JP2023045616A - injection molding method - Google Patents

Abstract

To provide an injection molding method capable of adjusting a metered resin injected and filled into a mold cavity to an appropriate temperature condition.SOLUTION: In an injection molding method for storing a predetermined amount of metered resin in an injection cylinder 11 by adjusting screw speed and back pressure in a metering process, and injecting and filling the metered resin into a mold cavity 23 by adjusting injection speed of a screw 14 in an injection process, temperature measuring means 50 for measuring a filling temperature of the metered resin injected and filled into the mold cavity 23 during the injection process is provided. A filling temperature waveform Z of the metered resin is obtained from measured data of the temperature measuring means 50, and when the filling temperature waveform Z is out of a range of allowable temperatures H and L set for a reference temperature waveform K, temperature correction processing is performed.SELECTED DRAWING: Figure 5

Description

The present invention adjusts the screw rotation speed and back pressure in the metering process to store a predetermined amount of metered resin in the injection cylinder, and adjusts the injection speed of the screw in the injection process to release the metered resin into the mold cavity. It relates to an injection molding method for injection filling inside.

In injection molding, a material supply device is used to supply a resin material into an injection cylinder whose temperature is controlled. The supplied resin material is plasticized by shear heat generated by the rotating motion of the screw having a helical flight and the amount of heat generated by the heater or the like provided in the injection cylinder. stored as a weighing resin in As the resin to be measured is stored, the screw moves backward, and at a predetermined retracted position, the screw stops rotating and the screw position is held (referred to as a measuring process). A resistive force is applied to the backward movement of the screw to adjust the melt-kneadability of the stored molding material (referred to as back pressure control).

Next, the screw is moved forward to inject and fill the measured resin into the mold cavity, a holding pressure process compensates for cooling solidification shrinkage of the molten measured resin, and the molten measured resin is injected into the mold cavity. After cooling and solidifying at , the mold is opened and taken out from the mold cavity as an injection molded product. This series of molding operations is repeated until the required number of molded products is obtained.

Here, the quality of the injection-molded product depends on the stability of the resin temperature, which indicates the degree of melt-kneading of the weighed resin stored in the weighing process, which is the starting point of the molding operation. For example, if the resin temperature fluctuates, the flow state of the metered resin in the mold cavity will fluctuate, resulting in product shorts, resin burrs, product weight fluctuations, appearance defects such as welds and flow marks, voids and unmelted resin. Molding defects due to resin temperature fluctuations such as mixture, product deformation, product dimensional error, surface tension failure, transfer failure, etc. Fluctuations in metered resin are difficult to compensate for in the injection and hold pressure steps following the metering step. For this reason, many proposals have been made over the years regarding the stability of weighing resins.

For example, as shown in Patent Document 1, a temperature sensor is installed in the range from the injection cylinder to the mold, the temperature distribution of the weighed resin is measured during the injection process, and the heater arrangement of the injection cylinder is assigned to determine the heater temperature I am going to correct the settings. Furthermore, in addition to this temperature correction, the number of revolutions of the screw and the back pressure value are also corrected. It is said that this makes it possible to equalize the temperature of the weighing resin.

JP-A-2000-176983

Here, as shown in Patent Document 1, even if the temperature of the metered resin in the injection cylinder can be uniformly adjusted, shear heat is generated when the metered resin flows in the mold cavity in the subsequent injection process. Therefore, the resin temperature changes greatly. This shear heating is related to shear rate and material viscosity. The shear rate is related to the flow rate of the metering resin and the area of the channel through which the metering resin passes. For example, when passing through a narrow gate portion of the flow path, the amount of shear heat generation increases, and the resin temperature rises. In addition, the material viscosity is related to the resin temperature, and as the resin temperature decreases, the material viscosity increases and the amount of shear heat generated also increases. The quality of injection molding is greatly affected by the temperature state of the weighed resin injected and filled into the mold cavity.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an injection molding method capable of adjusting the temperature of a metered resin injected and filled into a mold cavity to an appropriate temperature state.

The injection molding method of the present invention is
In the metering process, the screw rotation speed and back pressure are adjusted to store a predetermined amount of measured resin in the injection cylinder, and in the injection process, the injection speed of the screw is adjusted to inject the measured resin into the mold cavity. In the filling injection molding method,
temperature measuring means for measuring the filling temperature of the weighed resin injected and filled into the mold cavity during the injection process;
A filling temperature waveform of the measured resin is obtained from the measurement data of the temperature measuring means, and temperature correction processing is performed when the filling temperature waveform is out of an allowable temperature range set with respect to the reference temperature waveform. and

In the injection molding method of the present invention,
Preferably, the temperature measuring means is a plurality of temperature sensors incorporated in the injection mold along the flow direction of the metered resin that is injected and filled from the gate of the mold cavity.

Further, in the injection molding method of the present invention,
It is preferable that the temperature measuring means is a thermo camera that opens the mold cavity and takes a thermal image of the measured resin after a predetermined time has elapsed since injection filling of the measured resin is completed.

Furthermore, in the injection molding method of the present invention,
In the temperature correction process, a position where the filling temperature waveform is out of the allowable temperature range is set as a correction position, the correction position is converted to the screw position during the injection process, and the converted screw position is converted to the correction screw position. and correcting the screw rotational speed in the metering step based on the corrected screw position.

Further, in the injection molding method of the present invention,
In the temperature correction process, a position where the filling temperature waveform is out of the allowable temperature range is set as a correction position, the correction position is converted to the screw position during the injection process, and the converted screw position is converted to the correction screw position. and a correction of said back pressure of said metering step based on said corrected screw position.

According to the present invention, it is possible to provide an injection molding method capable of adjusting the temperature of the metered resin injected and filled into the mold cavity to an appropriate temperature state.

1 is a conceptual diagram of an injection molding machine according to an embodiment of the present invention; FIG. FIG. 2 is a conceptual diagram of temperature measuring means according to the embodiment of the present invention; 1. It is a figure which shows the molding operation using the injection molding apparatus shown in FIG. FIG. 4 is a diagram showing the flow state of the metered resin in the mold cavity; It is a figure which shows the injection molding method which concerns on embodiment of this invention.

Preferred embodiments for carrying out the present invention will be described below with reference to the drawings. In addition, the following embodiments do not limit the invention according to each claim. In addition, not all combinations of features described in the embodiments are essential for the solutions of the inventions according to the respective claims. In addition, in this embodiment, the scale and dimensions of each component may be exaggerated, and some components may be omitted.

[Injection molding machine]
First, an injection molding machine according to an embodiment of the present invention will be described with reference to FIG. In the following description, the injection molding machine according to the embodiment of the present invention is based on a horizontal injection molding machine, but the present invention is not limited to this. An injection molding machine 100 shown in FIG. 1 includes an injection device 10 , an injection mold 20 , an injection drive section 30 and an injection control section 40 .

The injection device 10 includes a cylindrical injection cylinder 11 and a screw 14 arranged inside the injection cylinder 11 . The injection control unit 40 operates the injection driving unit 30 to adjust the rotation and forward/backward movement of the screw 14 . Here, regarding the movement of the screw 14, the direction closer to the injection molding die 10 is forward F, the movement forward F is forward movement, the direction away from the injection molding die 10 is backward B, and the movement backward B is backward movement. Define. Further, the injection device 10 is operated to connect and separate the injection device 10 and the injection molding die 20 by a driving device (not shown) or the like, and is in a connected state when injection molding is performed.

A plurality of heaters 12 are arranged on the outer peripheral surface of the injection cylinder 11 at predetermined intervals, and the temperature of the heaters 12 is controlled by a temperature control device (not shown) to adjust the temperature of the injection cylinder 11 to a predetermined temperature. A material hopper 13 is provided behind the injection cylinder 11, and a resin material is supplied from the material hopper 13 into the injection cylinder 11 by a material supply device or the like (not shown).

The screw 14 has a helical flight 15 extending from the rear B to the front F. The helical direction and angle of the flight 15 are set so that the resin material supplied from the material hopper 13 can be rotationally transported forward F with respect to the rotational direction of the screw 14 . As shown in FIG. 1, one flight 15 is arranged at a constant interval and at a constant angle, but the arrangement is not limited to this. It can also be an array of Alternatively, a plurality of flights 15 may be arranged only in a partial range of the screw 14 .

The screw 14 has a cylindrical shape whose diameter increases stepwise from the rear B to the front F. That is, the volume of the gap between the screw 14 and the injection cylinder 11 is set so as to gradually decrease from the rear B to the front F, for example, the transport zone, the compression zone, and the melting zone. As a result, the resin material supplied from the material hopper 13 is transported forward by the rotational motion of the screw 14 and the flight 15, and the reduction in volume causes the compression action and shear heat generation to act on the resin material. Due to the synergistic effect, it is melted in stages (called plasticization), and molten resin is generated toward the front F of the screw 14. Molten resin is stored in a storage area 17 on the front side F of the screw 14 (referred to as a weighed resin). As the amount of resin to be measured increases, the screw 14 retreats to the rear B side, stops rotating at a predetermined retreated position, and holds the stopped position (referred to as a metering process). The backward movement of the screw 14 is restricted (referred to as metering back pressure) to adjust the melt-kneadability of the molding material (referred to as back pressure control). In the injection process, the screw 14 is advanced to inject and fill the metered resin toward the injection mold 20 . During this injection process, the flow path in the backflow prevention device 16 is closed.

In the injection molding die 20, a fixed die 21 and a movable die 22 are supported by a die clamping device (not shown), and the movable die 22 moves forward and backward with respect to the fixed die 21 by the die clamping device. Here, regarding the motion of the movable mold 22, the motion of approaching the fixed mold 21 is defined as the mold closing motion, and the motion of moving away from the fixed mold 21 is defined as the mold opening motion. In addition, the mold touch point is the position where the fixed mold 21 and the movable mold 22 abut during the mold closing operation, the mold clamping operation is the movement in the direction of the mold closing operation from the mold touch point, and the completion position of the mold clamping operation is The mold clamping limit and the operation from the mold clamping limit to the mold touch point are defined as the step-down operation. A mold cavity 23 is formed within the range of the mold clamping limit from the mold touch point. In addition, the fixed mold 21 includes a resin channel 24 through which the resin material flows, a valve gate 25 that opens and closes the resin channel 24 , and a gate 26 that connects the resin channel 24 to the mold cavity 23 . Prepare. The resin flow path 24 is adjusted to a predetermined temperature in the same manner as the injection cylinder 11 .

Here, as a resin material used for injection molding, for example, in automobile interior parts, a thermoplastic resin such as polypropylene (PP) resin or polyethylene (PE) resin is added with a coloring agent such as black, red, or blue. It is common to adjust the color tone of the part. In addition, plasticizers that give flexibility to thermoplastic resins, nucleating agents and clarifying agents that control the degree of crystallinity in crystalline resins, flame retardants that suppress combustion, and antistatic agents that suppress static electricity. , lubricants that improve fluidity and releasability, weathering agents and UV deterioration inhibitors that suppress deterioration due to ultraviolet rays, and reinforcing agents such as glass fibers and carbon fibers. In addition, general-purpose resins such as polypropylene (PP) resin and polyethylene (PE) resin, engineering resins such as polyamide (PA) resin and polycarbonate (PC) resin, polyphenylene sulfide (PPS) resin and polyether ether ketone (PEEK) resin, etc. A thermoplastic resin such as a super engineering resin is selected as appropriate. A combination of thermoplastic resin and additives is called a resin material. Thermosetting resins such as phenol (PF) resins and melanin (MF) resins may be used instead of thermoplastic resins.

[Temperature measuring means]
Next, temperature measuring means for measuring the filling temperature of the measured resin injected and filled into the mold cavity in the injection process according to the embodiment of the present invention will be described with reference to FIG.

First, as shown in FIG. 2(a), as the temperature measuring means 50, a plurality of temperature sensors 51 are attached to the movable mold 22 from the gate 26 of the mold cavity 23 along the flow direction of the measured resin injected and filled. to be placed. The temperature data measured by the plurality of temperature sensors 51 are edited by the temperature receiving section 52 into the filling temperature of the weighed resin during the injection process, and the edited data is transmitted to the injection control section 40 . Although the temperature sensor 51 is arranged along the mold cavity 23 below the gate 26 in FIG. A sensor 51 may be arranged. Also, the temperature sensor 51 may be arranged on the stationary mold 21 or may be arranged at a certain distance from the mold cavity 23 .

Further, as shown in FIG. 2(b), a thermo camera 54 for capturing a thermal image is used as the temperature measuring means 50. As shown in FIG. Specifically, after the mold cavity 23 is injected and filled with the measured resin, the movable mold 22 is opened at an arbitrary timing, and the molded product 53 in which the measured resin has not completely cooled and solidified is thermostatted. A camera 54 takes a picture. The thermal image data captured by the thermo camera 54 is edited by the image receiving section 55 as the filling temperature of the weighed resin during the injection process, and the edited data is transmitted to the injection control section 40 . In addition, the means shown in FIG. 2(b) is less accurate than the means shown in FIG. It is suitable for grasping the temperature. Also, in FIG. 2B, one thermo camera 54 is used for temperature measurement, but a plurality of thermo cameras 54 may be used. Further, the temperature was measured while the molded product 53 was attached to the stationary mold 21, but the temperature may be measured while the molded product 53 is being transported by a robot or the like.

In addition to these means, for example, the filling temperature during the injection process obtained from CAE flow analysis data of a CAE flow analysis method may be used. In this case, the positional relationship between the filling temperature and the screw 14 can be easily displayed, and can be used for temperature correction processing, which will be described later. Moreover, these temperature measuring means may be used alone, or may be used in combination as necessary. If the temperature measuring means is provided closer to the injection device 10 than the resin flow path 24, shear heat is generated when the metered resin passes through the resin flow path 24 and the gate 26, which is not preferable.

[Injection molding operation]
Next, the injection molding operation according to the embodiment of the present invention will be explained using FIG. FIG. 3(a) shows a cross-sectional view of the injection cylinder 11 and the injection mold 20 in the weighing process, and FIG. 3(b) shows the injection process in the injection process with the horizontal axis representing the screw position S and the vertical axis representing the injection speed. Indicates a control pattern.

First, as shown in FIG. 3(a), the injection control unit is operated based on a weighing control pattern in which weighing conditions such as the heating temperature of the injection cylinder 11, the number of revolutions of the screw 14, the back pressure, and the weighing completion position KE are set. 40 operates the injection drive unit 30 to start the weighing process. When the position of the screw 14 reaches the weighing completion position KE, a predetermined amount of weighed resin is stored in the storage area 17, and the weighing process ends. During the weighing process, the valve gate 25 is closed. Also, the metering completion position KE becomes the injection start position SS of the subsequent injection process (KE=SS).

In the injection process, as shown in FIG. 3(b), the injection control unit 40 controls the injection drive unit based on an injection control pattern with multiple injection speeds set according to the characteristics of the resin material, the shape of the mold cavity 23, and the like. 30 is operated to start the injection process. The screw 11 advances from the injection start position SS toward the injection holding pressure switching position VP, and the mold cavity 23 is injected and filled with the measured resin. After the screw position S reaches the injection/holding pressure switching position VP, the process shifts to a holding pressure process to compensate for the cooling solidification shrinkage amount of the weighed resin. is removed from the mold cavity 23. During the injection process and pressure holding process, the valve gate 25 is open. In addition, in FIG. 3B, the injection speed injection control pattern is used, but the injection control pattern is not limited to this, and for example, the injection pressure injection control pattern may be used. In this case, the injection speed changes in conjunction with the setting of the injection pressure.

Here, in the injection process, the measured resin is greatly affected by shear heat generation when the measured resin flows in the range from the resin flow path 24 to the mold cavity 23 . This shear heat generation is related to the shear rate and the material viscosity, and the higher the shear rate and the higher the material viscosity, the greater the shear heat generation.

The shear rate is related to the flow rate of the metering resin and the area of the flow path through which the metering resin passes. For example, when the resin to be measured passes through the valve gate 25 or gate 26, which has the smallest flow path area, shear heat generation increases, and as a result, the temperature of the resin to be measured after passage rises significantly. Furthermore, the shear heat generation varies greatly depending on the injection speed of the injection control pattern. For example, as shown in FIG. 3(b), shear heat generation is the largest in region B where high speed injection is set, followed by region A where medium speed injection is set and shear heat generation is the largest in region C where low speed injection is set. become smaller. As a result, even within the range of injection filling for one shot, the temperature of the metered resin greatly fluctuates depending on the magnitude of shear heat generation accompanying changes in the injection speed.

Further, the material viscosity is related to the resin temperature. As the resin temperature decreases, the material viscosity increases and the shear heat generation also increases. For example, in region C, the time elapsed from the start of injection filling is longer than in regions A and B, and the injection mold is adjusted to a temperature clearly lower than the temperature of the metering resin. As it flows through the mold cavity 20, the metered resin is cooled to reduce its temperature. When this happens, the viscosity of the material increases and the heat generated by shear increases, so the temperature of the weighed resin rises. However, the low speed injection setting keeps the shear heating low, and eventually we come to the conclusion that it is correct to measure the temperature distribution of the metered resin injected and filled into the actual mold cavity 23 . In other words, for quality control of injection molded products, temperature control of the measured resin injected into the mold cavity 23 is more correct than temperature control of the measured resin stored in the injection cylinder 11 .

[Injection molding method]
Next, an injection molding method according to an embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG. FIG. 4 shows the injection filling condition of the metered resin in the mold cavity 23 during the injection process. Also, FIG. 5 shows a procedure for temperature correction processing of the weighed resin based on the filling temperature during the injection process. Here, the description will be made from the point where the injection process is started based on the injection control pattern shown in FIG. 3B after the weighing process shown in FIG. 3A is completed.

First, as shown in FIG. 4( a ), due to the forward movement of the screw 14 , the metered resin in the storage area 17 passes through the resin flow path 24 , the opened valve gate 25 and the gate 26 to the mold cavity 23 . Injection filled inside. As the screw 14 moves forward, the inside of the mold cavity 23 is filled with the resin to be measured. Next, as shown in FIG. 4(b), when the screw 15 reaches the injection/holding pressure switching position VP, the injection process is completed, and the pressure holding process is switched to press the screw 14 with a predetermined pressure to carry out holding pressure filling. conduct. At the time of completion of this injection process, the inside of the mold cavity 23 is filled with the metered resin, and the base of the molded product 53 is obtained. During the injection process and pressure holding process, the valve gate 25 is open. During this injection process, the temperature measuring means shown in FIG. 2 is used to measure the filling temperature of the metered resin injected and filled into the mold cavity 23 . Also, the metered resin in the mold cavity 23 is filled from the gate 26 (injection fill position G) and flows toward the final injection fill position M.

Next, from the measurement data of the filling temperature by the injection control unit 40, as shown in FIG. dashed line). The reference temperature waveform K (solid line in the figure) that can obtain good product molding and the upper and lower limit allowable temperatures (H, L) are superimposed on this. The reference temperature waveform K and the allowable temperature (H, L) are set in the injection control unit 40, for example, based on past injection molding mass production results. Alternatively, it may be obtained from the calculation result of CAE flow analysis. In FIG. 5(a), the permissible temperature (H, L) is set to two points, upper and lower limits, but is not limited to this. Also good. Alternatively, the number of set points may be selected according to the weighing control pattern of the weighing process.

If the filling temperature waveform Z is within the range of allowable temperatures (H, L) for obtaining good product molding set with respect to the reference temperature waveform, it is assumed that stable production of good product molding is guaranteed, and correction is performed. continue the injection molding operation. If the filling temperature waveform Z is out of the allowable temperature range (H, L), it is considered difficult to stably produce non-defective products, and the following temperature correction processing is performed.

First, injection filling positions where the filling temperature waveform Z and the allowable values (H, L) intersect are defined as correction positions (S1 to S3). Next, the corrected positions (S1-S3) are converted to positions of the screws 14 during the injection process. For this conversion, for example, CAE flow analysis may be used, but it is preferable to use a short shot filling method that reproduces the actual injection process by dividing it. In the short shot filling method, the injection process is performed in the range from the weighing completion position KE shown in FIG. 3(a) to the injection holding pressure switching position VP shown in FIG. is a means for obtaining a molded product 53 in a short shot state by stopping the screw 14 in the middle. By finely dividing the intermediate stop position of the screw 14, the position of the screw 14 during the injection process and the flow state of the measured resin in the mold cavity 23 can be accurately grasped. Therefore, it is a means widely used in the field of injection molding. The position of the screw 14 during the injection process is also the position of the screw 14 during the metering process.

Next, as shown in FIG. 5B, a weighing control pattern in which the corrected screw positions (HS1 to HS3) are the corrected positions (S1 to S3) after conversion, and the horizontal axis is the position of the screw 14 during the weighing process. is superimposed on the graph showing , and the correction pattern for the temperature correction process is set. Here, the number of screw revolutions and the back pressure during the weighing process were used as adjustment items for the temperature correction process. This was selected from the viewpoint of immediate effect and certainty, with the aim of ensuring stable production of good products from the next shot by predicting the quality of the injection-molded product in the injection process and immediately performing appropriate correction processing in the weighing process. . It should be noted that the means for adjusting the temperature of the injection cylinder 11 by adjusting the heater 12 requires time to adjust the temperature, and immediate effect cannot be expected, and the temperature of the weighed resin in the narrow range of the storage area 17 needs to be finely adjusted. is extremely difficult, it is not preferred.

First, temperature correction processing using the screw rotation speed will be described. In the range from the metering start position KS to the corrected screw position HS1, the filling temperature waveform Z is within the range of allowable values (H, L), so the screw rotation speed N0 of the preset metering control pattern is used. In the range from the corrected screw positions HS1 to HS2, the filled resin temperature waveform Z exceeds the upper limit allowable value H, so the screw rotation speed N1 is lowered (N1<N0) in order to lower the temperature of the metered resin. This reduces the shear heating due to the rotating action of the screw 14, resulting in a lower temperature metered resin stock. In the range from the corrected screw positions HS2 to HS3, the filling temperature waveform Z is within the range of allowable values (H, L), so the screw rotation speed N0 of the metering control pattern set in advance is used. In the range from the correction screw position HS3 to the metering completion position KE, the filled resin temperature waveform Z is lower than the lower limit allowable value L. Therefore, in order to raise the temperature of the metered resin, the screw rotation speed N2 is increased (N2>N0 ). This increases shear heating due to the rotational movement of the screw 14, resulting in storage of high temperature metered resin. By performing these temperature correction processes in the weighing process, the temperature of the weighed resin injected and filled into the mold cavity 23 can be optimized.

Next, temperature correction processing using back pressure will be described. In this case also, similarly to the screw rotation speed, based on the allowable values (H, L) of the filling temperature waveform Z and the reference waveform K, and the corrected screw positions (HS1 to HS3), Then, the back pressure BP0 of the metering control pattern set in advance without correction is assumed. If it is higher than the allowable value H, the metering back pressure BP1 is reduced (BP1<BP0) in order to reduce shear heating resulting in a lower temperature metered resin. If it is lower than the allowable value L, the metering back pressure BP2 is increased (BP2>BP0) in order to increase the shear heating and result in a higher temperature metered resin. A temperature correction process using back pressure is also performed in the measuring process, and the temperature of the measured resin injected and filled into the mold cavity 23 can be optimized.

Here, temperature correction processing may be performed by combining the screw rotation speed and the back pressure. For example, if the number of rotations of the screw 14 is excessively increased in order to obtain a high-temperature metered resin, resin material that is not completely melted (referred to as unmelted resin) is mixed with the metered resin, resulting in molding problems such as foreign matter contamination. It may become defective. In this case, the rotational speed of the screw 14 is reduced to suppress the generation of unmelted resin, and the shortage of shear heat generation is compensated by increasing the back pressure. Also, if an excessively high back pressure is set in an attempt to obtain high shear heat generation, the storage speed of the weighed resin slows down, and the weighing process takes a long time, resulting in a significant drop in productivity. In this case, the back pressure is slightly lowered and the number of revolutions of the screw 14 is increased to compensate for shear heat generation and shorten the time required for the weighing process.

[effect]
Thus, by correcting the metering control pattern in the metering process based on the filling temperature of the metered resin during the injection process, the metered resin injected and filled into the mold cavity can be adjusted to an appropriate state. As a result, stable production of high-quality injection molded products can be ensured. Further, the correction process can be performed in the weighing process following the injection process, and the injection molding of the next shot can be performed in a state in which the correction process has been performed. As a result, continuous production of defective products can be avoided, and injection molding with high production efficiency can be provided.

Although the preferred embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the ranges described in the above-described embodiments. Various modifications or improvements can be added to the above embodiments.

REFERENCE SIGNS LIST 100 injection molding machine 10 injection device 11 injection cylinder 12 heater 13 material hopper 14 screw 15 flight 16 backflow prevention device 17 storage area F front B rear 20 injection mold 21 fixed mold 22 movable mold 23 mold cavity 24 resin flow path 25 valve gate 26 gate 30 injection drive section 40 injection control section 50 temperature measurement means 51 temperature sensor 52 temperature reception section 53 molded product 54 thermo camera 55 image reception section KE measurement completion position KS measurement start position SS injection start position VP injection maintenance Pressure switching position A, B, C Region G, M Injection filling position Z Filling temperature waveform K Reference temperature waveform H, L Allowable temperature S1 to S3 Correction position HS1 to HS3 Correction screw position N0 to N2 Screw rotation speed BP0 to BP2 Back pressure

Claims (5)

In the metering process, the screw rotation speed and back pressure are adjusted to store a predetermined amount of measured resin in the injection cylinder, and in the injection process, the injection speed of the screw is adjusted to inject the measured resin into the mold cavity. In the filling injection molding method,
temperature measuring means for measuring the filling temperature of the weighed resin injected and filled into the mold cavity during the injection process;
A filling temperature waveform of the measured resin is obtained from the measurement data of the temperature measuring means, and temperature correction processing is performed when the filling temperature waveform is out of an allowable temperature range set with respect to the reference temperature waveform. and injection molding method. 2. The injection molding method according to claim 1, wherein said temperature measuring means is a plurality of temperature sensors incorporated in said injection mold along the flow direction of said metered resin injected and filled from said mold cavity gate. . 2. The temperature measuring means according to claim 1, wherein said temperature measuring means is a thermo camera that opens said mold cavity and takes a thermal image of said resin to be measured after a predetermined time has passed since the completion of injection filling of said resin to be measured. injection molding method. In the temperature correction process, a position where the filling temperature waveform is out of the allowable temperature range is set as a correction position, the correction position is converted to the screw position during the injection process, and the converted screw position is converted to the correction screw position. 4. The injection molding method according to any one of claims 1 to 3, wherein said screw rotational speed in said measuring step is corrected based on said corrected screw position. In the temperature correction process, a position where the filling temperature waveform is out of the allowable temperature range is set as a correction position, the correction position is converted to the screw position during the injection process, and the converted screw position is converted to the correction screw position. 4. The injection molding method according to any one of claims 1 to 3, wherein the back pressure in the metering step is corrected based on the corrected screw position.

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