JP2000094437A - Mixing device of polyurethane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mixing device of polyurethane capable of being used both in mixing in two systems of agitator mixing (forced agitation) and air mixing. SOLUTION: A chamber for forced agitation and a chamber for air mixing 4 are attached while being replaceable to the lower surface of a mixing head body 1. When the chamber for air mixing 4 is attached, not only the chamber for forced agitation but also an impeller are removed from an impeller fixing threaded portion 26 of a shaft 2. The chamber portion 26 through a sealing member 38 impeller fixing threaded portion 26 through a sealing member 38 outside from a mixing chamber inside the chamber for air mixing 4 at a shaft lead-out portion 36 comprising a cylindrical body 37. This prevents polyol or diisocyanate mixed at air mixing from sticking to the impeller and the impeller fixing threaded portion 26 and achieves quick response to use for agitator mixing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane mixing apparatus which can be used both as an agitator mix for forcibly stirring a polyol and a diisocyanate and an air mix for mixing a polyol and a diisocyanate by mixing air. .

[0002]

2. Description of the Related Art Conventionally, in order to foam urethane by a low pressure method, a mixer of an agitator mix method is roughly divided into:
An air-mix type mixer is used. Agitator mix type mixers are intended for use with low expansion ratio, and are generally used for foaming wood carvings or molded products such as paper or plastic materials that dislike air voids on the surface, such as cooler boxes. As shown in FIG. 7, a sectional structure of the mixing head is shown in FIG.
This is a method of forcibly stirring the polyol which is fixedly discharged from the polyol inlet 8 into the chamber 3 by rotating at a high speed of 00 or more and the diisocyanate which is fixedly discharged into the chamber 3 from the diisocyanate inlet 15. On the other hand, the purpose of the air-mixing type mixer is to use a material having a relatively high expansion ratio, for example, for foaming a heat insulating material into a sandwich panel for construction or the like. As shown in the cross-sectional structure of the head, the polyol and diisocyanate, which are quantitatively discharged by the pump, are discharged into the chamber 4 from the polyol inlet 8 and the diisocyanate inlet 15 and mixed with the air fed from the stirring air inlet 22. , 1
In this method, a hose 39 having a length of about 500 mm and an injection pipe 40 having a length of 500 mm or more connected to the end of the hose 39 are guided to a work and injected.

[0003]

In order to carry out the above two types of mixing, dedicated mixers are required. For this purpose, for example, the mixing head main body 1 of the agitator-mix type mixer shown in FIG. 7 is provided with an agitating air inlet 22 and the hose 3 of FIG. It is conceivable to connect 39 and the injection pipe 40 for use. In that case, impeller 29
There is a concept of using the device with the device mounted, and a concept of using the device with the impeller 29 removed. However, when the mixer is used with the impeller 29 attached, air is mixed in from the stirring air inlet 22 while rotating the mixer. In this case, a gap between the inner periphery of the chamber 3 and the impeller 29 is formed. Due to the small size, back pressure is applied to the upper end surface side of the impeller 29, and the mixed solution in the chamber 3 flows back into the gap between the shaft insertion hole of the mixing head body 1 and the shaft 2 or flows back into the air supply path. And other troubles. However, if the impeller 29 is used with the impeller 29 removed, the polyol liquid, the diisocyanate liquid or a mixture thereof adheres to the impeller fixing screw portion at the tip of the shaft 2, and it takes time and effort to clean and remove the liquid. Since the volume in the tank 3 becomes large, the liquid and the air are separated to form a pulsating flow, which causes a problem that mixing cannot be performed. In each case, it was found that there was a problem.

The present invention has been made in order to solve the above-mentioned problems, and a single mixer is replaced with a specially processed air mix chamber by replacing the chamber of the agitator mix type mixer with two types of mixers. It is an object of the present invention to provide a polyurethane mixing device that can also be used for mixing.

[0005]

According to the present invention, there is provided a polyurethane mixing apparatus comprising: a mixing head main body; a shaft vertically supported by the mixing head main body such that a lower end of the mixing head main body protrudes toward a lower surface side of the mixing head main body;
A forced stirring chamber and an air mixing chamber which are replaceably attached to the lower surface of the mixing head body so as to surround the lower end of the shaft protruding from the lower surface of the mixing head body. And
The mixing head body has a polyol supply path for supplying a fixed amount of polyol into the chamber for forced stirring or a chamber for air mixing, a diisocyanate supply path for supplying a fixed amount of diisocyanate, and an air supply path for stirring for supplying stirring air. Prepare. The forced stirring chamber has a built-in impeller and has a mixed liquid discharge port opened at the lower end side. An impeller fixing screw portion into which the impeller is removably inserted and coupled is provided at a tip of a lower end portion of the shaft. The air mix chamber has a shaft lead-out portion for leading the impeller fixing screw portion of the shaft out of the mixing chamber in the air mix chamber, and a gap between the shaft lead-out portion and an upper end of the impeller fixing screw portion. And a mixed liquid discharge port formed so as to penetrate inside and outside the air mix chamber.

The above-mentioned polyol supply path communicates the polyol inlet provided in the mixing head main body, the polyol outlet facing the chamber for forced stirring or the chamber for air mixing, and the polyol inlet and the polyol outlet. A polyol flow passage. The diisocyanate supply path is a diisocyanate input port provided in the mixing head body, a diisocyanate discharge port facing the chamber for forced stirring or the chamber for air mixing, and a diisocyanate flow passage communicating the diisocyanate input port and the diisocyanate discharge port. Having. The stirring air supply path is
A stirring air inlet provided in the mixing head body, a stirring air outlet facing the chamber for forced stirring or the chamber for air mixing, and a stirring air flow passage communicating the stirring air inlet and the stirring air outlet. Having. The shaft lead-out portion may be formed of a cylinder that is provided continuously below the mixing chamber of the air-mix chamber and that allows the impeller fixing screw portion to pass therethrough.

[0007]

When the forced stirring chamber is mounted on the lower surface side of the mixing head body, the impeller is rotated at high speed in the forced stirring chamber as in the conventional agitator mix type mixer shown in FIG. The polyol and diisocyanate, which are quantitatively supplied into the stirring chamber, can be forcibly stirred, and foaming of a wood carving having a low foaming ratio or a molded article such as a paper surface material or a plastic surface material that does not like air voids on its surface Suitable for.

The chamber for forced agitation is removed from the lower surface side of the mixing head main body, and the impeller is removed from the impeller fixing screw portion of the shaft, and the air mixing chamber is replaced on the lower surface side of the mixing head main body. Thus, after the shaft is stopped, the polyol and the diisocyanate are discharged from the mixed liquid discharge port while the polyol and the diisocyanate are mixed by discharging the fixed amount of the polyol and the diisocyanate into the air mixing chamber and supplying the air under pressure. If the liquid is introduced into a sandwich panel through a hose and a filling pipe connected to the liquid discharge port and injected, for example, it is suitable for foaming a heat insulating material into the sandwich panel.

At this time, the impeller fixing screw portion of the shaft is led out of the mixing chamber in the air mixing chamber by the shaft leading portion, and a gap between the shaft leading portion and the upper end of the impeller fixing screw portion is sealed. Thus, the impeller fixing screw portion of the shaft can be prevented from adhering the air-mixed polyol solution, diisocyanate solution, or a mixture thereof. Therefore, even when replacing the chamber for forced agitation after this air mixing and reusing it in the agitator mix method, the impeller fixing screw part of the shaft can save the trouble of cleaning with the cleaning liquid, and the impeller can be inserted and connected as it is. Can be. Further, since the impeller is removed during the air mixing, the air mixing can be performed without the problem of back pressure or backflow that occurs when air mixing is performed with the impeller attached as described above.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a polyurethane mixing apparatus according to the present invention will be described below with reference to FIGS. FIG. 1 is a longitudinal sectional front view of a mixing head showing an operating state during agitator mixing (forced stirring), FIG. 2 is a longitudinal sectional front view of a mixing head showing an operating state during air mixing, and FIG. 3 is an enlarged view of a portion A in FIG. FIG. 4 is a partially cutaway perspective view of the mixing head showing a use state during air mixing.

As shown in FIGS. 1 and 2, the polyurethane mixing apparatus according to the present invention has a mixing head body 1 and a vertically penetrating lower end portion of the mixing head body 1 such that the lower end of the mixing head body 1 projects toward the lower surface side of the mixing head body. A forced stirring chamber 3 (see FIG. 1), which is replaceably mounted on the lower surface of the mixing head body 1 so as to surround the lower end of the shaft 2 protruding from the lower surface of the mixing head body 1. And an air mixing chamber 4 (see FIG. 2).

The structures of the mixing head body 1 itself and the forced stirring chamber 3 itself are basically the same as those of the conventional agitator mixer shown in FIG. 1 and 2, the mixing head body 1 includes a polyol supply path 5 for supplying a fixed amount of polyol into the chamber 3 for forced stirring or a chamber 4 for air mixing, a diisocyanate supply path 6 for supplying a fixed amount of diisocyanate, and air for stirring. And an agitation air supply path 7 for feeding the pressure.

The polyol supply path 5 includes a polyol inlet 8 opened on the upper surface of the mixing head body 1, a polyol outlet 9 opened on a lower portion of the lower surface of the mixing head body 1 near the center, a polyol inlet 8 and a polyol outlet. A polyol flow passage 10 communicating with the outlet 9;
Further, a polyol return port 11 is opened on one side surface of the mixing head body 1, and the polyol return port 11 and a middle part of the polyol flow passage 10 are communicated with each other by a bypass 12,
A polyol switching three-way valve 13 is provided at the intersection of the polyol flow passage 10 and the bypass 12. The polyol input port 8 and the polyol return port 11 are connected to each other via a polyol tank 45 and a pump 14 for feeding a fixed amount of polyol. The polyol switching three-way valve 13 is connected to the polyol inlet 8
When the polyol is in communication with the polyol return port 11, the polyol circulates through the polyol tank 45, the pump 14, the polyol input port 8, the polyol flow path 10, the bypass 12, and the polyol return port 11, and the polyol switching three-way valve 1
3 switches the polyol to the polyol flow path 1
0 to the polyol outlet 9.

The diisocyanate supply path 6 has a diisocyanate inlet 15 opened symmetrically with the polyol inlet 8 on the upper surface of the mixing head body 1 and an opening symmetrical with the polyol outlet 9 at a position near the center of the lower surface of the mixing head body 1. A diisocyanate discharge port 16, and a diisocyanate flow passage 17 communicating the diisocyanate input port 15 and the diisocyanate discharge port 16. Further, a diisocyanate return port 18 is symmetrical to the polyol return port 11 on the other side surface of the mixing head body 1. Opening to
The diisocyanate return port 18 and a middle part of the diisocyanate flow passage 17 are communicated by a bypass 19, and a diisocyanate switching three-way valve 20 is provided at the intersection of the diisocyanate flow passage 17 and the bypass 19. The diisocyanate input port 15 and the diisocyanate return port 18 are connected to a pipe via a diisocyanate tank 46 and a pump 21 for quantitatively feeding diisocyanate. When the diisocyanate switching three-way valve 20 connects the diisocyanate input port 15 and the diisocyanate return port 18, the diisocyanate is supplied to the diisocyanate tank 45, the pump 21, the diisocyanate input port 15, the diisocyanate flow passage 17, the bypass 19, and the diisocyanate return port 1.
8, the diisocyanate is discharged to the diisocyanate discharge port 16 through the diisocyanate flow passage 17 by switching the diisocyanate switching three-way valve 20.

The stirring air supply path 7 includes a stirring air inlet 22 opened on the back of the mixing head main body 1,
A stirring air discharge port 23 opened at a position near the center of the lower surface of the mixing head body 1, and a stirring air flow path 24 communicating between the stirring air input port 22 and the stirring air discharge port 23.
And The stirring air inlet 22 is connected to a pressurized air supply device (not shown) such as a compressor by piping. Then, the pressurized air supplied from the pressurized air supply device is discharged to the stirring air discharge port 23 through the stirring air flow passage 24.

A shaft 2 is vertically supported at the center of the mixing head body 1 via a bearing member 25. The upper end 2a of the shaft 2 is a motor (not shown).
Directly or via a belt. The lower end 2 b of the shaft 2 projects downward from the center of the lower surface of the mixing head body 1. On the lower surface of the mixing head body 1, the polyol discharge port 9, the diisocyanate discharge port 16, and the stirring air discharge port 23 are arranged in proximity to the lower end 2 b of the shaft 2. The lower end portion 2b of the shaft 2 is formed with a tapered portion 2c which is tapered downward, and a screw portion 2d formed of a screw in a direction tightened by the rotation of the shaft 2 is formed at the tip of the tapered portion 2c. The taper portion 2c and the screw portion 2d constitute an impeller fixing screw portion 26.

As shown in FIG. 1, the forced stirring chamber 3 is formed in a vertically long cylindrical shape and has a flange 27 at an upper end thereof, and a mixed liquid discharge port 28 is narrowed and opened at a lower end.
The forced stirring chamber 3 includes a columnar impeller 29 having a spiral groove on the outer periphery and is concentrically incorporated therein. The impeller 29 has a spiral groove in the illustrated example, but there is also a pine cone or a pin type. This impeller 29
Has a shaft hole 30 at the center of the upper end, and a female screw 31 screwed with the screw portion 26 is provided at the inner deep end of the shaft hole 30,
By inserting the shaft hole 30 into the impeller fixing screw portion 26 at the lower end of the shaft 2 and screwing the female screw 31 into the screw portion 2d, the impeller 29 is detachably connected to the lower end portion of the shaft 2.

The upper end of the chamber 3 for forced stirring is placed at the center of the lower surface of the mixing head main body 1, and a bolt 32 is screwed into the lower surface of the mixing head main body 1 through the flange 27, thereby forcibly stirring the mixing head main body 1. Chamber 3 is detachably attached. However, when the forced stirring chamber 3 is attached, the polyol discharge port 9, the diisocyanate discharge port 16, and the stirring air discharge port 23 face the inside of the forced stirring chamber 3, respectively.

The air-mixing chamber 4 is formed in a funnel shape of an upwardly expanding shape as shown in FIG. 2 to FIG. 4 in which the lower surface of the mixing head body 1 is replaced with the forced stirring chamber 3. A flange 33 having the same diameter as the flange 27 of the forced stirring chamber 3 is provided at an upper end thereof, a mixed liquid discharge port 35 is formed in a part of the peripheral wall 34 so as to penetrate inside and outside, and a shaft is led out to a lower part of the mixing chamber 4a. A part 36 is provided. The shaft lead-out portion 36 is formed of a bottomed cylindrical body 37 continuously provided so as to allow the impeller fixing screw portion 26 of the shaft 2 to be inserted into a lower portion of the mixing chamber 4 a in the air mixing chamber 4. This cylinder 3
A sealing member 38 made of an O-ring or the like is fitted into the upper part of the inside 7. A hose 39 having a length of about 1500 mm is connected to the mixed solution discharge port 35, and this hose 3
An injection pipe 40 having a length of 500 mm or more is connected to the end of the pipe 9.

Next, how to use the polyurethane mixing apparatus having the above-described structure will be described. When the polyol and the diisocyanate are forcibly stirred during foaming into a mold such as a wood carving having a low expansion ratio, the impeller 29 is inserted into the impeller fixing screw portion 26 at the lower end of the shaft 2 as shown in FIG. The forced stirring chamber 3 is attached to the lower surface of the mixing head body 1. Thus, when the impeller 29 is rotated at high speed together with the shaft 2 and the pumps 14 and 21 supply a fixed amount of the polyol and the diisocyanate into the forced stirring chamber 3 via the polyol supply path 5 and the diisocyanate supply path 6, the forced stirring chamber 3 In the inside, the polyol and the diisocyanate are forcibly stirred, and the mixed liquid is discharged from the mixed liquid discharge port 28 to be subjected to foam molding of a mold. In this agitator mix, stirring air is not basically used, but a small amount of stirring air may be used together only when the polyol and diisocyanate are difficult to mix depending on the mixing ratio and viscosity.

In the case of using for foaming a heat insulating material or the like on a building sandwich panel having a relatively high foaming ratio, the forced stirring chamber 3 is removed from the lower surface of the mixing head body 1 and the impeller 29 is mounted on the shaft 2. After being removed from the fixing screw portion 26, the air mixing chamber 4 is replaced with the lower surface of the mixing head body 1 as shown in FIG. At this time, the impeller fixing screw part 26 of the shaft 2 is inserted into the shaft lead-out part 36 (cylindrical body 37) of the air mix chamber 4 and a gap between the upper end of the impeller fixing screw part 26 and the shaft lead-out part 36 is formed. By closing with the seal material 38, the impeller fixing screw portion 26 is led out from the mixing chamber 4 a in the air mixing chamber 4 through the seal material 38.
Thus, after the shaft 2 is stopped, fixed amounts of polyol and diisocyanate are discharged into the air-mixing chamber 4 by the pumps 14 and 21 via the polyol supply path 5 and the diisocyanate supply path 6, and at the same time, stirring air is supplied. When air is supplied under pressure from the port 22 and mixed therein, the polyol and the diisocyanate are mixed while being turbulent in the mixing chamber 4a and the hose 39,
It is guided to the work through the injection pipe 40 and injected to be used for forming a foamed heat insulating material or the like.

It should be noted that in this air mixing, not only the forced stirring chamber 3 but also the impeller 29 is removed, and the impeller fixing screw portion 26 of the shaft 2 is connected to the air mixing chamber via the shaft lead-out portion 36. 4 in that it is led out of the mixing chamber 4a inside the sealing member 4 via a sealing material 38. Thereby, the polyol liquid, the diisocyanate liquid or the mixed liquid during the air mixing does not adhere to the impeller 29 or the impeller fixing screw portion 26. Therefore, when switching to using the agitator mix after air mixing, the impeller 29
Since there is no need to wash, it can be used as it is, and work efficiency can be improved. Further, it is not necessary to clean the impeller fixing screw portion 26 of the shaft 2, and in particular, the liquid such as polyol adhered to the screw portion 2 d of the impeller fixing screw portion 26 is difficult to remove even if it is hardened with a cleaning liquid. The cleaning unnecessary effect of the part 26 is remarkable. As described above, since the troublesome cleaning work of the impeller fixing screw portion 26 before the use of the agitator mix can be omitted, the work of mounting the impeller 29 to the impeller fixing screw portion 26 can be performed simply and quickly, and the use of the agitator mix can be performed immediately after using the air mix. It is convenient to respond immediately.

In the above embodiment, the shaft lead-out portion 36 of the air mixing chamber 4 is constituted by a bottomed cylindrical body 37 integrally formed at the lower end of the chamber 4, but is not limited to this. As shown in FIG. The shaft lead-out portion 36 may be constituted by a cylindrical body 41 integrally formed at the lower end of the chamber 4 so as to be open to the bottom, or a relatively short cylindrical body 42 is provided at the lower end of the chamber 4 as shown in FIG. The lower part of the screw part 26 below the sealing material 38 is
2 may be completely derived to the outside.

[0024]

According to the present invention, a stirring air supply path is provided in the mixing head body in addition to the polyol supply path and the diisocyanate supply path, and a forced stirring chamber and an air mixing chamber are provided on the lower surface of the mixing head body. With a simple means of being replaceably mounted, this one unit can be used for both agitator mix and air mix, which is convenient and economical. Moreover, it is possible to prevent the polyol or impeller to be air-mixed from adhering to the impeller fixing screw portion of the shaft and the impeller, which is extremely advantageous in achieving the dual use of the above two methods.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view of a mixing head showing a use state at the time of agitator mixing.

FIG. 2 is a vertical sectional front view of a mixing head showing a use state during air mixing.

FIG. 3 is an enlarged view of a portion A in FIG. 2;

FIG. 4 is a partially cutaway perspective view of a mixing head showing a use state during air mixing.

FIG. 5 is a cross-sectional view of an air mixing chamber showing another embodiment.

FIG. 6 is a sectional view of an air mixing chamber showing still another embodiment.

FIG. 7 is a vertical sectional front view of a conventional agitator mix type mixer.

FIG. 8 is a vertical sectional front view of a conventional air mix type mixer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mixing head main body 2 Shaft 3 Chamber for forced stirring 4 Chamber for air mixing 6 Polyol supply path 7 Diisocyanate supply path 8 Polyol input port 9 Polyol discharge port 10 Polyol flow path 15 Diisocyanate input port 16 Diisocyanate discharge port 17 Diisocyanate flow path 22 Stirring Air inlet 23 Stirred air outlet 24 Stirred air flow passage 26 Impeller fixing screw part 28,35 Mixed liquid discharge port 29 Impeller 36 Shaft lead-out part 37,41,42 Cylindrical body 38 Seal material

Claims (3)

[Claims] 1. A mixing head main body, a shaft vertically supported by the mixing head main body such that a lower end protrudes toward a lower surface side of the mixing head main body, and a lower end of the shaft protruding from a lower surface of the mixing head main body. A forced stirring chamber and an air mixing chamber that are replaceably attached to the lower surface side of the mixing head body so as to surround the mixing head body. The mixing head body is inserted into the forced stirring chamber or the air mixing chamber. It is provided with a polyol supply path for supplying a constant amount of polyol, a diisocyanate supply path for supplying a constant amount of diisocyanate, and an air supply path for stirring for pressure-feeding stirring air. The forced stirring chamber has a built-in impeller and a lower end. Beside A liquid mixture discharge opening, an impeller fixing screw portion to which the impeller is removably inserted and coupled at a tip of a lower end portion of the shaft; and the air mix chamber includes an impeller of the shaft. A shaft lead-out part for leading the fixing screw part to the outside from the mixing chamber in the air mix chamber, a sealing material for closing a gap between the shaft lead-out part and the upper end of the impeller fixing screw part, A polyurethane mixing device comprising: a mixed liquid discharge port formed to penetrate inside and outside. 2. A polyol supply path communicates between a polyol inlet provided in the mixing head body, a polyol outlet facing the chamber for forced stirring or an air mix chamber, and a polyol inlet and a polyol outlet. A diisocyanate supply path, a diisocyanate input port provided in the mixing head body, a diisocyanate discharge port facing the forced stirring chamber or the air mix chamber, and a diisocyanate input port. A diisocyanate flow passage communicating with the diisocyanate discharge port, wherein a stirring air supply path is provided in the mixing head main body, and a stirring air input port provided in the mixing head body, and the forced stirring chamber or the air mixing chamber is provided. And stirred an air discharge port facing the has a stirring air inlet and the stirring air discharge port and stirred an air passage for communicating the claim 1
An apparatus for mixing the polyurethane according to the above. 3. The polyurethane according to claim 1, wherein the shaft lead-out portion is formed of a cylindrical body connected to a lower portion of the mixing chamber of the air mix chamber so that the impeller fixing screw portion can be inserted therethrough. Mixing device.