JP2598687Y2 - Inspection equipment for injection molding machines - Google Patents

Description

[Detailed description of the invention]

[0001]

INVENTION The present invention relates to relates to a product quality determination device for an injection molding machine, in particular, and determining the acceptability of a product by comparing the filling time of the molding material into the mold and the reference filling time
The present invention relates to a device for judging the quality of a product of an injection molding machine to be corrected .

[0002]

2. Description of the Related Art In injection molding, a molding material such as plastics or rubber melted by heating is injected and filled into a mold.
It is performed by taking out as a molded product after solidification. Injection molding machine for performing this injection molding, by heating and melting the molding material, the mold clamping equipment extruder 9 injection molding material, to hold the mold perform closing and tightening your and variable capacitance Po
It comprises a control device 16 for automatically controlling the pump 15 and the like. As shown in FIG. 3, this conventional injection molding machine includes an extruder 9 for injecting a molding material from a nozzle 7 into a cavity 8 formed between an upper mold 1a and a lower mold 1b.
have. The extruder 9 has a heating cylinder 11 into which an injection screw 10 is inserted so as to be movable in the axial direction. The heating cylinder 11 is formed with a flow path 12 for flowing hot oil. The rotation of the screw 10 melts the molding material introduced into the heating cylinder.

On the other hand, the injection screw 10 moves in the heating cylinder 11 by moving the injection hydraulic cylinder 14 forward and backward while being rotated by a screw drive hydraulic motor (not shown). The hydraulic device 13 for driving the injection hydraulic cylinder 14 includes a variable displacement pump 15, a direction switching valve (not shown) for switching a pressure feeding direction of a pressure fluid pumped from the variable displacement pump 15, An electromagnetic relief valve (not shown) for maintaining the pressure of the fluid at a predetermined pressure is provided. The drive control of the hydraulic device 13 is performed by the control device 16. In order to perform injection molding with such an injection molding machine, the extruder 9 is brought close to the upper mold 1a, and the nozzle 7 of the extruder is brought into contact with the injection port 17 of the cavity 8.
Drives the hydraulic cylinder 14 for exiting morphism Te, by moving the injection screw 10 in the nozzle direction for injecting extruding a molding material through a nozzle 7 into the cavity 8.

[0004]

[Devised Problems to be Solved] is constituted as described above
The injection stroke of the injection molding machine can be broadly divided into a filling stroke and a pressure-holding stroke. However, the control of switching from the filling stroke to the pressure-holding stroke of the conventional injection molding machine is performed when the injection screw 10 is pushed in the nozzle direction. The push-out position of the injection screw is simply detected by the position sensor 18, and when the injection screw comes to the preset push-out position, the hydraulic device 1
Set the oil pressure acting on the injection screw by 3 to the set pressure
The pressure is reduced to a pressure- holding stroke. This
In the case of plastic molding material, the
Even if the temperature control of the oil is inadequate, large changes in viscosity
No feed-forward control
Because there is.

[0005] In the case of a rubber molding material, when the filling of the material is not completed within a predetermined time in the filling process,
That is, when too long filling time, because the molding material flows within the cavity while affected by the heat from the mold, vulcanization
Acceleration, poor flow, and poor joint at insufficient joining at the junction of the materials occur. Due to the occurrence of such a defect, a defect defect or material of the molded product is reduced. On the other hand, if the filling time is too short in the filling step, that is, if the injection speed is too fast, jetting is likely to occur due to frictional heat generated when the molten material flows in the cavity.

Therefore, in the filling process, it is necessary to complete filling within 100% with respect to the cavity volume and at the same time, within a predetermined time (hereinafter referred to as an allowable filling time). Since the required time is not particularly monitored and the molding conditions are set based on the operator's experience, etc., there is a possibility that defective products are frequently generated due to the judgment of the molding conditions and the setting error of the molding conditions. In particular, in the viscoelastic material such as rubber material, during the molding of the molding material
Injection speed varies viscosity and the like is varied by the temperature difference
Therefore , the filling time often fluctuates due to such physical property changes. Therefore, like sequence control
One molding cycle is passed through a counter such as a timer.
Even if over-management is performed, the injection speed will change,
Had occurred.

The present invention has been made in view of such problems of the prior art, and improves the molding quality by determining the quality of a molded product based on a filling time according to a molding material. The purpose is to automate injection molding.

[0008]

The present invention solves the above-mentioned problems.
It has been made to solve the problem and its technical means
Is a product of an injection molding machine controlled by the control device (20).
An injection screw of an injection molding machine, which is a quality evaluation device.
(10) Injection opening for filling the rubber molding material into the mold (1)
Position sensor (18) for detecting a start position and an injection end position
And the injection start position signal from the position sensor (18) and the injection
An input unit (2) for receiving an end position signal, and an input unit
The start and end of the injection start position signal input to (2)
Fill time to calculate the time difference from the end position signal end time
For each of the processing unit (3) and the mold (1),
And the standard filling time calculated from the molding conditions measured
An allowable filling time setting section (4) for inputting and storing,
Reference filling time and filling time calculating section of filling time setting section (4)
Compare the time difference calculated in (3) and within the reference filling time
A judging unit (5) for judging whether or not there is, and a judging unit
A signal indicating the quality is displayed in response to the signal determined in (5).
A pass / fail display unit (6);
The time difference calculated by the charging time calculation unit (3) is determined at the time of the charging.
Molding material so as to be within the reference filling time of the interval setting section (4)
Plasticizing device (19) that controls and maintains the plasticizing state of
Have The injection molding according to claim 2 of the present invention.
In the product quality judgment device of the machine, the judgment unit (5) calculates the filling time
The time difference calculated in section (3) is the allowable filling time setting section
When it is outside the reference filling time of (4), the controller (20)
Enter the feedback signal and it will be within the reference filling time
Control, and the injection end position signal is input.
But switching to the pressure-holding step by the control equipment (20)
is there.

[0009]

When a viscoelastic material such as rubber is injection-molded, the physical properties fluctuate due to a difference in manufacturing lot or a difference in viscosity , so that even if the filling time to be injected fluctuates, the appropriate reference filling time according to the material type is not Does not fluctuate. Based on this knowledge, the reference filling time of the material to be molded is measured and stored in the allowable filling time setting section as the allowable filling time. Then, when starting the material filling of the injection molding, a start signal of the material injection is input to the input portion,
Subsequently, when the material filling is completed, a material injection end signal is input to the input unit. The difference between the injection start time and the injection end time taken into these input units is calculated and calculated by the filling time calculating unit, compared with the actual filling time and output to the determining unit.

The determination section determines whether or not the actual filling time obtained by the filling time calculation section is within the range of the allowable filling time stored in advance in the allowable filling time setting section. If the actual filling time is outside the permissible filling time, a signal indicating that the product obtained by this molding process is defective is output to a pass / fail display section to alert the worker or the like and to provide a feedback signal. Input to the control unit
I do. Then, it is determined by the determination unit results, when the actual filling time is outside the allowed time, the control device from the determination unit
By outputting a signal for correcting the molding conditions of the injection molding machine via the, the molding quality can be improved while automating the molding process.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an apparatus configuration diagram showing an apparatus for determining the quality of a product of an injection molding machine according to an embodiment of the present invention, and FIG. 2 is a flowchart showing a control procedure of the embodiment. First, a description will be given of a rubber injection molding machine to which a product quality judgment device according to an embodiment of the present invention is applied, but the product quality judgment device of the present invention is not limited to this injection molding machine but other molding machines. Can also be applied.

An injection molding machine according to this embodiment includes a mold, a mold clamping device for opening and closing the mold, and an extruder for injecting a material into the mold, and a plasticizer for plasticizing the material. And a control device for automatically controlling the operation of each of these devices. The mold comprises an upper mold 1a and a lower mold 1b, and these upper and lower molds 1a, 1b
Are combined to form a cavity 8 inside. The upper mold 1a and the lower mold 1b are respectively
It is mounted on die plates 23a and 23b via 1a and 21b and heat insulating panels 22a and 22b, and one die plate is configured to be able to move toward and away from the other die plate. In this embodiment, the lower die plate 2
3b is fixed so that the upper die plate 23a can be moved up and down. The injection port 1 formed in the upper mold 1a
In order for the tip of the nozzle 7 of the extruder 9 to be in contact with the extruder 7, a through hole 24 for passing the nozzle 7 is formed in each of the heating plate 21a, the heat insulating plate 22a and the die plate 23a. The mold clamping device 25 moves the upper and lower die plates toward and away from each other and tightens the molds so as not to be pushed and opened by the injection pressure. It is composed of a tightening cylinder and the like.

The extruder 9 is a device for injecting the molding material from the nozzle 7 into the cavity 8 formed between the upper die 1a and the lower die 1b, and has an injection screw 10 movable inside in the axial direction. Has a heating cylinder 11 inserted therein. The heating cylinder 11 is formed with a flow channel 12 for flowing a heating medium whose temperature is controlled. The molding material introduced into the heating cylinder is heated by the rotation of the injection screw 10 to plasticize the molding material. Is constituted. The drive control of the plasticizing device 19 is performed by feedback control with the control device 20 as shown in FIG.
It is controlled by input and output of signals . Further, a supply port 26 for supplying a molding material into the heating cylinder 11 is connected to the heating cylinder 11.

On the other hand, the injection screw 10 moves in the heating cylinder 11 by moving the injection hydraulic cylinder 14 forward and backward while being rotated by a screw drive hydraulic motor (not shown). The hydraulic device 13 for driving the injection hydraulic cylinder 14 includes a variable displacement pump (not shown) and a direction switching valve (not shown) for switching the pressure feeding direction of the pressure fluid fed from the variable displacement pump. , An electromagnetic relief valve (not shown) for maintaining the pressure of the pressurized fluid at a predetermined pressure
The drive control of the devices constituting the hydraulic device 13 is performed by the control device 20. In FIG. 1, reference numeral “18” denotes a position sensor that detects the position of the injection screw 10 in the axial direction and outputs the detected position to the control device 20.

In order to perform injection molding with such an injection molding machine, the entire extruder 9 is brought close to the upper mold 1a, the nozzle 7 of the extruder is brought into contact with the injection port 17 of the cavity 8, and the hydraulic cylinder for injection is used. The molding material is extruded from the nozzle 7 into the cavity 8 by injecting the injection screw 10 in the nozzle direction by driving the nozzle 14. The injection process includes a filling process of filling the material into the cavity and a pressure-holding process of keeping the injection pressure constant. In the filling process, it is necessary to completely fill the molding material with 100% of the molding material in the cavity. The movement amount of the injection screw 10 according to the molding material is measured in advance. The position sensor 18 detects the filling start position and the filling end position of the molding material, and outputs the detected position to the control device 20 to control the timing of switching to the pressure-holding process. The product quality judgment device of the present invention can also be applied to an injection molding machine that controls the injection speed and pressure in the filling process in multiple stages.

The product quality judgment apparatus of this embodiment has an input section 2 for taking in these signals by utilizing a filling start signal and a filling end signal taken into the control device 20 of the injection molding machine. . Further, the apparatus has a filling time calculating section 3 for calculating a time difference between a filling start signal and a filling end signal taken into the input section 2 to obtain an actual filling time. In the allowable filling time setting unit 4 according to the present embodiment, the reference filling time of the material to be molded is measured in advance for each mold,
This is input as the allowable filling time. For example, when the shortest allowable filling time is 2 seconds and the longest allowable filling time is 4 seconds, the allowable filling time is 2 to 4 seconds.

On the other hand, the judging section 5 compares the filling time in the actual molding process obtained by the filling time calculating section 3 with the allowable filling time inputted in advance to the allowable filling time setting section 4 to determine the actual filling time. It is determined whether the filling time is within the allowable filling time. For example, if the allowable filling time is 2 to 4 seconds and the actual filling time is 5 seconds, the actual time of the filling process exceeds the longest allowable filling time. There is a concern that the product is defective. Therefore, the molded product obtained by this shot is recognized as a defective product, and a signal indicating that the product is defective is output to the pass / fail display unit 6. Conversely, if the actual filling time is within the allowable filling time, a signal indicating that the product is non-defective is output to the pass / fail display unit 6.
Such acceptability display section 6 for displaying quality, such as electronic display panel or warning lamp, the quality of the molded article may be means for urging the operator or the like.

In this embodiment, when a defective product is determined as a result of the determination by the determining unit 5, a feedback signal is output to the control device 20 of the injection molding machine. For example, when the actual filling time is shorter than the shortest allowable filling time, a signal is output to the hydraulic device 13 via the control device 20, and the forward movement speed of the injection hydraulic cylinder 14 is reduced. Conversely, when the actual filling time is longer than the longest allowable filling time, a signal is output to the hydraulic device 13 via the control device 20 to increase the forward moving speed of the injection hydraulic cylinder 14. In the present invention, the output of the feedback signal from the determination unit 5 to the control device 20 may be omitted, and the operator who has viewed the pass / fail display unit 6 may operate the control device 20 of the injection molding machine .

Next, the operation of the apparatus according to the present embodiment will be described with reference to the flowchart shown in FIG. When a viscoelastic material such as rubber is injection-molded, physical properties such as viscosity fluctuate due to a difference between production lots, and the injection filling time also fluctuates. However, an appropriate reference injection filling time according to the material type can be determined in advance.
Runode, the reference filling time is not being influenced by the variation of the above physical properties. In the present embodiment, based on this knowledge, the reference filling time of the material to be molded is measured in advance, and this is input to the allowable filling time setting unit 4 as the allowable filling time (step 1). For example, the shortest allowable filling time t ₀ is 2 seconds, and the longest allowable filling time t ₁ is 4 seconds.

When the filling of the material for injection molding is started, a signal of an injection start position is inputted from the position sensor 18 of the injection molding machine to the control device 20, and a start signal of material injection is inputted from the control device 20 to the input section 2. (Step 2). Subsequently, when the material filling is completed, the signal of the injection end position is input from the position sensor 18 of the injection molding machine to the control device 20, and the material injection end signal is input from the control device 20 to the input unit 2 (step). 3). The time difference t between the injection start time and the injection end time taken in the input unit 2 is calculated by the filling time calculating unit 3 and is output to the determining unit 5 as the actual filling time t (step 4).

In the determination section 5, the actual filling time t obtained by the filling time calculating section 3 is set within the range of the allowable filling time t ₀ , which is input to the allowable filling time setting section 4 in advance.
It determines whether there in t ₁ (step 5). If the actual filling time is 5 seconds or 1 second, it is out of the allowable filling time range.
Then, a signal indicating that the product obtained by this shot is defective is output (step 7).

At the same time, a signal for correcting the molding conditions is output from the determination section 5 to the control device 20 of the injection molding machine (step 8). For example, the actual filling time t
Is shorter than the shortest allowable filling time t ₀ , the injection speed is too fast, and there is a concern about problems such as jetting. Therefore, a signal is output to the hydraulic device 13 via the control device 20 to output the injection hydraulic cylinder. 14, the forward moving speed is reduced. Conversely, if the actual filling time t is longer than the longest allowable filling time t ₁ , a signal such as a flow failure or a joint failure is feared, and a signal is output to the hydraulic device 13 via the control device 20. The forward movement speed of the hydraulic cylinder 14 for injection is increased. If the actual filling time t is within the allowable filling time t _{0 to} t ₁ , a signal indicating that the product is non-defective is output to the acceptability display section (step 6).

As described above, according to the apparatus for determining the quality of a product according to the present embodiment, the quality of the product can be determined based on the filling time, and the molding quality can be improved and the defect rate can be reduced while automating the molding process. Can be. In the above-described embodiment, a specific example in which the product quality judging device of the present invention is provided separately from the injection molding machine has been described. However, the present invention is not limited to this. The device may be configured to incorporate the product quality judgment device of the present invention in the device.

[0024]

[Effect of the Invention] According to the present invention , the control by the control device is performed.
Adjusting the molding conditions of the molding material with a plasticizer
Then, the signal of the start and end of injection of the molding material into the mold is input to the input unit, and the relationship between the time difference between the start and end of injection and the distance of the position sensor is calculated by the filling time calculation unit. To determine whether the actual filling time is within the range of the allowable filling time stored in advance in the allowable filling time setting unit as a function of time in the determination unit. Judgment is made, and if it is outside the allowable time, it is recognized as a defective product and output to the pass / fail display section, so judgment is made only by time
Equipment cost is lower than before.
Can be reduced. Moreover, the molding characteristic curve
Since it is not a complex contrast that contrasts with lines,
Can be up. This is due to the control of the plasticizer.
The molding conditions of the molding material are not changed.
It is. In addition, the quality of the molded product is determined by the determination
Molding can be eliminated, and sorting inspection of molded products is not required
And enable automation. The present invention of claim 2
Inputs the result determined by the determination unit to the control device and
If the case is not abnormal, correct it so that it is normal
Enables dynamic operation. Furthermore, the filling time of the molding material is short
If necessary, correct it and fill it to make it a good product.
It is possible to prevent a defective product from being replaced. Ma
If the filling time is long, stop and stop
Eliminate useless processes and streamline molding cycles
Becomes possible.

[Brief description of the drawings]

FIG. 1 is an apparatus configuration diagram showing an apparatus for determining the quality of a product of an injection molding machine according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a control procedure of the embodiment.

FIG. 3 is an apparatus configuration diagram showing a conventional injection molding machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Die 1a ... Upper mold 1b ... Lower mold 2 ... Input part 3 ... Filling time calculation part 4 ... Allowable filling time setting part 5 ... Judgment part 6 ... Pass / fail display part 7 ... Nozzle 8 ... Cavity 9 ... Extruder 10 ... Injection screw 11 ... Heating cylinder 12 ... Flow path 13 ... Hydraulic device 14 ... Injection hydraulic cylinder 15 ... Variable displacement pump 16 ... Control device 17 ... Injection port 18 ... Position sensor 19 ... Plasticizing device 20 ... Control devices 21a, 21b ... Heating plates 22a, 22b ... Heat insulating plates 23a, 23b ... Die plate 24 ... Through holes 25 ... Mold clamping device

Claims (2)

(57) [Scope of request for utility model registration] An injection component controlled by a control device (20).
A product quality judgment device for a molding machine, comprising:
The screw (10) fills the rubber molding material into the mold (1).
Position detection for detecting the injection start position and injection end position
Sensor (18) and the radiation from the position sensor (18).
An input for capturing the output start position signal and the injection end position signal.
A force part (2) and the injection inputted to the input part (2)
At the start of the start position signal and at the end of the injection end position signal
A charging time calculation unit (3) for calculating the time difference between
Actually measured for each molding material for each of the above-mentioned molds (1)
Enter and store the reference filling time calculated from the molding conditions.
An allowable filling time setting section (4) for setting the allowable filling time.
Reference filling time of the fixed part (4) and the filling time calculating part (3)
In the reference filling time by comparing with the time difference calculated in
A judgment unit (5) for judging whether or not it is good or not;
A signal indicating the quality is displayed in response to the signal determined in (5).
And a pass / fail display unit (6).
The time difference calculated by the charging time calculation unit (3) is before
It will be within the reference filling time of the filling time setting section (4).
To control and maintain the plasticized state of the molding material
Injection molding machine characterized by having
Product quality judgment device. 2. The charging unit according to claim 1, wherein the determining unit includes a charging time calculating unit.
The time difference calculated in (3) is the allowable filling time setting.
When the time is outside the reference filling time of the section (4), the controller (2)
0) input a feedback signal to the reference filling time
And the injection end position.
A pressure-holding step by the control device (20) to which a signal is input.
2. The injection molding method according to claim 1, wherein
Product quality judgment device for molding machines.