JPS5844890B2 - Engine connecting rod semi-finished products - Google Patents

Description

[Detailed description of the invention] This invention relates to engine connecting rods.

In particular, the present invention relates to a casting or forging material for a connecting rod whose large end is formed by a connecting rod main body and a bearing cap.

Conventionally, in order to assemble the engine connecting rod to the crankshaft, it is divided into two along the plane that passes through the crankpin axis.

It is commonly used to consist of a connecting rod main body and a bearing cap.

Therefore, when manufacturing them, there are two ways of thinking about the composition of the casting material.

The first method is to prepare the materials for the connecting rod main body and the bearing cap separately, and the second method is to cast or cast them as one piece and then cut them by machining.

However, the former requires more casting or molding processes, which inevitably increases costs, and the latter requires relatively inefficient cutting with metal saws or milling cutters, making it unsuitable for mass production and similarly increasing costs. I don't get any exemption.

The present invention aims to eliminate such problems.

The present invention will be explained below with reference to eight illustrated embodiments.

The drawing shows a cast stock of iron or light alloy of a connecting rod according to the invention.

This material A consists of a main body 1 of a connecting rod and a bearing cap 2, which are connected via a connecting extra wall 3 that is removed during processing.

The main body 1 has a small end B having a piston pin hole 4 at one end;
The other end has a semicircular recess 5 forming a part of the crankshaft hole, and the bearing cap 2 has a semicircular recess 2a forming the remainder of the crankshaft hole.

The main body 1 and the bearing cap 2 are connected to each other via an extra wall 3 with their recesses 2a and 5 facing each other.

The extra thickness 3 has notches 3a extending from both end surfaces of the connecting rod.
It is weakened to facilitate breaking and separation.

The bottom of the notch 3a is recessed in a triangular shape as shown in FIG. 4, and it is preferable to make the angle a as sharp as possible to enhance the notch effect, as long as it is allowed in manufacturing the mold.

In the figure, the circle 6 indicated by the two-dot chain line represents the main body 1 and the bearing cap 2.
This is a bolt (not shown) hole for connecting the two.

In the connecting rod product formed as described above, the main body 1 and the bearing cap 2 are integrally connected via the extra wall 3, so that it is easy to cast or forge.

The material can be manufactured all at once.

At this time, the cross-sectional area of the extra wall 3 is preferably large in order to improve the vortex flow during casting, but as will be described later,
This part will be broken in a later process.

It is preferable that it be as small as possible for casting or forging.

The material A thus formed is separated in the following manner prior to the machine ηloe.

Namely. Both end surfaces of the main body 1 are held in a vise or the like, and the bearing cap 2 is hit with a hammer or the like from the notch 3a side to the other side.

Then, stress is concentrated on the extra thickness 3 due to the notch 3a, and the extra thickness 3 is relatively easily broken.

Thereafter, the main body 1 and the bearing cap 2 are machined in a conventional manner.

That is, both end faces of the piston pin 1 and the piston pin hole 4 and the crank pin hole are roughly finished, a bolt hole 6 is drilled, and the two are connected with a bolt (not shown).

After that, each pin hole is precisely finished, and heat treatment and copper plating are applied as necessary.

In this example, cast iron is used as the material, which is broken immediately after casting and then subjected to strain relief annealing, but other materials, such as light alloys such as aluminum 1-cum alloy, may also be used. .

Further, the main body 1 and the bearing cap 2 may be separated by breaking after the bolt holes 6 are drilled, and in this case, the excess thickness 3 is further reduced and the breaking becomes easier.

The connecting rod semi-finished product of the present invention includes a connecting rod main body having a recess forming a part of the crank pin pin hole at one end, and a bearing cap having a recess forming the remainder of the crank pin pin hole, as described above. And.

Since the connecting rod body and the bearing cap are connected through the connecting extra wall and a notch is provided in the connecting extra wall, the connecting rod main body and the bearing cap are formed at the same time during casting or forging. The process is shortened.

In addition, to separate them, a simple process of fixing one of the main body and the bearing cap and pounding the other is sufficient, and there is no need to use a milling machine or saw that requires high machining costs per unit time. .

Production costs can be significantly reduced.

Since the notch is provided roughly in the excess thickness, the excess thickness becomes brittle and has the effect of allowing the main body and the bearing cap to be separated even by a relatively weak blow.

In the embodiment, the notches 3a are provided on both end surfaces of the continuous bar, and the depth of the notches 3a is made shallow to narrow the width and reduce the excess thickness, but it is also possible to provide them only on one side. good.

Furthermore, although the bottom surface of the notch is triangular to enhance the notch effect, it is needless to say that the shape is not limited to this.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a front view of a semi-finished continuous bar product, and FIG. 2 is a longitudinal sectional view thereof. Figure 3 is a simplified diagram of lI [-I, Figure 4 is a reference numeral 14 in Figure 2.
FIG. 2 is an enlarged view of the main parts shown in FIG. A...Material, 1...Subject, 2...
・・Bearing cap. 3...Excess meat, 3a...Notch.

Claims (1)

[Scope of Claims] 1. A main body of a connecting rod having a recess forming a part of the crank pin hole at one end, and a bearing cap having a recess forming the remainder of the crank pin hole for connection. As well as being connected through extra meat. A semi-finished product of a continuous rod for an engine, in which a notch is provided in the excess thickness for connection.