Descriptive report for patent of invention for "HALF FRAME MANUFACTURING PROCESS FOR A MOTOR VEHICLE"

The present patent refers to a half frame manufacturing process for a motor vehicle, more particularly trucks .

Description of the Prior Art

The current manufacturing process of a half frame for a motor vehicle results in a product having drawbacks.

After cutting the blank, this is formed using presses provided with punches in the preforming step. After preform, the blank proceeds to the chamfer forming step and calibration.

The chamfer is provided to allow a recess when joining the two half-frames to welding deposit to join both parts. Using the current process, the blank chamfer is provided with burrs, thus requiring the use of additional welding to join both parts, in addition to provide a poor finishing.

In brief, the current process has the following drawbacks : - opening of the joint of both frames, thus causing welding leakage,-

- burrs due to excessive material;

- deformation on the legs side,-

- misalignment at the joints of the half frames; - lack of uniformity of the welding opening

(groove) .

Brief Description of the Drawings

Figure 1 is a step of the prior art process;

Figure 2 is a second step of the prior art process;

Figure 3 is a third step of the prior art process; Figure 4 is the first step of the process object of the present application;

Figure 5 is the second step of the process object of the present application;

Figure 6 is the third step of the process object of the present application; and

Figure 7 is the last step of the process object of the present application.

Detailed description of the drawings

First of all, Figures 1, 2 and 3 show the current manufacturing process of a motor vehicle half frame.

The first step of the process is obtaining a blank A, cut it into the desired shape by shearing, plasma-cutting or oxycut .

Subsequently, the blank A is heated and preformed by means of punch B and matrix D, as it can be seen in Figure 1.

Additionally, blanks A have a 90° surface and, to obtain the required angulation (chamfer) for welding purposes, it is provided calibrated and formed, as showed in Figure 2, thus originating chamfers B. However, chamfers B are provided with burrs E as a result of excessive material, thus causing opening C of the joint of the two frames and causing welding leakage, deformation of the side of legs D, misalignment at the half frames joint and lack of uniformity of the welding opening (groove) .

Further, the welding penetration ranges only from 50% to 70% of the formed region.

In order to solve the drawbacks mentioned above, as it can be seen from Figure 4, a blank 1 is provided, being cut into the desired shape with an ideal chamfer to obtain the final product .

In a second step, the blank 1 is heated and preformed to reach a conformation that complies with the final axis strength conditions by means of a punch 2 and matrix 3, as showed in Figure 5.

Subsequently, blank 1 is calibrated, punch 2 is provided with a recess 2a, with specific angulation, thus allowing the calibration of the chamfers 4 to receive the welding, as it will be explained below. Chamfers 4 are provided with its surface nearly smooth and having no burrs, thus subsequently providing a clean welding with no material waste both from welding and blank.

After those steps, as it can be seen up to Figure

6, the blanks 1 are ready to be placed with chamfers 4 facing each other, forming a region 5 to receive the welding.

The welding to be deposited in region 5 will be well accommodated, as region 5 is totally filled above 80%.

Further, this new process does not require the part to undergo the milling step after being formed since, simultaneously to the part calibration step, the chamfers 4 intended to receive the welding are provided (Figure 7) .

It will be obviously realized that although the abovementioned has been described as an illustrative example of

the present invention, all other changes and variations of the invention, as it would be appreciated by those skilled in the art, are regarded to be within the wide scope and ambit of the present invention as per the attached claims.