JP6724426B2 - Seal material welding device - Google Patents

Description

The present invention relates to a seal material welding device that seals a container with a seal material using electromagnetic induction heating.

2. Description of the Related Art There is known a sealing material welding device that seals the mouth of a plastic container with a sealing material such as an aluminum film. In such a seal material welding device, a high-frequency current is passed through the coil to generate an electromagnetic field, and the metal seal material itself is heated by the induced current to be welded to the container mouth. In this device, the coil also generates heat due to high-frequency current, so the coil is formed of a hollow pipe, and cooling water is flowed into the pipe to cool it (Patent Document 1).

Japanese Patent No. 4479061

However, in the configuration of Patent Document 1, if the flow of cooling water is delayed due to some trouble, the coil may overheat and normal sealing may not be performed.

An object of the present invention is to suppress the occurrence of a sealing failure due to a defective circulation of a cooling medium in a sealing material welding device using high frequency induction heating.

The sealing material welding device of the present invention supplies a hollow coil provided in a sealing head, a high frequency generating means for supplying a high frequency current to the coil, and a container in which the sealing material is arranged above the mouth portion, below the sealing head. Container supply means, a raising and lowering means for moving the sealing head and the container relatively up and down, a supply pipe connected to the coil and supplying cooling air to the inside of the coil, and a coil connected to the coil to supply the cooling air to the coil. Equipped with a discharge pipe for discharging from the inside of the, and a cooling air supply means for supplying cooling air to the supply pipe, the coil is brought close to the seal material, and a high-frequency current is passed through the coil, so that the seal material is induced current. In the seal material welding device for heating and welding with, a ballast is provided between the high frequency generating means and the coil and connected to both ends of the coil, the supply pipe is branched and one is connected to one end of the coil, By arranging the other toward the ballast, the air for cooling is blown to the ballast, and at the same time, a detector that detects the flow state of the cooling air to at least one of the supply pipe and the discharge pipe, and the signal from this detector It is characterized by comprising a determining means for determining whether or not the distribution state is normal.

The detector is, for example, a pressure detector that detects the pressure of the cooling air .

The detector is, for example, a flow rate detector that detects the flow rate of cooling air .

According to the present invention, in a sealing material welding device using high frequency induction heating, it is possible to suppress the occurrence of a sealing failure due to a defective circulation of a cooling medium.

It is a top view showing arrangement of a system to which a sealing material welding device which is one embodiment of the present invention is applied. It is a sectional side view of the sealing material welding device of this embodiment. It is an expanded side sectional view of a sealing head and a hollow shaft. It is a schematic diagram which shows the structure of the coil provided in the sealing head.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing an arrangement of a system to which a sealing material welding device according to an embodiment of the present invention is applied.

The sealing material welding device 10 is, for example, a sealing device that seals the mouth of a resin container using a conductive sealing material such as a resin-coated aluminum foil (metal foil). The sealing material is preliminarily attached to the inner bottom surface of a resin cap, for example, and the sealing material welding device 10 is filled with a filling material such as mayonnaise on the upstream side (not shown) and the cap is capped. The containers to be manufactured are sequentially delivered from the supply wheel (container supply means) 12. That is, the resin container is supplied to the seal material welding device 10 in a state where the seal material is sandwiched between the resin cap and the mouth end of the resin container.

In the sealing material welding device 10, the sealing material is welded to the resin container using high-frequency induction heating, which will be described later, and then delivered to the reject wheel 14. The reject wheel 14 discharges (rejects) a container (product) determined to have a defective filling or a defective cap by a detection unit (not shown) to the chute 16. Further, the container that has not been discharged (rejected) to the chute 16 is transferred to the discharge wheel 18 and further transferred to the downstream process.

FIG. 2 is a side sectional view of the sealing material welding device 10 of the present embodiment. The seal material welding device 10 is, for example, a rotary type seal device, in which a fixed shaft portion 20 is arranged at the center, and a rotating portion 24 is rotatably supported around the fixed shaft portion 20 via various bearings 22A to 22D. The rotating portion 24 meshes with the gear 26 below and rotates at a predetermined speed.

A plurality of pedestals 28 on which the containers V are placed are arranged in the rotating portion 24 along the circumferential direction, and above each pedestal 28, a support member 30 for supporting the neck of the containers V placed on the pedestals 28 is provided. To be Further, above the support member 30, a sealing head 34 and a hollow shaft 36 that holds the sealing head 34 and extends upward are held by the rotating portion 24 so as to be movable up and down. The raising and lowering of the hollow shaft 36, that is, the sealing head 34, is performed by the engagement of the cam follower 36C provided on the hollow shaft 36 and the cam 20C provided on the fixed shaft portion 20 (elevating means), and a predetermined seal operation section (electromagnetic field). In the induction heating section), the tip of the sealing head 34 moves up and down so as to cover the cap C of the container V.

Above the fixed shaft portion 20 and the rotating portion 24, an upper rotating portion 42 that is rotatably held coaxially with the rotating portion 24 via a rotary joint 38 and a slip ring 40 is arranged. The upper rotating unit 42 is connected to the rotating unit 24 via a connecting member 44 and rotates integrally with the rotating unit 24.

A high-frequency oscillator (high-frequency generator) 46 is provided in the upper rotating portion 42 corresponding to each sealing head 34, and electric power is supplied through the slip ring 40 and the electric wire 41. Further, the high frequency oscillator 46 is supplied with cooling air (cooling medium) from a supply pipe 43 communicating with the rotary joint 38. The air (cooling medium) cools the high frequency oscillator 46, and then is discharged through the discharge pipe 45.

Inside the sealing head 34 provided at the lower end of the hollow shaft 36, a hollow conductive coil 50 is arranged. A high frequency current is supplied to the coil 50 from a high frequency oscillator 46 through an electric wire 52 wired inside the hollow shaft 36 and a ballast (current transformer) 53. The supply of the high frequency current to the coil 50 is performed in the sealing operation section, and the timing of starting the high frequency current supply is controlled based on, for example, a signal from an encoder (not shown) that detects the phase of the rotating unit 24.

One end of the coil 50 is connected from the rotary joint 38 to the supply pipe 54 arranged through the hollow shaft 36, and cooling air (cooling medium) is supplied into the hollow coil 50. The other end of the coil 50 is connected to a discharge pipe 56 arranged inside the hollow shaft 36, and the air passing through the coil 50 is discharged through the discharge pipe 56. The supply pipe 54 is constantly supplied with a cooling medium from a cooling medium supply means such as a blower (not shown). On the other hand, a cooling medium discharging means such as a blower is not provided on the discharge pipe 56 side, and the cooling medium is discharged through the discharge pipe 56 by the supply of the cooling medium from the supply pipe 54. However, a discharging means such as a blower may be provided. Good.

In the sealing head 34 and the hollow shaft 36 shown on the right side of FIG. 2, the configuration relating to the electric wiring of the coil 50 is mainly shown, and on the left side, the configuration relating to the cooling pipe of the coil 50 is shown mainly. The right side of FIG. 2 shows a state before the sealing head 34 is covered with the cap C of the container V, and the left side of FIG. 2 shows a state where the sealing head 34 is covered with the cap C of the container V.

FIG. 3 is an enlarged side sectional view of the sealing head 34 and the hollow shaft 36, and FIG. 4 schematically shows the configuration of the coil 50 of the present embodiment provided on the sealing head 34.

As shown in FIGS. 3 and 4, the tip of the supply pipe 54 is bifurcated, one pipe 54A is connected to one end of the hollow coil 50, and the other pipe 54B is used for cooling the ballast 53. The air is blown to cool the stabilizer 53. Further, as described with reference to FIG. 2, the exhaust pipe 56 is connected to the other end of the coil 50, and the cooling air supplied into the coil 50 passes through the hollow shaft 36. It is discharged through 56. At both ends of the coil 50, appropriate high-frequency current is supplied to the seal from the ballast 53 through the lead wires 52A and 52B, respectively.

A recess into which the cap C is inserted is formed at the tip of the sealing head 34, and the coil 50 is arranged so as to surround the recess. That is, an electromagnetic field is formed in the recess by the high-frequency current flowing in the coil 50, and an eddy current is generated in the conductive seal material loaded in the cap C inserted in the recess. As a result, the sealing material itself generates heat, and the resin coated on the sealing material is melted and welded to the mouth of the resin container V. At this time, the high-frequency current flows to heat the coil 50, but the coil 50 is cooled by the cooling air flowing through the coil 50. The air that has absorbed the heat from the coil 50 is discharged through the discharge pipe 56.

Further, in the present embodiment, the supply or discharge state of the cooling medium is checked in order to prevent a seal failure, and in order to judge or evaluate that the coil is properly cooled, the hollow shaft 36 of the discharge pipe 56 is A flow meter (detector) 58 is provided above (for example, near the upper rotating unit 42). The signal from the flow meter 58 is sent to the CPU (determination means) 60 of the seal material welding device 10 and processed. For example, when the flow rate (detection signal) is outside the predetermined permissible range, the CPU 60 determines that there is a high possibility of seal failure due to insufficient supply of the cooling medium, and corresponds to the corresponding sealing head 34. The high frequency oscillator 46 is stopped and the seal material welding device 10 is stopped to take measures so that the flow rate falls within a predetermined range. The time for which the high-frequency current is supplied to the coil 50 is predetermined, and once the supply of the high-frequency current is started, it is determined without being affected even if the rotation speed of the rotating unit 24 changes. A high-frequency current is supplied over time, and even if the operation of the sealing material welding device 10 is stopped and the rotation of the rotating portion 24 is stopped, the sealing head 34 whose flow rate is within the predetermined range is heated and welded as it is. To continue.

When the value of the flow rate returns to the normal value, the high frequency oscillator 46 of the corresponding sealing head 34 is operated to supply a high frequency current, and after performing the heat welding work for a predetermined time, the operation of the sealing material welding device 10 is performed. To resume. By doing so, it is possible to prevent the occurrence of defective sealing and reduce the number of rejected containers.

When it is determined that the value of the detected flow rate is out of the predetermined range, the high-frequency oscillator 46 of the corresponding sealing head is stopped, but the sealing material welding device 10 continues to operate and rejects the corresponding container downstream. The wheels 14 may discharge the chute 16. Further, even if it is determined that the value of the detected flow rate is outside the predetermined range, the high-frequency oscillator 46 of the corresponding sealing head does not stop and continues to operate as usual to reject the corresponding container downstream, The high frequency oscillator 46 may be controlled to stop when the value of the flow rate does not return to normal even if the operation is continued for a while.

As described above, according to the seal material welding device of the present embodiment, a product in which the defective flow of the cooling medium is detected and the occurrence of the defective seal is predicted, and the device may be stopped or the defective seal may occur accordingly By rejecting, it is possible to suppress the occurrence of products with defective sealing.

Further, in this embodiment, since the high-frequency oscillator, the ballast, and the coil are arranged in each sealing head, the current value from the high-frequency oscillator can be controlled by each sealing head, and the sealing head due to individual differences in parts such as the coil. It is possible to prevent variations in the finish of each seal.

In the present embodiment, the flow meter is used as a detector for detecting the supply/discharge state of the cooling medium, but a pressure gauge may be used instead of the flow meter, and the detector may be connected to the supply pipe side or the supply side. It may be provided on both the pipe and the discharge pipe. Also, different types of detectors can be used in combination.

Further, the seal material welding device according to the present embodiment is a rotary type, but may be a line type or an intermittent machine that operates intermittently. In addition, although a gas such as air is used as the cooling medium in the present embodiment, the present embodiment can be applied to a configuration that uses a liquid such as water, and the cooling medium may be circulated.

10 Seal material welding device 12 Supply wheel (container supply means)
20C cam (elevating means)
34 Sealing head 36C Cam follower (elevating means)
46 High-frequency oscillator (high-frequency generator)
50 coil 54 supply pipe 56 discharge pipe 58 flow meter (detector)
60 CPU (determination means)
C resin cap V resin container

Claims (3)

A hollow coil provided on the sealing head,
A high frequency generating means for supplying a high frequency current to the coil;
Container supply means for supplying a container in which the sealing material is arranged above the mouth portion to below the sealing head,
An elevating means for relatively elevating the sealing head and the container,
A supply pipe connected to the coil and supplying cooling air to the inside of the coil;
An exhaust pipe connected to the coil for exhausting the cooling air from the inside of the coil;
A cooling air supply means for supplying the cooling air to the supply pipe,
A sealing material welding device for heating and welding the sealing material with an induced current by causing the coil to approach the sealing material and applying a high-frequency current to the coil,
A ballast that is provided between the high-frequency generating means and the coil and is connected to both ends of the coil;
While branching the supply pipe and connecting one to one end of the coil, and arranging the other toward the ballast to blow cooling air to the ballast,
At least one of the supply pipe and the discharge pipe is provided with a detector that detects a circulation state of the cooling air , and a determination unit that determines whether or not the circulation state is normal from a signal from the detector. Sealing material welding device. The seal material welding device according to claim 1, wherein the detector is a pressure detector that detects the pressure of the cooling air . The seal material welding device according to claim 1, wherein the detector is a flow rate detector that detects a flow rate of the cooling air .

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