Cap, and unit with cap

Abstract

A cap (1) is provided with a main body (30) that is fitted into an opening part (21). The main body (30) has an annular part (34) and a plurality of protruding parts (36) provided on an outer peripheral surface (34b) of the annular part (34). In at least a part of the process in which the main body (30) is fitted into the opening part (21), a first protruding part (36A) is in contact with an opening inner peripheral surface (21a), and a second protruding part (36B) is not in contact with the opening inner peripheral surface (21a).

Description

Cap and capped unit

[0001] The present invention relates to a cap that is to be removably attached to an opening of an attachment target, and a capped unit that uses the cap.

[0002] Charging connectors have been proposed for supplying power from outside the vehicle (charging) a battery mounted on a vehicle such as an electric vehicle or a plug-in hybrid vehicle. This type of connector is generally also called a charging inlet (see, for example, Patent Document 1).

[0003] Japanese Patent Application Publication No. 2018-026288

[0004] The conventional charging inlet described above has an opening where terminals are provided and a hinged lid for exposing or sealing the opening as needed. From the perspective of simplifying the charging inlet, it has been considered to replace the hinged lid with a cap that can be attached and detached to the opening. Here, when fitting the cap into the opening, if the contact area between the cap and the opening (e.g., the number of contact ribs provided on the cap) is increased, the cap can be firmly fixed to the opening, but the task of fitting the cap into the opening becomes difficult. Conversely, if the contact area between the cap and the opening is reduced, the task of fitting the cap into the opening becomes easier, but it becomes difficult to retain the cap in the opening. For these reasons, there is a need for a cap that can easily fit into the opening of a charging inlet while retaining its original functions (e.g., dustproofness, waterproofness, etc.) and properly retaining the cap in the opening. Furthermore, as will be understood from this description, regardless of whether it is a charging inlet, it is desirable for the cap to have both its original function as a cap, the ease of fitting it into the opening of any attachment target, and the ability to be properly held in the opening.

[0005] One of the objects of the present invention is to provide a cap that has the original function of a cap while being easy to fit into the opening of the object to be attached and being properly held in the opening, and a capped unit using such a cap.

[0006] In one aspect of the present invention, the cap is a cap that is to be removably attached to an opening of an attachment object, and comprises a main body portion that is to be fitted into the opening, the main body portion having an annular portion that faces the inner peripheral surface of the opening, and a plurality of protrusions provided on the outer peripheral surface of the annular portion, the plurality of protrusions including a first protrusion portion having a predetermined shape and a second protrusion portion that has a shape different from the first protrusion portion, and is configured so that during at least a portion of the process of fitting the main body portion into the opening, the first protrusion portion contacts the inner peripheral surface of the opening and the second protrusion portion does not contact the inner peripheral surface of the opening.

[0007] In another aspect of the present invention, a capped unit includes: the cap described above; and an attachment object having an opening to which the cap is attached.

[0008] FIG. 1 is a perspective view showing a state in which a connector and a cap constituting a capped connector according to an embodiment of the present invention are separated. FIG. 2 is a perspective view showing the cap shown in FIG. 1. FIG. 3 is a perspective view of the cap shown in FIG. 1, seen from the rear. FIG. 4 is a rear view of the cap shown in FIG. 1. FIG. 5A is a perspective view showing the periphery of the first protrusion and the second protrusion of the cap shown in FIG. 4, showing the periphery of the first protrusion shown in part A of FIG. 4. FIG. 5B is a perspective view showing the periphery of the first protrusion and the second protrusion of the cap shown in FIG. 4, showing the periphery of the second protrusion shown in part B of FIG. 4. FIG. 6 is a view corresponding to FIG. 4, showing the contact / non-contact state between the first protrusion and the second protrusion of the cap and the inner circumferential surface of the opening of the fitting recess when the cap is completely attached to the fitting recess of the housing. FIG. 7 is a view corresponding to FIG. 6, showing a case in which the cap is misaligned within the fitting recess during the process of fitting the cap into the fitting recess of the housing. FIG. 8A is a view corresponding to FIG. 5A, showing a first protrusion according to a modified example. Fig. 8B is a view corresponding to Fig. 5B showing a second protrusion according to a modified example. Fig. 9 is a view corresponding to Fig. 6 when the modified example shown in Figs. 8A and 8B is adopted. Fig. 10A is a side view showing the process of fitting a cap into a fitting recess of a housing when the modified example shown in Figs. 8A and 8B is adopted, showing the stage at which the first protrusion begins to contact the inner circumferential surface of the opening of the fitting recess. Fig. 10B is a side view showing the process of fitting a cap into a fitting recess of a housing when the modified example shown in Figs. 8A and 8B is adopted, showing the stage at which the second protrusion begins to contact the inner circumferential surface of the opening of the fitting recess after the stage shown in Fig. 10A.

[0009] A capped connector 3 according to an embodiment of the present invention, including a cap 1 according to an embodiment of the present invention, will be described below with reference to the drawings. As shown in FIG. 1 , the capped connector 3 is composed of the cap 1 and a connector 2 to which the cap 1 is attached. The connector 2 is installed in a vehicle such as a plug-in hybrid vehicle or an electric vehicle, and is connected to an electric wire extending from a battery mounted on the vehicle. The connector 2 is also called a charging inlet. By mating a mating connector (a so-called charging gun) with the mating recess 21 of the connector 2 (see FIG. 1 ), power is supplied to the battery from outside the vehicle, thereby charging the battery.

[0010] For the sake of convenience, the following definitions are used for the terms "front," "rear," "left," "right," "upper," and "lower," as shown in FIG. 1 and elsewhere. The "front-rear direction," "left-right direction," and "upper-lower direction" are perpendicular to one another. The front-rear direction coincides with the mating direction of the connector 2 and the mating connector (not shown). The front side of the mating direction (the side approaching the mating connector) from the perspective of the connector 2 is referred to as the "front side," and the release side of the mating direction (the side moving away from the mating connector) from the perspective of the connector 2 is referred to as the "rear side." Note that the "front-rear direction," "left-right direction," and "upper-lower direction" are defined merely for the sake of convenience, and do not necessarily correspond to the front-rear direction, left-right direction, and upper-lower direction of the vehicle when the connector 2 is mounted on the vehicle.

[0011] As shown in Fig. 1, the connector 2 to which the cap 1 is attached includes a pair of left and right terminals 10 and a housing 20 that accommodates the pair of left and right terminals 10. One ends of a pair of left and right electric wires 4 are connected to the pair of left and right metal terminals (female terminals) 10, respectively. The other ends of the pair of left and right electric wires 4 are connected to, for example, a battery (not shown). In this example, the housing 20 is formed by combining multiple resin parts, etc., but it may also be formed from a single resin part.

[0012] A mating recess 21 that opens forward and is recessed rearward is defined at the front end of the housing 20. In this example, the mating recess 21 is a recess that has a circular shape when viewed from the front. The housing 20 is provided with a pair of cylindrical terminal accommodating portions 22 that protrude forward within the mating recess 21 and correspond to the pair of left and right terminals 10. Each terminal accommodating portion 22 has an internal space that penetrates in the front-to-rear direction. The pair of left and right terminals 10 are accommodated in the pair of left and right terminal accommodating portions 22 of the housing 20, respectively. By mating a mating connector with the mating recess 21 of the housing 20, a pair of left and right male terminals (not shown) belonging to the mating connector are connected to the pair of left and right terminals 10, respectively, and power is supplied to the battery from outside the vehicle.

[0013] The cap 1 is a part that is removably fitted into the mating recess 21 of the housing 20, and by being fitted into the mating recess 21 and covering the opening of the mating recess 21, it serves the functions of protecting the pair of left and right terminals 10 located within the mating recess 21, as well as preventing dust from entering the mating recess 21.

[0014] The cap 1 is typically made of elastomer (or rubber) and is an elastically deformable molded body. As shown in Figures 2 to 4, the cap 1 is composed of a main body 30 that fits into the fitting recess 21 to cover the opening of the fitting recess 21, and an operating part 40 that protrudes forward from the main body 30 and extends outward from the fitting recess 21.

[0015] 2 to 4 , the main body 30 includes a flat, disc-shaped central wall 31 extending in a direction perpendicular to the front-to-rear direction, a tapered wall 32 extending obliquely from the entire circumference of the outer periphery of the central wall 31 toward the front and radially outward, an annular flange 33 extending radially outward from the entire circumference of the outer periphery of the tapered wall 32, and a substantially cylindrical annular portion 34 extending rearward from the entire circumference of the outer periphery of the tapered wall 32. When the cap 1 is attached to the fitting recess 21, the central wall 31 and the tapered wall 32 cover the opening of the fitting recess 21, the annular flange 33 faces an end face (front end face) 21 b of the opening edge of the fitting recess 21 (see FIG. 1 ), and the annular portion 34 faces an inner circumferential surface 21 a of the opening of the fitting recess 21 (see FIG. 6 , etc.).

[0016] As shown in FIGS. 2 to 4 , the outer peripheral surface 34b of the annular portion 34 of the main body 30 includes a plurality of (four in this example) first protrusions 36A protruding radially outward from the annular portion 34 and arranged at equal intervals around the circumference of the annular portion 34. Furthermore, a plurality of (four in this example) second protrusions 36B protruding radially outward from the annular portion 34 are arranged at equal intervals around the centers of adjacent first protrusions 36A around the circumference of the annular portion 34. As shown in FIG. 5A , the first protrusions 36A are protruding in the front-to-rear direction. The first protrusions 36A extend from the annular flange portion 33 to a position a predetermined distance forward (forward) of the opening end 34a of the annular portion 34. As shown in FIG. 5B , the second protrusions 36B are also protruding in the front-to-rear direction. The second protrusion 36B extends from the annular flange 33 to the open end 34a of the annular portion 34. The second protrusion 36B has a lower protrusion height from the outer peripheral surface 34b and a wider width than the first protrusion 36A. Therefore, the second protrusion 36B has higher rigidity than the first protrusion 36A. As shown in Figures 5A and 5B, a tapered surface 38 is formed on the rear edge of each of the first protrusion 36A and the second protrusion 36B, which is inclined in a direction moving forward as it moves radially outward from the annular portion 34.

[0017] The diameter of an imaginary circle passing through the protruding ends of the multiple first protrusions 36A is the same as or slightly larger than the diameter of the circle that defines the opening inner circumferential surface 21a of the fitting recess 21 of the housing 20. Therefore, when the cap 1 is fully attached to the fitting recess 21 (hereinafter referred to as the "cap attachment complete state"), each first protrusion 36A contacts the opening inner circumferential surface 21a (see FIG. 6). On the other hand, the diameter of an imaginary circle passing through the protruding ends of the multiple second protrusions 36B is slightly smaller than the diameter of the circle that defines the opening inner circumferential surface 21a of the fitting recess 21 of the housing 20. Therefore, when the cap is fully attached, each second protrusion 36B does not contact the opening inner circumferential surface 21a (see FIG. 6). During the process of fitting the cap 1 into the fitting recess 21 (hereinafter referred to as the "cap attachment process"), the tapered surface 38 of each first protrusion 36A functions to guide the end face 21b (see Figure 1) of the opening edge of the fitting recess 21 so that it moves toward the protruding end face of the first protrusion 36A, and the tapered surface 38 of each second protrusion 36B functions to guide the end face 21b (see Figure 1) of the opening edge of the fitting recess 21 so that it moves toward the protruding end face of the second protrusion 36B.

[0018] 2 to 4, the outer peripheral surface 34b of the annular portion 34 of the main body 30 is further provided with a plurality of (two in this example) positioning protrusions 37 that protrude radially outward from the annular portion 34 and are spaced apart in positions in the circumferential direction of the annular portion 34 where the first protrusion 36A and the second protrusion 36B are not provided. When the cap is fully attached, the plurality of positioning protrusions 37 are inserted into and accommodated in a plurality of (two in this example) positioning recesses 23 (see FIG. 6) formed in the opening inner peripheral surface 21a of the fitting recess 21 in correspondence with the plurality of positioning protrusions 37. This determines the circumferential position of the cap 1 relative to the housing 20 (connector 2).

[0019] The operating portion 40 is a portion that is operated (external force is applied) by a user's finger or the like when attaching or detaching the cap 1 to or from the fitting recess 21 of the housing 20. As shown in FIG. 2 , the operating portion 40 has a cylindrical portion 41 that protrudes forward from the front surface of the central wall portion 31 of the main body portion 30. The cylindrical portion 41 has a cylindrical shape that is elongated in the left-right direction when viewed from the front. The opening at the protruding end (front end) of the cylindrical portion 41 is closed by a flat plate-shaped connecting portion 43 that extends in the up-down direction, while the rear end of the cylindrical portion 41 opens in the central wall portion 31. The cylindrical portion 41 includes a pair of upper and lower plate-shaped portions 44 that are approximately rectangular flat plates and extend in the front-to-rear direction. The pair of upper and lower plate-shaped portions 44 are portions that are actually operated (external force is applied) by a user's finger or the like when attaching or detaching the cap 1 to or from the fitting recess 21 of the housing 20.

[0020] When fitting the cap 1 into the fitting recess 21 of the housing 20, the user pinches the pair of upper and lower plate-like portions 44 of the operating portion 40 of the cap 1 with their fingers, and in this state, pushes the cap 1 into the fitting recess 21 (applying a rearward external force to the operating portion 40) so that the annular portion 34 of the main body 30 is inserted into the fitting recess 21 until the annular flange portion 33 of the main body 30 abuts against the end face (front end face) 21b of the opening edge of the fitting recess 21. This allows the cap 1 to be fitted into the fitting recess 21.

[0021] 6, as described above, each of the first protrusions 36A contacts the opening inner peripheral surface 21a, while each of the second protrusions 36B does not contact the opening inner peripheral surface 21a. This makes it easier to fit the cap 1 into the fitting recess 21 compared to, for example, a case where both the first protrusions 36A and the second protrusions 36B are constantly in contact with the opening inner peripheral surface 21a throughout the entire cap attachment process.

[0022] 7, if the cap 1 is displaced within the fitting recess 21 as indicated by the white arrow during the cap attachment process (for example, if the worker attaches the cap 1 at an angle to the fitting recess 21), both the first protrusion 36A and the second protrusion 36B, which has a lower protrusion height than the first protrusion 36A, come into contact with the opening inner circumferential surface 21a, thereby preventing excessive displacement of the cap 1. This improves the ease of fitting the cap 1 into the fitting recess 21.

[0023] On the other hand, when the cap is fully attached, the user can pinch the pair of upper and lower plate-shaped portions 44 of the cap 1 with their fingers, and in that state, apply a forward external force to the operating portion 40 to remove (separate) the cap 1 from the fitting recess 21.

[0024] As described above, with the cap 1 and capped connector 3 according to this embodiment, the main body 30 of the cap 1 is fitted into the fitting recess 21 of the connector 2, thereby sealing the fitting recess 21. This allows the cap 1 to perform its intended functions (e.g., dustproofness, waterproofness, etc.). Furthermore, multiple types of protrusions 36 (i.e., first protrusions 36A and second protrusions 36B) with different shapes are provided on the outer peripheral surface 34b of the annular portion 34 of the main body 30. During at least a portion of the process of fitting the main body 30 into the fitting recess 21 (the cap attachment process), the first protrusions 36A contact the opening inner peripheral surface 21a, but the second protrusions 36B do not contact the opening inner peripheral surface 21a. This makes it easier to fit the cap 1 into the fitting recess 21 compared to, for example, a case where both the first protrusion 36A and the second protrusion 36B are constantly in contact with the opening inner circumferential surface 21a throughout the entire cap attachment process. Therefore, the cap 1 and capped connector 3 according to this embodiment can achieve both ease of fitting into the fitting recess 21 of the connector 2 and proper retention in the fitting recess 21 while retaining the original function of the cap 1.

[0025] Furthermore, with the cap according to this embodiment, the first protrusion 36A, which has a high protrusion height, contacts the opening inner peripheral surface 21a of the fitting recess 21, thereby properly fixing the cap 1 to the fitting recess 21. However, if the cap 1 is misaligned within the fitting recess 21 during the cap installation process (for example, if the worker installs the cap 1 at an angle relative to the fitting recess 21), both the first protrusion 36A and the second protrusion 36B, which has a low protrusion height, contact the opening inner peripheral surface 21a, thereby preventing excessive misalignment. This improves the ease of fitting the cap 1 into the fitting recess 21 of the connector 2.

[0026] Furthermore, with the cap 1 according to this embodiment, when the cap 1 is fitted into the fitting recess 21, the user can apply an external force to the operating portion 40 protruding from the main body portion 30 of the cap 1 to separate the cap 1 from the fitting recess 21 (for example, by the user pinching the operating portion 40 with their fingers and pulling it out in the protruding direction).

[0027] It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be adopted within the scope of the present invention. For example, the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. are possible as appropriate. Furthermore, the material, shape, dimensions, number, location, etc. of each component in the above-described embodiments are arbitrary as long as they can achieve the present invention, and are not limited thereto.

[0028] In the above embodiment, the second protrusion 36B protrudes less from the outer peripheral surface 34b of the annular portion 34 of the cap 1 than the first protrusion 36A, so that, during at least a portion of the cap attachment process, the first protrusion 36A contacts the opening inner peripheral surface 21a but the second protrusion 36B does not contact the opening inner peripheral surface 21a. In contrast, as shown in Figures 8A and 8B, the first protrusion 36A and the second protrusion 36B may protrude the same height from the outer peripheral surface 34b, but the length of the second protrusion 36B in the front-to-rear direction may be shorter than the length of the first protrusion 36A, so that, during at least a portion of the cap attachment process, the first protrusion 36A contacts the opening inner peripheral surface 21a but the second protrusion 36B does not contact the opening inner peripheral surface 21a.

[0029] In the modified example shown in Figures 8A and 8B, the first protrusion 36A extends from the annular flange 33 to the opening end 34a of the annular portion 34, as shown in Figure 8A. Meanwhile, the second protrusion 36B extends from the annular flange 33 to a position a predetermined distance forward of the opening end 34a of the annular portion 34, as shown in Figure 8B. The diameter of an imaginary circle passing through the protruding ends of the first protrusion 36A and the second protrusion 36B is equal to or slightly larger than the diameter of the circle that defines the opening inner circumferential surface 21a of the fitting recess 21 of the housing 20. Therefore, when the cap is fully attached, both the first protrusion 36A and the second protrusion 36B contact the opening inner circumferential surface 21a (see Figure 9). This allows the cap 1 to be properly secured to the fitting recess 21. Furthermore, during the cap attachment process, the state where only the long first protrusion 36A contacts the opening inner circumferential surface 21a of the fitting recess 21 (see FIG. 10A) passes, and then the state where both the first protrusion 36A and the short second protrusion 36B contact the opening inner circumferential surface 21a (see FIG. 10B) is reached. This gradually increases the external force required to fit the cap 1 into the connector 2, thereby improving the workability of fitting the cap 1 into the fitting recess 21 of the connector 2.

[0030] Here, in the above-described embodiment of the present invention, the cap (1) is a cap (1) to be detachably attached to an opening (21) of an attachment object (2), and includes a main body portion (30) to be fitted into the opening (21), the main body portion (30) having an annular portion (34) to face an inner peripheral surface (21a) of the opening (21) and a plurality of protrusions (36) provided on an outer peripheral surface (34b) of the annular portion (34), and the plurality of protrusions (36) are The body portion (30) includes a first protrusion (36A) having a predetermined shape and a second protrusion (36B) having a shape different from that of the first protrusion (36A), and is configured such that, during at least a portion of the process of fitting the main body portion (30) into the opening (21), the first protrusion (36A) contacts the opening inner surface (21a) and the second protrusion (36B) does not contact the opening inner surface (21a).

[0031] According to the cap having the above configuration, the main body of the cap is fitted into the opening to seal the opening. This allows the cap to fulfill its intended functions (e.g., dustproofness, waterproofness, etc.). Furthermore, the outer peripheral surface of the annular portion of the main body is provided with multiple types of protrusions (i.e., first protrusions and second protrusions) with different shapes. During at least a portion of the process of fitting the main body into the opening (hereinafter referred to as the "cap fitting process" for convenience), the first protrusions contact the inner peripheral surface of the opening, but the second protrusions do not. This makes it easier to fit the cap into the opening compared to, for example, a case in which both the first protrusions and the second protrusions are constantly in contact with the inner peripheral surface of the opening throughout the entire cap fitting process. Furthermore, for example, if both the first protrusions and the second protrusions are in contact with the inner peripheral surface of the opening at the end of the cap fitting process, the cap can be properly held in the opening. Alternatively, for example, one of the first protruding portion and the second protruding portion may function to hold the cap in the opening, and the other may function to prevent the cap from shifting position during the cap attachment process, thereby facilitating the task of fitting the cap into the opening and enabling the cap to be properly held in the opening. Thus, the cap of this configuration can achieve both ease of fitting into the opening to which it is to be attached and proper holding in the opening, while retaining its original function as a cap.

[0032] Furthermore, the first protrusion (36A) may have a shape that protrudes from the outer peripheral surface (34b) of the annular portion (34) by a predetermined height, and the second protrusion (36B) may have a shape that protrudes from the outer peripheral surface (34b) of the annular portion (34) by a height that is lower than the predetermined height.

[0033] With the cap configured as described above, the first protruding portion, which has a higher protruding height, contacts the inner circumferential surface of the opening, thereby properly holding the cap in the opening. Furthermore, if the cap becomes misaligned within the opening during the cap installation process (for example, if the worker installs the cap at an angle relative to the opening), both the first protruding portion and the second protruding portion, which has a lower protruding height, contact the inner circumferential surface of the opening to resist the misalignment, thereby preventing excessive misalignment. This improves the ease of fitting the cap into the opening to which it is to be installed.

[0034] Furthermore, the first protrusion (36A) may have a shape that extends a predetermined length in the direction in which the main body (30) is fitted into the opening (21), and the second protrusion (36B) may have a shape that extends a length that is shorter than the predetermined length in the same direction.

[0035] According to the cap having the above configuration, the first protrusion and the second protrusion can be arranged so that, during the cap attachment process, first, only the longer first protrusion comes into contact with the inner circumferential surface of the opening, and then both the first protrusion and the second protrusion come into contact with the inner circumferential surface of the opening. This allows the external force required to fit the cap into the attachment target to gradually increase, thereby improving the workability of fitting the cap into the opening of the attachment target compared to when the external force increases suddenly.

[0036] Furthermore, the device may further include an operating portion (40) that protrudes from the main body portion (30) and extends outward from the opening portion (21).

[0037] With the cap of the above configuration, when the cap is fitted into the opening, the user can apply an external force to the operating part that protrudes from the main body of the cap to separate the cap from the opening (for example, the user can pinch the operating part with their fingers and pull it out in the protruding direction).

[0038] In the above-described embodiment of the present invention, the capped unit (3) comprises the above-described cap (1) and an attachment object (2) having an opening (21) to which the cap (1) is attached.

[0039] According to the capped unit having the above configuration, the cap's main body is fitted into the opening to seal the opening. This allows the cap's original functions (e.g., dustproofness, waterproofness, etc.) to be fulfilled. Furthermore, the outer peripheral surface of the annular portion of the main body is provided with multiple types of protrusions (i.e., first protrusions and second protrusions) with different shapes. During at least a portion of the process of fitting the main body into the opening (hereinafter referred to as the "cap fitting process" for convenience), the first protrusions contact the inner peripheral surface of the opening, but the second protrusions do not. This makes it easier to fit the cap into the opening compared to, for example, a case in which both the first protrusions and the second protrusions are constantly in contact with the inner peripheral surface of the opening throughout the entire cap fitting process. Furthermore, for example, if both the first protrusions and the second protrusions are in contact with the inner peripheral surface of the opening at the end of the cap fitting process, the cap can be properly held in the opening. Alternatively, for example, one of the first protruding portion and the second protruding portion may function to hold the cap in the opening, and the other may function to prevent the cap from shifting position during the cap attachment process, thereby facilitating the task of fitting the cap into the opening and enabling the cap to be properly held in the opening. Thus, the capped unit of this configuration can achieve both the ease of fitting the cap into the opening to be attached and the proper holding of the cap in the opening while retaining its original function as a cap.

[0040] This application is based on a Japanese patent application (Patent Application No. 2024-104152) filed on June 27, 2024, the contents of which are incorporated herein by reference.

[0041] The cap of the present invention has the inherent function of a cap, while being easy to fit into the opening of the object to be attached and being able to be properly held in the opening. The capped unit of the present invention uses this cap. The present invention, which has this effect, can be used, for example, in a charging inlet for an automobile.

[0042] REFERENCE SIGNS LIST 1 Cap 2 Connector (attachment object) 3 Capped connector (capped unit) 21 Fitting recess (opening) 21a Opening inner peripheral surface 30 Main body 34 Annular portion 34b Outer peripheral surface 36 Protrusion 36A First protrusion 36B Second protrusion 40 Operation portion

Claims

1. A cap to be removably attached to an opening of an object to be attached to, comprising: a main body portion to be fitted into said opening, said main body portion having an annular portion that faces the inner peripheral surface of said opening, and a plurality of protrusions provided on the outer peripheral surface of said annular portion, said plurality of protrusions including a first protrusion portion having a predetermined shape and a second protrusion portion having a shape different from said first protrusion portion, said cap being configured so that during at least a portion of the process of fitting said main body portion into said opening, said first protrusion portion comes into contact with said inner peripheral surface of said opening, and said second protrusion portion does not come into contact with said inner peripheral surface of said opening.

2. A cap as described in claim 1, wherein the first protrusion has a shape that protrudes a predetermined height from the outer peripheral surface of the annular portion, and the second protrusion has a shape that protrudes a height that is lower than the predetermined height from the outer peripheral surface of the annular portion.

3. A cap as described in claim 1, wherein the first protrusion has a shape that extends a predetermined length in the direction in which the main body is fitted into the opening, and the second protrusion has a shape that extends in the same direction a length that is shorter than the predetermined length.

4. A cap according to claim 1, further comprising an operating portion that protrudes from said main body portion and extends outward from said opening.

5. A capped unit comprising: a cap according to any one of claims 1 to 4; and an attachment object having an opening to which the cap can be attached.

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