Self-tightening and self-centering inner support device and method for necking spinning of a drum-shaped part

Abstract

The present application belongs to the technical field of necking spinning forming equipment for metal cylinder, and particularly relates to a self-tightening and self-centering inner support device and method for necking spinning of a waist drum-shaped part. The present application comprises a positioning mandrel, a plurality of circumferentially distributed split expanding dies, a tight driving assembly and a torque transmission and floating connection assembly. The present application can complete spinning forming through one-time clamping and positioning, and can be quickly unloaded from the inner support tool after the workpiece is formed, without the need for reversing and re-clamping for secondary spinning. The present application not only prevents the workpiece from generating a large form tolerance, thereby ensuring the dimensional accuracy of the workpiece, but also improves the production efficiency of the waist drum-shaped workpiece. The present application can realize tightness and loosening through the rotation of an outer adjusting cylinder, and is simple and quick to operate, thereby significantly improving the clamping and unloading efficiency. The present application can adapt to the spinning requirements of cylindrical parts with different inner diameters and different shapes by replacing split expanding dies with different shapes or adjusting the expansion stroke, and has good versatility.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of necking spinning forming equipment for metal cylinder, and particularly relates to a self-tightening and self-centering inner support device and method for necking spinning of a waist drum-shaped part. BACKGROUND

[0002] Necking spinning is a forming method that uses a spinning tool (spinning wheel, etc.) to make a rotary body hollow part or a tubular blank rotate radially and locally to reduce its diameter and change its shape. In the necking spinning process, the cylinder blank is clamped concentrically in a suitable core mold (such as a solid core, a combination, or a coreless mold), and the part to be formed is exposed to the outside of the clamping fixture. When the main shaft rotates the blank, according to the control mode adopted, the spinning wheel moves back and forth according to the specified shape trajectory, gradually reducing the diameter of the blank, and further obtaining a waist drum-shaped workpiece.

[0003] The necking spinning method is often used to process waist drum-shaped parts with a rough middle and thin ends. The inner support tooling used is one of the key devices of this process technology. The usual method of necking spinning of a waist drum-shaped part is to spin one end and then spin the other end, which not only makes the processing procedure cumbersome and the processing efficiency low, but also makes it difficult to accurately position the waist drum-shaped part during spinning. The second time the workpiece is clamped and positioned will cause the workpiece to have a large form and position tolerance, reducing the dimensional accuracy and quality of the product. Based on the above-mentioned existing problems, there is an urgent need for a self-tightening and self-centering inner support device for necking spinning of a waist drum-shaped part, which can complete the necking spinning of both ends of the waist drum-shaped part through one-time clamping. SUMMARY

[0004] The present application provides a self-tightening and self-centering inner support device and method for necking spinning of a waist drum-shaped part, which aims to solve the problem of unstable product dimensional accuracy and low production efficiency caused by the cumbersome processing procedure and large form and position tolerance of the second time the workpiece is clamped and positioned in the traditional necking spinning process, break through the technical constraints of traditional necking spinning equipment, and achieve one-time clamping and two-end one-time forming of the waist drum-shaped part, thereby improving the process reliability and production efficiency. Through the present application, automatic fitting and high-precision centering of the inner support device and the inner wall of the workpiece can be achieved, providing stable inner support, and the inner support device can be smoothly retracted after spinning to be removed from the waist drum-shaped workpiece.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows:

[0006] A self-tightening and self-centering inner support device for necking spinning of a waist drum-shaped part, comprising,

[0007] a positioning core shaft;

[0008] a plurality of circumferentially distributed split expansion molds, the inner side of which is provided with a T-shaped groove and an inclined wedge surface;

[0009] a tensioning drive assembly for driving the radial movement of the split expander, comprising:

[0010] a hexagonal expander core, which is circumferentially provided with a plurality of wedge surfaces, each of which is slidably connected to the inner side of a corresponding split expander via a second T-shaped bar;

[0011] an inner adjusting cylinder rigidly connected to the hexagonal expander core;

[0012] an outer adjusting cylinder threadedly connected to the inner adjusting cylinder;

[0013] a torque transmission and floating connection assembly for transmitting torque and allowing the radial floating of the split expander, comprising:

[0014] a force transmission cylinder, one end of which is used to connect to the main shaft of the spinning machine, and the other end is slidably connected to each of the split expanders via a first T-shaped bar;

[0015] The hexagonal expander core, inner adjusting cylinder, outer adjusting cylinder and force transmission cylinder are all sleeved on the positioning mandrel; rotating the outer adjusting cylinder can drive the axial movement of the inner adjusting cylinder and hexagonal expander core, and then drive all the split expanders to move radially synchronously through the action of the wedge surfaces.

[0016] The force transmission cylinder is fixedly connected to one end of the positioning mandrel via a first circular nut and an anti-rotation key.

[0017] The outer adjusting cylinder is installed on the positioning mandrel via a positioning ring and a second circular nut.

[0018] The hexagonal expander core is rigidly connected to the inner adjusting cylinder via a flange ring and a third screw.

[0019] The first T-shaped bar and the second T-shaped bar are respectively embedded in the T-shaped groove of the corresponding split expander, forming a pair of motion pairs that allow the split expander to slide radially, while limiting its circumferential and axial displacement.

[0020] When the split expander is completely radially contracted, the maximum envelope circle diameter of its outer contour is smaller than the minimum inner diameter of the processed barrel.

[0021] The outer working surface of the split expander is shaped to match the shape of the inner surface of the barrel blank to be formed.

[0022] A method for neck spinning of a barrel using a self-tensioning and self-centering internal support device for neck spinning of a barrel, comprising the following steps:

[0023] S1. Clamping and positioning;

[0024] Clamp the force transmission cylinder on the spinning machine chuck, and sleeve the barrel blank outside the split expander, and pass the positioning mandrel through each component and clamp it by the spinning machine tail.

[0025] S2. Swelling centering;

[0026] Rotating the outer adjusting cylinder drives the inner adjusting cylinder and the hexagonal swelling mandrel to move axially, and through the action of the inclined wedge surface, all the split swelling dies are synchronously expanded radially until they are fully attached to the inner wall of the cylinder blank.

[0027] S3. Spinning forming;

[0028] Starting the spinning machine, the spindle drives the tooling and the cylinder blank to rotate, and the first spinning roller and the second spinning roller respectively perform necking spinning on both ends of the cylinder blank to form a barrel-shaped cylinder.

[0029] S4. Unloading;

[0030] Reversely rotating the outer adjusting cylinder drives the split swelling dies to synchronously contract radially until they are separated from the inner wall of the workpiece, and the maximum envelope circle diameter of the outer contour is smaller than the minimum inner diameter of the barrel-shaped cylinder, and the tooling is extracted.

[0031] In step S2, swelling is achieved by rotating the outer adjusting cylinder, which is performed in the tail top tight state of the spinning machine.

[0032] In step S3, the transmission path of the spinning torque is: the spinning machine chuck, the force transmission cylinder, the first T-shaped strip, the split swelling die to the cylinder blank.

[0033] Advantages:

[0034] 1. The split swelling die structure adopted by the present application is composed of a split swelling die and a hexagonal swelling core, and the swelling and contraction thereof are achieved through the inclined wedge surfaces uniformly distributed in the circumferential direction of the hexagonal swelling core. In order to prevent the hexagonal swelling core and the split swelling die from being separated during contraction, a T-shaped groove and a T-shaped strip are arranged between the two plane pairs. The swelling and contraction of the split swelling die are achieved through the linear motion of the hexagonal swelling core along the central axis, and the linear motion of the hexagonal swelling core along the central axis is achieved by rotating the outer adjusting cylinder and pushing and pulling the inner adjusting cylinder through the threads. The split swelling die structure composed of the split swelling die and the hexagonal swelling core can achieve swelling and automatic centering of the cylinder blank without additional adjustment when swelling; the inner support tooling can complete the spinning forming of both ends of the barrel-shaped cylinder through one-time clamping and positioning.

[0035] 2. After the workpiece is formed, it can be quickly unloaded from the inner support tooling without needing to reverse and re-clamp for secondary spinning. The necking spinning process of both ends of the workpiece and the unloading process are completed through one-time clamping, which not only prevents the workpiece from generating a large form tolerance to ensure the dimensional accuracy of the workpiece, but also improves the production efficiency of the barrel-shaped workpiece.

[0036] 3、The self-centering precision of the present application is high. The present application adopts a multi-segment synchronous radial expansion mechanism, can automatically adapt to the inner circle error of the cylinder blank, makes each segment uniformly contact the inner wall, realizes high-precision automatic centering, and ensures uniform wall thickness of the workpiece after spinning.

[0037] 4、The present application is convenient and reliable in unloading. The segmented expansion die adopted by the present application can be radially contracted to a maximum envelope circle diameter smaller than the size of the minimum inner diameter of the workpiece, so that it can be easily taken out axially from the formed waist drum-shaped cylinder (large in the middle and small at both ends), solving the problem of unloading of special-shaped inner cavity workpieces.

[0038] 5、The present application has good support rigidity and reliable torque transmission. The segmented expansion die of the present application contacts the inner wall of the workpiece after expansion, has large support area and good rigidity; the torque is directly transmitted to the segmented expansion die through the force transmission cylinder and the T-shaped bar, the structure is compact, the force transmission path is short, and the rigidity is strong.

[0039] 6、The present application is simple and efficient to operate. The present application can realize expansion and loosening by only rotating the outer adjusting cylinder, which is simple and fast, and significantly improves the clamping and unloading efficiency.

[0040] 7、The present application has strong universality and adjustability. The present application can adapt to the spinning requirements of cylindrical parts with different inner diameters and different shapes by replacing segmented expansion dies with different shapes or adjusting the expansion stroke, and has good universality.

[0041] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application and can be implemented according to the content of the specification, the following will be described in detail with the preferred embodiments of the present application and with the help of the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0043] Figure 1 is the principle and implementation structure diagram of the present application.

[0044] Figure 2 is the spinning process diagram of the present application.

[0045] Figure 3 is the waist drum-shaped workpiece taking-out process diagram after spinning.

[0046] Figure 4 is Figure 1 A-A sectional view of

[0047] Figure 5 is Figure 3 a B-B sectional view of

[0048] Figure 6 is Figure 3 a C-C partial sectional view of

[0049] Figure 7 is Figure 3 a D-D partial sectional view of

[0050] Figure 8 is a flow chart of the present application.

[0051] In the figure: 1, first round nut; 2, anti-rotation key; 3, power transmission cylinder; 4, positioning mandrel; 5, cylinder blank; 6, first screw; 7, first T-shaped strip; 8, split expanding die; 9, second T-shaped strip; 10, second screw; 11, hexagonal expanding core; 12, third screw; 13, flange pressing ring; 14, inner adjusting cylinder; 15, outer adjusting cylinder; 16, positioning pressing ring; 17, second round nut; 18, spinning machine chuck; 19, first spinning wheel; 20, waisted drum-shaped cylinder; 21, spinning machine tail top; 22, second spinning wheel. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0053] Embodiment one:

[0054] With reference to Figures 1-7 , a self-expanding self-centering inner support device for necking spinning of a waisted drum-shaped part, comprising,

[0055] a positioning mandrel 4;

[0056] a plurality of split expanding dies 8 distributed uniformly in the circumferential direction, the inner side of each split expanding die 8 being provided with a T-shaped groove and an inclined wedge surface;

[0057] an expanding drive assembly for driving the split expanding dies 8 to move radially, comprising:

[0058] a hexagonal expanding core 11, the circumferential surface of which is provided with a plurality of inclined wedge surfaces, each inclined wedge surface being connected to the inner side of a corresponding split expanding die 8 through a second T-shaped strip 9;

[0059] an inner adjusting cylinder 14, rigidly connected to the hexagonal expanding core 11;

[0060] an outer adjusting cylinder 15, threadedly connected to the inner adjusting cylinder 14;

[0061] Torque transmission and floating connection assembly for transmitting torque and allowing the segmental bulging die 8 to radially float, comprising:

[0062] A force transmission cylinder 3, one end of which is used to connect the spinning machine spindle, and the other end is connected with each of the segmental bulging dies 8 through a first T-shaped strip 7 and a first screw 6.

[0063] The hexagonal bulging core 11, the inner adjusting cylinder 14, the outer adjusting cylinder 15 and the force transmission cylinder 3 are all sleeved on the positioning mandrel 4; rotating the outer adjusting cylinder 15 can drive the inner adjusting cylinder 14 and the hexagonal bulging core 11 to move axially, and then drive all the segmental bulging dies 8 to move radially synchronously through the action of the inclined wedge surface.

[0064] The positioning mandrel 4 serves as the center reference axis of the entire tooling. The segmental bulging die assembly is composed of a plurality of segmental bulging dies 8 distributed uniformly in the circumferential direction, the outer side working surface of which is used to fit the inner wall of the workpiece, and the inner side of which is provided with a T-shaped groove and an inclined wedge surface. The hexagonal bulging core 11 is a multi-ribbed platform body (preferably a six-ribbed platform) with a plurality of inclined wedge surfaces uniformly distributed in the circumferential direction, each inclined wedge surface of which is in sliding fit with the T-shaped groove on the inner side of the corresponding segmental bulging die 8 through a second T-shaped strip 9; the hexagonal bulging core 11 is provided with a through hole in the center and is sleeved on the positioning mandrel 4. The inner adjusting cylinder 14 is rigidly connected with the hexagonal bulging core 11 through a flange pressing ring 13 and a third screw 12, and can drive the hexagonal bulging core 11 to move axially along the positioning mandrel 4. The outer adjusting cylinder 15 is sleeved on the positioning mandrel 4, and its axial movement is limited by a positioning pressing ring 16 and a second circular nut 17, and it can only rotate around the positioning mandrel 4; the outer adjusting cylinder 15 is connected with the inner adjusting cylinder 14 through a threaded pair. One end of the force transmission cylinder 3 is used to be clamped on the spinning machine chuck 18, the center through hole of which penetrates the positioning mandrel 4, and the end of the positioning mandrel is fixed relative to the force transmission cylinder through a first circular nut 1 and an anti-rotation key 2; the other end of the force transmission cylinder is connected with each of the segmental bulging dies 8 through a first T-shaped strip 7 and a first screw 6, allowing the segmental bulging dies 8 to move radially but not to be separated. The first screw 6 is composed of a plurality of pieces, and in this embodiment, there are 6 groups of 3 pieces each, a total of 6x3=18 pieces, which are uniformly distributed in the circumferential direction.

[0065] In specific application, the two ends of the positioning mandrel 4 are clamped by a clamping and positioning assembly including the spinning machine chuck 18 and the spinning machine tail top 21, to ensure that the self-bulging and self-centering inner support device for necking spinning of a waist drum-shaped part is coaxial with the spinning machine spindle.

[0066] Further, the force transmission cylinder 3 is fixedly connected to one end of the positioning mandrel 4 through the first circular nut 1 and the anti-rotation key 2.

[0067] Further, the outer adjusting cylinder 15 is installed on the positioning mandrel 4 through the positioning pressing ring 16 and the second circular nut 17.

[0068] Further, the hexagonal expander core 11 is rigidly connected with the inner adjusting cylinder 14 through the flange compression ring 13 and the third screw 12.

[0069] Further, the first T-shaped strip 7 and the second T-shaped strip 9 are respectively embedded into the T-shaped slot of the corresponding split expander die 8, forming a pair of motion that allows the split expander die 8 to slide radially, while limiting its circumferential and axial displacement.

[0070] Further, when the split expander die 8 is completely contracted radially, the maximum envelope circle diameter of its outer contour is smaller than the minimum inner diameter of the waist drum-shaped cylinder 20 that has been machined.

[0071] Further, the outer working surface shape of the split expander die 8 is matched with the inner surface shape of the to-be-formed cylinder blank 5.

[0072] In actual use, the working principle is as follows:

[0073] The positioning mandrel 4 passes through the force transmission cylinder 3, the hexagonal expander core 11, the inner adjusting cylinder 14 and the outer adjusting cylinder 15 in turn, and the force transmission cylinder 3, the hexagonal expander core 11, the inner adjusting cylinder 14 and the outer adjusting cylinder 15 are coaxial with the positioning mandrel 4 through hole fitting; the first circular nut 1 positions the force transmission cylinder 3 at the left end of the positioning mandrel 4, and the anti-rotation key 2 can ensure that the two do not rotate relative to each other; the hexagonal expander core 11 and the inner adjusting cylinder 14 are rigidly connected through the flange compression ring 13 and the third screw 12, ensuring that the hexagonal expander core 11 follows the inner adjusting cylinder 14 to move along the positioning mandrel 4 in the first direction; the outer adjusting cylinder 15 is positioned at the right end of the positioning mandrel 4 through the positioning compression ring 16 and the second circular nut 17, ensuring that the outer adjusting cylinder 15 can only rotate around the axis of the positioning mandrel 4 and cannot reciprocate along the positioning mandrel 4 in the first direction, i.e. in the counterclockwise rotation direction around the axis of the outer adjusting cylinder 15; the force transmission cylinder 3 is floatingly connected with the split expander die 8 through the first T-shaped strip 7 and the first screw 6, ensuring that the split expander die 8 can reciprocate in the second direction, i.e. in the clockwise rotation direction around the axis of the force transmission cylinder 3, and does not disengage from the force transmission cylinder 3; the hexagonal expander core 11 is floatingly connected with each split expander die 8 through the first T-shaped strip 7 and the second screw 10, ensuring that the two can slide relative to each other and do not disengage, thereby realizing the reciprocating movement of the split expander die 8 in the second direction through the circumferentially distributed inclined wedge surfaces between them. The second screw 10 is provided in multiple pieces, and in this embodiment, there are 6 groups of 5 pieces each, which are circumferentially distributed in groups, for a total of 6x5=30 pieces.

[0074] Figure 2is a schematic diagram of the spinning process; first, the workpiece, i.e. the cylinder blank 5, is clamped, the clamping end (left end) of the transmission cylinder 3 is clamped in the spinning machine chuck 18, the positioning mandrel 4 passes through the transmission cylinder 3, the hexagonal expansion core 11, the inner adjusting cylinder 14, the outer adjusting cylinder 15 and the cylinder blank 5 in turn, and the other end of the positioning mandrel 4 is tightly pressed by the spinning machine tail top 21 to ensure that all parts are coaxial; during the expansion process, the outer adjusting cylinder 15 is rotated in the first rotational direction, and the outer adjusting cylinder 15 pushes the inner adjusting cylinder 14 to drive the hexagonal expansion core 11 to move in the first direction, the hexagonal expansion core 11 moves the split expansion die 8 in the second direction through the circumferentially distributed inclined wedge surfaces, and finally the split expansion die 8 is completely expanded and tightly fitted with the inner surface of the cylinder blank 5 through the rotation of the outer adjusting cylinder 15, and the split expansion die 8 is automatically centered.

[0075] Figure 3 is a schematic diagram of the unloading process. When the spinning process is completed, the outer adjusting cylinder 15 is rotated in the fourth rotational direction, i.e. opposite to the first rotational direction, and the outer adjusting cylinder 15 pulls the inner adjusting cylinder 14 to drive the hexagonal expansion core 11 to move in the fourth direction, i.e. towards the spinning machine tail top 21, the hexagonal expansion core 11 moves the split expansion die 8 in the fifth direction, i.e. towards the positioning mandrel 4, through the circumferentially distributed inclined wedge surfaces, the split expansion die 8 is finally completely retracted and separated from the inner surface of the cylinder blank 5 through the rotation of the outer adjusting cylinder 15, and the outer contour size of all split expansion dies 8 is smaller than the minimum inner hole size of the drum-shaped cylinder 20, so that the unloading process of the workpiece drum-shaped cylinder 20 after spinning can be realized.

[0076] Figure 4 is Figure 1 A-A sectional view of

[0077] Figure 5 is Figure 3The BB sectional view shows the fully retracted state of the segmented bulging mold 8. Under the joint constraint of the first T-strip 7 and the second T-strip 9, the segmented bulging mold 8 is finally completely retracted and separated from the inner surface of the cylindrical blank 5 by rotating the outer adjusting cylinder 15. Furthermore, the outer contour dimension Ød of all segmented bulging molds 8 is smaller than the minimum inner hole dimension ØD of the waist-shaped cylinder 20, thus realizing the unloading process of the waist-shaped cylinder 20 after spinning.

[0078] Figure 6 yes Figure 3 The partial sectional view of CC shows the state of the hexagonal expansion core 11 and the second T-shaped strip 9 after removing other components. The hexagonal expansion core 11 is a hexagonal frustum with six circumferentially distributed wedge-shaped surfaces. A second T-shaped strip 9 is set in the middle of each wedge-shaped surface. The second T-shaped strip 9 respectively cooperates with the T-shaped groove on the corresponding segmented expansion mold 8 to form a linear motion pair.

[0079] Figure 7 yes Figure 3 The partial sectional view of DD shows the hexagonal expansion core 11 and the inner adjusting cylinder 14 rigidly connected by the flange pressure ring 13 and the third screw 12. The positioning mandrel 4 passes through the hexagonal expansion core 11 and the inner adjusting cylinder 14 from the center. Multiple third screws 12 are used, a total of 12 in this embodiment, evenly distributed along the circumference.

[0080] Example 2:

[0081] Reference Figures 1-8 A method for spinning a waist-drum shaped component using a self-expanding, self-centering internal support device, comprising the following steps:

[0082] S1. Clamping and positioning;

[0083] The force transmission cylinder 3 is clamped in the spinning machine chuck 18, the cylinder blank 5 is placed on the outside of the split expansion mold 8, and the positioning mandrel 4 passes through each component and is pressed by the tail top 21 of the spinning machine.

[0084] S2. Tightening and centering;

[0085] Rotate the outer adjusting cylinder 15 to drive the inner adjusting cylinder 14 and the hexagonal expansion core 11 to move axially. Through the action of the inclined wedge surface, all the segmented expansion molds 8 are synchronously radially expanded until they are completely fitted and tightened against the inner wall of the cylinder blank 5.

[0086] Specifically, at this time, the outer adjusting cylinder 15 is rotated counterclockwise (i.e., the first rotation direction). Since the outer adjusting cylinder 15 is axially limited, its rotating movement is converted into the axial movement of the inner adjusting cylinder 14 and the six-sided expanding core 11 fixed thereto to the left (i.e., the first direction) through the threaded pair. When the six-sided expanding core 11 moves to the left, the six inclined wedge surfaces thereof push the six split expanding dies 8 along the T-shaped grooves thereof to move radially outward (i.e., the second direction) synchronously until the working surfaces of the split expanding dies 8 are fully attached to and expanded against the inner wall of the cylinder blank 5. Since each split part moves independently and synchronously, the non-circularity of the inner circle of the blank can be automatically compensated, and self-centering is achieved.

[0087] S3. spinning forming;

[0088] The spinning machine is started, the spindle drives the tooling and the cylinder blank 5 to rotate, and the first spinning roller 19 and the second spinning roller 22 perform neck spinning on both ends of the cylinder blank 5, respectively, to form a barrel-shaped cylinder 20;

[0089] Specifically, when the spinning machine is started, the spinning machine spindle drives the spinning machine chuck 18, the transmission cylinder 3, the first T-shaped strip 7, and the expanded split expanding die 8 to rotate together, and drives the cylinder blank 5 to rotate through friction. The first spinning roller 19 and the second spinning roller 22 perform synchronous neck spinning on both ends of the rotating cylinder blank 5 according to the program control, and gradually form a barrel-shaped cylinder 20. The expanded split expanding die 8 provides full circumferential internal support for the cylinder to prevent instability during spinning.

[0090] S4. unloading;

[0091] The outer adjusting cylinder 15 is rotated in the opposite direction (i.e., the fourth rotation direction or clockwise), which drives the split expanding die 8 to synchronously contract radially to disengage from the inner wall of the workpiece and the maximum envelope circle diameter of the outer contour is less than the minimum inner diameter of the barrel-shaped cylinder 20, and the tooling is extracted.

[0092] Further, in step S2, the expanding is achieved by rotating the outer adjusting cylinder 15, which is performed in the state that the spinning machine tail top 21 is tightened.

[0093] Further, in step S3, the transmission path of the spinning torque is: the spinning machine chuck 18, the transmission cylinder 3, the first T-shaped strip 7, the split expanding die 8 to the cylinder blank 5.

[0094] The present application completes the neck spinning machining and unloading process of both ends of the workpiece by one clamping, which not only prevents the workpiece from generating large form and position tolerances, guarantees the size accuracy of the workpiece, but also improves the production efficiency of the barrel-shaped workpiece.

[0095] In the case of no conflict, a person skilled in the art can combine the related technical features in the above examples according to the actual situation to achieve the corresponding technical effect. Specific to various combinations, this will not be repeated here.

[0096] It should be noted that all directional indications, such as upper, lower, left, right, front, back, etc., are merely used for convenience of explanation and are not intended to limit the scope of the application.

[0097] In addition, the terms "first", "second", and the like, as used herein, are intended to modify any and all property or characteristic that has been described in relation to an item, but do not imply that the modified item should be construed to be chronologically "first" or "second", unless otherwise indicated. Thus, a "first" and "second" feature can include one or both of the features.

[0098] The above description is merely illustrative of the application and is not intended to limit the scope of the application, which is defined by the appended claims. As such, any modifications, equivalent arrangements, and / or additions to the described embodiments that are in accordance with the spirit and scope of the application are to be considered within the scope of the application.

Claims

1. A self-expanding self-centering inner support device for necking spinning of a barrel-shaped workpiece, characterized by: Comprising, a positioning mandrel (4); a plurality of circumferentially distributed split expanders (8) with T-shaped grooves and inclined wedge surfaces on their inner sides; an expander driving assembly for driving the split expanders (8) to move radially, which comprises: a hexagonal expander core (11) with a plurality of inclined wedge surfaces circumferentially arranged, each of which is connected to the inner side of a corresponding split expander (8) through a second T-shaped bar (9); an inner adjusting cylinder (14) rigidly connected to the hexagonal expander core (11); an outer adjusting cylinder (15) connected to the inner adjusting cylinder (14) through threads; a torque transmission and floating connection assembly for transmitting torque and allowing the split expanders (8) to move radially, which comprises: a force transmission cylinder (3) with one end connected to the main shaft of a spinning machine and the other end connected to each of the split expanders (8) through a first T-shaped bar (7); the hexagonal expander core (11), the inner adjusting cylinder (14), the outer adjusting cylinder (15), and the force transmission cylinder (3) are all sleeved on the positioning mandrel (4); rotating the outer adjusting cylinder (15) can drive the inner adjusting cylinder (14) and the hexagonal expander core (11) to move axially, and then drive all the split expanders (8) to move radially synchronously through the action of the inclined wedge surfaces.

2. A self-expanding self-centering internal support device for necking spinning of a waisted drum, according to claim 1, characterized in that: The force transmission cylinder (3) is fixedly connected to one end of the positioning mandrel (4) through a first circular nut (1) and an anti-rotation key (2).

3. A self-expanding self-centering internal support device for necking spinning of a waisted drum, according to claim 1 or 2, characterized in that: The outer adjusting cylinder (15) is installed on the positioning mandrel (4) through a positioning pressure ring (16) and a second circular nut (17).

4. A self-expanding self-centering internal support device for necking spinning of a waisted drum, according to claim 1 or 2, characterized in that: The hexagonal expander core (11) is rigidly connected to the inner adjusting cylinder (14) through a flange pressure ring (13) and a third screw (12).

5. A self-expanding self-centering internal support device for necking spinning of a waisted drum, according to claim 1 or 2, characterized in that: The first T-shaped bar (7) and the second T-shaped bar (9) are respectively embedded in the T-shaped grooves of the corresponding split expanders (8), forming a pair of kinematic pairs that allow the split expanders (8) to move radially, while limiting their circumferential and axial displacement.

6. A self-expanding self-centering internal support device for necking spinning of a waisted drum, according to claim 1 or 2, characterized in that: When the split expanders (8) are completely radially contracted, the maximum envelope circle diameter of their outer contour is smaller than the minimum inner diameter of the processed barrel (20).

7. A self-expanding self-centering internal support device for necking spinning of a waisted drum, according to claim 1 or 2, characterized in that: The shape of the outer working surface of the split expander (8) is matched with the shape of the inner surface of the to-be-formed barrel blank (5).

8. A method of necking spinning a dumpy using the self-expanding self-centering internal support device for necking spinning of a dumpy according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: S1. Clamping and positioning; Clamp the force transmission cylinder (3) on the spinning machine chuck (18), and sleeve the barrel blank (5) outside the split expander (8), and pass the positioning mandrel (4) through each component and tighten it by the spinning machine tail top (21); S2. Expanding and centering; Rotate the outer adjusting cylinder (15), drive the inner adjusting cylinder (14) and the hexagonal expander core (11) to move axially, and make all the split expanders (8) expand radially synchronously through the action of the inclined wedge surfaces, until they are completely fitted with the inner wall of the barrel blank (5) and are expanded tightly; S3. Spinning forming; Start the spinning machine, the main shaft drives the tooling and the barrel blank (5) to rotate, the first spinning wheel (19) and the second spinning wheel (22) respectively neck spinning the two ends of the barrel blank (5), forming a barrel (20); S4. Unloading; Reverse rotate the outer adjusting cylinder (15), drive the split expanders (8) to contract radially synchronously to separate from the inner wall of the workpiece and the size is smaller than the minimum inner diameter of the barrel (20), and then pull out the tooling.

9. The method of necking spinning of a waisted drum according to claim 8, wherein: In step S2, the expansion is achieved by rotating the outer adjusting cylinder (15), which is operated in the state of the spinning machine tail top (21) being tightened.

10. The method of necking spinning of a waisted drum according to claim 8 or 9, wherein: In step S3, the transmission path of the spinning torque is: the spinning machine chuck (18), the force transmission cylinder (3), the first T-shaped strip (7), the split expansion die (8) to the cylinder blank (5).

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