FR3009694A1 - OPTIMIZED PROFILE-CAM PADDING PRESS TOOLING FOR MOVING A TOOL SLIDER - Google Patents

Abstract

The present invention relates to a profiled cam pressing press tool optimized for moving a tool slide. According to the invention, the cam (4) of the vertically movable part (2, 3) comprises first, second and third inclined ramps (14, 15, 16) and able to bear successively on the roller (12) of the mobile body (7) during the vertical descent of the movable part (2,3) to allow the sliding body (7) to slide to a sheet metal part respectively following a first launching stroke (a) during which the moving body ( 7) has a relatively low speed of movement relative to that of the moving part (2, 3), a second approach stroke during which the movable body (7) has a movement speed substantially equal to that of the moving part (2,3) and a third working stroke (c) during which this body has a relatively low speed of movement relative to that of the movable part (2,3). The invention finds application for parts of motor vehicle bodies.

Description

The present invention relates to a stamping press tooling for carrying out technical operations on a sheet metal part. BACKGROUND OF THE INVENTION Figures 1 to 4 show a stamping press tooling comprising a vertically movable portion 1 having an upper frame 2 integral with a press ram 3 and a cam 4 ramp 5 inclined relative to the vertical. The cam 4 ramp 5 is removably attached to the upper frame 2 by any suitable means, such as for example fixing screws. The press press tooling further comprises a slider 6, the body 7 is movably mounted to slide guided in rectilinear translation on a sole 8 secured to a fixed lower frame 9. The movable body 7 of the slider 6 is bilaterally guided relative to the sole 8 by two rails 10 parallel to the direction of movement of the movable body 7 being spaced transversely from one another. The two slides 10 comprise two convergent faces inclined downwards to define a vee guiding the movable body 7 of the slider 6. The movable body 7 of the slider 6 carries at one of its ends a working tool 11 allowing perform technical operations on a sheet metal part P.

Each technical operation performed by the working tool 11 on the sheet metal part P may be a punching operation, but it is understood that depending on the type of working tool carried by the movable body 7, this technical operation could be for example a clipping operation of the sheet metal part P. Such a sheet metal part may be intended for the realization of a structural bodywork part of a motor vehicle. The movable body 7 of the slider 6 also carries, opposite the working tool 11, a roller 12 mounted to rotate about an axis AA 'transverse to the moving direction of the movable body 7. [ 0007] Figures 2 and 3 show a configuration in which the movable body 7 is displaceable in translation relative to the lower frame 9 in a horizontal direction, while Figure 4 shows a configuration in which the movable slider 7 is movable relative to the lower frame 9 in a direction inclined at an angle with respect to the horizontal. Referring to Figures 2 and 3, when the slider 3 and the upper frame 2 descend vertically from a high position, the ramp 5 of the cam 4 contacts the roller 12 of the movable body 7, which occupies a retracted position relative to the sheet metal part P, to cause the guided sliding of the movable body 7 to the sheet metal part P in a horizontal working direction D to reach the sheet metal part P to allow the working tool 11 to perform the punching operation. [0009] FIG. 4 shows the upper frame 2 and the press slide 3 having been lowered vertically to their lower position at which the ramp 5 of the cam 4 has moved the movable body 7, via the roller 12, to its advanced position along the working direction D inclined relative to the horizontal along the angle a to perform the punching operation of the sheet metal part P. [0010] Once the punching operation performed, the movable body 7 of the slider 6 is returned to its retracted position by a return spring 13, such as a gas cylinder. In this kind of stamping press tooling, the movable body 7 of the slider 6 is movable in the direction of work D horizontal or in the direction of work D inclined relative to the horizontal of the angle a, the angle y defined between the ramp 5 of the cam 4 and the working direction D is set at 50 °. Under these conditions, as soon as the movable body 7 of the slider 6 is moved by the ramp 5 of the cam 4 from its retracted position, the moving speed of the movable body 7 passes instantly from 0 to 0.84 times the speed of descent of the press ram 3 and thus of the cam 4 (considering the cotangent of the angle y of 50 ° = 0.84) and the speed of the press ram 3 at the moment of the contact of the ramp 5 of the cam 4 with the roller 12 is even higher than the stroke of the slider 6 is large. It then occurs a relatively violent shock on the movable body 7 of the slider 6 and its components including the roller 12 and the return spring 13, which can lead to their damage. The present invention aims to overcome the above disadvantage of known tools presses stamping. This object is achieved, according to the invention, thanks to a pressing press tooling comprising a vertically movable portion carrying a cam to at least one inclined ramp, a slide whose movable body carries a working tool to perform technical operations on a sheet metal part and a roller opposite the working tool cooperating with the cam of the vertically movable part to allow a guided sliding of the movable body to the sheet metal part on a fixed part in one direction forming an angle of inclination with respect to the horizontal or in a horizontal direction, characterized in that the cam of the vertically movable part comprises first, second and third ramps inclined relative to the direction of sliding of the movable body and adapted to come successively in support on the roller of the movable body during the vertical descent of the movable part to allow the sliding of the moving body towards the sheet metal part, from a retracted position of this body, respectively following a first launching stroke during which the movable body has a relatively low speed of movement relative to the descent speed of the moving part, a second stroke approach during which the movable body has a movement speed substantially equal to the lowering speed of the moving part and a third working stroke during which the movable body has a relatively low speed of movement relative to that of the moving part . [0016] Preferably, the angle of inclination of the second ramp is 45 °. Preferably, the inclination angles of the first and third ramps are 70 ° relative to the sliding direction of the movable body. The launching stroke of the movable body represents about 10% of its total stroke from its retracted position to its working position at which the working tool performs its technical operation, the approach stroke of the moving body represents about 80% of its total stroke and the moving body working stroke represents 10% of its total stroke. The movable body of the slider is returned to its retracted position by a return spring, such as a gas cylinder. According to an alternative embodiment, the three ramps are constituted by sections connected to each other. According to another embodiment, the three ramps have a curved profile. Advantageously, the upper part is a press slide. The invention will be better understood, and other objects, features, details and advantages thereof will appear more clearly in the explanatory description which follows with reference to the accompanying drawings given solely by way of example illustrating two Embodiments of the invention and in which: - Figure 1 is a perspective view of a slider for a stamping press tooling of the prior art; FIGS. 2 and 3 diagrammatically show a stamping press tooling with a displacement control cam of the slider of FIG. 1 in a horizontal direction from a position retracted to a working position of this slider; FIG. 4 diagrammatically represents a stamping press tooling with a displacement control cam of the slide of FIG. 1 in a direction inclined with respect to the horizontal, the slide occupying its working position; FIG. 5 represents a cam with profiled ramps according to the invention for moving a tool slide of a stamping press tool in a horizontal direction; - Figure 6 shows a profiled rail cam according to an alternative embodiment of the invention for moving a tool slide of a press stamping tool in a direction inclined relative to the horizontal; - Figures 7A to 7C show schematically the cam of Figure 5 cooperating with the slider to move it horizontally from its retracted position to its working position; FIGS. 8A to 8C show the cam of FIG. 6 cooperating with the slider to move it in a direction inclined relative to the horizontal from a retracted position to a working position; - Figure 9 shows an alternative embodiment of the profile of the ramp cam of the invention. The various constituent components of a stamping press tooling shown in Figures 5, 6, 7A-7C, 8A-8C and 9 common to those of the stamping press tooling described with reference to Figures 1. at 4 to perform the same functions carry the same references and will not be re-detailed. FIG. 5 represents a cam 4 of the invention intended to be removably attached to the upper frame 2 of FIG. 2 and which comprises, from bottom to top of the cam 4, a first lower ramp 14, a second intermediate ramp. 15 and a third upper ramp 16 succeeding each other being connected to each other so as to constitute three successive sections. The cam profile with ramps 14, 15, 16 of this figure is intended to cooperate with the slider 6 of Figures 7A to 7C so as to move the movable body 7 of the slider to the sheet metal part to work P next a working direction D parallel to the horizontal, the movable body 7 being guided in translation relative to the sole 8 of the lower frame 9 by the two vee rails 10 of Figure 6. [0027] Preferably, the lower ramps 14 and upper 16 of the cam 4 have the same angle of inclination 71 and y3 with respect to the horizontal direction of displacement D and preferably set at a value of 70 °, tandb the intermediate ramp 15 has a relatively inclination angle in the horizontal direction of displacement D preferably fixed at 45 °. Each of the ramps 14-16 has a predetermined length and can be considered as constituting the hypotenuse of a right triangle whose side adjacent to this hypotenuse extends in a horizontal direction. Thus, the side adjacent to the lower ramp 14 has a length a, the side adjacent to the intermediate ramp 15 has a length b and the side adjacent to the upper ramp 16 has a length c. The lengths a, b and c respectively correspond to three strokes of the movable body 7 of the slider 6 in the direction of work D from the retracted position O of the movable body 7. The first stroke of the moving body 7 linked to the lower ramp 14 is said launching this body to the workpiece P, the second stroke b linked to the intermediate ramp 15 is said to approach the movable body 7 to the workpiece P and the third race c linked to the upper ramp 16 is said to work during which the working tool 11 performs the punching operation of the sheet metal part P. The displacement of the movable body 7 of the slider 6 in the horizontal direction of work D will now be explained with respect to FIGS. 7A to 7C. During the vertical descent of the cam 4 with the upper frame 2 and the press slide 3 and as shown in Figure 7A, the lower ramp 14 contacts the roller 12 of the movable body 7 occupying its retracted position relative to the sheet metal piece P to cause the movement of this body along the launching stroke of the slider 6 and the angle y1 of 70 ° of the lower ramp 14 moves the movable body 7 of the slider 6 during the race a at a low speed by ratio to the vertical descent speed of the press ram. This speed of the moving body 7 thus increases from 0 to 0.36 times the speed of the press ram (for cotangent return 70 ° = 0.36). Thus, the launch phase or start of the movable body 7 of the slider is progressive, smoothly. Then, the intermediate ramp 15 of the cam 4 comes into contact with the roller 12 of the movable body 7 as shown in Figure 7B to move the body in the horizontal direction of work D to the sheet metal part P on the race of approach b and during this race, the speed of displacement of the slider 6 is substantially identical to that of the press slider 3 because the cotangent of the angle y 2 of 45 ° is equal to 1. [0035] Finally, the upper ramp 16 of the cam 4 comes into contact with the roller 12 of the movable body 7 as shown in Figure 7C to move the latter on the stroke c corresponding to the working phase (punching) of the sheet metal part P by the tool 11. During the stroke c, the speed of movement of the slide 6 becomes small compared to the speed of movement of the press slide 3, that is to say 0.36 times this speed (cotangente y3 = 0.36), which is a situation before ageuse in this phase of work. Preferably, the stroke a represents about 10% of the total stroke of the movable body 7 of the slider 6 from its retracted position to its advanced working position of the sheet metal part P, the stroke b of the movable body 7 represents approximately 80% of its total stroke and stroke c of this body represents about 10% of its total stroke. The embodiment of the cam 4 shown in Figure 6 is intended to cooperate with the slider 6 moving in a working direction D inclined at an angle with respect to the horizontal as shown in Figures 8A to 8C . According to this embodiment, there are three lower ramps 14, intermediate 15 and upper 16 succeeding from bottom to top of the cam 4 adjacent and defining sections connected to each other. The lower ramp 14 is inclined at an angle 71 preferably 70 ° relative to the inclined direction of displacement D of the slider 6, the intermediate ramp 15 is inclined by the angle y2 preferably 45 ° relative to in the direction cb inclined movement of the slider 6 and the upper ramp 16 is inclined by the angle y3 preferably 70 ° relative to the direction of irreplacement D of this slider. As for the ramps of FIG. 5, the ramps 14, 15, 16 of the cam 4 of FIG. 6 have a length defining hypotenuses of right triangles and the sides adjacent to these hypotenuses respectively define the launch race. from the slider 6 to the sheet metal part to be worked P, the approaching stroke b of this slider towards the piece P and the working stroke c of the slider to which the working tool 11 performs the punching operation of the piece P. [0041] Preferably, the launch stroke of the slider 6 represents about 10% of its total stroke from its retracted position to its advanced working position, the approach stroke b of this slider represents about 80% of its total stroke and the working stroke of the slider is approximately 10% of its total stroke. The displacement of the slider 6 along the inclined working direction D by the cam of FIG. 6 will be described with reference to FIGS. 8A to 8C. Figure 8A shows the situation in which the cam 4 is vertically lowered to a position such that the lower ramp 14 contacts the roller 12 of the movable body 7 of the slider 6 to move the latter along the working direction D towards the workpiece of sheet metal P on the race a. Given the value of the angle 71 of the lower ramp 14, the moving speed of the movable body 7 of the slider 6 is relatively small compared to the speed of movement of the press slide, that is to say 0 , 36 times the speed of the latter (cotangent 71 = 0.36), so that the launching or starting phase of the slider 6 is progressive. Then, as shown in Figure 8B, during the vertical descent of the cam 4, the intermediate ramp 15 contacts the roller 12 to move the movable body 7 of the slider 6 to the workpiece P according to the working direction D on the approach stroke b and taking into account the angle of inclination value y2 of the intermediate ramp 15, the slider 6 moves at a speed substantially identical to the vertical movement speed of the press slide (cotangent y2 = 1). Figure 8C shows the situation in which the upper ramp 16 of the cam 4 contacts the roller 12 to move the slider 6 along the working stroke c parallel to the direction of movement D to allow the working tool 11 to perform the punching operation of the sheet metal part P. During the stroke c, the speed of movement of the slider 6 becomes relatively low compared to the speed of movement of the press slide 3, that is to say 0.36 times the latter (cotangent y3 = 0.36), thus enabling the punching operation to be carried out in an advantageous situation. FIG. 9 represents an alternative embodiment of the profile of the ramps 14-16 of both the cam 4 of FIG. 5 and that of the cam 4 of FIG. 6. According to this variant embodiment, the profile of the three ramps is curved, that is to say that the connection to each other of the ramps 14, 15 and 16 is effected by curved parts. This curved profile of the ramps 14-16 makes it possible to move the slider 6, in a horizontal direction or inclined with respect to the horizontal, on the three races a of launching or starting of the slider towards the piece of sheet metal to be worked P, respectively. b of the slide towards this work piece and c of this piece as for the variants of the cams 4 of Figures 7A-7C and 8A-8C. The profiles of cams 4 described above of the invention are thus optimized to significantly reduce the effects of shock on the sliders of tools, which has the following consequences: - a reduction of the impact on the springs of reminder of the sliders and therefore a better reliability, - a shock reduction on the components of the sliders of tools including the roller, and therefore a better reliability of the slider, - a reduction in the effort required for the damping of the slider at the end of the stroke, - a reduction of the damping means in sizes and costs, - a reduction of shocks on the limit stops, which improves the reliability of the stamping tool, and - a reduction vibratory phenomena thereby improving the reliability of the stamping tooling.

Claims (8)

REVENDICATIONS1. Pressing press tooling comprising a vertically movable upper part (3) carrying a cam (4) to at least one inclined ramp, a slide (6) whose movable body (7) carries a working tool (11) for carrying out technical operations on a sheet metal part (P) and a roller (12) opposite the working tool (11) cooperating with the cam (4) of the vertically movable part (3) to allow guided sliding from the movable body (7) to the sheet metal part (P) on a fixed part (9) in a direction forming an inclination angle with respect to the horizontal or in a horizontal direction, characterized in that the cam (4 ) of the vertically movable part (3) comprises first, second and third ramps (14, 15, 16) inclined relative to the direction of sliding of the movable body (7) and able to successively bear against the roller (12) of the movable body (7) during the vertical descent of the movable part (3) for pe transmitting the sliding body (7) to the sheet metal part (P) from a retracted position of this body, respectively following a first launching stroke (a) during which the moving body (7) has a speed relatively small displacement relative to the speed of descent of the movable portion (3), a second approach stroke (b) during which the movable body (7) has a movement speed substantially equal to the speed of descent of the moving part (3) and a third working stroke (c) during which the movable body (7) has a relatively slow moving speed with respect to that of the moving part (3). 2. press tool according to claim 1, characterized in that the angle of inclination of the second ramp (14) is 45 °. 3. Press tooling according to claim 1 or 2, characterized in that the inclination angles of the first and second ramps (14,16) are 70 ° relative to the sliding direction of the movable body (7). 4. press tool according to one of claims 1 to 3, characterized in that the launching stroke (a) of the movable body (7) represents about 10% of its total stroke from its retracted position to its working position at which the working tool (11) carries out its technical operation, the approach stroke (b) of the movable body (7) represents approximately 80% of its total stroke and the working stroke (c) of the moving body (7) ) represents 10% of its total stroke. 5. press tool according to one of claims 1 to 4, characterized in that the movable body (7) of the slider (6) is returned to its retracted position by a return spring (13), such as a jack gas. 6. press tool according to one of claims 1 to 5, characterized in that the three ramps (14,15,16) are constituted by sections connected to each other. 7. press tool according to one of claims 1 to 5, characterized in that the three ramps (14,15,16) have a curved profile. 8. press tool according to one of claims 1 to 7, characterized in that the vertically movable upper part (3) is a press slide.