Electro Fluid Driven Actuator and Method
20230373142 · 2023-11-23
Inventors
Cpc classification
B29C2945/76204
PERFORMING OPERATIONS; TRANSPORTING
B29C2045/2848
PERFORMING OPERATIONS; TRANSPORTING
International classification
B29C45/27
PERFORMING OPERATIONS; TRANSPORTING
Abstract
An injection molding apparatus (5), comprising: a first fluid drive cylinder (940c, 941c, 942c), a second fluid drive cylinder (940ac, 941ac, 942ac) interconnected to a valve pin (1040, 1041, 1042), wherein the first fluid drive cylinder (940c, 941c, 942c) and the second fluid drive cylinder (940ac, 941ac, 942ac) are interconnected in an arrangement wherein reciprocating movement of a piston (940p, 941p, 942p) of the first cylinder drives concomitant back and forth movement of a piston (940ap, 941ap, 942ap) of the second cylinder and concomitant back and forth movement of the valve pin (1040, 1041, 1042); an electrically powered actuator (940, 941, 942) adapted to drive the piston of the first cylinder reciprocally according to a drive program such that the valve pin (1040, 1041, 1042) is driven between gate closed and gate open positions and selected positions therebetween.
Claims
1. An injection molding apparatus, comprising: an injection molding machine adapted to inject a flow of injection fluid to a heated manifold, the heated manifold adapted to distribute the injection fluid to a flow channel that is adapted to deliver the injection fluid to a gate of a mold cavity; a first fluid drive cylinder having a first piston disposed within the first fluid drive cylinder adapted to be driven reciprocally upstream and downstream within the first fluid drive cylinder; a second fluid drive cylinder having a second piston disposed within the second fluid drive cylinder and interconnected to a valve pin wherein the first fluid drive cylinder and the second fluid drive cylinder are interconnected in an arrangement wherein reciprocating movement of the first piston drives concomitant back and forth movement of the second piston and concomitant back and forth movement of the valve pin along a selected path of travel (Y) within the flow channel between gate closed and gate open positions; an electrically powered actuator adapted to drive the first piston reciprocally within the first fluid drive cylinder according to a drive program that instructs the electrically powered actuator to drive the valve pin between the gate closed and gate open positions and one or more selected positions therebetween.
2. An apparatus according to claim 1 wherein the electrically powered actuator is the sole source of drive force on the first piston.
3. An apparatus according to claim 1 wherein the first fluid drive cylinder and the second fluid drive cylinder are drivably interconnected in a closed fluid circuit arrangement.
4. Apparatus of claim 1 wherein the electrically powered actuator is mounted in a position remote from the heated manifold.
5. Apparatus of claim 1 wherein the electrically powered actuator is mounted such that the electrically powered actuator is isolated from substantial communication of heat with the heated manifold.
6. Apparatus of claim 1 wherein the first fluid drive cylinder and the second fluid drive cylinder are interconnected via fluid sealed conduit that enables drive fluid to flow directly between the first fluid drive cylinder and the second fluid drive cylinder, the fluid sealed conduit including one or more connectors adapted to enable the conduit interconnection between the first fluid drive cylinder and the second fluid drive cylinder to be readily disconnected and readily connected.
7. Apparatus of claim 1 wherein the electrically powered actuator comprises either a linear actuator or a rotatable actuator having a driver arranged to drive the first piston reciprocally upstream and downstream within the first fluid drive cylinder.
8. Apparatus of claim 7 wherein the electrically powered actuator includes a linear travel converter adapted to drive the first piston along a selected linear converter path of travel (XX) that is non-coaxial with an axis (X) of the driver.
9. The apparatus of claim 1 further comprising a controller and one or more of: (i) a pressure sensor adapted to sense pressure of drive fluid (DF) disposed within a fluid drive cylinder and generate a signal indicative of the pressure of the drive fluid (DF), (ii) a position sensor adapted to sense axial position of the second piston or the valve pin and generate a signal indicative of axial position of the second piston or the valve pin, (iii) a position sensor adapted to sense one or more of axial position of a piston, rotational position and velocity of a rotor of the electrically powered actuator and generate a signal indicative of one or the other or both of rotational position and velocity of the rotor, (iv) a sensor adapted to sense one or the other or both torque exerted by or current used by the electrically powered actuator and generate a signal indicative of one or the other or both of torque and current, the controller including an algorithm that utilizes one or more signals generated by the pressure sensor, the position sensor or the torque or current sensor as a variable to controllably drive the second piston and the valve pin: (a) to one or more predetermined axial positions during the course of an injection cycle, or, (b) at one or more upstream or downstream velocities during the course of an injection cycle, or, (c) to follow or match a preselected profile of pin positions or pin velocities during the course of an injection cycle, or, (d) to open or close the gate or to trigger a movement or change in movement at a selected sensed pressure, (e) to trigger an alarm indicative of degree of deviation in pressure of the drive fluid (DF) from one or more preselected desired pressures, (f) upstream beginning from the gate closed position to a selected second intermediate upstream position at a first velocity, upstream from the second intermediate upstream position to a fully gate open position at one or more second velocities that are higher than the first velocity.
10. The apparatus of claim 1 further comprising a signal converter for converting signals generated by an injection molding machine (IMM) having a drivably rotatable barrel screw (BS) that generates an injection fluid, wherein the injection molding machine (IMM) includes a machine controller (MC) or a control unit (HPU) that generates one or more directional control valve compatible signals (VPS), wherein the direction control valve compatible signals (VPS) are compatible for use by a signal receptor, interface or driver of a standard fluid directional control valve to instruct the fluid directional control valve to move to a position that routes a source of drive fluid to flow in a direction that drives an interconnected fluid drivable actuator to move in a direction that operates to begin an injection cycle and to move in a direction that operates to end an injection cycle, wherein the signal converter is interconnected to the machine controller (MC) or control unit (HPU), the signal converter receiving and converting the directional control valve compatible signals (VPS) to a command signal (MOPCS, PDCVS) that is compatible with a signal receptor or interface of an electrically powered actuator or a signal receptor or interface of a proportional directional control valve (V, V1, V2) that drives a fluid driven actuator, wherein the signal converter includes a processor that converts the command signals (MOPCS, PDCVS) into a form, frequency, power or format that is usable by the signal receptor or interface of the electrically powered actuator or by the signal receptor or interface of the proportional directional control valve (V, V1, V2) to respectively cause the electrically powered actuator or the proportional directional control valve (V, V1, V2) to be driven in a direction that operates to either begin an injection cycle or to end an injection cycle.
11. An injection molding method, comprising: providing a valve pin that is disposed in a flow channel, the flow channel adapted to pass injection fluid though a gate and into a mold cavity; providing a first fluid drive cylinder having a first piston that is interconnected to a second fluid drive cylinder having a second piston in an arrangement wherein reciprocating movement of the first piston drives concomitant back and forth movement of the second piston, interconnecting the valve pin to the second piston in an arrangement wherein reciprocating movement of the second piston drives concomitant back and forth movement of the valve pin through the flow channel between gate open and gate closed positions, providing an electrically powered actuator that is interconnected to the first piston; injecting a flow of the injection fluid to a heated manifold; distributing the injection fluid, via the heated manifold, to the flow channel; driving the first piston reciprocally within the first fluid drive cylinder via the electrically powered actuator according to a drive program that instructs the valve pin to be driven between the gate closed and gate open positions and one or more selected positions therebetween.
12. A method according to claim 11 further comprising using the electrically powered actuator as the sole source of drive force on the first piston.
13. A method according to claim 11 further comprising drivably interconnecting the first fluid drive cylinder and the second fluid drive cylinder in a closed fluid circuit arrangement.
14. A method according to claim 11 further comprising disposing the electrically powered actuator in a position remote from the heated manifold.
15. A method according to claim 11 further comprising sensing one or more of: (i) pressure of drive fluid (DF) disposed within a fluid drive cylinder, (ii) axial position of the second piston or the valve pin, (iii) one or the other or both rotational position and velocity of a rotor of the electrically powered actuator, (iv) one or the other or both torque exerted by or current used by the electrically powered actuator and generate a signal indicative of one or the other or both of torque and current, and, using the sensed pressure, the sensed position, the sensed torque or current as a variable in an algorithm that controllably drives the second piston and the valve pin: (a) to one or more predetermined axial positions during the course of an injection cycle, or, (b) at one or more upstream or downstream velocities during the course of an injection cycle, or, (c) to follow or match a preselected profile of pin positions or pin velocities during the course of an injection cycle, or, (d) to open or close the gate or to trigger a movement or change in movement at a selected sensed pressure, or, (e) to trigger an alarm indicative of degree of deviation in pressure of the drive fluid (DF) from one or more preselected desired pressures, or, (f) upstream beginning from the gate closed position to a selected second intermediate upstream position at a first velocity, upstream from the second intermediate upstream position to a fully gate open position at one or more second velocities that are higher than the first velocity.
16. An injection molding system comprising: an injection molding machine (IMM) that delivers an injection fluid to a heated manifold mounted between a top clamp plate and a mold having a cavity, the heated manifold adapted to distribute the injection fluid to a flow channel that is adapted to pass the injection fluid through a gate to the mold cavity; a first fluid drive cylinder having a first piston disposed within the first fluid drive cylinder adapted to be driven reciprocally upstream and downstream within the first fluid drive cylinder; a second fluid drive cylinder having a second piston disposed within the second fluid drive cylinder and interconnected to a valve pin wherein the first fluid drive cylinder and the second fluid drive cylinder are interconnected in an arrangement wherein reciprocating movement of the first piston drives concomitant back and forth movement of the second piston and concomitant back and forth movement of the valve pin along a selected path of travel (Y) within the flow channel between gate closed and gate open positions; an electrically powered actuator adapted to drive the first piston reciprocally within the first fluid drive cylinder according to a program that instructs the valve pin to be driven between the gate closed and gate open positions and one or more selected positions therebetween.
17. The system of claim 16 wherein the second actuator is mounted to one or the other or both of the heated manifold and the top clamp plate.
18. The system of claim 16 wherein the electrically powered actuator is the sole source of drive force on the first piston.
19. The system of claim 16 wherein the first fluid drive cylinder and the second fluid drive cylinder are drivably interconnected in a closed fluid circuit arrangement.
20. Apparatus of claim 1 wherein the electrically powered actuator is mounted in a position remote from the heated manifold.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0188] The accompanying drawings contain numbering of components and devices that correspond to the numbering appearing in the following Summary.
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[0213] The nozzles can be configured as shown in
[0214] Such a valve pin and nozzle configuration as shown in
DETAILED DESCRIPTION OF THE INVENTION
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[0217] The downstream fluid driven actuator 940a, 941a, 942a is drivably interconnected to a valve pin 1040, 1041, 1042 that is arranged to be reciprocally movable along a linear drive axis Y to close and open a gate 32, 34, 36 to a mold cavity 30.
[0218] The valve pins 1040, 1041, 1042 are controllably drivable according to a predetermined program to any axial positions intermediate the gate 32, 34, 36 closed and gate open positions. Programmed controllable drive of the electrically powered actuators 940, 941, 942 is typically carried out employing a predetermined algorithm that operates using one or more sensor signals as a variable in the algorithm to control movement of the valve pins beginning from the gate closed position to one or more intermediate positions upstream of gate closed up to a fully gate open position.
[0219] The algorithm and program used to control operation of the electrically powered actuators can employ any one or more of multiple sensor signals as variables to control pin position, pin velocity and pin movement generally. As shown in
[0220] Such a position sensor as sensor 950,
[0221] A position signal can also be generated and used in the control algorithm by employing a suitable position sensor such as a Hall Effect sensor or a trip sensor as described to detect the position of the driver 940ld of a linear electrically powered actuator as shown in
[0222] A position signal can also be generated and used in the control algorithm by employing a position sensor that senses the rotational position of a rotary electrically powered actuator such as by use of an encoder that detects the rotational position of the rotor of a rotary actuator.
[0223] The drive fluid circuit of the
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[0226] Similar to the
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[0235] While rotary electric actuators are commonly used, linearly driven actuators or linear actuators can alternatively be used in place of rotary electric actuators. One example of a linear actuator that uses electric energy to directly produce linear motion in instead of rotary motion, is a proportional solenoid as shown in
[0236] The linear motor,
[0237] A linear actuator is particularly suited for use in a configuration where the drive axis of the actuator and the pin movement axis X are coaxially arranged A linear actuator as described can be used to drive any pin drive member 940ld as an alternative to the rotor based actuators described herein.
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[0239] In alternative embodiments, the center gate 32 and associated actuator 940 and valve pin 1040 can remain open at, during and subsequent to the times that the lateral gates 34, 36 are opened such that fluid material flows into cavity 30 through both the center gate 32 and one or both of the lateral gates 34, 36 simultaneously.
[0240] When the lateral gates 34, 36 are opened and fluid material NM is allowed to first enter the mold cavity into the stream 102p that has been injected from center nozzle 22 past gates 34, 36, the two streams NM and 102p mix with each other. If the velocity of the fluid material NM is too high, such as often occurs when the flow velocity of injection fluid material through gates 34, 36 is at maximum, a visible line or defect in the mixing of the two streams 102p and NM will appear in the final cooled molded product at the areas where gates 34, 36 inject into the mold cavity. By injecting NM at a reduced flow rate for a relatively short period of time at the beginning when the gate 34, 36 is first opened and following the time when NM first enters the flow stream 102p, the appearance of a visible line or defect in the final molded product can be reduced or eliminated.
[0241] The rate or velocity of upstream withdrawal of pins 1041, 1042 starting from the closed position is controlled via controller 16,
[0242] The position sensors 950 for sensing the position of the actuator pistons and their associated valve pins (such as 1040, 1041, 1042) and feed such position information to controller 16 for monitoring purposes. As shown, fluid material 18 is injected from an injection machine into a manifold runner 19 and further downstream into the bores 44, 46 of the lateral nozzles 24, 22 and ultimately downstream through the gates 32, 34, 36. When the pins 1041, 1042 are withdrawn upstream to a position where the tip end of the pins 1041 are in a fully upstream open position such as shown in
[0243] Beginning from a gate closed position, the pins 1040, 1041 can be controllably withdrawn at one or more reduced velocities (less than maximum) for one or more periods of time over the entirety of the length of the path RP over which flow of mold material 1153 is restricted. Preferably the pins are withdrawn at a reduced velocity over more than about 50% of RP and most preferably over more than about 75% of the length RP. As described with reference to
[0244] The trace or visible lines that appear in the body of a part that is ultimately formed within the cavity of the mold on cooling above can be reduced or eliminated by reducing or controlling the velocity of the pin 1041, 1042 opening or upstream withdrawal from the gate closed position to a selected intermediate upstream gate open position that is preferably 75% or more of the length of RP.
[0245] RP can be about 1-8 mm in length and more typically about 2-6 mm and even more typically 2-4 mm in length. As shown in
[0246] As used in this application with regard to various monitoring and control systems, the terms “controller,” “component,” “computer” and the like are intended to refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution. For example, a component or controller may be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a server and the server can be a component. One or more components may reside within a process and/or thread of execution and a component may be localized on one computer and/or distributed between two or more computers.
[0247] Claimed methods of the present invention may also be illustrated as a flow chart of a process of the invention. While, for the purposes of simplicity of explanation, the one or more methodologies shown in the form of a flow chart are described as a series of acts, it is to be understood and appreciated that the present invention is not limited by the order of acts, as some acts may, in accordance with the present invention, occur in a different order and/or concurrent with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all illustrated acts may be required to implement a methodology in accordance with the present invention.
[0248] In various embodiments of the invention disclosed herein, the term “data” or the like means any sequence of symbols (typically denoted “0” and “1”) that can be input into a computer, stored and processed there, or transmitted to another computer. As used herein, data includes metadata, a description of other data. Data written to storage may be data elements of the same size, or data elements of variable sizes. Some examples of data include information, program code, program state, program data, other data, and the like.
[0249] As used herein, computer storage media or the like includes both volatile and nonvolatile, removable and non-removable media for storage of information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes RAM, ROM, EEPROM, FLASH memory or other memory technology, CD-ROM, digital versatile disc (DVDs) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store desired information and which can be accessed by the computer.
[0250] The methods described herein may be implemented in a suitable computing and storage environment, e.g., in the context of computer-executable instructions that may run on one or more processors, microcontrollers or other computers. In a distributed computing environment (for example) certain tasks are performed by remote processing devices that are linked through a communications network and program modules may be located in both local and remote memory storage devices. The communications network may include a global area network, e.g., the Internet, a local area network, a wide area network or other computer network. It will be appreciated that the network connections described herein are exemplary and other means of establishing communications between the computers may be used.
[0251] A computer may include one or more processors and memory, e.g., a processing unit, a system memory, and system bus, wherein the system bus couples the system components including, but not limited to, the system memory and the processing unit. A computer may further include disk drives and interfaces to external components. A variety of computer-readable media can be accessed by the computer and includes both volatile and nonvolatile media, removable and nonremovable media. A computer may include various user interface devices including a display screen, touch screen, keyboard or mouse.
[0252] A “controller,” as used herein also refers to electrical and electronic control apparatus that comprise a single box or multiple boxes (typically interconnected and communicating with each other) that contain(s) all of the separate electronic processing, memory and electrical signal generating components that are necessary or desirable for carrying out and constructing the methods, functions and apparatuses described herein. Such electronic and electrical components include programs, microprocessors, computers, PID controllers, voltage regulators, current regulators, circuit boards, motors, batteries and instructions for controlling any variable element discussed herein such as length of time, degree of electrical signal output and the like. For example a component of a controller, as that term is used herein, includes programs, controllers and the like that perform functions such as monitoring, alerting and initiating an injection molding cycle including a control device that is used as a standalone device for performing conventional functions such as signaling and instructing an individual injection valve or a series of interdependent valves to start an injection, namely move an actuator and associated valve pin from a gate closed to a gate open position. In addition, although fluid driven actuators are employed in typical or preferred embodiments of the invention, actuators powered by an electric or electronic motor or drive source can alternatively be used as the actuator component.
[0253] The actuator controller 16 typically includes additional instructions that can instruct a valve pin 1041, 1042, 1040 to be driven either upstream or downstream starting from either a fully closed downstream or a fully upstream, gate open position at one or more reduced upstream or reduced downstream velocities over at least the beginning portion of the upstream path of travel of the valve pins 1040, 1041, 1042 or the latter portion of the downstream path of travel of the valve pins toward the gates 32, 34, 36 where the tip end 1142 of the pin 1041 restricts flow of the injection fluid through the gate RP, RP2, RP3 such as shown in
[0254] In one embodiment, the valve pin is driven along the axis
[0255] In an embodiment such as shown in
[0256] In alternative embodiments, the center gate 32 and associated actuator 940e, 940p and valve pin 1040 can remain open at, during and subsequent to the times that the lateral gates 34, 36 are opened such that fluid material flows into cavity 30 through both the center gate 32 and one or both of the lateral gates 34, 36 simultaneously. When the lateral gates 34, 36 are opened and fluid material NM is allowed to first enter the mold cavity into the stream 102p that has been injected from center nozzle 22 past gates 34, 36, the two streams NM and 102p mix with each other. If the velocity of the fluid material NM is too high, such as often occurs when the flow velocity of injection fluid material through gates 34, 36 is at maximum, a visible line or defect in the mixing of the two streams 102p and NM will appear in the final cooled molded product at the areas where gates 34, 36 inject into the mold cavity. By injecting NM at a reduced flow rate for a relatively short period of time at the beginning when the gate 34, 36 is first opened and following the time when NM first enters the flow stream 102p, the appearance of a visible line or defect in the final molded product can be reduced or eliminated.
[0257] In a conventional system, the injection molding machine IMM includes its own internal manufacturer supplied machine controller that generates standardized beginning of cycle gate closed and end of cycle gate open and gate closed machine voltage signals VS typically 0 volts for gate open and 24 volts for gate open (or 0 volts and 120 volts respectively). The standardized machine voltage signals VS are typically sent either directly to the solenoids of a master directional control valve 12 (that controls the direction of flow of actuator drive fluid into or out of the drive chambers of all of the plurality of fluid driven actuators 940f, 941f, 9420 to cause the directional control valve 12 (DCV) to move to a gate closed or gate open actuator drive fluid flow position. Or, the same standardized voltage signals VSC can be sent to the directional control valve 12 via the actuator controller 16 which generates the same standardized voltage signals VSC as the VS signals in response to receipt from a screw position sensor SPSR of a machine screw position signal SPS sent by the injection molding machine IMM to the actuator controller 16, the actuator controller 16 thus generating the same beginning of cycle and end of cycle control voltage signals VSC as the machine IMM can otherwise generate and send VS directly to the directional control valve 12. Thus, where conventional standardized directional control valves 12 are used, the sending of start of cycle and end of cycle signals can be simplified via electrical or electronic signal connections directly to the internal signal generator or controller contained within the injection molding machine.
[0258] Electrically powered actuators or electric motors and proportional directional control valves cannot directly receive and utilize a standardized 0 volt (gate closed), 24 volt (gate open) or 0 volt (gate closed) 120 volt (gate open) signals generated by the start and stop cycle controller or signal generator that is typically included in a conventional injection molding machine.
[0259] As shown in a generic schematic form in
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[0262] In an alternative embodiment, the electric actuators 940e, 941e, 942e can be mounted remote from the manifold 40 and mechanically interconnected to a first upstream fluid cylinder 940c, 941c, 942c which is coupled to a second downstream fluid actuator 940a, 941a, 942a in the same manner as described above with respect to the
[0263] In the
[0264] The distribution channel 19 commonly feeds three separate nozzles 20, 22, 24 which all commonly feed into a common cavity 30 of a mold 33. The nozzle 22, 24, 26 as shown can be controlled upstream by a configuration of an electric motor actuator 940e mechanically interconnected to a first upstream fluid actuator 940c and downstream actuator 940a as described above regarding the
[0265] As shown in the
[0266] Also as with a conventional system, the
[0267] A signal converter 1500,
[0268] Thus the standard start and stop control signals generated by an IMM (VS, VSC) can operate in conjunction with the converter 1500 to instruct either the electric actuators, 940e, 941e, 942e to at least initiate or begin an injection cycle (such as by instructing the actuators 940e, 941e, 942e to drive a valve pin upstream from a gate closed position) and to end or stop an injection cycle (such as by instructing the actuators 940e, 941e, 942e, 940p, 941p, 942p to drive a valve pin downstream from a gate open position into a gate closed position).
[0269] The
[0270] Most preferably the physical or mechanical electric signal connectors that are typically used to connect a wire or cable from the IMM (or machine controller MC) to the signal conversion device 1500, are the same physical or mechanical connectors that are used in conventional systems to connect the IMM (or machine controller MC) to the DCVs of a conventional system as described with reference to
[0271] As shown in
[0272] The MOCPS and PDCVS signals include signals that correspond to the VS signals that operate to affect the beginning and end of an injection cycle.
[0273] Typically the
[0274] The actuator controller 16 can include a program that receives and processes a real time signal indicative of a condition of the injection fluid 18 or a component of the apparatus (10) such as rotational position of a rotor 940r, 941r, 942r or axial linear position of a valve pin 1040, 1041, 1042. The real time signals sent to and received by the actuator controller 16 are generated by one or more of position sensors 950, 951, 952 or fluid condition sensors SN, SC. The sensors detect and send a signal to the actuator controller that is typically indicative of one or more of rotational position (sensors 950, 951, 952) of a rotor 940r, 941r, 942r or of linear axial position of a valve pin 1040, 1041, 1042. The fluid condition sensors typically comprise one or more of a pressure or temperature sensor SN that senses injection fluid 18 within a manifold channel 19 or a nozzle channel 42, 44, 46 or senses pressure or temperature of the injection fluid SC within the cavity 30 of the mold 33.
[0275] The actuator controller 16 can include a program that processes the received signal(s) from one or more of the sensors 950, 951, 952, SN, SC according to a set of instructions that use the received signals as a variable input or other basis for controlling one or more of the position or velocity of the actuators 940e, 941e, 942e or their associated valve pins 1040, 1041, 1042 throughout all or selected portion of the duration of an injection cycle or all or a portion of the length of the upstream or downstream stroke of the actuators 940e, 941e, 942e.
[0276] As shown the controller 16 can be included within and comprise a component of the converter 1500. Where the converter 1500 includes a controller 16 that includes position and velocity control instructions, the converter 1500 can thus send its machine open close power signals MOCPS (or valve open close signals PDCVS) together with position velocity signals (PVS) to either the electric actuators 940e, 941e, 942e or proportional directional control valves V, V1, V2. The control signals MOCPS and PDCVS thus include a signal that has been converted from and corresponds to one or the other of the converted VS signals received by the converter 1500 from the IMM controller MC or the HPU. The position or velocity control signals PVS can control the position or velocity of the valve pin according to any predetermined profile of pin position or velocity versus time of injection cycle. The form, format, intensity and frequency of the MOCPS, PDCVS and PVS signals are compatible with the signal receiving interface of the electric actuators 940e, 941e, 942e or valves V, V1, V2.
[0277] User Interface and Target Profiles
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[0279] The graphs of
[0280] The valve pin associated with graph 1235 is opened sequentially at 0.5 seconds after the valves associated with the other three graphs (1237, 1239 and 1241) were opened at 0.00 seconds. At approximately 6.25 seconds, at the end of the injection cycle, all four valve pins are back in the closed position. During injection (for example, 0.00 to 1.0 seconds in
[0281] Through the user interface, target profiles can be designed, and changes can be made to any of the target profiles using standard (e.g., windows-based) editing techniques. The profiles are then used by controller 1016 to control the position of the valve pin. For example,
[0282] Screen 1300 is generated by a windows-based application performed on the user interface, e.g., any of the user interfaces 21 shown in
[0283] A profile 1310 includes (x, y) data pairs, corresponding to time values 1320 and pressure values 1330 which represent the desired pressure sensed by the pressure transducer for the particular nozzle being profiled. The screen shown in
[0284] The screen also allows the user to select the particular valve pin they are controlling displayed at 1390, and name the part being molded displayed at 1400. Each of these parameters can be adjusted independently using standard windows-based editing techniques such as using a cursor to actuate up/down arrows 1410, or by simply typing in values on a keyboard. As these parameters are entered and modified, the profile will be displayed on a graph 1420 according to the parameters selected at that time.
[0285] By clicking on a pull-down menu arrow 1391, the user can select different nozzle valves in order to create, view or edit a profile for the selected nozzle valve and cavity associated therewith. Also, a part name 1400 can be entered and displayed for each selected nozzle valve.
[0286] The newly edited profile can be saved in computer memory individually, or saved as a group of profiles for a group of nozzles that inject into a particular single or multi-cavity mold. The term “recipe” is used to describe one or more of profiles for a particular mold and the name of the particular recipe is displayed at 1430 on the screen icon.
[0287] To create a new profile or edit an existing profile, first the user selects a particular nozzle valve of the group of valves for the particular recipe group being profiled. The valve selection is displayed at 1390. The user inputs an alpha/numeric name to be associated with the profile being created, for family tool molds this may be called a part name displayed at 1400. The user then inputs a time displayed at 1340 to specify when injection starts. A delay can be with particular valve pins to sequence the opening of the valve pins and the injection of melt material into different gates of a mold.
[0288] The user then inputs the fill (injection) pressure displayed at 1350. In the basic mode, the ramp from zero pressure to max fill pressure is a fixed time, for example, 0.3 seconds. The user next inputs the start pack time to indicate when the pack phase of the injection cycle starts. The ramp from the filling phase to the packing phase is also fixed time in the basic mode, for example, 0.3 seconds.
[0289] The final parameter is the cycle time which is displayed at 1380 in which the user specifies when the pack phase (and the injection cycle) ends. The ramp from the pack phase to zero pressure may be instantaneous when a valve pin is used to close the gate, or slower in a thermal gate due to the residual pressure in the cavity which will decay to zero pressure once the part solidifies in the mold cavity.
[0290] User input buttons 1415 through 1455 are used to save and load target profiles. Button 1415 permits the user to close the screen. When this button is clicked, the current group of profiles will take effect for the recipe being profiled. Cancel button 1425 is used to ignore current profile changes and revert back to the original profiles and close the screen. Read Trace button 1435 is used to load an existing and saved target profile from memory. The profiles can be stored in memory contained in one or more of the operator interface 21, the main MCU 9, and the recipe storage MCU 16. Save trace button 1440 is used to save the current profile. Read group button 1445 is used to load an existing recipe group. Save group button 1450 is used to save the current group of target profiles for a group of nozzle valve pins. The process tuning button 1455 allows the user to change the settings (for example, the gains) for a particular nozzle valve in a control zone. Also displayed is a pressure range 1465 for the injection molding application.