WO2024224307A1 - Method of forming objects using a transfer press - Google Patents

Abstract

The invention concerns a method of forming objects, the method being performed by using a transfer press, wherein the aforesaid method comprises at least the following steps: - feeding to a transfer press a plurality of semi-finished products to be formed, wherein the aforesaid transfer press is provided with at least two work stations, wherein the aforesaid two work stations are arranged along respective transfer directions (D1, D2) of the semi-finished products, and wherein each of the aforesaid work stations comprises forming elements; characterized in that the feeding of the aforesaid semi-finished products to the aforesaid transfer press is performed centrally with respect to a meeting point of the aforesaid transfer directions (D1, D2) and the aforesaid semi-finished products are fed to the press so as to be subdivided along the aforesaid transfer directions (D1, D2), the aforesaid transfer directions (D1, D2 ) being divergent from each other and lying on same straight line (B-B).

Description

"METHOD OF FORMING OBJECTS USING A TRANSFER PRESS"

FIELD OF THE INVENTION

The present invention concerns a method of forming objects, the method being performed by using a transfer press.

KNOWN ART

Transfer presses, i.e. presses provided with one or more work stations arranged along a transfer direction of the semi-finished products and each comprising respective pressing elements, are known .

In such presses, a step-by-step transfer of the semi-finished products is performed along the transfer direction so that the semi-finished products subsequently meet the work stations provided on the press.

In particular, in transfer presses, the semi-finished product is transported from a station of the work process to the subsequent one by means of a member synchronized with the action of the press (also named transfer) on which holding tools, which carry out the step-by-step transport work together with the synchronized member, are fixed.

The transfer process is essentially used for two reasons.

The first reason is that such process allows saving of material, since no additional material is needed for transporting the piece, the transport of the piece being entrusted to the transfer itself. The second reason is that some pieces can only be made with transfer presses, since there is no way for them to be connected in the various operations, as is the case, for example, for pieces molded from wire instead of strip, such as screws and bolts or other. The section of the wire in question can be round, hexagonal or of any shape that can be manufactured and made with any process, such as drawing, extrusion, hot and cold forming.

Usually, in all molding processes, the initial material enters raw from only one side of the press, for example from its left side, and the finished pieces come out of the opposite side of the press, for example, the right side. In the vast majority of cases, this results in the load of the mold under the press not being perfectly balanced with respect to the press thrust center of gravity.

Generally, but indeed not always necessarily, initial processing phases, with respect to the path of the semi-finished products inside the transfer press, involve greater stress than final ones. In any case, the stress of a given processing phase is not the only factor that determines this imbalance but also the position of said processing phase along the travel path of the press.

Considering the processing phases, the differences in height of these phases, the spring elements necessary to carry out such processing as well as other factors, the result of the forces that the press has to withstand or provide is certainly and anyhow always unbalanced.

KR 2008-0088048 A, in the name of Korea Electric Terminal Co. Ltd., describes a transfer process for making spring portions, which comprises two work stations which are arranged along respective transfer directions parallel to each other.

US 2008/307628 Al, in the name of Yrjola Tomi, describes a piece of equipment for assembling two complex components into a single finished product, wherein the two complex components are made in respective work stations arranged along transfer directions which are aligned with each other and which bring the respective complex components to converge towards a central device for assembling the finished product.

US 2021/135245 Al, in the name of Cisar Rolf, concerns a transfer press comprising two work stations which are arranged along respective transfer directions of the semi-finished products and which are aligned and convergent in a central area. The semifinished products are fed to each work station at the opposite end of the aforesaid central area and are unloaded at the latter.

An aim of the present invention is thus to implement a method of forming objects by using a transfer press which prevents the imbalance of the press.

A further aim of the present invention is to implement a method of forming objects by using a transfer press which improves the performance achievable with conventional transfer presses.

Last but not least, aim of the invention is to achieve the aforementioned results in a practical and economic way. SUMMARY OF THE INVENTION

The above aims are achieved thanks to a method of forming objects, which is performed by using a transfer press, wherein the aforesaid method comprises at least the following steps:

- feeding to a transfer press a plurality of semi-finished products to be formed, wherein the aforesaid transfer press is provided with at least two work stations, wherein the aforesaid two work stations are arranged along respective transfer directions of the semi-finished products, and wherein each of the aforesaid work stations comprises forming elements; characterized in that the feeding of the aforesaid semifinished products to the aforesaid transfer press is performed centrally with respect to a meeting point of the aforesaid transfer directions and the aforesaid semi-finished products are fed to the press so as to be subdivided along the aforesaid transfer directions, the aforesaid transfer directions (DI, D2 ) being divergent from each other and lying on the same straight line (B- B) .

An advantage of the present invention is that, thanks to the method of the present invention and in particular thanks to the fact that the transfer directions, i.e. feeding directions to the press, are aligned and opposite to each other, all the forces are perfectly and symmetrically balanced at each point of the travel path.

This fact safeguards both the members of the press, which benefit from a longer service life, and the mold which, working in a balanced way, does not wear due to imbalance.

A further, although not less important advantage of the invention, is that the method of the invention allows the transfer step to be halved, which is normally used for two-impression transfer processes with a double step.

In fact, one of the speed limits of transfers is precisely given by the travel path of the transfer.

In the present case, a possible increase in speed is achieved in the case of two-figure molds in line, because instead of having a double step line advancing we start from the center and make a step to the right and one to the left.

Still, an advantage of the present invention is to make more efficient the feeding of the semi-finished products simplifying it, thanks to the fact that such semi-finished products come from a central meeting point of the respective transfer directions, allowing efficient and simple synchronization of the processing phases, in addition to simplification of the feeding devices of the semi-finished products.

The invention further comprises a transfer press configured for performing the method of the invention.

The transfer press comprises at least two work stations, each of the work stations being arranged along respective transfer directions of the semi-finished products, wherein the press further comprises a loading station for the aforesaid semifinished products, placed in a central position with respect to a meeting point of the aforesaid transfer directions, and wherein the loading station of the semi-finished products is configured so as to subdivide the semi-finished products fed to it along the respective transfer directions, the aforesaid transfer directions being divergent from each other and lying on the same straight line .

Preferably, the at least two work stations, each arranged along respective transfer directions of the semi-finished products, are operated by a single drive unit.

Further characteristics of the invention can be deduced from the dependent claims.

BRIEF DESCRIPTION OF THE FIGURES

Further characteristics and advantages of the invention will become clear from the reading of the following description provided by way of example and without limitations, with the aid of the figures depicted in the accompanying drawings, in which: figure 1 is a schematic front view which illustrates the operation of the method according to an embodiment of the present invention;

- figure 2 is a schematic plan view which illustrates the operation of the method, wherein the semi-finished are inserted frontally into the trans fer press in a symmetric way from two opposite directions ;

- figure 3 is a schematic plan view which illustrates the operation of the method, wherein the semi- finished products are inserted frontally into the press in a symmetric way and in pairs from two opposite directions , starting from a strip to be punched;

- figure 4 is a schematic plan view which illustrates the operation of the method, wherein the semi- finished products are inserted frontally into the press in a symmetric way from opposite directions , to provide four simultaneous processing lines ;

- figure 5 is a schematic plan view which illustrates the operation of the method, wherein the semi- finished products are inserted frontally from opposite directions , starting from a strip to be punched, to provide four simultaneous processing lines ;

- figure 6 is a schematic plan view which illustrates the operation of the method, wherein the semi- finished products are inserted frontally into the press in a symmetric way from opposite directions , to provide six simultaneous processing lines ; and

- figure 7 is a schematic plan view which illustrates the operation of the method, wherein the semi- finished products are inserted frontally from opposite directions , starting from a strip to be punched, to provide six simultaneous processing lines .

DETAILED DESCRIPTION OF THE FIGURES

The invention wi ll now be described with particular reference to the accompanying figures , wherein a schematic front view which illustrates the operation of the method according to an embodiment of present invention is depicted in figure 1 , said method being implemented by using a trans fer press globally denoted by the numerical reference 10 .

The press 10 comprises a pressure element 12 which carries a plurality of molds 16 , each defining a work station, and which counteracts a fixed element 14 .

In the speci fic case depicted in the accompanying figures , the work stations are eight in number, but other configurations with di f ferent numbers of work stations can also be implemented without thereby departing from the scope of the invention .

For example , in alternative embodiments of the invention, only two work stations may be provided .

In this case , the two work stations are arranged along respective trans fer directions DI , D2 of the semi- finished products and each of the work stations comprises forming elements .

Still in this case , the feeding of the semi- finished products to the trans fer press is performed centrally with respect to a meeting point of the aforesaid trans fer directions and the semi- finished products are fed to the press so as to be subdivided along the trans fer directions DI , D2 , the trans fer directions DI , D2 being divergent from each other .

In any case , the configuration provided by the press 10 is not binding for the inventive concept of the invention, as better clari fied in the following of the present description .

Each of the molds 16 performs a particular processing on the respective semi- finished product .

In particular, it should be noted that a deep-drawing sequence has been depicted in figure 1 to facilitate the understanding of the invention, however the inventive concept of the present invention is not limited to deep-drawing processes but can also generally be extended to any molding process or processing in general .

In the example of figure 1 , the trans fer press 10 provides a couple of travel paths for the semi- finished products 20 , wherein the feeding of the aforesaid semi- finished products to the aforesaid press 10 is performed along two opposite directions DI , D2 .

Since it is a trans fer press , figure 1 also shows the indication of the step P that the semi- finished products 20 follow .

Figure 1 also shows a graph 100 which illustrates the magnitude of stresses acting on the press itself depending on the distance from a plane A-A perpendicular to the press 10 itsel f and passing through the center of the press 10 .

It should be noted that , thanks to the particular shape of the trans fer press according to the present invention, the stresses of the press itsel f travel symmetrically with respect to the plane A- A.

With this configuration, the problem regarding the imbalance of stresses in trans fer presses is thus eliminated .

Generally, the trans fer press 10 is configured to perform the method of the invention .

The trans fer press comprises at least two rows of work stations , each row of work stations being arranged along respective trans fer directions ( DI , D2 ) of the semi- finished products .

Preferably, the at least two rows of work stations arranged along the respective trans fer directions DI , D2 are operated by a single drive unit .

In this embodiment , when the respective transfer directions DI , D2 lay on the same straight line B-B, the preferred use of a single drive unit for operating the at least two rows of work stations allows optimal balancing of dynamic loads to be achieved .

The press further comprises a loading station to load the aforesaid semi- finished products , which is placed in a central position with respect to a meeting point of the aforesaid trans fer directions . Figure 2 is a schematic plan view of the press 10 , which illustrates the operation of the method in which the semi- finished products are inserted frontally into the trans fer press in a symmetric way .

In particular, the feeding of the semi- finished products 20 to the trans fer press 10 is performed centrally with respect to a longitudinal axis B-B of the press , so that the aforesaid semifinished products are fed to the press 10 along at least two directions DI , D2 divergent from each other .

In particular, a group of semi- finished products 20 subdivided in pairs , is fed frontally with respect to the press and, subsequently, the feeding of the semi- finished products 20 to the press 10 is performed along two opposite directions DI , D2 .

In the non-limiting example illustrated in figure 2 , the first station 1 , along each of the at least two opposite directions DI , D2 , performs a first processing by cutting the semi- finished products 20 which, in this case , assume a cup-like shape and which, from the second station 2 up to station 8 , undergo progressive deep-drawing processing which progressively reduce the diameter of the cup by increasing the height of the cup while maintaining a closed bottom .

According to another aspect , the f irst station 1 along each of the two opposite directions DI , D2 can be fed by a strip portion from which to punch the semi- finished products 20 by plastic deformation or cutting processes to be performed in the subsequent stations in each of the two directions DI , D2 .

The semi- finished products could have previously undergone , when still transported by the strip itsel f and not yet by the trans fer, possible processing according to known technologies of progressive molding . According to another aspect , the first station 1 can be fed, along each of the two opposite directions DI , D2 , by a portion of wire with round or shaped section from which to form the semifinished products 20 for the plastic deformation or cutting processes to be performed in the subsequent stations in each of the two directions DI , D2 .

According to another aspect , the f irst station 1 can be fed, along each of the two opposite directions DI , D2 , of a semi- finished product achieved with any type of previous processing : by hot or cold molding, by chip removal , sintered, by casting, or other process , consisting in the semi- finished products 20 for the plastic deformation or cutting processes to be performed in the subsequent stations in each of the two directions DI , D2 .

According to a further aspect , the final work station, such as for example station 8 , can include processes for edge bending or flanging of semi- finished products 20 .

Figure 3 is a schematic plan view which illustrates a variant of the operation of the method, wherein the semi- finished products 20 are inserted frontally and in pairs into the press 10 in a symmetric way, starting from a strip 50 to be punched .

Also in this case , the feeding of the semi- finished products 20 to the press 10 is performed along two opposite directions DI , D2 .

The plan view of figure 3 further illustrates that the trans fer mechanism of the press 10 is reali zed by the presence of two opposing bars 30 and 32 which cooperate by using appropriate holding elements for the trans fer of the pieces .

This fact does not exclude that , in alternative embodiments of the invention, the trans fer mechanism can also be made of a single bar, wherein the bar is present only on one side of the press 10 , and the holding of the semi- finished products 20 can be achieved with only one holding element which can be of the pneumatic or spring type , or made in another known way .

Figure 4 is a schematic plan view of an alternative embodiment of the trans fer press globally indicated by the numerical reference 10 ' .

Another variant of the operation of the method is illustrated in such figure , wherein the semi- finished products are inserted frontally into the press 10 ' in a symmetric way, to provide four simultaneous processing lines .

Figure 5 is a schematic plan view which illustrates a further operation of the method which is di f ferent from the example of figure 4 in that the semi- finished products 20 are inserted frontally, starting from a strip 50 to be punched, to provide , also in this case , four simultaneous processing lines .

Also in the embodiments of figures 4 and 5 , the general concept of the present invention is adhered to , i . e . the feeding of the semifinished products 20 to the press 10 ' is performed along two opposite directions DI , D2 , whereas the press itsel f is configured to provide four simultaneous processing lines , as set forth previously .

Figure 6 is a schematic plan view which illustrates a further embodiment of the trans fer press of the invention, globally indicated by the numerical reference 10 ' ’ . In this case , the operation of the method requires the semifinished products 20 to be inserted frontally into the press 10 ' in a symmetric way, to provide six simultaneous processing lines . Finally, figure 7 is a schematic plan view which illustrates a further operation of the method which is di f ferent from the example of figure 6 in that the semi- finished products 20 are inserted frontally into the press 10 ' ’ , starting from a strip 50 to be punched, provide , also in this case , six simultaneous processing lines .

Also in the embodiments of figures 6 and 7 , the general concept of the present invention is adhered to , i . e . the feeding of the semifinished products 20 to the press 10 ' ’ is performed along two opposite directions , whereas the press itsel f i s configured to provide six simultaneous processing lines , as set forth previously .

In the embodiment described of the invention, re ference was made to cylinder-shaped semi- finished products , however the inventive concept is not limited to cylindrical pieces only but can be extended to pieces to be processed of any shape and si ze . Obviously, the inventive concept is not limited to mechanical presses only but to presses of any type (hydraulic, pneumatic, electric ) , wherein press can be identi fied as any machine tool which has a fixed part and a movable thrust plane which performs a given travel path .

The presses can have any processing direction, vertical , hori zontal , with a thrust from above , with a thrust from below, without thereby departing from the inventive concept described in the present invention .

At the same time, the inventive concept is valid for any type of trans fer, whether mechanically, pneumatically, electrically actuated or any other .

As set forth previously, the inventive concept is valid both whether feeding is performed by a strip, or with flat profiling, or with already pre-deep-drawn pieces , or with pieces formed from round or shaped wire , or with pieces formed from any other previous processing .

Flat profiling means a process in which the first step, metal sheet cutting, is done with a process di f ferent from the previous one . The pre-molded strips with graphics are a possible example . Instead, in the case of pre-deep-drawn pieces , what is meant is processes in which the first two steps , the metal sheet cutting and the first deep-drawing, are done with a process di f ferent from the previous one , for example when the piece requires intermediate annealing . The invention as described can be modi fied or improved for contingent or particular reasons , without thereby departing from the obj ect of the invention .

Claims

1. A method of forming objects using a transfer press, wherein the aforesaid method comprises at least the following steps:

- feeding to a transfer press a plurality of semi-finished products to be formed, wherein the aforesaid transfer press is provided with at least two work stations, wherein the aforesaid two work stations are arranged along respective transfer directions (DI, D2 ) of the semi-finished products, and wherein each of the aforesaid work stations comprises forming elements; characterized in that the feeding of the aforesaid semifinished products to the aforesaid transfer press is performed centrally with respect to a meeting point of the aforesaid transfer directions (DI, D2 ) and the aforesaid semi-finished products are fed to the press so as to be subdivided along the aforesaid transfer directions (DI, D2 ) , the aforesaid transfer directions (DI, D2 ) being divergent from each other and lying on the same straight line (B-B) .

2. Method according to claim 1, characterized in that the aforesaid semi-finished products are fed to the press, coming from a direction perpendicular to the straight line (B-B) .

3. Method according to claim 2, characterized in that the aforesaid semi-finished products are fed to the press from a strip to be punched .

4. Method according to any one of the preceding claims, characterized in that the aforesaid semi-finished products are fed to the press so that a plurality of simultaneous processing can be performed along respective different processing directions (DI, D2) .

5. Method according to any one of the preceding claims, characterized in that the aforesaid transfer press is provided with a plurality of work stations arranged along respective transfer directions (DI, D2 ) of the semi-finished products and each comprising forming elements, wherein the aforesaid method provides that the feeding of the aforesaid semi-finished products to the press is performed centrally with respect to a meeting point of the aforesaid transfer directions (DI, D2 ) and that said semifinished products are fed to the press so as to be subdivided along the aforesaid transfer directions (DI, D2 ) , and wherein the aforesaid method provides a step-by-step transfer phase of the semi-finished products along the respective transfer direction (DI, D2 ) , so that the semi-finished products subsequently meet the work stations assigned to them.

6. A transfer press configured to perform the method according to the preceding claims, characterized in that the aforesaid transfer press comprises at least two work stations, each of the aforesaid work stations being arranged along respective transfer directions (DI, D2 ) of the semi-finished products, wherein the press further comprises a loading station for the aforesaid semi-finished products, which is positioned in a central position with respect to a meeting point of the aforesaid transfer directions (DI, D2 ) , and wherein the loading station of the semi-finished products is configured so as to subdivide the semi-finished products fed to it along respective transfer directions (DI, D2 ) , the aforesaid transfer directions (D1,D2) being divergent from each other and lying on the same straight line (B-B) .

7. Transfer press according to claim 6, characterized in that the aforesaid transfer press comprises at least two rows of work stations each provided with a plurality of work stations, each of the aforesaid rows of work stations being arranged along respective transfer directions (DI, D2 ) of the semi-finished products, wherein the aforesaid press further comprises a loading station of the aforesaid semi-finished products, which is placed in a central position with respect to a meeting point of the aforesaid transfer directions (DI, D2 ) and configured to feed the semi-finished products to the press so as to subdivide them along the aforesaid transfer directions (DI, D2 ) , the aforesaid transfer directions (DI, D2 ) being divergent from each other.