Heating system

Abstract

To provide a heating system capable of suppressing deterioration of heating efficiency of a mold device.SOLUTION: A heating system for heating a mold device, the heating system including: a first heating device which heats a liquid; a second heating device which is disposed in a path different from a path of the first heating device and heats the liquid; a first on-off valve which opens and closes a connection path; and a second on-off valve which is disposed in a second supply path and opens and closes the second supply path, wherein, in a state where the first on-off valve is closed and the second on-off valve is opened, first heating control for heating the mold device by using the first heating device and the second heating device is executed, and, and a second heating control of stopping the second heating device, closing the second on-off valve, closing the second on-off valve, opening the first on-off valve, causing the liquid supplied from the first heating device to pass through the connection passage, and heating the mold unit by the first heating device, when the first heating control is ended.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a heating system for heating a mold assembly. [Background technology]

[0002] A heating system for heating a mold device has been known in the past (see, for example, Patent Document 1). The heating system of Patent Document 1 has three heating units: a high-temperature unit, a medium-temperature unit, and a low-temperature unit. A liquid corresponding to the temperature of each heating unit is supplied to each heating unit from a pump. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-202670 Summary of the Invention [Problem to be solved by the invention]

[0004] In the heating system of Patent Document 1, four pumps are used to supply liquid to each heating unit. The heating system of Patent Document 1 is provided with a confluence where the liquids discharged from each pump join together. In the heating system of Patent Document 1, depending on the timing of opening and closing the valves, the liquids discharged from each pump may interfere with each other at the confluence. If the liquids interfere with each other, the efficiency of heating the mold device may decrease.

[0005] An object of the present disclosure is to provide a heating system that can suppress deterioration in the heating efficiency of a mold device. [Means for solving the problem]

[0006] The heating system according to the present disclosure is a heating system for heating a mold device, comprising: a first heating device for heating a liquid; a second heating device arranged on a path different from the first heating device for heating a liquid; a first supply path for supplying liquid from the first heating device to the mold device; a second supply path for supplying liquid from the second heating device to the mold device; a connecting passage connecting the first supply path and the second supply path; a first opening / closing valve arranged on the connecting passage for opening and closing the connecting passage; and a second opening / closing valve arranged on the second supply path for opening and closing the second supply path. With the first opening / closing valve closed and the second opening / closing valve open, a first heating control is performed to heat the mold device using the first heating device and the second heating device. When the first heating control is terminated, the second heating device is stopped and then the second opening / closing valve is closed, and after the second opening / closing valve is closed, the first opening / closing valve is opened, and the liquid supplied from the first heating device is passed through the connecting passage to heat the mold device using the first heating device. [Effects of the Invention]

[0007] According to this heating system, when the first heating control is terminated, the second on-off valve is closed to stop the flow of liquid in the second supply path. In this state, by opening the first on-off valve, the liquid supplied from the first heating device flows into the second path via the connecting passage. This allows the paths to be switched without interference between the flow of liquid supplied from the second heating device and the flow of liquid supplied from the first heating path. As a result, deterioration of the heating efficiency of the mold device can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a system diagram of a heating system in a first heating control state according to an embodiment of the present disclosure. [Figure 2] 4 is a flowchart showing a control procedure executed by a control device according to an embodiment of the present disclosure. [Figure 3] FIG. 10 is a diagram illustrating a state in which a second on-off valve is closed in the heating system according to the embodiment of the present disclosure. [Figure 4] FIG. 4 is a diagram showing a second heating control state of the heating system according to the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0010] As shown in FIG. 1, the heating system 1 includes a first mold device 2, a second mold device 4, a first heating device 6, a second heating device 8, a first supply path 10, a second supply path 12, a third supply path 13, a connecting passage 14, a first on-off valve V1, a second on-off valve V2, a third on-off valve V3, a first temperature sensor 16, a second temperature sensor 18, and a control device 20.

[0011] The first mold assembly 2 has a first mold 2a. The first mold 2a includes a first upper mold 2b and a first lower mold 2c. In this embodiment, the first mold assembly 2 is a mold assembly for a resin injection mold that injects and molds liquid resin with the first upper mold 2b and the first lower mold 2c in a mold closed state. In such a mold assembly for a resin injection mold, the liquid resin becomes easier to flow by heating the mold. This allows the resin to flow to every corner of the mold, improving moldability. The first mold assembly 2 may also include a device that can move the first upper mold 2b and the first lower mold 2c in the mold closing and mold opening directions.

[0012] The second mold assembly 4 has a temperature adjustment table 4a and a second mold 4b. The second mold 4b may include a second upper mold 4c and a second lower mold 4d. In this embodiment, the second mold assembly 4 is an apparatus for preheating the second mold 4b before it is placed in the first mold assembly 2. By preheating the second mold 4b in this way, the heating time when the second mold 4b is placed in the first mold assembly 2 can be reduced.

[0013] The first heating device 6 is a device that heats the liquid to be supplied to the first mold device 2. In this embodiment, the first mold device 2 has a heater and a pump, and the heater heats water to generate hot water. The recycled hot water is discharged toward the first supply path 10.

[0014] The second heating device 8 is arranged on a different path from the first heating device 6. In this embodiment, the second heating device 8 is arranged on the second supply path 12 or the third supply path 13. In this embodiment, the second mold device 4 has a heater and a pump, and generates hot water by heating water with the heater. The recycled hot water is discharged toward the second supply path 12 or the third supply path 13.

[0015] The first supply path 10 is a path that supplies liquid from the first heating device 6 to the first mold assembly 2. In this embodiment, the first supply path 10 has a first feed path 10s that sends liquid from the first heating device 6 to the first mold assembly 2, and a first return path 10r that returns the liquid from the first mold assembly 2. The first feed path 10s branches into two paths, one of which supplies liquid to the first upper mold assembly 2b and the other of which supplies liquid to the first lower mold assembly 2c. The first return path 10r is where the path returning from the first upper mold assembly 2b and the path returning from the first lower mold assembly 2c join together and return to the first heating device 6. In this way, the first supply path 10 is a circulation path that circulates the liquid from the first heating device 6 via the first mold assembly 2 to the first heating device 6.

[0016] The second supply path 12 is a path that supplies liquid from the second heating device 8 to the first mold assembly 2. In this embodiment, the second supply path 12 has a second feed path 12s that sends liquid from the second heating device 8 to the first mold assembly 2, and a second return path 12r that returns liquid from the first mold assembly 2. The second feed path 12s branches into two paths, one of which supplies liquid to the first upper mold assembly 2b and the other of which supplies liquid to the first lower mold assembly 2c. The second return path 12r is where the path returning from the first upper mold assembly 2b and the path returning from the first lower mold assembly 2c join together and return to the second heating device 8. In this way, the second supply path 12 is a circulation path that circulates liquid from the second heating device 8 via the first mold assembly 2 to the second heating device 8.

[0017] In this embodiment, the second supply path 12 branches off from and merges with the third supply path 13. Specifically, the second feed path 12s branches off from a third feed path 13s, which will be described later. The second return path 12r merges with a third return path 13r, which will be described later.

[0018] The third supply path 13 is a path that supplies the liquid toward the second mold device 4. In this embodiment, the third supply path 13 has a third feed path 13s that sends the liquid from the second heating device 8 to the second mold device 4, and a third return path 13r that returns the liquid from the second mold device 4. The third supply path 13 is a circulation path that circulates the liquid from the second heating device 8 via the second mold device 4 to the second heating device 8.

[0019] The connecting passage 14 connects the first supply path 10 and the second supply path 12. As shown in an enlarged view in FIG. 1, the connecting passage 14 has a feed connecting passage 14s and a return connecting passage 14r. The feed connecting passage 14s connects the downstream side of the branch of the first feed path 10s with the downstream side of the branch of the second feed path 12s. The return connecting passage 14r connects the upstream side of the junction of the first return path 10r with the upstream side of the junction of the second return path 12r.

[0020] The first on-off valve V1 is disposed in the connecting passage 14 and opens and closes the connecting passage 14. The first on-off valve V1 is an electromagnetic valve that can open and close the connecting passage 14. The first on-off valve V1 is electrically connected to the control device 20. When the first on-off valve V1 is opened, the first supply path 10 and the second supply path 12 are connected, and the liquid discharged from the first heating device 6 flows into the second supply path 12. In this embodiment, the first on-off valve V1 has a first feed on-off valve V1s and a first return on-off valve V1r. The first feed on-off valve V1s is disposed in the feed connecting passage 14s. The first return on-off valve V1r is disposed in the return connecting passage 14r.

[0021] The second on-off valve V2 is disposed on the second supply path 12 and opens and closes the second supply path 12. The second on-off valve V2 is an electromagnetic valve that can open and close the second supply path 12. The second on-off valve V2 is electrically connected to the control device 20. When the second on-off valve V2 is opened, the liquid discharged from the second heating device 8 flows into the second supply path 12 via the third supply path 13. In this embodiment, the second on-off valve V2 has a second feed on-off valve V2s and a second return on-off valve V2r. The second feed on-off valve V2s is disposed on the second feed path 12s. The second return on-off valve V2r is disposed on the second return path 12r.

[0022] As shown enlarged in FIG. 1, a third on-off valve V3 is disposed in each of the two branched first feed paths 10s, the two branched second feed paths 12s, the two first return paths 10r before merging, and the two second return paths 12r before merging (hereinafter referred to as each path). The third on-off valve V3 can stop or allow the flow of liquid in each path by opening or closing each path. The third on-off valve V3 is a manual valve that can open and close each path. In this embodiment, the third on-off valve V3 is always in an open state.

[0023] The first temperature sensor 16 is a sensor that acquires the temperature (first temperature T1) of the liquid in the first supply path 10. In this embodiment, the first temperature sensor 16 acquires the temperature of the liquid flowing through the first return path 10r.

[0024] The second temperature sensor 18 is a sensor that acquires the temperature (second temperature T2) of the liquid in the second supply path 12. In the present embodiment, the second temperature sensor 18 acquires the temperature of the liquid flowing through the second return path 12r.

[0025] The control device 20 is a device that controls the first on-off valve V1 and the second on-off valve V2. The control device 20 is actually configured by a microcomputer that includes an arithmetic unit, memory (ROM, RAM, non-volatile RAM, etc.), an input / output buffer, etc. The control device 20 acquires the first temperature T1 and the second temperature T2 from each sensor and the first temperature sensor 16 and the second temperature sensor 18, and controls the first on-off valve V1 and the second on-off valve V2 based on a program stored in the memory.

[0026] Next, the control procedure executed by the control device 20 will be described with reference to the flowchart of FIG.

[0027] In step S1, the control device 20 executes first heating control. As shown in FIG. 1, in the first heating control, the control device 20 closes the first on-off valve V1 and opens the second on-off valve V2, resulting in a first state. In the first state, the first supply path 10 and the second supply path 12 are separated. In the first state, when the first heating device 6 and the second heating device 8 are operated, the liquid (hot water) heated by the first heating device 6 circulates through the first supply path 10 and heats the first mold device 2. The liquid (hot water) heated by the second heating device 8 circulates through the second supply path 12 and heats the first mold device 2. In this way, by using two heating devices to heat the first mold device 2, the heating time of the first mold device 2 can be shortened. After executing the first heating control, the control device 20 proceeds to step S2.

[0028] In step S2, the control device 20 determines whether the second temperature T2 is equal to or higher than the first predetermined temperature TD1. The first predetermined temperature TD1 is, for example, 110°C. If the second temperature T2, which is the temperature of the liquid in the second return path 12r, is equal to or higher than the first predetermined temperature TD1 (YES in step S2), the temperature of the first mold device 2 has risen sufficiently. Therefore, the control device 20 must stop the supply of liquid from the second heating device 8. Therefore, the control device 20 proceeds to step S3.

[0029] In step S3, the control device 20 stops the second heating device 8. When the second heating device 8 stops, circulation through the second supply path 12 stops. The control device 20 stops the second heating device 8 and ends the first heating control. After the control device 20 stops the second heating device 8, the process proceeds to step S4.

[0030] In step S4, the control device 20 determines whether or not a predetermined time Dt has elapsed since the second heating device 8 was stopped. If the control device 20 determines that the predetermined time Dt has elapsed (YES in step S4), the process proceeds to step S5.

[0031] In step S5, the control device 20 sets the second state in which the second on-off valve V2 is closed. That is, when terminating the first heating control, the control device 20 closes the second on-off valve V2 when a predetermined time Dt has elapsed since the second heating device 8 was stopped. As shown by the solid lines in FIG. 3 , in the second state, the downstream of the second feed on-off valve V2s and the upstream of the second return on-off valve V2r in the second supply path 12 are separated from the upstream of the second feed on-off valve V2s and the downstream of the second return on-off valve V2r. This prevents interference between the liquid supplied from the first heating device 6 and the liquid supplied from the second heating device 8 when the first on-off valve V1 is opened. Furthermore, the second on-off valve V2 closes after a predetermined time Dt (e.g., about 5 seconds) has elapsed since the second heating device 8 was stopped. This allows the second on-off valve V2 to be closed when circulation in the second supply path 12 is completely stopped. As a result, the load on the second on-off valve V2 is reduced, and the second on-off valve V2 can be reliably closed while preventing backflow of liquid in the second supply path 12. After closing the second on-off valve V2, the control device 20 proceeds to step S6.

[0032] In step S6, the control device 20 sets the first on-off valve V1 to a third state in which it is open. That is, when ending the first heating control, the control device 20 stops the second heating device 8 and then closes the second on-off valve V2, and after closing the second on-off valve V2, opens the first on-off valve V1. After opening the first on-off valve V1, the control device 20 proceeds to step S7.

[0033] In step S7, the control device 20 executes the second heating control. As shown by the solid line in FIG. 4, in the third state, the liquid supplied from the first heating device 6 passes through the connecting passage 14 (see the enlarged view in FIG. 4). In the second heating control, the liquid supplied from the first heating device 6 passes through the connecting passage 14, and the first heating device 6 heats the first mold device 2. At this time, the control device 20 may again drive the second heating device 8 and circulate the liquid through the third supply path 13 to heat the second mold device 4. In this embodiment, since the first heating device 6 is always operating, the second heating control is automatically executed when the control device 20 completes the processing of step S6. After executing the second heating control, the control device 20 returns.

[0034] If the control device 20 determines in step S2 that the second temperature T2 is less than the first predetermined temperature TD1 (NO in step S2), the control device 20 proceeds to step S8. In step S8, the control device 20 determines whether the difference between the first temperature T1, which is the temperature of the liquid in the first supply path 10, and the second temperature T2, which is the temperature of the liquid in the second supply path 12, is equal to or greater than the second predetermined temperature TD2. If the difference between the first temperature T1 and the second temperature T2 is large, heat from the liquid in the first supply path 10 is transferred to the liquid in the second supply path 12, reducing the thermal efficiency (heating efficiency) of heating the first mold device 2. As a result, it is better to heat the first mold device 2 only with the first heating device 6. If the control device 20 determines that the difference between the first temperature T1 and the second temperature T2 is equal to or greater than the second predetermined temperature DT2 (YES in step S8), the control device 20 proceeds to step S3 and ends the first heating control. On the other hand, when the control device 20 determines that the difference between the first temperature T1 and the second temperature T2 is less than the second predetermined temperature DT2 (NO in step S8), the control device 20 returns and continues the first heating control.

[0035] As described above, according to the present disclosure, it is possible to provide a heating system 1 that can suppress deterioration in the heating efficiency of a mold device.

[0036] <Other embodiments> Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications are possible within the scope of the gist of the invention. In particular, the multiple modifications described in this specification can be arbitrarily combined as necessary.

[0037] In the above embodiment, the first feed path 10s and the second feed path 12s are branched into two paths, one of which supplies liquid to the first upper mold 2b and the other to the first lower mold 2c, but the present disclosure is not limited to this. The first feed path 10s and the second feed path 12s do not have to branch. Alternatively, the first feed path 10s may supply liquid to the first upper mold 2b, and the second feed path 12s may supply liquid to the first lower mold 2c. The same applies to the first return path 10r and the second return path 12r.

[0038] In the above embodiment, the second supply path 12 is branched off from the third supply path 13, but the present disclosure is not limited to this. The second supply path 12 may be directly connected to the second heating device 8. [Explanation of symbols]

[0039] 1: Heating system 2: First mold device, 4: Second mold device 6: 1st heating device, 8: 2nd heating device 10: First supply path, 12: Second supply path, 14: Connecting passage 20: Control device DT2: Second predetermined temperature, Dt: Predetermined time T1: 1st temperature, T2: 2nd temperature TD1: 1st predetermined temperature, TD2: 2nd predetermined temperature V1: First on-off valve, V2: Second on-off valve

Claims

1. 1. A heating system for heating a mold assembly, comprising: a first heating device for heating the liquid; a second heating device disposed on a path different from that of the first heating device and configured to heat the liquid; a first supply path for supplying liquid from the first heating device to the mold device; a second supply path for supplying liquid from the second heating device to the mold device; a connecting passage connecting the first supply path and the second supply path; a first on-off valve disposed on the connecting passage and configured to open and close the connecting passage; a second on-off valve disposed on the second supply path and configured to open and close the second supply path; Equipped with a first heating control is executed to heat the mold device using the first heating device and the second heating device in a state where the first on-off valve is closed and the second on-off valve is opened; When terminating the first heating control, the second heating device is stopped and then the second on-off valve is closed, and after the second on-off valve is closed, the first on-off valve is opened; a second heating control is performed in which the liquid supplied from the first heating device is passed through the connecting passage to heat the mold device by the first heating device; Heating system.

2. when terminating the first heating control, if a predetermined time has elapsed since the second heating device was stopped, the second on-off valve is closed. The heating system of claim 1 .

3. acquiring a temperature of the liquid in the second supply path, and ending the first heating control when the temperature becomes equal to or higher than a first predetermined temperature; The heating system of claim 2 .

4. a first temperature, which is the temperature of the liquid in the first supply path, and a second temperature, which is the temperature of the liquid in the second supply path, are acquired, and when a difference between the first temperature and the second temperature becomes equal to or greater than a second predetermined temperature, the first heating control is terminated. A heating system according to any one of claims 1 to 3.

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