Valve device, molding machine, and method for controlling valve device

Abstract

To provide a valve device having a check valve mechanism comprising a valve rod and a closing element that is disposed on one end of the valve rod and intended for supply of compressed air to a consumption side.SOLUTION: A valve device further has an actuation mechanism having a hydraulic cylinder, in which a piston of the hydraulic cylinder is firmly connected to the valve rod and is hydraulically driven within a cylinder casing of the hydraulic cylinder to actuate the check valve mechanism. A control mechanism for controlling piston movement and a measuring mechanism for detecting a piston position are comprised, and a proportional-valve mechanism, which is controllable by the control mechanism as a function of the piston position, is connected to the hydraulic cylinder in a fluid-conducting manner. The present invention further relates to a molding machine and a method for controlling a valve device.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a valve device having a check valve mechanism with a valve rod and a closing element arranged at one end of the valve rod and intended for supplying compressed air to a consumption side, the valve device further having an actuating mechanism with a hydraulic cylinder, the piston of which is rigidly connected to the valve rod and hydraulically driven within a cylinder casing of the hydraulic cylinder for actuating the check valve mechanism. The present invention also relates to a molding machine and a method for controlling the valve device. [Background technology]

[0002] When compacting molding material, such as foundry sand, in a molding machine to produce a mold from the material, as well as in other similar applications, compressed air is typically supplied to the consumer side, such as the molding flask of the molding machine. However, the compressed air used to compress the molding material should not be applied suddenly, as this would prevent uniform compression throughout the molding sand. On the other hand, if it takes too long for the compressed air supplied to the consumer side to reach the required pressure, the corresponding mechanism will function inefficiently. Pneumatic check valves, which can be closed or opened using an actuating mechanism, are periodically supplied to ensure efficient application of compressed air. The check valve's closing element closes or opens a cylinder casing that can be filled with compressed air. When the check valve is open, the compressed air flows toward the consumer side. Check valves can be operated, for example, using hydraulically operated actuating mechanisms. Such common actuating mechanisms usually include a discretely switching directional valve, such as a 4 / 2-way valve, to operate a hydraulically operated movable cylinder connected to the check valve. In other words, this means that the air flow can generally be directed to the consumer side by a discretely controlled hydraulic cylinder. Both the piston stroke and the discrete opening time of the check valve are generally manually set and readjusted, which can result in excessive consumption of compressed air, which is relatively expensive to produce. In addition, the discrete switching behavior of the one-way valve controlling the hydraulic cylinder does not offer the possibility of actively adjusting and controlling the air flow, for example, to optimize the compression of the molding material. This significantly reduces the precision and accuracy of the compressed air supply to the consumer side and increases energy losses. Summary of the Invention [Problem to be solved by the invention]

[0003] It is therefore an object of the present invention to devise a valve device and a method for controlling the valve device that can actively regulate and control the supply of compressed air flow to the consumer, ensuring increased energy efficiency. Furthermore, the device and / or method according to the present invention should be easy to implement, manufacture and use. Furthermore, the valve device and / or method should be able to be implemented without significantly increasing the current required cycle time of standard required installations in which the valve device or method is used. [Means for solving the problem]

[0004] To achieve this object, an apparatus is proposed having the features of independent claim 1. Furthermore, a molding machine is proposed having such a valve arrangement. A method for controlling a check valve mechanism is also proposed having the features of claim 14.

[0005] The valve device according to the present invention includes a check valve mechanism including a valve rod and a closing element disposed at one end of the valve rod for supplying compressed air to a consumer side, such as a molding flask containing molding material to be compressed. The valve device also includes an actuating mechanism having a hydraulic cylinder, the piston of which is rigidly connected to the valve rod and hydraulically driven within the cylinder casing of the hydraulic cylinder to operate the check valve mechanism. In other words, the piston can be moved within the cylinder casing by hydraulic pressure. Because the valve rod is rigidly connected to the piston of the hydraulic cylinder, movement of the piston also moves the valve rod to which the closing element is attached, allowing or blocking the supply of compressed air to the consumer side. The closing element can be configured, for example, as a valve cone or a valve disc. The closing element can interact with the valve seat such that it rests on the valve seat when the compressed air supply to the consumer side is blocked, sealing the consumer side against the compressed air supply. The closing element can be subjected to the load of compressed air flow in the closing direction of the check valve mechanism. The valve rod is preferably provided on the closure element on the side facing the valve seat, the longitudinal axis of the valve rod preferably extending parallel to the direction of movement of the piston.

[0006] The valve device according to the present invention is characterized in that it comprises a control mechanism for controlling piston movement and a measurement mechanism for detecting piston position. The piston movement may preferably be piston stroke movement. By connecting the piston to a closing element of the check valve mechanism, the position of the check valve mechanism, and therefore the compressed air supply to the consumer side, can be adjusted by controlling the piston movement. In the context of the present invention, it is recognized that a measurement mechanism for determining piston position is advantageous for controlling piston movement. The piston position can also be used to determine the piston stroke, also called stroke length, and / or the position of the closing element of the check valve mechanism.

[0007] Furthermore, it is recognized that it is essential in the context of the present invention that a proportional valve mechanism, controllable by a control mechanism as a function of the piston position, is fluidly connected to the hydraulic cylinder. The proportional valve mechanism is supplied with a corresponding compressed fluid source and is fluidly connected to the hydraulic cylinder so that the supply and discharge of compressed fluid, which can also be called hydraulic oil, can be supplied to and discharged from the hydraulic cylinder. For this purpose, hydraulic lines can be arranged between the hydraulic cylinder and the compressed fluid source, and the proportional valve mechanism is arranged between the hydraulic cylinder and the compressed fluid source.

[0008] In the context of the present invention, a proportional valve mechanism is a continuous valve device that allows not only discrete switching positions but also continuous transitions of the valve opening, preferably by means of a proportional magnet. This allows a variable volume flow (in this case, compressed fluid) to be supplied to the hydraulic cylinder. The proportional valve mechanism is electromagnetically controllable and can assume any intermediate position between fully open and fully closed. To adjust the volume flow that can be discharged, the proportional valve mechanism can have at least one, preferably several, axially displaceable valve pistons as shutoff bodies that connect or close the corresponding inlet and outlet connections. In this way, the proportional valve direction of the valve device according to the present invention allows precise control of the volume flow of compressed fluid supplied to the hydraulic cylinder through the continuous switching behavior of the proportional valve mechanism. The proportional valve mechanism can be operated in a current-controlled and / or voltage-controlled manner.

[0009] In the context of the present invention, it is recognized that both the velocity and acceleration of the piston during piston movement can be determined based on a determination of piston position over time, and thus the control mechanism can control the proportional valve mechanism in dependence on piston position, piston velocity and / or piston acceleration.

[0010] The control mechanism, coupled with the active monitoring of the piston position and / or movement by the measurement mechanism, means that changes in the piston movement, particularly its travel distance, can be detected early and appropriate readjustments can be made. Additionally, the measurement mechanism and / or control mechanism can detect the need for maintenance early and perform remote maintenance, for example, via a remote connection, thereby improving the ability to plan maintenance work and reducing costs. Furthermore, the valve device according to the present invention allows for simple commissioning of the valve device and the consumer connected to it. This is because adjustment of the piston movement, particularly the piston stroke, no longer needs to be performed manually by a mechanic, for example, via a throttle, but can be performed automatically using the control mechanism. Subsequent adjustments of the valve device, for example, when replacing the consumer, can also be performed via the control mechanism, for example, by inputting desired target values ​​via an interface to the control mechanism, without manually adjusting the check valve mechanism or the actuation mechanism itself. Furthermore, the compressed air output to the consumer can also be adapted much more variably and flexibly to the consumer, which can improve the application of compressed air to the consumer, for example, for compacting foundry sand. Advantageously, the opening time of the check valve mechanism can also be controlled more precisely, which may increase energy efficiency. The assembly of the valve device according to the present invention does not require additional effort compared to conventional valve devices, as it can be easily attached to the consumer or integrated into an existing consumer.

[0011] The valve device according to the invention can preferably be arranged in a molding machine, in particular a machine for producing moulds, or in a core shooter.

[0012] Advantageous embodiments of the present invention are the subject of the dependent claims. In addition, all combinations of at least two features disclosed in the present specification, claims and / or drawings are included within the scope of the present invention. It is understood that any statements made regarding the valve device also refer to the molding machine according to the present invention, even without separate mention. Likewise, all features and embodiments disclosed regarding the valve device and / or molding machine are equally relevant, albeit not identical, to the method according to the present invention. In particular, it is understood that the present disclosure includes customary linguistic synonyms and / or meaningful substitutions of respective terms within the framework of customary linguistic practice, even without explicit mention in the respective formulations, in particular by using synonyms supported by generally recognized linguistic literature.

[0013] The measurement mechanism may have a laser triangulation sensor and / or a touchless path sensor and / or an ultrasonic distance sensor to detect the piston position. The displacement measurement sensor may preferably be configured as a magnetostrictive path sensor. In other words, the measurement mechanism can determine the piston position using laser triangulation and / or magnetostrictive path measurement and / or ultrasonic distance measurement. Furthermore, the measurement mechanism may be configured to detect not only the piston position but also a change in the piston position over a period of time, thereby allowing the measurement mechanism to determine the velocity and / or acceleration of the piston. The path measurement is advantageously contactless.

[0014] A laser triangulation sensor has at least one radiation source and one detector with an optical system. Light from the radiation source, preferably a laser, is irradiated onto a measurement object, in this case a piston, and reflected at a specific triangulation angle. The reflected light is then detected via the optical system on a detector. The distance to the piston, and thus the position of the piston, can be determined through the position and the light spot area. A magnetostrictive path sensor for determining position can have a magnetostrictive measuring element configured as a measuring rod, e.g., a position magnet, and evaluation electronics. The position magnet can be a permanent magnet and can be located inside or on the piston. To determine the piston position, a current pulse can be applied to the measuring element, which generates a magnetic field around the measuring element. The magnetic field lines of the measuring element can intersect with the magnetic field of a position magnet, which can be located on the piston. This intersection of the magnetic field lines can deform the magnetostrictive measuring element. This mechanical deformation can be related to the elapsed time since the start of the current pulse, and thus the current position of the position magnet and, therefore, the current position of the piston can be determined. By using magnetostrictive displacement sensors, resolutions of up to 1 μm and measurement frequencies of up to 10,000 Hz can be achieved. Additionally or alternatively, piston position can be determined using at least one ultrasonic sensor based on the transit time of a reflected ultrasonic pulse. The ultrasonic sensor includes an output stage, an ultrasonic transducer, and an evaluation unit. The output stage excites the ultrasonic transducer via a sinusoidal voltage to emit an ultrasonic pulse, which is reflected by the piston. Piston position can be determined by evaluating the time from signal output to reception of the reflected signal, or through the sound propagation velocity. Preferably, resolutions of up to 0.3 mm and measurement frequencies of 250 Hz to 500 Hz can be achieved. Position determination using ultrasonic sensors is advantageously inexpensive and easy to implement.

[0015] The proportional valve mechanism can be configured as a 4 / 4 proportional valve and / or can include at least one 4 / 4 proportional valve. In the context of the present invention, it is recognized that discretely switching directional valves, typically configured as 4 / 2 directional valves, are not suitable for controlling piston movement and therefore the entire valve device. For this reason, a 4 / 4 proportional directional valve is preferred, in which the position of the valve piston can be changed by electrically controlling an electromagnet, thereby precisely controlling the volumetric flow rate. A 4 / 4 proportional valve can include a rod, magnets (also known as armatures) located at each end of the rod, a valve piston that can control the volumetric flow rate entering and / or leaving the connection, and a coil through which the magnets are subjected to a horizontal force. Passing a current through the coil generates a magnetic field, which exerts a force on the rod and / or the valve piston. A 4 / 4 proportional valve can have four connections, preferably a tank (T) connection, a pressure (P) connection, and consumption connections A and B, whose volumetric flow rates can be adjusted via various valve piston positions.

[0016] The pressure connection and the tank connection are connected to a compressed fluid source, and compressed fluid can be supplied to the proportional valve via the pressure connection and discharged from the proportional valve via the tank connection. One of the consumer connections A and B can be configured to supply compressed fluid to the hydraulic cylinder, while the other consumer connection can be configured to discharge compressed fluid from the hydraulic cylinder. Furthermore, the valve's piston position can be moved to four cardinal positions. When no current is applied to the coil, the magnet moves to its home position via the return spring and consumer connections A and B are closed. In the event of a malfunction and / or when no signal is applied, the valve piston can be moved to a so-called "fail-safe" position, in which the return spring is fully relaxed. At the rightmost position, the tank connection part and the consumption side connection part A, and the pressure connection part and the consumption side connection part B are connected to each other, and at the leftmost position, the tank connection part and the consumption side connection part B, and the pressure connection part and the consumption side connection part A are connected to each other.

[0017] The valve piston of the proportional valve mechanism can be displaced by controlling the current. Specifically, the valve piston can be displaced by applying a current of 4 to 20 milliamps (mA) to the coil of the proportional valve mechanism. A value of 12 mA can be set as the threshold that determines the direction of movement of the valve piston.

[0018] The control mechanism may comprise a PID controller (proportional integral derivative controller). The PID controller may take into account piston position and / or piston movement, whereby the piston position and / or piston movement may be an input signal for the PID controller. The output signal of the PID controller may be a control signal that is used to control a proportional valve mechanism, via which the volumetric flow rate of compressed fluid in the hydraulic cylinder may be varied. For example, the output signal of the PID controller may be a correction current that can be used to vary the position of the valve piston of the proportional valve mechanism. The control mechanism may be configured as a digital control mechanism. The control mechanism may comprise an analog-to-digital converter that records the control variable and a digital-to-analog converter that outputs the control variable.

[0019] The piston of the hydraulic cylinder may be double-acting. This double-acting piston can advantageously be moved and / or driven in two directions, thereby eliminating the need for a reset mechanism. To drive the double-acting piston, compressed fluid can be supplied to the hydraulic cylinder at at least two openings, thereby lowering and raising the piston.

[0020] The piston rod can be positioned on the piston of the hydraulic cylinder, facing the valve rod and flush with its axis. The valve rod and piston rod can have different diameters. Because the piston rod and valve rod have different diameters, the piston has two unequal piston surfaces. This results in different volumes in the two cylinder chambers, making it possible to advantageously adjust the pressure ratio for moving the piston within the hydraulic cylinder. The piston rod can have a diameter between 50 mm and 60 mm, preferably 56 mm, and the valve rod can have a diameter between 40 mm and 50 mm, preferably 45 mm.

[0021] The piston movement can be limited by a fixed stop element. Preferably, the stop element is adjustable. In this way, the maximum compressed air flow rate can be advantageously determined by the check valve mechanism, since the stroke of the closing element is limited by the fixed stop element. If the stop element is adjustable, the maximum opening of the check valve mechanism can be easily adapted to different requirements.

[0022] The piston rod can be arranged on the piston of the hydraulic cylinder, facing the valve rod and flush with the axis of the valve rod. The free front face of the piston rod facing away from the closure element can abut against the stop element. In other words, the piston rod can contact the stop element with its front face facing away from the closure element, thus limiting the stroke movement of the piston. To limit the piston stroke using the stop element, it does not matter whether the piston rod and the valve rod have different or the same diameter. The valve rod and piston rod can be constructed as a single unit. It is also conceivable to construct the piston, valve rod, and piston rod of a hydraulic cylinder as a single unit.

[0023] When limiting the piston stroke, it may be advantageous to provide a stop damper on the free front face of the piston rod and / or on the stop element.

[0024] The valve device may have a fixed return spring arranged so that the valve rod is moved against the spring force of the return spring when the check valve mechanism is opened. The return spring may be arranged so that it is supported stationary on a stop element on the one hand and axially movable on a support element arranged on the piston rod on the other hand. The support collar of the support element may be attached so that the return spring is largely guided on the piston rod. The return spring may be configured as a coil spring. The return force of the return spring may have a linear spring characteristic curve with a constant spring constant and acts in the direction of closing the check valve mechanism. Furthermore, the return force of the return spring may be configured so that it does not change the valve characteristic curve of the valve shut-off device.

[0025] The adjustable pressure control mechanism may be disposed upstream of the proportional valve element. The pressure control mechanism may be disposed between the proportional valve mechanism and the compressed fluid source. The pressure control mechanism may be configured as a pressure reducing device. By controlling the pressure, a predetermined pressure of the compressed fluid flow can be easily adjusted mechanically and / or electronically.

[0026] In a second aspect, the present invention relates to a molding machine for compressing a molding material, the molding machine having a molding flask that can be filled with the molding material, a pattern placed in the molding flask, and the molding flask connected to a compressed air source. In this regard, the molding machine has a valve device for releasing the compressed air supply to the molding flask, and the mold is formed by compressing the molding material after it is subjected to pressure. The molding machine can be configured, for example, for making molds or cores. The molding material can be foundry sand, clay-bonded and / or bentonite-bonded green sand. By applying compressed air, the molding material is compressed onto the pattern using an air flow. For final compression of the molding material, the molding material can be further compressed, for example, using a hydraulically driven stamping press, and different numbers of stamps can be used depending on the outer shape and dimensions of the mold. The air introduced during the application of compressed air can escape from the molding flask through at least one nozzle and / or at least one vent valve.

[0027] In a third aspect, the present invention relates to a method for controlling a valve device having a check valve mechanism with a valve rod and a closing element arranged on one end of the valve rod and intended for supplying compressed air to a consumer side. The valve device further comprises an actuation mechanism with a hydraulic cylinder, the piston of which is rigidly connected to the valve rod and can be hydraulically driven within the cylinder casing of the hydraulic cylinder to actuate the check valve mechanism. According to the present invention, the piston position is determined using a measurement mechanism, and the piston movement is controlled by a proportional valve mechanism fluidly connected to the hydraulic cylinder as a function of the determined piston position, so that the volumetric flow rate of hydraulic fluid supplied to the hydraulic cylinder is varied. The method according to the present invention prevents abrupt opening of the compressed air supply to the consumer side and achieves an adjustable opening behavior. In particular, the volumetric flow rate of compressed fluid discharged through the outlet of the proportional valve mechanism can be continuously varied and thus adjusted. In particular, the volumetric flow rate of compressed fluid supplied to the hydraulic cylinder can be controlled as a function of the determined piston position by adjusting the valve piston of the proportional valve mechanism with current control. Preferably, the method according to the invention may be used to control the valve arrangement according to the first aspect of the invention.

[0028] According to one embodiment of the method, the piston position and / or piston stroke can be determined at regular time intervals using a measurement mechanism and transmitted as an actual value to a control device. The actual value can be compared with a target value using a control mechanism, and if the target and actual values ​​differ, the control signal issued to control the proportional valve mechanism can be modified using the control mechanism. Since the measurement mechanism is configured to determine the piston position, it can also determine the piston stroke. This is because, in the context of the present invention, the piston stroke is defined as the distance the piston travels when compressed fluid is applied to the hydraulic cylinder. The maximum piston stroke means that the closing element is at its farthest distance from the valve seat when the compressed air supply is fully opened. Since the piston position at the bottom end position, where the compressed air supply to the consumer side is closed, is known, the maximum piston stroke, i.e., the distance between the bottom end position and the top end position, can be easily determined by detecting the piston position at the top end position. Depending on the requirements, for example, on the molding material and / or the flask of the model, a target value for applying pressure to the consumer side can be stored in the control mechanism. This target value can be compared with the actual value at regular intervals, for example, each time the actual value is recorded. It is understood that the actual value and the target value can have the same dimensions, for example, a piston stroke in millimeters. If there is a difference between the target value and the actual value, the control signal issued to control the proportional valve mechanism, which can in particular be in the form of a control current, can be adjusted by the control mechanism, preferably automatically. This facilitates control of the compressed air supply without the need for manual intervention and / or empirical values.

[0029] Further advantageous embodiments of the method are derived from the characterizing statements of the dependent claims which refer back to apparatus claim 1 and the apparatus claims relating to the molding machine.

[0030] The preferred embodiments are described in more detail below with reference to the accompanying drawings. [Brief explanation of the drawings]

[0031] [Figure 1]1 is a cross-sectional view showing an embodiment of a molding machine according to the present invention. [Figure 2] 1 is a cross-sectional view showing an embodiment of a valve device according to the present invention. [Figure 3] 1 is a diagram showing an embodiment of a 4 / 4 proportional valve of a valve device according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0032] FIG. 1 shows a molding machine 70 according to the present invention, including a valve device 10 according to the present invention. A molding material 71 can be filled into a flask 72 through a metering device (not shown) to cover a pattern 73. After supplying compressed air through the valve device 10, the molding material 71 can be compressed using a compression mechanism 74 to produce a mold for producing a casting corresponding to the pattern 73, for example. A compressed air source 13 supplies the compressed air necessary for applying the compressed air and is connected to the valve device 10 to transmit the compressed air. To supply compressed air to the flask 72, the valve device has an actuating mechanism 30 to which compressed fluid H can be supplied. The volumetric flow rate of the compressed fluid H supplied to the actuating mechanism 30 can be controlled and varied using a proportional valve mechanism 60. By opening a check valve mechanism 20 using the actuating mechanism 30, the compressed air flow can be supplied to the flask 72 and directed to the pattern 73. The compressed air source 13, e.g., a compressed air tank, is directly attached to the valve device 10 to ensure a sufficient compressed air supply and minimize air pressure loss. 1 shows that when check valve mechanism 20 is opened, compressed air flows through compression mechanism 74 into preferably sealed flask 72. The air can then escape from flask 72 through air outlet 75, which can be formed, for example, as a nozzle or a vent valve. After the molding material 71 has been dispensed and pre-compressed by application of compressed air, it can be compressed through compression mechanism 74, which is preferably hydraulically operated, to obtain the shape required.

[0033] 2 shows a valve device 10 on which a consumer side 11 is arranged, which can be configured, for example, as a mold flask 72. The check valve device 20 for a compressed air flow D from a compressed air source 13, which is connected, for example, to an inlet flange of a multi-part check valve casing 23 of the check valve device 20, comprises a valve seat 24 which interacts with a closure element 22 configured as a valve disc to cut off the compressed air supply to the consumer side 11. The closure element 22, which can abut against the valve seat 24, is connected to one end of a valve rod 21, which is mounted in a passage for longitudinal movement, which passage is aligned with the valve seat 24 and leads to the cylinder casing 33 of the hydraulic cylinder 31. The closure element is therefore movable within the check valve casing 23 relative to the valve seat 24, thereby allowing the compressed air flow D to be supplied to the consumer side 11. The compressed air flow D flows from the compressed air source 13 into the check valve casing 23 via a connecting joint 25 arranged on the check valve casing 23. A fixed stop element 35 is rigidly connected to the cover of the cylinder casing 33, and the distance between the stop element 35 and the cylinder casing 33 can be variably adjusted. The front surface 34a of the piston rod 34 can impact against the stop element 35 via a stop damper 35b. FIG. 2 shows the check valve mechanism 20 in the closed state, where the free stroke of the piston 32, and therefore the free stroke of the closure element 22, determined by the stop element 35, is visible. A return spring 36 can be in contact with the stop element 35 and can be configured as a coil spring surrounding the piston rod 34. The return spring 36 can be supported on the support collar 37 with its end farthest from the stop element 35 so that the return spring 36 is located between the stop element 35 and the support collar 37. The cylinder casing 33 has two passages 38 so that compressed fluid H (which may also be referred to as hydraulic oil) can be supplied to the cylinder casing 33 from hydraulic piping 39. The hydraulic piping 39 connects the passages 38 to a proportional valve mechanism 60, which in turn connects the proportional valve mechanism 60 to a compressed fluid source 14, such as a hydraulic pump. The proportional valve mechanism 60 can continuously vary the volumetric flow rate of the compressed fluid H to the hydraulic cylinder 31 of the actuation mechanism 30.Before the compressed fluid H is supplied from the compressed fluid source 14 to the proportional valve mechanism 60, the compressed fluid H can pass through a pressure control device 12, which is configured, for example, as a pressure reducing device, meaning that the pressure of the compressed fluid H supplied by the compressed fluid source 14 can be reduced and / or adjusted. A measuring mechanism 50 is also arranged in the actuation device 30 and can determine the piston position and therefore also detect changes in the piston stroke s. The measuring mechanism 50 is connected to the control mechanism 40, which is connected to the proportional valve mechanism 60 via a data line 41 for data and / or signal exchange. Using the control mechanism 40, the measured values ​​of the measuring mechanism 50 are evaluated with respect to the piston position and / or piston stroke, and a comparison of target and actual values ​​is performed, for example, by the control mechanism 40. The proportional valve mechanism 60 can be electrically controlled by the control mechanism 40, so that, if necessary, the volumetric flow rate of the compressed fluid H supplied to the cylinder casing 33 of the actuation mechanism 30 can be changed to change the opening / closing behavior of the check valve mechanism 20.

[0034] FIG. 3 shows the proportional valve mechanism 60 in its single position. The proportional valve mechanism 60 is configured as a 4 / 4 proportional valve and therefore has four valve connections A, B, P, and T for supplying and / or discharging compressed fluid H. The valve connections are labeled T for tank, P for pressure, and A and B for consumption. In particular, the volumetric flow rate of compressed fluid H supplied from the proportional valve mechanism 60 to the actuation mechanism 30, particularly the cylinder casing 33, can be precisely controlled through different positions of the valve piston 61 by the continuous switching behavior of the proportional valve mechanism 60. This switching behavior is made possible by a magnet 63 and a coil 64 that are electrically controllable and thus capable of moving the valve piston 61 to different valve piston positions. As can be seen in FIG. 3, the magnet 63 is arranged on a shared shaft 67 together with the valve piston 61. The magnets 63 are arranged at both ends of the shaft 67 and, in the illustrated embodiment, are subjected to horizontal forces via controllable coils 64, which in turn cause the shaft 67 to move in the direction of axial movement V together with the valve piston 61, which is arranged in a fixed position on the shaft 67. Supplying a current to the coils 64, which interact with the magnets 63, causes the shaft 67 to move, since the magnets 63 and the valve piston 61 are stationary on the shaft 67. When no current is applied to the coils 64, the magnets 63 can return to their home position via one of the valve springs 66, and the valve connections A and B, which lead to the consumer side (not shown here), are closed in their home position. The home position is shown in FIG. 3. In the end positions, i.e., with the valve piston 61 at its maximum deflection, the different valve connections A, B, P, and T are connected to one another. As shown in the rightmost position, the valve connection T is connected to the valve connection A, and the valve connection P is connected to the valve connection B. In the leftmost position, valve connection T is connected to valve connection B and valve connection P is connected to valve connection A. An electrical current for moving shaft 67 can be supplied through electrical connection 62. Control mechanism 40 (not shown here) is configured to control the electrical current supplied to proportional valve mechanism 60 and thereby control the opening behavior of check valve mechanism 20.The supply of compressed fluid H to the hydraulic cylinder 31 (not shown in Figure 3) of the actuation mechanism 30, which interacts with the check valve device 20 to operate it, allows for an adjustable opening behavior of the check valve device 20, which ensures a more efficient use of compressed air. [Explanation of symbols]

[0035] 10 Valve device 11 Consumer side 12 Pressure control device 13 Compressed air source 14 Compressed fluid source 20. Check valve mechanism 21 Valve rod 22 Closure elements 23 Check valve casing 24 Valve seat 25 Connection joint 30 Operating mechanism 31 Hydraulic cylinder 32 piston 33 Cylinder casing 34 Piston rod 34a front 35 Stopping Elements 35b Stop Damper 36 Expansion spring 37 Support collar 38 Passage 39 Hydraulic piping 40 Control Mechanism 41 Data line 50 Measuring mechanism 60 Proportional valve mechanism 61 Valve piston 62 Electrical Connections 63 Magnet 64 coils 66 valve spring 67 axes 70 Molding machine 71 Molding materials 72 Mold flask 73 Model 74 Compression mechanism 75 Air outlet A, B, P, T valve connections D Compressed air flow H Compressed fluid s Piston stroke V axial movement

Claims

1. A valve device (10) having a check valve mechanism (20) with a valve rod (21) and a closing element (22) arranged at one end of the valve rod (21) and intended for supplying compressed air to a consumer side (11), The valve device further includes an actuating mechanism (30) having a hydraulic cylinder (31), a piston (32) of the hydraulic cylinder (31) being rigidly connected to the valve rod (21) and hydraulically driven within a cylinder casing (33) of the hydraulic cylinder (31) to actuate the check valve mechanism (20), 1. A valve device (10) comprising a control mechanism (40) for controlling piston movement and a measurement mechanism (50) for detecting piston position, the proportional valve mechanism (60) being controllable by the control mechanism (40) as a function of piston position and connected in fluid communication to the hydraulic cylinder (31).

2. 2. The valve arrangement according to claim 1, characterized in that the measuring mechanism (50) comprises a laser triangulation sensor and / or a touchless path sensor, preferably a magnetostrictive path sensor, and / or an ultrasonic distance sensor, for detecting the piston position.

3. 3. The valve arrangement according to claim 1 or 2, characterized in that the proportional valve mechanism (60) is configured as a 4 / 4 proportional valve.

4. 4. The valve device according to claim 1, wherein the valve piston (61) of the proportional valve mechanism (60) is displaceable by current control.

5. 5. The valve arrangement according to any one of claims 1 to 4, characterized in that the control mechanism (40) comprises a PID controller.

6. 6. A valve device according to any one of claims 1 to 5, characterized in that the piston (32) is double-acting.

7. 7. The valve device according to claim 1, wherein a piston rod (34) is arranged on the piston (32) opposite the valve rod (21) and flush with the axis of the valve rod, and the valve rod (21) and the piston rod (34) have different diameters.

8. 8. Valve arrangement according to any one of claims 1 to 7, characterized in that the movement (s) of the piston (32) is limited by a stationary, preferably adjustable, stop element (35).

9. 9. The valve device according to claim 1, wherein a piston rod (34) is arranged on the piston (32) opposite the valve rod (21) and flush with the axis of the valve rod, and a free front face (34a) of the piston rod (34) facing away from the closure element (21) abuts against a stop element (35).

10. 10. The valve device according to claim 9, characterized in that a stop damper (35b) is provided on the free front face (34a) of the piston rod (32) and / or on the stop element (35).

11. 11. The valve device according to claim 1, wherein a fixed return spring (36) is arranged so that when the check valve mechanism (20) is opened, the valve rod (21) is moved against the spring force of the return spring (36).

12. 12. A valve arrangement according to any one of claims 1 to 11, characterized in that the adjustable pressure control mechanism (12) is arranged upstream of the proportional valve element (60).

13. 13. A molding machine (70) for compressing a molding material (71), comprising a flask (72) that can be filled with the molding material (71), wherein a pattern (73) is placed in the flask (72), and the flask (72) is connected to a compressed air supply (D), the molding machine (70) further comprising a valve device (10) for releasing the compressed air supply (D) to the flask (72) according to any one of claims 1 to 12, wherein a mold is formed by compressing the molding material (71) after it has been subjected to pressure.

14. 1. A method for controlling a valve device (10) having a check valve mechanism (20) with a valve rod (21) and a closing element (21) arranged on one end of the valve rod (21) and intended for supplying compressed air (D) to a consumption side (11), wherein the valve device (10) further comprises an actuation mechanism (30) having a hydraulic cylinder (31), a piston (32) of which is rigidly connected to the valve rod (21) and hydraulically driven in a cylinder casing (33) of the hydraulic cylinder (31) to actuate the check valve mechanism (20), a piston position being determined using a measurement mechanism (50), and piston movement being controlled as a function of the determined piston position by a proportional valve mechanism (60) connected in fluid communication with the hydraulic cylinder, so as to vary a volumetric flow rate of hydraulic oil (H) supplied to the hydraulic cylinder (31).

15. 15. The method according to claim 14, wherein the piston position and / or piston stroke are determined at regular time intervals using the measuring mechanism (50) and transmitted as actual values ​​to the control device (40), the actual values ​​are compared with target values ​​using a control mechanism (40), and if the target values ​​and the actual values ​​differ, the control signal issued to control the proportional valve mechanism (60) is modified using the control mechanism (40).

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