JPS59215840A - Replacement of mold - Google Patents

Abstract

PURPOSE:To speed up the molding work by accomplishing various checking works for the mold used in the injection molding and the maintenance and inspection works prior to the molding in a molding preparator for preheating of the mold. CONSTITUTION:A heat medium fluid (50 deg.C) adjusted in the temperature is circulated through a passage in a mold to be preheated. Then, current flows through a heater such as hot runner and hot gate to perform a preheating up to 200 deg.C. At this point, the value of the current flowing through a heater circuit is measured with an ammeter to check the circuit for disconnection. In addition, by the operation of a holding changeover switch, two molds are opened and closed with a sliding cylinder to check for the matching thereof. Here, a hydraulic actuator driving test, the operation of a pneumatic acutator circuit and the like are also ascertained. This enables the accomplishing of the ascertaining in the operation for the molds and the maintenance and inspection work prior to the molding during the preheating of the die thereby eliminating decrease in the operating rate of an injection molding machine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for replacing a mold in injection molding, and more specifically, the present invention is aimed at preventing in advance various inconveniences caused by the mold. It is.

At the start of injection molding, the temperature of the mold is the same as room temperature, but as the injection molding operation progresses, the amount of heat flowing in from the molten resin injected into the mold and the amount of heat from the molten resin assembled into the mold increase. The temperature rises to a certain level and becomes stable, where the amount of heat flowing in from the electric heater, the amount of heat flowing out or flowing in from the heat medium, and the amount of heat released from the mold surface are balanced.

Since the molding conditions change from time to time until the temperature of the mold reaches the above-mentioned constant stable temperature, the probability of producing a defective molded product is extremely high.

For this reason, prior to the molding operation by the injection molding machine, the mold attached to the injection molding machine is
The mold is preheated with a temperature-controlled heating medium and preheated to a preset temperature by this molding preparation device, and then assembled into the injection molding machine, so that stable molding can be performed from the start of molding with the injection molding machine. It has become common practice to carry out a preliminary molding operation called "preparation of molding", and in order to systematize this operation, a mold is selected and taken out from the mold storage area, transported by a self-propelled vehicle, etc. to the molding preparation equipment described above, and then this operation is performed. This mold is attached to a molding preparation device and preheated to the above-mentioned constant temperature, the preheated mold is removed from this molding preparation device, carried by a self-propelled vehicle etc. to an injection molding machine, and assembled to start molding operation. After the production of the specified number of molds is completed, the mold is removed from the injection molding machine, transported to the mold storage area using a self-propelled vehicle, and the used mold is stored again in the mold storage area, which is a fully automatic system. being developed.

This system described above is extremely effective in achieving efficient operation of the injection molding machine, and the molding preparation device is an extremely important part of this system.

This conventional molding preparation device only has the function of preheating using a heating medium (oil or water), and has the disadvantage that it cannot perform other molding preparation operations on the mold.

If you want to perform molding preparation work other than preheating, such as wiping off rust preventive, you can only do it after opening the mold with the preheated mold installed in the injection molding machine. Ta.

For this reason, not only does the operating rate of the injection molding machine decrease, but also the time and time for performing this preparatory work are extremely restricted, making it impossible to reduce the number of workers as much as possible.

Furthermore, as automation of the automatic mold exchange system using the above-mentioned molding preparation device progresses, even if there is a slight problem with the mold, a large number of defective products will be produced. Even if the above-mentioned inconveniences are discovered early in molding production, time and power will be wasted after molding preparation work, which will not only reduce the operation rate of the injection molding machine but also cause problems with production planning. It was also going to cause major problems.

The present invention was devised to solve the drawbacks and inconveniences of the conventional examples described above, and the molding preparation work other than the preheating required for the mold can be performed during the preheating work in the molding preparation device for the mold. This is done in parallel with the preheating work.

Hereinafter, the present invention will be explained with reference to the drawings.

The mold exchange method according to the present invention involves selecting and taking out a mold from a mold storage area, attaching the taken-out mold to a molding preparation device, preheating the mold with a heat transfer fluid, and once the preheating is completed. For example, in a mold exchange method in injection molding, in which the mold is removed from a mold preparation device, attached to an injection molding machine, and then molded, the operation of the mold is checked in the mold preparation device during a preheating operation by the mold preparation device. At least one of the work and pre-molding maintenance and inspection work is performed.

The operation confirmation work and pre-molding maintenance inspection work performed using the same molding preparation device during the preheating operation of the mold are as follows. The operations of the mold mechanism and the ejector driven by hydraulic ejectors are checked.In addition, pre-molding maintenance and inspection work includes wiping off the rust preventive agent and cleaning the inner surface of the mold cavity (for porcelain or rust). presence or absence, presence or absence of oil leakage from mechanical parts such as protruding pins on the inner surface of the mold cavity, presence or absence of disconnection of the electric heater and its circuit, presence or absence of a temperature sensor for the heated part by the electric heater and disconnection of its circuit, switch. There are also tasks such as checking for breaks in the circuit.

According to the present invention, both or one of the above-mentioned operation confirmation work and pre-molding maintenance inspection work is performed by a molding preparation device during a period of preheating work for the mold.

A specific example of a molding preparation apparatus configured to carry out the method of the present invention will be explained with reference to the drawings.

The illustrated example of the molding preparation device has a box-shaped frame 20 that houses control equipment for preheating, operation confirmation, and pre-molding maintenance and inspection. A mechanism is provided for assembling and holding both molds 150 and reversing the posture of the held molds.

That is, a fixing plate 3 is reversibly attached to the upper end of the raised part of the fixing bracket 1 fixed to the upper surface of the frame 20 by means of a pin 2 and a clamp 4 for immovably assembling and holding the fixed mold 5. The base end of a reversing cylinder 7 is rotatably connected to the rear end of the fixing bracket 1 by a pin 6, and the tip of the piston rond of the reversing cylinder 7 is rotatably connected to one end of the fixing plate 3 by a pin 8. At the raised upper end of the movable bracket 11, which is connected to form a fixed holding function part and is slidably assembled to the upper surface of the frame 20, opposite to the fixed holding function part,
A movable plate 13 which holds a movable mold 15 immovably by a clamp 14 is rotatably attached by a pin 12, and a piston rond of a reversing cylinder 17 whose base end is rotatably attached to the rear end of the movable bracket 11 by a pin 16. A protruding rod 19'', which is a piston rod of a protruding cylinder 19 whose tip end is rotatably connected to one end of the movable plate 13 with a pin 18 and is fixed to the movable plate 13, is passed through a hole 13'' provided in the movable plate 13. A movable mold holding function portion is constructed by protruding from the front surface of the movable plate 13 and operating the protruding plate of the movable mold 15 assembled to the movable plate 13.

Further, between the fixed holding function part and the movable holding function part, that is, the fixed bracket 1 and the movable bracket 1
A sliding cylinder 10 whose base end is fixed to the fixed bracket 1 and whose tip end of the piston rod is fixed to the movable bracket 11 is installed between the sliding cylinder 10 and the fixed bracket 1.

Inside the frame 20, there are a hydraulic source, a sliding/reversing hydraulic circuit, a hydraulic circuit for testing a hydraulic actuator, a hydraulic protruding circuit, a pneumatic source, a pneumatic circuit for testing a pneumatic actuator, and a heating circuit for heating medium fluid. Pre-molding maintenance and inspection of functional parts such as adjustment circuits, pump circuits, and control circuits that control these, power supply circuits for electric heaters, temperature control circuits, disconnection detection circuits, power supply circuits for switch circuits, and inspection circuits. The front side of the frame 20 serves as a control panel for these circuits.

On the front side of the frame 20, there are a control section A for the sliding/reversing hydraulic circuit and a hydraulic ejection circuit, a control section B for the hydraulic actuator drive test hydraulic circuit, a control section C for the pneumatic actuator drive test pneumatic circuit, and a switch circuit control section A. Inspection circuit control section D1
A control section E for an electric heater power supply circuit, a temperature control circuit, and a disconnection detection circuit, and a control section F for a heating circuit, a temperature control circuit, and a pump circuit for a heating medium fluid are provided.

In the control section A, A1 is a start/stop button for the hydraulic power source circuit, 82 is a hydraulic pressure needle for the hydraulic power source circuit, A3 is a holding type changeover switch for moving the sliding cylinder 10 forward and backward, and 84 is a reversal switch. A holding type changeover switch for moving the cylinder 7.17 forward and backward, A5 is the hydraulic protruding cylinder 19
This is a holding type changeover switch for moving the machine forward or backward.

In the control unit B, B1 is a holding type changeover switch for moving the hydraulic actuator in the mold forward/backward or forward/reverse, and B2 is a hydraulic terminal for connecting hydraulic pressure to the mold. The start/stop button shares the start/stop button A1 of the control section A, and similarly, the hydraulic pressure needle of the hydraulic pressure source circuit shares the hydraulic pressure gauge A2 of the control section A, and furthermore, the hydraulic pressure source circuit itself also shares the same use. There is.

In the control section C, C1 is a stop valve that connects and disconnects the pneumatic pressure source circuit spread throughout the factory and the pneumatic actuator drive test pneumatic circuit described above, and C2 is the The pneumatic pressure needle of the pressure source circuit, C3 is a holding type changeover switch for moving the pneumatic actuator in the mold forward/backward or forward/reverse, and C4 is the pneumatic pressure needle for connecting the pneumatic pressure in the mold. It is a terminal.

The control power of each of the above-mentioned control units A, B, and C is turned on and off by the start/stop button AI, and each holding type switch A3, A4, A5, and B1 is turned off when facing upward, for example. Its switch position is set so that it can be pushed to the right to move forward or rotate forward, and pushed to the left to move backward or reverse.

In the control section, Dl turns on/off the power supply for the switch circuit.
An off button, B2 is an ammeter that measures the current flowing through the inspection circuit, and B3 is a terminal for connecting the switch circuit power source to the mold.

In the control section E, El is an on/off button for the power supply circuit for the electric heater and the control circuit, B2 is an ammeter that measures the current flowing through the power supply circuit for the electric heater, and B3 is a temperature detector in the mold (for example, a thermocouple, etc.). B4 is a terminal that connects the power supply for the electric heater to the mold, and F5
is a terminal that connects the signal from the temperature sensor in the mold to the temperature indicating regulator.

In the control unit F, Fl is a start/stop button for the heating circuit, temperature control circuit, and pump circuit for the heating medium fluid, F2 is a pressure gauge for the pump discharge pressure of the heating medium fluid, F3 is a temperature indicating regulator for the heating medium fluid, F4 is a terminal for connecting a heat transfer fluid to the mold.

As mentioned above, in order to make it easier to understand, each of the control units B, C, D, E, and F has been shown in an embodiment in which terminals are provided for connection with the mold, but these terminals are integrated into one block. If these blocks are attached to the fixed plate 3 and the movable plate 13, and the corresponding blocks are attached to the fixed mold 5 and the movable mold 15, respectively,
By attaching the fixed mold 5 to the fixed plate 3 and the movable mold 15 to the movable plate 13, the molding preparation device and both molds 5.15
Since wiring and piping can be connected between the mold and the mold, the workability of handling the mold in the mold preparation device is improved.

In addition, in the control parts B, C, D, and E, multiple controlled circuits may be provided, or only the terminals may be provided with multiple circuits, and the connection with the control circuit may be switched to inspect multiple locations. good.

In addition, in the figure, G is an air release gun, and this air release gun G
consists of a terminal G1 connected to the air pressure source circuit after the stop valve CI of the control section C, a hose G2, and a gun G3.

Next, the operation of the specific example shown in the drawings will be explained in order from the time when the fixed die 4 is attached to the fixed plate 3 and the movable die 15 is attached to the movable plate 13.

■Turn on the start/stop button F1 and set the temperature of the heat medium fluid (oil, water, etc.) to a preset temperature, e.g. 50°C, using the temperature indicator F3, and then heat the A media fluid is circulated through the channels within the mold to preheat the mold to the appropriate temperature.

■Turn on the on/off button E1 and set the heating temperature of the part to be heated with the temperature indicator E3 to, for example, 200°C to heat the hot runner, real gate, etc. If the heating section is equipped with an electric heater, the heating section is set by supplying controlled power to the electric heater from the temperature regulator E3, which is activated by a signal emitted from a temperature sensor attached to the heating section. Preheat to temperature.

■During the work in the above ■, the electric current was measured by the ammeter E2.
The current value flowing through the circuit is measured and compared with the normal current value determined in advance to determine whether there is a disconnection in the electric heater circuit.

In other words, not only when the current value measured by ammeter E2 is zero, but also when it is lower than the normal value, it is determined that one of the multiple electric heaters or its circuit is disconnected. I can do it.

■Also, if the temperature indication value of the temperature indication controller E3 does not change after power is supplied to the electric heater during the work in (■) above, it can be determined that the temperature sensor or its circuit is disconnected. .

■Turn on the start/stop button AI and operate the holding type changeover switch 83 to open and close both molds using the sliding cylinder 10 and check the state of the molds together.

■If the mold has a hydraulic slide piece, etc., operate the holding type changeover switch B1 and drive it with the hydraulic circuit for the hydraulic actuator drive test during the work in (■) above to check whether it operates without any abnormality. You can.

■If the mold has an ejection mechanism, operate the holding type changeover switch A5 and check that the ejection mechanism operates without any abnormality using the hydraulic ejection circuit and cylinder during the work in step (■) above. You can.

■If there is an air pin, etc., open the stop valve C1 and operate the holding type changeover switch C3 to use the pneumatic circuit for the pneumatic actuator during the work in (■) above.
By driving this air pin, etc., it is possible to check whether it operates without any abnormality.

■If there is a switch for checking the operation of each actuator (limit switch, proximity switch, reed switch, photoelectric switch, etc.), turn on/off button D1 to the ON state and , by supplying power to the switch by a check circuit of the switch circuit, and measuring the value of the current flowing through this check circuit with an ammeter D2, it is possible to check whether this switch is properly emitting a signal. .

For example, if there is a normally-wired limit switch that confirms that the protruding plate has advanced to the forward limit, the current in the inspection circuit is zero unless the protruding plate is at the forward limit, and when it is at the forward limit. A current flows only in this case, and this current becomes a signal.

[Phase] After operating the holding type switching switch 3 and 8 4 to operate the sliding cylinder 10 and moving the movable bracket 11 to open the fixed mold 5 and the movable mold 15, the re-inversion cylinder 7 .17 is activated to invert the fixed plate 3 and movable plate 13, thereby inverting the fixed mold 5 and movable mold 15 to a position with their mold mating surfaces facing upward (see FIG. 2).

■After this [phase] work, wipe off the rust preventive agent on the mating surfaces of both molds and the mold cavity surface, and perform inspection and maintenance work for cloudiness, rust, oil bleed, etc.

Note that the operations in [phase] and (2) may be performed without reversing the postures of both molds.

@Air discharge gun G blows away foreign matter on the mold mating surface and mold cavity surface.

0 The holding mold switching switches 83 and 84 are operated in the opposite direction to the [phase] to reverse and return both molds and to align the molds.

As described above, the mold replacement method according to the present invention performs one or both of various operation check operations and pre-molding maintenance and inspection operations for the mold during the preheating operation of the mold in the mold preparation device. Therefore, the operation confirmation work and the pre-molding maintenance and inspection work for this mold can be carried out with sufficient time.
This can be done more reliably and accurately.

In addition, since the operation confirmation work and pre-molding maintenance and inspection work for the mold are performed in the molding preparation device, they can be carried out without stopping the injection molding operation of the injection molding machine, which allows injection molding There is no reduction in the operating rate of the machine.

Furthermore, if there is a slight defect in the mold, this defect will be discovered during the above-mentioned operations in the mold preparation equipment, thereby preventing the production of a large number of defective molded products, and preventing the molding operation from being carried out. It is possible to prevent a large amount of time and effort from being wasted, and to prevent a reduction in the operation rate of the injection molding machine and a major hindrance to the production plan.

As is clear from the above description, the mold replacement method according to the present invention performs various operation confirmation work and pre-molding maintenance inspection work on a mold used for injection molding using a mold preparation device other than an injection molding machine. Since this is done during the preheating work on the mold, the various operation confirmation work and pre-molding maintenance inspection work described above can be done with sufficient time.
As a result, this operation confirmation work and pre-molding maintenance and inspection work can be performed accurately and reliably, and this work can be performed completely independently of the injection molding operation of the injection molding machine. There is no risk of reducing the operating rate of the mold, and if there is a problem with the mold, it can be known in advance, so there is no need to produce a large number of defective products, and there is no need to waste labor in molding work. It can exhibit many excellent effects such as being able to prevent such problems.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a specific example of a molding preparation apparatus configured to carry out the method of the present invention, and shows an operating state in which a mold installed therein is held in a closed state. FIG. 2 similarly shows an operating state in which the mold is opened and held in an inverted position. Explanation of symbols 1; Fixed bracket, 3; Fixed plate, 5; Fixed type, 7.1
7; Reversing cylinder, 10; Sliding cylinder, 11; Moving bracket, 13; Moving plate, 15; Moving type, A, B, C,
D, E, F, Control Department, Official Manual of Procedures (Voluntary) 1. Display of the case 1982 Patent application No. 092099 2, Name of the invention Mold replacement method 3, Person making the amendment Relationship to the case Patent applicant address 2-24-1 Oshika, Shizuoka City, Shizuoka Prefecture Name Arrow
Saki Kako Co., Ltd. 4, Agent (1) The name of the inventor stated in the above-mentioned application form, ``Yasushi Moritani,'' shall be amended to ``Yasushi Moritani.'' (2nd page 15, 13 of the specification attached to the same application)
From line to line 14, [..., sliding cylinder 10...] means "...
, the inviting/exciting cylinder 10...J. (3) Of the drawings attached to the application, Figure 2 will be amended to the amended drawing attached to the written amendment. 7. List of attached documents (1) One copy of application for correction (2) One or more copies of amended drawings

Claims (1)

[Claims] (1) Select and take out a mold from the mold storage area, attach the taken out mold to a molding preparation device, preheat the mold with a heat transfer fluid, and when the preheating of the mold is completed, A mold replacement method in injection molding in which a mold is removed from a molding preparation device, attached to a molding machine, and then molded, and in the molding preparation device, operation confirmation work and pre-molding maintenance inspection of the mold are performed during preheating operation. A mold exchange method that performs at least one of the operations.