CN114302856A

CN114302856A - Passenger conveyor

Info

Publication number: CN114302856A
Application number: CN201980099756.7A
Authority: CN
Inventors: 高木雄司; 仲条勇人
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2019-08-29
Filing date: 2019-08-29
Publication date: 2022-04-08
Also published as: WO2021038783A1; JPWO2021038783A1; JP7198359B2

Abstract

The invention provides a passenger conveyor. The inlet portion has an inlet cover, a safety mechanism and a support member. The front face of the inlet cover is inclined with respect to the moving direction of the moving handrail. In addition, an insertion recess is provided in the front face portion. The safety mechanism has: a detection body surrounding a part of the periphery of the movable handrail, having a front end part of the inlet and outlet side partially inserted into the insertion recess and inclined with respect to the moving direction; and a detection switch for detecting the displacement of the detection body. The support member is located between the side wall portion of the insertion recess and the protruding portion of the detection body inserted into the insertion recess, and supports the protruding portion.

Description

Passenger conveyor

Technical Field

The present invention relates to a passenger conveyor provided with a safety mechanism at an entrance portion.

Background

The passenger conveyor includes a frame provided in the building structure, and a plurality of steps that are provided in the frame and are connected in a loop shape and move cyclically. An endless chain is connected to the plurality of steps, and the plurality of steps are cyclically moved by the chain being rotationally driven. Further, a pair of rail portions is provided upright on the frame along the moving direction of the plurality of steps. The rail portion is supported by the cover plate portion. The cover plate portion is provided with an inlet portion for the moving handrail to enter and exit.

As a conventional inlet portion, for example, there is a structure described in patent document 1. Patent document 1 describes a technique including a holding member disposed at the base of a detection body, which is detachable from the detection body, and which operates an inlet switch in a state in which the detection body has entered, and a guide groove provided on the outer peripheral surface of the detection body in parallel with the traveling direction. Further, patent document 1 describes that a guide rail is provided in a lower portion of the balustrade to guide the guide groove.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2012 and 246088

Disclosure of Invention

Technical problem to be solved by the invention

From the viewpoint of design, a passenger conveyor in which the inlet portion is formed to be inclined with respect to the moving direction of the steps when viewed from above has been proposed. However, the technique described in patent document 1 does not consider the case where the inlet portion is formed obliquely, and there is a risk that the detection body is twisted and the safety is lowered.

In view of the above, it is an object of the present invention to provide a passenger conveyor in which an entrance is formed obliquely, and safety can be improved.

Means for solving the problems

In order to solve the above problem, a passenger conveyor is a passenger conveyor having a cover plate portion for supporting a handrail portion, and an inlet portion provided at an end portion in a longitudinal direction of the cover plate portion for allowing a moving handrail of the handrail portion to enter and exit.

The inlet portion has: an inlet cover provided with an insertion recess for the moving handrail to go in and out; a safety mechanism disposed on the inlet cover; and a support member disposed in the insertion recess. The entrance side, i.e. the front side, of the passenger in the entrance cover is inclined with respect to the moving direction of the moving handrail. In addition, an insertion recess is provided in the front face portion. The safety mechanism has: a detection body surrounding a part of the periphery of the movable handrail, having a front end part of the inlet and outlet side partially inserted into the insertion recess and inclined with respect to the moving direction; and a detection switch for detecting the displacement of the detection body. The support member is located between the side wall portion of the insertion recess and the protruding portion of the detection body inserted into the insertion recess, and supports the protruding portion.

In another aspect, an entrance portion of a passenger conveyor includes: an inlet cover provided with an insertion recess for the moving handrail to go in and out; and a safety mechanism disposed in the inlet cover.

The entrance side, i.e. the front side, of the passenger in the entrance cover is inclined with respect to the moving direction of the moving handrail. The front surface portion is provided with an insertion recess. The safety mechanism has: a detection body surrounding a part of the periphery of the movable handrail, having a front end part of the inlet and outlet side partially inserted into the insertion recess and inclined with respect to the moving direction; and a detection switch for detecting the displacement of the detection body. The side wall portion of the insertion recess and a portion of the protruding portion of the detection body inserted into the insertion recess contact each other.

According to the passenger conveyor with the structure, the safety can be improved.

Drawings

Fig. 1 is a schematic configuration diagram showing a configuration example of a passenger conveyor according to an embodiment.

Fig. 2A and 2B show a doorway of a passenger conveyor according to an embodiment, where fig. 2A is a plan view showing an example of the doorway, and fig. 2B is a plan view showing another example of the doorway.

Fig. 3 is a perspective view showing an entrance portion of the passenger conveyor of the embodiment.

Fig. 4 is a front view showing an entrance portion of the passenger conveyor of the embodiment.

Fig. 5 is a plan view of an inlet portion of the passenger conveyor of the embodiment as viewed from an upper side.

Fig. 6 is a sectional view of the inlet cover in the inlet portion of the passenger conveyor of the embodiment sectioned in the horizontal direction.

Fig. 7 is a sectional view of the entrance portion of the passenger conveyor of the embodiment sectioned in the horizontal direction.

Detailed Description

Hereinafter, embodiments of the passenger conveyor will be described with reference to fig. 1 to 7. In addition, the same reference numerals are given to the common components in the drawings.

1. Examples of the embodiments

1-1 structural example of passenger conveyor

First, the structure of a passenger conveyor according to an embodiment (hereinafter referred to as "the present example") will be described with reference to fig. 1 to 2A and 2B.

Fig. 1 is a schematic configuration diagram showing a passenger conveyor. Fig. 2A and 2B are plan views showing the doorway of the passenger conveyor. Fig. 2A and 2B show a state in which the rail portion is removed.

The passenger conveyor 1 shown in fig. 1 is an inclined passenger conveyor, a so-called escalator, provided on an upper floor and a lower floor of a building structure. As shown in fig. 1, the passenger conveyor 1 includes a frame 2 provided in a building structure, an upper landing floor 3A, a lower landing floor 3B, a cover plate portion 4, a plurality of steps 5, and a balustrade portion 7. The passenger conveyor 1 includes a drive mechanism, a lower sprocket 10, and an upper sprocket 11, which are not shown.

The frame 2 is disposed across the upper and lower floors. The frame 2 is composed of an inclined section, an upper horizontal section, and a lower horizontal section. Hereinafter, the direction extending from the lower floor to the upper floor in the frame 2 is referred to as the longitudinal direction of the frame 2. A direction orthogonal to the longitudinal direction of the frame 2 and also orthogonal to the vertical direction is set as the width direction of the frame 2.

An upper horizontal section formed on the upper floor side in the longitudinal direction of the frame 2 is formed parallel to the upper floor. An upper landing floor 3A is provided in an upper horizontal section of the frame 2. The upper landing floor 3A is parallel to the upper floor and is placed on the upper floor.

The lower horizontal section formed on the lower floor side in the longitudinal direction of the frame 2 is formed parallel to the lower floor. A lower landing floor 3B is provided in a lower horizontal section of the frame 2. The lower landing floor 3B is parallel to the lower floor and is disposed on the lower floor.

A drive mechanism and an upper sprocket 11, not shown, are disposed below the upper access floor 3A of the frame 2, and a lower sprocket 10 is disposed below the lower access floor 3B of the frame 2. A transmission chain is wound around the upper sprocket 11 and the drive shaft of the drive mechanism. When the drive mechanism is driven, the upper sprocket 11 is rotationally driven via the transmission chain.

A step chain is wound around the upper sprocket 11 and the lower sprocket 10. The step chain is formed in a ring shape connecting both end portions in the longitudinal direction thereof. By the rotation of the upper sprocket 11, the lower sprocket 10 and the step chain rotate. The step chain circulates between the upper sprocket 11 and the lower sprocket 10.

A plurality of steps 5 are connected to the step chain in an endless manner. The plurality of steps 5 are movably supported by a guide rail, not shown, provided in the frame 2. Then, the plurality of steps 5 circulate along the guide rail between the upper sprocket 11 and the lower sprocket 10.

As shown in fig. 2A, cover plates 4 are provided at both ends of the plurality of steps 5 in the width direction. As shown in fig. 1, the cover plate 4 is disposed along the longitudinal direction of the frame 2. The cover plate 4 covers all the upper inclined sections and parts of the upper horizontal section and the lower horizontal section of both ends in the width direction of the frame 2.

The balustrade portion 7 has a balustrade panel 6 supported by the cover portion 4 and a moving handrail 8. The moving handrail 8 is movably supported by the peripheral edge portion of the balustrade panel 6. The moving handrail 8 is moved cyclically in synchronization with the cyclic operation of the plurality of steps 5. The movable handrail 8 moves in and out of the inlet 20 provided in the cover plate 4.

1-2 inlet part structure

Next, the detailed structure of the inlet 20 will be described with reference to fig. 2A to 7.

Fig. 3 is a perspective view showing the inlet portion 20, fig. 4 is a front view showing the inlet portion 20, and fig. 5 is a plan view of the inlet portion as viewed from above.

As shown in fig. 2A, the inlet 20 is provided at both longitudinal ends of the cover 4, that is, at the front end of the cover 4. As shown in fig. 3 to 7, the inlet portion 20 includes an inlet cover 21, a safety mechanism 50, and a support member 60.

As shown in fig. 2A, a front portion 21c inclined with respect to the moving direction of the steps 5 and the moving handrail 8 (see fig. 5) is provided at the entrance side, that is, the front end portion of the entrance cover 21. In addition, one end portion on the inner side, which is the other inlet cover 21 side facing in the width direction, of the front surface portion 21c of the inlet cover 21 shown in fig. 2A is closer to the cover plate portion 4 than the other end portion on the outer side. Thereby, the doorway of the passenger conveyor 1 is formed in a shape that faces the passenger toward the step 5. As a result, it is possible to make it easy for passengers to enter the passenger conveyor 1.

The direction of inclination of the inlet cover 21 is not limited to the example shown in fig. 2A, and the other end portion on the outer side of the front surface portion 21c may be inclined so as to be closer to the cover plate portion 4 than the one end portion on the inner side, as shown in the inlet cover 21B shown in fig. 2B.

Further, the front portions of the 2 inlet covers disposed on both sides in the width direction of the passenger conveyor 1 may be inclined in the same direction in a substantially parallel manner.

As shown in fig. 3 and 4, an insertion recess 22 into which the movable handrail 8 is inserted is formed in the front surface portion 21c of the inlet cover 21.

Fig. 6 is a sectional view of the inlet cover 21 taken in the horizontal direction.

As shown in fig. 6, the insertion recess 22 is formed in a substantially cylindrical shape. The insertion recess 22 has a front side open end 22c on the front surface portion 21c side and an inner side open end 22d on the opposite side of the front side open end 22 c. The front-side open end 22c is inclined with respect to the moving direction of the steps 5 and the moving handrail 8, as in the front portion 21 c.

The insertion recess 22 includes a first side wall 22a and a second side wall 22b opposite to the first side wall 22 a. The first side wall portion 22A and the second side wall portion 22B extend from the front side opening end portion 22c substantially in parallel with the moving direction of the step 5 (refer to fig. 1 and 2A and 2B). In addition, the length from the front-side open end 22c to the inner open end 22d of the first side wall 22a is set to be longer than the length from the front-side open end 22c to the inner open end 22d of the second side wall 22b in accordance with the inclination of the front portion 21 c.

Fig. 7 is a sectional view of the inlet portion 20 sectioned in the horizontal direction.

As shown in fig. 7, the safety mechanism 50 includes a detection body 30 and a detection switch 40 that detects the displacement of the detection body 30.

The detection body 30 has a main body 31 and a protruding portion 32. The detection body 30 is formed in a cylindrical shape. Further, a continuous notch 33 is formed in the side surface of the detection body 30 along the axial direction of the detection body 30 from the main body 31 to a tip 36 of the protrusion 32, which will be described later. Therefore, the cross-sectional shape of the detection body 30 cut in the vertical direction is substantially C-shaped. The movable armrest 8 can be inserted into the cylindrical hole of the detection body 30 through the notch 33. Thereby, the detection body 30 surrounds a part of the periphery of the moving handrail 8.

Further, the detection body 30 is disposed in the entrance portion 20 and is supported by a not-shown bracket so as to be movable along the moving direction of the moving handrail 8. As shown in fig. 4 and 7, the body 31 is disposed in the inlet cover 21 at a position facing the opening of the insertion recess 22 on the inner opening end 22d side. The main body 31 is supported by a bracket, not shown.

The protruding portion 32 protrudes from the main body portion 31 in the moving direction of the moving handrail 8. The protruding portion 32 is inserted into the insertion recess 22 provided in the inlet cover 21. The front end 36 of the protruding portion 32 on the side opposite to the body portion 31 is inclined with respect to the moving direction of the steps 5 and the moving handrail 8, similarly to the front portion 21c and the front-side opening end 22c of the insertion recess 22.

The protruding portion 32 has a first side surface portion 34 facing the first side wall portion 22a of the insertion recess 22 and a second side surface portion 35 facing the second side wall portion 22 b. The length of the first side surface portion 34 from the body portion 31 to the distal end portion 36 is set longer than the length of the second side surface portion 35 from the body portion 31 to the distal end portion 36.

When a hand or a foreign object intrudes into the insertion recess 22, the protrusion 32 is pushed by the hand or the foreign object. Then, the detection body 30 is displaced toward the inside of the inlet cover 21. The detection body 30 is formed of a member having a spring force to such an extent that foreign matter entering the insertion recess 22 is not damaged and having rigidity that enables external force to be reliably transmitted to the detection switch 40 described later. The detection body 30 is formed of rubber or the like, for example.

The detection switch 40 is supported by a bracket, not shown, and is disposed inside the inlet cover 21 and the cover plate 4. The detection switch 40 is pressed by the holder supporting the detection body 30 or the main body 31 of the detection body 30 when the detection body 30 is displaced. Thereby, the detection switch 40 detects the displacement of the detection body 30 and the intrusion of the foreign matter into the inlet portion 20. The detection switch 40 outputs a detection signal to a control unit, not shown. The control unit determines that there is an abnormality based on the detection signal from the detection switch 40, and stops the operation of the passenger conveyor 1 or notifies a management center or the like of the abnormality signal.

As shown in fig. 4 and 7, a gap is formed between the first side wall portion 22a of the insertion recess 22 and the first side surface portion 34 of the protrusion 32. Further, the first side surface portion 34 is formed longer than the second side surface portion 35, and therefore easily bends by an external force. Therefore, as shown in fig. 7, when an external force F1 is applied to the front end portion 36 of the protruding portion 32 from the direction orthogonal to the moving direction of the steps 5 and the moving handrail 8, there is a risk that the protruding portion 32 twists toward the first side wall portion 22a as shown by a two-dot chain line G1 shown in fig. 7.

Further, the length of the gap between the first side surface portion 34 and the first side wall portion 22a from the front side open end 22c to the inner side open end 22d is increased. As a result, when foreign matter is caught in the gap between the first side surface portion 34 and the first side wall portion 22a, the distance by which the foreign matter is drawn into the insertion recess 22 becomes long, and the foreign matter may be difficult to be drawn out.

In contrast, the inlet portion 20 of this example includes the support member 60. The support member 60 is mounted on the first side wall portion 22a inserted into the recess 22. The support member 60 is located between the first side wall portion 22a and the first side surface portion 34. That is, the support member 60 is disposed at a position where the length of the step 5 and the moving handrail 8 in the moving direction inserted into the recess 22 and the protrusion 32 is longest.

In addition, the support member 60 extends in the insertion recess 22 along the moving direction of the steps 5 and the moving handrail 8. This allows the gap formed between the first side wall 22a and the first side surface 34 to be filled with the support member 60. The support member 60 supports the first side surface portion 34 of the protrusion 32.

The protruding portion 32 is supported by the support member 60, and thus when an external force F1 is applied to the protruding portion 32 from a direction orthogonal to the moving direction of the steps 5 and the moving handrail 8, the protruding portion 32 can be prevented from twisting toward the first side wall portion 22 a. Thus, the external force F1 is dispersed in a direction parallel to the moving direction of the steps 5 and the moving handrail 8 due to the inclination of the front end portion 36 of the detection body 30. Then, the detection body 30 is displaced toward the inside of the inlet cover 21, and the detection switch 40 can be pressed by the main body 31 or the holder supporting the detection body 30. This can improve the safety of the passenger conveyor 1.

Further, the support member 60 can prevent foreign matter from entering between the first side surface portion 34 and the first side wall portion 22 a. As a result, the foreign matter can be prevented from being drawn into the gap between the detection body 30 and the insertion recess 22, and the safety of the passenger conveyor 1 can be improved.

As the support member 60, a member having a low friction coefficient is preferably used in order to suppress the influence on the displacement of the detection body 30 in the movement direction of the steps 5 and the moving handrail 8. As the support member 60, for example, a material such as resin or metal having a surface subjected to friction reduction treatment is used.

Although a gap is also formed between the second side wall portion 22b and the second side surface portion 35, the projecting portion 32 is less likely to be twisted toward the second side wall portion 22b by the external force F1. Further, the lengths of the second side wall portion 22b and the second side surface portion 35 from the front-side open end portion 22c to the inner open end portion 22d of the insertion recess 22 are short, and foreign matter or the like is less likely to enter the gap between the second side wall portion 22b and the second side surface portion 35. Therefore, even if the support member 60 is not provided between the second side wall portion 22b and the second side surface portion 35, the twisting of the detection body 30 or the operation of the detection body 30 is not affected.

When an external force is applied to the protruding portion 32 from above or below in the vertical direction, the protruding portion 32 comes into contact with the moving handrail 8. The detection body 30 is displaced toward the inside of the inlet cover 21 together with the moving handrail 8, and therefore the detection switch 40 can be reliably pressed. Therefore, the support member 60 may not be provided in the gap between the protrusion 32 and the upper and lower portions in the vertical direction in the insertion recess 22.

The support member 60 may be provided in a gap between the second side wall portion 22b and the second side surface portion 35, or in a gap between the protrusion portion 32 and a lower portion and an upper portion in the vertical direction in the insertion recess portion 22.

The present invention is not limited to the embodiments described above and shown in the drawings, and can be variously modified and implemented without departing from the scope of the present invention.

In the above embodiment, the example in which the support member 60 is attached to the first side wall portion 22a of the insertion recess 22 has been described, but the present invention is not limited thereto, and the support member 60 may be attached to the first side surface portion 34 of the protruding portion 32.

In the above embodiment, the example in which the gap is provided between the first side surface portion 34 of the protruding portion 32 and the first side wall portion 22a of the insertion recess 22 and the supporting member 60 filling the gap is disposed has been described, but the present invention is not limited to this.

For example, the first side surface portion 34 may be disposed so as to be in contact with the first side wall portion 22a or so as to provide a small gap to such an extent that foreign matter does not enter. The thickness of the protruding portion 32 on the first side surface portion 34 side may be designed to be thick so that the first side surface portion 34 contacts the first side wall portion 22a or a small gap is provided to such an extent that foreign matter does not enter. Thereby, the first side surface portion 34 of the protruding portion 32 is supported by the first side wall portion 22a of the insertion recess 22.

With this configuration, twisting of the detection body 30 and intrusion of foreign matter between the first side surface portion 34 and the first side wall portion 22a can be prevented. Further, since the member for supporting the protruding portion 32 is not required, the number of components can be reduced.

In addition, when the gap between the first side surface portion 34 and the first side wall portion 22a is eliminated without using the support member 60, there is a risk that the detection body 30 and the insertion recess 22 interfere with the moving handrail 8 depending on the dimensional tolerance and the degree of installation of the passenger conveyor 1 in the building structure. Therefore, there is a problem that not only the dimensional accuracy required for the detection body 30 and the inlet cover 21 is improved, but also the operation of installing the detection body 30 becomes complicated.

Accordingly, as in the above-described embodiment, by providing the gap between the first side surface portion 34 and the first side wall portion 22a and disposing the support member 60 in the gap, an adjustment margin can be secured, and the installation work of the inlet cover 21 and the detection body 30 can be easily performed. Further, the dimensional accuracy required for the inlet cover 21 and the detection body 30 can be kept low.

In the above embodiment, the description has been given by taking an escalator in which steps have a height difference between steps as an example of an inclined passenger conveyor, but the passenger conveyor of the present invention can be applied to a moving road having a plurality of steps in which a height difference does not occur between steps, that is, a so-called moving walkway.

Further, the present invention can also be applied to a passenger conveyor having a frame in which a portion parallel to the upper horizontal section and the lower horizontal section is provided in at least a part of the inclined section. Further, the present invention can be similarly applied to a passenger conveyor having a frame in which the extending direction of the inclined section changes in a curved manner and the extending direction of the upper horizontal section and the lower horizontal section are different from each other.

In the present specification, terms such as "parallel" and "orthogonal" are used, but these terms do not mean only strict "parallel" and "orthogonal", and may include "substantially parallel" and "orthogonal" in a range in which the terms can function, and "substantially parallel" and "substantially orthogonal".

Description of the reference numerals

1 … … passenger conveyor, 2 … … frame, 3a … … upper landing floor, 3B … … lower landing floor, 4 … … cover plate, 5 … … step, 6 … … railing plate, 7 … … rod, 8 … … moving handrail, 20 … … entrance, 21B … … entrance cover, 21c … … front face, 22 … … insertion recess, 22a … … first side wall, 22B … … second side wall, 22c … … front face side opening end, 22d … … inner side opening end, 30 … … detector, 31 … … main body, 32 … … protrusion, 33 … … notch, 34 … … first side face, 35 … … second side face, 36 39 36 … … front end, 40 … … detection switch, 50 … … safety mechanism, 60 … … support component.

Claims

1. A passenger conveyor having: a cover plate portion for supporting the rail portion; and an entrance portion provided at an end portion of the cover plate portion in a longitudinal direction thereof, through which the movable handrail of the balustrade portion enters and exits, the passenger conveyor being characterized in that:

the inlet portion has:

an inlet cover provided with an insertion recess for the movable handrail to enter and exit;

a safety mechanism disposed on the inlet cover; and

a support member disposed in the insertion recess portion,

a front portion of the inlet cover on a passenger entrance side is inclined with respect to a moving direction of the moving handrail and is provided with the insertion recess,

the safety mechanism has:

a detection body which surrounds a part of the periphery of the movable armrest, a part of the detection body is inserted into the insertion concave part, and the front end part of the outlet side is inclined relative to the moving direction; and

a detection switch for detecting the displacement of the detection body,

the support member is located between a side wall portion of the insertion recess and a protruding portion of the detection body inserted into the insertion recess, and supports the protruding portion.

2. The passenger conveyor of claim 1, wherein:

the support member is disposed at a position where the length of the side wall portion and the protruding portion in the moving direction is longest.

3. The passenger conveyor of claim 1, wherein:

the support member is attached to the side wall portion or the protruding portion.

4. The passenger conveyor of claim 1, wherein:

the insertion recess has:

a front-side opening end portion as an opening end on the front side;

an inner open end portion which is an open end opposite to the front-side open end portion;

a first side wall portion extending from the front-side open end portion toward the inner-side open end portion; and

a second side wall portion that is opposite to the first side wall portion and extends from the front-side open end portion toward the inner-side open end portion,

a length of the first side wall portion from the front side opening end portion to the inside side opening end portion is set larger than a length of the second side wall portion from the front side opening end portion to the inside side opening end portion,

the detection body has a main body portion facing the inner-side opening end portion, the protruding portion protruding from the main body portion,

the protruding portion has:

a first side surface portion opposing the first side wall portion; and

a second side surface portion opposed to the second side wall portion,

a length of the first side surface portion from the main body portion to the front end portion is set to be greater than a length of the second side surface portion from the main body portion to the front end portion,

the support member is disposed between the first side surface portion and the first side wall portion.

5. The passenger conveyor of claim 4, wherein:

the main body portion is supported inside the inlet cover or the cover plate portion so as to be movable in the moving direction.

6. The passenger conveyor of claim 4, wherein:

the support member is attached to the first side wall portion.

7. The passenger conveyor of claim 4, wherein:

the detection body has a continuous notch formed from the distal end portion to the main body portion.

8. A passenger conveyor having: a cover plate portion for supporting the rail portion; and an entrance portion provided at an end portion of the cover plate portion in a longitudinal direction thereof, through which the movable handrail of the balustrade portion enters and exits, the passenger conveyor being characterized in that:

the inlet portion has:

an inlet cover provided with an insertion recess for the movable handrail to enter and exit; and

a safety mechanism disposed on the inlet cover,

the safety mechanism has:

a detection switch for detecting the displacement of the detection body,

the side wall portion of the insertion recess and a part of the protruding portion of the detection body inserted into the insertion recess are in contact with each other.

9. The passenger conveyor of claim 1 or 8, wherein:

the front surface portion is inclined in a direction in which one end portion on an inner side in a width direction orthogonal to the moving direction is closer to the cover plate portion than the other end portion on an outer side.