JPH0416656Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an air turbine handpiece for dental treatment used for tooth cutting, and an internal contamination prevention device in the handpiece that is most suitable for preventing contamination of its operating mechanism.

[Conventional technology]

An example of an air turbine handpiece for dental treatment is shown in FIG. 5, in which high pressure (approximately 2 to 3 kg/cm ² )
By passing the air flow through the air supply pipe 3 and discharging it from the exhaust pipe 4, it is rotated at high speed (approximately 400,000 revolutions per minute) to drive the cutting tool 5 directly connected to the turbine. It has been done.

Furthermore, in order to prevent the cutting tool 5 from heating up and to wash away tooth debris when using the handpiece, cooling water is sprayed from an external water supply source through the water pipe 6 toward the cutting edge. Means is taken to atomize the cooling water by opening a chip air pack 7 that is placed in parallel with the water outlet.

By the way, with a handpiece in which the cutting tool 5 rotates at high speed during intraoral treatment, at the end of the treatment, etc.
To prevent dangers such as contact with the film of the cutting tool 5 when taking the piece out of the mouth, after stopping the air supply to the air turbine at the working position and confirming that the rotation of the cutting tool 5 has stopped, remove the piece out of the mouth. It has become a habit to take it out.

However, even if the supply of drive air to the air turbine rotating at high speed is stopped, the receiving blades 2 continue to rotate for a while due to their inertia. The air inside the tip of the handpiece will be sent out through the exhaust pipe 4, thereby creating a negative pressure inside the structure.

As a result, at the tip of the handpiece held in the working position, the cooling water adhering to the chuck of the cutting tool and other structural gaps becomes dirty water containing tooth debris, saliva, blood, and bacteria, as shown in Figure 5. As shown by the arrow, there is a risk of being inhaled and causing internal contamination.

Therefore, it is necessary to disinfect the handpiece after each use, but in the case of gas disinfection, which avoids disinfection by chemical solutions or heat treatment that damage the delicate internal structure of the handpiece, it is difficult to obtain sufficient sterilization effect. It takes about 2 to 3 hours for disinfection to clean the water, making work efficiency extremely poor.
Therefore, it is virtually impossible for medical practitioners to disinfect this type of handpiece.

Therefore, there were problems in preventing blood-borne diseases such as hepatitis B and AIDS.

As a measure to improve the disinfection means for such handpieces, a small amount of high-pressure air is sent to the tip structure of the piece through the air supply pipe 3 etc. even after the work with the handpiece is finished, to maintain the part at a positive pressure with respect to the atmosphere. Accordingly, a method has been proposed that prevents sewage from entering through the gaps and the like, thereby preventing internal contamination and cleaning and disinfecting the outside of the piece.

[Problem that the invention attempts to solve]

By the way, according to the above-mentioned internal pressure maintaining means, when maintaining pressure is supplied from the air supply pipe or the branch pipe of the chip air pipe, the air supplied at this time still escapes through the exhaust pipe, so this loss can be compensated for. To obtain the minimum effective internal pressure by supplementing
A considerable amount of air must be fed even after the work is finished, and as a result, the rotation of the air turbine, that is, the cutting tool, cannot be completely stopped, as well as the waste of air needed to maintain this internal pressure. Therefore, in a dual handpiece unit configured to share an air source, an air source powerful enough not to interfere with the use of the other handpiece is required.

In addition, as another configuration, when air is supplied from the exhaust pipe to maintain the internal pressure, the above-mentioned outflow loss from the exhaust pipe can be prevented, but on the other hand, if air is supplied to the exhaust pipe in the opposite direction to that during operation, For this purpose, a three-way valve is installed in the exhaust pipe circuit for flow path conversion, and this valve is constructed with a solenoid valve that can be controlled from the outside, so the equipment configuration is large. It tends to be bulky, and in terms of functionality, since air continues to be supplied through the exhaust pipe, it is possible to stop the air turbine from spinning due to inertia immediately after work is completed, but when the turbine is reversed Since it starts to rotate, it is not possible to stably stop the rotation of the cutting tool.

Furthermore, in this case, it is not possible to prevent sewage from entering the check air pipe, so separate measures must be taken to prevent this.

For these reasons, as a means of preventing contamination due to internal pressurization after the operation of this type of handpiece has stopped, it is necessary to simultaneously send the minimum amount of low-pressure air necessary to maintain internal pressure to all supply and discharge pipes, including the tip air pipe. This is effective.

However, such a device configuration that enables air supply to each pipe requires a large number of valve structures to be arranged in each pipe circuit, and in particular, the valve body in the exhaust pipe circuit that reversibly reverses the direction of air supply is arranged in three directions. In a conventional configuration in which a valve is required, and the valve is constructed using a solenoid valve, the device inevitably becomes bulky and heavy.

On the other hand, since various structural parts of dental treatment equipment have already been functionally compacted in order to adapt to many uses, it is difficult to assemble a new contamination prevention mechanism like the one described above. In addition, there are many restrictions on weight, and for this reason, it is strongly required that such additional structures be made as small and lightweight as possible.

Therefore, the present invention eliminates the drawbacks of conventional devices,
In addition, another object of the present invention is to develop an internal contamination prevention device for a handpiece that can sufficiently achieve the various functions required of this type of device, and can also reduce the size and weight of the device.

[Means for Solving the Problems] In order to achieve this objective, the present invention is equipped with an air turbine supply circuit, an exhaust circuit thereof, a water injection circuit for cooling, and a tip air circuit for spraying. In the handpiece operating mechanism, the third
A low pressure air circuit is provided, and the air supply circuit to the air supply circuit is configured to be switchable via an air supply shuttle valve which is connected to a high pressure drive air circuit at one end and the low pressure air circuit at the other end. The drive air circuit and the low pressure air circuit are connected to pilot pressure ports at both ends, and the exhaust circuit is configured to be able to be switched between supply and discharge through a three-way exhaust valve having a free piston structure, and the chip air circuit is connected to one end of the exhaust circuit. is configured such that the air supply circuit to the chip air circuit can be switched via a shuttle valve for chip air connected to the chip air circuit and the low pressure air circuit is connected to the other end, and these valve structures and the main parts of the switching circuit are configured to be switchable. An internal contamination prevention device for a handpiece is proposed which is integrally constructed in a single unit.

[Effect]

When the drive air circuit, which supplies a large amount of high-pressure air, and the chip air circuit, which supplies a small amount of high-pressure air, are both in the air supply state, the air supply shuttle valve and chip air shuttle valve in these circuits: The drive air circuit is connected to the air turbine air supply circuit, and the chip air circuit is connected to the air turbine supply circuit, against the pressure acting force of the low pressure air circuit, while the three-way exhaust valve is connected to the drive air circuit. It is in a switching position where it receives a high supply pressure and resists the pressure acting force of the low-pressure air circuit, and forms an exhaust circuit that discharges the air that has driven the turbine into the atmosphere.

Therefore, under the supply of air from the drive air circuit and the tip air circuit, the handpiece operates normally like the conventional device.

Next, when the air supply in the drive air circuit and the chip air circuit is stopped, the air supply shuttle valve and the chip air shuttle valve, which had been receiving the supply pressure of these circuits, will each receive the supply pressure of the low pressure air circuit. The circuit is switched to connect the air turbine supply circuit and the chip air supply circuit, and the exhaust three-way valve is switched to connect the low pressure air circuit to the exhaust circuit.

As a result, low-pressure air is simultaneously supplied to the air turbine air supply circuit, the tip air supply circuit, and the exhaust circuit at the tip of the handpiece.

The low-pressure air sent to the air turbine supply circuit and exhaust circuit exerts a braking effect on the turbine, and also acts to maintain the internal pressure of the turbine structure at the tip of the handpiece after the operation is completed. do.

In addition, since the three-way exhaust valve operates using the supply pressure of the drive air circuit and the supply pressure of the low-pressure air circuit as pilot pressure, the switching circuit consisting of the above means can be entirely constituted by a pneumatic circuit, This allows the circuit arrangement or internal contamination prevention device to be formed in a single unit.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a circuit diagram showing an embodiment of the present invention, including a drive air circuit 10 and a chip air circuit 11.
In addition, a low-pressure air circuit 12 is provided under the air switch 13 to supply a pressure of about 0.1 kg/cm ² .

The drive air circuit 10 is provided with an air supply shuttle valve 15 which is connected to one end and the low pressure air circuit 12 is connected to the other end with the flow rate regulating throttle 14 interposed, and an outlet of the valve 15 is provided. An air supply connector 16 is provided at.

Similarly, the tip air circuit 11 consists of a circuit that connects to a tip air connector 18 via a tip air shuttle valve 17 which is connected to one end and the low pressure air circuit 12 is connected to the other end.

In contrast to each of the circuit configurations on the air supply side, the exhaust side circuit is configured by a three-way exhaust valve 19.

That is, the three-way valve 19 is a pressure-sensitive operated valve that makes a difference between the supply pressure of the drive air circuit 10 and the supply pressure of the low-pressure air circuit 12 as a pilot pressure, and one port to which the exhaust connector 20 is connected is connected to the other port. A discharge path 21 to the atmosphere and a low pressure air circuit 1 are provided at the two-way switching port.
2 are connected to each other.

The air supply connector 16, the tip air connector 18, and the exhaust connector 20 are connected to the air supply pipe 3, the tip air pipe 7, and the exhaust pipe 4 (see FIG. 5) in the hand piece 22.
An air supply tube 23, a chip air tube 24, and an exhaust tube 25 are connected to the piece 22, and a water supply tube 26 extending from a pressurized water source 27 is connected to the water pipe 6 of the piece 22.

Additionally, reference numeral 28 indicates a noise muffling muffler attached to the discharge passage 21, 10a indicates an air supply port, 11a indicates a chip air port, and 12a indicates a low pressure air port.

A switching circuit having such a configuration is constructed as a unit structure part _U1 .
This device is constructed as a single unit with a double structure in which another unit structure U ₂ that shares the low-pressure air circuit 12 is juxtaposed with this, and there is a connection between these two structures U ₁ and U ₂ . The circuit 29 is constructed with a shuttle valve 30 interposed, and a monitoring pressure gauge 31 is attached to the outlet of the valve 30.

One embodiment of this single unit structure is shown in FIGS. 2-4.

FIG. 2 is a perspective plan view of the circuit component shown in the first diagram in the unit structure; As shown in the figure, the structure basically consists of two layers, upper and lower. In the figure, the upper layer structure is shown by a chain line, the lower layer structure is shown by a dotted line, and structural parts common to each functional part of the circuit are given the same symbol. It has been done.

That is, the unit structures U ₁ and U ₂ each consist of three metal blocks A, B, and C due to the cutting process, and the central block A is commonly formed with blocks B and C on both sides.
are assembled together by tightening screws 32, 32...

The central block A has a small diameter passage 33 and a large diameter passage 34 extending laterally from the chip air port 11a and the drive air port 10a, which are opened at the upper and lower positions of the right side surface.

On the other hand, the outer block C is provided with a passage 35 that passes through the upper layer sideways, the left end is processed into a connection port 36 for the low pressure air circuit 12, and the right end is a needle valve 14a whose opening degree can be finely adjusted from the outside. The above-mentioned flow rate adjustment throttle 14 consisting of the above-mentioned flow rate adjustment throttle 14 is attached.

This throttle 14 adjusts the internal pressure (flow rate) each time depending on the type of handpiece used.

The intermediate block B, which is sandwiched between the central block A and the outer block C, which have horizontal passages, has several vertical holes that communicate the passages 33 or 34 with the other passage 35. However, these holes are machined into each of the aforementioned shuttle valves 15, 17 and three-way valve 19.

That is, the spherical valve 17a is slid into the cylindrical hole drilled in the upper left layer of the intermediate block B in FIG. 15a is slidably fitted to constitute the air supply shuttle valve 15, and furthermore, pistons 37a and 37b at both ends are connected by support rods 38 to a cylinder hole opened in the lower layer parallel to the shuttle valve 15. A piston valve 19a is slidably fitted to form a three-way exhaust valve.

The three-way valve 19 includes the free piston valve 19a.
A one-way port 39 connected to the exhaust connector 20 is provided on the cylinder hole wall at a position through which the piston 37a passes during the stroke movement, and an exhaust port 40 to the atmosphere is provided at approximately the middle position of the stroke movement, and the piston valve When 19a is in one switching position, these one port 39 and discharge port 40 are connected to piston 37a.
and 37b, and are configured to communicate with each other through a gap between the supporting rods 38.

In the block B, there is a horizontal passage 41 that communicates between the upper chip air shuttle valve 17 and the chip air connector 18 provided on the right side wall.
and a lateral passage 42 communicating between the one port 39 of the exhaust shuttle valve 19 and the exhaust connector 20 provided on the right side wall are provided in the upper layer, and the air supply shuttle valve 15 and an opening in the right side wall are provided in the lower layer. A passage 43 communicating with the connected air supply connector 16 and a vertical hole passage 44 extending from the passage 43 toward the intermediate block A are opened, and this is connected to the other unit structure.
The circuit 30 is directed to U ₁ or U ₂ .

In addition, the central block A has the above-mentioned structural part U ₁
A shuttle valve 29 is provided in which a spherical valve 29a is slidably fitted into a vertical cylindrical hole that communicates between the passages 44 of U2 and _U2 .

Reference numeral 45 designates a mounting port for the pressure gauge 31, which is opened at an intermediate position of the shuttle valve 29.

On the other hand, a pressure reducing valve 46 is integrally assembled on the left end of the central block A, and receives the original pressure supplied from the external compressor as the drive air and chip air supply source at the port 47.
The low pressure air reduced through the pressure reducing valve 45 is supplied to the connection port 36 of the outer block C through the circuit 12 with the intervention of the air switch 13.

According to this embodiment, when the handpiece is operated, the pressure air sent into the low-pressure air circuit 12 through the drive air port 10a, the tip air port 11a, and the air switch 13 placed in the normal circuit state causes each valve structure to be Due to the difference in the supply pressures, the spherical valve 17a of the chip air shuttle valve 17 is pushed up toward the low pressure air circuit 12, and the piston valve 19a of the exhaust three-way valve 19 is pushed up above the low pressure side. The air supply shuttle valve 15 is also in the circuit state shown in the first diagram, in which the spherical valve 15a is pressed against the low-pressure side valve seat, and in the state shown by the unit structure _U1 in FIG.

In this state, the pressure air sent from the drive air port 10a passes through the shuttle valve 15 from the drive air circuit 10 (passage 34) to the air supply connector 16 (via the passage 43), and the air supply connected to the connector 16 The air is ejected from the tip of the air supply pipe 3 of the hand piece 22 via the tube 23, hits the air receiving blade 2, is pushed around, and passes through the exhaust pipe 4, the exhaust tube 25, and the exhaust connector 20, and is discharged from the passage 42 on three sides for exhaust. It reaches one port 39 of the valve 19, passes through the intermediate gap of the piston valve 19a of the valve 19, and is discharged from the exhaust port 40 through the muffler 28 into the atmosphere.

On the other hand, the pressure air sent from the tip air port 11a is blown out from the tips of the tip air circuit 11 (passage 33), the shuttle valve 17, the tip air connector 18 (via the passage 41), the tube 24, and the pipe 7, and the water pressure source Water injection tube 2 from 27
6 and the tip fountain of cooling water sent through the water pipe 6 is atomized.

After the tooth treatment operation is completed by the cutting tool 5 through the turbine operation caused by the rotation of the receiving blade 2, when the injection of drive air, chip air, and cooling water is stopped, the shuttle valves 15, 17
and the three-way valve 19 connects the low pressure air circuit 12 (passage 3
5) The unit structure _U2 is switched to the state shown in the figure by the supply pressure.

That is, the valve 17 is connected to the tip air connector 18.
Low pressure air is sent from the three-way valve 19 to the exhaust connector 20 through the passage 41, and low pressure air is also sent to the exhaust connector 20 from the three-way valve 19 through the passage 42. A slightly smaller amount (lower pressure) of air is sent to the exhaust connector 20 by the flow rate adjustment throttle 14 (needle valve 14a) than the amount of air (air pressure) sent to the exhaust connector 20.

As a result, low-pressure air is weakly blown out from the tip of the tip air pipe 7 in the hand piece 22 to keep the inside of the pipe 7 at a positive pressure, and at the same time, low pressure air is supplied to the turbine structure to lower the air pressure on the air supply pipe 3 side. Since air is sent from both sides of the pipe 3 and the exhaust pipe 4, it applies a brake to the receiving blade 2, which tends to continue rotating due to inertia, to quickly stop it, and
Since the low pressure air sent into the structure from the exhaust pipe 4 leaks to the outside from the assembly gap, the exhaust pipe 4
There is no flow of air toward the air supply pipe 3 from the side,
Therefore, there is no need to reversely rotate the receiving blade 2 after it has stopped.

Note that the air switch 13 in the low-pressure air circuit 12 is normally kept open, not only when securing positive pressure inside the piece after completing the aforementioned handpiece work, but also when disinfecting the outside of the piece by soaking it in a disinfectant solution or the like. During cleaning, maintaining the internal pressure under the switch circuit prevents chemical liquid from entering the piece and protects the internal mechanism from the chemical liquid. This prevents unnecessary waste of pressurized air.

[Effect of idea]

As described above, according to the device of the present invention, in the air turbine handpiece operating mechanism, in addition to the drive air circuit for driving the turbine and the tip air circuit for spraying cooling water, the supply air of the supply air circuit of these air circuits is Compared to the above, a low-pressure air circuit with sufficiently low air pressure and air flow is provided, and the air flow of the low-pressure air circuit is also sent to the exhaust pipe as well as the air supply pipe and tip air pipe at the tip of the handpiece. As a result, it is possible to brake the turbine using pressure air from both the supply and exhaust pipes after work has been completed, making it possible to stop the turbine suddenly. By keeping the internal pressure of the unit at a positive pressure, it is possible to prevent contaminated liquid from entering through gaps, etc., and it is possible to prevent internal contamination and contamination of the entire instrument connected to it.
Since it is sufficient to disinfect only the outside of the piece, it eliminates the technical difficulties of sterilizing the inside of the piece and the limitations of long-term gas sterilization. This has the effect that the hand piece can be disinfected in a short time by immersing the tip of the piece in a disinfectant solution.

Moreover, since each circuit switching valve mechanism for supplying the low-pressure air into the handpiece is composed of a two-way valve consisting of a shuttle valve and a free piston type three-way valve, these valve bodies can be used for driving air and air. As a pressure-sensitive valve that uses low-pressure air as the pilot pressure, it can be configured as a block together with an air supply passage in a single unit.This makes it possible to reduce the weight and bulk of the entire device, and to replace existing devices of this type. It can be easily assembled to dental instruments, and by having a dual handpiece configuration with two handpieces, one handpiece can be immersed in a disinfectant solution after work is completed. However, since treatment can be continued with the other handpiece, the time loss and labor required for disinfecting these handpieces can be saved, making the device of this invention extremely effective as a device for preventing internal contamination of the handpiece. It is what it is.

[Brief explanation of drawings]

FIG. 1 is an air switching circuit diagram showing an embodiment of the device of the present invention, FIG. 2 is a plan view showing the circuit components of the device of the present invention, FIG. 3 is a bottom side view, and FIG. 5 shows a right side view, and FIG. 5 is a longitudinal sectional view showing the tip structure of the handpiece to which the device of the present invention is applied. Explanation of symbols, 1...Handpiece tip, 2...
Air receiving blade, 3... Air supply pipe, 4... Exhaust pipe, 5... Cutting tool, 6... Water pipe, 7... Chip air pipe, 10... Drive air circuit, 11... Chip air circuit, 12 ...Low pressure air circuit, 13...Air switch, 14...Flow rate adjustment throttle, 15...Air supply shuttle valve, 17
... Shuttle valve for tip air, 19 ... Three-way valve for exhaust, 22 ... Hand piece, U ₁ , U ₂ ... Unit structure.

Claims (1)

[Claims for Utility Model Registration] (1) In a handpiece operating mechanism equipped with an air supply circuit for an air turbine, an exhaust circuit thereof, a water injection circuit for cooling, and a tip air circuit for spraying thereof,
A third low-pressure air circuit is provided, and the air supply circuit to the air supply circuit can be switched via an air supply shuttle valve that has one end connected to the high-pressure drive air circuit and the other end connected to the low-pressure air circuit. configure,
The drive air circuit and the low-pressure air circuit are configured to be able to be switched between supply and discharge of the exhaust circuit through a three-way exhaust valve having a free piston structure in which the drive air circuit and the low-pressure air circuit are connected to pilot pressure ports at both ends;
The air supply circuit to the chip air circuit is configured to be switchable via a chip air shuttle valve having one end connected to the chip air circuit and the other end connected to the low pressure air circuit, and the valve structure and its switching. An internal contamination prevention device for a handpiece, characterized in that the main parts of the circuit are integrated into a single unit. (2) The device for preventing internal contamination in a handpiece as set forth in claim 1, wherein a throttle for adjusting the air supply amount is disposed in the low-pressure air circuit toward the air supply shuttle valve. (3) An internal contamination prevention device for a handpiece according to claim 1, wherein the low-pressure air circuit has an air on/off switch. (4) The device for preventing internal contamination in a handpiece according to claim 1, which is constructed by configuring the single unit as two units.