CA1171757A - Control device for the hydraulic circuit of an injection molding machine - Google Patents
Control device for the hydraulic circuit of an injection molding machineInfo
- Publication number
- CA1171757A CA1171757A CA000402395A CA402395A CA1171757A CA 1171757 A CA1171757 A CA 1171757A CA 000402395 A CA000402395 A CA 000402395A CA 402395 A CA402395 A CA 402395A CA 1171757 A CA1171757 A CA 1171757A
- Authority
- CA
- Canada
- Prior art keywords
- pressure
- valve system
- proportional valve
- program
- pressure gauge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- 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
- B29C45/76—Measuring, controlling or regulating
- B29C45/82—Hydraulic or pneumatic circuits
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The present invention relates to a control device for the hydraulic circulation in a plastics material injection moulding machine, with the delivery output of the variable delivery pump being adapted to the various requirements of the consumer apparatus during the working phases of a working cycle by means of a proportional valve system, the throughflow cross-section of such a valve system being adjustable by means of electrical input signals, whereby a return control or feedback line is provided which branches-off from the consumer or main supply line downstream of the proportional valve system and readjusts the delivery pump, and whereby the proportional valve system is provided in the regulating circuit with at least one position transducer, by means of which transducer an adjustment of the proportional valve system deviating from the desired value is effected to return to the predetermined desired value of the program.
The present invention relates to a control device for the hydraulic circulation in a plastics material injection moulding machine, with the delivery output of the variable delivery pump being adapted to the various requirements of the consumer apparatus during the working phases of a working cycle by means of a proportional valve system, the throughflow cross-section of such a valve system being adjustable by means of electrical input signals, whereby a return control or feedback line is provided which branches-off from the consumer or main supply line downstream of the proportional valve system and readjusts the delivery pump, and whereby the proportional valve system is provided in the regulating circuit with at least one position transducer, by means of which transducer an adjustment of the proportional valve system deviating from the desired value is effected to return to the predetermined desired value of the program.
Description
The present invention relates to a control device for the hydraulic circulation in a plastics material injec~ion moulding machine, with the delivery output of the variable delivery pump being adapted to the various require-ments of the consumer apparatus during the working phases of a working cycle by means of a proportional valve system, the throughflow cross-section of such a valve system being adjusta~le by means of electrical input signals, whereby a return con~rol or feedback line is provided which branches-off from the consumer or main supply line downstream of the proportional valve system and readjusts the delivery pump, and whereby the proportional valve system is provided in the regulating circuit with at least one position transducer, by means of which transducer an adjustment of the proportional valve system deviating from the desired value is effected to return to the predetermined desired value of the program.
In a known control device of this type (German Offenlegungsschrift 2 528 963 or equivalent ~ Patent 1,548,016~, the proportional valve system includes both a proportional quantity valve and a proportional pressure valve, and a position transducer is located in the regulating circuit of each of these valves. Such a control deyice produces a geo-metrical parameter, in that the position of the valve body o~
each proportional valve can be regulated. This results in a qualitatively precise control for the ranges, especially pressures and speeds for the consumer apparatus, whereby the energy consumption by the delivery pump is adapted to the actual ou~put requirements of the consumer apparatus at a - 1 - q mab/~ ~
117175~7 lower limit.
Based on this, the invention seeks to modify a control device of the above-mentioned type in such a manner that it can satisfy the most varied program conditions to a substantially higher degree, especially also with regard to a pressure program control device which is located directly on the consumer apparatus, and in .such a manner that, in this case, the regulating pump is operated so as to adapt to a minimal, energy requirement.
According to the present invention there is pro-vided a control device for the hydraulic circuit of a plastics material injection moulding machine, with the delivery quantity-pressure output of the variable delivery pump being adapted to the various requirements of the load during the working phases of a working cycle by means of a proportional valve system, the throughflow cross-section of such a valve system being ad~ustable by means of electrical input signals, whereby a feedback line is provided which branches-off from the main supply line downstream of the proportional valve system and read~usts the variable deliyery pump, and whereby the propor-tlonal valve system is provided in the regulating circuit with at least one position transducer by means of which transducer and ad~ustment of the proportional valve system deviating from the desired value is returnable to the predetermined desired value set by the program, characterised in that the quantity program regulation of the proportional valye system is automatically convertible to a pressure program regulation by means of a pressure gauge in accordance with at least one para~eter (path, time, pressure) for specific pressure require-
In a known control device of this type (German Offenlegungsschrift 2 528 963 or equivalent ~ Patent 1,548,016~, the proportional valve system includes both a proportional quantity valve and a proportional pressure valve, and a position transducer is located in the regulating circuit of each of these valves. Such a control deyice produces a geo-metrical parameter, in that the position of the valve body o~
each proportional valve can be regulated. This results in a qualitatively precise control for the ranges, especially pressures and speeds for the consumer apparatus, whereby the energy consumption by the delivery pump is adapted to the actual ou~put requirements of the consumer apparatus at a - 1 - q mab/~ ~
117175~7 lower limit.
Based on this, the invention seeks to modify a control device of the above-mentioned type in such a manner that it can satisfy the most varied program conditions to a substantially higher degree, especially also with regard to a pressure program control device which is located directly on the consumer apparatus, and in .such a manner that, in this case, the regulating pump is operated so as to adapt to a minimal, energy requirement.
According to the present invention there is pro-vided a control device for the hydraulic circuit of a plastics material injection moulding machine, with the delivery quantity-pressure output of the variable delivery pump being adapted to the various requirements of the load during the working phases of a working cycle by means of a proportional valve system, the throughflow cross-section of such a valve system being ad~ustable by means of electrical input signals, whereby a feedback line is provided which branches-off from the main supply line downstream of the proportional valve system and read~usts the variable deliyery pump, and whereby the propor-tlonal valve system is provided in the regulating circuit with at least one position transducer by means of which transducer and ad~ustment of the proportional valve system deviating from the desired value is returnable to the predetermined desired value set by the program, characterised in that the quantity program regulation of the proportional valye system is automatically convertible to a pressure program regulation by means of a pressure gauge in accordance with at least one para~eter (path, time, pressure) for specific pressure require-
- 2 -mab/~
1~71757 ments (e.g. subsequent pressure phase during injection or tool-securing phases in die-closure), the pressure gauge being located in the regulating circuit of the proportional valve system instead of the position transducer during the pressure program regulation; and in that the delivery pump, during quantity program regulation and during pressure program regulation, is controllable by means of the feedback line in dependence upon the pressure prevailing in a portion of the main supply downstream of the proportional valve system, the control being such that, during quantity program regulation and during pressure program regulation, there i8 a constant drop in operating pressure between the delivery pump and the said portion of the main supply line.
What is understood by a "drop in operating pressure"
(operational pressure gradient) in the above sense is such a drop which is required, howeyer, as the basis for the opera-tion and the control of the deliyery pump and lies at this lower limit.
In such an embodiment, the regulation may also be effected in direct dependence upon the pressure of the hydraulic medium. In fact, the position of the valve body in the proportional yalve system is also regulated in this case by means of a directional scanner or position transducer, which co-operates with the control magnet, to a program-controlled cross-sectional change which is repeated in the cycle. How~
ever, the output requirement of the delivery pump is now determined in dependence upon the development of pressure in the consumer line downstream of the proportional quantity valve, the feed pump having a constant, minimal feed pressure,
1~71757 ments (e.g. subsequent pressure phase during injection or tool-securing phases in die-closure), the pressure gauge being located in the regulating circuit of the proportional valve system instead of the position transducer during the pressure program regulation; and in that the delivery pump, during quantity program regulation and during pressure program regulation, is controllable by means of the feedback line in dependence upon the pressure prevailing in a portion of the main supply downstream of the proportional valve system, the control being such that, during quantity program regulation and during pressure program regulation, there i8 a constant drop in operating pressure between the delivery pump and the said portion of the main supply line.
What is understood by a "drop in operating pressure"
(operational pressure gradient) in the above sense is such a drop which is required, howeyer, as the basis for the opera-tion and the control of the deliyery pump and lies at this lower limit.
In such an embodiment, the regulation may also be effected in direct dependence upon the pressure of the hydraulic medium. In fact, the position of the valve body in the proportional yalve system is also regulated in this case by means of a directional scanner or position transducer, which co-operates with the control magnet, to a program-controlled cross-sectional change which is repeated in the cycle. How~
ever, the output requirement of the delivery pump is now determined in dependence upon the development of pressure in the consumer line downstream of the proportional quantity valve, the feed pump having a constant, minimal feed pressure,
3 -mab /t, ~,~
117~757 and this is a pre-requisite for maximum energy-saving.
The control system according to the invention also has the structural features required for a relatively simple, and hence economical construct;on; because such a system can be operated with one single proportional quantity valve at high speed.
In addition to the pressure gauge, a path or section voltage transformer may be located in the regulating circuit of the proportional valve system for various speed stages and is disposed directly on the consumer apparatus.
The invention will be described further, by way of example, with reference to the accompanying drawing, which is a diagrammatic view of the hydraulic circuit of the control device.
A control device is illustrated including a valve group 10, a pump group 11 and a group 50 having a section voltage transformer 26 for speed regulation with regard to very different speed stages - this being synonymous with a quantity program regulation~
A line 25 leads from variable delivery pump 16, which is provlded with drive motor 17 of pump section 11, to the oil ~ilter 18. A llne 30 leads from the oil filter 18 to fluid reservoir 19. A reservoir line 14 comes from the valve section 10 and discharges into the reservoir 19. The variable delivery pump which may, for example, be a radial piStOIl pump9 an axial piston pump or a radial vane type pump, is provided with a control member 20. A feedback line 22, which comes from the valve section 10, leads to the control member 20.
. - 4 -mabl ~17i'757 The valve section 10 includes a proportional quantity control valve 12 which has a high working rate and a valve portion 12a located in the consumer or ~ain supply line 13 which leads from the variable delivery pump 16 to the con sumer apparatus and has a portion 13a, located upstream of the proportional quantity flow control valve 12, and a portion 13b, located downstream of this val~e. The feedbac~ line 22 branches off from the main supply line 13 in the portion 13_, i.e. downstream of the control valve 12, in order to control the pump 16 in dependence upon the pressure in the main supply line 13.
A constrictor member 21 (attenuation diaphragm) is arranged in the feedback line 22. A pressure relief valve 15 i5 located in a bridging or connecting line 23 between the portion 13a of the main supply line 13 and the reservoir line 14. The control electromagnet 12d at the pre-control or preliminary stage 12b of the flow control valve 12 co-operates with a directionai scanner or position transducer 12c. l'he position transducer 12c is therefore located in a regulating circuit, by means of which circuit values of the proportional response flow control valve, which deviate from the desired value, are returned to the desired value. The preliminary control stage 12b may be supplied alternately by an external control oil source 27 via line 29 or by an internal control oil source which is formed by a tapping line 28 which extends from the main supply line 13 in the portion 13a.
During control of variable speed stages according to the predetermined program based on an appropria~e adjustment of the valve body of the proportional response flow control _ .~ L /i ~7175~7 valve 12 by means of the position transducer 12c via the pre-control stage 12b , the pressure in the feedback line 22 may be reduced at that particular location in the portion 13b of the main supply line 13 where the pressure gauge 24 reduces the pressure during pressure programme control.
The section voltage transformer 26 in the section 50 for regulating various speed stages, i.e. for quantity regulation has a voltage portion U.
A linear potentiometer or a rotary potentiometer may be used. for example, as a voltage transformer.
The control device may be used in numerous ways:
The adjustment or setting of the control valve 12, which is predetermined in a computer, i.e. operates according to ~rogram, constitutes the basis for the present control .
device, ~n that a quantity or pressure setting of the control valve 12, deviating from the desired value, is returnable to the desired value alternately by means of the position trans-ducer 12c, the section voltage transformer 26 or the pressure gauge 24 in the regulating circuit. The output requirements, which change continuously thereby during the working cycle of the consumer apparatus, e.g. speeds and pressures, are taken into consideration by an appropriate control of the regulating pump via the feedback line 22 in dependence upon the pressure of the main supply line 13 in the portion 13b downstrea~ of the control valve 12. The pressure gradient between the pump 16 and the main supply line 13 is always kept constant thereby in the portion 13b downstream of the flow control valve 12. The pressure difference may be, for examp7e, 11 bars. This parameter denotes alower limit at which the ~ , .
~1~1757 pump is still operational and controllable. The basis for the control is, therefore, a quantity control which, by means of the position transducer 12c, is a geometrical parameter, namely the setting of the valve body of the proportional quantity flow control valve, such adjustment occurring accor-ding to program in the injection cycle. This quantity control is superposed by a pressure program control. Depending on the requirements of the consumer apparatus, the control device is automatically switched-over from the quantity control to the pressure program control. The switch-over is effected according to predetermined criteria, e.g. according to the path covered at the consumer apparatus, or in dependence upon the time or by means of the pressure gauge 24 in dependence upon the oil pressure in the consumer line or upon a pressure gauge disposed directly on the consumer apparatus. The transition from the quantity program control to the pressure program control is effected within the range of every single crlterion if a specific signal ~ariable, which i8 predetermined in the computer, is exceeded. According to the pressure progra~, control is effected, for example~ in the subsequent pressure phase after the plastics material has been injected into the injection moulding die and during closure o~ the in-~ection moulding die in the tool securing phase. In turn~ this pressure program control can be switched-oyer to a quantity program control, disposed di~ectly on the consumer apparatus, according to a variable which is predetPrmined in the computer, and the quantity program control operates on the basis of the group 50 having a section voltage transformer for speed regulation. Accordingly, the so-called pressure program mab~
1~7175, control is a combined quantity and pressure program control whereby the proportional quantity valve is no longer directly controlled by the position transducer 12_, but, for example, by the section voltage transformer 26 or by the pressure gauge 24. In each case, however, such a subsequent readiustment of the pump 16 is ensured by means of the feedback line 22 that the pressure drop between the pump 16 and the portion 13b of the consumer line is a constant, minimal size.
In the embodiment shown in the drawing, the pressure gaùge 24, as stated above (page 5), reduces the pres-sure at that location of the consumer line 13 at which the pressure in the feedback line 22 is reduced. However, the pressure gauge 24 may also be disposed directly on the confiumer appara~us in the consumer line 13.
In many cases, it may be expedient to provide a further pressure gauge in addition to the pressure gauge 24 -this further pressure gauge reducing the pressure in the moulding cavity of the injection moulding die. This further pressure gauge is intended for this purpose and, in connection with the scope of pressure regulation, is suitable for con-trolling the pressure in the moulding cavity. It cannot, therefore, replace the pressure gauge 24, which is responsible for the o~her remaining ranges of pressure control where, for example, the operation must be carried out at maximum pressure or vhere the injection moulding die is closed at low pressure.
The further pressure gauge may be supported by a s~rew-bolt which extends through the wall of the injection moulding die. Consequently, it is capable of being easily removed from this injection moulding die and being reinsertable.
mab/~-However, the further pressure gauge may also be disposed on the rear side of an ejector pin of the injection moulding die, because this ejector pin defines the moulding cavity with its front leading edge and is, therefore, suitable for transmitting the pressure data of the moulding cavity to the pressure gauge disposed on the rear side.
The further pressure gauge is, therefore, an important component part of a regulating facility which super-poses the conventional pressure regulation by means of pressure gauge 24.
A working cycle, which is regulated by the con-trol device, operates in the following steps, e.g. starting from the opened injection moulding die:
1. The injection mouldlng die is closed. The closure move-ment required therefor may be executed at different speeds. The quantity program necessary therefor is regulated by the position transducer 12c or the section voltage transformer 26. During the clcsing movement, ~ safety path for the injection moulding die is travelled-over, in which a pressure regulation is super-posed over the speed regulation via the pressure gauge 24.
This means that, when the permissable pressure is reached which is envisaged by the program, pressure regulation occurs automatically.
2. The injection nozzle is brought to the injection moulding die this happens via a speed program with a superposed pressure program. The regulation is thereby effected via the position transducer 12c or via the pressure gauge 24.
3. The plastics material is injected into the injection moulding die~ Injection is effected via a speed program which is synonymous with a quantity program. This quantity program - .~
, is regulated via the position transducer 12c or the section voltage transformer 26. The quantity program is superposed by a pressure safety means via the pressure gauge 24. After a pressure, envisaged by the program, has been reached in the injection moulding die, there is a switch-over to a sub-sequent pressure program. This occurs via a pressure gauge ln the injection moulding die or a pressure gauge in the hydraulics, i.e. preferably in the control valve 12 or on the injection cylinder.
117~757 and this is a pre-requisite for maximum energy-saving.
The control system according to the invention also has the structural features required for a relatively simple, and hence economical construct;on; because such a system can be operated with one single proportional quantity valve at high speed.
In addition to the pressure gauge, a path or section voltage transformer may be located in the regulating circuit of the proportional valve system for various speed stages and is disposed directly on the consumer apparatus.
The invention will be described further, by way of example, with reference to the accompanying drawing, which is a diagrammatic view of the hydraulic circuit of the control device.
A control device is illustrated including a valve group 10, a pump group 11 and a group 50 having a section voltage transformer 26 for speed regulation with regard to very different speed stages - this being synonymous with a quantity program regulation~
A line 25 leads from variable delivery pump 16, which is provlded with drive motor 17 of pump section 11, to the oil ~ilter 18. A llne 30 leads from the oil filter 18 to fluid reservoir 19. A reservoir line 14 comes from the valve section 10 and discharges into the reservoir 19. The variable delivery pump which may, for example, be a radial piStOIl pump9 an axial piston pump or a radial vane type pump, is provided with a control member 20. A feedback line 22, which comes from the valve section 10, leads to the control member 20.
. - 4 -mabl ~17i'757 The valve section 10 includes a proportional quantity control valve 12 which has a high working rate and a valve portion 12a located in the consumer or ~ain supply line 13 which leads from the variable delivery pump 16 to the con sumer apparatus and has a portion 13a, located upstream of the proportional quantity flow control valve 12, and a portion 13b, located downstream of this val~e. The feedbac~ line 22 branches off from the main supply line 13 in the portion 13_, i.e. downstream of the control valve 12, in order to control the pump 16 in dependence upon the pressure in the main supply line 13.
A constrictor member 21 (attenuation diaphragm) is arranged in the feedback line 22. A pressure relief valve 15 i5 located in a bridging or connecting line 23 between the portion 13a of the main supply line 13 and the reservoir line 14. The control electromagnet 12d at the pre-control or preliminary stage 12b of the flow control valve 12 co-operates with a directionai scanner or position transducer 12c. l'he position transducer 12c is therefore located in a regulating circuit, by means of which circuit values of the proportional response flow control valve, which deviate from the desired value, are returned to the desired value. The preliminary control stage 12b may be supplied alternately by an external control oil source 27 via line 29 or by an internal control oil source which is formed by a tapping line 28 which extends from the main supply line 13 in the portion 13a.
During control of variable speed stages according to the predetermined program based on an appropria~e adjustment of the valve body of the proportional response flow control _ .~ L /i ~7175~7 valve 12 by means of the position transducer 12c via the pre-control stage 12b , the pressure in the feedback line 22 may be reduced at that particular location in the portion 13b of the main supply line 13 where the pressure gauge 24 reduces the pressure during pressure programme control.
The section voltage transformer 26 in the section 50 for regulating various speed stages, i.e. for quantity regulation has a voltage portion U.
A linear potentiometer or a rotary potentiometer may be used. for example, as a voltage transformer.
The control device may be used in numerous ways:
The adjustment or setting of the control valve 12, which is predetermined in a computer, i.e. operates according to ~rogram, constitutes the basis for the present control .
device, ~n that a quantity or pressure setting of the control valve 12, deviating from the desired value, is returnable to the desired value alternately by means of the position trans-ducer 12c, the section voltage transformer 26 or the pressure gauge 24 in the regulating circuit. The output requirements, which change continuously thereby during the working cycle of the consumer apparatus, e.g. speeds and pressures, are taken into consideration by an appropriate control of the regulating pump via the feedback line 22 in dependence upon the pressure of the main supply line 13 in the portion 13b downstrea~ of the control valve 12. The pressure gradient between the pump 16 and the main supply line 13 is always kept constant thereby in the portion 13b downstream of the flow control valve 12. The pressure difference may be, for examp7e, 11 bars. This parameter denotes alower limit at which the ~ , .
~1~1757 pump is still operational and controllable. The basis for the control is, therefore, a quantity control which, by means of the position transducer 12c, is a geometrical parameter, namely the setting of the valve body of the proportional quantity flow control valve, such adjustment occurring accor-ding to program in the injection cycle. This quantity control is superposed by a pressure program control. Depending on the requirements of the consumer apparatus, the control device is automatically switched-over from the quantity control to the pressure program control. The switch-over is effected according to predetermined criteria, e.g. according to the path covered at the consumer apparatus, or in dependence upon the time or by means of the pressure gauge 24 in dependence upon the oil pressure in the consumer line or upon a pressure gauge disposed directly on the consumer apparatus. The transition from the quantity program control to the pressure program control is effected within the range of every single crlterion if a specific signal ~ariable, which i8 predetermined in the computer, is exceeded. According to the pressure progra~, control is effected, for example~ in the subsequent pressure phase after the plastics material has been injected into the injection moulding die and during closure o~ the in-~ection moulding die in the tool securing phase. In turn~ this pressure program control can be switched-oyer to a quantity program control, disposed di~ectly on the consumer apparatus, according to a variable which is predetPrmined in the computer, and the quantity program control operates on the basis of the group 50 having a section voltage transformer for speed regulation. Accordingly, the so-called pressure program mab~
1~7175, control is a combined quantity and pressure program control whereby the proportional quantity valve is no longer directly controlled by the position transducer 12_, but, for example, by the section voltage transformer 26 or by the pressure gauge 24. In each case, however, such a subsequent readiustment of the pump 16 is ensured by means of the feedback line 22 that the pressure drop between the pump 16 and the portion 13b of the consumer line is a constant, minimal size.
In the embodiment shown in the drawing, the pressure gaùge 24, as stated above (page 5), reduces the pres-sure at that location of the consumer line 13 at which the pressure in the feedback line 22 is reduced. However, the pressure gauge 24 may also be disposed directly on the confiumer appara~us in the consumer line 13.
In many cases, it may be expedient to provide a further pressure gauge in addition to the pressure gauge 24 -this further pressure gauge reducing the pressure in the moulding cavity of the injection moulding die. This further pressure gauge is intended for this purpose and, in connection with the scope of pressure regulation, is suitable for con-trolling the pressure in the moulding cavity. It cannot, therefore, replace the pressure gauge 24, which is responsible for the o~her remaining ranges of pressure control where, for example, the operation must be carried out at maximum pressure or vhere the injection moulding die is closed at low pressure.
The further pressure gauge may be supported by a s~rew-bolt which extends through the wall of the injection moulding die. Consequently, it is capable of being easily removed from this injection moulding die and being reinsertable.
mab/~-However, the further pressure gauge may also be disposed on the rear side of an ejector pin of the injection moulding die, because this ejector pin defines the moulding cavity with its front leading edge and is, therefore, suitable for transmitting the pressure data of the moulding cavity to the pressure gauge disposed on the rear side.
The further pressure gauge is, therefore, an important component part of a regulating facility which super-poses the conventional pressure regulation by means of pressure gauge 24.
A working cycle, which is regulated by the con-trol device, operates in the following steps, e.g. starting from the opened injection moulding die:
1. The injection mouldlng die is closed. The closure move-ment required therefor may be executed at different speeds. The quantity program necessary therefor is regulated by the position transducer 12c or the section voltage transformer 26. During the clcsing movement, ~ safety path for the injection moulding die is travelled-over, in which a pressure regulation is super-posed over the speed regulation via the pressure gauge 24.
This means that, when the permissable pressure is reached which is envisaged by the program, pressure regulation occurs automatically.
2. The injection nozzle is brought to the injection moulding die this happens via a speed program with a superposed pressure program. The regulation is thereby effected via the position transducer 12c or via the pressure gauge 24.
3. The plastics material is injected into the injection moulding die~ Injection is effected via a speed program which is synonymous with a quantity program. This quantity program - .~
, is regulated via the position transducer 12c or the section voltage transformer 26. The quantity program is superposed by a pressure safety means via the pressure gauge 24. After a pressure, envisaged by the program, has been reached in the injection moulding die, there is a switch-over to a sub-sequent pressure program. This occurs via a pressure gauge ln the injection moulding die or a pressure gauge in the hydraulics, i.e. preferably in the control valve 12 or on the injection cylinder.
4. The plastics material is plasticised, by means of the plasticising worm, into plasticising cylinders (injection cylinders) via a speed program. In this case, the drive of the plasticising ~orm is effected via a hydraulic motor.
The quantity program regulation which is required therefore occurs yia the directional scanner 12c or via the section voltage transformer 26.
The quantity program regulation which is required therefore occurs yia the directional scanner 12c or via the section voltage transformer 26.
5. Subsequently, the injection nozzle is detached from the injection moulding die via a speed program (quantity progrem).
6. The injection moulding die is then opened. The opening moyement required therefor may be executed at different speeds.
The quantity program required therefor is regulated via the posi-tion transducer 12c or via the section voltage transformer 26.
The quantity program required therefor is regulated via the posi-tion transducer 12c or via the section voltage transformer 26.
7. The finlshed moulding is ejected. During forward movement and during backward moyement, the hydraulic ejector is controlled by a speed program haying a superimposed printed program. The regulation is thereby effected via the position transducer 12c or via the section voltage transformer 26 and the pressure gauge 24.
~abl
~abl
Claims (14)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A control device for the hydraulic circuit of a plastics material injection moulding machine said device including a variable delivery pump having a delivery quantity-pressure output through a main supply line adaptable to the various requirements of the load during the working phases of the working cycle of the machine by means of a proportional valve system wherein the through-flow cross-section of said valve system is adjustable by means of electrical input signals, whereby a feedback line is provided which branches-off from the main supply line downstream of the proportional valve system for readjustment of the variable delivery pump, and whereby the proportional valve system has a regulating circuit which is provided with at least one position transducer by means of which transducer an adjustment of the proportional valve system deviating from the desired value is effected to return to the predetermined desired value set by the program, characterised in that the quantity program regulation of the proportional valve system is automatically convertible to a pressure program regulation by means of a pressure gauge in accordance with at least one parameter (path, time, pressure) for specific pressure requirements, the pressure gauge being locatable in the regulating circuit of the proportional -valve system instead of the position transducer during the pressure program regulation; and in that the delivery pump, during quantity program regulation and during pressure program regulation, is controllable by means of the feedback line in dependence upon the pressure prevailing in a portion of the main supply downstream of the proportional valve system, the control being such that, during quantity program regulation and during pressure program regulation, there is a constant drop in operating pressure between the delivery pump and the said portion of the main supply line.
2. A device as claimed in claim 1, in which the proportional valve system is formed by a single proportional quantity valve having a high operating speed.
3. A device as claimed in claim 1 or 2 in which in addition to the pressure gauge, there is a voltage trans-former located in the regulating circuit of the proportional valve system for various speed stages, and said transformer is mounted directly on the consumer portion of the machine.
4. A device as claimed in claim 1, in which the position transducer or a voltage transformer can be alternately connected into the regulating circuit of the proportional valve system for the quantity program regulation which serves to achieve various speed rates in the consumer portion of the machine.
5. A device as claimed in claim 1 in which the signal variables, which are required within each parameter and trigger the change-over from the quantity program regula-tion to pressure program regulation, are predetermined for a specific working cycle in the computer.
6. A device as claimed in claim 1, wherein a constrictor member is inserted in the feedback line.
7. A device as claimed in claim 1 wherein the constant pressure difference between the regulating pump and the said portion of the consumer line is between 8 - 14 bars.
8. A device as claimed in claim 1, wherein the proportional valve system is selectively fed by an internal control oil source or an external control oil source.
9. A device as claimed in claim 1, in which the pressure relief valve is introduced into the main supply line in a portion upstream of the proportional quantity valve.
10. A device as claimed in claim 1, in which the pressure in the control feedback line is reduced during the quantity program regulation and the pressure in the pressure gauge is reduced during the pressure program regulation at the same location in the main supply line.
11. A device as claimed in claim 1, in which the pressure gauge is disposed directly on the consumer apparatus in the main supply line.
12. A device as claimed in claim l, in which in addition to the pressure gauge, a further pressure gauge is provided which reduces the pressure in the moulding cavity of the injection moulding die.
13. A device as claimed in claim 12, in which further pressure gauge is supported by a screw-bolt which extends through the wall of the injection moulding die.
14. A device as claimed in claim 12, in which further pressure gauge is disposed on an ejector pin of the injection moulding die.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3119095.2 | 1981-05-14 | ||
| DE3119095A DE3119095C2 (en) | 1981-05-14 | 1981-05-14 | Control device for the hydraulic circuit of a plastic injection molding machine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1171757A true CA1171757A (en) | 1984-07-31 |
Family
ID=6132240
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000402395A Expired CA1171757A (en) | 1981-05-14 | 1982-05-06 | Control device for the hydraulic circuit of an injection molding machine |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS57195633A (en) |
| AT (1) | AT376170B (en) |
| CA (1) | CA1171757A (en) |
| CH (1) | CH659427A5 (en) |
| DE (1) | DE3119095C2 (en) |
| FR (1) | FR2506041B1 (en) |
| GB (1) | GB2099610B (en) |
| IT (1) | IT1200573B (en) |
| NL (1) | NL8200963A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4712991A (en) * | 1984-12-28 | 1987-12-15 | Karl Hehl | Hydraulic control system for injection unit of injection molding machine |
| US4846664A (en) * | 1986-12-23 | 1989-07-11 | Karl Hehl | Hydraulic system for the mold clamping unit of a plastics injection molding machine |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3309964C2 (en) * | 1983-03-19 | 1985-05-23 | Krauss-Maffei AG, 8000 München | Device for dosing and mixing two or more flowable plastic reaction components |
| DE3447709C1 (en) * | 1984-12-28 | 1986-04-30 | Karl 7298 Loßburg Hehl | Control device for the hydraulic circuit of a plastic injection molding machine |
| DE3448047A1 (en) * | 1984-12-28 | 1986-07-03 | Karl 7298 Loßburg Hehl | Hydraulic device for the injection unit of a plastics injection moulding machine |
| US5634334A (en) * | 1992-10-14 | 1997-06-03 | Hehl; Karl | Hydraulic device for use in a production machine |
| DE4234647C1 (en) * | 1992-10-14 | 1994-01-27 | Karl Hehl | Hydraulic device on an injection molding machine for processing plastics or the like |
| DE4335403C1 (en) * | 1993-10-18 | 1994-12-15 | Karl Hehl | Hydraulic device |
| US5645775A (en) * | 1995-10-04 | 1997-07-08 | Barber-Colman Company | Adaptive controller for injection molding |
| DE19603251C1 (en) * | 1996-01-30 | 1997-01-30 | Battenfeld Gmbh | Method and device for operating the hydraulic operating system of a plastics processing machine |
| JP4510992B2 (en) * | 2000-05-10 | 2010-07-28 | 川崎油工株式会社 | Control method of press hydraulic power source |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1539204A (en) * | 1967-08-03 | 1968-09-13 | Plastimonde | Improvements to the plastic molding process by adjusting the control of the movement of the mold and the injection piston |
| GB1398275A (en) * | 1971-12-28 | 1975-06-18 | British Industrial Plastics | Injection moulding machines |
| US3924840A (en) * | 1972-09-18 | 1975-12-09 | Gen Electric | Viscosity control for a plastic molding machine |
| CH554741A (en) * | 1973-02-07 | 1974-10-15 | Netstal Ag Maschf Giesserei | PLASTIC INJECTION MOLDING MACHINE WITH PROGRAMMING DEVICE. |
| JPS51144881A (en) * | 1975-06-05 | 1976-12-13 | Daikin Ind Ltd | Fluid system |
| DE2528963C2 (en) * | 1975-06-28 | 1983-11-03 | Karl 7298 Loßburg Hehl | Control device for the hydraulic circuit of an injection molding machine |
| DE2532429C3 (en) * | 1975-07-19 | 1981-12-17 | G. Bauknecht Gmbh, 7000 Stuttgart | Method and device for injection molding a plastic compound with variable injection speed |
| JPS5356479A (en) * | 1976-11-01 | 1978-05-22 | Daikin Ind Ltd | Fluid control device |
| JPS6027841B2 (en) * | 1977-12-08 | 1985-07-01 | ダイキン工業株式会社 | fluid control device |
| JPS5483964A (en) * | 1977-12-16 | 1979-07-04 | Hitachi Ltd | Injection speed pattern control device for injection molding machine |
-
1981
- 1981-05-14 DE DE3119095A patent/DE3119095C2/en not_active Expired
-
1982
- 1982-03-09 NL NL8200963A patent/NL8200963A/en not_active Application Discontinuation
- 1982-03-22 IT IT20316/82A patent/IT1200573B/en active
- 1982-03-31 GB GB8209559A patent/GB2099610B/en not_active Expired
- 1982-04-16 FR FR8206624A patent/FR2506041B1/en not_active Expired
- 1982-04-22 AT AT0157682A patent/AT376170B/en not_active IP Right Cessation
- 1982-04-28 CH CH2675/82A patent/CH659427A5/en not_active IP Right Cessation
- 1982-05-06 CA CA000402395A patent/CA1171757A/en not_active Expired
- 1982-05-13 JP JP57079293A patent/JPS57195633A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4712991A (en) * | 1984-12-28 | 1987-12-15 | Karl Hehl | Hydraulic control system for injection unit of injection molding machine |
| US4846664A (en) * | 1986-12-23 | 1989-07-11 | Karl Hehl | Hydraulic system for the mold clamping unit of a plastics injection molding machine |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2506041A1 (en) | 1982-11-19 |
| DE3119095A1 (en) | 1982-12-02 |
| NL8200963A (en) | 1982-12-01 |
| IT8220316A0 (en) | 1982-03-22 |
| AT376170B (en) | 1984-10-25 |
| DE3119095C2 (en) | 1983-09-01 |
| ATA157682A (en) | 1984-03-15 |
| GB2099610A (en) | 1982-12-08 |
| IT1200573B (en) | 1989-01-27 |
| FR2506041B1 (en) | 1985-12-06 |
| JPS57195633A (en) | 1982-12-01 |
| GB2099610B (en) | 1986-04-09 |
| CH659427A5 (en) | 1987-01-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1171757A (en) | Control device for the hydraulic circuit of an injection molding machine | |
| EP0649722B1 (en) | Hydraulic device | |
| GB1449728A (en) | Injection moulding | |
| JPH10669A (en) | Feedback controller for injection molding machine | |
| US4023466A (en) | Apparatus for regulating the speed of and the pressure of fluid upon the ram in the injection assembly of an injection molding machine | |
| CA1247981A (en) | Hydraulic control circuit for an injection molding machine with two loads driven by a pump | |
| US5299626A (en) | Method of and apparatus for injection speed control in die-casting machine | |
| US5688535A (en) | Drive control apparatus for an injection molding machine | |
| US5957192A (en) | Method for controlling injection in a die casting machine and apparatus for the same | |
| US4222725A (en) | Electro-hydraulic ram control apparatus | |
| US5443782A (en) | Method of shortening a rising time of each injection-molding operation in association with controlling of injection-molding speed | |
| US4215543A (en) | Method and apparatus for linear and nonlinear control of a hydraulic press | |
| US4744743A (en) | Means for pressure and quantity control of the hydraulic drives of an injection moulding machine | |
| EP0135655A1 (en) | Hydraulic control for extruder-injection machines for processing rubber | |
| JP3055441B2 (en) | Control method of injection molding machine | |
| CN114311575A (en) | Injection molding machine backpressure control device and method based on double closed-loop PID regulation | |
| EP0163884B2 (en) | Hydraulic control device for the injection unit of a plastic injection-moulding machine | |
| GB1490637A (en) | Device for hydraulically controlling injecting holding and filling pressures in injection moulding machines | |
| JP2001001380A (en) | Method for controlling injection of injection molding machine | |
| JPH021522Y2 (en) | ||
| JPH0525870Y2 (en) | ||
| JPS62189131A (en) | Controller for injection molding machine | |
| JP2564237B2 (en) | Control method of injection molding machine | |
| JPH0796541A (en) | Energy - saving injection molding machine | |
| JPH0222263Y2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEC | Expiry (correction) | ||
| MKEX | Expiry |