Oil supplementing control system for injection cylinder of injection molding machine

Abstract

The utility model relates to an oil recharging control system for an injection cylinder of an injection molding machine. The oil recharging control system comprises a three-position four-way electromagnetic directional valve, a two-position four-way electromagnetic directional valve, a two-way logic valve, a pilot overflow valve, a one-way throttle valve, a material storage motor, an injection oil cylinder and a screw charging barrel assembly. The electromagnetic directional valve, the two-way logic valve, the pilot overflow valve and the one-way throttle valve are respectively connected with the injection oil cylinder and the storage motor through pipelines, and the injection oil cylinder, the storage motor and the screw charging barrel assembly are connected through shaft and key parts. The utility model has the characteristics of controllable oil recharging quantity of the injection oil cylinder, accurate control of material storage back pressure, wide applicable machine types, high universality and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of oil circuit control, in particular to an oil circuit control system for an injection molding machine. Background Art

[0002] Over the years, the injection molding machine industry has been booming and developing rapidly, and technology has been constantly reforming and innovating. In order to produce different types of plastic products with better quality, continuously improving the performance of injection molding machines and reducing manufacturing costs have become the main direction of the industry. The injection part, which measures the important performance of the machine, is one of the core components of the injection molding machine. Therefore, various types and structures of injection molding machines such as double-cylinder injection, single-cylinder injection, double-rod injection, and proportional injection have emerged in an endless stream. Therefore, the oil circuit control system that provides power to the machine has also been constantly changing with the changes in different injection types, resulting in a wide variety of oil circuit control systems and poor versatility. In view of the above working conditions, a solution for an oil circuit control system with accurate storage back pressure control, wide applicability, and high versatility is proposed. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide an injection molding machine injection cylinder oil replenishment control system, which has the characteristics of controllable injection cylinder oil replenishment amount, accurate material storage back pressure control, wide application models, high versatility, etc.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] An injection molding machine injection cylinder oil replenishment control system includes a three-position four-way electromagnetic reversing valve, a two-position four-way electromagnetic reversing valve, a two-way logic valve, a pilot relief valve, a one-way throttle valve, a storage motor, an injection cylinder and a screw barrel assembly. The three-position four-way electromagnetic reversing valve, the two-position four-way electromagnetic reversing valve, the two-way logic valve, the pilot relief valve and the one-way throttle valve are installed on an integrated oil circuit board and are respectively connected to the storage motor and the injection cylinder through pipelines. The injection cylinder, the storage motor and the screw barrel assembly are connected through shafts and key components.

[0006] The three-position four-way electromagnetic reversing valve controls the forward and backward movement of the injection cylinder through the pipeline.

[0007] The two-position four-way electromagnetic reversing valve controls the rotation and stop of the storage motor through the pipeline.

[0008] The one-way throttle valve is a series one-way throttle valve, that is, the hydraulic oil can flow in one direction, and the flow rate is controlled by the throttle valve, and the reverse flow is cut off and cannot flow.

[0009] The one-way throttle valve is connected to the return oil at one end through the oil circuit integrated block, and the one-way cut-off end is connected to the injection cylinder rubber extraction chamber, that is, hydraulic oil is allowed to flow from the return oil side through the one-way throttle valve into the injection cylinder rubber extraction chamber, while the reverse direction is cut off.

[0010] Beneficial effects: The utility model relates to an injection cylinder oil replenishment control system, and the specific beneficial effects are as follows:

[0011] (1) The oil circuit control system of the present invention is an upgrade and modification of the original traditional oil circuit system. The mechanical structure, computer program, point control, etc. do not need to be modified at all. The machine that has been produced or used can be directly upgraded and modified to improve the machine performance.

[0012] (2) Regardless of the injection structure, such as single-cylinder injection, double-cylinder injection, or double-rod injection, when storing materials, the injection cylinder can adjust the appropriate amount of oil replenishment through a one-way throttle valve. This eliminates the impact of the huge difference in oil replenishment caused by different injection structures on the back pressure of the stored materials, achieves uniform filling of the molten material, and achieves the purpose of precise injection.

[0013] (3) The proportional reversing valve does not have the functional structure of the conventional electromagnetic reversing valve. When the conventional oil circuit control system changes the ordinary injection to the proportional injection, it is necessary to redo the oil replenishment system of the injection cylinder during the material storage. However, the utility model only needs to interchange the ordinary electromagnetic reversing valve with the proportional reversing valve to realize the arbitrary switching between ordinary injection and proportional injection, without replacing the integrated oil circuit block or making a separate oil replenishment system for the injection cylinder.

[0014] (4) The oil circuit control system of the utility model has no requirements on the injection type, injection cylinder structure, etc. of the existing injection molding machine, and can realize precise control of the oil replenishment amount of the injection cylinder. It has high versatility and is beneficial to promotion within the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a structural view of the single-cylinder injection hydraulic oil circuit of the utility model;

[0016] Figure 2 This is a structural view of the double-cylinder injection hydraulic oil circuit of the utility model;

[0017] Figure 3 This is a structural view of the proportional injection hydraulic oil circuit of the utility model;

[0018] Figure 4 This is a structural view of the existing conventional single-cylinder injection hydraulic oil circuit;

[0019] Figure 5 This is a structural view of the existing conventional double-cylinder injection hydraulic oil circuit;

[0020] Diagram: 1. Three-position four-way solenoid directional valve, 2. Two-position four-way solenoid directional valve, 3. Two-way logic valve, 4. Pilot relief valve, 5. Storage motor, 6. Screw barrel assembly, 7. Injection cylinder, 8. One-way throttle valve, 9. Proportional directional valve, 10. Three-position four-way solenoid directional valve. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

[0022] The implementation mode of the utility model relates to an injection cylinder oil replenishment control system for an injection molding machine. The characteristics of the utility model are described by comparing with the original traditional oil circuit system.

[0023] like Figure 1 and Figure 2 As shown, in the oil circuit control system of the utility model, when the three-position four-way electromagnetic reversing valve 1 is in the normal position, the four oil ports of PTAB are not connected to each other, and it is connected to the injection cylinder 7 through a pipeline to control the forward and backward movement of the injection cylinder 7. The two-position four-way electromagnetic reversing valve 2 is connected to the storage motor 5 and the injection chamber of the injection cylinder 7 through a pipeline to control the rotation and stop of the storage motor 5. When the storage motor 5 rotates, the screw barrel assembly 6 will push the injection cylinder 7 backward due to the reaction force of the molten material. After the hydraulic oil in the injection chamber of the injection cylinder 7 passes through the two-position four-way electromagnetic reversing valve 2, it is given a certain return oil pressure under the joint action of the two-way logic valve 3 and the pilot relief valve 4, thereby ensuring that the molten material has a certain filling density, and the hydraulic oil in the return oil chamber will be filled into the glue extraction chamber of the injection cylinder 7 through the one-way throttle valve 8, thereby ensuring that the injection cylinder 7 will not inhale vacuum during the backward process and can run smoothly.

[0024] like Figure 4 and Figure 5 As shown in the figure, in the conventional hydraulic oil circuit structure, when the three-position four-way electromagnetic reversing valve 10 is in the normal position, A and T are connected, and it is connected to the injection cylinder 7 through a pipeline to control the forward and backward movement of the injection cylinder 7. When the storage motor 5 rotates, the screw barrel assembly 6 will push the injection cylinder 7 backward due to the reaction force of the melt, and the return oil pressure of the injection chamber is controlled and Figure 1 and Figure 2 The same, and the glue extraction chamber is filled with hydraulic oil through the AT oil port of the three-position four-way solenoid reversing valve 10.

[0025] like Figure 1 , 2, 4, and 5, by comparison, it can be found that, in the case of material storage, the amount of oil added to the glue extraction chamber cannot be controlled in the existing conventional oil circuit control system, while the oil circuit control system of the utility model can accurately adjust the amount of oil added through the one-way throttle valve 8. Figure 2 and Figure 5 ), the injection flow rate of the injection cylinder 7 will be relatively large, and the injection cylinder is a single cylinder structure (such as Figure 1 and Figure 4 ) or double-rod structure (such as Figure 3 ), the replenishment flow rate of the injection cylinder 7 will be relatively small. If the replenishment flow rate of the injection cylinder 7 is less than the actual required replenishment amount, the glue extraction chamber will absorb vacuum, causing the injection cylinder 7 to move unsteadily during material storage, or even unable to retreat, affecting the molten material filling and glue extraction delay. If the replenishment flow rate of the injection cylinder 7 is greater than the actual required replenishment amount, the glue extraction chamber will push the injection cylinder backward, causing the screw barrel assembly 6 to be unevenly filled with molten material, or even not filled. The above situations will lead to problems with the filling of the molten material, thereby affecting the qualified rate of the product, causing material waste and increased costs.

[0026] In some cases, we will increase the power system of the machine, that is, the system flow, to meet the special requirements of customers, but in order to reduce costs, we will not increase the size of the pipeline, hydraulic manifold, and hydraulic valve. Figure 4 , Figure 5 If the conventional oil circuit control is used, the return oil volume will increase when the storage motor 5 is working, and the excessive return oil will rush into the glue extraction cavity of the injection cylinder 7 through the AT oil port of the three-position four-way electromagnetic reversing valve 10, pushing the injection cylinder 7 to retreat quickly, causing the molten material filling in the screw barrel assembly 6 to fail to reach the ideal density, thereby causing defective plastic products to be produced. However, with the oil circuit control system of the utility model, the adjustment function of the one-way throttle valve 8 can be used to make the injection cylinder 7 glue extraction cavity replenishment flow rate within a suitable range, so that the injection cylinder 7 can retreat smoothly completely relying on the reaction force of the molten material filling to achieve the ideal filling density, thereby greatly improving the product qualification rate.

[0027] like Figure 3 As shown in the figure, when producing precision products or high-speed injection, we need to use a proportional reversing valve 9 to achieve precise injection control. However, the proportional reversing valve is different from the ordinary electromagnetic reversing valve. It does not have the AT intercommunication function. Figure 4 , Figure 5 Conventional oil circuit control requires an additional oil replenishment system to complete the oil replenishment action of the injection cylinder during material storage. However, with the oil circuit control system of the utility model, it can be achieved by directly replacing the three-position four-way electromagnetic reversing valve 1 with a proportional reversing valve 9, simplifying the machine manufacturing process and reducing production costs.

Claims

1. An injection molding machine injection cylinder oil replenishment control system, comprising a three-position four-way electromagnetic reversing valve (1), a two-position four-way electromagnetic reversing valve (2), a two-way logic valve (3), a pilot relief valve (4), a one-way throttle valve (8), a storage motor (5), an injection cylinder (7) and a screw barrel assembly (6), characterized in that: The three-position four-way electromagnetic reversing valve (1), the two-position four-way electromagnetic reversing valve (2), the two-way logic valve (3), the pilot relief valve (4), and the one-way throttle valve (8) are installed on the integrated oil circuit board and are respectively connected to the storage motor (5) and the injection cylinder (7) through pipelines. The injection cylinder (7), the storage motor (5) and the screw barrel assembly (6) are connected through shafts and key components.

2. The oil replenishment control system for the injection cylinder of an injection molding machine according to claim 1, characterized in that: The three-position four-way electromagnetic reversing valve (1) controls the forward and backward movement of the injection cylinder (7) through a pipeline.

3. The oil replenishment control system for the injection cylinder of an injection molding machine according to claim 1, characterized in that: The two-position four-way electromagnetic reversing valve (2) controls the rotation and stop of the storage motor (5) through the pipeline.

4. The oil replenishment control system for the injection cylinder of an injection molding machine according to claim 1, characterized in that: The two-way logic valve (3) and the pilot relief valve (4) work together to control the return oil pressure of the injection chamber of the injection cylinder (7) during material storage.

5. The oil replenishment control system for the injection cylinder of an injection molding machine according to claim 1, characterized in that: The one-way throttle valve (8) is a series one-way throttle valve, that is, the hydraulic oil can flow in one direction, and the flow rate is controlled by the throttle valve, and the reverse direction is blocked and cannot flow.

6. The injection molding machine injection cylinder oil replenishment control system according to claim 1, characterized in that: The one-way throttle valve (8) is connected to the return oil at one end through the oil circuit integrated block, and is connected to the injection cylinder (7) glue extraction chamber at one end through the one-way throttle valve, that is, hydraulic oil is allowed to flow from the return oil side through the one-way throttle valve into the injection cylinder glue extraction chamber, while the reverse flow is cut off.

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