JP3491170B2 - Small fluid driven turbine handpiece - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small fluid-driven turbine type handpiece which is useful for machining work, medical treatment and the like. More specifically, the present invention aims to reduce the size of the handpiece itself and to improve the rotational speed of the turbine blade in the head chamber by supplying a small amount of energy, that is, having the blade at the peripheral portion and at the axial center portion. The present invention relates to a miniaturized, high-performance small fluid-driven turbine handpiece that increases torque (improves output) of a turbine rotor shaft (shaft) that holds various tools in a fixed manner.

[0002]

2. Description of the Related Art Conventionally, small fluid-driven turbine handpieces have been used, for example, for cutting materials, or for medical purposes. In orthopedic surgery (brain surgery, orthopedics, oral surgery, otolaryngology): It is widely used in the oral cavity treatment in dentistry such as excavation, opening, cutting and cutting of bones and teeth.

Among the small fluid-driven turbine handpieces described above, a small-sized dental fluid-driven turbine handpiece that uses pressurized air as a pressurized fluid that is a driving medium of a turbine is called a dental air turbine handpiece. The external shape is as shown in FIG. 1 cited in the description of the technical configuration of the present invention described later.
That is, as shown in FIG. 1, the dental air turbine handpiece (A) comprises a head portion (H) and a grip portion (G). The neck portion (N) of the grip portion (G) is connected to the head portion (H) and has a mechanism for supplying and discharging pressurized air to the air turbine arranged in the head portion (H). It has one inside. In FIG. 1, (B) shows a tool fixedly held on a rotor shaft of an air turbine. For convenience of description, the conventional art and the present invention will be described by taking the dental air turbine handpiece using pressurized air as a drive medium of the turbine as a typical example of a small fluid-driven turbine handpiece.

Needless to say, in the small fluid-driven turbine handpiece of the present invention, the drive medium for the turbine is not limited to the pressurized air. For example, the pressurized fluid as the drive medium of the turbine is not limited to pressurized air, and various types of pressurized fluid, pressurized gas including pressurized steam, etc. may be used. Therefore, in the following description, the terms air supply, air supply passage, air supply opening and exhaust, exhaust passage, exhaust opening used in relation to pressurized air are used in the case of applying other pressurized fluid. Supply path, supply port and discharge
Needless to say, it must be read as the discharge route and discharge port. Further, the application field of the small fluid-driven turbine handpiece of the present invention is not limited to the above-mentioned dentistry, but is widely applied to fields such as cutting of materials and medical applications. Furthermore, it goes without saying that in these application fields, the handpiece may be used not only in the form of being gripped and used by a hand but also as a component (member, part) of a device. And the handpiece of the present invention should be construed in the above meaning.

The internal structure of a conventional dental air turbine handpiece (A '), particularly the head portion (H') and the neck portion (N ') connected to the head portion (H'), is as follows.
It is shown in FIGS. That is, in FIGS. 22 to 23 for explaining the internal structure of a conventional dental air turbine handpiece (A ′), FIG. 22 is a vertical cross-sectional view as seen in the axial direction of the turbine rotor shaft (3 ′), and FIG. 22 C
It is a -C line sectional view.

As shown in FIG. 22, the head portion (H ') has a turbine rotor shaft (3') having a turbine blade (2 ') at its peripheral portion in a chamber (11') of the head (1 '). ), The turbine blade (2 ') is arranged, and the turbine rotor shaft (3') is rotatably supported inside the head (1 ') via a bearing portion (4'). The head (1 ') comprises a head body (12') and a cap portion (13 '). And
A chamber (11 ') for arranging the turbine blade (2') is formed inside the head body (12 '), and the turbine rotor shaft (3') is rotatably supported. A bearing portion (4 ') is provided. Needless to say, a tool shaft (5 ') such as a dental cutting tool is fixedly held at the shaft center portion of the turbine rotor shaft (3'), and various therapeutic actions are performed. In addition, a chuck (5) for gripping the tool shaft (5 ') is provided on the peripheral side of the tool shaft (5') as shown in the drawing.
1 ') is provided. Although the illustrated one is of a friction type chuck mechanism, a known one-touch chuck mechanism may be used.

As shown in FIG. 22, the bearing portion (4 ')
Is the inner ring (inner race) (41 '), the outer ring (outer race)
(42 '), ball (43'), and retainer (44 ')
) Consists of a ball bearing. In addition,
On the outer circumference and side of the bearing portion (4 '), an O-
A known mechanism for increasing the ring or shaft rigidity may be provided. Although the one shown in the drawing is a ball bearing mechanism using balls (43 '), it may be a known air bearing mechanism called an air bearing.

In FIG. 22 showing the structure of a conventional dental air turbine handpiece, a point to be particularly noted will be described later in detail in relation to a supply / exhaust system for pressurized air, but inside the chamber (11 '). Turbine blade (2 '
) Is an arrangement method. That is, in the conventional technique, as shown in FIG.
As shown in FIG. 2, the turbine blade (2 ′) is a turbine blade (2 ′) and the upper and lower inner wall surfaces (11) of the chamber (11 ′) when viewed in the axial direction of the turbine rotor shaft (3 ′).
Paying attention to the interval (d ₁ ') between 1', 112 '),
The point is that they are arranged with a large interval (d ₁ ). In the figure, the distance (d) between the peripheral side wall portion (113 ′) of the chamber (11 ′) and the turbine blade (2 ′)
₂ ') is generally narrower than the spacing (d'). Wherein the conventional products distance (d ₁ ') is a turbine rotor shaft (3' as viewed in the axial direction of), for example a turbine blade (2 ') in what height is 2.8 mm, the distance (d _1') Is known to have an interval of 1.150 mm (1150 μm). The interval (d ₁ ') is extremely large as compared with that of the present invention, the reason for which will be described later.

The air supply / exhaust system for the turbine blade (2 ') arranged as described above is
As shown in FIG. 22, it is arranged on the neck portion (N '). That is, in the air supply system (7 ') and the exhaust system (8') arranged inside the neck body (6 ') of the neck portion (N'), the air supply system (7 ') is connected to the chamber (11). ') One air supply passage (71') for supplying compressed air to a turbine blade (2 ') arranged inside the air supply passage, and one air supply arranged at the end of the air supply passage. The exhaust system (8 ') and a single exhaust passage (81') for exhausting the pressurized air in the chamber (11 '). One exhaust port (8a ') arranged at the end of the exhaust path,
It is composed of. In addition, the above expression "to exhaust the pressurized air in the chamber (11 ')" is not correct. This is because when the pressurized air supplied into the chamber (11 ') from the air supply opening (7a') passes through the air supply opening (7a '),
This is because the pressure is rapidly expanded and depressurized, and the pressurized state during air supply is not maintained. However, in the following description, the above-mentioned expression is adopted in relation to the expression of pressurized air supplied from the air supply port. Similarly, the flow of air within the chamber is also described by the term pressurized air flow. In the conventional dental air turbine handpiece (A ′) described above,
Although not shown, the head body (1) of the head portion (H ′)
2 ') or the body (6') of the neck (N '),
An illumination system for illuminating the treatment site, a water supply channel for sprinkling the treatment site with water or physiological saline to remove cutting heat of bones and teeth, and for cleaning may be provided. is there.

FIG. 23 illustrates a manner of supplying / exhausting pressurized air by the supply / exhaust system (7 ', 8') employed in the conventional dental air turbine handpiece (A '). It is a thing. That is, in the conventional dental air turbine handpiece (A '), first, the pressurized air constitutes one of the air supply system (7') arranged in the main body (6 ') of the neck portion (N'). Is supplied to the air supply passage (71 ') of the turbine, and the compressed air is introduced into the chamber (11') through one air supply port (7a ') and is injected into the turbine blade (2'), and the turbine rotor shaft ( 3 ') generates a rotational driving force. Then, the pressurized air in the chamber (11 ') is exhausted from the exhaust port (8a') constituting the exhaust system (8 ') arranged at the disposition position shown in FIG.
1 ') and discharged outside the system.

In the pressurized air supply / exhaust system of the conventional dental air turbine handpiece (A ') described above, focusing on the pressurized air flow, the air flow (b) shown in FIG. 23 (solid line and The air supply / exhaust system (7 ′, 8 ′) is configured so as to realize the (indicated by the dotted line). That is, as shown in FIG. 23, in the conventional air supply / exhaust system, the compressed air is supplied to the air supply system (7 ') disposed in the body (6') of the neck portion (N '). A turbine blade (2 ') disposed in the chamber (11') is injected from the constituent air supply passage (71 ') through the air supply port (7a'), and the turbine inside the chamber (11 ') is injected. A U-turn is made while orbiting around the rotor shaft (3 '). Then, the U-turned pressurized air is used to form an exhaust port (8 ') constituting an exhaust system (8') disposed in the body (6 ') of the neck portion (N').
It is guided from a ') to the exhaust passage (81') and exhausted to the outside of the system. In FIG. 23, in the pressurized air flow (b) in the chamber (11 ′), the solid line indicates the chamber (11 ′).
) Peripheral turbine wall (113 ') and turbine blade (2')
22) shows an orbiting (U-turn) component through a space (d ₂ ') (see FIG. 22). Also, the dotted lines are the upper and lower inner wall surfaces (111 ', 112') of the chamber (11 ').
FIG. 22 shows a component that orbits (U-turn) through a distance (d ₁ ′) between the turbine blade (2 ′) and the turbine blade (2 ′) (see FIG. 22). In addition, the above-mentioned interval (d ₁ ') is d in the conventional product.
It was explained that ₁ '= 1.15 mm (1150 μm), which is extremely large. However, in the conventional product in which such a large interval (d ₁ ') is set, the circular route (U-turn route) indicated by the dotted line is inevitable. It is formed in a regular manner.
Further, as will be described below, in the conventional product, it is recognized that the interval (d ₁ ) is intentionally increased.

In the conventional air supply / exhaust system for compressed air of the dental air turbine handpiece (A '), as shown in FIG. 23, the compressed air is supplied to the chamber (1).
1 ') while rotating around the turbine rotor shaft (3') from the supply port (7a ') as shown by the arrow (b), U
The reason why it is turned to reach the discharge port (8a ′) is that the flow of the pressurized air continues to give momentum to the turbine blade (2 ′) even during the orbiting process and the turbine rotor shaft (3 ′)
) Is based on the idea that it is applied to the increase of the rotation torque. For this reason, in the conventional air supply / exhaust system for pressurized air of the dental air turbine handpiece, the exhaust port (8a ') is based on the above-mentioned concept (design concept). The pressurized air injected from the chamber 7a ')
1 ') is disposed at the portion shown in FIG. 23 so that the air is exhausted at the portion circulating in the inside. That is, FIGS.
As shown in, the exhaust port (8a ') is connected to the air supply port (7a).
They are arranged in a substantially symmetrical position with a predetermined distance (C) from a '). Further, from the efficiency of momentum transmission to the turbine blade (2 ') by the compressed air and the exhaust efficiency of the compressed air from the chamber, the air supply port (7a') can supply the compressed air as shown in FIG. The exhaust port (8a ') shares the central level of the air supply port (7a'), and is arranged so as to inject into the substantially central portion of the turbine blade (2 ') as viewed in the axial direction of the turbine rotor shaft (3'). In the position, it is arranged at a portion having the above-mentioned predetermined interval (C). Note that the exhaust port generally has a larger opening area than the air supply port in terms of exhaust efficiency.

In the dental air turbine handpiece (A ') based on the above-mentioned conventional design concept, in order to increase the torque (improve output) of the turbine rotor shaft (3'), theoretically, pressurized air is used. The air supply rate of the pressurized air at the air supply port (7a ′) is increased or the amount of the pressurized air supplied per unit time is increased. This is because the force that the turbine rotor shaft (3 ') receives from the supplied pressurized air is
This is because the turbine blade (2 ') is equal to the momentum per unit time obtained from the compressed air flow, that is, the product of the supply rate of the compressed air and the supply amount (inlet) amount per unit time. Furthermore,
As described above with reference to FIGS. 24 to 25, the air supply speed and the air supply (inlet) amount described above depend on the pressurized air pressure and the cross-sectional area of the air supply port. Raise or
Increasing the cross-sectional area of the air supply port is a conventional means. It should be noted that FIGS. 24 to 25 show isentropic flow of a compressible inviscid gas in a system in which pressurized air is supplied from a compressor and is injected into a chamber (in a heat insulating system and reversible without any friction). Dynamical flow), and an equation of energy obtained by integrating Euler's equation of motion for a one-dimensional steady flow of a compressible inviscid gas along a stream line, that is, Bernoulli's equation
And [equation of state of gas] and [equation of state] of the gas, and ・ equation of continuity of Euler for compressible one-dimensional steady flow (equation of continuity), By using, as a theoretical value, the flow velocity at the air supply port of the chamber (air supply speed for a predetermined pressurized air pressure) (see FIG. 24), and the mass flow rate (air supply amount for a predetermined pressurized air pressure) (see FIG. 25). And these are shown in the graph.

However, in reality, in the conventional dental air turbine system housed in a chamber of a predetermined capacity having a supply / exhaust port of a predetermined size, the air supply speed and the air supply (entrance) amount described above are used. If one tries to increase the, the following is observed. In addition, the following observation results show the conventional dental air turbine handpiece described with reference to FIGS. 22 to 23 as an air turbine system, for example, Jet Master (FAR-E2) manufactured by Morita Manufacturing Co., Ltd.
It was obtained when an experimental device made of a transparent synthetic resin was faithfully copied, and an experiment was performed using the device.

(1) When the pressurized air pressure is increased in order to increase the air supply speed: As can be seen from FIG. 24, even if the pressurized air pressure is increased to 1 kgf / cm ² or more, the air supply speed becomes sonic velocity. It cannot be increased more than the above and does not contribute to the increase of the torque of the turbine rotor shaft (3 ').

(2) When the pressurized air pressure is increased in an attempt to increase the supply air amount: The above-mentioned proportional law begins to break down,
The efficiency of transfer of supply air energy deteriorates. In other words, supply air is pressurized air is in proportion to the percentage increase the supply amount is changed to 3.0 kgf / cm ² pressurized pressure shown in FIG. 25 for example from 2.0 kgf / cm ² The torque (maximum speed) of the turbine rotor (3 ') cannot be increased in proportion to the increasing rate of the supply air amount. This is due to the following reasons. (i) The pressure in the chamber (11 ') may increase due to the increase in the supply amount, and as a result, the supply speed may decrease. (ii) The pressurized air supplied is the turbine blade (2 '
), It orbits in the chamber (11 ') in the same direction as the turbine rotor shaft (3'), but its orbital speed is extremely low compared to the rotational speed of the turbine rotor shaft (3 '). Inside it begins to act as a resistor and its amount increases.

(3) When the cross-sectional area of the air supply port is increased in order to increase the air supply amount: The pressurized air supplied in the same manner as in (2) above has a resistor inside the chamber (11 '). However, this tendency is stronger than the method (2) of increasing the pressurized air pressure to be supplied. this is,
This is because, when the cross-sectional area of the air supply port becomes large, the pressurized air injected from the air supply port diffuses rapidly into the chamber (11 '), the speed decreases, and the resistance action is strengthened. For this reason,
The pressurized air injected from the large air supply port faces the resistance effect, and the efficiency of transfer of the air supply energy to the turbine blade (2 ') is worse than that in the above (2).

As a conventional technique for increasing the cross-sectional area of the air supply port of (3), for example, US Pat.
No. 893,242 and No. 4,020,556 propose dental air turbine handpieces having two independent air supply passage systems. The U.S. Patent is a wernc for fixing a tool shaft to a turbine rotor shaft in a structure of a dental air turbine handpiece.
h) a mechanism, a fiber optic system ensuring efficient light transmission (especially a means for connecting fiber optic bundles inside the handle), and means for supplying pressurized air to the turbine,
To give new features to the
3 to 9 and those having two independent air supply passage systems (thus having two air supply ports), that is, the cross-sectional area of the air supply port is increased to supply pressurized air. It discloses that the amount of energy is increased. More specifically, the dental air turbine handpiece of the above-mentioned U.S. Pat. The structure is such that compressed air is injected from the air port to the adjacent turbine blades that are disposed in the turbine housing to impart a rotational force to the turbine, and then the air is exhausted from the exhaust port. . The exhaust port is arranged above and below the air supply port in view of the description of the specification of the US patent and FIGS. 3 and 9. Therefore,
The aspect of the arrangement of the air supply / exhaust ports is similar to that of the present invention described later, but the essential difference between the two will be described here.

The major difference between the structure of the dental air turbine handpiece disclosed in the above-mentioned US patent and that of the present invention described in detail below brings about a significant difference in the operation and effect of the invention. This point will be described in detail later with empirical data. Compared with the dental air turbine handpiece of the present invention, the one disclosed in the above-mentioned US patent is different in the following points. -The pressurized air supply / exhaust system is completely different. That is, although the present invention has a plurality of air supply passages, they are joined together with a desired encounter angle so as to reduce the diffusion component in the pressurized air flow at the air supply port. Therefore, the pressurized air is injected from the single air supply port to the turbine blade located tangentially. On the other hand, the U.S. Pat. -The configuration of the supply / exhaust system for pressurized air is completely different. Figure 3 of the patent, as seen from FIG. 9, those disclosed in U.S. patent, the spacing between the upper and lower inner wall surfaces of the turbine blades and the chamber disposed in the chamber described by the diagram 22 (d ₁ ' ), It belongs to the prior art in terms of this interval (d ₁ ').
That is, the one disclosed in the above-mentioned U.S. Pat. on the other hand,
The present invention is of the non-circulating type as will be described later, and the two are completely different in structure.

As is clear from the above, the dental air turbine handpiece of the above-mentioned US patent is constructed with a concept completely different from the design concept of the present invention described later. It should be noted that the dental air turbine handpiece disclosed in the above-mentioned U.S. Pat. For example, it can be said that an approach is adopted in which the cross-sectional area of the air supply port is increased in order to increase the air supply amount in order to increase the torque of the turbine rotor shaft. However, in the above-mentioned US patent, since the arrangement method (arrangement position) of the two air supply ports is devised, the disconnection of one air supply port as described in (3) above. The ratio of the supplied pressurized air diffused in the chamber (11 ′) becomes lower than that of the approach of simply increasing the area. Therefore, although the transfer efficiency of supply air energy is improved to some extent, the improvement effect is extremely low as shown by the empirical data described later.

On the other hand, in the conventional dental air turbine system, in order to eliminate the above-mentioned drawbacks, an attempt may be made to enlarge the discharge port with respect to the supply port to remove the resistance effect of the pressurized air. However, when the exhaust port is made larger than the air supply port, the air pressure in the chamber (11 ′) decreases, and the pressurized air injected from the air supply port is rapidly diffused into the chamber and exhausted. As a result, the amount of pressurized air that collides with the turbine blade (2 ′) decreases, so that the efficiency of transfer of supply air energy deteriorates, and the torque (output) of the turbine rotor (3 ′) sharply decreases. Regarding the limits of various improvement measures including the conventional techniques described with reference to FIG. 22 to FIG. 23 and the improvement measures proposed in the US patent, empirical data will be given when explaining the technical configuration of the present invention. Will be described later.

[0022]

SUMMARY OF THE INVENTION The present invention overcomes the limitations of the prior art (conventional design concept) found in small fluid-driven turbine handpieces for dentistry, etc., and has a high performance based on a completely new design concept. It is an attempt to provide a small fluid driven turbine handpiece. The present invention relates to a conventional turbine system of the same kind in a small fluid-driven turbine handpiece, for example, in a dental air turbine handpiece, especially when a supply / exhaust system for pressurized air is reconfigured based on a completely new concept. It has been completed based on the finding that it is possible to reduce the size of the turbine rotor shaft and the efficiency of transfer of supply air energy to the turbine rotor shaft, which is significantly improved, and thus a significantly improved torque up can be obtained.

[0023]

SUMMARY OF THE INVENTION In general terms, the present invention relates to the turbine blade (3) of a turbine rotor shaft (3) having a turbine blade (2) in a chamber (11) of a head (1). 2) is arranged and the turbine rotor shaft (3) is rotatably supported inside the head (1) via a bearing (4),
And a neck portion (N) connected to the head portion (H)
Of the chamber (1) inside the body (6).
1) Consists of a supply system (7) for supplying a pressurized fluid to the turbine blade (2) and a neck portion (N) having a discharge system (8) for discharging the pressurized fluid in the chamber (11). (A) in a small fluid-driven turbine handpiece (A) that is installed in the chamber (11) of the head (1) .
The turbine blade (2) to be operated is (i) -1 . Height viewed in the axial direction of the turbine rotor shaft (3)
However, the upper and lower inner wall surfaces (111, 11) of the chamber (11)
The height of the turbine blade (2) is close to the height between 2) and (i) -2 .
It is close to the inner diameter of the inner wall surface (113) of the bar (11).
Consists of diameter, (ii). The supply system (7), together with having one supply port (7a), which comprises means (7b) refinement of the pressurized fluid in the vicinity portion of the supply opening (7a) (Iii). The exhaust system (8) has an outlet (8a).
It consists of objects and the arrangement position relationship of (iv). The one of the supply port of the supply system (7) (7a) and said <br/> discharge system outlet (8) (8a), supplied It is injected from the mouth (7a) and Tabinbu Les
The pressurized fluid immediately after it collides with the chamber (2)
(11) Immediately from the discharge port (8a) without circulating inside
To discharge the seat, that the discharge port to neighbor sites of the supply port (7a) (8a) in which is disposed, to a compact fluid-driven turbine handpiece, wherein.

The technical constitution and embodiments of the present invention will be described in detail below with reference to the drawings while referring to the dental air turbine handpiece described above. Needless to say, the present invention is not limited to the illustrated one.

First, in order to help understanding of the present invention, the trigger of the present invention and the related art of the present invention previously proposed by the present inventors will be described. The present invention is triggered by the present inventors by faithfully copying the conventional dental air turbine handpiece described with reference to FIGS. 22 to 23, for example, the jet master (FAR-E2) manufactured by Morita Manufacturing Co., Ltd. The following findings were obtained by making an experimental device made of transparent synthetic resin which was used, and using this device, and experimenting with a small-sized Styrofoam resin ball in the chamber and pressurized air. . That is, the present inventors have obtained the following findings: (i) The pressurized air pressure to be supplied is 0.5 kgf / cm ² (10-2
In the case of up to about 5 1 (liter) / minute, it was observed that the pressurized air circulates in the chamber in the opposite direction to the turbine rotor about the turbine rotor axis after colliding with the turbine blade. This air flow serves as a resistance to the rotation of the turbine rotor. (ii) When the pressurized air pressure to be supplied exceeds 0.5 kgf / cm ² , the pressurized air begins to circulate in the chamber in the same direction as the turbine rotor along with a sudden change in the rotation noise and the exhaust noise. Moreover, the orbital speed thereof is extremely slower than the rotational speed of the turbine rotor. (iii) Further, in order to improve the rotational speed (torque) of the turbine rotor, the air pressure of the pressurized air to be supplied is increased or the supply amount is increased. Through such an experiment, for example, the air pressure of the pressurized air to be supplied is 2.5 kgf / cm ²
It was observed that when the pressure was higher than (45 l (liter) / min), the air pressure in the chamber increased and the supplied pressurized air behaves as if acting as a resistor in the chamber. For example, it contributes little or negative to torque up). (iv) When the exhaust port is enlarged to improve the phenomenon of (iii), the air pressure in the chamber decreases, but the pressurized air injected from the air supply port diffuses rapidly and is exhausted. On the contrary, torque reduction is observed.

Then, the inventors of the present invention described the above (iii) and (i
In order to reduce or eliminate the negative effect of v), the design concept of the conventional dental air turbine handpiece was retroactively examined. Regarding the conventional design concept,
As described in detail in the section “Prior Art”. as a result,
The inventors of the present invention have proposed a conventional system for supplying compressed air to a turbine blade and a system for exhausting pressurized air from inside a chamber, particularly in a system for exhausting air from inside a chamber in a conventional dental air turbine handpiece. The method of circulating pressurized air in the chamber of (circulation type) (hereinafter, also referred to as circulation type) and the arrangement method of the air supply port / exhaust port (air supply / exhaust system) based on the circulation type are as follows: In addition, there is a method that does not allow pressurized air to circulate as much as possible (hereinafter also referred to as a non-circulating type in order to distinguish it from the conventional type) and a method of arranging the air supply port and exhaust port based on the non-circulating type. It was found that, when it is revised, a markedly superior action effect, that is, a high efficiency of transfer of intake air energy (torque increase) is exhibited.
Needless to say, the above-mentioned non-circulating type is the core of the design concept applied to the dental air turbine handpiece of the present invention.

Further, in the conventional circulating type, since the pressurized air is circulated in the chamber, the space space between the chamber housing member and the turbine blade (see the spacing d ₁ 'in FIG. 22) is reduced. Although it is large, it was also found that the non-circulating type can eliminate the above-mentioned space space, and therefore the above-described excellent action and effect are exhibited in a downsized air turbine system.

The present inventors have previously proposed a small fluid-driven turbine handpiece which is completely different from the conventional approach, based on the above-mentioned findings and examination results (see Japanese Patent Application No. 6-36404). The small fluid drive turbine handpiece previously proposed by the inventors of the present invention has the following technical configuration, although there are some differences in terms defining the present invention. That is, the small fluid-driven turbine handpiece proposed by the inventors of the present invention is
The turbine blade (2) of the turbine rotor shaft (3) having the turbine blade (2) is arranged in the chamber (11) of the head (1), and the turbine rotor shaft (3) is arranged inside the head (1). ) Is a head portion (H) rotatably supported via a bearing portion (4), and a neck portion (N) connected to the head portion (H), inside the main body (6). The chamber (11)
And a neck portion (N) having a discharge passage (8) for discharging the pressurized fluid in the chamber (11) and a supply passage (7) for supplying the pressurized fluid to the turbine blade (2) therein. In the small fluid drive turbine handpiece (A),
(A) The supply path (7) has one supply port (71), and (b) one supply port (7) of the supply path (7).
The arrangement positional relationship between 1) and the discharge port (81) of the discharge path (8) is such that the discharge port (81) is arranged in the vicinity of the supply port (71). Is. In the supply / exhaust system (corresponding to the air supply / exhaust system in the case of a dental air turbine handpiece) in the above-mentioned proposal by the inventors, in order to further ensure the non-circulating type, It goes without saying that limiting requirements regarding the distance between the turbine blade (2) and the upper and lower inner wall surfaces of the chamber (11) may be added.

That is, the small fluid-driven turbine handpiece for dentistry, etc. previously proposed by the present inventors adopts a non-circulating type and a pressurized fluid supply / discharge system based on the non-circulating type. It is a thing. More specifically, the present inventors have previously proposed a method of arranging a pressurized fluid supply / discharge system that realizes a non-circulating type, in which the pressurized fluid is rotatably arranged in a chamber from a supply port. After injecting to the installed turbine blade and applying rotational force to the turbine rotor shaft, the pressurized fluid is not circulated in the chamber as in the conventional design concept, but is immediately discharged from the discharge port. Is based on a completely different design concept. The basis of the idea of immediately discharging the pressurized fluid from the chamber is that the pressurized fluid remaining in the chamber after being injected into the turbine blade acts as a resistor. Is as described above.

After that, the inventors of the present invention further studied in order to improve the performance of the above-mentioned non-circulating type system. Next, the present invention will be described by taking a dental air turbine handpiece as an example. As a result, in the air supply / exhaust system for the non-circulating type dental air turbine handpiece, in particular, as described above in the structure of the air supply system, the air supply system has one air supply port (7a) and the air supply port. In the case where it is configured by a device having a compressed air restricting means (7b) in the vicinity of (7a), superior action and effect can be exhibited as compared with a device having another non-circulating type air supply system. Was found. It goes without saying that the present invention has the above-mentioned technical constitution in a non-circulating type system.

The present invention having the above-mentioned technical structure is distinguished from the conventional orbiting type by the fact that it is a non-orbiting type, as compared with the conventional one. Compared with the non-circulating type (Japanese Patent Application No. 6-36404), the non-circulating type is the same, but the structure of the air supply / exhaust system, particularly the air supply system ((ii) of the present invention ). The configuration) is significantly different. The present invention and the one previously proposed by the present inventors (Japanese Patent Application No. 6-3
6404), the present invention provides a means for reducing the diffusion component of the compressed air when the compressed air is injected from the supply port. This is the content of the configuration of the air supply system (configuration (ii) of the present invention). It is needless to say that the above-mentioned important constituent elements of the present invention will be described later with reference to the drawings, and the empirical data supports the prominence of the action and effect based thereon.

Hereinafter, embodiments of the dental air turbine handpiece of the present invention will be described in more detail with reference to the drawings. Needless to say, the invention is not limited to what is shown.

1 to 5 illustrate a dental air turbine handpiece (A) according to a first embodiment of the present invention. FIG. 1 is a perspective view of the entire handpiece. Figure 2
Shows a partial longitudinal sectional view of the handpiece (A) as seen in the axial direction of the turbine rotor shaft. FIG. 3 is a horizontal sectional view taken along the line AA of FIG. It should be noted that, in FIG. 2, the narrowing-down means (7b) disposed in the vicinity of the air supply port (7a) of the air supply system (7).
It should be noted that is drawn in a perspective view to assist in understanding the structure.

FIGS. 4 to 5 are views for explaining the major feature point (technical constitutional requirement (i)) of the present invention in the dental air turbine handpiece of the present invention. FIG. 4 is a vertical cross-sectional view taken along the line A ₁ -A _{1 in} FIG. FIG. Figure 5
It is a figure for demonstrating the narrow-down means (7b) of this invention related to FIG. 4, and its specific structure.

As shown in the drawings, the dental air turbine handpiece (A) of the present invention is a head portion (H), a grip portion (G), and one end portion of the grip portion (G), which is the head portion. It is composed of a neck portion (N) connected to (H). In the following description, the members (parts) constituting the dental air turbine handpiece (A) of the present invention are the respective members (parts) of the conventional handpiece (A ').
22 to 23 are described by numerical symbols (1 ', 2', etc.) having a dash symbol ('), but in the present invention, they are described by numerical symbols without the dash symbol, and the same numbers are used. Reference numerals indicate corresponding members (parts).

First, in the dental air turbine handpiece of the present invention, referring to FIGS. 2 and 3, an air supply / exhaust system for realizing a non-circulating type pressurized air flow, which is the first characteristic point, will be described. And explain in detail. Next, the second feature of the present invention, the means for narrowing down the pressurized air applied to the vicinity of the air supply port in the air supply system will be described in detail with reference to FIGS. 4 to 5. 2 to 3
As shown in FIG. 2, the turbine blade (2) arranged in the chamber (11) of the head (1) is applied to the inside of the main body (6) of the neck portion (N) with respect to a substantially central portion in the axial direction. As an air supply system (7) for injecting compressed air, two air supply passages (71, 7) having one air supply port (7a) are provided.
2) is provided. In addition, two air supply passages (71, 72)
Are clearly shown in FIG. In the present invention, the axial direction of the turbine blade (2) is a direction coinciding with the axial direction of the turbine rotor shaft (3). Further, the position of the air supply port (7a) is arranged so that the pressurized air to be injected transmits maximum energy to each turbine blade (2) rotating in the chamber (11). Needless to say. On the other hand, the neck (N)
Immediately after the compressed air collides with the turbine blade (2) inside the body (6) of the
1) Exhaust system for immediate exhaust from inside (8)
As shown in FIGS. 2 to 3, a total of two exhaust ports (81) are provided directly above and directly below the one air supply port (7a).
a, 82a) are provided.

According to the present invention, in order to immediately discharge the pressurized air from the inside of the chamber (11) immediately after the above-mentioned compressed air collides with the turbine blade (2), the exhaust port is provided with an air supply port. It must be located near the mouth.
The above-described arrangement of the air supply / exhaust system is the first embodiment of the present invention, but the present invention is not limited to this. For example, in the air supply system (7), two or more air supply passages (71, 72, ... 7n, n is an integer of 2 or more) as an air supply passage having one air supply opening (7a). May be provided, or may be provided with one air supply passage (71). Further, in the exhaust system (8), two or more exhaust paths (81, 82,
················································································································· For each of the above two exhaust gas Besides having the ports (81a, 82a), it may have three or four exhaust ports. As described above, when the exhaust ports (81a, 82a) are arranged in the vicinity of the air supply port (7a), as shown in FIG. 3, regardless of the rotational speed of the turbine rotor shaft (3), Immediately after the compressed air hits the turbine blades (2), the pressurized air flow (a) indicated by the solid arrow is realized. That is, a non-peripheral type pressurized air flow (a) is realized by the air supply / exhaust system. This pressurized air flow (a) is a completely different air flow from the conventional circulating type pressurized air flow (b) shown in FIG.

Next, the second feature of the present invention, which is the second feature of the air supply system (7), will be described with reference to the compressed air restricting means (7b) applied to the vicinity of the air supply port (7a) of FIG. This will be described in detail with reference to FIG. The second characteristic point of the present invention is born from the following idea. That is, according to the present invention, in order to realize the non-circulating type air flow (a) in the pressurized air, which is the first characteristic point, the supply and
It is premised on configuring an exhaust system.
More specifically, as described above, air supply in the present invention
The exhaust system is arranged in the main body (6) of the neck portion (N) such that the compressed air is immediately discharged from the chamber (11) immediately after the compressed air collides with the turbine blade (2). It is what is done. The pressurized air is immediately discharged from the chamber (11) in order to remove the influence of the pressurized air acting as a resistor in the chamber (11) as much as possible. Therefore, the inventors of the present invention, in other words, when the pressurized air is injected from the air supply port (7a), if an air flow with a small diffusion component is injected, in other words, it has excellent straightness. If the compressed air is injected, not only the transfer efficiency of the supply air energy to the turbid blade (2) but also the exhaust efficiency from the inside of the chamber (11) after the collision with the turbine blade (2) is improved. It is considered that the pressurized air that stays in the chamber (11) is also entrained and exhausted to the outside of the system, so that the overall torque can be increased (the output can be improved). What was born based on this way of thinking was means (7b) for narrowing down the compressed air.
Is.

FIG. 4 shows a means (7b) for narrowing down compressed air (7b) (which is applied to the above-described air supply / exhaust system (first characteristic point) in the dental air turbine handpiece according to the first embodiment of the present invention. The second feature point) is shown. The configuration of the narrowing-down means (7b) shown in FIG. 4 will be specifically described with reference to FIG. Narrowing means (7) of the present invention
b), two air supply passages (7) having a desired meeting angle (θ).
1, 72) are merged in the vicinity of the air supply port (7a). In the present invention, the meeting angle (θ) is defined by the intake port (7) as shown in FIG.
Turbine blade (2) at a position where compressed air collides with the center point (7c) of a) and the air supply port (7a) in a cutting line direction.
The intersection angle at which the center lines (l ₂ , l ₃ ) of the air supply passages (71, 72) intersect the imaginary line (l ₁ ) connecting the center points (21) of. In the present invention, the position of the intersection of the virtual line (I ₁ ) and the center line (I ₂ , I ₃ ) of the air supply passage is
The center point (2) of the turbine blade (2) shown in FIG.
It has been confirmed that the excellent effect can be realized even if it is 1) or between the center point (21) and the center point (7c) of the air supply port (7a). Therefore, it should be understood that the encounter angle (θ) of the present invention is defined in the manner described above. In the present invention, the encounter angle (θ) may be appropriately determined under the condition that the diffusion component is reduced. As can be seen from the examples described below, the meeting angle (θ) is preferably 5 to 40 °. In addition, in FIG. 5, (7b) also shows a portion to which the narrowing-down means (7b) is applied.

In the present invention, the means (7b) for restricting the pressurized air is not limited to the one shown in FIG. 5, but various modifications are possible. Needless to say,
The modification of the narrowing means (7b) has the same meaning as the modification of the air supply system. 6 to 8 show modified examples of the means (7b) for restricting the pressurized air. 6 is a modification of FIG. 5, and has a straight advance portion (7c) in the vicinity of the air supply port (7a) as shown. 7 differs from the method of forming the narrowing-down means (7b) by joining the two air supply passages of FIGS. 5 to 6 with each other, the air supply port (71) of the single air supply passage (71) is different. 7a) has a conical shape (cone shape) so that a portion in the vicinity of 7a) has a desired contact angle (θ) to constitute a compressed air restricting means (7b). In the embodiment of FIG. 7, the encounter angle (θ) means the extension lines (l ₂ , l ₃ ) of the ridgeline of the conical part (cone part) and the imaginary line (l ₁ ) described above.
It means the angle of intersection with. The one in FIG. 8 is
It is a modification of FIG. 7, and as shown in the drawing, the air supply port (7a).
It has a straight-ahead portion (7c) in the vicinity of. Further, as shown in FIG. 5, two air supply passages (71, 72) are provided.
Instead of merging the gas in the vicinity of the air supply port (7a) to form the narrowing means (7b), even if only one air supply passage is provided, the partition wall portion (7e) is formed in the triangular triangular central portion (7d) of FIG. ) May be provided to configure the narrowing-down means (7b). Furthermore, in the present invention, the narrowing-down means (7b) is the same as shown in FIGS.
1), that is, the axial direction of the turbine blade (2) (corresponding to the axial direction of the turbine rotor shaft) may be emphasized, or in contrast to the embodiments of FIGS. 4 to 5. May be arranged in a vertical direction. In the latter case, the narrowing means (7b) should be displayed in the air supply passages (71, 72) of FIG.

FIG. 9 shows the pressurization injected from the air supply port (7a ') in the air supply system applied to the conventional dental air turbine handpiece described with reference to FIGS. It is a figure explaining the diffusion component of an air flow. As shown in the figure, the conventional type has an air supply path (nozzle).
Since (7 ') is composed of one straight nozzle (71'), in other words, since a means for restricting the pressurized air is not used in the vicinity of the air supply port (7a '), A diffusive component is generated in the pressurized air injected from the air port (7a '). Needless to say, in the prior art, unlike the non-circulating type of the present invention, since it is the orbiting type, the diffusion portion acts as a resistor in the chamber and contributes to the improvement of torque increase. Far from doing it is negative.

That is, in the dental air turbine handpiece (A) of the present invention, in order to realize the pressurized air flow (a), in the above-mentioned aspect, (i) the air supply system (7). Has one air supply port (7a) and a compressed air restricting means (7b) in the vicinity of the air supply port (7a), and (ii) the air supply system (7) The arrangement positional relationship between one air supply port (7a) and the exhaust port (81a, 82a) of the exhaust system (8) is determined by the air supply port (7).
The requirement that the discharge ports (81a, 82a) are provided in the vicinity of a) is essential. The requirements of (i) above are, for example, downsizing of equipment, economic efficiency (cost merit in equipment manufacturing), durability (problem of strength of neck part) as compared with those having two air supply ports. Needless to say, it is required from).

In the present invention, in order to further accelerate the realization of the pressurized air flow (a), FIG.
It is also important to reduce the distance (d ₁ ′) between the turbine blades disposed in the chamber described above and the upper and lower wall surfaces of the chamber, and in the embodiment of the present invention, the distance (d ₁ ) in FIG. . That is, in order to immediately evacuate the inside of the chamber (11) without causing the pressurized air to impinge on the turbine blade (2) and circulate in the chamber (11), the space volume of the chamber (11) and It is preferable that the turbine blades (2) arranged in the chamber (11) have substantially the same size. As described above, the space volume of the chamber (11) and the size of the turbine blade (2) depend on the turbine blade (2).
Of substantially the same size that ensures the rotation of the compressed air in the chamber (11) forms a non-circulating flow (a in FIG. 3) rather than a circulating flow (b in FIG. 23). The probability is increased and it will be immediately exhausted from the exhaust port.

The fact that the space volume of the chamber (11) and the size of the turbine blade (2) are substantially the same means that the space (d ₁ ), that is, the chamber (11) shown in FIG. That is, the interval (d ₁ ) between the upper and lower inner wall surfaces (111, 112) and the turbine blade (2) arranged in the chamber (11) is set small. The interval (d ₁ ) should be set so that the pressurized air in the chamber (11) forms a non-circulating flow without forming a circular flow as described above, or the formation probability thereof becomes high. I have to. The interval (d ₁ ) is
It may be set according to various criteria. For example, the turbine blade (2) viewed in the axial direction of the turbine rotor shaft (3)
Based on the height (h) of (see FIG. 10 described later),
The distance (d ₁ ) may be set to be 1/10 or less of the height (h). Incidentally, among the conventional products, it is known that the height (h) is 2.8 mm.

Further, as viewed in the direction perpendicular to the axial direction of the turbine rotor shaft (3), the distance (d ₂ ) between the turbine blade (2) and the inner peripheral wall surface (113) of the chamber (11).
The distance (d ₁ ) may be set to be 2.5 times or less of the distance (d ₂ ) based on (see FIG. 2). Note that in the conventional product, as the interval corresponding to the distance _{(d 2) (d 2 '} ) ( see FIG. 22), 100
It is known that the size is up to 200 μm. For example, a dental air turbine handpiece (jet master: FAR-E2) manufactured by Morita Manufacturing Co., Ltd. has an interval (d ₂ '
) Is 100 μm. Further, if the size of the space (d ₁ ) is explained as an absolute value, not as a comparison value with respect to the height (h) or space (d ₂ ), the space between the conventional air turbine handpieces for dental use ( d ₁ ')
(Refer to FIG. 22) is extremely large at 1150 μm, while the probability of non-circulating flow formation is higher than 500 μm,
It is preferably set to a value of 200 to 100 μm. The distance (d ₁ ) value is preferably as small as possible, but the accuracy requirement of the member (part) becomes high, so that the sufficient effect is exhibited at 500 μm or less. In the present invention, as shown in the experimental data described later, the requirement for the interval (d ₁ ') is based on the interval (d'
) Is 1150 μm, and further 1150 μm to 60
It is peculiar that even if the size is reduced to 0 μm, there is no effect, and the excellent effect is exhibited in the region of 500 μm or less.

In the dental air turbine handpiece (A) of the present invention, the size of the one air supply port (7a) is related to the size of the exhaust port, but may be appropriately determined. Generally speaking, when the size of the air supply port (7a) is small, there is a high probability that even a slight diffusion component near the air supply port will collide with the turbine blade (2).
When the size of a) becomes large, the probability is small. Therefore, in the case of the large air supply port (7a), the effect of the narrowing means (7b) is likely to be exhibited in the case of the narrowing means (7a). In the present invention, the air supply port (7
The size of a) is based on the size (height or diameter) of the air supply port as viewed in the axial direction of the turbine blade (axial direction of the turbine rotor shaft).

In the dental air turbine handpiece (A) of the present invention, the size of the exhaust ports (81a, 82a) arranged in the vicinity of the air supply port (7a) depends on the exhaust efficiency. It is preferable that the size is larger than the size of the air supply port (7a). The size of the exhaust ports (81a, 82a) is related to the size of the air supply port (7a), but as shown in experimental data described later, for example, the height (h) of the turbine blade (2) (h = 2.8 mm), one size of the exhaust port (81a, 82a) is 1.0 mm (absolute value). In the present invention, the exhaust port (81
The size (a, 82a) of the exhaust gas is the size (height or diameter) of the exhaust port as viewed in the axial direction of the turbine blade (axial direction of the turbine rotor shaft).

In the dental air turbine handpiece (A) of the present invention, the air supply port (7a) and the exhaust port (8).
The cross-sectional shape of 1a, 82a) is not particularly limited. For example, it goes without saying that the shape may be circular or rectangular in cross section. Further, an air supply passage (71) communicating with one air supply opening (7a) and an exhaust passage (81, 8) communicating with the exhaust openings (81a, 82a).
2) may be appropriately arranged in consideration of the shape of the turbine blade (2) (including the number of turbine blades) and the strength of the neck body (6). For example, although there are differences in the arrangement method of the air supply passage / exhaust passage of FIG. 3 and FIG. 21 described later, the arrangement method is not limited to these and may be appropriately provided.

In the dental air turbine handpiece (A) of the present invention, the compressed air is immediately exhausted from the chamber (11) of the head (1) as soon as possible after colliding the compressed air with the turbine blade. In order to do so, it is important to configure the pressurized air supply / exhaust system based on a completely different design concept from the conventional one. It is also preferable to use. Figure 10 (a)
13 (a) to 13 (a) and (b) show various blade shapes. Reference numeral 21 in the drawing denotes a blade support body that fixes the turbine blade (2). Further, in each figure, (a) is a perspective view of a main part, and (b) is a top plan view of the turbine blade (2). 10 to 12, the surface on which the pressurized air collides is one or two arc surfaces, and the exhaust gas is guided to the exhaust port along the arc surfaces. Needless to say, the present invention is not limited to a blade having such an arc surface, and may have a flat surface shown in FIG.

In the dental air turbine handpiece (A) of the present invention, the pressurized air supply / exhaust system is not limited to the one described above. That is, as shown in FIGS. 2 to 3, pressurized air is applied from the air supply port (7a) to the substantially central portion of the turbine blade (2), and the turbine blade (2) is immediately U-turned in the vertical direction. , U
The invention is not limited to a mode in which the turned air flow is exhausted from two exhaust ports (81a, 82a) separately arranged directly above and below the air supply port (7a). For example, it goes without saying that the pressurized air may be biased to the upper or lower portion of the turbine blade so as to collide with it, and the exhaust air may be discharged from one of the opposite sides.
In addition, as an aspect in which the exhaust port is arranged in the vicinity of the air supply port, it is directly above and / or when viewed in the axial direction of the turbine rotor shaft (3).
It goes without saying that it may be provided directly below (a site adjacent to the air supply port in the vertical direction) or may be provided in a site adjacent to the horizontal direction, and further, these may be combined.

Next, an experimental example for comparing the superiority of the method of the present invention and the conventional method will be shown. First, an experimental apparatus that faithfully reflects the method of the present invention and the conventional method, which is manufactured so that various kinds of experimental data can be obtained and directly compared, will be described. The experimental apparatus of the method of the present invention faithfully reflects the structure described in FIGS. 2 to 3, and is shown in FIGS. 14 to 16. The conventional experimental apparatus faithfully reflects the structure described in FIGS. 22 to 23 and is shown in FIGS. 17 to 19.

(1) Experimental apparatus of the present invention method (1)-(i) Outline of experimental apparatus of the present invention method An outline of the experimental apparatus of the present invention method is shown in FIGS. 14 to 16. In the figure, the air supply port (71) has an air supply port (7
Although the narrowing means (7b) is not clearly shown in the vicinity of a), this should be understood as a simplification of the drawing. In FIG. 14, H indicates a head part, and its housing member is made of a transparent synthetic resin plate (acrylic resin) H ₁ , H.
₂ and H ₃ . Then, an air supply path (71) and an exhaust path (81, 82) for the pressurized air were formed in H ₁ (the synthetic resin plate in the center) as shown in the figure. Further, it goes without saying that the bearing portion is housed in the internal space portion indicated by the dotted lines of the housing members H ₂ and H ₃ . In addition,
The reason why the housing member is made of synthetic resin is that it is suitable for setting various experimental conditions (for example, the size and shape of the air supply / exhaust port).

FIG. 15A is a plan view of H ₁ .
FIG. 15B is a cross-sectional view taken along the line D-D of FIG. 15A, showing an arrangement mode of the air supply passage (71) and the exhaust passages (81, 82). 16 is a sectional view taken along the axial direction of the air supply passage (71) after the turbine blades are arranged in the chamber (11) in FIG. 15, that is, a sectional view taken along line EE of FIG. 15 (a). . Other housing members (H ₂ , H ₃ )
Is also drawn to clarify the flow direction of the pressurized air flow. Further, in the housing member (H ₁ ), 10 a in the drawing in which hatching is omitted to show other important constituent elements indicates that the turbine blade has the shape shown in FIG. 10 (a). . Further, d represents the distance between the turbine blade and the upper and lower housing members (H ₂ and H ₃ ). As can be seen from the above, in the small fluid-driven turbine handpiece of the present invention, the head (1) of the head portion (H) and the main body (6) of the neck portion (N).
Needless to say, may be made of synthetic resin. At that time, needless to say, it is preferable to select a synthetic resin having durability against heat and vibration generated by the turbine system rotating at high speed. In the present invention, by using synthetic resin for the above parts, a small fluid-driven turbine handpiece is provided which is excellent in economy and weight, as well as in terms of easiness of manufacturing as compared with the conventional fluid-driven turbine handpiece made of metal. It

(1)-(ii) Experimental conditions of the experimental apparatus of the present invention The experimental conditions of the experimental apparatus of the present invention described above are as follows. <Experimental conditions> ・ Pressurized air pressure to be supplied (pressurized air pressure): 1.0 kgf / cm ²・ Inner diameter of head chamber (11): φ9.1 mm ・ Size and number of turbine blades (Fig. 10 (a),
10 (b)): In FIG. 10 (a), w ₁ = 1.
3 mm, in FIG. 10 (b) h = 2.8 mm, w ₂ = 0.
8 mm, w ₃ = 0.13 mm The number of blades arranged on the turbine blade support (21) is eight. The distance between the housing members (H ₂ , H ₃ ) and the turbine blade (d ₁ ) / the thickness of the housing member (H ₁ ): d ₁ : basically 150 μm, but for comparison with the conventional method, 1150 Values of ~ 600 μm were also used. Thickness of H ₁ : 5.1 mm (Note) Since the thickness of H ₁ is 5.1 mm and the height (h) of the turbine blade is 2.8 mm, the turbine blade is placed at the center of the thickness of H _1. When installed, 1150μm (1150μm x 2 = 2.3mm) above and below the turbine blade
A space space of width is formed. -Arrangement position and size of air supply / exhaust port: Arrangement position of air supply / exhaust port: See Fig. 15 (b). Diameter of air supply port (7a) of air supply path (71): φ1.70 mm
(See Table 1). Encounter angle (θ of the narrowing means applied to the air supply passage (71)
°): See Table 1. Size (e ₁ × e ₂ ) of the exhaust ports (81a, 82a) of the exhaust passages (81, 82): 4.55 × 1 mm (two) (FIG. 15)
(See (b))

(2) Conventional Experimental Device (2)-(i) Outline of Conventional Experimental Device An outline of the conventional experimental device is shown in FIGS. Since FIGS. 17 to 19 correspond to FIGS. 14 to 16 showing the experimental apparatus of the method of the present invention, the differences between the two can be easily understood. Especially, the big difference is that the air supply passage (mouth) (71 ', 7a') and the exhaust passage (mouth) (81 ', 8).
a '), the air supply passage (71') is a straight nozzle (θ = 0 °), and in order to circulate the pressurized air in the chamber (11 ') as shown in FIG. the housing member _{(H 2 ', H 3'} ) to the distance of the turbine blades (10a) (d ₁ ') is that large. In the housing member (H ₁ ′) of FIG. 19, hatching is omitted to show other important constituent elements.

(2)-(ii) Experimental Conditions of Conventional Experimental Apparatus Experimental conditions of the conventional experimental apparatus described above are as follows. <Experimental conditions> Compared with <Experimental conditions> of the method of the present invention, only the following points are different, and the other points are exactly the same.・ Space between housing materials (H ₂ 'and H ₃ ') and turbine blades (d ₁ '): d ₁ ': basically 1150 μm, but a value of 150 μm is also adopted for comparison with the method of the present invention. did. (Note) The value of d'1150 μm is the value of the conventional product. Also, the housing member H ₁ '
Has the same thickness as the method of the present invention. -Arrangement position and size of air supply / exhaust port: Arrangement position of air supply / exhaust port: See Fig. 18 (b). Diameter of air supply port (7a ') of air supply path (71'): φ1.7
0 mm (see Table 1). Size of exhaust port (8a ') of exhaust path (81'): φ3.
0 mm (see FIG. 18 (b)).

(3) USP type experimental device Further, USPatent No. 3,89 described as the prior art
No. 3,242 and No. 4,020,556 are incorporated in the housing members (H _{1 to} H ₃ ) used when the experimental apparatus of the present invention is manufactured, and the experimental apparatus (hereinafter, referred to as A USP type experimental device) was manufactured.
Regarding the USP type experimental device, the experimental device was manufactured in consideration of the technical contents disclosed in the US Patent, particularly Fig. 2 to Fig. 3 and Fig. 9 thereof, in consideration of the following points. In consideration of the fact that the size (diameter) of the two air inlets is approximately the same as the height of the turbine blades, in the experimental apparatus of the present invention method, the blade of the total amount of the diameters of the two air inlets The two air supply ports (φ1.2 × 2) are arranged so that the ratio to the height (h) (h = 2.8 mm) becomes large. The exhaust port was the same as that of the experimental apparatus of the present invention (see Table 1). The distance between the upper and lower inner wall surfaces of the chamber and the turbine blade is the same as the design concept of the prior art (d ₁ ') = 1150.
˜600 μm.

The maximum rotational speed (X) and the air supply amount (Y) per unit time were measured under a predetermined pressurized air pressure (1.0 kgf / cm ² ) using the various experimental devices described above. . The experiment was performed at room temperature of 25 ° C. The supply air pressure was measured by a digital pressure sensor and displayed in units of kgf / cm ² . The maximum number of revolutions is measured by measuring the signal from the high-speed response type photoelectric switch with a counter (counter) and
Displayed at ⁴ rpm. The air supply amount was measured by a thermal mass flow sensor, and displayed as a value at normal pressure and 25 ° C. conversion.

<Evaluation Criteria> Before showing the experimental results, the evaluation criteria for evaluating the experimental results will be described here.

The present inventors consider that an excellent dental air turbine handpiece is, of course, one having excellent torque (output) performance of the turbine rotor shaft. Then, the evaluation whether or not the torque (output) performance of the turbine rotor shaft is excellent is
We consider it preferable to evaluate according to the following criteria. (1) A maximum level of rotation speed that is desirable for the amount of air supply (entry) per unit time must be achieved. Needless to say, the torque increase (improvement of output) is preferably higher at a level where the maximum rotation speed of the turbine rotor shaft is preferable. Further, the maximum rotation speed of the turbine rotor shaft has a strong correlation with the amount of air supply (entry) per unit time. For this reason, the present inventors have found that the ratio of the maximum rotation speed (X) to the air supply amount (Y) per unit time, that is, the air supply amount efficiency (X / Y) is a realistic first evaluation criterion. I think. The inventor thinks that the evaluation standard is realistic because the approach of increasing the air supply amount (Y) per unit time in order to increase the maximum rotation speed (X) is an air supply system. This is because the above approach should be underestimated, because it imposes an excessive load on the existing air supply system and forces the existing air supply system to be changed (a new expensive capital investment is required due to lack of capacity). Needless to say, in the first evaluation standard, the dental air turbine handpiece having a high air supply efficiency (X / Y) can use existing equipment as an air supply system, It shares the effect that the air supply system (compressor, etc.) is not heavily loaded and the operating noise is low.

(2) Large cutting ability. What must be kept in mind when evaluating the experimental data with the first evaluation criterion is, for example, that the supply air amount (X) is small, and the turbine system has a moderate rotation speed (Y) (however, at a preferable level). Not) is obtained,
This means that it shows a high value as the efficiency of air supply amount (X / Y). Therefore, even if the above-mentioned dental air turbine handpiece having a good air-supply efficiency (X / Y), the rotational speed is low at the cutting work, which is the main work content of the handpiece. Has inferior cutting ability. Therefore, in evaluating the cutting amount performance, the present inventors have added the maximum rotation speed (X) showing a strong correlation with the cutting amount to the first evaluation criterion (X / Y), that is, the maximum rotation speed. The following efficiency against cutting amount weighted in (X) was set as the second evaluation standard. The efficiency against the cutting amount is (X) · (X /
Y) = X ² / Y. Needless to say, in the second evaluation standard, a dental air turbine handpiece having a high cutting efficiency (X ² / Y) has less cutting vibration and is capable of performing advanced dental treatment. In addition, it has the advantage of clinically releasing discomfort and pain. Further, even if a small turbine rotor is used, the same performance as the conventional product can be obtained, so that the handpiece can be further downsized.

Therefore, the following experimental results are (1) the efficiency (X / Y) against the air supply amount, which is the first evaluation criterion, and
(2) Efficiency against cutting amount (X ² /
Y), and should be comprehensively judged.

<Experimental Results and Consideration> (1) Experimental Results Table 1 below shows the experimental results obtained by using the above-described experimental apparatus. In each table, each item in the table means the following. (1) Method of the present invention (Experiment Nos. 1 to 3): means an experiment based on the experimental result of the method of the present invention. (2) Conventional method (Experiment Nos. 4 to 5): means an experiment using the experimental apparatus of the conventional method. (i) Experiment No. 4: It means an experiment using an experimental apparatus of a conventional method (FIGS. 22 to 23). (ii) Experiment No. 5: means an experiment using a USP type experimental device. (3) Air supply port (φ): Air supply port whose cross-sectional shape is circular (unit: mm). Diameter (φ). See FIG. (4) Exhaust port (e ₁ , e ₂ ): Exhaust port whose cross-sectional shape is rectangular. (Unit: mm). Vertical (e ₁ ) x horizontal (e ₂ ). Figure 15
reference. (5) Exhaust port (φ): Exhaust port whose cross-sectional shape is circular (unit: mm). Diameter (φ). See FIG. (6) d ₁ : Distance between the inner wall surface of the chamber and the turbine blade in the device of the present invention (see FIG. 16). d ₁ = 150
μm. (7) d ₁ ': Distance between the inner wall surface of the chamber and the turbine blade in the conventional system (see FIG. 19). d ₁ ′ = 11
50-600 μm. (8) Maximum rotation speed (X): Constant pressure air (1.0 kgf / c
The maximum speed of the turbine system (10 ⁴ rpm) when air is supplied under m ² ). (9) Amount of air supply (Y): The amount of air supply (inlet) to the turbine system, which is the value converted at 25 ° normal pressure (unit: l (liter) / min). (10) X / Y: First evaluation standard (air supply efficiency) (11) XX / Y: Second evaluation standard (cutting efficiency)

[0064]

[Table 1]

(2) Consideration of Experimental Results As is clear from Table 1 and as is clear from the above experimental results, the method of the present invention exhibits superior effects as compared with the conventional method and the USP method. . For example, as can be easily understood by comparing the method of the present invention with the conventional method, the rotation speed (in other words, torque) is significantly improved with a small amount of air supply (Experiment No. 4, 3480 thousand → Experiment No. 4). 2 of 57.
20,000 rpm), and in other words, the same rotation speed as the conventional one can be obtained with a significantly smaller supply pressure and supply amount than the conventional one. (Reduced noise) ・ The pressure resistance of the air supply tube can be reduced ・ The flexibility of the air supply tube can be increased and the operability can be improved ・ The power consumption of fluid pressurizing devices such as compressors can be saved. It is possible to achieve such effects. In addition, because the maximum rotation speed is greatly improved, a larger torque can be obtained than in the past, so that the machinability is good and the treatment is quick. Further, since a large torque can be obtained even with low fluid energy, it is possible to manufacture a portable handpiece driven by a fluid cylinder and a handpiece with a constant rotation speed (torque in other words) control system.

Furthermore, in the conventional method, the experiment N
As shown in o.4, even if the conventional system is downsized (the size is reduced by narrowing the interval d ₁ ′ to the interval d ₁ ), the performance improvement cannot be expected, and it is far beyond the present invention method. However, this clearly shows the difference between the two design ideas. That is, the air turbine handpiece of the system of the present invention can be miniaturized, and the present invention can realize a miniaturized and high performance small fluid drive turbine handpiece. On the other hand, as is clear from the experimental results of the present invention method and the USP method,
Although a certain improvement can be achieved in the USP system, the improvement effect is far below that of the present invention. In this respect, in addition to the above-described effect (miniaturization and high performance), the present invention is difficult to manufacture and economical because of providing two air supply passages (and thus two air supply ports) in the neck portion. It is possible to provide a dental air turbine handpiece with excellent performance without being disadvantaged.

Next, a second embodiment of the present invention will be described.
20 to 21 illustrate a dental air turbine handpiece (A) according to a second embodiment of the present invention.
20 is a partial vertical cross section of the dental air turbine handpiece (A) according to the second embodiment of the present invention as seen in the axial direction of the turbine rotor shaft, and FIG. 21 is a cross-sectional view taken along line BB of FIG. is there. In addition, in FIG. 20, the narrowing-down means (7b) arranged in the vicinity of the air supply port (7a) of the air supply system (7) is drawn in a perspective view in order to help understanding of the structure. It should be noted that The dental air handpiece (A) of the second embodiment is greatly different from the air handpiece (A) of the first embodiment described above in that the narrowing means (7b) of the air supply passageway (7) and the bearing portion (4). ), The other configurations are essentially the same for both. That is, in the narrowing means (7b) arranged in the air supply system (7) of the second embodiment, as shown in FIG. 20, the two air supply passages (71, 72) are connected to the air supply port (7a). ) Is a structure that is narrowed down in the vicinity of. Further, the structure of the bearing portion (4) used in the second embodiment is different from that of the bearing portion (4) in the first embodiment, which employs a ball (rolling) bearing mechanism using a ball bearing. The bearing part (4) of the second embodiment is different in that an air bearing mechanism utilizing an air flow (air layer) is adopted.

Bearing part (4) using the air bearing mechanism
Is a bearing (46) having a number of through holes (45) in the circumferential direction, and a shaft portion (31) (turbine rotor shaft (3)) extending from the inside of the bearing (46) to the side thereof. It may be integrated with). The bearing (46) is elastically held on the head peripheral side portion (12) by the bearing support member (47) on the outer periphery thereof. Further, in the second embodiment, in order to supply the air to the air bearing mechanism (the bearing (46)), as shown in FIG. 20, the air supply passage (7) is branched to the branch passages (7m, 7n). ) Is formed. The shaft portion (31), that is, the turbine rotor shaft (3), supplies air from the branch passage (7m, 7n) to the clearance between the bearing (46) and the shaft portion (31) through the through hole (45). , Through the layer of air supplied to the gap, it floats without contacting the bearing (46) and is rotatably supported. In the case of FIG. 20 of the second embodiment, the turbine blade (2) and the chamber (1
Spacing between the upper and lower inner wall surface of 1) (d ₁₎ has a shaft portion turbine blade (2) (the distance between the upper and lower surfaces of 31) (d ₁₎
It should be understood that using the method shown in the present invention,
Also in the dental handpiece (A) of the second embodiment, the same effect as that of the first embodiment can be exhibited.

[0069]

According to the present invention, a small fluid-driven turbine handpiece for dentistry or the like is constructed on the basis of a design concept completely different from the conventional one. In particular, the present invention provides a supply / exhaust system of a pressurized fluid to a turbine blade of a turbine rotor shaft arranged in a head chamber of the handpiece, and suppresses a diffusion component in the pressurized fluid supplied into the chamber. At the same time, immediately after the collision with the turbine blade, the pressurized fluid is immediately discharged from the chamber in order to prevent the rotation of the turbine blade in the chamber from being negatively affected. .

Due to the above-mentioned supply / discharge system, the small fluid-driven turbine handpiece of the present invention has the same supply pressure / supply amount of the pressurized fluid as compared with the conventional one.
The rotation speed of the turbine rotor shaft (torque in other words)
Can be improved.

By significantly improving the rotational speed of the turbine rotor shaft, the rotational noise is reduced (the noise generated by the device is reduced), the pressure resistance of the air supply tube is reduced, and the flexibility related to the former is reduced. Providing a portable handpiece such as a fluid cylinder drive method because the same torque as before can be obtained by improving the operability by using the air supply tube, the speed of treatment action under large torque, or low fluid energy Further, various excellent effects such as miniaturization of equipment can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a small (dental) air turbine handpiece of the present invention.

FIG. 2 is a longitudinal sectional view of a main part of a small (dental) air turbine handpiece according to the first embodiment of the present invention.

3 is a cross-sectional view taken along the line AA of FIG.

4 is a cross-sectional view taken along the line A ₁ -A ₁ of FIG.

FIG. 5 is a narrowing means (7b) according to the present invention related to FIG.
3 is a diagram for explaining the configuration of FIG.

FIG. 6 is a diagram for explaining a first modified example of the narrow-down means (7b) of the present invention.

FIG. 7 is a diagram for explaining a second modified example of the narrow-down means (7b) of the present invention.

FIG. 8 is a diagram for explaining a third modified example of the narrow-down means (7b) of the present invention.

FIG. 9 is a view for explaining a diffusion component of a pressurized air flow injected from a conventional air supply port.

FIG. 10 is a diagram illustrating a turbine blade of a first embodiment applied to a small (dental) air turbine handpiece of the present invention.

FIG. 11 is a diagram illustrating a turbine blade of a second embodiment applied to the small (dental) air turbine handpiece of the present invention.

FIG. 12 is a diagram illustrating a turbine blade of a third embodiment applied to a small (dental) air turbine handpiece of the present invention.

FIG. 13 is a diagram illustrating a turbine blade of a fourth embodiment applied to a small (dental) air turbine handpiece of the present invention.

FIG. 14 is a side view of an experimental device equivalent to the small-sized air handpiece according to the present invention, a part of which is a perspective view showing the air supply / exhaust system.

15 is a plan view (a) of the housing member (H ₁ ) of FIG. 14 and a sectional view (b) taken along the line DD.

16] EE in the axial direction of the air supply passage (7) in FIG.
It is a line sectional view.

FIG. 17 is a side view of an experimental device equivalent to a conventional air handpiece, in which a part is seen through to show an air supply / exhaust system.

FIG. 18 is a plan view (a) of the housing member (H ₁ ′) of FIG. 17 and a sectional view (b) taken along line FF.

FIG. 19 is an axial G- of the air supply passage (7 ′) of FIG. 17;
It is a G line sectional view (b).

FIG. 20 is a longitudinal sectional view of an essential part of a small (dental) air turbine handpiece according to a second embodiment of the present invention.

21 is a cross-sectional view taken along the line BB of FIG.

FIG. 22 is a longitudinal sectional view of a main part of a conventional medical (dental) air turbine handpiece.

23 is a cross-sectional view taken along the line CC of FIG.

FIG. 24 is a graph showing a correlation (theoretical value) between the supply air pressure and the supply speed in the air turbine.

FIG. 25 is a graph showing a correlation (theoretical value) between the supply air pressure and the supply air amount in the air turbine.

[Explanation of symbols]

A ......... Small (dental) air turbine handpiece A'according to the present invention A conventional medical (dental) air turbine handpiece H, H '... Head part G, G' ...... Grip part N, N '... ...... Neck part 1, 1' ... ...... Head 11, 11 '...... Chamber 2, 2' ... ...... Turbine blades 3, 3 '...... Turbine rotor shaft 4, 4 '... Bearings 5, 5' ... Tool (shaft) 6, 6 '... Neck body 7, 7' ... Air supply system 7a, 7a '... Air supply port 7b. ………… Narrow-down means 71, 71 ′ ………… Air supply passage 8, 8 ′ ………… Exhaust system 81, 81 ′ ………… Exhaust passage 8a, 8a ′ ………… Exhaust port (a), (B) ……… Pressurized air flow H ₁ , H ₂ , H ₃ , H ₁ ', H ₂ ', H ₃ '...
……………… Housing members that make up the head part 12, 12 '………… Peripheral side part 13, 13' ………… Cap part

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 5-131001 (JP, A) JP-A 64-25846 (JP, A) JP-A 63-206238 (JP, A) JP-A 53- 213596 (JP, A) Jitsukai Hei 5-95510 (JP, U) Jpn. Application No. 53-169009 (Jun. 55-87211) Micro film filming the details and drawings attached to the application ( JP, U) US Patent 3893242 (US, A) US Patent 4020556 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61C 1/05

Claims (17)

(57) [Claims] 1. The turbine blade (2) of a turbine rotor shaft (3) having a turbine blade (2) is arranged in a chamber (11) of the head (1), and the turbine blade (2) is arranged inside the head (1). Turbine rotor shaft (3)
Is a head portion (H) rotatably supported via a bearing portion (4) and a neck portion (N) connected to the head portion (H). A supply system (7) for supplying a pressurized fluid to a turbine blade (2) in the chamber (11) and a neck portion (N) having a discharge system (8) for discharging the pressurized fluid in the chamber (11). Small fluid drive turbine handpiece (A)
In (i). Inside the chamber (11) of the head (1)
The turbine blade (2) to be operated is (i) -1 . Height viewed in the axial direction of the turbine rotor shaft (3)
However, the upper and lower inner wall surfaces (111, 11) of the chamber (11)
The height of the turbine blade (2) is close to the height between 2) and (i) -2 .
It is close to the inner diameter of the inner wall surface (113) of the bar (11).
Consists of diameter, (ii). The supply system (7), together with having one supply port (7a), which comprises means (7b) refinement of the pressurized fluid in the vicinity portion of the supply opening (7a) (Iii). The exhaust system (8) has an outlet (8a).
It consists of objects and the arrangement position relationship of (iv). The one of the supply port of the supply system (7) (7a) and said <br/> discharge system outlet (8) (8a), supplied It is injected from the mouth (7a) and Tabinbu Les
The pressurized fluid immediately after it collides with the chamber (2)
(11) Immediately from the discharge port (8a) without circulating inside
To discharge the seat, a small fluid-driven turbine handpiece neighbor sites outlet (8a) to be one that is provided, and wherein the supply port (7a). 2. The narrowing-down means (7b) has a plurality of supply paths (71, 72, ...) Having a desired encounter angle (θ).
…………… 7n, n is an integer of 2 or more) Supply port (7a)
The small fluid-driven turbine handpiece according to claim 1, wherein the small-sized fluid-driven turbine handpiece is formed by merging at a portion in the vicinity of. 3. The constricting means (7b) reduces the diameter in a conical shape (cone shape) so as to have a desired encounter angle (θ) at a portion near the supply port (7) of one supply passage (71). The small fluid-driven turbine handpiece according to claim 1, which is formed by the above-mentioned method. 4. The small fluid-driven turbine handpiece according to claim 3, wherein the meeting angle (θ) is 5 ° to 40 °. 5. The discharge system (8) has a plurality of discharge paths of two or more (81, 82, ... 8n, n is an integer of 2 or more) and respective discharge ports (81a, 82a ,. The small fluid-driven turbine handpiece according to claim 1, which is constructed by having 8 na). 6. The size of the turbine blade (2) arranged in the chamber (11) of the head (1) is such that the turbine blade (2) and the chamber (11) are viewed in the axial direction of the turbine rotor shaft (3). Upper and lower inner wall surfaces (111, 1,
When the interval of 12) were d ₁ and a height of the turbine blade (2) is h, set the size of the turbine blades (2) such that the d ₁ is less than 1/10 the size of the h The miniature fluid-driven turbine handpiece according to claim 1, wherein 7. The miniature fluid-driven turbine handpiece according to claim 6 , wherein the distance d ₁ is 500 μm or less. 8. The miniature fluid-driven turbine handpiece according to claim 6 , wherein the distance d ₁ is 100 μm to 200 μm. 9. The size of the turbine blade (2) arranged in the chamber (11) of the head (1) is such that the turbine blade (2) and the chamber (11) when viewed in the axial direction of the turbine rotor shaft (3). Upper and lower inner wall surfaces (111, 1,
D ₁ spacing 12), and the outer periphery of the turbine rotor shaft (3) the turbine blade as viewed in a direction perpendicular to the axial direction of (2)
When the distance part and the peripheral inner wall surface (113) and the d _2, wherein d ₁ is set the size of the turbine blade (2) so that the size of more than 2.5 times the d ₂ A miniature fluid-driven turbine handpiece according to claim 1, wherein 10. The miniature fluid-driven turbine handpiece according to claim 9, wherein the distance d ₂ is 150 μm. 11. One supply port (7a) of the supply system (7)
The discharge port (8a) of the discharge system (8) and the discharge port (8a) are arranged in a positional relationship such that the discharge port (8a) is arranged at an adjacent portion immediately above and / or immediately below the supply port (7a). The small fluid-driven turbine handpiece according to item 1. 12. The small fluid-driven turbine handpiece according to claim 1, wherein the opening area of the discharge port (8a) is larger than the opening area of the single supply port (7a). 13. One supply port (7a) of the supply system (7)
2. The arrangement position of is arranged such that the pressurized fluid from the supply port (7a) is in contact with a substantially central portion of the turbine blade (2) when viewed in the axial direction of the turbine rotor shaft (3). The small fluid-driven turbine handpiece according to item 1. 14. The small fluid-driven turbine handpiece according to claim 1, wherein the bearing portion (4) is a ball bearing mechanism using a ball bearing. 15. The small fluid-driven turbine handpiece according to claim 1, wherein the bearing portion (4) has an air bearing mechanism by an air bearing. 16. Head (1) and neck body (6)
The small fluid-driven turbine handpiece according to claim 1, wherein is made of synthetic resin. 17. Medical and small fluid driven turbine handpiece according to any one of claims 1-16 for use in dental treatment.