JP2003063386A - Top part shape of rapid-transit railway rolling stock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the top part shape of a rapid-transit railway rolling stock suitable for reduction of tunnel micro-barometric pressure waves. SOLUTION: In the top part shape 10 of the rapid-transit railway rolling stock, in the case that the top part shape is compared with pressure inclination distribution of compression waves generated by tunnel inrush of the rolling stock top part shape, a rolling stock width of an intermediate part 12 is narrower than that of a general part to be increased in a rear part 13, one peak is produced in the pressure inclination distribution by each cross sectional area change of a window part 16 and the rear part 13, the maximum values of two peaks of pressure inclination appearing in response to the window part 16, and the rear part 13 and a front end 11 respectively are substantially equal to each other, a value of a ratio of the minimum value of the pressure inclination appearing in response to the intermediate part 12 to the maximum value is not so that the two maximum values are overlapped, and a value of an intermediate section is in a prescribed range stabilized further.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head portion shape suitable for a head vehicle among railway vehicles such as Shinkansen that travel at high speed.

[0002]

2. Description of the Related Art In modern times, when high speed movement is desired, high-speed performance of 270 km / h or more per hour is required for railway vehicles. On the other hand, in Japan's railway situation where people pass through private houses,
As with speeding up, considering the environmental impact of noise and vibration is an important issue. One of the challenges of such environmental measures is the tunnel micro-pressure wave (hereinafter simply referred to as "micro-pressure wave").
There is noise at the tunnel exit. When a high-speed railway vehicle enters a tunnel, the leading vehicle acts like a piston and the air existing in a narrow space inside the tunnel is compressed to generate a compression wave. The micro-pressure wave is a partial derivative of the pressure of the compression wave with respect to time (hereinafter referred to as "pressure"), which is emitted to the outside when the compression wave propagates in the tunnel at almost the speed of sound and reaches the tunnel exit. The "gradient." The partial derivative of pressure over time is proportional to the partial derivative of pressure over space.

The micro-pressure wave radiated from such a tunnel causes noise and vibration to the building around the tunnel exit, and is therefore cited as one of environmental problems. In particular, the compression wave that causes the micro-pressure wave has a pressure gradient that increases in proportion to the cube of the vehicle speed. Therefore, in order to accelerate the speeding up of railway vehicles, the decrease of the micro-pressure wave, that is, the compression wave should be kept small. Has become an extremely important issue. Therefore, in recent years, as measures against such a problem, some proposals have been made regarding the shape of the leading portion of a high-speed railway vehicle that lowers micro-pressure waves. As an example of this, Japanese Patent Laid-Open No. Hei 11
The thing described in the Unexamined-Japanese-Patent No. 321640 can be mentioned.

The shape of the leading portion of this high-speed railway vehicle is shown in FIG.
As shown in (p) of 4, first the tip (about 6 m from the tip
(Up to the position) to form a first cross-sectional area changing region 101 by tilting backward, and after forming a region 102 in which the cross-sectional area is kept constant at the rear, tilt backward upward ( (From a position of about 21 m from the tip to a position of about 25 m), the cross-sectional area change region 103 of the second stage is formed. With such a shape, the pressure gradient of the compression wave generated when the vehicle enters the tunnel is reduced. Specifically, as shown in (P) of FIG. 15, the compression wave is largely dispersed in two stages, the maximum value of each peak is lowered, and one of the maximum values is higher than that of the comparative example (Q). You can see that it is decreasing.

Thus, FIG. 14 (p) cited in the conventional example.
The shape of the leading part shown in FIG.
Providing two 1, 103 in the front-back direction is considered to have contributed to suppressing the maximum value by setting two peaks P1 and P2 of the pressure gradient as shown in (P) of FIG. . This is because the pulse strength (power) of the micro-pressure wave is proportional to the square of such a pressure gradient. Therefore, in the shape of the leading part of the conventional example in which the maximum value of the pressure gradient is reduced,
At that point, the effect of lowering the micro-pressure wave can be seen.
On the other hand, according to the conventional example, the region 1 having a further constant cross-sectional area is provided.
02 is provided, the peak P1 of the pressure gradient distribution is
P2 is clearly divided into front and rear so that each compression wave does not become a micro-pressure wave collected at the tunnel exit.

[0006]

However, the front end shape of such a conventional example has an abnormally long front and rear dimensions. The example given in the publication is 25 m, which corresponds to the length of one vehicle. As shown in Fig. 14 (q), the current Shinkansen vehicles are
Compared to reaching the general section with the maximum cross-sectional area at a position where the rearward upward inclination from the tip is about 10 m (for example, 9.2 m for 700 series vehicles), the length is more than doubled. . The lengthening of the front part of the vehicle in this manner is not preferable from the viewpoint of securing a general part which becomes a passenger compartment. Therefore, the conventional head shape in which the peaks P1 and P2 of the pressure gradient distribution are clearly divided into front and back so that the respective compression waves do not overlap at the tunnel exit is more detrimental when applied to high-speed railway vehicles. Was great.

Further, by clearly separating the peaks P1 and P2 of the pressure gradient distribution, the minimum value of the pressure gradient corresponding to the region 102 having a constant cross-sectional area becomes extremely small, and as a result, the maximum value becomes large. Produce an effect. In other words, if the maximum cross-sectional area of the vehicle head is the same, when the tunnels with the same cross-sectional area are passed under the same conditions, the pressure change (pressure gradient distribution) that occurs during the passage time of the vehicle head even if the shape is different Area surrounded by) becomes constant. Therefore, the pressure gradient distribution has a peak P that goes back and forth.
If the depression P3 becomes deeper so as to clearly divide 1 and P2 into two, the peaks P1 and P2 parts are raised and the maximum value becomes large. Since the intensity (power) of the pulse of the micro-pressure wave is proportional to the square of such pressure gradient, the shape of the leading portion that makes the minimum value of the pressure gradient extremely small limits the decrease of the micro-pressure wave. .

Therefore, in order to solve such a problem, an object of the present invention is to provide a head portion shape of a high-speed railway vehicle which reduces micro-pressure waves under the conditions of a constant lengthwise dimension and a general section cross-sectional area. And

[0009]

The top portion of a high-speed railway vehicle according to the present invention has a front end portion which is roughly divided into a front-end portion from a tip of the high-speed railway vehicle to a general portion having a maximum cross-sectional area. A pressure wave of a compression wave generated by a tunnel entry of a vehicle front part, having a middle part and a rear part, and a driver's cab provided with a window formed at a predetermined angle on the middle part. When compared with the distribution, the front end, the rear, and the window are the areas where the cross-sectional area that produces a peak in the pressure gradient distribution has a large rate of change, and the middle area excluding the window creates a depression in the pressure gradient distribution. This is the part where the rate of change is small.The vehicle width in the middle part is made narrower than the vehicle width in the general part, and it is increased in the rear part to increase the cross-sectional area change ratio in the rear part, and each cross-sectional area change between the window and the rear part The pressure gradient distribution And the maximum values of the two peaks of the pressure gradient appearing corresponding to the window part and the rear part and the front end part are almost equal to each other, and the pressure gradient in the intermediate section appearing corresponding to the intermediate part with respect to the maximum value. It is characterized in that the value of the ratio of the local minimum values of is within a predetermined range that makes the value of the intermediate section more constant without the two local maximum values overlapping. Further, in the shape of the leading portion of the high-speed railway vehicle according to the present invention, it is desirable that the predetermined range has a ratio of the minimum value to the maximum value of 0.9 or more and 1.0 or less.

Therefore, according to the shape of the head portion of the present invention, by narrowing the vehicle width at the head portion of the vehicle, the rear portion and the window portion have a change in cross-sectional area that makes one peak in the pressure gradient distribution, and thus the head portion of the vehicle is changed. Two peaks are formed in the pressure gradient distribution of the compression wave generated by the entrance of the tunnel into the window, corresponding to the window portion having a large cross-sectional area change rate and the rear portion and the front end portion. And for the maximum value of the pressure gradient,
By setting the value of the ratio of the depressions between the peaks formed corresponding to the middle portion to the minimum value to be, for example, 0.9 or more and 1.0 or less, the two bottoms of the depressions are increased. It is possible to make the value in the intermediate section more constant without overlapping the maximum values, and to reduce the maximum value of the pressure gradient (peak maximum value). Therefore, by reducing the maximum value of the pressure gradient in this way, it becomes possible to effectively reduce the micro-pressure wave while suppressing the length dimension of the vehicle head portion.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, with reference to the drawings, an embodiment of a leading portion shape of a high-speed railway vehicle according to the present invention will be described below. FIG. 1 is a view showing a front shape of a head portion of a high-speed railway vehicle, and FIG. 2 is a view showing a side shape thereof. Further, in each of the drawings, the shapes of predetermined cross-sectional portions are shown in an overlapping manner. The leading end shape 1 is composed of a front end portion 2 having a large bulge in the vertical and horizontal directions at the tip end portion, an intermediate portion 3 which is inclined behind the front end portion 2 so that the cross-sectional area gradually increases, and further just before the general portion. It is composed of a rear part 4 which is designed to rise upwards and a large part. The length of this vehicle head is L = 9.2 m.
And maximum cross-sectional area (general section cross-sectional area) of 10.95m2
It was designed as (same as 700 series vehicle).

Next, FIG. 3 is a distribution chart showing the derivative of the cross-sectional area of the vehicle in the longitudinal direction of the vehicle body (hereinafter, referred to as "rate of change in cross-sectional area") in each pattern of the vehicle front portion having such a shape of the leading portion. is there. FIG. 4 shows the pressure gradient distribution of the compression wave (when traveling at 270 km / h) caused by the shape of the leading portion. FIG. 4 shows the pressure gradient distribution of the compression wave generated when the head of the vehicle enters the tunnel. Specifically, the pressure change of the compression wave observed at a predetermined location in the tunnel is differentiated with respect to time. It is a thing. The vertical axis shows the pressure gradient, and the horizontal axis shows the time. Here, v is the vehicle speed and L is the head length of the vehicle. And the origin 0 of the time at the observation point is
The time at which the sound wave generated at the moment the vehicle head entered the tunnel entrance reached the observation point was taken. In addition, since the observation point depends on the distance x from the tunnel entrance,
If the speed of sound is represented by s, the origin of the time is shifted by x / s in this diagram.

Therefore, from FIG. 3 and FIG.
(See FIGS. 1 and 2) shows that peaks A and B of the pressure gradient distribution are formed at the front end portion 2 and the rear portion 4 having a large cross-sectional area change rate,
It can be seen that the pressure gradient distribution forms the depression C in the intermediate portion 3 where the cross-sectional area change rate decreases. That is, in the top portion shape 1, the peaks A and B of the pressure gradient distribution due to the compression wave are dispersed by increasing the cross-sectional area change rate in the front and rear by the front end portion 2 and the rear portion 4 in this way, and the maximum value of the pressure gradient ( The maximum value of the peak) is reduced. Further, in order to disperse the peaks A and B of such a pressure gradient, the leading end shape 1 is provided with an intermediate portion 3 having a small cross-sectional area change rate, and a depression C is formed between the peaks A and B. Is.

By the way, since the micro-atmospheric pressure wave is proportional to the pressure gradient due to the compression wave, the maximum value of the pressure gradient may be lowered to lower the micro-pressure wave. That is, the peaks A and B of the pressure gradient distribution shown in FIG. 4 should be lowered. that time,
If the head of the vehicle is simply lengthened as in the conventional example, the passage time (L / v in FIG. 4) is lengthened, so that the peaks A and B can be reduced accordingly. This means that if the pressure gradient distribution has the same maximum cross-sectional area (general section cross-sectional area), the pressure change (0
This is because the area of the pressure gradient distribution surrounded by the range of to L / v) is constant, so that the longer the vehicle head, the wider the time width and the lower the pressure gradient as a whole.

However, for example, it is not realistic that one vehicle has a length of 25 m at the head portion as described above considering that one vehicle has a length of about 25 m. It becomes necessary to reduce the pressure wave. Therefore, the inventor of the present application focused on the distribution characteristic of the pressure gradient to solve such a problem. Specifically, we tried to study how to change the cross-sectional area of the head shape in order to generate a compression wave that lowers the micro-pressure wave.

First, in order to reduce the micro-pressure wave, (1)
It is necessary to suppress the peaks A and B of the pressure gradient distribution, and it is preferable that the maximum values of the peaks A and B are equally small. This is because the intensity (power) of the micro-pressure wave is proportional to the square of the pressure gradient. Further, (2) in order to make the maximum values of the peaks A and B smaller, it is preferable to bring the minimum value of the dent C portion close to the maximum value. As described above, if the area surrounded by the pressure gradient distribution between 0 and L / v is constant, reducing the depression of the depression C lowers the maximum values of peaks A and B (the maximum value of the pressure gradient). Because.

Therefore, the optimum shape of the leading portion for reducing the micro-pressure wave is as follows when compared with the pressure gradient of the compression wave generated at the time of tunnel entry by the vehicle leading portion of the shape:
It is considered that the distribution shape is close to a trapezoid, that is, the difference between the maximum value of the peaks A and B of the pressure gradient distribution and the minimum value of the depression C is small. Then, a numerical analysis was conducted from the viewpoint of the change in the cross-sectional area to find out what kind of shape the head shape shown in FIG. 1 and FIG. 2 should ideally be. Here, FIG. 5 is a diagram showing changes in the cross-sectional area corresponding to the shape of the head portion of each pattern shown in FIGS. 3 and 4.

The shape of the leading portion of each pattern showing the results of FIGS. 3 and 4 has a front end portion 2 and a rear portion 4 whose cross-sectional areas greatly change as shown in FIG. 5 (see FIGS. 1 and 2). Therefore, the cross-sectional area change rate distribution shown in FIG.
b appears remarkably. The top shape of each pattern causes the pressure gradient distribution as shown in FIG. 4 due to the difference in the cross-sectional area change rates thus shown. Therefore, in this study, based on the above (1) and (2), how are the maximum values Ax and Bx of the peaks A and B (x = 1, 2 ...
Indicates the pattern number. The same applies hereinafter) can be made equal and small, or the cross-sectional area change was extracted from the relationship of the cross-sectional area change rates ax, bx, cx. Where ax, b
x is the maximum value of the cross-sectional area change rate at the peaks a and b, and cx is the minimum value of the cross-sectional area change rate distribution in the depression c.

As a specific method for extracting the change in cross-sectional area, the ratio of ax, bx, and cx was taken, and consideration was made from the relationship between the result and the pressure gradient. In this study, an axisymmetric model was used to simplify the analysis for obtaining the optimum cross-sectional area distribution. In other words, the results of this analysis are based on the assumption that the tunnel shape is a cylindrical shape so that the cross-sectional areas are the same, and that the columnar shape is plunging so that the vehicle has the same cross-sectional area distribution. FIG. 6 is a table showing the characteristics of the cross-sectional area change rate distribution of each shape shown in FIG. Then, when the pressure gradient of the compression wave generated by the vehicle head portion shape of each of these patterns was numerically calculated, the values shown in the table of FIG. 7 were obtained.

When pattern 1 is first examined, the ratio of the maximum values Ax and Bx of the pressure gradient distribution is Ax / Bx = 1.
07, and Ax is larger than Bx. That is, it can be seen that the shape of the pattern 1 has too large ax / bx. Next, when considering pattern 2, B
x / Ax = 1.18, and Bx is larger than Ax. That is, it can be seen that ax / bx is too small in the shape of the pattern 2. Therefore, ax of the optimum cross-sectional area distribution
/ Bx exists between these two patterns. Under the optimal conditions for equalizing the maximum values Ax and Bx, ax becomes larger than bx because the vehicle just before the general section rushes into the tunnel more than the moment the vehicle front section rushes into the tunnel. This is because the tunnel cross-sectional area is substantially reduced by the area, and a large pressure gradient is obtained with a smaller cross-sectional area change rate.

Next, in the shape of the pattern 3, the ratio of the maximum values Ax and Bx of the pressure gradient distribution is Ax / Bx = 1.01, and the two peak values of the pressure gradient distribution are almost equal. However, the depression C of the pressure gradient distribution is deep, and Cx / Ax = 0.8
It is a small value of 3. That is, it is understood that the shape of the pattern 3 has a too small cx / ax.

Therefore, the distribution of the pressure gradient is approximated to a trapezoid, that is, the two maximum values Ax and Bx do not overlap with each other, and the value from the maximum value Ax to the maximum value Bx is more constant. If you think about
As described in the above problem, an extreme decrease in the minimum value cx of the cross-sectional area change rate that creates the depression C of the pressure gradient distribution should be avoided. Reducing the minimum value cx leads to deepening the depression C of the pressure gradient distribution, and the maximum values Ax, Bx
This is because it becomes a negative factor of keeping the value small.
Therefore, the minimum value Cx in the depression C is changed to the maximum values Ax and Bx.
Approach the value of (relatively maximum values Ax and Bx decrease)
Therefore, it is necessary to maintain the minimum value cx of the cross-sectional area change rate at a certain value or more. Therefore, C of patterns 1 to 3
Considering the value of x / max (Ax, Bx) (see FIG. 7), it is ideal that the value becomes 1, but the case where it exceeds 0.9 is regarded as the allowable range, and 0.9 ≦ Cx / max (A
The minimum value cx is determined so that x, Bx) ≦ 1.0.

Based on the above examination results, the above (1)
Ax = Bx and 0.9 ≦ Cx / max conforming to (2)
When the optimum cross-sectional area of the leading end shape was designed under the optimum condition of (Ax, Bx) ≦ 1.0, the analysis result of the pattern 4 could be obtained. That is, the maximum values Ax and Bx are both 9.56 (kPa / s), which are the same value, and the pattern 1
Values smaller than any of the maximum values of ~ 3 were obtained. The optimum cross-sectional area distribution based on such analysis results is shown in the diagram pattern 4 of FIG. 5, and the specifically designed shape of the head portion is shown in FIGS. 1 and 2. Also, when the pressure gradient distribution of the compression wave in FIG. 4 is viewed, the minimum value Cx in the depression C approaches the values of the maximum values Ax and Bx as compared with those of other patterns, and the distribution shape approaches the ideal trapezoid. I understand that.

Therefore, according to such a head portion shape, the maximum value of the pressure gradient of the compression wave generated by the micro-pressure wave is greatly reduced while the head portion length is the same as that of the conventional vehicle (700 series vehicle). I was able to. Specifically, when the head portion length L is 9.2 m, comparing the maximum value of the pressure gradient with the vehicle of the conventional shape shown in FIG. 10, it is 12.2 kPa / s for the conventional shape. The top shape 1 was 10.1 kPa / s. That is, according to the shape of the present embodiment, the maximum value of the pressure gradient that determines the magnitude of the micro-pressure wave can be reduced by 17%. The value of 17% can be said to be a very large value for reducing the micro-pressure wave because the power of the micro-pressure wave is proportional to the square of the pressure gradient.

However, the head shape designed in this way is ideal for high-speed railway vehicles that prevent the generation of micro-pressure waves, but the driver's cab with a window that the driver can directly see is taken into consideration. It wasn't what it was. In a driver's cab provided with a window having a sufficient field of view, the inclination of the window portion needs to be equal to or greater than a predetermined angle, so that the driver's cab is simply installed on the ideal head shape 1 described above. Only with this, the rate of change of the cross-sectional area is changed, and it is not possible to obtain a pressure gradient distribution that lowers the micro-pressure wave. Therefore, when a driver's cab that secures a driving visibility is installed below, Ax = Bx and 0.9 ≦ Cx / max (Ax, Bx) ≦
An embodiment of the head shape according to the present invention that satisfies the optimum condition of 1.0 will be described.

FIG. 8 is a cross-sectional area (broken line) in the leading portion shape in which the driver's cab is directly installed in the ideal leading portion shape.
It is a distribution diagram showing the cross-sectional area change rate (solid line). Since the driver's cab is formed in the intermediate portion 3 immediately before the rear portion 4, the cross-sectional area of the vehicle front portion at this time draws a curve as shown by the broken line in FIG. L
(Immediately before), the slope is gentle. Therefore, as shown by the solid line in the figure, the value of the cross-sectional area change rate immediately before the general portion becomes small, and even if the pressure gradient distribution is taken, two peaks A and B as shown in FIG. 4 do not appear. As shown by the broken line (Q) in FIG. 15 as an example, the pressure gradient distribution has one peak and the maximum value becomes large.

Therefore, with respect to the vehicle head portion of the high-speed railway vehicle including the driver's cab, Ax = Bx and 0.9 ≦ C described above.
The shape of the head portion that meets the optimum condition of x / max (Ax, Bx) ≦ 1.0 was examined. Then, as a result, the head portion shape as shown in FIGS. 9 to 11 was obtained. 9 to 11 are a front view, a side view, and a plan view showing an embodiment of a leading portion shape that satisfies the optimum condition, and each of the drawings shows the shape of a predetermined cross-sectional portion in an overlapping manner. . The leading portion shape 10 is divided into a front end portion 11, an intermediate portion 12 and a rear portion 13 and continues to a general portion 18, and a driver's cab 15 is installed from the rear of the intermediate portion 12 to the rear portion 13 as shown in FIG. ing.

In order to suppress the micro atmospheric pressure wave in the high-speed railway vehicle, it is effective to provide a portion having a large cross-sectional area change rate before and after the vehicle head portion in order to reduce the maximum value of the pressure gradient. As I did. Therefore, in the above-mentioned leading portion shape 1, the rate of change in the cross-sectional area of the rear portion 4 is increased by making it rise upward as shown in FIG. However, when the driver's cab 15 is installed like this time, the driver's cab 15 overlaps the rising portion of the rear portion 4 shown in FIG. 2, and the cross-sectional area change rate cannot be increased immediately before the general portion 18. Therefore, in the present embodiment, focusing on the width direction of the vehicle front portion, the cross-sectional area change rate is increased by increasing the vehicle width in the rear portion 13 immediately before the general portion 18.

The shape of the vehicle head portion of the conventional high-speed railway vehicle was expanded from the tip thereof to the same vehicle width as the general portion 18 all at once. Therefore, as described above, the top shape 1
In Fig. 2, the rate of change in the cross-sectional area of the rear portion 4 was formed to be large due to the upward rise. In contrast,
In the top portion shape 10 of the present embodiment, first, the shape of the front end portion 11 is formed with a large bulge in the vertical and horizontal directions at the tip end portion, but the left and right bulges are formed so as to be narrower than the general portion 18. Then, in the intermediate portion 12, FIG.
As shown in FIG. 5, the width of the cross-sectional area change is adjusted by bulging in the upward direction with almost no change from the front end portion 11 to the rear portion 13 while keeping the width narrower than the general portion 14.

The driver's cab 15 is arranged from the rear portion of the intermediate portion 12 to the rear portion 13, and its window portion 16 is formed with a slope capable of ensuring a sufficient field of view. Therefore, in the leading portion shape 10, the window portion 16 is largely bulged upward as shown in FIG. The width of the cab 15 is smaller than that of the intermediate portion 12. On the other hand, in the rear part 13,
In the portion where the cab 15 does not overlap, it changes upward so that the cross-sectional area change rate increases, and continues to the general portion 18, and further extends to the vehicle width of the general portion 18 in the left and right width directions. That is, in this embodiment, a large cross-sectional area change rate in the rear portion 13 immediately before the general portion 18 is ensured by increasing the vehicle width.

Next, the shape 10 of the leading portion meets the optimum condition of the pressure gradient (Ax = Bx and 0.9≤Cx / max (Ax, Bx) ≤1.0) effective for reducing the micro atmospheric pressure wave. The fulfillment will be described by showing the measurement result. This vehicle head is designed with a length L = 9.2 m and a maximum cross-sectional area (general section cross-sectional area) of 10.95 m2 (same as the 700 series vehicle). FIG. 12 is a diagram showing the cross-sectional area (broken line) and the cross-sectional area change rate (solid line) between the head portion shape 10 of the present embodiment and the conventional shape (700 series vehicle).

Further, FIG. 13 shows a pressure gradient distribution of a compression wave (270 km / h per hour) generated by the shape of the leading portion.
(When driving) is shown. FIG. 13 shows the pressure gradient distribution of the compression wave generated when the vehicle head enters the tunnel, as in the case of the measurement shown in FIG. It is the differential of the pressure change of the observed compression wave with respect to time. The vertical axis shows the pressure gradient, and the horizontal axis shows the time. v is the vehicle speed and L is the head length of the vehicle. The origin 0 of the time at the observation point is the time at which the sound wave generated at the moment when the vehicle head enters the tunnel entrance reaches the observation point. Since the observation point depends on the distance x from the entrance to the tunnel, if the speed of sound is represented by s, the origin of the time is shifted by x / s in this diagram.

Therefore, as can be seen from FIG. 12, the rate of change in the cross-sectional area of the top portion shape 10 is the largest at the front end portion 11, and behind it the peak (d, d) at the window portion 16 and the rear portion 13 of the cab 15. b) is made. Therefore, the rate of change of the cross-sectional area of the top portion shape 10 has peaks a, b, and b at positions corresponding to the front end portion 11, the rear portion 13, and the window portion 16 of the cab 15.
d was formed, and in the middle portion 12, depressions c appeared before and after the window portion 16. Then, in the pressure gradient distribution of the top portion shape 10 showing such a cross-sectional area change rate, two peaks A and B and a depression C between them appear as shown in FIG.
x and Bx are almost equal, and the minimum value Cx is 0.9.
It was within the range of ≦ Cx / max (Ax, Bx) ≦ 1.0. That is, the pressure gradient distribution of the top shape 10 is an ideal trapezoid satisfying the optimum condition.

This result is because the cross-sectional area change rate becomes large before and after the front end portion 11 and the window portion 16 and the rear portion 13, and the peaks A and B of the pressure gradient distribution due to the compression wave are dispersed. In the top shape 10, since the cab 15 is installed, there are two peaks of the cross-sectional area change rate in the rear (b,
d) It is possible, but since the distance between them is short, the pressure change of the compression wave generated in the window portion 16 and the rear portion 13 is differentiated with respect to time, and it appears overlapping the peak B of the pressure gradient distribution. This can be seen from the fact that the peak B portion has a gentle mountain shape. Then, between the peaks a and d of the cross-sectional area change rate of the front end portion 11 and the window portion 16, a depression c having a small cross-sectional area change rate is formed, which has a minimum value in the maximum value of the pressure gradient distribution. It became closer.

As described above, in the leading portion shape 10 of this embodiment, the vehicle width at the leading portion of the vehicle is made narrower than that of the general portion 18 and widened at the rear portion 13, so that an ideal shape having two peaks shown in FIG. 13 is obtained. It was possible to obtain various pressure gradient distribution shapes. Then, the maximum value of the pressure gradient with respect to the compression wave generated by the micro-pressure wave is calculated as follows.
The head length of the conventional shape was 12.2 kPa / s, while the head length was the same as that of the system vehicle), whereas the head shape 10 was 10.2 kPa / s. This reduces the maximum value of the pressure gradient that determines the magnitude of the micro-pressure wave by 16%, but since the power of the micro-pressure wave is proportional to the square of the pressure gradient, the micro-pressure wave is reduced. It's a very big effect.

Although one embodiment of the top portion shape of the high-speed railway vehicle according to the present invention has been described above, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention. Is. For example, it has been explained that the two maximum values Ax and Bx of the peaks A and B in the pressure gradient distribution are made equal, and thereby the maximum value of the pressure gradient is lowered, but if there is any difference between these maximum values Ax and Bx. Does not exclude

[0037]

According to the present invention, the shape of the vehicle front portion from the tip to the general portion having the maximum cross-sectional area in a high-speed railway vehicle is roughly divided into a front end portion, an intermediate portion and a rear portion, and a predetermined portion on the intermediate portion. A driver's cab provided with a window formed at an angle, the front end portion, the rear portion, and the window when the head shape is compared with the pressure gradient distribution of the compression wave generated by the tunnel entry at the head of the vehicle. The part is a part with a large cross-sectional area change rate that makes a peak in the pressure gradient distribution, and the middle part excluding the window part is a part with a small cross-sectional area change rate that makes a depression in the pressure gradient distribution. Is made narrower than the vehicle width of the general part and is increased at the rear part to increase the rate of change in the cross-sectional area of the rear part, and one peak is created in the pressure gradient distribution by each cross-sectional area change between the window part and the rear part, and that window With the rear and front and front end 2 of the pressure gradient which appears to correspond to the record
The maximum values of the two peaks are almost equal, and the value of the ratio of the local minimum values of the pressure gradient in the intermediate section that appears corresponding to the intermediate section with respect to the local maximum values of the intermediate sections does not overlap the two maximum values. Since the value is set within a predetermined range to make the value more constant, it is possible to provide a head portion shape of a high-speed railway vehicle that reduces the micro-pressure wave while suppressing the lengthwise dimension.

[Brief description of drawings]

FIG. 1 is a view showing a front shape of a leading portion of a high-speed railway vehicle.

FIG. 2 is a diagram showing a side surface shape of a leading portion of a high-speed railway vehicle.

FIG. 3 is a distribution diagram showing a cross-sectional area change rate of each pattern of a vehicle head portion having a head portion shape.

FIG. 4 is a pressure gradient distribution diagram of a compression wave of each pattern in the vehicle head portion having a head portion shape.

5 is a diagram showing a change in cross-sectional area corresponding to the shape of the head portion of each pattern shown in FIGS. 3 and 4. FIG.

6 is a table showing characteristics of a cross-sectional area change rate of each shape pattern shown in FIG.

FIG. 7 is a table showing characteristics of pressure gradient of each shape pattern shown in FIG.

8 is a distribution diagram showing a cross-sectional area (broken line) and a cross-sectional area change rate (solid line) in the case where the driver's cab is directly installed in the shape of the head portion shown in FIG.

FIG. 9 is a diagram showing a front shape of the leading portion of the high-speed railway vehicle according to the present invention.

FIG. 10 is a diagram showing a side surface shape of the leading portion of the high-speed railway vehicle according to the present invention.

FIG. 11 is a plan view showing the shape of the leading portion of the high-speed railway vehicle according to the present invention.

FIG. 12 is a top view of a shape 10 of the present embodiment and a conventional shape (7).
It is the figure which showed the cross-sectional area (broken line) with 100 series vehicles, and its cross-sectional area change rate (solid line).

FIG. 13 is a diagram showing a pressure gradient distribution of a compression wave caused by the shape of the head portion of the present embodiment.

FIG. 14 is a view showing a shape of a leading portion of a high-speed railway vehicle in a conventional example.

FIG. 15 is a distribution diagram showing a pressure gradient depending on the shape of the leading portion of a high-speed railway vehicle in a conventional example.

[Explanation of symbols]

10 Head shape 11 Front end 12 Middle part 13 rear 15 cab 16 windows 18 General Department

Claims (2)

[Claims] 1. A high-speed railway vehicle has a front-end portion, a middle portion, and a rear portion, which are roughly divided into a front-end portion, a middle portion, and a rear portion, and a predetermined angle on the middle portion. And a driver's cab provided with a window part, and the front end part, the rear part, and the window part are the same when the head shape is compared with the pressure gradient distribution of the compression wave generated by the tunnel entry at the head part of the vehicle. The part where the cross-sectional area change rate that makes a peak in the pressure gradient distribution is large, and the middle part excluding the window is the part where the cross-sectional area change rate that makes a depression in the pressure gradient distribution is small. It is made narrower than the vehicle width and increased at the rear part to increase the rate of change in the cross-sectional area at the rear part, and one peak is created in the pressure gradient distribution due to each cross-sectional area change at the window part and the rear part. Compatible with the front end The maximum values of the two peaks of the pressure gradient appearing are substantially equal to each other, and the value of the ratio of the minimum value of the pressure gradient in the intermediate section corresponding to the intermediate value to the maximum value overlaps the two maximum values. A shape of a leading portion of a high-speed railway vehicle, which is within a predetermined range that makes the value of the intermediate section more constant without being occluded. 2. The head portion shape of the high-speed railway vehicle according to claim 1, wherein the predetermined range has a ratio of a minimum value to the maximum value of 0.9 or more and 1.0 or less. The shape of the leading part of a high-speed rail car.