TWI588006B - Injection molding machine clamping force setting method and system - Google Patents

Description

Injection molding machine clamping force setting method and system thereof

The invention relates to a clamping force setting method, in particular to a method and a system for setting a clamping force of an injection molding machine.

The injection molding machine used in the general industry includes models of injection molding machines such as three-plate type, two-plate type, and no large column type. Among them, the plastic (or polymer) is molded into a product having a certain shape and size by using a specific shape of the injection mold itself. At the time of injection molding, a predetermined mold clamping force is applied by a mold that is closed/closed, and then molten resin is injected into the mold.

Referring to Fig. 1, an injection molding machine 10 presses the metal mold 12 with an excessive clamping force 11, and when the molten resin 14 is injected by an injection force 13, the air in the metal mold 12 cannot be smoothly discharged. The generation of air bubbles in the injection product 15 not only lowers the quality of the product, but also causes problems such as a decrease in the life of the metal mold and an increase in energy consumption.

Referring to FIG. 2, the metal mold 12 is pressed by the injection molding machine 10 with an insufficient clamping force 11, and when the molten resin 14 is injected by an injection force 13, the metal mold 12 will be insufficient to resist the injection force 13, and This causes the metal mold 12 to be stretched, causing the exit product 15 to have a problem of flashing.

Therefore, how to obtain appropriate clamping force in different injection molding machines, and at the time of injection molding, the metal mold does not open to the minimum to prevent the occurrence of flash, and can smoothly smooth the air in the metal mold. Discharging, in order to smoothly carry out the injection molding process, is one of the topics worthy of study.

Accordingly, it is an object of the present invention to provide a clamping force setting method for an injection molding machine suitable for calculating an appropriate clamping force value of the injection molding machine, the injection molding machine comprising at least one fixing post and one disposed on a fixing wall at one end of the fixing column, a first mold disposed on the fixing wall, a movable wall disposed on the fixing wall and slidable on the fixing wall, being fixed to the movable wall and detachably a second mold joined by the first mold, and a clamping module coupled to the movable wall, the clamping module moving the second mold to engage and separate the second mold and the first mold, and An injection material is injection molded, and the clamping force setting method comprises the following steps:

First, a sensor setting step is performed, and a sensor is disposed in the injection molding machine to sense the clamping force of the injection molding machine.

Then, a clamping force sensing step is performed, the clamping module combines the second mold with the first mold with a clamping force of any size, and then injects the injection material, and records the sensor. The multiple clamping force obtained, and the corresponding clamping force increment.

Finally, a step of obtaining a suitable clamping force is performed, and the stored clamping force of different numbers and the corresponding clamping force increment are analyzed by an automatic curve fitting judgment method, and the automatic curve fitting is performed. When the judging method analyzes the second line segment, the appropriate clamping force value of the injection molding machine is ±10% of the intersection value of the two line segments.

Another technical means of the present invention is that in the step of obtaining an appropriate clamping force, when the automatic curve fitting judgment method cannot analyze the second line segment, the two intersection points are obtained by a curve fitting method, and the two points are obtained. ±10% of the average of the intersection points is the appropriate clamping force value.

Another technical means of the present invention is that in the step of obtaining the appropriate clamping force, the second curve segment cannot be formed when the automatic curve fitting judgment method is analyzed, and the average slope of the connecting line of the complex clamping force increment is greater than When β is used, the appropriate clamping force value of the injection molding machine cannot be obtained.

A further technical means of the present invention is that in the step of obtaining an appropriate clamping force, when the automatic curve fitting judgment method analyzes the occurrence of two line segments, and the slope of one of the line segments is larger than β, and the slope of the other line segment is greater than γ The appropriate clamping force value of the injection molding machine cannot be obtained.

Another technical means of the present invention is that in the sensor setting step, the sensor is a strain gauge disposed on the fixed column to sense the strain amount of the fixed column.

Another technical means of the present invention is that in the sensor setting step, the sensor is a linear displacement transducer disposed on the first mold and the second mold to A relative displacement amount of the first mold and the second mold is sensed.

Still another technical means of the present invention is that the above-mentioned ejection material is selected from the group consisting of plastics, metal powders, wood powders, ceramic ingots, and combinations thereof.

Another technical means of the present invention is that in the above-mentioned clamping force sensing, the temperature of the first mold and the second mold must be controlled to prevent the sensing clamping force from being subjected to the first and second mold temperatures. interference.

Another object of the present invention is to provide an injection molding machine clamping force setting system suitable for the above-described injection molding machine clamping force setting method, and comprising at least one sensor and a clamping force calculator.

The sensor is disposed in the injection molding machine. The clamping force calculator is electrically connected to the sensor and obtains a clamping force value of the injection molding machine.

A further technical means of the present invention is that the above-mentioned clamping force calculator comprises a computing module and a memory module electrically connected to the computing module, the memory module can record different clamping force, and The corresponding clamping force increment is provided to provide the calculation module to calculate the appropriate clamping force value of the injection molding machine.

The beneficial effect of the present invention is that the clamping module pushes the second mold toward the first mold with the clamping force of different sizes, and the second The mold is pushed toward the first module, and the first and second modules are closely connected together. The injection material is then injection molded, and the increment of each time is recorded by the sensor to record the corresponding increase in the modulus of force when different clamping forces are recorded. Finally, the appropriate clamping force value of the injection molding machine is obtained by the automatic curve fitting judgment method.

a‧‧‧Clamping force value of the clamping module

b‧‧‧Induction maximum clamping force value

c‧‧‧Clamping force increment

3‧‧‧Injecting materials

5‧‧‧Injection molding machine

51‧‧‧Fixed column

52‧‧‧Fixed wall

53‧‧‧First mould

54‧‧‧ movable wall

55‧‧‧Second mold

56‧‧‧Clock module

7‧‧‧Clamping force setting system

71‧‧‧ Sensors

72‧‧‧Clamping force calculator

721‧‧‧Computation Module

722‧‧‧Memory Module

901~903‧‧‧Steps

L1‧‧‧ first line

L2‧‧‧ second line

L3‧‧‧ third line segment

L4‧‧‧ fourth line

L5‧‧‧ fifth line

L6‧‧‧ sixth line

L7‧‧‧ seventh line

L8‧‧‧ eighth line

P1‧‧‧ first intersection

P2‧‧‧ second intersection

P3‧‧‧ third intersection

Average of the second and third intersections of P4‧‧‧

α‧‧‧Appropriate clamping force value

1 is a schematic view showing a state in which a general injection molding machine uses an excessively large clamping force; FIG. 2 is a schematic view showing a state in which a general injection molding machine uses a small clamping force; FIG. 3 is a schematic view of the apparatus, illustrating the present invention. In the first preferred embodiment of the method for setting the clamping force of the injection molding machine and the system thereof, an injection molding machine is shown; FIG. 4 is a flow chart illustrating the implementation steps of the first preferred embodiment; A block diagram illustrating the component relationship of the first preferred embodiment; and FIG. 6 is an analysis diagram illustrating the clamping force of the injection molding machine when an injection material is injection molded in the first preferred embodiment. FIG. 7 is an analysis diagram illustrating an analysis of the clamping force increment of the relative clamping force in the first preferred embodiment; FIG. 8 is an analysis diagram illustrating the first In the second embodiment, the analysis of the clamping force increment relative to the complex clamping force; FIG. 9 is an analysis diagram illustrating the relative preferred clamping force of the first preferred embodiment in the third form. An analysis chart of the clamping force increment; FIG. 10 is an analysis diagram, FIG. 11 is a schematic view showing the clamping force of the injection molding machine of the present invention, and the system thereof. In the second preferred embodiment, an aspect of the molding machine is injected.

The detailed description of the preferred embodiments of the present invention will be apparent from the detailed description of the preferred embodiments.

Referring to Figures 3, 4 and 5, a first preferred embodiment of a method for setting a clamping force of an injection molding machine 5 and a system thereof according to the present invention is a clamping force setting method suitable for calculation. The appropriate clamping force value of the injection molding machine 5 is output. The injection molding machine 5 includes at least one fixing post 51, a fixing wall 52 disposed at one end of the fixing post 51, a first mold 53 disposed on the fixing wall 52, and a set of the fixing wall 52. a movable wall 54 sliding on the fixed wall 52, a second mold 55 fixed to the movable wall 54 and detachably coupled to the first mold 53, and a clamping module 56 connected to the movable wall 54 The mold clamping module 56 moves the second mold 55 to join and separate the second mold 55 and the first mold 53 to provide an injection material 3 for injection molding.

In the first preferred embodiment, a four-column full-electric horizontal injection molding machine is used, which is one of the commonly used models in the industry. Since the use technology of the injection molding machine 5 is already a familiar technique in the industry, Therefore, the details of the injection molding machine 5 can be used in the actual implementation, and should not be limited thereto. Further, the injection material 3 is selected from the group consisting of plastics, metal powders, wood powders, ceramic ingots, and the like, and is used in the injection molding machine 5 to perform an injection process.

The clamping force setting method of the present invention comprises a sensor setting step 901, a clamping force sensing step 902, and a suitable clamping force step 903, which is suitable for an injection molding machine 5 clamping force setting system 7. The clamping force setting system 7 includes at least one sensor 71 disposed in the injection molding machine 5, and a clamping force electrically connected to the sensor 71 and obtaining the clamping force value of the injection molding machine 5. Calculator 72. The clamping force calculator 72 includes a computing module 721 and a memory module 722 electrically coupled to the computing module 721. The memory module 722 can record different clamping forces and corresponding clamping forces. Incremental to provide the calculation module 721 to calculate the injection The appropriate clamping force value of the molding machine 5.

First, the sensor setting step 901 is performed in which the sensor 71 is disposed in the injection molding machine 5 to sense the clamping force value of the injection molding machine 5. In the first preferred embodiment, the sensor 71 is a strain gauge disposed on the fixed post 51 to sense the strain amount of the fixed post 51.

The strain gauge is a circuit sensor attached to the fixing post 51. The resistance value of the metal wire is used to measure the strain of the metal. In terms of the characteristics of the resistor, the resistance value changes with the length. Proportional change. However, there is a very important concept that the adherent strain gauge must be integrated with the test body (the fixed post 51). Therefore, the strain gauge must be carefully attached to the fixed post 51 to improve the accuracy of the test. degree.

The strain gauge is derived by the following formula (1) to derive the clamping force value of the injection molding machine 5;

ε=Tie bar stress-strain(u ε)

E=Tie bar Young’s modulus

A=Tie bar cross sectional area(mm2)

F=clamping force(Tonf)

Therefore, the first preferred embodiment finds the following formula (2) in accordance with the relevant data of the injection molding machine 5 used to sense the clamping force value of the injection molding machine 5:

Then, the clamping force sensing step 902 is performed. The clamping module 56 combines the second mold 55 with the first mold 53 with a clamping force of any size, and then the injection material 3 is injected. And recording the complex clamping force obtained by the sensor 71, and the corresponding clamping force Incremental.

Referring to FIG. 6, the mold clamping module 56 of the injection molding machine 5 pushes the second mold 55 toward the first mold 53 with a clamping force value a, so that the first and second molds 53 and 55 are tight. Together, the injection material 3 is injection molded, and the time curve of the mold clamping force value of the injection molding machine 5 is sensed by the sensor 71. The horizontal axis is the time when the injection material 3 is injected, and the vertical axis is the clamping force value of the mold clamping module 56 of the injection molding machine 5 sensed by the sensor 71.

As can be seen from FIG. 6, when the injection material 3 is injected into the first and second molds 53, 55 with a fixed injection force, the pressure in the first and second molds 53, 55 is increased and the support force is generated from the inside. At this time, the fixing column 51 connected to the first and second fixing walls 52, 54 is prolonged, so that the clamping force of the inductive injection molding machine 5 will rise, and when the injection material 3 stops being injected, the The air in the first and second dies 53, 55 is discharged from the gap, releasing the pressure in the first and second dies 53, 55, and reducing the length of the fixed wall 52, resulting in the lock of the injection molding machine 5. The mold force will reply. Wherein, the maximum clamping force value b sensed by the sensor 71 is subtracted from the clamping force value a of the clamping module 56, and a clamping force increment value c can be obtained.

In the clamping force sensing step 902, the clamping module 56 combines the first and second molds 53 and 55 with clamping force of different sizes, and performs the injection process with a fixed injection force. The memory module 722 of the clamping force calculator 72 can record different clamping forces and corresponding clamping force increments.

Finally, the step of obtaining the appropriate clamping force is performed, and the stored clamping force of different numbers and the corresponding clamping force increment are analyzed by an automatic curve fitting judgment method, and the automatic curve is used. When the two-line segment is analyzed by the fitting judging method, the appropriate clamping force value of the injection molding machine 5 is taken as ±10% of the intersection value of the two-line segment.

Referring to Figure 7, is a graph of the clamping force increment (type 1), The calculation module 721 is formed by an automatic curve fitting judgment method, and the different clamping force recorded by the memory module 722 and the corresponding clamping force increment are drawn, wherein the horizontal axis is the clamping mode The clamping force of the plurality of different sizes applied by the group 56, and the vertical axis is the clamping force increment when the injection material 3 is injection molded.

It can be seen from FIG. 7 that when the clamping force of the clamping module 56 is set to be small, the ejection material 3 increases the pressure in the first and second molds 53, 55, resulting in the fixing. The sensor 71 on the column 51 can sense a larger clamping force increment; and when the clamping force setting of the clamping module 56 is set larger, the second module 55 can be used to the first module. 53 will generate a large pressing force, even if the pressure in the first and second molds 53, 55 is increased, it is not enough to cause the fixed column 51 to be stretched, so that the clamping force sensed by the sensor 71 The increment is flat. The calculation module 721 can analyze the stored data into two line segments (the first line segment L1 and the second line segment L2), and use the intersection value of the two line segments (the first line segment L1 and the second line segment L2) ±10% of the first intersection P1) (appropriate clamping force value α) is a suitable clamping force value of the injection molding machine 5.

Referring to FIG. 8 , which is a graph of the clamping force increment (type 2), the horizontal axis is the clamping force of the complex size applied by the clamping module 56, and the vertical axis is the injection molding of the injection material 3 . The clamping force is increased in time. When the automatic curve fitting judgment method cannot analyze the two line segments, the two intersection points (the second intersection point P2 and the third intersection point P3) are obtained by a curve fitting method, and the two intersection points (the second intersection point P2 and the third intersection point) are obtained. ±10% (appropriate clamping force value α) of the average value of P3) (the average value P4 of the second intersection P2 and the third intersection P3) is an appropriate clamping force value of the injection molding machine 5.

Among them, the curve fitting method used in (Type 2) is to divide the complex clamping force of the horizontal axis into three segments from small to large, and then calculate the average slope of the complex clamping force increment of each segment. And draw a three-line segment (third line segment L3, fourth line segment L4, fifth line segment L5), and then find the two intersection points of the three-line segment (third line segment L3, fourth line segment L4, fifth line segment L5) Two pay Point P2, third intersection point P3), and finally the average value of the two intersection points (second intersection point P2, third intersection point P3) (±10% of the second intersection point P2 and the average value P4 of the third intersection point P3) The appropriate clamping force value α) is the appropriate clamping force value of the injection molding machine 5.

Referring to FIG. 9 , which is a graph of the clamping force increment (type 3), the horizontal axis is the clamping force of the complex size applied by the clamping module 56, and the vertical axis is the injection molding of the injection material 3 . The clamping force is increased in time. When the automatic curve fitting judgment analysis cannot occur the two-line segment, and the average slope of the connecting line of the complex clamping force increment (the sixth line segment L6) is larger than β, the appropriate clamping force of the injection molding machine 5 cannot be obtained. value.

Wherein, the clamping module 56 has a plurality of clamping force (mode 3) that is too low, and when the first and second molds 53 and 55 are joined and the injection process is performed, a burr is generated on the product, and the graph appears. A more inclined curve. Therefore, the slope β is a condition for judging whether the clamping force used is too low. When a curve having an average slope greater than β occurs, the clamping force of the clamping module 56 must be reset, and the clamping force sensing is performed again. Step 902, and the obtaining a suitable clamping force step 903. Since the different injection molding machines 5 have different judgment slopes β, the actual measurement should be performed in conjunction with the injection molding machine 5 used to determine β.

Referring to FIG. 10, which is a graph of the clamping force increment (type 4), the horizontal axis is the clamping force of the complex size applied by the clamping module 56, and the vertical axis is the injection molding of the injection material 3. The clamping force is increased in time. When the automatic curve fitting judgment method analyzes the two line segments (the seventh line segment L7, the eighth line segment L8), and the slope of one of the line segments (the seventh line segment L7) is larger than β, the slope of the other line segment (the eighth line segment L8) When it is larger than γ, the appropriate clamping force value of the injection molding machine 5 cannot be obtained, wherein the slope value γ is larger than β (the eighth line segment L8 is oblique to the seventh line segment L7).

When the clamping module 56 is combined with the lower clamping force (mode 4), the first and second molds 53, 55 are joined and the injection process is performed, the product will generate flash, and the graph will not only appear. a line segment larger than β, A line segment larger than γ will appear. Therefore, when the graph shows a two-line segment (the seventh segment L7, the eighth segment L8), and the slopes of the two segments (the seventh segment L7 and the eighth segment L8) are larger than β and γ, respectively. At this time, the clamping force of the clamping module 56 must be reset, the clamping force sensing step 902 is performed again, and the appropriate clamping force step 903 is obtained. Since the different injection molding machines 5 have different judgment slopes β and γ, in actual measurement, the injection molding machine 5 used should be used to determine β and γ.

Referring to FIG. 11, a second preferred embodiment of the method for setting the clamping force of the injection molding machine 5 and the system thereof is substantially the same as the first preferred embodiment, and the same is true here. The difference is that, in the sensor setting step 901, the sensor 71 is a linear displacement transducer disposed on the first mold 53 and the second mold 55. To sense the relative displacement amount of the first mold 53 and the second mold 55.

Preferably, the linear displacement sensor is an optical sensor capable of measuring the displacement between the first and second molds 53, 55 with extremely high precision to calculate the mold clamping mold lock. The clamping force used, and the amount of clamping force generated when the injection material 3 is injection molded. Since high-precision linear displacement sensors are well-known in the industry, they will not be described in detail herein.

In addition, when the sensor 71 senses the clamping force, the deformation amount of the fixing post 51 or the relative displacement of the first and second molds 53 and 55 is small, and is easily interfered by the external temperature, and must be The temperature controller is used to control the temperature of the first mold 53 and the second mold 55 to prevent the clamping force from being disturbed by the temperatures of the first and second molds 53, 55, and the measured data is changed. The technique of using a thermostat to control temperature and stabilize temperature has been familiar to the industry and will not be described here.

Referring to Tables 1, 2, and 3, the inventors used PC (Table 1), ABS (Table 2), and PC + ABS (Table 3) three plastics, respectively, to perform the clamping force setting method to separately determine the injection molding. Machine 5 is applied to different shots Appropriate clamping force value for material 3. After the clamping force calculator 72 is calculated, when the plastic of PC material is used, the appropriate clamping force of the injection molding machine 5 is 32Ton~52Ton; when the plastic of ABS material is used, the injection molding machine 5 is suitable. The clamping force value is 31Ton~51Ton; when using PC+ABS plastic, the appropriate clamping force of the injection molding machine 5 is 30Ton~50Ton. In practice, the clamping force setting system 7 can be installed in other forms of the injection molding machine 5, and the injection material 3 of other materials can also be used, and should not be limited thereto.

Table 3: ABS+PC plastic

In summary, the present invention measures and calculates the clamping force of the injection molding machine 5 by using the deformation of the fixing column 51 of the injection molding machine 5 or the relative displacement of the first and second molds 53, 55. And when the injection material 3 is used for the injection process, the clamping force increment of the injection molding machine 5 is obtained, and the clamping force of the plurality of different sizes is used to draw a graph of the clamping force increment. The appropriate clamping force is calculated by the automatic curve fitting judgment method to avoid the product smashing caused by the excessive clamping force, and the excessive clamping force causes energy waste or mold damage, so the object of the present invention can be achieved.

However, the above is only the two preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes made according to the scope of the present invention and the description of the invention are Modifications are still within the scope of the invention.

901~903‧‧‧Steps

Claims (9)

A method for setting a clamping force of an injection molding machine, which is suitable for calculating a suitable clamping force value of the injection molding machine, the injection molding machine comprising at least one fixing column, a fixed wall disposed at one end of the fixing column, and a a first mold for fixing the wall, a movable wall disposed on the fixed wall and slidable on the fixed wall, a second mold fixed to the movable wall and detachably engageable with the first mold, and a The movable wall is connected to the clamping module, the clamping module moves the second mold, and the second mold is engaged and separated from the first mold, and an injection material is provided for injection molding, and the clamping force is set. The method comprises the following steps: a sensor setting step, a sensor is arranged in the injection molding machine to sense the clamping force of the injection molding machine; and a clamping force sensing step, the clamping module is The clamping force of any size is combined to combine the second mold with the first mold, and then the injection material is injected, and the complex clamping force obtained by the sensor and the corresponding clamping force increment are recorded. , the complex clamping force a stable clamping force after injecting the injection material, the corresponding clamping force increment is taken from the maximum clamping force when the injection material is injected minus the corresponding clamping force; and a step of obtaining a suitable clamping force , the stored clamping force of different sizes and the corresponding clamping force increment of the complex number are analyzed by an automatic curve fitting judging method. When the automatic curve fitting judging method analyzes the second line segment, The ±10% of the intersection value of the two line segments is the appropriate clamping force value of the injection molding machine. The method for setting a clamping force of an injection molding machine according to claim 1, wherein in the step of obtaining an appropriate clamping force, when the automatic curve fitting judging method cannot analyze the second line segment, the curve is further The two intersection points are obtained by the fitting method, and ±10% of the average value of the two intersection points is the appropriate clamping force value. The method for setting a clamping force of an injection molding machine according to claim 2, wherein in the step of obtaining an appropriate clamping force, when the automatic curve fitting judgment analysis cannot generate a two-line segment, and the complex clamping mode When the average slope of the force-increasing connecting line is larger than β, the appropriate clamping force value of the injection molding machine cannot be obtained. The method for setting a clamping force of an injection molding machine according to claim 3, wherein in the step of obtaining an appropriate clamping force, when the automatic curve fitting judging method analyzes the occurrence of the second line segment, and the slope of one of the line segments When it is larger than β and the slope of the other line segment is larger than γ, the appropriate clamping force value of the injection molding machine cannot be obtained. The method for setting a clamping force of an injection molding machine according to claim 1, wherein in the sensor setting step, the sensor is a strain gauge disposed on the fixed column, The strain amount of the fixed column is sensed. The method for setting a clamping force of an injection molding machine according to claim 1, wherein in the sensor setting step, the sensor is a linear displacement transducer, and is disposed at the sensor The first mold and the second mold are configured to sense a relative displacement amount of the first mold and the second mold. The method for setting a clamping force of an injection molding machine according to claim 1, wherein the injection material is selected from the group consisting of plastics, metal powders, wood powders, ceramic blanks, and combinations thereof. The method for setting a clamping force of an injection molding machine according to claim 1, wherein in the clamping force sensing, the temperature of the first mold and the second mold must be controlled to avoid sensing. The clamping force is disturbed by the temperature of the first and second molds. The invention relates to a mold clamping force setting system for injection molding machine, which is suitable for the method for setting the clamping force of the first injection molding machine of the patent application scope, and comprises: at least one sensor disposed in the injection molding machine; and a clamping force calculation The device is electrically connected to the sensor and includes a computing module and a memory module electrically connected to the computing module, the memory module can record different clamping force and corresponding clamping force Incremental to provide the calculation module to calculate the appropriate clamping force value of the injection molding machine.