Ejection method for injection molding machines operating in semi-automatic mode

Abstract

This system enables ejection at a timing that matches the operator's needs, increasing productivity and providing an optimal ejection method for injection molding machines operating in semi-automatic mode. [Solution] After the completion of the mold opening process based on the completion of the injection filling process, when removing the molded product G from the mold C by the ejection process Pe, multiple different ejection start modes (m1…) corresponding to the start timing of the ejection process Pe are set in advance, and during molding, a predetermined ejection start mode (m1…) is selected, thereby starting the ejection process Pe according to the start timing of the selected ejection start mode (m1…).

Description

Technical Field

[0001] The present invention relates to an ejection method for an injection molding machine that performs semi-automatic operation of ejecting a molded product from a mold after the start of the mold opening process based on the end of the injection filling process.

Background Art

[0002] Generally, in the case of an injection molding machine that performs semi-automatic operation, molten resin is injected and filled into a mold cavity, and then the mold is opened and the ejector pin is projected to take out the molded product in the mold cavity. In this case, since some operations are performed manually, the timing is important, and an injection molding machine that can adjust such timing has also been proposed.

[0003] Conventionally, as this type of injection molding machine, the injection molding machine described in Patent Document 1 is known. The injection molding machine described in the document aims to enable easy adjustment of the operation timing when taking out a molded product in an injection molding machine equipped with a molded product taking-out device without making the device configuration too complicated. Specifically, in an injection molding machine equipped with a molded product taking-out device, a delay timer for setting the time from the end of the mold opening operation to the start of the operation of driving the ejector pin to push out the molded product is provided on the operation console for operation, and the set value of the time can be changed on the operation console. Preferably, in addition to this, a second delay timer for setting the time from the start of the extrusion operation by the ejector pin to the start of blowing compressed air from the front of the moving mold is provided, and the set values of each time can be changed on the operation console.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0005] However, the ejection method used in conventional injection molding machines that perform the semi-automatic operation described above had the following problems.

[0006] In other words, in semi-automatic operation, the basic operation involves opening the mold after the molding process and removing the molded product through the ejection process. Therefore, optimizing the timing of the ejection process is an important issue from the perspective of allowing the operator to check the quality of the molded product during the ejection process and from the perspective of speeding up the molding cycle.

[0007] Conventional ejection methods allow users to change settings such as the delay timer used to set the time before the ejection operation begins. While the length of this time can be adjusted, it has the drawback of not being able to optimize the timing of the ejection process, especially from the operator's perspective.

[0008] As a result, problems such as molded products being ejected too early, preventing operators from properly inspecting them, or not being ejected at a timing that matches the operator's preferences, thus preventing the shortening of the molding cycle time, have occurred. Therefore, there has been a need for further improvement of the ejection method in injection molding machines that operate semi-automatically.

[0009] The present invention aims to provide an ejection method for a semi-automatic injection molding machine that solves the problems present in the background technology described above. [Means for solving the problem]

[0010] The ejection method for a semi-automatic injection molding machine M according to the present invention solves the above-mentioned problems by, when removing the molded product G from the mold C by the ejection process Pe after the completion of the mold opening process based on the completion of the injection filling process, setting in advance multiple different ejection start modes (m1...) corresponding to the start timing of the ejection process Pe: a first mode m1 that sets the timing after the stop of the mold opening operation based on the completion of the mold opening process Po, a second mode m2 that sets the timing of the power source cutoff for the mold opening operation based on the completion of the mold opening process Po, a third mode m3 that sets the timing after the guard lock is released after the completion of the mold opening process Po, and a fourth mode m4 that sets the timing immediately after the opening of the safety door D after the completion of the mold opening process Po, and by selecting a predetermined ejection start mode (m1...) during molding, the ejection process Pe is started at the start timing of the selected ejection start mode (m1...).

[0011] In this case, according to a preferred embodiment of the invention, the selection of the ejection start mode (m1...) can be performed by the ejection start timing selection screen Vs displayed on the display 2. Furthermore, the selection of the ejection start mode (m1...) can be made in correspondence with the molded product G. In addition, the ejection process Pe can include a first motion mode in which the ejection pins 3... do not move backward when the safety door D is open, or a second motion mode in which the ejection pins 3... perform both forward and backward movements when the safety door D is open. [Effects of the Invention]

[0012] The ejection method for the injection molding machine M that performs semi-automatic operation according to the present invention yields the following remarkable effects.

[0013] (1) By setting multiple different ejection start modes (m1…) in advance to correspond to different start timings for starting the ejection process Pe, and by selecting a predetermined ejection start mode (m1…) during molding, the ejection process Pe is started at the start timing according to the selected ejection start mode (m1…). This effectively eliminates problems such as the molded product G being ejected at an early stage, preventing the operator from properly checking the molded product. Furthermore, it enables ejection at a timing that matches the operator's preference, shortening the molding cycle time and increasing productivity, thus realizing an optimal ejection method for injection molding machines M that operate semi-automatically.

[0014] (2) When setting the ejection start mode (m1...), a first mode m1 is provided to set the timing after the stop of the mold opening operation based on the end of the mold opening process Po; a second mode m2 is provided to set the timing of the power source cutoff for the mold opening operation based on the end of the mold opening process Po; a third mode m3 is provided to set the timing after the guard lock is released after the end of the mold opening process Po; and a fourth mode m4 is provided to set the timing immediately after the opening of the safety door D after the end of the mold opening process Po. This makes it possible to select four important timing points that the operator can expect from the end of the mold opening process Po to the start of the ejection process Pe. This makes it possible to select the optimal timing for the operator.

[0015] (3) In a preferred embodiment, if the ejection start mode (m1...) is selected using the ejection start timing selection screen Vs displayed on the display 2, the operator can visually confirm the selection, making it easy and reliable to select the ejection start mode (m1...).

[0016] (4) In a preferred embodiment, when selecting an ejection start mode (m1…), if the selection is made in accordance with the molded product G, the optimal ejection start mode (m1…) corresponding to the shape and type of the molded product G can be selected.

[0017] (5) In a preferred embodiment, if the ejecting process Pe includes a first motion mode in which the ejecting pin 3 does not perform a retracting operation when the safety door D is open, it is possible to correspond to a motion mode restricted by the open / closed state of the safety door D assumed for an injection molding machine M performing semi-automatic operation. Therefore, it becomes possible to select an ejecting start mode (m1…) optimal for the first motion mode, enhancing convenience.

[0018] (6) In a preferred embodiment, if the ejecting process Pe includes a second motion mode in which the ejecting pin 3 performs both a forward operation and a retracting operation when the safety door D is open, it is possible to correspond to a motion mode not restricted by the open / closed state of the safety door D assumed for an injection molding machine performing semi-automatic operation. Therefore, it becomes possible to select an ejecting start mode (m1…) optimal for the second motion mode, enhancing convenience.

Brief Description of the Drawings

[0019] [Figure 1] A flowchart for sequentially explaining the first motion mode of the ejecting method according to a preferred embodiment of the present invention, [Figure 2] A process diagram with respect to the time axis of each operation for explaining the same ejecting method, [Figure 3] A schematic diagram showing the whole injection molding machine capable of implementing the same ejecting method, [Figure 4] A selection screen diagram displayed on a display used for the same ejecting method, [Figure 5] A main part configuration diagram of an injection molding machine implementing the same ejecting method, [Figure 6] A main part configuration diagram showing one process of an injection molding machine implementing the same ejecting method, [Figure 7] A main part configuration diagram showing another process of an injection molding machine implementing the same ejecting method, [Figure 8] A flowchart for sequentially explaining the second motion mode of the same ejecting method, [Figure 9]Process diagram for each operation with respect to the time axis for the ejection method (second motion mode),

Embodiments for Carrying Out the Invention

[0020] Next, preferred embodiments according to the present invention will be given and described in detail based on the drawings.

[0021] First, the schematic configuration of an injection molding machine M that performs semi-automatic operation capable of implementing the ejection method according to the present embodiment will be described with reference to FIGS. 3 to 5.

[0022] In FIG. 3, reference numeral M denotes an injection molding machine that performs semi-automatic operation, and includes a machine base Mb, an injection device Mi, and a mold clamping device Mc installed on the machine base Mb.

[0023] The injection device Mi includes a heating cylinder 11, and an injection nozzle (not shown in the figure) is provided at the front end of the heating cylinder 11. Further, a hopper 12 for supplying material is provided at the rear part of the heating cylinder 11. On the other hand, a side panel 21 is provided near the front end of the heating cylinder 11, and a display 2 is disposed using this side panel 21.

[0024] On the other hand, as shown in FIG. 5 (FIG. 3), the mold clamping device Mc includes a mold C composed of a fixed mold Cc and a movable mold Cm. This fixed mold Cc is attached to a fixed plate 13 fixed inside near the side panel 21 described above, and the movable mold Cm is attached to a movable plate 15 that is supported by a plurality of tie bars 14... so as to be movable forward and backward. This movable plate 15 can be moved forward and backward (opened and closed) by a mold clamping cylinder 16 shown in FIG. 5. Note that 22 indicates a cylinder cover that covers the outside of the mold clamping cylinder 16.

[0025] Also, as shown in FIG. 5, one or two or more ejection cylinders 17... are built into the movable plate 15, and ejection pins 3... whose tips face the mold cavity Cg can be moved forward and backward.

[0026] Furthermore, a safety door D is provided between the side panel 21 and the cylinder cover 22. This safety door D has a window Dw attached to the door body Dp, which has a transparent plate that allows the internal mold C etc. to be viewed from the outside, and a handle Dh is provided near the end of the door body Dp on the side panel 21 side. As a result, the operator can open and close the safety door D by sliding it by operating the handle Dh.

[0027] On the other hand, Figure 5 shows the configuration of the control system X that can implement the ejection method according to this embodiment. 31 is a molding machine controller that controls the entire system. This molding machine controller 31 basically has built-in hardware such as a CPU and an internal memory (not shown) managed by this hardware. The internal memory has a data area on which various data can be written, and a program area on which various programs can be stored. In addition, this program area stores PLC programs and HMI programs, as well as various processing programs for executing various calculations and various control processes (sequence control).

[0028] Therefore, this processing program includes a program for executing the ejection method according to this embodiment. The PLC program is software for realizing the sequence operation of various processes in the injection molding machine M that performs semi-automatic operation, as well as monitoring the injection molding machine M, and the HMI program is software for realizing the setting and display of operating parameters of the injection molding machine M that performs semi-automatic operation, as well as the display of operation monitoring data of the injection molding machine M.

[0029] Furthermore, the molding machine controller 31 is connected to the display 2 via a display interface 32. The display 2 consists of a display main unit 2d that displays various information and a touch panel unit 2t attached to the display main unit 2d for various inputs, etc. The display main unit 2d can display the selection screen Vs shown in Figure 4.

[0030] Furthermore, 33 is a hydraulic circuit, and various actuators A, not shown, including the clamping cylinder 16 and ejector cylinder 17 mentioned above, are connected to the output side of this hydraulic circuit 33. Various control signals and control commands are supplied to the hydraulic circuit 33 from the molding machine controller 31, and a position sensor 35 for detecting the position (open / closed position) of the movable platen 15 and a detection sensor 36 for detecting the open / closed state (open / closed position) of the safety door D are connected to the sensor input section of the molding machine controller 31.

[0031] Next, the ejection method according to this embodiment, using an injection molding machine M that performs semi-automatic operation and has the above configuration, will be described with reference to Figures 2-7, following the flowchart shown in Figure 1.

[0032] In this embodiment, the ejection process Pe is shown in Figure 2, where the ejection pins 3... do not retract when the safety door D is open, in a first motion mode.

[0033] First, when implementing the ejection method according to this embodiment, multiple (four in this example) different start timings for starting the ejection process Pe are set.

[0034] Specifically, four ejection start modes (m1...) are set: first mode m1, second mode m2, third mode m3, and fourth mode m4 (step S1).

[0035] In this case, the first mode m1 occurs at the timing after the mold opening operation has stopped due to the completion of the mold opening process Po. This timing can be detected when the detection signal from the position sensor 35, which detects the position (open / closed position) of the movable platen 15, reaches the mold opening limit. That is, in Figure 2, the state becomes [m1], and the ejection process can be started at the earliest timing after the completion of the mold opening process Po.

[0036] The second mode m2 is the timing for shutting off the power source for the mold opening operation based on the completion of the mold opening process Po. The hydraulic circuit 33 confirms the power source shutdown state, so the ejection process is started at this timing. In Figure 2, this corresponds to position [m2], and the ejection process can be started at the next earliest timing after the completion of the mold opening process Po, following the first mode m1.

[0037] The third mode m3 occurs after the guard lock is released following the completion of the mold opening process Po. This timing can be detected by the guard lock release command signal in the molding machine controller 31, and the ejection process is started when the guard lock release command signal is detected. In Figure 2, position [m3] represents the state of the third mode m3, and the ejection process can be started at the timing of the guard lock release after the completion of the mold opening process Po.

[0038] The fourth mode m4 occurs after the opening of the safety door D following the completion of the mold opening process Po. This timing is obtained when the detection signal from the detection sensor 36, which detects the open / closed state (open / closed position) of the safety door D, indicates that the door is open. That is, in Figure 2, position [m4] represents the state of the fourth mode m4, and after the completion of the mold opening process Po, the ejection process can be started because the safety door D has opened.

[0039] By setting up multiple selectable ejection start modes (m1…), four critical timing points are available for the operator between the end of the mold opening process (Po) and the start of the ejection process (Pe), allowing the operator to select the optimal timing.

[0040] The completed ejection start mode (m1...) is registered as setting data in the molding machine controller 31 (step S2).

[0041] On the other hand, when performing the molding process, the operator selects a predetermined ejection start mode (m1...). In this case, the selection can be made using the selection screen Vs displayed on display 2, as shown as an example in Figure 4 (step S3).

[0042] In this way, by displaying the selection screen Vs on display 2, the operator can visually confirm the selection, making it easy and reliable to select the ejection start mode (m1...). Selection is made by touching the selection keys "m1" to "m4" corresponding to the desired first to fourth mode (step S4).

[0043] Furthermore, the ejection start mode (m1…) can be selected in accordance with the molded product G. This allows for the selection of the optimal ejection start mode (m1…) corresponding to the shape and type of the molded product G.

[0044] Once the selection of the ejection start mode (m1...) is complete, the injection molding process is performed (step S5). This causes molten resin to be injected and filled into the mold cavity Cg from the injection device Mi. Then, once the injection molding process is complete, the mold opening process Po is performed (step S6).

[0045] In this case, during the mold opening process Po, the mold clamping cylinder 16 is driven and controlled, causing the movable platen 15 (movable mold Cm) to move in the mold opening direction. When the mold opening process Po reaches the mold opening limit, this is detected by a detection signal from the position sensor 35 that detects the position (open / closed position) of the movable platen 15 (step S7).

[0046] In this case, if the first mode m1 is selected, the ejection process Pe is started at the timing after the mold opening operation stops based on the completion of the mold opening process Po. In the ejection process Pe, the ejection cylinders 17... are driven and controlled, and the ejection pins 3... move in the direction of ejecting the molded product G, and the molded product G is removed (steps S8, S9). Figure 7 shows the state in which the mold C is open. In Figure 2, the state is [m1], and the ejection process can be started at the earliest timing after the completion of the mold opening process Po. The start timing of the ejection process Pe in the first mode m1 is not affected by the open / closed state of the safety door D.

[0047] Furthermore, if the second mode m2 is selected, the ejection process Pe is started at the timing of the power source cutoff for the mold opening operation based on the completion of the mold opening process Po (step S10). That is, in Figure 2, the state becomes [m2], and after the completion of the mold opening process Po, the ejection process can be started at the next earliest timing after the first mode m1. The start timing of the ejection process Pe in the second mode m2 is also not affected by the open / closed state of the safety door D.

[0048] Furthermore, if the third mode m3 is selected, the ejection process Pe is started at the timing after the guard lock is released following the completion of the mold opening process Po. This timing is detected by the guard lock release command signal in the molding machine controller 31 (step S11). That is, in Figure 2, the position [m3] represents the state of the third mode m3, and the ejection process can be started at the timing of the guard lock release after the completion of the mold opening process Po. The start timing of the ejection process Pe in the third mode m3 is also not affected by the open / closed state of the safety door D.

[0049] On the other hand, if the fourth mode m4 is selected, the ejection process Pe is started at the timing after the safety door D opens following the completion of the mold opening process Po. This timing is obtained when the detection signal from the detection sensor 36, which detects the open / closed state (open / closed position) of the safety door D, indicates that the door is open (step S12). That is, the state becomes [m4] in Figure 2, and the ejection process can be started after the mold opening process Po is completed and the safety door D has opened. Figure 6 shows the state with the safety door D open.

[0050] On the other hand, if the molded product G is removed and molding continues, the safety door D is closed and the guard lock is confirmed to be locked (steps S13, S14). Also, the power is confirmed to be started and the next cycle start button is turned on (steps S15, S16). As a result, the ejector pins 3... automatically retract, the entire ejection process Pe is completed, and the series of molding cycles is finished (step S17).

[0051] If molding continues, the mold clamping process is performed again (step S18). Furthermore, upon completion of the mold clamping process, the aforementioned injection filling process is performed, in which molten resin is injected and filled into the mold cavity Cg (steps S5, S6…).

[0052] The above describes the case where semi-automatic operation is performed using the first motion mode. Including this first motion mode, that is, the first motion mode in which the eject pins 3... do not retract when the safety door D is open, it is possible to accommodate motion modes limited by the open / closed state of the safety door D that are expected in injection molding machines M performing semi-automatic operation. Therefore, it becomes possible to select the optimal eject start mode (m1...) for the said first motion mode, thereby improving convenience.

[0053] On the other hand, Figures 8 and 9 show a second motion mode in which the ejection process Pe is performed with the safety door D open and the ejection pins 3... perform both forward and backward movements. Figure 8 shows a flowchart corresponding to Figure 1, and Figure 9 shows a process diagram corresponding to Figure 2.

[0054] In the second motion mode, the start timing of the ejection process Pe is the same as in the first motion mode shown in Figure 2 above, but even when the safety door D is open, the ejection pins 3... move forward and move backward by manual push button operation (steps S8, S30).

[0055] In the second motion mode, it is possible to select the optimal ejection start mode (m1…) for the second motion mode, which is not limited by the open / closed state of the safety door D, as is expected for injection molding machines that operate semi-automatically. This improves convenience.

[0056] Therefore, according to the ejection method for a semi-automatic injection molding machine as described in this embodiment, as a basic method, multiple different ejection start modes (m1…) corresponding to different start timings for starting the ejection process Pe are set in advance, and a predetermined ejection start mode (m1…) is selected during molding. As a result, the ejection process Pe is started according to the start timing of the selected ejection start mode (m1…). This effectively eliminates problems such as the molded product G being ejected at an early stage, preventing the operator from properly checking the molded product. Furthermore, the product is ejected at a timing that matches the operator's wishes, shortening the molding cycle time and increasing productivity. Thus, an optimal ejection method can be realized for a semi-automatic injection molding machine M.

[0057] Although preferred embodiments have been described in detail above, the present invention is not limited to these embodiments, and the details of the configuration, shape, quantity, method, etc., can be arbitrarily changed, added, or deleted without departing from the spirit of the present invention.

[0058] For example, although the embodiment illustrates the case using a hydraulic injection molding machine, it can be similarly implemented with an electric injection molding machine or a pneumatic injection molding machine. Furthermore, as an example of the ejection start mode (m1...), the first mode m1 sets the timing after the stop of the mold opening operation based on the completion of the mold opening process Po, which is the optimal example; the second mode m2 sets the timing of the power source cutoff for the mold opening operation based on the completion of the mold opening process Po; the third mode m3 sets the timing after the guard lock is released after the completion of the mold opening process Po; and the fourth mode m4 sets the timing after the safety door D opens after the completion of the mold opening process Po. However, this does not preclude the addition of ejection start modes that set other start timings. In addition, the selection of the ejection start mode (m1...) can be performed using the ejection start timing selection screen Vs displayed on the display 2, but it may also be selected by other methods such as using a changeover switch. It is desirable to select the ejection start mode (m1...) in accordance with the molded product G, but it can be arbitrarily selected based on other factors such as the operator's preference or the form of the injection molding machine. On the other hand, while we have shown a case where the ejection process Pe includes a first motion mode in which the ejection pins 3... do not move backward when the safety door D is open, or a second motion mode in which the ejection pins 3... move either forward or backward when the safety door D is open, this does not exclude the case where the process is carried out using other motion modes. [Industrial applicability]

[0059] The ejection method according to the present invention can be used in various injection molding machines that perform semi-automatic operation to remove molded products from the mold by an ejection process. [Explanation of Symbols]

[0060] 2: Display, 3…: Ejection pin, M: Injection molding machine, Pe: Ejection process, Po: Mold opening process, G: Molded product, C: Mold, (m1…): Ejection start mode, m1: First mode, m2: Second mode, m3: Third mode, m4: Fourth mode, D: Safety door, Vs: Selection screen

Claims

1. An ejection method for an injection molding machine that performs semi-automatic operation to remove a molded product from a mold by an ejection process after the completion of a mold opening process based on the completion of an injection filling process, characterized in that, in advance, an ejection start mode corresponding to a plurality of different start timings for starting the ejection process is set, which includes a first mode that sets the timing after the stop of the mold opening operation based on the completion of the mold opening process, a second mode that sets the timing of the power source cutoff for the mold opening operation based on the completion of the mold opening process, a third mode that sets the timing after the guard lock is released after the completion of the mold opening process, and a fourth mode that sets the timing after the safety door is opened after the completion of the mold opening process, and by selecting a predetermined ejection start mode during molding, the ejection process is started according to the start timing of the selected ejection start mode.

2. The ejection method for an injection molding machine performing semi-automatic operation according to claim 1, characterized in that the selection of the ejection start mode is performed by an ejection start timing selection screen displayed on the display.

3. The ejection method for an injection molding machine performing semi-automatic operation according to claim 1, characterized in that the selection of the ejection start mode is selected in accordance with the molded product.

4. The ejection method for an injection molding machine performing semi-automatic operation according to claim 1, characterized in that the ejection step includes a first motion mode in which the ejection pin does not retract when the safety door is open.

5. The ejection method for an injection molding machine performing semi-automatic operation according to claim 1, characterized in that the ejection step includes a second motion mode in which the ejection pin performs both forward and backward movements while the safety door is open.

Images