High sealing long life balloon forming machine clamp

Abstract

The application relates to the field of medical devices and discloses a high-sealing long-service-life balloon forming machine clamp, which comprises a clamp base, a copper nut cover cylinder fixedly connected to one side of the clamp base, a metal shrinkable clamp sleeve coaxially arranged in the copper nut cover cylinder, a balloon tube mounting hole penetratingly arranged at the shaft center of the metal shrinkable clamp sleeve, a tight shrinkable part arranged at one end of the metal shrinkable clamp sleeve in the copper nut cover cylinder, a hollow shaft air cylinder fixedly connected to the other side of the clamp base, the hollow shaft air cylinder being a hollow through structure and serving as an axial driving force source and forming a high-pressure nitrogen gas channel, a gas needle fixedly connected to the other end of the push rod of the hollow shaft air cylinder and extending into the copper nut cover cylinder, and a clamp seat slidingly arranged in the copper nut cover cylinder and provided with an extrusion groove matched with the tight shrinkable part at one end. Compared with the prior art, the balloon forming machine clamp has the advantages of high structural integration, separation of sealing and clamping functions, long service life of sealing parts and large clamping force.

Description

Technical Field

[0001] This invention relates to the field of medical device processing equipment technology, specifically to a high-sealing, long-life balloon molding machine fixture. Background Technology

[0002] In the blow molding process of interventional medical devices (such as angioplasty balloons and stent delivery system balloons), the balloon tube needs to be axially stretched and radially inflated under high-pressure nitrogen. To ensure molding quality, the fixture must simultaneously meet three core requirements: first, it must provide a stable high-pressure seal inside the balloon tube to prevent high-pressure nitrogen leakage from causing molding pressure fluctuations; second, it must provide sufficient lateral clamping force to the outer wall of the balloon tube to prevent displacement or detachment during axial stretching; and third, the drive mechanism and the high-pressure gas path should be integrated as much as possible to shorten the gas path and reduce leakage points.

[0003] In existing technologies, balloon formation machine clamps generally use compressed O-rings to achieve both sealing and clamping functions, relying on the elastic deformation of the O-rings to both tighten the outer wall of the balloon tube and prevent gas leakage. This approach has the following technical drawbacks in actual production:

[0004] (1) Short lifespan of seals and high cost of consumables: O-rings bear the sealing reaction force of high pressure gas and the axial friction force (i.e. radial tensile force) when the balloon tube is stretched. Under alternating loads, they are prone to wear, aging and permanent deformation, requiring frequent shutdowns for replacement, which greatly increases the cost of consumables and equipment downtime.

[0005] (2) Insufficient clamping force, easy to pull out: The clamping force is limited by the radial elastic force of the elastomer (O-ring). During the molding process of large-diameter, long-specification balloons, the axial tensile force on the balloon tube increases significantly, and the balloon tube is very easy to be pulled out of the clamp, resulting in molding failure.

[0006] (3) Poor sealing reliability: After the O-ring wears out, the sealing performance drops sharply, and high-pressure nitrogen is easy to leak from the clamping point, resulting in unstable molding pressure, uneven balloon wall thickness, and low product yield. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the above-mentioned technical difficulties and provide a balloon forming machine fixture with a highly integrated structure, separation of sealing and clamping functions, long sealing life, and large clamping force.

[0008] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: a high-sealing, long-life balloon molding machine fixture, including a fixture base, a copper nut cover fixedly connected to one side of the fixture base, a metal shrinkage sleeve coaxially arranged inside the copper nut cover, a balloon tube mounting hole arranged through the axial center of the metal shrinkage sleeve, and a clamping shrinkage part located at one end of the metal shrinkage sleeve inside the copper nut cover; a hollow shaft cylinder fixedly connected to the other side of the fixture base, the hollow shaft cylinder having a hollow through structure, serving as both an axial driving force source and a high-pressure nitrogen channel; a push rod of the hollow shaft cylinder extending into the copper nut cover and fixedly connected to one end of a gas needle, the internal channel of the gas needle coaxially communicating with the hollow channel of the hollow shaft cylinder; a fixture seat slidably arranged inside the copper nut cover, one end of the fixture seat having an extrusion groove that mates with the clamping shrinkage part, a through hole that mates with the gas needle located at the axial center of the fixture seat, and an O-ring fixedly connected to the other end of the fixture seat.

[0009] As an improvement, the clamping and shrinking part includes a conical sleeve fixedly connected to one end of the metal shrinking sleeve. One end of the conical sleeve is provided with at least one through groove along the circumferential direction, dividing the conical sleeve into multiple elastic claws. The squeezing groove is a conical groove.

[0010] As an improvement, a cylindrical groove communicating with the extrusion groove is provided at the center of the inner shaft of the fixture seat, and a cylindrical sealing ring is fixedly inserted into the cylindrical groove.

[0011] As an improvement, metal gaskets that mate with the cylindrical sealing ring are fixedly connected to both ends of the cylindrical groove.

[0012] As an improvement, the cylindrical ring is made of silicone, rubber, or polyurethane elastomer.

[0013] As an improvement, the fixture base is provided with an internal thread, which is connected to the external thread of the copper nut cover.

[0014] As an improvement, the hollow shaft cylinder is fixedly connected to one side of the fixture base by cylinder fixing bolts.

[0015] As an improvement, a metal threaded connector is fixedly connected between the hollow shaft cylinder and the air needle.

[0016] As an improvement, a steel ferrule is fixedly connected to the shaft center of one end of the copper nut cover, and a metal shrink sleeve is fixedly connected inside the steel ferrule.

[0017] The advantages of this invention compared to the prior art are:

[0018] The sealing and clamping functions are separated. O-rings and cylindrical seals are dedicated to sealing, while the metal shrink jacket is dedicated to clamping, with a clear division of labor. The seals no longer bear the clamping tension, and the metal jacket provides rigid, high-tension clamping force, which can meet the molding requirements of large-size, high-tensile-force balloons. The seals are only subjected to axial compression and not radial tension, significantly reducing wear, deformation, and failure probability, greatly extending service life, and reducing the frequency of consumable replacement and equipment downtime. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the fixture structure for a high-sealing, long-life balloon molding machine according to the present invention.

[0020] Figure 2 This is an exploded view of a high-sealing, long-life balloon molding machine fixture according to the present invention.

[0021] Figure 3 This is a schematic diagram of the copper nut cover and its connection structure of a high-sealing, long-life balloon forming machine clamp according to the present invention.

[0022] Figure 4 This is a schematic diagram of the usage state of a high-sealing, long-life balloon forming machine fixture according to the present invention.

[0023] As shown in the figure: 1. Fixture base; 2. Hollow shaft cylinder; 3. Copper nut cover; 4. Metal shrink sleeve; 5. Fixture seat; 6. Cylindrical seal ring; 7. O-ring seal ring; 8. Extrusion groove; 9. Metal washer; 10. Air needle; 11. Cylinder fixing bolt; 12. Metal threaded connector. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] like Figures 1 to 4 As shown, this invention proposes a high-sealing, long-life balloon forming machine fixture, which mainly consists of a hollow shaft cylinder 2, a metal threaded connector 12, a fixture base 1, an air needle 10, an O-ring seal 7, a fixture seat 5, a metal washer 9, a cylindrical seal 6, a metal shrink sleeve 4, a steel ferrule, a copper nut cover 3, and a retaining ring.

[0026] The copper nut cover 3 is connected to the internal thread on one side of the clamp base 1 via an external thread, forming a detachable modular structure for easy maintenance. A steel ferrule is fixedly connected to the end of the copper nut cover 3 furthest from the clamp base 1. A metal shrink sleeve 4 is coaxially arranged within the steel ferrule, and a retaining ring is positioned within the annular groove of the copper nut cover 3 to axially limit the metal shrink sleeve 4 and prevent it from falling off before clamping. The metal shrink sleeve 4, steel ferrule, copper nut cover 3, and retaining ring together constitute the clamping end assembly.

[0027] The metal shrink-fit sleeve 4 is made of stainless steel, possessing high rigidity and strength, and does not undergo plastic deformation while providing a large clamping force. A through-hole for the balloon tube is provided at the axial center of the metal shrink-fit sleeve 4. One end of the metal shrink-fit sleeve 4, located inside the copper nut cover 3, has a clamping shrink-fit section, which includes a conical sleeve with a preferred cone angle of 30°–60°. The conical sleeve has uniformly spaced grooves along its circumference, dividing it into multiple elastic claws. The root of each elastic claw is connected to the body of the metal shrink-fit sleeve 4, with a free end at the front. When the conical sleeve is subjected to axial compressive force, each elastic claw elastically contracts radially inward, clamping the outer wall of the balloon tube.

[0028] The clamp seat 5 is slidably disposed inside the copper nut cover 3. A conical extrusion groove 8 is provided at one end of the clamp seat 5 near the metal shrinkage sleeve 4, and the conical surface of the conical extrusion groove 8 mates with the outer conical surface of the conical sleeve. A through hole is provided at the axial center of the clamp seat 5, which slidably engages with the air needle 10, serving both as a guide and allowing high-pressure nitrogen gas to pass through. When the clamp seat 5 moves axially under the push of the push rod of the hollow shaft cylinder 2, the conical surface of the conical extrusion groove 8 presses against the elastic claw of the conical sleeve, causing it to contract radially, achieving strong clamping.

[0029] An O-ring seal 7 is provided at the end of the clamp seat 5 away from the conical extrusion groove 8, that is, at the end near the hollow shaft cylinder 2. A cylindrical groove communicating with the conical extrusion groove 8 is also provided at the axial center of the clamp seat 5, and a cylindrical seal 6 is installed in the cylindrical groove. A metal washer 9 is provided at each end of the cylindrical groove, and the two metal washers 9 clamp the cylindrical seal 6 to limit the axial deformation space of the cylindrical seal 6.

[0030] The cylindrical sealing ring 6 is made of polyurethane elastic material, which has excellent wear resistance, pressure resistance and elastic recovery ability; the O-ring 7 can be made of nitrile rubber or fluororubber, which is resistant to high-pressure nitrogen corrosion. The metal gasket 9 is made of stainless steel or copper alloy with a smooth surface to reduce shear damage to the cylindrical sealing ring 6.

[0031] In operation, the clamp seat 5 axially compresses the O-ring 7 and the metal washer 9, with the metal washer 9 transmitting the axial force to the cylindrical sealing ring 6. Due to the constraint of the metal washer 9 and the sidewall of the cylindrical groove, the O-ring 7 and the cylindrical sealing ring 6 mainly undergo radial inward deformation under the axial compressive force, i.e., inner diameter contraction, thereby tightly gripping the outer wall of the air needle 10 and the outer wall of the balloon tube, forming a reliable high-pressure seal. During this process, the O-ring 7 and the cylindrical sealing ring 6 only bear the axial compressive force and not the radial tensile force during balloon tube stretching, thus resulting in minimal wear and a significantly extended service life.

[0032] The hollow shaft cylinder 2 has a hollow, through-hole structure, with a through-hole channel at the center of its cylinder body or piston rod. This hollow channel serves both as the intake channel for high-pressure nitrogen and as the axial driving force provided by the piston movement, achieving integrated driving and ventilation. The other side of the clamp base 1 is connected to the hollow shaft cylinder 2 via a metal threaded connector 12, and the hollow shaft cylinder 2 is fixed to the clamp base 1 using cylinder fixing bolts 11. The air needle 10 is fixedly installed in the central hole of the clamp base 1, and the internal channel of the air needle 10 is coaxially connected with the central through hole of the metal threaded connector 12 and the hollow channel of the hollow shaft cylinder 2. High-pressure nitrogen enters from the intake port of the hollow shaft cylinder 2, passes sequentially through the hollow channel, the central through hole of the metal threaded connector 12, and the internal channel of the air needle 10, and directly enters the balloon tube. The air path is extremely short, with few joints, and the risk of leakage is low.

[0033] Work process

[0034] The working process of the balloon forming machine fixture of the present invention is as follows:

[0035] Step 1: Install the balloon catheter

[0036] The balloon tube is threaded onto the air needle 10, so that the front end of the balloon tube passes sequentially through the balloon tube mounting hole of the metal shrink sleeve 4, the metal washer 9, and the cylindrical sealing ring 6. At this time, the clamp seat 5 is in the initial position, the elastic claws of the metal shrink sleeve 4 are in a naturally open state, and the balloon tube can be easily inserted.

[0037] Step 2: Cylinder Drive

[0038] Air is supplied to the hollow shaft cylinder 2, the push rod extends and pushes the clamp seat 5 to slide axially toward the outlet end of the copper nut cover 3.

[0039] Step 3: Rigid clamping

[0040] The conical extrusion groove 8 of the clamp seat 5 axially compresses the conical sleeve of the metal contraction sleeve 4, causing each elastic claw to contract radially inward and grip the outer wall of the balloon tube. Since the metal contraction sleeve 4 is a rigid stainless steel component, it can provide a clamping force much greater than that of a traditional O-ring, effectively preventing the balloon tube from being pulled out during subsequent stretching.

[0041] Step 4: High-pressure sealing

[0042] As the clamp seat 5 moves axially, its other end axially compresses the O-ring 7 and transmits the axial force to the cylindrical sealing ring 6 through the metal washer 9. Under the constraint of the metal washer 9 and the cylindrical groove, the inner diameters of the O-ring 7 and the cylindrical sealing ring 6 shrink, tightly fitting against the outer wall of the air needle 10 and the outer wall of the balloon tube, forming a high-pressure seal to prevent nitrogen leakage during the subsequent inflation process.

[0043] Step 5: Blow molding

[0044] High-pressure nitrogen gas enters through the hollow channel of the hollow shaft cylinder 2 and flows directly into the balloon tube through the internal channel of the air needle 10. Due to reliable sealing and stable forming pressure, the balloon tube is radially inflated while being stretched axially, ultimately forming a balloon that meets the requirements.

[0045] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0046] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0047] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A high-sealing, long-life balloon molding machine fixture, comprising a fixture base (1), characterized in that: A copper nut cover (3) is fixedly connected to one side of the clamp base (1). A metal shrink sleeve (4) is coaxially arranged inside the copper nut cover (3). A balloon tube mounting hole is provided through the center of the sleeve. A clamping shrink part is provided at one end of the metal shrink sleeve (4) inside the copper nut cover (3). A hollow shaft cylinder (2) is fixedly connected to the other side of the clamp base (1). The hollow shaft cylinder (2) is a hollow through structure, which serves as both an axial driving force source and a high-pressure nitrogen channel. The push rod of the hollow shaft cylinder (2) extends into the copper nut cover (3) and is fixedly connected to one end of an air needle (10). The internal channel of the air needle (10) is coaxially connected to the hollow channel of the hollow shaft cylinder (2). A clamp seat (5) is slidably provided inside the copper nut cover (3). One end of the clamp seat (5) is provided with an extrusion groove (8) that cooperates with the clamping and shrinking part. The clamp seat (5) is provided with a through hole at the axial center that cooperates with the air needle (10). An O-ring (7) is fixedly connected to the other end of the clamp seat (5).

2. The high-sealing, long-life balloon molding machine fixture according to claim 1, characterized in that: The clamping and shrinking part includes a conical sleeve fixedly connected to one end of the metal shrinking sleeve (4). One end of the conical sleeve is provided with at least one through groove along the circumferential direction, dividing the conical sleeve into multiple elastic claws. The squeezing groove (8) is a conical groove.

3. The high-sealing, long-life balloon molding machine fixture according to claim 1, characterized in that: The clamp seat (5) has a cylindrical groove at its inner axis that communicates with the extrusion groove (8), and a cylindrical sealing ring (6) is fixedly inserted into the cylindrical groove.

4. The high-sealing, long-life balloon molding machine fixture according to claim 3, characterized in that: Metal gaskets (9) that mate with the cylindrical sealing ring (6) are fixedly connected at both ends inside the cylindrical groove.

5. The high-sealing, long-life balloon molding machine fixture according to claim 3, characterized in that: The cylindrical ring is made of silicone, rubber, or polyurethane elastomer.

6. The high-sealing, long-life balloon molding machine fixture according to claim 1, characterized in that: The clamp base (1) is provided with an internal thread, which is connected to the external thread of the copper nut cover (3).

7. The high-sealing, long-life balloon molding machine fixture according to claim 1, characterized in that: The hollow shaft cylinder (2) is fixedly connected to one side of the clamp base (1) by cylinder fixing bolts (11).

8. The high-sealing, long-life balloon molding machine fixture according to claim 1, characterized in that: A metal threaded connector (12) is fixedly connected between the hollow shaft cylinder (2) and the air needle (10).

9. A high-sealing, long-life balloon molding machine fixture according to claim 1, characterized in that: A steel sleeve is fixedly connected to one end of the copper nut cover (3), and a metal shrink sleeve (4) is fixedly connected inside the steel sleeve.

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