JPH11276787A - Washing and drying machine - Google Patents

Abstract

(57) [Summary] PROBLEM TO BE SOLVED: To carry out drying by bringing hot air for drying into contact with laundry stored in a washing and dewatering tub, and to particularly remove moisture evaporating from the laundry in the drying step. A washer / dryer that can be efficiently and reliably recovered with a simple structure without specially providing a flow path. SOLUTION: In the washing / drying machine provided with hot air supply means for supplying warm air into the washing and dewatering tub 6 during a drying step, and provided with dehumidifying means for condensing and recovering moisture evaporated from laundry, Is provided as a dehumidifying space with a clearance space 41 between the inner wall surface of the water tub 5 and the outer wall surface of the washing and dewatering tub 6, and a cooling water supply unit is provided above the dehumidifying space 41, and the cooling water is supplied to the water supply unit. A water supply port 48 for supplying water so as to hit the upper outer surface of the washing and dewatering tub 6 was formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washing and drying machine for drying a laundry by supplying warm air into a washing and dewatering tub in a drying step of a washing and drying operation, and recovering evaporated water as water. is there.

[0002]

2. Description of the Related Art A washing / drying machine that efficiently dries warm laundry to a laundry housed in a washing / dewatering tub and dries the water and collects evaporated water as water is disclosed in, for example, Japanese Patent Laid-Open No. 6-32789.
No. 6 discloses this. FIG.
FIG. 1 is a structural diagram of a washing / drying machine disclosed in Japanese Patent No. 27896;
In the figure, 1 is an outer box, 2 is a tob cover disposed on the upper part of the outer box 1 and provided with an opening 3 for taking in and out the laundry, and the opening 3 can be opened and closed by a lid 4.

[0005] Reference numeral 5 denotes a water tank for storing a washing liquid and a rinsing liquid in the outer case 1, which is swingably supported by the outer case 1 by a vibration isolator (not shown). 6 is rotatably disposed in the water tank 5,
A washing and dewatering tub having a plurality of dewatering holes 6a formed in a peripheral wall surface;
Is a rotary wing that is rotatably arranged on the bottom of the washing and dewatering tub 6,
Reference numeral 8 denotes a driving device which is provided on the outer bottom of the water tub 5 and provides a driving force for rotating the rotating blades 7 and the washing and dewatering tub 6, and a motor 9 for generating a driving force and a motor 9 for reducing the driving force. It is composed of a main shaft pulley 12 connected to the motor pulley 10 to be transmitted by a belt 11, a gear device 14, and a clutch device 13 for switching a driving force to the gear device 14.

A ring-shaped balancer 15 is attached to the periphery of the upper end of the washing and dewatering tub 6 and reduces the vibration of the washing and dewatering tub 6 in the dewatering step. A reference numeral 16 covers the upper part of the water tub 5 from above the balancer 15. , A ring-shaped tub cover for suppressing splashing of water due to the rotation of the washing and dewatering tub 6, 17 is provided on the top cover 2, and a hose connection port for supplying washing water and rinsing water into the tub 5, 18 is provided Aquarium 5
This is a drain valve provided on the drain pipe connected to the bottom of the.

A hot air generator 19 is provided in a space formed between the top cover 2 and the water tank cover 16 in the outer box 1 and comprises a blower 20 and a heater 21. Then, an air flow is generated, and this air flow is heated by the heater 21 and the hot air 22 is blown into the washing and dewatering tub 6. Reference numeral 23 denotes a flexible duct having one end connected to the water tank cover 16 and the other end connected to the hot air generator 19, and communicating between the hot air generator 19 and the water tank 5.

Reference numeral 24 denotes a hot air backflow blocking member having a triangular projection 25 formed at the center, and flexible thin plates 26 provided above and below the projection 25. It is configured so as to protrude so as to maintain a gap with the washing and dewatering tub 6, smoothly interlock the water passing through the space A between the washing and dewatering tub 6 and the water tub 5, and shut off the air flow.

Reference numeral 27 denotes an outlet 28 at one end and the valve plate 2 at the other end.
9 is an overflow pipe, 30 is a hot air generator 19
The dehumidifier communicates with the dehumidifier 30 in the valve plate 29.
And an outlet 28 of the overflow pipe 27 is connected to the drain valve 18 to make the drain valve 18 and the dehumidifier 30 communicate with each other.

Reference numeral 32 denotes an inner lid for closing the center opening of the ring-shaped water tank cover 16, reference numeral 7a denotes a rotary blade ventilation hole formed in the rotary blade 7, and reference numeral 33 denotes a ventilation hole formed in the inner bottom of the washing and dewatering tank 6. .

Next, the operation of the drying step set after each of the washing, rinsing and dehydrating steps will be described. Blower 2
When the heater 0 and the heater 21 operate, warm air is generated and blown out of the duct 23 into the washing and dewatering tub 6.
In this case, the warm air flows into the clearance space B between the lower surface of the water tub cover 16 and the upper end of the washing and dewatering tub 6, and is directly blown from the clearance space B into the washing and dewatering tub 6.

The warm air that has entered the washing and dewatering tub 6 comes into direct contact with the water-containing laundry on the rotating blades 7 in the washing and dewatering tub 6 after the dehydration step, and this is dried. Let it.

The warm air, which has been deprived of the moisture contained in the laundry and has increased in humidity, passes through a vent 33 formed in the bottom of the washing and dewatering tub 6 to allow the water to flow between the water tub 5 and the washing and dewatering tub 6. Although it flows into the clearance space A, since the upward flow is blocked by the hot air backflow blocking member 24, it flows as a downward airflow through the drain pipe to the drain valve 18, and from the outlet 28 the overflow pipe 27 and the exhaust duct 31. After that, it is guided to the dehumidifying device 30.

The warm air 22a having a high humidity is supplied to the dehumidifier 3
At 0, the air is cooled and condensed, and is again turned into warm air 22 from the warm air generator 19 and blown into the washing and dewatering tub 6. A drying step of drying the laundry by performing the above operation for a predetermined time is performed.

The hot air blown out from the duct 23 also flows into the space A between the water tub 5 and the washing and dewatering tub 6, but is prevented from flowing downward by the hot air backflow blocking member 24.
It is effectively supplied into the washing and dewatering tub 6.

[0014]

In the washing and drying machine as described above, the hot air backflow blocking member 24 is provided in the clearance A between the washing and spin-drying tub 6 and the water tub 5, so that the washing and drying can be performed in the drying step. The heat-exchanged air is prevented from flowing backward through the gap A between the washing and dewatering tub 6 and the water tub 5 to mix with the hot air newly supplied into the water tub 5, thereby preventing the heat exchange. The discharged air flows from the outlet 28 of the drain valve 18 through the overflow pipe 27 and the exhaust duct 31 to the dehumidifier 3
Although it is guided to zero and water is condensed and removed, there is a structural problem that the air flow path to the dehumidifying mechanism such as the overflow pipe 27 and the exhaust duct 31 has a complicated configuration.

Further, since the water tank 5 swings due to the unbalance of the clothes and the like, the duct 23 and the exhaust duct 31 communicating therewith are made of flexible members, but the wear and the swing of the material due to the swing are extremely large. In some cases, this cannot be absorbed, which may lead to detachment of the connection portion and destruction of components.

Further, since a complicated air path is routed, the pressure loss is increased, a large blower is required, and the cost is increased.

An object of the present invention is to eliminate the disadvantages of the prior art and to dry the laundry contained in the washing and spin-drying tub by contacting it with hot air for drying. In particular, a simple structure without any special dehumidification flow path is provided for the dehumidified water at a low cost that can be efficiently and reliably recovered, and cooling water used for dehumidification flows into the washing and dewatering tub. An object of the present invention is to provide a washing and drying machine which can surely prevent the washing and drying of the clothes in the washing and dewatering tub from getting wet with cooling water.

[0018]

According to the present invention, in order to achieve the above object, first, a washing and dewatering tub having an open upper surface is rotatably disposed in a water tub supported in an outer box. Rotating blades are provided at the bottom of the washing and dewatering tub, and hot air supply means for supplying hot air to the washing and dewatering tub during a drying step is provided, and dehumidifying means for condensing and recovering moisture evaporated from the laundry. In the washing and drying machine provided with, the dehumidifying means is provided with a gap space between the inner wall surface of the water tub and the outer wall surface of the washing and dewatering tub as a dehumidifying space, and a cooling water supply section is provided above the dehumidifying space, The water supply section is formed with a water supply port that supplies cooling water to the upper outer surface of the washing and dewatering tub, so a duct for dehumidification is separately provided by using the clearance space provided in the washing and drying machine. There is no need to provide specially, and the dehumidifying mechanism can be formed in a simple structure. .

Secondly, a balancer is provided at the upper part of the washing and dewatering tub, and cooling water is supplied so as to hit the outer surface of the balancer. This cooling water is scattered into the washing and dewatering tub. There is no inflow, and no cooling water is applied to the dried clothes in the washing and dewatering tub.

Thirdly, a water supply port is provided in a water receiving portion for receiving cooling water from an upper supply portion, and the water receiving portion is provided at a position farthest from the balancer so as to guide the cooling water to the outer surface of the balancer. Since the rib provided with the water opening protrudes from the periphery of the water supply port, the flow of the cooling water supplied to the water receiving portion is restricted by the rib, and only from the opening formed in the rib. It flows into the water inlet. Therefore, the flowing direction of the cooling water flowing downward from the water supply port is regulated in the direction of the balancer outer surface by the rib having the opening located farthest from the balancer.

Fourth, the water receiving portion is formed on an inclined surface which is inclined downward toward the side of the opening provided in the rib.
Since the cooling water supplied from the upper supply unit to the water receiving unit flows along the water receiving unit along the inclined surface in the direction of the opening, the cooling water surely flows out of the opening to the water supply port.

Fifth, a water guide plate projects downward from the water supply port at the position of the opening provided in the rib, and the lower portion of the guide plate is formed as a curved portion facing the outer surface of the balancer. ,
The cooling water flowing downward from the water supply port flows along the curve of the curved portion of the guide plate, and is reliably supplied to the outer surface of the balancer.

Sixth, since the guide plate is formed on a curved surface portion which is inclined downward at the tip of the curved portion, the cooling water flowing along the guide plate as described above is finally applied to the tip of the guide plate. By flowing along the small curved surface of the balancer, the flow-down direction is regulated so as to smoothly go to the outer surface of the balancer at the forefront of discharge.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an overall vertical sectional side view showing an embodiment of a washing / drying machine of the present invention, and the same components as those of the conventional example already described with reference to FIG. 4 are denoted by the same reference numerals.

The overall structure of the washing / drying machine of the present invention functioning as a washing machine is the same as the conventional one.
Reference numeral 2 denotes a top cover which is disposed above the outer box 1 and has an opening 3 for taking in and out the laundry, and the opening 3 can be opened and closed by a lid 4.

Reference numeral 5 denotes a water tank for storing a washing liquid and a rinsing liquid in the outer case 1, which is swingably supported by the outer case 1 by a vibration isolator (not shown). 6 is rotatably disposed in the water tank 5,
A washing and dewatering tub having a plurality of dewatering holes 6a formed in a peripheral wall surface;
Is a rotary wing that is rotatably arranged on the bottom of the washing and dewatering tub 6,
Reference numeral 8 denotes a driving device which is provided on the outer bottom of the water tub 5 and provides a driving force for rotating the rotor 7 and the washing and dewatering tub 6. The motor 9 generates the driving force, and the driving force is reduced and transmitted. A main shaft pulley 12 connected to a motor pulley 10 to be driven by a belt 11, a gear device 14, and a clutch device 13 for switching a driving force to the gear device 14.

Reference numeral 15 denotes a ring-shaped balancer attached to the periphery of the upper end of the washing and dewatering tub 6 for reducing vibration of the washing and dewatering tub 6 in the dehydrating step. , A ring-shaped water tank cover for suppressing splashing of water due to rotation of the washing and dewatering tank 6, a drain valve 18 provided at the bottom of the water tank 5 and connected to a drain hose 40, and 32 a water tank 5 in the drying step. The inner lid 39 is a baffle provided on the inner wall of the washing and dewatering tub 6 so as to be able to open and close for taking in and out the laundry.

Reference numeral 19 denotes a hot air generator provided in a space formed between the top cover 2 and the water tank cover 16, and a blower 20 and a heater 21 provided by a blower fan 20b driven by a motor 20a in a heater case 19a. Is arranged,
Blower duct 3 formed integrally with heater case 19a
The warm air exhaust port 35 formed at the lower end of 4 is opposed to the warm air intake port 36 formed in the inner lid 32 in a separated state.

An exhaust port 37 for warm air from the side of the water tub 5 is provided above the gap 41 between the washing and dewatering tub 6 and the water tub 5, and an inlet for warm air formed in the heater case 19a. An opening is provided below 38 so as to oppose it in a separated state.

In this case, the blower fan 20b is located above the intake port 38 in the heater case 19a, and the heater 21 is disposed downstream thereof.

A clearance space 41 between the washing and dewatering tub 6 and the water tub 5 is used as a dehumidifying space, and a dehumidifying mechanism 45 is provided here.
As an example, the dehumidifying mechanism 45 is provided with a supply section 46 having a water injection hole as a cooling water supply section in a stationary section such as the top cover 2 on the upper part of the outer box 1 as shown in FIG. At a position facing the upper surface of the balancer 15 disposed on the upper end edge of the washing and dewatering tub 6, the water receiving portion 47 for receiving the cooling water is separated from the supply portion 46 and the water tub cover 1 is provided.
6.

The water receiving section 47 has a flat bottom inclined section 47.
a, and a flat rectangular water supply port 48 was formed at the lowermost end thereof. In this case, the formation position of the water supply port 48 is located above the balancer 15 and outside the outer portion thereof as shown in FIGS.

On the periphery of the water supply port 48, a rib 49 is provided in a rectangular shape so as to be located on the upper surface of the water receiving portion 47.
An opening 50 for water passage was provided by cutting out one side of a square, which is the farthest part from the balancer 15 of FIG.

Further, a plate-like water guide plate 51 projects downward from the water supply port 48 at the position of the opening 50 provided in the rib 49, and a lower portion of the guide plate 51 is formed on the outer surface of the balancer 15. The leading end of the curved portion 51a is formed on a small curved surface portion 51b inclined further downward.

Next, the operation of the drying step set after each of the washing, rinsing and dehydrating steps is described. When the blower fan 20b and the heater 21 operate, the air in the heater case 19a is heated, and hot air is generated, and the warm air flows from the exhaust port 35 at the lower end of the blower duct 34 to the intake port on the water tank 5 side. The hot air is blown out toward the washing and dewatering tub 6.

In this case, since the intake port 36 is located immediately below the exhaust port 35, the hot air can be efficiently sent from the exhaust port 35 to the intake port 36, and leakage of the hot air can be prevented. Further, since the exhaust port 35 and the intake port 36 are separated from each other and are not in contact with each other, even if the water tank 5 shakes, the top cover, which is a stationary portion where the heater case 19a is disposed, does not affect the water tank 5.

The warm air blown into the washing and dewatering tub 6
After the spin-drying step is completed, the spin-drying tub 6 comes into direct contact with the water-containing laundry on the rotating blades 7 of the washing and spin-drying tub 6, and is dried.
The hot air, which has been deprived of moisture contained in the laundry and becomes humid, passes through a ventilation hole or a dewatering hole 6a formed at the bottom of the washing and dewatering tub 6 and a clearance space 41 between the water tub 5 and the washing and dewatering tub 6. Flow into

This gap space 41 is a dehumidifying space, and the hot air which has taken the moisture contained in the laundry and becomes humid is collected here. Next, an example of the method will be described. For example, tap water is injected into the cooling water supply unit 46, and the cooling water is supplied from the bottom water injection hole to the lower water receiving unit 47 as cooling water.

The cooling water supplied to the water receiving part 47 flows in the direction of the water supply port 48 along the inclined part 47a on the bottom surface.
At this time, since the rib 49 protrudes around the water supply port 48, the cooling water hitting the rib 49 flows along the periphery of the rib 49 and reaches the opening 50, from which the water supply port 48
Flows into.

The cooling water flowing into the water supply port 48 flows along the slope of the curved portion 51a of the guide plate 51 projecting downward, and flows into the clearance space 41 along the curve of the small curved surface portion 51b at the tip. I do. At this time, since the guide plate 51 is located farthest from the outer surface of the balancer 15 and is located toward the balancer 15 in the clearance space 41 above it, the cooling water flowing down from the tip of the guide plate 51 is Discharge toward the outer surface of the balancer 15, and the balancer 1
5 outer surface.

Therefore, the cooling water comes into contact with the hot air containing moisture in the gap space 41 to directly cool the hot air,
Alternatively, the side wall of the washing and dewatering tub 6 around the gap space 41 and the side wall of the water tub 5 are cooled with cooling water, so that the hot air is cooled, and the moisture contained in the hot air is condensed and collected. .

As described above, the cooling water falling into the gap 41 hits the outer surface of the balancer 15 of the washing and dewatering tub 6 at a position diagonally below the water supply port 48.
The cooling water can be blown in the direction of the interstitial space 41 which is a dehumidifying space using the rotation of the washing and dewatering tub 6.

Moreover, the position where the cooling water is dropped is the balancer 1
Since the water supply port 48 is formed so as to be on the outer surface of the washing and dewatering tub 6, the cooling water dropped here does not flow into the washing and dewatering tub 6. Can be prevented.

In the above embodiment, the cooling water is supplied so as to impinge on the outer surface of the balancer 15 as a preferred example. However, the present invention is not limited to this. In the case where the dewatering hole 6a is not provided, it is needless to say that the same effect can be obtained even if the water is supplied so as to hit the upper outer surface of the washing and dewatering tub 6.

[0045]

As described above, the washing and drying machine of the present invention firstly comprises a washing and spin-drying tub having an open upper surface in a water tub supported in an outer box. Rotor blades are provided at the bottom of the washing and dewatering tub, hot air supply means for supplying hot air to the washing and dewatering tub during the drying step is provided, and dehumidifying means for condensing and recovering moisture evaporated from the laundry is provided. In the provided washer / dryer, the dehumidifying means includes a clearance space between an inner wall surface of the water tub and an outer wall surface of the washing and dewatering tub as a dehumidifying space, and a cooling water supply unit provided above the dehumidifying space. In the part, a water supply port that supplies cooling water so as to hit the outer surface of the balancer of the washing and dewatering tub is formed, and a duct for dehumidification is separately provided by using the clearance space provided in the washing and drying machine. Dehumidifying mechanism is formed in a simple structure without special installation Kill.

Secondly, a balancer is provided at the upper part of the washing and dewatering tub, and cooling water is supplied so as to hit the outer surface of the balancer. This cooling water scatters into the washing and dewatering tub. There is no inflow, and no cooling water is applied to the dried clothes in the washing and dewatering tub.

Thirdly, a water supply port is provided in a water receiving portion that receives cooling water from an upper supply portion, and the water receiving portion is provided at a position farthest from the balancer so as to guide the cooling water to the outer surface of the balancer. Since the rib provided with the water opening protrudes from the periphery of the water supply port, the flow of the cooling water supplied to the water receiving portion is restricted by the rib, and only from the opening formed in the rib. It flows into the water inlet. Therefore, the flowing direction of the cooling water flowing downward from the water supply port is regulated in the direction of the balancer outer surface by the rib having the opening located farthest from the balancer.

Fourthly, the water receiving portion is formed on an inclined surface which is inclined downward toward the side of the opening provided in the rib.
Since the cooling water supplied from the upper supply unit to the water receiving unit flows along the water receiving unit along the inclined surface in the direction of the opening, the cooling water surely flows out of the opening to the water supply port.

Fifthly, a water guide plate projects downward from the water supply port at the position of the opening provided in the rib, and the lower portion of the guide plate is formed as a curved portion facing the outer surface of the balancer. ,
The cooling water flowing downward from the teapot position flows along the curve of the curved portion of the guide plate, and is reliably supplied to the outer surface of the balancer.

Sixth, since the guide plate is formed on a curved surface portion which is inclined downward at the tip of the curved portion, the cooling water flowing along the guide plate as described above finally returns to the tip of the guide plate. By flowing along the small curved surface of the, the downward flow direction is regulated so as to smoothly go to the outer surface of the balancer at the forefront of discharge.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of a washing and drying machine of the present invention.

FIG. 2 is a vertical sectional side view of a main part of the washing and drying machine of the present invention.

FIG. 3 is a plan view of a main part of the washing and drying machine of the present invention.

FIG. 4 is a vertical sectional side view of a conventional washer / dryer.

[Explanation of symbols]

1 ... Outer box, 2 ... Top cover, 3 ...
Opening, 4 ... lid, 5 ... water tank,
6 ... washing and dewatering tub, 6a ... dewatering hole, 7 ...
Rotor blade, 7a Rotor blade vent, 8 Drive unit, 9 Motor, 10 Motor pulley, 11 Belt, 12 Spindle pulley
13: clutch device, 14: gear device, 15
... Balancer, 16 ... Water tank cover, 17 ... Hose connection port, 18 ... Drain valve, 19 ... Hot air generator, 19a ... Heater case, 20 ... Blower,
20a: motor, 20b: blower fan, 21: heater, 22: hot air, 22a: hot air with high humidity, 2
3 ... duct, 24 ... warm air backflow blocking member, 25 ...
Projection, 26: thin plate, 27: overflow pipe, 28: outlet, 29: valve plate, 30: dehumidifier, 31: exhaust duct,
32: inner lid, 33: vent, 34: air duct, 35: exhaust port, 36: intake port, 37
... exhaust port, 38 ... intake port, 39 ... baffle, 40 ... drain hose, 41 ... gap space,
45 ... dehumidifying mechanism, 46 ... supply unit, 47 ...
Water receiving part, 47a ... inclined part, 48 ... water supply port,
49: rib, 50: opening, 51: guide plate, 51a: curved portion, 51b: curved surface portion

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Katsunori Ishii 1-1-1 Yamate, Funabashi-shi, Chiba Prefecture Inside Nippon Steel Corporation (72) Inventor Kunio Inose 1-1-1 Yamate, Funabashi-shi, Chiba Japan (72) Inventor Mamoru Katano 1-1-1 Yamate, Funabashi-shi, Chiba Japan Incorporated Steel Corporation (72) Inventor Yoshio Yoshida 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Inside (72) Inventor Shinichi Nakamura 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Masaji Kukino 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric (72) Inventor Shinsuke Ise 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Kazuhiko Manya Marunouchi, Chiyoda-ku, Tokyo Eye No. 2 No. 3 Mitsubishi Electric Co., Ltd. in

Claims (6)

[Claims] 1. A washing and dewatering tub having an open upper surface is rotatably disposed in a water tub supported in an outer case, and a rotating blade is disposed at a bottom portion of the washing and dehydration tub. A washing / drying machine provided with hot air supply means for supplying warm air to the washing and dewatering tub, and provided with dehumidifying means for condensing and recovering moisture evaporated from the laundry. The space between the outer wall of the tank and the dewatering tub is used as a dehumidifying space, and a cooling water supply unit is provided above the dehumidifying space, so that the cooling water is applied to the upper outer surface of the washing and dewatering tub. A washing / drying machine having a water supply port for supplying water. 2. The washing and drying machine according to claim 1, wherein a balancer is provided at an upper portion of the washing and dewatering tub, and cooling water is supplied so as to hit an outer surface of the balancer. 3. A water supply port is provided in a water receiving section for receiving cooling water from an upper supply section, and the water receiving port is provided at a position farthest from the balancer so as to guide the cooling water to an outer surface of the balancer. 3. The washing / drying machine according to claim 2, wherein the rib provided with the opening protrudes from the periphery of the water supply port. 4. The washing and drying machine according to claim 3, wherein the water receiving portion is formed on an inclined surface which is inclined downward toward an opening provided in the rib. 5. The water supply port is provided with a water guide plate projecting downward at the position of the opening provided in the rib, and a lower portion of the guide plate is formed as a curved portion facing the outer surface of the balancer. The washing / drying machine according to any one of claims 2 to 4, wherein 6. The washing and drying machine according to claim 5, wherein the guide plate is formed as a small curved surface portion which is inclined downward at the tip of the curved portion.