JP5790209B2 - Capping device - Google Patents

Description

  The present invention relates to a capping device that performs tightening by covering a mouth of a container and rotating the cap, and more particularly, to a capping device that performs capping while holding a container made of a soft material such as a PET container. Is.

  2. Description of the Related Art Conventionally, a capping device that performs capping by gripping a body portion of a resin container such as a PET bottle with a gripper and rotating the cap held by a capping head over the mouth portion of the container has been widely known. (For example, refer to Patent Document 1 or Patent Document 2).

  In Patent Document 1, a star wheel that is detachably fixed to the upper side of the container table and has a plurality of semicircular concave gripping surfaces in the periphery, and is provided at a right angle in the radial direction on the lower periphery of the container table. A gripping body rotatably supported on a horizontal axis and having a semicircular concave gripping surface, a guide rail that engages with the gripping body and rotates the gripping body, and two semicircles of the star wheel and the gripping body An arc-shaped elastic body fixed to the gripping surface of the recess, and when the gripping body faces the star wheel, the elastic body of each recess forms a concentric circle slightly smaller than the outer diameter of the container, A container gripping device for gripping a container thereby is described.

  Further, Patent Document 2 includes a star wheel provided with a plurality of pockets for accommodating containers, and a guide portion provided on the outer periphery of the star wheel to prevent the containers from falling off the conveyance path. The buffer is provided on the inner surface of the pocket with an elastic body and comes into contact with the body of the container accommodated in the pocket, and the guide is configured with an elastic body and the container accommodated in the pocket is a star wheel. A capping machine is provided that is provided with a cushion member that is pressed in the direction of the rotation axis and contacts the body portion. In the invention described in Patent Document 2, when capping, the container can be pressed from the outside to prevent the container from rotating.

JP-A-8-26389 JP-A-8-72986

  When the screw cap is wound around the container as in the inventions described in the above cited references, the container is gripped by the star wheel and the gripper by the gripping body or the cushion member. There was a problem such as waking up.

  The present invention has been made in order to solve the above-described problems, and includes a transport unit that transports a container, a holding unit that holds the container, and a cap that is wound around the mouth of the container that the holding unit holds. A capping device comprising a capping head, comprising: a control means for controlling a holding force for holding the container by the holding means when the cap is tightened by the capping head, and the mouth portion of the container when the cap is tightened. The holding means holds the container with the first holding force until the top surface comes into contact with the seal portion inside the cap, and after the mouth top surface of the container comes into contact with the seal portion inside the cap, the holding means The container is held by a second holding force having a load larger than that of the first holding force.

  According to a second aspect of the present invention, in the first aspect of the invention, the switching from the first holding force of the holding means to the second holding force by the control means is performed by calculating the number of screw turns of the cap of the capping head. It is characterized by doing.

  When the cap is tightened on the container mouth, while the container mouth is not sealed, it is held with the first holding force which is a weak holding force, and after the mouth of the container is sealed, Since the second holding force having a load larger than the first holding force is used, there is no possibility that the internal pressure of the container varies and the container is deformed, and the container is used for the rotation of the cap. Tightening can be performed reliably without turning.

FIG. 1 is a plan view of the capping device. (Example 1) FIG. 2 is a longitudinal sectional view of the capping device.

  Conveying means for intermittently conveying the container, holding means for holding the container stopped at the stop position by the conveying means, and a capping head for tightening the cap by covering the mouth of the container held by the holding means And a control means for controlling a holding force for holding the container by the holding means when the cap is tightened. When the cap is tightened on the container, the top surface of the mouth of the container is provided. Until the seal inside the cap comes into contact, the holding means holds the container with a small holding force (first holding force) that hardly applies an external force to the outer surface of the container, and caps the top of the mouth of the container. Since the container is held with a second holding force that is greater than the first holding force after the internal seal portion has come into contact, the container is deformed before the inside of the container is sealed. So as not to cause variations in the internal pressure, after which the container is sealed, so there is no fear of deforming the vessel, to achieve the purpose of preventing rotating together to hold the container with a strong holding force.

  Hereinafter, the present invention will be described with reference to embodiments shown in the drawings. In the capping device according to this embodiment, when the container conveying means (star wheel 4) that intermittently conveys the container 2 and the container 2 that has been intermittently conveyed by the star wheel 4 are stopped at the capping position P. Further, a holding means 6 for holding the container 2 and a capping head 8 (see FIG. 2) which is disposed above the container 2 stopped at the capping position P and winds the cap 12 around the container 2 held by the holding means 6. Reference).

  The container 2 to be capped by the capping apparatus according to this embodiment is a container made of a soft material such as a PET container, and is filled with liquid in a filler (not shown) arranged on the upstream side. Then, it is continuously conveyed by the supply conveyor 10 and delivered to the star wheel 4 that rotates intermittently. The star wheel 4 is formed with a plurality of recesses 4a for receiving the containers 2 at equal intervals in the circumferential direction on the outer periphery, and each container 2 is accommodated one by one in each recess 4a and intermittently one pitch at a time. Rotate. An arcuate outer guide 14 is disposed on the outer peripheral side of the star wheel 4.

  The container 2 is accommodated in each concave portion 4a of the star wheel 4, and the outer peripheral side is guided by the outer guide 14 and rotated and conveyed. A capping position P for tightening the cap 12 around the mouth 2a of the container 2 is provided in the middle of the transport path by the star wheel 4. At this capping position P, a holding means 6 for holding the body 2b of the container 2 and a capping head 8 disposed so as to be movable up and down are provided. The cap 12 is held by the chuck 18 provided at the lower end of the upper capping head 8 in a state where the body 2b of the container 2 is held by the lower holding means 6, and then the capping head 8 is lowered and the cap 12 is put on the mouth 2a of the container 2, and then the cap 12 is wound by rotating. The container 2 that has been capped is rotated and conveyed from the capping position P by the star wheel 4, discharged by the discharge conveyor 20, and sent to the next step. The supply conveyor 10 and the discharge conveyor 20 are provided with guide members 10a, 10b, 20a and 20b for guiding the containers 2 conveyed on both sides. These guide members 10 a, 10 b, 20 a, and 20 b can adjust the interval by the interval adjusting means 22 according to the size of the container 2 to be conveyed.

  Next, the configuration of the capping device will be described with reference to FIG. The star wheel 4 is composed of three circular plates 4A, 4B, and 4C that are upper, middle, and lower. The central and lower two plates 4B and 4C hold the body 2b of the container 2, and one upper plate. The plate 4A holds the neck 2c of the container 2. Therefore, the two plates 4B and 4C at the center and the lower side are provided with a plurality of arc-shaped recesses 4a having an inner diameter substantially equal to the outer diameter of the body 2b of the container 2 at equal intervals in the circumferential direction (this embodiment 8) (see FIG. 1). An elastic body 16 such as rubber is mounted on the inner surface of these arc-shaped recesses 4a. Further, in the upper plate 4A, a small-diameter concave portion 4c having an inner diameter that substantially matches the outer diameter of the neck portion 2c of the container 2 is an arc-shaped concave portion 4a that holds the barrel portion 2b at equal intervals in the circumferential direction. And the center position thereof are made to coincide with each other. The star wheel 4 is rotationally driven by a driving means (not shown). The container 2 conveyed by the supply conveyor 10 has a body portion 2b accommodated in the arc-shaped concave portion 4a and a neck portion 2c accommodated in the small-diameter concave portion 4c. Guided and rotated. At this time, the bottom 2d of the container 2 moves on the arc-shaped plate 24.

  Each of the arcuate recesses 4a of the star wheel 4 receives the container 2 from the supply conveyor 10 and intermittently conveys it, and the intermediate position of the semicircular conveyance path from the delivery to the discharge conveyor 20 is the capping position P Above this capping position P, a capping head 8 for holding and tightening the cap 12 is disposed. Further, the container 2 to be capped is pushed toward the star wheel 4 on the opposite side of the star wheel 4 to the arcuate recess 4a stopped at the capping position P (radially outward of the star wheel 4). A container holding member 26 for holding is disposed.

  The capping head 8 is moved up and down by a lifting means (not shown) and rotated by a rotation driving means. When the capping head 8 is in a raised state, the lower end chuck 18 holds the cap 12, and then the capping head 8. Is lowered, and the cap 12 held by the chuck 18 is put on the mouth 2a of the container 2. Subsequently, the capping head 8 rotates and winds the cap 12 around the screw portion formed on the outer periphery of the mouth portion 2 a of the container 2.

  The container holding member 26 is attached to the front end (swinging end) side of a swinging arm 30 that can rotate in a horizontal plane around a swinging shaft 28 (see FIG. 1), and the front side (star wheel 4 side). An arcuate concave portion 26a having an inner diameter substantially coinciding with the outer diameter of the container 2 is formed. The swing arm 30 is swung by driving means (not shown), the container holding member 26 approaches the star wheel 4 side, and the container is placed between the arcuate recess 4a of the star wheel 4 and the recess 26a of the container holding member 26. 2 is reciprocally oscillated between a position where 2 is held and a retreat position which is separated from the star wheel 4 and does not hinder the rotational movement of the container 2 held in the recess 4 a of the star wheel 4. On the inner surface of the arc-shaped recess 26a of the container holding member 26, an elastic body 36 such as rubber similar to the arc-shaped recess 4a of the star wheel 4 is mounted. Further, a stopper member 32 is attached to the swing arm 30, and when the piston rod 34a of the air cylinder 34 comes into contact with the operation of the air cylinder 34, the swing arm 30 moves forward at a position where the container 2 is held. The position is restricted.

  Further, the apparatus according to the embodiment is provided with a control means (not shown) for controlling the force for holding the container 2 between the container holding member 26 and the star wheel 4 by the operation of the air cylinder 34. Yes. In this embodiment, the container 2 is held in contact with the outer surface of the container 2, but is held with a weak force that hardly applies external pressure to the container 2 (this state is referred to as a first holding force); The second holding force for holding the container 2 can be switched to a force stronger than this. The strength of the container 2 such as a PET container to be capped by the capping apparatus according to this embodiment differs depending on the material, thickness, etc., but the first holding force is that the mouth 2a of the container 2 is opened. Even when the body 2b is gripped in this state, the container 2 is held by a load that does not deform.

  The operation of the capping device according to the above configuration will be described. A container 2 filled with a liquid by a filler (not shown) arranged on the upstream side is continuously conveyed by a supply conveyor 10 and supplied to a star wheel 4 which is a container conveying means of the present invention. The star wheel 4 has eight arc-shaped recesses 4 a formed at equal intervals in the circumferential direction on the outer peripheral side, and the container 2 conveyed by the supply conveyor 10 is placed in each arc-shaped recess 4 a of the star wheel 4. Housed sequentially. The star wheel 4 is rotated intermittently, and the container 2 accommodated in each arcuate recess 4a of the star wheel 4 is guided by the outer guide 14 on the outer peripheral side, and has one pitch in the direction of arrow R in FIG. Rotate to stop and stop.

  When the container 2 conveyed by the star wheel 4 stops at the capping position P, the container holding member 26 that has been retracted to the retracted position is swung to the star wheel 4 side together with the swing arm 30 by a driving means (not shown), The container 2 stopped at the capping position P is held together with the star wheel 4. At this time, when the air cylinder 34 is operated and the piston rod 34a comes out to the forward end, it comes into contact with the stopper member 32 attached to the swing arm 30, and the swing arm 30 moves forward at the holding position of the container 2. Therefore, the container 2 is held by the first holding force, that is, a load that hardly applies external pressure to the container 2.

  In a state where the star wheel 4 and the container holding member 26 (both of which constitute the holding means 6 of claim 1) hold the container 2 with the first holding force, the capping head 8 descends and the capping is performed. The cap 12 held by the chuck 18 provided at the lower end of the head 8 is put on the mouth 2 a of the container 2, and winding is started by the rotation of the capping head 8. At the start of tightening, the member such as the inner provided inside the cap 12 is not fitted or in close contact with the top surface of the mouth 2a of the container 2, so that the tightening torque is small, and the container 2 is held by the holding means 6. Even if the holding force is small, the container 2 does not rotate. After that, when the tightening of the cap 12 proceeds and the container 2 is sealed by starting the fitting of the inner of the cap 12 to the top surface of the mouth portion 2a, the control means operates the cylinder 34 to move the piston rod. The holding force of the container 2 by the holding means 6 is switched by releasing the restriction due to the contact between the stopper member 32 attached to the swing arm 34. The time until the mouth 2a of the container 2 is sealed by starting the fitting of the inner side of the cap 12 to the mouth 2a of the container 2 or the like is temporarily tightened, and the subsequent tightening is regarded as final tightening. During temporary fastening, the holding force of the container 2 by the container holding member 26 is set as the first holding force, and when the final fastening state is reached, the holding force of the container 2 by the container holding member 26 is switched to become the second holding force. In addition, the site | part of the container 2 which the holding means 6 hold | maintains is not restricted to the trunk | drum 2b, Other sites may be sufficient. Further, the holding force of the container 2 by the container holding member 26 may be switched by connecting the piston rod of the air cylinder to the swing arm 30 and switching the operation of the air cylinder. In addition, as the holding means, a plurality of container holding members are provided, and when the final tightening state is reached, the number of places held by the container holding member is increased, or the holding member is switched to a holding member having a strong holding force. The holding force may be switched to become the second holding force.

  As described above, the holding force of the container 2 by the container holding member 26 is switched when the tightening of the cap 12 moves from the temporary tightening stage to the final tightening stage. The winding tightening rotational speed until the final tightening is calculated, and after reaching the predetermined rotational speed, it is assumed that the inner of the cap 12 is fitted and the holding force of the container 2 is switched. Note that the timing of switching the holding force is not limited to the rotation speed of the tightening, but for example, a detection unit that detects the idle rotation of the container 2 is provided, and when the idle rotation is detected by the detection unit, the holding of the container 2 is held. The force may be switched, or the tightening torque may be detected and switched by other methods such as switching when the torque exceeds a predetermined value.

  At the final tightening stage, the tightening torque increases. However, since the holding force of the container 2 by the container holding member 26 and the star wheel 12 is also increased, the container 2 is not rotated. Further, the holding force of the container 2 is increased at the final tightening stage, but since the mouth 2a of the container 2 is already sealed, the internal pressure of the container 2 does not fluctuate, and the container 2 There is no deformation.

2 Container 2a Mouth of container 4 Conveying means (star wheel)
6 Holding means 8 Capping head 12 Cap

Claims (2)

In a capping device comprising a transport means for transporting a container, a holding means for holding the container, and a capping head for tightening the cap around the mouth of the container held by the holding means,
Control means for controlling the holding force with which the holding means holds the container when the cap is tightened with the capping head;
The container is held with the first holding force by the holding means until the top of the mouth of the container comes into contact with the seal inside the cap when the cap is tightened, and the top of the mouth of the container is the seal inside the cap. After the contact, the container is held by the holding means with a second holding force having a load larger than the first holding force.   2. The capping device according to claim 1, wherein the switching of the holding means by the control means from the first holding force to the second holding force is performed by calculating the number of turns of the cap cap screw of the capping head.

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