JPH08320014A - Connecting rod and its manufacture - Google Patents

Abstract

PURPOSE: To facilitate manufacture of a connecting rod which has further strength by extending a groove on a division surfaces of a pair of division bodies made of sintered metal, which are prepared through division by a plane along an axis of a connecting rod, and connecting a pipe member in the groove followed by forge welding. CONSTITUTION: A division body 1 is made of sintered metal and previously produced through powder jig to a shape which is divided into two by a plane A-A along an axis O-O of a connecting rod 2. In a forging process, a pipe member 6 is arranged in a groove 4 of the division body 1. One division body 1 is arranged from an upper side of the division body 1 with a division surface 3 being directed downward. The division surfaces 3 of the upper and lower division bodies 1 abut each other. The pipe member 6 is sandwiched between the division bodies 1. The unner and lower paired division bodies 1 are set in a forging machine, and subjected to forging pressure. In mechanical process after forging process, each end of the pipe members is drilled by means of a drill along the axis O-O of the connecting rod 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting rod for connecting a piston of an engine to a crankshaft and a method for manufacturing the connecting rod.

[0002]

2. Description of the Related Art Generally, a connecting rod has a large end which is an end on the crankshaft side and a small end on the piston pin side, and a piston between the large end and the small end. It is necessary to form an oil supply passage for cooling or the like through the connecting rod.

Further, since a large force acts on the connecting rod due to the rotation of the engine and it moves at a high speed, it is advantageous in terms of engine performance to form it with a material having a large specific strength.

The connecting rod placed under such a condition has, for example, as disclosed in Japanese Patent Laid-Open No. 129306/1990, split into two pairs in a shape in which the surface is substantially perpendicular to the axis of the crankshaft hole. The body is powder-molded with a metal powder for sintering, and on the dividing surface of the divided body, a continuous groove is formed from the crankshaft hole to the piston pin hole, and the divided surfaces abut against each other,
After arranging a brazing material in the groove, there is a method in which both divided bodies are sintered in an abutting state and both divided bodies are brazed simultaneously with the sintering.

[0005]

In such a conventional connecting rod, the concave groove can be used as an oil supply passage, so that the connecting rod can be manufactured more easily than before, but a large force acts on the rotation of the engine. Then, the brazing material may be crushed and the oil supply passage may be blocked.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a connecting rod having even greater strength and which can be easily manufactured.

[0007]

In order to achieve this object, the invention according to claim 1 is made of a sintered metal and is divided into a pair of split parts in a plane substantially along the axis of the connecting rod. A body, in which at least one of the divided bodies is formed with a concave groove extending substantially along the axis of the connecting rod, and the pipe material is fitted into the concave groove of the divided body and both divided The pipe members are held by abutting the divided surfaces of the body against each other and forging them, and at least a part of the oil supply passage that connects the inner surface of the large end portion and the inner surface of the small end portion is formed by the pipe material. It is a connecting rod characterized by having been made.

According to the second aspect of the present invention, there is provided a pair of split bodies, each of which has a shape obtained by splitting into two parts along a plane substantially along the axis of the connecting rod, and at least one split body has a split surface of the connecting rod. Each of the grooves formed along the axis is formed of sintered metal, and a pipe material filled with powder is fitted into the grooves of the divided bodies so that the divided surfaces of both divided bodies collide with each other. Mold forging in a combined state to integrally join the pair of divided bodies and the pipe material, and open both end portions of the pipe material so as to be continuous with the inner surface of the large end portion or the small end portion, The connecting is characterized in that the powder is discharged to the outside from these openings, and the inside of the pipe material is made at least a part of an oil supply passage communicating between the inner surface of the large end and the inner surface of the small end. Made of rod It is a method.

[0009]

According to the invention described in claim 1 or 2, the above-mentioned divided bodies are made of sintered metal, and these divided bodies and the pipe material are forged and integrated into one body. At the same time, the body becomes a sintered forged product, and a connecting rod having even greater strength can be obtained.

Further, as described in claim 2, by using the pipe material filled with the powder, the deformation of the pipe material is reduced despite the action of the forging pressure. The deep hole can be formed relatively easily, and the connecting rod can be easily manufactured.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments shown in the drawings will be described below. First, regarding the first embodiment shown in FIGS. 1 to 7, for convenience of explanation, the connecting rod will be mainly described with reference to the manufacturing method of the connecting rod. The structure of the rod will also be described.

In FIG. 4, 1 is a divided body. The divided body 1 is manufactured by powder metallurgy in advance into a shape divided into two along a plane A-A along the axis O-O of the connecting rod 2 (see FIGS. 2 and 3) and is made of so-called sintered metal. is there.

A groove 4 is formed on the dividing surface 3 of the divided body 1 so as to extend along the axis O--O of the connecting rod 2.

In this embodiment, by connecting the divided surfaces 3 of the two divided bodies 1 formed in the same shape in a state of abutting each other, the external shape of the connecting rod 2 having a required shape is obtained. Obtainable.

When manufacturing the connecting rod 2 using such a split body 1, the cores 5a, 5b, 5c, 5d are filled so that the space around the split body 1 is closed and filled.
Is installed. This is to prevent the divided body 1 from being deformed in the subsequent forging step. The cores 5a, 5b, 5c, 5d used in this way are, for example,
It is preferable to use a sintered material having good machinability.

The cores 5a, 5b, 5 are thus
A pipe material 6 is arranged in the concave groove 4 of the divided body 1 in which c and 5d are mounted.

The pipe material 6 in this embodiment is filled with powder P such as sand, and the both ends are sealed (see FIGS. 6 and 7). The pipe material 6 is used to prevent the cross-sectional shape of the pipe material 6 from being deformed by a large forging pressure acting on the divided body 1 in the subsequent forging step.

Then, another divided body 1 is arranged from the upper side of the divided body 1 such that the divided surface 3 faces downward, and the divided surfaces 3 of the upper and lower divided bodies 1 abut each other,
The pipe member 6 is sandwiched between these divided bodies 1 (see FIG. 5).

The pair of upper and lower split bodies 1 in such a state is then set in a forging machine and a forging pressure is applied as indicated by an arrow in FIG. When forged in this manner, the divided body 1 is naturally in a state of being heated to a required temperature suitable for forging.

Therefore, the upper and lower split bodies 1 and the pipe material 6 in the above-described state are pressed against each other by a large forging pressure at a required temperature in the forging step, and thus are joined to each other to form the upper and lower split bodies 1. Pipe material 6 on the abutting surface of
It will be forged into an integrated state with the sandwiched.

In such a forging step, a large forging pressure acts on the sintered metal split body 1, so that the split body 1 becomes a so-called sintered forging material and has a higher specific strength than simple sintered metal. Will be things.

After the forging process is completed in this way, the cores 5a, 5b, 5c, 5d mounted on the split body 1 are mechanically removed by, for example, knocking down, etc. to obtain a connecting rod intermediate product. The intermediate product of such a connecting rod is machined as required and a predetermined bearing 7 is attached thereto to obtain the connecting rod 2.

In the machining after the forging process, as shown by the phantom line in FIG. 1, the axis O- of the connecting rod 2 is extended from the small end side and the large end side of the connecting rod 2.
Each end of the pipe member 6 is drilled along the O with a drill D or the like.

Thus, the powder P enclosed in the pipe material 6 can be easily discharged to the outside, and a deep through hole on the inner surface side of the pipe material 6 appears.

In the connecting rod 2 thus formed, the large end inner surface L and the small end inner surface S are formed.
The large-end inner surface L and the small-end inner surface S are linearly communicated with each other by the respective drill holes 8 and the through-holes 9 on the inner surface of the pipe member 6, and these are connected to the large-end inner surface. L
Side, it functions as an oil supply passage 10 for supplying piston cooling oil from the small end portion inner surface S side.

Next, a second embodiment shown in FIGS. 8 and 9 will be described.

The second embodiment is different from the first embodiment in the shape of the split body 11 for forming the connecting rod 2, and is otherwise substantially the same.

That is, the divided body 11 of the second embodiment.
When the connecting rod 2 having the same shape as that of the first embodiment is formed, a surface intersecting the AA line at a right angle is defined as a dividing surface 3 as shown by the BB line in FIGS. 2 and 3. It is a thing.

Even with the divided body 11 having such a shape,
A connecting rod 2 is formed by using a pipe material 6 in a manner substantially similar to that of the first embodiment by applying a forging pressure in a direction perpendicular to the dividing surface 3 as shown by an arrow in FIG. Can be easily manufactured, the oil supply passage 10 of the connecting rod 2 can be easily formed,
At the same time, the divided body 1 becomes a sintered forging material, so that the strength is also good.

Next, a third embodiment shown in FIG. 10 will be described.

In the third embodiment, the division surface 3 of the division body 12 is used.
The direction of is the same as that of the second embodiment, except that no through hole is formed in the large end and the small end.

In the case of manufacturing the connecting rod 2 using such a divided body 12, after the forging step, through holes are formed in each of the portions by machining so that the large end inner surface L and the small end inner surface S are formed. And will be formed.

At this time, both ends of the pipe member 6 extend into the regions where the through holes on the large end side and the small end side are to be formed (the inside of the large end inner surface L and the small end inner surface S). Since the respective end portions of the pipe material 6 are simultaneously removed by the machining, the powder P in the pipe material 6 is discharged to the outside without special processing. There is an advantage that is possible.

[0034]

As described above, claim 1 or 2
According to the invention described above, the divided body is made of a sintered metal, and these divided body and pipe material are forged and integrated into one body, and the divided body simultaneously becomes a sintered forged product. It is possible to obtain a connecting rod having even greater strength.

Further, as described in claim 2, by using the pipe material filled with the powder, the deformation of the pipe material is reduced despite the action of the forging pressure. The deep hole can be formed relatively easily, and the connecting rod can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a connecting rod according to a first embodiment.

FIG. 2 is a cross-sectional view of the connecting rod of the first embodiment.

FIG. 3 is a view on arrow M of FIG.

FIG. 4 is a plan view showing an installed state of a core in the first embodiment.

5 is a cross-sectional view taken along the line NN of FIG.

FIG. 6 is a side view in which a pipe member is partially broken.

FIG. 7 is a central sectional view of a pipe material.

FIG. 8 is a top view of a divided body according to a second embodiment.

FIG. 9 is a cross-sectional view showing an abutting state of the divided bodies of the second embodiment.

FIG. 10 is a sectional view of a third embodiment.

[Explanation of symbols]

 P powder L inner surface of large end S inner surface of small end O axis 1, 11, 12 split body 2 connecting rod 4 recessed groove 6 pipe material 8 drill hole 10 through hole

Claims (2)

[Claims] 1. A pair of divided bodies made of a sintered metal and divided into two substantially along a plane along the axis of the connecting rod, wherein at least one of the divided bodies has a division plane substantially along the axis of the connecting rod. A pipe material having a groove extending along the groove, the pipe material is fitted into the groove of the divided body, and the divided surfaces of both divided bodies are abutted against each other for forging to hold the pipe material. A connecting rod characterized in that at least a part of an oil supply passage communicating between the inner surface of the large end portion and the inner surface of the small end portion is formed by the pipe material. 2. A pair of split bodies, each of which has a shape obtained by splitting into two parts along a surface substantially along the axis of the connecting rod, wherein at least one split surface has a recess extending substantially along the axis of the connecting rod. Each of the grooves is formed of sintered metal, the pipe material filled with powder is fitted into the concave groove of the divided body, and die forging is performed with the divided surfaces of both divided bodies abutting each other. By doing so, the pair of divided bodies and the pipe material are integrally joined, and both ends of the pipe material are opened so as to be continuous with the inner surface of the large end portion or the small end portion, respectively, and the powder is discharged from these openings. A method for manufacturing a connecting rod, characterized in that the inside of the pipe material is discharged to the outside to form at least a part of an oil supply passage communicating between the inner surface of the large end portion and the inner surface of the small end portion.