Control circuit of garbage can injection molding system

Abstract

The utility model discloses a control circuit of a garbage can injection molding system. The control circuit comprises a power supply input part, a main circuit and a control circuit, the power supply input part comprises three-phase power lines L1, L2 and L3, a protective ground wire PE and a circuit breaker QF; the main circuit comprises a three-phase asynchronous motor M, a thermal relay FR1, contactors KM2 and KM3 and a heating assembly R; the control circuit comprises a main switch reset loop, a plastic heating loop, a molten plastic input loop, an injection needle pressing loop and an injection needle reset loop. The garbage can injection molding system control circuit has the following beneficial effects that the garbage can injection molding system control circuit can sequentially control procedures of plastic heating, molten plastic input, injection needle downward pressing, injection needle resetting and the like according to a preset program, so that the automatic control of the garbage can injection molding process is realized, and the production efficiency and the product quality are improved.

Description

Technical Field

[0001] This utility model relates to the field of injection molding equipment control, and in particular to a control circuit for a trash can injection molding system. Background Technology

[0002] Injection molding is the main process for manufacturing products such as plastic trash cans. Its basic principle is to heat and melt plastic material, then inject it into a mold cavity under high pressure, and finally cool and solidify it to obtain the molded product. In the production of large plastic products such as trash cans, the injection molding system needs to precisely control parameters such as plastic heating temperature, injection pressure, injection speed, and cooling time to ensure product quality.

[0003] Existing trash can injection molding system control circuits typically suffer from the following problems: First, the degree of production automation is low, often requiring frequent operator intervention, increasing labor costs and operational risks; second, the injection molding process control is not precise enough, easily leading to quality defects such as uneven product wall thickness, bubbles, and shrinkage; third, the system lacks effective protection mechanisms, resulting in high equipment failure rates and high maintenance costs; fourth, production efficiency is low, making it difficult to meet the needs of mass production; and fifth, there is a lack of coordination between various processes, extending the entire manufacturing cycle.

[0004] With the increasing market demand for plastic products such as trash cans and the growing requirements for production automation, it is of great significance to develop a control circuit for a trash can injection molding system that can achieve precise control, safety, reliability, and high-efficiency production. Utility Model Content

[0005] The purpose of this invention is to provide a control circuit for a trash can injection molding system. This control circuit can control processes such as plastic heating, molten plastic input, injection needle pressing down, and injection needle resetting according to a preset program sequence, thereby realizing automated control of the trash can injection molding process and improving production efficiency and product quality.

[0006] The above-mentioned technical objective of this utility model is achieved through the following technical solution:

[0007] A control circuit for a trash can injection molding system includes: a power input section, a main circuit, and a control circuit; the power input section includes three-phase power lines L1, L2, L3, a protective ground wire PE, and a circuit breaker QF; the main circuit includes a three-phase asynchronous motor M, a thermal relay FR1, contactors KM2 and KM3, and a heating component R; the control circuit includes a main switch reset circuit, a plastic heating circuit, an input molten plastic circuit, an injection needle pressing circuit, and an injection needle reset circuit.

[0008] The present invention is further configured such that: the main switch reset circuit includes: a start button SB1; a reset button SB2; a relay KA1 and its contacts; and a normally closed contact of a time relay KT4.

[0009] The present invention is further configured such that: the plastic heating circuit includes: the contacts of relay KA1; time relay KT1; relay KM1; relay KM1 is used to control the opening and closing of heating component R.

[0010] The present invention is further configured such that the input molten plastic circuit includes: the contacts of time relay KT1; time relay KT2; solenoid valve EV; the solenoid valve EV is used to control the flow of molten plastic.

[0011] The present invention is further configured such that the injection needle pressing circuit includes: the contact of time relay KT2; time relay KT3; relay KM2; relay KM2 is used to control motor M to rotate forward and drive the injection needle to press down.

[0012] The present invention is further configured such that: the injection needle reset circuit includes: the contacts of time relay KT3; time relay KT4; relay KM3; relay KM3 is used to control motor M to reverse and drive the injection needle to reset.

[0013] The present invention is further configured such that the heating component R consists of three heating resistors for melting plastic particles.

[0014] In summary, this utility model has the following beneficial effects:

[0015] Fully automatic sequential control: The control circuit of this utility model realizes fully automated process control of plastic heating, molten plastic input, injection needle pressing down and injection needle resetting through the sequential control of time relays KT1, KT2, KT3 and KT4, which reduces manual intervention and improves production efficiency and product consistency.

[0016] Safety and reliability design: This control circuit is designed with a complete safety protection mechanism. Overload protection for the motor is provided by thermal relays FR1 and FR2 to prevent equipment damage due to overload; short circuit protection is provided by circuit breaker QF to ensure the safe operation of the entire system.

[0017] Precise timing control: By using multiple time relays in combination, precise connection between each process is ensured, avoiding material waste and quality problems caused by improper timing. It is especially suitable for injection molding of large plastic products such as trash cans.

[0018] Modular design: The control circuit adopts a functional modular design, dividing the entire injection molding process into five independent functional loops. Each loop has a clear responsibility, which facilitates fault diagnosis and system maintenance and reduces maintenance costs.

[0019] Process optimization design: The control circuit takes into account the special requirements of the trash can injection molding process. By precisely controlling the time parameters of each stage, it ensures that the plastic is fully melted, the injection pressure is moderate, and the cooling time is sufficient, thereby improving product quality and reducing the defect rate.

[0020] Energy efficiency improvement: By precisely controlling the execution time of each process, unnecessary energy consumption is avoided, such as overheating of plastics and idling of hydraulic systems, thereby improving the energy utilization efficiency of the system.

[0021] High adaptability: The control circuit has a clear structure and is easy to adjust relevant parameters according to the production needs of different sizes of trash cans. It has good adaptability and can be applied to the injection molding production of a variety of large plastic products. Attached Figure Description

[0022] Figure 1 This is a circuit diagram of the control circuit for the trash can injection molding system of this utility model. Detailed Implementation

[0023] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "page", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0025] In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified. In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0026] The present invention will be further described in detail below with reference to the accompanying drawings.

[0027] like Figure 1 As shown, a control circuit for a trash can injection molding system is provided. The control circuit mainly consists of three parts: a power input section, a main circuit, and a control circuit.

[0028] The power input section includes three-phase power lines L1, L2, and L3, and a protective earth wire PE, which are connected to the system via circuit breaker QF to provide power support for the entire system. Circuit breaker QF acts as a main switch and provides short-circuit protection, ensuring the safety of the system's electrical supply.

[0029] The main circuit primarily includes a three-phase asynchronous motor M, which drives the hydraulic system of the garbage bin injection molding system control circuit, providing the power required for injection molding. A thermal relay FR1, connected in series with motor M, is also included in the main circuit to monitor the motor's operating current. It automatically disconnects the circuit when the motor is overloaded, protecting it from damage. Contactors KM2 and KM3 control the forward and reverse rotation of motor M. The main circuit also includes a heating assembly R, which consists of three heating resistors used to melt the plastic particles. Contactor KM1 controls the opening and closing of the heating assembly R.

[0030] The control circuit is divided into five main functional circuits: main switch reset circuit, plastic heating circuit, input molten plastic circuit, injection needle pressing circuit, and injection needle reset circuit.

[0031] The main switch reset circuit includes the start button SB1, the reset button SB2, the normally closed contact KT4, and the relay KA1. When SB2 is pressed, KA1 is energized, and its contact KA1 closes to form a self-locking circuit.

[0032] The plastic heating circuit includes the contacts of relay KA1, time relay KT1, and relay KM1. When the KA1 contact closes, KT1 starts timing. During the timing process, the normally closed contact KT1 remains closed, and the normally open contact KT1 remains open. At this time, relay KM1 is energized, controlling the contactor KM1 in the main circuit to close, activating the heating component R, and heating the solid plastic granules to a molten state. When the time relay KT1 finishes timing, its normally closed contact KT1 opens, and its normally open contact KT1 closes. At this time, relay KM1 is de-energized and stops heating the plastic granules.

[0033] The molten plastic input circuit includes the contacts of time relay KT1, time relay KT2, and solenoid valve EV. When time relay KT1 finishes timing, its normally open contact KT1 closes, and time relay KT2 begins timing. During timing, the normally closed contact KT2 remains closed, while the normally open contact KT2 remains open. At this time, solenoid valve EV opens, allowing the molten plastic to flow out and enter the injection cylinder. When time relay KT2 finishes timing, its normally closed contact KT2 opens, its normally open contact KT1 closes, and solenoid valve EV is de-energized and closes.

[0034] The injection needle pressing circuit includes the contacts of time relay KT2, time relay KT3, and relay KM2. When time relay KT2 finishes timing, its normally open contact KT2 closes, and time relay KT3 starts timing. During timing, the normally closed contact KT3 of time relay KT3 remains closed, while the normally open contact KT3 remains open. At this time, relay KM2 is energized, controlling the contactor KM2 in the main circuit to close, causing motor M to rotate forward and drive the injection needle to press down, injecting molten plastic into the mold for molding. When time relay KT3 finishes timing, its normally closed contact KT3 opens, and its normally open contact KT3 closes, and the injection needle stops pressing down.

[0035] Injection needle reset circuit: This includes the contacts of time relay KT3, time relay KT4, and relay KM3. When time relay KT3 finishes timing, its normally open contact KT3 closes, and time relay KT4 starts timing. During timing, the normally closed contact KT4 of time relay KT4 remains closed, and the normally open contact KT4 remains open. Relay KM3 is energized, and contactor KM3 closes, thereby controlling the injection needle reset and completing one injection cycle. When KT4 finishes timing, its normally closed contact KT4 opens, and its normally open contact KT4 closes. This de-energizes the entire main switch reset circuit, thereby de-energizing relay KA1 and subsequently the entire control circuit. At this point, the system can prepare for the next operation, and the operator decides whether to continue with the next injection cycle.

[0036] This utility model's control circuit for a trash can injection molding system achieves automated control of the trash can injection molding process through precise timing control and multiple safety protection designs. It features simple operation, reliable process, and high safety. This system is particularly suitable for the mass production of large plastic trash cans, significantly improving production efficiency and product quality.

[0037] It should be noted that the timing of time relays KT1, KT2, KT3, and KT4 can be manually set depending on the specifications of the injection molding machine and the efficiency of the plastic particles and heating components.

[0038] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

Claims

1. A trash can injection molding system control circuit, characterized by, It comprises: a power input part, a main circuit and a control circuit; the power input part comprises three-phase power lines L1, L2, L3, a protective ground wire PE and a circuit breaker QF; the main circuit comprises a three-phase asynchronous motor M, a thermal relay FR1, contactors KM2, KM3 and a heating assembly R; the control circuit comprises a total switch reset circuit, a plastic heating circuit, an input molten plastic circuit, a syringe needle pressing down circuit and a syringe needle reset circuit.

2. The trash can injection molding system control circuit of claim 1, wherein, The total switch reset circuit comprises a start button SB1, a reset button SB2, a relay KA1 and its contact, and the normally closed contact of a time relay KT4.

3. The trash can injection molding system control circuit of claim 1, wherein, The plastic heating circuit comprises the contact of the relay KA1, a time relay KT1 and a relay KM1; the relay KM1 is used to control the opening and closing of the heating assembly R.

4. The trash can injection molding system control circuit of claim 1, wherein, The input molten plastic circuit comprises the contact of the time relay KT1, a time relay KT2 and a solenoid valve EV; the solenoid valve EV is used to control the flow of molten plastic.

5. The trash can injection molding system control circuit of claim 1, wherein, The syringe needle pressing down circuit comprises the contact of the time relay KT2, a time relay KT3 and a relay KM2; the relay KM2 is used to control the forward rotation of the motor M to drive the syringe needle to press down.

6. The trash can injection molding system control circuit of claim 1, wherein, The syringe needle reset circuit comprises the contact of the time relay KT3, a time relay KT4 and a relay KM3; the relay KM3 is used to control the reverse rotation of the motor M to drive the syringe needle to reset.

7. The trash can injection molding system control circuit of claim 1, wherein, The heating assembly R is composed of three heating resistors and is used to melt plastic particles.

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