JP3728380B2 - Vacuum packaging method and apparatus - Google Patents

Description

[0001]
[Prior art]
As shown in FIG. 9, the rotary vacuum packaging apparatus has a plurality of pressure-resistant chambers 1, 2 that circulate in an endless track 3 at equal intervals, and the opening hole 4 of the pressure-resistant chamber 1 communicates with a vacuum port 7 of a valve 6. The vacuum is applied to the bag-packed product previously stored in the pressure-resistant chamber 1 only while the pressure-resistant chamber 1 is on. In the drawing, the valve 6 is shown in a straight line, but the valve 6 is a circular rotary type. When the opening hole 4 of the front chamber 1 is removed from the vacuum port 7 for efficiency improvement. The opening hole 5 of the rear chamber 2 is immediately connected to the vacuum port 7.
[0002]
[Problems to be solved by the invention]
As described above, the rotary vacuum packaging apparatus is configured to isolate each pressure-resistant chamber and bring about a vacuum. Therefore, if the number of pressure-resistant chambers 1, 2,... In the endless track 3 is increased in order to increase mass production efficiency, As the number of pressure chambers increases, the length of the vacuum port 7 must be shortened, and the vacuum action time of the pressure chamber becomes insufficient accordingly. As a result, the efficiency does not increase beyond a certain limit unless the entire apparatus is enlarged. Therefore, the present invention is intended to improve efficiency without increasing the size of the apparatus.
[0003]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a normally closed auxiliary port in front of the vacuum port in the traveling direction of the pressure chamber, and performs a preliminary vacuum action on the pressure chamber with the auxiliary port. The vacuum action time (vacuum volume) in each pressure-resistant chamber is expanded without reducing the traveling speed.
[0004]
DETAILED DESCRIPTION OF THE INVENTION
In the vacuum packaging method of the present invention, a normally closed auxiliary port is formed in front of the vacuum port in the fixed plate of the rotary valve, and each opening hole of the movable plate that rotates in surface contact with the fixed plate overlaps the auxiliary port. Each time the auxiliary port is temporarily opened, a preliminary vacuum is applied to each pressure-resistant chamber connected to each auxiliary port. For this reason, the vacuum volume acting on each pressure-resistant chamber is expanded by the preliminary vacuum.
[0005]
One example of means for normally closing the auxiliary port can be configured by providing an opening / closing valve in a pipe line connecting the auxiliary port and the vacuum source and keeping the opening / closing valve normally closed.
[0006]
The means for temporarily opening the auxiliary port each time each opening hole of the movable plate overlaps with the auxiliary port is provided with, for example, operating pieces at a pitch equal to each opening hole on the peripheral surface of the movable plate, and the passage of these operating pieces. Place the sensor in the area. While the operating piece passes through the sensor installation area, the sensor senses the operating piece and transmits a signal. Therefore, the open / close valve is opened by an electromagnetic force by the signal during the signal transmission time.
[0007]
In addition, the rotation angle detector engaged with the operating shaft of the movable plate can determine the pitch of each opening hole formed in the movable plate with the rotation of the operating shaft. By using it, it is possible to detect the timing at which the preceding opening hole is removed from the vacuum port without any error, and at the same time to open the on-off valve and apply a preliminary vacuum to the pressure-resistant chamber in contact with the subsequent opening hole.
[0008]
The on-off valve is not necessarily an electromagnetic structure, and can be implemented in a pure machine type. For example, an all-around cam fixed to the operating shaft of the movable plate is provided opposite to the normally closed on-off valve, and the on-off valve is switched by applying intermittent pressure of the all-around cam to a knock pin at the spool end of the valve. By forming the circumferential cam in a shape that matches the pitch of each opening hole, it is possible to open the on-off valve by catching the timing when the preceding opening hole is removed from the vacuum port.
[0009]
Immediately after the preceding opening hole is removed from the vacuum port, the normally closed auxiliary port can be opened, and a vacuum can be applied immediately to the subsequent opening hole, so that each pressure chamber can be operated without reducing the pressure chamber progress speed. The vacuum volume can be increased, and the mass production efficiency of the vacuum packaged product can be improved. Since it is obvious that the pressure-resistant chamber has a sealing means for the packaging container inside, the detailed configuration is omitted.
[0010]
【Example】
The vacuum packaging apparatus shown in FIG. 3 has a fixed plate 12 having a circular shape in plan view fixed to a top end surface of a cylindrical central shaft 11 fixed on a machine base 10 with screws 13 and at the lower end of the central shaft. A vacuum source, that is, a vacuum pump 15 connected via a line 14 and a vacuum port 16 formed on the upper surface of the fixed plate are communicated via a central cavity inside the central axis, and further, a ball bearing around the central axis 11 A circular rotor 19 is fixed to an upper end of a cylindrical main shaft 18 provided via 17, and a pressure chamber 21 is fixed to each tip of a large number of arms 20 projecting radially from the rotor. An opening hole 23 of the movable plate 22 rotatably arranged on the plate 12 and the pressure-resistant chamber 21 are connected via a tube 24.
[0012]
As shown in detail in FIG. 1, the above-mentioned fixed platen 12 is indicated by a solid line, and a part of the movable platen 22 is also indicated by a phantom line. Are connected to the aforementioned pressure chamber 21 and the vacuum port 16 formed in the stationary platen 12 is connected to the vacuum pump 15 via the line 14 as described above.
[0013]
The first operating shaft 25 and the second operating shaft 26 shown in FIG. 3 are connected via a bevel gear 27, and a pinion 28 fixed to the operating shaft is engaged with a gear 29 fixed to the main shaft 18, By transmitting the driving force of the first operating shaft 25 to the main shaft 18 and the rotor 19, the movable platen 22 connected to each pressure-resistant chamber 21 via the tube 24 receives the moving force of the pressure-resistant chamber 21 and is integrated with the rotor 19. Rotate. Such movement means that the movable platen 22 rotates in the clockwise direction as shown by an arrow 30 in FIG. 1, and a vacuum is applied to the pressure resistant chamber only while each opening hole 23 passes over the vacuum port 16.
[0014]
In FIG. 1, an oval auxiliary port 31 formed in front of the vacuum port 16 in the traveling direction of each opening hole 23 is connected to the main line 14 via an auxiliary conduit 32. The on-off valve 33 provided in the pipe line 32 is a normally closed type, and the on-off valve 33 holds the auxiliary port 31 in a normally closed state.
As illustrated in FIG. 2, the on-off valve 33 maintains the closed position by the pressing force of the spring 34 , and switches to the open position when the sensor 35 represented by the switch symbol is closed.
[0016]
A proximity switch 35 shown in FIG. 1 is known as a specific example of the sensor. The proximity switch 35 is closed and the on-off valve 33 is opened only while the operating piece 36 traveling at the same pitch as the interval between the opening holes 23 passes through the region of the proximity switch 35. In this case, each operating piece 36 is fixed to the peripheral surface of the movable platen 22. As other types of sensors, various types of sensors such as a photoelectric type and a touch type are known.
[0017]
As seen in FIG. 2, the movable platen 22 moves in the direction of the arrow 30 on the upper surface of the fixed platen 12 and the opening hole 23A at the front is removed from the vacuum port 16, and at the same time, the on-off valve 33 is switched to the open position. A vacuum acts on the rear opening hole 23B overlapping the port 31. The positional relationship between the holes is as shown in FIG. 4. Even when the positional relationship is as shown in FIG. 5, the auxiliary port 31 is kept open, and the opening hole 23B is completely moved to the area of the vacuum port 16 as shown in FIG. The auxiliary port 31 is closed.
[0018]
From the concept of preliminary vacuum, Japanese Patent Application No. 62-182014 is known. As shown in FIG. 10, the four gap holes 8 and 9 on the upper surface of the fixed plate 6 are connected by an internal arcuate cavity W, while the four open holes that rotate the upper surface of the solid plate 6 in the direction of the arrow. Among them, the opening hole 4 and the opening hole 5 which overlap the gap holes 8 and 9 respectively are communicated with each other through the cavity W. In short, the atmosphere in the pressure-resistant chamber connected to one opening hole 4 is sucked into the pressure-resistant chamber connected to the other opening hole 5 and preliminarily evacuated, and then the opening hole 4 communicates with the vacuum port 7 to perform the main vacuum. Receive. The packaged product in the pressure chamber of the other open hole 5 has already been vacuumed at this time, and this is significant in that this extra vacuum energy is utilized in the pressure chamber of the one open hole 4. However, if there is not provided at least an interval X in which the opening hole 4 is accommodated between the vacuum port 7 and the gap hole 8, there is a problem that the vacuum port 7 is connected to the other opening hole 5 through the one opening hole 4. Although it is possible with an apparatus having a small number of opening holes 4 as shown in FIG. 1, it is impossible to dispose the gap holes 9 through the gap X in the apparatus having eight pressure-resistant chambers as shown in FIG. Become. If allowed, the auxiliary port 31 shown in FIG. 1 is formed between the vacuum port 7 and the gap 9 in FIG. 10, and after the primary preliminary vacuum through the cavity W in FIG. When a secondary preliminary vacuum is performed through the auxiliary port 31, the vacuum volume is further expanded.
[0019]
An angle detector 41 is formed by an encoder 39 connected to the operating shaft 26 of FIG. 3 via a chain 38 and a controller 40 for processing an input signal from the encoder. The means processes the pulse signal transmitted from the encoder 39 to detect the rotation angle of the movable platen 22 and opens the on-off valve 33 in accordance with the movement pitch of each opening hole.
[0020]
The on-off valve 44 shown in FIG. 7 has a pure mechanical structure, unlike the electromagnetic type. The all-around cam 46 fixed to the operating shaft 45 that drives the movable plate opens the normally closed on-off valve 44 only while touching the knock pin 47 provided at the end of the valve spool. In some cases, the crank mechanism can be operated by the operating shaft 45, and the on-off valve 44 can be opened by this crank mechanism.
[0021]
Since the failure rate of the on-off valve 44 is increased according to the switching frequency, as shown in FIG. It is also a plan to use it.
[Brief description of the drawings]
[Fig. 1] Plan view [Fig. 2] Cross-sectional view [Fig. 3] Side view of the entire apparatus [Fig. 4] Position relationship between the vacuum port and each opening hole [Fig. [Fig. 6] Positional relationship diagram between vacuum port and each opening hole [Fig. 7] Explanatory diagram of on-off valve [Fig. 8] Explanatory diagram of auxiliary conduit [Fig. 9] Explanatory diagram of conventional example [Fig. 10] Conventional example Explanation drawing [Explanation of symbols]
12 ... Fixed plate 15 ... Vacuum source 16 ... Vacuum port 21 ... Pressure chamber 22 ... Movable plate 23 ... Open hole 31 ... Auxiliary port 33 (44) ... Open / close valve (normally closed means) 35 ... Sensor 41 ... Rotation angle detector 45 ... Operating shaft 46 ... All-around cam

Claims (6)

A movable plate in which a large number of opening holes are circularly arranged at equal intervals is rotated in contact with the surface of the fixed platen, and the opening holes are communicated with the vacuum ports formed in the fixed platen at a fixed interval. In the packaging means in which a vacuum suction force is applied to the packaged product in each pressure-resistant chamber connected through the vacuum port , an auxiliary port is provided on the stationary plate at the front of the vacuum port toward the traveling direction of the opening hole. The auxiliary port and the vacuum pump are connected via a normally-closed on-off valve, and each opening hole formed in the movable plate is connected to the auxiliary port in front of the vacuum port. A vacuum packaging method in which a preliminary vacuum is applied to the pressure-resistant chamber by temporarily opening the vacuum chamber . A vacuum source is connected to a movable plate that has a large number of opening holes formed in a circular array at equal intervals, a pressure-resistant chamber that is connected to each opening hole of the movable plate, and a vacuum port that is formed on the surface that the movable plate contacts. The movable platen is rotated integrally with the pressure-resistant chamber at the contact surface between the fixed plate and the fixed platen, and each pressure-resistant chamber is fixed to the vacuum port through each opening hole of the movable platen. An auxiliary port formed in front of the vacuum port in the stationary platen in the direction of travel of each opening hole and an auxiliary pipe connecting the auxiliary port and the vacuum source. Each time the opening hole overlaps the normally closed opening / closing valve and the auxiliary port, the opening / closing valve is temporarily opened to apply a preliminary vacuum to each pressure-resistant chamber connected to the opening hole. A vacuum packaging device comprising: The auxiliary port and the vacuum source are connected by a plurality of parallel auxiliary pipelines, and each of the auxiliary pipelines is provided with a normally closed on-off valve, and each opening hole is provided at a certain time interval in the auxiliary port. The vacuum packaging apparatus according to claim 2, further comprising means for alternately opening the plurality of on-off valves each time they overlap each other. When each opening hole overlaps the auxiliary port at a certain time interval, the means for temporarily opening the on-off valve is only while each operating piece provided at the same pitch as each opening hole passes through the sensor installation area. The vacuum packaging apparatus according to claim 2 or 3, wherein the open / close valve is switched to an open position by a signal from the sensor. When each opening hole overlaps the auxiliary port at a fixed time interval, the means for temporarily opening the on-off valve is to determine the movement pitch of each opening hole by the rotation angle detector engaged with the operating shaft of the movable platen. 4. The vacuum packaging machine apparatus according to claim 2, wherein the on-off valve is switched to an open position by a constant pitch signal from the rotation angle detector. When each opening hole overlaps the auxiliary port at a certain time interval, the means for temporarily opening the opening / closing valve causes the rotation movement of the operating shaft of the movable plate to act on the opening / closing valve, and the power of the operating shaft The vacuum packaging machine apparatus according to claim 2 or 3, wherein the on-off valve is configured to be switched to an open position.

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