Universal bellhousing, system and method therefore

Abstract

A method of forming a universal bellhousing which may be adapted to a variety of automotive engine and transmission combinations is disclosed. The bellhousing is made by spin forming a sheet of material and welding a transmission plate to the cone. The cone and transmission plate are indexed to mount to a specific, desired engine-transmission combination.

Claims

1. A method of forming a universal bellhousing and adapting the universal bellhousing such that it is capable of joining a desired engine and transmission combination comprising the steps of: forming a structure by creating a hole through a center of a sheet of rigid material, placing the sheet on a spin-forming machine, spinning the sheet about the hole, and applying force normal to a surface of the sheet, thereby forming the structure having a first end, a second end, and a first height, and forming a flange integrally with the structure about the first end of the structure, the flange extending radially from an axis of rotation of the sheet, said structure having a first opening at the first end and a second opening at the second end, the first and second ends being coaxial; said structure being adaptable to mate a plurality of engine and transmission combinations; after the structure has been formed, selecting a profile stored in the memory of a cutting tool that corresponds to an engine model and a transmission model of the desired engine and transmission combination, wherein the profile includes an engine mounting pattern, an engine size, a transmission mounting pattern, and a transmission size; adapting the previously formed structure to the desired engine and transmission combination by cutting the structure at the second end to a second height, wherein the second height corresponds to the selected profile; cutting the flange such that the flange has a profile that corresponds to the engine model; affixing a transmission plate from a plurality of interchangeable transmission plates onto the second end of the structure substantially parallel to the flange, wherein the transmission plate has a profile that corresponds to the transmission model; leveling the transmission plate relative to the flange; machining a hole pattern into the flange that corresponds to the engine mounting pattern, and machining a hole pattern into the transmission plate that corresponds to the transmission mounting pattern.

2. The method of claim 1, wherein the structure is formed by internal spin forming.

3. The method of claim 1, wherein the structure is formed by external spin forming.

4. The method of claim 1, wherein the structure has a cone shape.

5. The method of claim 1 further comprising a step of machining at least one opening into a wall of the structure corresponding to the engine model and the transmission model.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In addition to the features mentioned above, other aspects of the present invention will be readily apparent from the following descriptions of the drawings and exemplary embodiments, wherein like reference numerals across the several views refer to identical or equivalent features, and wherein:

(2) FIG. 1 is a perspective view of the bellhousing according to a preferred embodiment;

(3) FIG. 2 is a perspective view of the bellhousing from an opposite end;

(4) FIG. 3 is an end view of the preferred embodiment;

(5) FIG. 4 is a side view of the preferred embodiment;

(6) FIG. 5A shows a method of forming the bellhousing by use of an internal spin forming machine;

(7) FIG. 5B shows a method of forming the bellhousing by use of an external spin forming machine; and

(8) FIGS. 6A-F shows the various steps in producing the bellhousing according to the preferred embodiment.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S)

(9) An embodiment of this invention is a universal bellhousing design and manufacturing process that allows a small number of housing sizes to be configured to mate with a large number of engine and transmission models. This is an important aspect of this invention as each engine and transmission has a unique mounting pattern and size and thus would require separate tooling.

(10) As shown in FIGS. 1-4, the bellhousing 10 generally comprises a cone 12, a flange 20, and a transmission plate 30. The flange 20 has a hole pattern 24 corresponding to a mating surface on an engine. The transmission plate 30 also has a hole pattern 34 and a profile 32 corresponding to a transmission. The cone 12 also features a number of openings 14 which allow the bellhousing 10 to fit about the engine transmission interface while allowing access for the shifter cable and starter. The arrangement of the openings 14, and the hole pattern 24 on the flange 20 and hole pattern 34 on the transmission plate 30 are shown merely by example, as each engine-transmission combination may require different shapes or arrangement of these features.

(11) As previously discussed, there are different methods available for the construction of bellhousings. These methods include hydroforming, casting, or pressing. Each of these methods is not preferable for custom made bellhousings because of an increased startup cost as well as limitations in the type of material which may be used.

(12) The present invention contemplates the use of spin forming to form the basic bellhousing shape. The process is generally shown in FIGS. 5A and 5B, with the specific assembly process for the bellhousing 10 shown in FIGS. 6A-F.

(13) FIGS. 5A and 5B show alternative methods of spin forming a sheet of steel into a cone for use in the bellhousing 10. FIG. 5A shows the use of an internal type spin forming and FIG. 5B shows the use of an external type spin forming.

(14) FIG. 5A shows internal-type spin forming. A sheet of steel 40 is placed onto the spinning machine 50 with the central axis 58 passing through the indexing hole 42. The sheet 40 is then secured by a support 60 and spun at a high speed. As the sheet 40 spins, a roller 56 exerts force downward onto the sheet 40 forcing it into the cavity 52. The sheet 40 is shaped to the cavity 52 while leaving a flange 20 integrally formed about the edge of the cavity 52.

(15) External spin forming is generally shown in FIG. 5A. In this method, a sheet of steel 40 is placed onto a spinning machine 50 atop a mandrel 54. The central axis 58 passes through the indexing hole 42 and the sheet 40 is secured with a support 60. The sheet 40 is then spun at high speed and a roller 56 forces the sheet 40 about the mandrel 54. In this manner, a cone shape is formed about the mandrel 54 with a flange 20 integrally formed with the cone 12. As shown in FIG. 5B, once the cone 12 is formed, the flange 20 is not level to the cone 12. Therefore, a separate step is required to level the flange 20 prior to final machining. This step could be performed by a press or other similar process known in the art.

(16) As shown in FIGS. 6A-F, an exemplary embodiment of the process starts with a single sheet 40 of steel, preferably ⅜″ for safety reasons.

(17) Next, an indexing hole 42 is drilled through the center of the sheet 40; this hole 42 is preferably approximately 1″ in diameter and is used to align the sheet 40 onto the spinning machine 50.

(18) The sheet 40 may then be formed by spin forming into a cone 12 with a narrow end 16, a wide end 18, and a flange 20 extending from the wide end 18. The cone is defined by its height, diameter and angle of taper.

(19) The cone 12 is next cut to a preferred height relative to the flange 20. This distance is determined by the precise specifications between the engine and transmission. Along with cutting the cone height, noncritical operations are also performed. The openings 14 are also cut and the profile 22 of the flange is cut. These features are not held to the tight tolerances of the transmission and engine interfaces, and so may be performed at this stage. The cuts are preferably performed by an automated 5-axis laser cutter. Being automated, such as by computer numerical control (CNC), individual bellhousing profiles may be stored and retrieved according to production demands. The 5-axis laser cutter eliminates error due to moving the part and allows cuts to be made at a variety of positions and angles.

(20) The transmission plate 30, already having a profile 32 and center hole 36 for aligning with the transmission, is then welded onto the narrow end 16 of the cone 12. As with the flange profile 22, the transmission profile 32 is not required to be held to a tight tolerance. Therefore, a number of transmission plates 30 corresponding to a variety of different transmissions may be cut before welding the transmission plate 30 to the bellhousing 10. The central hole 36 of the transmission plate 30 is within a tolerance (e.g., 0.1″) of the final dimension. This central hole 36 is centered onto the cone 12, thereby ensuring concentricity between the flange 20 and transmission plate 30.

(21) As a final step, the bellhousing 10 is moved to a table for precision machining. First, the transmission plate 30 and flange 20 are leveled relative to one another to a precision tolerance (e.g., 0.001″). The hole pattern 24 in the flange 20 is then cut, including precision fit dowels. The central hole 36 and hole pattern 34 of the transmission plate 30 are also cut at this time, corresponding to the selected transmission. All of the operations in the final step are performed on a single machine, thereby ensuring a precise tolerance (e.g., 0.001″).

(22) As has been previously described, the method of forming the bellhousing allows for a variety of transmission and engine combinations to be assembled together through the use of a single bellhousing. It should be appreciated to those skilled in the art that alternative embodiments of the method of forming the bellhousing may also be used. For example, the cone may be formed by hydroforming, pressing, or casting. The remaining steps would then be followed as described above in order to produce a universal bellhousing.

(23) Hydroforming is a process by which a form is pressed out of a sheet of metal by the use of hydraulic pressure. The sheet of metal is placed onto a flexible diaphragm and a male mold is pressed into the sheet. Hydraulic pressure provides the energy for deforming the sheet. The flexible diaphragm provides resistance, thereby eliminating the need for a complimentary female mold. This type of metal forming is inexpensive as it does not require complimentary molds and can be used for a variety of shapes.

(24) Pressing is a process by which a form is pressed out of a sheet of metal by a ram. The sheet of metal is placed onto a female die and a ram forces a male die onto the sheet. The sheet is then formed into the shape formed by the dies. This process is faster than hydraulic pressing, but requires more startup cost to form the dies.

(25) Casting is a process of depositing molten metal into a form and then cooling the metal to set the form. The form must be designed for each individual bellhousing. This process requires a high startup cost, and is generally not suitable for use with high-strength steel. However, the process is preferred for large quantities of products.

(26) Other alternative processes obvious to those in the field of art are considered to be included in this invention. The above description is merely a single embodiment and limitations to the invention are described in the patent. Any embodiment of the present invention may include any of the optional or preferred features of the other embodiments of the present invention. The exemplary embodiments herein disclosed are not intended to be exhaustive or to unnecessarily limit the scope of the invention. The exemplary embodiments were chosen and described in order to explain the principles of the present invention so that others skilled in the art may practice the invention. Having shown and described exemplary embodiments of the present invention, those skilled in the art will realize that many variations and modifications may be made to the described invention. Many of those variations and modifications will provide the same result and fall within the spirit of the claimed invention. It is the intention, therefore, to limit the invention only as indicated by the scope of the claims.