WO2003062092A1

WO2003062092A1 - Valve

Info

Publication number: WO2003062092A1
Application number: PCT/EP2003/000729
Authority: WO
Inventors: Mathias Pauls; Torsten Kellner
Original assignee: Rathor Ag
Priority date: 2002-01-24
Filing date: 2003-01-24
Publication date: 2003-07-31
Also published as: US20050121476A1; DE50312132D1; ATE449015T1; EP1485309B1; EP1485309A1

Abstract

The invention relates to a valve for discharging foaming agents from pressurised containers. Said valve seals off the pressurised container from the exterior and comprises an outlet with a closure part (4) located therein in a displaceable manner, said part being retained in the closed position by a spring element (21) and exposing an outlet for the foaming agent that is contained in the pressurised container by external actuation. According to the invention, the valve is mounted on a container cover that is configured as a valve face (1) in such a way that said valve face (1) has a sealing surface that is configured as a valve seat (6) and that co-operates with a sealing element (7). The valve face (1) and the sealing element (7) consist of a rigid material that does not deform as a result of the function of said parts and the sealing action is obtained by an elastic element (17) that is located on the valve face (1). The spring element (9, 21, 30), which retains the sealing element (7) in its closed position is fixed directly to the valve face (1).

Description

Valve

The invention relates to a valve, in particular for dispensing foaming agents from pressure containers, which closes the pressure container from the outside and has an outlet opening with a more flexible arranged closure part, which is held in the closed position by a spring element and an outlet opening for the one present in the pressure container by external actuation Foaming agent releases, the valve being mounted on a container cover designed as a valve plate.

Assembly foams, especially polyurethane foams, have found a large field of application in technology. They are used in construction to fasten elements such as door frames and other prefabricated parts, to close openings and to foam cavities and pockets. They are widely used for heat and sound insulation. They are also suitable for preventing condensation with subsequent corrosion in cavities filled with it. For the same reasons, automotive construction is also increasingly using assembly foams.

The one-component polyurethane foams that are frequently used for foaming are formed from the prepolymer contained in the pressure vessel by the action of moisture, in particular atmospheric moisture. After the mixture of blowing agent and foaming agent has been released, a reaction takes place between the prepolymer and the moisture contained in the air. That leads to the formation of the permanent Foam. Depending on the moisture content of the air, curing takes place in a more or less short time. If the air humidity is high, curing takes only a few minutes. The same applies to silane-terminated

Polyurethane foams. 1, 5K and two-component foams additionally contain a separate crosslinker component in the pressure cell.

Special valves are used to discharge or discharge the foam, which release the path of the foam by tilting or pushing it in. On the other hand, they must ensure a secure seal during transport and intermediate storage. If the seal is insufficient, moisture diffuses into the valve mechanism, so that the prepolymers harden in the valve and impair its proper functioning. In extreme cases, the valve is completely blocked by the polymer formed in it.

Special valves are known which are arranged in the head or dome part of such a pressure vessel and are held by means of a rubber seal. By tilting the valve tube or star, the foam between the rubber seal and the end plate of the hollow tube can enter the cutouts in the tube wall provided for this purpose and thereby exit the pressure vessel.

Although these tilt valves have a relatively good sealing mechanism, the tilting movement required to release the prepolymer / blowing agent mixture is generally perceived as a disadvantage. The targeted application of the assembly foam is made difficult by the fact that the outflow direction of the mixture changes due to the tilting movement. Furthermore, the tilting mechanism is not very suitable for using mechanical spreading aids, such as spray guns. Since the valve tube can rotate in the seal, it tries to avoid the tilting movement by turning it.

Also known are poppet valves in which the valve closure element is connected via a helical spring to a holding part as an abutment. The holding part protrudes freely into the interior of the pressure vessel. The spring is inserted between the holding part and the valve closure element and ensures its tight fit on the valve plate. The holding part and spring are full for the media to be discharged accessible. This mixture of propellant and prepolymer leaves the pressure container when the valve closure element is actuated and thereby reaches the area of the spring and its holding part. When the pressure on the valve closure element decreases, the spring presses it again against the valve plate, so that no further mixture can escape. Mixture that is still in the valve chamber is discharged through the propellant content.

Such poppet valves with spring mechanism are well suited for connection to spray guns. However, they have the disadvantage that the function of the spring is impaired sooner or longer or even blocked, because moisture diffuses into the valve mechanism and causes polymer formation. This means that the pressure vessel can either no longer be emptied in a controlled manner or leaks and blows off in an uncontrolled manner.

In a further version of these valves, sealing sections are provided on the circumference of the valve closure element. These have at least one elastically deformable, disk-shaped section which protrudes radially from the closure element and rests against the valve seat under deformation. Sealing and closure elements are made of one piece and consequently from one and the same material. For the deformation, these elements require a certain elasticity, which on the other hand limits the contact forces and reduces the tightness.

All of these valves have a rather complex structure with a multitude of details, including a rigid valve body that has to be mounted or molded onto the valve disk. For cost reasons, a simple structure with a reduction in the number of individual parts would be desirable.

The object of the invention is therefore to provide a valve which avoids the disadvantages of conventional valves described above. It is intended to protect against the ingress of moisture into the valve area in the pressure vessel. However, application aids such as spray guns must be able to be connected. It should have a simple structure and ensure high operational reliability. To achieve this object, the invention proposes starting from the valve of the type mentioned that the valve plate has a sealing surface designed as a valve seat, which cooperates with a sealing element, the valve plate and the sealing element made of rigid, non-functionally deformable material, and the Sealing effect is brought about by an elastic element arranged on the valve plate, and the spring element, which holds the sealing element in the closed position, is fixed directly on the valve plate.

The valve enables the pressure vessel to be connected to a conventional spray gun. Since the valve closure element moves in the direction of the pressure vessel axis through a valve stem, it can no longer impair its function by turning it off.

Because the valve closure element does not require any elastically deformable details for the seal, it can, like the valve disk, consist of rigid material. It is thus possible to dimension the contact forces required for the seal sufficiently and to transmit them via appropriate spring forces. The sealing function is performed by separate elastic elements that are designed for this task and have proven themselves for this purpose. On the other hand, the valve disk, from its uniform function as a cover for the pressure vessel and at the same time as a rigid valve body, also offers the necessary strength to absorb the contact forces on the valve seat surfaces.

The general construction concept described above also offers better solutions for the arrangement of the springs for resetting the movable valve element for closing the valve. It is thus possible to place spring elements completely outside the area where the hardening media emerge, namely within the side facing away from the pressure container in the valve plate. In this position, they act on the movable valve element with tensile forces in order to press it against the valve seat surface. In this case, even coil springs do not run the risk of their gears sticking, which would block their function. Another preferred solution provides for a leaf spring as an elastic spring element to be firmly connected to the valve disk on its side facing the pressure vessel. In this position you are in contact with the outflowing fluid, but here it is not in contact with media that lead to hardening. In addition, in terms of flow technology, they are in an area on the valve closure element that a medium tends to flow past. This situation is favored by the fact that no holding part for this spring element can lead to turbulent flow behavior in the critical area. Gluing or blocking is therefore impossible. In addition, leaf springs offer fewer or no starting points / areas for gluing by the foaming agent.

Further preferred embodiments of the invention are the subject of the subclaims, which will be discussed in more detail with reference to the attached figures. It goes without saying that the features and configurations shown or described in the preferred embodiments of the invention are not only of importance in the combination shown, but in any meaningful combination and design options which result from the entirety of the illustrations and the description provided here. Show from the pictures

1 shows a section through a valve with a two-part valve closure element and a coil spring arranged in the valve plate on the side facing away from the pressure container,

2 shows a section through a valve with a two-part valve closure element and a leaf or disc spring attached to the valve plate on the side of the pressure vessel,

3 shows a section through a valve with a one-piece valve closure part and a combination of spring and sealing element attached to the valve plate on the side of the pressure vessel; Fig. 4 is a sectional view of a further preferred valve design, in which the elastic element for sealing to an elastic and sealing

Guide element is expanded;

Fig. 5 shows a variant of the embodiment of Fig. 3; and

Fig. 5a is a perspective sectional view of the embodiment of Fig. 5;

Fig. 6 shows a valve according to the invention with a separate sealing element held by a leaf spring.

Fig. 1 shows a section through a valve according to the invention. The valve disk 1, 2 fulfills the functions as a container lid and as a valve body. For this purpose, it has a central opening 3 for the passage of the movable valve closure element 4, 5, valve seat surfaces 6 parallel to the correspondingly engaging sealing surfaces 7 on the valve closure element and a valve stem 8 for guiding the valve closure element. On its inner diameter, the valve stem serves as a sliding surface for the seal 16 which is pressed in between the two parts 4, 5 of the valve closure element. With its outer diameter, the valve stem also acts as a spring guide for a helical spring 9 which is connected to a shoulder 10 with a larger diameter from below part 4 of the valve closure element facing away from the pressure container. In this way, the spring forces pull and hold the movable valve element 4, 5 in its relaxed position against the valve seat in the position required for closing.

To open a pressure force must be applied from the outside to the movable valve element 4, 5, which counteracts the spring force. In this case, an annular gap 11 is free between the valve seat 6 and the sealing surface 7 on the valve closure element 4, 5. This allows the medium from the pressure vessel through the channels 12, 13, 14 introduced within the valve closure element and above its sealing surface and from there into or onto the targeted components or through a spray gun, not shown. Side A of the figure shows the open, side B the closed position of the movable valve element.

In this version, the two parts 4, 5 of the movable valve element are screwed, for example, via a thread 15. An O-ring 16 is pressed as a sealing element so that it lies sealingly on the valve stem 8. On the valve seat 6, an elastomer disk 17 is proposed for sealing. The seal against a spray gun, as shown here, can also be made by an O-ring 18. The two parts of the valve plate 1, 2 can be welded, glued, molded or directly, as shown in Fig. 2, drawn from a single piece. The edge 19 of the valve disk facing away from the pressure vessel, not shown here, is crimped for attachment to the same.

FIG. 2 shows a section through a valve according to the invention, which corresponds in some essential features to the valve shown in FIG. 1. The valve plate 1, 2 with its two functions as a cover for the pressure vessel and valve body is deep-drawn from one piece here. A reinforcing element 20 can be introduced for stiffening, in order to keep the thickness of the deep-drawing material within limits, as shown here. Another difference to the valve of FIG. 1 is the leaf spring 21, which is attached to the side of the valve disk 1, 2 facing the pressure vessel. The spring force brings and holds the movable valve element 3, 4 as a compressive force in the closed position. To open it, an external pressure is used to press the tongue 22, which is made of resilient material in the middle of the compression spring and is of a width appropriate for the valve closure element, into the interior of the pressure cell. As a result, the annular opening 11 shown on the side A of FIG. 2 between the valve seat 6 and the sealing surface 7 on the valve closure element is free for the medium to escape.

3 shows a further preferred embodiment of the invention, which is based on the fact that the valve plate 1 also serves as a valve body or guide 8 for the closure part 4 and with its section 6 as a valve seat for the sealing element 7. The valve plate 1 is flanged in the manner already described in its edge region 9, 10 for fixing to the dome of the pressure cell. The valve plate has a folded inner structure that ends in a tubular upwardly bent guide element 8. Stem 4 is mounted within guide part 8 and has an annular seal 18 mounted in a groove in its upper region. The ring seal is used to seal the system when connected to a conventional spray gun (connection elements not shown).

The actual sealing mechanism is based on the interaction of the horizontal section 6 of the valve plate 1 (valve seat 6), to which the underlying elastic element 17 is connected in the form of a perforated sealing washer. The sealing part 4 (stem) is guided through the sealing disk 17. Immediately below the sealing disk 17 is the horizontally projecting edge 31 of a spring element 30 which holds the valve in the closed position. Sealing disk 17 and edge 31 are crimped tightly and completely all around at 32 in a fold of the valve disk 1.

The spring element 30 has at its lower end a leaf spring or spring tongue 21 which presses the sealing element 7 against the sealing disk 17 and thereby brings about the final effect of the valve. Pins 33 of the sealing element 7 engage on the underside in the stem 4, so that there is a tight fit. The stem 4 additionally has one or more transverse bores 13 through which foaming agents can penetrate and exit through the channel running therein. Stem 4 and sealing element 7 together form the closure part 4th

The valve itself is actuated by pressing the closure part 4 down. The pressure is transmitted via the sealing element 7 to the spring tongue 21, which yields and releases an annular gap at 11 through which the foaming agent can enter the interior of the sealing element 7.

It goes without saying that the spring element 30 itself is not suitable for keeping the foaming agent away from the sealing element 7; it has one or more openings through which the foaming agent can freely pass. Fig. 4 shows a sectional view of a further preferred valve design, in which the elastic element 17 is expanded to form an elastic and tight guide element 16, in a sectional view with mutually offset sectional planes. The closure element 4 is made in one piece here, ie it comprises both the stem and the sealing element 7 in one component. A central channel 14 is open to the outside through lateral openings 13 in the lower region, so that the openings 13 become free when the stem 4 is moved downward into the pressure cell.

The valve disk 1 itself has an essentially horizontal region 6 as a valve seat, against which the elastic element 17 acts, and a vertically running guide region 8 which engages in a recess in the elastic body 16. The elastic body 16 itself is made, for example, of rubber or rubber and represents a cylindrical hollow body which is cut in the area of the guide 8. It has a substantially smooth inner surface, which seals against the outer wall of the star 4 and guides the stem 4 when the valve is actuated by being pressed in.

The sealing area or the sealing element 7 of the closure part 4 is held in the closed position via the spring tongue 21 of a spring element 30, i. H. a radially extending projection of the sealing element 7 presses against the lower edge of the elastic element 17, which in turn is supported against the valve seat part 6 of the valve plate 1.

In this case, the spring element 30 is positively locked in an S-shaped structure of the valve plate 1 (at 32).

The illustrated mode of operation makes it possible to manufacture the valve in a simple manner by first inserting the elastic body 16 into the valve plate 1, into which the stem 4 with the sealing element 7 is then inserted from below. Then the spring element 30 is latched from below into the S-shaped segment 32 of the valve plate 1 and held there in a positive and non-positive manner. Fig. 5 shows a further embodiment of the valve according to the invention with the stem 4, which together with the sealing element 7 forms the closure part and the valve plate 1, which here again with a guide 8 and a valve seat portion 6, against which the sealing element 7 via a sealing washer 17 acts, is formed. The stem 4 has in its lower region a transverse opening in the wall 13 through which foaming agents can enter the vertical channel 14 of the star 4. An O-ring 18 located in a groove serves as a seal against a gun adapter that can be connected in the upper region of the star 4.

As in FIG. 3, the sealing disk 17 is crimped to the valve disk 1 in this embodiment as well. In this embodiment, however, the spring element 30 is not crimped together, but rather a basket 38 with an edge 39 with the sealing disk 17, the basket 38 having openings 37 through which foaming agents can enter. In the basket, the spring element 30 is inserted in the bottom area, the spring tongue 21 of which projects upwards and acts against the sealing element 7.

The basket 38 has, on its inside, vertically extending webs 3, 4 which cooperate with an edge region 36 of the sealing element 7, which also extends vertically, in such a way that the sealing element 7 is guided on the basket 38.

The spring elements used in accordance with the invention are preferably made from conventional spring steel. The sealing elements 7 can be designed as metallic deep-drawn parts as well as precision molded parts made of plastic. The basket 38, as shown in Fig. 5 ^• , is preferably made of plastic.

FIG. 5a shows a perspective sectional illustration of the embodiment of FIG. 5, from which the interaction of the individual components becomes clear.

The embodiment according to FIG. 6 represents a variant of the embodiment according to FIG. 5, in which the sealing disk 17 is integrated in a sealing body 16. In the valve plate 1 with a valve seat part 6 and a guide tube 8, a sealing body 16 is seated, which is expanded radially in its lower region to form a sealing disk 17. The sealing body 16 has a projection in its upper region or a recess in the region of the guide part 8 of the valve plate 1 in the upper region. The part of the body 16 seated on the end of the guide tube 8 of the valve plate 1 is designed to be elastic under Pressure can escape to the outside.

The stem 4 of the valve, which together with the sealing element 7 forms the closure part, runs inside the sealing body 16. A radial projection in the upper area lies on the end of the sealing body 16. The stem 4 ends in a bottom part 39 which is fitted into the bowl-shaped or trough-shaped sealing element 7. A circumferential radial projection 40 lies sealingly on the sealing disk 17.

The lateral openings 13 have the shape of a triangle standing on the top, so that when the stem 4 is pressed in, a very precise metering of the amount of foam-forming agent that is released is possible. First, only the lower, tapering region of the openings 13 becomes free, which greatly limits the amount of passage and exit. If the stem 4 is only partially pressed in, only the lower part of the cross section of the openings 13 becomes free, so that only a relatively small amount of foaming agent can escape. If the stem is pushed in further or completely, the area of the openings 13 that is released increases and thus the delivery capacity of the valve.

As in FIG. 4, the spring element 30 is also fitted with its flanged ends 31 into an S-shaped structure 32 of the valve plate 1 in a positive and non-positive manner in this embodiment. A spring tongue 21 projects upwards and presses against the bottom of the sealing element 7, which seals with its upper edge against the radial widening 17 of the sealing body 16. It is understood that the spring element 30 has openings or openings through which the foaming agent can freely enter the space above the spring element. The valves according to the invention can be used for all forms of pressure cans with foaming agents, but are primarily suitable for one-component systems. The associated pressure sockets are of conventional design and do not require any further adaptation to the special features of these valves.

It is understood that one of the peculiarities of the valves according to the invention is that the valve disk 1 also takes over the function of the rigid valve body present in conventional valves. Therefore, in addition to the closure part, which is usually formed from the stem and the sealing element, but can be formed in one piece as well as in two pieces, only an elastic element is required, which is mounted between the valve seat and the sealing element and for the actual sealing effect responsible for. The elastic element is designed in particular as a sealing washer and is preferably secured by flanging, crimping or jamming on the valve plate 1 in the region of the valve seat 6.

- Expectations -

Claims

claims

1.Valve for dispensing foaming agents from pressure vessels, which closes the pressure vessel to the outside and has an outlet opening with a movably arranged closure part (4) which is held in the closed position by a spring element (21) and an outlet opening for the by external actuation releases foaming agent present in the pressure container, the valve being mounted on a container cover designed as a valve plate (1), characterized in that the valve plate (1) has a sealing surface designed as a valve seat (6), which cooperates with a sealing element (7), the The valve disc (1) and the sealing element (7) consist of rigid material that is not functionally deformable, and the sealing effect is brought about by an elastic element (17) arranged on the valve disc (1), and the spring element (9, 21, 30), which keeps the sealing element (7) in the closed position telbar on the valve plate (1) is fixed.

2. Valve according to claim 1, characterized in that the movable closure part (4) by. Train a coil spring (9) is brought into the closed position and held, the spiral spring (9) being supported against a shoulder (10) of the closure part (4).

3. Valve according to claim 1, characterized in that the movable closure part (4) is brought and held in the closed position by pressure of a spring tongue (21), the spring element (30) being fixed on the inside of the valve plate (1).

4. Valve according to claim 3, characterized in that the spring element (30) are positively and / or non-positively fixed on the inside of the valve plate (1).

5. Valve according to claim 4, characterized in that the spring element (30) is fixed by crimping or clamping on the valve plate (1).

6. Valve according to one of the preceding claims, characterized in that the elastic element (16, 17) is a sealing body or a sealing washer.

7. Valve according to claim 6, characterized in that the

Sealing disc (17) between the valve seat (6) and the sealing element (7) is arranged.

8. Valve according to claim 6, characterized in that the sealing body (16) in an inner cylindrical extension of the plate (1) is fitted and is held over upper and lower radial extensions, the lower radial extension with the valve seat (6) and the sealing element (7) cooperates sealingly.

9. Valve according to claim 7, characterized in that the sealing disc (17) is fixed by crimping or clamping on the valve plate (1).

10. Valve according to one of the preceding claims, characterized in that the closure part (4) comprises a valve stem and the sealing element (7) and is formed in one or two pieces.

11. Valve according to one of the preceding claims, characterized in that the foot of the closure part (4) to form the

Sealing element (7) is expanded radially.

12. Valve according to claim 10, characterized in that the sealing element (7) is a separate molded part which acts on the valve seat (6) via the elastic element (17).

13. Valve according to claim 12, characterized in that the sealing element (7) is a bowl-shaped metal molded part which is held in the closed position by a spring tongue (21) acting against the bottom.

14. Sealing element according to one of the preceding claims, characterized in that the closure part (4) has an internal longitudinal bore which ends in radially extending bores or channels.

15. Valve according to claim 14, characterized in that the

Cross-sectional openings have the shape of a triangle standing on top.

16. Valve according to one of the preceding claims, characterized in that the valve plate (1) is also designed as a valve guide (8) for the closure part (4, 5), the guide (8) of the valve plate (1) as a central tubular element is formed, in which a cylindrical sealing body (16) is fitted, the base of which widens radially to form a sealing disk (17).

- Summary -