Electrochemical polishing device and method for nickel-titanium alloy intracranial stent

Abstract

The invention discloses a nickel-titanium alloy intracranial stent electrochemical polishing device and method, and relates to the technical field related to medical instruments, the nickel-titanium alloy intracranial stent electrochemical polishing device comprises a polishing workbench and a lifting table arranged on the polishing workbench, the lifting table is provided with a clamp, and the clamp is driven by the lifting table to clamp the nickel-titanium alloy intracranial stent. The clamp clamps the support to enter the polishing solution on the polishing workbench for electrochemical polishing treatment, and the clamp is made of an inert titanium material; the clamp comprises a center rod fixedly connected with the lifting table, a plurality of contact rods are evenly arranged in the circumferential direction of the center rod, and a gap is formed between every two adjacent contact rods. When electrochemical polishing is carried out on the nickel-titanium alloy intracranial stent, the stent is arranged on the outer walls of the multiple contact rods in a sleeving mode.

Description

Technical Field

[0001] The present invention relates to the technical field related to medical devices, and in particular to an electrochemical polishing device and method for a nickel-titanium alloy intracranial stent. Background Art

[0002] It is well known that with the development of neurointerventional technology, nickel-titanium alloy stents are used more and more widely. Due to the limitation of the size of intracranial blood vessels, the characteristics of the stent are small nominal diameter, low metal coverage, and high surface condition requirements. The small nominal diameter of the stent means a thinner stent rod, and the low metal coverage of the stent means more grid units. The stent is in direct contact with the intracranial blood vessels, which means a brighter and smoother surface treatment. The currently better surface treatment is electrochemical polishing, which can effectively remove burrs, protrusions and other appearance defects.

[0003] The device for electrochemical polishing of nickel-titanium alloy intracranial stents is mainly composed of an electrochemical polishing workstation power system, a polishing workbench and an electrochemical polishing temperature control system; Figure 1 As shown in the figure, the working principle of electrochemical polishing of nickel-titanium alloy intracranial stent is as follows: Step 1: inject cooling water 10 into the polishing workbench 1, and add polishing liquid 13 into the beaker 12 where the pure titanium mesh 11 is placed; Step 2: clamp the cathode interface 14 to the edge of the pure titanium mesh 11, and the cathode circuit is completed; connect the anode interface 15 to the hanger 2, and the anode circuit is completed; turn on the electrochemical polishing power system, set the voltage to a constant 60V, then set the current to 0.2-0.4A, the polishing time to 30-40s, and the polishing times to 6-8 times; Step 3, turn on the temperature control system 17, set the polishing temperature to -5°C-5°C, and wait until the temperature drops to the set temperature; Step 4, use the clamp 3 to clamp the bracket 5, and then lock the clamp 3 in the middle of the hanger 2 through the locking nut, control the downward movement of the hanger 2 through the hanger lifting platform 16, and completely immerse the bracket 5 in the polishing liquid 13 (the main components of the polishing liquid are: acetic acid 10%-20%, perchloric acid 5%-10%, glycerol 20%-30%, etc., among which perchloric acid plays a major role in surface treatment, and adding an appropriate amount of acetic acid can slow down the polishing speed, and then adding an appropriate amount of glycerol helps brighten the surface of the bracket), until polishing is completed and enter ultrasonic cleaning.

[0004] The disadvantage of the prior art is that, since the bracket has a grid-like structure with narrow rod width and thin wall thickness, if the clamp cannot control the clamping of the bracket well, the bracket may be easily unevenly polished or over-polished and broken at the inflection point. Summary of the invention

[0005] The purpose of the present invention is to provide a nickel-titanium alloy intracranial stent electrochemical polishing device and method to solve the technical problems in the related art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A nickel-titanium alloy intracranial stent electrochemical polishing device comprises a polishing workbench and a lifting platform arranged on the polishing workbench, wherein a clamp is arranged on the lifting platform, and driven by the lifting platform, the clamp clamps the stent and enters the polishing liquid on the polishing workbench for electrochemical polishing treatment, wherein the clamp is made of an inert titanium material; the clamp comprises a central rod fixedly connected to the lifting platform, and a plurality of contact rods are evenly arranged in the circumference of the central rod, and a gap is provided between two contact rods at adjacent positions; when the nickel-titanium alloy intracranial stent is electrochemically polished, the stent is sleeved on the outer walls of the plurality of contact rods.

[0007] As mentioned above, the number of the contact rods is six, and they are arranged in a hexagonal manner in the circumferential direction of the central rod.

[0008] As mentioned above, the surface where the contact rod contacts the bracket is in an arc shape.

[0009] As mentioned above, both ends of the six contact rods along the axial direction of the central rod are in a conical structure.

[0010] As mentioned above, a base block is provided on the center rod along an axial sliding sleeve, and the contact rods are arranged on the base block for radial sliding along the center rod. An extrusion piece is provided on the center rod. When the center rod and the base block move relative to each other in the axial direction, the extrusion piece squeezes the six contact rods based on the power of the center rod to expand along their corresponding radial directions.

[0011] As mentioned above, the extrusion member includes six extrusion rods arranged in the circumferential direction of the center rod, and a first slideway is arranged on each contact rod. A slider is slidably provided in the first slideway, and each slider is connected to the corresponding extrusion rod, and the first slideway includes an inclined section and a straight section; in the sliding stroke of the slider from the inclined section in the direction close to the straight section, the contact rod moves in the direction away from the center rod to form an expansion clamping action on the bracket; in the moving stroke of the slider along the straight section, the six contact rods maintain the expansion clamping action on the bracket; in the sliding stroke of the slider from the straight section in the direction close to the inclined section, the six contact rods move in the direction close to the center rod to remove the expansion clamping action on the bracket.

[0012] As mentioned above, the extrusion rod is arranged to slide radially on the center rod, and the sliding direction is consistent with the sliding direction of the corresponding contact rod. In the sliding direction, a first elastic member is provided between the extrusion rod and the center rod. During the sliding stroke of the slider from the inclined section to the straight section, the elastic force of the first elastic member gradually increases to provide elastic force for the six contact rods to expand outward.

[0013] As mentioned above, the change in the elastic force of the first elastic member includes two strokes: in the first stroke, the elastic force of the first elastic member increases, providing the six contact rods with a force to expand and clamp the bracket, and this force causes the bracket to undergo elastic deformation; in the second stroke, the elastic force of the first elastic member continues to increase, and the force applied to the contact rod is not sufficient to cause the bracket to continue to undergo elastic deformation.

[0014] In the above-mentioned, in the axial direction, a second elastic member is provided between the center rod and the base block, when the slider is at one end of the straight section close to the inclined section, the gravity of the six contact rods is balanced by the elastic force of the second elastic member, and the six contact rods and the center rod remain in a relatively static state; when the slider is at one end of the straight section away from the inclined section, under the action of the rebound force of the second elastic member, the six contact rods overcome the action of gravity and move upward.

[0015] The present invention also relates to a nickel-titanium alloy intracranial stent chemical polishing method, wherein the nickel-titanium alloy intracranial stent is polished by the nickel-titanium alloy intracranial stent electrochemical polishing device described above, and the method comprises the following steps: Step 1: Clamp the bracket. Fix the center rod on the lifting platform, then sleeve the bracket on the six contact rods, push the six contact rods along the axial direction of the center rod to move, so as to drive each slider to enter the straight section along the corresponding inclined section, and the six contact rods expand radially away from the center rod to clamp the bracket; Step 2: Polishing of the bracket: the lifting platform drives the bracket through the clamp into the polishing liquid on the polishing workbench for electrochemical polishing.

[0016] The beneficial effects of the present invention are as follows: the clamp is made of inert titanium material, which has good electrical conductivity and corrosion resistance, does not participate in ion chemical reactions, and multiple contact rods are in multi-angle contact with the bracket. There is a gap between two adjacent contact rods, that is, multiple contact rods are hollowed out with the center rod to ensure that the bracket does not fall off during clamping. Compared with the traditional point clamping method, it solves the pain points of over-polishing or pitting at the clamping points of the bracket, and at the same time makes the polishing of various parts of the bracket more even, avoiding the generation of thick and thin rods of the bracket. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0018] Figure 1 A schematic diagram of the planar structure of an electrochemical polishing device for a nickel-titanium alloy intracranial stent in an embodiment provided by the present invention; Figure 2A schematic diagram of the three-dimensional structure of a fixture of an electrochemical polishing device for a nickel-titanium alloy intracranial stent in an embodiment provided by the present invention; Figure 3 A schematic diagram of the radial cross-sectional structure of a fixture of a nickel-titanium alloy intracranial stent electrochemical polishing device in an embodiment provided by the present invention; Figure 4 A schematic diagram of the axial cross-sectional structure of a fixture portion of an electrochemical polishing device for a nickel-titanium alloy intracranial stent in an embodiment provided by the present invention; Figure 5 A schematic diagram of the axial cross-sectional structure of another part of a fixture of a nickel-titanium alloy intracranial stent electrochemical polishing device in an embodiment provided by the present invention; Figure 6 for Figure 5 A is an enlarged structural diagram; Figure 7 A schematic diagram of the axial cross-sectional structure of a slider of a nickel-titanium alloy intracranial stent electrochemical polishing device in an embodiment provided by the present invention when the slider is in a straight line segment; Figure 8 for Figure 7 The enlarged structural diagram at B in FIG. Fig. 9 A schematic diagram of a planar structure of a comparison between a first slideway and a second slideway on two contact rods at adjacent positions of a nickel-titanium alloy intracranial stent electrochemical polishing device in an embodiment of the present invention; Fig.10 This is a schematic diagram of the planar structure comparison of the second slideways on two adjacent contact rods of a nickel-titanium alloy intracranial stent electrochemical polishing device in an embodiment provided by the present invention.

[0019] Description of reference numerals: 1. Polishing workbench; 10. Cooling water; 11. Pure titanium mesh; 12. Beaker; 13. Polishing liquid; 14. Cathode interface; 15. Anode interface; 16. Lifting platform; 17. Temperature control system; 2. Hanger; 3. Clamp; 30. Center rod; 31. Contact rod; 32. Base block; 33. Slide; 34. Extrusion rod; 35. First slide; 350. Inclined section; 351. Straight section; 36. Slider; 37. Second slide; 38. Locking rod; 39. Trigger block; 40. Unlocking rod; 41. Transition section; 5. Bracket. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solution of the present invention, Figure 1 To Attachment Fig.10 The present invention is further described in detail.

[0021] An embodiment provided by the present invention relates to an electrochemical polishing device for a nickel-titanium alloy intracranial stent 5, comprising a polishing workbench 1 and a lifting platform 16 arranged on the polishing workbench 1, wherein a clamp 3 is arranged on the lifting platform 16, and driven by the lifting platform 16, the clamp 3 clamps the stent 5 and enters the polishing liquid 13 on the polishing workbench 1 for electrochemical polishing treatment, wherein the clamp 3 is made of an inert titanium material; the clamp 3 comprises a central rod 30 fixedly connected to the lifting platform 16, and a plurality of contact rods 31 are evenly arranged in the circumferential direction of the central rod 30, and a gap is provided between two contact rods 31 at adjacent positions; when the nickel-titanium alloy intracranial stent 5 is electrochemically polished, the stent 5 is sleeved on the outer wall of the plurality of contact rods 31.

[0022] Specifically, the device for electrochemical polishing the nickel-titanium alloy intracranial stent 5 is mainly composed of an electrochemical polishing workstation power system, a polishing workbench 1 and an electrochemical polishing temperature control system. The overall production process of the stent 5 is: nickel-titanium tube cutting - cutting residue cleaning - ultrasonic cleaning - stent 5 preheating treatment - stent 5 shaping - stent 5 polishing; the polishing principle of the stent 5 is introduced in detail in the background technology, and will not be repeated here. The lifting platform 16 can be a screw transmission mechanism, which is a prior art and will not be repeated. The connection between the lifting platform 16 and the clamp 3 can be fixed by bolts. The lifting platform 16 drives the bracket 5 to move vertically through the clamp 3, that is, drives the bracket 5 to enter and exit the polishing liquid 13 vertically. In the prior art, since the bracket 5 has a grid-like structure with the characteristics of thin rod width and thin wall thickness, if the clamp 3 cannot control the clamping of the bracket 5 well, it is very easy for the bracket 5 to be unevenly polished or over-thrown and broken at the inflection point.

[0023] Therefore, in this embodiment, the clamp 3 is made into a structure supported from the inner wall of the bracket 5, that is, the clamp 3 is composed of a central rod 30 and a plurality of contact rods 31 arranged in the circumferential direction of the outer wall of the central rod 30, the central rod 30 is a long cylindrical structure, the radial cross-section of the contact rod 31 is a fan-shaped structure, the contact rod 31 is away from the side of the central rod 30, that is, the outer wall of the contact rod 31 contacts and clamps the inner wall of the support, and the two adjacent contact rods 31 are arranged at intervals, that is, the clamp 3 is a hollow structure as a whole, and the clamp 3 adopts an inertia structure as a whole. The advantage of such a design is that the clamp 3 is made of inert titanium material, which has good conductivity and corrosion resistance and does not participate in ion chemical reactions. Multiple contact rods 31 are in multi-angle contact with the bracket 5, and there is a gap between two adjacent contact rods 31, that is, multiple contact rods 31 cooperate with the center rod 30 to present a hollow design, which ensures that the bracket 5 does not fall off when clamped. Compared with the traditional point clamping method, it solves the pain point of over-polishing or pitting of the clamping point of the bracket 5, and at the same time makes the polishing of various parts of the bracket 5 more uniform, avoiding the generation of thick and thin rods of the bracket 5.

[0024] Preferably, the number of the contact rods 31 is six, and they are arranged in a hexagonal manner in the circumferential direction of the center rod 30; specifically, the six contact rods 31 are arranged in a hexagonal manner in the circumferential direction, which not only ensures sufficient contact area with the bracket 5, but also ensures that the gap between two adjacent contact rods 31 does not affect the electrochemical polishing operation of the bracket 5.

[0025] Preferably, the surface of the contact rod 31 in contact with the bracket 5 is arc-shaped; specifically, the outer wall of the contact rod 31 is arc-shaped, and when it contacts the inner wall of the bracket 5, it will not produce a bending indentation on the bracket 5, so as to ensure that the bracket 5 can be used normally.

[0026] Preferably, both ends of the six contact rods 31 along the axial direction of the central rod 30 are in a conical structure; specifically, the conical structure facilitates the bracket 5 to be quickly sleeved on the outer walls of the six contact rods 31 .

[0027] Furthermore, a base block 32 is provided on the center rod 30 along an axial sliding sleeve, and the contact rods 31 are arranged on the base block 32 to slide radially along the center rod 30. An extrusion piece is provided on the center rod 30. When the center rod 30 and the base block 32 move relative to each other in the axial direction, the extrusion piece extrudes the six contact rods 31 based on the power of the center rod 30 to expand along their respective corresponding radial directions.

[0028] Specifically, in the aforementioned embodiment, when electrochemical polishing is performed, the bracket 5 is directly sleeved on the outer walls of the six contact rods 31, and the friction between it and the outer walls of the contact rods 31 is used to ensure that it will not fall off during polishing. However, this friction force will hinder the bracket 5 from being sleeved on the six contact rods 31, and will also hinder the bracket 5 from being removed from the six contact rods 31 after polishing is completed.

[0029] Therefore, in this embodiment, the six contact rods 31 are configured as a movable structure, and the six contact rods 31 are all arranged to slide along their respective corresponding radial directions on the base block 32, that is, a slide groove 33 corresponding to each contact rod 31 is arranged on the circumference of the base block 32, and a part of each contact rod 31 is arranged to slide in the corresponding slide groove 33, and then when the axial relative movement occurs between the central rod 30 and the base block 32, the extrusion piece is used to control the six contact rods 31 to expand and contract, so that the bracket 5 can be taken and placed.

[0030] In a preferred embodiment, the extrusion member includes six extrusion rods 34 arranged in the circumferential direction of the central rod 30, each contact rod 31 is arranged with a first slide 35, a slider 36 is slidably arranged in the first slide 35, the slider 36 can only slide along its track in the first slide 35, the slider 36 cannot be separated from the first slide 35 in other directions, the depth direction of the first slide 35 is consistent with the sliding direction of the corresponding contact rod 31 on the base block 32, each slider 36 is connected to the corresponding extrusion rod 34, and the first slide 35 includes an inclined section 350 and a straight section 351, the depth of the straight section 351 is kept on its track The six contact rods 31 maintain the expansion and clamping action on the bracket 5. The end of the inclined section 350 away from the straight section 351 is deeper than the end close to the straight section 351; during the sliding stroke of the slider 36 from the inclined section 350 to the direction close to the straight section 351, the contact rod 31 moves in the direction away from the center rod 30, forming an expansion and clamping action on the bracket 5; during the moving stroke of the slider 36 along the straight section 351, the six contact rods 31 maintain the expansion and clamping action on the bracket 5; during the sliding stroke of the slider 36 from the straight section 351 to the direction close to the inclined section 350, the six contact rods 31 move in the direction close to the center rod 30, and the expansion and clamping action on the bracket 5 is withdrawn.

[0031] Before operation, the six contact rods 31 are pressed against the center rod 30 along their respective corresponding radial directions. During operation, the bracket 5 is first sleeved on the outer walls of the six contact rods 31. At this time, the bracket 5 has not yet contacted the outer walls of the six contact rods 31. Then, the six contact rods 31 are pushed to move relative to the center rod 30. That is, when the six contact rods 31 are used as a reference, the center rod 30 extends from the middle of the six contact rods 31. The movement of the center rod 30 drives the six extrusion rods 34 to move together. Then, each extrusion rod 34 drives the correspondingly connected slider 36 to move along the inclined section 350 toward the straight section 351. In this embodiment, the length of the extrusion rod 34 cannot be extended or shortened, so the extrusion rod 34 and the inclined section 350 are wedge-shaped to form an extrusion action, so that each contact rod 31 moves toward the far end along its respective radial direction. Move in the direction away from the center rod 30, that is, the six contact rods 31 expand outward at the same time to internally support and clamp the bracket 5. After the slider 36 enters the straight section 351, there is no wedge-shaped matching structure between the extrusion rod 34 and the straight section 351, and no extrusion action can be formed. In this way, the six contact rods 31 maintain a stable internal support and clamping of the bracket 5. On the contrary, when the slider 36 enters the inclined section 350 from the straight section 351, the wedge-shaped matching between the extrusion rod 34 and the corresponding inclined section 350 no longer performs an extrusion action, but the extrusion rod 34 cooperates with the slider 36 to form a pulling action on the contact rod 31, so that the contact rod 31 approaches the center rod 30 radially. In this way, the six contact rods 31 will remove the internal support and clamping of the bracket 5, thereby facilitating the removal of the bracket 5 after polishing, and at the same time, it can perform internal support and clamping corresponding to brackets 5 of different radial sizes.

[0032] In an optional embodiment, the extrusion rod 34 is arranged to slide radially on the center rod 30, and the sliding direction is consistent with the sliding direction of the corresponding contact rod 31. In the sliding direction, a first elastic member is provided between the extrusion rod 34 and the center rod 30. During the sliding stroke of the slider 36 along the inclined section 350 toward the straight section 351, the elastic force of the first elastic member gradually increases to provide an elastic force for the six contact rods 31 to expand outward.

[0033] Specifically, in the aforementioned embodiment, the internal support clamping of the bracket 5 is realized by the expansion of the six contact rods 31. When the extrusion rod 34 drives the slider 36 to slide along the inclined section 350 toward the direction close to the straight section 351, as the distance between the slider 36 and the straight section 351 becomes closer and closer, the extrusion force given to the contact rod 31 by the extrusion rod 34 becomes greater and greater, and the internal support force of the contact rod 31 on the bracket 5 is also gradually increased. If the strength of the internal support clamping cannot be properly controlled, there is a risk of the internal support damaging the bracket 5. In order to maintain the six contact rods 31 on the bracket In order to maintain the stability of the inner support clamping of 5, the slider 36 must reach the straight section 351. Therefore, in order to avoid damaging the bracket 5, in this embodiment, the extrusion rod 34 is arranged on the center rod 30 along the radial sliding direction, and the sliding direction is consistent with the sliding direction of the corresponding contact rod 31, and each extrusion rod 34 is provided with a first elastic member between it and the center rod 30 in the sliding direction. By utilizing the elastic force of the first elastic member, a flexible extrusion force is generated between the extrusion rod 34 and the contact rod 31, thereby providing a certain protection for the bracket 5 when the inner support clamps the bracket 5.

[0034] In another optional embodiment, the change in the elastic force of the first elastic member includes two strokes: in the first stroke, the elastic force of the first elastic member increases, providing the six contact rods 31 with a force to expand and clamp the bracket 5, and this force causes the bracket 5 to undergo elastic deformation; in the second stroke, the elastic force of the first elastic member continues to increase, and the force applied to the contact rods 31 is insufficient to cause the bracket 5 to continue to undergo elastic deformation.

[0035] Specifically, in the aforementioned embodiment, the elastic force of the first elastic member is used to generate a flexible squeezing force between the squeezing rod 34 and the contact rod 31, so that when the bracket 5 is internally supported and clamped, the bracket 5 is protected to a certain extent. However, as the elastic force of the first elastic member gradually increases, the contact rod 31 also has a greater internal supporting effect on the bracket 5, and there is a certain probability that the bracket 5 will be damaged. Therefore, in this embodiment, the elastic force of the first elastic member should first provide sufficient force for the six contact rods 31 to internally support and clamp the bracket 5 during the process of increasing. At this time, the elastic force of the first elastic member makes the positive pressure between the contact rod 31 and the bracket 5 just enough to maintain the bracket 5 from being damaged. The contact rod 31 moves axially along the upper side (corresponding to the first stroke), and in the process of the elastic force of the first elastic member increasing thereafter, the six contact rods 31 can continue to expand outward until the slider 36 enters the straight section 351. The expansion of the six contact rods 31 can cause the bracket 5 to produce a certain elastic deformation, but the elastic deformation is within the normal range of its elastic change degree. For example, the elastic deformation of the bracket 5 is 1, and the maximum deformation of the first elastic member is 0.9, that is, the maximum elastic force generated by the first elastic member is insufficient to cause the bracket 5 to continue to undergo elastic deformation after the elastic deformation reaches 1 (corresponding to the second stroke). In this way, the bracket 5 can be protected during the process of being clamped by the inner support.

[0036] Furthermore, in the axial direction, a second elastic member is provided between the center rod 30 and the base block 32. When the slider 36 is at one end of the straight section 351 close to the inclined section 350, the gravity of the six contact rods 31 is balanced with the elastic force of the second elastic member, and the six contact rods 31 and the center rod 30 remain in a relatively static state; when the slider 36 is at one end of the straight section 351 away from the inclined section 350, under the action of the rebound force of the second elastic member, the six contact rods 31 overcome the action of gravity and move upward.

[0037] Specifically, during the electrochemical polishing of the bracket 5, the movement of the bracket 5 can have a certain impact on the polishing effect: first, the movement of the bracket 5 can help achieve a uniform distribution of the polishing liquid 13 to improve the uniformity of polishing and reduce the risk of local over-polishing or pitting; second, the movement of the bracket 5 can help remove bubbles generated during the polishing process to ensure that the polishing liquid 13 is in good contact with the surface of the bracket 5; third, appropriate movement of the bracket 5 can increase the uniformity of the current density, thereby improving the polishing efficiency; the movement of the bracket 5 can be rotation, vibration or linear motion, wherein when performing linear motion, the speed needs to be adjusted according to the characteristics of the polishing liquid 13 and the material, too fast may lead to uneven polishing, and too slow may reduce the fall, so in this embodiment, a second elastic member is set between the center rod 30 and the base block 32, to ensure that the six contact rods 31 can stably clamp the bracket 5, then on the slider When 36 is at one end of the straight section 351 close to the inclined section 350, the gravity of the six contact rods 31 is balanced by the elastic force of the second elastic member, and the six contact rods 31 and the center rod 30 remain in a relatively static state. At this time, when the bracket 5 is polished, the bracket 5 will not make linear movement in the polishing liquid 13. When the slider 36 moves to the other end in the straight section 351 in a direction away from the inclined section 350, if there is no external force continuing to act on the six contact rods 31 and the center rod 30 to move relative to each other, at this time, the rebound force of the second elastic member is greater than the gravity of the six contact rods 31. Then, under the action of the rebound force of the second elastic member, the six contact rods 31 move axially, driving the bracket 5 to make linear movement in the polishing liquid 13. The moving speed of the six contact rods 31 can be adjusted according to the actual situation, its gravity and the manufacturing specifications of the second elastic member, so as to ensure the uniformity of the polishing of the bracket 5 and the polishing efficiency.

[0038] In another embodiment provided by the present invention, a second slideway 37 is further provided on each contact rod 31, one end of the second slideway 37 is connected to the inclined section 350, and the other end is connected to the straight section 351, the second slideway 37 is wavy, and in the radial direction of the center rod 30, the trough of the second slideway 37 is farther away from the center rod 30 than the crest, so that when the slider 36 is at the crest position, the corresponding contact rod 31 contacts the inner wall of the bracket 5, and when the slider 36 is at the trough position, the contact rod 31 contracts inwardly close to the center rod 30 and no longer contacts the inner wall of the bracket 5, so that the six contact rods 31 are evenly divided into two groups, and each group of three contact rods 31 is arranged at intervals in the circumferential direction with the other group of three contact rods 31, then the crest positions and trough positions of the two second slideways 37 on the two contact rods 31 at adjacent positions should be staggered, for ease of description, the six contact rods 31 are named J1, J2, J3, J4, J5, and J6 in the clockwise direction, that is, J1, J3 and J5 are a group, and the three second slideways 37 are arranged in the same way. J2, J4 and J6 are a group, and the three second slideways 37 are arranged in the same way. The crest of J1 corresponds to the trough of J2, and the crest of J2 corresponds to the trough of J1. When J1, J3 and J5 are about to break away from the inner support clamping of the bracket 5, J2, J4 and J6 need to inner support clamping the bracket 5, that is, the crest of J1 should partially overlap with the crest of J2, and the crest of J2 should partially overlap with the crest of J6. 3 partially overlaps, and by analogy, the wave crests of J6 and J1 also partially overlap, so that after the slider 36 enters the second slideway 37 from the straight section 351, the six contact rods 31 drive the bracket 5 to move linearly based on the rebound of the second elastic member, and the two groups of contact rods 31 can alternately support and clamp the bracket 5, so that all parts of the inner wall of the bracket 5 can contact with the polishing liquid 13, thereby ensuring the comprehensiveness and uniformity of the polishing of the inner wall of the bracket 5.

[0039] In the above, during the movement of the slider 36 in the second slideway 37, the length of the extrusion rod 34 should not change, so that the two contact rods 31 can cooperate with the second slideway 37 to alternately support and clamp the bracket 5, that is, a locking structure is set at the connection between each extrusion rod 34 and the center rod 30, and the locking structure includes two locking rods 38 symmetrically arranged in the sliding space of each extrusion rod 34, and the locking rods 38 are swingably arranged on the center rod 30. A trigger block 39 is provided between the swing axes of the two locking rods 38 to slide along the sliding direction of the extrusion rod 34. The trigger block 39 is in frictional contact with the two locking rods 38, and a third elastic member is provided between the trigger block 39 and the center rod 30 in the sliding direction. Based on the third elastic member, Under the elastic force of the third elastic member, the ends of the two locking rods 38 away from their respective swing axes tend to approach each other, and the end of each locking rod 38 away from the swing axis contacts the side of the corresponding extrusion rod 34. When the slider 36 has not reached the straight section 351, due to the limitation of the extrusion rod 34, the ends of the two locking rods 38 away from their respective swing axes cannot approach each other under the elastic force of the third elastic member. When the slider 36 reaches the straight section 351, the extrusion rod 34 restricts the contact of the locking rod 38, and then under the elastic force of the third elastic member, the ends of the two locking rods 38 away from their respective swing axes approach each other to lock the extrusion rod 34, that is, the extrusion rod 34 has a T-shaped structure. When the slider 36 is in the straight section 351, away from One end of the slider 36 is restricted by two locking rods 38 in its sliding direction, so that the extrusion rod 34 cannot move away from the center rod 30 in the sliding direction under the action of the rebound force of the first elastic member, thereby achieving the locking of the extrusion rod 34. After the polishing of the bracket 5 is completed, when the bracket 5 needs to be removed from the six contact rods 31, the extrusion rod 34 is required to drive the slider 36 to enter the inclined section 350. In this way, the locking of the extrusion rod 34 needs to be contacted, that is, an unlocking rod 40 is provided inside the center rod 30 along the axial sliding. The end of the unlocking rod 40 close to the bracket 5 always rests against the center rod 30 when the slider 36 enters the straight section 351 from the inclined section 350 and enters the second slideway 37 from the straight section 351. When the squeezing rod 34 needs to be unlocked, the unlocking rod 40 is pushed in the direction away from the bracket 5. The unlocking rod 40 and each trigger block 39 are wedge-shaped to form an squeezing action. The movement of the trigger block 39 causes the two corresponding locking rods 38 to swing relative to each other, that is, the two locking rods 38 are away from their respective swinging axes. The ends move away from each other to contact and lock the squeezing rod 34. In this way, the squeezing rod 34 drives the slider 36 and the second slide 37 to enter the inclined section 350. During this process, the six contact rods 31 can shrink inward to remove the inner support clamping of the bracket 5, wherein a transition section 41 is provided between the second slide 37 and the inclined section 350, and the inclination angle of the transition section 41 is consistent with the inclination angle of the inclined section 350.

[0040] Another embodiment provided by the present invention relates to a method for chemical polishing of a nickel-titanium alloy intracranial stent 5, wherein the method for polishing the nickel-titanium alloy intracranial stent 5 by the above-mentioned nickel-titanium alloy intracranial stent 5 electrochemical polishing device comprises the following steps: Step 1: Clamping the bracket 5, fix the center rod 30 on the lifting platform 16, then sleeve the bracket 5 on the six contact rods 31, push the six contact rods 31 along the axial direction of the center rod 30 to move, so as to drive each slider 36 to enter the straight section 351 along the corresponding inclined section 350, and the six contact rods 31 expand in the radial direction away from the center rod 30 to clamp the bracket 5; Step 2: Polishing of the bracket 5: the lifting platform 16 drives the bracket 5 through the clamp 3 to enter the polishing liquid 13 on the polishing workbench 1 for electrochemical polishing.

[0041] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. An electrochemical polishing device for a nickel-titanium alloy intracranial stent, comprising a polishing workbench and a lifting platform arranged on the polishing workbench, wherein a clamp is arranged on the lifting platform, and driven by the lifting platform, the clamp clamps the stent into the polishing liquid on the polishing workbench for electrochemical polishing treatment, characterized in that: The fixture is made of an inert titanium material; The fixture includes a central rod fixedly connected to the lifting platform, a plurality of contact rods evenly arranged circumferentially of the central rod, and a gap between two contact rods at adjacent positions; when electrochemical polishing is performed on the nickel-titanium alloy intracranial stent, the stent is sleeved on the outer walls of the plurality of contact rods.

2. The electrochemical polishing device for nickel-titanium alloy intracranial stent according to claim 1, characterized in that: The number of the contact rods is six, and they are arranged in a hexagonal pattern in the circumferential direction of the central rod.

3. The electrochemical polishing device for nickel-titanium alloy intracranial stent according to claim 2, characterized in that: The surface of the contact rod in contact with the bracket is in an arc shape.

4. The electrochemical polishing device for nickel-titanium alloy intracranial stent according to claim 2, characterized in that: Both ends of the six contact rods along the axis of the central rod are in a conical structure.

5. The electrochemical polishing device for nickel-titanium alloy intracranial stent according to claim 2, characterized in that: A base block is provided on the center rod along an axial sliding sleeve, and the contact rods are arranged on the base block for radial sliding along the center rod. An extrusion piece is provided on the center rod. When the center rod and the base block move relative to each other in the axial direction, the extrusion piece squeezes the six contact rods to expand along their respective corresponding radial directions based on the power of the center rod.

6. The electrochemical polishing device for nickel-titanium alloy intracranial stent according to claim 5, characterized in that: The extrusion member includes six extrusion rods arranged in the circumferential direction of the central rod, each contact rod is arranged with a first slideway, a slider is slidably arranged in the first slideway, each slider is connected to the corresponding extrusion rod, and the first slideway includes an inclined section and a straight section; When the slider slides from the inclined section to the direction close to the straight section, the contact rod moves in the direction away from the center rod, thereby forming an expansion and clamping action for the bracket; When the slider moves along the straight line, the six contact rods maintain the expansion and clamping action on the bracket; During the sliding stroke of the slider from the straight section to the direction close to the inclined section, the six contact rods move in the direction close to the center rod to remove the expansion clamping action on the bracket.

7. The electrochemical polishing device for nickel-titanium alloy intracranial stent according to claim 6, characterized in that: The extrusion rod is arranged to slide radially on the center rod, and the sliding direction is consistent with the sliding direction of the corresponding contact rod. In the sliding direction, a first elastic member is provided between the extrusion rod and the center rod. During the sliding stroke of the slider from the inclined section to the straight section, the elastic force of the first elastic member gradually increases to provide elastic force for the six contact rods to expand outward.

8. The electrochemical polishing device for nickel-titanium alloy intracranial stent according to claim 7, characterized in that: The elastic force change of the first elastic member includes two strokes: In the first stroke, the elastic force of the first elastic member increases, providing the six contact rods with a force to expand and clamp the bracket, and the force causes the bracket to undergo elastic deformation; In the second stroke, the elastic force of the first elastic member continues to increase, and the force applied to the contact rod is not sufficient to cause the bracket to continue to elastically deform.

9. The electrochemical polishing device for nickel-titanium alloy intracranial stent according to claim 6, characterized in that: In the axial direction, a second elastic member is provided between the center rod and the base block. When the slider is at one end of the straight section close to the inclined section, the gravity of the six contact rods is balanced by the elastic force of the second elastic member, and the six contact rods and the center rod remain in a relatively static state; when the slider is at one end of the straight section away from the inclined section, under the action of the rebound force of the second elastic member, the six contact rods overcome the effect of gravity and move upward.

10. A method for chemical polishing of a nickel-titanium alloy intracranial stent, based on the nickel-titanium alloy intracranial stent electrochemical polishing device according to any one of claims 1 to 9, characterized in that: The chemical polishing method of the nickel-titanium alloy intracranial stent comprises the following steps: The bracket is clamped, the center rod is fixed on the lifting platform, and then the bracket is sleeved on the six contact rods, and the six contact rods are pushed to move along the axial direction of the center rod to drive each slider to enter the straight section along the corresponding inclined section, and the six contact rods expand radially away from the center rod to clamp the bracket; The bracket is polished, and the lifting platform drives the bracket through the clamp into the polishing liquid on the polishing workbench for electrochemical polishing.

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