Machine tool

Abstract

Machine tools for machining or processing a workpiece can include at least one tool with at least one relative movement between the workpiece and the tool. The machine tool has at least one pressure line circuit with at least one pump unit and with at least one energy storage which is in flow connection with the pump unit via a pressure line, wherein the pump unit has at least one mechanically driven pump element for sucking in or sucking out a medium and is in flow connection with the pressure line, and the pump element is mechanically coupled to a component of the machine tool which is also moved during proper operation of the machine tool in such a way that the component moved by the machine tool drives the pump element.

Claims

1. An apparatus for machining or processing a workpiece that can be positioned in a workpiece holder, comprising: at least one tool that is movable relative to the workpiece holder during the machining or processing of the workpiece, wherein the apparatus is a press device for the form-pressing of workpieces, and includes a component movable by the press device in a reciprocal stroke movement during the machining of the workpiece; and at least one pressure line circuit having at least one pump unit and at least one energy storage, which is in flow connection with the pump unit via a pressure line, and a pressure outlet, at which a pressure difference present in the energy storage with respect to the ambient pressure can be tapped via a pressure supply line that runs from the energy storage to a pneumatic consumer; wherein the pump unit has at least one mechanically driven pump element movable back and forth for sucking in or sucking out a medium and being in flow connection with the pressure line; and wherein the pump element is directly or indirectly mechanically coupled to the apparatus in such a way that during the machining or processing of the workpiece the pump element is driven by movement of the tool; wherein the pump unit is a compressor in the form of a piston/cylinder unit for building up a pneumatic overpressure arranged to suck in a gaseous medium and press it into the pressure line in a compressed state, wherein the energy storage is a pneumatic pressure storage with a pressure vessel with an internal pressure which is higher than the ambient pressure, wherein the pump unit is a piston/cylinder unit; wherein a piston of the piston/cylinder unit is coupled to the stroke movement of the movable component of the press device, and the piston/cylinder unit has a working chamber arranged on one side of the piston; wherein the working chamber is in flow connection with the pressure line having a pressure valve; wherein the pressure valve in the case of a pump unit that is a compressor permits a flow from the piston/cylinder unit to the pneumatic energy storage, and is capable of blocking automatically in the opposite direction, or in the case of a pump unit that is a suction unit permits a flow from the pneumatic energy storage to the piston/cylinder unit and is capable of blocking automatically in the opposite direction; wherein the press device comprises two separate pressure line circuits, each of the pressure line circuits comprising at least one energy storage and a pressure line; and wherein one of the pressure line circuits is a pressure line circuit carrying over-pressure with a compressor as pumping unit, and one of the pressure line circuits is a pressure line circuit carrying under-pressure with a suction unit as pumping unit.

2. The apparatus of claim 1, wherein at least one pump unit is a suction unit for building up a pneumatic vacuum for sucking gaseous medium out of the pressure line, wherein the pneumatic energy storage is a pressure vessel with an internal pressure which is lower than the ambient pressure.

3. The apparatus of claim 1, wherein at least one pump unit is a pump for building up a hydraulic pressure arranged for sucking in a fluid and pressing it into the pressure line, wherein the energy storage is a storage for storing potential energy, which has a device for converting a hydraulic pressure into potential energy and potential energy into hydraulic pressure.

4. The apparatus of claim 1, wherein the piston/cylinder unit has a respective working chamber on both sides of the piston, one of the working chambers being in flow communication with a first pressure line circuit carrying negative or positive pressure, and a second working chamber arranged on the opposite side of the piston being in flow communication with a second pressure line circuit carrying positive or negative pressure.

5. The apparatus of claim 1, wherein the pneumatically driven consumer is an overpressure-driven ejector mandrel or a vacuum-driven suction cup as part of a workpiece handling system.

6. The apparatus of claim 1, further comprising, at least one press plunger which can be set in a lifting movement against the abutment surface, wherein the movable component is the press plunger or a component of the press device connected to a lifting rod of the press plunger.

7. The apparatus of claim 6, wherein a stroke rod is cylindrically hollow at least in parts of the stroke rod, and forms the cylinder of the piston/cylinder unit.

8. An apparatus for machining or processing a workpiece that can be positioned in a workpiece holder, comprising: at least one tool that is movable relative to the workpiece holder during the machining or processing of the workpiece, wherein the apparatus is a press device for the form-pressing of workpieces, and includes a component movable by the press device in a reciprocal stroke movement during the machining of the workpiece; and at least one pressure line circuit having at least one pump unit and at least one energy storage, which is in flow connection with the pump unit via a pressure line, and a pressure outlet, at which a pressure difference present in the energy storage with respect to the ambient pressure can be tapped via a pressure supply line; wherein the pump unit is a compressor for building up a pneumatic overpressure arranged to suck in a gaseous medium and press it into the pressure line in a compressed state, wherein the energy storage is a pneumatic pressure storage with a pressure vessel with an internal pressure which is higher than the ambient pressure; wherein the pump unit has at least one mechanically driven pump element movable back and forth for sucking in or sucking out a medium and being in flow connection with the pressure line; and wherein the pump element is directly or indirectly mechanically coupled to the apparatus in such a way that during the machining or processing of the workpiece the pump element is driven by movement of the tool; wherein the pump unit is a compressor in the form of a piston/cylinder unit for building up a pneumatic overpressure arranged to suck in a gaseous medium and press it into the pressure line in a compressed state and energy storage is a pneumatic pressure storage with a pressure vessel with an internal pressure which is higher than the ambient pressure; and wherein a piston of the piston/cylinder unit is coupled to the stroke movement of the movable component of the press device, and the piston/cylinder unit has a working chamber arranged on one side of the piston; wherein the working chamber is in flow connection with the pressure line having a pressure valve; wherein the pressure valve permits a flow from the piston/cylinder unit to the pneumatic energy storage, and is capable of blocking automatically in the opposite direction; wherein the apparatus comprises a pressure supply line having a controllable control valve and which runs directly to one or more pneumatically loaded consumers which are in flow connection with the energy storage via the pressure supply line or wherein the pressure supply line runs from the pneumatic energy storage to a transfer point at which compressed air is tapped via a suitable interface, wherein the press device has at least one abutment surface and at least one press plunger which can be set in a lifting movement against the abutment surface, wherein the movable component is a lifting rod of the press plunger and the lifting rod includes a hollow cylindrical area that forms the cylinder of the piston/cylinder unit such that the pump unit is integrated into the lifting rod, and wherein the pump element is guided upwards through the hollow cylindrical area of the lifting rod and is connected with an area of the machine tool that does not move with the lifting rod.

Description

SUMMARY OF THE DRAWINGS

(1) Further fields of application, features and advantages of the present subject matter are described in the following examples of the design of a machine tool on the basis of the drawings. The following description of these preferred examples and also the above description is to be understood in such a way that it serves only to illustrate the basic ideas of the invention, but does not limit the scope and extent of the present invention.

(2) In the drawings:

(3) FIG. 1 shows a schematic view of a first configuration of the machine tool designed as a pressing device with a pump unit for generating an overpressure,

(4) FIG. 2 shows the area of the pumping unit similar to the design according to FIG. 1, where the pumping unit is turned over to create a vacuum,

(5) FIG. 3 shows a variant of the machine tool designed as a pressing device with a pressure circuit, but where both movements are used to generate an overpressure,

(6) FIG. 4 shows a variant of the machine tool designed as a pressing device with two pressure circuits and two energy storage systems,

(7) FIG. 5 shows the machining area of a machine tool designed as a boring mill with conversion of the rotational movement of the machining area into a translational movement of the pumping element, and

(8) FIG. 6 shows shows a schematic view of a further design of a machine tool designed as a pressing device with a pump unit integrated in the press ram.

DESCRIPTION WITH REFERENCE TO THE DRAWINGS

(9) FIG. 1 shows a schematic view of a first possible design of the pressing device. This pressing device has a lifting rod 4, on which the press plunger 1 is provided in the lower area. The press plunger 1 is placed against an abutment surface 2, in which a mold cavity 3 for molding a workpiece not shown here is arranged.

(10) In the design shown, a pneumatic consumer in the form of an ejector mandrel 11 is provided below the abutment surface 2. In order to be able to operate this without a separate compressed air connection, the machine is designed to be self-sufficient and has its own compressed air generation. The compressed air is generated by the pump unit 5, which is designed here as a piston/cylinder unit.

(11) The piston/cylinder unit has a fixed cylinder in which a movable piston is moved back and forth, with the lower end of its piston rod, which forms the pump unit 5, resting on the surface of the press plunger 1. This connection with the press plunger 1 causes the piston to be both pushed up and pulled down, thus moving synchronously with the press plunger 1. The connection and geometry shown is of course only schematic, all other types of connections can be used here.

(12) The piston/cylinder unit comprises a first working chamber 15 above the piston crown forming the pump unit 6, and a second working chamber 16 below the piston crown, which is not used in the example of FIG. 3. In the upper area, the suction possibility for ambient air, which is provided by an inlet valve, is shown.

(13) Pressure lines 8 extend from the pump unit 5 to the pneumatic energy storage 7. To avoid larger pressure fluctuations in the pneumatic energy storage 7, a pressure control valve 14 is provided in pressure line 8 directly upstream of the pneumatic energy storage 7. Pressure valves 12, 13 control the function so that in the event of an excess pressure in the working chamber 15, 16 of the pump unit 5, this excess pressure is passed on to the pneumatic energy storage 7, while in the case of a vacuum, the respective pressure valve 12, 13 closes due to the opposite movement of the piston, thus preventing the air from being sucked back.

(14) The pneumatic energy storage 7 in turn is connected to the pneumatic consumer 9 via a pressure supply line 10 with a switching valve in the design example shown. This pneumatic consumer 9 is also a piston/cylinder unit which uses the excess pressure in the pressure supply line 10 to move the ejector mandrel. The return of this mandrel can be spring-operated, for example. A switching valve is assigned to the pneumatic consumer 9, via which the excess pressure can be released to reset the ejector mandrel. This requires, via the load of the next workpiece lying in the mold cavity 3, the pressure of the press plunger 1, the weight of the piston or, if this is not sufficient, via a return spring (not shown here).

(15) FIG. 2 shows a variant of the machine tool designed as a pressing device as shown in FIG. 1. In this case, pump unit 5 is used differently to generate a vacuum, so that pressure valve 12 closes when the piston of pump unit 5 is raised and still used as pump unit 6, and opens when the piston is lowered, so that gaseous medium can be sucked out of the energy storage 7.

(16) FIG. 3 shows a further variation. Here, the pump unit 5 is designed in such a way that both movements in the forward and backward direction of the pump unit 6 can be used to generate overpressure. For this purpose, a pressure outlet is provided both in the upper area of the piston and in the lower area of the piston, which is in flow connection with pressure line 8 via a pressure valve 12, 13.

(17) FIG. 4 shows a variant with two pressure circuits and two energy storage devices 7, 7. A second pneumatic energy storage 7 is thus provided here, whereby the pump unit 5 here also has two working chambers 15, 16. In contrast to the design of the invention shown in FIG. 3, however, here the two working chambers 15, 16 are connected to different pressure line circuits. Via the pressure line 8, the lower working chamber 16 is connected to the pneumatic energy storage 7, which here also has a pressure control valve 14. In this respect this function does not differ from the function shown in FIG. 1.

(18) The upper working chamber 15, on the other hand, interacts with another pressure line circuit which is connected to the second pneumatic energy storage 7, which also has a pressure regulating valve 14. The pressure valve 12 is intended here to form a vacuum pump, so that the piston of the pumping element 6, which generates a vacuum in the second working chamber 15 when shutting down, sucks the air out of pressure line 8 of this second pressure line circuit.

(19) If the piston now moves up again, the air in the piston is expelled after closing the pressure valve 12 via an expulsion opening not shown here, which is closed via a valve which does not work in the opposite direction to the pressure valve 12. Of course, this ejection opening could also be connected to the first pressure line circuit, so that the same working chamber 15 can be used on the one hand as a suction chamber and on the other hand as a chamber generating overpressure. This also applies, of course, to the opposite side of the piston crown in the area of working chamber 16 located there in the case of the variant shown in FIG. 3.

(20) As an example, here the second pneumatic reservoir 7 is combined with a suction chamber, which can be used as a gripper as a pneumatic consumer 9 for the workpiece and can be moved, for example, by means of a robot-like arm. The design of the first pressure line circuit and its connection to the first pneumatic consumer 9 is no different from the variant described in connection with FIG. 1.

(21) FIG. 5 shows a variant of the machine tool, which is designed as a boring mill or drilling machine with a drilling tool 17. Here only the area of the machining medium, the pump unit 5 and the energy storage 7 is shown. Behind the pump unit 5 the pressure line 8 and the energy storage 7 with the valve means already described above are provided. This area does not differ from the variants described above. In the version shown, an overpressure is generated, but the variant shown in FIG. 2 can also be implemented just as well to generate a negative pressure in connection with this machine tool.

(22) It can be seen here that in an exemplary design, the spindle of the machining means of the machine tool has an external toothing which meshes with a schematically shown gear wheel arranged next to it. As a result, this gearwheel is set in rotation, which is converted into a translatory movement of the pump unit 6 via the lever gear shown below.

(23) FIG. 6 shows a further variant of the machine tool, which is also designed as a pressing device. Here the pump unit 5 is integrated into the lifting rod 4, which forms the punch of the press. The pump unit 6 is guided upwards through a hollow cylindrical area of the lifting rod 4 and with an area of the machine tool that does not move with the lifting rod 4. The design shown is only an example, many variants are possible. Since in this design the pump unit 5 moves with the tool, i.e. the lifting rod 4, the front area of the pressure line 8 upstream of the pressure valve 12 is designed as an elastic line, at least in sections, so that the pressure outlet from the pump unit 5 can move with the tool.

LIST OF REFERENCE SIGNS

(24) 1 Press plunger 2 Abutment surface 3 Mold cavity 4 Lifting rod 5 Pump unit 6 Pump element 7, 7 Pneumatic energy storage 8 Pressure line 9, 9 Pneumatic consumer 10 Pressure supply line 11 Ejector mandrel 12 Pressure valve 13 Pressure valve 14 Pressure control valve 15 Working room 16 Working room 17 Drilling tool