JP6154797B2 - Method for calibration of membrane vacuum pump and membrane vacuum pump - Google Patents

Description

  The present invention relates to a method for calibrating a membrane vacuum pump and a membrane vacuum pump.

  The membrane vacuum pump is a dry discharge pump. In practice, the connecting rod driven by the crankshaft is sandwiched between the head cover and the housing of the membrane vacuum pump, and the membrane that forms the pumping chamber (or suction chamber, “Schoepfraum” in German) by the space in the head cover. It is known to move. Membrane vacuum pumps require an inlet valve and an outlet valve to achieve directed gas delivery. As a valve, it is known from practice to use a floating valve (Flatentile in German) made of an elastomer material and pressure-controlled. The pumping chamber is hermetically sealed to the drive by the membrane so that the transported medium is not contaminated by oil and the corrosive medium does not corrode the technology. Since the dead volume between the outlet valve and the pumping chamber leads to a limited compression ratio, a final pressure of typically about 70 hectopascals can be achieved with one pump stage.

  Based on the pumping chamber without carbon, the membrane vacuum pump is particularly well suited as a dry pre-pump for a turbomolecular pump with a Holweck stage. A two-stage membrane vacuum pump that achieves a final pressure of about 5 hectopascals can already be used as a pre-pump for the Holweck turbo pump.

  A membrane pump that operates according to the vibration coil principle belongs to the prior art (Patent Document 1). In general, this pump operates in a known piston pump such that the piston is replaced by a periodically deforming membrane. In a vibration membrane pump according to the vibration coil principle, driving is performed by a piston connected to the vibration coil.

  This membrane pump belonging to the prior art has drawbacks. The membrane has the disadvantage that the dead center of the piston, i.e. the maximum stroke, has to be adjusted manually in order for the membrane to abut the membrane head optimally. When this is not optimally abutted, a dead volume is left in the transfer chamber. This leads to a limited compression ratio. On the other hand, the membrane should not be held down too much by the membrane head. This is to prevent premature wear.

  Similarly, a membrane pump belongs to the prior art (Patent Document 2). This membrane pump belonging to the prior art addresses the possibility of precise metering of the fluid to be transported. For this purpose, the piston is connected to the bottom surface of the piston working chamber, thereby defining an accurate lower dead center. This dead center does not depend on another tolerance.

  This membrane pump belonging to the prior art has drawbacks. This membrane pump must be operated with extremely high production accuracy. As the membrane wears, the dead point cannot be adjusted, so dead volume in the pumping chamber can gradually occur during operation. This cannot be compensated (or offset).

German Utility Model Publication No. 1 960 371 Specification German Patent Publication No. DE 10 2006 044 248 B3

  The technical problem underlying the invention is to provide a method of calibrating a membrane sink pump and a membrane vacuum pump that can avoid the disadvantages of the prior art.

  This technical problem is solved by a method having the features of claim 1, by a membrane vacuum pump having the features of claim 7, and by a membrane vacuum pump having the features of claim 9. .

  The method according to the invention for metering a medium and for calibrating a membrane vacuum pump for gas transport has a transport chamber that can be filled with media and can be driven linearly by a vibrating coil drive. Having a piston in the working chamber, separating the transfer chamber and the working chamber and having a membrane arranged to vibrate between the transfer chamber and the working chamber, and having a membrane head that forms the transfer chamber with the membrane In this case, the piston is formed as a piston capable of moving the membrane and moving in a predetermined stroke, but is provided with a device for detecting the position and / or dead center of the piston, And the control device stands out in that it adjusts the dead point according to the detected signal of the device.

  The method according to the invention has the advantage that the membrane vacuum pump is formed as a membrane vacuum pump that performs its own calibration. The method according to the invention is carried out by a control device. The dead center calibration is possible before each start or once after production, depending on the vibrating coil drive and controller of the membrane vacuum pump. The membrane vacuum pump, which performs its own calibration by the method according to the invention, thereby achieves an optimized final pressure. Furthermore, the manufacturing tolerances can be compensated (offset) and / or improved by the inventive method. This provides a membrane vacuum pump optimized for mechanical calibration cost savings and quick and inexpensive manufacturing.

  According to an advantageous development of the invention, the control device adjusts the dead center based on the signal of at least one knock sensor. In this embodiment, the pump controls itself with a single control circuit. When the membrane hits at least one knock sensor, the piston is instructed with the membrane to step down the stroke to a predetermined value on the next stroke and finally find the optimum dead center.

  The control device advantageously adjusts the dead center only during the calibration operation. This self-calibration (Selfstriverung in German) is performed before the start-up operation of the pump (Inbtriebahme in German). The dead center is not adjusted during pump operation.

  In accordance with an advantageous embodiment of the invention, it is intended that the piston moves the membrane into the membrane head with a reduced force relative to the pump operation at the beginning of the calibration operation or towards the mechanical final position of the membrane. Is done.

  The method according to the invention reduces the time spent on manual calibration and improves the final pressure of the membrane vacuum pump.

  Before each start of the membrane vacuum pump, a calibration operation is preferably carried out automatically.

  During this calibration operation, the movement limit of the piston in the positive direction is determined. This is done by moving the membrane into the membrane head with a reduced force relative to pumping or toward the mechanical final position of the membrane.

  Advantageously, the control device continuously detects the current position of the piston and compares it with the target position. From the current position and the target position, the control device finds the final position of the movement of the membrane.

  The benefit of this self-calibration comes from cost savings. This is achieved with lower manufacturing costs. At the same time, such pump components can have less manufacturing tolerances. This is because calibration cancels (compensates) this, leading to efficient and low cost manufacturing. The suction capacity and final pressure of the membrane vacuum pump can be changed by the method according to the invention.

  The searched final position of the membrane is advantageously saved and the final position is used as the maximum stroke during pumping.

  In accordance with an advantageous embodiment of the invention, a calibration run is performed before each start-up operation of the membrane vacuum pump or once after manufacture. This makes it possible to optimize the suction performance and final pressure of the membrane vacuum pump.

  The dead center of the piston can advantageously be adjusted so that the membrane abuts the membrane head. This ensures that no dead space occurs in the transfer chamber. This is particularly advantageous and optimizes the suction performance of the membrane vacuum pump.

  According to a further advantageous embodiment of the invention, the dead center is adjusted so that the membrane is pushed into the membrane head. This means that the membrane is moved “into the membrane head” or pressed down with a predetermined pressure. This reduces dead volume to a minimum, which also positively affects the final pressure and suction performance of the membrane vacuum pump. The pressure used here should not lead to plastic deformation or destruction of the membrane material.

  There is basically a possibility that the dead center is adjusted such that a spacing of less than 0.5 mm, particularly preferably less than 0.3 mm, is left between the membrane and the membrane head. According to this embodiment, there is indeed a small dead volume in the membrane head. However, this prevents membrane wear.

  According to a particularly preferred embodiment, the calibration is performed completely automatically. This saves significant time. This is because manual calibration is extremely time consuming.

  The calibration operation preferably includes at least one stroke of the piston. In order to achieve as good a calibration as possible, the piston usually performs several strokes during the calibration operation.

  According to another advantageous embodiment of the invention, it is intended that, in use of the knock sensor, the stroke of the piston is reduced when the control device obtains a signal from the knock sensor. When the knock sensor receives the signal, the membrane is moved toward the knock sensor. Here, the control device detects that the stroke is too large or that the dead center for optimal calibration has been exceeded. In this case, preferably the piston stroke is reduced by a predetermined value, or the stroke is reduced in steps, and the knock sensor still determines whether it provides a signal in the reduced stroke. To do this, one stroke is again performed after each step.

  The predefined value is determined beforehand. For example, the stroke can be reduced in the 1/10 millimeter range when the knock sensor emits a signal. It is also possible from the start to determine that the stroke of the piston is reduced by 0.3 millimeters or 0.5 millimeters.

  According to another advantageous embodiment of the invention, it is intended that the holding force with which the membrane is pressed against the membrane head is adjusted and that this current position of the piston is detected and stored. This holding force is necessary to hold the membrane for a short time after it has been advantageously pressed slowly into the mechanical final position, thereby allowing the final position to be detected and stored Sex occurs.

  According to another advantageous embodiment of the invention, it is intended that the maximum stroke of the piston exceeds the detected current position during the calibration operation. The possibility arises of adjusting the maximum stroke intentionally higher in the early stages of the calibration run than originally intended. In this case, the piston pushes the membrane to its final position, and so the maximum stroke is detected by the controller.

  As the membrane is moved toward the membrane head, the controller confirms this movement as an error. The piston is prevented from stopping so that the movement can continue.

  Movement errors caused by the membrane contacting the membrane head or by constantly comparing the target position of the piston with the current position are advantageously counted. When the counter reaches a defined value, the controller stops moving. This is because the final position of movement has been achieved. This is in accordance with an advantageous embodiment of the invention that the membrane is moved towards the membrane head before the start of pumping of the membrane vacuum pump, that the controller detects this movement as an error, and at least two After two error actions, it means that the controller detects and lowers the current position of the piston dead center. This measure is used to minimize membrane wear.

  Lowering the current position of the piston dead center is preferably done by a predetermined value. As already explained, the value can be predetermined, for example in tenths of a millimeter step (depending on the resolution of the built metrology system).

  The magnitude of the predetermined value is advantageously that the membrane is arranged at a distance to the membrane head at the dead center of the piston, is arranged to abut against the membrane head, or the membrane head It is arranged so that it can be pressed against.

  Depending on what operation is desired by the membrane vacuum pump, the value to be determined is determined beforehand.

  When the membrane is pressed into the membrane head, the dead volume is as small as possible.

  Membrane wear is less when the membrane is simply in contact with the membrane head, or when there is minimal clearance between the membrane and the membrane head.

  Before each start of the pump, it is possible to move the piston intentionally towards the membrane (actuator) and towards the membrane head in accordance with an advantageous embodiment of the invention. Thereby, the control device measures an operation having an error in the form of “moving error”. After a predetermined number of error operations over a predetermined time, the control device takes the current value of the incremental sensor and subtracts (subtracts) a predetermined stroke from the current value.

  The defined distance can then be given in millimeters. It is also possible to use other count units, for example “counts” (in English) that are proportional to the unit of length.

  The determined distance, or the confirmed amount of “count”, depends in particular on manufacturing tolerances.

  According to another advantageous embodiment of the invention, the piston dead center overshoot caused by high frequency operation is intended to be taken into account when adjusting the piston dead center.

  In high frequency operation, a so-called “overshot (over-shot in English)”, that is, an overshoot of the final position to be originally traveled. This takes into account the process or “count” to be subtracted in the calculation of the dead center and accordingly. The control device stores the maximum value found in this way as a dead point for continuous operation.

  According to another advantageous embodiment of the invention, the lower movement limit of the piston is sought and stored. The lower travel limit, that is, when the piston moves away from the membrane head, is advantageously calculated and stored as an upper chord. In order to achieve a symmetric movement sequence of the membrane as much as possible, during the calculation, the membrane is sought to return the same process as positive as possible in the negative direction.

  According to an advantageous embodiment of the invention, the minimization of the differential pressure contributing to the miniaturization of the actuator unit consisting of the vibration coil drive, the piston and the membrane is achieved by sealing the working chamber against the ambient pressure. When the differential pressure is lowered by an independent pump-out in the space behind the membrane, a smaller oscillating coil drive or a lower flow strength can be used.

  Particularly well, the differential pressure minimization is achieved in a two-head membrane pump in which the forces of both heads are offset.

  At least one spring can be integrated in the membrane head or in the linear drive for further optimization or for force reduction. This supports the actuator during the return movement of the membrane.

  A membrane vacuum pump according to the invention for transporting a gas, having a transport chamber that can be filled with gas, and having a piston that can be linearly driven by a vibration coil drive unit in the working chamber, the transport chamber and the working chamber And a membrane head arranged to vibrate between the transfer chamber and the working chamber, with a membrane head forming the transfer chamber together with the membrane, wherein the piston is a piston that allows movement of the membrane The vacuum pump formed as a piston capable of moving a predetermined stroke sentence is provided with a device for detecting the position and / or dead center of the piston and a control device. This control device is characterized in that it is formed as a control device that can be adjusted according to the signal of the device that detected the dead point.

  The membrane vacuum pump according to the invention has the advantage that it can be implemented as claimed in claims 1 to 16 by its self-calibration method.

  The membrane vacuum pump achieves an optimum final pressure and an optimum compression ratio, since the optimum dead center can be detected and adjusted via self-calibration by the inventive membrane vacuum pump.

  In accordance with a particularly advantageous embodiment of the invention, at least one knock sensor is provided. A control device provided in the membrane vacuum pump advantageously adjusts the dead center of the piston based on the signal of the knock sensor. This means that when the membrane moves toward the knock sensor, the knock sensor outputs a signal. In this case, the pressure point (or pressure application point) is not accurately adjusted and the maximum stroke of the piston is reduced. The reduction is done step by step for a predetermined path length or “count”. It is also possible to provide a predetermined value (a value by which the maximum stroke is reduced by this value).

  According to an advantageous embodiment of the invention, the control device is designed as a control device that adjusts the dead center of the piston only during the calibration operation.

  During a calibration operation, which can consist of at least one stroke of the piston, preferably a plurality of strokes, the pressure point of the piston can be adjusted by the controller. Once the dead center is optimally adjusted, it is saved and no longer changed during pump operation, ie during pump operation.

  Only after a new calibration operation is carried out, for example after the pump has been stopped, the dead center is again adjusted on demand by the control device.

  According to another advantageous embodiment of the invention, the device for detecting the position and / or dead center of the piston is designed as a Hall sensor.

  Advantageously, the device for detecting the position and / or dead center of the piston is designed as an incremental Hall sensor.

  The hall sensor is extremely suitable as a stroke sensor for detecting the position of the piston.

  The membrane vacuum pump can be formed as a one-head, two-head, or multi-head membrane vacuum pump.

  For example, there is a possibility of providing a two-head type membrane vacuum pump. The piston then moves the membrane on each side as seen in the axial direction.

  There is also the possibility of providing two membrane heads on one side and one membrane head on the other side of the piston.

  According to an advantageous embodiment of the invention, the working chamber is formed sealed against ambient pressure. Minimizing the differential pressure that contributes to the miniaturization of the actuator unit is achieved by sealing the working chamber against ambient pressure.

  Advantageously, the working chamber is formed as a pumped-out working chamber. If the differential pressure is lowered by an independent pump-out in the space behind the membrane, a smaller oscillating coil drive or a lower flow strength can be used.

  According to another advantageous embodiment of the membrane vacuum pump, at least one spring is provided in the membrane head and / or in the linear drive for the return movement of the piston and the membrane. With the spring, force reduction and optimization are achieved. The actuator is supported by a spring during the return movement of the membrane.

  According to another advantageous embodiment of the invention, the membrane vacuum pump has at least one inlet valve and at least one outlet valve. These are connected to the transfer chamber. These valves are preferably formed as a reed valve reed valve (in German), and / or as a ball valve and / or as a disc valve. Other types of valves are possible as well.

  According to another advantageous embodiment of the invention, a single membrane vacuum pump is provided. At that time, the vibration coil driving unit has at least one coil and at least one magnet attached to the coil. Here, the coil is formed as a stator and the magnet is formed as an armature. Here, the coil of the drive unit changes from the position of the armature to the position of the stator. At the same time, the magnet stator becomes a new armature for the drive. A special advantage of this embodiment is that the heat mainly emitted by the coil can obviously be released well. For this purpose, it is intended according to another advantageous embodiment of the invention that the stator is connected in temperature communication with the housing and that cooling ribs are arranged on the housing. This allows the system temperature to be released very well. In order to keep the temperature of the system at a constant level, for example, it may be intended to be intended to flow well against the housing.

  The armature can advantageously be mounted on at least two sliding bearings or on at least two ball sleeves (Kugelhuelsen in German).

  This makes it possible to efficiently reduce the gap between the coil and the magnet, thereby improving the efficiency of the drive unit.

  A membrane vacuum pump according to the invention for transporting a gas, having a transport chamber that can be filled with gas, and having a piston that can be linearly driven by a vibration coil drive unit in the working chamber, the transport chamber and the working chamber And a membrane head arranged to vibrate between the transfer chamber and the working chamber, and having a membrane head forming a transfer chamber with the membrane, wherein the piston is a piston for moving the membrane, The membrane vacuum pump is formed as a piston that can move in a predetermined stroke, in which the vibration coil drive unit has at least one coil and at least one magnet attached to the coil. It is formed and is characterized in that the magnet is formed as an armature.

  In a vibration coil drive unit known from practice, the coil is formed as an armature and the magnet as a stator. In this vibration coil drive unit, an extremely high temperature is generated in the vibration coil drive unit. This is because the coil is poorly cooled as an armature.

  According to the invention, the coil of the drive unit is changed from the position of the armature to the position of the stator. At the same time, the magnet stator becomes a new armature for the drive. A particular advantage of the present invention resides in the fact that the heat generated by the coil can obviously be released better. The coil is connected in heat transfer with the housing in accordance with an advantageous embodiment of the invention. The housing is then preferably provided with cooling ribs. This allows the temperature of the system to be released very well. In order to keep the temperature of the system at a constant level, it may be intended, for example, to insulate the housing with good flow.

  The armature can advantageously be mounted on at least two sliding bearings or on at least two ball sleeves (Kugelhuelsen in German).

  This makes it possible to efficiently reduce the gap between the coil and the magnet, thereby improving the efficiency of the drive unit.

  According to a particularly advantageous embodiment of a membrane vacuum pump with a coil as stator and a permanent magnet as armature, a device and a control device are provided for detecting the position and / or dead center of the piston. This control device is formed as a control device that can adjust the dead point according to a signal detected by the device.

  The membrane vacuum pump according to the invention has the advantage that it can be implemented as claimed in claims 1 to 16 by its self-calibration method.

  With the membrane vacuum pump according to the invention, the optimum dead center can be detected and adjusted by self-calibration, so that the membrane vacuum pump achieves the optimum final pressure, while at the same time effective cooling of the coil. Is possible.

  According to a particularly advantageous embodiment of the invention, at least one knock sensor is provided and the control device is formed as a control device for adjusting the dead center based on the signal of the knock sensor. This means that when the membrane moves relative to the knock sensor, the knock sensor outputs a signal. In this case, the pressure point is not accurately adjusted and the maximum stroke of the piston is reduced. The decrease is performed step by step by a predetermined path length or count. It is also possible to provide a predetermined value by which the maximum stroke is reduced.

  According to another advantageous embodiment of the invention, the control device is designed as a control device that adjusts the dead center of the piston only during the calibration operation.

  During a calibration operation which can consist of at least one stroke of the piston, preferably a plurality of strokes, the pressure point of the piston can be adjusted by the control device. Once the dead center is optimally adjusted, it is saved and no longer changes during pump operation, i.e. during pump operation.

  For example, after a new calibration operation is performed after the pump life (Standzeit in German), the dead center is again adjusted as required by the controller.

  According to another advantageous embodiment of the invention, the device for detecting the position or dead center of the piston is formed as a Hall sensor. The device for detecting the position or dead center of the piston is preferably designed as an incremental Hall sensor.

  The hall sensor is extremely suitable as a stroke sensor for detecting the position of the piston.

  The membrane vacuum pump can be formed as a one-head, two-head, or multi-head membrane vacuum pump.

  For example, there is a possibility of providing a two-head type membrane vacuum pump. The piston then moves the membrane on each side as seen in the axial direction.

  There is also the possibility of providing two membrane heads on one side and one membrane head on the other side of the piston.

  According to an advantageous embodiment of the invention, the working chamber is formed sealed against ambient pressure. Minimizing the differential pressure that contributes to the miniaturization of the actuator unit is achieved by sealing the working chamber against ambient pressure. According to another advantageous embodiment of the invention, the working chamber is formed as a pumped-out working chamber. If the differential pressure is lowered by an independent pump-out in the space behind the membrane, a smaller oscillating coil drive or a lower flow strength can be used.

  According to another advantageous embodiment of the membrane vacuum pump, at least one spring is provided in the membrane head and / or in the linear drive for the return movement of the piston and the membrane. With the spring, force reduction and optimization are achieved. The actuator is supported by a spring during the return movement of the membrane.

  According to another advantageous embodiment of the invention, the membrane vacuum pump has at least one inlet valve and at least one outlet valve. These are connected to the transfer chamber. The valve is preferably connected to the transfer chamber. These valves are preferably formed as reed valves and / or ball valves and / or disc valves. Other types of valves are possible as well.

  The method according to the invention can be replaced by all the features in the membrane vacuum pump described in this application. The membrane vacuum pump described can be combined in a manner similar to the features published in that application.

  The membrane vacuum pump can advantageously be formed as a two-head membrane vacuum pump with a vibrating coil drive.

  A two-head membrane vacuum pump means that one membrane on both sides of the piston is driven by a reciprocating piston.

  Here, energy regeneration can be intended by springs on both sides of the piston. It is also possible to provide a condenser (Kondensatoren in German) instead of the spring.

  In this case, it is not necessary to minimize the differential pressure. This is because there are two membranes in one axis. This cancels the force generated by the differential pressure.

  With the membrane vacuum pump according to the invention, a lower final pressure is achieved. This is because the dead volume is smaller than that of the prior art.

  Connecting at least one coil of the vibration coil drive unit directly to the housing or connecting a coil pair of the vibration coil drive unit enables efficient cooling. This is due to, for example, spraying on the housing ribs (Gehaeuseverrippun in German) (Anblasen in German).

The membrane pump according to the invention having the vibration coil drive unit has the following advantages.
1. The tilting or wobbling motion of the membrane of the conventional prior art membrane pump having a crankshaft is prevented by purely linear motion.
This eliminates abrasion of the membrane in the membrane head due to rubbing or friction in the membrane head.
2. The membrane pump according to the invention has a membrane head that is optimally adapted for pure linear motion of the membrane. This effectively reduces the dead volume.
3. The miniaturization or reduction of the valve channel reduces the dead volume and thereby improves the final pressure or compression ratio.

  Another feature of the invention arises on the basis of the attached drawings. In the drawings, several embodiments of membrane vacuum pumps according to the invention are shown by way of example only. The figure shows the following:

The figure of the longitudinal direction cross section of a two-head type membrane vacuum pump. The perspective view of the longitudinal cross section of the membrane vacuum pump of FIG. FIG. 2 is a side view of the membrane vacuum pump of FIG. The perspective view of a membrane vacuum pump. The figure of the longitudinal direction cross section of a 3 head type membrane vacuum pump. Sectional view of the membrane vacuum pump during the four phases of function.

  FIG. 1 shows a membrane vacuum pump 1 having two membranes 3, 4 that are frictionally connected to a piston 2. The membranes 3 and 4 are each provided with one membrane head 5 and 6. When the piston 2 moves maximum, the membranes 3 and 4 travel with respect to the membrane head.

  In order to generate a continuous vibration or oscillating movement of the piston 2, the coil 7, i.e. the conductor conducting the current, is moved in the magnetic field of a permanent magnet 8 which always has alternating current directions. There is an air gap between the coil 7 and the permanent magnet 8. This should be as small as possible to increase the efficiency of the actuator consisting of the piston 2 and the membranes 3 and 4.

  The piston 2 is non-magnetic and is supported on the sliding bearing 9. A bearing part without a sliding bearing part is also possible. This is an optimized positive (stabilized) radial strength of the membrane arrangement (perpendicular to the stroke direction) and negative (non-stabilized) coil arrangement (perpendicular to the stroke direction). ) Radial strength.

  An incremental Hall sensor 10 is present for detecting the path of the piston 2 region so that the position of the piston 2 can be permanently confirmed. Incremental Hall sensors are represented only briefly in FIG. The hall sensor 10 is used for current diversion. This is done by turning the current direction early according to the position of the piston 2. A spring 11 is provided for energy recovery. The spring 11 is disposed on both sides of the piston 2. It is also possible to provide a condenser (not shown) for energy recovery.

  Since the membranes 3 and 4 are sandwiched between the housing 12 and the membrane heads 5 and 6, the transfer chambers 13 and 14 are airtightly separated from the working chamber 15.

  In contrast to the conventional vibration coil drive unit (Swingingspulnetrieb in German), the drive unit shown in FIG. 1 has a coil 7 formed as a stator. The permanent magnet 8 is formed as an armature (Laeufer in German). As a result, a very good heat dissipation from the coil 7 is possible by direct contact with the housing 12. The housing 12 has cooling ribs 16 particularly in the area of the coil 7. The cooling rib is flowed through, for example, indoor air having a temperature lower than the housing temperature. As a result, the coil 7 can be maintained at a constant temperature.

  The coil 7 represented in FIG. 1 preferably consists of a plurality of coil pairs. These coil pairs can be fed variously so that the permanent magnet armature can be moved.

  FIG. 2 shows the vacuum pump 1 in the form of a cut diagram. The same members are given the same reference numerals. To avoid repetition, reference is made to the illustration of FIG.

  In FIG. 2, the cooling ribs 16 can be seen. This is used for cooling the coil 7.

  FIG. 3 shows a side view of a vacuum pump having cooling ribs 16.

  FIG. 4 shows a perspective view of the membrane pump 1. Similarly, the cooling ribs 16 are clearly visible.

  The vacuum pump 1 shown in FIG. 1 has a hall sensor 10. This Hall sensor is used to detect the position of the piston 2. It simply has a control device 17 represented only in a simplified manner. The control device 17 detects the dead center of the piston according to the position of the piston 2. Before the pump start-up operation, i.e. before the pumping process, a calibration run is performed. Here, the piston 2 moves the membrane 3 into the membrane head 5 with a reduced force with respect to the pump operation or moves towards the mechanical final position of the membrane 3. Here, the control device 17 continuously detects the current position of the piston 2 and compares it with the target position. By comparing the current position with the target position, the control device finds the final position of the movement of the membrane. This final position is continuously used as the maximum stroke during the pump operation of the membrane vacuum pump.

  The dead center of the piston 2 can be adjusted so that the membrane 3 is arranged in contact with the membrane head 5. The dead center can also be adjusted so that there is less than 0.3 mm between the membrane and the membrane head. The dead point can be adjusted so that the membrane 3 is pressed against the membrane head 5 with a predetermined force.

  Advantageously, the dead center is adjusted in such a way that the pump performance of the pump is optimized since the membrane 3 comes into full contact with the membrane head 5 and thus the transfer chamber 13 does not have a dead volume. Is also possible.

  According to the two-head membrane pump represented in FIG. 1, the calibration described is carried out correspondingly for the membrane 4 and the membrane head 6.

  The working chamber 15 is sealed against atmospheric pressure. Advantageously, the working chamber 15 is additionally pumped out (in other words ausgepump). The membrane vacuum pump 1 has an inlet valve and an outlet valve for each of the transfer chambers 13 and 14 in accordance with FIG.

  FIG. 5 shows a modified embodiment of the membrane vacuum pump 20. The membrane vacuum pump 20 has a housing 21. A piston is linearly supported in the housing.

  The linear drive consists of a coil and a magnet, which is not represented in FIG. 5, but is performed according to the principle of FIG.

  According to FIG. 5, the vacuum pump has three membrane heads 22, 23, 24. The membrane heads 22, 23, 24 are provided with membranes 25, 26, 27. The movement of the membrane 27 by the piston 22 is performed directly by the rod 28. The movement of the membranes 25 and 26 by the piston 22 is performed by a T piece 29. The membrane heads 22 and 23 can be connected in parallel or directly.

  In FIG. 5, only the membrane heads 22, 23, and 24 are simply shown. Inlets and outlets are not shown.

  FIG. 6 shows the functional principle of a membrane vacuum pump according to the prior art for completeness.

  FIG. 6 shows a membrane vacuum pump 1 having a housing 12 with a membrane 30. The membrane is sandwiched on the edge side in the housing, and can be moved down while being wobbled by the connecting rod 31 of the motor drive unit.

  Within the housing 12 is a scoop frame 13 bounded by the membrane 3 of the housing head 32. This pumping chamber 13 is bounded by the membrane 3 of the housing head 5 of the housing 12.

  In the housing head 5, there is at least one suction pipe 18 that is led into the transfer chamber 13. It has an inlet valve device 33 and a discharge pipe 19 led from the pumping chamber and having an outlet valve device 34.

  Generally, the inlet valve device 33 includes an inlet valve opening 35 and an inlet valve body 36 that closes the inlet valve opening when the pumping chamber 13 is overpressured. In a suitable manner, the outlet valve device 34 has an outlet valve body 37 that closes when the pumping chamber 13 is under negative pressure.

  During the descending operation of the membrane 3, a negative pressure is generated in the transfer chamber. As a result, a differential pressure is applied to the inlet valve body 36. This differential pressure presses the valve body 36 toward the transfer chamber 13. Gas flows from the suction pipe 18 into the pumping chamber 13 through the opened inlet valve. During the upward movement of the membrane 3, excessive pressure is generated in the transfer chamber 13. As a result, a differential pressure is applied to the inlet valve body 36. This differential pressure presses the valve body 36 toward the valve opening 35. During the descending operation of the membrane 3, a negative pressure is generated in the transfer chamber 13. As a result, a differential pressure is applied to the outlet valve body 38. This differential pressure presses the valve body 38 toward the transfer chamber 13 and toward the valve opening 39. During the upward movement of the membrane 3, excessive pressure is generated in the transfer chamber 13. As a result, a differential pressure is generated in the outlet valve body 38. This differential pressure presses the valve body 38 toward the housing cover 40. This means that the gas flows from the pipe 18 into the transfer chamber 13 because the inlet valve device 33 is opened during the downward movement of the connecting rod 31. When the connecting rod 31 moves up, the inlet valve device 33 is closed and the outlet valve device 34 is opened, so that the gas existing in the transfer chamber 13 flows into the pipe 19.

DESCRIPTION OF SYMBOLS 1 Membrane vacuum pump 2 Piston 3 Membrane 4 Membrane 5 Membrane head 6 Coil 7 Coil 8 Magnet 9 Sliding support 10 Hall sensor 11 Spring 12 Housing 13 Transfer chamber 14 Transfer chamber 15 Actuation chamber 16 Cooling rib 17 Control device 18 Inlet 19 Outlet 20 Membrane pump 21 Housing 22 Membrane head 23 Membrane head 24 Membrane head 25 Membrane 26 Membrane 27 Membrane 28 Rod 29 T-piece 30 Membrane 31 Connecting rod 32 Housing head 33 Inlet valve device 34 Outlet valve device 35 Inlet valve opening 36 Valve body 37 Valve Body 38 Valve body 39 Outlet valve opening 40 Housing cover

Claims (21)

A method for calibrating a membrane vacuum pump for transporting media, comprising:
Has a transfer chamber that can be filled with medium, has a piston in the working chamber that can be driven linearly by the vibration coil drive unit, separates the transfer chamber from the working chamber, and vibrates between the transfer chamber and the working chamber A membrane head arranged to form a transfer chamber together with the membrane, wherein the piston is formed as a piston capable of moving the membrane and moving a predetermined stroke In
The device (10) for detecting the position of the piston (2) and / or the dead point is provided, and the control device (17) determines the dead point according to the detected signal of the device (10). Adjusting,
Before the start of the pump operation of the membrane vacuum pump (1), the membrane (3, 4) is moved relative to a membrane head (5,6), and a control unit (17) comprises a error this movement It is detected, and after at least two of the error operation, a method of the control device (17) detects the current position of the dead center of the piston (2), and wherein the lower it.   The control device (17) adjusts the dead center based on the signal of at least one knock sensor and / or the control device (17) adjusts the dead center of the piston (2) only during the calibration operation. The method of claim 1, wherein:   The control device (17) continuously detects the current position of the piston (2) and compares it with the target position, and the control device (17) determines the membrane (3, 4) from the current position and the target position. 3. A method according to claim 1 or 2, characterized in that the final position of the movement is searched.   4. Method according to claim 3, characterized in that the final position of the sought membrane (3, 4) is saved and the final position is used as the maximum stroke during pumping.   5. The dead point according to claim 1, wherein the dead point is adjusted such that a space of less than 0.5 mm remains between the membrane (3, 4) and the membrane head (5, 6). The method according to one item.   6. A method according to any one of the preceding claims, characterized in that the dead point is adjusted so that the membrane (3, 4) abuts the membrane head (5, 6).   7. A method according to any one of the preceding claims, characterized in that the membrane (3, 4) is adjusted to be pressed into the membrane head (5, 6).   8. A method according to any one of claims 1 to 7, characterized in that the calibration is carried out fully automatically and the calibration operation comprises at least one stroke of the piston (2).   9. Method according to claim 8, characterized in that, when using the knock sensor, the stroke of the piston (2) is reduced when the control device (17) obtains a signal of the knock sensor. The descent of the current position of the dead center of the piston (2) is performed by a predetermined value, and the magnitude of the predetermined value is
The membrane (3, 4) is arranged at the dead center of the piston (2) to be spaced from the membrane head (5, 6), or abutted against the membrane head (5, 6), or 10. A method according to any one of the preceding claims, characterized in that it is arranged to be pressed against the membrane head (5, 6). A membrane vacuum pump for gas metering and transfer, having a transfer chamber that can be filled with gas, and having a piston that can be linearly driven by a vibration coil drive unit, It has a membrane that separates the working chamber and is arranged to vibrate between the transfer chamber and the working chamber, and has a membrane head that forms the transfer chamber together with the membrane, with the piston being able to move the membrane And in a membrane vacuum pump formed as a piston capable of moving a predetermined stroke,
A device for detecting the position and / or dead point of the piston is provided, and a control device (17) is provided, which controls the dead point of the device (10). Formed as a control device (17) adjustable according to the detected signal,
Before the start of the pump operation of the membrane vacuum pump (1), the membrane (3, 4) is moved relative to a membrane head (5,6), and a control unit (17) comprises a error this movement It is detected, and after at least two of the error operation, the control unit (17) detects the current position of the dead center of the piston (2), and membrane wherein the vacuum pump to reduce this.   12. The membrane vacuum pump according to claim 11, wherein the vibrating coil drive unit has at least one coil and at least one magnet attached to the coil, wherein the coil (7) is a stator. A membrane vacuum pump characterized in that the magnet (8) is formed as an armature. It is a membrane vacuum pump for gas transfer, has a transfer chamber that can be filled with gas, has a piston that can be linearly driven by the vibration coil drive unit, and separates the transfer chamber and the operation chamber And a membrane head arranged to vibrate between the transfer chamber and the working chamber, and having a membrane head that forms the transfer chamber together with the membrane, wherein the piston is capable of moving the membrane and has a predetermined In the membrane vacuum pump, which is formed as a piston capable of moving the stroke, the vibration coil drive unit has at least one coil and at least one magnet attached to the coil.
The coil (7) is formed as a stator and the magnet (8) as an armature,
Before the start of the pump operation of the membrane vacuum pump (1), the membrane (3, 4) is moved relative to a membrane head (5,6), and a control unit (17) comprises a error this movement It is detected, and after at least two of the error operation, the control unit (17) detects the current position of the dead center of the piston (2), and membrane wherein the vacuum pump to reduce this.   14. A membrane vacuum pump according to claim 12 or 13, characterized in that the stator is connected in temperature communication with the housing (12) and the housing (12) is provided with cooling ribs (16).   A device (10) for detecting the position and / or dead center of the piston (2) is provided, and a control device (17) is provided, and this control device (17) is provided with the device (10 The membrane vacuum pump according to any one of claims 11 to 14, wherein the membrane vacuum pump is formed as a control device (17) capable of adjusting a dead point in accordance with a detected signal.   At least one knock sensor is provided and the control device (17) is formed as a control device (17) for adjusting the dead point based on the signal of the knock sensor and / or the control device; (17) is formed as a control device (2) for adjusting the dead point of the piston (2) only during the calibration operation and / or for detecting the position and / or dead point of the piston (2) A membrane vacuum pump according to any one of claims 11 to 15, characterized in that the device (10) is formed as a Hall sensor.   17. The membrane vacuum pump (1, 21) is formed as a one-head, two-head, or multi-head membrane vacuum pump (1, 21). The membrane vacuum pump according to item.   18. A membrane vacuum pump according to claim 17, characterized in that the working chamber (15) is formed sealed against atmospheric pressure.   19. A membrane vacuum pump according to any one of claims 11 to 18, characterized in that the working chamber (15) is formed as a pumped-out working chamber (15).   In order to return the piston (2) and the membrane (3, 4), at least one spring (11) is provided in the membrane head (5, 6) and / or in the linear drive. The membrane vacuum pump according to any one of claims 11 to 19.   The membrane vacuum pump (1, 21) has at least one inlet valve (18) and at least one outlet valve (19), and the valve (18, 19) is a reed valve and / or ball valve and / or disc valve. The membrane vacuum pump according to any one of claims 11 to 20, wherein the membrane vacuum pump is formed as follows.

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