JP5779760B2 - Compressed air flow control device for compressed air driven dental handpiece - Google Patents

Description

  The present invention relates to a flow control device, and more particularly to a compressed air flow control device for a compressed air-driven dental handpiece.

The compressed air-driven dental handpiece includes an air turbine handpiece having an air turbine as a dental tool drive source, a dental scaler or a root canal treatment handpiece having a vibrator as a dental tool drive source, Etc.
During dental treatment, it is desirable that the rotational speed of the air turbine, the output of the vibrator, and / or the vibration frequency can be variably controlled at the handpiece according to the state of the treatment.

Various flow control devices are known in the prior art for adjusting the output and / or frequency of the drive source of a compressed air driven dental handpiece.
For example, Japanese Patent Laid-Open No. 2004-351086 proposes an exhaust adjustment mechanism that can control the output of the handpiece drive unit by adjusting the opening of the exhaust circuit. The exhaust adjustment mechanism includes a valve seat portion provided in the exhaust circuit and provided with a valve opening, a valve body provided with a notch for adjusting the opening degree of the valve opening, and an operation ring integrally formed with the valve body. And.
In this exhaust adjustment mechanism, since the opening degree of the exhaust circuit is determined by the overlap between the valve opening and the valve body notch, an initial setting of the opening degree is necessary (refer to claim 5). There is a problem of having to make adjustments. Furthermore, since the valve body with a notch for adjusting the opening is formed integrally with the operation ring, it is difficult to machine the notch, and the exhaust flow rate and thus the drive unit output for each manufactured exhaust adjustment mechanism. There is a risk of variation.

  Japanese Patent Laid-Open No. 2000-5192 discloses a flow rate adjusting device in which a recess is formed in the circumferential direction in the flow rate adjusting ring so that the air introduction and the opening of the supply path gradually decrease as the flow rate adjusting ring rotates. ing. Also in this handpiece, the flow adjustment recess is formed directly in the flow adjustment ring, so it is difficult to machine the flow adjustment recess, and it is also necessary to adjust the flow rate when assembling each handpiece. It becomes.

  In Japanese Patent Publication No. 7-16497 and Japanese Patent Application Laid-Open No. 2010-51343, a spool valve is disposed in a cylindrical valve chamber forming a part of a compressed air supply passage, and the spool valve is displaced in the axial direction to thereby generate a compressed air flow rate. There is disclosed a flow control valve device adapted to adjust the flow rate. In this flow control valve device, the flow rate varies greatly due to slight variations in clearance that must be provided between the inner diameter of the valve chamber and the outer diameter of the spool valve. There is a problem that adjustment is required and the yield of the spool valve is reduced.

An object of the present invention is to provide a compressed air flow regulating device for a compressed air driven dental handpiece capable of solving the above-mentioned problems of the prior art.
Another object of the present invention is to provide a compressed air flow control device for a compressed air driven dental handpiece having a structure that does not require the flow rate to be adjusted every time the handpiece is assembled.
Another object of the present invention is that the flow control valve can be machined with high precision by machining such as NC machining, and the compressed air drive does not cause variations in the compressed air flow rate between products. It is to provide a compressed air flow control device for a dental handpiece.
Still another object of the present invention is that the degree of opening of the compressed air flow path is not determined by the overlap between the valve opening of the valve seat and the cutout of the valve body, but by the depth of the flow adjustment notch provided in the flow adjustment valve body. Compressed air flow control valve for compressed air-driven dental handpieces that can eliminate the need to adjust the flow rate during handpiece assembly as long as the cut-out depth is precisely machined as a result To provide an apparatus.

The present invention relates to a flow control device for controlling the flow rate of compressed air supplied to a drive unit in a dental handpiece having a dental tool drive unit driven by compressed air so as to control the output of the drive unit. Is to provide.
This flow control device is: a valve body having a valve seat formed across a compressed air supply passage (a valve chamber forms a part thereof) for supplying compressed air to a drive unit, and is compressed downstream of the valve seat An outlet opening to the air supply passage formed in the valve seat; a sliding valve body that is slidably in close contact with the valve seat and variably controls the flow rate of the compressed air supplied from the outlet opening to the drive unit; A manually operated member for displacing the sliding valve body over a predetermined stroke; the sliding valve body is a notch facing the outlet opening and has a length at least equal to the stroke parallel to the direction of displacement; The notch depth D measured from the face of the valve seat changes from one end to the other end in the length direction of the notch, and the notch has the maximum depth D. The end portion on the side to be communicated with the compressed air supply passage upstream of the valve seat, That.

With this configuration, the flow rate is determined by the depth D of the notch formed in the sliding valve body, while the depth D of the notch is precisely machined as designed by machining such as NC machining. Therefore, the compressed air flow rate does not vary from product to product. Therefore, it is not necessary to adjust the flow rate when assembling the handpiece.
Furthermore, since the sliding valve body is processed as a separate part from the manual operation member, the machining of the notch of the sliding valve body can be performed easily and with high accuracy, which also eliminates the variation in flow rate. Contribute.

In a preferred embodiment, the notch of the sliding valve body is formed by a plurality of sections (for example, three stages) where the counterbore depth D changes stepwise by machining such as milling.
In this way, as long as the counterbore depth D of each section is precisely machined, there is no variation in the flow rate for each product, so it becomes possible to eliminate the need for flow rate adjustment during handpiece assembly. .

  In a specific embodiment, the valve body has a generally cylindrical shape with an axial cavity coaxial with the handpiece, the valve body having a first circumferential divergence angle and a truncated fan shape. A valve chamber having an axial cross section is formed, the valve chamber forms part of the compressed air supply passage, and the sliding valve body has a second circumferential expansion angle smaller than the first circumferential expansion angle. And has a fan-shaped axial cross section and is fitted in the valve chamber so as to be slidable in the circumferential direction. The notch faces the outlet opening while the sliding valve body slides in the circumferential direction. The manual operation member is formed of a manual operation ring that is airtightly and rotatably mounted around the valve body.

Preferably, the sliding valve body is elastically pressed against the valve seat by a spring-biased steel ball. Therefore, the flow rate of the flow regulating device is stabilized. The steel ball also acts as an alignment lock ball by snap-engaging with any of a plurality of spaced alignment recesses formed on the surface of the sliding valve body opposite the valve seat.
According to this configuration, the spring that urges the sliding valve body toward the valve seat and the spring that presses the ball can be shared, so that the structure can be simplified and the cost can be reduced.

In a preferred embodiment, the sliding valve body is formed by machining three disc-shaped blanks in the circumferential direction and then cutting them into three at equal angular intervals.
If a sliding valve body is manufactured by machining three parts at a time by cutting three pieces in this way and then cutting them into three parts, the time and cost required for manufacturing while machining the sliding valve body with high precision Can be reduced.

The present invention also provides a flow control device for controlling the flow rate of fluid flowing through a fluid supply line, the flow control device comprising:
A valve body having a valve seat formed across the fluid supply line, the valve seat having an outlet opening to the fluid supply line downstream of the valve seat;
A sliding valve body slidably in contact with the valve seat and variably controlling the flow rate of the fluid;
An operating member for displacing the sliding valve body over a predetermined stroke;
The sliding valve body has a notch facing the outlet opening and extending in a direction parallel to the direction of the displacement over a length at least equal to the stroke, and the depth of the notch measured from the surface of the valve seat. The length D changes as it goes from one end to the other in the length direction of the notch, and the notch communicates with the fluid supply pipe upstream of the valve seat at the end where the depth D is maximum. It is characterized by.
Other features and advantages of the present invention will become apparent from the description of the following examples.

FIG. 2 is a partially cutaway side view of a dental handpiece and dental hose joint in the form of a compressed air driven vibratory scaler with a flow regulating device of the present invention. FIG. 2 is an enlarged perspective view of the flow control device shown in FIG. 1, in which a part of the operation ring is notched and the sliding valve body is taken out of the valve chamber for easy understanding; In order to show the notch formed, the sliding valve body is shown to be rotated 90 ° about the vertical axis Z. It is a perspective view which shows the place which machined the sliding valve body shown in FIG. 2 by three pieces. It is a perspective view which shows three different positions of the flow control valve apparatus shown in FIG. FIG. 5 is a cross-sectional view taken along the line V-V in FIG. 2, and corresponds to three positions of the flow valve device shown in FIG. 4. FIG. 2 is a side view showing the flow control device of the present invention incorporated into a dental handpiece in the form of an air turbine handpiece.

Referring to FIG. 1 showing the flow control device of the present invention incorporated into a dental handpiece in the form of a compressed air driven vibratory scaler, the dental handpiece 10 is an elongated hollow handle that can be grasped by hand. 12 is provided. For convenience of manufacture and assembly, the handle 12 is divided into a plurality of sections, for example, three sections in the longitudinal direction, and these sections are screwed together.
Inside the handle 12, a compressed air dynamic vibrator 16 as a vibration source for exciting a scaler tip 14 as a dental tool is supported by an appropriate number of O-rings (shown by hatching in FIG. 1).
The vibrator 16 can be the one described in FIGS. 3 and 4 of US Pat. No. 4,453,919, the disclosure of which is incorporated herein, and a detailed description of the vibrator 16 is omitted. As shown in FIG. 4 of the above-mentioned U.S. Patent, the vibrator 16 includes a vibrator casing 18 that defines a vibration chamber that houses a disk-shaped vibrator, and swivels when compressed air is blown in a tangential direction into the vibration chamber. The vibrator excited by the flow strikes the side wall of the vibration chamber to generate vibration. It is also possible to use the vibrator described in US Reissue Patent No. Re29,687 and other types of compressed air dynamic vibrators.

An axial hole 24 is formed in the rear part of the handle 12 for inserting a tip insertion part 23 of a male joint 22 attached to the front end of the dental hose 20. When the handpiece 10 is connected to the dental hose 20 by inserting the tip insertion portion of the male joint 22 into the shaft hole 24, compressed air as a drive medium is applied to the handpiece 10 from a dental unit (not shown) via a foot switch. And cooling wash water can be supplied. The handpiece 10 is detachably connected to the male joint 22 by a known one-touch type ball lock mechanism 26, 28.
The compressed air is supplied to the vibrator 16 through a compressed air supply port 30 of the distal end insertion portion 23 of the male joint 22 and a compressed air supply passage 32 in the handle 12. And is injected into a vibration chamber (not shown) of the vibrator 16 through a plurality of compressed air inlet ports 36 pierced in a tangential direction in the vibrator casing 18 to generate a swirling flow in the vibration chamber, thereby generating a vibrator. (Not shown) is excited to generate vibration. The generated vibration is transmitted to a hollow output shaft 38 integrally formed with the vibrator 16, and the tip of the scaler chip 14 attached to the output shaft 38 is caused to move elliptically, thereby removing the tartar by acting on the teeth.

  The cooling cleaning water from the dental unit is supplied to the cooling cleaning water supply port 40 of the tip insertion portion 23 of the male joint 22, the cooling cleaning water supply passage 42 in the handle 12, and the water supply pipe 44 that penetrates the vibrator casing 18 in the axial direction. The cooling cleaning water supply passage 46 formed in the output shaft 38 of the vibrator 16 and the cooling cleaning water supply passage 48 formed in the scaler tip 14 are supplied to the scaler tip 14 and are supplied to the treated portion during the dental treatment. To cool the teeth and the scaler chip 14 and to wash away the fragments and tartar.

  As shown in FIG. 1, a flow regulating valve 50 that controls the flow rate of the compressed air supplied from the compressed air supply port 30 of the distal end insertion portion 23 of the male joint 22 to the vibrator 16 is incorporated in the rear portion of the handle 12. Thus, the output of the vibrator 16 is controlled in accordance with a user operation.

  Referring to the enlarged view of FIG. 2, the flow control device 50 includes a substantially cylindrical valve body 52 in which an axial hole 24 for receiving the insertion portion 23 of the male joint 22 is formed. This valve body 52 forms part of the hollow handle 12 of the handpiece. The valve body 52 is formed with a valve chamber 54 having a truncated fan-shaped cross section having a circumferential expansion of about 180 °, for example. The valve chamber 54 forms part of the compressed air supply passage 32 (FIG. 1). The front end wall 56 of the valve chamber 54 defines a valve seat, the face of which is perpendicular to the axis of the handpiece. An outlet opening 60 to the compressed air supply passage 58 is formed in the valve seat 56.

  In the valve chamber 54, a sliding valve body 62 having a truncated fan-shaped cross section is fitted so as to be displaceable in the circumferential direction. In order to simplify the drawing, FIG. 2 shows the sliding valve element 62 taken out from the valve chamber 54. Since the sliding valve element 62 has an expansion of, for example, about 90 ° smaller than the expansion of the valve chamber 54, the sliding valve element 62 can be rotated in the valve chamber 54 over a stroke having a rotation angle of about 90 °. it can.

With reference to the enlarged view of FIG. 3, the geometric configuration of the sliding valve body 62 and a preferred manufacturing method will be described.
The sliding valve body 62 can be manufactured by machining three disc-shaped blanks 64 in the circumferential direction and then cutting the runner 65 and cutting it into three at equal angular intervals.
The front end surface of each sliding valve body 62 that contacts the valve seat 56 is circumferentially arranged so as to face the outlet opening 60 of the valve seat 56 through the rotation of the sliding valve body 62 in the valve chamber 54. A notch 66 extending in the shape of an arc is formed at the top.

The notch 66 can be machined by pressing the end mill of an NC control milling machine against the blank 64 in parallel with the axis of the blank 64. In this embodiment, the notch 66 has three stages as shown in FIG. By connecting counterbore holes 66A, 66B, 66C having counterbore depths D ₁ , D ₂ , D ₃ , they are formed into a generally elongated arc shape. The counterbore depths D ₁ , D ₂ , and D ₃ of the counterbore holes 66A, 66B, and 66C can be managed with high accuracy by NC control milling, so that the counterbore depth varies from product to product. There is no.
A notch 66 connected in a circular arc shape is formed by counter boring a plurality of times (twice in the illustrated example) while shifting the end mill in the circumferential direction for each of the depths D ₁ , D ₂ , and D _3. The Countersunk hole 66C of the depth D ₃ in the illustrated embodiment is excised inner circumferential wall of the sliding valve member 62 by displacing in radial direction inwardly an end mill, but leaving the inner peripheral wall of the sliding valve member 62 You may keep it. A counterbore 66 </ b> C having a depth D <b> ₃ opens in one radial end face 68 of the sliding valve body 62.
Each sliding valve body 62 is fitted with a concave groove 70 for fitting a connecting pin (indicated by reference numeral 72 in FIGS. 1 and 2) for connecting an operation ring, which will be described later, and the sliding valve body 62. Is formed.

Referring to FIG. 2 again, FIG. 2 shows the final product of the sliding valve body 62 manufactured by cutting the intermediate product shown in FIG. 3 into three parts. In FIG. 2, the sliding valve body 62 is taken out from the valve chamber 54, but the sliding valve body 62 is formed in the valve body 52 of the flow regulating valve device 50 as indicated by a one-dot chain line. Fitted inside.
A compressed air inlet 74 is perforated in the valve body 52 so as to open radially outward in the valve chamber 54. The compressed air inlet 74 has an axial position equal to the axial position of the compressed air supply port 30 of the insertion portion 23 when the insertion portion 23 of the male joint 22 of the dental hose 20 is inserted into the axial hole 24. Is formed. A concave groove is provided on the inner peripheral surface of the valve body 52 so that the compressed air supply port 30 communicates with the compressed air inlet 74 regardless of the rotation angle position of the male joint 22. Therefore, when the insertion part 23 of the male joint 22 of the dental hose 20 is inserted into the axial hole 24 and the foot switch of the compressed air circuit is opened, the compressed air is introduced into the valve chamber 54 from the compressed air inlet 74.

  An operation ring 76 is rotatably mounted on the outer periphery of the valve body 52 so as to surround the valve chamber 54. A pair of O-rings 78 and 80 are mounted in the groove formed on the outer peripheral surface in the vicinity of both ends of the valve body 52, and seals between the outer peripheral surface of the valve main body 52 and the inner peripheral surface of the operation ring 76. ing. Since the valve chamber 54 is thus sealed, the flow rate of the compressed air introduced from the compressed air inlet 74 into the valve chamber 54 is adjusted by the sliding valve element 62 as will be described later with reference to FIGS. Thereafter, the air flows out from the outlet opening 60 of the valve seat 56 to the compressed air supply passage 58.

As shown in FIG. 1, the valve body 52 has a hole coaxially formed with the passage 58 so as to face the compressed air supply passage 58, and after the steel ball 82 and the coil spring 84 are inserted into the hole. The blind plug 86 is driven. The first role of the coil spring 84 and the steel ball 82 is to urge the sliding valve body 62 toward the valve seat 56, and the end face provided with the notch 66 of the sliding valve body 62 is in close contact with the valve seat 56. It is to let you.
Another role of the coil spring 84 and the steel ball 82 is to align the sliding valve body 62 at the three rotational angle positions shown in FIG. For this reason, as shown in FIG. 2, the sliding valve body 62 has three grooves 88 having a semicircular cross section provided at equal angular intervals on the end surface opposite to the end surface provided with the notch 66. The sliding valve body 62 is positioned by snap fitting the steel ball 82 biased by the coil spring 84 into any one of the grooves 88. A semispherical recess may be provided in place of the groove 88 having a semicircular cross section.

In order to allow the sliding valve body 62 to rotate together with the operation ring 76 when the operation ring 76 is turned by hand, a concave groove is formed on the inner peripheral surface of the operating ring 76, and this concave groove and the sliding valve body are formed. A connecting pin 72 (FIGS. 1 and 2) is fitted between 62 concave grooves 70 (FIG. 3).
As shown in FIG. 2, male screw portions 90 and 92 are provided at both ends of the valve body 52 of the flow regulating device 50, and the handle 12 and the end ring as shown in FIG. 94 is screwed together.

Next, the operation of the flow regulating device 50 will be described with reference to FIGS. 4 and 5.
4 (a) and 5 (a) show that the sliding valve element 62 of the flow regulating valve 50 is positioned at the maximum flow rate position, and FIGS. 4 (b) and 5 (b) show the intermediate flow rate position. 4 (c) and FIG. 5 (c) show the position at the minimum flow rate position.
Since there is the connecting pin 72, when the operation ring 76 is turned by hand, the sliding valve body 62 also rotates. When the operation ring 76 is turned and the sliding valve body 62 is positioned at the maximum flow rate position shown in FIGS. 4A and 5A, the compressed air is shown in FIG. compressed air flowing into the valve chamber 54 from the inlet 74 flows out from the outlet opening 60 of valve seat 56 through a countersunk hole 66C of the valve chamber 54 and the maximum pocket depth D ₃ to the compressed air supply passage 58, the compressed air supply It is injected into the vibration chamber of the vibrator 16 through the passage 32 (FIG. 1), the compressed air filling chamber 34 and the compressed air inlet port 36. Since countersunk hole 66C has a maximum counterbore depth D ₃ from the exit opening 60 of the valve seat 56, flow resistance of the flow path indicated by the thick arrow in FIG. 4 (a) becomes a minimum, maximum output vibrator 16 Operate with.

When the operation ring 76 is turned and the sliding valve body 62 is positioned at the intermediate flow rate position shown in FIGS. 4B and 5B, the compressed air is shown in FIG. compressed air flowing into the valve chamber 54 from the inlet 74, the valve chamber 54, the maximum countersunk hole 66C of the depth D _3, and intermediate counterbore depth outlet opening of the valve seat 56 via the countersunk hole 66B of the D ₂ It flows out from 60 to the compressed air supply passage 58. Accordingly, since determined by 4 ventilation resistance of the flow path shown in (b) by a thick line arrow countersunk hole 66B countersunk depth D ₂ of governing the flow resistance, the ventilation resistance is an intermediate, the vibrator 16 Operates at an intermediate output.

When the sliding valve body 62 is positioned at the minimum flow rate position shown in FIGS. 4 (c) and 5 (c), as shown by the thick arrow in FIG. compressed air flowing into the valve chamber 54, through a maximum pocket depth _{D 3} of the counter bore 66C, countersunk hole 66B of the intermediate depth _{D 2,} and the smallest pocket depth _{D 1} countersunk hole 66A It flows out from the outlet opening 60 of the valve seat 56 to the compressed air supply passage 58. Since determined by 4 ventilation resistance of the flow path indicated by the bold arrow in (c) is countersunk depth D ₁ of the countersunk holes 66A governing it, airflow resistance is maximized, to operate the vibrator 16 with minimum output .
In this way, if the output of the vibrator 16 is changed into three stages of strong, medium and weak, the usability of the handpiece is good. Of course, the sliding valve body 62 can also be positioned at an arbitrary position between the three positions.

According to the present invention, the counterbore depths D ₁ , D ₂ , and D ₃ of the counterbore holes 66A, 66B, and 66C can be managed with high accuracy by NC control milling or the like. Thus, the output of the vibrator 16 can be set at the machining stage. Therefore, it is not necessary to adjust the flow rate when the handpiece 10 is assembled.

As shown in FIG. 6, the flow regulating device 50 of the present invention is incorporated into a dental handpiece in the form of an air turbine handpiece 96 having an air turbine 98, and the compressed air supply passage 100 to the air turbine 98 is installed. It is also possible to adjust the rotation speed of the air turbine 98 by adjusting the flow rate.
Further, although not shown, the flow regulating device 50 of the present invention can be incorporated into a root canal treatment handpiece having a compressed air drive vibrator.

Although specific embodiments of the present invention have been described above, the present invention is not limited to them, and various modifications and changes can be made. For example, as a drive source for a dental tool of a dental handpiece, all types of vibration generators and rotary drive devices driven by compressed air can be used.

10: Dental handpiece 12: Handpiece handle 14: Dental tool 16: Compressed air driven vibrator 18: Vibrator casing 20: Dental hose 30: Male joint compressed air supply port 32, 58: Compressed air supply Passage 34: Compressed air filling chamber 36: Compressed air inlet port 38: Vibrator output shaft 50: Flow regulating device 52: Valve body 54: Valve chamber 56: Valve seat 60: Outlet opening of valve seat 62: Sliding valve body 64: Blank 66: Notch of sliding valve body 66A, 66B, 66C: Counterbore 72: Connecting pin 74: Compressed air inlet 76: Operation ring 82: Steel ball 84: Coil spring 88: Positioning groove 96: Air Turbine handpiece


Patent applicant Micron Co., Ltd. Attorney Hiroshi Ito

Claims (11)

In a dental handpiece provided with a dental tool drive unit driven by compressed air, a flow control device for controlling the flow rate of compressed air supplied to the drive unit to control the output of the drive unit. :
A valve body having a valve seat formed across a compressed air supply passage for supplying compressed air to the drive unit, wherein an outlet opening to the compressed air supply passage downstream of the valve seat is formed in the valve seat When;
A sliding valve body that is slidably in close contact with the valve seat and variably controls the flow rate of compressed air supplied from the outlet opening to the driving unit;
A manual operation member for displacing the sliding valve body over a predetermined stroke;
The sliding valve body has a notch facing the outlet opening and extending not less than a length equal to the stroke parallel to the direction of the displacement, and measured from the surface of the valve seat. The notch depth D changes from one end to the other in the length direction of the notch, and the notch is a compressed air supply passage upstream of the valve seat at the end where the depth D is maximum. A compressed air flow control device for a dental handpiece, wherein the device is in communication with the device. A flow control device for a dental handpiece according to claim 1,
The flow valve device for a dental handpiece, wherein the notch of the sliding valve body is formed so that the counterbore depth D changes stepwise by machining. A flow control device for a dental handpiece according to claim 2,
The flow control device for a dental handpiece, wherein the machining is milling. The flow control device for a dental handpiece according to claim 2 or 3, wherein the notches of the sliding valve body are formed so that the counterbore depth D is different in three stages, and the handpiece is driven. The output of the part can be changed into three levels of strong, medium and weak. A flow control device for a dental handpiece according to any of claims 1 to 4, wherein the valve body has a substantially cylindrical shape with an axial cavity coaxial with the handpiece. Is formed with a valve chamber having a first fan-shaped axial cross section, the valve chamber being part of the compressed air supply passage, and the sliding valve body Has a second circumferential divergence angle smaller than the first circumferential divergence angle and a truncated fan-shaped axial section, and is fitted in the valve chamber so as to be slidable in the circumferential direction, The notch is formed in an arc shape so as to face the outlet opening while the sliding valve body slides in the circumferential direction, and the manual operation member is airtight and rotatable around the valve body. A flow control device for a dental handpiece comprising a manually operated ring. The flow control device for a dental handpiece according to any one of claims 1 to 5, wherein the sliding valve body is pressed against the valve seat by a spring. Valve regulating device. The flow control device for a dental handpiece according to any one of claims 1 to 6, wherein the sliding valve body is pressed against the valve seat by a spring-biased steel ball, In addition, it also functions as an alignment lock ball by snap-engaging with any of a plurality of spaced alignment recesses formed on the surface of the sliding valve body opposite to the valve seat. Flow control device for dental handpiece. It is a flow control apparatus of the dental handpiece based on Claim 5, Comprising: The said sliding valve body is machined by taking three disk-shaped blanks in the circumferential direction, and is made into three at equal angular intervals. A flow control device for a dental handpiece, characterized by being formed by cutting. The flow control device for a dental handpiece according to any one of claims 1 to 8, wherein the dental handpiece is a compressed air driven vibration scaler. The flow control device for a dental handpiece according to any one of claims 1 to 8, wherein the dental handpiece is a compressed air driven vibration type root canal treatment device. 9. The flow control device for a dental handpiece according to claim 1, wherein the dental handpiece is a compressed air driven turbine handpiece.

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