Simple NiTi shape memory spring winding device and heat setting method

Abstract

The application relates to a simple NiTi shape memory spring winding device and a heat setting method, which comprises a fixed bottom plate provided with a connecting piece for being connected with a universal material testing machine at one end, a setting column is vertically arranged on the fixed bottom plate, a thread groove facilitating spiral winding of a NiTi memory alloy wire is arranged on the outer circumferential side of the setting column, and the thread groove extends along the axial direction of the setting column; a bottom fixing assembly for fixing the lower end of the NiTi memory alloy wire spirally wound on the setting column is arranged on the side of the setting column close to the connecting piece, and a top fixing assembly for fixing the upper end of the NiTi memory alloy wire spirally wound on the setting column is arranged on the side of the setting column far from the connecting piece. The application has the advantages of simple and reasonable design, small equipment volume, simple operation, great simplification of the preparation process under the premise of guaranteeing the size precision of the NiTi shape memory spring, great improvement of the laboratory efficiency, and high application value.

Description

TECHNICAL FIELD

[0002] The present application relates to a simple NiTi shape memory spring winding device and heat setting method. BACKGROUND

[0004] Shape memory alloy spring can be used as driving, buffering, damping, energy storage and other functional structural elements, and has wide application prospect. However, the existing spring winding equipment is expensive and occupies large area, which is not suitable for small-scale laboratory application. Moreover, the NiTi spring without heat setting will restore flat when heated to Af, and there is no special winding and heat setting method for NiTi shape memory alloy spring at present. Therefore, it is necessary to improve the above technical problems, and the present application is thus born. SUMMARY

[0006] The present application improves the existing problems, that is, the technical problem to be solved by the present application is to provide a simple NiTi shape memory spring winding device and heat setting method.

[0007] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: a simple NiTi shape memory spring winding device, comprising a fixed bottom plate provided with a connecting piece at one end for connecting with a universal material testing machine, a shaping column is vertically arranged on the fixed bottom plate, a thread groove for facilitating the spiral winding of NiTi memory alloy wire is arranged on the outer circumferential side of the shaping column, and the thread groove extends along the axial direction of the shaping column; a bottom fixing assembly for fixing the lower end of the NiTi memory alloy wire spirally wound on the shaping column is arranged on the side of the shaping column close to the connecting piece, and a top fixing assembly for fixing the upper end of the NiTi memory alloy wire spirally wound on the shaping column is arranged on the side of the shaping column away from the connecting piece.

[0008] Further, the shaping column is screwed with the fixed bottom plate; the bottom fixing assembly comprises a bottom fixing shaft which is vertically arranged and screwed with the fixed bottom plate, an annular bottom fixing flange is arranged on the middle part of the bottom fixing shaft, and a bottom gland for pressing the lower end of the NiTi memory alloy wire on the top surface of the bottom fixing flange is screwed on the upper end of the bottom fixing shaft; the top fixing assembly comprises a top fixing shaft which is vertically arranged and screwed with the fixed bottom plate, an annular top fixing flange is arranged on the outer circumferential side of the top fixing shaft, and a top gland for pressing the upper end of the NiTi memory alloy wire on the top surface of the top fixing flange is screwed on the upper end of the top fixing shaft.

[0009] Further, the fixing base plate is provided with connecting screw holes corresponding to the positions of the shaping column, the bottom fixing shaft and the top fixing shaft, the bottom surface of the shaping column is provided with a downward protruding connecting thread section, the connecting thread section, the lower end of the top fixing shaft and the lower end of the bottom fixing shaft are respectively screwed through the connecting screw holes corresponding to the positions on the fixing base plate and locked by nuts.

[0010] Further, the bottom pressing cover and the top pressing cover are provided with rotating handles.

[0011] Further, the top fixing assembly and the shaping shaft are distributed transversely side by side, and the bottom fixing assembly is located at the left rear side of the shaping column.

[0012] Further, the connecting piece comprises a connecting plate and a stud bolt, the connecting plate is vertically fixed at the left end of the fixing base plate, the stud bolt is horizontally arranged, one end of the stud bolt is connected to the middle part of the connecting plate, the other end of the stud bolt is used for being connected to the universal material testing machine, and a limiting nut is screwed on the stud bolt.

[0013] Further, the groove width of the thread groove is 0.1mm larger than the diameter of the NiTi memory alloy wire.

[0014] Further, the groove width of the thread groove is twice the diameter of the NiTi memory alloy wire.

[0015] Another technical solution adopted by the present application is a simple NiTi shape memory spring winding and heat setting method, comprising two simple NiTi shape memory spring winding devices and a heat setting mold, the heat setting mold comprises a cylindrical mold body with an opening on the side, connecting lugs are symmetrically arranged on both sides of the opening on the mold body, and the connecting lugs on both sides of the opening are locked by cooperating with the locking bolt and the locking nut; the winding and heat forming process comprises the following steps:

[0016] (1) winding and stretching:

[0017] Step S1: in one of the winding devices, one end of the NiTi memory alloy wire is pressed on the bottom fixing shaft through the bottom pressing cover, then the NiTi memory alloy wire is wound along the thread groove of the shaping column from bottom to top until the end of the thread groove, then the NiTi memory alloy wire extends to the other winding device after winding around the top fixing shaft; in the other winding device, the NiTi memory alloy wire is first wound around the top fixing shaft, then wound along the thread groove of the shaping column from top to bottom to the end of the thread groove, and then the NiTi memory alloy wire is pressed on the bottom fixing shaft through the bottom pressing cover.

[0018] Step S2: two winding devices are fixed respectively by double-end bolts on the upper and lower parts of the universal material testing machine, after the fixing is completed, the universal material testing machine is operated to be lifted upward to reach a certain pre-tightening force and then kept still, then the top gland of the two winding devices is screwed on the top fixing shaft respectively, the NiTi memory alloy wire is fixed to the top fixing shaft through the top gland; after the fixing is completed, the universal material testing machine is unloaded, at this time, the NiTi alloy wire is formed into the required shape, finally, the NiTi memory alloy wire is cut off at the tangent position of the shaping column and the NiTi memory alloy wire, and the NiTi memory alloy spring which has not undergone memory training can be obtained;

[0019] (2) heat setting: the NiTi memory alloy spring which has not undergone heat setting is screwed into the threaded groove of the shaping column, then the heat setting mold is sleeved outside the shaping column, and then the two connecting lugs at the side opening of the heat setting mold are locked by the locking bolt and the locking nut; then the high-temperature heating furnace is preheated to 300°C, the installed heat setting mold is put into the high-temperature heating furnace for heating, and the temperature is continuously increased to 500°C and kept for half an hour; after the heat preservation is completed, the heating is stopped, and the spring is taken out after cooling, and the shaping is completed, at this time, the memory alloy remembers the shape of the spring.

[0020] Compared with the prior art, the present application has the following effects: the present application is simple and reasonable in design, small in equipment volume, and only uses some general equipment, can be arranged in a smaller space such as a laboratory, and is simple to operate, under the premise of ensuring the dimensional accuracy of the NiTi shape memory spring, greatly simplifies the preparation process, greatly improves the laboratory efficiency, and has high application value. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is the exploded view of the embodiment of the present application;

[0023] Figure 2 is the stretching schematic view of the embodiment of the present application;

[0024] Figure 3 is the structural schematic view of the shaping column in the embodiment of the present application;

[0025] Figure 4 is the assembly schematic view of the heat setting mold and the shaping column in the embodiment of the present application;

[0026] Figure 5 is the A-A sectional structural schematic view in Figure 4

[0027] Figure 6 is the three-dimensional structural view of the heat setting mold in the embodiment of the present application;

[0028] Figure 7 is the exploded state schematic view of the heat setting in the embodiment of the present application.​

[0029] In the drawings:

[0030] 1 - fixed bottom plate; 2 - double head bolt; 3 - limiting nut; 4 - bottom fixed shaft; 5 - bottom gland; 6 - top gland; 7 - shaping column; 8 - top fixed shaft; 9 - connecting screw hole; 10 - nut; 11 - NiTi memory alloy wire; 12 - connecting lug; 13 - locking bolt; 14 - locking nut; 15 - heat setting mold; 16 - mold body; 17 - bottom fixed flange; 18 - top fixed flange; 19 - rotating handle; 20 - connecting threaded section; 21 - connecting plate; 22 - threaded groove. DETAILED DESCRIPTION:

[0032] The application will be further described in detail below in conjunction with the drawings and specific embodiments.

[0033] In the description of the application, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0034] As Figures 1-3 shown, the application is a simple NiTi shape memory spring winding device, which is designed for the need of small-scale manufacturing of NiTi memory alloy springs in the laboratory, and specifically comprises a fixed bottom plate 1, one end of the fixed bottom plate 1 is provided with a connecting piece for connecting with a universal material testing machine, a shaping column 7 is vertically arranged on the fixed bottom plate 1, a threaded groove 22 is arranged on the outer circumferential side of the shaping column 7 to facilitate the spiral winding of the NiTi memory alloy wire, and the threaded groove 22 extends along the axial direction of the shaping column 7; a bottom fixing assembly for fixing the lower end of the NiTi memory alloy wire 11 spirally wound on the shaping column is arranged on the side of the shaping column 7 close to the connecting piece, and a top fixing assembly for fixing the upper end of the NiTi memory alloy wire 11 spirally wound on the shaping column is arranged on the side of the shaping column 7 away from the connecting piece.

[0035] In this embodiment, the shaping column 7, the bottom fixing assembly and the top fixing assembly are all screwed with the fixed bottom plate for easy assembly and disassembly.

[0036] Specifically, the bottom fixing assembly comprises a vertically arranged bottom fixing shaft 4, the lower end of the bottom fixing shaft 4 is screwed with the fixed bottom plate 1, the middle part of the bottom fixing shaft 4 is provided with a ring-shaped bottom fixing flange 17, the upper end of the bottom fixing shaft 4 is screwed with a bottom gland 5 for pressing the lower end of the NiTi memory alloy wire 11 on the top surface of the bottom fixing flange 17, the bottom gland is in a cylindrical shape; the top fixing assembly comprises a vertically arranged top fixing shaft 8, the lower end of the top fixing shaft 8 is screwed with the fixed bottom plate 1, the outer circumferential side of the top fixing shaft 8 is provided with a ring-shaped top fixing flange 18, the upper end of the top fixing shaft 8 is screwed with a top gland 6 for pressing the upper end of the NiTi memory alloy wire 11 on the top surface of the top fixing flange 18, the top gland is in a cylindrical shape.

[0037] In the embodiment, the fixed bottom plate 1 is provided with connecting screw holes 9 corresponding to the positions of the shaping column 7, the bottom fixing shaft 4 and the top fixing shaft 8, the middle part of the bottom surface of the shaping column 7 is provided with a downward protruding connecting threaded section 20, the connecting threaded section 20, the lower end of the top fixing shaft 8 and the lower end of the bottom fixing shaft 4 are respectively screwed through the connecting screw holes 9 corresponding in position on the fixed bottom plate 1 and locked by nuts 10, so as to be connected and fixed with the fixed bottom plate.

[0038] In the embodiment, in order to facilitate the rotation of the bottom and top glands, the bottom gland 5 and the top gland 6 are both provided with rotating handles 19.

[0039] In the embodiment, the top fixing assembly and the shaping shaft 7 are distributed in parallel along the transverse direction; the bottom fixing assembly is located at the left rear side of the shaping column 7.

[0040] In the embodiment, the connecting piece comprises a connecting plate 21 and a stud bolt 2, the connecting plate 21 is vertically fixed on the left end of the fixed bottom plate 1, the stud bolt 2 is horizontally arranged, one end of the stud bolt 2 is connected with the connecting screw hole in the middle part of the connecting plate 21, the other end of the stud bolt 2 is used for being connected with the universal material testing machine. Further, a limiting nut 3 is screwed on the stud bolt 2, the limiting nut limits the stud bolt.

[0041] In the embodiment, during installation, first, the bottom fixing shaft 4, the shaping column 7 and the top fixing shaft 8 are fixed on the fixed bottom plate 1 according to the connecting screw hole sequence in the drawing, and then locked by the nuts 10; second, the stud bolt 2 is fixed on the connecting plate at one end of the fixed bottom plate 1 and limited by the limiting nut 3; then, one end of the NiTi memory alloy wire 11 is fixed on the bottom fixing shaft 4 through the bottom gland 5, and then the NiTi memory alloy wire 11 is slowly wound from the bottom to the top along the threaded groove 22 on the shaping column 7 until the end of the threaded groove 22, and then wound to the other same winding device according to the wiring in the drawing and fixed. Figure 2 ​

[0042] In this embodiment, as shown in Figures 4-7 The heat setting mold 15 includes a cylindrical mold body 16 with openings on the side, which is used to be sleeved outside the setting column 7, and connecting lugs 12 are symmetrically arranged on the mold body 16 on both sides of the openings, and a plurality of round holes are arranged on the connecting lugs 12 along the length direction. The connecting lugs 12 on both sides of the openings are locked by cooperating with the locking bolt 13 and the locking nut 14, so as to lock the heat setting mold. During heat setting, the heat setting mold 15 is sleeved outside the setting column 7, and the heat setting mold 15 is locked by cooperating with the locking bolt 13 and the locking nut 14, so that the heat setting mold can only compress the NiTi memory alloy spring 11 on the setting column to achieve the purpose of limiting deformation. The heat setting mold mainly limits the deformation of the spring in the radial direction, and the setting column 7 has the functions of limiting the spring in the axial and radial directions, and the combination of the two ensures the fixation of the diameter and the pitch of the spring.

[0043] In this embodiment, the groove width of the thread groove 22 is 0.1 mm larger than the diameter of the NiTi memory alloy wire 11, which is beneficial to the smooth taking out of the memory alloy spring after forming.

[0044] In this embodiment, the groove width of the thread groove 22 is twice the diameter of the NiTi memory alloy wire 11, so that the heat setting mold can fully limit the memory alloy spring when locked to prevent radial deformation.

[0045] In this embodiment, in order to facilitate the taking out of the product after setting, the surface of the heat setting mold needs to be processed to keep a low roughness.

[0046] In this embodiment, a simple NiTi shape memory spring winding and heat setting method includes two simple NiTi shape memory spring winding devices and a heat setting mold, and the winding and heat setting includes the following steps:

[0047] (1) Winding and stretching:

[0048] Step S1: In one of the winding devices, one end of the NiTi memory alloy wire is pressed on the bottom fixed shaft 4 by the bottom pressing cover 5, and then the NiTi memory alloy wire 11 is wound from bottom to top along the thread groove of the setting column 7 until the end of the thread groove 22, and then the NiTi memory alloy wire 11 extends to the other winding device after winding around the upper end of the top fixed shaft 8. In the other winding device, the NiTi memory alloy wire 11 first winds around the top fixed shaft 8, and then winds from top to bottom along the thread groove 22 of the setting column 7 to the end of the thread groove 22, and then the NiTi memory alloy wire 11 is pressed on the bottom fixed shaft 4 by the bottom pressing cover 5;

[0049] Step S2: two winding devices are fixed on the upper and lower parts of the universal material testing machine through double-headed bolts respectively, after the fixing is completed, the universal material testing machine is operated to be lifted upward to reach a certain pre-tightening force and then kept still, then the top gland 6 of the two winding devices is screwed on the top fixing shaft 8 respectively, the NiTi memory alloy wire 11 is fixed on the top fixing shaft 8 through the top gland 6, after the fixing is completed, the universal material testing machine is unloaded, at this time, the NiTi alloy wire is formed into the required shape, finally, the NiTi memory alloy wire is cut off at the tangent position of the setting column and the NiTi memory alloy wire, and the NiTi memory alloy spring without memory training is obtained;

[0050] (2) heat setting: the NiTi memory alloy spring without heat setting is screwed into the threaded groove 22 of one setting column 7, then the heat setting mold 15 is sleeved on the outside of the setting column 7, and then the two connecting lugs 12 at the side opening of the heat setting mold 15 are locked through the locking bolt 13 and the locking nut 14; then the high-temperature heating furnace is preheated to 300°C, the installed heat setting mold 15 is put into the high-temperature heating furnace for heating, the temperature is continuously increased to 500°C, and the temperature is kept for half an hour; after the temperature keeping is completed, the heating is stopped, the spring is taken out after cooling, and the setting is completed, at this time, the memory alloy remembers the shape of the spring.

[0051] The advantage of the present application is that the winding device and the heat setting mold are designed in combination with the universal material testing machine, the high-temperature heating furnace and other general equipment to realize the winding and heat setting process flow of the NiTi shape memory spring, the process is simple, the economy is good, the equipment volume is small, the operation is simple, different spring diameters, pitches, wire diameters and other geometric sizes of the NiTi shape memory alloy spring can be conveniently and quickly realized, the size precision of the NiTi shape memory spring is ensured, the preparation process is greatly simplified, the laboratory efficiency is greatly improved, the application value is high, the shortcomings of the conventional spring preparation equipment, such as large volume, inflexible specification adjustment and no heat setting mold, are solved.

[0052] If the present application discloses or involves mutually fixed and connected parts or structural members, except otherwise stated, the fixed connection can be understood as: detachable fixed connection (for example, bolt or screw connection), and can also be understood as: non-detachable fixed connection (for example, riveting, welding), of course, the mutual fixed connection can also be replaced by an integral structure (for example, integrally formed by using casting process) (except obviously cannot use integral forming process).

[0053] In addition, the terms used to represent the position relationship or shape in any of the technical solutions disclosed in the present application include the approximate, similar or close state or shape, except otherwise stated.

[0054] Any of the components provided herein can be assembled components or unitary components manufactured by an integral molding process.

[0055] It should be noted that the above examples are only used to illustrate the technical solutions of the present application, but not limit the present application; although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalent ones; without departing from the spirit of the technical solutions of the present application, all of them should be covered in the technical solution range of the present application claimed.

Claims

1. A simple NiTi shape memory spring winding apparatus characterized by: The device comprises a fixed base plate provided with a connecting piece at one end for connecting with a universal material testing machine, a vertical setting shaping column on the fixed base plate, a thread groove on the outer circumferential side of the shaping column for facilitating spiral winding of the NiTi memory alloy wire, the thread groove extending along the axial direction of the shaping column, a bottom fixing assembly on the side of the shaping column close to the connecting piece for fixing the lower end of the NiTi memory alloy wire spirally wound on the shaping column, and a top fixing assembly on the side of the shaping column away from the connecting piece for fixing the upper end of the NiTi memory alloy wire spirally wound on the shaping column. The shaping column is screwed with the fixed base plate; the bottom fixing assembly comprises a vertical setting bottom fixing shaft screwed with the fixed base plate, an annular bottom fixing flange provided on the middle part of the bottom fixing shaft, and a bottom pressing cover screwed on the upper end of the bottom fixing shaft for pressing the lower end of the NiTi memory alloy wire on the top surface of the bottom fixing flange; the top fixing assembly comprises a vertical setting top fixing shaft screwed with the fixed base plate, an annular top fixing flange provided on the outer circumferential side of the top fixing shaft, and a top pressing cover screwed on the upper end of the top fixing shaft for pressing the upper end of the NiTi memory alloy wire on the top surface of the top fixing flange. The fixed base plate is provided with connecting screw holes corresponding to the positions of the shaping column, the bottom fixing shaft and the top fixing shaft, the bottom surface of the shaping column is provided with a downward protruding connecting thread section, and the connecting thread section, the lower end of the top fixing shaft and the lower end of the bottom fixing shaft are respectively screwed through the connecting screw holes corresponding in position on the fixed base plate and locked by nuts.

2. A simple NiTi shape memory spring winding apparatus as claimed in claim 1, wherein: The bottom pressing cover and the top pressing cover are both provided with rotating handles.

3. The simple NiTi shape memory spring winding apparatus according to claim 1, characterized in that: The top fixing assembly and the shaping shaft are distributed in parallel along the transverse direction; the bottom fixing assembly is located on the left rear side of the shaping column.

4. The simple NiTi shape memory spring winding apparatus according to claim 1, characterized in that: The connecting piece comprises a connecting plate and a stud bolt, the connecting plate is vertically fixed on the left end of the fixed base plate, the stud bolt is horizontally arranged, one end of the stud bolt is connected with the middle part of the connecting plate, the other end of the stud bolt is used for connecting with the universal material testing machine, and a limiting nut is further screwed on the stud bolt.

5. The simple NiTi shape memory spring winding apparatus according to claim 1, characterized in that: The groove width of the thread groove is 0.1 mm larger than the diameter of the NiTi memory alloy wire.

6. The simple NiTi shape memory spring winding apparatus according to claim 1, characterized in that: The groove width of the thread groove is twice the diameter of the NiTi memory alloy wire.

7. A simple method of NiTi shape memory spring winding and hot forming, characterized in that: The device comprises two simple NiTi shape memory spring winding devices and a heat setting mold, the heat setting mold comprises a cylindrical mold body with an opening on the side, connecting lugs are symmetrically arranged on both sides of the opening on the mold body, the connecting lugs on both sides of the opening are locked by cooperating a locking bolt and a locking nut; the winding and heat setting comprises the following steps: (1) Winding and stretching: Step S1: In one of the winding devices, one end of the NiTi memory alloy wire is pressed on the bottom fixed shaft by the bottom gland, and then the NiTi memory alloy wire is wound from bottom to top along the threaded groove of the shaping column until the end of the threaded groove, and then the NiTi memory alloy wire extends to the other winding device after winding around the top fixed shaft; in the other winding device, the NiTi memory alloy wire first winds around the top fixed shaft, and then winds from top to bottom along the threaded groove of the shaping column to the end of the threaded groove, and then the NiTi memory alloy wire is pressed on the bottom fixed shaft by the bottom gland; Step S2: The two winding devices are respectively fixed on the upper and lower parts of the universal material testing machine by means of double-headed bolts, and after the fixing is completed, the universal material testing machine is lifted upward to a certain pre-tightening force and then kept stationary, then the top glands of the two winding devices are respectively screwed on the top fixed shaft, and the NiTi memory alloy wire is fixed on the top fixed shaft by the top gland; after the fixing is completed, the universal material testing machine is unloaded, at this time the NiTi alloy wire is formed into the required shape, and finally the NiTi memory alloy wire is cut at the tangent between the shaping column and the NiTi memory alloy wire, that is, the NiTi memory alloy spring which has not undergone memory training can be obtained; (2) Heat setting: the NiTi memory alloy spring which has not undergone heat setting is screwed into the threaded groove of the shaping column, then the heat setting mold is sleeved outside the shaping column, and then the two connecting lugs at the opening of the heat setting mold are locked by the locking bolt and the locking nut; then the high temperature heating furnace is preheated to 300°C, and then the installed heat setting mold is put into the high temperature heating furnace for heating, and the temperature is continued to rise to 500°C and kept for half an hour; after the heat preservation is completed, stop heating, and take out the spring after cooling, which completes the shaping, at this time the memory alloy remembers the shape of the spring.

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