Equipment for flow control of adhesives and methods for their manufacture

Abstract

The present invention relates to a flow control device for an adhesive, comprising: a housing including a first housing component and a second housing component; a leakage chamber formed by the housing components, wherein a first sealing element and a second sealing element are respectively disposed in the housing components; a needle disposed in the housing and passing through the leakage chamber, wherein the sealing element is pressed against the surface of the needle; and a spacing retainer disposed between the sealing elements, wherein the spacing retainer has a through-hole surrounding the needle and at least one transverse hole.

Description

Technical Field

[0001] This invention relates to a device for flow control of adhesives. Background Technology

[0002] The above-described type of equipment is used in the flow control of adhesives such as melt adhesives, hot adhesives, or cold adhesives. For example, the equipment is used for applying adhesives to a substrate or transporting adhesives between functional units of a facility, in a manner in which the equipment is turned on or off.

[0003] The devices are capable of controlling the flow of adhesives, even when the adhesive flow is under overpressure relative to the environment. These devices must include components that protect the portion of the device controlling the adhesive flow from the flowing adhesive, especially when the adhesive is being delivered under overpressure relative to the environment. A challenge in the design of known devices for adhesive flow control is that the lifespan of these devices is limited by the components that ensure a pressure seal relative to the adhesive flow. That is, when a portion of the device controlling the adhesive flow is no longer sealed and is undesirably filled with adhesive, a replacement for the adhesive flow control device is often required. Summary of the Invention

[0004] Therefore, the present invention aims to provide a device for flow control of adhesives, which has a simple construction and an improved service life.

[0005] This objective is achieved according to the invention by means of the device according to the invention.

[0006] The device for flow control of adhesives according to the present invention includes a housing. The housing includes lower and upper housing components. The lower and upper housing components constitute the structure of the device.

[0007] Each housing component has a recess that forms a leakage chamber in the installed state. In each housing component, at least one sealing element is disposed in the corresponding recess. Therefore, at least two sealing elements are provided in the housing.

[0008] A gap retainer is provided in the leakage chamber between the sealing elements, wherein the gap retainer has a through port and at least one transverse hole, wherein the transverse hole connects the through port of the gap retainer to the leakage chamber. In the event of damage to one of the sealing elements, adhesive can flow into the leakage chamber through the through port via the at least one transverse hole.

[0009] The device also includes a needle disposed within the housing, which is movable to a closed position and an open position to open and close the adhesive flow. To maintain a seal in both the closed and open positions, a sealing element is pressed against the surface of the needle. Therefore, it is ensured that no adhesive remains adhered to the surface of the needle when moving from the closed position to the open position.

[0010] For example, a needle is driven in an actuator chamber belonging to the device to open or close a fluid chamber formed in the device housing.

[0011] The advantageous improvement in the lifespan of the device is achieved by spaced-apart sealing elements within the leak chamber via spacing retainers, because in the event of failure of the first sealing element, the leak chamber is first filled with adhesive through at least one lateral hole in the spacing retainer before the adhesive reaches the second sealing element. Therefore, the present invention achieves reliable and durable separation of the fluid space from the actuator space for flow control of adhesives. Furthermore, the leak chamber constructed according to the invention has a self-healing function for the device. This effect is achieved when the adhesive located in the leak chamber cures and, in this case, at least partially closes the leak in the first sealing element that caused the adhesive to enter the leak chamber.

[0012] The solution according to the invention can be further improved through different, each advantageous in itself and which can be arbitrarily combined with each other. These embodiments and their associated advantages will be discussed below.

[0013] According to the first possible design, the spacing retainer can be configured as a separation column with multiple transverse holes. Thus, after the failure of the first sealing element, the leakage chamber can be uniformly filled through the multiple transverse holes.

[0014] The uniform load on the first and second sealing elements results in an improved service life and is advantageously achieved in the device according to the invention by providing at least one transverse hole adjacent to the first sealing element and at least one transverse hole adjacent to the second sealing element in the separation column.

[0015] In an advantageous design, the through-hole of the spacing retainer has a diameter that mates with the needle, creating a first gap between the spacing retainer and the needle. This first gap is large enough to prevent pumping and capillary action caused by the movement of the needle. If the adhesive has already flowed through the leakage point of the first sealing element, this simplifies the adhesive's reach into the transverse orifice.

[0016] According to another possible design, the end of the separating column is configured as a disc, wherein each disc is shape-fittingly and fixedly connected to a corresponding housing component groove into which the disc is inserted. The end of the separating column can also be configured as an annular disc, wherein each annular disc is shape-fittingly and fixedly connected to a corresponding housing component groove into which the annular disc is inserted. This achieves stable positioning of the sealing element within the device housing.

[0017] Advantageously, the needle has a polished surface in at least one section in which it contacts the sealing element. This achieves more uniform contact between the needle and the sealing element and improves the effectiveness of the individual sealing elements.

[0018] According to another possible design, one of the housing components has an additional groove for accommodating a third sealing element disposed between the housing components. This would seal the housing of the device from the outside.

[0019] According to an advantageous design, the device according to the invention is configured as a coating valve for applying adhesives or a self-healing coating valve.

[0020] The initial objective can also be achieved through a method.

[0021] A method for manufacturing the device according to the invention includes the following steps:

[0022] The first sealing element is installed into the housing component with the first groove.

[0023] A spacer element with a through-hole is introduced into the housing component equipped with the first sealing element.

[0024] The second sealing element is installed into the second housing component, which has the second groove.

[0025] Connect the assembled housing components to form a housing and create a leakage chamber.

[0026] The driven needle is pushed through the housing and through the through-hole.

[0027] This method enables the manufacture of equipment with a simplified structure and an extended service life.

[0028] The advantages described regarding the device also apply to the method according to the invention, and vice versa. Attached Figure Description

[0029] The invention is described in detail below with reference to the accompanying drawings. The combinations of features exemplarily shown in the illustrated embodiments can be supplemented by other features to meet the specific application requirements of the device and / or method according to the invention, based on the above embodiments. Individual features can also be omitted in the described embodiments if their effect is not significant in the specific application. In the drawings, the same reference numerals are always used for elements with the same function and / or the same structure.

[0030] The attached diagram shows:

[0031] Figure 1 A cross-sectional view of the device according to the invention in its assembled form is shown;

[0032] Figure 2 A detailed view is shown in a cross-sectional view of the leakage chamber of a device according to an exemplary embodiment of the invention;

[0033] Figure 3 A perspective view of the spacing retainer of the device according to the present invention is shown;

[0034] Figure 4a A detailed perspective view of the needle surface with a sealing element is shown; and

[0035] Figure 4b A detailed perspective view of the polished needle surface with sealing elements is shown. Detailed Implementation

[0036] In the following text, refer to Figure 1 and Figure 2 The device 20 according to the present invention is described. (Refer to...) Figure 3 A perspective view of the spacing retainer 5 belonging to the device 20 according to the present invention is described. Furthermore, according to... Figure 4a and 4b Describe two detailed views of needle surfaces 16 and 17.

[0037] Figure 1 A cross-sectional view of an exemplary embodiment of device 20 is shown. Device 20 is configured for controlling the output, metering, and / or transport of adhesives, particularly for controlling the flow of adhesives at pressures higher than ambient pressure. Therefore, device 20 can, for example, but not only as part of a device for metering or discharging adhesives or as part of a device for transporting adhesives (not shown).

[0038] Reference Figure 1The device 20 has a housing 21, which includes at least one lower housing component 3 and an upper housing component 4. The housing 21 also includes a fluid chamber 1 filled with an adhesive that flows into the device 20 through a hole 14.

[0039] Housing component 3 has a groove 23 and housing component 4 has a groove 22. Grooves 22 and 23 form a leakage chamber 10 in the installed state. In each housing component 3, 4, at least one sealing element 7, 8 is disposed adjacent to the corresponding groove 22, 23. Therefore, at least two sealing elements 7, 8 are disposed in the housing 21.

[0040] A gap retainer 5 is provided in the leakage chamber 10 between sealing elements 7 and 8. The gap retainer 5 has a through-hole 27 and at least one transverse hole 11. Here, the transverse hole 11 connects the through-hole 27 of the gap retainer 5 to the leakage chamber 10. In the event of damage to one of the sealing elements 7 or 8, the adhesive leaving the fluid chamber 1 can be discharged into the leakage chamber 10 through the through-hole 27 via the at least one transverse hole 11.

[0041] Device 20 also has a needle 6 disposed in housing 21, which is movable to a closed position and an open position to open and close the adhesive flow. The needle 6 is driven, for example, in an actuator chamber 2 belonging to device 20, to open or close a fluid chamber 1 formed in device housing 21. In the open position (not shown), the adhesive flow is released from device 20 through opening 28. In the closed position (according to…)… Figure 1 The adhesive flow through opening 28 is interrupted by needle 6. Therefore, in the closed position of needle 6, no adhesive flows out of device 20.

[0042] To further protect the actuator chamber 2 from the flow of adhesive, the flow of which is controlled by a driven needle 6, the housing 21 has a pressure-sealed leakage chamber 10, which is constructed in... Figure 2 The details are shown below. Adjacent to the groove 22, the housing component 4 is equipped with a sealing element 8. Adjacent to the groove 23, the housing component 3 is equipped with a sealing element 7. A spacing retainer 5 is provided between the sealing elements 7 and 8, the spacing retainer having a through opening 27 and surrounding the needle 6 in the leakage chamber 10.

[0043] according to Figure 2Housing components 3 and 4 are joined together on their respective sides facing the grooves 22 and 23, forming a leakage chamber 10. Housing components 3 and 4, together with the spacing retainer 5, form a movement channel for the needle 6, which is guided through the leakage chamber 10 into the fluid chamber 1, and is sealed by the two sealing elements 7 and 8. Due to the leakage chamber 10, the device 20 has a self-healing effect. This effect is achieved, in particular, when the adhesive located in the leakage chamber 10 cures and, in this case, at least partially closes the leak point in the sealing element 7 again.

[0044] The sealing element 7, located adjacent to the fluid space 1 in the lower housing component 3, absorbs the pressure of the adhesive introduced into the fluid chamber 1 through the first hole 14. Thus, the first sealing element 7 prevents the leakage chamber 10 from being immediately filled with adhesive from the fluid chamber 1, and maintains the fluid tightness of the device 20. In the upper housing component 4, a second sealing element 8 is located downstream of the first sealing element 7 in terms of pressure technology and prevents the adhesive from leaving the leakage chamber 10.

[0045] If sealing element 8 fails and adhesive leaves the leakage chamber, then a hole 15 is provided in the upper housing component 4, through which adhesive can leave, so that even if both sealing elements 7 and 8 fail, no adhesive can enter the actuator chamber 2. Figure 1 Sealing elements 7 and 8 are held at a distance and fixed by a spacing retainer 5. The spacing retainer 5 has at least one transverse hole 11, which allows adhesive that has undesirably flowed through sealing element 7 to enter the leakage chamber 10. Thus, adhesive that has already passed through sealing element 7 can accumulate in the leakage chamber 10 before the second sealing element 8 is loaded with adhesive. In the device 20 for controlling adhesive flow, this arrangement achieves increased service life while maintaining a simple design.

[0046] according to Figure 3 The spacing retainer 5 can be configured as a separation column having multiple transverse holes 11a to 11d, thereby allowing for more uniform filling of the leakage chamber 10. The separation column can have: at least one transverse hole 11b, 11d, which is disposed adjacent to the first sealing element 7 in the installed state of the device 20; and at least one transverse hole 11a, 11c, which is disposed adjacent to the second sealing element 8 in the installed state of the device 20.

[0047] The spacing retainer 5, configured as a separating column, can form a first gap 12 relative to the needle 6 with a correspondingly selected diameter of the through-hole 27. The gap 12 is selected in this case to be large enough to prevent pumping and capillary action caused by the movement of the needle 6.

[0048] The ends of the separating column can be configured as annular disks 26a, 26b ( Figure 3 The annular disk is used to stably position the separation column within the housing 21 of the device 20.

[0049] Sealing elements 7 and 8 can be flexibly configured and each has an inner ring 18a, 18b and an outer ring 19a, 19b. The inner rings 18a, 18b can be configured as sealing edges that contact the surfaces 16, 17 of the needle 6. The outer rings 19a, 19b can be configured as tensioning elements that press the sealing edges of the inner rings 18a, 18b against the surfaces 16, 17 of the needle 6. Alternatively, sealing element 7 and / or sealing element 8 can include a plurality of sealing rings (not shown) arranged in series, provided that the recess provided for this purpose in the housing 21 of the device 20 has sufficient structural space.

[0050] Needle 6 ( Figure 4a Surface 16 of the sealing element 7 can typically have machining marks and damage, such as scratches, pores, or abrasions. Adhesive may remain in these damaged areas within the fluid space 1. If the actuator in the actuator chamber 2 is operated and the needle 6 is lifted, a small amount of adhesive will reach behind the sealing edge 18b of the sealing element 7. Over time, this small amount of adhesive can cause a progressively larger leak. To prevent or at least reduce this, the needle 6 can be machined in the areas of the sealing elements 7, 8 to minimize scratches, pores, and abrasions, and to have a polished surface 17 at least in the mentioned areas. Figure 4b In this invention, a polished surface is understood as a machined surface (17) with an average roughness depth (Rz) of less than 1 μm.

[0051] Housing components 3 and 4 can be sealed via a third sealing element 9, particularly via a static sealing element. According to Figure 1 The sealing element 9 is located, for example, between housing parts 3 and 4, in a groove 24 provided for this purpose in the upper housing part 4.

[0052] If the leak chamber 10 is filled after the sealing element 7 fails and the sealing element 8 also fails, then the liquid exits outward through the hole 15 in the upper housing member 4. The upper housing member 4 is advantageously provided with an outflow groove 25 adjacent to the hole 15 to form a second gap 13 relative to the needle 6, wherein the second gap 13 is large enough to prevent pumping and capillary action caused by the movement of the needle 6.

[0053] In the method for manufacturing the device 20, a first sealing element 7 is inserted into a housing component 3 having a first groove 22. Then, a spacing retainer 5 having a through-hole 27 is inserted into the housing component 3 equipped with the sealing element 7. Subsequently, a second sealing element 8 is inserted into a housing component 4 having a second groove 23. The housing components 3 and 4 equipped with the sealing elements 7 and 8 are connected to form a housing 21, thereby forming a leakage chamber 5. Then, a needle 6 is pushed through the housing 21 and through the through-hole 27 of the spacing retainer 5.

Claims

1. An apparatus (20) for flow control of adhesives, comprising: - A housing (21), the housing comprising a first housing component (3) and a second housing component (4), wherein at least one first sealing element (7) and a second sealing element (8) are provided in the housing (21). -A pressure-sealed leakage chamber (10) formed by the housing components (3, 4), - A spacing retainer (5) is disposed in the leakage chamber (10) between the sealing elements (7, 8), the spacing retainer having a through port (27) and at least one transverse hole (11), wherein the transverse hole (11) connects the through port (27) to the leakage chamber (10). -The needle (6) disposed in the housing (21) is guided through the through port (27) to open and close the adhesive flow, wherein the sealing elements (7, 8) are pressed on the surfaces (16, 17) of the needle (6), and wherein, in the event of failure of the first sealing element (7), the adhesive can flow into the leakage chamber (10) through the transverse hole (11), wherein a hole (15) is provided in the second housing component (4), the hole being configured such that when the second sealing element (8) fails and the adhesive flows out from the leakage chamber (10), the adhesive can flow out, such that even if both the first sealing element (7) and the second sealing element (8) fail, no adhesive enters the actuator chamber (2) for driving the needle (6).

2. The device (20) according to claim 1, wherein the spacing retainer (5) is configured as a separation column having a plurality of transverse holes (11).

3. The device (20) according to claim 2, wherein at least one transverse hole (11b, 11d) in the separation column is disposed adjacent to the first sealing element (7), and at least one transverse hole (11a, 11c) is disposed adjacent to the second sealing element (8).

4. The device (20) according to claim 2 or 3, wherein the diameter of the through-hole (27) is selected such that a first gap (12) is created between the through-hole (27) and the needle (6), thereby preventing pumping and capillary action caused by the movement of the needle (6).

5. The device (20) according to any one of claims 2 to 3, wherein the end of the separating column (5) is configured as a disc (26a, 26b), wherein each disc (26a, 26b) is shaped-fitted and fixedly connected to a corresponding housing component groove (22, 23).

6. The device (20) according to any one of claims 1 to 3, wherein the needle (6) has a polished surface (17) at least in the section in which it contacts the sealing element (7, 8).

7. The device (20) according to any one of claims 1 to 3, wherein the sealing elements (7, 8) respectively comprise an inner ring (18a, 18b) and an outer ring (19a, 19b), wherein the inner ring (18a, 18b) is configured as a sealing edge in contact with the needle (6), and wherein the outer ring (19a, 19b) is configured as a tensioning element that presses the sealing edge onto the needle surface (16, 17).

8. The device (20) according to any one of claims 1 to 3, wherein one of the housing components (3, 4) has an additional groove (24) for receiving a third sealing element (9).

9. The device (20) according to any one of claims 1 to 3, wherein the upper housing component (4) adjacent to the second sealing element (8) has an outflow groove (25), the shape and size of which are selected such that a second gap (13) is generated at least partially between the needle (6) and the housing component (4) when the needle (6) passes through, wherein the gap (13) is large enough to prevent pumping and capillary action caused by the movement of the needle (6).

10. A method for manufacturing the device (20) according to any one of the preceding claims, comprising the following steps: - The first sealing element (7) is inserted into the housing component (3) which has the first groove (22). - Introduce the spacing element (5) with the through opening (27) into the housing component (3) equipped with the first sealing element (7). - The second sealing element (8) is inserted into the second housing component (4) which has the second groove (23). - The housing components (3, 4) to be fitted are connected to form a housing (21), thereby forming a pressure-sealed leakage chamber (5). - Push the needle (6) through the housing (21) and through the through-hole (27).

Images