JP2510949B2 - Power open / close type snow throw hatch - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power opening / closing type snow throw hatch, and particularly to a snow throw installed in a snow throw area such as a snow drift groove or a snow melting tank, which is mainly constructed as a snow countermeasure facility in a snowy city. It relates to a mouth opening / closing snow throwing hatch.

[0002]

2. Description of the Related Art As a conventional open / close lid structure for a snow throwing port installed in a snow throwing area such as a snow drift groove or a snow melting tank, for example, Japanese Utility Model Publication No. 4-39,332 (Registered No. 1,969, No. 302 utility model) and Japanese Patent Laid-Open No. 4-202926.

In a cover for a snow drift groove described in Japanese Utility Model Publication No. 4-39,332, a receiving frame portion of a cover plate of a snow throwing port installed in the snow drift groove is formed in a taper shape, and the receiving frame is provided. It is possible to prevent water and ice from adhering to the receiving frame part by provision of an icing / separating material on the contact surface between the receiving frame part and the cover plate. Even if the ice is landed on the surface of the groove, it becomes thin ice that can be easily peeled off, so that the groove lid can be easily attached and detached.

The freezing releasing means for the opening / closing lid of the snow melting facility described in Japanese Patent Laid-Open No. 4-202,926 is a sheet heating element having a self-temperature control function in a frame surrounding the opening / closing lid provided in the snow throwing port. By applying a predetermined voltage and heating the periphery of the lid at a constant temperature, the opening and closing lid is prevented from freezing and the opening and closing lid is easily attached and detached.

As a conventional example of the snow throwing mouth 6 provided in the snow throwing area 3 such as a snow drift groove 3 or a snow melting tank as a snow countermeasure facility in a snowy city, for example, the conventional example of FIG. There is a schematic diagram of the main part.

This is provided with a snow throwing opening 6 at a proper position on the snow throwing area 2 of the first traveling zone 5A shown in FIG. 8, and an iron lid 7 of the snow throwing opening 6 is required by a crane vehicle or the like not shown. While removing the dump truck 8 around the open snow throw opening 6
Are brought close to each other, the loading platform 8A is erected, and snow is thrown to the snow throwing port 6.

From the viewpoint of improving the efficiency of snow throwing, the snow throwing port 6 is usually provided at an appropriate place above the snow throwing region 2 where a vehicle such as a dump truck 8 can pass, and therefore the top opening thereof is closed. Various vehicles such as the dump truck 8 travel on the iron lid 7.

This snow throwing port 6 is, for example, 3 m long by 3 m long.
If the distance is set to about 2 m, smooth snow throwing can be performed on the snow throwing hole 6, but the structure around the snow throwing hole 6 needs to be strengthened, which leads to an increase in construction cost. Since it is necessary to increase strength and rigidity, the weight is increased, and a crane car or the like is required for handling the same.

On the other hand, if the snow throwing port 6 is constructed to be relatively small, the construction cost of the snow throwing port 6 and the weight of the iron lid 7 can be expected to be reduced, but the snow throwing around the snow throwing port 6 is expected. It is likely to cause the scattering of water and then require manual labor for processing.

[0010] The snow throwing procedure by the dump truck 8 to the snow throwing mouth 6 is performed as shown in Fig. 8 ~.
Prior to the snow throwing by, the iron cover 7 is opened as follows by a crane truck (not shown). That is, first, a general vehicle is closed to the first traveling zone 5A in which the snow throwing mouth 6 is installed, and then the crane vehicle is advanced along the first traveling zone 5A to the vicinity of the snow throwing mouth 6 and then the vehicle stop 9 Is taken out from the road shoulder 1A or the like and placed near the front wall of the snow throwing port 6. After that, the iron lid 7 is removed from the snow throwing port 6 by a crane vehicle and placed in a proper place around the snow throwing port 6.

Next, the snow dump truck 8 is advanced to the side of the snow throwing port 6 along the second running zone 5B adjacent to the first running zone 5A where the snow throwing port 6 is arranged, The lane is changed to the traveling zone 5A, the first traveling zone 5A is slightly moved straight, and then the vehicle is temporarily stopped.

After the snow-covered dump truck 8 is retracted to a position near the snow throwing port 6 and stopped, the loading platform 8A is erected and snow is thrown to the snow throwing port 6, and after the snow throwing is finished, the loading platform 8A is lowered. If the snow dump truck 8 throws snow only once, the crane cover is used to return the iron lid 7 to the top of the snow throwing port 6 to close it, and then the car stop 9 is put away at a proper position such as the road shoulder 1A.
In addition, when continuing the snow throwing, the snow throwing opening 6 is continuously opened, and the snow dumping similar to the above is repeated by the other dump truck 8.

After the completion of the snow throwing, the empty dump truck 8 is advanced along the first traveling zone 5A, while the suspension of the first traveling zone 5A is released to restore the normal traveling state.

Although not shown, Japanese Patent Laid-Open No. 3-156,
Japanese Patent No. 041 discloses an opening / closing operation of a groove lid swingably provided in an opening provided at a proper interval in a snow drift groove for snow removal installed on a road shoulder portion of a road in a cold region. What is made operable through an operating mechanism or a fluid pressure operating mechanism is disclosed in Japanese Utility Model Laid-Open No. 1-176187, in which a cross girder for preventing a worker from falling is provided at an opening of a snow throwing opening to a snow throwing groove. In addition to providing a connecting girder and the like, the top of the opening is made of a light material such as FRP material, aluminum material, etc., and a flat plate lid with a non-slip surface such as a convex portion formed on the surface can be swung with a hinge etc. There is a description of each of the snowdrift cover of the snow drift groove provided in the above.

[0015]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The snow cover opening / closing lid structure disclosed in Japanese Patent No. 332 and Japanese Patent Application Laid-Open No. 4-202,926 has anti-freezing measures for the lid, and therefore expects a corresponding anti-freezing effect and ease of handling. Although it is possible to open and close the lid, not only is it related to the structure of a small snow cover opening and closing, but it also takes time and effort to open and close the lid because it needs to be opened and closed manually or by a mobile crane. However, there is a tendency to obstruct long-term traffic, and in the case where the snow throwing opening 6 is provided in the first traveling zone 5A of the conventional example shown in FIG. Place the removed heavy iron lid 7 in a proper place around the snow throwing mouth 6, and then put the bollard 9 near the front wall of the snow throwing mouth 6, and then, as shown in FIG.
From the time when the vehicle travels alongside B to the side of the snow throwing mouth 6 until the lane is changed to the first running zone 5A, the passage of the second running zone 5B where the snow throwing mouth 6 is not installed is restricted.

The direction of the snow-covered dump truck 8 whose lane is changed from the second traveling zone 5B to the first traveling zone 5A is the first traveling zone 5
After the dump truck 8 is linearly traveled to the direction A, therefore, the first traveling zone 5A until the snow accumulation dump truck 8 is considerably separated from the front end of the snow throwing mouth 6.
After the vehicle is run, the vehicle is temporarily stopped, and then the snow dump truck 8 is retracted to the snow throwing opening 6 and then stopped, as described above. Change the lane from 5B to 5A in the 1st lane, and make a snow throw 6
The travel distance of the snowy dump truck 8 and the retreat distance to the direction become relatively long.

It takes time to return the iron lid 7 removed to the snow throwing opening 6 by the crane wheel after the snow is thrown up by raising the cargo bed 8A, and it is necessary to secure the operation space by the crane wheel. In addition, the safety around the opening snow cover 6 is ensured and the iron cover 7 is removed from the snow cover 6 by removing the iron cover of the snow cover 6 with a crane. -It is necessary to block the first lane 5A for a considerable amount of time before the vehicle is blocked, which may lead to traffic congestion.

Further, the snow drift groove 3 in which the snow throwing port 6 is installed is
A sewage drain for sewage treatment, which is mainly buried underground in urban areas, is often used. In this case, the odor of sewage flowing through the sewage drain or running water ditch is a large snow outlet installed in the ditch. 6 always rises, and in particular, a large amount of odor is released to the surroundings from the opened snow throw opening. Furthermore, even when the snow throwing port 6 is provided in a drainage groove for hot drainage or the like that retains high heat energy after use, such as a heating / cooling device mainly installed in an urban area, an odor is generated by the opening of the snow throwing port 6. Etc. may rise and may be released in the same manner as above.

A large number of buses are placed in and around the snow throwing port 6 on the snow melting tank installed in the basement of the plaza such as a bus terminal, and a space for entering and exiting the dump truck 8 for snow throwing is secured. If a dump truck or a crane truck stops for a long time around the snow throwing port 6, it will hinder the traffic of general vehicles. Further, since the snow drift groove 3, the snow melting tank, etc. are quite large, and the snow throwing port 6 at the top thereof is usually provided at a considerably high position, the opening from the snow throwing port 10 to the start of snow throwing In the meantime, the snow throwing worker may accidentally fall into the snow throwing port 6 that is opened and fall into the deep bottom of the snow drift groove 3, the snow melting tank or the like, which may cause personal injury. There wasn't.

[0020] Further, in the snow drift groove installed on the shoulder portion of the road in the cold district described in the above-mentioned Japanese Patent Laid-Open No. 3-15604, the rocker swings at an opening installed at an appropriate interval. In the case where the opening / closing operation of the possible groove lid is operated by the manual operation mechanism or the fluid pressure operation mechanism, the transmission mechanism for the opening / closing operation of the groove lid is located inside the snow throwing inner wall. Since it is provided, there is a tendency to prevent the flow of snow throwing down, and a horizontal girder for preventing a worker from falling at the opening of the snow throwing mouth to the snow throwing groove described in the above-mentioned Japanese Utility Model Laid-Open No. 1-176187. Since the connecting girders and the like are provided, there is a problem that the horizontal girders and the connecting girders may be prevented from falling snow to the snow throwing mouth.

Further, in the opening / closing operation mechanism of the groove cover of the snow drift groove for snow removal described in the above-mentioned Japanese Patent Laid-Open No. 3-15604, it can be operated via a manual operation mechanism or a fluid pressure operation mechanism. In addition, in the cover for the snow throwing mouth of the snow drift groove described in Japanese Utility Model Laid-Open No. 1-176187, the opening / closing lid of the opening of the snow throwing mouth to the snow throwing groove is made of a lightweight material such as FRP material. Therefore, the operability of each can be expected to be improved, and in the case of the snow drift cover of the snow drift groove described in the above-mentioned Japanese Utility Model Laid-Open No. 1-176187, the lateral side provided at the opening is provided. While the girders and connecting girders can be expected to prevent workers from falling, the horizontal girders, connecting girders, and the interlocking part of the operating mechanism of the opening / closing lid projecting inside the opening can be thrown into the opening. There were some problems, such as the inability to prevent falling snow.

In view of the problems in the conventional example, the present invention provides a snow throwing port 10 having a substantially rectangular shape in plan view on the upper part of the snow throwing region 2 such as the snow drift groove 3 and the snow melting tank, and the snow throwing is performed. Mouth 10
A first recess 20 is provided at the top of the rear wall 11 that opens to the side of the snow throwing port 10 and the bottom of the rear recess 11 descends with a steep slope, and the power of the torque actuator 32 or the electric motor 51 is provided in the first recess 20. By providing a first horizontal shaft 21 which is rotationally driven in the forward and reverse directions by a driving means, and attaching a base portion 23B of a plate-shaped hatch 23 that opens and closes the snow throw port 10 to the first horizontal shaft 21, the snow throw port is provided. The plate-shaped hatch 2 is provided on the inside of the top of 10 without providing a member for preventing the flow of snow.
3, the side hatches 27, 27 are provided below both side portions 23C, 23D of the plate-like hatch 23 to secure the safety around the snow throwing port 10 to be opened. Balance weights 44 for constantly closing the central portion 10A of the mouth 10 and fall prevention plates 43, 4 with 44
Due to the provision of 3, the balance weights 44, 44 will catch even if the snow throwing worker falls to the snow throwing opening 10 that opens before the start of snow throwing to the snow throwing opening 10. It is possible to prevent the snowfall groove 3 below the snow thrower 10 from falling into the snow melting tank or the like, and to throw the snow throwing guide plate 14C inside the front wall 14 of the snow thrower 10 and the first recess 20. Snow guide plate 20
A and heaters 14D, 20D and 23AB for heat insulation of appropriate shape are provided around the floor plate 23A of the plate-like hatch 23, so that there is no fear of freezing to the plate-like hatch 23, etc. It is intended to provide a power opening / closing type snow throw hatch that can ensure operability and high safety.

[0023]

[Means for Solving the Problems] A snow throw opening 10 having a substantially rectangular shape in a plan view is provided above a snow throw area 2 such as a snow drift groove 3 or a snow melting tank, and a top portion of a rear wall 11 of the snow throw opening 10 is provided. To the snow thrower 10
A first concave portion 20 which is opened to the side and whose lower portion descends steeply is provided, and the first concave portion 20 is rotationally driven in forward and reverse directions by a power driving means such as a torque actuator 32 or an electric motor 51. A power open / close type snow throwing hatch in which a horizontal shaft 21 is provided, and a base portion 23B of a plate-like hatch 23 for opening and closing the snow throwing port 10 is attached to the first horizontal shaft 21, and both left and right sides of the plate-like hatch 23 are provided. Located below the left and right side portions 23C and 23D of the plate-shaped hatch 23 in the upright state and the side walls 12 and 13 of the snow throwing mouth 10 below the portions 23C and 23D, and The snow fence 10 is provided with side fences 27, 27 which occupy positions slightly inside the side walls 12, 13, and further, a snow throwing guide plate 14C inside the front wall 14 of the snow throw mouth 10, 1 recess 20 snow throwing guide plate 0A and floor plate 23A around the plate-like hatch 23, as appropriate shape of the insulation heater 14D, 2
0D and 23AB are provided.

Left and right side portions 23C of the plate-like hatch 23,
On the lower side of 23D, under the right and left sides 23C and 23D of the plate-shaped hatch 23 in the standing state and the snow throwing port 1
The side fences 27, 27 which are located between the side walls 12, 13 of 0 and occupy a position slightly inside the side walls 12, 13 of the snow throwing port 10 are provided.

A second recess 40 is formed below the first recess 20 at the center of the rear wall 11 and the front wall 14 of the snow throwing port 10.
A fall prevention plate that forms 40 and provides second horizontal shafts 41, 41 in the second recesses 40, 40, and closes the central portion 10A of the snow throwing port 10 inside the second horizontal shafts 41, 41. 43, 43 are respectively provided with balance weights 44, 44 outside the second horizontal shafts 41, 41 for keeping the fall prevention plates 43, 43 in a horizontal state, and the balance weights 43, 43 are attached to the fall prevention plates 43, 43. The fall prevention plates 43, 43 are automatically rotated downward by a load of a predetermined value or more.

A snow throwing guide plate 14C is provided on the inside of the front wall 14 of the snow throwing mouth 10, and the rear wall of the first recess 20 of the snow throwing mouth 10 has a rear end of a base portion 23B of the plate-like hatch 23. 20A, which is opposed to the turning locus 23BA and whose distance from the turning locus 23BA is gradually larger from the upper part toward the lower part, and the inclined part whose lower end reaches the rear wall 11 of the snow throwing port 10. 20A is provided with a snow throwing guide plate 20A.

Around the snow throwing guide plate 14C on the inside of the front wall 14 of the snow throwing port 10, the snow throwing guide plate 20A of the first recess 20 and the floor plate 23A of the plate-like hatch 23, a heat insulating heat insulator having an appropriate shape is provided. 14D, 20D and 23AB are provided.

[0028]

Since the present invention has the above-described structure, the snow dump truck 8 is provided in the snow drift groove 3, the snow throwing area 2 such as the snow melting tank.
After traveling over the snow throwing hole 10 having a substantially rectangular shape in plan view constructed above and advancing along the traveling zone, by the power driving means such as the torque actuator 32 or the reversible motor 51, via the first horizontal shaft 21. The plate-shaped hatch 23 is erected vertically, and then the loading platform 8A is erected and snow is thrown to the snow throwing port 10. At this time, if a part of the snow throwing or the like intrudes into the first recess 20 provided with the drive unit of the power opening / closing type snow throwing hatch, the snow is automatically sent to the snow throwing port 10 side along the steeply inclined bottom wall. Fall. Further, after the snow is thrown, the plate-shaped hatch 23 is laid down by the power driving means to close the snow throwing port 10 and the traveling zone is returned to the normal traveling zone state.

Left and right side portions 23C, 23 of the plate-shaped hatch 23
Since the side fences 27, 27 located inside the left and right side walls 12, 13 of the snow throwing hole 10 are provided on the lower side of D, the standing plate hatch 23 and the side fences 27, 2 are provided.
The surroundings of the opened snow throwing mouth 10 are surrounded by 7 and the snow throwing mouth 1 opened to prevent the snow throwing due to the standing of the loading platform 8A of the dump truck 8 from being scattered around the snow throwing mouth 10
Prevents snow throwers from falling to zero.

The second of the rear wall 11 and the front wall 14 of the snow throwing mouth 10
The balance weight 4 that always closes the central portion 10A of the snow throwing port 10 on the second horizontal shafts 41, 41 of the recesses 40, 40.
Since the fall prevention plates 43 and 43 with the numbers 44 and 44 are provided, the fall prevention plates 41 and 41 are provided at the time of normal snow throwing to the snow throwing port 10.
Falls vertically against the balance weights 44, 44 to smoothly drop the snow throwing below the snow throwing mouth 10, and temporarily, the snow throwing mouth 10 opened before the start of snow throwing. Even if the snow throwing worker falls to the snow throwing worker, the fall prevention plates 43, 43 maintain the horizontal state by the balance weights 44, 44 under the load of about the weight of the snow throwing worker. 10
Block and receive.

A snow throwing guide plate 1 inside the front wall 14 of the snow throwing mouth 10.
4C, since the snow throwing guide plate 20A of the first recess 20 and the floor plate 23A of the plate-like hatch 23 are provided with heat-insulating heaters 14D, 20D, and 23AB of an appropriate shape, the plate-like hatch 23 and its driving means. Freezing of surrounding areas is prevented.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the power opening / closing type snow throwing hatch according to the present invention will be described below with reference to the attached FIGS.

FIG. 1 is a schematic side view of a power opening / closing type snow throwing hatch according to an embodiment of the present invention, showing a portion of a snow throwing port 10 in a standing state of the plate hatch 23. The torque actuator 32 of FIG. 2 is removed and shown, and FIG. 1 corresponds to the AA arrow view of FIG. 2 described later. FIG. 2 is a schematic plan view of the same, in which the positions of the first bearing 22, the torque actuator 32, etc. are indicated by broken lines. FIG. 3 is a schematic vertical cross-sectional explanatory view of a main part of the plate-shaped hatch 23 in the lying state, which corresponds to a view taken along the line BB of FIG.

FIG. 4 is a schematic explanatory view of a hydraulic circuit for driving a torque actuator 32 as a power driving means of the first horizontal shaft 21 of the plate-shaped hatch 23 by a reversible pump 33, and FIG. 5 is the torque actuator. 32 is another hydraulic circuit 4 for driving the pressure oil from the pump 46 via the direction switching valve 49.
7, a torque actuator 32 is shown by a symbol in FIG.

FIG. 6 is a schematic explanatory view of a drive structure of the first horizontal shaft 21 of the plate-shaped hatch 23 by the reversible motor 51, and FIG. 7 is a view showing the opening of the snow hatch 10 in which the plate-shaped hatch 23 is erected. FIG. 8 is a schematic perspective explanatory view of a snow throwing procedure by the dump truck 8.
Is for guiding the dump truck 8 to the snow throw opening 10 provided with the power opening / closing type snow throw hatch of the present invention built in the first traveling zone 5A and the snow throw opening 6 provided with the iron cover 7 of the conventional example, snow throwing procedures, etc. It is a model comparison explanatory view of.

In the figure, 1 is a road surface, 1A is a road shoulder, 2 is a snow throwing area in which a snow drift groove 3 or the like is provided, and 5A to 5C are first to first areas.
Third travel zone, 8 is a dump truck, 8A is a loading platform, 8B is a tire, 9 is a car stop, 10 is a snow throwing hole constructed in a proper place in the snow throwing area 2, 10A is a central portion of the snow throwing hole 11, 11-14. Is the rear wall, the right wall, the left wall and the front wall of the snow throwing port 10, 12A, 1
3A is a hatch receiver provided on the left and right side walls 12, 13 of the snow throwing port 10. The hatch receivers 12A, 13A are on the left and right side walls 12,
It is spaced from the top of 13 downward by a distance h.

Attach the hatch receivers 12A and 13A to the side walls 1
If it is installed on the entire width of the inside of 2 and 13, the plate-shaped hatch 2
While the entire length of the lower portions of both sides of No. 3 is supported, there is a possibility that freezing may occur in the total length of the abutting portions of both, so that the I-beam 25 and the peripheral portion 25A of the U-shaped beam portion as shown in the figure. If only the lower part is used, the freezing factor will be reduced accordingly.

A hatch receiver 14B below the end portion 23E of the plate-shaped hatch 23 may be provided inside the front wall 14 of the snow throwing port 10 at a lower position spaced from the top surface by the same distance h. it can. This hatch receiver 14B is the front wall 1 of the snow throwing mouth 10.
It is preferable to form a short length only on both the left and right sides of the No. 4 or in the vicinity of both sides thereof so as not to hinder the snow throwing.

Reference numeral 20 designates first recesses 20 and 2 provided in the rear wall 11.
Reference numeral 0A denotes a snow throwing guide plate provided along the rear wall of the first recess 20, 20AA denotes an arcuate portion of the snow throwing guide plate 20A, and this arcuate portion 20AA is a rear end of the base portion 23B of the plate-like hatch 23. The base portion 23B of the plate-like hatch 23, which is arranged to face the moving locus 23BA and is configured to gradually widen the distance from the rotation locus 23BA from the upper end to the lower end of the arcuate portion 20AA, and to fall down.
Snow or the like falling from the gap between the rear end and the top of the rear wall of the first recess 20 formed in the rear wall 11 of the snow throwing port 10, and hence the top of the arcuate portion 20AA of the snow throwing guide plate 20A, is generated. When the arcuate portion 20AA and the plate-shaped hatch 23 are raised, it is prevented that the gap between the rear portion of the base portion 23B and the rear end of the plate-shaped hatch 23 is pressed.

Reference numeral 20AB designates the arcuate portion 20 of the snow throwing guide plate 20A.
At the inclined portion following AA, the lower end of the inclined portion 20AB reaches the inner surface of the rear wall 11 of the snow throwing mouth 10. Reference numeral 20D is a heater having an appropriate structure, which is provided inside both the arcuate portion 20AA and the inclined portion 20AB of the snow throwing guide plate 20A and has excellent moisture resistance and water resistance.

Reference numeral 21 denotes a first horizontal shaft provided in the first recess 20 in the left-right direction of the snow throwing port 10, and reference numerals 22 and 22 denote both end portions of the first horizontal shaft 21 supported on both side wall portions of the first recess 20. First to do
It is a bearing. The plate-shaped hatch 23 has a rectangular shape in plan view which is substantially the same as the top opening of the snow throwing mouth 10 and has a slightly smaller diameter than that of the top opening, and its base portion 23B is attached to the first horizontal shaft 21. 23A is an iron floor plate of the plate-shaped hatch 23, 23AA is a reinforcing rib provided inside the floor plate 23, and 23AB is a floor plate 23A.
It is a heater having a proper structure which is provided in the lower part of and has excellent moisture resistance and water resistance.

23C, 23D and 23E are the left side part, the right side part and the end part of the plate-like hatch 23, and 24 is the plate-like hatch 23.
Pavement layer provided on the upper surface of the floor board 23A of the
3 is the thickness including the pavement layer 24, h is the distance between the tops of the left and right side walls 12, 13 of the snow outlet 10 and the hatch receivers 12A, 13A, and this distance h is almost the same as the thickness H of the plate-like hatch 23. Match.

Reference numerals 27 and 27 denote side fences provided below the left and right side portions 23C and 23D of the plate-like hatch 23, which are fan-shaped with a central angle of about 90 ° and which can prevent snow spills and scattering. A pipe material or the like is welded so as to form a fine mesh structure, and is constructed as shown in FIG.

The side fences 27, 27 block the lower sides of both side portions 23C, 23D of the plate-shaped hatch 23 in the standing state and the top surfaces of both side walls 12, 13 of the snow throwing mouth 10, while the plate-shaped hatch 23 is kept closed. Side walls 1 of the snow throwing port 10
It is inserted so as to occupy the inside of 2, 13.

As a constituent material of the side fence 27, a narrow steel plate can be used instead of the above-mentioned pipe material, and in particular, a straight narrow steel plate is used to form a so-called cobweb shape. It can also be configured to. Further, the side fence 27 may be formed of a fan-shaped thin steel plate, or may be formed by arranging reinforcing ribs at appropriate intervals on the peripheral portion and / or the side surface thereof, particularly on the outer side thereof.

27A and 27A are left and right side fences 2.
The lower part of the front edge of 7, 27, 28 is a front fence, and this front fence 28 is a side fence 27, 2 on the left and right.
The lower portions 27A, 27A of the front edge of No. 7 are formed by welding several pipe materials or narrow steel plates arranged at required intervals. 29,
Reference numeral 29 denotes a steady rest whose end is attached to the lower side of the center of the edge of the floor plate 23A and the peripheral portions of the side fences 27, 27 by welding or the like. The steady rest 29 is located below the snow throwing toward the standing plate-shaped hatch 23. It is provided at the corner of the plate-shaped hatch 23 so that it cannot be prevented from falling.

Although not shown, the left and right side fences 27, 27 are partially formed, for example, 1 / n of the center side.
Although it is possible to omit about 2 ends, in order to secure its strength and safety, in the state where the plate hatch 23 is erected, the plate hatch 23 and both side walls 12 of the snow throwing port 10,
It is desirable to configure so as to partition the entire area between the top surface of 13 and.

The outer edge portions of the left and right side fences 27, 27 may be formed in a circular shape as shown in the drawing, or may be formed in a polygonal shape with a small number of sides, and are formed in a net shape as long as the strength can be secured. You can also do it.

Reference numeral 31 is a coupling having an appropriate structure such as a gear coupling, and 32 is a torque actuator capable of rotating in the forward and reverse directions as a power driving means.
The second output shaft is connected to the first horizontal shaft 21 via a coupling 31.

The torque actuator 32 mounts an output shaft 32A having a spline 32B on a casing 32D so that the output shaft 32A is prevented from moving in the axial direction, and the spline engaged with the spline 32B is placed inside. A cylindrical piston 32C is mounted so as to be movable in its axial direction, and a large thread portion of the lead formed on the outside of the cylindrical piston 32C and a lead formed on the inside of the casing 32D. It is configured by engagement with a large threaded portion.

The torque actuator 32 is rotatably supported by the reversible pump 33 by the pressure oil supplied and discharged through the hydraulic circuit 34 so that the cylindrical piston 32C can be rotated to a fixed position in the casing 32D. Spline 32 of output shaft 32A
It is reciprocally driven in the axial direction along B.

Due to the axial reciprocating movement of the cylindrical piston 32C, the threaded portion having a large lead outside the cylindrical piston 32C is engaged with the threaded portion having a large lead inside the casing 32D. This causes the cylindrical piston 32C to rotate in either forward or reverse directions. Due to the rotation of the cylindrical piston 32C,
The output shaft 32A including the spline 32B that engages with the spline on the inner side of the spline 32A also simultaneously rotates in either the forward or reverse direction. This rotation is transferred via the coupling 31 to the first horizontal shaft 2
It reaches 1 and rotates in the same direction.

The reversible pump 33 is, for example, the snow throwing port 1 described above.
Around 0, it is installed in an appropriate place such as underground on the road shoulder 1A beside the first traveling zone 5A. Reference numerals 35 and 36 are relief valves of the hydraulic circuit 34, and 37 is a normal rotation, neutral rotation and reverse rotation (L, L) of the reversible pump 33.
(N, R) with the operation switch for selecting and operating the snow throwing port 1
It is installed in a proper place such as the road shoulder 1A around 0.

Reference numerals 38 and 39 denote the first bearing 2 of the first horizontal shaft 21.
2, 22 and a pit cover that covers the drive parts of the torque actuator 32, etc., and is opened when this device is mounted, inspected and adjusted.

Reference numerals 40 and 40 denote second recesses provided in the rear wall 11 and the front wall 14 of the central portion 10A of the snow throwing port 10, respectively.
0 and 40 are provided at the same height below the first recess 20. 41, 41 are second horizontal shafts provided in the second recesses 40, 40, 43, 43 are bases fixed so that they are located inside the second horizontal shafts 41, 41 (on the center side of the snow throw port 10) The plates, 44, 44 are balance weights provided outside the second horizontal shafts 41, 41. The balance weights 44, 44 keep the fall prevention plates 43, 43 always at the position indicated by the alternate long and short dash line in FIG. While maintaining and closing the central portion of the snow throwing port 10, if a snow throwing worker or the like falls, the fall preventing plate 43,
Even if it abuts against 43, it does not rotate under such a light load.
However, due to normal snow throwing due to the standing of the loading platform 8A of the dump truck 8, the snow is not immediately lowered to the position indicated by the solid line in FIG. 1 and does not hinder the snow throw.

(Operation of Embodiment) The snow-covered dump truck 8 is stopped after passing through the snow throwing mouth 10 constructed in the first traveling zone 5A. The travel distance of the snow dump truck 7 along the traveling line of the snow dump truck 10 over the snow throwing mouth 10 is not only visible to the driver of the dump truck 8 traveling in the first traveling zone 5A but also accompanied by the lane change. The direction of the traveling vehicle body is the first traveling body 5A.
Since it is not necessary to adjust to the above, it becomes considerably shorter than the traveling distance along the traveling line around the snow throwing port 6 of the snow dump truck 8 of the conventional example. In addition, in FIG. 8, the relationship is shown as a difference in the shape of the traveling line and the shape of the traveling line, and the relationship of the difference between the traveling distances of the both is shown by the length of the traveling line and.

Next, the rear wheels 8B of the snow dump truck 8
A car stop 9 is placed between the front wall 14 and the front wall 14 of the snow throwing port 10 to prevent the dump truck 8 from falling to the snow throwing port 10 due to careless retreat.

The snow-covered dump truck 8 is retracted to the front wall 14 side of the snow throw opening 10 and stopped. Next, the reversible pump 33 is rotated in the normal direction by selecting the normal rotation of the operation switch 37,
The case of the torque actuator 32 via the hydraulic circuit 34
Cylindrical piston 32C by sending pressure oil to the left side of single 32D
Is pushed to the right, the threaded portion with a large lead is engaged with the outside of the cylindrical piston 32C and the inside of the casing 32D,
The cylindrical piston 32C moves to the right while rotating forward.

Due to the normal rotation of the cylindrical piston 32C, the output shaft 32A rotates in the normal direction via the spline 32B which engages with the spline inside the cylindrical piston 32C.
The 1st horizontal shaft 21 connected via the coupling 31 rotates normally, the plate-shaped hatch 23 which attached the base part 23B to the 1st horizontal shaft 21 stands up, and opens the snow throw opening 10.

Next, the loading platform 8A is raised and the snow throwing port 10
To snow. At this time, the plate-shaped hatch 23 that stands upright on the rear wall 11 side of the snow throwing port 10 causes the left and right side walls 1 of the snow throwing port 10 to rise.
The fences 27 and 27 on the left and right sides on the 2 and 13 side
Since the front wall 14 side is surrounded by the front fence 28, the snow throwing operator around the snow throwing opening 10 is prevented from accidentally falling into the open snow throwing opening 10.

Even if the snowfall operator or the like falls to the opened snowfall mouth 10 between the opening of the snowfall mouth 10 due to the standing of the plate-shaped hatch 23 and the start of snowfall, the balance weight 44,
A fall prevention plate 43 whose horizontal state is always maintained by 44,
It is received by 43, and the falling of the snow throwing port 10 is prevented.

Snow is thrown upright by the loading platform 8A of the dump truck 8 inside the floor 23A of the plate-shaped hatch 23 (right side in FIG. 1) and the side fences 27 on the left and right sides thereof.
A member that surrounds the top opening of the snow throw mouth 10, such as 27 and the front fence 28, is guided downward, and snow is thrown to the snow throw mouth 10 without scattering around the snow throw mouth 10.

The cargo bed 8A is attached to the fall prevention plates 43, 43 which are installed in the central portion 10A of the snow throwing port 10 and always maintain a horizontal state.
Fall prevention plates 43, 43 when snow throwing due to standing up
But against the balance weights 44, 44, the second horizontal axis 4
By turning around 1, 41 to the solid line positions 43, 43 in FIG. 1, the central portion 10A of the snow throw opening 10 is opened, and the snow throw falls to the running water groove 3 below.

After the snow is thrown, the cargo bed 8A is laid down and the reversible pump 33 is selected by selecting the reverse rotation of the operation switch 37.
Is reversed and the torque actuator is connected via the hydraulic circuit 34.
The cylindrical piston 32C of the rotor 32 is returned to the left side for reverse rotation, and the output shaft 32A is reversely rotated through the spline 32B or the like to reverse the first horizontal shaft 21 and the plate-like hatch 23 so that the snow throw port 10 is opened. Block. Then, stop the car 9 at the shoulder 1A.
Etc., and put the first traveling zone 5A back into the normal traveling zone posture.

The empty dump truck 8 is moved to the first traveling zone 5
Run along A. If there is any other snow dump truck 8 that requires snow throwing, the plate-like hatch 23 is opened / closed by the operation of selecting the forward / reverse points of the operation switch 37, the snow dump truck 8 is moved forward / backward, and snow is thrown. The progress of the empty dump truck 8 is repeated.

The guide plate 1 of the front wall 14 of the snow throwing mouth 10
Heater 14D on the inside of 4C, heater 20D on the inside of guide plate 20A having arcuate portion 20AA and sloped portion 20AB on the rear wall of first recess 20, heater 23AB on the bottom of floor plate 23A of plate hatch 23, etc. In order to prevent the occurrence of freezing in the portion by energizing and keeping the temperature in the cold, the smooth opening and closing operability of the plate-like hatch 23 is secured.

The width of the fall prevention plates 43, 43 provided on the second horizontal shafts 41, 41 is set to be equal to the width of the left and right sides of the plate-like hatch 23 provided on the first horizontal shaft 21 below the two sides 23C, 23D. If it is configured to be narrower than the space between the side fences 27, 27, both side portions of the fall prevention plates 43, 43 and the snow throwing port 1
A gap is created between the side walls 12 and 13 of the snow cover 0, and in this case, the central portion 10A of the snow throw port 10 cannot be sealed by the fall prevention plates 43 and 43.

However, since this gap is narrow enough to allow the side fence 27 to pass through, it is unlikely that an operator or the like who has fallen onto the fall prevention plates 43, 43 in the horizontal state will fall downward from this gap. Absent.

On the other hand, if the widths of the fall prevention plates 43, 43 are made slightly narrower in this way, the second horizontal shafts 42, 42 for mounting the bases of the fall prevention plates 43, 43 are attached to the first horizontal shaft 21. Since it can be installed at a close position, that is, at a position close to the top of the snow throwing mouth 10, the fall prevention plates 43, 43 installed inside the snow throwing mouth 10 can be easily inspected, and also fall into the open snow throwing mouth 10. The worker or the like can be retained at a position near the top without dropping to the central portion 10A of the snow throwing mouth 10.

Although not shown, the car stop 9 is first
It is configured to be able to move up and down with respect to the road surface 1 of the traveling zone 5A, and the car stop 9 is projected onto the road surface 1 prior to the standing up of the plate hatch 23 by the torque actuator 32, while the plate hatch is being projected. Snowfall 10 due to the lodging of 23
If the vehicle stop 9 is configured to be retracted below the road surface 1 after the vehicle is closed, the vehicle stop 9 can be pulled over the road shoulder 1A prior to the snow throwing work.
To take out from the surroundings and install it near the front wall 14 of the snow throwing mouth 10, or remove from the vicinity of the front wall 14 of the snow throwing mouth 10 after the snow throwing and return it to a proper place around the road shoulder 1A and store it. Can be omitted.

(Modified Example of Hydraulic Circuit) In FIG. 5, the torque actuator 32 is driven by the pump 46 driven in a predetermined direction by turning on the start switch 48, via the hydraulic circuit 47 having the direction switching valve 49. FIG. 5 is a schematic explanatory view of another hydraulic circuit (modification example). In FIG. 5, the torque actuator 32 is shown by a symbol, and the relationship with the plate-like hatch 23 is also schematically shown.

A start switch 48 is installed in a proper place such as the road shoulder 1A around the first traveling zone 5A where the snow throwing mouth 10 is installed, and after the start of the hydraulic pump 46 by turning on the start switch 48, it is installed at the same position. The direction switch valve 49 is switched to either forward, stop, or reverse by selecting either forward, neutral, or reverse (L, N, R) of the operation switch 50, and the hydraulic circuit 4
The direction in which pressure oil is sent to the torque actuator 32 is switched via 7 and its output shaft (see 32A in FIG. 4) is driven in a predetermined direction, via the coupling 31, the first horizontal shaft 21 and the like. The plate hatch 23 is undulated. The rest of the structure and operation are the same as in the above-mentioned embodiment.

(Driving Circuit by Reversible Motor) FIG. 6 shows the configuration of the reversible pump 34 of FIG. 4 or the direction switching valve 49 of FIG.
The first horizontal shaft 21 is normally and reversely rotated through the torque actuator 32 to replace the power drive structure for opening and closing the plate-shaped hatch 23, and normal, neutral, and reverse (L, N, R) are selectively operated. FIG. 3 is a schematic explanatory view of a power drive structure using a reversible motor 51 which selectively rotates forward and backward by an operation switch 52. The output shaft of the reversible motor 51 is a speed reducer 53 and a coupling 54.
Is connected to the first horizontal shaft 21 via a plate-like hatch 23.
Ups and downs.

According to the drive structure shown in FIG. 6, the reversible motor 51, the speed reducer 53, the coupling 54, etc. are selected by selecting the forward rotation of the operation switch 52 installed at a proper position such as the road shoulder 1A around the snow throwing port 10. The first horizontal shaft 21 is rotated in the forward direction to raise the plate-shaped hatch 23 to open the snow throwing mouth 10, and the reversing motor 51 is reversed by selecting the reverse rotation of the operation switch 52 to reduce the speed. The plate-shaped hatch 23 is laid down horizontally via 53, the coupling 54 and the like to close the snow throwing port 10. The rest of the structure, operation and the like are almost the same as those in the above embodiment.

[0075]

Since the present invention has the above-mentioned structure and operates, the following effects can be obtained.

(1) Snow drift area 3, snow drift area 2 such as a snow melting tank
After stopping the dump truck 8 traveling over the snow throwing mouth 10 constructed in the first running zone 5A of the vehicle, the torque actuator 32 or the reversible motor 51 is powered. The plate-shaped hatch 23 is erected by the driving means to open the snow throwing port 10, and thereafter, the snow is thrown by the erection of the loading platform 8A, and after the snow-casting is finished, the plate-shaped hatch 23 is laid down by the power driving means. Since the snow throw opening 10 is closed and returned to the normal first traveling zone 5A, it is not necessary to open and close the iron lid of the snow throw opening with a crane vehicle or the like as in the conventional example, and the dump truck 8 Each time the snow is thrown, the snow throwing mouth 10 can be opened and closed simply and quickly to perform the snow throwing, and the first traveling zone 5A does not need to be closed for a long time unlike the conventional example. There is no need to restrict traffic in the second driving zone 5B.

(2) Since the inside of the floor plate 23A of the plate-shaped hatch 23 in the open state of the snow throwing mouth 10 receives the snow throwing from the cargo bed 8A and guides it toward the opening side of the snow throwing mouth 10, a required amount of snow throwing is performed. It is possible to suppress the possible rearward expansion of the snow throwing mouth 10 and to make the opening area of the snow throwing mouth 10 smaller than the conventional example, and the plate-like hatch 23 can also be made narrower than the iron cover 7 of the conventional example, and, by extension, A plate-shaped hatch 2 with the required strength and rigidity
3 can be constructed in a light weight, and the driving means thereof can be constructed in a relatively small size.

(3) Since the bottom wall of the first concave portion 20 provided on the top of the rear wall 11 of the snow throwing mouth 10 and open to the side of the snow throwing mouth 10 is formed so as to descend steeply, Even if a part of the snow throws into the second concave portion 20, the first concave portion 20
It smoothly flows down to the side of the snow throwing mouth 10 along the steeply sloping bottom wall.

(4) Both sides 23A of the plate-shaped hatch 23
Since the side fences 27, 27 are provided on the lower side of C, 23D, it is possible to prevent the snow throwing around the snow throwing port 10,
In addition, the front edge lower portion 27A of the side fences 27, 27
Since the front fence 28 is provided in the floor board 2 of the plate-like hatch 23 for standing up the snowfall that falls when the loading platform 8A stands up.
By cooperating with the inside of 3A, the snow can be smoothly guided to the snow throwing mouth 10, and by extension, the snow throwing to the adjacent second traveling zone 5B can be prevented while the snow throwing work is continued.

(5) In addition to providing the second recess 40 in the center of the front and rear walls 11, 14 of the snow throwing port 10, the second recess 40
The second horizontal shafts 41, 41 of the
Fall prevention plates 43, 43 for closing 0A, and a balance weight 4 for always keeping the fall prevention plates 43, 43 horizontal.
4 and 44 are provided, the fall prevention plates 43, 43 due to the collision of the snow throw during normal snow throwing to the snow throw opening 10.
Immediately descends vertically in opposition to the balance weights 44, 44 to ensure smooth passage of the snow throwing mouth 10 of the snow throwing, and even if the plate-like hatch 23 stands up, 10
Before the start of snow throwing on the snow, the snow thrower 1 opens the snow
Even if it accidentally falls to 0, the horizontal fall prevention plate 43,
There is no risk of falling under the snow throwing port 10 as it is received by 43.

(6) Second of the central portion 10A of the snow throwing mouth 10
Normally closed balance weights 44, 44 on the horizontal shafts 41, 41.
Since the attached fall prevention plates 43, 43 are provided, the plate-like hatch 23
Immediately after opening the snow throwing mouth 10 by standing up
Until the start of snow throwing on the snow, the central portion of the snow throwing port 10 is blocked by the fall prevention plates 43, 43, and the fall preventing plates 43, 43 immediately descend by normal snow throwing to provide the snow throwing function. In addition, since the snow throwing port 10 is substantially blocked by the snow throwing itself in this snow throwing state, the odor or the like trying to rise from the snow drift groove 3, the snow melting tank or the like is prevented from falling. The snow is blocked by the plates 43, 43 or the snow throwing itself, and thus the odor and the like can be suppressed from being diffused around the snow throwing port 10.

(7) The rear wall 11 of the first recess 20 of the snow throwing mouth 10 faces the rotation locus 23BA of the rear end of the base portion 23B of the plate-like hatch 23, and the lower part from the upper part is the plate-like part. A snow throwing guide including an arcuate guide portion 20AA that is largely separated rearward from a rotation locus 23BA of a base portion 23B of the hatch 23 and a steeply inclined guide portion 20AB, the lower end of which reaches the rear wall 11 of the snow throw opening 11. Since the plate 20A is provided, even if snow or the like is caught between the rear end of the base portion 23B of the plate-shaped hatch 23 and the snow throwing guide plate 20A, the plate-shaped hatch 23 automatically rotates and falls. Further, in cooperation with the snow throwing guide plate 14C on the inside of the front wall 15 of the snow throwing mouth 10, snow throwing and the like is guided further downward.

(8) Around the lower part of the floor plate 23A of the plate-shaped hatch 23, the snow throwing guide plate 20A of the first recess 20 of the snow throwing port 10, the snow throwing guide plate 14C of the front wall 14 of the snow throwing port 10, and the like, Since the heaters 23AB, 20D, 14D and the like having an appropriate shape are provided, it is possible to prevent the occurrence of freezing in the same portion by keeping heat by energizing in cold weather, and further improve the open / close operability of this power open / close type snow throwing hatch.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an embodiment of a power opening / closing type snow throwing hatch according to the present invention.

FIG. 2 is a schematic plan explanatory view of the power opening / closing snow throwing hatch of the present invention.

FIG. 3 is a schematic vertical cross-sectional explanatory view of a main part in a state where the plate-shaped hatch is laid down.

FIG. 4 is a schematic explanatory diagram of a drive circuit using a reversible pump of the torque actuator.

FIG. 5 is a schematic explanatory view of a drive circuit via a direction switching valve of the torque actuator.

FIG. 6 is a schematic explanatory view of an opening / closing drive structure of a plate-like hatch by the reversible motor.

FIG. 7 is a schematic perspective explanatory view of a state in which the plate-shaped hatch is erected and a snow dump truck is used to throw snow on a snow throwing port.

FIG. 8: Guiding a snow-covered dump truck to a traveling zone constructed with a traveling zone constructed of a snow throw bamboo provided with a power opening / closing type snow throwing hatch according to the present invention and a conventional snow throwing mouth provided with an iron lid,
It is a model comparison explanatory view, such as a snow throwing point.

[Explanation of symbols]

1 …… Road surface 1A …… Street shoulder 2 …… Snow throwing area 3 …… Snow drift groove 5A …… First run zone 5B …… Second run zone 5C …… Third run zone 6 …… Snow thrower 7 …… Iron cover 8 …… Dump truck 8A …… Package bed 8B …… Tire 9 …… Car stop 10 …… Snow throw port 10A …… Snow throw port 10 central part 11 …… Snow throw port 10 rear wall 12 …… Snow throw port 10 left side wall 12A ... hatch receiver 13 ... snow throw right side wall 13A ... hatch receiver 14 ... snow throw 10 front wall 14A ... hatch receiver 14C ... snow throw guide plate 14D ... hi -Ta 20 ... First recess 20A ... Snow throwing guide plate 20AA ... Solitary portion of guide plate 20A 20AB ... Inclined portion of guide plate 20A 20D ... Heater 21 ... First horizontal axis 22 ... First bearing 23 ... Plate-shaped hatch 23A ... Floor plate 23AA of plate-shaped hatch 23 ... Rib 23A of floor plate 23A B ... Heater 23B ... Base part of plate-shaped hatch 23 23BA ... Rotation locus of base part 23B 23C ... Left part of plate-shaped hatch 23D ... Right part of plate-shaped hatch 23 23E ... Plate-shaped hatch 23 end 24 ... Pavement layer 25 ... I-beam 27 ... Side fence 27A ... Lower front edge of side fence 27 ... Front fence 29 ... Swing 31 ... Coupling 32 ... Torque Actuator (power drive means) 32A ... Output shaft 32B ... Spline 32C ... Cylindrical piston 32D ... Casing 33 ... Reversible pump 34 ... Hydraulic circuit 35,36 ... Relief valve 37 ... ... Operation switches 38, 39 ... Pit cover 40 ... Second recess 41 ... Second horizontal shaft 43 ... Fall prevention plate 44 ... Balance weight 46 ... Pump 47 ... Hydraulic circuit 4 ...... Starting switch 49 ...... Direction switching valve 50 ...... Operation switch 51 ...... Reversing motor 52 ...... Operation switch 53 ...... Reduction gear 54 ...... Coupling H ...... Thickness of the plate hatch 23 h ...... Top of the snow throwing port 10 and hatch receivers 12B, 13B, 14
B-side spacing

Claims (6)

(57) [Claims] 1. A top of a rear wall 11 of a snow throwing opening 10 having a substantially rectangular shape in plan view provided on an upper part of a snow throwing area 2 such as a snow drift groove 3, a snow melting tank, etc. A first concave portion 20 having an inclined bottom wall portion is provided, and a first horizontal shaft 21 that is rotationally driven in forward and reverse directions by a power driving means such as a torque actuator 32 or an electric motor 51 is provided in the first concave portion 20,
A power opening / closing type snow throwing hatch characterized in that a base portion 23B of a plate-like hatch 23 for opening / closing the snow throwing port 10 is attached to the first horizontal shaft 21. 2. The left and right side portions 23 of the plate-shaped hatch 23
C, 23D is located below the left and right side portions 23C, 23D of the plate hatch 23 in the upright state, and the side walls 12, 13 of the snow throwing port 10, and The power opening / closing type snow throwing hatch according to claim 1, further comprising side fences 27, 27 which occupy positions slightly inside the side walls 12, 13 of the snow throwing mouth 10. 3. The front edge lower parts 27A, 27A of the left and right side fences 27, 27 are connected by a front fence 28, and when the front fence 28 is in an upright state of the plate-like hatch 23, The power opening / closing type snow throwing hatch according to claim 1, wherein the snow opening hatch is arranged so as to be located slightly inside the front wall 14. 4. The rear wall 11 and the front wall 14 of the snow throwing port 10.
Second recesses 40, 40 are formed below the first recess 20 at the central portion in the vertical direction of the second recess 40,
40 is provided with second horizontal shafts 41, 41, and the second horizontal shaft 4
Fall prevention plates 43 and 43 for closing the central portion 10A of the snow throwing port 10 are provided inside the first and the second horizontal shafts 41 and 41, respectively.
Balance weights 44, 44 for keeping the fall prevention plates 43, 43 always horizontal are provided on the outer sides of the fall prevention plates 43, 43, respectively, and the fall prevention plates 43, 43 are applied with a load of a predetermined value or more. The power open / close type snow throwing hatch according to any one of claims 1 to 3, wherein 43 is automatically rotated downward to open a central portion of the snow throwing opening 10. 5. The snow throwing guide plate 14C is provided inside the front wall 14 of the snow throwing mouth 10, and the base portion 23B of the plate-like hatch 23 is provided on the rear wall portion of the first recess 20 of the snow throwing mouth 10. The arcuate portion 20AA facing the turning locus 23BA of the rear end and spaced apart from the turning locus 23BA by a large distance from the upper part to the lower part in sequence, and the lower end reaching the rear wall 11 of the snow throwing port 10. The power opening / closing type snow throwing hatch according to any one of claims 1 to 4, wherein a snow throwing guide plate (20A) including an inclined portion (20AB) is provided. 6. A heat-insulating guide plate 14C on the inside of the front wall 14 of the snow throwing port 10, a snow throwing guide plate 20A of the first recess 20, and a floor plate 23A of the plate-like hatch 23 are used for keeping heat in an appropriate shape. The power opening / closing type snow throwing hatch according to claim 5, wherein heaters 14D, 20D and 23AB are provided.