AT512781A4 - Method for operating energy consumers of an injection molding machine - Google Patents

Abstract

Method for operating energy consumers (1) of an injection molding machine (2), wherein each energy consumer (1) is allocated a partial energy consumption (T), for all energy consumers (1) together a maximum energy consumption (Em ax) is determined, wherein to avoid exceeding the fixed maximum energy consumption (Em ax) at a first time (ti) at least one energy consumer (1) no energy (E) is allocated, and each energy consumer (1) at the first time (ti) has a priority value (P) for energy allocation, wherein a later, second point in time (t2) the priority value (P) of each energy consumer (1) is updated as a function of the energy (E) allocated at the first time (ti).

Description

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The invention relates to a method for operating energy consumers of an injection molding machine, each energy consumer is allocated a share of energy consumption, for all energy consumers together a maximum energy consumption is set, to avoid exceeding the specified maximum energy consumption at a first time at least one energy consumer no energy is allocated, and Each energy consumer is assigned a priority value for energy allocation or has a priority value at the first time. In addition, the invention relates to an injection molding machine, in particular for carrying out a method mentioned, with at least two energy consumers, which can be supplied with energy via a power source, a control or regulating unit for allocating the power supplied by the energy source for the at least two energy consumers, each energy consumer a Priority value assigned to energy allocation or each energy consumer has a priority value, and a memory in which the priority wave at a first time, one, each energy consumer allocable, Teilergfeverbrauch and a definable maximum energy consumption of all energy consumers together can be stored, to avoid exceeding the stored Maximatenergieverbrauchs at the first time by the control or regulating unit, the power supply is at least interruptible to an energy consumer.

In such known methods or injection molding is about the limitation of the power consumption of an injection molding machine or an entire injection molding. Each energy consumer (heating, drives, etc.) can limit the energy supply. A maximum energy consumption (total limit) prevents the main connection from being exceeded.

A method for operating an injection molding machine is disclosed in WO 2011/157564. In order to obtain an increased energy efficiency in injection molding machines, a power profile for a drive is given, wherein on the basis of power requirements that operating combination of drives from the "··················································································· ························································································································································································································

Performance data is determined, which results in the performance profile. Thus, a certain performance profile of the sum of the individual drives must not be exceeded.

From DE 10 2007 059 781 it is apparent that the maximum connected load of plants must be kept as low as possible. Feedback via feedback cables results in a 30 to 50% reduction in the total connected load during the production process. It is extended by temporal displacement of the control of the heating control circuits only the heating phase of the individual control loops. The sum of the electric power supplied to the heating control circuits is thus always lower than a power setpoint. In this document, it is only about the control of heating control circuits and not other energy consumers such. Engines.

DE 196 51 484 A1 shows a method for optimizing the power consumption of a composite of electrically heated or cooled consumers of a plant in the plastics processing industry. A phase-shifted control regulates the power consumption of the consumers and the consumer network.

The generic US 7,568,905 B2 aims to reduce energy costs as much as possible. Once a total consumption exceeds a certain limit, at least one component is at least partially no longer supplied with energy ("de-energized"). This "de-energizing" reduces the peak to a lower peak. Furthermore, it is stated that the "de-energizing" of components takes place on the basis of a priority, whereby the "least important" component receives no energy.

A disadvantage of the last-mentioned document, as well as in the previous writings, is that only after a certain time or only after final supply of an important component, a component with lower priority is re-energized. So it may take a relatively long time until an "unimportant" energy consumer is supplied with energy again. Above all, that can happen to be an important one

Component prevents the energy supply of almost all other energy consumers for a long period of time.

The object of the present invention is therefore to provide a comparison with the prior art improved method or an improved injection molding machine. In particular, an energy-efficient and at the same time "fair" supply of the individual energy consumers with energy is to be guaranteed.

This is achieved by a method having the features of claim 1. According to the invention, it is accordingly provided that at a later, second point in time the priority value of each energy consumer is updated as a function of the energy allocated to the respective energy consumer at the first time. Thus, there is no absolute predetermined priority value for a particular energy consumer, but this priority value is constantly or regularly changed. The energy supply is thus no longer dependent solely on the time or external requirements, but constantly changes depending on the energy allocated at the last time or the last run to the respective energy consumer.

In principle, the energy consumer can either be assigned the priority value by a control or regulation unit, or the energy consumer himself reports his (updated) priority value to the control unit or to a higher-level control module of the control or regulation unit.

According to a preferred embodiment of the present invention, it can be provided that a lower priority value is assigned to each energy consumer to whom energy was allocated at the first time or a lower priority value is reported by the energy consumer, whereas for each energy consumer the first one does not Energy is assigned, a higher priority value is assigned or the energy consumer himself a higher priority value is reported. This ensures that the "importance" of each already supplied energy consumer ·· α ··· # · φ · · ι · · ♦ · «* 4 · 4 4 4 • · 4 ♦♦ · 44 4 4 4 · 4 4 4 4 4 4 4 4 4 4 4 44 44 444 44 4 44 4 while increasing the "importance" of a non-energized energy consumer.

In order to enable adaptation to the various production needs, it is preferably provided that the priority values are variable as a function of a phase of an injection molding cycle. Thus, when a certain phase of an injection molding cycle is reached, the priority values of all energy consumers can be set to a specific absolute value and then the priority control can be carried out again starting from this value. It can also be provided here that the maximum energy consumption changes or that the maximum energy consumption is increased or decreased at least for certain partial areas.

In principle, the times at which a recalculation of the energy supply takes place can be any time apart (for example a few seconds). In order to avoid too long a non-supply of an energy consumer, it is therefore provided that between the first time and the second time between 1 and 800 milliseconds, preferably between 3 and 20 milliseconds, more preferably 6 milliseconds lie. Thus, a recalculation is preferably carried out every six milliseconds, or the priority values of the individual energy consumers are updated every six milliseconds. The output and reprioritization can also take place in a further time frame (eg every 500 milliseconds). This can be set in the controller as a parameter.

The object of the present invention is also achieved by an injection molding machine with the features of claim 5. Accordingly, it is provided that the priority value of each energy consumer can be stored updated in the memory at a later, second point in time as a function of the energy allocated to the respective energy consumer at the first time.

Protection was also desired for an injection molding machine with at least two injection molding machines according to the invention. Μ ··················································································································································································································································

Further details and advantages of the present invention will be explained in more detail below with reference to the description of the figures with reference to the exemplary embodiments illustrated in the drawings. Show:

1 schematically an injection molding,

FIG. 2 is a flowchart of a priority update. FIG.

3 shows schematically a control module,

4 and 5 schematically a plurality of cascaded control modules,

6 shows a diagram of the limitation of the maximum energy consumption of individual energy consumers and

Fig. 7 shows the displacement of the power supply of individual consumers during a group clock time.

Fig. 1 shows a factory floor 18 with an injection molding system arranged therein consisting of at least two Sprilzgießmaschineii 2. From an external (or internal) energy source 3 energy E (in particular electrical power) is passed into the factory floor 18. The introduced energy E is distributed to the individual consumers 1 via the control unit 4. Accordingly, each energy consumer 1 receives a partial energy consumption T via the control or regulation unit 4 from the energy source 3. The priority values P, the maximum energy consumption M and the partial energy consumption T of the individual energy consumers 1 are stored in the memory 5 of the control unit 4.

The injection molding machine 2 consists of a frame 11 arranged on the fixed platen 13 and a movable platen 9. This movable platen 9 is movable via a toggle mechanism 8, said toggle mechanism 8 is movable via a driven by the drive unit 6 spindle 7. This drive unit 6, which forms an energy consumer 1, is attached to the end plate 10. On the movable platen 9 as well as on the fixed platen 13 each mold halves of a tool 12 are arranged. The heating elements arranged in or on this tool 12 form a further energy consumer 1. In addition, 44 4 * 4444 4 «· 44 • 4444 444 4 4 4 · 4 44 ·· 44 44 4 4 4 · 4 # 4 · 4 4 4 4 4 * • 444 444 4 · • 4 44 444 44 4 44 6, the injection molding machine 2 on a Piastifiziereinheit, which consists of a plasticizing cylinder 16, a plasticizing screw 15 and a drive unit 14. In this case, the drive unit 14 and the heating device arranged in or on the plasticizing cylinder 16 each form an energy consumer 1. A further energy consumer 1 forms the handling robot 17, through which injection-molded parts can be removed from the tool 12. The injection molding machine 2 can in principle also be designed as a two-plate machine.

According to FIG. 1, the control unit of the first injection molding machine 2 forms a master arithmetic unit also for the other injection molding machines 2 in the factory floor 18. Preferably, however, an unrepresented, overall computer for the entire workshop 18 is provided, which is connected to the individual , each injection molding machine 2 associated control or regulating units 4 communicates.

FIG. 2 shows the most important component of the control unit 4, namely the control module 19. This control module 19 receives from a higher-level unit {z. From memory 5 or by entering an operator) a power limit in the form of a maximum energy consumption Emax of 60 kW. The attached consumers 1 (in this case the heater for the tool 12, the heater for the plasticizing cylinder 16 and the drive unit 14) require a total of 80 kW. The priority control of the control module 19 now has the task of distributing the energy E so that no exceeding of the maximum energy consumption Emax occurs. Before the division takes place, the current priority value P is polled at time ti of each energy consumer 1. According to the example, all energy consumers 1 have the same priority P in the first pass. Such a pass corresponds to the cycle time of the system, which is usually 6 ms. Since all energy consumers 1 have the same priority value P, the energy consumers 1 are sequentially allocated the energy E until the maximum energy consumption Emax of 60 kW is reached. Therefore, only the first two energy consumers 1 are supplied with energy E at the time ti.

7

Subsequently, at time t2, the priority values P of each energy consumer 1 are updated as a function of the energy E allocated at the first time ti. Thus, the priority value P of the heating of the tool 12 is set to a lower priority value P-. The same applies to the energy consumer 1 supplied at the time ti with energy E (heating device for plasticizing cylinder 16). On the other hand, the drive unit 14 is assigned a higher priority value P + or registers with a higher priority value P +. First, therefore, at time t2, the drive unit 14 is assigned the power E of 40 kW due to the highest priority P. Since the two first energy consumers 1 again have the same priority P, only the first energy consumer 1 energy E is assigned by 20 kW, while the second energy consumer 2 due to the already reached maximum energy consumption Emax no energy E is assigned.

After this second pass, a new priority value calculation is performed at the time. Accordingly, the heater for the tool 12 is again assigned a lower priority value P-, whereby this energy consumer 1 now has the lowest priority P and no energy E assigned. The heater of the plasticizing cylinder 2 as the second energy consumer 1 is assigned a higher priority value P + at the time k, while the priority value P of the drive unit 14 decreases. Nevertheless, due to the still high priority P, this drive unit 14 is supplied with energy E of 40 kW. At time t4, in turn, the priority value P of each consumer 1 is updated as a function of the energy E allocated at the previous time k. There are basically two variants for the provision of the individual services. On the one hand, the services or the energy consumption of the individual energy consumers 1 can be measured, or the individual services are provided by inputs by a user (pure software solution). In order to record the current performance of the entire periphery (eg temperature control devices, etc.), the total power of the machine connection is used to determine the total power of the machine connection. ♦ * * • · · φ ♦ »· · ········································································ ···· > »*« «Φ ΦΦ ΦΦΦ ΦΦ Φ ΦΦ 8

Individual services deducted. A handling robot 17 is seen as periphery in this context.

FIG. 3 shows a control module 19 which can divide the energy E supplied to it independently of the attached energy consumer 1. It is irrelevant who is connected as an energy consumer 1 or how many energy consumers 1 are connected. By default, the control module 19 receives a limit of energy supplied to it. The control module 19 sends a power request L, a priority P and the partial energy consumption T actually received at the last time t. Depending on the design, the control module 19 can also transmit the higher-ranking point receives these parameters L, P and T. Just as the control module 19 receives limited energy Emax from a superordinate point, as with the arrows underneath the control module 19, limited energy Emax is passed on to the energy consumer 1 or to further control components 19.

In FIG. 4, it can therefore be seen that a higher-level energy component 19 corresponds to an injection molding machine 2. In a subordinate hierarchical level, further control components 19 are shown, which correspond to the heating device for the tool 12, the heating device for the plasticizing cylinder 16 or the drive units 6 and 14 or the drive unit for the handling robot 17.

In FIG. 5, a further control module 19, which corresponds to the factory floor 18, is again shown in a higher order. Due to the cascading or linking possibilities of the individual control modules 19, these can be nested as often as desired and thus also see other control modules 19 as energy consumers 1. The individual control modules 19 detect the required power (power requirement L), regardless of whether heater, drive unit or other control module 19. The, preferably stored in the memory 5, power requirement L is compared with the current priority P and the last allocated partial energy consumption T and then according to recalculated φφ φφ ··· «» · · »· φ φ φ * φ φ φ φ φφ ♦ ·· φ φ» «φφφφφ * Φ < I I »M *« * * 1 * 4 ΦΦΦ Φ Φ ΦΦ φφ «φφ φφ φφ 9

Priority Ρ- or Ρ + reassigned, lowered or completely interrupted. Depending on the energy consumption 1, it is not necessary - as shown in FIG. 2 - to completely interrupt the energy supply to a single energy consumer 1 if this would exceed the maximum energy consumption Emax. Rather, it could also be provided that the energy input of a single energy consumer 1 is only reduced, so that the maximum energy consumption Emax is not exceeded.

FIG. 6 shows in a diagram the maximum energy consumption Emax along a time line t. The maximum energy consumption Emax is composed of the limit E (12 + 16) required for the heaters for the tool 12 and the plasticizing cylinder 16 and the limit E (14 + 16 + 17) for the drive units 14 and 6, respectively, the handling robot 17. In the first phase PH (heating phase) is mainly a limitation of the drives while the heating is almost maximum. In contrast, in the second phase PH (production phase), an increase in the energy supply, especially to the drive units 14,16 and 17.

FIG. 7 shows how the present invention makes optimum use of energy consumption possible without exceeding a maximum energy consumption Emax. For this purpose, individual zones 1 to 4 of a heating device are shown as an example, which require between 3 and 5 kW. Normally, each individual zone 1 would require a certain heating time and a certain cooling time, depending on the predetermined or stored cycle sequence. If each zone 1 to 4 additionally receives a priority P, optimally the maximum energy consumption Emax of 10 kW can never be exceeded. At the first cycle time (time h), the zones 2 and 3 are supplied with energy E due to their highest priority P. Within a group cycle time, therefore, ideally all zones 1 to 4 are supplied, at least in the short term, with energy E. The heating of zone 4 is no longer in a continuous heating phase, but divided into several group cycle times. Also, the heating of the zone 1 is no longer at regular intervals, but depending on the given priority P. At each start of a new group clock time, the individual priorities P can be set back to the output priority. · «·· f · # · i · · · ·« · · «« «#« · * »· · * ·· ♦ ·· + · · > * «» ··· * «· ·« «·» # ft · ♦

* · I «Μ» Μ · II 10

As regards the priorities P, it is generally stated that these are preferably given as absolute values. Of course, these priorities P can also be expressed as percentages, for example of the maximum energy consumption EmaX], whereby the percentage is increased or decreased by 2% per run, for example. The updated priority values P are generally calculated within the control unit 4. This calculation can be carried out in particular by a subordinate or a higher-level control module.

The advantages of the present invention thus lie in a power specification for any number of energy consumers 1. In addition, the individual energy consumers 1 for the control or regulating unit 4 or for its control modules 19 need not be known. The number of connectable energy consumers 1 is virtually endless. In addition, nesting or cascading of the individual control modules 19 is possible. Furthermore, automation of the energy limit is integrated in each control module 19, whereby an independent distribution of the energy E provided by the energy source 3 is possible.

Innsbruck, on June 11, 2012

Claims (6)

1. A method for operating energy consumers (1) of an injection molding machine (2) in which • each energy consumer (1) is allocated a partial energy consumption (T), • a maximum energy consumption (Emax) is set for all energy consumers (1), whereby at a first time (h) in order to avoid exceeding the specified maximum energy consumption (Emax) at least one energy consumer (1) no energy (E) is allocated, and • each energy consumer (1) at the first time (h) has a priority value (P) for energy allocation, characterized in that at a later, second time (t2) the Priority value (P) of each energy consumer (1) is updated in dependence on the energy (E) allocated at the first time (ti). 2. Method according to claim 1, characterized in that, at the second time (t2), each energy consumer (1) to which energy (E) has been allocated at the first time (h) has a lower priority value (P-), whereas each energy consumer (1) 1) to which no energy (E) has been allocated at the first time (ti) has a higher priority value (P +). 3. The method according to claim 1 or 2, characterized in that the priority values (P) in response to a phase (PH) of an injection molding cycle, a group cycle time or the maximum energy consumption (Emax) are variable. 4. The method according to any one of claims 1 to 3, characterized in that between the first time (ti) and the second time (t2) between 3 and 20 milliseconds, preferably 6 milliseconds lie. 5. injection molding machine (2), in particular for carrying out a method according to one of claims 1 to 4, with: 71873 22 / eh ······································· · II * «· *« · · «4 · · · * · # ··············································································································································································································································· an energy source (3) can be supplied with energy (E), - a control or regulation unit (4) for allocating the energy (E) supplied by the energy source (3) to the at least two energy consumers (1), each energy consumer (1 ) has a priority value (P) for energy allocation, and - a memory (5) in which a. the priority values (P) at a first time (ti), b. a, each energy consumer (1) allocable, partial energy consumption (T) and c. a definable maximum energy consumption (Emax) of all energy consumers (1) is stored together, to avoid exceeding the stored maximum energy consumption (Emax) at the first time (ti) of the control or regulating unit (4), the energy supply to at least one energy consumer (1) is interruptible , characterized in that from the control unit (4) at a later, second time (t2) the priority value (P) of each energy consumer (1) as a function of the first time (ti) allocated energy (E) updated in memory (5) can be stored. 6. injection molding with at least two injection molding machines (2) according to claim 5. Innsbruck, on June 11, 2012