Mold air valve control system of injection molding machine

Abstract

The invention relates to a mold air valve control system of an injection molding machine, and belongs to the technical field of injection molding machines, the mold air valve control system comprises a control module, an air valve, an input module and a sensing module, the control module is electrically connected with the air valve and instructs locking and unlocking of the air valve, and the input module is used for instructing the control module to switch among a full-automatic state, a semi-automatic state and a manual state; the sensing module is used for acquiring opening and closing of an alarm and opening and closing of a safety door and uploading the states of the alarm and the safety door to the control module, and the input module is used for inputting an automatic trigger node; when the control module is in a full-automatic mode, the air valve is instructed to be closed after the safety door is opened or glue injection is finished, and the node is automatically triggered to instruct the air valve to be opened after the safety door is closed; when the control module is in the semi-automatic mode, the air valve is instructed to be closed after glue injection is finished, and the air valve is instructed to be opened after glue injection; when the control module is in the manual mode, the control module instructs the air valve to be closed or opened under the instruction of the input module.

Description

Technical Field

[0001] The invention belongs to the technical field of injection molding machines, and in particular relates to a mold air valve control system of an injection molding machine. Background Art

[0002] An injection molding machine is a machine that injects high-temperature molten plastic raw materials into a mold cavity, allowing the molten plastic to cool and form in the mold cavity to form the corresponding product. Injection molding is roughly divided into four steps: mold closing, glue injection, mold opening, and mold demolding. Among them, pneumatic locks including air valves are required to lock the mold when closing the mold, and correspondingly, the mold needs to be locked when opening the mold.

[0003] In a general injection molding machine control system, the locking system cannot be well linked with other parts, and there is a probability that the locking cannot be performed when it is needed. For this reason, Chinese patent CN215472923U discloses a pneumatic mechanical lock control system for an injection molding machine, comprising a tail plate and a middle plate arranged side by side, a mechanical lock base is installed on the tail plate, a mechanical lock limit ruler with one end passing through the mechanical lock base is installed on the middle plate, a cylinder is installed on the mechanical lock base, and the cylinder drives the mechanical lock baffle on the mechanical lock base to rotate and interlock with the mechanical lock limit ruler; it also includes an air valve and a detection switch for detecting the position of the mechanical lock baffle, the A pressure switch is installed on the air valve, and the detection switch, air valve and pressure switch are all connected to the controller of the injection molding machine; it solves the drawbacks of the existing mechanical lock control of the injection molding machine; however, in some cases, such as when mass production is required, the injection molding machine needs to be fully automatically locked and unlocked, and when the operator needs to manually perform the entire production process or supervise the entire production process, the locking and unlocking operation authority needs to be handed over to the operating table, and the above structure does not introduce a fully automatic mode and a manual mode, and the degree of automation and operational convenience are both low. Therefore, a mold air valve control system for an injection molding machine that takes into account both the degree of automation and operational convenience is required. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a mold air valve control system for an injection molding machine, which has the characteristics of taking into account both the degree of automation and the convenience of operation.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A mold air valve control system for an injection molding machine, comprising a control module, an air valve, an input module and a sensing module, wherein the control module is electrically connected to the air valve and instructs the locking and unlocking of the air valve, the input module is used to instruct the control module to switch between full-automatic, semi-automatic and manual states, the sensing module is used to obtain the opening and closing of an alarm and the opening and closing of a safety door, and upload the states of the alarm and the safety door to the control module, and the input module is used to input an automatic trigger node;

[0007] When the control module is in full-automatic mode, it instructs the air valve to close after the safety door is opened or after the injection is completed, and instructs the air valve to open at the automatic triggering node after the safety door is closed;

[0008] When the control module is in semi-automatic mode, the air valve is commanded to close after the injection is completed, and the air valve is commanded to open after the injection;

[0009] When the control module is in manual mode, the control module instructs the closing or opening of the gas valve under the instruction of the input module.

[0010] As a preferred technical solution of the present invention, the input module is used to input the valve opening delay and the valve closing delay. When the control module is in full-automatic mode, after the safety door is closed, the air valve is instructed to open at the time point after the valve opening delay at the automatic trigger node, and the air valve is instructed to close at the time point after the valve closing delay after the injection is completed.

[0011] As a preferred technical solution of the present invention, the input module inputs the mold cavity volume, and the input module increases the valve closing delay when the mold cavity volume is greater than a threshold value, and reduces the valve closing delay when the mold cavity volume is less than the threshold value.

[0012] As a preferred technical solution of the present invention, the input module is pre-input with a mold cavity volume reference value V0, the input module is input with a current mold cavity volume V, the input module is used to input a valve opening delay T1 and a valve closing delay T2, and the input module adjusts the valve closing delay to T2×A1;

[0013] Where A1=V / V0.

[0014] As a preferred technical solution of the present invention, the input module is used to obtain the flatness of the inner surface of the mold cavity and upload the flatness data to the control module. The input module increases the valve closing delay when the mold cavity flatness is less than the threshold value, and reduces the valve closing delay when the mold cavity flatness is greater than the threshold value.

[0015] As a preferred technical solution of the present invention, the input module is pre-input with a flatness reference value Z0, the input module is used to obtain the flatness data Z of the inner surface of the mold cavity, and the input module adjusts the valve closing delay to T2×A1×A2;

[0016] Among them, A2=Z0 / Z.

[0017] As a preferred technical solution of the present invention, it also includes an alarm module, which is electrically connected to the control module. The alarm module is used to determine whether the temperature of the mold exceeds a threshold value. When the judgment result is yes, the alarm module issues an alarm and sends a signal to the control module.

[0018] As a preferred technical solution of the present invention, when the control module is in full-automatic mode, it determines whether to perform injection after receiving the alarm signal. When the judgment result is no, the control module instructs the air valve to close. When the judgment result is yes, the control module instructs the air valve to close after the injection is completed.

[0019] The beneficial effects of the present invention are:

[0020] (1) By setting the injection molding machine's air valve control system to fully automatic mode, the mold can be locked by a variety of trigger conditions. In semi-automatic mode, only the injection action triggers the mold locking. In manual mode, the mold locking is only triggered by a button, taking into account both the degree of automation and the convenience of operation.

[0021] (2) By making the input module increase the valve closing delay when the cavity volume is greater than the threshold value, and reduce the valve closing delay when the cavity volume is less than the threshold value, the probability of locking the mold when the mold closing is not fully executed is reduced when the cavity is large, the pressure during injection is greater, the probability of generating a parting line is greater, and the requirement for cavity closure is higher. When the cavity is small, the probability of generating a parting line is lower, and the requirement for cavity closure is lower, the operating efficiency is improved;

[0022] (3) By making the input module obtain flatness, when the flatness is high and the demolding difficulty is small, there is no need to further extend the valve closing delay, and the valve closing delay is not extended, thereby improving the working efficiency. When the flatness is low and the valve closing delay needs to be further increased, the valve closing delay is further extended to ensure the injection molding effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0024] Figure 1 This is a flow chart of the present invention when it is in full automatic mode;

[0025] Figure 2 is a flow chart of the present invention when it is in semi-automatic mode;

[0026] Figure 3 is a flow chart of the present invention when it is in manual mode;

[0027] Figure 4 This is a control loop block diagram of the present invention. DETAILED DESCRIPTION

[0028] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation method, structure, characteristics and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0029] See also Figure 1-4 , a mold air valve control system of an injection molding machine, comprising a control module and an air valve;

[0030] Specifically, the injection molding machine includes a movable platen, a fixed platen and an injection module. The injection module is arranged on one side of the fixed platen, and the movable platen is arranged on the other side of the fixed platen. The movable platen is driven by a driver to approach or move away from the fixed platen. When the movable platen is in close contact with the fixed platen, a mold cavity is formed. Then, an air valve locks the movable platen and the fixed platen to maintain the close contact state of the movable platen and the fixed platen. The injection module injects molten plastic into the mold cavity so that the molten plastic fills the mold cavity. After the molten plastic is molded in the mold cavity to form a product, the air valve contacts the lock of the movable platen, and the movable platen moves away from the fixed platen. The demoulding mechanism pushes the molded product away from the mold cavity to complete a round of production.

[0031] At the same time, the control module is electrically connected to the gas valve and instructs the locking and unlocking of the gas valve. In this embodiment, the injection molding machine is provided with a pneumatic lock, which is controlled by the gas valve. When the gas valve is opened, the pneumatic lock locks the movable template. When the gas valve is closed, the pneumatic lock unlocks the movable template. The control module is electrically connected to the gas valve, and the control module controls the opening and closing of the pneumatic lock by controlling the gas valve.

[0032] At the same time, the injection molding machine also includes a safety door. In this embodiment, the safety door is arranged on one side of the injection molding machine. When the safety door is closed, the space where the fixed platen and the movable platen are located is separated from the space outside the injection molding machine to prevent the operator from contacting the injection molding machine in operation and causing an accident. When the safety door is opened, the operator can directly observe the movable platen and the fixed platen, which is convenient for observation when manually operating the injection molding machine.

[0033] In the above process, different situations require different timings for locking and unlocking the moving template. For example, when mass production is required, the injection molding machine needs to be fully automatically locked and unlocked to prevent external factors from interfering with production. In debugging production or experiments, operators need to manually perform the entire production process, or supervise the entire production process. In order to ensure that the locking and unlocking operation authority is given to the operator, the input module needs to be able to directly operate the locking and unlocking. Therefore, it is necessary to introduce a fully automatic mode and a manual mode. For this purpose, an input module and a sensing module are also included.

[0034] The input module is electrically connected to the control module, and the input module is used to instruct the control module to switch between full-automatic, semi-automatic and manual states. The sensing module is used to obtain the opening and closing of the alarm and the opening and closing of the safety door, and upload the status of the alarm and the safety door to the control module. The input module is used to input the automatic trigger node;

[0035] Specifically, the input module at least includes an operation interface electrically connected to the control module. A manual operation button is provided in the input module. The button number is marked as S1 in the operation interface. At the same time, the number of the gas valve in the operation interface is marked as PC31, so that the button for operating the gas valve is distinguished from other buttons in the system of the operation interface, and the gas valve is distinguished from other devices in the operation interface. Whenever the S1 button in the input module is pressed, the input module sends a signal corresponding to the button to the control module;

[0036] At the same time, the input module provides three buttons, corresponding to the fully automatic mode, semi-automatic mode and manual mode respectively. The operator clicks the corresponding button, and then the input module sends the corresponding command to the control module;

[0037] For the control module, three sets of programs are written into the control module, and the three sets of programs correspond to the full-automatic mode, the semi-automatic mode and the manual mode respectively. When the control module receives the instruction to switch to the corresponding mode sent by the input module, the control module calls one of the programs, and the control module is set to call only one set of programs at a time to prevent the conflict of instructions in different modes;

[0038] At the same time, the control module is also electrically connected to the injection molding machine body to control the injection action of the injection molding machine, that is, to instruct the movable platen to approach or move away from the fixed platen, control the injection action of the injection module, and control the opening and closing of the air valve;

[0039] For the automatic trigger node input in the input module, the automatic trigger node can be written according to the needs of the operator, which can be mold closing or injection. After writing, the input module is written into the control module. Taking the automatic trigger node as mold closing as an example, when the control module instructs the dynamic template to see the fixed template and completes the mold closing, the trigger condition of the automatic trigger node is met;

[0040] As for the perception module, the perception module is used to obtain the opening and closing of the alarm and the opening and closing of the safety door, and upload the status of the alarm and the safety door to the control module;

[0041] For programs in the control module:

[0042] When the control module is in full-automatic mode, the sensing module uploads the status of the safety door to the control module once per second. The control module determines whether the safety door is closed. If the judgment result is no, the control module determines whether injection is in progress.

[0043] When the judgment result is that the safety door is open and the injection is finished, the control module instructs the air valve to close and release the mold clamping;

[0044] When the control module determines that the safety door is open and the injection molding is not finished, the command valve remains open to keep the mold locked until the control module determines that the injection molding is finished. When the injection molding is finished, the control module commands the valve to unlock;

[0045] When the control module determines that the safety door is closed, the control module determines whether the triggering condition of the automatic triggering node is met. When the judgment result is no, the command valve is closed, and when the judgment result is yes, the command valve is opened;

[0046] In full-automatic mode, the injection molding machine automatically triggers the locking and unlocking of the air valve according to the replaceable and adjustable automatic trigger nodes, which improves the automation of the operation.

[0047] When the control module is in semi-automatic mode, the control module determines whether to perform injection. If the determination result is yes, the control module instructs the air valve to open and maintain mold locking. When the control module determines that injection is completed or that injection is not to be performed, the control module instructs the air valve to close and release the mold locking.

[0048] In semi-automatic mode, the injection molding machine only locks and unlocks the air valve by judging the injection, so that the injection molding machine runs in automatic injection and the execution action is relatively stable, preventing the setting of the trigger action from not matching the actual production demand;

[0049] When the control module is in manual mode, the control module instructs the air valve to open and maintain mold locking when receiving the corresponding signal of the S1 button, and instructs the air valve to close and release the mold locking when not receiving the corresponding signal of the S1 button;

[0050] In manual mode, the injection molding machine only uses button S1 to lock or unlock the air valve, so that when the injection molding machine needs to be debugged or trial-produced, the operator needs to decide when to lock the air valve. The operator has absolute control over the locking and unlocking of the air valve, ensuring the convenience of operation.

[0051] By setting the injection molding machine's air valve control system to fully automatic mode, the mold clamping can be started by a variety of triggering conditions; in semi-automatic mode, only the injection action triggers the mold clamping; in manual mode, the mold clamping is only triggered by a button, taking into account both the degree of automation and the convenience of operation;

[0052] When in use, taking the full-automatic mode and the trigger action of mold closing as an example, the operator closes the safety door during normal operation to ensure the safety of the operation. At this time, the control module takes over the operation of the injection molding machine. The control module first instructs the movable template to approach the fixed template to complete mold closing. When the control module determines that the mold closing is completed, the trigger condition of the automatic trigger node is met, and then the air valve is instructed to lock the movable template and the fixed template, and the injection module is instructed to start injection. When the control module instructs the injection to end, the air valve is closed synchronously to end the mold locking. Then the control module instructs the movable template to open the mold to complete a round of production. Repeat the above steps to achieve automated mass production.

[0053] In the above process, due to delays in electrical signal transmission or mechanical transmission, there is a probability that when the control module program shows that the movable platen is in place, the movable platen is not completely in place, and it is necessary to wait for a period of time before locking the mold. At this time, the command control module uses mold closing as an automatic trigger node, and there is a probability that the air valve will lock the movable platen that is not completely in place, resulting in a mold line. Therefore, it is necessary to leave redundancy in the valve opening time to prevent the occurrence of incomplete execution and improve the injection molding quality;

[0054] Similarly, when the control module indicates that the injection is completed, due to the material properties of the molten plastic, it is necessary to wait for a certain period of time in the cavity before it is fully formed, that is, it is necessary to unlock the valve after a period of time after the injection. If the control module is unlocked immediately after the injection is completed, there is a probability that the product is not fully formed and the maintenance of the closed environment of the cavity is released. Therefore, it is necessary to leave redundancy in the valve closing time to prevent the occurrence of inadequate execution and improve the injection molding quality.

[0055] To this end, the input module is used to input the valve opening delay T1 and the valve closing delay T2;

[0056] When the control module is in full-automatic mode, after judging that the safety door is closed, the control module judges that the triggering condition of the automatic triggering node is met, and after the time point of valve opening delay, the air valve is commanded to open; at the same time, after the injection is completed, the air valve is commanded to close after the time point of valve closing delay;

[0057] By setting the valve opening delay and valve closing delay, the control module can open the valve after the valve opening delay after the automatic trigger node is triggered in the fully automatic mode, and close the valve after the valve closing delay after the injection is completed, thereby reducing the risk of inadequate execution and improving the injection quality.

[0058] In some cases, when the mold cavity volume is large, the molten plastic needs to fill the larger mold cavity in the same time, the pressure during injection is greater, the probability of producing a parting line is greater, and the mold cavity sealing requirement is higher. Therefore, it is necessary to further reduce the probability of locking the mold when the mold closing is not in place, that is, it is necessary to further increase the valve closing delay. For this purpose, the input module inputs the mold cavity volume. The input module increases the valve closing delay when the mold cavity volume is greater than the threshold, and reduces the valve closing delay when the mold cavity volume is less than the threshold.

[0059] Specifically, the input module is pre-input with a mold cavity volume reference value V0, the input module is input with a current mold cavity volume V, the input module is used to input a valve opening delay T1 and a valve closing delay T2, and the input module adjusts the valve closing delay to T2×A1, where A1=V / V0;

[0060] When the mold cavity volume is large, it means that it is necessary to further reduce the time when mold closing is not fully executed to lock the mold, that is, it is necessary to further increase the valve closing delay. At this time, the value of A1=V / V0 is large, and the value of T2×A1 is large. When the input module adjusts the valve closing delay to T2×A1, the valve closing delay is increased when the mold cavity volume is large.

[0061] When the mold cavity volume is small, it means that there is no need to further increase the valve closing delay, reduce the time spent on each operation, and improve the operation efficiency. At this time, the value of A1=V / V0 is small, and the value of T2×A1 is small. When the input module adjusts the valve closing delay to T2×A1, it is completed without further increasing the valve closing delay when the mold cavity volume is small;

[0062] By increasing the valve closing delay of the input module when the cavity volume is greater than the threshold value, and reducing the valve closing delay when the cavity volume is less than the threshold value, the probability of locking the mold when the mold closing is not fully executed is reduced when the cavity is large, the pressure during injection is greater, the probability of producing a parting line is greater, and the requirement for cavity closure is higher. When the cavity is small, the probability of producing a parting line is smaller, and the requirement for cavity closure is lower, the operating efficiency is improved.

[0063] Different molds have different products to be molded and different inner surface shapes of the mold cavities. When the inner surface shape of the mold cavity is relatively uneven, demoulding becomes more difficult. It is necessary to ensure that the product is fully formed before opening the mold to ensure smooth demoulding. Therefore, it is necessary to further delay the valve closing time to release the mold lock after the injection is completed to ensure the molding of the product in the mold cavity. Therefore, when the inner surface shape of the film cavity is relatively uneven, the valve closing delay is further increased.

[0064] The input module is pre-input with a flatness reference value Z0, and the input module is used to obtain the flatness data Z of the inner surface of the mold cavity. The input module adjusts the valve opening delay to T2×A1×A2, where A2=Z / Z0;

[0065] Specifically, the input module is used to input the shape of the mold cavity and the total area of ​​the inner surface of the mold cavity, and count the faces whose areas exceed 1% of the total area. Subsequently, the input module counts the angles between every two faces whose areas exceed 1% of the total area and the adjacent faces whose areas exceed 1% of the total area, and calculates the number of angles with angles of 0° to 30°, 31° to 60°, and 61° to 90°;

[0066] Among them, the angle of 0° to 30° means that the two surfaces forming this angle are relatively flat and do not affect the difficulty of demoulding;

[0067] An angle of 31° to 60° means that the inner wall of the mold cavity formed by the two surfaces forming this angle is relatively uneven, which has a certain impact on the difficulty of demoulding;

[0068] An angle of 61° to 90° means that the inner wall of the mold cavity formed by the two surfaces forming this angle is more uneven, which has a greater impact on the difficulty of demoulding;

[0069] At this time, when the proportion of angles between 0° and 30° is larger among several angles, the demoulding difficulty is lower, and the proportion of angles between 61° and 90° is larger, the demoulding difficulty is higher;

[0070] When the input module calculates the flatness of a mold, it counts the ratio a of the number of angles between 0° and 30° to the total number of angles, and counts the ratio b of the number of angles between 61° and 90° to the total number of angles, and calculates the value of a / b as the flatness Z;

[0071] When the flatness Z is larger, the proportion of the angle between 0° and 30° is larger, the flatness is higher, the demoulding difficulty is smaller, and there is no need to further extend the valve closing delay. At this time, A2=Z0 / Z is smaller, and the value of T2×A1×A2 is smaller. When the flatness is larger, the valve closing delay is not extended to improve the working efficiency.

[0072] The smaller the flatness Z is, the greater the proportion of the angle between 61° and 90° is, the more difficult it is to demould, and the valve closing delay needs to be further extended. At this time, A2=Z0 / Z is larger, and the value of T2×A1×A2 is larger. When the flatness is small, the valve closing delay is extended to ensure the injection molding effect.

[0073] By making the input module obtain flatness, when the flatness is high and the demoulding difficulty is lower, there is no need to further extend the valve closing delay, and the valve closing delay will not be extended, thereby improving the working efficiency. When the flatness is lower and the valve closing delay needs to be further increased, the valve closing delay can be further extended to ensure the injection molding effect.

[0074] There is a probability of failure during injection molding, and at this time, the operator needs to be reminded. For this purpose, it also includes an alarm module, which is electrically connected to the control module. The alarm module is used to determine whether the temperature of the mold exceeds the threshold. When the judgment result is yes, the alarm module issues an alarm and sends a signal to the control module. Specifically, the alarm module at least includes a temperature sensor and an audible and visual alarm that are electrically connected to each other. The temperature sensor detects the temperature of the mold. When the temperature sensor determines that the temperature exceeds the threshold, the temperature sensor sends an alarm signal to the control module and the audible and visual alarm. After receiving the alarm signal, the audible and visual alarm synchronously sends an alarm to remind the operator.

[0075] When the alarm signal is issued, the automated operation needs to be stopped to prevent the factors that trigger the alarm from affecting the injection molding production. To this end, when the control module is in full-automatic mode, it determines whether to perform injection molding after receiving the alarm signal. If the control module determines that the result is no, it instructs the air valve to close. If the control module determines that the result is yes, it instructs the air valve to close after the injection molding is completed.

[0076] During the injection process, the mold cavity needs to be kept closed. At this time, the air valve needs to be kept open to maintain the mold locking state. Therefore, when the control module determines that injection is in progress after receiving the alarm signal, it does not perform additional actions and instructs the air valve to close after the injection is completed. In other cases, the air valve is instructing to close after receiving the alarm signal.

[0077] The working principle and use process of the present invention:

[0078] When in use, taking the full-automatic mode and the trigger action of mold closing as an example, the operator closes the safety door during normal operation to ensure the safety of the operation. At this time, the control module takes over the operation of the injection molding machine. The control module first instructs the movable template to approach the fixed template to complete mold closing. When the control module determines that the mold closing is completed, the trigger condition of the automatic trigger node is met, and then the air valve is instructed to lock the movable template and the fixed template, and the injection module is instructed to start injection. When the control module instructs the injection to end, the air valve is closed synchronously to end the mold locking. Then the control module instructs the movable template to open the mold to complete a round of production. Repeat the above steps to achieve automated mass production.

[0079] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A mold valve control system for an injection molding machine, characterized in that: It includes a control module, an air valve, an input module and a sensing module. The control module is electrically connected to the air valve and instructs the locking and unlocking of the air valve. The input module is used to instruct the control module to switch between full-automatic, semi-automatic and manual states. The sensing module is used to obtain the opening and closing of the alarm and the opening and closing of the safety door, and upload the status of the alarm and the safety door to the control module. The input module is used to input the automatic trigger node; When the control module is in full-automatic mode, it commands the air valve to close after the safety door is opened or the injection is completed, and automatically triggers the node to command the air valve to open after the safety door is closed; When the control module is in semi-automatic mode, the air valve is commanded to close after the injection is completed, and the air valve is commanded to open after the injection; When the control module is in manual mode, the control module instructs the closing or opening of the gas valve under the instruction of the input module.

2. The mold valve control system of an injection molding machine according to claim 1, characterized in that: The input module is used to input the valve opening delay and the valve closing delay. When the control module is in the fully automatic mode, after the safety door is closed, the air valve is instructed to open at the time point of the automatic trigger node after the valve opening delay, and the air valve is instructed to close at the time point of the valve closing delay after the injection is completed.

3. The mold valve control system of an injection molding machine according to claim 1, characterized in that: The input module inputs a mold cavity volume, and the input module increases the valve closing delay when the mold cavity volume is greater than a threshold value, and reduces the valve closing delay when the mold cavity volume is less than the threshold value.

4. The mold valve control system of an injection molding machine according to claim 3, characterized in that: The input module is pre-input with a mold cavity volume reference value V0, the input module is input with a current mold cavity volume V, the input module is used to input a valve opening delay T1 and a valve closing delay T2, and the input module adjusts the valve closing delay to T2×A1; Where A1=V / V0.

5. The mold valve control system of an injection molding machine according to claim 4, characterized in that: The input module is used to obtain the flatness of the inner surface of the mold cavity and upload the flatness data to the control module. The input module increases the valve closing delay when the mold cavity flatness is less than the threshold, and reduces the valve closing delay when the mold cavity flatness is greater than the threshold.

6. The mold valve control system of an injection molding machine according to claim 5, characterized in that: The input module is pre-input with a flatness reference value Z0, the input module is used to obtain the flatness data Z of the inner surface of the mold cavity, and the input module adjusts the valve closing delay to T2×A1×A2; Among them, A2=Z0 / Z.

7. The mold valve control system of an injection molding machine according to claim 1, characterized in that: It also includes an alarm module, which is electrically connected to the control module. The alarm module is used to determine whether the temperature of the mold exceeds a threshold value. When the judgment result is yes, the alarm module issues an alarm and sends a signal to the control module.

8. The mold valve control system of an injection molding machine according to claim 7, characterized in that: When the control module is in full-automatic mode, after receiving the alarm signal, it determines whether to perform injection. When the determination result is no, the control module instructs the air valve to close. When the determination result is yes, the control module instructs the air valve to close after injection is completed.

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