JP3406172B2 - Vacuum packaging machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum packaging machine for carrying out hermetic packaging by placing food or the like in a heat-adhesive bag-like member and degassing and heat-sealing, and particularly, in the vacuum packaging machine. The present invention relates to a starting technique for a vacuum pump used for evacuation or deaeration.

[0002]

2. Description of the Related Art In a so-called vacuum packaging machine in which food or the like is placed in a heat-adhesive bag-shaped member, the inside of the bag-shaped member is deaerated and depressurized, and then heat-sealed, the so-called vacuum packaging machine Generally, the following steps are performed. That is, a bag-shaped member having one side opening that accommodates an object to be packaged such as food is placed in a vacuum chamber that can be depressurized and is connected to a vacuum pump through a pipe. At that time, the opening side to be closed is
It is placed in a heat sealable position. Next, the lid of the vacuum chamber is closed, and the vacuum pump is operated to perform a degassing step of discharging the gas in the vacuum chamber and the bag-shaped member. When the timer times out and it detects that the pressure in the vacuum chamber communicating with the inside of the bag-shaped member has reached a predetermined pressure,
The heat sealing device performs a sealing step of closing the opening side of the bag-shaped member. Finally, the atmosphere release valve connected to the pipe is opened, the pressure in the vacuum chamber is returned to atmospheric pressure, and the lid is pushed by the raised seal bar for heat sealing to open by itself and then sealed. Remove the bag-shaped member.

Further, after the inside of the vacuum chamber and the bag-shaped member is degassed as described above, a gas such as an inert gas is sealed in the vacuum chamber, and further in the bag-shaped member (gas filling). Process), and thereafter, various types of vacuum packaging machines equipped with a gas filling device for heat-sealing the bag-shaped member are also known.

[0004] In the vacuum pump of the above vacuum packaging machine, oil is generally used for lubrication and airtightness maintenance, but the viscosity of the oil depends on the temperature, and the viscosity may be considerably high in a low temperature state. Are known. Therefore, the vacuum pump may not be smoothly started in the low temperature state. For example, when the ambient temperature drops to about 5 ° C., if the power supply voltage is 100% rated voltage, there is substantially no effect of viscosity increase, but if the power supply voltage drops to 90% rated voltage, it will not be started. Sometimes. still,
The electric circuit is provided with a protector for preventing overcurrent in series with the vacuum pump, and protects the vacuum pump in case of a start failure.

In order to avoid such a start-up failure, generally, the oil characteristic has a high viscosity at a low temperature and a low viscosity at a high temperature. During the season when the oil consumption dropped, measures were taken to use oil with low viscosity.

[0006]

However, with this measure, since the oil used is not the oil recommended by the manufacturer of the vacuum pump, even if it is suitable for the vacuum pump at low temperature, the viscosity becomes too low at high temperature and the oil becomes too oily. Not only can there be problems with the properties, which may render them unusable, but they may also void the manufacturer's warranty in the event of a vacuum pump failure. Therefore, it is an object of the present invention to provide an ultimate solution to a start-up failure of a vacuum pump without causing the above-mentioned guarantee problem.

[0007]

In order to achieve the above-mentioned object, the present invention communicates with a vacuum chamber defined by an openable / closable lid, and evacuates the vacuum chamber and the bag-shaped member therein. An oil rotary vacuum pump, a seal heater for sealing the bag-shaped member in the vacuum chamber, and a valve opened after the bag heater is sealed by the seal heater to open the vacuum chamber to the atmosphere. A vacuum packaging machine for heating the oil rotary vacuum pump by means of the heating heater, the heating device comprising: The body is
When the oil rotary vacuum pump is in operation, the bag-shaped member is sealed.
When the atmosphere is released after the stop, the lid is automatically opened.
The oil rotary vacuum pump to remove the vacuum chamber.
When the air is insufficient, the degassing, sealing and
The lid is not opened even if the series of operations for releasing the air is completed.
A vacuum packaging machine having the following characteristics is provided. in this case,
The heater is preferably attached to the case of the oil rotary vacuum pump, and the vacuum packaging machine has a seal bar that also pushes up the lid so that the lid self-opens when the inside of the vacuum chamber is opened to the atmosphere. It is preferable to provide. The operation of the seal bar is performed by suction of the oil rotary vacuum pump.

By heating the vacuum pump by the heater as described above, the vacuum pump does not fail to start at a low temperature. Further, in a vacuum packaging machine, generally, after heat sealing, the vacuum chamber defined by the lid is opened to the atmosphere. Therefore, by using the opening operation to turn on the heater, an independent process for heating is performed. It is not necessary to provide the above, and the vacuum packaging can be performed quickly. If the heater is attached to the case of the vacuum pump, the heating can be performed quickly and efficiently. Furthermore, the heater is turned on when the atmosphere is open and the heater is turned off when the lid is opened. 2
By adopting one of the operation modes, when the vacuum pump starts up well, the necessary steps can be performed without problems in a relatively short time from the atmosphere opening to the lid opening operation. If the start-up is bad, the lid does not open, and therefore the heater does not turn off but remains in the on state and continues to heat the vacuum pump. In this way
Depending on the situation of the vacuum pump, the heating of the vacuum pump can be performed when the heating is required. In other words, it takes about 10 seconds in the vacuum packaging machine from the opening to the atmosphere to the opening operation of the lid, and if there is no problem with the viscosity of the oil in the vacuum pump, the vacuum pump will start well during this period. Therefore, unnecessary heating of the vacuum pump by the heater is not performed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
In the drawings, the same reference numerals indicate the same or corresponding parts.
FIG. 1 is a vertical cross-sectional view of a vacuum packaging machine in which an embodiment of the present invention is embodied, as seen from the side. In the following description, regarding the position or direction of each part, the left side is "front" and the right side is "rear" as viewed in FIG.
The dotted line in the figure shows the state when the lid of the vacuum packaging machine is closed.

In FIG. 1, a vacuum packaging machine 1 includes a main body 2
And a lid 3 that is located above and that can be opened and closed.
The main body 2 has a box shape, and in its housing a vacuum valve 5 which may be an atmosphere opening valve, an oil rotary vacuum pump 4, an electromagnetically driven solenoid valve, etc., which are not shown in FIG. A seal valve 6, a seal cylinder assembly 7, and the like are provided. The vacuum pump 4 is a branch pipe 8
It is connected to the vacuum valve 5 and the seal valve 6 via. The branch pipe 8 is connected to the outlet side of the vacuum valve 5 and the outlet side of the seal valve 6 on the side opposite to the vacuum pump 4. On the other hand, the inlet side of the vacuum valve 5 is provided with the pipe 9 and the pipe 10.
It is connected to the degassing port 11 located above the rear part of the main body 2 through. The degassing port 11 enables the lid body 3 to suck the gas in the vacuum chamber 12 defined by the lid body 3 in cooperation with the upper surface of the main body 2 when the lid body 3 is closed as described later. , Protrudes from the upper surface of the main body 2. One end of the pipe 13 is connected to the inlet side of the seal valve 6, and the other end is
It is connected to the seal cylinder assembly 7. The atmosphere release valve, which is not shown in FIG. 1, is closed in the degassing process and the sealing process, which will be described later, and is opened so that the pressure in the vacuum chamber 12 becomes the atmospheric pressure after the sealing process is completed.

The lid 3 is a housing having an opening at the bottom, and the above-described vacuum chamber 12 is defined therein, and a series of packaging steps for a package (not shown) which is a bag-shaped member. Is done. As shown by the chain line in FIG. 1, when the lid body 3 is closed so that the peripheral edge portion of the lid body 3 contacts the upper surface of the main body 2, the vacuum chamber 12 defined inside the lid body 3 is The inner surface of the lid 3 and the upper surface of the main body 2 are hermetically sealed via the packing 14. Meanwhile, the vacuum chamber 1
2 communicates with the outside through the opening 3a of the lid 3 when the lid 3 is open as shown by the solid line in FIG. On the inner surface of the upper portion of the lid body 3, an elastic member 15 serving as a heat-bonding portion for sealing and bonding is formed so as to project downward. Packing 1
A magnetic material 16 is provided on the peripheral portion of the lid body 3 at a position outside the position 4 and holds the lid body 3 in a closed state.

On the left and right sides of the rear portion of the lid body 3, there are provided shaft support portions 17 extending in the lateral direction perpendicular to the plane of the drawing.
Rotates about the shaft support 17 including the rotation shaft. Further, an arm portion 18 extending downward from the shaft support 17 is provided at the rear portion of the lid body 3 so as to be rotatable integrally with the lid body 3. The arm portion 18 has an elastic body 19 which is a coil spring.
Further, a leading damper (damping mechanism) 20 or the like that causes resistance only to rotation in a predetermined one direction is attached, but these are not part of the configuration according to the present invention, and therefore will be further described. However, the specification of Japanese Patent Application No. 8-151200 filed by the present applicant can be referred to as necessary.

The seal cylinder assembly 7 includes a decompression chamber 7a,
Heat wire member (seal bar) 7b for sealing and adhesion, piston 7c
And a spring 7d. The decompression chamber 7a is defined by the inner surface of the seal cylinder and the piston 7c, and the sealing bonding heat wire member 7b is attached to the piston 7c. The heat ray member 7b is arranged so as to face the elastic member 15 which is the heat ray receiving portion when the lid 3 is closed, and the tip portion thereof projects from the upper surface of the main body 2. A seal heater is incorporated in the tip of the heat wire member 7b to generate heat when electricity flows, thereby heat-sealing the opening of the bag-shaped package. The spring 7d is arranged in the decompression chamber 7a and applies an elastic force to the piston 7c so as to urge the heat wire member 7b and the piston 7c downward.
Further, the other end of the above-mentioned pipe 13 communicates with the decompression chamber 7a.

As can be seen from FIG. 1, the support member 21 that hangs down inside the main body 2 supports the open / close switch 22 at its lower end. The open / close switch 22 is provided with an operating piece at a position where the connecting rod member 23 is pressed by reaching the rightmost side in FIG. 1 when the lid body 3 is closed as shown by the chain line. Then, the open / close switch 22 is turned on and the vacuum pump 4 is started. Incidentally, such a structure is also described in the above-mentioned Japanese Patent Application No. 8-151200.

Next, FIG. 2 is a circuit diagram showing an embodiment of the operation control device of the present invention implemented in the above-mentioned vacuum packaging machine, in which FIG. 2 is connected in series to a power source (not shown). Is an earth leakage breaker indicated by a reference sign ELB, to which various parallel circuits are connected. First, from the left in the drawing, a vacuum pump VP (denoted by reference numeral 4 in FIG. 1) for degassing the bag-shaped member (not shown) and the vacuum chamber 12 is passed through the vacuum pump protector OL and the normally open contact MS1 of the power relay MS. Connected (C represents a capacitor), and then an air release valve SV1 is connected to a relay X1 which will be described later in order to introduce air into the vacuum chamber 12 to facilitate opening of the lid 3 of the vacuum packaging machine after the end of the hermetic packaging. It is connected through a normally closed contact X12. The transformer TR is connected through the normally open contact X41 of the relay X4, and the secondary side thereof has the above-mentioned seal heater H1 incorporated in the seal bar 7b for heat-sealing the above-mentioned bag-shaped member.

Further, S1 is an open / close switch (2) such as a limit switch which is turned on / off when the lid is opened / closed.
As is well known, the open / close switch S1 is connected to the contact NO when the lid is closed and the contact N when the lid is open.
It is designed to be connected to C. For the contact NO, power relay or magnet switch MS and relay X1
Are connected via the normally closed contact TM31 of the cooling timer TM3. The cooling timer TM3 is a timer for controlling the time for cooling the seal heater H1 after performing heat sealing. On the other hand, a case heater (heater) H2 is connected to the normally open contact TM32 of the cooling timer TM3. The case heater H2 is mounted in the vicinity of the vacuum pump VP, preferably in a case (not shown) of the vacuum pump VP, and heats to raise its temperature.

Connected in parallel to the series body of the case heater H2 and the normally open contact TM32 are a vacuum valve SV2 (5) provided in the tube 9 connected to the above-mentioned vacuum pump VP (4) and a relay. It is a series body composed of a normally open contact X13 of X1 and a normally closed contact X24 of the relay X2, and the contact NC of the above-mentioned on-off switch S1 is connected to this series body between the vacuum valve SV2 and the normally open contact X13. Has been done. Further, the series body connected to the line whose one end extends from the normally open contact X13 and the normally closed contact X24 as shown in the figure is a vacuum timer TM1 and a hold / jump switch S.
No. 2 first normally open contact S21 and normally closed contact X3 of relay X3
2 is included, and the other end of the line is connected between the contact S21 and the vacuum timer TM1. L is a vacuum lamp connected in parallel with the vacuum timer TX1.

The hold / jump switch S2 is
A second normally open contact S22 interlocking with the contact S21 described above,
A normally closed contact S23 is further included, and a relay X3 is connected in series with both contacts. A relay X2 is connected to a line extending between the contacts S22 and S23, and the relay X2 is connected to a parallel body of the normally open contact X23 and the normally open contact TM11 of the vacuum timer TM1. As such a hold / jump switch, for example, a two-pole double-throw switch that performs a momentary operation is suitable, and as will be described later, the process can be maintained and extended while the operator is pressing the switch. Yes, if the pressing is released, it is possible to move to the next step.

Finally, in parallel with both contacts S22 and S23,
The normally open contact X31 of the relay X3 described above is provided, and a series body of the seal valve SV3 and the normally open contact X21 of the relay X2, a line including the seal timer TM2, and a normally open contact of the seal timer TM2 are provided in series with the contact X31. Closed contact TM21 and relay X4 in series, seal timer TM
The two normally open contacts TM22 and the serial body of the cooling timer TM3 are connected in parallel with each other.

The operation of the vacuum packaging machine having the control circuit of the operation control device having the above-described structure is shown in FIG.
In addition to FIG. 2, description will be given with reference to timing charts of FIGS. First, in the normal operation (FIG. 3), the earth leakage breaker ELB is on, the bag-shaped member to be heat-sealed is put into the vacuum chamber 12, and the lid 3 is closed. Is ON and contact NO
, The power relay (magnet switch) MS is turned on, the normally open contact MS1 is closed, and the vacuum pump VP is activated. At the same time, the relay X1 is excited and its normally closed contact X12 is opened to open the atmosphere release valve SV1.
Is closed, the normally open contact X13 is closed and the vacuum valve SV2 is opened to perform vacuuming, that is, deaeration (deaeration step).
Further, the vacuum timer TM1 is turned on via the normally closed contact X24.

When the set time of the vacuum timer TM1 set to perform sufficient degassing has timed up, the contact TM11 is closed and the relays X2 and X3 are excited,
As a result, the normally closed contact X24 is opened and the vacuum valve SV2
When (5) is closed, the normally open contact X21 is closed and the seal valve SV3 (8) is opened. When the seal valve SV3, that is, the seal valve 8 is opened, the inside of the seal cylinder assembly 7 connected to the seal valve 8 is evacuated as shown in FIG. When the inside of the seal cylinder is evacuated, the seal bonding heat wire member (seal bar) 7b of the seal cylinder assembly 7 incorporating the seal heater H1 moves upward due to the pressure difference between the atmospheric pressure and the seal cylinder internal pressure, and is not shown. The bag-shaped member is sandwiched between the elastic member 15 installed on the lid 3 and the seal bar 7b in the vacuum chamber 12. Further, by closing the normally open contact X31 of the excited relay X3, the relay X4 is turned on via the normally closed timer contact TM21, the normally open contact X41 is closed, and the seal heater H1 is energized, and the bag-shaped member is closed. Is heat-sealed (sealing step). Further, the seal timer TM2 is turned on by closing the contact X31.

When the seal timer TM2 expires, its normally closed contact TM21 is opened, the relay X4 is demagnetized, the seal heater H1 is turned off, and the sealing process is completed. At the same time, the cooling timer TM3 is turned on by closing the normally open contact TM22. When the set time of the cooling timer TM3 has elapsed, the normally closed contact TM31 is opened, the magnet switch MS and the relay X1 are turned off, the vacuum pump VP is stopped, and the atmosphere opening valve SV1 is opened. Further, the normally-open contact TM32 of the timer TM3 is closed, and the energization of the case heater H2 preferably installed in the case of the vacuum pump is started.

By opening the atmosphere opening valve SV1,
The inside of the vacuum chamber 12 shown in FIG. However, since the seal cylinder is kept in a vacuum, the seal bar 7b remains elevated, and therefore the lid body 3 is pushed by the seal bar 7b and overcomes the attraction force of the magnetic body 16 to self-open. . Since the open / close switch S1 (22) is turned on / off by the operation of the arm portion 18, the connecting rod member 23, and the like which are interlocked with the open / close operation of the lid body 3, the open / close switch S1 (22) is also provided.
Is on when the lid is closed and off when the lid is open. When the open / close switch S1 is turned off, the contact NC is connected, the vacuum valve SV2 is opened, and the relays X2, X are connected.
3, the seal timer TM2 and the cooling timer TM3 are turned off, the case heater H2 is also turned off, and the initial standby state is restored.

Next, the control method by using the hold / jump switch S2 will be described. 2 and 4
In, magnet switch MS and power relay X1
Is turned on, that is, the power relay X2 is deenergized, the vacuum timer TM1 is energized through the normally closed contact X24, the vacuum pump VP is activated, and the vacuum valve SV2 is opened. When the hold / jump switch S2 is pressed, its normally open contact S22 is closed and the relay X2 is excited, and the normally closed contact X24 is opened, but the other normally open contact S2 of the hold / jump switch is opened.
1 is also turned on, and the vacuum valve SV2 has relay contacts X13 and X32 and the normally open contact S that are all closed.
Since it is held in the open state via 21, the energized vacuum timer TM1 times out and its contact TM1
Even if 1 is closed and relay X2 is excited, vacuum valve SV
2 continues to be in the open state as long as the hold / jump switch S2 is pressed. That is, the vacuum timer TM
The operation of 1 is invalidated, and the deaeration process is held without being controlled by the vacuum timer TM1.

On the other hand, when the hold / jump switch S2 is pressed and immediately released before the vacuum timer TM1 times out, the contact S2 is pressed by pressing the switch S2.
Relay X2 is excited via 2 and its normally open contact X23
Is closed and relay X2 holds itself, so switch S
When the pressure of 2 is released, not only the contact S21 but also the normally closed contact X24 of the relay X2 is opened, the vacuum valve SV2 is turned off, and the deaeration process is forcibly ended. In addition, the release of the switch S2 causes a shift to the sealing step.
That is, the relay X3 is excited through the closed contacts X23 and S23 to close the contact X31, and the seal valve SV is closed.
3, the seal timer TM2, the relay X4 and the seal heater H1 are energized.

Next, as described above, since the vacuum pump VP is filled with oil, the viscosity of the oil increases at low temperatures and the like, so that the switch M of the magnet switch MS is increased.
The vacuum pump VP may not be started even if S1 is turned on. In preparation for this case, the vacuum pump VP (4)
It is preferable that the case heater H2 is attached to the case 4a (see FIG. 1) and the case heater H2 is energized to heat the oil in the vacuum pump VP. FIG. 5 shows a timing chart in the case where the vacuum pump is not started, and the vacuum pump VP is used in the deaeration process for the reason as described above.
If not activated, a well-known protector O for overcurrent protection
When L operates and is turned off, the sealing timer TM2 is energized as described above in the sealing step, and when the time is up, the cooling timer TM3 is energized through the contact TM22 thereof, and the contact TM32 is closed when the time of the timer is up. As a result, the case heater H2 is turned on. If the vacuum pump 4 is not started, the seal bar 7b does not rise in FIG. 1, and thus the lid body 3 remains closed by the attraction force of the magnetic body 16. Therefore, the case heater H2
Keeps on and heats the vacuum pump.

The vacuum pump VP is restarted by opening the lid and closing it again at the discretion of the user. At that time, the oil temperature is sufficiently warm and the vacuum pump can be restarted. On the contrary, if the oil temperature has not risen, the vacuum pump is not restarted and the above steps are repeated, and the case heater is energized again to warm the vacuum pump VP.

The present invention is not limited to the above-mentioned embodiment, and various modifications can be made. For example,
The control circuit according to the modified embodiment shown in FIG. 5 has a gas filling process inserted after the degassing process, and it is possible to perform control by a hold / jump switch in each process of degassing and gas filling. The same can be applied to those configured as described above.

[0029]

As described above, according to the present invention, since the vacuum pump is heated by the heater, the start-up of the vacuum pump does not become defective even in the worst case where the rated voltage drops at a low temperature. It is possible to provide a reliable vacuum packaging machine.

[Brief description of drawings]

FIG. 1 is a schematic side view of a vacuum packaging machine according to an embodiment of the present invention.

2 is a circuit diagram of an operation control device used in the vacuum packaging machine shown in FIG.

3 is an operation timing chart of various devices at the time of timer control by the operation control device of FIG.

FIG. 4 is an operation timing chart of various devices when a hold / jump switch is controlled by the operation control device of FIG.

FIG. 5 is an operation timing chart of various devices when the vacuum pump is not started.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vacuum packaging machine, 3 ... Lid, VP, 4 ... Oil rotary vacuum pump, 4a ... Case, S1, 12 ... Vacuum chamber, 22 ...
Open / close switch, S2 ... Hold / jump switch, H
1 ... Seal heater, H2 ... Case heater, SV1 ... Atmosphere opening valve, SV2, 8 ... Vacuum valve, SV3, 6 ... Seal valve, X1 to X6 ... Relay, TM1 ... Vacuum timer, TM2 ... Seal timer, TM3 ... Cooling timer .

Continuation of the front page (56) References JP-A-1-308719 (JP, A) JP-A-51-87812 (JP, A) JP-A-62-235019 (JP, A) Actual Kaihei 7-43134 (JP , U) Jitsuko Sho 12-18456 (JP, Y1) (58) Fields investigated (Int.Cl. ⁷ , DB name) B65B 31/00-31/10 B65B 57/00-57/20 F04C 23/00 -29/10

Claims (2)

(57) [Claims] 1. An oil rotary vacuum pump that communicates with a vacuum chamber defined by an openable / closable lid to degas the vacuum chamber and the bag-shaped member therein, and a bag-shaped member in the vacuum chamber. A seal heater for sealing, an atmosphere release valve for opening the valve after sealing the bag-shaped member by the seal heater to open the vacuum chamber to the atmosphere, and an opening operation of the atmosphere release valve. A vacuum wrapping machine comprising a heating heater which is turned on in accordance with the above, wherein the heating heater heats the oil rotary vacuum pump , wherein the lid body is the
After the bag-shaped member has been sealed, it is automatically
Open the cover, and use the oil rotary vacuum pump
When the chamber is not sufficiently degassed, the degassing and sealing
And even if the series of operations for opening to the atmosphere is completed, the lid body
Vacuum packaging machine with the characteristic of not opening. 2. The heating heater is the oil rotary vacuum pump.
The vacuum packaging according to claim 1, which is attached to the case of
Machine.