JPS6122857A - Drive control of gypsum cutter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method for controlling the drive of a cast cutting machine.The technical background of the invention and its problems are generally treated by using a cast such as plaster to cut the affected area. Once covered and fixed, the cast must be cut and removed after the fracture has healed.

For this reason, in the past, a circular saw blade with a triangular cutting edge on the outer periphery was electrically vibrated reciprocatingly in the circumferential direction at an amplitude of 2 to 3 nwn, and when it was pressed against the cast and cut, the lower cotton bandage was removed. The hardened cast is cut by the sensation of reaching . Therefore, the operator is required to cut the cast quickly while being extremely careful to prevent the cutting blade from touching the skin, which places a heavy burden on the operator. Particular attention should be paid to areas where bones protrude close to the skin, such as the bulge. Furthermore, since the procedure is performed based on the senses of the practitioner, the patient also feels a great deal of fear.

Purpose of the Invention The present invention has been made in view of the above points, and is a system that automatically weakens or stops the vibration of the vibrating cutter when it approaches the skin, without relying on the operator's intuition. An object of the present invention is to provide a drive control method for a cast cutting machine that can ensure performance.

SUMMARY OF THE INVENTION The present invention utilizes an oscillator to reduce the capacitance between the cutting blade and the skin.
114 frequency determining element and self-sustained oscillation)
I: Use a timer 4 that operates within the time period when the oscillation frequency of + is stable, detect the change in the oscillation frequency when the cutting blade approaches the skin, and weaken or stop the vibration of the cutter; This is a 1'J product that uses a simple self-exciting oscillator to ensure skin protection.

Examples of the invention Embodiments of the present invention will be described based on the drawings.

First, the structure of the cast cutting machine 1 used in this embodiment will be explained with reference to FIG. 2 is step horn type Ail
It is a sound wave oscillator, and by an electrostrictive element or a magnetostrictive element.
q<ljl+. Here, when the vibration type f1 of the ultrasonic vibrator 2 is driven by the ultrasonic frequency (natural resonance frequency) by the power source vj, the axial direction of the ultrasonic vibrator 2 is λ/2.
(λ is the wavelength of the resonant frequency) to cause longitudinal vibration by resonant vibration. Small diameter portion 2 of such ultrasonic vibration r2
A cutter 4 having a cutting edge 3 is provided perpendicularly to the tip of a, and is integrally fastened with a bolt 5 and a washer 6.

Therefore, when cutting the cast 7, hold the ultrasonic transducer 2 in your hand, apply the cutting blade 3 to the cast 7, and rotate it slightly in the direction of arrow A, as shown in Fig. 2, in the cutting direction indicated by the arrow. Proceed to. At this time, when the ultrasonic vibrator 2 is longitudinally vibrated in the axial direction at an ultrasonic frequency, the cutter 4 provided at the tip is ultrasonically vibrated in the thickness direction orthogonal to the cutting direction. Therefore, the cast 7 on the side surface of the groove cut by the cutting blade 3 is pulverized and cut open by vibration in the thickness direction, so that the cast 7 is easily cut and the vibration noise is reduced. Here, cast 7 to be cut
is wrapped on top of the lower cotton bandage 9 wrapped on the skin 8 and solidified.

Thus, the ultrasonic transducer 2 is driven by a driver 10. Also, the self-excited oscillator 12 is connected to the cutting edge 3 of the cutter 4.
The capacitance between the tip and the skin 8 is used as the oscillation frequency determining element, and the hot lead 13 is connected to the cutter 4 and the common lead 14 is connected to the skin 8. Thereby, when the cutting blade 3 approaches the skin 8, the oscillation frequency of the self-excited oscillator 2 is set to gradually decrease due to a change in the capacitance between the two. Further, the cutter 4 and the ultrasonic vibrator 2 are electrically insulated by an insulator such as ceramic. The oscillation frequency signal SO of this oscillator]2 is input to the gate circuit 1 (i, I?) having a different time G i HG 2 by a signal line 15, and the gate circuit 16 or 11. The data counted by the second counter 19 is inputted to the counter 19 through the switch 20 and is counted.
1, the data in this memory 21 is stored in the signal line 2
2, the data of the previous dlr counter 19 is inputted to the comparator 24 through the signal line 2:4 and compared; When the output signal Sc is smaller than the data of the dry part 0 by the signal line 25
The vibrations of the ultrasonic vibrator 2 and therefore the cutter 4 are driven and controlled.

Also, the time period during which the oscillation frequency of the self-excited oscillator 12 remains stable enough to detect the amount of change to be detected (
A timer 26 is provided which operates within 2 minutes, for example. The output ST of this timer 2-6 is connected to the AN signal line 27 together with the output signal Sc from the comparator 24.
The output signal from the AND circuit 28 is input to the D circuit 28, and the output signal from the AND circuit 28 is 1) 9 input to the driver 10 described in 7j.
When the output from this A N l) circuit 28 disappears, the driver 10 is controlled to weaken or stop the vibration of the cutter 4. Further, 29 is a display device serving as a notification means for indicating whether the timer 26 is in operation.

Further, a reset circuit 31 operated by a reset switch 30 is provided connected to the changeover switch 18, switch 19, and timer 26.

Note that the gate time Gs and G2 are set such that GL<G2.

In such a configuration, operation control is performed in the following sequence. Specifically, 90% in 4Q for a certain period of time.
A clock pulse is generated, and each operation is performed in synchronization with this clock pulse.

First 1. With the glue VJJ3 of the cutter 4 attached to the tip of the I'fJ sonic vibrator 2 removed from the cast 7, press the reset switch 30 to turn the reset circuit 31 one step. The reset 1- signal from the reset circuit 31 causes the changeover switch 18 and the switch 20 to switch to the state shown by the dashed line. For this reason, the switching suit 18
selects the gate circuit 1st, and the switch 20 is in the ON state. Therefore, the oscillation frequency signal So of the oscillator 12 passes through the gate circuit W816, which is the gate time G1, to the counter 1.
9, the count value is accumulated, and when the gate circuit 16 closes, the count value is held. At the same time as this gate circuit 1 is closed, the data of the counter 19 is transferred to the memory 21 via the ON switch 20.
is sent to and stored. In other words, this stored data becomes the reference frequency data.

When the input of the reference data to the memory 21 is completed in this way, the reset circuit of the reset circuit 31 disappears, and the changeover switch 18 and the switch 20 return to the solid line state. That is, the selector switch 18 selects the gate circuit 17 having gate time G2.

Switch 20 is turned off. At the same time, timer 26 is also triggered and becomes active within its set time. In this state, the cutting blade 3 is applied to the cast 7 to cut into the cast 7. Therefore, the oscillation frequency signal So of the oscillator 12 is inputted to the counter 19 through the gate circuit I7, which is the time G2, and the count number is integrated, and when the gate circuit 17 closes, the count value is held. do. Since the switch 20 is OFF, this new count by the counter 19 is input to the comparator 24, where it is compared with the reference frequency data in the memory 21. However, in this T2 period, G1-time G2gG1 is G2 > G
1, so even if the cutting blade 3 causes slight spots on the skin 8 side, the new count by the counter 19 is larger than the reference frequency data in the memory 21, so the output signal Sc will continue to be output. Then, the cutting operation of the cast 7 is continued.

In this way, the cutting of the cast 7 progresses, and the blade edge 3 touches the skin 8.
When the oscillation frequency of the self-excited oscillator 12 decreases and the new count number by the counter 19 becomes smaller than the reference frequency data in the memory 21, the comparator 24 outputs an output signal Sc that controls the driver 10-. (For this reason, the gate times Gl and G2 of the gate circuits 16 and 17 are set so that this output condition is satisfied when the cutting blade 3 approaches the lower cotton bandage 9.) That is, when the cutting blade 3 approaches the set interval with respect to the skin 8, the new counter 1-number is set so that G2>Gl (4%) even if G2 is set wide. The oscillation frequency of the self-excited oscillator 12 increases until Sc becomes lower than the reference frequency data in the memory 21, the output signal Sc is no longer output from the comparator 24, and the gate circuit 28 closes. , the skin 8 is protected from the cutting blade 3 by weakening or stopping the ultrasonic motion of the cutting blade 3.

By the way, when the cutting blade 3 is moved slightly away from the skin 8, the drive becomes stronger again, but the switch state still remains unchanged, the gate time remains at G2, and the memory 21 also stores the reference frequency data before starting cutting for the first time. Therefore, as described above, the operation of detecting the approach between the cutting blade 3 and the skin 18 continues.

Such an operation of detecting the proximity of the cutting blade 3 to the skin 8 is continuously performed while the timer 26 is operating. That is, even if the cutting blade 3 does not approach the skin 8 to a predetermined distance while the timer 26 is operating, if the timer 26 times up and its output 8 becomes zero, the A N
Since the '1m circuit 28 is closed, the driver 10 is controlled to weaken or stop the vibration of the cutter 4. That is, when the set time of the timer 26 has elapsed, the approach detection operation is stopped and the vibration of the cutter 4 is also stopped.

By using such a timer 26, it is possible to reliably perform the approach detection operation fj while using the cylindrical self-excited oscillator 12. That is, basically, the cutting edge 3 and rJi
Fl'' is detected as a change in the oscillation frequency of the white excitation oscillation ring 12, and the approach of the cutting blade 3 to the skin 13 is detected.However, this cutting blade 3 and The capacitance between the skin 8 and the amount of change due to the detection operation is extremely small.Therefore, the rate of change in the oscillation frequency contained in the oscillator is also small, for example, 0.1 to 0.2%. Nevertheless, if the approach detection!I!I+ operation continues for a long time, the rate of change in the frequency of the self-excited oscillator 12 will exceed the detected change wind, and the approach detection of the cutting blade 3 will be interrupted. Therefore, in this embodiment,
For such a self-excited oscillator 12, a timer 2 (6) is used that operates within a time period in which the oscillation frequency is in a stable state sufficient to detect the amount of change to be detected, and the operation of this timer 26 is The above-mentioned approach detection operation is performed only inside.

By the way, when the vibration of the cutter 4 is weak or has stopped, either the cutting blade 3 has approached the skin 8 or the termer 26 has timed up.

Here, the timer 26 is displayed on the display 29 while the timer 26 is operating. Therefore, if the vibration of the cutter 4 stops while the display 29 is showing this, the practitioner can determine that the cutting blade 3 has approached the skin 8 and that the cutting of the cast 7 in that area has been completed. , can be transferred to cast amputation of different areas. On the other hand, if the display on the display 29 disappears and the vibration of the cutter 4 stops, etc., the practitioner can determine that the cast cutting has not finished but is due to the timer 26 time-up, and can restart the cutter 4. You can move on to processing. 1. On the other hand, this restart is also performed by pressing the reset switch 30 and activating the reset circuit 31 in the same way as the first time. The changeover switch 18 and the switch 20 are switched by the reset signal from the reset circuit 31, and the oscillation frequency of the self-excited oscillator 12 at that time is counted by the counter 19 and updated and reset in the memory 21 as reference data for comparison. become. After that, timer 26
When the cutter 4 is retriggered and the vibration drive of the cutter 4 is performed [), the approach detection operation of the cutting blade 3 is performed within the operating time of the timer 26. At this time, the reference data in the memory 21 is not the original data, but is updated and sorted at the oscillation frequency at this point in consideration of frequency fluctuations, so even if it is 1'1 close to the current timer operation time, The detection operation is performed reliably.

In this embodiment, the cast cutting machine 1 is used to cut the cast 7 by vibrating the cutter 4 using the ultrasonic vibrator 2 in its thickness direction in order to reduce the vibration noise and increase the cutting effect.
Although the explanation has been given on a method for cutting 5, the same method can also be applied to a conventional method in which a circular saw cutter is electrically vibrated once in the circumferential direction for cutting. Alternatively, the cutter may be vibrated back and forth in the circumferential direction by an ultrasonic vibrator.

Effects of the invention 1 As described in Lillo, J., the capacitance between the cutting edge of the cutter and the skin is used as the oscillation frequency determining element of the self-excited oscillator, and the oscillation frequency of the self-excited oscillator is stabilized. We used a timer that operates within a certain period of time, and while the timer was operating, the approach of the cutting blade was detected by changes in the oscillation frequency to control the vibration of the cutting blade, so we used a simple self-excited oscillator. However, the detection operation is performed reliably, allowing the practitioner to operate the cast cutting machine with peace of mind without damaging the skin, and the fear caused to the patient can be significantly alleviated. By notifying the user with the first stage of the alarm, the practitioner is sure to know whether the weakening or stopping of the vibration of the cutter is due to the cutting blade approaching the skin or due to the timer going up, and takes appropriate measures. By updating and resetting the base 7<1i data using the reset circuit,
While using a self-excited oscillator, it is possible to perform a stable approach detection operation every time the system is restarted.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an external perspective view, and FIG. 2 is a block diagram. 3. Cutting blade, 4. Cutter, 7. Cast, 8. Skin, 12. Self-excited oscillator, 26. Timer, 29. Display (notification means), 3 Triset 1-Circuit amount 1 + i person Taga Electric Co., Ltd. Niss P.C. Service Co., Ltd.'' Shikumax Co., Ltd. Commissioner of the Patent Office Manabu Shiga 1. Indication of the incident Japanese Patent Application No. 59-145058 2 Name of the invention Drive control method for Gibbs cutting machine 4 Agent address: 107th Amendment to Japanese Patent Application No. 59-145058 Concerning this application, the description in the specification and drawings 1 below
). Record 1, Akii Ill i! ! 'Data in r memory 21 on page 6, line 16 to line 18...
"When the data is smaller than the data" is corrected to "When the data in the memory 21 is smaller than the data in the counter 1." 2. Mingsou i! In F, on page 11, line 19, "Vibration also stops 1." is corrected to "1b (Vibration is weak or stopped.") 3. Among the drawings, correct Figure 1 as shown in the attached sheet.

Claims (1)

[Claims] 1. The capacitance between the vibrating cutter blade and the skin is used as the oscillation frequency determining element of a self-excited oscillator, and the self-excited oscillator operates within a stable oscillation frequency time. Driving a cast cutting machine characterized in that the vibration of the cutter is controlled by detecting the approach of the cutting blade to the skin by changing the oscillation frequency of the self-excited oscillator while the timer is operating. Control method. 2. Using the capacitance between the cutting blade of the vibrating cutter and the skin as the oscillation frequency determining element of the self-excited oscillator, and using a timer that operates within the time period when the oscillation frequency of the self-excited oscillator is stable, this The vibration of the cutter is controlled by detecting the approach of the cutting blade to the skin by a change in the oscillation frequency of the self-excited oscillator while the timer is operating, and the notification means is used to notify that the timer is operating. A drive control method for a cast cutting machine. 3. Using the capacitance between the cutting edge of the vibrating cutter and the skin as the oscillation frequency determining element of the self-excited oscillator, and using a timer that operates within the time period when the oscillation frequency of the self-excited oscillator is stable, this A circuit that detects the approach of the cutting blade to the skin by a change in the oscillation frequency of the self-excited oscillator during operation of the timer, controls the vibration of the cutter, and resets reference data for detecting the change in the oscillation frequency. A drive control method for a plaster cutting machine, characterized in that a timer operation is started by updating and resetting the machine.