A dental sandblasting nozzle and sandblasting handle

Abstract

This utility model discloses a dental air-blasting nozzle and air-blasting handle, belonging to the field of dental medical equipment technology. The nozzle includes: a shell with a continuous central cavity, wherein at least one water guide hole is radially penetrating the central cavity on the same cross-section near the rear end; an air-sand mixing pipe; a curved guide pipe; and a nozzle pipe. This utility model reduces flow resistance at corners through the smooth transition design of the curved guide pipe, preventing sand powder from accumulating in the channel and significantly reducing the risk of sand blockage. Simultaneously, the coaxial layout of the water channel and the air-sand mixing pipe, through the first and second water guide grooves, ensures that water is uniformly delivered forward along the gap between the central cavity and the internal pipes. The coaxial design of the annular outlet and the nozzle pipe forms a stable annular water flow, which is sprayed synchronously with the air-sand mixture, causing the water flow to envelop the sand powder in an annular shape, ensuring efficient mixing of sand powder and water, preventing sand powder from flying away under the action of airflow, and improving the cleanliness and safety of the treatment environment.

Description

Technical Field

[0001] This utility model relates to the field of dental medical equipment technology, and in particular to a nozzle and a handle for a dental sandblasting handle. Background Technology

[0002] Dental air polishing is increasingly widely used in modern dental treatment and cosmetic dentistry due to its high efficiency in removing plaque, stains (such as tobacco and tea stains), and early soft deposits, while causing relatively little damage to tooth enamel. This technology primarily relies on an air polishing handle to mix high-pressure gas and water with specific abrasive powder (such as glycine powder or sodium bicarbonate powder), forming a high-speed jet that acts on the tooth surface to achieve cleaning and polishing effects. Its core functional components typically include: an air intake channel, a liquid intake channel, a sand intake channel or mixing chamber, and a nozzle that ultimately ejects the gas-liquid-sand mixture. During use, the abrasive powder is drawn into the mixing chamber by gravity, the Venturi effect, or auxiliary airflow, mixes with the high-speed gas and liquid, and is then ejected.

[0003] However, existing dental air polishing handles are prone to clogging. On one hand, the design of the air inlet channel in existing handles is flawed, with numerous internal bends. These bends obstruct the flow of air polishing powder, preventing it from passing smoothly through the channel. On the other hand, when air polishing powder comes into contact with compressed air and mixes with it, it easily adheres and clumps. Once this adhered or clumped powder forms, it easily accumulates at the bends of the handle due to the obstructed flow. Frequent clogging not only reduces the reliability of dental air polishing equipment and significantly impacts the user experience, but also significantly increases the cost and complexity of equipment maintenance. Each time clogging occurs, medical staff need to spend extra time cleaning and adjusting, severely affecting clinical efficiency. Simultaneously, patients may experience negative experiences during treatment due to equipment malfunctions, leading to concerns about the treatment's effectiveness. Utility Model Content

[0004] The purpose of this utility model is to provide a nozzle and a handle for a dental sandblasting handle, so as to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] This utility model provides a nozzle for a dental air-blasting handle, comprising:

[0007] The outer shell has a continuous central cavity extending from the opposite rear end to the front end along the central axis of the outer shell. The central cavity has at least one water guide hole extending radially through it on the same cross section near the rear end.

[0008] An air-sand mixing pipe is coaxially disposed at the rear of the central cavity. The gap between the central cavity and the air-sand mixing pipe forms a water channel. The air-sand mixing pipe is provided with a fitting section that is radially enlarged near the rear end. The fitting section is in close contact with the cavity wall of the central cavity to form the closed end of the water channel. The water guide hole is located in front of the fitting section.

[0009] A bend guide pipe is coaxially disposed at the front of the central cavity and connected to the front end of the air-sand mixing pipe. The rear end of the bend guide pipe is provided with a first annular protrusion that abuts against the cavity wall of the central cavity. The first annular protrusion has several first water guide grooves penetrating through it in the axial direction of the central axis. The water channel extends forward along the gap between the central cavity and the bend guide pipe after passing through the first water guide grooves.

[0010] The nozzle tube is coaxially arranged at the front end outlet of the central cavity, and the gap between them forms an annular water outlet. The rear end of the nozzle tube is connected to the bend guide tube. The middle part is provided with a second annular boss that abuts against the cavity wall of the central cavity. The second annular boss has several second water guide grooves penetrating through it in the axial direction of the central axis. The water channel is connected to the annular water outlet through the second water guide grooves.

[0011] This technical solution reduces flow resistance at corners by using a smooth transition design for the bend guide pipe, preventing sand powder from accumulating in the channel and significantly reducing the risk of sand blockage. Simultaneously, the coaxial layout of the water channel and the air-sand mixing pipe, ensured by a ring boss, guarantees the stability of the coaxial structure. The water channel, through the first and second guide channels, ensures that water is uniformly transported forward along the gap between the central cavity and internal pipes. The coaxial design of the annular outlet and the nozzle pipe forms a stable annular water flow, which is sprayed synchronously with the air-sand mixture, causing the water flow to envelop the sand powder in a ring shape. This ensures efficient mixing of sand powder and water, preventing sand powder from being scattered by the airflow and improving the cleanliness and safety of the treatment environment.

[0012] As an extension of the above solution: the first water guide channel is arranged in a circular array around the central axis, and the second water guide channel is also arranged in a circular array around the central axis. This ensures that the water flow is evenly distributed circumferentially when passing through the water guide channels, avoiding local water flow concentration or insufficient flow, reducing local pressure fluctuations caused by water flow deviation, and ultimately forming a stable and symmetrical annular water film at the annular outlet, ensuring that sand and dust are evenly coated, further solving the sand lifting problem.

[0013] As an extension of the above scheme: the central cavity has a smooth shape with multiple continuous transitions from the relative rear end to the front end, including a straight line segment from the rear end to the middle, an arc segment that gently rises at a small angle from the middle, a transition segment that extends tangentially along the end of the arc segment, a bend segment that is tangential to the end of the transition segment and extends downwards, and a front end outlet that extends tangentially along the end of the bend segment.

[0014] The central cavity of this extended design adopts a smooth, multi-segment, continuous, tangential shape to eliminate right-angle or acute-angle corners, allowing the air-sand mixture to flow along a smooth trajectory within the channel. This avoids sand and dust accumulation caused by eddies or stagnation at corners, significantly reducing the risk of sand blockage.

[0015] As an extension of the above solution: A first threaded section, a first sealing groove, and a limiting ring are sequentially arranged behind the fitting section. A second threaded section is provided at the rear end of the central cavity. The air-sand mixing pipe is fixed in the central cavity through the engagement of the first and second threaded sections. One side of the limiting ring abuts against the rear end face of the outer shell. A first sealing ring is provided on the first sealing groove. The axial feed characteristic of the threaded engagement ensures that the air-sand mixing pipe is gradually screwed in along the central axis, avoiding radial offset and ensuring coaxiality with the central cavity. The first sealing groove is an annular groove on the outer wall of the air-sand mixing pipe, with the first sealing ring inside. When the air-sand mixing pipe is tightened, the first sealing ring is compressed between the sealing groove and the inner wall of the central cavity, forming a radial seal and further preventing water leakage from the water channel.

[0016] As an extension of the above solution: the outer casing has second sealing grooves on the axial direction of the central axis, respectively in front of and behind the water guide hole, and a second sealing ring is provided on the second sealing groove. This extended solution blocks the penetration of water flow into other areas inside the handle, ensuring that all water flow enters the water channel through the water guide hole, guiding the water flow in a directional manner, and improving water utilization and spray stability.

[0017] On the other hand, this utility model also provides a sandblasting handle, including a nozzle for a dental sandblasting handle as described above. By integrating a coaxial water channel and an air-sand channel structure, the sandblasting handle ensures the mixing and spraying function of the entire machine, significantly reducing or even eliminating the risk of sand blockage, improving the flowability of the sandblasting powder within the channels, and allowing the sand powder to mix better with water after being sprayed out, avoiding sand scattering defects, and improving clinical work efficiency and patient experience.

[0018] As an extension of the above solution, the sandblasting handle also includes:

[0019] The first core has a hollow structure, with its front end sleeved on the rear end of the outer shell. The inner wall of the first core has an annular channel corresponding to the water guide hole. The rear diameter of the first core is larger than the middle diameter, forming an annular step. The wall of the first core has a water inlet channel extending from the step surface of the annular step to the annular channel.

[0020] The second core is inserted at the rear of the first core. The second core has an air-sand input channel and a water input channel. One end of the air-sand input channel is connected to an external pipe that provides air and sand powder, and the other end is connected to the air-sand mixing pipe. One end of the water input channel is connected to an external water supply pipe, and the other end is connected to the water inlet channel.

[0021] This extended solution achieves physical isolation between the water path and the air-sand path through the separate design of the first core and the second core, avoiding mutual interference between the two during transportation; the corresponding design of the annular channel and the water guide hole ensures that the water flows smoothly into the water channel of the nozzle, and the direct connection between the air-sand input channel and the air-sand mixing pipe ensures the stable transportation of the air-sand mixture and improves the reliability of media transportation.

[0022] As an extension of the above solution: a snap-fit ​​part is provided at the center of the front end face of the second core, the air-sand input channel is located at the central axis of the second core, and the snap-fit ​​part is connected to the end of the air-sand mixing pipe through a sealing sleeve, so that air and sand powder are ejected sequentially through the air-sand input channel, the sealing sleeve, the air-sand mixing pipe, the bend guide pipe and the nozzle pipe.

[0023] The snap-fit ​​part of this extension solution is positioned and fitted with the end of the air-sand mixing pipe through a sealing sleeve, ensuring that the air-sand input channel and the air-sand mixing pipe are coaxially connected, preventing the high-pressure air-sand mixture from leaking from the connection gap, reducing pressure loss, ensuring stable injection kinetic energy, and ensuring that the air-sand mixture is efficiently delivered to the nozzle along the preset path.

[0024] As an extension of the above solution: there is a gap between the front end face of the second core and the step surface of the annular step, forming an annular water guiding channel. The water input channel is offset from the central axis of the second core and extends out of the front end face to communicate with the water guiding channel. The water input channel is connected to the water guiding channel and is structurally completely independent from the central air and sand input channel, separated by the solid part of the second core to ensure that the fluids do not interfere with each other.

[0025] As an extension of the above solution: the second core has a third sealing groove on the axial direction of its central axis, opposite to the front and rear of the water guiding channel, and a third sealing ring is provided on the third sealing groove. This extension effectively prevents water from leaking through the gap between the second core and the first core, ensuring that all water flows through the water guiding channel into the inlet channel, improving water circuit efficiency. It also further isolates the water guiding channel from the surrounding area, especially the central air-sand input channel, preventing water from seeping into the air-sand channel and causing sand powder to caking. At the same time, it prevents high-pressure gas in the air-sand mixture from back-impacting the water circuit, ensuring the independent and stable operation of the two fluid paths. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0027] Figure 1 This is a schematic diagram of the nozzle structure in an embodiment;

[0028] Figure 2 This is a schematic diagram of the exploded structure of the nozzle in the embodiment;

[0029] Figure 3 This is a cross-sectional structural diagram of the nozzle in the embodiment;

[0030] Figure 4 This is a cross-sectional structural diagram of the outer shell of the embodiment;

[0031] Figure 5 This is a cross-sectional structural diagram of the sandblasting handle in the embodiment;

[0032] Figure 6 This is a partial cross-sectional structural diagram of the sandblasting handle in an embodiment.

[0033] In the attached diagram: 100: Outer shell; 110: Central cavity; 111: Straight section; 112: Curved section; 113: Transition section; 114: Bend section; 115: Front outlet; 120: Water guide hole; 130: Second threaded section; 140: Second sealing groove; 150: Second sealing ring; 200: Air-sand mixing pipe; 210: Fitting section; 220: First threaded section; 230: First sealing groove; 240: Limiting ring; 250: First sealing ring; 300: Bend guide pipe; 310: First... 320: First water guide groove; 400: Nozzle pipe; 410: Annular outlet; 420: Second annular boss; 430: Second water guide groove; 500: First core; 510: Annular channel; 520: Annular step; 530: Water inlet channel; 540: Water guide channel; 600: Second core; 610: Air and sand input channel; 620: Water input channel; 630: Snap-fit ​​part; 640: Third sealing groove; 650: Third sealing ring; 700: Sealing sleeve; 800: Support connecting sleeve. Detailed Implementation

[0034] This section will describe in detail the specific embodiments of the present utility model. The preferred embodiments of the present utility model are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present utility model, but they should not be construed as limiting the scope of protection of the present utility model.

[0035] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0036] In the description of this utility model, if there are words such as "several", they mean one or more, "multiple" means two or more, "greater than", "less than", "exceeding" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself.

[0037] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0038] Reference Figures 1 to 6 The following are several embodiments of a dental sandblasting handle nozzle and sandblasting handle according to the present invention.

[0039] An embodiment of this utility model provides a nozzle for a dental air-blasting handle, such as... Figures 1 to 3 As shown, it includes:

[0040] The outer casing 100 has a continuous central cavity 110 extending from the opposite rear end to the front end along the central axis of the outer casing 100. The central cavity 110 has at least one water guide hole 120 extending radially through it on the same cross section near the rear end.

[0041] An air-sand mixing pipe 200 is coaxially disposed at the rear of the central cavity 110. The gap between the central cavity 110 and the air-sand mixing pipe 200 forms a water channel. The air-sand mixing pipe 200 is provided with a radially enlarged fitting section 210 near the rear end. The fitting section 210 is in close contact with the cavity wall of the central cavity 110 to form the closed end of the water channel. The water guide hole 120 is located in front of the fitting section 210.

[0042] A bend guide pipe 300 is coaxially disposed at the front of the central cavity 110 and connected to the front end of the air-sand mixing pipe 200. The rear end of the bend guide pipe 300 is provided with a first annular boss 310 that abuts against the cavity wall of the central cavity 110. The first annular boss 310 has a plurality of first water guide grooves 320 passing through it in the axial direction of the central axis. The water channel extends forward along the gap between the central cavity 110 and the bend guide pipe 300 after passing through the first water guide grooves 320.

[0043] The nozzle tube 400 is coaxially arranged at the front end outlet 115 of the central cavity 110 and the gap between them forms an annular water outlet 410. The rear end of the nozzle tube 400 is connected to the bend guide tube 300. The middle part is provided with a second annular boss 420 that abuts against the cavity wall of the central cavity 110. The second annular boss 420 has several second water guide grooves 430 passing through it in the axial direction of the central axis. The water channel is connected to the annular water outlet 410 through the second water guide grooves 430.

[0044] In this embodiment, the central axis of the outer shell is a spatial curve whose shape changes synchronously with the bending and diameter changes of the outer shell, remaining at the center of the outer shell cross-section throughout its length or extension direction; the water channel refers to the annular channel between the central cavity and the air-sand mixing pipe, the bend guide pipe, and the nozzle pipe, respectively, used for water or liquid flow; the radially penetrating water guide holes are the inlets for external water flow into the water channel, and their number can be set according to the flow rate requirements, preferably 2-4, symmetrically distributed in a circle; the first and second annular bosses are set to abut against the cavity wall of the central cavity, i.e., without clearance, and are for the bend guide pipe and the nozzle. The pipes provide support, ensuring that the bend guide pipe and nozzle pipe are coaxially and centrally positioned with the central cavity. However, the lack of clearance would block the water channel. In this embodiment, the first and second water guide grooves are opened axially to guide the water flow path of the water channel. This not only serves as a positioning function, ensuring that each pipe can be stably and coaxially centered, but also ensures that the water flow in the water channel can pass through the annular boss and continue to flow forward, avoiding the annular boss from blocking the water flow. The annular outlet is coaxially centered, ensuring the formation of a stable annular water film, which effectively wraps the sand powder. After the sand powder is sprayed out, the water ring wraps the sand powder and sprays it onto the tooth surface, preventing the sand powder from being blown away by the air and flying everywhere.

[0045] In operation, high-pressure gas carrying abrasive powder enters the air-sand mixing pipe from its rear end, flows forward through the pipeline to the bend guide pipe, and then into the nozzle pipe. The bend guide pipe features a rounded bend in its flow channel to reduce flow resistance at the corner, preventing abrasive powder from accumulating in the channel and significantly reducing the risk of blockage. External water enters the water channel between the central cavity and the air-sand mixing pipe through the water guide hole, flows forward to the first annular boss, passes through the first water guide groove into the gap between the central cavity and the bend guide pipe, continues forward to the second annular boss, and passes through the second water guide groove into the annular outlet. The water flow at the annular outlet merges with the air-sand mixture ejected from the nozzle pipe at the outlet, and the water flow annularly envelops the abrasive powder, achieving efficient mixing of gas, liquid, and abrasive before spraying it onto the tooth surface.

[0046] This embodiment reduces flow resistance at corners by using a smooth transition design for the bend guide pipe, preventing sand powder from accumulating in the channel and significantly reducing the risk of sand blockage. Simultaneously, the coaxial layout of the water channel and the air-sand mixing pipe, with annular bosses ensuring the stability of the coaxial structure, ensures that the water flow is uniformly delivered forward along the gap between the central cavity and internal pipes through the first and second guide channels. The coaxial design of the annular outlet and nozzle pipe forms a stable annular water flow, which is sprayed synchronously with the air-sand mixture, causing the water flow to envelop the sand powder in an annular pattern. This ensures efficient mixing of sand powder and water, preventing sand powder from being scattered by the airflow and improving the cleanliness and safety of the treatment environment.

[0047] In an optional embodiment, such as Figure 2 As shown, the first water guide channel 320 and the second water guide channel 430 are arranged in a circular array around the central axis. This circular array arrangement ensures that the water flow is evenly distributed circumferentially as it passes through the channels, avoiding localized water concentration or insufficient flow, reducing localized pressure fluctuations caused by water flow deviation, and ultimately forming a stable and symmetrical annular water film at the annular outlet. This ensures that sand and dust are evenly coated, further solving the problem of sand lifting.

[0048] In an optional embodiment, such as Figure 4 As shown, the central cavity 110 has a smooth shape with multiple continuous transitions from the opposite rear end to the front end, including a straight line segment 111 that is flat from the rear end to the middle, an arc segment 112 that gently rises at a small angle from the middle upwards, a transition segment 113 that extends tangentially along the end of the arc segment 112, a bend segment 114 that is tangential to the end of the transition segment 113 and extends downwards, and a front end outlet 115 that extends in a straight line tangentially along the end of the bend segment 114.

[0049] In this embodiment, the central cavity is divided into five continuously transitioning segments from the rear end to the front end. These segments are tangentially connected, meaning that the centerlines of adjacent segments have the same tangential direction at the connection point, forming a smooth channel without inflection points. The centerline of the gently upward-sloping arc segment is a circular arc, extending upwards at an angle of 1°-5°, based on the horizontal axis of the straight segment. This combination of upward slope and reverse curvature allows the nozzle tip to adapt to the complex operating space inside the oral cavity, such as the inner side of molars and the gum line, facilitating adjustments to the spray angle by medical personnel and improving cleaning precision. The central cavity adopts a multi-segment, continuously tangential, smooth shape, eliminating right-angle or acute-angle corners. This allows the air-sand mixture to flow along a smooth trajectory within the channel, avoiding sand accumulation caused by eddies or stagnation at corners, significantly reducing the risk of sand blockage.

[0050] In an optional embodiment, such as Figure 2 and Figure 3 As shown, the fitting section 210 is provided with a first threaded section 220 (thread not shown in the figure), a first sealing groove 230 and a limiting ring 240 in sequence at the rear. The rear end of the central cavity 110 is provided with a second threaded section 130. The air-sand mixing pipe 200 is fixed in the central cavity 110 by the cooperation of the first threaded section 220 and the second threaded section 130. The limiting ring 240 abuts against the rear end face of the outer shell 100 on one side. The first sealing groove 230 is provided with a first sealing ring 250.

[0051] In this embodiment, the axial feed characteristic of the threaded fit ensures that the air-sand mixing tube is gradually screwed in along the central axis, avoiding radial offset and ensuring coaxiality with the central cavity. The first sealing groove is an annular groove on the outer wall of the air-sand mixing tube, with a first sealing ring inside. When the air-sand mixing tube is tightened, the first sealing ring is compressed between the sealing groove and the inner wall of the central cavity, forming a seal and further blocking the water flow from leaking backward through the water channel.

[0052] In an optional embodiment, such as Figures 1 to 3 As shown, the outer casing 100 has second sealing grooves 140 respectively in front of and behind the water guide hole 120 along the axial direction of the central axis. A second sealing ring 150 is provided on the second sealing groove 140. The first and second sealing grooves are annular grooves opened on the outer wall of the outer casing. The first and second sealing rings prevent water from seeping into other areas inside the handle, ensuring that all water flows through the water guide hole into the water channel, guiding the water flow in a directional manner, and improving water utilization and spray stability.

[0053] On the other hand, this utility model also provides a sandblasting handle, including a nozzle for a dental sandblasting handle as described in one or more optional embodiments above. By integrating a coaxial water channel and an air-sand channel structure, the sandblasting handle ensures the mixing and spraying function of the entire device, significantly reducing or even eliminating the risk of sand clogging, improving the flowability of the sandblasting powder within the channels, and allowing for better mixing of the sand powder with water after spraying, avoiding sand scattering defects, and improving clinical work efficiency and patient experience.

[0054] In an optional embodiment, such as Figure 5 and Figure 6 As shown, the sandblasting handle also includes:

[0055] The first core 500 has a hollow structure, with its front end sleeved on the rear end of the outer shell 100. The inner wall of the first core 500 has an annular channel 510 corresponding to the water guide hole 120. The rear diameter of the first core 500 is larger than the middle diameter, forming an annular step 520. The wall of the first core 500 has a water inlet channel 530 extending from the step surface of the annular step 520 to the annular channel 510.

[0056] The second core 600 is inserted into the rear of the first core 500. The second core 600 has an air-sand input channel 610 and a water input channel 620. One end of the air-sand input channel 610 is connected to an external pipe that provides air and sand powder, and the other end is connected to the air-sand mixing pipe 200. One end of the water input channel 620 is connected to an external water supply pipe, and the other end is connected to the water inlet channel 530.

[0057] In this embodiment, the hollow structure of the first core provides assembly space for the air-sand mixing pipe, ensuring that the air-sand mixing pipe is coaxially connected to the air-sand input channel of the second core. External high-pressure gas carries sand powder into the air-sand mixing pipe through the air-sand input channel of the second core, and is conveyed forward along the air-sand mixing pipe to the bend guide pipe, and finally sprayed out from the nozzle pipe, mixing with the annular water flow and acting on the tooth surface. The front inner wall of the first core is fixed to the rear outer wall of the outer shell by a threaded connection, and the threaded connection is located in front of the second sealing groove. The annular channel is a circumferential groove on the inner wall of the first core, and its position corresponds to the water guide hole of the outer shell. It is used to guide the water flow from the water inlet channel into the water guide hole. The water inlet channel is an axial channel that runs from the stepped surface of the annular step to the annular channel, introducing the water flow conveyed by the water input channel of the second core into the annular channel, the water guide hole, and the water channel, and finally spraying out through the annular outlet, mixing with the air-sand mixture and acting on the tooth surface.

[0058] This embodiment achieves physical isolation between the water path and the air-sand path through the separate design of the first core and the second core, avoiding mutual interference between the two during the transportation process; the corresponding design of the annular channel and the water guide hole ensures that the water flow smoothly enters the water channel of the nozzle, and the direct connection between the air-sand input channel and the air-sand mixing pipe ensures the stable transportation of the air-sand mixture and improves the reliability of the medium transportation.

[0059] In an optional embodiment, such as Figure 5 and Figure 6 As shown, a snap-fit ​​part 630 protrudes from the center of the front end face of the second core 600. The air-sand input channel 610 is located at the central axis of the second core 600. The snap-fit ​​part 630 is connected to the end of the air-sand mixing pipe 200 through the sealing sleeve 700, so that air and sand powder are sprayed out sequentially through the air-sand input channel 610, the sealing sleeve 700, the air-sand mixing pipe 200, the bend guide pipe 300, and the nozzle pipe 400.

[0060] In this embodiment, the snap-fit ​​part is a cylindrical protrusion protruding from the center of the front end face of the second core. The snap-fit ​​part and the second core are integrally formed, and its central axis is completely coincident with the central axis of the second core and / or the axis of the air-sand input channel to ensure positioning accuracy. The snap-fit ​​part has several mounting grooves on its outer surface, which cooperate with the annular protrusions on the inner wall of the sealing sleeve to achieve assembly and fixation. After assembly, the two ends of the sealing sleeve are respectively sleeved on the outer sides of the snap-fit ​​part and the air-sand mixing tube. In some preferred embodiments, a support connecting sleeve 800 is also sleeved on the outer side of the sealing sleeve 700. The outer wall of the support connecting sleeve 800 abuts against the inner wall of the first core 500, which plays a supporting and positioning role and ensures the coaxiality of the docking. External high-pressure gas carrying sand powder enters the snap-fit ​​part through the air-sand input channel of the second core, flows into the air-sand mixing tube through the inner cavity of the sealing sleeve, and is ejected sequentially through the bend guide tube and the nozzle tube.

[0061] In this embodiment, the snap-fit ​​part and the end of the air-sand mixing pipe are positioned and fitted by a sealing sleeve to ensure that the air-sand input channel and the air-sand mixing pipe are coaxially connected, preventing the high-pressure air-sand mixture from leaking from the connection gap, reducing pressure loss, ensuring stable injection kinetic energy, and ensuring that the air-sand mixture is efficiently delivered to the nozzle along the preset path.

[0062] In an optional embodiment, such as Figure 5 and Figure 6 As shown, there is a gap between the front end face of the second core 600 and the step surface of the ring step 520, forming an annular water guiding channel 540. The water input channel 620 is offset from the central axis of the second core 600 and extends out of the front end face to communicate with the water guiding channel 540.

[0063] In this embodiment, the water guiding channel is formed by the axial gap between the front end face of the second core and the stepped surface of the annular step of the first core, and it surrounds the air-sand input channel in a ring shape with a gap width of 0.5-2mm. The water input channel is arranged parallel to the central axis of the second core, and its outlet end extends out of the front end face of the second core and communicates with the water guiding channel. It is structurally completely independent from the central air-sand input channel and is separated by the solid part of the second core to ensure that the fluids do not interfere with each other. External water enters the second core through the water input channel, sprays out from the outlet of the front end face, and enters the water guiding channel. The water flow diffuses circumferentially in the annular space, filling the entire gap. Subsequently, the water flow enters the annular channel at the front end of the first core through the water inlet channel on the annular step of the first core, and finally enters the water channel through the water guide hole of the nozzle, completing the water transportation and distribution.

[0064] In an optional embodiment, such as Figure 6 As shown, the second core 600 has a third sealing groove 640 on the axial direction of the central axis, opposite to the front and rear of the water guiding channel 540, and a third sealing ring 650 is provided on the third sealing groove.

[0065] In this embodiment, the front third sealing groove and third sealing ring prevent water from leaking forward from the water guide channel to the front gap between the first and second cores, and the rear third sealing groove and third sealing ring prevent water from leaking backward into the handle body, ensuring that the water flows only within the water guide channel. After the external water source enters the water guide channel through the water input channel, the water can only diffuse circumferentially within the water guide channel because the front third sealing ring blocks the forward leakage path and the rear third sealing ring blocks the backward leakage path. It then enters the subsequent water path through the water inlet channel of the first core. At the same time, the sealing effect of the sealing ring prevents high-pressure gas from the air-sand input channel from entering the water path, ensuring that the two fluids do not interfere with each other and are stably delivered to the nozzle.

[0066] This embodiment effectively prevents water from leaking through the gap between the second core and the first core, ensuring that all water flows into the inlet channel through the water guide channel, improving water circuit efficiency. It also further isolates the water guide channel from the surrounding area, especially the central air-sand input channel, to prevent water from seeping into the air-sand channel and causing sand powder to caking. At the same time, it prevents high-pressure gas in the air-sand mixture from impacting the water circuit in the reverse direction, ensuring that the two fluids operate independently and stably.

[0067] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A nozzle for a dental sandblasting handle, characterized in that include: The outer casing (100) has a continuous central cavity (110) extending from the opposite rear end to the front end along the central axis of the outer casing (100), and the central cavity (110) has at least one water guide hole (120) extending radially through the same cross section near the rear end. An air-sand mixing pipe (200) is coaxially disposed at the rear of the central cavity (110). The gap between the central cavity (110) and the air-sand mixing pipe (200) forms a water channel. The air-sand mixing pipe (200) is provided with a fitting section (210) that is radially enlarged near the rear end. The fitting section (210) is in close contact with the cavity wall of the central cavity (110) to form the closed end of the water channel. The water guide hole (120) is located in front of the fitting section (210). A bend guide pipe (300) is coaxially disposed at the front of the central cavity (110) and connected to the front end of the air-sand mixing pipe (200). The rear end of the bend guide pipe (300) is provided with a first annular boss (310) that abuts against the cavity wall of the central cavity (110). The first annular boss (310) has a plurality of first water guide grooves (320) passing through it in the axial direction of the central axis. The water channel extends forward along the gap between the central cavity (110) and the bend guide pipe (300) after passing through the first water guide grooves (320). The nozzle tube (400) is coaxially arranged at the front end outlet (115) of the central cavity (110) and the gap between them forms an annular water outlet (410). The rear end of the nozzle tube (400) is connected to the bend guide tube (300). The middle part is provided with a second annular boss (420) that abuts against the cavity wall of the central cavity (110). The second annular boss (420) has several second water guide grooves (430) passing through it in the axial direction of the central axis. The water channel is connected to the annular water outlet (410) through the second water guide grooves (430).

2. A spray tip for a sandblasting handle according to claim 1, characterized in that: The first water guide channel (320) is arranged in a circular array with the central axis as the center, and the second water guide channel (430) is arranged in a circular array with the central axis as the center.

3. A spray tip for a sandblasting handle according to claim 1, characterized in that: The central cavity (110) has a smooth shape with multiple continuous transitions from the opposite rear end to the front end, including a straight line segment (111) from the rear end to the middle, an arc segment (112) that rises gently upward at a small angle from the middle, a transition segment (113) that extends tangentially to the end of the arc segment (112), a bend segment (114) that is tangential to the end of the transition segment (113) and extends downward, and a front end outlet (115) that extends straight along the tangential direction to the end of the bend segment (114).

4. The tip for a sandblasting handle according to claim 1, characterized in that: The fitting section (210) is provided with a first threaded section (220), a first sealing groove (230) and a limiting ring (240) in sequence at the rear. The rear end of the central cavity (110) is provided with a second threaded section (130). The air-sand mixing pipe (200) is fixed in the central cavity (110) through the cooperation of the first threaded section (220) and the second threaded section (130). The limiting ring (240) abuts against the rear end face of the outer shell (100) on one side. The first sealing groove (230) is provided with a first sealing ring (250).

5. The tip for a sandblasting handle according to claim 1, characterized in that: The outer casing (100) has a second sealing groove (140) in the axial direction of the central axis, which is opposite to the front and rear of the water guide hole (120), and a second sealing ring (150) is provided on the second sealing groove (140).

6. A sandblasting handle characterized by: Includes a dental air-blasting nozzle as described in any one of claims 1-5.

7. A sandblasting handle according to claim 6, wherein Also includes: The first core (500) has a hollow structure, with its front end sleeved on the rear end of the outer shell (100). The inner wall of the first core (500) has an annular channel (510) corresponding to the water guide hole (120). The rear diameter of the first core (500) is larger than the middle diameter, forming an annular step (520). The wall of the first core (500) has a water inlet channel (530) extending from the step surface of the annular step (520) to the annular channel (510). The second core (600) is inserted into the rear of the first core (500). The second core (600) has an air-sand input channel (610) and a water input channel (620). One end of the air-sand input channel (610) is connected to an external pipe that provides air and sand powder, and the other end is connected to the air-sand mixing pipe (200). One end of the water input channel (620) is connected to an external water supply pipe, and the other end is connected to the water inlet channel (530).

8. A sandblasting handle according to claim 7, characterized in that: The second core (600) has a snap-fit ​​part (630) protruding from the center of its front end face. The air-sand input channel (610) is located at the central axis of the second core (600). The snap-fit ​​part (630) is connected to the end of the air-sand mixing pipe (200) through the sealing sleeve (700) so that air and sand powder are sprayed out sequentially through the air-sand input channel (610), the sealing sleeve (700), the air-sand mixing pipe (200), the bend guide pipe (300), and the nozzle pipe (400).

9. A sandblasting handle according to claim 7, characterized in that: There is a gap between the front end face of the second core (600) and the step surface of the ring step (520) to form an annular water guiding channel (540). The water input channel (620) is offset from the central axis of the second core (600) and extends out of the front end face to communicate with the water guiding channel (540).

10. A sandblasting handle according to claim 9, characterized in that: The second core (600) has a third sealing groove (640) on the axial direction of the central axis, which is opposite to the front and rear of the water guiding channel (540), and a third sealing ring (650) is provided on the third sealing groove (640).

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