Structure of discharge part of foaming device and foaming device

Abstract

[Problem] To prevent or suppress dripping of a foamable material discharged from a discharge part. [Solution] A discharge part 45 has an inlet part 46, an outlet part 47, a space formation part 49, and a valve body 48. A distance d2 from the outlet part to a proximity portion of the valve body in a state where the inlet part is not in communication with the outlet part is shorter than a distance d1 from the inlet part to the proximity portion of the valve body.

Description

Structure of the discharge part of a foaming device and the foaming device

[0001] The present invention relates to the structure of the discharge part of a foaming device and the foaming device.

[0002] Conventionally, as industrial sealing materials and vibration damping materials, a foamed material in which gas is mixed into a liquid such as a liquid resin and bubbles are dispersed in the liquid is foamed and then cured or solidified. As methods for generating the foamed material, chemical foaming in which two liquids of a main agent and a curing agent are mixed and chemically foamed, and mechanical foaming in which gas is mechanically mixed into a one-component liquid are known. Also, among chemical foaming, there is a type of heat foaming agent that generates gas by heating.

[0003] In chemical foaming, since a chemical reaction is utilized, it is difficult to control the foaming ratio due to the influence of environmental factors such as temperature, humidity, and the mixing state of two or more types of liquid agents. On the other hand, in mechanical foaming, since gas is mechanically mixed, it is less affected by environmental factors, and the foaming ratio can be controlled relatively easily. Therefore, for sealing materials and vibration damping materials such as electronic components and automotive parts that require more precise control of the foaming ratio, it is desirable to use mechanical foaming.

[0004] Mechanical foaming devices mainly include a plunger pump type and a gear pump type. The gear pump type can quantitatively deliver liquid, so it is easier to control the foaming ratio compared to the plunger pump type.

[0005] For example, Patent Document No. 1 below discloses a gear pump type mechanical foaming device including two gear pumps arranged in a flow path through which a liquid resin is delivered, and a gas supply unit that supplies gas into the flow path through an air intake provided in the flow path between the two gear pumps.

[0006] Japanese Patent Application Laid-Open No. 2005-152710

[0007] In foaming devices, foaming material is discharged from a nozzle-like part. The inventors are diligently studying techniques to prevent or suppress dripping of the foaming material discharged from the discharge section. The inventors believe that the reason bubbles do not expand inside the device is that the internal pressure is high, and as the pressure approaches atmospheric pressure after passing through the valve, the gas expands, the bubbles become larger, the volume of the resin increases, and dripping occurs.

[0008] The present invention aims to prevent or suppress dripping of foamed material discharged from a dispensing unit.

[0009] One aspect of the present invention that achieves the above objective is the structure of the discharge section of a foaming device having an inlet, an outlet, a space-forming section, and a valve body. The inlet is configured to allow foaming material, which is a viscous material mixed with gas, to flow in. The outlet is configured to allow the foaming material to flow out and to be elongated so that the foaming material can be discharged in a curtain-like manner. The space-forming section is configured to form an internal space provided between the inlet and the outlet. The valve body is operably housed in the internal space and is configured to prevent the foaming material from being discharged from the outlet by not communicating with the outlet, and to allow the foaming material to be discharged by communicating with the outlet. The distance from the outlet to the nearest part of the valve body when the inlet is not communicating with the outlet is shorter than the distance from the inlet to the nearest part of the valve body.

[0010] One aspect of the present invention is a foaming apparatus having a flow path, a material supply unit, a gas supply unit, a first pump unit, a second pump unit, and the discharge unit. The flow path is configured to allow the viscous material to flow through. The material supply unit is configured to supply the viscous material to the flow path. The gas supply unit is configured to supply gas to the flow path. The first pump unit is configured to be positioned in the middle of the flow path. The second pump unit is positioned downstream of the first pump unit in the flow path and generates a suction pressure for producing foaming material.

[0011] According to the structure of the discharge section of the foaming apparatus and the foaming apparatus described above, it is possible to prevent or suppress dripping of the foaming material discharged from the discharge section.

[0012] This is a schematic diagram showing a foaming apparatus according to an embodiment. This is a schematic diagram showing the details of the discharge section of Figure 1, indicating that the inlet and outlet sections are connected. This is a schematic diagram showing the discharge section of Figure 2, indicating that the inlet and outlet sections are not connected. This is a flowchart explaining the mechanical foaming method. This is a schematic diagram showing modification 1 of the discharge section, indicating that the inlet and outlet sections are connected. This is a schematic diagram showing the discharge section of Figure 5, indicating that the inlet and outlet sections are not connected. This is a schematic diagram showing modification 2 of the discharge section. This is a schematic diagram showing modification 3 of the discharge section.

[0013] Embodiments of the present invention will be described below with reference to the attached drawings. Note that the following description does not limit the technical scope or the meaning of terms described in the claims. Furthermore, the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from actual ratios.

[0014] (Foamable Material) The foamable material obtained by the foaming apparatus 100 and mechanical foaming method according to this embodiment is produced when gas G is mixed into a liquid resin R (corresponding to a viscous material), and the gas G foams (expands) by dispersing the bubbles in the liquid viscous material.

[0015] Applications for foamed materials include, for example, sealing materials for waterproofing and dustproofing electronic components and cylinder head covers and oil pans in automobiles where airtightness is required. In addition to the above, applications for foamed materials include panels in automobile engine compartments where cushioning is required, potting of electronic components, and soundproofing, vibration damping, and heat insulation materials for housing cases.

[0016] In this specification, a mixture in which gas G is mixed with liquid resin R and gas bubbles are dispersed in the liquid resin R is referred to as a foaming material, and the state in which the foaming material is discharged from the foaming device 100 into the atmosphere and gas G is foamed is referred to as a foam. Furthermore, the liquid resin R before curing or solidification is simply referred to as resin R. Note that the state in which "gas is mixed with resin" includes a state in which resin and gas exist alternately in the piping and a state in which the gas is finely dispersed in the resin.

[0017] Examples of resin R include room-temperature curable compositions such as moisture-curing and two-component mixtures, heat-curable compositions, and photocurable compositions such as ultraviolet light and visible light. Resin R may also be a thermoplastic resin that melts upon heating and solidifies upon cooling at room temperature. Resin R includes materials that cure, crosslink, or solidify from a fluid state. Examples of resins include silicone resins, modified silicone resins, acrylic resins, urethane acrylate resins, epoxy resins, polyurethane resins, polyesters, polypropylenes, polyethylenes, polycarbonates, synthetic rubbers, natural rubbers, synthetic resins, and natural resins. Resin R also includes materials referred to as elastomers.

[0018] For example, nitrogen gas, carbon dioxide gas, air, etc., can be suitably used as gas G.

[0019] (Mechanical Foaming Device) Figure 1 shows a schematic overview of the foaming device 100. The foaming device 100 mixes gas G with resin R to generate a foamable material in which bubbles are dispersed in the liquid resin R, and then discharges this foamable material to foam it and produce a foam.

[0020] The foaming apparatus 100 according to this embodiment, as outlined with reference to Figure 1, includes a material supply unit 20, a pump unit 30, a mixer 41, a discharge unit 45, and a control unit 60. Each part of the apparatus is connected by piping 10 that constitutes a flow path for delivering resin R and gas G. In this specification, the side where the material supply unit 20 is located is referred to as the upstream side, and the side where the mixer 41 is located is referred to as the downstream side.

[0021] (Piping) Piping 10 is used to circulate resin R and gas G. As shown in Figure 1, piping 10 includes a first pipe 11, a second pipe 12, a third pipe 13, a fourth pipe 14 (corresponding to the first region), and a fifth pipe 15.

[0022] The first pipe 11 connects the material supply unit 20 and the first gear pump 31 of the pump unit 30. The second pipe 12 connects the first gear pump 31 and the second gear pump 33 in the pump unit 30.

[0023] The third pipe 13 connects the gas supply unit 32 and the second pipe 12. The fourth pipe 14 connects the second gear pump 33 and the mixer 41, which constitute the pump unit 30.

[0024] The fifth pipe 15 connects the mixer 41 and the discharge section 45. Although the diameters of each pipe from the first pipe 11 to the fifth pipe 15 are uniform, for example, an on-off valve 34 may be provided on the second pipe 12 at a position close to the second gear pump 33. This configuration makes it easier to draw gas from the gas supply section 32, which will be described later. In addition, the foaming ratio can be stabilized by providing a nozzle smaller than the diameter of the pipe.

[0025] The material used to form the piping is not particularly limited as long as it is a material that is not easily deformed by the pressure inside the piping 10. For example, metals such as SUS can be suitably used.

[0026] (Material Supply Unit) The material supply unit 20 supplies resin R to the piping 10. As shown in Figure 1, the material supply unit 20 is connected to the first gear pump 31 of the pump unit 30 via the first piping 11. The material supply unit 20 consists of, for example, a tank for storing resin R, a pump for pumping resin R, a replaceable cartridge, a pail, etc.

[0027] (Pump section) As shown in Figure 1, the pump section 30 includes a first gear pump 31 (corresponding to the first pump section), a gas supply section 32, a second gear pump 33 (corresponding to the second pump section), an on-off valve 34, and a first pressure sensor 35.

[0028] The first gear pump 31 is positioned in the middle of the piping 10. Specifically, the first gear pump 31 is positioned downstream of the material supply unit 20.

[0029] (Gas supply unit) The gas supply unit 32 is located between the first gear pump 31 and the second gear pump 33 and supplies gas G to the second pipe 12 and the third pipe 13 which constitute the piping 10.

[0030] The gas supply unit 32 supplies gas G to the piping 10. The gas supply unit 32 pressurizes gas G at a predetermined pressure or at atmospheric pressure and pumps it to the second piping 12 and the third piping 13. The gas supply unit 32 includes a gas tank for storing gas G and a gas supply port provided to discharge gas G from the gas tank to the second piping 12. The gas supply unit 32 uses the suction pressure generated in the second piping 12 during the discharge operation as the suction pressure for drawing in gas G to supply gas G to the second piping 12. By adjusting the pressure of the gas G supplied from the gas supply unit 32, the foaming ratio of the bubbles can be adjusted.

[0031] The second pipe 12 is equipped with an intake port that allows gas G supplied from the gas supply unit 32 to flow into the pipe 10. A portion of the flow path of the second pipe 12 is configured such that resin R and gas G are mixed (including a state in which resin R and gas G are not mixed).

[0032] The second gear pump 33 is positioned downstream of the first gear pump 31 in the piping 10. The second gear pump 33 is driven to rotate at a higher speed than the first gear pump 31, thereby generating suction pressure to introduce gas into the piping 10 and sending the resin R containing gas G to the downstream side of the piping 10.

[0033] The first gear pump 31 and the second gear pump 33 can be constructed using known gear pumps that have gears and transport fluid using the space between the teeth of each gear. The first gear pump 31 and the second gear pump 33 each include a drive gear and a driven gear that rotates in accordance with the drive gear.

[0034] The drive gear of the first gear pump 31 is configured to be driven by motor M1. The drive gear of the second gear pump 33 is configured to be driven by motor M2.

[0035] Gear pumps provide a constant and stable fluid flow rate, and the fluid flow rate can be adjusted relatively easily by adjusting the rotational speed of the gears. For example, an external gear pump with two gears that rotate simultaneously through meshing teeth can be used.

[0036] During discharge, the second gear pump 33 is driven to rotate at a higher speed than the first gear pump 31. The amount (volume) that flows out of the second pipe 12 by the second gear pump 33 is greater than the amount (volume) that flows into the second pipe 12 by the first gear pump 31. As a result, suction pressure is generated in the second pipe 12 in proportion to the volume lost due to the reduction in the amount of resin R.

[0037] The on-off valve 34 is configured to switch the communication state between the second pipe 12 and the gas supply unit 32. The on-off valve 34 is positioned between the gas supply port of the gas supply unit 32 and the second pipe 12 and is configured to open and close the intake port.

[0038] The on-off valve 34 is configured to include a known needle valve. The on-off valve 34 comprises a needle-shaped valve body to which a biasing force is applied in the closing direction to close the intake port, a piston connected to the valve body that moves the valve body in the opening direction to open the intake port, and a cylindrical portion that forms a housing space for housing the valve body and the piston. The housing space of the cylindrical portion communicates the gas supply port and the second piping 12 via the intake port. The on-off valve 34 may also be configured with a suck-back valve or a ball valve in addition to the above.

[0039] During the discharge operation, as shown in Figure 1, the first gear pump 31, the gas supply unit 32, and the second gear pump 33 are driven, and the on / off valve 34 is opened to send the viscous material containing gas to the mixer 41.

[0040] The first pressure sensor 35 is configured to measure (detect) the inter-pump pressure P1 (corresponding to the first pressure) between the first gear pump 31 and the second gear pump 33 in the second piping 12.

[0041] The mixer 41 is located downstream of the second gear pump 33 in the piping 10 and agitates the resin R containing gas G delivered by the second gear pump 33 to generate bubbles, and disperses the bubbles in the resin R into the liquid resin R to produce a foaming material. The mixer 41 is located downstream of the second gear pump 33 in the piping 10 and is positioned between the pump section 30 and the discharge section 45. As shown in Figure 1, the mixer 41 comprises a housing 41a and a rotor 41b.

[0042] As shown in FIG. 1, the housing 41a includes an inlet portion (not shown), an outlet portion (not shown), a mixing chamber (not shown), and a housing protrusion 41c. The inlet portion is configured to allow the resin R containing the gas G to flow in from the pipe 10. The outlet portion is configured to send the foaming material to the discharge portion 45. The mixing chamber is disposed between the inlet portion and the outlet portion and forms a space for mixing the resin R containing the gas.

[0043] A plurality of housing protrusions 41c are provided on the inner wall surface of the housing that forms the mixing chamber. The housing protrusions 41c are configured to be arranged at intervals alternately with the blades of the rotor 41b in the axial direction of the rotor 41b. The housing protrusions 41c are arranged at a predetermined angular interval along the circumferential direction of the inner wall surface of the mixing chamber formed in a substantially cylindrical shape.

[0044] In the present embodiment, the angular intervals in the axial direction and the circumferential direction of the housing protrusions 41c are both configured to be equally spaced. However, as long as the intervals of the housing protrusions 41c do not affect the properties of the foam, they do not have to be arranged at equal intervals in either the axial direction or the circumferential direction. Further, the mixer 41 is connected to a chiller (not shown), and thereby the temperature in the mixer 41 can be adjusted.

[0045] The rotor 41b is configured to include a substantially cylindrical shape similar to the shape of the mixing chamber. The rotor 41b is configured to be rotatable by a motor (not shown). The rotor 41b includes blades provided on the side surface of the cylindrical shape as shown in FIG. 1. The blades of the rotor 41b are arranged at a predetermined interval in the axial direction of the rotor 41b, similar to the housing protrusions 41c.

[0046] Further, a plurality of blades of the rotor 41b are arranged at a predetermined angular interval in the circumferential direction of the rotor 41b. The intervals in the axial direction and the circumferential direction of the blades of the rotor 41b are configured to be equally spaced in the present embodiment. However, similar to the housing protrusions 41c, as long as they do not affect the properties of the foam, the intervals in the axial direction and the circumferential direction of the blades of the rotor 41b are not limited to being equally spaced.

[0047] (Discharge section) FIGS. 2 and 3 are schematic diagrams for explaining the discharge section 45. The discharge section 45 includes an inlet section 46 into which the foaming material generated by dispersing bubbles in the viscous material by the mixer 41 can flow, and a nozzle (hereinafter referred to as the outlet section 47) capable of discharging the foaming material in a curtain shape in the depth direction of FIGS. 2 and 3. The discharge section 45 has a communication passage for sending the foaming material stirred by the mixer 41 from the inlet section 46 to the outlet section 47, a space forming section 49 that operably houses the valve body 48, and a valve body 48 that switches the flow or blockage of the foaming material by its operation. The space forming section 49 is provided between the inlet section 46 and the outlet section 47 and forms an internal space. The space forming section 49 is configured by, for example, a polyhedron having a flat surface. The inlet section 46 is provided on the side surface of the polyhedron, and the outlet section 47 is provided at the lower part of the polyhedron. As a discharge port, the foaming material generated by dispersing bubbles in the liquid of the resin R by the mixer 41 is discharged. The outlet section 47 is configured to be long and can form a part of the valve seat.

[0048] The valve body 48 is operably housed in the internal space of the space forming section 49. By not communicating with the outlet section 47, the foaming material is not discharged from the outlet section 47. By communicating with the outlet section 47, the foaming material can be discharged. The valve body 48 is configured such that in FIG. 2, like the outlet section 47, its shape extends in the depth direction of the paper surface in FIGS. 2 and the like. The valve body 48 is configured to include a first flow path s1 that connects or disconnects the inlet section 46 and the outlet section 47 depending on the rotational position or angular position. When the flow path inside the valve body 48 communicates with the internal space, the foaming material from the inlet section 46 can flow to the outlet section 47 (see FIG. 2). Conversely, when the flow path of the valve body No. 48 does not communicate with the internal space, the foaming material from the inlet section 46 is not communicated to the outlet section 47 (see FIG. 3). The distance d2 from the outlet section 47 to the proximity part of the valve body 48 in the state where the inlet section 46 is not communicating with the outlet section 47 is configured to be shorter than the distance d1 from the inlet section 46 to the proximity part of the valve body 48. The values of d1 and d2 are not particularly limited as long as they satisfy the above relationship. As an example, d2 can be 15 mm or less, preferably 10 mm or less, more preferably 5 mm or less, and most preferably 0 mm.

[0049] The second pressure sensor 51 is configured to detect (measure) the discharge pressure P2 of the foaming material immediately before it is discharged in the communication passage of the discharge unit 45.

[0050] (Control Unit) The control unit 60 controls each part of the device to perform a dispensing operation in which the foaming material is dispensed as a foam. The control unit 60 can also control the dispensing operation of the foaming material by receiving a dispensing signal from the user (dispensing signal ON) and stop the dispensing operation by ceasing to receive a dispensing signal (dispensing signal OFF).

[0051] (Mechanical Foaming Method) A mechanical foaming method for generating foam using a foaming apparatus 100 will be described below with reference to Figure 4. Figure 4 is a flowchart illustrating a mechanical foaming method according to one embodiment of the present invention.

[0052] In the foaming method, gas G is mixed into the resin R to disperse the bubbles in the liquid resin R, thereby generating a foamable material. As shown in Figure 4, the foaming method generally includes a dispensing operation (S2 to S5). This will be described in detail below.

[0053] When the user turns on the power to the foaming device 100, the control unit 60 operates the mixer 41 in the preparation state (S1). The mixer 41 can be kept running at least continuously during the preparation state. The control unit 60 also controls the supply of resin R from the material supply unit 20 to the piping 10.

[0054] Next, the control unit 60 receives a signal to initiate control of the foaming material dispensing operation based on the user's operation (dispensing signal ON, S2).

[0055] Next, the control unit 60 rotates the first gear pump 31 and the second gear pump 33 so that the second gear pump 33 operates at a higher speed than the first gear pump 31. As a result, the amount of resin R flowing out of the second pipe 12 by the second gear pump 33 is greater than the amount (volume) of resin R flowing into the second pipe 12 by the first gear pump 31. Therefore, a suction pressure is generated in the second pipe 12 in proportion to the volume reduction in the amount of resin R.

[0056] Next, the control unit 60 opens the on-off valve 34 to connect the second pipe 12 and the gas supply unit 32. At this time, gas G is drawn in from the gas supply unit 32 by the suction pressure in the second pipe 12, and pressurized by the gas supply unit 32, or gas G at atmospheric pressure is mixed into the second pipe 12 through the third pipe 13.

[0057] It is preferable to open the on-off valve 34 after a predetermined time, for example, 0.1 to 0.5 seconds, has elapsed since the first gear pump 31 and the second gear pump 33 were driven to rotate. This allows the second pipe 12 and the gas supply unit 32 to be connected while suction pressure is generated in the second pipe 12, thereby suppressing the backflow of resin R into the gas supply unit 32.

[0058] Furthermore, by opening the on-off valve 34 after a predetermined time has elapsed, the on-off valve 34 will open when the pressure in the flow path between the first gear pump 31 and the second gear pump 33 becomes lower than the pressure of the supplied gas, thereby enabling a stable supply of gas.

[0059] The gas G drawn into the second gear pump 33 is sent to the mixer 41 together with the resin R. The resin R containing the pressurized gas G flows into the mixing chamber from the inlet of the mixer 41.

[0060] When the motor rotates the rotor 41b, the blades of the rotor 41b rotate around the axis of the rotor 41b, stirring the resin R containing gas G in the mixing chamber together with the housing protrusions 41c. As a result, the gas G in the resin R is finely dispersed by shear force, and a foaming material is generated. The rotation speed of the rotor 41b can be, for example, 1 to 100 rpm.

[0061] Next, the foaming material generated by the mixer 41 is sent from the outlet of the mixer 41 to the communication passage provided in the discharge section 45. The control unit 60 then controls the valve body 48 of the discharge section 45 to open. As a result, the foaming material is discharged into the atmosphere from the outlet 47 through the communication passage (S3). The gas G of the foaming material discharged into the atmosphere is released from its pressurized state, expands, and hardens or solidifies in a foamed state to produce a foam. Here, the distance from the outlet 47 to the nearest part of the valve body 48 when the inlet 46 is not communicating with the outlet 47 is shorter than the distance from the inlet 46 to the nearest part of the valve body 48, thereby suppressing dripping after the foaming material is discharged. For the sake of explanation, the operations in S3 of Figure 4 have been described in chronological order, but in reality, each operation may occur almost simultaneously.

[0062] The control unit 60 controls the system to stop the dispensing operation when it stops receiving a signal indicating the dispensing operation of the foaming material due to user operation (dispensing signal OFF) (S4). In response, the control unit 60 controls the system to stop the first gear pump 31 and the second gear pump 33. Then, the control unit 60 controls the system to close the on-off valve 34 and close the valve body 48 of the dispensing unit 45 (S5). In the case of continuous operation where the dispensing operation is performed continuously, the system may be configured to return to S2 after S5 and perform the operations S2 to S5 a predetermined number of times.

[0063] As described above, the discharge section 45 of the foaming device 100 has an inlet section 46, an outlet section 47, a space forming section 49, and a valve body 48. The inlet section 46 is configured to allow foaming material, which is a viscous material mixed with gas, to flow in. The outlet section 47 is configured to be elongated in the depth direction of the paper so that foaming material can flow out and be discharged in a curtain-like manner. The space forming section 49 is provided between the inlet section 46 and the outlet section 47 and is configured to form an internal space that houses the valve body 48. The valve body 48 is operably housed in the internal space and is configured to prevent foaming material from being discharged from the outlet section 47 by not communicating with the outlet section 47 (see Figure 3), and to discharge foaming material by communicating with the outlet section 47 (see Figure 2). When the inlet portion 46 is not in communication with the outlet portion 47, the distance d2 from the outlet portion 47 to the nearest part of the valve body 48 is shorter than the distance d1 from the inlet portion 46 to the nearest part of the valve body 48. This configuration prevents or suppresses dripping of the foaming material.

[0064] The valve body 48 is configured to be rotatable within the internal space of the space-forming portion 49 of the discharge portion 45, and includes a rotating portion that has a first flow path s1 which connects or disconnects the inlet portion 46 and the outlet portion 47 depending on the angular position. This configuration allows the valve to perform its opening and closing function.

[0065] (Modified Discharge Section) Figures 5 and 6 are schematic diagrams showing the discharge section 45a according to Modified Example 1. In Figures 2 and 3, a flow path is provided inside the valve body 48, and it was explained that the flow path communicates with or does not communicate with the internal space of the space forming section 49 depending on the rotation position. In addition to this, the valve body of the discharge section can be configured as follows. Note that the inlet section 46 and outlet section 47 are the same as in the embodiment, and the space forming section 49a is formed to match the shape of the valve body 48a, so a detailed explanation is omitted (the same applies to the space forming section 49b in Figure 7 and the space forming section 49c in Figure 8).

[0066] The valve body 48a of the discharge section 45a is configured to move in a direction intersecting the direction in which the foaming material flows within the internal space of the space forming section 49a. The valve body 48a is formed so as to extend in the depth direction of the paper, as shown in Figure 5. The valve body 48a is configured to have a first movable part that includes a second flow path s2 through which the foaming material can flow. With this configuration, depending on the position of the valve body 48a, the flow path may communicate with the internal space as shown in Figure 5, or it may not communicate as shown in Figure 6. Therefore, the discharge of the foaming material can be controlled by the operation of the valve body 48a. In this case as well, when the inlet section 46 is not communicating with the outlet section 47, the distance d2 from the outlet section 47 to the nearest part of the valve body 48a is shorter than the distance from the inlet section 46 to the nearest part of the valve body 48a. With this configuration, dripping can be prevented or suppressed.

[0067] Figure 7 is a schematic diagram showing the discharge section 45b according to Modification 2. In the discharge section 45, the valve body 48 is described as either allowing or not allowing the material to communicate from the inlet section 46 to the outlet section 47 depending on its angular position, but the valve body can be configured as follows. That is, the valve body 48b of the discharge section 45b can be configured so that a plurality of valve parts that can move in the flow direction of the foamed material move back and forth as a single unit. In the case of Figure 7, the foamed material can be discharged from the outlet section 47b in a curtain-like manner in the lateral direction of Figure 7. This prevents the discharge of foamed material from the inlet section 46 when the valve body 48b is in contact with the outlet section 47b, and allows the discharge of foamed material from the inlet section 46 when the valve body 48b is not in contact with the outlet section 47b. In addition, the outlet section 47b can be provided with a confluence section that facilitates mixing of the foamed material flowing through a plurality of holes h provided in the longitudinal direction between the contact area with the valve body 48b and the exposed area to the outside. Even in this case, when the inlet portion 46 is not in communication with the outlet portion 47b, the distance d2 from the outlet portion 47b to the nearest part of the valve body 48b is shorter than the distance d1 from the inlet portion 46 to the nearest part of the valve body 48b. By configuring it in this way, dripping can be prevented or suppressed. In Figure 7, the valve body 48b is shown as having multiple needle-like components that operate as a single unit, but the operation of each of the multiple needles may be controlled separately and independently by a CPU, controller, etc.

[0068] Figure 8 is a schematic diagram showing the discharge section 45c according to Modification 3. The valve body 48c constituting the discharge section 45c may have a tip portion formed to be elongated in a direction intersecting the direction of movement of the discharge section 45c. The tip portion of the valve body 48c contacts the outlet section 47c to prevent the foaming material from the inlet section 46 from being discharged from the outlet section 47c, and the foaming material from the inlet section 46 can be discharged from the outlet section 47c if the tip portion of the valve body 48c and the outlet section 47c do not come into contact. In the case of Figure 8, the foaming material can be discharged from the outlet section 47c in a curtain-like manner in the lateral direction of Figure 8. Even in this case, the distance d2 from the outlet section 47c to the adjacent part of the valve body 48c when the inlet section 46 is not in communication with the outlet section 47c is shorter than the distance d1 from the inlet section 46 to the adjacent part of the valve body 48c. By configuring it in this way, dripping can be prevented or suppressed. The outlet section 47c may constitute part of the valve seat.

[0069] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Although it has been explained above that the inlet portion 46 is provided on the side surface of the space-forming portion 49, the inlet portion 46 may be configured to be provided on the upper part of the space-forming portion 49. Furthermore, although it has been explained that the pump portion includes gear pumps such as a first gear pump and a second gear pump, it may also be configured to include a mono pump, a plunger pump, and other pumps. In addition, the cross-sectional area of ​​each flow path in the valve body 48 in Figure 2 and the valve body 48a in Figure 5, the cross-sectional area of ​​the portion indicated by distance d2 in Figure 7 in the space-forming portion 49b, and the cross-sectional area of ​​the outlet portion 47c of the space-forming portion 49c in Figure 8 may be larger or smaller than the cross-sectional area of ​​the inlet portion 46.

[0070] This application is based on Japanese Patent Application No. 2024-158410, filed on 12 September 2024, the disclosures of which are cited in their entirety by reference.

[0071] 31 First gear pump (first pump section), 33 Second gear pump (second pump section), 45, 45a, 45b, 45c Discharge section, 46 Inlet section, 47, 47b, 47c Outlet section, 48, 48a, 48b, 48c Valve body, 49, 49a, 49b, 49c Space forming section, d1 Distance (distance from the inlet to the nearest part of the valve body when the inlet is not in communication with the outlet section), d2 Distance (distance from the outlet to the nearest part of the valve body when the inlet is not in communication with the outlet section), G Gas, R Resin.

Claims

1. The structure of the discharge section of a foaming device, comprising: an inlet into which a foaming material, which is a viscous material mixed with gas, can flow in; a long outlet into which the foaming material can flow out and which can discharge the foaming material in a curtain-like manner; a space forming section that forms an internal space provided between the inlet and the outlet; and a valve body that is operably housed in the internal space and which, by not communicating with the outlet, prevents the foaming material from being discharged from the outlet, and by communicating with the outlet, enables the discharge of the foaming material, wherein the distance from the outlet to the nearest part of the valve body when the inlet is not communicating with the outlet is shorter than the distance from the inlet to the nearest part of the valve body.

2. The structure of the discharge section of the foaming apparatus according to claim 1, wherein the valve body is rotatably configured and has a rotating section having a first flow path that connects or disconnects the inlet and outlet sections depending on the angular position.

3. The structure of the discharge section of a foaming apparatus according to claim 1, wherein the valve body is translationally movable in a direction intersecting the flow direction of the foaming material and includes a first movable section that connects or disconnects the inlet and outlet sections depending on its position relative to the internal space.

4. The structure of the discharge section of the foaming apparatus according to claim 1, wherein the outlet section is provided with a plurality of holes in the longitudinal direction from which the foaming material can be discharged, and the valve body has a plurality of parts that prevent communication between the inlet section and the outlet section by contacting the surrounding area of ​​the holes, and that enable communication between the inlet section and the outlet section by not contacting the tip of the valve body.

5. The structure of the discharge section of a foaming apparatus according to claim 1, wherein the valve body has a tip portion formed to be elongated in the longitudinal direction of the outlet portion, and by contacting the surrounding area of ​​the outlet portion, the inlet portion and the outlet portion are prevented from communicating, and by being separated from the surrounding area of ​​the outlet portion, the inlet portion and the outlet portion are prevented from communicating.

6. A foaming apparatus comprising: a flow path through which the viscous material can flow; a material supply unit for supplying the viscous material to the flow path; a gas supply unit for supplying gas to the flow path; a first pump unit located in the middle of the flow path; a second pump unit located downstream of the first pump unit in the flow path for generating the suction pressure necessary to produce the foaming material; and the discharge unit according to any one of claims 1 to 5.

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