JP7532239B2 - Liquid Containment Unit - Google Patents

Description

The present invention relates to a liquid storage unit.

Some liquid ejection devices, such as inkjet recording devices, are equipped with a liquid storage pack that stores liquid such as ink inside a flexible, flat bag. In order to supply liquid to the liquid ejection device at a uniform concentration even over time, such liquid storage packs often adopt a configuration in which the liquid intake port inside the bag is arranged asymmetrically up and down when placed in a case that is attached to the device body. In such a configuration, it is necessary to place the liquid storage pack in the case with the correct up and down orientation, but Patent Document 1 describes a liquid storage pack that has a handle on one surface side of the bag, making it easy to recognize whether it should be stored in the case up or down.

JP 2018-65374 A

However, in the liquid containing pack described in Patent Document 1, adding a handle not only increases the number of parts, but also leads to an increase in the size of the product.
SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a liquid containing unit that can easily contain a liquid containing pack in a case in the correct orientation without requiring any additional parts.

In order to achieve the above-mentioned object, the present invention provides a liquid containing unit comprising a rectangular parallelepiped case having an opening on one of its maximum area faces, and a liquid containing pack removably mounted in the case via the opening, the liquid containing pack comprising a flat bag for containing liquid, and a rectangular parallelepiped adapter attached to one end of the bag and provided with a liquid supply port, the adapter comprising recesses extending in the first direction on both outer sides continuous with the face provided with the supply port, but not facing the bottom face of the case, when a direction connecting the opening of the case and a bottom face facing the opening is defined as a first direction, the adapter comprises recesses provided in the first direction on both outer sides continuous with the face provided with the supply port, but not facing the bottom face of the case, and the case comprises a liquid containing pack removably mounted in the case via the opening. Each of the two inner surfaces facing the two outer surfaces of the adapter has a convex portion that complementarily fits into the concave portion when the liquid containing pack is attached, and the area of the outer surface including the concave portion of the adapter and the area of the inner surface including the convex portion of the case each have an asymmetric structure on one side and the other side with respect to a plane perpendicular to the first direction, the concave portion is provided extending over the entire outer surface of the adapter in the first direction, the convex portion is provided extending over the entire inner surface of the case in the first direction, and the cross-sectional area perpendicular to the first direction of the concave portion decreases from one side of the adapter facing the bottom surface of the case to the other side of the adapter facing the opening of the case, and the cross-sectional area perpendicular to the first direction of the convex portion decreases from the bottom surface of the case to the opening of the case .

According to the present invention, the liquid containing pack can be easily stored in the case in the correct orientation without the need for additional parts.

1 is a perspective view of a liquid ejection device in which a liquid storage unit of the present invention is used. FIG. 2 is a perspective view of a liquid storage unit according to the first embodiment. 1 is a perspective plan view of a liquid storage unit according to a first embodiment in a mounted state. FIG. FIG. 11 is a perspective view of a liquid storage unit according to a second embodiment. FIG. 13 is a perspective view of a liquid storage unit according to a third embodiment. FIG. 13 is a perspective view of a liquid storage unit according to a fourth embodiment. FIG. 13 is a perspective view of a liquid storage unit in a comparative example.

The following describes an embodiment of the present invention with reference to the drawings. In this specification, the liquid storage unit of the present invention will be described by taking as an example a case where the liquid storage unit stores ink (liquid) to be supplied to an inkjet recording device (liquid ejection device), but the use of the liquid storage unit is not limited to this. The liquid storage unit of the present invention can also be used in various liquid ejection devices that eject liquids other than ink. The "liquid" mentioned here includes not only materials in a liquid phase state, but also particles of functional materials made of solids such as pigments and metal particles dissolved, dispersed or mixed in a solvent, and representative examples include ink and liquid crystal. The "ink" mentioned here is a pigment dispersed in a solvent as a sedimentation component, and includes various liquid compositions such as general water-based inks and oil-based inks, as well as gel inks and hot melt inks.

FIG. 1 is a perspective view of a liquid ejection device in which a liquid containing pack of the present invention is used.
The liquid ejection device 1 is an inkjet recording device that has a rectangular parallelepiped housing 2 and a liquid ejection head (not shown) provided inside the housing 2, and ejects ink as a liquid from the liquid ejection head to record an image on a recording medium (not shown). The liquid ejection head may be a serial head that reciprocates in a direction intersecting the transport direction of the recording medium, or a line head that is fixed to the device body and does not reciprocate.
The liquid ejection device 1 also has a liquid containing pack 20 that contains the liquid to be supplied to the liquid ejection head, and a case 30 to which the liquid containing pack 20 is detachably attached. The liquid containing pack 20 constitutes a liquid containing unit 10 (see FIG. 2) together with the case 30, and is inserted into a mounting portion 3 that opens at the front of the housing 2 while being contained in the case 30, and is detachably attached. The case 30 can also be attached to the mounting portion 3 alone without containing the liquid containing pack 20. A plurality of mounting portions 3 (four in the illustrated example) are provided side by side in the width direction of the housing 2, and a cover 4 that opens and closes the mounting portion 3 is provided at the opening of the mounting portion 3.

First Embodiment
FIG. 2 is a perspective view of the liquid containing unit according to the first embodiment of the present invention, showing a state in which the liquid containing pack has been removed from the case.
The liquid containing pack 20 has a flat bag body 21 that contains liquid and an adapter 22, and as described above, constitutes the liquid containing unit 10 together with the rectangular parallelepiped case 30 whose top surface, which is the surface with the largest area, is open. In the following description, for the sake of convenience, the downstream side of the liquid containing pack 20 and the case 30 in the mounting direction to the liquid discharge device 1 along the long side of the case 30 (see the outlined arrow in the figure) is referred to as the "front" and the upstream side is referred to as the "rear". In addition, the left side in the left-right direction (the short side direction of the case 30) when facing the mounting direction is referred to as the "left" and the right side is referred to as the "right", and the upper side in the vertical direction (thickness direction of the bag body 60) when the case 30 is placed on a horizontal surface is referred to as the "upper" and the lower side is referred to as the "lower".
The adapter 22 is for connecting the liquid containing pack 20 to the liquid ejection device 1, and is formed in a rectangular parallelepiped shape and attached to the front end (one end) of the bag body 21. The adapter 22 has a bottom surface (hereinafter also referred to as the "adapter bottom surface") 22a, two outer side surfaces (hereinafter also referred to as the "adapter outer side surfaces") 22b that are perpendicularly continuous therewith, and an upper surface (hereinafter also referred to as the "adapter upper surface") 22c opposite the adapter bottom surface 22a. The liquid containing pack 20 is accommodated in the case 30 such that the adapter bottom surface 22a faces the bottom surface (hereinafter also referred to as the "case bottom surface") 30a of the case 30, and both adapter outer side surfaces 22b face both inner side surfaces (hereinafter also referred to as the "case inner side surfaces") 30b of the case 30. When the liquid containing pack 20 is accommodated in the case 30, the adapter upper surface 22c becomes substantially flush with the upper surface (hereinafter also referred to as the "case opening surface") 30c opposite the case bottom surface 30a. The liquid contained in the bag 21 is introduced into the liquid ejection device 1 through a liquid supply section (supply port) 23 exposed at the front surface of the adapter 22 .

Incidentally, a plurality of liquid intake ports (not shown) are provided inside the bag body 21 for taking in the liquid to be introduced into the liquid discharge device 1. These liquid intake ports are arranged asymmetrically vertically inside the bag body 21 in order to supply liquid at a uniform concentration to the liquid discharge device 1 even over time, and therefore the liquid containing pack 20 needs to be placed in the case 30 in the correct vertical orientation. For this reason, in this embodiment, a recess 24 is formed in the adapter 22 of the liquid containing pack 20 and a protrusion 31 is formed in the case 30 as a positioning mechanism for storing the liquid containing pack 20 in the case 30 in the correct vertical orientation. These are designed to fit complementarily with each other when the liquid containing pack 20 is attached to the case 30.
The recess 24 is formed on the adapter outer side surface 22b, extending in the vertical direction (first direction), and opens to the adapter lower surface (one surface) 22a and the adapter upper surface (the other surface) 22c. The protrusion 31 protrudes from the case inner side surface 30b, and is formed extending over the entire case inner side surface 30b along the vertical direction. In addition, the recess 24 has an asymmetric structure on one side and the other side with respect to a plane (a plane parallel to the adapter upper surface 22c and the adapter lower surface 22a) that passes through the center of the height direction (vertical direction) of the adapter 22 and is perpendicular to the height direction of the adapter 22. Specifically, the recess 24 is in the shape of a semicircular truncated cone, the cross-sectional area (transverse area) perpendicular to the height direction of the adapter 22 becoming smaller as it moves away from the adapter lower surface 22a. In contrast, the protrusion 31 is also in the shape of a semicircular truncated cone, the cross-sectional area (transverse area) perpendicular to the height direction (vertical direction) of the case 30 becoming smaller as it moves away from the case bottom surface 30a.

FIG. 3 is a perspective plan view of the area enclosed by the dashed line in FIG. 2, seen from the left side, showing the state in which the adapter 22 is attached to the case 30. As shown in FIG.
Here, the maximum length of the recess 24 in the front-rear direction on the adapter lower surface 22a is L, the maximum length of the recess 24 in the front-rear direction on the adapter upper surface 22c is l, the maximum length of the protrusion 31 in the front-rear direction on the case bottom surface 30a is M, and the maximum length of the recess 24 in the front-rear direction on the case opening surface 30c is m. In this case, the respective dimensions satisfy the relationships L>l, M>m, l>m, and L>M, and in particular, the maximum length M of the protrusion 31 in the front-rear direction on the case bottom surface 30a and the maximum length l of the recess 24 in the front-rear direction on the adapter upper surface 22c satisfy the relationship M>l.
Due to this relationship, even if one were to try to store the liquid containing pack 20 upside down in the case 30, the recessed portion 24 and the protruding portion 31 would not engage properly, and the liquid containing pack 20 would not even be able to be fully stored in the case 30. As a result, it becomes possible to easily store the liquid containing pack 20 in the case 30 in the correct upside down orientation without the need for additional parts such as a handle.

In the illustrated example, the recess 24 and the protrusion 31 are both formed in a semicircular truncated cone shape, but the shapes of the recess 24 and the protrusion 31 are not limited to this. That is, in the illustrated example, the cross sections perpendicular to the up-down direction of the recess 24 and the protrusion 31 are both semicircular, but may be rectangular, for example. Alternatively, the shape of the recess 24 may be different on the left and right adapter outer surfaces 22b, and the shape of the protrusion 31 may also be different on the left and right case inner surfaces 30b. In addition, the protrusion 31 does not have to be formed on the entire case inner surface 30b as long as it is capable of engaging with the recess 24 in the front-rear direction (second direction) so as to be positionally regulated. That is, the protrusion 31 may be formed only on a part of the case inner surface 30b, for example, only on the upper end (the end connected to the case opening surface 30c) of the case inner surface 30b, or only in the area between the case bottom surface 30a and the case opening surface 30c. Also, for example, if the convex portion 31 is formed only in the lower region of the case inner surface 30b, the concave portion 24 may also be formed only in the lower region of the adapter outer surface 22b, i.e., it may not open to the adapter upper surface 22c, but only to the adapter lower surface 22a.

The recess 24 and the protrusion 31 also function as a guide mechanism for guiding the insertion of the liquid containing pack 20 into the case 30 in the vertical direction. Therefore, from the viewpoint of ease of insertion, it is preferable that the diameter (maximum length in the front-to-rear direction) of the semicircle at the upper end face (adapter upper face 22c) of the recess 24 is 50% or less of the diameter of the semicircle at the lower end face (adapter lower face 22a). Similarly, it is preferable that the diameter (maximum length in the front-to-rear direction) of the semicircle at the upper end face (end face opposite to the case bottom face 30a) of the protrusion 31 is 50% or less of the diameter of the semicircle at the lower end face (case bottom face 30a). Alternatively, it is preferable that the gap between the recess 24 and the protrusion 31 is 1 mm or more when the liquid containing pack 20 is contained in the case 30, that is, it is preferable that the difference between the diameter of the semicircle at the lower end face of the recess 24 and the diameter of the semicircle at the upper end face of the protrusion 31 is 1 mm or more.

Second Embodiment
4 is a perspective view of a liquid containing unit according to a second embodiment of the present invention, showing a state in which the liquid containing pack has been removed from the case. Hereinafter, the same components as those in the first embodiment will be denoted by the same reference numerals in the drawings and their description will be omitted, and only the components different from the first embodiment will be described. Furthermore, although not specifically mentioned, modifications applicable to the first embodiment are also applicable to this embodiment.
In this embodiment, the recess 24 is formed only in the lower region of the adapter outer side surface 22b. That is, the recess 24 does not open to the adapter upper surface 22c, and has an inner surface 24a facing the adapter lower surface 22a. In addition, the upper region of the adapter outer side surface 22b where the recess 24 is not formed protrudes outward in the left-right direction from the lower region where the recess 24 is formed. In contrast, the protrusion 31 is also formed only in the lower region of the case inner side surface 30b. That is, the protrusion 31 extends along the height direction of the case 30 from the case bottom surface 30a to a position facing the inner surface 24a of the recess 24 when the liquid containing pack 20 is contained in the case 30. In addition, the case 30 is formed with a notch 32 that exposes the upper region of the adapter outer side surface 22b to the outside when the liquid containing pack 20 is contained in the case 30. As a result, in this embodiment, in addition to the effects obtained in the first embodiment, when inserting or removing the liquid containing pack 20 into or from the case 30, it becomes easier to grasp the liquid containing pack 20 in the upper region of the adapter outer surface 30b, thereby improving operability.

From the viewpoint of ease of gripping the liquid containing pack 20, it is preferable that the height (vertical length) of the upper region of the adapter outer side surface 22b is 50% or more and 80% or less of the height of the entire adapter outer side surface 22b. Also, in this embodiment, from the viewpoint of ease of inserting the liquid containing pack 20 into the case 30, it is preferable that the diameter of the semicircle at the upper end surface (inner surface 24a) of the recess 24 is 50% or less of the diameter of the semicircle at the lower end surface (adapter lower surface 22a). Similarly, it is preferable that the diameter of the semicircle at the upper end surface (position facing the inner surface 24a of the recess 24 when the liquid containing pack 20 is contained in the case 30) is 50% or less of the diameter of the semicircle at the lower end surface (case bottom surface 30a). Alternatively, when the liquid containing pack 20 is contained in the case 30, it is preferable that the gap between the recess 24 and the protrusion 31 is 1 mm or more, in other words, it is preferable that the difference between the diameter of the semicircle at the lower end surface of the recess 24 and the diameter of the semicircle at the upper end surface of the protrusion 31 is 1 mm or more.
Note that, as long as the notch 32 formed in the case 30 sufficiently ensures ease of gripping the liquid containing pack 20, the upper region of the adapter outer side surface 22b does not need to protrude outward in the left-right direction more than the lower region, i.e., the adapter outer side surface 22b may be flat. Also, as long as the notch 32 is formed in the case 30 and the upper region of the adapter outer side surface 22b protrudes outward in the left-right direction more than the lower region, the recessed portion 24 and the protruding portion 31 may be omitted.

Third Embodiment
5 is a perspective view of a liquid containing unit according to a third embodiment of the present invention, showing a state in which the liquid containing pack has been removed from the case. Hereinafter, configurations similar to those in the above-described embodiment will be given the same reference numerals in the drawings and their description will be omitted, and only configurations different from the above-described embodiment will be described. Furthermore, although not specifically mentioned, modifications applicable to the above-described embodiment are also possible in this embodiment.
In this embodiment, the recess 24 is formed in a semi-cylindrical shape, i.e., the cross-sectional area is constant, and the recess 24 is formed only in the lower region of the adapter outer side surface 22b. The protrusion 31 is also formed in a semi-cylindrical shape, i.e., the cross-sectional area is constant, and the recess 24 is formed only in the lower region of the case inner side surface 30b. That is, in this embodiment, as in the first embodiment, the recess 24 and the protrusion 31 are formed asymmetrically in the up and down direction, which makes it possible to easily accommodate the liquid containing pack 20 in the case 30 in the correct up and down direction. From the viewpoint of reliably positioning the liquid containing pack 20 and the case 30, it is preferable that the height of the recess 24 (length in the up and down direction) is 50% or more and 80% or less of the height of the entire adapter outer side surface 22b. Similarly, it is preferable that the height of the protrusion 31 is 50% or more and 80% or less of the height of the entire case inner side surface 30b. The protrusion 31 may be oriented sideways so that both end faces of the semi-cylindrical shape face forward and backward.

Fourth Embodiment
6 is a perspective view of a liquid containing unit according to a fourth embodiment of the present invention, showing a state in which the liquid containing pack has been removed from the case. Hereinafter, configurations similar to those in the above-described embodiments will be given the same reference numerals in the drawings and their description will be omitted, and only configurations different from the above-described embodiments will be described. Furthermore, although not specifically mentioned, modifications applicable to the above-described embodiments are also possible in this embodiment.
This embodiment differs from the third embodiment in that an upper region of the adapter outer side surface 22b where the recess 24 is not formed protrudes outward in the left-right direction more than a lower region, and correspondingly, a notch 32 is formed in the case 30. As a result, in addition to the effects obtained in the third embodiment, like the second embodiment, this embodiment makes it easier to grip the liquid containing pack 20 when inserting it into or removing it from the case 30, thereby improving operability.

Next, the present invention will be explained in more detail by giving specific examples.

Example 1
In this example, the liquid containing unit 10 shown in FIG. 2 was produced, and the liquid containing pack 20 was repeatedly inserted into and removed from the case 30, and its operability was evaluated.
The bag body 21 of the liquid storage pack 20 was prepared with a width (length in the left-right direction) of 60 mm and a depth (length in the front-rear direction) of 200 mm, and the adapter 22 was prepared with a width of 76 mm, a depth of 40 mm, and a height (length in the up-down direction) of 20 mm. In addition, at a position 28 mm away from the front face of the adapter 22, a semicircular truncated cone was formed as the recess 24 with a semicircular diameter of 5.5 mm at the upper end face, a semicircular diameter of 15.5 mm at the lower end face, and a height of 20 mm from the lower end face to the upper end face. Note that the distance from the front face of the adapter 22 means the distance to the center of the cross section of the recess 24 in the depth direction (front-rear direction) (the center of the semicircle in this embodiment), and this also applies when the cross section of the recess 24 is not semicircular (the same applies to the following embodiments). The case 30 was prepared with a width of 80 mm, a depth of 250 mm, a height of 22 mm, and a wall thickness of 2 mm. Furthermore, a semicircular truncated cone with a semicircular diameter of 5 mm at the upper end face, a semicircular diameter of 15 mm at the lower end face, and a height of 20 mm from the lower end face to the upper end face was formed as the protrusion 31 at a position 30 mm away from the front face of the case 30. Note that the distance from the front face of the case 30 means the distance to the center of the cross section of the protrusion 31 (the center of the semicircle in this embodiment) in the depth direction (front-rear direction), and this also applies to cases where the cross section of the protrusion 31 is not semicircular (the same applies to the following embodiments).
In such a liquid containing unit 10, the difference between the diameter (15.5 mm) of the semicircle at the lower end face of the recess 24 and the diameter (5 mm) of the semicircle at the upper end face of the protrusion 31 was sufficiently ensured, so that the liquid containing pack 20 could be easily inserted into the case 30. Furthermore, not only was it easy to determine whether the liquid containing pack 20 should be placed in the case 30 upside down, but it was also impossible to place the liquid containing pack 20 in the case 30 in the opposite orientation to the correct upside down.

Example 2
In this example, a liquid storage unit 10 shown in FIG. 4 was produced, and the same evaluation as in Example 1 was carried out.
The bag 21 of the liquid storage pack 20 was prepared in the same manner as in Example 1, and the adapter 22 was prepared with a width of 76 mm, a depth of 40 mm, and a height of 20 mm, with a range of 10 mm from the adapter top surface 22c protruding 2 mm outward in the left and right directions. In other words, the maximum width of the adapter 22 was 80 mm. In addition, at a position 28 mm away from the front surface of the adapter 22, a semicircular truncated cone was formed as the recess 24, with a semicircular diameter of 7.5 mm at the top surface, a semicircular diameter of 15.5 mm at the bottom surface, and a height of 10 mm from the bottom surface to the top surface. The case 30 was prepared in the same manner as in Example 1, except for the shape of the protrusion 31 and the fact that the notch 32 was formed. That is, a semicircular truncated cone with a semicircular diameter of 7 mm at the upper end face, a semicircular diameter of 15 mm at the lower end face, and a height of 10 mm from the lower end face to the upper end face was formed as the protrusion 31 at a position 30 mm away from the front face of the case 30. The notch 32 was formed in a range of 42 mm from the front face of the case 30 and 10 mm from the opening face 30c.
In such a liquid containing unit 10, the difference between the diameter (15.5 mm) of the semicircle at the lower end surface of the recess 24 and the diameter (7 mm) of the semicircle at the upper end surface of the protrusion 31 was sufficiently ensured, so that the liquid containing pack 20 could be easily inserted into the case 30. Furthermore, when the liquid containing pack 20 was contained in the case 30, the upper region (10 mm x 40 mm) of the adapter outer surface 22c was exposed from the case 30, so that the liquid containing pack 20 was easy to grasp when inserting or removing it. Furthermore, not only was it easy to determine whether the liquid containing pack 20 should be contained in the case 30 upside down, but it was also impossible to contain the liquid containing pack 20 in the case 30 in the opposite direction to the correct upside down direction.

Example 3
In this example, a liquid storage unit 10 shown in FIG. 5 was produced, and the same evaluation as in Example 1 was carried out.
The bag body 21 and adapter 22 of the liquid containing pack 20 were prepared similarly to those in Example 1, except for the shape of the recess 24. That is, the recess 24 was formed as a semi-cylinder with a diameter of 15.5 mm and a height of 10 mm at a position 28 mm away from the front face of the adapter 22. The case 30 was prepared similarly to those in Example 1, except for the shape of the protrusion 31. That is, the protrusion 31 was formed as a semi-cylinder with a diameter of 15 mm and a height of 10 mm at a position 30 mm away from the front face of the case 30.
With such a liquid containing unit 10, not only could it be easily recognized whether the liquid containing pack 20 should be contained in the case 30 in an upside-down direction, but also it was impossible to contain the liquid containing pack 20 in the case 30 in an orientation opposite to the correct upside-down direction.

Example 4
In this example, a liquid storage unit 10 shown in FIG. 6 was produced, and the same evaluation as in Example 1 was carried out.
The bag body 21 and adapter 22 of the liquid containing pack 20 were prepared similarly to those in Example 2, except for the shape of the recess 24. That is, the recess 24 was formed as a semi-cylinder with a diameter of 15.5 mm and a height of 10 mm at a position 28 mm away from the front face of the adapter 22. The case 30 was prepared similarly to those in Example 2, except for the shape of the protrusion 31. That is, the protrusion 31 was formed as a semi-cylinder with a diameter of 15 mm and a height of 10 mm at a position 30 mm away from the front face of the case 30.
In such a liquid containing unit 10, when the liquid containing pack 20 is contained in the case 30, the upper region (10 mm × 40 mm) of the adapter outer side surface 22c is exposed from the case 30, so that the liquid containing pack 20 can be easily gripped when inserting or removing it. Also, not only was it easy to know whether the liquid containing pack 20 should be contained in the case 30 upside down, but it was also impossible to contain the liquid containing pack 20 in the case 30 in the opposite orientation to the correct upside down.

Comparative Example
In this comparative example, the liquid storage unit 10 shown in FIG.
The bag body 21 and adapter 22 of the liquid containing pack 20 were prepared similarly to those in Example 1, except for the shape of the recess 24. That is, the recess 24 was formed as a semi-cylinder with a diameter of 15.5 mm and a height of 20 mm at a position 28 mm away from the front face of the adapter 22. The case 30 was prepared similarly to those in Example 1, except for the shape of the protrusion 31. That is, the protrusion 31 was formed as a semi-cylinder with a diameter of 15 mm and a height of 20 mm at a position 30 mm away from the front face of the case 30.
In such a liquid containing unit 10, it is not easy to know whether the liquid containing pack 20 should be contained in the case 30 upside down, and the liquid containing pack 20 could be contained in the case 30 in the opposite orientation to the correct upside down orientation.

REFERENCE SIGNS LIST 10 Liquid storage unit 20 Liquid storage pack 24 Recess 30 Case 31 Protrusion

Claims (4)

A liquid containing unit comprising: a rectangular parallelepiped case having an opening on one of its maximum area faces; and a liquid containing pack removably mounted in the case via the opening, the liquid containing pack comprising a flat bag for containing liquid, and a rectangular parallelepiped adaptor attached to one end of the bag and having a liquid supply port,
If a direction connecting the opening of the case and a bottom surface facing the opening is defined as a first direction,
the adapter includes a recess extending in the first direction on both outer side surfaces that are continuous with a surface on which the supply port is provided and do not face the bottom surface of the case,
the case is provided with protrusions on both inner surfaces facing both outer surfaces of the adapter on which the recesses are provided, the protrusions being fitted complementarily to the recesses when the liquid containing pack is attached,
a region of the outer surface of the adapter including the recess and a region of the inner surface of the case including the protrusion have asymmetric structures on one side and the other side with respect to a plane perpendicular to the first direction,
the recess is provided to extend over the entire outer surface of the adapter in the first direction, and the protrusion is provided to extend over the entire inner surface of the case in the first direction,
A liquid containing unit in which the cross-sectional area perpendicular to the first direction of the recess decreases from one side of the adapter facing the bottom surface of the case toward the other side of the adapter facing the opening of the case, and the cross-sectional area perpendicular to the first direction of the protrusion decreases from the bottom surface of the case toward the opening . 2. The liquid containing unit according to claim 1, wherein a direction perpendicular to the first direction and parallel to the inner surface of the case is defined as a second direction, a maximum length of the recess on the one surface of the adapter in the second direction is L, a maximum length of the recess on the other surface in the second direction is l, a maximum length of the convex portion on the bottom surface of the case in the second direction is M, and a maximum length of the convex portion at the opening in the second direction is m, and when L>l, M>m, l>m, and L>M, M>l is satisfied. The liquid containment unit according to claim 2 , wherein the l is 50% or less of the L, and the m is 50% or less of the M. The liquid storage unit according to claim 1 , wherein the recess and the protrusion have a semicircular cross section perpendicular to the first direction.

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