Heat-seal device

Abstract

To provide a heat-seal device for which accuracy of temperature control and temperature stability on a seal surface are improved, by evenly heating the seal surface of a heater block.SOLUTION: A heat-seal device 10 comprises: a pair of heater blocks 11; seal faces 12 facing each other; and arms 14 for supporting the heater blocks, respectively. The heater blocks each comprise a heat source 13 made from a cartridge heater, and a thermal conductor 16 made from a carbon graphite sheet is attached onto at least a seal face side of the heat source. Heat generated by the heat source can evenly heat the seal faces by planarly and evenly diffusing the thermal conductor. Then, the heat is evenly diffused on the thermal conductor, and thus seal face temperature can be detected with a temperature sensor, and accuracy of temperature control can be improved by comparing heat quantity relating to the seal face temperature with heat quantity generated by the heat source.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a heat-sealing device incorporated in a packaging machine.

Background Art

[0002] The heat-sealing device has a pair of heater blocks made of a metal body such as iron having thermal conductivity. The heater blocks are configured to sandwich the bag mouth of a packaging bag made of synthetic resin on the opposing surfaces. By sandwiching the bag mouth with the heater blocks maintained at high temperature, the bag mouth can be welded.

[0003] Here, as shown in FIG. 15, the heater block 110 used in the conventional heat-sealing device 100 has two through holes with different diameters along the left-right direction when taking the seal surface 111 as a reference in the left-right direction, front-rear direction, and height direction. A heat source part 112 and a heat diffusion part 113 are constituted by a device fitted into the through holes. The heat source part 112 has a cartridge heater fitted into the large-diameter through hole at the rear side. The heat diffusion part 113 has a heat pipe fitted into the small-diameter through hole at the front side. Further, near the seal surface 111 at the end of the heater block 110, a bottomed pore is formed along the height direction. A temperature sensor such as a thermocouple is fitted into the bottomed pore, and a temperature detection part 114 for detecting the temperature of the heater block 110 is constituted.

[0004] The cartridge heater is constituted by a metal pipe and a heating element housed in the pipe. The heating element is configured by winding a metal wire having a relatively high resistance value, such as a nichrome wire, around a mandrel made of an insulator. By energizing the metal wire, the heating element generates heat, and the heat conducts through the metal pipe to make the cartridge heater generate heat.

[0005] The heat pipe is constituted by a metal pipe having a high thermal conductivity and a working fluid sealed in the pipe. The inside of the pipe is kept substantially in a vacuum state, and a capillary structure is arranged along the longitudinal direction of the pipe on the inner surface of the pipe. When the cartridge heater generates heat, the heat source part 112 generates heat and the heat is conducted to the heat dissipation part 113. The heat pipe housed in the heat dissipation part 113 has an evaporation part that receives heat from the heat source part 112 and a condensation part that delivers the received heat to the low-temperature part of the heater block. When the evaporation part receives heat from the heat source part and becomes high in temperature, the working fluid in the heat pipe evaporates in the evaporation part and becomes a gas having latent heat, and the gas moves to the condensation part. The gas that has reached the condensation part dissipates heat to the low-temperature part of the heater block and returns to a liquid, and the liquid moves to the evaporation part through the capillary structure by capillary action. Since the vaporization, liquefaction, and movement of the working fluid operate at high speed and continuously, in the heater block 110, the heat dissipation part 113 can quickly conduct the heat received from the heat source part 112, and the temperature distribution of the heater block 110 can be quickly balanced. And the heat of the cartridge heater possessed by the heat source part 112 is conducted and diffused to the heater block 110 by the heat pipe of the heat dissipation part 113. The heat of the heater block 110 is configured to be controlled based on the temperature detected by the temperature detection part 114 having a temperature sensor arranged at the end of the heater block 110.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the heater block 110 having the above configuration, the cartridge heater fitted into the large-diameter through hole is pressed and fixed with a bolt (not shown) from the anti-sealing surface side toward the sealing surface 111 side. As a result, since the anti-bolt side of the cartridge heater pressed by the bolt on the inner surface of the large-diameter through hole is intensively pressed, heat is concentrated in this portion, and there is a problem that the heat conduction in the heater block 110 becomes extremely non-uniform. Further, since the cartridge heater is pressed against one side of the inner surface of the large-diameter through hole, a gap is generated on the other side. Although a measure of filling the gap with thermal joint grease can be taken, the wiring of the cartridge heater must be drawn so that there is no grease leakage, and there is a possibility that the handling of the heater block 110 becomes difficult.

[0008] Further, as described above, the heat pipe is configured to diffuse heat by performing a latent heat cycle of the working fluid between the evaporation section and the condensation section. However, inside the heated heater block 110, the entire heat pipe is at a high temperature, and the working fluid has vaporized at any location. Therefore, it is considered that the function of equalizing the heat of the heater block is weakened. Further, since a gap is generated between the heat pipe disposed inside the heater block and the heater block, similarly to the above-described cartridge heater, thermal joint grease must be filled, and there is also a risk of grease leakage. And, the temperature sensor of the temperature detection unit 114 does not measure the hottest part at the center of the sealing surface 111 due to the structure of the heater block 110, but measures a relatively low-temperature part at the periphery of the sealing surface 111. Therefore, there is a problem that the temperature change of the sealing surface 111 that is most desired to be controlled in heat sealing cannot be sufficiently detected. All of these are caused by the insufficient heat conduction efficiency in the heater block 110 and on the sealing surface 111, and there is a problem that temperature control that finely follows the temperature change is not sufficiently performed with respect to the sealing surface 111 and also with respect to the heating time of the heater block 110.

[0009] Accordingly, the problem to be solved by the present invention is to provide a heat-sealing device that evenly heats the sealing surface of a heater block and improves the temperature stability and temperature control accuracy of the sealing surface.

Means for Solving the Problem

[0010] The heat-sealing device according to claim 1 comprises a pair of heater blocks each made of a metal columnar member and having sealing surfaces facing each other, and is at least composed of a heat source for heating one or both of the pair of heater blocks respectively, and is a heat-sealing device in which the heated pair of heater blocks sandwich and weld a superposed portion of a packaging material made of a heat-welded member, characterized in that a heat conductor made of a thin film or a flexible thin plate is disposed between the heat source and the sealing surface of the heater block over the length of the sealing surface along the longitudinal direction of the heater block.

[0011] The heat-sealing device according to claim 2 is the invention according to claim 1, wherein a through hole along the longitudinal direction is formed at a predetermined position along the width direction and the height direction of the heater block, and a columnar heat source with the heat conductor adhered at least on the sealing surface side is fitted into the through hole.

[0012] The heat-sealing device according to claim 3 is the invention according to claim 1, wherein the heater block is divided at a predetermined position in the width direction to form a first block body and a second block body that engages with the first block body and has the sealing surface, a through hole along the longitudinal direction is formed at a predetermined position along the width direction and the height direction of the first block body, characterized in that the columnar heat source is fitted into the through hole and the heat conductor is sandwiched by a clamping surface formed between the first block body and the second block body.

[0013] The heat seal device according to claim 4 is, in the invention according to claim 1, wherein the heater block is divided at a predetermined position in the width direction to form a first block body and a second block body that engages with the first block body and has the seal surface. When the first block body and the second block body are joined, groove portions facing each other along the longitudinal direction are formed in the first block body and the second block body along the longitudinal direction so that a hole portion along the longitudinal direction is formed between the first block body and the second block body. The heat conductor is adhered to at least the seal surface side of the heat source formed in a columnar shape. The heat source and the heat conductor are fitted into one of the groove portions of the first block body or the second block body. The heat source and the heat conductor are arranged in the hole portion formed between the joined first block body and second block body.

[0014] The heat seal device according to claim 5 is, in the invention according to claim 1, wherein the heater block is divided at a predetermined position in the width direction to form a first block body, a second block body, and a third block body having the seal surface. When the first block body and the second block body are joined, groove portions facing each other along the longitudinal direction are formed in the first block body and the second block body along the longitudinal direction so that a hole portion along the longitudinal direction is formed between the first block body and the second block body. The heat source formed in a columnar shape and the heat conductor wound around the heat source are fitted into the groove portion. The heat source and the heat conductor are arranged in the hole portion formed between the joined first block body and second block body, and the heat conductor is drawn out and sandwiched between the first block body or the second block body and a sandwiching surface formed between the first block body or the second block body and the third block body on the side opposite to the seal surface of the seal surface.

[0015] The heat-sealing device according to claim 6 is, in the invention according to claim 1, wherein the heater block is divided at a predetermined position in the width direction to form a first block body and a second block body that engages with the first block and has the sealing surface. An electric heat source capable of generating eddy currents is disposed in the heat source side block body in the vicinity of the first block body. The heat conductor having conductivity and a high resistance value is sandwiched by a clamping surface formed between the first block body and the second block body. When the electric heat source is energized, the heat conductor is induction-heated from the first block body side, which is characterized in that.

[0016] The heat-sealing device according to claim 7 is, in the invention according to claim 1, wherein the heater block is divided at a predetermined position in the width direction to form a first block body having the sealing surface and a second block body that engages with the first block body. An electric heat source capable of generating eddy currents is disposed in the first block body in the vicinity of the first block body. A heat insulating portion is provided between the electric heat source and the upper surface of the first block body. The heat conductor having conductivity and a high resistance value is sandwiched by a clamping surface formed between the first block body and the second block body. When the electric heat source is energized, the first block body and the heat conductor are induction-heated, which is characterized in that.

[0017] The heat-sealing device according to claim 8 is, in the invention according to claim 7, characterized in that the heat insulating portion has a ceramic plate material.

[0018] The heat-sealing device according to claim 9 is, in the invention according to any one of claims 1 to 7, characterized in that the heat conductor is made of a carbon graphite sheet.

[0019] The heat-sealing device according to claim 10 is characterized in that, in the invention according to any one of claims 1 to 7, a temperature sensor is arranged at a predetermined position in contact with the heat conductor.

Advantages of the Invention

[0020] According to the heat-sealing device of the present invention, a heat conductor made of a thin film or a thin plate having flexibility is arranged between a heat source for heating a heater block and a sealing surface of the heater block. As a result, the heat from the heat source spreads in a planar manner through the heat conductor, and the heat can be evenly diffused to the sealing surface. Preferably, a heat conductor made of a thin film or a thin plate having flexibility is adhered to at least the sealing surface side of a columnar heat source such as a cartridge heater, and the heat source is fitted into a through hole. As a result, the heat from the heat source is diffused in a planar manner, and the gap between the heat source and the inner surface of the through hole is widened in a planar manner, and the heat conductor having improved adhesion, particularly a carbon graphite sheet having flexibility and elasticity in the thickness direction, can be used to fill the gap. The heat source can be fixed in the through hole without filling a liquid such as thermal joint grease in the gap, and the heat can be evenly diffused. Preferably, a heat conductor made of a thin film or a thin plate having flexibility is sandwiched between the opposing clamping surfaces of the divided heater blocks. Further, a groove portion is provided along the longitudinal direction on the clamping surface, and a columnar heat source is fitted into the groove portion, and a heat conductor is adhered at least to the sealing surface side. As a result, the heat conducted from the heat source to one block body is diffused in a planar manner by the heat conductor and conducted to the other block body on the sealing surface side, so that the heat can be evenly diffused. More preferably, the heat conductor sandwiched between the opposing clamping surfaces of the divided heater blocks is induction-heated by an electric heat source arranged in the vicinity of the heat source side heater block. As a result, the heat conductor made of a thin film or a thin plate having flexibility is evenly heated by eddy currents, and the heat can be evenly diffused to the heater block. Moreover, the heat conductor composed of a thin film or a thin plate with flexibility is preferably a carbon graphite sheet. In this way, when the heat source is a cylindrical cartridge heater, it can be brought into close contact with a curved surface, and when it is sandwiched between the sandwiching surfaces between the heat source side heater block and the seal surface side heater block, a predetermined pressure can be applied to bring it into close contact with the sandwiching surface. Therefore, heat can be evenly diffused to the heater block. Furthermore, it is preferable to arrange a temperature sensor at a predetermined position of the heat conductor composed of a thin film or a thin plate with flexibility. This makes it possible to accurately measure the temperature at any location of the heat conductor formed so that heat is evenly diffused, and to improve the temperature stability of the seal surface and the accuracy of temperature control.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

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Figure 7

Figure 8

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Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Example 1

[0022] Examples of the heat-sealing device according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is an explanatory view showing the schematic configuration of the heat-sealing device according to the present embodiment. Further, FIG. 2 is an explanatory view showing the schematic configuration of a heater block included in the heat-sealing device according to the present embodiment, and FIG. 3 is an exploded perspective view showing the schematic configuration of a heater block included in the heat-sealing device according to the present embodiment.

[0023] As shown in FIG. 1, the heat-sealing device 10 includes a pair of heater blocks 11, 11 having seal surfaces 12 facing each other, a heat source 13 for heating the heater blocks 11, and arms 14, 14 that can be freely moved away from and close to the heater blocks 11, 11 supported at their tips. In the heat-sealing device 10, the heater block 11 heated by the heat source 13 sandwiches the overlapped portion of the packaging material having heat-sealability with the seal surface, for example, seals the bag mouth of the packaging bag B or forms a pillow-shaped packaging bag into a cylindrical shape. Then, the time when the sealing surface 12 sandwiches the packaging material, the temperature of the heat source 13, the opening and closing speed of the arm 14, and the pressure with which the arm 14 presses the heater block pairs 11, 11 against each other are controlled by a control unit (not shown) provided in the heat sealing device 10 or the packaging machine in which the heat sealing device 10 is incorporated. As a result, in the heat sealing device 10, the heater block pairs 11, 11 provided at the tips of the arms 14 that open and close at a predetermined timing are heated and controlled to a predetermined temperature range where the overlapped portions of the packaging material are welded to each other by the sealing surface 12, and the packaging material is sandwiched at a predetermined pressure for a predetermined time, so that the overlapped portions of the packaging material can be welded.

[0024] As shown in FIG. 2 or FIG. 3, the heater block 11 is composed of a columnar metal member. A sealing surface 12 is formed on the metal member. Hereinafter, the surface on which the sealing surface 12 of the heater block 11 is formed is defined as the front side, the direction along the longitudinal direction of the sealing surface 12 is defined as the longitudinal direction of the heater block 11, and the direction from the sealing surface 12 toward the back is defined as the width direction of the heater block. As shown in FIG. 2, when viewed in cross section along the width direction, the sealing surface 12 is formed to protrude forward, and as shown in FIG. 3, it is formed in a planar shape along the longitudinal direction. The sealing surface 12 is arbitrarily processed according to the packaging material to be sealed, for example, a solid surface without unevenness as shown in FIG. 3, or a striped surface with predetermined stripes engraved. As shown in FIG. 2, a through hole 15 extending along the longitudinal direction is formed at a predetermined position along the width direction and the height direction in the back direction of the sealing surface 12. A heat source 13 and a heat conductor 16 are fitted into the through hole 15. Then, a screw hole 17 is formed from the back to the front of the heater block 11 toward the through hole 15. A pressing bolt (not shown) is screwed into the screw hole 17. As a result, the pressing bolt can press the heat source 13 and the heat conductor 16 to fix the heat source 13 in the through hole 15 and bring the heat conductor 16 into close contact with the inner surface of the through hole 15. Then, a small-diameter through-hole smaller than the through-hole 15 is formed so as to communicate with the inner surface on the seal surface side of the through-hole 15. A temperature sensor 18 is fitted in the small-diameter through-hole such that the heat detection part at the tip contacts the heat conductor 16. Note that the heater block 11 according to the present embodiment is preferably made of iron, but is not limited thereto. For example, a metal having high thermal conductivity such as copper can be appropriately selected. Also, as shown in FIG. 1, the present invention is not limited to a configuration in which through-holes are provided on both sides of the heater block 11 and both sides of the heater block 11 are heated by the heat source 13. A through-hole 15 for fitting the heat source 13 may be provided on one side of the heater block 11, and the other side may not be provided with the heat source 13, or a cooling device may be fitted in the through-hole 15. One side may be a heater block for heating, and the other side may be configured as a heat dissipation block capable of dissipating heat or cooling the seal surface.

[0025] The heat source 13 is composed of a cartridge heater. The cartridge heater includes a heating element formed by winding a heating wire such as a nichrome wire around a core rod having thermal conductivity, and a cylindrical case for housing the heating element. The heating element incorporates a temperature sensor, preferably a thermocouple. Thereby, when the energized heating element is heated to a predetermined temperature at which the packaging material can be welded, the control unit is configured to maintain the predetermined temperature based on the heat source temperature signal output from the thermocouple. As shown in FIG. 2 or FIG. 3, a thin-film heat conductor 16 wound around about 1 / 3 of the circumference centered on the seal surface 12 side is adhered to the outer surface of the cylindrical case.

[0026] The heat conductor 16 is composed of a carbon graphite sheet having a thickness of 0.1 mm and a thermal conductivity of 1000 W / m·K. Here, the carbon graphite sheet is a heat conductor formed by mixing carbon and graphite in a predetermined ratio to form a thin film, and stacking one or two or more sheets to form a flexible thin film with a thickness of about 0.1 mm to 1 mm. The thermal conductivity of the carbon graphite sheet is adjusted to about 200 to 2000 W / m·K by changing the sheet thickness, stacking extremely thin films, or stacking a predetermined number of thin films with different mixing ratios of carbon and graphite. When the carbon graphite sheet is thinner than 0.1 mm, heat conducts extremely quickly in the thickness direction before spreading in the plane direction of the carbon graphite sheet, and there is a risk of heat bias occurring on the seal surface 12. Also, when it is thicker than 1 mm, the flexibility of the carbon graphite sheet is lost, and there is a risk of damage when winding it around a cartridge heater or performing bending processing. And when the thermal conductivity is less than 200 W / m·K, there is a risk of heat bias occurring on the seal surface 12 due to slow heat diffusion rates in both the plane direction and the thickness direction. Also, when the thermal conductivity is greater than 2000 W / m·K, the diffused heat is quickly dissipated, making it difficult to control the temperature of the seal surface 12. Compared with the conventional carbon graphite sheet in which a thin-film carbon graphite material is sandwiched between insulator sheets, the carbon graphite sheet according to this embodiment configured as described above can quickly conduct heat not only in the plane direction but also in the thickness direction, evenly and quickly diffusing heat. Therefore, together with the heat equalization of the heater block 11, the temperature control of the seal surface 12 can be facilitated. Note that the heat conductor 16 according to this embodiment is not limited to the carbon graphite sheet, and may be a carbon sheet formed by knitting carbon fibers, a thin film using graphene composed of carbon atoms with an extremely thin sheet-like structure, a metal with excellent thermal conductivity such as gold, platinum, silver, or copper formed in a foil or thin plate shape, a carbon plate cut out in a thin plate shape, or a flexible thin plate.

[0027] The temperature sensor 18 is composed of a thermocouple having a detection part at its tip. As shown in FIG. 2, the detection part is configured to be in contact with the carbon graphite sheet which is the heat conductor 16. In this embodiment, the detection part is configured to be in contact with the heat conductor 16, but the present invention is not limited thereto, and even if it does not contact the heat conductor 16, the detection part may be arranged near the seal surface 12 side. Thereby, the heat conducted from the heat source 13 to the carbon graphite sheet and diffused is detected, and a seal surface temperature signal based on the amount of heat is output from the temperature sensor 18 to a control unit (not shown). The control unit into which the seal surface temperature signal is input is configured to control the temperature of the heating element of the heat source 13 based on the fed-back seal surface temperature signal and the heat source temperature signal of the heating element. The temperature sensor 18 is preferably a thermocouple, but is not limited thereto, and any device capable of detecting the amount of heat or the temperature based on the amount of heat may be used.

[0028] In the heat sealing device 10 having the above configuration, a cartridge heater which is the heat source 13 is fitted into the through hole 15 of the heater block 11, and the cartridge heater is pressed and fixed to the seal surface 12 side by a pressing bolt screwed into the screw hole 17 from the rear surface side of the heater block 11 toward the seal surface 12 side. Since the carbon graphite sheet which is the heat conductor 16 is adhered to the outer surface of the cartridge heater with the seal surface 12 side as the center, when the pressing bolt presses the cartridge heater, the carbon graphite sheet adheres to the inner surface on the seal surface 12 side of the through hole 15. Thereby, the heat of the heat source 13 is evenly diffused along the inner surface on the seal surface 12 side of the through hole 15 by the carbon graphite sheet which is the heat conductor 16, and the heat conducted through the heater block 11 can evenly heat the seal surface 12. And, since the carbon graphite sheet has elasticity and furthermore, even when crushed, there is no change in thermal conductivity, the sheet itself pressed by the pressing bolt can be compressed to fill the gap formed between the heat source 13 and the through hole 15. Therefore, unlike conventional heat seal devices, there is no need to fill the inside of the through hole with a liquid such as thermal joint grease to fill the gap generated between the heat source 13 and the through hole 15, so that liquid leakage from the through hole 15 can be prevented during the operation of the heat seal device 10.

[0029] Then, the temperature sensor 18 is installed on the heater block 11 so that the detection part of the temperature sensor 18 contacts the carbon graphite sheet. Since heat is evenly diffused over the entire sheet of the carbon graphite sheet and it is arranged on the seal surface 12 side of the heat source 13, the temperature sensor 18 can detect the temperature in the vicinity of the seal surface 12. The temperature detected by the temperature sensor 18 is converted into a seal surface temperature signal and output to the control unit. The control unit (not shown) of the heat seal device 10 compares the heat source temperature signal obtained from the temperature sensor of the cartridge heater of the heat source 13 with the seal surface temperature signal obtained from the temperature sensor 18 in contact with the carbon graphite sheet, determines whether to heat the seal surface 12 or wait for heat dissipation from the seal surface 12, and performs a process of controlling the amount of heat of the heat source 13 or the temperature based on the amount of heat. Thereby, the seal surface 12 of the heater block 11 can be maintained at a predetermined temperature optimal for welding the packaging material.

[0030] According to the heat seal device 10 according to the first embodiment, in order to equalize the temperature distribution of the seal surface 12 of the heater block 11, a heat conductor 16 made of a carbon graphite sheet having a high thermal conductivity is disposed between the heat source 13 and the seal surface 12. Since heat quickly diffuses along the surface direction of the carbon graphite sheet, the temperature distribution of the seal surface 12 can be equalized. Also, unlike a conventional heat pipe, a carbon graphite sheet, due to its structure, does not break even when pressed and its thermal conductivity remains unchanged. Therefore, it can be closely attached to the inner surface of the through hole 15 together with the heat source 13 from the anti-sheet surface 12 side toward the sheet surface 12 side. Moreover, when the heat sealing device 10 is operated, since there is no risk of breakage like a heat pipe, the durability can be improved while maintaining a high thermal conductivity.

Example 2

[0031] Next, a second embodiment of the heat sealing device will be described with reference to the attached drawings. FIG. 4 is an explanatory diagram showing an outline of the configuration of a heater block included in the heat sealing device according to this embodiment, and FIG. 5 is an exploded perspective view showing an outline of the configuration of a heater block included in the heat sealing device according to this embodiment.

[0032] The heater block 11A according to this embodiment has a heat source 13 composed of a cartridge heater and a heat conductor 16 composed of a carbon graphite sheet. Since the cartridge heater and the carbon graphite sheet are the same as those in the first embodiment, the description thereof will be omitted. The difference between the heat sealing device 10A according to the second embodiment and the heat sealing device 10 according to the first embodiment is that the heater block 11A is configured to be divisible.

[0033] As shown in FIG. 4, the heater block 11A is composed of a first block body 20 provided with a heat source and a second block body 21 engaged with the first block body 20 and provided with a sealing surface 12. Between the first block body 20 and the second block body 21, clamping surfaces 22 facing each other are formed. As shown in FIG. 4 or FIG. 5, the first block body 20 is provided with a through hole 15 along the longitudinal direction at a predetermined position along the width direction and the height direction. As shown in FIG. 4, the heat source 13 and the heat conductor 16 are fitted into the through hole 15. A clamping surface 22 is formed in the front direction of the through hole 15. As shown in FIG. 4 or FIG. 5, the second block body 21 is provided with a seal surface 12 that protrudes in the front direction. A clamping surface 22 is formed in the depth direction of the seal surface 12. As shown in FIG. 4, a fixing bolt hole 26 is formed from the second block body 21 toward the first block body 20. By screwing a fixing bolt (not shown) into the fixing bolt hole 26, the second block body 21 is fixed to the first block body 20, and the heater block 11A is configured. At this time, a heat conductor 16A is sandwiched between the clamping surfaces of the first block body 20 and the second block body 21 that face each other. Here, the heat conductor 16A is preferably a carbon graphite sheet like the heat conductor 16. Since the carbon graphite sheet has high heat diffusivity along the plane direction with respect to the thickness direction, the heat of the first block body 20 heated by the heat source 13 quickly diffuses along the plane direction of the clamping surface 22 through the heat conductor 16A, and evenly warms the second block body 21 through the clamping surface 22. As a result, uneven distribution of heat on the seal surface 12 can be prevented. Note that the first block body 20 may be made of, for example, iron, and the second block body 21 provided with the seal surface 12 may be made of, for example, copper, that is, made of a metal having higher thermal conductivity than the first block body 20. Thereby, more heat can be diffused to the second block body 21 than to the first block body 20, and the manufacturing cost can be suppressed compared to configuring the entire heater block 11A with a metal having high thermal conductivity such as copper.

[0034] Also, a cartridge heater of the heat source 13 wrapped with a carbon graphite sheet that is the heat conductor 16 is fitted into the through hole 15, and the cartridge heater is pressed forward by a pressing bolt (not shown) screwed into the screw hole 17 and is in close contact with the inner surface on the clamping surface 22 side of the through hole 15. Since this configuration is the same as that of the first embodiment, the description thereof is omitted.

[0035] And, similar to the heat seal device 10 described in the first embodiment, a temperature sensor 18 composed of a thermocouple is disposed on the inner surface of the holding surface 22 side of the through hole 15 so as to contact the detection site with the carbon graphite sheet of the heat conductor 16. Thereby, heat is conducted from the heat source 13 to the carbon graphite sheet which is the heat conductor 16, the amount of diffused heat is detected, and a seal surface temperature signal based on the amount of heat is output from the temperature sensor 18 to the control unit. The control unit into which the seal surface temperature signal is input is configured to control the temperature of the heat source 13 based on the fed-back seal surface temperature signal and the heat source temperature signal of the heating element included in the heat source 13. Note that the thermocouple which is the temperature sensor 18 may be sandwiched together with the carbon graphite sheet of the heat conductor 16A by the holding surface 22. When sandwiched by the holding surface 22, the temperature in the vicinity of the seal surface 12 can be detected. Further, the temperature sensor 13 may be provided together with the heat source 13 and the holding surface 22 so as to simultaneously detect the temperatures of the heat source 13 and in the vicinity of the seal surface 12. In this case, the temperature control of the heat source 13 and the seal surface 12 can be performed more precisely.

[0036] The heater block 11A of the heat seal device 10A having the above configuration fits a cartridge heater of the heat source 13 to which a carbon graphite sheet as the heat conductor 16 is attached into the through hole 15 provided in the first block body 20, and further, the heat conductor 16A is sandwiched by the holding surface 22 formed between the first block body 20 and the second block body 21 having the seal surface 12, and then a fixing bolt (not shown) is screwed into the fixing bolt hole 26 of the first block body 20. Thereby, the second block body 21 is fixed to the first block body 20 by sandwiching the heat conductor 16A between the intermediate holding surfaces 22. As a result, in the integrally formed heater block 11A, since the carbon graphite sheet of the heat conductor 16 is adhered to the outer surface of the cartridge heater of the heat source 13, the heat of the heat source 13 is evenly diffused by the carbon graphite sheet of the heat conductor 16 along the inner surface of the through hole 15. Further, since the carbon graphite sheet of the heat conductor 16A sandwiched between the first block body 20 and the second block body 21 evenly diffuses and conducts heat to the second block body 21, the seal surface 12 can be evenly heated. And since the carbon graphite sheets of the heat conductors 16 and 16A have elasticity and there is no change in thermal conductivity even when they are crushed, the sheet itself can be compressed to fill the gap formed between the heat source 13 and the through hole 25, or there is no change in thermal conductivity even when it is sandwiched between the first block body and the second block body. As a result, there is no need to fill the inside of the through hole with a liquid such as thermal joint grease to fill the gap generated between the heat source 13 and the through hole 15 as in the conventional heat sealing device, so that liquid leakage from the through hole 15 can be prevented during the operation of the heat sealing device 10A.

[0037] Then, the temperature sensor 18 is installed on the heater block 11A so that the detection part of the temperature sensor 18 contacts the carbon graphite sheet of the heat conductor 16. Since the heat is evenly diffused over the entire carbon graphite sheets of the heat conductors 16 and 16A and the temperature sensor 18 is arranged on the seal surface 12 side of the heat source 13, the temperature sensor 18 can detect the temperature near the seal surface 12. The temperature detected by the temperature sensor 18 is converted into a seal surface temperature signal and output to the control unit. The control unit of the heat sealing device 10A compares the heat source temperature signal obtained from the temperature sensor built in the heat source 13 with the seal surface temperature signal obtained from the temperature sensor 18 in contact with the carbon graphite sheet, determines whether to heat the seal surface 12 or wait for heat dissipation from the seal surface 12, and performs a process of controlling the heat quantity of the heat source 13 or the temperature based on the heat quantity. As a result, the seal surface 12 of the heater block 11A can be maintained at a predetermined temperature optimal for welding the packaging material.

[0038] According to the heat sealing device 10A according to the second embodiment, a heat conductor 16 made of a carbon graphite sheet having high thermal conductivity is attached to the heat source 13, fitted into a through hole 15 provided in the first block body 20, pressed against the inner surface of the through hole, and a carbon graphite sheet of the heat conductor 16A is sandwiched between the first block body 20 and the second block body 21. Since the heat of the heat source 13 quickly diffuses along the surface direction of the carbon graphite sheet, the heat from the heat source 13 diffuses in the through hole 15, and further, the heat diffuses along the clamping surface 22 also inside the heater block 11A configured by engaging the second block body 21 with the first block body 20, so that the temperature distribution of the sealing surface 12 can be made uniform. Also, unlike the conventional heat pipe, the carbon graphite sheet does not break even when pressed and its thermal conductivity does not change due to its structure. Therefore, the carbon graphite sheet can be brought into close contact with the inner surface of the through hole 15. Moreover, when the heat sealing device 10A is operated, since there is no risk of breakage like a heat pipe, the durability can be improved while maintaining high thermal conductivity.

Example 3

[0039] Next, a third embodiment of the heat sealing device will be described with reference to the attached drawings. FIG. 6 is an explanatory diagram showing an outline of the configuration of a heater block included in the heat sealing device according to the present embodiment, and FIG. 7 is an exploded perspective view showing an outline of the configuration of a heater block included in the heat sealing device according to the present embodiment.

[0040] The heater block 11B of the heat sealing device 10B according to the present embodiment has a heat source 13 composed of a cartridge heater and a heat conductor 16B composed of a carbon graphite sheet. Since the cartridge heater and the carbon graphite sheet are the same as those in the first embodiment, the description thereof will be omitted. The difference between the heat-sealing device 10B according to the third embodiment and the heat-sealing device 10 according to the first embodiment is that the heater block 11B is configured to be separable.

[0041] As shown in FIG. 6, the heater block 11B is composed of a first block body 20 and a second block body 21 that engages with the first block body 20 and has a sealing surface 12. Between the first block body 20 and the second block body 21, clamping surfaces 22A facing each other are formed. As shown in FIG. 7, when viewed in cross-section along the width direction, the first block body 20 has a convex portion 23 protruding forward on the clamping surface 22a. On the top surface of the convex portion 23, as shown in FIG. 6 or FIG. 7, when viewed in cross-section along the width direction, a semi-circular concave groove 25a is formed along the longitudinal direction. As shown in FIG. 7, when viewed in cross-section along the width direction, the second block body 21 has a concave portion 24 recessed forward on the clamping surface 22b. On the bottom surface of the concave portion, as shown in FIG. 6 or FIG. 7, when viewed in cross-section along the width direction, a semi-circular concave portion 25b is formed along the longitudinal direction. By joining the first block body 20 and the second block body 21 facing each other across the clamping surface 22A and fitting the convex portion 23 formed on the clamping surface 22A into the concave portion 24, the semi-circular concave grooves 25a and 25b are formed into a through-hole 25 along the longitudinal direction. As shown in FIG. 6, a heat source 13 and a heat conductor 16B are fitted into the through-hole 25. In addition, in the heater block 11B, fixing bolt holes 26 are formed from the back to the front direction through the first block body 20 and the second block body 21. By screwing a fixing bolt (not shown) into the fixing bolt holes 26, the second block body 21 is fixed to the first block body 20, and the heater block 11A is integrally formed. Note that the first block body 20 may be made of, for example, iron, and the second block body 21 having the seal surface 12 may be made of, for example, copper, etc., and the second block body 21 may be made of a metal having higher thermal conductivity than the first block body 20. Thereby, more heat can be diffused from the first block body 20 to the second block body 21, and the manufacturing cost can be suppressed as compared with the case where the entire heater block 11B is made of a metal having high thermal conductivity such as copper.

[0042] As shown in FIG. 7, the heat source 13 and the heat conductor 16B sandwiched by the sandwiching surface 22A are such that the carbon graphite sheet as the heat conductor 16B is adhered around the outer surface of the cylindrical case of the cartridge heater as the heat source 13. Thereby, the cartridge heater wrapped with the carbon graphite sheet is fitted as the heat source 13 into the through hole 25 formed by the first block body 20 and the second block body 21. As described above, since the carbon graphite sheet has elasticity, by making the diameter of the heat source 13 around which the carbon graphite sheet is wound the same as the inner diameter of the through hole 25 or slightly larger than the inner diameter, the heat conductor 16B can be strongly adhered to the inner surface of the through hole 25.

[0043] And, similar to the heat sealing device 10 described in the first embodiment, a temperature sensor 18 composed of a thermocouple is arranged on the inner surface on the seal surface 12 side of the through hole 25 so as to contact the detection part with the carbon graphite sheet. Thereby, the amount of heat conducted from the heat source 13 to the carbon graphite sheet as the heat conductor 16B and diffused is detected, and a seal surface temperature signal based on the amount of heat is output from the temperature sensor 18 to the control part. The control part into which the seal surface temperature signal is input is configured to control the temperature of the heat source 13 based on the fed-back seal surface temperature signal and the heat source temperature signal of the heating element, the cartridge heater, which the heat source 13 has.

[0044] The heat-sealing device 10B having the above configuration fits a cartridge heater of a heat source 13 around which a carbon graphite sheet of a heat conductor 16B is wound into the concave groove 25a of the first block body 20 or the concave groove 25b of the second block body 21, fits the convex portion 23 of the first block body 20 into the concave portion 24 of the second block body 21, and integrally assembles the heater block 11B. Then, a fixing bolt is screwed into the fixing bolt hole 26 of the first block body 20, and the first block body 20 is fixed to the second block body 21 provided with the sealing surface 12. Thereby, the heat source 13 around which the heat conductor 16B is wound can be fitted into the through hole 25 formed by the concave groove 25a of the first block body 20 and the concave groove 25b of the second block body 21. Since a carbon graphite sheet is wound around and adhered to the outer surface of the cartridge heater, when the first block body 20 is fixed to the second block body 21 with a fixing bolt, the carbon graphite sheet is in close contact with the inner surface of the through hole 25. Thereby, the heat of the heat source 13 is evenly diffused along the inner surface of the through hole 25 by the carbon graphite sheet of the heat conductor 16B, and the heat conducted to the second block body 21 can evenly heat the sealing surface 12. And since the carbon graphite sheet has elasticity and there is no change in thermal conductivity even when it is crushed, the sheet itself can be compressed to fill the gap formed between the heat source 13 and the through hole 25. Therefore, there is no need to fill the inside of the through hole with a liquid such as thermal joint grease to fill the gap generated between the heat source 13 and the through hole 25 as in the conventional heat-sealing device, so that liquid leakage from the through hole 25 can be prevented during the operation of the heat-sealing device 10B.

[0045] Then, the temperature sensor 18 is installed on the heater block 11 such that the detection part of the temperature sensor 18 contacts the carbon graphite sheet. Since the heat is evenly diffused throughout the carbon graphite sheet and the temperature sensor 18 is arranged on the seal surface 12 side of the heat source 13, the temperature sensor 18 can detect the temperature near the seal surface 12. The temperature detected by the temperature sensor 18 is converted into a seal surface temperature signal and output to the control unit. The control unit of the heat sealing device 10B compares the heat source temperature signal obtained from the temperature sensor built in the heat source 13 with the seal surface temperature signal obtained from the temperature sensor 18 in contact with the carbon graphite sheet, determines whether to heat the seal surface 12 or wait for heat dissipation from the seal surface 12, and performs a process of controlling the heat quantity of the heat source 13 or the temperature based on the heat quantity. Thereby, the seal surface 12 of the heater block 11B can be maintained at a predetermined temperature optimal for welding the packaging material.

[0046] According to the heat sealing device 10B according to the third embodiment, the heat conductor 16B made of a carbon graphite sheet having high thermal conductivity is wound around the heat source 13 and fitted into the through hole 25 formed by the first block body 20 and the second block body 21. Since the heat of the heat source 13 quickly diffuses along the surface direction of the carbon graphite sheet, the temperature distribution of the seal surface 12 can be made uniform. Also, unlike the conventional heat pipe, the carbon graphite sheet does not break even when pressed and its thermal conductivity does not change due to its structure. Therefore, the carbon graphite sheet can be brought into close contact with the inner surface of the through hole 25. Moreover, when the heat sealing device 10A is operated, there is no risk of breakage like a heat pipe, so the durability can be improved while maintaining high thermal conductivity.

Example 4

[0047] Next, a fourth embodiment of the heat-sealing device will be described with reference to the accompanying drawings. FIG. 8 is an explanatory view showing an outline of the configuration of a heater block included in the heat-sealing device according to the present embodiment, and FIG. 9 is an exploded perspective view showing an outline of the configuration of the heater block included in the heat-sealing device according to the present embodiment.

[0048] The heater block 11C of the heat-sealing device 10C according to the present embodiment includes a heat source 13 composed of a cartridge heater and a heat conductor 16C composed of a carbon graphite sheet. Since the cartridge heater of the heat source 13 and the carbon graphite sheet of the heat conductor 16C are the same as those in the first embodiment, the description thereof will be omitted. The difference between the heat-sealing device 10C according to the fourth embodiment and the heat-sealing device 10A according to the second embodiment or the heat-sealing device 10B according to the third embodiment described above is the number of divisions of the heater block 11C.

[0049] As shown in FIG. 8 or FIG. 9, the heater block 11C is composed of a first block body 20, a second block body 21, and a third block body 27 having the seal surface 12. As shown in FIG. 8 or FIG. 9, when the first block body 20 is viewed in cross section along the width direction, a concave groove 25a that is recessed in a semicircular shape toward the back is formed along the longitudinal direction on the front vertical surface 28a. As shown in FIG. 8 or FIG. 9, when the second block body is viewed in cross section along the width direction, a concave groove 25b that is recessed in a semicircular shape toward the front is formed along the longitudinal direction on the back vertical surface 28b. Further, it has a clamping surface 22a on the front and a clamping surface 22b on the upper surface. As shown in FIG. 8 or FIG. 9, when the third block body is viewed in cross section along the width direction, it has a seal surface 12 on the front and a clamping surface 22c on the back side. When the opposing vertical surfaces 28a and 28b of the first block body 20 and the second block body 21 are joined to form a block body having a substantially L-shaped cross-sectional shape along the width direction, a through hole 25 along the longitudinal direction is formed from the concave groove 25a and the concave groove 25b. As shown in FIG. 8, the heat source 13 and the heat conductor 16C are fitted into the through hole 25. As shown in FIG. 8 or FIG. 9, when viewed in cross-section along the width direction, the third block body 27 is a substantially Γ-shaped block body facing a substantially L-shaped block body composed of the first block body 20 and the second block body 21, and has a clamping surface 22c on the surface facing the second block body 21. For each of the block bodies 20, 21, 27, when the vertical surfaces 28a, 28b are opposed and a fixing bolt (not shown) is screwed into the fixing bolt hole 26 to connect the first block body 20 and the third block body 27, a substantially L-shaped block body is formed. Then, when the clamping surfaces 22a, 22b, 22c are opposed and a fixing bolt (not shown) is screwed into the fixing bolt hole 26A to connect the second block body 21 and the third block body 27, a substantially Γ-shaped block body is formed. When these are integrally connected, a prismatic heater block 11C is formed. At this time, as will be described later, the vertical portion 16a of the heat conductor 16C is sandwiched between the clamping surfaces 22B formed between the second block body 21 and the third block body 27. Note that the third block body 27 may be made of a metal having higher thermal conductivity than the first block body 20 and the second block body 21, for example, the first block body 20 and the second block body 21 are made of iron, and the third block body 27 having the seal surface 12 is made of copper, for example. Thereby, more heat can be diffused to the third block body 27 than to the first block body 20 and the second block body 21, and the manufacturing cost can be suppressed as compared with the case where the entire heater block 11C is made of a metal having high thermal conductivity such as copper.

[0050] As shown in FIG. 8, the heat source 13 and the heat conductor 16C are attached such that the carbon graphite sheet, which is the heat conductor 16C, wraps around the outer surface of the cylindrical case of the cartridge heater, which is the heat source 13. The heat source configured in this way is fitted into the through-hole 25 formed by the first block body 20 and the second block body 21. Further, as shown in FIG. 9, the hanging portion 16a of the carbon graphite sheet of the heat conductor 16C after winding the cartridge heater of the heat source 13 is drawn out from the upper part of the through-hole 25 toward the third block body 27, and is further formed between the clamping surface 22c of the third block body 27 and the clamping surfaces 22a and 22b of the second block body 21, and is sandwiched and fixed by the clamping surface 22B that is bent in a substantially Γ shape when viewed in the width direction cross-section shown in FIG. 8. As described above, since the carbon graphite sheet of the heat conductor 16C has elasticity, by making the diameter of the heat source 13 around which the carbon graphite sheet is wound the same as or slightly larger than the inner diameter of the through-hole 25, the heat conductor 16C can be strongly adhered to the inner surface of the through-hole 25. Further, when the carbon graphite sheet is sandwiched by the clamping surface 22B formed between the second block body 21 and the third block body 27, it can be pressed against and strongly adhered to the clamping surfaces 22B of those block bodies 21 and 27. Thereby, the inside of the heater block 11C can be heated evenly, and uneven distribution of heat at the seal surface 12 can be prevented. Furthermore, since the carbon graphite sheet of the heat conductor 16C is composed of a single continuous sheet from the through-hole 25 to the clamping surface 22C along the surface direction, heat can be quickly and evenly conducted and diffused from the heat source 13 fitted in the through-hole 25 to the clamping surface 22B on the back side of the seal surface 12.

[0051] Then, as shown in FIG. 8 or FIG. 9, a temperature sensor 18 composed of a thermocouple is disposed on a carbon graphite sheet sandwiched between the sandwiching surfaces 22B on the back side of the seal surface 12 near the seal surface 12 in the third block body 27 so that the detection part is in contact therewith. As a result, heat is conducted from the heat source 13 to the carbon graphite sheet which is the heat conductor 16C, the diffused amount of heat is detected, and a seal surface temperature signal based on the amount of heat is output from the temperature sensor 18 to the control unit. The control unit into which the seal surface temperature signal is input is configured to control the temperature of the heat source 13 based on the fed-back seal surface temperature signal and the heat source temperature signal of the heating element included in the heat source 13.

[0052] In the heat sealing device 10C having the above-described configuration, a cartridge heater of the heat source 13 around which the carbon graphite sheet of the heat conductor 16C is wound is fitted into either the concave groove 25a of the first block body 20 or the concave groove 25b of the second block body 21, the first block body 20 and the second block body 21 are joined, and a block body assembled in a substantially L-shaped cross-sectional shape along the width direction is configured. Then, the vertical portion 16a of the carbon graphite sheet of the heat conductor 16C drawn out from the bent portion of the substantially L shape is disposed along the sandwiching surfaces 22a and 22b of the second block body 21. Here, when the substantially Γ-shaped third block body 27 opposed to the substantially L-shaped block body is joined, the vertical portion 16a of the heat conductor 16C can be sandwiched between the sandwiching surfaces 22B where the second block body 21 and the third block body 27 face each other. Here, when the fixing bolts connecting the respective block bodies 20, 21, and 27 are tightened, the carbon graphite sheet of the heat conductor 16C is wound around and adhered to the outer surface of the cartridge heater of the heat source 13. Therefore, the carbon graphite sheet is in close contact with the inner surface of the through hole 25, and the vertical portion 16a of the carbon graphite sheet is sandwiched between the second block body 21 and the third block body 27 and is in close contact with the sandwiching surface 22B. As a result, the heat of the heat source 13 can be evenly diffused by the carbon graphite sheet along the inner surface of the through hole 25, further evenly diffused to the sandwiching surface 22B, and conducted to the third block body 27 to evenly heat the seal surface 12. And since the carbon graphite sheet has elasticity and its thermal conductivity does not change even when it is crushed, the sheet itself can be compressed to fill the gap formed between the heat source 13 and the through hole 25. Therefore, unlike conventional heat seal devices, there is no need to fill the through hole with a liquid such as thermal joint grease to fill the gap generated between the heat source 13 and the through hole 25, so liquid leakage from the through hole 25 can be prevented during the operation of the heat seal device 10A.

[0053] Then, the temperature sensor 18 is installed on the heater block 11C so that the detection part of the temperature sensor 18 contacts the carbon graphite sheet. The carbon graphite sheet can evenly diffuse heat over the entire sheet, and the temperature sensor 18 is arranged on the clamping surface near the seal surface. Therefore, the temperature sensor 18 can detect the temperature near the seal surface 12. The temperature detected by the temperature sensor 18 is converted into a seal surface temperature signal and output to the control unit. The control unit of the heat seal device 10C compares the heat source temperature signal obtained from the temperature sensor built in the heat source 13 with the seal surface temperature signal obtained from the temperature sensor 18 in contact with the carbon graphite sheet, determines whether to heat the seal surface 12 or wait for heat dissipation from the seal surface 12, and performs a process of controlling the heat quantity of the heat source 13 or the temperature based on the heat quantity. Thereby, the seal surface 12 of the heater block 11C can be maintained at a predetermined temperature optimal for welding the packaging material.

[0054] According to the heat seal device 10C according to the fourth embodiment, the heat conductor 16C made of a carbon graphite sheet having high thermal conductivity is wound around the heat source 13, and the drawn hanging portion 16a is arranged in the vicinity of the seal surface 12 on the back side with a continuous single sheet. As a result, the heat of the heat source 13 quickly diffuses along the surface direction of the carbon graphite sheet, so that the heat can be quickly diffused and conducted from the through hole 25 side to the back side of the seal surface 12, and the temperature distribution of the seal surface 12 can be made uniform. Also, unlike a conventional heat pipe, a carbon graphite sheet does not change its thermal conductivity even when pressed and does not break. Therefore, the carbon graphite sheet can be adhered to the inner surface of the through hole 25. Moreover, when the heat sealing device 10C is operated, since there is no risk of breakage like a heat pipe, the durability can be improved while maintaining a high thermal conductivity.

Example 5

[0055] Furthermore, a fifth embodiment of the heat sealing device will be described with reference to the attached drawings. FIG. 10 is a right side view showing a schematic configuration of a heater block included in the heat sealing device according to this embodiment, FIG. 11 is a cross-sectional view taken along line A-A of FIG. 10, and FIG. 12 is an exploded perspective view showing a schematic configuration of a heater block included in the heat sealing device according to this embodiment.

[0056] The heat sealing device 10D described in the fifth embodiment includes a pair of heater blocks 11D and a heat source 13A that heats one or both of the heater blocks 11D. Since the configuration of the arm 14 and the like is the same as that of the first embodiment, the description thereof will be omitted.

[0057] As shown in FIG. 10, the heater block 11D is composed of a first block body 30 and a second block body 31 that engages with the first block body 30 and has a sealing surface 12. The first block body 30 and the second block body 31 are provided with clamping surfaces 32 facing each other. As shown in FIG. 10 or FIG. 12, the first block body 30 is configured as a prism. As shown in FIG. 10, the second block body 31 is configured in an L shape when viewed from the right side. The sealing surface 12 protrudes from the front side and the front end surface of the second block body, which is the outer surface of the rising part of the L shape. A heat conductor 16D made of a carbon graphite sheet is adhered to the clamping surface 32. As shown in Fig. 12, a heater block 11D is formed by sandwiching the carbon graphite sheet of the heat conductor 16D between the clamping surface 32a of the first block body 30 facing the clamping surface 32b of the second block body 31. And as shown in Fig. 11, the heat conductor 16D is arranged from the vertical surface on the seal surface 12 side to the bottom surface of the first block body 30. In the heater block 11D, fixing bolt holes 33 are formed from the bottom surface side of the second block body 31 toward the first block body 30. By screwing a fixing bolt 34 into the fixing bolt hole 33, the second block body 31 is fixed to the first block body 30. Note that the second block body 31 may be made of a metal having higher thermal conductivity than the first block body 30. Thereby, more heat can be diffused from the first block body 30 to the second block body 31.

[0058] As shown in Fig. 10, the heat source 13A has an induction coil 35 capable of forming a high-frequency electromagnetic field. When the induction coil 35 generates a high-frequency electromagnetic field, an induced current and an eddy current are generated in the first block body 30 within the region of the electromagnetic field, and the first block body 30 is heated based on the resistive loss energy related to the metal resistance of the first block body 30. Furthermore, the carbon graphite sheet used for the heat conductor 16D has high electrical conductivity in addition to high thermal conductivity, and has a shielding effect of reflecting or absorbing the high-frequency electromagnetic field generated by the induction coil 35. At the same time, induced current and eddy current are also generated in the carbon graphite sheet itself and it is heated in the same way as the first block body 30. Thereby, the carbon graphite sheet of the heat conductor 16D can confine the high-frequency electromagnetic field generated by the induction coil 35 to the first block body 30 and conduct the heat generated by electromagnetic induction based on the high-frequency electromagnetic field uniformly to the second block body 31.

[0059] A small-diameter through-hole is formed from the bottom surface side of the second block body 31 so that the detection part contacts a carbon graphite sheet adhered to the holding surface 32. By inserting a thermocouple that becomes the temperature sensor 18 into the small-diameter through-hole, the temperature of the carbon graphite sheet is measured at the detection part at the tip, and the temperature sensor 18 is configured to output a temperature signal based on the measured temperature to the control unit. And based on the induced current generated by the induction coil and the current value and resistive loss energy of the eddy current, the control unit can calculate the amount of thermal energy for heating the heat source side block body 31. By comparing the amount of heat based on the temperature signal measured by the temperature sensor 18 with the carbon graphite sheet and the amount of heat generated in the first block body or the second block body, the amount of current related to the induced current generated by the induction coil 35 is controlled, and also heat is dissipated from the second block body 31 to control the amount of heat generated in the entire heater block 11B and control the temperature of the seal surface 12.

[0060] The heat sealing device 10D having the above configuration sandwiches a carbon graphite sheet that is the heat conductor 16D between the opposing holding surfaces 32 of the first block body 30 and the second block body 31, and the first block body 30 and the second block body 31 are integrally connected to form a heater block 11D. Then, a holding bolt 34 is screwed into the fixing bolt hole 33 of the second block body 31, and the second block body 31 is fixed to the first block body 30. A heat source 13A having an induction coil 35 is disposed in the vicinity above the first block body 30, and the first block body 30 and the carbon graphite sheet of the heat conductor 16D disposed in the high-frequency electromagnetic field generated by the induction coil 35 generate heat based on the eddy current induced in the high-frequency electromagnetic field and the resistive loss energy of the carbon graphite sheet of the first block body 30 and the heat conductor 16C. The carbon graphite sheet of the heat conductor 16C clamped by the clamping surface 32 is in close contact with the second block body 31. Thereby, the heat of the first block body 30 is evenly diffused by the carbon graphite sheet along the clamping surface 32 of the second block body 31, and the heat conducted through the second block body 31 can evenly heat the sealing surface 12.

[0061] And the temperature sensor 18 is installed on the heater block 11D so that the detection part of the temperature sensor 18 contacts the carbon graphite sheet. Since the heat is evenly diffused over the entire carbon graphite sheet and the carbon graphite sheet is arranged near the sealing surface 12, the temperature sensor 18 can detect the temperature near the sealing surface 12. The temperature detected by the temperature sensor 18 is converted into a sealing surface temperature signal and output to the control unit. The control unit of the heat sealing device 10D calculates the amount of heat generated in the first block body 30 and the carbon graphite sheet based on the current value related to the induced current based on the high-frequency electromagnetic field generated by the induction coil 35 and the resistive loss energy of the first block body 30 and the carbon graphite sheet which is the heat conductor 16D, compares it with the amount of heat based on the sealing surface temperature signal obtained from the temperature sensor 18 in contact with the carbon graphite sheet of the heat conductor 16D, determines whether to heat the sealing surface 12 or wait for heat dissipation from the sealing surface 12, and performs a process of controlling the amount of heat of the heat source 13A or the temperature based on the amount of heat. Thereby, the sealing surface 12 of the heater block 11D can be maintained at a predetermined temperature optimal for welding the packaging material.

[0062] According to the heat-sealing device 10D according to the fifth embodiment, in order to equalize the temperature distribution of the sealing surface 12 of the heater block 11D, a heat conductor 16D made of a carbon graphite sheet having a high thermal conductivity is sandwiched between the first block body 30 and the second block body 31 on the clamping surface 32 formed therebetween. Then, the heat generated by the induction coil 35 installed near the upper part of the first block body 30 in the first block body 30 and the carbon graphite sheet which is the heat conductor 16D diffuses quickly along the surface direction of the carbon graphite sheet, so that the temperature distribution of the sealing surface 12 can be equalized. Also, unlike a conventional heat pipe, the carbon graphite sheet does not break even when pressed and its thermal conductivity does not change due to its structure. Therefore, the carbon graphite sheet can be bent and adhered to the mating surface 32 of the first block body 30 and the second block body 31. Moreover, when the heat-sealing device 10D is operated, since there is no risk of breakage like a heat pipe, the durability can be improved while maintaining a high thermal conductivity. Furthermore, a heating mechanism composed of a cartridge heater or the like is not provided inside the continuously operating heater block 11D, but is provided near the heater block 11D so as to generate heat inside the induction-heated heater block 11D. Thereby, the durability of the heater block 11D can be improved, and the replacement cycle of the heater block 11D can be extended. And, different from other embodiments, since through holes 15 and 25 for fitting a cartridge heater are not provided, the configuration of the heater block 11D can be simplified and the manufacturing cost can be suppressed.

Embodiment 6

[0063] Furthermore, a sixth embodiment of the heat-sealing device will be described with reference to the attached drawings. FIG. 13 is a right side view showing a schematic configuration of a heater block included in the heat-sealing device according to this embodiment, and FIG. 14 is an exploded perspective view showing a schematic configuration of a heater block included in the heat-sealing device according to this embodiment.

[0064] The heat-sealing device 10E described in the sixth embodiment includes a pair of heater blocks 11E and a heat source 13A that heats one or both of the heater blocks 11E. Since the arm 14 and other configurations are the same as those in the first embodiment, the description thereof will be omitted.

[0065] As shown in FIG. 13, the heater block 11E is composed of a first block body 30 having a sealing surface 12 and a second block body 31 that engages with the first block body 30. The first block body 30 and the second block body 31 are provided with clamping surfaces 32 facing each other. As shown in FIG. 13 or FIG. 14, the first block body 30 is configured to have a substantially Γ-shaped when viewed from the right side surface. A sealing surface 12 is formed to protrude on the front end surface of the first block body 30 that is the outer surface of the bent and hanging portion of the substantially Γ shape. A notch 36 is formed on the upper surface, and a heat insulating plate 37 is fitted into the notch 36. The heat insulating plate 37 may be a ceramic plate material, but is not limited thereto, and any material with a predetermined heat insulating effect may be used. Further, a clamping surface 32a is formed on the inner surface of the bend of the substantially Γ shape. As shown in FIG. 14, the second block body 31 is composed of a metal prism. Further, a clamping surface 32b and a clamping surface 32c are formed in connection on the front end surface and the upper surface on the sealing surface 12 side. A heat conductor 16E made of a carbon graphite sheet is disposed on the clamping surface 32 formed by opposing the clamping surface 32a of the first block body 30 and the clamping surfaces 32b and 32c of the second block body. A fixing bolt hole 33 is formed in the heater block 11E from the upper surface side of the first block body 30 toward the second block body 31. A fixing bolt 34 is screwed into the fixing bolt hole 33 to fix the first block body 30 to the second block body 31, and the heater block 11E is configured. Note that the first block body 30 may be made of a metal having higher thermal conductivity than the second block body 31. By doing so, more heat can be diffused to the first block body 30. Also, the second block body 31 may be made of a member having excellent heat storage properties. By doing so, the heat generated by the first block body 30 and the heat conductor 16E can be stored in the second block body 31, and when the first block body 30 cools down, the heat stored in the second block body 31 can be used to achieve thermal equilibrium, making it difficult for the first block body 30 with good thermal conductivity to cool down.

[0066] As shown in FIG. 13, the heat source 13A has an induction coil 35 capable of forming a high-frequency electromagnetic field. When the induction coil 35 generates a high-frequency electromagnetic field, an induced current and an eddy current are generated in the first block body 30 within the domain of the electromagnetic field, and the first block body 30 is heated based on the resistive loss energy related to the metal resistance of the first block body 30. Furthermore, the carbon graphite sheet used for the heat conductor 16E has high electrical conductivity in addition to high thermal conductivity, and has a shielding effect of reflecting or absorbing the high-frequency electromagnetic field generated by the induction coil 35. At the same time, induced current and eddy current are also generated in the carbon graphite sheet itself and it is heated in the same way as the first block body 30. As a result, the carbon graphite sheet can uniformly conduct the heat generated by electromagnetic induction based on the high-frequency electromagnetic field generated by the induction coil 35 to the first block body 31. Here, unlike the heater block described in the fifth embodiment, the carbon graphite sheet of the heat conductor 16E is configured to be closer to the heat source 13A. As a result, the skin effect related to the induced current is improved both in the first block body 30 and in the carbon graphite sheet of the heat conductor 16E, and heat can be generated at a portion where the magnetic flux density of the high-frequency electromagnetic field is high, so that the heating efficiency can be further increased. In addition, the heat conducted from the heated first block body and the carbon graphite sheet to the second block body can be expected to have a certain heat storage effect because the second block body is configured in a prismatic shape. Even when the thinly configured first block body and the carbon graphite sheet are cooled after sealing, an effect of making the sealing surface difficult to cool by receiving the heat balance from the second block body can be expected. On the other hand, a heat insulating plate 37 is fitted into the notch 36 of the first block body 30. As a result, the radiant heat radiated from the heated first block body 30 toward the heat source 13A can be heat-insulated and shielded by the heat insulating plate 37, and the heat source 13A can be prevented from being heated.

[0067] Also, although illustration in FIG. 13 or FIG. 4 is omitted, a thermocouple serving as a temperature sensor is sandwiched from the bottom surface side of the second block body 31 to the vicinity of the sealing surface 12 so that the detection part contacts the carbon graphite sheet of the heat conductor 16E adhered to the clamping surface 32. The detection part at the tip measures the temperature of the carbon graphite sheet of the heat conductor 16E near the back side of the sealing surface 12, and the temperature sensor is configured to output a temperature signal based on the measured temperature to the control part. Since the carbon graphite sheet has elasticity, the temperature sensor can be sandwiched without providing a small-diameter through hole as shown in the above embodiment. By omitting the small-diameter through hole, the convection of heat inside the first block body 30 or the second block body 31 is less likely to be inhibited by the small-diameter through hole, so that the heat conduction efficiency inside the first block body 30 or the second block body 31 can be increased. Then, based on the current value and the resistive loss energy of the induced current and the eddy current generated by the induction coil 35, the control part can calculate the amount of heat energy for heating the first block body 30. By comparing the amount of heat based on the temperature signal measured by the temperature sensor with the carbon graphite sheet and the amount of heat generated in the first block body 30 or the second block body 31, the amount of current related to the induced current generated by the induction coil 35 is controlled. Also, by dissipating heat from the first block body 30 or the second block body 31, the amount of heat generated by the entire heater block 11E is controlled, and the temperature of the seal surface 12 can be controlled.

[0068] The heat sealing device 10E having the above configuration sandwiches the carbon graphite sheet, which is the heat conductor 16E, between the opposing clamping surfaces 32 of the first block body 30 and the second block body 31, and screws the fixing bolt 34 into the fixing bolt hole 33 of the first block body 30, whereby the first block body 30 is fixed to the second block body 31. Thereby, the heater block 11E is configured. And a heat source 13A having an induction coil 35 is disposed near the upper part of the first block body 30, and the first block body 30 and the carbon graphite sheet of the heat conductor 16E disposed in the high-frequency electromagnetic field generated by the induction coil 35 generate heat based on the eddy current induced in the high-frequency electromagnetic field and the resistive loss energy of the first block body 30 and the carbon graphite sheet. Thereby, the first block body 30 is quickly heated, and the carbon graphite sheet quickly diffuses heat along the surface direction and reflects to the first block body 30, so that the seal surface 12 can be heated evenly.

[0069] And the detection part of the temperature sensor is sandwiched between the carbon graphite sheet and the clamping surface 32. Since the carbon graphite sheet diffuses heat evenly over the entire sheet and is disposed near the seal surface 12, the temperature sensor can easily detect the temperature near the seal surface 12. The temperature detected by the temperature sensor is converted into a seal surface temperature signal and output to the control unit. The control unit of the heat sealing device 10E calculates the amount of heat generated in the first block body 30 and the carbon graphite sheet of the heat conductor 16E based on the current value related to the induced current based on the high-frequency electromagnetic field generated by the induction coil 35 and the resistive loss energy, and compares it with the amount of heat based on the seal surface temperature signal obtained from the temperature sensor in contact with the carbon graphite sheet, determines whether to heat the seal surface 12 or wait for heat dissipation from the seal surface 12, and performs a process of controlling the amount of heat of the heat source 13A or the temperature based on the amount of heat. As a result, the seal surface 12 of the heater block 11E can maintain a predetermined temperature optimal for welding the packaging material.

[0070] According to the heat sealing device 10E according to the sixth embodiment, in order to equalize the temperature distribution of the seal surface 12 of the heater block 11E, a heat conductor 16E made of a carbon graphite sheet having high thermal conductivity is sandwiched between the first block body 30 and the second block body 31 so as to be sandwiched between the clamping surfaces 32 formed therebetween. Then, by receiving the induced current from the induction coil 35 installed near the upper part of the first block body 30 and arranging the first block body 30 and the heat conductor 16E in an electromagnetic field with a high magnetic flux density centered on the induction coil 35, due to the high skin effect, the heat generated in the carbon graphite sheet of the first block body 30 and the heat conductor 16E quickly diffuses along the surface direction of the carbon graphite sheet, so that the temperature distribution of the seal surface 12 can be equalized, and furthermore, the heat responsiveness of the seal surface 12 from the first block body 30 can be improved. Also, unlike a conventional heat pipe, the carbon graphite sheet does not break even when pressed and its thermal conductivity does not change due to its structure. Therefore, the carbon graphite sheet can be bent and adhered to the clamping surface 32 of the first block body 30 and the second block body 31. Moreover, when the heat sealing device 10E is operated, since there is no risk of breakage like a heat pipe, the durability can be improved while maintaining a high thermal conductivity. Furthermore, a heating mechanism composed of a cartridge heater or the like is not provided inside the continuously operating heater block 11E, but is provided in the vicinity of the heater block 11E so as to generate heat inside the induction-heated heater block 11E. By doing so, the durability of the heater block 11E can be improved, and the replacement cycle of the heater block 11E can be extended. And, different from other embodiments, since through holes 15 and 25 for fitting a cartridge heater are not provided, the configuration of the heater block 11E can be simplified, and the manufacturing cost can be suppressed.

[0071] According to the heat sealing devices 10, 10A, 10B, 10C, 10D, 10E according to the first to sixth embodiments, the carbon graphite sheets of the heat conductors 16, 16A, 16B, 16C, 16D, 16E are wound and adhered to the cartridge heaters of the heat sources 13, 13A, or the first block body 30 and the carbon graphite sheet are configured to be heated by the induction coil 35. Thereby, the structure can be simplified compared to the conventional heat pipe, and the number of parts can be reduced. In addition, since the carbon graphite sheet has flexibility and appropriate elasticity, it can be brought into close contact with the heat source 13, and further can be strongly adhered to the clamping surfaces 22, 32. Thereby, the heat of the heat sources 13, 13A can be conducted to the inner surfaces of the through holes 15, 25 or the clamping surfaces 22, 32 in wide surface contact, and the heat conductivity can be improved. And, since the heat conductivity is improved by the carbon graphite sheet so as to achieve uniform heat distribution on the seal surface 12 side, the heat uniformly diffused in the vicinity of the seal surface 12 can be detected by the temperature sensor 18 composed of a thermocouple, and by comparing with the heat supplied by the heat sources 13, 13A, the temperature control in the vicinity of the seal surface 12 of the heater blocks 11, 11A, 11B, 11C, 11D, 11E can be improved.

Description of Reference Numerals

[0072] 10, 10A, 10B, 10C, 10D, 10E... Heat sealing device 11, 11A, 11B, 11C, 11D, 11E… heater blocks, 12… sealing surface, 13, 13A… heat sources, 14… arm, 15… through hole, 16, 16A, 16B… heat conductors, 17… screw hole, 18… temperature sensor, 20, 30… first block bodies, 21, 31… second block bodies, 22, 32… clamping surfaces, 23… convex part, 24… concave part, 25… through hole, 25a, 25b… concave grooves, 26, 26A, 33… fixing bolt holes, 27… third block body, 34… fixing bolt, 35… induction coil, 36… notch, 37… heat insulating plate, 100… conventional heat sealing device, 110… heater block, 111… sealing surface, 112… heat source part, 113… heat diffusion part, 114… temperature sensor, B… bag.

Claims

1. A pair of heater blocks each made of a metal columnar member and each having a sealing surface facing each other; and a heat source for heating one or both of the pair of heater blocks, The heated heater block pair sandwiches and welds overlapping portions of a packaging material made of a heat-welding material, A heat sealing device characterized in that a thermal conductor made of a thin film or a flexible thin plate is arranged between the heat source and the sealing surface of the heater block along the longitudinal direction of the heater block over the length of the sealing surface.

2. forming through holes along a longitudinal direction at predetermined positions along a width direction and a height direction of the heater block; 2. The heat-sealing device according to claim 1, wherein the heat source is a columnar heat source having the heat conductor attached at least on the sealing surface side, the columnar heat source being fitted into the through hole.

3. dividing the heater block at a predetermined position in the width direction to form a first block body and a second block body that is engaged with the first block body and has the sealing surface; a through hole is formed along a longitudinal direction at a predetermined position along a width direction and a height direction of the first block body; 2. The heat-sealing apparatus according to claim 1, wherein the heat source has a columnar shape and is fitted into the through hole, and the heat conductor is sandwiched between a clamping surface formed between the first block body and the second block body.

4. dividing the heater block at a predetermined position in the width direction to form a first block body and a second block body that is engaged with the first block body and has the sealing surface; forming grooves facing each other along a longitudinal direction of the first block body and the second block body so that a hole along a longitudinal direction is formed between the first block body and the second block body when the first block body and the second block body are joined together; The heat conductor is attached to at least the sealing surface side of the heat source formed in a columnar shape; The heat source and the thermal conductor are fitted into the groove of either the first block body or the second block body, 2. The heat-sealing device according to claim 1, wherein the heat source and the heat conductor are disposed in the hole formed between the first block body and the second block body which are joined together.

5. dividing the heater block at a predetermined position in a width direction to form a first block body, a second block body, and a third block body having the sealing surface; forming grooves facing each other along a longitudinal direction of the first block body and the second block body so that a hole along a longitudinal direction is formed between the first block body and the second block body when the first block body and the second block body are joined together; The heat source formed in a columnar shape and the thermal conductor wound around the heat source are fitted into the groove, The heat source and the thermal conductor are disposed in the hole formed between the first block body and the second block body which are joined together, 2. The heat-sealing device according to claim 1, wherein the thermal conductor is pulled out and sandwiched on a sandwiching surface formed between the first block body or the second block body and the third block body, toward a side opposite to the sealing surface.

6. dividing the heater block at a predetermined position in the width direction to form a first block body and a second block body engaged with the first block body and having the sealing surface; an electric heat source capable of generating an eddy current in the heat source side block is disposed near the first block; The thermal conductor having electrical conductivity and high resistance is sandwiched between the first block body and the second block body by a sandwiching surface formed therebetween, 2. The heat-sealing device according to claim 1, wherein the heat conductor is inductively heated from the first block side when the electric heat source is energized.

7. dividing the heater block at a predetermined position in the width direction to form a first block body having the sealing surface and a second block body engaging with the first block body; an electric heat source capable of generating an eddy current in the first block is disposed near the first block; a heat insulating portion is provided between the electric heat source and an upper surface of the first block body; The thermal conductor having electrical conductivity and high resistance is sandwiched between the first block body and the second block body by a sandwiching surface formed therebetween, 2. The heat-sealing device according to claim 1, wherein the first block and the heat conductor are inductively heated when the electric heat source is energized.

8. 8. The heat-sealing device according to claim 7, wherein the heat insulating portion comprises a ceramic plate.

9. 8. The heat-sealing device according to claim 1, wherein the heat conductor is a carbon graphite sheet.

10. 8. The heat-sealing device according to claim 1, further comprising a temperature sensor disposed at a predetermined position in contact with the heat conductor.

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