Flip packaging box blank and flip packaging box with arc-shaped box cover
By replacing the sharp corner shape with a curved end at the front side of the box body of the flip packaging box, the problem of easy deformation of the box body is solved, achieving a more durable and suitable packaging effect for innovative products.
Patent Information
- Application Number
- CN202422026393.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-20
- Publication Date
- 2025-07-29
- Estimated Expiration
- 2034-08-20
AI Technical Summary
The sharp corners of the box body of a conventional flip box are prone to deformation due to collision, resulting in damage, especially after the thickness of the jam is reduced, the problem is more significant, causing unnecessary losses.
The sharp corner shapes of the left side plate in front of the box body and the right side plate in front of the box body are replaced with a first arc-shaped end extending along an arc line toward the front side plate of the box body, and a second arc-shaped end that cooperates with it is formed on the front side plate of the box cover to form an inclined arc-shaped joint.
It reduces deformation and damage caused by collision during transportation and packaging during unpacking, improves the durability of the packaging box, and is suitable for packaging of innovative products.
Smart Images

Figure CN223162192U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of packaging and printing, in particular to a flip-top box blank and a flip-top box with an arc-shaped box cover made of the flip-top box blank. Background Art
[0002] See Figure 1 and Figure 2 As shown in
[0003] and Figure 1 and Figure 2 In the unfolded flat state, the structure of the box cover 1 and the box body 2 of the flip-top box is generally as follows: the box cover front side plate 102 and the box cover rear side plate 103 are integrally connected to the upper and lower directions of the box cover top plate 101 along the fold lines respectively, the left top flap 104 and the right top flap 105 are integrally connected to the left and right directions of the box cover top plate 101 along the fold lines respectively, the inner flap 106 is integrally connected to the upper side of the box cover front side plate 102 along the fold line, the box cover front left side plate 107 and the box cover front right side plate 108 are integrally connected to the left and right directions of the box cover front side plate 102 along the fold lines respectively, the lower side of the box cover rear side plate 103 is integrally connected to the box body rear side plate 203 along the fold line, and the box cover rear left side plate 109 and the box cover rear right side plate 110 are integrally connected to the left and right directions of the box cover rear side plate 103 along the fold lines respectively; the box body bottom plate 201 is integrally connected to the box body front side plate 202 and the box body rear side plate 203 along the fold lines in the upper and lower directions respectively, the left bottom flap 204 and the right bottom flap 205 are integrally connected to the left and right directions of the box body bottom plate 201 along the fold lines respectively, the box body front left side plate 206 and the box body front right side plate 207 are integrally connected to the left and right directions of the box body front side plate 202 along the fold lines respectively, and the box body rear left side plate 208 and the box body rear right side plate 209 are integrally connected to the left and right directions of the box body rear side plate 203 along the fold lines respectively.
[0004] See Figure 1 and Figure 2 However, after the lid 1 and the box body 2 of a conventional flip-top packaging box are fastened and in contact with each other, inclined linear seams 3 that extend obliquely are formed in cooperation with the lid 1 on the relatively spaced left and right side surfaces of the box body 2. In order to show this linear seam 3, it is necessary to extend pointed corner shapes at the trailing edges of the front left side panel 206 and the front right side panel 207 of the box body. The pointed corner shape is formed by two straight edges on the outer edge in an acute angle crossing form. It is itself prone to being collided and deformed, and the angle of the pointed corner will gradually decrease as the thickness of the cardboard used for the flip-top packaging box becomes thinner. Coupled with cost savings, the thickness of the cardboard used for processing the flip-top packaging box has been continuously thinned with the improvement of the processing technology. This results in that when the flip-top packaging box blank is in the unfolded flat state before being packaged and formed, the pointed corners of the box body 2 are more likely to be collided and deformed, thus damaging the entire flip-top packaging box and causing unnecessary losses. Content of the Utility Model
[0005] In order to solve the above technical problems, the present utility model provides a flip-top packaging box blank that can avoid collision deformation.
[0006] The present utility model adopts the following technical solutions:
[0007] The present utility model provides a flip-top packaging box blank, including a lid top plate and a box body bottom plate;
[0008] The front and rear side panels of the lid are integrally connected to the lid top plate along folding lines in the up and down directions respectively. The front left and right side panels of the lid are integrally connected to the front side panel of the lid along folding lines in the left and right directions respectively. The rear left and right side panels of the lid are integrally connected to the rear side panel of the lid along folding lines in the left and right directions respectively.
[0009] The front and rear side panels of the box body are integrally connected to the box body bottom plate along folding lines in the up and down directions respectively. The front left and right side panels of the box body are integrally connected to the front side panel of the box body along folding lines in the left and right directions respectively. The rear left and right side panels of the box body are integrally connected to the rear side panel of the box body along folding lines in the left and right directions respectively.
[0010] The rear side panel of the lid is integrally connected to the rear side panel of the box body along a folding line. The front left side panel and the front right side panel of the box body both extend a first arc end at the trailing edge, and the first arc end extends along an arc towards the front side panel of the box body. Moreover, the front left side panel and the front right side panel of the lid both extend a second arc end corresponding to and cooperating with the first arc end at the trailing edge.
[0011] Preferably, a concave recessed end is formed at the tail edge of the front side plate of the box body. The two sides of the recessed end are in an arc shape, and the middle part is in a straight line shape. The arc shapes on both sides are connected to the straight line shape in the middle to form a continuous structure. A shaping structure matching the recessed end is formed at the upper edge of the front side plate of the box cover.
[0012] Preferably, an inner folding piece is integrally connected along a fold line at the upper part of the front side plate of the box cover. Circular arcs adapted to the front side plate of the box cover are formed at both ends of the inner folding piece in the left-right direction at the fold line. A left top folding piece and a right top folding piece are integrally connected along fold lines at the left and right directions of the top plate of the box cover respectively. A left bottom folding piece and a right bottom folding piece are integrally connected along fold lines at the left and right directions of the bottom plate of the box body respectively.
[0013] Preferably, the length L2 of the inner folding piece extending in the left-right direction is 1-5 mm shorter than the length L1 of the front side plate of the box cover extending in the left-right direction, and the gap G between the actual folding line of the inner folding piece and the fold line is 0.5-1.5 mm.
[0014] Preferably, the width H2 of the inner folding piece extending in the up-down direction is 2-10 mm shorter than the width H1 of the front side plate of the box cover extending in the up-down direction.
[0015] Preferably, the radius R3 of the upper arc of the inner folding piece is 1-3 mm smaller than the radius R2 of the upper arc of the front side plate of the box cover.
[0016] Preferably, the entire box blank is made of cardboard with a basis weight of 150 g / m 2 ~300 g / m 2 .
[0017] The present invention also provides a flip-top packaging box with an arc-shaped box cover, which adopts the box blank of any one of the above flip-top packaging boxes;
[0018] The front side plate of the box cover and the rear side plate of the box cover are bent in the same direction. The front left side plate of the box cover and the rear left side plate of the box cover are bent and adhesively bonded. The front right side plate of the box cover and the rear right side plate of the box cover are bent and adhesively bonded. The front side plate of the box cover, the rear side plate of the box cover, the rear left side plate of the box cover and the rear right side plate of the box cover are adhesively bonded in the bent state to form a box cover with a bottom opening and in a cuboid shape;
[0019] The front side plate of the box body and the rear side plate of the box body are bent in the same direction. The front left side plate of the box body and the rear left side plate of the box body are bent and adhesively bonded. The front right side plate of the box body and the rear right side plate of the box body are bent and adhesively bonded. The front side plate of the box body, the rear side plate of the box body, the rear left side plate of the box body and the rear right side plate of the box body are adhesively bonded in the bent state to form a box body with a top opening and in a cuboid shape;
[0020] When the box cover is rotated around the fold line and buckled on the box body, arc-shaped seams extending obliquely are formed on two opposite side faces of the box body at intervals.
[0021] Compared with the prior art, the beneficial effects of the present invention are:
[0022] In the flip-top packaging box blank of the present utility model, the sharp corners extended from the left front side panel and the right front side panel of the box body at the tail edge are replaced by first arc-shaped ends extending along an arc towards the front side panel of the box body, so that the flat box blank before packaging and forming is not easily deformed and damaged due to collision during packaging and transportation, reducing unnecessary losses.
[0023] In the flip-top packaging box with an arc-shaped box cover of the present utility model, due to the adoption of the above-mentioned flip-top packaging box blank, an arc-shaped seam extending obliquely is formed on the assembled packaging box. Compared with the straight seam on the conventional flip-top packaging box, it is also more suitable for packaging innovative products. Description of the Drawings
[0024] Figure 1 It is a schematic diagram of the box blank of a conventional flip-top packaging box in the background art.
[0025] Figure 2 It is a schematic structural diagram of a conventional flip-top packaging box in the background art.
[0026] Figure 3 It is a schematic diagram of the shape of the flip-top packaging box blank in the embodiment of the present utility model.
[0027] Figure 4 It is a schematic structural diagram of the first shape of the flip-top packaging box with an arc-shaped box cover in the embodiment of the present utility model.
[0028] Figure 5 It is a schematic structural diagram of the second shape of the flip-top packaging box with an arc-shaped box cover in the embodiment of the present utility model.
[0029] Figure 6 It is a schematic structural diagram of the third shape of the flip-top packaging box with an arc-shaped box cover in the embodiment of the present utility model.
[0030] Among them, the description of the reference numerals is as follows:
[0031] 1, box cover; 202, front side panel of the box body
[0032] 101, top panel of the box cover; 203, rear side panel of the box body
[0033] 102, front side panel of the box cover; 204, left bottom flap
[0034] 103, rear side panel of the box cover; 205, right bottom flap
[0035] 104, left top flap; 206, left front side panel of the box body
[0036] 105, right top flap; 207, right front side panel of the box body
[0037] 106, inner flap; 208, left rear side panel of the box body
[0038] 107. Front left side plate of the box cover, 209. Rear right side plate of the box body
[0039] 108. Front right side plate of the box cover, 3. Linear seam
[0040] 109. Rear left side plate of the box cover, 4. First arcuate end
[0041] 110. Rear right side plate of the box cover, 5. Second arcuate end
[0042] 2. Box body, 6. Concave end
[0043] 201. Bottom plate of the box body, 7. Curvilinear seam Detailed implementation manners
[0044] The following further elaborates in detail the detailed implementation manners of the present utility model in conjunction with the attached drawings. These implementation manners are only used to illustrate the present utility model and are not intended to limit the present utility model.
[0045] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the attached drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.
[0046] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0047] In addition, in the description of the present utility model, unless otherwise stated, the meaning of "a plurality of" is two or more.
[0048] See Figure 3 , this embodiment provides a flip-top packaging box blank, including a box cover top plate 101 and a box body bottom plate 201;
[0049] The top and bottom directions of the top plate 101 of the box cover are integrally connected with the front side plate 102 and the rear side plate 103 of the box cover along the fold lines respectively. The left and right directions of the front side plate 102 of the box cover are integrally connected with the front left side plate 107 and the front right side plate 108 of the box cover along the fold lines. The left and right directions of the rear side plate 103 of the box cover are integrally connected with the rear left side plate 109 and the rear right side plate 110 of the box cover along the fold lines;
[0050] The top and bottom directions of the bottom plate 201 of the box body are integrally connected with the front side plate 202 and the rear side plate 203 of the box body along the fold lines respectively. The left and right directions of the front side plate 202 of the box body are integrally connected with the front left side plate 206 and the front right side plate 207 of the box body along the fold lines. The left and right directions of the rear side plate 203 of the box body are integrally connected with the rear left side plate 208 and the rear right side plate 209 of the box body along the fold lines;
[0051] The rear side plate 103 of the box cover is integrally connected with the rear side plate 203 of the box body along the fold line. Both the front left side plate 206 and the front right side plate 207 of the box body extend a first arc end 4 at the tail edge, and the first arc end 4 extends along an arc towards the front side plate 202 of the box body. Moreover, both the front left side plate 107 and the front right side plate 108 of the box cover correspondingly extend a second arc end 5 at the tail edge that matches the first arc end 4.
[0052] See Figure 3 , the flip-top packaging box blank of this embodiment replaces the sharp corner shapes extended at the tail edges of the front left side plate 206 and the front right side plate 207 of the box body with the first arc ends 4 that extend along an arc towards the front side plate 202 of the box body, so that the flat box blank before being packaged and formed is not easily deformed and damaged due to being collided during the packaging and transportation processes, reducing unnecessary losses.
[0053] In addition, see Figure 3 and Figure 4 , when assembling the flip-top packaging box blank, the front side plate 102 and the rear side plate 103 of the box cover are bent in the same direction. The front left side plate 107 and the rear left side plate 109 of the box cover are bent and adhesively bonded. The front right side plate 108 and the rear right side plate 110 of the box cover are bent and adhesively bonded. The front side plate 102, the rear side plate 103, the rear left side plate 109, and the rear right side plate 110 of the box cover are adhesively bonded in the bent state to form a box cover 1 with a bottom opening and a cuboid shape; the front side plate 202 and the rear side plate 203 of the box body are bent in the same direction. The front left side plate 206 and the rear left side plate 208 of the box body are bent and adhesively bonded. The front right side plate 207 and the rear right side plate 209 of the box body are bent and adhesively bonded. The front side plate 202, the rear side plate 203, the rear left side plate 208, and the rear right side plate 209 of the box body are adhesively bonded in the bent state to form a box body 2 with a top opening and a cuboid shape.
[0054] Preferably, see Figure 3, a concave recessed end 6 is formed at the tail edge of the front side plate 202 of the box body. The two sides of the recessed end 6 are in an arc shape, and the middle part is in a straight line shape. The arc shapes on both sides are connected to the straight line shape in the middle to form a continuous structure. A shaping structure matching the recessed end 6 is formed at the upper edge of the front side plate 102 of the box cover.
[0055] It should be noted that the specific radian of the arc radius R1 of the first arc end 4 and the arc radius R2 of the recessed end 6 is set according to the design requirements; and the contour shape of the recessed end 6 can be formed into various continuous structures by die-cutting according to the design, such as Figures 4 to 6 shown.
[0056] Preferably, referring to Figure 3 , an inner folding piece 106 is integrally connected along a fold line to the upper edge of the front side plate 102 of the box cover. Arcs adapted to the front side plate 102 of the box cover are formed at both ends of the inner folding piece 106 in the left-right direction at the fold line. A left top folding piece 104 and a right top folding piece 105 are integrally connected along fold lines to the left and right directions of the top plate 101 of the box cover respectively. Left bottom folding pieces 204 and right bottom folding pieces 205 are integrally connected along fold lines to the left and right directions of the bottom plate 201 of the box body respectively.
[0057] Referring to Figure 3 , the inner folding piece 106 is used to be bent and attached to the inner wall of the front side plate 102 of the box cover during assembly. The left top folding piece 104 is used to be correspondingly bent and attached between the front left side plate 107 and the rear left side plate 109 of the box cover during assembly. The right top folding piece 105 is used to be correspondingly bent and attached between the front right side plate 108 and the rear right side plate 110 of the box cover during assembly. The left bottom folding piece 204 is used to be correspondingly bent and attached between the front left side plate 206 and the rear left side plate 208 of the box body during assembly, while the right bottom folding piece 205 is used to be correspondingly bent and attached between the front right side plate 207 and the rear right side plate 209 of the box body during assembly to enhance the box body strength of the packaging box.
[0058] Preferably, referring to Figure 3 , the length L2 of the inner folding piece 106 extending in the left-right direction is 1 - 5 mm shorter than the length L1 of the front side plate 102 of the box cover extending in the left-right direction, and the gap G between the actual folding line of the inner folding piece 106 and the fold line is 0.5 - 1.5 mm, so as to prevent the inner folding piece 106 from being exposed after folding and ensure the packaging quality.
[0059] Preferably, referring to Figure 3 , the width H2 of the inner folding piece 106 extending in the up-down direction is 2 - 10 mm shorter than the width H1 of the front side plate 102 of the box cover extending in the up-down direction.
[0060] Preferably, the radius R3 of the upper arc of the inner folding piece 106 is 1 - 3 mm smaller than the radius R2 of the upper arc of the front side plate 102 of the box cover.
[0061] Preferably, the entire box blank is made of cardboard with a basis weight of 150 g / m 2 ~300 g / m 2 .
[0062] Specifically, when the above-mentioned flip-top box blank is used for bonding and assembling a cigarette box, a good packaging effect is achieved. The cigarette box is made of cardboard with a basis weight of 245 g / m 2 . The radius R1 of the arc of the first arc end 4 is 9 mm, the radius R2 of the arc of the concave end 6 is 14 mm, the length L2 of the inner folding piece 106 extending in the left-right direction is 52 mm, the length L1 of the front side plate 102 of the box cover extending in the left-right direction is 55 mm, the gap G between the actual folding line and the folding line of the inner folding piece 106 is 1 mm, the radius R3 of the arc on the inner folding piece 106 is 9 mm, the width H2 of the inner folding piece 106 extending in the up-down direction is 22 mm, and the width H1 of the front side plate 102 of the box cover extending in the up-down direction is 26 mm.
[0063] See Figure 3 and Figure 4 , this embodiment also provides a flip-top box with an arc-shaped box cover, using the above-mentioned flip-top box blank;
[0064] The front side plate 102 of the box cover and the rear side plate 103 of the box cover are bent in the same direction. The front left side plate 107 of the box cover and the rear left side plate 109 of the box cover are bent and adhesively bonded. The front right side plate 108 of the box cover and the rear right side plate 110 of the box cover are bent and adhesively bonded. The front side plate 102 of the box cover, the rear side plate 103 of the box cover, the rear left side plate 109 of the box cover, and the rear right side plate 110 of the box cover are adhesively bonded in the bent state to form a box cover 1 with a bottom opening and a cuboid shape;
[0065] The front side plate 202 of the box body and the rear side plate 203 of the box body are bent in the same direction. The front left side plate 206 of the box body and the rear left side plate 208 of the box body are bent and adhesively bonded. The front right side plate 207 of the box body and the rear right side plate 209 of the box body are bent and adhesively bonded. The front side plate 202 of the box body, the rear side plate 203 of the box body, the rear left side plate 208 of the box body, and the rear right side plate 209 of the box body are adhesively bonded in the bent state to form a box body 2 with a top opening and a cuboid shape;
[0066] When the box cover 1 is rotated around the folding line and buckled on the box body 2, arc-shaped seams 7 extending obliquely are formed on the two opposite sides of the box body 2 at intervals.
[0067] Since the flip-top box with an arc-shaped box cover in this embodiment uses the above-mentioned flip-top box blank, arc-shaped seams 7 extending obliquely are formed on the assembled box. Compared with the straight seams 3 on the conventional flip-top box, it is also more suitable for packaging innovative products.
[0068] In addition, since the blank of the flip-top packaging box with an arc-shaped lid in this embodiment has little structural difference from that of a conventional flip-top packaging box, some simple adjustments or improvements can be made on the existing packaging machine to achieve mechanical automated packaging without re-customizing packaging equipment, reducing the investment in equipment development.
[0069] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, several improvements and substitutions can be made without departing from the technical principle of the present invention, and these improvements and substitutions should also be regarded as the protection scope of the present invention.
Claims
1. A flip-top box blank, characterized in that, It includes a lid top plate (101) and a box body bottom plate (201); The lid top plate (101) is integrally connected with a lid front side plate (102) and a lid rear side plate (103) along a broken line in the up and down directions respectively. The lid front side plate (102) is integrally connected with a lid front left side plate (107) and a lid front right side plate (108) along a broken line in the left and right directions. The lid rear side plate (103) is integrally connected with a lid rear left side plate (109) and a lid rear right side plate (110) along a broken line in the left and right directions; The box body bottom plate (201) is integrally connected with a box body front side plate (202) and a box body rear side plate (203) along a broken line in the up and down directions respectively. The box body front side plate (202) is integrally connected with a box body front left side plate (206) and a box body front right side plate (207) along a broken line in the left and right directions. The box body rear side plate (203) is integrally connected with a box body rear left side plate (208) and a box body rear right side plate (209) along a broken line in the left and right directions; The lid rear side plate (103) is integrally connected with the box body rear side plate (203) along a broken line. Both the box body front left side plate (206) and the box body front right side plate (207) extend a first arc end (4) at the tail edge. The first arc end (4) extends along an arc towards the box body front side plate (202), and both the lid front left side plate (107) and the lid front right side plate (108) extend a second arc end (5) corresponding to and cooperating with the first arc end (4) at the tail edge.
2. The flip-top packaging box blank according to claim 1, characterized in that, A concave depression end (6) is formed at the tail edge of the box body front side plate (202). The two sides of the depression end (6) are in an arc shape and the middle part is in a straight line shape. The arc shapes on both sides are connected to the straight line shape in the middle to form a continuous structure. A shaping structure cooperating with the depression end (6) is formed at the upper edge of the lid front side plate (102).
3. The flip-top packaging box blank according to claim 2, wherein, An inner folding piece (106) is integrally connected with the upper part of the lid front side plate (102) along a broken line. Arcs adapted to the lid front side plate (102) are formed at both ends of the inner folding piece (106) in the left and right directions at the broken line. A left top folding piece (104) and a right top folding piece (105) are integrally connected with the lid top plate (101) along a broken line in the left and right directions respectively. A left bottom folding piece (204) and a right bottom folding piece (205) are integrally connected with the box body bottom plate (201) along a broken line in the left and right directions respectively.
4. The flip-top box blank according to claim 3, wherein, The length L2 of the inner folding piece (106) extending in the left and right directions is 1 - 5 mm shorter than the length L1 of the lid front side plate (102) extending in the left and right directions, and the gap G between the actual folding line of the inner folding piece (106) and the broken line is 0.5 - 1.5 mm.
5. The flip-top packaging box blank according to claim 3, characterized in that, The width H2 of the inner folding piece (106) extending in the up and down directions is 2 - 10 mm shorter than the width H1 of the lid front side plate (102) extending in the up and down directions.
6. The flip-top packaging box blank according to claim 3, characterized in that, The radius R3 of the upper arc of the inner folding piece (106) is 1 - 3 mm smaller than the radius R2 of the upper arc of the lid front side plate (102).
7. The flip-top packaging box blank according to claim 1, wherein, The entire box blank is made of cardboard with a basis weight of 150 g / m 2 ~300 g / m 2 .
8. A flip-top packaging box with an arc-shaped lid, characterized in that, Use the flip-top packaging box blank according to any one of claims 1-7; the front side plate (102) of the box cover and the rear side plate (103) of the box cover are bent in the same direction, the front left side plate (107) of the box cover and the rear left side plate (109) of the box cover are bent and adhesively bonded, the front right side plate (108) of the box cover and the rear right side plate (110) of the box cover are bent and adhesively bonded, and the front side plate (102) of the box cover, the rear side plate (103) of the box cover, the rear left side plate (109) of the box cover, and the rear right side plate (110) of the box cover are adhesively bonded in the bent state to form a box cover (1) with a bottom opening and a cuboid shape; The front side plate (202) of the box body and the rear side plate (203) of the box body are bent in the same direction, the front left side plate (206) of the box body and the rear left side plate (208) of the box body are bent and adhesively bonded, the front right side plate (207) of the box body and the rear right side plate (209) of the box body are bent and adhesively bonded, and the front side plate (202) of the box body, the rear side plate (203) of the box body, the rear left side plate (208) of the box body, and the rear right side plate (209) of the box body are adhesively bonded in the bent state to form a box body (2) with a top opening and a cuboid shape; When the box cover (1) is rotationally buckled on the box body (2) around the folding line, arc-shaped seams (7) extending obliquely are formed on two opposite side surfaces of the box body (2) at intervals.