JPH0361521A - Device and method for controlling injection moldable material into cavity of mold - Google Patents

Abstract

PURPOSE: To accurately control a parameter regarding an injection in a mold cavity by regulating a displacing speed of a material moldable in the cavity in response to an apparatus for monitoring at least one of displacing speed and pressures of moldable material in the cavity. CONSTITUTION: A material moldable from an injection chamber 18 is displaced into a mold cavity 14. At least one of a displacing speed of a material moldable from the chamber 18 and a pressure of the material moldable in the cavity is monitored. A displacement of the material moldable from the chamber 18 is controlled in response to a monitoring step to regulate a flow of the material moldable in the cavity 14. Preferably, the displacement is executed from the chamber 18 with the material moldable by a mechanical actuator driven by a motor. The actuator driven by the motor has a motor 32 for driving a power shaft 3 operably coupled to a piston 30 via a worm gear assembly 36 and a piston rod 38.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates generally to injection molding, and more particularly to a method and method for controlling the injection of moldable material from an injection chamber into a mold cavity. Regarding the location.

Prior Art Prior art molding machines typically move wax or other moldable material from a piston and cylinder assembly into a mold cavity until the wax in the mold cavity reaches a predetermined pressure. eject. Once the predetermined pressure is reached, the pressure in the mold cavity is kept substantially constant by holding the piston IN maintaining a predetermined n force.

Some 7L hydraulically operated Kenzan molding machines have wax injection screws 1
- a configuration for presetting the rate at which hydraulic fluid is injected into the hydraulic actuator to preset the rate at which the cylinder is moved forward; However, it is difficult to precisely control the displacement rate of the moldable material during the injection cycle. In addition, it is difficult to adjust or control other injection parameters, such as the acceleration of the material injected during the injection cycle. Without such precision and additional control over injection parameters, increased machine operating efficiency and increased reproducibility of molded article dimensions and shapes are difficult to achieve.

4: This lack of precise control over the parameters at which moldable material is injected into the cavity of a typical prior art machine influences the flow pattern and sequence in which the mold cavity is filled with moldable material. It interfered with my efforts to make a decision. For this reason, when a defect occurs in a molded article, such as a crack in the material or a crack in the ceramic core placed in the mold cavity, efforts are made to identify the cause of the defect and eliminate it. A time-consuming and expensive trial-and-error procedure is required.

Additionally, hydraulically operated injection molding machines suffer from other disadvantages resulting from the use of hydraulic actuators. In particular, hydraulic pumps for pressurizing working fluids are generally extremely noisy, creating a long-term health risk for the machine operator. Additionally, hydraulic pumps generate relatively large amounts of heat, which results in increased cooling loads at the work site where the machine is operated. Furthermore,
Hydraulically operated injection molding machines place stringent space requirements on the facility housing the machine, as the hydraulic system requires space for pumps and pump drives, working fluid reservoirs, and hydraulic actuators. Finally, hydraulically actuated systems generally present a high maintenance burden due to their complexity.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method and apparatus for accurately controlling parameters associated with the injection of moldable material into a mold cavity.

It is another object of the present invention to provide a method and apparatus that increases the efficiency of a molding operation and increases the reproducibility of molded articles molded in a mold cavity.

It is a further object of the present invention to provide a fact-finding method for analyzing the causes of defects that may exist in molded articles and determining why such defects occur and how they can be eliminated. be.

It is another object of the present invention to provide a method and apparatus that eliminates the disadvantages of hydraulic actuators commonly used in prior art injection molding machines.

Additional objects and benefits of the invention are set forth in the following description and include:
In addition, this will be apparent in part from the description, and may also be known by practicing the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the claims.

SUMMARY OF THE INVENTION To achieve the foregoing objects and in accordance with the objects of the invention embodied herein and broadly described, a mold cavity for receiving moldable material is defined. With the die that
A mold cavity for molding an article comprising an injection chamber containing moldable material to be injected into the biddy and a device for conducting the flow of moldable material from the injection chamber to the mold cavity. Machinery provided. The device includes a device for displacing the moldable material from the injection chamber through the conduction device into the mold cavity, and a) a displacement rate of the moldable material conducted into the mold cavity; and a device for monitoring at least one of the moldable material pressures of the moldable material. Finally, a device responsive to the monitoring device is provided for controlling the displacement device to adjust the rate of displacement of the moldable material into the mold cavity.

Preferably, the injection chamber houses a cylinder having a piston reciprocatably disposed therein, and an electric motor for rotatably driving the displacement device's power shaft.

A rotary motion to right wheel motion converter is operably connected to the power shaft and the piston to convert rotary motion of the power shaft to linear motion of the screws.

The monitoring device includes a resolver for sensing rotation of the power shaft, and means for determining the displacement and speed of the moldable material displaced from the injection chamber according to the sensed rotation of the power shaft by the controller. It is further preferable to include.

The controller controls the deformation d during the first part of the injection cycle according to the monitored displacement rate of the formable material and the P! of the formable material. It is further preferred to υ control the displacement device during the second part of the injection cycle in response to the applied 7,E force.

In accordance with the objects of the invention embodied and broadly described herein, a closed mold having an inlet for receiving moldable material from an outlet of an injection chamber is provided. A method is provided. The method comprises: displacing moldable material from an injection chamber into a mold cavity; a) the rate of displacement of the moldable material from the injection chamber; and a) the pressure of the moldable material in the mold cavity. monitoring at least one of the following.

The displacement of the moldable material from the injection chamber is 91 m in response to the monitoring step to adjust the flow of the moldable material into the mold cavity.

The present invention also provides a method of determining the flow pattern in which a mold cavity is filled with moldable material. The physical analysis method includes injecting a first predetermined volume of moldable material into a die cavity, the first predetermined volume being less than the volume of the mold cavity. The partially molded article is removed from the cavity after curing.

A second predetermined jet of moldable material greater than the first predetermined amount is then injected into the mold cavity and removed after curing. Subsequently, more moldable phase a
can be injected into the mold container and removed therefrom. Each of the sequentially molded articles is then analyzed to determine the flow pattern in which the mold cavity is filled during a particular injection cycle. The results of the analysis can be used to determine why defects occur in the molded article and how the defects can be corrected.

Attachment (1), which is incorporated in and constitutes a part of this document, illustrates the preferred embodiments of the invention and the general description given above and the preferred embodiments given below. The detailed description of the embodiments together serve as a detailed description of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the invention will now be described in detail, as illustrated in the accompanying drawings.

As illustrated in FIG. 1, apparatus U, shown generally at 10, includes a die or molding tool 12 defining a mold cavity 14 for receiving moldable material to be molded into a molded article. The molded article can be, for example, a wax pattern that is subsequently used in a lost wax process for casting turbine blades. Apparatus 10 further includes a reservoir 16 containing a supply of moldable material, such as wax. Reservoir 16 communicates with injection chamber 18 through conduit 20 . A control valve 22 is disposed within conduit 20. i, IJ m valve 22 is mold key 1
7 prior to injection into the bitty 14 - the injection chamber 18 with a predetermined amount of moldable material, commonly referred to as sufficient material;
The injection chamber 18 acts to allow moldable material to flow from the reservoir 16 into the injection chamber 18 in order to fill the injection chamber 18. During injection of moldable material from the injection chamber 18 into the mold 4: rubity 14, the control valve 22 is closed to prevent backflow of moldable material from the injection chamber 18 into the reservoir 16.

In the preferred embodiment illustrated in FIG. 1 U, the injection chamber 18 comprises a cylinder having a piston 30 reciprocatably disposed therein so as to be movable relative to the cylinder 18.

The device of the present invention is capable of producing gold from the injection chamber! ';! 2. It includes it for conducting the flow of moldable material to the cavity. As here embodied, the transmission device includes a conduit 24 extending from an outlet 26 of the injection chamber 18 .

At the other end of the conduit 24 is an injection nozzle 25 which can be moved into engagement with the inlet 28 of the molding tool 12 and into a disengaged state. Moldable material is injected into the mold cavity 14 when the injection nozzle is engaged with the inlet 28. Injection nozzle 25 can be moved into engagement with inlet 28 and into separation by a conventional pneumatically or mechanically actuated single cylinder assembly. Alternatively, the conduit 24 can be formed as a movable hollow cylinder with an inlet positioned to coincide with the outlet 26 when the injection nozzle 25 is engaged with the inlet 28.

The apparatus of the present invention includes a device for displacing moldable material from an injection chamber through a conductor and into a mold cavity. As embodied here, the displacement device [yo, power #
A power source (not shown) to rotatably drive the j34.
The electric motor 32 connected to the J!
! ! ! A rotary motion to ll1f linear motion converter device consisting of a worm gear assembly 36 is provided.

The reduction ratio of the worm gear assembly 36 is electric! can be selected to optimize the mechanical load on 132 and to increase the degree of control over the linear motion of piston 30. The displacement device of the present invention is not limited to the worm gear assembly 36; many other mechanisms known to those skilled in the art may be utilized to convert rotational motion of the power shaft 34 into linear motion of the piston 30. I can do it.

According to the invention, an apparatus is provided for monitoring at least one of a) the velocity of the moldable material conducted into the mold cavity; and) the pressure of the moldable material in the mold cavity. Including equipment. As embodied here, the monitoring device includes a resolver 40 for sensing the angular rotation of the power @34.

Resolver 40 is operably coupled to electric motor 32 to sense the position of electric motor 32 and, therefore, the angular rotation of power shaft 34 .

The resolved portion of the resolver 40 corresponds to a predetermined number of motor positions where each 360'' rotation of the power @34 can be separately sensed by the resolver 40, thereby allowing the motor position and the power
The angular rotation of 4 is monitored very precisely. For purposes of describing the preferred embodiment of the present invention, sensing or monitoring angular rotation of power shaft 34 will be understood to include sensing and monitoring the motor position of electric motor 32.

However, the invention is not limited to the disclosed device embodying a monitoring device, and many other suitable alternative devices for sensing angular rotation of power shaft 34 will be known to those skilled in the art.

The rotation of the power shaft 34 is caused by the piston 3 via the piston rod 38.
0 linear motion, the position of the piston 30 within the cylinder constituting the injection chamber 18 is, for example, the position of the motor 32 from a predetermined base line corresponding to the bottom dead center position of the piston 30. It can be determined by counting the number. Similarly, the rate of displacement of the moldable material from the injection chamber 18 is determined by the rate of displacement of the moldable material from the injection chamber 18.
Since the displacement rate of the moldable material from the injection chamber 18 directly corresponds to the linear velocity of
The rotational speed of the worm gear assembly 36 can be monitored by monitoring the rotational speed of the worm gear assembly 36 to know the reduction ratio of the worm gear assembly 36. In this preferred embodiment, electric motor 32 rotates one revolution for each rotation of power shaft 34. Therefore, the resolver 40 monitors the electric power 1132 from the MIIA and the rotational speed of the power shaft 34, and
8 and is further operative to monitor the rotational speed of the electric motor 32 and power shaft 34 and the corresponding linear speed of the piston 30 within the injection chamber 18. be able to.

According to the invention, as embodied herein, the supervision? f4
The apparatus further includes a pressure transducer 42 for monitoring the pressure of the moldable material within the mold cavity 14. In the preferred embodiment of the invention illustrated in FIG.
2 is arranged to sense the pressure of the moldable material conducted from the injection chamber 18 into the mold cavity 14 through the conduit 24 .

As understood by those skilled in the art, the mold cavity 14
Once filled with moldable material, the pressure in conduit 24 equals the pressure in mold cavity 14. Pressure transducer 42 is operable to generate a voltage signal proportional to the pressure of the moldable material in conduit 24 and is further operable to transmit the signal through lead 44 to comparator device 46. can do. Comparison +a 46 generates an electrical signal and transmits the signal through lead 48 to input terminal 49 of feedback servo controller 50. Comparator 46 and feedback servo controller 50
The action of 'C' will be explained in detail below.

According to the invention, the apparatus further includes a device for controlling, responsive to the monitoring device, the displacement device to adjust the rate of displacement of the moldable material into the mold cavity. As embodied here, the device 11111m includes a feedback servo controller 50. Feedback servo controller No. 50, 1lill IXI signal lead wire 54
Output terminal 5 for transmitting to ``C electric 1JIi32 through
Contains 2. Feedback (nervot, +1m) device 50 includes an input f56 for receiving the signal generated by resolver 40 through lead 58. Resolver 40
The signal number generated by corresponds to the detected rotation of the power 0k34. Feedback servo 1. The IJm device 50 detects the detected rotation of the power shaft 34 or the pressure conversion'
The operation of electric motor 32 is controlled according to the pressure monitored by rv 142, or both.

Feedback servo controller 50 can compare the rotational speed of power shaft 34 with the time domain to determine the rotational speed of power shaft 34 and the corresponding linear speed of piston 30. In this way, the feedback servo control till device 50
The iIiIIIm device comprises a device for determining the displacement and velocity of the moldable material displaced from the injection chamber in accordance with the sensed rotation of the power shaft 34. In particular, the end of the moldable material displaced from the injection chamber 18 directly corresponds to the position of the piston 30 relative to its line in the cylinder that constitutes the injection chamber 18 . Similarly, the rate of displacement of moldable material from the cylinders making up injection chamber 18 is directly related to the linear velocity of piston 30 as it moves within injection chamber 18.

Feedback servo MmE50 receives command signals corresponding to specific variable injection parameters set at input terminal F60 by the operator. These firing signals can be input by the operator at the control panel 62 and can be input to the lead I! 1I64. By way of example, and not as a limitation, these parameters include the following: injection capacity, i.e., amount of moldable material injected from injection chamber 18 into mold cavity 14; 24 into the mold cavity 14 and the acceleration of the flow of the moldable material displaced from the injection chamber 18 until a predetermined flow rate is reached and the moldable material in the mold cavity 14. The pattern may include a maximum pressure of the material and a residence time applied to the pattern to cure within the mold cavity 14 prior to ejection. Thus, a device incorporating the teachings of the present invention is capable of controlling a large number of injection parameters during each injection cycle over the course of the injection cycle.

By way of example, and not as IIJ 1iil, the Department of the Invention hereby describes the fblJ controller 5 in the preferred embodiment of the invention.
0 and 1" and utilizes a Gould Bi Model 410 Intelligent Brushless Servo Positioner manufactured by Gould Inc. In a operative embodiment of the present invention constructed in accordance with the present invention, the controller is programmed with a first subroutine that reads commands entered into the 1III control panel 62. converts these set points into corresponding rotational speeds of the electric machine 32, and calculates a preset flow rate of the moldable material, a preset acceleration of the flow rate of the moldable material, and a predetermined injection capacity. The IJIII device can be conceived as comprising two subassemblies. The first subassembly includes the various glues mentioned above.

It has an intelligent microprocessor that is programmed with routines. The second subassembly is Intelligent MicroPro I? ) J-Electric motor 32 and power shaft 34 according to specific commands from the subassembly! It is equipped with a servo positioner that performs i1wJ.

The electrical signal corresponding to the preset command pressure set point entered into the feedback servo controller 50 by the operator is output to the output terminal as an analog voltage signal having a predetermined absolute value corresponding to the preset displacement rate of the formable feed. 66 through lead l1i68 to comparator 46. Comparator device 46 operates to compare the electrical rf signal produced by pressure transducer 42 with the voltage signal produced by feedback servo damper 50. When the two voltage signals are at a maximum, ie, when pressure transducer 42 is producing zero voltage corresponding to zero gauge pressure in conduit 24, the voltage difference is passed through lead 1148 to feedback servo tII.
The signal is transmitted to the input terminal 49 of the JIl device 50.

The maximum voltage difference signal is the feedback servo controller 50
The motor 32 and power shaft 34 are operated at a rotational speed corresponding to a preset maximum displacement rate of the formable material.

As the pressure sensed by pressure transducer 42 increases, the difference between the voltage output of pressure transducer 42 and the voltage output signal from output terminal 68 of controller 50 decreases as determined by comparator 46. do.

Therefore, the output voltage signal from comparator 46 decreases. Feedback servo control 550 responds to the reduced voltage output signal of comparator 'a46 to control motor 32 and power@34.
, thereby reducing the rate of displacement of the moldable material from the injection chamber 18 . lastly,
Once a predetermined command pressure of the material capable of forming 1 iJ is achieved,
The voltage output of the pressure transducer 42 is controlled by feedback servo.
Compatible with the output voltage command signal of the J unit 50 and the comparator 46
The voltage difference generated by becomes zero. At that time, the feedback servo controller 50 connects the electric motor 132 and the power shaft 34.
rotation is stopped to stop displacement of the moldable material from the injection chamber 18.

Preferably, during the injection cycle, the feedback servo υ
The machine 50 is programmed to displace the device during the first portion of the injection cycle according to the monitored rate of displacement of the moldable material from the injection chamber 18. Also, 'noido back servo! If m! Vessel 5
0 71-1 to control the device which is displaced during the second portion of the injection cycle in response to the monitored pressure of the moldable material in conduit 24 as described above. It is further preferred that the first part of the injection cycle corresponds to an initial part of the cycle and that the second part of the injection cycle corresponds to a subsequent part of the injection cycle.

In a preferred embodiment of the invention, control of the injection of the moldable material during the first part of the injection cycle to control of the injection of the moldable material over the second part of the injection cycle is performed.
This switch to III reduces the preset injection capacity to about 5
0% is being displaced from the injection chamber 18 into the mold cavity 14 as occurs when the injection chamber 18 is being displaced from the injection chamber 18 into the mold cavity 14. The parameters by which the injection of moldable material is controlled during the injection cycle do not limit the invention. For example, the injection of moldable material from the injection chamber 18 into the mold cavity 14 may be performed without controlling the injection cycle at any part of the injection cycle according to a monitored pressure and a displacement rate that is displaced from the injection chamber 18 without controlling the injection cycle. It can only be controlled based on quantity.

In a preferred embodiment of the invention disclosed herein, a feedback servo control tlli5t50 is monitored to control the displacement device during curing of material in the mold cavity after the mold cavity is initially filled. An R distillation device t that responds to the applied pressure is provided. Typically, as the material in the mold cavity 14 hardens, it contracts and tends to reduce the pressure in the mold cavity 14. As the pressure in the mold cavity 14 begins to drop during this curing, the feedback servo controller 50 can be activated to control the electric motor 32 to turn the power @34;
Piston 30 is thereby advanced within injection chamber 18 to add additional moldable material to mold cavity 14 and maintain moldable material pressure within mold cavity 14 .

Feedback servo III m unit 50 can be programmed to perform the actions of the dwell routine in response to the voltage difference signal generated by comparator@46. Furthermore, if the moldable material passes into the cavity 14 and the pressure of the moldable material in the cavity 14 increases above the preset pressure command set point, the comparator 4
6 generates a voltage of opposite polarity, and the feedback servo a IIJ a unit 50 controls the electric motor 32 to generate power @34.
can be programmed to rotate in a direction opposite to the pressure overshoot in the cavity 14.

According to a preferred embodiment of the invention, apparatus 10 further includes means for moving injection nozzle 25 into and out of engagement with inlet 28 of molding tool 12. As embodied herein, the moving device includes a pneumatically or electrically driven actuator, shown generally at 80 in FIG. The actuator 80 is controlled by a programmable logic controller (PLO) 81 which acts at least in part as a relay to feed back signals to the servo 1IilJIll''150.
and transmits signals to actuator 80 .

For example, after the correct injection capacity of moldable material has been drawn into the injection chamber, feedback servo controller 50 generates a signal that is transmitted through lead 82 to PLO 81. During response, PLO 81 relays a signal through lead 83 to cutout sb to extend nozzle 25 into engagement with inlet 28 of forming tool 12 . Also, PLC81
can receive signals from and communicate signals to control panel 62. This signal can be representative of the status of the molding operation and can be displayed on the IIIJm panel 62 for monitoring and tracking by the operator.

FIG. 2 shows a flowchart of the programmed logic of feedback servo control 1+a 50 in a preferred embodiment of the invention. At step 84, command signals corresponding to the preset injection parameters are input to the 1AIII machine 50. Step 8
At 6, the microprocessor subassembly of the feedback servo controller 50 determines the rotational speed of the electric motor 32 and power shaft 34 required for the preset injection capacity and the preset displacement rate and acceleration of the moldable material. The rotation speeds of the electric motor 32 and the power shaft 34 are calculated.

At step 88, feedback servo controller 50 listens to control valve 22 and operates electric motor 32 to remove piston 30.
away from outlet 26 and a preset injection capacity of moldable material from reservoir 16 into injection chamber 18 . At step 90, feedback servo controller 50 signals actuator 80 to extend injection nozzle 25 into engagement with inlet 28. At step 92, the servo positioner subassembly of feedback servo i-controller 50 performs an injection cycle according to preset injection parameters. During the first part of the injection cycle, displacement of the moldable material is controlled only according to preset displacement acceleration and velocity commands. During the second part of the injection cycle, the displacement of the moldable material is also controlled according to the pressure signal generated by the pressure transducer 42.

At step 94, feedback servo controller 50:
The dwell routine begins upon receipt of a signal from comparator 46 corresponding to a preset command pressure set point available in mold cavity 14 . The dwell routine is also initiated by the feedback servo controller 50 after a preset injection capacity of moldable material has been displaced from the injection chamber 18.

At step 96, after completion of the dwell routine, feedback servo controller 50 signals actuator 60 to draw injection nozzle 25 from inlet 28 and remove excess moldable material to prime the device for the next injection cycle. Can be purged to

Referring to FIG. 3, the steps of the method of the present invention for molding an article in a closed mold cavity are illustrated with an inlet for receiving the molding phase 11 material from the outlet of the injection chamber. There is. At step 100, moldable material from the injection chamber is displaced into the mold cavity. At step 102, at least one of the rate of displacement of the moldable material from the injection chamber and the pressure of the moldable material in the mold cavity is monitored. At step 104, displacement of the moldable material from the injection chamber is controlled in response to the monitoring step to regulate the flow of the moldable material into the mold cavity.

Preferably, the displacing step includes displacing the moldable material from the injection chamber with a mechanical actuator driven by an electric motor. In a preferred embodiment of the present invention, a mechanical actuator driven by a motor includes an electric motor 32 that drives a motor 34 operably coupled to a piston 30 via a worm assembly 36 and a piston rod 38. Be prepared.

The monitoring step includes a substep of sensing rotation of the power shaft and the control step includes a substep of determining a displacement and rate of moldable material displaced from the injection chamber in accordance with the sensed rotation of the power shaft. It is even more preferable.

The high degree of control over the injection parameters that can be achieved with the apparatus and method of the present invention as described above determines the continuous displacement of the moldable material into the mold cavity, thereby causing a portion of the mold cavity to A new and useful analysis method for determining the order and nature of flow patterns filled with formable materials is provided. Such physical analysis provides a very important means for analyzing defects in molded articles. For example, when a moldable material is injected into a mold cavity, e.g. around a ceramic core that defines cooling air flow passages in the article to be molded, cracking, breaking or warping of the ceramic core may occur. It often results from stresses placed on the ceramic core by the flow of moldable material into the mold cavity.

Utilizing the analysis results of the actual state analysis method of the present invention described below, the mold cavity 14 is It is possible to solve such problems by relocating the inlet 28 or by changing the way air is vented from the mold t-cavity when the mold cavity is filled with moldable material. Furthermore, the analysis results using the actual analysis method of the present invention show that the ceramic core is supported within the mold cavity, thereby reducing the stress generated by the flow of the formable material around the helical core in the mold cavity. You can get a decision on what needs to be offset. Furthermore, the analytical results of the present analytical method show that the displacement of the moldable material into the mold cavity changes the flow pattern of the moldable feed around the ceramic core disposed in the mold cavity. You can obtain a decision that may be changed. Many other benefits of the reality analysis method of the present invention will be readily apparent to those skilled in the art.

Referring to FIG. 4, the steps of the reality analysis method are illustrated in a flow diagram. At step 200, a first predetermined amount of moldable material is displaced into a mold cavity. The first predetermined amount of moldable material is less than the volume of the mold cleavage. At step 202, the partial pattern formed at step 200 is removed from the mold cavity after curing. At step 204, a second predetermined amount of moldable material is injected into the empty mold cavity, the second predetermined amount of moldable material being incrementally greater than the first predetermined loss. It is a volumetric formable material. Step 2
At 06, the pattern formed in step 204 is removed from the mold cavity after curing. At step 208,
The patterns formed by each successive displacement of material into the mold cavity are compared to determine the order in which portions of the mold cavity are filled with moldable material.

FIG. 5 illustrates (photograph) a plurality of partially formed patterns formed using the steps of the reality analysis method of the present invention. A side-by-side comparison of successively formed articles shows a flow pattern that filled the mold cavity. If a defect occurs in the molded pattern, analysis of the manner in which the mold cavity is filled will result in various changes as described above to eliminate the defect.

Additional benefits and modifications will readily occur to those skilled in the art. Therefore, the invention is not limited to the particular set of representative devices and illustrative examples shown and described in its broader aspects. Accordingly, departures may be made from such details without departing from the spirit and scope of the general inventive concept as defined in the claims and their equivalents.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an apparatus incorporating the teachings of the present invention;
Figure 2 shows the feedback seabot shown in Figure 1.
is a flow diagram of the programmed logic of till <;
FIG. 3 is a flowchart illustrating the steps of the method of the present invention, FIG. 4 is a flowchart illustrating the steps of the method of analyzing the present invention, and FIG. 5 is a flowchart illustrating the results of the method of analyzing the present invention. To do! FIG. 3 is a diagram illustrating accurately a plurality of successively formed partial patterns arranged at /v; FIG. DESCRIPTION OF SYMBOLS 10... Article molding device, 12... Die or molding tool, 14... Mold cavity, 16... Reservoir, 18...
... Injection chamber, 20 ... Conduit, 22 ... Control valve, 25
...injection nozzle, 26...outlet, 28...inlet,
30... Piston, 32... Electric motor, 34... Power shaft, 36... Worm gear assembly, 38... Screw!・N rod, 40...Reservoir, 42...Pressure transducer, 4
6... Comparator device, 50... Feedback servo 111611! , 62... Control panel, 80... Actuator, 81... Programmable logic controller.

Claims (1)

[Scope of Claims] (1) An apparatus for molding an article, comprising: a die defining a mold cavity for receiving moldable material; and a die defining a mold cavity for receiving moldable material; an injection chamber for containing, a device for conveying moldable material from the injection chamber to the mold cavity, a device for displacing the moldable material from the injection chamber through the conduction device and into the mold cavity; a device for monitoring at least one of the rate of displacement of the moldable material conducted into the mold cavity and the pressure of the moldable material in the mold cavity; An apparatus for forming an article, comprising: a device for controlling the displacement device to adjust the rate of displacement of a formable material. (2) The article forming apparatus according to claim 1, wherein the control device includes a feedback servo controller. (3) The apparatus for forming an article according to claim 1, wherein the injection chamber includes a cylinder and a piston assembly, and the cylinder and piston are movable relative to each other. (4) The displacement device includes a prime mover device for rotatably driving a power shaft, and a motor device operably connected to the power shaft and the piston to convert rotational motion of the power shaft into linear motion of the piston. A device for forming an article according to claim 2, comprising a rotary to linear motion converter device. (5) The article forming apparatus according to claim 4, wherein the control device includes a feedback servo controller. (6) The monitoring device includes a resolver device for detecting rotation of the power shaft, and the control device determines the amount of displacement of the moldable material displaced from the injection chamber in accordance with the detected rotation of the power shaft. 5. Apparatus for forming an article according to claim 4, comprising a device for determining speed and velocity. (7) The article forming apparatus according to claim 6, wherein the control device controls the prime mover device according to the detected rotation of the power shaft. (8) Claim 4, wherein the control device is responsive to the monitored pressure of the formable material to control the prime mover device.
Apparatus for forming the article described in paragraph. (9) the article is molded during an injection cycle, and the controller controls the displacement device during a first portion of the injection cycle according to the monitored displacement rate of the moldable material; the second of the injection cycle according to the monitored pressure.
2. An apparatus for forming an article according to claim 1, wherein the displacement device is controlled during a portion of the process. 10. Claim 9, wherein the monitoring device includes a pressure transducer for monitoring the pressure of the moldable material in the transmission device and for generating an electrical signal in accordance with the monitored pressure. equipment for forming articles. (11) a device for the controller to generate an electrical signal in accordance with a predetermined commanded pressure set point, and for comparing the electrical signal generated by the pressure transducer with an electrical signal corresponding to the commanded set point; and a comparator device for generating a command signal according to the difference between the two electrical signals. 12. The apparatus of claim 11, wherein the control device controls the displacement device during the second portion of the injection cycle in accordance with a command signal generated by a comparator device. 13. Apparatus for forming an article according to claim 1, wherein the control device includes a retention device responsive to monitoring pressure to control a displacement device as material in the mold cavity hardens. 14. The article of claim 13, wherein the monitoring device includes a pressure transducer for monitoring the pressure of the moldable material in the conductive device and for generating an electrical signal in accordance with the monitored pressure. molding equipment. (15) means for the controller to generate an electrical signal in accordance with a predetermined commanded pressure set point, and for comparing the electrical signal generated by the pressure transducer with an electrical signal corresponding to the commanded set point; and a comparator device for generating a command signal according to the difference between the two electrical signals. (16) said retention device displaces the displacement device during curing of the moldable material in accordance with a command signal generated by a comparator device to maintain a substantially constant pressure of the moldable material in the mold cavity; 16. An apparatus for forming an article according to claim 15 for controlling: (17) the residence device controlling the displacement device to vary the pressure in the mold cavity as the moldable material hardens; Claim 13 that can operate as follows:
Apparatus for forming the article described in paragraph. (18) The control device includes a device for receiving an input command, and the input command is a) maximum displacement velocity of the moldable material, b) maximum displacement acceleration of the moldable material, and c) into the mold cavity. d) a commanded pressure set point corresponding to a desired pressure of the moldable material in the mold cavity; Device. (19) The article forming apparatus according to claim 18, wherein the control device controls the displacement device according to the input command. (20) An apparatus for molding an article, the die defining a mold cavity for receiving moldable material; and an injection molding material for containing the moldable material injected into the mold cavity. a chamber, a device for conducting moldable material from the injection chamber to the mold cavity, a device for displacing the moldable material from the injection chamber through the conduction device and into the mold cavity; a device for monitoring the displacement and velocity of the moldable material being conducted; and controlling the displacement device to adjust the flow of the moldable material into the mold cavity in response to the monitoring device. A device for forming an article, comprising: (21) The apparatus for molding an article according to claim 20, wherein the injection chamber includes a cylinder and a piston assembly, and the cylinder and piston are movable relative to each other. (22) The displacement device includes a prime mover device for rotatably driving a power shaft, and a prime mover device operably connected to the power shaft and the piston to convert rotational motion of the power shaft into linear motion of the piston. 22. Apparatus for forming an article according to claim 21, comprising a rotary to linear motion converter device. (23) The monitoring device includes a resolver device for detecting rotation of the power shaft, and the control device determines the displacement amount and speed of the moldable material displaced from the injection chamber according to the detected rotation of the power shaft. 23. An apparatus for forming an article according to claim 22, comprising an apparatus for determining. (24) A method for forming an article in a sealed mold cavity having an inlet for receiving moldable material from an outlet of the injection chamber, the method comprising: transferring the moldable material from the injection chamber into the mold cavity; monitoring at least one of the rate of displacement of the moldable material from the injection chamber and the pressure of the moldable material in the mold cavity; and displacing the moldable material into the mold cavity. controlling the displacement of the moldable material from the injection chamber in response to the step of monitoring to adjust the rate of displacement of the article. (25) A method of forming an article according to claim 24, wherein the displacing step includes a substep of displacing the formable material from the injection chamber with a prime mover driven mechanical actuator. 26. A method of forming an article according to claim 25, wherein the displacing step includes the substep of controlling a prime mover driven mechanical actuator with a feedback servo controller. (27) A method for molding an article according to claim 24, wherein the control step includes a substep of controlling the displacement of the moldable material with a feedback servo controller. (28) the injection chamber comprises a cylinder having a reciprocating piston disposed therein, the displacement step driving said piston linearly with a rotary to linear motion converter coupled to a rotating prime mover drive power shaft; 25. A method of forming an article according to claim 24, including the substep of: (29) The method for molding an article according to claim 28, wherein the monitoring step includes a substep of detecting rotation of the power shaft. (30) A method of forming an article according to claim 29, wherein the controlling step includes a substep of determining the displacement and speed of the formable material displaced from the injection chamber in accordance with the sensed rotation of the power shaft. . (34) The method of forming an article according to claim 29, wherein the control step includes a substep of controlling the prime mover according to the detected rotation of the power shaft. (32) the article is molded during an injection cycle, and the controlling step controls displacement of the moldable material from the injection chamber over a first portion of the injection cycle of the moldable material according to the monitored displacement rate; and controlling the displacement of the moldable material from the injection chamber over the second portion of the injection cycle in accordance with the monitored pressure. method of forming articles. (33) controlling the displacement of the moldable material over a second portion of the injection cycle comprises generating a first electrical signal in accordance with a predetermined commanded pressure set point of the moldable material in the mold cavity; generating a second electrical signal in accordance with the monitored pressure of the moldable material; and comparing the first and second electrical signals to determine a difference therebetween; 33. A method of forming an article as claimed in claim 32, including the substep of controlling the displacement of the formable material according to the difference between the first and second electrical signals. (34) causing displacement of the moldable material from the injection chamber upon sensing a predetermined pressure of the moldable material; 34. The method of forming an article of claim 33, further comprising the step of displacing additional formable material from the injection chamber during dropping to maintain a predetermined pressure therein. (35) the displacing step comprises: (a) displacing a first predetermined amount of moldable material into the mold cavity, the first predetermined amount being less than the volume of the mold cavity; (b) removing the article formed in step (a) from the mold cavity after curing; and (c) displacing a second predetermined amount of moldable material into the empty mold cavity; (d) removing the article formed in step (c) from the mold cavity after curing; (e) comparing the article with each successive displacement of material into the mold cavity to determine the order in which the mold cavity is filled with moldable material; A method for molding an article according to claim 24. (36) A method for determining the flow pattern of moldable material injected into a mold cavity, comprising: (a) displacing a first predetermined amount of moldable material into the mold cavity; , (b) removing the article formed in step (a) from the mold cavity after curing, and (c) forming the moldable material. displacing a second predetermined amount of the material into the empty mold cavity, the second predetermined amount being an incrementally larger volume of moldable material than the first predetermined amount; ) removing the article formed in step (c) from the mold cavity after curing; and (e) entering the mold cavity to determine the order in which portions of the mold cavity are filled with moldable material. comparing the articles formed by each successive displacement of the material of the material;