Ceramic endoscope grasping forceps head and integrated forming method thereof

Abstract

The invention discloses an integrated forming method of a ceramic endoscope grasping forceps head. The method comprises the following steps: taking zirconium oxide model ink and water-soluble supporting ink as raw materials, and constructing an integral green body comprising an upper jaw, a lower jaw, a rotating shaft, a connecting pipe and a threaded sheath head layer by layer through material injection molding; the tooth-shaped meshing area, the hollow key groove and the movable gap are mixed, filled and supported according to a specific proportion, and a spiral hob is adopted for on-line milling after every 2-5 layers, so that the size precision is guaranteed. The green body is washed with water, dried and sintered at 1550 DEG C, the ceramic tong head with the density larger than or equal to 99.9%, the Ra being 3-4 microns and the bending strength larger than or equal to 800 MPa is prepared, and subsequent machining or riveting is not needed. The closed width of the product is smaller than or equal to 10 mm, the total length is smaller than or equal to 50 mm, the crocodile-shaped cambered surface and the 32-tooth R0.1 mm chamfer cooperate with the hollowed-out key groove and the oval drainage hole, light weight, low damage and high clamping force are achieved, the product can smoothly pass through an endoscope channel with the diameter being 2.0 mm, the disposable use requirement is met, and the problems that a stainless steel tong head is difficult to machine, prone to allergy and fatigue and high in cost are solved.

Description

Technical Field

[0001] This invention belongs to the field of medical endoscope technology, and particularly relates to a ceramic endoscope gripper head and its integrated molding method. Background Technology

[0002] Endoscopic forceps are a common endoscopic interventional consumable used for procedures such as tissue sampling, lesion resection, or foreign body removal during endoscopic examinations or treatments. They are typically made of stainless steel through machining and assembly processes. Due to the small size of the forceps head and the requirement for a uniform tooth structure with a specific radius of curvature and tooth arc, ensuring product stability during machining is challenging. Furthermore, during use, issues such as difficulty in smooth forceps head deployment, excessively sharp edges and teeth leading to tissue damage, and metal allergy complications in some patients often arise. Summary of the Invention

[0003] Therefore, the object of this invention is to provide a method for integrally molding the head of a ceramic endoscope gripper, comprising the following steps: The overall structure of the ceramic endoscope gripper head was designed using 3D modeling software. The structure includes an upper jaw, a lower jaw, a movable connecting rod, a connecting tube, a connecting thread, and a sheath. The upper jaw and the movable connecting rod are designed as an integrated unit, and the lower jaw and the connecting tube are designed as an integrated unit. Zirconia model ink and water-soluble support ink are prepared. The zirconia model ink has a solid content of 40%-50% and uses diethylene glycol butyl ether as the solvent system, with a solvent mass fraction of 50%-60%. The water-soluble support ink has a solid content of 30%-35% and uses one of propylene glycol phenyl ether, tripropylene glycol methyl ether, or tripropylene glycol phenyl ether as the solvent system, with a solvent mass fraction of 65%-70%. The particle size of both the zirconia model ink and the water-soluble support ink is 200-500 nanometers, and the viscosity is 10-20 mPa·s. Before spray molding, test samples are pre-printed on the substrate. Before printing the formal model, 10*10*10mm cube and φ10*10mm cylinder test samples need to be printed. After washing, drying and sintering, the shrinkage rate in the X, Y and Z directions is measured. Set the spray molding parameters as follows: substrate temperature 160-180℃, molding layer thickness 10μm, molding speed 40 seconds / layer, molding resolution 20. Zirconia model ink is used to spray the pliers structure layer by layer, and water-soluble support ink or a mixture of zirconia model ink and water-soluble support ink in different proportions is used to fill the gaps between the models, the toothed meshing parts, the hollow keyway and the gap between the movable connecting rod and the connecting tube. Print 2-5 layers, and use a spiral hob with 70-80 teeth and a diameter of 40-50mm to precisely mill the excess material. The milling cutter speed is 4500-5500rpm, the pressure angle is 15-25°, and the helix angle of the turning circle is no more than 12° to ensure the forming accuracy. After molding, the substrate temperature is reduced to 40-60℃, and the substrate is washed with water to remove water-soluble support material. Then, it is dried and sintered at high temperature to finally obtain a ceramic endoscope gripper head with a density ≥99.9%, a surface roughness Ra of 3-4μm, and a bending strength ≥800MPa.

[0004] Preferably, the mixing ratio of the zirconia model ink and the water-soluble support ink at the tooth-shaped interlocking gap is 6:4 to enhance the support strength and improve the molding accuracy.

[0005] Preferably, the hollow keyways of the upper and lower jaws and the movable keyway at the bottom of the connecting pipe are filled with 100% water-soluble support material to facilitate subsequent water washing and removal.

[0006] Preferably, the gap between the movable connecting rod and the connecting tube is filled with a mixture of water-soluble support material and zirconia model ink in an 8:2 ratio to ensure molding stability and ease of subsequent removal.

[0007] Preferably, the zirconia model ink and water-soluble support ink are mixed in a 5:5 ratio and filled in 2-5 layers in the contact area between the model and the substrate, so that the model can be easily detached from the substrate after sintering.

[0008] This invention also discloses a ceramic endoscope gripper head integrally formed by any of the above methods, wherein the gripper head is an integrally sintered ceramic body, comprising: Upper jaws, Lower jaws, The rotating shaft is located at the root of the two jaws. The connecting pipe extending rearward from the rotation axis, and A connecting thread is provided at the tail end of the connecting pipe; The maximum outer contour width of the upper and lower jaws in the closed state is ≤10mm, the total length is ≤50mm, the jaw opening height is ≤10mm, and the front teeth, the middle drainage channel and the root rotation structure of the two jaws are all formed on the same ceramic body in one piece, without the need for subsequent mechanical assembly.

[0009] Preferably, the outer contours of the upper and lower jaws are crocodile-shaped, and are smoothly transitioned by three arc segments with radii of R10mm, R25mm, and R6mm respectively.

[0010] Preferably, the upper jaw and the lower jaw each have 32 teeth, with a tooth height of 0.25 mm, and both the tooth tip and the tooth root have a chamfer of R0.1 mm.

[0011] Preferably, the upper jaw and the lower jaw each have two hollow keyways with a length of 5.0 mm and a radius of R10 mm at their center, with a distance of 2 mm between the two slots; each jaw has a through elliptical hole with a major diameter of 4 mm and a minor diameter of 2 mm at its root, for liquid discharge and to increase clamping friction.

[0012] Preferably, the rotating shaft has a clearance fit with the upper jaw and the movable connecting rod that is maintained after sintering; the connecting thread is an internal thread, and a sheath is provided at the tail end, the sheath having an outer diameter of 1.5 mm and an inner diameter of 0.85 mm, for quick connection with the surgical handle.

[0013] According to the technical solution of the present invention, the following beneficial effects can be achieved: This invention patent, through integrated model structure design and integrated spray molding, ensures the integrity of the toothed structure. It also incorporates hollow keyways and elliptical drainage holes, guaranteeing sufficient clamping force while reducing the weight of the forceps head, facilitating operation during surgery. Furthermore, the forceps head's closed width and length, along with its continuous arc design, allow for rapid and precise passage through narrow areas during surgery to reach the target object. Attached Figure Description

[0014] Figure 1 This is a structural diagram of the ceramic endoscope gripper head of the present invention; Figure 2 This is a flowchart of the integrated molding method for the ceramic endoscope gripper head of the present invention; 1 Upper jaw, 2 Lower jaw, 3 Connecting tube, 4 Connecting thread, 5 Sheath, 6 Rotating shaft, 7 Movable connecting rod. Detailed Implementation

[0015] Preferred embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0016] Example 1 Ceramic endoscope gripper head, wherein the gripper head is a single sintered ceramic body, such as Figure 1 As shown, it includes: Upper jaw 1, lower jaw 2, rotating shaft 6 located at the root of the two jaws, connecting pipe 3 extending rearward from the rotating shaft, and connecting thread 4 provided at the tail end of the connecting pipe; The maximum outer contour width of the upper and lower jaws in the closed state is ≤10mm, the total length is ≤50mm, the jaw opening height is ≤10mm, and the front teeth, the middle drainage channel and the root rotation structure of the two jaws are all formed on the same ceramic body in one piece, without the need for subsequent mechanical assembly.

[0017] In a preferred embodiment, the outer contours of the upper jaw 1 and the lower jaw 2 are crocodile-shaped, and are smoothly transitioned by three arc segments with radii of R10mm, R25mm and R6mm respectively.

[0018] In a preferred embodiment, the upper jaw and the lower jaw each have 32 teeth, with a tooth height of 0.25 mm and a chamfer of R0.1 mm at both the tooth tip and the tooth root.

[0019] In a preferred embodiment, the upper jaw and the lower jaw each have two hollow keyways with a length of 5.0 mm and a radius of R10 mm at their central parts, with a distance of 2 mm between the two slots; each jaw has a through elliptical hole with a major diameter of 4 mm and a minor diameter of 2 mm at its root, for liquid discharge and to increase clamping friction.

[0020] In a preferred embodiment, the rotating shaft 6 has a clearance fit with the upper jaw and the movable connecting rod 7 that is maintained after sintering; the connecting thread 4 is an internal thread, and a sheath 5 is provided at the tail end, the sheath having an outer diameter of 1.5 mm and an inner diameter of 0.85 mm, for quick connection with the surgical handle.

[0021] In a preferred embodiment, an integrated ceramic clamp head is constructed, with a total length of 50mm, a closing width of 10mm, and a maximum opening height of 10mm. The alligator-shaped outer contour features three tangential transitions at R10, R25, and R6mm. It has 32 teeth per clamp, a tooth height of 0.25mm, and a tooth tip / root chamfer of R0.1mm. Two central hollow keyways, each 5mm long and R10mm in diameter, are spaced 2mm apart. An elliptical drain hole at the root has a major axis of 4mm and a minor axis of 2mm. The rotation shaft clearance is 0.05mm – the green body size has been enlarged by 118%. The connecting pipe has an internal thread of M1.4, and the tail sheath has an outer diameter of 1.5mm and an inner diameter of 0.85mm. Based on the above preferred embodiment, a three-dimensional design is performed.

[0022] Example 2 Ink configuration: The zirconia model ink has a solid content of 45%, a particle size of 350nm, and uses diethylene glycol butyl ether as the solvent (55%), with a viscosity of 15mPa·s. The water-soluble support ink has a solid content of 32%, a particle size of 400nm, and uses propylene glycol phenyl ether as the solvent (68%), with a viscosity of 12mPa·s. Shrinkage calibration: Six 10×10×10mm cubes and six φ10×10mm cylinders were printed first. After washing and drying, they were sintered at 1550℃ for 2 hours. The average shrinkage rate in the X, Y, and Z directions was measured to be 18%, and the overall model was magnified 1.18 times. Spray molding parameters: Substrate temperature 170℃, layer thickness 10μm, resolution 20μm, spraying speed 40s / layer; the ratio of the toothed interlocking area model to the support is 6:4; all hollow keyways and movable keyways are filled with support material; the filling ratio of the gap between the movable connecting rod and the connecting tube is 8:2; the substrate transition area is filled with 3 layers at a 5:5 ratio, with a thickness of 30μm. Interlayer milling: Milling is performed once every 3 layers using a spiral hob with 75 teeth, a diameter of 45 mm, a rotation speed of 5000 rpm, a pressure angle of 20°, a pitch circle helix angle of 10°, and a distance of 60 μm between the hob tip and the substrate. Post-processing: After molding, the substrate is cooled to 50°C, ultrasonically cleaned with deionized water for 15 min to remove the support, dried at 80°C for 2 h, and finally sintered at 1550°C for 2 h.

[0023] Actual measurements showed a density of 99.92%, Ra 3.2 μm, and a flexural strength of 845 MPa. The jaws opened with a force of 2.1N, and no visible damage was observed after 30 clamping cycles into the pig's stomach. All dimensions fall within the design tolerance of ±20μm, there are no assembly steps, and the first-pass yield is 96%.

[0024] Example 3 Compared with Example 2, the model ink has a solid content of 40%, a supporting ink content of 30%, a particle size of 200 nm, and a viscosity of 10 mPa·s; The layer thickness was reduced to 5μm, and the spraying speed was 80s / layer; Instead of intermediate milling, use a negative pressure scraper to remove excess ink every 5 layers. The overall size is reduced by 10% (length 45mm, width 9mm), tooth height 0.20mm, chamfer R0.08mm, sheath outer diameter 1.35mm, inner diameter 0.75mm; the remaining structural features are the same as in Example 1; After sintering, the density is 99.7%, Ra 2.1μm, and bending strength is 815MPa; it passes smoothly through the φ2.0mm endoscope clamp channel.

[0025] Example 4 Compared with Example 2, the model ink has a solid content of 50%, a supporting ink content of 35%, a particle size of 500 nm, and a viscosity of 20 mPa·s; The tooth occlusal area mixing ratio is 7:3 to improve support rigidity; the tooth height is increased to 0.30mm, while the tooth root chamfer remains at R0.1mm; Milling cutter parameters: 80 teeth, 50mm diameter, 5500rpm speed, 25° pressure angle, 12° pitch circle helix angle; Sintering at 1580℃ for 2 hours resulted in a density of 99.95%, Ra 2.8μm, and a flexural strength of 875MPa. With a jaw opening force of 2.6N, it can continuously clamp stomach wall tissue up to 3mm thick without tooth breakage; the rotation shaft clearance is 0.06mm, and the wear after 10,000 opening and closing cycles is less than 2μm, still meeting the requirements for single use.

[0026] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of integrally forming a ceramic endoscope forceps head, characterized by, Comprising the following steps: Design the overall structure of the ceramic endoscope forceps head by three-dimensional modeling software, which includes upper jaw, lower jaw, movable connecting rod, connecting tube, connecting thread and sheath head, wherein the upper jaw is designed integrally with the movable connecting rod, and the lower jaw is designed integrally with the connecting tube; Zirconia modeling ink and water-soluble support ink are configured, wherein the solid content of the zirconia modeling ink is 40%-50%, the solvent system is diethylene glycol butyl ether, and the solvent mass fraction is 50%-60%; the solid content of the water-soluble support ink is 30%-35%, the solvent system is one of propylene glycol phenyl ether, tripropylene glycol methyl ether or tripropylene glycol phenyl ether, and the solvent mass fraction is 65%-70%; the particle size of the zirconia modeling ink and the water-soluble support ink is 200-500 nanometers, and the viscosity is 10-20 mPa·s; Before spray forming, pre-print test blocks on the substrate, print 10*10*10mm cubic test blocks and φ10*10mm cylindrical test blocks before printing the formal model, and measure the shrinkage rate in X, Y and Z directions after washing, drying and sintering; Set the spray forming parameters: the substrate temperature is 160-180℃, the forming layer thickness is 10μm, the forming speed is 40 seconds per layer, and the forming resolution is 20; Zirconia modeling ink is used for layer-by-layer spray forming of the head structure, and water-soluble support ink or a mixture of zirconia modeling ink and water-soluble support ink in different proportions is used for filling in the model gap, tooth-shaped occlusion part, hollow key groove and gap between movable connecting rod and connecting tube; Print 2-5 layers, and use a helical hob with 70-80 teeth and a diameter of 40-50mm to precisely mill the excess material, with a hob rotational speed of 4500-5500rpm, a pressure angle of 15-25°, and a fractional circular helix angle not greater than 12°, to ensure forming accuracy; After forming is completed, the substrate temperature is reduced to 40-60℃, and the water-soluble support material is removed by washing, followed by drying and high-temperature sintering, to finally obtain a ceramic endoscope forceps head with a density of ≥99.9%, a surface roughness Ra of 3-4μm and a bending strength of ≥800MPa.

2. The method of claim 1, wherein: The mixing and filling ratio of the zirconia modeling ink and the water-soluble support ink in the tooth-shaped occlusion gap is 6:4, to enhance the support strength and improve the forming accuracy.

3. The method of claim 1, wherein: The hollow key groove of the upper and lower jaws and the movable key groove at the bottom of the connecting tube are filled with 100% water-soluble support material, to facilitate subsequent water washing removal.

4. The method of claim 1, wherein: The gap between the movable connecting rod and the connecting tube is filled with a mixture of water-soluble support material and zirconia modeling ink in a ratio of 8:2, to ensure forming stability and subsequent removal convenience.

5. The method of claim 1, wherein: The zirconia modeling ink and the water-soluble support ink are mixed in a ratio of 5:5 and filled in the contact area between the model and the substrate for 2-5 layers, to facilitate the smooth separation of the model from the substrate after sintering.

6. A ceramic endoscope forceps tip integrally formed by the method of any one of claims 1 to 5, characterized in that, The plier head is a whole sintered ceramic body, comprising: an upper jaw, a lower jaw, a rotating shaft at the root of the two jaws, a connecting tube extending from the rotating shaft rearward, and a connecting thread provided at the tail end of the connecting tube; wherein the maximum outer profile width of the upper jaw and the lower jaw in the closed state is ≤10mm, the total length is ≤50mm, the jaw opening height is ≤10mm, and the front tooth shape, the middle liquid passage and the root rotating structure of the two jaws are all formed on the same ceramic body at one time, without subsequent mechanical assembly.

7. The ceramic plier head according to claim 6, characterized in that: the outer profile of the upper jaw and the lower jaw is in the shape of a long-nosed crocodile, smoothly transitioned by three circular arcs with radii of R10mm, R25mm and R6mm, respectively.

8. The ceramic plier head according to claim 6, characterized in that: each of the upper jaw and the lower jaw is provided with 32 teeth, with a tooth height of 0.25mm, and R0.1mm chamfer provided at the tooth tip and the tooth root.

9. The ceramic plier head according to any one of claims 6, characterized in that: the central part of each of the upper jaw and the lower jaw is provided with two long hollow key grooves with a length of 5.0mm and a radius of R10mm, with a distance of 2mm between the two grooves; and each of the roots of the two jaws is provided with a through elliptical hole with a major diameter of 4mm and a minor diameter of 2mm, for liquid discharge and increasing clamping friction.

10. The ceramic plier head according to any one of claims 6-9, characterized in that: a gap is left between the rotating shaft and the upper jaw and the movable connecting rod after sintering, which is still kept; the connecting thread is an internal thread, and a sheath head is further provided at the tail, with an outer diameter of 1.5mm and an inner diameter of 0.85mm, for quick connection with a surgical handle.

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