A process for producing a six-crankshaft for a large reciprocating compressor and its torsion handle fixture.

Abstract

This invention belongs to the technical field of forging industry, specifically relating to a process method and torsion handle tooling for producing six-handled crankshafts for large reciprocating compressors. The process involves forging the billet into a square shape, maximizing elongation efficiency after material separation, and eliminating folding phenomena. It is easy to control, reduces the number of forging passes, improves production efficiency, reduces machining allowances, avoids scrap, and allows for higher economic value. Six-handled crankshafts forged using this process have crankshaft angle tolerances all within 5mm, fully conforming to the drawing requirements.

Description

Technical Field

[0001] This invention belongs to the technical field of the forging industry, and specifically relates to the process method for producing a six-handle crankshaft for a large reciprocating compressor and its torsion handle tooling. Background Technology

[0002] The large six-crankshaft is the core component of the reciprocating compressor. The product quality requirements are high. There is a 120° angle between each crank of the crankshaft. If the angle is too large or too small, the crankshaft will not be able to be processed. Due to its complex shape, it is difficult to form and the scrap rate is high.

[0003] The traditional process involves opening the billet to a hexagonal shape and forging the crank shaft diameter at the hexagonal angle. Due to the 120° included angle limitation, the drawing efficiency is low, and it is difficult to control the crank angle during drawing. As a result, the angle is not correct and exceeds the machining allowance, leading to scrap. In order to improve the pass rate, the machining allowance can only be increased, which results in increased material costs. After drawing, the crank angle is formed and cannot be adjusted. Moreover, the crank root is very prone to folding.

[0004] Therefore, it is necessary to develop a manufacturing process for six-crankshafts that is easy to form, has low machining allowance, and low scrap rate. Summary of the Invention

[0005] To address the shortcomings of traditional technologies, this invention provides a process method and a torsion handle tooling for producing a six-handle crankshaft of a large reciprocating compressor. The process method provided in the first aspect of this invention is easy to form, reduces the number of forging passes and machining allowances, and eliminates the generation of waste products.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] A process for producing a six-crankshaft for a large reciprocating compressor specifically includes the following steps:

[0008] Step 1: Heat the billet to 1200℃, hold it at that temperature, and then forge it.

[0009] Step 2: After the billet is roughened, it is flattened, drawn out, and roughened again;

[0010] Step 3: Forge the cross-section into a square of a certain size;

[0011] Step 4: Cut and divide the material according to the required amount for each part;

[0012] Step 5: Lengthen each section. First, pull out the crank section, then pull out the shaft diameter section. After forging, the angle between the two cranks is approximately 90°.

[0013] Step 6: Insert the opening of the torsion bar tool into the two planes in the thickness direction of the crank. The crane lifts the load-bearing chain and twists the crank. Stop when the required angle is reached by measuring the template. Feed it forward and twist the next crank in the same way.

[0014] Step 7: Heat treatment process;

[0015] Step 8: Draw lines on the platform.

[0016] Furthermore, in step 2, the piercing is 1 / 2 of the height, the height-to-width ratio is 1:1.5, and the piercing is 1 / 3 of the height again.

[0017] Furthermore, in step 3, the dimension is the crankshaft flange dimension plus 50mm.

[0018] Furthermore, the method for preparing the torsion handle tool in step 6 is as follows:

[0019] The material is 16Mn, and it undergoes normalizing and tempering treatment. The heat treatment parameters are: heating to 910℃ and holding for 10 hours, then air cooling to 200℃ and holding for 3 hours, heating to 620℃ and holding for 18 hours, and then air cooling. The grain size is refined to ensure performance. The opening, lifting ring, and connecting hole are machined according to the drawings. One end is made into an opening shape according to the crank thickness, and the opening size matches the crank thickness. The opening length is greater than 2 / 3 of the crank width. The lifting rod is behind the opening and is connected to the lifting chain by the lifting ring and hung in the hook.

[0020] Furthermore, in step 6, the template is a triangle with interior angles of 30°, 60°, and 90°. The template is used to check the rotation in real time until the requirements are met.

[0021] A second aspect of the present invention provides a torsion bar tooling for a process of producing a six-crankshaft of a large reciprocating compressor, comprising: an opening adapted to the thickness of the crankshaft; a force-adding rod, one end of which is connected to the opening; a connecting hole formed in the force-adding rod; a lifting ring inserted inside the connecting hole of the lifting ring; and a lifting chain, one end of which is connected to the lifting ring, and the other end of which is adapted to be connected to a hook.

[0022] Furthermore, the opening and the extension rod are integrally forged.

[0023] Furthermore, there are two connection holes.

[0024] Compared with traditional processes, the beneficial effects of this invention are as follows.

[0025] 1. Traditional process involves forging the billet into a hexagonal shape and then forging the crankshaft diameter section at hexagonal angles. Due to the 120° included angle limitation, the drawing efficiency is low, the result is irregular, and the crank root is prone to folding. The process of this invention involves forging the billet into a square shape, which maximizes the drawing efficiency after material separation, is easy to operate, and eliminates folding.

[0026] 2. In traditional processes, the required 120° angle for each crank is achieved by adjusting the hexagonal angle during blank preparation. This places very high demands on the blank preparation process, and it is difficult to control the crank angle when the shaft diameter is lengthened. As a result, the angle may be incorrect and exceed the machining allowance, leading to scrap. To improve the yield rate, the machining allowance must be increased, resulting in increased material costs, longer processing cycles, and low production efficiency. The process method of this invention is to prepare the blank to a square shape. When lengthening the shaft diameter, the crank angle can be approximately 90°, making the operation simple.

[0027] 3. In traditional processes, after the shaft diameter is lengthened, the crank angle is formed, and the crank cannot be further adjusted after it is formed. The process method of this invention is that after the shaft diameter is lengthened, the angle between the cranks can continue to be adjusted by using a matching torsion tool, which can be torsioned up to 120°.

[0028] 4. Through platform scribing inspection, the six crankshafts forged using this process all had crankshaft angle tolerances within 5mm, fully meeting the drawing requirements. The inspection of three forgings produced using this process also showed that they all met the drawing requirements, proving that this process can ensure the continuous and stable quality of products.

[0029] 5. The process of this invention is simpler and easier to control than the traditional process. The traditional process requires one heating cycle for each shaft diameter section to be drawn, and three heating cycles for three shaft diameters. This process completes the drawing in one heating cycle, saving two heating cycles and reducing the number of forging heating cycles. It improves production efficiency, reduces machining allowance, avoids the generation of scrap, and can produce higher economic value. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the torsion handle tool of the present invention.

[0031] Figure 2 This is a schematic diagram showing the fit between the torsion bar tool of the present invention and the crankshaft at one angle.

[0032] Figure 3 This is a schematic diagram showing the engagement of the torsion bar tool of the present invention with the crankshaft at another angle.

[0033] Figure 4 This is a schematic diagram of the dimensions of the finished crankshaft according to an embodiment of the present invention.

[0034] Explanation of icon numbers:

[0035] 1. Opening; 2. Adding rod; 3. Connecting hole; 4. Lifting ring; 5. Lifting chain; 6. Press hammer; 7. Lower anvil; 8. Crankshaft; 9. Crank. Detailed Implementation

[0036] The present invention is further illustrated by the following embodiments, but is not intended to limit the invention in any way. Any modifications or substitutions made based on the teachings of the present invention are within the scope of protection of the present invention.

[0037] Combination Figures 1 to 4 As shown, the process for producing a six-crankshaft large reciprocating compressor in this embodiment is as follows.

[0038] Step 1: Heat the 31.5T forged crankshaft billet to 1200℃, hold it at that temperature, and then remove it from the furnace;

[0039] Step 2: Use riser clamps to chamfer and roughen the billet to a height of 1600mm, then flatten and elongate it to a height of 1000mm, width 1500mm, and length 2675mm; then roughen the flattened billet again to a height of 890mm.

[0040] Step 3: Forge the cross-section into a square with a side length of 1080mm and a length of 3190mm;

[0041] Step 4: Cut the shoulder and divide the material according to the required material for each part: the length of the sprue + I + II part is 820mm, the length of the III + IV part is 715mm, the length of the V + VI part is 715mm, and the length of the VII + VIII + IX + riser part is 940mm;

[0042] Step 5: Lengthen each section. First, pull out crank sections II, IV, and VI, with dimensions of 1275mm*885mm*630mm. Then, pull out shaft diameter sections I, III, V, VII, VIII, and IX. After forging, the angle between the two cranks is approximately 90°.

[0043] Step 6: The torsion handle tooling is prepared as follows: it is forged into a flat square with steps, and the addition rod 2 is forged as a whole. The material is 16Mn. It is normalized and tempered. The heat treatment parameters are: heating to 910℃ and holding for 10 hours, then air cooling to 200℃ and holding for 3 hours, heating to 620℃ and holding for 18 hours, and then air cooling; the grains are refined to ensure the performance. One end is made into an opening shape according to the thickness of crank 9. The size of the opening 1 matches the thickness of crank 9. The length of the opening 1 is greater than 2 / 3 of the width of crank 9. The addition rod 2 is behind the opening 1. It is connected to the lifting chain 5 by the lifting ring 4 and hung in the hook.

[0044] Step 7: Insert the opening 1 of the torsion tool into both planes along the thickness direction of the crank. Use a crane to lift the load-bearing chain 5 and twist the crank 9. Stop when the required angle is reached after measuring the template. Move the crankshaft 8 forward. Twist the next crank 9 in the same way. Figure 2-3 As shown; the final product is a six-crankshaft, as shown. Figure 4 As shown.

[0045] Combination Figure 1As shown, the torsion handle fixture includes: an opening 1 that is adapted to the thickness of the crank; one end of a force-adding rod 2 connected to the opening 1; a connecting hole 3 opened in the force-adding rod 2; a lifting ring 4 passing through the connecting hole 3; one end of a lifting chain 5 connected to the lifting ring 4, and the other end of the lifting chain 5 adapted to be connected to a hook.

[0046] In one possible embodiment, such as Figure 1 As shown, there are two connection holes.

[0047] For example, the connecting hole near the opening 1 serves a stabilizing and balancing function, while the other serves a torsional function.

Claims

1. A process for producing a six-throw crankshaft for a large reciprocating compressor, characterized by, Specifically comprising steps of: Step 1, heating the blank to 1200℃, holding after furnace forging; Step 2, roughing the blank, flattening and elongating, roughing again; Step 3, forging the cross section into a certain size square; Step 4, cutting the shoulder and dividing the material according to the required material of each part; Step 5, elongating each part, first elongating the crank part, then elongating the shaft diameter part, the angle between the two cranks after forging is approximately 90°; Step 6, the crank twisting tool opening part is inserted into the thickness direction of the crank two planes, the crane hoists the load chain to twist the crank, the template measures the angle to the required angle and stops, and then forwards, and the next crank is twisted in the same way; Step 7, heat treatment process; Step 8, platform scribing; The preparation method of the crank twisting tool of step 6 is: Forging into a flat square with steps, forging the whole together with the force rod part, the material is selected as 16Mn, normalizing + tempering treatment, the heat treatment parameters are heating to 910℃ for 10h, then air cooling to 200℃ for 3h, heating to 620℃ for 18h, and then air cooling; refining the grain, ensuring the use performance, the opening part, the lifting ring and the connecting hole are machined according to the drawing requirements by machining; one end is made into an opening shape according to the thickness of the crank, the opening size is consistent with the thickness of the crank, the opening length is greater than 2 / 3 of the crank width, and the rear of the opening is the force rod, which is connected with the lifting chain and hung in the lifting hook.

2. The process method of manufacturing six-throw crankshaft for large reciprocating compressor as claimed in claim 1 wherein, In step 2, the roughing height is 1 / 2, the elongation height and width ratio is 1:1.5, and the second roughing height is 1 / 3.

3. The process method of manufacturing six-throw crankshaft for large reciprocating compressor as claimed in claim 1 wherein, In step 3, the size is the size of the crank flange part plus 50mm.

4. The process method of manufacturing six-throw crankshaft for large reciprocating compressor as claimed in claim 1 wherein, In step 6, the template is a triangle, the internal angles are 30°, 60° and 90° respectively, and the template is used for real-time detection during twisting, and the process stops when the required angle is reached.

5. The process method of manufacturing six-throw crankshaft for large reciprocating compressor as claimed in claim 1 wherein, The crank twisting tool comprises: An opening part, which is adapted to the thickness of the crank; A force rod, one end of the force rod is connected with the opening part; A connecting hole, which is opened in the force rod; A lifting ring, which is arranged inside the connecting hole; A lifting chain, one end of the lifting chain is connected with the lifting ring, and the other end of the lifting chain is adapted to be connected with a lifting hook.

6. The process method of manufacturing six-throw crankshaft for large reciprocating compressor as claimed in claim 5 wherein, Comprise: The opening part and the force rod are integrally forged.

7. The process method of manufacturing six-stranded crankshaft for large reciprocating compressor as claimed in claim 5 wherein, Comprise: The number of connecting holes is two.

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