Resin supply device

Abstract

To provide a resin supplying device that can easily change the combination of liquid materials. [Solution] Resin supply device 10 is capable of supplying multiple types of liquid materials to supply ports 14A, 14B of mixing head 12. Resin supply device 10 includes multiple supply units 16 each capable of supplying a different liquid material, a supply path 18 connecting supply port 16 with supply units 14A, 14B, and a switching unit 22 provided in supply path 18 for switching between a supply mode in which the liquid material is passed through supply ports 14A, 14B and a circulation mode in which the liquid material is returned to supply unit 16 via a circulation path 20. Switching unit 22 has a supply valve 38 that opens and closes supply path 18 and a circulation valve 40 that opens and closes circulation path 20.

Description

[Technical Field]

[0001] The present invention relates to a resin supplying device. [Background technology]

[0002] As described in Patent Document 1, there is a resin supplying device that mixes multiple liquid materials in a mixing head and discharges the mixed liquid from the mixing head. The mixing head usually has two to six material ports to which supply paths of the liquid materials are connected, and if it has six material ports, it is possible to mix and discharge six types of liquid materials. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-120240 Summary of the Invention [Problem to be solved by the invention]

[0004] Due to the increasing functionality of resins, there are cases where it is necessary to use more liquid materials than the number of material ports available on a mixing head. In this case, it becomes necessary to replace the mixing head on the existing production line with one that has the required number of material ports, or to install a new production line, which places a heavy burden on the equipment.

[0005] The present invention has been proposed in view of the above-mentioned problems associated with the conventional technology in order to solve these problems in an appropriate manner, and aims to provide a resin supplying device that can easily change the combination of liquid materials. [Means for solving the problem]

[0006] A first aspect of the resin supplying device according to the present invention is A resin supply device capable of supplying a plurality of liquid materials to a supply port of a mixing head, a plurality of supply units each capable of supplying a different liquid material; a supply path connecting the supply port and the supply unit; a switching unit that is provided in the supply path and that switches between a supply mode in which the liquid material is passed through the supply port and a circulation mode in which the liquid material is returned to the supply unit via a circulation path, The switching unit is a supply valve that opens and closes the supply path that leads from the supply unit to the supply port; The present invention is characterized in that it has a circulation valve that is provided separately from the supply valve and that opens and closes the circulation path.

[0007] A second aspect of the resin supplying device according to the present invention is the same as the first aspect, a return path for returning the liquid material from the mixing head to the supply section; the return path is connected to two or more of the supply parts, The switching unit may have a selection valve that selects the supply unit to which the liquid material is returned.

[0008] A third aspect of the resin supplying device according to the present invention is the same as the first aspect, The supply path may have a mixing section that mixes the liquid materials supplied from the plurality of supply sections.

[0009] A fourth aspect of the resin supplying device according to the present invention is the resin supplying device according to the third aspect, a return path for returning the liquid material from the mixing head to the supply section; The return path is connected to one of the supply parts, the switching unit has a solenoid valve that operates the supply valve and the circulation valve, The electromagnetic valve may be disposed in contact with a block body including the supply valve and the circulation valve.

[0010] A fifth aspect of the resin supplying device according to the present invention is any one of the first aspect, the second aspect, the third aspect, and the fourth aspect, The switching unit may include a pressure increasing unit that increases the pressure of the liquid material passing through the circulation path, the pressure increasing unit being located closer to the supply unit than the circulation valve. [Effects of the Invention]

[0011] According to the resin supplying device of the present invention, the combination of liquid materials can be easily changed. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is an explanatory view showing a resin supplying device according to the first embodiment. [Figure 2] 3 is an explanatory view showing the main parts of the resin supplying device according to the first embodiment when the switching unit is in a supply mode and the mixing head is in a discharge mode. FIG. [Figure 3] 3 is an explanatory view showing the main parts of the resin supplying device according to the first embodiment when the switching unit is in the supply mode and the mixing head is in the return mode. FIG. [Figure 4] FIG. 3 is an explanatory view showing the main parts of the resin supplying device according to the first embodiment when a switching unit is in a circulation mode. [Figure 5] FIG. 10 is an explanatory view showing a resin supplying device according to a second embodiment. [Figure 6] FIG. 10 is a schematic cross-sectional view showing a mixing section of a second embodiment. [Figure 7] 10 is an explanatory diagram showing the main parts of the resin supplying device according to the second embodiment when the switching unit for the first liquid system and the switching unit for the secondary material system are in the supply mode and the mixing head is in the discharge mode. FIG. [Figure 8] FIG. 10 is an explanatory view showing the main parts of the resin supplying device according to the second embodiment when the switching unit for the first liquid system is in the supply mode and the mixing head is in the return mode. DETAILED DESCRIPTION OF THE INVENTION

[0013] Next, a resin supplying device according to the present invention will be described below by way of a preferred embodiment with reference to the accompanying drawings. Note that the embodiments and drawings described below are intended to exemplify a portion of the embodiment of the present invention, and are not intended to limit the scope of the present invention to these configurations, and can be modified as appropriate within the scope of the gist of the present invention.

[0014] (First embodiment) As shown in FIG. 1, a resin supplying apparatus 10 according to a first embodiment is an apparatus capable of supplying multiple liquid materials to a supply port 14 of a mixing head 12. The mixing head 12 mixes the liquid materials supplied from the resin supplying apparatus 10 and supplies the resulting resin to a cavity of a molding die. The mixing head 12 of the first embodiment has two supply ports 14A and 14B. A first liquid as a liquid material is supplied to one supply port 14A, and a second liquid as a liquid material is supplied to the other supply port 14B. Here, the resin supplying apparatus 10 is capable of supplying one type of first liquid selected from multiple types of first liquids to one supply port 14A, and is capable of supplying one type of second liquid selected from multiple types of second liquids to the other supply port 14B.

[0015] The first and second liquids are reactive resin materials that form a curable resin when mixed together. Examples of combinations of the first and second liquids include known combinations of resin components, such as a combination of polyol and isocyanate to produce polyurethane, a combination of bisphenol A and epichlorohydrin to produce epoxy resin, and a combination of epsilon caprolactam with a catalyst and epsilon caprolactam with an activator to produce polyamide (nylon 6).

[0016] In the first embodiment, the configuration for supplying and circulating the first liquid to one supply port 14A is the same as the configuration for supplying and circulating the second liquid to the other supply port 14B. Therefore, the configuration for supplying and circulating the first liquid to one supply port 14A will be described, and the configuration for supplying and circulating the second liquid to the other supply port 14B will be assigned the same reference numerals as the other and will not be described again.

[0017] As shown in FIG. 1 , the resin supplying apparatus 10 includes multiple supply units 16 each capable of supplying a different first liquid (liquid material), a supply path 18 connecting a supply port 14A to the supply units 16, and a switching unit 22 provided in the supply path 18 for switching between a supply mode in which the first liquid passes through the supply port 14A and a circulation mode in which the first liquid is returned to the supply units 16 via a circulation path 20. The resin supplying apparatus 10 also includes a return path 24 for returning the first liquid from the mixing head 12 to the supply units 16. The resin supplying apparatus 10 of the first embodiment has two or more supply units 16, and the return path 24 is connected to all of them. The resin supplying apparatus 10 of the first embodiment includes multiple (three) supply and circulation systems for supplying the first liquid, all of which have the same configuration. Therefore, only one supply and circulation system for the first liquid will be described, and the remaining supply and circulation systems for the first liquid will be designated by the same reference numerals and will not be described again. In the following description, the supply unit 16 side may be referred to as the upstream side, and the supply port 14A side may be referred to as the downstream side.

[0018] As shown in Figure 1, the mixing head 12 includes a mixing chamber 26 that mixes the liquid materials supplied to the supply ports 14A and 14B, a switching piston 28, an actuator 30 that operates the switching piston 28, and a return port 32 connected to the return line 24. By retracting the switching piston 28 from the mixing chamber 26, the mixing head 12 enters a discharge mode in which the liquid materials supplied via the supply ports 14 are mixed in the mixing chamber 26 to produce a resin, and this resin is then discharged from the mixing head 12 (see Figure 2). Furthermore, by closing the mixing chamber 26 with the switching piston 28, the mixing head 12 enters a return mode in which the liquid materials supplied from the supply ports 14 flow into the return port 32 via a groove 28a formed in the switching piston 28 (see Figure 3).

[0019] The supply unit 16 includes a supply tank 34 that stores the first liquid, and a supply pump 36 that sends the first liquid from the supply tank 34 to the supply port 14A. As the supply pump 36, a known pump that can send out the liquid at a predetermined pressure is used.

[0020] As shown in FIG. 1 , the supply path 18 is provided between the supply pump 36 of the supply unit 16 and the supply port 14A, and is a conduit through which the first liquid flows when the supply pump 36 is operated and is pumped from the supply tank 34. The supply path 18 merges with the supply path 18 of another system downstream of the switching unit 22. The circulation path 20 branches off midway from the supply path 18 and is connected to the supply tank 34. The circulation path 20 branches off upstream of a supply valve 38 (described later) of the switching unit 22, and is a conduit that returns the first liquid to the supply tank 34 when the switching unit 22 is in the circulation mode. One end of the return path 24 is connected to the return port 32 of the mixing head 12, and the other end is connected to the circulation path 20. In the first embodiment, the return path 24 is connected to the supply unit 16 side of the circulation path 20 relative to a circulation valve 40 (described later) and a pressure booster 50 (described later) of the switching unit 22. The return line 24 is a conduit that returns the first liquid from the mixer head 12 to the supply tank 34 of the supply unit 16 when the mixer head 12 is in the return mode.

[0021] 1, the switching unit 22 has a supply valve 38 that opens and closes the supply path 18 that leads from the supply unit 16 to the supply port 14A, and a circulation valve 40 that is provided separately from the supply valve 38 and opens and closes the circulation path 20. The supply valve 38 is provided in an individual path of the supply path 18 before it merges with the supply path 18 of another system. The switching unit 22 has a block body 46 that includes multiple control valves such as the supply valve 38 and the circulation valve 40, and also has a solenoid valve 44 that operates these control valves. The solenoid valve 44 is arranged in contact with the block body 46.

[0022] As shown in FIG. 1 , the switching unit 22 has a selection valve 42 that opens and closes the return line 24. The selection valve 42 is provided on an individual path that branches into multiple (three) systems on the return line 24. The selection valve 42 is included in a block body 46. The selection valve 42 is operated by a solenoid valve 44 that also operates the supply valve 38 and the circulation valve 40. That is, in the switching unit 22, the supply valve 38, the circulation valve 40, and the selection valve 42 are opened and closed by the single solenoid valve 44. Note that the supply valve 38, the circulation valve 40, and the selection valve 42 are made of known valves that can open and close pipelines.

[0023] As shown in FIG. 1 , the switching unit 22 has a pressure-increasing unit 50 that increases the pressure of the first liquid passing through the circulation path 20 toward the supply unit 16 side of the circulation valve 40. The pressure-increasing unit 50 is a check valve that prevents backflow of the first liquid through the circulation path 20. The pressure-increasing unit 50 allows the first liquid to flow toward the supply unit 16 side of the circulation path 20, while restricting the flow of the first liquid from the supply unit 16 toward the supply port 14A side of the circulation path 20. When allowing the first liquid to flow toward the supply unit 16 side of the circulation path 20, the pressure-increasing unit 50 increases the pressure of the first liquid passing through the circulation path 20 by limiting the allowable amount. The pressure-increasing unit 50 is included in a block body 46. The switching unit 22 is a single unit that includes the block body 46, which includes the supply valve 38, the circulation valve 40, the selection valve 42, and the pressure-increasing unit 50, and the solenoid valve 44, which is arranged in contact with the block body 46.

[0024] 2 and 3, a case will be described in which the switching unit 22 is switched to the supply mode and the first liquid is supplied to the supply port 14A. In the supply mode, the solenoid valve 44 is operated to open the supply valve 38, thereby opening the supply path 18, and close the circulation valve 40, thereby closing the circulation path 20. The solenoid valve 44 is also operated to open the selection valve 42, thereby opening the return path 24, which returns to the supply unit 16. When the supply pump 36 is operated, the first liquid sent from the supply tank 34 is supplied to the supply port 14A through the supply path 18. At this time, because the circulation valve 40 is closed, the first liquid does not return to the supply tank 34 through the circulation path 20. As shown in FIG. 2, when the mixing head 12 is in the discharge mode, the first liquid introduced from the supply port 14A is mixed with the second liquid in the mixing chamber 26, and a resin is discharged from the mixing head 12.

[0025] As shown in FIG. 3, when the mixing head 12 is in the return mode, the first liquid introduced from the supply port 14A passes through the groove 28a of the switching piston 28 and flows into the return port 32. At this time, the selection valve 42 of the individual path leading to the supply unit 16 supplying the first liquid, which is part of the return line 24 connected to the return port 32, is open, so the first liquid returns to the supply tank 34 of the supply unit 16. In this way, the first liquid circulates between the supply unit 16 from which the first liquid is sent and the mixing head 12. Note that the selection valves 42 of the individual paths leading to the supply units 16 other than the supply unit 16 supplying the first liquid are closed, so the first liquid does not flow into the supply units 16 of other systems. In this way, the selection valve 42 serves as a valve that selects the supply unit 16 to which the first liquid returns.

[0026] Referring to FIG. 4, a case where the switching unit 22 is in the circulation mode will be described. In the circulation mode, the solenoid valve 44 is operated to close the supply valve 38, thereby closing the supply path 18, and to open the circulation valve 40, thereby opening the circulation path 20. The solenoid valve 44 is also operated to close the selection valve 42, thereby closing the return path 24, which returns to the supply unit 16. When the supply pump 36 is operated, the first liquid sent from the supply tank 34 flows through the circulation path 20, is pressurized by the pressure-increasing unit 50 provided in the circulation path 20, and returns to the supply tank 34. In this way, by circulating the first liquid through the circulation path 20 in the circulation mode, the pressure of the first liquid can be increased to a predetermined pressure by the pressure-increasing unit 50. Switching from the circulation mode to the supply mode with the pressure of the first liquid already increased can shorten the time required to supply the first liquid to the mixing head 12, thereby improving the resin injection efficiency.

[0027] The resin supplying apparatus 10 includes multiple supply units 16 capable of supplying different first liquids and a switching unit 22 provided on each supply path 18 connecting the supply units 16 and the supply port 14A. By changing the supply mode of the switching unit 22, the resin supplying apparatus 10 can select different types of liquid materials from the multiple supply units 16 and supply them to the supply ports 14A and 14B. Since the resin supplying apparatus 10 can supply multiple types of liquid materials to a single supply port 14A (14B), the combination of liquid materials can be easily changed. Furthermore, when using multiple types of liquid materials, the resin supplying apparatus 10 does not require replacing the mixing head with one equipped with a number of supply ports corresponding to the multiple types of liquid materials or introducing a new production line, thereby significantly reducing the equipment burden. By setting the switching unit 22 to circulation mode, the resin supplying apparatus 10 can hold liquid materials not supplied to the mixing head 12 in a standby state without losing their fluidity.

[0028] In the resin supply device 10, the return path 24 that returns the liquid material from the mixing head 12 to the supply section 16 is connected to two or more supply sections 16, and the switching section 22 has a selection valve 42 that selects the supply section 16 to which the liquid material is returned. As a result, when circulating a certain type of liquid material between the supply section 16 and the mixing head 12, the liquid material can be returned to the supply section 16 from which it was supplied by selecting the selection valve 42, and mixing of different types of liquid materials can be prevented.

[0029] The switching unit 22 has a pressure boosting unit 50 that boosts the pressure of the liquid material passing through the circulation path 20 on the supply unit 16 side of the circulation valve 40, so that the pressure can be increased before the liquid material is supplied to the mixing head 12, and the time required to supply the liquid material to the mixing head 12 can be shortened.

[0030] In the switching unit 22, the solenoid valve 44 is disposed in contact with a block body 46 including the supply valve 38, the circulation valve 40, and the selection valve 42, so that the solenoid valve 44, the supply valve 38, the selection valve 42, and the circulation valve 40 are close to each other, thereby reducing the time lag between the opening and closing operations of the supply valve 38, the circulation valve 40, and the selection valve 42. In particular, when switching from the circulation mode to the supply mode while the liquid material is pressurized, the quick opening and closing operations of the supply valve 38 and the circulation valve 40 can shorten the time until the liquid material is supplied to the mixing head 12.

[0031] (Second embodiment) While the resin supplying device 10 of the first embodiment exemplifies a case in which multiple types of main materials are supplied as the liquid material, the resin supplying device 60 of the second embodiment selectively supplies multiple types of secondary materials to a single main material as the liquid material, thereby supplying multiple types of liquid materials. Examples of secondary materials include additives that impart appearance properties such as color and mechanical properties such as hardness to the resin generated from the first liquid and the second liquid.

[0032] 5, the resin supply device 60 of the second embodiment is provided with one system for supplying and circulating one type of main material and five systems for supplying and circulating multiple (five types) of secondary materials in one supply port 14A of the mixing head 12. In the second embodiment, the configuration for supplying and circulating the first liquid and the second liquid is the same as in the first embodiment, so the same components are denoted by the same reference numerals and description thereof will be omitted.

[0033] 5, the supply and circulation system for the secondary material includes a supply unit 62 capable of supplying the secondary material, a supply path 64 connecting supply port 14A and supply unit 62, and a switching unit 68 provided in supply path 64 for switching between a supply mode in which the secondary material passes through supply port 14A and a circulation mode in which the secondary material is returned to supply unit 62 via circulation path 66. Furthermore, resin supply device 60 has a mixing unit 70 in supply path 64 that mixes the first liquid supplied from supply unit 16 for supplying the first liquid, which is the main material, with the secondary materials supplied from multiple supply units 62 for supplying the secondary materials.

[0034] 5, the secondary material supply unit 62 includes a supply tank 72 that stores the secondary material, and a supply pump 74 that sends the secondary material from the supply tank 72 to the supply port 14A. As the supply pump 74, a known pump that can send a liquid at a predetermined pressure is used.

[0035] 5, the supply path 64 for the secondary material is provided between the supply pump 74 and the supply port 14A of the supply unit 62, and is a conduit through which the secondary material sent from the supply tank 72 passes when the supply pump 74 is operating. The circulation path 66 for the secondary material branches off midway through the supply path 64 and is connected to the supply tank 72. The circulation path 66 branches off upstream of a supply valve 76 (described later) of the switching unit 68, and is a conduit that returns the secondary material to the supply tank 72 when the switching unit 68 is in the circulation mode. In the second embodiment, the return path 24 is connected to one of the multiple supply units 16, 62, and specifically, the return path 24 is connected only to the supply unit 16 for the first liquid, and no path that returns the liquid material from the mixing head 12 to the supply unit 62 for the secondary material is connected.

[0036] 5, the switching unit 68 has a supply valve 76 that opens and closes the supply path 64 that leads from the supply unit 62 to the supply port 14A, and a circulation valve 78 that is provided separately from the supply valve 76 and that opens and closes the circulation path 66. The supply valve 76 is provided on the supply path 64 upstream of the mixing unit 70. The switching unit 68 has a block body 80 that includes multiple control valves such as the supply valve 76 and the circulation valve 78, and also has a solenoid valve 82 that operates these control valves. The solenoid valve 82 is disposed in contact with the block body 80. Note that the supply valve 76 and the circulation valve 78 are publicly known valves that can open and close pipelines.

[0037] As shown in FIG. 5 , the switching unit 68 has a pressure-increasing unit 86 downstream (supply unit 62) of the circulation valve 78 that increases the pressure of the secondary material passing through the circulation path 66. The pressure-increasing unit 86 is a check valve that prevents backflow of the secondary material through the circulation path 66. The pressure-increasing unit 86 allows the secondary material to flow toward the supply unit 62 side of the circulation path 66, while restricting the flow of the secondary material from the supply unit 62 toward the supply port 14A side of the circulation path 66. When allowing the secondary material to flow toward the supply unit 62 side of the circulation path 66, the pressure-increasing unit 86 increases the pressure of the secondary material passing through the circulation path 66 by limiting the allowable amount. The pressure-increasing unit 86 is included in a block body 80. The switching unit 68 is a single unit that includes a block body 80 that includes the supply valve 76, the circulation valve 78, and the pressure-increasing unit 86, and a solenoid valve 82 that is arranged in contact with the block body 80.

[0038] 5, in the resin supply device 60, the supply path 18 for the first liquid and the supply path 64 for the secondary material converge at the mixing section 70 and are connected to the supply port 14A from the mixing section 70 via a common path. The mixing section 70 is connected to each of the supply paths 64 for the secondary materials and has mixing section check valves 88 that prevent backflow of each secondary material. The mixing section check valves 88 allow the secondary material to flow toward the supply port 14A side while restricting the secondary material from flowing toward the supply section 62 side, thereby preventing the first liquid and the secondary material from unintentionally mixing into the supply tank 72.

[0039] As shown in FIG. 6, the mixing section 70 has a first inlet 90A to which the supply path 18 for the first liquid is connected, multiple second inlet paths 90B to which the supply paths 64 for the secondary material are connected, and one outlet 92. In the mixing section 70, the first inlet 90A to which the supply path 18 for the first liquid is connected is disposed, and multiple second inlet paths 90B to which the supply paths 64 for the secondary material are connected are disposed adjacent to the first inlet 90A. The mixing section 70 has a first path 94A connected to the first inlet 90A and multiple second paths 94B connected to the second inlet 90B. Each second path 94B opens into the first path 94A, and a mixing section check valve 88 is disposed near the outlet of the second path 94B that opens into the first path 94A.

[0040] 7 and 8, a case will be described in which the first liquid switching unit 22 and the secondary material switching unit 68 are set to supply mode to supply the first liquid and the secondary material to the supply port 14A. The first liquid system is the same as in the first embodiment. In the secondary material system, in supply mode, the solenoid valve 82 is operated to open the supply valve 76, opening the supply path 64, and the circulation valve 78 is closed, closing the circulation path 66. When the supply pump 74 is operated, the secondary material sent from the supply tank 72 flows into the mixing unit 70 through the supply path 64 and mixes with the first liquid flowing into the mixing unit 70 from the first liquid system in supply mode. A mixture of the first liquid and the secondary material is supplied to the supply port 14A. At this time, because the circulation valve 78 is closed, the secondary material does not return to the supply tank 72 via the circulation path 66. When the mixing head 12 is in the discharge mode, the mixed material introduced from the supply port 14A is mixed with the second liquid in the mixing chamber 26, and the resin is discharged from the mixing head 12.

[0041] As shown in Figure 8, when the mixing head 12 is in the return mode, the mixed material introduced from the supply port 14A passes through the groove 28a of the switching piston 28 and flows into the return port 32. At this time, the selection valve 42 of the return line 24 leading to the supply unit 16, which is supplying the first liquid, is open, so the mixed material returns to the supply tank 34 of the supply unit 16. In addition, the supply of the secondary material is stopped by switching the switching unit 68 of the secondary material system to the circulation mode. In this way, the first liquid circulates between the supply unit 16 and the mixing head 12. In addition, because the secondary material system does not have a return line 24, the mixed material does not flow into the secondary material supply unit 62.

[0042] Referring to FIG. 8 , a case where the secondary material switching unit 68 is in circulation mode will be described. The system for the first liquid is the same as in the first embodiment. In the system for the secondary material, in circulation mode, the solenoid valve 82 is operated to close the supply valve 76, thereby closing the supply path 64, and the circulation valve 78 is opened, thereby opening the circulation path 66. When the supply pump 74 is operated, the secondary material sent from the supply tank 72 flows through the circulation path 66, is pressurized by the pressure-increasing unit 86 provided in the circulation path 66, and returns to the supply tank 72. In this way, by circulating the secondary material through the circulation path 66 in circulation mode, the pressure of the secondary material can be increased to a predetermined pressure by the pressure-increasing unit 86. Switching from circulation mode to supply mode with the pressure of the secondary material already increased can shorten the time it takes to supply the secondary material to the mixing head 12, thereby improving the efficiency of resin injection.

[0043] The resin supplying device 60 of the second embodiment achieves the same effects as the first embodiment. In addition, the resin supplying device 60 of the second embodiment has a mixing section 70 in the supply paths 18, 64 that mixes the liquid materials supplied from the multiple supply sections 16, 62, so that multiple types of liquid materials can be produced by mixing them before being supplied to the mixing head 12. In particular, when a main material and a secondary material are supplied as liquid materials, the main material and the secondary material can be mixed in the mixing section 70, so that the secondary material can be dispersed in the main material, improving the quality of the resin.

[0044] The resin supply device 60 of the second embodiment includes a return path 24 that returns the first liquid of the liquid material from the mixing head 12 to the first liquid supply unit 16. The return path 24 is connected only to the first liquid supply unit 16 and not to the secondary material supply unit 62. This prevents the first liquid from being mixed into the secondary material supply unit 62. Similarly to the first liquid switching unit 22, the secondary material switching unit 68 also includes a solenoid valve 82 abutting against a block body 80 that includes a supply valve 76 and a circulation valve 78. This reduces the time lag between the opening and closing of the supply valve 76 and the circulation valve 78, as the solenoid valve 82 is positioned close to the supply valve 76 and the circulation valve 78. The fast opening and closing of the supply valve 76 and the circulation valve 78 minimizes the amount of secondary material different from the selected secondary material that gets mixed into the first liquid supply unit 16 when switching the type of secondary material. In particular, when switching from circulation mode to supply mode while the secondary material is pressurized, the time lag between the opening and closing operations of the supply valve 76 and the circulation valve 78 is small, thereby shortening the time required to supply the secondary material to the mixing head 12.

[0045] (Example of change) The present invention is not limited to the above-mentioned matters, but may be, for example, as follows: Note that the present invention is not limited to the specific descriptions of the embodiment and the following modified examples. (1) The number of supply ports is not limited to two as in the above-described embodiment, and may be more than 2. The resin supply device may be capable of supplying multiple types of liquid materials to at least one supply port, or may be capable of supplying multiple types of liquid materials to all supply ports. (2) The number of types of liquid materials is not limited to the above-described embodiment. (3) In the first embodiment, the return path is connected to all of the multiple supply parts, but this is not limiting, and it may be connected to two or more supply paths. [Explanation of symbols]

[0046] 10,60 resin supply device, 12 mixing head, 14A,14B supply port, 16,62 supply section, 18,64 supply path, 20,66 circulation path, 22,68 switching section, 24 Return path, 38, 76 Supply valve, 40, 78 Circulation valve, 42 Selector valve, 44, 82 Solenoid valve, 46,80 block body, 50,86 booster section

Claims

1. A resin supply device capable of supplying a plurality of liquid materials to a supply port of a mixing head, a plurality of supply units each capable of supplying a different liquid material; a supply path connecting the supply port and the supply unit; a switching unit that is provided in the supply path and that switches between a supply mode in which the liquid material is passed through the supply port and a circulation mode in which the liquid material is returned to the supply unit via a circulation path, The switching unit is a supply valve that opens and closes the supply path that leads from the supply unit to the supply port; a circulation valve that is provided separately from the supply valve and opens and closes the circulation path;

2. a return path for returning the liquid material from the mixing head to the supply section; the return path is connected to two or more of the supply parts, The resin supplying device according to claim 1 , wherein the switching unit has a selection valve for selecting the supply unit to which the liquid material returns.

3. The resin supplying device according to claim 1 , wherein the supply path includes a mixing section that mixes the liquid materials supplied from the plurality of supply sections.

4. a return path for returning the liquid material from the mixing head to the supply section; The return path is connected to one of the supply parts, the switching unit has a solenoid valve that operates the supply valve and the circulation valve, 4. The resin supply device according to claim 3, wherein the electromagnetic valve is disposed in contact with a block body including the supply valve and the circulation valve.

5. The resin supplying device according to claim 1 , wherein the switching unit includes a pressure increasing unit that increases the pressure of the liquid material passing through the circulation path on the supply unit side of the circulation valve.

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