JP3505680B2 - Pressure-holding control method and pressure-holding control device for injection molding machine - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a holding pressure control method and a holding pressure control device for an injection molding machine.

[0002]

2. Description of the Related Art In a pressure-holding process in an injection molding machine, pressure is continuously applied to a resin in a mold for a certain period of time, and during that time, the volume of the resin shrinks as the molded product is cooled, so that it is necessary in the mold. This is the step of replenishing the resin. Further, there is a holding pressure setting suitable for the molded product depending on the shape of the molded product and the characteristics of the resin. Therefore, the pressure-holding process easily affects the degree of completion of non-defective products.

In the current injection molding machine, as a measure against a defective product, the rate of change in the pressurizing / pressurizing force response that defines the rising / falling characteristics of the holding pressure can be selectively set. Also, the setting of the pressure holding process is generally 2
The setting is performed in stages, but the setting of 3 to 4 stages is effective for a mold or an ultra-thick molded product in which burrs and the like are likely to occur. Then, when molding is performed in such a multi-stage pressure-holding process, a defect is prevented by using a setting mode that is common to each stage in response to the pressurizing / pressurizing force.

FIG. 4 shows an example of the construction of a conventional pressure-holding control device in which the pressure-holding process is divided into four stages. In FIG.
The pressure holding control device includes a mode setting unit 41, a pattern storage unit 42, and a pressure setting unit 43. Mode setting unit 4
1 is a means for selecting and setting a mode common to each of the four stages, and the mode here is a "low response" for the pressurizing / depressurizing force response.
(Soft), "Medium response" (Standard), "High response"
It is designed to select from three types (sharp).
The pattern storage unit 42 stores pressure change patterns corresponding to the above “low response”, “medium response”, and “high response”, and the pressure change pattern corresponding to the mode selected by the mode setting unit 41. Is output. This pressure change pattern has different rising or falling characteristics depending on whether it is “low response”, “medium response”, or “high response”. That is, if "low response", the rising or falling is gentle, and if "high response", the rising or falling is steep.

The pressure setting unit 43 is a one-stage pressure setting unit 43-
1st and 2nd stage pressure setting section 43-2, 3rd stage pressure setting section 43-
The pressure setting unit 43-4 has three and four stages, and the operator sets the holding pressure for each stage. For example, regarding the first-stage pressure setting unit 43-1, the first-stage holding pressure set by the operator is multiplied by the pressure change pattern from the pattern storage unit 42 to output the first-stage pressure command.

The pressure holding control device is not separately provided in the injection molding machine only for pressure holding control, but is provided in the injection molding machine such as a control device, a setting condition input device, and a storage device. It can be said that FIG. 4 is, so to speak, a functional configuration block diagram thereof.

In any case, as is clear from the above description, the rate of change of the pressurizing / pressurizing force response that is selectively set by the mode setting unit 41 is common to each of the four stages.

[0008]

However, each stage of the pressure-holding process has individual roles such as "burr prevention", "air bleeding", "shrinkage prevention", "dimensional accuracy", and "stress relief". . On the other hand, in the above-mentioned apparatus, it cannot be said that the rate of change in the pressurization / depressurization force response that is suitable for each stage is selected, and the degree of freedom in molding cannot be exhibited.

Therefore, an object of the present invention is to enable detailed pressure holding setting in each of a plurality of stages which are divided and set in the pressure holding process, so that there is more freedom for increasing the degree of completion of a molded product. It is to realize high molding.

[0010]

According to the present invention, in a holding pressure control method for an injection molding machine, the holding pressure process is divided into a plurality of stages so that the holding pressure of each stage can be set individually. At the same time, it is characterized in that the rate of change of the pressurizing / pressurizing force response at each stage can be set individually.

Further, according to the present invention, in the pressure maintaining control device of the injection molding machine, wherein the pressure maintaining process is divided into a plurality of stages, and each stage can be controlled by the individual pressure maintaining pressure, Mode setting means for selectively setting the rate of change of response for each step; pattern output means provided for each step and outputting a pressure change pattern according to the rate of change of the pressurizing / pressurizing force response selected and set by the mode setting means. A pressure control device for an injection molding machine, comprising means for outputting a pressure command value for each stage based on the pressure change pattern output for each stage and the holding pressure set individually. Will be provided.

In both the pressure holding control method and the pressure holding control device described above, the mode setting means sets the type of the rate of change of the pressurizing / pressurizing force response to "low response", "medium response", and "high response". It can be arbitrarily selected from the three types.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to FIGS. FIG. 1 shows the configuration of a control device when the pressure holding process is divided into four stages. Of course, this pressure holding control device is not separately provided in the injection molding machine exclusively for the pressure holding control, but is realized by the control device, the setting condition input device, the storage device and the like provided in the injection molding machine. It can be said that FIG. 1 is, so to speak, a functional configuration block diagram thereof.

In FIG. 1, a mode setting section 11 for selecting and setting the rate of change of the pressurizing / pressurizing force response in each of the four stages.
And a pattern storage unit 12 that is provided for each stage and that outputs a pressure change pattern according to the rate of change of the pressurizing / pressurizing force response that is selectively set by the mode setting unit 11, and the pressure change pattern that is output for each stage and the operator. A pressure setting unit 13 that outputs a pressure command value for each stage based on the holding pressure for each stage that is individually set is provided.

The mode setting unit 11 is a one-stage mode setting unit 1.
The pattern storage unit 12 includes a 1-1, 2-step mode setting section 11-2, a 3-step mode setting section 11-3, and a 4-step mode setting section 11-4. A one-step pattern storage section 12-1, a two-step pattern storage section 12-2, a three-step pattern storage section 12-3, and a four-step pattern storage section 12 connected so as to correspond to each of the mode setting sections 11-4. -4. Similarly, the pressure setting unit 13
Is a first-stage pressure setting unit 13-1, a second-stage pressure setting unit 13-2, and a third-stage pressure connected so as to correspond to each of the first-stage pattern storage units 12-1 to 12-4. The setting unit 13-3 and the four-stage pressure setting unit 13-4 are included.

In the first-stage mode setting unit 11-1 to the fourth-stage mode setting unit 11-4, the rate of change of the pressure-pressurizing force response is set to "low response" (software), "medium response" (standard), and "high response", respectively. "(Sharp)" can be selected and set. One-step pattern storage units 12-1 to 12-4
The stage pattern storage unit 12-4 stores pressure change patterns corresponding to "low response", "medium response", and "high response", respectively, that is, the mode selected by the corresponding mode setting unit, that is, The pressure change pattern corresponding to the change rate of the pressurization / depressurization force response is output.

Each of the first-stage pressure setting units 13-1 to 13-4 has a pressure change pattern output from the corresponding pattern storage unit and a holding pressure set value for each stage set by the operator. The pressure command value of each stage is output by.

As is clear from the above description, in the present embodiment, in the molding using the four-stage pressure holding setting divided and set in the pressure holding process, the rate of change in the pressurizing / pressurizing force response suitable for each stage is required. In this case, the rate of change of the pressurizing / pressurizing force response can be set individually for each stage as the pressure-holding operation mode, which is significantly different from the conventional configuration.

FIG. 2 shows an example of holding pressure setting of four stages set in the pressure setting unit 13. In FIG. 2, the first-stage pressure setting unit 1
In 3-1 a low pressure holding pressure that emphasizes "air bleeding" for "burr prevention" is set, and in the two-stage pressure setting unit 13-2, a medium pressure holding pressure that emphasizes "shrinkage prevention" is set. It is set. Also, in the three-stage pressure setting unit 13-3, "dimensional accuracy"
The high pressure holding pressure is set with emphasis on, and the low pressure holding pressure with emphasis on "stress relief" is set in the four-stage pressure setting unit 13-4.

FIG. 3 shows an example of holding pressure detection at each stage. Here, the first stage mode setting unit 11-1 has a "medium response" and the second stage mode setting unit 11-2 has a "low response". "High response" in the three-stage mode setting unit 11-3,
The case where "low response" is selectively set in the 4-step mode setting unit 11-4 is shown. In the second and fourth steps, the rising or falling is the slowest, and in the third step, the rising is the steepest.
It can be seen that in the second stage, it exhibits intermediate characteristics between them. Of course, how many stages the pressure holding process is divided into is arbitrary.

In other words, while observing the state of the molded product, more detailed holding pressure conditions suitable for the resin and the molded product can be reviewed and set. Therefore, molding with a high degree of freedom becomes possible, which helps improve the quality of molded products such as the prevention of defective products.

[0022]

According to the present invention, since it is possible to set the detailed pressure holding in each of a plurality of stages divided and set in the pressure holding process, it is possible to increase the degree of freedom for increasing the degree of completion of the molded product. High molding can be realized, which can contribute to the improvement of the quality of molded products.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a holding pressure control device according to the present invention.

FIG. 2 is a diagram showing a four-stage holding pressure setting example set in a pressure setting unit shown in FIG.

FIG. 3 is a diagram showing an example of holding pressure detection at each stage in the case of four stages in the present invention.

FIG. 4 is a block diagram showing a configuration of a conventional pressure holding control device.

[Explanation of symbols]

11, 41 Mode setting section 12, 42 Pattern storage 13, 43 Pressure setting section

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) B29C 45/00-45/84 B22D 17/32

Claims (4)

(57) [Claims] 1. A holding pressure control method for an injection molding machine, wherein the holding pressure process is divided into a plurality of stages so that the holding pressure of each stage can be set individually, and a change in the pressurizing / depressurizing force response at each stage. A holding pressure control method for an injection molding machine, characterized in that the rate can be set individually. 2. The holding pressure control method according to claim 1, wherein
The method of holding pressure control of an injection molding machine, wherein the type of the rate of change of the pressurizing / pressurizing force response can be arbitrarily selected from three types of "low response", "medium response", and "high response". . 3. A pressure-holding control device for an injection molding machine, wherein the pressure-holding process is divided into a plurality of stages so that each stage can be controlled by an individual holding pressure. Mode setting means for selectively setting each stage, pattern output means provided for each stage and outputting a pressure change pattern according to the rate of change of the pressurizing / depressurizing force response selectively set by the mode setting means, and for each stage A holding pressure control device for an injection molding machine, comprising: means for outputting a pressure command value at each stage based on the output pressure change pattern and the holding pressure set individually. 4. The holding pressure control device according to claim 3,
The mode setting means is capable of arbitrarily selecting the type of rate of change of the pressurizing / pressurizing force response from three types of "low response", "medium response", and "high response". Pressure control device for machine.