Foaming agent addition device, spraying foaming machine, foaming agent addition method, and foam manufacturing method

Abstract

To provide a foam agent addition device, a blowing foam formation machine, a foam agent addition method and a foam production method capable of controlling not according to a liquid pressure in a liquid channel, but according to a drive state of the liquid pump, for stably supplying a foam agent to liquid flowing in the liquid channel, without being impacted by any pulse of liquid pump or filler.SOLUTION: There is provided a foam agent addition device 10 for adding a foam agent E to liquid L1 which is supplied by a liquid pump 40, and includes a filler and flows in a liquid channel 30, and the foam agent addition device comprises: a pump drive detecting part 41 for detecting drive of the liquid pump 40; a foam agent container 11 storing the foam agent E; a foam agent channel 12 for allowing the foam agent E supplied from the foam agent container 11 to flow; a foam agent measuring pump 50 for supplying a prescribed amount of the foam agent E to the liquid channel 12; an opening / closing valve 60 for controlling addition of the foam agent E to the liquid L1, by opening and closing; and an opening / closing valve control part 61 for controlling so as to open the opening / closing valve 60, according to a drive state of the liquid pump 40 detected by the pump drive detecting part 41.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a foaming agent adding device for adding a foaming agent to a liquid, a spraying foaming machine, a foaming agent adding method, and a foam manufacturing method.

Background Art

[0002] Conventionally, a construction method of forming a polyurethane foam by mixing a polyol and an isocyanate on-site and spraying and foaming the mixture on the roof, wall surface, floor, etc. of a building or structure has been widely known. As a method of assisting the workability of polyurethane foam, for example, when mixing two components of a polyol and an isocyanate, a method of adding a foaming agent as a third component (hereinafter referred to as the "froth method") is known. In the froth method, for example, a foaming agent flow path connected to a liquid flow path for supplying a polyol or an isocyanate is provided, and carbon dioxide or the like as a foaming agent is added to the polyol or isocyanate in the liquid flow path through the foaming agent flow path from a tank or the like. A generally used foaming agent adding device is used. The polyol or isocyanate to which a foaming agent such as carbon dioxide is added in the foaming agent adding device is further mixed with an isocyanate or a polyol and then discharged outward.

[0003] Generally, the liquid in the liquid flow path of the foaming agent adding device is supplied under pressure, and the foaming agent is pressurized to a pressure higher than the liquid pressure in the liquid flow path and then added to the liquid flow path, so that the foaming agent can be stably mixed with the liquid. Therefore, a device is used in which the liquid pressure in the liquid flow path and the foaming agent pressure in the foaming agent flow path are measured, and when the foaming agent pressure is higher than the liquid pressure, the on-off valve is opened to add the foaming agent to the liquid (see, for example, Patent Document 1). In addition, a device is also disclosed in which the foaming agent container is heated to pressurize the foaming agent pressure to a pressure higher than the liquid pressure in the liquid flow path without using a foaming agent pump, and the foaming agent is added to the liquid by the differential pressure between the foaming agent pressure and the liquid pressure (see, for example, Patent Documents 2 and 3).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a conventional foaming agent adding device, as a condition for adding a foaming agent, it is necessary that the foaming agent pressure is higher than the liquid pressure. Therefore, while detecting the liquid pressure in the liquid flow path, the addition of the foaming agent is controlled. However, in a conventional foaming agent adding device, since the liquid flowing through the liquid flow path is pulsatingly supplied by a liquid pump, the liquid pressure in the liquid flow path is easily affected by the pulsation of the liquid pump, and it is difficult to control the addition of the foaming agent by a control method according to the liquid pressure. Further, in a conventional foaming agent adding device, when adding a foaming agent to a liquid containing a filler, the filler becomes a resistance in the liquid flow path, etc., so that the liquid pressure is likely to fluctuate, and it is difficult to control the addition of the foaming agent by a control method according to the liquid pressure. Further, in a conventional foaming agent adding device, when opening a switching valve to add a foaming agent to a liquid, the addition amount of the foaming agent fluctuates depending on the differential pressure between the liquid pressure and the foaming agent pressure and the valve opening time of the switching valve. Therefore, it is difficult to grasp the quantification of the addition amount of the foaming agent, and it is difficult to adjust the addition amount of the foaming agent.

[0006] Therefore, an object of the present invention is to provide a foaming agent adding device, a foaming machine for spraying, a foaming agent adding method, and a foam manufacturing method capable of stably supplying a foaming agent to a liquid flowing through a liquid flow path without being affected by the pulsation of a liquid pump and the influence of a filler by performing control according to the driving of the liquid pump instead of control according to the liquid pressure in the liquid flow path. Moreover, an object of the present invention is to provide a foaming agent addition device, a spraying foaming machine, a foaming agent addition method, and a foam manufacturing method capable of supplying a predetermined amount (predetermined volume) of a foaming agent to a liquid flowing through a liquid flow path by using a foaming agent metering pump that supplies a predetermined amount of the foaming agent to the liquid flowing through the liquid flow path.

Means for Solving the Problems

[0007] The gist of the present invention is as follows in [1] to

[17] . [1] A foaming agent addition device for adding a foaming agent to a liquid containing a filler supplied by a liquid pump and flowing through a liquid flow path, comprising: a pump drive detection unit for detecting the drive of the liquid pump; a foaming agent container for storing the foaming agent; a foaming agent flow path for flowing the foaming agent supplied from the foaming agent container; a foaming agent metering pump for supplying a predetermined amount of the foaming agent to the liquid flow path; an on-off valve for controlling the addition of the foaming agent to the liquid by opening and closing; and an on-off valve control unit for controlling to open the on-off valve according to the drive state of the liquid pump detected by the pump drive detection unit. [2] The foaming agent addition device according to [1], wherein the on-off valve control unit opens the on-off valve when the drive position of the liquid pump reaches a predetermined position. [3] The foaming agent addition device according to [1] or [2], wherein the on-off valve control unit controls to close the on-off valve when the predetermined amount of the foaming agent is added to the liquid. [4] The foaming agent addition device according to any one of [1] to [3], wherein the foaming agent metering pump is a positive displacement pump. [5] The foaming agent addition device according to any one of [1] to [4], wherein the foaming agent metering pump is a reciprocating pump. [6] The foaming agent addition device according to any one of [1] to [5], further comprising a foaming agent pressurizing pump for pressurizing the pressure of the foaming agent flowing through the foaming agent flow path to a predetermined pressure on the upstream side of the foaming agent metering pump. [7] The foaming agent addition device according to [6], wherein the foaming agent pressurizing pump is a pump for continuously pressurizing the foaming agent. [8] The foaming agent pressurizing pump is either an axial pump or a gear pump, and the foaming agent adding device according to [6] or [7]. [9] A foaming agent pressure gauge for measuring the pressure of the foaming agent flowing through the foaming agent flow path is provided between the foaming agent pressurizing pump and the foaming agent metering pump, and the foaming agent pressurizing pump pressurizes the foaming agent until the pressure value measured by the foaming agent pressure gauge reaches the predetermined pressure, and the foaming agent adding device according to any one of [6] to [8].

[10] The liquid contains a polyol or a polyisocyanate, and the foaming agent adding device according to any one of [1] to [9].

[11] The foaming agent contains carbon dioxide, and the foaming agent adding device according to any one of [1] to

[10] .

[12] A liquid flow path pressure gauge for measuring the pressure of the liquid flowing through the liquid flow path is provided, and when the liquid pressure measured by the liquid flow path pressure gauge is lower than a predetermined value, the on-off valve control unit controls not to open the on-off valve, and the foaming agent adding device according to any one of [1] to

[11] .

[13] A spraying foaming machine including the foaming agent adding device according to any one of [1] to

[12] .

[14] A foaming agent adding method for adding a foaming agent to a liquid containing a filler supplied by a liquid pump and flowing through a liquid flow path, including a step of detecting the drive of the liquid pump by a pump drive detection unit, a step of supplying the foaming agent accommodated in a foaming agent container to a foaming agent flow path, a step of metering a predetermined amount of the foaming agent to be supplied to the liquid flow path by a foaming agent metering pump, and a step of controlling the addition of the foaming agent to the liquid by opening and closing an on-off valve. In the step of controlling the addition of the foaming agent by opening and closing the on-off valve, the on-off valve control unit controls to open the on-off valve according to the drive status of the liquid pump detected by the pump drive detection unit.

[15] Before the step of metering the foaming agent with a foaming agent metering pump, a step of pressurizing the pressure of the foaming agent flowing through the foaming agent flow path to a predetermined pressure with a foaming agent pressurizing pump and setting the pressure in the foaming agent metering pump to a predetermined pressure is included, and the foaming agent adding method according to

[14] .

[16] The method for adding a foaming agent according to

[14] or

[15] , including the step of measuring the pressure of the liquid flowing through the liquid flow path with a liquid pressure gauge, and in the step of controlling the addition of the foaming agent by opening and closing an on-off valve, when the measured pressure of the liquid pressure gauge is lower than a predetermined value, controlling the on-off valve not to open.

[17] A method for manufacturing a foam, including the step of adding a foaming agent to a liquid containing a filler flowing through a liquid flow path by the method for adding a foaming agent according to any one of

[14] to

[16] .

Effect of the Invention

[0008] In the present invention, by controlling according to the driving status of the liquid pump instead of controlling according to the liquid pressure in the liquid flow path, it is possible to stably supply a foaming agent to the liquid flowing through the liquid flow path without being affected by the pulsation of the liquid pump and the filler, and it is possible to provide a foaming agent adding device, a foaming machine for spraying, a method for adding a foaming agent, and a method for manufacturing a foam. Further, in the present invention, by using a foaming agent metering pump that supplies a predetermined amount of foaming agent to the liquid flowing through the liquid flow path, it is possible to supply a predetermined amount (predetermined volume) of foaming agent to the liquid flowing through the liquid flow path, and it is possible to provide a foaming agent adding device, a foaming machine for spraying, a method for adding a foaming agent, and a method for manufacturing a foam.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0010] [First Embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the foaming agent adding device 10 according to the first embodiment is a device for mixing a foaming agent E into a liquid L1 flowing through a liquid flow path 30.

[0011] <Liquid> The liquid L1 is not particularly limited, but a foam raw material that is a raw material for a foam is preferable. The foaming agent adding device 10 can produce a foam by mixing the foaming agent E into the liquid L1 that is a foam raw material. Examples of the foam include polyurethane foam, phenolic foam, and polystyrene foam. Therefore, the liquid L1 may be any material that can be a raw material for these foams. Among the above, polyurethane foam is preferable from the viewpoints of ease of production, curing rate, foamability, etc. Further, the polyurethane foam is more preferably a rigid polyurethane foam. By using a rigid polyurethane foam, self-adhesiveness, heat insulation, mechanical strength, etc. tend to be good.

[0012] A urethane resin composition for forming a polyurethane foam is generally prepared by mixing one liquid containing a polyol and two liquids containing a polyisocyanate. The urethane resin composition is foamed by the foaming agent E mixed in the composition and cured to form a polyurethane foam. The foaming agent E may be mixed into either the one liquid or the two liquids, but it is preferably mixed into the one liquid from the viewpoint of stability, etc. That is, the foaming agent adding device 10 preferably mixes the liquid foaming agent E into a liquid (one liquid or two liquids) containing either a polyol or a polyisocyanate, and more preferably mixes the foaming agent E into the liquid (one liquid) containing a polyol. The liquid (one-component) containing a polyol is preferably a polyol composition containing a catalyst and a foam stabilizer in addition to the polyol, and may further contain a blowing agent. Note that the blowing agent pre-contained in such a one-component (polyol composition) is also referred to as an "internally added blowing agent" in order to distinguish it from the above-described blowing agent E.

[0013] Further, the liquid L1 contains a filler. When the liquid L1 containing a filler is used as a foam raw material, various properties such as the flame retardancy of the resulting foam are improved. Also, as described above, the liquid L1 is preferably used in a urethane resin composition. By forming a polyurethane foam with the urethane resin composition obtained using the liquid L1, various properties such as the flame retardancy of the resulting polyurethane foam are improved. The liquid L1 containing a filler may be a liquid (one-component or two-component) containing either a polyol or a polyisocyanate, and is preferably a liquid (one-component) containing a polyol. The filler is contained as a solid component in the liquid raw material composition and is generally a component present in the form of granules or powder in the raw material composition. The filler may be a solid at normal temperature (23°C) and normal pressure (1 atm) and does not dissolve in the liquid raw material composition. Examples of the filler include a solid flame retardant and an anti-settling agent. Examples of the solid flame retardant include a red phosphorus-based flame retardant, a boron-containing flame retardant, a bromine-containing flame retardant, a phosphate-containing flame retardant, a chlorine-containing flame retardant, an antimony-containing flame retardant, a metal hydroxide, and a needle-shaped filler. It is preferably at least one selected from the group consisting of a red phosphorus-based flame retardant, a boron-containing flame retardant, and a bromine-containing flame retardant.

[0014] 〈Red phosphorus-based flame retardant〉 The red phosphorus-based flame retardant may consist of elemental red phosphorus, or may be red phosphorus coated with a resin, metal hydroxide, metal oxide, etc., or may be a mixture of red phosphorus with a resin, metal hydroxide, metal oxide, etc. The resin for coating or mixing with red phosphorus is not particularly limited, but examples include thermosetting resins such as phenolic resin, epoxy resin, unsaturated polyester resin, melamine resin, urea resin, aniline resin, and silicone resin. From the viewpoint of flame retardancy, metal hydroxides are preferred as the compound for coating or mixing. As the metal hydroxide, those described later may be appropriately selected and used.

[0015] 〈Boron-containing flame retardant〉 Examples of the boron-containing flame retardant used in the present invention include borax, boron oxide, boric acid, borate, etc. Examples of boron oxide include diboron trioxide, boron trioxide, diboron dioxide, tetraboron trioxide, tetraboron pentoxide, etc. Examples of borates include borates of alkali metals, alkaline earth metals, elements of Group 4, Group 12, and Group 13 of the periodic table, and ammonium. Specifically, alkali metal borates such as lithium borate, sodium borate, potassium borate, cesium borate, alkaline earth metal borates such as magnesium borate, calcium borate, barium borate, zirconium borate, zinc borate, aluminum borate, ammonium borate, etc. The boron-containing flame retardant may be used alone or in combination of two or more. The boron-containing flame retardant used in the present invention is preferably a borate, and more preferably zinc borate.

[0016] 〈Bromine-containing flame retardant〉 The bromine-containing flame retardant is not particularly limited as long as it is a compound containing bromine in its molecular structure and is solid at normal temperature and pressure. Examples include aromatic compounds containing brominated aromatic rings. Examples of the brominated aromatic ring-containing aromatic compounds include monomeric organic bromine compounds such as hexabromobenzene, pentabromotoluene, hexabromobiphenyl, decabromobiphenyl, decabromodiphenyl ether, octabromodiphenyl ether, hexabromodiphenyl ether, bis(pentabromophenoxy)ethane, ethylenebis(pentabromophenyl), ethylenebis(tetrabromophthalimide), and tetrabromobisphenol A.

[0017] The brominated aromatic ring-containing aromatic compound may also be a bromine compound polymer. Specifically, examples include brominated polycarbonates such as polycarbonate oligomers produced from brominated bisphenol A, copolymers of this polycarbonate oligomer and bisphenol A, diepoxy compounds produced by the reaction of brominated bisphenol A and epichlorohydrin, and the like. Further, examples include brominated epoxy compounds such as monoepoxy compounds obtained by the reaction of brominated phenols and epichlorohydrin, poly(brominated benzyl acrylate), condensates of brominated phenols of brominated polyphenylene ether, brominated bisphenol A, and cyanuric chloride, brominated polystyrenes such as brominated (polystyrene), poly(brominated styrene), and crosslinked brominated polystyrene, and crosslinked or non-crosslinked brominated poly(α-methylstyrene). Compounds other than the brominated aromatic ring-containing aromatic compounds such as hexabromocyclododecane may also be used. These bromine-containing flame retardants may be used alone or in combination of two or more. Among them, brominated aromatic ring-containing aromatic compounds are preferred, and monomeric organic bromine compounds such as ethylenebis(pentabromophenyl) are particularly preferred.

[0018] 〈Phosphate-containing flame retardant〉 Examples of the phosphate-containing flame retardants include phosphates composed of salts of various phosphoric acids and at least one metal or compound selected from metals of Groups IA to IVB of the periodic table, ammonia, aliphatic amines, aromatic amines, and heterocyclic compounds containing nitrogen in the ring. The phosphoric acid is not particularly limited, and examples thereof include monophosphoric acid, pyrophosphoric acid, polyphosphoric acid, and the like. Examples of the metals of Groups IA to IVB of the periodic table include lithium, sodium, calcium, barium, iron(II), iron(III), aluminum, and the like. Examples of the aliphatic amine include methylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, piperazine, and the like. Examples of the aromatic amine include aniline, o-tolidine, 2,4,6-trimethylaniline, anisidine, 3-(trifluoromethyl)aniline, and the like. Examples of the heterocyclic compound containing nitrogen in the ring include pyridine, triazine, melamine, and the like.

[0019] Specific examples of the phosphate-containing flame retardant include, for example, monophosphates such as aluminum orthophosphate, pyrophosphates, polyphosphates, and the like. Here, the polyphosphate is not particularly limited, and examples thereof include ammonium polyphosphate, piperazine polyphosphate, melamine polyphosphate, ammonium amide polyphosphate, aluminum polyphosphate, and the like. One or more of the above-mentioned phosphate-containing flame retardants can be used.

[0020] 〈Chlorine-containing flame retardant〉 Examples of the chlorine-containing flame retardant include those commonly used in the flame-retardant resin composition, and examples thereof include polychlorinated naphthalene, chlorendic acid, dodecachlorododecahydrodimethanodibenzocyclooctene sold under the trade name "Dechlorane Plus", and the like.

[0021] 〈Antimony-containing flame retardant〉 Examples of the antimony-containing flame retardant include, for example, antimony oxide, antimonate, pyroantimonate, and the like. Examples of the antimony oxide include antimony trioxide, antimony pentoxide, and the like. Examples of the antimonate include sodium antimonate, potassium antimonate, and the like. Examples of the pyroantimonate include sodium pyroantimonate, potassium pyroantimonate, and the like. The antimony-containing flame retardant may be used alone or in combination of two or more. The preferred antimony-containing flame retardant used in the present invention is antimony trioxide.

[0022] 〈Metal hydroxide〉 Examples of the metal hydroxide include magnesium hydroxide, calcium hydroxide, aluminum hydroxide, iron hydroxide, nickel hydroxide, zirconium hydroxide, titanium hydroxide, zinc hydroxide, copper hydroxide, vanadium hydroxide, tin hydroxide and the like. The metal hydroxide may be used alone or in combination of two or more.

[0023] 〈Needle-like filler〉 Examples of the needle-like filler include potassium titanate whisker, aluminum borate whisker, magnesium-containing whisker, silicon-containing whisker, wollastonite, sepiolite, zonolite, eleustonite, boehmite, rod-like hydroxyapatite, glass fiber, carbon fiber, graphite fiber, metal fiber, slag fiber, gypsum fiber, silica fiber, alumina fiber, silica alumina fiber, zirconia fiber, boron nitride fiber, boron fiber, stainless steel fiber and the like. One or more of these needle-like fillers can be used.

[0024] The aspect ratio (length / diameter) of the needle-like filler preferably ranges from 5 to 50, more preferably from 10 to 40. The aspect ratio can be determined by observing 50 needle-like fillers with a scanning electron microscope and measuring their length and width.

[0025] 〈Anti-settling agent〉 The anti-settling agent may be used in combination with the above-mentioned solid flame retardant, for example. By using the anti-settling agent, precipitation of solid flame retardants and the like dispersed in the urethane resin composition can be prevented. In addition, the use of the anti-settling agent makes it easier to uniformly disperse the solid flame retardant. The anti-settling agent is generally solid at normal temperature and normal pressure and usually becomes a solid content (insoluble content) in the urethane resin composition.

[0026] As the anti-settling agent, there is no particular limitation. For example, it is preferable to use one or more selected from carbon black, powdered silica, organic clay, etc., and among these, powdered silica is more preferable. As the carbon black used as the anti-settling agent, those produced by methods such as the furnace method, the channel method, and the thermal method can be used. For the carbon black, commercially available products can be appropriately selected and used. Also, as the powdered silica, fumed silica, colloidal silica, silica gel, etc. can be used. Among these, fumed silica is preferable. As the fumed silica, Aerosil (registered trademark) of Nippon Aerosil Co., Ltd. etc. can be used.

[0027] The liquid L1 may contain, as a filler, an inorganic filler other than the above solid flame retardant and anti-settling agent. Examples of the inorganic filler include silica, diatomaceous earth, alumina, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, ferrites, calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dawsonite, hydrotalcite, calcium sulfate, barium sulfate, gypsum fiber, calcium silicate, talc, clay, mica, wollastonite, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass beads, silica balloon, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon balloon, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, various magnetic powders, slag fiber, fly ash, silica alumina fiber, alumina fiber, silica fiber, and zirconia fiber, etc. These inorganic fillers may be used alone or in combination of two or more.

[0028] In addition, the urethane resin composition obtained by mixing the liquid L1 containing the filler can contain various additives such as a liquid flame retardant, an antioxidant, a heat stabilizer, a metal deactivator, an antistatic agent, a crosslinking agent, a lubricant, a softening agent, and a pigment, in addition to a curing catalyst, a foam stabilizer, and a filler.

[0029] <Blowing agent> The internal blowing agent is not particularly limited, and hydrofluoroolefin (HFO), hydrofluorocarbon (HFC), hydrocarbon, diethyl ether, etc. can be used. Examples of the hydrofluoroolefin (HFO) used as the internal blowing agent include fluoroalkenes having about 3 to 6 carbon atoms, preferably 3 or 4 carbon atoms, and more preferably 3 carbon atoms. The hydrofluoroolefin may be a hydrochlorofluoroolefin having a chlorine atom. Examples of the hydrofluorocarbon (HFC) include hydrofluorocarbons having about 1 to 4 carbon atoms, and the hydrofluorocarbon may have a chlorine atom. Examples of the hydrocarbon include hydrocarbons having 2 to 5 carbon atoms. Hydrocarbons having 2 to 5 carbon atoms are preferably hydrocarbons having 3 or 4 carbon atoms, and LPG mainly composed of propane and butanes can also be used.

[0030] On the other hand, the blowing agent E may be any blowing agent that can be used for foaming by the froth method, and may be a blowing agent that becomes a gas at room temperature (23°C) and normal pressure (1 atm), and preferably has a boiling point of less than 0°C under normal pressure. The blowing agent E is not particularly limited, and examples include hydrofluoroolefin (HFO), carbon dioxide, etc. The froth method is a method in which a blowing agent E that becomes a gas at normal temperature and normal pressure is mixed with a foam raw material such as a liquid (one-component) containing a polyol and foamed. The liquid containing the polyol may contain a blowing agent (internal blowing agent) in advance. In such a case, the blowing agent E has a function as a foaming aid for improving foamability and workability.

[0031] In the present invention, it is preferable to use carbon dioxide as the foaming agent E. Carbon dioxide can be mixed with the liquid L1 in a liquid state by pressurization described later, thereby improving the miscibility with the liquid L1. In addition, using carbon dioxide reduces the environmental impact. However, carbon dioxide may be mixed with the liquid L1 in a supercritical or subcritical state. When using carbon dioxide as the foaming agent E, it may be used alone, or a mixed gas of hydrofluoroolefin (HFO) and carbon dioxide may be used.

[0032] (Foaming agent adding device) Hereinafter, the foaming agent adding device 10 will be described in more detail. The foaming agent adding device 10 includes a pump drive detection unit 41, a foaming agent container 11 that stores the foaming agent E, a foaming agent flow path 12, a foaming agent metering pump 50, an on-off valve 60, and an on-off valve control unit 61. The foaming agent adding device 10 is a device for adding the foaming agent E to the liquid L flowing through the liquid flow path 30.

[0033] A liquid pump 40 is connected to the liquid flow path 30, and the liquid L1 filled in a container (not shown) such as a drum can is supplied to the liquid flow path 30 by the liquid pump 40 and sent out. The liquid pump 40 may be either a positive displacement type or a non-positive displacement type, but a positive displacement pump is preferable. Although a positive displacement pump has a large pulsation, according to the present invention, even if the pulsation is large, a stable supply of the foaming agent is possible. The positive displacement pump may be either a reciprocating type or a rotary type pump, but a reciprocating pump such as a syringe pump with a seal mechanism on the drive unit side and a plunger pump with a seal mechanism on the cylinder side is preferable. Also, the positive displacement type may be a variable displacement type or a constant displacement type. The liquid pump 40 periodically drives various drive units such as a cylinder, a gear, a vane, and a plunger by rotation or linear motion, etc., depending on the type of the pump, to repeatedly discharge the fluid. For example, a syringe pump repeatedly performs a linear motion between the bottom dead center and the top dead center of the cylinder.

[0034] The liquid L1 flowing through the liquid flow path 30 is flowed under a state pressurized to the discharge pressure. A liquid flow path pressure gauge 31 is connected to the liquid flow path 30, and the liquid pressure LP of the liquid L1 flowing through the liquid flow path 30 is measured by the liquid flow path pressure gauge 31. From the viewpoint of working stability, the pressure of the liquid L1 containing the filler flowing through the liquid flow path 30 is preferably 6 to 10 MPa.

[0035] The liquid pump 40 is provided with a pump drive detection unit 41. The pump drive detection unit 41 detects the drive of the liquid pump 40. The pump drive detection unit 41 transmits pump drive information DI regarding the detected drive of the liquid pump 40 to the on-off valve control unit 61. As described above, the liquid pump 40 periodically drives the drive unit by reciprocating or rotating motion, etc., but the pump drive detection unit 41 can detect at which position the drive unit is driven in that period. For example, in a reciprocating pump such as a syringe pump, it reciprocates between the bottom dead center and the top dead center, but the pump drive detection unit 41 can detect at which position the drive unit of the pump is driven in that reciprocating motion. Similarly, for a rotary pump, it suffices to be able to detect at which position of the rotational motion the drive unit is driven. A sensor is used as the pump drive detection unit 41. Specific sensors include a laser distance sensor that measures the drive position of the drive unit of the liquid pump 40 as a distance, and a position sensor that detects that the drive unit of the liquid pump 40 has reached a certain position (for example, the top dead center or the bottom dead center, etc.).

[0036] As the foaming agent container 11, a pressure-resistant container is used. For example, a known gas cylinder may be used. The foaming agent container 11 may store the foaming agent E in a pressurized state. Further, the foaming agent container 11 may be provided with a heater (not shown). By heating with the heater, the internal pressure of the foaming agent container 11 rises, and thereby, it becomes easier to send the foaming agent E to the foam flow path 12 in a highly pressurized state.

[0037] As described above, the foaming agent flow path 12 is a path for supplying the foaming agent E from the foaming agent container 11 to the liquid flow path 30. The foaming agent flow path 12 may be provided with a flow path cooling device (not shown) composed of a coolant or the like, whereby the foaming agent E flowing through the foaming agent flow path 12 can be cooled. By cooling the foaming agent E in the foaming agent flow path 12, it becomes difficult for the foaming agent E to vaporize in each foaming agent flow path, and it becomes easier to mix with the liquid L in a liquid state. The temperature inside the foaming agent flow path 12 is preferably maintained in the range of -20 to 20°C. Also, the pressure inside the foaming agent flow path 12 is preferably adjusted so that the pressure of the foaming agent E sent to the liquid flow path 30 and the foaming agent metering pump 50 is in the range of 5 to 12 MPa. By adjusting the foaming agent E in the foaming agent flow path 12 within the above range, it becomes easier to supply it to the liquid flow path 30 in a liquid state. When the foaming agent E is supplied to the liquid flow path 30 in a liquid state, it becomes easier to mix with the liquid L1.

[0038] A foaming agent metering pump 50 is provided in the middle of the foaming agent flow path 12. The foaming agent metering pump 50 receives the foaming agent E flowing through the foaming agent flow path 12 and supplies a predetermined amount (predetermined volume) of the foaming agent E to the liquid flow path 30 by metering. The foaming agent metering pump 50 may be a non-positive displacement type or a positive displacement type, but a positive displacement pump is preferred because it is easy to supply a fixed amount of foaming agent and easy to vary the volume. As the positive displacement pump, reciprocating pumps such as a syringe pump and a plunger pump are preferred, and among them, a syringe pump with high metering accuracy for one shot amount and excellent high-pressure transportation is preferred. Also, the foaming agent metering pump 50 may be a variable volume type or a fixed volume type, but the variable volume type is preferred. By varying the volume, the predetermined amount of the foaming agent E to be supplied can be varied. The variable volume control of the foaming agent metering pump 50 is preferably composed of a known control device including a CPU (microprocessor), a memory, an input port, an output port, etc., and may be composed of a personal computer or the like, or may be variable manually.

[0039] In the foaming agent flow path 12, an on-off valve 60 is provided on the downstream side of the foaming agent metering pump 50. The on-off valve 60 controls the addition of the foaming agent E to the liquid L1 by opening and closing. The on-off valve 60 supplies the foaming agent E flowing through the foaming agent flow path 12 to the liquid L1 by opening. On the other hand, the on-off valve 60 stops the supply of the foaming agent E to the liquid L1 by closing. The on-off valve 60 is composed of, for example, an electromagnetic valve.

[0040] An on-off valve control unit 61 for controlling the opening and closing of the on-off valve 60 is connected to the on-off valve 60. The on-off valve control unit 61 receives the pump drive information DI of the liquid pump 40 from the pump drive detection unit 41 and performs control to open the on-off valve 60 according to the drive status of the liquid pump 40. Specifically, when the drive position in the liquid pump 40 reaches a predetermined position (predetermined position), control is performed to open the on-off valve 60. By opening the on-off valve 60, a predetermined amount of the foaming agent E is supplied to the liquid flow path 30 as described above. The liquid pump 40 is driven periodically as described above. When the on-off valve 60 opens when the position (drive position) of the drive unit of the liquid pump 40 reaches the predetermined position, the foaming agent E is supplied to the liquid L at the same timing in that cycle. Here, since the liquid pump 40 supplies the liquid L to the flow path 30 with substantially the same behavior (that is, substantially the same pressure and the same flow rate) at the same timing in the cycle, when a predetermined amount (that is, a constant amount) of the foaming agent is supplied to the flow path 30 at that timing, the supply of the foaming agent E to the liquid L becomes stable. That is, in the present embodiment, by performing control to open the on-off valve 60 when the drive unit of the liquid pump 40 reaches a predetermined position (predetermined position), rather than control according to the liquid pressure in the liquid flow path 30, stable supply of the foaming agent E to the liquid L containing the filler becomes possible. In addition, by performing control to open the on-off valve 60 when it reaches the predetermined position and then close it, the opening and closing of the on-off valve will be repeated.

[0041] The above-mentioned predetermined position is not particularly limited. However, when the liquid pump 40 is a reciprocating pump such as a syringe pump, it may be any of the top dead center, bottom dead center, or a specific position between them, but it is preferably either the top dead center or the bottom dead center. When reaching the top dead center or the bottom dead center, thereafter, the pressure of the liquid L supplied to the liquid flow path 30 decreases. Therefore, when the predetermined position is the top dead center or the bottom dead center, the foaming agent E is supplied at the timing when the pressure has decreased, making it easier to mix the foaming agent E into the liquid L. Also, in the case of a reciprocating pump, the above-mentioned predetermined position does not have to be at one location during one cycle in which the driving unit reaches from the top dead center to the bottom dead center and then from the bottom dead center to the top dead center, and it may be at two or more locations. For example, both the top dead center and the bottom dead center may be set as the predetermined positions. Also, in the case of a rotary pump, similarly, for example, among the rotation cycle (0 to 360°), a position of n° (where n is any of 0 to 360) at any specific position may be set as the predetermined position.

[0042] The opening / closing control unit 61 may control the opening / closing valve 60 to open once per cycle of the driving unit of the liquid pump 40, or may control the opening / closing valve 60 to open once every two cycles, or may control the opening / closing valve 60 to open once every n cycles (n is an integer of 3 or more). Also, the opening / closing control unit 61 may control the driving unit of the liquid pump 40 to open the opening / closing valve 60 a plurality of times during one cycle. For example, it may be controlled to open once per half cycle. Note that opening the valve once per cycle means, for example, when setting the top dead center as the predetermined position, opening the valve every time the top dead center is reached. The same applies to the case of the bottom dead center. Also, for example, when a specific position between the top dead center and the bottom dead center is set as the above-mentioned predetermined position, in any case when the driving unit reaches the predetermined position, it is not necessary to open the opening / closing valve 60, and it is preferable to control it to open at any time when the driving unit moves from the top dead center to the bottom dead center or from the bottom dead center to the top dead center. Furthermore, in a double-acting type (e.g., a double-acting plunger pump) having a plurality of drive units, the on-off valve may be controlled based on the drive of any one of the drive units, or may be controlled based on the drives of the plurality of drive units. When controlled based on the drives of the plurality of drive units, for example, the valve may be opened each time the drive unit reaches a predetermined position.

[0043] When a predetermined amount of foaming agent E is added from the foaming agent metering pump 50 to the liquid L1 in the liquid flow path 30, the on-off valve control unit 61 controls to close the on-off valve 60. In this way, when a predetermined amount of foaming agent E is added from the foaming agent metering pump 50 to the liquid L1 in the liquid flow path 30, by closing the on-off valve 60, a predetermined amount (predetermined volume) of foaming agent E can be stably supplied without adding an excess foaming agent E to the liquid L1 flowing through the liquid flow path 30. Here, the on-off valve control unit 61 may measure the amount of the foaming agent E sent from the foaming agent metering pump 50, and when the sent amount reaches a specified amount, determine that a predetermined amount of foaming agent E has been added to the liquid L1 and close the valve, or may add a predetermined amount of foaming agent E to the liquid L1 by closing the valve after a certain time has elapsed since the valve was opened. Also, the on-off valve control unit 61 may detect the drive of the foaming agent metering pump 50 and close the valve when it is determined that all of the predetermined amount of foaming agent E metered by the foaming agent metering pump 50 has been added.

[0044] In addition, the on-off valve control unit 61 receives the liquid pressure LP of the liquid L1 flowing through the liquid flow path 30 measured by the liquid flow path pressure gauge 31, and when the measured pressure LP is lower than a predetermined value, controls not to open the on-off valve 60. By the control of the on-off valve control unit 61, when the measured pressure LP is lower than a predetermined value, the on-off valve 60 is not opened, so that the addition of the foaming agent E when the amount of the liquid L1 flowing through the liquid flow path 30 is small can be prevented. Examples of the case where the measured pressure LP is lower than a predetermined value include when the foaming agent adding device 10 is started, stopped, and when the liquid flow path 30 is clogged. The predetermined value of the measured pressure LP is preferably set to a value lower than the fluctuation of the pulsation of the liquid pump 40, and for example, it may be set to 3 MPa.

[0045] The supply amount of the foaming agent E to the liquid L1 flowing through the liquid flow path 30 is preferably 0.05 to 5.0% in terms of the volume ratio at the time of adding the foaming agent E to the liquid L1, more preferably 0.1 to 4.5%, and even more preferably 0.15 to 4.0%. By setting the supply amount of the foaming agent E within the above range, it becomes possible to contain an appropriate amount of the foaming agent in the polyol or the like, and the polyurethane foam can be appropriately foamed. Note that the supply amount of the foaming agent E to the liquid L1 flowing through the liquid flow path 30 is preferably adjusted according to the foaming agent E used. For example, when the foaming agent E is carbon dioxide, it is preferably 0.2 to 2.0%, and when the foaming agent E is a mixed gas of hydrofluoroolefin and carbon dioxide, it is preferably 0.4 to 3.5%.

[0046] (Spraying foaming machine) As shown in FIG. 2, the spraying foaming machine 1 includes the above-described foaming agent adding device 10. The spraying foaming machine 1 in the present embodiment is a device for forming a polyurethane foam. However, in the present invention, the spraying foaming machine 1 is not limited to a device for forming a polyurethane foam, and may be a device for forming other foams. The polyurethane foam is preferably a rigid polyurethane foam as described above. Further, the spraying foaming machine 1 is a spraying foaming machine for on-site spraying, and is a device for forming a polyurethane foam at the construction site brought to the construction site where the polyurethane foam is constructed.

[0047] In addition to the foaming agent adding device 10, the spraying foaming machine 1 further includes the above-described liquid flow path 30 (hereinafter, also referred to as the first liquid flow path 30) and the liquid pump 40 (hereinafter, also referred to as the first liquid pump 40). The spraying foaming machine 1 also includes a second liquid flow path 32 through which a liquid L2 different from the liquid L1 flows, and a liquid pump 42 (hereinafter, also referred to as the second liquid pump 42) that sends the liquid L2 to the second liquid flow path 32. The first and second liquid pumps 40 and 42 are connected to a liquid container (not shown) such as a drum can, and send the liquids L1 and L2 sucked from the liquid container to the first and second liquid flow paths 30 and 32, respectively.

[0048] As described above, the polyurethane foam can be formed by mixing a one-component liquid containing a polyol and a two-component liquid containing a polyisocyanate, followed by foaming and curing. The liquid L1 containing the filler flowing through the first liquid flow path 30 is one of the one-component liquid or the two-component liquid, and the liquid L2 flowing through the second liquid flow path 32 is the other of the one-component liquid or the two-component liquid. However, it is preferable that the liquid L1 containing the filler is the one-component liquid containing the polyol and the liquid L2 is the two-component liquid containing the polyisocyanate.

[0049] The spraying foaming machine 1 includes a spray gun 70. The spray gun 70 includes a discharge part 70A and a mixing part 70B. In the mixing part 70B, the first and second liquid flow paths 30 and 35 merge. The one-component liquid and the two-component liquid flowing through the first and second liquid flow paths 30 and 32 are mixed in the mixing part 70B, and the mixture (urethane resin composition) is sprayed from the discharge part 70A. At this time, the urethane resin composition may be sprayed onto the construction target surfaces such as the roofs, wall surfaces, and floors of buildings and structures. The sprayed urethane resin composition foams and cures to become a polyurethane foam. The polyurethane foam is used, for example, as a heat insulating material.

[0050] In the above spraying foaming machine 1, since the liquid L1 in which the foaming agent E is appropriately mixed using the foaming agent adding device 10 is used as a raw material for the polyurethane foam, a polyurethane foam having good foamability and sprayability can be formed. Further, in the spraying foaming machine 1 of the present invention, since the urethane resin composition obtained by mixing the liquid L1 containing the filler is used as a raw material, a polyurethane foam excellent in various performances such as flame retardancy can be formed.

[0051] [Method of Adding Foaming Agent] The method of adding the foaming agent E to the liquid L1 in the foaming agent adding device 10 in the present embodiment will be described in detail with reference to the flowchart of FIG. 3. In the following, the case where the foaming agent E is carbon dioxide will be taken as a specific example to explain the pressure, temperature, etc. However, when the foaming agent E is another substance, the pressure, temperature, etc. may be set according to the properties of the substance.

[0052] First, in step S1, the pump drive detector 41 detects the drive of the liquid pump 40. Specifically, the pump drive detector 41 detects the drive position of the drive unit of the liquid pump 40 for pressurizing the liquid L1 flowing through the liquid flow path 30, and obtains pump drive information DI regarding the detected drive of the liquid pump 40. The pump drive detector 41 is preferably a laser displacement sensor capable of continuously measuring the drive position of the drive unit of the liquid pump 40. The obtained pump drive information DI is transmitted to the on-off valve control unit 61.

[0053] Next, in step S2, the foaming agent E stored in the foaming agent container 11 is supplied to the foaming agent flow path 12. The temperature of the foaming agent E supplied to the foaming agent flow path 12 is preferably maintained in the range of -20 to 20°C. Also, the pressure inside the foaming agent flow path 12 is preferably adjusted so that the pressure of the foaming agent E sent to the foaming agent metering pump 50 is in the range of 5 to 12 MPa.

[0054] Next, in step S3, a predetermined amount of the foaming agent E to be supplied to the liquid flow path 30 is metered by the foaming agent metering pump 50. When the foaming agent E is carbon dioxide, the predetermined amount metered by the foaming agent metering pump 50 is 0.1 to 0.5 cc.

[0055] Next, in step S4, the addition of the foaming agent E to the liquid L1 is controlled by opening and closing the on-off valve 60. In the step of controlling the addition of the foaming agent E by opening and closing the on-off valve 60, the on-off valve control unit 61 controls the on-off valve 60 to open according to the drive status of the liquid pump 40 detected by the pump drive detector 41. Specifically, the on-off valve control unit 61 receives the pump drive information DI of the liquid pump 40 from the pump drive detector 41, and when the drive position of the drive unit in the liquid pump 40 reaches a predetermined position (predetermined position), controls the on-off valve 60 to open.

[0056] However, the above-described steps only show an example of control, and may be performed in any order as long as it does not conflict with the gist of the present invention. For example, step S1 may be performed in parallel with step S2 or step S3, or may be performed after step S2 or after step S3.

[0057] [Foam manufacturing method] By using the foaming agent adding device 10 according to the first embodiment of the present invention, a foam can be formed. The method for manufacturing a polyurethane foam in the present embodiment includes the steps of step S1 to step S4 described above, and further includes a step of discharging, from a discharging device, a mixture prepared by mixing a liquid L1 obtained by adding a foaming agent E to a liquid L1 flowing through a liquid flow path 30 with a liquid L2 by a spraying foaming machine 1. Specifically, it includes the following steps (1) to (5). (1) A step of detecting the driving of the liquid pump 40 by the pump drive detection unit 41 (2) A step of supplying the foaming agent E accommodated in the foaming agent container 11 to the foaming agent flow path 12 (3) A step of measuring a predetermined amount of the foaming agent E to be supplied to the liquid flow path 30 by the foaming agent metering pump 50 (4) A step of controlling the addition of the foaming agent E to the liquid L1 by opening and closing the on-off valve 60 (5) A step of discharging, from a discharging device, a mixture prepared by mixing a liquid L1 obtained by adding a foaming agent E to a liquid L1 flowing through a liquid flow path 30 with a liquid L2 by a spraying foaming machine 1

[0058] As described above, in the present embodiment, by providing the pump drive detection unit 41 that detects the driving of the liquid pump 40, the driving state of the liquid pump 40 is detected, and control is performed according to the driving state of the liquid pump 40. In this way, instead of control according to the liquid pressure in the liquid flow path 30, by performing control according to the driving state of the liquid pump 40, the foaming agent E can be stably supplied to the liquid L1 flowing through the liquid flow path 30 without being affected by the pulsation of the liquid pump 40 and the filler. Further, in the present embodiment, by using the foaming agent metering pump 50 that supplies a predetermined amount of the foaming agent E to the liquid L1 flowing through the liquid flow path 30, a predetermined amount (predetermined volume) of the foaming agent can be stably supplied to the liquid L1 flowing through the liquid flow path 30.

[0059] [Second Embodiment] Next, a second embodiment of the present invention will be described in detail. In the second embodiment, the difference from the first embodiment is that, as shown in FIG. 4, a foaming agent pressurizing pump 80 is provided in the foaming agent flow path 12. Hereinafter, the differences between the second embodiment and the first embodiment will be described. In addition, parts where the description is omitted are the same as those in the first embodiment. In the following description, members having the same configuration as those in the first embodiment are denoted by the same reference numerals.

[0060] The foaming agent pressurizing pump 80 is provided upstream of the foaming agent metering pump 50 in the foaming agent flow path 12. The pressure of the foaming agent E flowing through the foaming agent flow path 12 is likely to change, such as decreasing due to the suction of the foaming agent metering pump 50, and there are problems such as the foaming agent E vaporizing or flowing backward due to the change in pressure. Therefore, the foaming agent pressurizing pump 80 pressurizes the foaming agent E flowing through the foaming agent flow path 12 to a predetermined pressure, so that a constant amount of the foaming agent E can be stably supplied to the foaming agent metering pump 50 provided on the downstream side. The predetermined pressure is preferably 5 to 12 MPa from the viewpoint of preventing the vaporization and backflow of the foaming agent. The foaming agent pressurizing pump 80 is preferably a pump that can pressurize and supply the foaming agent E at a stable pressure from the viewpoint of being able to supply the foaming agent E to the foaming agent metering pump 50 in a constant amount. Among them, it is preferably either an axial pump or a gear pump.

[0061] As shown in FIG. 4, the foaming agent adding device 10 of the present embodiment may include a foaming agent pressure gauge 81 that measures the pressure of the foaming agent E flowing through the foaming agent flow path 12 between the foaming agent pressurizing pump 80 and the foaming agent metering pump 50. In that case, the blowing agent E supplied to the blowing agent metering pump 50 may be pressurized by the blowing agent pressurizing pump 80 until the pressure measured by the blowing agent pressure gauge 81 reaches a predetermined pressure.

[0062] Also, the blowing agent pressurizing pump 80 may be controlled by a pump control unit (not shown). The pressure value measured by the blowing agent pressure gauge 81 is transmitted to the pump control unit. When the pressure value is less than the predetermined pressure, the pump control unit controls to continue the supply of the blowing agent E from the blowing agent pressurizing pump 80 to the blowing agent metering pump 50. Also, when the pressure value reaches the predetermined pressure, it may be controlled to stop the supply of the blowing agent E from the blowing agent pressurizing pump 80 to the blowing agent metering pump 50. As described above, by performing control to pressurize the pressure of the blowing agent E to a predetermined pressure using the blowing agent pressure gauge 81, it becomes possible to supply the blowing agent E to the blowing agent metering pump 50 provided on the downstream side more stably.

[0063] The method for adding the blowing agent E to the liquid L1 in the blowing agent adding device 10 in the present embodiment includes, as shown in the flowchart of FIG. 5, a step of pressurizing the pressure of the blowing agent E flowing through the blowing agent flow path 12 to a predetermined pressure with the blowing agent pressurizing pump 80 before the step of measuring a predetermined amount of the blowing agent E to be supplied to the liquid flow path 30 with the blowing agent metering pump 50 (step S3). In the step of pressurizing to a predetermined pressure with the blowing agent pressurizing pump 80, the pressure of the blowing agent E flowing through the blowing agent flow path 12 may be measured by the blowing agent pressure gauge 81 provided between the blowing agent pressurizing pump 80 and the blowing agent metering pump 50. By measuring the pressure with the blowing agent pressure gauge 81, the accuracy of pressurizing to a predetermined pressure with the blowing agent pressurizing pump 80 can be improved, and it becomes possible to supply the blowing agent E to the blowing agent metering pump 50 provided on the downstream side more stably.

[0064] As described above, in the present embodiment, by providing the foaming agent pressurizing pump 80, a constant amount of the foaming agent E can be stably supplied to the foaming agent metering pump 50, and the foaming agent metering pump 50 can stably supply a predetermined amount (predetermined volume) of the foaming agent to the liquid L1 flowing through the liquid flow path 30.

[0065] However, the above-described steps merely show an example of control, and may be performed in any order as long as it does not conflict with the gist of the present invention. For example, step S1 may be performed in parallel with step S2, step S10, or step S3, or may be performed after step S2, after step S10, or after step S3.

[0066] [Other Embodiments] As described above, the foaming agent adding device, the spraying foaming machine, the foaming agent adding method, and the foam manufacturing method shown and described in each embodiment are examples of the present invention, and the present invention is not limited to the configurations of the above embodiments, and various improvements and modifications are possible without departing from the gist of the present invention, and components may be added as appropriate. For example, in the foaming agent adding method, as shown in FIG. 6, a step (step S20) of measuring the pressure of the liquid L1 flowing through the liquid flow path 30 with the liquid pressure gauge 31 may be included. When step S20 is included, in the step (step S4) of controlling the addition of the foaming agent E to the liquid L1 by opening and closing the on-off valve 60, when the measured pressure LP of the liquid pressure gauge 31 is lower than a predetermined value, it is preferable to control not to open the on-off valve 60. By including step S20 in the foaming agent adding method, when the amount of the liquid L1 flowing through the liquid flow path 30 is small, such as at the start-up or stop of the foaming agent adding device 10 or when the liquid flow path 30 is clogged, the foaming agent E cannot be added at a stable ratio, so control not to add can be performed. The predetermined value of the measured pressure LP is preferably set to a value lower than the fluctuation of the pulsation of the liquid pump 40, and for example, it may be set to 3 MPa.

[0067] However, it is not necessary to perform step S1 in these orders. For example, step S1 may be performed in parallel with step S2, step S3, or step S20, or may be performed after step S2, after step S3, or after step S20.

[0068] In addition, although the foaming agent addition device 10 in each embodiment has been described as including the liquid pressure gauge 31, the liquid pressure gauge 31 may be omitted.

Explanation of Signs

[0069] 1 Foaming machine for spraying 10 Foaming agent addition device 11 Foaming agent container 12 Foaming agent flow path 30 Liquid flow path (first liquid flow path) 31 Liquid flow path pressure gauge 32 Second liquid flow path 40 Liquid pump (first liquid pump) 41 Pump drive detection unit 41 42 Liquid pump (second liquid pump) 50 Foaming agent metering pump 60 On-off valve 61 On-off valve control unit 70 Spray gun 70A Discharge part 70B Mixing part 80 Foaming agent pressurizing pump 81 Foaming agent pressure gauge E Foaming agent L1, L2 Liquid

Claims

1. A foaming agent adding device for adding a foaming agent to a liquid containing a filler supplied by a liquid pump and flowing through a liquid flow path, a pump drive detection unit for detecting the drive of the liquid pump, a foaming agent container for storing the foaming agent, a foaming agent flow path through which the foaming agent supplied from the foaming agent container flows, a foaming agent metering pump for supplying a predetermined amount of the foaming agent to the liquid flow path, an on-off valve for controlling the addition of the foaming agent to the liquid by opening and closing, and an on-off valve control unit for controlling to open the on-off valve according to the drive state of the liquid pump detected by the pump drive detection unit, The foaming agent adding device is provided with a foaming agent pressurizing pump for pressurizing the pressure of the foaming agent flowing through the foaming agent flow path to a predetermined pressure on the upstream side of the foaming agent metering pump.

2. The foaming agent adding device according to claim 1, wherein the foaming agent pressurizing pump is a pump for continuously pressurizing the foaming agent.

3. The foaming agent adding device according to claim 1 or 2, wherein the foaming agent pressurizing pump is either an axial pump or a gear pump.

4. A foaming agent pressure gauge for measuring the pressure of the foaming agent flowing through the foaming agent flow path is provided between the foaming agent pressurizing pump and the foaming agent metering pump, The foaming agent adding device according to any one of claims 1 to 3, wherein the foaming agent pressurizing pump pressurizes the foaming agent until the pressure value measured by the foaming agent pressure gauge reaches the predetermined pressure.

5. A foaming agent adding device for adding a foaming agent to a liquid containing a filler supplied by a liquid pump and flowing through a liquid flow path, a pump drive detection unit for detecting the drive of the liquid pump, a foaming agent container for storing the foaming agent, a foaming agent flow path through which the foaming agent supplied from the foaming agent container flows, a foaming agent metering pump for supplying a predetermined amount of the foaming agent to the liquid flow path, an on-off valve for controlling the addition of the foaming agent to the liquid by opening and closing, and an on-off valve control unit for controlling to open the on-off valve according to the drive state of the liquid pump detected by the pump drive detection unit, The foaming agent adding device is provided with a liquid flow path pressure gauge for measuring the pressure of the liquid flowing through the liquid flow path, The on-off valve control unit controls not to open the on-off valve when the pressure of the liquid measured by the liquid flow path pressure gauge is lower than a predetermined value.

6. The foaming agent adding device according to any one of claims 1 to 5, wherein the on-off valve control unit opens the on-off valve when the driving position of the liquid pump reaches a predetermined position.

7. The foaming agent adding device according to any one of claims 1 to 6, wherein the on-off valve control unit controls to close the on-off valve when the predetermined amount of the foaming agent is added to the liquid.

8. The foaming agent adding device according to any one of claims 1 to 7, wherein the foaming agent metering pump is a positive displacement pump.

9. The foaming agent adding device according to any one of claims 1 to 8, wherein the foaming agent metering pump is a reciprocating pump.

10. The foaming agent adding device according to any one of claims 1 to 9, wherein the liquid contains a polyol or a polyisocyanate.

11. The foaming agent adding device according to any one of claims 1 to 10, wherein the foaming agent contains carbon dioxide.

12. A spraying foaming machine comprising the foaming agent adding device according to any one of claims 1 to 11.

13. A foaming agent adding method for adding a foaming agent to a liquid containing a filler supplied by a liquid pump and flowing through a liquid flow path, comprising: a step of detecting the driving of the liquid pump by a pump driving detector; a step of supplying the foaming agent contained in a foaming agent container to a foaming agent flow path; a step of metering the predetermined amount of the foaming agent to be supplied to the liquid flow path by a foaming agent metering pump; a step of controlling the addition of the foaming agent to the liquid by opening and closing an on-off valve; before the step of metering the foaming agent by the foaming agent metering pump, a step of pressurizing the pressure of the foaming agent flowing through the foaming agent flow path to a predetermined pressure by a foaming agent pressurizing pump and setting the pressure in the foaming agent metering pump to the predetermined pressure; and In the step of controlling the addition of the foaming agent by opening and closing the on-off valve, the on-off valve control unit controls to open the on-off valve according to the driving state of the liquid pump detected by the pump driving detector. A foaming agent adding method.

14. A foaming agent adding method for adding a foaming agent to a liquid containing a filler supplied by a liquid pump and flowing through a liquid flow path, comprising: a step of detecting the driving of the liquid pump by a pump driving detector; a step of supplying the foaming agent contained in a foaming agent container to a foaming agent flow path; a step of metering the predetermined amount of the foaming agent to be supplied to the liquid flow path by a foaming agent metering pump; A step of measuring the pressure of the liquid flowing through the liquid flow path with a liquid pressure gauge; A step of controlling the addition of the foaming agent to the liquid by opening and closing an on-off valve, and In the step of controlling the addition of the foaming agent by opening and closing the on-off valve, the on-off valve control unit controls the on-off valve to open according to the driving state of the liquid pump detected by the pump drive detection unit. A foaming agent addition method, in the step of controlling the addition of the foaming agent by opening and closing the on-off valve, when the measured pressure of the liquid pressure gauge is lower than a predetermined value, controlling the on-off valve not to open.

15. A foam manufacturing method, including a step of adding a foaming agent to a filler-containing liquid flowing through a liquid flow path by the foaming agent addition method according to claim 13 or 14.

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