Plastic sheet thermoforming machine and sheet feeding device thereof

Abstract

The present invention relates to the technical field of connecting equipment for plastic sheets, and in particular to a plastic sheet thermoforming machine and a sheet feeding device thereof, wherein a sheet feeding device for a plastic sheet thermoforming machine comprises a frame and a hot pressing assembly, wherein the frame is provided with a first supporting unit for placing a working roll and a second supporting unit for placing a spare roll, and the hot pressing assembly is arranged on the frame, and the hot pressing assembly forms a hot pressing channel. The present invention is provided with a hot pressing assembly, and when it is necessary to hot-join new and old sheets together, the hot pressing assembly automatically hot-joins the overlapping parts of the new and old sheets in the hot pressing channel together, and the staff does not need to use auxiliary supplies such as tape to connect the new and old sheets. After the new and old sheets are hot-joined together, the staff only needs to remove the excess parts of the new and old sheets by hand, and does not need to use a knife to cut, so the operation is simpler and more efficient, and the time required to replace a sheet can be greatly shortened.

Description

Technical Field

[0001] The invention relates to the technical field of plastic sheet connection equipment, in particular to a plastic sheet thermoforming machine and a sheet feeding device thereof. Background Art

[0002] The sheet feeding device of the plastic sheet thermoforming machine is an important part of the thermoforming machine. It is responsible for accurately and smoothly conveying the plastic sheet to the heating area to prepare for subsequent forming. The sheet feeding device of the plastic sheet thermoforming machine includes an unwinding mechanism, a guiding mechanism, a tensioning mechanism, a positioning mechanism and a conveying power mechanism. The unwinding mechanism is used to install a whole roll of plastic sheet. With the operation of the thermoforming machine, the unwinding roller is driven by the driving device to smoothly release the sheet at the set speed to ensure the continuity of the sheet supply. When the sheet wound on the current unwinding roller is about to be consumed, the unwinding roller needs to be replaced. When replacing the unwinding roller, the staff usually docks the head of the sheet on the new unwinding roller with the tail of the sheet on the old unwinding roller, and then uses tape to stick the head of the new sheet and the tail of the old sheet together. Finally, use scissors or blades to cut off the excess parts of the new and old sheets, so that the two rolls of sheets are connected together.

[0003] However, when using tape to connect the new and old sheets together, there is the following problem: the staff needs to first connect the new and old sheets together, then use tape to stick the new and old sheets together, then cut the tape, and finally cut off the excess parts of the new and old sheets to complete the connection of the new and old sheets. However, this work efficiency is too low and it takes too long to replace a sheet. Summary of the invention

[0004] Based on this, it is necessary to provide a plastic sheet thermoforming machine and a sheet feeding device thereof to solve the problem of low working efficiency when using tape to connect new and old sheets in view of the problems existing in the current plastic sheet thermoforming machine.

[0005] The above purpose is achieved through the following technical solutions:

[0006] A sheet feeding device for a plastic sheet thermoforming machine comprises:

[0007] A frame, on which a first supporting unit for placing a working roll and a second supporting unit for placing a spare roll are provided;

[0008] A hot pressing assembly is arranged on the frame, and a hot pressing channel is formed on the hot pressing assembly, and the spacing and temperature of the hot pressing channel are adjustable;

[0009] The head of the sheet wound on the working roll and the head of the sheet wound on the standby roll pass through the hot pressing channel from the same side of the hot pressing channel;

[0010] The hot pressing assembly has a working state and a non-working state. When in the working state, the width of the hot pressing channel is at a first spacing so that the sheets in the hot pressing channel can fit each other, and the temperature in the hot pressing channel rises to a first preset temperature.

[0011] When in a non-working state, the interval between the hot pressing channels is at a second interval so that the sheets in the hot pressing channels can be separated from each other, and the temperature in the hot pressing channels is reduced to a second preset temperature.

[0012] Preferably, the hot pressing assembly comprises an upper pressing plate and a lower pressing plate, and the upper pressing plate and the lower pressing plate are spaced up and down to form a hot pressing channel;

[0013] The hot pressing assembly also includes a pressing plate frame, a temperature control element and a linear drive element. The pressing plate frame is arranged on the frame, the lower pressing plate is arranged at the lower part of the pressing plate frame, the temperature control element is embedded in the lower pressing plate, and is used to adjust the temperature of the lower pressing plate. The upper pressing plate is slidingly arranged at the upper part of the pressing plate frame, and the linear drive element is connected between the pressing plate frame and the upper pressing plate, and is used to drive the pressing plate frame to slide vertically, thereby adjusting the distance between the upper pressing plate and the lower pressing plate.

[0014] Preferably, the hot pressing assembly further comprises a first cutting unit and a second cutting unit, and the first cutting unit and the second cutting unit are respectively arranged on both sides of the hot pressing channel;

[0015] The first cutting unit is used to separate the sheets that are bonded to each other in the hot pressing channel and the tail of the sheet wound on the working roll from each other;

[0016] The second cutting unit is used to separate the sheets that are bonded to each other in the hot pressing channel and the heads of the sheets wound on the spare winding roller from each other.

[0017] Preferably, the first cutting unit comprises a first tool holder and a first tool head, the first tool holder is rotatably arranged on the upper part of the pressing plate frame, the first tool holder can rotate around a horizontal axis within a preset angle, and the first tool head is arranged on the first tool holder;

[0018] After the sheets in the hot pressing channel are bonded together, the first knife holder rotates around the horizontal axis within a preset angle so that the first knife head passes through the boundary area between the bonded sheets and the tail of the sheet wound on the working roll.

[0019] Preferably, the second cutting unit comprises a second tool holder and a second tool head, the second tool holder is rotatably arranged at the lower part of the pressing plate frame, the second tool holder can rotate around a horizontal axis within a preset angle, and the second tool head is arranged on the second tool holder;

[0020] After the sheets in the hot pressing channel are bonded together, the second knife holder rotates around the horizontal axis within a preset angle so that the second knife head passes through the boundary area between the bonded sheets and the head of the sheet wound on the spare roll.

[0021] Preferably, the sheet feeding device of the plastic sheet thermoforming machine further comprises a holding member, which is arranged on the pressure plate frame and is used to hold and fix the head of the sheet wound on the spare winding roller.

[0022] Preferably, the sheet feeding device of the plastic sheet thermoforming machine further comprises a tensioning member, which is arranged on the frame and is used to tension the head of the sheet wound on the working roller.

[0023] Preferably, the first supporting unit comprises a supporting groove and a limiting baffle, the supporting groove is opened at the upper part of the frame, and the limiting baffle is arranged on the frame and located at a side of the supporting groove away from the hot pressing assembly.

[0024] Preferably, the second support unit comprises an arc guide rail and a rotating support rod, the arc guide rail is arranged on the frame, one end of the rotating support rod is rotatably arranged on the frame, the rotating support rod can rotate around a horizontal axis, and the rotating support rod is in sliding contact with the arc guide rail.

[0025] A plastic sheet thermoforming machine uses the plastic sheet thermoforming machine sheet feeding device.

[0026] The beneficial effects of the present invention are:

[0027] The present invention is provided with a hot pressing component. When it is necessary to heat-weld the new and old sheets together, the hot pressing component automatically heat-welds the overlapping parts of the new and old sheets in the hot pressing channel together. There is no need for the staff to use auxiliary supplies such as tape to connect the new and old sheets. After the new and old sheets are heat-welded together, the staff only needs to remove the excess parts of the new and old sheets by hand. There is no need to use a knife for cutting. The operation is simpler and more efficient, and the time required to replace a sheet can be greatly shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is an overall schematic diagram of the present invention;

[0029] Figure 2 for Figure 1 A schematic diagram of the enlarged structure in the middle;

[0030] Figure 3 is a side view of the present invention;

[0031] Figure 4 for Figure 3 Schematic diagram of the enlarged structure at B in the middle.

[0032] in:

[0033] 100, rack;

[0034] 110, first support unit; 111, working roll; 112, support groove; 113, limit baffle; 120, second support unit; 121, spare roll; 122, arc guide rail; 123, rotating support rod; 124, third motor;

[0035] 200, hot pressing assembly; 210, upper pressing plate; 220, lower pressing plate; 230, pressing plate frame; 240, linear drive element;

[0036] 250, first cutting unit; 251, first tool holder; 252, first tool head; 253, first motor; 260, second cutting unit; 261, second tool holder; 262, second tool head; 263, second motor;

[0037] 300, holding piece;

[0038] 400, tensioning piece;

[0039] 500, sheet. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in the present invention, unless otherwise specified, include direct and indirect connections (couplings). In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0042] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0043] like Figures 1 to 4 As shown, a sheet feeding device of a plastic sheet thermoforming machine includes a frame 100 and a hot pressing assembly 200. The frame 100 is provided with a first support unit 110 for placing a working roll 111 and a second support unit 120 for placing a spare roll 121. The hot pressing assembly 200 is arranged on the frame 100. The hot pressing assembly 200 is formed with a hot pressing channel. The spacing and temperature of the hot pressing channel are adjustable. The head of the sheet 500 wound on the working roll 111 and the head of the sheet 500 wound on the spare roll 121 are The parts pass through the hot pressing channel from the same side of the hot pressing channel. The hot pressing assembly 200 has a working state and a non-working state. When in the working state, the spacing of the hot pressing channel is at a first spacing so that the sheets 500 in the hot pressing channel can fit together, and the temperature in the hot pressing channel is increased to a first preset temperature. When in the non-working state, the spacing of the hot pressing channel is at a second spacing so that the sheets 500 in the hot pressing channel can be separated from each other, and the temperature in the hot pressing channel is reduced to a second preset temperature.

[0044] In the initial state, the sheet 500 wound on the working roll 111 (hereinafter referred to as the old sheet 500) passes through the hot pressing channel and is connected with the sheet 500 used in the plastic sheet thermoforming machine, and the sheet 500 wound on the spare roll 121 (hereinafter referred to as the new sheet 500) passes through the hot pressing channel from the same side of the hot pressing channel, and the part of the new sheet 500 passing through the hot pressing channel is fixed on the frame 100.

[0045] When there is still some old sheet 500 left, the hot pressing assembly 200 is in a non-working state, and the hot pressing channel is at a second spacing so that the two rolls of sheet 500 in the hot pressing channel can be separated from each other. At this time, the new and old sheets 500 do not contact each other, and the temperature in the hot pressing channel is at a second preset temperature. Specifically, the second preset temperature can be a temperature value between 40 degrees Celsius and 50 degrees Celsius. At this time, the new and old sheets 500 in the hot pressing channel will not be softened by the heat.

[0046] When the remaining amount of the old sheet 500 is about to be exhausted, the plastic sheet thermoforming machine stops feeding. Next, the parts of the new and old sheets 500 located in the hot pressing channel need to be heat-welded together. Specifically, the hot pressing assembly 200 is switched from the non-working state to the working state. At this time, the spacing of the hot pressing channel is reduced from the second spacing to the first spacing, so that the new and old sheets 500 in the hot pressing channel can fit each other. At the same time, the temperature in the hot pressing channel is increased from the second preset temperature to the first preset temperature. The first preset temperature can specifically be a temperature value between one hundred and ten degrees Celsius and one hundred and thirty degrees Celsius, depending on the type of sheet 500. At this time, the new and old sheets 500 are softened by heat and fused together, thereby connecting the new sheet 500 to the sheet 500 used in the plastic sheet thermoforming machine. Next, the staff manually removes the tail of the old sheet 500. The part and the head of the new sheet 500 are removed from the hot-joining position of the new and old sheets 500, and finally the working roll 111 with exhausted surplus is removed from the first support unit 110, and the spare roll 121 is moved from the second support unit 120 to the first support unit 110. At this time, the spare roll 121 is positioned as the working roll 111, and the sheet 500 wound thereon is defined as the old sheet 500. Next, the staff puts a new roll on the second support unit 120, defines it as the spare roll 121, and the sheet 500 wound thereon is defined as the new sheet 500. In addition, the new sheet 500 is also passed through the hot pressing channel from the same side and the part passing through the hot pressing channel is fixed on the frame 100. Next, the hot pressing assembly 200 is switched from the working state to the non-working state, and finally the plastic sheet thermoforming machine continues to feed. When the remaining amount of the old sheet 500 wound on the current working roll 111 is about to be exhausted, it is replaced in the same way, and the details are not repeated here.

[0047] It can be understood that the present invention reduces the number of manual operation steps required by the staff when replacing the sheet 500. When the old and new sheets 500 need to be heat-welded together, the heat-compression welding assembly 200 automatically heat-welds the overlapping portions of the new and old sheets 500 located in the heat-compression welding channel together, and the staff does not need to use auxiliary items such as tape to connect the new and old sheets 500. After the new and old sheets 500 are heat-welded together, the staff only needs to remove the excess portions of the new and old sheets by hand, and there is no need to use a knife for cutting. The operation is simpler and more efficient, and the time required to replace a sheet 500 can be greatly shortened.

[0048] In this embodiment, if Figure 2 and Figure 4As shown, the hot pressing assembly 200 includes an upper pressing plate 210 and a lower pressing plate 220, and the upper pressing plate 210 and the lower pressing plate 220 are spaced up and down to form a hot pressing channel. The hot pressing assembly 200 also includes a pressing plate frame 230, a temperature control element and a linear drive element 240. The pressing plate frame 230 is arranged on the frame 100, and the lower pressing plate 220 is arranged at the lower part of the pressing plate frame 230. The temperature control element is embedded in the lower pressing plate 220 to adjust the temperature of the lower pressing plate 220. The upper pressing plate 210 is slidably arranged at the upper part of the pressing plate frame 230. The linear drive element 240 is connected between the pressing plate frame 230 and the upper pressing plate 210, and is used to drive the pressing plate frame 230 to slide vertically, thereby adjusting the distance between the upper pressing plate 210 and the lower pressing plate 220.

[0049] When the hot pressing assembly 200 is in a non-working state, the upper pressing plate 210 and the lower pressing plate 220 are at a second distance, i.e., a maximum distance. At this time, the distance between the upper pressing plate 210 and the lower pressing plate 220 is much larger than the thickness of the sheet 500. The new and old sheets 500 in the hot pressing channel can be separated from each other, and the temperature control element lowers the temperature of the lower pressing plate 220 to a second preset temperature. At this time, the sheet 500 in the hot pressing channel will not be softened by the heat, and the old sheet 500 wound on the working roller 111 can continuously pass through the hot pressing channel to feed into the plastic sheet thermoforming machine.

[0050] When the remaining old sheet 500 is about to be exhausted, the plastic sheet thermoforming machine stops feeding, and the hot pressing assembly 200 switches from the non-working state to the working state. The linear drive element 240 drives the upper pressure plate 210 to move vertically downward, so that the distance between the upper pressure plate 210 and the lower pressure plate 220 is adjusted to the first distance, that is, the minimum distance. At this time, the distance between the upper pressure plate 210 and the lower pressure plate 220 is slightly equal to the thickness of the sheet 500. At the same time, the temperature control element adjusts the temperature of the lower pressure plate 220 to the first preset temperature. At this time, the new and old sheets 500 in the hot pressing channel are softened by heat and then hot-joined together, thereby completing the docking of the new and old sheets 500.

[0051] It should also be noted that the linear drive element 240 can specifically be any one of a cylinder, a hydraulic rod and an electric telescopic rod. Taking the cylinder as an example, the telescopic end of the cylinder is fixedly connected to the upper pressure plate 210, and the fixed end of the cylinder is arranged on the pressure plate frame 230.

[0052] It should also be noted that the temperature control element can specifically be a thermal wire with a temperature control module, which is embedded in the lower pressure plate 220. The temperature control module controls the amount of heat output by the thermal wire by controlling the current flowing through the thermal wire, thereby controlling the temperature of the lower pressure plate 220 to switch between a first preset temperature and a second preset temperature.

[0053] In this embodiment, in order to further improve the automation level of replacing the sheet 500, as shown in FIG. Figure 3 and Figure 4 As shown, the hot pressing assembly 200 also includes a first cutting unit 250 and a second cutting unit 260. The first cutting unit 250 and the second cutting unit 260 are respectively arranged on both sides of the hot pressing channel. The first cutting unit 250 is used to separate the sheets that are bonded to each other in the hot pressing channel and the tail of the sheet wound on the working roller 111 (that is, the tail of the old sheet 500) from each other, and the second cutting unit 260 is used to separate the sheets that are bonded to each other in the hot pressing channel and the head of the sheet wound on the spare roller 121 (that is, the head of the new sheet 500) from each other.

[0054] When the new and old sheets 500 in the hot pressing channel are heat-welded together, the first cutting unit 250 and the second cutting unit 260 are started, the first cutting unit 250 separates the sheet 500 heat-welded together in the hot pressing channel and the tail of the old sheet 500 from each other, and the second cutting unit 260 separates the sheet 500 heat-welded together in the hot pressing channel and the head of the new sheet 500 (i.e., the part passing through the hot pressing channel), thereby automatically removing the excess parts of the new and old sheets.

[0055] In this embodiment, if Figure 2 and Figure 4 As shown, the first cutting unit 250 includes a first tool holder 251 and a first tool head 252. The first tool holder 251 is rotatably arranged on the upper part of the pressure plate frame 230. The first tool holder 251 can rotate around a horizontal axis within a preset angle. Specifically, a first motor 253 is arranged on the pressure plate frame 230. The output shaft of the first motor 253 is fixedly connected to one end of the first tool holder 251. The first tool head 252 is arranged on the first tool holder 251. After the sheets 500 in the hot pressing channel are bonded to each other, the first tool holder 251 rotates around a horizontal axis within a preset angle so that the first tool head 252 passes through the boundary area between the sheets bonded to each other and the tail of the sheet wound on the working roll 111.

[0056] It should also be noted that, in order to adapt to the movement trajectory of the first tool holder 251, the side of the upper pressure plate 210 close to the first tool holder 251 is an arc surface. In the initial state, the first blade head 252 slides and abuts against the arc surface of the first blade holder 251. In order to enable the first blade holder 251 to rotate within a preset angle around the horizontal axis, the first blade head 252 can cut off the old sheet 500. Specifically, the first blade head 252 is rotatably arranged on the first blade holder 251, and a torsion spring is provided at the rotation connection between the first blade holder 251 and the first blade head 252. When the first blade head 252 slides and abuts against the arc surface of the upper pressure plate 210, the torsion spring is in a force storage state. When the first blade head 252 is out of contact with the arc surface of the upper pressure plate 210, the torsion of the torsion spring is released to make the first blade head 252 rotate counterclockwise around its hinge point, so that the first blade head 252 passes through the old sheet 500 to separate the tail of the old sheet 500 from the heat-joined sheet 500.

[0057] When in use, after the new and old sheets 500 are heat-welded together in the hot pressing channel, the first motor 253 is started, and the output shaft of the first motor 253 drives the first tool holder 251 to rotate around the horizontal axis within a preset angle, so that the first tool head 252 passes through the old sheet 500 to separate the tail of the old sheet 500 from the heat-welded sheet 500, and thereafter, the output shaft of the first motor 253 rotates in the opposite direction to reset the first tool holder 251 to its initial position.

[0058] In this embodiment, if Figure 2 and Figure 4 As shown, the second cutting unit 260 includes a second tool holder 261 and a second tool head 262. The second tool holder 261 is rotatably arranged at the lower part of the pressure plate frame 230. The second tool holder 261 can rotate around a horizontal axis within a preset angle. Specifically, a second motor 263 is provided on the upper pressure plate 210. The output shaft of the second motor 263 is fixedly connected to one end of the second tool holder 261. The second tool holder 261 is driven to rotate around a horizontal axis by the output shaft of the second motor 263. The second tool head 262 is arranged on the second tool holder 261. After the sheets 500 in the hot pressing channel are bonded to each other, the second tool holder 261 rotates around a horizontal axis within a preset angle so that the second tool head 262 passes through the boundary area between the sheets bonded to each other and the head of the sheet wound on the spare roller 121.

[0059] It should also be noted that, in order to adapt to the movement trajectory of the first tool holder 251 , the side of the lower pressing plate 220 close to the second tool holder 261 is an arc surface. In the initial state, the second tool head 262 slides and abuts against the arc surface of the lower pressing plate 220 .

[0060] When in use, after the new and old sheets 500 in the hot pressing channel are heat-connected together, the second motor 263 is started, and the output shaft of the second motor 263 drives the second tool holder 261 to rotate clockwise within a preset angle, and the second tool holder 261 drives the second cutter head 262 to move synchronously. When the second cutter head 262 rotates to pass through the head of the new sheet 500, the sheets that are bonded to each other in the hot pressing channel and the head of the sheet 500 wound on the spare roller 121 are separated from each other. After that, the output shaft of the second motor 263 rotates in the opposite direction to reset the second tool holder 261 to its initial position.

[0061] In this embodiment, Figure 4 As shown, the sheet feeding device of the plastic sheet thermoforming machine further includes a holding member 300 , which is disposed on the platen frame 230 , and is used to hold and fix the head of the sheet 500 wound on the spare winding roller 121 .

[0062] After the head of the sheet 500 wound on the standby roll 121 passes through the hot pressing channel, the pressing member 300 clamps the head of the new sheet 500 , thereby fixing the head of the new sheet 500 on the frame 100 .

[0063] It should be additionally explained that the pressing member 300 may preferably be a spring clip.

[0064] In this embodiment, if Figure 3 As shown, the sheet feeding device of the plastic sheet thermoforming machine further includes a tensioning member 400 . The tensioning member 400 is disposed on the frame 100 . The tensioning member 400 is used to tension the head of the sheet wound on the working roll 111 .

[0065] The purpose of providing the tensioning member 400 is to tension the old sheet 500 and apply an upward force to the old sheet 500 so that the new and old sheets 500 can move away from each other when the thermal compression channel is at the second spacing.

[0066] The tensioning member 400 is specifically composed of a plurality of tensioning rollers, and the specific structure may refer to the tensioning structure in the existing plastic sheet thermoforming machine.

[0067] In this embodiment, if Figure 3 As shown, the first support unit 110 includes a support groove 112 and a limit baffle 113 . The support groove 112 is opened at the upper part of the frame 100 . The limit baffle 113 is arranged on the frame 100 and is located on the side of the support groove 112 away from the hot pressing assembly 200 .

[0068] The support groove 112 is provided to rotatably support the working roll 111 .

[0069] In this embodiment, if Figure 1 and Figure 3 As shown, the second support unit 120 includes an arc guide rail 122 and a rotating support rod 123, the arc guide rail 122 is arranged on the frame 100, one end of the rotating support rod 123 is rotatably arranged on the frame 100, the rotating support rod 123 can rotate around a horizontal axis, and the rotating support rod 123 is slidingly abutted against the arc guide rail 122. Specifically, a third motor 124 is provided on the frame 100, and the output end of the third motor 124 is fixedly connected to the rotating support rod 123, so that the rotating support rod 123 is driven to rotate around the horizontal axis by the third motor 124.

[0070] In the initial state, the rotating support rod 123 is located at the lower end of the arc guide rail 122. When the staff places the new roller at the lower part of the arc guide rail 122 and then starts the third motor 124, the output shaft of the third motor 124 drives the rotating support rod 123 to rotate clockwise around the horizontal axis, so that the rotating support rod 123 pushes the new roller to move upward along the arc guide rail 122 to a preset position.

[0071] When the roller in the support groove 112 is removed, the third motor 124 is started so that the output shaft of the third motor 124 drives the rotating support rod 123 to continue to rotate, thereby causing the rotating support rod 123 to push the current spare roller 121 from the arc guide rail 122 to the support groove 112, after which the third motor 124 rotates in the opposite direction to the initial position.

[0072] It can be understood that the limit baffle 113 is provided to stop and limit the roller. When the roller moves out of the arc guide rail 122 and contacts the limit baffle 113, the limit baffle 113 stops and limits the roller and applies a reverse force to the roller to move the roller into the support groove 112, so that the spare roller 121 can be automatically replaced into the support groove 112.

[0073] A plastic sheet thermoforming machine uses the above-mentioned plastic sheet thermoforming machine sheet feeding device.

[0074] The working principle of the sheet feeding device of the plastic sheet thermoforming machine provided in the above embodiment is as follows:

[0075] When the remaining amount of the old sheet 500 on the working roll 111 is about to be exhausted, the plastic sheet thermoforming machine is first stopped from feeding, and then the telescopic end of the linear drive element 240 drives the upper pressing plate 210 to move downward, so that the spacing of the hot pressing channel is reduced from the maximum spacing to the minimum spacing, and at the same time, the temperature control element adjusts the temperature of the lower pressing plate 220 to the first preset temperature. At this time, the new and old sheets 500 in the hot pressing channel are thermally connected together, and then the first motor 253 and the second motor 263 are started. The first motor The output shaft of the first motor 253 drives the first tool holder 251 to rotate around the horizontal axis within a preset angle, so that the first cutter head 252 passes through the old sheet 500 to separate the tail of the old sheet 500 from the heat-joined sheet 500. After that, the output shaft of the first motor 253 rotates in the opposite direction to reset the first tool holder 251 to the initial position. The output shaft of the second motor 263 drives the second tool holder 261 to rotate clockwise within the preset angle, and the second tool holder 261 drives the second cutter head 262 to move synchronously. When the second cutter head 26 After the first sheet 500 is passed through the head of the new sheet 500, the sheets that are attached to each other in the hot pressing channel and the head of the sheet 500 wound on the spare roll 121 are separated from each other. After that, the output shaft of the second motor 263 rotates in the opposite direction to reset the second knife holder 261 to the initial position. At this time, the telescopic end of the linear drive element 240 drives the upper pressing plate 210 to move upward, so that the spacing of the hot pressing channel is adjusted from the minimum spacing to the maximum spacing, and at the same time, the temperature control element adjusts the temperature of the lower pressing plate 220 to The second preset temperature is then removed from the support groove 112, and the spare roll 121 is placed in the support groove 112, and finally the new roll is placed on the arc guide rail 122, and the new sheet 500 is passed through the same side of the hot pressing channel and the head of the new sheet 500 is fixed on the frame 100 by the holding member 300. Under the action of the tensioning member 400, the new and old sheets 500 in the hot pressing channel are separated from each other, and the plastic sheet thermoforming machine is started at this time to continue feeding.

[0076] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] The above-described embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A sheet feeding device for a plastic sheet thermoforming machine, characterized in that: include: A frame, on which a first supporting unit for placing a working roll and a second supporting unit for placing a spare roll are provided; A hot pressing assembly is arranged on the frame, and a hot pressing channel is formed on the hot pressing assembly, and the spacing and temperature of the hot pressing channel are adjustable; The head of the sheet wound on the working roll and the head of the sheet wound on the standby roll pass through the hot pressing channel from the same side of the hot pressing channel; The hot pressing assembly has a working state and a non-working state. When in the working state, the width of the hot pressing channel is at a first spacing so that the sheets in the hot pressing channel can fit each other, and the temperature in the hot pressing channel rises to a first preset temperature. When in a non-working state, the spacing of the hot pressing channel is at a second spacing so that the sheets in the hot pressing channel can be separated from each other, and the temperature in the hot pressing channel is reduced to a second preset temperature; the hot pressing assembly includes an upper pressing plate and a lower pressing plate, and the upper pressing plate and the lower pressing plate are spaced up and down to form a hot pressing channel; The hot pressing assembly also includes a pressing plate frame, a temperature control element and a linear drive element. The pressing plate frame is arranged on the frame, the lower pressing plate is arranged at the lower part of the pressing plate frame, the temperature control element is embedded in the lower pressing plate, and is used to adjust the temperature of the lower pressing plate. The upper pressing plate is slidingly arranged at the upper part of the pressing plate frame, and the linear drive element is connected between the pressing plate frame and the upper pressing plate, and is used to drive the pressing plate frame to slide vertically, thereby adjusting the distance between the upper pressing plate and the lower pressing plate.

2. A sheet feeding device for a plastic sheet thermoforming machine according to claim 1, characterized in that: The hot pressing assembly further includes a first cutting unit and a second cutting unit, and the first cutting unit and the second cutting unit are respectively arranged on both sides of the hot pressing channel; The first cutting unit is used to separate the sheets that are bonded to each other in the hot pressing channel and the tail of the sheet wound on the working roll from each other; The second cutting unit is used to separate the sheets that are bonded to each other in the hot pressing channel and the heads of the sheets wound on the spare winding roller from each other.

3. A sheet feeding device for a plastic sheet thermoforming machine according to claim 2, characterized in that: The first cutting unit comprises a first tool holder and a first tool head, wherein the first tool holder is rotatably arranged on the upper part of the pressing plate frame, the first tool holder can rotate within a preset angle around a horizontal axis, and the first tool head is arranged on the first tool holder; After the sheets in the hot pressing channel are bonded together, the first knife holder rotates around the horizontal axis within a preset angle so that the first knife head passes through the boundary area between the bonded sheets and the tail of the sheet wound on the working roll.

4. A sheet feeding device for a plastic sheet thermoforming machine according to claim 2, characterized in that: The second cutting unit comprises a second tool holder and a second tool head, the second tool holder is rotatably arranged at the lower part of the pressing plate frame, the second tool holder can rotate around a horizontal axis within a preset angle, and the second tool head is arranged on the second tool holder; After the sheets in the hot pressing channel are bonded together, the second knife holder rotates around the horizontal axis within a preset angle so that the second knife head passes through the boundary area between the bonded sheets and the head of the sheet wound on the spare roll.

5. The sheet feeding device of a plastic sheet thermoforming machine according to claim 1, characterized in that: It also includes a pressing piece, which is arranged on the pressure plate frame and is used to press and fix the head of the sheet wound on the spare winding roller.

6. The sheet feeding device of a plastic sheet thermoforming machine according to claim 1, characterized in that: The machine also comprises a tensioning member, which is arranged on the frame and is used for tensioning the head of the sheet wound on the working roll.

7. The sheet feeding device of a plastic sheet thermoforming machine according to claim 1, characterized in that: The first supporting unit comprises a supporting groove and a limiting baffle. The supporting groove is opened at the upper part of the frame. The limiting baffle is arranged on the frame and is located at a side of the supporting groove away from the hot pressing assembly.

8. The sheet feeding device of a plastic sheet thermoforming machine according to claim 1, characterized in that: The second support unit includes an arc guide rail and a rotating support rod. The arc guide rail is arranged on the frame. One end of the rotating support rod is rotatably arranged on the frame. The rotating support rod can rotate around a horizontal axis, and the rotating support rod is in sliding contact with the arc guide rail.

9. A plastic sheet thermoforming machine, characterized in that: The sheet feeding device of the plastic sheet thermoforming machine according to any one of claims 1 to 8 is used.

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