JP2004254637A - Vacuum microwave thawing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum microwave thawing machine generating suppressed noise in the thawing of a thawing object such as food by the irradiation of the inside of a thawing chamber with microwave radiation in evacuated state. <P>SOLUTION: A vacuum pump 16 is placed in a noise attenuating chamber 33 to completely enclose the pump 16 with steel plates and decrease the noise of the vacuum pump 16 leaked from the cabinet 1. A spacer 23 is placed between a connection leg 20 of the vacuum pump 16 and the bottom plate 22 of the cabinet 1 to absorb the oscillation of the vacuum pump 16 with the spacer 23. Accordingly, the transmission of the oscillation from the cabinet to a resonant body such as a door 5 and the amplification of noise can be suppressed. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a vacuum microwave thawing machine for thawing a thawing product such as food based on irradiating microwaves into a thawing chamber under reduced pressure.
[0002]
[Problems to be solved by the invention]
Some of the vacuum microwave thawing machines have a configuration in which the pressure in the thawing chamber is reduced by discharging air in the thawing chamber by a pump. In the case of this configuration, noise such as air discharge noise and motor drive noise is emitted during the operation of the pump. In addition, the vibration of the pump is transmitted to other parts through a vibration transmission medium (resonator) such as a pipe, and resonance occurs between different parts, so that noise is amplified. For this reason, the vacuum microwave thawing machine has to be installed at a place away from the occupants, and the degree of freedom of the installation place is low.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vacuum microwave thawing machine capable of suppressing noise.
[0003]
[Means for Solving the Problems]
<About the invention according to claim 1>
The invention according to claim 1 is characterized in that the storage chamber is partitioned and formed in the outer box, and the pump is stored in the storage chamber. This storage room is formed based on disposing the partition member in the outer box. For example, a room that surrounds the pump from all directions such as front, rear, left, right, up, and down corresponds to the storage room. The constituent material of the storage room may be any of a sound absorbing material, a sound insulating material, a sound insulating material, and a combination thereof.
According to the first aspect of the present invention, since the pump is surrounded by the chamber wall of the storage room, noise from the pump does not easily leak to the outside of the storage room. For this reason, noise becomes difficult to be transmitted to the occupants and the like, so that the degree of freedom of the installation location of the vacuum microwave decompressor is increased.
[0004]
<About the invention according to claim 2>
The invention according to claim 2 is characterized in that a noise prevention member is provided on the room wall of the storage room. The noise preventing member may be any of a sound absorbing material, a sound insulating material, a sound insulating material, and a combination thereof, and the surface on which the noise preventing member is to be mounted may be any of the inner surface, outer surface, and inner and outer surfaces of the room wall. The wall on which the noise prevention member is to be mounted may be either all the room walls or some of the room walls.
According to the second aspect of the present invention, since the noise prevention member is provided on the chamber wall of the storage room, the noise from the pump is less likely to leak to the outside of the storage room. For this reason, the noise is more difficult to be transmitted to the occupants and the like, so that the degree of freedom such as the installation location of the vacuum microwave decompressor is increased.
[0005]
<About the invention according to claim 3>
The invention according to claim 3 is characterized in that a vibration preventing member is interposed between the pump and a portion to which the pump is mounted. The vibration preventing member has a function of suppressing vibration of the mounted portion, and a member that suppresses vibration of the mounting portion of the pump itself and a member that absorbs vibration of the mounting portion correspond to the vibration preventing member.
According to the third aspect of the present invention, since the pump is mounted on the mounting portion via the vibration preventing member, vibrations from the pump are transmitted through the mounting portion to the resonator such as the outer box, the door, and the thawing chamber. It is difficult to be transmitted to. For this reason, the vibration or noise caused by the vibration is suppressed, so that the degree of freedom such as the installation location of the vacuum microwave thawing machine is increased.
[0006]
<About the invention according to claim 4>
The invention according to claim 4 is characterized in that a muffler is provided at the exhaust port of the pump. This silencer completely eliminates noise from the pump or relatively reduces the noise as compared with the case without the silencer, and the form of the silencer is not limited. This silencer may be directly connected to the exhaust port of the pump, or may be interposed in the exhaust path.
[0007]
According to the fourth aspect of the present invention, since the muffler is provided at the exhaust port of the pump, exhaust noise from the pump is reduced. For this reason, noise can be suppressed, and the degree of freedom of the installation location of the vacuum microwave thawing machine is increased.
[0008]
<About the invention according to claim 5>
The invention according to claim 5 is characterized in that a vibration preventing member is provided in a pipe. The pipe refers to a path connecting the suction port of the pump to the thawing chamber, and the vibration preventing member includes a member for suppressing the vibration itself of the pipe and a member for absorbing the vibration of the pipe.
According to the fifth aspect of the present invention, since the vibration preventing member is provided in the pipe of the pump, it is difficult for the vibration from the pump to be transmitted to the resonator such as the outer box, the door, and the thawing chamber through the pipe. For this reason, vibration or noise due to the vibration is suppressed, so that the degree of freedom such as the installation location of the vacuum microwave thawing machine is increased.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
First Embodiment A first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a cross-sectional view showing the entire configuration of the vacuum microwave thawing machine from the side. As shown in FIG. 1, the cabinet 1 is formed by forming a steel plate into a vertical box shape with an open front surface, and a base of a plurality of casters 2 is fixed to a lower surface of the cabinet 1. Note that the cabinet 1 corresponds to an outer box.
[0010]
In the cabinet 1, a chamber 3 is fixed at an upper position. The chamber 3 corresponds to a thawing chamber, and is constituted by a metal pressure-resistant container having an opening 4 on the front surface. Further, a door 5 is attached to the cabinet 1 so as to be rotatable about a vertical axis on the right side, and a handle 6 for opening and closing operation is fixed to a front surface of the door 5. The opening 4 of the chamber 3 is opened and closed based on the turning operation of the door 5 with the handle 6. An operation panel is fixed to the cabinet 1 above the door 5, and an operation switch and a display unit (both not shown) are fixed to the operation panel.
[0011]
A lock mechanism (not shown) is mechanically connected to the handle 6, and when the handle 6 is rotated with the door 5 closed, the lock plate of the lock mechanism is engaged in the lock hole of the cabinet 1. Then, the door 5 is locked so that it cannot be opened by the engagement force between the lock plate and the lock hole. The axis of the door 5 is movable in the front-rear direction, and the door 5 is moved rearward by the engaging force between the lock plate and the lock hole based on the lock that cannot be opened.
[0012]
A turntable motor 7 with a speed reducer is fixed in the cabinet 1 below the chamber 3, and an output shaft 8 of the turntable motor 7 passes through a lower plate (bottom plate) of the chamber 3. It protrudes into. A circular dish-shaped turntable 9 is detachably mounted on the upper end of the output shaft 8 at the bottom of the chamber 3, and the turntable 9 is driven to rotate by a turntable motor 7.
[0013]
An atmosphere release valve, a pressure regulating valve, a vacuum pressure sensor, a discharge sensor (all not shown), and a magnetron 10 are mechanically connected to the rear plate of the chamber 3. The open-to-atmosphere valve is a solenoid valve that switches between a valve-open state and a valve-closed state. Based on the switching from the valve-closed state to the valve-open state, the inside of the chamber 3 communicates with the outside and is in a depressurized state. The inside of the chamber 3 is returned to the atmospheric pressure. The pressure regulating valve has a built-in opening adjustment mechanism using a motor as a drive source, and the opening adjustment mechanism adjusts the opening degree of the pressure regulating valve according to the rotation amount of the motor. The vacuum pressure sensor detects the internal pressure of the chamber 3 and outputs an electric signal at a level corresponding to the detected pressure. The discharge sensor detects the presence or absence of a discharge in the chamber 3 and includes an optical sensor that detects the presence or absence of a discharge light. The magnetron 10 is fixed to a rear plate of the chamber 3 via a waveguide 11, and irradiates the chamber 3 with microwaves through the waveguide 11.
[0014]
An exhaust pipe 12 made of stainless steel is connected to the upper plate of the chamber 3. The exhaust pipe 12 has a U-shaped upper connection portion 13a connected to the upper plate of the chamber 3, a vertical main body portion 14, and a horizontal lower connection portion 13b. Is located on the outer peripheral surface, and a vibration damping material 15 is wound therearound. The anti-vibration member 15 corresponds to an anti-vibration member, and is made of, for example, rubber, and is disposed in an upper portion of the main body portion 14 which is deviated from a central portion in the vertical direction.
[0015]
The lower connection portion 13 b of the exhaust pipe 12 is connected to the intake port 18 of the exhaust fan 17. The exhaust fan 17 constitutes a vacuum pump 16 together with the pump motor 19 and the connecting leg 20. The exhaust fan 17 and the pump motor 19 are mechanically connected via the connecting leg 20. The air blower 17 operates based on the driving of the pump motor 19, and reduces the pressure in the chamber 3 based on discharging the air in the chamber 3 through the air distribution pipe 12.
[0016]
A plurality of shafts 21 are fixed to the connection leg 20, and the vacuum pump 16 is fixed in the cabinet 1 so as not to be displaced based on the insertion of the plurality of shafts 21 into the bottom plate 22 of the cabinet 1. A spacer 23 made of, for example, rubber is inserted as an anti-vibration member into the outer peripheral surface of each of the shafts 21. Each spacer 23 is interposed between the connection leg 20 and the bottom plate 22 of the cabinet 1. The vacuum pump 16 is kept separated from the bottom plate 22.
[0017]
The vacuum pump 16 is wound with a sound absorber 24 for a fan and a sound absorber 25 for a motor, which are positioned on the outer peripheral surface of the exhaust fan 18 and the outer peripheral surface of the pump motor 19. The sound absorber for the exhaust fan 24 and the sound absorber for the motor 25 are formed of, for example, a porous resin such as urethane, and absorb the sound of the exhaust fan 18 and the sound of the drive from the pump motor 19. Based on these noise suppression. In addition, the sound absorber for the exhaust fan 24 and the sound absorber for the motor 25 correspond to a noise prevention member.
[0018]
A silencer 27 is connected to a discharge port 26 of the exhaust fan 18. The silencer 27 corresponds to a silencer for reducing exhaust noise discharged from the discharge port 26, and a detailed configuration of the silencer 27 will be described below with reference to FIG.
[0019]
The sound absorbing material case 28 is formed of a synthetic resin in a cylindrical shape, and a ring-shaped end plate 29 is fixed to one end of the sound absorbing material case 28. A cylindrical connection port 30 is fixed to the other end of the sound absorbing material case 28, and the connection port 30 is connected to the discharge port 26 of the exhaust fan 17. A sound absorbing material 31 is housed in the sound absorbing material case 28. The sound absorbing material 31 is made of a resinous porous body, and reduces the sound absorption based on absorbing the exhaust sound. The silencer 27 is configured as described above.
[0020]
A partition plate 32 made of a steel plate is fixed to the bottom plate 22 of the cabinet 1 as shown in FIG. The partition plate 32 has a rectangular box shape with an open lower surface, and forms a soundproof room 33 in the cabinet 1 in cooperation with the bottom plate 22 of the cabinet 1. The soundproof room 33 corresponds to a storage room in a sound sealed state isolated from the chamber 3, and the vacuum pump 16 and the silencer 27 are housed in the soundproof room 33 and connected to the lower side of the air distribution pipe 12. The portion 13 b penetrates through the partition plate 32 and is connected to the intake port 18 of the exhaust fan 17 inside the soundproof room 33.
[0021]
As shown in FIG. 2A, a sound absorbing material 34 corresponding to a noise prevention member is fixed to the inner surface of the soundproof room 33. The soundproof room 33 is configured based on bending a cross-shaped steel plate 35 as shown in an expanded state in FIG. 2B. The sound absorbing material 34 is for closing the joint of the steel plates 35 from the inside of the soundproof room 33, and is formed of a porous resin such as urethane. The partition plate 32 corresponds to a partition member. In addition, the term “joint portion” of the steel plate 35 is a term that indicates a joint.
[0022]
A control device (not shown) mainly composed of a microcomputer is provided in the cabinet 1. An operation control program is recorded in a ROM of the control device, and the control device is based on output signals from an operation switch, a discharge detection sensor, a vacuum pressure sensor, a turntable motor 7, a magnetron 10, an atmosphere release valve, a pressure regulating valve. Drive control of the pump motor 19 to control the vacuum thawing operation of food. Hereinafter, the details of the vacuum thawing operation will be described with reference to FIG.
[0023]
When the control device detects that the operation switch has been started in the closed state of the door 4, the control device drives the vacuum pump 16 in the closed state of the air release valve and the pressure regulating valve and in the completely closed state. Then, the vacuum pump 16 sucks the air in the chamber 3 and evacuates the chamber 3 based on the reduced pressure. The pressure in the chamber 3 is reduced from the atmospheric pressure of about 101 [kPa] (reference value: 760 [Torr]), and the controller continuously operates the vacuum pump 16 until the internal pressure of the chamber 3 reaches the decompression equilibrium region F. The decompression process is performed based on the driving of the decompression device, and the defrosted product is pre-thawed based on the decompression process. The decompression equilibrium region F is a region where the amount of decompression ΔP per unit time becomes “0”, and the equilibrium pressure in the decompression equilibrium region F rises and falls according to the saturated vapor pressure in the chamber 3.
[0024]
The control device detects a pressure signal from the vacuum pressure sensor while the vacuum pump 16 is being driven, and calculates a reduced pressure amount ΔP based on the detection result of the pressure signal. Then, it is determined whether or not the inside of the chamber 3 has reached the decompression equilibrium range F based on comparing the calculation result ΔP of the decompression amount with the reference value. Here, when it is determined that the internal pressure of the chamber 3 has reached the decompression equilibrium region F, the operation of the vacuum pump 16 is stopped, and the operation of the vacuum pump 16 is stopped. The internal pressure is increased from the decompression equilibrium region F.
[0025]
The control device detects the internal pressure of the chamber 3 when the pressure regulating valve is open, and compares the detection result of the internal pressure with a lower limit P1 (for example, about 1.3 [kPa] (reference value: 10 [Torr]). P1 corresponds to a limit value at which vacuum discharge does not occur even when microwaves are radiated into the chamber 3. When the control device detects that the detection result of the internal pressure has reached the point C exceeding the lower limit value P1, The microwave is irradiated into the chamber 3 based on the start of driving the magnetron 10.
[0026]
The control device detects the internal pressure of the chamber 3 while the magnetron 10 is being driven, and compares the detection result of the internal pressure with an upper limit value P2 of the return pressure (for example, about 6.7 [kPa] (reference value: 50 [Torr])). Here, when it is detected that the detection result of the internal pressure has reached the return pressure upper limit value P2, the pressure regulating valve is completely closed, and the vacuum pump 16 is driven again in the completely closed state to restart the pressure reduction process in the chamber 3 again. Execute.
[0027]
The control device detects the internal pressure of the chamber 3 while the vacuum pump 16 is being driven again, and compares the detection result of the internal pressure with the lower limit value P1. Here, if it is detected that the detection result of the internal pressure has reached the lower limit value P1, the irradiation of the microwave is terminated based on stopping the driving of the magnetron 10. When it is detected that the internal pressure of the chamber 3 has reached the decompression equilibrium region F, the operation of the vacuum pump 16 is stopped, and the above series of operations is repeated. Then, the saturated vapor pressure in the chamber 3 increases based on the temperature rise of the defrosted product, so that the reduced pressure value ΔP becomes “0” at a high internal pressure. The control device compares the internal pressure when the pressure reduction value ΔP becomes “0” with the decompression end value, and when detecting that the internal pressure has risen to the decompression end value, opens the air release valve and ends the defrosting operation.
[0028]
According to the first embodiment, the entire vacuum pump 16 is surrounded by a steel plate based on the fact that the vacuum pump 16 is housed in the soundproof room 33. For this reason, the intake / exhaust sound and the drive sound from the exhaust fan 17 and the pump motor 19 are reflected or absorbed by the inner surface of the soundproof room 33, so that the noise emitted from the vacuum pump 16 to the outside of the cabinet 1 is reduced. Is done. Therefore, the vacuum microwave thawing machine can be installed in a place where noise is disliked, such as a restaurant or a hotel kitchen, so that the degree of freedom of installation of the vacuum microwave thawing machine is increased. In addition, since the vacuum microwave decompressor can be used even in a time zone where noise is noticeable, such as late night or early morning, the degree of freedom of the use time period of the vacuum microwave decompressor increases.
[0029]
Further, the vibration isolator 16 was wound around the exhaust pipe 12. Therefore, the resonance of the exhaust pipe 12 due to the vibration from the vacuum pump 16 is suppressed, so that the noise caused by the vibration of the exhaust pipe 12 is suppressed.
Further, a spacer 23 is provided between the connection leg 20 of the vacuum pump 16 and the bottom plate 22 of the cabinet 1, and the vibration of the vacuum pump 16 is absorbed by the spacer 23, so that the vibration is transmitted from the vacuum pump 16 to the bottom plate 22 of the cabinet 1. Is suppressed. For this reason, the transmission of vibration from the cabinet 1 to the resonators such as the door 5, the chamber 3, the exhaust pipe 12, and the like is also suppressed, so that the noise caused by the transmission of the vibration of the vacuum pump 16 to the resonators such as the cabinet 1 is reduced. Amplification is also suppressed.
[0030]
Further, the outer peripheral surfaces of the exhaust fan 17 of the vacuum pump 16 and the pump motor 19 were covered with a sound absorber for exhaust 24 and a sound absorber 25 for motor. For this reason, since the noise of the vacuum pump 16 itself is suppressed, the diffusion of the noise from the vacuum pump 16 into the soundproof room 33 is further suppressed.
Further, a silencer 27 is provided at the discharge port 26 of the exhaust fan 17. For this reason, since the exhaust sound from the exhaust fan 17 is absorbed by the silencer 27, noise due to the exhaust sound from the exhaust fan 17 is suppressed.
Further, a sound absorbing material 34 is provided on the inner surface of the partition plate 32. For this reason, the sound of pumping and exhausting and the driving sound from the vacuum pump 16 are absorbed by the sound absorbing material 34, so that the noise emitted from the vacuum pump 16 to the outside of the cabinet 1 is further reduced.
In addition, a sound absorbing material 34 was provided at the joint of the partition plate 32. For this reason, since the joining part of the partition plate 32 is reliably closed by the sound absorbing material 34, it is possible to prevent noise from leaking outside through the joining part of the partition plate 32. In addition, since vibrations from the vacuum pump 16 do not directly contact between the joining end surfaces of the partition plate 32, contact noise is also prevented.
[0031]
FIG. 4A shows an experimental result obtained by measuring noise outside the cabinet 1 of the invention, and FIG. As shown in the figure, in this embodiment, the sound (noise) is smaller at all frequencies as compared with the conventional product, and the sound is remarkably increased especially at the operating frequency (50 HZ) and a frequency that is an integral multiple of the operating frequency. It is getting smaller.
[0032]
In the first embodiment, the sound absorbing material 34 is provided on a part of the partition plate 32. However, the present invention is not limited to this. For example, as shown in FIG. 6 showing a second embodiment of the present invention. Alternatively, a soundproof material 34 may be provided on the entire inner surface of the partition plate 32.
In the first embodiment, the sound absorbing material 34 is provided over the entire area of each joint of the partition plate 32. However, the present invention is not limited to this. For example, the sound absorbing material 34 may be provided only at the upper and lower corners.
[0033]
Next, a third embodiment of the present invention will be described with reference to FIG.
A horizontal partition plate 50 is fixed in the cabinet 1. The partition plate 50 corresponds to a partition member, and forms a soundproof room 54 isolated below the chamber 3 in cooperation with the left side plate 51, the right side plate 52, and the bottom plate 53 of the cabinet 1. The soundproof room 54 corresponds to a storage room in which the vacuum pump 16 is stored, and a plurality of urethane sound absorbing materials 55 are attached to the inner surface of the soundproof room 54.
[0034]
In the first to third embodiments, the vibration isolator 15 is wound around a part of the exhaust pipe 12. However, the present invention is not limited to this. For example, the fourth embodiment of the present invention As shown in FIG. 8, the exhaust pipe 12 may be wound around substantially the entire area of the upper connection portion 13 a and substantially the entire area of the main body 14.
In the first to fourth embodiments, the rubber material is used as the vibration isolator 15 for the exhaust pipe 12. However, the present invention is not limited to this. For example, a porous material such as sponge or urethane may be used. A resin body or a metal plate may be used.
[0035]
In the first to fourth embodiments, the urethane porous resin body is used as the sound absorber 24 for the exhaust fan of the vacuum pump 16 and the sound absorber 25 for the motor. However, the present invention is not limited to this. Instead, for example, an elastic body such as rubber may be used, or a metal plate such as aluminum may be used. In particular, when the temperature of the vacuum pump 16 rises, a metal plate is effective in preventing deterioration of the sound absorbing material.
In the first to fourth embodiments, the partition plates 32 and 50 are made of a steel plate. However, the partition plates 32 and 50 are not limited to this. For example, materials having excellent sound absorbing properties such as elastomers and rubbers are used. May be formed.
It is not necessary to strictly separate the functions of the sound absorbing material and the vibration damping material. For example, the sound absorbing material and the vibration damping material may be implemented by using rubber or the like so as to also serve as the sound absorbing material and the vibration damping material.
[Brief description of the drawings]
1 shows a first embodiment of the present invention, and is a cross-sectional view showing the entire internal configuration of a vacuum microwave defroster from a side. FIG. 2 (a) is a cross-sectional view showing the internal configuration of a soundproof room. (B) is an exploded view of a partition plate. [FIG. 3] A view showing the internal structure of a silencer partially cut away. [FIG. 4] A view showing noise outside a vacuum microwave defroster, and (a) is an invention product. (B) is a conventional product. [FIG. 5] is a diagram showing the operation of thawing cooking. [FIG. 6] is a diagram showing a second embodiment of the present invention, and is a diagram corresponding to FIG. 2 (a). FIG. 8 shows a third embodiment, and is a cross-sectional view showing the entire internal configuration of a vacuum microwave defroster from the front. FIG. 8 shows a fourth embodiment of the present invention, showing an exhaust pipe. Description]
1 is a cabinet (outer box), 3 is a chamber (thawing room), 15 is a vibration isolator (vibration preventing member), 16 is a vacuum pump (pump), 23 is a spacer (vibration preventing member), 26 is a discharge port (exhaust). Mouth), 27 are silencers (mufflers), 32 is a partition (partition member), 33 is a soundproof room (storage room), 34 is a sound absorbing material (noise prevention member), and 50 is a partition plate (partition member).

Claims (5)

In the configuration in which the thawing material stored in the thawing chamber is thawed based on irradiating the microwave in the thawing chamber with reduced pressure,
An outer box having the thawing chamber,
A pump for decompressing the thawing chamber,
A vacuum microwave thawing machine, comprising: a partition member provided in the outer box, for forming a storage chamber surrounding the pump in the outer box. The vacuum microwave defroster according to claim 1, wherein a noise prevention member is provided on a wall of the storage room. In the configuration in which the thawing material stored in the thawing chamber is thawed based on irradiating the microwave in the thawing chamber with reduced pressure,
A pump for decompressing the thawing chamber,
A vacuum microwave thawing machine comprising: the pump; and a vibration preventing member provided between the attached parts to which the pump is attached. In the configuration in which the thawing material stored in the thawing chamber is thawed based on irradiating the microwave in the thawing chamber with reduced pressure,
A pump for decompressing the thawing chamber,
A vacuum microwave thawing machine, comprising: a muffler provided at an exhaust port of the pump. In the configuration in which the thawing material stored in the thawing chamber is thawed based on irradiating the microwave in the thawing chamber with reduced pressure,
A pump for decompressing the thawing chamber through piping,
A vacuum microwave thawing machine comprising: a vibration preventing member provided on the pipe.

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