JPS59500756A - How to make truss core sanderch panels - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] How to make a truss core sandwich fist panel This invention is a truss core sandwich fist panel manufacturing method. For more information on how to make Deutch panels, please see our truss-shaped core. Economically possible fabrication of stabilized lightweight, high-strength structural sandwich panel materials Regarding the method.

2. Description of prior art Solid-metal plates made from steel or aluminum are common constructions. It is a construction member. Plate material has the advantage of being extremely strong, but it is also extremely heavy. It has disadvantages.

At the other end of the range are honeycomb core type structural panels. honeycomb core The panel states that it can achieve significant buckling strength at significantly reduced weight. In this respect, it is much more efficient than plate material. On the other hand, honeycomb core One of the problems with flannel is that it is limited to relatively thin face sheets and is difficult to manufacture. The point is that the manufacturing cost is extremely high.

Intermediate between the extremes of the flat material and honeycomb core panel is a corrugated sheet or sheet. Typically manufactured using two face sheets stabilized by a lath core. There is something called a Las Core Sandwich Panel.

Such truss-core sandwich fist panels are similar to conventional honeycomb core panels. Although it is not as efficient in buckling mode as compared to It is much more efficient than plate material and is also much lighter than plate material. , a significantly larger gauge face sheet than possible in a honeycomb-worked core panel. It can be made with.

The difficulties traditionally encountered in truss core sandwich panels are secondary to Attaching the face sheet is a difficult and expensive manufacturing process. vinegar That is, once the first face sheet is connected to one side of the corrugated sheet, this corrugated This side of the sheet can be contacted to connect the other side of it to a second facing sheet. It is no longer possible. As a result, the second face sheet can appear in a variety of different states. It has been fixed to corrugated sheets in various ways.

For example, this type of truss core fist sandwich panel uses rivets. It is commonly used for structural parts of airplanes. The first face sheet is driven The second face sheet is attached to the corrugated sheet by rivets, and the second face sheet is generally Attached to the core using hole rivets. Rivets are heavy gauge material Although the manufacturing process is generally good, the manufacturing process is time consuming and typically In machine type applications, the head of the rivet is aligned with the outer surface of the panel. This is because it is necessary to use a chamfer milling cutter to make the edges. For thin-walled panels rivets are completely unacceptable.

Brazing and adhesive connection techniques can be used for finished parts, but are not attached to the structure later. It cannot be applied to panel materials that are lifted up. i.e. brazing or bonding In the process, a low melting point alloy or glue is placed between the corrugated sheet and the second face sheet. is used and the entire panel is raised to cause curing of the connecting material. exposed to high temperatures. However, if the panels formed in this way are later If the components are machined and welded, this welding will Alternatively, brazing may deteriorate the material, which may cause contamination of the weld itself. I will probably do it.

Laser welding and electron beam welding connect the second face sheet to the corrugated sheet This is a possible technology. However, since welds are typically extremely narrow, , at least two passages must be created to create a structural connection. do not have. Additionally, equipment for electron beam and laser welding is extremely expensive and unavailable. It takes much longer than traditional resistance welding techniques.

Because of the above-mentioned difficulties, the face sheet is stabilized by a truss core and is resistant to melting. Truss-core supports are used to fabricate detailed structural components where connections are made by contact. switch panels are used almost exclusively. These components are relatively (short in the wave direction) and the second surface sheet is mechanically expandable. Resistance welded to the truss working core using a mandrel. In other words, a mandrel consisting of multiple parts is located between the first face sheet and the corrugated sheet in its collapsed state. In this case, the corrugated sheet is made to contact the second face sheet. It will be done. The mandrel is then adapted to fill the gap between the first face sheet and the corrugated sheet. mechanically expanded to the height of the corrugated core. The first and second face sheets face each other The expandable mandrel is positioned between the welding electrodes that It forms the same plane as the pole. A second surface sheet is formed by passing current between the first and second electrodes. The sheet can then be welded to the corrugated sheet. The mandrel is then mechanically deformed, These steps are repeated.

Although the process described above is useful in itself, expandable mandrels are expensive to manufacture and labor intensive. The process is too slow and the finished product is too expensive. slow expensive Although this process is suitable for detailed structural components, it is not suitable for producing finished components. A family of truss core sandwiches that can be used as structural panel construction materials ・Probably unsuitable for panel production.

A family of truss core sandwich mediums for use as structural panel construction materials. In making flannel, panels can be made to any significant length, e.g. up to 12 feet. It is desirable to manufacture it. If welding is a connecting process, use a mandrel to extending between the truss core and the first face sheet connected thereto. is necessary. Obviously, this could be done using an expandable mandrel. However, it comes with the problems mentioned above.

If a solid mandrel is used, it should be at least as long as the panel and 12 It would have to exceed feet. First of all, this length of copper It would be extremely expensive to manufacture the mandrel, and the mandrel would be very heavy. Dew. Any slight deformation of the panel due to welding distortion will cause the panel to curve. It would be virtually impossible to remove the mandrel.

Another possibility is to drill slots 2.3 inches apart in the mandrel to provide bending flexibility. It will give you sex. This method works well for only 2.3 rows of welds. However, after continuous use, the edge of the slot may break due to the pressure of the electrode ring. This causes the problem of localized welding. Continue to use it by bending it again. If used, the mandrel would break at the slot.

Another possible technique for imparting bending flexibility to the mandrel is to increase the height of the mandrel. For example, you could reduce it by 050" and add a 050" piece of copper to the back of the mandrel. cormorant. In this case, since the copper piece is flexible, it is difficult to pull it out after welding. is created, and the panel is distorted due to the added gap of the core 41. Removal of the mandrel will be easier even in the case of For large panels If we consider an automated welding machine with multiple electrodes and However, an excessive amount of copper mandrel material for electrodes is required per panel. Dew.

Summary of the invention According to this invention, these problems are stabilized by a truss-shaped core. An economically viable option for producing lightweight, high-strength structural sand inch panel materials solved by providing a method. According to the manufacturing method of this invention, structural Thickness and cost of various face sheets/core Φ sheets used as panel construction materials Enables the formation of a series of truss core sandwich panels with a height of . Resistance welding is the connection method, and conventional resistance welding equipment can be used. mechanical This eliminates the need for expandable mandrels and long, expensive and heavy copper mandrels. .

Instead of utilizing an expandable mandrel, this invention uses a simple miniature mandrel to reduce the required electrical power. Facesheet material produced by applied electrode force to achieve gas contact The allowable elastic deformation of Since all materials have elasticity, the force The addition of a force causes a deflection of the material, and when this force is removed, the yield point of the material is not exceeded. the material returns to its original static position. Those who utilize this principle and relate to this invention The method calculates the exact formation of the corrugated core as well as the allowed elastic deflection of the face sheet. It is intended that Only the mandrel that allows this amount of deflection is selected. resistance During welding, the face sheet is flexed and brought into contact with the mandrel to ensure electrical continuity. Sufficient electrode pressure is applied to After resistance welding and the electrode force is removed After that, the face sheet elastically returns to its static position and the mandrel moves to another position. It can be moved to

Briefly, it includes first and second face sheets affixed to opposite sides of a corrugated sheet. The method of the present invention for producing a truss core sandwich panel of the type Weld the face sheet to one side of the corrugated sheet, and weld the second face sheet to the other side of the corrugated sheet. this first side between the first face sheet and the corrugated sheet, positioned in contact with each other; Position the conductive mandrel at the point of greatest spacing between the sheet and the corrugated sheet. At this time, the height of the mandrel is greater than the distance between the first face sheet and the corrugated sheet. The first and second welding electrodes are made smaller by a predetermined amount, and the first and second welding electrodes are made smaller by a predetermined amount. 2 face sheets are positioned, the mandrel is flush with each electrode, and these electrodes applying a welding force to the first and second face sheets, and the force causes the first face sheet to become elastic. Both sides of the mandrel are brought into contact with the first face sheet and the corrugated sheet to form a gap between each electrode. The predetermined amount is sufficient to enable electrical continuity. The deflection of the first face sheet is such that it does not exceed the yield point of the first face sheet, and the method described above is further applied. resistance welds the second face sheet to the corrugated sheet by passing current between the first and second electrodes. , and a step of releasing the welding force. Here, the mandrel is the first face sheet and the corrugated sheet can be moved to another new position, and the welding process can be repeated. Therefore, one object of this invention is to Various problems traditionally encountered when using resistance welding to fabricate Chiken panels The goal is to solve the problem. One feature of this invention is that one corrugated sheet and one surface The material can be moved between the sheet and the material during welding. This can be achieved by using a small conductive mandrel that does not exceed the yield point. The aim is to solve these problems. One advantage gained is that the truss core sun It is an economically viable method for the production of German panels. Yet another advantage is a group of truss cores that can be used as structural/inel construction materials. - Making sandwich panels. Another advantage is that it can be expanded mechanically. This eliminates the need for a mandrel. Another advantage is brazing and gluing technology This eliminates the difficulties encountered when using . Another advantage is that expensive rivet This eliminates the need for hammering, laser welding, and electron beam welding techniques. Different The advantage is that bulky and expensive copper mandrels are no longer required.

Further aspects, features and attendant advantages of the invention may be found in accordance with the preferred embodiments. The following detailed description of these embodiments may be read with reference to the accompanying drawings. will be clear to those skilled in the art. Identical in some of those drawings Same symbols indicate the same parts.

Brief description of the drawing FIG. 1 includes first and second facing sheets affixed to opposite sides of one corrugated sheet. FIG. 2 is a partial perspective view of a truss core punch panel: FIG. 2 is a perspective view showing how the first face sheet is resistance welded to one side of the corrugated sheet. is; FIG. 3 illustrates the method of the present invention for resistance welding a second facing sheet to a corrugated sheet. Figure 4 is a perspective view of one short mandrel usable in the method of the invention; be: FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. 3 prior to application of welding force; FIG. 6 shows the elastic deflection of the first face sheet upon application of welding force; FIG. An enlarged sectional view taken along line 5-5 of As shown in the figure, a first corrugated sheet or truss core 16 is attached to both sides of the corrugated sheet. and a second face sheet 11 and 12, generally designated 10. A small section of a truss core sand inch panel is shown.

The purpose of this invention is to provide a The purpose is to manufacture a group of panels 10 of large sheets, such as '. panel It is structurally efficient, lightweight and suitable for use in a wide variety of structural components. I'm sure you're doing it. Also, the panel 10 can be assembled in an economically possible manner using resistance welding. It is also an object of this invention to manufacture.

Referring now to FIG. 2, connecting the corrugated sheet 13 to the face sheet 11 is simple. and proceed in an efficient manner. That is, one side of the corrugated sheet 16 is the face sheet 1. The face sheet 11 and the corrugated sheet 13 are positioned in contact with the 1 side of 1, and the face sheet 11 and the corrugated sheet 13 are electrode wheels 14 and 15 rotatably mounted on shafts 16 and 17, respectively; It is positioned between the opposing welding electrodes shown as . Multiple electric charges Poles 14 and 15 are typically located on one common axis and have multiple waveforms. The wrinkle knots can be welded to the facing sheet 11 at the same time. In any case, the sheet 11 and 13 move in the direction of the waveform wrinkles with respect to the electrode wheels 14 and 15 to form a waveform. The joints of sheet 13 are welded to face sheet 11.

According to the invention, and now referring to FIGS. 3-6, face sheet 1 2 on the other side of the corrugated sheet 13 and between the tote 11 and the corrugated sheet 16, and When the corrugated sheet 16 comes into contact with the face sheet 12, the face sheet 12 becomes a corrugated sheet. It is fixed to the other side of the port 13. As seen from Figures 5 and 6 , the top surface of the mandrel 20 generally conforms to the shape of the corrugated sheet 16, while the bottom surface of the mandrel 20 The surface is generally flat. rotatably attached to shafts 23 and 24, respectively. The panel 10 is positioned between a pair of rotatable electrode wheels 21 and 22. between electrodes 21 and 22 so that sheet 13 can be welded to sheet 12. Electrical continuity can be achieved via the sheet 11 and the mandrel 20.

According to the invention, and as shown most clearly in FIGS. , the height of the mandrel 20 is determined by the thickness of the corrugated sheet 16 from the distance between the face sheets 11 and 12. Since the mandrel 20 is smaller than the thickness minus the thickness, the mandrel 20 is Can be moved freely. Therefore, as shown in FIG. In its resting state, it is spaced apart from the corrugated sheet 13. the The interval is a predetermined amount. This predetermined amount forces electrodes 21 and 22 towards each other. When the welding force is applied to the sheets 11 and 12 by directing the The sheet 11 is elastically bent to bring the mandrel 20 into contact with the sheet 13, completing the electrical circuit. It is calculated so that The height of the mandrel 20 is determined by the yield of this deflection of the face sheet 11. selected so as not to exceed the point.

In further detail, an applied force causes a deflection, but the material exceeds its yield point. meaning that the material returns to its original static position as long as the applied force is removed In , all materials are elastic. This principle is based on the allowable elasticity of the face sheet. Calculate the sexual deflection and adjust the height of the mandrel 20 so as not to exceed this deflection. This is used in this invention. Using such a suitable mandrel, the welding force is applied to sheets 11 and 12 via electrodes 21 and 22, respectively, to An electric circuit is completed between the electrodes 21 and 22 via the electrode 120, and the electrode Electricity is applied between 21 and 22 to complete the welding process.

After the welding process is completed, the welding force may be released, and the face sheet 11 will accordingly It returns elastically to the rest position, allowing movement of the mandrel 20.

Calculation of the appropriate height of mandrel 20 is accomplished using the well-known static beam loading equation. vinegar That is, the radius of curvature R of the bent sheet 11 in the elastic range is expressed by the equation obtained from. here Elastic modulus of the material of the E-plane sheet 11:! Whale moment of inertia: M≠bending moment. .

Bending stress σ is equal to It is also related to the bending moment and the moment of inertia. here t: Thickness of the face sheet 11.

Solving equation (2) for M gives us And if we substitute this expression for M in equation (1), equation (1) becomes It is agreed to.

From simple geometric calculations, the distance y (see Figures 5 and 6), i.e. the axis 2 The difference between the height of 0 and the interval of face sheet 11 and waveform sheet) IAISli is equal. It can also be shown that the equation is related to the radius and radius of curvature. Here P is a wave The length of the unsupported portion of the face sheet 11 between the connection points of the face sheet 11 to the shaped sheet 16 It's equal to that.

Are the quantities in equations (4) and (5) both known or calculable? Therefore, calculating y is a simple matter. For example, 316L stainless steel On the other hand, when t = 060'', σfll force (yield strength of alloy) = 30. 000 psi and E=28×10 pmi. Equate these numbers with equation (4) By substituting into By substituting the value of into Equation (5), it is possible to derive the center-to-center distance of 11iliF=,018'/ becomes.

According to this invention, the radius of curvature of the outer surface of the electrode 21 is different from that of the electrode 21 and the face sheet 11. is chosen to be equal to this calculated value of R to give surface contact between Ru.

By configuring the mandrel 20 according to the teachings of this invention, the mandrel 20 is free of electrode pressure. It becomes possible to freely slide between the side surface sheet 11 and the corrugated sheet 13, and the above-mentioned type Many problems will disappear. Therefore, whether it is a long mandrel or a slotted mandrel, It can also be used with a two-piece mandrel. However, preferred embodiments of this invention According to the example, the pulling operation of the mandrel and the production of a long, heavy and expensive mandrel are shown in Figure 3. and is eliminated by using one short moving mandrel as shown in Figure 4. . That is, a short mandrel approximately 2 inches long is connected to a pair of mandrel pull rods 26 and 27 may be connected. In practice, the bales 26 and 27 cool the mandrel 20. a continuous length extending within the mandrel 20 through which water is directed for the purpose of The piping may have a When the mandrel 20 is positioned as shown in FIG. The welding force can be applied as shown above, and the welding work is completed. Then release the welding force This makes it possible to elastically return the face sheet 11 to its static position. , a spacing is provided between the mandrel 20 and the corrugated sheet 16. Sheets 11 to 16 are It is then moved to another position with respect to the mandrel 20 and the electrodes 21 and 22. is completed, the welding force is reapplied, and the welding process is repeated. Panel 10 is an electrode A movement in which electrode force is periodically applied and released when moving between 21 and 22. This running rod process allows resistance welding to be carried out quickly and economically. becomes possible.

Therefore, according to the present invention, a lightweight, high-strength device stabilized by a truss-shaped core Various problems conventionally encountered in producing structural sand inch panel materials is solved in an economically viable manner. The manufacturing method of this invention can be used as a construction material. A group of truss core sandy with various wall thicknesses of face sheets/core sheets for This enables the production of touch panels. Resistance welding is the connection process and traditional Resistance welding equipment may be used. Mechanically expandable mandrels and long, expensive and heavy The ugly copper mandrel becomes useless.

Having described this invention in terms of preferred embodiments constructed in accordance with the invention, Various changes and improvements can be made without departing from the scope and spirit of this invention. will be obvious to those skilled in the art. Accordingly, this invention is embodied by certain illustrative embodiments. Without limitation, the claims are limited only by the scope of the appended claims.

Claims (1)

[Claims] 1. The first and second (b) above-mentioned second surface sheets fixed on both sides of one corrugated sheet. positioning the sheet in contact with the other side of the corrugated sheet i; (c) One conductive mandrel is positioned between the first face sheet and the corrugated sheet. said stage, which is smaller than the separation of said mandrels by a predetermined amount; 2) Apply a force to the first and second face sheets, and apply a force to the first face sheet. is bent so that both sides of the mandrel come into contact with the first face sheet and the corrugated sheet. Also, the predetermined amount is such that the deflection of the first face sheet is 'of this first face sheet. applying said force that does not exceed the yield point; (e) Welding the second face sheet to the corrugated sheet; (f) The manufacturing method described above, including the step of releasing the welding force. further comprising a step of repeating the steps of (force above), (e) and (e); Truss core sandwich according to claim 1 How to make panel 013. 4. The position of the mandrel is in the front direction for welding the second face sheet to the corrugated sheet. from one side of the panel to the other, and the force is applied and released periodically. A method of manufacturing a truss core sandwich panel according to claim 3. 5. the force is applied to the first and second face sheets by a welding electrode; Truss core sun according to claim 1, 2, 3 or 4 Deutsch panel rod manufacturing method. 6. Format including first and second face sheets fixed to both sides of one corrugated sheet A method for producing a trussed sandwich panel, comprising: (→ Welding the first face sheet to one side of the corrugated sheet; (b) A stage for positioning the second face sheet in contact with the other side of the corrugated sheet. Floor and: (c) One conductive mandrel is positioned between the first face sheet and the corrugated sheet. The height of this mandrel is determined by the distance between the first and second surface seams 6. minus the wall thickness of the above corrugated sheet, which is smaller by a predetermined amount. The following steps: b) Position the first and second face sheets between opposing welding electrodes, and also making the mandrel coplanar with the electrode; (e) Applying welding force to the first and second face sheets using the electrodes, The force elastically deflects the first face sheet into contact with the mandrel, and This mandrel is brought into contact with the corrugated sheet to create electrical continuity between the electrodes. The step of applying electricity: (f) energizing between the first and second electrodes. (g) welding the second face sheet to the corrugated sheet; (g) the welding force; a step of releasing the The above manufacturing method, including 7. (a) Relative position of the mandrel and the first face sheet and the corrugated sheet Steps of changing the position; (S) Repeating steps (E), (F) and (G) above. A truss core sandwich according to claim 6 further comprising the step of: How to make a switch panel. 8. The length of the mandrel is significantly smaller than the length of the panel in the direction of the corrugation. According to claim 7, the Udras core sandwich panel is Production method. 9. relative position of said mandrel for welding said second face sheet to said corrugated sheet; is changed from one side of the panel to the other, periodically applying and releasing the welding force. Fabrication of a truss core sandinch panel according to claim 8 Method. 10. Shape including first and second face sheets fixed to both sides of one corrugated sheet 1. A method for manufacturing a truss core sandwich panel of (a) welding the first face sheet to one side of the corrugated sheet; (b) Step of positioning the second face sheet in contact with the other side of the corrugated sheet. and; (c) Calculate the allowable elastic deflection of this sheet that does not exceed the yield point of the first face sheet. Steps to calculate: ) one conductive mandrel is positioned between the first face sheet and the corrugated sheet; Moreover, the height of this mandrel is the distance between the first surface sheet and the corrugated sheet. of the above position, which is less than the above calculated amount of the above allowable deflection. With stages; (E) Applying welding force to the first and second face sheets, this first face sheet By elastically bending both sides of the mandrel with the first face sheet and the corrugated sheet. The contacting step: (f) welding the second face sheet to the corrugated sheet; (g) a step of releasing the welding force; The above manufacturing method, including 11. (a) moving the panel with respect to the mandrel; e), (c) and (e) repeating the steps of (gin). A method of manufacturing a truss umbrella core sandwich panel according to Paragraph 10. 12. The length of the mandrel is significantly smaller than the length of the panel in the direction of the corrugation. A truss core sandwich panel according to claim 11, which is How to make 0 13. The mandrel is attached to the pattern to weld the second face sheet to the corrugated sheet. from one side of the panel to the other with respect to the panel, and the force is applied periodically and The truss-core sandwich package according to claim 12 is released. How to make flannel. 14. The force is applied to the first and second face sheets by a welding electrode. , a truss according to claim 10, 11, 12 or 13. How to make core sandwich panels.