WO2023184629A1

WO2023184629A1 - Constant temperature control system and method for garbage can injection mold

Info

Publication number: WO2023184629A1
Application number: PCT/CN2022/088975
Authority: WO
Inventors: 梁正华; 李茂明
Original assignee: 浙江凯华模具有限公司
Priority date: 2022-03-31
Filing date: 2022-04-25
Publication date: 2023-10-05
Also published as: CN114872291A

Abstract

A constant temperature control system and method for a garbage can injection mold. The mold comprises a cavity mold (1) and a core mold (2); the system comprises a controller and a water temperature controller; the cavity mold (1) and the core mold (2) are evenly divided into a plurality of temperature adjusting layers (6); an outer temperature adjusting flow channel (3) arranged in the cavity mold (1) and an inner temperature adjusting flow channel (4) arranged in the core mold (2) are comprised in each temperature adjusting layer (6); the inner temperature adjusting flow channels (4) and the outer temperature adjusting flow channels are connected to the water temperature controller by means of water inlet pipelines; and a plurality of temperature sensors (5) are arranged on each temperature adjusting layer (6). In a temperature adjusting process, a first-stage temperature adjusting and step-by-step temperature adjusting combined mode is used, and step-by-step temperature adjusting is used after a temperature is close to a constant temperature, such that the temperature changes in a stepped mode and is gradually close to the constant temperature, thereby enabling the temperature adjusting to be more stable and accurate, and preventing an injection molded piece from cracking or a material from changing due to sudden change of the temperature.

Description

A constant temperature control system and method for a trash can injection mold

Technical field

The invention relates to the technical field of mold injection molding, and in particular to a thermostatic control system and method for a garbage bin injection mold.

Background technique

Plastic trash cans are widely used in people's lives. These plastic trash cans are generally made by injection molding using molds. Mold temperature control is very important during the injection molding process. It is necessary to keep the mold and internal temperature in a relatively stable range. However, many injection molding machines currently do not do a good job in temperature control. The temperature adjustment is not precise enough and is prone to sudden temperature changes. This causes the workpiece to crack due to sudden temperature changes and the material properties to change, affecting the quality of the workpiece.

Contents of the invention

The present invention mainly solves the problem in the prior art that the temperature control of the injection molding machine is unstable, causing the workpiece to crack or the material properties to change, affecting the quality of the workpiece. It provides a constant temperature control system and method for a trash can injection mold.

The above technical problems of the present invention are mainly solved through the following technical solutions: a thermostatic control system for a trash can injection mold. The mold includes a combined cavity mold and a core mold, including a controller and a water temperature controller. The cavity mold and the core mold are evenly divided into several temperature-regulating layers along the mold opening direction. Each temperature-regulating layer includes an external temperature-regulating flow channel arranged around the cavity in the cavity mold, and an internal temperature-adjusting flow channel arranged around the core mold. The external temperature-adjusting runner is connected to the water temperature controller through the first water inlet pipe, and the internal temperature-adjusting runner is connected to the water temperature controller through the second water inlet pipe. Each temperature-adjusting layer is embedded in the cavity mold. There are several temperature sensors, and the water temperature controller and the temperature sensor are respectively connected to the controller; the temperature-regulating layer separation can be physically separated or just divided. The physical separation can be separated by setting partitions between each temperature-regulating layer in the cavity. Reduce the influence of the temperature control layers on each other. The temperature-regulating layers are parallel to the horizontal plane. Each temperature-regulating layer includes an external temperature-regulating flow channel located in the cavity mold and an internal temperature-regulating flow channel located in the core mold, as well as a temperature sensor embedded in the cavity mold. The temperature sensor Multiple temperature sensors can be set up around the cavity mold, and the temperature sensor is close to the cavity surface of the cavity model.

Temperature sensor: detects the actual temperature of the temperature-regulating layer in real time and sends the detection information to the controller;

Controller: Based on the temperature difference between the actual temperature value and the constant temperature, the first-stage temperature adjustment judgment is made for each temperature-regulating layer, and the temperature is adjusted to the upper and lower limit temperatures; then the temperature of each temperature-regulating layer is adjusted step by step until the actual temperature reaches the constant temperature. Temperature adjustment is stopped when the actual temperature exceeds the constant temperature range. After the actual temperature exceeds the constant temperature range, the corresponding temperature adjustment layer is adjusted step by step to stabilize the temperature within the constant temperature range.

The temperature adjustment process of the present invention adopts a combination of first-stage temperature adjustment and step-by-step temperature adjustment. The first-stage temperature adjustment adopts rapid temperature adjustment, which is a rough adjustment. In order to make the temperature quickly approach the constant temperature, the method is adopted after the temperature is close to the constant temperature. Step-by-step temperature adjustment, for precise adjustment, the temperature changes in a step-like manner and gradually approaches the constant temperature, making the temperature adjustment more stable and preventing sudden changes in temperature from causing problems in injection molding.

A method for constant temperature control of a trash can injection mold, using the system in claim 1, including the following steps:

Step 1. Set the temperature monitoring parameters, including constant temperature, constant temperature range, upper limit temperature and lower limit temperature, and evenly divide the mold into several temperature-regulating layers including temperature-regulating flow channels along the mold opening direction;

Step 2. Detect the actual temperature in the mold in real time, make first-stage temperature adjustment judgments for each temperature-regulating layer based on the temperature difference between the actual temperature and the constant temperature, and adjust the temperature to the upper and lower limit temperatures;

Step 3. Adjust the temperature of each temperature-regulating layer step by step, and stop adjusting when the actual temperature reaches the constant temperature;

Step 4. Detect the actual temperature of each temperature-regulating layer in real time, adjust the temperature of the temperature-regulating layer beyond the constant temperature range step by step, and stabilize the temperature within the constant temperature range.

As a preferred solution, the specific process of step 2 includes:

(2-1) Obtain the actual temperature of each temperature-regulating layer, calculate the absolute value of the difference between the actual temperature and the constant temperature, and obtain the minimum value as the comparison value △T;

(2-2) Determine whether △T is greater than the threshold Ta. If it is judged as heating or cooling, if not, proceed to step (2-4); the threshold Ta is the difference between the upper limit temperature and the constant temperature.

(2-3) Determine whether △T is greater than zero. If cooling is performed, control the external temperature-adjusting flow channel and the internal temperature-adjusting flow channel to inject low-temperature water at the same time until the temperature of the temperature-adjusting layer reaches the upper limit temperature, and the internal temperature-adjusting flow channel stops injecting low-temperature water. temperature water, enter step 3; if heating is not performed, control the external temperature-adjusting flow channel and the internal temperature-adjusting flow channel to inject high-temperature water at the same time until the temperature of the temperature-adjusting layer reaches the lower limit temperature, and the internal temperature-adjusting flow channel stops injecting high-temperature water, enter Step 3: Subtract the constant temperature from the actual temperature and take the absolute value to obtain the absolute value of the difference, then select the maximum value as the comparison value △T, and judge the actual temperature based on whether △T is greater than zero, that is, a positive number or a negative number. The temperature of the injected low-temperature water and high-temperature water can be set according to needs to determine the temperature adjustment speed. The temperature of low-temperature water is at least lower than the constant temperature, and the temperature of high-temperature water is at least higher than the constant temperature. At the same time, water is injected into the external temperature-adjusting runner and the internal temperature-adjusting runner, and the temperature adjustment speed is increased. In the first stage, the mold temperature can be quickly adjusted to the upper limit temperature or the lower limit temperature to prepare for subsequent step-by-step temperature adjustment. After the temperature of the temperature-regulating layer reaches the upper limit temperature or the lower limit temperature, it enters step-by-step temperature regulation. At this time, the internal temperature-regulating flow channel stops injecting water, and only the external temperature-regulating flow channel injects water for temperature regulation, so as to achieve a more accurate and stable Temperature adjustment.

(2-4) Determine whether the actual temperature is within the constant temperature range. If not, go to step 3. If not, go to step 4.

As a preferred solution, step 3 specifically includes:

(3-1) According to the absolute value of the difference between the actual temperature and the constant temperature, it is divided into multiple temperature intervals;

(3-2) Control the injection of water into the external temperature-adjusting flow channel, adjust the temperature of each temperature-adjusting layer to the upper limit or lower limit of the current temperature range, and stop injecting water into the external temperature-adjusting flow channel; stopping the injection of water here means pausing to continue external temperature adjustment. Low-temperature or high-temperature water is injected into the flow channel, while the external temperature-adjusting flow channel is still filled with water but does not flow. The residual temperature of the water in the external temperature-adjusting flow channel is used to keep the temperature stable within the temperature range.

(3-3) Determine whether the temperatures of all temperature-regulating layers have reached the upper limit or lower limit of the temperature range. If so, enter the next adjacent temperature range for temperature adjustment. If not, continue with the current judgment;

(3-4) Repeat steps (3-2) and (3-3) until the temperature of the temperature-regulating layer is adjusted to a constant temperature and the external temperature-regulating flow channel stops injecting water. Here, only when the temperatures of all temperature-regulating layers reach the upper limit or lower limit of the temperature range, the temperature adjustment of the next adjacent temperature range starts. During this process, the temperature may repeat after reaching the upper or lower limit of the temperature range. However, due to the small temperature difference between each temperature-regulating layer, the time to reach the upper and lower limits of the temperature range is shorter, and the temperature loss is relatively small. Therefore, It only needs to be judged whether all temperature regulation layers have reached the upper limit or lower limit of the temperature range. When performing heating adjustment, judgment is made based on the upper limit value of the temperature interval. After the temperature of all temperature adjustment layers reaches the upper limit value of the temperature interval, temperature adjustment in a higher temperature interval is performed. When performing cooling adjustment, judgment is made based on the lower limit value of the temperature range.

As a preferred solution, step 4 specifically includes:

(4-1) Real-time detection of the actual temperature of each temperature-regulating layer;

(4-2) Determine whether the actual temperature of the temperature-regulating layer exceeds the constant temperature range. If not, no temperature adjustment is performed. If the temperature of the temperature-regulating layer is adjusted step by step, until the temperature is adjusted to the constant temperature range. After the temperature is adjusted to a constant temperature through step-by-step temperature adjustment, the water injection into the external temperature-adjusting flow channel is stopped. After that, the temperature of the temperature-adjusting zone changes for a period of time until it exceeds the constant temperature range. Then the temperature-adjusting layer beyond the constant temperature range is Temperature adjustment also adopts step-by-step temperature adjustment to adjust the temperature to a constant temperature range. When setting the temperature range, make sure that the upper and lower limits of the temperature range do not coincide with the upper and lower limits of the constant temperature range. The upper and lower limits of the constant temperature range are located in the corresponding temperature range. During the temperature adjustment process, the constant temperature is included. Temperature adjustment of the temperature range of the upper limit value or lower limit value of the temperature range, and the temperature is adjusted to a constant temperature range.

As a preferred solution, the upper limit temperature is greater than the upper limit of the constant temperature range, and the lower limit temperature is less than the lower limit of the constant temperature range.

As a preferred solution, the closer the subdivided temperature interval is to the constant temperature, the smaller the temperature interval range will be. This allows the actual temperature to gradually stabilize at a constant temperature and achieve precise temperature control.

Therefore, the advantage of the present invention is that it adopts a combination of first-stage temperature adjustment and step-by-step temperature adjustment. The first-stage temperature adjustment adopts rapid temperature adjustment, which is a rough adjustment. In order to make the temperature quickly approach the constant temperature, the temperature is adjusted when the temperature is close to the constant temperature. Later, step-by-step temperature adjustment was adopted. For precise adjustment, the temperature changes in a step-like manner and gradually approaches the constant temperature. The temperature adjustment is more stable and prevents the problem of cracking or material change of the injection molded parts caused by sudden temperature changes.

Description of drawings

Figure 1 is a structural schematic cross-sectional view of the mold of the present invention;

Figure 2 is a schematic flow chart of the method of the present invention.

1-Cavity mold 2-Core mold 3-External temperature regulating runner 4-Internal temperature regulating runner 5-Temperature sensor 6-Temperature regulating layer.

Detailed ways

The technical solution of the present invention will be further described in detail below through examples and in conjunction with the accompanying drawings.

Example 1:

This embodiment is a thermostatic control system for a trash can injection mold. As shown in Figure 1, the mold includes a combined cavity mold 1 and a core mold 2. The system also includes a controller and a water temperature controller. The cavity mold and core mold are evenly divided into several temperature-regulating layers along the mold opening direction, as shown in the figure between the two dotted lines. Only part of the temperature-regulating areas are marked in the figure. The temperature-regulating layer can be physically separated or just divided. For physical separation, a partition is set between each temperature-regulating layer in the mold. The partition is only located on the side of the cavity mold or core mold near the mold cavity and is located on the side of the temperature-regulating layer. This physical separation is used to reduce the temperature influence between the temperature-regulating layers between the warm flow channels.

Each temperature-regulating layer includes an external temperature-regulating flow channel 3 surrounding the cavity in the cavity mold, and an internal temperature-regulating flow channel 5 surrounding the core mold. The water temperature controller includes a water storage device to output water at a set temperature. , there are two water temperature controllers, namely a first water temperature controller and a second water temperature controller. The external temperature regulating flow channel is connected to the first water temperature controller through the first water inlet pipe, and the internal temperature regulating flow channel passes through the second water inlet pipe. The pipeline is connected to the second water temperature controller, and a number of temperature sensors 5 are embedded in each temperature-regulating layer on the cavity mold. The water temperature controller and the temperature sensor are respectively connected to the controller; the internal temperature-regulating flow channel and the external temperature-regulating flow channel The channels are all annular flow channels, preferably arranged in the same plane and located in the middle part of the same temperature-regulating layer. The temperature sensor is arranged on the cavity mold near the mold cavity and located in the middle of the temperature-regulating layer, so that the temperature-regulating layer can be measured more accurately. Temperature is detected.

Example 2:

This embodiment provides a constant temperature control method for a trash can injection mold, as shown in Figure 2, including the following steps:

Step 2. Detect the actual temperature in the mold in real time, make a first-stage temperature adjustment judgment on each temperature-regulating layer based on the temperature difference between the actual temperature and the constant temperature, and adjust the temperature to the upper and lower limit temperatures; specifically including:

(2-2) Determine whether △T is greater than the threshold Ta. If it is judged to be heating or cooling, if not, proceed to step (2-4);

(2-3) Determine whether △T is greater than zero. If cooling is performed, control the external temperature-adjusting flow channel and the internal temperature-adjusting flow channel to inject low-temperature water at the same time until the temperature of the temperature-adjusting layer reaches the upper limit temperature, and the internal temperature-adjusting flow channel stops injecting low-temperature water. temperature water, enter step 3; if heating is not performed, control the external temperature-adjusting flow channel and the internal temperature-adjusting flow channel to inject high-temperature water at the same time until the temperature of the temperature-adjusting layer reaches the lower limit temperature, and the internal temperature-adjusting flow channel stops injecting high-temperature water, enter Step 3; The upper limit temperature is greater than the upper limit of the constant temperature range, and the lower limit temperature is less than the lower limit of the constant temperature range. The temperature of the injected low-temperature water and high-temperature water can be set according to needs to determine the temperature adjustment speed. The temperature of low-temperature water is at least lower than the constant temperature, and the temperature of high-temperature water is at least higher than the constant temperature.

Step 3. Adjust the temperature of each temperature-regulating layer step by step, and stop adjusting when the actual temperature reaches the constant temperature; specifically including:

(3-1) According to the absolute value of the difference between the actual temperature and the constant temperature, it is divided into multiple temperature intervals; the temperature interval is subdivided in such a way that the closer the temperature interval is to the constant temperature, the smaller the temperature interval range will be.

(3-2) Control the injection of water into the external temperature-adjusting flow channel, adjust the temperature of each temperature-adjusting layer to the upper limit or lower limit of the current temperature range, and stop injecting water into the external temperature-adjusting flow channel; stopping the injection of water means pausing and continuing the external temperature-adjusting flow. Low-temperature or high-temperature water is injected into the channel, while the external temperature-adjusting flow channel is still filled with water but does not flow. The residual temperature of the water in the external temperature-adjusting flow channel is used to keep the temperature stable within the temperature range.

(3-3) Determine whether the temperatures of all temperature-regulating layers have reached the upper limit or lower limit of the temperature range. If so, enter the next adjacent temperature range for temperature adjustment. If not, continue with the current judgment; during this process, The temperature may repeat after reaching the upper or lower limit of the temperature range. However, due to the small temperature difference between each temperature-regulating layer, the time to reach the upper and lower limits of the temperature range is short, and the temperature loss is relatively small. It only needs to judge all the temperature-regulating layers. Whether all layers have reached the upper limit or lower limit of the temperature range.

(3-4) Repeat steps (3-2) and (3-3) until the temperature of the temperature-regulating layer is adjusted to a constant temperature and the external temperature-regulating flow channel stops injecting water.

Step 4. Detect the actual temperature of each temperature-regulating layer in real time, adjust the temperature of the temperature-regulating layer beyond the constant temperature range step by step, and stabilize the temperature within the constant temperature range. Specifically include:

(4-2) Determine whether the actual temperature of the temperature-regulating layer exceeds the constant temperature range. If not, no temperature adjustment is performed. If the temperature of the temperature-regulating layer is adjusted step by step, until the temperature is adjusted to the constant temperature range. Step-by-step temperature adjustment is the same as in step 3. In this step, you only need to adjust the temperature to a constant temperature range. When setting the temperature interval, make sure that the upper and lower limits of the temperature interval do not coincide with the upper and lower limits of the constant temperature interval. Then the upper limit and lower limit of the constant temperature interval are located in the corresponding temperature interval, and the constant temperature is included in the temperature adjustment process. Temperature adjustment in the temperature range of the upper limit or lower limit of the range. When the temperature is adjusted to the upper limit or lower limit of the corresponding temperature range, it is within the constant temperature range. Subsequently, the temperature of the temperature-regulating layer will be continuously detected in real time. As long as the temperature exceeds the constant temperature range, the temperature will be adjusted to stabilize the temperature within the constant temperature range.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention belongs can make various modifications or additions to the described specific embodiments or substitute them in similar ways, but this will not deviate from the spirit of the present invention or exceed the definition of the appended claims. range.

Although this article uses terms such as cavity mold, core mold, external temperature-adjusting runner, internal temperature-adjusting runner, temperature sensor, temperature-adjusting layer, etc., it does not rule out the possibility of using other terms. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations is contrary to the spirit of the present invention.

Claims

A constant temperature control system for a trash can injection mold. The mold includes a combined cavity mold and a core mold. It is characterized by: including a controller and a water temperature controller, which are evenly spaced along the mold opening direction on the cavity mold and the core mold. into several temperature-adjusting layers. Each temperature-adjusting layer includes an external temperature-adjusting runner arranged around the cavity in the cavity mold, an internal temperature-adjusting runner arranged around the core mold, and the external temperature-adjusting runner passes through the first water inlet. The pipeline is connected to the water temperature controller, and the internal temperature-regulating flow channel is connected to the water temperature controller through the second water inlet pipe. Each temperature-regulating layer is embedded with a number of temperature sensors on the cavity mold. The water temperature controller and the temperature sensor are respectively connected to the water temperature controller. Controller connection;

Temperature sensor: detects the actual temperature of the temperature-regulating layer in real time and sends the detection information to the controller;

Controller: Based on the temperature difference between the actual temperature value and the constant temperature, the first-stage temperature adjustment judgment is made for each temperature-regulating layer, and the temperature is adjusted to the upper and lower limit temperatures; then the temperature of each temperature-regulating layer is adjusted step by step until the actual temperature reaches the constant temperature. Temperature adjustment is stopped when the actual temperature exceeds the constant temperature range. After the actual temperature exceeds the constant temperature range, the corresponding temperature adjustment layer is adjusted step by step to stabilize the temperature within the constant temperature range.
A method for constant temperature control of a trash can injection mold, using the system in claim 1, characterized by comprising the following steps:

Step 1. Set the temperature monitoring parameters, including constant temperature, constant temperature range, upper limit temperature and lower limit temperature, and evenly divide the mold into several temperature-regulating layers including temperature-regulating flow channels along the mold opening direction;

Step 2. Detect the actual temperature in the mold in real time, make first-stage temperature adjustment judgments for each temperature-regulating layer based on the temperature difference between the actual temperature and the constant temperature, and adjust the temperature to the upper and lower limit temperatures;

Step 3. Adjust the temperature of each temperature-regulating layer step by step, and stop adjusting when the actual temperature reaches the constant temperature;

Step 4. Detect the actual temperature of each temperature-regulating layer in real time, adjust the temperature of the temperature-regulating layer beyond the constant temperature range step by step, and stabilize the temperature within the constant temperature range.
A constant temperature control method for a trash can injection mold according to claim 2, characterized in that the specific process of step 2 includes:

(2-1) Obtain the actual temperature of each temperature-regulating layer, calculate the absolute value of the difference between the actual temperature and the constant temperature, and obtain the minimum value as the comparison value △T;

(2-2) Determine whether △T is greater than the threshold Ta. If it is judged to be heating or cooling, if not, proceed to step (2-4);

(2-3) Determine whether △T is greater than zero. If cooling is performed, control the external temperature-adjusting flow channel and the internal temperature-adjusting flow channel to inject low-temperature water at the same time until the temperature of the temperature-adjusting layer reaches the upper limit temperature, and the internal temperature-adjusting flow channel stops injecting low-temperature water. temperature water, enter step 3; if heating is not performed, control the external temperature-adjusting flow channel and the internal temperature-adjusting flow channel to inject high-temperature water at the same time until the temperature of the temperature-adjusting layer reaches the lower limit temperature, and the internal temperature-adjusting flow channel stops injecting high-temperature water, enter Step 3;

(2-4) Determine whether the actual temperature is within the constant temperature range. If not, go to step 3. If not, go to step 4.
A method for constant temperature control of a trash can injection mold according to claim 3, characterized in that step 3 specifically includes:

(3-1) According to the absolute value of the difference between the actual temperature and the constant temperature, it is divided into multiple temperature intervals;

(3-2) Control the injection of water into the external temperature-adjusting flow channel, adjust the temperature of each temperature-adjusting layer to the upper limit or lower limit of the current temperature range, and stop injecting water into the external temperature-adjusting flow channel;

(3-3) Determine whether the temperatures of all temperature-regulating layers have reached the upper limit or lower limit of the temperature range. If so, enter the next adjacent temperature range for temperature adjustment. If not, continue with the current judgment;

(3-4) Repeat steps (3-2) and (3-3) until the temperature of the temperature-regulating layer is adjusted to a constant temperature and the external temperature-regulating flow channel stops injecting water.
A method for constant temperature control of a trash can injection mold according to claim 4, characterized in that step 4 specifically includes:

(4-1) Real-time detection of the actual temperature of each temperature-regulating layer;

(4-2) Determine whether the actual temperature of the temperature-regulating layer exceeds the constant temperature range. If not, no temperature adjustment is performed. If the temperature of the temperature-regulating layer is adjusted step by step, until the temperature is adjusted to the constant temperature range.
A constant temperature control method for a trash can injection mold according to any one of claims 2 to 5, characterized in that the upper limit temperature is greater than the upper limit of the constant temperature range, and the lower limit temperature is less than the lower limit of the constant temperature range.
A constant temperature control method for a trash can injection mold according to claim 4, characterized in that the closer the subdivided temperature range is to the constant temperature, the smaller the temperature range is.