DK166438B1

DK166438B1 - Press tool with working parts that are detachable during operation

Info

Publication number: DK166438B1
Application number: DK128186A
Authority: DK
Inventors: Dorice Vrignaud
Original assignee: Esswein Sa
Priority date: 1986-03-20
Filing date: 1986-03-20
Publication date: 1993-05-24
Also published as: DK128186D0; DK128186A

Description

i DK 166438 B1in DK 166438 B1

Opfindelsen angår et presseværktøj af den i krav 1's indledning angivne art.The invention relates to a pressing tool of the kind specified in the preamble of claim 1.

Til fremstilling af metalemner ud fra en tyndplade anven-5 des der normalt værktøj til montering på stansemaskiner og indrettet til at foretage lokning, stansning, dybtrækning og lignende operationer. Disse værktøjer omfatter normalt dele, såsom stanser og matricer, der slides forholdsvis hurtigt, fastspændingselementer såsom stansehol-10 dere, matriceholdere og påfæstningsblokke, som er monteret på stansemaskinens henholdsvis slæde og bord, og en emneholder normalt indrettet til både at fastpositionere et metalpladeemne under dettes formning og til at styre stanserne under deres bevægelse. Da sådanne stanser er 15 mere eller mindre skøre, er stanseværktøjer konventionelt indrettet således, at stansernes ender under hvile eller ved afslutning af deres tilbagetrækning eller frigørelsesslag forbliver delvis i indgreb med styrehullerne i deres emneholder. Dette betyder, at under drift kan disse 20 stanser ikke fjernes med henblik på udskiftning eller eftersyn, når værktøjerne stadig befinder sig i stilling på stansemaskinen. Udskiftning og vedligeholdelse af stanser og matricer i de konventionelle værktøjer kan altså ikke foretages i stilling på maskinen, hvilket medfører tab af 25 arbejdstid og ret store operatøromkostninger.For the manufacture of metal workpieces from a thin plate, tools are usually used for mounting on punching machines and arranged to perform latching, punching, deep drawing and similar operations. These tools usually comprise parts such as dies and dies that wear out relatively quickly, clamping elements such as die holders, die holders and attachment blocks mounted on the punch and slide of the punching machine and a blank holder usually arranged to both position a metal sheet member underneath it. forming and controlling the punches during their movement. Since such punches are more or less fragile, punching tools are conventionally arranged such that the ends of the punches during rest or at the end of their retraction or release stroke remain partially engaged with the guide holes in their workpiece holder. This means that during operation, these 20 punches cannot be removed for replacement or inspection when the tools are still in position on the punching machine. Thus, replacement and maintenance of punches and dies in the conventional tools cannot be done in position on the machine, which results in the loss of 25 working hours and quite large operator costs.

Et af disse presseværktøjer er beskrevet i US-A-3 125 917; det er et økonomisk presseværktøj med standardiserede elementer, som tillader en udskiftelighed af stanser og ma-30 tricer under en ændring af fabrikationsdele. De standardiserede elementer har hovedsagelig, på den ene side, parrede eller identiske plader med standardiserede åbninger og bestemt til at danne en emneholder og fastgørelsesblokke til at holde stanserne og matricerne, og på den anden side 35 stanser og matricer, som i deres dele, ved sammenføjning med disse plader, udviser dimensioner indstillet til de standardiserede åbningers dimensioner svarende til de DK 166438 B1 2 sidste plader. Emneholderen, som er indrettet til at holde en plade på plads på en måde, hvor den er underkastet en operation i værktøjet, og til at styre stanserne i deres glidebevægelse og styre dem ved styresøjlerne, er selv 5 styret af styresøjlerne, hvor en ansats samvirker med en glidebøsning og et anslag for at begrænse emneholderens bevægelse og holde stanserne i deres styring permanent til nævnte emneholder. Stanserne i værktøjet skilles med andre ord aldrig helt fra emneholderen, hverken under deres 10 hviletid eller under deres arbejde. For således at skifte eller erstatte dem er det nødvendigt at demontere og fjerne værktøjet helt fra pressen, hvorpå dette værktøj er monteret.One of these pressing tools is described in US-A-3,125,917; it is an economical press tool with standardized elements that allow for the interchangeability of punches and mats during a change of fabrication parts. The standardized elements mainly have, on the one hand, paired or identical plates with standardized openings and intended to form a workpiece holder and fastening blocks for holding the punches and dies, and on the other hand 35 punches and dies, as in their parts, joining these plates exhibits dimensions set to the dimensions of the standardized apertures corresponding to the last plates of DK 166438 B1. The workpiece holder, which is arranged to hold a plate in place in a manner in which it is subjected to an operation in the tool, and to control the punches in their sliding movement and guide them by the steering columns, is itself controlled by the steering columns, where a staff cooperates. with a sliding sleeve and a stop to restrict the movement of the workpiece and to hold the punches in their control permanently to said workpiece. In other words, the punches in the tool are never completely separated from the workpiece holder, neither during their 10 rest or during their work. Thus, in order to replace or replace them, it is necessary to completely disassemble and remove the tool from the press on which this tool is mounted.

15 Opfindelsen har til formål at afhjælpe denne ulempe og tilvejebringe et økonomisk stanseværktøj med arbejdende dele, især stanser, der kan aftages i stilling på maskinen, og som monteret på denne kan bearbejde et metalemne af tyndplade ved stansning, lokning, dybtrækning, skæring 20 og lignende operationer.The invention has for its object to alleviate this disadvantage and to provide an economical punching tool with working parts, in particular punches which can be removed in position on the machine, and which mounted thereon can process a sheet metal blank by punching, closing, deep drawing, cutting 20 and similar operations.

Dette opnås for et stanseværktøj af den indledningsvis angivne art, der er udformet som angivet i krav l's kendetegnende del. Her kan hver stanse og hver matrice repa-25 reres eller udskiftes, medens værktøjet er monteret i stansemaskinen.This is accomplished for a punching tool of the type specified in the introduction, which is configured as defined in the characterizing part of claim 1. Here, each punch and die can be repaired or replaced while the tool is mounted in the punching machine.

Opfindelsen forklares nærmere nedenfor i forbindelse med tegningen, hvor: 30 fig. la, lb og lc er et lodret snit gennem et værktøj i-følge opfindelsen, hvor fig. la viser det lukkede værktøj, det vil sige enden af det arbejdsslag, der svarer til det nedadgående slag af slæden i et stanseværktøj, fig. Ib vi-35 ser det åbne værktøj med emneholderen under foretagelse af et normalt returslag svarende til enden af det opadgående· 3 DK 166438 B1 slag for stanseværktøjets slæde, og fig. lc viser det åbne værktøj med emneholderen under foretagelse af et mellemliggende returslag svarende til enden af det opadgående slag for et stanseværktøjs slæde, 5 fig. 2 er et snit gennem et værktøj svarende til fig. 1 og fastgjort på et stanseværktøj og visende de relative stillinger af stanserne, matricen og emneholderen ved enden af værktøjets arbejdsslag, 10 fig.; 3 er en afbildning fra oven af emneholderen for det på fig. 2 viste værktøj og på højre halvdel visende emneholderen i normal arbejdsstilling eller tilbagetrukket stilling og på venstre halvdel visende emneholderen i den mellemliggende stilling, og fig. 4 er en udtrukket perspektivisk afbildning af en slædeforbindelse til forbindelse af en emneholder med værktøjets bundplade og dens styreorgan.The invention is further explained below in connection with the drawing, in which: FIG. 1a, 1b and 1c are a vertical section through a tool according to the invention, in which fig. 1a shows the closed tool, i.e. the end of the working stroke corresponding to the downward stroke of the sled in a punching tool; FIG. Fig. 1b-35 shows the open tool with the workpiece holding a normal return stroke corresponding to the end of the upward stroke of the punch tool, and fig. 1c shows the open tool with the workpiece holder making an intermediate return stroke corresponding to the end of the upward stroke of a punching tool sled; FIG. 2 is a section through a tool similar to FIG. 1 and attached to a punching tool and showing the relative positions of the punches, die and workpiece holder at the end of the tool stroke, FIG. 10; 3 is a top plan view of the blank holder of the blank shown in FIG. 2 and the right half showing the workpiece holder in normal working position or retracted position and the left half showing the workpiece holder in the intermediate position; and fig. 4 is an exploded perspective view of a sled connection for connecting a workpiece holder with the tool base and its guide.

2020

Et stanseværktøj kan være udformet til at foretage en bestemt operation på et metalemne af tyndplade til at give emnet en mere eller mindre kompleks form, og operationer såsom skæring, værkling osv. kan normalt ikke udføres med 25 et enkelt værktøj af denne art, men foretages ved hjælp af en række sådanne værktøjer. En sådan værktøjsrække omfatter en rækkefølge af arbejdsstationer, forbi hvilke et tyndpladeemne føres med fastlagte mellemrum til ved hver arbejdsstation at foretage en bestemt operation, såsom 30 stansning, dybtrækning, skæring osv., til ved udløbet fra den sidste arbejdsstation at udtage et færdigt emne løsrevet fra metalstrimlen og frembydende en mere eller mindre kompleks form. Opfindelsen er anvendelig i forbindelse med begge de nævnte værktøjsarter.A punching tool may be designed to perform a particular operation on a sheet metal blank to give the blank a more or less complex shape, and operations such as cutting, machining, etc. cannot usually be performed with a single tool of this kind, but performed using a variety of such tools. Such a series of tools comprises a sequence of workstations past which a thin plate blank is routed at specified intervals to perform a specific operation at each workstation, such as punching, deep drawing, cutting, etc., to take out a finished workpiece at the outlet of the last workstation. from the metal strip and presenting a more or less complex shape. The invention is applicable to both of the mentioned tool types.

35 DK 166438 B1 435 DK 166438 B1 4

Fig. 1 og 2 viser en udførelsesform for et stanseværktøj 1 ifølge opfindelsen og af rækkefølge-arten, indrettet til montering på en stansemaskine 2, hvis bord 3 og slæde- . blok 4 er vist med stiplede linier.FIG. 1 and 2 show an embodiment of a punching tool 1 according to the invention and of the order type, arranged for mounting on a punching machine 2, whose table 3 and sled. block 4 is shown in dotted lines.

55

Stanseværktøjet 1 omfatter for det første en matrice 5, der holdes i stilling af en matriceholder 8, og en nederste fastgørelsesblok 11, der er monteret på stansemaskinens bord 3, for det andet en stanse 12., der er fastgjort i 10 stilling i en stanseholderring 13, og en øverste fastgørelsesblok 18, der er monteret på stansemaskinens slæde 4, og for det tredje en emneholder 19 anbragt mellem matricen 5 og stansen 12 og indrettet til både at fastholde en metalstrimmel 20 i stilling mod matricen 5 og til at styre 15 stansen 12 under dennes forskydning. Matricen 5 og matrice-holderen 8 er fastgjort på deres fælles blok 11 og kan fjernes og udtages fra denne. Det samme gælder stansen 12 og stanseholderen 15 i forhold til den øverste fastgørelsesblok 18.The punching tool 1 comprises, first, a die 5 held in position by a die holder 8 and a lower attachment block 11 mounted on the punching machine's table 3, secondly a die 12, which is fixed in position 10 in a die holding ring 13, and a top mounting block 18 mounted on the punch 4 of the punching machine, and third, a workpiece holder 19 disposed between the die 5 and the die 12 and arranged to both hold a metal strip 20 in position against the die 5 and to guide the die 12 during its displacement. The die 5 and die holder 8 are attached to their common block 11 and can be removed and removed from it. The same applies to the punch 12 and the punch holder 15 with respect to the top attachment block 18.

2020

Enden af slædens 2 normale arbejdsslag, der falder sammen med enden af værktøjets normale arbejdsslag, er vist på fig. la, medens enden af slædens 4 normale returslag, der falder sammen med enden af værktøjets normale returslag, 25 er vist på fig. Ib.The end of the normal working stroke of the carriage 2 which coincides with the end of the normal working stroke of the tool is shown in FIG. 1a, while the end of the normal return stroke of the carriage 4 coincides with the end of the normal return stroke of the tool 25 is shown in FIG. Ib.

Ved fuldførelsen af et normalt returslag for værktøjet 1 bevæger stansen 12 og emneholderen 19 sig bort fra matricen 30 5 (fig. Ib), men denne stanse forbliver stadig delvis i indgreb med et tilsvarende form- eller styrehul 21 i emneholderen 1. I sådanne indbyrdes stillinger af denne stanse 12 og denne emneholder 19 er det vanskeligt og ligefrem umuligt at fjerne denne stanse, når værktøjet 1 forbliver 35 fastgjort på stansemaskinen 2.Upon completion of a normal return stroke for the tool 1, the punch 12 and the workpiece 19 move away from the die 30 5 (Fig. 1b), but this punch still remains partially engaged with a corresponding mold or guide hole 21 in the workpiece holder 1. In such mutually positions of this punch 12 and this blank holder 19, it is difficult and even impossible to remove this punch when the tool 1 remains 35 attached to the punch machine 2.

DK 166438 Bl 5DK 166438 Pg 5

Ifølge opfindelsen er emneholderen 19 imellem stansen 12 og matricen 5 indrettet til at foretage mindst et normalt arbejdsslag og flere returslag efter ønske, nemlig et normalt returslag og et mellemliggende returslag. Under sit 5 normale arbejdsslag styrer emneholderen 19 stansen 12 under dennes forskydning og fastholder sikkert i stilling metalstrimlen 20 imod matricen 5 ved afslutningen af dette slag. Ved enden af sit normale returslag frigøres emneholderen 19 fra matricen 5, men stansen 12 forbliver delvis 10 i indgreb med det tilsvarende styrehul 21 i denne emneholder 19.According to the invention, the blank holder 19 between the punch 12 and the die 5 is arranged to make at least one normal working stroke and several return stroke as desired, namely a normal return stroke and an intermediate return stroke. During its normal working stroke, the workpiece 19 controls the punch 12 during its displacement and securely holds in position the metal strip 20 against the die 5 at the end of this stroke. At the end of its normal return stroke, the blank holder 19 is released from the die 5, but the punch 12 remains partially engaged with the corresponding guide hole 21 in this blank holder 19.

Under et mellemliggende returslag frigøres emneholderen 19 fra matricen 5, og stansen 12 forlader sit styrehul 21 ved 15 enden af det opadgående slag for stansemaskinens slæde og frigøres fuldstændigt fra denne emneholder, som vist på fig. lc.During an intermediate return stroke, the workpiece holder 19 is released from the die 5, and the punch 12 leaves its guide hole 21 at the end of the upward stroke of the punching machine sled and is completely released from this workpiece holder, as shown in FIG. lc.

Emneholderen 19, stansen 12 og dennes stanseholder 15 og 20 den af stansemaskinens slæde 4 understøttede øverste fastgørelsesblok 18 styres hver især under deres forskydning under arbejds- og returslagene i forhold til matricen 5 og dennes matriceholder 8 og den til stansemaskinens bord 3 fastgjorte nedersteblok 11 ved hjælp af fire søjler 22 25 (fig. 3), af hvilke den ene er vist i snit på fig. 2. Styresøjlerne 22 er i det viste udførelseseksempel kugle-søjler af en kendt type.The workpiece holder 19, the punch 12 and its punch holder 15 and 20 the upper fastening block 18 supported by the punch machine 4 are each controlled during their displacement during the working and return strokes relative to the die 5 and its die holder 8 and the lower block 11 fixed to the punching machine table 3 by by means of four columns 22 25 (Fig. 3), one of which is shown in section in Figs. 2. In the illustrated embodiment, the guide columns 22 are spherical columns of a known type.

2Q Ifølge et andet væsentligt træk ved opfindelsen er emneholderen 19 for at kunne foretage sit normale arbejdsslag og sine to returslag efter ønske mekanisk forbundet med den øverste fastgørelsesblok 18, der understøtter stansen 12 og dennes stanseholder 15, via glidere 23, der hver omfatter to stopansatser efter ønske, hvoraf den ene angiver 35 enden af emneholderens normale returslag, hvor stansen 12 forbliver i delvis indgreb med emneholderen 19, og den an- ill DK 166438 B1 6 den repræsenterer enden af emneholderens normale mellemliggende returslag, hvor stansen 12 er beliggende helt uden for denne emneholder 19.2Q According to another essential feature of the invention, the blank holder 19 is capable of being mechanically connected to its upper working stroke and its two return strokes, as desired, with the upper fastening block 18 supporting the punch 12 and its punch holder 15, via sliders 23, each comprising two stop stops. as desired, one of which indicates the end of the ordinary return stroke of the workpiece, where the punch 12 remains in partial engagement with the workpiece 19 and the corresponding DK 166438 B1 6 represents the end of the normal intermediate return stroke of the workpiece where the punch 12 is located completely without for this item holder 19.

5 I det viste udførelseseksempel (fig. 3) er der fire glidere 23, der hver omfatter (fig. la, lb, lc, 2, 4) en bøsning 25 fastgjort til emneholderen 19, en holdeskrue 24 med et spærrehoved fastgjort til den øverste værktøjsblok 18 gennem bøsningen 25 samt en bevægelig eller aftagelig knægt 10 26 i indgreb med skruen 24 mellem dennes hoved og bunden af bøsningen 25- Bøsningen 25 og den bevægelige knægt 26 fungerer som ansatser for henholdsvis enden af det mellemliggende returslag og enden af det normale returslag.In the illustrated embodiment (Fig. 3), there are four sliders 23, each comprising (Figs. 1a, 1b, 1c, 2, 4) a bushing 25 attached to the workpiece holder 19, a retaining screw 24 with a locking head attached to the upper one. tool block 18 through the bush 25 and a movable or removable jack 10 26 engaging the screw 24 between its head and the bottom of the bush 25 The bush 25 and the movable jack 26 act as abutments for the end of the intermediate return stroke and the end of the normal return stroke, respectively. .

15 Bøsningen eller ansatsen 25 består af et legeme udformet som et omvendt langstrakt U med -et hul i åget til glidefor-skydning af holdeskruen med spærrehovedet 24 sammen med sidevægge med en gennemgangsåbning 31 for knægten 26, hvorhos 20 der ved dens frie ende er udformet en tilbageholdskulder.The sleeve or shoulder 25 consists of a body formed as an inverted elongated U with a hole in the yoke for sliding the retaining screw with the locking head 24 along with side walls with a through opening 31 for the jaw 26, 20 formed at its free end. a restraining shoulder.

Disse skuldre kan forsynes med huller til påfæstningsskruer 27. Længden af bøsningen eller ansatsen 25 er større end tykkelsen af emneholderen 19, og når bøsningen 25 fastgøres ved hjælp af skruerne 27 på emneholderen 19 gennem et til-25 svarende hul 28 i denne, vil bunden af ansatsen rage op over overfladen af emneholderen på den modsatte side af påfæstningsfladen med en længde, der svarer til tykkelsen af den aftagelige knægt eller ansats 26 forøget med tykkelsen af bøsningens eller ansatsens 25 bund.These shoulders may be provided with holes for attachment screws 27. The length of the bushing or shoulder 25 is greater than the thickness of the workpiece holder 19 and when the bushing 25 is secured by the screws 27 to the workpiece holder 19 through a corresponding hole 28 therein, the bottom of the abutment protrude over the surface of the workpiece holder on the opposite side of the attachment surface of a length corresponding to the thickness of the removable jib or abutment 26 increased by the thickness of the bottom of the bushing or abutment 25.

3030

Den tilbagetrækkelige knægt eller ansats 26 består af et legeme med to arme og udtrække ligt ved hjælp af et greb 29, der ved siderne kan forsynes med vinger (ikke vist).The retractable jack or shoulder 26 consists of a two-arm body and extends corrugated by a handle 29, which can be provided with wings (not shown) at the sides.

35 Sådanne vinger giver gaflen eller ansatsen 26 en god stabilitet under dens forskydning frem og tilbage. Under 7 DK 166438 B1 sin fremskydning (fig. la, lb, 2, 3 højre side) glider ansatsen 26 på emneholderens 19 overflade og trænger igennem bøsningen eller ansatsen 25 gennem åbningen 31, og dens greb 29 rager sidelæns uden for bøsningen 25. Under 5 sin tilbagetrækning (fig. lc og 3 venstre side) glider ansatsen 26 på emneholderens 19 overflade og forlader bøsningen eller ansatsen 25 gennem åbningen 31.Such wings give the fork or shoulder 26 good stability during its forward and backward displacement. During its projection (Fig. 1a, 1b, 2, 3 right side), the shoulder 26 slides on the surface of the workpiece 19 and penetrates the sleeve or shoulder 25 through the opening 31, and its grip 29 extends laterally outside the sleeve 25. Below In its retraction (Figs. 1c and 3 left), the shoulder 26 slides on the surface of the workpiece 19 and leaves the sleeve or shoulder 25 through the opening 31.

Ifølge et andet træk ved opfindelsen er de fire gafler el-10 ler ansatser 26 fastgjort til et og samme styreorgan 32, som tildeler dem en samtidig bevægelse under deres forskydning til deres fremskudte eller tilbagetrukne stilling.According to another feature of the invention, the four forks or abutments 26 are attached to one and the same guide member 32 which assigns them a simultaneous movement during their displacement to their extended or retracted position.

Styreorganet 32 omfatter en forreste stang 33 og to side-15 vendende glideforskydelige skinner 34 og 35, til hvilke ansatserne 26 er fastgjort. Den forreste stang 33 er forsynet med greb 36, og de to skinner 34, 35 er monteret glideforskydelige langs emneholderens 19 sidekanter på konventionel måde.The control member 32 comprises a front bar 33 and two side sliding slides 34 and 35 to which the abutments 26 are attached. The front bar 33 is provided with grips 36 and the two rails 34, 35 are slidably mounted along the lateral edges of the workpiece 19 in a conventional manner.

2020

Under normal drift af værktøjet 1 i stansemaskinen 2 indsættes ansatserne 26 samtidigt i de glideforskydelige forbindelsesorganers .23 tilsvarende bøsninger eller ansatser 25 mellem disses bunde og spærrehovederne på de glide-25 forskydelige holdeskruer 24, og i dette tilfælde har emne-holderen 19 et normalt arbejdsslag og et normalt returslag.During normal operation of the tool 1 in the punching machine 2, the lugs 26 are simultaneously inserted into the corresponding bushings or lugs 25 between their slides and the latches 25 between the slats and the locking heads of the slide 25 sliding retaining screws 24, in which case the workpiece holder 19 has a normal working stroke and a normal return stroke.

Ved afslutningen af det normale arbejdsslag antager stansen 12, matricen 5, emneholderen 19 og metalstrimlen 20 de respektive stillinger som vist på fig. la, lb og 2, og ved 30 afslutningen af det normale returslag standses hovederne af holdeskruerne 24 i de glideforskydelige forbindelses-organer 23 af ansatserne 26, og stansen, matricen og emne-holderen i værktøjet 1 indtager de på fig. lb viste respektive stillinger.At the end of the normal working stroke, the punch 12, die 5, workpiece holder 19 and metal strip 20 assume the respective positions as shown in FIG. 1a, 1b and 2, and at the end of the normal return stroke, the heads of the retaining screws 24 in the slidable connecting members 23 are stopped by the abutments 26, and the punch, die and workpiece holder in the tool 1 occupy the ones of FIG. 1b respectively.

35 8 DK 166438 B135 8 DK 166438 B1

Under vedligeholdelseseftersyn eller udskiftning af en eller flere stanser 12 i de glideforskydelige forbindelsesorganer 23 trækkes knægtene 26 samtidigt tilbage fra ydersiden af bøsningerne 25 ved anvendelsen af et styre-5 organ 32, og i dette tilfælde har emneholderen 19 et normalt arbejdsslag identisk med arbejdsslaget under normal drift af værktøjet 1 og et mellemliggende returslag som vist på fig. lc, hvor holdeskruehovederne 24 standses af de respektive bunde på ansatserne 25 og ikke af knægtene 26, som allerede er trukket tilbage. Dette betyder, at under det mellemliggende returslag bevæges emneholderen 19 bort fra den øverste fastgørelsesblok 18, der understøtter en eller flere stanser, i en afstand (fig. lc), der er større end afstanden for et normalt returslag af emnehol-15 deren (fig. Ib), så at stansen eller stanserne 12 fuldstændigt frigøres fra emneholderen 19 (fig. lc). Derved kan stanserne let afmonteres eller fjernes samtidigt med de enkelte matricer 5, uden at der kræves afmontering af værktøjet 1 uden for maskinen for at kunne foretage en · 20 udskiftning eller vedligeholdelsesarbejder.During maintenance inspection or replacement of one or more punches 12 in the slidable connecting members 23, the jaws 26 are simultaneously withdrawn from the outside of the bushes 25 by the use of a guide member 32, and in this case the blank holder 19 has a normal working stroke identical to the normal working stroke. operation of the tool 1 and an intermediate return stroke as shown in FIG. 1c, wherein the retaining screw heads 24 are stopped by the respective bottoms of the abutments 25 and not by the jaws 26 which have already been retracted. This means that during the intermediate return stroke, the blank holder 19 is moved away from the upper fastening block 18 supporting one or more punches at a distance (FIG. 1c) greater than the distance of a normal return stroke of the blank holder (FIG. 1b) so that the punch or punches 12 are completely disengaged from the blank holder 19 (Fig. 1c). In this way, the punches can be easily removed or removed simultaneously with the individual dies 5 without the need for removal of the tool 1 outside the machine in order to perform a · 20 replacement or maintenance work.

25 1 3525 1 35

Claims

9 DK 166438 B1 Patent claims:

1. Press tool with working parts in the form of one or 5 multiple dies (5) and one or more punches (12) and a workpiece holder (19) for controlling each die during its displacement and for retaining a strip (20) of metal plate on each die (5) during shaping, characterized in that the tool between the die 20 or die (5) and the die (s) (12) has a workpiece (19) which performs at least one normal working stroke and, selectively, two return strokes. , ie a normal return stroke and an intervening return stroke, wherein the blank holder (19) during the normal return stroke partially retains the punch or punches (12) and wherein the blank holder (19) during the intervening return stroke comes out of engagement with each punch (12).

A tool according to claim 1 having a top block (18) which is 2o fixed to a carriage (2) carriage (4) and carrying the punch (s) (12) and die holders, and a bottom block (11) which is fixed to a table (13) on the press (2) and carrying the die or dies (5) and die holders, characterized in that the blank holder (19), 25 for carrying out its normal working stroke and its two return strokes, is selectively mechanically connected to the tool upper block (18) with sliding connecting means (23), each having two selective stop stops (25 and 26), one of which marks the normal return stroke, the punch or punches (12) remaining partially engaged by the workpiece holder (19 ), and the second marks the intervening return stroke in which the punch or punches (12) are positioned completely within the blank holder (19). 1

Tool according to claim 2, characterized in that the sliding connecting means (23) each comprise a retaining screw (24) with a stop head fixed to the upper block (18) of the tool, a first selective stop stop in in the form of a sleeve (25) slidably mounted on the retaining screw (24) and secured to the workpiece holder (19) to serve as a stop at the end of the intervening return stroke and another selective stop stop in the form of a fork (26) ) which, depending on its connection in the bush (25) between a retractable head of the retaining screw (24) and the bottom of the bush (25) or its release from the bush (25), establish a normal return stroke of the workpiece (19) or a intervening return stroke of the item holder (19).

Tool according to claim 3, characterized in that the sleeve (25) in the sliding connecting means (23) 15 consists of a part with a longitudinal section in the form of an inverted and elongated U with a side wall with a passage opening (31), for the fork (26) and with a free end provided with a holding shoulder. 20

Tool according to any one of claims 3 and 4, characterized in that the fork (26) in the sliding connecting means (23) consists of a part with two arms which is extended by a handle (29) which protrudes. from the bush (25). 25

Tool according to any one of claims 3 to 5, characterized in that the fork (26) in the sliding connecting means (23) is fixed to a single control means (32) which causes them to move simultaneously during their displacement when they are brought into place or retracted.

Tool according to claim 6, characterized in that the guides (32) for the forks (26) of the sliding connecting members (23) comprise a front bar (33) provided with grips (36) and two slidable rails (34 and 35) on which the forks (26 are attached.