JP6429071B2 - Dental treatment chair and driving method thereof - Google Patents

Description

  The present invention relates to a dental treatment chair and a driving method thereof, and more particularly, to a dental treatment chair and a driving method thereof that reduce the occurrence of an impact during posture adjustment of each part of the chair.

  The dental treatment chair can be adjusted in various postures such as raising and lowering the chair and raising and lowering the backrest so that the operator can easily treat the patient. When adjusting the posture of the dental treatment chair, particularly when driving and stopping, there may be a shock due to a sudden change in the adjusted part of the chair, giving the patient a sense of fear or lowering the waist. It may cause pain for patients with cervical spine disease.

  For this reason, for example, in Patent Document 1, acceleration and / or deceleration is gradually increased at the start and / or stop of a controlled movable part such as a seat seat and a back plate seat, and then gradually. It is disclosed to provide a control means for controlling the speed of movement to reach a predetermined maximum speed and / or zero, and to control the acceleration and / or deceleration of the hydraulic fluid supply line of the hydraulic mechanism. It is disclosed that it is performed by opening / closing control of a hydraulic valve disposed in the middle.

  Further, in Patent Document 2, the number of rotations of a hydraulic pump driving motor that drives a lift cylinder for a chair and a tilt cylinder for a backrest is controlled based on an acceleration / deceleration time setting input in advance to an inverter, and driving is started. It is disclosed that sometimes the motor is gradually accelerated from a low speed and the rotational speed is gradually decreased at the end of driving, and it is said that the impact caused by the rapid fluctuation of driving at the start and end of driving is eliminated.

JP 2003-325595 A JP 2008-142455 A

  In the ones described in Patent Literatures 1 and 2, basically, the amount of hydraulic oil supplied into the hydraulic cylinder is gradually increased or decreased by opening / closing control of the hydraulic valve or rotation speed control of the hydraulic pump. It reduces the occurrence of shocks at startup and stop. For this reason, in the thing of patent document 1, it is necessary to use the hydraulic valve of a special structure as a hydraulic valve, and in the thing of patent document 2, the inverter for changing the rotation speed of a hydraulic pump And its control circuit needed.

  The present invention has been made in view of these circumstances, and adjusts the posture of each part of the dental treatment chair by using a simple hydraulic circuit and devising the drive timing of the hydraulic pump and the control valve of the hydraulic circuit. It is an object of the present invention to provide a dental treatment chair and a driving method thereof that reduce the occurrence of shock at the time.

In order to solve the above problems, the invention of claim 1 is directed to a dental treatment chair that adjusts the posture of each part of a chair by a hydraulic circuit having a hydraulic cylinder, a hydraulic pump, and a control valve. An accumulator is provided between the control valve and the closing of the control valve is delayed from the stop of the hydraulic pump.

The invention of claim 2 is characterized in that, in the invention of claim 1 , the time difference between the closing of the control valve and the stop of the hydraulic pump is at least 0.1 second.

The invention of claim 3 is characterized in that, in the invention of claim 1 or 2 , the start of the hydraulic pump is delayed from the opening of the control valve.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, the accumulator is provided between the hydraulic cylinder and the control valve.

The invention of claim 6 is a method for driving a dental treatment chair in which the posture of each part of the chair is adjusted by a hydraulic circuit having a hydraulic cylinder, a hydraulic pump, a control valve, and an accumulator, wherein the control valve is closed. It is delayed from the stop of the hydraulic pump .
The invention of claim 7 is characterized in that, in the invention of claim 6 , activation of the hydraulic pump is delayed from opening of the control valve.

  According to the present invention, the rapid supply of hydraulic oil into the cylinder chamber of the hydraulic cylinder can be mitigated by the damper, and the occurrence of residual pressure in the cylinder chamber can be eliminated, so that the dental treatment can be performed with a simple hydraulic circuit configuration. It is possible to reduce the occurrence of an impact when adjusting the posture of each part of the chair.

It is a schematic block diagram for demonstrating an example of the dental treatment chair with which this invention is applied. It is a block diagram which shows an example of the hydraulic circuit of the dental treatment chair which concerns on this invention. It is a figure for demonstrating an example of operation | movement of the hydraulic circuit of the dental treatment chair which concerns on this invention. It is a figure for demonstrating the other example of operation | movement of the hydraulic circuit of the dental treatment chair which concerns on this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a dental treatment chair and a driving method thereof according to the present invention will be described with reference to the drawings. In the following description, the configurations denoted by the same reference numerals in different drawings are the same, and the description thereof may be omitted.

  FIG. 1 is a schematic configuration diagram for explaining an example of a dental treatment chair to which the present invention is applied. The dental treatment chair 1 has a base 2 and a seating portion including a contour seat 3, a backrest 4, a legrest 5 and the like provided on the base 2. The base 2 is provided with a lifting cylinder 10 between the grounding portion, and the base 2 is lifted by pulling out the piston rod 10c of the lifting cylinder 10 from the lifting cylinder 10 to lift the piston rod 10c. The base 2 is lowered by being drawn into the cylinder 10.

  The backrest 4 is provided so as to be rotatable about the shaft portion 8 with respect to the base 2, and the angle with respect to the contour seat 3 can be changed. In this embodiment, the raising / lowering cylinder 20 is fixed to the base 2, and the link 21 is provided between the shaft portion 6 on the lower side of the backrest and the shaft portion 7 provided on the piston rod 20 c of the raising / lowering cylinder 20. Is provided. The backrest 4 is laid by pulling out the piston rod 20c of the raising / lowering cylinder 20 from the raising / lowering cylinder 20, and the backrest 4 is raised by drawing the piston rod 20c into the raising / lowering cylinder 20. The raising / lowering cylinder 10 and the raising / lowering cylinder 20 correspond to the hydraulic cylinder of this invention.

  The seat 2, such as the base 2, the contour seat 3, the backrest 4, and the legrest 5, can be moved up and down or the backrest 4 can be raised and lowered by operating an operation switch (not shown). The surgeon can perform medical treatment by moving each part of the dental treatment chair 1 up and down to bring the patient into an easy-to-treat posture. In the present embodiment, the vertical movement of the seating portion on which the weight of the patient is mainly applied and the backrest 4 being tilted will be described as the adjustment part of the dental treatment chair 1, but other parts of the dental treatment chair, for example, An anvil or a footrest may be provided so that the posture can be adjusted.

  FIG. 2 is a block diagram showing an example of a hydraulic circuit of the dental treatment chair according to the present invention. The hydraulic circuit 100 is for driving the elevating cylinder 10 and the raising / lowering cylinder 20, and includes a controller 30, a hydraulic pump 40, a drive motor 41, an oil tank 42, control valves 51 to 56, and accumulators 61 to 63. It has. The controller 30 is for starting and stopping the hydraulic pump 40 by the drive motor 41 and opening / closing the control valves 51 to 56 in accordance with an operation of an operator from an operation panel (not shown).

  In this embodiment, the elevating cylinder 10 is configured as a single-acting cylinder, and a piston 10b is provided in the cylinder tube 10a, and a piston rod 10c is provided on the piston 10b. The cylinder tube 10a is raised by pulling out the piston rod 10c from the cylinder tube 10a by supplying hydraulic oil to the cylinder chamber 10d formed by the cylinder tube 10a and the piston 10b. On the other hand, the lowering of the cylinder tube 10a is performed by discharging hydraulic oil from the cylinder chamber 10d.

  The raising / lowering cylinder 20 is configured as a double acting cylinder, and a piston 20b is provided in the cylinder tube 20a, and a piston rod 20c is provided on the piston 20b. The raising / lowering cylinder 20 draws the piston rod 20c from the cylinder tube 20a by supplying the hydraulic oil to the cylinder chamber 20d formed by the cylinder tube 20a and the piston 20b and discharging the hydraulic oil from the cylinder chamber 20e on the piston rod side. The piston rod 20c is drawn from the cylinder tube 20a by supplying the hydraulic oil to the cylinder chamber 20e and discharging the hydraulic oil from the cylinder chamber 20d.

  The hydraulic circuit 100 includes a hydraulic pump 40 and an oil tank 42. The hydraulic pump 40 is driven by a drive motor 41 and supplies hydraulic oil from an oil tank 42 to the lifting cylinder 10 and the raising cylinder 20. The amount of hydraulic oil discharged from the hydraulic pump 40 can be changed by changing the rotational speed of the drive motor 41. The hydraulic pump 40 and the drive motor 41 may be constituted by an electric pump in which these are integrated. The oil tank 42 stores the hydraulic oil discharged from the elevating cylinder 10 and the raising / lowering cylinder 20 and supplies it again to the hydraulic pump.

  Control valves 51 to 56 are provided between the hydraulic pump 40 and the raising / lowering cylinder 10 and the raising / lowering cylinder 20. In this embodiment, the control valves 51 to 56 are two-port single-acting normally closed solenoid valves, which are in a closed state when not energized and open when energized. The control valve is not limited to a 2-port single-acting normally closed solenoid valve, and other control valves may be used, such as a 2-port single-acting normally-open solenoid valve. The control valve 51 is a control valve for supplying hydraulic oil from the hydraulic pump 40 to the cylinder chamber 10d of the lifting cylinder 10, and the control valve 52 discharges the hydraulic oil from the cylinder chamber 10d of the lifting cylinder 10 to the oil tank. This is a control valve.

  The control valve 51 and the control valve 52 are not simultaneously opened, and both the control valve 51 and the control valve 52 are maintained in the closed state when the position of the seating portion is maintained. When raising the seat, the control valve 51 is opened and the control valve 52 is closed, so that hydraulic oil can be supplied to the cylinder chamber 10d and the cylinder tube 10a is raised. . When lowering the seating portion, the control valve 51 is closed and the control valve 52 is opened, so that the weight of the patient and the seating portion causes the weight to act from the cylinder chamber 10d via the control valve 52. Oil is discharged into the oil tank.

  The control valve 53 is a control valve for supplying hydraulic oil from the hydraulic pump 40 to the cylinder chamber 20 e of the raising / lowering cylinder 20, and the control valve 54 supplies hydraulic oil from the cylinder chamber 20 e of the raising / lowering cylinder 20. It is a control valve for discharging to the oil tank. Further, the control valve 55 is a control valve for supplying hydraulic oil from the hydraulic pump 40 to the cylinder chamber 20 d of the raising / lowering cylinder 20, and the control valve 56 supplies hydraulic oil from the cylinder chamber 20 d of the raising / lowering cylinder 20. It is a control valve for discharging to the oil tank.

  The control valve 53 and the control valve 54, and the control valve 55 and the control valve 56 are not simultaneously opened, and when the posture of the backrest 4 is maintained, all of the control valves 53 to 56 are used. The valve is kept closed. When raising the backrest 4, by opening the control valve 53 and the control valve 56, the hydraulic oil is supplied to the cylinder chamber 20e and the hydraulic oil is discharged from the cylinder chamber 20d. The piston 20b is moved in the retracting direction. During this time, the control valves 54 and 55 are kept closed.

  When tilting the backrest 4, the control valve 55 and the control valve 54 are opened to supply the hydraulic oil to the cylinder chamber 20d and discharge the hydraulic oil from the cylinder chamber 20e. The piston 20b is moved in the direction to pull out 20c. During this time, the control valves 53 and 56 are kept closed. When the posture adjustment of the dental treatment chair 1 is not performed, that is, when the position of the seating portion is not moved, the control valves 51 to 56 are closed, and the hydraulic pump 40 is not driven.

  In the present invention, the cylinder chamber of the lift cylinder 10 and the control valve 51 are used to alleviate the impact of the chair operation at the start and stop in various posture adjustments, such as the chair lift and backrest tilting operations. , 52 between the cylinder chamber 20e of the raising / lowering cylinder 20 and the control valves 53, 54, an accumulator 62 between the cylinder chamber 20d of the raising / lowering cylinder 20 and the control valves 55, 56. An accumulator 63 is arranged between each.

  The accumulator 61 of this embodiment is a piston type accumulator, and includes a cylinder tube 61a, a piston 61b, and a spring 61c. The piston 61b is fixed to the cylinder tube 61a via a spring 61c, and is provided so as to be movable in the cylinder tube 61a in a state where a spring load is applied. The cylinder chamber 61d formed by the cylinder tube 61a and the piston 61b is provided with a hydraulic oil input / output port. This input / output port may be a common port.

  If the control valve is rapidly closed or a sudden load change occurs, impact pressure is generated in the piping of the hydraulic circuit, which may cause noise or damage to the piping equipment. However, the hydraulic oil in the cylinder chamber 61d of the accumulator 61 is used. Therefore, the impact can be reduced by opening and closing the control valves 51 and 52. In addition, the hydraulic oil discharged from the hydraulic pump contains pulsation due to the structure of the pump, which causes noise and vibration, which makes the hydraulic circuit operation unstable and causes equipment damage. The accumulator 61 can attenuate the pulsation of the hydraulic oil. The configuration of the accumulators 62 and 63 is the same as that of the accumulator 61, and the operation and effect thereof are also the same.

  In the hydraulic circuit 100, when the hydraulic pump is started or stopped and the control valve is opened and closed at the same time, the valve is suddenly opened and closed when the hydraulic oil pressure in the hydraulic circuit is high. Occur. This impact can be mitigated by the accumulator described above, but in the present invention, the impact is further mitigated by providing a time difference between the start or stop of the hydraulic pump and the opening and closing of the control valve.

  In the case of a double acting cylinder, if the hydraulic pump is stopped and the control valve is closed at the same time, pressure from the hydraulic pump remains in the cylinder chamber on the hydraulic oil supply side. For this reason, the pressure in the cylinder chamber increases, and when the dental treatment chair 1 is driven again and the control valve is opened, the residual pressure in the cylinder chamber is released and a large amount of hydraulic oil is discharged from the cylinder chamber at once. It will be oiled and an impact will occur when the dental treatment chair is re-driven. Therefore, in the case of a double-acting cylinder, it is desirable to close the control valve without applying pressure from the hydraulic pump to the hydraulic cylinder, so that there is a time difference between starting or stopping the hydraulic pump and opening / closing the control valve. Thus, the occurrence of residual pressure in the cylinder chamber can also be prevented.

  FIG. 3 is a diagram for explaining an example of the operation of the hydraulic circuit of the dental treatment chair according to the present invention, and shows the operation timing of each part when raising the seating part. When the surgeon operates an operation switch (not shown) and performs an operation of raising the seating portion between time t0 and time t2, the controller 30 receives an operation signal from the operation switch, and at time t0, the control valve 51 Next, the hydraulic pump 40 is driven at time t1 slightly later than time t0. For this reason, the seating portion starts to rise from time t1, which is slightly delayed from time t0. The controller 30 stops the operation of the hydraulic pump 40 at time t2 when the operation signal from the operation switch disappears, and then closes the control valve 51 at time t3.

  Since the hydraulic pump 40 is not activated at time t0, the pressure in the piping of the hydraulic circuit from the hydraulic pump 40 to the control valve 51 does not increase. When the hydraulic pump 40 is activated at time t1, the hydraulic oil Is smoothly supplied to the cylinder chamber 10 d of the lifting cylinder 10 via the control valve 51 and the accumulator 61. Since the hydraulic pump 40 stops operating at time t2, the pressure in the piping of the hydraulic circuit from the hydraulic pump 40 to the control valve 51 does not increase at time t3, and the control valve 51 is turned off at time t3. By closing the valve, it is possible to prevent an impact pressure from being generated in the piping of the hydraulic circuit.

  FIG. 4 is a view for explaining another example of the operation of the hydraulic circuit of the dental treatment chair according to the present invention, and shows the operation timing of each part when raising the backrest. When the operator operates an operation switch (not shown) to raise the backrest 4 from time t0 to time t2, the controller 30 receives the operation signal from the operation switch and receives the operation signal from the operation switch 53 at time t0. , 56 are opened, and then the hydraulic pump 40 is driven slightly later than time t0. The controller 30 stops the operation of the hydraulic pump 40 at time t2 when the operation signal from the operation switch disappears, and then closes the control valves 53 and 56 at time t3. The control valves 54 and 55 are kept closed.

  In the case of FIG. 4 as well, as in the case of FIG. 3, the hydraulic pump 40 is not started at time t0, so the pressure in the piping of the hydraulic circuit from the hydraulic pump 40 to the control valve 53 does not increase. When the hydraulic pump 40 is activated at t1, the hydraulic oil is smoothly supplied to the cylinder chamber 20e of the raising / lowering cylinder 20 via the control valve 53 and the accumulator 62. Further, the hydraulic oil is discharged from the cylinder chamber 20e through the accumulator 63 and the control valve 56. At the time of stop, since the hydraulic pump 40 stops operating at time t2, the pressure in the piping of the hydraulic circuit from the hydraulic pump 40 to the control valve 53 does not increase at time t3, and the control valve 53 is turned off at time t3. By closing the valve, it is possible to prevent generation of impact pressure in the piping of the hydraulic circuit and generation of residual pressure in the cylinder chamber.

  Thus, in this embodiment, since the hydraulic pump 40 is not operated when the control valves 51 to 56 are opened and closed, the pressure fluctuation due to the opening and closing of the control valves 51 to 56 is reduced, and the impact pressure on the piping of the hydraulic circuit is reduced. Residual pressure in the cylinder chamber can be reduced. The time difference between the time t0 when the control valve is opened and the start time t1 of the hydraulic pump need only be greater than zero seconds, and the time difference between the time t2 when the control valve is closed and the hydraulic pump time t3 is that the residual pressure is reduced. It only needs to be longer than about 0.1 seconds. The accumulator may be disposed directly under the hydraulic pump 40, but is preferably provided between the control valve and the cylinder chamber in order to alleviate pressure fluctuations in the cylinder chamber. In the present embodiment, the lifting cylinder 10 is a single-action cylinder, but may be a double-action cylinder.

DESCRIPTION OF SYMBOLS 1 ... Dental treatment chair, 2 ... Base, 3 ... Contour seat, 4 ... Backrest, 5 ... Legrest, 10 ... Lifting cylinder, 20 ... Lifting cylinder, 10a, 20a ... Cylinder tube, 10b, 20b ... Piston, 10c, 20c ... Piston rod, 10d, 20d, 20e ... Cylinder chamber, 21 ... Link, 30 ... Controller, 40 ... Hydraulic pump, 41 ... Drive motor, 42 ... Oil tank, 51-56 ... Control valve, 61 , 62, 63 ... accumulator, 61a, 62a, 63a ... cylinder tube, 61b, 62b, 63b ... piston, 61c, 62c, 63c ... spring, 61d, 62d, 63d ... cylinder chamber, 100 ... hydraulic circuit.

Claims (6)

In a dental treatment chair that adjusts the posture of each part of a chair by a hydraulic circuit having a hydraulic cylinder, a hydraulic pump, and a control valve, an accumulator is provided between the hydraulic cylinder and the control valve, and the control valve is closed. A dental treatment chair characterized by being delayed from the stop of the hydraulic pump.   The dental treatment chair according to claim 1, wherein the time difference between the closing of the control valve and the stop of the hydraulic pump is at least 0.1 second.   The dental treatment chair according to claim 1 or 2, wherein the start of the hydraulic pump is delayed from the opening of the control valve.   The said hydraulic cylinder is a hydraulic cylinder for raising / lowering the contour seat of the said dental treatment chair, or a hydraulic cylinder for raising / lowering a backrest, The one of Claim 1 to 3 characterized by the above-mentioned. Dental treatment chair. A method for driving a dental treatment chair that adjusts the posture of each part of a chair by a hydraulic circuit having a hydraulic cylinder, a hydraulic pump, a control valve, and an accumulator provided between the hydraulic cylinder and the control valve , A method for driving a dental treatment chair, characterized in that the closing of the control valve is delayed from the stop of the hydraulic pump. 6. The method for driving a dental treatment chair according to claim 5 , wherein the start of the hydraulic pump is delayed from the opening of the control valve.

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