Injection molding machine for foam molding and method for molding foam molded products

Abstract

To provide an injection molding machine for foam molding without a risk of gas leakage.SOLUTION: An injection molding machine (1) includes: a heating cylinder (17) with a gas inlet (28); a screw (18); a gas supply device (5) that supplies gas to the gas inlet (28); and control means (4). The gas supply device (5) is provided with a valve mechanism (35) in a gas flow path. The control means (4) is configured to control the valve mechanism (35) so that it is closed at least once during a molding cycle and kept open at least during a weighing process.SELECTED DRAWING: Figure 3A

Description

[Technical Field]

[0001] The present invention relates to an injection molding machine for foam molding that injects an inert gas into an injection material to form a foam-molded product, and to a method for molding a foam-molded product. [Background technology]

[0002] An injection molding machine for foam molding that uses a physical foaming agent, i.e., gas, to produce foam-molded products is generally configured as follows, as described in Patent Document 1, for example. The injection unit of the injection molding machine is composed of a heating cylinder and a screw, and the interior of the heating cylinder is divided into multiple sections according to the shape of the screw, with, from upstream to downstream, a first compression / metering section, a starvation section, and a second compression / metering section. The heating cylinder is provided with a gas inlet corresponding to the starvation section. Gas is supplied by a gas supply device equipped with a gas cylinder or the like, and the gas flow path of the gas supply device is connected to the gas inlet.

[0003] The resin is sent from upstream to downstream inside the heating cylinder by a screw, where it is melted and kneaded in the first compression and metering section. Then, in the starvation section, the resin pressure is reduced and gas such as nitrogen or carbon dioxide is injected. The gas-injected resin is kneaded, compressed, and metered in the second compression and metering section, and then injected into a mold to obtain a foam-molded product. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-200937 Summary of the Invention [Problem to be solved by the invention]

[0005] In injection molding machines for foam molding, after the metering process is completed, some of the gas injected into the heating cylinder may flow back through the heating cylinder and leak from the upstream side of the heating cylinder, which is known as a gas leak.

[0006] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0007] The present disclosure provides an injection molding machine having the following configuration. Specifically, the injection molding machine comprises a heating cylinder provided with a gas inlet, a screw, a gas supply device that supplies gas to the gas inlet, and control means. The gas supply device comprises a gas cylinder, a primary gas pipe to which the gas cylinder is connected, a pressure reducing valve connected to the primary gas pipe, a secondary gas pipe connected to the pressure reducing valve and through which the gas in the primary gas pipe is reduced in pressure and supplied, and a valve mechanism provided in the secondary gas pipe. The control means controls the valve mechanism to: It opens a specified lead time before the start of the weighing process. , and is configured to close after a specified delay time has elapsed after the completion of the metering process. [Effects of the Invention]

[0008] According to the present disclosure, the gas flow path to the gas inlet can be opened and closed to prevent gas leakage, which is the backflow of gas within the heating cylinder. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a front view showing an injection molding machine according to an embodiment of the present invention; [Figure 2] FIG. 2 is a front cross-sectional view showing an injection device and a gas supply device according to the present embodiment. [Figure 3A] 4 is a time chart illustrating a method for molding a foam-molded product performed in the injection molding machine according to the present embodiment. [Figure 3B] 10 is a time chart illustrating another molding method for a foam-molded product performed in the injection molding machine according to the present embodiment. [Figure 4] 10 is a graph showing changes in screw position, screw rotation speed, resin pressure, and gas pressure when a molding cycle is performed with gas constantly supplied to the gas inlet in the injection molding machine according to the present embodiment. [Figure 5A] FIG. 10 is a front cross-sectional view showing an injection device and a gas supply device according to a second embodiment of the present invention. [Figure 5B] FIG. 10 is a front cross-sectional view showing an injection device and a gas supply device according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Specific embodiments will be described in detail below with reference to the drawings. However, the present invention is not limited to the following embodiments. For clarity of explanation, the following description and drawings have been simplified as appropriate. In each drawing, the same elements are given the same reference numerals, and duplicate explanations are omitted as necessary. Furthermore, hatching has been omitted in some areas to avoid cluttering the drawings.

[0011] The present embodiment will be described. <Injection molding machine> As shown in Fig. 1, an injection molding machine 1 according to this embodiment is generally composed of a mold clamping unit 2 provided on a bed B, an injection unit 3, a gas supply unit 5 that supplies gas to the injection unit 3, and a controller 4 that controls these units. The mold clamping unit 2 can also be configured as a direct pressure type, but in this embodiment it is configured as a toggle type. That is, the mold clamping unit 2 is composed of a fixed platen 7, a movable platen 8, a mold clamping housing 9, tie bars 10, 10, ... that connect the mold clamping housing 9 and the fixed platen 7, and a toggle mechanism 11. Molds 13 and 14 are provided on the fixed platen 7 and the movable platen 8. Therefore, when the toggle mechanism 11 is driven, the molds 13 and 14 are clamped.

[0012] <Injection device> The injection device 3 according to this embodiment is supplied with gas by a gas supply device 5, which will be described later, and a resin kneaded and mixed with the gas, i.e., a resin containing a physical foaming agent, is metered out. Therefore, when this resin is injected, a foam-molded product is obtained. In other words, this is an injection device 3 for foam molding.

[0013] The injection device 3 includes a heating cylinder 17, a screw 18 placed inside the heating cylinder 17 as shown in Figure 2, and a screw drive device 19 (see Figure 1) that supports the heating cylinder 17 and drives the screw 18. The heating cylinder 17 is provided with a hopper 21 on its upstream side and an injection nozzle 22 at its downstream end.

[0014] As shown in Figure 2, the flight groove depth of the screw 18 changes from upstream to downstream, and the heating cylinder 17 is divided into multiple sections. That is, from the upstream side, it is divided into a supply section 24 where the resin is supplied and melted, a first compression / metering section 25 where the molten resin is compressed, a starvation section 26 where the pressure of the resin decreases, and a second compression / metering section 27. A gas injection port 28 is opened in the heating cylinder 17 corresponding to the starvation section 26, so that gas can be injected into the molten resin. The resin injected with gas in this way is kneaded in the second compression / metering section 27.

[0015] A resin pressure sensor 30 is embedded in the heating cylinder 17 in relation to the gas inlet 28. That is, the resin pressure sensor 30 is embedded near the gas inlet 28 so as to detect the resin pressure in the starvation section 26. The detected resin pressure is sent to the controller 4.

[0016] <Gas supply equipment> The gas supply device 5 according to this embodiment includes a gas cylinder 32 serving as a gas supply source, a pressure reducing valve 34, and an on-off valve 35. A primary gas pipe 36 is connected to the gas cylinder 32, and a relatively high-pressure primary gas is supplied to the primary gas pipe 36. The pressure reducing valve 34 is connected between the primary gas pipe 36 and the secondary gas pipe 37, and reduces the gas pressure from the primary pressure to a secondary pressure suitable for supplying to the resin. The secondary gas pipe 37 is provided with an on-off valve 35, which is connected to the gas inlet 28. The on-off valve 35 opens and closes the gas flow path of the secondary gas pipe 37. When the gas flow path is opened, gas at the secondary pressure is supplied from the gas inlet 28 into the heating cylinder 17. When the gas flow path is closed, the gas supply is stopped.

[0017] In the gas supply device 5, a gas pressure gauge 39 is provided on the secondary gas pipe 37 to detect the secondary pressure of the gas. In other words, it essentially detects the pressure of the gas supplied from the gas inlet 28. The gas pressure gauge 39 and the on-off valve 35 are connected to the controller 4, the secondary pressure is transmitted to the controller 4, and the controller 4 controls the opening and closing of the on-off valve 35. As will be described next, in this embodiment, the on-off valve 35 is controlled to be closed at least once in the molding cycle and to be in an open state in the metering process.

[0018] <Method for forming foam molded products> A method for molding a foam-molded product performed by the injection molding machine 1 according to this embodiment will be described. Figure 3A shows the molding cycle performed by the injection molding machine 1 (see Figure 1) and the operation of the on-off valve 35 of the gas supply device 5 according to this embodiment, i.e., the valve mechanism, in parallel. The on-off valve 35 is opened and closed at a predetermined timing in synchronization with the molding cycle, but the operation of the on-off valve 35 will not be described here, and only the molding cycle performed by the injection molding machine 1 will be described first.

[0019] In the molding cycle performed by the injection molding machine 1, the mold clamping process is carried out first. That is, the mold clamping device 2 (see Figure 1) is driven to clamp the molds 13, 14. Next, the screw 18 is driven axially to carry out the injection process, injecting resin into the molds 13, 14. Note that it is assumed that a quantity of resin containing melted gas has been measured in advance into the heating cylinder 17 (see Figure 2). Therefore, the resin foams within the molds 13, 14, resulting in a foam-molten product. As shown in Figure 3A, a pressure-holding process is carried out. That is, resin pressure is applied by the screw 18.

[0020] The cooling process is carried out, and the resin filled in the molds 13 and 14 is allowed to solidify. The metering process is carried out simultaneously with the start of the cooling process, or after a delay. In other words, the screw 18 is rotated to melt the resin and measure it. At this time, gas is supplied from the gas inlet 28 (see Figure 2), so the resin and gas are mixed. The metering process is completed when a predetermined amount of resin has been measured. Since foam-molded products take time to cool, the cooling process is generally continued for a predetermined time even after the metering process is completed. Note that in the case of foam-molded products that require a short cooling time, the cooling process may already be completed when the metering process is completed. Once the cooling process is completed, the mold opening process is carried out. That is, the mold clamping device 2 is driven to open the molds 13 and 14. The removal process is carried out to remove the molded product. The next molding cycle is started, that is, the process returns to the mold clamping process.

[0021] Next, the control of the on-off valve 35 of the gas supply device 5 will be described. The on-off valve 35 is operated in synchronization with the molding cycle of the injection molding machine 1 described above. Specifically, as shown in FIG. 3A, the on-off valve 35 is opened a specified lead time before the metering process. Then, after the metering process is completed, the on-off valve 35 is closed a specified delay time later. The specified lead time and specified delay time are set in advance by an engineer and are stored in the controller 4 as shown in FIG. 2. The controller 4 opens and closes the on-off valve 35 based on these set values, i.e., the specified lead time and the specified delay time, and the timing of the metering process in the molding cycle.

[0022] When the on-off valve 35 opens, gas is inevitably supplied from the gas inlet 28 (see FIG. 2) into the heating cylinder 17, ensuring proper mixing of the gas and resin. Because the gas is consumed in the metering process and the secondary pressure decreases, the gas inlet 28 is opened a specified advance time before the metering process to ensure a stable supply of gas. Since the gas pressure drops slightly immediately after the metering process is completed, the on-off valve 35 is left open for a specified delay time after the metering process is completed to allow the gas pressure to rise. Closing the on-off valve 35 stops the gas supply to the gas inlet 28, reliably preventing gas from flowing upstream within the heating cylinder 17 (see FIG. 2), a phenomenon known as gas leakage. Furthermore, because the on-off valve 35 is closed once during the molding cycle, vent-up, or the intrusion of resin through the gas inlet 28, is also prevented.

[0023] <Another embodiment of the molding method for foam-molded product> The molding method for foam-molded products can be modified in various ways. For example, it has been described that the opening timing of the on-off valve 35 is set to a predetermined advance time before the metering process. However, it can also be set to the start of the metering process. Also, it has been described that the closing timing of the on-off valve 35 is set to a predetermined delay time after the completion of the metering process. However, the on-off valve 35 can also be closed at the completion of the metering process. Furthermore, the opening and closing timing of the on-off valve 35 can be synchronized with the molding cycle steps themselves. Figure 3B shows such an embodiment. That is, the on-off valve 35 is set to open simultaneously with the injection step, which is one of the molding cycle steps, and to close when the cooling step is completed. Even if the opening and closing of the on-off valve 35 is thus synchronized with the molding cycle steps, substantially the same effect can be achieved.

[0024] <Method of determining the specified delay time, etc.> As explained above, the specified delay time and the specified delay time are set in the controller 4 in advance by an engineer. These times, or the process for synchronizing the opening and closing of the on-off valve 35, can be freely determined by the engineer. However, they can also be determined through advance preparation, in which the molding cycle is repeated with the on-off valve 35 open. This will be explained. In advance preparation, the on-off valve 35 is opened and maintained in the injection molding machine 1 according to this embodiment shown in Figures 1 and 2. The molding cycle is repeated several times in the injection molding machine 1. The changes in gas pressure and average changes in resin pressure during the molding cycle are then obtained. The graph in Figure 4 shows the average changes in gas pressure 41 and resin pressure 42 obtained in this manner. The graph also shows the screw position 44 and rotational speed 45 of the screw 18.

[0025] Now, let's consider the appropriate range of gas pressure. Figure 4 shows the appropriate gas pressure range 46. The appropriate range can be determined as follows. For example, the upper limit is set to a pressure that prevents excessive gas from being supplied into the heating cylinder 17 and causing backflow within the heating cylinder 17. The lower limit is set to the gas pressure necessary for proper gas supply, below which stable supply becomes difficult. As can be seen from the graph in Figure 4, the gas pressure drops sharply during the metering process and gradually rises after the metering process is completed. In other words, it takes time for the gas pressure to recover. Therefore, the timing 48 at which the gas pressure returns to the appropriate range 46 can be found, and the time from the completion of the metering process can be calculated and determined as the specified delay time.

[0026] On the other hand, it can be seen that the gas pressure does not rise significantly during the injection and pressure-holding processes. In other words, even if the on-off valve 35 (see Figure 2) is left open at all times, no sudden rise in gas pressure occurs during the injection and pressure-holding processes. Therefore, it is possible to determine that the on-off valve 35 is opened in conjunction with the injection process. In this way, it is possible to prepare in advance for a sudden drop in gas pressure during the metering process.

[0027] In this way, the timing for opening and closing the on-off valve 35 and the process for synchronizing the opening and closing of the on-off valve 35 can be determined based on fluctuations in gas pressure in the molding cycle, but they may also be determined based on fluctuations in resin pressure. For example, in Figure 4, the resin pressure becomes higher than the gas pressure after timing 49. This poses a risk of venting. Therefore, it can be determined to close the on-off valve 35 at timing 49.

[0028] Note that the graphs of gas pressure 41 and resin pressure 42 shown in Figure 4 vary greatly depending on the configuration of the injection molding machine 1, the molded product, and the resin used. For example, if the secondary gas pipe 37 (see Figure 2) is relatively long, it will take time for gas pressure 41 to increase after it drops. Alternatively, if the molded product is relatively small, the amount of resin injected is small, so fluctuations in gas pressure 41 and resin pressure 42 will also be relatively small. Therefore, when determining the specified delay time, etc., or the process for opening and closing the on-off valve 35, you should perform repeated molding cycles for the injection molding machine 1 actually used, the molded product actually molded, and the resin used, and examine the changes in gas pressure 41 and resin pressure 42.

[0029] <Injection molding machine according to the second embodiment> In the above, it has been explained that the timing for closing the on-off valve 35 is a specified delay time after the completion of the metering process, or synchronized with processes such as the metering process and the cooling process. However, it is also possible to determine the timing for closing the on-off valve 35 for each molding cycle based on the gas pressure measured by the gas pressure meter 39 or the resin pressure measured by the resin pressure sensor 30. Figure 5A shows an injection molding machine 1A according to a second embodiment in which the on-off valve 35 is operated in this manner.

[0030] In the injection molding machine 1A according to the second embodiment, three set values ​​are stored in the controller 4A: an appropriate gas pressure range, an appropriate resin pressure range, and a specified holding time. The injection molding machine 1A according to the second embodiment can determine the timing to close the on-off valve 35 using two methods. The first method is to determine the timing based on the gas pressure. After the metering process in the molding cycle is completed, the controller 4A monitors the gas pressure detected by the gas pressure gauge 39. When this gas pressure reaches the appropriate gas pressure range, the on-off valve 35 is closed. Alternatively, the on-off valve 35 is closed when the gas pressure reaches the appropriate gas pressure range and the specified holding time has elapsed.

[0031] The second method is to determine the resin pressure. After the metering process is completed in the molding cycle, the controller 4A monitors the resin pressure detected by the resin pressure sensor 30. When the resin pressure reaches the appropriate resin pressure range, the on-off valve 35 is closed. Alternatively, the on-off valve 35 is closed when the resin pressure reaches the appropriate resin pressure range and a specified holding time has elapsed.

[0032] In the above description, the timing for opening the on-off valve 35 is, for example, set a predetermined advance time before the start of the metering process. This predetermined advance time can also be adjusted for each molding cycle. For example, if the gas pressure or resin pressure is detected at the start of the metering process and is found to be outside the appropriate range, the predetermined advance time can be adjusted based on the magnitude of the deviation. For example, if the gas pressure does not reach the appropriate range at the start of the metering process, the predetermined advance time can be adjusted longer in the next and subsequent molding cycles so that the gas pressure falls within the appropriate range.

[0033] <Injection molding machine according to the third embodiment> The injection molding machine 1 according to this embodiment can be modified. FIG. 5B shows an injection molding machine 1B according to a third embodiment. In this embodiment, the gas supply device 5B is modified. The valve mechanism of the gas supply device 5B is modified. Specifically, an injection valve 51 is used instead of an on-off valve. The injection valve 51 is embedded in the heating cylinder 17 and doubles as the gas inlet 28. The gas supply device 5B is also modified in that a check valve 52 is provided in the secondary gas pipe 37 and that two gas cylinders 32, 32 are provided. Furthermore, in this second embodiment, the heating cylinder 17 is not provided with a sensor for measuring the resin pressure. The injection molding machine 1B according to the second embodiment can also be used to carry out the method for producing a foam-molded product according to this embodiment.

[0034] The present invention has been specifically described above based on the embodiments. However, the present invention is not limited to the above-described embodiments and various modifications are possible without departing from the spirit and scope of the present invention. For example, while the gas supply was controlled by the on-off valve 35 or the injection valve 51, the valves can also be controlled based on the pressure difference between the upstream and downstream sides of the check valve. In FIG. 5B, the pressure reducing valve 34 is operated after a specified delay time to reduce the supply pressure. This results in a high pressure on the downstream side of the check valve, where the gas supply port is located, and a low pressure on the pressure reducing valve side. This pressure difference closes the check valve, essentially achieving the same effect as stopping the gas supply using the on-off valve 35 or the injection valve 51. To resume the gas supply, the pressure reducing valve 34 is operated to restore the supply pressure to its original level. The above-described examples can be implemented in combination as appropriate. [Explanation of symbols]

[0035] 1 Injection molding machine 2 Mold clamping device 3 Injection unit 4 Controller 5 Gas supply device 7 Fixed platen 8 Movable platen 9 Clamping housing 11 toggle mechanism 13 mold 14 mold 17 heating cylinder 18 Screw 19 Screw drive device 21 Hopper 22 Injection nozzle 24 Supply section 25 First compression and metering section 26 Starvation section 27 Second compression / metric section 28 Gas inlet 30 Resin pressure sensor 32 Gas cylinder 34 Pressure reducing valve 35 On-off valve 36 Primary gas pipe 37 Secondary gas pipe 39 Gas pressure gauge 41 Gas pressure 42 Resin pressure 44 Screw position 45 Rotation speed 46 Appropriate gas pressure range 51 Injection valve 52 Check valve

Claims

1. a heating cylinder provided with a gas inlet; a screw drivably provided within the heating cylinder; a gas supply device for supplying gas to the gas inlet; a control means; the gas supply device includes a gas cylinder, a primary gas pipe connected to the gas cylinder, a pressure reducing valve connected to the primary gas pipe, a secondary gas pipe connected to the pressure reducing valve and through which the gas in the primary gas pipe is reduced in pressure and supplied, and a valve mechanism provided on the secondary gas pipe; The control means controls the valve mechanism to open a specified advance time before the start of the metering process and to close a specified delay time after the completion of the metering process.

2. a heating cylinder provided with a gas inlet; a screw drivably provided within the heating cylinder; a gas supply device for supplying gas to the gas inlet; a control means; the gas supply device includes a gas cylinder, a primary gas pipe to which the gas cylinder is connected, a pressure reducing valve connected to the primary gas pipe, a secondary gas pipe connected to the pressure reducing valve and through which the gas in the primary gas pipe is reduced in pressure and supplied, a valve mechanism provided in the secondary gas pipe, and a gas pressure meter provided in the secondary gas pipe to detect gas pressure; the control means controls the valve mechanism to keep it open during the metering step in the molding cycle and to close it when a specified delay time has elapsed after the metering step is completed, an injection molding machine for foam molding, wherein the specified delay time is determined based on the tendency of fluctuations in the gas pressure obtained by previously performing a plurality of molding cycles;

3. 3. The injection molding machine for foam molding according to claim 1, wherein said valve mechanism comprises an on-off valve or an injection valve.

4. 3. The injection molding machine for foam molding according to claim 1, wherein said control means opens said valve mechanism at a timing of an injection process.

5. 2. The injection molding machine for foam molding according to claim 1, wherein the secondary gas pipe of the gas supply device is provided with a gas pressure gauge for detecting gas pressure, and the specified advance time is determined based on the tendency of gas pressure fluctuations obtained by performing a plurality of molding cycles in advance.

6. 2. The injection molding machine for foam molding according to claim 1, wherein the heating cylinder is provided with a resin pressure gauge that detects the resin pressure at the gas inlet, and the specified delay time is determined based on the tendency of fluctuations in the resin pressure obtained by performing a plurality of molding cycles in advance.

7. 2. The injection molding machine for foam molding according to claim 1, wherein the heating cylinder is provided with a resin pressure gauge that detects the resin pressure at the gas inlet, and the specified advance time is determined based on the tendency of fluctuations in the resin pressure obtained by performing a plurality of molding cycles in advance.

8. 2. The injection molding machine for foam molding according to claim 1, wherein the secondary gas pipe of the gas supply device is provided with a gas pressure gauge for detecting gas pressure, and the specified advance time is adjusted for each molding cycle based on the gas pressure detected at the start of the metering step.

9. a heating cylinder provided with a gas inlet; a screw drivably provided within the heating cylinder; a gas supply device that supplies gas to the gas inlet, the gas supply device includes a gas cylinder, a primary gas pipe connected to the gas cylinder, a pressure reducing valve connected to the primary gas pipe, a secondary gas pipe connected to the pressure reducing valve and through which the gas in the primary gas pipe is reduced in pressure and supplied, and a valve mechanism provided on the secondary gas pipe; The method for molding a foam-molded product includes controlling the valve mechanism to open at a timing a specified advance time before the start of the metering process and close when a specified delay time has elapsed after the completion of the metering process, thereby supplying gas to the resin in the heating cylinder.

10. a heating cylinder provided with a gas inlet; a screw drivably provided within the heating cylinder; a gas supply device that supplies gas to the gas inlet, the gas supply device includes a gas cylinder, a primary gas pipe connected to the gas cylinder, a pressure reducing valve connected to the primary gas pipe, a secondary gas pipe connected to the pressure reducing valve and through which the gas in the primary gas pipe is reduced in pressure and supplied, a valve mechanism provided in the secondary gas pipe, and a gas pressure meter provided in the secondary gas pipe for detecting gas pressure; controlling the valve mechanism to keep it open during the metering step in the molding cycle and to close it when a specified delay time has elapsed after the completion of the metering step, thereby supplying gas to the resin in the heating cylinder; A method for molding a foam-molded product, wherein the specified delay time is determined based on the tendency of fluctuations in the gas pressure obtained by previously performing a plurality of molding cycles.

11. 11. The method for molding a foam-molded product according to claim 9 or 10, wherein the valve mechanism comprises an on-off valve or an injection valve.

12. The method for molding a foam-molded product according to claim 9 or 10, wherein the valve mechanism is opened during the injection step.

13. 10. The method for molding a foam-molded product according to claim 9, wherein a gas pressure meter for detecting gas pressure is provided in the secondary gas pipe of the gas supply device, and the specified advance time is determined based on a tendency of fluctuations in gas pressure obtained by performing a plurality of molding cycles in advance.

14. 10. The method for molding a foam-molded product according to claim 9, wherein a resin pressure meter for detecting the resin pressure at the gas inlet is provided in the heating cylinder, and the specified delay time is determined based on the tendency of fluctuations in the resin pressure obtained by performing a plurality of molding cycles in advance.

15. 10. The method for molding a foam-molded product according to claim 9, wherein a resin pressure meter for detecting the resin pressure at the gas inlet is provided in the heating cylinder, and the specified advance time is determined based on the tendency of fluctuations in the resin pressure obtained by performing a plurality of molding cycles in advance.

16. 10. The method for molding a foam-molded product according to claim 9, wherein a gas pressure meter for detecting gas pressure is provided in the secondary gas pipe of the gas supply device, and the specified advance time is adjusted for each molding cycle based on the gas pressure detected at the start of the metering step.

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