Device for shearing dies for sheets for electrical use

Abstract

An apparatus (10, 10 ') for a shearing die for sheets for electrical use, the function of which is to form a layered stack for electrical use in electrical machines such as motors, generators, transformers, counters, ignition coils and similar electrical devices, comprises a box-shaped body (12, 30), the box-like body is housed inside the plate (14) of the shearing die and comprises means for simultaneously or selectively activating / deactivating the shearing punches (15) of said shearing die in the shearing step, the number of activating / deactivating means corresponding to the number and position of said punches (15).

Description

[0001] The present invention relates to an arrangement for shearing dies for sheet material for electrical applications.

[0002] More specifically, the present invention relates to an apparatus for use in shear dies for manufacturing metal sheets for forming layered stacks for electrical use in electric machines such as motors, generators, transformers, counters, ignition coils and similar electrical equipment.

[0003] As is known, the magnetic sheets required for forming the layered stack are obtained starting from metal sheets subjected to a shearing operation with the aid of a special die, which for this purpose comprises elements defined in the jargon as "special functions", namely mechanical elements of the die, either manually or by means of a pneumatic or hydraulic piston, which enable / disable one or more shearing elements of the die.

[0004] An example of a "special function portion" is a stack of sheets manufactured in a progressive die, in which the superimposed sheets are each provided with a protruding support member, the protruding support member defining a cavity at an opposite surface (relative to the surface of the support member), and in which the support member of the sheet is constrained in the cavity of an adjacent sheet, and another sheet is inserted between the two adjacent sheets constrained together, and the other sheet is provided with a through opening suitable for being passed through by the support member of the sheet, and the support member of the sheet is connected to the cavity of the adjacent sheet; in this case, the special function portion is activated and deactivated at each extrusion stroke.

[0005] In a progressive die such as that described above for a specific stacking solution, there may be a plurality of "special functional parts", and by activating / deactivating these functional parts, the shear punch may be activated or deactivated, and thereby shear products (e.g., sheets) having a plurality of geometries or shapes may be obtained.

[0006] Usually, the activation / deactivation of the above functional parts takes place with the help of special equipment, which is placed in the mechanical structure of the shearing die and includes a moving rod, a slide and its receiving plate, which require a considerable space and are driven by an external control and command unit with the help of pneumatic or hydraulic pulses.

[0007] Conventional devices therefore have significant disadvantages presented by the considerable size and weight of the devices.

[0008] Known solutions of this type are described in US Pat. No. 4,623,089 or US Pat. No. 5,144,872 or US Pat. No. 8,770,077, which describe shearing dies that feature a complex mechanical structure with considerable size and weight.

[0009] Another disadvantage of conventional devices is that they are only able to activate the shear punches simultaneously in each shearing step.

[0010] Another disadvantage of the devices of the traditional type is presented by mechanical problems defined by breakage and jamming of the mechanism used to initiate / transmit the movement to the shear punch.

[0011] Known solutions with these types of disadvantages are described in EP0963802 or DE202005010990 or EP3789133 or DE4135787 or US5771565, which relate to shearing devices comprising a plurality of punches whose movement is activated / deactivated according to the shearing demand with a piston or lever type mechanism.

[0012] Another disadvantage and a consequence of the above disadvantages is the cost of maintaining, replacing, repairing damaged or stuck mechanisms, which affects production costs.

[0013] The object of the present invention is to overcome the above-mentioned disadvantages.

[0014] More specifically, an object of the present invention is to provide a device for a shearing die for electrical use which has limited dimensions and which allows it to be easily installed inside the shearing die.

[0015] Another object of the present invention is to provide a device which reduces, if not significantly reduces, the likelihood of witnessing any breakage and / or jamming of the mechanism used to transmit motion to the shear punch.

[0016] Another object of the present invention is to provide a device for a shearing die that allows the shearing punches to be activated simultaneously or selectively / individually within the same shearing step.

[0017] Another object of the present invention is to provide a device for shearing dies that is easy to manage in terms of maintenance or repair or replacement interventions, while controlling the related costs.

[0018] Another object of the invention is to provide the user with a device for shearing dies for electrical use which is suitable for ensuring high reliability and high impedance over time and which is suitable for easy and economical manufacture.

[0019] These and other objects are achieved by the invention having the features according to claim 1 .

[0020] According to the present invention, there is provided a device for a shearing die for a sheet material for electrical use, the function of the sheet material for electrical use being to form a layered stack, the layered stack being used for electrical use in electric machines such as motors, generators, transformers, counters, ignition coils and similar electrical equipment, the device comprising a box-shaped body accommodated inside a plate of the shearing die, and comprising a device for simultaneously or selectively starting / deactivating the shearing punches of the shearing die during a shearing step, the number of the starting / deactivating devices corresponding to the number and position of the punches.

[0021] Advantageous embodiments of the invention are presented by the dependent claims.

[0022] The structural and functional characteristics of the device for shearing dies for sheets for electrical use of the present invention will be better understood from the following detailed description, with reference to the accompanying drawings illustrating embodiments provided only as non-limiting examples, in which:

[0023] Figure 1 Schematically illustrates an axonometric view of an apparatus for shearing dies for sheets for electrical use according to the present invention;

[0024] Figure 2 Schematically illustrates a view of the device of the invention in a cross section according to a vertical plane;

[0025] Figure 3 and Figure 4 Schematically illustrates a cross-sectional view of the device of the invention according to a vertical plane, wherein each figure illustrates a movement sequence of the device of the invention;

[0026] Figure 5 Schematically illustrates the alternative Figures 1 to 4 an axonometric view of the device of the invention in accordance with the embodiment mentioned in the embodiment;

[0027] Figure 6 and Figure 7 Schematically illustrates Figure 5 1 and 2. A view of a device according to the invention in cross section according to a vertical plane, wherein each figure illustrates a movement sequence of the device according to the invention.

[0028] Referring to the above drawings, Figure 1 as well as Figures 2 to 4 The device for cutting dies for sheets for electrical use of the present invention, generally indicated by 10, comprises a plate 14 ( Figure 2) inside a box-shaped body 12, the shearing die comprising a shearing punch 15 and an abutment spacer 16 for the shearing punch, the abutment spacer 16 being for the purpose of activating / deactivating a specific shearing function (referred to as a "special function") and being used to move according to a mode better described below according to the advancement / retraction direction of the shearing punch.

[0029] The spacer means 16 comprises an elastic element 16 ′ cooperating with said spacer means and serving for elastic return of the activated / deactivated shear punch 15 as described below.

[0030] The spacer device 16 and therefore the shear punch 15 are activated / deactivated in their movement by means of an operating element arranged in the box-like body 12 .

[0031] The box-like body 12 comprises an upper block 12 ′ and a lower block 12 ″ which are airtightly and rigidly constrained to each other by means of known type of retaining means such as screws or the like.

[0032] The lower block 12″ has through holes or through openings 12B, which are formed in the thickness of its base and are used to accommodate a part of the spacer 16, to which the shear punches 15 are connected; the number and arrangement of the through holes or through openings 12B correspond to the number and position of the shear punches 15.

[0033] The device for activating / deactivating the shear punch 15 is arranged in the lower block 12", and the device for activating / deactivating the shear punch 15 comprises a slide 18 that can be moved in translation in a dedicated seat 19 formed in the lower block 12", wherein the slide 18 cooperates with an elastic element 20 that is also accommodated in the seat 19 and is preferably defined by a compression spring.

[0034] In the preferred embodiment mentioned in the accompanying drawings, the slide 18 comprises a head portion 18' and a tail portion 18" (oriented in the direction of the elastic element 20), the head portion 18' and the tail portion 18" having different height dimensions, and in particular wherein the height of the tail portion 18" is lower relative to the height of the head portion 18'.

[0035] The number of slides 18 and therefore the number of elastic elements 20 and the associated housings 19 corresponds to the number of shearing punches 15 that have to be activated / deactivated in the desired shearing step.

[0036] In the preferred embodiment mentioned in the drawings, the slide 18 is arranged according to a radial direction, with a forward / backward sliding movement relative to the center of the lower block 12 ″.

[0037] According to alternatives to the above-described embodiments, the slide 18 can be arranged according to a different geometry relative to the radial geometry and this depends on the specific production requirements.

[0038] The sliding movement of the slider 18 in the seat 19 occurs by means of a compressed air flow, which is fed by a fitting 22 fixed to the box-like body 12 and distributed in the aforementioned seat 19 by means of a distributor assembly 24 also arranged inside the box-like body 12 at the center of the box-like body 12.

[0039] Refer to the following Figures 1 to 4 The operation of the device for shearing dies for electrical sheets of the present invention described in detail above with reference to its structural features is explained with reference to the embodiments mentioned in the accompanying drawings.

[0040] Reference Figure 2 and Figure 3 , illustrates a state in which the shear punch 15 is deactivated and no shearing is performed during the shearing stroke.

[0041] In this state, the slide 18 is in a rest end-stroke position in the corresponding seat 19 at the center of the lower block 12″ of the box-like body 12 and is held in such a position by the action of the elastic element 20 with the spacer 16 and thus with the shear punch 15, which rises in the thickness of the die plate 14 and the lower block 12″ of the box-like body 12 (as shown in FIG. Figure 3 ), thereby abutting the tail portion 18 ″ of the slide 18 and causing a non-shearing action on the sheet (particularly, the spacer 16 engages with the tail portion 18 ″ of the slide 18 ).

[0042] Reference Figure 4 , which illustrates the state in which the shear punch 15 is activated and performs shearing during the shearing stroke.

[0043] To activate the shear punch 15, compressed air is fed to the box-like body 12 through the fitting 22 and distributed to each slide 18 through the distributor assembly 24, and due to the action of the air, the slide 18 slides radially away from the center of the lower block 12", thereby compressing the elastic means 20 (such as by Figure 4 By this sliding movement, the slide 18 closes the through hole or through opening 12B of the lower block 12", in which the spacer 16 partially slides (the spacer contacts the head portion 18' of the slide 18), and the shear punch 15 enters the die of the shearing die and shears the large sheet to produce the sheet.

[0044] Then, when the shear punch 15 is not allowed to shear during the subsequent shear stroke, the supply of compressed air to the box-like body is stopped and, due to the action of the elastic means 20, each slide 18 returns to the rest position at the center of the lower block 12″ and the device returns to Figure 2 or Figure 3 The status mentioned in .

[0045] Reference Figures 1 to 4 In the embodiment, when compressed air is fed to the box-shaped body 12, the slide 18 is simultaneously slidably driven by simultaneously activating the shear punches 15.

[0046] Reference Figures 5 to 7 , illustrates an alternative embodiment of the device of the invention, indicated generally at 10 ′, according to which the shear punch can be selectively activated / deactivated.

[0047] In the description of the alternative embodiment, the Figures 1 to 4 The same reference numerals throughout the embodiments mentioned herein are used to denote similar components.

[0048] The device 10 ′ comprises a box-like body 30 including an upper block 30 ′ and a lower block 30 ″ which are constrained to each other airtightly and rigidly by retaining means of known type such as screws or the like.

[0049] The lower block 30″ has a through hole or through opening 30B, which is formed in the thickness of its base and is used to accommodate a part of the spacer 16, to which the shear punch 15 is connected; the number and arrangement of the through holes or through openings 12B correspond to the number and position of the shear punches 15.

[0050] The device for activating / deactivating the shear punch 15 is arranged in the lower block 30", and the device for activating / deactivating the shear punch 15 includes a slide 34 that can be translated in a dedicated seat 36 formed in the lower block 30", wherein the slide 34 cooperates with an elastic element 35 that is also accommodated in the seat 36 and is preferably defined by a compression spring.

[0051] In the embodiment mentioned in the accompanying drawings, the slide 34 comprises a head portion 34' and a tail portion 34" (oriented in the direction of the elastic element 35 and in the direction of the center of the lower block 30" of the box-shaped body 30), the head portion 34' and the tail portion 34" having different height dimensions, and in particular wherein the height of the tail portion 34" is lower relative to the height of the head portion 34'.

[0052] The number of slides 34 and therefore the number of elastic elements 35 and the associated housing seats 36 corresponds to the number of shearing punches 15 that have to be activated / deactivated in the desired shearing step.

[0053] In the embodiment mentioned in the drawings, the slide 34 is arranged according to a radial direction, with a forward / backward sliding movement relative to the center of the lower block 30 ″.

[0054] According to alternatives to the embodiment described, the slide 34 can have a different geometrical arrangement depending on the specific production requirements (depending on the configuration of the shear punch to be activated / deactivated).

[0055] The sliding movement of the slides 34 in the seats 36 takes place by means of a compressed air flow fed by a fitting 38 fixed to the box-like body 30 at each slide 34 and distributed in the seat 36 of each slide 34 .

[0056] Refer to the following Figures 5 to 7 The operation of the device for shearing dies for electrical sheets of the present invention described in detail above with reference to its structural features is explained with reference to the embodiments mentioned in the accompanying drawings.

[0057] Reference Figure 6 , illustrates a state in which the shear punch 15 is deactivated and no shearing is performed during the shearing stroke.

[0058] Reference Figure 7 , illustrates the following state: in a single shearing stroke of the die, not all shearing punches 15 are activated simultaneously, but are selectively activated by the accessory 38 that only feeds compressed air to the shearing punches 15 to be activated, and this facilitates the activation of the sliding of the slide 34 corresponding to the punches 15 to be activated.

[0059] By feeding compressed air into the seat 36 via the fitting 38, the corresponding slide 34 slides in the seat 36 and moves in the direction of the center of the lower block 30", compressing the elastic means 35 (e.g., Figure 7 The through hole or through opening 30B of the lower block 30" is closed, the corresponding portion of the spacer 16 slides in the through hole or through opening 30B, and the corresponding shear punch 15 enters the die of the shearing die and shears the large sheet to produce a sheet (such as by Figure 7 ), while the inactivated shear punch 15 (for inactivated compressed air flow) is in a stationary position (as indicated by the arrow "X" in FIG. 1 ) abutting against the tail portion 34" of the slide 34. Figure 7 (indicated by the arrow “X” in the figure).

[0060] As can be seen from the foregoing, the advantages achieved by the apparatus of the present invention for shearing dies for use in manufacturing sheets for electrical applications are evident.

[0061] The device of the invention for manufacturing a shearing die for sheets for electrical use advantageously allows limiting the dimensions and weight and can therefore be easily installed inside a shearing die.

[0062] Another advantage of the device of the invention is that it is simplified relative to conventional devices and allows a drastic reduction in the probability of breakage and / or jamming of the mechanism for transmitting the movement to the shear punch.

[0063] Also advantageous is the fact that the device of the invention allows the shearing punches to be driven simultaneously or selectively even during the same step of shearing the die.

[0064] Another advantage of the device of the invention is that it does not require additional plates to be able to combine the moving rod and the slide to achieve the transmission of movement to the shear punch, as otherwise occurs in devices of traditional type.

[0065] Another advantage of the device of the invention is the ease of maintenance, repair and / or replacement operations, which thus reduces the time and the associated costs.

[0066] Although the present invention has been described above with particular reference to embodiments given only as non-limiting examples, many modifications and variations will be apparent to those skilled in the art from the above description. Therefore, the present invention is intended to include all modifications and variations falling within the scope of the appended claims.

Claims

1. An apparatus (10, 10') for shearing dies for sheets for electrical use, the function of which is to form layered stacks for electrical use in electric machines such as motors, generators, transformers, counters, ignition coils and similar electrical devices, characterized in that The device (10, 10') comprises a box-shaped body (12, 30), the box-shaped body (12, 30) comprising a device for simultaneously or selectively activating / deactivating the shearing punches (15) of the shearing die during the shearing step, the shearing punches (15) being connected to a spacing device (16), the spacing device (16) comprising an elastic element (16'), the number of the activation / deactivation devices corresponding to the number and position of the punches (15), and the activation / deactivation devices comprising a sliding member (18, 34), the sliding member (18, 34) being able to translate in a dedicated seat (19, 36) formed in the lower block (12", 30") of the box-shaped body (12, 30), the sliding member (18, 34) cooperating with the elastic element (20, 35) accommodated in the seat (19, 36).

2. The device (10, 10') according to claim 1, characterized in that The box-like body (12, 30) comprises an upper block (12', 30') and a lower block (12", 30") which are airtightly and rigidly constrained to each other, and the lower block (12", 30") has a through hole or through opening (12B, 30B) formed in the thickness of the base of the lower block (12", 30") to accommodate a part of the spacer (16) to which the shear punch (15) is connected.

3. The device (10, 10') according to claim 1, characterized in that The elastic element (20, 35) comprises a compression spring.

4. The device (10, 10') according to claim 1, characterized in that The slide (18, 34) comprises a head portion (18', 34') and a tail portion (18", 34"), the tail portion (18", 34") being oriented in the direction of the elastic element (20, 35) and having different dimensions relative to the head portion, the head portion (18', 34') and the tail portion (18", 34") being respectively suitable for closing the through hole or through opening (12B, 30B) of the lower block (12", 30") and for defining an abutment for the spacer (16) for activating / deactivating the shearing action of the punch (15).

5. Device (10, 10') according to the preceding claim, characterized in that The slides (18, 34) are arranged according to a radial direction with forward / rearward sliding movement relative to the center of the lower block (12", 30").

6. Device (10, 10') according to the preceding claim, characterized in that The slides (18, 34) are arranged according to the arrangement configuration of the shearing die (15).

7. Device (10) according to the preceding claim, characterized in that The device (10) comprises a distributor assembly (24) for distributing compressed air fed through the fittings (22) in all the seats (19) of the slide (18) for the sliding movement of the slide (18) and the simultaneous activation / deactivation of the shear punches (15).

8. Device (10') according to the preceding claim, characterized in that The device (10') comprises a fitting (38) fixed to the box-like body (30) at each slide (34), the fitting (38) being used for the selective sliding movement of each slide (34) in its corresponding seat (36) for selectively activating / deactivating the shear punch (15).

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