TW202134033A - Thermoforming device - Google Patents

Abstract

This thermoforming device is provided with: a cooling control unit which cools a sheet via a forming mold by causing a cooling liquid to circulate within a flow passage in a cooling plate; a transfer device for transferring a heater; and a transfer control unit for controlling the operation of the transfer device. When the cooling control unit causes the cooling liquid to circulate within the flow passage in the cooling plate, the transfer control unit performs first control so as to: separate the heater away from the cooling plate by causing the transfer device to move the heater in a second direction; and keep the heater separated away from the cooling plate while the cooling liquid within the flow passage in the cooling plate is caused to circulate by the cooling control unit.

Description

Thermoforming device

The invention relates to a thermoforming device.

Patent Document 1 discloses a hot press device for performing hot press processing according to the following process: after heating and pressing a workpiece in a heated metal mold, the metal mold is cooled and the workpiece is heated and pressed. The workpiece is cooled in the metal mold. This hot pressing device includes: a plurality of mold bases each including a metal mold, at least one mold base that can be selected from the plurality of mold bases, a press for pressing the installed mold bases, and a plurality of mold bases. In the mold base, a mold base replacement device installed on the mold base of the press and a temperature adjustment device for heating and cooling the metal mold included in each mold base are replaced. In this hot pressing device, the temperature adjusting device operates to preheat the metal molds of the mold bases when the mold bases are not installed on the press, and to cool the mold bases when the mold bases are installed on the press The metal mold of the mold base. [Prior Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Publication No. 2006-35430

[The problem that the invention wants to solve]

In addition, as a thermoforming device, the inventor of the present application invented the following thermoforming device. Specifically, the thermoforming device includes: a hot plate for heating the formed part of the thermoplastic sheet; a forming die for forming the sheet, with a forming surface on the upper surface of the forming die; a cooling plate, and the forming die The heater is in contact with the lower surface of the cooling plate and heats the forming mold via the cooling plate; and the housing shell has a first opening that opens upwards and houses the The forming mold, the cooling plate, and the heater.

The thermoforming device clamps the sheet between the hot plate located above the accommodating shell and the accommodating shell, and at the same time, the first opening of the accommodating shell is blocked by the hot plate. In this state, The formed part of the sheet heated by contact with the lower surface of the hot plate (for example, the formed part softened by being heated by the hot plate to a temperature higher than the glass transition temperature) is pressed downward by air pressure , And then push it to the forming surface of the forming mold heated by the heater for thermoforming (forming). Then, the sheet material that has been thermoformed in the formed part is cooled by the cooling plate in contact with the lower surface of the forming die via the forming die to harden the sheet material (the part to be formed).

However, in this thermoforming apparatus, it takes a long time to cool the thermoformed sheet in the part to be formed. Specifically, in this thermoforming apparatus, the heater is fixed at a position in contact with the lower surface of the cooling plate. Therefore, during the cooling of the thermoformed sheet of the part to be formed by the cooling plate via the forming die, the heater is in contact with the lower surface of the cooling plate, and therefore, the heat of the heater is directly transferred to the cooling plate. In other words, the cooling plate not only absorbs the heat of the forming die and the sheet, but also absorbs the heat of the heater that has reached a high temperature. Therefore, it takes a long time to cool the thermoformed sheet of the part to be formed.

The present invention has been completed in view of this status quo, and its object is to provide a thermoforming device capable of shortening the cooling time of a sheet whose portion has been thermoformed. [Means used to solve the problem]

One solution of the present invention is a thermoforming device, which includes: Hot plate, heating the formed part of the thermoplastic sheet; A forming die for forming the formed portion of the sheet, having a forming surface on the surface of the forming die, the surface is directed in a first direction, and the back surface of the forming die is directed opposite to the first direction Configure in the second direction; A cooling plate in contact with the back surface of the forming mold; A heater, which is located in the second direction with respect to the cooling plate, and heats the forming mold via the cooling plate; and The accommodating shell has a first opening that opens in the first direction, and accommodates the forming mold, the cooling plate, and the heater, The sheet is clamped between the hot plate and the accommodating housing that are located in the first direction with respect to the accommodating housing, and the accommodating housing is blocked by the hot plate at the same time The first opening portion of the body, in this state, the portion to be formed after being heated is brought into contact with the heating surface of the hot plate facing the second direction by air pressure facing the second direction Pressing, and then pushing it against the forming surface of the forming mold heated by the heater to perform thermoforming, wherein: The cooling plate has a flow channel for cooling liquid to circulate in the inside of the cooling plate, The thermoforming device includes: A cooling control part, after the formed part of the sheet material is pressed against the forming surface of the forming mold and is thermoformed, in a state where the formed part is pressed against the forming surface, Allowing the cooling liquid to circulate in the flow channel of the cooling plate, thereby cooling the formed part of the sheet through the forming die; A moving device to move the heater; and The movement control unit controls the operation of the movement device, The movement control unit performs the first control, that is, When the cooling liquid is circulated in the flow channel of the cooling plate by the cooling control unit, the heater is moved in the second direction by the moving device, thereby causing the The heater is kept away from the cooling plate, and the heater is kept away from the cooling plate while the cooling liquid is circulated in the flow channel of the cooling plate by the cooling control unit .

The above-mentioned thermoforming apparatus includes: a hot plate for heating a part to be formed of a thermoplastic sheet; a forming die for forming (forming) the sheet, and a forming surface for forming the sheet on the surface of the forming die; and a cooling plate , In contact with the back of the forming mold. Furthermore, the forming die is arranged so that the surface faces the first direction (for example, the upper direction) and the back face faces the second direction (for example, the lower direction) opposite to the first direction. In addition, the above-mentioned thermoforming device further includes: a heater located in a second direction with respect to the cooling plate, and heating the forming mold via the cooling plate; The forming mold, the cooling plate, and the heater. Wherein, the cooling plate has a flow channel for cooling liquid to circulate in the inside of the cooling plate. The thermoforming device clamps the sheet between the hot plate located in the first direction relative to the accommodating shell and the accommodating shell, and at the same time, the first opening of the accommodating shell is blocked by the hot plate. In this state Next, the formed part heated by contact with the heating surface of the hot plate (for example, the formed part softened by being heated by the hot plate to a temperature higher than the glass transition temperature) by air pressure to the second Press in the direction, and then push it against the forming surface of the forming mold heated by the heater to perform thermoforming (forming).

In addition, the above-mentioned thermoforming device further includes a cooling control unit, a moving device, and a moving control unit. Among them, the cooling control unit performs the following control: after the formed part of the sheet is pushed against the forming surface of the forming die and thermoformed, the cooling liquid is placed on the cooling plate while the formed part is pushed against the forming surface. Circulate in the flow channel, so as to cool the sheet through the forming die. In addition, the moving device is a device that moves the heater. In addition, the movement control unit controls the operation of the movement device.

Specifically, the movement control unit performs the following control: when the cooling liquid is circulated in the flow channel of the cooling plate by the cooling control unit, the heater is moved in the second direction by the moving device, so that the heater is moved away from the cooling plate , And keep the heater away from the cooling plate while the cooling liquid is circulating in the flow channel of the cooling plate by the cooling control unit (this is the first control). Thus, the cooling plate can efficiently cool the forming mold and the thermoformed sheet of the formed portion.

Specifically, while the cooling control unit causes the cooling liquid to circulate in the flow channel of the cooling plate to cool the forming mold and the sheet of the thermoformed part, the heater is moved away from the cooling plate and the heater There is a space between the cooling plate and the cooling plate, so it is difficult for the heat of the heater to be transferred to the cooling plate and the forming mold. As a result, the cooling plate through which the cooling liquid flows in the runner can quickly cool the forming mold and the sheet material of the thermoformed portion. For example, the temperature of the sheet whose formed part has been thermoformed can be quickly reduced to a preset second target temperature (for example, the temperature at which the formed part of the sheet is sufficiently hardened).

Therefore, according to the above-mentioned thermoforming apparatus, it is possible to shorten the cooling time of the thermoformed sheet of the part to be formed. In other words, according to the above-mentioned thermoforming apparatus, it is possible to increase the cooling rate of the thermoformed sheet of the part to be formed.

Furthermore, thermoforming refers to: the heated (softened by heating) part of the sheet in contact with the heating surface of the hot plate by air pressure presses it in the second direction, and then pushes it to the second direction. The forming surface of the forming mold heated by the heater is shaped (deformed along the forming surface).

In addition, as a method of "pressing the part to be formed in contact with the heating surface of the hot plate and heated by air pressure in the second direction, and then pushing it against the forming surface of the forming mold heated by the heater" For example, the following three methods can be listed. Furthermore, it will include a forming mold, a cooling plate, a heater, an accommodating shell, and a hot plate, and the sheet will be clamped between the accommodating shell and the hot plate that accommodate the forming mold, the cooling plate, and the heater, At the same time, a device for blocking the first opening of the housing shell by a hot plate is used as a forming element.

Method (1): In the internal space of the forming element, the second space (for example, the lower space) located in the second direction (for example, below) is decompressed (evacuated) so that the relatively sheet is positioned in the second direction. The air pressure (air pressure) in the first space (for example, the upper space) in one direction (for example, the upper space) is higher than the air pressure (air pressure) in the second space, by holding the sheet in the opposite direction The pressure difference between the first space and the second space (the amount of difference in air pressure) in the sheet is in contact with the heating surface of the hot plate and the heated part to be formed is pressed in the second direction, and then the formed part is pushed to The forming surface of the forming mold heated by the heater.

Method (2): In the internal space of the forming element, compressed air is supplied to the first space where the sheet material is located in the first direction, so that the air pressure (air pressure) in the first space is higher than that in the second space. The air pressure (air pressure) in the space, the pressure difference between the first space and the second space (the difference in air pressure) between the first space and the second space that hold the sheet in the opposite direction, brings the sheet in contact with the heating surface of the hot plate The heated part to be formed is pressed in the second direction, and the formed part is pushed against the forming surface of the forming mold heated by the heater.

Method (3): A method combining the aforementioned methods (1) and (2). That is, in the internal space of the forming element, the second space is decompressed (evacuated), and compressed air is supplied into the first space, so that the air pressure (air pressure) in the first space is high The air pressure (air pressure) in the second space changes the pressure difference between the first space and the second space (the difference in air pressure) between the sheet and the hot plate. The heated surface of the contact and the heated formed part is pressed in the second direction, and the formed part is pushed against the forming surface of the forming mold heated by the heater.

In addition, according to the thermoforming apparatus, it is preferable that the movement control unit performs the second control after performing the first control, that is, the cooling liquid circulates in the flow channel. After the part to be formed after cooling of the cooling plate is moved to the outside of the forming mold, in order to form a new part to be formed by the forming mold, the heater is moved toward The movement in the first direction brings the heater into contact with the cooling plate, and the forming mold is heated by the heater via the cooling plate.

In the above-mentioned thermoforming apparatus, after the first control is performed, the movement control section performs the following control (this is referred to as the second control): After the part to be formed is moved to the outside of the forming mold, in order to form a new part to be formed by the forming mold, the heater is moved in the first direction by the moving device, thereby bringing the heater into contact with the cooling plate, forming a The heater heats the state of the forming mold via the cooling plate.

Thereby, when a new part to be formed is formed by the above-mentioned thermoforming apparatus, the forming mold can be heated again by the heater via the cooling plate. Therefore, it is also possible to push the newly formed part to be formed against the forming surface of the forming mold heated by the heater to perform thermoforming (forming). That is, it is possible to sandwich the sheet containing the new formed part between the hot plate located in the first direction with respect to the accommodating shell and the accommodating case, and at the same time block the first part of the accommodating case by the hot plate. The opening part, in this state, the new part to be formed after being heated in contact with the heating surface of the hot plate is pressed in the second direction by air pressure, and then it is pushed against the forming mold heated by the heater The forming surface for thermoforming. In this way, in the above-mentioned thermoforming apparatus, a plurality of parts to be formed can be formed in sequence.

In addition, during the period in which the forming mold and the formed portion of the sheet are cooled by the cooling plate through which the cooling liquid flows in the flow channel, the heater is kept away from the cooling plate. Therefore, the heater is not easily cooled and heating can be suppressed. The temperature of the device decreases. Therefore, when a new part to be formed is formed by the above-mentioned thermoforming device, the forming mold can be quickly heated by the heater (for example, to quickly reach the preset first target temperature). Therefore, it is possible to start forming a new part to be formed earlier.

Therefore, according to the above-mentioned thermoforming apparatus, the cycle time of forming can be shortened. Moreover, the cycle time of forming (the time of one cycle) refers to the end of the forming of the currently being formed part and the movement of the part to the outside of the forming mold to the end of the forming of the new part to be formed and The time for the new part to be formed to move to the outside of the forming die.

In addition, according to the thermoforming device, optionally, it includes: a temperature detector that detects the temperature of the forming mold; the second control is performed by the movement control unit, and the temperature is detected After the temperature of the forming mold detected by the detector reaches the preset first target temperature, between the hot plate and the accommodating shell located in the first direction with respect to the accommodating shell Clamping the sheet material including the new formed part, while sealing the first opening of the housing shell by the hot plate, in this state, the air pressure will The heated surface of the hot plate is in contact with the heated surface of the sheet, and the formed portion of the sheet is pressed in the second direction, and then pressed against the forming surface of the forming mold to perform heating Shaped.

The above-mentioned thermoforming device includes a temperature detector to detect the temperature of the forming mold. In addition, in the above-mentioned thermoforming apparatus, the second control is performed by the movement control part (that is, in order to form a new part to be formed, the heater in contact with the cooling plate starts heating the forming mold through the cooling plate), and by After the temperature of the forming mold detected by the temperature detector reaches the preset first target temperature, the sheet material (including the new The first opening of the housing shell is blocked by the hot plate at the same time. In this state, the heated sheet is brought into contact with the heating surface of the hot plate by air pressure. The forming part presses in the second direction, and then pushes it to the forming surface of the forming mold for thermoforming. In this way, a plurality of to-be-formed parts sequentially formed by the above-mentioned thermoforming apparatus can be thermoformed after setting the temperature of the forming die as the first target temperature, respectively.

Furthermore, the first target temperature T1 is preferably set to the glass transition temperature Tg of the sheet or a temperature close to Tg (for example, a temperature in the range of Tg-20°C≦T1≦Tg+20°C). By setting the first target temperature T1 to such a temperature, when the formed portion of the sheet material softened by heating of the hot plate is pushed against the forming surface of the forming mold, it is easy to imitate the shape of the forming surface of the forming mold. Shape the formed part of the sheet (the shape of the formed part of the sheet can be shaped by accurately imitating the shape of the forming surface of the forming die).

In addition, according to the thermoforming device, optionally, the movement control section repeatedly performs the following during the period after the second control is performed to the start of the first control: the third control, once by When the temperature of the forming mold detected by the temperature detector exceeds the first target temperature, the heater is moved in the second direction by the moving device, so as to move the heater away The state of the cooling plate; and the fourth control, once the temperature of the forming die detected by the temperature detector is lower than the first target temperature, the heater is activated by the moving device When moving in the first direction, the heater is brought into contact with the cooling plate, and the forming mold is heated by the heater via the cooling plate.

The above-mentioned thermoforming device includes a temperature detector to detect the temperature of the forming mold. In addition, in the above-mentioned thermoforming apparatus, the movement control unit performs the first control after the second control is performed (that is, after the heater in contact with the cooling plate starts to heat the forming mold via the cooling plate). During the period of time (that is, when the coolant is circulated in the flow channel of the cooling plate, the heater is moved in the second direction by the moving device to move the heater away from the cooling plate), the third control and the fourth control are repeated .

Here, the third control refers to the following control: Once the temperature of the forming mold detected by the temperature detector exceeds the preset first target temperature, the heater is moved in the second direction by the moving device, thereby forming The heater is far away from the cooling plate. In addition, the fourth control refers to the following control: once the temperature of the forming mold detected by the temperature detector is lower than the first target temperature, the heater is moved in the first direction by the moving device, thereby causing the heater and The cooling plate is in contact with each other, and the forming mold is heated by the heater via the cooling plate. By repeatedly performing the third control and the fourth control, the temperature of the forming die can be maintained at the first target temperature (or a temperature close to the first target temperature). In this way, for a plurality of parts to be formed sequentially formed by the above-mentioned thermoforming device, it is possible to heat the forming mold in a state where the temperature of the forming mold reaches the first target temperature (or a temperature close to the first target temperature). Shaped.

In addition, according to any one of the thermoforming apparatuses, optionally, the cooling control section is configured to perform thermoforming after the formed portion of the sheet material is pushed against the forming surface of the forming mold. In the state where the part to be formed is pushed against the forming surface, the cooling liquid is started to circulate into the runner of the cooling plate, and the temperature of the forming die is lowered to a preset second After the second target temperature, or after a preset time for circulating the coolant into the flow channel, stop the flow into the flow channel before the second control is performed by the movement control unit The cooling liquid, and the cooling liquid in the flow channel is discharged to the outside to form a state where the cooling liquid does not exist in the flow channel of the cooling plate. The control unit maintains a state in which the coolant does not exist in the flow passage of the cooling plate during the period from when the second control is performed to the start of the first control.

In the above-mentioned thermoforming apparatus, the cooling control unit performs the following control. Specifically, after the formed part of the sheet material is pushed against the forming surface of the forming die for thermoforming, the cooling liquid starts to flow into the flow channel of the cooling plate in the state where the formed part is pressed against the forming surface Circulation, after lowering the temperature of the forming mold to the preset second target temperature, before performing the second control by the movement control unit, stop the circulation of the cooling liquid in the flow channel, and discharge the cooling liquid in the flow channel to Externally, there is no coolant in the flow channel forming the cooling plate. Alternatively, after the formed part of the sheet material is pressed against the forming surface of the forming die and thermoformed, the cooling liquid is started to flow into the flow channel of the cooling plate in the state that the formed part is pressed against the forming surface, and the After the preset time for circulating the cooling liquid in the flow channel has elapsed, before the second control is performed by the movement control unit, the cooling liquid flow in the flow channel is stopped, and the cooling liquid in the flow channel is discharged to the outside. There is no state of coolant in the flow channel of the cooling plate.

Then, from the time when the second control is performed by the movement control unit (that is, in order to form a new sheet, the heater is moved in the first direction by the moving device, and then the heater is brought into contact with the cooling plate) to the start During the first control (that is, until the heater starts to move downward by the moving device in order to move the heater away from the cooling plate), the state of no coolant in the flow channel of the cooling plate is maintained.

In this way, while the forming mold is heated by the heater via the cooling plate, the cooling plate and the forming mold can be prevented from being cooled by the cooling liquid in the cooling plate. Therefore, the forming mold can be heated by the heater with high thermal efficiency and quickly. In addition, the forming die heated by heating is not cooled by the cooling liquid in the cooling plate. Therefore, the temperature of the heated forming die is not easily lowered, and the thermoforming of the sheet becomes good.

Furthermore, the second target temperature is preferably set to a temperature at which the formed portion of the sheet material is sufficiently hardened by cooling with a cooling plate. In addition, the time for circulating the cooling liquid into the flow channel of the cooling plate is also preferably set to a time for sufficiently hardening the formed portion of the sheet material.

In addition, according to any one of the thermoforming devices, optionally, the moving device is an air cylinder arranged in the second direction with respect to the heater.

In the above-mentioned thermoforming apparatus, as a moving device for moving the heater, an air cylinder provided in the second direction with respect to the heater is used. The air cylinder is configured to extend in the first direction and contract in the second direction. Therefore, by using the movement control unit to expand and contract the air cylinder, it is possible to appropriately move the heater in the first direction or the second direction.

＜Type of implementation＞ Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram of a thermoforming device 1 in an embodiment, that is, a schematic configuration diagram of the thermoforming device 1. FIGS. 2 to 6 are other explanatory diagrams of the thermoforming device 1 in the embodiment, that is, diagrams explaining the flow of the method of forming the sheet 10 by the thermoforming device 1.

As shown in FIG. 1, the thermoforming device 1 of this embodiment includes a hot plate 20, a forming mold 30, a cooling plate 40, a heater 50, and a housing 60. Among them, the hot plate 20 is composed of a rectangular flat metal plate, and is used to heat the formed portion 11 of the thermoplastic sheet 10. Furthermore, a heater not shown in the figure for heating the hot plate 20 is provided on the upper surface side of the hot plate 20. The hot plate 20 is heated by this heater (not shown) to a predetermined temperature (a temperature higher than the set temperature of the glass transition temperature of the sheet 10). In addition, the forming mold 30 is a metal mold that forms a rectangle in a plan view and is used for forming (forming) the formed portion 11 of the sheet 10. This molding die 30 on the surface 30b of the mold 30 has to be shapedPortion 11 of the molding surface 31. Furthermore, the forming die 30 is arranged so that the surface 30b faces the first direction D1 (upward) and the back face 30c faces the second direction D2 (downward) opposite to the first direction D1. In this embodiment, the first direction D1 is taken as the upward direction, and the second direction D2 is taken as the downward direction.

As shown in FIG. 1, the cooling plate 40 is composed of a flat metal plate, which is in contact with the back surface 30 c of the forming mold 30. The cooling plate 40 is fixed in the accommodating shell 60 in a form supported by a plurality of pillars 45 located between the lower surface of the cooling plate 40 (the surface facing the second direction D2) and the bottom surface of the accommodating shell 60. The cooling plate 40 has a flow passage 41 through which the cooling liquid CL flows in the inside of the cooling plate 40. The flow channel 41 in the cooling plate 40 is connected to a liquid circulation pipe 80 connected to a cooling liquid thermostat not shown in the figure. The cooling liquid CL circulates between the cooling liquid thermostat (not shown) and the flow passage 41 in the cooling plate 40 via the liquid circulation pipe 80.

In addition, in FIGS. 1 to 6, as the liquid flow pipe 80, only the liquid flow pipe on the side (set to the IN side) that supplies the cooling liquid CL to the flow passage 41 in the cooling plate 40 is shown, and the liquid flow pipe is omitted from The flow channel 41 in the cooling plate 40 is an illustration of a liquid flow pipe on the side (OUT side) where the cooling liquid CL is discharged. In addition, a valve 81 is provided on the liquid flow pipe 80 on the IN side. In addition, in this embodiment, water is used as the cooling liquid CL, and the temperature of the water as the cooling liquid CL is adjusted to 30°C in a cooling liquid thermostat not shown in the figure. Therefore, in this embodiment, the cooling liquid CL (water) whose temperature is adjusted to 30° C. is supplied to the flow passage 41 in the cooling plate 40.

In addition, a temperature detector 90 is provided inside the cooling plate 40. This temperature detector 90 is provided in the cooling plate 40 in such a manner that the temperature detection portion of the front end portion thereof is exposed from the upper surface (the surface facing the first direction D1) of the cooling plate 40 and is in contact with the back surface 30c of the forming mold 30. Therefore, the temperature of the molding die 30 can be detected by the temperature detector 90. Furthermore, the temperature of the molding die 30 detected by the temperature detector 90 is input to the control device 100 described later. In addition, as the temperature detector 90, a thermocouple or a thermistor can be used.

As shown in FIG. 1, the heater 50 is formed in a flat plate shape, and is provided on the lower side of the cooling plate 40 (in the second direction D2 with respect to the cooling plate 40) in the accommodating case 60. This heater 50 is in contact with the lower surface (the surface facing the second direction D2) of the cooling plate 40, and heats the forming die 30 in contact with the upper surface (the surface facing the first direction D1) of the cooling plate 40 via the cooling plate 40. In this embodiment, the temperature of the heater 50 is set to 200°C. In addition, the accommodating case 60 is formed in a rectangular box shape, and has a first opening 61 that opens upward (the first direction D1). The accommodating shell 60 accommodates the forming mold 30, the cooling plate 40, and the heater 50.

In addition, the thermoforming device 1 of this embodiment includes a cooling control unit 110, an air cylinder 70 as a moving device, and a movement control unit 120 (see FIG. 1). Among them, the cooling control unit 110 controls the flow of the cooling liquid CL into the flow passage 41 of the cooling plate 40. Specifically, the cooling control unit 110 performs the following control: after the formed portion 11 of the sheet 10 is pressed against the forming surface 31 of the forming die 30 and thermoformed, the formed portion 11 is pressed against the forming surface 31 In the state, the cooling liquid CL is allowed to circulate in the flow passage 41 of the cooling plate 40, thereby cooling the sheet 10 (the part 11 to be formed) via the forming die 30. Furthermore, the cooling control unit 110 constitutes a part of the control device 100 composed of a microcomputer.

In addition, the air cylinder 70 as a moving device moves the heater 50 up and down (the first direction D1 and the second direction D2). Four air cylinders 70 are provided below the heater 50 (in the second direction D2 with respect to the heater 50). Specifically, the air cylinder 70 includes a cylindrical housing 72 and a cylindrical piston rod 71. The air cylinder 70 is arranged such that the outer shell 72 is fixed to the outside of the containing shell 60, and the piston rod 71 is inserted into the through hole 65 penetrating the bottom of the containing shell 60 (see FIG. 1).

In addition, the front end portion (upper end portion) of the piston rod 71 is connected to a support 55 extending from the lower surface (a surface facing the second direction D2) of the heater 50 to the lower side (the second direction D2). Therefore, by moving the piston rod 71 of the air cylinder 70 up and down to expand and contract the air cylinder 70 in the vertical direction, the heater 50 can be moved up and down. Furthermore, the opening portion of the through hole 65 on the inner side of the accommodating case 60 is provided with a sealing member not shown in the figure to prevent air from flowing between the inner and outer sides of the accommodating case 60 through the through hole 65, .

In addition, the movement control unit 120 controls the operation of the air cylinder 70 as a movement device. Specifically, in order to move the heater 50 up and down, the piston rod 71 of the control air cylinder 70 moves up and down to expand and contract the air cylinder 70 in the vertical direction. That is, in order to move the heater 50 in the first direction D1 (upward direction), the movement control unit 120 performs control such that the piston rod 71 of the air cylinder 70 is moved in the first direction D1 and the air cylinder 70 is moved in the first direction D1. elongation. In addition, in order to move the heater 50 in the second direction D2 (downward direction), the movement control unit 120 performs control of moving the piston rod 71 of the air cylinder 70 in the second direction D2 and moving the air cylinder 70 in the second direction D2. shrink. Furthermore, the movement control unit 120 constitutes a part of the control device 100 composed of a microcomputer.

In addition, the thermoforming device 1 of this embodiment includes an air pressure adjusting device 150. The air pressure adjusting device 150 includes a compressor 165, a pressurizing tank 160 storing compressed air generated by the compressor 165, a vacuum pump 175, and a vacuum tank 170 connected to (communication) with the vacuum pump 175. The pressurizing tank 160 and the vacuum tank 170 are each arranged so as to be connectable to a vent hole (not shown) that penetrates the hot plate 20 in the vertical direction. In addition, the pressurizing tank 160 and the vacuum tank 170 are each made to be able to be connected to a vent hole (not shown) that penetrates the bottom of the housing case 60 in the vertical direction.

In addition, the thermoforming device 1 of this embodiment includes an air pressure control unit 130 that controls the air pressure adjusting device 150. Furthermore, the air pressure control unit 130 constitutes a part of the control device 100 composed of a microcomputer. Therefore, the control device 100 includes a cooling control unit 110, a movement control unit 120, and an air pressure control unit 130. Here, the molding die 30, the cooling plate 40, the heater 50, the housing case 60, and the hot plate 20 are included, and the sheet 10 is clamped between the hot plate 20 and the first opening 61 to be heated by the heat The plate 20 closes the first opening 61 of the housing 60 containing the forming mold 30, the cooling plate 40, and the heater 50 as the forming element 2 (see FIG. 2).

Specifically, the air pressure control unit 130 performs, for example, the following control: the lower surface (including the heating surface 20c) of the hot plate 20 located above the accommodating case 60 (in the first direction D1 with respect to the accommodating case 60) With the sheet 10 sandwiched between the upper end 62 of the housing shell 60 and the upper end 62 of the housing case 60, connect the vacuum chamber 170 to the vent hole (not shown) of the hot plate 20 of the forming element 2, and set the vacuum pump 175 Drive. Thereby, it is possible to pass through the vent holes of the hot plate 20 of the forming element 2 to the inner space of the forming element 2 (including the vent holes of the hot plate 20, the same below) located above the sheet 10 (first direction D1) Decompression (vacuum) is performed in the space (the first space). As a result, the air pressure (air pressure) in the upper space in the internal space of the forming element 2 is lower than the air pressure (air pressure) in the lower space (second space) below the sheet 10 (second direction D2). Air pressure), by sandwiching the sheet 10 and the pressure difference (the difference in air pressure) between the upper space and the lower space located above and below, the sheet 10 (formed portion 11) can be closely attached to the upper hot plate 20's heating surface 20c.

In addition, the air pressure control unit 130 also performs, for example, the following control: in a state where the sheet 10 is sandwiched between the hot plate 20 located above the accommodating case 60 and the upper end 62 of the accommodating case 60, The pressure groove 160 is connected to a vent hole (not shown) of the housing case 60 of the forming element 2, and compressed air is supplied from the pressure groove 160 to the vent hole of the housing case 60. As a result, in the internal space of the forming element 2, compressed air can be supplied to the lower space below the sheet 10 to be pressurized. Thus, in the internal space of the forming element 2, the air pressure (air pressure) in the lower space is higher than the air pressure (air pressure) in the upper space, and the sheet 10 is sandwiched in the upper and lower spaces. The pressure difference (the amount of difference in air pressure) from the lower space allows the sheet 10 (to be formed by the forming part 11) to be pushed against and closely adhered to the heating surface 20c of the hot plate 20 located above.

In addition, the air pressure control unit 130 also performs, for example, the following control: in a state where the sheet 10 is sandwiched and heated between the hot plate 20 located above the accommodating case 60 and the upper end 62 of the accommodating case 60, The vacuum groove 170 is connected to a vent (not shown) of the housing case 60 of the forming element 2 and drives the vacuum pump 175. Thereby, in the internal space of the forming element 2, the lower space located below the sheet 10 can be decompressed (evacuated). As a result, the air pressure (air pressure) in the lower space is lower than the air pressure (air pressure) in the upper space, and the upper and lower spaces are positioned between the upper and lower spaces by sandwiching the sheet 10 The pressure difference (the amount of difference in air pressure) is capable of pressing the formed part 11 heated in contact with the heating surface 20c of the hot plate 20 in the sheet 10 downward, thereby pushing the formed part 11 against the heater 50 After heating, the forming surface 31 of the forming mold 30 is subjected to thermoforming.

In addition, the air pressure control unit 130 also performs, for example, the following control: a sheet is clamped between the hot plate 20 located above the accommodating case 60 and the upper end 62 (the end in the first direction D1) of the accommodating case 60 While the material 10 is being heated, the pressurizing groove 160 is connected to the vent hole (not shown) of the hot plate 20 of the forming element 2, and compressed air is supplied from the pressurizing groove 160 to the vent hole of the hot plate 20. As a result, in the internal space of the forming element 2, compressed air can be supplied and pressurized to the upper space located above the sheet 10. As a result, the air pressure (air pressure) in the upper space is made higher than the air pressure (air pressure) in the lower space, and the upper space and the upper space in the upper and lower (opposite directions) are positioned by sandwiching the sheet 10 The pressure difference (the difference in air pressure) in the lower space can press the formed portion 11 heated in contact with the heating surface 20c of the hot plate 20 in the sheet 10 downward, thereby pushing the formed portion 11 to The forming surface 31 of the forming mold 30 heated by the heater 50 is subjected to thermoforming.

As this kind of thermoforming device 1, the sheet 10 is clamped between the hot plate 20 located above the accommodating shell 60 and the upper end 62 of the accommodating shell 60, while being sealed by the sheet 10 and the hot plate 20 The first opening 61 of the housing case 60 is blocked. In this state, the air pressure adjusted by the air pressure adjusting device 150 (the air pressure in the internal space of the forming element 2) will be compared with the heating surface of the hot plate 20. The formed portion 11 heated by contact with 20c (for example, the formed portion 11 softened by being heated by the hot plate 20 to a temperature higher than the glass transition temperature of the sheet 10 and lower than the melting point) is directed downward (the first Press in two directions D2), and then push it to the forming surface 31 of the forming mold 30 heated by the heater 50 to perform thermoforming (forming).

Next, a method of forming the sheet 10 using the thermoforming apparatus 1 of this embodiment will be described in detail with reference to FIGS. 1 to 6. Furthermore, in the present embodiment, an example of using a resin sheet made of polycarbonate (glass transition temperature Tg: 150°C, melting point Tm: 250°C), which is rectangular in plan view, as the sheet 10 will be described. .

First, in the sheet placement process, as shown in FIG. 1, the peripheral edge portion of the sheet 10 (the part located around the portion 11 to be formed) is brought into contact with the upper end 62 of the housing case 60, and the sheet 10 is sealed The first opening 61 of the accommodating shell 60 is blocked, and the sheet 10 is placed on the upper end 62 of the accommodating shell 60 in this form. However, at this time, the temperature of the forming mold 30 is adjusted to a preset first target temperature T1 (or a temperature close to the first target temperature T1). Specifically, the heater 50 is brought into contact with the cooling plate 40 in advance, and the forming mold 30 is heated by the heater 50 via the cooling plate 40 so that the temperature of the forming mold 30 is the first target temperature T1 (see FIG. 6), and then borrow The movement control unit 120 repeats the third control and the fourth control described later, thereby maintaining the temperature of the forming mold 30 at the first target temperature T1 (or a temperature close to the first target temperature T1).

Furthermore, in this embodiment, a single-leaf type sheet (for example, a strip-shaped sheet is cut into a predetermined length and divided into a plurality of pieces, which is rectangular in a plan view) is used as the sheet 10. In addition, in this embodiment, for the sheet 10 having a glass transition temperature Tg of 150°C, the first target temperature T1 is set to 140°C. In this way, by setting the first target temperature T1 to a temperature close to the glass transition temperature Tg of the sheet 10 (specifically, to a temperature in the range of Tg-20°C≤T1≤Tg+20°C), When the formed portion 11 of the sheet 10 softened by the heating of the hot plate 20 is pushed against the forming surface 31 of the forming mold 30, it is easy to imitate the shape of the forming surface 31 of the forming mold 30 to form the sheet 10 The part 11 is shaped (the part 11 to be formed of the sheet 10 can be shaped by accurately imitating the shape of the forming surface 31 of the forming die 30).

The third control performed by the movement control unit 120 refers to the following control: once the temperature of the forming mold 30 detected by the temperature detector 90 exceeds the preset first target temperature T1, the air cylinder 70 (moving device) By moving the heater 50 downward (the second direction D2), a state where the heater 50 is away from the cooling plate 40 is formed. In addition, the fourth control performed by the movement control unit 120 refers to the following control: once the temperature of the forming mold 30 detected by the temperature detector 90 is lower than the first target temperature T1, the heater 50 is activated by the air cylinder 70 By moving upward (first direction D1), the heater 50 is brought into contact with the cooling plate 40, and the forming mold 30 is heated by the heater 50 via the cooling plate 40. By repeatedly performing the third control and the fourth control, the temperature of the forming die 30 can be maintained at the first target temperature T1 (or a temperature close to the first target temperature T1).

Next, enter the sheet heating process. As shown in FIG. 2, the hot plate 20 located above (directly above) the housing shell 60 is moved downward (the second direction D2). The sheet 10 is clamped between the upper end 62 of the housing 60, and the first opening 61 of the housing 60 is blocked by the sheet 10 and the hot plate 20. Thus, as described above, the forming assembly 2 is formed. In the forming assembly 2, the first opening 61 of the housing 60 in which the forming mold 30, the cooling plate 40, and the heater 50 are accommodated is formed into the sheet 10 It is clamped between it and the hot plate 20 and blocked by the hot plate 20.

Next, in this state, under the control of the air pressure control unit 130, the vacuum chamber 170 is connected to the vent hole (not shown) of the hot plate 20 of the forming element 2 via the vent pipe 152, and the vacuum pump 175 is driven. Thereby, it is possible to pass through the vent holes (not shown) of the hot plate 20 of the molding assembly 2 to the inner space of the molding element 2 (including the vent holes of the hot plate 20) above the sheet 10 (first direction D1) Decompression (vacuum) is performed in the upper space. As a result, in the internal space of the forming element 2, the air pressure (air pressure) in the upper space is lower than the air pressure (air pressure) in the lower space (the second direction D2) than the sheet 10, by The pressure difference between the upper and lower spaces (the difference in air pressure) between the upper and lower spaces by sandwiching the sheet 10 allows the sheet 10 (formed portion 11) to be in close contact with the heat located above (first direction D1) The heating surface 20c of the plate 20 (see FIG. 2).

In addition, under the control of the air pressure control unit 130, the pressurizing groove 160 is connected to the vent hole (not shown) of the housing case 60 of the forming element 2 via the vent pipe 154, and the pressurizing groove 160 is moved to the housing 60. The vent hole of the housing 60 supplies compressed air. As a result, in the internal space of the forming element 2, compressed air can be supplied and pressurized in the lower space located below the sheet 10. Thereby, in the internal space of the forming element 2, the air pressure (air pressure) in the lower space can be made higher than the air pressure (air pressure) in the upper space. As a result, the pressure difference (the amount of difference in air pressure) between the upper space and the lower space located above and below the sheet 10 while sandwiching the sheet 10 is further increased, so that the sheet 10 (to be formed part 11) can be firmly pushed against and densely packed. Join the heating surface 20c of the upper hot plate 20 (see FIG. 2).

Furthermore, in this embodiment, the temperature of the hot plate 20 is adjusted to 180°C. Furthermore, 180°C is a temperature higher than the glass transition temperature Tg (150°C) of the sheet 10 but lower than the melting point Tm (about 250°C). Therefore, by closely adhering the formed portion 11 of the sheet 10 to the heating surface 20c of the hot plate 20 as described above, the temperature of the formed portion 11 of the sheet 10 can be set to 180°C. The material 10 is softened by the formed part 11. Then, under the control of the air pressure control unit 130, the supply of compressed air from the pressurizing tank 160 to the vent hole of the housing case 60 is stopped, and the driving of the vacuum pump 175 is stopped (the pressure reduction state of the upper space is released).

Next, enter the thermoforming process. Under the control of the air pressure control unit 130, connect the vacuum groove 170 to the vent hole (not shown) of the housing case 60 of the forming element 2 via the vent pipe 154, and make the vacuum pump 175 perform drive. Thereby, in the internal space of the forming element 2, the lower space located below the sheet 10 can be decompressed (evacuated). As a result, the air pressure (air pressure) in the lower space is lower than the air pressure (air pressure) in the upper space, and the upper and lower spaces are positioned between the upper and lower spaces by sandwiching the sheet 10 The pressure difference (the amount of difference in air pressure) can press the formed part 11 heated in contact with the heating surface 20c of the hot plate 20 in the sheet 10 downward, so that the formed part 11 can be pushed by the heater 50. The forming surface 31 of the forming mold 30 after heating is subjected to thermoforming (see FIG. 3).

In addition, under the control of the air pressure control unit 130, the pressurizing groove 160 is connected to the vent hole (not shown) of the hot plate 20 of the forming element 2 via the vent pipe 152, and the pressurizing groove 160 is connected to the hot plate 20 The air vents supply compressed air. As a result, in the internal space of the forming element 2, compressed air can be supplied to the upper space above the sheet 10 to be pressurized. Thereby, the air pressure (air pressure) in the upper space can be made higher than the air pressure (air pressure) in the lower space. Thereby, the pressure difference (the amount of difference in air pressure) between the upper space and the lower space located above and below the sheet 10 is further increased, and the formed portion 11 of the sheet 10 can be moved downward. By pressing, the formed part 11 is pushed against the forming surface 31 of the forming die 30 more forcefully to perform thermoforming (see FIG. 3).

Furthermore, in the present embodiment, during the period from the start of the sheet placement process to the end of the thermoforming process, the movement control unit 120 repeats the aforementioned third control and fourth control, thereby adjusting the temperature of the forming mold 30 Maintain the first target temperature T1 (or a temperature close to the first target temperature T1). As described above, in this embodiment, the first target temperature T1 is set to 140°C.

Next, enter the cooling process. Under the control of the aforementioned air pressure control unit 130, under the control of the cooling control unit 110 in the state where the formed portion 11 of the sheet 10 is pushed against the forming surface 31 of the forming die 30 The cooling liquid CL is allowed to circulate in the flow channel 41 of the cooling plate 40 (see FIG. 4). Specifically, by switching the valve 81, the coolant thermostat (not shown) communicates with the flow passage 41 in the cooling plate 40 through the liquid circulation pipe 80, and the coolant CL is adjusted in the coolant. A thermostat (not shown) circulates between the flow channel 41 in the cooling plate 40. Thereby, the formed portion 11 of the sheet 10 can be cooled via the forming die 30 in contact with the cooling plate 40, and the formed portion 11 of the sheet 10 can be hardened.

In addition, in the cooling process of this embodiment, when the cooling liquid CL is circulated in the flow passage 41 of the cooling plate 40 under the control of the cooling control unit 110, the movement control unit 120 performs the first control. Specifically, as shown in FIG. 4, as the first control, the movement control unit 120 performs the following control (this is referred to as the first control): by moving the piston rod 71 of the air cylinder 70 downward (the second direction D2) The heater 50 connected to the piston rod 71 is moved downward (the second direction D2), and the heater 50 is further moved away from the cooling plate 40, thereby causing the cooling liquid CL to flow on the cooling plate 40 under the control of the cooling control unit 110. During the circulation in the flow channel 41, the heater 50 is kept away from the cooling plate 40. Thus, the cooling plate 40 can efficiently cool the forming mold 30 and the thermoformed sheet 10 of the formed portion 11.

In detail, as shown in FIG. 4, the cooling liquid CL is circulated in the runner 41 of the cooling plate 40 under the control of the cooling control unit 110 to cool the forming mold 30 and the sheet 10 thermoformed in the formed portion 11 During this period, the heater 50 is moved away from the cooling plate 40 to provide a space S between the heater 50 and the cooling plate 40. Therefore, the heat of the heater 50 is not easily transferred to the cooling plate 40 and the forming mold 30. Thereby, by the cooling plate 40 in which the cooling liquid CL circulates in the flow channel 41, it is possible to quickly cool the thermoformed sheet 10 of the to-be-formed portion 11 via the forming die 30.

Furthermore, in the cooling process of this embodiment, the cooling liquid CL starts to flow into the flow passage 41 of the cooling plate 40 under the control of the cooling control unit 110, and then it passes through the cooling liquid CL to the preset flow passage 41. During the time t1 of the internal circulation, the cooling liquid CL continues to flow into the flow channel 41. That is, the cooling liquid CL is allowed to circulate in the flow passage 41 of the cooling plate 40 for the circulation time t1. Therefore, after the circulation time t1 has elapsed since the circulation of the cooling liquid CL into the flow passage 41 of the cooling plate 40 is started, the cooling control unit 110 switches the valve 81 to switch the cooling liquid thermostat (not shown) and the cooling plate 40 The inner flow channel 41 does not communicate via the liquid circulation pipe 80. Thereby, the flow of the cooling liquid CL into the flow passage 41 of the cooling plate 40 is stopped, and the cooling process is ended.

Here, the circulation time t1 is set as the first target temperature T1 (140°C in this embodiment), and the temperature of the forming die 30 is reduced to a preset second target temperature T2 (80°C in this embodiment) The time required. Specifically, a test performed in advance using the thermoforming apparatus 1 is used to measure the temperature from the start of the flow of the cooling liquid CL into the flow channel 41 of the cooling plate 40 to the first target temperature T1 (specifically, 140°C). The time required for the temperature of the forming die 30 to decrease to the second target temperature T2 (specifically, 80° C.) (the circulation time of the cooling liquid CL), and this measured time is referred to as the circulation time t1. As a result, the temperature of the formed portion 11 after thermoforming can be quickly reduced to the second target temperature T2.

Furthermore, the second target temperature T2 is preferably set to a temperature at which the portion 11 to be formed of the sheet 10 is sufficiently hardened. In the present embodiment, for the sheet 10 having a glass transition temperature Tg of 150°C, the second target temperature T2 is set to 80°C. Therefore, in the cooling process, the formed portion 11 after thermoforming can be fully formed. hardening.

To sum up, according to the thermoforming apparatus 1 of this embodiment, the cooling time of the sheet 10 that has been thermoformed in the formed portion 11 can be shortened. That is, according to the thermoforming apparatus 1 of this embodiment, the thermoformed portion 11 can be cooled in a short time. In other words, according to the thermoforming apparatus 1 of the present embodiment, the cooling rate of the sheet 10 that has been thermoformed in the formed portion 11 can be increased.

Next, it enters the discharge process, and discharges the cooling liquid CL in the flow passage 41 of the cooling plate 40 to the outside, forming a state where the cooling liquid CL does not exist in the flow passage 41 of the cooling plate 40 (see FIG. 5). Specifically, compressed air is supplied into the liquid flow pipe 80 on the IN side through a connecting pipe (not shown) connected to the position between the valve 81 and the cooling plate 40 on the liquid flow pipe 80 on the IN side, thereby cooling The cooling liquid CL remaining in the flow passage 41 of the plate 40 is discharged to the outside. As a result, a state where the coolant CL does not exist in the flow passage 41 of the cooling plate 40 (see FIG. 5 ).

In addition, during the discharge process, under the control of the air pressure control unit 130, the driving of the vacuum pump 175 is stopped, and the pressure reduction (evacuation) of the space below the forming element 2 is stopped, and the flow from the pressurizing tank 160 to the forming assembly 2 is further stopped. The air vent (not shown) of the hot plate 20 is supplied with compressed air, thereby stopping the pressurization of the space above the forming element 2.

Next, the take-out process is entered, and the sheet 10 is taken out from the thermoforming apparatus 1, and the sheet 10 includes the portion 11 cooled by the cooling plate 40 that circulates the cooling liquid CL in the flow channel 41. Specifically, as shown in FIG. 5, after the hot plate 20 is moved upward (the first direction D1 ), the sheet 10 is taken out from the housing case 60 (forming mold 30 ). Thereby, the part 11 to be formed cooled by the cooling plate 40 is moved to the outside of the forming mold 30.

Then, the temperature rise process is entered, and the movement control unit 120 performs the second control to increase the temperature of the forming mold 30 after cooling in the cooling process to the first target temperature T1 (140° C. in this embodiment). Specifically, the movement control unit 120 performs the following control (this control is the second control): In order to form a new sheet 10 (new part 11) by the thermoforming device 1, as shown in FIG. 6, by The piston rod 71 of the air cylinder 70 is moved upward (the first direction D1), and the heater 50 connected to the piston rod 71 is moved upward (the first direction D1), so that the upper surface of the heater 50 and the cooling plate 40 The lower surface is in contact with each other, so that the forming mold 30 is heated by the heater 50 via the cooling plate 40.

In detail, the second control is performed by the movement control unit 120. After the heater 50 in contact with the cooling plate 40 starts to heat the forming mold 30 via the cooling plate 40, the control device 100 determines that the temperature detected by the temperature detector 90 Whether the temperature of the forming mold 30 has reached the preset first target temperature T1 (140° C. in this embodiment). If the control device 100 determines that the temperature of the forming mold 30 has reached the first target temperature T1, it ends the temperature increase process. Thereby, the temperature of the forming die 30 can be raised to the first target temperature T1. In addition, during the temperature increase process, under the control of the cooling control unit 110, a state in which the cooling liquid CL does not exist in the flow passage 41 of the cooling plate 40 is maintained (see FIG. 6).

Next, in order to form a new sheet 10 (new part 11 to be formed) by the thermoforming device 1, the aforementioned sheet placement process is entered. Then, the aforementioned series of processes are sequentially performed to form a new sheet 10 (new part 11) by the thermoforming device 1. In this way, in this embodiment, a series of sheet forming processes consisting of a sheet placement process, a sheet heating process, a thermoforming process, a cooling process, a discharge process, a take-out process, and a heating process are repeated. In the cycle, a plurality of sheets 10 (a plurality of to-be-formed parts 11) can be sequentially formed by the thermoforming device 1.

In addition, in this embodiment, after the movement control unit 120 performs the aforementioned second control (that is, in the heating process, after the heater 50 in contact with the cooling plate 40 starts to heat the forming mold 30 via the cooling plate 40, ) To the beginning of the aforementioned first control (that is, in the cooling process of the new sheet 10, when the coolant CL is circulated in the flow passage 41 of the cooling plate 40, the air cylinder 70 starts to cause the heater 50 to flow During the operation of moving down and further moving the heater 50 away from the cooling plate 40), the aforementioned third control and fourth control are repeated.

In detail, the heater 50 is brought into contact with the cooling plate 40 from the heating process, and the forming mold 30 is heated by the heater 50 via the cooling plate 40 so that the temperature of the forming mold 30 reaches the first target temperature T1 (see FIG. 6 During the period from the beginning of the cooling process of the new sheet 10 to the first control described above, the movement control unit 120 repeats the third control and the fourth control, thereby maintaining the temperature of the forming mold 30 Is the first target temperature T1 (or a temperature close to the first target temperature T1).

In addition, in this embodiment, the cooling control unit 110 performs the following control: from the end of the discharge process to the start of the cooling process of the new sheet 10 (new part 11), the cooling plate 40 is maintained. There is no cooling liquid CL in the flow channel 41. Therefore, from the time when the aforementioned second control is performed by the movement control unit 120 (that is, in order to form a new sheet 10, the air cylinder 70 moves the heater 50 upward, thereby causing the heater 50 and the cooling plate 40 to move upward. From the time of contact) to the beginning of the aforementioned first control (that is, to the cooling process of the new sheet 10, in order to keep the heater 50 away from the cooling plate 40, the air cylinder 70 starts to move the heater 50 downward During the period of movement), under the control of the cooling control unit 110, a state where the coolant CL does not exist in the flow passage 41 of the cooling plate 40 is maintained (see FIGS. 6 and 1 to 3).

In this way, while the forming mold 30 is heated by the heater 50 via the cooling plate 40, the cooling plate 40 and the forming mold 30 can be prevented from being cooled by the cooling liquid CL in the cooling plate 40. Therefore, the forming mold 30 can be heated by the heater 50 with high thermal efficiency and quickly. In addition, the forming die 30 heated by heating is not cooled by the cooling liquid CL in the runner 41 of the cooling plate 40. Therefore, the temperature of the heated forming die 30 is not easily lowered, and the thermoforming of the sheet 10 is changed. Well.

Furthermore, in the cooling process, while cooling the forming die 30 and the sheet 10 by the cooling plate 40 with the cooling liquid CL circulating in the runner 41, the heater 50 is moved away from the cooling plate 40, so that the heater 50 is difficult to be removed. By cooling, the temperature drop of the heater 50 can be suppressed. Therefore, when forming a new sheet 10 (new part 11) by the thermoforming device 1, in the heating process, the forming mold 30 can be quickly heated by the heater 50 (to make it quickly reach the preset value). The first target temperature T1). Therefore, it is possible to start forming a new sheet 10 (new part 11 to be formed) early.

Therefore, according to the thermoforming apparatus 1 of this embodiment, the cycle time of forming can be shortened. Furthermore, the cycle time of forming (the time of one cycle) refers to the time when the forming of the currently forming sheet 10 (the currently forming part 11) is completed and the sheet 10 is taken out from the thermoforming device 1 ( That is, from the end of the extraction process) to the end of the forming of the new sheet 10 (new to-be-formed portion 11) and the new sheet 10 is taken out from the thermoforming device 1 (that is, to the end of the new sheet 10). Removal project) time.

<Evaluation of molding cycle time> Next, the cycle time of molding performed by the thermoforming apparatus 1 of the embodiment and the cycle time of molding performed by the thermoforming apparatus of the comparative scheme were compared and evaluated. Specifically, for each thermoforming device, the cycle time of molding and the time required for each process are measured. In addition, the thermoforming apparatus of the comparative scheme is different in that the heater 50 does not move compared with the thermoforming apparatus 1 of the embodiment type, and is the same in other respects. That is, in the thermoforming apparatus of the comparative embodiment, the air cylinder 70 is not provided, and the heater 50 is fixed at a position in contact with the lower surface of the cooling plate 40.

In the thermoforming apparatus 1 of the embodiment type, compared with the thermoforming apparatus of the comparative embodiment, the forming cycle time can be shortened by about 8 minutes and 20 seconds. Specifically, in the thermoforming apparatus of the comparative embodiment, in the cooling process, in order to reduce the temperature of the forming die 30 as the first target temperature T1 (140°C) to the second target temperature T2 (80°C), about 4% are required. minute. In the hot forming apparatus 1 of the implementation type, in the cooling process, the temperature of the forming die 30, which is the first target temperature T1 (140°C), can be reduced to the second target temperature T2 (80°C) in about 40 seconds. . Therefore, in the thermoforming apparatus 1 of the embodiment, the cooling process time can be shortened by about 3 minutes and 20 seconds compared with the thermoforming apparatus of the comparative embodiment. The reason is as follows.

In the thermoforming apparatus of the comparative embodiment, the heater 50 is brought into contact with the cooling plate 40 while the cooling liquid CL is circulated in the flow channel 41 of the cooling plate 40 and the sheet 10 is cooled through the forming die 30 in the cooling process. Therefore, the cooling plate 40 not only absorbs the heat of the molding die 30 and the sheet 10, but also absorbs the heat of the heater 50 that has reached a high temperature. Therefore, in the thermoforming apparatus of the comparative scheme, the cooling efficiency is poor, and it takes a long time to cool the sheet 10. In the thermoforming apparatus 1 of the embodiment type, the air cylinder 70 is operated to move the cooling plate 40 away while the cooling liquid CL circulates in the runner 41 of the cooling plate 40 and cooling the sheet 10 through the forming die 30 Heater 50. Thereby, in the thermoforming apparatus 1 of the embodiment, the influence of the heat of the heater 50 is reduced, and the sheet 10 can be cooled in a short time.

In addition, in the thermoforming apparatus of the comparative embodiment, in the temperature raising process, it takes about 10 minutes to raise the temperature of the forming mold 30 to the first target temperature T1 (140° C.). On the other hand, in the thermoforming apparatus 1 of the implementation type, it takes about 5 minutes to raise the temperature of the forming die 30 to the first target temperature T1 (140° C.) in the temperature-rising process. Therefore, in the thermoforming apparatus 1 of the embodiment type, the heating process time can be shortened by about 5 minutes compared with the thermoforming apparatus of the comparative embodiment. The reason is as follows.

In the thermoforming apparatus of the comparative embodiment, the heater 50 is brought into contact with the cooling plate 40 while the cooling liquid CL is circulated in the flow channel 41 of the cooling plate 40 and the sheet 10 is cooled through the forming die 30 in the cooling process. Therefore, the heater 50 is also cooled. Therefore, in the heating process, when the heater 50 starts to heat the forming mold 30, the temperature of the heater 50 itself has been lowered (lower than the first target temperature T1). Therefore, the temperature of the forming mold 30 is increased to the first target The temperature T1 takes a long time. In the thermoforming apparatus 1 of the embodiment, the cooling liquid CL is circulated in the flow channel 41 of the cooling plate 40 and the sheet 10 is cooled through the forming die 30 during the cooling process, and the cooling plate 40 is moved away from the heater. 50. As a result, the temperature drop of the heater 50 can be suppressed. Therefore, in the heating process, the forming mold 30 can be quickly heated by the heater 50 (to reach the first target temperature T1 quickly).

As mentioned above, the present invention has been described based on the embodiment, but it is obvious that the present invention is not limited to the embodiment, and can be applied with appropriate changes without departing from the gist of the invention.

For example, in the thermoforming apparatus 1 of the implementation type, control is performed so that the cooling control unit 110 starts to flow the cooling liquid CL into the flow channel 41 of the cooling plate 40 until it passes through the preset cooling liquid CL. The cooling liquid CL continues to flow into the flow channel 41 during the time t1 during which the flow channel 41 flows. However, it is also possible to start the flow of the cooling liquid CL into the flow channel 41 of the cooling plate 40 under the control of the cooling control unit 110 until the temperature of the forming die 30 detected by the temperature detector 90 decreases to the second target temperature. T2, the coolant CL continues to flow into the flow channel 41. That is, in the cooling process, it is also possible to perform control so that the temperature of the forming mold 30 is detected by the temperature detector 90 and at the same time the temperature of the forming mold 30 is reduced to the second target temperature T2.

In addition, in the embodiment, the first direction D1 is taken as the upward direction, and the second direction D2 is taken as the downward direction. However, contrary to the embodiment, the first direction D1 may be used as the downward direction, and the second direction D2 may be used as the upward direction. That is, the thermoforming apparatus 1 can be reversed up and down.

In addition, in the embodiment, it is shown that a single-leaf sheet is used (for example, a strip-shaped sheet is cut into a predetermined length and divided into a plurality of pieces, which is rectangular in a plan view) as An example of the sheet 10, and the sheet 10 is formed piece by piece. However, it is also possible to use a strip-shaped sheet (sheet roll) in which a plurality of formed parts are arranged in the longitudinal direction of the sheet, and the strip-shaped sheet is conveyed in the longitudinal direction and sent to the thermoforming device 1 (forming die). 30) Sequentially supplying a plurality of formed parts contained in the sheet, thereby forming the formed parts in sequence.

1: Thermoforming device 10: sheet 11: Formed part 20: Hot plate 20c: heating surface 30: Forming mold 30b: surface 30c: back 31: forming surface 40: cooling plate 41: Runner 45: Pillar 50: heater 55: Pillar 60: housing shell 61: First opening 62: upper end 65: Through hole 70: Air cylinder (moving device) 71: Piston rod 72: shell 80: Liquid circulation pipe 81: Valve 90: temperature detector 100: control device 110: Cooling Control Department 120: Mobile Control Department 130: Air pressure control unit 150: Air pressure regulator 152: Snorkel 154: Snorkel 160: pressure tank 165: Compressor 170: vacuum tank 175: Vacuum pump CL: Coolant D1: First direction D2: second direction

Figure 1 is an explanatory diagram of a thermoforming device in an implementation type; Figure 2 is another explanatory view of the thermoforming device; Figure 3 is another explanatory diagram of the thermoforming device; Figure 4 is another explanatory diagram of the thermoforming device; Figure 5 is another explanatory view of the thermoforming device; Fig. 6 is another explanatory view of the thermoforming apparatus.

1: Thermoforming device

10: sheet

11: Formed part

20: Hot plate

20c: heating surface

30: Forming mold

30b: surface

30c: back

31: forming surface

40: cooling plate

41: Runner

45: Pillar

50: heater

55: Pillar

60: housing shell

61: First opening

62: upper end

65: Through hole

70: Air cylinder (moving device)

71: Piston rod

72: shell

80: Liquid circulation pipe

81: Valve

90: temperature detector

100: control device

110: Cooling Control Department

120: Mobile Control Department

130: Air pressure control unit

150: Air pressure regulator

152: Snorkel

154: Snorkel

160: pressure tank

165: Compressor

170: vacuum tank

175: Vacuum pump

CL: Coolant

D1: First direction

D2: second direction

Claims (6)

A thermoforming device includes: Hot plate, heating the formed part of the thermoplastic sheet; A forming die for forming the formed portion of the sheet, having a forming surface on the surface of the forming die, orienting the surface in a first direction, and orienting the back surface of the forming die in the first direction Configure in the opposite second direction; A cooling plate in contact with the back surface of the forming mold; A heater, which is located in the second direction with respect to the cooling plate, and heats the forming mold via the cooling plate; and The accommodating shell has a first opening that opens in the first direction, and accommodates the forming mold, the cooling plate, and the heater, The sheet is clamped between the hot plate located in the first direction with respect to the accommodating shell and the accommodating shell, while the accommodating shell is blocked by the hot plate The first opening portion of the body, in the state, the molded portion after being heated is brought into contact with the heating surface of the hot plate facing the second direction by air pressure toward the first Press in two directions, and then push it against the forming surface of the forming mold heated by the heater for thermoforming, wherein: The cooling plate has a flow channel for cooling liquid to circulate in the inside of the cooling plate, The thermoforming device includes: A cooling control part, after the formed part of the sheet material is pressed against the forming surface of the forming mold and is thermoformed, in a state where the formed part is pressed against the forming surface, Allowing the cooling liquid to circulate in the flow channel of the cooling plate, thereby cooling the formed part of the sheet through the forming die; A moving device to move the heater; and The movement control unit controls the operation of the movement device, The movement control unit performs the first control, that is, When the cooling liquid is circulated in the flow channel of the cooling plate by the cooling control unit, the heater is moved in the second direction by the moving device, thereby causing the The heater is kept away from the cooling plate, and the heater is kept away from the cooling plate while the cooling liquid is circulated in the flow channel of the cooling plate by the cooling control unit . The thermoforming device according to claim 1, wherein: The movement control unit performs the second control after performing the first control, that is, After the part to be formed cooled by the cooling plate through which the cooling liquid flows in the flow channel is moved to the outside of the forming die, in order to form a new formed part by the forming die Section, the heater is moved in the first direction by the moving device, so that the heater is in contact with the cooling plate, and the forming is heated by the heater via the cooling plate The state of the mold. The thermoforming device according to claim 2, wherein the thermoforming device comprises: A temperature detector detects the temperature of the forming mold, The second control is performed by the movement control unit, and after the temperature of the forming mold detected by the temperature detector reaches a preset first target temperature, the second control is performed relative to the accommodating shell The sheet containing the new formed part is clamped between the hot plate and the accommodating shell in the first direction, and at the same time, the accommodating body is blocked by the hot plate In the first opening of the housing, in the state, the molded portion of the sheet heated in contact with the heating surface of the hot plate is directed toward the first Pressing in two directions, and then pushing it against the forming surface of the forming mold for thermoforming. The thermoforming device according to claim 3, wherein: After the movement control unit performs the second control until the first control starts, it repeats: In the third control, once the temperature of the forming mold detected by the temperature detector exceeds the first target temperature, the heater is moved in the second direction by the moving device, thereby Forming a state where the heater is away from the cooling plate; and Fourth control, once the temperature of the forming mold detected by the temperature detector is lower than the first target temperature, the heater is moved in the first direction by the moving device, As a result, the heater is brought into contact with the cooling plate, and the forming mold is heated by the heater via the cooling plate. The thermoforming device according to any one of claims 2 to 4, wherein: The cooling control part is in a state where the formed part of the sheet material is pushed against the forming surface of the forming mold and thermoformed, and then the formed part is pressed against the forming surface. Next, start to circulate the cooling liquid into the flow channel of the cooling plate, After the temperature of the forming mold is lowered to a preset second target temperature, or after a preset time for circulating the cooling liquid into the flow channel has elapsed, Before the second control is performed by the movement control unit, the flow of the cooling liquid into the flow channel is stopped, and the cooling liquid in the flow channel is discharged to the outside to form the cooling plate The state where the coolant does not exist in the flow channel, and then, During the period from the time when the second control is performed by the movement control unit to the start of the first control, a state in which the cooling liquid does not exist in the flow passage of the cooling plate is maintained. The thermoforming device according to any one of claims 1 to 5, wherein: The moving device is an air cylinder arranged in the second direction with respect to the heater.

Images