JP2011074830A - Camshaft and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camshaft and a method for manufacturing the same, reducing manufacturing costs using a projection produced when each shaft member is joined by friction welding for the other purpose. <P>SOLUTION: Both the axial sides of the projection 3 produced over a peripheral direction on the peripheral portion of a connection between a shaft body 1 and an end piece 2 by a friction welding method is machined into a plane surface, thereby forming a disk-shaped flange 3a. The flange 3a is used for other purpose. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a camshaft formed by joining a plurality of members in the axial direction by a friction welding method and a method for manufacturing the camshaft.

  Conventionally, as this type of camshaft, for example, when a partially suitable member such as wear resistance and toughness is different, or when it is difficult to process from one member, a plurality of shaft members are obtained by friction welding. A device that is integrally formed by joining in the axial direction is known (for example, see Patent Document 1).

JP 2006-241980 A

  Since each shaft member is joined by the friction welding method in the camshaft, a projecting portion is formed in the circumferential direction by a member projecting radially outward at a joint portion with an adjacent shaft member. In the camshaft, the projecting portion is not used, and the camshaft is used with the projecting portion remaining, or the projecting portion is scraped and used as unnecessary. In the case where the projecting portion is scraped off from the camshaft, the number of processing steps increases, and thus the manufacturing cost increases.

  The camshaft includes a shaft portion having a predetermined outer diameter and a cam portion formed to have a larger outer diameter than the shaft portion. In addition to the cam portion, the camshaft is associated with other members located in the vicinity. The outer surface of the shaft, such as a thrust flange for restricting axial movement by combining them, or a signal rotor provided for detecting the rotation angle of the camshaft and having a groove that can be detected by the cam angle sensor, etc. It has a part formed larger than the diameter dimension. The portion formed larger than the outer diameter of the shaft portion needs to be formed by cutting or the like, or attached as a separate part. Therefore, the number of processing steps or assembly steps increases, and the manufacturing cost increases.

  An object of the present invention is to provide a camshaft and a camshaft manufacturing method capable of reducing the manufacturing cost by utilizing a protrusion generated when joining each shaft member by friction welding as another application. It is to provide.

  In order to achieve the above object, the present invention provides a camshaft formed by joining a plurality of shaft members in the axial direction by a friction welding method, and adjacent shafts when the shaft members are joined by a friction welding method. The disk-shaped flange part is provided by forming the both sides of the axial direction of the protrusion part which arises over the circumferential direction in the outer peripheral part of the junction part with a member in planar shape.

  A method of manufacturing a camshaft formed by joining a plurality of shaft members in the axial direction by a friction welding method and having a disc-shaped flange portion on an outer peripheral portion of a predetermined axial direction, wherein each shaft member is The flange portion is formed by processing both ends in the axial direction of the projecting portion generated in the circumferential direction on the outer peripheral portion of the joint portion with the adjacent shaft member when joining by the friction welding method.

  Thereby, since the disk-shaped flange part is provided by forming the axial direction both sides of a protrusion part in planar shape, a protrusion part can be utilized for another use.

  According to the present invention, since the protrusions that have not been used or have been cut off can be used for other purposes by simple processing, a member is separately attached or a shaft member is processed for other purposes. It is not necessary to reduce the manufacturing cost.

It is a side view of the camshaft which shows one Embodiment of this invention. It is side surface sectional drawing of the shaft main body and end piece which show the joining method of the shaft main body and end piece by the friction welding method. It is side surface sectional drawing of the shaft main body and end piece which show the joining method of the shaft main body and end piece by the friction welding method. It is side surface sectional drawing of the cam shaft which shows the method of processing a protrusion part into a flange part. It is a side view of the camshaft which shows other embodiment of this invention. AA 'sectional view of FIG.

  1 to 4 show an embodiment of the present invention.

  The camshaft is rotatably supported by the cylinder head of the internal combustion engine, and the rotational force of the crankshaft is transmitted via a timing chain or the like. This is for opening and closing the exhaust valve. The camshaft has one end of a shaft body 1 as a shaft member made of a hollow cylindrical member, and an end piece as a shaft member made of a hollow cylindrical member having the same outer diameter as the shaft body 1 whose one end is closed by a flange. The other end of 2 is joined by a friction welding method. The shaft body 1 is provided with a cylindrical shaft portion 1a and a cam that is provided at a predetermined position in the axial direction of the shaft portion 1a so as to protrude outward in the radial direction from the outer peripheral portion of the shaft portion 1a. Part 1b.

  As shown in FIG. 2, the friction welding method means that frictional heat is generated by rubbing the members to be joined (here, the shaft main body 1 and the end piece 2) to soften each other member. As shown, it is a method of joining two members by applying pressure in the direction of pressing each other. When the shaft main body 1 and the end piece 2 are coupled by the friction welding method, a member at one end of the shaft main body 1 and the end are joined to a joint portion between one end of the shaft main body 1 and the other end of the end piece 2 as shown in FIG. Protruding portions 3 are formed in which the members at the other end of the piece 2 project radially outward and inward in the circumferential direction.

  As shown in FIG. 4, the projecting portion 3 positioned on the radially outer side is processed into a disk-shaped flange portion 3 a by forming both sides in the axial direction into a planar shape with a tool T.

  The camshaft configured as described above is configured such that the flange portion 3a engages with the thrust receiving groove 4a formed in the cylinder head cover 4 indicated by the one-dot chain line in FIG. Directional movement is regulated.

  As described above, according to the camshaft of the present embodiment, both axial sides of the projecting portion 3 generated in the circumferential direction at the outer peripheral portion of the joint portion of the shaft body 1 and the end piece 2 are planarized by the friction welding method. Since the disk-shaped flange portion 3a is provided by forming, the projecting portion 3 that has not been used or has been scraped off can be used for other purposes by simple processing. There is no need to attach a separate member or process the shaft body 1 or the end piece 2, and the manufacturing cost can be reduced.

  Further, since the flange portion 3a is used to restrict the axial movement of the camshaft itself by engaging the thrust receiving groove 4a formed in the cylinder head cover 4, the axial direction of the camshaft is controlled by the flange portion 3a. It is possible to reliably regulate the movement of.

  5 and 6 show another embodiment of the present invention. In addition, the same code | symbol is attached | subjected and shown about the component similar to the said embodiment.

  This camshaft is formed in a cylindrical shape in which the radially outer peripheral portion of the flange portion 3a is smooth in the axial direction by cutting or the like, and is further detected by the cam angle sensor 5 on the radially outer peripheral portion of the flange portion 3a. The groove 3b is provided so as to extend in the axial direction. The cam angle sensor 5 is a known sensor that can convert a magnetic change into a voltage signal.

  In the camshaft configured as described above, when the flange portion 3a rotates together with the camshaft, as shown in FIG. 6, the cam angle sensor 5 provided in the vicinity of the projecting portion 3 causes the outer peripheral portion of the flange portion 3a. The provided detection groove 3b is detected, and the rotation angle of the camshaft is detected.

  As described above, according to the camshaft of the present embodiment, similarly to the above-described embodiment, the protruding portion 3 can be used for other purposes by simple processing, and a separate member can be attached for other purposes. There is no need to process the shaft body 1 or the end piece 2, and the manufacturing cost can be reduced.

  Further, since the detection groove 3b provided in the flange portion 3a so as to extend in the axial direction and detectable by the cam angle sensor 5 is provided, the flange portion 3a can be used as a signal rotor by simple processing.

  In the above-described embodiment, the shaft body 1 and the end piece 2 are shown as hollow cylinders. However, the solid member may be joined by the friction welding method in the same manner as the shaft body 1 and the end piece 2. The protruding part 3 generated in the part can be used for other purposes.

  DESCRIPTION OF SYMBOLS 1 ... Shaft main body, 2 ... End piece, 3 ... Projection part, 3a ... Flange part, 3b ... Detection groove, 4 ... Cylinder head cover, 4a ... Thrust receiving groove.

Claims (4)

In a camshaft formed by joining a plurality of shaft members in the axial direction by a friction welding method,
When the shaft members are joined by the friction welding method, the axially opposite sides of the projecting portion generated in the circumferential direction are formed in a flat shape on the outer peripheral portion of the joint portion with the adjacent shaft member. A camshaft characterized by having a portion. The camshaft according to claim 1, wherein the flange portion is used to restrict axial movement of the camshaft itself by engaging with another member located in the vicinity thereof. The camshaft according to claim 1, wherein a detection groove for detecting a rotation angle provided to extend in the axial direction is provided on a radially outer peripheral portion of the flange portion. A method of manufacturing a camshaft formed by joining a plurality of shaft members in the axial direction by a friction welding method, and having a disc-shaped flange portion on an outer peripheral portion of a predetermined portion in the axial direction,
When the shaft members are joined by the friction welding method, the flange portion is formed by processing both sides in the axial direction of the protruding portion generated in the circumferential direction on the outer peripheral portion of the joint portion with the adjacent shaft member into a flat shape. A manufacturing method of a camshaft characterized by the above.

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