A method for forming an ultra-narrow air gap heat storage block

Abstract

The application belongs to the technical field of mechanical manufacturing, and discloses a forming method of super-narrow air gap heat storage block, wherein the overall shape of the heat storage block is a square block, and 15 uniform super-narrow air gaps are formed in the inner cavity by 14 partition plates; the specific forming method comprises the following steps: S1, heat storage block blank design: a machining allowance of 3mm is designed on each surface of the heat storage block blank, and the inner cavity part of the partition plates is not cast, namely, the first, third, fifth, seventh, eighth, tenth, twelfth and fourteenth partition plates from left to right are not cast, and positioning grooves and welding bevels are cast at the positions of the non-cast partition plates; S2, machining; S3, plate insertion and welding: the machined plate is inserted into the positioning groove of the heat storage block blank, the end surface is flush, the welding wire is inserted into the plate positioning hole bottom through the positioning hole of the heat storage block blank, and the gap between the cast partition plate and the inserted plate is adjusted through the pad; and S4, post-welding heat treatment. The application is economical, convenient and has a small operation difficulty.

Description

Technical Field

[0001] This invention belongs to the field of mechanical manufacturing technology, and in particular relates to a method for forming an ultra-narrow air gap heat storage block. Background Technology

[0002] The heat storage block is an ultra-narrow air gap structure, with an outer contour of a square cylinder of 140mm×140mm×200mm and a wall thickness of 5.5mm-6mm. Internally, it consists of 14 alternating 6mm baffles and 15 3mm air gaps. A front view is attached. Figure 1 As shown, the top view is attached. Figure 2 As shown.

[0003] Because the ratio of the depth to the thickness of the air gap structure in the product is large, and the absolute value of the thickness is small, only 3mm, and the number of such air gaps in a product is 15, it belongs to a porous structure with an ultra-large depth-to-width ratio. It is generally formed by casting with a core or by layered welding.

[0004] The casting process with cores requires setting 15 large flat cores within a 3mm air gap, which is difficult to operate and results in a long core cleaning cycle. The layered welding process requires the fabrication of specialized welding fixtures, and has poor dimensional stability and uniformity, high residual stress, and is prone to deformation in prolonged high-temperature environments. Summary of the Invention

[0005] The technical problem to be solved by this invention is a series of issues such as high operational difficulty, long cleaning cycle, and poor dimensional stability in the direct manufacturing and welding of heat storage block parts.

[0006] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows:

[0007] A method for forming an ultra-narrow air gap heat storage block, wherein the heat storage block is generally square in shape, and the inner cavity is divided into 15 uniform ultra-narrow air gaps by 14 partitions. The specific forming method includes the following steps:

[0008] S1, Design of heat storage block blank

[0009] The design allows for a machining allowance of 3mm on each side of the heat storage block blank. The internal cavity partitions are not cast out, that is, the 1st, 3rd, 5th, 7th, 8th, 10th, 12th and 14th partitions from left to right are not cast out. Positioning grooves and welding bevels are cast at the positions of the partitions that are not cast out.

[0010] S2, Machining

[0011] S2.1, Processing of heat storage block blanks

[0012] Positioning holes are machined in the positioning grooves of the heat storage block blank. Each positioning groove corresponds to two positioning holes, and the positioning holes are located at 1 / 3 of the height direction of the blank.

[0013] S2.2, Insert plate processing

[0014] Eight plates of the same material as the heat storage block blank, with a thickness of 5.9mm, are selected, and the edges are beveled. Welding bevels and positioning holes are machined to form insert plates. The positioning holes of the insert plates correspond to the positioning holes in the heat storage block blank.

[0015] S3, Insert plate welding

[0016] Insert the processed insert plate along the positioning groove of the heat storage block blank. After the end face is flush, cut the welding wire and insert it along the positioning hole of the heat storage block blank to the bottom of the positioning hole of the insert plate. Adjust the gap between the cast partition plate and the inserted insert plate by using the shim block. During the adjustment process, the overlap length between the insert plate and the shim block is controlled at 5-10mm. After the adjustment is completed, perform 4-point positioning welding in the length direction of the insert plate. Repeat the above operation until all 8 insert plates are positioned and welded as required.

[0017] S4. Post-weld heat treatment

[0018] Within 4 hours after welding, stress-relief annealing heat treatment should be carried out in an electric resistance furnace; the parts should be placed in the furnace with a spacing of not less than 20mm, the partitions of the parts should be in the vertical direction, and the height of the parts should not exceed 3 layers.

[0019] Furthermore, the positioning groove is designed with a width of 6.1mm and a depth of 1.5mm, and the two end faces of the positioning groove along the length direction are designed with 10mm×5mm welding bevels.

[0020] Furthermore, the bottom hole of the positioning hole is a Φ3.5mm through hole with an opening angle of 60° and an opening depth of 3mm.

[0021] Further, annealing heat treatment is performed; the heating temperature is 600℃-650℃, the heating rate is no more than 150℃ / h, the initial furnace temperature is no more than 200℃, and the holding time is 4h-6h. After being taken out of the furnace, the furnace is air-cooled to room temperature.

[0022] This invention has the following advantages: it uses a plate-insertion welding process to manufacture heat storage block parts. By processing plates of the same material into plates and inserting them into the positioning grooves of pre-made heat storage block blanks, inserting welding wire of the same grade into the positioning holes, and using hot welding processes such as argon arc welding for fusion welding and fixing, qualified ultra-narrow air gap heat storage block parts can be manufactured. This method is economical, convenient, and has low operation difficulty. Attached Figure Description

[0023] Appendix Figure 1 : Front view of the finished heat storage block;

[0024] Appendix Figure 2 Top view of the finished heat storage block;

[0025] Appendix Figure 3Process flow diagram;

[0026] Appendix Figure 4 : Main view of the heat storage block blank;

[0027] Appendix Figure 5 Top view of the heat storage block blank;

[0028] Appendix Figure 6 : Enlarged view of the heat storage block blank (AA);

[0029] Appendix Figure 7 : Main view of the machining of the positioning holes in the heat storage block blank;

[0030] Appendix Figure 8 : Enlarged view of the machining of positioning holes in the heat storage block blank;

[0031] Appendix Figure 9 Left view of the insert plate machining process;

[0032] Appendix Figure 10 Main view of the insert plate machining process;

[0033] Appendix Figure 11 : Enlarged view of the insert plate machining process (CC);

[0034] Appendix Figure 12 : Schematic diagram of insert plate positioning and tack welding;

[0035] Figure 12 Explanation of markings: 1. #1 welding bevel; 2. #2 welding bevel; 3. plug; 4. insert plate. Detailed Implementation

[0036] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0037] In this embodiment, the 15 ultra-narrow 3mm air gaps inside the heat storage block component pose a significant challenge in direct manufacturing. To meet the performance requirements of the final product while maintaining manufacturability, the heat storage block blank was redesigned, and some of the internal cavity partitions were not cast. (See attached...) Figure 2As shown, the 14 partitions inside the heat storage block, numbered 1 through 14 from left to right (1st, 3rd, 5th, 7th, 8th, 10th, 12th, and 14th), are not cast. This eliminates the 3mm ultra-narrow air gap structure, reducing the difficulty of casting. Positioning grooves and welding bevels are cast at the positions of the uncast partitions. Plates of the same material and specifications are inserted into the positioning grooves of the heat storage block blank. To ensure operability, the size of the positioning groove is slightly larger than the thickness of the inserted plate, ensuring smooth installation while allowing for some adjustment clearance to meet the dimensional requirements of the final product. Several auxiliary tool plugs, measuring 30mm × 10mm × 3mm, are made to adjust the gap between the cast partitions and the inserted plates, and the inserted plates are fixed in place by tack welding. After removing the plugs, the next plate is inserted, the gap is adjusted, and tack welded. After all plates are tack welded, they are welded together one by one to form the final product.

[0038] The manufacturing process of welding the heat storage block insert is as follows: Figure 3 As shown.

[0039] 1. Design of heat storage block blank

[0040] To meet the performance requirements of the final product while maintaining casting processability, the structure of the heat storage block blank was redesigned. The outer contour is a square cylinder, with a machining allowance of 3mm on each side (see attached). Figure 4 As shown), the inner cavity partition is not cast out, as per the attached diagram. Figure 2 As shown, the 14 baffles inside the heat storage block, numbered 1 through 14 from left to right (1st, 3rd, 5th, 7th, 8th, 10th, 12th, and 14th), are not cast. This eliminates the 3mm ultra-narrow air gap structure, reducing the difficulty of casting. Positioning grooves and welding bevels are cast at the locations of the uncast baffles. The positioning grooves are designed to be 6.1mm wide and 1.5mm deep (see attached diagram). Figure 5 As shown), the two end faces of the positioning groove along its length are designed with 10mm×5mm welding bevels (as shown in the attached image). Figure 6 (As shown).

[0041] 2. Machining

[0042] 2.1 Processing of heat storage block blanks

[0043] Positioning holes are machined on the heat storage block blank. These holes are designed on the outer surfaces of two flat plates with positioning grooves, with the center of the positioning hole coinciding with the center of the positioning groove. Each positioning groove corresponds to two positioning holes, located at 1 / 3 of the height of the blank. The bottom hole of the positioning hole is a Φ3.5mm through hole with an opening angle of 60° and an opening depth of 3mm. The machining process for the heat storage block blank is shown in the attached figure. Figure 7 Appendix Figure 8 As shown.

[0044] 2.2 Insert plate processing

[0045] Select a sheet material of the same type as the heat storage block blank, with a thickness of 5.9mm and rounded edges, and follow the instructions. Figure 9 The welding bevel is machined as shown. A Φ3.3mm × 3mm positioning hole is machined on the plate at the position corresponding to the positioning hole of the heat storage block blank, as shown in the attached diagram. Figure 10 Appendix Figure 11 As shown, a plug plate is formed.

[0046] 3. Insert plate welding

[0047] Insert the machined insert plate into the positioning groove of the heat storage block blank. After the end face is flush, cut a welding wire Φ3.2mm×6mm and insert it into the positioning hole of the heat storage block blank to the bottom of the positioning hole of the insert plate. Adjust the gap between the cast partition plate and the inserted insert plate using shims. During the adjustment process, control the overlap length between the insert plate and the shims to 5-10mm. After the adjustment is completed, perform 4-point tack welding in the length direction. (See attached image.) Figure 12 Perform tack welding in the order shown, and perform tack welding on the other side in the same position and order as the tack welding on this side.

[0048] Repeat the above steps until all 8 inserts are properly tack welded as required.

[0049] To minimize welding deformation, each insert plate was welded into shape according to the tack welding sequence, and then the positioning holes were welded by fusion welding. Welding wire with the same composition as the base material, Φ3.2mm in diameter, was selected. The process was argon arc welding, with a welding current of 80A-120A, a voltage of 12V-16V, and an argon flow rate of 12L / min-15L / min. Welding was performed in layers, with each layer not exceeding 3mm in thickness. The fusion welding at each positioning hole was completed in one pass.

[0050] 4. Post-weld heat treatment

[0051] Within 4 hours of welding, stress-relief annealing heat treatment is performed in an electric resistance furnace. The heating temperature is 600℃-650℃, the heating rate is no more than 150℃ / h, the initial furnace temperature is no more than 200℃, and the holding time is 4h-6h. After removing from the furnace, the parts are air-cooled to room temperature. The parts should be placed in the furnace with a spacing of no less than 20mm, the partitions should be vertical, and the height of the parts should not exceed 3 layers.

[0052] This embodiment solves a series of problems such as high operational difficulty, long cleaning cycle, and poor dimensional stability in the direct manufacturing and welding of heat storage block parts, and provides an economical, convenient, and less difficult method for forming heat storage block parts.

[0053] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art will be able to make various modifications and improvements without departing from the principles of the present invention, and these modifications and improvements should also be considered to fall within the scope of protection of the present invention.

Claims

1. A method for forming an ultra-narrow air gap heat storage block, characterized in that, The heat storage block is square in shape, and its inner cavity is divided into 15 uniform ultra-narrow air gaps by 14 partitions. The specific forming method includes the following steps: S1, Design of heat storage block blank The design allows for a machining allowance of 3mm on each side of the heat storage block blank. The internal cavity partitions are not cast out, that is, the 1st, 3rd, 5th, 7th, 8th, 10th, 12th and 14th partitions from left to right are not cast out. Positioning grooves and welding bevels are cast at the positions of the partitions that are not cast out. S2, Machining S2.1, Processing of heat storage block blanks Positioning holes are machined in the positioning grooves of the heat storage block blank. Each positioning groove corresponds to two positioning holes, and the positioning holes are located at 1 / 3 of the height direction of the blank. S2.2, Insert plate processing Eight plates of the same material as the heat storage block blank, with a thickness of 5.9mm, are selected, and the edges are beveled. Welding bevels and positioning holes are machined to form insert plates. The positioning holes of the insert plates correspond to the positioning holes in the heat storage block blank. S3, Insert plate welding Insert the processed insert plate along the positioning groove of the heat storage block blank. After the end face is flush, cut the welding wire and insert it along the positioning hole of the heat storage block blank to the bottom of the positioning hole of the insert plate. Adjust the gap between the cast partition plate and the inserted insert plate by using the shim block. During the adjustment process, the overlap length between the insert plate and the shim block is controlled at 5-10mm. After the adjustment is completed, perform 4-point positioning welding in the length direction of the insert plate. Repeat the above operation until all 8 insert plates are positioned and welded as required. S4. Post-weld heat treatment Within 4 hours after welding, stress-relief annealing heat treatment should be carried out in an electric resistance furnace; the parts should be placed in the furnace with a spacing of not less than 20mm, the partitions of the parts should be in the vertical direction, and the height of the parts should not exceed 3 layers.

2. The method for forming an ultra-narrow air gap heat storage block according to claim 1, characterized in that, The positioning groove is designed with a width of 6.1mm and a depth of 1.5mm, and the two end faces of the positioning groove along the length direction are designed with 10mm×5mm welding bevels.

3. The method for forming an ultra-narrow air gap heat storage block according to claim 1, characterized in that, The bottom hole of the positioning hole is a Φ3.5mm through hole with an opening angle of 60° and an opening depth of 3mm.

4. The method for forming an ultra-narrow air gap heat storage block according to claim 1, characterized in that, Annealing heat treatment; heating temperature is 600℃-650℃, heating rate is not greater than 150℃ / h, initial furnace temperature is not greater than 200℃, holding time is 4h-6h, and after taking it out of the furnace, it is air-cooled to room temperature.

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