JP2021142944A - Forefront part structure of movable body - Google Patents

Abstract

To provide a forefront part structure of a movable body capable of exhibiting a reduction effect of a micro atmospheric pressure wave even if there is a step part in a forefront part of the movable body.SOLUTION: A forefront part structure 7 has a structure having micro atmospheric pressure wave reduction performance which can reduce a micro atmospheric pressure wave that is generated when a vehicle 2 having a step part 5C in a forefront part 5A plunges into a tunnel. A forefront part shape S has at least three peaks P1 to P3 in a cross sectional area rate-of-change distribution dA*/dX of the forefront part 5A of the vehicle 2, and the step part 5C is present in the peaks P1 to P3. The forefront part shape S has the peaks P1 to P3 of the cross sectional area rate-of-change distribution dA*/dX at a forefront part tip 5a, a forefront part intermediate part 5b and a forefront part rear end 5c of the forefront part 5A of the vehicle 2, and the step part 5C is present between the peak P1 of the forefront part tip 5a and the peak P2 of the forefront part intermediate part 5b. The step part 5C is formed in the forefront part 5A when the forefront part 5A is drawn.SELECTED DRAWING: Figure 5

Description

The present invention relates to a head portion structure of a moving body having a micro-pressure wave reducing performance capable of reducing a micro-pressure wave generated when a moving body having a stepped portion at the head portion rushes into a tunnel.

One of the problems of the aerodynamic environment along the high-speed railway is the micro-pressure wave radiated from the tunnel entrance. When a train rushes into a tunnel at high speed, a compressed wave is generated in the tunnel. This compressed wave propagates in the tunnel at the speed of sound and is end-reflected at the exit. The pulsed pressure wave radiated outside the tunnel during this reflection is called a tunnel micro-pressure wave or simply a micro-pressure wave. Micro-pressure waves cause blasting noise, vibration and rattling of houses, and noise, so it is necessary to take measures. The micropressure wave is almost proportional to the maximum value of the wavefront pressure gradient (time change rate of the compressed wave) of the compressed wave arriving at the tunnel exit. In order to reduce the micro-pressure wave, it is necessary to reduce the maximum value of the wave surface pressure gradient of the compressed wave, and it is effective to take measures to lengthen the formation time of the compressed wave and smooth the pressure gradient. One of the conventional methods for reducing micro-pressure waves by the train head is to extend the streamlined train head and optimize the shape.

However, the extension of the front part of the vehicle is subject to design restrictions other than aerodynamics. For this reason, due to design restrictions other than aerodynamics, if there is a discontinuous part in the cross-sectional area at the head part, the flow will separate there, and the vehicle cross-sectional area will apparently become large, and the head part will be fine. The performance of pressure wave reduction is reduced. Moreover, even if the leading portion is desired to be extended, the space that can be used for the audience seats is reduced accordingly. In order to secure a space that can be used for the audience seats, a variable-shaped head portion that extends the head portion only when driving at high speed can be considered.

The conceivable variable shape head portion is composed of a rear side portion including the driver's cab and a front side portion located on the front side of the rear side portion, and the front side portion is moved in the front-rear direction of the vehicle body by the rear side portion. It is supported so as to be relatively movable, and a storage space portion for storing the front side portion is formed inside the rear side portion (see, for example, Patent Document 1). In the high-speed running state, the front side portion of the vehicle body is in the reference position, and in the low-speed traveling state, the front side portion is retracted to shorten the length in the front-rear direction of the vehicle body.

Japanese Unexamined Patent Publication No. 2004-161085

In the vehicle body at the head of the variable shape that can be considered, the front side portion is lengthened in the front-rear direction of the vehicle body during high-speed driving to reduce micro-pressure waves. However, if a variable shape mechanism is provided at the head portion, a discontinuous portion of the cross-sectional area also occurs there, and if the problem due to the above-mentioned flow separation occurs, it is considered that the micro-pressure wave is adversely affected. ..

An object of the present invention is to provide a head portion structure of a moving body capable of exerting a reduction effect of micropressure waves even if a step portion is present at the head portion of the moving body.

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.
As shown in FIG. 5, the invention of claim 1 is a micro-pressure wave reduction capable of reducing a micro-pressure wave generated when a moving body having a step portion (5C) at a head portion (5A) rushes into a tunnel. It is a head portion structure of a moving body having performance, and the head portion shape (S) of the moving body has at least three peaks (P) in ^{the cross-sectional area change rate distribution (dA * / dX) of the head portion of the moving body.} _{There are 1 to} P ₃ ), and the step portion is a head portion structure (7) of a moving body characterized in that it exists between the peaks.

The invention of claim 2 is the head portion structure of the moving body according to claim 1, wherein the head portion shape of the moving body is the tip portion (5a), the intermediate portion (5b), and the rear portion of the head portion of the moving body. The end portion (5c) has a peak of the cross-sectional area change rate distribution, and the step portion exists between _{the peak at the tip portion (P 1} ) and the peak at the intermediate portion (P _2). It is the head structure of the moving body.

The invention of claim 3 is the head structure of the moving body according to claim 1 or 2, and as shown in FIG. 4, the length (L ₂ ) of the step portion is 1.5 m or less. It is a head structure of a moving body, which is characterized in that.

In the invention of claim 4, in the head structure of the moving body according to claim 1 or 2, as shown in FIG. 4, the length (L ₂ ) of the step portion is 1.5 m or less, and the step portion is 1.5 m or less. , The structure of the head portion of the moving body is characterized in that _{the cross-sectional area (A 3} ) of the head portion of the portion where the step portion exists is 2.0 m ^{2 or more.}

In the invention of claim 5, in the head portion structure of the moving body according to any one of claims 1 to 4, as shown in FIGS. 1 and 2, the step portion has the head portion. It is a head portion structure of a moving body, which is characterized by being formed at the head portion when stretched.

According to the present invention, even if there is a stepped portion at the head portion of the moving body, the effect of reducing the micropressure wave can be exhibited.

It is an external view which shows typically the head part structure of the moving body which concerns on embodiment of this invention, (A) is a plan view, (B) is a side view. It is an external view which shows typically the state before and after stretching of the head part in the head part structure of the moving body which concerns on embodiment of the invention, (A) is the side view which shows the state before stretching, (B) is It is a side view which shows the state after stretching. It is a vertical cross-sectional view which shows typically the step part of the head part structure of the moving body which concerns on embodiment of this invention, (A) is a vertical cross-sectional view, and (B) is a cross-sectional view. It is a vertical cross-sectional view which shows typically the various step portions in the head part structure of the moving body which concerns on embodiment of this invention, and (A)-(E) are the vertical cross-sectional views of the head part when a step part exists. (F) is a vertical cross-sectional view of the head portion when there is no step portion. It is an external view which shows typically the head part shape of the head part structure of the moving body which concerns on embodiment of this invention, (A) is the side view, (B) is the cross-sectional area change rate distribution of the head part shape. It is a graph which shows typically as an example. It is the schematic of the model experimental apparatus used for the experiment of the micro-pressure wave reduction effect by the head part structure of the moving body which concerns on embodiment of this invention. It is a photograph of the vehicle head part model used in the experiment of the micro-pressure wave reduction effect by the head part structure of the moving body which concerns on embodiment of this invention. It is a graph of the vehicle head portion shape used in the experiment of the micro-pressure wave reduction effect by the head portion structure of the moving body according to the embodiment of the present invention. It is a graph which shows the model experiment result of the micro-pressure wave reduction effect by the head part structure of the moving body which concerns on embodiment of this invention, (A) is a graph which shows the pressure waveform of a compression wave, and (B) is a pressure gradient. It is a graph which shows the waveform. It is a graph which shows the influence of the step part by the model experiment result of the micro-pressure wave reduction effect by the head part structure of the moving body which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The track 1 shown in FIG. 1 is a passage (track) on which the vehicle 2 travels. The track 1 includes a pair of rails that support and guide the wheels of the vehicle 2. The vehicle 2 is a moving body that moves along the track 1. Vehicle 2 is, for example, a high-speed train by a railway vehicle traveling on the Shinkansen (registered trademark) at a high speed of 300 km / h or more. The vehicle 2 shown in FIG. 1 is, for example, the leading vehicle when traveling in the direction of the arrow in the figure, and the trailing vehicle when traveling in the direction opposite to the direction of the arrow. The vehicle 2 includes a bogie 3 shown in FIG. 1 (B), a vehicle body 4 shown in FIGS. 1 (A) and 1 (B), a drive device 6, and the like. The bogie 3 shown in FIG. 1B is a device that supports the vehicle body 4 and travels on the track 1. The carriage 3 includes wheels that roll along the rails of the track 1. The vehicle body 4 shown in FIGS. 1A and 1B is a part for transporting a load such as a crew member and a passenger. The vehicle body 4 includes a front portion 5A shown in FIG. 1, a tail portion 5B, a step portion 5C shown in FIGS. 1 to 3, and the like. In the vehicle body 4, the crew room on which the crew operating the master controller for driving and controlling the vehicle 2 rides is arranged on the front portion 5A side, and the passenger cabin on which the passengers ride is arranged on the tail portion 5B side. ..

The leading portion 5A shown in FIG. 1 is a portion constituting the front portion side of the vehicle 2. The head portion 5A is formed in a long streamline to reduce air resistance and micro-pressure waves. The head portion 5A includes a head portion tip 5a forming the front portion of the head portion 5A, a head portion middle 5b forming an intermediate portion between the head portion tip 5a and the head portion rear end 5c, and the head portion intermediate 5b. It is provided with a front end rear end 5c constituting the rear portion of the 5A, an extension portion 5d for extending _{the length L n of the front portion 5A, and the like.} As shown in FIG. 2, the head portion 5A has a split structure that can be divided into a movable portion on the tip end 5a side of the head portion and a fixed portion on the middle 5b side of the head portion. As shown in FIG. 2 (A), when the length L _n of the head portion 5A is shortened, the extension portion 5d is housed in the vehicle body 4 and is shown in FIG. 2 (B). _{When the length L n} of the leading portion 5A is extended as described above, the extended portion 5d is exposed to the outside of the vehicle body 4.

The tail portion 5B shown in FIG. 1 is a portion constituting the rear side of the vehicle 2. The tail portion 5B has a substantially constant cross-sectional area when cut on a vertical plane orthogonal to the center line of the vehicle 2. The tail portion 5B includes a tail portion tip 5e that connects to the front end rear end 5c, a tail portion rear end 5f that is an end opposite to the tail portion tip 5e, and the like. The tail portion 5B is provided with a connecting device or the like for connecting other vehicles formed as an intermediate vehicle during formation at the rear end portion 5f of the tail portion.

The stepped portion 5C shown in FIGS. 1 to 3 is a stepped portion formed on the leading portion 5A. As shown in FIG. 1, the step portion 5C is formed on the leading portion 5A when _{the length L n of the leading portion 5A is extended.} As shown in FIG. 3, the step portion 5C includes wall portions 5g, 5h, upper edge portions 5i, 5j, lower edge portions 5k, 5m, a bottom portion 5n, and the like. The wall portions 5g and 5h are flat surfaces orthogonal to the center line of the vehicle 2. The wall portion 5g is formed closer to the leading end 5a of the leading portion, and the wall portion 5h is formed closer to the rear end 5c of the leading portion facing the wall portion 5g. The wall portions 5g and 5h are cross-sectional area discontinuous portions of the leading portion 5A. Here, the cross-sectional area discontinuous portion is a portion where the cross-sectional area of the vehicle 2 changes vertically when cut on a vertical plane passing through the center line of the vehicle 2. The upper edge portions 5i and 5j are corner portions where the wall portions 5g and 5h and the surface of the head portion 5A intersect. The lower edge portions 5k and 5m are corner portions where the wall portions 5g and 5h and the bottom portion 5n intersect. The bottom portion 5n is a portion constituting the bottom surface of the step portion 5C. The step portion 5C has various forms depending on the structure of the stretched portion 5d as shown in FIGS. 4 (A) to 4 (E), with the head portion shape S shown in FIG. 4 (F) as the basic shape.

The stepped portion 5C shown in FIGS. 4A and 4B has a length (variable portion length (discontinuous portion length)) L ₁ , L _{2 in the front-rear direction of the vehicle 2 so as to cut out the surface of the leading portion 5A.} It is formed in a substantially L shape at (L ₁ <L _2). In the stepped portion 5C shown in FIGS. 4A and 4B, the upper edge portion 5j and the bottom portion 5n are smoothly connected to the surface of the leading portion 5A. The step portion 5C shown in FIG. 4 (B) has a higher step portion height than the step portion 5C shown in FIG. 4 (A), and the length L ₂ of the step portion 5C shown in FIG. 4 (B) is FIG. It is formed so as to be longer toward the tip 5a of the leading portion than _{the length L 1} of the step portion 5C shown in (A).

The stepped portions 5C shown in FIGS. 4 (C) to 4 (E) have a length L _{2 in the front-rear direction of the vehicle 2 and a depth D 1} to D in the vertical direction of the vehicle 2 so as to cut out the surface of the leading portion 5A. It is formed in a substantially U shape with ₃ (D ₁ <D ₂ <D _3). In the stepped portion 5C shown in FIGS. 4 (C) to 4 (E), the upper edge portions 5i and 5j are smoothly placed on the surface of the leading portion 5A so that the height of the upper edge portion 5i is lower than that of the upper edge portion 5j. It is connected. When the stepped portion 5C shown in FIGS. 4 (C) to 4 (E) is cut on a vertical surface passing through the center line of the vehicle 2, the leading portion 5A of the portion (constricted portion) where the stepped portion 5C exists is cut off. Area (cross-sectional area of constriction) A _{1 to} A ₃ (A ₁ > A ₂ > A ₃ ).

As shown in FIG. 5, the step portion 5C exists between the peaks P ₁ and P ₂ ^{of the cross-sectional area change rate distribution dA * / dX of the leading portion 5A of the vehicle 2.} The step portion 5C exists _{, for example, between the peak P 1} at the tip 5a of the head portion and the peak P _{2 at the middle 5b of the head portion. The step portion 5C preferably has a length L 2} of the step portion 5C shown in FIG. 4 of 1.5 m or less. It is preferable that the step portion 5C has a length L ₂ of the step portion 5C of 1.5 m or less and a cross-sectional area A ₃ of the head portion 5A of 2.0 m ² or more.

The driving device 6 shown in FIGS. 1 and 2 is a device for driving the stretched portion 5d. The drive device 6 functions as a shape variable mechanism unit that changes the shape of the head portion 5A. _{The driving device 6 changes the length L n} of the leading portion 5A by driving the extending portion 5d of the leading portion 5A. The drive device 6 reciprocates, for example, a rack that meshes with a pinion that is rotated by an electric motor, and moves the extension portion 5d connected to the rack back and forth by a rack / pinion mechanism, a fluid pressure of a working fluid such as hydraulic pressure or pneumatic pressure. It is a hydraulic cylinder device or a pneumatic cylinder device that moves the stretched portion 5d forward and backward. As shown in FIG. 2B, the drive device 6 advances the extension portion 5d so that _{the length L n} of the head portion 5A extends when the vehicle 2 travels on the main line at high speed to generate a micro-pressure wave. Reduce. On the other hand, as shown in FIG. 2A, the drive device 6 has a length L of a leading portion 5A so as not to interfere with the structure in the depot when the vehicle 2 travels in the depot or the like at a low speed. _The stretched portion 5d is retracted so that n is shortened.

The head structure 7 shown in FIGS. 1 to 5 is a structure having a micro-pressure wave reduction performance capable of reducing a micro-pressure wave generated when a vehicle 2 having a step portion 5C rushes into a tunnel. The top portion structure 7, as shown in FIG. 5 (B), the head portion shape S on the assumption that the sectional area change rate dA / dX has a plurality of peaks P ₁ to P ₃ are optimized. As shown in FIG. 3, the head portion structure 7 has a smooth head portion shape S as shown in FIG. 5 (A) so that the flow F around the head portion 5A does not largely separate at the sudden change portion of the cross-sectional area. Is formed in. The head structure 7 is formed in a head shape S in which the rear end 5c of the head is smoothly connected to the tip 5e of the tail so that the flow F around the head 5A does not separate significantly at the rear end 5c of the head. ing.

The head portion shape S shown in FIGS. 4 and 5 is a cross-sectional shape when cut on a vertical plane passing through the center line of the vehicle 2. The head portion shape S shown in FIG. 5 (A) is a combination of a predetermined number (for example, 10) of error functions and a weight function indicating that the front end rear end 5c is smoothly connected to the tail tip 5e. sectional area change rate dA / dX represent cross-sectional area change rate dA / dX of magnitude of the peak P ₁ to P _3, it is optimized position and spread as the optimum parameter by. The head portion shape S has at least three peaks P _{1 to} P _{3 in} the cross-sectional area change rate distribution dA ^* / dX of the head portion 5A of the vehicle 2. The head portion shape S is a smooth shape in which the cross-sectional area change rate dA / dX is represented by a combination of error functions. Here, the cross-sectional area change rate dA / dX is the rate at which the cross-sectional area when cut on a vertical plane orthogonal to the center line of the vehicle 2 changes from the front end 5a to the tail rear end 5f. be. The cross-sectional area change rate distribution dA ^* / dX shown in FIG. 5 is given based on 10 error functions, and is optimized with the size, position, and spread of each basis as parameters.

_{As shown in FIG. 5A, the head portion shape S has peaks P 1 to} P ₃ ^{of cross-sectional area change rate distribution dA *} / dX at the head portion tip 5a, the head portion middle 5b, and the head portion rear end 5c. .. _{When the length L n} of the head portion 5A is less than 20 m, the head portion shape S has _{three peaks P 1} to ^{3 peaks P 1 to the cross-sectional area change rate distribution dA *} / dX of the head portion 5A as shown in FIG. 5 (B). There is P _3. The head portion shape S is a shape that increases the cross-sectional area by about 1/3 at the head portion tip 5a, the head portion middle 5b, and the head portion rear end 5c. _{The head portion shape S has large single peaks P 1} and P ₃ immediately before the front end portion 5a and the head portion rear end 5c, and the cross-sectional area change rate dA / dX is small and wide peak P _{2 in the front portion middle 5b.} It is an abbreviated W-shape with. The head portion shape S has a cross-sectional area change rate at the front end rear end 5c in order to suppress peeling of the flow F at the connection portion between the tail portion tip 5e and the front end rear end 5c where the cross-sectional area of the vehicle body 4 becomes constant. The distribution dA ^* / dX is zero.

The head structure of the moving body according to the embodiment of the present invention has the effects described below.
(1) In this embodiment, there are at least three peaks P ₁ to P ₃ to the cross-sectional area change rate distribution dA ^* / dX of the leading portion 5A of the vehicle 2, the step portion 5C is present between the peak P ₁ to P ₃ do. Therefore, by providing the stepped portion 5C at an appropriate position of the leading portion 5A, it is possible to avoid adversely affecting the effect of reducing the micro-pressure wave.

(2) In this embodiment, there is the top tip 5a, the top portion intermediate 5b and the top cross-sectional area change rate in the rear end 5c distribution dA ^* / dX of the peak P ₁ to P ₃ of the head portion 5A of the vehicle 2, There is a stepped portion 5C between _{the peak P 1} at the tip 5a of the head portion and the peak P _{2 at the middle 5b of the head portion.} Therefore, when the shape S of the head portion of the train is optimized, the effect of reducing the micro-pressure wave is adversely affected by providing the position of the cross-sectional area discontinuous portion of the head portion 5A at an appropriate position. Can be avoided.

(2) In this embodiment, the length L ₂ of the step portion 5C is 1.5 m or less. Further, in this embodiment, the length L _{2 of the step portion 5C is 1.5 m or less, and the cross-sectional area A 3} of the leading portion 5A of the portion where the step portion 5C exists is 2.0 m ² or more. At this time, the flow F peeled off near the upper edge portion 5i of the step portion 5C can be reattached on the downstream side of the upper edge portion 5j of the step portion 5C.

(4) In this embodiment, when the head portion 5A is stretched, a step portion 5C is formed on the head portion 5A. Therefore, when the vehicle 2 is provided with a variable mechanism for changing the shape of the leading portion 5A, the stepped portion 5C formed on the leading portion 5A when the leading portion 5A is extended has an effect of reducing micro-pressure waves. It is possible to avoid adverse effects. Further, even if the cross-sectional area discontinuity is formed by the variable mechanism that changes the shape of the head portion 5A, it is possible to exert the micro-pressure wave reduction effect almost the same as that of the streamlined head portion, and the head portion shape S. It is possible to solve the problem of design restrictions and the problem of shrinking the cabin space due to the extension of the leading part.

Next, examples of the present invention will be described.
(Model experiment)
In order to investigate the micro-pressure wave reduction performance by the vehicle head model shown in FIGS. 7 and 8, the tunnel micro-pressure wave model experimental device of the Railway Technical Research Institute shown in FIG. The model was driven in, and the waveform of the compressed wave in the tunnel was measured by two pressure gauges installed at a position 1 m from the tunnel entrance. In order to measure the speed of the vehicle model, coils were installed at a distance of 4 m. The pressure gradient waveform was obtained by the center difference.

The scale of the model experiment was set to 1/127 in consideration of the mirror image of ^{the 63.4 m 2 Shinkansen tunnel.} A pipe with an inner diameter of 100 mm was used for the tunnel model. The vehicle model has a vehicle / tunnel cross-sectional area ratio (blockage ratio) of 0.19, a head part equivalent to a real scale length of 12 m, a spheroid shape at the head part, and an eccentric running equivalent to a Shinkansen train with respect to the center of the shock absorber model. The model entry speed was mainly 360km / h.

Six types of vehicle front model, Comparative Example 1 and Examples 1 to 5 shown in FIGS. 7 and 8, were produced. The graph shown in FIG. 8 shows the actual scale cross-sectional area distribution of the vehicle head model, the vertical axis is the cross-sectional area A (m ₂ ) when cut on a vertical plane passing through the center line of the vehicle, and the horizontal axis. Is the distance X (m) from the tip of the front part of the vehicle. The first embodiment is a vehicle leading portion model corresponding to the step portion 5C shown in FIG. 4A, and has a variable portion length of 1.0 m. The second embodiment is a vehicle leading portion model corresponding to the step portion 5C shown in FIG. 4B, and has a variable portion length of 1.5 m. The third embodiment is a vehicle leading portion model corresponding to the step portion 5C shown in FIG. 4C, has a variable portion length of 1.5 m, and a constricted portion cross-sectional area of 4 m ² . The fourth embodiment is a vehicle leading portion model corresponding to the step portion 5C shown in FIG. 4D, has a variable portion length of 1.5 m, and a constricted portion cross-sectional area of 3 m ² . The fifth embodiment is a vehicle leading portion model corresponding to the step portion 5C shown in FIG. 4 (E), has a variable portion length of 1.5 m, and a constricted portion cross-sectional area of 2 m ² . Comparative Example 1 is a vehicle head model in which the head shape S as shown in FIG. 4 (F) is the reference shape and there is no step portion 5C.

(Experimental result)
The vertical axis shown in FIG. 9 (A) is the pressure (kPa), the vertical axis shown in FIG. 9 (B) is the pressure gradient (MPa / s), and the horizontal axis shown in FIGS. 9 (A) and 9 (B). Is the time (ms). Here, the pressure gradient waveform is a time derivative waveform of the compression wave generated in the tunnel model when the vehicle model rushes into the tunnel model. As shown in FIG. 9 (A), the waveform of the compressed wave in the tunnel was measured for the vehicle head model of Comparative Example 1 and Examples 1 to 5, and as shown in FIG. 9 (B), Comparative Example 1 and Example The pressure gradient waveforms were calculated for the vehicle head models 1 to 5.

The vertical axis shown in FIG. 10 is the ratio of the maximum pressure gradient values, and the horizontal axis is the area of the step portion. The ratio of the maximum pressure gradient values is a value obtained by dividing the maximum value of the pressure gradient waveforms of Examples 1 to 5 by the maximum value of the pressure gradient waveform of Comparative Example 1. As shown in FIG. 10, the ratio of the maximum pressure gradient values of Examples 1 to 5 is almost the same as the ratio of the maximum pressure gradient values of Comparative Example 1, and the movable portion length is 1.5 m or less, or the step portion. It was confirmed that when the length of the movable part is 1.5 m or less and the cross-sectional area of the constricted part is 2.0 m ² or more, the micro-pressure wave can be reduced even if there is a stepped part.

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, the case where the moving body is a railroad vehicle has been described as an example, but the present invention is also applied to a moving body such as a magnetic levitation type railroad, an automobile, an aircraft, or a flying object that travels at high speed. Can be applied. Further, in this embodiment, the case where the vehicle 2 is a Shinkansen train has been described as an example, but a conventional line train traveling on a conventional line or a new existing train capable of mutually traveling between a Shinkansen and a conventional line. The present invention can also be applied to trains for direct operation and the like. Further, in this embodiment, the case where the step portion 5C is formed at the position corresponding to the stretched portion 5d of the head portion 5A has been described as an example, but the step portion 5A other than the position corresponding to the stretched portion 5d has been described as an example. The present invention can also be applied to the case where a portion is formed.

(2) In this embodiment, _{the case where the length L n} of the head portion 5A is stretched by one stretching portion 5d has been described as an example, but the length L _n of the head portion 5A is multi-staged by a plurality of stretching portions. The present invention can also be applied to the case of stretching with. Further, in this embodiment, although the case of arranging the stepped portion 5C has been described as an example between the peak P _1, P ₂ of the sectional area change rate distribution dA ^* / dX, stepped between the peak P _2, P ₃ The present invention can also be applied to the case where the part 5C is arranged. Further, in this embodiment, the case where the drive device 6 is a rack / pinion mechanism, a hydraulic cylinder device, or a pneumatic cylinder device has been described as an example, but the present invention is also applied to a feed screw mechanism, a linear motor, and the like. be able to.

(3) In this embodiment, than the peak P ₁ of the cross-sectional area change rate distribution dA ^* / dX at the head tip 5a of the vehicle 2, the cross-sectional area change rate distribution in the top portion rear end 5c of the vehicle 2 dA ^* / dX The case where the peak P ₃ of is smaller is described as an example, but the present invention is not limited to this. For example, the cross-sectional area change rate at the top tip 5a and / or the top portion intermediate 5b of the vehicle 2 Distribution dA ^* / peak of dX P _1, than P _2, the cross-sectional area change rate distribution in the top portion rear end 5c of the vehicle 2 The present invention can also be applied to the case where the peak P ₃ ^{of dA * / dX is made smaller.} _{Further, in this embodiment, the case where the length L n} of the leading portion 5A of the vehicle 2 is less than 20 m has been described as an example, but the case where the length L _n of the leading portion 5A is 20 m or more is also described. The present invention can be applied. In this case, when there are four peaks P _{1 to} P _{4 in} the cross-sectional area change rate distribution dA ^* / dX of the head portion 5A, the step portion 5C can be arranged between _{the peak P 1} and the peak P _2. ..

1 track 2 vehicle (moving body)
3 Bogie 4 Body 5A Leading part 5B Rear tail 5C Step 5a Leading tip 5b Leading middle 5c Leading rear end 5d Extension 5e Rear tail tip 5f Rear tail rear end 5g, 5h Wall 5i, 5j Upper edge 5k , 5m Lower edge 5n Bottom 6 Drive device 7 Head structure dA / dX Cross-sectional area change rate dA ^* / dX Cross-sectional area change rate distribution S _{Head shape P 1 to} P ₃ Peak L _n Length (head length) )
L ₁ , L ₂ length (variable part length (discontinuous part length))
D _{1 to} D ₃ Depth A Cross-sectional area (constricted cross-sectional area)
F flow

Claims (5)

It is a head structure of a moving body having a micro-pressure wave reduction performance capable of reducing micro-pressure waves generated when a moving body having a stepped portion at the head rushes into a tunnel.
The shape of the head portion of the moving body has at least three peaks in the cross-sectional area change rate distribution of the head portion of the moving body.
The step portion exists between the peaks,
The head structure of the moving body, which is characterized by. In the head structure of the moving body according to claim 1,
The shape of the front portion of the moving body has peaks of the cross-sectional area change rate distribution at the front end portion, the middle portion, and the rear end portion of the front portion of the moving body.
The step portion exists between the peak at the tip portion and the peak at the intermediate portion.
The head structure of the moving body, which is characterized by. The head structure of the moving body according to claim 1 or 2.
The length of the step is 1.5 m or less.
The head structure of the moving body, which is characterized by. In the head structure of the moving body according to claim 1 or 2.
The length of the stepped portion is 1.5 m or less, and the cross-sectional area of the head portion of the portion where the stepped portion exists is 2.0 m ² or more.
The head structure of the moving body, which is characterized by. In the head structure of the moving body according to any one of claims 1 to 4,
The stepped portion is formed at the leading portion when the leading portion is stretched.
The head structure of the moving body, which is characterized by.

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