WO1997009559A1

WO1997009559A1 - Valve

Info

Publication number: WO1997009559A1
Application number: PCT/DK1996/000366
Authority: WO
Inventors: Jens Jørgen NIELSEN; René Andersen; Erik Haugaard; Lars Bjarne Hilbrecht; Anders Valbjørn; Helge B. Nielsen
Original assignee: Danfoss A/S
Priority date: 1995-09-05
Filing date: 1996-09-04
Publication date: 1997-03-13
Also published as: DE19532712A1

Abstract

A valve (1) is disclosed, having a channel (2) which, at at least one end, forms a valve connection (32, 33) and which has in its circumferential wall at least one opening (7, 8), and having a valve element which influences the pressure and/or the flow in the valve (1). It is desired to manufacture such a valve inexpensively whilst nevertheless ensuring a reliably operating construction. For that purpose, the circumferential wall is externally flattened in the region (4) of the opening (7, 8).

Description

Valve

The invention relates to a valve having a channel which forms a valve connection at at least one end and which has at least one opening in its circumferential wall, and having a valve element which influences the pressure and/or the flow in the valve.

The opening in the circumferential wall of the channel can be used to introduce the valve element into the channel in order to influence flow through the channel. The opening can also be used to divert part of the fluid flowing through the channel and, for example, to hold the pressure in the outflowing fluid at a predetermined value. In each case it is necessary for the valve element and, if desired, the parts which control, drive or adjust the valve element, to be securely and reliably fastened to the channel. Moreover, the fastening must, of course, be effected so that, as far as is possible, no sealing problems arise. That requires a certain trouble in manufacture which makes such valves relatively expensive. On the other hand, it should also to be possible to connect the channel to a conduit in which the fluid flow or the pressure of the fluid is to be controlled. Connecting flanges are often used for that purpose, and their manufacture and mounting also involve not inconsiderable cost, which is a particular disadvantage when the valve is one which is to be manufactured in large piece numbers. The invention is based on the problem of providing a valve that is inexpensive to manufacture and allows a reliably operating construction to be achieved.

In a valve of the kind mentioned in the introduction, that problem is solved in that the circumferential wall is externally flattened in the region of the opening.

Thus, in the region of the opening, a flat bearing surface is available, to which a valve arrangement can be secured. The term "valve arrangement" is intended to include all the elements that are used to hold, control, adjust or otherwise influence the valve element. The valve arrangement comprises also the valve element itself and, optionally, a fluid path which branches off the channel. The flat form of the outside of the channel renders sealing between the channel and the valve arrangement relatively simple. In many cases it is sufficient for a seal, which is likewise flat, to be arranged between the channel and the part of the valve arrangement lying adjacent to the channel. Thereafter, channel and valve arrangement require merely to be pushed with the necessary force against each other in order to achieve a sealed connection. A level or flat seal is inexpensive. No special skill is required to mount it. The valve can therefore be manufactured relatively cheaply. Nevertheless, its construction is such that it can operate reliably.

In an especially preferred construction, provision is made for the channel to be formed by a pipe of circular cross-section, the wall of which is deformed in the region of the opening. Pipes of circular cross-section have the advantage that they are able to withstand a relatively large pressure load. If the deformation is restricted to the region of the opening, relatively efficient valves can be made with such a pipe. The deformation can be achieved in a simple manner, for example, by inserting the pipe in a forming tool which has the desired finished appearance of the channel. If the inside of the pipe is then put under pressure, for example, by means of a hydraulic fluid, then the pipe is deformed outwardly in the regions in which the forming tool permits, and assumes the desired shape. The forming tool requires merely to be provided with a flat abutment face for the material of the pipe in order to achieve the desired deformation of the pipe.

Preferably, in the region where it is deformed the pipe has at least approximately the same wall thickness as in its remaining region. This can be arranged, for example, in that, in its deformed region, the pipe has approximately the same cross-section as in its circular region. Weakening of the pipe as a result of the deformation is thus largely avoided. The pipe, and with it the valve, retain their ability to withstand pressure.

In the region of its opening the channel advantageously has a cross-section in the form of a polygon. In this manner not just a single surface against which the valve arrangement lies is made flat; on the contrary, further surfaces are likewise in the form of flat surfaces. These can then be used, for example, for mounting purposes. In particular, it is possible to secure the valve arrangement with greater precision if there is on the channel a further surface that has a defined position relative to the surface against which the valve arrangement lies. In that case it is especially preferred for a flattening to be provided, parallel to the flattened region of the circumferential wall, on the opposite side of the channel. This flattening can be used, for example, to clamp the valve arrangement firmly to the flattened region. Alternatively, it can be used as a reference surface for the working of the valve arrangement itself.

That is, in particular, advantageously the case when a second opening is provided in the flattening. This second opening enables, for example, a second valve function to be created opposite the first valve arrangement.

It is also preferred for an adjusting device for the valve element to be passed through the second opening. Because the flattening runs parallel to the flattened region of the circumferential wall, the adjusting device for the valve element can be moved without difficulty relatively accurately in the direction of movement of the valve element when that valve element is moved likewise at right angles to the flattened region, as is often the case. This enables, firstly, a relatively long service life to be achieved, because the forces that occur are merely forces that are easy to absorb because they are able to be predicted in advance. Secondly, a relatively accurate adjustment of the valve element can also be effected.

Preferably, at least one of the two openings is arranged in the flow path between an input and a controlled output. This is, in particular, advantageously the case when the valve is to be used as a volume controlling valve. The volume to be controlled, which is to be kept constant, for example, can then flow out of the channel through the opening.

Preferably, a part of the valve arrangement projecting beyond the circumference of the pipe is at least partially covered by a housing extension which is in the form of a deep-drawn part. On the one hand this provides protection for the valve arrangement, and on the other hand the costs are not appreciably increased because such deep-drawn parts can be manufactured relatively cheaply.

In an especially preferred construction, provision is made for several openings with valve arrangements to be provided in succession, viewed in the longitudinal direction of the channel. It is therefore possible to feed several loads from one channel or to influence pressure or flow conditions in the channel at several points separately.

In that case it is especially preferred for the openings to be arranged in individually deformed regions of the channel, which are separated by sections of the channel of circular cross-section. The resistance to pressure of the channel is thus not appreciably affected. Between the individual deformed regions, at which valve arrangements are then located and which in turn contribute to stabilization of the channel, the channel has a circular cross-section, which, as explained above, already has a relatively high inherent resistance to pressure.

The valve elements are advantageously arranged in respective valve arrangements which have an outlet channel which runs substantially transverse to the channel and, optionally, in an offset plane. The output channels can then lead off the channel without obstructing one another or being obstructed by adjacent valve arrangements.

In a preferred construction, provision is made for the channel and the valve arrangements to be surrounded by cast plastics material. In this manner firstly a smooth exterior of the valve is achieved. In particular in regions in which the valve is exposed to contamination, and such contamination is undesirable (e.g. where foodstuffs are involved), this has great advantages. Moreover, the plastics material can also serve to increase the resistance to pressure of the valve as a whole. In this manner the dimensions of the wall thicknesses of the channel and also of the materials used for the valve arrangement can be made relatively weak.

The channel advantageously has a pipe coupling at at least one end. Such a pipe coupling can be formed, for example, through co-operation of a cone with a union nut. Such a pipe coupling can be pushed onto the end and facilitates quite considerably the mounting of such a valve in a conduit.

The invention is described hereinafter with reference to a preferred embodiment. In the drawings:

Fig. 1 shows a diagrammatic cross-section through a valve constructed as a volume controlling valve,

Fig. 2 is an external view of the valve looking in the direction of arrow II from Fig. 1, and

Fig. 3 shows a valve combination of several valves. A valve 1, which in the embodiment illustrated is in the form of a volume controlling valve, has a channel 2 which is formed from a pipe 3 of circular cross- section, which can be seen from Fig. 2.

The pipe 3 is deformed in a section 4 thereof so that it has a rectangular or square cross-section, which can also be seen from Fig. 2.

In the section 4 , the channel 2 therefore has a first flattening 5 which lies opposite a second flattening 6 on the other side of the channel 2. In each flattening there is an opening 7, 8 through which a valve arrangement 26, described in further detail hereinafter, is in communication with the inside of the channel 2.

The valve arrangement 26 comprises first of all a valve element 9 having a conical closure member 10 which co¬ operates with a valve seat 11. The valve seat itself is formed by a circumferentially arranged projection 12 of a plate 13, which can be formed, for example, by deep-drawing. The projection 12 projects through the opening 7. The plate 13 bears via the intermediary of a seal 14 against the flattening 5. A cylinder 16, in which a piston 17 moves back and forth, is secured to the plate via the intermediary of a further seal 15. The piston 17 covers openings 18 to a greater or lesser extent. It is moved by a spring 19 into the open position. The force of the spring 19 is opposed by a pressure from the channel 2 which passes by way of a conduit 20 to the side of the piston 17 remote from the spring 19. The openings 18 are in communication with an outlet chamber 21 which is surrounded by a housing extension 22 and is connected to an outlet channel 23. By means of an adjusting screw 24, which acts by way of a tappet 25 on the valve element 9, the distance of the closure member 10 from the valve seat 11 can be adjusted. In this manner the volume of fluid that flows from the channel 2 into the outlet channel 23 can be adjusted. In the outlet channel the volume of fluid should be kept as constant as possible, to be precise, as far as possible independent of the pressure in the channel 2 between its valve connections 32, 33. When the pressure in the channel 2 increases, the piston 17 is displaced so that it covers more of the openings 18. The operating principle of such a volume controlling valve is known per se and need not be discussed here in greater depth.

It is clear however, that by virtue of the parallelism of the two flattenings 5, 6 a force that acts through the adjusting screw 24 at right angles to the flattening 6 can also be transferred directly to the valve element 9 lying opposite. In this manner a relatively accurate setting of the valve element 9 is possible. The adjusting screw 24 is likewise guided in a housing extension 28 which bears against the flattening 6 of the channel 2 through the intermediary of a seal 29.

Fig. 2 shows a further advantage of the flattenings 5, 6 oriented opposite and parallel to one another. The two housing extensions 22, 28 can be pressed, using clamp screws 27, relatively easily yet securely against the two flattenings 5, 6, thus achieving the desired seal. This provides on the one hand a defined position of the valve arrangement 26 with respect to the channel 2, and on the other hand a simple mounting facility. The dashed lines in Figs 1 and 2 indicate that the complete valve 1 can also be surrounded by cast plastics material 30, so that externally the valve has only smooth surfaces which can easily be kept clean. Moreover, this plastics material 30 can also be used to increase the ability of the valve 1 to withstand pressure.

Fig. 3 shows diagrammatically a valve arrangement 51 having three valves 1 which are arranged on a common channel 2. For that purpose the channel 2 has three widened sections 4 of substantially square cross- section which are separated by sections 31 of circular cross-section. Each of these sections 4 can in principle look like the one illustrated in cross- section in Fig. 1.

Unlike the illustration in Figs 1 and 2, the outlet channel 23 of each valve 1 is rotated through 90° so that it runs transverse to the channel 2 and, in the embodiment illustrated in Fig. 3, also in a plane offset in relation thereto. The outlet channels 23 do not therefore obstruct one another and are also not obstructed by adjacent valves 1.

At the left-hand end of the channel 3 a pipe coupling 52 formed from a conical ring 53 and a union nut 54 is illustrated diagrammatically. When the appropriate complementary elements are provided on a conduit to which the channel 2 is attached, a sealed connection can be produced with simple means and little effort.

The embodiment illustrated can be modified in many respects. The valve can be used a pressure-limiting valve. Further valve elements can also be mounted on the walls of the section 4 running at right angles to the flattenings 5, 6. A further valve arrangement can be mounted in place of an adjusting screw 24. The channel 2 need not be a through-channel. It can be closed at one end. Also, the adjusting screw 24 can be provided on a flattening which runs at right angles to the flattening 5. In that case the valve arrangement can have a different function. A slider member which changes the flow cross-section of the channel 2 can be passed through the opening 7 or 8. Instead of the rectangular form of the cross-section in the section 4 , a hexagonal or octagonal cross-section can be used. The interposition of a seal 14, 29 can be omitted, if desired, if the corresponding extension parts are self- sealing, for example, because they are made of a material that is sufficiently resilient. In place of the clamp screws 27, a quick-acting closure can be used. The clamp screws 27 can also be omitted entirely if the sealing engagement of the relevant parts is ensured by the plastics material cast around them. This may be the case in particular when the plastics material 30 contracts as it hardens.

Claims

Patent Claims

1. Valve having a channel which forms a valve connection at at least one end and which has at least one opening in its circumferential wall, and having a valve element which influences the pressure and/or the flow in the valve, characterized in that the circumferential wall is externally flattened in the region (4) of the opening (7, 8).

2. A valve according to claim 1, characterized in that the channel (2) is formed by a pipe (3) of circular cross-section, the wall of which is deformed in the region (4) of the opening (7, 8).

3. A valve according to claim 2 , characterized in that, in the region (4) where it is deformed, the pipe (3) has at least approximately the same wall thickness as in its remaining region.

4. A valve according to one of claims 1 to 3 , characterized in that, in the region of the opening (7, 8) the channel (2) has a cross-section in the form of a polygon.

5. A valve according to one of claims 1 to 4, characterized in that a flattening (6) is provided, parallel to the flattened region (5) of the circumferential wall, on the opposite side of the channel (2) .

6. A valve according to claim 5, characterized in that a second opening (8) is provided in the flattening (6) .

7. A valve according to claim 6, characterized in that an adjusting device (24, 25) for the valve element (9) is passed through the second opening (8) .

8. A valve according to claim 6 or 7, characterized in that at least one of the two openings (7, 8) is arranged in the flow path between an input and a controlled output (23).

9. A valve according to one of claims 1 to 8, characterized in that a part of the valve arrangement (26) projecting beyond the circumference of the pipe (3) is at least partially covered by a housing extension (22) which is in the form of a deep-drawn part.

10. A valve according to one of claims 1 to 9, characterized in that several openings with valve arrangements (26) are provided in succession viewed in the longitudinal direction of the channel (2) .

11. A valve according to claim 10, characterized in that the openings are arranged in individually deformed regions (4) of the channel (2), which are separated by sections (31) of the channel (2) of circular cross- section.

12. A valve according to claim 10 or 11, characterized in that the valve elements (9) are arranged in respective valve arrangements (26) which have an outlet channel (23) which runs substantially transverse to the channel (2) and, optionally, in an offset plane.

13. A valve according to one of claims 1 to 12, characterized in that the channel (2) and the valve arrangements (26) are surrounded by plastics material (30) .

14. A valve according to one of claims 1 to 13, characterized in that the channel (2) has a pipe coupling (52) at at least one end.