EP1459822B1 - Tool for deburring forgings - Google Patents

Abstract

The tool has an upper trimming punch (6) integrated with a vertically movable slide. A lower punch (13) traverses a lower trimming plate (11) at base of the upper punch (6). The lower punch (6) co-operates with the lower trimming plate (11) to cut burr of a crankshaft when the crankshaft arrives in contact with the trimming plate (11) and to rectify the crankshaft retained between two punches.

Description

The present invention relates to a tool for deburring forged mechanical parts, such for example crankshafts for motor vehicles.

Most four or six cylinder engine crankshafts are forged and have the particularity of having counterweight faces and spokes that remain forging, which saves time in machining.

In this type of engine, the clearances between the rotating crankshaft and the housings are small and the areas that are not machined must therefore have good dimensional and geometric accuracy. In forge, the main causes that influence these precisions are the offset and the arrow of the crankshaft, the arrow causing great difficulties to properly balance the crankshaft.

JP 63 286234-A discloses a tool for deburring forged mechanical parts according to the preamble of claim 1 and wherein the barb is cut by means of a press which exerts a stress on the workpiece at the time of cutting, thus avoiding the formation of defects in the room. The constraint is exerted by a cylinder which not only increases the costs of the press, but imposes the realization of a specific press.

The invention proposes a tool which, while allowing the deburring of crankshafts, virtually eliminates crankshaft deflections and is inexpensive since it can be mounted on a traditional press.

For this purpose, the invention proposes a tool according to claim 1.

In addition, the vertically movable plate is integral with two respective central branches of two parallel parts spaced apart and in the form of a stirrup between the lateral branches of which is disposed the fixed deburring plate and in that the adjustable stops are mounted respectively on the free end faces of the lateral branches of the stirrup parts.

Advantageously, shims are interposed between the abutments and the end faces of the lateral branches of the stirrup pieces so as to adjust to a predetermined value the spacing between the slide and the vertically movable plate corresponding to the space required between the punches. to grip the forging as soon as the feet contact the stops.

According to one embodiment, each stop comprises a circular head on which comes into contact the corresponding foot and a removable cylindrical pin in a piercing of the side branch of the stirrup piece.

In addition, each elastic member is interposed between the corresponding lateral branch of the stirrup piece and the support plate and comprises a stack of elastic washers mounted concentrically on a cylindrical axis fixed in the support plate projecting perpendicularly thereto. to engage sliding in the end of the bore opposite to that receiving the stopper pin.

During the descent of the punches after cutting the burr, the latter is secured to the upper punch by surrounding and during the controlled lift of the slider, the resilient members exert a return force on the lower punch now the forged part clamped between both punches until the lower punch returns to its high resting position protruding from the deburring plate.

The slider further comprises a horizontal plate traversed by the upper punch, with controlled displacement relative to the slider and movable downwardly relative to the upper punch when the slider returns to its inactive high position to eject the burr of the upper punch and drop it. in a recycling bin.

Advantageously, the slide of the press is mounted vertically movable on two guide columns integral with the support plate.

A robot is provided to deposit by its gripper arms the forged piece to smash on the lower punch and subsequently remove the deburred forging of this punch.

According to another embodiment, the stops may be of electrical or hydraulic type and are remotely controlled, for example from the control panel of the press, which may be of the hydraulic type.

• la figure 1 est une vue en perspective d'un outillage d'ébarbage de pièces mécaniques forgées de l'invention et occupant sa position de réception d'une pièce forgée à bavure ;
• la figure 2 est une vue en perspective d'un outillage de la figure 1 sur lequel est disposée une pièce forgée à bavure ;
• la figure 3 est une vue en coupe dans le plan vertical contenant la ligne III-III de la figure 2 ;
• la figure 4 est une vue en perspective de l'outillage à une position à laquelle la pièce forgée à bavure est enserrée entre deux poinçons supérieur et inférieur avant découpe de la bavure ;
• la figure 5 est une vue en coupe dans le plan vertical contenant la ligne V-V de la figure 4 ;
• la figure 6 est une vue en perspective représentant la position des deux poinçons supérieur et inférieur en figure 4 sans la pièce forgée à bavure ;
• la figure 7 est une vue en perspective de l'outillage à sa position de découpage de la bavure de la pièce forgée ;
• la figure 8 est une vue en coupe dans le plan vertical contenant la ligne VIII-VIII de la figure 7 ;
• la figure 9 est une vue en perspective de l'outillage à sa position dégagée d'accès à la pièce forgée ébarbée ;
• la figure 10 est une vue en coupe dans le plan contenant la ligne X-X de la figure 9 ; et
• la figure 11 est une vue en perspective de l'outillage montrant un robot saisissant la pièce forgée ébarbée et récupérant la bavure découpée auparavant.

The invention will be better understood, and other objects, characteristics, details and advantages thereof will appear more clearly in the explanatory description which will follow with reference to the accompanying drawings given solely by way of example illustrating an embodiment. of the invention and in which:

• Figure 1 is a perspective view of a deburring tool of forged mechanical parts of the invention and occupying its position of receiving a forged piece to burr;
• Figure 2 is a perspective view of a tool of Figure 1 on which is disposed a forged piece to burr;
• Figure 3 is a sectional view in the vertical plane containing line III-III of Figure 2;
• FIG. 4 is a perspective view of the tooling at a position at which the burr forging is clamped between two upper and lower punches before cutting the burr;
• Figure 5 is a sectional view in the vertical plane containing the line VV of Figure 4;
• Figure 6 is a perspective view showing the position of the two upper and lower punches in Figure 4 without the burr forging;
• Figure 7 is a perspective view of the tool at its cutting position of the burr of the forged part;
• Figure 8 is a sectional view in the vertical plane containing the line VIII-VIII of Figure 7;
• Figure 9 is a perspective view of the tool at its unobstructed access position to the deburred forging;
• Figure 10 is a sectional view in the plane containing line XX of Figure 9; and
• Figure 11 is a perspective view of the tooling showing a robot grasping the deburred forging and recovering the previously cut out burr.

The tooling of the invention will be described in the application to the deburring of a crankshaft forged for internal combustion engine for example four or six cylinders, but it is understood that it can be applied to any other type of forged mechanical part.

As is known per se, the crankshaft 1 is first forged preferably in two strokes under an automatic press, for example 5000 tons, and is then preferably transferred by the clamps 2a of a robot arm 2 , only shown in Figure 11, the tool of the invention to be deburred and straightened simultaneously as will be described below in accordance with the invention.

The press to which are mounted the various tools of the invention may be a mechanical or hydraulic press of a power dependent on the forged part that will deburr and straighten. For a crankshaft, the power of such a press can range from 300 to 1000 tons.

The tool of the invention as shown in the figures comprises an upper part fixed on the slider 3 vertically movable relative to a lower horizontal support plate 4 by means of two vertical telescopic columns 5 whose lower ends are secured to the plate 4, the slide 3 extending parallel to the top of the plate 4.

An upper trimming punch 6 is fixed by any suitable means under the slider 3 so as to follow the downward and upward movements of this slider relative to the support plate 4.

A rectangular plate 7 for extracting or ejecting the cut out flaw 1a of the crankshaft 1 as will be seen later is fixed under the slider 3 parallel thereto and can be controlled so as to move vertically from its position rest near the slider 3 at its extraction position of the burr 1a integral with the upper punch 6 away from this slider. The plate 7 has four guide pins 8 arranged approximately at the four corners of the plate 7 and can respectively slide in four conjugate holes 9 of the slide 3. The descent and rise movements of the plate 7 relative to the slide 3 can be controlled by a jack (not shown).

The upper punch 6 passes through a conjugate opening 7a of the extraction plate 7 so that the latter can move vertically relative to the punch 6.

The slider 3 further comprises four vertical feet 10 secured to the slider projecting therebelow and two by two disposed on either side of the extraction plate 7 and the upper punch 6.

The tooling further comprises a fixed lower deburring plate 11 integral with a generally parallelepipedal support block 12 fixed on the support plate 4 and a lower punch 13 passing through the deburring plate 11 directly above the upper punch. 6. The deburring plate 11 comprises a deburring relief 11a cooperating with the punch 13 to cut the burr 1a of the crankshaft 1.

The lower punch 13 is secured to a plate 14 extending transversely to the support plate 4 in a direction parallel to the telescopic guide columns 5 and movable vertically relative to the trimming plate 11 beneath the latter so as to occupy a high position. to which the upper punch 13 protrudes from the deburring plate 11 and its relief 11a at a low position at which the burr 1a of the crankshaft 1 is cut from the latter by the relief 11a of the deburring plate 11.

The plate 14 is integral with two identical stirrup pieces 15 spaced parallel to each other while extending perpendicularly to the plane vertical direction passing through the two guiding columns 5. More specifically, the plate 14 for supporting the lower punch 13 is fixed on the two central branches 15a of the stirrup parts 15 between the two lateral branches 15b of these two parts. The plate 14 extends perpendicular to the central branches 15a of the stirrup parts 15 and the deburring plate 11 extends between the lateral branches 15b of the stirrup parts 15.

Elastic members 16 are interposed between the stirrup parts 15 and the support plate 4 so as to bring the stirrup parts 15 in the raised position relative to the support plate 4 and thus to the block 12. The downward movement of the stirrup parts 15 to the plate 4 is thus done against the restoring force of the elastic members 16. Each of these is preferably constituted by a stack of spring washers 17 mounted concentrically to a vertical cylindrical axis 18 secured to the plate 4 and whose upper end protruding from this plate is slidably mounted in a bore 19 formed through a corresponding one of the lateral branches 15b of a stirrup member 15. Thus, there are four elastic members 16 associated respectively with the four side branches extending upwards 15b of the stirrup parts 15. In the upper position of the stirrup parts 15 and thus of the punch lower 13, about a lower half of the stacked washers 17 of each elastic member 16 is housed in a corresponding vertical bore 20 of the support plate 4 and a few washers 17 of the upper portion of the elastic member 16 are housed in a corresponding counterbore 21 performed under the vertical side branch 15b of the stirrup part 15 coaxially with the bore 1a. The upper and lower washers 17 of each resilient member 16 are respectively supported on two rigid washers 22 resting against the bottom of the countersink 21 and the corresponding bore 20, the washer 22 being slide along the associated axis 18 during vertical movements of the stirrup part 15 relative to the support plate 4.

On each upper horizontal end face of a lateral branch 15b of a stirrup piece 15 is mounted an adjustable stop 23 comprising a circular head 24 on which can come into contact a corresponding foot 10 of the slider 3 and a cylindrical pin 25 removably fixed in the end of the bore 19 opposite that into which penetrates the upper end of the guide pin 18.

Shims 26 may be interposed between the head 24 of each abutment 23 and the upper face of the corresponding lateral branch 15b of a stirrup piece 15. The wedges 26 make it possible to adjust the spacing between the slider 3 and the stirrup parts 15, and therefore the vertically movable plate 14, as soon as the feet 10 come into contact with the heads 24 of the abutments 23 during the lowering of the slide 3. This spacing value determines the space required between the upper punches 6 and lower 13 to enclose the forging 1 between them.

As best shown in FIG. 6, the upper and lower punches 6 each define a recess 6a, 13a matching the contours of the crankshaft 1 along the latter without interfering with the burr 1a of the crankshaft 1 projecting from both sides. other of this crankshaft. Thus, each punch 6 and 13 may consist of a plurality of vertical walls 6b, 13b extending in a longitudinal direction parallel to the guide columns 5 facing each other so as to grip the crankshaft to distinct locations located along it.

The arrows F1 and F2 in FIG. 1 symbolize the passage of a cooling liquid through a cooling circuit formed in the plate deburring 11, circuit not shown in the figures so as not to overload.

The operation of the press is already apparent from the description which has been made above and will now be explained.

At the waiting position of the press shown in FIG. 1, in which the slider 3 occupies its raised position above the lower punch 13, the robot 2 grasps the forged crankshaft 1 with its burr with its gripping tongs 2a. 1a to place this assembly on the lower punch 13 as shown in Figures 2 and 3 which show that the lower part of the crankshaft 1 is housed in the footprints 13a conjugate of the lower punch 13 with the burr 1a overflowing all around the crankshaft 1 above of the punch 13 in the longitudinal median plane of the crankshaft 1. The punch 13 occupies its high position protruding above the relief 11a of the deburring plate 11 under the action of the upward restoring force exerted by the elastic members 16 .

Then, the slider 3 is controlled so as to descend in a guided manner by the columns 5 towards the support plate 4 until the upper punch 6 comes to cap and grip the crankshaft 1 between this punch and the lower punch 13 and, simultaneously, the feet 10 come into contact respectively on the abutments 23. The shims 26 located under the heads 24 of the abutments 23 have been previously adjusted according to the thickness of the forged crankshaft 1, the adjustment of these wedges to not leave that the space required for the crankshaft 1 between the punches 6, 13. Such an adjustment is made in the present case manually, but can be automated by adjustable stops, electrical or hydraulic type, remotely controlled to determine their position adjusting the space just needed for the crankshaft 1 between the punches 6, 13. Figures 4 and 5 illustrate the imprisonment of the crankshaft 1 between the punches 6 and 13 when the feet 10 have just contacted the stops 23, the lower punch 13 still occupies its high position above the deburring plate 11.

Continuing to descend, the slider 3 also drives down the crankshaft and its burr against the restoring force exerted by the resilient members 16 and at the moment when the burr 1 of the forging 1 comes into contact with the cut of the relief 11a of the deburring plate 11, the pressure exerted by the elastic members 16 on the crankshaft via the punches 6, 13 is about 120 tons, which allows to straighten the crankshaft which would have been folded during the stamping operation before being brought to the press of the invention.

The slider 3 continues to descend so that the burr 1a, in contact with the cutout of the deburring plate 11, can be cut and thus disengaged from the crankshaft 1 without the latter being able to deform, the pressure exerted during the cutting is about 350 tons. Figures 7 and 8 show the state of the slider 3 at its lowest position at which the burr was cut by the trimming plate 11 and disengaged upwards from the crankshaft to be arranged around the upper punch 6 which holds this burr.

The slider 3 is then controlled so as to rise and the elastic members 16 exert the upward restoring force for holding the crankshaft 1 sandwiched between the two upper and lower punches 6 until the lower punch 13 reaches its high position. above the deburring plate 11 as shown in Figures 9 and 10 and, continuing to rise, the slider 3 carries with it the burr solidarisée the lower end of the deburring punch 6 which remains on it ci when the slider 3 reaches the end of the race to its high position. We will note that during the raising of the slider 3 until the lower punch 13 reaches its high position under the action of the elastic members 16, the punch 6 and the punch 13 pass through the deburring plate 11 without the crankshaft 1 can not deform.

FIG. 11 shows that the robot 2 situated at the rear of the press has grasped with its tongs 2a the deburred crankshaft 1 to extract it from the lower punch 13 and the extraction plate 7 has been commanded downwards to remove the burr 1a of the upper punch 6 and fall into a recovery receptacle 2b of the robot 2 which then withdraws from the press to evacuate the crankshaft 1 and the burr 1a.

The operating cycle described above is repeated to deburr and simultaneously straighten a new forged crankshaft 1 to burr 1a.

The press according to the invention thus simultaneously makes it possible to deburr a forged crankshaft and to straighten it in the event that it has been folded during the preceding stamping operation so as to practically cancel the deflection defects of this crankshaft, whereas previously such crankshafts could have arrows up to 1.8mm causing great difficulties in balancing thereof, intolerable imbalance in the case of a crankshaft four or six cylinder internal combustion engine.

Various modifications may be made to the tool described above without departing from the scope of the invention. Thus, the usual control panel of the press can be used to remotely control the movement of the slider 3, the displacement cylinder of the extraction plate 7 of the burr 1a and the electrical or hydraulic stops for adjusting the space crankshaft between the two upper punches 6 and lower 13 of the tool.

The various tools of the invention can be mounted on a traditional mechanical or hydraulic press of a power depending of course on the size of the forged part to deburr and straighten, power ranging from 300 to 1000 tons for deburring and straightening a crankshaft as already mentioned before.

Claims (11)

1. A tool for deburring forged mechanical parts (1) such as crankshafts for motor vehicles, comprising a press; an upper deburring punch (6) integral with a vertically guided mobile slide (3) of the press; a lower fixed deburring plate (11) integral with a supporting platform (4); a lower punch (13) passing through the deburring plate (11) at the base of the upper punch (6), integral with a plate (14) vertically mobile relatively to the deburring plate (11) under the latter and which may occupy a high position protruding from the deburring plate (11) at which a forged part (1) is deposited on the lower punch (13) before the controlled downward movement of the slide (3) and is then hemmed in between the lower (6) and upper (13) punches during the downward movement of the slide (3) which causes the concomitant downward movement relatively to the deburring plate (11) of the punches (6, 13) hemming in the forged part (1) and of the vertically mobile plate (14) against the restoring force of elastic members (16) so as to cut the burr (1a) off the forged part (1) when it arrives in contact with the deburring plate (11), the elastic members (16) exerting on the punches (6, 13) increasing pressure as the punches (6, 13) gradually pass downward through the deburring plate (11) and with which if necessary, the forged part (1) may be straightened, and characterized in that the slide (3) comprises, integral with the latter, at least two identical vertical legs (10) located on either side of the upper punch (6) and coming into contact during the downward movement of the slide (3) on two adjustable stops (23) cinematically connected to the vertically mobile plate (14), respectively, and located on either side of the deburring plate (11) to move the plate (14) downwards against the restoring force of the elastic members (16).
2. The tool according to claim 1, characterized in that the vertically mobile plate (14) is integral with two respective central branches (15a) of two stirrup-shaped parts (15) spaced apart in parallel and between the side branches (15b) of which the fixed deburring plate (11) is positioned, and in that the adjustable stops (23) are respectively mounted on the faces of free ends of the side branches (15b) of the stirrup-shaped parts (15).
3. The tool according to claim 2, characterized in that shims (26) are interposed between the stops (23) and the faces of ends of the side branches (15b) of the stirrup-shaped parts (15) so that the gap between the slide (3) and the vertically mobile plate (14) may be adjusted to a determined value, corresponding to the required space between the punches (6, 13) for hemming in the forged part (1) as soon as the legs (10) come into contact with the stops (23).
4. The tool according to claim 3, characterized in that each stop (23) comprises a circular head (24) onto which the corresponding leg (10) will come into contact, and a cylindrical slug (25) removably fixed in a bore (19) of the side branch (15b) of the stirrup-shaped part (15).
5. The tool according to claim 4, characterized in that each elastic member (16) is interposed between the corresponding side branch (15b) of the stirrup-shaped part (15) and the supporting platform (4) and comprises a stack of elastic washers (17) concentrically mounted on a cylindrical axis (18) fixed in the supporting platform (4) by protruding perpendicularly to the latter in order to slidably engage into the end of the bore (19) opposite to the one receiving the slug (25) of the stop (23).
6. The tool according to any of the preceding claims, characterized in that, during the downward movement of the punches (6, 13), after cutting the burr (1a), the latter becomes integral with the upper punch (6) by surrounding it and during the controlled upward movement of the slide (3), the elastic members (16) exert a restoring force on the lower punch (13) which maintains the forged part (1) hemmed in between both punches (6, 13) until the lower punch (13) is again found in its high resting position protruding from the deburring plate (11).
7. The tool according to claim 6, characterized in that the slide (3) further comprises a horizontal plate (7) through which the upper punch (6) passes, with controlled movement relatively to the slide (3) and which may be moved downwards relatively to the upper punch (6) when the slide (3) occupies its high inactive position in order to eject the burr (1a) from the upper punch (6) and to have it fall into a scrap bin (2b).
8. The tool according to any of the preceding claims, characterized in that the slide (3) is mounted vertically mobile on two guiding columns (5) integral with the supporting platform (4).
9. The tool according to any of the preceding claims, characterized in that a robot (2) is provided for depositing with its gripping arms (2a), the forged part (1) with a burr (1a) on the lower punch (13) and subsequently withdrawing the deburred forged part (1) from this punch.
10. The tool according to any of the preceding claims, characterized in that the stops (23) are of the electric or hydraulic type and are remote-controlled, for example from the control console of the press.
11. The tool according to any of the preceding claims, characterized in that the press is of the hydraulic type.

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