WO2000028291A1

WO2000028291A1 - Sealing feedthrough support for tubular sheathed conductors and hollow conductors

Info

Publication number: WO2000028291A1
Application number: PCT/CH1998/000474
Authority: WO
Inventors: Harry Lehner-Meier
Original assignee: Max Lehner & Co. Ag Maschinen & Apparatefabrik
Priority date: 1998-11-06
Filing date: 1998-11-06
Publication date: 2000-05-18
Also published as: AU9733198A

Abstract

The invention relates to a feedthrough support (1) for a tubular sheathed conductor (3), if necessary combined with an electric terminal (14), especially for sheathed conductors of thermoelements or heat elements or for hollow conductors of measuring leads. The inventive feedthrough support (1) consists of a cylindrical main body (5) and a ring (7) which juts out from said main body. The main body (5) slides onto the sheathed conductor (3) or hollow conductor and can be connected thereto by means of a welded or soldered joint (9), peripheral pressure grooves (10), or an adhesive bond (33), or a combination thereof. This also serves as a seal between the outer surface of the sheathed conductor (3) and the inner surface of the feedthrough support (1) or seal (31). The feedthrough support (1) or seal (31) can therefore be mechanically sealingly connected to a feedthrough (24) or a feedthrough device (17) with the ring (7) without this attachment having mechanical effects and influencing the sheathed conductor (3) or hollow conductor.

Description

Sealing bushing for tubular sheathed conductors and waveguides.

The present invention relates to a bushing for tubular sheathed conductors according to the preamble of claim 1, the use of bushings of this type and a lead-through device and a bushing.

These are essentially sheathed conductors for the production of thermocouples, heating elements and measuring lines, as well as tubular, conductive hollow bodies, also called semiconductors, which are used for transporting, in particular for guiding and channeling media.

In the case of sheathed conductors or hollow conductors which are to be led from one room to another, the temperature and / or the pressure conditions in the two rooms being different, there is on the one hand a mounting problem and, on the other hand, a sealing problem.

As a rule, the sheathed or the waveguide must not be subjected to high mechanical loads in the sealing or mounting area from the outside, because this can lead to a change in the properties of the elements, especially in the case of thermocouples and measuring lines, which, after installation, can result in a costly or possibly no longer feasible recalibration.

Conventional lead-through brackets are unsuitable in terms of their structure and effect, since they cannot be combined. have, which represent a seal, a bushing as well as possibly an electrical connection.

Sheathed conductors, for example in the form of thermocouples or measuring lines, are conventionally routed inside a separate semiconductor, which can be tubular, to the corresponding measurement location in the interior of an arrangement. On the one hand, these separate waveguides are very complex to construct and, on the other hand, the sheathing of the sheathed conductors influences the measurement results, in particular the reaction time of thermocouples or measurement lines.

If a reliable working of the sheathed conductor and a largely uninfluenced measurement results of thermocouples and measurement lines, in particular a quick reaction of these elements, is required, the sheathed conductor must be led directly to the measurement site in question, without covering, usually the sheathed conductor is led through a wall from the outside area of an arrangement into the inside area and the passage due to the temperature and

Difference in pressure between the outside and the inside must be sealed.

It has been shown that conventional rubber seals cannot be used, especially in the high temperature range, since these are destroyed very quickly by the high temperatures during operation. When using metallic seals, which are applied by pressing or pressing, there is the problem that the sheathed conductor is proportionally scratched in or pushed in, which has the consequence that the measurement behavior changes as well The mechanical stability can no longer be fully or partially guaranteed and this can lead to an early defect in the device.

The object of the present invention was to find a passage holder for sheathed conductors, which works reliably at high heat and high pressures, if necessary in combination with an electrical connection, without mechanical damage and has a simple structure and handling.

This object is achieved according to the invention by a bushing with the characterizing features according to claim 1.

Further preferred embodiments of the invention result from the features of claims 2 to 9.

By using the passage holder according to the invention, on the one hand a reliable seal is created at a high temperature between the outside and inside of an arrangement and on the other hand the influence on the properties of the sheathed conductors is kept very low or there are no changes to the original properties, in particular in the case of the Use as a thermocouple or as a sheath conductor. Advantageously, the feed-through bracket is very simple in construction and manufacture and, in addition to the function as a feed-through bracket and seal already described, also allows, if required, the combination of an electrical connection to connect the sheathed conductor with a compensating line and also sheathed conductors with one another, as well as simple pre-assembly and Installation on site. The lead-through holder can advantageously be simply attached to the sheathed conductor with a handle and pushed to the desired location, where it can be connected to the sheathed conductor as an electrical connection with a sealing function or only as a seal. Depending on the field of application, different connecting means can be used here individually or in combination, such as preferably welding, soldering, gluing or single or multiple ring-shaped pressing. The latter, multiple, ring-shaped pressing, forms a labyrinth seal between the inner wall of the bushing bracket and the outer wall of the sheathed conductor.

According to the invention, the use of such a further

Bushing according to claim 10 and 11 proposed.

According to the invention, a feedthrough device for a tubular sheathed conductor or waveguide with such a feedthrough holder is also proposed. This allows tubular conductors, in particular sheathed conductors, to be passed through housing walls in the simplest way. Another advantage of this device is that the sheathed conductors can be replaced easily and very quickly when they reach their maximum operating time or in the event of a defect.

Furthermore, according to the invention, a bushing for a tubular sheathed conductor or waveguide with such a bushing holder is proposed, which is direct and can be screwed into the housing wall without an intermediate link. The advantage of this application is, in addition to the quick exchangeability of the sheathed conductor, for example after reaching the maximum operating time or after a defect, also the cost-reducing effect of the entire arrangement, since no intermediate link is required to hold the bushing. It should also be noted that fewer transitions are required as a result of this type of implementation, and thus a better seal and separation between the outer region and the inner region of an arrangement.

Exemplary embodiments of the present invention are explained in more detail below with reference to drawings. Show it:

Figure 1 shows the longitudinal section through a bushing according to the invention with inserted sheathed conductor.

2 shows the longitudinal section through a bushing device according to the invention with a bushing holder according to FIG. 1 inserted;

3 shows the longitudinal section through a bushing according to the invention with a bushing holder according to FIG. 1 inserted;

4 shows the detail of the sealing section through a bushing according to the invention according to FIG. 3 with a bushing holder according to FIG. 1 inserted;

Fig. 5 shows the longitudinal section through a bushing 1 according to the invention according to Figure 1 in a modified form, using a combination between an adhesive connection 33 and an annular pressing by pressing grooves 10, with a sheathed conductor inserted.

FIG. 1 shows the side view with partial section of a lead-through holder 1 according to the invention, which is pushed onto a sheathed conductor 3. The bushing 1 essentially consists of a cylindrical base body 5 with a ring 7. The ring 7 is arranged on an end region 2 of the bushing 1.

In the example shown, the base body 5 is in the end region

2 equipped with a cylindrical outer diameter 6 end. The sheathed conductor 3 is connected to this termination 6 with a welded or soldered connection 9. The welded or soldered connection 9 itself also serves as a seal between the outer surface of the sheathed conductor

3 and the inner wall of the base body 5. The advantage of the welded or soldered connection 9 also lies in the fact that practically no force is exerted on the sheathed conductor 3, and thus the electrical behavior or the characteristic data of the sheathed conductor are hardly or not influenced at all.

In addition to or instead of the welded or soldered connection 9, the connection between the sheathed conductor 3 and the termination 6 can also take place by means of annular, circumferential pressing, as shown by the press grooves 10. At least one, but advantageously a plurality of such press grooves 10 are preferably provided. The cylindrical inner diameter of end 6 also serves as a receptacle of the press grooves 10 and also as a reinforcement of the sheathed conductor 3 in the sealing area 15. The mechanical force on the sheathed conductor 3 can thus also be kept within a limited range. Between the inner wall of the termination 6 and the outer wall of the sheathed conductor 3, annular, circumferential connections are created by the pressing grooves 10, which connections are arranged one behind the other and act as a labyrinth seal.

The ring 7 formed on the base body 5 preferably has a circumferential annular bead 11 on its one side surface 8, which is advantageously formed in the outer region of the ring 7. This annular bead 11 serves as a mechanical sealing surface when installing the lead-through holder 1 against the lead-through opening or a corresponding device, as will be described below.

Sheathed conductors 3, which are under extreme loads and are exposed to vibrations, tend to break at the transition point 12. In order to be able to counter this problem, it has been proposed that the input 13 into the base body 5 of the lead-through holder 1 be provided with a radius 16 which prevents the sheathed conductor from being indented.

In order to enlarge the area of use of the lead-through holder 1 according to the invention, an electrical connection 14 is proposed which, as described, serves to connect sheathed conductors 3 with compensating lines 4 or sheathed conductors 3 to one another.

Advantageously, bushings 1 of this type can simply be pushed onto the sheathed conductor 3 and freely connected to the sheathed conductor 3 at the desired position. This can be useful either in the production of ready-to-install thermocouples, measuring lines or heating elements or in the assembly of thermocouples, measuring lines or heating elements directly at the installation site. The connection of the lead-through holder 1 to the sheathed conductor 3 can be carried out with easy-to-use tools, in particular when pressed on.

FIG. 2 shows a bushing device 17 proposed according to the invention for tubular conductors with a bushing holder 1 attached, in a longitudinal section. The bushing device 17 consists of a screwable main sleeve 18 and a locking sleeve 20. The main sleeve 18 is inserted at a corresponding point through a threaded hole in a housing wall 25 and sealed against the housing by known means. The main sleeve 18 and the locking sleeve 20 have a cylindrical through-channel 19 or through-opening 21, through which the tubular waveguide or the sheathed conductor 3 can be passed. The bushing 1 is now inserted and clamped over the ring 7 between the main sleeve 18 and the locking sleeve 20, the annular bead 11 of the ring 7 being a mechanical seal against a sealing surface 22 designed in accordance with the annular bead 11, as advantageously shown in FIG trained sealing surface 22 of the main sleeve 18 comes into abutment.

This device now allows simple insertion and replacement of the sheathed conductor 3 without affecting the electrical properties, since only forces are exerted on the ring 7 of the lead-through holder 1 during installation and removal. wear or be exercised and yet a reliable and in particular temperature-resistant seal is achieved.

As shown in this figure 2, the sheathed conductor 3 need not be passed through the entire bushing 1. For example, the electrical feed 23, instead of the sheathed conductor 3, can open out at the other end of the lead-through holder 1.

FIG. 3 shows a further variant in longitudinal section, which shows that the bushing 1 can be inserted directly into a housing wall 25, bypassing the bushing 17 proposed according to the invention, as described in FIG. The bore, the thread and the annular bead 11 are worked directly into the housing wall 25 and into the machine housing, respectively. The bushing 24 consists of the bore, the thread for the locking sleeve 20 and the annular bead 11. The bushing 24 and the locking sleeve 20 have a cylindrical shape

Through channel 26 or through opening 21 through which the sheathed conductor 3 or the tubular waveguide can be guided. The bushing 1 is inserted and clamped over the ring 7 between the bushing 24 and the locking sleeve 20, the

Annular bead 11 of the ring 7 as a mechanical seal against a sealing surface 22 formed corresponding to the annular bead 11, as advantageously shown in FIG. As already shown in FIG. 2, the sheathed conductor 3 does not need to be passed through the entire lead-through holder 1 in FIG. 3 either. It is true that the electrical lead 23, instead of the sheathed conductor 3, can open out at the other end of the lead-through holder 1.

FIG. 4 shows the sealing section 27, finally a preferred variant of the design of the annular bead 11 of the ring 7 of the lead-through holder 1 in a detailed longitudinal section. The sealing section 27 is designed as a double bead 30, which has the advantage in its type that it consists of the ring 7 with a formed ring bead 11, the taper support 36 and three different radii, namely the radius 28, the radius 29 and the radius 35 Of course, three identical radii, radius 28, radius 29 or radius 35, but with different centers could also be used.

If one rates the ring bead 11 of the ring 7 with the second part of the double bead 30, the radius 35, the line support of the two radii, radius 28 and radius 35, creates an anchoring pressure which allows a reaction to the action of the tightening torque of the locking sleeve 20 to generate, wherein rotation of the bushing 1 is avoided and thus it is ensured in the first phase of the compression process that the double bead 30 cannot erode, which could lead to cold sealing and would later make it difficult to loosen the seal. If you now increase the pressure on the double bead 30, the elastic ring 7 springs back and the radius 29 can seal with the radius 35 are applied, the radius 35 remaining rigid by means of the taper support 36.

This configuration as a double bead 30 results in a particularly good seal between the ring 7 and the main sleeve 18, as can be seen from the illustration in FIG. 2, or the housing wall 25, which is shown in the drawing in the said FIG. 3.

FIG. 5 shows the side view in section of a bushing holder 1 according to the invention, in a modified form, designated as a seal 31, which is pushed onto a sheathed conductor 3. The bushing 1 or the seal 31 consists essentially, as shown in Figure 1, here also of a cylindrical base body 5 with a ring 7. Der

Ring 7 is arranged on an end region 2 of the lead-through holder 1 or the seal 31. In the example shown, the base body 5 is provided in the end region 2 with a cylindrical end 6 having an outer diameter, which can preferably also be arranged in a mirror image. The sheathed conductor 3 is connected with an adhesive connection 33 to the ring 7, which already forms a unit with the termination 6 and is part of the base body 5, which consists of one piece. The adhesive connection 33 itself also already serves as a seal between the outer surface of the sheathed conductor 3 and the inner wall of the base body 5. The salient advantages of an adhesive connection 33 now lie in the fact that on the one hand the connection is very simple, since the adhesive is made by a simple stuff, advantageously a syringe, through the adhesive opening

32 can be introduced and on the other hand practically none The effect of force as well as heat occurs when the connection is made on the sheathed conductor 3, and thus the electrical behavior or the characteristic data of the sheathed conductor are hardly or not influenced at all. In addition to or instead of an adhesive connection 33, the connection between the sheathed conductor 3 and the termination 6 can also take place by means of annular, circumferential pressing, as shown by the pressing grooves 10. So described in Figure 1.

Of course, depending on the application, shapes between FIG. 1 and the described FIG. 5 are conceivable in exchange or in combination.

For the sake of good order or as an addition to FIG. 5, the most important points which have already been mentioned under FIG. 1 are listed again below.

The ring 7 formed on the base body 5 preferably has a circumferential annular bead 11 on the side surface 8, which is advantageously formed in the outer region of the ring 7. This annular bead 11 serves as a mechanical sealing surface when installing the lead-through holder 1 or the seal 31 against the lead-through opening or a corresponding device, as will be described below.

In order to prevent the sheathed conductor 3 from breaking at the transition points 12, caused by extreme vibrations, and to be able to counter the expected damage, it was proposed that the entrance 13 and also the exit 34 into the base body 5 of the lead-through holder 1 or as the seal 31 is to be provided with a radius 16, which prevents notching of the sheathed conductor or the waveguide.

Advantageously, such lead-through holder 1 or seals 31 can simply be pushed onto the sheathed conductor 3 or waveguide and freely connected to the sheathed conductor 3 or waveguide at the desired position. This can be useful either in the production or in the assembly of ready-to-install thermocouples, measuring lines or heating elements directly or at the installation site. The connection of the lead-through holder 1 or the seal 31 to the sheathed conductor 3 can be carried out with easy-to-use tools, in particular when pressed on or glued.

In contrast to conventional rubber seals, the bushing holder 1 proposed according to the invention achieves a substantially higher temperature resistance, which is only made possible by the bushing 1 proposed according to the invention, such sheathed conductors 3 or

Introduce waveguides into rooms to be measured without additional cladding and thus achieve very fast response times. In contrast to known mechanical crimp seals, which act directly on the sheathed conductor 3 or waveguide, and thus influence the changes in the electrical properties already mentioned, which always requires a costly recalibration, the proposed grommet 1 or seal 31 can also be used to replace the sheathed conductor 3, as an application of thermocouples, measuring lines and heating elements, very quickly and without influencing the electrical properties.

Claims

claims

1. Feed-through bracket (1) for tubular sheathed conductors

(3), in particular for the production of thermocouples, measuring lines and heating elements, characterized in that their body consists of a tubular base body (5) which has a concentrically arranged ring (7) on the outside and whose inner cross section is approximately the same as the outer cross section of the tubular sheathed conductor (3) corresponds.

2. Feed-through holder 1 according to claim 1, characterized in that the ring (7) is formed on an end region (2) of the base body (5), at least part of the base body (3) being removed on both sides of the ring (7). protrudes.

3. bushing bracket 1 according to claim 1 or 2, characterized in that the base body (5) has an end (6) at one end.

4. bushing bracket 1 according to one of claims 1 to 3, characterized in that the ring (7) on a side surface (8) has a concentrically formed annular bead (11) on its outer edge region.

5. bushing 1 according to claim 4, characterized in that the annular bead (11) is designed as a double bead (30).

6. bushing 1 according to one of claims 1 to 5, characterized in that the base body (5) and the ring (7) consist of metal.

7. bushing bracket 1 according to one of claims 1 to 6, characterized in that the base body (5) and the ring (7) consist of one piece.

8. bushing 1 according to one of claims 1 to 7, characterized in that the basic body (5) is equipped with an electrical connection (14).

9. bushing 1 according to one of claims 1 to 8, characterized in that the base body (5) with the sheathed conductor (3) by a welded or soldered connection (9) or by an adhesive connection (33) or by single or multiple, annular Compression is connected.

10. Use of a lead-through holder 1 according to one of claims 1 to 9 for the positioning of a tubular jacket conductor (3), in particular of thermocouples, measuring lines and heating elements, in an opening by the bushing holder (1) being pushed onto the tubular jacket conductor (3) and is connected to this by means of a soldered, adhesive or welded connection (9) on at least one termination (6).

11. Use of a lead-through holder 1 according to one of claims 1 to 9 for the positioning of a tubular jacket conductor (3), in particular of thermocouples, measuring lines and heating elements, in an opening by the bushing holder (1) being pushed onto the tubular jacket conductor (3) and is connected to the latter by means of circumferential pressing on at least one, preferably on a plurality of adjacent pressing grooves (10).

12. Feedthrough device 17 for tubular sheathed conductors

(3), in particular of thermocouples, measuring lines and heating elements, with a lead-through holder (1) according to one of claims 1 to 9, characterized in that it is a two-part screw sleeve with a main sleeve (18) and a locking sleeve (20), each with a centrally arranged through-channel ( 19) or the through opening (21), the through channel (19) or the through opening (21) of the base body (5) merging into an internal thread on one side of the main sleeve (18) via a sealing surface (22), into which the locking sleeve

(20) can be screwed in, which is designed such that it can be brought into abutment on one side against a side surface (8) of the ring (7) of the lead-through holder (1), the opposite side surface (8) of the ring (7) with the Sealing surface (22) comes into contact.

13. bushing 24 for tubular sheathed conductor 3, in particular a thermocouple, with a bushing holder (1) according to one of claims 1 to 7, characterized in that the bushing (24), each with a centrally arranged through channel (26) or the through opening (21) The passage (26) or the passage opening (21) of the base body (5) merges into an internal thread on one side of the bushing (24) via a sealing surface (22), into which a locking sleeve (20) can be screwed which is designed such that it can be brought into abutment on one side against a side surface (8) of the ring (7) of the lead-through holder (1), the opposite side surface (8) of the ring (7) with the sealing surface (22 ) comes into play.