Liquid spraying device

Abstract

To enable skin, fiber and metal or the like to be effectively washed.SOLUTION: A liquid jet device comprises: a jet nozzle 11 having at least one nozzle hole 1 that jets liquid; a pressurized liquid supply part 27 that pressurizes liquid and then feeds the liquid to the jet nozzle; and a control part 4 that controls motion of the pressurized liquid supply part, so that liquid jetted through the nozzle hole is splashed while being scattered from continuous flow into droplets, where a pore diameter of the nozzle hole 1 is 0.015 mm-0.030 mm and viscosity of the liquid is 0.6 mPa.s-4.0 mPa.s. The control part controls supply pressure of the pressurized liquid supply part so that speeds of the liquid jetted from the nozzle hole 1 are 10 m / s-80 m / s and the number of droplets (droplet / s) per second of the droplets generated resulting from the scattering from the continuous flow is in a range of 0.8×105-9.0×105.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device suitable for ejecting liquid onto a target object such as the face or other skin, or fabric or metal, for cleaning or other treatment. [Background technology]

[0002] One example of this type of liquid spray device is the skin cleanser described in Patent Document 1. This document discloses a skin cleanser that has a cup with an opening facing outward at the tip of the handle, and that is used by applying a spray part that sprays water pumped through a pump outlet into a mist and toward the opening through the inside of the cup to the skin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 61-103443 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the skin cleaner in the above document has the problem that, because the sprayed water is atomized and directed at the skin, it is difficult to obtain sufficient pressure, making it difficult to effectively cleanse the skin, particularly the sebum and dirt that comes from the sebaceous glands. There is no mention of spraying a liquid onto an object such as a fabric or metal to perform cleaning or other treatment. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, a liquid ejection device according to the present invention is a liquid ejection device comprising: an ejection nozzle having at least one nozzle hole for ejecting liquid; a pressurized liquid supply unit that pressurizes the liquid and sends it to the ejection nozzle; and a control unit that controls the operation of the pressurized liquid supply unit to cause the liquid ejected from the nozzle hole to fly in a state in which the liquid is split into droplets from a continuous stream, wherein the nozzle hole has a diameter of 0.015 mm to 0.030 mm, and the liquid has a viscosity of 0.6 mPa·s to 4.0 mPa·s, and the control unit controls the liquid ejected from the nozzle hole to fly in a state in which the velocity of the liquid is 10 m / s to 80 m / s, and the number of droplets (droplets / s), which is the number of droplets per second generated by splitting the continuous stream into droplets, is 0.8×10 5 ~9.0×10 5 The supply pressure of the pressurized liquid supply unit is controlled so as to be in the range of

[0006] In order to solve the above-mentioned problems, the present invention provides a liquid ejection device comprising: an ejection nozzle having at least one nozzle hole for ejecting liquid; a pressurized liquid supply unit that pressurizes the liquid and sends it to the ejection nozzle; and a control unit that controls the operation of the pressurized liquid supply unit to cause the liquid ejected from the nozzle hole to fly in a state in which the liquid is split into droplets from a continuous stream, wherein the nozzle hole has a diameter of 0.05 mm to 0.12 mm, and the liquid has a viscosity of 0.6 mPa·s to 4.0 mPa·s, and the control unit controls the liquid ejected from the nozzle hole to fly in a state in which the velocity of the liquid is 10 m / s to 70 m / s, and the number of droplets (droplets / s), which is the number of droplets per second generated by splitting the continuous stream into droplets, is 0.3×10 5 ~4.0×10 5 The supply pressure of the pressurized liquid supply unit is controlled so as to be in the range of [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram illustrating the overall configuration of a liquid ejecting apparatus according to a first embodiment of the present invention. [Figure 2]10A and 10B are high-speed photographs of the continuous flow and droplet movement when the liquid supply pressure is 0.4 MPa and 1.3 MPa in the first embodiment. [Figure 3] (A) is a high-speed image of the continuous flow at the outlet of the nozzle hole, taken with the upper edge of the photographic field aligned with the edge of the component housing the injection nozzle. (B) is a high-speed image of a part in the process of transitioning to droplet formation, where the continuous flow and droplets are mixed together. (C) is a high-speed image of a part in the state where the continuous flow has completely split into droplets. [Figure 4] FIG. 10 is a high-speed photographic image used to explain how to calculate droplet velocity. [Figure 5] FIG. 1 is a high-speed photographic image used to explain how to determine the droplet frequency. [Figure 6] FIG. 1 shows the relationship between the actual measured droplet frequency values ​​(actual droplet frequency) and the calculated values ​​(calculated droplet frequency) obtained by performing regression analysis on the actual measured values ​​for Liquids A to X in Table 1 and pure water at 20°C and 40°C in a nozzle hole with a hole diameter of 0.015 mm. [Figure 7] FIG. 1 shows the relationship between the actual measured droplet frequency values ​​(actual droplet frequency) and the calculated values ​​(calculated droplet frequency) obtained by performing regression analysis on the actual measured values ​​for liquids A to Y in Table 1 and pure water at 20°C in a nozzle hole with a hole diameter of 0.024 mm. [Figure 8] FIG. 1 shows the relationship between the actual measured droplet frequency values ​​(actual droplet frequency) and the calculated values ​​(calculated droplet frequency) obtained by performing regression analysis on the actual measured values ​​for liquids A to E in Table 1 and pure water at 20°C in a nozzle hole with a hole diameter of 0.03 mm. [Figure 9] 1 is a graph showing the relationship between the measured droplet frequency and the calculated droplet frequency for each pore size shown in the graph for liquid X, liquid Y, pure water at 20°C, and pure water at 40°C in Table 1. [Figure 10] This is a graph showing the relationship between the actually measured droplet frequency and the calculated value / actual value for liquids A to X in Table 1 and pure water at 20°C and pure water at 40°C in a nozzle hole with a hole diameter of 0.015 mm. [Figure 11] 1 is a graph showing the relationship between the measured droplet frequency and the calculated value / measured value for liquids A to D in Table 1 in a nozzle hole with a hole diameter of 0.024 mm. [Figure 12] This is a graph showing the relationship between the measured droplet frequency and the calculated value / measured value for liquids A to E in Table 1 and pure water at 20°C in a nozzle hole with a hole diameter of 0.03 mm. [Figure 13] FIG. 10 shows the relationship between the actual measured values ​​(actual droplet frequencies) obtained by measuring the droplet frequency and the calculated values ​​(calculated droplet frequencies) obtained by performing regression analysis on the actual measured values ​​for liquids F to I in Table 7 and pure water at 20°C for a nozzle hole with a diameter of 0.05 mm. [Figure 14] FIG. 10 shows the relationship between the actual measured values ​​(actual droplet frequencies) obtained by measuring the droplet frequency and the calculated values ​​(calculated droplet frequencies) obtained by performing regression analysis on the actual measured values ​​for liquids F to I in Table 7 and pure water at 20°C for a nozzle hole with a diameter of 0.08 mm. [Figure 15] FIG. 10 shows the relationship between the actual measured values ​​(actual droplet frequencies) obtained by measuring the droplet frequency and the calculated values ​​(calculated droplet frequencies) obtained by performing regression analysis on the actual measured values ​​for liquids F to I in Table 7 and pure water at 20°C for a nozzle hole with a hole diameter of 0.12 mm. [Figure 16] 1 is a graph showing the relationship between the measured droplet frequency and the calculated droplet frequency for each pore size shown in the graph for pure water at 40°C and liquid Z in Table 7. [Figure 17] This figure shows the relationship between the measured droplet frequency and the calculated value / measured value for liquids F to I in Table 7, pure water at 20°C, pure water at 40°C, and liquid Z for a nozzle hole with a hole diameter of 0.05 mm. [Figure 18] This figure shows the relationship between the measured droplet frequency and the calculated value / measured value for liquids F to I in Table 7 and pure water at 20°C and 40°C for a nozzle hole with a hole diameter of 0.08 mm. [Figure 19] This figure shows the relationship between the measured droplet frequency and the calculated value / measured value for liquids F to I in Table 7 and pure water at 20°C and 40°C for a nozzle hole with a hole diameter of 0.12 mm. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present invention will now be briefly described. In order to solve the above-mentioned problems, a first aspect of the liquid ejection device according to the present invention is a liquid ejection device comprising: an ejection nozzle having at least one nozzle hole for ejecting liquid; a pressurized liquid supply unit that pressurizes the liquid and sends it to the ejection nozzle; and a control unit that controls the operation of the pressurized liquid supply unit to cause the liquid ejected from the nozzle hole to fly in a state in which the liquid is split into droplets from a continuous stream, wherein the nozzle hole has a diameter of 0.015 mm to 0.030 mm, and the liquid has a viscosity of 0.6 mPa·s to 4.0 mPa·s, and the control unit controls the liquid ejected from the nozzle hole to fly in a state in which the velocity of the liquid ejected from the nozzle hole is 10 m / s to 80 m / s, and the number of droplets (droplets / s), which is the number of droplets per second generated by splitting the continuous stream into droplets, is 0.8×10 5 ~9.0×10 5 The supply pressure of the pressurized liquid supply unit is controlled so as to be in the range of In the following description, the number of droplets (droplets / s), which is the number of droplets generated per second by splitting the continuous stream into droplets, may be referred to as the "droplet frequency."

[0009] In the liquid injection device of the present invention, the control unit controls the supply pressure of the pressurized liquid supply unit, so that liquid is injected as a continuous stream from the nozzle hole of the injection nozzle, and then the continuous stream splits as it flies to generate droplets. It is known that the size of the droplets thus generated has a fixed relationship with the nozzle hole diameter b based on the linear theory of non-viscosity. That is, it is known that the size of the droplets is approximately 1.88 times the nozzle hole diameter b, regardless of the magnitude of the supply pressure, based on the linear theory of non-viscosity. If the nozzle hole diameter is 0.015 mm to 0.030 mm, this works out to 0.0282 mm to 0.0564 mm. Furthermore, taking into consideration that there will be some variation depending on the smoothness of the nozzle hole and environmental conditions, the droplet size will be approximately 0.03 mm to 0.1 mm as an average droplet diameter. Next, the ejection speed of the liquid ejected from the nozzle hole can be set by adjusting the supply pressure for the nozzle hole with the specified hole diameter of 0.015 mm to 0.030 mm. Once the ejection speed of the liquid is determined to be in the range of 10 m / s to 80 m / s, the speed of the flying droplets is also determined. The droplet speed is approximately the same as the ejection speed, so it is in the range of 10 m / s to 80 m / s. Furthermore, as the liquid ejection speed increases, the flow rate (ml / min) of the liquid ejected from the nozzle hole also increases. The liquid ejection speed increases as the supply pressure is increased, and decreases as the supply pressure is decreased. Therefore, the liquid flow rate (ml / min) increases as the supply pressure increases, since the ejection speed increases, and decreases as the supply pressure decreases, since the ejection speed decreases. In other words, the "liquid flow rate (ml / min)" can be set by adjusting the supply pressure for the nozzle hole with the specified hole diameter of 0.015 mm to 0.030 mm. Once the "liquid flow rate (ml / min)" is determined, the number of droplets (droplets / s), which is the number of droplets generated per second when the continuous flow splits into droplets, can be easily calculated by dividing the "liquid flow rate (ml / min)" by the "droplet size," since the "droplet size" generated corresponds to the hole diameter of 0.015 mm to 0.030 mm, as described above. In other words, once the "liquid flow rate (ml / min)" is determined, the "number of droplets (droplets / s)," i.e., the "droplet frequency," is also determined. If the number of injection nozzle holes is more than one, the "liquid flow rate (ml / min)" is multiplied by the number of holes. This also applies to the following explanation.

[0010] As can be understood from the above description, in the liquid ejecting device according to the present invention, for nozzle holes with a diameter in the range of 0.015 mm to 0.030 mm, by adjusting the supply pressure of the pressurized liquid supply unit, the liquid ejection speed falls within the range of 10 m / s to 80 m / s, and the droplet frequency falls within the range of 0.8 × 10 5 ~9.0×10 5 It is possible to set it to be in the range of That is, a liquid with a viscosity of 0.6 mPa·s to 4.0 mPa·s is sprayed at a velocity in the range of 10 m / s to 80 m / s, and the droplet frequency is 0.8×10 5 ~9.0×10 5 The droplets can be repeatedly applied to an object such as skin as flying droplets in a range of .

[0011] As can be understood from the above explanation, according to this aspect, for a nozzle hole diameter in the range of 0.015 mm to 0.030 mm, a liquid having a viscosity within the range can be used, and the number of droplets (droplets / s) generated from this liquid can be propelled at the speed and hit an object such as skin one after another. This allows for effective cleaning of the object such as skin. Furthermore, since droplets collide with the skin at such an ultrasound-like droplet frequency, i.e., at a droplet number (droplets / s), physical stimulation can be applied to the skin, which is expected to improve skin condition such as moisturizing and elasticity, i.e., skin care. The inventors have confirmed, as will be described below, that skin can be effectively cleansed by causing droplets generated from a liquid with the above viscosity and surface tension to fly at the above speed and number of droplets (droplets / s) and hit the skin.

[0012] A second aspect of the present invention is a liquid ejecting device according to the first aspect, wherein the liquid has a viscosity of 0.65 mPa·s to 3.3 mPa·s, the velocity of the liquid ejected from the nozzle hole is in the range of 19 m / s to 63 m / s, and the number of droplets (droplets / s) is 1.3×10 5 ~7.1×10 5 is characterized in that it is in the range of

[0013] According to this aspect, the liquid has a viscosity of 0.65 mPa·s to 3.3 mPa·s, the velocity of the liquid ejected from the nozzle hole is in the range of 19 m / s to 63 m / s, and the number of droplets (droplets / s) is 1.3×10 5 ~7.1×10 5 This makes it possible to obtain the effect of the first aspect more effectively.

[0014] A third aspect of the present invention is the liquid ejecting device of the first or second aspect, characterized in that the droplet breakup distance over which the continuous stream breaks up into droplets is within 20 mm. Here, the term "dropletizing distance" refers to the distance over which a continuous flow ejected from the end face of the ejection nozzle on the side ejecting the liquid breaks up into droplets.

[0015] The droplet generation distance increases as the supply pressure increases, and decreases as the supply pressure decreases. By adjusting the supply pressure, the droplet generation distance can be kept within 20 mm. According to this aspect, the droplet formation distance is set to 20 mm or less, which makes it easier to apply the droplets to the targeted area of ​​the target object such as the skin.

[0016] A fourth aspect of the liquid ejection device according to the present invention is a liquid ejection device comprising: an ejection nozzle having at least one nozzle hole for ejecting liquid; a pressurized liquid supply unit that pressurizes the liquid and sends it to the ejection nozzle; and a control unit that controls the operation of the pressurized liquid supply unit to cause the liquid ejected from the nozzle hole to fly in a state in which the liquid is split into droplets from a continuous stream, wherein the nozzle hole has a diameter of 0.05 mm to 0.12 mm, and the liquid has a viscosity of 0.6 mPa·s to 4.0 mPa·s, and the control unit controls the liquid ejected from the nozzle hole to fly in a state in which the velocity of the liquid ejected from the nozzle hole is 10 m / s to 70 m / s, and the number of droplets (droplets / s), which is the number of droplets per second generated by splitting the continuous stream into droplets, is 0.3×10 5 ~4.0×10 5 The supply pressure of the pressurized liquid supply unit is controlled so as to be in the range of

[0017] As can be understood from the above description of the first aspect, in the liquid ejecting device according to the present invention, for nozzle holes with a diameter in the range of 0.05 mm to 0.12 mm, by adjusting the supply pressure of the pressurized liquid supply unit, the liquid ejection speed falls within the range of 10 m / s to 70 m / s, and the droplet frequency falls within the range of 0.3 × 10 5 ~4.0×10 5It is possible to set it to be in the range of That is, a liquid with a viscosity of 0.6 mPa·s to 4.0 mPa·s is sprayed at a velocity in the range of 10 m / s to 70 m / s, and the droplet frequency is 0.3×10 5 ~4.0×10 5 The droplets fly over a range of 100m and can be repeatedly applied to objects such as skin, fabric, and metal.

[0018] As can be understood from the above explanation, according to this aspect, it is possible to use a liquid having a viscosity within the above range for a nozzle hole diameter in the range of 0.05 mm to 0.12 mm, and to generate the above number of droplets (droplets / s) from this liquid by causing them to fly at the above speed and hit an object such as skin, fabric, metal, etc. in succession, thereby enabling effective cleaning and other treatments to be performed on the object. Furthermore, because droplets collide with the skin at such an ultrasonic droplet frequency, i.e., at a droplet number (number / s), a physical stimulus can be applied to the skin, which is expected to improve skin condition such as moisturizing and elasticity, i.e., skin care.For fibers and metals, it is expected to be effective in softening or destroying and removing dirt and foreign matter attached to the surface or inside of the substrate without damaging the substrate. The inventors have confirmed, as will be described later, that by flying droplets generated from a liquid with the above viscosity and surface tension at the above speed and number of droplets (droplets / s) and hitting the object, it is possible to effectively perform appropriate cleaning and other treatments on the object.

[0019] A fifth aspect of the present invention is a liquid ejecting device according to the first aspect, wherein the liquid has a viscosity of 0.65 mPa·s to 3.3 mPa·s, the velocity of the liquid ejected from the nozzle hole is in the range of 14 m / s to 52 m / s, and the number of droplets (droplets / s) is 0.5×10 5 ~2.4×10 5 is characterized in that it is in the range of

[0020] According to this aspect, the liquid has a viscosity of 0.65 mPa·s to 3.3 mPa·s, the velocity of the liquid ejected from the nozzle hole is in the range of 14 m / s to 52 m / s, and the number of droplets (droplets / s) is 0.5×10 5 ~2.4×10 5 This makes it possible to obtain the effect of the first aspect more effectively.

[0021] A sixth aspect of the present invention is the liquid ejecting device according to the fourth or fifth aspect, characterized in that the dropletization distance over which the continuous stream breaks up into droplets is 5 mm to 150 mm. Here, the term "dropletizing distance" refers to the distance over which a continuous flow ejected from the end face of the ejection nozzle on the side ejecting the liquid breaks up into droplets.

[0022] The droplet generation distance is longer when the supply pressure is increased, and shorter when the supply pressure is decreased. By adjusting the supply pressure, the droplet generation distance can be set to 5 mm to 150 mm. According to this aspect, the droplet generation distance is set to 5 mm to 150 mm, so the nozzle hole of the injection nozzle can be brought close to the target part, or can be kept far enough away so that the nozzle hole does not hit the target part. This allows the droplet speed to be controlled in accordance with the characteristics of the target part, thereby applying an appropriate impact pressure to the target part. Also, fiber By applying the droplets to metal, resin, or the like, it is possible to clean only the dirt adhering to the surface or inside of the target part without damaging the base material of the target part. In addition, it is possible to obtain the effect of making it easier to apply the droplets to the targeted part of the target part.

[0023] [Embodiment 1] A liquid ejecting apparatus according to a first embodiment of the present invention will be described in detail below with reference to FIG. The liquid ejecting device 25 of this embodiment is a liquid ejecting device that uses a skin cleansing liquid suitable for washing the skin of the face, arms, hands, feet, back, etc., or a hair liquid for use on the scalp and hair. It goes without saying that the liquid ejection device 25 is not limited to one for cleansing the skin.

[0024] As shown in Figure 1, the liquid injection device 25 according to this embodiment includes an injection nozzle 11 having at least one nozzle hole 1 for injecting a liquid 3, a pressurized liquid supply unit 27 for pressurizing the liquid 3 and sending it to the injection nozzle 11, and a control unit 4 for controlling the operation of the pressurized liquid supply unit 27 to cause the liquid 3 injected from the nozzle hole 1 to fly in a state in which it is split into droplets 7 from a continuous stream 5. Furthermore, in the liquid jetting device 25 according to this embodiment, the nozzle hole 1 has a hole diameter b of 0.015 mm to 0.030 mm, and the liquid 3 to be jetted has a viscosity of 0.6 mPa·s to 4.0 mPa·s. The control unit 4 also controls the liquid 3 to be jetted from the jet nozzle 11 at a jet speed in the range of 10 m / s to 80 m / s, and the number of droplets 7 per second (droplets / s), which is the number of droplets 7 generated by the continuous stream 5 splitting into droplets 7, to be 0.8 × 10 5 ~9.0×10 5 The supply pressure of the pressurized liquid supply unit 27 is controlled so as to be within the range.

[0025] Specifically, the liquid injection device 25 includes an injection unit 2 having an injection nozzle 11 that injects the liquid 3, a liquid tank 6 that stores the liquid 3 to be injected, a pump unit that is a pressurized liquid supply unit 27, a liquid suction tube 12 that forms a flow path 10 for the liquid 3 connecting the liquid tank 6 and the pressurized liquid supply unit 27, and a liquid delivery tube 14 that also forms the flow path 10 connecting the pressurized liquid supply unit 27 and the injection unit 2. In this embodiment, the liquid suction tube 12 and the liquid delivery tube 14 are made of a soft resin material, but of course they are not limited to this material. In the pressurized liquid supply unit 27, the control unit 4 controls the pump operation such as the pressure of the liquid 3 sent to the ejection unit 2 through the liquid sending tube 14. That is, the supply pressure is controlled.

[0026] <Properties of the sprayed liquid> As described above, in the liquid ejecting device 25 according to this embodiment, the liquid 3 to be ejected has a viscosity in the range of 0.6 mPa·s to 4.0 mPa·s. The viscosity range of the liquid 3 is set assuming that the environmental temperature in which the liquid ejection device 25 is used is in the range of 5°C to 45°C. For example, the viscosity of water (mPa·s) is 1.519 at 5°C, 1.307 at 10°C, 1.138 at 15°C, 1.002 at 20°C, 0.890 at 25°C, 0.798 at 30°C, and 0.720 at 35°C. By setting the viscosity of the liquid 3 to be used in the range of 0.6 mPa·s to 4.0 mPa·s, the desired number of droplets can be secured when cleaning an object with the droplets, regardless of whether an aqueous liquid or a liquid with a higher viscosity than the aqueous liquid (for example, one containing hydrocarbon components or synthetic compounds) is used, and the cleaning efficiency can be expected to be improved by an appropriate and sufficient impact action.

[0027] <Injection nozzle> In this embodiment, for ease of understanding, the injection nozzle 11 has one nozzle hole 1, and the liquid 3 is injected in a straight line from the nozzle hole 1. In the partially enlarged view of Fig. 1, the symbol F indicates the liquid injection direction. The nozzle hole 1 is configured in a cylindrical shape with a circular outlet in the liquid injection direction F. The liquid 3 sprayed from the nozzle hole 1 is a continuous stream 5 immediately after spraying, but the surface tension of the liquid 3 causes it to quickly break into droplets and break up into a group of droplets 7. The group of droplets 7 flies in a straight line in the liquid spray direction F. The flying group of droplets 7 is successively directed against an object such as skin 9 to clean the object. In the enlarged partial view of FIG. 1, the dimensions of the droplets 7 and the continuous stream 5 are greatly enlarged relative to the other components in order to make the drawing easier to understand, and the relative dimensional relationships are ignored.

[0028] <Nozzle hole diameter and droplet size> In the liquid ejection device 25 according to this embodiment, the liquid 3 is ejected as a continuous stream 5 from the nozzle hole 1 of the ejection nozzle 11 at a predetermined supply pressure, and the continuous stream 5 then splits while flying to generate droplets 7. Although this explanation is somewhat redundant, it is known that the size of the droplets 7 thus generated (hereinafter also referred to as "droplet diameter") has a certain relationship with the hole diameter b of the nozzle hole 1 based on the linear theory of non-viscosity. That is, it is known that the droplets 7 will be approximately 1.88 times the hole diameter b of the nozzle hole 1, regardless of the magnitude of the supply pressure, based on the linear theory of non-viscosity. In other words, if the hole diameter b of the nozzle hole 1 is specifically specified, the size of the droplets 7 to be generated will be determined. If the diameter b of the nozzle hole 1 is 0.015 mm to 0.030 mm, this works out to be 0.0282 mm to 0.0564 mm. Furthermore, taking into consideration that there will be some variation depending on the smoothness of the nozzle hole 1 and environmental conditions, the size of the droplets 7 will be approximately 0.03 mm to 0.1 mm as an average droplet diameter. Here, since most of the droplets 7 are not actually perfectly spherical but are deformed into ellipses or other shapes, the "average droplet diameter" is calculated as the average value based on the longest diameter part and the shortest diameter part.

[0029] <Supply pressure and injection speed> If the supply pressure of the pressurized liquid supply unit is increased, the ejection speed of the liquid 3 ejected from the nozzle hole 1 becomes faster, and if the supply pressure is decreased, the ejection speed of the liquid 3 ejected from the nozzle hole 1 becomes slower. Once the hole diameter b of the nozzle hole 1 is specified, the ejection speed of the liquid 3 ejected from the nozzle hole 1 can be set in the range of 10 m / s to 80 m / s by adjusting the supply pressure according to the hole diameter b. Once the ejection speed of the liquid 3 is determined, the speed of the flying droplets 7 is also determined. The speed of the droplets 7 is approximately the same as the ejection speed, and is therefore 10 m / s to 80 m / s.

[0030] <Supply pressure, injection speed, liquid flow rate, and number of droplets> If the supply pressure is increased, the ejection speed of the liquid 3 ejected from the nozzle hole 1 increases, and therefore the flow rate (ml / min) of the liquid ejected from the nozzle hole 1 increases. If the supply pressure is decreased, the ejection speed of the liquid 3 ejected from the nozzle hole 1 decreases, and therefore the flow rate (ml / min) of the liquid ejected from the nozzle hole 1 decreases. There is such a relationship between the supply pressure and the flow rate (ml / min) of the liquid. Therefore, if the hole diameter b of the nozzle hole 1 is specified, it is possible to set the flow rate (ml / min) of the liquid sprayed from the nozzle hole 1 to a specific flow rate by adjusting the supply pressure according to the hole diameter b. Once the "liquid flow rate (ml / min)" is determined, the number of droplets 7 per unit time (droplets / s) generated by the continuous flow 5 splitting into droplets 7 can be easily calculated by dividing the "liquid flow rate (ml / min)" by the "droplet size," since the "droplet size" generated is in the range of approximately 0.03 mm to 0.1 mm, as described above. In other words, once the "liquid flow rate (ml / min)" is determined, the "droplet frequency" is also determined. If there is more than one nozzle hole 1, the liquid flow rate (ml / min) is multiplied by the number of holes. This also applies to the following explanation.

[0031] As can be understood from the above explanation, in the present liquid ejection device 25, by adjusting the supply pressure of the pressurized liquid supply unit 27 for a specified nozzle hole diameter b in the range of 0.015 mm to 0.030 mm, the ejection speed of the liquid 3 is in the range of 10 m / s to 80 m / s, and the droplet frequency is 0.8 × 10 5 ~9.0×10 5 It is possible to set it to be in the range of That is, a liquid with a viscosity of 0.6 mPa·s to 4.0 mPa·s is sprayed at a velocity in the range of 10 m / s to 80 m / s, and the droplet frequency is 0.8 × 10 5 ~9.0×10 5 The droplets 7 can be repeatedly applied to an object 9 such as skin as flying droplets 7 in the range of .

[0032] Specifically, if the hole diameter b of the nozzle 1 is, for example, 0.024 mm, then based on the linear theory of non-viscosity, the size of the droplets 7 generated will be 0.045 mm, which is approximately 1.88 times the hole diameter b of the nozzle hole 1. In other words, the diameter of the droplets 7 is approximately 0.05 mm. When the supply pressure is adjusted so that the ejection speed of the liquid 3, i.e., the speed of the flying droplets 7, is 10 m / s, the flow rate (ml / min) of the liquid supplied per nozzle hole is approximately 0.3, and the number of droplets generated per second (pieces / s) is approximately 1.0 × 10 5 This becomes: When the supply pressure is adjusted so that the injection speed of the liquid 3, i.e., the speed of the flying droplets 7, is 19 m / s, the flow rate (ml / min) of the liquid supplied per nozzle hole is approximately 0.51, and the number of droplets generated per second (pieces / s) is approximately 1.8 × 10 5 This becomes: When the supply pressure is adjusted so that the injection speed of the liquid 3, i.e., the speed of the flying droplets 7, is 63 m / s, the flow rate (ml / min) of the liquid supplied per nozzle hole is approximately 1.7, and the number of droplets generated per second (pieces / s) is approximately 5.9 × 10 5 This becomes: When the supply pressure is adjusted so that the injection speed of the liquid 3, i.e., the speed of the flying droplets 7, is 80 m / s, the flow rate (ml / min) of the liquid supplied per nozzle hole is approximately 2.2, and the number of droplets generated per second (pieces / s) is approximately 7.6 × 10 5 This becomes:

[0033] Furthermore, in the liquid ejecting device 25 according to this embodiment, the pressurized liquid supply unit 27 is configured to supply the liquid 3 at a supply pressure such that the supply pressure of the liquid 3 ejected from the nozzle holes 1 is 0.3 MPa to 3.2 MPa. The control unit 4 controls the supply pressure of the pressurized liquid supply unit 27 so that the ejection velocity V of the liquid 3 ejected from the nozzle hole 1 is 10 m / s to 80 m / s. When the supply pressure is in the range of 0.3 MPa to 3.2 MPa, it is easy to achieve a state in which the ejection velocity V of the liquid 3 is 10 m / s to 80 m / s. Note that, as long as the ejection velocity V of the liquid 3 is 10 m / s to 80 m / s, the ejection pressure is not limited to the range of 0.3 MPa to 3.2 MPa. There is a correlation between the supply pressure and the injection velocity V, and when the supply pressure is 2.4 MPa, the injection velocity V is approximately 60 m / s, and when the supply pressure is 3.2 MPa, the injection velocity V is approximately 80 m / s.

[0034] In this embodiment, since the liquid spray device 25 is for skin cleansing, the supply pressure is set in accordance with the hole diameter b of the nozzle hole 1 so that the droplet formation distance is within 20 mm. The "droplet formation distance" refers to the distance over which the continuous stream 5 sprayed from the end face 13 of the spray nozzle 11 on the side spraying the liquid 3 breaks up into droplets 7. It is also possible to provide a structure in the injection nozzle 11 that applies vibration to the injected continuous flow 5, so that the droplet formation distance can be adjusted by applying the vibration in addition to controlling the supply pressure.

[0035] In this embodiment, the liquid 3 is a facial cleanser or hair liquid (e.g., a hair growth agent or hair styling product) containing glycerin, but a cosmetic emulsion, water containing an anti-inflammatory component, or blended water containing a bactericidal component may also be used. The liquid 3 may contain vitamin B2 and B6 components that suppress skin inflammation, ibuprofen piconol and dipotassium glycyrrhizinate components that are anti-inflammatory components, and resorcinol, isopropylmethylphenol and ethanol components that are antibacterial components.

[0036] <Specific explanation> Figure 2 shows high-speed images taken with a high-speed camera of the spray state, i.e., the flight trajectory of droplets 7, when the nozzle hole 1 has a hole diameter b of 0.024 mm and the supply pressure of liquid 3 is 0.4 MPa (upper figure) and 1.3 MPa (lower figure). It can be seen that even when the supply pressure of the liquid 3 is 1.3 MPa, the droplet formation distance is not only within about 20 mm, but also within 15 mm.

[0037] <Analysis value> Figure 3 shows an analytical image of a droplet image taken at high speed in a typical liquid jetting state, similar to Figure 2, and then binarized to evaluate the jetting and droplet characteristics. Free software (ImageJ) was used for image processing. In image processing, the captured image was binarized, the area where the droplets were formed was selected as the analysis area, and the number of areas of each droplet 7 within the analysis area and the coordinates of the center 15 of each droplet 7 were calculated.

[0038] ≪Dropletization distance≫ In Figure 3, (A) is a high-speed image of the continuous flow 5 at the outlet of the nozzle hole 1, taken with the upper end face of the photographic field aligned with the end face of the member housing the injection nozzle 11; (B) is a high-speed image of a portion in the process of transitioning to droplet formation, where the continuous flow 5 and droplets 7 are mixed; and (C) is a high-speed image of a portion in the state where the continuous flow 5 has completely split into droplets 7. The droplet formation distance was calculated based on the distance traveled when the continuous flow 5 changed from state (A) to state (C). When the hole diameter b of the nozzle hole 1 was 0.024 mm, the droplets 7 traveled in a straight line well, and the droplet formation distance could be kept within 20 mm by adjusting the supply pressure. Furthermore, the maximum axial deviation of the droplet center 15 from the central axis 17 of the jet nozzle 1 for the flying droplet 7 is 0.2 mm. Therefore, the droplet 7 can be irradiated onto the targeted location.

[0039] <Droplet speed> The droplet velocity was calculated by selecting two images taken with a high-speed camera showing the continuous flow 5 completely splitting into droplets 7 and flying, as shown in Figure 4, and dividing the travel distance d of the droplet 7 of interest by the time interval between taking the two images. The moving distance d was calculated from the length per pixel determined from the angle of view of the captured image, and the shooting time interval was calculated from the shooting speed (frame rate). When the nozzle hole 1 diameter b is 0.024 mm, the droplet speed can be kept at approximately 60 m / s or less when the supply pressure is in the range of 2.4 MPa or less. This makes it possible to prevent the impact pressure of the droplets 7 from being too strong, allowing for safe use on areas such as the skin and scalp.

[0040] ≪Droplet frequency (number of droplets (pieces / s))≫ The droplet frequency (= number of droplets per second) was calculated by finding the average number of droplets present within the angle of view of the captured image, dividing the dimension (length) of the angle of view by the number of droplets to find the average distance between droplets, and then dividing the droplet velocity by the average distance between droplets, as shown in Figure 5. For example, in Figure 5, the average number of droplets formed at the nozzle hole 1 corresponding to droplet 7 within rectangular frame 18 is seven. The average number for the other nozzle holes 1 is also almost the same, seven. The average distance was calculated based on the length per pixel, which is determined by the angle of view of the captured image. Droplet frequency increases with increasing droplet velocity, so by varying the droplet velocity, more impact action can be achieved, leading to more efficient cleaning.

[0041] As described above, when droplets 7 are applied to the target 9 at the above-described droplet speed and droplet frequency (number of droplets (droplets / s)), dirt and oils accumulated on the irradiated area of ​​the target 9, such as the skin or scalp, and especially dirt and oils accumulated at the roots of the hair, are emulsified and softened by the impact, making them easier to remove. If a lotion, emulsion, hair growth agent, or the like is used as the liquid 3, droplets 7 of the liquid 3 are efficiently supplied to the stratum corneum of the skin, pores, hair roots, etc., providing skin care or scalp care effects. This helps maintain good skin elasticity and moisture.

[0042] Table 1 shows the physical properties of several liquids evaluated and their viscosities. Table 2 shows the measured droplet frequency and droplet velocity for liquids A to E listed in Table 1, using jet nozzles 11 with nozzle hole 1 diameters b (hereinafter sometimes referred to as "nozzle diameter b") of 0.015 mm, 0.024 mm, and 0.03 mm. Table 3 shows the measured supply pressure (hereinafter sometimes referred to as "jet pressure") and droplet formation distance for liquids A to E listed in Table 1, using jet nozzles 11 with nozzle diameters b of 0.015 mm, 0.024 mm, and 0.03 mm. Table 2 corresponds to Table 3. That is, the droplet frequency and droplet velocity in Table 2 are the measured values ​​corresponding to each supply pressure in Table 3. The viscosity was measured using a viscoelastic meter AR-G2 (manufactured by TA Instruments Japan, temperature 20°C).

[0043] [Table 1]

[0044] [Table 2]

[0045] [Table 3]

[0046] A regression analysis was performed on the measured droplet frequency and droplet velocity for each of Liquids A to E in Table 2, and the droplet frequency Drop was calculated using the nozzle diameter b (mm), droplet velocity V (m / s), and viscosity η (mPa s) as parameters. freq The relationship between the number of particles and the number of particles (pieces / s) was determined as follows:

[0047]

number

[0048] 6 shows the relationship between the measured droplet frequency (horizontal axis) and the calculated value calculated using relational expression (1), i.e., the calculated droplet frequency (vertical axis), for liquids A to X and pure water at 20°C and 40°C, for which the regression analysis was performed using a jet nozzle 11 with a nozzle diameter b of 0.015 mm. An excellent linear correlation was observed between the two.

[0049] 7 shows the relationship between the actually measured droplet frequency (horizontal axis) and the calculated value calculated using relational expression (1), i.e., the calculated droplet frequency (vertical axis), for liquids A to Y and pure water at 20°C, for which the regression analysis was performed using a spray nozzle 11 with a nozzle diameter b of 0.024 mm. An excellent linear correlation was observed between the two.

[0050] 8 shows the relationship between the measured droplet frequency (horizontal axis) and the calculated value calculated using relational expression (1), i.e., the calculated droplet frequency (vertical axis), for liquids A to E and pure water at 20°C, for which the regression analysis was performed using a spray nozzle 11 with a nozzle diameter b of 0.03 mm. An excellent linear correlation was observed between the two.

[0051] Next, the droplet frequencies were calculated using relational expression (1) for other liquids with known physical properties that were not applied to the regression analysis, namely liquid X, liquid Y, pure water at 20°C, and pure water at 40°C. FIG. 9 shows the relationship between the measured droplet frequency (horizontal axis) and the calculated droplet frequency (vertical axis) for Liquid X, Liquid Y, pure water at 20°C, and pure water at 40°C for each nozzle diameter b shown in the figure. The dashed line in FIG. 9 is the line where both values ​​match perfectly. As can be seen from FIG. 9, the calculated droplet frequency was equal to or slightly lower than the measured droplet frequency, demonstrating a good linear correlation.

[0052] Table 4 shows the measured droplet frequencies for liquids A to X and for pure water at 20°C and pure water at 40°C in a jet nozzle 11 with a nozzle diameter b of 0.015 mm, the calculated droplet frequencies, and the ratio of the two values, i.e., calculated value / measured value. FIG. 10 shows the relationship between the actually measured droplet frequency (horizontal axis) and the calculated value / actual measured value (vertical axis) for liquids A to X and pure water at 20° C. and 40° C. in a jet nozzle 11 with a nozzle diameter b of 0.015 mm.

[0053] [Table 4]

[0054] Table 5 shows the measured droplet frequencies for liquids A to Y and pure water at 20°C in a jet nozzle 11 with a nozzle diameter b of 0.024 mm, the calculated droplet frequencies, and the ratio of the two values, i.e., calculated value / measured value. FIG. 11 shows the relationship between the actually measured droplet frequency (horizontal axis) and the calculated value / actual measured value (vertical axis) for liquids A to Y and pure water at 20° C. in a jet nozzle 11 with a nozzle diameter b of 0.024 mm.

[0055] [Table 5]

[0056] Table 6 shows the measured droplet frequencies for liquids A to E and pure water at 20°C in a jet nozzle 11 with a nozzle diameter b of 0.03 mm, the calculated droplet frequencies, and the ratio of the two values, i.e., calculated value / measured value. FIG. 12 shows the relationship between the actually measured droplet frequency (horizontal axis) and the calculated value / actual measured value (vertical axis) for liquids A to E and pure water at 20° C. in a jet nozzle 11 with a nozzle diameter b of 0.03 mm.

[0057] [Table 6]

[0058] The measured droplet frequency is 1.3×10 5 ~7.1×10 5 In the range of droplets / s, the droplet frequencies calculated from equation (1) for all evaluated liquids all agreed within an error of ±30% (Note: More than 90% of all data had an error of ±20%), demonstrating that the equation derived by regression analysis was valid. As described above, in the liquid injection device 25, when the hole diameter b of the injection nozzle 11 is 0.015 mm to 0.03 mm, the liquid 3 having a viscosity in the range of 0.6 mPa·s to 4.0 mPa·s is transitioned from a continuous flow to droplets, and when the droplet velocity is in the range of 10 m / s to 80 m / s and the droplet frequency is 0.8×10 5 ~9.0×10 5 The ink can be ejected periodically and repeatedly within the range.

[0059] <Explanation of Effects of Embodiment 1> (1) As can be understood from the above explanation, according to this embodiment, for a nozzle hole 1 with a hole diameter b in the range of 0.015 mm to 0.030 mm, using a liquid 3 with a viscosity in the above range, the number of droplets 7 (droplets / s) generated from this liquid 3 can be propelled at the above speed and hit the target 9 such as skin one after another. This allows for effective cleaning of the target 9 such as skin. Furthermore, since the collision of droplets 7 at such an ultrasonic droplet frequency, i.e., at a droplet number (droplets / s), can exert physical stimulation on the skin, improvements in skin condition such as moisturizing and elasticity, i.e., skin care, can be expected. (2) Furthermore, according to this embodiment, the droplet formation distance is set to 20 mm or less, which makes it easier to apply droplets 7 to targeted locations on target object 9 such as skin.

[0060] [Embodiment 2] A liquid ejecting apparatus according to a second embodiment of the present invention will be described in detail below. The liquid ejecting device 25 of this embodiment is a liquid ejecting device that can effectively perform cleaning and other treatments on not only skin but also fibers, metals, resins, and the like. Liquid ejecting device 25 according to this embodiment has almost the same basic structure as the liquid cleaning device of embodiment 1, but differs in the hole diameter b of nozzle hole 1. Therefore, in the following explanation, explanation of the parts common to embodiment 1 will be omitted.

[0061] Table 7 shows the physical properties of several liquids evaluated and their viscosities. Table 8 shows the measured droplet frequency and droplet velocity for liquids F to I listed in Table 7 and pure water at 20°C, using jet nozzles 11 with nozzle hole 1 diameters b (hereinafter sometimes referred to as "nozzle diameter b") of 0.05 mm, 0.08 mm, and 0.12 mm. Table 9 shows the measured supply pressure (hereinafter sometimes referred to as "jet pressure") and droplet formation distance for liquids F to I also listed in Table 7, using jet nozzles 11 with nozzle diameters b of 0.05 mm, 0.08 mm, and 0.12 mm. Tables 8 and 9 correspond to each other. That is, the droplet frequency and droplet velocity in Table 8 are the measured values ​​corresponding to each supply pressure in Table 9. The viscosity was measured using a viscoelastic meter AR-G2 (manufactured by TA Instruments Japan, temperature 20°C).

[0062] [Table 7]

[0063] [Table 8]

[0064] [Table 9]

[0065] A regression analysis was performed on the measured droplet frequency and droplet velocity for each of Liquids F to I in Table 8 and pure water at 20°C. The droplet frequency Drop was calculated using the nozzle diameter b (mm), droplet velocity V (m / s), and viscosity η (mPa·s) as parameters. freq The relationship between the number of particles and the number of particles (pieces / s) was determined as follows:

[0066]

number

[0067] 13 shows the relationship between the actually measured droplet frequency (horizontal axis) and the calculated value calculated using relational expression (2), i.e., the calculated droplet frequency (vertical axis), for liquids F to I and pure water at 20°C, for which the regression analysis was performed using a jet nozzle 11 with a nozzle diameter b of 0.05 mm. An excellent linear correlation was observed between the two.

[0068] 14 is a graph showing the relationship between the actually measured droplet frequency (horizontal axis) and the calculated value calculated using relational expression (2), i.e., the calculated droplet frequency (vertical axis), for liquids F to I and pure water at 20°C, for which the regression analysis was performed using a jet nozzle 11 with a nozzle diameter b of 0.08 mm. An excellent linear correlation was observed between the two.

[0069] 15 is a graph showing the relationship between the actually measured droplet frequency (horizontal axis) and the calculated value calculated using relational expression (2), i.e., the calculated droplet frequency (vertical axis), for liquids F to I and pure water at 20°C, for which the regression analysis was performed using a jet nozzle 11 with a nozzle diameter b of 0.12 mm. An excellent linear correlation was observed between the two.

[0070] Next, the droplet frequencies were calculated using relational expression (2) for pure water at 40° C. and liquid Z, which are other liquids with known physical properties that were not applied to the regression analysis. Figure 16 shows the relationship between the measured droplet frequency (horizontal axis) and the calculated droplet frequency (vertical axis) for pure water at 40°C and liquid Z at each nozzle diameter b shown in the figure. The dashed line in Figure 16 is the line where both values ​​match perfectly. As can be seen from Figure 16, the calculated droplet frequency was the same as or slightly lower than the measured droplet frequency, demonstrating a good linear correlation.

[0071] Table 10 shows the measured droplet frequencies for Liquids F to I, pure water at 20°C, pure water at 40°C, and Liquid Z in a spray nozzle 11 with a nozzle diameter b of 0.05 mm, the calculated droplet frequencies, and the ratio of the calculated values ​​to the measured values. FIG. 17 shows the relationship between the actually measured droplet frequency (horizontal axis) and the calculated value / actual measured value (vertical axis) for liquids F to I, pure water at 20° C., pure water at 40° C., and liquid Z in a jet nozzle 11 with a nozzle diameter b of 0.05 mm.

[0072] [Table 10]

[0073] Table 11 shows the measured droplet frequencies for Liquids F to I, pure water at 20°C, pure water at 40°C, and Liquid Z in a spray nozzle 11 with a nozzle diameter b of 0.08 mm, the calculated droplet frequencies, and the ratio of the two values, i.e., calculated value / measured value. FIG. 18 shows the relationship between the actually measured droplet frequency (horizontal axis) and the calculated value / actual measured value (vertical axis) for liquids F to I, pure water at 20° C., pure water at 40° C., and liquid Z in a jet nozzle 11 with a nozzle diameter b of 0.08 mm.

[0074] [Table 11]

[0075] Table 12 shows the measured droplet frequencies for Liquids F to I, pure water at 20°C, and pure water at 40°C in a jet nozzle 11 with a nozzle diameter b of 0.12 mm, the calculated droplet frequencies, and the ratio of the two values, i.e., calculated value / measured value. FIG. 19 shows the relationship between the actually measured droplet frequency (horizontal axis) and the calculated value / actual measured value (vertical axis) for liquids F to I, pure water at 20° C., and pure water at 40° C. in a jet nozzle 11 with a nozzle diameter b of 0.12 mm.

[0076] [Table 12]

[0077] The measured droplet frequency is 0.5×10 5 ~2.4×10 5 In the range of droplets / s, the droplet frequencies calculated from equation (2) for all evaluated liquids all agreed within an error of ±30% (Note: More than 95% of all data had an error of ±20%), demonstrating the validity of the equation derived by regression analysis. As described above, in the liquid injection device 25, when the hole diameter b of the injection nozzle 11 is 0.05 mm to 0.12 mm, the liquid 3 having a viscosity in the range of 0.6 mPa·s to 4.0 mPa·s is transitioned from a continuous flow to droplets, and when the droplet velocity is in the range of 10 m / s to 70 m / s and the droplet frequency is 0.3×10 5 ~4.0×10 5 The ink can be ejected periodically and repeatedly within the range.

[0078] <Explanation of Effects of Embodiment 2> (1) As can be understood from the above explanation, according to this embodiment, for a nozzle hole 1 with a diameter in the range of 0.05 mm to 0.12 mm, a liquid with a viscosity in the above range is used, and the number of droplets 7 (droplets / s) generated from this liquid 3 can be propelled at the above speed and hit one after another on an object 9 such as skin, fabric, or metal. This allows for effective cleaning and other treatments to be performed on the object 9. (2) Furthermore, according to this embodiment, the droplet generation distance is set to 5 mm to 150 mm, so it is possible to use the injection nozzle 11 by bringing the nozzle hole 1 close to the target part 9, or by keeping the nozzle hole 1 at a sufficient distance so that it does not hit the target part 9. This makes it possible to apply an appropriate impact pressure to the target part 9 by controlling the droplet speed in accordance with the characteristics of the target part 9. Also, fiber By applying the droplets 7 of this embodiment to metal, resin, or the like, it is possible to clean only the dirt adhering to the surface or inside of the target part 9 without damaging the base material of the target part 9. In addition, it is possible to obtain the effect of making it easier to apply the droplets 7 to the targeted part of the target part 9.

[0079] Other Embodiments The liquid injection device 25 according to the embodiment of the present invention is based on the configuration described above, but it is of course possible to modify or omit parts of the configuration within the scope of the gist of the present invention. In the above embodiment, the spray nozzle 11 has been described as having one nozzle hole 1, but the cleaning area can be easily expanded by providing a structure with multiple nozzle holes 1. In this case, it is desirable to determine the number of nozzle holes 1 based on the hole diameter b of the nozzle hole 1, the appropriate flow rate for use, and the desired supply pressure. Furthermore, by providing nozzle holes 1 with different diameters, droplets 7 of different diameters can be sprayed at the same droplet speed. Although droplet diameter does not affect impact pressure, the kinetic energy increases as the number of droplets increases, and therefore the force pressing down on the impacted area increases. As a result, the massage effect can be improved while maintaining the cleaning power. [Explanation of symbols]

[0080] 1 nozzle hole, 2 injection part, 3 liquid, 4 control part, 5 continuous flow, 6 liquid tank, 7 droplet, 9 skin, 10 flow path, 11 injection nozzle, 12 liquid suction tube, 14 liquid delivery tube, 15 center, 17 central axis, 25 liquid injection device, 27 pressurized liquid supply unit, F: Liquid injection direction, b: Nozzle hole diameter

Claims

1. a spray nozzle having at least one nozzle hole for spraying a liquid; a pressurized liquid supply unit that pressurizes the liquid and sends it to the injection nozzle; a control unit that controls the operation of the pressurized liquid supply unit to cause the liquid sprayed from the nozzle hole to fly in a state in which the liquid is split into droplets from a continuous stream, A liquid spraying device for skin cleansing that cleans the skin by successively applying the liquid droplets to the skin, The nozzle hole has a diameter of 0.015 mm to 0.030 mm, The liquid has a viscosity of 0.6 mPa·s to 4.0 mPa·s, The control unit The velocity of the liquid sprayed from the nozzle hole is 10 m / s to 80 m / s, The number of droplets (pieces / s), which is the number of droplets generated per second by the breakup of the continuous flow into droplets, is 0.8×10 ５ ~9.0 x 10 ５ The supply pressure of the pressurized liquid supply unit is controlled so as to be in the range A liquid ejection device characterized by:

2. The liquid ejection apparatus according to claim 1 , The liquid has a viscosity of 0.65 mPa·s to 3.3 mPa·s, the velocity of the liquid sprayed from the nozzle hole is in the range of 19 m / s to 63 m / s; The number of droplets (pieces / s) is 1.3 × 10 ５ ~7.1 x 10 ５ in the range of A liquid ejection device characterized by:

3. 3. The liquid ejection apparatus according to claim 1, The droplet breakup distance at which the continuous flow breaks into droplets is within 20 mm. A liquid ejection device characterized by:

4. a spray nozzle having at least one nozzle hole for spraying a liquid; a pressurized liquid supply unit that pressurizes the liquid and sends it to the injection nozzle; a control unit that controls the operation of the pressurized liquid supply unit to cause the liquid sprayed from the nozzle hole to fly in a state in which the liquid is split into droplets from a continuous stream, A liquid spraying device for cleaning skin, fabric, or metal, which cleans by successively applying the liquid droplets to the skin, fabric, or metal, The nozzle hole has a diameter of 0.05 mm to 0.12 mm, The liquid has a viscosity of 0.6 mPa·s to 4.0 mPa·s, The control unit The velocity of the liquid sprayed from the nozzle hole is 10 m / s to 70 m / s, The number of droplets (pieces / s), which is the number of droplets generated per second by the breakup of the continuous flow into droplets, is 0.3 × 10 ５ ~4.0 x 10 ５ The supply pressure of the pressurized liquid supply unit is controlled so as to be in the range A liquid ejection device characterized by:

5. The liquid ejection apparatus according to claim 4, The liquid has a viscosity of 0.65 mPa·s to 3.3 mPa·s, the velocity of the liquid sprayed from the nozzle hole is in the range of 14 m / s to 52 m / s; The number of droplets (pieces / s) is 0.5 × 10 ５ ~2.4 x 10 ５ in the range of A liquid ejection device characterized by:

6. The liquid ejection apparatus according to claim 4 or 5, The dropletization distance at which the continuous flow breaks into droplets is 5 mm to 150 mm. A liquid ejection device characterized by:

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