EP2483065A1

EP2483065A1 - Method for moving a machining unit of a machine

Info

Publication number: EP2483065A1
Application number: EP10771643A
Authority: EP
Inventors: Bernard De Muynck
Original assignee: Haco NV
Current assignee: Haco NV
Priority date: 2009-10-01
Filing date: 2010-10-01
Publication date: 2012-08-08
Also published as: DE102009043729A1; WO2011038921A1

Abstract

The invention relates to a method for moving a machining unit (2) of a machine, in particular a press, wherein the movement comprises at least an approach phase and a subsequent machining phase, wherein during the approach phase the machining unit (2) approaches or is brought in contact with a workpiece to be machined, and wherein the machining unit (2) exerts force on the workpiece during the machining phase by moving the machining unit (2) while the same is in constant contact with the workpiece. The machining unit (2) is moved by means of a servo-mechanical drive unit during the approach phase and by means of a hydraulic drive unit during the machining phase.

Description

Method for moving a machining unit of a machine

The invention relates to a method for moving a processing unit of a machine, in particular press, wherein the moving comprises at least one approach phase and an adjoining processing phase, wherein the processing unit is approached or brought into contact with a workpiece to be machined during the approach phase, and wherein the processing unit applies force to the workpiece during the processing phase by moving the processing unit while in constant contact with the workpiece.

Furthermore, the invention relates to a device for moving a processing unit of a machine and a correspondingly configured machine.

Methods of the above type are commonly used in machines such as presses or the like. They are used to process a workpiece. As a processing unit, for example, a ram is provided, which is initially approximated or brought into contact with the workpiece to be machined during an approach phase. This is followed by a processing phase during which the processing unit or ram exerts force on the workpiece in order to machine it in a desired manner. In this case, the processing unit is in constant contact with the workpiece in order to realize the power transmission necessary for machining the workpiece.

CONFIRMATION COPY To clarify the conventional method for moving a processing unit of a machine, known configurations of presses will be described below. A distinction is made between hydraulic, mechanical and servo-mechanical presses.

A hydraulic press is conventionally equipped with at least one hydraulic drive unit having a hydraulic cylinder and a hydraulic unit driving it. The hydraulic unit usually has an electric motor and a plurality of controllable valves. The output side connected to the hydraulic cylinder processing unit is moved both during the approach phase, as well as during the processing phase exclusively by means of the hydraulic drive unit. Hydraulic presses can be operated manually or controlled by a computer. An advantage of hydraulic presses is that an exact control of the movement of the hydraulic cylinder and thus the processing unit moved therewith can take place in any phase of movement. Furthermore, even large forces can be generated and transmitted at any hydraulic cylinder position. Hydraulic presses are therefore very flexible and adaptable to the particular application. On the other hand, it is disadvantageous that the processing unit can only be moved relatively slowly by means of the hydraulic cylinder or that there is a need for a costly high-performance hydraulic unit or other special devices in order to obtain sufficient movement speeds for the processing unit.

A mechanical press has a mechanical drive system, on the output side, the processing unit is arranged and which is driven by a flywheel. This is in turn driven by an electric motor. With mechanical presses, in contrast to hydraulic presses, relatively high speeds of movement can be achieved for the processing unit. Another advantage is the high rigidity of mechanical presses, so that even when large machining forces occur, it is ensured that ideal machining of a workpiece can take place. A disadvantage, however, is that the flywheel and thus also the mechanical drive system driving electric motor must be constantly turned on, which associated with high energy consumption. In addition, the movement of the processing unit is determined by the particular design of the mechanical drive system and not adaptable to other purposes, whereby a mechanical press is not flexible. Another disadvantage is that a large force can be applied only in the last few millimeters of the stroke of the processing unit. The mechanical drive systems of mechanical presses are also usually relatively complicated and expensive.

Servo-mechanical presses also have a mechanical drive system, as known from mechanical presses. However, this is not driven by a flywheel but via a servo drive. The servodrive is, for example, given as an "electric flywheel", in particular in the form of a large battery of capacities.Thus, with servo-mechanical presses, high speeds of movement can also be realized for the processing unit.With the use of the servo drive, the movement sequence of the processing unit can be precisely controlled, programmed Servo-mechanical presses also have a relatively lower energy consumption because energy can only be obtained from a power supply network when necessary and excess energy can be stored, which also has the disadvantage that power is only available in the last few years a few millimeters of the stroke of the processing unit can be applied.

Based on this prior art, it is the object of the invention to provide a method for moving a processing unit of a machine, in particular press, which combines the advantages known from conventional methods and at the same time allows a precisely controllable, fast and flexible application of a workpiece.

This object is achieved by the method of the aforementioned type in that the movement of the processing unit during the approach phase by means of a servo-mechanical drive unit and during the processing phase by means of a hydraulic drive unit.

According to the invention, a servo-mechanical drive unit is thus combined with a hydraulic drive unit such that the advantages of these drive types are maintained. The servo-mechanical drive unit is used during the approach phase and the hydraulic drive unit during the processing phase. Both drive types allow a very exact and at the same time application-specific control of a machine operated according to the method according to the invention. Thus, such a machine can be used very variable. Another advantage is that a large force can be applied not only in the last few millimeters of movement of the processing unit, as it is known from the conventional mechanical and servo-mechanical presses. Just this weakness of known presses is circumvented by the fact that the power transmission is effected by means of the hydraulic drive unit. This allows, in addition to a very individual power transmission, a very exact and application-specific control of the movements of the processing unit.

Preferably, most of the total movement of the processing unit is covered by the servo-mechanical drive unit during the approach phase. As a result, the amount of movement attributable to the processing phase of the entire movement is relatively small. Consequently, both the hydraulic cylinder and the cooperating hydraulic unit can be made relatively small, which has a favorable effect on the energy consumption of a machine operated according to the method according to the invention. In addition, this relatively fast movements of the processing unit can be realized, which is anyway possible with the servo-mechanical drive unit, as described above. Consequently, the processing unit can be moved relatively quickly over its entire stroke. At the same time, the desired movement sequence of the machining unit and the resulting force transmission to a workpiece to be machined is very precisely controlled and optimally adapted to the particular application, as is apparent from a comparison of the above descriptions of hydraulic and servo-mechanical presses. One according to the invention Consequently, the machine operated according to the method has a very high flexibility of use.

The servo-mechanical drive unit can be designed in a conventional manner. However, as a result of the method according to the invention, a less complex servo-mechanical drive unit can also be used by using a simple and cost-effective designed mechanical part and / or servo drive.

Another advantage is that no flywheel and no clutch / brake system as mechanical presses are required. Furthermore, the energy requirement of a machine operated according to the method according to the invention is relatively low, in particular since energy can be fed back into the utility grid. Also, for example, pendulum-like movements of the processing unit are possible.

With the method according to the invention differently configured machines can be operated. In particular, presses can be operated according to the inventive method. In principle, however, any type of machine is operable by the method according to the invention, in which an approach phase and an adjoining processing phase are given. Examples of such machines are stamping presses, deep drawing presses, blanking presses, forging presses, stamping presses, transfer presses, punch presses, press brakes, shears and the like.

The processing unit is preferably moved cyclically, with a retraction phase following the processing phase during which the processing unit is moved, for example, counter to its direction of movement during the approach phase and the processing phase. A movement cycle ends with the completion of the withdrawal phase. Subsequently, another cycle of movement can take place. In the method according to the invention, the movement cycles of the processing unit can be controlled exactly and individually in order to be able to optimally adapt the method to the respective intended use of a machine operated thereafter. According to an advantageous embodiment of the invention, the processing unit is moved linearly during the approach phase over an approach path and during the processing phase over a processing path, the lengths and endpoints of these routes are individually adjustable and adaptable to each other. This embodiment of the invention serves to provide a great versatility of a machine operated according to the method. Such a linear movement takes place, for example, in forging presses. The transition between the approach route and the processing route is free and selectable in accordance with the particular circumstances in order to be able to optimally adapt the method or a machine operated thereafter to the respective intended use.

The invention further proposes a device of the aforementioned type which has a servo-mechanical drive unit and a hydraulic drive unit arranged on the output side thereof, on the output side of which the processing unit is arranged.

With the device according to the invention, the method according to one of the above-described embodiments or their arbitrary combination is preferably feasible. Here, first of all, a movement of the processing unit takes place by means of the servo-mechanical drive unit during the approach phase, followed by the processing phase in which the processing unit is moved by means of the hydraulic drive unit.

Advantageously, the device is set up such that the processing unit is initially approximated or brought into contact with a workpiece to be machined by the servo-mechanical drive unit up to a predeterminable distance, and that the processing unit subsequently by means of the hydraulic drive unit for machining the workpiece is moved, wherein the processing unit while it is in contact with the workpiece is force exerted on this.

A further advantageous embodiment of the invention provides that the servo-mechanical drive unit comprises at least one connecting rod driven by an eccentric, on the output side of which the hydraulic drive unit is arranged. This represents a simple and application-specific realization of the device according to the invention. The eccentric may be formed as a separate component or be part of an eccentric shaft, which is driven by the servo drive.

The invention further proposes a machine, in particular a press, of the aforementioned type, in which the processing unit is moved according to the method according to one of the previously described embodiments or any combination thereof.

It is further proposed by the invention, a machine, in particular press, of the aforementioned type, which is characterized by a device according to one of the above-described embodiments or any combination thereof. Advantageously, this machine is moved according to the method of any of the above-described embodiments or any combination thereof.

Further advantages and features of the present invention will be explained in more detail below with reference to the embodiments shown in the figures. Show

Figure 1: a schematic representation of a

Embodiment of the device according to the invention,

FIG. 2 shows an exemplary sinusoidal movement path of a processing unit moved by means of the method according to the invention;

FIGS. 3 to 7: alternative exemplary movement paths of the processing unit.

1 shows schematically an embodiment of the device 1 according to the invention or a section of an embodiment of the machine according to the invention, which is provided with a corresponding Vorrich- 1 is equipped. The device 1 has a servo-mechanical drive unit, with which the processing unit 2, which is designed as a ram plate, during the approach phase can be brought to an unillustrated, to be machined workpiece or brought into contact with this.

The servo-mechanical drive unit comprises a connecting rod 3, which is driven via an eccentric shaft 4 by a servo drive, not shown. In this case, the speed and the respective position of the servo drive can be detected, for example via a sensor device on the transmission of the servo drive. On the basis of this detected speed and / or position data, the movement of the servo-mechanical drive unit and thus of the processing unit 2 can be controlled exactly and application-specifically by means of a control device, not shown. In order to be able to adapt the servo-mechanical drive unit to the respective intended use of the device 1 or of a machine equipped therewith, for example, the length of the connecting rod 3 can be varied via an adjusting mechanism.

The eccentric shaft 4 is shown in an upper and a lower position, wherein the upper position of the maximum lower approach position and the lower position of the shaft 4 corresponds to the upper dead center of the movement of the processing unit 2. The arrow 5 indicates the maximum stroke of the processing unit 2 during the approach phase. The maximum lower approach position corresponds to that position of the processing unit 2, in which the processing unit 2 has been approached or brought into contact with a workpiece to be machined during the approach phase to a predeterminable suitable distance. In this position, the servo-mechanical drive unit should have taken a blocking position, from which the drive unit can not be crowded when force is applied to a workpiece to be machined by means of the processing unit 2 in the subsequent processing phase. From reaching the maximum lower approach position, the processing phase preferably begins directly or after a time delay. On the output side, a piston 6 is articulated on the connecting rod 3, which is slidably guided in a guide 7 and thus can perform a linear movement. On the output side of the piston 6, in turn, the hydraulic drive unit is arranged. This has a hydraulic cylinder 8, in which the lower portion of the piston 6 is slidably guided. The lower part of the piston 6 is sealed by a seal 9 with respect to the hydraulic cylinder 8. The hydraulic cylinder 8 is arranged movable in the direction of the arrow 10 relative to the guide 7.

On the hydraulic cylinder 8, a holding plate 11 is arranged on the output side, on which in turn the output side designed as a ram plate processing unit 2 is attached. The arrow 10 indicates the maximum stroke of the processing unit 2 during the processing phase, which can be achieved by activating the hydraulic drive unit. For exact control of the movement of the processing unit 2 during the processing phase, the respective position of the ram is detected by a position sensor 12 and passed on to the control device, not shown. The ram is movably guided in a frame 13, which has sufficient rigidity.

FIG. 2 shows a sinusoidal movement path of the processing unit of a machine. The approach phase takes place from the top dead center OT, that is to say the beginning of the approach phase, to a prescribable maximum approach point AP, which corresponds to a position machining unit in which the machining unit approaches or is in contact with a workpiece to be machined up to a predefinable distance stands. From the maximum approach point AP, which corresponds to the end of the approach phase carried out with the servo-mechanical drive unit, the machining phase during which the machining unit 2 is moved by the hydraulic drive unit to a bottom dead center UT begins a desired machining of the workpiece to be machined bring about. After reaching the bottom dead center UT, the retraction phase begins, during which both the servo-mechanical drive unit and the hydraulic drive unit initiate a return movement of the processing unit. cause unity to the upper dead center OT. The movement sequence of the processing unit shown in FIG. 1 corresponds to a movement cycle.

FIG. 3 shows a movement path of the processing unit that is alternative to FIG. 2, wherein three movement cycles are shown. In this case, a relatively rapid approach of the processing unit to a workpiece to be machined initially takes place from the top dead center OT to the maximum approach point AP by means of the servo-mechanical drive unit. Subsequently, a slower movement of the processing unit by means of the hydraulic drive unit during the processing phase from the maximum approach point AP to the bottom dead center UT. Finally, the withdrawal phase takes place.

FIG. 4 shows a further alternative movement path of the processing unit, wherein two movement cycles are shown. First, a relatively fast approach of the processing unit to a workpiece to be machined during the approach phase from the top dead center TDC to the maximum approach point AP. This is followed by a time delay of the movement up to the point X, which can be specified in accordance with the application, until the beginning of the processing phase. When the point X is reached, the machining phase takes place by means of the hydraulic drive unit, during which the machining unit is moved to the lower dead center UT in order to machine the workpiece in a desired manner. From reaching the bottom dead center UT, the retraction phase begins during which the processing unit is first moved to the point Y quickly by means of the hydraulic drive unit and then slightly slower by means of the servo-mechanical drive unit to the top dead center OT.

FIG. 5 shows a further alternative movement path of the processing unit, wherein three complete movement cycles are shown. Such movement cycles can be used, for example, in a deep-drawing press. In contrast to the sequence of movements shown in FIG. 4, according to FIG. 5 there is no time delay of the movement and it finds one relatively fast movement during the machining phase. Subsequently, the retraction phase takes place again.

FIG. 6 shows a further alternative movement path of the processing unit, wherein three movement cycles are shown. This type of movement is preferably used in a deep-drawing press. In contrast to the sequence of movements shown in FIG. 5, there is a time delay of the movement in the lower dead center UT from the point UT1 to the point UT2 before the retraction phase begins.

FIG. 7 shows a further alternative movement path of the processing unit, wherein a complete cycle of movement is shown. Such a movement cycle is used, for example, in a stamping press. From reaching the maximum approach point AP is a processing phase, during which the processing unit by means of the hydraulic drive unit executes a pendulum motion. In order to maintain the clarity of Figure 7, is dispensed with a more detailed identification of the movement sequence shown.

All points shown in FIGS. 2 to 7 between different movement phases can be specified in an application-specific manner according to the method according to the invention, so that a machine operated according to this method can operate very energy-efficiently and can be used very flexibly. At the same time, fast movement sequences of the processing unit can be realized. In addition, the speeds of the processing device can be varied in many ways and adapted to the particular application.

The embodiments described with reference to the figures are illustrative and not restrictive.

The method according to the invention and the device for carrying out the method can be used for rolling, deep drawing, cutting, forging, punching and the like. Accordingly, the invention also relates to stamping presses, deep drawing presses, cutting presses, forging presses, Die presses, step presses, hole punches, press brakes, hydraulic shears and the like, as well as other devices that are operated by the method according to the invention.

Claims

claims

1. A method for moving a processing unit (2) of a machine, in particular press, wherein the moving comprises at least one approach phase and an adjoining processing phase, wherein the processing unit (2) during the approach phase approximated to a workpiece to be machined or in contact therewith and wherein the machining unit (2) applies force to the workpiece during the machining phase by moving the machining unit (2) while being in constant contact with the workpiece, characterized in that moving the machining unit (2) during the approaching phase by means of a servo-mechanical drive unit and during the processing phase by means of a hydraulic drive unit.

2. The method according to claim 1, characterized in that the major part of the total movement of the processing unit is covered by the servo-mechanical drive unit during the approach phase.

3. The method according to claim 1 or 2, characterized in that the processing unit (2) is cyclically moved, wherein the processing phase followed by a retraction phase during which the processing unit (2) is moved opposite to its direction of movement during the approach phase and the processing phase ,

4. The method according to any one of the preceding claims, characterized in that the processing unit (2) is moved linearly during the approach phase over an approach path and during the processing phase over a processing path, the lengths and endpoints of these routes are individually adjustable and adaptable to each other.

5. Device (1) for moving a processing unit (2) of a machine, in particular press, comprising a servo-mechanical drive unit and a driven side arranged thereon hydraulic drive unit, on the output side, the processing unit (2) is arranged.

6. Device (1) according to claim 5, characterized in that the hydraulic drive unit comprises a hydraulic cylinder, with which the processing unit (2) is movable relative to the servo-mechanical drive unit.

7. Device (1) according to any one of claims 5 or 6, characterized in that the servo-mechanical drive unit comprises at least one driven via an eccentric connecting rod (3), on the output side, the hydraulic drive unit is arranged.

8. Device (1) according to one of claims 5 to 7, characterized in that it is set up such that the processing unit (2) by means of the servo-mechanical drive unit initially approximated to a predetermined distance to a workpiece to be machined or with this is brought into contact, and that the processing unit (2) is then moved by means of the hydraulic drive unit for machining the workpiece, wherein the processing unit (2) while it is in contact with the workpiece exerts force on this.

9. Machine, in particular press, for processing a workpiece, comprising a processing unit (2), characterized in that the processing unit (2) according to the method according to one of claims 1 to 4 is moved.

10. Machine, in particular press, for processing a workpiece, comprising a processing unit (2), characterized by a device according to one of claims 5 to 8.

11. Machine according to claim 10, characterized in that the processing unit (2) according to the method of any one of claims 1 to 4 is moved.