EP2011636A2 - Load reversal-free ram connection device - Google Patents

Abstract

The press has a plunger connected with a drive device over a connecting rod (9). The connecting rod is connected with the plunger by an adjusting device (11). The adjusting device includes an adjustable threaded joint, which is attached to a pre-tensioning device e.g. hydraulic piston (15). The threaded joint has a adjusting spindle (19) that is connected with the connecting rod, and an adjustment nut (23) that is connected with the plunger. The pre-tensioning device stretches the nut against the spindle.

Description

The invention relates to a press, in particular a large-size press.

Mechanical presses usually have a plunger, which is moved by a suitable drive device in a predetermined manner going back and forth. The drive device is connected via gear means with the plunger. For example, the drive device is formed by one or more eccentrics, which are connected via corresponding connecting rods with the plunger. Frequently adjusting devices are provided at the junction between the plunger and the connecting rod, with which the plunger position can be adjusted as desired, for example, to adapt to different tools. Such adjusting devices often contain threaded elements that are selectively rotated against each other for adjusting the plunger position.

At such adjustment can occur during the reciprocation of the plunger, a change in sign of the load direction. For example, if it is a bulk press with a plunger movable vertically up and down, the load of the plunger and the upper tool part normally depends on the connecting rod and additionally on a so-called weight compensation device. During workpiece reshaping they transfer the Push rod moving connecting rod a compressive force on the plunger. Before and after, they transmit a traction. This load change can lead to wear on the adjustment, which connects the connecting rod with the plunger. In particular, existing threads are at risk here.

On this basis, it is an object of the invention to provide an improved press.

This object is achieved with the press according to claim 1. This press has a biasing device associated with the biasing device, which avoids load changes on the adjusting device. This eliminates any existing in the range of adjustment game. There is no reversal in the direction of the burden. Rather, it is only a dynamic swelling load, which increases the life of the engaged elements. In the threaded connection of the adjusting device, the thread size for the adjusting nut and the adjusting spindle can be selected correspondingly smaller with the same service life.

The threaded connection preferably includes a first gear member connected to the connecting rod and a second gear member connected to the plunger, wherein the biasing means biases the first threaded member against the second threaded member such that the threads of the two threaded members do not lift off each other. Rather, the thread flanks in contact with each other remain in permanent contact with each other.

The two threaded elements are preferably arranged concentrically to the power transmission direction and in the power transmission direction, ie braced axially against each other. The axial direction substantially coincides with the longitudinal direction of the connected connecting rod. By the term "connecting rod" is understood in a broader sense of the ram moving force transmission element.

The force that biases the two threaded elements against each other is preferably greater than the expected during proper operation of the press largest, to be transferred from the connecting rod to the plunger force. Preferably, it is 1.1 to 1.2 times the force to be transmitted. If there is only one connecting rod, this is the pressing force. With two connecting rods the power is reduced to half, with four connecting rods to a quarter.

The biasing device is preferably a hydraulic device. In the preferred embodiment, the biasing means engages between a threaded member of the adjusting means connected to the connecting rod and the plunger. Alternatively, the adjusting device can also engage between the connecting rod and the plunger or the connecting rod and the threaded element which is connected to the plunger.

For example, in the former embodiment, a hydraulic piston pushes the rod-near threaded member away from the plunger against the drive direction (for example, upward). As a result, the other threaded element is also pressed up against a stop of the plunger. The thread of the two threaded elements is engaged without play.

One of the threaded elements is connected to a rotary drive device. This is preferably a remote-controllable rotary drive device, for example a hydraulic or electric drive device. The drive device preferably engages via a straight-toothed spur gear on one of the threaded elements. If the threaded element is displaced in the axial direction, for example in the event of overload, the tooth flanks of the straight-toothed gear connection can easily slide against one another without relative rotation. The rotary drive device inhibits Therefore, the axial movement of the respective threaded element not.

The biasing device can also be designed as overload protection. This, for example, if a pressure relief valve is connected to the working chamber delimited by the hydraulic piston.

Preferably, the hydraulic piston, with its

Pressing end face on one of the threaded elements, connected to the other of the threaded elements. It thus acts as a hydraulic brake or clamping. Thus, no separate brake is required for the ram adjustment.

Further details of advantageous embodiments of the invention will become apparent from the description, the drawings or claims. The description is limited to essential aspects of the invention or other circumstances. The drawing complements the description.

• Figur 1 eine Großteilpresse in schematisierter Darstellung,
• Figur 2 eine Stößelverstelleinrichtung in längs geschnittener, schematisierter Darstellung und in einem ersten Betriebszustand,
• Figur 3 die Verstelleinrichtung nach Figur 2 in einem zweiten Betriebszustand und
• Figur 4 eine abgewandelte Ausführungsform der Verstelleinrichtung in vertikal geschnittener Darstellung.

Show it:

• FIG. 1 a major press in a schematic representation,
• FIG. 2 a ram adjustment device in a longitudinally sectioned, schematic representation and in a first operating state,
• FIG. 3 the adjustment after FIG. 2 in a second operating state and
• FIG. 4 a modified embodiment of the adjusting device in a vertical sectional view.

In FIG. 1 For example, Figure 1 illustrates a press 1, which may be, for example, a stand-alone press, a press associated with a press line or a stage of a large stage press. The press 1 has a press frame 2, which may also include a press table 3 and a head piece 4. Between the head piece 4 and the press table 3, a plunger 5 is arranged, which is mounted back and forth, in the present embodiment, movable up and down. The plunger 5 carries an upper tool part 6 while the lower tool part 7 is mounted on the press table 3.

On or in the head piece 4, a drive device 8 is provided, which drives the plunger 5 via one or more connecting rods 9, 10. In the present embodiment, the connecting rods 9, 10 are driven by eccentrics. They can also be powered by other sources of power. In this respect, the term "connecting rod" includes any train and pressure claimable and tensile and compressive forces transmitting gear element.

The connecting rods 9, 10 are connected to the plunger 5 via adjusting devices 11, 12, which allow a height adjustment of the plunger. By "height adjustment" is meant in particular the adjustment of the position of the upper and lower dead center of the plunger 5, whose movement in FIG. 1 indicated by an arrow 13.

In FIG. 2 the adjusting device 11 is illustrated as representative of all other adjusting devices used on the plunger 5.

The adjusting device 11 includes a pressure pot 14, which forms a hydraulic cylinder. The outside substantially cylindrical bottom-side closed pressure pot 14 has a cylindrical interior, in which a hydraulic piston 15 is slidably mounted in the drive direction 13. The hydraulic piston 15 divides into the pressure pot 14 a working space 16 from where a hydraulic pressure pad is to build. On its underside, the pressure pot 14 is provided with a connection device 17, which serves for connection to the plunger 5.

The connecting rod 9 has at its lower end a bearing device for supporting a transverse to the connecting rod 9 extending connecting rod 18. This supports the connecting rod 9 on an adjusting spindle 19, which is cup-shaped in the present case. It has a substantially cylindrical wall, which is externally provided with a thread 20. On its underside, the adjusting spindle 19 has a bottom 21 which may be closed or, as shown, also provided with a central opening. Preferably, the bottom 21 has a flat underside 22, which also serves as a braking surface.

The thread 20 is engaged with an adjusting nut 23 which sits with little play in the pressure pot 14 and is rotatable therein. At its approximately cylindrical outer peripheral surface, it is provided with a spur toothing, which preferably extends over the entire height of its outer peripheral surface or at least over a substantial part thereof. The spur toothing is a straight toothing. The adjusting nut 23 has an internal thread 24 which is in engagement with the thread 20. The internal thread 24 and the thread 20 are in FIG. 2 illustrated opposite as a separate detail in another size representation. As can be seen, the threads each have a radially oriented and an obliquely oriented thread flank. The radially oriented thread flank of the threaded spindle 19 points upward while the radially oriented thread flank of the adjusting nut 23 points downwards. There are permanently only the radially oriented edges of the threaded spindle 19 and the adjusting nut 23 in abutment. This is effected by the hydraulic piston 15, preferably with a tubular Extension 25 against the bottom 22 presses. Around the outer periphery of the extension 25 around an annular space 26 stepped off by a step is formed, into which the adjusting nut 23 can extend.

The pressure pot 14 is closed at the top by a flange 27, which presents the adjusting nut 23 a flat annular surface 28. The flange 27 is screwed by a plurality of fastening bolts 29, 30 with the pressure pot 14.

The adjusting nut 23 is assigned an adjusting drive 31. To this belongs a gear, preferably a straight-toothed spur gear 32, the teeth of which mesh with teeth 33 of the adjusting nut 23. The gear 32 is rotatably mounted in a housing 34. It is associated with it a drive motor, for example in the form of an electric motor 35. This may be a servomotor, a torque motor, a stepping motor or the like. It may be connected to a not further illustrated encoder or encoder to detect the rotational position of the gear 32 and thereby the rotational position of the adjusting nut 23.

The working space 16 is provided with an in FIG. 2 roughly illustrated hydraulic device 36 connected, which serves to supply the working space 16 with hydraulic oil, which is under a given pressure. About not further illustrated lines, the same oil can be used for lubrication of the adjusting nut 23. The hydraulic device 36 has, for example, a pressure accumulator 37, a not further illustrated pump for filling the same with hydraulic oil, a pressure relief valve 38 and a control valve 39th

• In Betrieb steht der Arbeitsraum 16 unter einem Druck, der den an seinem Außenumfang abgedichteten Hydraulikkolben 15 gegen die Antriebskraft der Antriebseinrichtung 8 nach oben treibt. Diese Kraft ist 1,1 bis 1,2 mal so groß wie die von dem Pleuel 9 maximal auf den Stößel 5 zu übertragende Kraft. Die Stirnfläche des ringförmigen Fortsatzes 25 des Kolbens 15 drückt die Gewindespindel 21 mit entsprechender Kraft nach oben. Diese Kraft wird über die in Anlage befindlichen Flanken der Gewindegänge des Gewindes 20 und des Innengewindes 24 auf die Verstellmutter 23 übertragen, die sich somit mit ihrer oberen Stirnfläche an der Ringfläche 28 des Flansches 27 abstützt. Diese Situation bleibt während des gesamten Presshubs erhalten. Selbst in der Nähe des unteren Totpunkts, wenn das Pleuel 9 eine erhebliche nach unten gerichtete Kraft auf den Drucktopf 14 übertragen muss, bleiben die Gewindegänge des Gewindes 20 und des Innengewindes 24 in der in Figur 2 veranschaulichten Eingriffsposition. Die Druckkraft wird von der Verstellspindel 21 über den Hydraulikkolben 15 und das Druckpolster in dem Arbeitsraum 16 auf den Drucktopf 14 übertragen. Dabei wird zwar die Gewindeverbindung zwischen dem Gewinde 20 und dem Innengewinde 24 entlastet, wobei die Last jedoch nie Null wird oder ihr Vorzeichen umkehrt. Das Gewinde 20 und das Innengewinde 24 unterliegen somit einer schwellenden Last ohne Lastwechsel.

The press 1 described so far works as follows:

• In operation, the working chamber 16 is under a pressure which the sealed against its outer periphery hydraulic piston 15 against the drive force of the drive device 8 drives upward. This force is 1.1 to 1.2 times as large as the maximum of the connecting rod 9 on the plunger 5 to be transmitted force. The end face of the annular extension 25 of the piston 15 pushes the threaded spindle 21 with appropriate force upwards. This force is transmitted via the abutting flanks of the threads of the thread 20 and the internal thread 24 on the adjusting nut 23, which is thus supported with its upper end face on the annular surface 28 of the flange 27. This situation is maintained during the entire pressing stroke. Even in the vicinity of the bottom dead center, when the connecting rod 9 has to transmit a significant downward force to the pressure pot 14, the threads of the thread 20 and the internal thread 24 remain in the in FIG. 2 illustrated engagement position. The pressure force is transmitted from the adjusting spindle 21 via the hydraulic piston 15 and the pressure pad in the working chamber 16 to the pressure pot 14. Although the threaded connection between the thread 20 and the internal thread 24 is relieved, but the load is never zero or reverses its sign. The thread 20 and the internal thread 24 are thus subject to a swelling load without load change.

A rotation of the adjusting nut 23 by vibrations, swelling loads or other interference is largely excluded. By built in the working space 16 pressure pad hydraulic clamping is effected. The piston 15 presses the adjusting spindle 19 to the adjusting nut 23 and this to the flange 27 at. Thus, a rotation of the adjusting spindle 19 and the adjusting nut 23 is prevented by means of friction. A separate brake is not required.

This effect can be further enhanced if the piston 15 is stored in the pressure pot 14 untwisted. This can be done for example by an above its seal 40 in the Pressure pot 14 formed vertical groove can be achieved, in which a projection of the piston 15 can engage.

If the plunger 5 to be adjusted, the motor 35 is driven accordingly to turn the adjusting nut 23. To facilitate this, if necessary, the pressure in the working space 16 can be reduced. In the embodiment according to FIG. 2 this is simplified as pressure relief of the working space 16 via the control valve 39 illustrated. After rotation of the adjusting nut 23, the working chamber 16 is acted upon again with the full hydraulic pressure, in turn, to achieve the hydraulic clamping of the adjusting device and the bias thereof.

The adjusting device 11 also works as overload protection when 16 corresponding safety devices are connected to the working space. These may be formed, for example, by the pressure relief valve 38. Exceeds the force transmitted from the connecting rod 9 to the pressure pot 14, the force exerted by the hydraulic fluid on the piston 15 force, opens the pressure relief valve 38. The piston 15 can then, as FIG. 3 shows, dip into the working space 16. It is pushed by the bottom 22 of the adjusting spindle 19 down, wherein the adjusting nut 23 is moved downward from the annular surface 28 away. By opening the control valve 39, the working space 16 can be depressurized to eliminate blockages in the press 1. Thus, the plunger 5 can be freed from a stuck position. Subsequently, the working space 16 can be brought back to the operating pressure, so that, for example, after a damage control no further damage is recognizable, the operation of the press 1 can be continued.

During operation of the press, the force flow takes place during pressing of the connecting rod 9 via the connecting rod 18 on the adjusting spindle 19 and from this on the adjusting nut 23 on the flange 27, and from there via the fastening bolts 29, 30 to the pressure pot 14. A drop in the adjusting nut 23 and the adjusting spindle 19 is prevented by the piston 15, because this on the pressure pad with a greater force is pressed against the threaded spindle 19 as the press 1 proportionally for the connecting rod 9 has pressing force.

During the return stroke, essentially the weight of the upper tool part 6, the plunger 5 and the components of the adjusting device 11 must be accelerated upwards. The power flow extends from the plunger 5 via the fastening bolts 29, 30 of the flange 27 on via the adjusting nut 23 to the adjusting spindle 19 and the connecting rod 18 to the connecting rod. 9

Throughout the operation, zero play is achieved between the adjusting spindle 19 and the adjusting nut 23. It does not come to lifting the threads of the adjusting nut 23 and the adjusting spindle 19 from each other. This reduces the load on the adjusting device 11.

For adjusting the plunger gear 32 engages the adjusting nut 23. The straight toothing of the adjusting nut 23 is as long as the width of the gear 32 plus the length of the maximum Verstellhubs plus a small excess length. The gear 32 is mounted on a shaft. The bearing is slightly biased by a bearing cap. The shaft is driven by a direct drive e.g. an electric motor 35 is driven, which is connected via an adapter 41 to the shaft. The stator of the electric motor 35 is bolted to the housing 34. The rotation is monitored by a sensor connected to the shaft. The housing is preferably sealed.

The various adjusting drives of the various adjusting devices 11, 12 can be connected to a press by a Control preferably be controlled separately. The controller can be programmed so that the plunger safely aligns itself horizontally. For this purpose, only the difference between the table and plunger in the control is entered. The necessary adjustment paths can then be independently calculated and executed by the control. A press 1 can thus be equipped with a fully automatic ram adjustment. This considerably shortens the time required for aligning the ram during assembly or reassembly. Because it can be dispensed with the use of a hydraulic motor, the corresponding Verrohrungsaufwand is saved. In addition, no worm drive is required for the adjustment.

If necessary, instead of the hydraulically actuated piston 15, a mechanical pretensioning device can be used which, for example, clamps a disc spring package from below against the underside 22 via a hub-spindle-actuated wedge.

A modified embodiment of the adjusting device 11 shows FIG. 4 , On the basis of previously introduced reference numerals, reference is made to the previous description of the structure and function. The peculiarity lies in the fact that the adjusting spindle 19 and the piston 15 are combined to form a single component. The hydraulic pressure of the chamber 16 acts directly on the bottom 21. To guide the combined element that has the function of the adjusting spindle 19 and the function of the piston 15, a guide band 42 may be provided in the pressure pot 14. The advantage of this embodiment lies in the smaller number of parts and the lower height.

In summary, it is stated that an adjusting device 11 is provided on the press 1, which is biased by a preferably hydraulic biasing device with a force which is greater than that of the adjusting device force to be transmitted. This force eliminates load changes in the adjustment.

reference numeral

1

Press

2

press frame

3

press table

4

headpiece

5

tappet

6

Upper tool part

7

lower tool part

8th

driving means

9, 10

pleuel

11, 12

adjustment

13

Arrow / driving direction

14

pressure cooker

15

hydraulic pistons

16

working space

17

connecting device

18

Con rod

19

adjusting spindle

20

thread

21

ground

22

bottom

23

adjusting nut

24

inner thread

25

extension

26

annulus

27

flange

28

ring surface

29, 30

mounting bolts

31

adjustment

32

spur gear

33

teeth

34

casing

35

electric motor

36

hydraulic device

37

accumulator

38

Pressure relief valve

39

control valve

40

poetry

41

adapter

42

guide band

Claims (10)

Press (1), in particular the major press,
with a plunger (5) which is connected to a drive device (8) via at least one connecting rod (9),
with an adjusting device (11), via which the connecting rod (9) with the plunger (5) is connected and which contains an adjustable threaded connection (19, 23), which is associated with a biasing means (15, 16, 36). Press according to Claim 1, characterized in that the threaded connection (19, 23) has a first threaded element (19) connected to the connecting rod (9) and a second threaded element (23) connected to the plunger (5) and that the biasing means (15, 16, 36) biases the first threaded member (19) against the second threaded member (23). Presses according to claim 2, characterized in that both threaded elements (19, 23) are arranged concentrically to a power transmission direction (13). Presses according to claim 3, characterized in that the threaded elements (19, 23) in the power transmission direction (13) are braced against each other. Presses according to claim 1, characterized in that the pretensioning device (15, 16, 36) generates a force which is greater than that expected from the connecting rod (9) on the plunger (5) when the press (1) is in proper operation. force to be transmitted. Press according to claim 1, characterized in that the biasing means (15, 16, 36) generates a force acting between a threaded element (19) of the adjusting device (11) connected to the connecting rod (9) and the plunger (5) , Press according to claim 2, characterized in that the biasing means (15, 16, 36) comprises a hydraulically actuable piston (15) which is supported in the axial direction on one of the threaded elements (19). Presses according to claim 7, characterized in that the piston (15) with the other of the threaded elements (23) or the adjusting device (11) is rotatably connected. Presses according to claim 1, characterized in that the adjusting device (11) is associated with a rotary drive device (35). Presses according to claim 1, characterized in that the biasing means (15, 16, 36) has an overload protection or is connected to such.

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