EP0935262A2 - Electromagnet - Google Patents

Abstract

Electromagnet comprises a spool which produces a magnetic field and moves a core when supplied with an electric current. The core is used to control a valve or other element and its movement is damped by damping elements. The core (11) moves on a plastic sliding surface (2), especially a plastic film.

Description

The invention relates to an electromagnet consisting of a coil to which current can be applied, which is such a magnetic field generated and moved an armature when current was applied, and the armature for driving a valve or one serves other element, the movement of the armature of one or more damping elements is damped.

The aforementioned electromagnets have one in the field of technology widely used. They are used, for example, in textile machines for a quick weft insertion of the threads.

The electromagnets described above are also used for Control of gaseous and liquid media (especially in Liquid or hydraulic circuits), for example in one Valve or as an actuating or lifting magnet for lifetime and time-critical applications.

Especially the area of application in weaving machines or other Textile machines require high performance from Electromagnets. It is expected that the electromagnet achieve the highest service life requirements and switching frequencies. This results in considerable mechanical loads for the electromagnet and the movably mounted elements.

In the German patent 31 32 396 there is an electromagnet described the elastic elements as a damping body uses the kinetic energy of the anchor and thus prevents premature wear of the electromagnet.

To achieve the high clock frequencies, corresponding Accelerations of the armature can be achieved. A special The bearing of the armature is important because it is inaccurate Storage of the anchor to one-sided loading of the Damping elements can lead, which is then preferred at these points wear out and then the entire usability of the Device at risk.

Due to the high frequencies, the heat development is also Solenoid remarkable. This leads to design reasons larger air gaps to constructively the thermal expansion of the Components to take into account. But this affects on the other hand the effective magnetic gaps and reduced thus the efficiency of the device.

The invention has set itself the task of electromagnets described in the introduction to improve that this one longer average lifespan or higher efficiency to have.

To achieve this object, the invention is based on one Electromagnets as described at the beginning and suggests that the anchor on a plastic sliding surface, especially one Plastic slide film is running. By using a The problem of thermal expansion is skilfully solved since the inserted film due to the low mechanical Low thermal coupling to the other device experiences and thus a smaller constructive air gaps necessary is. It has also been found that the foil storage serves an exact and low-wear mounting of the anchor, thus optimal lateral forces or inclinations of the anchor be balanced, resulting in a relatively uniform Strain of the damping elements leads. This will the one-sided wear of the damping elements avoided, which ensures high reliability and durability of the electromagnet results.

The foil storage has proven to be particularly wear-resistant. The thin-walled film saves installation space without thereby impairing the mechanical reliability or stability. Small and relatively precisely definable bearing gaps reduces the air gap in the magnetic transition, which improves the magnetic properties of the magnet become and thus the efficiency is increased. There is also an advantage in the manufacture of the Device. In the known anchor guides, the anchor runs open the inside surface of a pipe. This tube is for example originated from a hole in a solid material. For one It was necessary to anchor the hole as precisely as possible the pipe as precisely as possible. This high effort will saved by the proposal according to the invention. There are not any increased requirements regarding the surface quality of the Tube to take into account more because this task of the plastic tread, especially of the inserted film, is taken over. The solution according to the invention thus leads to a less expensive structure and easier assembly of the device.

In addition to using a plastic film, it is also possible to the anchor on a suitably designed plastic surface to let it slide. This surface takes over here the task of the slide.

Another advantage of the configuration according to the invention lies especially in the possibility of a corresponding Varying the thickness of the film Dimensional tolerances during production to compensate for the electromagnet. So far, magnets that have too large a dimensional tolerance, automatically one Reject piece because the air gaps are too large the efficiency or limited efficiency of this device and thus this device can no longer be used for certain applications was. Because the movable anchor on a plastic sliding surface slides, the thickness of this surface can be adjusted so that optimal conditions prevail. When testing the devices can thus be made by an appropriate choice of film thickness Dimensional tolerances in production are compensated for. This Preference is also repeated when the devices are overhauled. Is due to the long service life of the device, especially on the moving parts, worn out, can be replaced by a corresponding one Exchange of these moving parts and the interacting parts Plastic sliding surface and possibly one thicker sliding surface, the device simple and inexpensive be overhauled and restored. The one from it resulting benefits in reusability and Recyclability of the complex devices is obvious.

In addition to using a plastic sheet, for example provided in the known anchor guide one made of special Insert plastic-made socket on the Inner surface of the anchor slides. Another variant is a plastic coating on the armature facing Inner surface of the anchor guide possible.

The use of the plastic film ensures that the Foil can be removed more easily, especially if the Anchor can be easily removed from the core. In the event that the Foil is worn out, it can be easily replaced and the device can be made operational again.

In a preferred embodiment of the invention is a modular structure of the electromagnet provided, for the Anchor with the anchor guide and the coil each have their own assembly are provided, which are releasably connected together. Such a configuration makes it easier and less expensive Construction or assembly of the electromagnet achieved. It is also possible to easily maintain the electromagnet to be carried out, since the corresponding modules can be replaced if necessary are. A detachable connection can, for example, by a corresponding screw or clamp connection is reached become. This not only results in an advantage in the Assembly or when building the electromagnet, but it will also achieved an advantage in operating the device. Through the separate design will be largely thermal Decoupling of the electromagnet or the coil on the one hand and the armature assembly on the other hand. Because the heat conduction essentially through direct contact between these two Assemblies can be made by waiving or reducing a direct connection reduces the thermal contact be, whereby the thermal problems, especially in the described high frequencies are significantly suppressed can, leading to an increase in the reliability of the device leads. Alternatively, it is also possible to use the device to build as an inseparable unit. Here, the Example of solid, permanent connections. The assemblies to be interconnected become the Example welded together or caulked mechanically. It can also be a common plastic potting or the like be provided to the assemblies firmly together connect.

Another advantage is achieved when using the anchor assembly a control element, for example for a valve is. In connection with the modular structure of the invention the control element, for example for a Valve or for another mechanically designed Element combined with the armature assembly. Through the Interchangeability can be different with the coil assembly dimensioned armature and / or control elements together Act. With a small number of modules, a further one can Applications of these electromagnets are covered.

Damping elements are provided for the movement of the armature, the damping elements either on the moving Anchor or at paragraphs of the anchor guide, essentially stationary, are arranged. Optimal damping is achieved by relatively large and / or large-volume damping elements reached. By appropriate choice of damping elements, especially with regard to the material of the surfaces and the Volume of the damping element, it is possible to wear characteristics of the device. Here is also note that the selection of the elastic damping element, in combination with the foil storage or the design the plastic sliding surface of the anchor further parameters results from the wear parameters or other requirements can be set specifically.

It is advantageous if the function of the damping element is combined with a sealing function, in particular if the damping element as a sealing plate for the closure serves a valve opening. Through the double functionality the damping element is proportionate to the small devices construction volume saved.

It has proven to be advantageous if the armature tread or the slide film is made of polytetrafluorethylene (PTFE). This material is characterized by a very low adhesion, that is, a contact or stickiness. Surfaces or Slide films made of such a material act like a "ball bearing". These areas allow you smooth running of the moving part. By reducing the mechanical resistances, i.e. the frictional resistances the achievable accelerations and thus the achievable switching times influenced favorably. At the same time the film is only slightly applied, which saves construction volume is and due to the low specific weight also Weight percentage for storage is very low.

Further advantageous embodiments of the invention are in the Subclaims described or in the accompanying drawing shown.

Fig. 1, 2, 4 und 5

ein vertikaler Schnitt durch verschiedene Ausführungsformen des erfindungsgemäßen Elektromagneten und

Fig. 3

ein vergrößertes Detail gemäß III aus Fig. 1.

The invention is shown schematically in the drawing. Show it;

1, 2, 4 and 5

a vertical section through various embodiments of the electromagnet according to the invention and

Fig. 3

2 shows an enlarged detail according to III from FIG. 1.

In Fig. 1 the electromagnet according to the invention is schematic shown.

Due to the modular structure, there is an anchor assembly 1 and a coil assembly 3.

The coil assembly 3 in this case comprises the coil body 30, the that carries wire windings. The coil 30 is with electrical Contacts 34 with a corresponding electrical power supply connected. The winding is on a bobbin 33 wound, the coil body 33 is substantially rotationally symmetrical to the coil axis 31 is provided.

The modular structure also applies to the coil assembly away. The coil 30, which is covered with a plastic casing 35 is surrounded, is essentially in the bracket 32 inserted at right angles to the coil axis 31. The bracket 32 has an opening for each on the two legs the implementation of the coil assembly 3. The coil 30 is thus easy to detach from the bracket 32. The bracket 32 serves e.g. of the Attachment. In a variant, the bracket 32 can also be of a Be surrounded by plastic sheathing.

The coil assembly 3 is through the connection 4 with the Armature assembly 1 connected. As connection 4 is for example a clamping ring 40 is provided. But this can also be used as a screw connection 41 (FIG. 5). As a connection here in particular a detachable connection is provided. This ensures that the armature assembly 1 and the coil assembly 3 can also be easily disassembled for Example if the device needs to be repaired or overhauled.

The armature assembly 1 also consists of several elements. On the armature assembly 1, the tube tube 10 is provided, which Can be inserted coaxially to the coil axis 31 in the coil assembly 3 is. The tube tube 10 is here by the corresponding Bores of the bracket 32 in the previously inserted in this bracket Coil assembly 3 introduced.

The tube tube 10 has the core 12 at its upper end, which is a magnetic guidance of the magnetic field, which by the coil 30 is generated offers. The core 12 protrudes the inside of the coil 30.

The tube tube 10 serves to guide the armature 11. The armature 11 does not run directly on the inner wall of the tube 10, but as shown in Fig. 1 example on a sliding surface 2 or a slide film 20. This is enlarged in Fig. 3 shown. The tube tube 10 is in this case on the core 12 put on and caulked or welded. At the bottom, inner area of the core 12 is in the outer surface Circumferential gap 17 (Fig. 3) provided by simple Twisting the core 12 was generated.

The film 20 projects into the gap 17. By a certain Jamming the film 20 in the gap is kept on the circumference. The film is made of polytetrafluorethylene and causes smooth movement of the movable anchor body 15 on the inner surface of the tube 10. In addition to use a film 20, it is also possible to cover the inner surface of the tube either made from a suitable plastic or an appropriate coating on the Apply tube tube. The use of the film is so far easy because the film is light in different thicknesses can be manufactured and assembled in the appropriate dimensions can be. By clamping the film in the gap 17 it is also kept reliably. Because the leadership role provided by the film must now for the inner surface quality the tube tube no longer met increased requirements be, which increases the cost of producing the Significantly reduce the size of the tubes because the tube has a simpler Tool can be edited and in particular a subsequent one Surface treatment, for example grinding or Polishing is no longer necessary.

According to the embodiment shown in Fig. 1 was in the Coil body 30 is a separate element, the tube 10 used, which is the task of guiding the anchor took over. The proposal according to the invention Sliding film arrangement is also with electromagnets can be used in which the coil body inside a Has recess and at the same time as a tread for the Serves anchor. In particular with such configurations, the Invention may be advantageous because of the introduction of the tube in addition to the better magnetic guidance also more precise can be produced. The use of the slide film can also do this exploited, manufacturing-related inaccuracies in the Compensate bore in the coil. In this variant of Invention is thus an additional, proportionate elaborate and precisely manufactured element, namely that Tube tube, saved and by the invention Design replaced, and a smooth and at the same time get wear-resistant electromagnet. This results in an advantageous embodiment of the invention such that the Plastic sliding surface on the tube tube and / or the Coil body or the bore provided in the coil body is. It is also possible that the tube tube 10 does not cover the whole Arrange the length of the bobbin or its bore and the Sections of the anchor either through the tube or the To guide the bobbin. Between the anchor body and the The tube tube or the coil body is the plastic sliding surface for example in the form of a coating of a separate one Element or a film provided.

The operation of the electromagnet according to the invention is in essential as follows:

The magnetic field generated by the coil 30 moves the movable one Anchor 11 or anchor body 15 usually against the Force of a return spring 14 such that the air gap 13 at Actuation of the coil 30 is closed. Through the hub corresponding to the air gap 13 can be connected to it Device, for example a valve or other element controlled, opened or moved accordingly. Will the When current is switched off by the coil 30, the magnetic field drops together, making the magnetic attraction less are like the spring force of the return fields 14 and the return spring 14 presses anchor again away from the core 12 in such a way that there is an air gap 13.

The movement of the armature 11 or the armature body 15 is limited in particular by damping elements 6.

The anchor body 15 has a flange in its lower part 18. This flange 18 works together with a damping element 6, which connects above the flange 18. The Damping element 6 surrounds armature 11 in a ring. The damping element 6 is preferably fixed, moves not with the armature 11, so that the moving mass is not increase unnecessarily. But it is also possible that Damping element 6 movable with the armature 11 and the To design anchor body 15. This is especially true of Advantage if a by the movement of the damping element 6 additional function, for example a sealing function, should be triggered. Through the damping element kinetic energy of the anchor, which is directed upwards, in Interaction with the ring plate caught. The ring plate 19 connects the tube 10 to which it is connected is integrally formed with the valve body 7. For this purpose Screws 73 are provided. The valve body 7 has in its upper, directed towards the tube tube 10 in inner area a recess which is designed such that the damping element 6 can be accommodated. Is limited this recess 74 from the ring plate 19.

To dampen the kinetic energy of the armature 11, which after is directed at the bottom end of the anchor 11 a damping element 6 embedded in the anchor, which as Sealing plate 60 acts. 1 is the closed one Position of an electromagnetic valve shown, the sealing plate 60 finally with the sealing surface 75 at the outlet opening 71 of the valve body 7 cooperates. This will the inlet opening 70 is separated from the outlet opening 71 and interrupted. Are on the outside of the valve body 7 Seals 72 provided to the solenoid valve on the Media circuit (for example liquid circuit), the is switched and controlled, tightly connect and to involve.

It has been found in an advantageous manner that the configuration according to the invention, also with regard to different media, for a long service life of the device and a corresponding reliability with high efficiency has led.

It is known that dried air is often abrasive to the Storage works and leads to preferred wear. Also the use in oil sludge is possibly for the life of the device disadvantageous. Now, by using the Plastic tread or the slide film have been found that reliable even in a wide variety of operating media function.

2 shows another embodiment of the invention Electromagnet shown. In Fig. 1 is through the valve body a hydraulic or pneumatic arrangement switched in Fig. 2 provides that the anchor rod 16, which with the Anchor 11 or the anchor body 15 is connected, a corresponding Movement to an element not shown transmits. Such an electromagnet can e.g. in textile machines be used. For the rest, the structure is essentially identical to the structure according to FIG. 1.

It should be noted that the damping elements 6 each are not designed to move with the anchor body 15, but are designed to be essentially fixed. Of the Flange 18 of the anchor body 15 runs against the upper one and lower damping element 6. Again in assembly 9, which also forms a guide 90 for the anchor rod 16, one Recess 91 is provided in which the flange 18 up and down emotional. The guide 90 is in this case in an anchor rod guide 8 provided and is located at the lower end of the electromagnet. In a variant of the invention it is of course also possible that the damping element with the anchor body 15th moved along. The movement of the armature 11 is determined by the Damping elements 6 added, with other elements of Electromagnets, especially elements related to the coil group 3 are connected, serve as abutments and a part compensate for the kinetic energy.

The upper damping element 6 serves here as the attachment of the Foil 20 such that after the foil 20 is inserted into the tube is, the film in the recess 91 radially outwards is pulled and by the axially pushed damping element 6 is clamped.

The damping element 6 and the sealing plate 60 are made suitable, elastic plastic formed. By choice of these materials and the choice of the quality of the slide film 20 or the thickness of the sliding film 20, it is possible to determine the wear parameters of the electromagnet or the smoothness or the Set the service life according to the purpose.

1 and 2, the return spring 14 is in the region of the air gap 13 arranged. It can also be provided that the Storage of the return spring 14 with additional damping elements Is provided.

4 shows a further variant of the invention. The anchor rod 16 is guided in the core 12. With a suit the anchor 11, the anchor rod 16 is shifted to the right, the air gap 13 is closed. In contrast to 2 takes place here when current is applied stepping out of the anchor rod 16 in FIG. 2 Pulling the anchor rod 16 into the electromagnet.

Here, too, the other structure is identical to that in the example 1, 2. That is, the tube 10 is part of the Armature assembly 1 equipped with an inner slide 2. The anchor 11 or the slides on the slide film 2 Anchor body 15. To improve the sliding properties, the anchor body 15 has a plurality of slide rings 25. The slide rings consist of a bronze alloy on the Anchor body 15 are welded or applied.

The tube tube 10 is in the area of the air gap 13 by a annular tube element 26 interrupted, which consists of a other material can exist. Through the variation of magnetizable, ferromagnetic or non-magnetic materials in this area the switching characteristics of the Magnets are influenced accordingly. The ring-shaped tube element 26 is used in the manufacture of the tube in this incorporated, e.g. soldered or welded and afterwards turned off.

5 is another example of the invention Magnets shown. Here an electromagnet is presented, in the same way as the examples according to FIGS. 1, 2 and 4 is constructed. It is a valve magnet which in turn by a sealing plate 60, which is also called Damping element 6 is used, a valve opening closed or is opened. This magnet is also modular, that That is, the armature assembly 1 is simple from the coil assembly 3 detachably arranged. This is done e.g. through the lanyards 4, 41, which here as nuts with internal or external threads.

The claims now filed with the application and later are attempts to formulate without prejudice to achieve further protection.

The backward relationships mentioned in the dependent claims point to the further training of the subject of the main claim by the features of the respective subclaim there. However, these are not considered a waiver of achievement an independent, objective protection for the characteristics to understand the related subclaims.

Features previously only disclosed in the description can in the course of the process as of essential to the invention Significance, for example to differentiate it from the prior art be claimed.

Claims (11)

Electromagnet consisting of a pressurizable with current coil which generates such a magnetic field and moves an armature when current and the armature for the actuation of a valve or other element is used, wherein the movement of the armature is damped by one or more damping elements, characterized characterized in that the armature (11) runs on a plastic sliding surface (2), in particular a sliding film (20) made of plastic. Electromagnet according to claim 1, characterized by a modular structure, wherein for the armature (11) with the armature guide and the coil (30) each have its own assembly (1, 3) which are detachably connected to one another. Electromagnet according to one or both of the preceding claims, characterized in that the armature assembly (1) essentially consists of a tube tube (10) in which the armature (11) is movably mounted. Electromagnet according to one or more of the preceding claims, characterized in that the armature assembly (1) with the tube tube (10) can be inserted coaxially to the coil axis (31) of the magnet coil (30) into the coil assembly (3) and by a screw or clamp connection (4, 40, 41) can be fastened. Electromagnet according to one or more of the preceding claims, characterized in that the armature assembly (1) is connected to a control element (7), for example for a valve. Electromagnet according to one or more of the preceding claims, characterized in that damping elements (6) are provided for damping the movement of the armature (11) on the armature (11) and / or on one or more shoulders (91, 74) of the armature guide . Electromagnet according to one or more of the preceding claims, characterized in that the damping element (6) arranged on the armature (11) serves as a sealing plate (60) for closing a valve opening (70, 71). Electromagnet according to one or more of the preceding claims, characterized in that the armature (11) has slide rings (25) which interact with the armature guide. Electromagnet according to one or more of the preceding claims, characterized in that the armature running surface (2) or the sliding film (20) consists of polytetrafluorethylene (PTFE). Electromagnet according to one or more of the preceding claims, characterized in that the plastic sliding surface (2) is provided on the tube tube and / or the coil body or the bore in the coil body. Electromagnet according to one or more of the preceding claims, characterized in that the damping element (6) is designed to be fixed or movable with respect to the armature (11).

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