# US 9,038,270 B2 · Method for the production of a tubular body, and control arm produced by this method

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- Number: US 9,038,270 B2
- Document ID: US9038270B2
- Status: Granted
- Kind: B2
- Application number: 13/648,046
- Filed: 2012-10-09
- Published: 2013-10-17
- Granted: 2015-05-26
- Earliest claimed: 2011-10-10
- Assignees: Benteler Automobiltechnik GmbH
- Applicants: Benteler Automobiltechnik GmbH
- Inventors: Ragnar Holthe
- Web page: https://patentgrep.com/patent/US9038270B2

## CPC

- B29D 23/00: Producing tubular articles (B29D24/00 takes precedence)
- B21C 23/183: {by forward extrusion}
- B21K 1/763: {Inner elements of coupling members}
- B21K 21/08: Shaping hollow articles with different cross-section in longitudinal direction, e.g. nozzles, spark-plugs
- Y10T 29/49474: Die-press shaping
- Y10T 29/49622: Vehicular structural member making
- Y10T 74/2142: Pitmans and connecting rods
- B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00)
- B21C: MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21K: MAKING FORGED OR PRESSED METAL PRODUCTS, e.g. HORSE-SHOES, RIVETS, BOLTS OR WHEELS (making particular articles by working sheet metal without essentially removing material B21D; processing wire B21F; making pins, needles or nails B21G; making particular articles by rolling B21H; forging machines, pressing machines, hammering machines, in general B21J; making chains B21L; plating B23K)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

In a method of making a tubular body, material is pressed through a die of a forming tool into a first mold cavity disposed in downstream relationship to the die to produce a first end piece. A mandrel is then moved in a direction of the die to thereby displace the mold cavity in the same direction and to extrude a tubular center piece to adjoin the first end piece. The mandrel is then replaced by a mold having a second mold cavity to mold a second end piece to adjoin the center piece.

## Claims

### Claim 1

A method of making a tubular body, comprising:
pressing a material through a die of a forming tool into a first mold cavity disposed in downstream relationship to the die to produce a first end piece;
moving a mandrel in a direction of the die to displace the mold cavity in the same direction and to thereby extrude a tubular center piece adjoining the first end piece; and
replacing the mandrel by a mold having a second mold cavity to mold a second end piece adjoining the center piece.

### Claim 2 (depends on 1)

The method of claim 1, wherein the material includes predominantly aluminum, and further comprising heating the material to a forming temperature in the range from 450° C. to 550° C.

### Claim 3 (depends on 2)

The method of claim 2, wherein the material is heated in the forming tool to the forming temperature.

### Claim 4 (depends on 2)

The method of claim 2, wherein the material is heated to the forming temperature before being introduced into the forming tool.

### Claim 5 (depends on 1)

The method of claim 1, further comprising heating the forming tool, at least in an area thereof, to a temperature in the range from 400° C. to 540° C.

### Claim 6 (depends on 1)

The method of claim 1, wherein the material is a magnesium material.

### Claim 7 (depends on 1)

The method of claim 1, wherein the material is a plastic.

### Claim 8 (depends on 7)

The method of claim 7, wherein the plastic is a fiber-reinforced plastic.

### Claim 9 (depends on 1)

The method of claim 1, further comprising pressing additional material into the second mold cavity for molding the second end piece.

### Claim 10 (depends on 1)

The method of claim 1, wherein the mandrel has a diameter which varies in a longitudinal direction so as to vary a width of an annular gap between the die and the mandrel as a function of a position of the mandrel in relation to the die.

### Claim 11 (depends on 1)

The method of claim 1, further comprising molding in the second mold cavity at least one opening in the second end piece by moving at least one mandrel in the second mold cavity.

### Claim 12 (depends on 1)

The method of claim 1, further comprising balancing a pressure between an interior of the tubular center piece and the surroundings by providing the mandrel with an air opening.