Large-diameter pure titanium cylinder six-wheel power staggered spinning forming method

Abstract

This invention discloses a method for plastic forming of thick-walled cylindrical metal parts, specifically a six-wheel high-strength staggered-pitch spinning forming method for large-diameter pure titanium cylindrical parts, which includes the following steps: Step 1: According to the target product thickness T 1 Calculate the thickness T of the raw material 0 Compared to die spinning, the ultimate thinning rate of die spinning is higher. It can reach over 85%, and the thickness of the raw material T 0 for: The length of the raw material should be determined in conjunction with the processing allowance of the subsequent process and the determination of whether heat treatment test blocks are required. At the same time, the theoretical length should be calculated based on equal volume. The beneficial effects of this invention are: by setting multiple sets of inner and outer spinning wheels and combining them with staggered spinning process, a large material thinning rate can be achieved in one pass. By replacing the spinning die with an inner spinning wheel, the material processing efficiency is improved, the development cycle of the parts is shortened, and the mold investment cost is reduced. It is not only applicable to large-diameter cylindrical parts made of TA1 material, but also applicable to other large-diameter thick / thin-walled parts.

Description

A method for six-wheel high-strength staggered spinning forming of large-diameter pure titanium cylindrical parts Technical Field

[0001] This invention relates to the field of plastic forming technology for thick-walled cylindrical metal parts, specifically a six-wheel high-strength staggered spinning forming method for large-diameter pure titanium cylindrical parts. Background Technology

[0002] Large-diameter, thick-walled TA1 cylindrical parts are indispensable components in the aerospace and energy sectors, especially in gas cylinders, compartments, and cathode rollers, where they are key parts. They are not only corrosion-resistant but also offer significant advantages in weight reduction due to the high specific strength of pure titanium, thereby increasing equipment payload and reducing energy consumption. Currently, large-diameter, thick-walled TA1 cylindrical parts (diameter greater than φ2000mm, wall thickness ≥10mm) are mainly manufactured using multi-rotor die spinning or roll welding. Roll welding, however, introduces longitudinal weld seams, failing to meet the requirements of integrated manufacturing. This is particularly true for titanium cylinders used in cathode rollers, where the grain size deviation between the weld seam and the base material must be less than grade 1. Therefore, roll welding is gradually being phased out due to its low product yield.

[0003] Multi-rotor high-pressure spinning for producing TA1 cylindrical parts has been widely used. From the initial two-rotor to four-rotor processes, the spinning efficiency and finished product precision have improved significantly with the increase in the number of rotors. However, with the growing demand for new energy sources and the increasing size of parts, traditional die-casting suffers from drawbacks such as long mold manufacturing cycles, high costs, and easy wear. Furthermore, the thinning rate per pass in die-casting is limited by the stress state in the deformation zone; excessive thinning can lead to cracking defects, thus restricting production efficiency and product quality. Dieless flexible roller spinning offers significant advantages in forming large-diameter pure titanium cylindrical parts. Compared to die-casting, it achieves a higher degree of grain fragmentation and higher material processing efficiency. Summary of the Invention

[0004] In view of the problems existing in the current method for six-wheel high-strength staggered spinning of large-diameter pure titanium cylindrical parts, this invention is proposed.

[0005] Therefore, the purpose of this invention is to provide a six-wheel high-strength staggered-pitch spinning method for forming large-diameter pure titanium cylindrical parts. This method solves the problems of traditional die-spun spinning, such as long mold manufacturing cycle, high cost, and easy wear. Furthermore, the thinning rate of die-spun spinning is limited by the stress state in the deformation zone; excessive thinning can lead to cracking defects, which restricts production efficiency and product quality. Dieless flexible wheel spinning has significant advantages in forming large-diameter pure titanium cylindrical parts, offering higher grain fragmentation and material processing efficiency compared to die-spun spinning.

[0006] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:

[0007] A method for six-wheel high-strength staggered spinning forming of large-diameter pure titanium cylindrical parts, specifically including the following steps:

[0008] Step 1: Based on the thickness of the target product Calculate the thickness of raw materials Spinning with molds, and the ultimate thinning rate of spinning with rollers. Up to 85% or more, raw material thickness for: The length of the raw material should be determined in conjunction with the processing allowance of the subsequent process and the situation of whether heat treatment test blocks are required. At the same time, the theoretical length should be calculated based on equal volume.

[0009] Step 2: Set the thinning amount for each pass. , , ····, The equipment here uses four sets of spinning wheels for spinning processing;

[0010] Step 3: The spinning process employs a reverse flow spinning technique, meaning the direction of the spinning wheels is opposite to the direction of material flow. The principle for the offset of the spinning wheels along the length of the part is that wheels B and D should contact the material later than wheels A and C, and the step width formed by the two sets of spinning wheels should be less than 10mm. The offset of the spinning wheels along the diameter of the part is the material compression amount. The compression amount of wheels A and C is... The thinning amount of the inner rotating wheel is The thinning amount of the outer rotating wheel is ,

[0011] The downward pressure of the two sets of rotating wheels B and D is: The thinning amount of the inner rotating wheel is The thinning amount of the outer rotating wheel is

[0012] ;

[0013] Step 4: Spinning wheel profile design. Flexible spinning wheels do not require a supporting mold, therefore the shape of the spinning wheel affects the part forming accuracy. Here, a double-cone spinning wheel is used, with a forming angle... The radius of the rounded corners Exit corner ;

[0014] Step 5: Measure the gap based on the downward pressure calculated in Step 3. Since spinning is a dieless spinning method, there is no die as a reference, and it is impossible to use a feeler gauge to measure the gap between the die and the spinning wheel. Therefore, when designing the blank fixture at the spindle end, it is necessary to design one or more sets of reference rings or blocks to measure the reference gap and adjust the gap. It is necessary to measure the gap between the first set of inner spinning wheel and reference ring, the gap between the outer spinning wheel and reference ring, and the gap between the second set of inner spinning wheel and reference ring, and the gap between the outer spinning wheel and reference ring.

[0015] Step Six: Use a feeler gauge or standard gauge block to measure the gaps between the outer rotating wheel A, the inner rotating wheel A, the outer rotating wheel C, the inner rotating wheel C, and the reference ring. The gaps between the outer rotating wheel B, the inner rotating wheel B, the outer rotating wheel D, the inner rotating wheel D, and the reference ring are measured using feeler gauges or standard gauge blocks. ;

[0016] Step 7: Fix the blank. The blank is secured to the machine tool spindle fixture with 12 M24 screws to transmit the torque during the spinning process.

[0017] Step 8: Input the spinning parameters into the machine tool control system: rotation speed 20 rev / min, feed rate 20 mm / min; start the CNC program, use forced cooling for forming, with coolant spray devices inside and outside the deformation zone, and perform a trial spin. ,100≥ For a thickness of ≥50, the thickness of the test rotation length was measured using an ultrasonic thickness gauge, and the outer diameter was measured using a measuring tape. The relevant measurement data of the test rotation section were obtained.

[0018] Step 9: After the first spinning pass is completed, measure the total length dimension, including thickness, effective length, outer diameter, roundness, and straightness. If it meets the process control requirements, proceed with the second, third, ..., nth spinning passes. This completes all spinning passes for the part.

[0019] As a preferred embodiment of the six-wheel high-strength staggered-pitch spinning forming method for large-diameter pure titanium cylindrical parts described in this invention, in step one, the raw materials for the large-diameter pure titanium cylindrical parts are obtained by forging and machining, or by thick plate rolling and welding.

[0020] As a preferred embodiment of the six-wheel high-strength staggered-pitch spinning forming method for large-diameter pure titanium cylindrical parts described in this invention, in step one, when determining whether a heat-treated test block is required, the clamping allowance and the end machining allowance need to be considered. The clamping allowance is 50mm, and the end machining allowance is 100mm.

[0021] As a preferred embodiment of the six-wheel high-strength staggered spinning forming method for large-diameter pure titanium cylindrical parts described in this invention, in step two, the four sets of spinning wheels are evenly distributed at 90° intervals in the same plane.

[0022] As a preferred embodiment of the six-wheel high-strength staggered spinning forming method for large-diameter pure titanium cylindrical parts described in this invention, in step five, the reference gap is measured by optical measurement, specifically by a distance sensor device on the equipment.

[0023] As a preferred embodiment of the six-wheel high-strength staggered spinning forming method for large-diameter pure titanium cylindrical parts described in this invention, in step eight, the measured data is compared with the theoretical data of the process scheme. If they match, full-length spinning is performed. If there is a deviation, the spinning process parameters should be adjusted.

[0024] As a preferred embodiment of the six-wheel high-strength staggered-pitch spinning forming method for large-diameter pure titanium cylindrical parts described in this invention, wherein: in step four, Set it between 18-30°.

[0025] As a preferred embodiment of the six-wheel high-strength staggered-pitch spinning forming method for large-diameter pure titanium cylindrical parts described in this invention, wherein: This represents the theoretical thinning amount of the blank produced by the spinning wheel in the nth pass.

[0026] As a preferred embodiment of the six-wheel high-strength staggered-pitch spinning forming method for large-diameter pure titanium cylindrical parts described in this invention, wherein: This represents the theoretical thinning amount of the blank produced by the spinning wheel in the nth pass.

[0027] As a preferred embodiment of the six-wheel high-strength staggered-pitch spinning forming method for large-diameter pure titanium cylindrical parts described in this invention, wherein: in step two, the thinning rate of each pass and the total thinning rate of the four outer spinning wheels and four inner spinning wheels conform to the following relationship: .

[0028] Compared with existing technologies:

[0029] By setting multiple sets of inner and outer spinning wheels and combining them with staggered spinning process, a large material thinning rate can be achieved in one pass. By replacing the spinning die with an inner spinning wheel, the material processing efficiency is improved, the development cycle of parts is shortened, and the cost of die investment is reduced.

[0030] This invention is not only applicable to large-diameter pure titanium cylindrical parts made of TA1 material, but also to other large-diameter thick-walled / thin-walled parts. Attached Figure Description

[0031] Figure 1 is a top view of the position and distribution of the spinning wheels in the double-wheel spinning process provided by the present invention;

[0032] Figure 2 is a partially enlarged view of the gap setting provided by the present invention;

[0033] Figure 3 is a structural diagram of the spinning wheel provided by the present invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0035] This invention provides a method for six-wheel high-strength staggered spinning forming of large-diameter pure titanium cylindrical parts, as shown in Figures 1-3, including the following steps:

[0036] Step 1: Based on the thickness of the target product Calculate the thickness of raw materials Spinning with molds, and the ultimate thinning rate of spinning with rollers. Up to 85% or more, raw material thickness for: The length of the raw material should be determined in conjunction with the machining allowance of subsequent processes, whether heat treatment test blocks are required, etc. (clamping allowance and end machining allowance need to be considered; clamping allowance is 50mm, and end machining allowance is 100mm). The theoretical length should be calculated based on equal volume. Large-diameter pure titanium cylindrical parts are obtained through forging and machining, or by rolling and welding thick plates.

[0037] Step 2: Set the thinning amount for each pass. , , ····, The equipment here uses four sets of spinning wheels (evenly distributed every 90° in the plan view) for spinning processing (four outer spinning wheels and four inner spinning wheels, as shown in the figure A, B, C, and D, with A and C on a horizontal line and B and D on a horizontal line).

[0038] The thinning rate of each pass and the total thinning rate conform to the following relationship:

[0039] Step 3: The spinning process employs a reverse flow spinning technique, meaning the direction of the spinning wheels is opposite to the direction of material flow. This invention uses four pairs of wheels as an example, with each pair of wheels staggered; the number of other pairs of wheels follows the same principle. The principle for the staggered distance of the spinning wheels along the length of the part is that wheels B and D should contact the material later than wheels A and C, and the step width formed by the two sets of wheels should be less than 10mm. The staggered distance of the spinning wheels along the diameter of the part is the material reduction amount (thinning amount). The reduction amount of the two sets of wheels A and C (two inner wheels and two outer wheels) (the reduction amount is the theoretical thinning amount of the nth spinning pass blank) is... The thinning amount of the inner rotating wheel is The thinning amount of the outer rotating wheel is (Equal distribution of total downward pressure across all passes between the inner and outer rotating wheels).

[0040] The downward pressure of the two sets of spinning wheels (two inner spinning wheels and two outer spinning wheels) (the downward pressure is the theoretical thinning amount of the blank in the nth spinning pass) is: The thinning amount of the inner rotating wheel is The thinning amount of the outer rotating wheel is (Equal distribution of total downward pressure across all passes between the inner and outer rotating wheels).

[0041]

[0042] Step 4: Spinning wheel profile design. Flexible spinning wheels do not require a supporting mold, therefore the shape of the spinning wheel affects the part forming accuracy. Here, a double-cone spinning wheel is used, with a forming angle... (Forming angle between 18-30°), forming fillet radius Exit corner .

[0043] Step 5: Measure the clearance based on the downward pressure calculated in Step 3. Since spinning is a dieless spinning method, there is no die as a reference, and a feeler gauge cannot be used to measure the clearance between the die and the spinning wheel. Therefore, when designing the blank clamp at the spindle end, one or more sets of (stepped) reference rings / blocks (there should be inner and outer sets of reference rings / blocks) should be designed for measuring the reference clearance and adjusting the clearance. Alternatively, optical measurement can be used (the equipment should be equipped with a distance sensor). It is necessary to measure the clearance between the first set of inner spinning wheels and the reference ring, the outer spinning wheel and the reference ring, and the second set of inner spinning wheels and the reference ring, and the outer spinning wheel and the reference ring.

[0044] Step Six: Use a feeler gauge or standard gauge block to measure the gaps between the outer rotating wheel A, the inner rotating wheel A, the outer rotating wheel C, the inner rotating wheel C, and the reference ring. The gaps between the outer rotating wheel B, the inner rotating wheel B, the outer rotating wheel D, the inner rotating wheel D, and the reference ring are measured using feeler gauges or standard gauge blocks. .

[0045] Step 7: Fix the blank. The blank is secured to the machine tool spindle fixture with 12 M24 screws to transmit the torque during the spinning process.

[0046] Step 8: Input the spinning parameters into the machine tool control system: rotation speed 20 rev / min, feed rate 20 mm / min. Start the CNC program and use forced cooling for forming. Coolant spray devices are located inside and outside the deformation zone. Perform a trial spin. (100≥) (≥50) The thickness of the test-spinning length was measured using an ultrasonic thickness gauge, and the outer diameter was measured using a measuring tape. Relevant measurement data for the test-spinning section were obtained. The measurement data was compared with the theoretical data from the process plan. If they matched, full-length spinning was performed; otherwise, the spinning process parameters were adjusted.

[0047] Step 9: After the first spinning pass is completed, measure the total length dimension, including thickness, effective length, outer diameter, roundness, and straightness. If it meets the process control requirements, proceed with the second, third, ..., nth spinning passes. This completes all spinning passes for the part.

[0048] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for six-wheel high-strength staggered spinning forming of large-diameter pure titanium cylindrical parts, characterized in that, Specifically, the following steps are included: Step 1: Based on the thickness of the target product Calculate the thickness of raw materials Raw material thickness for: The length of the raw material should be determined in conjunction with the processing allowance of subsequent processes and the condition of the test block for heat treatment, while the theoretical length should be calculated based on equal volume; Step 2: Set the thinning amount for each pass. ， ，····， The equipment here uses four sets of spinning wheels for spinning processing; Step 3: The spinning process uses a reverse flow spinning process, that is, the direction of the spinning wheel movement is opposite to the direction of material flow; the principle of the offset of the spinning wheels in the length direction of the part is that spinning wheels B and D should contact the material later than spinning wheels A and C, and the step width formed by the two sets of spinning wheels should be less than 10mm; the offset of the spinning wheels in the diameter direction of the part is the material pressing amount, and the pressing amount of spinning wheels A and C is... The thinning amount of the inner rotating wheel is The thinning amount of the outer rotating wheel is The downward pressure of the two sets of rotating wheels, B and D, is The thinning amount of the inner rotating wheel is The thinning amount of the outer rotating wheel is ， Step 4: Spinning wheel profile design. Flexible spinning wheels do not require a supporting mold, therefore the shape of the spinning wheel affects the part forming accuracy. Here, a double-cone spinning wheel is used, with a forming angle... The radius of the rounded corners Exit corner Step 5: Measure the gap based on the downward pressure calculated in Step 3. Since spinning is a dieless spinning method, without a die as a reference, it is impossible to use a feeler gauge to measure the gap between the die and the spinning wheel. Therefore, when designing the blank clamp at the spindle end, one or more sets of reference rings need to be designed for measuring and adjusting the reference gap. It is necessary to measure the gaps between the first set of inner spinning wheels and the reference rings, the outer spinning wheel and the reference rings, and the second set of inner spinning wheels and the reference rings. Step 6: Use a feeler gauge or standard gauge block to measure the gaps between outer spinning wheel A, inner spinning wheel A, outer spinning wheel C, inner spinning wheel C, and the reference rings. The gaps between the outer rotating wheel B, the inner rotating wheel B, the outer rotating wheel D, the inner rotating wheel D, and the reference ring are measured using feeler gauges or standard gauge blocks. Step 7: Fix the blank. The blank is locked to the machine tool spindle fixture with 12 M24 screws to transmit the torque during the spinning process. Step 8: Input the spinning parameters into the machine tool control system: rotation speed 20 rev / min, feed rate 20 mm / min. The CNC program is started, and forced cooling is used for forming. There are coolant spray devices inside and outside the deformation zone. Trial rotation is performed. The thickness of the test spin length was measured using an ultrasonic thickness gauge, and the outer diameter was measured using a ruler, thus obtaining the relevant measurement data of the test spin section; Step 9: After the first spin pass is completed, the full length dimension is measured, including thickness, effective length, outer diameter, roundness, and straightness. If it meets the process control requirements, the second, third, ..., nth spin passes are performed, thus completing all spin passes of the part.

2. The method for six-wheel high-strength staggered spinning forming of a large-diameter pure titanium cylindrical part according to claim 1, characterized in that, In step one, the raw materials for the large-diameter pure titanium cylindrical parts are obtained through forging and machining, or through thick plate rolling and welding.

3. The method for six-wheel high-strength staggered spinning forming of a large-diameter pure titanium cylindrical part according to claim 1, characterized in that, When determining whether a heat-treated test block is needed in step one, the clamping allowance and the end machining allowance need to be considered. The clamping allowance is 50mm and the end machining allowance is 100mm.

4. The method for six-wheel high-strength staggered spinning forming of a large-diameter pure titanium cylindrical part according to claim 1, characterized in that, In step two, the four sets of rotating wheels are evenly distributed at 90° intervals in the same plane.

5. The method for six-wheel high-strength staggered spinning forming of a large-diameter pure titanium cylindrical part according to claim 1, characterized in that, In step five, the reference gap is measured using optical measurement, specifically through a distance sensor device on the equipment.

6. The method for six-wheel high-strength staggered spinning forming of a large-diameter pure titanium cylindrical part according to claim 1, characterized in that, In step eight, the measured data is compared with the theoretical data of the process plan. If they match, full-length spinning is performed. If there is a deviation, the spinning process parameters should be adjusted.

7. The method for six-wheel high-strength staggered spinning forming of a large-diameter pure titanium cylindrical part according to claim 1, characterized in that, In step four, Set it between 18-30°.

8. The method for six-wheel high-strength staggered spinning forming of a large-diameter pure titanium cylindrical part according to claim 1, characterized in that, In step three, This represents the theoretical thinning amount of the blank produced by the spinning wheel in the nth pass.

9. The method for six-wheel high-strength staggered spinning forming of a large-diameter pure titanium cylindrical part according to claim 1, characterized in that, In step three, This represents the theoretical thinning amount of the blank produced by the spinning wheel in the nth pass.

10. The method for six-wheel high-strength staggered spinning forming of a large-diameter pure titanium cylindrical part according to claim 1, characterized in that, In step two, the thinning rate of each pass and the total thinning rate of the four outer rotating wheels and four inner rotating wheels conform to the following relationship: 。

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