KR20150005777A - Cam shaft apparatus and its manufacturing method - Google Patents

Abstract

The present invention relates to a cam shaft capable of producing a super lightweight and high tensile product by integrally forging an aluminum shaft part and an aluminum lobe part of the cam shaft, and to a method for manufacturing the cam shaft. The cam shaft comprises: a forged shaft part; and a lobe part forged on a part of the shaft part to be integrated with the shaft part.

Description

Technical Field [0001] The present invention relates to a cam shaft apparatus and a manufacturing method thereof,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camshaft device and a method of manufacturing a camshaft device, and more particularly, to a camshaft device and a camshaft device for forging a shaft portion and a lobe portion of an aluminum- And a manufacturing method of the camshaft device.

Generally, a camshaft device is a component that serves to open and close an intake valve and an exhaust valve in accordance with rotation of an internal combustion engine, and adjusts an opening and closing timing of an intake and exhaust valve of a shaft serving as a rotary shaft, A lobe, and a journal serving as a rotating stator.

Since the opening and closing timings of the valves and the lifts are different from each other even if the curvature of the camshaft lobe is slightly changed, the performance of the engine is influenced by the valve opening and closing timing. Therefore, the conventional lobes and shafts are mainly used for cast iron and cast steel Iron-based material.

In the case of casting, gray cast iron and spheroidized graphite cast iron are cast at first and then heat treatment such as high frequency and nitriding is applied to the lobe However, in recent years, centrifugal casting has been carried out in a hollow state in order to minimize weight and to minimize casting defects. However, in order to minimize the weight and defects in casting, However, it is less competitive in terms of weight reduction than the hollow method using powder.

Currently, most of the camshaft devices are made of hollow steel pipe, the process of making the powder lobes to be bonded during the powder sintering process, and the method of joining the journals through brazing are the most applied, and more than 30% However, even in the case of the hollow powder sintering type, weight reduction and manufacturing cost reduction are required for the downsizing of the engine and the variable valve timing (VVT) control of the engine.

In order to satisfy both the light weight and the manufacturing cost reduction based on these demands, research and development have been carried out to manufacture the iron rope material through the aluminum casting first through mold casting and die casting, There is a problem in that when the aluminum shaft is solidified, due to the difference in the thermal expansion coefficient between the aluminum shaft and the iron-based lobe due to lack of toughness that can withstand the cam shaft device due to the defect, There is a limit to the application of the thread.

It is an object of the present invention to solve the various problems including the above problems, and it is an object of the present invention to provide an integrated casting part and a lobe part by forging a billet of an aluminum alloy material, When the shaft is forged and the lobe is assembled, the lobe can be manufactured by casting, forging, powder sintering, or the like, which is a conventional iron material manufacturing method, The aluminum alloy is manufactured by extrusion of an over-process Al-Si alloy and an aluminum composite material. The shaft and the lobe can be joined by using a polygonal body portion which can be coupled with each other. In the camshaft device, Since all of them are solid, the difference in shrinkage ratio It can be press-fitted and bonded without using, as its object to provide a manufacturing apparatus of the camshaft and the camshaft apparatus way while ensuring an excellent durability of the shaft to produce a lightweight and economically. However, these problems are exemplary and do not limit the scope of the present invention.

According to an aspect of the present invention, there is provided a camshaft device including: a shaft portion forging; And a lobe portion formed integrally with the shaft portion in a part of the shaft portion.

Further, the camshaft device and the camshaft device according to the present invention may further include a journal portion formed at a portion of the shaft portion.

Further, according to the idea of the present invention, the shaft portion and the lobe portion may include an aluminum component.

According to another aspect of the present invention, there is provided a method of manufacturing a camshaft device, comprising: preparing a billet including an aluminum component; Forging the billet into an integral shaft portion and a lobe portion using a forging die; And finishing the surface of the forged shaft portion and the lobe portion.

According to another aspect of the present invention, there is provided a camshaft device including a shaft portion forgingly formed and a shaft portion including a polygonal body portion integrally forged with the shaft portion on a part of the shaft portion, ; And a lobe having a polygonal hole portion corresponding to the polyhedron portion of the shaft and being assembled to the polyhedron portion.

According to an aspect of the present invention, the shaft may further include a journal portion formed at another portion of the shaft portion.

Further, according to the idea of the present invention, the shaft may comprise an aluminum component.

According to another aspect of the present invention, there is provided a method of manufacturing a camshaft device, comprising: preparing a billet including an aluminum component; Forging the billet into a shaft, which may include a shaft portion and a polygonal body portion formed integrally with the shaft portion at a portion of the shaft portion using a forging die; Assembling a lobe having a polygonal hole in the forged polygonal body; And finishing the shaft and the lobe.

According to some embodiments of the present invention as described above, it is possible to mass produce, improve productivity and economical efficiency, lighten product, produce high-quality products without internal defects, and assemble robustly So that the durability can be greatly improved. Of course, the scope of the present invention is not limited by these effects.

1 is a perspective view illustrating a camshaft apparatus according to some embodiments of the present invention.
FIGS. 2 to 3 are views showing steps of a method of manufacturing the camshaft device of FIG. 1. FIG.
4 is a flowchart showing a method of manufacturing a camshaft device according to some embodiments of the present invention.
5 is a part exploded perspective view showing a camshaft device according to some other embodiments of the present invention.
Fig. 6 is a perspective view showing the assembly of the camshaft device of Fig. 5;
Fig. 7 is a sectional view showing a VII-VII cross-sectional view of the camshaft device of Fig. 6;
8 to 9 are diagrams showing steps of a method of manufacturing the camshaft apparatus of Fig.
10 is a flowchart showing a method of manufacturing a camshaft device according to some other embodiments of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are described in order to more fully explain the present invention to those skilled in the art, and the following embodiments may be modified into various other forms, The present invention is not limited to the embodiment. Rather, these embodiments are provided so that this disclosure will be more thorough and complete, and will fully convey the concept of the invention to those skilled in the art. In the drawings, the thickness and size of each layer are exaggerated for convenience and clarity of explanation.

It is to be understood that throughout the specification, when an element such as a film, region or substrate is referred to as being "on", "connected to", "laminated" or "coupled to" another element, It will be appreciated that elements may be directly "on", "connected", "laminated" or "coupled" to another element, or there may be other elements intervening therebetween. On the other hand, when one element is referred to as being "directly on", "directly connected", or "directly coupled" to another element, it is interpreted that there are no other components intervening therebetween do. Like numbers refer to like elements. As used herein, the term "and / or" includes any and all combinations of one or more of the listed items.

Although the terms first, second, etc. are used herein to describe various elements, components, regions, layers and / or portions, these members, components, regions, layers and / It is obvious that no. These terms are only used to distinguish one member, component, region, layer or section from another region, layer or section. Thus, a first member, component, region, layer or section described below may refer to a second member, component, region, layer or section without departing from the teachings of the present invention.

Also, relative terms such as "top" or "above" and "under" or "below" can be used herein to describe the relationship of certain elements to other elements as illustrated in the Figures. Relative terms are intended to include different orientations of the device in addition to those depicted in the Figures. For example, in the figures the elements are turned over so that the elements depicted as being on the top surface of the other elements are oriented on the bottom surface of the other elements. Thus, the example "top" may include both "under" and "top" directions depending on the particular orientation of the figure. If the elements are oriented in different directions (rotated 90 degrees with respect to the other direction), the relative descriptions used herein can be interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise "and / or" comprising "when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.

Hereinafter, embodiments of the present invention will be described with reference to the drawings schematically showing ideal embodiments of the present invention. In the figures, for example, variations in the shape shown may be expected, depending on manufacturing techniques and / or tolerances. Accordingly, the embodiments of the present invention should not be construed as limited to the particular shapes of the regions shown herein, but should include, for example, changes in shape resulting from manufacturing.

In embodiments of the present invention, the camshaft device can be generally referred to as including a shaft, a lobe, and an engagement member. It should be understood, however, that the scope of the present invention is not limited only to the above terms in that in such a camshaft device the shaft may be referred to as a camshaft, and the lobe may also be referred to as a cam lobe or simply as a cam.

1 is a perspective view showing a camshaft apparatus 10 according to some embodiments of the present invention.

1, a camshaft device 10 according to some embodiments of the present invention includes a shaft portion 10-1, a lobe portion 10-2, And a journal unit 10-3.

Here, the shaft portion 10-1 can be forged by, for example, a metal mold.

Further, the lobe portion 10-2 can be forged, for example, integrally formed with the shaft portion 10-1 on a part of the shaft portion 10-1.

The journal portion 10-3 is formed integrally with a part of the shaft portion 10-1 with the shaft portion 10-1 and the lobe portion 10-2, It can be processed smoothly.

Here, the shaft portion 10-1, the lobe portion 10-2, and the journal portion 10-3 may include an aluminum component for weight reduction.

The shaft portion 10-1 may be, for example, a kind of rotation axis of the lobe portion 10-2 for opening and closing the intake valve and the exhaust valve of the engine. Of course, the shaft part 10-1 is not necessarily installed in the engine, and all the rotary shafts provided with the lobes widely used in various types of devices and equipments can be applied.

Although not shown, for example, the shaft portion 10-1 may be formed into a pipe shape that has been machined so that a hollow is formed in the longitudinal direction inside the shaft portion 10-1 after the forging, in order to make the product lighter and stronger. When the shaft portion 10-1 is formed into a pipe shape, the shearing force of one side surface of the shaft portion 10-1 can not pass through the center of the shortest distance by the hollow, Therefore, the weight of the hollow can be reduced, so that the weight of the product can be reduced, and at the same time, the strength can be further increased. The diameter of the hollow portion can be optimally designed according to the material characteristics of the shaft portion 10-1, the use environment, the processing characteristics, the specification characteristics, and the like. In Fig. 1, the hollow shaft-like shaft portion 10-1 is illustrated.

For example, the shaft portion 10-1 and the lobe portion 10-2 may be made of an aluminum material of 2,000 series, 4000 series, 5,000 series, 6000 series, 7000 series, , A magnesium alloy, a titanium alloy, or the like may be applied.

That is, the shaft portion 10-1, the lobe portion 10-2, and the journal portion 10-3 are made of a material such as the above-mentioned material Can be integrally formed by forging.

Figs. 2 to 3 are diagrams showing steps of a method of manufacturing the camshaft apparatus 10 of Fig. 1, and Fig. 4 is a flowchart showing a method of manufacturing the camshaft apparatus 10 according to some embodiments of the present invention .

2 to 4, a method of manufacturing a camshaft apparatus 10 according to some embodiments of the present invention includes: first, as shown in FIG. 2, a cylindrical- (1) can be prepared.

Here, the billet 1 may be an aluminum composite material of 2,000 series, 4000 series, 5,000 series, 6000 series, 7000 series, and may be a magnesium alloy, a titanium alloy, or the like.

In addition, the billet 1 may be aluminum extruded to make the tissue compact. Of course, the billet 1 may be manufactured by various methods such as casting, forging, extrusion, powder sintering, die casting and the like.

3, the billet 1 is fixed to the integral shaft portion 10-1, the lobe portion 10-2 and the journal portion 10-3 by using the forging molds M1 and M2. ). Here, the forging molds M1 and M2 may be a pair of upper and lower molds, and the entirety of the integral shaft portion 10-1, the lobe portion 10-2, and the entire journal portion 10-3 may be forged For example, an entire forging die to be formed, or a partially forged die capable of partially forging.

Next, though not shown, the forged shaft portion 10-1, the lobe portion 10-2, and the journal portion 10-3 can be surface-treated and finishing can be performed precisely.

Therefore, it is possible to simultaneously produce the shaft portion and the lobe portion by integral monolithic molding, thereby mass production is possible, the productivity and economy can be greatly improved, the product including the aluminum component can be lightened, It is possible to produce a good quality product without.

4 is a flowchart showing a method of manufacturing the camshaft apparatus 10 according to some embodiments of the present invention.

2 to 4, a method of manufacturing a camshaft apparatus 10 according to some embodiments of the present invention includes a step S11 of preparing a billet 1 containing an aluminum component, The step (S12) of forging the billet 1 with the integral shaft portion 10-1 and the lobe portion 10-2 using the mold M1 and M2 and the step S12 of forming the forged shaft portion 10-1 And a step S13 of finishing the surface of the lobe portion 10-2 and the lobe portion 10-2.

5 is a fragmentary exploded perspective view showing a camshaft apparatus 20 according to some other embodiments of the present invention, Fig. 6 is a perspective view of parts assembly of the camshaft apparatus 20 of Fig. 5, Sectional view taken along line VII-VII of the camshaft device 20;

5 to 7, a camshaft apparatus 20 according to some other embodiments of the present invention includes a shaft 21 and a rod 22 that is a separate component from the shaft 21 (lobe).

5, the shaft 21 includes, for example, a shaft portion 21-1 to be forged and a portion of the shaft portion 21-1. The shaft portion 21-1 And a polygonal section 21-2 integrally forged with the bottom plate 21-2.

For example, the shaft 21 may further include a journal portion 21-3 formed at another portion of the shaft portion 21-1. Further, the shaft 21 may include an aluminum component. That is, the shaft 21 may be made of an aluminum composite material of 2,000 series, 4000 series, 5,000 series, 6000 series, 7000 series, or may be a magnesium alloy, a titanium alloy, or the like.

5 and 6, the lobe 22 is formed with a polygonal hole portion 22a corresponding to the polygonal portion 21-2 of the shaft 21, And can be assembled to the portion 21-2.

The lobe 22 is a kind of mechanical element installed on the shaft 21 and capable of opening and closing various valves by using the bending of the surface of the lobe 22, Such as press fitting, brazing, MIG and TIG bonding, friction bonding, screw rotation, and the like.

The lobes 22 shown in Figs. 5 and 6 are provided to the four-cylinder engine as a double overhead cam shaft < RTI ID = 0.0 > One camshaft device applied to a double overhead camshaft engine is illustrated.

In addition, a journal (not shown) for supporting the shaft 21 can be formed between the lobes 22 provided on the shaft 21, respectively. For example, the journal portions 21-3 can cut the shaft 21 and mold the same.

Here, the lobe 22 may be made of an aluminum alloy material such as an Al-Si alloy and an Al composite material. However, the lobe 22 is not limited to the cast iron, cast iron, gray cast iron, chilled cast iron, or the like. The lobe 22 may be made of a cast steel such as carbon steel, aluminum steel or nitriding steel, A titanium alloy material made of a composite material or the like can be applied.

Further, the lobe 22 can be extrusion-molded using the above-described materials so that the structure is dense, the weight of the product is increased, and the productivity is increased. However, the lobe 22 may be manufactured by a method such as casting, powder sintering (in-situ synthesis), and the like.

The shaft 21 and the lobes 22 can further improve strength and durability through other surface coating or heat treatment.

5 and 6, the number of polygonal faces of the polygonal body portion 21-2 integrally forged with the shaft portion 21-1 is greater than the number of polygonal faces of the shaft 21- A plurality of cylinders may be conformally formed in consideration of the number of cylinders of the engine and the number of installed valves.

More specifically, when the engine is a three-cylinder type, the polyhedron 21-2 may be a hexahedron or a hexahedron so that a phase difference of 120 degrees can be realized. When the engine is a four-cylinder, The polyhedron 21-2 may be a tetragonal, octagonal, or hexagonal polyhedral body so as to be capable of being implemented.

Further, in the case where the engine is a five-cylinder engine, the polyhedron 21-2 may be a pentagonal or a hexahedron so that a phase difference of 72 degrees can be realized, and when the engine is a six- The polyhedron 21-2 may be a hexagonal or octagonal polyhedron. When the engine is an 8-cylinder, the polyhedron 21-2 may be a quadrangle Octahedron, octahedron, or octahedron. In addition, various types of polygonal shapes can be realized depending on the phase difference of the cylinder.

8 to 9 are views showing steps of a method of manufacturing the camshaft apparatus 20 of Fig.

8 to 9, a method of manufacturing a camshaft apparatus 20 according to some other embodiments of the present invention includes: first, as shown in FIG. 8, a cylindrical- The billet 2 can be prepared. Here, the billet 2 may be an aluminum material of 2,000 series, 4000 series, 5,000 series, 6000 series, 7000 series, or may be a magnesium alloy, a titanium alloy, or the like.

In addition, the billet 2 can be aluminum extruded to make the tissue compact. Of course, the billet 2 may be manufactured by various methods such as casting, forging, extrusion, powder sintering and die casting.

Next, as shown in FIGS. 5 and 9, the billet 2 is fixed to the shaft portion 21-1 and a part of the shaft portion 21-1 by using a forging die M3 (M4) It can be forged by a shaft 21 which may include a polygonal body portion 21-2 integrally formed with the shaft portion 21-1.

The forging molds M3 and M4 may be a pair of upper and lower molds or may be an entire forging die for integrally molding the integral shaft portion 21-1 and the polygonal body portion 21-3 at the same time, It may be a partially forged mold capable of partially forging molding.

Then, as shown in Fig. 6, a lobe 22 having a polygonal hole portion 22a formed in the polygonal cross-section 21-2 forging can be assembled.

The lobe 22 may be fixed to the shaft 21 by a method such as press fitting, brazing, MIG and TIG bonding, friction bonding, screw rotation, or the like.

Then, the assembled shaft 21 and the lobes 22 can be surface-treated and finished by a precision machining process.

Therefore, it is possible to simultaneously produce the shaft portion 21-1 and the polygonal sheave portion 21-2 of the shaft 21 by the integral forging molding, thereby mass production is possible, and the productivity and economy are greatly improved, The lob 22 can be manufactured separately and assembled to assemble the product 22 in accordance with the characteristics of the lobes 22 where the friction is concentrated. The durability can be further increased.

10 is a flowchart showing a method of manufacturing the camshaft apparatus 20 according to some other embodiments of the present invention.

5 to 10, a method of manufacturing a camshaft apparatus 20 according to some other embodiments of the present invention includes a step S21 of preparing a billet 2 containing an aluminum component, The billet 2 is inserted into the shaft portion 21-1 and a part of the shaft portion 21-1 by using the forged mold M3 M4, A step S22 of forging molding with a shaft 21 which may include a sheath portion 21-2 and a step 22 of forming a lobe 22 having a polygonal hole portion 22a in a forged polygonal body portion 21-2 (S23) of assembling and finishing the shaft (21) and the lobe (22) (S24).

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

1, 2: Billet
10, 20: Camshaft device
10-1: shaft portion
10-2:
10-3: Journal section
M1, M2, M3, M4: Forging mold
21: Shaft
21-1: shaft portion
21-2: polygonal section
22: Robe
22a:
21-3: Journal section

Claims (8)

A shaft portion to be forged; And
A lobe part formed integrally with the shaft part in a part of the shaft part;
And the camshaft device. The method according to claim 1,
A journal portion formed at a portion of the shaft portion;
Further comprising: The method according to claim 1,
Wherein the shaft portion and the lobe portion comprise an aluminum component. Preparing a billet comprising an aluminum component;
Forging the billet into an integral shaft portion and a lobe portion using a forging die; And
A step of finishing the surface of the forged shaft portion and the lobe portion;
Wherein the camshaft comprises a camshaft. A shaft which may include a shaft portion to be forged and a polygonal body portion formed integrally with the shaft portion at a portion of the shaft portion; And
A lobe having a polygonal hole portion corresponding to the polyhedron portion of the shaft and being assembled to the polyhedron portion;
And the camshaft device. 6. The method of claim 5,
Wherein the shaft includes: a journal portion formed at another portion of the shaft portion;
Further comprising: 6. The method of claim 5,
Wherein the shaft comprises an aluminum component. Preparing a billet comprising an aluminum component;
Forging the billet into a shaft, which may include a shaft portion and a polygonal body portion formed integrally with the shaft portion at a portion of the shaft portion using a forging die;
Assembling a lobe having a polygonal hole in the forged polygonal body; And
Finishing the shaft and the lobe;
Wherein the camshaft comprises a camshaft.

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