JP7709264B2 - vacuum packaging machine - Google Patents

Description

The present invention relates to a vacuum packaging machine that uses a vacuum pump to evacuate the inside of a chamber to create a negative pressure, and then uses a sealing device to seal the opening edge of a packaging bag contained in the chamber, thereby sealing the inside of the packaging bag in a deaerated state.

Patent Document 1 below discloses a vacuum packaging machine that vacuum packages packaging bags containing food ingredients, cooked foods, and other packaged items. This vacuum packaging machine includes a chamber that is provided on the top of a casing and forms an airtight space inside to accommodate the packaging bag, a sealing device that is provided inside the chamber and seals the opening periphery of the packaging bag by heat welding, and a vacuum pump at the bottom of the casing that degass the chamber to create a negative pressure. The chamber includes a shallow box-shaped chamber base with an open top, and a plate-shaped chamber cover that covers the top of the chamber base and can be opened and closed freely. The sealing device includes a lower block that is provided on the chamber base so as to be movable up and down, an upper block that is provided on the underside of the chamber cover, a heater that is provided on the top surface of the lower block, and a lifting mechanism that lifts and lowers the lower block.

When vacuum packaging a packaging bag with this vacuum packaging machine, the packaging bag is laid flat on the chamber base so that the opening periphery of the packaging bag rests on the upper side of the lower block, and the top opening of the chamber base is closed with the chamber cover, after which the vacuum packaging program is executed. When the vacuum packaging program is executed, the chamber is degassed by the vacuum pump until a specified vacuum level is reached, and the packaging bag in the chamber is also degassed. The degassed packaging bag is welded by heating with a heater while the opening periphery is sandwiched between the lower and upper blocks, and the packaging bag is sealed in a degassed state.

JP 2016-150757 A

The above vacuum packaging machine is mainly used to vacuum package packaging bags containing low-height packaged items such as cut vegetables and other foods, and cooked foods such as stew. When using this vacuum packaging machine to vacuum package a high-height packaged item such as a block of meat, the upper side of the chamber base cannot be closed with the chamber cover. In response to this, by deepening the depth of the chamber base or by making the chamber cover box-shaped like the chamber base and arranging them facing each other with their openings facing each other to deepen the depth of the chamber, it is possible to accommodate a packaging bag containing a high-height packaged item such as a block of meat in the chamber. However, if the overall depth of the chamber is deepened, the volume of the chamber becomes excessively large compared to the packaging bag, and it takes longer to degas the chamber with a vacuum pump to create a negative pressure, and more energy is consumed to degas the chamber and create a negative pressure. The present invention aims to prevent the volume of the chamber from becoming excessively large compared to the packaging bag, even if a packaging bag containing a high-height packaged item can be accommodated in the chamber.

In order to solve the above problems, the present invention provides a chamber in which an enclosed space for accommodating a packaging bag is formed by covering the upper side of a chamber base with a chamber cover having a packing provided on the peripheral edge of the lower surface so as to be able to be opened and closed freely, a sealing device provided within the chamber for sealing the peripheral edge of the opening of the packaging bag to seal the packaging bag, and a vacuum pump for evacuating the enclosed space within the chamber to create a negative pressure, the sealing device being provided on one horizontal side of the chamber and comprising upper and lower blocks extending with a second direction as its longitudinal direction that is perpendicular to a first direction connecting the one side and the other horizontal side, The present invention provides a vacuum packaging machine in which the opening peripheral portion of the packaging bag is sealed while being sandwiched above and below by these upper and lower blocks, and the chamber cover is characterized in that it has a protruding portion whose central portion in the second direction protrudes upward and extends from one end to the other end in the first direction, and flat portions having a flat shape extending from one end to the other end in the first direction on both sides of the protruding portion in the second direction, inside the portion for sealing with a gasket provided on both sides in the second direction , to reduce the volume inside the chamber .

In the vacuum packaging machine configured as described above, a packaging bag containing a tall packaged item is pulled in the height direction, and therefore becomes shorter in the second direction than a packaging bag containing a short packaged item. In order to reliably seal the peripheral edge of the opening of the packaging bag, the packaging bag is placed in the center in the second direction, which is the longitudinal direction of the lower block, and the tall packaged item in the packaging bag is also placed in the center in the second direction. The chamber cover protrudes upwards at its center in the second direction, where a packaging bag containing a tall packaged item is placed, so that the protrusion extends from one end to the other end in the first direction, so that not only can a packaging bag containing a tall packaged item be accommodated in the chamber, but also, even if a packaging bag containing a tall packaged item is accommodated in the chamber, flat parts having a flat shape extending from one end to the other end in the first direction on both sides of the protrusion in the second direction inside the parts for sealing with packing provided on both sides in the second direction to reduce the volume inside the chamber are provided, so that an increase in the volume on both sides of the protrusion in the second direction, where a packaging bag is difficult to place, is suppressed, and the volume inside the chamber is prevented from becoming excessively large relative to the packaging bag. This makes it possible to suppress the time required for the vacuum pump to evacuate the chamber to create a negative pressure, and also suppresses the energy consumption for evacuating and creating a negative pressure.

In the vacuum packaging machine configured as described above , the chamber cover is configured with a surface divided into a protruding portion, a flat portion, and a rising portion, so that when the chamber is deaerated to create a negative pressure, the chamber cover is less likely to deform, and the concentration of stress generated in each portion of the chamber cover can be suppressed. In this case, it is preferable that the rising portion is an inclined surface that rises obliquely while approaching the protruding portion from the flat portion. In this case, even if a packaging bag containing a tall packaged item is placed at a position shifted from the center of the chamber base in the second direction, the packaging bag is pushed by the rising portion consisting of the inclined surface and positioned at the center in the second direction, and the tall packaged item in the packaging bag is positioned at a position where it does not hit the chamber cover.

In the vacuum packaging machine configured as described above, when a tall packaged item is placed in the packaging bag, in order to prevent wrinkles from forming around the opening edge of the packaging bag, the packaged item is placed on the bottom side of the packaging bag as far away as possible from the opening of the packaging bag, and the packaged item is placed on the other side side of the chamber away from one side where the lower block is placed. Also, even if a tall packaged item is stored on the bottom side of the opening of the packaging bag, the packaging bag is pulled in the height direction, so that the packaged item in the packaging bag is unlikely to be placed on the other side in the first direction. Therefore, when a packaging bag containing a tall packaged item is placed in the chamber, the packaged item is placed in the middle part of the one side and the other side in the chamber. The protruding part of the chamber cover is formed so that the middle part between the one side and the other side is the highest, and the position where the tall packaged item is placed in the packaging bag is the highest, so that even if a packaging bag containing a tall packaged item can be stored in the chamber, the volume of the chamber does not become excessively large compared to the packaging bag.

FIG. 2 is a perspective view of the vacuum packaging machine of the present embodiment. FIG. 2 is a perspective view of the state in which the chamber cover of FIG. 1 is opened. A cross-sectional view taken along line A-A. B-B cross-sectional view. FIG. 1 is a schematic diagram of a vacuum packaging machine. FIG. 2 is a block diagram of a control device. 1 is a flowchart of a packaging program.

An embodiment of the vacuum packaging machine of the present invention will be described below with reference to the attached drawings. As shown in Figs. 1 to 4, the vacuum packaging machine 10 of the present invention has a chamber cover 22 with a central portion in the left-right direction that bulges upward, so that a packaging bag containing a tall packaged item such as a block of meat can be accommodated in the chamber 20. The vacuum packaging machine 10 includes a chamber 20 provided in the upper part of the casing 11, a sealing device 30 that seals the opening edge of the packaging bag in the chamber 20, and a vacuum pump 40 that degass the chamber 20 to create a negative pressure in the lower part of the casing 11 that is the lower side of the chamber 20. In the following description, one side of the chamber 20 described in the claims is the front (front side), the other side is the rear (rear side), the first direction is the front-rear direction connecting the front and rear, and the second direction perpendicular to the first direction and the horizontal direction is the left-right direction.

As shown in Figures 1 to 4, the casing 11 has a generally rectangular parallelepiped shape, and a chamber 20 is provided at the top of the casing 11. The chamber 20 includes a chamber base 21 and a chamber cover 22 provided at the top of the casing 11, and the upper side of the chamber base 21 is closed by the chamber cover 22 in a freely openable and closable manner, thereby forming an airtight space for accommodating a packaging bag inside.

As shown in FIG. 2, the chamber base 21 is a shallow box with an open top and is formed by pressing a sheet metal member such as stainless steel. As shown in FIG. 3, a step 21a is formed in the front of the chamber base 21, which is shallower than the other parts, and a lower block 31 that constitutes the sealing device 30 is provided above the step 21a so that it can move up and down.

As shown in FIG. 4, the chamber base 21, except for the step 21a, is curved so that the center in the left-right direction is the lowest, and the packaging bag to be stored in the chamber 20 is easily placed in the center in the left-right direction, which is the lowest. By placing the packaging bag in the center in the left-right direction within the chamber 20, the opening edge of the packaging bag is placed on the center in the left-right direction of the lower block 31. Furthermore, when a tall packaged item such as a block of meat is placed in the packaging bag, the packaged item in the packaging bag is placed in the middle in the front-to-rear direction, away from the lower block 31, which is located at the front of the chamber 20, to prevent wrinkles from forming on the opening edge of the packaging bag.

As shown in Figures 1 and 2, the chamber cover 22 is a lid made of a pressure-resistant acrylic material that can be freely opened and closed to cover the top opening of the chamber base 21, and forms an airtight space between the chamber cover 22 and the chamber base 21 to accommodate packaging bags. The rear end of the chamber cover 22 is supported on the rear end of the casing 11 so as to be rotatable about a horizontal axis, and the front part of the chamber cover 22 can be rotated up and down. As shown in Figure 1, when the chamber cover 22 is in a horizontal position, it is in a closed position that closes the top opening of the chamber base 21. As shown in Figure 2, when the front part of the chamber cover 22 is rotated upward, the chamber cover 22 becomes an inclined position and becomes an open position that opens the top surface of the chamber base 21.

As shown in Figures 2 and 3, a gas spring 12 is provided at the rear of the casing 11, and the gas spring 12 urges the front of the chamber cover 22 upward, urging the chamber cover 22 to an open position where it is released from the chamber base 21. As shown in Figures 2 to 4, a rubber packing 23 is provided as a sealing member around the periphery of the underside of the chamber cover 22, and the packing 23 provides an airtight seal between the chamber base 21 and the chamber cover 22 when the chamber cover 22 is closed to the closed position.

1 and 3, the chamber cover 22 has flat portions 22a in the shape of a flat plate on both sides in the left-right direction, and a protruding portion 22b in the left-right center that protrudes upward. A rising portion 22c rising from the flat portion 22a to the protruding portion 22b is formed between the flat portion 22a and the protruding portion 22b. The lower surface of the flat portion 22a is at a height that abuts against the upper edge of the chamber base 21, and covers both left and right sides of the chamber base 21. The packaging bag contained in the chamber 20 is easily placed in the left-right center due to the curved surface of the bottom wall of the chamber base 21, and when a packaging bag containing a tall packaged item is placed in the left-right center of the chamber base 21, the tall packaged item in the packaging bag is unlikely to be placed above the flat portion 22a of the chamber cover 22. In this way, the flat portion 22a is located in a position where it is difficult to place tall packed items inside the packaging bag, and has the function of preventing excess space from being formed on both the left and right sides of the chamber 20.

As shown in FIG. 3, the rising portion 22c is an inclined surface that slopes obliquely upward as it approaches the protruding portion 22b from the flat portion 22a, and the rising portion 22c made of an inclined surface has the function of positioning the packaged item in a tall packaging bag placed on the chamber base 21 in the center in the left-right direction. Note that the rising portion 22c is not limited to being an inclined surface that rises upward as it approaches the protruding portion 22b from the flat portion 22a, and may be made to stand vertically, although this would make it difficult to position the tall packaged item in the center.

As shown in Figures 1 and 4, the protrusion 22b of the chamber cover 22 has the function of making it difficult for a packaging bag containing a tall packaged item to hit the chamber cover 22 when the packaging bag is placed in the center of the left-right direction of the chamber base 21. The left-right length of the protrusion 22b of the chamber cover 22 is approximately 1/2 the width (left-right length) of the chamber cover 22. The packaging bag contained in the chamber 20 is easily placed in the center of the left-right direction, and when a packaging bag containing a tall packaged item is placed in the center of the left-right direction of the chamber base 21, the protrusion 22b of the chamber cover 22 can accommodate the packaging bag containing the tall packaged item.

As shown in Figures 1 and 3, the protrusion 22b rises from the front end slightly rearward of the center in the fore-and-aft direction, and then descends from slightly rearward of the center in the fore-and-aft direction to the rear end, so that the height of the middle part in the fore-and-aft direction (slightly rearward of the center in the fore-and-aft direction) is the highest.

When a packaging bag containing a tall packaged item is placed in the chamber 20, the packaged item is placed at the bottom of the packaging bag as far away from the opening of the packaging bag as possible to prevent wrinkles from forming around the opening edge of the packaging bag, and the tall packaged item is placed at the rear (the other side) of the chamber 20, away from the front (one side) of the chamber 20 where the lower block 31 is placed. Also, even if a tall packaged item is placed at the bottom side of the opening of the packaging bag, the packaging bag is pulled in the height direction, so the packaged item in the packaging bag is not placed at the rear (the other side in the first direction) of the chamber 20. Therefore, when a packaging bag containing a tall packaged item is placed in the chamber 20, the packaged item is placed in the middle of the front-to-rear direction (the middle part between one and the other side) in the chamber 20.

The protruding portion 22b of the chamber cover 22 is formed so that the middle portion in the front-to-rear direction of the chamber 20, where tall packaged items are likely to be placed in the packaging bag, is the highest. This makes it possible to accommodate a packaging bag containing a tall packaged item in the chamber 20 without the volume of the chamber 20 becoming excessively large compared to the packaging bag.

As shown in Figures 2 and 4, a gas spring 12 is provided at the rear end of the casing 11, and the gas spring 12 urges upward the front of the chamber cover 22, which is supported at the rear of the casing 11 so as to be rotatable about a horizontal axis. A stopper 13 is provided at the front end of the right side of the casing 11 so as to be rotatable about a horizontal axis, and the stopper 13 engages with the front upper surface of the chamber cover 22 to hold the chamber cover 22 in a position that blocks the top opening of the chamber base 21.

As shown in FIG. 5, a cover detector 14 that detects the closed state of the chamber cover 22 is provided at the rear of the casing 11. The cover detector 14 is a proximity switch such as a reed switch, and a magnet 15 that allows the cover detector 14 to detect the closed state of the chamber cover 22 is provided at the rear of the chamber cover 22. When the chamber cover 22 is in a closed position that blocks the top opening of the chamber base 21, the magnet 15 approaches the cover detector 14, and the cover detector 14 outputs an ON signal. When the chamber cover 22 is in an open position that opens the top opening of the chamber base 21, the magnet 15 moves away from the cover detector 14, and the cover detector 14 outputs an OFF signal.

As shown in Figures 3 and 5, a sealing device 30 is provided at the front (one horizontal side) of the chamber 20. The sealing device 30 seals the opening edge of the packaging bag contained in the chamber 20 by heat welding to seal the packaging bag. The sealing device 30 is equipped with lower and upper blocks 31, 32 that hold the opening edge of the packaging bag. The lower block 31 is made of an aluminum square pipe member and is supported on the upper side of the step portion 21a of the chamber base 21 so that it can be detached and moved up and down. A band-shaped heater 33 made of nichrome material is provided on the upper surface of the lower block 31. The upper block 32 is made of an elastically deformable silicon block body and is attached to the front of the lower surface of the chamber cover 22 at a position facing the upper side of the lower block 31.

As shown in Figures 3 and 5, a pair of left and right lifting mechanisms 34 for lifting the lower block 31 up and down are provided on the underside of the step 21a of the chamber base 21. Each lifting mechanism 34 has a support shaft 35 that penetrates the bottom wall of the step 21a of the chamber base 21, and a lifting cylinder 36 that moves the support shaft 35 up and down. As shown in Figure 5, a flange 37 is provided in the axial middle of the support shaft 35, and the flange 37 airtightly divides the inside of the lifting cylinder 36 into an upper space 36a and a lower space 36b. A spring member 38 is interposed around the outer periphery of the support shaft 35 in the upper space 36a of the lifting cylinder 36, and the spring member 38 urges the support shaft 35 downward via the flange 37.

As shown in FIG. 5, a vacuum pump 40 is provided at the bottom of the casing 11. The vacuum pump 40 mainly sucks the inside of the chamber 20, exhausting the air in the sealed space inside the chamber 20 and creating a negative pressure inside the chamber 20. A suction pipe (suction path) 41 that connects the vacuum pump 40 and the chamber 20 is provided inside the casing 11, and a vacuum valve 42 is installed in the suction pipe 41. The air inside the chamber 20 can be sucked into the vacuum pump 40 by opening the vacuum valve 42.

An outside air introduction pipe 43 that introduces outside air between the chamber 20 and the vacuum valve 42 is connected to the suction pipe 41, and the outside air introduction pipe 43 has a first pipe section 43a and a second pipe section 43b branching off from the first pipe section 43a. The first and second pipe sections 43a, 43b are fitted with first and second outside air introduction valves 44, 45 that open and close them. The first outside air introduction valve 44 is formed with a larger valve diameter than the second outside air introduction valve 45, so that when the first outside air introduction valve 44 is opened, outside air is introduced into the chamber 20 quickly, and when the second outside air introduction valve 45 is opened, outside air is introduced into the chamber 20 slowly.

A pressure detection tube 46 is connected to the suction tube 41 via the first tube section 43a of the outside air introduction tube 43, and a vacuum gauge 47 is provided on the pressure detection tube 46 to detect the pressure in the chamber 20. When the chamber 20 is not evacuated by the vacuum pump 40, the pressure in the chamber 20 detected by the vacuum gauge 47 is 100 kPa (abs), which is the same as atmospheric pressure, and the degree of vacuum at this time is 0%. When the chamber 20 is evacuated by the vacuum pump 40 to create a negative pressure and the pressure in the chamber detected by the vacuum gauge 47 is 0 kPa (abs), the degree of vacuum is 100%. Note that the pressure in the chamber 20 is directly detected by the vacuum gauge 47, but in the following explanation, the pressure detected by the vacuum gauge 47 will be replaced with the degree of vacuum P in the chamber 20.

A cylinder pipe 48 branches off from the suction pipe 41 between the vacuum pump 40 and the vacuum valve 42, and the cylinder pipe 48 is connected to the upper space 36a of the lift cylinder 36. A three-way valve 49 is interposed in the cylinder pipe 48, and two ports of the three-way valve 49 are connected to the vacuum pump 40 side and the lift cylinder 36 side of the cylinder pipe 48, and the remaining port of the three-way valve 49 is open to the outside air side. When the vacuum pump 40 side and the lift cylinder 36 side of the three-way valve 49 are in communication with each other, the upper space 36a of the lift cylinder 36 is negatively pressurized, and the support shaft 35 rises against the biasing force of the spring member 38. When the lift cylinder 36 side of the three-way valve 49 is in communication with the outside air side, the upper space 36a of the lift cylinder 36 is not negatively pressurized, and the support shaft 35 is lowered by the biasing force of the spring member 38.

As shown in Figures 3 and 5, a bulge detection unit 50 that detects the bulge of the package bag contained within the chamber 20 is provided. The bulge detection unit 50 includes a detection plate 51 supported rotatably about a horizontal axis on the front part of the lower surface of the chamber cover 22, a magnet 52 fixed to the rear end of the detection plate 51, and a bulge detector 53 consisting of a proximity switch such as a reed switch that detects the position of the detection plate 51.

The detection plate 51 has a strip shape extending in the second direction, similar to the lower and upper blocks 31 and 32. The detection plate 51 is disposed immediately behind the upper block 32 on the lower surface of the chamber cover 22, and is supported so as to be rotatable about a horizontal axis so that the rear side can move up and down. A magnet 52 is fixed to the rear end of the left end of the detection plate 51, and the magnet 52 moves up and down by the rotation of the detection plate 51. When the packaging bag contained in the chamber 20 is not inflated, the detection plate 51 is inclined diagonally downward, and the magnet 52 at the rear end of the detection plate 51 is located at the bottom (lower position) in the chamber 20 (shown by solid lines in Figures 3 and 5). When the packaging bag contained in the chamber 20 is inflated, the detection plate 51 is lifted up by the inflated packaging bag and rotates, and the magnet 52 at the rear end of the detection plate 51 is located at the top (upper position) in the chamber 20 (shown by two-dot chain lines in Figures 3 and 5).

The bulge detector 53 detects the bulge of the packaging bag by detecting the position of the magnet 52 at the rear end of the detection plate 51, which rotates upward when the packaging bag bulges. The bulge detector 53 is disposed in a position facing the magnet 52 of the detection plate 51 in the upper position on the outside of the chamber base 21. When the packaging bag is not bulging and the magnet 52 of the detection plate 51 is in the lower position, the bulge detector 53 outputs an OFF signal as the magnet 52 in the lower position is separated. When the packaging bag is bulging and the magnet 52 of the detection plate 51 is in the upper position, the bulge detector 53 outputs an ON signal as the magnet 52 in the upper position approaches.

The vacuum packaging machine 10 is equipped with a control device 60, which is connected to the cover detector 14, the heater 33, the vacuum pump 40, the vacuum valve 42, the first and second outside air introduction valves 44, 45, the vacuum gauge 47, the three-way valve 49, the bulge detector 53, and an operation panel 61 provided on the front of the casing 11, as shown in FIG. 6. The control device 60 has a microcomputer (not shown), which has a CPU, RAM, ROM, and a timer (all not shown) connected to each other via a bus.

The control device 60 has a packaging program in its ROM that seals the packaging bag in a deaerated state. The packaging program is a program for creating a negative pressure in the chamber 20 to a predetermined pressure using the vacuum pump 40, deaerating the packaging bag contained in the chamber 20, and then sealing the opening edge of the packaging bag with the sealing device 30, thereby sealing the packaging bag in a deaerated state.

The packaging program is set with different programs for the degree of vacuum in the chamber 20 and the manner of opening the first and second outside air introduction valves 44, 45 depending on the temperature of the food to be put into the packaging bag. As an example of a packaging program, a packaging program when the food is at room temperature (low temperature) will be specifically described. Before the packaging program is executed, the vacuum valve 42 and the second outside air introduction valve 45 are closed, and the lifting cylinder 36 side of the three-way valve 49 is connected to the outside air side (the vacuum pump 40 side is closed). The food to be packaged, such as ingredients or food, is placed in the packaging bag, and the packaging bag is placed in the chamber 20 so that the opening periphery of the packaging bag is placed on the upper side of the lower block 31. The operation panel 61 is operated to select a packaging program when the food is at room temperature, and the selected packaging program is put on hold for execution.

As shown in FIG. 7, in step 101, the control device 60 determines whether the chamber cover 22 is closed by determining whether an ON signal has been input from the cover detector 14. When the chamber cover 22 is not closed, the magnet 15 is not close to the cover detector 14, so the cover detector 14 outputs an OFF signal to the control device 60, and the control device 60 waits by repeatedly determining "NO" in step 101. When the chamber cover 22 is closed and the magnet 15 approaches the cover detector 14, the cover detector 14 outputs an ON signal to the control device 60, and the control device 60 determines "YES" in step 101 and proceeds to step 102. In step 102, the control device 60 opens the vacuum valve 42, closes the first outside air introduction valve 44, and operates the vacuum pump 40, and the chamber 20 is degassed by the vacuum pump 40 to create a negative pressure.

In step 103, the control device 60 repeatedly determines whether the degree of vacuum P in the chamber 20 detected by the vacuum gauge 47 has reached or exceeded the preset vacuum Px (or reached or exceeded the specified pressure). When the pressure in the chamber 20 gradually decreases and the degree of vacuum P in the chamber 20 detected by the vacuum gauge 47 reaches or exceeded the preset vacuum Px (or reached or exceeded the specified pressure), the control device 60 determines "YES" in step 103 and proceeds to step 104. In step 104, the control device 60 closes the vacuum valve 42 to stop degassing the chamber 20 and proceeds to step 105.

When the pressure inside the chamber 20 reaches a vacuum level equal to or higher than the predetermined pressure Px (or equal to or lower than the predetermined pressure) and the packaging bag is degassed, the control device 60 communicates the lift cylinder 36 side and the vacuum pump 40 side of the three-way valve 49 in step 105 (the outside air side is closed). The upper space 36a of the lift cylinder 36 is negatively pressurized by the vacuum pump 40, the support shaft 35 rises against the biasing force of the spring member 38, and the lower block 31 rises due to the rising support shaft 35. The lower block 31 is pressed against the upper block 32 by the rising support shaft 35, and the opening edge of the packaging bag is clamped between the lower block 31 and the upper block 32. In step 106, the control device 60 energizes the heater 33 to generate heat, and the opening edge of the packaging bag is closed by thermal welding, and the packaging bag is sealed in a degassed state (vacuum state).

In step 107, the control device 60 stops the operation of the vacuum pump 40 and opens the first outside air introduction valve 44, and in step 108, the lift cylinder 36 side of the three-way valve 49 communicates with the outside air side (the vacuum pump 40 side is closed). The inside of the chamber 20 is returned to atmospheric pressure by the outside air introduced from the first outside air introduction valve 44, and the chamber cover 22 is opened by the biasing force of the gas spring 12 without being sucked by negative pressure. In addition, by opening the lift cylinder 36 side and the outside air side of the three-way valve 49, outside air is introduced into the upper space 36a of the lift cylinder 36, and the negative pressure state is released, the support shaft 35 is lowered by the biasing force of the spring member 38, the lower block 31 is separated from the upper block 32, and the state in which the opening edge of the packaging bag is clamped by the lower and upper blocks 31 and 32 is released. In this way, the packaging bag is sealed in a degassed state (vacuum state).

The vacuum packaging machine 10 configured as described above is capable of vacuum packaging a packaging bag containing a tall packaged item such as a block of meat. A packaging bag containing a tall packaged item such as a block of meat is pulled in the height direction, so it becomes shorter in the left-right direction (second direction), which is the width direction, than a packaging bag containing a short packaged item. In order to reliably seal the opening periphery of the packaging bag, the packaging bag is placed in the center in the left-right direction (second direction), which is the longitudinal direction of the lower block 31, and the tall packaged item inside the packaging bag is also placed in the center in the left-right direction (second direction) inside the chamber 20.

In this vacuum packaging machine 10, the chamber cover 22 has a central portion in the left-right direction (second direction) where a packaging bag containing a tall packaged item is placed, and the central portion protrudes upward by a protruding portion 22b. In this embodiment, the chamber cover 22 has a flat portion 22a having a flat shape on both sides of the protruding portion 22b in the left-right direction (second direction), and a rising portion 22c rising from the flat portion 22a to the protruding portion 22b. This makes it possible to accommodate a packaging bag containing a tall packaged item in the chamber 20, but prevents the volume of the chamber 20 from becoming excessively large compared to the packaging bag, and prevents the time required for the vacuum pump 40 to evacuate the chamber 20 to create a negative pressure from becoming long, and also reduces the energy consumption required for evacuating the chamber 20 to create a negative pressure.

In addition, since the chamber cover 22 is composed of a protruding portion 22b, a flat portion 22a, and a rising portion 22c, when the chamber 20 is evacuated to create a negative pressure, the chamber cover 22 is less likely to deform, and the concentration of stress in each portion of the chamber cover 22 can be suppressed.

The rising portion 22c is an inclined surface that rises and slopes diagonally as it approaches the protruding portion 22b from the flat portion 22a. As a result, even if a packaging bag containing a tall packaged item is placed in a position that is offset from the center of the chamber base 21 in the left-right direction (second direction), the packaging bag is pushed by the rising portion 22c, which is an inclined surface, and positioned below the protruding portion 22b in the center of the left-right direction (second direction), so that the packaging bag is positioned in a position where it does not hit the chamber cover 22.

The protrusion 22b of the chamber cover 22 is formed so that the height of the front-to-rear middle part (the middle part between one side part and the other side part) is the highest. Since a tall packaged item is stored on the bottom side of the opening of the packaging bag, when the packaging bag is stored in the chamber 20 with the opening periphery placed on the lower block 31, the tall packaged item in the packaging bag will be positioned in the front-to-rear middle part (the middle part between one side part and the other side part) of the lower block 31 on which the opening periphery of the packaging bag is placed. By making the position where the tall packaged item in the packaging bag is positioned the highest, it is possible to store a packaging bag containing a tall packaged item in the chamber 20 without the volume of the chamber 20 becoming excessively large compared to the packaging bag.

In the vacuum packaging machine 10 configured as described above, the sealing device 30 is provided at the front as one of the horizontal sides of the chamber 20, and is provided with lower and upper blocks 31, 32 that extend in the left-right direction (second direction) perpendicular to the front-to-rear direction (first direction connecting one side and the other side) and the horizontal direction as their longitudinal directions, but this is not limited to the above, and the sealing device 30 may be provided at the rear as one of the horizontal sides of the chamber 20, and with lower and upper blocks 31, 32 that extend in the left-to-right direction (second direction) perpendicular to the front-to-rear direction (first direction connecting one side and the other side) and the horizontal direction as their longitudinal directions.

Similarly, the sealing device 30 may be provided on the left or right side as one of the horizontal sides of the chamber 20, and may include lower and upper blocks 31, 32 that extend in the longitudinal direction in a front-to-rear direction (second direction) perpendicular to the left-to-right direction (first direction connecting one side and the other side) and the horizontal direction. In this case, the chamber cover 22 may be provided with a protrusion 22b that protrudes upward at the center in the front-to-rear direction (second direction).

In the vacuum packaging machine 10 configured as described above, the chamber base 21 is a shallow box-shaped opening at the top, and the chamber cover 22 closes the top opening of the chamber base 21, but the present invention is not limited to this. The chamber base 21 may be a flat plate, the chamber cover 22 may be a shallow box-shaped opening at the bottom, and the center of the shallow box-shaped opening at the bottom in the second direction may be a protrusion 22b that protrudes upward.

10...vacuum packaging machine, 11...casing, 20...chamber, 21...chamber base, 22 chamber cover, 22a...flat portion, 22b...protruding portion, 22c...rising portion, 30...sealing device, 31...lower block, 32...upper block, 40...vacuum pump.

Claims (4)

a chamber having an upper side of a chamber base covered by a chamber cover having a packing on a lower peripheral edge portion thereof so as to be freely opened and closed, thereby forming an enclosed space for accommodating a packaging bag therein;
a sealing device provided in the chamber for sealing an opening peripheral portion of the packaging bag to hermetically seal the packaging bag;
a vacuum pump that evacuates the sealed space in the chamber to create a negative pressure;
The sealing device is provided on one side of the chamber in the horizontal direction, and includes upper and lower blocks extending in a first direction connecting the one side and the other side and a second direction perpendicular to the horizontal direction, and the upper and lower blocks sandwich the opening edge of the packaging bag from above and below to seal the opening edge of the packaging bag,
A vacuum packaging machine characterized in that the chamber cover has a protruding portion whose central portion in the second direction protrudes upward and extends from one end to the other end in the first direction, and a flat portion having a flat shape extending from one end to the other end in the first direction on both sides of the protruding portion in the second direction, inside the portion for sealing with the gasket provided on both sides in the second direction, to reduce the volume within the chamber . In the vacuum packaging machine according to claim 1,
The chamber cover has a rising portion that rises from the flat portion to the protruding portion. In the vacuum packaging machine according to claim 2,
The vacuum packaging machine according to claim 1, wherein the rising portion is an inclined surface that rises obliquely as it approaches the protruding portion from the flat portion. In the vacuum packaging machine according to any one of claims 1 to 3,
The vacuum packaging machine according to claim 1, wherein the protrusion is formed so that a middle portion between the one side and the other side is highest.