DESCRIPTION MEASURING CAP AND LIQUID CONTAINER TECHNICAL FIELD [0001] The present invention relates to a measuring cap which is detachably attached, as a lid, to a container body for containing liquid such as liquid detergent, liquid softener, or bleach and which is used to measure-the liquid in the container body or to apply the liquid little by little for use. The present invention also relates to a liquid container. BACKGROUND ART [0002] There is known a measuring cap which is attached as a lid to a container body for containing liquid such as liquid detergent, liquid softener, or bleach and which is used to measure the liquid in the container body, to receive an appropriate amount of liquid from the container body and apply the liquid little by little for use, or to do the like. The use method of this measuring cap is, first, pouring liquid from the container body into the measuring cap, and then transferring the liquid from the measuring cap into, for example, a washing tub, or applying the liquid in the measuring cap to a stained portion or the like in the laundry. In order to facilitate liquid measurement and to transfer the measured liquid in the cap little by little, some measuring caps as above have a double structure including a measuring cap inner cylinder part and outer cylinder part, in which a lower end of a cylinder wall of the inner cylinder part is provided with a flange piece with 1 an outward collar shape, or in which the inner cylinder part and the outer cylinder part are adjusted in height (see, for example, Patent Literatures 1 and 2). [0003] Moreover, there is a measuring cap in which, to facilitate measurement and transfer, a measuring part has a bottom portion formed into a polygon, and has an inlet/outlet portion (on the opening side) whose inner surface is formed into a polygon (see, for example, Patent Literature 3). CITATION LIST PATENT LITERATURE [0004] Patent Literature 1: Japanese Unexamined Patent Application Publication No. Hei 8-48348 Patent Literature 2: Japanese Unexamined Patent Application Publication No. 2001-171704 Patent Literature 3: Japanese Unexamined Patent Application Publication No. 2000-62817 SUMMARY OF INVENTION [0005] In the measuring caps of Patent Literatures 1 and 2, however, the inner cylinder part from which the liquid is poured is formed into a cylindrical shape. Accordingly, when the liquid is dropped or applied onto a stained portion or the like in the laundry, a large amount of liquid flows out beyond the stained portion or the like in the laundry as well, making it difficult to pour an appropriate amount of liquid onto only the stained portion or the like in the laundry. Meanwhile, in the measuring cap of Patent Literature 3, the hexagonal shape of 2 the inner surface of the inner cylinder part makes the volume of the cap small. Accordingly, measuring a large amount of liquid requires a bigger cap or multiple measurements. In addition, the inlet/outlet portion has the inner surface with the hexagonal shape with angular peak portions, but has the outer surface with a circular shape, which makes it difficult to pour liquid little by little onto a target position such as a stained portion in the laundry. [0006] The present invention aims to provide a measuring cap and a liquid container which allow easy and accurate liquid pouring onto only a stained portion or the like in the laundry even when the liquid has a high viscosity. [0007] A first aspect of the present invention provides a measuring cap including: an outer cylinder part threadably attached to an opening portion of a container body; a bottomed-cylindrical inner cylinder part located inside the outer cylinder part; a ring-shaped wall covering a gap between an edge portion of the outer cylinder part and a cylindrical wall of the inner cylinder part; and a ring-shaped sealing portion formed on an inner surface of the ring-shaped wall in a projecting manner, wherein the inner cylinder has a pour portion formed in a part of the cylindrical wall and bent into a V shape in cross section, and wherein an upper part and a lower part of the cylindrical wall of the inner cylinder part, divided by the ring-shaped wall, are formed to have substantially the same shape. [0008] According to the first aspect described above, since a part of the inner cylinder part is provided with the pour portion 3 with the substantial V shape in cross section, a user can pour the liquid from the inner cylinder part of the measuring cap little by little, and also can pour the liquid in the measuring cap onto only a stained portion or the like in the laundry, allowing easy and accurate application of an appropriate amount of liquid onto the stained portion or the like in the laundry. Further, visibility of a measurement scale is improved by forming the pour portion with the substantial V shape in cross section with two faces which are flat in an axial direction. [0009] An angle of the pour portion with the V shape in cross section may be in a range of 50 to 1500. [0010] The cylindrical wall of the inner cylinder part may have a cylindrical portion with an arc shape in cross section at a part other than the pour portion with the V shape in cross section. [0011] The pour portion with the V shape in cross section may have two flat faces joined to each other, and end portions of the two flat faces and end portions of the cylindrical portion may be joined to each other, respectively. [0012] According to the above configuration, since the end portions of the continuously-formed two flat face portions, which are located opposite from the pour portion, are joined to the end portions of the cylindrical portion with a substantial arc shape in cross section, the liquid easily gathers toward the V-shaped peak portion of the pour portion. [0013] 4 A second aspect of the present invention, provides a liquid container including: a container body for containing liquid; and the measuring cap according to the present invention as described in the preceding paragraphs, the measuring cap being detachably attached to an opening portion of the container body. BRIEF DESCRIPTION OF DRAWINGS [0014] [Fig. 1] Fig. 1 is a perspective view of a measuring cap according to a first embodiment of the present invention. [Fig. 2] Fig. 2 is a perspective view showing the measuring cap in Fig. 1 from a pour portion side. [Fig. 3] Fig. 3 is a cross-sectional view taken along a III-III line in Fig. 2. [Fig. 4] Fig. 4 is a view schematically illustrating an inner cylinder part including the pour portion of the measuring cap in Fig. 1. [Fig. 5] Fig. 5 is a perspective view of a liquid container to which the measuring cap in Fig. 1 is being attached. [Fig. 6] Fig. 6 is a perspective view of a container body of the liquid container with the measuring cap in Fig. 1 being detached. [Fig. 7] Fig. 7 is a cross-sectional view taken along a VII-VII line in Fig. 5. [Fig. 8] Fig. 8 is a cross-sectional view showing a modified example in which a cap is attached to a container body via an internal tap. [Fig. 9] Fig. 9(a) is a diagram illustrating how the measuring cap according to the first embodiment of the present invention is inclined, for performance measurement, to pour 5 liquid from the pour portion with a substantial V shape, and Fig. 9(b) is a diagram illustrating how a measuring cap of a comparative example is inclined, for performance measurement, to pour liquid from its circular pour portion. [Fig. 10] Fig. 10 is a diagram illustrating the comparison between performance evaluations of the above measuring caps. [Fig. 11] Fig. 11(a) is a perspective view of a cap according to a second embodiment of the present invention, Fig. 11 (b) is a perspective view showing the cap from a pour portion side, and Fig. 11(c) is a cross-sectional view taken along a XIc-XIc line in Fig. 11(b). [Fig. 12] Fig. 12 is a view schematically illustrating an inner cylinder part including a pour portion of a measuring cap according to a third embodiment of the present invention. DESCRIPTION OF EMBODIMENTS [00151 Embodiments of the present invention will be described in detail below based on the drawings. [0016] [First Embodiment] Fig. 1 is a perspective view showing a measuring cap according to a first embodiment of the present invention. Fig. 2 is a perspective view showing the measuring cap from a pour portion side. Fig. 3 is a cross-sectional view taken along a III-III line in Fig. 2. Fig. 4 is a view illustrating an inner cylinder part including the pour portion of the cap. Fig. 5 is a perspective view of a liquid container to which the cap is being attached. Fig. 6 is a perspective view of a container body of the liquid container with the cap being detached. Fig. 6 7 is a cross-sectional view taken along a VII-VII line in Fig. 5. Fig. 8 is a cross-sectional view showing a modified example in which a measuring cap is attached to a container body via an internal tap. [0017] As shown in Figs. 1 to 3, 5, and 7, a measuring cap 1 includes: an outer cylinder part 2 which is threadably attached to an opening portion 21 of a container body 20 of a liquid container 100 containing liquid A; an inner cylinder part 3 shaped as a cylinder with a bottom and formed inside the outer cylinder part 2 integrally as a two-cylinder structure; a ring-shaped wall 5 which covers a gap between an edge portion of the outer cylinder part 2 and a cylindrical wall 4 of the inner cylinder part 3; and a ring-shaped sealing portion 6 formed integrally in an inner surface of the ring-shaped wall 5 in a projecting manner. The ring-shaped sealing portion 6 has a contact 7 being a ring-shaped rib and an inner ring 8 being a ring wall projecting inside, and higher than, the contact 7. [00181 As Figs. 6 and 7 show, an internal tap 30 is attached to the opening portion 21 of the container body 20 of the liquid container 100. Each portion is arranged so that the inside of the container body 20 is sealed when the outer cylinder part 2 of the measuring cap 1 is threadably attached to the opening portion 21 of the container body 20. Specifically, the threadable attachment presses the contact 7 described above against an edge portion 31a of a circumferential wall 31 of the internal tap 30, and brings a wall surface of the inner ring 8 into contact with the circumferential wall 31 of the internal tap 30. 7 [0019] In the liquid container 100 of the present embodiment, the internal tap 30 does not necessarily have to be provided to the opening portion 21 of the container body 20. However, considering facilitation of liquid pouring from the container body 20 to the measuring cap 1 and prevention of dripping accompanying the liquid pouring, it is preferable that, like the container body 20 shown in Fig. 6, the container body 20 be provided with the internal tap 30 including a beak-shaped pour portion 32 and, at a base portion of the pour portion 32, a liquid return hole 33. Note that, like a liquid container 100A of a modified example shown in Fig. 8, the internal tap 30 may be threadably attached to the opening portion 21 of the container body 20, so that a measuring cap 1A may be threadably attached to the internal tap 30. [0020] The measuring cap 1 according to the present embodiment is a two-cylinder structure cap having the outer cylinder part 2 and the inner cylinder part 3, and is characterized by including a pour portion 9 which is integrally formed by partially bending the cylindrical wall 4 of the inner cylinder part 3 into a substantial V shape in cross section. To be more specific, in the measuring cap 1 of the present embodiment, the cylindrical wall 4 of the inner cylinder part 3 is formed into a substantial V shape in cross section by being bent partially at two flat face portions 9a, 9a which are continuous to each other. This portion serves as the pour portion 9 which is used as a liquid path when the liquid A is poured from the measuring cap 1. As Fig. 4 shows, the angle () formed between the continuous two flat face portions 9a, 9a of the pour portion 8 9 with a substantial V shape in cross section is set in the range of 500 to 1500 (or preferably, in the range of 600 to 130*, and more preferably, in the range of 90' to 1200). [00211 The continuous two flat face portions 9a, 9a of the pour portion 9 of the cylindrical wall 4 are formed symmetrically to a peak portion 9b of the V shape. Moreover, in consideration of the size of the beak-shaped pour portion 32 of the container body 20, the flat face portions 9a, 9a are formed to fit inside the diameter of a circumscribed circle of a cylindrical portion 10, having a substantial arc shape in cross section, of the cylindrical wall 4. [0022] The cylindrical wall 4 of the inner cylinder part 3 of the measuring cap 1 has the cylindrical portion 10 with the substantial arc shape in cross section, at a part other than the pour portion 9 with the substantial V shape in cross section. This cylindrical portion 10 with the substantial arc shape in cross section is joined, at its both end portions, to end portions of the continuously-formed two flat face portions 9a, 9a, respectively, the end portions of the flat face portions 9a, 9a being the ends opposite from the pour portion 9. The substantial arc shape, in cross section, of the cylindrical portion 10 facilitates gathering of the liquid A to the V-shaped peak portion 9b of the pour portion 9 when the pour portion 9 is inclined, thereby improving the pourability. Further, enough volume can be provided without enlarging the inner cylindrical portion more than necessary. [0023] As shown in Fig. 1, an upper part and a lower part of the 9 cylindrical wall 4 of the inner cylinder part 3, divided by the ring-shaped wall 5, have substantially the same shape. More specifically, parts of the inner cylindrical portion 4 on an opening end 3a side and on a base portion 3b side of the inner cylinder part 3, divided by the ring-shaped wall 5, each protrude from the outer cylinder part 2 in an axis direction thereof. The outer shape and the inner shape of the cylindrical wall 4 of the inner cylinder part 3 on the opening end 3a side are formed to have substantially the same shapes as the outer shape and the inner shape of the cylindrical wall 4 of the inner cylinder part 3 on the base portion 3b side. The cylindrical wall 4 of the inner cylinder part 3 can be formed to have a substantially uniform thickness over the entire circumference. [0024] For smooth separation of the liquid from the cap, the opening end 3a of the inner cylinder part 3 may partially extend outward in a round shape (in a curved shape) either only at the pour portion 9 with the substantial V shape in cross section, i.e., the continuous two flat face portions 9a, 9a including the pour portion 9, or over the entire circumference of the pour portion 9 and the cylindrical portion 10. [0025] The diameter of the outer cylinder part 2 is set to a value which allows a user to hold the cap easily. As shown in Figs. 1 and 2, an outer surface of a cylindrical wall of the outer cylinder part 2 may be provided with knurling as necessary to provide a grip. As Fig. 1 shows, the inner cylinder part 3 is graduated appropriately. [0026] As shown in Fig. 5, the liquid container 100 includes the 10 container body 20 for containing the liquid A and the measuring cap 1 detachably attached to the opening portion 21 of the container body 20. Examples of the liquid A include liquid detergent containing surface-active agent, liquid softener, and bleach. The measuring cap 1 of the present embodiment is effective not only for liquid having a low viscosity property, but also particularly for liquid having a stringy, high viscosity property or the like, where the liquid does not separate smoothly from the cap. For example, the liquid A preferably has a viscosity at 25'C of 50 to 2000 mPa-s (using a B-type viscometer with revolutions of 60rpm and a rotor No. 3), or preferably, 100 to 1000 mPa-s. Further, the viscosity change between 5 0 C and 25*C (Vis (5 0 C) / Vis (25 0 C) ) is preferably between 1.5 and 8, inclusive. [0027] To use the liquid container 100 of the present embodiment, first, the liquid A is poured from the container body 20 into the inner cylinder part 3 of the measuring cap 1. Next, as shown in Fig. 2, the cap 1 is inclined to pour the liquid A onto a stained portion or the like in the laundry, for example. Here, since the cylindrical wall 4 of the inner cylinder part 3 is partially provided with the pour portion 9 with the substantial V shape in cross section formed by the continuous two flat face portions 9a, 9a, the V-shaped peak portion 9b of the pour portion 9 with the substantial V shape in cross section allows pouring of a small amount, allowing easy and accurate pour and application of an appropriate amount of the liquid A onto only the stained portion or the like in the laundry. [0028] In the measuring cap 1, parts of the inner cylinder part 11 3 on the opening end 3a side and on the base portion 3b side each protrude from the outer cylinder part 2 in the axis direction thereof, and the outer shape and the inner shape of the cylindrical wall 4 of the inner cylinder part 3 on the opening end 3a side are formed to have substantially the same shapes as the outer shape and the inner shape of the cylindrical wall 4 of the inner cylinder part 3 on the base portion 3b side, respectively. Accordingly, even when the measuring cap 1 is being attached to the container body 20, a user of the measuring cap 1 can recognize the position of the pour portion 9 easily and immediately. When the liquid A is poured using the measuring cap 1, the liquid A can be accurately poured little by little from the pour portion 9 of the measuring cap 1 onto a certain part which needs application. The liquid A staying in the inner side of the cylindrical wall 4 of the inner cylinder part 3 flows from the arc-shaped portion and along the flat face portions, and then gathers in the V-shaped peak portion 9b of the pour portion 9. The liquid A can therefore be gathered more completely. At the opening end 3a side of the inner cylinder part 3, the cylindrical portion 4 has the arc-shaped portion as its outer shape; accordingly, in a case where the container body 20 is provided with the internal tap 30, the opening end 3a of the measuring cap 1 can collect, from the return hole 33, the liquid A remaining on a lowermost part of the internal tap 30. [0029] Next, performance evaluations of the measuring cap 1 of the first embodiment of the present invention and a measuring cap K of a comparative example are explained using Figs. 9 and 10. 12 [00301 <Measurement Method> With the liquid A as liquid detergent in the measuring caps 1, K, the measuring caps 1, K were inclined for one second by 200 from the horizontal state, and amounts of liquid poured were measured. [0031] <Caps used> 1. Measuring cap 1 (measurable volume: 55ml, inner diameter of measurement part: <p38mm, shape of pour portion 9: substantial V shape in cross section) 2. Measuring cap K (measurable volume: 55ml, inner diameter of measurement part: (p38mm, shape of a pour portion L: circular shape in cross section) <Liquid detergent used> 1. Liquid with low viscosity (10mPa-s) 2. Liquid with intermediate viscosity (170mPa-s) 3. Liquid with high viscosity (500mPa-s) The amount measured was 30g for all the detergents. <Measurement Results> As shown in a part indicated by Z in Fig. 10, in the case of the liquid with a high viscosity, the amount of liquid poured was 26.5% for the measuring cap 1 having the pour portion 9 with the substantial V shape in cross section, and the amount of liquid poured was 49% for the measuring cap K having a circular shape in cross section L. The evaluations show that the amount of liquid poured from the measuring cap 1 was approximately a half (approximately 1/2) of that from the measuring cap K. [0032] [Second Embodiment] 13 Fig. 11 shows a measuring cap 1B according to a second embodiment of the present invention. In the first embodiment, with the continuous two flat face portions 9a, 9a, the pour portion 9 with the substantial V shape in cross section is formed in a part of the cylindrical wall 4 of the inner cylinder part 3. In the second embodiment, in contrast, with continuous two curved portions 9a', 9a' each depressing inward, a pour portion 9' with a substantial V shape in cross section is formed in a part of the cylindrical wall 4 of the inner cylinder part 3. The second embodiment offers advantageous effects similar to those offered by the first embodiment. [0033] [Third Embodiment] Fig. 12 shows a measuring cap 1C according to a third embodiment of the present invention. In the first embodiment described earlier, with the continuous two flat face portions 9a, 9a, the pour portion 9 with the substantial V shape in cross section is formed in a part of the cylindrical wall 4 of the inner cylinder part 3. In the third embodiment, in contrast, with continuous two curved portions 9a", 9a" each bulging outward, a pour portion 9" with a substantial V shape in cross section is formed in a part of the cylindrical wall 4 of the inner cylinder part 3. The third embodiment also offers advantageous effects similar to those offered by the first embodiment. [0034] The caps 1, 1A, 1B, 1C and the container body 20 used in the liquid containers 100, 100A of the above embodiments can be industrially-fabricated easily by injection molding using a synthetic resin, for example. 14 [0035] The measuring caps 1, 1A, 1B, 1C of the above embodiments are each a measuring cap of a liquid container for containing various types of liquids such as liquid detergent containing surface-active agent, liquid softener, or bleach, and are useful as a measuring cap for measuring a certain amount of liquid with a high viscosity poured from the container body or for applying the liquid to an application target, such as the laundry, by a small amount at a time. Further, the liquid container including this measuring cap is useful as a container for various types of liquids such as liquid detergent containing surface-active agent, liquid softener, or bleach. [0035a] Comprises/comprising and grammatical variations thereof when used in this specification are to be taken to specify the presence of stated features, integers, steps or components or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. 15