WO2010088844A1 - Synchronized control of hot-runners for multi-cavity injection molding - Google Patents
Synchronized control of hot-runners for multi-cavity injection molding Download PDFInfo
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- WO2010088844A1 WO2010088844A1 PCT/CN2010/000170 CN2010000170W WO2010088844A1 WO 2010088844 A1 WO2010088844 A1 WO 2010088844A1 CN 2010000170 W CN2010000170 W CN 2010000170W WO 2010088844 A1 WO2010088844 A1 WO 2010088844A1
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- runners
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- 230000001360 synchronised effect Effects 0.000 title claims abstract description 60
- 238000001746 injection moulding Methods 0.000 title description 8
- 238000000034 method Methods 0.000 claims description 11
- 238000002347 injection Methods 0.000 claims description 8
- 239000007924 injection Substances 0.000 claims description 8
- 230000001052 transient effect Effects 0.000 claims description 7
- 238000009529 body temperature measurement Methods 0.000 claims description 4
- 239000000047 product Substances 0.000 description 11
- 239000000463 material Substances 0.000 description 7
- 238000000465 moulding Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 5
- 238000013461 design Methods 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
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- 230000003252 repetitive effect Effects 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 229920001903 high density polyethylene Polymers 0.000 description 1
- 239000004700 high-density polyethylene Substances 0.000 description 1
- 239000012943 hotmelt Substances 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 238000010094 polymer processing Methods 0.000 description 1
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- 210000003813 thumb Anatomy 0.000 description 1
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/72—Heating or cooling
- B29C45/73—Heating or cooling of the mould
- B29C45/7306—Control circuits therefor
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/26—Moulds
- B29C45/27—Sprue channels ; Runner channels or runner nozzles
- B29C45/2737—Heating or cooling means therefor
Definitions
- the present invention relates to a hot-runners control system and in particular to a multi-cavity injection molding where multiple hot-runners are used simultaneously in one mold.
- Injection molding is one of the most popular polymer processing techniques in modern industries.
- multi-cavity mold as illustrated by Figure l(a)
- hot-runner systems is widely used since multiple parts can be produced simultaneously within one molding cycle.
- the industry has been plagued for decades by the problem of cavity-to-cavity inconsistency, caused by the runner imbalance, as demonstrated in Figure l(b).
- the imbalance problem such as melt temperature distribution, runner diameter, mold temperature and injection time, etc.
- the temperature may oscillate around the set point due to the repetitive nature of injection molding.
- the temperature varies as a combined result of shear heating and uneven melt temperature distribution.
- a dynamic steady state can be reached after several cycles when the temperature exhibits a regular oscillation.
- Figure 2 (b) For multi-cavity mold, even though each runner achieves its own dynamic steady state, they are usually separately controlled, as shown in Figure 2 (b). This non-synchronization may lead to the significant temperature difference among runners hence the imbalanced flow of material to each cavity, and consequently large part-to-part inconsistency within one shot.
- FIG. 3 The block diagram of conventional multi-cavity hot-runners control system is shown in Fig. 3.
- the mold has N hot-runners, and each equipped with one or more heaters. For the sake of easy explanation without losing the generality, it is assumed only one heater is used for each hot-runner. It is clearly shown in Fig. 3 that in the conventional system, each hot-runner's temperature is measured and controlled by one controller. The controllers try to maintain the temperatures at the preset trajectory, neglecting the different dynamics of each hot-runner. There's no communication and synchronization between these controllers.
- An object of the present invention is to provide a multi-cavity hot-runners control system which can provide synchronized control of multiple hot-runners, minimize the cavity-to-cavity imbalance and achieve uniformed flows in all the cavities.
- a multi-cavity hot-runners control system which comprises one synchronized controller connecting to a plurality of hot-runners feeding multiple cavities in a same mold and used to provide synchronized control of the plurality of hot-runners, the synchronization controller measures temperatures of the plurality of hot-runners simultaneously and provides synchronized control of the plurality of hot-runners based on measured temperatures and a synchronization algorithm, so as to make all the plurality of hot-runners have a same thermal history and balance the flow in the plurality of hot-runners.
- the synchronization control of the plurality of hot-runners can be achieved by a predictive control which is developed from a traditional predictive control.
- the synchronization algorithm for every hot-runner is given based on a first cost function of the predictive control as follows.
- J(N 11 N 71 N 31 N n ) is the first cost function
- TV 1 can be set as a dead time of temperature
- N 2 can be selected as a transient time of temperature near an operating point
- N 3 can be set as a length of one injection cycle
- N n indicates how quickly the synchronization controller can achieve the set point
- y ⁇ t + j 1 t) is the temperature prediction at time t + j using the information up to time i
- w(t + j) is the set point at time t + j
- Au(t + J-V) is the synchronization controller output variation at time t + j ⁇
- y k+l (t + j ⁇ t) -y k (t + j ⁇ t) is a difference of temperature predictions of every two adjacent hot-runners
- ⁇ (j), ⁇ (j) and ⁇ j) are weighting factors.
- the operating point is the same as the set point.
- the temperature difference among different hot-runners can be minimized, thus can balance the flow in of the plurality of hot-runners.
- each of the plurality of hot-runners further includes an individual controller.
- the synchronization controller determines set point profiles for the individual controllers based on the measured temperatures and the synchronization algorithm; then the individual controllers provides synchronized control of the plurality of hot-runners based on corresponding set point profiles.
- the synchronization algorithm can be given based on a second cost function.
- J(N 11 N 21 N 3 ) ⁇ t) -K (t+ J ⁇ O ) + ⁇ ⁇ )[y( t +j ⁇ t )-w ( t+j ) ]
- J(N 11 N 21 N 3 ) is the second cost function
- JV 1 can be set as a dead time of temperature
- N 2 can be selected as a transient time of temperature near an operating point
- N 3 can be set as a length of one injection cycle
- y(i + j ⁇ i) is the temperature prediction at time t + j using the information up to time t
- w(t + j) is the set point at time t + j
- y k+] (t + j ⁇ t)- y k (t + f ⁇ t) is a difference of temperature predictions of every two adjacent hot-runners
- ⁇ (j) and ⁇ (j) are weighting factors.
- the curvature difference among set point profiles of the plurality of hot-runners can be minimized, thus can balance the flow in the plurality of hot-runners.
- the synchronization controller may include a multi-channel temperature measurement module for measuring temperatures of the plurality of hot-runners simultaneously; a synchronization algorithm module providing control parameters for the plurality of hot-runners based on the synchronization algorithm and the measured temperatures; and a multi-channel heater control module for controlling the plurality of hot-runners based on the control parameters for the plurality of hot-runners simultaneously.
- a method for providing synchronized control of a plurality of hot-runners feeding multiple cavities in a same mold comprising: measuring temperatures of a plurality of hot-runners by a synchronization controller simultaneously; and providing synchronized control of the plurality of hot-runners based on measured temperatures and a synchronization algorithm so as to make all the plurality of hot-runners have a same thermal history.
- the step of providing synchronized control of the plurality of hot-runners based on measured temperatures and a synchronization algorithm may comprise determining set point profiles for the plurality of hot-runners based on the measured temperatures and the synchronization algorithm; sending set point profiles to corresponding individual controllers for the plurality of hot-runners by the synchronization controller; and controlling the temperatures of the plurality of hot-runners based on corresponding determined set point profiles by corresponding individual controllers, so as to provide synchronized control of the plurality of hot-runners and balance the flow in the plurality of hot-runners.
- the step of providing synchronized control of the plurality of hot-runners based on measured temperatures and a synchronization algorithm may comprise determining control parameters for the plurality of hot-runners based on the measured temperatures and the synchronization algorithm by the synchronization controller; and controlling the temperatures of the plurality of hot-runners based on corresponding control parameters for the plurality of hot-runners by the synchronization controller, so as to provide synchronized control of the plurality of hot-runners.
- the present invention provides a synchronized control strategy for different hot-runners in the same multi-cavity mold, such that material in each hot-runner goes through the same thermal history. With the same thermal history and pressure source, material can fill in different mold-cavities in a balanced way thus eliminating the cavity imbalance problem.
- Fig.l is an example of imbalance in multi-cavity injection molding
- Fig.2 is a temperature curve versus time of a hot-runner
- Fig.3 is a view illustrating a structure of a conventional hot-runner control system
- Fig.4 is a view illustrating a synchronized control system according to a first embodiment of the present invention
- Fig.5 is a flowchart illustrating how to provide synchronized control of multi-cavity hot-runners according to the first embodiment of the present invention
- Fig.6 is a diagram illustrating a weight difference between a product produced through Hot-runner 1 and a product produced through Hot-runner 2 without a synchronized temperature control;
- Fig.7 is a diagram illustrating a weight difference between a product produced through Hot-runner 1 and a product produced through Hot-runner 2 with a synchronized temperature control according to the first embodiment of the present invention
- Fig.8(a) is a view illustrating a synchronized control system according to a second embodiment of the present invention
- Fig.8(b) is a view illustrating a structure of the synchronization controller included in the synchronized control system shown in Fig.8(a);
- Fig.9 is a flowchart illustrating how to provide synchronized control of multi-cavity hot-runners according to the second embodiment of the present invention.
- the new synchronized control system will have one synchronization controller.
- the synchronization controller can both measure and control a plurality of hot-runners feeding multiple cavities in a multi-cavity mold simultaneously using synchronization algorithms.
- Fig.4 is a view illustrating a synchronized control system according to a first embodiment of the present invention.
- the synchronized control system is a version updated from the configuration of the conventional hot-runner control system shown in Fig.3.
- the synchronized control system according to the first embodiment of the present invention includes one synchronization controller for providing synchronized control of N hot-runners (Hot-runner 1, Hot-runner2, ⁇ • ⁇ , Hot-runncrN).
- N hot-runners is equipped with one or more heaters. For the sake of easy explanation without losing the generality, it is assumed only one heater is used for each hot-runner.
- each of N hot-runners further comprises an individual controller used to control the heaters of the hot-runner. In particular, each individual controller is used to control the temperature of the corresponding hot-runner.
- Hot-runnerl is provided with an individual controller Controller 1 and a heater Heaterl.
- Hot-runner2 is provided with an individual controller Controlled and a heater Heater2.
- Hot-runnerN is provided with an individual controller ControllerN and a heater HeaterN.
- the synchronization controller is added on top of the conventional control system and is connected to all the individual controllers for N hot-runners.
- the synchronization controller measures all the N temperatures in N hot-runners (Temp Measurement 1, Temp Measurement 2, • • • , Temp Measurement N) simultaneously and determines set point profiles for all the individual controllers through certain synchronization algorithm based on measured N temperatures. Then the individual controllers control the corresponding heaters of N hot-runners based on determined corresponding set point profiles.
- a set point profile is a temperature curve varying with time with respect to a hot-runner, which oscillates around a set point due to the repetitive nature of injection molding.
- the synchronization control provided by the synchronization controller is achieved by a predictive control.
- a traditional predictive control uses a cost function 1 as follows. 0>
- J (N x , N 2 , N 11 ) is the cost function
- JV 1 is the minimum prediction horizon
- N 2 is the maximum prediction horizon
- N 11 is the control horizon
- y ⁇ t + / I 0 is the output prediction at time t + j using the information up to time t (the output is temperature in the present invention)
- w(t + j) is the set point at time t + j
- Au(t + j -I) is the controller output variation at time t + j — I
- ⁇ (j) and ⁇ (j) are weighting factors
- E is the mathematical expectation.
- a corresponding controller minimizes this cost function and finds controller output u .
- the parameters in the cost function (1) cannot be determined rigorously. However, they can be selected according to some rules of thumb.
- the prediction horizons N x can be set as the dead time of temperature, and N 2 can be selected as the transient time of temperature near the operating point.
- Control horizon, N tl indicates how quickly the controller can achieve the set point.
- a large N 11 causes slow but smooth control while a small N 11 results in an aggressive and quick response.
- the ratio of ⁇ (j) and ⁇ j) determines the weight of predictive error and controller output variance. Generally the ratio is determined by the gain between temperature output y and heating power u with respect to every hot-runner.
- the synchronization algorithm is based on a cost function 2 as follows. ⁇ )[y(t+J ⁇ V-M>(t+j)] (2 )
- N 3 is a prediction horizon of i N, synchronization control, and it can be set as a length of one injection cycle in the present invention
- J ) 4+1 (t + j ⁇ t) - y k (t + j ' ⁇ t) is a difference of temperature predictions of every two adjacent hot-runners.
- Other parameters can be determined in the same way as the cost function 1.
- This added term in the cost function 2 indicates the temperature difference among different hot-runners.
- Weighting factors, ⁇ and ⁇ can be determined using trail-and-error method. They can be selected as equal values in the beginning, and tuned according to the control performance.
- a large ⁇ / ⁇ ratio gives a large weight to temperature difference, which is the main purpose of the synchronization control, while a small value of ⁇ / ⁇ ratio leads to a large weight of the set point tracking error.
- ⁇ needs to be increased.
- the synchronization controller due to the fact that each of N hot-runners is provided with an individual controller, the synchronization controller only needs to determine the set point profile w for every individual controller.
- the Au term that is, the synchronization controller output variance
- a design objective is to find a proper set point profile for every individual controller to minimize the cost function 2.
- the curvature difference among the set point profiles of all the hot-runners is minimized.
- all the hot-runners have a same thermal history. That is, in a molding cycle, the temperature difference of any two of the set point profiles remains the same all the time as much as possible. In other words, there is a translation of up-and-down between any two set point profiles.
- communication and synchronization among different hot-runners installed in the same multi-cavity mold is created by means of
- the synchronization controller may send all determined set point profiles to corresponding individual controllers.
- each one temperature control loop for a hot-runner will be a cascade control.
- the individual controllers can control the corresponding heaters based on the determined set point profiles inputted from the synchronization controller simultaneously.
- Controllerl can control Heaterl based on the set point profile for Hot-runner 1 sent from the synchronization controller
- Controlled can control Heatcr2 based on the set point profile for Hot-runner2 sent from the synchronization controller
- ControllerN can control HeaterN based on the set point profile for Hot-runnerN sent from the synchronization controller, and all these controlling processes are performed simultaneously.
- a synchronized control of the plurality of hot-runners can be provided, thus can minimize the cavity-to-cavity imbalance and achieve uniformed flow in all the activities.
- Fig.5 gives a procedure of achieving the synchronized control of the plurality of hot-runners according to the first embodiment of the present invention.
- the synchronization controller measures N temperatures for N hot-runners simultaneously.
- the synchronization controller determines set point profiles for N hot-runners based on the synchronization algorithm and measured temperatures.
- the synchronization controller sends all set point profiles to corresponding individual controllers for the plurality of hot-runners simultaneously.
- the individual controllers control the corresponding heaters of the plurality of hot-runners according to the corresponding set point profiles so as to achieve synchronization among the plurality of hot-runners.
- the synchronization controller is added on the top of the conventional control system wherein an individual controller is provided for every hot-runner.
- Fig.6 and Fig.7 give a exemplary example.
- the injection molding machine used is Chen-Hsong MJ55; the material molded is HDPE; the individual controller is Mold-Master; Hot-runner temperature is set to 200 ° C; only two upper mold cavities are used for this test. All the molding conditions are same except that the synchronized temperature control is employed for Fig.7.
- Fig.6 is a diagram illustrating a weight difference between a product produced through Hot-runner 1 and a product produced through Hot-runner 2 without a synchronized temperature control.
- the temperature profile 1 for Hot-runner 1 and the temperature profile 2 for Hot-runner 2 show different thermal histories.
- the weight difference between these two products is 0.1 Ig.
- Fig.7 is a diagram illustrating a weight difference between a product produced through Hot-runner 1 and a product produced through Hot-runner 2 with a synchronized temperature control according to the first embodiment of the present invention.
- parameters in the cost function (2) arc selected in which N 1 is 8 seconds, N 2 is 18 seconds, N 3 is 40 seconds, ⁇ is 25 and ⁇ is 1.
- the temperature profile 1 for Hot-runner 1 and the temperature profile 2 for Hot-runner 2 show same thermal histories. That is, Hot-runner 1 temperature change with time and Hot-runner 2 temperature change with time throughout a molding cycle show a same trend. In this case, the weight difference between these two products is 0.05g.
- Fig.8 illustrates a synchronized control system according to a second embodiment of the present invention. Compared with the synchronized control system according to the first embodiment of the present invention, individual controllers are eliminated from the hot-runners in the synchronized control system according to the second embodiment. So, system resources can be saved.
- the synchronization controller is directly connected to all the heaters for the plurality of hot-runners.
- the heaters for the plurality of hot-runners are all directly controlled by the synchronization controller.
- the synchronization controller may include a multi-channel temperature measurement module, a synchronization algorithm module and a multi-channel heater control module, wherein the multi-channel temperature measurement module measures temperatures of N hot-runners simultaneously; the synchronization algorithm module provides a synchronization algorithm and control parameters for N hot-runners can be provided based on the synchronization algorithm; and based on the control parameters for N hot-runners, the multi-channel heater control module controls N hot-runners simultaneously so as to achieve synchronization among the plurality of hot-runners.
- the synchronized control of N hot-runners is also achieved by a predictive control. Since heaters of N hot-runners are directly controlled by the synchronization controller, outputs of the synchronization controller which are heating power to be applied to the heaters of N hot-runners are desired.
- the predictive control uses a cost function different from that used in the first embodiment of the present invention.
- the synchronization algorithm is based on a cost function 3 as follows.
- cost function 3 the term ⁇ t)) is added as the cost function 1. Since the temperatures are measured and controlled simultaneously by the synchronization controller, the ⁇ w(Y+ /-1) term is included to calculate the synchronization controller output directly. All the parameters in cost function 3 can be determined same as the cost functions 1 and 2. In this case,
- M>(t + j) may be fixed to a set-point temperature.
- the cost function 3 the temperature difference among different hot-runners is minimized.
- the synchronization control of the plurality of hot-runners can be achieved.
- the multi-channel heater control module of the synchronization controller controls all the heaters in all the hot-runners simultaneously and in a synchronized fashion based on the synchronization controller output from the synchronization algorithm module, so as to provide synchronized control of different temperature zones.
- the synchronization algorithm is not limited to minimizing the temperature differences among different zones.
- Fig.9 is a flowchart illustrating how to provide synchronized control of multi-cavity hot-runners according to the second embodiment of the present invention.
- the synchronization controller measures all the temperatures of N hot-runners simultaneously.
- the synchronization controller determines control parameters for the plurality of hot-runners based on the measured temperatures and the synchronization algorithm.
- the synchronization controller controls heaters of the plurality of hot-runners based on control parameters determined, so as to provide synchronized control of the plurality of hot-runners.
- the present invention provides a synchronized control strategy for different hot-runners in the same multi-cavity mold, such that material in each hot-runner goes through the same thermal history. With the same thermal history and pressure source, material can fill in different mold-cavities in a balanced way thus eliminating the cavity imbalance problem.
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Abstract
The present invention discloses a multi-cavity hot-runners control system which comprises one synchronized controller used to control a plurality of hot-runners synchronously. Each of the plurality of hot-runners includes one or more heaters. The synchronization controller is connected to all the plurality of hot-runners, measures all temperatures of the plurality of hot-runners simultaneously and provides synchronized control of the plurality of hot-runners based on measured temperatures and a synchronization algorithm. The synchronized control of the plurality of hot-runners is achieved by a predictive control.
Description
Synchronized control of Hot-runners for Multi-cavity Injection Molding
CROSS REFERENCE TO RELATED APPLICATIONS
This application is based on and claims priority of the US Provisional Application No. 61/202,228 filed on February 6, 2009, and entitled MULTI-CAVITY HOT-RUNNERS CONTROL SYSTEM, the entire disclosure of which is herein incorporated by reference.
Field of the Invention
The present invention relates to a hot-runners control system and in particular to a multi-cavity injection molding where multiple hot-runners are used simultaneously in one mold.
Background of the Invention
Injection molding is one of the most popular polymer processing techniques in modern industries. To achieve a higher productivity and lower cost, multi-cavity mold, as illustrated by Figure l(a), with hot-runner systems is widely used since multiple parts can be produced simultaneously within one molding cycle. Despite of the benefits of multi-cavity molding, the industry has been plagued for decades by the problem of cavity-to-cavity inconsistency, caused by the runner imbalance, as demonstrated in Figure l(b). There are many factors that could cause the imbalance problem, such as melt temperature distribution, runner diameter, mold temperature and injection time, etc.
Previous researchers attempted to tackle this problem from the mold design perspective. Nowadays mold design itself is no longer a big problem, since there arc computer aided design software and highly automated tooling technology available in the market. However, the temperature control of the hot-runner system, which is overlooked, may have at least an equal importance to the mold design. Currently, each hot-runner is controlled separately by an individual controller. There is no coordination and synchronization among different hot-runner controllers installed in the same multi-cavity mold. Atypical heating profile of hot-runner is shown in Figure 2 (a). The runner is heated to certain temperature at the beginning to remove moisture from the heaters, referred to as soft start. After that it is heated to a predetermined
set-point for molding operation. During the consecutive molding operation, the temperature may oscillate around the set point due to the repetitive nature of injection molding. When the hot melt flows through the hot-runner, the temperature varies as a combined result of shear heating and uneven melt temperature distribution. A dynamic steady state can be reached after several cycles when the temperature exhibits a regular oscillation. For multi-cavity mold, even though each runner achieves its own dynamic steady state, they are usually separately controlled, as shown in Figure 2 (b). This non-synchronization may lead to the significant temperature difference among runners hence the imbalanced flow of material to each cavity, and consequently large part-to-part inconsistency within one shot. For example, if the temperature of the runner of mold cavity 1 is higher than that of cavity 3 in Figure 1 (a), the pressure drop in runner 1 is lower than runner 3, that is, it is easier for melt to be injected into cavity 1. It is therefore highly likely that cavity 1 is fully filled whereas the short shot problem occurs in cavity 3. In the worst case scenario, mold flash problem could happen in cavity 1, as illustrated in Figure 1 (b). In other cases, even if there is no obvious short shot or flash problem, the material in different cavity has experienced different thermal history and as a result, the final product is inconsistent in part quality, such as density, dimension and mechanical properties.
From above analysis, it can be concluded that temperature variations in the hot-runners not only produce continuous batch-to-batch variation, but also cause cavity-to-cavity inconsistency within one shot. The conventional hot-runner control system is shown in Figure 3, in which each hot-runner is measured and controlled individually using one controller.
The block diagram of conventional multi-cavity hot-runners control system is shown in Fig. 3. The mold has N hot-runners, and each equipped with one or more heaters. For the sake of easy explanation without losing the generality, it is assumed only one heater is used for each hot-runner. It is clearly shown in Fig. 3 that in the conventional system, each hot-runner's temperature is measured and controlled by one controller. The controllers try to maintain the temperatures at the preset trajectory, neglecting the different dynamics of each hot-runner. There's no communication and synchronization between these controllers.
Summary of the Invention
An object of the present invention is to provide a multi-cavity hot-runners control system which can provide synchronized control of multiple hot-runners,
minimize the cavity-to-cavity imbalance and achieve uniformed flows in all the cavities.
According to one aspect of the present invention, a multi-cavity hot-runners control system is provided, which comprises one synchronized controller connecting to a plurality of hot-runners feeding multiple cavities in a same mold and used to provide synchronized control of the plurality of hot-runners, the synchronization controller measures temperatures of the plurality of hot-runners simultaneously and provides synchronized control of the plurality of hot-runners based on measured temperatures and a synchronization algorithm, so as to make all the plurality of hot-runners have a same thermal history and balance the flow in the plurality of hot-runners.
In the present invention, the synchronization control of the plurality of hot-runners can be achieved by a predictive control which is developed from a traditional predictive control.
The synchronization algorithm for every hot-runner is given based on a first cost function of the predictive control as follows.
JlN,.NvN3.N.) l t)) \+ ∑ δύ)- [j>(t + j \ O- w(t + β] j- ])}1
Wherein, J(N11N71N31Nn) is the first cost function, TV1 can be set as a dead time of temperature, N2 can be selected as a transient time of temperature near an operating point, N3 can be set as a length of one injection cycle, Nn indicates how quickly the synchronization controller can achieve the set point, y{t + j 1 t) is the temperature prediction at time t + j using the information up to time i , w(t + j) is the set point at time t + j , Au(t + J-V) is the synchronization controller output variation at time t + j ~\ , yk+l(t + j \ t) -yk(t + j \ t) is a difference of temperature predictions of every two adjacent hot-runners, δ(j), γ(j) and λ{j) are weighting factors. Generally, the operating point is the same as the set point.
In this configuration, by minimizing the first cost function, the temperature difference among different hot-runners can be minimized, thus can balance the flow in of the plurality of hot-runners.
According to a preferred embodiment of the present invention, each of the plurality of hot-runners further includes an individual controller. In this case, the synchronization controller determines set point profiles for the individual controllers based on the measured temperatures and the synchronization algorithm; then the individual controllers provides synchronized control of the plurality of hot-runners based on corresponding set point profiles.
In the case that each of the plurality of hot-runners had an individual controller,
the synchronization algorithm can be given based on a second cost function.
J(N11N21N3 ) = \t)-K(t+J\O) + ∑ δύ)[y(t+j \ t)-w(t+j)]
Wherein, J(N11N21N3) is the second cost function, JV1 can be set as a dead time of temperature, N2 can be selected as a transient time of temperature near an operating point, N3 can be set as a length of one injection cycle, y(i + j \ i) is the temperature prediction at time t + j using the information up to time t , w(t + j) is the set point at time t + j , yk+](t + j \ t)- yk(t + f \ t) is a difference of temperature predictions of every two adjacent hot-runners, δ(j) and γ(j) are weighting factors. In this configuration, by minimizing the second cost function, the curvature difference among set point profiles of the plurality of hot-runners can be minimized, thus can balance the flow in the plurality of hot-runners.
According to another preferred embodiment of the present invention, the synchronization controller may include a multi-channel temperature measurement module for measuring temperatures of the plurality of hot-runners simultaneously; a synchronization algorithm module providing control parameters for the plurality of hot-runners based on the synchronization algorithm and the measured temperatures; and a multi-channel heater control module for controlling the plurality of hot-runners based on the control parameters for the plurality of hot-runners simultaneously.
According to another aspect of the present invention, a method for providing synchronized control of a plurality of hot-runners feeding multiple cavities in a same mold is provided, comprising: measuring temperatures of a plurality of hot-runners by a synchronization controller simultaneously; and providing synchronized control of the plurality of hot-runners based on measured temperatures and a synchronization algorithm so as to make all the plurality of hot-runners have a same thermal history.
According to a preferred embodiment of the present invention, the step of providing synchronized control of the plurality of hot-runners based on measured temperatures and a synchronization algorithm may comprise determining set point profiles for the plurality of hot-runners based on the measured temperatures and the synchronization algorithm; sending set point profiles to corresponding individual controllers for the plurality of hot-runners by the synchronization controller; and controlling the temperatures of the plurality of hot-runners based on corresponding determined set point profiles by corresponding individual controllers, so as to provide synchronized control of the plurality of hot-runners and balance the flow in the plurality of hot-runners.
According to another preferred embodiment of the present invention, the step of
providing synchronized control of the plurality of hot-runners based on measured temperatures and a synchronization algorithm may comprise determining control parameters for the plurality of hot-runners based on the measured temperatures and the synchronization algorithm by the synchronization controller; and controlling the temperatures of the plurality of hot-runners based on corresponding control parameters for the plurality of hot-runners by the synchronization controller, so as to provide synchronized control of the plurality of hot-runners.
The present invention provides a synchronized control strategy for different hot-runners in the same multi-cavity mold, such that material in each hot-runner goes through the same thermal history. With the same thermal history and pressure source, material can fill in different mold-cavities in a balanced way thus eliminating the cavity imbalance problem.
Brief Description of the drawings
The features of the present invention will appear more fully upon consideration of the exemplary embodiments of the invention, which are schematically set forth in the drawings, in which:
Fig.l is an example of imbalance in multi-cavity injection molding;
Fig.2 is a temperature curve versus time of a hot-runner;
Fig.3 is a view illustrating a structure of a conventional hot-runner control system;
Fig.4 is a view illustrating a synchronized control system according to a first embodiment of the present invention;
Fig.5 is a flowchart illustrating how to provide synchronized control of multi-cavity hot-runners according to the first embodiment of the present invention;
Fig.6 is a diagram illustrating a weight difference between a product produced through Hot-runner 1 and a product produced through Hot-runner 2 without a synchronized temperature control;
Fig.7 is a diagram illustrating a weight difference between a product produced through Hot-runner 1 and a product produced through Hot-runner 2 with a synchronized temperature control according to the first embodiment of the present invention;
Fig.8(a) is a view illustrating a synchronized control system according to a second embodiment of the present invention
Fig.8(b) is a view illustrating a structure of the synchronization controller
included in the synchronized control system shown in Fig.8(a);
Fig.9 is a flowchart illustrating how to provide synchronized control of multi-cavity hot-runners according to the second embodiment of the present invention.
Detailed description of the Exemplary Embodiments
Although the present invention will be described below with reference to exemplary embodiments thereof, the following exemplary embodiments and their modifications do not restrict the present invention.
The new synchronized control system according to the present invention will have one synchronization controller. The synchronization controller can both measure and control a plurality of hot-runners feeding multiple cavities in a multi-cavity mold simultaneously using synchronization algorithms.
Fig.4 is a view illustrating a synchronized control system according to a first embodiment of the present invention. In Figure 4 the synchronized control system is a version updated from the configuration of the conventional hot-runner control system shown in Fig.3. The synchronized control system according to the first embodiment of the present invention includes one synchronization controller for providing synchronized control of N hot-runners (Hot-runner 1, Hot-runner2, ■ • ■, Hot-runncrN). Each of N hot-runners is equipped with one or more heaters. For the sake of easy explanation without losing the generality, it is assumed only one heater is used for each hot-runner. In the first embodiment of the present invention, each of N hot-runners further comprises an individual controller used to control the heaters of the hot-runner. In particular, each individual controller is used to control the temperature of the corresponding hot-runner.
As shown in Fig.4, Hot-runnerl is provided with an individual controller Controller 1 and a heater Heaterl. Hot-runner2 is provided with an individual controller Controlled and a heater Heater2. Hot-runnerN is provided with an individual controller ControllerN and a heater HeaterN.
According to the first embodiment of the present invention, as shown in Fig.4, the synchronization controller is added on top of the conventional control system and is connected to all the individual controllers for N hot-runners.
The synchronization controller measures all the N temperatures in N hot-runners (Temp Measurement 1, Temp Measurement 2, • • • , Temp Measurement N) simultaneously and determines set point profiles for all the individual controllers
through certain synchronization algorithm based on measured N temperatures. Then the individual controllers control the corresponding heaters of N hot-runners based on determined corresponding set point profiles.
Wherein, a set point profile is a temperature curve varying with time with respect to a hot-runner, which oscillates around a set point due to the repetitive nature of injection molding.
In the present invention, the synchronization control provided by the synchronization controller is achieved by a predictive control.
As for the predictive control, references are made to:
(1) Clarke D. W., Mohtadi C. and Tuffs P. S. (1987). Generalized predictive control. Automatica, 23, 137.
(2) Camacho E. F. and Bordons C. (1995). Model predictive control in the process industry. Springer- Verlag, London, U. K.
As well-known, a traditional predictive control uses a cost function 1 as follows. 0>
Where J (Nx, N2, N11) is the cost function, JV1 is the minimum prediction horizon, N2 is the maximum prediction horizon, N11 is the control horizon, y{t + / I 0 is the output prediction at time t + j using the information up to time t (the output is temperature in the present invention), w(t + j) is the set point at time t + j , Au(t + j -I) is the controller output variation at time t + j — I , δ(j) and λ(j) are weighting factors, E is the mathematical expectation. A corresponding controller minimizes this cost function and finds controller output u .
It is commonly accepted that the parameters in the cost function (1) cannot be determined rigorously. However, they can be selected according to some rules of thumb. In the present invention, the prediction horizons Nx can be set as the dead time of temperature, and N2 can be selected as the transient time of temperature near the operating point. Control horizon, Ntl , indicates how quickly the controller can achieve the set point. A large N11 causes slow but smooth control while a small N11 results in an aggressive and quick response. The ratio of δ(j) and λ{j) determines the weight of predictive error and controller output variance. Generally the ratio is determined by the gain between temperature output y and heating power u with respect to every hot-runner.
For the synchronization controller in the synchronized control system according to the first embodiment of the present invention, the synchronization algorithm is based on a cost function 2 as follows.
δύ)[y(t+J \ V-M>(t+j)] (2)
Compared to the cost function 1 of the traditional predictive control, one term is
added, ∑ γϋ) where N3 is a prediction horizon of i N,
synchronization control, and it can be set as a length of one injection cycle in the present invention, J) 4+1 (t + j \ t) - yk (t + j' \ t) is a difference of temperature predictions of every two adjacent hot-runners. Other parameters can be determined in the same way as the cost function 1. This added term in the cost function 2 indicates the temperature difference among different hot-runners. Weighting factors, γ and δ, can be determined using trail-and-error method. They can be selected as equal values in the beginning, and tuned according to the control performance. A large γ/δ ratio gives a large weight to temperature difference, which is the main purpose of the synchronization control, while a small value of γ/δ ratio leads to a large weight of the set point tracking error. In this embodiment, since all the synchronization controller needs to do is to provide individual controllers with set point profiles, synchronization among different set point profiles is desired. In this case, γ needs to be increased.
In the present invention, by adding this term into the cost function 1 of the traditional predictive control, synchronization among different hot-runners installed in a same multi-cavity mold can be achieved.
In the first embodiment of the present invention, due to the fact that each of N hot-runners is provided with an individual controller, the synchronization controller only needs to determine the set point profile w for every individual controller. In this case the Au term (that is, the synchronization controller output variance) is neglected, and a design objective is to find a proper set point profile for every individual controller to minimize the cost function 2.
Through minimizing the cost function 2, the curvature difference among the set point profiles of all the hot-runners is minimized. Thus, all the hot-runners have a same thermal history. That is, in a molding cycle, the temperature difference of any two of the set point profiles remains the same all the time as much as possible. In other words, there is a translation of up-and-down between any two set point profiles.
According to the first embodiment, communication and synchronization among different hot-runners installed in the same multi-cavity mold is created by means of
the cost function 2, in which is included, thus
considering both the set point and synchronized control of different hot-runners.
After determining set point profiles for the individual controllers, the synchronization controller may send all determined set point profiles to corresponding individual controllers.
In Fig.4, if the synchronization controller determines the set point profiles and sends all the set point profiles to corresponding individual controllers, each one temperature control loop for a hot-runner will be a cascade control. In this case, the individual controllers can control the corresponding heaters based on the determined set point profiles inputted from the synchronization controller simultaneously. In particular, Controllerl can control Heaterl based on the set point profile for Hot-runner 1 sent from the synchronization controller, Controlled can control Heatcr2 based on the set point profile for Hot-runner2 sent from the synchronization controller, ..., ControllerN can control HeaterN based on the set point profile for Hot-runnerN sent from the synchronization controller, and all these controlling processes are performed simultaneously. Since the set point profiles for all the individual controllers are determined based on the synchronization algorithm, a synchronized control of the plurality of hot-runners can be provided, thus can minimize the cavity-to-cavity imbalance and achieve uniformed flow in all the activities.
Fig.5 gives a procedure of achieving the synchronized control of the plurality of hot-runners according to the first embodiment of the present invention. In step S51, the synchronization controller measures N temperatures for N hot-runners simultaneously. In step S52, the synchronization controller determines set point profiles for N hot-runners based on the synchronization algorithm and measured temperatures. After that, in step S53, the synchronization controller sends all set point profiles to corresponding individual controllers for the plurality of hot-runners simultaneously. In step S54, the individual controllers control the corresponding heaters of the plurality of hot-runners according to the corresponding set point profiles so as to achieve synchronization among the plurality of hot-runners.
In the first embodiment of the present invention, the synchronization controller is added on the top of the conventional control system wherein an individual controller
is provided for every hot-runner.
For the first embodiment of the present invention, Fig.6 and Fig.7 give a exemplary example. In the exemplary example, the injection molding machine used is Chen-Hsong MJ55; the material molded is HDPE; the individual controller is Mold-Master; Hot-runner temperature is set to 200 °C; only two upper mold cavities are used for this test. All the molding conditions are same except that the synchronized temperature control is employed for Fig.7.
Fig.6 is a diagram illustrating a weight difference between a product produced through Hot-runner 1 and a product produced through Hot-runner 2 without a synchronized temperature control. In Fig.6, without synchronized temperature control, the temperature profile 1 for Hot-runner 1 and the temperature profile 2 for Hot-runner 2 show different thermal histories. In this case, the weight difference between these two products is 0.1 Ig.
Fig.7 is a diagram illustrating a weight difference between a product produced through Hot-runner 1 and a product produced through Hot-runner 2 with a synchronized temperature control according to the first embodiment of the present invention. In the exemplary example, parameters in the cost function (2) arc selected in which N1 is 8 seconds, N2 is 18 seconds, N3 is 40 seconds, γ is 25 and δ is 1.
In Fig.7, with synchronized temperature control, the temperature profile 1 for Hot-runner 1 and the temperature profile 2 for Hot-runner 2 show same thermal histories. That is, Hot-runner 1 temperature change with time and Hot-runner 2 temperature change with time throughout a molding cycle show a same trend. In this case, the weight difference between these two products is 0.05g.
From these two figures, it can be seen that the weight difference can be much reduced with synchronization control according to the first embodiment of the present invention and the synchronized temperature can improve the evenness of product reflected by product weight.
Fig.8 illustrates a synchronized control system according to a second embodiment of the present invention. Compared with the synchronized control system according to the first embodiment of the present invention, individual controllers are eliminated from the hot-runners in the synchronized control system according to the second embodiment. So, system resources can be saved.
In this configuration, the synchronization controller is directly connected to all the heaters for the plurality of hot-runners. The heaters for the plurality of hot-runners are all directly controlled by the synchronization controller.
In this case, the synchronization controller may include a multi-channel
temperature measurement module, a synchronization algorithm module and a multi-channel heater control module, wherein the multi-channel temperature measurement module measures temperatures of N hot-runners simultaneously; the synchronization algorithm module provides a synchronization algorithm and control parameters for N hot-runners can be provided based on the synchronization algorithm; and based on the control parameters for N hot-runners, the multi-channel heater control module controls N hot-runners simultaneously so as to achieve synchronization among the plurality of hot-runners.
In this configuration, the synchronized control of N hot-runners is also achieved by a predictive control. Since heaters of N hot-runners are directly controlled by the synchronization controller, outputs of the synchronization controller which are heating power to be applied to the heaters of N hot-runners are desired. In this case, the predictive control uses a cost function different from that used in the first embodiment of the present invention. In particular, the synchronization algorithm is based on a cost function 3 as follows.
J(N,,N2,N,,NJ~ E H rO)I ∑&tJt + j\t)-yt(t + j\ t)) U f1 SQ)[M + J\ O→(t + J)] +∑A(/)[Δ«(/4 j-l)J
J J "<
(3)
In this cost function 3, the term \t)) is added
as the cost function 1. Since the temperatures are measured and controlled simultaneously by the synchronization controller, the Δw(Y+ /-1) term is included to calculate the synchronization controller output directly. All the parameters in cost function 3 can be determined same as the cost functions 1 and 2. In this case,
M>(t + j) may be fixed to a set-point temperature. By minimizing the cost function 3, the temperature difference among different hot-runners is minimized. Thus, the synchronization control of the plurality of hot-runners can be achieved.
In this case, the multi-channel heater control module of the synchronization controller controls all the heaters in all the hot-runners simultaneously and in a synchronized fashion based on the synchronization controller output from the synchronization algorithm module, so as to provide synchronized control of different temperature zones.
However, the synchronization algorithm is not limited to minimizing the
temperature differences among different zones.
Fig.9 is a flowchart illustrating how to provide synchronized control of multi-cavity hot-runners according to the second embodiment of the present invention. In step S91, the synchronization controller measures all the temperatures of N hot-runners simultaneously. In step S92, the synchronization controller determines control parameters for the plurality of hot-runners based on the measured temperatures and the synchronization algorithm. In step S93, the synchronization controller controls heaters of the plurality of hot-runners based on control parameters determined, so as to provide synchronized control of the plurality of hot-runners.
In summary, the present invention provides a synchronized control strategy for different hot-runners in the same multi-cavity mold, such that material in each hot-runner goes through the same thermal history. With the same thermal history and pressure source, material can fill in different mold-cavities in a balanced way thus eliminating the cavity imbalance problem.
The foregoing description of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the present invention to the precise form disclosed, and obviously, many modifications and variations are possible. Such modifications and variations that may be apparent to a person skilled in the art are intended to be included within the scope of the present invention as defined by the accompanying claims.
Claims
1. A multi-cavity hot-runners control system, comprising one synchronized controller used to provide synchronized control of a plurality of hot-runners feeding multiple cavities in a same mold, each of the plurality of hot-runners including one or more heaters,
Wherein, the synchronization controller connecting to all the plurality of hot-runners, measuring all temperatures of the plurality of hot-runners simultaneously and providing synchronized control of the plurality of hot-runners based on the measured temperatures and a synchronization algorithm.
2. A multi-cavity hot-runners control system according to claim 1, wherein each of the plurality of hot-runners further including an individual controller used to control thereof;
The synchronization controller determining set point profiles for individual controllers based on measured temperatures and the synchronization algorithm; and sending determined set point profiles to corresponding individual controllers, which will accordingly control the plurality of hot-runners simultaneously based on the corresponding set point profiles, so as to provide synchronized control of the plurality of hot-runners.
3. A multi-cavity hot-rurrners control system according to claim 1, wherein the synchronization controller including:
A multi-channel temperature measurement module measuring temperatures of the plurality of hot-runners simultaneously,
A synchronization algorithm module providing control parameters for the plurality of hot-runners based on the synchronization algorithm, and
A multi-channel heater control module controlling the plurality of hot-runners simultaneously based on the control parameters for the plurality of hot-runners.
4. A multi-cavity hot-runners control system according to claim 1 , wherein the synchronized control is achieved by a predictive control and the synchronization algorithm is given based on a first cost function of the predictive control, 
Wherein, J(N11N21 N31N11) is the first cost function, JV1 can be set as a dead time of temperature, N2 can be selected as a transient time of temperature near an operating point, N3 can be set as a length of one injection cycle, N11 indicates how quickly the synchronization controller can achieve the set point, y(t -i- / 1 /) is the temperature prediction at time t + j using the information up to time t , w(/ + ./) is the set point at time t + j , Au (t + J-V) is the synchronization controller output variation at time t + j — I , y^\(t + j \ t)- yk(t + j \ t) is a difference of temperature predictions of every two adjacent hot-runners, δ(j), γ(j) and λ(j) arc weighting factors,
Wherein, by minimizing the first cost function, the temperature difference among different hot-runners can be minimized, thus can balance the flow in of the plurality of hot-runners.
5. A multi-cavity hot-runners control system according to claims 2, wherein the synchronization algorithm is given based on a second cost function,
N3 N-I N,
J(NnN21N3) = EΪ ∑ γO) ∑&kJt+j \ t)-yk(t+j \ t)) + ∑ δ(j)[y(t+j \ O-w(t+j)] i'N, k-l , - N,
Wherein, J(NnN21N3 ) is the second cost function, Nx can be set as a dead time of temperature, N2 can be selected as a transient time of temperature near an operating point, N3 can be set as a length of one injection cycle, y(t + j \ t) is the temperature prediction at time t + j using the information up to time t , w(t + /) is the set point at time t + j , yk+](t + j \ tj- yk(t + j \ t) is a difference of temperature predictions of every two adjacent hot-runners, δ(j) and γ(j) are weighting factors,
Wherein, by minimizing the second cost function, the curvature difference among set point profiles of the plurality of hot-runners can be minimized, thus can balance the flow in the plurality of hot-runners.
6. A method for providing synchronized control of multi-cavity hot-runners, comprising:
Measuring all temperatures of a plurality of hot-runners simultaneously by a synchronization controller; and
Providing synchronized control of the plurality of hot-runners based on measured temperatures and a synchronization algorithm.
7. A method according to claim 6, wherein
The step of providing synchronized control of the plurality of hot-runners based on measured temperatures and a synchronization algorithm comprising:
Determining set point profiles for the plurality of hot-runners based on the measured temperatures and the synchronization algorithm by the synchronization controller;
Sending set point profiles to corresponding individual controllers for the plurality of hot-runners by the synchronization controller; and
Controlling the temperatures of the plurality of hot-runners simultaneously based on corresponding determined set point profiles by corresponding individual controllers, so as to provide synchronized control of the plurality of hot-runners.
8. A method according to claim 6, wherein
The step of providing synchronized control of the plurality of hot-runners based on measured temperatures and a synchronization algorithm comprising:
Determining control parameters for the plurality of hot-runners based on the measured temperatures and the synchronization algorithm by the synchronization controller; and
Controlling the temperatures of the plurality of hot-runners simultaneously based on corresponding control parameters for the plurality of hot-runners by the synchronization controller, so as to provide synchronized control of the plurality of hot-runners.
9. A method according to claim 6, wherein the synchronized control is achieved by a predictive control and the synchronization algorithm is given based on a first cost function of the predictive control,
J(N11N11N31NJ 
Wherein, J(NnN31N31N11) is the first cost function, N1 can be set as a dead time of temperature, N2 can be selected as a transient time of temperature near an operating point, N3 can be set as a length of one injection cycle, Nn indicates how quickly the synchronization controller can achieve the set point, y(t + j \ t) is the temperature prediction at time t + j using the information up to time / , w(f -I- j) is the set point at time t + j , Au(t + j — ϊ) is the synchronization controller output variation at time t + j - 1 , yk+l (t + j 11) - yk (t + j 1 1) is a difference of temperature predictions of every two adjacent hot-runners, δ(j) , γ(j) and λ{j) are weighting factors,
Wherein, by minimizing the first cost function, the temperature difference among different hot-runners can be minimized, thus can balance the flow in of the plurality of hot-runners.
10. A method according to claims 7, wherein the synchronization algorithm is given based on a second cost function,
J(NμNj,N v: δθ)[y(t+j 
Wherein, J(N1, N2, N3) is the second cost function, JV1 can be set as a dead time of temperature, N1 can be selected as a transient time of temperature near an operating point, N3 can be set as a length of one injection cycle, y(l + j \ l) is the temperature prediction at time t + j using the information up to time t , w(1 -I- j) is the set point at time t + j , yM(t + j \ t) - yk(t + j \ t) is a difference of temperature predictions of every two adjacent hot-runners, δ(J) and γ(j) are weighting factors, Wherein, by minimizing the second cost function, the curvature difference among set point profiles of the plurality of hot-runners can be minimized, thus can balance the flow in the plurality of hot-runners.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102013008409A1 (en) * | 2013-05-17 | 2014-11-20 | Nolden Regelsysteme GmbH | Method and device for monitoring, controlling and / or regulating the production of plastic injection-molded parts |
| CN106610588A (en) * | 2016-12-30 | 2017-05-03 | 广东华中科技大学工业技术研究院 | Cascading prediction control system and method |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103049015A (en) * | 2012-12-20 | 2013-04-17 | 北京七星华创电子股份有限公司 | Device and method for controlling temperature of chemical liquid |
| CN109895339A (en) * | 2018-11-26 | 2019-06-18 | 苏州奥德机械有限公司 | A kind of high ray machine die temperance control system of polychrome module injection molding |
| CN110027139B (en) * | 2019-03-12 | 2021-06-22 | 湖北民族大学 | Mold preparation method, mold heating system and heating control method |
| CN110294171A (en) * | 2019-08-07 | 2019-10-01 | 深圳市血之缘医疗科技有限公司 | Multimachine cascades heat seal system |
| CN113867436B (en) * | 2021-09-17 | 2022-07-01 | 深圳市海一电器有限公司 | Intelligent cooking method and system |
| CN114311576A (en) * | 2021-11-19 | 2022-04-12 | 深圳先进技术研究院 | Temperature control system and injection molding machine |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5411686A (en) * | 1991-12-26 | 1995-05-02 | Kao Corporation | Method and apparatus for controlling injection molding |
| US6090318A (en) * | 1997-09-16 | 2000-07-18 | K.K. Holding Ag | Process for controlling the hot-runner heating of a multicavity injection mould |
| US20040113303A1 (en) * | 2001-03-14 | 2004-06-17 | Jurgen Frey | Method for automatically balancing the volumetric filling of cavities |
| CN101332657A (en) * | 2007-05-25 | 2008-12-31 | 标准模具（2007）有限公司 | Hot runner having temperature sensor for controlling nozzle heater and related method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6309571B2 (en) * | 1998-02-27 | 2001-10-30 | The Hong Kong University Of Science & Technology | Method and apparatus for the control of injection molding |
-
2010
- 2010-02-08 CN CN201080006877.1A patent/CN102333631B/en active Active
- 2010-02-08 WO PCT/CN2010/000170 patent/WO2010088844A1/en active Application Filing
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5411686A (en) * | 1991-12-26 | 1995-05-02 | Kao Corporation | Method and apparatus for controlling injection molding |
| US6090318A (en) * | 1997-09-16 | 2000-07-18 | K.K. Holding Ag | Process for controlling the hot-runner heating of a multicavity injection mould |
| US20040113303A1 (en) * | 2001-03-14 | 2004-06-17 | Jurgen Frey | Method for automatically balancing the volumetric filling of cavities |
| CN101332657A (en) * | 2007-05-25 | 2008-12-31 | 标准模具（2007）有限公司 | Hot runner having temperature sensor for controlling nozzle heater and related method |
Non-Patent Citations (1)
| Title |
|---|
| R.DUBAY.: "Self-optimizing MPC of melt temperature in injection moulding", ISA TRANSACTIONS., vol. 41, 31 January 2002 (2002-01-31), pages 81 - 94 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102013008409A1 (en) * | 2013-05-17 | 2014-11-20 | Nolden Regelsysteme GmbH | Method and device for monitoring, controlling and / or regulating the production of plastic injection-molded parts |
| DE102013008409B4 (en) * | 2013-05-17 | 2015-05-13 | Nolden Regelsysteme GmbH | Method and device for monitoring, controlling and / or regulating the production of plastic injection-molded parts |
| CN106610588A (en) * | 2016-12-30 | 2017-05-03 | 广东华中科技大学工业技术研究院 | Cascading prediction control system and method |
| CN106610588B (en) * | 2016-12-30 | 2019-11-26 | 广东华中科技大学工业技术研究院 | A kind of tandem Predictive Control System and method |
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