Patent Application
20150090132
The invention relates to hydraulic extrusion presses having a main hydraulic line that drives at least one ram as the main consumer, and having a hydraulic control pressure system. Likewise, the invention relates to a method for operation of a hydraulic extrusion press having at least one ram, in which at least the ram is driven by means of hydraulic oil from a main line, and a hydraulic control pressure is used for control of the extrusion press.
Such extrusion presses are sufficiently known from the state of the art, whereby extrusion as such is a forming method in which heavy metal blocks or light metal blocks, also called bolts, preferably preheated, are pressed through a die or through a matrix, using a hydraulic ram, to produce strand-like semi-finished products, generally called profiles.
The common hydraulic drives for the ram of these presses consist of a machine-dependent number of main pumps, which can be switched on as needed, by way of line valves for different consumer groups, such as multiple cylinders, for example, in which pistons for the hydraulic ram run.
By means of corresponding pump switching and consumer circuits, one axle, in each instance, can be driven at the same time with individual axles of other consumer groups. In this connection, it is generally possible to interconnect pumps on the different lines, whereby the movement sequences and speeds are defined and controlled by way of the pump assignment and the related conveying stream regulation of the pumps. Extrusion presses are built for different pressing forces, at the present time in a spectrum between approximately 10 MN and approximately 150 MN. Different pressing forces and therefore pressing pressures result from the tool geometry or profile geometry and the pressing method, for the machine size, in each instance, and thereby different method pressures for the main axles outside of the pressing process occur.
For this reason, hydraulic extrusion presses generally have a separate control pressure system, in order to ensure that a corresponding control pressure is available at all times, for example for a valve controller or pump drives, with sufficient operational reliability.
In this connection, it is understood that non-productive periods are unavoidable during backward movement of a ram and when loading a new block or bolt, or during other setup activities, during which times a corresponding extrusion press is not productive. Accordingly, it is the task of the present invention to minimize the non-productive periods.
As a solution, a hydraulic extrusion press of the stated type and a method of the stated type, for operation of a hydraulic extrusion press, having the characteristics of the independent claims are proposed.
In this connection, for example, non-productive periods can be reduced by means of a hydraulic extrusion press having a main hydraulic line that drives at least one ram as the main consumer, and having a hydraulic control pressure system, which press is characterized in that the main line and the control pressure system are connected with one another on the pressure side, because oil from the control pressure system or control oil is also available, under certain circumstances, particularly if large oil volume streams are required in the main line.
Accordingly, the non-productive periods can also be reduced by means of a method for operation of a hydraulic extrusion press having at least one ram, in which at least the ram is driven by means of hydraulic oil from a main line, and a hydraulic control pressure is used to control the extrusion press, and which method is characterized in that the control pressure is also applied to the main line.
In this connection, one particularly proceeds from the main recognition that non-productive periods, as such, can also be reduced by means of an increase in the total output of an extrusion press, in that larger and longer blocks or bolts, in particular, can be pressed. This accordingly leads to a proportional reduction in the non-productive periods, whereby here, however, the control pressure pumps, as a function of the pressing cycles, over long phases, merely continue to serve for balancing out leakage oil losses and, for the remainder, swinging back to a low conveying stream, so that they are utilized only slightly. The latter is reinforced even more in the case of a design of extrusion presses toward larger or longer blocks or bolts, whereby ultimately, corresponding lower dimensioning of the control pressure pumps is possible only in very limited manner, for reasons of operational reliability, because the required control pressures must be available at all operation times.
The use of control oil in backward movements, for example, where large volumes generally have to be moved at low pressures, can lead to non-productive period reductions between 0.5 and 0.8 seconds or more—even in the case of a careful estimate as has already been shown in experiments. It is assumed that even in the case of other movement sequences, further reductions in the non-productive periods can be achieved, so that in this regard, noteworthy reductions of the total non-productive periods can be achieved, particularly without having to increase the overall design of the extrusion press, particularly with regard to its performance characteristics, in noteworthy manner, which is relatively advantageous, particularly also with regard to the costs for an extrusion press equipped in corresponding manner, because ultimately, only relatively cost-advantageous additional components, such as, for example, a supplemental connection line and possible valves or temporary storage devices for oil have to be used.
In this regard, the non-productive periods can be shortened without an increase in the drive power required or to be kept on hand for the pressing process, and this is accordingly cost-advantageous.
Preferably—as is already known from the state of the art—the main line is volume-regulated, so that the volume streams, precisely required for operation of the extrusion press, within the shortest possible period of time, can be made available in operationally reliable manner.
Cumulatively or alternatively to this, the control pressure system is preferably pressure-regulated or the control pressure is preferably kept above a minimum pressure, so that the required control pressure is always reliably available. The minimum pressure preferably lies at 80%, preferably minimally at 90% of the required control pressure, in order to reliably allow control in this manner. It is understood that the pressures in the overall system are limited to maximal pressures in known manner, in order to be able to prevent damage to the hydraulic system, in operationally reliable manner.
In this connection, it should be mentioned that the main cylinders, as already mentioned, side cylinders, sensor cylinders or a table slide, for example, can be provided as main consumers in the main line. Likewise, hydraulic motors, for example for spindle drives, or the like can be driven accordingly, by way of the main line.
In this connection, the different main consumers are preferably coupled with one another by way of consumer groups or consumer controllers, so that accordingly, group-based response is also possible. In this connection, it is understood that the consumer groups or controllers can be individually or jointly supplied with hydraulic oil by the corresponding main pumps, which can easily be implemented by means of accordingly switched line valves, in known manner.
Valve controls or hydraulic pumps, but also secondary consumers, which require relatively small volume streams, can easily be driven by way of the control pressure system—as is already known from the state of the art. Corresponding secondary consumers can be, for example, block or bolt loaders or block or bolt loading grippers or the like. Likewise, release pressures or the like can be applied at suitable locations by way of the control pressure system or by way of the control pressure.
Application of control pressure to the main line can particularly take place by way of proportional volume stream control. In this way, it can particularly be ensured that the control pressure does not drop suddenly, as the result of being applied to the main line and that the control pressure system remains manageable in every operating situation. Preferably, for this purpose, means for proportional volume stream control are provided between the main line and the control pressure system, in the direction of the main line, such as, for example, suitable throttles or pressure compensators.
Impermissible feedback of volume stream from the main line into the control pressure system is prevented by at least one kickback valve having an opening direction directed toward the main line.
Hydraulic oil can be stored in one or more storage devices and applied to the main line from this storage device, these storage devices or one of these storage devices by way of the control pressure. In this way, the oil volume that can be made available by way of the control pressure can be significantly increased, particularly because the storage device can be emptied into the main line even to below the control pressure, if the overall hydraulic system has been suitably designed, so that significant oil volumes can be made available to the main line by way of this storage device, which volumes can be advantageously utilized for a reduction in non-productive periods, particularly in the case of reverse strokes or similar movement sequences that take place under low pressure.
Preferably, hydraulic oil is only stored in the storage device, preferably in a separate storage device, starting from a minimum control pressure, so that maintaining the required control pressure is ensured in primary manner.
In a concrete implementation, it is accordingly advantageous if the control pressure system is connected with a storage device. In this manner, the storage device can particularly be filled with oil during those times when the control pressure pump or control pressure pumps merely serve(s) to balance out leakage oil losses or are under less stress. It is true that this oil can also be used, accordingly, as a supply for the control pressure system. Particularly, however, it is advantageous if at least parts of the oil stored in the storage device of the control pressure system are also made available to the main line, under corresponding operating conditions.
In order to guarantee the latter easily and with minimal losses, it is advantageous if at least one storage device is disposed in a connection line between the main line and the control pressure system.
The storage device, in particular, can be disposed between a pressure sequencing valve in the direction toward the pressure control system, in the connection line, on the one hand, as well as means for proportional volume stream control and/or a kickback valve in the direction toward the main line, on the other hand. By means of the pressure sequencing valve, it can be guaranteed that such a storage device is filled with oil from the pressure control system only starting from specific pressures, while oil can then be made available to the main line from the storage device, as has already been described above, whereby if applicable, not only the storage device but also the control pressure system can be secured against volume streams from the main line accordingly, by way of the kickback valve.
It is understood that the characteristics of the solutions described above and in the claims can also be combined, if applicable, in order to be able to implement the advantages cumulatively, accordingly.
Further advantages, goals, and properties of the present invention will be explained using the following description of exemplary embodiments, which are particularly shown also in the attached drawing. The drawing shows:
The hydraulic extrusion press 100 shown in
As is directly evident, the hydraulic extrusion press 100 is a relatively large system, which is operated by way of a hydraulic controller 130.
The hydraulic controller 130 can be implemented in different ways, whereby corresponding exemplary embodiments, which are, however, exemplary for only two main pumps 2, are shown in
In this connection, these exemplary embodiments have a first consumer controller 4.1, in which the two cylinders 1.1 and 1.2 for the ram are combined, as well as a second consumer controller 4.2, in which the hydromotor 1.3 as well as the sensor cylinder 1.4 are combined.
By means of the grouping into consumer controllers 4, the grouped main consumers, in each instance, can easily be synchronously supplied with hydraulic oil, accordingly. In this connection, it is understood that the main consumers 1, in each instance, can be combined into further consumer controllers 4 in any desired manner.
As is directly evident, both main pumps 2 can be optionally applied to both consumer controllers 4 by way of the line valves 3.
In a concrete implementation, the two main pumps 2 are pumps having the same construction, which is driven, in each instance, by way of a corresponding 200 kW motor, and have a conveying stream controller Q (quantity) for volume stream. In general, multiple pumps having the same construction are switched in parallel, accordingly, depending on the required overall power, whereby the number of main pumps 2 does not necessarily have to correspond to the number of consumer controllers 4. In other embodiments, the pumps and corresponding motors can be dimensioned differently, for example can be up to 1,000 kW pumps and motors or even larger, whereby in general, an optimum can be found as a function of the required power and the costs connected with this. It is understood that the number of main pumps 2, of line valves 3, and of consumer controllers 4 can be adapted to the concrete requirements, in each instance.
Hydraulic main lines 5 lead to the consumer controllers 4, in each instance, whereby it is understood that here, if applicable, multiple or further main lines 5 can also be provided.
The consumer controllers 4 empty into a container, in known manner, from which in turn the main pumps 2 are supplied in known manner, whereby here, filtering processes or the like can be provided, if applicable.
A control pressure system is also supplied from a corresponding container, preferably from the same container, by way of the control pressure pump 11, which makes control pressure available by way of control oil, for valve control or also for release processes, for example, particularly by means of great startup or tear-away pressures, as well as for secondary consumers, such as block loaders or block loading grippers, for example, which have a small volume consumption. In this connection, a 90 to 100 kW pump or a pump having a 90 to 100 kW motor is used in this exemplary embodiment, the control oil regulation p (pressure) of which takes place by way of pressure. In this manner, it can be ensured that sufficient control pressure for reliable operation of the valves is available at all points in time. It is understood that—depending on the concrete implementation—other power values for the control pressure pump 11 or further control pressure pumps can also be provided.
In the exemplary embodiment shown in
As is directly evident, it is possible, in this manner, to allow the control pressure pump 11 to convey into the hydraulic storage device 12 even during times of low conveying output, in order to make the corresponding volume available to the main consumers 1. At the given power defaults, five 200 kW motors for the main pumps 2 and an approximately 100 kW motor for the control pressure pump, approximately one-tenth more power can certainly be made available in this way, in order to have more conveying volume of hydraulic oil available, which can then be made available, in particular, for volume-intensive movements.
While the throttle 13 is configured as a manual or proportional throttle in the exemplary embodiment shown in
In this connection, it is understood that in the case of multiple main lines 5, a corresponding number of alternating valves 15 can also be provided, in order to tap the relevant load pressure for the two-way pressure compensator 14.
Likewise, depending on the concrete requirements, multiple throttles 13, pressure compensators, particularly two-way pressure compensators 14, and connection lines as well as kickback valves can be provided.
In this connection, it is understood that if applicable, other devices, for example two arrangements that correspond to the throttle 13 and the two-way pressure compensator 14 according to
The arrangement according to
In deviation from the exemplary embodiment according to
The two control pressure lines each have hydraulic storage devices 12, 22 and are each connected with the second main line 5.2, by way of proportional volume stream control, in this exemplary embodiment consisting of a throttle 13, 23, in each instance, particularly a manual or proportional throttle, and a two-way pressure compensator 14, 24, in each instance, as well as a kickback valve, in each instance, whereby it is understood that if applicable, a connection to the first main line 5.1 or a connection to the two main lines 5 can be provided, for example by way of the arrangement according to
In the case of the arrangement shown in
It is understood that the additional conveying stream made available by the control pressure pump 11 or by the control pressure can also be applied directly to a main consumer 1, as has been done as an example in the exemplary embodiment shown in
As is shown as an example using the exemplary embodiment according to
It is understood that the various embodiments explained in
In particular, parallel circuits as well as a great number of combination possibilities of the detail solutions explained in
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2012 009 182.6 | May 2012 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/DE2013/000257 | 5/10/2013 | WO | 00 |
