JP7098545B2 - Dental turbine handpiece - Google Patents

Description

The present invention relates to a dental turbine handpiece that rotates a cutting tool that cuts teeth using a turbine.

Conventionally, there is a dental turbine handpiece (hereinafter referred to as a handpiece) that obtains a rotational driving force of a cutting tool that cuts teeth by using air pressure.
For example, Patent Document 1 discloses a handpiece in which a turbine is provided inside the head and the turbine is rotated by air blown from a nozzle formed in the head to obtain a rotational driving force of a cutting tool (a handpiece). For example, Patent Document 1 (FIG. 1).

The handpiece disclosed in Patent Document 1 is provided with a nozzle inside the head, which communicates with an air supply pipe. This nozzle is configured by forming a pipe-shaped opening in a member constituting the head by cutting or the like. That is, the nozzle is integrated with the head.

Japanese Unexamined Patent Publication No. 2018-53806

However, in the case of the handpiece described in Patent Document 1, there is a problem that processing using a cutting machine becomes more difficult when forming a nozzle having a complicated shape in order to improve the air supply efficiency to the turbine. ..
Especially in the case of a dental handpiece, the head is compactly formed for use in the oral cavity. For this reason, it is difficult to form a nozzle having a complicated shape that matches the shape of the turbine inside the compactly formed head.

The present invention is for solving the above-mentioned problems, and an object of the present invention is to provide a handpiece capable of more efficiently obtaining a rotational driving force of a cutting tool.

In order to solve the problem, the dental turbine handpiece has a grip which is a part to be gripped by the user, a head connected to the tip of the grip, and a rotor provided in the head, and the rotor is supplied. It is equipped with a turbine that obtains rotational torque from air, and the head has an air supply hole that supplies air to the turbine, an exhaust hole that exhausts air inside the head, an air supply pipe that supplies air to the head, and an air supply pipe. A nozzle that is connected to blow air to the turbine is provided, and a step portion is formed inside the air supply hole. The nozzle is a component independent of the head, and a protruding portion is formed so as to surround the outer peripheral surface. , It may be configured so that it is inserted toward the front rather than the rear with respect to the air supply hole and is attached to the inside of the air supply hole by the protruding portion abutting on the step portion .

According to the present invention, it is possible to obtain a handpiece capable of efficiently obtaining the rotational driving force of a cutting tool.

(A) Side view of the dental handpiece H according to the embodiment (b) Perspective view of the dental handpiece H according to the embodiment. AA sectional view shown in FIG. 1 (a). BB sectional view shown in FIG. (A) A perspective view of the inside of the turbine chamber with the upper opening open according to the embodiment (b) A perspective view showing a state in which the turbine is arranged in the turbine chamber in the state of (b) (a). Perspective view of the turbine according to the embodiment CC sectional view shown in FIG. An exploded perspective view of the head case, nozzle, and air supply pipe of the dental handpiece according to the embodiment. FIG. 7 is a sectional view taken along the line DD shown in FIG.

(Embodiment)
The first embodiment will be described with reference to the drawings. In the figure, the head 20 is the front side, the grip 10 is the rear side, the direction in which the head 20 and the grip 10 are connected is the front-rear direction, and the direction orthogonal to the front-rear direction is the left-right direction. The front-back and left-right directions are based on the state in which the user holds the grip 10 and uses the handpiece H, and the user sees the handpiece H.

The dental handpiece H (hereinafter, handpiece H) shown in FIGS. 1 to 2 has a turbine 100 that is rotationally driven by supply air (hereinafter, air) supplied from the outside, and the driving force of the turbine 100. Then, the cutting tool 27 for cutting the teeth is rotated and used for dental treatment. Such a handpiece H has a grip 10 and a head 20 connected to the front end of the grip 10.
The air supplied to the handpiece H is adjusted by operating an air adjusting means such as a foot pedal (not shown) provided in the air flow path.

The outer shell of the grip 10 is formed by a cylindrical member, and is a portion to be gripped by the user. Further, a coupling 11 is connected to the rear end of the grip 10.
Inside the grip 10, an air supply pipe 12 for guiding the air supplied from the coupling 11 to the head 20 is provided. Further, the inside of the grip 10 becomes a flow path of air exhausted from the head 20. The exhaust air that has flowed inside the grip 10 flows into the coupling 11.

A cord 11a is connected to the rear end of the coupling 11. The coupling 11 is a portion serving as a connector for connecting the handpiece H and the cord 11a side. The code 11a serves as a flow path through which air supplied from an external device to the handpiece H and air exhausted from the head 20, which will be described later, flow.
As shown in FIG. 2, the air supply pipe 12 is a pipe-shaped member that forms a flow path through which air supplied to the inside flows. The air supplied from the cord 11a is supplied to the head 20 side by the air supply pipe 12 through the inside of the grip 10.
A nozzle 13 is attached to the tip of the air supply pipe 12. The nozzle 13 is a portion for injecting air flowing from the air supply pipe 12 toward the turbine 100, which will be described later.

Next, as shown in FIGS. 2 to 4, the outer shell portion of the head 20 has a head case 21, a head cap 28, and a push button 22. The head case 21 has a substantially cylindrical portion and a connecting portion 40 projecting rearward from the cylindrical portion, and a turbine chamber 200 is formed therein to hold each functional component described later.
The connecting portion 40 is a portion that connects the grip 10 and the head 20. By fitting the grip 10 into the connecting portion 40, the head case 21 and the grip 10 are integrated.

Further, the portion of the head case 21 on the side where the connecting portion 40 is located is formed with a recess 41 that is recessed from the turbine chamber 200 side toward the rear.
Inside the recess 41, an air supply hole 42 and an exhaust hole 43, which are communication holes connecting the inside of the head 20 and the inside of the grip 10, are formed. Inside the air supply hole 42, an air supply pipe 12 and a nozzle 13 attached to the air supply pipe 12 are provided. Further, the exhaust hole 43 opens toward the inside of the grip 10 which is a flow path of the exhaust air.

As described above, the air supply hole 42 is provided with the nozzle 13 connected to the air supply pipe 12, and the exhaust hole 43 is open toward the inside of the grip 10 which is the flow path of the exhaust air. Air can be supplied to the inside of the head 20 from the outside, and air can be discharged from the inside of the head 20. In particular, the recess 41 is an exhaust groove that guides exhaust air from the turbine chamber 200 to the exhaust hole 43.

Next, as shown in FIG. 3, a head cap 28 is provided in the upper opening 20a that opens upward of the head case 21 so as to cover the opening. A push button 22 is provided on the upper side of the head cap 28.
Further, a chuck mechanism 26 for holding the cutting tool 27 is located below the push button 22. The push button 22 is connected to the chuck mechanism 26. By pressing the push button 22, the chuck mechanism 26 opens and closes.
The push button 22 configured in this way has a function as a release button of the chuck mechanism 26 when the cutting tool 27 is removed. By opening and closing the chuck mechanism 26, the cutting tool 27 is configured to be detachable from the head 20.

Inside the head 20, each functional component includes a rotary cylinder 24, a bearing 25 (upper bearing 25a, lower bearing 25b), a chuck mechanism 26, a cutting tool 27, a turbine 100, and elements for holding these portions.
The rotary cylinder 24 is a cylindrical member that opens downward. The chuck mechanism 26 is provided inside the rotary cylinder 24 and holds the cutting tool 27 in a detachable manner. The opening of the rotary cylinder 24 is a mounting opening 24a for mounting the cutting tool 27 on the chuck mechanism 26.

As shown in FIGS. 2 and 5, the turbine 100 has a hub 110 and a turbine blade 120. The hub 110 is located at the center of rotation of the turbine 100, and a mounting opening 111 that opens in the axial direction is formed in the central portion.
A plurality of turbine blades 120 are provided so as to extend radially from the periphery of the hub 110. The turbine blade 120 has a concave shape that opens in the direction opposite to the rotation direction of the turbine 100 when viewed from the radial direction of the turbine 100.
The concave shape of the turbine 100 of the present embodiment has a smooth curved shape. For example, it has a shape similar to the Roman letter "C" or a shape in which the Roman letter "U" is tilted in the direction opposite to the direction of rotation. This concave portion becomes an air receiving surface 121 that receives the supplied air.

In such a turbine blade 120, air enters the inside of the concave shape from the upper region, the air flows along the air receiving surface 121 and changes its direction, and from the lower region to the outside of the concave portion. Flows.
By supplying air to the turbine blades 120 in this way, the pressure of the air acts on the air receiving surface 121 of the individual turbine blades 120 to become the rotational driving force of the turbine 100.
Then, in the turbine 100, by fixing the rotary cylinder 24 to the mounting opening 111, the turbine 100 and the rotary cylinder 24 are integrally rotated by the supplied air. The cutting tool 27 projects downward from the head 20 and rotates together with the rotary cylinder 24 while being held by the chuck mechanism 26. The bearing 25 rotatably holds the rotary cylinder 24.

Hereinafter, each functional component inside the head 20 will be described.
As shown in FIG. 3, an upper bearing 25a and a lower bearing 25b are provided inside the head case 21.
An O-ring 25c is provided between the outer ring (outer race) of the upper bearing 25a and the head cap 28 fixed to the head case 21. Similarly, an O-ring 25d is provided between the outer ring of the lower bearing 25b and the head case 21.

In this way, the upper bearing 25a and the lower bearing 25b are provided between the head case 21 side and the O-rings 25c and 25d, respectively, and are fixed to the head case 21 side.
Further, the upper bearing 25a and the lower bearing 25b are located separately on the upper side and the lower side, respectively. A turbine chamber 200, which is a space in which the turbine 100 is rotatably located, is formed between the upper bearing 25a and the lower bearing 25b located apart from each other.
The turbine chamber 200 is a space having a substantially cylindrical shape that matches the shape of the turbine 100. Further, the air supply hole 42 and the exhaust hole 43 are opened toward the turbine chamber 200.

Next, the rotary cylinder 24 is rotatably provided on the bearing 25. That is, the rotary cylinder 24 is provided in a state of penetrating the inner opening of the inner ring (inner race) of each bearing so as to extend from above the upper bearing 25a to the lower 25b of the lower bearing.
As a result, the rotary cylinder 24 rotates together with the inner ring of the upper bearing 25a and the inner ring of the lower bearing 25b. The mounting opening 24a of the rotary cylinder 24 opens downward.

Next, a chuck mechanism 26 is provided inside the rotary cylinder 24. The chuck mechanism 26 detachably holds the cutting tool 27 inserted from the mounting opening 24a.
When the cutting tool 27 is attached to the chuck mechanism 26, the chuck mechanism 26 is in a state where the cutting tool 27 can be accepted by pressing the push button 22. That is, the cutting tool 27 can be attached to the head 20.

If the push button 22 is stopped while the cutting tool 27 is inserted inside the chuck mechanism 26, the chuck mechanism 26 closes and the cutting tool 27 is held. As a result, the cutting tool 27 is held by the head 20, and the cutting tool 27 rotates together with the rotary cylinder 24.
When the cutting tool 27 is removed from the chuck mechanism 26, the holding state of the cutting tool 27 of the chuck mechanism 26 is released by pressing the push button 22, and the cutting tool 27 can be removed from the chuck mechanism 26.

Next, the turbine 100 is provided on the outer peripheral portion of the rotary cylinder 24. The turbine 100 has a plurality of turbine blades and can rotate integrally with the rotary cylinder 24. The turbine 100 is located in the turbine chamber 200 inside the head case 21.
Therefore, the turbine 100 rotates in the turbine chamber 200 when the air supplied from the air supply pipe 12 is blown from the nozzle 13 to the turbine blade 101.

In this way, the rotor 160 is formed by the rotary cylinder 24 having the chuck mechanism 26 inside and the turbine 100. The rotor 160 is rotatably provided inside the head case 21. By blowing the air supplied from the air supply hole 42 to the turbine 100, a rotational driving force is generated in the rotor 160.
As a result, the rotor 160 rotates, and the cutting tool 27 held by the chuck mechanism 26 inside the rotary cylinder 24 also rotates.

Then, the air imparting the rotational driving force to the rotor 160 exits the inside of the head 20 from the exhaust hole 43, passes through the inside of the grip 10 and the coupling 11, and is exhausted to the outside of the handpiece H. In the case of this embodiment, when the head 20 is viewed from above, the rotor 160 rotates clockwise.
By configuring each part of the handpiece H as described above, it is possible to rotate the cutting tool 27 to cut a treatment target such as a tooth.

(Main part of this embodiment)
Next, with reference to FIGS. 2 and 4, the recess 41 formed inside the head 20, which is the main part of the present embodiment, will be described in detail.
The concave portion 41 is a portion formed on the inner wall on the rear side of the head case 21 and is a portion to be recessed rearward. Inside the recess 41, an air supply hole 42 and an exhaust hole 43, which are communication holes connecting the inside of the head 20 and the inside of the grip 10, are formed.
Further, the recess 41 is opened so as to spread along the periphery of the turbine chamber 200. In the case of the present embodiment, the recess 41 is formed over a region extending from the position on the right side of the exhaust hole 43 to the left side of the air supply hole 42. The left and right widths of the recess 41 are wider than the left and right widths of the connecting portion 40.

Next, the exhaust hole 43 is provided at a position including the central portion of the recess 41, and is open toward the internal space of the grip 10. As a result, the air exhausted from the turbine chamber 200 flows into the exhaust hole 43 and reaches the inside of the grip 10, reaches the coupling 11 from the inside of the grip 10, and reaches the cord 11a, whereby the handpiece H Can be exhausted to the outside of.
The connection surface 44 between the opening edge 41a of the recess 41 to the turbine chamber 200 and the exhaust opening edge 43a of the exhaust hole 43 is configured to have a smooth curved surface.

Next, as shown in FIGS. 2 and 8, the air supply hole 42 is a pipe-shaped communication hole extending substantially parallel to the tangential direction of the rotation circle drawn by the rotation of the turbine 100.
Inside the air supply hole 42, a step portion 42a is formed by making the inner diameter on the rear side larger than the inner diameter on the front side. The air supply hole 42 is provided with a nozzle 13 so as to penetrate the communication hole. That is, the tip of the nozzle 13 projects from the air supply hole 42 into the recess 41.
The nozzle 13 has a cylindrical shape, and is configured such that the inner diameter of the nozzle 13 decreases toward the tip at the tip portion. That is, the nozzle 13 has a narrowed shape toward the outlet 13a from which air is blown out. Further, a protrusion 13b is formed on the outer peripheral surface of the nozzle 13 so as to surround the outer peripheral surface.

When the nozzle 13 is inserted and attached to the air supply hole 42 from the rear to the front, the protruding portion 13b abuts on the step portion 42a formed inside the air supply hole 42 with respect to the air supply hole 42. It is a part that determines the position of the nozzle 13. As a result, the outlet 13a of the nozzle 13 can be positioned correctly with respect to the turbine blade 120.
Further, the protruding portion 13b is a portion that determines the position of the nozzle 13 with respect to the air supply pipe 12 by abutting the tip opening 12a of the air supply pipe 12 when the nozzle 13 is press-fitted into the inside of the air supply pipe 12. Become.
By attaching the nozzle 13 in this way, the air outlet 13a is located on the front side of the opening of the exhaust hole 43. Then, a space is formed around the nozzle 13 inside the recess 41.

Here, the positional relationship between the nozzle 13 and the exhaust hole 43 will be described with reference to FIGS. 2 and 4.
The nozzle 13 is a member formed in a cylindrical shape, and the exhaust hole 43 is a straight pipe-shaped hole, both of which extend straight.
The nozzle 13 and the exhaust hole 43 are inclined diagonally and extend in the front-rear direction with respect to the virtual straight line L extending in the front-rear direction of the handpiece H. In the case of the present embodiment, the nozzle 13 and the exhaust hole 43 are tilted so that the front portion is closer to the left side with respect to the rear portion.
The virtual straight line L is, for example, a straight line parallel to the alternate long and short dash line showing the BB cross section. The alternate long and short dash line showing the BB cross section is a line passing through the left and right centers of the handpiece H.

Further, the exhaust holes 34 are arranged closer to the side where the nozzle 13 is located. That is, the exhaust hole 34 is arranged so as to extend from the left and right center of the handpiece H to the left side region where the nozzle 13 is located. The opening of the exhaust hole 34 is located inside the recess 41 so as to straddle the center position.
Further, the exhaust hole 43 is opened at a substantially central position of the recess 41. The nozzle 13 is provided on the left side of the exhaust hole 43 in a state where the air outlet 13a is projected from the air supply hole 42 opened on the upper side in the vertical direction of the recess 41. That is, the outlet 13a of the nozzle 13 is located on the left side in the recess 41, and is open toward the turbine blade 120 at a position in front of the opening of the exhaust hole 43.
The exhaust hole 43 and the nozzle 13 are provided in the head case 21 in a state where the exhaust hole 43 is parallel to each other or the exhaust hole 43 is tilted with respect to the nozzle 13 so that the front side of the exhaust hole 43 approaches the nozzle 13. That is, the exhaust hole 43 is arranged so as to approach the nozzle 13 as it approaches the front side.

The present embodiment in which each part is configured as described above exhibits the following actions and effects.
First, when the user operates the air adjusting means to start supplying air to the handpiece H, the supply air flows into the air supply pipe 12, and the supply air flows from the outlet 13a of the nozzle 13 toward the turbine 100. Blow out. The air blown from the nozzle 13 collides with the turbine blade 120 and rotates the turbine 100. As a result, the rotor 160 is rotationally driven, and the rotating cutting tool 27 can cut the treatment site.

Here, the air after hitting the turbine blade 120 and applying the rotational driving force of the turbine 100 is discharged from the inside of the head 20 as follows.

(A) Air that rotates and moves in the turbine chamber 200 together with the turbine 100 The air that rotates and moves in the turbine chamber 200 together with the turbine 100 is sandwiched between the turbine blades 120 that are adjacent to each other in the front-rear direction, and as the turbine 100 rotates, the air moves. It moves along the inner wall of the head case 21.
Then, the air that has rotated and moved together with the turbine 100 enters the inside of the recess 41 from the right side of the recess 41 and flows into the exhaust hole 43. The air that has flowed into the exhaust hole 43 reaches the coupling 11 from the inside of the grip 10 and is exhausted to the outside of the handpiece H.

As described above, since the recess 41 is configured inside the head case 21 to reach the region on the right side away from the nozzle 13, the air that rotationally moves in the turbine chamber 200 together with the turbine 100 passes through the exhaust hole 43. It is easy to enter the recess 41 from the position on the right side of the pinch and flow into the exhaust hole 43.
As a result, air can be efficiently exhausted from the inside of the turbine chamber 200, so that it is difficult to obstruct the flow of air newly blown from the nozzle 13 to the inside of the turbine chamber 200.

(B) Air bounced off the turbine blade 120 toward the vicinity of the nozzle 13 Since the nozzle 13 protrudes into the recess 41 as in the present embodiment, the outlet 13a should be brought closer to the turbine blade 120. At the same time, a space is secured around the nozzle 13 for the air bounced off from the turbine blade 120 to flow. That is, the space around the nozzle 13 inside the recess 41 is a space in which the flow of air bounced off from the turbine blade 120 can enter.

Therefore, air can be efficiently supplied to the turbine blade 120, and the air that has been bounced off to the nozzle 13 side by applying a rotational driving force to the turbine blade 120 is transferred from the recess 41 around the nozzle 13 to the exhaust hole 43. Can be shed. As a result, it is possible to alleviate an increase in the pressure of the air around the outlet 13a and alleviate the difficulty of blowing air from the outlet 13a.
In particular, since the recess 41 is formed up to the portion extending to the left side of the nozzle 13, a part of the air that has applied the rotational driving force to the turbine 100 easily flows into the exhaust hole 43.

Further, since the inner diameter of the nozzle 13 is configured to become smaller toward the tip, the air blown from the nozzle 13 is unlikely to diffuse to the turbine blade 120. As a result, air can be centrally supplied to the region above the air receiving surface 121 of the turbine blade 120.
Then, the air supplied to the turbine blade 120 flows along the air receiving surface 121, turns in a direction away from the air receiving surface 121, and separates from the air receiving surface 121 from the lower region of the air receiving surface 121. Flow like.

As a result, the air away from the air receiving surface 121 and the flow of air newly supplied to the air receiving surface 121 are less likely to interfere with each other. In particular, the air supplied toward the upper side of the air receiving surface 121 is less likely to spread due to the shape of the nozzle 13, so that it is less likely to interfere with the air flow returning from the lower side of the air receiving surface 121 to the nozzle 13 side.
Therefore, air can be more efficiently supplied to the turbine 100 from the nozzle 13, and the rotational output of the rotor 160 can be improved.

Further, the nozzle 13 is a component attached as a separate component to the air supply hole 42 formed in the head case 21. That is, it is composed of parts independent of the head case 21.
With such a configuration, it is not necessary to process a complicated nozzle shape for the head case 21, so that the processing difficulty of the head case 21 can be reduced. In particular, a complicated shape in which the nozzle 13 protrudes inside the recess 41 of the head case 21 can be easily formed as compared with the case where the nozzle 13 is formed by cutting or the like.

Further, since the nozzle 13 is an independent component, it is possible to facilitate the processing when the nozzle 13 is formed from a material by cutting with a machine tool. For example, by making the nozzle 13 a simple cylindrical shape, it becomes possible to perform machining that requires precision by cutting, and machining can be easily performed, and productivity is improved.
Further, the shape of the nozzle 13 to be used can be easily selected according to the characteristics of the turbine 100. That is, by appropriately combining turbines 100 and nozzles having various shapes, it is possible to easily increase the product lineup of handpieces having various characteristics in which the head case 21 and the handle 10 are common.

Further, when the nozzle 13 is formed by machining, it can be performed from the ejection port side of the nozzle 13, so that the degree of freedom of machining can be increased. By increasing the degree of freedom in processing, for example, the shape of the nozzle 13 can be changed to a Laval nozzle shape that produces a supersonic flow.
Such an air turbine is called an impulse turbine, and the impulse force of air is the source of rotational force. Since this impulsive force is proportional to the square of the flow velocity, the larger the flow velocity injected from the nozzle 13, the higher the torque and the rotational speed, and the higher the efficiency. That is, if a supersonic flow can be obtained, the rotational output of the rotor 160 can be improved.

Further, the nozzle 13 configured in this way is inserted into the air supply hole 42 from the rear toward the front, and the protruding portion 13b is brought into contact with the step portion 42a formed inside the air supply hole 42 to supply the air. It is attached inside the pore 42.
In this way, since the nozzle 13 is attached so as to be fixed in position with respect to the flow direction of the supply air, the nozzle 13 is pressed against the step portion 42a by the pressure of the air to be supplied, and the air supply hole 42 is pressed. The nozzle 13 does not shift or fall out of the air supply hole 42 inside the air supply hole 42.

Further, the air flowing through the turbine chamber 200 together with the rotating turbine 100 enters the inside of the recess 41 from the right side of the recess 41 and flows into the exhaust hole 43. Since the exhaust holes 43 are arranged closer to the nozzle 13 side as in the present embodiment, the exhaust holes 43 enter the inside of the recess 41 from the right side of the recess 41 and reach the exhaust hole 43 of the air flowing into the exhaust hole 43. The distance can be increased.
As a result, it is possible to suppress the flow of air directly flowing to the exhaust hole 43 so that the rotation speed of the turbine 100 does not become too high, and to increase the rotation torque.

Further, by tilting the exhaust hole 43 parallel to the nozzle 13 or diagonally with respect to the nozzle 13 so that the front side of the exhaust hole 43 approaches the nozzle, the opening of the exhaust hole 43 is blown out from the nozzle 13. The supplied air supply air can be directed to a position where it hits the turbine 100.
As a result, the exhaust hole 43 is arranged closer to the nozzle 13 side, and the air rebounding from the turbine 100 to the nozzle 13 side can be easily guided to the exhaust hole 43.
In particular, the air flowing through the turbine chamber 200 rotating with the turbine 100 enters the inside of the recess 41 from the right side of the recess 41, and the distance to the exhaust hole 43 flowing to the exhaust hole 43 becomes long. The flow of air flowing through the turbine can be suppressed. As a result, the air flowing from the turbine 100 to the periphery of the rebound nozzle 13 can be easily guided to the exhaust hole 43.

By configuring the handpiece H as described above, the air after applying the rotational driving force to the turbine 100 can be efficiently discharged to the outside of the head. As a result, the air supply efficiency of the air supplied into the head is improved, and the rotational output of the rotor 160 for rotating the cutting tool can be improved.

H Handpiece 10 Grip 11 Coupling 11a Code 12 Air supply pipe 13 Nozzle 13a Outlet 20 Head 21 Head case 22 Push button 24 Rotating cylinder 24a Mounting opening 25 Bearing 25a Upper bearing 25b Lower bearing 25c O-ring 26 Chuck mechanism 27 Cutting tool 28 Head cap 40 Connecting part 41 Recession 41a Opening edge 42 Air supply hole 42a Stepped part 43 Exhaust hole 43a Exhaust opening edge 44 Connection surface 100 Turbine 110 Hub 111 Mounting opening 120 Turbine blade 121 Air receiving surface

Claims (3)

It has a grip that is a part to be gripped by the user, a head connected to the tip of the grip, and a rotor provided in the head.
The rotor includes a turbine that obtains rotational torque from the supplied air.
The head is connected to the turbine by connecting an air supply hole for supplying air to the turbine, an exhaust hole for exhausting air inside the head, an air supply pipe for supplying air to the head, and the air supply pipe. It is equipped with a nozzle that blows out air, and a step is formed inside the air supply hole.
The nozzle is a component independent of the head, and a protrusion is formed so as to surround the outer peripheral surface , and the nozzle is inserted into the air supply hole from the rear to the front, and the protrusion is formed in the step. A dental turbine handpiece characterized in that it is attached to the inside of the air supply hole by abutting . The air supply hole and the exhaust hole are provided inside a recess formed in the head.
The dental turbine handpiece according to claim 1, wherein the nozzle protrudes from the air supply hole into the recess. The dental turbine handpiece according to claim 2, wherein the inner diameter of the nozzle becomes smaller toward the tip.

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