JP2022011168A - Capping device - Google Patents

Abstract

To restrict an occurrence of 'a stage fall of a screw', in other words, a lower end of a screw of a dropped cap falls on a thread of a stage down from the screw of a container in mounting the cap to a resin container.SOLUTION: When a cap 8 is mounted to a mouth 5C of a container 5 with a capping head 3 while transporting the container 5 at a prescribed operation speed (850bpm), a rotation of a servo motor 12 is started and the cap 8 is rotated in a tightening direction while the capping head 3 is descending before both screws contact (at the time of X1). Then, as a lower end 8A' of the screw 8A of the cap 8 dropped while rotating contacts with and engages with a screw 5D of the container 5 while rotating, an occurrence of 'a stage fall of a screw' can be restricted. Thus, a liquid splash of a filling liquid due to an impact when 'the stage fall of the screw' occurs can be restricted and an inner surface of the cap 8 or the screw 8A, 5D can be prevented from being contaminated by the filling liquid.SELECTED DRAWING: Figure 4

Description

The present invention relates to a capping device, and more particularly to a capping device in which a cap is wound and attached to a resin container.

Conventionally, a capping device in which a cap is wound around a resin container and attached is known (for example, Patent Document 1).
The capping device of Patent Document 1 includes a capping head using a servomotor, and specifically, a cap is attached to the mouth of the container as follows. First, by lowering the chuck of the capping head holding the cap by a required amount and covering the cap with the mouth of the container, the lower end of the screw portion of the cap is brought into contact with the screw portion of the mouth of the container, and the state is reached. Then, by rotating the cap via the chuck with a servo motor, the cap is wound around the mouth of the container and attached.

Japanese Unexamined Patent Publication No. 2002-308380

By the way, in the capping device of Patent Document 1, before the cap is wound around the mouth of the container, the chuck holding the cap is lowered to the position of the mouth of the container, so that the lower end of the screw portion of the cap is placed in the container. It is in contact with the screw part of. At that time, the screw portion of the cap may jump over the screw portion of the container and fall to the screw portion one step below, which may cause "step drop of the screw". When this "screw step-down" phenomenon occurs, there is a problem that the filling liquid in the container is splashed by the impact at that time and adheres to the inner surface of the cap and the screw portion of the cap and the container to be contaminated.
In addition, since the weight of containers and caps has been reduced in recent years, the caps and threaded parts of the containers may not have sufficient strength. There is also a problem that the threaded part of the container is damaged.

In view of the above circumstances, the present invention has a transport mechanism for transporting the container, a capping head having a chuck for holding the cap and attaching the cap to the mouth of the container transported by the transport mechanism, and a chuck of the capping head. A servomotor that rotates the servomotor, an elevating mechanism that raises and lowers the capping head, and a control device that controls the operation of the servomotor and the transport mechanism.
The capping head holding the cap by the chuck is lowered by the elevating mechanism, and the chuck is started to rotate from the stopped state by the servomotor, so that the cap held by the chuck is rotated to the mouth of the container. In the capping device that is wound and attached
Equipped with a speed detection mechanism that detects the transfer speed of the container by the above transfer mechanism.
When the transfer speed of the transfer mechanism detected by the speed detection mechanism is slower than the predetermined operation speed, the control device delays the rotation start evening iming for rotating the servomotor.

According to such a configuration, when the transport mechanism is operated at a predetermined operation speed, the rotation start timing for rotating the servomotor is advanced, so that the cap can be lowered while rotating and covered with the container. Thereby, the impact when the screw portion of the cap and the screw portion of the container mouth mesh with each other can be alleviated. Therefore, it is possible to suppress the occurrence of the above-mentioned "step drop of the screw" and prevent the inner surface of the cap and the screw portion from being contaminated by the filler liquid that has jumped out from the mouth portion of the container.

The plan view which shows one Example of this invention. The vertical sectional view of the main part of FIG. Enlarged view of the main part of FIG. A side view showing the lowering of the cap and the rotation start timing of the cap at each position shown in FIG. The figure which shows the experimental result for comparing the adhesion weight of the filling liquid to the cap after the attachment of the cap by the conventional capping apparatus and the capping apparatus of this invention is completed.

Hereinafter, to explain the present invention with respect to the illustrated embodiment, in FIGS. 1 to 2, 1 is a filling system, and the filling system 1 is a rotary type provided with a plurality of filling valves (not shown) at equal pitches on the outer peripheral portion. It is provided with a filler 2 and a rotary capping device 4 having a plurality of capping heads 3 at equal pitches on the outer peripheral portion.
While the filler 2 and the capping device 4 are rotating in the direction of the arrow, an empty container 5 is supplied below each filling valve of the filler 2 by a supply wheel (not shown), and each container 5 is provided with the filler 2. It is gripped by a gripper (not shown) and filled with a predetermined amount of filling liquid by a filling valve. Then, each container 5 filled with the filling liquid by the filling valve of the filler 2 is released from the gripped state by the gripper of the filler 2 and is delivered from the filler 2 to the capping device 4 via the intermediate wheel 6. It has become.

The capping device 4 includes a capping head 3 for holding the cap 8 by a chuck 7 at equidistant positions on the outer peripheral portion, and an openable gripper 4A for gripping the neck portion 5A of the container 5 below each capping head 3. ing.
The container 5 delivered from the intermediate wheel 6 is filled with a filling liquid 9 inside, and the liquid level 9A is located slightly below the brim portion 5B of the neck portion 5A. The container 5 is gripped on both sides of the neck portion 5A by the gripper 4A, and is supported by the brim portion 5B formed on the neck portion 5A so as to be conveyed at a predetermined height (see FIG. 2).
Further, a screw portion 5D is formed on the outer peripheral portion of the mouth portion 5C of the container 5, while a screw portion 8A screwed to the screw portion 5D of the container 5 is formed on the inner peripheral portion of the cap 8. (See FIGS. 2 and 4).
Further, an inner ring 5E is formed between the brim portion 5B and the screw portion 5D in the container 5, while a disconnection ring 8B is provided at the lower end portion of the cap 8 (FIGS. 2 and 2). 4).

As the capping device 4 is rotated in the direction of the arrow, the capping head 3 is lowered from the ascending end to the descending end by the elevating mechanism 11, and the chuck 7 is predetermined by the servomotor 12 provided for each capping head 3. By being rotated in the winding direction at the timing, the cap 8 held by the chuck 7 is lowered, and the cap 8 is covered with the mouth portion 5C of the container 5 and then wound and attached.
As will be described in detail later, in this embodiment, when the capping device 4 is operated at a predetermined operating speed or higher, the rotation of the servomotor 12 is started while the capping head 3 is being lowered by the elevating mechanism 11. It is configured to rotate the cap 8 so that the occurrence of the above-mentioned "screw step drop" is suppressed, and the lower end 8A'of the screw portion 8A of the cap 8 is the screw portion 5D of the container 5. It is designed to mesh smoothly with the screw.
The container 5 to which the cap 8 has been attached by each capping head 3 of the capping device 4 is then released from the gripped state of the neck portion 5A by the gripper 4A and is gripped by the discharge wheel 13 from the capping device 4 onto the discharge conveyor 14. After that, it is conveyed to a processing device (not shown) on the downstream side by the discharge conveyor 14 (see FIG. 1).

The capping device 4 includes a rotating body 16 that is rotated clockwise to convey the container 5, a plurality of capping heads 3 arranged at equal pitches in the circumferential direction of the outer peripheral portion of the rotating body 16, and a rotating body 16. An elevating mechanism 11 that raises and lowers the capping head 3 in a predetermined region in the rotation direction, a gripper 4A that is arranged below the capping head 3 and grips the neck portion 5A of the container 5, a drive source of the rotating body 16, and each servomotor. A control device 17 for controlling the operation of the 12 is provided.
A transport mechanism for transporting the container 5 is configured by the rotating body 16 and a plurality of grippers 4A provided therein. As described above, the container 5 is such that the neck portion 5A is gripped by the gripper 4A and the brim portion 5B is supported, and in that state, the container 5 is conveyed at a predetermined speed as the rotating body 16 rotates. It is supposed to be done.
The operation of a motor (not shown) that is a drive source of the rotating body 16 is controlled by the control device 17. Further, a speed detection mechanism 18 (encoder) for detecting the operating speed of the rotating body 16 is attached to the motor serving as a driving source of the rotating body 16, and the rotating body 16 detected by the speed detecting mechanism 18 is conveyed. The speed, that is, the operating speed of the capping device 4, is input to the control device 17.
In this embodiment, when the control device 17 rotates the rotating body 16 by a motor (not shown), the operating speed at which the caps 8 are attached to a total of 850 containers 5 per minute by the capping head 3 conveyed by the rotating body 16. Is set as "predetermined operating speed (850 bpm)".
Further, by controlling the operation of the motor that is the drive source of the rotating body 16, the control device 17 controls the operation of the rotating body 16 at an operating speed (for example, 750 to 650 bpm) slower than the predetermined operating speed (850 bpm), if necessary. Is designed to rotate.
The transport speed (operating speed) when the rotating body 16 is rotated is detected by the speed detection mechanism 18 and input to the control device 17, and the control device 17 is capped by the detection signal input from the speed detection mechanism 18. The operating speed of the device 4 is recognized.

As shown in FIG. 2, the capping head 3 has a cylindrical outer cylinder 21 provided on the outer peripheral portion of the rotating body 16 so as to be able to move up and down, and the capping head 3 is provided rotatably and vertically on the inside of the outer cylinder 21. A spindle 22, a chuck 7 attached to the lower end of the spindle 22 to detachably hold the cap 8, and an inner cylinder 23 connected to the upper end of the spindle 22 and having a spline groove formed in the inner peripheral portion. A spline shaft 24 spline-fitted into the spline groove of the inner cylinder 23, and a servomotor 12 connected to the upper end of the spline shaft 24 are provided.
The inner cylinder 23, the spindle 22, and the chuck 7 can be raised and lowered with respect to the outer cylinder 21, and they are supported by the step portion 21A of the outer cylinder 21. A spring 26 is mounted between the brim portion 22A on the spindle 22 side and the step portion 21A in the outer cylinder 21 facing the flange portion 22A. The elastic force of the spring 26 always urges the spindle 22 and the chuck 7 provided at the lower end thereof downward with respect to the outer cylinder 21.
A cam follower 27 is attached to the inside of the upper portion of the outer cylinder 21, and the cam follower 27 is rotatably engaged with the cam groove 28A of the annular cam 28 arranged along the outer peripheral portion of the rotating body 16. There is. The annular cam 28 and the cam follower 27 constitute an elevating mechanism 11 for elevating and lowering the capping head 3.
As the rotating body 16 is rotated in the direction of the arrow in FIG. 1, the chuck 7 of the capping head 3 has an ascending end and a descending end according to the height of the cam groove 28A of the elevating mechanism 11 in the required region of the rotating section. The chuck 7 is rotated by the servomotor 12 in the winding direction with a predetermined closing torque at a predetermined timing.
As shown in FIGS. 3 and 4, at the delivery position A where the container 5 is delivered from the intermediate wheel 6 to the capping device 4 and the position on the adjacent downstream side thereof, the annular cam 28 of the elevating mechanism 11 is the rising end. After that, the height of the annular cam 28 gradually decreases on the adjacent downstream side in the rotation direction of the rotating body 16 and then becomes the bottom dead center which is the descending end B (see FIG. 4). The intermediate region connecting the ascending end and the descending end of the annular cam 28 is the descending region C in which the capping head 3 is lowered by the annular cam 28. In the region on the adjacent upstream side of the delivery position A (not shown), the annular cam 28 is configured to return from the descending end to the ascending end.

The operation of the servomotor 12 that rotates the chuck 7 holding the cap 8 is controlled by the control device 17. An encoder 31 that outputs a pulse signal is connected to the rotating portion of the servomotor 12, and an ammeter 32 that detects the output current of the servomotor 12 is connected. When the servomotor 12 is rotationally driven, the pulse signal output from the encoder 31 is input to the control device 17, and the current output from the servomotor 12 is detected by the current meter 32 and input to the control device 17. It has become so.
The control device 17 can recognize the rotation angle and the rotation speed of the servomotor 12 based on the pulse signal detected by the encoder 31. Further, the control device 17 detects the closing torque acting on the chuck 7 from the current value detected by the ammeter 32 after the servomotor 12 is rotationally driven, and records it in time series. There is.

Therefore, in this embodiment, the servomotor 12 is operated in a case where the rotating body 16 of the capping device 4 is operated at a predetermined operating speed (850 bpm) or higher and a case where the rotating body 16 is operated at a speed lower than the predetermined operating speed. It is characterized by being configured to change the rotation start timing.
Specifically, the control device 17 controls the rotation start timing of the servomotor 12 as follows when the capping head 3 and the chuck 7 are lowered by the elevating mechanism 11.
When the rotating body 16 is operated at a predetermined operating speed (850 bpm) or higher, the control device 17 determines that the rotating body 16 is being operated at a predetermined operating speed based on the input signal from the speed detection mechanism 18. Upon recognition, when the chuck 7 (cap 8) is lowered to the time point X1 where the capping head 3 is at the intermediate position of the lowering region C by the annular cam 28 of the elevating mechanism 11, the rotation of the servomotor 12 is started at that time (FIG. FIG. 3. See Fig. 4)).
Therefore, since the cap 8 is rotated in the winding direction from that time X1 until the capping head 3 is lowered to the lowering end B by the elevating mechanism 11, the lower end portion 8A ′ of the screw portion 8A of the rotating cap 8 is rotated. Smoothly contacts the threaded portion 5D of the container 5 from above, and both threaded portions 8A and 5D mesh with each other.
In a state where the cap 8 is pressed downward by the spring 26 after the two screw portions 8A and 5A are smoothly meshed with each other, the cap 8 is continuously rotated by the servomotor 12 in the winding direction, whereby the cap is capped. The screw portion 8A of 8 is wound around the screw portion 5D of the container 5 to complete the attachment of the cap 8.
In other words, in this embodiment, when the rotating body 16 is operated at a predetermined operating speed (850 bpm) or higher, the time point before the lower end portion 8A'of the threaded portion 8A of the cap 8 comes into contact with the threaded portion 5D of the container 5. At X1, the servomotor 12 is started to rotate from a stopped state.
As a result, the lower end 8A'of the screw portion 8A of the cap 8 smoothly meshes with the screw portion 5D of the container 5, so that the above-mentioned "step drop of the screw" can be effectively suppressed. There is.
On the other hand, in a state where the rotating body 16 is being operated at the predetermined operating speed (850 bpm), some trouble may occur in a processing device (not shown) arranged on the downstream side of the discharge conveyor 14. In that case, the operating speed of the rotating body 16 is operated at a speed slower than the predetermined operating speed (for example, 600 bpm, 750 bpm). Then, at that time, the control device 17 recognizes that the operating speed has become slower than the predetermined operating speed by the speed detecting mechanism 18.
Then, the control device 17 keeps the servomotor 12 stopped without rotating until the capping head 3 is lowered to the lowering end B by the annular cam 28 of the elevating mechanism 11, and the capping head 3 is stopped by the elevating mechanism 11. The rotation of the servomotor 12 is started at the time point X2 when the servomotor 12 descends to the descending end B. That is, when the cap 8 is lowered to the lowering end B, the control device 17 rotates the servomotor 12 at the time X2 when the lower end portion 8A'of the threaded portion 8A of the cap 8 comes into contact with the threaded portion 5D of the container 5. The cap 8 is started and rotated in the winding direction to be attached to the mouth portion 5C of the container 5 (see FIGS. 3 and 4).

As described above, in the present embodiment, when the rotating body 16 of the capping device 4 is operated at a predetermined operating speed (850 bpm), it is in the middle of the lowering region C when the capping head 3 is lowered by the elevating mechanism 11. At the time point X1 located at, the rotation of the servomotor 12 is started. As a result, when the chuck 7 is lowered to the lowering end B, the cap 8 is also rotated in the winding direction via the chuck 7, so that the lower end portion 8A'of the screw portion 8A of the cap 8 is the container 5. The impact when contacting the threaded portion 5D from above is alleviated, and both threaded portions 8A and 5D are smoothly meshed with each other.
As a result, it is possible to effectively suppress the occurrence of "step drop of the screw" when the cap 8 is attached to the container 5. Therefore, due to the impact when the "step drop of the screw" occurs, the filling liquid 9 in the container 5 splashes and adheres to the inner surface of the cap 8 and the screw portions 8A and 5D, and these parts are contaminated. Can be prevented.
Further, when the rotating body 16 is being operated at a predetermined operating speed (850 bpm) and the operating speed of the rotating body 16 is switched to an operating speed (650 bpm or 750 bpm) slower than the predetermined operating speed, it depends on the operating speed. The timing at which the rotation of the servomotor 12 is started can be changed by the control device 17.
Therefore, even when the rotating body 16 is switched from a predetermined operating speed to a slower operating speed when a trouble occurs in the processing device on the downstream side, the rotation of the servomotor 12 starts at an appropriate timing accordingly. The timing can be controlled.
FIG. 5 shows the experimental results comparing the contamination state of the cap 8 after the attachment of the cap 8 is completed between the case where the conventional capping device is used and the case where the capping device 4 of the present embodiment (invention of the present application) is used. It is a thing. In this experiment, instead of transporting the container 5, the experimental results after the completion of the attachment of the cap 8 according to the conventional technique and the present embodiment are compared with the conventional technique in the state where the container 5 is stopped.
As can be understood from the data of FIG. 5, the cap 8 is lowered to the lowering end so that the lower end of the threaded portion of the cap 8 is brought into contact with the threaded portion of the container 8 and then the cap 8 is rotated. In the capping device of No. 1, the amount of the filling liquid (product liquid) adhering to the cap 8 or the like is 51 mg at the maximum.
On the other hand, in the case of the present embodiment in which the cap 8 is rotated and attached to the container 5 at the time of descending in the descending region C, the adhered amount of the filling liquid (product liquid) is 1 mg. As is clear from the experimental results shown in FIG. 5, according to the capping device 4 of the present embodiment as compared with the conventional case, the “screw step-down” phenomenon is suppressed and the screw step-down occurs. It can be presumed that the cap 8 and the like can be effectively suppressed from being contaminated by the liquid splash caused by the impact of the above.
In the above embodiment, the predetermined operating speed is 850 bpm, but the predetermined operating speed is not limited to 850 bpm, and may be 900 bpm or more and 1000 bpm. Also in this case, the cap 8 is rotated and attached to the container 5 at the time of descending in the descending region C.

3 ‥ Capping head 4 ‥ Capping device 5 ‥ Container 5C ‥ Mouth part 5D ‥ Screw part 7 ‥ Chuck 8 ‥ Cap 8A ‥ Screw part 8A ‥ ‥ Screw part lower end part 9 ‥ Filling liquid 11 ‥ Elevating mechanism 12 ‥ Servo motor 16 ‥ Control device 18 ‥ Speed detection mechanism

Claims (3)

A transport mechanism for transporting a container, a capping head having a chuck for holding a cap and attaching a cap to the mouth of the container transported by the transport mechanism, a servomotor for rotating the chuck of the capping head, and a capping head. It is equipped with a lifting mechanism for raising and lowering the servomotor and a control device for controlling the operation of the servomotor and the transport mechanism.
The capping head holding the cap by the chuck is lowered by the elevating mechanism, and the chuck is started to rotate from the stopped state by the servomotor, so that the cap held by the chuck is rotated to the mouth of the container. In the capping device that is wound and attached
Equipped with a speed detection mechanism that detects the transfer speed of the container by the above transfer mechanism.
The control device is a capping device characterized in that when the transfer speed of the transfer mechanism detected by the speed detection mechanism is slower than a predetermined operation speed, the rotation start evening iming for rotating the servomotor is delayed. When the transport mechanism transports the container at a predetermined operating speed, the chuck of the capping head is being lowered by the elevating mechanism, and the screw portion of the cap held by the chuck contacts the screw portion of the container. The capping device according to claim 1, wherein the control device starts the rotation of the servomotor at the time before the operation. When the transport mechanism transports the container at an operating speed slower than the predetermined operating speed, the chuck of the capping head is lowered by the elevating mechanism, and the threaded portion of the cap held by the chuck is the threaded portion of the container. The capping device according to claim 2, wherein the control device starts the rotation of the servomotor after the contact with the servomotor.

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