JP7528698B2 - cap - Google Patents

Description

The present invention relates to a cap that is screwed onto the mouth of a container to close the mouth of the container.

In recent years, for products that contain shampoo, conditioner, liquid detergent, etc. in containers, there has been an increase in products that use pouch containers made of flexible sheets for refilling, from the standpoint of environmental protection and reducing the volume of containers when they are disposed of.

In particular, large-capacity pouch containers are fitted with a synthetic resin spout and a cap (screw-type cap) that is screwed onto the spout to seal it, and as they are equipped with a cap, they can be refilled into a mating container multiple times.

Pouch containers are also used as containers for storing beverage products such as jelly drinks, and are similarly fitted with a spout (mouthpiece) and a cap that screws onto the spout to seal it.

The opening diameter of the spouts attached to pouch containers that contain refills or beverage products is relatively small, and the caps are similarly small. For this reason, various ideas have been proposed for the cap to improve the grip of the fingertips when opening and closing the cap. One idea, which is not limited to small caps, is to arrange a knurl consisting of multiple ridges on the outer periphery of the cap peripheral wall, making the entire cap peripheral wall a knurled portion.

Furthermore, as another innovation to improve the grip of the fingers when opening and closing the cap, Patent Document 1 lists making the shape of the plastic bottle cap polygonal when viewed from above, demonstrating the convenience and ease of being able to open the cap with little force without the fingers slipping. Patent Document 1 also shows the convenience of being able to provide Braille on the flat surface of the polygonal part.

In manufacturing lines for PET bottle products, the equipment on the line has been designed with technology to properly grip the caps. For example, one technology for mechanically gripping caps is the cap grip of a cap tightening device that seals the mouths (pouring outlets) of PET bottles. As shown in Patent Document 2, the cap grip wraps the entire cap from the feeder except for the bottom side, and transports it to the top of the mouths of the PET bottles that are fed in succession.

The cap grip has three or four locking claws that grip the entire circumference of the cap, and while rotating it caps it. After a certain number of rotations the cap is released and the entire cap grip moves upwards and away from the plastic bottle.

JP 2009-007065 A Japanese Utility Model Application Publication No. 06-018296

The caps are synthetic resin molded products that are molded separately from the pouch container body, the spout, and the PET bottle body. The caps themselves undergo various inspections before being shipped as products with uniform quality. These caps are continuously supplied to the filling lines for pouch containers and PET bottle containers, where they are screwed onto the spout of the pouch container or the mouth of the PET bottle container.

Meanwhile, within the manufacturing industry, at plastic molding sites, factors such as a decline in the labor force and an aging workforce are placing a heavy burden on workers engaged in the plastic molding business, and the issue of business succession is also coming to the fore.

Cap manufacturing is also included in the plastic molding business mentioned above. During the cap molding process, inspectors periodically sample products and perform visual inspections, weight measurements, dimensional measurements, and functionality tests, and also carry out various inspection procedures before shipment.

In order to check quality while reducing the burden on workers who perform these various measurement, inspection and quality control tasks, there has been an increase in the introduction of devices that monitor molding process data and visual inspection machines, and the mechanization of inspection is progressing.

In line inspection machines, the caps are transported on a conveyor and the inspection process is carried out, but if you want to carry out all inspections, including dimensional inspection, weight inspection, and functionality inspection, it will be necessary to pick up and transport each molded product individually under each inspection device. To achieve this, it is expected that multi-axis robots and the like will be used.

When inspecting parts on manufacturing lines that mold parts for automobiles, home appliances, and office equipment, the parts being inspected have parts that can be picked up, so it is thought to be relatively easy to grab the parts with a gripper such as a multi-axis robot.

However, when it comes to small molded products such as the caps that are attached to the spouts of the above-mentioned pouch containers, emphasis is placed on usability, and they are not designed to be easily grasped by automatic inspection robots. This point is explained below.

Specifically, when using a multi-axis robot to transport caps one by one to a position below an inspection machine or to an inspection location, one method is to provide chuck hands for clamping the caps to an actuator placed in the working section of the multi-axis robot, and to move the caps by pinching them from both sides while they are placed upright.

As shown in Figures 5(a) and (b), the existing cap a has a shape in which multiple knurls c, which are vertical ridges, are provided on the outer peripheral surface of the cap peripheral wall b, and the entire cap peripheral wall is made into a knurled portion d, allowing the cap to be opened and closed without the fingers slipping.

The cap peripheral wall b is inclined toward the cap central axis in the upward height direction, and the knurled portion d, including the knurled portion c, is tapered so that the diameter of the knurled portion d decreases in the upward height direction.

However, with the existing cap a, when the knurled portion d is clamped by the chuck hand e from both sides, it is clamped in a state where it is in contact with the knurled portion c. Then, as shown by the arrow A in FIG. 7, the lower edge g of the gripping surface f of the chuck hand e comes into contact with part of the ridgeline h of the knurled portion c, and the chuck hand e and the knurled portion c only make localized point contact. Also, as shown by the arrow B in FIG. 7, a gap j is created between the knurled portion c and the upper edge i of the gripping surface f of the chuck hand e. This makes the gripping state of the chuck hand e unstable.

In addition, because the contact area is small, chuck pressure is required to prevent cap a from dropping when gripped, and there is a problem in that gripping it too tightly can cause the cap to deform.

In view of the above, the present invention aims to enable a chuck hand attached to a working unit such as a multi-axis robot to securely grip small caps, and to reduce the labor involved in product inspection by mechanizing the transportation of caps during inspection.

The present invention has been made in consideration of the above-mentioned problems, and solves the above-mentioned problems by providing a cap for sealing the mouth of a container, the cap having, in a part in the cap height direction, a polygonal prism portion in which the outer periphery of the cap peripheral wall is polygonal, the cap peripheral wall being divided in the cap height direction into the polygonal prism portion and a knurled portion formed by arranging a plurality of knurls around the outer periphery of the cap peripheral wall, the polygonal prism portion being located above the knurled portion and on the cap top side, and the height dimension of the polygonal prism portion and the knurled portion being in the range of 1:2 to 1:3 .

In the present invention, it is also preferable that each of the side surfaces of the polygonal prism is an elevational surface and is arranged parallel to the central axis of the cap, and that side surfaces positioned opposite each other in the radial direction of the cap are arranged parallel to each other.

In the present invention, it is preferable that the polygonal prism has a hexagonal or octagonal shape in a plan view.

In the present invention, it is also preferable that the distance between the side surfaces arranged in parallel to face each other in the radial direction of the cap is equal to or smaller than the outer diameter of the peripheral wall of the cap at the knurled portion.

In the present invention, the cap can be held by a holding means that performs a holding operation,
It is preferable that each of the side surfaces of the polygonal prism portion is a flat surface corresponding to a gripping surface of the gripping means for gripping and transporting the cap.

According to the present invention, since the cap is provided with a polygonal prism portion, when the cap is grasped and transported using a multi-axis robot having a gripping means at the end of its arm, the gripping surface of the gripping means can be placed against the side of the polygonal prism portion, thereby ensuring a wide contact area between the gripping means and the peripheral wall of the cap.

As a result, mechanical transport, in which the cap is grasped and transported using a gripping means provided on the multi-axis robot or the like, can be carried out with much greater stability than conventional transport, in which the knurled portion of the cap is grasped and transported.

In addition, by setting a polygonal prism as the part that is gripped by the gripping means and having the gripping surface of the gripping means come into contact with the side surface of the polygonal prism, deformation and scratches that tend to occur when the gripping means grips the cap are not generated. This makes it possible to eliminate defects that occur after the molding process of the synthetic resin cap.

The cap peripheral wall not only has a polygonal columnar section, but also has a knurled section that prevents a person's fingers from slipping when opening and closing the cap, so the cap can be rotated reliably when opening and closing.

In addition, compared to conventional caps, the shape of the cap does not have any knurling on part of the peripheral wall, which reduces the amount of resin used to mold the cap and makes it lighter. This reduces the manufacturing cost of the cap.

In addition, the cap has been designed to be suitable for use with automated inspection equipment using multi-axis robots, helping to reduce the number of workers required in the plastic molding process.

In addition , since the polygonal prism portion is located on the top side of the cap, if the cap is placed upright on a table or the like before inspection (with the top of the cap facing up and the opening on the bottom side of the cap facing down), the caps can be lined up with the polygonal prism portion facing up.

And by positioning the polygonal column portion on the top side of the cap, a large space is secured for moving the gripping means toward the cap, which has the effect of increasing the degree of freedom in setting the movement of the gripping means.

Furthermore, because the top of the cap is a closed top wall, it has greater strength in the radial direction of the cap than the lower part of the cap, which has an open part through which the mouth of a container can be inserted. Therefore, even if a polygonal column is disposed on the top side of the cap, it is easy to ensure the strength to resist the grip of the gripping means attached to the working arm of the multi-axis robot, and there is an advantage that no deformation occurs even when the polygonal column is gripped by the gripping means.

According to the present invention, each of the side surfaces of the polygonal prism is parallel to the central axis of the cap, and when the cap is placed upright, the side surfaces stand upright. In each pair of side surfaces facing each other across the central axis of the cap, the side surfaces are arranged parallel to each other.

In this way, the sides of the polygonal column are flat and stand upright, and the opposing sides are parallel, so various types of gripping means can be used to hold the cap, from simple, inexpensive types with parallel opening and closing mechanisms to multi-fingered hand types.

In addition, according to the present invention, since the planar shape of the polygonal prism portion is hexagonal or octagonal, there are six or eight directions in which the gripping means can grip the cap, which has the advantage that there are more directions in which the gripping means can be brought close to the polygonal prism portion.

According to the present invention, the distance between the parallel side surfaces of the polygonal column is set to be equal to or less than the outer diameter of the knurled portion of the peripheral wall of the cap, thereby making it possible to reduce the amount of resin required for molding the cap by eliminating the knurling from the peripheral wall of the cap while ensuring a wall thickness that can be properly gripped by the gripping means, and also to reduce the weight of the cap.

Furthermore, according to the present invention, since the side surfaces of the polygonal prism portion are flat, it is possible to reliably grip the cap without increasing the gripping pressure of the gripping means.

This shows an example of a cap according to the present invention in which the polygonal column portion is octagonal, where (a) is an explanatory diagram showing the state as seen from the top side of the cap, and (b) is an explanatory diagram showing the state as seen from the side. 13 shows an example in which the polygonal column portion is hexagonal, where (a) is an explanatory diagram showing the state as seen from the top side of the cap, and (b) is an explanatory diagram showing the state as seen from the side. FIG. These figures show the state in which a cap having an octagonal polygonal column portion is gripped by a gripping means, where (a) is an explanatory diagram showing the state as viewed from above, (b) is an explanatory diagram showing the state as viewed from the side, and (c) is an explanatory diagram showing the state as viewed from another side. These figures show the state in which a gripping means grips a cap whose polygonal column portion is hexagonal, where (a) is an explanatory diagram showing the state as viewed from above, (b) is an explanatory diagram showing the state as viewed from the side, and (c) is an explanatory diagram showing the state as viewed from another side. 1A and 1B are explanatory diagrams showing a conventional cap as viewed from the top side of the cap, and FIG. 1B is an explanatory diagram showing the cap as viewed from the side. 1A and 1B are explanatory diagrams showing a state in which a conventional cap is gripped by a gripping means, in which (a) is an explanatory diagram showing the state as seen from above, and (b) is an explanatory diagram showing the state as seen from the side. 13A and 13B are explanatory views showing a state in which a conventional cap is gripped by a gripping means, in which FIG. 13A is an explanatory view showing the state as seen from another side, and FIG. 13B is an explanatory view showing an enlarged view of portions A and B. FIG.

The present invention will now be described in detail based on the embodiment shown in Figures 1 to 4. In the figures, reference numeral 1 denotes a synthetic resin cap for attaching to a pouring outlet or a bottle mouth to seal it. The cap 1 has an annular band 3 that engages with a step provided on the pouring outlet or the bottle mouth when the cap body 2 is rotated in the opening direction after the cap body 2 is capped on the pouring outlet or the bottle mouth (not shown).

The cap 1 is designed so that the band 3 remains on the spout side and the bottle mouth side as the cap 1 continues to rotate in the opening direction. When the cap 1 is molded, the band 3 is connected to the lower part of the cap body 2 via a breakable bridge 4, as shown in Figure 1(b).

(Cap peripheral wall)
The cap body 2 has a cap peripheral wall 6 that continues downward from the periphery of the cap top 5, and the inner circumference of the cap peripheral wall 6 is provided with an internal thread (not shown) that corresponds to the external thread of the pouring outlet or bottle mouth.

(Knurled part)
1(b), the cap peripheral wall 6 is divided into a polygonal columnar portion 7 located on the cap top portion 5 side in the cap height direction, and a knurled portion 8. The knurled portion 8 is formed by positioning a plurality of knurls 9, which are convex outward, at intervals around the outer circumferential surface of the cap peripheral wall 6, in the vertical direction from a height position that is the boundary with the polygonal columnar portion 7 to a height position that is the lower end of the cap peripheral wall 6.

The cap peripheral wall 6 at this knurled portion 8 is inclined so as to approach the cap central axis as it moves upward in the cap height direction. The knurling 9 also inclines toward the cap central axis along the inclination of the outer surface of the cap peripheral wall 6, and the entire knurled portion 8 is provided in a tapered shape that gradually reduces in diameter as it moves upward.

(Polygonal column part)
The polygonal column portion 7 is formed by arranging a plurality of flat surfaces, each of which is an upright surface, in the circumferential direction of the cap peripheral wall 6 to form a polygonal outer peripheral shape of the cap peripheral wall 6, and each of the flat surfaces is made into a side surface 10 that stands up parallel to the central axis of the cap, forming a columnar shape. The polygonal column portion 7 of the cap 1 shown in Fig. 1(a) is an example in which the shape in a plan view is an octagon.

The octagonal shape of the polygonal column section 7 in plan view is formed to have a regular octagon, so that the side surfaces 10 that face each other in the cap radial direction are arranged parallel to each other. The center of the polygonal column section 7 and the central axis of the cap are aligned, and the parallel pair of side surfaces 10 face each other parallel to each other with the central axis of the cap between them.

Each side surface 10 is a flat surface that corresponds to the gripping surface of the gripping means described below that grips and transports the cap 1. And because the polygonal columnar portion 7 is gripped by a gripping means attached to the tip of a working arm of a multi-axis robot or the like, unlike gripping with a human fingertip, each side surface 10, which is a flat surface, does not need to be finished to a surface with high smoothness. For example, as long as 60% or more of the surface area of each side surface 10 is formed as a flat surface, it is considered to be a flat surface that properly contacts the gripping surface of the gripping means without slipping, even if there are some irregularities.

In FIG. 1(a), reference numeral 11 denotes the distance between the side surfaces 10 arranged in a parallel positional relationship, and reference numeral 12 denotes the outer diameter of the cap peripheral wall 6 at the knurled portion 8. In the illustrated example of the cap 1, the maximum distance 11 between the side surfaces 10 is set to be equal to or smaller than the outer diameter 12 of the cap peripheral wall 6 at the knurled portion 9.

In particular, the knurled portion 8 has a tapered shape tapering upward as described above, and the polygonal columnar portion 7 is located at the top of the knurled portion 8, which has a tapered shape. The maximum opposing distance 11 of the side surfaces 10 is set to be equal to or less than the minimum outer diameter 12 of the cap peripheral wall 6 at the knurled portion 8. Furthermore, in the polygon (octagon) shown in the planar shape of the polygonal columnar portion 7, the maximum length 13 of the diagonal line is also set to be equal to or less than the minimum outer diameter 12.

In this way, by making the maximum opposing distance 11 equal to or less than the outer diameter 12 of the cap peripheral wall 6 at the knurled portion 8, and by making the maximum diagonal length 13 of the polygonal column portion 7 equal to or less than the outer diameter 12, the gripping means for gripping the polygonal column portion 7, which will be described later, can be made compact.

In addition, bringing the opposing distance 11 close to the outer diameter dimension 12 and making the maximum diagonal length 13 of the regular polygon equal to or close to the outer diameter dimension 12 is advantageous in terms of ensuring the thickness of the cap peripheral wall 6 at the polygonal column portion 7.

(Plane view shape - hexagon)
In FIG. 1, an example is shown in which the polygonal prism portion 7 has a regular octagonal shape in a plan view, but the shape of the polygonal prism portion 7 is not limited to an octagonal shape in a plan view. The viewed shape may be a regular hexagon.

Figure 2(a) shows the cap 1 as viewed from the cap top 5 side, and Figure 2(b) shows the cap as viewed from the side. The example shown in Figure 2 differs from the example shown in Figure 1 only in that the planar shape of the polygonal columnar portion 7 is a regular hexagon, and the rest is the same.

In addition, in a cap 1 in which the polygonal column portion 7 has a regular hexagonal shape in plan view, it may be difficult to ensure the thickness of the cap peripheral wall 5 at the polygonal column portion 7. In such a case, the polygonal column portion 7 may be made into a regular octagonal shape.

(Gripping Means)
3 shows a state in which the cap 1, whose polygonal columnar portion 7 is octagonal (in plan view), is gripped by the gripping means 14. The gripping means 14 is attached to the tip of a working arm of a multi-axis robot. For example, the multi-axis robot is configured to transport each cap 1 that has completed the manufacturing process to an inspection area, and the gripping means 14 grips and transports the cap 1 to the inspection area.

As shown in FIG. 3, the gripping means 14 is composed of an actuator 15 and a chuck hand 16 that opens and closes in parallel. When the gripping means 14 grips the cap 1, the distance between the gripping surfaces of the chuck hand 16 is widened so that it is larger than the distance 11 between the opposing side faces 10 of the octagonal polygonal prism portion 7, and in this state, the gripping means 14 moves so that the polygonal prism portion 7 of the cap 1 is positioned between the widened chuck hands 16 (between the gripping surfaces).

At this time, the movement of the working arm (not shown) is controlled so that the gripping surface 17 of the chuck hand 16 and the side surface 10 of the polygonal column portion 7 are parallel to each other. Also, in FIG. 3(a), the chuck hand 16, which is in a standby state with the gap wider than the facing distance 11, is shown by a dashed line.

Then, the chuck hand 16 closes, gripping the polygonal column portion 7 with the gripping surface 17 in surface contact with the side surface 10. Then, with the chuck hand 16 closed and the gripping means 14 gripping the polygonal column portion 7, the cap 1 is transported toward the inspection equipment side or the like. To open the cap 1, the cap 1 is placed upright in a predetermined position by a movement preset in the multi-axis robot, after which the chuck hand 16 opens and the gripping means 14 moves to a standby position.

Figure 4 shows the state in which a cap 1 with a hexagonal polygonal prism portion 7 (shape in plan view) is gripped by the gripping means 14. The difference from the above-mentioned case in which a cap 1 with an octagonal polygonal prism portion 7 is transported is that the object to be clamped by the chuck hand 16 is the hexagonal polygonal prism portion 7, but otherwise it is the same.

The material of the chuck hand 16 of the gripping means 14 that grips the synthetic resin cap 1 is not limited, and metal materials such as stainless steel or resin materials can be used.

In the height direction of the cap 1, the height dimension ratio between the polygonal columnar portion 7 and the knurled portion 8 is preferably about 1:2 to 1:3, provided that the height dimension of the gripping surface 17 of the chuck hand 16 is ensured on each side surface 10 of the polygonal columnar portion 7.

In addition, with regard to the shape (shape in plan view) of the polygonal column portion 7, the above-mentioned hexagon to octagon is desirable in order to ensure a sufficient contact area between the side surface 10 and the gripping surface 17 of the chuck hand 16.

Reference Signs List 1: Cap 2: Cap body 3: Band 5: Cap top 6: Cap peripheral wall 7: Polygonal column portion 8: Knurled portion 9: Knurled 10: Side surface 14: Gripping means 15: Actuator 16: Chuck hand 17: Gripping surface

Claims (5)

A cap for sealing a mouth of a container, the cap having a polygonal columnar portion in a part in a height direction of the cap, the outer peripheral shape of the cap peripheral wall being polygonal,
the cap peripheral wall is divided in a cap height direction into the polygonal column portion and a knurled portion formed by arranging a plurality of knurls around an outer circumferential surface of the cap peripheral wall, the polygonal column portion being located on an upper portion of the knurled portion and on the cap top side,
A cap characterized in that a height dimension ratio between the polygonal column portion and the knurled portion is in a range of 1:2 to 1:3 . 2. The cap according to claim 1 , wherein each of the side surfaces of the polygonal prism portion is an elevational surface and is arranged parallel to a central axis of the cap, and the side surfaces positioned opposite each other in a radial direction of the cap are arranged parallel to each other. The cap according to claim 1 or 2 , wherein a planar shape of the polygonal columnar portion is a hexagon or an octagon. 3. The cap according to claim 2 , wherein the distance between the side surfaces arranged in parallel to face each other in the radial direction of the cap is equal to or smaller than an outer diameter of the peripheral wall of the cap at the knurled portion. The cap is capable of being gripped by a gripping means having a gripping action,
3. The cap according to claim 2 , wherein each of the side surfaces of the polygonal prism is a flat surface that corresponds to a gripping surface of the gripping means for gripping and transporting the cap.

Images