Pinch valve system

Abstract

To further improve conventional pinch valve systems for clamping a tube in a fluid system.SOLUTION: A pinch valve system includes: a closing element 2 that is movable in an axial direction A and includes a closing piece 21 for clamping a tube 100; a permanent magnetic holding device 5 capable of holding the closing element 2 by permanent magnetic force at an open position and a closed position, without requiring supply of energy for holding; and an electromagnetic actuating device 6 to carry out a switching process for moving the closing element 2 between the open position and the closed position. Electrical energy which is sufficient to carry out at least the switching process can be stored in an energy storage device 7. A rest position, which is the open position or the closed position, can be predetermined for a control unit 8. The control unit 8 can trigger the switching process with which the closing element 2 is brought to the rest position by the energy stored in the energy storage device 7.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a pinch valve system for clamping a tube in a fluid system, which pertains to the preamble of the independent claim.

Background Art

[0002] For example, a fluid system for biological liquids generally has a pump device for transporting the fluid, and the pump device is connected via a tube to a circuit or other components of the fluid system, such as an accumulation tank or a filter device. An example of such a fluid system is a plant in the biotechnology or pharmaceutical industry that has a bioreactor in which proteins or other biological substances are produced in a cell culture medium and removed from the process. Another example is a heart-lung machine that is connected to a patient's blood circulation during heart surgery to take over the function of the heart and maintain blood circulation. If possible, it is very important to ensure that there are no air bubbles in the blood delivered to the patient's circulation, because these pose a serious danger to the patient. Therefore, usually, a heart-lung machine is provided with an air bubble detector and a pinch valve system downstream of the pump. As soon as the air bubble detector detects an air bubble, the pinch valve system must clamp as quickly as possible the tube through which the blood is being transported into the patient's body, thereby interrupting the blood supply to the patient so that the air bubbles cannot enter the body's circulatory system.

[0003] However, in other fluid systems, it is often necessary to be able to clamp the tube as quickly and reliably as possible to prevent further flow through the tube. Therefore, the pinch valve system used for this purpose functions as an on / off switch for the flow connection between the components of the fluid system.

[0004] Many forms of pinch valve systems for clamping tubes are known. A particularly efficient and reliable pinch valve system is disclosed in European Patent Application No. 1132108. This pinch valve system comprises a movably positioned closure element with a closing piece for clamping a tube; a permanent magnetic retaining device, which is designed to hold the closure element in two different stable equilibrium positions, namely an open position and a closed position, without requiring the permanent magnetic retaining device to be energized to hold each equilibrium position; and an actuation means for moving the closure element from the open position to the closed position.

[0005] The permanent magnetic holding device is designed so that there are two stable equilibrium positions with respect to the closing element: on the one hand, an open position where the tube inserted into the pinch valve system is not clamped or is only slightly clamped, allowing liquid to flow through the tube; and on the other hand, a closed position where the tube is clamped by the closing piece of the closing element so that liquid can no longer flow through the tube. No electrical energy is required to hold the closing element in the two equilibrium positions. The closing element is held passively, that is, permanently, magnetically in the two equilibrium positions, which is a significant advantage in terms of energy consumption. This means that the closing element is a bistable device that requires energy only to switch from one equilibrium position to the other and does not require energy to hold each stable equilibrium position.

[0006] Furthermore, no spindle drive or other self-locking drive is required to operate the pinch valve system, which is why the pinch valve system is structurally simple and very compact.

[0007] The actuation mechanism includes a coil positioned to exert an electromagnetic force on the closing element acting in either the closed or open position. By acting the coil, an electromagnetic force is generated in addition to the permanent magnetic coercive force, and this force deflects the closing element away from its other stable equilibrium position so that it assumes the other stable equilibrium position. Therefore, the coil needs to be actuated only when the closing element is to be moved from the open position to the closed position, or vice versa.

[0008] Although the pinch valve system disclosed in European Patent Application No. 1132108 has proven to be very good in practice, there is room for improvement. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] European Patent Application No. 1132108 [Overview of the project] [Problems that the invention aims to solve]

[0010] Therefore, starting from this latest technology, the object of the present invention is to further improve the aforementioned type of pinch valve system, particularly to achieve higher operational safety and greater flexibility. [Means for solving the problem]

[0011] The subject matter of an invention that satisfies this purpose is characterized by the structure of an independent patent claim.

[0012] Accordingly, the present invention proposes a pinch valve system for clamping a tube in a fluid system, comprising: a closing element having a closing piece that is axially movable and clamps a tube; a permanent magnetic holding device designed to hold the closing element by permanent magnetic force in two different stable equilibrium positions, namely an open position and a closed position, without requiring the permanent magnetic holding device to supply energy to hold the respective equilibrium positions; and an electromagnetically actuated device for performing a switching process to move the closing element from an open position to a closed position or from a closed position to an open position. An energy storage device and a control unit are provided, and the energy storage device can store at least enough electrical energy to perform the switching process, and a resting position which is the open position or the closed position can be predetermined with respect to the control unit, and the control unit can trigger (induce) a switching process which can bring the closing element to the resting position by the energy stored in the energy storage device.

[0013] Therefore, in the case of the pinch valve system according to the present invention, even if the external energy supply source completely fails, for example in the case of a main line interruption, the closing element of the pinch valve system can be brought to a predetermined resting position. In any case, since the energy storage device of the pinch valve system stores a very large amount of energy, at least one switching process is still possible even if the external energy supply source fails. Therefore, in any case, it is possible to bring the closing element to a desired resting position even without an external energy supply source. This means that operational reliability is greatly improved.

[0014] Furthermore, the pinch valve system according to the present invention is characterized by a high degree of flexibility because the predetermined resting position can be either an open or closed position. Depending on the specific application, it may be desirable, or even necessary, for the closing element to be brought to the open position in the event of a failure of the external energy source so that fluid can flow through the tube. In other applications, it may be desirable, or even necessary, for the closing element to be brought to the closed position in the event of a failure of the external energy source so that the tube is clamped and further flow of fluid through the tube is reliably prevented. The selection of whether the resting position is an open or closed position can be performed, for example, electronically, electromechanically, or by software.

[0015] In a particularly preferred embodiment, the closing element, retaining device, operating device, energy storage device, and control unit (8) are arranged within a common housing, the housing having a connection for connecting to an external energy source. This embodiment is very compact and particularly easy to handle. The connection for connecting to an external energy source may further be used for a control line or signal line that can control or program the pinch valve system.

[0016] Preferably, a monitoring sensor capable of detecting the interruption of energy supply from an external energy source is provided within the common housing. Thus, the monitoring sensor incorporated into the housing can detect when the energy supply from the external energy source becomes completely non-functional or insufficient. For example, the monitoring sensor can detect the interruption of supply voltage or main current supplied by the external energy source. As soon as the interruption of supply voltage or current is detected, this information is passed to the control unit. The control unit checks whether the closing element is in the open or closed position and which is a predetermined resting position for the closing element. If the closing element is not in the desired resting position, the control unit triggers a switching process to bring the closing element to the resting position. In any case, even if the external energy source can no longer supply energy, sufficient energy is stored in the energy storage device to perform at least one switching process.

[0017] In a preferred embodiment, the permanent magnetic retaining device has a permanent magnetic ring surrounding the closing element. This permanent magnetic ring allows the closing element to be held in one of two stable equilibrium positions by permanent magnetic force without the need to supply energy to the pinch valve system, for example, in the form of an electric current. Preferably, the retaining device is also designed without a spring to hold the closing element in a stable equilibrium position.

[0018] According to a preferred embodiment, the energy storage device is designed as an intermediate circuit for supplying energy to the actuator. The energy storage device may have at least one capacitor, the capacitance of which is large enough to supply electrical energy to the actuator for at least one switching process in the event of failure of the external energy source. Due to this large energy storage device, the energy source supplying electrical energy to the intermediate circuit can also be advantageously made smaller in size.

[0019] Furthermore, it is preferable that a position sensor is provided to determine the position of the closing element.

[0020] Providing a measurement sensor for determining the electrical energy stored in the energy storage device is a further advantageous measure.

[0021] Also, it is preferable that a current sensor is provided to determine the switching current, and the switching current is the current required for the switching process.

[0022] For example, the switching current can be the closing current, and the closing current is the current required for the switching process from the open position to the closed position. For example, the switching current can be the opening current, and the opening current is the current required for the switching process from the closed position to the open position.

[0023] The current supplied to the operating device can be determined by the current sensor over the complete switching process, i.e., over the entire stroke movement of the closing element from the open position to the closed position or vice versa. This information can be used, for example, to determine whether a tube is inserted into the pinch valve system.

[0024] In the case of this embodiment, it can be particularly assumed that tube detection can be carried out based on the switching current. For this purpose, for example, a correlation relationship can be stored in the control unit in the form of a look-up table regarding which current is required for any tube type for carrying out the switching process from the open position to the closed position and / or from the closed position to the open position. For example, the tube type can include information regarding the respective material of the tube, the diameter of the tube, the wall thickness of the tube, and, if necessary, other parameters. Based on the switching current determined by measurement and, if necessary, the signal from the position sensor, the tube inserted into the pinch valve system can be identified.

[0025] According to a preferred embodiment, two side openings for receiving the tube are provided in the housing, and a closing cover is provided which is connected to the housing by an articulated joint (articulated coupling), and the closing cover can be moved back and forth (i.e., reciprocally) between a first position and a second position, in the first position, the tube can be inserted into the side opening, and in the second position, the tube is fixed relative to the housing of the pinch valve system.

[0026] Preferably, a tube pinch element for cooperating with the closing part piece of the closing element is arranged in the closing cover, so that the tube can be clamped between the closing part piece and the tube pinch element when the closing cover is in the second position.

[0027] Furthermore, it is a preferred measure that the tube pinch element is designed and arranged to be replaceable, whereby the pinch valve system can be easily adapted to different types of tubes, especially tubes with different outer diameters and / or inner diameters.

[0028] A preferred embodiment is that a recess into which the tube pinch element can be inserted is provided in the closing cover. As a result, the tube pinch element can be replaced particularly simply and quickly, especially without using tools.

[0029] Furthermore, an axially movable protection element is provided, and it is preferable that the protection element is loaded (loaded) by a spring so that the protection element covers the two side openings when the closing cover is in the first position or the second position and the tube is not inserted into the pinch valve system. This protection element functions especially as finger protection for the operator, so that, for example, when the tube is not inserted into the pinch valve system or when inserting the tube, the hand is not inadvertently extended into the side opening. When inserting the tube, the protection element is axially moved by the tube against the spring force until the tube is located in the two side openings. Thereafter, the closing cover is brought to the second position so that the tube is fixed between the tube pinch element and the closing part piece.

[0030] A further advantage is that a fixing element can be provided in the housing, and the closing cover can be fixed in a second position using the fixing element. In this way, unintended detachment of the tube from the pinch valve system can be prevented.

[0031] Further advantageous means and embodiments of the present invention are provided by the dependent claims.

[0032] The present invention will be described in more detail below with reference to examples and drawings. A partial schematic diagram shows the following: [Brief explanation of the drawing]

[0033] [Figure 1] This is a perspective view of an embodiment of the pinch valve system according to the present invention. [Figure 2] This is a cross-sectional view of an embodiment in the axial direction. [Figure 3] This is a perspective view of the closing cover and the side opening for receiving the tube in the embodiment. [Figure 4] This is a perspective view of the protective element in the embodiment. [Figure 5] This is a schematic diagram of an embodiment. [Figure 6] These are some diagrams illustrating the operation of the embodiment. [Figure 7] This is similar to Figure 5, but is a first modified example of the embodiment. [Figure 8] This is similar to Figure 5, but is a second modified example of the embodiment. [Modes for carrying out the invention]

[0034] Figure 1 shows a perspective view of an embodiment of the pinch valve system according to the present invention, which is collectively denoted by reference numeral 1. For better understanding, Figure 2 shows a cross-sectional view of the embodiment in the axial direction A, and Figure 5 shows a schematic diagram of the embodiment.

[0035] The pinch valve system 1 serves to clamp the tube 100 in the fluid system, in which case the tube 100 is inserted into the pinch valve system 1 and fixed within the system.

[0036] The pinch valve system 1 has a closure element 2 that is movably positioned in the axial direction A. The closure element 2 has a closure piece 21 for clamping a tube 100, and the closure piece 21 can cooperate with a tube pinch element 31 positioned on the closure cover 3 of the pinch valve system 1. The closure piece 21 and the tube pinch element 31 restrict a receptacle 4 for the tube 100 that is positioned between the closure piece 21 and the tube pinch element 31 in the axial direction, and the tube 100 can be inserted into the receptacle.

[0037] The pinch valve system 1 further comprises a permanent magnetic holding device 5, an electromagnetic operating device 6, an energy storage device 7, and a control unit 8.

[0038] The closing element 2, holding device 5, operating device 6, energy storage device 7, and control unit 8 are located within a common housing 10 of the pinch valve system 1, and a connector 11 is provided in the housing, allowing the pinch valve system 1 to be connected to an external energy source. The connector 11 can be further used for control lines or signal lines that can operate or program the pinch valve system 1, or to export data and other information from the pinch valve system 1.

[0039] The permanent magnetic retaining device 5 is designed to hold the closing element 2 in two different stable equilibrium positions, namely the open position and the closed position, by permanent magnetic force without requiring energy to be supplied to the permanent magnetic retaining device 5 to hold each equilibrium position. In this embodiment, the retaining device 5 has a permanent magnetic ring 51 positioned around the closing element 2 for this purpose.

[0040] In the open position shown in Figure 2, the tube 100 inserted into the receptacle 4 is not clamped or is only slightly clamped, thereby allowing liquid or fluid to flow through the tube 100, but the tube 100 is fixed in place. In the closed position, the tube 100 is clamped between the closing piece 21 and the tube pinch element 31 so that no more liquid can flow through the tube 100. In the open position (Figure 2), the flow cross-section of the liquid in the tube 100 is at its maximum. For closure, the closing element 2, and therefore the closing piece 21, is also moved to the left according to the figure (Figure 2), thereby compressing the tube 100 so that the flow cross-section becomes zero. As a result, in this closed position of the closing element 2, the tube 100 is clamped.

[0041] The electromagnetic actuation device 6 is designed to perform a switching process that can move the closing element 2 from an open position to a closed position or from a closed position to an open position. For this purpose, the electromagnetic actuation device 6 has at least one coil 61 which can be actuated by a control unit 8 to perform the switching process. A further electromagnetic force is exerted on the closing element 2 by the coil 61 for the switching process, and this electromagnetic force is strong enough to deflect the closing element 2 from one of its stable equilibrium positions (e.g., the open position) to the other of its two stable equilibrium positions (e.g., the closed position).

[0042] An important aspect is that the permanent magnetic holding device 5 can hold the closing element 2 in both equilibrium positions (open and closed positions) without energy, such as an electric current that would need to be supplied for this purpose. During holding, the pinch valve system 1 requires no electrical energy and is therefore very economical in terms of energy consumption in the two equilibrium positions.

[0043] The permanent magnetic retaining device 5 (see Figure 2) is located within the actuator housing 12, which forms part of the common housing 10. The actuator housing 12 is made of a ferromagnetic material. The retaining device 5 has a central passage 52 for receiving the closing element 2. The passage 52 extends axially A and has a first cylindrical region 521 to which a conical region 522 is connected, and the conical region 522 subsequently merges with a second cylindrical region 523, the diameter of which the second cylindrical region 523 is smaller than the diameter of the first cylindrical region 521. The conical region 522 and the second cylindrical region 523 are confined by an extension 121 of the actuator housing 12, which functions as a magnetic recirculation for guiding magnetic flux and is designed to be ferromagnetic. The extension 121 has a conical interface that extends obliquely with respect to the axial direction A and can cooperate with the surface of the closing element 2, which is also conical in shape. A sleeve 53, formed from a non-ferromagnetic material, such as plastic, is inserted into the first cylindrical region 521.

[0044] The closing element 2 has a cylindrical head 22, the outer diameter of which is matched to the inner diameter of a sleeve 53 in a first cylindrical region 521 of the passage 52, thereby allowing the head 22 to enter and be guided through the sleeve 53. The head 22 is formed from a ferromagnetic material and has a cone-shaped surface at its left end, as shown in Figure 2, which cooperates with the cone boundary surface of the extension 121. Furthermore, a rod 23 is attached to this end of the head 22, extending axially A through a second cylindrical region 523 of the passage 52, and a closing piece 21 is fixed to the left end of the rod 23, as shown in Figure 2.

[0045] Furthermore, the permanent magnetic ring 51, which is positioned to surround the head 22 of the closing element 2, is provided within the actuator housing 12.

[0046] The coil 61 is located within the actuator housing 12 adjacent to the permanent magnetic ring 51 and axially A, and functions as an actuation means for moving the closing element 2 from its open position to its closed position or vice versa. The coil 61 surrounds the passage 52 such that its coil axis extends axially A. Therefore, when current is supplied, the coil 61 can exert an electromagnetic force on the closing element 2 axially A, and this electromagnetic force can be directed to the right or left depending on the direction of the current, as shown in Figure 2.

[0047] The coil 61 has its axial end facing away from the permanent magnetic ring 51 adjacent to the extension 121 of the actuator housing 12. The coil 61 is further signal-connected to the control unit 8, which can supply electrical energy to the coil 61 and trigger the switching process.

[0048] For the existence of two stable equilibrium positions in which the closing element 2 can be held by permanent magnetic force without requiring further energy supply, and for a switching process in which the closing element 2 can be moved from the closed position to the open position or from the open position to the closed position by the electromagnetic force generated by the coil 61, please refer to the specification of European Patent Application No. 1132108 and the detailed description found therein, as previously stated.

[0049] According to the present invention, the energy storage device 7 is designed to store at least enough electrical energy to perform one switching process. Furthermore, a resting position, which is either an open or closed position, can be predetermined with respect to the control unit 8, in which case the control unit 8 can trigger a switching process that brings the closing element 2 to the resting position using the energy stored in the energy storage device 7.

[0050] The following will explain this in more detail based on the examples, with reference to Figures 1, 2, and 5.

[0051] In the embodiment described herein, the pinch valve system 1 is designed as a fully integrated bistable system, and in this system there is no return spring for the switching process or for holding each of the two stable equilibrium positions. The common housing 10 has an actuator housing 12, a closing housing 13, and a protective housing 14, the actuator housing 12 is positioned between the closing housing 13 and the protective housing 14 with respect to the axial direction A. The actuator housing 12, the closing housing 13, and the protective housing 14 are firmly connected to each other, for example by screws or other fastening means, so that they form the common housing 10.

[0052] The closing housing 13 has a closing cover 3 at its axial end, which faces away from the actuator housing 12. The closing cover 3 is connected to the closing housing 13 by an articulated joint and can move back and forth between a first position and a second position. In the first position (see also Figure 3), the tube 100 can be inserted into the receptacle 4. In the second position (see also Figure 4), the tube 100 is fixed to the common housing 10, i.e., between the tube pinch element 31 and the closing piece 21. Preferably, an indicator 131 is provided on the closing housing 13, which makes it externally recognizable whether the closing element 2 is in its open position or its closed position.

[0053] The energy storage device 7 and the control unit 8 are housed within the protective housing 14. Furthermore, a connection 11 is provided in the protective housing 14, allowing the pinch valve system 1 to be connected to an external energy source (not shown). Additionally, the control unit 8 can be operated and / or programmed via the connection 11. The connection 11 is connected to the energy storage device 7 and / or the control unit 8 via an electrical connection 78.

[0054] As shown in Figure 5, the control unit 8 includes a power supply unit 81 and an open-loop control unit 82. The power supply unit 81 has power electronics that, in particular, supply energy, and especially current, to the coil 61 of the actuating device 6 when the switching process is to be performed. For this purpose, the power supply unit 81 is connected to the coil 61 via a connector V1. The open-loop control unit 82 includes a controller or regulator for the operation of the pinch valve system 1 and optionally a memory module, processing module, or evaluation module for the operation of the pinch valve system 1.

[0055] Particularly preferably, the energy storage device 7 is designed as an intermediate circuit for supplying energy to the actuarial device 6. The energy storage device 7 can be connected to an external energy source on the one hand via electrical connections 78 and 11, and on the other hand via connection V1 to the coil 61 of the actuarial device 6. For example, the external energy source is a supply voltage such as a main line voltage, or another voltage source or current source.

[0056] Particularly preferably, the energy storage device 7 has at least one capacitor for storing electrical energy, in which case the capacitor, or the capacitor as a whole if there are several capacitors, has a capacity large enough to store enough electrical energy in the energy storage device 7 to perform at least one switching process even if there is a failure in the energy supply from an external energy source. The energy stored in the energy storage device 7 is preferably greater than the path of the integrated force along the stroke movement of the closing element 2 from the open position to the closed position.

[0057] The power electronics within the power supply unit 81 can be designed in any known manner suitable for operating the coil 61. For example, the power electronics can be designed as an H-bridge with overvoltage protection, the H-bridge being supplied with an intermediate circuit voltage provided by the energy storage device 7.

[0058] Preferably, a monitoring sensor 71 is provided in the common housing 10, and this monitoring sensor 71 can detect an interruption in the energy supply, i.e., a failure in the energy supplied by an external energy source. Generally, an external sensor can also be provided to send a signal to the control unit 8 when there is a failure in the external energy source, but a monitoring sensor 71 provided inside the common housing 10 is preferred. The monitoring sensor 71 is preferably located in the protective housing 14 and is signal-connected to the control unit 8, or more precisely to the open-loop control unit 82 of the control unit 8, via a signal line S1. The monitoring sensor 71 is preferably designed as a current sensor or a voltage sensor and is configured to detect a failure in the supply from the external power source. For example, a supply failure may be a interruption of the main line, or a collapse of the supply voltage, e.g., the main line voltage, or a lack of current flow.

[0059] For the operation of the pinch valve system 1, the tube 100 is inserted into the receptacle 4, and the closing cover 3 is brought to a second position where the tube is fixed between the closing piece 21 and the tube pinch element 31. A desired resting position, which is either the open or closed position, is predetermined for the open-loop control unit 82 of the control unit 8. Thus, it is predetermined for the control unit 8 whether the closing element 2 should be brought to the open or closed position when the external power supply fails.

[0060] If the monitoring sensor 71 detects a failure in the external energy supply, such as a lack of supply voltage, this information is transmitted to the open-loop control unit 82 of the control unit 8. The control unit 8 checks whether the closing element 2 is in a predetermined resting position. If the closing element 2 is in the predetermined resting position, no further steps are necessary as no energy supply is required to maintain the closing element 2 in the resting position. If the closing element 2 is not in the predetermined resting position, the open-loop control unit 82 sends a command to the power supply unit 81 that the switching process must be performed. The electrical energy required for this switching process is available in the energy storage device 7 so that the actuating device 6 can move the closing element 2 to the resting position. As soon as the closing element 2 is in the resting position, no further energy supply is required to maintain the closing element 2 in the resting position.

[0061] This operation is illustrated in Figure 6 by several schematic diagrams in which time t is plotted on the horizontal axis in all cases. Viewed from top to bottom, the following values ​​are plotted on the vertical axis: the supply voltage B1 provided by the external energy source, the detection of trunk line interruption (loss of external energy supply or supply voltage) B2, the operation of the open-loop control unit B3, and the energy B4 in the energy storage device 7.

[0062] The embodiment shown in Figure 6 illustrates the case where the closing element 2 is not in the resting position but is in the other of two stable equilibrium positions when the external energy supply is lost—for example, when the main line is interrupted and the supply voltage is lost.

[0063] At time t0, there is an interruption or loss of supply voltage B1. At time t1, the monitoring sensor 71 detects a fault in the external energy supply B2 and transmits this information to the open-loop control unit 82. The open-loop control unit B3 acts at time t2, that is, the switching process is initiated by the electrical energy stored in the capacitor of the energy storage device 7.

[0064] The energy B4 stored in the energy storage device 7 decreases due to the switching process. The switching process is completed at time t3, and the closing element 2 reaches a predetermined resting position.

[0065] It is understood that the energy B4 stored in the energy storage device 7, shown as an example in the bottommost diagram of Figure 6, does not need to reach a value of zero at time t3, and can have a value other than zero. This means that it can be assumed that the energy storage device 7 is not completely discharged at time t3, but that energy can still be stored in the energy storage device 7.

[0066] A preferred embodiment of the closed housing 13 with the closing cover 3 will be described below with reference to Figures 3 and 4. Figure 3 shows a perspective view of the closed housing 13 with the closing cover 3 in a first position, in which the tube 100 can be inserted into or removed from the receptacle 4 of the pinch valve system 1 (the tube is not shown in Figure 3). Figure 4 shows the closing cover 3 in a second position in which the tube 100 is fixed inside the receptacle 4. Here, the tube 100 is clamped between the tube pinch element 31 and the closing piece 21. For better understanding, only the closing cover 3 of the closed housing 13 is shown in Figure 4, with the rest removed so that the interior can be seen.

[0067] The closing housing 13 is provided with two lateral openings 32 on the side of the receptacle 4, and when the closing cover 3 is in the second position, the tube 100 can exit the closing housing 13 through these lateral openings 32. Thus, in this second position of the closing cover 3, the lateral openings 32 form two passages through which the tube 100 penetrates the common housing 10, or more precisely, the closing housing 13 of the common housing 10.

[0068] The closing cover 3 is positioned at the axial end of the closing housing 13 and connected to the closing housing 13 by an articulated joint, thereby allowing the closing cover 3 to rotate or tilt approximately 90° from a first position (Figure 3) to a second position (Figure 4). Furthermore, the closing housing 13 is provided with a fixing element 33 (Figure 3), which can fix the closing cover 3 in the second position, thereby safely preventing the closing cover 3 from unintentionally opening, i.e., unintentionally moving away from the second position. For example, the fixing element 33 is designed as a notched screw that can cooperate with a groove 331 of the closing cover 3 when the closing cover 3 is in the second position. The notched screw is received by the groove 331 in the second position of the closing cover. By tightening the notched screw, the closing cover 3 can be fixed or attached to the second position. Of course, it is understood that other embodiments of the fixing element 33 may be conceivable.

[0069] In a particularly preferred embodiment, the tube pinch element 31 is interchangeably arranged within the closing cover 3, thereby allowing the tube pinch element 31 to be easily replaced with another tube pinch element 31, for example, a tube pinch element 31 of a different size.

[0070] For this purpose, the closure cover 3 preferably has a recess 34 into which the tube pinch element 31 can be inserted. In Figure 3, for better understanding, the tube pinch element 31 is shown outside the recess 34. The tube pinch element 31 can be easily inserted into or removed from the recess 34 of the closure cover 3, as indicated by two arrows without reference numerals in Figure 3. Preferably, the recess 34 has two lateral grooves that surround and guide the tube pinch element 31 so that it is secured in the recess 34.

[0071] The tube pinch element 31 has two lateral tube supports 35, each designed to be flat and rounded in a U-shape or V-shape, so that the tube 100 is partially surrounded by the tube supports 35. Furthermore, the tube pinch element 31 has a central pinch element 36, which is positioned in the center between the two tube supports 35 and is designed so that the side 31 facing the tube 100 in the operating state is rounded, preferably convexly rounded. In the operating state, the tube 100 is clamped between the closing piece 21 and the central pinch element 36 of the tube pinch element 31 in the closed position of the closing element 2.

[0072] Preferably, several interchangeable tube pinch elements 31 are provided so that, for a particular application, an appropriate tube pinch element 31 can be selected according to the dimensions of the tube 100, particularly the outer and / or inner diameter of the tube 100. For example, in the case of a tube 100 with a smaller outer and / or inner diameter, a tube pinch element 31 can be used that is higher than the tube pinch element 31 provided for a tube 100 with a larger outer and / or inner diameter, i.e., has a central pinch element 36 that extends further into the receptacle 4.

[0073] The shape and design of the tube support 35 can also be changed with respect to different tube pinch elements 31.

[0074] Furthermore, it is preferable to provide a protective element 25 that is movable in the axial direction A, and this protective element 25 is loaded by a spring 27 such that the protective element 25 covers the two lateral openings 32 when the closing cover 3 is in the first position shown in Figure 3. The protective element 25 has two side walls 251 positioned on both sides of the closing piece 21, thereby positioning the closing piece 21 between the two side walls 251. The side walls 251 are located inside the closing housing 13, and each side wall 251 is in front of one of the lateral openings 32. With respect to the axial direction A, the side walls 251 are dimensioned such that they terminate flush with the lateral openings 32 in the first position of the closing cover (Figure 3), i.e., they do not completely cover the lateral openings 32 and protrude beyond the lateral openings 32 in the axial direction A. Therefore, when the tube 100 is not inserted into the pinch valve system 1, the two lateral openings 32 are completely covered by the side walls 251 of the protective element 25 in both the first and second positions, thus functioning as a finger guard to prevent unintended access to the lateral openings 32.

[0075] In other embodiments, the side walls 251 may also be designed to be somewhat shorter in the axial direction, such that they do not completely close the lateral opening, but preferably to the extent that they prevent fingers from unintentionally reaching it.

[0076] Furthermore, a guide rail 26 is provided in the closing housing 13 to guide the protective element 25 in the axial direction A, thereby allowing the protective element 25 to move back and forth in the axial direction A along the guide rail 26. A spring 27 is provided between the protective element 25 and the closing element 2, and this spring 27 is positioned to pre-pressure the protective element 25 to the position shown in Figure 3, where the side wall 251 of the protective element 25 completely covers the lateral opening. Therefore, in order to insert the tube 100 into the receptacle 4, the protective element 25 must be moved against the force of the spring 27 such that the side wall 251 does not at least partially cover the lateral opening 32. When the tube 100 is inserted into the receptacle 4, the protective element 25 is moved axially with the tube 100 against the force of the spring 27 until the tube 100 is positioned in the receptacle 4 and the lateral opening 32. The closing cover 3 is then brought to a second position, where it is fixed by a fixing element 33.

[0077] The protective element 25, with its two side walls 251, further serves to center the tube 100, especially in the case of a tube 100 having a small outer diameter. The tube 100 is further secured by the side walls 251, thereby ensuring that the tube 100 does not move relative to the receptacle 4 when the closing cover 3 is in the second position (see Figure 4), even if the tube 100 has a small outer diameter. Furthermore, the protective element 25 prevents uneven pinching of the tube 100 and the introduction of eccentric forces onto the closing piece 21.

[0078] In the representation corresponding to Figure 5, Figure 7 shows a first modification of the embodiment described above. In this first modification, a measuring sensor 72 is further provided for determining the energy stored in the energy storage device 7. The measuring sensor 72, which may be designed as a voltage sensor, is signal-connected to the open-loop control unit 82 of the control unit 8 via a signal line S2. The measuring sensor 72 monitors the energy storage device 7 and enables estimation of whether the switching process can still be performed using the energy available in the energy storage device 7. For example, the measuring sensor 72 may be designed as a voltage measuring unit configured to measure the voltage of a capacitor. The electrical energy stored in the capacitor can be estimated from the voltage of the capacitor in the energy storage device 7. The energy currently stored in the capacitor can then be compared, for example, with the electrical energy required for the switching process in the open-loop control unit 82.

[0079] As a further option, a position sensor 73 can be provided to determine the position of the closing element 2. For this purpose, any sensor that is known in itself and capable of determining the position of the closing element 2 is suitable. In particular, the position sensor 73 can recognize whether the closing element 2 is in the open position or the closed position. The position sensor 73 is signal-connected to the open-loop control unit 82 of the control unit 8 via the signal line S3.

[0080] When the monitoring sensor 71 detects that the energy supply from the external power source has been cut off, the open-loop control unit 82 checks which is the predetermined resting position. The open-loop control unit 82 receives information from the position sensor 73 regarding the current position of the closing element 2, i.e., whether the closing element 2 is in the open position or the closed position. If the current position of the closing element 2 corresponds to the resting position, no further action is required and no further action is taken. If the current position of the closing element 2 does not correspond to the predetermined resting position, the open-loop control unit 82 issues a command to the power supply unit 81 indicating that the switching process should be executed. The actuation device 6 is controlled accordingly, and therefore the closing element 2 is moved to the desired resting position. Subsequently, the position sensor 73 can further check whether the closing element 2 has reached the predetermined resting position.

[0081] Of course, it is not necessary to provide both the position sensor 73 and the measurement sensor 72, but it is possible. In other embodiments, only the position sensor 73 may be provided, and the measurement sensor 72 may not be provided. In yet another embodiment, only the measurement sensor 72 may be provided, and the position sensor 73 may not be provided.

[0082] In the representation corresponding to Figure 5, Figure 8 shows a second modification of the described embodiment. In this second modification, compared to the first modification (Figure 7), an additional current sensor 74 for determining the switching current is provided, and this current sensor 74 is signal-connected to the open-loop control unit 82 of the control unit 8 via the signal line S4. The switching current is the current required for each switching process.

[0083] The switching current can be defined as the closing current, in which case the closing current is the current required for the switching process from the open position of closing element 2 to the closed position of closing element 2.

[0084] The switching current can be defined as the open-circuit current, in which case the open-circuit current is the current required for the switching process from the closed position of closing element 2 to the open position of closing element 2.

[0085] Therefore, the current sensor 74 is configured and designed to determine the current supplied to the actuator 6, particularly the current supplied to the coil 61 of the actuator 6. The current sensor 74 allows the current required for the switching process from the open position to the closed position or from the closed position to the open position to be determined over the entire stroke of the closing element 2 from the open position to the closed position or from the closed position to the open position.

[0086] In particular, in this embodiment, it is conceivable that tube detection based on switching current is performed by the pinch valve system. For this purpose, for example, the correlation of which closing current and / or opening current is required for which type of tube to perform the switching process from open to closed position or vice versa can be stored in an assignment table in the open-loop control unit 82 of the control unit 8. For example, the tube type may include information about the material, outer diameter, inner diameter, wall thickness, and other parameters as needed for each tube. In that case, the assignment table is a multidimensional table in which the correlation between a value that determines the tube type and the required switching current is stored. Based on the switching current captured by measurement and, if necessary, the signal from the position sensor 73, it is possible to identify the tube 100 inserted into the pinch valve system 1.

[0087] Furthermore, based on a switching process performed from a closed position to an open position or from an open position to a closed position, and the measured detection of the switching current required for this process, it is possible to detect whether or not the tube 100 is inserted into the receptacle 4 of the pinch valve system 1.

[0088] Of course, embodiments in which tube detection is performed based solely on the closing current or solely on the opening current are also conceivable. Multiple switching processes can be performed for tube detection, and the required opening or closing current can be measured each time. For example, a switching process can be performed from the open position to the closed position, and then a switching process can be performed from the closed position to the open position.

[0089] In particular, tube detection can also be performed with respect to tubes 100 through which fluid is not yet flowing, i.e., empty tubes 100.

Claims

1. A pinch valve system for clamping a tube in a fluid system, a closing element (2) arranged to be movable in the axial direction (A), the closing element (2) having a closing part piece (21) for clamping the tube (100); a permanent magnetic holding device (5) designed to hold the closing element (2) in two different stable equilibrium positions, namely an open position and a closed position, by permanent magnetic force, such that the permanent magnetic holding device (5) can hold the closing element (2) in each of the respective equilibrium positions without the need to supply energy to the permanent magnetic holding device (5); an electromagnetic actuating device (6) for performing a switching process of moving the closing element (2) from the open position to the closed position or from the closed position to the open position; and having an energy storage device (7) and a control unit (8) are provided, the energy storage device (7) can store at least sufficient electrical energy to perform the switching process, a rest position which is the open position or the closed position can be predetermined for the control unit (8), and the control unit (8) can trigger a switching process to bring the closing element (2) to the rest position by the energy stored in the energy storage device (7). A pinch valve system characterized by this.

2. The closing element (2), the holding device (5), the actuating device (6), the energy storage device (7) and the control unit (8) are arranged in a common housing (10), and the housing (10) has a connection part (11) for connecting to an external energy source. The pinch valve system according to claim 1.

3. A monitoring sensor (71) capable of detecting interruption of energy supply from the external energy source is provided in the common housing (10). The pinch valve system according to claim 2.

4. The permanent magnetic holding device (5) has a permanent magnetic ring (51) surrounding the closing element (2). The pinch valve system according to claim 1.

5. The energy storage device (7) is designed as an intermediate circuit for supplying energy to the actuating device (6). The pinch valve system according to claim 1.

6. The pinch valve system according to claim 1, wherein a position sensor (73) is provided for determining the position of the closing element (2).

7. The pinch valve system according to claim 1, wherein a measurement sensor (72) is provided for determining the electrical energy stored in the energy storage device (7).

8. The pinch valve system according to claim 1, wherein a current sensor (74) is provided for determining a switching current, which is the current required for the switching process.

9. The pinch valve system according to claim 8, wherein tube detection can be performed based on the switching current.

10. The pinch valve system according to any one of claims 2 to 9, wherein two side openings (32) for receiving a tube (100) are provided in the housing, and a closing cover (3) connected to the housing (10) by a joint is provided, the closing cover can be reciprocated between a first position and a second position, in the first position, the tube (100) can be inserted into the side opening (32), and in the second position, the tube (100) is fixed to the housing (10) of the pinch valve system (1).

11. The pinch valve system according to claim 10, wherein a tube pinch element (31) for cooperating with the closing part piece (21) of the closing element (2) is arranged in the closing cover (3), so that when the closing cover (3) is in the second position, the tube (100) can be clamped between the closing part piece (21) and the tube pinch element (31).

12. The pinch valve system according to claim 11, wherein the tube pinch element (31) is designed and arranged to be replaceable.

13. The pinch valve system according to claim 12, wherein a recess (34) is provided in the closing cover (3), and the tube pinch element (31) can be inserted into the recess (34).

14. A protective element (25) movable in the axial direction (A) is provided, and the protective element (25) is loaded by a spring (27) such that the protective element (25) covers the two lateral openings (32) when the closing cover (3) is in the first or second position and the tube (100) is not inserted into the pinch valve system. The pinch valve system according to claim 10.

15. A fixing element (33) is provided on the housing, and the closing cover (3) can be fixed in the second position by the fixing element (33). The pinch valve system according to claim 10.

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