WO2021038783A1

WO2021038783A1 - Passenger conveyor

Info

Publication number: WO2021038783A1
Application number: PCT/JP2019/033874
Authority: WO
Inventors: 雄司高木; 勇人仲條
Original assignee: 株式会社日立製作所
Priority date: 2019-08-29
Filing date: 2019-08-29
Publication date: 2021-03-04
Also published as: CN114302856A; JPWO2021038783A1; JP7198359B2

Abstract

An inlet section has an inlet cover, a safety mechanism, and a support member. The front face of the inlet cover is slanted with respect to the direction of motion of a moving handrail. In addition, an insertion recess is provided in the front face. The safety mechanism has: a detection body that encloses a portion of the circumference of the moving handrail, with a portion of the detection body being inserted in the insertion recess, and that has a leading end on the entrance/exit side slanted with respect to the direction of motion; and a detection switch that detects displacement of the detection body. The support member is interposed between a side wall of the insertion recess and a projection of the detection body inserted into the insertion recess and supports the projection.

Description

Passenger conveyor

The present invention relates to a passenger conveyor provided with a safety mechanism in the inlet portion.

The passenger conveyor is provided with a frame installed in a building structure and a plurality of steps provided in the frame and connected in an endless manner for circulating movement. An endless chain is connected to the plurality of steps, and the plurality of steps circulate and move by rotationally driving the chain. Further, a pair of balustrades are erected on the frame along the moving directions of the plurality of steps. This balustrade section is supported by the deck section. The deck portion is provided with an inlet portion through which the moving handrail of the balustrade portion enters and exits.

As a conventional inlet portion, for example, there is one described in Patent Document 1. Patent Document 1 describes a holding member that is arranged at the base of the detector and is detachable from the detector and operates an inlet switch with the detector intruded, and a traveling direction on the outer peripheral surface of the detector. Techniques are described that include guide grooves provided in parallel. Further, Patent Document 1 describes that it has a guide rail provided inside the lower part of the balustrade and guides the guide groove.

Japanese Unexamined Patent Publication No. 2012-246088

Also, from the viewpoint of design, a passenger conveyor has been proposed in which the inlet portion is formed diagonally with respect to the moving direction of the step when viewed from above. However, in the technique described in Patent Document 1, the formation of the inlet portion at an angle is not considered, and the detector may be twisted and the safety may be lowered.

In consideration of the above problems, it is an object of the present invention to provide a passenger conveyor capable of improving safety in a passenger conveyor having an inlet portion formed diagonally.

In order to solve the above problems, the passenger conveyor is a passenger conveyor provided with a deck portion that supports the balustrade portion and an inlet portion that is provided at the end of the deck portion in the longitudinal direction and in which the moving handrail of the balustrade portion enters and exits. is there.
The inlet portion has an inlet cover provided with an insertion recess for entering and exiting the moving handrail, a safety mechanism arranged in the inlet cover, and a support member arranged in the insertion recess. The front portion of the inlet cover on the entrance / exit side of passengers is inclined with respect to the moving direction of the moving handrail. Further, an insertion recess is provided in the front portion. The safety mechanism includes a detector that surrounds a part around the moving handrail and a part is inserted into the insertion recess, and the tip on the doorway side is tilted with respect to the moving direction, and a detection switch that detects the displacement of the detector. ,have. The support member is interposed between the side wall portion of the insertion recess and the protrusion inserted into the insertion recess in the detection body to support the protrusion.

Further, the inlet portion of another passenger conveyor has an inlet cover provided with an insertion recess for entering and exiting a moving handrail, and a safety mechanism arranged on the inlet cover.
The front portion of the inlet cover on the entrance / exit side of passengers is inclined with respect to the moving direction of the moving handrail. An insertion recess is provided on the front surface. The safety mechanism includes a detector that surrounds a part around the moving handrail and a part is inserted into the insertion recess, and the tip on the doorway side is tilted with respect to the moving direction, and a detection switch that detects the displacement of the detector. ,have. Then, the side wall portion of the insertion recess and a part of the protrusion inserted into the insertion recess in the detection body come into contact with each other.

According to the passenger conveyor having the above configuration, safety can be improved.

It is a schematic block diagram which shows the structural example of the passenger conveyor which concerns on the Example of Embodiment. The entrance / exit of the passenger conveyor according to the embodiment is shown, FIG. 2A is a plan view showing an example of the entrance / exit, and FIG. 2B is a plan view showing another example of the entrance / exit. It is a perspective view which shows the inlet part of the passenger conveyor which concerns on the Example of Embodiment. It is a front view which shows the inlet part of the passenger conveyor which concerns on the Example of Embodiment. It is a top view of the inlet part of the passenger conveyor which concerns on embodiment. It is sectional drawing which cut in the horizontal direction the inlet cover in the inlet part of the passenger conveyor which concerns on embodiment. It is sectional drawing which cut the inlet part of the passenger conveyor which concerns on Example of Embodiment in a horizontal direction.

Hereinafter, an example of the embodiment of the passenger conveyor will be described with reference to FIGS. 1 to 7. The common members in each figure are designated by the same reference numerals.

1. 1. Example 1-1. Configuration Example of Passenger Conveyor First, the configuration of the passenger conveyor according to the embodiment (hereinafter referred to as “this example”) will be described with reference to FIGS. 1 to 2A and 2B.
FIG. 1 is a schematic configuration diagram showing a passenger conveyor. 2A and 2B are plan views showing the entrance and exit of the passenger conveyor. In addition, FIG. 2A and FIG. 2B show a state in which the balustrade portion is removed.

The passenger conveyor 1 shown in FIG. 1 is a so-called escalator, which is an inclined passenger conveyor installed on the upper floor and the lower floor of a building structure. As shown in FIG. 1, the passenger conveyor 1 includes a frame 2 installed in a building structure, an upper boarding / alighting floor 3A, a lower boarding / alighting floor 3B, a deck portion 4, a plurality of steps 5, and a balustrade portion 7. , Is equipped. Further, the passenger conveyor 1 includes a drive mechanism (not shown), a lower sprocket 10, and an upper sprocket 11.

Frame 2 is installed across the upper floor and the lower floor. 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. The width direction of the frame 2 is defined as a direction orthogonal to the longitudinal direction of the frame 2 and also orthogonal to the vertical direction.

The 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 floor 3A is installed in the upper horizontal section of the frame 2. The upper 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 floor 3B is installed in the lower horizontal section of the frame 2. The lower floor 3B is parallel to the lower floor and is installed on the lower floor.

Further, a drive mechanism (not shown) and an upper sprocket 11 are arranged below the upper floor 3A in the frame 2, and a lower sprocket 10 is arranged below the lower floor 3B in 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 an endless shape in which both ends in the longitudinal direction are connected. The rotation of the upper sprocket 11 causes the lower sprocket 10 and the step chain to rotate. Then, 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 guide rails (not shown) provided on the frame 2. As a result, the plurality of steps 5 circulate between the upper sprocket 11 and the lower sprocket 10 along the guide rail.

As shown in FIG. 2A, deck portions 4 are installed at both ends of the plurality of steps 5 in the width direction. As shown in FIG. 1, the deck portion 4 is arranged along the longitudinal direction of the frame 2. The deck portion 4 covers all of the inclined sections above both ends of the frame 2 in the width direction, and a part of the upper horizontal section and the lower horizontal section.

The balustrade portion 7 has a balustrade panel 6 supported by the deck portion 4 and a moving handrail 8. The moving handrail 8 is movably supported on the peripheral edge of the balustrade panel 6. Further, the moving handrail 8 circulates in synchronization with the circulation operation of the plurality of steps 5. Then, the moving handrail 8 goes in and out of the inlet portion 20 provided in the deck portion 4.

1-2. Configuration of Inlet Division Next, a detailed configuration of the inlet portion 20 will be described with reference to FIGS. 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 portion 20 is provided at both ends of the deck portion 4 in the longitudinal direction, that is, at the tip end portion of the so-called deck portion 4. As shown in FIGS. 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, the tip portion of the inlet cover 21 on the entrance / exit side is provided with a front portion 21c inclined with respect to the moving direction of the step 5 and the moving handrail 8 (see FIG. 5). The inner end portion of the front portion 21c of the inlet cover 21 shown in FIG. 2A on the side of the other inlet cover 21 facing in the width direction is closer to the deck portion 4 than the outer other end portion. As a result, the entrance / exit of the passenger conveyor 1 is formed so as to allow passengers to face the step 5. As a result, passengers can easily 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 as in the inlet cover 21B shown in FIG. 2B, the outer other end of the front portion 21c is from the inner one end. May be tilted so as to approach the deck portion 4.

Further, the front portions of the two inlet covers arranged on both sides in the width direction of the passenger conveyor 1 may be inclined in the same direction so as to be substantially parallel to each other.

As shown in FIGS. 3 and 4, the front portion 21c of the inlet cover 21 is formed with an insertion recess 22 into which the moving handrail 8 enters and exits.

FIG. 6 is a cross-sectional view of the inlet cover 21 cut in the horizontal direction.
As shown in FIG. 6, the insertion recess 22 is formed in a substantially tubular shape. The insertion recess 22 has an opening end 22c on the front side on the front side 21c side and an inner opening end 22d on the opposite side of the opening end 22c on the front side. The front side opening end portion 22c is inclined with respect to the moving direction of the step 5 and the moving handrail 8 as in the front portion 21c.

Further, the insertion recess 22 has a first side wall portion 22a and a second side wall portion 22b facing the first side wall portion 22a. The first side wall portion 22a and the second side wall portion 22b extend substantially parallel to the moving direction of the step 5 (see FIGS. 1 and 2) from the front side opening end portion 22c. Further, in correspondence with the inclination of the front side wall portion 21c, the length from the front side opening end portion 22c to the inside opening end portion 22d in the first side wall portion 22a is from the front side opening end portion 22c in the second side wall portion 22b to the inside. It is set longer than the length up to the opening end 22d.

FIG. 7 is a cross-sectional view of the inlet portion 20 cut 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 detector 30 has a main body 31 and a protruding portion 32. The detector 30 is formed in a tubular shape. Further, a continuous notch 33 is formed in the side surface portion of the detection body 30 from the main body portion 31 to the tip portion 36 of the protrusion 32, which will be described later, along the axial direction of the detection body 30. Therefore, the detection body 30 has a substantially C-shaped cross-sectional shape cut in the vertical direction. Further, the moving handrail 8 can be inserted into the tubular hole of the detection body 30 from the notch 33. As a result, the detector 30 surrounds a part of the periphery of the moving handrail 8.

Further, the detector 30 is arranged in the inlet portion 20 and is movably supported along the moving direction of the moving handrail 8 by a bracket (not shown). As shown in FIGS. 4 and 7, the main body 31 is arranged in the inlet cover 21 at a position facing the opening on the inner opening end 22d side of the insertion recess 22. The main body 31 is supported by a bracket (not shown).

The protruding portion 32 protrudes from the main body portion 31 along the moving direction of the moving handrail 8. Then, the protruding portion 32 is inserted into the insertion recess 22 provided in the inlet cover 21. The tip 36 of the protruding portion 32 on the opposite side of the main body 31 is inclined with respect to the moving direction of the step 5 and the moving handrail 8 in the same manner as the front opening end 22c of the front portion 21c and the insertion recess 22. There is.

Further, 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 22b. The length of the first side surface portion 34 from the main body portion 31 to the tip portion 36 is set longer than the length of the second side surface portion 35 from the main body portion 31 to the tip portion 36.

Then, when a hand or a foreign substance enters the insertion recess 22, the protruding portion 32 is pressed by the hand or the foreign substance. Then, the detector 30 is displaced toward the inside of the inlet cover 21. The detection body 30 is formed of a member having elasticity enough not to damage foreign matter that has entered the insertion recess 22 and rigidity capable of reliably transmitting an external force to the detection switch 40 described later. The detector 30 is formed of, for example, rubber or the like.

The detection switch 40 is supported by a bracket (not shown) and is arranged inside the inlet cover 21 and the deck portion 4. When the detection body 30 is displaced, the detection switch 40 is pressed by a bracket that supports the detection body 30 or a main body 31 of the detection body 30. As a result, the detection switch 40 detects the displacement of the detection body 30 and detects the intrusion of foreign matter into the inlet portion 20. Further, the detection switch 40 outputs a detection signal to a control unit (not shown). Then, the control unit determines an abnormality based on the detection signal from the detection switch 40, stops the operation of the passenger conveyor 1, or notifies the management center or the like of the abnormality signal.

Further, as shown in FIGS. 4 and 7, a gap is generated between the first side wall portion 22a of the insertion recess 22 and the first side surface portion 34 of the protrusion 32. Further, since the first side surface portion 34 is formed longer than the second side surface portion 35, it is easily bent by an external force. Therefore, as shown in FIG. 7, when an external force F1 is applied to the tip 36 of the protruding portion 32 from a direction orthogonal to the moving direction of the step 5 and the moving handrail 8, the protruding portion 32 has two points shown in FIG. Like the chain wire G1, there is a risk of twisting toward the first side wall portion 22a.

Further, the length from the front side opening end 22c to the inner opening end 22d in the gap between the first side surface portion 34 and the first side wall portion 22a becomes longer. As a result, when a foreign matter is caught in the gap between the first side surface portion 34 and the first side wall portion 22a, the distance drawn into the insertion recess 22 becomes long, and the foreign matter may not easily come out.

On the other hand, the inlet portion 20 of this example has a support member 60. The support member 60 is attached to the first side wall portion 22a in the insertion recess 22. The support member 60 is interposed between the first side wall portion 22a and the first side surface portion 34. That is, the support member 60 is arranged at a position where the length of the step 5 and the moving handrail 8 in the moving direction is the longest in the insertion recess 22 and the protruding portion 32.

Further, the support member 60 extends in the insertion recess 22 along the moving direction of the step 5 and the moving handrail 8. As a result, the gap formed between the first side wall portion 22a and the first side surface portion 34 can be filled with the support member 60. Then, the support member 60 supports the first side surface portion 34 of the protruding portion 32.

Since the protruding portion 32 is supported by the support member 60, when an external force F1 is applied to the protruding portion 32 from a direction orthogonal to the moving direction of the step 5 and the moving handrail 8, the protruding portion 32 is on the first side wall portion 22a side. It can be prevented from twisting. As a result, the external force F1 is dispersed in the direction parallel to the moving direction of the step 5 and the moving handrail 8 due to the inclination of the tip 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 bracket supporting the detection body 30. Thereby, the safety of the passenger conveyor 1 can be enhanced.

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

As the support member 60, it is preferable to use a member having a low friction coefficient in order to suppress the influence of the step 5 and the moving handrail 8 on the displacement of the detection body 30 in the moving direction. As the support member 60, for example, a material such as resin or a metal whose surface has been subjected to friction reduction treatment is applied.

Although a gap is also generated between the second side wall portion 22b and the second side surface portion 35, the protruding portion 32 is unlikely to be twisted toward the second side wall portion 22b by the external force F1. Further, the length from the front side opening end 22c to the inner opening end 22d of the insertion recess 22 in the second side wall portion 22b and the second side surface portion 35 is short, and foreign matter or the like is contained in the second side wall portion 22b and the second side surface portion. It is difficult to get into the gap between 35 and 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 twist of the detection body 30 and the operation of the detection body 30 are not affected.

Further, 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. Then, since the detection body 30 is displaced toward the inside of the inlet cover 21 together with the moving handrail 8, the detection switch 40 can be reliably pressed. Therefore, it is not necessary to provide the support member 60 in the gap between the upper portion and the lower portion in the vertical direction between the protrusion 32 and the insertion recess 22.

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

It should be noted that the present invention is not limited to the embodiment described above and shown in the drawings, and various modifications can be carried out within a range that does not deviate from the gist of the invention described in the claims.

In the above-described embodiment, the support member 60 is attached to the first side wall portion 22a of the insertion recess 22, but the present invention is not limited to this, and the support member 60 is supported by the first side surface portion 34 of the protrusion 32. The member 60 may be attached.

In the above-described embodiment, a gap is provided between the first side surface portion 34 of the protrusion 32 and the first side wall portion 22a of the insertion recess 22, and a support member 60 for filling the gap is provided. , Not limited to this.

For example, the first side surface portion 34 may be arranged so that the first side surface portion 34 and the first side wall portion 22a are in contact with each other, or a small gap is provided so that foreign matter does not enter. Further, even if the thickness of the protruding portion 32 on the first side surface portion 34 side is designed to be thick so that the first side surface portion 34 comes into contact with the first side wall portion 22a or a small gap is provided so that foreign matter does not enter. Good. As a result, the first side surface portion 34 of the protrusion 32 is supported by the first side wall portion 22a of the insertion recess 22.

Even with such a configuration, it is possible to prevent the detection body 30 from being twisted and foreign matter from entering between the first side surface portion 34 and the first side wall portion 22a. Further, since it is not necessary to provide a member for supporting the protruding portion 32, the number of parts can be reduced.

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, the detector 30 or the insertion body 30 is inserted depending on the dimensional tolerance and the degree to which the passenger conveyor 1 is installed in the building structure. The recess 22 may interfere with the moving handrail 8. Therefore, not only the dimensional accuracy required for the detector 30 and the inlet cover 21 is improved, but also the work of installing the detector 30 may become complicated.

Therefore, as in the above-described embodiment, a gap is provided between the first side surface portion 34 and the first side wall portion 22a, and the support member 60 is arranged in this gap to secure the adjustment allowance. Therefore, the installation work of the inlet cover 21 and the detector 30 can be easily performed. Further, the dimensional accuracy required for the inlet cover 21 and the detector 30 can be suppressed low.

In the above-described embodiment, the escalator having a step between the steps has been described as an example of the inclined passenger conveyor, but the passenger conveyor of the present invention has a plurality of steps having no step between the steps. It can also be applied to an electric road that has a so-called moving walkway.

It can also be applied to a passenger conveyor having a frame in which at least a part of the inclined section is provided with a portion parallel to the upper horizontal section and the lower horizontal section. Further, since the extension direction of the inclined section is curved and changed, the same can be applied to a passenger conveyor having a frame in which the extension directions of the upper horizontal section and the lower horizontal section are different.

Although words such as "parallel" and "orthogonal" have been used in the present specification, these do not mean only strict "parallel" and "orthogonal", but include "parallel" and "orthogonal". Further, it may be in a "substantially parallel" or "substantially orthogonal" state within a range in which the function can be exhibited.

1 ... Passenger conveyor, 2 ... Frame, 3A ... Upper boarding / alighting, 3B ... Lower boarding / alighting, 4 ... Deck section, 5 ... Steps, 6 ... Banquet panel, 7 ... Column section, 8 ... Moving handrail, 20 ... Inlet section, 21, 21B ... inlet cover, 21c ... front part, 22 ... insertion recess, 22a ... first side wall part, 22b ... second side wall part, 22c ... front side opening end, 22d ... inside opening end, 30 ... detector , 31 ... Main body, 32 ... Protruding, 33 ... Notch, 34 ... First side surface, 35 ... Second side surface, 36 ... Tip, 40 ... Detection switch, 50 ... Safety mechanism, 60 ... Support member

Claims

In a passenger conveyor provided with a deck portion that supports the balustrade portion and an inlet portion that is provided at an end portion of the deck portion in the longitudinal direction and in which a moving handrail of the balustrade portion enters and exits.
The inlet portion is
An inlet cover provided with an insertion recess for the moving handrail to enter and exit,
The safety mechanism arranged on the inlet cover and
It has a support member arranged in the insertion recess and
The front portion of the inlet cover on the passenger entrance / exit side is inclined with respect to the moving direction of the moving handrail, and the insertion recess is provided.
The safety mechanism
A detector that surrounds a part of the circumference of the moving handrail, a part of which is inserted into the insertion recess, and the tip of the doorway is inclined with respect to the moving direction.
It has a detection switch that detects the displacement of the detector, and
The support member is a passenger conveyor that supports the protrusion by being interposed between the side wall of the insertion recess and the protrusion inserted into the insertion recess in the detector.
The passenger conveyor according to claim 1, wherein the support member is arranged at a position where the length in the moving direction is the longest in the side wall portion and the protruding portion.
The passenger conveyor according to claim 1, wherein the support member is attached to the side wall portion or the protruding portion.
The insertion recess is
The front side opening end, which is the front side opening end,
The inner opening end, which is the opening on the opposite side of the front opening,
A first side wall portion extending from the front side opening end portion toward the inner opening end portion,
It has a second side wall portion that faces the first side wall portion and extends from the front side opening end portion toward the inner opening end portion.
The length from the front side opening end portion to the inner opening end portion in the first side wall portion is set to be longer than the length from the front side opening end portion to the inner opening end portion in the second side wall portion. ,
The detector has a main body that faces the inner open end and the protrusion protrudes.
The protrusion is
A first side surface portion facing the first side wall portion and
It has a second side surface portion facing the second side wall portion, and has.
The length from the main body portion to the tip portion on the first side surface portion is set to be longer than the length from the main body portion to the tip portion on the second side surface portion.
The passenger conveyor according to claim 1, wherein the support member is arranged between the first side surface portion and the first side wall portion.
The passenger conveyor according to claim 4, wherein the main body portion is supported so as to be movable along the moving direction inside the inlet cover or the deck portion.
The passenger conveyor according to claim 4, wherein the support member is attached to the first side wall portion.
The passenger conveyor according to claim 4, wherein a continuous notch is formed in the detector from the tip portion to the main body portion.
In a passenger conveyor provided with a deck portion that supports the balustrade portion and an inlet portion that is provided at an end portion of the deck portion in the longitudinal direction and in which a moving handrail of the balustrade portion enters and exits.
The inlet portion is
An inlet cover provided with an insertion recess for the moving handrail to enter and exit,
It has a safety mechanism arranged on the inlet cover and
The front portion of the inlet cover on the passenger entrance / exit side is inclined with respect to the moving direction of the moving handrail, and the insertion recess is provided.
The safety mechanism
A detector that surrounds a part of the circumference of the moving handrail, a part of which is inserted into the insertion recess, and the tip of the entrance / exit side is inclined with respect to the moving direction.
It has a detection switch that detects the displacement of the detector, and
A passenger conveyor in which the side wall portion of the insertion recess and a part of the protrusion inserted into the insertion recess in the detector are in contact with each other.
The passenger conveyor according to claim 1 or 8, wherein the front portion is inclined in a direction in which one end on the inside in the width direction orthogonal to the moving direction is inclined in a direction closer to the deck than the other end on the outside.