JP2006341203A - Electromagnetic drip apparatus and vibration drip method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic drip apparatus capable of dripping a droplet having a uniform particle size into an ammonia aqueous solution and a vibration drip method. <P>SOLUTION: The electromagnetic drip apparatus includes a drip nozzle for dripping the droplet, a vibrator for providing the drip nozzle with vibration and cooling means for cooling the inside of the vibrator. Further, the vibration drip method is employed to drip the droplet from a vibrating drip nozzle with the vibrator maintained at a fixed temperature by the cooling means. Furthermore, the vibration drip method comprises providing the drip nozzle for dripping the droplet with the vibration by the vibrator, measuring the amplitude of the vibration in the drip nozzle, outputting data on a measured amplitude, inputting the outputted data and outputting a control signal to the vibrator such that the vibrator controls a fixed vibration. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electromagnetic dropping device and a vibration dropping method, and more particularly to an electromagnetic dropping device and a vibration dropping method used in, for example, an ammonium heavy uranate particle manufacturing apparatus.

  A fuel for a HTGR is generally manufactured through the following processes. First, uranium oxide powder is dissolved in nitric acid to obtain a uranyl nitrate stock solution containing uranyl nitrate. Next, pure water, a thickener, etc. are added to this uranyl nitrate stock solution and stirred to prepare a dripping stock solution containing uranyl nitrate. The prepared dropping undiluted solution is cooled to a predetermined temperature to adjust the viscosity, and then dropped into an aqueous ammonia solution using a small-diameter dropping nozzle.

  The droplets dropped onto the aqueous ammonia solution are sprayed with ammonia gas before reaching the surface of the aqueous ammonia solution. The surface of the droplet is gelled by the ammonia gas, thereby preventing deformation when reaching the surface of the aqueous ammonia solution. Uranyl nitrate in the aqueous ammonia solution reacts with ammonia to form ammonium heavy uranate particles (hereinafter sometimes abbreviated as “ADU particles”).

  The ADU particles are dried and then roasted in the air to become uranium trioxide particles. Further, the uranium trioxide particles are reduced and sintered to become high-density ceramic uranium dioxide particles. The uranium dioxide particles are screened, that is, classified to obtain fuel core fine particles having a predetermined particle size (see Non-Patent Document 1).

  In the conventional apparatus for producing ammonium heavy uranate particles, the dropping nozzle was vibrated using a vibrator, and the dropping stock solution was dropped into the ammonia water. This vibrator is provided with a coil therein, and a current is passed through the coil to obtain power. Therefore, if the vibrator is moved for a long time, the coil generates heat. Due to this heat generation, there is a problem that the vibration capability of the vibrator is lowered, and as a result, the amplitude of the dropping nozzle is reduced. Thus, when the amplitude of the dropping nozzle decreases, the volume of the droplet dropped from the dropping nozzle changes.

  In addition, when the amplitude is weakened, the droplets cannot be sufficiently separated from each other, and several droplets are united, and when the amplitude is weakened, the droplets are not separated and are not separated at the nozzle tip. There is an influence such as that the grown droplet falls due to the balance between surface tension and gravity.

  Furthermore, since the conventional vibrator is attached to the dropping nozzle disposed above the liquid surface of the aqueous ammonia solution, it is made of ammonia gas rising from the aqueous ammonia solution. Therefore, various parts forming the vibrator are corroded within a long period of time. As the various parts of the vibrator are corroded, the volume of the droplet falling from the dropping nozzle differs from the intended volume, and the droplet does not fall smoothly. As a result, there is a problem that the particle size of the droplets is not uniform. There is a problem that the particle size of the ammonium heavy uranate particles produced by the conventional ammonium heavy uranate particle production apparatus becomes uneven, and high quality ADU particles cannot be obtained.

Hasegawa Masayoshi, Mishima Yoshimi supervision "Reactor Material Handbook", published on October 31, 1977, pages 221-247, Nikkan Kogyo Shimbun

  In order to solve the above problems, an object of the present invention is to provide an electromagnetic dropping device and a vibration dropping method capable of dropping a droplet having a uniform particle diameter into an aqueous ammonia solution.

As means for solving the problems,
An electromagnetic dropping comprising: a dropping nozzle for dropping a droplet; a vibrator for applying vibration to the dropping nozzle; and a cooling means for cooling the inside of the vibrator. Device,
According to a second aspect of the present invention, the cooling means is measured by a temperature measuring means for measuring the temperature inside the vibrator, a cooling medium supply means for cooling the inside of the vibrator with a cooling medium, and the temperature measuring means. 2. The electromagnetic dropping device according to claim 1, further comprising cooling control means for inputting data relating to the temperature and outputting a control signal for controlling the cooling medium supply means.
Claim 3 is the electromagnetic dropping device according to claim 2, wherein the cooling medium is a non-corrosive gas.
Claim 4 is a vibration dropping method characterized in that a droplet is dropped from a dropping nozzle that is vibrated by a vibrator maintained at a constant temperature by a cooling means,
According to a fifth aspect of the present invention, vibration is applied to a dropping nozzle for dropping a droplet by a vibrator, an amplitude of vibration at the dropping nozzle is measured, data on the measured amplitude is output, and the output data is The vibration dropping method is characterized by inputting and outputting a control signal to the vibrator so that the vibrator controls a certain vibration.

  According to the present invention, since the heat generated inside the vibrator can be taken away by the cooling means, the function of the vibrator is not deteriorated even when operated for a long time, and high-speed vibration is performed with a constant amplitude. be able to. An amplitude measuring device that measures the amplitude of the dropping nozzle and monitors the operating state of the vibrator, and a vibrator control means that outputs a control signal based on data output from the amplitude measuring device to the vibrator Accordingly, it is possible to drop droplets having a constant particle diameter while maintaining the amplitude of the dropping nozzle constant.

  Further, the cooling means comprises a temperature measuring means, a cooling medium supply means, and a cooling control means, so that the vibration exciter can be adjusted to a predetermined temperature. Can be kept constant. Therefore, droplets having a desired diameter can be generated, and as a result, ammonium deuterated uranate particles having a certain diameter can be produced.

  Moreover, when a non-corrosive gas is employed as a cooling medium used for the cooling means, the inside of the vibrator can be filled with the non-corrosive gas, and the vibrator is cooled with the non-corrosive gas, The inside of the vibrator is prevented from being corroded by ammonia gas. Since cooling and corrosion prevention within the vibrator with such a non-corrosive gas are achieved, the intended performance of the vibrator can be maintained over a long period of time by using the electromagnetic dropping device of the present invention, It is possible to produce ammonium deuterated uranate particles having a constant diameter over a long period of time.

  Hereinafter, an electromagnetic dropping device according to the present invention will be described with reference to the drawings.

  FIG. 1 shows an ADU particle production apparatus provided with an electromagnetic dropping device according to the present invention, and FIG. 2 shows a schematic diagram of the electromagnetic dropping device according to the present invention. In addition, the electromagnetic dripping apparatus which concerns on this invention is not restricted to the electromagnetic dripping apparatus shown by FIG.

  As shown in FIG. 1, the ammonium heavy uranate particle production apparatus 1 includes an electromagnetic dripping device 2, a dripping stock solution storage tank 9, and a reaction tank 10.

  As shown in FIG. 2, the electromagnetic dropping device 2 includes a dropping nozzle 3, a vibration exciter 4, and a cooling means 15.

  As shown in FIGS. 1 and 2, the dropping nozzle 3 drops a predetermined volume of dropping stock solution into an aqueous ammonia solution stored in the reaction vessel 10 through an opening at one end thereof (hereinafter referred to as dropped dripping). The stock solution may be referred to as a droplet.) A nozzle. As long as the dripping nozzle 3 is formed of a corrosion-resistant material, the material is not particularly limited, and can be formed of, for example, stainless steel, aluminum, an aluminum alloy, a titanium alloy, or the like.

  The shape of the horizontal section at the opening of the dropping nozzle 3 is preferably a circle having an inner diameter of 500 to 1000 μm.

  The number of the dropping nozzles 3 provided in the electromagnetic dropping device 2 may be either singular or plural. When there are a plurality of the dropping nozzles 3, they may be arranged in a horizontal row, but each of the dropping nozzles 3 has an arrangement relationship in which each dropping nozzle 3 is erected at each vertex of a square virtually formed on a plane. May be.

  As shown in FIG. 1, the other end opening of the dropping nozzle 3 is connected to a dropping stock solution supply path 5. The dripping stock solution supply path 5 is connected to the dripping stock solution storage tank 9 for storing the dripping stock solution, and the dripping stock solution in the dripping stock solution storage tank 9 is supplied by the appropriate feeding means, for example, the feeding pump 8. The liquid is sent to the dropping nozzle 3 through the path 5.

  Specifically, as shown in FIG. 1, the dripping stock solution storage tank 9 is connected to a separator 7. A liquid feed pump 8 is connected between the dripping stock solution storage tank 9 and the separator 7. The separator 7 is connected to the flow meter 6. The dripping stock solution supply path 5 is connected to a flow meter 6. The separator 7 supplies the dripping stock solution fed from the dripping stock solution storage tank 9 separately to each flow meter 6. When the dropping stock solution is fed from the dripping stock solution storage tank 9, the feeding pump 8 is operated so that the dropping stock solution is supplied from the dropping stock solution storage tank 9 through the feeding pump 8 to the separator 7. The dripping stock solution supplied to the separator 7 is supplied separately to each flow meter 6 by the separator 7.

  The dripping stock solution contains uranyl nitrate, pure water, a thickener, and the like. Examples of the thickener include polyvinyl alcohol, a resin that solidifies under alkaline conditions, polyethylene glycol, and metroses. The dripping stock solution is cooled and maintained at a predetermined temperature and the viscosity is adjusted, and then sent to the dripping nozzle 3.

  As shown in FIG. 2, the vibration exciter 4 is configured to be able to apply vibration in the vertical direction to each of the dropping nozzles 3 via the support member 11.

  Specifically, as shown in FIG. 3, the vibration exciter 4 includes the support member 11 (see FIG. 2), a coil 12, and a magnet 13.

  The magnet 13 is provided so as to be able to reciprocate within the coil 12 and is connected to the support member 11. Although not shown, the magnet 13 is provided with a biasing member such as a spring at one end or both ends of the magnet 13. The magnet 13 is displaced by the change of the magnetic field generated in the coil 12, and after this displacement, the urging force acts in the direction opposite to the displaced direction by the action of the urging member (not shown). As a result, the magnet 13 can reciprocate within the coil 12.

  On the other hand, the coil 12 is connected to an AC power source 14 connected to a pulse generator provided outside the vibration exciter 4. For example, a rectangular wave generated from the AC power source 14 to the coil 12 by the pulse generator is used. Energize the alternating current. As a result, the magnet 13 and the support member 11 can reciprocate in the vertical direction.

  As a frequency which this vibrator 4 gives to the dripping nozzle 3, 40-200 Hz is preferable. If the frequency is out of the above range, a good droplet having a predetermined outer diameter cannot be dropped from the one end opening of the dropping nozzle 3, but it is more easily determined that the frequency is in the above range. Droplets with good outer diameter can be dropped.

  There are no particular restrictions on the material, shape, and size of the conductors that form the support member 11, the coil 12, and the magnet 13, as long as the problems of the present invention are solved.

  The cooling means 15 has a function of cooling the coil 12. In the electromagnetic dripping device 2 according to the present invention, the cooling means 15 is provided to cool the heat generated in the coil 12, thereby suppressing a decrease in the vibration capability of the vibrator 4 due to heat generation.

  A preferred embodiment of the cooling means 15 includes a cooling means comprising a temperature measuring means, a cooling medium supply means, and a cooling control means. FIG. 3 shows an example of the cooling means 15.

  The cooling unit 15 in FIG. 3 includes a temperature measuring unit 16, a cooling control unit 17, and a cooling medium supply unit 18, and cools the heat generating coil 12.

  In the present invention, by providing the cooling means 15, excessive heating of the coil 12 caused by energization for a long time is suppressed, deterioration of the vibration capability of the vibrator due to heat generation of the coil 12 is prevented, and vibration of the dropping nozzle 3 is prevented. The amplitude can be kept constant. As a result, droplets having a constant particle size can be dropped into the ammonia water.

  The temperature measuring unit 16 measures the temperature of the coil 12 and transmits temperature data obtained by the measurement to the cooling control unit 17. Although there is no restriction | limiting in particular as the said temperature measurement means 16, For example, temperature sensors, such as a pressure type, a bimetal, a thermocouple, or a thermistor, can be mentioned. As shown in FIG. 3, the temperature sensor 19 may be provided either inside or outside the coil 12. In addition, the number of temperature sensors 19 to be arranged may be one or plural, but may be plural if the temperature control is performed over the entire coil 12.

  The cooling control unit 17 receives a detection signal from the temperature sensor 19 and transmits a control signal obtained by calculating the detection signal to the cooling control unit 17.

  The cooling control unit 17 transmits a control signal to the cooling medium supply unit 18 in one of the following ways, for example.

  (1) When a preset temperature is input to the cooling control means 17 in advance and it is determined from the detection signal received from the temperature sensor 19 that the temperature measured by the temperature sensor 19 is equal to or higher than the preset temperature, the control signal Is transmitted to the cooling medium supply means 18.

  (2) When a plurality of temperature sensors 19 are arranged, when it is determined by the detection signal received by the cooling control means 17 that the temperature measured in any of the plurality of temperature sensors 19 is equal to or higher than the set temperature. The control signal is transmitted to the cooling medium supply means 18.

  (3) When a plurality of temperature sensors 19 are arranged, an average value of the temperatures measured by the plurality of temperature sensors 19 is calculated from the detection signal received by the cooling control means 17, and the average value is equal to or higher than the set temperature. If it is determined that, the control signal is transmitted to the cooling medium supply means 18.

  The cooling medium supply means 18, for example, the cooling medium supply means 18 including the heat absorber 20, the radiator 21, the pipe 22 and the circulation pump 23, as shown in FIG. That is, the circulation pump 23 is operated by the control signal from the cooling control means 17, and the cooling medium circulates in the heat absorber 20 and the radiator 21 connected to the pipe 22.

  The cooling medium flowing inside the heat absorber 20 absorbs heat generated in the coil 12 and prevents the coil 12 from rising in temperature. A known heat absorber can be used as the heat absorber 20.

  The shape of the heat absorber 20 is not particularly limited, and examples thereof include a cylindrical shape or a flat plate shape. If the shape of the heat absorber 20 is cylindrical, it is provided so as to surround the coil 12 as shown in FIG. On the other hand, if the heat absorber 20 has a flat plate shape, it can be provided so as to face the cooling medium supply means for supplying the cooling medium toward the coil 12 with the coil 12 interposed therebetween, and the coil 12 can generate heat. The heat absorber 20 can be formed by the cooling medium receiving means for receiving the absorbed cooling medium.

  There is no restriction | limiting in particular as the said piping 22 and the heat radiator 21, A well-known thing is used.

  The cooling medium may be a medium having high endothermic properties and heat dissipation properties. Examples thereof include liquids such as tap water, purified water, and heavy water, and gases such as air, nitrogen gas, and carbon dioxide.

  The electromagnetic dropping device described above operates as follows.

  A threshold value is input to the cooling control means 17. The temperature measuring means 16 disposed in the vicinity of the coil 12 transmits temperature data to the cooling control means 17. The cooling control means 17 performs arithmetic processing on the received data. When the value obtained by the arithmetic processing exceeds the threshold value, a control signal is transmitted to the circulation pump 23. When the circulation pump 23 is activated, the cooling medium starts to circulate in the cooling medium supply means 18. The cooling medium introduced into the heat absorber 20 is heated by absorbing the heat of the coil 12, and then introduced into the radiator 21 through the pipe 22. Within the radiator 21, heat is dissipated from the cooling medium heated in the heat absorber 20. The cooling medium that dissipates heat and is cooled is reintroduced into the heat absorber 20 through the pipe 22. This process is repeated.

  Another example of the electromagnetic dropping device according to the present invention is shown in FIG. The electromagnetic dripping device shown in FIG. 4 differs from the electromagnetic dripping device shown in FIG. 3 in the cooling means.

  As shown in FIG. 4, the cooling means 15 </ b> A included in the electromagnetic dripping device includes a casing 29 containing the coil 12 and the magnet 13, and a temperature measurement that measures the temperature of the coil 12 disposed inside the casing 29. Means 16, a cooling control means 17 for inputting a signal outputted from the temperature measuring means 16, and a cooling medium supply means 18A.

  The cooling medium supply means 18A includes a blower pump 30 that sucks and sends air from the outside, a heat pump 31 that cools the air blown from the blower pump 30 to cool air, and is sent from the heat pump 31. A blower 32 having a jet port for sending low-temperature air toward the coil 12, a blower path 33 </ b> A for sending air from the blower pump 30 to the heat pump 31, and air from the heat pump 31 to the blower 32. A sending air passage 33B.

  The temperature measuring unit 16 includes a temperature sensor 19 that measures the temperature of the coil 12 and outputs the measured value to the cooling control unit 17.

  In this electromagnetic dropping device, the cooling means 15A can be operated as follows to drop droplets having a constant particle diameter. In the cooling means 15A, the blower pump 30 is driven to take in air from the outside, and the air is sent to the heat pump 31 through the blower passage 33A. The heat pump 31 sends air, which is cooled and maintained at a predetermined temperature, to the blower 32 through the blower passage 33B. Air cooled from the outlet of the blower 32 is sprayed onto the coil 12. Since the cooled air is sprayed onto the heated coil 12, the coil 12 is cooled.

  For example, when the coil 12 is overheated, the temperature sensor 19 detects the temperature of the coil 12 and outputs a signal related to the temperature of the coil 12 to the cooling control means 17. The cooling control means 17 compares the set temperature stored in the internal memory with the detected temperature, and inputs a control signal to each of the blower pump 30 and the heat pump 31, so that the instructed air blow amount is supplied to the heat pump 31. Deliver air.

  The heat pump 31 cools the air to the temperature set by the cooling control means 17 and sends out the cooled air to the blower 32. The blower 32 ejects the cooled air to the coil 12 to cool the coil 12. The temperature sensor 19 detects the temperature of the coil 12 cooled by the cooled air, and outputs a signal related to the temperature of the coil 12 to the cooling control means 17. When the cooling control unit 17 compares the set temperature stored in the internal memory with the detected temperature and determines that the comparison value is within the threshold value range, the cooling control unit 17 controls each of the blower pump 30 and the heat pump 31. Output a signal.

  The blower pump 30 to which the control signal is output returns to the normal operation, that is, the operation mode in which the air is blown at the normal flow rate, or stops the operation. The heat pump 31 stops cooling the air sent from the blower pump 30 in accordance with the control signal output from the cooling control means 17 or cools the air to such an extent that the temperature of the coil 12 is maintained at a predetermined temperature. To do. Air blown from the heat pump 31 is blown from the blower 32 to the coil 12.

  The air blown from the blower 32 toward the coil 12 may be intermittently blown from the blower 32 by intermittently operating the blower pump 30. It is preferable that air is continuously ejected from the blower 32 by continuously operating the blower pump 30 so as to be greater than the atmospheric pressure outside the body 29.

  Since the coil 12 is not overheated by the blowing of air, the liquid droplets dropped from the dropping nozzle 3 due to overheating of the coil 12 are not uneven.

  When the internal pressure of the housing 29 is kept in an overpressure state by continuous operation of the blower pump 30, ammonia gas rising from the aqueous ammonia solution disposed below the dropping nozzle 3 is inside the housing 29. Intrusion is prevented. Since ammonia gas does not enter the casing 29, the corrosion of the coil 12 is prevented and the life of the cooling means 15A itself is extended.

  In the electromagnetic dripping apparatus shown in FIG. 4, air is employed as an example of a non-corrosive gas. The non-corrosive gas is not limited to air, and may be any gas that does not corrode the coil 12 and the devices attached to the coil 12, and may be nitrogen gas, carbon dioxide gas, rare gas, or the like.

  When air is employed as the non-corrosive gas, the air introduced into the housing 29 may leak out of the housing 29 and diffuse into the atmosphere. When these are used, these gases are expensive, and it is preferable from the viewpoint of economy to collect and reuse the gas introduced into the housing 29.

  Another example of the electromagnetic dropping device according to the present invention is shown in FIG. In addition, the electromagnetic dripping apparatus which concerns on this invention is not limited to the electromagnetic dripping apparatus shown by FIG. The electromagnetic dripping apparatus shown in FIG. 5 includes a dripping nozzle 3, a vibration exciter 4, an amplitude measuring device 24, a vibration exciter control means 25, and a cooling means (not shown). The dripping nozzle 3, the vibrator 4 and the cooling means (not shown) are as described above.

  The amplitude measuring device 24 is provided on the outer surface of the dropping nozzle 3 and measures the acceleration of the dropping nozzle 3. An electric signal based on the measured acceleration is transmitted to the vibration exciter control means 25.

  Examples of the amplitude measuring device 24 include an accelerometer, a speedometer, and a displacement meter, and an accelerometer is particularly preferable. Further, the amplitude measuring device 24 has a vibration pickup inside thereof. Examples of the vibration pickup include a piezoelectric pickup, an electrodynamic pickup, a strain gauge pickup, a piezoresistive pickup, and a servo pickup. In the present invention, it is preferable to use an amplitude measuring device having a piezoelectric pickup. Since the piezoelectric pickup is small and lightweight, it does not apply a load to the vibrator 4 even if it is attached to the dropping nozzle. Other actions and effects are as described above.

  The vibration exciter control means 25 receives a signal output from the amplitude measuring device 24, that is, a signal indicating a vibration state, and controls the vibration exciter 4 so that vibration of a set amplitude is applied to the dropping nozzle 3. Output a signal.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited at all by this Example.

Example 1
In Example 1, droplets were generated using a dropping nozzle equipped with the electromagnetic dropping device shown in FIGS. As a cooling medium, 15 ° C. dry air was used. In addition, the vibration applied to the dropping nozzle was fed back by an accelerometer to adjust the vibration applied to the dropping nozzle. Even after 8 hours, the amplitude of the dropping nozzle was constant.

(Comparative Example 1)
In Comparative Example 1, dry air as in Example 1 was not used, and the amplitude caused by vibration applied to the dropping nozzle was not fed back by the accelerometer. After 2 hours, the amplitude of the dropping nozzle became unstable.

FIG. 1 is a view showing an example of an apparatus for producing ammonium heavy uranate particles in which the electromagnetic dripping apparatus according to the present invention is used. FIG. 2 is a diagram illustrating an example of an electromagnetic dropping device according to the present invention. FIG. 3 is a diagram showing an example of the cooling means in the present invention. FIG. 4 is a diagram showing another example of the electromagnetic dropping device in the present invention. FIG. 5 is a diagram showing another example of the electromagnetic dropping device in the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ammonium uranate particle manufacturing apparatus 2 Electromagnetic dripping apparatus 3 Dripping nozzle 4 Exciter 5 Dripping stock solution supply path 6 Flowmeter 7 Separator 8 Liquid feed pump 9 Dripping stock solution storage tank 10 Reaction tank 11 Support member 12 Coil 13 Magnet 14 AC Power supply 15 Cooling means 15A Cooling means 16 Temperature measuring means 17 Cooling control means 18 Cooling medium supply means 18A Cooling medium supply means 19 Temperature sensor 20 Heat absorber 21 Radiator 22 Piping 23 Circulating pump 24 Amplitude measuring instrument 25 Exciter control means 29 Housing 30 Blower pump 31 Heat pump 32 Blower 33A Blower path 33B Blower path

Claims (5)

  An electromagnetic dropping device comprising: a dropping nozzle for dropping a droplet; a vibrator for applying vibration to the dropping nozzle; and a cooling means for cooling the inside of the vibrator.   The cooling means includes temperature measuring means for measuring the temperature inside the vibrator, cooling medium supply means for cooling the inside of the vibrator with a cooling medium, and data relating to the temperature measured by the temperature measuring means. 2. The electromagnetic dripping device according to claim 1, further comprising: a cooling control unit that inputs a control signal and outputs a control signal for controlling the cooling medium supply unit.   The electromagnetic dropping device according to claim 2, wherein the cooling medium is a non-corrosive gas.   A vibration dropping method, wherein a droplet is dropped from a dropping nozzle that is vibrated by a vibrator maintained at a constant temperature by a cooling means. Vibration is applied to the dropping nozzle for dropping a droplet by a vibrator, the amplitude of vibration at the dropping nozzle is measured, data on the measured amplitude is output, and the output data is input, A vibration dropping method, wherein a control signal is output to the vibrator so that the vibrator controls a constant vibration.

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