CN211846791U

CN211846791U - Elevator suspended ceiling with double-layer side frames

Info

Publication number: CN211846791U
Application number: CN201922497066.7U
Authority: CN
Inventors: 王培森; 陆燕
Original assignee: Hangzhou Sword Elevator Co ltd
Current assignee: Hangzhou Sword Elevator Co ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-11-03
Anticipated expiration: 2029-12-31

Abstract

The application discloses an elevator suspended ceiling with double layers of side frames, which comprises a rectangular framework, wherein the framework comprises a first side frame and a second side frame which are mutually overlapped; first side frame is enclosed by two vertical first backup pads and two horizontal first backup pads, and each first backup pad includes: the top edge of the first side wall is fixed with the bottom surface of the top wall; a first transverse fold connected to the bottom edge of the first sidewall and extending inwardly of the frame; the second side frame is enclosed by two vertical second backup pads and two horizontal second backup pads, and each second backup pad includes: a second side wall arranged vertically; the second transverse fold is connected to the top edge of the second side wall and extends back to the inside of the frame, and the bottom surface of the second transverse fold is fixedly attached to the top surface of the first transverse fold; connect in second lateral wall bottom edge and towards the third horizontal book that extends in the frame, this third horizontal book bearing light-passing board's edge, this scheme is for prior art, and the elevator furred ceiling is difficult for collapsing and is out of shape, and can prevent elevator furred ceiling bottom light leak, and pleasing to the eye degree is high.

Description

Elevator suspended ceiling with double-layer side frames

Technical Field

The application relates to the field of elevators, in particular to an elevator suspended ceiling with double-layer side frames.

Background

The elevator suspended ceiling is installed in the elevator car, plays the effect of decoration and illumination. The elevator suspended ceiling with the box body structure is widely applied due to light weight and easy installation of large-area light-transmitting plates. The light-transmitting plate of general elevator furred ceiling is taken and is arranged in the box diapire of box structure, forms and is close flat bottom or the structure of upwards sunken, the light-transmitting plate of this kind of structure be in the inside of box structure all around, and the piece problem all around solves easily.

If the light-transmitting plate is lower than the bottom wall of the box body structure, a lower convex structure similar to a pendant lamp is formed, and a decorative effect with more stereoscopic impression can be obtained. However, in the elevator suspended ceiling of protruding structure down, the light-passing board bearing structure all around exposes outside, as the partly of whole furred ceiling bottom surface, how can prevent the furred ceiling deformation of collapsing down, can guarantee the furred ceiling outward appearance again, is the problem that needs the solution.

SUMMERY OF THE UTILITY MODEL

The application provides a pair of elevator furred ceiling of double-deck side frame for solve the elevator furred ceiling that passes through the bulge down among the prior art, be difficult for collapsing down and warp, and can prevent furred ceiling bottom light leak, beautifully spend high technical problem.

The application provides an elevator suspended ceiling with double layers of side frames, which comprises a rectangular frame, a top wall covered on the top of the frame and a light-transmitting plate covering the bottom of the frame, wherein the frame comprises a first side frame and a second side frame which are mutually overlapped;

first side frame is enclosed by two vertical first backup pads and two horizontal first backup pads, and each first backup pad includes:

the top edge of the first side wall is fixed with the bottom surface of the top wall;

a first transverse fold connected to the bottom edge of the first sidewall and extending inwardly of the frame;

the second side frame is enclosed by two vertical second backup pads and two horizontal second backup pads, and each second backup pad includes:

a second side wall arranged vertically;

the second transverse fold is connected to the top edge of the second side wall and extends back to the inside of the frame, and the bottom surface of the second transverse fold is fixedly attached to the top surface of the first transverse fold;

and the third transverse fold is connected to the bottom edge of the second side wall and extends towards the inside of the frame and supports the edge of the light-transmitting plate.

Several alternatives are provided below, but not as an additional limitation to the above general solution, but merely as a further addition or preference, each alternative being combinable individually for the above general solution or among several alternatives without technical or logical contradictions.

Optionally, the top edge of the first side wall of the longitudinal first supporting plate is connected with a fourth transverse fold, the fourth transverse fold extends towards the inside of the frame, and the top surface of the fourth transverse fold is fixed with the bottom surface of the top wall.

Optionally, the first transverse fold is connected with a supporting step towards the inside of the frame, and the top surface of the supporting step is attached and fixed to the bottom surface of the second transverse fold.

Optionally, the frame still includes the limiting plate, the limiting plate includes:

the fixed wall is vertically arranged, and is attached to the side face, facing the inside of the frame, of the second side wall;

the first fixed transverse fold is connected to the top edge of the fixed wall and extends back to the inside of the frame, and the bottom surface of the first fixed transverse fold is fixedly attached to the top surface of the supporting step;

connect in the fixed wall bottom edge and towards the fixed cross-fold of the second that extends in the frame, this fixed cross-fold of second is provided with spacing post, spacing post cup joints with the light-passing board to inject the light-passing board.

Optionally, the third is violently rolled over one side in towards the frame and is provided with the perpendicular book that upwards extends, should erect the edge of rolling over the bearing light-passing board, erect roll over, the third is violently rolled over and the second lateral wall encloses and establishes to form and dodges the district, should dodge the district and dodge the fixed violently of second and spacing post.

Optionally, the frame further includes a reinforcing bar connected to the transverse first supporting plate, the reinforcing bar including:

the reinforcing wall is vertically arranged and is attached to the side face, facing the inside of the frame, of the first side wall;

the first reinforcing transverse fold is connected to the top edge of the reinforcing wall and extends towards the inside of the frame, and the top surface of the first reinforcing transverse fold is fixed with the bottom surface of the top wall;

a connecting wall connected to one side of the first reinforcing transverse fold facing the inside of the frame and extending downwards;

connect in connecting the wall bottom edge and towards the second of extending in the frame and strengthen the cross-fold, this second is strengthened the cross-fold and is fixed in between second cross-fold and the first fixed cross-fold.

Optionally, the frame further includes a fastening bolt, and the fastening bolt sequentially passes through the supporting step, the second transverse fold, the second reinforcing transverse fold and the first fixing transverse fold and is fixed.

Optionally, the size of the first side frame is larger than that of the second side frame, so that the first side frame and the second side frame form a radially-gathered annular step structure.

Optionally, the top wall includes a plurality of unit walls spliced with each other, and one or more transverse/longitudinal reinforcing ribs are disposed on the top of the unit walls.

Optionally, a plurality of hanging seats are fixed to the top of the top wall, and the hanging seats are arranged in the circumferential direction of the top wall.

The application provides an elevator furred ceiling is difficult for collapsing down and is out of shape, and can prevent elevator furred ceiling bottom light leak, and pleasing to the eye degree is high.

Drawings

Fig. 1 is a schematic structural view of an elevator ceiling with double-layer side frames according to an embodiment provided by the application;

fig. 2 is a schematic structural view of an elevator ceiling with double-layer side frames according to an embodiment provided by the application;

fig. 3 is a schematic diagram of an exploded structure of a double-layer side-frame elevator ceiling according to an embodiment of the present disclosure;

FIG. 4 is a schematic view of the first longitudinal support plate of FIG. 3;

FIG. 5 is a schematic view of the first lateral support plate of FIG. 3;

FIG. 6 is a schematic structural view of the second support plate in FIG. 3;

fig. 7 is a cross-sectional structural schematic view of an elevator ceiling with double-layer side frames according to an embodiment of the present application;

FIG. 8 is an enlarged view of part A of FIG. 7;

fig. 9 is a schematic structural diagram of a limiting plate in fig. 3;

fig. 10 is a schematic structural view of an elevator ceiling with double-layer side frames according to an embodiment provided in the present application;

FIG. 11 is an enlarged view of the portion B of FIG. 10;

FIG. 12 is a schematic view of the structure of the reinforcing strip of FIG. 3;

fig. 13 is a schematic view of the structure of the ceiling of fig. 3.

The reference numerals in the figures are illustrated as follows:

100. an elevator ceiling; 10. a top wall; 11. a cell wall; 111. fixing the edge; 12. reinforcing ribs; 20. a frame; 21. a first side frame; 211. a longitudinal first support plate; 212. a transverse first support plate; 213. a first side wall; 214. first transverse folding; 215. fourthly, transversely folding; 216. supporting a step; 22. a second side frame; 221. a longitudinal second support plate; 222. a transverse second support plate; 223. a second side wall; 224. second transverse folding; 225. third transverse folding; 226. vertically folding; 227. an avoidance zone; 23. a limiting plate; 231. a fixed wall; 232. a first fixed transverse fold; 233. second fixed transverse folding; 234. a limiting column; 24. a reinforcing strip; 241. a reinforcing wall; 242. a first reinforcing transverse fold; 243. a connecting wall; 244. second strengthen the transverse fold; 30. a hanging seat; 40. a light-transmitting plate; 41. a support strip.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In one embodiment, as shown in fig. 1 to 3, the present application provides an elevator ceiling 100, which includes a rectangular frame 20, a top wall 10 covering the top of the frame 20, and a light-transmitting plate 40 covering the bottom of the frame 20, wherein the frame 20 includes a first side frame 21 and a second side frame 22; the first side frame 21 is formed by two longitudinal first supporting plates 211 and two transverse first supporting plates 212; the second side frame 22 is enclosed by two longitudinal second supporting plates 221 and two transverse second supporting plates 222.

The adjacent longitudinal first support plates 211 and the transverse first support plates 212 are connected by welding, and the adjacent longitudinal second support plates 221 and the transverse second support plates 222 are connected by welding.

It should be noted that the transverse direction (i.e., the X direction in fig. 1) and the longitudinal direction (i.e., the Y direction in fig. 1) are perpendicular to each other in the horizontal direction.

Further, as shown in fig. 3, the number of the transparent plates 40 is plural, a supporting strip 41 is disposed between adjacent transparent plates 40, two ends of the supporting strip 41 are respectively fixedly connected with the second supporting plate, and the top surface of the supporting strip 41 is attached to the bottom surface of the transparent plate 40 to shield the gap between two adjacent transparent plates 40.

It will be appreciated that when the light-transmitting plate 40 is mounted on the second support plate, the top surface of the second support plate is first glued and then the light-transmitting plate 40 is stacked on the top surface of the second support plate and adhesively secured thereto. At the same time, glue is applied to the top surfaces of the supporting strips 41 to fix the supporting strips 41 to the two adjacent light-transmitting plates 40, respectively. Light-passing board 40 is in the passenger field of vision, and it is fixed here through the rubber coating bonding, compares to adopt the fastener fixed, is difficult for causing elevator furred ceiling 100 to warp to guarantee elevator furred ceiling 100 outward appearance.

Wherein, the shape, the material and the surface color of the supporting strip 41 can be selected according to actual needs to change the appearance of the supporting strip 41, so that the shape of the elevator suspended ceiling 100 is more beautiful.

In the present embodiment, the number of the transparent plates 40 is three, the number of the support bars 41 is two, and the support bars 41 are disposed between two adjacent transparent plates 40.

Further, as shown in fig. 4, 5 and 6, each of the first support plates includes: a first sidewall 213 vertically arranged, a top edge of the first sidewall 213 being fixed to a bottom surface of the top wall 10; a first transverse fold 214 connected to the bottom edge of the first sidewall 213 and extending inwardly of the frame 20. Each second support plate includes: a second side wall 223 disposed vertically; a second transverse fold 224 connected to the top edge of the second sidewall 223 and extending away from the inside of the frame 20, wherein the bottom surface of the second transverse fold 224 is attached to the top surface of the first transverse fold 214; a third transverse fold 225 connected to the bottom edge of the second sidewall 223 and extending inward of the frame 20, the third transverse fold 225 supporting the edge of the light-transmitting plate 40.

It can be understood that the second transverse fold 224 and the first transverse fold 214 are mutually attached and fixed, so that no gap is formed at the joint of the first side frame 21 and the second side frame 22, light leakage at the bottom of the elevator ceiling 100 is prevented, and the appearance is high. Simultaneously, first crosspiece 214 can strengthen the support intensity of first backup pad, and second crosspiece 224 can strengthen the support intensity of second backup pad to make elevator furred ceiling 100's structural strength increase, can prevent the deformation that collapses under elevator furred ceiling 100.

The size of the first side frame 21 is larger than that of the second side frame 22, so that the first side frame 21 and the second side frame 22 form a radially converging annular step structure. The bottom of the elevator ceiling 100 can be made to protrude downward so that the visual effect of the elevator ceiling 100 has an impact force.

In another embodiment, as shown in fig. 4, a fourth transverse fold 215 is connected to the top edge of the first sidewall 213 of the longitudinal first supporting plate 211, and the fourth transverse fold 215 extends toward the inside of the frame 20, and the top surface of the fourth transverse fold 215 is fixed to the bottom surface of the top wall 10.

It will be appreciated that the fourth cross fold 215 is welded or bolted to the top wall 10. The fourth transverse fold 215 is used for supporting and fixing the top wall 10, and the mounting surface of the first side wall 213 can be enlarged by the fourth transverse fold 215, so as to facilitate the connection between the top wall 10 and the first side frame 21.

The fourth transverse fold 215 is integrally formed with the first sidewall 213, and the fourth transverse fold 215 and the first sidewall 213 can be simultaneously processed to reduce the number of processing steps between the fourth transverse fold 215 and the first sidewall 213. At the same time, the structure between the fourth transverse fold 215 and the first sidewall 213 can be made more firm.

In another embodiment, as shown in fig. 7 and 8, the first lateral fold 214 is connected with a supporting step 216 facing the inside of the frame 20, and the top surface of the supporting step 216 is attached to the bottom surface of the second lateral fold 224.

It will be appreciated that the support step 216 and the second cross-fold 224 are welded or bolted together. The supporting step 216 can reinforce the supporting strength of the first transverse fold 214. When being connected through the bolt between first crosspiece 214 and the second crosspiece 224, be connected between support step 216 and the second crosspiece 224, first crosspiece 214 can shelter from the bolt to make bolt and support step 216 be invisible to the passenger in the car, with the outward appearance of assurance elevator furred ceiling 100. Meanwhile, when the second side frame 22 is mounted on the first side frame 21, the first side wall 213 is attached to the supporting step 216, and can position the second side frame 22.

In another embodiment, as shown in fig. 9, 10 and 11, the frame 20 further includes a limiting plate 23, and the limiting plate 23 includes: a fixing wall 231 vertically arranged, the fixing wall 231 is attached to the side of the second side wall 223 facing the inside of the frame 20; a first fixed transverse fold 232 connected to the top edge of the fixed wall 231 and extending back to the inside of the frame 20, wherein the bottom surface of the first fixed transverse fold 232 is attached and fixed to the top surface of the supporting step 216; a second fixing transverse fold 233 connected to the bottom edge of the fixing wall 231 and extending toward the inside of the frame 20, wherein the second fixing transverse fold 233 is provided with a position-limiting column 234, and the position-limiting column 234 is sleeved with the light-transmitting plate 40 to limit the light-transmitting plate 40.

It will be appreciated that the shape of the restriction plate 23, neglecting the thickness, is substantially "Z" shaped. The movement of the transparent plate 40 in the horizontal direction can be restricted by the positioning of the stopper posts 234. The fixing wall 231 is attached to the second side wall 223, so that the limiting plate 23 is more firmly fixed to the frame 20. Meanwhile, the limit plate 23 can also reinforce the supporting strength of the fixing wall 231.

The transparent plate 40 is provided with a limiting hole, one end of the limiting column 234 is fixed on the second fixed transverse fold 233, and the other end passes through the limiting hole. When the transparent plate 40 is mounted on the second side frame 22, the limiting holes of the transparent plate 40 need to be aligned with the limiting posts 234, and then the limiting posts 234 pass through the limiting holes to place the transparent plate 40 on the second fixing cross-fold 233.

Wherein, the fixed violently book of first fixed violently book 232 and second 233 forms through the top and the bottom of the fixed wall 231 of buckling respectively, through the aforesaid setting, can make limiting plate 23's structure more firm, can play the effect of conveniently processing limiting plate 23 simultaneously.

In this embodiment, the position-limiting column 234 is a cross flat head screw, a nut is welded and fixed on the second fixed transverse fold 233, a through hole corresponding to the screw hole of the nut is formed on the second transverse fold 224, and the cross flat head screw can be screwed in the screw hole, so that the position-limiting column 234 is fixed on the second fixed transverse fold 233. Of course, in other embodiments, the position-limiting column 234 may be other position-limiting units as long as the position-limiting units can limit the position of the light-transmitting plate 40.

In another embodiment, as shown in fig. 11, a vertical fold 226 extending upward is disposed on one side of the third transverse fold 225 facing the inside of the frame 20, the vertical fold 226 supports an edge of the light-transmitting plate 40, and the vertical fold 226, the third transverse fold 225 and the second sidewall 223 surround to form an escape area 227, and the escape area 227 escapes from the second fixed transverse fold 233 and the limiting column 234.

It can be understood that the vertical fold 226 can shield the second fixed transverse fold 233 and the position-limiting column 234, and the second fixed transverse fold 233 and the position-limiting column 234 are invisible to passengers in the car, so as to ensure the appearance of the suspended ceiling. The vertical folds 226 can support the edge of the light-transmitting plate 40 to prevent the bottom surface of the position-limiting pillars 234 and the connection portion of the position-limiting pillars 234 and the second fixing transverse folds 233 from contacting the lower surface of the light-transmitting plate 40.

In another embodiment, as shown in fig. 12, the frame 20 further includes a reinforcing strip 24 connected to the lateral first support plate 212, the reinforcing strip 24 including: a vertically arranged reinforcing wall 241, the reinforcing wall 241 being attached to the side of the first side wall 213 facing the inside of the frame 20; a first reinforcing transverse fold 242 connected to the top edge of the reinforcing wall 241 and extending inward of the frame 20, the top surface of the first reinforcing transverse fold 242 being fixed to the bottom surface of the top wall 10; a connecting wall 243 connected to a side of the first reinforcing cross-fold 242 facing the inside of the frame 20 and extending downward; a second reinforcing transverse fold 244 connected to the bottom edge of the connecting wall 243 and extending inward of the frame 20, the second reinforcing transverse fold 244 being fixed between the second transverse fold 224 and the first fixing transverse fold 232.

It will be appreciated that the first reinforcing crossfold 242 of the reinforcing strip 24 is welded or bolted to the ceiling. The gravity on the first side frame 21 and the second side frame 22 acts on the connection between the first reinforcing transverse fold 242 and the ceiling, and the reinforcing bar 24 can bear the gravity of the first side frame 21 and the second side frame 22 by abutting the reinforcing wall 241 against the first side wall 213 and fixing the second reinforcing transverse fold 244 between the second transverse fold 224 and the first fixing transverse fold 232.

Wherein, strengthen wall 241, first enhancement cross-fold 242, connecting wall 243 and the second enhancement cross-fold 244 and be integrative setting, can make the structure of strengthening strip 24 more firm, can play the effect of conveniently processing strengthening strip 24 simultaneously.

Further, the frame 20 further includes fastening bolts which pass through the support step 216, the second cross fold 224, the second reinforcing cross fold 244, and the first fixing cross fold 232 in sequence and are fixed.

It will be appreciated that the provision of the fastening bolts can serve to secure the support step 216, the second cross-fold 224, the second reinforcing cross-fold 244 and the first fixing cross-fold 232 to one another.

In another embodiment, as shown in fig. 13, the top wall 10 comprises a plurality of unit walls 11 spliced to each other, and one or more transverse/longitudinal reinforcing ribs 12 are provided on the top of the unit walls 11.

It will be understood that adjacent cell walls 11 are secured to each other by welding or fastening bolts, and the reinforcing ribs 12 are secured to the tops of the cell walls 11 by welding or fastening bolts. A plurality of unit walls 11 are spliced to each other to facilitate the assembly of the top wall 10, and the reinforcing ribs 12 are provided to reduce the deformation of the top wall 10.

Specifically, the cell wall 11 is bent to form a fixing edge 111 toward one side of the adjacent cell wall 11, and the adjacent two fixing edges 111 are attached and fixed to each other by welding or fastening bolts. The provision of the fixing edge 111 also has the effect of reinforcing the cell wall 11 to reduce deformation of the top wall 10.

In the present embodiment, the top wall 10 includes three unit walls 11 joined to each other, and each unit wall 11 is provided with a reinforcing rib 12 extending in the longitudinal direction. Of course, in other embodiments, the top wall 10 may be formed by splicing one, two or more than three unit walls 11.

In another embodiment, as shown in fig. 13, a plurality of hanging seats 30 are fixed to the top of the top wall 10, and the plurality of hanging seats 30 are arranged in the circumferential direction of the top wall 10.

It will be appreciated that the hanger bracket 30 is used to connect the side frame reinforced elevator ceiling 100 and the car roof, and the hanger bracket 30 is fixed to the roof wall 10 by welding or fastening bolts. To reduce deformation of the top wall 10, the hanger holders 30 are connected to the longitudinal support plates and/or the lateral support plates through the top wall 10 when the hanger holders 30 are mounted on the top wall 10.

In the present embodiment, the number of the hanging seats 30 is four, and the four hanging seats 30 are fixed to four corners (connecting portions between the vertical support plates and the horizontal support plates) of the side frames, respectively. Of course, in other embodiments, the number of hanging seats 30 is also two, three or more.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features. When technical features in different embodiments are represented in the same drawing, it can be seen that the drawing also discloses a combination of the embodiments concerned.

The above examples only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application.

Claims

1. The elevator suspended ceiling with double layers of side frames comprises a rectangular frame, a top wall covered at the top of the frame and a light-transmitting plate for shielding the bottom of the frame, and is characterized in that the frame comprises a first side frame and a second side frame which are mutually overlapped;

a second side wall arranged vertically;

2. The double-decked side-framed elevator ceiling of claim 1, wherein a fourth cross-fold is attached to a top edge of the first side wall of the longitudinal first support panel and extends inwardly of the frame, the fourth cross-fold top surface being secured to a bottom surface of the top wall.

3. The double-layer side frame elevator ceiling of claim 1, wherein the first transverse fold is connected with a supporting step towards the inside of the frame, and the top surface of the supporting step is fixedly attached to the bottom surface of the second transverse fold.

4. The double-decked side frame elevator ceiling of claim 3, wherein the frame further comprises a limiting plate, the limiting plate comprising:

5. The elevator suspended ceiling with the double-layer side frames as claimed in claim 4, wherein one side of the third transverse fold facing the inside of the frame is provided with an upward extending vertical fold, the vertical fold supports the edge of the light-transmitting plate, and the vertical fold, the third transverse fold and the second side wall are surrounded to form an avoiding area which avoids the second fixed transverse fold and the limiting column.

6. The double-decker side-framed elevator ceiling of claim 4, wherein the frame further comprises a reinforcing strip connected to the transverse first support panel, the reinforcing strip comprising:

7. The double-decked side-frame elevator ceiling of claim 6, wherein the frame further comprises fastening bolts that pass through and are fastened to the support step, the second cross fold, the second reinforcing cross fold, and the first fastening cross fold in this order.

8. The double-decker side frame elevator ceiling of claim 1, wherein the first side frame is sized larger than the second side frame such that the first and second side frames form a radially converging annular step structure.

9. The double side frame elevator ceiling of claim 1, wherein the top wall comprises a plurality of cell walls spliced to one another, the top of the cell walls being provided with one or more transverse/longitudinal disposed reinforcing ribs.

10. The double-decked side frame elevator ceiling of claim 1, wherein a plurality of hanger seats are fixed to a top portion of the top wall, the plurality of hanger seats being arranged in a circumferential direction of the top wall.