JP2022174891A - Aerodynamic noise reduction structure of pantograph - Google Patents

Abstract

To provide: an aerodynamic noise reduction structure of pantograph applicable by simple processing to, as well as, attachable highly strongly to an objective member; and a manufacturing method thereof.SOLUTION: Aerodynamic noise reduction structures 20A and 20B for reducing aerodynamic noise generated from a pantograph 3, are each provided with a covering portion 22 covering a top cover 8 of the pantograph 3, with a gap portion 21 formed between with the top cover 8 and the covering portion. The covering portion 22 has a plurality of through-holes 22a allowing a flow flowing into the gap portion 21 to flow out from the gap portion 21. The gap portion 21 is formed along an upper edge portion 8e of the top cover 8. In the gap portion 21, bottom surfaces 21a and 21b of the gap portion 21 are formed to be a flat, curved, or inclined surfaces. The covering portion 22 covers the bottom surfaces 21a and 21b of the gap portion 21 so as to form a predetermined gap between the bottom surfaces 21a and 21b of the gap portion 21.SELECTED DRAWING: Figure 10

Description

The present invention relates to an aerodynamic noise reduction structure for a current collector that reduces aerodynamic noise generated from the current collector.

(Reduction of aerodynamic noise by porous materials)
Reducing aerodynamic noise emitted from each part of the train is an important issue for increasing the speed of the Shinkansen (registered trademark). The pantograph is the main aerodynamic sound source, and among the pantograph members, the hull and boat support are the aerodynamic sound sources that contribute the most. Smoothing the cross-sectional shape and applying through holes are effective in reducing the aerodynamic noise of the hull. As one of the methods for mitigating the flow interference between the boat body and the boat support, we have proposed a method of applying (pasting) a porous material having continuous pores to the surface of the apex cover of the boat support.

A conventional aerodynamic noise reduction structure includes an open-cell porous body that reduces aerodynamic noise on the surface of an object (see, for example, Patent Document 1). Aerodynamic noise reduction effect by attaching a porous material to the surface and its application to a current collector reduces aerodynamic noise by attaching a porous material to the surface of a cylindrical specimen (see, for example, Non-Patent Document 1). In reducing aerodynamic noise by applying porous material to the boat support of pantographs, we have proposed a method of reducing aerodynamic noise by embedding porous material in the minimum necessary area (see, for example, Non-Patent Document 2). .

(Regarding the application and installation method of porous material to the actual vehicle)
In the wind tunnel test, a urethane resin porous material that is easy to process is used, but in the application to the actual vehicle, it is necessary to use a metal porous material and firmly attach it to the target object. There are techniques such as gluing, riveting, or sequential lamination with FRP base materials for attaching metal porous materials. In a conventional installation structure of a cell-structured porous metal material, a porous material is fixed to a non-fixed member by a rivet body penetrating through holes of the porous material and the member to be fixed (see, for example, Patent Document 2). In the conventional mounting structure for cell-structured porous metal materials, an FRP film forming material is applied to the surface of the porous material to form a fixing layer, and this fixing layer and the member to be fixed are fixed with screws ( For example, see Patent Document 3). In the conventional method of providing porous metal on a non-fixed member, a bonding layer resin is infiltrated and cured on the surface of a porous metal molded panel, and an FRP layer is formed on the surface of this bonding layer resin (for example, , see Patent Document 4).

Japanese Patent Application Laid-Open No. 2008-136332

Kenyusha, 2008, vol.22, no.5, p.11-16

Tsuyoshi Hikariyo, 3 others, "Aerodynamic noise reduction by applying porous material to pantograph boat support", The 28th General Symposium on Environmental Engineering, The Japan Society of Mechanical Engineers, July 11-12, 2018 , No.18-10

Japanese Patent Application Laid-Open No. 2009-085406

JP 2009-085407 A

JP 2010-208287 A

The installation structure of the conventional cell-structured porous metal material is to attach the porous metal material to the surface of the pantograph member by adhesion, etc., and it is difficult to apply to a complicated three-dimensional curved surface due to processing restrictions. Also, there is a problem that it cannot be manufactured by a high-strength method such as integral molding.

SUMMARY OF THE INVENTION An object of the present invention is to provide an aerodynamic noise reduction structure for a current collector that can be applied to a member by simple processing and that can be attached with high strength, and a method for manufacturing the same.

The present invention solves the above-described problems by means of solutions as described below.
In addition, although the code|symbol corresponding to embodiment of this invention is attached|subjected and demonstrated, it does not limit to this embodiment.
The invention of claim 1, as shown in FIGS. 8 to 11, 14 to 17 and 20, is an aerodynamic noise reduction structure for a current collector that reduces aerodynamic noise generated from a current collector (3). and a covering portion (22) covering the aerodynamic noise source (8) of the current collector so as to form a gap (21) between the current collector and the aerodynamic noise source (8); An aerodynamic noise reduction structure (20A, 20B) for a current collector, characterized by having a plurality of through-holes (22a) for allowing a flow (F) to flow into a gap and allowing the inflowing flow to flow out from the gap. be.

According to a second aspect of the invention, in the aerodynamic noise reduction structure for a current collector according to the first aspect, as shown in FIGS. The aerodynamic noise reduction structure of the current collector is characterized in that it is formed along the upper edge corner (8e) of the top cover (8) when it is the cover (8).

The invention of claim 3 is the aerodynamic noise reduction structure for a current collector according to claim 1 or claim 2, wherein, as shown in FIGS. , the bottom surface (21a, 21b; 21e) of the gap is formed on a flat surface, a curved surface or an inclined surface, and the covering part forms a predetermined gap with the bottom surface of the gap, The aerodynamic noise reduction structure of the current collector is characterized in that the bottom surface of the gap is covered.

According to a fourth aspect of the invention, in the aerodynamic noise reduction structure for a current collector according to any one of the first to third aspects, as shown in FIG. An aerodynamic noise reduction section (24) for reducing aerodynamic noise is provided, and the covering section covers the aerodynamic noise reduction section so as to form a predetermined gap with the aerodynamic noise reduction section. It is an aerodynamic noise reduction structure of a current collector.

According to the present invention, it can be applied to members by simple processing and can be attached with high strength.

1 is a perspective view schematically showing a part of a current collector having an aerodynamic noise reduction structure for a current collector according to a first embodiment of the present invention; FIG. 1 is a side view schematically showing a current collector provided with an aerodynamic noise reduction structure for a current collector according to a first embodiment of the present invention; FIG. 1 is a plan view schematically showing a current collector provided with an aerodynamic noise reduction structure for a current collector according to a first embodiment of the present invention; FIG. 1 is a front view schematically showing a current collector provided with an aerodynamic noise reduction structure for a current collector according to a first embodiment of the present invention; FIG. 1 is a rear view schematically showing a current collector provided with an aerodynamic noise reduction structure for a current collector according to a first embodiment of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram schematically showing the structure of a current collector provided with an aerodynamic noise reduction structure for a current collector according to a first embodiment of the present invention; 1 is a perspective view schematically showing a vertex cover provided with an aerodynamic noise reduction structure of a current collector according to a first embodiment of the present invention; FIG. FIG. 4 is a plan view schematically showing a portion of the vertex cover provided with the aerodynamic noise reduction structure of the current collector according to the first embodiment of the present invention; FIG. 2 is a side view schematically showing a partly broken apex cover provided with the aerodynamic noise reduction structure of the current collector according to the first embodiment of the present invention; FIG. 9 is a cross-sectional view taken along line XX of FIG. 8; 11 is a cross-sectional view showing an enlarged portion XI of FIG. 10; FIG. FIG. 2 is an exploded view showing a part of the covering portion of the aerodynamic noise reduction structure for the current collector according to the first embodiment of the present invention. FIG. 4A is a photograph for explaining the action of the aerodynamic noise reduction structure of the current collector according to the first embodiment of the present invention, and FIG. , (B) and (C) are contour diagrams of the flow field with the aerodynamic noise reduction structure, and (D) and (E) are contour diagrams of the flow field without the aerodynamic noise reduction structure. FIG. 7 is a vertical cross-sectional view of an aerodynamic noise reduction structure for a current collector according to a second embodiment of the present invention; FIG. 8 is a longitudinal sectional view of an aerodynamic noise reduction structure for a current collector according to a third embodiment of the present invention; FIG. 11 is a vertical cross-sectional view of an aerodynamic noise reduction structure for a current collector according to a fourth embodiment of the present invention; FIG. 11 is a vertical cross-sectional view of an aerodynamic noise reduction structure for a current collector according to a fifth embodiment of the present invention; FIG. 12 is a development view showing a part of the covering portion of the aerodynamic noise reduction structure for the current collector according to the sixth embodiment of the present invention, with the covering portion cut away; FIG. 14 is a development view showing a part of the covering portion of the aerodynamic noise reduction structure for the current collector according to the seventh embodiment of the present invention, with the covering portion cut away; FIG. 12 is a vertical cross-sectional view of an aerodynamic noise reduction structure for a current collector according to an eighth embodiment of the present invention; FIG. 20 is a vertical cross-sectional view of an aerodynamic noise reduction structure for a current collector according to a ninth embodiment of the present invention; FIG. 2 is a schematic diagram schematically showing a wind tunnel test apparatus used for an aerodynamic noise reduction effect test of the aerodynamic noise reduction structure of the current collector according to the example of the present invention; A graph showing the test results of the aerodynamic noise reduction effect test of each specimen A to C when the upper ridge of the aerodynamic noise reduction structure of the current collector according to the embodiment of the present invention is a notch, photographs showing the test situation, and It is a longitudinal cross-sectional view of an upper side corner portion. Graph showing the test results of the aerodynamic noise reduction effect test of each specimen A, D, and E when the upper side edge portion of the aerodynamic noise reduction structure of the current collector according to the embodiment of the present invention is R chamfered, and the test situation. It is the photograph and the longitudinal cross-sectional view of the upper side corner portion shown. A graph showing the test results of the aerodynamic noise reduction effect test of the covering portion of each specimen F to H of the aerodynamic noise reduction structure of the current collector according to the embodiment of the present invention, a photograph showing the test situation, the installation direction of the covering portion, and It is a top view which shows a crease|fold.

(First embodiment)
A first embodiment of the present invention will be described in detail below with reference to the drawings.
An overhead contact line 1 shown in FIGS. 1, 2, and 4 to 6 is an overhead contact line that is installed above a railroad track. The overhead wires 1 are supported at supporting points at predetermined intervals. The trolley wire 1a is an electric wire with which the current collector 3 contacts and moves. The trolley wire 1a supplies a load current to the vehicle 2 as the current collector 3 slides. The vehicle 2 shown in FIGS. 2 and 4 to 6 is an electric vehicle such as an electric train or an electric locomotive. The vehicle 2 is, for example, a railway vehicle such as a bullet train that runs at high speed. The vehicle body 2a is a structure for loading and transporting passengers or cargo.

The current collector 3 shown in FIGS. 1 to 6 is a device for conducting electric power from the trolley wire 1a to the vehicle 2. As shown in FIG. The current collector 3 includes a contact strip 4 shown in FIGS. 1 to 6, a boat body (collector boat) 5, a framework 6, an underframe 17 shown in FIG. 6, and a windshield cover shown in FIGS. 18, an insulator 19 shown in FIGS. 2 and 4 to 6, and aerodynamic noise reduction structures 20A and 20B shown in FIGS. 1 to 5, and the like. The current collector 3 shown in FIGS. 1 to 6 is, as shown in FIGS. 1 and 2, a single-arm pantograph that is asymmetrical with respect to the traveling direction D of the vehicle 2 and can be used in one or both directions. be. As shown in FIGS. 1 and 2, when the current collector 3 is used in the bending direction in which the intermediate hinge 13 is located on the front side of the traveling direction of the vehicle 2, the aerodynamic noise is relatively small, and the aerodynamic noise is relatively small. The aerodynamic noise becomes relatively loud when used in the anti-bending direction in which the intermediate hinge 13 is located at . The current collector 3 shown in FIGS. 1 to 6 is moving in the bending direction in which the intermediate hinge 13 is positioned on the front side of the traveling direction of the vehicle 2 .

The contact strip 4 shown in FIGS. 1 to 6 is a member that slides on the trolley wire 1a. As shown in FIGS. 1 and 3 to 5, the contact strip 4 is a plate-like member made of metal or carbon and extending in a direction perpendicular to the traveling direction D of the vehicle 2 (in the sleeper direction). The contact strips 4 are separate parts manufactured separately from the boat body 5, and are attached to the upper part of the boat body 5 in a state in which a plurality of them are arranged in the longitudinal direction (sleep direction) of the boat body 5. . The contact strip 4 is supported by an elastic body such as a spring so as to be relatively displaceable with respect to the boat body 5 .

A boat body 5 shown in FIGS. 1 to 6 is a member that supports the contact strip 4 . The boat body 5 is generally an elongated metal columnar member extending in a direction perpendicular to the trolley wire 1a (in the sleeper direction). For example, as shown in FIG. 2, the boat body 5 is symmetrical with respect to the central axis of the boat body 5, and both the front and rear sides are formed in the same shape. The boat body 5 has a cross-sectional shape of a streamline shape or a curved surface approximating a streamline shape in order to prevent separation of the flow (airflow) F as much as possible, and is composed of a smooth curve. For the hull 5, for example, the cross-sectional shape of the hull is smoothed so that aerodynamic noise reduction and lift characteristic stabilization can both be achieved by a method that combines Computational Fluid Dynamics (CFD) analysis and optimization methods. It is a smoothed boat body (smooth shaped boat body). The hull 5 shown in FIGS. 1 to 6 is, for example, a pantograph hull for bullet trains (for high speed) with improved follow-up performance to the trolley wire 1a. As shown in FIGS. 1 to 5, the boat body 5 includes a horn 5a and the like.

When the vehicle 2 passes through the turnout, the horn 5a prevents interruption of the trolley wire 1a in a direction different from the traveling direction of the vehicle 2 among the two trolley wires 1a intersecting above the turnout. It is a member for The horn 5a is a metal member that protrudes from both ends in the longitudinal direction of the boat body 5 and has a downwardly curved tip as shown in FIGS. .

A framework 6 shown in FIGS. 1 to 6 is a member that supports the boat body 5 . The frame 6 has a link mechanism capable of moving vertically while supporting the boat body 5 . The framework 6 includes a boat support portion 7 shown in FIGS. 1 and 4 to 10, a top cover 8 shown in FIGS. 1 to 10, an upper frame 9, and a boat support link (balance bar) 10 shown in FIG. , a lower frame 11 shown in FIGS. 1, 2 and 4 to 6, a balance bar 12 shown in FIG. 6, and an intermediate hinge (bending portion) 13 shown in FIGS. The framework 6 is raised by the biasing force of the main spring 16 shown in FIG. 6 when in use, and is lowered by the driving force generated by the cylinder device against the biasing force of the main spring 16 when not in use (when folded). .

The boat support portion 7 shown in FIGS. 1 and 4 to 10 is a portion that supports the boat body 5 . The boat support portion 7 pushes up the boat body 5 horizontally with respect to the overhead wire 1, and gives the boat body 5 a cushioning action by a spring. The boat support portion 7 maintains the balance of the boat body 5 and improves followability to the trolley wire 1a. The boat support 7 is supported on the top of the upper frame 9, as shown in FIGS.

A vertex cover 8 shown in FIGS. 1 to 10 is a member that covers the boat support portion 7 . As shown in FIG. 6, the vertex cover 8 covers the upper end portion of the upper frame 9 so as to cover the hinge portion (vertical hinge portion) that rotatably connects the upper frame 9 and the boat support link 10 to the boat support portion 7. It is detachably attached to (the top part), and is shaped so as not to obstruct the flow F as shown in FIGS. The apex cover 8 prevents the flow F from entering the boat support 7 to generate a large aerodynamic noise and prevents an increase in air resistance. The apex cover 8 is, for example, a covering member made of metal or Fiber Reinforced Plastics (FRP) having incombustibility or flame retardancy. The vertex cover 8 is a member having a substantially U-shaped planar shape as shown in FIG. 8 and a substantially U-shaped vertical cross-sectional shape as shown in FIG. The vertex cover 8 includes an upper surface portion 8a shown in FIGS. 7 to 9, a lower surface portion 8b shown in FIGS. 7, 9 and 10, a side surface portion 8c shown in FIGS. 8, the upper corner (upper edge) 8e shown in FIGS. 7 to 9, the lower corner (lower edge) 8f shown in FIGS. 7, 9 and 10, It has a mounting portion 8g shown in FIGS. 8 to 11, a through hole 8h shown in FIG. 10, and the like. As shown in FIG. 7, the vertex cover 8 is a polyhedron composed of an upper surface portion 8a, a lower surface portion 8b, a side surface portion 8c and a rear surface portion 8d. intersect at an upper edge portion 8e and a lower edge portion 8f.

The upper surface portion 8a shown in FIGS. 7 to 9 constitutes the upper surface of the vertex cover 8. As shown in FIGS. As shown in FIGS. 7 and 9, the upper surface portion 8a is formed into a flat inclined surface so as to be approximately the same height (flush) with the upper surface of the upper frame 9. As shown in FIG. A lower surface portion 8b shown in FIGS. As shown in FIG. 10, the lower surface portion 8b has a front side that is approximately the same height (flush) with the lower surface of the upper frame 9, and a rear side that is lower than the lower surface of the upper frame 9 (protrudes downward). As shown, it is formed into a flat inclined surface that is inclined at a plurality of angles from the front side toward the rear side.

A side surface portion 8c shown in FIGS. As shown in FIGS. 7, 8 and 10, the side portions 8c are detachably attached to both side surfaces of the upper end portion of the upper frame 9 so as to sandwich both side surfaces of the upper end portion of the upper frame 9. FIG. As shown in FIGS. 7 and 9, the side surface portion 8c is a flat plate-like portion having rounded front and rear sides. A back surface portion 8d shown in FIGS. As shown in FIGS. 7 and 8, the rear surface portion 8d has a substantially spherical appearance, and the upper surface portion 8a, the lower surface portion 8b, and the side surface portion 8c are connected to the rear sides thereof. It is formed at the same height (flush) as the lower surface portion 8b and the side surface portion 8c.

An upper edge portion 8e shown in FIGS. 7 to 9 is a portion where the upper surface portion 8a and the side surface portion 8c intersect. As shown in FIG. 7, the upper edge portion 8e is formed linearly along the lengthwise direction of the upper surface portion 8a and the side surface portion 8c, and has an angular cross section as shown in FIG. . A lower edge portion 8f shown in FIGS. 7, 9 and 10 is a portion where the lower surface portion 8b and the side surface portion 8c intersect. As shown in FIG. 7, the lower edge portion 8f is formed in a curved shape and a straight shape along the length direction of the lower surface portion 8b and the side surface portion 8c, and as shown in FIG. formed.

A mounting portion 8g shown in FIGS. 8 to 11 is a portion to which the covering portion 22 is mounted. As shown in FIGS. 10 and 11, the mounting portion 8g is a recess formed in the upper surface portion 8a and the side surface portion 8c. is formed to have a predetermined length, width and depth so that the top surface portion 8a and the side surface portion 8c have the same height (flush). As shown in FIGS. 8 and 9, the mounting portion 8g has a quadrangular planar shape and side surface shape so that the covering portion 22 can be detachably fitted thereto. A through hole 8h shown in FIG. The through hole 8h is formed so as to pass through the side surface portion 8c of the vertex cover 8. As shown in FIG.

The upper frame 9 shown in FIGS. 1 to 10 is a member that is rotatably connected to the boat support 7. As shown in FIG. The upper frame 9 is a cylindrical member forming the upper half of the frame 6, and accommodates the boat support link 10 shown in FIG. 6 inside. One end of the upper frame 9 is rotatably connected to the boat support portion 7 , and the other end of the upper frame 9 is rotatably connected to the lower frame 11 . The boat support link 10 is a member that maintains the boat body 5 and the boat support portion 7 in a predetermined posture. One end of the boat support link 10 is rotatably connected to the boat support portion 7 and the other end of the boat support link 10 is rotatably connected to the lower frame 11 .

The lower frame 11 shown in FIGS. 1, 2 and 4 to 6 is a member rotatably connected to the underframe 17. As shown in FIG. The lower frame 11 is a cylindrical member forming the lower half of the frame 6, and accommodates the balance rod 12 shown in FIG. 6 inside. One end of the lower frame 11 is rotatably connected to the upper frame 9 , and the other end of the lower frame 11 is connected to the main shaft 14 . The balance rod 12 is a member for adjusting the trajectory of the vertical displacement of the boat body 5 . One end of the balance rod 12 is rotatably connected to the upper frame 9 and the other end of the balance rod 12 is rotatably connected to the main shaft 14 . An intermediate hinge 13 shown in FIGS. 1 to 6 is a portion that rotatably connects the upper frame 9 and the lower frame 11 . The intermediate hinge 13 functions as a joint that connects the upper frame 9 and the lower frame 11, as shown in FIG.

A main shaft 14 shown in FIG. 6 is a member that moves the frame 6 up and down. The main shaft 14 operates in conjunction with the framework 6, and rotates in forward and reverse directions to move the framework 6 up and down. The main shaft 14 is rotatably supported by the underframe 17 and rotates integrally with the lower end of the lower frame 11 . The lever portion 15 is a portion that converts linear motion into rotary motion. The lever portion 15 rotates integrally with the main shaft 14 with the main shaft 14 as a fulcrum. The main spring 16 is a member that applies a lifting force to the framework 6 . The main spring 16 is a push-up spring that biases the main shaft 14 so that the main shaft 14 rotates and the framework 6 rises. The other end of the main spring 16 is rotatably connected to the lever portion 15 .

The underframe 17 shown in FIG. 6 is a member that supports the framework 6 . The underframe 17 is installed on the roof of the vehicle body 2a via insulators 18 while supporting the base of the frame 6 . The underframe 17 supports an elevating mechanism including a main shaft 14, a lever portion 15, a main spring 16, and the like, for elevating the frame 6. As shown in FIG.

A windshield cover 18 shown in FIGS. 2 to 6 is a member that covers the underframe 17 . The windshield cover 18 covers the main shaft 14, the lever portion 15, the main spring 16, the underframe 17, etc., as shown in FIG. is formed in The windshield cover 18 prevents the flow F from entering the underframe 17 to generate a large aerodynamic noise, and also prevents an increase in air resistance. The windshield cover 18 is, for example, a covering member made of FRP.

The insulator 19 shown in FIGS. 2 and 4 to 6 is a member that electrically insulates between the vehicle body 2a and the underframe 17. As shown in FIG. The insulator 19 is, for example, a low-noise insulator formed into a shape that is effective in suppressing generation of aerodynamic noise. The insulator 19 has a substantially elliptical cross-section when cut along a horizontal plane in order to suppress the shedding of vortices generated at the trailing edge of the insulator 19 . The insulators 19 support the bottom surface of the underframe 17 near both edges.

The aerodynamic noise reduction structures 20A and 20B shown in FIGS. 1 to 5 and 7 to 11 are structures for reducing aerodynamic noise generated from the current collector 3. FIG. The aerodynamic noise reduction structures 20</b>A and 20</b>B reduce aerodynamic noise generated from the aerodynamic noise source of the current collector 3 . Here, the aerodynamic sound generating source is the upper edge portion 8e where the adjacent upper surface portion 8a and side surface portion 8c of the vertex cover 8 intersect. As shown in FIGS. 8 and 10, the aerodynamic noise reduction structures 20A and 20B are symmetrical structures about the centerline of the vertex cover 8 when attached to the vertex cover 8. FIG. Both of the aerodynamic noise reduction structures 20A and 20B have the same structure, and hereinafter, one aerodynamic noise reduction structure 20A will be described, and detailed description of the other aerodynamic noise reduction structure 20B will be omitted. The aerodynamic noise reduction structures 20A and 20B include gap portions 21 shown in FIGS. 8 to 11, covering portions 22 shown in FIGS. 7 to 12, fixing portions 23 shown in FIGS. 7 to 10, and the like.

A gap portion 21 shown in FIGS. 8 to 11 is a gap formed between the vertex cover 8 and the covering portion 22 . As shown in FIGS. 8 and 9, the gap 21 is formed along the upper edge 8e of the vertex cover 8, and as shown in FIGS. It is formed on a plane. As shown in FIGS. 10 and 11, the gap 21 is a recess having a substantially L-shaped vertical cross section, and as shown in FIGS. is. The gap 21 is formed, for example, by machining such as cutting, and as shown in FIGS. Department. The gap 21 is a space through which the flow F passes in any direction. It functions as one ventilation chamber continuously extending in the vertical direction. The gap portion 21 includes bottom surfaces 21a and 21b shown in FIGS. 8 to 11, end surfaces 21c and 21d shown in FIGS. 8 and 9, and the like.

Bottom surfaces 21a and 21b shown in FIGS. 8 to 11 are portions formed on the surface of the vertex cover 8 and forming the bottom of the gap 21. As shown in FIGS. As shown in FIG. 9, the bottom surface 21a is a flat surface formed parallel to the upper surface portion 8a. As shown in FIG. 8, the bottom surface 21b is a flat surface formed parallel to the side surface portion 8c. The bottom surfaces 21a and 21b are perpendicular to each other as shown in FIGS. 10 and 11, and perpendicular to the end surfaces 21c and 21d as shown in FIGS. The end surfaces 21 c and 21 d are portions formed on the surface of the vertex cover 8 and forming end portions of the gap portion 21 . The end face 21c is formed near the end opposite to the back face 8d, and the end face 21d is formed near the back face 8d. The end faces 21c and 21d are planes formed in parallel and facing each other.

A covering portion 22 shown in FIGS. 7 to 11 is a portion covering the vertex cover 8 so as to form a gap portion 21 with the vertex cover 8 . As shown in FIGS. 7, 10 and 11, the covering portion 22 is formed in a shape along the surface of the vertex cover 8, and closes the opening of the gap portion 21 as shown in FIGS. It is attached to the surface of the vertex cover 8 as shown in FIG. Covering portion 22 covers bottom surfaces 21 a and 21 b of gap portion 21 so as to form a predetermined gap with bottom surfaces 21 a and 21 b. The covering portion 22 is, for example, a thin plate member having a plate thickness of about 0.5 mm, and is adhered to the mounting portion 8g of the top cover 8 with an adhesive or the like. The covering portion 22 is, for example, a perforated plate (perforated plate) such as aluminum alloy or stainless steel punching metal. The covering portion 22 constitutes a part of the vertex cover 8 when mounted on the mounting portion 8g of the vertex cover 8. They constitute parts of the upper surface portion 8a, the side surface portion 8c, and the upper edge portion 8e.

As shown in FIG. 7, the covering portion 22 is formed to have a flat surface so that the upper surface of the covering portion 22 is at the same height (flush) with the upper surface portion 8a of the vertex cover 8, as shown in FIG. As shown, the upper surface of the covering portion 22 near the rear surface portion 8d of the vertex cover 8 is formed into a flat inclined surface. As shown in FIGS. 10 and 11, the covering portion 22 is formed to have a flat surface so that the side surface of the covering portion 22 is at the same height (flush) with the side surface portion 8c of the vertex cover 8. . As shown in FIG. 10, the cover portion 22 is attached to the attachment portion 8g so as to sandwich the side surface portion 8c of the vertex cover 8, and is formed by bending so that the cross section has a substantially inverted U-shape. The covering portion 22 has a through hole 22a shown in FIGS. 8 to 12, a bone (bar) 22b shown in FIGS. 10 to 12, a through hole 22c shown in FIG. As shown in FIG. 7, the covering portion 22 is bent along the upper ridge _8e , and as shown in FIG. there is As shown in FIG. 12, the covering portion 22 has a plurality of through-holes 22a arranged such that the center line L ₀ of the plurality of through-holes 22a is aligned with the direction of the flow F. It is folded on the folding line L _B parallel to the center line L ₀ of 22a. Here, the center line L ₀ is a straight line connecting the center lines of the adjacent through holes 22a.

The covering portion 22 can also be manufactured by a modeling device other than machining. Here, the modeling device is a device that manufactures an object of arbitrary shape. The modeling apparatus, for example, uses 3DCAD (3 Dimensional Computer Aided Design) to design a three-dimensional shape in a virtual three-dimensional space by computer, or 3DCG (3DCG) to create a three-dimensional shape in a virtual three-dimensional space by a computer. 3D printers that manufacture objects based on 3D digital models composed of 3D data generated by 3D computer graphics.

When the covering portion 22 is manufactured by a resin 3D printer, for example, a stereolithography method in which a liquid resin is irradiated with ultraviolet light or the like to harden it little by little to manufacture an object, or an object is manufactured by gradually piling up heat-melted resin. Fused Deposition Modeling (FDM) method for manufacturing, sheet lamination in which a sheet material is cut into the cross-sectional shape of an object, each layer is laminated while bonding and welding, and an object is manufactured by irradiating ultraviolet rays or heating to harden. method, powder bonding method in which adhesive is sprayed on powdered resin to manufacture an object, and material injection method in which a liquid photocurable resin or wax is sprayed from a nozzle and irradiated with ultraviolet rays or heated to harden to manufacture an object. Part 22 is manufactured.

When the covering portion 22 is manufactured by a metal 3D printer, for example, a laser sintering method (Selective laser sintering (SLS) method) in which metal powder is irradiated with a laser beam to sinter the metal powder to manufacture an object, Direct metal laser sintering (DMLS) method, in which an object is manufactured by sintering metal powder by irradiating metal powder with ytterbium laser light instead of carbon dioxide laser in laser sintering method, metal powder Selective laser melting (SLM) method, in which an object is manufactured by irradiating a laser beam to melt the metal powder, and an electron beam is irradiated to the metal powder to melt the metal powder to manufacture an object Electron Beam Melting (EBM) method, Molten metal lamination method in which a metal wire is irradiated with an electron beam instead of the metal powder of the electron beam melting method to melt the metal wire to manufacture an object, Metal powder is ejected from the nozzle Coating 22 is fabricated, such as by a laser engineered net shaping (LENS) process, in which the material is dropped into a molten pool and sintered with laser light to produce an object.

The through hole 22a shown in FIGS. 8 to 12 is a portion that allows the flow F to flow into the gap 21 and allows the inflowing flow F to flow out from the gap 21. As shown in FIG. As shown in FIG. 12, the through holes 22a are a plurality of round holes formed in a circle at predetermined intervals (hole pitch), and holes are present at the vertices of an equilateral triangle in the hole array (pattern). It is a 60° staggered arrangement. A large number of through-holes 22a are arranged so that the center line L ₀ of these through-holes 22a is aligned with the direction of the flow F. The through hole 22a is formed with an opening ratio of about 0.33 or more, for example, so as not to significantly impair the aerodynamic noise reduction effect. A bone 22b shown in FIGS. 10 to 12 is a portion between adjacent through holes 22a. The bone 22b is the space between the rim of the through hole 22a and the rim of the through hole 22a. A through-hole 22c shown in FIG. The through hole 22c is formed at a position corresponding to the through hole 8h of the vertex cover 8 when the covering portion 22 is attached to the vertex cover 8. As shown in FIG.

A fixing portion 23 shown in FIGS. 7 to 10 is a member for fixing the covering portion 22 . The fixed portion 23 is a fastening member such as a bolt having a male thread portion that meshes with a female thread portion formed on the side surface of the boat support portion 7, as shown in FIG. The fixing portion 23 is inserted into the through hole 8h of the vertex cover 8 and the through hole 22c of the covering portion 22 to fix the covering portion 22 to the boat support portion 7 in a detachable manner. The fixing portion 23 fastens (co-fastens) the covering portion 22 together with the top cover 8 to the boat support portion 7 so that the top cover 8 is sandwiched between the covering portion 22 and the boat support portion 7 .

Next, the operation of the aerodynamic noise reduction structure for the current collector according to the first embodiment of the present invention will be described.
FIG. 13 is a photograph showing changes in the flow field when a porous material is applied to the cylindrical surface and when a porous material is not applied. The aerodynamic noise reduction structure shown in FIG. 13A is a porous material that imitates the aerodynamic noise reduction structures 20A and 20B shown in FIGS. 1 to 5 and 7 to 11. FIG. The porous material has a three-dimensional skeletal network structure such as continuous pores in which micropores are formed on the walls of the pores and the pores communicate with each other. The porous material is a rigid porous material, such as a flame retardant or non-combustible metallic porous material. FIGS. 13B and 13C are flow field measurement results when a porous material is applied, and FIGS. 13D and 13E are flow field measurement results when a porous material is not applied. is. Here, FIGS. 13(B) and 13(D) are measurement results by wind tunnel tests, and FIGS. 13(C) and 13(E) are analysis results by Computational Fluid Dynamics (CFD) analysis.

When the surface of the cylinder in the flow field shown in FIG. 13(A) is not provided with the aerodynamic noise reduction structure, as shown in FIGS. At the separation point on the surface, the flow F in the direction of the arrow separates, and the air alternately wraps around the downstream side of this cylinder. Therefore, Karman vortices are generated by interaction of vortices generated from the separation shear layer on the surface of the cylinder, and noise and vibration are generated due to the Karman vortices. On the other hand, when the surface of the cylinder in the flow field shown in FIG. A flow F in the aerodynamic noise reduction structure naturally flows out from a low pressure area such as the vicinity of the separation point. As a result, the flow field is stabilized, vortex shedding is weakened, and aerodynamic noise is reduced.

When the vehicle 2 travels in the direction of travel D shown in FIGS. occurs. A flow F flows in from a through hole 22a in a high pressure section such as a stagnation point on the surface of the vertex cover 8 shown in FIGS. When the flow F flows in from the through hole 22a of the high pressure section, the flow F passes through the gap 21 shown in FIGS. F naturally flows out. As a result, the flow field is stabilized, vortex shedding is weakened, and aerodynamic noise is reduced.

The aerodynamic noise reduction structure of the current collector according to the first embodiment of the present invention has the following effects.
(1) In the first embodiment, the cover 22 covers the top cover 8 so as to form a gap 21 between the current collector 3 and the top cover 8, and the flow F flows into the gap 21. , the covering portion 22 has a plurality of through holes 22a for allowing the inflowing flow F to flow out from the gap portion 21. As shown in FIG. Therefore, by providing the through holes 22a that allow the flow F to flow naturally into and out of the surface of the member and having the gaps 21 that allow the flow F to advect therewithin, the aerodynamic noise can be reduced. . Moreover, it can be implemented only by covering the gap 21 with the covering portion 22 having the through holes 22a, and can be implemented more easily than the conventional porous material. For example, the covering portion 22 such as a perforated plate can be firmly fastened to the vertex cover 8 by fastening together. As a result, there is no need to consider the risk of peeling off as with conventional porous materials, and it is more reliable and easier to apply than conventional porous material adhesion. Furthermore, the aerodynamic noise generated from the aerodynamic noise source can be reduced by an aerodynamic noise reduction structure that is easy to apply and manufacture, such as covering the gap 21 with a perforated plate, for example.

(2) In the first embodiment, the gap portion 21 is formed along the upper edge portion 8e of the vertex cover 8. As shown in FIG. Therefore, when the upper corner portion 8e has a simple shape, the covering portion 22 can be easily manufactured by bending or pressing the perforated plate. Also, if the upper corner portion 8e has a complicated shape, the coating portion 22 can be easily manufactured by manufacturing a perforated plate using processing technology such as a high-strength metal 3D printer. As a result, it can be applied to three-dimensional curved surfaces such as conventional porous materials that are difficult to bond or attach.

(3) In the first embodiment, the bottom surfaces 21a and 21b of the gap portion 21 are formed flat, and the gap portion 21 is formed so as to form a predetermined gap with the bottom surfaces 21a and 21b of the gap portion 21. The covering portion 22 covers the bottom surfaces 21a and 21b of the . Therefore, for example, the recessed gap 21 can be easily formed by machining or the like by notching the upper edge 8e of the vertex cover 8, and the aerodynamic noise reduction effect can be easily obtained.

(Second embodiment)
1 to 12 are denoted by the same reference numerals, and detailed description thereof will be omitted.
The gap 21 shown in FIG. 14 has a curved bottom surface 21e. The gap portion 21 has a vertical cross-sectional shape of a 1/4 circle formed in an arc (R shape) with a predetermined radius, and is chamfered (R chamfer) so as to round off the corners of the upper edge portion 8e. is. This second embodiment has the same effect as the first embodiment.

(Third embodiment)
The gap 21 shown in FIG. 15 has a bottom surface 21e of a quarter circle, like the gap 21 shown in FIG. Unlike the covering portion 22 shown in FIGS. 11 and 14, the covering portion 22 is formed in a curved surface along the bottom surface 21e of the gap portion 21 as shown in FIG. R-shaped). The covering portion 22 covers the bottom surface 21e so as to form a certain gap with the bottom surface 21e. This third embodiment has the same effects as those of the first and second embodiments.

(Fourth embodiment)
The gap 21 shown in FIG. 16 is a concave portion having bottom surfaces 21a and 21b shallower than the gap 21 shown in FIG. 11 and having an inverted L-shaped vertical cross section. Covering portion 22 covers bottom surfaces 21a and 21b along bottom surfaces 21a and 21b of gap portion 21 so as to form a constant gap with bottom surfaces 21a and 21b. This fourth embodiment has the same effects as those of the first to third embodiments.

(Fifth embodiment)
The gap portion 21 shown in FIG. 17 has an inclined bottom surface 21e. The gap portion 21 is a flat surface having a vertical cross-sectional shape formed at a predetermined inclination angle, and is chamfered (C chamfer) so as to form a slope on the corner of the upper edge portion 8e. Covering portion 22 covers bottom surface 21e along bottom surface 21e of gap portion 21 so as to form a constant gap with bottom surface 21e. This fifth embodiment has the same effects as those of the first to fourth embodiments.

(Sixth embodiment)
In the covering portion 22 shown in FIG. 18, the plurality of through-holes 22a are arranged such that the center line L ₀ of the plurality of through-holes 22a is orthogonal to the direction of the flow F. It is folded on the folding line L _B perpendicular to the line L ₀ . The covering portion 22 is bent along the upper edge portion 8e, and is bent along a folding line L _B that is perpendicular to the center line L ₀ and passes through the center point of the through hole 22a. Like the through holes 22a shown in FIG. 11, the through holes 22a are arranged in a 60° zigzag arrangement, but unlike the arrangement (orientation) of the through holes 22a shown in FIG. , the arrangement (orientation) of the through holes 22a is rotated by 90°. A large number of through-holes 22a are arranged so that the center line L ₀ of these through-holes 22a is perpendicular to the direction of the flow F. This sixth embodiment has the same effects as those of the first to fifth embodiments.

(Seventh embodiment)
The covering portion 22 shown in FIG. 19 is bent along the upper edge portion _8e , but unlike the covering portion 22 shown in FIG. It is bent at line _LB. The covering portion 22 has a plurality of through holes 22a arranged so that the center lines L ₀ of the plurality of through holes 22a match the direction of the flow F, and the center lines L ₀ of the plurality of through holes 22a are aligned. is folded at The through-holes 22a are arranged in a 60° zigzag arrangement, similar to the through-holes 22a shown in FIG. This seventh embodiment has the same effects as those of the first to sixth embodiments.

(Eighth embodiment)
An aerodynamic noise reduction structure 20A shown in FIG. 20 includes a gap portion 21, an aerodynamic noise reduction portion 24, and the like. The gap portion 21 is a gap formed between the covering portion 22 and the aerodynamic noise reduction portion 24 . The gap portion 21 is formed along the upper edge portion 8e of the vertex cover 8, and is a concave portion having a substantially L-shaped vertical cross section. be. The bottom surfaces 21 a and 21 b are portions that are formed on the surface of the aerodynamic noise reduction portion 24 and constitute the bottom portion of the gap portion 21 . The covering portion 22 covers the aerodynamic noise reduction portion 24 so as to form a predetermined gap with the aerodynamic noise reduction portion 24 .

The aerodynamic noise reduction section 24 is means for reducing aerodynamic noise while being housed in the gap section 21 . The aerodynamic noise reduction section 24 covers the surface of the vertex cover 8 to reduce aerodynamic noise. The aerodynamic noise reduction portion 24 is attached to the upper edge portion 8e of the vertex cover 8 with an adhesive or the like. The aerodynamic noise reduction portion 24 has a three-dimensional skeletal network structure such as a porous material of continuous pores in which micropores are formed in the walls of the pores and the pores communicate with each other. The aerodynamic noise reduction portion 24 is, for example, a hard porous material such as a flame-retardant or non-combustible metal porous material. The aerodynamic noise reduction section 24 allows the flow F to flow into the interior of the aerodynamic noise reduction section 24 from a high pressure section such as a stagnation point through the through hole 22a. The aerodynamic noise reduction section 24 stabilizes the flow field by allowing the flow F in the aerodynamic noise reduction section 24 to naturally flow out from a low pressure section such as the vicinity of the separation point through the through hole 22a, thereby weakening the aerodynamic noise. reduce

The aerodynamic noise reduction unit 24 is generally selected to have a small cell for the purpose of sound absorption. something is selected. In the aerodynamic noise reduction part 24, if the cell range representing the number of pores on a straight line with a length of 25 mm (1 inch) is less than 6 and exceeds 55, the noise level cannot be expected to decrease. Those with a cell range of 11 or more and 16 or less are particularly preferred. Even if the cell range is appropriate, the aerodynamic noise reduction unit 24 has a porosity (pore volume), which is the ratio between the volume of a solid material (bulk material) having the same shape as the porous material and the volume of the air portion of the porous material. If the porosity or porosity) is low, a reduction in noise level cannot be expected, so those having a porosity as high as 80% or more are preferred.

The aerodynamic noise reduction structure of the current collector according to the eighth embodiment has the following effects in addition to the effects of the first to seventh embodiments.
In the eighth embodiment, the aerodynamic noise reduction section 24 reduces aerodynamic noise while being housed in the gap portion 21, and the aerodynamic noise reduction section 24 is configured to form a predetermined gap with the aerodynamic noise reduction section 24. 24 is covered with the covering portion 22 . Therefore, the flow F can flow into the aerodynamic noise reduction section 24 from a high pressure section such as a stagnation point through the through hole 22a. As a result, the flow F in the aerodynamic noise reduction section 24 is allowed to naturally flow out from the low pressure section such as the vicinity of the separation point through the through hole 22a, thereby stabilizing the flow field by the aerodynamic noise reduction section 24 and weakening the release of the vortex, thereby weakening the aerodynamic noise. can be reduced.

(Ninth embodiment)
Unlike the aerodynamic noise reduction section 24 shown in FIG. 20, the aerodynamic noise reduction section 24 shown in FIG. The aerodynamic noise reduction unit 24 includes, for example, inorganic fibers such as glass wool, glass fiber or rock wool, metal fibers such as aluminum fiber, stainless steel fiber or iron alloy fiber, plastic foam, urethane, ethylene propylene rubber (EPDM), The sound absorbing material is an organic foam system such as chloroprene, polyurethane foam, foamed polystyrene, or natural polymer porous material, a porous sound absorbing material such as ceramics, or a sound absorbing material made of any combination thereof. In the ninth embodiment, in addition to the effects of the first to seventh embodiments, the aerodynamic noise that passes through the gap 21 from the through hole 22a of the cover 22 can be reduced by the aerodynamic noise reduction section 24. , the aerodynamic noise generated from the vertex cover can be further reduced.

Next, an embodiment of the invention will be described.
(wind tunnel test)
The specimens A to H were attached to the apex cover of an actual Shinkansen pantograph equipped with a smoothed hull, and the aerodynamic noise was evaluated by a wind tunnel test. The wind tunnel test used an open-body wind tunnel test equipment of the Railway Technical Research Institute. As shown in Fig. 22, while the actual Shinkansen pantograph was supported on the first model support carriage of the wind tunnel measurement section of the wind tunnel test equipment, air was blown into the pantograph for Shinkansen in the wind tunnel measurement section from a blowing nozzle at a wind speed of 360 km/h. We measured the aerodynamic sound generated from the Shinkansen pantograph by this air flow with an aerodynamic sound measurement microphone.

(Specimen A to C)
As shown in FIG. 23, the wind tunnel test shown in FIG. 22 confirmed the effect of reducing the aerodynamic noise when the conditions of the upper corner were changed in various ways using the apex cover provided with a notch in the upper corner. Specimens A to C are top covers of current Shinkansen pantographs. In the specimen A, a plate having no through holes 22a is attached to the vertex cover 8 so as to block the gap 21 of the upper edge portion 8e of the vertex cover 8 shown in FIGS. The test piece B does not block the gap 21 of the upper edge 8e of the vertex cover 8 shown in FIGS. 10 and 11, but opens it. Specimen C is the first embodiment shown in FIGS. there is Specimen C used a perforated plate with a thickness of 0.5 mm in which holes with an inner diameter of 3 mm were arranged in a 60° zigzag pattern at a pitch of 4 mm. be.

(Specimen D, E)
As shown in FIG. 24, the wind tunnel test shown in FIG. confirmed. Specimens D and E are apex covers of current Shinkansen pantographs. The test piece D does not close the gap 21 of the upper corner 8e of the vertex cover 8 shown in FIG. 14 but opens it. The test piece E is the second embodiment shown in FIG. 14, and a covering portion 22 of a perforated plate is attached to the vertex cover 8 so as to close the gap 21 of the upper edge portion 8e of the vertex cover 8 . The specimen E uses a perforated plate similar to that of the specimen C, and as shown in FIG.

(Specimen F to H)
Fig. 22 shows the aerodynamic noise reduction effect when changing the installation direction and crease of the perforated plate as shown in Fig. 25 using the apex cover provided with an arc-shaped R chamfer on the upper edge shown in Fig. 24 . It was confirmed in the wind tunnel test shown. Specimens FH used the same perforated plates as Specimens C and E. The specimen F is the second embodiment shown in FIG. 14, in which the orientation of the perforated plate is longitudinal and the folds of the perforated plate are strained. In the specimen G, the orientation of the perforated plate is horizontal, and the folds of the perforated plate are perforated. In the specimen H, the orientation of the perforated plate is longitudinal, and the folds of the perforated plate are perforated folds.

(Evaluation result of aerodynamic noise reduction effect)
FIG. 23 shows the measurement results of the aerodynamic noise of the specimens A to C in the wind tunnel test. The vertical axis shown in FIG. 23 is the noise level OA value (dB(A)). Specimen B had an OA value substantially equal to that of Specimen A, and it was confirmed that no aerodynamic noise reduction effect was observed. As a result, it was confirmed that the aerodynamic noise reduction effect was not recognized when the notch of the upper side corner was not closed, similarly to the case of closing the notch of the upper side corner. On the other hand, it was confirmed that the OA value of the specimen C could be reduced by about 0.6 dB compared to that of the specimen A, and that the aerodynamic noise reduction effect was higher than that of the specimens A and B. As a result, when the notch in the upper corner is covered with a perforated plate, the aerodynamic noise reduction effect is greater than when the notch in the upper corner is closed or when the notch in the upper corner is not closed. confirmed to be obtained.

FIG. 24 shows the measurement results of the aerodynamic noise of the specimens D and E in the wind tunnel test. The vertical axis shown in FIG. 24 is the noise level OA value (dB(A)). It was confirmed that the specimen D can reduce the OA value by about 0.4 dB compared to the specimen A. As a result, it was confirmed that when the R-chamfering of the upper ridge is not blocked, the aerodynamic noise reduction effect is recognized as compared to the case where the upper ridge is not chamfered. Specimen E was able to reduce the OA value by about 0.8 dB compared to Specimen A, and it was confirmed that Specimens A and D had a higher aerodynamic noise reduction effect. As a result, when the R-chamfering of the upper corner is covered with the perforated plate, the aerodynamic noise reduction effect can be obtained compared to the case where the upper corner is not R-chamfered or the case where the upper corner is R-chamfered. was confirmed.

FIG. 25 shows the measurement results of the aerodynamic noise of the specimens F to H in the wind tunnel test. The vertical axis shown in FIG. 25 is the noise level OA value (dB(A)). Specimens G and H were confirmed to have small variations in OA value with Specimen F as the reference. As a result, in the same way as when the perforated plate has vertical and vertical perforations, it is possible to reduce aerodynamic noise even when the direction of the perforated plate is changed by 90° and the horizontal perforations are changed to perforated folds, or when the folds are changed to perforated folds only. It was confirmed that the effect can be obtained. However, it was suggested that the aerodynamic noise reduction effect is slightly greater when the perforated plate is perforated.

(Other embodiments)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible as described below, which are also within the scope of the present invention.
(1) In this embodiment, the current collector 3 for Shinkansen was described as an example, but the present invention can also be applied to a current collector for conventional lines. In addition, in this embodiment, a single-arm type pantograph was described as an example of the current collector 3, but the present invention can also be applied to other types of pantographs such as diamond-shaped pantographs. Furthermore, in this embodiment, the case where the current collector 3 moves in the bending direction in which the intermediate hinge 13 is located on the front side of the traveling direction of the vehicle 2 has been described as an example. The present invention can also be applied to the case where the current collector 3 moves in the anti-flutter direction where the current collector 13 is positioned.

(2) In this embodiment, the ridge where a plurality of adjacent surfaces intersect is an example of the case where the aerodynamic noise is generated. The present invention can also be applied to sources. Similarly, in this embodiment, the upper edge portion 8e of the vertex cover 8 is taken as an example of the aerodynamic noise source of the current collector 3, but the present invention is not limited to the upper edge portion 8e. For example, the lower edge portion 8f of the vertex cover 8, the upper edge portion or lower edge portion of the intermediate hinge 13, the upper edge portion or lower edge portion of the windshield cover 18, or the joint portion between the windshield cover 18 and the insulator 19. The present invention can also be applied to the case of reducing aerodynamic noise generated from an aerodynamic noise source such as. Further, in this embodiment, a case in which the covering portion 22 is a separate member from the vertex cover 8 has been described as an example, but a case in which the covering portion 22 is formed integrally with the vertex cover 8, or a case in which the covering portion 22 is attached to another pantograph The present invention can also be applied to cases such as integral molding with members.

(3) In this embodiment, the case where the shape of the through-hole 22a is circular has been described as an example. However, the present invention can be applied. In this embodiment, the hole arrangement (pattern) of the through holes 22a is described as an example of a 60° staggered arrangement, but the hole arrangement (pattern) is an isosceles triangle with holes at each vertex. The present invention can also be applied to a 45° staggered arrangement. Furthermore, in this embodiment, a case where the covering portion 22 is fastened together with the top cover 8 to the boat support portion 7 by the fixing portion 23 has been described as an example, but the present invention is not limited to such a fastening method. . For example, the present invention can also be applied to a case where a female threaded portion that engages with the male threaded portion of the fixing portion 23 is formed on the side surface portion 8c of the top cover 8 and the covering portion 22 is fastened to the top cover 8 by the fixing portion 23. .

(4) In the first and third to eighth embodiments, the case where the cross-sectional shape of the bottom surfaces 21a and 21b of the gap portion 21 and the cross-sectional shape of the covering portion 22 are the same will be described as an example. However, the present invention can also be applied to a case in which the cross-sectional shape of the bottom surfaces 21a and 21b of the gap portion 21 and the cross-sectional shape of the cover portion 22 are arbitrarily combined. For example, the present invention can also be applied to the case where the cross-sectional shape of the bottom surface 21e of the gap portion 21 is formed into an arc shape and the cross-sectional shape of the cover portion 22 is formed into an angular shape. Similarly, the present invention can be applied to the case where the cross-sectional shape of the bottom surfaces 21a, 21b, 21e of the gap portion 21 is square, arc or triangular and the cross-sectional shape of the covering portion 22 is square. Further, in the eighth embodiment, the case where the aerodynamic noise reduction section 24 is made of porous material has been described as an example, but the present invention can also be applied to the case where it is made of sound absorbing material. Furthermore, in this embodiment, the case where the aerodynamic noise reduction portion 24 is a porous material with continuous pores has been described as an example, but the case where the aerodynamic noise reduction portion 24 is a mesh-like porous material is also applicable. can be applied.

REFERENCE SIGNS LIST 1 overhead wire 1a trolley wire 2 vehicle 2a vehicle body 3 current collector 4 slider 5 boat body 6 framework 7 boat support 8 apex cover (aerodynamic noise source)
8a upper surface portion 8b lower surface portion 8c side surface portion 8d rear surface portion 8e upper edge portion 8f lower edge portion 8g mounting portion 9 upper frame 11 lower frame 17 underframe 20A, 20B aerodynamic noise reduction structure 21 gap portion 21a, 21b bottom surface 21e bottom surface 22 Coating part 22a Through hole 22b Bone 23 Fixing part 24 Aerodynamic noise reduction part F Flow D Direction of movement

Claims (4)

An aerodynamic noise reduction structure for a current collector that reduces aerodynamic noise generated from the current collector,
a covering portion covering the aerodynamic noise source so as to form a gap between the current collector and the aerodynamic noise source;
the covering portion has a plurality of through-holes through which a flow flows into the gap and flows out from the gap;
An aerodynamic noise reduction structure for a current collector, characterized by: In the aerodynamic noise reduction structure of the current collector according to claim 1,
When the aerodynamic noise generating source is the vertex cover of the current collector, the gap is formed along the upper corner of the vertex cover;
An aerodynamic noise reduction structure for a current collector, characterized by: In the aerodynamic noise reduction structure of the current collector according to claim 1 or claim 2,
The bottom surface of the gap is formed as a flat surface, a curved surface, or an inclined surface,
the covering portion covers the bottom surface of the gap so as to form a predetermined gap with the bottom surface of the gap;
An aerodynamic noise reduction structure for a current collector, characterized by: In the aerodynamic noise reduction structure for a current collector according to any one of claims 1 to 3,
An aerodynamic noise reduction unit that reduces the aerodynamic noise while being accommodated in the gap,
the covering section covers the aerodynamic noise reduction section so as to form a predetermined gap with the aerodynamic noise reduction section;
An aerodynamic noise reduction structure for a current collector, characterized by:

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