CN110872777A

CN110872777A - Frame for clothes dryer

Info

Publication number: CN110872777A
Application number: CN201910705541.7A
Authority: CN
Inventors: 川村祥彰; 本田民树
Original assignee: Rinnai Corp
Current assignee: Rinnai Corp
Priority date: 2018-08-29
Filing date: 2019-08-01
Publication date: 2020-03-10
Also published as: KR20200026077A; JP7277091B2; JP2020031843A

Abstract

The invention provides a frame for a clothes dryer, which can prevent the reduction of the workability during the assembly. A frame (2) of a clothes dryer (D) is composed of a top plate (20), a bottom plate (21), a front plate (22), a rear cover (23) and opposite left and right side plates (24). The front plate (22) is provided with a clothes inlet (2b) for inputting clothes into a drum arranged in the frame body (2). The frame (2) constitutes a frame unit (25) composed of a bottom plate (21), a front plate (22), and left and right side plates (24), and the top plate (20) and the rear cover (23) are detachable from the frame unit (25).

Description

Frame for clothes dryer

Technical Field

The present invention relates to a frame for a clothes dryer used in a clothes dryer for drying washed clothes, towels, sheets, and the like.

Background

A laundry dryer in which a rotary drum is disposed inside a casing for the laundry dryer (hereinafter also simply referred to as "casing") has been known (see, for example, patent document 1).

In such a clothes dryer, laundry (including clothes such as towels and sheets of the laundry) is stored in a rotary drum, and then the rotary drum is rotated while supplying warm air into the rotary drum, thereby drying the laundry therein. In this way, by rotating the rotary drum during drying, the laundry inside is not stopped at a fixed position but is always in a moving state. As a result, the warm air is uniformly blown to the clothes, and the clothes can be efficiently dried.

Such laundry dryers are generally equipped in the following manner: after the internal devices are carried into a housing unit (i.e., a member including a top plate, a bottom plate, a front plate, and opposing left and right side plates) having an open rear surface side (rear side) from behind, a rear cover is fixed to the rear surface side of the housing unit.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-102800

Disclosure of Invention

Problems to be solved by the invention

However, in the clothes dryer described in patent document 1, when the internal device is assembled inside the housing, the assembly work must be performed in the internal space other than the back side surrounded by a metal plate member or the like, which causes a problem of reduced workability. For example, since the movement of the head of the operator is hindered by the top plate, the operator needs to perform the assembly work of the internal device while keeping the posture thereof fixed to some extent.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a clothes dryer capable of preventing a reduction in workability at the time of assembly.

Means for solving the problems

The frame for the clothes dryer of the invention is composed of a top plate, a bottom plate, a front plate, a rear cover and a left side plate and a right side plate which are opposite, a drum for accommodating clothes and drying the clothes is arranged in the frame for the clothes dryer, a clothes input opening for inputting the clothes into the drum is arranged on the front plate,

the bottom plate, the front plate and the left and right side plates constitute a frame unit,

the top plate and the rear cover are detachable from the housing unit.

In this way, the frame for a clothes dryer of the present invention is configured such that the top plate and the rear cover are detachable from the frame unit constituted by the bottom plate, the front plate, and the left and right side plates.

Thus, the frame for the clothes dryer can be assembled according to the order of fixing the top plate and the rear cover after the internal equipment is assembled in the frame unit. That is, the internal device can be assembled with not only the rear cover but also the top plate removed. As a result, the assembly work can be performed by inserting the housing into the internal space of the housing not only from the rear but also from above.

Therefore, according to the casing for the clothes dryer, unlike the conventional casing, the casing can be inserted into the internal space of the casing from above, and thus, it is possible to prevent a reduction in workability due to the members themselves constituting the casing.

In the laundry dryer casing according to the present invention, it is preferable that the casing unit includes a casing member and the front panel detachably attached to the casing member, the casing member includes the bottom panel, the left and right side panels, and a reinforcing member extending between the left and right side panels, and left and right end portions of the reinforcing member are fixed to the left and right side panels, respectively.

With this configuration, the bottom plate and the reinforcing member maintain the space between the left and right side plates, and therefore, even if the front plate is removed and only the frame member is left, the left and right side plates can be maintained in the state of being erected with respect to the bottom plate. That is, when the internal device is assembled, not only the top plate and the rear cover but also the front plate can be detached. This allows the housing to be inserted into the internal space of the housing from the front, and the assembly operation can be performed, thereby further preventing the workability from being lowered during assembly.

In the case where the frame for a clothes dryer according to the present invention is configured to include the reinforcing member, it is preferable that left and right ends of the reinforcing member are fixed to front edges of the left and right side plates, respectively, the reinforcing member has a 1 st locking portion, and the front plate has a 1 st locked portion locked to the 1 st locking portion on a rear side.

With this configuration, the front plate can be fixed to the frame member via the reinforcing member. Thus, the front plate and the frame member can be fixed without screwing the front plate from the front surface side (front side). As a result, not only can the workability during assembly be prevented from being lowered, but also the front side appearance can be improved.

In the case where the frame for a clothes dryer according to the present invention is configured to include the reinforcing member, it is preferable that left and right ends of the reinforcing member are fixed to upper ends of front side edges of the left and right side plates, respectively, the reinforcing member has a 2 nd locking portion, and the top plate has a 2 nd locked portion locked to the 2 nd locking portion at a front end thereof.

With this configuration, the front end edge of the top plate is reinforced by the reinforcing member. This can suppress the deflection of the top plate and suppress the occurrence of a gap. As a result, the front surface and the upper surface can be more aesthetically improved. Further, dust and the like can be prevented from entering the gap.

Drawings

Fig. 1 is a longitudinal sectional view schematically showing a structure of a laundry dryer according to an embodiment of the present invention.

Fig. 2 is a perspective view showing a shape of a housing of the laundry dryer of fig. 1 as viewed from the front.

Fig. 3 is a perspective view showing a housing unit and a top plate constituting the housing of fig. 2, as viewed from the front.

Fig. 4 is a perspective view showing a housing unit and a top plate constituting the housing of fig. 2, as viewed from the rear.

Fig. 5 is a perspective view showing a frame member, a front plate, and a top plate constituting the frame unit of fig. 3 and 4, as viewed from the front.

Fig. 6 is an enlarged view of the upper end front plate side of the frame member of fig. 5.

Description of the symbols

1 rotary drum, 1a rotary shaft of the drum, 1b front open part, 1c back wall, 1d reinforcing plate, 2 frame (frame for clothes dryer), 2a back wall, 2b clothes inlet, 2c air inlet, 3 supporting shaft, 4 door, 5 ring plate, 5a warm air outlet, 6 filter unit, 7 exhaust passage, 7a exhaust port, 8a dehumidifying fan, 8b fan box, 8c rotary shaft of the fan, 9 motor, 9a 1 st driving shaft, 9b 2 nd driving shaft, 9c 1 st driving belt, 9d 2 nd driving belt, 10 combustion unit, 10a gas burner, 10b gas jet nozzle, 10c gas supply valve device, 10d gas inlet, 11 warm air duct, 12 controller, 12a operation panel, 20 top plate, 20a ceiling part, 20b … front end, 20c … side, 20D … the 1 st stop protrusion (the 2 nd part to be locked), 20e … the 2 nd stop protrusion (the 3 rd part to be locked, the 4 th part to be locked), 21 … bottom plate, 22 … front plate, 22a … extension setting, 22b … the 1 st part to be locked, 23 … back cover, 24 … side plate, 24a … the 1 st edge, 24b … the 2 nd edge, 24c … the 3 rd edge, 24D … the 3 rd locking part, 24e … the 4 th edge, 24f … the 4 th locking part, 25 … frame unit, 26 … reinforcement, 26a … the 1 st end, 26b … the 2 nd end, 26c … main body (the 1 st locking part), 26D … the 2 nd part to be … carry part, 27 … frame member, D … clothes dryer, W … clothes.

Detailed Description

Hereinafter, a clothes dryer D including a housing 2 as a housing for a clothes dryer according to an embodiment will be described with reference to the drawings.

First, a schematic configuration of the laundry dryer D will be described with reference to fig. 1.

As shown in fig. 1, the laundry dryer D includes a rotary drum 1, and the rotary drum 1 stores laundry W (fabric articles including towels, bed sheets, and the like of so-called laundry) and dries the laundry W while rotating. The rotary drum 1 is rotatably provided inside a housing 2 (a housing for a laundry dryer).

A support shaft 3 extending toward the front is provided on the rear wall 2a of the housing 2. A drum rotating shaft 1a provided in the rotary drum 1 is rotatably attached to the support shaft 3. Thereby, the rotary drum 1 is set in a horizontal posture (posture with the axis in the horizontal direction).

A front opening 1b is formed at the front end of the rotary drum 1. A laundry inlet 2b covered with a single-opening door 4 is provided on the front side of the frame 2 corresponding to the front opening 1b of the rotary drum 1. An annular plate 5 is attached to the outer periphery of the laundry inlet 2b of the housing 2. The rotary drum 1 is rotatably supported by the annular plate 5 via the front opening 1 b.

The drum shaft 1a is provided on the inner wall 1c of the rotary drum 1. A filter unit 6 is attached to an end portion of the drum shaft 1a on the inner side of the rotary drum 1. A reinforcing plate 1d is attached to an outer end of the rotary drum 1 of the drum shaft 1a, and the reinforcing plate 1d reinforces the back wall 1c of the rotary drum 1 supported by the shaft.

An exhaust duct 7 for guiding air in the rotary drum 1 to the outside of the housing 2 is provided outside the back wall 1c of the rotary drum 1. The exhaust duct 7 is located between the back wall 1c of the rotary drum 1 and the back wall 2a of the housing 2. An exhaust port 7a that opens at the upper portion of the housing 2 is provided at the downstream end of the exhaust passage 7. A fan case 8b containing a dehumidifying fan 8a therein is provided on the upstream side of the exhaust duct 7. The dehumidifying fan 8a includes a fan shaft 8c rotatably supported by the support shaft 3.

The dehumidifying fan 8a generates an air flow for introducing warm air into the rotary drum 1 while discharging air in the rotary drum 1 having high humidity due to drying of the laundry W. That is, when the dehumidifying fan 8a rotates, the outside air is taken into the inside of the housing 2 from the air inlet port 2c formed in the bottom of the housing 2. The outside air taken into the inside of the housing 2 is heated by flame of a gas burner 10a described later to form warm air, and is sent to the inside of the rotary drum 1 through a warm air duct 11 described later. The warm air having absorbed moisture of laundry W in rotary drum 1 flows through filter unit 6 to exhaust duct 7, and is discharged from exhaust port 7a to the outside of casing 2.

Inside the casing 2, a motor 9 for rotating the rotary drum 1 and the dehumidifying fan 8a, a combustion unit 10 for heating outside air to generate warm air, and a warm air duct 11 for guiding warm air into the rotary drum 1 are provided. Further, a controller 12 is provided for controlling the driving of the motor 9, the ignition and extinguishing operations of the combustion unit 10, and the like during the drying operation.

The motor 9 includes two drive shafts (a 1 st drive shaft 9a and a 2 nd drive shaft 9 b). The rotational force of the 1 st drive shaft 9a is transmitted to the rotary drum 1 via the 1 st belt 9c, and the rotary drum 1 is rotated. The rotation of the rotary drum 1 is to keep the laundry W accommodated inside moving without stopping at a fixed position. The rotational force of the 2 nd driving shaft 9b is transmitted to the fan rotating shaft 8c of the dehumidifying fan 8a via the 2 nd belt 9d, and the dehumidifying fan 8a is rotated. By the rotation of the dehumidifying fan 8a, an air flow is formed inside the rotary drum 1.

The combustion unit 10 is configured to include a gas burner 10a, an air injection nozzle 10b, and a gas supply valve device 10 c. The fuel gas supplied from the gas supply valve device 10c is injected from the gas injection nozzle 10b toward the gas inlet 10d of the gas burner 10 a. Thereby, the fuel gas is also guided to and burned by the gas burner 10a together with the air around the gas inlet 10d, and the outside air is heated. The combustion air supplied to the gas burner 10a is also taken in from the air supply port 2c in the bottom of the casing 2, similarly to the air for heating.

The warm air duct 11 extends from above the gas burner 10a to a warm air outlet 5a formed in the annular plate 5. The warm air heated by the gas burner 10a is guided to the warm air outlet 5a through the warm air duct 11, and is sent into the rotary drum 1.

The warm air sent into the rotary drum 1 dries the laundry W stored in the rotary drum 1, and then flows to the dehumidifying fan 8a through the filter unit 6. At this time, the looped yarns generated from the laundry W are captured by the filter unit 6.

The warm air with high humidity flowing to the dehumidifying fan 8a via the filter unit 6 enters from the front side of the dehumidifying fan 8a, flows to the outer periphery of the dehumidifying fan 8a, collects in the exhaust passage 7, and is discharged from the exhaust port 7 a.

An operation panel 12a is provided on a lower portion of the front surface side of the controller 12. The operation panel 12a is used to select control related to driving of the motor 9, ignition and extinguishing operations of the combustion unit 10, and the like during the drying operation.

Next, the structure of the casing 2 (casing for a clothes dryer) of the clothes dryer D and the method of assembling the same will be described in detail with reference to fig. 2 to 5.

As shown in fig. 2, the housing 2 is substantially cubic and includes a top plate 20, a bottom plate 21 (not shown in fig. 2, see fig. 4 and 5), a front plate 22, a rear cover 23, and a pair of left and right side plates 24 facing each other. The left and right side plates 24 may be provided to face each other. For example, the shape may be symmetrical or the same, or may be different from the left and right.

As described above, the operation panel 12a is provided at the lower portion of the front plate 22. Further, a laundry inlet 2b for introducing laundry into the rotary drum 1 located inside the housing 2 after assembly is provided at the center of the front plate 22. The laundry inlet port 2b is covered by a single-opening door 4. The rear cover 23 constitutes the aforementioned back wall 2 a.

As shown in fig. 3 and 4, the bottom plate 21, the front plate 22, and the pair of side plates 24 constitute a housing unit 25 as a unit. The top plate 20 and the rear cover 23 (see fig. 2) are detachable from the housing unit 25.

Thus, the housing 2 can be assembled in the order of fixing the top plate 20 and the rear cover 23 after the internal devices are assembled in the housing unit 25. That is, the housing 2 can be assembled with the internal devices removed from the top plate 20 as well as the rear cover 23. As a result, the worker can insert the inner space of the housing 2 not only from the rear but also from above, and perform the assembling operation.

As shown in fig. 5, a reinforcing member 26, which is an elongated substantially plate-shaped member, is bridged between the pair of side plates 24.

Specifically, the plate-like 1 st edge portion 24a extends inward from one of the pair of side plates 24 on the front plate 22 side along the end edge thereof. A 1 st end portion 26a, which is one end portion of the reinforcing member 26, is fixed to an upper end of the 1 st edge portion 24 a.

The plate-like 2 nd edge portion 24b extends inward from the other front plate 22 side end edge of the pair of side plates 24 along the end edge. A 2 nd end portion 26b as the other end portion of the reinforcing member 26 is fixed to the upper end of the 2 nd edge portion 24 b.

The bottom plate 21, the pair of side plates 24, and the reinforcing member 26 constitute a frame member 27 as one member. The front plate 22 is configured to be detachable from the frame member 27 via a reinforcing member 26 as described below.

Thus, when the internal device is assembled, the housing 2 can be set in a state in which not only the top plate 20 and the rear cover 23 but also the front plate 22 is removed. This allows the operator to insert the housing 2 into the internal space from the front and perform the assembling operation.

Therefore, according to the housing 2, unlike the conventional housing, the worker can insert the internal space of the housing from above and from the front and perform the assembling operation. This can prevent the reduction in workability of the members themselves (e.g., the top plate 20) constituting the housing 2.

In the housing 2, the housing unit 25 is composed of a housing member 27 and a front plate 22 that is detachable from the housing member 27. However, the housing for a clothes dryer according to the present invention is not limited to such a configuration, and the housing unit may be configured as a single member. That is, the frame unit may be configured such that the front plate is not detachable from the frame member.

As shown in fig. 6, the reinforcing member 26 is formed as an elongated substantially plate-shaped member. Specifically, in the reinforcing member 26, a main body portion 26c (1 st locking portion) which is a plate-like member is provided between the 1 st end 26a and the 2 nd end 26b which are both ends.

When the 1 st end portion 26a and the 2 nd end portion 26b provided at both end portions of the reinforcing member 26 are fixed to the pair of side plates 24, the body portion 26c stands upright so as to protrude upward from the upper edges of the pair of side plates 24.

On the other hand, as shown in fig. 4 and 6, the front plate 22 is provided with an extension portion 22a extending rearward (toward the rear cover 23) from the upper edge portion thereof. The height of the upper surface of the extension portion 22a corresponds to the height of the upper surface of the top plate 20 when the top plate 20 is attached to the frame member 27. Therefore, the upper surface of the extension portion 22a forms the upper surface of the housing 2 together with the upper surface of the top plate 20 (see fig. 2). Further, a plate-shaped 1 st engaged portion 22b is provided extending downward on the lower surface side of the extending portion 22 a.

In the frame member 27, the first engaged portion 22b is engaged with the body portion 26c of the reinforcing member 26 from above, whereby the front plate 22 is engaged with and attached to the frame member 27. That is, the front plate 22 is fixed to the frame member 27 via the reinforcing member 26.

Thus, in the frame member 27 (and further in the frame 2), the front plate 22 and the frame member 27 can be fixed without screwing the front plate 22 from the front surface side. As a result, the casing 2 can prevent a reduction in workability at the time of assembly and can improve the front side appearance.

In the housing 2, after the front plate 22 is attached to the housing member 27 in the above-described manner, the front plate 22 is fixed to the housing member 27 by screwing from behind the main body portion 26c of the reinforcing member 26 and the 1 st and 2

nd edge portions

24a, 24b of the side plate 24. The purpose is to firmly fix the front plate 22 to the frame member 27.

Therefore, when the fixing by the locking is sufficient, such screw fixing may be omitted. Conversely, the fixation by the locking may be omitted, and the front plate 22 may be fixed to the reinforcing member 26 only by screw fixation.

As shown in fig. 6, the reinforcing member 26 has elongated holes extending in the left-right direction, i.e., the 2 nd locking portions 26d, at both ends of the main body portion 26 c. Further, a plate-shaped placing portion 26e extends rearward from the lower end of the main body portion 26 c.

As shown in fig. 3 and 4, the plate-like 3 rd edge portion 24c extends inward from the end edge of one of the pair of side plates 24 on the top plate 20 side along the end edge. A 3 rd locking portion 24d, which is an elongated hole extending in the front-rear direction, is provided at the center of the 3 rd edge portion 24 c.

The plate-like 4 th edge portion 24e extends inward from the other end edge of the pair of side plates 24 on the top plate 20 side along the end edge. A 4 th locking portion 24f, which is an elongated hole extending in the front-rear direction, is provided at the center of the 4 th edge portion 24 e.

On the other hand, as shown in fig. 3, 5, and 6, the top plate 20 includes a top portion 20a having a substantially flat plate shape, a distal end portion 20b extending downward from an end edge in front of the top portion 20a (on the front plate 22 side), and a pair of side surface portions 20c extending downward from both sides of the top portion 20 a.

A plate-shaped 1 st locking protrusion 20d (2 nd locked portion) extending forward is provided at a position corresponding to the 2 nd locking portion 26d of the reinforcing member 26 at the lower edge portion of the end surface of the distal end portion 20 b.

At the lower ends of the pair of side surface portions 20c, plate-shaped 2 nd locking projections 20e (the 3 rd locked portion and the 4 th locked portion) extending downward are provided at positions corresponding to the 3 rd locking portion 24d and the 4 th locking portion 24f of the pair of side plates 24 when the top plate 20 is attached to the frame member 27.

In the housing 2, when the top plate 20 is attached to the housing unit 25, first, the 2 nd locking projection 20e is inserted into the 3 rd locking portion 24d and the 4 th locking portion 24 f. Then, by sliding the entire top plate 20 forward, the 1 st locking projection 20d is inserted into the 2 nd locking portion 26d, and the distal end portion 20b is brought into contact with the main body portion 26c of the reinforcing member 26. At this time, the distal end portion 20b is placed on the placement portion 26e of the reinforcing member 26.

This reinforces the edge on the front side of the top plate 20 by the reinforcing member 26. As a result, the top plate 20 can be prevented from being bent, and the occurrence of a gap can be prevented, so that the front surface and the upper surface of the housing 2 can be improved in appearance. Further, dust and the like can be prevented from entering the gap.

In the housing 2, as described above, after the top plate 20 is attached to the housing unit 25, the top plate 20 is fixed to the housing unit 25 by screwing from the rear of the front end portion 20b of the top plate 20. The purpose is to firmly fix the top plate 20 to the frame unit 25.

Therefore, when the fixation by the locking is sufficient, such screw fixation may be omitted. Conversely, the fastening by the locking may be omitted, and the top plate 20 may be fixed to the reinforcing member 26 only by screw fastening.

Further, the housing 2 is configured to: by inserting the 2 nd locking projection 20e into the 3 rd locking portion 24d and the 4 th locking portion 24f, the top plate 20 can be easily positioned with respect to the housing unit 25. However, when a separate positioning mechanism is provided, the 2 nd locking projection 20e, the 3 rd locking portion 24d, and the 4 th locking portion 24f may be omitted.

The embodiments shown in the drawings have been described above, but the present invention is not limited to such embodiments.

For example, in the above embodiment, the housing 2 of the present embodiment is configured such that: the front plate 22 is attached by being locked to the frame member 27 via the reinforcing member 26. The purpose is to make it possible to easily attach and detach the front plate 22 to and from the frame member 27, and to make the screw fastening invisible from the front side, thereby improving the appearance.

However, the frame for a clothes dryer according to the present invention is not limited to such a configuration, and the front plate may be detachably attached to the frame member without using a reinforcing member. For example, when a hole for screw fixation and a member for closing the hole are used, the reinforcing member may be omitted and the front plate may be attached to the frame member by only screw fixation.

In the housing 2, the reinforcing member 26 holds the gap between the pair of left and right side plates 24 together with the bottom plate 21. Therefore, in the housing 2, even if the front plate 22 is removed and only the housing member 27 is left, the pair of side plates 24 can be maintained in the state of being erected with respect to the bottom plate 21.

Therefore, when the reinforcing member is omitted, it is preferable to provide a mechanism that can maintain the interval between the left and right side plates and maintain the left and right side plates in the upright state with respect to the bottom plate. For example, the left and right side plates and the front plate may be integrally formed as a single member, and the bottom plate may be detachably attached to the member.

In the housing 2 of the present embodiment, the reinforcing member 26 is provided to facilitate attachment and detachment of the front plate 22 and the top plate 20. Therefore, the 1 st end 26a, which is one end of the reinforcing member 26, is fixed to the upper end of the 1 st edge 24a on the front plate 22 side of one of the pair of left and right side plates 24, and the 2 nd end 26b, which is the other end of the reinforcing member 26, is fixed to the upper end of the 2 nd edge 24b on the front plate 22 side of the other of the pair of side plates 24.

However, the frame for a clothes dryer according to the present invention is not limited to such a configuration, and the reinforcing member may be bridged between the left and right side plates. Specifically, the left and right end portions of the reinforcing member may be fixed to the left and right side plates, respectively. For example, in the case of a structure in which the front plate and the top plate are not locked to the reinforcing member, the front plate may be positioned at the center portion in the front-rear direction below the upper edges of the left and right side plates.

Claims

1. A frame for a clothes dryer, which is composed of a top plate, a bottom plate, a front plate, a rear cover, and left and right side plates facing each other, wherein a drum for storing clothes and drying the clothes is disposed inside the frame for the clothes dryer, and a clothes inlet for introducing the clothes into the drum is provided in the front plate,

the bottom plate, the front plate, and the left and right side plates constitute a frame unit, and the top plate and the rear cover are detachable from the frame unit.

2. Frame for a laundry dryer according to claim 1,

the frame unit is composed of a frame member and the front plate which is detachable with respect to the frame member, wherein the frame member is composed of the bottom plate, the left and right side plates and a reinforcing member which is spanned between the left and right side plates,

the left and right ends of the reinforcing member are fixed to the left and right side plates, respectively.

3. Frame for a laundry dryer according to claim 2,

the left and right end parts of the reinforcing member are respectively fixed to the front edge parts of the left and right side plates,

the reinforcing member has a 1 st locking portion,

the front plate has a 1 st locked part locked with the 1 st locking part at the rear side.

4. Frame for a laundry dryer according to claim 2 or 3,

the left and right end parts of the reinforcing member are respectively fixed to the upper ends of the front side edge parts of the left and right side plates,

the reinforcing member has a 2 nd locking portion,

the top plate has a 2 nd engaged portion engaged with the 2 nd engaging portion at a front end portion.