JP6280841B2 - Foaming agent supply apparatus, polyurethane foam manufacturing apparatus, and foaming agent supply method - Google Patents

Description

  The present invention relates to a foaming agent supply device for supplying a physical foaming agent to one urethane stock solution of a first urethane stock solution containing a polyol as a main component and a second urethane stock solution containing a polyisocyanate as a main component, and a polyurethane foam provided with the same The present invention relates to a manufacturing apparatus and a foaming agent supply method.

  Conventionally, as this type of foaming agent supply device, by retracting the piston, a predetermined amount of physical foaming agent is sucked into the cylinder, and by moving the piston forward, the physical foaming agent in the cylinder is sent to the pressure feed path of the urethane stock solution. What is supplied is known. By the way, in such a foaming agent supply apparatus, when a physical foaming agent is attracted | sucked in a cylinder, a physical foaming agent vaporizes and the problem that the supply amount of a physical foaming agent is not stabilized arises. Therefore, in order to solve the above problem, a foaming agent supply device that suppresses vaporization of the physical foaming agent by cooling the cylinder has been proposed (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2006-29895 ([0019], FIG. 1)

  However, the above-described foaming agent supply device for cooling the cylinder has another problem that the size of the device is increased by the cooling device for the cylinder.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a foaming agent supply device capable of stabilizing the supply amount of a physical foaming agent and reducing the size of the device, a polyurethane foam manufacturing apparatus including the same, and a foaming agent supply method.

In order to achieve the above object, the foaming agent supply device according to the invention of claim 1 is one urethane stock solution of a first urethane stock solution containing polyol as a main component and a second urethane stock solution containing polyisocyanate as a main component. This is a foaming agent supply device that supplies a physical foaming agent to a stock solution pressure feed path that pumps the pressure, and stores the physical foaming agent in a pressurized state, and the pressure of one urethane stock solution in the stock solution pressure feed path. A foaming agent storage section having a pressure regulator for adjusting to a lower pressure, a cylinder having a first suction port, a second suction port and a discharge port, a metering pump having a piston which moves forward and backward in the cylinder, and a foaming agent storage A foaming agent introduction path connected to the first portion and the first suction port, a foaming agent introduction valve provided in the middle of the foaming agent introduction path, a discharge path connected to the discharge port and the raw liquid pressure feed path, and a raw liquid pressure feed Out discharge path A stock solution introduction path connected to a portion upstream of the connection portion and the second suction port, a stock solution introduction valve provided in the middle of the stock solution introduction path, a piston, a blowing agent introduction valve, and a stock solution introduction valve. Te, and a control unit for supplying the physical foaming agent, a control unit, carrying out the supply of the physical foaming agent, with closed before Symbol foaming agent inlet valve, the one open the stock solution inlet valve The urethane stock solution was introduced into the cylinder , the stock solution introduction valve was closed, the foaming agent introduction valve was opened, then the piston was retracted to suck the physical foaming agent into the cylinder, and the piston was preset. After the retraction, the foaming agent introduction valve is closed, and then the piston is advanced to discharge the mixed liquid of the physical foaming agent and the one urethane stock solution in the cylinder.

  A second aspect of the present invention is the blowing agent supply apparatus according to the first aspect, further comprising a pressure sensor for detecting the pressure in the stock solution introduction path or the pressure in the discharge path, and the control unit is detected by the pressure sensor It is characterized in that the physical foaming agent is supplied when the pressure is higher than the pressure of the physical foaming agent.

  A third aspect of the present invention is the foaming agent supply apparatus according to the first or second aspect, wherein the raw material check valve is provided in the middle of the stock solution introduction path to prevent backflow of one urethane stock solution, and the foaming agent introduction path. Provided with a foaming agent check valve which is provided in the middle of the physical foaming agent and prevents the backflow of the physical foaming agent.

  According to a fourth aspect of the present invention, there is provided the foaming agent supply device according to any one of the first to third aspects, wherein a temperature adjusting device for maintaining the physical foaming agent in a liquid state is provided in the middle of the foaming agent introduction path. It is characterized by where it is provided.

  A fifth aspect of the invention is characterized in that, in the foaming agent supply apparatus according to any one of the first to fourth aspects, the physical foaming agent is liquefied carbon dioxide.

  A sixth aspect of the present invention is the foaming agent supply apparatus according to any one of the first to fifth aspects, wherein a groove extending in the axial direction of the piston is formed on the outer peripheral surface of the front end of the piston. It has the characteristics.

The polyurethane foam manufacturing apparatus according to the invention of claim 7 includes a first raw solution pressure feed path for pumping the first urethane stock solution, a second stock solution pressure feed path for pumping the second urethane stock solution, a first stock solution pressure feed path, and a second stock solution. 7. The foaming agent supply device according to any one of claims 1 to 6, wherein one urethane stock solution is introduced into the cylinder from any one of the stock solution pressure feed passages, and the first stock solution pressure feed route. And one of the urethane stock solution after the physical foaming agent is supplied from the foaming agent supply device, and the other urethane stock solution of the first urethane stock solution and the second urethane stock solution. And a foaming device for producing a polyurethane foam by mixing.

The invention of claim 8 is the poly urethane foam manufacturing apparatus according to claim 7, the control unit of the blowing agent supply device, solution feed device for feeding one of urethane stock solution to be introduced into the cylinder on one of the stock solution pumping passage It is characterized in that the supply of the physical foaming agent is started after receiving the start signal from.

  According to a ninth aspect of the present invention, there is provided a foaming agent supply method using a piston-type metering pump in which a piston moves forward and backward in a cylinder, and a first urethane undiluted solution mainly composed of polyol and a polyisocyanate as a main component. A foaming agent supply method for supplying a physical foaming agent to a stock solution pressure feeding path for pumping one urethane stock solution with a second urethane stock solution, wherein the pressure of the physical foaming agent is determined from the pressure of one urethane stock solution in the stock solution pressure feeding path. While keeping the pressure low, one urethane stock solution is introduced into the cylinder, the piston is retracted to suck the physical foaming agent into the cylinder, then the piston is advanced, and the physical foaming agent and one urethane stock solution are introduced. This is characterized in that the mixed liquid is discharged into the raw solution pressure feeding path.

  According to a tenth aspect of the present invention, in the foaming agent supply method according to the ninth aspect, when the pressure of one urethane stock solution in the stock solution feeding path is higher than the pressure of the physical foaming agent, one urethane stock solution is introduced into the cylinder. It has a feature.

The invention of claim 11 is the foaming agent supply method according to claim 9 or 10, wherein the distance for retreating the piston is determined based on the pressure of the physical foaming agent and the pressure of one of the urethane stock solutions in the stock solution feed path. However, it has characteristics.

[Inventions of Claims 1, 7, 9]
In the present invention, the physical foaming agent is sucked into the cylinder after the one urethane undiluted solution is introduced into the cylinder from the undiluted solution pressure feed path for pumping one of the first urethane undiluted solution and the second urethane undiluted solution. . Here, since the pressure of one urethane stock solution flowing through the stock pressure feed path is higher than the pressure of the physical foaming agent, the pressure in the cylinder when the physical foaming agent is sucked is changed to the pressure of the physical foaming agent. It becomes possible to approach, and when the physical foaming agent is sucked, the physical foaming agent is prevented from being vaporized by negative pressure. As described above, according to the present invention, it is possible to suppress the vaporization of the physical foaming agent without cooling the cylinder, thereby stabilizing the supply amount of the physical foaming agent and reducing the size of the apparatus. Become. Further, since the physical foaming agent is supplied to the stock solution pressure feed path as a mixed solution with one urethane stock solution, it is possible to easily mix the physical foaming agent after the supply into one urethane stock solution.

[Inventions of Claims 2 and 10]
In the present invention of claim 2, the pressure sensor by detecting the pressure of the pressure or or the ejection Detchi of stock introduction passage, it is possible to detect one pressure urethane stock in stock pumping passage. According to the inventions of claims 2 and 10, since the physical foaming agent is supplied when the pressure detected by the pressure sensor is higher than the preset set pressure, the physical foaming agent is excessive in the cylinder. Suction is suppressed and the supply amount of the physical foaming agent is stabilized.

[Invention of claim 3]
According to invention of Claim 3, the backflow of a physical foaming agent and one urethane stock solution can be prevented with a simple structure.

[Invention of claim 4]
According to the invention of claim 4, it is possible to suppress the physical foaming agent from being vaporized before being introduced into the cylinder.

[Invention of claim 5]
According to invention of Claim 5, the cell diameter of a polyurethane foam is made small and the heat insulation effect of a polyurethane foam is improved.

[Invention of claim 6]
According to invention of Claim 6, it becomes possible to aim at the improvement of the mixing efficiency of the physical foaming agent and one urethane stock solution in a cylinder.

[Invention of Claim 8]
According to the eighth aspect of the present invention, it is possible to supply the physical foaming agent only when there is a request from the stock solution supply device that sends one urethane stock solution to one stock solution pressure feed path.

[Invention of Claim 11]
According to invention of Claim 11, the quantity of the physical foaming agent attracted | sucked in a cylinder is stabilized, and the supply amount of a physical foaming agent is stabilized.

Schematic which shows the polyurethane foam manufacturing apparatus which concerns on one Embodiment of this invention. (A) Side sectional view of metering pump, (B) AA sectional view (A) Side view, (B) BB cross-sectional view, (C) CC cross-sectional view of the tip small diameter part Block diagram of blowing agent supply equipment Flow chart of blowing agent supply program (A) The figure which shows the state of each valve and cylinder after initial setting, (B) The figure which shows the state of each valve and cylinder when a stock solution introduction valve closes (A) The figure which shows the state of each valve and cylinder when a piston starts retreating, (B) The figure which shows the state of each valve and cylinder when a piston retreats (A) The figure which shows the state of each valve and cylinder when a piston is arrange | positioned in a rear-end position, (B) The figure which shows the state of each valve and cylinder when a foaming agent introduction valve closes (A) The figure which shows the state of each valve and cylinder when a piston is moving forward, (B) The figure which shows the state of each valve and cylinder when a liquid mixture check valve opens

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the polyurethane foam manufacturing apparatus 10 of this embodiment includes a first stock solution supply device 11 for supplying a first urethane stock solution containing a polyol as a main component, and a second urethane stock solution containing a polyisocyanate as a main component. The second raw solution supply device 15 for supplying the foam, the foaming agent supply device 30 for supplying the physical foaming agent, and the foaming device 70 for producing the polyurethane foam by mixing the first urethane stock solution, the second urethane stock solution and the physical foaming agent. And.

  The first stock solution supply device 11 includes a first stock solution tank 12 that stores a first urethane stock solution, and a first stock solution pressure feed path 13 that extends from the first stock solution tank 12 and communicates with the foaming device 70. Then, the first stock solution supply device 11 pumps the first urethane stock solution from the first stock solution tank 12 to the first stock solution pressure feed path 13 by a pump (not shown), and continuously supplies the first urethane stock solution to the foaming device 70. The pressure of the first urethane stock solution flowing through the first stock solution pressure feed path 13 is, for example, 7 MPa.

  The second stock solution supply device 15 has the same configuration as the first stock solution supply device 11, and extends from the second stock solution tank 16 for storing the second urethane stock solution and the second stock solution tank 16 to communicate with the foaming device 70. The second undiluted solution pressure feed path 17 is provided. Then, the second stock solution supply device 15 pumps the second urethane stock solution from the second stock solution tank 16 to the second stock solution pressure feed path 17 by a pump (not shown), and continuously supplies the second urethane stock solution to the foaming device 70. In addition, the pressure of the 2nd urethane stock solution which flows through the 2nd stock solution pressure feed path 17 is 7 Mpa, for example.

  The foaming agent supply device 30 includes a foaming agent storage unit 32 that stores liquefied carbon dioxide as a physical foaming agent, a metering pump 40 that measures and discharges liquefied carbon dioxide, a foaming agent storage unit 32, and a metering pump 40. And a blowing agent introduction path 33 for connecting the two.

  The foaming agent reservoir 32 includes a cylinder 31 that stores pressurized liquefied carbon dioxide, and a regulator 31R that is attached to the supply port 31A of the cylinder 31 and adjusts the liquefied carbon dioxide under reduced pressure (in the “pressure regulator” of the present invention). Corresponding). In the present embodiment, the pressure of the liquefied carbon dioxide is adjusted to, for example, 5.6 MPa by the regulator 31R. The foaming agent introduction path 33 is connected to the regulator 31R.

  Between the foaming agent reservoir 32 and the metering pump 40, a manifold 34 constituting a part of the foaming agent introduction path 33 is disposed. The manifold 34 includes branch pipes 33 </ b> A and 33 </ b> B branched from the foaming agent introduction path 33, a temperature sensor 35, and a cooling device 36. The cooling device 36 cools so that the temperature of the manifold 34 becomes a set temperature. Thereby, it is suppressed that the liquefied carbon dioxide flowing through the blowing agent introduction path 33 is vaporized before being introduced into the metering pump 40.

  Of the branch pipes 33A and 33B, the upstream branch pipe 33A is connected to the pressure relief valve 37, and the downstream branch pipe 33B is connected to the blow valve 38. The pressure relief valve 37 is opened above the set pressure to keep the pressure in the foaming agent introduction passage 33 below the set pressure. The blow valve 38 releases liquefied carbon dioxide in the foaming agent supply device 30 in the open state.

  A foaming agent introduction valve 41 and a foaming agent check valve 42 are sequentially provided from the manifold 34 side on the downstream side of the manifold 34 in the foaming agent introduction path 33. The foaming agent introduction valve 41 is controlled to be opened and closed by a control unit 50 (see FIG. 4) described later. The foaming agent check valve 42 prevents the backflow of liquefied carbon dioxide from the metering pump 40 side to the foaming agent reservoir 32 side.

  As shown in FIGS. 2A and 2B, the metering pump 40 includes a cylinder 60 and a piston 65 that reciprocates within the cylinder 60. The cylinder 60 includes a first suction port 61A, a second suction port 61B, and a discharge port 62, and the above-described foaming agent introduction path 33 is connected to the first suction port 61A. Specifically, a linearly extending pressure chamber 60A is formed in the cylinder 60, and a first suction port 61A, a second suction port 61B, and a cross hole 60B intersecting with one end of the pressure chamber 60A are provided. The discharge port 62 communicates. The piston 65 is in sliding contact with the inner peripheral surface of the pressure chamber 60A, and the tip of the piston 65 moves linearly between one end and the other end of the pressure chamber 60A.

  Specifically, the piston 65 has a stepped structure in which a tip small-diameter portion 67 protrudes from the tip of the large-diameter portion 66, and the cylinder 60 has a large-diameter portion that communicates with the other end of the pressure chamber 60 </ b> A. A receiving chamber 63 for receiving 66 is formed. The piston 65 is normally disposed at a front end position (see FIG. 6A) where the front end surface 66M of the large-diameter portion 66 contacts the wall surface 63M on the front end side of the receiving chamber 63. Note that the tip small-diameter portion 67 slightly enters the cross hole 60B in a state where the piston 65 is disposed at the front end position.

  The piston 65 moves backward from the front end position in a direction away from the cross hole 60B by a predetermined distance and is disposed at the rear end position (see FIG. 8B). In the metering pump 40 of this embodiment, as will be described in detail later, when the piston 65 moves backward from the front end position to the rear end position, a predetermined amount of liquefied carbon dioxide is sucked into the cylinder 60 from the first suction port 61A. Then, when the piston 65 moves forward from the retracted position to the front end position, the sucked liquefied carbon dioxide is discharged from the discharge port 62. The axial lengths of the distal small diameter portion 67 and the pressure chamber 60A are set so that the distal end portion of the distal small diameter portion 67 is received in the pressure chamber 60A in a state where the piston 65 is disposed at the rear end position. ing.

  FIG. 3 shows the detailed structure of the tip small diameter portion 67. As shown in FIG. 3A, a plurality of longitudinal grooves 68 extending in the axial direction are formed on the outer peripheral surface of the distal end portion of the distal end small diameter portion 67. In the example of FIG. 3, the distal end small-diameter portion 67 includes a plurality of first longitudinal grooves 68A communicating with the distal end surface 67M and a plurality of second longitudinal grooves arranged on the proximal end side from the plurality of first longitudinal grooves 68A. A groove 68B is formed. As shown in FIGS. 3B and 3C, the first vertical groove 68A and the second vertical groove 68B are arranged at positions shifted in the circumferential direction. 2 and 6-9, the longitudinal groove 68 is not shown.

  As shown in FIG. 2, a discharge path 49 is connected to the discharge port 62 of the cylinder 60. As shown in FIG. 1, the discharge passage 49 is connected to the first raw liquid pressure feed path 13, whereby liquefied carbon dioxide measured by the metering pump 40 is added to the first urethane raw liquid flowing through the first raw liquid pressure feed path 13. Supplied. A mixed liquid check valve 48 that prevents backflow to the metering pump 40 is provided in the middle of the discharge passage 49.

  Incidentally, in the foaming agent supply device 30 of the present embodiment, as shown in FIG. 1, the upstream portion of the first raw solution pressure feed path 13 from the connection portion with the discharge path 49 and the second suction port 61 </ b> B of the cylinder 60. A stock solution introduction path 45 is provided. Accordingly, in the present embodiment, the first urethane stock solution is introduced into the pressure chamber 60 </ b> A of the cylinder 60 in addition to the liquefied carbon dioxide.

  In the middle of the stock solution introduction path 45, a stock solution introduction valve 43 and a stock solution check valve 44 are arranged in this order from the stock solution pressure feed path 13 side. The stock solution introduction valve 43 is controlled to be opened and closed by the control unit 50 (see FIG. 4) in the same manner as the foaming agent introduction valve 41 described above.

  Further, as shown in FIG. 1, a manifold 46 that constitutes a part of the stock solution introduction path 45 and a part of the discharge path 49 is disposed between the first stock solution pressure feed path 13 and the metering pump 40. Has been. The manifold 46 is provided with a pressure sensor 47 that detects the pressure in the discharge passage 49. The stock solution introduction valve 43 and the stock solution check valve 44 are disposed on the downstream side of the manifold 46 in the stock solution introduction path 45, and the mixed solution check valve 48 is disposed on the upstream side of the manifold 46 in the discharge path 49. .

  FIG. 4 shows an electrical configuration of the foaming agent supply device 30. As shown in the figure, the foaming agent supply device 30 is provided with a control unit 50 having an introduction valve control unit 51, a pump control unit 52, a temperature control unit 53, and a reception unit 58.

  The temperature control unit 53 receives the temperature signal detected by the temperature sensor 35 and controls the cooling device 36 via the drive circuit 57. Specifically, the temperature control unit 53 turns on the cooling device 36 if the temperature detected by the temperature sensor 35 is higher than the set temperature, and turns off the cooling device 36 if the detected temperature is equal to or lower than the set temperature.

  The pump control unit 52 drives and controls the metering pump 40. Specifically, the pump control unit 52 drives the piston 65 via the drive circuit 56 based on the position of the piston 65 detected by the position sensor 65S. The position sensor 65S is disposed in the metering pump 40.

  The introduction valve control unit 51 controls opening and closing of the foaming agent introduction valve 41 and the stock solution introduction valve 43. Specifically, the introduction valve control unit 51 detects the pressure in the discharge passage 49 detected by the pressure sensor 47, that is, the liquid pressure of the mixed liquid of liquefied carbon dioxide and the first urethane stock solution, and the position sensor 65S. The foaming agent introduction valve 41 and the stock solution introduction valve 43 are opened and closed via the drive circuits 54 and 55 based on the position of the piston 65.

  The receiving unit 58 receives a start signal for requesting the supply of liquefied carbon dioxide from a stock solution supply device that pumps the urethane stock solution introduced into the cylinder 60 of the metering pump 40 to the stock solution pressure feed path. The first undiluted solution supply device 11 and the second undiluted solution supply device 15 are each provided with a piston type pump for sending the urethane undiluted solution to the first undiluted solution pressure feed path 13 and the second undiluted solution pressure feed path 17, and are provided at the moving end of the piston. The piston position is detected by the sensor, and a start signal is transmitted at the timing when the piston completes the delivery. The start signal may be transmitted every time a certain amount of urethane stock solution is sent out. In this embodiment, since the urethane stock solution introduced into the cylinder 60 is the first urethane stock solution, the start signal is transmitted from the first stock solution supply device 11.

  FIG. 5 shows a blowing agent supply program PG1 executed by the control unit 50 when the blowing agent supply device 30 supplies liquefied carbon dioxide. The foaming agent supply program PG1 is executed when the power of the foaming agent supply device 30 is turned on. As shown in the figure, when the blowing agent supply program PG1 is executed, the control unit 50 first performs an initial setting (S11). In this initial setting (S11), the foaming agent introduction valve 41 is closed, the stock solution introduction valve 43 is opened, and the piston 65 is disposed at the front end position. At this time, the first urethane stock solution flowing through the stock solution introduction path 45 is introduced into the cylinder 60 from the second suction port 61B, and returned from the discharge port 62 to the first stock solution pressure feed path 13 through the discharge path 49. The initial setting (S11) is executed only once when the power of the foaming agent supply device 30 is turned on.

  When the initial setting (S11) is completed, the control unit 50 determines whether or not a start signal for requesting the supply of liquefied carbon dioxide is received from the first stock solution supply device 11 (S12). If the start signal has not been received (No in S12), this determination (S12) is performed again.

  If the start signal has been received (Yes in S12), it is then determined whether or not the pressure detected by the pressure sensor 47, that is, the pressure of the first urethane stock solution flowing through the discharge passage 49 is higher than the set pressure. (S13). Here, the set pressure is set to be the same as the pressure of liquefied carbon dioxide (5.6 MPa). If the detected pressure is equal to or lower than the set pressure (No in S13), the process returns to step S12.

  When the detected pressure is higher than the set pressure (Yes in S13), the stock solution introduction valve 43 is closed (S14), the foaming agent introduction valve 41 is opened (S15), and then the piston 65 is retracted to the rear end position (S14). S16). The distance from the front end position to the rear end position is set manually or automatically based on the pressure P1 of the first urethane stock solution and the pressure P2 of the liquefied carbon dioxide in the first stock solution pressure feed path 13.

  When the piston 65 reaches the rear end position, the foaming agent introduction valve 41 is closed (S17), and the piston 65 is advanced to the front end position (S18). When the piston 65 reaches the front end position, the stock solution introduction valve 43 is opened (S19), and the process returns to step S12.

6 to 9 show the states of the introduction valves 41 and 43 and the cylinder 65 when the control unit 50 executes steps S14 to S19 in the foaming agent supply program PG1. Before the control unit 50 receives the start signal from the first stock solution supply device 11, as shown in FIG. 6A, the foaming agent introduction valve 41 is closed, the stock solution introduction valve 43 is opened, and the piston 65 is in the front end position. Is arranged. At this time, the internal pressure P of the cylinder 60 becomes equal to the pressure P1 in the first raw liquid pressure feed path 13, and the raw liquid check valve 44 and the mixed liquid check valve 48 are both opened. Accordingly, the first urethane stock solution flowing from the first stock solution pressure feed passage 13 to the stock solution introduction passage 45 is introduced into the cylinder 60 from the second suction port 61B. Specifically, if the internal pressure P of the pressure chamber 60A of the cylinder 60 is lower than the pressure P1 in the first raw liquid pressure feed path 13, the mixed liquid check valve 48 is closed and the raw liquid check valve 44 is opened. Will eventually become equal to the pressure P1 in the first undiluted solution pressure feed path 13, and the undiluted solution check valve 44 and the mixed solution check valve 48 will both open. Further, if the internal pressure P of the pressure chamber 60A is higher than the pressure P1 of the first stock solution pressure feed path 13, the stock solution check valve 44 is closed and the mixed solution check valve 48 is opened. The pressure becomes equal to the pressure P1 in the first raw liquid pressure feed path 13, and both the raw liquid check valve 44 and the mixed liquid check valve 48 are opened.

  When the control unit 50 executes step S14 of the blowing agent supply program PG1, as shown in FIG. 6B, the stock solution introduction valve 43 is closed. At this time, the internal pressure P in the pressure chamber 60 </ b> A of the cylinder 60 remains equal to the pressure P <b> 1 in the first raw liquid pressure feed path 13.

  Next, when the control unit 50 executes step S15 of the foaming agent supply program PG1, the foaming agent introduction valve 41 is opened as shown in FIG. Here, the pressure P2 of the liquefied carbon dioxide is adjusted to a lower pressure (for example, 5.6 MPa) than the pressure P1 (for example, 7 MPa) in the first raw liquid pressure feed path 13 by the regulator 31R (see FIG. 1). The foaming agent check valve 42 is closed.

  Next, when the control unit 50 executes step S16 of the blowing agent supply program PG1, as shown in FIG. 7B, the piston 65 moves backward, and the internal pressure P of the pressure chamber 60A decreases. When the internal pressure P of the pressure chamber 60A becomes equal to the pressure P2 of liquefied carbon dioxide, the foaming agent check valve 42 is opened, and liquefied carbon dioxide is sucked into the pressure chamber 60A from the first suction port 61A. The first urethane stock solution and liquefied carbon dioxide are mixed. Then, as shown in FIG. 8A, when the piston 65 moves backward to the rear end position, a predetermined amount of liquefied carbon dioxide is sucked into the pressure chamber 60A. 7B to 8A, the internal pressure P of the pressure chamber 60A is lower than the pressure P1 in the first raw liquid pressure feed path 13, so the mixed liquid check valve 48 is closed. Yes.

  Next, when the control unit 50 executes step S17 of the foaming agent supply program PG1, the foaming agent introduction valve 41 is closed as shown in FIG. 8B. At this time, the internal pressure P of the pressure chamber 60A is equal to the pressure P2 of the liquefied carbon dioxide.

  Next, when the control unit 50 executes step S18 of the foaming agent supply program PG1, as shown in FIG. 9A, the piston 65 moves forward and the internal pressure P of the pressure chamber 60A increases. When the internal pressure P of the pressure chamber 60A becomes equal to the pressure P1 in the first raw liquid pressure feed passage 13, as shown in FIG. 9B, the mixed liquid check valve 48 opens, and the first urethane raw liquid in the pressure chamber 60A and A liquid mixture of liquefied carbon dioxide is discharged from the discharge port 62. When the piston 65 moves forward to the front end position, a mixed liquid obtained by mixing a predetermined amount of liquefied carbon dioxide and the first urethane stock solution is supplied to the first stock solution pressure feed passage 13 through the discharge passage 49.

  Next, when the control unit 50 executes step S19 of the foaming agent program PG1, the stock solution introduction valve 43 is opened, and the state returns to the state shown in FIG.

  The description regarding the structure of the foaming agent supply apparatus 30 and the polyurethane foam manufacturing apparatus 10 of this embodiment is above. Next, the effect of the foaming agent supply apparatus 30 and the polyurethane foam manufacturing apparatus 10 is demonstrated.

In the present embodiment, after the first urethane stock solution is introduced into the cylinder 60 from the first stock solution feed path 13 for feeding the first urethane stock solution, liquefied carbon dioxide as a physical foaming agent is sucked into the cylinder 60. Here, since the pressure P1 of the first urethane stock solution flowing through the stock solution pressure feed path 13 is higher than the pressure P2 of the liquefied carbon dioxide, the pressure P in the cylinder 60 when the liquefied carbon dioxide is sucked is liquefied. It becomes possible to approach the pressure P2 of carbon dioxide, and vaporization of liquefied carbon dioxide due to negative pressure when liquefied carbon dioxide is sucked is suppressed. As described above, according to this embodiment, it is possible to suppress the vaporization of liquefied carbon dioxide without cooling the cylinder 60, thereby stabilizing the supply amount of liquefied carbon dioxide and reducing the size of the apparatus. It becomes possible. Moreover, since liquefied carbon dioxide is supplied to the 1st stock solution pressure feed path 13 as a liquid mixture with the 1st urethane stock solution, it becomes possible to make it easy to mix liquefied carbon dioxide after supply with the 1st urethane stock solution .

  Further, in the present embodiment, the pressure sensor 47 detects the pressure in the discharge passage 49, whereby the pressure of the first urethane stock solution flowing through the first stock solution pressure feed passage 13 can be detected. In the present embodiment, the control unit 50 supplies liquefied carbon dioxide when the pressure detected by the pressure sensor 47 is higher than the pressure P2 of liquefied carbon dioxide. The amount of liquefied carbon dioxide supplied can be stabilized by suppressing the suction of the liquefied carbon dioxide.

  Furthermore, in the present embodiment, since the longitudinal groove 68 extending in the axial direction is formed on the outer peripheral surface of the tip small diameter portion 47, the mixing efficiency of the liquefied carbon dioxide and the first urethane stock solution in the cylinder 60 is improved. Can be achieved.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various modifications are possible within the scope of the invention other than the following. It can be changed and implemented.

  (1) In the above embodiment, liquefied carbon dioxide as a physical foaming agent was mixed with the first urethane stock solution mainly composed of polyol, but mixed with the second urethane stock solution mainly composed of polyisocyanate. Alternatively, it may be mixed with each of the urethane stock solutions. In addition, when mixing into both undiluted | stock solutions, the foaming agent supply apparatus 30 which mixes a liquefied carbon dioxide with the 1st urethane undiluted solution drawn from the 1st undiluted solution pressure feed path 13, and supplies it to the 1st undiluted solution feed path 13; It is good also as a structure provided with the foaming agent supply apparatus 30 which mixes a liquefied carbon dioxide with the 2nd urethane stock solution drawn in from the stock solution pressure feed path 17, and supplies it to the 2nd stock solution pressure feed path 17. FIG. Moreover, the foaming agent supply apparatus 30 mixes liquefied carbon dioxide with the 1st urethane undiluted solution, supplies it to the 1st undiluted solution pressure feed path 13, and mixes liquefied carbon dioxide with the 2nd urethane undiluted solution, and the 2nd undiluted solution It is good also as a structure provided with two types of metering pumps 40 of the metering pump 40 supplied to the pressure feed path 17. FIG.

  (2) In the above embodiment, liquefied carbon dioxide is exemplified as the physical foaming agent, but an inert gas such as Freon or HFO (hydrofluoroolefin) may be used. In the above embodiment, the use of liquefied carbon dioxide reduces the cell diameter of the polyurethane foam and improves the heat insulation effect. In addition, since the initial foaming characteristics (foaming characteristics) are good, it is possible to reduce the raw materials used.

  (3) In the above embodiment, the tip small diameter portion 67 of the piston 65 is configured to include the vertical groove 68 at the tip portion, but may be configured not to include the vertical groove 68. Moreover, in the said embodiment, it is good also as a structure provided with only the 1st vertical groove 68A in the front-end | tip small diameter part 67. FIG.

  (4) In the above embodiment, the pressure sensor 47 is configured to detect the pressure in the discharge passage 49, but may be configured to detect the pressure in the stock solution introduction passage 45.

  (5) The above embodiment includes a sensor that detects opening and closing of the foaming agent check valve 42, and when the piston 65 is retracted, the piston 65 is retracted by a set distance from when the foaming agent check valve 42 is opened. It is good.

DESCRIPTION OF SYMBOLS 10 Polyurethane foam manufacturing apparatus 11 1st undiluted solution supply apparatus 13 1st undiluted solution pressure feed path 15 2nd undiluted solution supply apparatus 17 2nd undiluted solution pressure feed path 30 Foaming agent supply apparatus 31R Regulator (pressure regulator)
32 Foaming agent storage unit 33 Foaming agent introduction path 40 Metering pump 41 Foaming agent introduction valve 43 Stock solution introduction valve 45 Stock solution introduction passage 49 Discharge passage 50 Control unit 70 Foaming device

Claims (11)

A foaming agent supply device for supplying a physical foaming agent to a raw solution pumping path for pumping one urethane stock solution of a first urethane stock solution containing a polyol as a main component and a second urethane stock solution containing a polyisocyanate as a main component,
While storing the physical foaming agent in a pressurized state, a foaming agent storage unit having a pressure regulator that adjusts the pressure of the physical foaming agent to a pressure lower than the pressure of the one urethane stock solution in the stock solution pressure feeding path;
A metering pump having a cylinder having a first suction port, a second suction port, and a discharge port; and a piston that moves forward and backward in the cylinder;
A blowing agent introduction path connected to the blowing agent reservoir and the first suction port;
A foaming agent introduction valve provided in the middle of the foaming agent introduction path;
A discharge path connected to the discharge port and the stock solution pressure feed path;
A stock solution introduction passage connected to a portion upstream of the connection portion with the discharge passage and the second suction port of the stock solution pressure feed passage;
A stock solution introduction valve provided in the middle of the stock solution introduction path;
A controller that controls the piston, the foaming agent introduction valve, and the stock solution introduction valve to supply the physical foaming agent,
The control unit, carrying out the supply of the physical foaming agent, in a state where front Symbol closed foaming agent inlet valve, the urethane stock solution of the one open the stock solution introduction valve from by introduced into the cylinder, the Close the stock solution introduction valve, open the foaming agent introduction valve, then retract the piston to suck the physical foaming agent into the cylinder, retract the piston by a preset distance, A foaming agent supply apparatus, wherein the foaming agent introduction valve is closed, and then the piston is advanced to discharge the mixed liquid of the physical foaming agent and the one urethane stock solution in the cylinder. A pressure sensor for detecting the pressure in the stock solution introduction path or the pressure in the discharge path;
2. The foaming agent supply device according to claim 1, wherein the control unit supplies the physical foaming agent when a pressure detected by the pressure sensor is higher than a pressure of the physical foaming agent. A stock solution check valve provided in the middle of the stock solution introduction path to prevent backflow of the one urethane stock solution;
The foaming agent supply device according to claim 1, further comprising a foaming agent check valve that is provided in the middle of the foaming agent introduction path and prevents a backflow of the physical foaming agent.   The blowing agent supply according to any one of claims 1 to 3, wherein a temperature adjusting device for maintaining the physical blowing agent in a liquid state is provided in the middle of the blowing agent introduction path. apparatus.   The foaming agent supply device according to any one of claims 1 to 4, wherein the physical foaming agent is liquefied carbon dioxide.   The foaming agent supply device according to any one of claims 1 to 5, wherein a groove extending in an axial direction of the piston is formed on an outer peripheral surface of a tip portion of the piston. A first stock solution pumping path for pumping the first urethane stock solution;
A second stock solution pumping path for pumping the second urethane stock solution;
The invention according to any one of claims 1 to 6, wherein the one urethane stock solution is introduced into the cylinder from one of the first stock solution pressure feed route and the second stock solution pressure feed route. The blowing agent supply device according to claim,
Connected to the first stock solution pressure feed path and the second stock solution pressure feed path, the one urethane stock solution after the physical foaming agent is supplied from the foaming agent supply device, the first urethane stock solution and the first 2. A polyurethane foam manufacturing apparatus comprising: a foaming apparatus that mixes the other urethane stock solution of two urethane stock solutions to produce a polyurethane foam.   The control unit of the foaming agent supply device receives a start signal from the stock solution supply device that sends the one urethane stock solution introduced into the cylinder to the one stock solution pressure feeding path, and then the physical foaming agent 8. The polyurethane foam manufacturing apparatus according to claim 7, wherein the supply is started. Using a piston-type metering pump in which the piston moves forward and backward in the cylinder, one urethane stock solution is pumped out of the first urethane stock solution mainly composed of polyol and the second urethane stock solution mainly composed of polyisocyanate. A foaming agent supply method for supplying a physical foaming agent to a stock solution pressure feeding path,
While keeping the pressure of the physical foaming agent lower than the pressure of the one urethane stock solution in the stock solution pressure feed path, the one urethane stock solution is introduced into the cylinder,
The piston is retracted to suck the physical foaming agent into the cylinder, and then the piston is advanced to discharge the mixed liquid of the physical foaming agent and the one urethane stock solution to the stock solution pressure feeding path. A method of supplying a foaming agent.   10. The foaming agent according to claim 9, wherein the one urethane stock solution is introduced into the cylinder when the pressure of the one urethane stock solution in the stock solution pressure feeding path is higher than the pressure of the physical foaming agent. Supply method.   The method for supplying a foaming agent according to claim 9 or 10, wherein a distance for retreating the piston is determined based on a pressure of the physical foaming agent and a pressure of the one urethane stock solution in the stock solution pressure feeding path. .

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