DD151126A5 - METHOD AND DEVICE FOR PRODUCING CAMSHAFTS - Google Patents

Abstract

While the object of the invention is to provide a method and an apparatus for economically producing camshafts having high utility value characteristics, the object is to reduce the manufacturing effort in the production of camshafts, wherein individual parts such as bearings, cams and support tube can be used , which can be produced by known methods, and the use of any desired material is possible in all individual parts. As a solution is now provided that can be pushed onto a support tube bearing points or cam-forming pipe sections and force and / or formschlüssig connected to the support tube. When hydromechanical expansion of the support tube, it is advantageous if a multi-part composed of discs die is provided which has a continuous the Auszendurchmesser of the support tube with the bearings and cams corresponding engraving.

Description

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Method and device for producing camshafts Field of application of the invention

The invention is applicable to the manufacture of camshafts.

Characteristic of the known technical solutions

Camshafts for valve control of internal combustion engines are produced by die forging and mainly by casting. With cast camshafts, one can achieve the necessary high wear resistance of the cams by means of inductive surface hardening. For this purpose, it is necessary to manufacture the shafts of cast iron with lamellar graphite and alloyed with chromium and molybdenum, wherein the cams still have to be ground after hardening.

The wear resistance of the cams can also be achieved in the cast state of cast iron without further treatment by forming the mold surface of the cams in the mold by means of cooling iron, thereby achieving a local faster solidification of the cast iron in the bersic'h of the cams and thereby the carbon itn structure precipitates as hard iron carbide instead of graphite. These shaped cams with sufficient surface hardness are also processed by grinding.

During casting, particular care must be taken to ensure that the area in which the pore surface of the cams solidifies more quickly for the necessary structural formation is precisely maintained. If the area is too small, the wear resistance decreases. If this particular cooling surface becomes too large, it will cause the brittleness because of its special brittleness

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a special risk of cracking and breakage.

The outer structure layer must also be completely free from defects.

Camshafts are also bath nitrided or tempered to achieve the necessary fatigue and wear resistance requirements.

Object of the invention

The object of the invention is to provide a method and a device for the economic production of high value-added properties camshafts.

Outline of the essence of the invention

The invention has for its object to reduce the manufacturing cost in the production of camshafts, with items such as bearings, cams and support tube can be used, which can be produced by known methods, and the use of any desired material in all items is possible.

According to the method, this object is achieved in that slid on a support tube bearing points or cam-forming pipe sections and non-positively connected to the support tube and / or. The connection can be done by soldering, shrinking, hydromechanical expansion of the support tube, mechanical expansion of the support tube or hydromechanical pressing against the support tube.

Preferably, pieces separated from the pipe being pressed with an uneven wall or deformed oval are used as pipe sections. The device for carrying out the method when connecting by hydromechanical

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Widening of the support tube is characterized by the fact that a multi-part composed of discs Gesenk is provided that a continuous the outer diameter of the support tube with the bearings and cam has corresponding engraving.

In the case of the camshaft produced according to the invention from tubular elements, there are a number of advantages over the camshafts produced by known methods, namely:

- Easier production of items such as bearings, cams and support tube by known methods;

- Use of any desired substance in all. Individual parts, in particular with the cams, for optimum fulfillment of the requirements placed on the camshaft with regard to fatigue strength and wear resistance j

- no after-treatment such as bath nitriding or tempering is required;

- After connecting the items to a camshaft only straightening the shaft and grinding the outer diameter of the bearings is required;

- there is a weight saving of about 50 % ;

- There is a cost savings. embodiment

The invention will be explained in more detail with reference to an embodiment. In the accompanying drawing show?

FIG. 1: a side view of an individual component

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standing camshaft in the die with tool for connecting the individual parts to a camshaft in working position;

Figure 1 a: a simplified representation of the application of an end piece; ,

Figure 2: a cross section through the die and through the camshaft in the region of a cam;

3 shows a longitudinal section through part of the camshaft in the region of a cam and an intermediate bearing j

Figure 4 i is a side view of a camshaft with cam and bearing j

Figure 5 is a longitudinal section of Figure 4j Figure '6; a cross section to Figure 5;

FIG. 7 shows a cross section to FIG. 5 with soldered cams;

FIG. 8 shows a cross section to FIG. 5 with shrunk-on cams;

FIG. 9J is a cross-section of FIG. 5 with a hydroformed tube and a uniform wall cam;

Figure 10: a die in longitudinal section.

The die shown in FIG. 1 is composed of individual, respectively divided disks 1. In these discs 1, the contours for the bearings or cams forming pipe sections are incorporated,

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As well as in this example, the ¹ contour for an end piece 2. For mechanical expansion of the tool indicated here is 3. Furthermore, in Fig. 1, the support tube 4 and the individual bearings or cam elements 5 are shown.

As can be seen from FIGS. 4 and 5, the support tube is connected in a form-fitting manner by hydromechanical expansion with the cam element. It is also possible for the cam element 5 to be shrunk onto the smooth or expanded tube. There are also widened bearings.

The insert used for the production, which can be used in a hydromechanical expansion device, is divided horizontally and vertically and consists of the smooth parts 6, the disks 1 for the cam elements 5 and for the bearing parts.

In FIGS. 6 and 8, a cam member 5 made up of a pipe having a nonuniform wall is shown, and in FIGS. 7 and 9, a cam member 5 made of a pipe having a uniform wall is shown.

In the assembled from the discs 1 die, the support tube 4 and the cam elements 5, which may consist of different materials used. In this die hydromechanical expansion of the support tube 4 and the cam elements 5 are pressed together in such a way that a positive connection is formed; Furthermore, the wall of the support tube 4 presses into the recesses, the discs 6, whereby the required bearings arise.

It is also conceivable to use cam elements made of strip strips, which are slotted on the support tube side, and to use fittings between the support tube and sheet metal strip,

Claims (8)

AP P 01 L / 221 394 '221394 - 6 - 57 554 27 Invention claim 1. A process for the production of camshafts, characterized in that pushed onto a support tube bearing points or cam-forming Rohrabsennitte and non-positively and / or positively connected to the support tube. 2. Method according to item!, Characterized in that the connection is effected by soldering. , , 3. The method according to item 1, characterized in that the connecting erfplgt by shrinking. 4. The method according to item 1, characterized in that the connection is effected by hydromechanical expansion of the support tube. 5. The method according to item 1, characterized in that the connection is effected by mechanical expansion of the support tube. 6. The method according to item 1, characterized in that the connection takes place by hydromechanical pressing on the support tube ·. 7. Method according to points 1 to 6, characterized by the fact that pieces cut off from a pipe pressed with an uneven wall or oval shaped are used as pipe sections. 22 1 394 - 7 - 8. A device for carrying out the method according to item 4, characterized in that a multi-part of discs (1) composite die is provided which has a continuous the outer diameter of the support tube (4) with the bearings and cams corresponding engraving. For this .... ^ .. ". Pages drawings