JP2014122048A - Seal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal device capable of uniformly heating a seal surface and cutting power consumption.SOLUTION: Heating means 28 and 30 for heating corresponding seal elements 10 and 12 are provided on support members 18 and 24 on which the seal elements 10 and 12 are arranged, respectively. The heating means 28 and 30 each include a heating element 34 obtained by molding an induction coil 40 capable of surrounding an outer wall of each of the seal elements 10 and 12 and wound around an elliptical shape with insulating resin 42. The seal elements 10 and 12 are inserted into hollow portions 34a formed in the heating elements 34 and vertically penetrating the heating elements 34 in a non-contact manner, respectively. Each of the heating elements 34 is configured to be displaceable between a first position at which a tip end side of the seal element 10 or 12 offset to a seal surface 10a or 12a faces inside the hollow portion 34a and a second position at which a proximal side thereof offset to an opposite side to the seal surface 10a or 12a faces inside the hollow portion 34a by urging an air cylinder 36 forward or backward.

Description

  The present invention relates to a sealing device for heating and sealing a film.

  In horizontal bag making and filling machines and other bag making and filling machines, horizontal seals are applied at predetermined intervals with a seal bar in the direction intersecting with the conveyance direction of the cylindrical film and cut to obtain bag-packed packages. In the apparatus, the seal bar is heated by a cartridge heater inserted into the seal bar. In such a heating method, temperature variation tends to occur in the longitudinal direction of the seal bar and the heating efficiency is inferior. For example, as described in Patent Document 1, the seal bar is obtained by induction heating using an induction coil. There have been proposals to heat.

  In the lateral sealing device disclosed in Patent Document 1, an induction coil is disposed in a groove formed on the base side of the seal bar so as to surround the side surface of the seal bar, and the induction coil is used as a heating source to make a magnetic metal seal bar. The induction heating.

JP 2004-10132 A

  The inventor of the present application has created a test apparatus using a test piece having the same form as the seal bar disclosed as an embodiment in Patent Document 1 for the practicality of the lateral seal apparatus disclosed in Patent Document 1, and will be described later. Verification was performed.

  In the test using the test apparatus, as described later, the temperature of the seal surface separated from the arrangement portion of the induction coil does not reach a general practical seal temperature, and the temperature of the surface of the arrangement portion of the induction coil is excessively heated. As a result. From this test result, in the embodiment of the conventional method, the temperature of the seal surface separated from the placement portion of the induction coil does not reach the practical seal temperature suitable for the horizontal seal in the horizontal bag making and filling machine, and the horizontal bag making. It was verified that it was difficult to put it into practical use with a filling machine.

  The present invention has been proposed in view of the above-described problems inherent in the sealing device according to the above-described prior art, and has been proposed to suitably solve this problem, and can achieve uniform heating of the sealing surface and reduce power consumption. An object is to provide a sealing device.

In order to overcome the above-mentioned problems and achieve the intended object, a sealing device according to the invention of claim 1 is provided:
In a sealing device that seals a film by moving a pair of opposed seal bodies close to and away from each other,
The seal body in which the tip having a seal surface is made of a magnetic material;
An induction coil that is disposed so as to surround the outer wall with a predetermined width in the opposing movement direction of the seal body with a gap from the outer wall in each seal body, and induction-heats the magnetic body facing the inside;
When the pair of seal bodies are moved close to each other, the induction coil is positioned at a second position separated from the first position on the distal end side of the seal body to the base side, and when the pair of seal bodies is moved apart, the induction coil is moved to the first position. A moving means for moving the seal body and the induction coil relatively so as to be positioned from the second position to the first position is provided.
According to the first aspect of the invention, since the relative position between the seal body and the induction coil can be displaced, the induction coil heats the seal surface of the seal body with the induction coil without the interference of the induction coil with the film. Therefore, the sealing surface can be heated more uniformly and efficiently in a shorter time than the conventional form. Thereby, since a sealing body is heated appropriately, power consumption can be reduced.

In the invention according to claim 2, the moving means includes an operating means for reciprocally moving the induction coil to the first position or the second position, and a driving means for operating the operating means. Features.
According to the second aspect of the present invention, the timing of displacement between the first position and the second position can be arbitrarily changed without depending on the approaching / separating operation of the seal body. It can be heated efficiently.

The invention according to claim 3 is characterized in that the support for supporting the induction coil is made of a non-magnetic material.
According to the invention which concerns on Claim 3, the magnetic force line which generate | occur | produces from an induction coil is not taken away by a support body, but a sealing body can be heated efficiently.

The invention according to claim 4 is characterized in that each of the sealing bodies has a non-magnetic body on the base side.
According to the invention of claim 4, since the volume of the portion to be induction-heated by the induction coil can be reduced, the heating time can be shortened and the induction coil can be reduced in size, further reducing power consumption. Can be reduced.

In the invention according to claim 5, the induction coil is controlled to be switched so that energization to the induction coil is turned on at the first position and energization to the induction coil is turned off at the second position. It is characterized by that.
According to the invention which concerns on Claim 5, power consumption can further be reduced by induction-heating only the front-end | tip part provided with the sealing surface.

In the invention which concerns on Claim 6, the outer wall surface of the sealing body which faces the said induction coil was formed in planar shape.
According to the invention which concerns on Claim 6, since the magnetic force line which generate | occur | produces from an induction coil can be permeate | transmitted efficiently to a sealing body, heating efficiency can be improved.

The invention according to claim 7 is characterized in that the outer wall of the sealing body is formed to be continuous in the circumferential direction.
According to the invention which concerns on Claim 7, since the magnetic force line which generate | occur | produces from an induction coil can be permeate | transmitted over the whole sealing body, the whole sealing body can be heated uniformly.

The invention according to claim 8 is characterized in that a ferromagnetic material is disposed outside the central portion in the longitudinal direction of the induction coil at a position close to the seal surface.
According to the eighth aspect of the present invention, it is possible to improve the heating efficiency by preventing the lines of magnetic force from being taken to the outside of the induction coil.

  According to the sealing device of the present invention, the sealing surface can be efficiently heated by induction heating as compared with the conventional embodiment, and the power consumption can be reduced.

It is a principal part front view of the horizontal sealing apparatus which concerns on Example 1 applied to the horizontal bag making filling machine. It is principal part sectional drawing of the horizontal sealing apparatus which concerns on Example 1, Comprising: (a) is the state which the sealing body separated, (b) is the state which clamped the film. (a) is a schematic perspective view which shows the 1st sealing body removed from the horizontal sealing apparatus from the sealing surface side, (b) shows the relationship between the 1st sealing body and heating body of the state of (a). It is a schematic view. It is a principal part front view of the horizontal sealing apparatus which concerns on Example 2. FIG. It is the schematic which shows the structure of the moving means of the horizontal sealing apparatus which concerns on Example 2. FIG. It is a principal part schematic side view which fractures | ruptures and shows the horizontal seal apparatus which concerns on Example 3. FIG. It is a schematic plan view which shows the structure of the moving means of the horizontal sealing apparatus which concerns on Example 3. FIG. The heating body which concerns on the example of a change is shown in the state which made the end surface by the side of a seal surface upward, (a) is a top view, (b) is a side view. It is the schematic which shows a test device, (a) is the figure seen from the front, (b) is the figure which fractured | ruptured the induction coil and was seen from the side, Comprising: The cross-sectional display of a coil is abbreviate | omitted .

  Next, the sealing device according to the present invention will be described below with reference to the accompanying drawings by way of preferred embodiments.

  1 and 2 exemplify a case where the present invention is applied to a horizontal sealing device of a horizontal bag making and filling machine known as Example 1 of the present invention. The horizontal sealing device is applied to a film F formed into a cylindrical shape. Articles M are supplied at predetermined intervals, and a lateral seal is applied to the film F which is supplied and conveyed at predetermined intervals in a direction crossing the film F conveyance direction at the front and rear positions of the articles M and M. , Configured to cut the film F.

  The horizontal sealing device includes a pair of sealing bodies 10 and 12 that are opposed to each other across the conveyance path of the film F. The first sealing body 10 on the upper side has a sealing surface 10 a that is a film with respect to the first holding member 14. The second seal body 12 on the lower side is disposed with the seal surface 12 a facing the film conveyance path with respect to the second holding member 16. Both seal bodies 10 and 12 are formed of a material made of carbon steel, carbon tool steel, or other magnetic body, and the seal bodies 10 and 12 are brought to a required temperature by induction heating by heating bodies 34 and 34 described later. Heated. Both seal bodies 10 and 12 are moved close to and away from each other by an operating mechanism (moving means) (not shown) and moved back and forth in the film transport direction, and the film F is sealed by the seal surfaces 10a and 12a heated to a required temperature when approaching. It is comprised so that a horizontal seal may be performed in the direction which cross | intersects a film conveyance direction by moving toward a film conveyance direction, pinching.

  As shown in FIG. 1, a pair of slide shafts 20 and 20 extend upwardly on a first support member 18 arranged so that the first seal body 10 protrudes downward, as shown in FIG. The slide shafts 20 and 20 are slidably inserted into the first holding member 14. A compression coil spring 22 as an urging means is wound around the outer periphery of each slide shaft 20 between the first holding member 14 and the first support member 18. On the other hand, the second support member 24 disposed so that the second seal body 12 protrudes upward is disposed and fixed to the second holding member 16, so that the pair of seal bodies 10, 12 At the time of meshing, the first seal body 10 is pushed upward together with the first support member 18 so as to be close to the first holding member 14, and the compression coil springs 22, 22 are compressed, and the compression coil springs 22, 22 are compressed. The film F is sandwiched between the first seal body 10 and the second seal body 12 with a required pressure by the urging force of 22, and the film F is laterally sealed.

  2 and 3, a through hole 10b is formed in the first seal body 10 in the vertical direction, and a knife 26 disposed on the first holding member 14 is formed in the through hole 10b. However, it is arranged so that the cutting edge can be moved up and down with the blade edge facing downward toward the seal surface 10a. When the film F is sandwiched between the seal bodies 10 and 12, the first seal body 10 is urged toward the first holding member 14, and the cutting edge of the knife 26 protrudes from the seal surface 10a so that the film F Is to be disconnected. The second seal body 12 is formed with a through-hole 12b in the vertical direction that allows the knife 26 to move forward and backward as a receiving groove that allows the knife 26 to protrude when engaged with the first seal body 10. The The outer wall surfaces of both the sealing bodies 10 and 12 are formed in a flat shape without irregularities over the entire circumference. In addition, the outer wall which defines the through-hole 10b of the seal bodies 10 and 12 is continuous in the circumferential direction.

  The supporting members 18 and 24 are provided with heating means 28 and 30 for heating the corresponding seal bodies 10 and 12, respectively. Since the configurations of the heating means 28 and 30 are vertically symmetrical, the first heating means 28 provided on the first support member 18 will be described, and the second heating means provided on the second support member 24 will be described. The same reference numerals are assigned to the same members 30 and the description thereof is omitted.

  The first heating means 28 includes a heating body 34 that is disposed so as to be movable integrally with the support body 32, and an air cylinder 36 that serves as a drive means for moving the support body 32 up and down. The air cylinder 36 is disposed on the first support member 18, and the support body 32 is disposed on a rod that extends below the air cylinder 36. The heating body 34 is supported on the support body 32 via heat insulating members 38 and 38 disposed at the left and right ends. The support 32 is formed of a material made of a nonmagnetic material having heat resistance such as stainless steel or heat resistant resin. In the first embodiment, the air cylinder 36 constitutes a moving unit.

  As shown in FIG. 2, the heating body 34 has a coil winding wound in an oval shape so as to have a predetermined winding width and a predetermined winding thickness in the vertical direction so as to surround the outer wall of the first seal body 10. The induction coil 40 is a resin-molded product molded with a heat-resistant resin 42. As shown in FIG. 3 (b), the first seal body 10 is formed in the outer wall of the hollow portion 34a formed in the heating body 34. The outer edge is inserted in a non-contact manner with a predetermined gap. Then, by supplying a current having a predetermined frequency to the induction coil 40, an eddy current is generated in the first seal body 10, which is a magnetic body, by the magnetic force lines generated from the induction coil 40, so that the seal body 10 self-heats. To do. Thereby, the 1st sealing body 10 is heated in a short time, and the whole area of a longitudinal direction is heated substantially uniformly. The vertical dimension (winding width) of the heating body 34 in the opposite movement direction of the sealing bodies 10 and 12 is set shorter than the vertical dimension of the first sealing body 10, and the heating body 34 is shown in FIG. As shown in FIG. 1, the lower edge of the induction coil 40 is positioned below the seal surface 10a of the first seal body 10, and the tip end side of the seal body 10 is faced in the hollow portion 34a of the heating body 34, so that the seal body The first position where the tip end side is induction heated surrounding the outer wall of 10 and the base side which is biased to the side opposite to the seal surface 10a as shown in FIG. It is comprised so that it may displace to the 2nd position which surrounds the outer wall of the body 10 and carries out induction heating of the base side.

  The displacement of the heating body 34 to the first position and the second position can be performed by switching the operation of each air cylinder 36 in synchronism with the close and separate movement of the seal bodies 10 and 12. That is, in the first embodiment, as shown in FIG. 2 (a), in the separated position where the pair of seal bodies 10 and 12 are separated from each other, the heating bodies 34 and 34 are set to the first position with respect to the seal bodies 10 and 12, Further, the air is so arranged that the heating bodies 34, 34 are displaced to the second position shown in FIG. 2B with respect to the sealing bodies 10, 12 in accordance with the timing when the sealing bodies 10, 12 are close to each other and sandwich the film F. A cylinder 36 extends and contracts the rod. Further, the air cylinder 36 is operated so that the heating bodies 34 and 34 return to the first position at a predetermined timing when the sealing bodies 10 and 12 having laterally sealed the film F release the nipping of the film F and are separated. To do. In this manner, the heating body 34 and the first seal body 10 can be relatively moved in the vertical direction.

  In the horizontal sealing device of the first embodiment, the front end portions of the sealing bodies 10 and 12 having the sealing surfaces 10a and 12a can be induction-heated by the heating bodies 34 and 34. Therefore, the sealing surfaces 10a and 12a Efficient and more uniform heating can be achieved up to the practical seal temperature. In addition, even when heat is temporarily removed from the sealing surfaces 10a and 12a when the film F is sealed with the film F interposed therebetween, the bases of the sealing bodies 10 and 12 are heated by the heating bodies 34 and 34 at the second position. Therefore, the temperature drop of the seal surfaces 10a and 12a can be suppressed, and the temperature fluctuation of the seal surfaces 10a and 12a can be kept within the practical seal temperature range. Further, when the film F is sandwiched between the sealing bodies 10 and 12, the heating bodies 34 and 34 are retracted so as to be separated from the sealing surfaces 10a and 12a. There is no interference or pressing of the article M. In addition, since the heating body 34 is moved by the air cylinder 36, the operation mechanism can be simplified and the operation timing can be set appropriately, and the distal end side and the base side can be appropriately and appropriately heated at each position. can do.

  Here, in the horizontal sealing device, the sealing period in one packaging cycle (from the time when the sealing bodies 10 and 12 start to contact the film F supplied with the article M until the film F is released and separated from the film F) The remaining period of one packaging cycle excluding the period is set longer, and the heating period on the distal end side of the sealing bodies 10 and 12 by the heating bodies 34 and 34 is the heating on the base side. Since the period is longer than the period, the seal surfaces 10a and 12a can be heated and maintained at an appropriate temperature of the seal. Further, since the heating body 34 moves in a non-contact manner with the seal bodies 10 and 12 along the outer walls of the seal bodies 10 and 12 so as to be displaced to the first position and the second position, It can suppress that the heating body 34 is heated too much. In addition, since the heating body 34 is moved by the air cylinder 36 that is driven separately from the approaching and separating movement of the seal bodies 10 and 12, the heating body 34 is changed to the first by changing the operation timing of the air cylinder 36. The period that is the position and the period that is the second position can be varied. That is, the period during which the heating body 34 is in the first position can be appropriately adjusted within a range in which the heating body 34 does not interfere with the film F in relation to the outer edge of the film F supplied with the article M. .

  Moreover, the outer wall surface which becomes the opposing surface in the seal bodies 10 and 12 surrounded by the induction coil 40 in the heating body 34 is formed in a flat shape without unevenness as shown in FIG. Since permeation to the sealing bodies 10 and 12 is brought about, the entire area of the sealing surfaces 10a and 12a can be heated more uniformly and efficiently, and power consumption can be further reduced. Furthermore, the outer walls of the seal bodies 10 and 12 have a region facing the hollow portion 34a of the heating body 34 at the first position in the circumferential direction over substantially the entire length in the vertical direction. Can be transmitted through the entire seal bodies 10 and 12, so that the entire areas of the seal surfaces 10a and 12a can be heated more uniformly. Since the support body 32 is made of a non-magnetic material, the magnetic field lines generated from the induction coil 40 are not lost to the support body 32, and the seal bodies 10 and 12 are efficiently heated in a shorter time. Energy saving effect.

  Here, in the conventional system in which a round bar cartridge heater is embedded in the seal body, it is difficult to make the seal body thinner than the heater diameter in relation to the heater diameter. When the seal width L of the seal surface 10a shown in FIG. 3 (a) is narrowed, the seal surface side of the seal body is tapered so as to secure a thickness for arranging the cartridge heater. For this reason, since the distance from the position where the cartridge heater is disposed to the seal surface becomes longer, the heating conditions in the cartridge heater change. On the other hand, in the first embodiment, since the sealing surface can be induction heated by the heating body 34 provided outside the sealing bodies 10 and 12, a space for arranging the heating means on the sealing bodies 10 and 12 is ensured. The sealing bodies 10 and 12 can be made thinner, and the heating efficiency can be further improved as the seal width is reduced. Further, the seal bodies 10 and 12 can be reduced in size and weight, and the operation load of the apparatus can be reduced.

  4 and 5 show a main part of the lateral seal device according to the second embodiment in which a mechanical linkage mechanism 44 and a cam mechanism 46 are combined as an operating means constituting the moving means of the heating body 34. FIG. . Since the basic configuration of the operating means of the first heating means 28 and the second heating means 30 is vertically symmetric, the operating means on the first heating means side will be described, and the operating means on the second heating means side will be described. The same reference numerals are assigned to the same members, and descriptions thereof are omitted.

  In the lateral sealing device of the second embodiment, the support 32 is supported by the attachment member 48 disposed on the first support member 18 so as to be slidable in the vertical direction, and the support 32 is pulled against the attachment member 48. Energized by the coil spring 50, the heating body 34 is in the first position where the distal end side of the sealing body 10 faces the hollow portion 34a so that the lower edge of the induction coil 40 is positioned below the sealing surface 10a. Is positioned (see FIG. 4). As shown in FIG. 5, the cam mechanism 46 includes a disc cam 52 provided on a rotating shaft of a drive mechanism that moves the pair of seal bodies 10 and 12 close to and away from each other, and a cam surface of the disc cam 52. And a follower 54 that moves. The linkage mechanism 44 includes a rotating lever 58 whose one end in the longitudinal direction is pivotally supported by the apparatus frame 56 and a wire 60 having one end attached to the other end in the longitudinal direction of the rotating lever 58. And the other end of the wire 60 is attached to the support 32. The follower 54 is pivotally supported at an intermediate position of the rotation lever 58, and the rotation lever 58 swings as the disc cam 52 rotates in synchronization with the close and separation movement of the pair of seal bodies 10 and 12. By moving, the heating body 34 arranged on the support body 32 via the wire 60 is displaced to the first position and the second position where the base side of the seal bodies 10 and 12 is faced in the hollow portion 34a. To do. The disc cam 52 is configured to change the shape of the cam surface on which the follower 54 rolls by displacing two overlapping plate cams in the circumferential direction around the rotation center. The timing at which the heating element 34 is displaced to the first position and the second position can be varied by changing the shape of the cam surface. In the second embodiment, a drive mechanism that moves the seal bodies 10 and 12 close to and away from each other constitutes a drive unit.

  In the horizontal sealing device of the second embodiment, the moving means for the heating bodies 34 and 34 are supported by a drive mechanism that moves the pair of sealing bodies 10 and 12 close to and away from each other via the mechanical linkage mechanism 44 and the cam mechanism 46. Since the bodies 32 are connected to each other, in addition to the function and effect produced by the lateral seal device of the first embodiment, the heating bodies 34 and 34 are precisely matched with the interlocking timing with the approaching and separating movement timing of the seal bodies 10 and 12. Can be reliably displaced between the first position and the second position.

  FIGS. 6 and 7 show the main part of the lateral seal device according to the third embodiment using a gear coupling mechanism (actuating means) 62 and a motor (driving means) 64 as moving means for the heating body 34. The basic structure of the moving means of the first heating means 28 and the second heating means 30 is vertically symmetrical, and only the moving means on the first heating means side is shown in FIGS.

  In the lateral seal device of the third embodiment, the movable body 70 is supported on the casing 66 disposed on the first support member 18 so as to be slidable in the vertical direction along a plurality of slide shafts 68 and 68 extending in the vertical direction. In addition, the support body 32 is connected to the moving body 70 via a bracket 72. An operating gear 74 is rotatably supported on the casing 66, and a follower 74 a that is pivotally supported at an eccentric position of the operating gear 74 is freely rollable into a long groove 70 a that extends in the lateral direction of the moving body 70. positioned. A drive shaft 76 that is rotationally driven by a motor 64 is rotatably supported on the casing 66, and the rotation of the drive shaft 76 is transmitted via a transmission mechanism 82 including a plurality of gears 78 and link rods 80. To the operating gear 74. With these configurations, by driving and controlling the motor 64 in synchronism with the approach and separation of the pair of seal bodies 10 and 12, the moving body 70 that engages the follower 74a of the operating gear 74 moves in the vertical direction. The heating body 34 is displaced together with the support body 32 so as to be in the first position and the second position.

  In the horizontal sealing device of the third embodiment, the heating body 34 is moved by the motor 64. Therefore, similarly to the horizontal sealing device of the first embodiment, the heating body 34 is changed by changing the set value of the control timing of the motor 64. It is possible to vary the period in which is the first position and the period in which the second position is. In addition, even during high-speed operation, the heating element 34 can be displaced between the first position and the second position in precise synchronization with the horizontal sealing operation.

  Next, the temperature detection means 86 provided in the horizontal sealing apparatus of Examples 1 to 3 will be described. The temperature detection means 86 is disposed on each of the first seal body 10 and the second seal body 12, but since the basic configuration of each temperature detection means 86 is the same, the first seal body 10 is the same. The temperature detection means 86 disposed in the second seal body 12 will be described, and the same reference numerals will be assigned to the same members and the description thereof will be omitted.

  As shown in FIGS. 1 and 4, the first support member 18 is supported by a temperature detecting means 86 composed of a thermosensitive element such as a thermocouple via a support piece 84. A detection portion 86a, which is inserted straight from the base end side into the seal body 10 from the support piece 84 so as to be orthogonal to the seal surface 10a, is provided close to the seal surface 10a. Is located. The temperature detecting means 86 is disposed on both sides of the first seal body 10 in the longitudinal direction, and is configured to be able to detect temperatures at both ends in the longitudinal direction of the seal body 10. The lateral seal device is configured to maintain the seal surface 10a at a practical seal temperature by controlling the supply of current to the induction coil 40 based on the temperature detected by each temperature detection means 86.

(About test examples)
Create a test piece with a narrow base extending from the end surface opposite to the seal surface at the tip with the seal surface, and coil winding with a predetermined width in the vertical and width directions so as to surround the base 9 (a) and 9 (b), in which an induction coil wound with a coil was placed, was prepared, and each temperature of the seal surface and the surface of the placement portion of the induction coil was measured in a stationary state. For temperature measurement, a thermocouple is used, and the three parts indicated by A, B, and C in FIG. 9 separated in the longitudinal direction at the center in the vertical direction at the base of the test piece, and the figure separated in the longitudinal direction of the seal surface at the tip. The measurement was performed at two points indicated by D and E in FIG.

  In this test, the temperature of the seal surfaces (D, E) separated from the placement portion of the induction coil does not reach about 200 ° C. to 250 ° C., which is a typical practical seal temperature, and before that, the placement of the induction coil The temperature of the part surface (A, B, C) exceeded the “JIS insulation class F type (heat resistance 155 ° C.)” which is an allowable temperature value at which dielectric breakdown of a general induction coil occurs. From this test result, the lines of magnetic force generated by the induction coil are not generated from the induction coil arrangement part to the seal surface, but are generated mainly toward the inside of the induction coil arrangement part. It is assumed that the sealing surface is heated by heat transfer from the heated portion by being heated.

  Therefore, using the test piece, the temperature of the seal surface (D, E) is measured in a stationary state in which the induction coil is disposed so as to surround the tip end portion by positioning the edge of the induction coil to the outside of the seal surface. As a result, it was possible to heat to about 200 ° C. to 250 ° C., which is a general practical seal temperature. That is, it was confirmed that the sealing surface could not be heated and maintained at the practical sealing temperature unless the induction coil was arranged near the sealing surface. Thus, in the conventional form, the induction surface is heated to a temperature at which dielectric breakdown occurs without the seal surface reaching the practical seal temperature, whereas it is close to the seal surface as in the embodiment of the present invention. By inductively heating the tip with the arranged induction coil, it was verified that the sealing surface can be heated to a practical sealing temperature, and that it can be implemented in a practical range with a horizontal bag making and filling machine.

(Example of change)
The present invention is not limited to the configuration of the examples, and various embodiments can be adopted within the scope of the gist of the present invention. For example, the following modifications can be made.
(1) The seal bodies 10 and 12 are made of a magnetic material by a predetermined dimension (for example, the same length as the length of the heating body 34 facing the seal bodies 10 and 12 in the opposite direction) provided with the seal surfaces 10a and 12a. In addition, a configuration in which the base portion is made of a nonmagnetic material can be employed. According to this embodiment, since the volume of the sealing bodies 10 and 12 that is induction-heated by the heating body 34 can be reduced, the heating body 34 can be downsized and the power consumption can be reduced. Further, when the seal bodies 10 and 12 move close to each other, the energization to the induction coil 40 is switched from the ON state to the OFF state, and when the seal bodies 10 and 12 move away from each other, the energization to the induction coil 40 is turned off. By performing switching control so as to switch from the state to the ON state, power consumption can be further reduced, and a large energy saving effect can be expected. In the configurations of the first to third embodiments as well, the energization of the induction coil 40 may be ON / OFF controlled in accordance with the proximity and separation of the seal bodies 10 and 12.
(2) In the induction coil 40 shown in the first to third embodiments, the entire seal surfaces 10a and 12a can be heated substantially uniformly within the range of the practical seal temperature, but both ends in the longitudinal direction are sealed bodies. Since both sides in the thickness direction 10 and 12 and the end face in the longitudinal direction are surrounded, the vicinity of both ends in the longitudinal direction of the seal bodies 10 and 12 tends to be heated most. Therefore, as shown in FIGS. 8A and 8B, the shield material 88 formed of a material made of a ferromagnetic material such as ferrite is moved toward the seal surface outside the central portion of the induction coil 40 in the longitudinal direction. It is most preferable to employ a configuration that is arranged at different positions. According to this configuration, it is possible to prevent the lines of magnetic force generated from the central portion in the longitudinal direction of the induction coil 40 from being taken away to the outside, and the sealing bodies 10 and 12 are applied to the entire center from both ends in the longitudinal direction. Inductive heating can be performed more evenly and uniformly.
(3) The actuating means constituting the moving means of the heating body 34 may employ a link mechanism or other various linkage mechanisms instead of a mechanism combining the linkage mechanism 44 and the cam mechanism 46 or the gear linkage mechanism 62. . Further, the drive means for operating various linkage mechanisms may be a linear actuator such as a cylinder.
(4) The support 32 is preferably made of a non-magnetic material, but may be made of a magnetic material.
(5) In Embodiments 1 to 3, the case where the film F is sandwiched and moved by the seal bodies 10 and 12 is illustrated as an example, but various packaging machines such as a vertical bag making and filling machine are used. In addition, the sealing bodies 10 and 12 can be applied as sealing devices such as various packaging machines that can move the sealing surfaces 10a and 12a toward the film F so as to face each other.

DESCRIPTION OF SYMBOLS 10 1st sealing body 10a Sealing surface 12 2nd sealing body 12a Sealing surface 32 Support body 36 Air cylinder (moving means, drive means)
40 induction coil 44 linkage mechanism (actuating means)
46 Cam mechanism (actuating means)
62 Gear linkage mechanism (actuating means)
64 motor (drive means)
88 Shielding material (ferromagnetic material)
F film

Claims (8)

In the sealing device that seals the film (F) by moving the pair of opposed seal bodies (10, 12) close to and away from each other,
The sealing body (10, 12) in which the tip portion provided with the sealing surface (10a, 12a) is made of a magnetic material;
An induction coil that is disposed so as to surround the outer wall with a predetermined width in the opposing movement direction of the seal body (10, 12) with a gap from the outer wall in each seal body (10, 12), and induction-heats the magnetic body facing the inside (40),
When the pair of seal bodies (10, 12) are moved close to each other, the induction coil (40) is positioned at a second position spaced from the first position on the distal end side of the seal body (10, 12) to the base side, and When the seal body (10, 12) is moved apart, the seal body (10, 12) and the induction coil (40) are relatively moved so that the induction coil (40) is positioned from the second position to the first position. A sealing device comprising a moving means (36, 44, 46, 62, 64).   The moving means operates the operating means (44, 46, 62) for reciprocating the induction coil (40) to the first position or the second position, and the operating means (44, 46, 62). The sealing device according to claim 1, further comprising a driving means (64) for performing the operation.   The sealing device according to claim 1 or 2, wherein the support (32) for supporting the induction coil (40) is made of a non-magnetic material.   The sealing device according to any one of claims 1 to 3, wherein each of the sealing bodies (10, 12) has a base portion made of a nonmagnetic material.   The induction coil (40) is controlled to be switched so that energization to the induction coil (40) is turned on at the first position and energization to the induction coil (40) is turned off at the second position. The sealing device according to any one of claims 1 to 4, wherein   The sealing device according to any one of claims 1 to 5, wherein an outer wall surface of the sealing body (10, 12) facing the induction coil (40) is formed in a flat shape.   The sealing device according to any one of claims 1 to 6, wherein an outer wall of the seal body (10, 12) is formed to be continuous in a circumferential direction.   The sealing device according to any one of claims 1 to 7, wherein a ferromagnetic body is disposed at a position close to the sealing surface side outside the central portion in the longitudinal direction of the induction coil (40). .

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