JP3497013B2 - Mold temperature controller - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold temperature controller attached to a plastic molding machine and, more particularly, to a mold temperature control apparatus for controlling the molding temperature of a plastic molding mold to a target temperature quickly and accurately. The present invention relates to a mold temperature controller.

[0002]

2. Description of the Related Art In order to efficiently and stably produce good plastic molded products using a plastic molding machine, a plastic molding machine has conventionally been used with a mold temperature controller. There is. FIG. 4 is a schematic diagram showing a conventional mold temperature controller.

Referring to FIG. 4, the mold temperature controller Xc is attached to the plastic molding mold 1 of the plastic molding machine Y1, and circulates through the temperature sensor S30 and the plastic molding mold 1. Heating the temperature control medium F
It has a configuration in which a medium temperature adjusting device 2 for cooling and a temperature controller 3 for controlling the temperature of the temperature adjusting medium F are provided, and the temperature sensor S30 is a fixed mold cavity of the plastic molding mold 1. It is embedded in 1a (also called a mold core). In FIG. 4, reference numeral 1b represents a movable mold cavity of the plastic molding mold 1.

The medium temperature adjusting device 2 is provided with a medium storage tank 5 having a heater 2A that can be controlled to be turned on and off, and a temperature control medium F is accommodated in the medium storage tank 5. Each of the mold cavity 1a and the mold cavity 1b and the medium storage tank 5 includes a medium forward flow path 4a and a medium return flow path 4a.
b, a pump P is provided in the medium outward flow path 4a, and the mold cavity 1a and the medium storage tank 5 are connected to each other.
Between the mold cavity 1b and the medium storage tank 5
The temperature control medium F is circulated between and.

Further, the medium storage tank 5 is connected to a medium supply passage 2b having a water supply valve 2B for supplying or replenishing the temperature control medium F to the medium storage tank 5 from the outside. When the water supply valve 2B is opened, the low-temperature or normal-temperature temperature control medium F flows into the medium storage tank 5 through the medium supply flow path 2b, and the temperature control medium F in the medium storage tank 5 The temperature can be lowered.
Further, a drainage channel 6 for discharging the temperature control medium F to the outside is connected to the medium storage tank 5, and the drainage channel 6 is used for adjusting the water level of the temperature control medium F in the medium storage tank 5. The float switch 6a is interposed.

When molding a plastic molded product using such a mold temperature controller Xc, the temperature controller 3 measures the measurement value T30 of the temperature sensor S30 embedded in the plastic molding mold 1. Take in as a temperature signal, heater 2A for heating, pump P, water supply valve 2B,
By controlling the float switch 6a to control the temperature of the temperature adjusting medium F to a predetermined target temperature, the surface temperature of the molding surface of the plastic molding die is controlled to the target temperature (see FIG. 5).

[0007]

However, in such a mold temperature controller Xc, the molding surface 1S of the plastic molding die 1 is measured based on the measurement value of the temperature sensor S30 embedded in the plastic molding die 1. Since the temperature is controlled to the target temperature, the molding surface 1S of the plastic molding die 1
There is a problem that the actual surface temperature and the measured value of the temperature sensor S30 have a temperature difference, and cannot be accurately controlled. Therefore, in the case of a large temperature shift,
As shown in FIG.
Alternatively, a medium return temperature sensor S2 is provided in the medium return channel 4b, and the medium temperature is set to a predetermined target temperature based on the temperature detected by the medium temperature sensor S1 and the medium temperature sensor S2. A method of switching to an indirect control method of maintaining and controlling the surface temperature of the molding surface 1S of the plastic molding die 1 to a target temperature is adopted. However, since this indirect control system controls based on the temperature of the temperature control medium F, the temperature of the temperature control medium F is changed in accordance with the actual change of the surface temperature of the molding surface 1S of the plastic molding die 1. Again, it was not enough to accurately control the target temperature.

Therefore, in order to solve such a problem, the deviation between the measured value of the temperature sensor S30 and the actual surface temperature of the molding surface 1S is empirically predicted and corrected to calculate the estimated value. A complicated control of controlling the temperature of the temperature control medium F circulated and supplied to the plastic molding die 1 to a target temperature based on the estimated value has been attempted, and the molding surface 1S is controlled based on the estimated value. The method of controlling the surface temperature of the target to a target temperature has problems such as different predictive factors and correction data depending on the shape and size of the mold, the molding resin, etc. There was a problem that it was difficult to analyze the values.

By the way, in the mold temperature controller Xc of this type, the plastic molding work (operation) is smoothly progressing,
In the steady operation state, the heat input from the plastic (resin) and the cooling by the temperature control medium F are balanced, so the set temperature of the temperature control medium F is the heat input from the molten plastic (resin). Although it is set to a value lower than the optimum temperature of the plastic molding die 1 in anticipation (forecasting), the die temperature controller Kc or the plastic molding machine Y1 fails, or the raw material (resin) of the plastic molded product If the plastic molding work (operation) is temporarily interrupted in the event that the product is out of supply or the plastic molded product is defective, the plastic molded product continuously supplied to the plastic molding die 1 The supply of the raw material (molten resin) of is interrupted.

When the supply of the raw material (molten resin) to the plastic molding die 1 is interrupted in this way,
As a result of no heat supply to the plastic molding die 1, the surface temperature of the molding surface 1S of the plastic molding die 1 is supercooled to the set temperature of the temperature adjustment medium F. However, since the temperature sensor S30 is embedded in the plastic molding die 1, the temperature sensor S30 is affected by the heat storage effect of the molding die 1, detects a temperature higher than the actual surface temperature of the molding surface 1S, and measures the measured value. Since it is transmitted to the temperature / temperature controller 3 as a temperature measurement signal, overcooling of the molding surface 1S is not compensated,
When the plastic molding operation (operation) is restarted in this state, all of the molten plastic supplied to the plastic molding die 1 becomes low-temperature molded products,
We will manufacture defective products.

In order to eliminate the occurrence of such defective products, conventionally, measures such as correcting the set temperature of the temperature adjusting medium F by the arithmetic processing means (computer) have been taken. More specifically, for example, when the plastic molding operation (operation) is interrupted for several minutes, the set temperature of the temperature adjustment medium F is corrected upward by the arithmetic processing means (computer) several times, and the plastic molding is performed. Work has been attempted to make corrections until the temperature of the mold 1 becomes optimum, but such correction data changes subtly depending on the size of the mold, the molding resin, etc., so it is extremely complicated and difficult. It is working.

The present invention has been made to solve the above problems. The first object of the present invention is to measure the temperature change of the molding surface of the plastic molding die more accurately with a simple structure, and to measure the surface temperature of the molding surface of the molding die of the plastic molding machine with higher accuracy. An object of the present invention is to provide a mold temperature controller that can control the target temperature. A second object of the present invention is to provide a mold temperature controller that can reduce the generation of defective plastic molded products even when the plastic molding work is interrupted when the plastic molding work is restarted.

[0013]

A mold temperature controller according to claim 1 is a non-contact type temperature controller for a plastic molding mold.
Temperature sensor is installed and the temperature sensor
Input the measured value as a temperature measurement signal into the temperature controller to
Mold temperature configured to control the preparation medium to a predetermined target temperature
Of the plastic molding die in the
The period during which the cavity and the fixed cavity are clamped
Inside, at a position close to the joint surface of both cavities,
While placing the non-contact type temperature sensor,
The tee is separated from the fixed cavity and the molded product is
The non-contact type temperature sensor is used during the period when the temperature sensor is being taken out.
Of the movable cavity or the fixed cavity
Temperature sensor position control that moves to a position close to the molding surface
It is characterized by having means.

The temperature sensor is installed near the joint surface between the fixed mold cavity and the movable mold cavity, for example, when the plastic molding die is clamped. When the plastic molded product is separated from the mold, it may be installed at a position close to the surface of the plastic molded product. In order to achieve this object, non-contact type sensors may be arranged at these positions in advance, and the non-contact type sensor may be switched according to the operation of the mold to change the measurement point.

Further, in the mold temperature controller according to claim 2, the non-contact type temperature sensor is a plastic molding mold.
Close to the joining surface of the movable cavity and the fixed cavity of the mold.
Contact position and the movable cavity or fixed
It is installed close to the molding surface of the cavity.
The movable cavity of the plastic molding die above.
The above is possible while the constant cavity is clamped.
In the position close to the joint surface of both moving and fixed cavities
Use the non-contact temperature sensor installed and
The movable cavity is separated from the fixed cavity above.
During the period when the molded product is taken out,
Proximity or near the molding surface of the fixed cavity
Use the non-contact type temperature sensor installed at the position
Temperature is measured and the temperature control medium is controlled to a predetermined target temperature.
I'm done.

[0016]

The operation achieved by the constitution of the present invention is as follows. Since a non-contact type temperature sensor is used, the measurement point is placed in the air that is in non-contact with the molded product, so there is no effect due to the heat storage effect of the plastic molding die. Moreover, the measurement point of the non-contact temperature sensor is
Since it is in the air at a certain distance from the molding surface, a temperature lower than the actual surface temperature of the molding surface is detected due to thermal diffusion, so that the problem of supercooling of the surface temperature of the molding surface is solved.

Further, the measurement point of one non-contact type temperature sensor can be moved by the temperature sensor position control means. That is, during the period when the plastic molding die is clamped, it is located at a position close to the clamped joint surface of the molding die, and when the plastic molded product is taken out, the open plastic is opened. Since the temperature can be measured by moving it to a position close to the molding surface of the molding die, the temperature of the temperature control medium of the plastic molding die can be accurately controlled by the target temperature according to the control operation of the die.

[0018]

EXAMPLES The present invention will now be described in more detail by way of examples. (Embodiment 1) FIG. 1 shows a mold temperature controller 1 according to the present invention.
It is a block diagram which shows an Example schematically.

Referring to FIG. 1, the mold temperature controller X is attached to the plastic molding mold 1 of the plastic molding machine Y and includes a non-contact type temperature sensor (infrared sensor) S3 and a plastic. A medium temperature adjusting device 2 for heating and cooling the temperature control medium F circulating and circulating in the molding die 1 and a temperature controller 3 for controlling the temperature of the temperature control medium F are provided. 1b in FIG.
Is a movable mold cavity.

The mold temperature controller X is different from the conventional mold temperature controller Xc in that it uses a non-contact type temperature sensor (infrared sensor) S3. More specifically, in this mold temperature controller X, the non-contact type temperature sensor S3 is provided at a predetermined distance from the molding surface 1S of the fixed mold cavity 1a of the plastic molding mold 1. In this position, the temperature of the molding surface 1S of the plastic molding die 1 can be directly detected.

The medium temperature adjusting device 2 is provided with a medium storage tank 5 having a heater 2A which can be controlled to be turned on and off, and a temperature control medium F is accommodated in the medium storage tank 5. Each of the mold cavity 1a and the mold cavity 1b and the medium storage tank 5 are connected by a medium forward flow path 4a and a medium return flow path 4b, and a pump P is provided in the medium forward flow path 4a. The mold cavity 1a and the medium storage tank 5
Between the mold cavity 1b and the medium storage tank 5
The temperature control medium F is circulated between and.

Further, the medium storage tank 5 is connected with a medium supply passage 2b for supplying or replenishing the temperature control medium F to the medium storage tank 5 from the outside, and further, the medium supply passage 2b is connected with the medium supply passage 2b.
The water supply valve 2B is provided, and when the water supply valve 2B is opened, the low-temperature or normal-temperature temperature control medium F flows into the medium storage tank 5 through the medium supply flow path 2b, and the medium storage tank 5 The temperature of the temperature control medium F in the inside can be lowered, and a drainage channel 6 for discharging the temperature control medium F to the outside is connected to the medium storage tank 5. A float switch 6 a for adjusting the water level of the temperature control medium F in the medium storage tank 5 is interposed in the flow path 6.

The temperature controller 3 is mainly composed of a microprocessor (CPU) (not shown), a read-only memory (ROM) (not shown) in which a control program is written, and data is written at any time. / Read / write memory (RAM) (not shown), input / output interface (not shown), data bus, address bus, and communication as a communication means for communicating with an external computer An interface (not shown) is provided.

Non-contact type temperature sensor (infrared sensor) S
3, the medium feeding temperature sensor S1, the medium returning temperature sensor S2, the water supply valve (electromagnetic valve) 2B, the float switch 6a, and the pump P are electrically connected to an arithmetic processing unit (not shown) that controls the temperature controller 3. It is connected. According to such a configuration, the measurement value T3 detected by the non-contact temperature sensor (infrared sensor) S3 is sent to the temperature controller 3 as a temperature measurement signal, and the temperature controller 3 stores the control program stored in advance and And / or operates to the heater 2A for heating, the water supply valve 2B, the float switch 6a and / or the pump P in accordance with a command from an external input device (not shown) of an arithmetic processing unit (not shown) connected to the temperature controller 3. Each of the heating heater 2A, the water supply valve (electromagnetic valve) 2B, the float switch 6a, and / or the pump P that transmits a signal can operate based on the operation signal.

When molding a plastic molded product using the mold temperature controller X, turn on the switch SW,
The mold temperature controller X is driven. Temperature controller 3
Takes in the measurement value T3 of the non-contact type temperature sensor S3 as a temperature measurement signal, controls the heater 2A for heating, the pump P, the water supply valve 2B, and the float switch 6a to set the temperature of the temperature control medium F to a predetermined target. By controlling the temperature, the surface temperature of the molding surface of the plastic molding die is controlled to the target temperature (see FIG. 5).

If necessary, an arithmetic processing unit (not shown) is connected to the temperature controller 3, and an external input unit (not shown) is used to control a target temperature and a control constant (for example, PID) of the surface temperature of the molding surface 1S. In the case of control, a proportional control constant, a derivative control constant, an integral control constant) may be input. It should be noted that this operation can be performed in advance, and in such a case, such information is stored in a processing unit (not shown).
It should be stored in the storage device.

In this mold temperature controller X, in particular, a non-contact type temperature sensor S3 is arranged near the surface 1S of the plastic molding mold 1, and the temperature controller 3 uses the measurement value of the temperature sensor S3 as a temperature measurement signal. Since the temperature-adjusting solvent body F is controlled to a predetermined target temperature by inputting to, it is not necessary to embed the temperature sensor S30 in the plastic molding die 1 as compared with the conventional die temperature controller Kc. The contact type temperature sensor S3 can be installed easily, and the plastic molding die 1 of the plastic molding machine Y can be easily changed.

Further, in this mold temperature controller X, since the non-contact type temperature sensor S3 is used, since the measurement point is placed in the air which is not in contact with the molded product, the heat storage of the plastic molding mold 1 is performed. Since the action can be ignored, the temperature of the temperature adjusting medium F can be controlled in response to the temperature change of the molding surface 1S, and the temperature of the molding surface 1S can be quickly and accurately controlled to the target temperature.

Since the non-contact type temperature sensor S3 is in the air at a certain distance from the molding surface 1S, it detects a temperature lower than the actual surface temperature of the molding surface due to thermal diffusion, and measures the value. Since the temperature signal is transmitted to the temperature / temperature controller 3, it is possible to swiftly cope with the supercooling of the surface temperature of the molding surface 1S, which is the largest cause of defective plastic molded products.

(Embodiment 2) FIG. 2 is a schematic diagram showing another embodiment of the mold temperature controller according to the present invention. This mold temperature controller Kc is the same as the mold temperature controller X,
A temperature sensor position control means 7 for moving the non-contact type temperature sensor S3 is provided.

The temperature sensor position control means 7 is mechanically and electrically connected to the non-contact type temperature sensor S3 and the temperature controller 3, and is controlled by the temperature controller 3 for discriminating the operation of the die 1. The non-contact temperature sensor S3 can be moved to a desired position. FIG. 3 is a schematic diagram showing the operation of the mold temperature controller X1 shown in FIG. 2, focusing on the non-contact temperature sensor S3.

In FIG. 3, FIG. 3A shows a state where the plastic molding die 1 is clamped, and FIG. 3B shows a state where the plastic molded product 8 is taken out. . In this mold temperature controller X1, as shown in FIG. 3 (a), the temperature sensor position control means 7 includes a non-contact temperature sensor S3 and a movable mold cavity 1b of the plastic molding mold 1. While the fixed mold cavity 1a is clamped, both mold cavities 1a, 1a
b to the position close to the joint surface Sc, and as shown in FIG.
As shown in (b), while the movable mold cavity 1b of the plastic molding mold 1 is separated from the fixed mold cavity 1a, and the plastic molded product 8 is taken out, temperature sensor position control means 7, the non-contact type temperature sensor S3 is moved to a position close to the molding surface 1aS of the fixed mold cavity 1a.

Incidentally, in FIG. 3B, the non-contact type temperature sensor S3 is used as the molding surface 1aS of the fixed mold cavity 1a.
Although an example in which the temperature sensor position control means 7 moves the non-contact type temperature sensor S3 during the period when the plastic molded product 8 is taken out, the movable mold cavity 1b is shown. It may be moved to a position close to the molding surface 1bS.

In the second embodiment, the temperature sensor position control means 7
Includes a non-contact type temperature sensor S3, a movable cavity 1b and a fixed cavity 1a of the plastic molding die 1.
However, while the mold is being clamped, both cavities 1
While the movable cavities 1b are separated from the fixed cavities 1a while the plastic cavities are taken out while the movable cavities 1b are placed close to the joint surfaces of a and 1b, the movable cavities 1b or the fixed cavities 1a are molded. Since they are brought close to the surfaces 1bS, 1aS, compared to the first embodiment,
The surface temperature of the molding surface of the plastic molding die 1 can be controlled to the target temperature with higher accuracy.

Needless to say, the present invention has various modifications. A non-contact type temperature sensor 3 is provided in the vicinity of the surface of the plastic molding die 1, and a measurement point is set so as to measure the temperature on the surface of the plastic molded article being molded in the plastic molding die 1 and being taken out. Good. This is because the temperature of the surface of the plastic molded product is immediately after being separated from the molding surface 1S of the plastic molding die 1, the molding surface 1S of the plastic molding die 1.
The surface temperature is almost the same.

[0036]

As described above in detail, the mold temperature controller of the present invention uses a non-contact type temperature sensor, and it is necessary to embed the temperature sensor in a plastic molding mold. Since there is no, there is a non-contact type temperature sensor (infrared sensor)
Is easy to install and the plastic mold can be easily changed.

Further, since the non-contact type temperature sensor (infrared sensor) is placed in the space on the surface of the molding surface of the plastic molding die, the heat storage action of the plastic molding die can be neglected. The temperature of the temperature control solvent can be controlled in a quick response to changes in the surface temperature of the surface. Therefore, it is possible to control the surface temperature of the plastic molding surface to a desired temperature, and always to a more optimal temperature, which is the cause of defective products of the plastic molding product. The problem goes away.

Therefore, since the surface temperature of the plastic molding surface can be controlled to a desired temperature and always to a more optimal temperature, it is possible to switch to direct control or indirect control as in the conventional case, or based on experience. , Calculate the estimated value,
There is no need to perform complicated control such as controlling the surface temperature of the plastic molding surface to the target temperature. Furthermore , the surface temperature of the plastic molding surface can be measured by moving the contact-type temperature sensor to the closest position according to the control operation of the plastic molding die. The temperature of the temperature control medium can be controlled to the target temperature more easily, faster and more accurately.

[Brief description of drawings]

FIG. 1 is a configuration diagram schematically showing an embodiment of a mold temperature controller according to the present invention.

FIG. 2 is a configuration diagram schematically showing another embodiment of the mold temperature controller according to the present invention.

FIG. 3 is a schematic diagram showing the operation of the mold temperature controller shown in FIG. 2, focusing on a non-contact type temperature sensor.

FIG. 4 is a schematic diagram showing a conventional mold temperature controller.

FIG. 5 is a conceptual diagram of a control time history for explaining the operation of the mold temperature controller.

[Explanation of symbols]

X, X1 Mold temperature controller according to the present invention Y plastic molding machine S3 Non-contact temperature sensor P pump F Temperature control medium 1 plastic mold 1a Fixed mold cavity 1b Movable mold cavity 1aS, 1bS Molded surface Sc joint surface 2 Medium temperature control device 3 temperature controller 7 Temperature sensor position control means

─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-63-56410 (JP, A) JP-A-63-185611 (JP, A) JP-A-62-13309 (JP, A) JP-A-57- 35737 (JP, A) Actual Kaihei 2-8916 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B29C 33/00-33/76 B29C 45/00-45/84

Claims (3)

(57) [Claims] 1. A non-contact type temperature sensor is arranged in a plastic molding die, and the measured value by this temperature sensor is input to a temperature controller as a temperature measurement signal to control the temperature control medium to a predetermined target temperature. In the mold temperature controller configured as described above, during the period in which the movable cavity and the fixed cavity of the plastic molding die are clamped, the non-contact mold is placed at a position close to the joint surface of both cavities. While the temperature sensor is installed, the movable cavity is separated from the fixed cavity and the non-contact type temperature sensor is used to mold the movable cavity or the fixed cavity while the molded product is taken out. A mold temperature controller comprising a temperature sensor position control means for moving the temperature sensor to a position close to the surface. 2. A non-contact type temperature sensor is arranged in a plastic molding die, and the measured value by this temperature sensor is input to a temperature controller as a temperature measurement signal to control the temperature control medium to a predetermined target temperature. In the mold temperature controller configured as described above, the non-contact type temperature sensor has a position close to the joint surface of the movable cavity and the fixed cavity of the plastic molding die, and the movable cavity or the fixed cavity. It is installed in a position close to the molding surface, and is close to the joint surface of both the movable and fixed cavities during the period when the movable cavity and the fixed cavity of the plastic molding die are clamped. The non-contact temperature sensor installed at the position is used, and the movable cavity is separated from the fixed cavity. While the product is being taken out, the temperature is measured using the non-contact type temperature sensor installed in the position close to the molding surface of the movable cavity or the fixed cavity, and the temperature control medium is stored. A mold temperature controller configured to control to a predetermined target temperature. 3. The mold temperature controller according to claim 1, wherein the non-contact type temperature sensor is an infrared sensor.