JPH058344B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Application] The present invention is a frame member for a flange with low leakage loss for overpressure and low pressure air passages, which has a hollow shape made of metal and is suitable for use in air passageways. namely, the insertion gap at the end of the duct wall (this gap is formed by the outer and inner webs in the area covered by these webs), the supporting web adjoining the outer web at an obtuse angle; and two parallel air-tight recesses in the inner web (the first recess, which is further outward of the recesses, is remote from the insertion gap and extends parallel to the frame member).
The present invention relates to a frame member comprising:

[Background of the invention]

Such a frame member is formed from a coil material (steel plate) using a forming machine. The metal plate used is that designated ST 02 Z DIN 17162. This metal plate is galvanized on both sides. The main problem with such flanges is whether they are sufficiently gas-tight against the overpressure that often prevails inside them. However, the flange must also be suitable in the case of negative pressure, which rarely occurs. These flanges should also be suitable in structure for low-pressure, medium-pressure and high-pressure air ducts as far as possible. The fact that the same structure can be adopted for various pressures is worthy of study. This is because in this way it is possible to maintain the same product family regardless of the pressure and, for example, no special frame elements are required in most cases, or at least in extreme cases. In this case, the frame member is sufficiently tight even when the highest pressures occur, but it is constructed in such a way that this tightness requires measures that require additional costs, complications and changes in the product range. Must not be. Although this will result in justifiable expenditures for high voltages, it will mean overspending in the medium and low voltage areas, and this will have a knock-on effect on the price. Furthermore, the frame member must comply with the standard as much as possible so that new standards are not required, and it is better if changes to the standard are not noticeable. Such standards are for example
1982 Heating and Ventilation Contractors Association “Specification for sheet metal ductwork” D.
It is W.142. For example, on page 13, there is a low-pressure wind duct,
It describes what medium-pressure air ducts and high-pressure air ducts are, where the leakage limit is, and what calculation principles are applied. A flange to which the present invention can be applied is shown in FIGS. 40 and 42 thereof. However, the invention can also be applied to purely L-shaped frame parts without support webs.

For example, as can be seen from FIG. 42 above, high pressure can be achieved by means of a high pressure flange and by using a thick plate with a thickness of 0.8 mm to 1.25 mm. To save costs, 0.7mm thick plates are still used.

Of course, the frame member must also fulfill its major task, namely interconnecting two frame members. This means that the frame member must be mechanically very rigid. This is because the load on that part becomes extremely large. Many companies drive work vehicles through wind roads when inspecting them. It is also perfectly normal for repair team members to walk or pass through the wind channel. Furthermore, the burden arises that not only the static pressure has to be maintained. On the contrary, there is a column of air within the wind tract with vibrations ranging in frequency from sub-high to supersonic. The amplitude spectrum of this frequency is also extremely diverse.

For example, in order to improve airtightness,
A pocket portion as shown in FIG. 1 may be provided. The manufacture of this pocket, into which the end of the wind wall enters, makes the manufacture of frame members expensive in an area where there is extremely intense price competition for 1/10th Penitzsch. Secondly, such a pocket part can rotate the material once in 180° and once in 90°
It can only be produced by bending it twice. This is an overload for the plate, and basic research shows that this bending process deviates too far from the neutral region, crushing the material in the compression zone and tearing the material in the tension zone. This can be demonstrated very easily by dipping the flange thus bent into a salt solution. After a few days, rust spots can be seen in the overloaded area.

In this bending operation, the zinc layer, which is itself ductile, can crack and become crushed by the rolls subjected to strong repetitive bending action.

In any case, when an ever-thinner sheet of metal is subjected to such damage, the weakest point naturally determines the overall quality, just as the weakest link in a chain determines the overall quality. Expenses invested in other aspects are lost.

The introduction of claim 1 of the present application is based on German Patent No. 3207990.
There, the inner web is provided with two grooves which act as a gastight seal. In this case, however, a tightness is not achieved by means of grooves in the sense of the invention. On the contrary, it is desired that the grooves serve to strengthen the inner web, thereby avoiding warping of the sheet metal material caused by the heat of spot welding. However, this leads to a completely different problem. Furthermore, inwardly profiled grooves are advantageous against leakage losses. This groove can be seen as a connecting airway running over the entire length of the frame member, which connects all air leakage channels at this level to one another in a nodal manner. Therefore, from a static perspective, a groove connects a leakage path that comes from one side but does not completely penetrate there with a leakage path that comes from the other side but does not originally penetrate there, creating a communication system. is formed.

In known flanges, the airtightness intended by the present invention is achieved by the pocket portion, but
This pocket part must have its legs bent very precisely so that the edge of the end of the wall of the inserted airway lies above the pocket part like a knife-pack.

[Summary of the invention]

The object of the present invention is to provide a means for substantially reducing leakage losses without using such a pocket part, in a simple manner for conventional flanges, without weakening the flanges, and without significantly increasing the cost. The goal is to provide the following.

According to the present invention, the above-mentioned problem is solved by the features understood from the feature part of claim 1 of the present application. The tolerances that are customary in this area of sheet metal processing must not be increased during manufacturing.

According to the feature of claim 2, the airtight surface formed by the end face is not enlarged.

According to the feature of claim 3, at the inserted end of the air duct wall, the webs are separated from each other by a certain amount, ie equal to the thickness of the plate of the air duct wall.

According to the features of claim 4, the other areas of the web can also be made to be separated from each other by essentially the same amount when the end of the air channel wall is inserted. .

According to the characteristic matter of claim 5, the second
Minimal forming operations are required during the production of the web and the steel joints are not destroyed.

According to the features of claim 6, this region which is subjected to high loads is provided with a better quality of material, and the material is not deformed in such a way that the seam is destroyed.

According to the feature set forth in claim 7, the airtightness can be improved as is clear from the embodiments of the present invention.

The same can be said about the feature of claim 8.

According to the feature of claim 9, the second
The large area of the recess serves as an airtight surface.

According to the features of claim 10, the surface is reduced towards knife-packing without the disadvantages of knife-packing.

According to the features of patent claim 11, the second recess has very good resistance due to the channel being an area of special strength.

According to the feature of claim 12, the tension generated by the connection (usually the welding point) can be applied equally to both the front and the top.

〔Example〕

The invention will be explained in detail by means of preferred embodiments shown in the drawings.

The frame part 11 has an insertion cavity 12 for an angled arm 13, which is not shown in detail. In particular, this frame element has an outer web 14 extending in the longitudinal direction of the air channel, an inner web 16 extending in the longitudinal direction of the air channel and a support web 18 that transitions at an obtuse angle with the fold 17, which support web It is approximately 45° to the horizontal in the drawing. The outer web 14 extends straight,
It has a short gripping projection 19 at its free end. To that extent, this outer web has the form of a frame element, such as that already sold for many years by Georg Metz G.M.B. under the product number 117. The other dimensions also correspond to the known state of the art.

A horizontal dashed line 21 indicates the position of the folded portion 17.

The inner web 16 is typically 4.5 mm wide at its free end.
It has a first annular recess 22 . Its cross section is approximately circular. This recess 22 is located in the inner web 16.
It has a free end surface 23 which is 0.5 mm higher than the inner surface 24 of the tube. Starting from the dash-dotted line 21, i.e. close to the fold 17, a second recess 26 is provided, which projects towards the insertion gap 27 and has a total length of about 2.5 mm and is arcuate with a gentle transition radius. It's summery. In the embodiment, the recess has a length
2.5 mm, and is 0.5 mm higher than the inner surface 24. Its top 28 is in contact with the inner surface 29 of the outer web 14. The free end face 23 is therefore the top 28
Similarly, it is located higher than the inner surface 24.

Arrow 31 indicates the position of the subsequent bond. This may be a spot weld in the case of a steel air duct or a riveted weld in the case of an aluminum air duct. The invention is clearly also suitable for aluminum frame parts and aluminum air ducts.

The recess 22 may be empty and may be provided with a durable plastic packing therein, the upper surface of which is free end surface 23.
It is located higher than.

In the embodiment of FIG. 2, the second recess 32 is
Compared to 6, it has a much stronger V-shape.
In this case, rolling is carried out in such a way that a high pressure is generated in the central part 33 by the rolls facing each other, so that the material is compressed in the central part 33. However, the top of the recess 32 is not sharp, but is likewise rounded.

FIG. 3 shows the device in a spot welded state.
In the present invention, conventional regular welding point spacing can be used as is. Therefore, there is no need to increase the number of welding points. As can be seen in FIG. 3, the free end surface 23 is in contact with the inner surface 34 of the wall 36 of the air channel. Furthermore, the top 28 is in contact with the inner surface 34. The outer web 14 lies essentially parallel to the outer surface 37 of the airway wall 36. An intermediate portion 39 between the first and second recesses 22 and 26 is located at the welding point 3.
8 towards the inner surface 34. The intermediate part 39 is therefore tolerably curved, and the free end face 23 and the top part 28 are pressed against the inner surface 34 by the sealing force.

If an excessive amount of durable plastic packing is applied to the recess 22, a portion of the excess will be present in the wedge-shaped gap 41. This is because the recess 26 (or 3
This is because the left flange side of 2) comes off and the internal pressure within the wall 36 of the airway pushes the durable plastic packing further into the wedge-shaped gap 41. The folds 17 help the outer web 14 hold up against the pressure of the top 28.

The metal plate of the airway is usually 0.7mm thick.

The present invention provides commercially available flanges 117, 120 and 120 at pressures of 500 to 2500 Pascals.
It is effective compared to S. That is, essentially the height of the recess 26 is the problem. Therefore, when the pressure is 500 Pascal, a height of 0.5 mm is optimal. This is a 60% improvement, which is both dramatic and unexpected in this field despite the narrow tolerances. Furthermore, in the case of 500 Pascal, an improvement of 34% can be considered with a height of the airtight recess of 0.3 mm or 0.7 mm, which is well beyond the range that can be expected by those skilled in the art.

Even at a pressure of 2500 Pa, it can be considered quite remarkable that an improvement of 47% can still be obtained with a hermetic recess height of 0.5 mm; It has been shown that it has an excellent effect.

This improvement is even greater for flange 120. The flange 117 has a metal plate thickness of 0.7 mm, but the metal plate thickness of the flange 120 is
It is 0.8mm.

The flange 120 is a flange with a pocket portion, but according to the present invention, values almost close to those obtained with the flange 120 can be obtained even without the pocket portion.

Leakage loss measurements of a Type 117 flange with recess 26 were made without thermoplastic material.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a frame member according to the invention, also showing the inserted angle arm cross-section. 2 is a cross-sectional view of a different embodiment of the second recess, and FIG. 3 is a cross-sectional view of the embodiment of FIG. 1 with inserted airway wall ends and spot welding points. 11... Frame member, 12... Insertion space, 1
3... Arm, 14... Outer web, 16... Inner web, 17... Bent portion, 18... Support web, 19... Grasping protrusion, 22... First annular recess, 23... End face, 26...second recess, 27...
...Insertion gap, 28...top.

Claims (1)

[Scope of Claims] 1. A frame member for a flange with low leakage loss for overpressure and low-pressure airways, which has a hollow metal shape and has an insertion gap at the end of the wall of the airway. (this gap is formed by the outer web and the inner web in the area covered by these webs), the support web which continues to the outer web at an obtuse angle, and the parallel support web which acts as an airtight seal on the inner web. with two recesses (the first recess being more external to the recesses and extending parallel to the frame member away from the insertion gap), a the first recess is free of the inner web; b The outer end surface of the first recess reaches a part of the thickness of the metal plate of the frame member than the inner surface of the inner web, but is at least 1/1 of the thickness of the metal plate. 3
c The inner web is located higher than the second inner web formed in the insertion gap.
a recess slightly forward of the transition from the outer web to the support web, having an arcuate cross section and a height corresponding to approximately 1/4 to the entire thickness of the metal plate; d the outer web connects the inserted metal plate of the wall of the airway and the inner web in the range between the front surface and the second recess. 2. The frame member according to claim 1, wherein the end surface of the first recess is parallel to the inner surface of the first web. 3. The frame member according to claim 1, wherein the top of the second recess is in contact with the inner surface of the outer web without the metal plate inserted therein. 4. The frame member according to claim 1, wherein the inner web and the outer web extend substantially parallel to each other when no metal plate is inserted. 5. The frame member according to claim 1, wherein the arcuate cross section of the second recess has a gentle transition radius. 6. A frame member according to claim 1, wherein the material of the second recess is significantly compressed in the arc. 7. The frame member according to claim 1, wherein the height of the second recess is 0.7 (-60% + 140%) of the thickness of the metal plate of the frame member. 8. The frame member according to claim 1, wherein the height of the second recess is 0.7 (-20% + 80%) of the thickness of the metal plate of the frame member. 9. The frame member according to claim 1, wherein the second recess is approximately semicircular. 10. The frame member according to claim 1, wherein the second recess has a flat V-shaped cross section. 11. A frame member according to claim 1, wherein the second recess begins where the support web transitions into the outer web. 12. Frame element according to claim 1, wherein the area for connection is within half the distance between the front surface and the top of the second recess.