WO2014032761A1

WO2014032761A1 - Valve for flowable media, in particular glue valve, and method for producing the valve

Info

Publication number: WO2014032761A1
Application number: PCT/EP2013/002376
Authority: WO
Inventors: Reinhard Hoppe; Nils Neuhaus; Jan-Christian WALTER
Original assignee: Focke & Co. (Gmbh & Co. Kg)
Priority date: 2012-08-27
Filing date: 2013-08-08
Publication date: 2014-03-06
Also published as: DE102012016833A1

Abstract

The invention relates to a valve for flowable media, in particular a glue valve, comprising at least one electromagnet by means of which a shutting element (19) of the valve (10) can be displaced and by means of which heat can be accurately transferred onto the flowable medium, preferably hot glue, the at least one electromagnet having at least one coil (14) arranged on a coil support (15) which at least partially surrounds the shutting element (19). The invention is characterised in that the entire coil support (19), at least the region (16) of the coil support (15) against which windings of the coil (14) immediately lie, consists of an injection-mouldable, ceramic substance of high thermal conductivity of at least 15 Wm^-1K^-1, particularly preferably of silicon nitride. The invention further relates to a method for producing such a valve.

Description

Valve for flowable media, in particular glue valve, and method for producing the valve

description

The invention relates to a valve for flowable media, in particular a glue valve, with the features of the preamble of claim 1. Furthermore, the invention relates to a method for producing such (glue) valves having the features of the preamble of claim 10.

A glue valve having the aforementioned features is shown and described for example in DE 10 2010 034 761. A closure member, namely a valve stem, is in this case surrounded by two (electric) coils, which are arranged on a common coil carrier or bobbin. The unit of coils and bobbin is housed in a valve housing. The coil carrier consists of high quality plastic with fiber reinforcement. Each coil is part of one of a total of two electromagnets, with which the closure member is movable. The waste heat of the coils is selectively transferred to the (hot) glue inside the valve chamber.

It is an object of the present invention to further develop such glue valves. The same applies to the production of such glue valves. To achieve this object, the valve according to the invention has the features of claim 1. A method of manufacturing such a valve is described by the features of claim 10.

A special feature of the valve according to the invention is therefore that the entire bobbin, but at least the area of the bobbin on which lie directly the turns of the at least one coil, from a

CONFIRMATION COPY injection-moldable, ceramic material with a high thermal conductivity of at least 15 Wm ^'1 K ^"1. It has surprisingly been found that the use of such a ceramic material is associated with particular advantages.

On the one hand, the ceramic material of such high thermal conductivity ensures that the thermal energy generated by the at least one coil of the electromagnet is passed on particularly well during operation and transferred to the flowable medium. At the same time it is ensured by the use of ceramic that the coil carrier is an electrical insulator, so that the turns of the at least one coil can be wound directly onto the bobbin without the risk of electrical short circuits. Furthermore, by virtue of the selected ceramic being injection-moldable, it is possible to produce the coil carriers inexpensively by means of conventional injection molding methods. The temperature resistance of ceramics finally ensures a long service life.

According to a further special feature of the invention, the coil carrier is arranged in a housing chamber or in an interior of the valve, between at least one of the housing chamber adjacent housing chamber wall and the at least one coil and / or the coil carrier initially during assembly of the valve, a free space is available , which is filled before the completion of the valve with a thermally conductive potting compound.

In this case, the potting compound comes into contact, in particular, with the outside of the at least one coil running parallel to the coil axis, and then preferably penetrates further inwardly through spaces / channels between the turns of the at least one coil in the direction of the coil axis, in particular to the coil carrier.

The potting compound ensures a particularly good distribution of the resulting heat. Local heat peaks are avoided. As a result, a uniform heat transfer to the flowable medium is possible. Prefers For example, the potting compound has a thermal conductivity value of between 0.5 μm ^" ¹ K ¹ and 2.0 μm ^{" 1} K ^"1. The potting compound used can be, for example, a crosslinked organic polymer, for example one or more epoxides.

In a further embodiment of the invention, the valve preferably has two detachably interconnected or connectable modules, namely a valve unit in which, inter alia, the closure member, the at least one coil and the coil carrier are arranged, and a supply unit, in which at least one connection for a supply line for the flowable medium is arranged, in particular for a hose, and a supply for power and / or control lines.

The valve unit preferably has a plug part, from which current and / or control lines are led to at least one electrical component of the valve unit, preferably to the at least one coil. The plug part is then plugged in the assembly of the valve in a matching plug part of the supply unit, are guided by the power and / or control lines to the supply of the supply unit.

In the context of the method according to the invention for producing a valve described above, the coil carrier is preferably first injection molded from the injection-moldable, ceramic material with the high thermal conductivity. Subsequently, the at least one coil of the electromagnet is wound onto the injection-molded coil carrier.

During assembly of the individual valve components necessary for the valve, the coil carrier together with the at least one coil is then arranged in the above-mentioned valve housing chamber.

Through a filling channel, which is guided from the valve housing chamber to the outside of an (outer) wall of the valve housing, the above-described space area between the at least one, the valve housing chamber bounding chamber wall and the at least a coil and / or the coil carrier filled from the outside with the potting compound.

Preferably, the filled unit is spent after the filling under vacuum in order to outgas any air pockets in the potting compound. Such air influences would hinder the heat transfer in the potting compound and thus the heat distribution.

Further features of the present invention will become apparent from the appended claims, the following description of a preferred embodiment of the invention, as well as from the accompanying drawings. It shows:

Fig. 1 is a plan view of an inventive, fully assembled

Glue valve with valve unit and supply unit,

Fig. 2 is a vertical section through the glue valve of Fig. 1 along the

Section II-II, Figure 3 shows the valve unit as shown in FIG. 2 in a phase before the completion of the valve.

Fig. 4 is a section taken along section line IV-IV of Fig. 2. The glue valve 10 shown in the drawings is preferably used to transfer relatively small sized glue portions to flaps of packages such as cigarette packs. It is designed for high cycle rates.

The glue valve 10 comprises a valve unit 11 with a valve housing 11 a and a supply unit 12 with supply housing 12 a. Valve unit 1 1 and supply unit 12 are connected to each other by attaching the valve housing 1 1a to the supply housing 12a. Within the valve housing 1 1a, namely in a valve housing interior or a valve housing chamber 13, two coils 14 of two electromagnets are arranged in the present case. Each solenoid has in each case one coil 14. Basically, only one electromagnet with one or more coils or more than two electromagnets, each with one or more coils could be used.

The two coils 14 are both wound on a common bobbin or bobbin 15 in the present embodiment. They are not shown separately or individually.

In the present case, in the area in which the windings of the coils 14 are arranged, the coil carrier 15 has a tubular or hollow cylindrical section 16 with a correspondingly cylindrical outer side 17.

The hollow cylindrical portion 16 of the bobbin 15 surrounds a corresponding cylindrical interior 18. Within the interior 18, a closure or metering member 19 of the valve 10 is movably arranged, namely a valve tappet.

On a lower shaft 20 of the closure member 19, a ball 21 as a closure means for a metering or valve opening 22 is attached. The valve opening 22 is arranged centrally in the region of a funnel-shaped valve seat or in the region of a valve nozzle 23. The ball 21 is in the closed position of the valve 10 shown in FIG. 2 on conical seating surfaces of the valve nozzle 23 and closes the valve opening 22nd

About a arranged on the supply housing 12a, designed as a hose connection 24 glue connection of the supply unit 12 can be supplied to the glue valve 10 to be metered glue, in this case hot glue, via a heated hose 25 from a glue source, not shown. From the hose connection 24, the glue in the supply housing 12a is first guided along a first glue channel 26 of the glue valve 10 via a filter 27. After flowing through the filter 27, the glue is conducted via a second glue channel 28 into the valve housing 11a and flows from there into the space 18 of the valve 10 surrounded by the coil carrier 15 and then in the direction of the nozzle 23 or valve opening 22.

The inside of the valve nozzle 23 limited space forms together with the interior 18 and adjacent connecting portions of the actual valve chamber of the valve 10, in which the glue to be applied is during operation.

The closure member 19 is opened by suitable loading of the electromagnets with electric current, so that glue can escape via the valve opening 22 from the valve chamber.

For this purpose, arranged on the common coil carrier 15 coils 14 of the electromagnet surround the closure member 19 at least in sections. In the present case, a metallic guide piece 29 of the closure element 19 connected to the valve body 20 is arranged above the shaft 20 of the closure element 19 in the region of the interior space 18 surrounded by the coil carrier 15 and the coils 14.

The metallic guide piece 29 acts within the coils 14 as the core of the electromagnets of the valve 10. In a suitable, later described in detail power supply to the coil 14, these transfer a resultant magnetic force or an opening force on the guide piece 29. As a result, the closure member 19, and with it the ball 21, a total of the closed position shown in Fig. 1 in a valve opening 22 releasing opening position moves, in which the glue can escape from the valve opening 22.

The closure member 19 is preferably permanently urged in the closed position in the closed position by a closing means or closing member. This is formed in the present embodiment as a two-repelling individual magnets comprehensive permanent magnet (not shown), which exerts a permanent, resulting magnetic force on the closure member 19 in the sense of a closing movement. Of course, other suitable closure forces performing closing means may be used, such as (return springs or the like.

The one single magnet of the permanent magnet is firmly connected to the valve housing 11a. In the present case, this individual magnet is attached for this purpose in the lower end region of a bolt-like magnet holder 30, in a suitable recess in the region of the guide piece 29 facing end surface. The bolt-like magnet holder 30 in turn has an upper threaded projection 35, which is bolted to a screwed into a thread 46 on the valve housing 11a lock nut 38 and is thus firmly connected to the valve housing 11a. The threaded extension 35 has a suitable adjusting recess, such as a (inner) hexagonal recess, or a suitable adjusting lug. With an appropriately adjusted adjusting tool, such as a matching (internal) hex key, then the axial position or the height of the threaded extension 35 and with it the entire magnet holder 30 can be adjusted. Accordingly, the valve lift is adjusted or adjusted in this way.

The other single magnet of the permanent magnet is mounted opposite to the closure member 19, in a recess on the bolt-like magnet holder 30 facing end surface of the guide piece 29. The individual magnets have a (small) distance from each other even when the glue valve is open. The two individual magnets are positioned so that the same poles face each other, for example the north pole. Due to the repulsive force between the permanent individual magnets a repulsive force is permanently transmitted to the closure member 19, so that it is acted upon in the closed position with a corresponding closing force. The opening force caused by the electromagnets described above, which acts on the closure member 19 and the guide piece 29, then overcomes this permanent closing force.

The windings of the coils or the windings are - as already mentioned - wound on the bobbin 17 and on the hollow cylindrical portion 16 thereof. In the present case, windings of one coil 14 and turns of the other coil 14 follow one another alternately in the vertical or in the axial direction of the bobbin 17. In this case, the turns are in the first Wirtdungslage in which the individual windings lie directly on the bobbin 7, and in all other, following in the radial direction of winding layers in each case alternately (relative to the axial direction) side by side. The type of winding or the arrangement of the two coils 14 can also be done differently. It is important to wind the coils 14 on the common bobbin 15 so that in operation, the effects described in more detail below can be achieved.

Both electromagnets or both coils 14 are acted upon during operation either with current in the same direction or with current in the opposite direction. In this case, the current intensities are preferably identical in absolute terms in each case.

By applying current with current of opposite direction, the coils 14 arranged in the manner described above or in an equivalent manner generate in the interior of the coil or in the interior surrounded by the coil support 15

18 preferably equal magnetic fields in opposite axial directions.

In other words, the magnetic fields of the two electromagnets cancel each other inside the coils 14. On the guide piece 29 and the closure member

Accordingly, no magnetic forces are exerted by the electromagnets in this type of current application, so that the closure member 19 remains in its closed position caused by the individual permanent magnets. However, due to the flow of current, the coils 14 generate heat, which is given off at the glue located in the inner space 18 and serves to heat it.

When current is applied to the current in the same direction, the electromagnets generate magnetic fields in the same direction, so that a resultant magnetic force (opening force) is exerted on the guide piece 29, which counteracts the closing force exerted by the individual magnets and leads to the movement of the closure member 19 into the open position.

The electromagnets or the coils 14 are thus presently designed so that they produce and release heat during operation of the valve - both during the opening movement of the closure member 19 and during the closing movement of the closure member or in the closed state of the valve 10, the Heating of the guided through the valve 10 glue is suitable.

Accordingly, the glue valve 10 can be supplied with so-called hot glue, which can be heated (heated) or kept at temperature in the valve 10 by the heat from the electromagnets.

The electromagnets thus fulfill a dual function in this embodiment of the invention. Through it, on the one hand, the closure member 20 is moved (intermittently) in the open position, on the other hand, heat is given to the usually already preheated hot glue.

As regards the power supply of the valve unit 11 of the valve 10 and the connection to suitable control lines, lead to the supply housing 12a via a line feed 31 more power supply and a plurality of control lines 32. The coils 14 supplying power lines 32 terminate within a channel 33rd the supply housing 12a on a plug 30a. The plug 30a is connected within the channel 33 with a matching mating connector 30b of the valve unit 1 1. From the plug 30b go corresponding power lines 34, which are connected to the coils 14.

Other lines 32 are connected to separate, sitting in recesses of the supply housing 12a heating cartridges 44 di serve to heat primarily the housing 12a of the supply unit 12 to thereby keep the glue liquid or not to cool too much while passing through the supply unit 12 flows.

In particular, together with the heat-generating electromagnets or coils 14, they serve to shorten the high-temperature heating times in which the valve (10) must be brought to working temperature before the actual start-up of the valve (10). For monitoring the housing or the conductor temperature, a temperature sensor 45 is furthermore arranged in a corresponding recess of the supply housing 12a.

Particularly important is the formation of the bobbin 15.

It is an injection-molded part, which consists of a corresponding injection-moldable, ceramic material with a high thermal conductivity of at least 15 Wirf ¹ "^{" 1.} It has been shown that silicon nitride (Si ₃ N ₄ - ceramic) is particularly suitable special properties of the silicon nitride ceramic make it possible to wind the coils 14 directly onto the cylindrical section 16 without the need for insulating substrates, since silicon nitride ceramic is an electrical insulator , insulating coatings of coil windings can break and in this case there would be a risk of short circuit. The high thermal conductivity of the silicon nitride bobbin 15 provides for optimal transfer of the heat generated by the coils 14 of the electromagnets to the glue. At the same time, the silicon nitride ceramic is temperature-resistant, so that it takes no damage even with long operating times of the glue valve 10.

By the coil carrier 15 can be injection molded, a cost-effective production of the same is also possible.

The bobbin 15 is - as already mentioned - arranged in the valve housing chamber 13 of the valve housing 11a. This chamber 13 or this interior is bounded and enclosed by a lower bottom wall 36a of the valve housing 1a, by lateral walls 36b of the valve housing 11a and by a cover wall 36c of the valve housing 11a. The cover wall 36c is part of a separate cover part 41 of the valve housing 1 1a.

Between the walls 36a, 36b, 36c and the coil support 15, a circumferential free space 37 is formed.

As part of the production of the glue valve 10, this clearance 37 is filled according to a further special feature of the invention with a heat-conductive potting compound 39, the heat conductivity value is preferably between 0.5 Wm ^"1 K ^{" 1} and 2.0 Wm ^"1 K ^'1 .

This potting compound 39 contacts the coils 14, in particular the side (s) facing the side walls 36b of the valve housing 11a. The turns of the coils (14) are usually arranged so that certain spaces or channels are formed between them. Through these potting compound 39 flows through to the bobbin 15.

As a result, at least a multiplicity of the coil windings are embedded in the potting compound 39 at least partially, preferably completely. The thermal conductivity of the potting compound 39 ensures optimum temperature distribution along the coils 14. Possible local heat peaks, in particular in the coils 14 or in the coil carrier 15, are degraded in this way or can not build up at all, so that over the entire coil carrier 15 as uniform as possible heat transfer to the same within the interior (18) located glue.

The potting compound 39 also ensures a non-detachable connection of the walls 36a-c of the valve housing 11a with the coil carrier 15 and the coils 14 arranged thereon.

As far as the production of the glue valve 10 is concerned, the valve unit 1 and the supply unit 12 form separate modules which are pre-assembled separately and later flanged or fastened to one another.

In a special way, the valve unit 11 is manufactured separately: The coil support 15 of the valve unit 11 is first - as already described - injection-molded in the context of an injection molding of silicon nitride. Later, the coils 14 of the two electromagnets are wound onto the finished bobbin 15. The bobbin 15 together with coils 14 is inserted together with coil carrier seals 40 in the already (initially without cover part 41) preassembled housing 11a of the valve unit 11. Subsequently, the lid part 41 is placed (see FIG. 3).

Via a filling channel 42, which is guided from the housing chamber 13 to the outside of one of the side walls 36b, namely up to an opening 43 in the side wall 36b, then the above-described space 37 and the free spaces / channels between the turns of the coil 14 filled with the potting compound 39.

Following this, the thus pre-assembled and filled unit is placed in a vacuum or space. Under the appropriate vacuum conditions, any air bubbles in the gas Potting compound 39, which would result in a deterioration of the thermal conductivity.

Subsequently, said unit is heated (baked) in a heater such as an oven.

Various other components of the valve unit 11, in particular the bobbin 15 together with the coils 14, the closure member 19, the magnet holder 30, other seals and the nozzle 22 are then inserted into the valve housing chamber 13 and mounted after cooling of the preassembled unit.

Finally, the lock nut 38 is screwed onto the threaded projection 35, and connected via the thread 46 with the cover part 41.

*****

LIST OF REFERENCE NUMBERS

10 line valve 35 threaded attachment

11 Valve unit 36a wall

11a valve housing 36b wall

12 supply unit 36c wall

12a supply housing 37 free space

13 Valve body chamber 38 Locknut

14 coils 39 potting compound

15 bobbin carriers 40 seals

16 hollow cylindrical section 41 cover part

17 Surface 42 Filling channel

18 Interior 43 Opening

19 closure element 44 heating cartridges

20 shaft 45 temperature sensor

21 ball 46 thread

22 valve opening

23 nozzle

24 hose connection

25 hose

26 glue channel

27 filters

28 glue channel

29 guide piece

30 magnet holders

30a plug

30b plug

31 cable feed

32 control line

33 channel

34 power line

Claims

claims

1. Valve for flowable media, in particular glue valve, with at least one electromagnet with which a closure member (19) of the valve (10) is movable and with the targeted heat to the flowable medium, preferably hot glue, transferable, wherein the at least one electromagnet at least one coil (14) which is arranged on a coil carrier (15) which at least partially surrounds the closure member (19), characterized in that the entire coil carrier (19), but at least the region (16) of the coil carrier (15 ), on which windings of the coil (14) lie directly, consists of an injection-moldable, ceramic material having a high thermal conductivity of at least 15 Wm ^'1 K ^{' 1} , particularly preferably of silicon nitride.

2. Valve according to claim 1, characterized in that the ceramic material, preferably the silicon nitride, has a thermal conductivity of at least 25 Wm ^"1 K ^{" 1} .

3. Valve according to claim 1 or 2, characterized in that the coil carrier (15) is an injection-molded part injection-molded from the ceramic material.

4. Valve according to one or more of the preceding claims, characterized in that the coil carrier (15) together with the at least one coil (14) in a particular at least partially hollow cylindrical chamber (13) within the valve housing (11a) sits, at least one free Room region (37) between at least one wall (36a, 36b, 36c) of the chamber (13) and the at least one coil (14) and / or the coil carrier (15) with a heat-conductive potting compound (39) is filled, preferably a potting compound ( 39) whose thermal conductivity value is between 0.5 Wm ^"1 K ^{" 1} and 2.0 Wm ^" K ^{" 1} .

5. Valve according to claim 4, characterized in that the chamber wall (36a, 36b, 36c) forms a Gehäuseaußenwandung.

6. Valve according to claim 4 or 5, characterized in that the valve has a filling channel (42) which is guided from the chamber (13) to the outside of a housing wall (36 b) of the valve (10), and over which the Chamber from the outside with the potting compound (39) can be filled.

7. Valve according to one or more of the preceding claims, characterized in that the potting compound (39) the coil carrier (13), the at least one coil (14) and the at least one chamber wall (36 a, 36 b, 36 c) inextricably interconnected.

8. Valve according to one or more of the preceding claims, characterized in that the valve (10) has two detachably interconnected modules, namely a valve unit (11), in which the closure member (19), the at least one coil (14) and the coil carrier (15) are arranged, and a supply unit (12) in which a connection (24) for a supply line (25) for the flowable medium is arranged, in particular a hose, and a supply for power and / or control lines.

9. Valve according to claim 8, characterized in that the valve unit (11) has a plug part (30b) are guided by the power and / or control lines (34) to at least one electrical component of the valve unit (1 1), preferably the at least one coil (14), wherein the plug part (30b) in the assembly of the valve (10) in a matching plug part (30a) of the supply unit (12) can be plugged, from the power and / or control lines (32) to the Feeding (31) of the supply unit (12) are guided.

10. A method for producing a valve according to claim 1, characterized by the following steps a) a coil carrier (15) is injection-molded from an injection-moldable, ceramic material with a high thermal conductivity of at least 15 Wm ^"1 K ^{" 1} ,

b) at least one coil (14) of at least one electromagnet is wound onto the injection-molded coil carrier (15),

c) the coil carrier (15) together with the at least one coil (14) is arranged in a chamber (13) of the valve housing (11a),

d) via a filling channel (42), which is guided from the chamber (13) to the outside of a wall (36b) of the valve housing (11a), a free space between at least one chamber wall (36) bounding the chamber (36a, 36b, 36c) and the at least one coil (14) and / or the coil carrier (15) from the outside filled with a potting compound.

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