JP7511974B2 - Container cap and method for manufacturing the same - Google Patents

Description

The present invention relates to a container cap that is attached to the mouth of a container body that contains contents and allows the contents to be poured out, and a method for manufacturing the container cap.

As a container for storing liquids such as food seasonings, powders, or granules, a container that includes a container body that stores the contents and a container cap that has a spout for pouring the contents is known. For example, Patent Document 1 discloses a cap that includes a cap body with a spout and a top lid that is attached to the cap body by screw engagement so as to be freely opened and closed, and the spout is provided with a sealing plug and a pull ring for opening the sealing plug.

Patent No. 6319500

However, with the cap described in Patent Document 1, after opening the top lid, it is necessary to remove the sealing stopper by pulling the pull ring, which is time-consuming and can be difficult for users with weak strength to remove the sealing stopper, leaving room for improvement.

The present invention aims to solve these problems, and its objective is to provide a container cap that can be opened with a simple operation while ensuring airtightness when the container is unused, and a method for manufacturing the container cap.

The container cap of the present disclosure comprises:
A container cap that can be attached to a container body having a storage space for contents,
a cap body having a pouring outlet for pouring the contents from the storage space and attached to the mouth of the container body;
An openable and closable lid for covering the spout;
a plug body that is connected to the radially inner side of the spout through a weakened portion and closes the spout,
A top wall of the lid body is provided with a lid body opening penetrating the top wall and a lid body recess formed to be connected to an upper portion of the lid body opening and wider than the lid body opening,
a protrusion protruding radially outward from the plug fits into the lid recess, so that the plug engages with a peripheral edge of the lid opening ,
The upper surface of the annular protrusion that forms the peripheral edge of the lid opening is formed with an engagement uneven portion that is a convex portion and/or a concave portion for strengthening the engagement with the protrusion .

In addition, in the above-described configuration of the container cap of the present disclosure, the plug has a blocking portion that is connected to the weakened portion and blocks the spout, and an erected portion that stands upward from the blocking portion and engages with the lid opening, and it is preferable that the protruding portion that protrudes radially outward and engages with the lid opening in an undercut manner is provided at the upper portion of the erected portion.

In addition, in the above-described configuration of the container cap of the present disclosure, it is preferable that the upright portion includes a base portion and a tip portion that is connected to the upper portion of the base portion and is formed narrower than the base portion, and that the stopper engages with the peripheral portion of the lid opening by fitting an annular protrusion that forms the peripheral portion of the lid opening in the top wall between the protrusion and the upper portion of the base portion.

In addition, in the container cap of the present disclosure, in the above configuration, it is preferable that the engagement uneven portion has a generally step shape that protrudes upward more on the radially inner side.

In addition, in the container cap of the present disclosure, in the above configuration, it is preferable that the engagement uneven portion has an inclined portion that inclines upward toward the inside in the radial direction.

In addition, in the container cap of the present disclosure, in the above configuration, it is preferable that the engagement uneven portion has repeated unevenness in the circumferential direction.

The present disclosure makes it possible to provide a container cap that can be opened with a simple operation while ensuring airtightness when the container is unused, and a method for manufacturing the container cap.

1 is a front cross-sectional view showing an unused container in which a container cap according to one embodiment of the present invention is attached to a container body. 1 is a plan view of a container cap (excluding a lid body) according to one embodiment of the present invention. 1 is a front cross-sectional view of a container cap according to one embodiment of the present invention, showing the state in which the plug is torn off from the container cap by opening the lid body, thereby opening the spout. 2 is a flowchart showing the steps of a method for manufacturing a container cap according to one embodiment of the present invention. 4 is a front cross-sectional view showing a step of engaging the plug with the lid in the container cap according to one embodiment of the present invention. FIG. 1 is a front cross-sectional view showing an unused container in which a first modified example of a container cap according to one embodiment of the present invention is attached to a container body. 10 is a front cross-sectional view showing a step of engaging the plug with the lid in a first modified example of a container cap according to an embodiment of the present invention. FIG. 1 is a front cross-sectional view showing an unused container in which a second modified example of a container cap according to one embodiment of the present invention is attached to a container body. 11 is a front cross-sectional view showing a step of engaging the plug with the lid in a second modified example of a container cap according to an embodiment of the present invention. FIG. 11 is a front cross-sectional view showing an unused container with a third modified example of a container cap according to one embodiment of the present invention attached to a container body. FIG. A front cross-sectional view showing a step of engaging the plug with the lid in a third modified example of a container cap according to an embodiment of the present invention. A front cross-sectional view showing an unused container in which a fourth modified example of a container cap according to one embodiment of the present invention is attached to a container body. A front cross-sectional view showing a step of engaging the plug with the lid in a fourth modified example of a container cap according to an embodiment of the present invention. A front cross-sectional view showing an unused container in which a fifth modified example of a container cap according to one embodiment of the present invention is attached to a container body. A front cross-sectional view showing a step of engaging the plug with the lid in a fifth modified example of a container cap according to one embodiment of the present invention.

The present invention will now be described in more detail with reference to the drawings.

Figure 1 shows a container cap 1 according to one embodiment of the present invention attached to a compatible container body 2. In this specification, claims, abstract and drawings, the side on which the lid 50 described below is located is referred to as the upper side (upper side in Figure 1), and the side on which the container body 2 is located is referred to as the lower side (lower side in Figure 1). In addition, the radially outward direction refers to the direction along a straight line passing through the central axis O1 of the container cap 1 in Figure 1 and perpendicular to the central axis O1 toward the opposite side to the central axis O1, and the radially inward direction refers to the direction along the straight line toward the central axis O1. The container cap 1 according to this embodiment comprises a cap body 10 and a lid 50.

First, the container body 2 will be described. The container body 2 used in this embodiment has a cylindrical mouth 4, a body (not shown) connected to the lower end of the mouth 4, and a bottom that closes the lower end of the body. In this embodiment, the container body 2 is formed by extrusion blow molding a parison made of a synthetic resin material. The material constituting the container body 2 is low-density polyethylene (LDPE) or high-density polyethylene resin (HDPE), and in particular, when LDPE is used, high squeezability can be imparted. However, this is not limited to this embodiment, and for example, when the container body 2 is formed by biaxial stretch blow molding, the material constituting the container body 2 may be polyethylene terephthalate (PET), etc.

As shown in FIG. 1, the container body 2 has a storage space S inside for storing the contents.

As shown in FIG. 1, the outer peripheral surface of the mouth portion 4 is provided with an annular convex portion 4a for undercut engagement with an engaging protrusion wall 11a provided on the outer peripheral wall 11 of the cap body 10 described below. Also, a sealing wall 16 provided on the cap body 10 described below fits into the inner peripheral surface of the mouth portion 4. In this way, the container body 2 can firmly fix the cap body 10 by sandwiching the mouth portion 4 between the outer peripheral wall 11 and the sealing wall 16 and by undercut engagement of the annular convex portion 4a with the engaging protrusion wall 11a.

Next, the cap body 10 constituting the container cap 1 will be described. The cap body 10 has an outer peripheral wall 11 surrounding the mouth portion 4, and an engaging protrusion wall 11a that undercut-engages with the annular protrusion 4a of the mouth portion 4 is formed on the inner peripheral surface of the outer peripheral wall 11. An inner peripheral wall 12 is provided on the upper inner peripheral side of the outer peripheral wall 11, and a top wall 13 is integrally connected to the inside of the inner peripheral wall 12. A pouring tube 14 that defines a pouring outlet 14a for pouring out the contents is provided on the upper surface of the top wall 13. An engaging ring 13b and an engaging protrusion 13a are provided on the outer peripheral end of the top wall 13, and when the lid body 50 is closed, a lid body protrusion 57 provided on the inner peripheral surface of the lid body peripheral wall 53 of the lid body 50 undercut-engages with the engaging protrusion 13a to fix the lid body 50 to the cap body 10. The outer peripheral wall 11 is integrally connected to the lid body 50 via a hinge portion 40 as shown in FIG. 1. The hinge portion 40 connects the lid body 50 (described later) to the cap body 10 in an openable and closable manner.

In this embodiment, the inner tube 54 provided on the underside of the top wall 52 of the lid 50 (described later) abuts against the inner peripheral surface of the pouring tube 14, so that the pouring outlet 14a is liquid-tightly sealed when the lid 50 is closed.

As shown in FIG. 1, a slit groove 12g is formed between the outer peripheral wall 11 and the inner peripheral wall 12. As shown in FIG. 1 and FIG. 2, the outer peripheral wall 11 and the inner peripheral wall 12 are connected via the first weakened portion 12c1, the second weakened portion 12c2, the third weakened portion 12c3, and the stationary connecting portion 12f. As can be seen from FIG. 2, the second weakened portion 12c2 has a larger radial width than the first weakened portion 12c1, and the third weakened portion 12c3 has an even larger radial width than the second weakened portion 12c2.

As shown in Figure 2, the outer peripheral wall 11 has a cutout portion 12ct at one location in the circumferential direction near the hinge portion 40. This cutout portion 12ct has a V-shape in plan view as shown in Figure 2, and is cut into the lower end portion leaving a thin bottom wall. At a position corresponding to the cutout portion 12ct of the engagement protruding wall 11a, an inner peripheral cutout portion (not shown) is provided vertically to form a vertical weakened portion. A slit groove 12g is provided in the circumferential direction from the end face of the cutout portion 12ct starting from the first weakened portion 12c1 (slit) on the inner side, and extends over approximately 345° from the end face. With this configuration, a user can open the lid 50, grasp the lid 50, and pull it radially outward to cut one end of the first weakened portion 12c1 starting from the notch 12ct provided near the hinge portion 40, and then cut the first weakened portion 12c1, the second weakened portion 12c2, and the third weakened portion 12c3 in that order. This allows the user to easily separate almost all of the outer peripheral wall 11, except for the area near the steady connection portion 12f, from the cap body 10 and pull it radially outward. Therefore, the clamping of the mouth portion 4 between the outer peripheral wall 11 and the seal wall 16 can be released, and the container cap 1 can be easily separated from the container body 2.

Here, an example has been described in which cutting is performed from the first weakened portion 12c1 through the second weakened portion 12c2 to the third weakened portion 12c3, but in the example of FIG. 2, by cutting the first weakened portion 12c1 and the second weakened portion 12c2, more than half of the outer peripheral wall 11 can be separated from the cap body 10. Therefore, with only the first weakened portion 12c1 and the second weakened portion 12c2 cut, the container cap 1 can be removed from the container body 2 by pulling the outer peripheral wall 11 radially outward.

As shown in Figs. 1 and 2, a partition wall 15h is integrally formed on the inner peripheral surface of the dispensing tube 14, and the stopper body 15 that blocks the dispensing outlet 14a is connected to the partition wall 15h via the weakened portion 15b. When the container is in an unused state in which the weakened portion 15b is not broken as shown in Fig. 1, the stopper body 15 blocks the dispensing outlet 14a. By checking whether the weakened portion 15b is broken or not, it is possible to determine whether the container to which the container cap 1 is attached is unopened or not. In other words, in this embodiment, the weakened portion 15b has an unopened guarantee function. This weakened portion 15b has a cross-sectional area large enough to be broken by the user applying a predetermined force when opening the lid body 50 of an unused container.

As shown in Figs. 1 and 2, the plug 15 includes a flat blocking portion 15f that is connected to the weakened portion 15b and blocks the spout 14a, and an upright portion 15c that is upright from the blocking portion 15f. The upright portion 15c has a generally topped cylindrical shape and includes a base portion 15c1 that is connected to the blocking portion 15f, and a tip portion 15c2 that is connected to the top of the base portion 15c1 and is formed to be narrower than the base portion 15c1. The tip portion 15c2 includes a protruding portion 15a that protrudes radially outward at its upper portion. The protruding portion 15a is undercut-engaged with an annular protruding portion 52c on the periphery of the lid opening 52a on the lid 50 side, which will be described later, so that the plug 15 is firmly fixed to the lid 50. At this time, as shown in Fig. 1, the annular protruding portion 52c is fitted between the protruding portion 15a and the upper portion of the base portion 15c1.

In addition, a tensile rib 15e extending in the vertical direction is provided on the side of the erected portion 15c on the hinge portion 40 side. This tensile rib 15e plays a role in transmitting the upward pulling force to the weakened portion 15b on the hinge portion 40 side when the plug 15 is lifted together with the lid 50 when the lid 50 is lifted and opened from the unused state of the container in which the weakened portion 15b is not broken as shown in FIG. 1. In addition, by providing the tensile rib 15e on the side (hinge portion 40 side) of the erected portion 15c, stress is concentrated near the weakened portion 15b that is beginning to break when the lid 50 is opened, making it easier to break the weakened portion 15b. This tensile rib 15e makes it easy to cut the weakened portion 15b on the hinge portion 40 side when the lid 50 is lifted from the state shown in FIG. 1.

As shown in FIG. 1, the lid body 50 is connected to the upper end of the outer peripheral wall 11 of the cap body 10 via a hinge portion 40, and the dispensing tube 14 can be covered and hidden by bending the hinge portion 40. In addition, a lid body protrusion 57 is provided on the inner surface of the peripheral wall of the lid body 50 (lid body peripheral wall 53). When the lid body 50 is closed, the lid body protrusion 57 undercut-engages with the engagement protrusion 13a of the engagement ring 13b, and the lid body 50 is fixed to the cap body 10.

At a position (horizontal direction) corresponding to the erected portion 15c in the lid 50, a lid opening 52a is provided penetrating the top wall 52. The protrusion 15a protruding radially outward from the upper portion of the erected portion 15c (tip portion 15c2) is undercut and fixed to the annular protrusion 52c formed on the periphery of the lid opening 52a. That is, as shown in FIG. 1, a lid recess 52b (see FIG. 5) formed wider than the lid opening 52a is formed at the upper portion of the lid opening 52a, and the above-mentioned protrusion 15a enters this lid recess 52b, whereby the plug 15 engages with the annular protrusion 52c on the periphery of the lid opening 52a. As shown in Fig. 1, the engagement between the annular protrusion 52c and the protrusion 15a is such that their contact surfaces form a substantially horizontal plane, and after the plug 15 is formed so that they engage with each other using a plug engagement tool 70 (see Fig. 5) described later, the engagement is strong and cannot be released. More specifically, the engagement between the annular protrusion 52c and the protrusion 15a cannot be released unless the erected portion 15c is pressed with a pressing force greater than the tensile force required to break the weakened portion 15b.

In this embodiment, the lower surface of the protruding portion 15a abuts against the upper surface of the annular protrusion 52c of the top wall 52, and the outer surface of the protruding portion 15a abuts against the outer peripheral edge of the lid recess 52b. With this configuration, even after the weakened portion 15b connecting the stopper body 15 and the dispensing tube 14 breaks, the top wall 52 and the erected portion 15c are liquid-tightly sealed on at least two surfaces, so that the contents can be effectively prevented from leaking out of the dispensing tube 14.

In particular, in this embodiment, the annular protrusion 52c, which is the peripheral portion of the lid opening 52a, is configured to fit between the protruding portion 15a and the upper portion of the base portion 15c1, so that even after the weakened portion 15b breaks, the plug 15 is unlikely to move upward or downward relative to the top wall 52 of the lid 50. Therefore, the sealing effect between the top wall 52 and the erected portion 15c can be maintained.

Furthermore, in this embodiment, the protrusion 15a fits into the lid recess 52b to engage the plug 15 and the lid 50, so the plug 15 does not protrude above the top wall 52 of the lid 50. This prevents the appearance of the lid 50 from being marred.

The material of the container cap 1 and the lid body 50 can be, for example, linear low-density polyethylene (LLDPE). However, this is not limited to the above, and the material of the container cap 1 and the lid body 50 can be other polyethylenes (PE) such as low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), or synthetic resin materials such as polypropylene (PP) (random PP, block PP, homo PP).

When using the contents in the container body 2 for the first time, the user pinches the knob 51 of the lid 50 with his/her fingers and rotates the lid 50 around the hinge 40 in the clockwise direction in FIG. 1 to open it from the state shown in FIG. 1. At this time, the stopper 15 is already firmly engaged and fixed to the lid 50, so when the user opens the lid 50 with a force greater than a predetermined value, the weakened portion 15b connecting the stopper 15 and the dispensing tube 14 is cut, and the stopper 15 is separated from the dispensing tube 14 in a state where it is integrated with the lid 50, as shown in FIG. 3. This opens the dispensing outlet 14a, making it possible for the user to use the contents. Therefore, while the stopper 15 ensures sealing in an unused state, it is possible to open the container by a simple operation of pinching and pulling up the lid 50. The operation of pulling up the lid 50 places less strain on the fingers than the operation of pulling the pull ring to open the container, making it easier for the user to operate.

The user can also recognize that the container has been opened by visually confirming that the weakened portion 15b, which has an unopened guarantee function, has been broken, as shown in Figure 3.

As shown in FIG. 1, the underside of the closure portion 15f of the plug body 15 has a deformable wing portion 15j that extends downward and radially outward on the outer periphery close to the weakened portion 15b. The tip of the wing portion 15j is provided so as to extend radially outward beyond the radial position of the weakened portion 15b. In this embodiment, the wing portion 15j is provided so as to be curved outward, making it easy to bend.

With this configuration, when the lid 50 is closed after breaking the weakened portion 15b and opening it, the wing portion 15j bends while abutting against the upper portion of the partition wall 15h, thereby sealing the gap in the weakened portion 15b that was created by opening the lid.

Next, the procedure for manufacturing the unused container cap 1 shown in FIG. 1 by engaging the protruding portion 15a of the plug body 15 with the annular protrusion 52c of the lid body 50 will be described with reference to FIG. 4 and FIG. 5.

First, the manufacturer prepares the container cap 1 in an initial state before engaging the stopper 15 with the lid 50, which is formed by injection molding or the like, as shown in FIG. 5 (step S101 in FIG. 4). In the initial state, the container cap 1 has no protrusion 15a formed on the erected portion 15c, and the upper portion of the tip 15c2 of the erected portion 15c is an upper wall forming material 15g1 having a substantially truncated cone shape, as shown in FIG. 5. As shown in FIG. 5, the hinge portion 40 is folded back to move the lid 50 to a position covering the spout 14a, and the upper portion of the upper wall forming material 15g1 is projected upward through the lid opening 52a, and then the container cap 1 is set on the stopper engaging jig 70 shown in FIG. 5 (step S102 in FIG. 4).

With the plug 15's blocking portion 15f supported by the lower jig 73 of the plug engagement jig 70, the upper jig 71 (heating plate) of the plug engagement jig 70 shown in FIG. 5 presses and heats the upper wall forming material 15g1 of the standing portion 15c from above (step S103 in FIG. 4). As a result, the upper wall forming material 15g1 heated by the upper jig 71 is melted by the heat from the upper jig 71 and spreads radially outward. It then deforms until it is approximately the same height as the upper surface of the top wall 52 of the lid 50, becoming the upper wall portion 15g2 shown in FIG. 1. In addition, the side of the upper wall forming material 15g1 enters the lid recess 52b provided above the annular protrusion 52c, and is formed as the protrusion 15a protruding radially outward (step S104 in FIG. 4). As a result, the erected portion 15c (protrusion 15a) of the plug 15 enters the lid recess 52b and engages with the annular protrusion 52c on the periphery of the lid opening 52a in an undercut manner. Also, as shown in FIG. 1, the annular protrusion 52c of the top wall 52 fits between the protrusion 15a and the base portion 15c1, so the plug 15 is fixed so that it cannot slip out of the lid opening 52a in either the upward or downward direction.

The stopper 15 is thermoformed and engaged and fixed to the lid 50 using the stopper engagement tool 70 shown in Figure 5, and then the cap body 10 is attached to the mouth 4 of the container body 2 filled with the contents, thereby completing the unused container shown in Figure 1.
(First Modification)

Next, a container cap 101, which is a first modified example of this embodiment, will be described with reference to Figures 6 and 7. This first modified example is similar to the configuration of this embodiment, except that an engagement uneven portion 52c1 is provided on the upper surface of the annular protrusion 52c to strengthen the engagement with the protrusion 15a. Therefore, the following description will focus on the differences from this embodiment.

The upper surface of the annular protrusion 52c according to the first modification is slightly inclined upward toward the radial inside. The engagement unevenness 52c1 formed on the upper surface of the annular protrusion 52c protrudes upward at the radial inside end of the annular protrusion 52c as shown in FIG. 6, and has a substantially step shape. In this specification, claims, and drawings, the term "step shape" refers to a so-called staircase shape in which the height position relative to the horizontal position can be expressed using a step function. The engagement unevenness 52c1 may have a surface that is slightly inclined with respect to the horizontal or vertical direction, and may be substantially step-shaped. As described later, the lid recess 52b provided above the annular protrusion 52c is filled with the molten upper wall forming material 15g1 to form a protrusion 15a having a shape complementary to the engagement unevenness 52c1. With this configuration, the engagement unevenness 52c1 and the protrusion 15a according to the first modification can make it difficult for the protrusion 15a to come off the annular protrusion 52c by interlocking the protrusions and recesses provided on the engagement unevenness 52c1 and the protrusion 15a. In addition, the complementary shapes of the engagement unevenness 52c1 and the protrusion 15a increase the contact area, thereby increasing the adhesive strength of the protrusion 15a to the annular protrusion 52c. In particular, in the first modification, the engagement unevenness 52c1 protrudes upward at the radial inner end of the annular protrusion 52c, so that the contact area between the annular protrusion 52c and the erected portion 15c can be further increased to increase the adhesive strength.

Figure 7 shows the container cap 101 according to the first modified example, which is formed by injection molding or the like and is in an initial state before the plug 15 is engaged with the lid 50, set in the plug engagement jig 70.

With the plug 15's blocking portion 15f supported by the lower jig 73 of the plug engagement jig 70, the upper jig 71 (heating plate) of the plug engagement jig 70 shown in FIG. 7 presses and heats the upper wall forming material 15g1 of the erected portion 15c from above. As a result, the upper wall forming material 15g1 heated by the upper jig 71 is melted by the heat from the upper jig 71 and spreads radially outward. It then deforms until it is approximately the same height as the upper surface of the top wall 52 of the lid 50, becoming the upper wall portion 15g2 shown in FIG. 6. In addition, the side of the upper wall forming material 15g1 enters the lid recess 52b provided above the annular protrusion 52c, and is formed as a protrusion 15a having a shape complementary to the engagement uneven portion 52c1. As a result, the erected portion 15c (protrusion 15a) of the plug 15 enters the lid recess 52b and engages with the annular protrusion 52c on the periphery of the lid opening 52a in an undercut manner. Also, as shown in FIG. 6, the annular protrusion 52c of the top wall 52 fits between the protrusion 15a and the base portion 15c1, so the plug 15 is fixed so that it cannot slip out of the lid opening 52a in either the upward or downward direction.

In the first modified example, the complementary shapes between the engaging uneven portion 52c1 and the protrusion 15a between the lower surface of the protrusion 15a and the upper surface of the annular protrusion 52c not only improve the sealing performance but also increase the adhesive strength between the two.
(Second Modification)

Next, a container cap 102, which is a second modified example of this embodiment, will be described with reference to Figures 8 and 9. This second modified example is similar to the configuration of this embodiment, except that an engagement uneven portion 52c2 is provided on the upper surface of the annular protrusion 52c to strengthen the engagement with the protrusion 15a. Therefore, the following description will focus on the differences from this embodiment.

The upper surface of the annular protrusion 52c according to the second modification is slightly inclined upward toward the radial inside. The engagement unevenness 52c2 formed on the upper surface of the annular protrusion 52c has a substantially step shape in which the height of the convex portion protruding upward toward the radial inside of the annular protrusion 52c increases, as shown in FIG. 8. That is, the engagement unevenness 52c2 according to the second modification includes an inner convex portion 52p1 protruding upward at the radial inner end of the annular protrusion 52c, and an outer convex portion 52p2 provided adjacent to the radial outside of the inner convex portion 52p1. The outer convex portion 52p2 has a lower protruding height than the inner convex portion 52p1, and a step is provided. The engagement unevenness 52c2 may have a surface that is slightly inclined with respect to the horizontal or vertical direction and may be substantially step-shaped. The outer convex portion 52p2 is provided intermittently in the circumferential direction, and is configured so that the unevenness is repeated. The outer convex portion 52p2 does not need to be provided intermittently in the circumferential direction, and may be formed in an annular shape. As described later, the molten upper wall forming material 15g1 enters the cover recess 52b provided above the annular protrusion 52c to form a protrusion 15a having a shape complementary to the engagement concave portion 52c2. With this configuration, the engagement concave portion 52c2 and the protrusion 15a according to the second modified example can make the protrusion 15a less likely to come off the annular protrusion 52c compared to the configuration according to this embodiment, as the convex and concave portions provided on the engagement concave portion 52c2 and the protrusion 15a interlock with each other. In addition, the contact area is increased by the complementary shapes of the engagement concave portion 52c2 and the protrusion 15a, so that the adhesive strength of the protrusion 15a to the annular protrusion 52c can be increased. In particular, in the second modified example, the engagement unevenness 52c2 is configured in a stepped shape so that the height of the convexity protruding upward toward the inside in the radial direction increases, and the outer convexity 52p2 is arranged intermittently in the circumferential direction so that the unevenness is repeated. Therefore, the contact area between the annular protrusion 52c and the erected portion 15c is increased, and the contact area between the annular protrusion 52c and the protruding portion 15a is also increased, thereby improving the adhesive strength and sealing properties.

Figure 9 shows the container cap 102 according to the second modified example, which is formed by injection molding or the like and is in its initial state before the plug 15 is engaged with the lid 50, set in the plug engagement jig 70.

With the plug 15's blocking portion 15f supported by the lower jig 73 of the plug engagement jig 70, the upper jig 71 (heating plate) of the plug engagement jig 70 shown in FIG. 9 presses and heats the upper wall forming material 15g1 of the erected portion 15c from above. As a result, the upper wall forming material 15g1 heated by the upper jig 71 is melted by the heat from the upper jig 71 and spreads radially outward. It then deforms until it is approximately the same height as the upper surface of the top wall 52 of the lid 50, becoming the upper wall portion 15g2 shown in FIG. 8. In addition, the side of the upper wall forming material 15g1 enters the lid recess 52b provided above the annular protrusion 52c, and is formed as a protrusion 15a having a shape complementary to the engagement uneven portion 52c2. As a result, the erected portion 15c (protrusion 15a) of the plug 15 enters the lid recess 52b and engages with the annular protrusion 52c on the periphery of the lid opening 52a in an undercut manner. Also, as shown in FIG. 8, the annular protrusion 52c of the top wall 52 fits between the protrusion 15a and the base portion 15c1, so the plug 15 is fixed so that it cannot slip out of the lid opening 52a in either the upward or downward direction.

In the second modification, the engagement uneven portion 52c2 is configured in a stepped shape so that the height of the protrusions protruding upward toward the inside in the radial direction increases, and the outer protrusions 52p2 are provided intermittently in the circumferential direction so that the unevenness is repeated. Therefore, the contact area between the annular protrusion 52c and the standing portion 15c is increased, and the contact area between the annular protrusion 52c and the protruding portion 15a is also increased, thereby improving the adhesive strength and sealing performance.
(Third Modification)

Next, a container cap 103, which is a third modified example of this embodiment, will be described with reference to Figures 10 and 11. This third modified example is similar to the configuration of this embodiment, except that an engagement uneven portion 52c3 is provided on the upper surface of the annular protrusion 52c to strengthen the engagement with the protrusion 15a. Therefore, the following description will focus on the differences from this embodiment.

The upper surface of the annular protrusion 52c according to the third modified example is configured as an inclined portion that inclines upward toward the inside in the radial direction. As described later, the molten upper wall forming material 15g1 enters the cover recess 52b provided above the annular protrusion 52c to form a protrusion 15a having a shape complementary to the engagement uneven portion 52c3. With this configuration, the engagement uneven portion 52c3 and the protrusion 15a according to the third modified example can make the protrusion 15a less likely to come off the annular protrusion 52c compared to the configuration according to this embodiment, as the convex and concave portions provided on the engagement uneven portion 52c3 and the protrusion 15a intertwine with each other. In addition, the contact area is increased by the complementary shapes of the engagement uneven portion 52c3 and the protrusion 15a, so the adhesive strength of the protrusion 15a to the annular protrusion 52c can be increased. In particular, in the third modified example, the engagement uneven portion 52c3 is configured as an inclined surface that slopes upward toward the inside in the radial direction, which increases the contact area between the annular protrusion 52c and the erected portion 15c, and also increases the contact area between the annular protrusion 52c and the protruding portion 15a, thereby improving the adhesive strength and sealing performance.

Figure 11 shows the container cap 103 according to the third modified example, which is formed by injection molding or the like and is in an initial state before the plug 15 is engaged with the lid 50, set in the plug engagement jig 70.

With the plug 15's blocking portion 15f supported by the lower jig 73 of the plug engagement jig 70, the upper jig 71 (heating plate) of the plug engagement jig 70 shown in FIG. 11 presses and heats the upper wall forming material 15g1 of the erected portion 15c from above. As a result, the upper wall forming material 15g1 heated by the upper jig 71 is melted by the heat from the upper jig 71 and spreads radially outward. It then deforms until it is approximately the same height as the upper surface of the top wall 52 of the lid 50, becoming the upper wall portion 15g2 shown in FIG. 10. In addition, the side of the upper wall forming material 15g1 enters the lid recess 52b provided above the annular protrusion 52c, and is formed as a protrusion 15a having a shape complementary to the engagement uneven portion 52c3. As a result, the erected portion 15c (protrusion 15a) of the plug 15 enters the lid recess 52b and engages with the annular protrusion 52c on the periphery of the lid opening 52a in an undercut manner. Also, as shown in FIG. 10, the annular protrusion 52c of the top wall 52 fits between the protrusion 15a and the base portion 15c1, so the plug 15 is fixed so that it cannot slip out of the lid opening 52a in either the upward or downward direction.

In the third modified example, the engaging uneven portion 52c3 is configured in a mountain shape having an inclined surface that slopes upward radially inward, thereby increasing the contact area between the annular protrusion 52c and the standing portion 15c, and also increasing the contact area between the annular protrusion 52c and the protruding portion 15a, thereby improving the adhesive strength and sealing performance.
(Fourth Modification)

Next, a container cap 104, which is a fourth modified example of this embodiment, will be described with reference to Figures 12 and 13. This fourth modified example is similar to the configuration of this embodiment, except that an engagement uneven portion 52c4 is provided on the upper surface of the annular protrusion 52c to strengthen the engagement with the protrusion 15a. Therefore, the following description will focus on the differences from this embodiment.

On the upper surface of the annular protrusion 52c according to the fourth modification, a hook-shaped engagement uneven portion 52c4 is formed, which includes a column portion protruding upward from the radial inner end and an arm portion extending further radially outward from the upper end of the column portion. As described later, the molten upper wall forming material 15g1 enters the cover recess 52b provided above the annular protrusion 52c to form a protrusion 15a having a shape complementary to the engagement uneven portion 52c4. With this configuration, the engagement uneven portion 52c4 and the protrusion 15a according to the fourth modification can make the protrusion 15a less likely to come off the annular protrusion 52c compared to the configuration according to this embodiment, as the convex and concave portions provided on the engagement uneven portion 52c4 and the protrusion 15a intertwine with each other. In addition, the contact area is increased due to the complementary shapes of the engagement uneven portion 52c4 and the protrusion 15a, so that the adhesive strength of the protrusion 15a to the annular protrusion 52c can be increased. In particular, in the fourth modified example, the engaging uneven portion 52c4 is configured in a hook shape with a column portion that protrudes upward from the radially inner end and an arm portion that extends further radially outward from the upper end of the column portion, thereby increasing the contact area between the annular protrusion 52c and the erected portion 15c, and also increasing the contact area between the annular protrusion 52c and the protrusion 15a, thereby improving the adhesive strength and sealing properties.

Figure 13 shows the container cap 104 according to the fourth modified example, which is formed by injection molding or the like and is in an initial state before the plug 15 is engaged with the lid 50, set in the plug engagement jig 70.

With the plug 15 being supported by the lower jig 73 of the plug engagement jig 70, the upper wall forming material 15g1 of the erected portion 15c is heated while being pressed from above by the upper jig 71 (heating plate) of the plug engagement jig 70 shown in FIG. 13. As a result, the upper wall forming material 15g1 heated by the upper jig 71 is melted by the heat from the upper jig 71 and spread radially outward. In the initial state of the container cap 104 according to the fourth modified example, the engagement uneven portion 52c4 is configured as a convex portion extending upward from the radial inner circumferential end of the annular protrusion 52c, and the upper end of the convex portion extends upward beyond the upper surface of the top wall 52. Therefore, the engagement uneven portion 52c4 in the initial state is also bent radially outward by the heat from the upper jig 71. The upper end of the upper wall forming material 15g1 and the engaging uneven portion 52c4 deforms until it is approximately flush with the upper surface of the top wall 52 of the lid body 50, forming the upper wall portion 15g2 and the engaging uneven portion 52c4 shown in FIG. 10. The side of the upper wall forming material 15g1 enters the lid body recess 52b provided above the annular protrusion 52c, and is formed as a protrusion 15a having a shape complementary to the engaging uneven portion 52c4. As a result, the erected portion 15c (protrusion 15a) of the plug body 15 enters the lid body recess 52b and engages with the annular protrusion 52c on the periphery of the lid body opening 52a by undercut. Also, as shown in FIG. 12, the annular protrusion 52c of the top wall 52 fits between the protrusion 15a and the base portion 15c1, so that the plug body 15 is fixed so that it cannot slip out of the lid body opening 52a either upward or downward.

In the fourth modified example, the engaging uneven portion 52c4 is configured in a hook shape having a column portion protruding upward from the radially inner end and an arm portion extending further radially outward from the upper end of the column portion, thereby increasing the contact area between the annular protrusion 52c and the standing portion 15c, and also increasing the contact area between the annular protrusion 52c and the protrusion 15a, thereby improving the adhesive strength and sealing performance.
(Fifth Modification)

Next, a container cap 105, which is a fifth variation of this embodiment, will be described with reference to Figures 14 and 15. This fifth variation is similar to the configuration of this embodiment, except that an engagement uneven portion 52c5 is provided on the upper surface of the annular protrusion 52c to strengthen the engagement with the protrusion 15a. Therefore, the following description will focus on the differences from this embodiment.

The engagement unevenness 52c5 formed on the upper surface of the annular protrusion 52c according to the fifth modification has a substantially step-shaped shape in which the height of the protrusion protruding upward toward the radial inside of the annular protrusion 52c increases, as shown in FIG. 14. That is, the engagement unevenness 52c5 according to the fifth modification has an inner protrusion 52p3 protruding upward at the radial inside end of the annular protrusion 52c, and an outer protrusion 52p4 provided adjacent to the radial outside of the inner protrusion 52p3. The outer protrusion 52p4 has a lower protrusion height than the inner protrusion 52p3, and a step is provided. The engagement unevenness 52c5 may have a surface that is slightly inclined with respect to the horizontal or vertical direction and may have a substantially step-shaped shape. The outer protrusion 52p4 is provided intermittently in the circumferential direction, and is configured so that the unevenness is repeated. In the fifth modified example, unlike the second modified example, the outer convex portion 52p4 is provided so as to be continuous with the side wall of the outer peripheral end of the cover recess 52b. The outer convex portion 52p4 does not need to be provided intermittently in the circumferential direction, and may be formed in an annular shape. As described later, the molten upper wall forming material 15g1 enters the cover recess 52b provided above the annular protrusion 52c to form a protrusion 15a having a shape complementary to the engagement concave-convex portion 52c5. With this configuration, the engagement concave-convex portion 52c5 and the protrusion 15a according to the fifth modified example can make the protrusion 15a less likely to come off the annular protrusion 52c compared to the configuration according to this embodiment, by interlocking the convex and concave portions provided on the engagement concave-convex portion 52c5 and the protrusion 15a. In addition, the contact area is increased by the complementary shapes of the engagement concave-convex portion 52c5 and the protrusion 15a, so that the adhesive strength of the protrusion 15a to the annular protrusion 52c can be increased. In particular, in the fifth modified example, the engagement unevenness 52c5 is configured in a stepped shape so that the height of the convexity protruding upward toward the inside in the radial direction increases, and the outer convexity 52p4 is arranged intermittently in the circumferential direction so that the unevenness is repeated. Therefore, the contact area between the annular protrusion 52c and the erected portion 15c is increased, and the contact area between the annular protrusion 52c and the protruding portion 15a is also increased, thereby improving the adhesive strength and sealing performance.

Figure 15 shows the container cap 105 according to the fifth modified example, which is formed by injection molding or the like and is in an initial state before the plug 15 is engaged with the lid 50, set in the plug engagement jig 70.

With the plug 15's blocking portion 15f supported by the lower jig 73 of the plug engagement jig 70, the upper jig 71 (heating plate) of the plug engagement jig 70 shown in FIG. 15 presses and heats the upper wall forming material 15g1 of the erected portion 15c from above. As a result, the upper wall forming material 15g1 heated by the upper jig 71 is melted by the heat from the upper jig 71 and spreads radially outward. It then deforms until it is approximately the same height as the upper surface of the top wall 52 of the lid 50, becoming the upper wall portion 15g2 shown in FIG. 14. In addition, the side of the upper wall forming material 15g1 enters the lid recess 52b provided above the annular protrusion 52c, and is formed as a protrusion 15a having a shape complementary to the engagement uneven portion 52c5. As a result, the erected portion 15c (protrusion 15a) of the plug 15 enters the lid recess 52b and engages with the annular protrusion 52c on the periphery of the lid opening 52a in an undercut manner. Also, as shown in FIG. 14, the annular protrusion 52c of the top wall 52 fits between the protrusion 15a and the base portion 15c1, so the plug 15 is fixed so that it cannot slip out of the lid opening 52a in either the upward or downward direction.

In the fifth modified example, the engagement unevenness 52c5 is configured in a stepped shape so that the height of the convexity protruding upward toward the inside in the radial direction increases, and the outer convexity 52p4 is arranged intermittently in the circumferential direction so that the unevenness is repeated. Therefore, the contact area between the annular protrusion 52c and the erected portion 15c is increased, and the contact area between the annular protrusion 52c and the protruding portion 15a is also increased, thereby improving the adhesive strength and sealing performance.

As described above, this embodiment relates to a container cap 1 that can be attached to a container body 2 having a storage space S for contents, and includes a cap body 10 that has a pouring outlet 14a for pouring out the contents from the storage space S and is attached to the mouth 4 of the container body 2, an openable and closable lid body 50 that covers the pouring outlet 14a, and a stopper body 15 that is connected to the radially inward side of the pouring outlet 14a via a weakened portion 15b and closes the pouring outlet 14a, and the top wall 52 of the lid body 50 is provided with a lid body opening 52a that penetrates the top wall 52 and a lid body recess 52b that is connected to the upper part of the lid body opening 52a and is formed to be wider than the lid body opening 52a, and the stopper body 15 is configured to engage with the peripheral portion of the lid body opening 52a by the protrusion 15a that protrudes radially outward in the stopper body 15 fitting into the lid body recess 52b. By adopting such a configuration, in the unused container cap 1, the stopper body 15, which is connected to the pouring tube 14 via the weakened portion 15b and closes the pouring outlet 14a, is fixed to the lid body 50, and the stopper body 15 can be moved together with the lid body 50 by pinching and rotating the lid body 50 around the hinge portion 40 to easily open the pouring outlet 14a. Therefore, while the stopper body 15 ensures sealing in the unused state, it is possible to open the container cap 1 by a simple operation of pinching and pulling up the lid body 50. Then, the user can recognize that the container cap 1 is not unused from the state in which the weakened portion 15b is broken. Therefore, it is possible to provide the container cap 1 with an unopened guarantee function with a simple configuration. In addition, in this embodiment, the protruding portion 15a enters into the lid body recess 52b formed in the top wall 52 to engage the stopper body 15 and the lid body 50, so that the stopper body 15 does not protrude upward from the top wall 52 of the lid body 50. This prevents the appearance of the lid 50 from being marred.

In addition, in this embodiment, the plug 15 has a blocking portion 14f that is connected to the weakened portion 15b and blocks the spout 14a, and a standing portion 15c that stands upright from the blocking portion 14f and engages with the lid opening 52a, and the upper portion of the standing portion 15c is configured to have a protruding portion 15a that protrudes radially outward and engages with the lid opening 52a by undercut. By adopting such a configuration, the height position of the weakened portion 15b can be positioned at the bottom of the spouting tube 14 by the height of the standing portion 15c, so that the flow when the contents are poured out of the spouting tube 14 can be stabilized.

In this embodiment, the erected portion 15c includes a base portion 15c1 and a tip portion 15c2 that is connected to the upper portion of the base portion 15c1 and is formed narrower than the base portion 15c1, and the annular protrusion 52c that forms the peripheral portion of the lid body opening 52a in the top wall 52 is fitted between the protrusion 15a and the upper portion of the base portion 15c1, so that the plug 15 engages with the peripheral portion of the lid body opening 52a. By adopting such a configuration, the erected portion 15c of the plug 15 can be firmly engaged with the top wall 52 of the lid body 50, and the sealing property between the plug 15 and the lid body 50 can be improved. In addition, even after the weakened portion 15b is broken, the plug 15 is configured to be difficult to move upward or downward relative to the top wall 52 of the lid body 50, so that the sealing effect between the top wall 52 and the erected portion 15c can be maintained. In addition, when the contents are filled into the container body 2 at a high temperature, the contents are cooled using shower water or the like, but when the container cap 1 according to this embodiment is attached to the container body 2, it is possible to prevent shower water or the like from entering the cap from the outside.

In a modified version of this embodiment, the upper surface of the annular protrusion 52c that forms the periphery of the lid opening 52a is configured to have engagement irregularities 52c1-52c5, which are convex and/or concave portions for strengthening engagement with the protrusion 15a. By adopting such a configuration, the engagement irregularities 52c1-52c5 and the convex and concave portions provided on the protrusion 15a interlock with each other, making it difficult for the protrusion 15a to come off the annular protrusion 52c. In addition, the complementary shapes of the engagement irregularities 52c1-52c5 and the protrusion 15a increase the contact area, thereby increasing the adhesive strength of the protrusion 15a to the annular protrusion 52c and improving the seal between them.

In addition, in a modified example of this embodiment, the engagement unevenness portions 52c1, 52c2, and 52c5 are configured to have a generally step shape that protrudes further upward on the radially inner side. By adopting such a configuration, the contact area between the annular protrusion 52c and the erected portion 15c can be further increased, thereby increasing the adhesive strength.

In addition, in the third modified example of this embodiment, the engagement uneven portion 52c3 is configured to have an inclined portion that inclines upward toward the inside in the radial direction. By adopting such a configuration, the contact area between the annular protrusion 52c and the standing portion 15c can be further increased, thereby increasing the adhesive strength.

In addition, in the second and fifth modified examples of this embodiment, the engagement unevenness portions 52c2, 52c5 are configured so that the unevenness is repeated in the circumferential direction. By adopting such a configuration, the contact area is increased due to the complementary shapes of the engagement unevenness portions 52c2, 52c5 and the protrusion 15a, so that the adhesive strength of the protrusion 15a to the annular protrusion 52c can be increased.

In addition, this embodiment is a manufacturing method for a container cap 1 that can be attached to a container body 2 having a storage space S for contents, the container cap 1 has a spout 14a for pouring out the contents from the storage space S, and is equipped with a cap body 10 that is attached to the mouth 4 of the container body 2, an openable and closable lid body 50 that covers the spout 14a, and a stopper body 15 that is connected to the peripheral portion of the spout 14a via a weakened portion 15b and closes the spout 14a, the top wall 52 of the lid body 50 is provided with a lid body opening 52a that penetrates the top wall 52 and a lid body recess 52b that is connected to the upper part of the lid body opening 52a and is formed to be wider than the lid body opening 52a, and the stopper body 15 is formed with a protrusion 15a that protrudes radially outward, and the protrusion 15a is inserted into the lid body recess 52b, thereby engaging the stopper body 15 with the peripheral portion of the lid body opening 52a. By adopting such a configuration, in the unused container cap 1, the stopper body 15, which is connected to the pouring tube 14 via the weakened portion 15b and closes the pouring outlet 14a, is fixed to the lid body 50, and the stopper body 15 can be moved together with the lid body 50 by pinching and rotating the lid body 50 around the hinge portion 40 to easily open the pouring outlet 14a. Therefore, while the stopper body 15 ensures sealing in the unused state, it is possible to open the container cap 1 by a simple operation of pinching and pulling up the lid body 50. Then, the user can recognize that the container cap 1 is not unused from the state in which the weakened portion 15b is broken. Therefore, it is possible to provide the container cap 1 with an unopened guarantee function with a simple configuration. In particular, in this embodiment, by adopting the above manufacturing method, the lower surface of the protruding portion 15a abuts on the upper surface of the annular protrusion 52c of the top wall 52, and the side surface of the protruding portion 15a abuts on the outer circumferential end of the lid body recess 52b. With this configuration, even after the weakened portion 15b connecting the stopper 15 and the dispensing tube 14 breaks, the top wall 52 and the erected portion 15c are sealed liquid-tight on at least two sides, so that the contents can be effectively prevented from leaking out of the dispensing tube 14. Also, in this embodiment, the stopper 15 and the lid 50 are engaged by the protruding portion 15a entering the lid recess 52b formed in the top wall 52, so the stopper 15 does not protrude upward from the top wall 52 of the lid 50. Therefore, the appearance of the lid 50 is not marred.

Although the present disclosure has been described based on various drawings and examples, it should be noted that a person skilled in the art would easily be able to make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these modifications and corrections are included in the scope of the present invention. For example, the functions contained in each component can be rearranged so as not to cause logical inconsistencies, and multiple components can be combined into one or divided. It should be understood that these are also included in the scope of the present invention.

For example, in this embodiment, the lid body 50 is connected to the cap body 10 by the hinge portion 40, and the lid body 50 is configured to engage with the cap body 10 by undercut engagement, but this is not limited to the embodiment. The lid body 50 may be configured to be attached to the cap body 10 by, for example, screw engagement. In this case, it is preferable that the central axis of the spout 14a and the plug body 15 and the central axis of the engagement screw are approximately aligned.

In addition, in this embodiment, the protrusion 15a formed integrally with the upper part of the standing portion 15c is configured to engage with the periphery of the lid opening 52a in an undercut manner, but this is not limited to the embodiment. The protrusion 15a may be a separate member connected to the standing portion 15c.

1, 101, 102, 103, 104, 105 Container cap 2 Container body 4 Mouth portion 4a Annular convex portion 10 Cap body 11 Outer peripheral wall 11a Engagement protruding wall 12 Inner peripheral wall 12c1 First weakened portion 12c2 Second weakened portion 12c3 Third weakened portion 12ct Cutout portion 12f Stationary connecting portion 12g Slit groove 13 Top wall 13a Engagement protrusion 13b Engagement ring 14 Spouting tube 14a Spout outlet 14f Closure portion 15 Plug body 15a Protrusion 15b Weakened portion 15c Standing portion 15c1 Base portion 15c2 Tip portion 15e Rib 15f Closure portion 15g1 Upper wall forming material 15g2 Upper wall portion 15h Partition wall 15j Wing portion 16 Sealing wall 40 Hinge portion 50 Lid 51 Knob portion 52 Top wall 52a Lid opening 52b Lid recess 52c Annular protrusion 52c1, 52c2, 52c3, 52c4, 52c5 Engaging uneven portion 52p1, 52p3 Inner protrusion 52p2, 52p4 Outer protrusion 53 Lid peripheral wall 54 Inner tube 57 Lid projection 60 Sealing member 70 Plug engagement jig 71 Upper jig 73 Lower jig O1 Central axis S Storage space

Claims (6)

A container cap that can be attached to a container body having a storage space for contents,
a cap body having a pouring outlet for pouring the contents from the storage space and attached to the mouth of the container body;
An openable and closable lid for covering the spout;
a plug body that is connected to the radially inner side of the spout through a weakened portion and closes the spout,
A top wall of the lid body is provided with a lid body opening penetrating the top wall and a lid body recess formed to be connected to an upper portion of the lid body opening and wider than the lid body opening,
a protrusion protruding radially outward from the plug fits into the lid recess, so that the plug engages with a peripheral edge of the lid opening,
A cap for a container, characterized in that an engaging uneven portion, which is a convex portion and/or a concave portion, is formed on the upper surface of an annular protrusion that forms the peripheral portion of the lid opening, to strengthen engagement with the protrusion. The plug has a blocking portion connected to the weakened portion and blocking the spout, and a standing portion standing upward from the blocking portion and engaging with the lid opening,
The container cap according to claim 1 , wherein the protruding portion is provided at an upper portion of the standing portion, the protruding portion protruding radially outward and engaging with the lid opening through an undercut. The container cap according to claim 2, wherein the erected portion includes a base portion and a tip portion that is connected to the upper portion of the base portion and is formed narrower than the base portion, and the stopper engages with the peripheral portion of the lid opening by fitting an annular protrusion that forms the peripheral portion of the lid opening in the top wall between the protrusion and the upper portion of the base portion. The container cap according to claim 1, wherein the engagement uneven portion has a generally step shape that protrudes upward on the radially inner side. The container cap according to claim 1, wherein the engagement uneven portion has an inclined portion that inclines upward toward the inside in the radial direction. The container cap according to claim 1, wherein the engagement uneven portion has repeated unevenness in the circumferential direction.

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