EP1396293B1 - Fixing system for a bending tool - Google Patents

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 request for French patent FR-A-2,809,976 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 .

On the Figures 1A and 1B appended, there is shown the embodiment of the fastening 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 part 14 of reduced thickness and 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 on the Figure 1A , causes the separation of the upper part 30 of the flange, which corresponds to the clamping position. On the other hand, in its position represented on the Figure 1B , the cam 32 no longer acts on the pushers 30 and, under the effect of an elastic system, the flange 20 assumes the mounting position-disassembly of the tool shown on the Figure 1B .

The tool 34 comprises at its upper part a fixing heel 36 which has a first fixing face 36a, a second fixing face 36b parallel to the first fixing face and a retaining groove 38.

In the clamping position shown on the Figure 1A , the attachment surfaces 36a and 36b of the heel of the tool are clamped between the clamping face 14a of the end 14 of the tool spacer and the clamping face 40 of the lower part 42 of the flange 20.

In addition, at its lower end 42, the flange comprises a spoiler retaining means 44 which can penetrate into the groove 38 of the heel of the tool 34. When the flange 20 is in the clamping position shown in FIG. Figure 1A , the spoiler 44 plays no role. On the other hand, when the lower end 42 of the flange is spaced apart to occupy the position of assembly-disassembly, the spoiler 44 remains partially engaged in the groove 38, 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 position of assembly-disassembly, the removal of the tool 34 can be achieved only by the longitudinal ends of the flange 20 by sliding the heel 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.

An object of the present invention is to provide a tool attachment system on the upper apron of a press brake which allows the mounting and the front dismounting of the tools on the upper deck, which effectively allows to change only the desired tool.

Another object of the invention is to provide a fastening system of the tool wherein the tool retaining means are simple and inexpensive to manufacture and easy to mount on the press.

To achieve this object, according to the invention, the fastening system of a folding tool, said tool comprising two parallel clamping attachment surfaces and a retaining groove, comprises a clamping body having a first clamping surface adapted to cooperating with one of the attachment surfaces of the tool and a clamping flange of the pivotally mounted tool comprising a second clamping surface, said clamp being able to assume a first clamping position of the tool in which the fastening surfaces of the tool tool are clamped between the first and second clamping surfaces and a second mounting / disassembling position of the tool in which its clamping surface is spaced apart from the first clamping surface of the clamping body.

This fastening system is characterized in that it further comprises a retaining piece of the tool comprising a plurality of elastically deformable blades parallel to each other and arranged in the same plane, each blade comprising a first end secured to the clamping body. , a running part arranged in such a way that it is applied against the first attachment face of the tool and a second end comprising at least a first part angular towards the tool relative to the current part and a second part angulated in opposite direction so that said angulated portions, when said blade is at rest, are held elastically in the groove of the tool and that, when the flange is in the loading / unloading position, the current portion of the blade can deform elastically to allow introduction or extraction of said angular portions of the elastically deformable blades in or out of said groove.

It is understood that, thanks to the presence of resilient retaining blades which terminate in the two angled portions, it is possible to proceed with the introduction and removal of a bending tool from the front face of the machine. folding. Indeed, after bringing the flange into its position of assembly / disassembly, we can implement or remove the tool by elastic deformation of the running part of the blades under the effect of cooperation in one direction or the other one or other of the angled portions of the end of the resilient blade with the attachment of the attachment of the tool. In addition, this elastic retaining system ensures a retention of the tool after loosening the flange as effective as in previous systems.

In addition, it is clear that the cost of manufacturing and mounting the retaining piece is reduced since it is preferably a simple sheet which is cut and folded to obtain the different elastic blades with their two angled parts. able to penetrate into the groove of the tool.

Finally, it is understood that the presence in two angled parts allows easy introduction and extraction of the retaining means in and out of the retaining groove, which avoids the risk of introduction of stresses or deformations of the elastic blades that would be unfavorable the durability of the restraint system.

Preferably, when a tool is in the fixing position, the current part of the elastic blade bears on the attachment surface of the tool and the first angulated portion is in contact with the chamfer which connects the attachment surface of the tool. the tool and the upper wall of the groove.

More preferably, each elastically deformable blade further comprises, beyond said second angulated portion, a connecting portion and an alignment portion disposed at the end of the connecting portion, said alignment portion extending substantially parallel to the current portion of the blade facing at least said second angled portion, said alignment portion being adapted to penetrate into an alignment groove formed in the lower face of the flange and parallel to the axis of pivoting thereof.

According to a preferred embodiment, said alignment groove comprises an alignment wall which cooperates with the alignment portion of the elastically deformable blades when the flange is in its loading / unloading position.

It is understood that, thanks to the presence of the alignment wall formed in the flange alignment groove, the alignment portions of the elastically deformable blades can be effectively all aligned and so are the angular portions of the flanges. elastically deformable blades, which greatly facilitates the introduction or extraction of the folding tool.

• les figures 1A et 1B déjà décrites montrent un système de fixation d'outil de pliage de type connu en position active et en position de repos ;
• la figure 2 est une vue en élévation de l'ensemble d'un système de fixation d'outil selon l'invention ;
• la figure 3 est une vue de détail montrant l'extrémité inférieure des lames de retenue lorsque la bride est en position de serrage ;
• la figure 4 est une vue de détail montrant l'extrémité inférieure de la lame de retenue lorsque la bride est dans la position de montage/démontage ; et
• 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 appear better on reading the following description of an embodiment of the invention given by way of non-limiting example. The description refers to the appended figures, in which:

• the Figures 1A and 1B already described show a known type of folding tool attachment system in the active position and in the rest position;
• the figure 2 is an elevational view of the assembly of a tool attachment system according to the invention;
• the figure 3 is a detail view showing the lower end of the retaining blades when the flange is in the clamping position;
• the figure 4 is a detail view showing the lower end of the retaining blade when the flange is in the mounting / disassembling position; and
• the figure 5 is an elevational view of a preferred embodiment of the retainer.

Referring first to the figure 2 , we will describe the entire attachment system of the tool. On 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. There is also the flange 20, 20 'clamping with its upper portion 30 and lower end 42. On the figure 2 schematically shows the pivot axis 22, 22 'of the clamps 20, 20' and actuators 28, 32 for controlling the pivoting of each flange about the axes 22, 22 '. The embodiment of the axes 22, 22 'and flange pivot control means can be arbitrary, for example of the type shown in the drawings. Figures 1A and 1B .

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

On the figure 2 the folding tool 34 has also been shown with its fixing heel 36 and its retaining groove 38. The fixing heel 36 has two fixing faces 36a and 36b capable of cooperating with the clamping face 14a of the spacer tool and the clamping face of the flange as will be explained.

In the embodiment described, the lower part of the flange 42 in its face facing the tool spacer comprises two longitudinal rod-shaped inserts 50 and 52 which define a clamping surface fulfilling the same function as the surface of clamping 40 of the flange 20 shown in FIG. Figure 1A .

It is understood that the flange 20 can pivot between a first fastening position in which the heel 36 of the tool is clamped between the extension 14 of the tool spacer and the clamping surface formed by the rods 50 and 52 and a second position of the flange 20 of assembly / disassembly in which the clamping surfaces 50, 52 are spaced apart from the heel 36 of the folding tool.

According to the invention, the retention of the folding tool is obtained by a retainer with the general reference 54 and shown in more detail on the figure 5 . This retention member 54 is preferably constituted by an elastically deformable metal plate 56 in which are defined elastically deformable blades 58. Each elastically deformable blade 58 is separated from the adjacent blades by a slot 60.

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 by the figure 2 each blade 58 has a first attachment end 58a secured by any suitable means 62 to the tool spacer 12, a running portion 58b and a retaining end 58c. At rest, that is to say when the blade 58 is not deformed, and when a tool is mounted, its current portion 58b is applied against the attachment face 36a of the heel 36 of the tool. The retaining end 58c of each blade 58 is disposed in such a way that it can penetrate into the groove 38 of the heel of the tool when it is in the attachment position on the tool spacer 12.

As the Figures 3 and 4 , the retaining portion 58c of each blade 58 has a first angular portion 64 which is for example an angle of the order of 45 ° relative to the direction of the running portion 58b of the blade. The angulation is such that this portion can enter the groove 38 of the heel of the folding tool. The retaining portion also comprises a second angled portion 66 in the opposite direction, so that the set of angled portions 64 and 66 form an open V of vertex A. The fold 68 which connects the flat current portion 58b to the first angled portion 64 is defined such that, at rest, the chamfer 70 which connects the attachment face 36a of the heel of the tool to the upper wall 72 of the groove 38, is supported on the first end of the angled portion 64. Of course, the angled portions 64, 66 are defined such that the angled portions can enter fully into the groove 38.

The lower end 58c of each blade 58 further comprises an alignment portion 76 substantially parallel to the running portion 58b of the blade and connected to the end of the second angled portion 66 by a substantially horizontal connecting portion 78. As shown by Figures 3 and 4 , the lower end 42 of the flanges 20, 20 'is provided with a longitudinal groove 80 formed in the lower face 20a of the flange and extending along the length of the flange. The alignment groove 80 is adapted to receive the end 76a of the alignment portion 76. The width l 'of the alignment groove 80 is such that, when the flange is in the clamping position, the portion of the alignment portion 80 alignment 76 is not in contact with any of the vertical walls 80a, 80b of the alignment groove and that, when the flange is in the assembly / disassembly position shown in FIG. figure 4 the end of the alignment portion 76 is applied against the vertical wall 80a of the groove 80, the wall closest to the heel of the tool.

It is understood that when the flange 20 is in its clamping position as shown in FIG. figure 3 , the current portion 58b transmits to the fixing face 36a of the heel of the tool the entire clamping force produced by the attachment surfaces 50 and 52 of the flange.

When the flange 20 is brought into its assembly / disassembly position as shown in FIG. figure 4 and that no force is applied to the folding tool 34, the stiffness of the blade 58 is sufficient so that its running portion 58b is held against the attachment face 36a of the heel of the tool and that the angled portions 64 and 66 remain engaged in the groove 38 of the heel of the tool. In other words, the stiffness of the blade 58 is sufficient to compensate for the weight of the tool. Thus in this position of the flange 20 is obtained effective retention of the tool.

When a downward force F is applied to the tool to obtain disassembly, the upper chamfer 70 of the groove 38 of the tool acts on the beginning of the upper angulated portion 64 causing by elastic deformation the gap of the elastic blade and the progressive exit of the angulated portions out of the groove 38. This result is obtained of course thanks to the angulation of the portion 64. When the chamfer 70 comes into contact with the apex A of the two angular portions, the effect no longer exists and the tool can be removed.

It will be understood that, when it is desired to implement the tool, the upper outer corner 82 of the heel 36 of the tool comes into contact with the lower portion of the angled portion 66 of the blade 58. upper wedge, preferably chamfered, 82 causes progressive separation of the entire blade 58 until the vertex A angulated portions 64 and 66 comes into contact with the attachment face 36a of the heel of the tool . When the tool has been lifted sufficiently so that the vertex A angular portions comes opposite the upper portion of the groove 38 as the tool is lifted, the angled portions 64 and 66 penetrate the groove 38 until the tool 34 arrives in its attachment position shown on the figure 4 . In this position, the angled portions 64, 66 fully fulfill their restraint function. To ensure the fixing of the tool on the upper deck, it is then sufficient to control the pivoting of the flange 20 to bring it back into the position shown on the drawing. figure 2 .

We will now explain the function of the alignment portion 76 of the retaining end 58c of the elastically deformable blades 58. The end 76a of this portion enters the longitudinal groove 80 formed in the underside of the flange. As has already been briefly explained, this end 76a does not come into contact with any of the vertical faces 80a and 80b of the groove when the flange is in its clamping position shown in FIG. figure 3 . On the other hand, when the flange is brought into its assembly / disassembly position shown on the figure 4 the end 76a of the alignment portion 76 engages the wall 80a of the groove 80. Thus, all the alignment ends 76 of the blades 58 are aligned with the position of the wall 80a. As a result, the vertices A angular portions 64, 66 of each blade are also aligned, which facilitates the introduction or extraction of the tool since all these A vertices are aligned.

This alignment of the vertices at the time of installation of the tool avoids the introduction of significant stresses in deformable blades whose vertices would not be properly spaced from the clamping face 14a.

On the figure 5 which represents a preferred embodiment of the retaining member 54, there is shown in the zone Z the portions of the elastically deformable blades 58 which deform elastically when insertion or extraction of the angled portions 64 and 66 of these blades in the groove 38 of the heel of the folding tool 34.

Claims (5)

1. A system for fixing a bending tool (34), said tool comprising two parallel surfaces for fixing by clamping and a retaining groove (38), said system comprising a clamping body (14) having a first clamping surface capable of cooperating with one of the fixing surfaces of the tool and a pivotably mounted tool clamp (20) and comprising a second clamping surface, said clamp being able to assume a first tool clamping position in which the fixing surfaces of the tool are clamped between the first and second clamping surfaces and a second position for mounting/dismounting the tool, in which position its clamping surface is separated from the first clamping surface of the body, said system being characterized in that it further comprises a member (54) for retaining the tool comprising a plurality of mutually parallel elastically deformable blades (58) positioned in the same plane, each blade comprising a first end (58a) firmly secured to the clamping body, a running part (58b) positioned in such a way that, at rest, it is applied against the first fixing face of the tool and a second end (58c) including at least a first part (64) angled toward the tool with respect to the running part and a second part (66) angled in the opposite direction so that said angled parts, when said blade is at rest, are held elastically in the groove (38) of the tool (34) and so that when the clamp is in the loading/unloading position, the running part of the blade may deform elastically to allow said angled parts (64, 66) of the elastically deformable blades (58) to be introduced into or extracted from said groove (38).
2. The fixing system according to claim 1, characterized in that, when a tool (34) is in the fixing position, the running part (58b) of the elastic blade (58) bears against the fixing surface of the tool (34) and in that the first angled portion (64) is in contact with the chamfer (70) which connects the fixing surface (36a) of the tool and the upper face (72) of the groove.
3. The fixing system according to any one of claims 1 and 2, characterized in that each elastically deformable blade (58) further comprises beyond said second angled portion (66), a connecting portion (78) and an alignment portion (76) positioned at the end of the connecting part, said alignment portion (76) extending substantially parallel to the running part of the blade (58) facing at least said second angled portion (66), said alignment part being capable of penetrating into an alignment groove (80) formed in the lower face (20a) of the clamp (20) and parallel to the axis of pivoting thereof.
4. The fixing system according to claim 3, characterized in that said alignment groove (80) comprises an alignment wall (80a) which cooperates with the alignment portion (76) of the elastically deformable blades (58) when the clamp (20) is in its loading/unloading position.
5. The fixing system according to any one of claims 1 to 4, characterized in that said retaining part (54) is formed by an elastically deformable metal sheet (56) in which said blades (58) are separated from each other by parallel slots (60).

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