HOT , COLD OR WARM FORGING PROCESS FOR FORMING HOLLOW METALLIC PARTS AND ASSOCIATED PUNCH

The invention herein refers to a forging manufacturing process in several steps which result is the reduction of material waste (natural waste of the process), particularly, but not mandatorily used in hot, cold or warm forging where the final product is a hollow metallic part (bushings, rings, etc.). Description of the State of the Art

For simplicity, the description and the examples are for parts that have external and internal cylindrical shapes, where the innovative process can be used in hollow parts that have any external and internal geometric shapes.

Currently, to obtain a particularly hollow metallic part that has a passing or hollow opening (for example, inner bushings and rings of angular contact bearings) by hot, cold or warm forging process, four conformation steps of said part are necessary:

1. cut the raw material (bar), generally by shearing, obtaining a blank, which composes the initial material of the forging process;

2. pressing the blank longitudinally, flattening it and forming a disk;

3. pre-formation of the part creating a recess on the disk and obtaining a cup;

4. cut of the bottom of the cup, forming a void and hollow part, causing a waste of natural material of the process (shred). The shred that correspondents to the cut of the bottom of the cup has high dimensions in relation to the shape and dimension of the final part, which is a substantial waste of material. Obviously, that means a substantial waste on weight of raw material.

Due to flaws caused when punching, that is, deformity and even- tual cut of material through puncture, there has always been the need to e- nhance the well-known techniques.

Japanese patent cases JP 10146625, JP 4269200 and JP

55165231 talk about manufacturing processes that have in one of their manufacturing steps material punching and cut which is done through conic puncture and which objective is to assure more dimensional precision to the passing hole of the part during this manufacturing step through its precise positioning on the part, which is reached through the use of conic or truncated conic punctures.

The North American patent US 5.816.093 talks about another manufacturing process that uses a conic puncture to do a hole. However, the objective of that patent is a manufacturing process and its respective tools, more specifically, the drilling process of walls of cylindrical parts, where the drilling and enlargement operations of the hole are subsequently done using the same tool which does the drilling operations (with the first section of the tool - puncture) and the enlargement of the same hole (with the second conic section of the same puncture), enabling the performance of two operations simultaneously.

Japanese patent JP 833679 deals with a process which objective is to perform the puncturing step to manufacture a specific part without creating bur, that is, material waste on the edges of the part that must be submitted to an extra operation, increasing the manufacturing cost of the part. This is also applicable to the Japanese case JP 57028635.

It is important to observe that, considering the previous known techniques for puncturing with conic or truncated conic shape or prism shape or any trunk of prism, in none of them the proper focus was given to the significant reduction of material wasted during the process, where the main focus of the already granted patents is different.

Therefore, a forging process that enabled, with no changes to the machinery and material, a substantial reduction on the amount of wasted material as natural waste of the process without increasing the manufacturing cost of the forged product had not yet been created. Objectives of the Invention

The objective of the invention herein is a hot, cold or warm forging manufacturing process of a specific product, for instance, a ring with an

outer flange, a bushing or an inner ring of an angular contact bearing, where said product is obtained through some steps, where the process enables the obtainment of a final part with a substantial reduction on the mass of the material wasted as a natural waste of the process, when compared to well- known processes.

The objective of the invention herein is also a tool developed and created to pre-form the part, where the shape of said tool enables the obtainment of a pre-formed part which shape will enable mass reduction of the material wasted as natural waste of the process, when compared to well- known processes.

Brief Description of the Invention

The objectives of the invention herein are reached by a hot, cold or warm mechanic conformation process of a part, where the process encompasses the following steps: (i): cut of raw material, normally through shearing, to obtain a blank;

(ii): pressing the blank along its longitudinal geometrical axis to obtain a disk;

(iii): disk conformation through forging to obtain a pre-formed part, the forging process creating at least one recess on the pre-formed part, the recess having a bottom area;

(iv): removal of a section of the bottom area; and (v): conformation by forging the pre-formed part to obtain a final hollow part, where the flat projection of the bottom of the recess, perpendicular to the longitudinal geometric axis of the pre-formed part is lower than or equal to 75% of the smallest inner area of the final part measured on a cross section.

Also, the objectives of the invention herein are reached by a hot, cold or warm mechanic conformation process of a part, where the process has the following steps:

(i): cut of raw material, normally through shearing, to obtain a

blank;

(ii): pressing the blank along its longitudinal geometric axis to obtain a disk;

(iii): disk conformation through forging to obtain a pre-formed part, the forging process creating at least one recess on the pre-formed part, the recess having a bottom area;

(iv): removal of a section of the bottom area; and

(v): forging conformation of the pre-formed part to obtain a final hollow part, where the width of the section removed is smaller than or equal to 50% of the linear dimension of the section removed, measured perpendicularly to the longitudinal geometric axis of the section removed.

Additionally, the objectives of the invention herein are reached by a puncture for a mechanic conformation tool that has a first perforation secti- on, an intermediary enlargement section and a later finishing section, in such a way the transversal portion of the first section is smaller than or equal to

75% of the transversal section area of the later finishing section.

In order to optimize the forging process object of the invention herein, the puncture abovementioned was created to be used in a tool that comprises a top plaque and a base plaque, and where, on the top plaque, there is the puncture responsible to perforate, enlarge and give the finishing of the hole of the part in a single operation.

Said puncture cooperates with its respective matrix, placed on the base plaque and made of the matrix itself and its respective counter puncture/extractor (part of the tool that is responsible for absorbing the impact of the puncture and expel the part from the matrix where it is conformed), and said matrix is built in such a way to receive said puncture every time there is a "beating" of the machine (press) during the forging process, forming a "male-female" set. Summarized Description of the Drawings

The invention herein will be now described in details based on two examples represented on the drawings. For better understanding, the

Figures are divided in five groups according to the examples. The Figures show:

A) conventional process to forge a ring with outer flange:

Figure 1 - Obtainment of the cylinder or blank cutting the bar by shearing, representing the first step of the conventional manufacturing process (forging) of a part with an outer flange.

Figure 2 - Cylinder or blank pressed on its longitudinal direction forming a disk, representing the second step of the conventional manufacturing process of the part with outer flange. Figure 3 - Pre-formation of the part, obtaining a cup, representing the third step of the conventional manufacturing process of the part with outer flange.

Figure 3.1 - Formation process of the cup. Figure 4 - Cut of the bottom of the cup, forming a part with its in- ner area void and passing or hollow, representing the forth step of the conventional manufacturing process of the part with outer flange.

Figure 4.1 - Cutting process of the bottom of the cup. Figure 5 - Formation of the final part, representing the fifth and last step of the conventional manufacturing process of the part with outer flange.

Figure 5.1 - Formation process of the final part.

B) alternative conventional process to forge a ring with an outer flange:

Figure 6 - Obtainment of the cylinder or blank generally cutting the bar by shearing, representing the first step of the manufacturing process (forging) of a part with an outer flange.

Figure 7 - Cylinder or blank pressed on its longitudinal direction forming a disk, representing the second step of the conventional process.

Figure 8 - Pre-formation of the part, obtaining a cup, representing the third step of the conventional manufacturing process. Figure 8.1 - Formation process of the cup

Figure 9 - Cut of the bottom of the cup, obtaining a final part with its inner area void and passing or hollow, representing the forth step of the

conventional process.

Figure 9.1 - Cut process to obtain the final part.

C) conventional process to forge a bushing:

Figure 10 - Obtainment of the cylinder or blank generally cutting the bar by shearing, representing the first step of a conventional manufacture (forging) process of a part without outer flange.

Figure 11 - Cylinder or blank pressed on the longitudinal direction forming a disk, representing the second step of the conventional manufacturing process of the part without outer flange. Figure 12 - Pre-formation of the part, obtaining a cup, representing the third step of the conventional manufacturing process of the part without outer flange.

Figure 12.1 - Formation process of the cup. Figure 13 - Cut of the bottom of the cup, obtaining a part with its inner area void and passing or hollow, representing the forth and last step of the conventional manufacturing process of the part without outer flange. Figure 13.1 - Cutting process to obtain the final part.

D) innovative process to forge a ring with outer flange:

Figure 14 - Obtainment of the cylinder or blank generally cutting the bar by shearing, representing the first step of the manufacturing process (forging) object of the invention herein.

Figure 15 - Cylinder or blank pressed on its longitudinal direction forming a disk, representing the second step of the manufacturing process object of the invention herein. Figure 16 - Pre-intermediary form (or cup) with its central part

(bottom) having a relatively small diameter and a relatively reduced width in relation to the rest of the part, representing the third step of the manufacturing process object of this invention.

Figure 16.1 - Pre-intermediary formation process (cup). Figure 17 - Cut of the bottom of the cup making its inner area void and passing or hollow, representing the forth step of the manufacturing process object of this invention.

Figure 17.1 - Cutting process of the bottom of the cup.

Figure 18 - Formation of the finished part with its inner area void and passing or hollow, representing the fifth and last step of the manufacturing process object of this invention. Figure 18.1 - Formation process of the finished part.

Figure 18.2 - Cutting process of the bottom of the cup and formation of the finished part, sequentially done in the same operation. E) innovative process to forge a bushing:

Figure 19 - Obtainment of the cylinder or blank cutting the bar by shearing, representing the first step of the manufacturing process (forging) object of this invention.

Figure 20 - Cylinder or blank pressed on its longitudinal direction forming a disk, representing the second step of the manufacturing process object of this invention. Figure 21 - Pre-intermediate form (or cup) with its central part

(bottom) having a relatively small diameter and a relatively reduced width in relation to the rest of the part, representing the third step of the manufacturing process object of this invention.

Figure 21.1 - Pre-intermediate formation process (cup). Figure 22 - Cut of the bottom of the cup with its inner area void and passing or hollow, representing the forth step of the manufacturing process object of this invention.

Figure 22.1 - Cutting process of the bottom of the cup.

Figure 23 - Formation of the finished part with its inner area void and passing or hollow, representing the fifth and last step of the manufacturing process object of this invention.

Figure 23.1 - Formation process of the finished part.

Figure 23.2 - Cutting process of the bottom of the cup and formation of the finished part sequentially done on the same operation. Detailed Description of the Figures

This invention refers to a hot, cold or warm forging manufacturing process of a specific product, for example, an inner ring of angular contact

bearing or a bushing, as well as the inner ring or the bushing itself obtained by the process.

However, its first objective is to describe the steps of a conventional forging process used nowadays on the manufacture of this type of com- ponent, which causes, as undesirable side effect, a high waste of material, of 25% approximately. It is important to observe that this conventional forging process can be seen on Figures 1 to 13.

Essentially, a conventional forging process has the following steps: 1. cutting a metallic bar or similar by shearing forming a cylinder or blank 1 ,6,10, which composes the initial material of the forging process,

2. pressing the blank 1 ,6,10 along its longitudinal geometric axis to obtain a disk 2,7,11 ,

3. conformation of disk 2,7,11 by forging it creating a recess 31 ,81 ,121 on the pre-formed part 3,8,12 with a bottom area, where said preformed piece 3,8,12 is also known as cup

4. cut of the bottom area of the cup 3,8,12, forming a part 4a,9a,13a with its inner area hollow and passing (passing opening).

Remarks: If the part obtained after cutting the bottom area is not on its final form, as shown on Figure 4 item 4a, a forging operation can be performed in order to obtain the finishing, obtaining the finished part 5.

On a well-known process, Figure 1 ,6,10 represents the cylinder or metallic blank 1 ,6,10, right after the bar is cut, step that is previous to the pressing, which originates the transformation of said cylinder 1 ,6,10 on the flat disk 2,7,11 , shown on Figures 2, 7 and 11.

As seen on Figure 3,8,12 the cup 3,8,12 is formed using the puncture A ₁ I, N, of matrix B, J, P and the counter puncture/extractor C,K,O. Observe that, on the examples that illustrate conventional processes, the inner side walls of the inner area of the cup 8,12 have practically the same distance between each other, such as the ones of the final part 9a, 13a obtained after the conformation of the cup 8,12 done by the puncture L,Q and the matrix M, R, which are responsible for cutting the bottom of the cup and for

the obtainment of the shred 9b, 13b.

As previously mentioned, the conventional forging process, used for decades now, has drawbacks once nearly 25% of the initial weight of the blank is naturally put away during its execution as shred, and it is clear that such percentage can vary according to the shape and dimension of the final part, but always in higher levels.

The forging process object of this invention longs for, since its birth, a substantial reduction (at least 70%) of the quantity of material wasted on conformation operations (and it is more advantageous on the manufacture of small parts), with no counterpart on the increase of manufacturing cost of the forged product. It is important to consider that this enhanced process can be done in common presses (usually a banging operation) or in automatic presses, where all operations are performed each time the machine bangs. This invention can use the same equipment used on well-known conventional processes, which makes it even more convenient.

The forging process object of this invention, which allows the production of the same parts that are obtained with well-known processes, but by saving material due to the great reduction on the natural waste of process (shred), comprises the following steps: (i): cutting raw material by shearing to obtain a blank 14, 19,

(ii): pressing the blank 14,19 along its longitudinal geometric axis to obtain a disk 15,20;

(iii): disk conformation (forging), originating a pre-formed part 16,21 that contains at least one recess 162,212,213 (part usually called 'cup') which inner part has a conic, truncated conic shape or similar (non-passing opening) with dimensions previously estimated to reduce the area of the bottom of the recess (the one that will be cut originating the shred);

(iv): removal of a bottom section by shearing, producing a shred 17b,22b; and obtaining the hollow part 17a,22a (v): forging conformation of the pre-formed part 17a,22a already hollowed to obtain a final hollowed part 18,23, where steps (iv) and (v) can be performed in a single operation.

On step (i) a blank with optimized weight 14,19 which mass is at least 20% lower than the mass of a blank 1 ,6,10 used on conventional processes is sheared.

The innovative process allows the preparation of a blank 14,19 optimized on step (i) and the shred 17b, 22b cut on step (iv) has mass of at least 70% lower than the mass of a shred 4b,9b,13b of a part made of a non- optimized blank 1 ,6,10, and, in many cases, it is up to 85% lower.

Step (iv) is replaced by a cutting the bottom of the cup 16,21 forming a hollow part, that is not the final part 17a,22a originating shred 17b,22b, and finally, a formation step (v) of the final part 18,23 by forging. Steps (iv) and (v) can simultaneously be done or not.

Finally, the cup 16,21 obtained on step (iii) has previously estimated dimensions that reduce the width and the cut area of the part 17b, 22b object of the step (iv). In a first variation of the process object of this invention illustrated on Figures 14 to 18, Figure 14 refers to the cylinder 14, which has dimensions smaller than the cylinder shown on Figure 1 (which will be mentioned later), after the cut on the metallic bar, which will soon be pressed forming the flat disk 15, shown on Figure 15. Figure 16.1 shows the conformation step of the disk, from which the cup 16 is obtained through the puncture S together with the matrix T and the counter puncture/extractor U, making a "male-female" set. It is possible to notice that a recess 162 is made in this phase that does not pass on the part and that the bottom of this recess has its central area destined to a further cut and it has width smaller than the ones shown on Figures 3 and 8.

As shown on Figure 17.1 , the cut of the bottom of the cup 17b of part 17a is done using the puncture V with the matrix W. On the following operation, the part 17a will go through the conformation process by the first conic section of the puncture X, matrix Z and counter puncture/extractor AA, originating the finished part 18. The finished part 18 can be obtained, alternatively, cutting, enlarging and doing the finishing of the hole in a single operation using a puncture BB, matrix CC and counter puncture/extractor DD, whe-

re the puncture BB has a first perforation section 40, an intermediary enlargement section 41 and a later finishing section 42.

On a second variation of the process object of this invention illustrated on Figures 19 to 23, Figure 19 shows the cylinder or blank 19 that re- fers to the new process, which has smaller dimensions than the cylinder shown on Figure 10, after cutting the metallic bar, and which will soon be pressed forming the flat disk 20, according to Figure 20.

Figure 21.1 shows the disk conformation step, which the cup 21 is obtained through the puncture EE together with the matrix FF and the counter puncture/extractor GG, making another "male-female" set. It is observed in this phase that two non-passing recesses 212 and 213 are done which are opposed one to another, and the bottom of said recesses have their central area destined to further cut and with smaller widths than the o- nes shown on Figure 12. As shown on Figure 22.1 , in this step the cut of the bottom of the cup 22b of the part 22a is done using the puncture HH with matrix II. On the next operation, the part 22a will go through the conformation process by the conic first section of the puncture JJ, matrix KK and counter puncture/extractor LL, resulting on the finished part 23. Preferably but not mandatorily, steps (iv) and (v) can be sequentially performed on the same operation. That means that, preferably, the cut, the enlargement and the finishing of the hole are performed on a single operation using a puncture MM, matrix NN and counter puncture/extractor OO, where the puncture MM has a first perforation section 50, an intermediary enlargement section 51 and a last finishing section 52.

It is important to notice that Figures 14 to 18 refer to the manufacture of an inner bearing ring which has an outer flange, while Figures 19 to 23 refer to the manufacture of a bushing, both with the process object of this invention, and which are simple non-limiting examples of some among seve- ral types of pieces that can be manufactured with less natural waste of raw material.

It is possible to make hollow conic parts with any outer embodi-

merit through the forging process object of this invention and with any type of passing inner embodiment, such as cylindrical, truncated conic, truncated pyramidal or any other embodiment, according to conveniences or needs of the project. The pre-formation step of the part happens according a series of studies of the material used and the geometry of the final part, among them, the outflow limit of the part, the puncture force applied to deform the material, the form it is obtained, among others. This study allows learning precisely how the material will behave during the pre-formation step, how its deforma- tion will happen and the outflow within the puncturing matrix, and, consequently, how the cut area of the bottom of the cup (diameter, width, position) will be, being possible to dimension it so it is the biggest (biggest amount of material and biggest weight) or the smallest (minus the weight) possible, which clearly is the most interesting in most situations. By studying the material outflow during the forging process (deformations, outflow and rupture limits, etc. due to the features and the temperature where the process happens) combined with blank 14,19 dimensions (volume) and mass optimizations, it is possible to obtain a final part wasting less punctured material, and such waste is reduced in about 85%. It is an innovative optimization, not known on the market. The blank 14,19 can be optimized to have an initial smaller mass when compared to known manufacture processes, once it was object of such studies.

In other words, the consequent shred 17b,22b has smaller sizes and mass, which gives the manufacturer a reduction of the material wasted providing a series of obvious advantages.

Therefore, a final part, identical to the one obtained by the process already know, can be obtained through a blank that has smaller dimensions and smaller mass. Regarding energetic issues, a smaller mass means smaller use of energy that is necessary for an eventual heating of the blank 14,19 when hot or warm forging, with reduction on the manufacture cost due to the reduction on the consumption of energetic resources.

It is obvious that the study of the material used and the geometry

of the final part, among them the puncture power used to deform the material, the form to be obtained, among others, has to be done so each type of part to be forged and the final results will vary enormously due to the size/geometry/width of the part and the material which is manufactured. But, on the essence, all and any part object of this study will have, as its intrinsic feature, the fact that it can be obtained by a blank whose mass and measures are reduced when compared to the same part obtained by the conventional process, where there is no optimization.

Illustratively, below there are some examples of inner ring of an angular contact bearing made by the conventional forging process and an example of an analogous ring obtained by the process object of this invention. Table 1

It is clear, by table 1 , that to manufacture the same part, the process object of this invention enables a blank 14,19 reduction of 34 grams in 148 grams, which causes a mass reduction of almost 23%.

Table 2 below shows a percentage comparison of material economy enabled by the process object of this invention for the manufacture of the same part. Table 2

Illustratively, there is also an example of bushing made by the conventional forging process and an example of analogous bushing obtained by the process object of this invention.

Table 3

It is clear, on table 3, that to manufacture the same part, the process object of this invention enables a reduction of 20 grams in 130 grams on the blank 14,19, which provides a mass reduction of almost 15% in this e- xample.

Table 4 below shows a percentage comparison of the material economy that the process object of the invention herein enables to manufacture the same part. Table 4

Figures 16 and 21 show the schematic visualization of the geometry change of the pre-formed part,

And it is important to point out that the great mass reduction of the shred does not cause an increase on its manufacture cost, once the machinery does not need to be changed and slightly changed tools shall be cre- ated.

The puncture - placed on the upper plaque - movable tool which is responsible for drilling and cutting the inner part of the piece to be forged, that is, it is responsible for the embodiment of the passing opening, it should have a cone or trunk shape, pyramid, trunk of pyramid or another shape, in such a way that, clearly, the passing opening is properly conformed.

According to Figures 18.2 and 23.2, the puncture can also perform three sequential tasks on the same operation: cutting the bottom of the cup, enlarging the hole and forming the final part. Therefore, its edge has a

convenient shape to do the perforation, its intermediary section is conic, truncated conic or similar to enlarge the hole and its later section has the same shape than the inside of the final part, to be able to do the inner finishing. Such puncture embodiment allows all the steps, from the perforation to the formation of the final part in a single operation, optimizing time to perform the last two steps of the forging process.

The puncture cooperates with a respective matrix - placed on the base plaque - fixed tool, and said matrix is built in such a way to limit the deformation of the punctured metallic part (enabling a targeted outflow of the material) during such forging process forming a "male-female" set. In other words, the matrix corresponds to the "mold" of the outer section of the punctured part.

On the other hand, the tool has a movable section called counter puncture/extractor (shown on Figures 3.1 , 4.1 , 5.1 , 8.1 , 9.1 , 12.1 , 13.1 , 16.1 , 18.1 , 18.2, 21.1 , 23.1 and 23.2), whose task is to absorb the impact of the puncture and extract the part from inside the matrix each time it is submitted to a puncture operation, once said part is housed on it after each time it is punctured.

Clearly, the shape of the puncture is co-operative with one of the matrix so, when the puncture happens, the raw material is conformed so material waste is minimized and the final part maintains the correct dimensions for its operation. Shape and dimensions of puncture and matrix are determined by the shape and the pre-form wants to reach, according to optimization calculations, which have already been mentioned. Preferably, and as already mentioned above, instead the formation steps of the cup and cut of the bottom of the cup which happen on the final phase of conventional processes, a pre-formation step of the part is preferably done where the bottom of the cup is done before the final formation of the part is done, obtaining, together with the shape granted to such pre-form, an economy on the waste of material to be discarded during the process.

Once preferable embodiment examples have already been described, it shall be understood that the scope of this invention encompasses

other possible variations, being limited only by the content of the claims attached, including the possible equivalents.