JP6742926B2 - Negative pressure wave generator - Google Patents

Description

The present invention relates to a negative pressure wave generator.

In recent years, speeding up of trains has been promoted for the purpose of shortening traveling time, and on the other hand, tunnel micro-pressure waves (hereinafter, referred to as micro-pressure waves in this specification) caused by speeding up of trains. ) Issue is taken up.

The micro-pressure wave is a pulsed pressure wave radiated from the tunnel entrance (exit) to the outside, and is generated when a train rushes into the tunnel at high speed. Specifically, when a train enters the tunnel from the wellhead (entrance) on one side, a compression wave is formed in the tunnel, and this compression wave propagates in the tunnel from one side to the other at the speed of sound. When reaching the wellhead (exit) on the other side, a pulsed pressure wave (micro-pressure wave) is emitted from the wellhead toward the outside of the tunnel.

This micro-pressure wave is a very low frequency sound, and may vibrate fittings or the like in a nearby house, which may cause vibration noise. As a technique for reducing the micro atmospheric pressure waves radiated from the tunnel entrance, there is, for example, the technique described in Patent Document 1.

JP-A-5-209405

In Patent Document 1, the timing at which the compression wave is radiated from the tunnel exit is calculated by detecting the compression wave in the tunnel generated at the time of train entry, and the negative pressure wave is emitted from the negative pressure wave generator at the timing. To cancel the compression wave.

However, the negative pressure wave radiated from the negative pressure wave generator described in Patent Document 1 has a shorter time width than the micropressure wave radiated from the tunnel exit, and therefore the effect of reducing the micropressure wave is obtained. Is small.

The present invention has been made in view of the above problems, and it is an object of the present invention to effectively reduce micro-pressure waves even with negative pressure waves having a short time width.

The negative pressure wave generator according to the first invention for solving the above-mentioned problems is a negative pressure wave generator that reduces the pressure of the micro-pressure wave radiated from the tunnel entrance by a negative pressure wave, and is arranged in the vicinity of the entrance. , A plurality of negative pressure wave generating means capable of radiating the negative pressure wave and an operation of the plurality of negative pressure wave generating means such that the plurality of negative pressure waves are superposed on the micropressure wave with a time difference. And a control means for controlling.

A negative pressure wave generator according to a second invention for solving the above-mentioned problems, in the negative pressure wave generator according to the first invention, wherein the plurality of negative pressure wave generating means, in the vicinity of the wellhead, radiates the micropressure waves. The negative pressure wave is arranged in a circle or in a straight line so that the negative pressure wave is radiated in the same direction.

A negative pressure wave generator according to a third invention for solving the above-mentioned problems is the negative pressure wave generator according to the first invention, wherein the plurality of negative pressure wave generating means are the negative pressure waves toward a predetermined designated point or a designated range. The control means is arranged so as to radiate pressure waves, and the control means generates the plurality of negative pressure waves based on a distance between the plurality of negative pressure wave generation means and the predetermined designated point or designated range. It is characterized in that it controls the operation of the means.

A negative pressure wave generator according to a fourth invention for solving the above-mentioned problems is the negative pressure wave generator according to the first invention, wherein the plurality of negative pressure wave generators are directed to a plurality of different predetermined designated points or designated ranges. Is arranged so that the negative pressure wave is radiated, and the control means controls the plurality of negative pressure wave generation means based on respective distances between the plurality of negative pressure wave generation means and the predetermined designated point or designated range. It is characterized in that it controls the operation of the negative pressure wave generating means.

A negative pressure wave generating device according to a fifth invention for solving the above-mentioned problems is the negative pressure wave generating device according to the first invention, wherein the plurality of negative pressure wave generating means are provided toward the wellhead, and The control means controls the operation of the plurality of negative pressure wave generation means based on the distance between the plurality of negative pressure wave generation means and the wellhead.

According to the negative pressure wave generator of the first aspect of the present invention, it is possible to effectively reduce the micro atmospheric pressure wave even if the negative pressure wave has a short time width.

According to the negative pressure wave generation device of the second invention, it is possible to effectively reduce the micro pressure wave over the range affected by the micro pressure wave.

According to the negative pressure wave generator of the third aspect of the present invention, the micro pressure wave can be effectively reduced at a predetermined designated point or designated range.

According to the negative pressure wave generator of the fourth aspect of the present invention, it is possible to effectively reduce the micro atmospheric pressure wave at a plurality of different predetermined designated points or designated ranges.

According to the negative pressure wave generation device of the fifth aspect of the invention, the micro-pressure wave radiated from the wellhead can be effectively reduced.

It is explanatory drawing which shows the structure of the negative pressure wave generator which concerns on Example 1. It is explanatory drawing (II arrow line view in FIG. 1) which shows the structure of the negative pressure wave generator which concerns on Example 1. It is explanatory drawing (III arrow view in FIG. 1) which shows the structure of the negative pressure wave generator which concerns on Example 1. FIG. 5 is a graph showing the effect of the negative pressure wave generation device according to the first embodiment. 5 is a graph showing the effect of the negative pressure wave generation device according to the first embodiment. It is explanatory drawing (equivalent to the II arrow view in FIG. 1) which shows the structure of the negative pressure wave generator which concerns on Example 2. FIG. 8 is an explanatory view (corresponding to a view taken along an arrow II in FIG. 1) showing a modified example in which the arrangement of the negative pressure wave generator in the negative pressure wave generator according to the second embodiment is changed. It is explanatory drawing (equivalent to the II arrow view in FIG. 1) which shows the structure of the negative pressure wave generator which concerns on Example 3. FIG. 9 is an explanatory view (corresponding to a view taken along an arrow II in FIG. 1) showing a modified example in which the arrangement of the negative pressure wave generator in the negative pressure wave generator according to the third embodiment is changed.

Hereinafter, embodiments of the negative pressure wave generator according to the present invention will be described in detail with reference to the accompanying drawings. Of course, the present invention is not limited to the following examples, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[Example 1]
The structure of the negative pressure wave generator according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

As shown in FIG. 1, the negative pressure wave generator 1 includes a negative pressure wave generator (negative pressure wave generating means) 11 provided in the vicinity of a wellhead 21 in a tunnel 2 and a pressure detector (micropressure wave) provided in the tunnel 2. Radiation timing detection means) 12 and a controller (control means) 13 electrically connected to the negative pressure wave generator 11 and the pressure detector 12.

The negative pressure wave generator 11 is capable of radiating a negative pressure wave W ₁ that spreads in a hemispherical shape in a predetermined direction, and the negative pressure wave W ₁ is a micro atmospheric pressure radiated from the wellhead 21 of the tunnel 2. by being overlapped with the wave W _2, in which it is possible to reduce the micro-pressure waves W ₂ of the amplitude (pressure) (see FIG. 2).

Here, the micro-pressure wave W ₂ is generated when the train 3 rushes into the tunnel 2 at high speed. In particular, (in FIG. 1, left side) train 3 is one side when rush from wellhead 21 into the tunnel 2, is in the tunnel 2 is formed compression wave W _3, this compression wave W ₃ Tunnel 2 propagates from one side to the other side (right side in FIG. 1) at the speed of sound and reaches the wellhead 21 on the other side, the pulsed pressure wave from the wellhole 21 to the outside of the tunnel 2. (Micro-pressure wave) W ₂ is radiated (see FIG. 2).

As shown in FIG. 3, a plurality of negative pressure wave generators 11 (eight in FIG. 3) are attached to the wall portion 22 forming the wellhead 21 at substantially equal intervals so as to surround the wellhead 21. 2, the negative pressure wave W ₁ is emitted in the same direction as the direction in which the micro-pressure wave W ₂ is emitted from the wellhead 21 (the direction from the left side to the right side in FIG. 2). It is arranged so that.

As a matter of course, the negative pressure wave generating means in the present invention is not limited to the one arranged at equal intervals on the substantially circumference so as to surround the wellhead 21 as in the present embodiment. For example, it may be arranged on a straight line in the vertical direction, the horizontal direction, or the like around the wellhead, or may be arranged continuously (close to each other) without an interval.

Therefore, the micro-pressure wave W ₂ radiated from the wellhead 21 becomes the micro-pressure wave W ₂ from the negative pressure wave generator 11 located near the source (center of the well-hole 21) C ₂₁ of the micro-pressure wave W ₂ . It will be superposed with the negative pressure wave W ₁ radiated in the same direction. Thus, the amplitude (pressure) of the micro pressure wave W ₂ is reduced by superimposing the micro pressure wave W ₂ on the negative pressure wave W ₁ .

The pressure detector 12 detects the pressure (atmospheric pressure) in the tunnel 2, and the detection result detected by the pressure detector 12 is sent to the controller 13 (see FIG. 1). When the compression wave W ₃ is formed and propagates in the tunnel 2, a large pressure difference occurs before and after the compression wave W ₃ propagates. When the pressure difference (pressure change) is detected by the pressure detector 12, the controller 13 determines that the compression wave W ₃ has passed the installation position of the pressure detector 12.

The controller 13, based on a detection result detected by the pressure detector 12, the installation position of whether the compression wave W ₃ passing through the installation position of the pressure detector 12 or (compression wave W ₃ is a pressure detector 12 The timing at which the micro pressure wave W ₂ is radiated from the wellhead 21 (micro pressure wave emission timing) is calculated, and the micro pressure wave emission obtained by this calculation is calculated. The operation of each of the plurality of negative pressure wave generators 11 is controlled based on the timing. The micro-pressure wave emission timing can be obtained from the distance from the installation position of the pressure detector 12 to the wellhead 21 and the propagation velocity (sonic velocity) of the compression wave W ₃ .

The operation of the negative pressure wave generator according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 5.

When the train 3 enters from one side of the wellhead 21 into the tunnel 2 is formed compression wave W ₃ in the tunnel 2, the compression wave W ₃ being at substantially sonic speed toward the inside of the tunnel 2 from one side to the other side Propagate.

At this time, when the compression wave W ₃ passes through the installation position of the pressure detector 12 in the tunnel 2, the pressure detector 12 detects the pressure change (the pressure difference before and after the propagation of the compression wave W ₃ ). When the pressure difference due to the propagation of the compression wave W ₃ is transmitted to the controller 13 as the detection result of the pressure detector 12, the controller 13 causes the compression wave W ₃ to pass through the installation position of the pressure detector 12 (compression). Wave passage timing), and the micro-pressure wave emission timing is calculated from the distance from the installation position of the pressure detector 12 to the wellhead 21 and the propagation velocity (sonic velocity) of the compression wave W ₃ .

Then, the controller 13 causes the negative pressure wave generator 11 to radiate the negative pressure wave W ₁ so that the timing (negative pressure wave emission timing) is a predetermined timing with respect to the calculated micro-pressure wave emission timing. The operation of the generator 11 (including the preparatory operation for radiating the negative pressure wave W ₁ ) is controlled.

Then, when the compression wave W ₃ propagates in the tunnel 2 and reaches the wellhead 21 on the other side, a pulsed micro-pressure wave W ₂ is emitted from the wellhole 21 toward the outside of the tunnel 2 and the minute pressure wave W ₂ is emitted. The negative pressure wave W ₁ is emitted from the negative pressure wave generator 11 at a predetermined timing with respect to the atmospheric pressure wave emission timing. Therefore, the negative pressure wave W ₁ against micro-pressure waves W ₂ are superimposed at a predetermined timing, the amplitude of the micro-pressure waves W ₂ (pressure) is effectively reduced.

As a predetermined timing at which the negative pressure wave W ₁ and the micro pressure wave W ₂ are superposed, for example, a plurality of negative pressure waves W ₁ are simultaneously emitted at the same timing as the micro pressure wave W ₂ (see FIG. 4 ). The controller 13 controls the operation of the negative pressure wave generators 11. That is, by the operation control of the controller 13, the timing at which the negative pressure waves W ₁ have the peak value P _W1 and the timing at which the micro pressure waves W ₂ have the peak value P _W2 coincide (in FIG. 4, the negative pressure waves The negative pressure waves W ₁ are simultaneously emitted from the plurality of negative pressure wave generators 11 so that the peak value P _{W1 of} W ₁ and the peak value P _W2 of the micro-pressure wave W ₂ coincide with each other on the time axis (horizontal direction). ..

Here, FIG. 4 is a graph showing changes in pressure wave (waveform of pressure) before and after a predetermined time, and in FIG. 4, the negative pressure wave W ₁ and the micropressure wave W ₂ are each represented by a chain double-dashed line. , One negative pressure wave W ₁ superposed on the micro atmospheric pressure wave W ₂ (W ₂ +W ₁ ) is shown by a broken line, and two negative pressure waves W ₁ superposed on the micro atmospheric pressure wave W ₂ (W ₂ +2W ₁ ) is represented by a one-dot chain line, and three negative pressure waves W ₁ superposed on the micro-pressure wave W ₂ (W ₂ +3W ₁ ) are represented by a solid line.

As described above, the controller 13 controls the operations of the plurality of negative pressure wave generators 11 and simultaneously radiates the plurality of negative pressure waves W ₁ at the same timing as the micro-pressure wave W ₂ to obtain the plurality of negative pressure waves W ₁ . superposing the micro-pressure waves W ₂ at the same timing, the amplitude of the micro-pressure waves W ₂ (pressure) can be significantly reduced at the timing at which the peak value P _W2.

Further, at a predetermined timing at which the negative pressure wave W ₁ and the micro pressure wave W ₂ are superposed, for example, a part of the negative pressure wave W _1a is generated from the negative pressure wave generator 11 by the operation control of the controller 13. _The controller 13 controls the plurality of negative pressure wave generators 11 so that the negative pressure waves W _1b and W _1c are emitted at the same timing as ₂ and the other negative pressure waves W _1c and W _1c are emitted at timings different from the micropressure wave W ₂ (see FIG. 5). Control movements. That is, by the operation control of the controller 13, the timing at which a part of the negative pressure wave W _1a has the peak value P _W1a and the timing at which the micro-pressure wave W ₂ has the peak value P _W2 coincide, and the other negative pressure waves W _1b , _Negative pressure waves W _1a are provided with a time difference from the plurality of negative pressure wave generators 11 so that the timing at which W _1c becomes the peak values P _W1b and P _W1c and the timing at which the micro pressure wave W ₂ becomes the peak value P _W2 are different. W _1b and W _1c are emitted.

Here, FIG. 5 is a graph showing changes in pressure waves (waveforms of pressure) before and after a predetermined time, and in FIG. 5, negative pressure waves W _1a , W _1b , W _1c and micro pressures with time differences are provided. Each of the waves W ₂ is represented by a chain double-dashed line, and negative pressure waves W _1a , W _1b , W _1c with a time difference are superimposed on the micro-pressure wave W ₂ (W ₂ +W _1a +W _1b +W _1c ) are represented by a solid line. ing. The negative pressure wave W _1a is of the same timing as micro-pressure waves W _2, the negative pressure wave W _1b is slightly earlier than micro-pressure waves W _2, i.e., micro-pressure waves W ₂ is the peak value P It becomes the peak value P _W1b before it becomes _W2 , and the negative pressure wave W _1c is slightly later than the micro pressure wave W ₂ , that is, after the micro pressure wave W ₂ becomes the peak value P _W2. The peak value is P _W1c .

In this way, the controller 13 controls the operation of the negative pressure wave generators 11 and radiates the negative pressure waves W _1a , W _1b , W _1c with a time lag, so that the negative pressure waves W _1a , The pressure of the micro pressure wave W ₂ can be reduced as a whole by superimposing W _1b and W _1c on the micro pressure wave W ₂ at the same timing or different timing.

Note that when the time width [Delta] T ₁ of the negative pressure wave W ₁ capable of emitting the negative pressure wave generator 11 is long, it is preferable to superimpose a plurality of negative pressure wave W ₁ at the same time at the same timing as the micro-pressure waves W ₂ (Fig. 4). On the other hand, if the time width shorter [Delta] T ₁ of the radiating possible negative pressure wave W ₁ by the negative pressure wave generator 11, a plurality of negative pressure wave W _1a with a time difference, W _1b, the W _1c and micro-pressure waves W ₂ superimposed It is preferable to match (see FIG. 5).

As described above, in the present embodiment, the plurality of negative pressure wave generators 11 are arranged around the wellhead 21 of the tunnel 2 at substantially equal intervals, and the negative pressure wave W ₁ is in the same direction as the micropressure wave W _2. Are arranged so as to be radiated, and the negative pressure waves W ₁ are radiated from the plurality of negative pressure wave generators 11 at the same time or with a time difference, so that the amplitude of the micro-pressure wave W ₂ radiated from the well 21 of the tunnel 2 is increased. (Pressure) is effectively reduced.

Here, the negative pressure wave generator 11 is not particularly limited as long as it can generate the negative pressure wave W ₁ that can reduce the micro pressure wave W ₂ . Further, the radiation timing detection means in the negative pressure wave generation device according to the present invention is not limited to the pressure detector 12 provided in the tunnel 2 as in the present embodiment, and any radiation pressure microwave radiation timing can be detected. good.

[Example 2]
The structure of the negative pressure wave generator according to the second embodiment of the present invention will be described with reference to FIG.

The negative pressure wave generator 101 according to the present embodiment includes a negative pressure wave generator 111 having a different layout from the negative pressure wave generator 11 in the negative pressure wave generator 1 according to the first embodiment. Constituent elements having the same functional configuration will be denoted by the same reference numerals, and redundant description will be appropriately omitted.

As shown in FIG. 6, the negative pressure wave generator 111 is located outside the tunnel 2 (on the right side in FIG. 5), and a direction in which the micro-pressure wave W ₂ is emitted from the wellhead 21 of the tunnel 2 (see FIG. 6 is arranged so as to emit the negative pressure wave W ₁ toward a predetermined designated point (or designated range) Q in a direction different from the direction from the left side to the right side).

Here, the negative pressure wave W ₁ radiated from the negative pressure wave generator 111 is superimposed on the micropressure wave W ₂ radiated from the wellhead 21 of the tunnel 2, so that the amplitude (pressure) of the micropressure wave W ₂ is generated. Can be reduced. Note that the negative pressure wave generator 111 is not particularly limited as long as it can generate the negative pressure wave W ₁ that can reduce the micro pressure wave W ₂ .

By thus radiating the negative pressure wave W ₁ toward the predetermined designated point Q, the influence of the micro-pressure wave W _{2 at} the designated point Q can be particularly reduced.

When reducing the influence of the micro pressure wave W _{2 at} the designated point Q by the negative pressure waves W ₁ radiated from the plurality of negative pressure wave generators 111, the controller 113 controls the negative pressure wave generator 111 and the micro pressure wave. The operation of each of the negative pressure wave generators 111 is controlled based on the positional relationship between the transmission source (center of the wellhead 21) C _{21 of the} wave W ₂ and the designated point Q.

That is, the controller 113 causes the source distance L ₂₁ between the source C ₂₁ and the designated point Q and the generator distances L _111a and L _111b between the negative pressure wave generators 111a and 111b and the designated point Q. Based on the above, the negative pressure wave emission timing with respect to the minute pressure wave emission timing is controlled so that a plurality of negative pressure waves W ₁ are simultaneously overlapped with the minute pressure wave W ₂ at the same timing, or a plurality of negative pressure waves W are provided with a time difference. ₁ is superimposed on the micro-pressure wave W ₂ .

For example, the controller 113, source C ₂₁ operates the difference as soon as the negative pressure wave generator 111a, which is located remotely from the specified point Q and source distance L ₂₁ between generator distance L _111a than, source as the negative pressure wave generator 111b which is located near the specified point Q than C ₂₁ is operated slowly by the difference between the source distance L ₂₁ generator distance L _111b, the operation of the plurality of negative pressure wave generator 111 Control.

Thus, by a plurality of negative pressure wave generator 111 (111a, 111b) based on the positional relationship between the source C ₂₁ and the specified point Q, the controller 113 controls the operation of the negative pressure wave generator 111, At the designated point Q, it is possible to effectively reduce the amplitude (pressure) of the micro pressure wave W ₂ by superimposing the plurality of negative pressure waves W ₁ and the micro pressure wave W ₂ at a predetermined timing.

Further, as shown in FIG. 7, when there are a plurality of designated points (or designated ranges) Qa, Qb, the amplitude (pressure) of the micro-pressure wave W ₂ at these designated points Qa, Qb is effectively reduced. as negative pressure wave generating device 201 for a plurality of designated points Qa, to emit negative pressure wave W ₁ respectively towards Qb, a plurality of negative pressure wave generator 211 (211a, 211b) may be disposed.

At this time, the controller 213, the negative pressure wave generator 211a, 211b and source C ₂₁ and the specified point Qa, based on the positional relationship between the Qb, and controls a plurality of negative pressure wave generator 211a, the operation of 211b, respectively.

That is, the controller 213 generates the source distances L _21a and L _21b between the source C ₂₁ and the designated points Qa and Qb, and the generation between the negative pressure wave generators 211a and 211b and the designated points Qa and Qb. vessel length L _211a, based on the L _211b, to control the negative pressure wave radiation timing for the micro-pressure wave radiation timing, a plurality of negative pressure wave W ₁ is superimposed at the same time as micro-pressure waves W ₂ at the same time, or the time difference A plurality of negative pressure waves W ₁ are provided so as to be superposed on the micro pressure waves W ₂ .

Thus, a plurality of negative pressure wave generator 211 (211a, 211b) and source C ₂₁ and a plurality of specified points Qa, based on the positional relationship between Qb, the controller 213 controls the operation of the negative pressure wave generator 211 By doing so, at the plurality of designated points Qa and Qb, the plurality of negative pressure waves W ₁ and the micro pressure waves W ₂ are superposed at a predetermined timing, and the amplitude (pressure) of the micro pressure waves W ₂ is effectively reduced. can do.

[Example 3]
The structure of the negative pressure wave generator according to the third embodiment of the present invention will be described with reference to FIG.

The negative pressure wave generator 301 according to the present embodiment includes a negative pressure wave generator 311 having a different arrangement from the negative pressure wave generator 11 in the negative pressure wave generator 1 according to the first embodiment. Constituent elements having the same functional configuration will be denoted by the same reference numerals, and redundant description will be appropriately omitted.

As shown in FIG. 8, the negative pressure wave generator 311 is located outside the tunnel 2 (on the right side in FIG. 8) in a direction different from the micro-pressure wave W ₂ emitted from the wellhead 21 of the tunnel 2. Therefore, the negative pressure wave W ₁ is radiated toward the transmission source (center of the wellhead 21) C ₂₁ of the micro-pressure wave W ₂ .

Here, the negative pressure wave W ₁ radiated from the negative pressure wave generator 311 suppresses the generation of the micro pressure wave W ₂ radiated from the wellhead 21 of the tunnel 2 to reduce the amplitude (pressure) of the micro pressure wave W _2. ) Can be reduced. Note that the negative pressure wave generator 311 may be any one as long as it can generate the negative pressure wave W ₁ that can suppress the generation of the micro-pressure wave W ₂ , and the configuration thereof is not particularly limited.

Thus, by emitting towards the negative pressure wave W ₁ to the source C _21, micro-pressure waves W ₂ suppresses the production of the micro-pressure waves W ₂ at the time of being emitted from the wellhead 21, the wellhead 21 The amplitude (pressure) of the emitted micro-pressure wave W ₂ can be reduced.

In addition, when the micro pressure wave W ₂ generated in the transmission source C ₂₁ is reduced by the negative pressure wave W ₁ radiated from the plurality of negative pressure wave generators 311, the controller 313 transmits the negative pressure wave generator 311 and the negative pressure wave generator 311. The operation of each of the plurality of negative pressure wave generators 311 is controlled based on the positional relationship with the source C ₂₁ .

That is, the controller 313 controls the negative pressure wave emission timing with respect to the micro pressure wave emission timing on the basis of the generator distances L _311a and L _311b between the negative pressure wave generators 311a and 311b and the transmission source C _21. negative pressure wave W ₁ reaches the source C ₂₁ of micro-pressure waves W ₂ at the same time, or a negative pressure wave W ₁ more with a time difference so as to reach the source C ₂₁ of micro-pressure waves W ₂ of ..

For example, the controller 313 controls the operation of the plurality of negative pressure wave generators 311 so that the negative pressure wave generators _311a and _311b operate faster by the generator distances L _311a and L _311b .

In this way, the controller 313 controls the operation of the negative pressure wave generator 311 based on the positional relationship between the transmission source C ₂₁ and the negative pressure wave generator 311 (311a, 311b), and the radiation is emitted from the wellhead 21. The amplitude (pressure) of the micro atmospheric pressure wave W ₂ can be effectively reduced.

Further, as shown in FIG. 9, as the negative pressure wave generator 401 for effectively reducing the amplitude (pressure) of the micro-pressure wave W ₂ radiated from the wellhead ₂₁ , the negative pressure wave W is directed toward the transmission source C _{21. A} plurality of negative pressure wave generators 411 may be opposed to each other and attached to the wall portion 22 so as to emit ₁ .

At this time, the controller 413, the negative pressure wave generator 411a, based on the positional relationship between the source C ₂₁ and 411b, and controls a plurality of negative pressure wave generator 411a, the operation of 411b, respectively. That is, the controller 413 controls the negative pressure wave emission timing with respect to the micro pressure wave emission timing based on the distances L _411a and L _{411b from} the center of the wellhead 21 (source of the micro pressure wave W ₂ ) C _21. a plurality of negative pressure wave W ₁ reaches the source C ₂₁ of micro-pressure waves W ₂ at the same time, or, as a plurality of negative pressure wave W ₁ reaches the source C ₂₁ of micro-pressure waves W ₂ with a time difference To

In this way, the controller 413 controls the operation of the negative pressure wave generator 411 based on the positional relationship between the transmission source C ₂₁ and the negative pressure wave generator 411 (411a, 411b), and the radiation is emitted from the wellhead 21. Generation of the micro pressure wave W ₂ can be suppressed, and the amplitude (pressure) of the micro pressure wave W ₂ can be effectively reduced.

1 Negative Pressure Wave Generator 2 Tunnel 3 Train 11 Negative Pressure Wave Generator (Negative Pressure Wave Generating Means)
12 pressure detector 13 controller (control means)
21 Wellhead 22 Wall 101 Negative Pressure Wave Generator 111 Negative Pressure Wave Generator 113 Controller 201 Negative Pressure Wave Generator 211 Negative Pressure Wave Generator 213 Controller 301 Negative Pressure Wave Generator 311 Negative Pressure Wave Generator 313 Controller 401 Negative Pressure Wave Generator 411 Negative pressure wave generator 413 Controller C ₂₁ Micro pressure wave source (center of wellhead)
W ₁ Negative pressure wave W ₂ Micro pressure wave W ₃ Compressed wave ΔT ₁ Negative pressure wave time width ΔT ₂ Micro pressure wave time width

Claims (5)

A negative pressure wave generator for reducing the pressure of a micro-pressure wave radiated from a tunnel wellhole by a negative pressure wave,
A plurality of negative pressure wave generating means arranged near the wellhead and capable of radiating the negative pressure wave,
Negative pressure wave generation, comprising: a control means for controlling the operation of the plurality of negative pressure wave generation means so that the plurality of negative pressure waves are superimposed on the micropressure wave with a time difference. apparatus. The plurality of negative pressure wave generating means are arranged on the circumference or on a straight line so that the negative pressure wave is emitted around the wellhead in the same direction as the direction in which the micropressure wave is emitted. The negative pressure wave generator according to claim 1. The plurality of negative pressure wave generating means is arranged so that the negative pressure wave is radiated toward a predetermined designated point or a designated range,
The control means controls the operation of the plurality of negative pressure wave generation means based on the distance between the plurality of negative pressure wave generation means and the predetermined designated point or designated range. The negative pressure wave generator according to claim 1. The plurality of negative pressure wave generating means is arranged so that the negative pressure wave is radiated toward a plurality of different predetermined designated points or designated ranges,
The control means controls the operation of the plurality of negative pressure wave generation means based on respective distances between the plurality of negative pressure wave generation means and the predetermined designated point or designated range. The negative pressure wave generator according to claim 1. The plurality of negative pressure wave generating means is provided toward the wellhead,
The negative pressure wave according to claim 1, wherein the control means controls the operation of the plurality of negative pressure wave generation means based on the distance between the plurality of negative pressure wave generation means and the wellhead. Generator.