JPH0849623A - Liquid atomizer and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a liquid atomizer by which injection pressure is increased, and the ignition quantities and the atomization of spray can be improved. CONSTITUTION:A valve seat 4a provided with a cylindrical part 4b is provided inside an outlet hole 4c of a container 4. A tapered seal valve part 1a is provided on the tip of a vibrating horn 1 to be operated by ultrasonic wave to be generated by a piezoelectric element 2. When the seal valve part 1a is separated from the cylindrical part 4b after the vibrating horn 1 is contracted, liquid fuel 7 is allowed to flow into a space formed between the seal valve part 1a and the valve seat 4a by pressure by a feed pump 6. When the vibrating horn 1 is extended, the liquid fuel 7 is shut in the space formed between the seal valve part 1a and the valve seat 4a. When the vibrating horn 1 is further extended, the seal valve part 1a acts as piston in the process, and the enclosed liquid fuel is pressurized and injected from the outlet hole 4c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid spraying apparatus for supplying a sprayed liquid to a petroleum burner, an automobile engine, etc., which requires a fine sprayed fuel and the like, and a method for producing the same.

[0002]

2. Description of the Related Art An apparatus for supplying atomized fuel to an automobile engine or the like by utilizing ultrasonic vibration is disclosed in, for example, Japanese Patent Laid-Open No. 55-28753. This device has a valve seat that expands toward the inside of the spray port provided in the container. Then, a sealing valve is provided at the tip of the ultrasonic vibration horn that expands the vibration of the ultrasonic vibrator, and the sealing valve contacts the valve seat. Further, the fuel is pressed into the container by the pump. When the ultrasonic oscillator is not vibrating, the sealing valve at the tip of the ultrasonic vibrating horn that receives the spring pressure closes the spray port. When the fuel is sprayed, the ultrasonic vibration horn causes the ultrasonic vibration horn to expand and contract, and the sealing valve moves back and forth in the axial direction of the ultrasonic vibration horn in accordance with the expansion and contraction vibration. As a result, the spray port is intermittently opened, and the fuel press-fitted by the pump is atomized and injected from the spray port.

JP-A-60-22065 and JP-A-6-206
Japanese Patent Laid-Open No. 2-23551 describes a method in which ultrasonic vibration due to flexural vibration of a piezoelectric element is applied to fuel confined in a cavity to inject the fuel in a spray form. In these devices, the pressure of the confined fuel is changed by the flexural vibration of ultrasonic waves to atomize the fuel, thereby reducing the diameter of atomized particles without increasing the pump pressure for injecting the fuel.

[0004]

In the conventional liquid spraying device, the injection pressure depends on the supply pressure of the liquid, that is, the pump pressure for pressing the liquid into the container. Therefore, there is a problem that the amount of jetting and atomization of the spray are not sufficient. For example, when fuel is supplied to an automobile engine, there is a problem that incomplete combustion occurs at low temperatures. Japanese Utility Model Application Laid-Open No. 63-54916 describes a device similar to the above device, but even in that device, only the supply pressure of the liquid is used as the injection pressure. In the case of an automobile engine, it is desirable to inject the fuel at a high pressure of 10 MPa or more, but it is difficult to achieve it only by the pump pressure. It is possible to increase the pump pressure for liquid injection in order to increase the injection pressure, but doing so causes the following problems and is actually difficult. That is, when the pump pressure is increased, or when the path from the pump to the container is damaged, the high pressure causes the fuel to scatter in a wide range in the engine compartment, which leads to a catastrophic disaster with highly flammable gasoline. Further, in the case of liquid with low viscosity such as gasoline, unlike diesel fuel, lubrication of the piston and cylinder is insufficient, and it is difficult to raise the pressure with the pump. Furthermore, a large amount of driving energy is required to increase the pump pressure, which results in poor fuel efficiency and is not suitable for use in automobiles. In Japanese Patent Application Laid-Open No. 60-22065 and Japanese Patent Application Laid-Open No. 62-23551,
Although liquid is ejected using pressure fluctuation based on ultrasonic vibration due to flexural vibration of the piezoelectric element, flexural vibration has a lower rigidity than expansion and contraction motion, and therefore its generating force is weak. Therefore, it is difficult to inject fuel at a high pressure of 10 MPa or higher, which is desirable in an automobile engine or the like, only by the pressure fluctuation.

The present invention has been made to solve such a problem, and the ejection pressure can be increased without increasing the liquid supply pressure, and the ejection amount and atomization of the atomization can be further improved. An object is to provide a liquid spraying device and a method for manufacturing the device.

[0006]

A liquid spraying device according to a first aspect of the present invention has an outlet hole communicating with the outside, and a valve seat having a recess around the outlet hole is provided on the inner surface. And a sealing valve that has a peripheral portion that fits in the recess and abuts the valve seat, and a resonator that gives the sealing valve a back-and-forth movement for exiting the recess.

In the liquid spraying device according to the second aspect of the present invention, the protrusion protruding in the expansion / contraction direction is provided in the peripheral portion of the sealing valve, and the container is provided with a hole that fits the protrusion.

In the liquid spraying apparatus according to the third aspect of the present invention, the resonator has a positioning means that comes into contact with the inner peripheral surface of the container.

The liquid spraying device according to the fourth aspect of the present invention is further provided with an inclined surface in which the gap between the valve and the sealing valve gradually increases from the valve seat toward the outlet hole.

In the liquid spraying device according to the fifth aspect of the present invention, a check valve is further provided outside the outlet hole.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a liquid spraying device, wherein a vibrating means drives a resonator of the liquid spraying device to form a recess while introducing a liquid containing abrasive particles into a container. There is a step of doing.

[0012]

In the invention described in claim 1, when the sealing valve is opened by the resonator, the liquid is introduced into the space formed between the sealing valve and the recess of the valve seat. When the sealing valve closes, the valve action of the sealing valve seals the liquid in the space, and high pressure is applied by the piston action to eject the liquid from the outlet hole. In the invention of claim 2, the protrusion provided on the peripheral portion of the sealing valve positions the sealing valve and the recess. In the invention of claim 3, the positioning means positions the central axis of the resonator, and as a result, the sealing valve is reliably positioned in the recess. In the invention of claim 4, the inclined surface provided from the valve seat toward the outlet hole efficiently guides the liquid trapped between the sealing valve and the recess to the outlet hole. In the invention of claim 5, the check valve prevents the liquid from flowing back into the container through the outlet hole. According to the sixth aspect of the invention, according to the step of driving the resonator to form the cylindrical portion while introducing the liquid containing the abrasive particles into the container, the actually used sealing valve forms the concave portion in the valve seat. As a result, it is possible to form a recess that exactly fits the sealing valve.

[0013]

【Example】

Example 1. 1 is a sectional view showing a liquid spraying device according to a first embodiment of the present invention. As shown in the drawing, an outlet hole 4c is provided at the center of one end of the container 4, and a valve seat 4a that widens toward the inside of the container 4 is provided inside the outlet hole 4c. Further, a cylindrical portion 4b having a depth of about 30 μm is provided around the valve seat 4a. In the container 4, for example, 10
A metallic vibrating horn 1 is installed which resonates in the axial direction in the ultrasonic region of kHz or higher. The vibrating horn 1 has, for example, a tapered cylindrical shape, and a tapered sealing valve portion 1a is provided at a thin tip thereof. At the other end of the container 4, the vibrating horn 1 is fixed to the container 4 by a thin flange portion 1b provided at a position corresponding to a node of vibration at the time of resonance. The sealing valve portion 1a is provided with a certain sealing force by the deflection of the flange portion 1b while being in contact with the valve seat 4a through the tubular portion 4b. The sealing valve portion 1a and the tubular portion 4b are formed so that a slight gap is formed between the sealing valve portion 1a and the tubular portion 4b. The piezoelectric element 2 is fixed to the thick end of the vibrating horn 1. An alternating voltage having the same frequency as the resonance frequency of the vibrating horn 1 is applied to the piezoelectric element 2 from the oscillator 3. The liquid fuel 7 is supplied to the container 4 through the pipe 5 by the supply pump 6 at a low pressure of about 200 kPa.
The atmospheric pressure is about 100 kPa. Also, container 4
The vibration horn 1 is sealed with a rubber seal 8.

Next, the operation will be described. When the oscillator 3 does not generate an AC voltage, the sealing valve portion 1a is in contact with the valve seat 4a by the spring force of the flange portion 1b. Therefore, the liquid fuel 7 does not leak out through the outlet hole 4c.

At the time of injecting fuel, the oscillator 3 is driven, and an AC voltage is supplied from the oscillator 3 to the piezoelectric element 2. Then, the piezoelectric element 2 expands and contracts in the axial direction of the vibrating horn 1 with an amplitude of about 5 μm at maximum, which is proportional to the magnitude of the AC voltage. This expansion and contraction is transmitted to the vibration horn 1. The vibrating horn 1 increases the stretching vibration about 20 times by resonance and causes the sealing valve portion 1a to move back and forth in the axial direction with an amplitude of about 100 μm. As shown in FIG. 2A, when the vibrating horn 1 contracts and the sealing valve portion 1a separates from the cylinder portion 4b, the liquid fuel 7 is pressurized by the supply pump 6 and the sealing valve portion 1a and the valve seat 4a. Flows into the space formed between. Next, as shown in FIG. 2B, when the vibration horn 1 extends until the sealing valve portion 1a closes the tubular portion 4b, the liquid fuel 7 is discharged between the sealing valve portion 1a and the valve seat 4a. The liquid fuel 7a is enclosed in the formed space. As shown in FIG. 2 (c),
When the vibration horn 1 further extends, the sealing valve portion 1a acts as a piston in the process, and the confined liquid fuel 7a is pressurized and injected from the outlet hole 4c. The above operation is repeated according to the frequency of the alternating voltage.

As described above, since the cylindrical portion 4b that fits into the sealing valve portion 1a is provided around the valve seat 4a, the liquid fuel 7a can be trapped and the sealing valve portion 1a can act as a piston. Therefore, the injection pressure of the liquid fuel can be increased. Further, since the vibrating horn 1 is a metal lump, it has high rigidity and can perform stretching vibration that transmits high stress against the repulsive force due to the compression of the liquid fuel 7a. The cross-sectional area of the sealing valve portion 1a that performs the piston action may be small, and as a result, the pressure applied to the liquid fuel 7a can be increased to several tens MPa or higher. The higher the injection pressure, the smaller the particle size of the spray sprayed, so that a finer spray can be obtained. In addition, since the inertial force of the vibrating horn 1 transmitting the impact force to the liquid fuel 7a at the moment when the sealing valve portion 1a moving in the high-speed ultrasonic region fits into the cylindrical portion 4b, a steep pressure rise can be obtained. You can This steep pressure rise enables finer atomization. Further, since the degree of expansion and contraction of the sealing valve portion 1a is small, the ejection amount per one time is small, but since the expansion and contraction is repeated at a frequency of about 10 kHz or more, the ejection amount per time can be sufficiently increased. As in the conventional case, the ejection amount proportional to the period of applying the AC voltage is obtained. Since the sealing valve unit 1a moves at a high speed, the liquid fuel 7a is discharged from the sealing valve unit 1a.
There is no leakage due to the pressure of the supply pump 6 before being pressurized by a. That is, the liquid fuel 7a is injected almost only by the piston action of the sealing valve portion 1a.
Further, the enclosed liquid fuel 7a acts as a cushion and absorbs the impact, so that the sealing valve portion 1a and the valve seat 4 are
The degree of collision of a becomes gentler, and the sealing valve portion 1a and the valve seat 4
The service life due to abrasion of a does not matter.

FIG. 3 is an explanatory view showing a method of manufacturing the cylinder portion 4b and the valve seat 4a, which are the main constituent elements of the liquid spraying device according to the first embodiment. This manufacturing method is a method similar to the ultrasonic processing method in precision processing. As shown in the figure, the bottom surface 4d of the container 4 in which the tubular portion 4b is not formed
Then, the sealing valve portion 1a is brought into contact with the flange 1b by the spring force. The sealing valve portion 1a is made of a material harder than the material of the bottom surface 4d. Next, the vibrating horn 1 may be driven while injecting the polishing liquid 9 containing polishing particles. Then, the sealing valve portion 1a strikes the abrasive particles on the bottom surface 4d and scrapes off the bottom surface 4d. The shavings are discharged from the outlet hole 4c together with the polishing liquid 9. According to such a manufacturing method, the cylindrical portion 4b slightly larger than the fine sealing valve portion 1a and having a minute dimension of about 30 μm is used as the sealing valve portion 1 which is actually used.
It can be manufactured according to a.

Example 2. FIG. 4 is a sectional view showing a main part of a liquid spraying device according to a second embodiment of the present invention, and FIG. 5 is a bottom view of the sealing valve part 1a of the vibrating horn 1 as seen from the bottom. In this liquid spraying device, three protrusions 10 extending in the axial direction are provided at the peripheral edge of the sealing valve portion 1a. Each protrusion 1
0 means 1 on the cross section of the sealing valve portion 1a when the cross section is circular.
It is provided at intervals of 20 °. Even when the cross section of the sealing valve portion 1a has another shape, the protrusions 10 are provided at equal intervals. Further, the valve seat 4a is formed with a hole 11 that fits into the protrusions 10. Sealing valve section 1a
The length of the projecting portion 10 is set such that the tip of the projecting portion 10 contacts the cylindrical portion 4b even when the vibrating horn 1 is contracted most.

The basic operation in this case is similar to that of the first embodiment, but in this case, even when the vibrating horn 1 is contracted and the sealing valve portion 1a is separated from the cylindrical portion 4b, the protrusion is formed. The side surface of the portion 10 does not separate from the tubular portion 4b. In addition, the sealing valve unit 1
In the process in which the vibrating horn 1 extends until a blocks the cylindrical portion 4b, the protrusion 10 moves in the hole 11 along the inner surface on the side of the cylindrical portion 4b.

That is, since the side surface of the protruding portion 10 is not separated from the cylindrical portion 4b, the sealing valve portion 1a is surely secured to the cylindrical portion 4b.
Guided by b. In addition, in order to form the valve seat 4a provided with such a hole 11, a manufacturing method similar to the ultrasonic processing method as shown in FIG. 3 is particularly effective.

Example 3. 6 is a sectional view showing a main part of a liquid spraying device according to a third embodiment of the present invention, and FIG. 7 is a sectional view including a guide portion 12 of a vibrating horn 1. In this case, the outer peripheral edge of the side surface of the vibrating horn 1 is the inner peripheral surface 4e of the container 4.
Is provided with three guide portions 12. In addition, in reality, a minute gap is provided between the guide portion 12 and the inner peripheral surface 4e. When the vibrating horn 1 has a circular cross section, the guide portions 12 are provided at intervals of 120 ° on the cross section. Even when the cross section of the vibrating horn 1 has other shapes, the guide portions 12 are provided at equal intervals.
Both sides in the axial direction of the guide portion 12 are inclined portions 12a.

The basic operation in this case is similar to that of the first embodiment, but in this case, when the vibrating horn 1 expands and contracts, the guide portion 12 moves along the inner peripheral surface 4e of the container 4. Moving. By providing such a guide portion 12, the central axis of the vibrating horn 1 is accurately positioned, and as a result, the sealing valve portion 1a surely returns to the tubular portion 4b. Also,
At the time of expansion and contraction, the inclined portion 12a of the guide portion 12 causes the liquid fuel 7 to move while being caught between the inner peripheral surface 4e of the container 4 and the guide portion 12. Therefore, the friction between the inner peripheral surface 4e and the guide portion 12 is small, and the presence of the guide portion 12 does not hinder the expansion and contraction movement. Further, the wear of the inner peripheral surface 4e and the guide portion 12 does not pose a problem.

Embodiment 4 FIG. FIG. 8 is a sectional view showing a main part of a liquid spraying device according to a fourth embodiment of the present invention. In this liquid spraying device, the valve seat 13 is further formed with a lead-out portion 14 that is cut out in an annular shape. The lead-out portion 14 is formed so that the gap between the lead-out portion 14 and the sealing valve portion 1a becomes larger toward the outlet hole 4c.

The basic operation in this case is similar to that of the first embodiment, but when the sealing valve portion 1a is extended,
The liquid fuel 7a trapped between the sealing valve portion 1a and the valve seat 4a is pushed out to the side closer to the outlet hole 4c of the lead-out portion 14 where the gap between the sealing valve portion 1a and the sealing valve portion 1a is larger. Therefore, the trapped liquid fuel 7a is ejected from the outlet hole 4c with less resistance. In addition, in the liquid spraying device partially shown in FIG. 8, it is possible to provide the protrusion 10 as in the second embodiment or the guide 12 as in the third embodiment. In addition, such a tubular portion 4
b to form the valve seat 13 with the lead-out 14
A manufacturing method similar to the ultrasonic processing method shown in FIG. 3 is particularly effective. In that case, in order to form the lead-out portion 14 as shown in FIG. 8, the inclination angle of the bottom surface portion 4d of the container 4 may be made larger than the inclination angle of the sealing valve portion 1a.

Embodiment 5 FIG. FIG. 9 is a sectional view showing a main part of a liquid spraying device according to a fifth embodiment of the present invention, and FIG. 10 is a bottom view of the container 4 as seen from the bottom. In this case, the outer peripheral edge of the flat check valve 15 having a check valve effect is fixed to the outer bottom surface of the container 4 of the liquid spraying device by welding or the like. The check valve 15 includes, for example, three spray holes 16
Are opened, but their positions are deviated from the positions of the outlet holes 17.

The basic operation in this case is similar to that of the first embodiment. When the vibration horn 1 contracts and the sealing valve portion 1a separates from the tubular portion 4b, the pressure in the portion between the sealing valve portion 1a and the valve seat 4a becomes the same as the pressure of the supply pump 6. However, at this time, the pressure outside the spray holes 16 may be higher than this pressure. Even in such a case, the check valve 15 prevents the backflow of fuel. When the sealing valve portion 1a pressurizes the liquid fuel 7a and its pressure becomes higher than the pressure outside the spray hole 16,
The check valve 15 opens downward due to the deflection, and the fuel is injected through the outlet hole 17 and the spray hole 16.
Such a check valve 15 is effective when the fuel is sprayed into a high pressure cylinder of about 10 MPa or more, such as a diesel engine. In addition, in the liquid spraying device partially shown in FIG. 9, it is possible to provide the protrusion 10 as in the second embodiment or the guide 12 as in the third embodiment. Further, the lead-out portion 14 as in the fourth embodiment may be formed.

In each of the above-described embodiments, the case of injecting fuel into the engine has been described, but each liquid spraying device is also applicable to the case where fuel injection is required other than the engine such as a petroleum burner. Further, it is of course applicable to the application of spraying liquid other than fuel. In addition, in order to increase the spray amount, the amplitude of the vibrating horn 1 may be increased. For that purpose, for example, the vibrating horn may be made long and the resonance frequency may be set to 10 kHz or lower, which is lower than the ultrasonic range.

[0028]

As described above, according to the first aspect of the invention, the liquid spraying device has a container provided with a valve seat having a recess and a peripheral portion that fits in the recess and contacts the valve seat. With the configuration including the sealing valve, the injection pressure of the liquid fuel can be increased by the piston action of the sealing valve. At the same time, a finer spray is obtained.

According to the second aspect of the present invention, since the liquid spraying device has the structure in which the projection protruding in the expansion / contraction direction is provided in the peripheral portion of the sealing valve, the sealing valve is surely formed in the concave portion. There is a fitting effect.

According to the third aspect of the invention, since the liquid spraying device is provided with the positioning means for contacting the inner peripheral surface of the container on the side surface of the resonator, the center axis of the resonator is accurate. The positioning of the sealing valve has the effect of reliably fitting the sealing valve in the recess.

According to the invention described in claim 4, the liquid spraying device is further provided with an inclined surface in which the gap between the valve seat and the sealing valve gradually increases from the outlet hole. Therefore, in addition to the above effects, there is an effect that the liquid trapped between the sealing valve and the recess can be efficiently guided to the outlet hole and the liquid can be efficiently sprayed.

According to the fifth aspect of the invention, the liquid spraying device is further provided with a check valve outside the outlet hole. Therefore, in addition to the above effects, This has the effect of reliably preventing the liquid from flowing back into the container.

According to the sixth aspect of the present invention, in the method for manufacturing a liquid spraying device, the resonator used in the liquid spraying device is driven while introducing the liquid containing abrasive particles into the container to form the cylindrical portion. The sealing valve actually used forms a recess in the valve seat, which has the effect of forming a recess that exactly fits in the sealing valve.

[Brief description of drawings]

FIG. 1 is a sectional view showing a liquid spraying device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining the operation of the sealing valve portion and the tubular portion.

FIG. 3 is an explanatory diagram for explaining a method of manufacturing a liquid spray device.

FIG. 4 is a sectional view showing a main part of a liquid spraying device according to a second embodiment of the present invention.

5 is a bottom view of the vibrating horn shown in FIG. 4 as viewed from the bottom.

FIG. 6 is a cross-sectional view showing the main parts of a liquid spraying device according to a third embodiment of the present invention.

7 is a sectional view including a guide portion of the vibrating horn shown in FIG.

FIG. 8 is a sectional view showing a main part of a liquid spraying device according to a fourth embodiment of the present invention.

FIG. 9 is a cross-sectional view showing the main parts of a liquid spraying device according to a fifth embodiment of the present invention.

FIG. 10 is a bottom view of the container shown in FIG. 9 seen from the bottom.

[Explanation of symbols]

1 Vibrating horn, 1a Sealing valve part, 2 Piezoelectric element, 3
Oscillator, 4 Container, 4a Valve seat, 4b Cylindrical part, 4c Exit hole, 10 Projection part, 12 Guide part, 14 Lead-out part, 1
5 check valves.

Claims (6)

[Claims] 1. A container for storing a liquid, the container having an outlet hole communicating with the outside, the valve seat having a concave portion around the inlet of the outlet hole provided on the inner surface, and the container fitted in the concave portion. A sealing valve having a surrounding portion that abuts against the valve seat, a resonator that performs expansion and contraction motion that gives the sealing valve a back-and-forth movement that moves out of the recess, and a vibration that has a resonance frequency of the resonator. A liquid spraying device comprising a shaking means. 2. The liquid spraying device according to claim 1, wherein a protrusion protruding in the expansion and contraction direction is provided in a peripheral portion of the sealing valve, and a hole which is fitted in the protrusion is provided in the container. 3. The liquid spraying apparatus according to claim 1, wherein the resonator has a positioning means on its side surface that is in contact with the inner peripheral surface of the container. 4. An inclined surface provided with a gradual increase in the gap between the valve seat and the sealing valve toward the outlet hole.
Liquid spraying device as described. 5. The liquid spraying device according to claim 1, further comprising a check valve provided outside the outlet hole. 6. A method for manufacturing a liquid spraying device according to claim 1, wherein the vibrating means drives the resonator of the liquid spraying device while introducing the liquid containing abrasive particles into the container. Of manufacturing a liquid spraying device for forming a liquid.