CN116619712A

CN116619712A - Shaft positioning system of injection molding machine and control method thereof

Info

Publication number: CN116619712A
Application number: CN202310869574.1A
Authority: CN
Inventors: 李弘臻; 赖广龙; 李斌礼; 方忠宝
Original assignee: Guangdong Yizumi High Speed Packaging System Co ltd
Current assignee: Guangdong Yizumi Precision Injection Technology Co ltd
Priority date: 2023-07-17
Filing date: 2023-07-17
Publication date: 2023-08-22
Anticipated expiration: 2043-07-17
Also published as: CN116619712B

Abstract

The invention relates to the technical field of hydraulic shafts, and discloses a shaft positioning system of an injection molding machine and a control method thereof.

Description

Shaft positioning system of injection molding machine and control method thereof

Technical Field

The invention relates to the technical field of hydraulic shafts, in particular to a shaft positioning system of an injection molding machine and a control method of the shaft positioning system.

Background

In the prior art, in the process of positioning the hydraulic shaft of the injection molding machine, on one hand, a motion control algorithm of the hydraulic shaft needs to be debugged, but the motion control algorithm of the hydraulic shaft is complex, a debugging method is high in threshold, common technicians are difficult to use, system performance is difficult to develop, and in the process of positioning the injection molding machine with different weight information, the adopted motion control algorithm is different, so that the difficulty in debugging the positioning of the hydraulic shaft is further improved, on the other hand, when the positioning precision requirement of the hydraulic shaft is high, the high-performance proportional valve/servo valve and the special motion controller are basically adopted for realizing the motion control of the shaft in a configuration mode, so that the positioning precision and the circulation cycle time requirement are realized, but the high-precision proportional valve/servo valve and the special motion controller often need larger input cost, and the competitiveness of equipment is reduced.

Disclosure of Invention

The embodiment of the invention provides a shaft positioning system of an injection molding machine and a control method thereof, wherein a driving shaft is positioned according to displacement offset through a second positioning control function and a third positioning control function corresponding to current weight information, the debugging process is simple and convenient, and the positioning efficiency and the positioning precision are improved.

In a first aspect, an embodiment of the present invention provides a shaft positioning system of an injection molding machine, including a driving shaft module, a displacement detection module, a control module, a driving module, and a driving direction control module;

the driving shaft module comprises a driving shaft and a hollow structure, and the displacement detection module is connected with the driving shaft and is used for detecting the current position of the driving shaft; the control module is connected with the displacement detection module and is used for determining displacement offset according to the current position and the target position;

the control module is used for generating a first preset coefficient relation and a second preset coefficient relation according to the current weight information of the injection molding machine, determining a second positioning control function according to a first positioning control function and the first preset coefficient relation, determining a third positioning control function according to the first positioning control function and the second preset coefficient relation, outputting a first control signal according to the second positioning control function and the displacement offset, and outputting a second control signal according to the third positioning control function and the displacement offset;

the driving module is connected with the control module and is used for outputting flow according to the first control signal so as to provide driving force for the driving shaft module;

The driving direction control module is connected with the control module and is respectively communicated with the driving module and the driving shaft module; and the opening size and the direction of the driving direction control module are adjusted according to the second control signal, so that the driving force is transmitted to the driving shaft module through the driving direction control module, and the driving shaft is controlled to move along the extending direction of the hollow structure to perform shaft positioning.

Optionally, the first positioning control function is:

wherein S (x) represents a control signal output by the first positioning control function, and A, B, C and D represent coefficients of the first positioning control function;

the control module is used for adjusting the sizes of A, B, C and D through the current weight information to obtain a first preset coefficient relation and a second preset coefficient relation corresponding to the current weight information; x is the displacement offset of the drive shaft;

the control module is further configured to output a preset maximum signal when the control signal output by the first positioning control function is greater than the preset maximum signal; and outputting a preset minimum signal when the control signal output by the first positioning control function is smaller than the preset minimum signal.

Optionally, the control module is further configured to output a third control signal according to a fourth positioning control function after the shaft positioning system is adjusted according to the second positioning control function and the third positioning control function, so as to adjust the driving module; and outputting a fourth control signal according to a fifth positioning control function to adjust the driving direction control module.

Optionally, the fourth positioning control function is:

wherein f (x) is a control signal output by the fourth positioning control function, E is a weight coefficient of the fourth positioning control function, and V is a signal output value of the preset flow of the driving module;

the fifth positioning control function is:

wherein g (x) is a control signal output by the fifth positioning control function, P is a weight coefficient of the fifth positioning control function, and Q is an opening preset signal output value of the driving direction control module; the sum of the weight coefficient of the fifth positioning control function and the weight coefficient of the fourth positioning control function is equal to 1.

Optionally, the driving direction control module comprises a proportional direction valve; the control end of the proportional direction valve is connected with the control module, the first end of the proportional direction valve is communicated with the driving module, the second end of the proportional direction valve is communicated with the first side of the hollow structure, the third end of the proportional direction valve is communicated with the second side of the hollow structure, and the fourth end of the proportional direction valve is communicated with the oil tank; the proportional direction valve is used for controlling the opening size of the proportional direction valve and controlling the first end of the proportional direction valve to be communicated with the second end of the proportional direction valve or controlling the first end of the proportional direction valve to be communicated with the third end of the proportional direction valve according to the second control signal.

Optionally, the shaft positioning system further comprises a pressure detection module, the driving module comprises an oil pump, a servo motor and an oil tank, the oil pump is electrically connected with the servo motor, a first end of the oil pump is communicated with the oil tank, and a second end of the oil pump is communicated with the driving direction control module;

the pressure detection module is arranged on the oil pump and is used for detecting a current flow signal of the oil pump, the control module is electrically connected with the pressure detection module and is used for comparing the current flow signal with the first control signal to generate a fifth control signal and outputting the fifth control signal to the driving module so that the driving module controls the output flow of the oil pump according to the fifth control signal.

In a second aspect, an embodiment of the present invention further provides a control method of a shaft positioning system, which is applied to the shaft positioning system of any of the injection molding machines, where the control method includes:

acquiring current weight information of an injection molding machine, determining a first preset coefficient relation and a second preset coefficient relation according to the current weight information, determining a second positioning control function according to the first positioning control function and the first preset coefficient relation, and determining a third positioning control function according to the first positioning control function and the second preset coefficient relation;

Acquiring the current position of a driving shaft, and obtaining a displacement offset according to the difference value between the current position and a target position;

outputting a first control signal to a driving module according to the second positioning control function and the displacement offset, so that the driving module outputs flow according to the first control signal to provide driving force for the driving shaft module; and outputting a second control signal to a driving direction control module according to the third positioning control function and the displacement offset, so that the driving direction control module adjusts the opening size and the opening direction of the driving direction control module according to the second control signal, and the driving force is transmitted to the driving shaft module through the driving direction control module to control the driving shaft to move along the extending direction of the hollow structure for shaft positioning.

the outputting a first control signal to a driving module according to the second positioning control function and the displacement offset, so that the driving module outputs a flow according to the first control signal to provide a driving force for the driving shaft module, including: acquiring a current flow signal of an oil pump;

Comparing the current flow signal with the first control signal, and outputting a fifth control signal to a driving module so that the driving module outputs flow according to the fifth control signal.

Optionally, outputting a first control signal to a driving module according to the second positioning control function and the displacement offset, so that the driving module outputs a flow according to the first control signal to provide driving force for the driving shaft module; outputting a second control signal to a driving direction control module according to the third positioning control function and the displacement offset, so that the driving direction control module adjusts the opening size and direction of the driving direction control module according to the second control signal, so that the driving force is transmitted to the driving shaft module through the driving direction control module, and after the driving shaft is controlled to move along the extending direction of the hollow structure to perform shaft positioning, the driving device further comprises:

outputting a third control signal to the driving module according to a fourth positioning control function, so that the driving module controls the flow output of the driving module according to the third control signal;

and outputting a fourth control signal to the driving direction control module according to a fifth positioning control function, so that the driving direction control module adjusts the opening size and direction of the driving direction control module according to the fourth control signal.

Optionally, the driving direction control module comprises a proportional direction valve;

outputting a third control signal to the driving module according to the fourth positioning control function, so that the driving module controls the flow output of the driving module according to the third control signal; according to the fifth positioning control function, a fourth control signal is output to the driving direction control module, so that before the driving direction control module adjusts the opening size and direction of the driving direction control module according to the fourth control signal, the method further comprises:

and adjusting the proportional directional valve according to the precision requirement of the fifth positioning control function.

The shaft positioning system of the injection molding machine comprises a driving shaft module, a displacement detection module, a control module, a driving module and a driving direction control module. The driving shaft module comprises a driving shaft and a hollow structure, the displacement detection module is connected with the driving shaft and used for detecting the current position of the driving shaft, and the control module is connected with the displacement detection module and used for determining displacement offset according to the current position and the target position. The control module is used for generating a first preset coefficient relation and a second preset coefficient relation according to the current weight information of the injection molding machine, determining a second positioning control function according to the first positioning control function and the first preset coefficient relation, determining a third positioning control function according to the first positioning control function and the second preset coefficient relation, outputting a first control signal according to the second positioning control function and the displacement offset, and outputting a second control signal according to the third positioning control function and the displacement offset. The driving module is connected with the control module and is used for outputting flow according to the first control signal so as to provide driving force for the driving shaft module. The driving direction control module is connected with the control module and is respectively communicated with the driving module and the driving shaft module and is used for adjusting the opening size and the direction of the driving direction control module according to a second control signal so that driving force is transmitted to the driving shaft module through the driving direction control module to control the driving shaft to move along the extending direction of the hollow structure for shaft positioning. Therefore, when different injection molding machines are debugged, only the second positioning control function and the third positioning control function corresponding to the current weight information are obtained according to the current weight information of the injection molding machine and the first positioning control function preset in the control module, and the control module performs shaft positioning according to the first control signal output by the second positioning control function and the displacement offset and the second control signal output by the third positioning control function and the displacement offset, so that the debugging process is simple and convenient, the positioning efficiency and the positioning precision of the shaft positioning system are improved, and the cost is reduced.

Drawings

FIG. 1 is a schematic diagram of a shaft positioning system for an injection molding machine according to an embodiment of the present invention;

FIG. 2 is a graph of an output signal provided by an embodiment of the present invention;

FIG. 3 is a flow chart of a method of controlling a shaft positioning system according to an embodiment of the present invention;

FIG. 4 is a flow chart of another method of controlling a shaft positioning system provided by an embodiment of the present invention;

fig. 5 is a graph of spool flow for a proportional directional valve according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be fully described below by way of specific embodiments with reference to the accompanying drawings in the examples of the present invention. It is apparent that the described embodiments are some, but not all, embodiments of the present invention, and that all other embodiments, which a person of ordinary skill in the art would obtain without making inventive efforts, are within the scope of this invention.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Fig. 1 is a schematic diagram of a shaft positioning system of an injection molding machine according to an embodiment of the present invention, and fig. 2 is a graph of an output signal according to an embodiment of the present invention, as shown in fig. 1 and 2, the shaft positioning system includes a driving shaft module 10, a displacement detection module 20, a control module 30, a driving module 40, and a driving direction control module 50. The driving shaft module 10 includes a driving shaft 110 and a hollow structure 120, the displacement detection module 20 is connected to the driving shaft 110 for detecting a current position of the driving shaft 110, and the control module 30 is connected to the displacement detection module 20 for determining a displacement offset according to the current position and the target position. The control module 30 is configured to generate a first preset coefficient relation and a second preset coefficient relation according to current weight information of the injection molding machine, determine a second positioning control function according to the first positioning control function and the first preset coefficient relation, determine a third positioning control function according to the first positioning control function and the second preset coefficient relation, output a first control signal according to the second positioning control function and a displacement offset, and output a second control signal according to the third positioning control function and the displacement offset, wherein the first positioning control function includes a curve relation of the displacement offset. The driving module 40 is connected to the control module 30 for outputting a flow rate according to the first control signal to provide a driving force to the driving shaft module 10. The driving direction control module 50 is connected with the control module 30 and is respectively communicated with the driving module 40 and the driving shaft module 10, and is used for adjusting the opening size and the direction of the driving direction control module 50 according to the second control signal, so that the driving force is transmitted to the driving shaft module 10 through the driving direction control module 50, and the driving shaft 110 is controlled to move along the extending direction of the hollow structure 120 for shaft positioning.

Specifically, as shown in fig. 1, the displacement detection module 20 is connected to the driving shaft 110 in the driving shaft module 10, and when the driving shaft 110 moves in the hollow structure 120 in the extending direction of the hollow structure 120, the change of the position of the driving shaft 110 can be detected by the displacement detection module 20, so as to obtain the current position of the driving shaft 110. The control module 30 is provided with a target position when the shaft positioning system performs shaft positioning, the control module 30 is electrically connected with the displacement detection module 20, and then the control module 30 compares the current position with the target position after detecting the current position of the driving shaft 110, and the difference value between the target position and the current position is the displacement offset of the shaft positioning system.

The corresponding relation between the current weight information and a plurality of groups of first preset coefficient relation and second preset coefficient relation is set in the control module 30, and when the current weight information of the injection molding machine is confirmed, the first preset coefficient relation and the second preset coefficient relation corresponding to the current weight information can be obtained. In addition, a first positioning control function is further built in the control module 30, the first positioning control function includes a curve relationship of displacement offset, coefficients of the first positioning control function are uncertain, and after a corresponding first preset coefficient relationship and a corresponding second preset coefficient relationship are obtained according to current weight information, the first preset coefficient relationship is substituted into the first positioning control function to obtain a second positioning control function, and the second positioning control function is used for controlling the driving module 40, wherein the second positioning control function includes a curve relationship of displacement offset with the driving shaft 110; similarly, substituting the second preset coefficient relationship into the first positioning control function to obtain a third positioning control function, where the third positioning control function is used to control the driving direction control module 50, and the third positioning control function includes a curve relationship with the displacement offset of the driving shaft 110.

Specifically, the current weight information may be tonnage information of an injection molding machine, when the injection molding machines with different tonnages perform shaft positioning, the corresponding second positioning control function and third positioning control function are different, according to tonnage information of the injection molding machine, a first preset coefficient relation and a second preset coefficient relation corresponding to the tonnage information are determined, and the first preset coefficient relation and the second preset coefficient relation are respectively substituted into the first positioning control function to obtain the second positioning control function and the third positioning control function corresponding to the tonnage information. In addition, in other embodiments, the current weight information of the injection molding machine may also be model information of the injection molding machine, when the injection molding machines with different models perform shaft positioning, the corresponding second positioning control function and third positioning control function are also different, a first preset coefficient relation and a second preset coefficient relation corresponding to the model information are determined according to the model information of the injection molding machine, and the first preset coefficient relation and the second preset coefficient relation are respectively substituted into the first positioning control function to obtain the second positioning control function and the third positioning control function corresponding to the model information. Further, the control module 30 outputs a first control signal according to the displacement offset of the driving shaft 110 and the second positioning control function, and outputs a second control signal according to the displacement offset of the driving shaft 110 and the third positioning control function after determining the second positioning control function and the third positioning control function according to the current weight information of the injection molding machine and the first positioning control function. Since the position of the driving shaft is changed in real time during the shaft positioning process, the displacement offset of the driving shaft 110 is also changed in real time, and the control module 30 outputs a plurality of sets of first control signals and second control signals according to the displacement offset of the driving shaft 110, the second positioning control function and the third positioning control function, and is controlled in real time according to the plurality of sets of first control signals and second control signals. As shown in fig. 2, the control signal is at the maximum power output (100%) before the point a, the first control signal is outputted through the second positioning control function to control the driving module 40 at the point a, and the second control signal is outputted through the third positioning control function to control the driving direction control module 50 at the point B.

Note that, the solid line in fig. 2 represents that the control is performed by the normal control signal before the first control signal and the second control signal are outputted by the second positioning control function and the third positioning control function for control.

The control module 30 is further electrically connected to the driving module 40, so that the control module 30 transmits a first control signal output according to the displacement offset of the driving shaft 110 and the second positioning control function to the driving module 40, and the driving module 40 outputs a flow according to the first control signal, and provides a driving force for the movement of the driving shaft 110 in the driving shaft module 10 through the output flow.

The drive direction control module 50 communicates the drive module 40 with the drive shaft module 10. In addition, the driving direction control module 50 is further electrically connected to the control module 30, so that the control module 30 transmits a second control signal output according to the displacement offset of the driving shaft 110 and the third positioning control function to the driving direction control module 50, and the driving direction control module 50 controls the opening size and the conducting direction thereof according to the second control signal, so that the driving force provided by the driving module 40 is transmitted to one side of the hollow structure 120 through the driving direction control module 50, and further controls the driving shaft 110 in the hollow structure 120 to advance left or retract right along the extending direction of the hollow structure 120, so as to control the driving shaft 110 to gradually reach the target position, and perform shaft positioning. Therefore, complex control algorithms are not required to be set for debugging respectively for different injection molding machines, and the shaft positioning can be performed only according to the corresponding second positioning control function and third positioning control function, so that the debugging difficulty is reduced, the debugging process is simple and convenient, the positioning efficiency and the positioning precision of the shaft positioning system are improved, and the cost of the shaft positioning system is reduced because a high-precision proportional valve/servo valve and a special motion controller are not required to be adopted.

In summary, the shaft positioning system of the injection molding machine in the invention comprises a driving shaft module, a displacement detection module, a control module, a driving module and a driving direction control module. The driving shaft module comprises a driving shaft and a hollow structure, the displacement detection module is connected with the driving shaft and used for detecting the current position of the driving shaft, and the control module is connected with the displacement detection module and used for determining displacement offset according to the current position and the target position. The control module is used for generating a first preset coefficient relation and a second preset coefficient relation according to the current weight information of the injection molding machine, determining a second positioning control function according to the first positioning control function and the first preset coefficient relation, determining a third positioning control function according to the first positioning control function and the second preset coefficient relation, outputting a first control signal according to the second positioning control function and the displacement offset, and outputting a second control signal according to the third positioning control function and the displacement offset. The driving module is connected with the control module and is used for outputting flow according to the first control signal so as to provide driving force for the driving shaft module. The driving direction control module is connected with the control module and is respectively communicated with the driving module and the driving shaft module and is used for adjusting the opening size and the direction of the driving direction control module according to a second control signal so that driving force is transmitted to the driving shaft module through the driving direction control module to control the driving shaft to move along the extending direction of the hollow structure for shaft positioning. Therefore, when different injection molding machines are debugged, the second positioning control function and the third positioning control function corresponding to the current weight information are obtained only according to the current weight information of the injection molding machine and the first control function preset in the control module, and the control module performs shaft positioning according to the first control signal output by the second positioning control function and the displacement offset and the second control signal output by the third positioning control function and the displacement offset, so that the debugging process is simple and convenient, the positioning efficiency and the positioning precision of the shaft positioning system are improved, and the cost is reduced.

Optionally, with continued reference to fig. 1, based on the above embodiment, the first positioning control function is:

where S (x) represents a control signal output from the first positioning control function, and A, B, C and D represent coefficients of the first positioning control function. The control module 30 is configured to adjust the magnitudes of A, B, C and D according to the current weight information, so as to obtain a first preset coefficient relationship and a second preset coefficient relationship corresponding to the current weight information. x is the displacement offset of drive shaft 110. The control module is also used for outputting a preset maximum signal when the control signal output by the first positioning control function is greater than the preset maximum signal; and outputting a preset minimum signal when the control signal output by the first positioning control function is smaller than the preset minimum signal.

Specifically, the control module 30 is preset with a one-to-one correspondence between a plurality of sets of current weight information and a plurality of sets of numerical values of A, B, C and D (i.e., a plurality of sets of first preset coefficient relationships and second preset coefficient relationships), after the control module 30 determines the current weight information of the injection molding machine, a first preset coefficient relationship (a set of numerical values of A, B, C and D) and a second preset coefficient relationship (another set of numerical values of A, B, C and D) corresponding to the current weight information are obtained, the first preset coefficient relationship and the second preset coefficient relationship are different, and the first preset coefficient relationship is substituted into the first positioning control function to obtain a second positioning control function for controlling the driving module 40, that is, the first positioning control function is scaled and translated by adjusting the numerical values of A, B, C and D to obtain a second positioning control function, where the second positioning control function is a curve relationship about the displacement offset x of the driving shaft 110. Similarly, the second preset coefficient relationship is substituted into the first positioning control function, so as to obtain a third positioning control function for controlling the driving direction control module 50, and then, according to the displacement offset of the driving shaft 110, the second positioning control function and the third positioning control function, the first control signal and the second control signal are output, so that the driving module 40 adjusts the output flow according to the first control signal, and the driving direction control module 50 adjusts the opening size and the conduction direction according to the second control signal, so that the driving shaft 110 gradually moves to the target position, and the shaft positioning is completed.

It should be noted that, since the second positioning control function and the third positioning control function are related to the curve relationship of the displacement offset x of the driving shaft 110, that is, the numerical range of the control signal output by the second positioning control function and the third positioning control function is larger, but the control signal output by the shaft positioning system itself has an upper limit and a lower limit, when the control signal output by the second positioning control function and the third positioning control function is greater than the preset maximum signal, the final control signal transmitted to the driving module 40 and the driving direction control module 50 is the preset maximum signal; likewise, when the control signals output by the second positioning control function and the third positioning control function are smaller than the preset minimum signal, the final control signals transmitted to the driving module 40 and the driving direction control module 50 are the preset minimum signals; when the control signals output by the second positioning control function and the third positioning control function are between the preset maximum signal and the preset minimum signal, the control signals transmitted to the driving module 40 and the driving direction control module 50 are the control signals output by the second positioning control function and the third positioning control function. It will be appreciated that since the second positioning control function and the third positioning control function are obtained by substituting the first positioning control function into different coefficients, the limitations of the first positioning control function, the second positioning control function and the third positioning control function are the same.

Optionally, although the above embodiment can position the driving shaft 110 more precisely, it is suitable for most situations, but there is often a certain deviation in positioning due to interference of friction force and signals of the injection molding machine, so that the precise positioning is needed for adjusting the positioning.

In one embodiment, with continued reference to fig. 1, the control module 30 is further configured to output a third control signal according to a fourth positioning control function to adjust the drive module 40 after the shaft positioning system is adjusted according to the second positioning control function and the third positioning control function; and outputs a fourth control signal to adjust the drive direction control module 50 according to the fifth positioning control function.

Specifically, as shown in fig. 1, a fourth positioning control function and a fifth positioning control function are further provided in the control module 30, after the shaft positioning system approximately adjusts the injection molding machine corresponding to the current weight information through the second positioning control function and the third positioning control function, the shaft positioning system may also output a third control signal through the fourth positioning control function provided in the control module 30, and output the third control signal to the driving module 40, so that the driving module 40 controls the output flow according to the third control signal, thereby adjusting and controlling the magnitude of the driving force for controlling the motion of the driving shaft 110 to finely adjust the driving module; in addition, the control module 30 may output a fourth control signal through a fifth positioning control function provided therein, and output the fourth control signal to the driving direction control module 50, so that the driving direction control module 50 adjusts the opening size and the conducting direction thereof according to the fourth control signal, so as to finely adjust the position of the driving shaft 110. In this way, the control module approximately adjusts the driving shaft according to the first control signal and the second control signal output by the second positioning control function and the third positioning control function, then the control module outputs the third control signal according to the third positioning control function, the driving module receives the third control signal and then performs high-precision control on the output flow, in addition, the control module 30 outputs the fourth control signal according to the fourth positioning control function, the driving direction control module performs high-precision control on the opening size and the opening direction of the driving direction control module according to the fourth control signal, and finally fine positioning of the driving shaft is completed, interference of friction force, signals and other factors on positioning is avoided, and high-precision positioning is realized.

With continued reference to fig. 1, based on the above embodiments, the fourth positioning control function is:

wherein f (x) is a control signal output by the fourth positioning control function, E is a weight coefficient of the fourth positioning control function, and V is a signal output value of the preset flow of the driving module 40.

The fifth positioning control function is:

wherein g (x) is a control signal output by the fifth positioning control function, P is a weight coefficient of the fifth positioning control function, Q is an opening preset signal output value of the driving direction control module 50, and a sum of the weight coefficient of the fifth positioning control function and the weight coefficient of the fourth positioning control function is equal to 1.

The fourth positioning control function and the fifth positioning control function are high-precision positioning control functions, and the output characteristics of the fourth positioning control function and the fifth positioning control function are based on the learning of the positioning data sample by the control module. Specifically, before calculating the weight coefficient E of the fourth positioning control function, the position data X1, X2, X3 … … XN of the N driving axes 110 are collected, the maximum value Xmax and the minimum value Xmin of the positions in the N position data are obtained, and a formula is determined according to the weightAnd obtaining a weight coefficient E of the fourth positioning control function. Wherein X (n) is position information of the driving shaft 110 adjusted by the first control signal and the second control signal. V is a signal output value of the preset flow of the driving module 40, or may be understood as a signal output value when the driving module 40 outputs the preset flow during high-precision positioning, so that the control module 30 outputs a fourth control signal to the driving module 40 according to a weight coefficient of the fourth positioning control function and the signal output value of the preset flow of the driving module 40, so as to finely adjust the driving module 40. Since the sum of the weight coefficient of the fifth positioning control function and the weight coefficient of the fourth positioning control function is equal to 1, and then the weight coefficient P of the fifth positioning control function is calculated after the weight coefficient E of the fourth positioning control function is obtained, the control module 30 outputs a fourth control signal to the driving direction control module 50 according to the weight coefficient of the fifth positioning control function and the preset signal output value of the opening of the driving direction control module 50, so as to finely adjust the driving direction control module 50, thereby avoiding the interference of factors such as friction force and signals of the injection molding machine on positioning and realizing high-precision positioning.

Optionally, with continued reference to fig. 1, the driving direction control module 50 includes a proportional direction valve 510, where a control end of the proportional direction valve 510 is connected to the control module 30, a first end P of the proportional direction valve 510 is connected to the driving module 40, a second end a of the proportional direction valve 510 is connected to the first side of the hollow structure 120, a third end B of the proportional direction valve 510 is connected to the second side of the hollow structure 120, and a fourth end T of the proportional direction valve 510 is connected to the tank. The proportional directional valve 510 is configured to control the opening size of the proportional directional valve 510 and control the first end P of the proportional directional valve 510 to be in communication with the second end a of the proportional directional valve 510 or control the first end P of the proportional directional valve 510 to be in communication with the third end B of the proportional directional valve 510 according to the second control signal.

Specifically, the driving direction control module 50 includes a proportional direction valve 510, a control end of the proportional direction valve 510 is electrically connected to the control module 30, the control module 30 outputs a second control signal or a fourth control signal to the proportional direction valve 510, the proportional direction valve 510 controls the opening size of a valve core of the proportional direction valve 510 according to the second control signal or the fourth control signal, and controls the first end P of the proportional direction valve 510 and the second end a of the proportional direction valve 510 to be conducted according to the second control signal or the fourth control signal, so that the driving force provided by the driving module 40 passes through the proportional direction valve 510 to the first side of the hollow structure 120, and then the driving shaft 110 moves rightward along the extending direction of the hollow structure 120 under the action of the driving force, so as to control the driving shaft 110 to retreat; or the first end P of the proportional directional valve 510 and the third end B of the proportional directional valve 510 are controlled to be conducted according to the second control signal or the fourth control signal, so that the driving force provided by the driving module 40 passes through the proportional directional valve 510 to the second side of the hollow structure 120, and then the driving shaft 110 moves leftwards along the extending direction of the hollow structure 120 under the action of the driving force, so that the driving shaft 110 is controlled to advance, and thus the driving shaft 110 is controlled to move under the combined action of the proportional directional valve 510 and the driving module 40.

In yet another embodiment, with continued reference to FIG. 1, the shaft positioning system further includes a pressure detection module 60, the drive module 40 includes an oil pump 410, a servo motor 420, and an oil tank 430, the oil pump 410 is electrically connected to the servo motor 420, a first end of the oil pump 410 is in communication with the oil tank 430, and a second end of the oil pump 410 is in communication with the drive direction control module 50. The pressure detection module 60 is disposed on the oil pump 410 and is used for detecting a current flow signal of the oil pump 410, and the control module 30 is electrically connected with the pressure detection module 60 and is used for comparing the current flow signal with the first control signal to generate a fifth control signal and outputting the fifth control signal to the driving module 40, so that the driving module 40 controls the output flow of the oil pump 410 according to the fifth control signal.

Specifically, since the oil pump 410 itself has a certain pressure value (output flow), if the output flow of the oil pump 410 is directly controlled by the first control signal, the final control result may deviate, and the pressure detection module 60 is further disposed on the oil pump 410 and is used for detecting the current flow signal of the oil pump 410, the control module 30 outputs the fifth control signal according to the current flow signal and the first control signal, and the servo motor 420 further controls the oil pump 410 to increase the output flow or decrease the output flow based on the current output flow according to the fifth control signal, so as to ensure that the output flow of the driving module 40 can be accurately controlled.

Based on the above inventive concept, the embodiment of the invention also provides a control method of the shaft positioning system, which is applied to the shaft positioning system. Fig. 3 is a flowchart of a control method of a shaft positioning system according to an embodiment of the present invention, as shown in fig. 3, the control method includes:

s110, acquiring current weight information of the injection molding machine, determining a first preset coefficient relation and a second preset coefficient relation according to the current weight information, determining a second positioning control function according to the first positioning control function and the first preset coefficient relation, and determining a third positioning control function according to the first positioning control function and the second preset coefficient relation.

Specifically, the corresponding relation between the current weight information and a plurality of groups of first preset coefficient relation and second preset coefficient relation is set in the control module, and when the current weight information of the injection molding machine is confirmed, the first preset coefficient relation and the second preset coefficient relation corresponding to the current weight information can be obtained. In addition, a first positioning control function is also built in the control module, the coefficient of the first positioning control function is uncertain, and after a corresponding first preset coefficient relation and a corresponding second preset coefficient relation are obtained according to the current weight information, the first preset coefficient relation is substituted into the first positioning control function to obtain a second positioning control function, the second positioning control function is used for controlling the driving module, and the second positioning control function comprises a curve relation with the displacement offset of the driving shaft; and substituting the second preset coefficient relation into the first positioning control function to obtain a third positioning control function, wherein the third positioning control function is used for controlling the driving direction control module and comprises a curve relation with the displacement offset of the driving shaft. Specifically, the current weight information may be tonnage information of an injection molding machine, when the injection molding machines with different tonnages perform shaft positioning, the corresponding second positioning control function and third positioning control function are different, according to tonnage information of the injection molding machine, a first preset coefficient relation and a second preset coefficient relation corresponding to the tonnage information are determined, and the first preset coefficient relation and the second preset coefficient relation are respectively substituted into the first positioning control function to obtain the second positioning control function and the third positioning control function corresponding to the tonnage information. In addition, in other embodiments, the current weight information of the injection molding machine may also be model information of the injection molding machine, when the injection molding machines with different models perform shaft positioning, the corresponding second positioning control function and third positioning control function are also different, a first preset coefficient relation and a second preset coefficient relation corresponding to the model information are determined according to the model information of the injection molding machine, and the first preset coefficient relation and the second preset coefficient relation are respectively substituted into the first positioning control function to obtain the second positioning control function and the third positioning control function corresponding to the model information.

S120, acquiring the current position of the driving shaft, and obtaining the displacement offset according to the difference value between the current position and the target position.

The displacement detection module is connected with a driving shaft in the driving shaft module, and when the driving shaft moves in the hollow structure along the extending direction of the hollow structure, the change of the position of the driving shaft can be detected by the displacement detection module, so that the current position of the driving shaft is obtained. The control module is provided with a target position when the shaft positioning system performs shaft positioning, the control module is electrically connected with the displacement detection module, and then the control module compares the current position with the target position after detecting the current position of the driving shaft, and the difference value between the target position and the current position is the displacement offset of the shaft positioning system.

S130, outputting a first control signal to the driving module according to the second positioning control function and the displacement offset, so that the driving module outputs flow according to the first control signal to provide driving force for the driving shaft module; and outputting a second control signal to the driving direction control module according to the third positioning control function and the displacement offset, so that the driving direction control module adjusts the opening size and the opening direction of the driving direction control module according to the second control signal, and the driving force is transmitted to the driving shaft module through the driving direction control module to control the driving shaft to move along the extending direction of the hollow structure for shaft positioning.

The control module determines a first preset coefficient relation and a second preset coefficient relation according to the current weight information of the injection molding machine, determines a second positioning control function and a third positioning control function according to the first preset coefficient relation, the second preset coefficient relation and the first positioning control function, outputs a first control signal according to the displacement offset of the driving shaft and the second positioning control function, and outputs a second control signal according to the displacement offset of the driving shaft and the third positioning control function.

The control module is electrically connected with the driving module, and then the control module transmits a first control signal output according to the displacement offset of the driving shaft and the second positioning control function to the driving module, and the driving module outputs flow according to the first control signal and provides driving force for the movement of the driving shaft in the driving shaft module through the output flow.

The driving direction control module is communicated with the driving module and the driving shaft module. In addition, the driving direction control module is further electrically connected with the control module, and then the control module transmits a second control signal output according to the displacement offset of the driving shaft and a third positioning control function to the driving direction control module, and the driving direction control module controls the opening size and the conduction direction of the driving shaft according to the second control signal, so that the driving force provided by the driving module is transmitted to one side of the hollow structure through the driving direction control module, and then the driving shaft in the hollow structure is controlled to move forwards left or backwards right along the extending direction of the hollow structure, so that the driving shaft is controlled to gradually reach the target position, and shaft positioning is performed. Therefore, complex control algorithms are not required to be set for debugging respectively for different injection molding machines, and the shaft positioning can be performed only according to the corresponding second positioning control function and third positioning control function, so that the debugging difficulty is reduced, the debugging process is simple and convenient, the positioning efficiency and the positioning precision of the shaft positioning system are improved, and the cost of the shaft positioning system is reduced because a high-precision proportional valve/servo valve and a special motion controller are not required to be adopted.

In summary, the embodiment of the invention determines a first preset coefficient relation and a second preset coefficient relation according to current weight information of an injection molding machine, determines a second positioning control function according to the first positioning control function and the first preset coefficient relation, determines a third positioning control function according to the first positioning control function and the second preset coefficient relation, acquires the current position of a driving shaft, acquires a displacement offset according to the difference between the current position and a target position, and outputs a first control signal to a driving module according to the second positioning control function and the displacement offset, so that the driving module outputs flow according to the first control signal to provide driving force for the driving shaft module; and outputting a second control signal to the driving direction control module according to the third positioning control function and the displacement offset, so that the driving direction control module adjusts the opening size and the opening direction of the driving direction control module according to the second control signal, and the driving force is transmitted to the driving shaft module through the driving direction control module to control the driving shaft to move along the extending direction of the hollow structure for shaft positioning. When different injection molding machines are debugged, the second positioning control function and the third positioning control function corresponding to the current weight information are obtained only according to the current weight information of the injection molding machine and the first control function preset in the control module, and the control module outputs control signals according to the second positioning control function, the third positioning control function and the displacement offset to perform shaft positioning, so that the debugging process is simple and convenient, the positioning efficiency and the positioning precision of the shaft positioning system are improved, and the cost is reduced.

Further, fig. 4 is a flowchart of another control method of the shaft positioning system according to an embodiment of the present invention, as shown in fig. 4, the control method includes:

s210, acquiring current weight information of the injection molding machine, determining a first preset coefficient relation and a second preset coefficient relation according to the current weight information, determining a second positioning control function according to the first positioning control function and the first preset coefficient relation, and determining a third positioning control function according to the first positioning control function and the second preset coefficient relation.

S220, acquiring the current position of the driving shaft, and obtaining the displacement offset according to the difference value between the current position and the target position.

S230, outputting a first control signal to a driving module according to a second positioning control function and the displacement offset; acquiring a current flow signal of an oil pump; comparing the current flow signal with the first control signal, and outputting a fifth control signal to the driving module so that the driving module outputs flow according to the fifth control signal; and outputting a second control signal to the driving direction control module according to the third positioning control function and the displacement offset, so that the driving direction control module adjusts the opening size and the opening direction of the driving direction control module according to the second control signal, and the driving force is transmitted to the driving shaft module through the driving direction control module to control the driving shaft to move along the extending direction of the hollow structure for shaft positioning.

Specifically, since the oil pump itself has a certain pressure value (output flow), if the output flow of the oil pump is directly controlled by the first control signal, the final control result may deviate, and then the pressure detection module is arranged on the oil pump for detecting the current flow signal of the oil pump, the control module outputs the fifth control signal according to the current flow signal and the first control signal, and the servo motor further controls the oil pump to increase the output flow or reduce the output flow on the basis of the current output flow according to the fifth control signal, so that the output flow of the driving module can be accurately controlled.

S240, adjusting the comparative example directional valve according to the accuracy requirement of the fifth positioning control function.

Fig. 5 is a valve core flow chart of a proportional directional valve according to an embodiment of the present invention, as shown in fig. 5, after the driving shaft is adjusted by the second positioning control function and the third positioning control function, the driving shaft may be adjusted with high precision by the fourth positioning control function and the fifth positioning control function. Before the high-precision adjustment of the proportional directional valve is performed through the fifth positioning control function, the valve core characteristics of the proportional directional valve are required to be adjusted to meet the precision requirement of the fifth positioning control function, specifically, the valve core characteristics of the proportional directional valve are required to meet the requirement of low loss under the condition of high flow pressure difference by setting large slopes for the flow characteristics of the first conducting opening P-A and the second conducting opening P-B of the proportional directional valve under the rated flow, namely the slope of the first conducting opening P-A is larger than the slope of the A-T, and the slope of the second conducting opening P-B is larger than the slope of the B-T, so that unnecessary energy loss is reduced. In addition, the valve core high-resolution adaptation injection molding machine high-precision positioning can be arranged in the positioning interval, so that the precision requirement of the fifth positioning control function is met.

S250, outputting a third control signal to the driving module according to the fourth positioning control function so that the driving module controls the flow output of the driving module according to the third control signal; and outputting a fourth control signal to the driving direction control module according to the fifth positioning control function so that the driving direction control module adjusts the opening size and direction of the driving direction control module according to the fourth control signal.

Specifically, a fourth positioning control function and a fifth positioning control function are further arranged in the control module, after the driving mechanism corresponding to the current weight information is approximately regulated by the shaft positioning system through the second positioning control function and the third positioning control function, a third control signal can be output through the fourth positioning control function arranged in the control module, and the third control signal is output to the driving module, so that the driving module controls the output flow according to the third control signal, and the driving force for controlling the movement of the driving shaft is regulated, so that the driving module is finely regulated; in addition, the control module can also output a fourth control signal through a fifth positioning control function arranged in the control module, and the fourth control signal is output to the driving direction control module, so that the driving direction control module adjusts the size and the conduction direction of the opening of the driving direction control module according to the fourth control signal, and the position of the driving shaft is finely adjusted.

In summary, after the second positioning control function and the third positioning control function regulate the driving shaft, the embodiment of the invention can also output a third control signal to the driving module according to the fourth positioning control function, so that the driving module controls the flow output of the driving module according to the third control signal; according to the fifth positioning control function, a fourth control signal is output to the driving direction control module, so that the driving direction control module adjusts the opening size and the direction of the driving direction control module according to the fourth control signal, and after the second positioning control function and the third positioning control function adjust the driving shaft, the driving shaft can be finely adjusted according to the fourth positioning control function and the fifth positioning control function, the interference of factors such as friction force and signals of the injection molding machine on positioning can be avoided, and high-precision positioning is realized.

Note that the above is only a preferred embodiment of the present invention and the technical principle applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, while the invention has been described in connection with the above embodiments, the invention is not limited to the embodiments, but may be embodied in many other equivalent forms without departing from the spirit or scope of the invention, which is set forth in the following claims.

Claims

1. The shaft positioning system of the injection molding machine is characterized by comprising a driving shaft module, a displacement detection module, a control module, a driving module and a driving direction control module;

the control module is used for generating a first preset coefficient relation and a second preset coefficient relation according to the current weight information of the injection molding machine, determining a second positioning control function according to a first positioning control function and the first preset coefficient relation, determining a third positioning control function according to the first positioning control function and the second preset coefficient relation, outputting a first control signal according to the second positioning control function and the displacement offset, and outputting a second control signal according to the third positioning control function and the displacement offset, wherein the first positioning control function comprises a curve relation of the displacement offset;

2. The shaft positioning system of claim 1, wherein the first positioning control function is:

3. The shaft positioning system of claim 1, wherein the control module is further configured to output a third control signal according to a fourth positioning control function to adjust the drive module after the shaft positioning system is adjusted according to the second positioning control function and the third positioning control function; and outputting a fourth control signal according to a fifth positioning control function to adjust the driving direction control module.

4. A shaft positioning system as in claim 3, wherein the fourth positioning control function is:

the fifth positioning control function is:

5. The shaft positioning system of claim 1, wherein the drive direction control module comprises a proportional directional valve; the control end of the proportional direction valve is connected with the control module, the first end of the proportional direction valve is communicated with the driving module, the second end of the proportional direction valve is communicated with the first side of the hollow structure, the third end of the proportional direction valve is communicated with the second side of the hollow structure, and the fourth end of the proportional direction valve is communicated with the oil tank; the proportional direction valve is used for controlling the opening size of the proportional direction valve and controlling the first end of the proportional direction valve to be communicated with the second end of the proportional direction valve or controlling the first end of the proportional direction valve to be communicated with the third end of the proportional direction valve according to the second control signal.

6. The shaft positioning system of claim 1, further comprising a pressure detection module, the drive module comprising an oil pump, a servo motor, and an oil tank, the oil pump being electrically connected to the servo motor, a first end of the oil pump being in communication with the oil tank, a second end of the oil pump being in communication with the drive direction control module;

7. A control method of a shaft positioning system applied to the shaft positioning system of an injection molding machine according to any one of claims 1 to 6, characterized by comprising:

8. The control method of claim 7, wherein the shaft positioning system further comprises a pressure detection module, the drive module comprises an oil pump, a servo motor, and an oil tank, the oil pump is electrically connected to the servo motor, a first end of the oil pump is in communication with the oil tank, and a second end of the oil pump is in communication with the drive direction control module;

9. The control method according to claim 7, wherein a first control signal is output to a drive module in accordance with the second positioning control function and the displacement offset, so that the drive module outputs a flow rate in accordance with the first control signal to provide a driving force for the drive shaft module; outputting a second control signal to a driving direction control module according to the third positioning control function and the displacement offset, so that the driving direction control module adjusts the opening size and direction of the driving direction control module according to the second control signal, so that the driving force is transmitted to the driving shaft module through the driving direction control module, and after the driving shaft is controlled to move along the extending direction of the hollow structure to perform shaft positioning, the driving shaft positioning device further comprises:

10. The control method of claim 9, wherein the drive direction control module comprises a proportional directional valve;