Dense bead expansion mandrel and use method thereof

Abstract

The invention discloses a dense bead expansion mandrel and a using method thereof, and relates to the technical field of precision machining.The dense bead expansion mandrel comprises a tailstock assembly, a guide shaft seat and a mandrel assembly, and the tailstock assembly comprises a spring tailstock, a tail guide ring, a first spacer bush, a rectangular spring and a center shaft; the center shaft sequentially penetrates through the rectangular spring and the first spacer bush to be connected to the tail guide ring. The center shaft is sleeved with the guide shaft seat, and one end of the guide shaft seat is suitable for being inserted into the end face of the spring tailstock; the mandrel assembly comprises an open spring jacket and an inner tensioning component; a plurality of winding limiting sleeves are suitable for axially limiting the periphery of the open spring clamping sleeve, the end, away from the inner tensioning component, of the tail guide ring is suitable for sliding in the spring tailstock to one side of the inner tensioning component, and then the inner tensioning component is pushed to conduct tensioning on the open spring clamping sleeve in the radial direction. According to the dense bead expansion mandrel, multi-point simultaneous tensioning adjustment can be achieved when the axial size of the mandrel inner hole is inconsistent, and the positioning precision of a winding limiting sleeve is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of coil manufacturing, and in particular to a dense bead expansion mandrel and a use method thereof. Background Art

[0002] Mechanical expansion mandrels and hydraulic expansion mandrels are commonly used connectors in the processing of gears, gear shaping cutters, gear shaving cutters, hobs, etc. The mechanical expansion mandrel has a large expansion volume, but its positioning accuracy is low and it is difficult to ensure the processing accuracy; the hydraulic expansion mandrel has a small expansion volume and is expensive, but its positioning accuracy is high.

[0003] At present, the coil winding processing using a winding limit sleeve needs to be completed through multiple processes in sequence. When the traditional surface contact using a traditional mechanical expansion mandrel and a hydraulic expansion mandrel is tightened, the cylindricity of the inner hole of the mandrel changes, so that the surface contact will become a point contact, thereby affecting the positioning accuracy of the winding limit sleeve. Since the processing accuracy requirements for coil winding are extremely high, any slight deviation will lead to coil winding failure or rework.

[0004] In addition, if a mechanical expansion mandrel with a large expansion amount is used to clamp the winding limit sleeve, it often cannot directly meet the processing accuracy requirements due to its low positioning accuracy; if a hydraulic expansion mandrel is used to clamp the winding limit sleeve, its maximum expansion amount is generally only tens of microns. In order to improve the positioning accuracy, multiple mandrels are required to complete the processing, which increases the processing cost of the winding limit sleeve. Summary of the invention

[0005] In view of this, in order to solve the defects existing in the above-mentioned technology, the present invention provides a dense bead expansion mandrel and a method for using the same.

[0006] The first object of the present invention is to provide a dense bead expansion mandrel, the dense bead expansion mandrel comprising:

[0007] A tailstock assembly, the tailstock assembly comprising a spring tailstock, a tail guide ring slidably arranged in the spring tailstock, a first spacer and a rectangular spring, and a central shaft with one end inserted into the spring tailstock, the central shaft sequentially passing through the rectangular spring and the first spacer and connected to the tail guide ring;

[0008] A guide shaft seat, sleeved on the central shaft, one end of which is suitable for being plugged into the end surface of the spring tail seat;

[0009] A core shaft assembly, comprising an open spring jacket adapted to be inserted into the other end of the guide shaft seat and an inner tensioning component slidably disposed inside the open spring jacket, wherein the inner tensioning component is sleeved on the central shaft and adapted to abut against the inner wall of the guide shaft seat;

[0010] A plurality of winding limit sleeves are arranged on the outer periphery of the open spring jacket for axial limitation, and the end of the tail guide ring away from the inner tensioning component is suitable for sliding toward one side of the inner tensioning component in the spring tail seat under the push of the locking and fixing assembly, thereby pushing the inner tensioning component to tighten the open spring jacket in the radial direction.

[0011] Optionally, a first guide hole, a second guide hole and a third guide hole are coaxially connected in sequence at the center of the spring tail seat, and the diameter of the second guide hole is larger than the diameters of the first guide hole and the third guide hole;

[0012] The tail guide ring includes a first guide ring shaft segment, a first disc segment and a second guide ring shaft segment which are coaxially connected in sequence, the first guide ring shaft segment is suitable for being inserted into the third guide hole, the first disc segment is suitable for sliding in the second guide hole, and the second guide ring shaft segment is suitable for being threadedly connected in the first center threaded hole of the center shaft.

[0013] Optionally, the first spacer is suitable for being sleeved on one end of the central shaft close to the tail guide ring, and the first spacer is suitable for sliding in the second guide hole.

[0014] Optionally, the guide shaft seat comprises a first guide shaft segment and a second guide shaft segment that are coaxially connected, a first central hole is provided through the center of the first guide shaft segment, and a second central hole is provided through the center of the second guide shaft segment;

[0015] The guide shaft seat is sleeved on the center shaft through the first center hole and the second center hole, and the second guide shaft segment is suitable for being inserted into the first guide hole so that one end of the rectangular spring abuts against the first spacer sleeve and the other end abuts against the end face of the second guide shaft segment.

[0016] Optionally, a first inner stop is provided at the center of a side of the first guide shaft segment away from the second guide shaft segment;

[0017] A first outer stop is provided at the center of one end of the open spring clip, and the first outer stop is suitable for being sleeved on the central axis and inserted into the first guide hole.

[0018] Optionally, the open spring sleeve includes a first flange section and a square cylinder that are coaxially and integrally connected, the first outer stop is located at the end of the first flange section away from the square cylinder, and the centers of the first flange section, the square cylinder and the first outer stop are provided with a second circular hole, a first conical hole and a first circular hole that are coaxially connected in sequence, and the diameter of the first conical hole close to the first circular hole is larger than the diameter close to the second circular hole.

[0019] Optionally, the central shaft comprises a first shaft segment and a second shaft segment which are coaxially connected, the diameter of the first shaft segment is larger than the diameter of the second shaft segment, and one end of the first shaft segment away from the second shaft segment is suitable for being threadedly connected to the second guide ring shaft segment;

[0020] The internal tensioning component includes a second spacer sleeve and a ball sleeve structure suitable for being sleeved on the first shaft segment and a head limit sleeve suitable for being threadedly connected to the second shaft segment, one end of the second spacer sleeve is suitable for being inserted into the first center hole, and the other end is suitable for abutting against the end face of the ball sleeve structure through the second circular hole, the first conical hole and the first circular hole.

[0021] Optionally, the ball sleeve structure includes multiple rows of ball rings and ball limit blocks sleeved on the first shaft segment, the ball limit blocks are supported on both sides of each ball ring, and the outer diameter of the ball ring is supported on the inner wall of the square cylinder.

[0022] Optionally, a circular hole close to the first flange section and a first through groove extending along the central axis of the open spring jacket are provided at the center of each end face of the square cylinder, one end of the first through groove extends to communicate with the circular hole on the end face, and the other end extends to the end of the square cylinder.

[0023] The second object of the present invention is to provide a method for using the above-mentioned dense bead expansion mandrel, the method comprising the steps of:

[0024] A winding limit sleeve and a ball sleeve structure are respectively installed on the inner and outer sides of the open spring jacket;

[0025] By pressurizing the locking and fixing assembly, the locking and fixing assembly drives the tailstock assembly to move, and then drives the ball sleeve structure to adjust the tension of the winding limit sleeve in the radial direction, so that the expansion amount of the square cylinder reaches 60% to 80% of the pre-expansion amount;

[0026] After the square cylinder is adjusted to the pre-expansion amount, the radial runout of the square cylinder relative to the central axis at the cross section of the winding limit sleeve is measured;

[0027] After tightening the locking and fixing assembly, the expansion amount of the square cylinder reaches the pre-expansion amount. The pre-expansion amount of the square cylinder should be able to cause a slight interference of 1 to 3 μm on one side after the winding limit sleeve is installed.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects:

[0029] 1. The dense bead expansion mandrel in the present invention is composed of a tailstock assembly, a guide shaft seat and a mandrel assembly. The tailstock assembly is composed of a spring tailstock, a tail guide ring, a first spacer, a rectangular spring and a central shaft. The spring tailstock, the tail guide ring, the first spacer, the rectangular spring and the central shaft together constitute a retractable tailstock for supporting and fixing the mandrel assembly, wherein the tail guide ring, the first spacer and the rectangular spring are slidably arranged in the spring tailstock, one end of the central shaft is plugged into the interior of the spring tailstock, the central shaft passes through the rectangular spring and the first spacer in turn and is connected to the tail guide ring, and the elastic force is provided by the rectangular spring so that the tail guide ring and the first spacer can slide in the spring tailstock. The central shaft serves as the central support of the entire structure and is used to connect the tailstock assembly and the mandrel assembly. The guide shaft seat sleeve is arranged on the central shaft, and one end of the guide shaft seat is suitable for plugging into the end face of the spring tailstock to provide guidance for the mandrel assembly. The core shaft assembly is composed of an open spring jacket and an inner tensioning component. The open spring jacket is suitable for being plugged into the other end of the guide shaft seat. The inner tensioning component is slidably arranged inside the open spring jacket. The inner tensioning component is sleeved on the central shaft and is suitable for abutting against the inner wall of the guide shaft seat. The open spring jacket realizes the tensioning of the winding limit sleeve through the tensioning action of the inner tensioning component. A plurality of winding limit sleeves are arranged on the outer periphery of the open spring jacket for axial limitation. The end of the tail guide ring away from the inner tensioning component is suitable for sliding toward one side of the inner tensioning component in the spring tail seat under the push of the locking and fixing component, thereby pushing the inner tensioning component to tighten the open spring jacket in the radial direction. The inner tensioning component tightens the open spring jacket in the radial direction to adapt to winding limit sleeves of different diameters. When it is necessary to tighten the winding limit sleeve, the locking and fixing assembly is used to push the tail guide ring to slide to one side of the inner tensioning component, which in turn pushes the inner tensioning component to tighten the open spring sleeve in the radial direction, thereby fixing the winding limit sleeve; when it is necessary to release the winding limit sleeve, the locking and fixing assembly can be released to make the inner tensioning component retract, and the open spring sleeve is relaxed accordingly, thereby releasing the winding limit sleeve.

[0030] 2. Through the setting of the spring tail seat and the rectangular spring, a stable supporting force can be provided to ensure the stability of the mandrel assembly during operation; through the internal tensioning component, it can be tightened in the radial direction, allowing the mandrel assembly to adapt to winding limit sleeves of different diameters.

[0031] 3. Compared with the tapered surface contact of the traditional expansion mandrel, the ball sleeve structure reduces the contact area and does not require too high a shape tolerance; a circle of balls in the ball ring can achieve self-centering, and does not require too high a position tolerance in tooling.

[0032] 4. When the traditional expansion mandrel is tightened by surface contact, the surface contact will become point contact due to the change in the cylindricality of the inner hole; while this dense bead expansion mandrel can achieve uniform tightening at multiple points at the same time when the axial dimensions of the inner hole of the mandrel are inconsistent.

[0033] 5. The dense bead expansion mandrel is pushed by the mandrel to control the deformation of the positioning shaft section to ensure that the inner hole is tightened in different shaft sections, avoiding the risk of loosening of multiple workstations during the same action process, and significantly improving the reliability of the winding positioning tooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the structure of a dense bead expansion mandrel in one direction in an embodiment of the present invention;

[0035] Figure 2 It is a schematic diagram of the structure of the dense bead expansion mandrel in another direction in an embodiment of the present invention;

[0036] Figure 3 It is a schematic cross-sectional structure diagram of a dense bead expansion mandrel in an embodiment of the present invention;

[0037] Figure 4 It is a schematic diagram of the internal cross-sectional structure of the tailstock assembly in an embodiment of the present invention;

[0038] Figure 5 Schematic diagram of the three-dimensional structure of the spring tailstock in an embodiment of the present invention;

[0039] Figure 6 It is a schematic cross-sectional structural diagram of a spring tailstock in an embodiment of the present invention;

[0040] Figure 7 Schematic diagram of the three-dimensional structure of the tail guide ring in an embodiment of the present invention;

[0041] Figure 8 It is a schematic cross-sectional structural diagram of a guide shaft seat in an embodiment of the present invention;

[0042] Fig. 9 It is a schematic diagram of the assembly structure of the mandrel assembly and the central shaft in an embodiment of the present invention;

[0043] Fig.10 A schematic diagram of the structure of an open spring jacket in one direction in an embodiment of the present invention;

[0044] Fig.11 It is a schematic diagram of the structure of the open spring jacket in another direction in an embodiment of the present invention;

[0045] Fig.12 It is a schematic diagram of the internal cross-sectional structure of the open spring jacket in an embodiment of the present invention;

[0046] Fig.13 It is a schematic diagram of the three-dimensional structure of the winding limit sleeve in an embodiment of the present invention.

[0047] Description of reference numerals:

[0048] 1-tailstock assembly; 11-spring tailstock; 111-first guide hole; 112-second guide hole; 113-third guide hole; 12-tail guide ring; 121-first guide ring shaft section; 122-first disc section; 123-second guide ring shaft section; 1231-first threaded section; 13-first spacer; 14-rectangular spring; 15-center axis; 151-first shaft section; 1511-first center threaded hole; 152-second shaft section;

[0049] 2-guide shaft seat;

[0050] 21-first guide shaft section; 211-first center hole; 2111-first inner stop; 22-second guide shaft section; 221-second center hole;

[0051] 3- spindle assembly;

[0052] 31-open spring jacket; 311-first flange section; 3111-first circular hole; 3112-giving groove; 3113-connecting hole; 312-square cylinder; 3121-second circular hole; 3122-first conical hole; 3123-end circular hole; 3124-first through groove; 313-first outer stop;

[0053] 32-internal tensioning component; 321-second spacer; 322-ball bearing sleeve structure; 3221-ball ring; 3222-ball limiting block; 323-head limiting sleeve;

[0054] 4-winding limit sleeve; 41-ring spacer sleeve. DETAILED DESCRIPTION

[0055] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] In the description of the present invention, it should be noted that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0057] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] Figure 1-13 The present invention shows a dense bead expansion mandrel provided by an embodiment of the present invention, wherein the dense bead expansion mandrel comprises a tailstock assembly 1, a guide shaft seat 2 and a mandrel assembly 3, wherein:

[0059] The tailstock assembly 1 comprises a spring tailstock 11, a tail guide ring 12, a first spacer 13, a rectangular spring 14 and a central shaft 15, which together constitute a retractable tailstock for supporting and fixing the spindle assembly 3, wherein:

[0060] The tail guide ring 12, the first spacer sleeve 13 and the rectangular spring 14 are slidably arranged in the spring tail seat 11, one end of the central shaft 15 is inserted into the interior of the spring tail seat 11, and the central shaft 15 passes through the rectangular spring 14 and the first spacer sleeve 13 in turn and is connected to the tail guide ring 12. The elastic force provided by the rectangular spring 14 allows the tail guide ring 12 and the first spacer sleeve 13 to slide in the spring tail seat 11.

[0061] The center shaft 15 serves as the center support of the entire structure and is used to connect the tailstock assembly 1 and the spindle assembly 3. The guide shaft seat 2 is sleeved on the center shaft 15. One end of the guide shaft seat 2 is suitable for being inserted into the end face of the spring tailstock 11 to provide guidance for the spindle assembly 3.

[0062] The core shaft assembly 3 includes an open spring sleeve 31 and an internal tensioning component 32. The open spring sleeve 31 is suitable for being plugged into the other end of the guide shaft seat 2. The internal tensioning component 32 is slidably arranged inside the open spring sleeve 31. The internal tensioning component 32 is sleeved on the central shaft 15 and is suitable for abutting against the inner wall of the guide shaft seat 2. The open spring sleeve 31 realizes the tensioning of the winding limit sleeve 4 through the tensioning effect of the internal tensioning component 32.

[0063] A plurality of winding limiting sleeves 4 are provided on the outer periphery of the open spring jacket 31 for axial limiting, and one end of the tail guide ring 12 away from the inner tensioning component 32 is adapted to slide toward one side of the inner tensioning component 32 in the spring tail seat 11 under the push of the locking and fixing assembly, thereby pushing the inner tensioning component 32 to tighten the open spring jacket 31 in the radial direction. The inner tensioning component 32 tightens the open spring jacket 31 in the radial direction to adapt to pipes of different diameters.

[0064] When it is necessary to tighten the winding limit sleeve 4, the tail guide ring 12 is pushed to slide toward one side of the inner tightening component 32 through the locking and fixing assembly, which will then push the inner tightening component 32 to tighten the open spring sleeve 31 in the radial direction, thereby fixing the winding limit sleeve 4; when it is necessary to release the winding limit sleeve 4, the locking and fixing assembly can be released to make the inner tightening component 32 retract, and the open spring sleeve 31 is relaxed accordingly, thereby releasing the winding limit sleeve 4.

[0065] Therefore, by setting the spring tail seat 11 and the rectangular spring 14, a stable supporting force can be provided to ensure the stability of the core shaft assembly 3 during operation; the internal tensioning component 32 can be tightened in the radial direction, allowing the core shaft assembly 3 to adapt to winding limit sleeves 4 of different diameters.

[0066] For further information, see Figure 1 As shown, the center of the spring tail seat 11 is provided with a first guide hole 111, a second guide hole 112 and a third guide hole 113 which are coaxially connected in sequence, and the diameter of the second guide hole 112 is larger than the diameters of the first guide hole 111 and the third guide hole 113. The first guide hole 111, the second guide hole 112 and the third guide hole 113 constitute the guide and sliding path of the central shaft 15 and the tail guide ring 12, and the first disc segment 122 slides freely in the second guide hole 112, so that the moving range of the first guide ring shaft segment 121 and the second guide ring shaft segment 123 can be limited.

[0067] The tail guide ring 12 comprises a first guide ring shaft segment 121, a first disc segment 122 and a second guide ring shaft segment 123 which are coaxially connected in sequence. The first guide ring shaft segment 121 is suitable for being inserted into the third guide hole 113, the first disc segment 122 is suitable for sliding in the second guide hole 112, and the second guide ring shaft segment 123 is suitable for being threadedly connected in the first central threaded hole 1511 of the central shaft 15. In this way, by sliding the first disc segment 122 in the second guide hole 112, the position of the tail guide ring 12 can be precisely controlled; the tail guide ring 12 can be guided and slid in the spring tail seat 11 to limit the freedom of movement of the tail guide ring 12 in the radial direction, which can not only ensure the stability of the tail guide ring 12 in the spring tail seat 11, but also prevent unnecessary shaking or displacement.

[0068] In actual operation, by rotating the locking and fixing assembly, the tail guide ring 12 can be driven to move along the thread, thereby adjusting the position of the inner tensioning component 32 to achieve the tightening or loosening of the open spring jacket 31 .

[0069] For further information, see Figure 4 As shown, the first spacer sleeve 13 is suitable for being sleeved on one end of the central shaft 15 close to the tail guide ring 12 , and the first spacer sleeve 13 is suitable for sliding in the second guide hole 112 .

[0070] In this embodiment, the first spacer sleeve 13 is used to be sleeved on one end of the center shaft 15 close to the tail guide ring 12, and the first spacer sleeve 13 is suitable for sliding in the second guide hole 112, so that the first spacer sleeve 13 can realize stable sliding of the tail guide ring 12 and the center shaft 15 after being connected, and can also allow the center shaft 15 to move or adjust its position within a certain range to adapt to different working conditions or requirements.

[0071] For further information, see Figure 3 , 8 As shown, the guide shaft seat 2 includes a first guide shaft segment 21 and a second guide shaft segment 22 that are coaxially connected. A first center hole 211 is formed in the center of the first guide shaft segment 21, and a second center hole 221 is formed in the center of the second guide shaft segment.

[0072] The guide shaft seat 2 is sleeved on the central shaft 15 through the first central hole 211 and the second central hole 221, and the second guide shaft segment 22 is suitable for being inserted in the first guide hole 111, so that one end of the rectangular spring 14 abuts on the first spacer 13, and the other end abuts on the end surface of the second guide shaft segment 22, so that the rectangular spring 14 can provide elastic support for sliding, allowing a certain axial and radial displacement while maintaining the compactness of the structure. In addition, the rectangular spring 14 is also used to provide elastic buffering, which can absorb the impact and vibration that may occur during operation and protect the system from damage.

[0073] Specifically in this embodiment, the guide shaft seat 2 is sleeved on the central shaft 15 through the first center hole 211 and the second center hole 221, so that the guide shaft seat 2 slides relative to the central shaft 15 while maintaining coaxiality; the second guide shaft segment 22 is inserted into the first guide hole 111 to ensure the connection and positioning of the guide shaft seat 2 and the spring tail seat 11.

[0074] In actual operation, the guide shaft seat 2 is used to connect the spring tail seat 11 and the open spring jacket 31, so that the mandrel assembly 3 can be flexibly adjusted to meet different operating requirements. At the same time, the elastic effect of the rectangular spring 14 can ensure that when the mandrel assembly 3 is tightened or relaxed, the system can respond smoothly, reducing the risk of damage caused by sudden loading or unloading.

[0075] For further information, see Figure 3 , 8 As shown in Figures 1 and 12, a first inner stop 2111 is provided at the center of one side of the first guide shaft section 21 away from the second guide shaft section 22. The first inner stop 2111 helps maintain the stability of the guide shaft seat 2 and prevents unnecessary displacement or rotation during operation. A first outer stop 313 is provided at the center of one end of the open spring jacket 31. The first outer stop 313 is suitable for being sleeved on the central shaft 15 and plugged into the first guide hole 111. This allows the open spring jacket 31 to accurately control its position on the central shaft 15, which is crucial for achieving accurate tightening and loosening operations.

[0076] For further information, see Fig.10 , 11 As shown in Figures 12, the open spring jacket 31 includes a first flange section 311 and a square cylinder 312 which are coaxially and integrally connected. The first outer stop 313 is located at the end of the first flange section 311 away from the square cylinder 312. The centers of the first flange section 311, the square cylinder 312 and the first outer stop 313 are provided with a second circular hole 3121, a first conical hole 3122 and a first circular hole 3111 which are coaxially connected in sequence, and the diameter of the first conical hole 3122 near the first circular hole 3111 is larger than the diameter near the second circular hole 3121.

[0077] Specifically in this embodiment, a plurality of evenly distributed paving grooves 3112 are provided on the outer edge of the first flange section 311, and a connecting hole 3113 is provided on the paving groove 3112. The first flange section 311 can be connected to the first guide shaft section 21 by connecting bolts with threads in the connecting hole 3113; the first outer stop 313 is used to ensure the accurate positioning of the open spring jacket 31 on the central axis 15; the first tapered hole 3122 is used for the inner tensioning component 32 to slide smoothly during tensioning and relaxation, thereby reducing resistance and wear during operation; the coaxial integral connection between the first flange section 311 and the square cylinder 312 can not only provide sufficient structural strength, but also withstand other forces during operation; the inner tensioning component 32 realizes radial tensioning of the open spring jacket 31 through the tensioning effect of the first tapered hole 3122 to adapt to winding limit sleeves 4 of different diameters; in addition, the progressive setting of the first tapered hole 3122 not only helps to smoothly transmit the tensioning force, but also reduces damage to the open spring jacket 31.

[0078] For further information, see Fig. 9As shown, in order to ensure the efficiency and accuracy of force transmission and to facilitate installation and maintenance, the central shaft 15 in this embodiment includes a first shaft segment 151 and a second shaft segment 152 that are coaxially connected. The diameter of the first shaft segment 151 is larger than the diameter of the second shaft segment 152. The end of the first shaft segment 151 away from the second shaft segment 152 is suitable for being threadedly connected to the second guide ring shaft segment 1231. This arrangement enables the first shaft segment 151 to withstand greater torque and load, while the second shaft segment 152 can be designed to be more sophisticated to meet different connection requirements.

[0079] like Figure 3 , 9 As shown, the inner tensioning component 32 includes a second spacer sleeve 321, a ball sleeve structure 322 and a head stop sleeve 323, wherein the second spacer sleeve 321 and the ball sleeve structure 322 are suitable for sleeve-mounting on the first shaft segment 151, the head stop sleeve 323 is suitable for threading on the second shaft segment 152, one end of the second spacer sleeve 321 is suitable for being inserted into the first center hole 211, and the other end is suitable for abutting against the end face of the ball sleeve structure 322 through the second circular hole 3121, the first tapered hole 3122 and the first circular hole 3111. The inner tensioning component 32 is composed of these three parts, wherein the second spacer sleeve 321 and the ball sleeve structure 322 are suitable for sleeve-mounting on the first shaft segment 151, and the head stop sleeve 323 is suitable for threading on the second shaft segment 152.

[0080] For further information, see Fig. 9 As shown, the ball sleeve structure 322 includes multiple rows of ball rings 3221 and ball limit blocks 3222, which are sleeved on the first shaft section 151, and the ball limit blocks 3222 are supported on both sides of each ball ring 3221, and the outer diameter of the ball ring 3221 is supported on the inner wall of the square cylinder 312.

[0081] Specifically in this embodiment, the ball sleeve structure 322 is composed of multiple rows of ball rings 3221 and ball limit blocks 3222. These components are mounted on the first shaft segment 151, and the ball limit blocks 3222 are supported on both sides of each ball ring 3221, which not only allows the ball rings 3221 to roll between the ball limit blocks 3222, but also reduces friction and improves the flexibility and durability of the sleeve.

[0082] The outer diameter of the ball ring 3221 is supported on the inner wall of the square cylinder 312. This support method provides a stable external support for the ball sleeve structure, ensuring the stability and reliability of the structure.

[0083] Therefore, the ball sleeve structure 322 achieves lubrication on a certain contact surface through the mutual movement between the ball, inner and outer circles. This lubrication method is called point lubrication, and utilizes the balls to roll between the inner and outer circles to withstand axial and radial loads, greatly reducing the friction coefficient and improving the uniformity of the radial tension of the inner hole of the core shaft.

[0084] The main function of the ball sleeve structure 322 is not only to reduce friction and improve positioning accuracy, but also to achieve high-precision repeated positioning through the cooperation of the ball ring 3221 and the ball limit block 3222.

[0085] In addition, the ball sleeve structure 322 also has the ability of automatic adjustment, and can remain stable when subjected to large radial loads, thereby reducing wear and failure rate.

[0086] Therefore, the design of the ball sleeve structure 322 significantly improves the stability, flexibility and durability of the entire dense bead expansion mandrel system by reducing friction, improving positioning accuracy and structural stability. The application of this precise and repeated positioning structure not only improves work efficiency, but also reduces production costs.

[0087] For further information, see Fig.10 , 11 As shown, a circular hole 3123 close to the first flange section 311 and a first through slot 3124 extending along the central axis of the open spring jacket are provided at the center of each end face of the square cylinder 312. One end of the first through slot 3124 extends to communicate with the circular hole 3123, and the other end extends to the end of the square cylinder 312.

[0088] Specifically, the square cylinder 312 allows the inner tensioning component 32 to move precisely therein, thereby realizing precise tightening and loosening operations on the open spring jacket 31. The circumference of the square cylinder 312 is evenly distributed with a number of open grooves, and when the locking outer cone presses the inner cone, the expansion sleeve is deformed, and the inner expansion sleeve diameter of the square cylinder 312 becomes larger to tighten the winding limit sleeve 4.

[0089] In actual operation, the inner tensioning member 32 moves inside the square cylinder 312 through the first through slot 3124 to tighten or loosen the open spring jacket 31. The end face circular hole 3123 provides a fixed connection point, while the first through slot 3124 provides a sliding path, so that the inner tensioning member 32 can move smoothly to achieve precise tightening and loosening operations.

[0090] The embodiment of the present invention further provides a method for using the above-mentioned dense bead expansion mandrel, the method comprising the steps of:

[0091] The winding limit sleeve 4 and the ball sleeve structure 322 are respectively installed on the inner and outer sides of the open spring jacket 31;

[0092] By pressurizing the locking and fixing assembly, the locking and fixing assembly drives the tailstock assembly 1 to move, and then drives the ball sleeve structure 322 to adjust the tension of the winding limit sleeve 4 in the radial direction, so that the expansion amount of the square cylinder 312 reaches 60% to 80% of the pre-expansion amount;

[0093] After the square cylinder 312 is adjusted to the pre-expansion amount, the radial runout of the square cylinder 312 relative to the central axis 15 at the cross section of the winding limit sleeve 4 is measured;

[0094] After tightening the locking and fixing assembly, the expansion amount of the square cylinder 312 reaches the pre-expansion amount. The pre-expansion amount of the square cylinder 312 should be able to make a slight interference of 1 to 3 μm on one side of the winding limit sleeve 4 after installation.

[0095] Therefore, by using a dense bead expansion mandrel and accurately controlling the tension and pre-expansion, high-precision clamping of the winding limit sleeve 4 is achieved, which not only improves the positioning processing accuracy of the winding limit sleeve 4, realizes gap-free clamping of the mandrel and the inner hole, but also improves processing accuracy and efficiency.

[0096] It should be noted that the working principle of the dense bead expansion mandrel is mainly based on the principle of radial expansion, and combines pneumatic or hydraulic technology to achieve stable clamping of the winding limit sleeve 4. This expansion deformation allows the mandrel to achieve the function of connection or force transmission when subjected to a certain external force or pressure.

[0097] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A dense bead expansion mandrel, characterized in that: include: A tailstock assembly, the tailstock assembly comprising a spring tailstock, a tail guide ring slidably arranged in the spring tailstock, a first spacer and a rectangular spring, and a central shaft with one end inserted into the spring tailstock, the central shaft sequentially passing through the rectangular spring and the first spacer and connected to the tail guide ring; A guide shaft seat, sleeved on the central shaft, one end of which is suitable for being plugged into the end surface of the spring tail seat; A core shaft assembly, comprising an open spring jacket adapted to be inserted into the other end of the guide shaft seat and an inner tensioning component slidably disposed inside the open spring jacket, wherein the inner tensioning component is sleeved on the central shaft and adapted to abut against the inner wall of the guide shaft seat; A plurality of winding limit sleeves are arranged on the outer periphery of the open spring jacket for axial limitation, and the end of the tail guide ring away from the inner tensioning component is suitable for sliding toward one side of the inner tensioning component in the spring tail seat under the push of the locking and fixing assembly, thereby pushing the inner tensioning component to tighten the open spring jacket in the radial direction.

2. The dense bead expansion mandrel according to claim 1, characterized in that: The center of the spring tailstock is provided with a first guide hole, a second guide hole and a third guide hole which are coaxially connected in sequence, and the diameter of the second guide hole is larger than the diameters of the first guide hole and the third guide hole; The tail guide ring includes a first guide ring shaft segment, a first disc segment and a second guide ring shaft segment which are coaxially connected in sequence, the first guide ring shaft segment is suitable for being inserted into the third guide hole, the first disc segment is suitable for sliding in the second guide hole, and the second guide ring shaft segment is suitable for being threadedly connected in the first center threaded hole of the center shaft.

3. The dense bead expansion mandrel according to claim 2, characterized in that: The first spacer is suitable for being sleeved on one end of the central shaft close to the tail guide ring, and the first spacer is suitable for sliding in the second guide hole.

4. The dense bead expansion mandrel according to claim 2, characterized in that: The guide shaft seat comprises a first guide shaft section and a second guide shaft section which are coaxially connected, a first central hole is provided through the center of the first guide shaft section, and a second central hole is provided through the center of the second guide shaft section; The guide shaft seat is sleeved on the center shaft through the first center hole and the second center hole, and the second guide shaft segment is suitable for being inserted into the first guide hole so that one end of the rectangular spring abuts against the first spacer sleeve and the other end abuts against the end face of the second guide shaft segment.

5. The dense bead expansion mandrel according to claim 4, characterized in that: A first inner stop is provided at the center of one side of the first guide shaft section away from the second guide shaft section; A first outer stop is provided at the center of one end of the open spring clip, and the first outer stop is suitable for being sleeved on the central axis and inserted into the first guide hole.

6. The dense bead expansion mandrel according to claim 5, characterized in that: The open spring clip includes a first flange section and a square cylinder that are coaxially and integrally connected. The first outer stop is located at the end of the first flange section away from the square cylinder. The centers of the first flange section, the square cylinder and the first outer stop are provided with a second circular hole, a first conical hole and a first circular hole that are coaxially connected in sequence, and the diameter of the first conical hole close to the first circular hole is larger than the diameter close to the second circular hole.

7. The dense bead expansion mandrel according to claim 6, characterized in that: The central shaft comprises a first shaft segment and a second shaft segment which are coaxially connected, the diameter of the first shaft segment is larger than the diameter of the second shaft segment, and one end of the first shaft segment away from the second shaft segment is suitable for being threadedly connected to the second guide ring shaft segment; The internal tensioning component includes a second spacer sleeve and a ball sleeve structure suitable for being sleeved on the first shaft segment and a head limit sleeve suitable for being threadedly connected to the second shaft segment, one end of the second spacer sleeve is suitable for being inserted into the first center hole, and the other end is suitable for abutting against the end face of the ball sleeve structure through the second circular hole, the first conical hole and the first circular hole.

8. The dense bead expansion mandrel according to claim 7, characterized in that: The ball sleeve structure includes multiple rows of ball rings and ball limit blocks sleeved on the first shaft segment. The ball limit blocks are supported on both sides of each ball ring, and the outer diameter of the ball ring is supported on the inner wall of the square cylinder.

9. The dense bead expansion mandrel according to claim 6, characterized in that: A circular hole close to the first flange section and a first through slot extending along the central axis of the open spring jacket are provided at the center of each end face of the square cylinder. One end of the first through slot extends to communicate with the circular hole on the end face, and the other end extends to the end of the square cylinder.

10. A method for using the dense bead expansion mandrel according to any one of claims 1 to 9, characterized in that: The method of use comprises the steps of: A winding limit sleeve and a ball sleeve structure are respectively installed on the inner and outer sides of the open spring jacket; By pressurizing the locking and fixing assembly, the locking and fixing assembly drives the tailstock assembly to move, and then drives the ball sleeve structure to adjust the tension of the winding limit sleeve in the radial direction, so that the expansion amount of the square cylinder reaches 60% to 80% of the pre-expansion amount; After the square cylinder is adjusted to the pre-expansion amount, the radial runout of the square cylinder relative to the central axis at the cross section of the winding limit sleeve is measured; After tightening the locking and fixing assembly, the expansion amount of the square cylinder reaches the pre-expansion amount. The pre-expansion amount of the square cylinder should be able to cause a slight interference of 1 to 3 μm on one side after the winding limit sleeve is installed.

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