Injection molding machine control device, injection molding machine, injection molding system, and injection molding machine control method

Abstract

To provide a controller of an injection molding machine, an injection molding machine, an injection molding system, and a method for controlling an injection molding machine capable of effectively reducing the risk of damage to a mold assembly.SOLUTION: A controller is used for an injection molding machine and has a control unit. A mold assembly 101 mounted on the injection molding machine has a movable protruding part 104 which is forwardly / backwardly displaceable to / from an inner space Si of the mold assembly 101 and protrudes into the inner space Si by a forward displacement. The injection molding machine is provided with a protrusion driving device 41 for driving the movable protruding part 104 of the mold assembly 101, and controls the protrusion driving device 41 so that a protruding amount into the internal space Si of the movable protruding part 104 of the mold assembly 101 is limited on the basis of an allowable set value by the control unit.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a control device for an injection molding machine equipped with an ejection drive device that drives a movable ejection portion of a mold device, an injection molding machine, an injection molding system, and a control method for an injection molding machine. [Background technology]

[0002] An example of this type of injection molding machine is described in Patent Document 1.

[0003] Patent Document 1 discloses an injection molding machine including: "a clamping device including a platen on which a mold is attached; and an ejector device which ejects a molded product from the mold, the ejector device having an ejector rod, an ejector crosshead to which the ejector rod is connected, and a drive mechanism for moving the ejector crosshead back and forth, the platen having an opening for connecting the ejector rod and the ejector crosshead, the opening allowing access from an external space of the platen to an internal space of the platen and allowing access in a direction perpendicular to a mold opening / closing direction, and a switch cover switchable between a first state which allows access from the external space to the internal space via the opening and a second state which prevents lubricant from scattering from the internal space to the external space via the opening." Patent document 1 states, "The movable mold part 840 is arranged inside the fixed mold part 830 so that it can freely move forward and backward. The movable mold part 840 includes, for example, a plate-shaped ejector plate 841 perpendicular to the mold opening and closing direction, and a rod-shaped ejector pin 844 extending forward from the ejector plate 841." and "The ejector device 200 performs the ejection process under the control of the control device 700. In the ejection process, the ejector rod 210 is advanced from the standby position to the ejection position at a set moving speed, thereby advancing the movable mold part 840 and ejecting the molded product." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-108926 A Summary of the Invention [Problem to be solved by the invention]

[0005] An injection molding machine to which a mold assembly having a movable protrusion such as the above-mentioned "ejector pin" is attached is provided with an ejection drive device such as an "ejector assembly" that drives the movable protrusion.

[0006] In such an injection molding machine, when the ejection drive device drives the movable ejection part to eject into the internal space of the mold device when the mold device is in the mold clamping state due to an incorrect setting of the injection molding operation by the user, the movable ejection part may collide with the inner surface of the mold device, which may damage the mold device.

[0007] In particular, when the mold clamping device compresses the molding material between the fixed mold and movable mold of the mold device, or when the ejection drive device ejects and compresses the molding material at the movable protrusion, the risk of damage to the mold device due to the movement of the movable protrusion described above may become apparent.

[0008] The present invention has as its objective the solving of such problems, and its purpose is to provide an injection molding machine control device, an injection molding machine, an injection molding system, and a control method for an injection molding machine that can effectively reduce the risk of damage to the mold device. [Means for solving the problem]

[0009] One control device that can solve the above-mentioned problems is used in an injection molding machine and has a control unit, wherein a mold device attached to the injection molding machine has a movable protrusion that can be displaced back and forth relative to the internal space of the mold device and protrudes into the internal space by forward displacement, the injection molding machine is equipped with an protrusion drive device that drives the movable protrusion of the mold device, and the control unit controls the protrusion drive device so that the amount of protrusion of the movable protrusion of the mold device into the internal space is limited based on an allowable set value.

[0010] The injection molding machine includes the above-mentioned control device and the ejection drive device.

[0011] The injection molding system includes the above-mentioned injection molding machine and a mold device attached to the injection molding machine.

[0012] One control method for an injection molding machine that can solve the above-mentioned problems includes a mold device attached to the injection molding machine, which has a movable protrusion that can be displaced back and forth relative to the internal space of the mold device and protrudes into the internal space by forward displacement, the injection molding machine is equipped with an protrusion drive device that drives the movable protrusion of the mold device, and the method includes controlling the protrusion drive device so that the amount of protrusion of the movable protrusion of the mold device into the internal space is limited based on an allowable set value. Effect of the Invention

[0013] According to the above-described control device and control method for an injection molding machine, the risk of damage to the mold device can be effectively reduced. [Brief description of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view showing an injection molding machine in which a control device according to an embodiment of the present invention can be used, together with a mold device attached to the injection molding machine. [Diagram 2] 1 is a block diagram showing a control device according to an embodiment of the present invention; [Diagram 3]2 is an enlarged cross-sectional view of a mold device and a main part of the injection molding machine, showing an example of an injection molding operation using the injection molding machine of FIG. 1. [Figure 4] FIG. 4 is a cross-sectional view showing the operation following that shown in FIG. [Diagram 5] 5 is a cross-sectional view showing the operation following that shown in FIG. 4. [Figure 6] FIG. 6 is a cross-sectional view showing the operation following that of FIG. 5. [Figure 7] FIG. 7 is a cross-sectional view showing the operation following that shown in FIG. [Figure 8] 8 is a cross-sectional view showing the operation following that shown in FIG. 7. [Figure 9] 3 is a diagram showing a part of a setting screen that can be displayed on a display unit of the control device of FIG. 2. [Figure 10] 3 is a cross-sectional view showing an example of dimensions of a mold device that can be included in mold information that can be input to an input unit of the control device of FIG. 2. [Figure 11] 11 is a cross-sectional view showing another example of dimensions of a mold device that can be included in the mold information that can be input to the input unit of the control device of FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. A control device according to an embodiment of the present invention can be used in, for example, an injection molding machine 1 as shown in Fig. 1. The injection molding machine 1 in Fig. 1 generally includes an injection device 11 that melts a molding material such as a thermoplastic resin and injects it into a mold device 101 by rotating and advancing a screw 13 arranged inside and heating a heater 14 arranged around the device, a moving device 21 that moves the injection device 11 forward and backward relative to the mold device 101, a mold clamping device 31 that moves the mold device 101 between a mold open state and a mold clamping state to open and close the mold device 101, and an ejection driving device 41 that drives a movable ejection portion 104 of the mold device 101.

[0016] (ejection drive device) The ejection drive device 41 drives the movable ejection portion 104 of the mold device 101. In addition to the movable ejection portion 104, the mold device 101 may have a fixed mold 102 and a movable mold 103 that are attached to the fixed platen 32a and the movable platen 32b of the mold clamping device 31, respectively, and define an internal space Si including a cavity therein when the mold device 101 is in a mold clamping state. The mold device 101 can be attached to the injection molding machine 1 and replaced as appropriate depending on the shape of the molded product to be manufactured, and is not considered to be a part of the injection molding machine 1. Note that an apparatus including the injection molding machine 1 and the mold device 101 attached to the injection molding machine 1 is referred to as an injection molding system here.

[0017] Here, as shown in Fig. 3, the movable protrusion 104 of the mold device 101 is, for example, pin-shaped or rod-shaped, located inside the movable mold 103 on the movable mold 103 side and extending through at least a part of the movable mold 103. In this example, three pin-shaped movable protrusions 104 are provided, but the number, dimensions, and shape of the movable protrusions are changed as appropriate. There are also mold devices having one, two, or four or more movable protrusions.

[0018] Inside the movable mold 103, the movable protrusion 104 can move forward and backward with respect to the internal space Si of the mold device 101, and is provided so as to protrude into the internal space Si when it moves forward toward the fixed mold 102 side (the right side in FIG. 3). On the other hand, when the movable protrusion 104 moves backward toward the movable platen 32b side (the left side in FIG. 3) to which the movable mold 103 is attached, the tip of the movable protrusion 104 is positioned deeper toward the movable platen 32b side than the internal space Si, as shown in FIG. 3. The movable mold 103 has, on the rear side of the movable protrusion 104, two or other appropriate number of protrusion plates 105a in which the three movable protrusions 104 are connected and overlap each other, and a rod-shaped or other rod abutting member 105b fixed or detachably provided in an upright state on the back surface of the protrusion plates 105a. A protruding rod 42 (to be described later) of the protruding drive device 41 comes into contact with the rod abutment member 105b, and the protruding plate 105a moves forward and backward together with the movable protruding portion 104.

[0019] The illustrated protrusion drive device 41 includes a protrusion rod 42 that extends inside the movable platen 32b and abuts against the rod abutment member 105b of the movable mold 103 to move the movable protrusion 104 forward and backward, and a protrusion drive source 43 that includes a protrusion motor and a motion conversion mechanism such as a ball screw that moves the protrusion rod 42. The protrusion drive device 41 brings about the above-mentioned forward and backward displacement of the movable protrusion 104.

[0020] The movable protrusion 104 and the ejection drive device 41 are mainly used when removing a molded product formed by solidifying the molding material injected from the injection device 11 into the internal space Si of the mold device 101. When removing a molded product from the mold device 101, the mold device 101 is placed in the mold open state shown in Fig. 3, and the ejection drive device 41 causes the movable protrusion 104 to protrude into the internal space Si and displace it forward, and the movable protrusion 104 pushes the molded product out of the mold device 101. The movable protrusion 104 is sometimes called an ejector pin, and the ejection drive device 41 is sometimes called an ejector device.

[0021] (Control device and control method) 2, the control device used in the injection molding machine 1 has at least a control unit that controls the operation of the protrusion drive device 41. The control unit can be dedicated to the protrusion drive device 41, but in many cases, it can control the operation of not only the protrusion drive device 41 but also the injection unit 11, the moving unit 21, the mold clamping unit 31, and other units of the injection molding machine 1. The control unit can be connected to protrusion drive sources such as the protrusion motor of the protrusion drive device 41 of the injection molding machine 1, as well as various other drive sources such as the metering motor, the injection motor, and the mold clamping motor, and various sensors for temperature, rotation speed, etc.

[0022] The control device may further have an input unit used by a user of the injection molding machine 1 to input information, and / or a display unit used to convey information to the user, as in the illustrated embodiment. The input unit and / or the display unit are each connected to the control unit. In a control device having an input unit and a display unit, at least a part of them may be a touch panel. The control device may include a storage unit connected to the control unit for storing information or data. The injection molding machine 1 may be equipped with such a control device.

[0023] In the above-described ejection drive device 41 and mold device 101, if the user does not set the injection molding operation correctly, when the mold device 101 is in a mold clamping state, the movable ejection part 104 may be driven by the ejection drive device 41 and may eject significantly into the internal space Si of the mold device 101. In this case, the tip of the movable ejection part 104 displaced forward toward the fixed mold 102 may collide with the inner surface of the mold device 101, more specifically, with the inner surface that defines the internal space Si of the fixed mold 102, and the mold device 101 may be damaged at the tip or the like.

[0024] To address this, the control device of this embodiment controls the protrusion drive device 41 by the control unit so that the protrusion amount of the movable protrusion 104 of the mold device 101 into the internal space Si is limited based on a predetermined allowable set value. The allowable set value may be, for example, the protrusion amount of the movable protrusion 104 when the tip of the movable protrusion 104 contacts the inner surface of the fixed mold 102, and is set in advance before the injection molding operation is performed. In this case, the control device can control the protrusion drive device 41 so that the protrusion amount of the movable protrusion 104 into the internal space Si does not exceed the allowable set value.

[0025] By controlling in this manner, collision of the movable protrusion 104 with the inner surface of the mold device 101 when the mold device 101 is in a clamped state is avoided, thereby effectively suppressing damage to the mold device 101.

[0026] The illustrated mold apparatus 101 is configured so that the mold clamping device 31 can clamp and compress the molding material between a fixed mold 102 and a movable mold 103 .

[0027] More specifically, in this example mold apparatus 101, the movable mold 103 is provided with, in order from the movable platen 32b side toward the fixed mold 102 side, a movable side mounting plate 106 attached to the movable platen 32b, a spacer block 107 that defines a space Se on the inside in which the aforementioned protruding plate 105a is disposed, a receiving plate 108 provided with an elastic member 108a, and a movable side mold plate 109 that faces the fixed mold 102.

[0028] The movable side mold plate 109 of the movable mold 103 is fixedly attached to the surface of the receiving plate 108 facing the fixed mold 102, and is divided into a plurality of members including a material pressing member 109a which presses the molding material by clamping compression, and a pressure member 109b which is supported by the receiving plate 108 via an elastic member 108a and is pressed against the fixed mold 102 when the clamping force acts. As shown in Fig. 3, two material pressing members 109a and three pressure members 109b each having a block shape or the like are alternately arranged in a direction (vertical direction in Fig. 3) perpendicular to the direction in which the movable platen 32b approaches the fixed platen 32a (horizontal direction in Fig. 3, also called the "movable platen moving direction").

[0029] The receiving plate 108 and the three material pressing members 109a and pressure members 109b located on the inside in the direction perpendicular to the moving direction of the movable platen are each formed with a through hole extending from the space Se of the protruding plate 105a to the internal space Si, and each of the multiple movable protruding parts 104 described above is inserted and positioned inside each of these through holes.

[0030] The elastic member 108a provided on the receiving plate 108 may be a spring member such as a coil spring that resists the clamping force acting in the moving direction of the movable platen, or may be a cylinder (not shown) that moves the pressure member 109b in the same direction.

[0031] The illustrated fixed mold 102 includes a fixed-side mounting plate 110 attached to a fixed platen 32a, and a fixed-side mold plate 111 provided on the surface of the fixed-side mounting plate 110 on the movable mold 103 side. A sprue bushing 112 is provided in approximately the center region of the fixed-side mounting plate 110 and the fixed-side mold plate 111. A sprue 112a is formed on the inner side of the sprue bushing 112 to guide the molding material Mm injected from the injection device 11 to the internal space Si.

[0032] The mold device 101 may be provided with a gap measuring device 121 used to grasp the gap between the material pressing member 109a and the fixed-side mold plate 111 in the moving direction of the movable platen. Here, the gap measuring device 121 includes a non-contact type displacement sensor 122 attached around the backing plate 108, and a target 123 attached to a position facing the displacement sensor 122 around the movable-side mold plate 109. However, the mounting positions of the displacement sensor and the target may be interchanged, and one of them may be attached to the spacer block 107 or the like instead of the backing plate 108, and the other may be attached to the fixed-side mold plate 111 or the like instead of the movable-side mold plate 109. A gap measuring device including a contact type displacement sensor may also be used.

[0033] When the above-described mold device 101 is attached to the injection molding machine 1, the control unit of the control device can execute clamping compression of the molding material Mm, for example, as described below.

[0034] First, in the mold apparatus 101 in the mold open state shown in Fig. 3, the movable mold 103 is displaced toward the fixed mold 102 by using the mold clamping device 31, and the mold apparatus 101 is brought into the mold closed state as shown in Fig. 4. At this time, the pressure member 109b of the movable mold 103 contacts the fixed side mold plate 111 of the fixed mold 102, but almost no mold clamping force is applied to the mold apparatus 101, and the elastic member 108a between the pressure member 109b and the receiving plate 108 is not substantially compressed.

[0035] 5, the mold clamping device 31 moves the movable mold 103 closer to the fixed mold 102, compressing the elastic member 108a and pressing the pressure member 109b against the fixed mold plate 111. As a result, a cavity is defined in the internal space Si of the mold device 101. Here, the restoring force of the compressed elastic member 108a presses the pressure member 109b against the fixed mold plate 111 with a predetermined clamping force. As a result, the generation of burrs in a molded product that is molded after the cavity is filled with the molding material Mm between the pressure member 109b and the fixed mold plate 111 as described below is suppressed.

[0036] Thereafter, the molding material Mm accumulated at the tip of the cylinder 12 of the injection device 11 is injected from the nozzle 12b. As shown in FIG. 6, the molding material Mm injected from the injection device 11 reaches the internal space Si of the mold device 101 through the sprue 112a inside the sprue bushing 112, and is filled in the internal space Si. In this example, among the pressure members 109b supported by the elastic member 108a of the movable side mold plate 109 of the movable mold 103, the central pressure member 109b facing the sprue 112a is formed in a shape in which its facing surface is recessed toward the movable platen 32b side from the parting line, which is the boundary between the other pressure members 109b and the fixed side mold plate 111. In the internal space Si, a void between the central pressure member 109b and the fixed side mold plate 111 functions as a runner. Between the central pressure member 109b and the adjacent material pressing members 109a on both sides thereof, gates 109c are formed for allowing the molding material Mm to flow into the cavity of the internal space Si on the material pressing member 109a side (see FIG. 5).

[0037] After the molding material Mm is filled to a certain extent in the internal space Si of the mold device 101, as shown in FIG. 7, the mold clamping compression is performed by further compressing the elastic member 108a in the mold clamping device 31 and displacing the movable mold 103 closer to the fixed mold 102, so that the molding material Mm in the internal space Si is compressed between the fixed mold 102 and the movable mold 103. When the mold clamping compression is performed, even when a relatively thin molded product is molded, the molding material Mm is sufficiently distributed throughout the entire cavity of the internal space Si, so that molding defects such as sink marks can be effectively prevented. In the mold clamping compression, the distance between the material pressing member 109a and the fixed side mold plate 111 and the compression amount of the elastic member 108a can be adjusted based on the measurement value by the distance measuring device 121 described above.

[0038] Furthermore, the control unit can execute protrusion compression, in which the molding material Mm is compressed by the movable protrusion 104 using the protrusion drive device 41, in addition to or without executing the mold clamping compression.

[0039] When performing both mold clamping compression and ejection compression, before filling the internal space Si of the mold device 101 with the molding material Mm, the movable ejection portion 104 of the mold device 101 is displaced backward by the ejection drive device 41 in advance, as shown in FIG. 5, so that the tip of the movable ejection portion 104 is positioned at a position within the through hole that is deeper than the internal space Si.

[0040] In this state, as shown in Fig. 6, when the molding material Mm is injected from the injection unit 11 and filled into the internal space of the mold device 101, the molding material Mm also fills the gap up to the tip of the through hole into which the movable protrusion 104 is inserted. Next, as described above, mold clamping compression shown in Fig. 7 is performed.

[0041] During or after mold clamping compression, the movable protrusion 104 is driven by the protrusion drive device 41 as protrusion compression, and the movable protrusion 104 is displaced forward, for example, to a position just before the tip of the movable protrusion 104 protrudes into the internal space Si, as shown in Fig. 8. As a result, the molding material Mm that has entered the through hole into which the movable protrusion 104 is inserted is pushed out into the internal space Si by the movable protrusion 104 that is displaced forward, and the molding material Mm in the internal space Si is compressed.

[0042] After that, the molding material Mm is cooled and hardened in the internal space Si to form a molded product. After the molded product is formed in the internal space Si, the control unit, although not shown in the figure, can set the mold device 101 to a mold open state, and cause the protrusion drive device 41 to forwardly displace the movable protrusion 104 to protrude into the internal space Si, and execute removal of the molded product from the internal space Si.

[0043] When performing the above-mentioned mold clamping compression and ejection compression, if the user erroneously sets the operation of the ejection drive device 41, the problem of damage to the mold device 101 may become apparent. That is, before or during the mold clamping compression, when the movable protrusion 104 protrudes significantly into the internal space Si and its tip hits the inner surface of the fixed mold 102, a large mold clamping force is applied to the movable protrusion 104 during the mold clamping compression thereafter. This increases the risk of damage to the mold device 101, such as the movable protrusion 104 breaking. Therefore, this embodiment is particularly advantageous when performing the mold clamping compression and ejection compression with the control unit of the control device, since it can reduce the above-mentioned risk of damage to the mold device 101.

[0044] In order to effectively reduce such a risk of breakage, it is preferable that the control unit prohibits the user from performing the above-mentioned protruding compression when the allowable set value used to limit the protruding amount of the movable protruding portion 104 has not been set. For example, when the allowable set value has not been set, the control unit can prevent the user from selecting the execution of protruding compression through the input unit, or can prevent the start of the injection molding operation including the protruding compression even if the user selects the execution. In addition, the control unit may make the user aware that the allowable set value has not been set by displaying on the display unit, issuing an alarm, or the like.

[0045] When performing protrusion compression, the user can input to the input unit and set one or more stages of protrusion amount when the protrusion drive device 41 displaces the movable protrusion 104 forward during protrusion compression. As an example, Fig. 9 shows a display portion 201 related to the protrusion amount of the movable protrusion 104 from the setting screen that the control unit can display on the display unit. In this example, four stages of protrusion amount from 1st to 4th of the movable protrusion 104 can be set when performing protrusion compression.

[0046] Here, when the user intends to input, from the input unit, a protrusion amount limited based on the allowable set value as the protrusion amount of at least one stage of the movable protrusion 104 from 1st to 4th, for example, a protrusion amount exceeding the allowable set value, the control unit preferably prohibits the execution of protrusion compression. The control unit may also prohibit the user from inputting, from the input unit, a protrusion amount limited based on the allowable set value. This is because if the operation of the protrusion drive device 41, such as protrusion compression, is executed with such a protrusion amount, the risk of damage to the mold device 101 increases. If necessary, for example, the display unit is used to give the user a suggestion that the execution of protrusion compression is prohibited or a suggestion that the input of a protrusion amount limited by the allowable set value is prohibited.

[0047] It is preferable that the preset allowable setting value is displayed on the display unit, as shown as "limit position" in Fig. 9. This allows the user to easily recognize that the allowable setting value has been set, that protruding compression can be executed with the set value, and that the allowable setting value is the upper limit value of the protrusion amount for each stage that can be input.

[0048] The allowable set value can be set by a user by determining and inputting it from the input unit. In this case, the protrusion drive device 41 can be controlled based on the allowable set value set by the user.

[0049] In addition to or instead of allowing the user to input the allowable setting value, it is preferable to allow the user to input mold information regarding the mold device into the input section, and the control section determines the allowable setting value from the mold information input by the user.

[0050] This mold information may include information on the dimensions of the mold device 101. Specific mold information may include, for example, a separation distance D1 between the inner surface of the fixed mold 102 and the inner surface of the movable mold at the protruding position of the movable protruding portion 104 when the movable mold 103 is pressed most against the fixed mold 102 in the moving direction of the movable platen, as shown in Fig. 10. The separation distance D1 is the maximum protruding amount of the movable protruding portion 104 that can protrude into the internal space Si in the mold clamping state, and the control unit may set this as an allowable setting value.

[0051] The mold information may include a distance D2 between the rod abutment member 105b of the mold device 101 and the tip of the protrusion rod 42 when the protrusion rod 42 of the protrusion drive device 41 is moved to the most rearward position in the moving direction of the movable platen, as shown in Fig. 11. The sum of the distances D1 and D2 is the allowable setting value of the stroke amount of the protrusion rod 42, and the control unit may control the protrusion drive device 41 based on such allowable setting value of the stroke amount. Note that the "limit position" in Fig. 9 described above is set to the allowable setting value of the stroke amount of the protrusion rod 42 (the stroke amount from the most rearward position of the tip of the protrusion rod 42 to the most forward position allowed).

[0052] Furthermore, in order to determine the allowable set value for the mold device 101 attached to the injection molding machine 1, the control unit can, for example, with the mold device 101 in a clamped state, cause the movable protrusion 104 to be displaced forward by the protrusion drive unit 41 so as to protrude into the internal space Si. When the movable protrusion 104 comes into contact with the inner surface of the mold device 101 and stops as a result of this forward displacement, the control unit can determine the allowable set value from the forward stop position of the movable protrusion 104.

[0053] Here, since the movable protrusion 104 is displaced forward for the purpose of determining the allowable set value, there is no need to fill the internal space Si of the mold device 101 with molding material. When the mold device 101 is replaced with a different one from before, the control unit can execute determination of the allowable set value by the forward displacement of the movable protrusion 104 prior to execution of the injection molding operation. Note that such forward displacement of the movable protrusion 104 is desirably driven by the protrusion drive device 41 with a relatively low torque so as not to damage or break the mold device 101.

[0054] (mold clamping device) The mold clamping device 31 opens and closes the mold device 101 by displacing the movable mold 103 toward or away from the fixed mold 102 of the mold device 101, thereby putting the mold device 101 into a mold clamped state, a mold closed state, or a mold open state. The mold clamping device 31 includes a platen 32 including a fixed platen 32a and a movable platen 32b, and a platen operating mechanism 33 that operates the platen 32.

[0055] Of the platens 32, the fixed platen 32a is fixedly attached to the base frame 2. On the other hand, the movable platen 32b is disposed on a guide member 32d laid on the base frame 2, and can slide in a direction away from and toward the fixed platen 32a. The mold clamping device 31 is provided with one or more tie bars 32c that extend from the fixed platen 32a toward a rear platen 34 (described later) and connect the fixed platen 32a and the rear platen 34. In this example, the movable platen 32b is guided by the tie bars 32c in its approach and separation displacement with respect to the fixed platen 32a, but it does not have to be guided by the tie bars 32c.

[0056] The platen operating mechanism 33 includes a rear platen 34 arranged on the base frame 2, a mold clamping motor 35 provided on the rear platen 34, a motion conversion mechanism 36 that converts the rotational motion of the mold clamping motor 35 into linear motion in the direction of movement of the movable platen, and a toggle mechanism 37 that amplifies the force transmitted to the motion conversion mechanism 36 and transmits it to the movable platen 32b.

[0057] Among these, the motion conversion mechanism 36 can be various mechanisms capable of converting rotational motion into linear motion, but in this example, it is configured to include a screw shaft 36a that is rotationally driven by the mold clamping motor 35, and a nut 36b that is screwed onto the screw shaft 36a. The motion conversion mechanism 36 can also be a ball screw.

[0058] The toggle mechanism 37 that increases the transmission force from the motion conversion mechanism 36 is formed by connecting a plurality of links 37a to 37c that connect the rear platen 34 and the nut 36b to the movable platen 32b via joints in a swingable manner. The number and shapes of the links and joints can be changed as appropriate, but as shown in FIG. 1, a pair of link groups consisting of links 37a to 37c located above and below the crosshead 37d are connected to the crosshead 37d, which is connected to the nut 36b and extends in the vertical direction, and are swingably connected to the crosshead 37d.

[0059] In addition to the above-mentioned mold clamping motor 35, a mold thickness adjustment motor 38 can also be provided on the rear platen 34. This mold thickness adjustment motor 38 functions to adjust the interval between the fixed platen 32a and the rear platen 34 movably mounted on the base frame 2 by applying a rotational driving force to a screw shaft and a nut connected to an extension of each tie bar 32c of the platen 32 described above. This makes it possible to adjust the mold thickness so that a desired mold clamping force can be applied to the mold device 101 even when the mold device 101 is replaced or the thickness of the mold device 101 is changed due to a temperature change. Although not shown in the figure, the mold thickness can be adjusted even if the fixed platen side is made movable on the base frame 2 and the rear platen side is fixed.

[0060] The illustrated mold clamping unit 31 is of a horizontal type in which the moving direction of the movable platen 32b is parallel to the horizontal direction, but it may also be of a vertical type in which the moving direction is vertical.

[0061] (injection device) The injection device 11 mainly includes a cylinder 12 having a cylindrical shape or the like extending toward the mold device 101, a screw 13 arranged inside the cylinder 12 with its central axis parallel to the cylinder 12 and with flights spirally provided around the periphery, a heater 14 having a band shape or the like arranged around the outer periphery of the cylinder 12, and a motor box 15 arranged behind the cylinder 12 and the screw 13. Although not shown in the figure, the motor box 15 includes a metering motor that rotates the screw 13 around the central axis to accumulate a predetermined amount of molding material at the tip of the cylinder 12, an injection motor that moves the screw 13 forward and backward in each direction, toward and away from the mold device 101, and a pressure detection sensor that detects the pressure that the screw 13 receives from the molding material, etc.

[0062] In this embodiment, the direction approaching the fixed platen 32a of the mold clamping unit 31 to which the fixed mold 102 of the mold apparatus 101 is attached is defined as the front side, and the direction moving away from the fixed platen 32a is defined as the rear side. Looking at the injection unit 11 located to the right of the fixed platen 32a in FIG. 1, the left direction approaching the fixed platen 32a is the front side, and the right direction moving away from the fixed platen 32a is the rear side.

[0063] The cylinder 12 is provided with a supply port 12a, to which a hopper for feeding molding material into the cylinder 12 can be attached, in front of the motor box 15 on the rear side. A nozzle 12b, the cross-sectional area of ​​which decreases on the front side, is provided at the tip of the cylinder 12 close to the mold device 101. A water-cooled cylinder 12c for cooling with water or the like can be provided near the supply port 12a.

[0064] The heater 14 disposed around the cylinder 12 including the nozzle 12b may be divided into a plurality of sections in the cylinder axial direction as shown in the figure, for example, so that the inside of the cylinder 12 inside each heater section can be heated at different temperatures. Each heater section may be provided with a temperature detector.

[0065] Although not shown, a backflow prevention ring may be placed around the tip of the screw 13, which is formed by partially reducing the outer diameter, to prevent the molding material that has been sent forward by moving forward and backward together with the screw 13 from flowing backward to the rear. This backflow prevention ring displaces back and forth relative to the screw 13 in response to the pressure it receives from molding material located forward or backward from it, thereby allowing only the flow of molding material from the rear to the front.

[0066] According to the injection device 11 having such a configuration, the molding material fed into the inside of the cylinder 12 from the supply port 12a is heated by the heater 14 on the outer periphery of the cylinder 12 in the metering process, and is melted by the rotation of the screw 13 driven by the metering motor while being sent forward inside the cylinder 12 and accumulated at the tip of the cylinder 12. At this time, the screw 13 is displaced backward by the injection motor, and a space is formed at the tip of the cylinder 12 in which the molding material is accumulated.

[0067] Then, in the filling step, the screw 13 is displaced forward, so that the molding material at the tip of the cylinder 12 is injected toward the mold device 101 through the nozzle 12b. Furthermore, in the subsequent pressure holding step, pressure is applied to the molding material filled in the cavity of the mold device 101 through the molding material remaining at the tip of the cylinder 12. At this time, it is possible to replenish the molding material that has become insufficient in the cavity of the mold device 101 due to cooling and shrinkage of the molding material.

[0068] Although this injection molding machine 1 is an in-line screw type, it is also possible to make it a pre-plasticization type injection molding machine in which the plasticizing cylinder and plasticizing screw are structurally and functionally separated from the injection cylinder and injection plunger.

[0069] (Mobile device) The moving device 21 is provided, for example, below the motor box 15 of the injection device 11, and is an advance / retract drive mechanism for moving the injection device 11 forward and backward relative to the fixed platen 32a. Various mechanisms can be adopted as the forward and backward drive mechanism that constitutes the moving device 21, but the moving device 21 shown in the figure is composed of a hydraulic pump 22 or the like, a pump operation motor 23, which is electric or the like, that operates the hydraulic pump 22, and a double-acting hydraulic cylinder 24 to which hydraulic fluid is supplied from the hydraulic pump 22 and which performs an extrusion and retraction movement on a piston rod, the tip of which is fixed to a fixed platen 32a.

[0070] The moving device 21 further includes a slide base 25 to which the above-mentioned hydraulic pump 22, pump actuation motor 23, and hydraulic cylinder 24 are attached, and a guide 26 that is laid on the base frame 2 to guide the linear motion of the slide base 25. Thereby, forward and backward displacement of the injection device 11 placed on the upper part of the slide base 25 is realized.

[0071] The moving device 21 makes it possible to move the injection device 11 away from the mold device 101, or to move the injection device 11 closer to the mold device 101 and press the nozzle 12b of the cylinder 12 of the injection device 11 against the mold device 101 with a predetermined pressure, thereby performing a so-called nozzle touch.

[0072] (Injection molding operation) The control unit can execute the following injection molding operations to produce a molded product.

[0073] With a predetermined amount of molding material having already been measured and placed inside the injection unit 11 during the latter half of the previous molding, the mold closing process is performed using the mold clamping device 31 to place the mold device 101 in a mold closed state, as well as a pressure increase process and mold clamping process in which the movable mold 103 is pressed against the fixed mold 102 until a predetermined mold clamping force is applied.

[0074] Next, the screw 13 is advanced to inject the molding material into the mold device 101, and a filling process is performed in which the molding material is filled into the cavity in the mold device 101, and a pressure holding process is performed in which the screw 13 is advanced further to hold the molding material inside the tip of the injection device 11 at a predetermined pressure. At this time, the above-mentioned mold clamping compression and / or ejection compression may be performed.

[0075] Then, a cooling process is performed in which the molding material filled in the cavity of the mold device 101 is cooled and solidified to obtain a molded product. At this time, a measuring process is performed in which the molding material separately charged into the injection device 11 is melted while being sent toward the tip of the injection device 11 by the rotation of the screw 13 under heating by the heater 14, and a predetermined amount of the molding material is placed at the tip.

[0076] Furthermore, after that, the mold clamping device 31 is operated to perform a depressurization process to reduce the clamping force on the mold device 101, and then the mold opening process to open the mold device 101, and then the movable protrusion 104 is moved by the protrusion drive device 41 to perform an extraction process to remove the molded product from the mold device 101. [Explanation of symbols]

[0077] 1 injection molding machine 2 Base frame 11 Injection device 12 cylinders 12a Supply port 12b Nozzle 12c water-cooled cylinder 13 Screw 14 Heater 15 Motor box 21 Mobile Devices 22 Hydraulic Pump 23 Pump operating motor 24 Hydraulic Cylinder 25 Slide Base 26 Guide 31 Mold clamping device 32 Platen 32a Fixed Platen 32b Movable platen 32c tie bar 32d Guide member 33 Platen operating mechanism 34 Rear platen 35 Clamping motor 36 Motion conversion mechanism 36a Screw shaft 36b Nut 37 Toggle Mechanism 37a~37c Link 37d Crosshead 38 Die thickness adjustment motor 41 Ejection drive unit 42 Protruding rod 43 Protruding drive source 101 Mold equipment 102 Fixed mold 103 Movable mold 104 Movable protrusion 105a Projecting plate 105b Rod abutment member 106 Movable side mounting plate 107 Spacer Block 108 Support plate 108a Elastic member 109 Movable side template 109a Material pressing member 109b Pressure member Gate 109c 110 Fixed side mounting plate 111 Fixed side template 112 Sprue bush 112a sprue 121 Distance Measuring Instrument 122 Displacement Sensor 123 Target 201 Display part of the display D1, D2 separation distance Mm molding material Se Space Si internal space

Claims

1. A control device used in an injection molding machine, the control device having a control unit, a mold assembly attached to the injection molding machine has a movable protruding portion which is movable back and forth relative to an internal space of the mold assembly and protrudes into the internal space by forward displacement; the injection molding machine includes an ejection drive device that drives the movable ejection portion of the mold device; A control device that controls the protrusion drive device so that, when the mold device is in a clamped state, the amount of protrusion of the movable protrusion of the mold device into the internal space is limited based on an allowable set value so that the movable protrusion does not contact the inner surface of the mold device.

2. The control device according to claim 1 , further comprising an input section for allowing a user to input information.

3. The control device according to claim 2 , wherein a user can input the permissible setting value into the input section.

4. A user can input mold information related to a mold device into the input unit, The control device according to claim 2 or 3, wherein the control unit determines the permissible set value based on the mold information input by a user.

5. 5. The control device according to claim 2, wherein the control unit prohibits a user from inputting, into the input unit, the amount of protrusion that is limited based on the allowable set value.

6. The control device according to any one of claims 1 to 3, wherein the control unit displaces the movable protrusion forward using a protrusion drive device to protrude into the internal space, and determines the allowable setting value from the forward stop position of the movable protrusion.

7. The control device has a display unit used to convey information to a user, The control device according to any one of claims 1 to 6, wherein the control unit causes the display unit to display the permissible set value.

8. The mold device has a fixed mold and a movable mold, the injection molding machine is provided with a mold clamping device that opens and closes the mold device by moving a movable mold toward and away from a fixed mold of the mold device, The control device according to any one of claims 1 to 7, wherein the control unit, after filling the internal space of the mold device with molding material while the mold device is closed by the mold clamping device, causes the mold clamping device to further displace the movable mold closer to the fixed mold, thereby performing mold clamping compression, compressing the molding material in the internal space between the fixed mold and the movable mold.

9. A control device for use in an injection molding machine, the control device having a control unit, a mold assembly attached to the injection molding machine has a movable protruding portion which is movable back and forth relative to an internal space of the mold assembly and protrudes into the internal space by forward displacement; the injection molding machine includes an ejection drive device that drives the movable ejection portion of the mold device; The mold device has a fixed mold and a movable mold, the injection molding machine is provided with a mold clamping device that opens and closes the mold device by moving a movable mold toward and away from a fixed mold of the mold device, the control unit fills the internal space of the mold device with a molding material while the mold device is closed by the mold clamping device, and then causes the protrusion drive device to perform a protrusion compression by displacing the movable protrusion forward and compressing the molding material in the internal space with the movable protrusion; A control device that controls a protrusion drive device so that the control unit limits the amount of protrusion of the movable protrusion portion of the mold device into the internal space based on an allowable set value.

10. The control device according to claim 9 , wherein the control unit prohibits execution of the protruding compression when the permissible set value is not set.

11. The control device according to claim 9 or 10, wherein when a user intends to limit the protrusion amount based on the allowable set value, the control unit prohibits execution of the protrusion compression.

12. The control device according to any one of claims 1 to 11, wherein the control unit, after molding a molded product from the molding material filled in the internal space of the mold device, causes the protrusion drive device to forward displace the movable protrusion portion to protrude into the internal space, and then causes the molded product to be removed from the internal space.

13. An injection molding machine comprising the control device according to any one of claims 1 to 12 and the ejection drive device.

14. An injection molding system comprising: the injection molding machine according to claim 13; and a mold device attached to the injection molding machine.

15. 1. A method for controlling an injection molding machine, comprising the steps of: a mold assembly attached to the injection molding machine has a movable protruding portion which is movable back and forth relative to an internal space of the mold assembly and protrudes into the internal space by forward displacement; the injection molding machine includes an ejection drive device that drives the movable ejection portion of the mold device; A control method for an injection molding machine, comprising: controlling an ejection drive device so that, when the mold device is in a clamped state, the amount of ejection of the movable protrusion of the mold device into the internal space is limited based on an allowable set value such that the movable protrusion does not contact the inner surface of the mold device.

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