JPH04327315A - Manufacture of connecting rod main body part - Google Patents

Abstract

PURPOSE:To manufacture the connecting rod main body part which generates no burr, and also, is free from rough surface on the surface, and is more excellent by strength of a connecting rod part and a small end part. CONSTITUTION:At the time of manufacturing the connecting rod main body part having a large end part on one end side of a connecting rod part, and also, having a small end part on the other end side, an extrusion die 11 having a tapered part 11a corresponding to a shoulder part shape of a large end part, and also, having a bearing part 11b continued to said tapered part 11a is used, and by executing extrusion in the wall thickness direction of the connecting rod main body, an extrusion billet 10 having a semicircular part 10a corresponding to a semicircular part of said small end part is subjected to extrusion by said extrusion die 11 in the direction being orthogonal to the extrusion direction of the extrusion stock concerned 10, by which the connecting rod main body having the large end part, the connecting rod part and the small end part is obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a connecting rod body used in manufacturing a connecting rod that connects a piston and a crankshaft of a reciprocating engine.

0002

BACKGROUND OF THE INVENTION In recent years, there has been a strong demand for improvements in the fuel efficiency and performance of automobiles, and one way to achieve this is to reduce the weight of automobile parts.

[0003] Among these, the application of titanium alloys and aluminum alloys to connecting rods for automobile reciprocating engines is being actively considered, and among them, aluminum powder alloy materials and aluminum alloy powders, which have high strength and high rigidity, are being actively studied. Composite materials with ceramic powder are attracting attention.

[0004] In applying these materials to connecting rods, poor forgeability has long been a problem, but recently some materials have been improved in forgeability,
By improving the preform shape, it has become possible to use common connecting rod forging processes such as rough forging, finish forging, and trimming.

[0005]

Problems to be Solved by the Invention However, the following problems that occur when the above-mentioned forging process is used and are specific to the above-mentioned materials still remain.

[0006] ■ It is not suitable as a processing method for expensive materials because it generates a large amount of burrs and the material yield is low. ■ Since the material is sensitive to notches, the surface of the burr part must be finished to a level higher than that of forged skin. If it is not there, it may become the starting point of destruction.

On the other hand, as shown in FIGS. 8A and 8B, a connecting rod body 51 has a large end 51b at one end of the connecting rod 51a and a small end 51c at the other end. When manufacturing by extrusion molding, the large end 51b
A bearing part 52 that has a tapered part 52a corresponding to the shape of the shoulder part 51d and is continuous with the tapered part 52a.
Using an extrusion molding die 52 having an extrusion molding die 52, an extrusion material (53) having a rectangular cross section is charged into a container 54, and forward extrusion is performed by pressing it in the right direction in the drawing with a punch (not shown), thereby forming a large end 51b. There is a method of forming the connecting rod part 51a and the small end part 51c extruded from the bearing part 52b, but since the small end part 51c is formed by the most extreme part of the extruded material, The problem was that extrusion defects were likely to occur, making it impossible to improve performance.

Furthermore, as shown in FIG. 9, by performing extrusion molding in the thickness direction of the connecting rod body 61, the connecting rod portion 61a, large end portion 61b, and small end portion 61c can be formed in one extrusion molding. However, in this case, the main stress generated in the connecting rod portion 51a is in a direction perpendicular to the extrusion flow of the material, so the problem is that the fatigue strength of the connecting rod portion 51a tends to be reduced. There are some issues, and the challenge is to resolve these issues.

[0009]

[Object of the Invention] The present invention has been made in view of the above-mentioned problems in the prior art, and it does not produce burrs unlike when manufacturing a connecting rod body by forging, and the surface texture is similar to that produced by forging. Since there is no rough surface that can become a starting point for fracture, and the extrusion flow of the material in the connecting rod section is parallel to the stress generated in the connecting rod section, the connecting rod section The connecting rod body has high fatigue strength, and even if it is extruded, no extrusion defects will occur at the leading edge of the small end, so the strength of the small end can be made sufficiently good. The purpose of this paper is to provide a method for manufacturing parts.

0010

[Means for Solving the Problems] A method of manufacturing a connecting rod body according to the present invention includes extrusion molding a connecting rod body having a large end on one end of a connecting rod and a small end on the other end. When manufacturing, an extrusion molding die having a tapered part corresponding to the shape of the shoulder of the large end and a bearing part continuous to the tapered part is used to extrude the connecting rod main body part in the thickness direction. By extruding an extruded material having a semicircular portion corresponding to the semicircular portion of the small end using the extrusion molding die in a direction perpendicular to the extrusion molding direction of the extruded material, the large end and the connecting rod are formed. In an embodiment, the extruded material is extruded in the thickness direction of the connecting rod main body to form a semicircular shape of the small end. In the same embodiment, the extruded material is made of aluminum. A method for manufacturing a connecting rod main body as described above, characterized in that it is an extrusion billet made by compressing and solidifying a mixed powder of alloy powder or aluminum alloy powder and ceramic powder at an extrusion ratio of 10 or more. The structure of the invention according to the above is a means for solving the above-mentioned conventional problems.

The method for manufacturing a connecting rod main body according to the present invention has the above-described configuration, and includes an extrusion process having a tapered part corresponding to the shape of the shoulder of the large end and a bearing part continuous with the tapered part. Using a molding die, extrude molding in the thickness direction of the connecting rod main body portion to obtain an extruded material having a semicircular portion corresponding to the semicircular portion of the small end portion in a direction perpendicular to the extrusion molding direction of the extruded material. Since the extrusion molding die is used to extrude the material in the extrusion molding die, the material flow of the extruded material is in the thickness direction before extrusion molding by the extrusion molding die. After extrusion molding using a molding die, the material flow in the connecting rod portion is in the axial direction perpendicular to the wall thickness direction.

Furthermore, the extruded material is extruded in the thickness direction of the connecting rod body to have a semicircular portion corresponding to the semicircular portion of the small end, and a rectangular portion corresponding to the large end. It is possible to use an extrusion billet, but it is also possible to use an extrusion billet, for example, by extrusion molding in the thickness direction of the connecting rod body to have a semicircular part corresponding to the semicircular part of the small end and a large end. It is possible to use an extrusion billet having a bifurcated portion for forming the large end in the corresponding portion.

Furthermore, when the extruded material is made by extruding and solidifying aluminum alloy powder (for example, quenched powder) or a mixed powder of aluminum alloy powder (for example, quenched powder) and ceramic powder, It is desirable that the extrusion ratio during extrusion molding be 10 or more.

The reason for this is that when the large end and the connecting rod are extruded using an extrusion molding die, the large end is not subjected to a very large forging process. It is desirable to set the extrusion ratio at the time of molding to 10 or more to impart sufficient strength in advance.

[0015]

Effects of the Invention Since the method for manufacturing a connecting rod body according to the present invention has the above-described structure, burrs are not generated unlike when manufacturing a connecting rod body by forging, and the surface skin is formed by forging. Because there is no rough surface that could become a starting point for fracture, the extrusion flow of the material in the connecting rod is parallel to the stress generated in the connecting rod. To become
The fatigue strength of the connecting rod portion is high, and even if it is extruded, there will be no extrusion defects at the tip of the small end, and the strength of the small end will be sufficiently excellent.

[0016]

[Embodiment] Figures 1 to 7 show examples of the present invention, and Figure 1 shows an extruded material 10 formed by extrusion molding in the direction of arrow A, which is the thickness direction of the connecting rod main body. A billet for extrusion molding has a semicircular part 10a corresponding to the semicircular part and a rectangular part 10b in the part corresponding to the large end. For extrusion molding in the direction of arrow A, which has a semicircular portion 10a corresponding to the semicircular portion of the small end, and a bifurcated portion 10c for forming the large end in the portion corresponding to the large end. This shows the case of billet.

These extruded materials 10 are compressed and solidified by extruding aluminum alloy powder (for example, quenched powder) or a mixed powder of aluminum alloy powder (for example, quenched powder) and ceramic powder at an extrusion ratio of 10 or more. This extruded material 10 is cut into pieces corresponding to the thickness of the connecting rod and used as extrusion billets for extrusion molding in the next step.

FIG. 5 shows an example of the shape of the connecting rod body manufactured in this example. It has a small end 1c.

FIG. 3 shows an extrusion molding die, and this extrusion molding die 11 has a tapered portion 11a corresponding to the shape of the shoulder portion 1d of the large end portion 1b, and a bearing continuous to the tapered portion 11a. It has a section 11b and is connected to a container 12 having an extruded material charging space 12a.

Then, the extruded material 10 shown in FIG. 1 or FIG. Pressure is applied.

As a result, plastic flow occurs in the extruded material 10, and the extruded material 10 follows the shape of the tapered portion 11a and is pushed out from the bearing portion 11b, and the connecting rod portion 11
a is gradually extruded to form a connecting rod body 1 having a predetermined length of a connecting rod 1a having a large end 1b at one end and a small end 1c at the other end, as shown in FIG. obtain.

In the next step, the connecting rod main body 1 manufactured in this manner is subjected to drilling at the large end and small end, and the connecting rod portion 1a as illustrated in FIGS. 6 and 7 is formed. A fleshy shape is given.

In this case, the shape shown in FIG. 7 can be formed by machining, and the shape shown in FIG. 6 can be further formed by forging such as closed forging.

On the other hand, for comparison, a rectangular extrusion billet that was not extruded in the thickness direction of the connecting rod body was extruded using a conventional extrusion die 52 shown in FIG. A connecting rod main body 51 of Comparative Example 1 was manufactured, which had a large end 51b at one end of the connecting rod 51a and a small end 51c at the other end.

Further, as a comparative example, as shown in FIG. 9, a large end 61 is formed on one end side of the connecting rod portion 61a by extrusion molding in the thickness direction of the connecting rod main body.
A connecting rod main body portion 61 of Comparative Example 2 having a small end portion 61c on the other end side and having a small end portion 61c was manufactured by one-time extrusion molding.

Next, the connecting rod body portion 1 according to the above embodiment and the connecting rod body portions 51 and 61 according to comparative examples 1 and 2
A fatigue test was conducted using a connecting rod as a specimen by tensile compression in the axial direction, and the number of times it took to break under a load of 2.5 to 3.0 tons was compared.

As a result, the connecting rod main body 1 of the embodiment of the present invention did not break up to 107 times even under a load of 3.0 tons, whereas the connecting rod main body 51 of the comparative example 1 did not break even under a load of 3.0 tons. was 2.6 tons and broke at the small end 51c after 6×105 cycles, and the connecting rod body 6 of Comparative Example 2
No. 1 broke at the connecting rod portion 61a after 5×10 6 cycles under a load of 2.8 tons.

[0028]

[Effects of the Invention] According to the method for manufacturing a connecting rod body according to the present invention, burrs are not generated as in the case where the connecting rod body is manufactured by forging, and the surface texture is much better than that produced by forging. In order to achieve good quality, there is no rough surface area that could become a starting point for fracture, and the extrusion flow of the material in the connecting rod portion is parallel to the stress generated in the connecting rod portion. The fatigue strength of the connecting rod part is high, and even if it is extruded, the extruded material must have a semicircular part that corresponds to the semicircular part of the small end, so the The leading edge part of the small end is free from extrusion defects unlike those produced by conventional extrusion molding, and this is a remarkable improvement in that it is possible to manufacture a connecting rod body with sufficiently high strength at the small end. This will bring about a positive effect.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a slope illustrating one shape of an extruded material.

FIG. 2 is an explanatory diagram of a slope illustrating another shape of the extruded material.

FIG. 3A is a horizontal cross-sectional view and FIG. 3B is a vertical cross-sectional view showing a state in which an extrusion material is loaded into an extrusion molding die.

4A and 4B are explanatory horizontal cross-sectional views and FIG. 4B are explanatory vertical cross-sectional views, respectively, showing the state after extrusion molding of an extrusion material using an extrusion molding die.

FIG. 5A is an explanatory plan view and FIG. 5B is an explanatory side view of a connecting rod main body manufactured in an example of the present invention.

FIG. 6 is an explanatory cross-sectional view showing an example of a hollow shape of a connecting rod portion.

FIG. 7 is an explanatory cross-sectional view showing another example of the hollow shape of the connecting rod portion.

FIG. 8A is a horizontal sectional view and FIG. 8B is a vertical sectional view of an extrusion molding die showing an example of a conventional method for manufacturing a connecting rod main body.

FIG. 9 is an explanatory diagram of a slope of a connecting rod body showing another example of a conventional method for manufacturing a connecting rod body.

[Explanation of symbols]

1 Connecting rod body 1a Connecting rod part 1b Big end 1c Small end 1d Large end shoulder 1e　Semicircular part at small end 10 Extruded material 10a　Semicircular part of extruded material 10b Rectangular part of extruded material 10c Bifurcated part of extruded material 11 Extrusion molding die 11a Taper part 11b Bearing part

Claims (4)

[Claims] 1. When manufacturing a connecting rod main body by extrusion molding, the connecting rod body has a large end on one end side and a small end on the other end side, a tapered part corresponding to the shape of the shoulder of the large end. and a bearing part continuous to the tapered part, by extrusion molding in the thickness direction of the connecting rod main body part to form a semicircular part corresponding to the semicircular part of the small end part. The connecting rod body is formed into a connecting rod body having a large end, a connecting rod, and a small end by extruding the extruded material with the extrusion molding die in a direction perpendicular to the extrusion molding direction of the extruded material. A method of manufacturing a connecting rod body. 2. The extruded material is extruded in the thickness direction of the connecting rod main body to have a semicircular portion corresponding to the semicircular portion of the small end, and a rectangular portion at a portion corresponding to the large end. The method for manufacturing a connecting rod body according to claim 1, wherein the connecting rod body is a billet for extrusion molding. 3. The extruded material is extruded in the thickness direction of the connecting rod main body to have a semicircular portion corresponding to the semicircular portion of the small end, and a portion for forming the large end in a portion corresponding to the large end. The method for manufacturing a connecting rod main body according to claim 1, wherein the connecting rod body is a billet for extrusion molding having a bifurcated portion. 4. The extrusion material is an extrusion billet obtained by compressing and solidifying aluminum alloy powder or a mixed powder of aluminum alloy powder and ceramic powder at an extrusion ratio of 10 or more. A method for manufacturing the connecting rod body.