Packaging equipment

Abstract

To solve, in a packaging apparatus, a problem caused in a packaging process by trouble that an article to be packaged sticks to a welded area as it is when an entire portion to be welded is brought into contact with a heat generating portion to process at once.SOLUTION: A seal packaging apparatus that stretches a film to weld the film onto an edge portion of a tray using a heater includes a heater section that welds the film onto the edge portion of the tray, a tray holding section that holds the tray, and a peeling section that prevents sticking against the heater section.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a packaging device that covers a tray on which an object to be packaged is placed with a film and heat-seals the film to the edge of the tray.

Background Art

[0002] As a conventional packaging device, there is one that improves convenience by placing an object to be packaged on a mounting table, pushing it into the machine body, and configuring the mounting table to be automatically pushed out of the machine body by an unloading mechanism after heat-sealing (see, for example, Patent Document 1).

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The packaging device described in Patent Document 1 has a drawback in that it takes a long time for one process because heat-sealing is performed by rotating a heating roller. Although it is conceivable to remove the heating roller and bring the entire welding portion into contact with the heating portion for processing at once, there is a possibility that the object to be packaged will stick to the welding portion as it is, which will rather hinder the packaging process.

Means for Solving the Problems

[0005] The packaging device of the present invention comprises at least the following configuration. A packaging device that stretches a film and welds the film to the edge of the tray with a heater, comprising a heater unit that welds the film to the edge of the tray, and a tray holding unit that holds the tray. The system comprises a film feed section for stretching the film and a control section, wherein the film feed section functions as a release section to prevent the film from sticking to the heater section, the control section restarts the film feed section from the stop position where the film has been gripped and stretched to contact the tray, the tray holding section pushes the tray up to contact the heater section, and the control section can restart the film feed section to contact the tray after stopping the tray holding section at a predetermined position. Characterized by the above.

Effects of the Invention

[0006] According to the present invention, it is possible to provide a packaging apparatus that can properly perform the packaging process. [Brief explanation of the drawing]

[0007] [Figure 1] A perspective view showing the external appearance of a packaging device according to an embodiment of the present invention. [Figure 2] A top view showing the external appearance of a packaging device according to an embodiment of the present invention. [Figure 3] A perspective view showing the interior of a packaging device according to an embodiment of the present invention, with the casing removed. [Figure 4] This is a left side view showing the interior of a packaging device according to an embodiment of the present invention with the housing removed, where (a) shows the case when a large-sized tray is used and (b) shows the case when a small-sized tray is used. [Figure 5] This is a left side view illustrating the push-up operation of the tray push-up section of a packaging device according to an embodiment of the present invention, where (a) shows the tray push-up section in its initial position, which is at the lowest level, (b) shows it in the middle level, and (c) shows it in the uppermost level. [Figure 6] This is a left side view illustrating the control to prevent tray from sticking to the heater section as a peeling section of a packaging device according to an embodiment of the present invention, where (a) shows the film feed section picking up the film, (b) shows the film being pulled out and heat-sealed, and (c) shows the state immediately after the completion of heat sealing. [Figure 7] This is a photograph showing the actual state immediately after the heat sealing process is complete. [Figure 8] Photographs and diagrams illustrating the structure and operation of another example of the peeling section of a packaging device according to an embodiment of the present invention. [Figure 9] A perspective view showing the tray pushing section and discharge section of a packaging apparatus according to an embodiment of the present invention. [Figure 10] A top view showing the tray pushing section and discharge section of a packaging apparatus according to an embodiment of the present invention. [Figure 11]A perspective view showing the tray pushing section and discharge section of a packaging device according to an embodiment of the present invention, the diagram showing how tray pushing sections of different sizes are loaded. [Figure 12] A top view showing the tray pushing section and discharge section of a packaging device according to an embodiment of the present invention, the diagram showing how tray pushing sections of different sizes are loaded. [Figure 13] A diagram illustrating the terminal pattern of the heating element of a packaging device according to an embodiment of the invention. [Figure 14] A diagram illustrating another terminal pattern for the heating element of a packaging device according to an embodiment of the invention. [Modes for carrying out the invention]

[0008] The following describes an example of an embodiment of the packaging apparatus according to the present invention, based on the drawings. However, the following drawings are created for illustrative purposes, and in order to make them easier to understand, some components that are not necessary for the explanation may be intentionally omitted. Also, components may be intentionally shown larger or smaller for illustrative purposes, and the drawings do not represent an accurate scale. In the following description, the same reference numerals in different figures indicate parts with the same function, and redundant explanations in each figure will be omitted as appropriate.

[0009] (Overall structure) Figures 1 and 2 show the external appearance of a packaging device according to an embodiment of the present invention, where Figure 1 is a perspective view and Figure 2 is a top view. Figure 3 is a perspective view showing the interior of the packaging device with the housing removed, and Figure 4 is a left side view showing the interior of the packaging device with the housing removed, where (a) shows the case when a large-sized tray is used and (b) shows the case when a small-sized tray is used.

[0010] The packaging apparatus 100 according to the embodiment of the present invention shown in Figures 1 and 2 automatically performs a series of operations from loading a tray T on which the items to be packaged are placed into the machine to performing heat sealing and then unloading the tray. More specifically, as shown by the arrows in Figure 2, when the packaging apparatus 100 places a tray T on which the items to be packaged are placed into the loading section 1, the tray T is loaded into the machine having a heater section 2, and the tray T is pushed upward inside the machine so that its edge contacts a film stretched at an upper position inside the machine, and the film is heat-sealed to seal the packaging. After that, the tray T is moved in an unloading direction perpendicular to the loading direction and discharged to the first discharge platform 3, and then the tray T is moved in the opposite direction to the loading direction and sent to the second discharge platform 4. In this embodiment of the present invention, it is possible to handle two types of trays T of different sizes, large and small. Note that the edge does not have to be the entire edge of the tray, but may be the end of the tray, which is a part of the edge, as long as appropriate packaging processing can be performed.

[0011] The placement unit 1 functions as a scale and is configured to measure the weight of the packaged item and the tray T placed thereon. The placement unit 1 is provided with a loading and transfer unit 11 having two endless belts 111, 111, and is configured to be able to load the tray T placed thereon into the machine having the heater unit 2. More specifically, as shown in FIGS. 3 and 4, the loading and transfer unit 11 is composed of two endless belts 111, 111 having claws 112, 112 on their circumferential surfaces, and the claws 112, 112 push the edge of the tray T, causing the tray T to move in the loading direction. In FIGS. 3 and FIGS. 4(a) and (b), two claws 112 (a total of four claws 112 in two rows in FIG. 3) are depicted as being close to each other along each endless belt, but this is for the purpose of making the movement of the claws 112 easier to understand. In reality, a total of two claws 112 (a total of four claws 112 in two rows) are positioned one by one at positions that have made a half turn of the endless belt 111. As the claws 112 rotate, the tray T is loaded into the machine having the heater unit 2. The claws 112 depicted to the left of the tray T in FIGS. 4(a) and (b) actually move promptly to a position where they do not interfere with the tray lifter 23 after the loading of the tray T into the machine is completed.

[0012] The tray T with heat sealing is transferred by the discharge unit 21 composed of drive rollers shown in FIG. 3 in the discharge direction orthogonal to the loading direction and discharged toward the first discharge table 3. The first discharge table 3 also has drive rollers and moves the tray T in the opposite direction of the loading direction and sends it to the second discharge table 4. The second discharge table 4 is inclined, and since the tray T moves by its own weight, the rollers of the second discharge table 4 are simple rollers without driving force. As shown in FIGS. 1 and 2, above the first discharge table 3, there is a console 5 having an operation unit such as a display unit, numeric keypad, touch panel, etc. on the front, a printing unit for label printing, and control means inside.

[0013] To summarize the interior of the apparatus having the heater unit 2, there are provided a tray pushing-up unit 23, a film feed unit 24 for pulling out the roll film R loaded in the apparatus so as to enable heat-sealing processing, a heating unit for performing heat-sealing processing, and a discharge unit 21 for discharging the packaged tray T after the heat-sealing processing is completed.

[0014] In the present embodiment, the roll film R is supported by passing a shaft through its center hole, but it may also be structured to be supported by four rollers that support four locations on the lower surface of the roll film R in a cantilever manner. The leading end of the drawn film is clamped by the film feed unit 24. From FIGS. 4(a) and (b), it is possible to confirm how the film feed unit 24 draws the film to different positions. Thus, the film feed unit 24 is configured to reciprocate in sections of different distances set according to the film size, and supplies a new film each time the heat-sealing processing is executed. The film clamping unit is configured to clamp the entire width in the width direction of the film, and since there is no portion where the film is not clamped, wrinkles do not occur when the film is fed.

[0015] A metal plate (heating element) as the heater unit 2 is disposed so as to face the drawn film. When the tray T is moved upward by the tray pushing-up unit 23, the film is heat-welded along the edge of the tray T in a state where the edge of the tray T and the film are sandwiched between the tray pushing-up unit 23 and the heater unit 2. As will be described later, the heater unit 2 has a structure in which a heat-resistant glass sheet is attached on the heating element, and the heating element has a pattern shape that can correspond to trays of different sizes.

[0016] (Operation of the tray pushing-up unit) Figure 5 is a left side view illustrating the operation of the tray pushing unit 23, but the heater unit 2 and film feed unit 24 are not shown. In Figure 5(a), both a tray T placed on the loading unit 1 being pushed by the claws 112 of the loading and transport unit 11 into the machine with the heater unit 2, and a tray T that has been loaded into the machine with the heater unit 2 are depicted for illustrative purposes. However, in reality, only one tray T exists, and a tray T in the process of being loaded and a tray T that has been loaded do not exist simultaneously. However, after the loading of a tray T into the machine is complete, it becomes possible to place a new tray T to be packaged next on the loading unit 1, so it is possible for a loaded tray T and a waiting tray T to exist simultaneously. In addition, a moving mechanism for raising and lowering the tray pushing unit 23 exists on the inner side plate of the housing, which is not shown in Figure 5, and the tray pushing unit 23 can be connected to (removed from) this moving mechanism. Furthermore, three proximity sensors are provided slightly above the upper end of the tray push-up section 23 shown in Figure 5(a), so that it is possible to detect whether the appropriate tray push-up section 23 is loaded at the initial stage of the tray push-up section 23 movement.

[0017] Figure 5(b) shows the tray push-up section 23 in the process of rising (or, as described later, in the process of descending). As the tray push-up section 23 rises, the tray T enters the rectangular frame of the tray push-up section 23. At this time, even if the force of transport by the claws 112 of the loading and transport section 11 is too strong and the tray T moves a little too much, causing it to be placed slightly outside the correct position, the sides of the tray T are sloped, so the position is corrected and the tray T naturally enters the tray push-up section 23.

[0018] Figure 5(c) shows the tray push-up section 23 rising further, pushing the tray T up to the position of the film feed section 24 (not shown). In this state, Figure 4(a) depicts the tray push-up section 23 and the heater section 2, with the tray push-up section 23 raised to approximately the same height as the film feed section 24. After heat sealing is performed by driving the heating element of the heater section 2, the tray T, having finished rising, is returned to its original position. That is, as shown in the sequence from Figure 5(c) to Figure 5(b), the tray push-up section 23 descends, and the tray T comes down together with the tray push-up section 23, and the discharge operation described later takes place.

[0019] (Function to prevent tray from sticking to the heater section) Figures 4(a) and 5 illustrate the processing of large-sized trays. In the case of large-sized trays, the volume and weight of the packaged items are of a certain size, so the tray T descends together with the tray push-up section 23. However, with regard to the processing of small-sized trays, as shown in Figure 4(b), because the packaged items are lightweight, the tray T sometimes sticks to the heater section 2, and even when the tray push-up section 23 descends, the tray T does not fall down.

[0020] Therefore, the packaging apparatus 100 according to an embodiment of the present invention addresses this problem by controlling the film feed section 24 to perform a special movement. Figure 6 is a left side view illustrating the control to prevent tray adhesion to the heater section as the peeling section of the packaging apparatus according to an embodiment of the present invention, where (a) shows the film feed section 24 going to pick up the film, (b) shows the film being pulled out and heat-sealed, and (c) shows the state immediately after the heat sealing is completed. Unlike Figure 5, the film feed section 24 is shown, but the heater section 2 is omitted from the illustration, as in Figure 5.

[0021] In Figure 6(a), the film feed unit 24 moves to the right to reach the end of the film extending from the roll film R (not shown). After this, Figure 6(b) shows the unit returning to its left position while gripping and pulling out the end of the film, and heat sealing is performed in this state. Figure 6(c) shows the state immediately after this. Although the tray push-up unit 23 has begun to descend, the tray T remains stuck to the heater unit 2 (not shown) and remains in the upper position. When processing large trays, the operation proceeds as described above: Figure 5(b) → Figure 5(c) → Figure 5(b). That is, the tray T descends together with the tray push-up unit 23. This is because the packaged items have a certain amount of weight and therefore do not stick to the heater unit 2. In the case of small trays, the packaged items are often light, and the tray T may stick to the heater unit 2.

[0022] Therefore, in the packaging apparatus 100 according to the embodiment of the present invention, the film feed unit 24, which has returned to the left position, is restarted to the right and moved until it lightly collides with the tray T. Meanwhile, the tray push-up unit 23 is temporarily set to a waiting position, slightly below the heat-sealed position. The position of the tray push-up unit 23 shown in Figure 6(c) is the waiting position. The tray T, which was stuck to the heater unit 2, is released from its adherence and falls due to the impact of the film feed unit 24 collision. The tray push-up unit 23 catches it, and thereafter the tray push-up unit 23 and the tray T descend together.

[0023] Figure 7 is a photograph taken of the actual situation immediately after heat sealing is completed. Figure 7(a) shows the situation where the anti-sticking control is deliberately not performed on the film feed unit 24. You can see that the tray T has stuck to the heater unit 2. Figure 7(b) shows the situation when the anti-sticking control is performed on the film feed unit 24, at the moment (immediately after) when the film feed unit 24 collides with the tray T. You can see that the tray T is peeling off from the right side, which is not collided with by the film feed unit 24. At the moment of collision, the left side of the tray T is in contact with the film feed unit 24, while the right side of the tray T is completely loose, so it peels off from the right side first.

[0024] In the packaging apparatus 100 according to an embodiment of the present invention, the reason for keeping the tray push-up section 23 in a position slightly lowered from the uppermost position is to prevent unnecessary impact on the packaged goods, which may include delicate items. However, this is not essential, and if the goods can withstand some rough handling, it is not necessary to temporarily stop the tray push-up section.

[0025] In the packaging apparatus 100 according to the embodiment of the present invention, the film feed section 24 is configured to perform a peeling operation only for small-sized trays, but it may also be configured to perform a peeling operation for large-sized trays. Furthermore, the program may be set to allow different peeling operations depending on the product. In addition, the weight of the packaged item may be measured, and the peeling operation may be performed if the weight is less than a predetermined threshold.

[0026] As described above, in the packaging apparatus 100 according to the embodiment of the present invention, the film feed section 24 is driven and controlled by software processing to peel off the tray T, but the peeling section may be realized by a physical structure. Figure 8 is an explanatory diagram for understanding the structure and operation of one example thereof.

[0027] The movement from Figure 8(a) to (b) shows the film feed unit 24 moving to the right to pick up the film. In Figure 8(c), the film feed unit 24 returns to the left, and the edge of the tray T, which has been raised by the tray push-up unit 23, is brought into close contact with the heater unit 2, sandwiching the film, and the heat sealing process is performed. As can be understood from Figures 8(a) to (c), and from the photograph in the upper left, this peeling part as a physical structure is located within the circumference of the edge that does not overlap with the edge of the tray, and is a biasing means that separates the tray and film from the heater unit. The biasing means is biased by its own weight. Specifically, the peeling part is located between the film and the heater unit 2 and is retractable. It is retracted until the film feed unit 24 grips and stretches the film, and when the film feed unit stretches the film, the heat sealing is completed, and the tray push-up unit 23 descends, it protrudes by its own weight and peels the tray T from the heater unit 2. In addition, the biasing means may be biased by a spring. Although not shown in the diagram, a suitable number of pin members, for example, two, can be extended and retracted within the circumference of the edge of the tray that does not overlap with the edge, with elastic force from a spring, and the elastic force of the pin members is adjusted to be weaker than the upward force from the tray holder. Furthermore, an actuator may be provided to control the extension and retraction. With this configuration, it becomes possible to differentiate whether or not a peeling operation is performed for each product, or to measure the weight of the packaged item and perform the peeling operation if the weight is less than a predetermined threshold.

[0028] (Relationship between the tray push-up section and the discharge section) The relationship between the tray pushing section 23 and the discharge section 21 will be explained using Figures 9 and 10. Figure 9 is a perspective view showing the tray pushing section 23 and the discharge section 21 of the packaging device 100 according to an embodiment of the present invention, and Figure 10 is a top view showing the tray pushing section 23 and the discharge section 21 of the packaging device 100 according to an embodiment of the present invention. The packaging device 100 according to an embodiment of the present invention is configured to accommodate two different sizes of trays T, and Figures 9 and 10 show the case where it accommodates the larger size tray T. In Figures 9 and 10, the large arrows indicate the direction of movement of the tray T, and in Figure 9, the small arrows indicate the vertical movement of the tray pushing section 23.

[0029] When a tray T containing the packaged items is placed on the loading section 1, the tray T is loaded into the machine. A sensor (not shown) is provided at the loading entrance of the machine to detect the passage of the tray T, and is configured to detect the tray size in the time from when the loading and transport section 11 is activated until the first sensor is blocked. In other words, it utilizes the mechanism that a larger tray T will reach the sensor position faster. Next, the tray pushing section 23 is raised inside the machine to push the tray T upward, and after heat sealing the film and sealing the package, the tray pushing section 23 is lowered and the tray T is placed back to its original height. After that, the discharge section 21 discharges the tray T toward the first discharge platform 3, which is located in the discharge direction perpendicular to the loading direction. In this embodiment of the present invention, the discharge section 21 is composed of eight drive rollers, all of which are arranged inside the tray pushing section 23. The eight drive rollers support the tray T and send it toward the first discharge platform 3.

[0030] The tray push-up section 23 incorporates features to facilitate the lifting of heavy objects. The tray push-up section 23 is not simply rectangular in shape, but is equipped with a support section. While six of the eight drive rollers in the discharge section 21 are equally spaced, the spacing between the fourth and fifth drive rollers from the right or left is wider than the others. A support member (not shown) is provided in the tray push-up section 23 that passes through this wider section, i.e., between the discharge section 21. When the tray is raised, the support member (not shown) passes vertically between the discharge section 21. This support member (not shown) supports the center of the tray, working in conjunction with supporting the edges of the tray. This is to prevent the tray T from bending when heavy objects are placed on it. The shape of the support member may connect both ends of the frame, or it may be divided in the middle.

[0031] In addition to the eight drive rollers of the discharge section 21, six rollers are provided, and these are also arranged inside the tray pushing section 23. The six rollers support the large-sized tray T, but they do not have a driving force and function as a support section 22, being able to rotate freely. To provide the same thrust force to the discharge section 21 consisting of eight drive rollers using six rollers of a different number, free rotation is advantageous as it does not require complex control. However, it is also possible to provide driving force to the rollers corresponding to the support section 22. In such a configuration, it is advisable to switch the drive control so that the six rollers are driven when processing large-sized tray T, and the six rollers are not driven when processing small-sized tray T.

[0032] The first discharge platform 3 is equipped with 10 drive rollers, which transport the tray T toward the second discharge platform 4, where the operator is positioned facing the opposite direction of the loading direction. The second discharge platform 4 is tilted, and the tray T moves by its own weight, so the rollers on the second discharge platform 4 are simply rollers that do not have any driving force.

[0033] As can be understood from the series of movements of these trays T, in the packaging apparatus 100 according to the embodiment of the present invention, as soon as the operator places a tray T on the placement unit 1, the tray T is immediately loaded into the machine, and the heat-sealed tray T is quickly discharged to the second discharge platform 4 located next to the placement unit 1. Once a tray T is loaded into the machine from the placement unit 1, it is immediately possible to place the next tray T to be packaged on the placement unit 1. In other words, there is no need to wait for the first packaging process to be completely finished before placing the next item to be packaged on the placement platform. Furthermore, since the second discharge platform 4 is located next to the placement unit 1, it is also possible to smoothly pick up the tray T after packaging is complete. Both the setting of the tray T before packaging and the picking up of the tray T after packaging are possible to be smoothly performed by a single operator, significantly improving the efficiency of the packaging process.

[0034] The relationship between the tray pushing section 23 and the discharge section 21 when processing small-sized trays T will be explained using Figures 11 and 12. Figure 11 is a perspective view showing the tray pushing section 23 and the discharge section 21 of the packaging device 100 according to an embodiment of the present invention, and Figure 12 is a top view showing the tray pushing section 23 and the discharge section 21 of the packaging device 100 according to an embodiment of the present invention. However, both figures show the process when packaging small-sized trays T. In Figures 11 and 12, the large arrows indicate the direction of movement of the tray T, and in Figure 11, the small arrows indicate the vertical movement of the tray pushing section 23.

[0035] When a tray T containing the items to be packaged is placed on the loading section 1, the tray T is loaded into the machine. A sensor (not shown) located at the loading entrance of the machine confirms that the tray T is small in size. Then, the tray pushing section 23 is raised inside the machine to push the tray T upward, and after heat sealing the film, the tray pushing section 23 is held in a position slightly lowered from the uppermost position to prevent sticking. The tray pushing section 23 that received the tray T is then lowered, and the tray T is placed back to its original height. After that, the discharge section 21 discharges the tray T toward the first discharge platform 3 located in the discharge direction perpendicular to the loading direction. In this embodiment of the present invention, the discharge section 21 is composed of eight drive rollers, all of which are arranged inside the tray pushing section 23. On the other hand, the tray pushing section 23 is not simply rectangular, but has a central crossbar that divides the eight drive rollers of the discharge section 21 into groups of four. The eight drive rollers are designed to support the tray T and move it toward the first discharge platform 3.

[0036] As can be seen from Figures 11 and 11, although the eight drive rollers are located inside the tray push-up section 23, the six rollers are located outside the tray push-up section 23, and a part of the tray push-up section 23 is configured to move up and down between the eight drive rollers and the six rollers. This is because the size of the tray push-up section 23 is different in Figure 9 and Figure 11. Needless to say, this configuration is designed to accommodate two different sizes of trays T. Specifically, the tray push-up section 23 is connectable to (and detachable from) a moving mechanism (not shown) for driving it.

[0037] The first discharge platform 3 is equipped with 10 drive rollers, which transport the tray T toward the second discharge platform 4, where the operator is positioned facing the opposite direction of the loading direction. The second discharge platform 4 is tilted, and the tray T moves by its own weight, so the rollers on the second discharge platform 4 are simply rollers that do not have any driving force.

[0038] Similar to the explanation given for large-sized trays, there is no need to wait for the first packaging process to be completely finished before placing the next item to be packaged on the platform, and the completed tray T can be picked up smoothly. In addition to this, the packaging apparatus 100 of the embodiment of the present invention has the advantage of being able to easily accommodate trays of different sizes. That is, there is no need to prepare a separate packaging apparatus for each different-sized tray T, and there is no need to make major mechanical setting changes when changing sizes. It can be handled simply by replacing the tray push-up section 23 and performing setting operations on the console 5, making it very user-friendly and contributing to overall processing efficiency.

[0039] (Control of the heating element according to the tray size) The control processing of the heating element and related control processing corresponding to the relationship between the size of the tray push-up section 23 and the size of the tray T will be explained. As mentioned above, the packaging apparatus 100 of the embodiment of the present invention can handle two types of trays T of different sizes, large and small, simply by replacing the tray push-up section 23 and performing setting operations on the console 5. For example, when a large-sized tray push-up section 23 is loaded and the setting for large size is made, the amount of film feed and the heating area of ​​the heating element will also correspond to the large-sized tray T. The same applies to the small size.

[0040] Incidentally, due to operator error, situations may arise where the size set on console 5 differs from the size of the tray pusher unit 23 actually loaded, or where the set size and the size of the tray pusher unit 23 match, but the size of the tray T placed on the loading unit 1 differs. In particular, the setting on console 5 is not done separately for "large" and "small," but for convenience, it is sometimes configured to automatically set the size corresponding to the product called up by product code etc. on console 5. In such cases, even if the console screen is configured to display the large and small sizes corresponding to the called product, it is possible to overlook this or continue operating without looking at it, which may actually lead to size misunderstandings. However, as mentioned above, the packaging device 100 of the embodiment of the present invention is equipped with three proximity sensors placed near the initial position of the tray pusher unit 23 and a sensor that detects the passage of the tray T placed at the loading entrance inside the machine, so that setting errors and the like can be dealt with appropriately.

[0041] When the tray pusher unit 23 is loaded and the console 5 is operated to indicate that loading is complete, the tray pusher unit 23 performs an initial movement of moving up and down within a certain range, and the three proximity sensors check whether they detect the tray pusher unit 23. If all three detect it, it is determined to be a large size; if two detect it, it is determined to be a small size. To also detect the possibility of forgetting to load the tray, which is very rare, one sensor is configured to detect a movement mechanism that reacts even if the tray pusher unit 23 is not loaded. If the size of the tray corresponding to the called product does not match the size of the tray pusher unit 23, the console 5 will issue a warning with an image or sound, or take appropriate control such as stopping the subsequent operation of the packaging device. In addition to not only from the perspective of setting errors, the console 5 may be configured to display text such as "large" or "small" or change the screen background so that the set or detected size can be recognized. Furthermore, by determining the size of the tray push-up section 23 using three proximity sensors, if the amount of film feed or the heating area of ​​the heating section, which has been determined by the size setting, differs from the size determined by the proximity sensors, it becomes possible to correct these amounts and areas to appropriate values. Alternatively, the amount of film feed and the heating area of ​​the heating section may not be set in the first place, and the system may be configured to control the feed amount and heating area each time after the size of the tray push-up section 23 is detected and determined.

[0042] The sensor that detects the passage of tray T, which is placed at the loading entrance inside the machine, can detect the tray size in the time from when the loading and transfer unit 11 is activated until the first sensor is blocked during tray loading. With this configuration, for example, if the set or detected tray push-up unit 23 is large but the tray size is small, it is possible to stop the operation of the packaging device or to implement control such as providing an appropriate reject mechanism in the loading and transfer unit 11 to return the tray to the initial position of the mounting unit 1. Alternatively, the tray T may be moved to the first discharge platform 3 and then to the second discharge platform 4 without performing the packaging process, which would eliminate the need to provide a reject mechanism in the loading and transfer unit 11.

[0043] Figure 13 is a diagram illustrating the terminal pattern of the heating element of the packaging device 100 according to an embodiment of the present invention. As mentioned above, the amount of film feed and the heating area of ​​the heating element are determined by the size setting on the console 5, or by the detection and determination of the size of the tray push-up section 23. The heating element is controlled to switch between a mode in which a large area is heated and a mode in which a small area is heated. The three circles shown in Figure 13 are terminals for controlling the energization of the metal plate (heating element), and are a common terminal A, a terminal B for large size, and a terminal C for small size. By selectively energizing the terminal B for large size and the terminal C for small size, it is possible to switch between a large heating area and a small heating area.

[0044] The heating element is configured such that a groove is cut into the support substrate, and a metal plate (heating element) with the shape shown in Figure 13 is embedded along the groove, with a heat-resistant glass sheet attached on top, so that the metal plate does not directly contact the film. In other words, in the packaging device 100, the glass sheet is placed beneath the metal plate. The glass sheet is designed to be easily removed from the substrate, and the metal plate (heating element) can also be easily removed from the support substrate, making maintenance easy. For example, it is possible to replace the glass sheet after 10,000 heat sealing operations, and replace the metal plate (heating element) or the entire substrate after 100,000 heat sealing operations. It is convenient to store the number of heat sealing operations in the memory device of the control board in the console 5 and set up alert processing as needed.

[0045] Figure 14 illustrates another terminal pattern for the heating element of the packaging apparatus 100 according to an embodiment of the present invention. The three circles shown in Figure 14 are terminals for controlling the energization of the metal plate (heating element), and are a common terminal A, a large-size terminal B, and a small-size terminal C. By selectively energizing the large-size terminal B and the small-size terminal C, it is possible to switch between a large heating area and a small heating area. Compared to the embodiment in Figure 13, the common terminal A and the large-size terminal B are located close together, while the common terminal A and the small-size terminal C are located further apart. When heat sealing a small-sized tray T, the area from the vicinity of the small-size terminal C to the common terminal A is not necessary for heat sealing and will generate unnecessary heat. However, since the two terminals are located at the corners of the substrate, it can be advantageous in terms of routing connection wires, etc. Thus, the terminal patterns in Figures 13 and 14 can be selected to be more suitable according to the arrangement constraints required for the entire apparatus.

[0046] (Another embodiment) In the first embodiment, the discharge section 21 was composed of drive rollers, but it may also be composed of a belt conveyor. Also, although the discharge section 21 was provided inside the tray pushing section 23, it is also possible to adopt an configuration in which, for example, the pusher device is placed near the outside of the tray pushing section 23. Although the overall size of the device will be slightly larger, the members supporting the tray T only need to be made of simple rollers that do not have their own driving force, so the support section of the tray T can be divided into many parts. In this case, the pusher device can be placed at any position in the depth direction of the conveyor, so if it is positioned in the center of all sizes of tray T, there will be no bias in the thrust force. In this way, it becomes possible to accommodate a wider range of tray sizes T. Furthermore, with respect to the tray pushing section 23, using the opposite approach, it is also possible to stretch the film at a height position closer to the tray T that has been brought into the machine, and configure the heater section 2 to descend, push down the film and bring it into contact with the tray T, thereby welding it. The pushing up of the tray T and the pushing down of the film may also be used in combination. In these configurations as well, the tray T may still stick to the heater section 2, that is, when the descending heater section 2 turns to move upward, the tray T may be pulled upward, so it is effective to implement a sticking prevention control that causes the film feed section 24 to collide with the tray T. Furthermore, in the first embodiment, the heating element was formed by embedding a metal plate in a groove carved into the support substrate. However, it is also possible to provide a conductive pattern on the substrate itself so that heat is generated by current flow and thermal welding is possible. Even in this case, it is desirable to attach a heat-resistant glass sheet to the substrate to protect the heating element from direct contact with the film, and to create a structure that allows for easy replacement of the glass sheet or the substrate itself depending on the number of heat treatments.

[0047] <Summary of Embodiments> [Technical field] The present invention relates to a packaging device that covers a tray on which an item to be packaged is placed with a film and heat-seals the film to the edge of the tray. [Background technology] Conventional packaging devices have been designed to improve convenience by placing the item to be packaged on a platform and pushing it into the machine, and then automatically pushing the platform out of the machine by an ejection mechanism after heat sealing (see, for example, Patent Document 1). [Prior art document] [Patent] [Patent Document 1] Japanese Unexamined Patent Publication No. 2003-261102 [Overview of the prefecture] [Problems the invention aims to solve] The packaging apparatus described in Patent Document 1 has the drawback that it takes a long time to process because it performs heat sealing by rotating a heating roller. It is conceivable to eliminate the heating roller and process the entire sealing area at once by bringing it into contact with the heating element, but this could cause the packaged item to stick to the sealing area, which would actually hinder the packaging process. [Means for solving the problem] (1) As described above, one aspect of this embodiment is a packaging device 100 for stretching a film and welding the film to the edge of a tray with a heater, characterized in that it comprises a heater section (heater section 2) for welding the film to the edge of a tray (tray T), a tray holding section (tray pushing section 23) for holding the tray, and a release section for preventing the film from sticking to the heater section (heater section 2).

[0048] The above configuration prevents the tray from sticking to the heater section, making it possible to perform proper packaging.

[0049] (2) One aspect of this embodiment is a packaging device 100 described in (1), which is further provided with a film feed section (film feed section 24) for stretching a film, wherein the peeling section is located within the periphery of the edge of the tray and does not overlap with the edge of the tray, and is a biasing means for separating the tray (tray T) and the film from the heater section (heater section 2).

[0050] With the above configuration, by adding a simple physical structure, it becomes possible to prevent the tray from sticking to the heater and to perform proper packaging.

[0051] (3) One aspect of this embodiment is a packaging apparatus 100 described in (1) comprising a film feed section (film feed section 24) for stretching a film and a control section, wherein the peeling section is the film feed section (film feed section 24), and the control section restarts the film feed section (film feed section 24) from the stop position in which it has gripped the film and stretched it, causing it to come into contact with the tray.

[0052] With the above configuration, it is possible to prevent the tray from sticking to the heater and perform proper packaging processing through software processing, without requiring any additional physical structures.

[0053] (4) One aspect of this embodiment is the packaging apparatus 100 described in (3), wherein the tray holding part (tray pushing part 23) pushes up the tray and brings it into contact with the heater part (heater part 2), and the control unit stops the tray holding part (tray pushing part 23) at a predetermined position, and then restarts the film feed part (film feed part 24) to bring it into contact with the tray (tray T).

[0054] With the above configuration, it is possible to prevent the tray from sticking to the heater part without subjecting the packaged items to unnecessary impact, thereby enabling proper packaging. [Explanation of symbols]

[0055] 100 Packaging equipment 1. Mounting section 11. Loading and Transfer Section 111 Endless belt 112 Nails 2 Heater section 21 Discharge section 22 Support part 23 Tray push-up section (tray holding section) 24 Film feed section 3 First discharge platform 4 2nd discharge stand 5 Console T Tray R Roll Film

Claims

[Claim 1] A packaging device that stretches a film and uses a heater to weld the film to the edge of the tray, A heater unit that welds the film to the edge of the tray, A tray holder that holds the tray, The film feed section for stretching the film, It comprises a control unit and, The aforementioned film feed section functions as a release section to prevent the film from sticking to the heater section. The control unit restarts the film feed unit from the stop position where it has gripped and tensioned the film, and brings it into contact with the tray. The tray holding part is designed to push the tray up and bring it into contact with the heater part. The control unit may, after lowering the tray holding unit to a predetermined position and stopping it there, restart the film feed unit to bring it into contact with the tray. A packaging device characterized by the following features.

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