Dental handpiece control system

Abstract

A dental handpiece control system (2) is provided with: a gas supply flow path (60) for supplying compressed gas from a compressed gas source (50) to turbine blades (24) provided in a dental handpiece (20); an exhaust flow path (70) that exhausts the compressed gas that has rotated the turbine blades (24); an exhaust pressure detection unit (110) that detects an exhaust pressure, which is the pressure of the compressed gas in the exhaust flow path (70); a target exhaust pressure setting unit that sets a target exhaust pressure; and an air supply pressure control unit that controls the air supply pressure, which is the pressure of the compressed air supplied to the turbine blades (24), the air supply pressure control unit controlling the air supply pressure such that the exhaust pressure detected by the exhaust pressure detection unit (110) matches the target exhaust pressure.

Description

TECHNICAL FIELD

[0001] The present application relates to a technique of controlling a dental handpiece that works using compressed gas to rotate a turbine blade. BACKGROUND

[0002] Patent Documents 1, 2, and 3 describe a control system that controls a dental handpiece having a turbine blade. In such a control system, the rotational speed of the turbine blade that has generated a load is maintained constant using a detected exhaust pressure.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: Japanese Patent No. 5314746

[0006] Patent Document 2: U.S. Patent No. 3865505

[0007] Patent Document 3: Japanese Patent Application Publication No. 2017-221300 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] In actual dental treatment, the dental handpiece needs to perform a high-torque action at a high speed of rotation when a restoration (metal or the like) is to be removed, or a low-torque action at a low speed of rotation when fine cutting or the like is performed. In this regard, in the existing control system, the turbine blade is controlled to a constant rotational speed, and thus the rotational speed cannot be changed according to the content of the dental treatment.

[0010] The present application was made in view of the above-described problems, and aims to provide a dental handpiece control system that can appropriately cope with the situation of dental treatment.

[0011] SOLUTION TO THE PROBLEM

[0012] To solve the above-described problems, the dental handpiece control system of the present application is characterized by including: a supply flow path that supplies compressed gas from a compressed gas source to a turbine blade provided in a dental handpiece; an exhaust flow path that exhausts the compressed gas after rotating the turbine blade; an exhaust pressure detection section that detects the pressure of the compressed gas in the exhaust flow path, i.e., an exhaust pressure; a target exhaust pressure setting section that sets a target exhaust pressure; and a supply pressure control section that controls the pressure of the compressed gas supplied to the turbine blade, i.e., a supply pressure, the supply pressure control section controlling the supply pressure in such a manner that the exhaust pressure detected by the exhaust pressure detection section coincides with the target exhaust pressure.

[0013] EFFECT OF THE INVENTION

[0014] According to the present application, the rotational speed of the turbine blade can be changed by setting the target exhaust pressure, and the situation of the dental treatment can be appropriately coped with. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a perspective view schematically showing a dental treatment unit to which a dental handpiece control system according to an embodiment of the present application is applied.

[0016] Figure 2 is a perspective view schematically showing a hose, a mounting portion, a dental handpiece, and a drill bit.

[0017] Figure 3 is a view schematically showing a flow path of compressed gas in a dental handpiece control system according to an embodiment of the present application.

[0018] Figure 4 is a block diagram schematically showing a dental handpiece control system according to an embodiment of the present application.

[0019] Figure 5 is a graph showing an example of a time characteristic of an exhaust pressure in a dental handpiece, and is a different graph showing a time characteristic of an exhaust pressure of each kind of dental handpiece.

[0020] Figure 6 is a graph showing an example of a time characteristic of an exhaust pressure in a dental handpiece, and is a graph showing a time characteristic of an exhaust pressure in a normal dental handpiece and a time characteristic of an exhaust pressure in a dental handpiece having a failure.

[0021] Figure 7 is a graph showing an example of a control method of a proportional valve based on an exhaust pressure, and is a graph for explaining a case where a target exhaust pressure is set to a target exhaust pressure initial value and a case where the target exhaust pressure is set based on an operation.

[0022] Figure 8 is a graph showing an example of a control method of a proportional valve based on an exhaust pressure, and is a graph for explaining a case where a target exhaust pressure is automatically reset when a load has increased.

[0023] Figure 9 is a graph showing an example of a control method of a proportional valve based on an exhaust pressure, and is a graph for explaining a case where a target exhaust pressure is automatically reset when a load has decreased.

[0024] Figure 10 is a flowchart for explaining a determination method of a kind of a dental handpiece and normality or abnormality, and a determination method of a kind of a failure, which are performed by a dental handpiece control system according to an embodiment of the present application.

[0025] Figure 11 is a graph showing an example of a control method of a proportional valve based on exhaust pressure, and is a graph for explaining a case where a target exhaust pressure is automatically set. DETAILED DESCRIPTION

[0026] Embodiments of the present application are explained in detail with reference to the accompanying drawings. In the following description, identical elements are given identical reference numerals, and overlapping explanations are omitted.

[0027] < Dental treatment unit >

[0028] As shown in Figure 1 , the dental treatment unit 1 to which the embodiments of the present application relate is a unit used when a user, i.e., a doctor, performs dental treatment on a patient. In the dental treatment unit 1, a dental handpiece control system 2 (refer to Figure 3 and Figure 4 ) is applied. The dental treatment unit 1 has a chair unit 3, a base unit 4, a first support portion 5, a treatment table 6, a second support portion 7, an assistant table 8, and a foot controller 9 as a basic structure.

[0029] < Chair unit >

[0030] The chair unit 3 has a chair main body 3a for a patient.

[0031] < Base unit >

[0032] The base unit 4 is disposed to the side of the chair unit 3. The base unit 4 has a spittoon placement table 4a, a spittoon 4b disposed on the spittoon placement table 4a, and a water supply port 4c for supplying water to a cup for gargling.

[0033] < First support portion >

[0034] The first support portion 5 supports the treatment table 6 in such a manner that the treatment table 6 is movable around the chair unit 3. The first support portion 5 has arm portions 5a and 5b disposed in series. One end portion (base end portion) of the arm portion 5a is connected to a housing portion of the base unit 4 through a joint portion, and the other end portion (front end portion) of the arm portion 5a is connected to the arm portion 5b through a joint portion. One end portion (base end portion) of the arm portion 5b is connected to the arm portion 5a through a joint portion, and the other end portion (front end portion) of the arm portion 5b is connected to the treatment table 6 through a joint portion.

[0035] < Treatment table >

[0036] The treatment table 6 is used by a user, i.e., a doctor (dentist). The treatment table 6 has a table 6a, a hanger 6b, a plurality of sets of hoses 6c, a mounting portion 6d, a dental handpiece 20, and a drill 30 (refer to Figure 2); display unit 6e; and operation unit 6f.

[0037] <<Workbench>>

[0038] The workbench 6a is a part used to hold items and other items needed by the dentist to perform dental treatments.

[0039] <<Hanging>>

[0040] The hanger 6b is a part used to suspend and hold the dental handpiece 20 mounted on the mounting part 6d. The hanger 6b is configured to hold multiple dental handpieces 20 individually.

[0041] <<Hose>>

[0042] The hose 6c is configured such that compressed gas (e.g., compressed air) supplied to the dental handpiece 20 and compressed gas discharged from the dental handpiece 20 can flow through the hose 6c.

[0043] Installation Department

[0044] Mounting part 6d is a metal component installed at the front end of the flexible tube 6c, configured to allow the dental handpiece 20 to be installed and removed.

[0045] <<Dental Handpieces and Drills>>

[0046] like Figure 2 As shown, the dental handpiece 20 and drill 30 are tools (an example of an instrument) held by a dentist and used for the treatment (cutting, etc.) of a patient's teeth. In this embodiment, the dental handpiece 20 is detachably mounted relative to the mounting portion 6d by pressing the front end of the mounting portion 6d into the base end of the dental handpiece 20. Examples of uses for the dental handpiece 20 and drill 30 include: cavity formation for caries removal; formation of proximal surfaces of teeth; formation of abutment teeth for restorations or resin fillings; fine cutting or grinding of crowns, inserts, or resin fillings; and removal of filled restorations or synthetic resins. Dental handpieces and drill 30 of the type corresponding to these uses are selected for use. The dental handpiece 20 and drill 30 will be described in detail later.

[0047] <<Display Department>>

[0048] The display unit 6e consists of a display and the like, and is based on the control unit 120 (see below) described later. Figure 4 The control signals are used to display images for the doctor to see.

[0049] <<Operations Department>>

[0050] The operation unit 6f consists of buttons, a touch panel, etc., and the control unit 120 (see below) is described later. Figure 4 Output control signals based on the doctor's (manual) actions.

[0051] <Second support part>

[0052] As Figure 1 illustrated, the second support part 7 movably supports the assistant workbench 8 around the chair unit 3. The second support part 7 has arm parts 7a and 7b arranged in series. One end (proximal end) of the arm part 7a is connected to the housing part of the base unit 4 through a joint part, and the other end (distal end) of the arm part 7a is connected to the arm part 7b through a joint part. One end (proximal end) of the arm part 7b is connected to the arm part 7a through a joint part, and the other end (distal end) of the arm part 7b is connected to the assistant workbench 8 through a joint part.

[0053] <Assistant workbench>

[0054] The assistant workbench 8 is used by an assistant (dental assistant) who is a user. The assistant workbench 8 has a workbench 8a, a hanger 8b, and a plurality of sets of a hose 8c, a mounting part 8d, and an instrument 40.

[0055] <<Workbench>>

[0056] The workbench 8a is a site for placing articles and the like necessary for an assistant to assist dental treatment.

[0057] <<Hanger>>

[0058] The hanger 8b is a site for hanging and holding the instrument 40 mounted to the mounting part 8d.

[0059] <<Hose>>

[0060] The hose 8c is configured so that compressed gas (for example, compressed air) and / or water supplied to the instrument 40 and the compressed gas discharged from the instrument 40 can flow through the hose 8c.

[0061] <<Mounting part>>

[0062] The mounting part 8d is a metal member mounted to the distal end of the hose 8c and is configured so that the instrument 40 can be attached and detached.

[0063] <<Instrument>>

[0064] The instrument 40 is a tool held by the assistant and used for auxiliary (suction, etc.) of treatment of the teeth of a patient. As the instrument 40, a vacuum suction head, a syringe, and the like can be listed.

[0065] <Floor controller>

[0066] The floor controller 9 is an operation part operated by operation (treading, etc.) by the foot of the doctor. The floor controller 9 outputs a control signal corresponding to the operation result of the doctor to the control part 120 (on-off valve control part 122) described later.

[0067] <Control system for dental handpiece>

[0068] As shown in Figure 3 and Figure 4 , a control system for dental handpiece 2 is a system that controls the pressure of compressed gas supplied to a dental handpiece. The control system for dental handpiece 2 has: a dental handpiece 20 and a drill bit 30 (refer to Figure 2 ); a compressed gas source 50; a supply flow path 60; an exhaust flow path 70; an on-off valve 80; a proportional valve 90; a setting detection section 100; an exhaust pressure detection section 110; and a control section 120.

[0069] <Control system for dental handpiece>

[0070] As shown in Figure 2 , the dental handpiece 20 is detachably attached to the attachment section 6d, and is an instrument for cutting a patient's tooth by being held and operated by a doctor. As shown in Figure 3 , the dental handpiece 20 has, in order from the upstream side to the downstream side, a handpiece-internal supply flow path 21, a turbine chamber 22, and a handpiece-internal exhaust flow path 23 as flow paths of compressed gas.

[0071] The dental handpiece 20 has a turbine blade 24 as a member that converts the pressure of compressed gas into rotational force. The turbine blade 24 is disposed in the turbine chamber 22 and is rotatably supported by a shaft section and a bearing, neither of which is shown.

[0072] In such a dental handpiece 20, most of the compressed gas supplied from the handpiece-internal supply flow path 21 to the turbine chamber 22 is exhausted to the handpiece-internal exhaust flow path 23. In addition, a part of the compressed gas supplied to the turbine chamber 22 is exhausted from the turbine chamber 22 formed in the head section of the dental handpiece 20 to the outside of the dental handpiece 20.

[0073] That is, with respect to the pressure of compressed gas, the following relationship holds.

[0074] [Supply pressure] ≒ [Exhaust pressure] + [Head exhaust pressure]

[0075] The supply pressure is the pressure of compressed gas that flows in the supply flow path 60 (handpiece-internal supply flow path 21). The exhaust pressure is the pressure of compressed gas that flows in the exhaust flow path 70 (handpiece-internal exhaust flow path 23). The head exhaust pressure is the pressure of compressed gas that is exhausted from the turbine chamber 22 to the outside of the dental handpiece 20, rather than to the exhaust flow path 70.

[0076] <Drill bit>

[0077] As shown in Figure 2 , the drill bit 30 is a tool that actually cuts a patient's tooth, and is detachable with respect to the dental handpiece 20 and is coupled to the turbine blade 24 (refer toFigure 3 ) is integrally rotatably installed.

[0078] <compressed gas source>

[0079] As shown in Figure 3 , the compressed gas source 50 is a tank that stores compressed gas (for example, compressed air) that is a power source of the turbine blade 24, an air compressor that generates compressed gas by compressing gas, or the like.

[0080] <gas supply flow path>

[0081] The gas supply flow path 60 is a flow path for supplying the compressed gas stored in the compressed gas source 50 to the dental handpiece 20. The gas supply flow path 60 has, in order from the upstream side (the compressed gas source 50 side) to the downstream side (the dental handpiece 20 side), an upstream side gas supply flow path 61, a flow path switching section 62, and a plurality of sets of downstream side gas supply flow paths 63 and handpiece inner gas supply flow paths 21.

[0082] <<upstream side gas supply flow path>>

[0083] The upstream side gas supply flow path 61 (part of) is disposed in the base unit 4 and the first support section 5 (refer to Figure 1 ). One end portion (upstream side end portion) of the upstream side gas supply flow path 61 is connected to the compressed gas source 50, and the other end portion (downstream side end portion) of the upstream side gas supply flow path 61 is connected to the flow path switching section 62.

[0084] <<flow path switching section>>

[0085] The flow path switching section 62 is disposed in the housing of the treatment table 6 (refer to Figure 1 ). The flow path switching section 62 has a valve block having a pipe that branches from the upstream side gas supply flow path 61 to the plurality of downstream side gas supply flow paths 63, and a plurality of control valves provided at a branched position of the valve block. The control valve is an electromagnetic valve that can switch an open / close state based on a control signal from the control section 120.

[0086] <<downstream side gas supply flow path>>

[0087] The downstream side gas supply flow path 63 is disposed in the hose 6c and the mounting section 6d (refer to Figure 2 ).

[0088] <exhaust flow path>

[0089] The exhaust flow path 70 is a flow path for discharging the compressed gas that has passed through the turbine blade 24 (refer to Figure 2) a flow path for the compressed gas after rotation to be discharged to the outside. The discharge flow path 70 has, from the upstream side (dental handpiece 20 side) to the downstream side, in order: a plurality of sets of the handpiece internal discharge flow path 23 and the upstream side discharge flow path 71; a flow path merging portion 72; and a downstream side discharge flow path 73.

[0090] <<Upstream side discharge flow path>>

[0091] The upstream side discharge flow path 71 is provided in the hose 6c and the mounting portion 6d (refer to Figure 2 ).

[0092] <<Flow path merging portion>>

[0093] The flow path merging portion 72 is provided in the housing of the treatment table 6 (refer to Figure 1 ). The flow path merging portion 72 has: a valve block having a pipe that merges a plurality of upstream side discharge flow paths 71 with respect to the downstream side discharge flow path 73; and a plurality of check valves provided at portions of the valve block before merging. The check valves are one-way valves that allow the flow of compressed gas from the upstream side to the downstream side and prohibit the flow of compressed gas from the downstream side to the upstream side.

[0094] <<Downstream side discharge flow path>>

[0095] The downstream side discharge flow path 73 (part of) is disposed in the first support portion 5 and the base unit 4 (refer to Figure 1 ). One end portion (upstream side end portion) of the downstream side discharge flow path 73 is connected to the flow path merging portion 72, and the other end portion (downstream side end portion) of the downstream side discharge flow path 73 is exposed from the first support portion 5 (refer to Figure 1 ), and is configured to be able to discharge compressed gas to the outside.

[0096] <On-off valve>

[0097] The on-off valve 80 is a normally closed electromagnetic valve disposed at the gas outlet of the compressed gas source 50 or the upstream side supply flow path 61. The on-off valve 80 is configured to be able to switch between a closed valve state in which the flow of compressed gas is prohibited and an open valve state in which the flow of compressed gas is allowed.

[0098] <Proportional valve>

[0099] The proportional valve 90 is an electromagnetic valve disposed at a position downstream of the on-off valve 80 in the upstream side supply flow path 61 or a position upstream of the position at which the flow path branches in the flow path switching portion 62. The proportional valve 90 is disposed in the treatment table 6 (refer to Figure 1The proportional valve 90 is configured to steplessly change the opening degree of the flow path through which the compressed gas flows (the ratio of the opening area to the total opening area under any movement of the valve body in the cross-sectional area of ​​the flow path viewed from the direction of the compressed gas flow), and is initially set to an appropriate opening state that allows the compressed gas to flow.

[0100] <Set up detection unit>

[0101] like Figure 4 As shown, the detection unit 100 is installed to detect whether the hanger 6b (see reference) is in use. Figure 1 The dental handpiece 20 is set with (whether it is suspended) (whether it is removed from the hanger 6b) (see reference). Figure 1 The sensor is configured to detect whether a set or removed dental handpiece is required for each of the multiple dental handpieces 20. The detection unit 100 outputs the detection results to the control unit 120.

[0102] <Exhaust Pressure Testing Department>

[0103] The exhaust pressure detection unit 110 detects pressure in the exhaust flow path 70 (in this embodiment, the downstream exhaust flow path 73) (see reference). Figure 3 The exhaust pressure sensor measures the pressure of the compressed gas flowing through the system. The exhaust pressure detection unit 110 outputs the detection result (exhaust pressure) to the control unit 120. The exhaust pressure detection unit 110 is located on the treatment workbench 6 (see reference). Figure 1 Inside the shell.

[0104] In this embodiment, the exhaust pressure detection unit 110 is a semiconductor sensor equipped with a Wheatstone bridge circuit, which is composed of multiple strain gauges made of piezoresistors. This semiconductor sensor converts changes in the resistance of the Wheatstone bridge circuit into voltage changes for measurement, thereby detecting the exhaust pressure. The exhaust pressure detection unit 110 is not limited to a semiconductor sensor; pressure sensors capable of detecting exhaust pressure, such as thin-film metal sensors, capacitive sensors, fiber optic sensors, and vibratory sensors, can be used as the exhaust pressure detection unit 110.

[0105] <Control Department>

[0106] The control section 120 is configured by a circuit, and / or a CPU (Central Processing Unit), a ROM (Read-Only Memory), a RAM (Random Access Memory), an input / output circuit, and the like. The control section 120 has a storage section 121, an on-off valve control section 122, a control valve control section 123, an exhaust pressure time characteristic calculation section 124, a determination section 125, a target exhaust pressure setting section 126, a comparison section 127, and a proportional valve control section 128 as functional sections.

[0107] <<Storage Section>>

[0108] In the storage section 121, a kind and normal determination database 121a and a failure determination database 121b are stored. In addition, in the storage section 121, a target exhaust pressure database 121c is stored.

[0109] <<Kind and Normal Determination Database>>

[0110] The kind and normal determination database 121a is a database used for determining the kind of the dental handpiece 20 to which the compressed gas is supplied and from which the compressed gas is exhausted. In addition, the kind and normal determination database 121a is a database used for determining whether the dental handpiece 20 to which the compressed gas is supplied and from which the compressed gas is exhausted is normal (whether a failure has occurred). In the kind and normal determination database 121a, the kind of the dental handpiece 20 is stored in association with the time characteristic of the exhaust pressure of the normal dental handpiece 20 of the kind. As the time characteristic of the exhaust pressure in the kind and normal determination database 121a, an integral value (lower limit value and upper limit value) of the exhaust pressure from the start of rotation of the turbine blade 24 to a prescribed time T, an exhaust pressure (lower limit value and upper limit value) at a time point that has elapsed the prescribed time T, a curve (a curve indicating the lower limit value and a curve indicating the upper limit value) indicating the change over time of the exhaust pressure, and the like can be listed.

[0111] Here, the dental handpiece 20 from the start of rotation of the turbine blade 24 to the time point that has elapsed the prescribed time T is a so-called no-load rotation state in which the dental handpiece 20 is not pressed against the teeth of the patient and no load acts.

[0112] As Figure 5As shown, the curves representing the time-varying exhaust pressure P1 in a dental handpiece 20 of type 1, the time-varying exhaust pressure P2 in a dental handpiece 20 of type 2, and the time-varying exhaust pressure P3 in a dental handpiece 20 of type 3 are all different. In this embodiment, in the type and normality determination database 121a, as a time characteristic of the exhaust pressure used to determine the type of dental handpiece 20, the integral values ​​of exhaust pressure P1, P2, and P3 from the start of rotation (time t0) to a time point (time t1) after a predetermined time T are stored for each type of dental handpiece 20. Alternatively, in the type and normality determination database 121a, as a time characteristic of the exhaust pressure used to determine the type of dental handpiece 20, the values ​​of exhaust pressure P1, P2, and P3 from the start of rotation (time t0) to a time point (time t1) after a predetermined time T are stored for each type of dental handpiece 20.

[0113] like Figure 6 As shown, in the database 121a for type and normality determination, the lower limit value P of the exhaust pressure, representing the time characteristic of the exhaust pressure used to determine whether the dental handpiece 20 is normal, is stored for each type of dental handpiece 20. This value represents the exhaust pressure from the start of rotation (time t0) to a time point (time t1) after a predetermined time T. L The curve showing the change over time and the upper limit value P representing the exhaust pressure. H The curve showing the changes over time.

[0114] <<Database for Fault Diagnosis>>

[0115] like Figure 4 As shown, the fault determination database 121b is used to determine the types of faults in the dental handpiece 20 that supplies compressed gas and exhausts the compressed gas. In the fault determination database 121b, the types of faults occurring in the dental handpiece 20 are stored in association with the time characteristics of the exhaust pressure of the dental handpiece 20 where the fault occurred. As the time characteristics of the exhaust pressure in the fault determination database 121b, curves representing the time-varying changes in exhaust pressure can be listed.

[0116] like Figure 6 As shown, in the fault determination database 121b, the time characteristics of the exhaust pressure used to determine the type of fault of the dental handpiece 20 are stored according to each fault type, representing the exhaust pressure P from the start of rotation (time t0) to the time point (time t1) after a specified time T. W1 P W2 The curve showing the changes over time. Furthermore, in Figure 6 The diagram shows two curves representing the exhaust pressure P corresponding to the fault. W1 PW2 The number of curves is not limited to this, however.

[0117] The prescribed time T is set to a time (for example, 400 to 600 ms) until the time when the proportional valve 90 is opened and the on-off valve 80 is opened at time to in a state where the proportional valve 90 is maintained at a prescribed opening degree (for example, an opening degree at the start of control in feedback control using the target exhaust pressure initial value) without performing feedback control using the target exhaust pressure (target exhaust pressure initial value).

[0118] <<Target Exhaust Pressure Database>>

[0119] As shown in FIG. 12, the target exhaust pressure database 121c is a database that holds, for each type of dental handpiece 20, a target of the exhaust pressure detected by the exhaust pressure detection section 110, that is, a target exhaust pressure. In the target exhaust pressure database 121c, a target exhaust pressure initial value at the start of control is stored for each type of dental handpiece 20. In addition, in the target exhaust pressure database 121c, as target exhaust pressures that can be selected and set by the operation of the doctor (manual operation), a plurality of target exhaust pressures are stored for each type of dental handpiece 20. Such a plurality of target exhaust pressures are higher than the target exhaust pressure initial value. Figure 4 The target exhaust pressure can also be configured to have a lower limit value and an upper limit value.

[0120] Further, as the target exhaust pressure initial value, a rotational speed (for example, 200,000 rpm, 300,000 rpm, 400,000 rpm) of the turbine blade 24 (refer to FIG. 1) that roughly corresponds to the target exhaust pressure initial value can be stored in association with the target exhaust pressure initial value, or such a rotational speed can be displayed on the display section 6e.

[0121] Figure 3

[0122] In addition, in the target exhaust pressure database 121c, as for automatic control, the variation range (absolute value) of the exhaust pressure from the exhaust pressure in the steady state and the directionality of the variation (increase or decrease), and the change amount and the directionality of the change (increase or decrease) of the target exhaust pressure can be stored as a table or the like in association with each type of dental handpiece 20.

[0123] <<On-Off Valve Control Section>>

[0124] The on-off valve control section 122 acquires the on-off valve control signal from the foot controller 9 (refer to FIG. 1) and the target exhaust pressure from the target exhaust pressure database 121c (refer to FIG. 12). Figure 1 ​​The control signal (operation result) is used to control the opening and closing valve 80 based on the operation result. When the doctor steps on the foot pedal controller 9, the opening and closing valve 80 is opened, and when the doctor stops stepping on the foot pedal controller 9, the opening and closing valve 80 is closed.

[0125] <<Control Valve Control Section>>

[0126] The control valve control unit 123 receives a control signal (detection result) from the setting detection unit 100 housed in the hanger 6b, and controls the control valve based on the detection result, thereby setting the flow path switching unit 62 to only be able to operate on the dental handpiece 20 (see reference) removed from the hanger 6b and held by the dentist. Figure 1 The state of the supplied compressed gas.

[0127] <<Exhaust Pressure Time Characteristics Calculation Department>>

[0128] The exhaust pressure time characteristic calculation unit 124 acquires the exhaust pressure detected by the exhaust pressure detection unit 110, calculates the time characteristic of the acquired exhaust pressure, and outputs the calculation result to the determination unit 125. Examples of the time characteristic of the exhaust pressure include: starting at the dental handpiece 20 (refer to...). Figure 2 The integral value of the exhaust pressure during a specified time T from the time the compressed gas is supplied, the value of the exhaust pressure at the end of the specified time T, and a curve representing the time-varying change of the exhaust pressure during the specified time T, etc.

[0129] During the training phase of the database 121a for class and normal determination, the exhaust pressure-time characteristic calculation unit 124 calculates the exhaust pressure-time characteristic of the normal dental handpiece 20 (refer to the database 121a) with known class. Figure 2 Installed at mounting section 6d (refer to) Figure 2 In the state of ( ), the time characteristics of the exhaust pressure are calculated. The exhaust pressure time characteristic calculation unit 124 stores the type of dental handpiece 20 and the time characteristics of the exhaust pressure of that dental handpiece 20 in association in the type and normal determination database 121a. Here, the exhaust pressure time characteristic calculation unit 124 can obtain the type of dental handpiece 20 based on the operation results of the doctor or others on the operation unit 6f.

[0130] During the training phase of the fault determination database 121b, the exhaust pressure-time characteristic calculation unit 124 calculates the fault type in the dental handpiece 20 (refer to...). Figure 2 Installed at mounting section 6d (refer to) Figure 2the state of the dental handpiece 20, the time characteristic of the exhaust pressure is calculated. The exhaust pressure time characteristic calculation section 124 stores the kind of the failure and the time characteristic of the exhaust pressure of the dental handpiece 20 in the failure determination database 121b in association with each other. Here, the exhaust pressure time characteristic calculation section 124 can acquire the kind of the failure based on the operation result of the operator 6f by the doctor or the like.

[0131] <<determination section>>

[0132] The determination section 125 acquires the time characteristic of the exhaust pressure calculated by the exhaust pressure time characteristic calculation section 124, and determines the kind and / or the failure of the dental handpiece 20 (refer to FIG. 6) by comparing the acquired time characteristic of the exhaust pressure with the time characteristic of the exhaust pressure stored in the storage section 121. Figure 2 The determination section 125 outputs the determination result of the kind and / or the failure of the dental handpiece 20 to the display section 6e and causes the display section 6e to display.

[0133] The determination section 125 determines that the kind associated with the coincident time characteristic is the kind of the currently used dental handpiece 20 in the case where the calculated time characteristic of the exhaust pressure coincides with (or falls between the lower limit value and the upper limit value of) the time characteristic stored in the kind and normal determination database 121a.

[0134] The determination section 125 determines that the currently used dental handpiece 20 is normal in the case where the calculated time characteristic of the exhaust pressure (here, the curve representing the change over time) falls between the lower limit value P L and the upper limit value P H of the time characteristic of the exhaust pressure stored in the kind and normal determination database 121a during the prescribed time T. In addition, the determination section 125 determines that the currently used dental handpiece 20 is abnormal (a failure has occurred) in the case where the calculated time characteristic of the exhaust pressure (here, the curve representing the change over time) deviates from the lower limit value P L and the upper limit value P H of the time characteristic of the exhaust pressure stored in the kind and normal determination database 121a during the prescribed time T (even if the deviation is temporary in the present embodiment).

[0135] The determination section 125 determines the kind of the failure by comparing the calculated time characteristic of the exhaust pressure (here, the curve representing the change over time) with the time characteristic of the exhaust pressure stored in the failure determination database 121b during the prescribed time T in the case where it is determined that the currently used dental handpiece 20 has a failure.

[0136] <<target exhaust pressure setting section>>

[0137] The target exhaust pressure setting section 126 sets a target value of the exhaust pressure detected by the exhaust pressure detecting section 110, that is, a target exhaust pressure, and outputs the set target exhaust pressure to the comparison section 127.

[0138] The target exhaust pressure setting section 126 can set one of the target exhaust pressures selected from among a plurality of target exhaust pressures stored in advance in the target exhaust pressure database 121c as the target exhaust pressure for feedback control at the time of manual operation.

[0139] In addition, the target exhaust pressure setting section 126 can calculate the amount of change and the directionality (increase or decrease) of the target exhaust pressure based on the variation amplitude (absolute value) and the directionality (increase or decrease) of the exhaust pressure from the exhaust pressure in the stable state at the time of automatic control. In this case, the target exhaust pressure setting section 126 can substitute the target exhaust pressure in the stable state and the calculated amount of change and directionality (increase or decrease) of the target exhaust pressure into a formula set in advance to calculate a new target exhaust pressure, and set the calculated target exhaust pressure again as the target exhaust pressure for feedback control.

[0140] In addition, the target exhaust pressure setting section 126 can refer to the target exhaust pressure database 121c using the variation amplitude (absolute value) and the directionality (increase or decrease) of the exhaust pressure from the exhaust pressure in the stable state at the time of automatic control to read the amount of change and the directionality (increase or decrease) of the target exhaust pressure corresponding to the variation amplitude (absolute value) and the directionality (increase or decrease) of the exhaust pressure from the exhaust pressure in the stable state from the target exhaust pressure database 121c. In this case, the target exhaust pressure setting section 126 can calculate a new target exhaust pressure based on the target exhaust pressure in the stable state and the read amount of change and directionality (increase or decrease) of the target exhaust pressure, and set the calculated target exhaust pressure again as the target exhaust pressure for feedback control.

[0141] <<Comparison Section>>

[0142] The comparison section 127 acquires the target exhaust pressure set by the target exhaust pressure setting section 126 and the exhaust pressure detected by the exhaust pressure detecting section 110, and compares the acquired target exhaust pressure and exhaust pressure. In more detail, the comparison section 127 calculates the difference (exhaust pressure - target exhaust pressure) between the exhaust pressure and the target exhaust pressure as a comparison result, and outputs the calculated comparison result (difference) to the proportional valve control section 128.

[0143] <<Proportional Valve Control Section (Supply Pressure Control Section)>>

[0144] The proportional valve control unit 128 is an example of a supply pressure control unit that controls the pressure of the compressed gas supplied to the turbine blades 24, i.e., the supply pressure. The proportional valve control unit 128 acquires the comparison result from the comparison unit 127 and controls the proportional valve 90 based on the acquired comparison result. By controlling the proportional valve 90, the proportional valve control unit 128 changes the pressure of the compressed gas supplied to the dental handpiece 20, i.e., the supply pressure, so that the exhaust pressure detected by the exhaust pressure detection unit 110 matches the target exhaust pressure. When the exhaust pressure detected by the exhaust pressure detection unit 110 is lower than the target exhaust pressure (exhaust pressure - target exhaust pressure < 0), the proportional valve control unit 128 increases the opening of the proportional valve 90, thereby increasing both the supply and exhaust pressures, bringing the exhaust pressure closer to and matching the target exhaust pressure. When the exhaust pressure detected by the exhaust pressure detection unit 110 is higher than the target exhaust pressure (exhaust pressure - target exhaust pressure > 0), the proportional valve control unit 128 reduces the opening of the proportional valve 90, thereby lowering the supply pressure and exhaust pressure, so that the exhaust pressure approaches and matches the target exhaust pressure.

[0145] That is, the target exhaust pressure setting unit 126, the comparison unit 127, and the proportional valve control unit 128 constitute a feedback control unit that performs feedback control on the proportional valve 90 based on the exhaust pressure detected by the exhaust pressure detection unit 110.

[0146] Furthermore, the proportional valve control unit 128 controls the air supply pressure according to the type of dental handpiece 20 determined by the determination unit 125. In this embodiment, the target exhaust pressure setting unit 126 manually or automatically sets the target exhaust pressure according to the type of dental handpiece 20 determined by the determination unit 125, and the proportional valve control unit 128 controls the air supply pressure based on such target exhaust pressure.

[0147] <Setting the initial target exhaust pressure and feedback control of the proportional valve>

[0148] like Figure 7 As shown, at the start of control, the target exhaust pressure setting unit 126 reads the initial target exhaust pressure value P associated with the type of dental handpiece 20 used from the target exhaust pressure database 121c. T1 The target exhaust pressure setting unit 126 will read the initial value P of the target exhaust pressure. T1 Set as the target exhaust pressure.

[0149] The comparison unit 127 compares the exhaust pressure P detected by the exhaust pressure detection unit 110. E and the initial value of the target exhaust pressure P T1The comparison result is output to the proportional valve control section 128. The proportional valve control section 128 controls the proportional valve 90 in such a manner that the detected exhaust pressure P E is in agreement with the target exhaust pressure initial value P T1 . Further, the supply pressure P S is changed over time in such a manner that it shows a value greater than the exhaust pressure P E accompanied by the control of the proportional valve 90. That is, in a state where the exhaust pressure P E is in agreement with the target exhaust pressure initial value P T1 (P E =P E1 =P T1 ), the supply pressure P S is greater than the exhaust pressure P E1 (P S =P S1 ).

[0150] <Setting of target exhaust pressure based on operation (manual operation) and feedback control of proportional valve>

[0151] The target exhaust pressure setting section 126 switches the setting method of the target exhaust pressure between the method based on the operation and the automatic method based on the operation result of the operation section 6f by the doctor. In the case where the target exhaust pressure is set based on the operation, the target exhaust pressure setting section 126 reads a plurality of target exhaust pressures associated with the kind of the dental handpiece 20 used from the target exhaust pressure database 121c stored in advance in the storage section 121, and causes the display section 6e to display the plurality of target exhaust pressures read. The target exhaust pressure setting section 126 selects one target exhaust pressure from among the plurality of target exhaust pressures (P TA , P TB , P TC ) based on the operation result of the operation section 6f by the doctor who sees the display section 6e, and sets the selected target exhaust pressure as the target exhaust pressure for the feedback control. Further, the target exhaust pressure setting section 126 can also be configured to cause the display section 6e to display the rotational speed (for example, 200,000 rpm, 300,000 rpm, 400,000 rpm) of the turbine blade 24 (refer to Figure 3 ) stored in association with the target exhaust pressure initial value as described above. In this case, the target exhaust pressure setting section 126 sets the target exhaust pressure associated with the selected rotational speed as the target exhaust pressure for the feedback control.

[0152] The comparison section 127 compares the exhaust pressure P E detected by the exhaust pressure detection section 110 with the target exhaust pressure (P TAP TB P TC The proportional valve control unit 128 compares the detected exhaust pressure P with any one of the parameters and outputs the comparison result to the proportional valve control unit 128. Based on this comparison result, the proportional valve control unit 128 adjusts the detected exhaust pressure P... E With the target exhaust pressure (P) TA P TB P TC The proportional valve 90 is controlled in a manner consistent with any one of the following methods. Additionally, the supply pressure P... S Accompanied by the control of proportional valve 90, to indicate the specific exhaust pressure P E The value of the exhaust pressure at the large head changes over time.

[0153] For the target exhaust pressure P TA Exhaust pressure P under controlled conditions EA and gas supply pressure P SA Based on the target exhaust pressure P TB Exhaust pressure P under controlled conditions EB and gas supply pressure P SB and based on the target exhaust pressure P TC Exhaust pressure P under controlled conditions EC and gas supply pressure P SC The following relationship holds true.

[0154] P TA >P TB >P TC

[0155] P EA >P EB >P EC

[0156] P SA >P SB >P SC

[0157] Automatic target exhaust pressure setting and proportional valve feedback control.

[0158] like Figure 8 and Figure 9 As shown, when the target exhaust pressure is automatically set, the target exhaust pressure setting unit 126 sets the exhaust pressure P. E When the steady state changes, based on the exhaust pressure P E The target exhaust pressure is reset based on the magnitude of the change. As described above, the method for setting the new target exhaust pressure can be either using a pre-set formula or using the target exhaust pressure database 121c.

[0159] Here, the exhaust pressure detection unit 110 periodically (e.g., every tens of milliseconds) detects the exhaust pressure P. E And output. The control unit 120 acquires such exhaust pressure P each time. E Control is executed in real time. The control unit 120 (target exhaust pressure setting unit 126) sets the exhaust pressure P based on the acquired exhaust pressure. E If the number of times is the same (or between the lower and upper limits of the target exhaust pressure), it is determined to be exhaust pressure P. E It is in a stable state. Furthermore, the control unit 120 (target exhaust pressure setting unit 126) sets the acquired exhaust pressure P... E When the value changes from the steady state (or deviates from the lower and upper limits of the target exhaust pressure), it is determined to be exhaust pressure P. E The steady state has changed, so the target exhaust pressure has been reset.

[0160] like Figure 8 As shown, when the dentist increases the pressure of the dental handpiece 20 on the teeth, the exhaust pressure P increases due to the increased load acting on the dental handpiece 20 (turbine blade 24). E The pressure decreases. The target exhaust pressure setting unit 126 sets the exhaust pressure P. E When the pressure decreases from a steady state, the exhaust pressure P E The target exhaust pressure is reset by adjusting the magnitude (absolute value) of the change.

[0161] The comparison unit 127 compares the exhaust pressure P detected by the exhaust pressure detection unit 110. E The pressure is compared with the target exhaust pressure, and the comparison result is output to the proportional valve control unit 128. Based on this comparison result, the proportional valve control unit 128 adjusts the detected exhaust pressure P... E The proportional valve 90 is controlled in a manner consistent with the target exhaust pressure. Additionally, the supply pressure P... S Accompanied by the control of proportional valve 90, to indicate the specific exhaust pressure P E The value of the exhaust pressure at the large head changes over time.

[0162] For exhaust pressure P E The variation range D (absolute value), and the target exhaust pressure P set based on the variation range D. TD Based on the target exhaust pressure P TD Exhaust pressure P under controlled conditions ED and gas supply pressure P SD Exhaust pressure P E The variation range E (absolute value), and the target exhaust pressure P set based on the variation range E. TE Based on the target exhaust pressure PTE Exhaust pressure P under controlled conditions EE and gas supply pressure P SE and exhaust pressure P E The variation range F (absolute value), and the target exhaust pressure P set based on the variation range F. TF Based on the target exhaust pressure P TF Exhaust pressure P under controlled conditions EF and gas supply pressure P SF The following relationship holds true.

[0163] D > E > F

[0164] P TD >P TE >P TF

[0165] P ED >P EE >P EF

[0166] P SD >P SE >P SF

[0167] like Figure 9 As shown, when the dentist reduces the pressure of the dental handpiece 20 on the teeth, the exhaust pressure P decreases because the load acting on the dental handpiece 20 (turbine blade 24) is reduced. E Increase. The target exhaust pressure setting unit 126 sets the exhaust pressure P. E When the pressure increases from a steady state, the exhaust pressure P E The target exhaust pressure is reset by adjusting the magnitude (absolute value) of the change.

[0168] The comparison unit 127 compares the exhaust pressure P detected by the exhaust pressure detection unit 110. E The pressure is compared with the target exhaust pressure, and the comparison result is output to the proportional valve control unit 128. Based on this comparison result, the proportional valve control unit 128 controls the proportional valve 90 in a manner that makes the detected exhaust pressure match the target exhaust pressure. Furthermore, the supply pressure P... S Accompanied by the control of proportional valve 90, to indicate the specific exhaust pressure P E The value of the exhaust pressure at the large head changes over time.

[0169] For exhaust pressure P E The variation range G (absolute value), and the target exhaust pressure P set based on the variation range G. TG Based on the target exhaust pressure P TG Exhaust pressure P under controlled conditionsEG and the supply air pressure P SG , the exhaust air pressure P E , the variation range H (absolute value) of the exhaust air pressure P TH , the target exhaust air pressure P TH , the exhaust air pressure P EH and the supply air pressure P SH , and the variation range I (absolute value) of the exhaust air pressure P E , the target exhaust air pressure P TI , the exhaust air pressure P TI , the exhaust air pressure P EI and the supply air pressure P SI , the following relationships are established.

[0170] G > H > I

[0171] P TG < P TH < P TI

[0172] P EG < P EH < P EI

[0173] P SG < P SH < P SI

[0174] Further, in Figure 9 , in order to make the curves easy to understand, the supply air pressures P SG , P SH , and P SI are respectively described at lower positions than the exhaust air pressures P EG , P EH , and P EI . In fact, the supply air pressure P SG is higher than the exhaust air pressure P EG , the supply air pressure P SH is higher than the exhaust air pressure P EH , and the supply air pressure P SI is higher than the exhaust air pressure P EI .

[0175] <Operation Example>

[0176] Next, an operation example of the dental handpiece control system 2 involved in the embodiment of the present application, and a use example of the dental handpiece 20 by a doctor will be described with reference to the flowchart of Figure 10 and the curve graphs of Figure 11 (appropriately refer to Figures 1-4 ).

[0177] As shown in FIG. 6, if the dentist holds the dental handpiece 20 and takes it out from the hanger 6b, the control valve control section 123 controls the control valve of the flow path switching section 62 based on the detection result of the setting detection section 100 (YES in Step S1). Based on such control, the flow path switching section 62 becomes a state in which the compressed gas can flow to the dental handpiece 20 taken out from the hanger 6b and the compressed gas cannot flow to the other dental handpiece 20 set to the hanger 6b. Figure 10

[0178] Next, if the dentist steps on the foot controller 9, the on-off valve control section 122 opens the on-off valve 80, and the proportional valve control section 128 controls the opening amount of the proportional valve 90 in such a manner that the exhaust pressure P E corresponding to the target exhaust pressure initial value P T1 . Based on such control, the compressed gas flows in the supply flow path 60, the turbine chamber 22, and the exhaust flow path 70, the turbine blade 24 and the drill bit 30 rotate due to such compressed gas, and become a state in which the patient's teeth can be cut (YES in Step S2). In this state, the dental handpiece 20 (drill bit 30) is spaced apart from the patient's teeth, and the turbine blade 24 becomes a no-load rotation state in which the turbine blade 24 rotates without acting on the load from the patient's teeth at least during the time T.

[0179] Here, the exhaust pressure time characteristic calculation section 124 calculates the time characteristic of the exhaust pressure P E of the turbine blade 24 in the no-load rotation state based on the exhaust pressure P E detected by the exhaust pressure detection section 110.

[0180] The determination section 125 determines the kind of the dental handpiece 20 in use by comparing the time characteristic of the exhaust pressure P E calculated by the exhaust pressure time characteristic calculation section 124 with the time characteristic of the exhaust pressure P E stored in the kind and normality determination database 121a (Step S3).

[0181] Next, the determination section 125 determines whether the dental handpiece 20 in use is normal (whether a failure has occurred) by comparing the time characteristic of the exhaust pressure P E calculated by the exhaust pressure time characteristic calculation section 124 with the time characteristic of the exhaust pressure P E corresponding to the kind of the dental handpiece 20 in use, which is stored in the kind and normality determination database 121a (Step S4).

[0182] ​When it is determined in step S4 that the dental handpiece 20 in use has failed, the determination section 125 determines the kind of failure of the dental handpiece 20 in use by comparing the time characteristic of the exhaust pressure P E calculated by the exhaust pressure time characteristic calculation section 124, and the time characteristic of the exhaust pressure P E stored in the failure determination database 121b (step S5). Next, the determination section 125 causes the display section 6e to display the kind of failure of the dental handpiece 20 determined (step S6).

[0183] When it is determined in step S4 that the dental handpiece 20 in use is normal, and after step S6 is executed, if the doctor sets the dental handpiece 20 in the hanger 6b, the control valve control section 123 returns the control valve of the flow path switching section 52 to the initial state based on the detection result of the setting detection section 100 (in step S7: "Yes"). Next, the determination section 125 clears the determination result of the kind of the dental handpiece 20 (step S8). That is, the determination section 125 continues to hold the determination result of the kind of the dental handpiece 20 until the setting detection section 100 detects that the dental handpiece 20 is set in the hanger 6b.

[0184] In addition, after it is determined in step S4 that the dental handpiece 20 in use is normal, during a period until the setting detection section 100 detects that the dental handpiece 20 is set in the hanger 6b in step S7, as shown in Figure 11 , the target exhaust pressure setting section 126, the comparison section 127, and the proportional valve control section 128 perform feedback control on the proportional valve 90. Here, the target exhaust pressure setting section 126 automatically re-sets the target exhaust pressure based on the change in the exhaust pressure P E from the stable state in the case where automatic control is selected due to the operation of the doctor on the operation section 6f.

[0185] First, after a predetermined time elapses in a state where the exhaust pressure P E detected by the exhaust pressure detection section 110 coincides with the target exhaust pressure initial value P T1 , that is, a so-called stable state (initial stage Al) is reached, the doctor starts cutting processing by pressing the dental handpiece 20 (and the drill bit 30) against the teeth of the patient.

[0186] Here, if the doctor strengthens the pressing of the dental handpiece 20 (and the drill bit 30) against the teeth of the patient, the exhaust pressure (the exhaust pressures P E at times t3, t5, t7) detected by the exhaust pressure detection section 110 becomes larger than the exhaust pressure (the exhaust pressures P E) low (decrease). In this case, the target exhaust pressure setting section 126 re-sets the target exhaust pressure (lower limit value P T2L , P T3L , P T4L and upper limit value P T2H , P T3H , P T4H ) in such a manner that the greater the variation range (absolute value of the decrease amount) of the exhaust pressure, the higher the target exhaust pressure. The proportional valve control section 128 performs feedback control on the proportional valve 90 (1st stage Bl, 2nd stage B2 and 3rd stage B3 of the steady state under automatic control) in such a manner that the exhaust pressure detected by the exhaust pressure detection section 110 falls between the lower limit value and the upper limit value of the re-set target exhaust pressure.

[0187] On the other hand, if the dentist weakens the pressing of the dental handpiece 20 (and the drill bit 30) against the patient's tooth, the exhaust pressure (exhaust pressure P E at time t9) detected by the exhaust pressure detection section 110 becomes higher (increase) than the exhaust pressure (exhaust pressure P E at time t8) of the steady state. The target exhaust pressure setting section 126 re-sets the target exhaust pressure (lower limit value P T5L and upper limit value P T5H ) in such a manner that the greater the variation range (absolute value of the increase amount) of the exhaust pressure, the lower the target exhaust pressure. The proportional valve control section 128 performs feedback control on the proportional valve 90 (4th stage B4 of the steady state under automatic control) in such a manner that the exhaust pressure detected by the exhaust pressure detection section 110 falls between the lower limit value and the upper limit value of the re-set target exhaust pressure.

[0188] In addition, although not illustrated, the target exhaust pressure setting section 126, in a case where the control based on the operation is selected due to the operation of the operator 6f by the dentist, reads a plurality of target exhaust pressures corresponding to the kind of the dental handpiece 20 held by the dentist from the target exhaust pressure database 121c, and causes the display section 6e to display the plurality of target exhaust pressures read. The dentist selects one target exhaust pressure from the plurality of target exhaust pressures displayed by the display section 6e by operating the operator 6f. The target exhaust pressure setting section 126 acquires the operation result of the operator 6f, and sets the target exhaust pressure corresponding to such an operation result as a new target exhaust pressure. The proportional valve control section 128 performs feedback control on the proportional valve 90 in such a manner that the exhaust pressure P E detected by the exhaust pressure detection section 110 coincides with the re-set target exhaust pressure. Furthermore, the target exhaust pressure setting section 126 can also cause the display section 6e to display the turbine blade 24 (refer toFigure 3 ) of the turbine blade 24 (and the drill bit 30) in accordance with the situation (load, etc.). In this case, the target exhaust pressure setting portion 126 sets the target exhaust pressure associated with the selected rotational speed as the target exhaust pressure for feedback control.

[0189] The dental handpiece control system 2 according to the embodiment of the present application includes a gas supply passage 60 that supplies compressed gas from a compressed gas source 50 to a turbine blade 24 provided in a dental handpiece 20, an exhaust passage 70 that exhausts the compressed gas after rotating the turbine blade 24, an exhaust pressure detection portion 110 that detects the pressure of the compressed gas in the exhaust passage 70, i.e., an exhaust pressure, a target exhaust pressure setting portion 126 that sets a target exhaust pressure, and a gas supply pressure control portion (proportional valve control portion 128) that controls the pressure of the compressed gas supplied to the turbine blade 24, i.e., a gas supply pressure, the gas supply pressure control portion controlling the gas supply pressure in such a manner that the exhaust pressure detected by the exhaust pressure detection portion 110 coincides with the target exhaust pressure.

[0190] Therefore, the dental handpiece control system 2 can change the target exhaust pressure and can achieve the rotational speed (and the torque) of the turbine blade 24 (and the drill bit 30) in accordance with the situation (load, etc.).

[0191] In addition, in the dental handpiece control system 2, the target exhaust pressure setting portion 126 selects one of a plurality of target exhaust pressures stored in advance based on an operation of an operator.

[0192] Therefore, the dental handpiece control system 2 can change the target exhaust pressure based on the operation of the operator (doctor) and can achieve the torque of the turbine blade 24 (and the drill bit 30) in accordance with the situation (load, etc.).

[0193] In addition, in the dental handpiece control system 2, the target exhaust pressure setting portion 126 sets the target exhaust pressure based on a variation range of the exhaust pressure from a stable state.

[0194] Therefore, the dental handpiece control system 2 can change the target exhaust pressure automatically based on the detection result of the exhaust pressure detection portion 110 and can achieve the torque of the turbine blade 24 (and the drill bit 30) in accordance with the situation (load, etc.).

[0195] In addition, in the dental handpiece control system 2, the target exhaust pressure setting portion 126 sets the target exhaust pressure in such a manner that the target exhaust pressure is higher as the variation range is larger in a case where the exhaust pressure has decreased from the stable state.

[0196] Thus, the dental handpiece control system 2 can automatically change the target exhaust pressure in accordance with the variation amplitude of the load acting on the dental handpiece 20 in the case where the load increases, and can achieve the torque of the turbine blade 24 (and the drill bit 30) corresponding to the situation (load, etc.).

[0197] Further, in the dental handpiece control system 2, the target exhaust pressure setting section 126 sets the target exhaust pressure in such a manner that the target exhaust pressure becomes lower as the variation amplitude becomes larger in the case where the exhaust pressure has risen from the stable state.

[0198] Thus, the dental handpiece control system 2 can automatically change the target exhaust pressure in accordance with the variation amplitude of the load acting on the dental handpiece 20 in the case where the load decreases, and can achieve the torque of the turbine blade 24 (and the drill bit 30) corresponding to the situation (load, etc.).

[0199] Further, in the dental handpiece control system 2, the target exhaust pressure setting section 126 re-sets the target exhaust pressure each time the exhaust pressure is varied from the stable state.

[0200] Thus, the dental handpiece control system 2 can automatically change the target exhaust pressure a plurality of times in accordance with the change in the load acting on the dental handpiece 20 caused by the operation of the operator (doctor) in the dental treatment, and can achieve the torque of the turbine blade 24 (and the drill bit 30) corresponding to the situation (load, etc.).

[0201] Further, in the dental handpiece control system 2, the target exhaust pressure setting section 126 sets a lower limit value and an upper limit value of the target exhaust pressure, and the supply pressure control section controls the supply pressure in such a manner that the supply pressure is kept constant in the case where the exhaust pressure becomes a value between the lower limit value and the upper limit value of the target exhaust pressure.

[0202] Thus, the dental handpiece control system 2 can not change the target exhaust pressure with respect to the slight variation of the exhaust pressure, and can stabilize the rotational speed (and the torque) of the turbine blade 24 (and the drill bit 30). Further, the dental handpiece control system 2 can suppress the occurrence of overshoot, undershoot, etc. caused by the influence of the length of the exhaust flow path 70 (the distance from the dental handpiece 20 to the exhaust pressure detection section 110), etc.

[0203] Further, the dental handpiece control system 2 is provided with a proportional valve 90 provided on the supply flow path 60, and the supply pressure control section controls the opening degree of the proportional valve 90.

[0204] Therefore, the dental handpiece control system 2 can steplessly adjust the exhaust pressure so as to appropriately match the target exhaust pressure, by controlling the opening degree of the proportional valve 90 on the supply air flow path 60 based on the exhaust pressure.

[0205] The above describes an embodiment of the present application, but the present application is not limited to the above-described embodiment and can be appropriately changed within a range not departing from the gist of the present application. For example, the kind and normality determination database 121a can also be divided into a kind determination database for determining the kind of the dental handpiece 20 and a normality determination database for determining whether the dental handpiece 20 is normal for each kind of the dental handpiece 20.

[0206] Explanation of Reference Signs

[0207] 1 Dental treatment unit

[0208] 2 Dental handpiece control system

[0209] 3 Chair unit

[0210] 3a Chair main body

[0211] 4 Base unit

[0212] 5 First support portion

[0213] 5a, 5b Arm portion

[0214] 6 Treatment table

[0215] 6a Table

[0216] 6b Hanger

[0217] 6c Hose

[0218] 6d Mounting portion

[0219] 6e Display portion

[0220] 6f Operation portion

[0221] 7 Second support portion

[0222] 7a, 7b Arm portion

[0223] 8 Assistant table

[0224] 8a Table

[0225] 8b Hanger

[0226] 8c Hose

[0227] 8d Mounting portion

[0228] 9 Foot control

[0229] 20 dental handpiece

[0230] 21 air supply flow path in handpiece

[0231] 22 turbine chamber

[0232] 23 air exhaust flow path in handpiece

[0233] 24 turbine blade

[0234] 30 drill bit

[0235] 40 instrument

[0236] 50 compressed gas source

[0237] 60 air supply flow path

[0238] 61 upstream side air supply flow path

[0239] 62 flow path switching section

[0240] 63 downstream side air supply flow path

[0241] 70 air exhaust flow path

[0242] 71 upstream side air exhaust flow path

[0243] 72 flow path merging section

[0244] 73 downstream side air exhaust flow path

[0245] 80 on-off valve

[0246] 90 proportional valve

[0247] 100 setting detection section

[0248] 110 exhaust pressure detection section

[0249] 120 control section

[0250] 121 storage section

[0251] 121a database for kind and normal determination

[0252] 121b database for failure determination

[0253] 121c target exhaust pressure database

[0254] 122 on-off valve control section

[0255] 123 control valve control section

[0256] 124 exhaust pressure time characteristic calculation section

[0257] 125 determination section

[0258] 126 target exhaust pressure setting section

[0259] 127 comparison section

[0260] 128 proportional valve control section (supply pressure control section)

Claims

1. A dental handpiece control system, characterized in that, have: The gas supply path supplies compressed gas from a compressed gas source to the turbine blades of the dental handpiece. An exhaust flow path that allows the compressed gas after rotating the turbine blades to be exhausted; The exhaust pressure detection unit detects the pressure of the compressed gas in the exhaust flow path, i.e., the exhaust pressure. The target exhaust pressure setting unit sets the target exhaust pressure. as well as The gas supply pressure control unit controls the pressure of the compressed gas supplied to the turbine blades, i.e., the gas supply pressure. The gas supply pressure control unit controls the gas supply pressure in such a way that the exhaust pressure detected by the exhaust pressure detection unit matches the target exhaust pressure.

2. The dental handpiece control system as described in claim 1, characterized in that, The target exhaust pressure setting unit selects one of the pre-stored target exhaust pressures based on the operator's operation.

3. The dental handpiece control system as described in claim 1, characterized in that, The target exhaust pressure setting unit sets the target exhaust pressure based on the range of change of the exhaust pressure from a stable state.

4. The dental handpiece control system as described in claim 3, characterized in that, The target exhaust pressure setting unit sets the target exhaust pressure in such a way that the greater the change, the higher the target exhaust pressure, when the exhaust pressure has decreased from the stable state.

5. The dental handpiece control system as described in claim 3, characterized in that, The target exhaust pressure setting unit sets the target exhaust pressure in such a way that the greater the change, the lower the target exhaust pressure, when the exhaust pressure has risen from the stable state.

6. The dental handpiece control system as described in any one of claims 3 to 5, characterized in that, The target exhaust pressure setting unit resets the target exhaust pressure each time the exhaust pressure changes from the stable state.

7. The dental handpiece control system as described in claim 3, characterized in that, The target exhaust pressure setting unit sets the lower limit and upper limit of the target exhaust pressure. When the exhaust pressure becomes a value between the lower limit and the upper limit of the target exhaust pressure, the gas supply pressure control unit controls the gas supply pressure in a way that keeps the gas supply pressure constant.

8. The dental handpiece control system as described in claim 1, characterized in that, The dental handpiece control system includes a proportional valve located on the air supply path. The gas supply pressure control unit controls the opening degree of the proportional valve.

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