JP2021069206A - Aerodynamic sound reduction structure of current collector - Google Patents

Abstract

To provide an aerodynamic sound reduction structure of a current collector capable of protecting an aerodynamic sound reduction unit without impairing aerodynamic sound reduction effect.SOLUTION: An aerodynamic sound reduction structure 21A reduces aerodynamic sound generated from an aerodynamic sound generation source of a current collector 3. The aerodynamic sound reduction unit 23 covers a surface of the aerodynamic sound generation source to reduce the aerodynamic sound. A protection unit 24 has a plurality of through holes 24a through which flow F flows into and out of the aerodynamic sound reduction unit 23, and covers a surface of the aerodynamic sound reduction unit 23 to protect the aerodynamic sound reduction unit 23. The aerodynamic sound reduction unit 23 covers a surface of the aerodynamic sound generation source of an apex cover 8 of the current collector 3. In the protective portion 24, an opening ratio of the through holes 24a is 30% or more and 60% or less. In the protective portion 24, inner diameters of the through holes 24a are 3.0 mm or more and 8.0 mm or less. The aerodynamic noise reducing unit 23 is a porous metal material. In the protection portion 24, the plurality of through holes 24a are arranged so that center lines L of the plurality of through holes 24a coincides with a direction of the flow F.SELECTED DRAWING: Figure 8

Description

The present invention relates to an aerodynamic sound reduction structure of a current collector that reduces aerodynamic sound generated from an aerodynamic sound generation source of the current collector.

(About reducing aerodynamic noise in Shinkansen pantographs)
Reducing the aerodynamic noise emitted from each part of the vehicle is an important issue for increasing the speed of the Shinkansen (registered trademark). The pantograph is the main aerodynamic sound source, and among the members of the pantograph, the boat body and the boat support part are the aerodynamic sound sources that make the largest contribution. Smoothing the cross-sectional shape and applying through holes are effective in reducing the aerodynamic noise of the hull, but that is not enough, and it is necessary to mitigate the interference of the flow of the hull and the hull support.

As one of the methods for alleviating the interference of the flow of the boat body and the boat support part, we propose a method of applying (pasting) a porous material with continuous pores on the surface of the apex cover of the boat support part. In the effect of reducing aerodynamic noise by attaching the surface of the porous material and its application to a current collector, the porous material is attached to the surface of the cylindrical specimen to reduce the aerodynamic noise (see, for example, Non-Patent Document 1). The conventional aerodynamic sound reduction structure is provided with a porous material having continuous pores for reducing aerodynamic sound on the surface of the object (see, for example, Patent Document 1). In reducing aerodynamic noise by applying a porous material to the boat support of a pantograph, we have proposed a method to reduce aerodynamic noise by embedding the porous material in the minimum necessary area (see, for example, Non-Patent Document 2). ..

(About application and installation method of porous material to the current car)
In the wind tunnel test, a urethane resin porous material that is easy to process is used, but in application to the current vehicle, it is necessary to use a metal porous material and firmly attach it to the object. Regarding the attachment of the porous metal material, there are techniques such as adhesion, riveting, and sequential lamination with the FRP base material. In the conventional installation structure of the porous metal material having a cell structure, the porous material is fixed to the non-fixing member by a rivet body penetrating the through hole of the porous material and the member to be fixed (see, for example, Patent Document 2). In the conventional mounting structure of a porous metal material, an FRP film-forming material is applied to the surface of the porous material to form a fixed layer, and the fixed layer and the fixed member are fixed with screws ( For example, see Patent Document 3). In the conventional method of applying a porous metal onto a non-fixing member, a bonding layer resin is impregnated into the surface of a molded panel of the porous metal and cured, and an FRP layer is formed on the surface of the bonding layer resin (for example). , Patent Document 4).

Takeyuki Sueki, 2 others, "Aerodynamic noise reduction effect by sticking the surface of a porous material and its application to current collectors", Railway Technical Research Institute, Kenyusha, 2008, Vol. 22, No. 5, p.11-16

Japanese Unexamined Patent Publication No. 2008-136332

Tsuyoshi Hikari, 3 others, "Reduction of aerodynamic noise by applying porous material to boat support of pantograph", 28th Environmental Engineering Symposium, Japan Society of Mechanical Engineers, July 11-12, 2018 ， No.18-10

Japanese Unexamined Patent Publication No. 2009-085406

Japanese Patent Application Laid-Open No. 2009-085407

Japanese Unexamined Patent Publication No. 2010-208287

The conventional cell structure, such as the installation structure of the porous metal material, is a technique for joining the base material and the porous material. Therefore, when the porous material is applied to the current vehicle, when an object collides with the surface of the porous material, there is a problem that the mounting strength of the porous material remains a problem.

An object of the present invention is to provide an aerodynamic sound reduction structure of a current collector capable of protecting an aerodynamic sound reduction unit without impairing the aerodynamic sound reduction effect.

The present invention solves the above problems by means of solutions as described below.
Although the description will be given with reference numerals corresponding to the embodiments of the present invention, the present invention is not limited to this embodiment.
The invention of claim 1 is an aerodynamic sound generation source (8d, 14e, 14f, 14g, 19f) of the current collector (3), as shown in FIGS. 1 to 4, 6 to 13 and 15 to 20. , 19g, 19h; 8e; 19i, 26e, 26f). It is an aerodynamic sound reduction structure of a current collector that reduces the aerodynamic sound, and covers the surface of the aerodynamic sound generation source to reduce the aerodynamic sound. The aerodynamic sound reduction unit (23) and the aerodynamic sound reduction unit have a plurality of through holes (24a) through which the flow (F) flows in and out, and the surface of the aerodynamic sound reduction unit is covered to cover the aerodynamic force. It is an aerodynamic sound reduction structure (21A-21C; 21D) of a current collector including a protection unit (24) that protects the sound reduction unit.

According to the second aspect of the present invention, in the aerodynamic sound reducing structure of the current collector according to the first aspect, as shown in FIGS. 1 to 4, 6 to 9 and 15 to 19, the aerodynamic sound reducing unit. Is an aerodynamic sound reduction structure (21A) of the current collector, which covers the surface of the aerodynamic sound generation source (8d; 8e) of the apex cover (8) of the current collector.

According to the invention of claim 3, in the aerodynamic sound reducing structure of the current collector according to claim 1, as shown in FIGS. 1 to 4, 6 and 10, the aerodynamic sound reducing unit is the current collector. It is an aerodynamic sound reduction structure (21B) of a current collector characterized by covering the surface of the aerodynamic sound generation source (14e to 14g) of the intermediate hinge cover (14).

According to the invention of claim 4, in the aerodynamic sound reduction structure of the current collector according to claim 1, as shown in FIGS. 1 to 4, 11 and 19, the aerodynamic sound reduction unit is the current collector. It is an aerodynamic sound reduction structure (21C) of a current collector characterized by covering the surface of the aerodynamic sound generation source (19f to 19h; 19i) of the windshield cover (19).

The invention of claim 5 is the aerodynamic sound reduction structure of the current collector according to claim 1, as shown in FIGS. 19 and 20, the aerodynamic sound reduction unit is a spindle cover (26) of the current collector. It is an aerodynamic sound reduction structure (21D) of a current collector characterized by covering the surface of the aerodynamic sound generation source (26e, 16f).

The invention of claim 6 is the aerodynamic sound reduction structure of the current collector according to any one of claims 1 to 5, wherein the protective portion has an aperture ratio of 30% or more of the through hole 60. It is a structure for reducing aerodynamic noise of a current collector, which is characterized by being less than or equal to%.

The invention of claim 7 is the aerodynamic sound reduction structure of the current collector according to any one of claims 1 to 5, wherein the protective portion has an inner diameter of 3.0 mm or more and 8.0 mm or less. It is a structure for reducing aerodynamic noise of a current collector, which is characterized in that.

The invention of claim 8 is characterized in that, in the aerodynamic sound reduction structure of the current collector according to any one of claims 1 to 7, the aerodynamic sound reduction is a porous metal material. It is an aerodynamic noise reduction structure of the current collector.

According to the invention of claim 9, in the aerodynamic sound reduction structure of the current collector according to any one of claims 1 to 8, as shown in FIGS. 13 (A) and 13 (B), the protection unit is The structure for reducing aerodynamic noise of a current collector is characterized in that the plurality of through holes are arranged so that the center lines (L) of the plurality of through holes coincide with the direction of the flow.

According to the present invention, the aerodynamic sound reducing portion can be protected without impairing the aerodynamic sound reducing effect.

It is a side view which shows typically the current collector provided with the aerodynamic sound reduction structure of the current collector which concerns on 1st Embodiment of this invention. It is a front view schematically showing the current collector provided with the aerodynamic sound reduction structure of the current collector which concerns on 1st Embodiment of this invention. It is a rear view which shows typically the current collector provided with the aerodynamic sound reduction structure of the current collector which concerns on 1st Embodiment of this invention. It is a top view which shows typically the current collector provided with the aerodynamic sound reduction structure of the current collector which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows typically the structure of the current collector provided with the aerodynamic sound reduction structure of the current collector which concerns on 1st Embodiment of this invention. It is a perspective view which shows roughly a part of the current collector provided with the aerodynamic sound reduction structure of the current collector which concerns on 1st Embodiment of this invention. It is a perspective view which shows typically the apex cover provided with the aerodynamic sound reduction structure of the current collector which concerns on 1st Embodiment of this invention. It is an external view which shows by breaking a part of the apex cover provided with the aerodynamic sound reduction structure of the current collector which concerns on 1st Embodiment of this invention, (A) is a plan view, (B) is a side view. is there. FIG. 8 is a cross-sectional view showing a state of being cut along the IX-IX line of FIG. 8, FIG. 8A is a cross-sectional view when the upper ridge angle portion and the lower ridge angle portion are rounded, and (B) and (C) are upper ridge angles. It is sectional drawing in the case where the portion and the lower ridge angle portion are corners. It is an external view which shows by breaking a part of the intermediate hinge cover which provided the aerodynamic sound reduction structure of the current collector which concerns on 1st Embodiment of this invention, (A) is a plan view, (B) is a side view. It is (C) bottom view. It is an external view which shows by breaking a part of the windshield cover provided with the aerodynamic sound reduction structure of the current collector which concerns on 1st Embodiment of this invention, (A) is a plan view, (B) is a side view. Yes, it is (C) bottom view. It is sectional drawing which shows typically the aerodynamic sound reduction structure of the current collector which concerns on 1st Embodiment of this invention. It is a top view of the protection part of the aerodynamic sound reduction structure of the current collector which concerns on 1st Embodiment of this invention, and (A) (C) is a top view when the through hole of the protection part is circular shape. (B) is a plan view when the through hole of the protective portion has a slit shape. It is a photograph for demonstrating the operation of the aerodynamic sound reduction part of the aerodynamic sound reduction structure of the current collector which concerns on 1st Embodiment of this invention, and (A) is the photograph which enlarges and shows the aerodynamic sound reduction part. (B) and (C) are contour diagrams of the flow field when the aerodynamic sound reduction unit is provided, and (E) and (F) are contour diagrams of the flow field when the aerodynamic sound reduction unit is not provided. It is a perspective view which shows typically the apex cover provided with the aerodynamic sound reduction structure of the current collector which concerns on 2nd Embodiment of this invention. It is an external view which shows by breaking a part of the apex cover provided with the aerodynamic sound reduction structure of the current collector which concerns on 2nd Embodiment of this invention, (A) is a plan view, (B) is a side view. is there. It is a vertical sectional view of the apex cover provided with the aerodynamic sound reduction structure of the current collector which concerns on 3rd Embodiment of this invention, and (A) is the sectional view when the upper ridge angle portion and the lower ridge angle portion are rounded. , (B) and (C) are cross-sectional views when the upper ridge angle portion and the lower ridge angle portion are corners. It is a side view which shows by breaking a part of the apex cover provided with the aerodynamic sound reduction structure of the current collector which concerns on 4th Embodiment of this invention. It is a side view which shows typically the current collector provided with the aerodynamic sound reduction structure of the current collector which concerns on 5th Embodiment of this invention. It is an external view which shows by breaking a part of the spindle cover which provided the aerodynamic sound reduction structure of the current collector which concerns on 5th Embodiment of this invention, (A) is a plan view, (B) is a side view. Yes, it is (C) bottom view. It is a schematic diagram which shows typically the wind tunnel test apparatus used for the aerodynamic sound reduction effect test by the aerodynamic sound reduction structure of the current collector which concerns on embodiment of this invention. It is a photograph which shows the test situation of the aerodynamic sound reduction effect test by the aerodynamic sound reduction structure of the current collector which concerns on the Example of this invention. It is a top view of the punching metal used for the aerodynamic sound reduction effect test by the aerodynamic sound reduction structure of the current collector according to the Example of this invention, (A) is a top view which shows arrangement of a through hole, (B). Is a plan view when the arrangement of the through holes is made to match the direction of the flow, and (C) is a plan view when the arrangement of the through holes is orthogonal to the direction of the flow. It is a graph which shows the test result of the aerodynamic sound reduction effect test by the aerodynamic sound reduction structure of the current collector which concerns on the Example of this invention.

(First Embodiment)
Hereinafter, the first embodiment of the present invention will be described in detail with reference to the drawings.
The overhead wire 1 shown in FIGS. 1 to 3, 5 and 6 is an overhead train line erected over the railroad track. The overhead wire 1 is supported by support points at predetermined intervals. The trolley wire 1a is an electric wire to which the current collector 3 contacts and moves. The trolley wire 1a supplies a load current to the vehicle 2 by sliding the current collector 3. The vehicle 2 shown in FIGS. 1 to 3 and 5 is an electric vehicle such as a train or an electric locomotive. Vehicle 2 is, for example, a railroad vehicle such as a Shinkansen that travels 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 guiding electric power from the trolley wire 1a to the vehicle 2. The current collector 3 includes a boat body (current collector boat) 4 shown in FIGS. 1 to 6, a sliding plate 5, a framework 6, a main shaft 15 shown in FIG. 5, a lever portion 16, and a main spring 17. The underframe 18 shown in FIGS. 1 to 5 and 11 and the windshield cover 19 and the insulator 20 shown in FIGS. 1 to 3, 5 and 11, and 1 to 4 and 6 to 12 are shown. It is equipped with aerodynamic sound reduction structures 21A to 21C and the like. As shown in FIGS. 1 and 6, the current collector 3 shown in FIGS. 1 to 6 is a single-arm pantograph that is asymmetric with respect to _{the traveling direction D 1 of the vehicle 2 and can be used in one direction or both directions.} Is. As shown in FIG. 1, when the current collector 3 is used in the fluttering direction in which the intermediate hinge 13 is located on the front side in the traveling direction of the vehicle 2, the aerodynamic noise becomes relatively small, and the intermediate hinge is located on the rear side in the traveling direction of the vehicle 2. When used in the anti-fluttering direction in which 13 is located, the aerodynamic sound becomes relatively loud. The current collector 3 shown in FIGS. 1 and 6 is moving in the fluttering direction in which the intermediate hinge 13 is located on the front side in the traveling direction of the vehicle 2.

The boat body 4 shown in FIGS. 1 to 6 is a member that supports the sliding plate 5. The hull 4 is generally an elongated metal columnar member extending in a direction orthogonal to the trolley line 1a (sleeper direction). As shown in FIGS. 1 and 5, the hull 4 is symmetrical with respect to the central axis of the hull 4, and both front and rear are formed in the same shape. The hull 4 is formed of a streamlined or curved surface having a cross-sectional shape similar to a streamlined shape in order to prevent the flow (air flow) F from peeling off as much as possible, and is formed of a smooth curve. The hull 4 has a smoothed hull cross-sectional shape so that both aerodynamic noise reduction and lift characteristic stabilization can be achieved by, for example, a method that combines computational fluid dynamics (CFD) analysis and optimization methods. It is a smoothed boat body (smooth shape boat body). The hull 4 shown in FIGS. 1 to 6 is, for example, a Shinkansen (high-speed) pantograph hull with improved tracking performance for the trolley wire 1a. The hull 4 includes a horn 4a and the like shown in FIGS. 1 to 4 and 6. When the vehicle 2 passes through the turnout, the horn 4a prevents an interruption to the trolley line 1a in a direction different from the traveling direction of the vehicle 2 among the two trolley lines 1a intersecting above the turnout. It is a member for. The horn 4a is a metal member that protrudes from both ends in the length direction of the hull 4 and has a tip that is curved downward as shown in FIGS. 2, 3 and 6. ..

The sliding plate 5 shown in FIGS. 1 to 6 is a member that slides on the trolley wire 1a. As shown in FIGS. 2, 3 and 6, the sliding plate 5 is a metal or carbon plate-shaped member extending in a direction (sleeper direction) orthogonal to _{the traveling direction D 1 of the vehicle 2.} The sliding plate 5 is a separate part manufactured separately from the boat body 4, and is attached to the upper part of the boat body 4 in a state where a plurality of the sliding plate 5 are arranged in the length direction (sleeper direction) of the boat body 4. .. The sliding plate 5 is supported by an elastic body such as a spring so that it can be displaced relative to the boat body 4.

The framework 6 shown in FIGS. 1 to 6 is a member that supports the boat body 4. The framework 6 includes a link mechanism that can move in the vertical direction while supporting the hull 4. The framework 6 includes a boat support portion 7 shown in FIGS. 1 to 9, a vertex cover 8, an upper frame 9 shown in FIGS. 1 to 8, a boat support link (balance bar) 10 shown in FIG. 5, and FIG. The lower frame 11 shown in FIG. 6, the balancing rod 12 shown in FIG. 5, the intermediate hinge (bent portion) 13 shown in FIGS. 1 to 6 and 10, the intermediate hinge cover 14 and the like are provided. The framework 6 is raised by the urging force of the main spring 17 shown in FIG. 5 when in use, and is lowered by the driving force generated by the cylinder device against the urging force of the main spring 17 when not in use (when folded). ..

The boat support portion 7 shown in FIGS. 1 to 9 is a portion that supports the boat body 4. The boat support portion 7 pushes up the boat body 4 horizontally with respect to the overhead wire 1 and gives the boat body 4 a cushioning action by a spring. The boat support portion 7 maintains the equilibrium of the boat body 4 and improves the followability to the trolley wire 1a. As shown in FIGS. 1 to 8, the boat support portion 7 is supported by the top of the upper frame 9.

The apex cover 8 shown in FIGS. 1 to 9 is a member that covers the boat support portion 7. As shown in FIG. 5, the apex cover 8 covers a hinge portion (apex hinge portion) that rotatably connects the upper frame 9, the boat support link 10, and the boat support portion 7, and is covered with FIGS. 1 and 6. And, as shown in FIG. 8, it is formed in a shape that does not obstruct the flow F. The apex cover 8 prevents the flow F from entering the boat support portion 7 and generating a loud aerodynamic noise, and also prevents the air resistance from increasing. The apex cover 8 is, for example, a covering member made of nonflammable or flame-retardant metal or fiber reinforced plastic (FRP). As shown in FIG. 9, the apex cover 8 is divided into an upper cover 8A having a substantially inverted U-shaped cross section and a lower cover 8B having a substantially U-shaped cross section that is detachably joined to the upper cover 8A. It is possible. The apex cover 8 has a structure that covers the entire surface of the boat support portion 7 by covering the upper cover 8A and the lower cover 8B from above and below the boat support portion 7. As shown in FIG. 8, the apex cover 8 includes an upper portion 8a forming an upper inclined surface of the apex cover 8, a lower portion 8b forming a lower inclined surface of the apex cover 8, and both side surfaces of the apex cover 8. The side portion 8c constituting the above, the upper ridge angle portion (upper edge portion) 8d where the upper portion 8a and the side portion 8c intersect, and the lower ridge angle portion (lower edge portion) 8e where the lower portion 8b and the side portion 8c intersect. I have. The apex cover 8 is a polyhedron composed of an upper portion 8a, a lower portion 8b, and a side portion 8c, and two adjacent surfaces of the polyhedron intersect at an upper ridge angle portion 8d and a lower ridge angle portion 8e. In the vertex cover 8, for example, as shown in FIG. 9 (A), the upper ridge angle portion 8d and the lower ridge angle portion 8e are rounded, or as shown in FIG. 9 (B), the upper ridge angle portion 8d and the lower side are rounded. The side ridge angle portion 8e is formed at the corner. As shown in FIG. 9A, the apex cover 8 has the aerodynamic sound reducing portion 23 attached relatively thinly along the shape of the upper ridge angle portion 8d when the upper ridge angle portion 8d is rounded. .. On the other hand, as shown in FIGS. 9B and 9C, when the upper ridge angle portion 8d is formed at the corner of the apex cover 8, the aerodynamic sound reducing portion 23 is attached to the upper ridge angle portion 8d relatively thickly. The shape of the corner is composed of. On the apex cover 8, as shown in FIG. 9 (B), the aerodynamic sound reducing portion 23 is attached in an L shape along the upper portion and the side portion of the upper ridge angle portion 8d, or as shown in FIG. 9 (C). The aerodynamic sound reducing portion 23 is attached in a plate shape along the side portion of the upper ridge angle portion 8d.

The upper frame 9 shown in FIGS. 1 to 8 is a member rotatably connected to the boat support portion 7. The upper frame 9 is a tubular member forming the upper half of the framework 6, and houses the boat support link 10 shown in FIG. 5 inside. In the upper frame 9, 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 4 and the boat support portion 7 in a predetermined posture. In the boat support link 10, 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 to 6 is a member rotatably connected to the underframe 18. The lower frame 11 is a tubular member that constitutes the lower half of the framework 6, and houses the balancing rod 12 shown in FIG. 5 inside. In the lower frame 11, 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 15. The balance rod 12 is a member for adjusting a locus for vertically displacing the boat body 4. In the balancing rod 12, one end of the balancing rod 12 is rotatably connected to the upper frame 9, and the other end of the balancing rod 12 is rotatably connected to the spindle 15. The intermediate hinge 13 shown in FIGS. 1 to 6 and 10 is a portion that rotatably connects the upper frame 9 and the lower frame 11. The intermediate hinge 13 functions as a joint portion that connects the upper frame 9 and the lower frame 11.

The intermediate hinge cover 14 shown in FIGS. 1 to 6 and 10 is a member that covers the intermediate hinge 13. As shown in FIG. 5, the intermediate hinge cover 14 covers a hinge portion that rotatably connects the upper frame 9 and the boat support link 10 with the lower frame 11 and the balancing rod 12, and covers FIGS. 1, 6 and 6. As shown in FIG. 10, the shape is formed so as not to obstruct the flow F. The intermediate hinge cover 14 prevents the flow F from entering the intermediate hinge 13 and generating a loud aerodynamic noise, and also prevents the air resistance from increasing. The intermediate hinge cover 14 is, for example, a covering member made of FRP. As shown in FIG. 10, the intermediate hinge cover 14 has an upper portion 14a forming an upper inclined surface of the intermediate hinge cover 14 and an upper portion forming an upper inclined surface of the intermediate hinge cover 14 and inclining in the direction opposite to the upper portion 14a. 14b, a lower portion 14c forming a lower inclined surface of the intermediate hinge cover 14, side portions 14d forming both side surfaces of the intermediate hinge cover 14, and an upper ridge angle portion where the upper portions 14a, 14b and the side portion 14d intersect. (Upper edge portion) 14e and 14f, and a lower ridge angle portion (lower edge portion) 14g where the lower portion 14c and the side portion 14d intersect are provided. The intermediate hinge cover 14 is a polyhedron composed of an upper portion 14a, 14b, a lower portion 14c, and a side portion 14d, and two adjacent surfaces of the polyhedron intersect at the upper ridge angle portions 14e, 14f and the lower ridge angle portion 14g. The intermediate hinge cover 14 is rounded at the upper ridge corners 14e and 14f and the lower ridge 14g.

The spindle 15 shown in FIG. 5 is a member that raises and lowers the framework 6. The spindle 15 operates in conjunction with the framework 6 and moves the framework 6 up and down by rotating in the forward and reverse directions. The spindle 15 is rotatably supported by the underframe 18, and rotates integrally with the lower end of the lower frame 11. The lever portion 16 is a portion that converts linear motion into rotary motion. The lever portion 16 rotates integrally with the spindle 15 with the spindle 15 as a fulcrum. The main spring 17 is a member that applies an ascending force to the framework 6. The main spring 17 is a push-up spring that urges the main shaft 15 so that the main shaft 15 rotates and the frame 6 rises. The main spring 17 has one end of the main spring 17 rotatably attached to the underframe 18. It is connected, and the other end of the main spring 17 is rotatably connected to the lever portion 16.

The underframe 18 shown in FIGS. 1 to 5 and 11 is a member that supports the framework 6. As shown in FIG. 5, the underframe 18 is installed on the roof of the vehicle body 2a via the insulator 20 in a state of supporting the base of the framework 6. The underframe 18 supports an elevating mechanism portion that elevates and elevates the framework 6 such as the main shaft 15, the lever portion 16, and the main spring 17.

The windshield cover 19 shown in FIGS. 1 to 5 and 11 is a member that covers the underframe 18. As shown in FIG. 5, the windshield cover 19 covers the main shaft 15, the lever portion 16, the main spring 17, the underframe 18, and the like, and does not obstruct the flow F as shown in FIGS. 1, 4, and 11. It is formed in such a shape. The windshield cover 19 prevents the flow F from entering the underframe 18 and generating a loud aerodynamic noise, and also prevents the air resistance from increasing. The windshield cover 19 is, for example, a covering member made of FRP. As shown in FIG. 11, the windshield cover 19 includes an upper portion 19a forming an upper inclined surface of the windshield cover 19 and an upper portion 19b forming an upper inclined surface of the windshield cover 19 and inclining in a direction opposite to the upper portion 19a. , The lower portion 19c forming the lower inclined surface of the windshield cover 19, the lower portion 19d forming the lower inclined surface of the windshield cover 19 and inclining in the direction opposite to the lower portion 19c, and both side surfaces of the windshield cover 19. The upper ridge angle portion (upper edge portion) 19f where the constituent side portions 19e, the upper portions 19a, 19b and the side portions 19e intersect, and the lower ridge angle portion (lower side edge portion) where the lower portions 19c, 19d and the side portion 19e intersect. It includes 19 g and 19 h around the joint portion around the joint portion where the windshield cover 19 joins with the gable 20. The windshield cover 19 is a polyhedron composed of an upper portion 19a, 19b, a lower portion 19c, 19d, and a side portion 19e, and two adjacent surfaces of the polyhedron intersect at an upper ridge angle portion 19f and a lower ridge angle portion 19g. The windshield cover 19 is rounded at the upper ridge angle portion 19f and the lower ridge angle portion 19g.

The insulator 20 shown in FIGS. 1 to 3, 5 and 11 is a member that electrically insulates between the vehicle body 2a and the underframe 18. The insulator 20 shown in FIGS. 1 to 3 and 11 is a low noise insulator formed in a shape having an effect of suppressing the generation of aerodynamic sound. As shown in FIG. 11C, the insulator 20 has a substantially elliptical cross-sectional shape when cut in a horizontal plane in order to suppress the emission of vortices generated at the trailing edge of the insulator 20. The insulator 20 supports the bottom surfaces of the underframe 18 near both edges.

The aerodynamic sound reduction structures 21A to 21C shown in FIGS. 1 to 4 and 6 to 12 are structures for reducing the aerodynamic sound generated from the aerodynamic sound generation source of the current collector 3. Here, the aerodynamic sound generating portion is, for example, a ridge angle portion where a plurality of adjacent surfaces intersect, a peripheral portion of a portion where a plurality of members are joined or close to each other, and the like. The aerodynamic sound reduction structure 21A shown in FIGS. 1 to 4 and 6 to 9 reduces the aerodynamic sound generated from the upper ridge angle portion 8d, which is the aerodynamic sound generation source of the apex cover 8. As shown in FIGS. 6 and 7, the aerodynamic sound reduction structure 21A is formed along the upper ridge angle portion 8d. The aerodynamic sound reduction structure 21B shown in FIGS. 1 to 4, 6 and 10 reduces the aerodynamic sound generated from the upper ridge angle portions 14e and 14f and the lower ridge angle portions 14g, which are the aerodynamic sound generation sources of the intermediate hinge cover 14. To do. As shown in FIG. 10, the aerodynamic sound reduction structure 21B is formed along the upper ridge angle portions 14e and 14f and the lower ridge angle portion 14g. The aerodynamic sound reduction structure 21C shown in FIGS. 1 to 4 and 11 reduces the aerodynamic sound generated from the upper ridge angle portion 19f, the lower ridge angle portion 19g, and the joint portion peripheral 19h, which are the aerodynamic sound generation sources of the windshield cover 19. .. The aerodynamic sound reduction structure 21C is formed along the upper ridge angle portion 19f and the lower ridge angle portion 19g as shown in FIG. 11 (B), and is formed around the joint portion 19h as shown in FIG. 11 (C). It is formed.

The aerodynamic sound reduction structures 21A to 21C include a housing unit 22 shown in FIGS. 8 to 10 and 12, an aerodynamic sound reduction unit 23, and a protection unit 24 shown in FIGS. 1 to 4 and 6 to 13. 9 and the fixing portion 25 shown in FIG. 12 are provided. The aerodynamic sound reduction structures 21A to 21C protect the aerodynamic sound reduction unit 23 by the protection unit 24 when an object impacts the aerodynamic sound reduction unit 23, and hinders the aerodynamic sound reduction effect of the aerodynamic sound reduction unit 23. Without doing so, the mounting strength of the aerodynamic noise reducing unit 23 is improved.

The accommodating unit 22 shown in FIGS. 8 to 10 and 12 is a means for accommodating the aerodynamic sound reducing unit 23. The accommodating portion 22 includes the upper ridge angle portion 8d of the apex cover 8 shown in FIGS. 7 and 8, the upper ridge angle portions 14e and 14f and the lower ridge angle portion 14g of the intermediate hinge cover 14 shown in FIG. 10, and the windshield shown in FIG. It is formed along the upper ridge angle portion 19f, the lower ridge angle portion 19g, and the periphery 19h of the joint portion of the cover 19. As shown in FIG. 12, the accommodating portion 22 is a recess formed at a predetermined depth. The accommodating portion 22 is formed by machining such as cutting, for example.

The aerodynamic sound reduction unit 23 shown in FIGS. 8 to 10 and 12 is a means for reducing the aerodynamic sound by covering the surface of the aerodynamic sound generation source. The aerodynamic sound reduction unit 23 includes the surface of the aerodynamic sound source of the apex cover 8 of the current collector 3 shown in FIGS. 7 and 8 and the aerodynamic sound source of the intermediate hinge cover 14 of the current collector 3 shown in FIG. The surface is covered with the surface of the aerodynamic sound generation source of the windshield cover 19 of the current collector 3 shown in FIG. The aerodynamic sound reducing unit 23 includes the upper ridge angle portion 8d of the apex cover 8 shown in FIGS. 7 and 8, the upper ridge angle portions 14e and 14f and the lower ridge angle portion 14g of the intermediate hinge cover 14 shown in FIG. It is attached to the upper ridge angle portion 19f, the lower ridge angle portion 19g, and the periphery 19h of the joint portion of the windshield cover 19 shown. The aerodynamic sound reducing unit 23 has a three-dimensional skeletal network structure such as continuous pores in which minute holes are formed in the walls of the pores and the pores communicate with each other. The aerodynamic noise reducing unit 23 is a hard porous material such as a flame-retardant or non-flammable metal porous material. The aerodynamic sound reducing portion 23 is attached to the accommodating portion 22 with an adhesive or the like, and is filled and embedded in the accommodating portion 22.

The aerodynamic sound reduction unit 23 is generally selected to have a small cell when the sound absorption effect is intended, but when the aerodynamic sound reduction is intended, the cell is larger than when the sound absorption effect is intended. The one is selected. In the aerodynamic sound reduction unit 23, if the cell range representing the number of pores on a straight line having a length of 25 mm (1 inch) is less than 6 and exceeds 55, the noise level cannot be expected to decrease. Therefore, the cell range is 6 or more and 55 or less. Those having a cell range of 11 or more and 16 or less are particularly preferable. The aerodynamic noise reducing unit 23 has a porosity (pores) which is a ratio of the volume of a solid material (bulk material) having the same shape as the porous material to the volume of the air portion of the porous material, even if the cell range is appropriate. When the rate or porosity) is low, the noise level cannot be expected to decrease, so that a high porosity of 80% or more is preferable.

The protection unit 24 shown in FIGS. 1 to 4 and 6 to 13 is a means for covering the surface of the aerodynamic sound reduction unit 23 to protect the aerodynamic sound reduction unit 23. As shown in FIGS. 7 to 10, 12 and 13, the protection unit 24 has a plurality of through holes 24a through which airflow flows in and out of the aerodynamic sound reduction unit 23. As shown in FIGS. 9 to 11, the protective portion 24 is formed in a shape along the surfaces of the apex cover 8, the intermediate hinge cover 14, and the windshield cover 19, and the apex cover 8, the intermediate hinge cover 14, and the windshield cover 19 are formed. It is mounted over the surface of 19. In the protective portion 24, for example, as shown in FIGS. 13 (A) and 13 (C), the through hole 24a is formed in a circular shape, or as shown in FIG. 13 (B), the through hole 24a has a slit shape (long hole). Shape). As shown in FIG. 12, the protective portion 24 includes the apex cover 8, the intermediate hinge cover 14, and the intermediate hinge cover so that the surfaces of the apex cover 8, the intermediate hinge cover 14, and the windshield cover 19 are at the same height as the surface of the protective portion 24. It is adhered to the surfaces of 14 and the windshield cover 19 with an adhesive or the like. The protective portion 24 is, for example, a perforated plate (perforated plate) such as a punched metal made of an aluminum alloy or stainless steel. When the opening ratio of the through hole 24a is less than 30%, the aerodynamic noise reduction effect of the protective portion 24 is reduced, and when the opening ratio of the through hole 24a exceeds 60%, the strength is insufficient. Therefore, the through hole 24a is opened. It is preferable to set the pore ratio to 30% or more and 60% or less. The protective portion 24 preferably has an inner diameter of the through hole 24a set to 3.0 mm or more and 8.0 mm or less in order to maintain the mounting strength without impairing the aerodynamic noise reduction effect. As shown in FIGS. 13 (A) and 13 (B), a plurality of protective portions 24 are provided so that the center lines L of the plurality of through holes 24a coincide with the direction of the flow F, or as shown in FIG. 13 (C). A plurality of through holes 24a are arranged so that the center line L of the through holes 24a is orthogonal to the direction of the flow F.

The fixing portion 25 shown in FIGS. 9 and 12 is a means for fixing the protection portion 24. The fixing portion 25 detachably fixes the protective portion 24 to the apex cover 8, the intermediate hinge cover 14, and the windshield cover 19 so as to sandwich the aerodynamic sound reducing portion 23 between the protective portion 24 and the accommodating portion 22. The fixing portion 25 is, for example, a fastening member such as a bolt having a male threaded portion that meshes with the female threaded portion of the apex cover 8, the intermediate hinge cover 14, and the windshield cover 19. As shown in FIGS. 7 to 11, the fixing portion 25 is inserted into the through holes formed at the four corners of the aerodynamic noise reducing portion 23 and the protective portion 24, and the apex cover 8, the intermediate hinge cover 14, and the windshield cover 19 are inserted. The aerodynamic sound reduction unit 23 and the protection unit 24 are fixed to the.

Next, the operation of the aerodynamic sound reduction structure of the current collector according to the first embodiment of the present invention will be described.
When the surface of the cylinder of the flow field shown in FIG. 14 (A) does not have the aerodynamic sound reducing portion 23, it is slightly upstream of the maximum width portion of the cylinder as shown in FIGS. 14 (B) and 14 (C). At the peeling point on the surface of the cylinder, the flow F in the direction of the arrow is peeled off, and air alternately wraps around the downstream side of the cylinder. Therefore, Karman vortices are generated by the interaction of vortices generated from the peeling shear layer on the surface of the cylinder, and noise and vibration caused by the Karman vortices are generated. On the other hand, when the surface of the cylinder of the flow field shown in FIG. 14 (A) is provided with the aerodynamic sound reducing unit 23, the flow flows inside the aerodynamic sound reducing unit 23 as shown in FIGS. 14 (D) and 14 (E). F flows in, and the flow F in the aerodynamic noise reducing portion 23 naturally flows out from the low pressure portion such as near the peeling point. As a result, the flow field is stabilized, the emission of vortices is weakened, and the aerodynamic noise is reduced.

_{When the vehicle 2 travels in the traveling direction D 1} shown in FIGS. 1 to 4, the current flows at the linear or two-dimensional upper ridge angles 8d, 14e, 14f, 19f and the lower ridges 14g, 19g of the current collector 3. Peeling of F occurs. As shown in FIG. 12, the flow F flows into the aerodynamic sound reduction unit 23 from the high-pressure portion such as the stagnation point through the through hole 24a of the protection unit 24, and the flow F in the aerodynamic noise reduction unit 23 is near the peeling point. Naturally flows out from the low pressure portion of the above through the through hole 24a of the protection portion 24. As a result, the flow field is stabilized, the emission of vortices is weakened, and the aerodynamic noise is reduced. Since the protection unit 24 covers the surface of the aerodynamic sound reduction unit 23, the object does not directly collide with the aerodynamic sound reduction unit 23, the aerodynamic sound reduction unit 23 is protected by the protection unit 24, and the aerodynamic sound reduction unit 23 is protected. The mounting strength of the is improved.

The aerodynamic noise reduction structure of the current collector according to the first embodiment of the present invention has the following effects.
(1) In this first embodiment, the surface of the aerodynamic sound generation source is covered, the aerodynamic sound reduction unit 23 reduces the aerodynamic sound, and the flow F flows into and out of the aerodynamic sound reduction unit 23. The protection unit 24 has 24a, the surface of the aerodynamic sound reduction unit 23 is covered by the protection unit 24, and the aerodynamic sound reduction unit 23 is protected by the protection unit 24. Therefore, even if an object impacts the surface of the aerodynamic sound reduction unit 23, the aerodynamic sound reduction unit 23 is protected by the protection unit 24, and the aerodynamic sound reduction effect is not impaired by the aerodynamic sound reduction unit 23. The mounting strength of the portion 23 can be improved. Further, the fluid (air) can be exchanged with the surface of the aerodynamic sound reducing unit 23 through the through hole 24a of the protective unit 24, and the aerodynamic sound reducing effect can be maintained. Further, even in a portion where it is difficult to fix the aerodynamic noise reducing portion 23 only with the adhesive, the aerodynamic noise reducing portion 23 can be reliably fixed by the protective portion 24.

(2) In this first embodiment, the aerodynamic sound reducing unit 23 covers the surface of the aerodynamic sound generating source of the apex cover 8 of the current collector 3. The three-dimensional or curved tip of the current collector 3 does not affect the aerodynamic sound so much, and when the aerodynamic sound reduction structures 21A to 21C are applied to such a three-dimensional or curved tip, the aerodynamic sound reduction structure 21A to 21C is applied. , It is difficult to process the aerodynamic noise reduction structures 21A to 21C. In this first embodiment, the aerodynamic sound reduction structure 21A is applied to the linear or two-dimensional upper ridge angle portion 8d where it is presumed that the flow F is separated. Therefore, by covering the minimum region of the aerodynamic sound generation source with the aerodynamic sound reduction unit 23, the aerodynamic sound generated from the upper ridge angle portion 8d, which is the aerodynamic sound generation source of the apex cover 8, can be reduced. Further, the minimum area where the aerodynamic sound is generated is covered by the aerodynamic sound reducing unit 23.

(3) In this first embodiment, the aerodynamic sound reducing unit 23 covers the surface of the aerodynamic sound generating source of the intermediate hinge cover 14 of the current collector 3. Therefore, the aerodynamic sound generated from the upper ridge angle portions 14e and 14f and the lower ridge angle portion 14g, which are the sources of the aerodynamic sound of the intermediate hinge cover 14, can be reduced.

(4) In the first embodiment, the aerodynamic sound reducing unit 23 covers the surface of the aerodynamic sound generating source of the windshield cover 19 of the current collector 3. Therefore, the aerodynamic sound generated from the upper ridge angle portion 19f and the lower ridge angle portion 19g, which are the sources of the aerodynamic sound of the windshield cover 19, can be reduced. Further, the aerodynamic noise generated by the interference flow between the windshield cover 19 and the wheel 20 can be alleviated by the aerodynamic noise reducing portion 23 around the joint portion 19h.

(5) In this first embodiment, the aerodynamic sound reducing portion 23 is a porous metal material. Therefore, the flow F flows into the inside of the porous material, and the flow F in the porous material can be naturally discharged from the low pressure portion such as near the peeling point. As a result, the flow field can be stabilized, the emission of vortices can be weakened, and the aerodynamic noise can be reduced.

(6) In this first embodiment, the plurality of through holes 24a are arranged so that the center lines of the plurality of through holes 24a of the protection portion 24 coincide with the direction of the flow F. Therefore, the aerodynamic sound reduction effect can be further improved.

(Second Embodiment)
In the following, the same parts as those shown in FIGS. 1 to 13 are designated by the same reference numerals and detailed description thereof will be omitted.
The aerodynamic sound reduction structure 21A shown in FIGS. 15 and 16 is formed along the upper portion 8a and the upper ridge angle portion 8d of the apex cover 8. As shown in FIG. 16, the accommodating portion 22 is formed along the upper portion 8a and the upper ridge angle portion 8d of the apex cover 8. Unlike the aerodynamic sound reduction unit 23 shown in FIGS. 8 and 9, the aerodynamic sound reduction unit 23 shown in FIGS. 15 and 16 is attached to the upper ridge angle portion 8d and the upper portion 8a of the apex cover 8. This second embodiment has the same effect as the first embodiment.

(Third Embodiment)
The apex cover 8 shown in FIG. 17 has a substantially U-shaped cross section and can be attached and detached from under the boat support portion 7. The apex cover 8 has a structure that covers the lower surface and both side surfaces of the boat support portion 7 by covering the boat support portion 7 from below. In the apex cover 8, for example, as shown in FIG. 17 (A), the upper ridge angle portion 8d and the lower ridge angle portion 8e are rounded, or as shown in FIGS. 17 (B) and 17 (C), the upper ridge angle portion is formed. 8d and the lower ridge angle portion 8e are formed at the corners. The aerodynamic sound reduction unit 23 is attached to the apex cover 8 shown in FIG. 17, similarly to the apex cover 8 shown in FIG. The protective portion 24 has a substantially inverted U-shape in cross section, and includes a sandwiching portion 24b sandwiched between the side surface of the boat support portion 7 and the inner side surface of the apex cover 8. The protective portion 24 is detachably fixed to the apex cover 8 by the fixing portion 25 in a state where the sandwiching portion 24b is bitten between the side surface of the boat support portion 7 and the inner side surface of the apex cover 8. This third embodiment has the same effect as that of the first embodiment.

(Fourth Embodiment)
The current collector 3 shown in FIG. 18 is moving in the traveling direction D _{2 in the direction opposite to the traveling direction D 1 of the} vehicle 2 shown in FIG. 1, and the intermediate hinge 13 is located behind the traveling direction in the anti-fluttering direction. Have moved to. The aerodynamic sound reduction unit 23 shown in FIG. 18 covers the surface of the aerodynamic sound generation source of the apex cover 8 of the current collector 3. The aerodynamic sound reduction structure 21A reduces the aerodynamic sound generated from the upper ridge angle portion 8d and the lower ridge angle portion 8e, which are the aerodynamic sound generation sources of the apex cover 8. The aerodynamic sound reduction structure 21A is formed along the upper ridge angle portion 8d and the lower ridge angle portion 8e. The accommodating portion 22 is formed along the upper ridge angle portion 8d and the lower ridge angle portion 8e of the apex cover 8. The aerodynamic sound reducing portion 23 is attached to the upper ridge angle portion 8d and the lower ridge angle portion 8e of the apex cover 8. In the fourth embodiment of the present invention, in addition to the effects of the first to third embodiments, the current collector 3 is a single-arm pantograph that can be used in _{both directions (travel directions D 1} , D _2). In this case, the aerodynamic sound generated from the upper ridge angle portion 8d and the lower ridge angle portion 8e can be reduced.

(Fifth Embodiment)
The windshield cover 19 shown in FIG. 19 includes a proximity portion peripheral 19i around a proximity portion in which the windshield cover 19 and the spindle cover 26 are close to each other. The spindle cover 26 shown in FIGS. 19 and 20 is a member that covers the spindle 15. The spindle cover 26 covers a connecting portion that connects the lower frame 11 and the spindle 15, and is formed in a shape that does not obstruct the flow F. The spindle cover 26 prevents the flow F from entering the underframe 18 and generating a loud aerodynamic noise, and also prevents the air resistance from increasing. The spindle cover 26 is, for example, a covering member made of FRP. The spindle cover 26 is a curved portion that constitutes an upper portion 26a that constitutes the upper surface of the spindle cover 26, a lower portion 26b that constitutes the lower inclined surface of the spindle cover 26, and a curved surface that connects the upper portion 26a and the lower portion 26b. The upper side where the 26c, the side portion 26d forming the side surface of the main shaft cover 26, the lower ridge angle portion (lower edge portion) 26e where the lower portion 26b and the side portion 26d intersect, and the curved portion 26c and the side portion 26d intersect. It is provided with a ridge angle portion (upper edge portion) 26f. The spindle cover 26 is composed of an upper portion 26a, a lower portion 26b, a curved portion 26c and a side portion 26d, and adjacent planes and curved surfaces intersect at the lower ridge angle portion 26e and the upper ridge angle portion 26f. The spindle cover 26 is rounded at the lower ridge angle portion 26e and the upper ridge angle portion 26f.

The aerodynamic sound reduction structure 21C shown in FIG. 19 reduces the aerodynamic sound generated from the vicinity 19i, which is the aerodynamic sound generation source of the windshield cover 19. The aerodynamic sound reduction structure 21C is formed along the vicinity 19i of the proximity portion. The aerodynamic sound reduction structure 21D shown in FIGS. 19 and 20 is a structure that reduces the aerodynamic sound generated from the aerodynamic sound generation source of the current collector 3. The aerodynamic sound reduction structure 21D reduces the aerodynamic sound generated from the lower ridge angle portion 26e and the upper ridge angle portion 26f, which are the aerodynamic sound generation sources of the spindle cover 26. As shown in FIGS. 19 and 20, the aerodynamic sound reduction structure 21D is formed along the lower ridge angle portion 26e and the upper ridge angle portion 26f. As shown in FIGS. 12 and 20, the aerodynamic sound reduction structure 21D includes an accommodating unit 22, an aerodynamic sound reduction unit 23, a protective unit 24, a fixing unit 25, and the like. The aerodynamic sound reduction structure 21D protects the aerodynamic sound reduction unit 23 by the protection unit 24 when an object impacts the aerodynamic sound reduction unit 23, without hindering the aerodynamic sound reduction effect of the aerodynamic sound reduction unit 23. , The mounting strength of the aerodynamic noise reducing unit 23 is improved. The accommodating portion 22 shown in FIGS. 12 and 20 is formed along the vicinity 19i of the proximity portion of the windshield cover 19 shown in FIG. 19 and the lower ridge angle portion 26e and the upper ridge angle portion 26f of the spindle cover 26 shown in FIG. ing.

As shown in FIG. 19, the aerodynamic sound reducing unit 23 covers the surface of the aerodynamic sound generation source of the windshield cover 19 of the current collector 3 and the surface of the aerodynamic sound generation source of the spindle cover 26 of the current collector 3. .. The aerodynamic noise reducing portion 23 is attached to the vicinity 19i of the proximity portion of the windshield cover 19 shown in FIG. 19 and the lower ridge angle portion 26e and the upper ridge angle portion 26f of the spindle cover 26 shown in FIGS. 19 and 20.

The protective portion 24 shown in FIGS. 19 and 20 is formed in a shape along the surfaces of the windshield cover 19 and the spindle cover 26, and is mounted on the surfaces of the windshield cover 19 and the spindle cover 26. As shown in FIG. 12, the protective portion 24 has an adhesive on the surfaces of the windshield cover 19 and the spindle cover 26 so that the surfaces of the windshield cover 19 and the spindle cover 26 and the surface of the protective portion 24 are at the same height. It is glued by such as.

The fixing portion 25 shown in FIGS. 12 and 20 detachably fixes the protective portion 24 to the windshield cover 19 and the spindle cover 26 so as to sandwich the aerodynamic noise reducing portion 23 between the protective portion 24 and the accommodating portion 22. .. As shown in FIG. 20, the fixing portion 25 is inserted into the through holes formed at the four corners of the aerodynamic noise reducing portion 23 and the protective portion 24, and the aerodynamic noise reducing portion 23 and the protection are provided on the windshield cover 19 and the spindle cover 26. The part 24 is fixed.

The aerodynamic noise reduction structure of the current collector according to the fifth embodiment of the present invention has the following effects in addition to the first to fourth embodiments.
In the fifth embodiment, the aerodynamic sound reducing unit 23 covers the surface of the aerodynamic sound generating source of the spindle cover 26 of the current collector 3. Therefore, the aerodynamic sound generated from the lower ridge angle portion 26e and the upper ridge angle portion 26f, which are the sources of the aerodynamic sound of the spindle cover 26, can be reduced. Further, the aerodynamic sound generated by the interference flow between the windshield cover 19 and the spindle cover 26 can be alleviated by the aerodynamic sound reducing unit 23 around the proximity portion 19i.

Next, examples of the present invention will be described.
(Wind tunnel test)
As shown in FIG. 22, a porous material is attached to the apex cover of a real Shinkansen pantograph having a smoothing boat body having a large number of through holes, a punching metal covering the porous material is attached, and aerodynamics is performed by a wind tunnel test. The sound was evaluated. For the wind tunnel test, an open-body wind tunnel test device of the Railway Technical Research Institute was used. A recess was formed in the apex cover of the boat support portion of the actual Shinkansen pantograph, a porous material was attached to the recess, and the surface of the porous material was covered with a punching metal having a circular through hole. As shown in FIG. 22, a part of the surface of the porous material is not covered with the punching metal. As shown in FIG. 21, with the actual Shinkansen pantograph supported on the support carriage of the wind tunnel measurement section of the wind tunnel test device, air at a wind speed of 360 km / h is blown out from the blow nozzle to the Shinkansen pantograph in the wind tunnel measurement section. The aerodynamic sound generated from the Shinkansen pantograph due to the air flow was measured with a microphone.

(Sample)
Table 1 shows the types of specimens A to I used in the aerodynamic sound reduction effect test. Table 2 shows the opening conditions of the holes of the punching metal of the specimens C to H used in the aerodynamic sound reduction effect test.

As the porous material shown in Table 1, a product (product number MF-13) having a trade name of malt filter (urethane resin) manufactured by Inoac Corporation, a thickness of 5 mm, and a cell range of 11 or more and 16 or less was used. As shown in FIG. 23 (A), the punching metal was manufactured by punching holes in an aluminum plate under predetermined opening conditions. “Pitch P” shown in Table 2 is the length between the centers of adjacent through holes 24a as shown in FIG. 23 (A), and “bone B” is the distance between the edges of the adjacent through holes 24a. , "Aperture ratio" is the ratio of through holes to one plate. The “vertical type” shown in Table 2 is a case where the through holes 24a are arranged so that the center line L of the through holes 24a as shown in FIG. 23 (B) coincides with the direction of the flow F. The "horizontal type" is a case where the through holes 24a are arranged so that the center lines L of the plurality of through holes 24a as shown in FIG. 23C are orthogonal to the direction of the flow F.

(Measurement result of aerodynamic sound)
FIG. 24 shows the measurement results of the aerodynamic sounds of the specimens A to I by the wind tunnel test. The vertical axis shown in FIG. 24 is the noise level POA value (dB (A)). The measurement result of aerodynamic sound was evaluated by the partial overall value in the frequency band up to 8 kHz. Specimen A shown in FIG. 24 is a measurement result when there is no porous material. Specimen B is a measurement result when the porous material is completely covered with a plate having no through holes. The specimen B has a structure in which the through holes of the punching metal are closed with aluminum tape. Specimens C to H are measurement results under the opening conditions of the holes of each punching metal shown in Table 1. Specimen I is a measurement result in the case of only a porous material not covered with a plate.

As shown in FIG. 24, as an overall tendency, the specimens C to I have a higher noise reduction effect than the specimens A and B, and when the porous material is covered with the punching metal, only the porous material is used. It was confirmed that the noise level was almost the same as the case. As a result, it was confirmed that even when the porous material was covered with the punching metal, the aerodynamic noise reduction effect of the porous material was not impaired.

Regarding the arrangement of the holes in the punching metal, comparing the specimens C1 and C2 with the specimen D, the vertical type shown in FIG. 23 (B) has a more aerodynamic sound reduction effect than the horizontal type shown in FIG. 23 (C). Was confirmed to be large. Therefore, it is better to arrange the vertically arranged through holes 24a as shown in FIGS. 13 (A) and 13 (B) along the ridge angle portion, so that the horizontally arranged through holes 24a as shown in FIG. 13 (C) are arranged at the ridge angle portion. It was confirmed that the aerodynamic sound reduction effect was superior to the arrangement along the line.

Regarding the aperture ratio, there was no clear tendency from the experimental results, but a sufficient aerodynamic noise reduction effect was confirmed even when the aperture ratio was 33%. As a result, it is estimated from the experimental results that a sufficient aerodynamic sound reduction effect can be obtained within the range of the aperture ratio of 30% or more and 60% or less.

Regarding the plate thickness of the punching metal, when the specimens E1, E2, F1 and F2 were compared, it was confirmed that the plate thickness t1.0 mm had a higher noise level than the plate thickness t0.5 mm. Further, it was confirmed that the noise levels of the specimens C1 and C2 were substantially the same for both the plate thickness t1.0 mm and the plate thickness t0.5 mm. Therefore, it was confirmed that the thinner the punching metal, the smaller the effect on the aerodynamic sound.

Regarding the hole diameter of the punching metal, it was confirmed that the noise level was reduced within the range of 3 mm or more and 8 mm or less, which is within the range of the hole diameters of the specimens C to H. In particular, it was confirmed that the noise level was reduced in the case of the specimens F1, F2, and H. In this wind tunnel test, it was confirmed that the specimen H having a hole diameter of 3 mm has the least influence on the aerodynamic noise and can reduce the aerodynamic noise the most.

Table 3 shows the calculation results of the ratio of the bending strength of each specimen C to H. Specimen 0 shown in Table 3 is a steel plate having no through holes and a plate thickness of 0.5 mm. The “bending strength ratio” shown in Table 3 is a value obtained by normalizing the bending strength of each of the specimens C to H when the bending strength of the specimen 0 is 1. "Ligament efficiency" is a value obtained by dividing the bone width by the pore size. As for the strength of the punching metal, as shown in Table 3, the strength generally increases as the plate thickness increases, but as shown in FIG. 24, the aerodynamic sound tends to increase as the plate thickness increases. Further, as shown in Table 3, those having a low aperture ratio such as specimens G and H have high ligament efficiency and a high bending strength ratio. As a result, as shown in Table 3, it was generally confirmed that the higher the ligament efficiency, the higher the strength, and the smaller the pore diameter, the more advantageous in terms of strength. As shown in Table 3, it was confirmed that the punching metal of the specimens C2, E2, and F2 having a plate thickness of 1.0 mm had substantially the same strength as the steel plate having no holes in the specimen 0 and having a plate thickness of 0.5 mm. .. As shown in FIG. 24, in conducting this wind tunnel test, it was confirmed that the specimen H was the optimum punching medal in terms of both the aerodynamic sound reduction effect and the strength.

(Other embodiments)
The present invention is not limited to the embodiments described above, and various modifications or modifications can be made as described below, and these are also within the scope of the present invention.
(1) In this embodiment, a single-arm pantograph has been described as an example of the current collector 3, but the present invention can also be applied to other types of pantographs such as a diamond-shaped pantograph. Further, in this embodiment, the case of reducing the aerodynamic sound generated from the aerodynamic sound source of the aerodynamic sound source of the aerodynamic sound source of the aerodynamic sound source of the apex cover 8, the intermediate hinge 13, the windshield cover 19 and the spindle cover 26 of the current collector 3 has been described as an example. The present invention is not limited to these aerodynamic sound sources. For example, the present invention can be applied to the case of reducing the aerodynamic sound generated from other aerodynamic sound sources such as the horn 4a and the insulator 20. Further, in this embodiment, the case where the porous material is applied to the current collector 3 to reduce the aerodynamic sound has been described as an example, but the aerodynamic sound is produced by applying the porous material to the current collector 3 other than the current collector 3. The present invention can also be applied to the case of reduction.

(2) In this embodiment, the case where the aerodynamic sound reducing unit 23 is a porous material having continuous pores has been described as an example, but the case where the aerodynamic sound reducing unit 23 is a mesh-like porous material is also described. The invention can be applied. Further, in this embodiment, the case where the through hole 24a of the protective portion 24 has a circular shape or a slit shape has been described as an example, but the present invention also applies to a case where the protective portion 24 has a circular shape, a hexagonal shape, an elliptical shape, or the like. Can be applied.

(3) In this embodiment, the case where the aerodynamic sound reduction unit 23 is covered with the protection unit 24 having the through hole 24a having the same depth as the thickness of the protection unit 24 has been described as an example, but the aerodynamic sound reduction unit 23 has been described. The present invention can also be applied to a case where the periphery of the through hole 24a of the protective portion 24 is raised on the side in contact with the protective portion 24 to form a protrusion (burring). In this case, the strength of the protective portion 24 can be improved by the protrusions around the through hole 24a. Further, in the first to third embodiments and the fifth embodiment, the case where the current collector 3 moves in the fluttering direction in which the intermediate hinge 13 is located on the front side in the traveling direction of the vehicle 2 has been described as an example. However, the present invention can also be applied to the case where the current collector 3 moves in the anti-fluttering direction in which the intermediate hinge 13 is located on the rear side in the traveling direction of the vehicle 2.

1 Overhead line 1a Tram line 2 Vehicle 2a Body 3 Current collector 4 Boat body 5 Slip plate 6 Frame 7 Boat support 8 Top cover 8A Top cover 8B Bottom cover 8d Upper ridge angle (aerodynamic sound source)
8e Lower ridge angle (aerodynamic sound source)
9 Upper frame 11 Lower frame 13 Intermediate hinge 14 Intermediate hinge cover 14e, 14f Upper ridge angle (aerodynamic sound source)
14g Lower ridge angle (aerodynamic sound source)
15 Main shaft 18 Underframe 19 Windshield cover 19f Upper ridge angle (aerodynamic sound source)
19g Lower ridge angle (aerodynamic sound source)
19h Around the joint (aerodynamic sound source)
19i Proximity area (aerodynamic sound source)
20 Insulators 21A-21D Aerodynamic noise reduction structure 22 Accommodating unit 23 Aerodynamic noise reduction unit 24 Protective unit 24a Through hole 25 Fixed unit 26 Main shaft cover 26e Lower ridge angle (aerodynamic sound source)
26f Upper ridge angle (aerodynamic sound source)
F Flow D ₁ , D ₂ Direction of travel L Center line

Claims (9)

It is an aerodynamic sound reduction structure of the current collector that reduces the aerodynamic sound generated from the aerodynamic sound source of the current collector.
An aerodynamic sound reduction unit that covers the surface of the aerodynamic sound generation source to reduce the aerodynamic sound,
A protective portion that has a plurality of through holes through which a flow flows in and out of the aerodynamic noise reducing portion, covers the surface of the aerodynamic noise reducing portion, and protects the aerodynamic noise reducing portion.
Aerodynamic noise reduction structure of the current collector equipped with. In the aerodynamic sound reduction structure of the current collector according to claim 1,
The aerodynamic sound reducing unit covers the surface of the aerodynamic sound source of the apex cover of the current collector.
The aerodynamic noise reduction structure of the current collector, which is characterized by. In the aerodynamic sound reduction structure of the current collector according to claim 1,
The aerodynamic sound reducing unit covers the surface of the aerodynamic sound source of the intermediate hinge cover of the current collector.
The aerodynamic noise reduction structure of the current collector, which is characterized by. In the aerodynamic sound reduction structure of the current collector according to claim 1,
The aerodynamic sound reducing unit covers the surface of the aerodynamic sound generation source of the windshield cover of the current collector.
The aerodynamic noise reduction structure of the current collector, which is characterized by. In the aerodynamic sound reduction structure of the current collector according to claim 1,
The aerodynamic sound reducing unit covers the surface of the aerodynamic sound generation source of the spindle cover of the current collector.
The aerodynamic noise reduction structure of the current collector, which is characterized by. In the aerodynamic sound reduction structure of the current collector according to any one of claims 1 to 5.
In the protective portion, the opening ratio of the through hole is 30% or more and 60% or less.
The aerodynamic noise reduction structure of the current collector, which is characterized by. In the aerodynamic sound reduction structure of the current collector according to any one of claims 1 to 5.
The protective portion has an inner diameter of 3.0 mm or more and 8.0 mm or less of the through hole.
The aerodynamic noise reduction structure of the current collector, which is characterized by. In the aerodynamic sound reduction structure of the current collector according to any one of claims 1 to 7.
The aerodynamic noise reduction is that the material is a porous metal material.
The aerodynamic noise reduction structure of the current collector, which is characterized by. In the aerodynamic sound reduction structure of the current collector according to any one of claims 1 to 8.
In the protective portion, the plurality of through holes are arranged so that the center lines of the plurality of through holes coincide with the direction of the flow.
The aerodynamic noise reduction structure of the current collector, which is characterized by.

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