JPH0242917Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention consists of a cam lobe separately manufactured on the shaft,
This relates to an assembled camshaft made by assembling and integrating component parts such as journals, and particularly relates to an assembled camshaft in which the main part is made of steel and the other parts are made of liquid phase sintered alloy. be.

Traditionally, camshafts are generally cast to have a solid, integral structure, but they are very heavy, so in recent years, to reduce the weight of engines, metal cam lobes, journals, and other components have been assembled onto a hollow steel stem. is increasingly being used. However, even further weight reduction is required.

Furthermore, for the components of the assembled camshaft, liquid phase sintered alloys can be used in terms of wear resistance, lubricity, and ease of assembly to the shaft. However, liquid phase sintered alloys are hard and have poor workability, which poses problems in mass production.
Therefore, as shown in Fig. 1, the component 2 assembled to the shaft 1 consists of a steel member 3 on the outer periphery and a liquid phase sintered alloy member 4 on the inner periphery. There is a method of integrally bonding the three members 4 by diffusion bonding. Note that the axial length of the component is shown. In this conventional product, since the liquid phase sintered alloy, which is hard and has poor workability, is present on the inner peripheral side, it is difficult to provide oil holes and the like in the component parts. In addition, in order to improve lubricity, there is a method of providing oil holes etc. in advance in both the steel member 3 and the liquid phase sintered alloy member 4, but this method is easy to process, but it is difficult to make oil holes in both oil holes and the oil hole in the shaft. It is necessary to perform positioning.

The present invention takes the above points into consideration and provides an assembled camshaft that is lightweight and has excellent workability, eliminates difficulty in positioning, and has excellent lubricity.

In other words, in an assembled camshaft in which component parts such as cam lobes and journals that are separately manufactured are assembled and integrated with the shaft, the component parts are made of steel that is divided into two parts at the axial center and fitted to the shaft with a space between them. The shaft, the steel member, and the liquid phase sintered alloy member are fitted into the part adjacent to the shaft between the two divided steel members, and the shaft, the steel member, and the liquid phase sintered alloy member are bonded together by diffusion bonding. This is an assembled camshaft characterized by being integrally connected.

The present invention will be explained below with reference to the accompanying drawings.

FIG. 2 shows an embodiment of the assembled camshaft of the present invention.

A steel member that fits on the shaft is divided into two parts 3, 3 at the center, and grooves 31, 31 are provided in the part of the divided surface adjacent to the shaft, and liquid phase sintering is performed between them. The metal member 4 is fitted in contact with the shaft.

As a result, a dividing groove 5 is formed between the steel members 3 and 3'.

In this case, the steel members 3, 3' and the dividing groove 5
The sum of the axial lengths of the components is equal to the axial length of the conventional component shown in FIG. Since the groove 5 is formed, the assembled camshaft of the present invention is lighter than the conventional product.

Also, when providing oil holes in component parts, since the annular groove is formed in the center, the number of machining operations is extremely small, as only the through holes are formed in the liquid phase sintered alloy member during powder compaction. I'm done.

The oil hole penetrates the outer peripheral surface of the liquid phase sintered alloy member and the inner peripheral surface of the shaft. Reference numeral 6 indicates an oil hole provided in the liquid phase sintered alloy member, and 7 indicates an oil hole drilled in the shaft 1, and these positions can be easily performed since the thickness of the liquid phase sintered alloy member 4 is small. Can be done.

In the assembled camshaft of the present invention, the component 2 is coupled to the shaft 1 by integrally coupling the shaft 1 and the liquid phase sintered alloy member 4 and the liquid phase sintered alloy member 4 and the steel members 3 and 3' by diffusion bonding.

FIG. 3 shows another embodiment of the present invention, in which grooves are provided at right angles at positions slightly away from the shaft on both sides of the dividing groove 5, and an annular protrusion on the outer peripheral end of the liquid phase sintered alloy member 4 is formed therein. 41 is fitted.

As a result, the shaft 1, steel members 3, 3'
The three members of the liquid phase sintered alloy member 4 are bonded together better.

The components of this invention have such a configuration and can be made lighter due to the presence of the dividing grooves, and when oil holes are provided in advance before assembling the liquid phase sintered alloy member to the shaft, the oil holes should be spaced from each other. Positioning can be easily performed, and on the other hand, even when drilling oil holes after joining the member to the shaft, it can be done with a small amount of work. It is possible to provide oil holes in the liquid phase sintered alloy part with a small number of machining operations.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a conventional camshaft, FIG. 2 is a vertical sectional view showing one embodiment of the camshaft of this invention, and FIG. 3 is a sectional view showing another embodiment. Explanation of symbols, 1... Shaft, 2... Components, 3
... Steel member, 4... Liquid phase sintered alloy member, 5... Division groove, 6, 7... Oil hole, 31... Groove, 41... Annular protrusion of liquid phase sintered alloy member.

Claims (1)

[Scope of utility model registration request] In an assembled camshaft in which component parts such as cam lobes and journals that are separately manufactured are assembled and integrated with the shaft, the component parts are divided into two parts at the center in the axial direction, and a steel member and a steel member are fitted to the shaft with a space between them. , a liquid-phase sintered alloy member is fitted into the part adjacent to the shaft between two divided steel members, and the shaft, steel member, and liquid-phase sintered alloy member are integrally joined by diffusion bonding. An assembled camshaft characterized in that an oil hole is provided which penetrates the outer peripheral surface of the liquid phase sintered alloy member and the inner peripheral surface of the shaft.