NL1033110C2 - Coupling system for bringing pneumatic or hydraulic steering components together in a flow connection. - Google Patents

Description

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Brief indication: Coupling system for bringing pneumatic or hydraulic control components together in the flow connection.

The present invention relates to a coupling system for bringing pneumatic or hydraulic control components together in flow communication, in particular in the process industry.

5 Many pneumatic and hydraulic control components such as pressure regulators, filters, non-return valves, taps, valves, etc. are factory-fitted with connection ports with internal threads. For economic reasons, it is therefore preferable to use this to connect the control components. However, as soon as the ports are provided with conical threads, the problem arises that the screw-in depth and thus the distance between the control components can vary. At the same time, a fixed position of the steering components is usually desirable. Determining the position on the spot is an outdated method with the current state of the art. A major disadvantage of using the conical, whether or not sealing, screw thread is the screw-in depth of the coupling. This varies depending on the tolerances on the thread. NPT threads are used predominantly in the process industry. The tolerance at screw-in depth is approximately +/- 1 turn per thread. The deviation can therefore double per screwed-in coupling. If sealing tape is used, the variation can become even greater.

If two parts are coupled by means of two screw-in couplings which are connected to each other at a fixed distance, the variation in distance between the control components is therefore possibly some turns. It is often desirable to screw the control components onto a carrier. Certainly if several control components are coupled, the question is whether it is desirable for the couplings to also be load-bearing. Screw-in couplings that make use of the existing connection ports cannot actually record moments that work around the axis of the connection. They could then loosen. In addition, they are not designed to support (heavy) steering components.

1033110 - 2 -

An alternative is the use of coupling blocks that are placed between the control components. The control components and / or coupling blocks must then be provided with chambers for, for example, 5 o-ring seals and in line with this (screw connections) to which the control components and the coupling blocks are connected. Often the last possibility is missing or there is no room for it

Known pneumatic or hydraulic control units for operating an actuator often comprise several control valves, a pressure reducing valve, a filter unit, etc. as control components. These control components are then, for example, mounted on a wall plate, wherein connecting piece bevel is screwed into the connection ports of the control components. These connecting pieces are in turn connected by means of, for example, a compression coupling to flexible hoses or suitably bent rigid pipelines. They thus form a coupling and flow connection between the control components.

A disadvantage here is that such a control unit takes up a lot of space, is labor-intensive to manufacture, and is particularly susceptible to damage at the couplings, as a result of which leakage can occur.

In other known pneumatic or hydraulic control units for operating an actuator, the control components are directly connected to each other, and thereby come to lie virtually against each other. Mounting on a wall plate then often does not take place. The coupling consists, for example, of a connecting piece which can be screwed with its both ends into the connecting ports of a control component so as to bring it into flow communication with each other. In addition, sometimes additional connecting elements, such as tie rods, are provided between the control components in order to provide the unit with sufficient rigidity.

A disadvantage here is that the assembly of control components and couplings is not very flexible, often requires additional connecting elements, and is difficult to access. If no additional connecting elements are used, the stiffness of the construction must be taken from both the control components and the connecting pieces. This places high demands on the connection pieces and the '' - 3 -

The present invention has for its object to at least partially obviate the aforementioned disadvantages, or to provide a useful alternative.

This object is achieved by a coupling system according to claim 1. Pneumatic or hydraulic control components can now advantageously be coupled easily with a fixed distance between them. The medium is guided by the coupling parts that are screwed into the connection ports of the pneumatic or hydraulic control component. Both the screw-in depth and the position of these parts are no longer important here. The sliding coupling does not have to perform a carrier function with much advantage. A separate mechanical connection between the control components is sufficient. The coupling system thus provides a widely applicable connection option for control components. A control component is to be understood to mean a component through which a medium can be passed and with which the flow can be influenced or the properties thereof can be monitored or measured. This includes a control valve for shutting off the fluid flow or not, a pressure reducing valve for reducing or not reducing the fluid pressure, a filter unit for filtering the fluid, pressure gauges, etc.

Because the steering components can be fixed, and the sliding coupling offers freedom of movement, a robust and reliable system can still be provided with few parts and minimal assembly work. The system requires little space, can be used immediately and has a greatly reduced risk of leakage. Temperature differences can also be absorbed well by the system.

An additional advantage is that it is now possible to provide a fixed distance between the connection ports of the control components. This makes it possible to record the complete position of the 30 control components. This without having to make use of space-consuming flexible elements such as hoses. An alternative is the use of control components with special or non-standard special connection ports for use on associated base plates. One side of the control component is then mounted on a support, for example screwed onto a base plate. This works especially well if control components are connected in parallel.

The control components can now advantageously be mounted on fixed positions on the carrier. This can, for example, occur at predetermined intermediate distances. It is thus possible to provide the carrier with a standard pattern of mounting points. Mounting slots or the like are no longer required. Also with regard to the mounting positions there is advantageously no dependence on tolerance differences in the threaded connection between the control components 5 and the coupling parts. It is therefore always possible to obtain a reliable sealing thread connection.

The threaded connection need very much no longer be broken in the case of maintenance, replacement and the like, because the sliding coupling itself can be disassembled. This is particularly advantageous with stainless steel threaded connections, because otherwise they can be damaged quickly. The steering components are therefore easily exchangeable at all times.

Further preferred embodiments are defined in the subclaims.

The invention also relates to an assembly of a carrier and a coupling system according to claims 16 and 17, as well as to a use of the coupling system according to claims 18-20.

The invention will be explained in more detail below with reference to the accompanying drawings, in which:

FIG. 1 shows a first embodiment with two coupling parts;

FIG. 2 shows a preferred embodiment with an external tube; FIG. 3 shows a third embodiment with an internal tube;

FIG. 4 shows a variant of FIG. 2 with an additional connection;

FIG. 5 shows a variant of FIG. 2 with a cartridge;

FIG. 6 shows a variant of FIG. 2 with a non-return valve; and

FIG. 7 shows an application for the process industry.

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Figure 1 shows a kind of minimal design in which the sliding coupling consists of two screw-in coupling parts (3) that can slide over each other. The (dis) assembly of the screw-in coupling parts (3) can take place by using a tool which engages on an internal or external hex or on for instance two flat sides.

The pneumatic or hydraulic control components (2) are represented in simplified form as rectangular blocks. With screws (1) they are fixed on a support (4), this can for example be a thick machine or device. The screw-in coupling parts (3) can move axially relative to each other and rotate about each other because they are provided with a sliding fit. The seal is obtained by an elastic element such as an o-ring (5). Of course, several control components can be connected to each other in series.

Figure 2 shows the sliding coupling consisting of two screw-in parts (3) and an external tube (6). The two screw-in parts (3) seal against the inside of the tube (6) by means of an elastic seal (5). Shown is the situation in which the tube (6) rests on both sides against the control components (2). The length of the tube (6) is chosen such that it corresponds to the desired fixed distance between the control components (2). Also, the tube (6) is now advantageously limited on both sides, so that it always remains in sealing contact with the seals (5). The length of this coupling can easily be varied by changing the length of the tube (6). The tube (6) can absorb pressure forces. This is the case if the pressure of the medium in the coupling is lower than the ambient pressure. Figure 2 shows an asymmetrical variant with a larger and smaller wire connection. In a variant, the tube can also be chosen shorter than the desired fixed distance between the control components. The tube then has the freedom to slide back and forth to some extent or to accommodate expansion of the coupling.

Alternatively, it is possible to construct a coupling with an internal tube (6), see figure 3. However, the tube (6) will then be able to slide back and forth to some extent in the screw-in parts (3).

Especially the externally applied coupling tube is favorable, it is axially secured between the control components and offers better possibilities for expansion.

If the coupling tube (6) is extended, it offers the option of making additional connections. Figure 4 gives an example of a T connection. The rotation freedom of the branch is attractive. This can be rotated 360 ° and can be positioned in the most optimal position, so that any stresses are reduced. It is of course possible to create several branches with internal or external thread or, for example, compression fittings or a welding connection. The arrows indicating the flow direction are drawn randomly.

The tube offers the option of sliding or placing separate sub-control components in 40. For example, it is possible to slide non-return valves, pressure control valves, restrictions or combinations of these into the tube (6) as a 'cartridge'. Securing may be necessary and may for example take place with securing rings in the tube. Figure 5 gives an example of such a cartridge, without the precise functionality being indicated. The cartridge (7) is provided with an elastic sealing element (8) and secured with two securing rings (9). This provides a more compact assembly with much advantage.

Some sub-control components can be placed directly in the tube, for example a non-return valve (10) as shown in figure 6. The precise opening pressure depends on the screw-in depth of the screw-in parts (3). This disadvantage does not have to outweigh the advantage of a lower cost price.

The medium can only flow in the direction of the arrows. The non-return valve (10) is then pressed open against the force direction of a spring (11). In the drawn, closed state, an elastic sealing element (12) ensures sealing. Perhaps it is possible to further limit the number of components. The drawing only gives an indication of the operating principle.

Cranes belong to frequently used sub-control components.

These can also be integrated in the coupling tube. As with the T-piece, the control knob can be rotated 360 ° around the axis of the coupling tube.

Figure 7 gives an example of a practical application for the process industry. A manifold has been drawn for operating a single-acting pneumatic cylinder (spring return) which, in turn, operates a large butterfly valve in an installation. The supplied compressed air is filtered and reduced in pressure by a filter regulator (15). One or two 3/2 solenoid valves (16) (as shown) serve as control valves and direct the air to the cylinder or vent the cylinder. The air is then blown off by dampers (17). If the pressure of the supplied compressed air suddenly drops, a non-return valve arranged in a sliding coupling (18) according to the invention can prevent the pressure in the cylinder from falling away. The unwanted displacement of the cylinder can thus be prevented. The pneumatic control components are screwed onto an omega-shaped profile (19). Of course several configurations are possible such as · ί «ΛΛνΚΛΩΐ ^ Virtf -f-mot u v * ör \ rran rlnKKö 1 uor ΙτδπγΪλ 1 ΐ n / loro ^ ^ - 7 -

In addition to the embodiments shown, many variants are possible. Thus, the coupling parts and / or the parts that can be slid in axial direction relative to each other can be of different design. Advantageously, the freedom of movement in the axial direction that the parts slidably engaging in the axial direction are larger than 0.3 cm, in particular greater than 0.5 cm. This freedom of movement is mainly determined by the minimum and maximum overlap that the two parts can have with each other, measured from the sealing member. The sliding coupling 10 is advantageously arranged such that the freedom of movement in the axial direction of the parts slidably engaging in the axial direction is greater than the axial length of the connecting parts of the coupling parts, for example the part that comes into recess after coupling with the control component therein. to lay down. This makes it possible to arrange the sliding coupling between the control components after these control components have already been mounted in fixed positions relative to each other. Namely, the sliding coupling then fits into the collapsed position between the control components, after which the coupling parts can be connected to the connecting ports by screwing in.

Furthermore, the sealing members can also be provided in the inner circumferential wall surfaces with the opposite parts. The coupling parts can also be made of plastic, metal or other materials.

The parts of the sliding coupling which slide slidably into each other in the axial direction preferably engage with a close fitting fit and can thereby rotate relative to each other about the longitudinal axis. If desired, however, a clearance between the parts can also be provided and / or a rotation limit.

The thread on the coupling parts is preferably formed by a conical thread, in particular so-called NPT thread. These screws advantageously clamp themselves in the threaded connection ports during screw-in.

The coupling system according to the invention lends itself particularly well for use in the process industry, for example as a control unit for operating an actuator. In particular, the coupling system of control components and slide couplings forms a control unit for controlling a piston-cylinder system with which a valve in a process flow line can be opened and closed. To this end, the control unit comprises at least one control valve and a filter unit as control components.

Thus, a user-friendly / inexpensive coupling system is provided that can be easily assembled and disassembled without having to take on excessive forces and without standing in the way of mounting the pneumatic or hydraulic control components at fixed positions.

Claims (20)

Coupling system for bringing pneumatic or hydraulic control components (2), in particular in the process industry, into flow communication, comprising: - at least two pneumatic or hydraulic control components (2) provided with connection ports (2 '); a coupling adapted to establish a flow connection between two adjacent connection ports (2 '); wherein the connection ports (2 ') and the coupling are provided with complementary thread parts (3'), characterized in that the coupling comprises at least two separate coupling parts (3) which are each adapted to be provided by means of the complementary thread parts (3 ') to be connected to one of said connection ports (2 '), wherein the coupling is a sliding coupling which comprises at least two parts slidably engaging in axial direction, wherein at least one sealing member (5) is provided between the slidable in each other interlocking parts. 2. Coupling system as claimed in any of the foregoing claims, wherein the control components (2) are provided with fastening means (1) for fixing the control components (2) on a carrier (4), without thereby coupling the coupling parts (3) themselves to fix each other. 3. Coupling system as claimed in any of the claims 1-2, wherein the parts slidably engaged in axial direction are formed by said coupling parts (3) which are adapted to be connected to one of the parts by means of the complementary thread parts (3 '). said connection ports (2 '). 30 Coupling system according to one of claims 1-2, wherein the sliding coupling further comprises an additional coupling element (6) which slidably engages with said coupling parts (3) which are adapted to be connected by means of the complementary thread parts 35 (3 ') connected to one of said connection ports (2 '), and wherein the sealing members (5) are provided between the coupling parts (3) and the additional coupling element (6). 033110 - 10 - Coupling system according to claim 4, wherein the additional coupling element (6) is an internal or external tubular element. 6. Coupling system according to one of claims 4-5, wherein the additional coupling element (6) is provided with a branch. 7. Coupling system according to any of claims 4-6, wherein the additional coupling element (6) accommodates a sub-control component, such as a non-return valve (10), pressure regulating valve, restriction or combination thereof. Coupling system according to claim 7, wherein the sub-control component is accommodated in a cartridge (7). 9. Coupling system as claimed in any of the claims 4-8, wherein the additional coupling element comprises a tap. 10. Coupling system as claimed in any of the foregoing claims, wherein the parts 20 slidably engaged in axial direction engage one another with a sliding fit. 11. Coupling system as claimed in any of the foregoing claims, wherein the parts slidably engaging in axial direction also rotatably engage each other. 25 12. Coupling system as claimed in any of the foregoing claims, wherein the coupling parts (3) which are adapted to be connected by means of the complementary thread parts to one of the said connection ports (2 ') are provided with conical thread parts, in particular NPT thread . 13. Coupling system according to one of the preceding claims, wherein the coupling parts (3) which are adapted to be connected by means of the complementary thread parts (3 ') to one of the said connection ports (2') are provided with an external or internal profiling which tools can engage. 14. Coupling system according to one of the preceding claims, The coupling system of claim 14, wherein the control components (2) further comprise a filter unit (15). Assembly of a carrier (4) and a coupling system according to one of the preceding claims, wherein the at least two pneumatic or hydraulic control components (2) are fixedly connected to the carrier (4), the at least two separate coupling parts (3) ) establish a flow connection between the two adjacent connection ports (2 '), and for this purpose each being connected by means of the complementary threaded parts (3') to one of the said connection ports (2 '), the at least two slidable in axial direction interlocking parts engage as a sliding coupling under seal by means of the at least one sealing member (5) provided between the slidingly engaging parts of the sliding coupling. 17. Assembly as claimed in claim 16, wherein the control components (2) are provided on the carrier 20 (4) at fixed intermediate distances from each other. Use of a coupling system according to one of the preceding claims in the process industry. Use of a coupling system according to one of the preceding claims in a control unit for operating an actuator. 20. Use according to claim 19, wherein the actuator is a piston-cylinder system for opening and closing a valve in a process flow line. 033110