Outdoor unit for air conditioner

Abstract

The objective of the present invention is to suppress deformation of a panel part. This outdoor unit for an air conditioner comprises: an enclosure with a space formed inside and having a lower panel (30) defining one side of the space and a base part to which the lower panel (30) is secured; and a plurality of screws (15) securing the lower panel (30) to the base part. A first upper insertion hole (35) through which to insert the screws (15) is formed in an upper portion of the lower panel (30), and a first lower insertion hole and / or the like through which to insert which the screws (15) formed in a lower portion of the lower panel (30). The first upper insertion hole (35) has an insertion portion (35a) through which to insert the screws (15) and an expanding portion (35b) that expands from the insertion portion (35a) in the direction of the first lower insertion hole and / or the like.

Description

Air conditioner outdoor unit

[0001] The present disclosure relates to an outdoor unit of an air conditioner.

[0002] Known outdoor units for air conditioners include a fan mounted on top and a heat exchanger mounted on the bottom, and the air that has undergone heat exchange in the heat exchanger is blown upward (see, for example, Patent Document 1). Patent Document 1 describes an outdoor unit for an upward-blowing air conditioner, in which a blower chamber is disposed on the top of a rectangular parallelepiped housing and a mechanical chamber is disposed below the blower chamber. This outdoor unit has four service panels mounted in front of the mechanical chamber that can be removed for maintenance.

[0003] Japanese Patent Application Laid-Open No. 2022-41571

[0004] The outdoor unit's service panel (hereinafter referred to as the "panel") is fixed to the main body with multiple fixing members (e.g., screws, etc.). Such outdoor units may be subject to impacts, such as being dropped during transportation or installation. When an impact is applied to the outdoor unit, a compressive load acts on the panel between the multiple fixing members, potentially causing the panel to deform and bulge outward.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide an outdoor unit for an air conditioner that can suppress deformation of the panel portion.

[0006] In order to solve the above problems, the outdoor unit of an air conditioner according to the present disclosure employs the following measures: An outdoor unit of an air conditioner according to one aspect of the present disclosure includes a housing having a space formed therein, a panel portion defining one side of the space, and a main body portion to which the panel portion is fixed, and a plurality of fixing members fixing the panel portion to the main body portion, wherein the panel portion has upper insertion holes formed at an upper portion through which the fixing members are inserted and lower insertion holes formed at a lower portion through which the fixing members are inserted, and the upper insertion holes have insertion portions through which the fixing members are inserted and enlarged portions that enlarge from the insertion portions in a direction toward the lower insertion holes.

[0007] According to the present disclosure, deformation of the panel portion can be suppressed.

[0008] FIG. 1 is a perspective view showing an outdoor unit of an air conditioner according to an embodiment of the present disclosure; FIG. 2 is a perspective view showing a lower panel of an outdoor unit of an air conditioner according to an embodiment of the present disclosure; FIG. 3 is a front view showing an enlarged view of a main part (part A) of FIG. 2; FIG. 4 is a front view showing an enlarged view of a main part (part A) of FIG. 2, showing a state in which a screw has been inserted into a screw hole; FIG. 5 is a front view showing an outdoor unit of an air conditioner according to an embodiment of the present disclosure, showing a state in which one side has been lifted up; FIG. 6 is a front view showing an outdoor unit of an air conditioner according to an embodiment of the present disclosure, showing a state in which one side has been dropped; FIG. 7 is a view showing an outdoor unit of an air conditioner according to a comparative example of the present disclosure, and corresponds to FIG. 4.

[0009] Hereinafter, one embodiment of an outdoor unit for an air conditioner according to the present disclosure will be described with reference to the drawings.

[0010] The outdoor unit 1 according to this embodiment is used in an air conditioner. As shown in Fig. 1, the outdoor unit 1 according to this embodiment is divided into left and right panels at the center of the outdoor unit 1. In the following description, the direction in which the two divided panels are aligned is referred to as the "width direction." The direction perpendicular to the "width direction" and the "up-down direction" is referred to as the "front-rear direction."

[0011] The outdoor unit 1 includes a main body 20 that houses a heat exchanger (not shown) therein, and an air blower 10 that is provided above the main body 20. The air blower 10 houses an axial fan 11 therein. The air blower 10 discharges upward the air that has passed through the heat exchanger and flowed into the main body 20 from the sides and rear of the main body 20. The air blower 10 is connected to the upper end of the main body 20.

[0012] The main body 20 has a housing 21 that forms an outer shell, and a heat exchanger (not shown) that is housed in an internal space formed inside the housing 21. In addition to the heat exchanger, the internal space also houses various devices (not shown) such as a compressor and an accumulator.

[0013] The housing 21 has a base 22 that defines the sides and rear of the internal space, and a lower panel (panel) 30 and an upper panel 40 that define the front of the internal space. The base 22 has side walls 22a that define both ends of the internal space in the width direction (the direction in which the two outdoor units 1 are lined up), and a rear wall (not shown) that defines the rear end in the front-to-rear direction.

[0014] The side wall 22a and the rear wall 22b have a plurality of openings formed therein, through which external air can be introduced into the interior space. A heat exchanger is provided along the inner peripheral surfaces of the side wall 22a and the rear wall 22b. The upper panel 40 and the lower panel 30 are fixed to the front surface of the side wall 22a.

[0015] The upper panel 40 defines the front upper portion of the interior space. The upper panel 40 is a plate-shaped member and is detachably attached to the base 22 from the front-to-rear direction (a predetermined direction). Specifically, the upper panel 40 is detachably attached to the side wall portion 22a of the base 22 from the front to the rear. The upper panel 40 integrally includes a flat, plate-shaped planar portion 41 and a curved portion 42 that curves rearward from the other end of the planar portion 41 in the width direction (the end opposite the adjacent outdoor unit 1). An ornament 50 that covers a screw hole formed in the upper panel 40 is provided between the upper panel 40 and the blower portion 10.

[0016] The lower panel 30 defines the front lower portion of the interior space. The lower panel 30 is a plate-shaped member that is detachably attached to the base 22 from the front-to-rear direction (a predetermined direction). More specifically, the lower panel 30 is detachably attached to the side wall portion 22a of the base 22 from the front to the rear. The lower panel 30 integrally includes a flat, plate-shaped planar portion 31 and a curved portion 32 that curves rearward from the other end of the planar portion 31 in the width direction (the end opposite the adjacent outdoor unit 1).

[0017] As shown in Figure 2, the lower panel 30 has a first upper insertion hole 35 formed at the upper end, which is one end in the width direction (the end on the side of the adjacent outdoor unit 1). The lower panel 30 also has a second upper insertion hole 36 formed at the upper end, which is the other end in the width direction. The first upper insertion hole 35 and the second upper insertion hole 36 are arranged side by side at a predetermined interval along the width direction. A bead 33 extending in the width direction is provided below the first upper insertion hole 35.

[0018] The first upper through-hole 35 and the second upper through-hole 36 are holes that penetrate the lower panel 30 in the plate thickness direction. Screws 15 are inserted into the first upper through-hole 35 and the second upper through-hole 36 (see FIG. 4 ). Note that the screws 15 that pass through the first upper through-hole 35 and the second upper through-hole 36 are covered by the upper panel 40, and therefore cannot be seen from the outside when the upper panel 40 and the lower panel 30 are fixed to the base 22.

[0019] The first upper through-hole 35 will be described in detail later. The second upper through-hole 36 is formed in a perfect circular shape. The second upper through-hole 36 is formed to have a diameter slightly larger than the diameter of the shank of the screw 15.

[0020] The lower panel 30 has a first lower through-hole 37 formed at the lower end, which is one end in the width direction. The lower panel 30 also has a second lower through-hole 38 formed at the lower end, which is the center in the width direction. The lower panel 30 has a third lower through-hole 39 formed at the lower end, which is the other end in the width direction. The first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39 are arranged side by side at a predetermined interval along the width direction.

[0021] The first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39 are holes that penetrate the lower panel 30 in the thickness direction. The screws 15 are inserted into the first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39 (see FIG. 1). The first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39 are formed in a perfect circular shape. Furthermore, the first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39 are formed to have a diameter slightly larger than the diameter of the shank of the screw 15.

[0022] The screws 15 each have a shank that passes through each insertion hole, a head 15a provided at the end of the shank, and a washer 15b provided below the head 15a. The shank is a cylindrical member extending along the central axis C2. The tip of the shank of the screw 15 that passes through each insertion hole threads into a threaded hole (not shown) provided in the base 22. In this way, the screws 15 secure the lower panel 30 and the base 22 together.

[0023] Next, the shape of the first upper insertion hole 35 will be described in detail with reference to Figures 3 and 4. As shown in Figures 3 and 4, the first upper insertion hole 35 has a substantially triangular shape. More specifically, it has a shape in which each apex of an isosceles triangle is curved. The first upper insertion hole 35 is formed so that the apex of the isosceles triangle (the point where two equal sides meet) is located at the top and the base is located at the bottom.

[0024] The first upper through-hole 35 has an insertion portion 35a through which the screw 15 is inserted, and an enlarged portion 35b that enlarges from the insertion portion 35a.

[0025] The insertion portion 35a is provided at the apex of an isosceles triangle (the point where two equal sides meet). As shown in Figure 4, the insertion portion 35a is the area between the apex of the isosceles triangle (the point where two equal sides meet) and the vicinity of the center point C1 of the first upper insertion hole 35. The screw 15 inserted through the insertion portion 35a is positioned so as to abut the edge of the apex of the isosceles triangle (the point where two equal sides meet). The radius of curvature of the curved edge of the apex of the isosceles triangle (the point where two equal sides meet) is approximately the same as the radius of curvature of the cylindrical surface of the shank of the screw 15.

[0026] The enlarged portion 35b is formed so as to expand from the insertion portion 35a in the directions toward the respective lower through-holes (first lower through-hole 37, second lower through-hole 38, and third lower through-hole 39). Specifically, the enlarged portion 35b is formed so as to expand from the insertion portion 35a in the directions toward the first lower through-hole 37 (see arrow A1), the second lower through-hole 38 (see arrow A2), and the third lower through-hole 39 (see arrow A3). Note that the direction toward the first lower through-hole 37 may be a direction along a straight line connecting the central axis C2 of the screw 15 inserted through the first upper through-hole 35 and the central axis C2 of the screw 15 inserted through the first lower through-hole 37. The same applies to the directions toward the second lower through-hole 38 and the third lower through-hole 39.

[0027] In this embodiment, the first upper through-hole 35 is formed so that the direction of the first lower through-hole 37 (see arrow A1), the direction of the second lower through-hole 38 (see arrow A2), and the direction of the third lower through-hole 39 (see arrow A3) intersect with the base of the isosceles triangle-shaped first upper through-hole 35. By forming the first upper through-hole 35 in this manner, enlarged portions 35b are positioned between the screw 15 inserted through the first upper through-hole 35 and the first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39, respectively.

[0028] This embodiment provides the following advantageous effects. Impact may be applied to the outdoor unit 1 of the air conditioner, for example, if the outdoor unit 1 is dropped. Specifically, as shown in FIG. 5 , for example, during transportation or installation of the outdoor unit 1, the outdoor unit 1 may be placed on a pallet 3 and transported along with the pallet 3. If an accident occurs at this time, the outdoor unit 1 may be placed on a platform 5 with only one end in the width direction thereof placed on the ground G, with the other end in the width direction thereof floating above the ground G (see FIG. 5 ), and then the other end in the width direction may fall to the ground G (see FIG. 6 ). In this case, an impact is applied to the outdoor unit 1. Specifically, as shown by the arrows in FIG. 6 , the impact is applied from the first lower insertion hole 37, the second lower insertion hole 38, and the third lower insertion hole 39 toward the first upper insertion hole 35.

[0029] When an impact is applied to the outdoor unit 1, a compressive load acts on the lower panel 30 between the plurality of screws 15 (for example, between the screw 15 inserted through the first upper through-hole 35 and the screw 15 inserted through each lower through-hole (the first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39)). When a compressive load acts on the lower panel 30, there is a possibility that the lower panel 30 will be deformed so as to bulge outward from its surface.

[0030] In this embodiment, the first upper through-hole 35 has an insertion portion 35a through which the screw 15 is inserted and an enlarged portion 35b that enlarges from the insertion portion 35a in the direction of the lower through-holes (the first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39). This provides the enlarged portion 35b between the screw 15 inserted through the first upper through-hole 35 and each of the lower through-holes (the first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39). In other words, the screw 15 inserted through the first upper through-hole 35 does not abut against the edge of the first upper through-hole 35 in the direction of each of the lower through-holes (the first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39). Therefore, when an impact is applied to the outdoor unit 1, the screw 15 inserted through the first upper through-hole 35 can move in the direction of each lower through-hole (the first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39), and does not press against the lower panel 30. Therefore, when an impact is applied to the outdoor unit 1, the expanded portion 35b acts as a buffer space to release the impact, thereby reducing the compressive load acting on the lower panel 30. Therefore, deformation of the lower panel 30 can be suppressed.

[0031] Furthermore, in this embodiment, deformation of the lower panel 30 is suppressed simply by forming the enlarged portion 35b in the first upper insertion hole 35. This allows for a reduction in the number of parts compared to suppressing deformation of the lower panel 30 by providing a reinforcing part in the lower panel 30. This therefore improves ease of assembly and reduces costs.

[0032] Furthermore, compared to suppressing deformation of the lower panel 30 by increasing the plate thickness, an increase in the weight of the lower panel 30 can be suppressed. Furthermore, increasing the plate thickness of the lower panel 30 may require modification of the manufacturing equipment (e.g., a mold, etc.) for the lower panel 30. However, in this embodiment, deformation of the lower panel 30 is suppressed simply by forming the enlarged portion 35b in the first upper insertion hole 35, so modification of the manufacturing equipment is not necessary. Therefore, an increase in costs can be suppressed.

[0033] In this embodiment, a plurality of lower insertion holes (first lower insertion hole 37, second lower insertion hole 38, and third lower insertion hole 39) are provided. This allows the lower part of the lower panel 30 to be fixed at a plurality of locations, thereby enabling the lower panel 30 and the base 22 to be firmly fixed together.

[0034] Furthermore, in this embodiment, the enlarged portion 35b of the first upper through-hole 35 expands in the direction of each lower through-hole (the first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39). This makes it possible to reduce the compressive load acting on the lower panel 30 with respect to each lower through-hole (the first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39) even when there are multiple lower through-holes. This makes it possible to suppress deformation of the lower panel 30. In this way, in this embodiment, the lower panel 30 and the base 22 are firmly fixed together, and deformation of the lower panel 30 can be suppressed.

[0035] In this embodiment, the first upper through-hole 35 is formed in a triangular shape. By making the shape of the first upper through-hole 35 relatively simple, the first upper through-hole 35 can be easily formed. Therefore, the lower panel 30 can be easily manufactured.

[0036] Furthermore, in this embodiment, the first upper through-hole 35 is formed so that one side of the triangle intersects with the direction toward each lower through-hole (the first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39). As a result, the enlarged portion 35b of the first upper through-hole 35 is formed so as to enlarge in the direction toward each lower through-hole (the first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39). This reduces the compressive load acting on the lower panel 30 with respect to each lower through-hole (the first lower through-hole 37, the second lower through-hole 38, and the third lower through-hole 39). This suppresses deformation of the lower panel 30.

[0037] In this embodiment, the screw 15 is positioned so that the central axis C2 of the shank is located between the center point C1 of the first upper through-hole 35 and the edge. This positions the screw 15 at a position offset from the center point C1 of the first upper through-hole 35. Therefore, compared to when the screw 15 is positioned at the center point C1 of the first upper through-hole 35 (see FIG. 7 ), the area over which the head 15 a and the washer 15 b protrude from the first upper through-hole 35 can be increased. In other words, the contact area between the head 15 a and the washer 15 b and the lower panel 30 can be increased. Therefore, compared to when the screw 15 is positioned at the center point C1 of the first upper through-hole 35, the screw 15 can more firmly fasten the lower panel 30 to the base 22.

[0038] The present disclosure is not limited to the above-described embodiments and may be modified as appropriate within the spirit and scope of the present disclosure. For example, the second upper through-hole 36 may also have an insertion portion and an enlarged portion, similar to the first upper through-hole 35. However, since the curved portion 32 is formed at the other widthwise end of the lower panel 30, the area near the second upper through-hole 36 is highly rigid and less likely to deform. Therefore, as described in the above embodiment, forming the second upper through-hole 36 into a perfect circle is unlikely to cause any problems. On the other hand, the widthwise end of the lower panel 30 where the first upper through-hole 35 is formed is formed in a flat plate shape, which reduces rigidity and makes it less likely to deform. In this way, providing the enlarged portion 35b in the first upper through-hole 35 formed in the area less likely to deform can more effectively suppress deformation of the lower panel 30.

[0039] The outdoor unit of the air conditioner described in the above-described embodiments can be understood as follows, for example: The outdoor unit of the air conditioner according to a first aspect of the present disclosure comprises a housing (21) having a space formed therein and a panel portion (30) defining one side of the space and a base portion to which the panel portion is fixed, and a plurality of fixing members (15) fixing the panel portion to the base, wherein the panel portion has an upper insertion hole (35) formed in an upper portion thereof through which the fixing member is inserted and lower insertion holes (37, 38, 39) formed in a lower portion thereof through which the fixing member is inserted, and the upper insertion hole has an insertion portion (35a) through which the fixing member is inserted and an enlarged portion (35b) enlarging from the insertion portion in a direction toward the lower insertion hole.

[0040] An impact may be applied to the outdoor unit of an air conditioner, such as when the outdoor unit is dropped. When an impact is applied to the outdoor unit, a compressive load acts on the panel portion between multiple fixing members (for example, between a fixing member inserted through an upper insertion hole and a fixing member inserted through a lower insertion hole). When a compressive load acts on the panel portion, there is a possibility that the panel portion may be deformed so as to bulge outward from the surface.

[0041] In the above configuration, the upper insertion hole has an insertion portion through which the fixing member is inserted and an enlarged portion that enlarges from the insertion portion toward the lower insertion hole. This results in an enlarged portion between the fixing member inserted through the upper insertion hole and the lower insertion hole. In other words, the fixing member inserted through the upper insertion hole does not abut the edge of the upper insertion hole in the direction of the lower insertion hole. Therefore, when an impact is applied to the outdoor unit, the fixing member inserted through the upper insertion hole can move toward the lower insertion hole and does not press against the panel portion. Therefore, when an impact is applied to the outdoor unit, the enlarged portion acts as a buffer space, reducing the compressive load acting on the panel portion. This suppresses deformation of the panel portion.

[0042] Furthermore, in the above configuration, deformation of the panel portion is suppressed simply by forming an enlarged portion in the upper insertion hole. This reduces the number of parts compared to suppressing deformation of the panel portion by providing a reinforcing part in the panel portion. This improves assembly ease and reduces costs.

[0043] Furthermore, compared to suppressing deformation of the panel portion by increasing the plate thickness, the increase in the weight of the panel portion can be suppressed. Furthermore, while increasing the plate thickness of the panel portion may require modification of the manufacturing equipment (e.g., molds, etc.) for the panel portion, the above configuration suppresses deformation of the panel portion simply by forming an enlarged portion in the upper insertion hole, so there is no need to modify the manufacturing equipment. Therefore, increases in costs can be suppressed.

[0044] In addition, the outdoor unit of an air conditioner according to a second aspect of the present disclosure is the same as that of the first aspect, in which a plurality of lower insertion holes are formed in the panel portion, the plurality of lower insertion holes are arranged in a row along the width direction, and the enlarged portion of the upper insertion hole expands in the direction of each of the lower insertion holes.

[0045] In the above-described configuration, a plurality of lower insertion holes are provided, which allows the lower part of the panel unit to be fixed at a plurality of locations, thereby enabling the panel unit and the base unit to be firmly fixed together.

[0046] In addition, in the above configuration, the enlarged portion of the upper insertion hole expands toward each of the lower insertion holes. This reduces the compressive load acting on the panel portion relative to each lower insertion hole, even when there are multiple lower insertion holes. This prevents deformation of the panel portion.

[0047] In this way, with the above-described configuration, the panel portion and the base portion can be firmly fixed together, and deformation of the panel portion can be suppressed.

[0048] In addition, in the outdoor unit of an air conditioner according to a third aspect of the present disclosure, in the second aspect described above, the upper insertion hole is triangular in shape and is formed so that the direction of each of the lower insertion holes intersects with one side of the triangle.

[0049] In the above configuration, the upper insertion hole is formed in a triangular shape. By making the shape of the upper insertion hole relatively simple, the upper insertion hole can be easily formed. Therefore, the panel portion can be easily manufactured.

[0050] In addition, in the above configuration, the upper insertion hole is formed so that the direction toward each lower insertion hole intersects with one side of the triangle. This causes the enlarged portion of the upper insertion hole to expand toward each lower insertion hole. This reduces the compressive load acting on the panel portion with respect to each lower insertion hole. This in turn suppresses deformation of the panel portion.

[0051] In addition, the outdoor unit of an air conditioner according to a fourth aspect of the present disclosure is any of the first to third aspects, wherein the fixing member inserted through the upper insertion hole has a shaft portion extending along a central axis (C2) and inserting through the upper insertion hole, and a head (15a) provided at one end of the shaft portion, and is arranged so that the central axis of the shaft portion is located between the center (C1) and the edge of the upper insertion hole.

[0052] In the above configuration, the fixing member is disposed so that the central axis of the shaft portion is located between the center and edge of the upper insertion hole. This results in the fixing member being disposed at a position offset from the center of the upper insertion hole. Therefore, compared to when the fixing member is disposed at the center of the upper insertion hole, the area over which the head portion protrudes from the upper insertion hole when viewed in the axial direction can be increased. In other words, the contact area between the head portion and the panel portion can be increased. Therefore, compared to when the fixing member is disposed at the center of the upper insertion hole, the fixing member can more firmly fix the panel portion and the base portion. The head portion and the panel portion may be in direct contact with each other, or indirect contact with each other via a washer or the like.

[0053] DESCRIPTION OF SYMBOLS 1: Outdoor unit 3: Pallet 5: Base 10: Blower section 11: Axial flow fan 15: Screw (fixing member) 15a: Head 15b: Washer section 20: Main body section 21: Housing 22: Base section 22a: Side wall section 30: Lower panel (panel section) 31: Flat section 32: Curved section 33: Bead 35: First upper insertion hole 35a: Insertion section 35b: Enlarged section 36: Second upper insertion hole 37: First lower insertion hole 38: Second lower insertion hole 39: Third lower insertion hole 40: Upper panel 41: Flat section 42: Curved section 50: Ornament G: Ground

Claims

1. An outdoor unit for an air conditioner comprising: a housing having a space formed therein, a panel portion defining one side of the space, and a base portion to which the panel portion is fixed; and a plurality of fixing members fixing the panel portion to the base, wherein the panel portion has upper insertion holes formed at its upper portion through which the fixing members are inserted, and lower insertion holes formed at its lower portion through which the fixing members are inserted, and the upper insertion holes have insertion portions through which the fixing members are inserted, and an enlarged portion that expands from the insertion portions in the direction of the lower insertion holes.

2. An outdoor unit for an air conditioner as described in claim 1, wherein a plurality of lower insertion holes are formed in the panel portion, the plurality of lower insertion holes are arranged in a row along the width direction, and the enlarged portion of the upper insertion hole expands in the direction of each of the lower insertion holes.

3. An outdoor unit for an air conditioner according to claim 2, wherein the upper insertion holes are triangular in shape and are formed so that the direction of each of the lower insertion holes intersects with one side of the triangle.

4. An outdoor unit for an air conditioner as described in any one of claims 1 to 3, wherein the fixing member that passes through the upper insertion hole has a shaft portion that extends along a central axis and passes through the upper insertion hole, and a head portion provided at one end of the shaft portion, and is arranged so that the central axis of the shaft portion is positioned between the center and edge of the upper insertion hole.

Images