Device for applying an adhesive

Abstract

The invention relates to an adhesive application device (100) for applying an adhesive. The adhesive application device (100) comprises an adhesive inlet designed to receive the adhesive, and an adhesive application nozzle designed to apply the adhesive. A first housing part (110) of the adhesive application device (100) defines a first section of an adhesive channel from the adhesive inlet to the adhesive application nozzle, and a second housing part (150) defines a second section of the adhesive channel. Furthermore, the adhesive application device (100) comprises a solenoid valve with a coil element (130) which defines a third section of the adhesive channel from the adhesive inlet to the adhesive application nozzle and is designed to generate a magnetic field when supplied with a current in order to control or meter the flow of adhesive through the adhesive channel.The coil element (130) is positively connected to the first housing part (110) or the second housing part (150), and the first housing part (110) and the second housing part (150) are detachably connected to one another via a bayonet connection such that the coil element (130) is arranged between the first housing part (110) and the second housing part (150).

Description

[0001] The invention relates to a device for applying an adhesive, for example a thermoplastic hot melt adhesive, with a solenoid valve for metering the amount of adhesive, and a method for spreading such a device.

[0002] Devices for applying an adhesive, particularly a hot melt adhesive, are used, among other things, in the packaging industry, for example, in the production of packaging or during the sealing of a package in a packaging machine. The hot melt adhesive is often initially in the form of granules, which are melted by a hot melt adhesive preparation device and then fed in liquid form under pressure to the adhesive application device. For metering the liquid hot melt adhesive, it is known to design the adhesive application device with a solenoid valve, which feeds a metered quantity of the liquid hot melt adhesive to an application nozzle. This nozzle then applies the liquid hot melt adhesive, often under pressure, for example, onto a package. Since the adhesive is applied under pressure via the solenoid valve and the application nozzle, the housing of the solenoid valve must be leak-proof.The housing must be designed so that no adhesive can escape. In conventional adhesive application devices, it is known to connect the housing parts that define the adhesive channel, in which the solenoid valve piston is movably mounted, using adhesively bonded spring pins. However, the use of adhesively bonded spring pins is only suitable for low-pressure applications, as otherwise the housing parts can be forced apart under the influence of pressure forces, allowing adhesive to escape.

[0003] For applications with higher adhesive pressures, it is known to join the housing components of the adhesive application device using laser welding. However, this requires the use of a housing material suitable for laser welding, such as stainless steel. This material selection is more demanding to process compared to stainless steel, which does not require laser welding. Additionally, the housing components cannot be separated non-destructively after welding, precluding reuse in the event of a solenoid valve failure. Separating the components by type is difficult, and the logistical effort from the production process to the fully welded adhesive application device is increased due to the complexity and cumbersome nature of the process.

[0004] Furthermore, it is known to screw the housing parts of an adhesive application device together. However, such a screw connection generally results in housing parts of unnecessarily large dimensions and consequently impairs the subsequent flexibility, for example with regard to the distance between the housing parts and thus the distance of the adhesive application device to the medium onto which the adhesive is applied.

[0005] Against this background, the object of the present invention is to provide an improved adhesive application device with a solenoid valve for metering the amount of adhesive, in which the housing parts of the adhesive application device are detachably connected to each other in such a way that no adhesive can escape even at high pressures.

[0006] According to a first aspect of the invention, the aforementioned problem is solved by an adhesive application device for applying an adhesive. The adhesive can, for example, be a hot melt adhesive.

[0007] The adhesive application device according to the first aspect comprises an adhesive inlet configured to receive the adhesive, and an adhesive application nozzle configured to apply the adhesive. A first housing part of the adhesive application device, in particular an inner part thereof, defines a first section of an adhesive channel from the adhesive inlet to the adhesive application nozzle. A second housing part of the adhesive application device, in particular an inner part thereof, defines a second section of the adhesive channel from the adhesive inlet to the adhesive application nozzle.The adhesive application device according to the first aspect further comprises a solenoid valve, in particular a directly controlled solenoid valve, with a coil element which defines a third section of the adhesive channel from the adhesive inlet to the adhesive application nozzle and is configured to generate a magnetic field when energized in order to control the flow of adhesive through the adhesive channel. According to the invention, the coil element is detachably connected to the first housing part or the second housing part in a form-fitting manner, wherein the first housing part and the second housing part are detachably connected to each other via a bayonet connection (also known as a bayonet lock) such that the coil element is arranged between the first housing part and the second housing part.Due to the positive locking of the coil element with the first or second housing part, the coil element can advantageously rotate with the housing part to which it is detachably connected when the first and second housing parts are connected via the bayonet fitting. In the adhesive application device according to the first aspect, the housing parts of the adhesive application device are detachably connected to one another in such a way that no adhesive can escape from the housing even under high pressure.

[0008] According to one embodiment, the adhesive application device according to the first aspect further comprises a first sealing element, in particular an O-ring, wherein the first sealing ring is arranged in a first contact area between the first housing part and the coil element and is designed to seal the adhesive channel.

[0009] In one embodiment, the adhesive application device according to the first aspect further comprises a second sealing direction, in particular an O-ring, wherein the second sealing ring is arranged in a second contact area between the second housing part and the coil element and is configured to seal the adhesive channel.

[0010] According to one embodiment, the solenoid valve comprises a connection element, in particular a connector or a connecting cable, wherein the connection element is configured to connect a power source to the coil element in order to supply the coil element with a current. The connection element is positively locked to the first housing part or the second housing part and materially bonded to the coil element of the solenoid valve. Due to the positive locking of the connection element with one of the housing parts, the connection element can advantageously rotate with the corresponding housing part when the first housing part is connected to the second housing part via the bayonet fitting.

[0011] In one embodiment, the positive-locking connection between the coil element and the first housing part or the second housing part releasably comprises at least one pin and at least one pin recess. Particularly in an embodiment where the connecting element is designed in the form of a connecting cable, the coil element and the connecting cable can rotate with the corresponding housing part due to the connection via the pin.

[0012] According to one embodiment, the bayonet connection between the first housing part and the second housing part comprises a plurality of bayonet lugs and a plurality of correspondingly shaped bayonet recesses into which the bayonet lugs can engage.

[0013] In one embodiment, the solenoid valve further comprises an armature element, in particular a valve piston, wherein the armature element is movably arranged in the adhesive channel and is configured to move relative to the coil element by means of the magnetic field generated by the coil element in order to control the flow of adhesive through the adhesive channel.

[0014] According to one embodiment, the adhesive application device further comprises a preloading element, in particular a return spring element, which is designed to preload the armature element, in particular the valve piston, into a locking position in which the solenoid valve is closed.

[0015] In one embodiment, the preload element, in particular the return spring element, is arranged in the first housing part. Alternatively, the preload element, in particular the return spring element, can be arranged in the second housing part.

[0016] According to a second aspect of the invention, the above problem is solved by a method for providing an adhesive application device with an adhesive inlet configured to receive the adhesive and an adhesive application nozzle configured to apply the adhesive. The method according to the second aspect comprises: Providing a first housing part, wherein the first housing part, in particular an inner part thereof, defines a first section of an adhesive channel from the adhesive inlet to the adhesive application nozzle; Providing a second housing part, wherein the second housing part, in particular an inner part thereof, defines a second section of the adhesive channel from the adhesive inlet to the adhesive application nozzle; Providing a solenoid valve, in particular a directly controlled solenoid valve, with a coil element which defines a third section of the adhesive channel from the adhesive inlet to the adhesive application nozzle and is designed to generate a magnetic field when a current is applied in order to control the flow of adhesive through the adhesive channel; positive locking connection of the coil element to the first housing part or the second housing part; and Detachable connection of the first housing part to the second housing part via a bayonet fitting, so that the coil element is arranged between the first housing part and the second housing part.

[0017] Further embodiments of the method according to the second aspect of the invention will become apparent to the person skilled in the art from the further embodiments of the device according to the first aspect of the invention described above and below.

[0018] The invention will now be described in more detail with reference to exemplary embodiments and the figures. The figures show: Fig. 1 an exploded view of an adhesive application device according to one embodiment; Fig. 2 a side view in cross-section of an adhesive application device according to one embodiment; Fig. 3a a perspective view of the first housing part of an adhesive application device according to one embodiment; Fig. 3b a perspective view of the second housing part of an adhesive application device according to one embodiment; Fig. 4 a sequence of perspective views of an adhesive application device according to an embodiment when connecting the first housing part with the second housing part of the adhesive application device; Fig. 5 an exploded view of an adhesive application device according to a further embodiment; and Fig. 6 a flowchart showing steps of a method according to the invention for providing an adhesive application device according to one embodiment.

[0019] The following detailed description refers to the accompanying figures, which form part thereof and illustrate specific embodiments in which the invention can be implemented. It is understood that other embodiments can also be used and structural or logical modifications can be made without deviating from the concept of the present invention. Therefore, the following detailed description is not to be understood as limiting. Furthermore, it is understood that the features of the various embodiments described herein can be combined with one another, unless specifically stated otherwise.

[0020] The aspects and embodiments of the present invention are described with reference to the figures, where the same reference numerals generally refer to the same elements. For explanatory purposes, numerous specific details are set forth in the following description to provide a thorough understanding of one or more aspects of the present invention.

[0021] Fig. Figure 1 shows an exploded view of an adhesive application device 100 according to an embodiment for applying an adhesive. The adhesive can, for example, be a hot melt adhesive. The adhesive application device 100 can, for example, be part of a packaging machine for manufacturing, in particular gluing, packaging.

[0022] As further explained below with reference to the Fig. As described in detail in Section 2, the adhesive application device 100 comprises an adhesive inlet 115, which is configured to receive the adhesive (which is supplied under pressure, for example, by an adhesive preparation device), and an adhesive application nozzle 155, which is configured to apply the adhesive, for example, to packaging made of cardboard material. The adhesive application device 100 comprises a first housing part 110, which defines a first section 110a of an adhesive channel from the adhesive inlet 115 to the adhesive application nozzle 155. Furthermore, the adhesive application device 100 comprises a second housing part 150, which defines a second section 150a of the adhesive channel from the adhesive inlet 115 to the adhesive application nozzle 155. As described in detail in Section 2, the adhesive application device 100 comprises an adhesive inlet 115, which defines a second section 150a of the adhesive channel from the adhesive inlet 115 to the adhesive application nozzle 155. Fig. As can be seen from 2, the adhesive channel runs from the adhesive inlet 115 to the adhesive application nozzle 155 essentially along a longitudinal axis A of the adhesive application device 100.

[0023] The adhesive application device 100 further comprises a solenoid valve, in particular a directly controlled solenoid valve, with a coil element 130, which defines a third section 130a of the adhesive channel from the adhesive inlet 115 to the adhesive application nozzle 155 and is configured to generate a magnetic field when energized in order to control or meter the flow of adhesive through the adhesive channel. The coil element 130 can comprise at least one electrical coil 132. In the Fig. In the embodiment shown in Figure 1, the coil element 130 is detachably connected to the first housing part 110 via a connecting pin 121 (in alternative embodiments, the coil element 130 can be detachably connected to the second housing part 150). As this is shown in particular in the Fig. 2, Fig. 3a and Fig. As can be seen from Figure 3b, the first housing part 110 and the second housing part 150 are detachably connected to each other via a bayonet connection (also known as a bayonet lock) such that the coil element 130 is arranged between the first housing part 110 and the second housing part 150. The bayonet connection between the first housing part 110 and the second housing part 150 comprises a plurality of bayonet lugs 122a-d and a plurality of correspondingly shaped bayonet recesses 152a-d into which the bayonet lugs 122a-d can engage in order to form the bayonet connection between the first housing part 110 and the second housing part 150 by means of a rotational movement about the longitudinal axis A of the first housing part 110 relative to the second housing part 150.As the person skilled in the art will recognize, due to the positive locking of the coil element 130 with the first housing part 110, the coil element 130 rotates advantageously with the first housing part 110 when the first housing part 110 is connected to the second housing part 150 via the bayonet fitting. As shown in the figure below. Fig. As can be seen from the sequence shown in Figure 4, it can be ensured that a connecting element 131, which is designed to connect a current source to the coil element 130 in order to supply the coil element 130 with a current and is positively connected to the first housing part 110 and materially connected to the coil element 130 of the solenoid valve, is not damaged during the formation of the bayonet connection between the first housing part 110 and the second housing part 150.

[0024] At the in Fig. In the sequence shown in Figure 4, which illustrates the formation of the bayonet connection between the first housing part 110 and the second housing part 150, the first housing part 110 with the inserted coil element 130 is first pushed into the second housing part 150 until both housing parts 110 and 150 are flush. By rotating the housing parts 110 and 150 in opposite directions until they reach their stop, the bayonet lugs 122a-d move into the bayonet recesses 152a-d, creating a secure connection that can only be released by deliberate loosening. The compression of the O-rings 120 and 140 ensures a secure hold of the bayonet fitting and prevents unintentional loosening.

[0025] During the Fig. In the embodiment shown in Figure 1, the connecting element 131 is designed as a connecting cable 131. In this embodiment, the positive-locking connection of the coil element 130 with the first housing part 110 thus prevents the strands of the connecting cable 131 protruding from an elongated hole in the coil element 130 from shearing off. According to a further embodiment shown in Fig. In the embodiment shown in Figure 5, the connecting element 131 can be designed in the form of a connector plug 131.

[0026] In the embodiments shown in the figures, the adhesive application device 100 further comprises a first sealing element 120, in particular an O-ring 120, wherein the first sealing ring 120 is arranged in a first contact area between the first housing part 110 and the coil element 130 and is designed to seal the adhesive channel, and a second sealing element 140, in particular an O-ring 140, wherein the second sealing ring 140 is arranged in a second contact area between the second housing part 150 and the coil element 130 and is designed to seal the adhesive channel.

[0027] Again Fig. As can be seen from Figure 2, the solenoid valve of the adhesive application device 100 further comprises an armature element 133, in particular a valve piston 133, wherein the armature element 133 is movably arranged in the adhesive channel and is configured to move relative to the coil element 130 by means of the magnetic field generated by the coil element 130 in order to control or meter the flow of adhesive through the adhesive channel. The solenoid valve of the adhesive application device 100 further comprises a biasing element 154, in particular a return spring element 154, which is configured to bias the armature element 133, in particular the valve piston 133, into a locked position in which the solenoid valve is closed when the coil element 130 is not energized. In the Fig. In the embodiment shown in Figure 2, the preload element 154, in particular the return spring element 154, is arranged in the second housing part 150.

[0028] Fig.Figure 6 is a flowchart illustrating a method 600 for providing an adhesive application device 100, wherein, as described above, the adhesive application device 100 comprises an adhesive inlet configured to receive the adhesive and an adhesive application nozzle configured to apply the adhesive. The method 600 comprises providing 601 a first housing part 110, wherein the first housing part 110, in particular an inner surface thereof, defines a first section 110a of an adhesive channel from the adhesive inlet to the adhesive application nozzle. Furthermore, the method 600 comprises providing 603 a second housing part 120, wherein the second housing part 120, in particular an inner surface thereof, defines a second section of the adhesive channel from the adhesive inlet to the adhesive application nozzle.Method 600 further comprises providing 605 a directly controlled solenoid valve with a coil element that defines a third section of the adhesive channel from the adhesive inlet to the adhesive application nozzle and is configured to generate a magnetic field when energized to control the flow of adhesive through the adhesive channel. Method 600 further comprises positively connecting 607 the coil element to the first housing part or the second housing part. Method 600 further comprises releasably connecting 609 the first housing part to the second housing part via a bayonet fitting, such that the coil element is arranged between the first housing part and the second housing part.

[0029] Further embodiments of the method 600 will become apparent to the person skilled in the art from the further embodiments of the adhesive application device 100 described above and below.

Claims

[1] Adhesive application device (100) for applying an adhesive, the adhesive application device (100) comprising: an adhesive inlet (115) which is designed to receive the adhesive; an adhesive application nozzle (155) which is designed to apply the adhesive; a first housing part (110), wherein the first housing part (110) defines a first section (110a) of an adhesive channel from the adhesive inlet (115) to the adhesive application nozzle (155); a second housing part (150), wherein the second housing part (150) defines a second section (150a) of the adhesive channel from the adhesive inlet (115) to the adhesive application nozzle (155); and a solenoid valve with a coil element (130) which defines a third section (130a) of the adhesive channel from the adhesive inlet (115) to the adhesive application nozzle (155) and is designed to generate a magnetic field when a current is applied in order to control the flow of adhesive through the adhesive channel; wherein the coil element (130) is positively connected to the first housing part (110) or the second housing part (150), and wherein the first housing part (110) and the second housing part (150) are detachably connected to each other via a bayonet connection such that the coil element (130) is arranged between the first housing part (110) and the second housing part (150). [2] Adhesive application device (100) according to claim 1, wherein the adhesive application device (100) has a first sealing direction (120), in particular an O-ring (120), wherein the first sealing ring (120) is arranged in a first contact area between the first housing part (110) and the coil element (130) and is designed to seal the adhesive channel. [3] Adhesive application device (100) according to claim 1 or 2, wherein the adhesive application device (100) has a second sealing direction (140), in particular an O-ring (140), wherein the second sealing ring (140) is arranged in a second contact area between the second housing part (150) and the coil element (130) and is configured to seal the adhesive channel. [4] Adhesive application device (100) according to one of the preceding claims, wherein the solenoid valve comprises a connection element (131) configured to connect a power source to the coil element (130) in order to supply the coil element (130) with a current, and wherein the connection element (131) is positively connected to the first housing part (110) or the second housing part (150). [5] Adhesive application device (100) according to one of claims 1 to 3, wherein the positive locking connection between the coil element (130) and the first housing part (110) or the second housing part (150) comprises at least one pin (121) and at least one pin recess. [6] Adhesive application device (100) according to one of the preceding claims, wherein the bayonet connection between the first housing part (110) and the second housing part (150) comprises a plurality of bayonet lugs (122a-d) and a plurality of correspondingly shaped bayonet recesses (152a-d). [7] Adhesive application device (100) according to one of the preceding claims, wherein the solenoid valve further comprises an armature element (133), in particular a valve piston (133), which is movably arranged in the adhesive channel and is designed to move relative to the coil element (130) by means of the magnetic field generated by the coil element (130) in order to control the flow of adhesive through the adhesive channel. [8] Adhesive application device (100) according to claim 7, wherein the adhesive application device (100) further comprises a preloading element (154), in particular a return spring element (154), which is configured to preload the armature element (133), in particular the valve piston (133), into a locking position in which the solenoid valve is closed. [9] Adhesive application device (100) according to claim 8, wherein the preload element (154), in particular the return spring element (154), is arranged in the first housing part (110) or the second housing part (150). [10] Method (600) for providing an adhesive application device (100) with an adhesive inlet (115) configured to receive the adhesive and an adhesive application nozzle (155) configured to apply the adhesive, wherein the method (600) comprises: - Providing (601) a first housing part (110), wherein the first housing part (110) defines a first section (110a) of an adhesive channel from the adhesive inlet (115) to the adhesive application nozzle (155); - Providing (603) a second housing part (150), wherein the second housing part (150) defines a second section (150a) of the adhesive channel from the adhesive inlet (115) to the adhesive application nozzle (155); - Providing (605) a solenoid valve with a coil element (130) which defines a third section (130a) of the adhesive channel from the adhesive inlet (115) to the adhesive application nozzle (155) and is configured to generate a magnetic field when a current is applied in order to control the flow of adhesive through the adhesive channel; - positive locking connection (607) of the coil element (130) with the first housing part (110) or the second housing part (150); and - Detachable connection (609) of the first housing part (110) with the second housing part (150) via a bayonet fitting, so that the coil element (130) is arranged between the first housing part (110) and the second housing part (150).

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