EP0206187B1 - Punch-sensing device in a cross-transfer press - Google Patents

Abstract

A punch probing device including at least one punch and a cooperating punch feeler. The feeler is operable to detect both foreign matter on the punch and damage of said punch. The feeler is moved perpendicularly into and out of operative engagement with the punch by means of a linkage parallelogram. Controls for the punch and linkage are provided.

Description

The invention relates to a cross transport press with a device according to the preamble of claim 1.

Such a device is used in a cross transport press to continuously monitor its operation and is intended, for example, to determine whether a part is stuck on a stamping tool after a machining operation has been carried out. If this is the case, the device switches off the press immediately so that a so-called "double loader ^w " does not occur when feeding a part to be subsequently machined. Furthermore, such a device can also be used to monitor the state of the stamping tool after each working stroke, With such control measures, the press and the tools are saved from further consequential damage after a single malfunction, for example caused by a broken stamp, and the production of unnecessary rejects is avoided Finally, the device can also be used for periodic cooling of the stamping tools.

A corresponding safety device is known from DE-C-2 907 464. In this device, a scanning rocker rotatably mounted about a horizontal axis is driven in the work cycle of the press via a lever joint control such that it is in normal operation of the press between a scanning position in which the press slide is in its rear press slide position and a waiting position in one with respect to the Working area of the press above area is pivoted. The scanning rocker carries stamp sensors assigned to the individual stamps, these are moved along with the corresponding pivoting and are moved past the front face of the respective stamp in the working position of the rocker. If there is still a part that has already been machined on the stamp, the corresponding stamp sensor hits it, causing a malfunction to be identified and the press to be put out of operation immediately. In this known device, it is also provided that the stamp end faces are cooled by means of cooling showers provided on the stamp sensors. The coolant used for this is led through the tubular rocker arms to the individual cooling showers. Furthermore, the scanning rocker can be swiveled up together with the plunger sensors by means of a piston-cylinder unit into a position above the pivoted working area during normal operation of the rocker, so that, for. B. a tool changeover can take place without hindrance by the safety device.

This known safety device can be used in forming machines with a C-body. If a metal-forming machine has a closed frame, there is relatively little space, especially in the scanning or sensing area, which does not allow the known safety device, which requires a relatively large swiveling area, to be accommodated. Also, the scanning rocker with the stamp sensors must always be shifted in a circular path around the rocker pivot axis, as a result of which the stamp sensors of the known device are fixed to a scanning curve, the adaptation of which to the stamp geometry and movement causes problems. Because of the limited space available for the scanning or sensing area, the scanning curve on which the stamp sensors are moved should run as flat and as close as possible to the end faces of the stamp so that there are no collisions between the stamp sensors and the stamps and / or the cross transport tongs can come. This requirement cannot be met satisfactorily even by modifying the known safety device, since conceptual limits are set by its operating principle.

Furthermore, it is a disadvantage of the known safety device that, if a machined part remains on a stamp, the entire weight of the safety device hits this part, which can cause damage to the part, the tool and also to the stamp sensors.

The object of the invention is to provide a transverse transport press with a device of the type defined in the introduction, which, while avoiding the disadvantages of the known, has a scanning curve shape optimally adapted to the stamp movement and function with regard to the movement of the stamp sensor and, in the event of a malfunction, with minimal stress on tools and workpieces take effect immediately, whereby this device should be of simple construction and reliable in use in view of the limited space in the scanning or sensing area, and in which all functions can also be operated and controlled from a control desk located away from the press should.

The solution features of the object according to the invention result from the patent claims and in particular from the characterizing part of claim 1.

Accordingly, the cross transport press according to the invention has a device in which the stamp sensor movement is controlled by means of a parallel lever gear known per se (DE-AS-2 023 871). In the embodiment of this parallel lever mechanism according to the invention, the link lengths are approximately the same length in pairs, which is why they cause approximately parallel guidance of the central link to a connecting line laid by the pivot bearings of the two links in the bearing block arrangement over a certain pivoting range of the upper and lower links. With a correspondingly parallel arrangement of the sensor cam surface and the sensor surface of the stamp sensors, there is an approximately rectilinear displacement of the surface sections perpendicular to the respective stamp displacement axes. The drive linkage of the stamp sensor device designed in the manner described in the description thus requires an approximately rectilinear displacement of the stamp sensors, which are thus moved on a scanning curve which is so flat that the stamp sensors can be accommodated without hindrance even in the narrowest working areas of a forming machine. Also, as a result of the almost straight-line stamp sensor movement, scanning can be carried out extremely close to the respective stamp end faces, which enables reliable monitoring of the stamp contour. In addition, can be a collision with other parts of the machine, for. B. reliably avoid the cross transport tongs. Furthermore, the effectiveness of the cooling effect that can be achieved via the coolant showers can be decisively increased by the small distance that can be maintained when scanning to the stamp end faces.

Since it is provided according to the invention that each stamp sensor is provided with an actuating element for a switch which puts the machine out of operation in the event of a fault, an exact indication of the location of the fault can be achieved via the actuating elements to be set separately on each stamp, for example via an indicator lamp for each stamp sensor on a central control panel.

In this context, it is particularly advantageous that in the device according to the invention the actuating element is provided in the form of a transmission tube which is relatively displaceable on the plunger sensor and is spring-loaded in its pivoting direction into the scanning or sensing area and which cooperates with the switch for stopping the machine. As soon as one of the stamp sensors strikes a part remaining on the stamp during the vertical swiveling-in movement of the stamp sensor into the scanning or sensing area, the resilient preload yields and the stamp sensor cam is supported on the part in the manner of a telescope as a result of the further movement of the stamp sensor arrangement Stamp sensor housing inserted. After a certain displacement, the switch mentioned is activated and the machine is stopped immediately. The resiliently preloaded design of the transmission tube means that when the plunger sensor hits a workpiece, only a small impact load is exerted on it and the entire drive linkage, so that the tool, workpiece and also the plunger sensor arrangement itself are subjected to minimal stress and can be practically undamaged .

If, according to a preferred embodiment, a proximity initiator is additionally provided in the stamp sensor, the stamp contour can be checked after each press stroke, a change in the tool status can be indicated immediately and, if necessary, the machine can be stopped.

The stamp sensor swivel drive provided in the device according to the invention is used for remote-controlled swiveling up of the entire stamp sensor arrangement and thus for releasing the working area of the press for a necessary retrofitting or repair. The bracket of the swivel drive is located approximately in the middle of the press above the press slide, and from there the drive engages the upper link of the drive linkage. Advantageously, the swiveling drive is provided with drive means which can be operated remotely, so that swiveling up of the stamp sensor arrangement and subsequent lowering can also be included in the largely automated process of the press operation. The arrangement of the swivel drive in the middle of the machine offers the advantage that no adverse torsion can act on the drive linkage.

• Fig. 1 eine perspektivische Schemaansicht einer an einen vorderen Abschnitt einer Quertransportpresse angebrachten Stempelfühleranordnung in der oberen Betriebsstellung nach den Merkmalen der Erfindung,
• Fig. 2 zwei schematische Seitenansichten der Stempelfühleranordnung gemäss Fig. 1 in der oberen (Fig. 2a) und unteren (Fig. 2b) Betriebsstellung,
• Fig. 3a zeigteine vergrösserte Längsschnittdarstellung eines Stempelfühlers mit einem Teil einer Fühlerhalterung der Stempelfühleranordnung gemäss Fig. 1, und
• Fig. 3b einen schematischen Querschnitt durch einen Stempelfühler bei einer Schnittführung längs der Linie 111 - 111 in Fig. 2,
• Fig. 4a und 4b eine schematische Seitenansicht der Stempelfühleranordnung ähnlich der Darstellung in Fig. 2, mit einem an einem Antriebsgestänge der Stempelfühleranordnung angreifenden Hochschwenkantrieb zur Verlagerung des Antriebsgestänges in die in Fig. 4b gezeigte Stellung,
• Fig. 5a zeigt zwei schematische Ansichten eines Ausschnitts des Hochschwenkantriebs gemäß Fig. 4a und 4b zur Verdeutlichung der Funktion einer Riegelanordnung und
• Fig. 5b zwei schematische Ansichten des zweiteiligen Unterlenkers des Antriebsgestänges gemäss Fig. 1 zur Veranschaulichung der Funktionsweise einer Lenkerverriegelung.

Further advantages of the device according to the invention are explained in more detail below in connection with the description of a specific exemplary embodiment with reference to drawings. Show it:

• 1 is a perspective schematic view of a stamp sensor arrangement attached to a front section of a cross transport press in the upper operating position according to the features of the invention,
• 2 shows two schematic side views of the stamp sensor arrangement according to FIG. 1 in the upper (FIG. 2a) and lower (FIG. 2b) operating position,
• Fig. 3a shows an enlarged longitudinal sectional view of a stamp sensor with part of a sensor holder of the stamp sensor arrangement according to Fig. 1, and
• 3b is a schematic cross section through a stamp sensor with a cut along the line 111-111 in Fig. 2,
• 4a and 4b is a schematic side view of the stamp sensor arrangement similar to that 2, with a swiveling drive acting on a drive linkage of the plunger sensor arrangement for displacing the drive linkage into the position shown in FIG. 4b,
• 5a shows two schematic views of a section of the swivel drive according to FIGS. 4a and 4b to clarify the function of a latch arrangement and
• 5b shows two schematic views of the two-part lower link of the drive linkage according to FIG. 1 to illustrate the functioning of a handlebar lock.

1, a press slide 2 is slidably mounted in a press frame 3 and is periodically moved in the direction of the double arrow shown on the press slide by means of a drive, not shown. At the front, four punches 1 are attached to the press slide 2, which, as indicated in FIG. 2, are provided with forming dies 36 which cooperate with the punches 1 in a known manner.

A punch drive is provided over the front end of the press slide 2, which is supported on a bearing block arrangement 15 attached to the press frame 3 and is inevitably actuated with the press slide movement via a lever control. This lever control is formed from a mirror joint provided on both sides of the press slide, which is formed in each case from a coupling 7 and a pivot axis 6a engaging in a press slide attachment 6. The couplers 7 are each connected to the handlebar section ends via a pivot bearing 37.

The stamp sensor arrangement 4 has a drive linkage which is formed from links coupled to a parallel lever transmission. As can be seen from FIG. 1, two two-part lower links 8, 11 are articulated in lower pivot bearings 14 on bearing blocks 15a, 15b which are aligned with one another and are arranged opposite one another on the press frame 3 with respect to the press slide 2. As can be seen in particular from FIG. 2, when the press slide 2 is shifted in the direction of the arrows, the lower links 8, 11 are synchronously moved between the ones shown in FIG. 2 by the lever control 6, 6a, 7 about the lower pivot bearings 14 End swivel positions adjusted. Between the ends of the lower links 8, 11, which face the end faces of the stamp, a sensor carrier 16 is pivotally mounted, which according to FIG. 1 carries a series of four adjacent stamp sensors 4, each of which is firmly connected to the sensor carrier 16 via a sensor holder 5 and Have sensor cams 19, the stamp sensors being oriented so as to protrude approximately perpendicular to the stamp displacement direction in the scanning or sensing area 9 of the press indicated in FIG. 2 between the stamps 1 and the forming dies 36.

As can again be seen in FIG. 1, there is a central link 12 at half the transverse distance between the ends of the lower links 11, which is attached to the sensor carrier 16 in a rotationally fixed manner and at its end opposite this connection point with an upper link 13 which is approximately parallel to the lower link 11 runs, is articulated. The upper link 13 is rotatably connected about half the distance between the bearing blocks 15a, b to a pivot shaft 22 which is rotatably supported in the upper pivot bearings 17 of the bearing block arrangement 15. As shown in FIG. 2, the drive linkage, consisting of the links 11, 12 and 13, is driven with a corresponding displacement of the press slide such that the links 11 and 13 are pivoted about their pivot bearings 14, 17 on the bearing block arrangement, whereas the center link 12, which Sensor carrier 16 and thus the stamp sensor 4 experience a parallel and approximately rectilinear displacement which is perpendicular to the stamp displacement direction and which is indicated by the vertical arrows in FIG. 2. The upper illustration in FIG. 2 shows the punch 1 in a front press stroke end position, while the lower illustration schematically indicates the rear press stroke end position. The stamp sensor 4 thus enters the scanning or sensing area 9 with the stamp 1 in the rear press stroke end position in order to be able to pass as close as possible to the stamp end face (cf. FIG. 3b). The functionally essential course of the parallel guidance of the stamp sensor 4, which is approximately vertical to the stamp movement, is thus approximately limited to the section from the possible displacement of the drive linkage 13, 13 shown in FIG. 2, which is why the movement sequence shown there roughly corresponds to that carried out during normal operation of the press Reproduces stamp sensor displacement.

It can be seen from FIG. 3a that the stamp sensor housing 39, which is connected to the sensor carrier 16 via a laterally projecting connecting tube 38, is hollow in its interior and has a transmission tube 24 enclosed by a spring 40 in its interior. At the upper and lower ends of the sensor housing 39 according to FIG. 3a, the transmission tube 24 is slidably sealed and has a lateral wall opening 41 which opens its interior towards the connecting tube 38. 3a is screwed to the lower end of the transmission tube 24 according to FIG. 3a, which, as also shown in FIG. 3b, has a hollow housing section which is rectangular in cross section and tapered in a longitudinal section according to FIG. 3a. This 3b has a multi-hole coolant outlet shower 21 through which coolant, through channels 23, through the connecting pipe 38, the transmission pipe 24 and the housing section, is supplied in the direction of the arrows shown in FIG. 3a and is sprayed onto the end face of the stamp sensor. 3b shows sensor cams 19 mounted on the side of the stamp sensor, which are guided around the front part of the stamp on both sides thereof. 3b, there is an approach initiator 25, which monitors the surface and stamp contour properties and serves as an actuating element for stopping the machine if deviations from the stamp normal state are detected. The close encircling of the stamp front part visible in FIG. 3b allows reliable scanning of even the smallest parts remaining on the stamp, as well as a correspondingly reliable sensing of the stamp contour for a perfect surface condition and also a narrow cooling space which allows a high cooling effect to be achieved. Such a close approach of the stamp sensor 4 to the end face of the stamp can be achieved due to the described parallel guidance of the stamp sensor drive during normal operation of the press, since the scanning and sensing movement, as said, can be carried out almost linearly vertically to the stamp movement.

At the upper end of the transmission tube 24 according to FIG. 3a there is an actuating element 20 which actuates a switch 10 when the transmission tube is moved upwards, which serves to switch off the machine. If there is still a workpiece or part of the workpiece on the stamp visible in FIG. 3b during the downward movement of the stamp sensor 4, the stamp sensor strikes this part with its cams 19 and as a result of the further downward movement forced by the drive linkage 11, 12, 13 of the plunger sensor, the transmission tube 24 moves against the preload by the spring 40 relative to the sensor housing 39, and after a path that can be preset on the actuating element 20, the switch 10 is actuated, which switches the machine to an immediate stop, i. H. Switching off and braking ensures. The biasing force of the spring 40 is chosen so that with reliable preloading of the stamp sensor 4, the lowest possible load is exerted on the stamp 1 provided with a workpiece, as a result of which both the stamp and the entire stamp sensor drive are stressed as little as possible on impact. The interior of the transmission tube 24 (FIG. 3a) is connected to the sensor carrier 16, which is also tubular and which is connected to a central coolant supply (not shown).

In order to make the stamp work area easily accessible, for example for tool retrofitting, the stamp sensor arrangement must be moved out of this work area. For this purpose, the device parts shown schematically in FIGS. 4 and 5 are provided. 4a shows a plunger sensor swivel drive 27, which is designed as a chain transmission and consists of a driver 29 acting on the upper link 13, a sprocket 30 seated on the swivel shaft 22, a hydraulic drive 31 connected to a second sprocket 32, and a roller chain 33 coupling both sprockets is formed. Due to the forced coupling between the press slide 2 and the lower links 11, the lever control 6, 6a, 7, it is necessary for the pivoting to temporarily cancel the drive effect. For this purpose, the lower links 11 are divided into two link sections 8, 11 (FIG. 5b) which can be pivoted relative to one another on a pivot axis in the lower pivot bearing 14. In normal operation of the press, these two link sections 8 and 11 are locked against relative pivoting by a lock. This lock 26 comprises a remote-controlled hydraulic piston-cylinder unit 34 attached to the handlebar section 8, which carries at its free piston end a latch 35 which engages in a correspondingly arranged on the handlebar portion 11a latch 42 and, as the lower figure in Fig. 5b shows , the two handlebar sections 8 and 11 locked together. In the figure, a spring 43 acting on the latch pawl 35 in the engagement direction is shown. The piston-cylinder unit 34 is single-acting in this case, but it can also be designed as a double-acting unit, whereby the spring 43 could be omitted. In this context, the ability to operate the piston-cylinder unit 34 remotely is of particular importance. For this purpose, hydraulic lines, not shown, are connected, which can be operated from a central control panel, so that direct manipulation of the stamp sensor arrangement is not required for unlocking and locking the lower links 8/11.

The pivoting of the plunger sensor arrangement from the position according to FIG. 4a to the position according to FIG. 4b takes place when the lower links 8/11 are unlocked by actuating the preferably double-acting hydraulic cylinder 31, the piston of which drives the chain transmission via a pivoting lever, so that the driver 29 moves the Drive linkage 11, 12, 13 and thus also the plunger sensor 4 in the position shown in Fig. 4b pivoted up about the axes of rotation 14 and 17 will.

To secure the swivel position according to FIG. 4b, a locking arrangement 28 shown in FIG. 5a is used, which is provided on the driver 29 and interacts with a locking cam 28b, which is fastened to the upper link 13. The latch arrangement 28 has a ratchet latch 28a which is preloaded by a spring 28c in the direction of the latching cam 28b and which is supported to a limited extent on the driver 29. Before the actual swiveling up of the stamp sensor arrangement begins, after a brief initial rotation of the swiveling drive 27, the latch bolt 28a snaps out of the position shown in the lower illustration according to FIG. 5 and remains held by the spring 28c on the one in the illustration 5a, so that, as shown in the upper illustration according to FIG. 5a above, the upper link 13 is held between the driver 29 and the latch bolt 28a. As soon as the driver 29 bears against the lower edge of the upper link 13 in the course of pivoting upward, it takes it into its upward pivoting position and, when this is reached, the upper link 13, as can be seen from FIG hindered to the rear, so that the stamp sensor arrangement can reliably remain in the upward pivoting position shown in FIG. 4b. After the drive linkage has been pivoted back into the position shown in FIG. 4a, the lower link sections 11 meet the stops 44 on the link sections 8 visible in FIG. 6 and thereby limit the pivoting back of the drive linkage. In this position of the linkage, the chain transmission of the swivel drive is still in operation and rotates the driver a little further when the upper link 13 is already stationary, so that the latch bolt 28a slides over the latching lug 28b and comes to a standstill in the position shown in FIG. 5 below is coming. The upper link 13 is now freely movable for the scanning movement controlled by the press slide 2 and, after the lower links 8/11 have been correspondingly locked, is displaced via the lock 26 in the manner described as part of the drive linkage.

The hydraulic cylinder 31 can also be operated remotely and is connected to the central control panel via control lines (not shown). The control measures made possible by the hydraulic cylinder / piston units 34 and 31 allow the stamp sensor arrangement to be swiveled up and swung back in any position in the press slide, so that the stamp sensor arrangement can always be swiveled up in all possible malfunctions over an operational sequence and the work area can thus be exposed for the necessary measures for troubleshooting.

In the exemplary embodiment described, four stamps are shown lying side by side, one stamp sensor being assigned a stamp sensor of the same type. Of course, this arrangement can be deviated from, so that the stamp sensor arrangement can also be used for transverse transport presses with more or fewer stamps and can also be used with stamp sensors of different designs. For example, the last forming station in the manufacturing process could have a separating spade instead of a stamp sensor, which extends the channels of a correspondingly arranged drop chute in such a way that a finished part is always inserted into a dedicated channel of the drop chute.

Claims (5)

1. Cross-feed press having an apparatus for periodically scanning for the presence of a worypiece of at least one punch (1), for sensing the respective outline of the punch and for cooling at least the end face of the punch, the press having a slidingly mounted press carriage (2) with punches mounted at the front, said carriage being driven back and forth between a front and rear end position of the press stroke, a punch sensor drive fixedly mounted on a press frame (3) and at least one punch sensor (4) aligned with the punch (1) in question, said punch sensor (4) being provided on a sensor mounting (5) and being displaceable, via a lever control (6, 7, and 11) operated by the press carriage between a scanning position which, in normal operation of the press, is located in the rear end position of the press stroke immediately in front of the punch (1) in question and a disengaged position in which it is pivoted upwardly out of the path of travel of the press carriage, the punch sensor (4) which comes to rest with its sensor surface (18) having sensor dogs (19) in a plane which is substantially perpendicular to the displacement path of the punch, said sensor surface (18) having sensor dogs (19) having been introduced into the scanning or sensing area (9) and moved in front of the corresponding end face of the punch, when detecting a state which is other than normal in the said scanning or sensing area (9) stops the press by actuating an actuating element (20) via a switch (10), said actuating element being provided on the sensor dog (19) as well as at the area surrounding said sensor surface (18), characterised in that the movement of the punch sensor is controlled by means of a drive linkage (8, 11, 12, 13) constructed as a parallel lever transmission, which comprises at least one two-part lower control lever (8, 11) which is pivoted, in a lower pivot bearing (14), to a bearing block arrangement (15) provided in a fixed position on the press frame (3) and formed from two bearing blocks (15a, b) secured on both sides of the path of travel of the press carriage on the press frame (3), that the sensor mounting (5) is provided in the transverse gap between the ends of the lower control lever nearest the punch end faces and the lever control (6, 7) is connected to the ends of the lower control lever (8, 11) opposite the lower pivot bearing (14), and further characterised in that the drive linkage has at least one central control lever (12) non-rotationally mounted on a sensor carrier (16) of the sensor mounting (5), said central control lever being connected for rotation with the sensor mounting substantially half way across the transverse spacing between the lower control levers and at least one upper control lever (13) which connects this central control lever (12) to the bearing block arrangement (15), said upper control lever being connected by a pivotal connection to the central control lever and to a pivot shaft (22) which bridges the two bearing blocks (15a, b) and is supported in an upper pivot bearing (17).

2. Apparatus according to claim 1, characterised in that each lower control lever (11) consists of two control lever parts (8, 11) which are pivotable relative to each other about the associated lower pivot bearing (14) on the bearing block (15a, 15b), said control lever parts being prevented from pivoting relative to each other by means of a remotely controlled locking mechanism (26) during normal operation of the press, and in that there are provided, substantially in the centre of the press, above the press carriage (2) on the part connecting the upper control lever (13) to the pivot shaft (22), a drive (27) for upwardly pivoting the punch sensor and a locking arrangement (28) which locks the drive linkage during the upward pivoting and in the uppermost position reached by the pivoting movement.

3. Apparatus according to claim 2, characterised in that the upward pivoting drive (27) for the punch sensor is a chain drive which has a chain wheel (30) coupled to a follower (29) engaging on the upper control lever (13) and another chain wheel (32) which is actuable by a hydraulic piston-cylinder unit (31), more particularly having a double action, fixedly mounted on the press frame (3) and also capable of remote control as well as a roller chain (33) connecting the two chain wheels, and the locking arrangement (28) is formed by a stop (28b) protruding from the part of the upper control lever opposite the point of engagement of the follower on the upper control lever (13), and a locking bolt (28a) which is spring-biased against this stop.

4. Apparatus according to claim 2 or 3, charactecised in that the locking mechanism (26) comprise a locking pawl (35) slidably mounted on a part (8) of the control lever and connected to a remotely controlled hydraulic piston-cylinder unit (34), and a pawl catch (42) mounted on the lower control lever (11).

5. Apparatus according to claim 1 or 2, characterised in that on all the punch sensors (4) coolant is supplied to the coolant exit jets (21) through channels (23) formed through the interior of the hollow sensor mounting (5) and in that the actuating elements for the switch (10) comprise a transfer tube (24) connected to the sensor dogs (19) of each punch sensor (4) spring-biased in the direction of pivoting of the punch sensor into the scanning or sensing area (9), and guided in relatively movable manner in the punch sensor housing (39), and optionally a proximity initiator (25) housed in the sensing area of the punch sensor.

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