Electrochemical polishing device and polishing method for vascular stent

Abstract

The present invention relates to the technical field of polishing, and discloses an electrochemical polishing device and a polishing method for a vascular stent. The polishing device comprises a lifting assembly, an anode assembly, an adjustment assembly and a cathode assembly, wherein the lifting assembly comprises a lifting frame and a first driving mechanism; the anode assembly comprises an anode, an elastic member, a vibration source and a metal wire connected in sequence, the metal wire is used to install the vascular stent, and the metal wire has a contracted state that can be movably connected to the vascular stent and an open state that can be fixedly connected to the vascular stent; the adjustment assembly comprises a first support frame and a second driving mechanism, the first support frame is connected to the metal wire, and the first support frame has a vertical position that can make the metal wire in a contracted state and a horizontal position that can make the metal wire in an open state; the cathode assembly is arranged below the anode assembly, and the cathode assembly comprises a polishing cylinder containing a polishing liquid and a cathode arranged in the polishing cylinder. The present invention has a simple and compact structure, is easy to operate, and has uniform polishing, good effect and high efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of polishing, and in particular relates to an electrochemical polishing device and a polishing method applied to a CoCr alloy vascular stent. Background Art

[0002] Interventional therapy is the main method for treating vascular obstruction diseases. As a key component of interventional therapy, vascular stents have gradually become the focus of research. CoCr alloy has good mechanical properties, small specific gravity, light weight, stable chemical properties and strong corrosion resistance. It is also non-irritating to the body and can be used as a implant material. Therefore, CoCr alloy has gradually become a new material for vascular stents.

[0003] During the production and processing of CoCr alloy vascular stents, it is necessary to laser engrave the tube, which will generate a heat-affected zone and a recast layer at the cutting position on its surface. These protruding molten fragments affect the surface smoothness of the vascular stent. After the vascular stent is implanted in the human body, it will stimulate the proliferation of the vascular intima, thereby increasing the risk of restenosis. Therefore, the surface of the vascular stent needs to be polished after the vascular stent is formed. In the existing polishing method, the vascular stent has uneven contact, the reaction of the polishing liquid and the slag is insufficient, and a long time of reaction is required to achieve the ideal effect, so that the entire polishing process requires a lot of energy and time, and the polishing effect is not ideal. For example, there is a method for electrochemical polishing of a magnesium vascular stent disclosed in Chinese patent CN106435706A, which mainly solves the problem that mechanical polishing cannot achieve polishing accuracy and consumes a lot of time and manpower; Chinese patent CN203890489U discloses a vascular stent electrochemical polishing device, which includes an automatic rotating device to achieve bidirectional polishing of the stent. Although the vascular stent polishing method disclosed in the above patent improves the polishing steps in the vascular stent manufacturing process and improves the polishing effect, it does not fundamentally solve the problems of low efficiency, uneven polishing, complex procedures and low degree of automation existing in the existing vascular stent polishing devices and polishing methods.

[0004] Therefore, there is an urgent need for an electrochemical polishing device and polishing method for a vascular stent to solve the above problems. Summary of the invention

[0005] Based on the above, the object of the present invention is to provide an electrochemical polishing device and a polishing method for a CoCr alloy vascular stent, which has reliable principle, simple operation, high polishing efficiency and good polishing effect.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides an electrochemical polishing device for a vascular stent, comprising:

[0008] A lifting assembly, comprising a lifting frame and a first driving mechanism, wherein the first driving mechanism is connected to the lifting frame and is used to drive the lifting frame to move up and down in a vertical direction;

[0009] An anode assembly, comprising an anode, an elastic member, a vibration source and a metal wire, wherein the anode is fixed to the lifting frame, the upper end of the elastic member is connected to the anode, the lower end of the elastic member is connected to the vibration source, the lower end of the vibration source is connected to the metal wire via a metal clip, the metal wire is used to install a blood vessel stent, and the metal wire has a contracted state capable of being movably connected to the blood vessel stent and an open state capable of being fixedly connected to the blood vessel stent;

[0010] The adjustment assembly includes a first support frame and a second driving mechanism, wherein the first support frame is connected to the metal wire, and the first support frame has a vertical position that enables the metal wire to be in a contracted state and a horizontal position that enables the metal wire to be in an extended state; the second driving mechanism is connected to the first support frame and is used to drive the first support frame to switch between the vertical position and the horizontal position;

[0011] The cathode assembly is arranged below the anode assembly, and the cathode assembly comprises a polishing cylinder filled with polishing liquid and a cathode arranged in the polishing cylinder.

[0012] As a preferred embodiment of the electrochemical polishing device for a vascular stent, the first support frame is a "Y"-shaped support frame, including a trunk end, a first branch end and a second branch end, the trunk end is connected to the second driving mechanism, and the first branch end and the second branch end are respectively connected to the bottom end of the metal wire.

[0013] As a preferred solution of an electrochemical polishing device for a vascular stent, the trunk end of the first support frame includes a first arm and a second arm connected in an L shape, and the first arm is connected to the first branch end and the second branch end;

[0014] The second driving mechanism includes a crank, a second support frame and a connecting rod. One end of the second support frame is fixed to the lifting frame, and the other end is movably connected to the first arm. The crank is connected to one end of the connecting rod, and the other end of the connecting rod is connected to the second arm. The first support frame can be switched between a vertical position and a horizontal position by rotating the crank.

[0015] As a preferred solution of the electrochemical polishing device for a vascular stent, the cathode assembly further comprises a stirring mechanism for stirring the polishing liquid, the stirring mechanism comprising a magnetic rod disposed in the polishing cylinder and a magnetic field device disposed below the polishing cylinder. Preferably, the magnetic rod is in the shape of a shuttle.

[0016] As a preferred solution of the electrochemical polishing device for a vascular stent, a thermostat is also provided in the polishing cylinder for adjusting the temperature of the polishing liquid in the polishing cylinder.

[0017] As a preferred solution of the electrochemical polishing device for a vascular stent, the cathode is cylindrical in shape, and a plurality of liquid holes are evenly distributed on the wall of the cathode. Preferably, the diameter of the liquid holes is 5 to 8 mm, and the hole spacing is 10 to 15 mm.

[0018] As a preferred solution of the electrochemical polishing device for a vascular stent, the material of the metal wire is platinum wire; the material of the cathode is SUS304.

[0019] Preferably, the anode is a platinum wire with a diameter ranging from 0.1 to 1.0 mm; and the metal wire is a platinum wire with a diameter ranging from 0.1 to 0.5 mm.

[0020] As a preferred solution of the electrochemical polishing device for a vascular stent, the first driving mechanism includes a motor, a screw rod transmission-connected to the motor, and a nut threadedly connected to the screw rod, and the nut is fixedly connected to the lifting frame.

[0021] The present invention also provides a polishing method for a vascular stent, comprising:

[0022] S1. Mix the required polishing liquid in the polishing cylinder according to the proportion, set the polishing temperature, start the stirring mechanism in the polishing cylinder, and stir the polishing liquid in real time;

[0023] S2, remove the metal wire, put the vascular stent on the metal wire, tighten the elastic member, and clamp the metal wire with the metal clip at the bottom of the vibration source to complete the installation of the vascular stent;

[0024] S3, twisting the crank to rotate the first support frame 90° counterclockwise to a vertical position, at which time the vascular stent reaches the bottom end of the metal wire; twisting the crank again to rotate the first support frame 90° clockwise to a horizontal position, so that the metal wire is in full contact with the vascular stent, and placing the vascular stent into the polishing cylinder;

[0025] S4, turning on the power supply, setting the voltage value, current value and polishing time, and starting to polish the vascular stent;

[0026] S5, disconnecting the power supply, twisting the crank, rotating the first support frame 90° counterclockwise to a vertical position, separating the vascular stent from the metal wire, and starting the vibration source to rotate the vascular stent through vibration to change the power-on position;

[0027] S6, twisting the crank again to rotate the first support frame 90° clockwise to a horizontal position, so that the metal wire is in full contact with the vascular stent;

[0028] S7, repeat steps S4-S6, and the entire polishing process is repeated n times until the required polishing accuracy is achieved.

[0029] As a preferred solution for a polishing method of a vascular stent, the polishing liquid comprises, by mass ratio: sulfuric acid: 10-20%, methanol: 80-90%; the voltage value is 10-20V, the current value is 1.0-2.0A, and the polishing temperature is 5-10°C; the polishing time of each cycle is 10-20 seconds, and the entire polishing process is repeated 3-6 times, steps S4-S6.

[0030] The beneficial effects of the present invention are:

[0031] The polishing device for the vascular stent provided by the embodiment of the present invention is that when the metal wire is in an open state, the vascular stent is fixedly connected to the metal wire, so that the surface of the vascular stent can be stably polished; when the metal wire is in a contracted state, the vascular stent is movably connected to the metal wire, and at this time, the metal wire is driven to vibrate by a vibration source, so that the contact position between the vascular stent and the metal wire changes, thereby preventing over-polishing and making the polishing more uniform; the present invention polishes the vascular stent step by step by adjusting the contact position between the vascular stent and the metal wire, so that the polishing effect is better, which is beneficial to improving the quality of the vascular stent. Moreover, the present invention drives the lifting frame to move up and down in the vertical direction through the first driving mechanism, so as to adjust the position of the anode assembly in the polishing cylinder; drives the first support frame to switch between the vertical position and the horizontal position through the second driving mechanism, so as to realize the conversion of the metal wire between the contracted state and the open state; it has a simple and compact structure, is easy to operate, and avoids the cumbersome procedures of the traditional electrochemical polishing device.

[0032] Compared with the existing electrochemical polishing method of the vascular stent, the polishing method provided by the embodiment of the present invention realizes step-by-step polishing of the vascular stent by intermittently changing the position direction of the vascular stent, and can effectively remove the oxide layer and fragments on the surface of the vascular stent caused by laser cutting, so that the surface polishing of the vascular stent is more uniform and the polishing effect is better. It is also simple to operate, has high polishing efficiency and high safety factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic structural diagram of an electrochemical polishing device for a vascular stent provided in Example 1 of the present invention;

[0034] Figure 2 The partial structure diagram of the electrochemical polishing device of the vascular stent provided in the first embodiment of the present invention is shown in FIG. Figure 1 (the first support frame is in a horizontal position);

[0035] Figure 3 The partial structure diagram of the electrochemical polishing device of the vascular stent provided in the first embodiment of the present invention is shown in FIG. Figure 2(the first support frame is in a vertical position);

[0036] Figure 4 is a schematic structural diagram of a first support frame involved in Embodiment 1 of the present invention;

[0037] Figure 5 is a schematic structural diagram of a cathode involved in Embodiment 1 of the present invention;

[0038] Figure 6 This is a schematic diagram of the process of polishing a vascular stent involved in the second embodiment of the present invention.

[0039] The reference numerals in the figures are as follows:

[0040] 1-anode; 2-elastic member; 3-vibration source; 4-metal wire; 5-vascular stent; 6-polishing cylinder; 7-cathode; 71-liquid hole; 8-polishing liquid; 9-first support frame; 91-trunk end; 911-first arm; 912-second arm; 92-first branch end; 93-second branch end; 10-second support frame; 11-connecting rod; 12-crank; 13-lifting frame; 14-magnetic rod; 15-thermostat; 16-first driving mechanism; 17-controller; 18-switch. DETAILED DESCRIPTION

[0041] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0042] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0044] In the description of this embodiment, the terms "upper", "lower", "left", "right", etc., and the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0045] Embodiment 1

[0046] Figure 1 It is a schematic diagram of the structure of the electrochemical polishing device for the vascular stent provided in this embodiment. Figure 2 The partial structure diagram of the electrochemical polishing device of the vascular stent provided in this embodiment is Figure 1 (The first support frame is in a horizontal position). Figure 3 The partial structure diagram of the electrochemical polishing device of the vascular stent provided in this embodiment is Figure 2 (The first support frame is in a vertical position). Figure 4 It is a schematic structural diagram of the first support frame 9 involved in this embodiment. Figure 5 Schematic diagram of the structure of the cathode 7 involved in this embodiment. Figure 1-Figure 5 As shown, this embodiment provides an electrochemical polishing device for a vascular stent, which is used to electrochemically polish the surface of the vascular stent 5, and is particularly useful for electrochemically polishing the heat-affected zone, recast layer, etc. formed on the surface of the CoCr alloy vascular stent 5 after laser processing.

[0047] refer to Figure 1The polishing device includes a lifting assembly, an anode assembly, an adjustment assembly and a cathode assembly, wherein the lifting assembly includes a lifting frame 13 and a first driving mechanism 16, the first driving mechanism 16 is connected to the lifting frame 13, and is used to drive the lifting frame 13 to move up and down in the vertical direction, so that the anode assembly can be placed in the polishing liquid 8 or taken out from the polishing liquid 8, and the position of the anode assembly in the polishing cylinder 6 can be adjusted. Preferably, the first driving mechanism 16 of this embodiment includes a motor, a screw rod connected to the motor in a transmission manner, and a nut threadedly connected to the screw rod, the nut is fixedly connected to the lifting frame 13, and the motor is connected to the controller 17. The above-mentioned setting structure is simple and reliable in operation; the motor is controlled by the controller 17 to operate, so that the lifting frame 13 can be accurately driven to rise and fall.

[0048] The anode assembly includes an anode 1, an elastic member 2, a vibration source 3 and a metal wire 4. The anode 1 is fixed on a lifting frame 13 and connected to the positive electrode of a power source. The anode 1 can move up and down with the lifting frame 13. The upper end of the elastic member 2 is connected to the anode 1, and the lower end of the elastic member 2 is connected to the vibration source 3. The elastic member 2 is used to straighten the metal wire 4. Preferably, the elastic member 2 is a spring. The lower end of the vibration source 3 is connected to the metal wire 4 through a metal clip. The vibration source 3 is used to change the contact point between the metal wire 4 and the vascular stent 5 through vibration energy, so that the vascular stent 5 can rotate relative to the metal wire 4 and move slightly up and down to prevent over-polishing.

[0049] The metal wire 4 is used to install the vascular stent 5, such as Figure 1 As shown, the metal wire 4 can be a platinum wire in an annular structure, the upper end of which is hung on the metal clip, and the lower end has two connection points. When the two connection points are arranged horizontally, the lower end of the metal wire 4 is stretched open, and the metal wire 4 is in an open state, and the vascular stent 5 can be clamped on the metal wire 4; when the two connection points are arranged vertically, the lower end of the metal wire 4 is closed, and the metal wire 4 is in a contracted state, and the vascular stent 5 can slide along the metal wire 4 under the action of gravity or vibration force, and can rotate relative to the metal wire 4. The adjustment component includes a first support frame 9 and a second drive mechanism, the first support frame 9 is connected to the metal wire 4, and the first support frame 9 has a vertical position that can make the metal wire 4 in a contracted state and a horizontal position that can make the metal wire 4 in an open state; the second drive mechanism is connected to the first support frame 9, and is used to drive the first support frame 9 to switch between the vertical position and the horizontal position, thereby realizing the conversion of the metal wire 4 between the contracted state and the open state. The cathode assembly is arranged below the anode assembly, and the cathode assembly comprises a polishing cylinder 6 filled with polishing liquid 8 and a cathode 7 fixed to the bottom of the polishing cylinder 6, and the cathode 7 is connected to the negative pole of the power supply.

[0050] In this embodiment, when the metal wire 4 is in an open state, the vascular stent 5 is fixedly connected to the metal wire 4, so that the surface of the vascular stent 5 can be stably polished; when the metal wire 4 is in a contracted state, the vascular stent 5 is movably connected to the metal wire 4, and the metal wire 4 is driven to vibrate by the vibration source 3, so that the contact position between the vascular stent 5 and the metal wire 4 changes to prevent over-polishing and make the polishing more uniform. The present invention polishes the vascular stent 5 step by step by adjusting the contact position between the vascular stent 5 and the metal wire 4, so that the polishing effect is better, which is conducive to improving the surface quality of the vascular stent 5. The polishing device provided in this embodiment has a simple and compact structure, is easy to operate, can effectively remove the oxide layer and fragments on the surface of the vascular stent 5 caused by laser cutting, and has a good polishing effect and high polishing efficiency, avoiding the cumbersome procedures of traditional electrochemical polishing devices.

[0051] As a preference, refer to Figure 4 , the first support frame 9 of this embodiment is a "Y"-shaped support frame, including a trunk end 91, a first branch end 92 and a second branch end 93, the trunk end 91 is connected to the second driving mechanism, and the first branch end 92 and the second branch end 93 are connected to two connection points at the bottom end of the metal wire 4; the above-mentioned arrangement enables that when the second driving mechanism drives the trunk end 91 to rotate, the first branch end 92 and the second branch end 93 can rotate accordingly, so that the two connection points where the first branch end 92 and the second branch end 93 are connected to the metal wire 4 can be arranged in the horizontal direction or in the vertical direction. Furthermore, the trunk end 91 of the first support frame 9 includes a first arm 911 and a second arm 912 connected in an L-shape, wherein the first arm 911 is connected to the first branch end 92 and the second branch end 93, and the second arm 912 is perpendicular to the first arm 911. With such an arrangement, the first support frame 9 can be easily switched between the vertical position and the horizontal position by twisting the second arm 912. Figure 1-Figure 3 As shown, preferably, the second driving mechanism of this embodiment includes a crank 12, a second support frame 10 and a connecting rod 11, one end of the second support frame 10 is fixed to the lifting frame 13, and the other end is movably connected to the first arm 911; one end of the crank 12 is rotatably connected to the support frame 10, and the other end is connected to one end of the connecting rod 11; the other end of the connecting rod 11 is fixedly connected to the second arm 912. The above-mentioned arrangement has a simple structure and is easy to operate. By twisting the crank 12, the position direction of the first support frame 9 can be changed to achieve its switching between the vertical position and the horizontal position.

[0052] Further, the cathode assembly also includes a stirring mechanism for stirring the polishing liquid 8, which can make the chemical substances of the polishing liquid 8 in the polishing cylinder 6 uniform, prevent the current density in the solution from changing too much, and affect the polishing quality, and at the same time make the temperature of the solution in the polishing cylinder 6 balanced, and improve the polishing effect. Preferably, the stirring mechanism of this embodiment includes a magnetic rod 14 arranged in the polishing cylinder 6 and a magnetic field device arranged below the polishing cylinder 6, and the magnetic rod 14 is suspended in the lower part of the polishing liquid 8, and can rotate under the magnetic field of the magnetic field device, so as to achieve the stirring of the polishing liquid 8. In this embodiment, when stirring is required, it is only necessary to place the magnetic rod 14 in the polishing liquid 8, and it has a simple structure, is easy to install and use, and is easy to clean and maintain. Further preferably, the shape of the magnetic rod 14 in this embodiment is a shuttle shape, and the shuttle-shaped magnetic rod 14 has good balance, small movement resistance, and is easy to suspend in the central position of the polishing cylinder 6, which effectively improves the uniformity of stirring. Of course, in other embodiments, other stirring devices can also be used, such as stirring by using a motor to drive a stirring blade, which is not limited to this embodiment.

[0053] Furthermore, a thermostat 15 is also provided in the polishing cylinder 6 of this embodiment. The thermostat 15 is preferably fixed to the bottom of the polishing cylinder 6 and is used to adjust the temperature of the polishing liquid 8 in the polishing cylinder 6. By setting the thermostat 15, the polishing liquid 8 is maintained at the optimal polishing temperature, which is beneficial to improving the polishing efficiency and improving the polishing quality.

[0054] As a preference, Figure 5 As shown, in this embodiment, the shape of the cathode 7 is cylindrical, and a plurality of liquid holes 71 are evenly distributed on the wall surface of the cathode 7. Since the vascular stent 5 to be polished is cylindrical in shape, the shape of the cathode 7 is also set to be cylindrical in this embodiment, so that when the vascular stent 5 is immersed in the polishing liquid 8 and is located in the middle of the cathode 7, it can ensure that the distance from the peripheral wall of the cathode 7 to the peripheral wall of the vascular stent 5 is the same, so that the current density in the polishing liquid 8 is consistent, and the dimensional accuracy of the polishing of the vascular stent 5 is improved. The setting of the above-mentioned liquid holes 71 can make the solutions inside and outside the cathode 7 communicate, so that the components of the internal and external solutions are kept uniform and consistent, and the polishing effect is improved. Preferably, the diameter of the liquid holes 71 in this embodiment is 5 to 8 mm, and the hole spacing is 10 to 15 mm.

[0055] In the present invention, since the anode 1 does not enter the polishing liquid during polishing and no electrochemical reaction occurs, the material of the anode 1 only needs to be a conductive metal. Preferably, the anode 1 in this embodiment is a platinum wire with a diameter range of 0.1 to 1.0 mm to increase the service life of the anode 1. Furthermore, since the metal wire 4 will enter the polishing liquid 8 together with the bracket during polishing and produce an electrochemical reaction at the same time, the material of the metal wire 4 needs to have a certain corrosion resistance. In order to increase the service life, platinum wire is preferably used in this embodiment. More preferably, the metal wire 4 is a platinum wire with a diameter range of 0.1 to 0.5 mm. Platinum wire has good corrosion resistance in electrochemical reactions and has a long service life compared to other materials, thereby avoiding the trouble of frequently replacing the metal wire 4. Furthermore, the material of the cathode 7 in this embodiment is SUS304 (i.e., 304 stainless steel), which has high corrosion resistance and can effectively extend the service life of the cathode 7.

[0056] Embodiment 2

[0057] Figure 6 FIG. 1 is a schematic diagram of the polishing process of the vascular stent involved in this embodiment. Figure 6 As shown, this embodiment provides a polishing method for a vascular stent, which is applied to the electrochemical polishing device for the vascular stent in Embodiment 1. The polishing method specifically includes the following steps:

[0058] S1. First, prepare the required polishing liquid 8 in the polishing cylinder 6 in proportion. In this embodiment, preferably, the polishing liquid 8 includes sulfuric acid: 10-20%, methanol: 80-90% by mass. The polishing liquid 8 can effectively polish the molten fragments on the surface of the vascular stent 5 and improve the surface smoothness of the vascular stent 5. Of course, in other embodiments, the appropriate polishing liquid 8 can be flexibly selected as needed, which is not limited to this embodiment. After the polishing liquid 8 is configured, the polishing temperature is set, and the magnetic field device under the polishing cylinder 6 is started to drive the magnetic rod 14 to rotate, thereby stirring the polishing liquid 8 in real time. In this embodiment, preferably, the polishing temperature is 5-10°C, at which temperature the vascular stent 5 can be efficiently polished, thereby improving the quality and efficiency of polishing.

[0059] S2, remove the metal wire 4, put the blood vessel stent 5 on the metal wire 4, tighten the elastic member 2, and clamp the metal wire 4 with the metal clip at the bottom of the vibration source 3 to complete the installation of the blood vessel stent 5, as shown in the following figure: Figure 6 As shown in Figure a.

[0060] S3, twist the crank 12 to rotate the first support frame 9 counterclockwise by 90° to a vertical position, at which time the vascular stent 5 reaches the bottom end of the metal wire 4 under the action of gravity. Figure 6Then, the crank 12 is twisted again to rotate the first support frame 9 clockwise by 90° to a horizontal position, so that the metal wire 4 is in full contact with the vascular stent 5. Figure 6 As shown in Figure c in FIG. Thereafter, the blood vessel stent 5 is placed in the polishing cylinder 6 by the lifting assembly.

[0061] S4, start the switch 18 on the controller 17 to turn on the power supply, set the voltage value, current value and polishing time, and start polishing the stent 5. Preferably, in this embodiment, the voltage value is set to 10-20V, the current value is set to 1.0-2.0A, and the polishing time of each cycle is set to 10-20 seconds.

[0062] S5, turn off the switch 18 on the controller 17 to disconnect the power supply; then twist the crank 12 to rotate the first support frame 9 counterclockwise 90° to a vertical position, so that the vascular stent 5 and the metal wire 4 are movably connected, as shown in detail. Figure 6 Then the vibration source 3 is started to rotate the vascular stent 5 through vibration to change the contact position between the vascular stent 5 and the metal wire 4 to prevent the vascular stent 5 from being over-polished due to long-term power supply at the same position.

[0063] S6, twist the crank 12 again to rotate the first support frame 9 clockwise by 90° to a horizontal position, so that the metal wire 4 is in full contact with the vascular stent 5. Figure 6 As shown in Figure e.

[0064] S7, repeating the above steps S4-S6, that is, performing electrical polishing on the vascular stent 5 again, and adjusting the relative position of the vascular stent 5 and the metal wire 4 again, until the required polishing accuracy is achieved. In this embodiment, preferably, the entire polishing process is repeated 3 to 6 times.

[0065] Compared with the existing electrochemical polishing method for vascular stents, the polishing method provided by the embodiment of the present invention realizes step-by-step polishing of the vascular stent 5 by intermittently changing the position direction of the vascular stent 5, which can effectively remove the oxide layer and fragments generated by laser cutting on the surface of the vascular stent 5, making the surface polishing of the vascular stent 5 more uniform, with better polishing effect, simple operation, high polishing efficiency and high safety factor. After the CoCr alloy tube is laser cut into the vascular stent 5, it is processed by the above-mentioned electrochemical polishing method of this embodiment, and its surface can completely achieve a mirror effect, with a surface roughness of Ra<0.2.

[0066] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An electrochemical polishing device for a vascular stent, characterized in that: include: A lifting assembly comprises a lifting frame (13) and a first driving mechanism (16), wherein the first driving mechanism (16) is connected to the lifting frame (13) and is used to drive the lifting frame (13) to move up and down in a vertical direction; An anode assembly, comprising an anode (1), an elastic member (2), a vibration source (3) and a metal wire (4), wherein the anode (1) is fixed to the lifting frame (13), the upper end of the elastic member (2) is connected to the anode (1), the lower end of the elastic member (2) is connected to the vibration source (3), the lower end of the vibration source (3) is connected to the metal wire (4) via a metal clip, the metal wire (4) is used to install a blood vessel stent (5), and the metal wire (4) has a contracted state capable of being movably connected to the blood vessel stent (5) and an open state capable of being fixedly connected to the blood vessel stent (5); The adjustment component comprises a first support frame (9) and a second driving mechanism, wherein the first support frame (9) is connected to the metal wire (4), and the first support frame (9) has a vertical position capable of causing the metal wire (4) to be in a contracted state and a horizontal position capable of causing the metal wire (4) to be in an extended state; the second driving mechanism is connected to the first support frame (9) and is used to drive the first support frame (9) to switch between the vertical position and the horizontal position; A cathode assembly is arranged below the anode assembly, and comprises a polishing cylinder (6) containing polishing liquid (8) and a cathode (7) arranged in the polishing cylinder (6).

2. The electrochemical polishing device for a vascular stent according to claim 1, characterized in that: The first support frame (9) is a "Y"-shaped support frame, comprising a trunk end (91), a first branch end (92) and a second branch end (93), the trunk end (91) is connected to the second driving mechanism, and the first branch end (92) and the second branch end (93) are respectively connected to the bottom end of the metal wire (4).

3. The electrochemical polishing device for a vascular stent according to claim 2, characterized in that: The trunk end (91) of the first support frame (9) comprises a first arm (911) and a second arm (912) connected in an L-shape, and the first arm (911) is connected to the first branch end (92) and the second branch end (93); The second driving mechanism comprises a crank (12), a second support frame (10) and a connecting rod (11); one end of the second support frame (10) is fixed to the lifting frame (13), and the other end is movably connected to the first arm (911); the crank (12) is connected to one end of the connecting rod (11), and the other end of the connecting rod (11) is connected to the second arm (912); by rotating the crank (12), the first support frame (9) can be switched between a vertical position and a horizontal position.

4. The electrochemical polishing device for a vascular stent according to claim 1, characterized in that: The cathode assembly also includes a stirring mechanism for stirring the polishing liquid (8), wherein the stirring mechanism includes a magnetic rod (14) arranged in the polishing cylinder (6) and a magnetic field device arranged below the polishing cylinder (6).

5. The electrochemical polishing device for a vascular stent according to claim 1, characterized in that: A thermostat (15) is also provided in the polishing cylinder (6) for adjusting the temperature of the polishing liquid (8) in the polishing cylinder (6).

6. The electrochemical polishing device for a vascular stent according to any one of claims 1 to 5, characterized in that: The cathode (7) is cylindrical in shape, and a plurality of liquid-passing holes (71) are evenly distributed on the wall surface of the cathode (7).

7. The electrochemical polishing device for a vascular stent according to any one of claims 1 to 5, characterized in that: The material of the metal wire (4) is platinum wire; the material of the cathode (7) is SUS304.

8. The electrochemical polishing device for a vascular stent according to any one of claims 1 to 5, characterized in that: The first driving mechanism (16) comprises a motor, a screw rod drivingly connected to the motor, and a nut threadedly connected to the screw rod, wherein the nut is fixedly connected to the lifting frame (13).

9. A polishing method for a vascular stent, characterized in that: include: S1, mixing the required polishing liquid (8) in a polishing cylinder (6) according to a certain proportion, setting the polishing temperature, starting the stirring mechanism in the polishing cylinder (6), and stirring the polishing liquid (8) in real time; S2, removing the metal wire (4), putting the vascular stent (5) on the metal wire (4), tightening the elastic member (2), and clamping the metal wire (4) with the metal clamp at the bottom of the vibration source (3), thereby completing the installation of the vascular stent (5); S3, twisting the crank (12) to rotate the first support frame (9) counterclockwise by 90° to a vertical position, at which time the vascular stent (5) reaches the bottom end of the metal wire (4); turning the crank (12) again to rotate the first support frame (9) clockwise by 90° to a horizontal position, so that the metal wire (4) is in full contact with the vascular stent (5), and the vascular stent (5) is placed in the polishing cylinder (6); S4, turning on the power supply, setting the voltage value, current value and polishing time, and starting to polish the vascular stent (5); S5, disconnecting the power supply, rotating the crank (12), causing the first support frame (9) to rotate 90° counterclockwise to a vertical position, separating the vascular stent (5) from the metal wire (4), and starting the vibration source (3), causing the vascular stent (5) to rotate through vibration, thereby changing the energized position; S6, rotating the crank (12) again, so that the first support frame (9) rotates 90° clockwise to a horizontal position, so that the metal wire (4) is in full contact with the vascular stent (5); S7, repeat steps S4-S6, and the entire polishing process is repeated n times until the required polishing accuracy is achieved.

10. The polishing method of a vascular stent according to claim 9, characterized in that: The polishing liquid (8) comprises, by mass ratio, 10-20% sulfuric acid and 80-90% methanol; the voltage value is 10-20V, the current value is 1.0-2.0A, and the polishing temperature is 5-10°C; the polishing time of each cycle is 10-20 seconds, and the entire polishing process is repeated 3-6 times in steps S4-S6.

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