EP1449599B1 - Fastening device for mounting and disassembling a bending tool - Google Patents

Abstract

The system has a tightening body with a tightening surface that cooperates with one of fixing surfaces of a tool. A blade has an elastically deformable branch (58a) integrated with a tightening clamp (20). Another branch (58c) of the blade has an end penetrated through a retention groove (38) and a part cooperates with a lower edge (38b) of the groove when the tool is pivoted. An angular part is located between the branches.

Description

The present invention relates to a fastening system for mounting and dismounting a folding tool on the upper apron of a press brake.

Bending presses are used for forming sheet materials and comprise for this purpose one or more tools commonly called punches fixed on the mobile deck of the machine by a fastening system or tool holder and, with regard to these tools, one or several V-shaped dies attached to the upper edge of the lower apron of the press brake.

By arranging the sheet to be formed on the die and causing the punch to be lowered by a predetermined amount, the sheet is bent to the desired angle.

In addition, depending on the type of forming and the size of this forming to be made on the sheet materials, the tool used is different. It is therefore necessary to be able to disassemble the tool of the upper deck, that is to say the fastening system to replace it with another tool more suitable.

As is well known, the fastening of the tool which comprises a fixing heel is carried out by means of a pivotally mounted flange which can occupy a first clamping position of the tool or a second position which allows the change to take place. of the tool.

It is also understood that the folding tools are relatively heavy. It is therefore very desirable to maintain the tool on the clamping flange even when it is in the loosened position in order to avoid any risk of falling of the tool on the matrix of the lower deck disposed opposite this tool.

In the French patent application 00 07 415 in the name of the applicant, there is described an embodiment of a tool holder or attachment system of the tool that allows effective control of the pivoting of the flange and the retention of the tool after loosening the flange.

In Figures 1A and 1B appended, there is shown the embodiment of the attachment system of the tool described in the patent application mentioned above. In these figures, there is shown the movable upper deck 10 and the tool spacer 12 fixed by any suitable means on the upper deck 10. The tool spacer comprises a lower portion 14 of reduced thickness, defined by two shoulders 16 and 18.

The fastening system also comprises a clamping flange 20 which is pivotally mounted about a horizontal axis parallel to the length of the deck. The pivot axis can be defined by screws 22 with swiveling head cooperating with corresponding holes 24 machined in the middle portion 26 of the flange 20. To control the pivoting of the flange 20 around the axis defined by the heads of the 22, one can use pushers 28 whose one end acts on the upper end 30 of the flange 20 and whose second end cooperates with a rotary cam 32 mounted in the tool spacer 12 in the longitudinal direction of the apron . In this embodiment, the cam 32, in the position shown in Figure 1A, causes the separation of the upper portion 30 of the flange, which corresponds to the clamping position. On the other hand, in its position shown in FIG. 1B, the cam 32 no longer acts on the pushers 28 and, under the effect of an elastic system, the flange 20 assumes the position of assembly and disassembly of the tool shown. in Figure 1B.

The tool 34 has at its upper part a fixing heel 36 which has a first attachment surface 36a, a second attachment surface 36b parallel to the first attachment surface and a retention groove 38 located below the second surface 36b and having upper edges 38a and lower 38b.

In the clamping position shown in FIG. 1A, the attachment surfaces 36a and 36b of the heel of the tool are sandwiched between the clamping surface 14a of the end 14 of the tool spacer and the clamping surface 40. of the lower part 42 of the flange 20.

In addition, at its lower end 42, the flange comprises a spoiler-shaped retaining means 44 which can enter the groove 38 of the heel of the tool 34. When the flange 20 is in the clamping position shown in FIG. 1A, the spoiler 44 plays no role. On the other hand, when the lower end 42 of the flange is spaced to occupy the mounting-disassembling position, the spoiler 44 remains partially engaged in the groove 38, as shown in FIG. 1B, which ensures the maintenance in the vertical direction of the tool 34 relative to the tool spacer 12.

This system allows effective retention of the tool preventing its fall, but nevertheless, it has the following disadvantage. When the flange 20 is brought into its assembly-disassembly position, the removal of the tool 34 can only be achieved by the longitudinal ends of the flange 20 by sliding the bead of the tool between the flange and the lower part. 14 of the tool spacer.

It will be understood that because the tool can be placed between the lower part of the tool spacer and the flange only laterally, that is to say by the ends of the flange, when the operator wants to replace a tool that is mounted for example in the central portion of the flange, it is necessary that it proceeds prior to disassembly of the tools disposed between the tool actually to change and one end of the flange.

These relatively tricky operations of removing a plurality of tools substantially increase the time of change of the desired tool and thus result in a decrease in the productivity of the press brake. The higher the frequency of change of tools, the greater the loss of time.

Also known is the fastening system of a folding tool described in US Patent 5,022,256 to Machinefabriek Wila BV This system also comprises a tool spacer and a clamping flange, pivotally mounted around a horizontal axis parallel to the length of the deck, the pivoting of the flange being controlled by means of hydraulic cylinders.

In addition, the system comprises an elastically deformable metal strip pivotally mounted about a horizontal axis parallel to the length of the apron on the clamping flange and having a first surface opposite the clamping flange and a second surface opposite the lower part of the tool spacer. A rigid piece is fixed on the second surface, in the lower part of the metal strip. This rigid piece has in its lower part, an inclined surface, approximating the metal strip.

When the flange is spaced to occupy the mounting position / disassembly of the tool, the metal strip is separated from the flange and the upper edge of the rigid piece cooperates with a shoulder performed on the attachment heel of the tool so as to prevent the tool from falling.

When the flange is brought into the clamping position of the tool, the attachment bead of the tool is clamped on one side by the lower part of the tool spacer and on the other by the rigid part. which refers to the tool the force exerted on it by the clamp.

The assembly constituted by the metal strip and the rigid part is therefore subjected to very high compressive stresses, which makes it necessary to use materials to make the different parts, and fastening means to secure the parts together, capable of to support such constraints.

In order to reduce the stresses to which said assembly is subjected, it is provided in US Pat. No. 5,022,256 to provide a flexible plastic strip between the clamping flange and the metal strip, housed in a groove formed in the clamping flange. . This solution then has the disadvantage of making more complex the shape of the flange.

Furthermore, in this type of system, the elastically deformable metal strip is subjected to high compressive stresses and regularly repeated which make it gradually lose its elasticity properties, which affects the proper functioning of the system.

An object of the present invention is to provide on the one hand, a tool attachment system on the upper deck of a press brake which retains the principle of fixing the tool by clamping between a clamping surface present on the on the one hand and a clamping surface on the flange on the other hand, that is to say without intermediate element involved in clamping, located between the flange and the tool, and secondly, a system that allows the assembly and the front dismantling of the tools on the upper apron, in order to be able to change only the desired tool.

To achieve this object, according to the invention, the attachment system of a folding tool, said tool comprising two clamping attachment surfaces and a retaining groove located below one of the attachment surfaces and having upper edges and lower, comprises a clamping body having a first clamping surface adapted to cooperate with one of the attachment surfaces of the tool and a clamping clamp of the pivotally mounted tool comprising a second clamping surface, said flange being able to assume a first tool clamping position in which the attachment surfaces of the tool are clamped between the first and second clamping surfaces and a second mounting / dismounting position of the tool in which its second surface the clamping surface is moved away from the first clamping surface of the clamping body.

• une première branche élastiquement déformable, en partie solidaire de la bride de serrage ;
• une deuxième branche élastiquement déformable, dirigée vers le haut, comprenant une extrémité susceptible de pénétrer dans ladite rainure de retenue, et une partie susceptible de coopérer avec le bord inférieur de ladite rainure de retenue lorsque l'outil pivote ; et
• au moins une partie angulaire située entre la première et la deuxième branche.

This fastening system is characterized in that it further comprises a tool retaining member comprising a plurality of blades, each blade comprising:

• a first elastically deformable branch, partially integral with the clamping flange;
• a second upwardly-adjustable elastically-deformable leg including an end capable of penetrating into said retaining groove, and a portion engageable with the lower edge of said retaining groove as the tool pivots; and
• at least one angular portion located between the first and the second branch.

It is understood that, thanks to the elasticity of the first and second branches, it is possible to proceed with the introduction and removal of the folding tool from the front face of the folding machine. The removal also requires cooperation between a portion of the second branch and the lower groove edge of the tool. This cooperation occurs when the operator pulls the tool towards him, thus causing it to pivot around his upper edge in contact with the clamping face of the tool spacer.

In addition, unlike the retaining member of US Pat. No. 5,022,256, which comprises a rigid piece of substantial thickness, the retaining member of the fastening system according to the invention comprises two elastically deformable arms which make it possible to limit the spacing of the flange from the clamping face of the spacer when mounting / dismounting the tool.

Advantageously, when the clamping flange is brought into the disassembly position of the tool, the end of the second branch of the retaining member is likely to remain engaged in said groove in order to retain the tool and to avoid any fall of the latter on the lower die of the press brake.

Once the flange in disassembly position, the user can remove the tool by pulling it towards him so as to rotate it. Under the effect of the pivoting of the tool, the assembly constituted by the two branches is capable of deforming so that the end of the second branch, which previously held the tool, can disengage from said groove restraint.

According to a particular embodiment of the invention, the end of said second branch forms an angle with the current part thereof and / or the upper edge of the retaining groove is chamfered. Said end can thus disengage more easily from said groove.

Advantageously, when the flange is brought into its clamping position, said retaining member is able to exert on the tool a vertical component force in order to bring the tool into abutment against the tool spacer. This allows the tool to be correctly positioned before tightening. The user no longer has to perform this task and the risk of accident is thereby reduced.

Preferably, the end of said second branch is capable of abutting against the upper edge of said retaining groove irrespective of the position of the flange. This retains the tool when the flange is loosened and exert a force on the tool during tightening.

More preferably, the end of said first branch of the retaining member is integral with the outer surface of the flange, opposite said second clamping surface.

Such an arrangement facilitates deformation of said first branch during tightening and / or during assembly / disassembly of the tool.

Advantageously, the clamping clamp of the fastening system according to the invention comprises on its inner surface, that is to say the surface of the flange facing the tool spacer, a groove. This groove extends in the direction of the pivot axis of the flange and is adapted to receive the end of the second branch during disassembly of the tool, when it pivots. This allows to retain the second branch and thus avoid unnecessary deformation of the retaining member during removal of the tool. This also makes it possible to limit the spacing of the flange relative to the clamping face of the spacer when mounting / dismounting the tool.

A device according to the invention makes possible the introduction or the frontal removal of a tool on the upper deck, but does not prevent to proceed to a side assembly / disassembly. In this case, the user slides the tool between the clamping surface of the tool spacer and the retaining member, so that the ends of said second branches can penetrate into said retaining groove. The repeated use of the fastening system can create a slight height shift of said ends relative to each other, which is an inconvenience during lateral mounting of the tool. To solve this additional problem, the end of each second branch has an upper edge of rounded shape, so that the tool can easily slide from one branch to another when they are not all at the same height.

• les figures 1A et 1B déjà décrites montrent un système de fixation d'outil de pliage de type connu en position serrée et en position de montage/démontage ;
• la figure 2 montre un système de fixation d'un outil selon l'invention, en coupe transversale, ledit outil étant installé non serré ;
• la figure 3 montre le même système de fixation, ledit outil étant serré ;
• la figure 4 montre le système de fixation lorsque ledit outil est en cours d'enlèvement ;
• la figure 5 est une vue en élévation d'un mode préféré de réalisation de l'organe de retenue.

Other features and advantages of the invention will be better understood on reading the description which follows, of a preferred embodiment of the invention. The description refers to the appended figures in which:

• FIGS. 1A and 1B already described show a known type of folding tool fixing system in the tight position and in the mounting / dismounting position;
• Figure 2 shows a fastening system of a tool according to the invention, in cross section, said tool being installed not tight;
• Figure 3 shows the same fastening system, said tool being tightened;
• Figure 4 shows the fastening system when said tool is being removed;
• Figure 5 is an elevational view of a preferred embodiment of the retainer.

Referring first to Figure 2, we will describe the entire attachment system of the tool. In this figure 2, there is the upper apron 10 of the press brake, the tool spacer 12 with its lower portion 14 of reduced width defined by the shoulders 16 and 18, the lower portion 14 defining one of the clamping faces 14a . We also find the flange 20, clamping with its upper part 30 and its lower end 42. It shows the pivot axis 22 of the clamp 20, as well as pushers 28 for controlling the pivoting of each flange about the axis 22. The embodiment of the shaft 22, and flange pivot control means can be any, by example of the type shown in Figures 1A and 1B.

In the fastening system shown, the shoulders 16 and 18 which define the lower portion 14 of the spacer 12 are of the same size and two pushers 28 are provided, so that two flanges can be mounted on either side of the 12. This allows the user to proceed to the mounting of the tool 34 regardless of its position relative to the system.

It is important to observe now that the flange 20 at its lower end 42, does not include the retaining pin 44 of Figure 1A.

In Figure 2, there is also shown the folding tool 34 with its attachment heel 36 and its retaining groove 38 having an upper edge 38a and a lower edge 38b. The attachment heel 36 has two attachment surfaces 36a and 36b respectively adapted to cooperate with the clamping surface 14a of the tool spacer and the clamping surface of the clamp 20. Said groove 38 is located under the fastening surface 36b adapted to cooperate with the clamping surface of the flange 20.

In the embodiment described, the lower part of the flange 20 in its inner face turned towards the tool spacer, has an insert which protrudes from the inner surface 43 and which defines a clamping surface 40 fulfilling the same function as the clamping surface of the flange shown in FIG. 1A.

It is understood that the flange 20 is pivotable between a first fastening position in which the bead 36 of the tool is clamped between the clamping surface 14a of the extension 14 of the tool spacer and the clamping surface 40 of the flange 20, and a second position of the flange 20 for mounting / dismounting the folding tool 34 in which the clamping surface 40 is spaced from the heel 36 of the tool.

According to the invention, the retention of the folding tool is obtained by a retaining member bearing the general reference 54 and shown in greater detail in FIG. 5. This retaining member 54 consists of Preferably, by a sheet of elastically deformable sheet 56 in which are defined elastically deformable blades 58. The elastically deformable blades 58 are substantially identical and aligned with each other, and are separated from each other by substantially parallel slots 60. The end each blade 58 intended to penetrate into the groove 38 of the tool 34 preferably has a rounded shape.

The width I of each elastically deformable blade is determined in relation to the lengths of the folding tools themselves, according to the length of the folding machine, so that each blade 58 is applied only on the heel of a single folding tool.

As best shown in FIG. 2, each blade 58 comprises: a first elastically deformable leg 58a whose end 59 which is formed by the non-slotted portion of the elastically deformable sheet, is fixed by any suitable means to the outer surface 41 of the flange 20, opposite the clamping surface 40; an angular portion 58b and; a second branch 58c elastically deformable, directed upwards and comprising an end 58d forming an angle α with the current part of the branch, so that this end 58d is substantially parallel to the bottom of the groove 38 when the second branch 58c is there engaged. As shown in FIG. 2, when the tool 34 is installed loosely, the end 58d of the second leg 58c abuts the upper edge 38a of the retention groove 38 so as to prevent the tool from falling. 34, and the first leg 58a is substantially pressed against the outer surface 41 of the end 42 of the flange 20. When tightening the tool 34, between the first and second clamping surfaces 14a and 40, said first leg 58a is deformed and a part of this branch is detached from the outer surface 41 of the flange 20. In opposing the deformation, the first elastically deformable branch 58a contributes to a vertical component force exerted on the tool for abutment against the lower portion 14 of the tool spacer 12, since the end 58d of the second leg 58c pushes on the upper portion 38a of the groove 38. The tool 34 is thus positioned suitably before tightening, as shown in FIG.

With reference to FIG. 4, when the flange 20 is in the disassembly position, the user pulls the tool along the arrow R so as to pivot it around its upper edge in contact with the clamping surface 14a. the spacer 12. The lower portion 38b of the retaining groove 38 then pushes the current portion of the second leg 58c. The first branch 58a then deviates slightly from the outer surface 41 of the flange. Under the combined effect of the force exerted by the lower part 38b of the groove and the deformation of the first leg 58a, which seeks to regain its initial position, the end 58d of the second leg 58c disengages from the upper part 38a of the groove 38. For said end can disengage more easily from the groove, a chamfer is provided on the upper portion 38a thereof.

Once said end 58d is disengaged, the user only has to pull the tool 34 downwards in the direction T. It is possible to provide a groove 70 made on the inner surface 43 of the flange 20 and extending in the direction of the pivot axis of the flange, wherein the end 58d of the second leg 58c will be housed during removal of the tool. Thus, the blade 58 will not be driven during this withdrawal, which has the advantage of avoiding any unnecessary deformation of the latter.

To set up a new tool 34, the user inserts the latter endally and from the bottom, the first and second branches then deform so as to allow the tool to pass, then the end 58d of the second branch 58c comes to penetrate in the retaining groove 38, as shown in Figure 2. The tool 34 is then held waiting to be tightened.

Claims (11)

1. A fixing system for fixing a bending tool (34), said tool (34) having two fixing surfaces (36a, 36b) for fixing by clamping, and a retaining groove (38) situated beneath one of the fixing surfaces, the groove presenting a top edge (38a) and a bottom edge (38b), said system comprising a clamping body presenting a first clamping surface (14a) suitable for co-operating with one of the fixing surfaces (36a, 36b) of the tool (34), and a pivotally-mounted tool clamp (20) having a second clamping surface (40), said clamp (20) being capable of taking up a tool-clamping first position in which the fixing surfaces (36a, 36b) of the tool (34) are clamped between the first and second clamping surfaces (14a, 40), and a tool mounting and/or dismounting second position in which the clamping surface (40) of the clamp is spaced apart from the first clamping surface (14a) of the body, said system being characterised in that it further comprises a tool-retaining member (54) comprising a plurality of blades (58), each blade comprising:

   - a first elastically-deformable branch (58a) secured in part to the clamp (20);

   - a second elastically-deformable branch (58c) directed upwards and having an end (58d) suitable for penetrating into said retaining groove (38), and a portion suitable for co-operating with the bottom edge (38b) of said retaining groove (38) when the tool (34) pivots; and

   - at least one angled portion located between the first and second branches.
2. A fixing system according to claim 1, characterised in that:

   - when the clamp (20) is brought into the tool-dismounting position, the end (58d) of the second branch (58c) is suitable for remaining engaged in said retaining groove (38); and

   - when the clamp (20) is in the tool-dismounting position, the assembly constituted by the two branches (58a, 58c) is suitable for deforming under the effect of the tool (34) pivoting so that the end (58d) of the second branch can become disengaged from said retaining groove (38).
3. A fixing system according to claim 1 or claim 2, characterised in that the end (58d) of said second branch (58c) forms an angle (α) with the main portion thereof.
4. A fixing system according to any one of claims 1 to 3, characterised in that said top edge (38a) of the retaining groove (38) is chamfered.
5. A fixing system according to any one of claims 1 to 4, characterised in that when the clamp (20) is brought into its clamping position, said retaining member (54) is suitable for exerting a force having a vertical component on the tool (34).
6. A fixing system according to any one of claims 1 to 5, characterised in that the end (58d) of said second branch (58c) is suitable for coming into abutment against the top edge (38a) of said retaining groove (38) whatever the position of the clamp (20).
7. A fixing system according to any one of claims 1 to 6, characterised in that the clamp (20) has an outside surface (41) that is opposite said second clamping surface (40), and the end (59) of said first branch (58a) is secured to the outside surface (41) of the clamp (20).
8. A fixing system according to any one of claims 1 to 7, characterised in that the end (58d) of said second branch (58c) presents a top edge of rounded shape.
9. A fixing system according to any one of claims 1 to 8, characterised in that the clamp (20) has a groove (70) in its inside surface (43), said groove extending along the direction of the clamp pivot axis and being suitable for receiving the end (58d) of the second branch (58c) while the tool (34) pivots.
10. A fixing system according to any one of claims 1 to 9, characterised in that said retaining member (54) is made out of elastically-deformable sheet material (56) with said blades (58) being substantially aligned with each other.
11. A fixing system according to claim 10, characterised in that said blades (58) are separated from one another by parallel slots (60).

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