Injection molding machine and injection molding system

Abstract

An injection molding machine with a screw-type cylinder is designed to continuously receive the resin material to be molded. [Solution] The injection molding machine 10 has a heating cylinder 12 that continuously receives resin inward from the receiving section 121, feeds the resin forward by rotating the screw 122, and feeds the resin that has been fed forward outward by advancing the screw 122, and even when the screw 122 is advancing, the screw 122 is rotated in the same direction as when the resin is fed forward.

Description

Technical Field

[0001] The present invention relates to an injection molding machine and an injection molding system.

Background Art

[0002] There may be a case where an output device that removes contaminants contained in the resin to be recycled and outputs it as molten resin and an injection molding machine that performs injection molding receiving the supply of the output molten resin are connected by piping (for example, Patent Document 1). Among such injection molding machines, there is one provided with a screw-type cylinder that receives the resin output from the output device from the receiving portion to the inside, rotates the screw mounted inside to feed it forward, and advances the screw to send it out to the outside. In such a screw-type cylinder, when the screw is advanced, the rotation of the screw stops.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] While the rotation of the screw mounted inside the screw-type cylinder is stopped, the flow of the resin existing inside the cylinder stops, and the resin stays in the cylinder. At this time, when the output device continuously outputs the resin, the pressure applied to the receiving portion of the cylinder that receives the resin output from the output device increases. And when resin exceeding the amount that the cylinder can receive is about to be sent into the inside of the cylinder, a situation such as molten resin leaking from the gap of the cylinder may occur.

[0005] The object of the present invention is to enable an injection molding machine having a screw-type cylinder to continuously accept resin, which is to be used as the molding material. [Means for solving the problem]

[0006] The injection molding machine of the present invention, completed with this objective in mind, has a heating cylinder that continuously receives resin inward from a receiving section, feeds the resin forward by rotating a screw, and feeds the resin that has been fed forward outward by advancing the screw, and is characterized in that even when the screw is being advanced, the screw is rotated in the same direction as when the resin is being fed forward. The system may further include a screw control means for controlling the rotational speed of the screw. Furthermore, the screw control means may be characterized by controlling the rotational speed of the screw when the resin is dispensed so that it is approximately the same as the rotational speed of the screw when a predetermined amount of the resin is metered. Furthermore, the screw control means may be characterized by changing the rotational speed of the screw in accordance with the change in the amount of resin received into the heating cylinder, so that the amount of resin discharged from the heating cylinder is approximately the same as the amount received. The screw control means may further include a pressure measuring means for measuring the pressure applied to the resin receiving portion, and the screw control means may be characterized by controlling the rotational speed of the screw according to the magnitude of the measured pressure. Furthermore, the screw control means may be characterized by performing control to increase the rotational speed when the measured pressure is greater than a predetermined value, and performing control to decrease the rotational speed when it is less than that value. Furthermore, the injection molding system of the present invention, completed for the purpose of this invention, includes an output device that outputs resin, and an injection molding machine that receives the outputted resin, heats and melts it, injects it into a mold, and molds the resin in the mold, wherein the injection molding machine has a heating cylinder that continuously receives the resin inward from a receiving section, feeds the resin forward by rotating a screw, and feeds the resin that has been fed forward outward by advancing the screw, and is characterized in that even when the screw is being advanced, the screw is rotated in the same direction as when the resin is being fed forward. [Effects of the Invention]

[0007] According to the present invention, an injection molding machine having a screw-type cylinder can continuously receive resin, which is to be used as the molding material. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows an example of the overall configuration of the injection molding system according to this embodiment. [Figure 2] Figure 1 is a graph showing the time course of screw control by the screw control unit. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below with reference to the attached drawings. <Configuration of injection molding system 1> Figure 1 shows an example of the overall configuration of the injection molding system 1 according to this embodiment. The injection molding system 1 shown in Figure 1 is a system configured to include an injection molding machine 10 that performs injection molding of molded products made of resin, an output device 20 that continuously outputs resin toward the injection molding machine 10, and a connecting pipe 30 that connects the output device 20 and the injection molding machine 10. In the injection molding system 1, the resin that will be used as the molding material is output from the output device 20 toward the injection molding machine 10, so the injection molding machine 10, as seen from the output device 20, is located downstream.

[0010] The injection molding machine 10 and the output device 20 are connected by a connecting pipe 30. The connecting pipe 30 is a metal pipe with a bent section, and a space 31 is formed inside that serves as a flow path for the resin output from the output device 20. Therefore, the connecting pipe 30 has heat resistance and pressure resistance for the flow of resin. Furthermore, the inner surface of the connecting pipe 30 is smooth, and it has a non-stagnation structure that prevents resin from accumulating. The upstream end of the connecting pipe 30 is connected to the output device 20, and the downstream end is connected to the injection molding machine 10. Therefore, as shown by the arrow in Figure 1, the resin output from the output device 20 flows through the connecting pipe 30 before being received by the injection molding machine 10. In this embodiment, the resin output from the output device 20 may be a molten resin, which is a fluid, or it may be a solid resin crushed into chip-like pieces called pellets.

[0011] [Injection molding machine 10] As described above, the injection molding machine 10 is a molding machine used for manufacturing molded products made of resin. The injection molding machine 10 is connected to the output device 20 via a connecting pipe 30. Therefore, the injection molding machine 10 receives the resin output from the output device 20 via the connecting pipe 30, enabling the manufacture of molded products using the received resin as the material. The injection molding machine 10 includes an injection device 11 and a mold 50.

[0012] (Injection device 11) The injection device 11 is a device that heats the resin, which is the molding material, measures the molten resin, and injects a predetermined amount of resin into the inside of the mold 50. The injection device 11 includes a heating cylinder 12 that heats and measures the resin, and an injection cylinder 13 that receives the resin delivered from the heating cylinder 12 and injects it into the inside of the mold 50.

[0013] The heating cylinder 12 has a receiving section 121 for receiving resin. The receiving section 121 is located on the upstream side in the direction of the centerline of the heating cylinder 12 and receives the resin that has flowed through the connecting pipe 30 into the inside of the heating cylinder 12. The end of the connecting pipe 30 is connected to a hole provided in the heating cylinder 12 at the receiving section 121.

[0014] The receiving section 121 only needs to be able to receive the resin that has flowed through the connecting pipe 30 into the inside of the heating cylinder 12, so its configuration is not particularly limited. For example, the end of the connecting pipe 30 and the receiving section 121 of the heating cylinder 12 may be connected using a connecting member such as a joint (not shown). Alternatively, for example, the end of the connecting pipe 30 and the receiving section 121 of the heating cylinder 12 may be connected by welding.

[0015] Furthermore, the heating cylinder 12 has a screw 122 on its inside. The screw 122 moves forward (downstream in the direction of the centerline) by rotating. At this time, the metering unit 126 of the heating cylinder 12 measures the amount of resin that is moved forward by the rotation of the screw 122. As a result, a predetermined amount of resin is sent forward inside the heating cylinder 12. When the predetermined amount of resin accumulates near the outlet 124 inside the heating cylinder 12, the screw 122 moves forward toward the downstream in the direction of the centerline. Then, the resin accumulated near the outlet 124 is pressurized by the tip 123 of the screw 122 and sent out to the outside from the outlet 124.

[0016] The control of the screw 122 in the heating cylinder 12 is performed by a screw control unit 125 as screw control means. The screw control unit 125 enables, for example, control of the screw rotation, control of the movement in the center line direction (forward and backward), etc. as the control of the screw 122. Details of the control of the screw 122 by the screw control unit 125 will be described later.

[0017] Further, the heating cylinder 12 has a band heater 127 for heating the heating cylinder 12. The band heater 127 is composed of, for example, a lightweight and thin cylindrical heater in which a nichrome wire is insulated with a heat-resistant mica plate and covered with a stainless steel plate, and is arranged on the outer peripheral surface of the heating cylinder 12. Therefore, the heating cylinder 12 heats the resin inside by using the heat emitted from the band heater 127.

[0018] Also, the heating cylinder 12 has a pressure measurement unit 128 as pressure measurement means for measuring the pressure applied to the resin receiving portion 121 output from the output device 20. The pressure measurement unit 128 is composed of a pressure gauge, a pressure sensor, etc. The magnitude of the pressure measured by the pressure measurement unit 128 is used, for example, as information for the screw control unit 125 to control the screw rotation of the screw 122. Based on the magnitude of the pressure measured by the pressure measurement unit 128, it is also possible to estimate the amount of resin received by the heating cylinder 12.

[0019] A pipe 129 for flowing the resin sent out from the heating cylinder 12 is arranged at the downstream end of the heating cylinder 12 in the center line direction. The pipe 129 is a metal pipe having a bent portion, and a space 130 serving as a flow path for flowing the resin sent out from the heating cylinder 12 is formed inside. Therefore, the pipe 129 has heat resistance and pressure resistance for flowing the resin. Further, the inner surface of the pipe 129 is smooth and has a non-stagnant structure in which resin is not likely to stay.

[0020] The injection cylinder 13 receives the resin fed from the heating cylinder 12 through the pipe 129 inside. Then, the plunger 131 disposed inside the injection cylinder 13 advances toward the downstream side in the center line direction, thereby pressurizing the resin filled in the injection cylinder 13. As a result, the resin pressurized by the plunger 131 is injected outward from the injection port 132. Specifically, as shown by the arrow in FIG. 1, resin injection is performed with the injection port 132 of the injection cylinder 13 in contact with the mold 50.

[0021] (Mold 50) The mold 50 has a sprue 51 which is a flow path into which the resin injected from the injection cylinder 13 flows, and an inlet 52 thereof. When the resin is injected from the injection port 132 with the injection port 132 of the injection cylinder 13 and the inlet 52 of the sprue 51 in contact, the injected resin flows through the sprue 51 and into the inside of the mold 50. The mold 50 forms the resin flowing into the inside by means of a mold opening and closing operation, cools and solidifies it, thereby completing a molded product (for example, a product, a preform of a product). The mold opening and closing operation of the mold 50 is performed by a mold clamping device not shown.

[0022] 〔Output device 20〕 The output device 20 is a device that outputs resin toward the injection molding machine 10 as described above. The output device 20 may be one that removes contaminants contained inside the resin such as a PET bottle to be recycled by, for example, mechanical recycling (physical recycling method) or chemical recycling (chemical recycling method), and outputs it as molten resin. The output device 20 is connected to the connecting pipe 30. For this reason, the resin output from the output device 20 is received by the heating cylinder 12 of the injection device 11 of the injection molding machine 10 through the connecting pipe 30.

[0023] Here, "mechanical recycling" refers to a series of processes in which the collected used PET bottles and other resins are exposed to high temperatures to become molten resin, and any contaminants remaining inside are diffused into the vacuum inside the output device 20 for decontamination. "Chemical recycling," on the other hand, refers to a series of processes in which the collected used PET bottles and other resins are sorted, chemically decomposed, and repolymerized to decontaminate them.

[0024] <Control of screw 122> As described above, the heating cylinder 12, which constitutes the injection device 11 of the injection molding machine 10, heats the resin received inside by the receiving section 121 and sends it forward (downstream in the direction of the centerline) by the rotation of the screw 122. At this time, the heating cylinder 12 measures the amount of resin being sent forward inside the heating cylinder 12. When a predetermined amount of resin has accumulated near the outlet 124 inside the heating cylinder 12, the heating cylinder 12 advances the screw 122 and sends the resin outwards from the outlet 124.

[0025] Here, the screw 122 rotates in the same way as when the resin is being metered, even when it is moving forward to discharge the resin from the outlet 124. That is, the screw control unit 125 of the heating cylinder 12 rotates the screw 122 in the same direction as the rotation of the screw 122 when the resin is being metered by the metering unit 126, while moving the screw 122 forward to discharge the resin from the outlet 124. In other words, even when the screw 122 moves forward to discharge the resin from the outlet 124, a state is maintained in which the resin can be sent from the rear (upstream side in the direction of the centerline) to the front (downstream side in the direction of the centerline) of the heating cylinder 12.

[0026] The screw control unit 125 of the heating cylinder 12 enables various controls for the screw 122. For example, the screw control unit 125 can control the rotational speed of the screw 122 when the resin is being weighed by the weighing unit 126 and when the screw 122 is moving forward to dispense the resin, so that they are approximately the same. Here, "approximately the same rotational speed" means that there is no difference in the rotational speed of the screw 122 when the resin is being weighed and when the resin is being dispensed, or that there is a difference in rotational speed, but that difference is negligible.

[0027] Furthermore, for example, the screw control unit 125 can change the rotational speed of the screw 122 in accordance with the change in the amount of resin received into the receiving section 121 of the heating cylinder 12, thereby controlling the amount of resin received and the amount of resin discharged from the heating cylinder 12 to be approximately the same. Here, "approximately the same amount of resin received and discharged" means that the amount of resin received and the amount of resin discharged are identical, or that there is a difference between the amount of resin received and the amount of resin discharged, but that difference is negligible.

[0028] Furthermore, for example, the screw control unit 125 can control the rotational speed of the screw 122 according to the magnitude of the pressure applied to the receiving section 121, as measured by the pressure measuring unit 128. For example, if the magnitude of the pressure measured by the pressure measuring unit 128 becomes greater than a predetermined magnitude, the screw control unit 125 will perform control to increase the rotational speed of the screw 122. Also, if the magnitude of the pressure measured by the pressure measuring unit 128 becomes less than a predetermined magnitude, the screw control unit 125 will perform control to decrease the rotational speed of the screw 122. Here, the predetermined magnitude of the pressure may not be just one value but may have a range.

[0029] Figure 2 is a graph showing the time course of the control of the screw 122 by the screw control unit 125 in Figure 1. In the graph in Figure 2, the horizontal axis represents time (t). Time zones t1 and t3 indicate the time periods when the resin is being measured by the metering unit 126 of the heating cylinder 12 in Figure 1, respectively. Time zones t2 and t4 indicate the time periods when the resin is being dispensed from the heating cylinder 12 and filled into the injection cylinder 13 in Figure 1, respectively.

[0030] Furthermore, in the graph of Figure 2, the vertical axis represents one of the following: the rotational speed of the screw 122 of the heating cylinder 12 in Figure 1, the position of the screw 122 in the direction of the centerline within the heating cylinder 12, or the pressure applied to the receiving portion 121 of the heating cylinder 12. Line L1 shows the change in the position of the screw 122 in the direction of the centerline within the heating cylinder 12 over time. In this case, the further up the vertical axis you go, the further upstream (rearward) the position of the screw 122 in the direction of the centerline is located, and the further down the vertical axis you go, the further downstream (front) the position of the screw 122 in the direction of the centerline is located.

[0031] As shown in Figure 2, the shape of line L1 in time periods t1 and t3 is a straight line extending upwards to the right of the graph. Also, the shape of line L1 in time periods t2 and t4 is a straight line extending downwards to the right of the graph. This is because, in time periods t1 and t3 when the resin is metered, the position of the screw 122 in the direction of the centerline is controlled to move backward from the downstream side (front) to the upstream side (rear). Also, in time periods t2 and t4 when the resin is filled into the injection cylinder 13, the position of the screw 122 in the direction of the centerline is controlled to move forward from the upstream side (rear) to the downstream side (front).

[0032] Furthermore, line L2 shows the time change in the magnitude of the pressure applied to the resin receiving section 121, which is output from the output device 20 in Figure 1, as measured by the pressure measuring unit 128 of the heating cylinder 12 in Figure 1. In this case, the vertical axis of the graph in Figure 2 indicates that the pressure applied to the receiving section 121 is greater as you move upwards. The magnitude of the pressure applied to the receiving section 121 is controlled to be constant by controlling the rotational speed of the screw 122.

[0033] Furthermore, line L3 shows the time change in the rotational speed of screw 122. In this case, the vertical axis of the graph in Figure 2 indicates that the rotational speed of screw 122 is faster as it moves upward. The rotational speed of screw 122 is controlled according to the magnitude of the pressure applied to the receiving section 121. That is, the rotational speed of screw 122 is controlled so that it is proportional to the pressure applied to the receiving section 121. For this reason, the shape of line L3 is similar to the shape of line L2. This is because when the pressure applied to the receiving section 121 increases, the rotational speed of screw 122 increases accordingly, and when the pressure applied to the receiving section 121 decreases, the rotational speed of screw 122 decreases accordingly. In other words, when the pressure applied to the receiving section 121 increases, the rotational speed of screw 122 is controlled to increase accordingly. This makes it easier for the resin received by the receiving section 121 of the heating cylinder 12 to flow downstream (forward). As a result, the pressure on the receiving section 121 decreases and returns to its original level.

[0034] Conversely, if the pressure applied to the receiving section 121 decreases, resin backflow may occur. Therefore, the rotation speed of the screw 122 is controlled to decrease in accordance with the decrease in pressure applied to the receiving section 121. This makes it difficult for the resin received by the receiving section 121 of the heating cylinder 12 to flow downstream (forward). As a result, the pressure applied to the receiving section 121 increases and returns to its original level. In this way, the rotation speed of the screw 122 is controlled according to the magnitude of the pressure applied to the receiving section 121 of the heating cylinder 12. As a result, the pressure applied to the receiving section 121 is controlled to remain constant according to the pressure applied to the receiving section 121, as shown by line L2 in the graph of Figure 2.

[0035] In the time period t1 shown in the graph of Figure 2, the metering unit 126 of the heating cylinder 12 measures the resin. Also, the screw control unit 125 in Figure 1 rotates the screw 122 in the direction of sending the resin downstream (forward) in the direction of the centerline, while simultaneously retracting the screw 122 from the downstream side to the upstream side in the direction of the centerline. Furthermore, in the time period t11 of time period t1, the screw control unit 125 changes the rotation speed of the screw 122 in response to a sudden change in the pressure applied to the receiving unit 121. As a result, the pressure applied to the receiving unit 121 returns to its original level.

[0036] Furthermore, during the time period t2 shown in the graph of Figure 2, the screw control unit 125 rotates the screw 122 in the direction of sending resin downstream (forward) in the direction of the centerline, while simultaneously advancing the screw 122 downstream in the direction of the centerline. As a result, resin is sent out from the outlet 124 of the heating cylinder 12, flows through the piping 129, and fills the injection cylinder 13. In addition, the screw control unit 125 changes the rotation speed of the screw 122 in response to sudden changes in the pressure applied to the receiving section 121. As a result, the pressure applied to the receiving section 121 returns to its original level.

[0037] Furthermore, during time period t3 shown in the graph of Figure 2, the metering unit 126 of the heating cylinder 12 measures the resin. The screw control unit 125 rotates the screw 122 in the direction of sending the resin downstream (forward) in the direction of the centerline, while simultaneously retracting the screw 122 from the downstream side to the upstream side in the direction of the centerline. In addition, during time period t31 within time period t3, the screw control unit 125 changes the rotation speed of the screw 122 in response to a sudden change in the pressure applied to the receiving unit 121. As a result, the pressure applied to the receiving unit 121 returns to its original level. Thereafter, although not shown in the figures, similar control is repeated.

[0038] As described above, in the injection molding system 1 of Figure 1, resin is continuously output from the output device 20, flows through the connecting pipe 30, and is constantly supplied to the injection device 11 of the injection molding machine 10. For this reason, the screw control unit 125, which constitutes the heating cylinder 12 of the injection device 11, controls the position of the screw 122 in the direction of the centerline and rotates the screw 122 in the direction of supplying resin downstream (forward) in the direction of the centerline. The rotation of the screw 122 continues as long as the amount of resin supplied to the heating cylinder 12 does not become zero.

[0039] Furthermore, the screw control unit 125 changes the rotational speed of the screw 122 in response to changes in the pressure applied to the receiving section 121, controlling it so that the pressure applied to the receiving section 121 returns to its original level. This allows the heating cylinder 12 to continuously receive the resin, and as a result, leakage of molten resin from gaps in the heating cylinder 12, which may occur, for example, when the pressure of the resin applied to the receiving section 121 of the heating cylinder 12 increases, is suppressed.

[0040] <Variation> As described above, the injection device 11 according to this embodiment is a so-called pre-plunger type (also called pre-plunger type) injection device, which combines an independent heating cylinder 12 and an injection cylinder 13. However, the pre-plunger type injection device 11 according to this embodiment is merely illustrative. For example, an in-line screw type injection device in which heating and injection are performed in a single cylinder may also be used.

[0041] In the case of an inline screw injection system, as in the embodiment described above, resin is continuously output from the output device and constantly fed into the cylinder. As long as the amount of resin being fed into the cylinder does not become zero, the screw continues to rotate in the direction of feeding resin downstream (forward) in the direction of the centerline. This allows the cylinder of an inline screw injection system to continuously receive resin.

[0042] Furthermore, in this embodiment, as shown in Figure 1, the pressure measuring unit 128 of the heating cylinder 12 measures the pressure near the receiving section 121. This reduces the need to consider the amount of energy lost (pressure loss in the piping) when the resin output from the output device 20 flows through the connecting pipe 30. However, the position where the pressure measuring unit 128 measures the pressure is not limited to the vicinity of the receiving section 121. For example, prioritizing ease of measurement over the measured pressure value, the pressure may be measured at any position in the connecting pipe 30, or at any position in the output device 20.

[0043] In summary, the injection molding machine 10 according to this embodiment only needs to have the following configuration, and various different embodiments can be adopted. In other words, the injection molding machine 10 has a heating cylinder 12 that continuously receives resin inward from a receiving section 121, feeds the resin forward by rotating a screw 122, and feeds the resin that has been fed forward outward by advancing the screw 122, and is characterized in that even when the screw 122 is advancing, the screw 122 is rotated in the same direction as when the resin is fed forward.

[0044] In other words, even if the resin continuously output from the output device 20 is constantly being fed into the receiving section 121 of the heating cylinder 12, the rotation of the screw 122 pushes the received resin forward. This prevents the resin from accumulating near the receiving section 121 of the heating cylinder 12. As a result, the pressure on the receiving section 121 is suppressed, thus preventing situations such as resin leaking from the heating cylinder 12.

[0045] The present invention may further feature a screw control unit 125 as a screw control means for controlling the rotational speed of the screw 122. In other words, the screw control unit 125 controls the rotational speed of the screw 122. By changing the rotational speed of the screw 122, the screw control unit 125 suppresses the accumulation of resin near the receiving section 121.

[0046] Furthermore, the screw control unit 125 may be characterized by controlling the rotational speed of the screw 122 when the resin is dispensed so that it is approximately the same as the rotational speed of the screw 122 when a predetermined amount of resin is metered. In other words, the rotational speed of the screw 122 when the resin is dispensed is controlled to be approximately the same as the rotational speed of the screw 122 when a predetermined amount of resin is metered. This makes it possible to maintain a constant pressure on the receiving section 121 of the heating cylinder 12. As a result, situations such as resin leakage from the heating cylinder 12 are suppressed.

[0047] Furthermore, the screw control unit 125 may be characterized by changing the rotational speed of the screw 122 in accordance with the change in the amount of resin received into the heating cylinder 12, so that the amount of resin discharged from the heating cylinder 12 is approximately the same as the amount of resin received into the heating cylinder 12. In other words, the rotation speed of the screw 122 changes according to the amount of resin received into the heating cylinder 12, and the amount of resin received and the amount of resin discharged are controlled to be approximately equal. This allows the flow rate of resin in the heating cylinder 12 to be adjusted. As a result, situations such as resin leakage from the heating cylinder 12 are suppressed.

[0048] Furthermore, the system may also include a pressure measuring unit 128 that measures the pressure applied to the resin receiving unit 121, which is continuously output from the output device 20, and the screw control unit 125 may be characterized by controlling the rotational speed of the screw 122 according to the magnitude of the measured pressure.

[0049] Furthermore, the screw control unit 125 may also be characterized by controlling the rotation speed of the screw 122 to increase when the magnitude of the pressure measured by the pressure measuring unit 128 exceeds a predetermined magnitude. In other words, when the measured pressure increases, the rotation speed of the screw 122 increases accordingly, and when the measured pressure decreases, the rotation speed of the screw 122 decreases accordingly. This ensures that the magnitude of the measured pressure remains constant regardless of how it changes over time. As a result, situations such as resin leakage from the heating cylinder 12 are suppressed.

[0050] Furthermore, the injection molding system 1 according to this embodiment only needs to have the following configuration, and various different embodiments can be adopted. In other words, the injection molding system 1 includes an output device 20 that outputs resin, and an injection molding machine 10 that receives the output resin, heats and melts it, injects it into a mold 50, and molds the resin in the mold 50. The injection molding machine 10 has a heating cylinder 12 that continuously receives resin inward from a receiving section 121, feeds the resin forward by rotating a screw 122, and feeds the resin that has been fed forward outward by advancing the screw 122. The injection molding system is characterized in that even when the screw 122 is advancing, the screw 122 is rotated in the same direction as when the resin is fed forward. [Explanation of Symbols]

[0051] 1…Injection molding system, 10…Injection molding machine, 11…Injection device, 12…Heating cylinder, 13…Injection cylinder, 20…Output device, 30…Connecting pipe, 50…Mold, 51…Sprue, 52…Inlet, 121…Receiving inlet, 122…Screw, 123…Tip, 124…Outlet, 125…Screw control unit, 126…Measuring unit, 127…Band heater, 128…Pressure measurement unit, 129…Piping, 131…Plunger, 132…Injection port

Claims

1. A heating cylinder that continuously receives resin inward from a receiving section, moves the resin forward by rotating a screw, and sends the resin that has been moved forward outward by advancing the screw, It has, An injection molding machine characterized in that, even when the screw is being advanced, the screw is rotated in the same direction as when the resin is being fed forward.

2. The system is further characterized by having a screw control means for controlling the rotational speed of the screw. The injection molding machine according to claim 1.

3. The screw control means is characterized by controlling the rotational speed of the screw when the resin is dispensed so that it is approximately the same as the rotational speed of the screw when a predetermined amount of the resin is metered. The injection molding machine according to claim 2.

4. The screw control means is characterized by changing the rotational speed of the screw in accordance with the change in the amount of resin received into the heating cylinder, so that the amount of resin discharged from the heating cylinder is approximately the same as the amount received. The injection molding machine according to claim 2.

5. The system further includes a pressure measuring means for measuring the pressure applied to the receiving portion of the resin, The screw control means is characterized by controlling the rotational speed of the screw according to the measured magnitude of the pressure. The injection molding machine according to claim 2.

6. The screw control means is characterized in that when the measured pressure exceeds a predetermined value, it performs control to increase the rotational speed, and when it falls below that value, it performs control to decrease the rotational speed. The injection molding machine according to claim 5.

7. The system includes an output device that outputs resin, and an injection molding machine that receives the output resin, heats and melts it, injects it into a mold, and molds the resin in the mold. The injection molding machine is, A heating cylinder that continuously receives the aforementioned resin inward from the receiving section, moves the resin forward by rotating a screw, and sends the resin that has been moved forward outward by advancing the screw, It has, The screw is characterized in that, even when it is being advanced, the screw is rotated in the same direction as when the resin is being fed forward. Injection molding system.

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