EP1449599A1 - 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 fixing system for the assembly and disassembly of a folding tool on the upper deck of a Press brake.

Press brakes are used for forming sheet materials and for this purpose include one or more tools commonly called punches attached to the movable deck of the machine by a fastening system or tool holder and, opposite these tools, a or more V-shaped dies fixed on the upper edge of the deck bottom of the press brake.

By arranging the sheet to be formed on the matrix and causing lowering the punch by a predetermined amount, the bending the sheet metal at the desired angle.

In addition, depending on the type of forming and the size of this forming to be performed on sheet materials, the tool used is different. he it is therefore necessary to be able to disassemble the tool from the upper apron, i.e. of the fixing system to replace it with another more adapted.

As is well known, the attachment of the tool which comprises a fixing heel is produced using a pivotally mounted flange which can occupy a first tool clamping position or a second spread position allowing the tool to be changed.

We also understand that the folding tools are relatively heavy. It is therefore very desirable to keep the tool on the clamp even when it is in the loose position so to avoid any risk of the tool falling on the matrix of the lower deck arranged next to this tool.

In French patent application 00 07 415 in the name of the Applicant, an embodiment of a tool holder is described or tool attachment system that allows efficient control of the pivoting of the clamp as well as the retention of the tool after loosening of the flange.

In Figures 1A and 1B attached, there is shown the mode of realization of the tool fixing system described in the request for patent mentioned above. In these figures, the apron is shown movable upper 10 and the tool spacer 12 fixed by any means suitable on the upper apron 10. The tool spacer has a lower part 14 of reduced thickness, defined by two shoulders 16 and 18.

The fastening system also includes a flange clamp 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 part 26 of the flange 20. To control the pivoting of the flange 20 around the axis defined by the heads of the swiveling screws 22, can use pushers 28 one end of which acts on the end upper 30 of the flange 20 and whose second end cooperates with a rotary cam 32 mounted in the tool spacer 12 in the direction longitudinal of the deck. In this embodiment, the cam 32, in the position shown in Figure 1A, causes the spacing of the part upper 30 of the flange, which corresponds to the clamping position. In however, in its position shown in Figure 1B, the cam 32 does not act more on the pushers 28 and, under the effect of an elastic system, the flange 20 takes the mounting-dismounting position of the tool shown on the Figure 1B.

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

In the clamping position shown in Figure 1A, the attachment surfaces 36a and 36b of the tool heel are clamped between the surface 14a for clamping 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 has a spoiler-shaped retaining means 44 which can penetrate the groove 38 in the heel of the tool 34. When the flange 20 is in the position clamp shown in Figure 1A, the spoiler 44 plays no role. On the other hand, when the lower end 42 of the flange is separated for occupy the assembly-disassembly position, the spoiler 44 remains partially engaged in groove 38, as shown in FIG. 1B, this which ensures the maintenance in the vertical direction of the tool 34 relative to tool spacer 12.

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

We understand that, because the tool cannot be put in place between the lower part of the tool spacer and the flange only laterally, i.e. by the ends of the flange, when the operator wants replace a tool which is mounted for example in the central part of the flange, it is necessary that this proceeds before disassembly tools arranged between the tool actually to be changed and one of the ends of the flange.

These relatively delicate operations of removing a plurality of tools significantly increase the changeover time the desired tool and therefore lead to a decrease in the productivity of the Press brake. The greater the frequency of tool change, the greater the loss of time.

We also know the attachment system of a tool folding described in US Patent 5,022,256 in the name of Machinefabriek Wila B. V .. This system also includes a tool spacer and a flange clamping, pivotally mounted around a horizontal axis parallel to the length of the apron, the pivoting of the flange being controlled by means of hydraulic cylinders.

In addition, the system includes a metal strip elastically deformable pivotally mounted around a horizontal axis parallel to the length of the bulkhead on the clamp and which has a first surface facing the clamp and a second surface opposite the lower part of the tool spacer. A piece rigid is fixed on the second surface, in the lower part of the strip metallic. This rigid part has in its lower part, a inclined surface, approaching the metal strip.

When the flange is spread to occupy the position of assembly / disassembly of the tool, the metal strip is separated from the flange and the upper edge of the rigid part cooperates with a shoulder practiced on the heel of attachment of the tool so as to prevent the fall of the tool.

When the flange is brought into the tool clamping position, the tool fixing heel is tightened on one side, by the lower part of the tool spacer and on the other, by the rigid piece which transfers the force exerted on it by the clamp.

The assembly constituted by the metal strip and by the piece rigid is therefore subjected to very high compressive stresses, which requires the use of materials to make the different parts, and fixing means for securing the parts together, capable of bear such constraints.

In order to reduce the constraints to which the said is subject together, it is provided, in US patent 5,022,256, to have a flexible plastic band between the clamp and the band metal, housed in a groove in the clamp. This solution then has the drawback of making the flange shape.

Furthermore, in this type of system, the metal strip elastically deformable is subject to compressive stresses high and regularly repeated which make him gradually lose his 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 surface of clamping present on the spacer on the one hand and a clamping surface present on the flange on the other hand, i.e. without intermediate element participating in the tightening, located between the flange and the tool, and on the other hand, a system that allows the front mounting and dismounting of tools on the upper deck, so that only the desired tool can be changed.

To achieve this object, according to the invention, the fixing system a folding tool, said tool comprising two fixing surfaces by clamp and a retaining groove located below one of the attachment and having upper and lower edges, includes a body clamp having a first clamping surface capable of cooperating with one of the attachment surfaces of the tool and a clamp 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 position of assembly / disassembly of the tool in which its second surface clamping distance from the first clamping surface of the body Tightening.

• 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 fixing 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 secured to the clamp;
• a second elastically deformable branch, directed upwards, comprising an end capable of penetrating into said retaining groove, and a part capable of cooperating with the lower edge of said retaining groove when the tool pivots; and
• at least one angular part located between the first and the second branch.

We understand that, thanks to the elasticity of the first and second branches, it is possible to set up and removal of the folding tool from the front of the machine folding. Withdrawal also requires cooperation between part of the second branch and the lower groove edge of the tool. This cooperation occurs when the operator pulls the tool towards him, doing so pivot around its upper edge in contact with the clamping face of the tool spacer.

In addition, unlike the patent retainer US 5,022,256 which comprises a rigid piece of substantial thickness, the retaining member of the fixing system according to the invention comprises two elastically deformable arms which limit the distance between the flange and the clamping face of the spacer during assembly / disassembly of the tool.

Advantageously, when the clamp is brought in tool disassembly position, the end of the second branch of the retaining member is capable of remaining engaged in said groove in order to hold the tool and prevent it from falling onto the die bottom of the press brake.

Once the flange is in the disassembly position, the user can remove the tool by pulling it towards it so as to do so swing. Under the effect of the pivoting of the tool, the assembly constituted by the two branches is liable to deform so that the end of the second branch, which until now retained the tool, can disengage from said retaining groove.

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

Advantageously, when the flange is brought into its position tightening, said retaining member is capable of exerting on the tool a vertical component force to bring the tool into abutment against the tool spacer. This allows the tool to be positioned correctly before to tighten. 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 likely to be in abutment against the upper edge of said groove retained whatever the position of the flange. This keeps the tool when the flange is loose and exert a force on the tool when Tightening.

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

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

Advantageously, the clamp of the fixing system according to the invention comprises on its inner surface, that is to say the surface of the flange opposite the tool spacer, a groove. This groove extends in the direction of the pivot axis of the flange and is suitable for receive the end of the second branch when disassembling the tool, when it rotates. This allows the second branch to be retained and thus avoiding any unnecessary deformation of the retaining member during tool removal. This also makes it possible to limit the spacing of the flange relative to the clamping face of the spacer when assembly / disassembly of the tool.

A device according to the invention makes it possible to set up or the front removal of a tool on the upper apron, but does not prevent proceed with side mounting / dismounting. In this case, the user slides the tool between the clamping surface of the tool spacer and the retained, so that the ends of said second branches can enter said retaining groove. Repeated use of fastening system can create a slight offset in height of said ends relative to each other, which is a nuisance when side mounting of the tool. To resolve this additional problem, the end of each second branch has an upper edge of rounded shape, so that the tool can slide easily from a branch to the other when the latter 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 characteristics 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:

• Figures 1A and 1B already described show a folding tool fixing system of known type in the clamped position and in the assembly / disassembly position;
• Figure 2 shows a tool attachment system according to the invention, in cross section, said tool being installed loose;
• Figure 3 shows the same fixing system, said tool being tightened;
• Figure 4 shows the fixing system when said tool is being removed;
• Figure 5 is an elevational view of a preferred embodiment of the retaining member.

Referring first to Figure 2, we will describe the entire tool attachment system. In this figure 2, we find 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 part 14 defining one of the clamping faces 14a. We also finds the flange 20, clamping with its upper part 30 and its lower end 42. The pivot axis 22 of the clamp 20, and pushers 28 for controlling the pivoting of each flange around the axis 22. The embodiment of the axis 22, and means for controlling the pivoting of the flange can be any, for example of the type shown in the 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 similarly dimension and two pushers 28 are provided, so that two flanges can be mounted on either side of the spacer 12. This allows the user to assemble the tool 34 whatever 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 spoiler 44 of the Figure 1A.

FIG. 2 also shows the folding tool 34 with its fixing heel 36 and its retaining groove 38 having a upper edge 38a and a lower edge 38b. The fixing heel 36 has two fixing surfaces 36a and 36b able to cooperate respectively with the clamping surface 14a of the tool spacer and the clamping surface of the flange 20. Said groove 38 is located under the fixing surface 36b able 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 facing the tool spacer, comprises an insert which protrudes from the interior surface 43 and which defines a surface clamp 40 fulfilling the same function as the clamping surface of the flange shown in Figure 1A.

It is understood that the flange 20 can pivot between a first fixing position in which the heel 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 surface clamp 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 having the general reference 54 and shown more in detail in FIG. 5. This retaining member 54 consists, of preferably by an elastically deformable sheet sheet 56 in which are defined elastically deformable blades 58. The blades elastically deformable 58 are substantially identical and aligned between them, and are separated from each other by slits substantially parallel 60. The end of each blade 58 intended to penetrate into the groove 38 of the tool 34 preferably has a shape rounded.

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

As best shown in Figure 2, each blade 58 comprises: a first elastically deformable branch 58a of which the end 59 which is formed by the unsplit part of the sheet elastically deformable, is fixed by any suitable means on the outer surface 41 of the flange 20, opposite the clamping surface 40; an angular part 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 groove 38 when the second branch 58c is engaged there. As shown in the figure 2, when the tool 34 is installed loose, the end 58d of the second branch 58c abuts against the upper edge 38a of the groove of retainer 38 so as to prevent the tool 34 from falling, and the first branch 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 branch 58a deforms and part of this branch comes off of the outer surface 41 of the flange 20. By opposing the deformation, the first elastically deformable branch 58a contributes to a vertical component force is exerted on the tool so that it comes into abutment against the lower part 14 of the tool spacer 12, because the end 58d of the second branch 58c comes to push on the part upper 38a of the groove 38. The tool 34 is thus positioned suitably before tightening, as shown in figure 3.

With reference to FIG. 4, when the flange 20 is in the position of dismantling, the user pulls the tool towards him according to arrow R so as to rotate it around its upper edge in contact with the surface of tightening 14a of the spacer 12. The lower part 38b of the groove retainer 38 then pushes the current part of the second branch 58c. The first branch 58a then deviates slightly from the surface outside 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 branch 58a, which seeks to return to its initial position, the end 58d of the second branch 58c disengages from the upper part 38a of groove 38. So that said end can disengage more easily from the groove, a chamfer is provided on the upper part 38a of the latter.

Once said end 58d disengaged, the user no longer has only pull the tool 34 downwards, in the direction T. It is possible to provide a groove 70 formed on the inner surface 43 of the flange 20 and extending in the direction of the pivot axis of the flange, in which the end 58d of the second branch 58c will come to be housed during removal of the tool. Thus, the blade 58 will not be driven during this shrinkage, which has the advantage of avoiding unnecessary deformation of the latter.

To install a new tool 34, the user inserts this last frontally and from below, the first and second branches then deform so as to let the tool pass, then the end 58d of the second branch 58c comes into the retaining groove 38, as shown in Figure 2. The tool 34 is then retained while waiting to be tight.

Claims (11)

System for fixing a folding tool (34), said tool (34) comprising two fixing surfaces (36a, 36b) by clamping and a retaining groove (38), located below one of the fixing surfaces, having an upper edge (38a) and a lower edge (38b), said system comprising a clamping body having a first clamping surface (14a) capable of cooperating with one of the fixing surfaces (36a, 36b) of the tool ( 34) and a clamping flange (20) of the tool pivotally mounted, and comprising a second clamping surface (40), said flange (20) being able to assume a first clamping position of the tool (34) in which the attachment surfaces (36a, 36b) of the tool (34) are clamped between the first and second clamping surfaces (14a, 40) and a second mounting / dismounting position of the tool (34) in which its surface clamping (40) is spaced from the first clamping surface (14a) of the body, said system being characterized in that ' it further comprises a tool retaining member (54), comprising a plurality of blades (58), each blade comprising: a first branch (58a) elastically deformable, partially integral with the clamping flange (20); a second branch (58c) elastically deformable, directed upwards, comprising an end (58d) capable of penetrating into said retaining groove (38), and a part capable of cooperating with the lower edge (38b) of said retaining groove (38) when the tool (34) pivots; and at least one angular part located between the first and the second branch. Fastening system according to claim 1, characterized in that : when the flange (20) is brought into the disassembly position of the tool (34), the end (58d) of the second branch (58c) is capable of remaining engaged in said retaining groove (38); and when the flange (20) is in the disassembly position of the tool (34), the assembly constituted by the two branches (58a, 58c) is liable to deform under the effect of the pivoting of the tool (34) so that the end (58d) of the second branch can disengage from said retaining groove (38). Fastening system according to claim 1 or 2, characterized in that the end (58d) of said second branch (58c) forms an angle (α) with the current part thereof. Fastening system according to any one of claims 1 to 3, characterized in that said upper edge (38a) of the retaining groove (38) is chamfered. Fastening system according to any one of claims 1 to 4, characterized in that when the flange (20) is brought into its clamping position, said retaining member (54) is capable of exerting on the tool (34 ), a force with a vertical component. Fastening system according to any one of claims 1 to 5, characterized in that the end (58d) of said second branch (58c) is capable of abutting against the upper edge (38a) of said retaining groove (38) whatever the position of the flange (20). Fastening system according to any one of claims 1 to 6, characterized in that the flange (20) has an outer surface (41), opposite to said second clamping surface (40), the end (59) of said first branch (58a) being integral with the outer surface (41) of the flange (20). Fastening system according to any one of claims 1 to 7, characterized in that the end (58d) of said second branch (58c) has an upper edge of rounded shape. Fastening system according to any one of claims 1 to 8, characterized in that the clamping flange (20) comprises on its internal surface (43), a groove (70) which extends in the direction of the axis pivoting flange and which is adapted to receive the end (58d) of the second branch (58c) when the tool (34) pivots. Fastening system according to any one of claims 1 to 9, characterized in that said retaining member (54) consists of an elastically deformable sheet (56), said blades (58) being substantially aligned with one another. Fastening system according to claim 10, characterized in that said blades (58) are separated from each other by parallel slots (60).

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