JP2560591B2 - Detonation liquid pressure generation method and apparatus therefor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detonation hydraulic pressure generating method and a device therefor capable of easily obtaining an impact hydraulic pressure having a desired waveform at a high pressure.

[0002]

2. Description of the Related Art Conventionally, the following techniques have been known as a technique for generating an impact hydraulic pressure.

For example, first of all, a bullet is driven into a liquid such as water for pressurization to generate an impact hydraulic pressure in the liquid,
An impact hydraulic pressure generating device that applies the pressure to a member such as a plate material and presses the member against a mold to form a three-dimensional molding screw is disclosed in Japanese Patent Application Laid-Open No. H01-001
It is proposed in 157725.

Secondly, there is also known an explosive molding apparatus for producing an impact water pressure by burning explosives in water and performing three-dimensional molding of a thin plate by the pressure. This device is mainly used for molding large parts.

Thirdly, there is known a device in which an impact hydraulic pressure is generated by causing a piston accelerated at high speed by gas pressure to collide with the liquid surface of a liquid for pressurization contained in a container. Has been.

[0006]

However, the methods of generating the impact hydraulic pressure by the above-mentioned first to third devices have common or unique problems as follows.

The shape or size of the hydraulic chamber must be determined in consideration of the behavior of the energy source (explosive charge, high-speed projectile), and the degree of freedom is considerably small.

The pressure has a long duration, and the impact pressure is applied simultaneously over a relatively wide range in the hydraulic chamber.

Due to the danger, it is necessary to consider restrictions on the installation site or safety.

It is difficult to significantly change the ultimate pressure.

Only part of the pressure wave generated in the hydraulic chamber is effectively used (energy utilization efficiency is low).

The structure is not such that the reflected wave generated on the inner wall of the hydraulic chamber or the surface to be processed can be effectively utilized.

A large amount of liquid used as a pressure medium. The vacuum cannot be reduced below the vapor pressure of the liquid itself as the pressure medium.

Direct contact of the work piece with a liquid as a pressure medium.

That is, in the above first method,
The second method has the following disadvantages, and the third method has the following disadvantages.

An object of the present invention is to solve the above-mentioned problems in the prior art and to provide a method and a device therefor for safely and reliably controlling the pattern of impact hydraulic pressure generation. is there.

[0017]

According to the present invention, the above object relates to a detonation liquid pressure generating method, in which a detonation wave generated by igniting a combustible air-fuel mixture is converged with its progress, and the detonation wave is converged at a converging portion. In the method of transferring the obtained high pressure to a liquid and converting it into a liquid pressure, it is achieved by changing the shape and size of the hydraulic chamber for containing the liquid or the physical properties of the liquid to generate different patterns of liquid pressure. .

An apparatus for carrying out the above method is
A combustion chamber whose cross-sectional area decreases from one end to the other end,
An ignition chamber in which fuel is supplied and an ignition plug is disposed, a plurality of guide paths that branch from the ignition chamber and communicate with one end of the combustion chamber and have the same path length, and are the minimum cross-sectional area of the combustion chamber. It is provided by including a hydraulic chamber connected to the opening at the other end and having a replaceable nozzle installed in the minimum cross-sectional area.

According to the present invention, in the hydraulic chamber, the nozzle diameter of the opening connected to the combustion chamber can be changed, and the shape and size of the container for storing the liquid can be a shape (for example, a shape suitable for the workpiece). By changing the physical properties of the liquid in the container (cone, pyramid, etc.), various hydraulic pressure generation patterns suitable for the application can be obtained.

On the other hand, if the liquid in the liquid pressure chamber is in contact with the gas in the combustion chamber through the film body, it is possible to evacuate the combustion chamber to a pressure below the vapor pressure of the liquid itself. .

Further, if the drain means for matching the minimum cross-sectional area portion and the liquid surface position is provided, the maximum pressure generating portion in the combustion chamber and the liquid surface always match. As a result, it becomes possible to maintain the maximum transmittance of the pressure wave from the combustion gas to the liquid (the higher the pressure of the combustion gas, the higher the transmittance).

Further, if a side wall is installed in which the passage cross-sectional area downstream from the minimum cross-sectional area portion continuously increases or becomes constant, a discontinuous portion (edge portion) of the inner wall surface is provided.
It is possible to suppress the energy loss on the wall surface due to the propagation of the shock wave, because the phenomenon such as the generation of a new shock wave does not occur in the above.

When the wall shape of the hydraulic chamber is set so that the rate of increase of the passage cross-sectional area increases monotonously (for example,
When the shape of the hydraulic chamber is set to a conical shape that expands downstream), the shock wave front surface propagating in the hydraulic chamber propagates while maintaining a substantially spherical shape. Then, for example, when the thin plate for processing is installed horizontally at the processing position of the hydraulic chamber, since the shock wave is a spherical wave, it is necessary to add an impact load that moves from the central part to the outer peripheral part to this plate. Is possible. On the other hand, when the cross-sectional area is set to be a constant value after the passage cross-sectional area is continuously increased with respect to the propagation direction of the shock wave, interference with the wall surface and the shock wave front at a portion where the cross-sectional area is constant are set. Energy exchange and the like occur in the chamber, and the shock wave is exchanged from a spherical shape to a planar shape. And in this case,
For example, for a plate to be processed horizontally installed at the processing position of the hydraulic chamber, it is possible to apply an impact load to the entire plate at the same time.

Furthermore, when the liquid in the hydraulic chamber is brought into contact with the workpiece through the film body, the liquid does not come into direct contact with the workpiece, and the liquid can be injected into the hydraulic chamber. It can be carried out under pressure. Therefore, the handling of the workpiece becomes easy.

If the above-mentioned hydraulic chamber is installed,
The reflected wave generated when the shock wave collides with the machined surface returns and converges to the nozzle part, then is reflected at the open end (nozzle part) on the combustion chamber side and propagates again toward the machined surface. Can be effectively used. That is, by collecting the non-uniform reflected waves from the work piece in one place, a new shock wave can be reproduced and used as a wave for processing.

[0026]

In the present invention, the detonation hydraulic pressure is obtained as follows.

First, the combustible chamber, the guide passage, and the ignition chamber, which can communicate with each other, are filled with a combustible gas mixture having a substantially theoretical mixture ratio.

Next, ignition is performed in the ignition chamber.

When ignited, the flame advances in the combustion chamber through the taxiway due to the detonation. that time,
Since the guide paths have the same path length, each guide path flame reaches one end of the combustion chamber at the same time.

In the combustion chamber, the flame propagates toward the other end, but since the cross-sectional area of the combustion chamber decreases toward the other end, the flame pressure rises and reaches the maximum value at the other end. . Since the hydraulic chamber is connected to the opening of the other end and the liquid surface faces the opening, the pressure is transmitted to the liquid in the hydraulic chamber. In that case, the above-mentioned hydraulic pressure pattern can be changed to a shape suitable for the workpiece by changing the shape and size of the hydraulic chamber formed downstream from the other end which is the minimum cross-sectional area and the physical properties of the liquid. it can.

The pressure of the liquid in the liquid pressure chamber is processed by pressing the work member on the mold directly or through the film body against the mold.

[0032]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a vertical sectional view of an apparatus according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a combustion chamber, which has a downward conical shape and has a maximum cross-sectional area at the upper end 1A and a minimum cross-sectional area at the lower end 1B to form a convergent portion.

The inner wall of the upper end portion 1A of the combustion chamber 1 is curved slightly upward, and a plurality of hole-shaped guide passages 2 communicate therewith. The plurality of guide paths 2 are focused on a disk-shaped dispersion chamber 3 at the top. An ignition chamber 4 extending upward is connected to the dispersion chamber 3 so as to communicate therewith. An ignition plug 5 which is operated by an ignition device 6 is provided above the ignition chamber 4, and a fuel supply source 9 and an oxidant supply source 10 are connected via flowmeters 7 and 8, respectively. . Reference numeral 11 denotes a pressure gauge for checking the pressure in the ignition chamber 4.

A lower end portion 1B of the combustion chamber 1 is opened, a hydraulic chamber 12 is connected thereto, and a molding device 13 is provided immediately below the hydraulic chamber 12 as an example of using hydraulic pressure. A liquid such as water as a pressure medium is contained in the hydraulic chamber 12, but the liquid surface is strong and easily deformable even if it directly faces the lower end portion 1B of the combustion chamber 1 as shown in the drawing. The intermediate surface may be formed by a film body. A pipe 14 for venting air is connected to the hydraulic chamber 12 via a valve, and a liquid supply device 15 such as water for hydraulic pressure is connected via a valve.

The molding apparatus 13 accommodates a mold 16 whose upper surface has a three-dimensional shape for molding in a replaceable manner. If necessary, the molding device 13 can hold the peripheral edge of the plate material P or the like to be subjected to molding between the hydraulic chamber 12 and, for example, both flanges. The molding device 13 is connected to a vacuum pump device 17 that penetrates the mold 16 and communicates with an upper space thereof to evacuate the space. The vacuum pump device 17 is also connected to the ignition chamber 4 described above.

In the apparatus of this embodiment, generation of high-pressure liquid pressure and molding using this are performed as follows.

First, the plate material P to be molded is set on the die 16.

Next, the vacuum pump device 17 brings the ignition chamber 4, the dispersion chamber 3, the guide passage 2 and the combustion chamber 1 to a predetermined degree of vacuum. At the same time, the space between the mold 16 and the plate material P is also sucked so as to have a predetermined degree of vacuum.

Thereafter, the hydraulic chamber 12 is filled with water, and in the ignition chamber 4, the dispersion chamber 3, the guide passage 2 and the combustion chamber 1, a combustible gas having a substantially theoretical mixing ratio is supplied to the fuel supply source. 9, filled with the oxidant supply source 10.

After completion of such setting, the ignition device 6 operates the spark plug 5. A detonation occurs in the ignition chamber 4 due to the ignition, and the flame is propagated to the upper end 1A of the combustion chamber 1 through the dispersion chamber 3 and the guide path 2. At this time, since the path lengths of the plurality of guideways 2 are set to be equal to each other, the flames of the plurality of guideways 2 simultaneously reach the upper end portion 1A.

In the combustion chamber 1, the flame progresses from the upper end portion 1A to the lower end portion 1B, but since the cross-sectional area of the combustion chamber 1 gradually decreases downward, its pressure rises and at the lower end portion 1B. It becomes extremely high pressure.

At the opening of the lower end 1B of the combustion chamber 1, a replaceable nozzle 12 'is set and the liquid surface of the liquid in the hydraulic chamber 12 faces, so that the high pressure causes the liquid to flow from the liquid surface. Then, the plate material P is propagated inward and the plate material P is pressed against the mold 16 at a constant pressure to perform molding.

Thereafter, the plate material as a molded product is taken out, and the above steps (1) to (5) are repeated to obtain
Molding can be performed one after another.

In the present embodiment, molding using a mold is mentioned as a method of utilizing high pressure hydraulic pressure, but it can also be widely used in other fields such as pressurization of other species or a drive source.

In the present invention, the impact pressure can be changed by the filling pressure (amount) or the mixing ratio of the combustible mixed gas to be filled in the combustion chamber, but the generation pattern of the hydraulic pressure can be controlled even in the hydraulic chamber. What can be done is as described above.
For example, by changing the shape and size of the hydraulic chamber (for example, the replacement of the nozzle in the above description) and the physical properties of the liquid, various patterns can be changed to suit the work material. The impact of typical ones of these changing factors will be described in detail below.

(A) Effect of Nozzle Diameter at Opening Due to the nature of the detonation wave in the combustion chamber, the detonation wave repeatedly converges several times, and an impact ultrahigh pressure is generated at the convergence center each time it converges. Since the pressure value at this time shows a higher value as it approaches the convergence center, the smaller the nozzle diameter, the higher the value of the impact pressure generated in the hydraulic chamber can be obtained. Figure 2
FIG. 6 is a diagram showing a hydraulic pressure waveform when the nozzle diameter is relatively small. By setting the nozzle diameter small, the waveform becomes high in peak pressure and short in duration, and high pressure is repeatedly generated several times. On the contrary, when the nozzle diameter is increased, a waveform having a low peak pressure and a long duration is generated as shown in FIG. In this case, the number of pressure wave repetitions is shown in FIG.
Less than

(B) Influence of Distance from Opening to Workpiece When the shock wave propagates in the liquid, the ultimate pressure is a function of the ultimate distance (L in FIG. 1). For example, when the liquid is water, according to a conventional study, the ultimate pressure is inversely proportional to the 1.15th power of the ultimate distance as shown in the following equation.

Pmax ∝1 / L ^1.15 where Pmax is the ultimate pressure and L is the ultimate distance. Therefore, by employing a structure in which the distance of the workpiece from the opening can be arbitrarily changed, it is possible to arbitrarily set the ultimate pressure on the processing surface.

(C) Effect of Physical Properties of Liquid in Hydraulic Chamber The properties of the shock wave obtained on the processed surface in the hydraulic chamber strongly depend on the physical properties of the liquid as a pressure medium. That is, when a liquid having a high density or sound velocity value is used, a peak pressure is high, and a wave having a relatively short duration is obtained. You get long waves.

(D) Influence of Shape of Hydraulic Chamber The shape and size of the impact hydraulic pressure generating portion (which is the nozzle portion in this embodiment) has almost no degree of freedom in the conventional hydraulic pressure generating method. However, the degree of freedom in selecting the pattern of impact hydraulic pressure generation (peak pressure, duration, etc.) is considerably narrowed.

In the case of the present invention, unlike the conventional impact hydraulic pressure generation method, since no bullets, pistons, explosives, etc. are used, the degree of freedom in selecting the shape of the hydraulic chamber is large.

Thus, by adopting the above-mentioned hydraulic chamber shape, the following advantages are obtained.

By setting the hydraulic chamber in a divergent shape and installing a work piece at the end, it is possible to minimize the generation of shock waves not involved in processing (for example, in conventional underwater explosion molding, Since the explosive energy of explosives is dispersed in the 360 ° direction, the energy utilization efficiency is considerably low).

By setting the shape of the hydraulic chamber so that the reflected waves generated on the surface to be processed are gathered at one place, the reflected waves can be regenerated and strengthened and propagated again for processing (disturbed). Even waves can be reproduced as high-intensity waves by collecting them in one place.)

By setting the hydraulic chamber in a conical shape,
It is possible to generate a uniform spherical shock wave.

By additionally providing a cylindrical hydraulic chamber whose thickness can be arbitrarily changed on the downstream side of the conical hydraulic chamber, a shock wave having an arbitrary curvature from a spherical wave to a plane wave can be generated. (In the prior art, only one type of shock wave (hydraulic pressure) generation pattern can be selected with one device).

In the hydraulic chamber, since there is no wall surface perpendicular to the shock wave propagation direction (excluding the processed portion), damage to the hydraulic chamber-related parts due to the shock wave can be suppressed to a small level.

[0059]

Since the present invention is constructed as described above,
Compared with the conventional method, this method is cheaper, more easily obtained with a sharp rise and excellent impact hydraulic pressure, and the shape and size of the hydraulic chamber and the physical properties of the liquid to be stored. By changing the, the effect that the hydraulic pressure can be controlled in various patterns suitable for the workpiece is obtained.

Further, according to the device of the present invention, since the explosive is not used unlike the conventional bullet driving type and explosive type, the device is not restricted in the setting, and the impact hydraulic pressure is continuously generated. The effect of being able to be obtained is obtained.
Further, since the impact hydraulic pressure can be obtained easily and safely, it is possible to make a full-scale application in a wide industrial field such as a processing field.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an apparatus according to an embodiment of the present invention.

FIG. 2 is a hydraulic pressure waveform diagram by one nozzle in the apparatus of FIG.

FIG. 3 is a hydraulic pressure waveform diagram of another nozzle in the apparatus of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustion chamber 1A One end (upper end) 1B The other end (lower end) 2 Taxiway 4 Ignition chamber 5 Spark plug 12 Hydraulic chamber 12 'Nozzle

 ─────────────────────────────────────────────────── --- Continuation of front page (56) References JP-A-4-371327 (JP, A) JP-A-5-57359 (JP, A) JP-A-5-285548 (JP, A) JP-B-57- 17574 (JP, B2)

Claims (6)

(57) [Claims] 1. A liquid containing a liquid in a method of converging a detonation wave generated by igniting a combustible air-fuel mixture as it progresses, and transmitting the high pressure obtained at the converging portion to the liquid to convert it into liquid pressure. A detonation hydraulic pressure generation method characterized in that different patterns of hydraulic pressure are generated by changing the shape and size of the pressure chamber or the physical properties of the liquid. 2. A combustion chamber having a cross-sectional area that decreases from one end to the other end, an ignition chamber in which a spark plug is arranged to receive a fuel supply, and one end of the combustion chamber branching from the ignition chamber and extending. And a hydraulic chamber connected to the opening of the other end which is the minimum cross-sectional area of the combustion chamber, and a replaceable nozzle is installed in the minimum cross-sectional area. The detonation hydraulic pressure generator that is supposed to have been. 3. The detonation hydraulic pressure generating device according to claim 2, wherein the liquid in the hydraulic chamber is in contact with the gas in the combustion chamber through the film body. 4. The detonation hydraulic pressure generator according to claim 2, further comprising drain means for matching the minimum cross-sectional area portion and the liquid surface position. 5. The wall surface downstream from the minimum cross-section area is
The detonation hydraulic pressure generator according to claim 2, wherein the cross-sectional area continuously increases or is constant. 6. The detonation hydraulic pressure generator according to claim 2, wherein the liquid in the hydraulic chamber is in contact with the workpiece through the film body.