KR20100010948U - Cam lobe for assemble type cam shaft - Google Patents

Abstract

The present invention improves the structure of the cam lobe for the camshaft to minimize the weight of the parts, to cope with the weight reduction trend throughout the engine parts for the internal combustion engine, as well as to further lighten the components driven by the rotational force, such as the camshaft, The cam lobe of the present invention is a cam lobe for improving the fuel efficiency of the camshaft and acceleration performance, and to reduce the driving torque such as friction loss and moment of inertia and to increase the rotational force. The shaft hole is formed to be assembled to, and both sides of the cam lobe is characterized in that formed by further forming a recessed portion inward for weight reduction.

In addition, the present invention is characterized in that the weight is reduced to the maximum by further opening to the lower end in a state in which both sides of the cam lobe formed in the main portion to lose weight.

Cam Shaft, Cam Lobe, Shaft, Lightweight, Prefabricated

Description

CAM LOBE FOR ASSEMBLE TYPE CAM SHAFT}

The present invention relates to a cam lobe for a prefabricated camshaft, and more particularly, to reduce the weight of the cam lobe by losing weight on both ends of the cam lobe inward, and to further reduce the camshaft parts, thereby reducing the fuel efficiency of the engine. The present invention relates to a cam lobe capable of improving and accelerating performance, reducing driving torque such as friction loss and moment of inertia, and increasing rotational force.

In general, a cam shaft is provided with a plurality of cam lobes and sensor pieces having different phases at predetermined intervals on a shaft outer circumference having a predetermined length and thickness, and the engine is driven as the cam shaft is rotated. will be.

The cam shaft absorbs the rotation of the shaft by arranging the cam on the shaft axis. In order to open and close the exhaust valve sequentially, a conventional manufacturing method includes an integral type formed integrally by casting a shaft and a cam by alloy cast iron, and a hollow prefabricated type in which a cam lobe is coupled to a hollow shaft made of a drawn steel pipe.

Various methods of manufacturing such a conventional cam shaft have been introduced. As an example, there is a method of integrally molding a shaft and a cam as a casting, that is, a cam shaft in which a casting is poured into a mold to form the shaft and a cam integrally. However, a conventional casting method is difficult to automate due to the characteristics of a work process. It is difficult and productive, and the heat treatment process must be performed for surface modification, which makes the work process cumbersome and the use of materials increases due to post-processing, resulting in waste of materials more than necessary. In addition, the heavy weight as a casting material has a limit in responding to the trend toward lighter weight throughout the engine parts, there were a number of disadvantages such as lower fuel efficiency of the engine for internal combustion engines.

In order to solve the problems of the conventional cam shaft made of the cast material, a more advanced and developed is a hollow prefabricated cam shaft manufacturing method of separately assembling the hollow shaft made of the drawing pipe and the cam lobe.

The hollow prefabricated camshaft can significantly reduce its weight compared to the integral camshaft, and can be assembled by assembling various assembly pieces such as cams, journals, sensors, and driving gears with different materials according to their functions and needs. This is a camshaft used in a vehicle that pursues compactness and light weight.

This is a method of tightly joining the shaft to the cam lobe by heat treatment by inserting the cam into the shaft, which has various advantages such as light weight, high performance, high efficiency, and process improvement. The trend is turning to shafts.

The prefabricated camshaft can be lightened through the hollowing of the shaft, but there is a limitation in unconditionally reducing the thickness of the shaft to secure the rigidity of the shaft, and thus, there is a limit to the further lightening of the camshaft through the lightweighting of the shaft alone.

In order to further reduce the weight of the camshaft, it is necessary to reduce the size of the product by changing the shape and shape of the product, and it is urgent to improve such as the need to use a lightweight material, but to improve the engine performance and the durability of the camshaft parts. There are many constraints to secure it.

On the other hand, looking at the conventional cam lobe 10 structure, as shown in Figure 1 cam lobe 10 has a shaft hole 11 is formed to be assembled to the shaft 20, one end is centered around the shaft hole (11) It is further protruded and eccentric, and the sliding surface 13 is formed around it.

And both sides 12 are made horizontal.

The cam lobe 10 is assembled to the cam shaft and installed on the head of the internal combustion engine as described above, and serves to open and close the intake and exhaust valves of the cylinder through reciprocating rotational motion. This actual driving of the cam lobe 10 becomes the surface of the sliding surface 13.

That is, other parts of the cam lobe 10 other than the sliding surface 13 do not have any contact when the engine is driven and do not function at all.

The present invention is to solve the above problems, has the following objectives.

The object of the present invention is to improve the structure of the cam lobe assembled and operated on the cam shaft to minimize the weight of the cam lobe and to further reduce the cam shaft components, thereby reducing the driving torque such as friction loss and moment of inertia. It is an object of the present invention to provide a camlobe of a new structure that can increase rotational force.

Still another object of the present invention is to provide a cam lobe that can be lightened by providing a lightweight cam lobe and assemble to the shaft to maximize the weight reduction of the assembled cam shaft, thereby improving fuel efficiency and acceleration performance of an engine for an internal combustion engine.

In the cam lobe of the present invention for achieving the above object, the shaft hole is formed to be assembled to the shaft, both sides of the shaft hole in the prefabricated cam shaft cam lobe made to be eccentric to one side around the shaft hole ,

The above object is achieved by further reducing the weight of the cam lobe by forming inwardly recessed recesses on both sides of the cam lobe.

The present invention achieves the above object by forming the cam lobe further inwardly by forming a recessed recessed portion on both sides and opening the side by weight.

As described, the present invention reduces the cam lobe to the maximum weight by additionally inwardly extruding both end portions and one end of the cam lobe, thereby further reducing the driving torque such as friction loss and moment of inertia. It is obvious that this is a very useful design such as to reduce the effect and increase the rotational force.

In addition, the present invention has a lightweight cam lobe to maximize the weight of the prefabricated camshaft, has the effect of improving the fuel efficiency and acceleration performance of the engine for the internal combustion engine.

In the following, embodiments of the present invention are described with reference to the accompanying drawings.

In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, the terms to be described later are terms set in consideration of functions in the present invention, and these terms may vary depending on the intention or custom of the producer producing the product, and the definition of the terms should be made based on the contents throughout the present specification.

The cam lobe of the present invention is formed by molding and sintering a metal alloy powder material. Such a assembled camshaft can realize a weight reduction of 30 to 50% or more than an integral cam shaft of a cast or forged product.

This lightweight product maximizes the weight of the engine for an internal combustion engine, and has the effect of improving fuel efficiency and acceleration performance.

(First embodiment)

The present invention is described below with reference to the accompanying drawings.

Figure 2 is a perspective view for explaining the structure of the cam lobe according to the first embodiment of the present invention, Figure 3 is a cross-sectional view of Figure 2, the cam lobe 10 of the present invention shaft hole 11 to be assembled to the cam shaft It has a side portion 12 is made horizontally around the shaft hole 11 and the sliding portion 13 is eccentrically centered on the shaft hole (11).

And both sides 12 of the cam lobe 10 is formed with a weight (14) inward.

At this time, by forming the recessed portion 14 to be recessed inwardly, the weight is reduced by approximately 7 to 10% as compared with the cam in which the recessed portion 14 is not formed.

On the other hand, in order to further reduce the weight can be further reduced by further forming a through hole around the recess 14, that is, the shaft hole (11).

And the main part is not to lose weight at right angles, it is preferable to lose weight obliquely.

Treatment at right angles increases mold setting time, increases mold wear, and reduces productivity in order to obtain a molded product of uniform quality during molding of the metal powder.

Round processing, on the other hand, ensures uniform product quality, minimizes mold setting time, reduces mold wear and improves productivity.

Since the cam lobe 10 of the above-mentioned structure transmits a load around the sliding part 13, it is preferable to use this cam lobe for the roller type counterpart.

(Second embodiment)

Figure 4 is a perspective view for explaining the structure of the cam according to a second embodiment of the present invention, Figure 5 is a cross-sectional view of Figure 4, the cam lobe 10 of the present invention has a shaft hole 11 to be assembled into a cam shaft It has a side portion 12 is formed horizontally with respect to the shaft hole 11 and the sliding portion 13 is eccentrically centered on the shaft hole (11).

In addition, both side portions 12 of the cam lobe 10 are formed with recessed portions 14 that are inwardly weighted.

In addition, the opening portion 15 is formed by further losing weight in communication with the depressed portion 14.

At this time, if the indentation recessed portion 14 is formed in addition to the lower portion of the opening portion 15 is further formed, compared with the cam lobe having no recess 14 and the opening 15 is approximately 9 to 14% The weight is saved.

On the other hand, to further reduce the weight can be further reduced by further forming a through hole around the recess 14, that is, the shaft hole (11).

And the main part is not to lose weight at right angles, it is desirable to lose weight obliquely.

Treatment at right angles increases mold setting time, increases wear of the mold, and lowers productivity in order to obtain a molded product having a uniform quality during molding of the metal powder.

Round processing, on the other hand, ensures uniform product quality, minimizes mold setting time, reduces mold wear and improves productivity.

Such a cam lobe is preferably used for a direct tappet type counterpart because the load is concentrated on the opposite side (a protruding portion) of the opening.

As described above, the cam lobe having the recessed inward portion or the opening having the one end slung is reduced in weight. At this time, the cam lobe in which the weight is reduced is further lightened for the camshaft part, such as friction loss and moment of inertia. It can reduce the driving torque and increase the torque.

In addition, it is possible to maximize the weight reduction of the assembled camshaft, thereby improving the fuel efficiency and acceleration performance of the engine for the internal combustion engine.

Referring to the present invention configured as described in detail as follows.

6 to 7 are diagrams of a cam lobe coupled to a cam shaft according to an embodiment of the present invention, when the cam lobe 10 is assembled to the shaft 20. The cam lobe 10 which matched the shaft hole 11 of the furnace cam lobe 10 is lowered by a fixed distance and angle, and the shaft hole 11 of the cam 10 is assembled and fixed on the shaft 20.

When the assembly is completed as described above, the sintering and liquid phase sintering of the cam lobe 10 are induced through a high temperature sintering process and finally joined to the shaft through diffusion bonding with the shaft 20.

Embodiments of the present invention have been described above with reference to the accompanying drawings.

However, it is to be noted that the present invention is not particularly limited only to the above-described embodiments, and as necessary, various modifications and changes can be made by those skilled in the art within the spirit and spirit of the appended claims.

1 is a perspective view for explaining a conventional cam structure.

Figure 2 is a perspective view for explaining the structure of the cam according to the first embodiment of the present invention.

3 is a cross-sectional view of FIG.

Figure 4 is a perspective view for explaining the structure of the cam according to a second embodiment of the present invention.

5 is a cross-sectional view of FIG. 4.

6 and 7 are perspective views of the use state of the cam according to the first embodiment and the second embodiment.

* Description of the symbols for the main parts of the drawings *

10: cam

11: shaft

12: side

13: sliding part

14: main part

15: opening

20: shaft

Claims (4)

In the cam shaft assembly is formed in the cam shaft, both sides of the shaft hole is horizontal and eccentric to one side about the shaft hole in the assembled cam shaft cam lobe, The cam lobe is formed of powder metallurgy, cam cam lobe for the prefabricated camshaft, characterized in that both sides of the cam lobe formed indented inward to reduce the weight of the cam lobe. The method of claim 1, The main cam cam lobe, characterized in that the obliquely inclined inward fat. In the cam shaft assembly is formed in the cam shaft, both sides of the shaft hole is horizontal and eccentric to one side about the shaft hole in the assembled cam shaft cam lobe, The cam lobe is formed of powder metallurgy, and both sides of the cam lobe are cams for the prefabricated camshaft, characterized in that the cam lobes are further formed with weights inwardly inwardly and openings in one side in communication with the recesses. Robe. The method of claim 3, wherein The recess and cam opening cam lobe for the prefabricated camshaft, characterized in that obliquely inclined inward.

Images