Method for producing a component

Abstract

In order to reduce both the weight and the production costs in the case of vehicle chassis components consisting of at least two parts, a first part is made as a sheet component by press hardening and the second part is produced by a conventional production method, which does not include press hardening. The part produced by press hardening forms a structural component, whereas the other component serves to stiffen the part produced by press hardening.

Claims

1. A method of producing a component for a motor vehicle that comprises at least first and second individual parts which are connected to one another, the method comprising: producing the first individual part, which is a sheet metal part, by press hardening in a non-machining deformation process, providing a front end of the first individual part with an opening in which a fitted component is receivable, producing the second individual part by a production process without press hardening, producing at least one mounting point in a free end of the second individual part in which a further structural component is receivable, and fixing the first and the second individual parts to each other such that the opening of the first individual part is located at one end of the component for the motor vehicle and the at least one mounting point of the second individual part is located at an opposite end of the component for the motor vehicle, producing jaw-shaped openings in a back end of the first individual part, and adhesively bonding the first and the second individual parts to one another such that the at least one mounting point of the second individual part is supported by the jaw-shaped openings in the back end of the first individual part.

2. The method according to claim 1, further comprising producing the second individual part as a carbon-fiber-reinforced plastic part.

3. The method according to claim 1, further comprising producing the first individual part which when the component is in service, will be substantially subjected to force/torque that occur, as the press-hardened sheet metal part, and producing the second individual part, which serves primarily to stiffen the component as a whole, by the cold-forming process, and fixing the first and the second individual parts to each other such that the component is formed as either a longitudinal member or a transverse link of a motor vehicle.

4. The method according to claim 1, further comprising producing the first individual part, as the press-hardened sheet metal part, which, when the component is in service, will be substantially subjected to force/torque that occur and producing the second individual part, as a carbon-fiber-reinforced plastic part, which serves primarily to stiffen the component as a whole.

5. A method of producing a component for a motor vehicle that comprises at least first and second individual parts which are connected to one another, the method comprising: producing the first individual part, which is a sheet metal part, by press hardening in a non-machining deformation process, providing a front end of the first individual part with an opening in which a fitted component is receivable, producing the second individual part by a production process without press hardening, producing at least one mounting point in a free end of the second individual part in which a further structural component is receivable, fixing the first and the second individual parts to each other such that the opening of the first individual part is located at one end of the component for the motor vehicle and the at least one mounting point of the second individual part is located at an opposite end of the component for the motor vehicle, producing the second individual part, which is a sheet metal part, by a sheet cold-forming process, and producing the at least one mounting point by rolling-in the free end of the second individual part.

6. The method according to claim 5, further comprising forming a bend in a back end of the first individual part, and welding the first and the second individual parts to one another such that the at least one mounting point of the second individual part is supported by the bend in the back end of the first individual part.

7. The method according to claim 6, further comprising making at least one of a strength and a hardness of the first individual part lower in an area of a weld seam than in press-hardened areas.

8. A method of producing a chassis component for a motor vehicle, the method comprising: producing a first individual part from a sheet metal during a non-machining deformation process by press hardening; producing an opening in a front end of the first individual part for receiving either a ball head or an axle journal, and producing a bend in a back end of the first individual part; producing a second individual part by a production process without press hardening; producing a mounting point in a free end of the second individual part for receiving a rubber mounting; and connecting at least the first individual part with the second individual part to form the chassis component such that the mounting point in the free end of the second individual part is supported against the bend in the back end of the first individual part and an opposite end of the second individual part is supported at the front end of the first individual part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) To explain the invention further, reference is made to the drawings in which two preferred example embodiments are illustrated in simplified form. The figures show:

(2) FIG. 1: A perspective view of a longitudinal member for a motor vehicle, which consists of a first, press-hardened individual part and a second, cold-formed individual part that serves as reinforcement,

(3) FIG. 2: A perspective view of a transverse fink for a motor vehicle, which consists of a first, press-hardened individual part and a second, cold-formed individual part that serves as reinforcement.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) The longitudinal member 1 for a motor vehicle shown in FIG. 1 consists of the two individual parts 2 and 3, the individual part 2 being a structural component and the individual part 3 functioning as a reinforcing component.

(5) The individual part 2 is made by press hardening from a hardened steel such as 22MnB5. To achieve production in as geometrically simple a manner as possible during press hardening, this individual part 2 is bent into a U-shaped cross-section and is therefore open downward. It has a longitudinally slightly angled extension. At its front end an opening is provided for receiving a fitted component, for example a ball head. The back end is bent slightly upward.

(6) Press hardening or mold hardening is a method in which, in one process step, both the shaping of a sheet component without machining and its heat treatment are combined. For this the sheet blank heated to above the austenitizing temperature is placed in a cooled deformation die and then quenched. This produces a martensitic structure with very high tensile strength.

(7) The individual part 3 is produced by conventional cold forming from a suitable steel sheet, and essentially follows the contour of the individual part 2. For this a number of shaping steps may be needed, which can be carried out without problems during cold forming. Thus, without problems a necessary mounting point 4 can also be integrated, which in this case is produced by rolling-in a free end of the individual part 3. In addition the mounting point 4 supports the slightly upward-bent back end of the individual part 2.

(8) The two individual parts 2 and 3 are connected to form a profile with a closed cross-section by a weld joint, for example by spot welding, step welding or a continuous seam. When welding a press-hardened component it must be kept in mind that under high dynamic loading, starting from the weld joint cracks can form which can lead to failure of the component. To avoid this, the area of the weld joint on the press-hardened component should be exempted from hardening during its production.

(9) FIG. 2 shows a transverse link of a motor vehicle as the second example. This transverse link 5 also consists of two individual parts 6 and 7, namely the structural component 6 and the reinforcing component 7.

(10) The structural component 6 is again made by press hardening from a hardenable steel, preferably 22MnB5. It has a contour as geometrically simple as possible, in that it has a U-shaped cross-section so that it can be produced in a pressing process. In its forward area it has an opening to receive a fitted component, for example an axle journal.

(11) To form a profile with a closed cross-section, this transverse link 5 is connected to the second individual part 7 which closes off the U-shaped profile from below. Again, the individual part 7 can be made by cold forming from a suitable steel sheet. It includes the necessary mounting points 8, which can be produced by a multi-step deformation process. The mounting points 8 are supported against jaw-shaped openings in the structural component 6, in order to produce greater stability of shape during operation.

(12) In this case too welding can be considered for the joining method, and in that case the special features explained above for the press-hardened component should be borne in mind.

(13) Instead of a second individual part made of steel sheet, some other material can also be chosen. For example it is conceivable to make that component of carbon-fiber-reinforced plastic, which is then adhesively bonded to the first individual part. This has the advantage that besides a further reduction in weight, the problems associated with welding a press-hardened component are avoided. Thus, the production costs of the press-hardened component are reduced.

INDEXES

(14) 1 Longitudinal member 2 Individual part of 1 2 Individual part of 1 4 Mounting point on 3 5 Transverse link 6 Structural component of 5 7 Reinforcing component of 5 8 Mounting points on 7