JP4425436B2 - Molding method of injection molding machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for mounting a mold in an injection molding machine.
[0002]
[Prior art]
An electric injection molding machine to which the present invention is applied will be briefly described with reference to FIG. The electric injection molding machine includes an electric injection device driven by a servo motor. In this electric injection device, the screw is moved forward and backward by converting the rotational motion of the servo motor into a linear motion by means of a ball screw and a nut.
[0003]
In FIG. 6, the rotation of the injection servo motor 51 is transmitted to the ball screw 52. A nut 53 that moves forward and backward by the rotation of the ball screw 52 is fixed to a pressure plate 54. The pressure plate 54 can move along a guide bar 56 (usually a plurality of pressure plates, but only one is shown here) fixed to the base frame 55. The forward and backward movements of the pressure plate 54 are transmitted to the screw 60 via bearings, load cells (both not shown) and the injection shaft 57. The screw 60 is disposed so as to be rotatable in the heating cylinder 61 and movable in the axial direction. The heating cylinder 61 corresponding to the rear part of the screw 60 is provided with a hopper 62 for supplying resin. The injection shaft 57 is transmitted with a rotational movement of a servo motor 63 for rotation for rotating the screw 60 via a connecting member such as a belt or a pulley. That is, the screw 60 is rotated by the rotation of the injection shaft 57 by the rotation servomotor 63.
[0004]
The heating cylinder 61 and the hopper 62 incorporating the screw 60 are called a plasticizing device. This plasticizing device is normally locked to the base frame 55, but is unlocked and can be moved forward and backward in the axial direction of the screw 60 by the motor 58.
[0005]
Next, an electric mold clamping device driven by a servo motor will be described. This electric mold clamping device includes a fixed platen 72 to which a fixed mold 71 is attached, a plurality of tie bars 73, a movable platen 75 to which a movable mold 74 is attached, and two arms that are connected at one end to the movable platen 75. 76, a toggle support 77, a mold clamping servo motor 78, a ball screw 79, and a cross head 80 provided with a ball nut screwed to the ball screw 79.
[0006]
The rotational motion of the servo motor 78 is converted into the linear motion of the cross head 80 via the ball screw 79. The linear movement of the cross head 80 is a forward / backward movement of the movable platen 75 via a toggle mechanism including the cross head 80, toggle levers 81 a and 81 b and an arm 76. When the movable platen 75 moves forward and the movable mold 74 comes into contact with the fixed mold 71 and further moves forward, the tie bar 73 is extended and a mold clamping force is generated. 82 is a motor for ejecting a molded product.
[0007]
Also in the mold clamping device, the toggle support 77 is normally locked to the fixed platen 72 via the tie bar 73. However, the toggle support 77, the toggle mechanism, and the movable mechanism 83 are movable by the mold thickness adjusting motor 83 after the lock is removed. Elements including the platen 75 are movable in the mold opening / closing direction.
[0008]
[Problems to be solved by the invention]
By the way, the mounting operation of the mold in this type of injection molding machine is usually performed by fitting the locating ring hole of the fixed mold 71 with the nozzle insertion hole in the fixed platen 72 of the mold clamping device. A locating ring is a member attached to a fixed mold in order to facilitate centering of the fixed mold. Thereby, the nozzle hole at the tip of the heating cylinder 61 and the core of the sprue bush hole of the fixed mold are aligned so that the molten resin can be molded without leaking near the nozzle in the resin filling and injection process.
[0009]
However, many molds are not provided with a locating ring. In this case, in the work of attaching the mold to the platen, the cores of the sprue bushing hole and the nozzle hole of the fixed mold are not easily aligned, and it takes a considerable time to attach the mold. That is, in the case of a mold without a locating ring in a conventional injection molding machine, the mold is lifted by a crane, and the core is aligned by manual advancement / retraction of the plasticizing device by driving the motor 58 and manual operation of the crane. . However, this operation requires time for visual alignment and is not accurate. For this reason, it takes a very long time to mount the mold.
[0010]
Accordingly, an object of the present invention is to enable easy alignment even with a mold without a locating ring, and to shorten the setup time of a molding operation including a mold mounting operation.
[0011]
[Means for Solving the Problems]
The present invention is a method of attaching a fixed mold and a movable mold to a fixed platen and a movable platen in an injection molding machine, respectively, and lifting the fixed mold and the movable mold in an integrated state. In the state where the distance between the mold mounting surface of the movable platen and the mold mounting surface of the movable platen is larger than the combined mold thickness of the fixed mold and the movable mold, The position of the fixed mold in the lifted state is adjusted so that the center is substantially the center of the hole for inserting the resin filling nozzle in the fixed platen, and between the fixed platen and the mold mounting surface of the movable platen. distance, in a state in which was set to be slightly larger than the die thickness, fixed molding which move the entire plasticizing device to a mold clamping apparatus, there the resin filling nozzle into the lifting state Nozzle touch the center of the sprue bush hole of the stationary mold in the lifting state against the sprue bush hole to adjust the position of the fixed die which is in the lifting state so as to follow the center of the resin filling nozzles Next, the nozzle touch centering mode is turned on, so that the current nozzle touch pressure is maintained, or the pressure is lower than the nozzle touch pressure, and the fixed platen and the lifting state are in the state. The forward movement of the entire mold clamping device , excluding the stationary mold and the movable mold, and the backward movement of the plasticizing apparatus are automatically performed simultaneously to reduce the distance between the movable platen and the stationary platen, and the sprue the fixed mold is moved to the mold mounting surface of the stationary platen center of the bush hole is in the state following the center of the resin filling nozzle Luo exit nozzle touch centering mode, the resin filling nozzle hole and the fixed mold fixed mold in the the lifting state with wick suits the sprue bushing bore of each said stationary platen and a movable mold, characterized in that so as to release the lifting after Installing collected to the movable platen.
[0012]
In the nozzle touch alignment mode, the mold closing operation by the mold clamping device and the retreating operation of the plasticizing device are performed in a state where the current nozzle touch pressure is maintained or a pressure lower than the nozzle touch pressure is maintained. Are automatically performed simultaneously to reduce the distance between the movable platen and the fixed platen, and the fixed mold in the state where the center of the sprue bushing hole is aligned with the center of the nozzle for filling the resin It may be executed in such a manner that the nozzle touch centering mode is terminated when it has moved to the mold mounting surface.
[0013]
Further, in the above mold mounting method, when the nozzle touch centering mode is executed, if the nozzle touch pressure or torque increases or exceeds a specified time, this is detected, and the nozzle is detected. It is desirable to stop the touch alignment mode.
[0014]
Further, the nozzle touch alignment mode is stopped by turning off the nozzle touch alignment mode.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Below, the case where 1st Embodiment of the attachment method of the metal mold | die by this invention is applied to the injection molding machine of FIG. 6 is demonstrated. In this embodiment, the fixed mold 71 and the movable mold 74 are integrated and lifted by a crane (not shown) for attachment. A feature of this embodiment is a centering mode between the sprue bush hole of the fixed mold 71 and the nozzle hole at the tip of the heating cylinder 61. In the following, since the fixed mold 71 and the movable mold 74 are integrated, an integrated object of the fixed mold 71 and the movable mold 74 is referred to as a mold unless it is particularly necessary to distinguish between them. The procedure will be described below in order.
[0016]
Procedure 1) As shown in FIG. 1, when the fixed mold 71 and the movable mold 74 are lifted by a crane, the distance between the fixed platen 72 and the mold mounting surface of the movable platen 75 is the fixed mold. The movable platen 75 is moved so as to be sufficiently larger than the combined thickness of 71 and the movable mold 74. This is performed manually by driving the mold thickness adjusting motor 83.
[0017]
Procedure 2) As shown in FIG. 2, the position of the mold is operated by the crane so that the center of the sprue bushing hole of the fixed mold 71 is substantially the center of the nozzle insertion hole of the fixed platen 72. Of course, there is no need for complete alignment.
[0018]
Step 3) As shown in FIG. 3, the movable platen 75 is moved by driving the mold thickness adjusting motor 83 to move the entire mold clamping device except the fixed platen, and the fixed platen 71 and the movable platen 74 are moved. The distance between the mold mounting surfaces should be slightly larger than the mold thickness.
[0019]
Procedure 4) As shown in FIG. 4, the motor 58 is driven to manually move the entire plasticizing apparatus to the mold clamping apparatus side, and the nozzle is pressed against the sprue bushing hole of the fixed mold 71 to The center of the sprue bushing should be aligned with the center of the nozzle. At that time, the height of the mold is adjusted by operating the crane.
[0020]
According to the above procedure, in particular, it is possible to prevent the center of the sprue bushing hole of the fixed mold 71 from shifting in the direction perpendicular to the drawing with respect to the center of the nozzle.
[0021]
After completing the nozzle touch in steps 2-4 above,
Procedure 5) Turn on the nozzle touch alignment mode. This nozzle touch alignment mode is automatically performed by a control device (not shown) when the operator designates it through keyboard operation, and a control operation is set in advance. When the nozzle touch alignment mode is turned on, the entire mold clamping device excluding the fixed platen is driven by the mold thickness adjusting motor 83 while maintaining the current nozzle touch pressure or a pressure lower than the nozzle touch pressure. The forward movement of the plasticizer and the backward movement of the plasticizer are automatically performed simultaneously. FIG. 5 shows a state where the centering of the fixed mold 71 and the nozzle is completed.
[0022]
Procedure 6) When the fixed mold 71 is moved to the mold mounting surface of the fixed platen 72 in the process of the above-mentioned procedure 5, the nozzle touch alignment mode is ended.
[0023]
As a means for confirming that the fixed mold 71 has moved to the mold mounting surface of the fixed platen 72, an encoder that detects the rotational speed of the servo motor of the mold clamping device or the mold thickness moving device is used. For example, when the mold clamping device and the mold thickness moving device are operated and the fixed mold 71 comes into contact with the fixed platen 72, the device does not operate any more and the encoder value does not change. The time when the encoder value does not change is defined as the time of the movement.
[0024]
By these procedures, the fixed mold 71 and the movable mold 74 are attached to the fixed platen 72 and the movable platen 75 with bolts or the like in a state where the nozzle holes and the sprue bushing holes of the fixed mold 71 are aligned.
[0025]
In step 5, when the pressure exceeds a certain nozzle touch pressure or torque, this is detected and the nozzle touch centering mode is stopped. This may be achieved by providing the nozzle touch limit switch 10 shown in FIG. 5 in the moving unit for moving the plasticizing device, or by providing a torque limiter in the drive circuit of the motor 58.
[0026]
Next, as a second embodiment, the above procedure 5 may be changed to the following procedure 5 ′.
[0027]
Step 5 ′) Turn on the nozzle touch alignment mode. When the nozzle touch alignment mode is turned on, the mold closing operation by the mold clamping device and the reversing operation of the plasticizing device are performed simultaneously while the current nozzle touch pressure is maintained or at a pressure lower than the nozzle touch pressure. Automatically done at Of course, as in the procedure 5, when the nozzle touch pressure or torque in the procedure 5 ′ is increased or exceeded, or when it takes more than a specified time, this is detected and the nozzle touch alignment mode is stopped.
[0028]
In the present invention, the mold clamping device motor, the mold thickness adjusting motor can be handled by a servo motor, and the plasticizing movement motor can be handled by a servo motor injection molding machine. Further, even when a locating ring is provided in the fixed mold, the hole diameter may not match the nozzle hole. Therefore, the present invention can also be applied to such a case.
[0029]
【The invention's effect】
According to the present invention, even when there is no locating ring in the fixed mold, the centering of the sprue bushing hole and the nozzle hole of the fixed mold can be easily performed. Can do. Further, since it is possible to omit the provision of the locate ring in the fixed mold, it is possible to reduce the mold manufacturing cost.
[Brief description of the drawings]
FIG. 1 is a view for explaining procedure 1 of a mold mounting method according to the present invention.
FIG. 2 is a view for explaining procedure 2 of the mold attaching method according to the present invention.
FIG. 3 is a view for explaining a procedure 3 of the mold attaching method according to the present invention.
FIG. 4 is a view for explaining a procedure 4 of the mold attaching method according to the present invention.
FIG. 5 is a view for explaining a procedure 5 of the mold attaching method according to the present invention.
FIG. 6 is a diagram showing a configuration of an electric injection molding machine to which the present invention is applied.
[Explanation of symbols]
51 Servo motor for injection 52 Ball screw 53 Nut 54 Pressure plate 55 Base frame 56 Guide bar 57 Injection shaft 58 Motor 60 Screw 61 Heating cylinder 62 Resin supply hopper 63 Servo motor for rotation 71 Solid mold 72 Fixed platen 73 Tie bar 74 Movable Mold 75 Movable platen 76 Arm 77 Toggle support 78 Mold clamping servo motor 79 Ball screw 80 Cross head 81a, 81b Toggle lever 82 Mold ejector motor 83 Mold thickness adjustment motor

Claims (4)

It is a method of attaching a fixed mold and a movable mold to a fixed platen and a movable platen in an injection molding machine,
Lifting the fixed mold and the movable mold in an integrated state,
In the state where the distance between the fixed platen and the mold mounting surface of the movable platen is larger than the combined mold thickness of the fixed mold and the movable mold, the sprue of the fixed mold Adjusting the position of the fixed mold in the suspended state so that the center of the bush hole is substantially the center of the hole for inserting the resin filling nozzle in the fixed platen;
In a state where the distance between the mold mounting surface of the fixed platen and the movable platen is slightly larger than the mold thickness, the entire plasticizing apparatus is moved to the mold clamping apparatus side, and the resin filling is performed. the center of the sprue bushing bore of the stationary mold in the lifting condition is in the lifting state so as to follow the center of the resin filling nozzle against the use nozzle sprue bushing hole of the stationary mold in the lifting state Adjust the position of the fixed mold to complete the nozzle touch,
Subsequently, by turning on the nozzle touch centering mode, the fixed platen and the fixed mold in the lifted state while maintaining the current nozzle touch pressure or holding the pressure lower than the nozzle touch pressure , The forward movement of the entire mold clamping device excluding the movable mold and the backward movement of the plasticizing device are automatically performed simultaneously to reduce the distance between the movable platen and the fixed platen, and the center of the sprue bushing hole. When the fixed mold in the state of being aligned with the center of the resin filling nozzle moves to the mold mounting surface of the fixed platen, the nozzle touch centering mode is terminated,
The resin filling nozzle hole and the fixed mold fixed mold in the the lifting state with wick suits the sprue bushing bore of said stationary platen and movable mold, respectively, from lifting after Installing collected to the movable platen A mold mounting method for an injection molding machine, wherein the mold is released . It is a method of attaching a fixed mold and a movable mold to a fixed platen and a movable platen in an injection molding machine,
Lifting the fixed mold and the movable mold in an integrated state,
In the state where the distance between the fixed platen and the mold mounting surface of the movable platen is larger than the combined mold thickness of the fixed mold and the movable mold, the sprue of the fixed mold Adjusting the position of the fixed mold in the suspended state so that the center of the bush hole is substantially the center of the hole for inserting the resin filling nozzle in the fixed platen;
In a state where the distance between the mold mounting surface of the fixed platen and the movable platen is slightly larger than the mold thickness, the entire plasticizing apparatus is moved to the mold clamping apparatus side, and the resin filling is performed. the center of the sprue bushing bore of the stationary mold in the lifting condition is in the lifting state so as to follow the center of the resin filling nozzle against the use nozzle sprue bushing hole of the stationary mold in the lifting state Adjust the position of the fixed mold to complete the nozzle touch,
Subsequently, by turning on the nozzle touch alignment mode, the mold closing operation by the mold clamping device and the plasticizing device while maintaining the current nozzle touch pressure or holding the pressure lower than the nozzle touch pressure. The fixed mold in which the center of the sprue bushing hole is aligned with the center of the nozzle for filling the resin, by automatically performing the retreating operation in a simultaneous operation to narrow the distance between the movable platen and the fixed platen. After moving to the mold mounting surface of the fixed platen, the nozzle touch centering mode is terminated,
The resin filling nozzle hole and the fixed mold fixed mold in the the lifting state with wick suits the sprue bushing bore of said stationary platen and movable mold, respectively, from lifting after Installing collected to the movable platen A mold mounting method for an injection molding machine, wherein the mold is released .   3. The mold mounting method according to claim 1, wherein when the nozzle touch centering mode is executed, if the pressure exceeds a certain nozzle touch pressure or torque, or if it takes more than a specified time, this is detected. A method for attaching a mold to an injection molding machine, wherein the nozzle touch alignment mode is stopped.   3. The mold mounting method according to claim 1 or 2, wherein the nozzle touch centering mode is stopped by turning off the nozzle touch centering mode.

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