a predetermined position by the first step of drilling and thereafter is concaved inward. By the second step of cutting while being translated from the outer periphery on the opening side of the main bearing portion, that is, by the end mill portion, the curved portion is formed on the outer periphery of the main bearing portion, and from the curved portion to the drilled end of the first step. A connecting opening is formed.

In this case, the length and shape of the curved portion are determined by the shape of the end mill portion.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a crankshaft 10. Reference numeral 11 is a main bearing portion, 12 is a crank pin portion, and 13 is a balance weight.

The oil passage 14 for guiding the lubricating oil supplied to the main bearing (not shown) to the crank pin portion 12 is located at a position eccentric from the rotation center of the crank shaft 10 and the main bearing portion 11 is provided.
From the side to the crank pin portion 12 side, the oil hole 15 is opened to the pin outer circumference, and the opening 16 is connected to the outer circumference of the main bearing portion 11 while curving in the circumferential direction.

The processing of the oil passage 14 is performed by referring to FIGS.
First, a drill is used to drill from the crankpin portion 12 side to a predetermined position in the main bearing portion 11, and the oil hole 1
5 is formed (first step).

The oil hole 15 fills the processing port, and a hole is separately formed in the crank pin portion 12 to open on the outer circumference of the pin.

Next, an oil hole 15 is opened from the main bearing portion 11 side to the outer circumference of the main bearing portion 11 using a tool 17 having a drill tooth portion and an end mill portion.

As shown in FIG. 4, the tool 17 is a cutting tool having a drill tooth portion 18 at the tip portion and a tapered end mill portion 19 which is recessed inwardly in succession to the drill tooth portion 18 behind the drill tooth portion 18 and is used for drilling holes. And end mill processing can be performed at the same time.

The tip of the tool 17 is moved forward (from a to b in FIG. 3) toward the drilling end of the oil hole 15 from the direction substantially tangential to the outer periphery of the main bearing 11, and the drill tooth portion 18 and the end mill portion 19 are moved. By drilling and cutting the main bearing portion 11, the oil is penetrated and opened at the drilled end of the oil hole 15. On this occasion,
Along with the opening 16, the tapered end mill portion 19 that is concave inward is processed into a curve from the opening 16 to the outer circumference of the main bearing portion 11 (second step).

Then, subsequently, the outer periphery of the main bearing portion 11 is circumferentially cut by the end mill portion 19 to form a gentle curve (arc from the center of the main bearing portion 11) continuous to the outer periphery of the main bearing portion 11. The curved portion 21 having a large angle θ is formed.

In this case, the end mill portion 19 is connected to the main bearing portion 1
1 The tool 17 is moved backward along the outer periphery (b to c in FIG. 3), that is, the tool 17 is moved backward while changing the direction of the tool 17 (third step). this is,
It is also possible to rotate the crankshaft 10 side.

In this way, the drill tooth portion 18 is
By using the tool 17 having the tapered end mill portion 19 which is recessed inwardly in succession to the drill tooth portion 18 behind, the oil passage 14 having the required shape can be easily machined without complicating the machining process.

Further, since the main bearing 11 side can be machined with one tool 17, the machining time can be shortened and the cost can be reduced.

Further, since the opening 16 and the curved portion 21 can be processed to be the same, there is no step at the boundary between them, so that the lubricating oil smoothly flows into the oil passage 14 from the main bearing side, and the oil passage is formed. 14 high refueling performance can be secured.

Since the curved portion 21 is cut by the end mill portion 19 while the tool 17 is retracted, it is possible to perform the machining without increasing the diameter of the tool 17. That is, when it is attempted to perform machining only in the first and second steps using the tool 17 in which the outer diameter is increased and the curvature of the end mill portion 19 is increased without using the third step, as shown in FIG.
If the distance D between the balance weights 13 shown in FIG. 2 is smaller than the diameter of the tool 17, they may come into contact with each other, but by using the third step, it is not necessary to increase the outer diameter of the tool 17, It is possible to prevent the contact between 17 and the balance weight 13.

FIGS. 5 and 6 show another embodiment of the present invention. Similar to the above embodiment, first, a hole is drilled from the crank pin portion 12 side to a predetermined position in the main bearing portion 11 by a drill, The oil hole 15 is formed (first step).

Next, cutting is performed using a tool 30 having a tapered end mill portion 31 which is recessed inward from the main bearing portion 11 side.

In this case, the tool 30 is positioned on the outer peripheral side of the main bearing portion 11 in parallel with the direction toward the drilling end of the oil hole 15 (a in FIG. 5), and moved parallel to the outer periphery of the main bearing portion 11 ( In FIG. 5 b), the main bearing portion 11 is provided by the end mill portion 31.
By cutting the oil, a curved portion 33 is formed which is open at the drilled end of the oil hole 15 and which is continuous from the opening 32 to the outer periphery of the main bearing portion 11 (second step).

According to this, the curved portion 33 has a relatively small angle θ of the arc from the center of the main bearing portion 11, but the curved portion 3
When it is desired to increase 3, the process of the third step of the above embodiment may be added.

Further, although the opening on the side opposite to the curved portion 33 side is shaved, even in this case, sufficient oiling performance can be obtained as compared with the case where the curved portion 33 is not provided.

[0036]

As described above, the first aspect of the present invention is a method for processing an oil passage that opens to the main bearing portion of an engine crankshaft and is connected to the outer periphery of the main bearing portion while the opening is curved. A first step of drilling a passage from the side opposite to the opening, and a tool having a drill tooth portion at the tip end thereof and a tapered end mill portion which is recessed inwardly connected to the drill tooth portion are provided at the opening side. From the first step to the perforation end of the first step to open and perforate,
By the third step, following the second step, in which the end mill portion is cut along the outer periphery of the main bearing portion while the tool is retracted to form a curved portion, the oil passage can be easily processed, and the cost can be reduced. It is possible to form an oil passage having excellent refueling performance.

A second aspect of the present invention is a method for processing an oil passage that opens to a main bearing portion of an engine crankshaft and is connected to the outer periphery of the main bearing portion while the opening is curved. The oil passage is opposite to the opening. A first step of drilling from the side, and a curved shape leading to the drilling end of the first step by translating a tool having a tapered end mill portion that is concave inward from the outer periphery of the main bearing portion on the opening side. By the second step of cutting and forming the opening of, the oil passage excellent in oil supply performance can be easily processed as in the first invention,
The number of processing steps can be reduced.

[Brief description of drawings]

FIG. 1 is a side view of a crankshaft.

FIG. 2 is a diagram illustrating processing of an oil passage according to an embodiment.

FIG. 3 is a processing explanatory view from the side surface thereof.

FIG. 4 is a cutting tool diagram.

FIG. 5 is an explanatory view of processing an oil passage according to another embodiment.

FIG. 6 is a processing explanatory view from the side surface thereof.

FIG. 7 is a configuration diagram of an oil passage.

FIG. 8 is a side view thereof.

FIG. 9 is an explanatory view of conventional processing.

FIG. 10 is an explanatory view of conventional processing.

[Explanation of symbols]

 11 Main Bearing Part 12 Crank Pin Part 14 Oil Passage 15 Oil Hole 16 Opening 17 Tool 18 Drill Teeth 19 End Mill Part 21 Curved Part 30 Tool 31 End Mill Part 32 Opening 33 Curved Part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyo Hasegawa 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd.

Claims (2)

[Claims] 1. A method of processing an oil passage that opens in a main bearing portion of an engine crankshaft and is connected to the outer periphery of the main bearing portion while the opening is curved, wherein the oil passage is drilled from a side opposite to the opening. A first step of drilling,
A second tool for moving a tool having a drill tooth portion at the tip thereof to the rear of the drill tooth portion and having a tapered end mill portion that is concave inwardly is moved from the opening side to the drilling end of the first step to open and drill. A method for machining an oil passage of an engine crankshaft, which comprises a step and a third step, following the second step, the end mill portion is cut along the outer circumference of the main bearing portion while the tool is retracted to form a curved portion. 2. A method for processing an oil passage which opens to a main bearing portion of an engine crankshaft and is connected to the outer periphery of the main bearing portion while the opening is curved, wherein the oil passage is drilled from a side opposite to the opening. A first step of drilling,
From a second step in which a tool having a tapered end mill portion that is recessed inward is translated from the outer periphery of the main bearing portion on the opening side to cut and form a curved opening that leads to the drilled end of the first step. Engine crankshaft oil passage machining method.