Injection hydraulic control circuit of a two-color injection molding machine

Abstract

The present invention relates to the technical field of injection hydraulic control circuits, and specifically discloses an injection hydraulic control circuit for a two-color injection molding machine, which includes a first hydraulic pump, a second hydraulic pump, a switching valve, a control valve, a cartridge valve, and a pilot valve. The control valve can control the communication oil path inside the switching valve. Then, during color mixing injection molding, the first energized end of the control valve loses power. At this time, the first hydraulic pump with a larger displacement supplies liquid to the main injection unit, and the second hydraulic pump supplies liquid to the auxiliary injection unit, meeting the injection speed requirements of the main injection unit and the auxiliary injection unit during color mixing injection molding. During sandwich injection molding, the first energized end of the control valve is energized. At this time, the second hydraulic pump with a smaller displacement supplies liquid to the main injection unit, and the second hydraulic pump with a larger displacement supplies liquid to the auxiliary injection unit to meet the injection speed requirements of the main injection unit and the auxiliary injection unit during sandwich injection molding, realizing that one hydraulic oil path controls the injection molding machine to perform two injection molding processes.

Description

Technical Field

[0001] The present invention relates to the technical field of two-color injection molding machines, and particularly refers to an injection hydraulic control circuit of a two-color injection molding machine. Background Art

[0002] With the rapid development of manufacturing technology, the types of injection molding processes of injection molding machines are increasing. To meet the requirements of two-color products, two-color injection molding machines have emerged. In the prior art, the application scope of two-color injection molding machines is very wide. Taking mixed-color injection molding and sandwich injection molding as examples, a two-color injection molding machine can be used as a mixed-color machine or a sandwich machine, and the requirements of two colors are met through the main injection unit and the auxiliary injection unit on the two-color injection molding machine. However, since the mixed-color injection molding process and the sandwich injection molding process have different requirements for injection speed, it is often necessary to set two sets of hydraulic control circuits in the two-color injection molding machine, and the two sets of hydraulic control circuits are used to control the two-color injection molding machine to perform mixed-color injection molding and sandwich injection molding respectively, which results in a very high overall cost of the two-color injection molding machine and poor market competitiveness. Summary of the Invention

[0003] The present invention is made in consideration of the foregoing problems, and the object of the invention is to provide an injection hydraulic control circuit of a two-color injection molding machine, which can realize switching the first hydraulic pump and the second hydraulic pump to provide injection power for the main injection unit or the auxiliary injection unit to meet the injection rate under different injection molding processes, and the power provided by the first hydraulic pump and the second hydraulic pump can be superimposed to further meet the demand for rapid injection, and the cost is relatively low.

[0004] To achieve the above object, the present invention provides an injection hydraulic control circuit of a two-color injection molding machine. The two-color injection molding machine is provided with a main injection unit and an auxiliary injection unit. The injection hydraulic control circuit includes a first hydraulic pump, a second hydraulic pump, a switching valve group and a superimposing valve group. The displacement of the first hydraulic pump is greater than that of the second hydraulic pump;

[0005] The switching valve group includes a switching valve and a control valve. The switching valve is provided with a first oil inlet, a second oil inlet, a first oil outlet and a second oil outlet. The first hydraulic pump is connected to the first oil inlet through a first pipeline, the second hydraulic pump is connected to the second oil inlet through a second pipeline, the first oil outlet is connected to the main injection unit through a third pipeline, and the second oil outlet is connected to the auxiliary injection unit through a fourth pipeline. The control valve is provided with a first energized end. When the first energized end is de-energized, the first oil inlet is connected to the first oil outlet, and the second oil inlet is connected to the second oil outlet. When the first energized end is energized, the first oil inlet is connected to the second oil outlet, and the second oil inlet is connected to the first oil outlet;

[0006] The stacked valve group includes cartridge valves, which are used to connect the third pipeline and the fourth pipeline. When the cartridge valves are opened, the third pipeline and the fourth pipeline are connected.

[0007] The two-color injection molding machine has a first injection state and a second injection state. When the two-color injection molding machine is in the first injection state, the first energized terminal loses power. When the two-color injection molding machine is in the second injection state, the first energized terminal is energized.

[0008] In a two-color injection molding machine injection hydraulic control circuit as described above, the stacked valve group further includes a pilot valve, and the pilot valve is provided with a second energized terminal. When the second energized terminal loses power, the pilot valve controls the cartridge valve to close. When the second energized terminal is energized, the pilot valve controls the cartridge valve to open.

[0009] In a two-color injection molding machine injection hydraulic control circuit as described above, it further includes a first pressure gauge, a first pressure sensor, a second pressure gauge, and a second pressure sensor. The first pressure gauge and the first pressure sensor are both connected to the first pipeline, and the second pressure gauge and the second pressure sensor are both connected to the second pipeline.

[0010] The present invention has the following beneficial effects: By controlling the valve, the communication oil circuit inside the switching valve can be controlled. Furthermore, during color mixing injection molding, the first energized terminal of the control valve remains de-energized. At this time, the first hydraulic pump with a larger displacement supplies liquid to the main injection unit, and the second hydraulic pump supplies liquid to the auxiliary injection unit, meeting the injection speed requirements of the main injection unit and the auxiliary injection unit during color mixing injection molding. During sandwich injection molding, the first energized terminal of the control valve remains energized. At this time, the second hydraulic pump with a smaller displacement supplies liquid to the main injection unit, and the second hydraulic pump with a larger displacement supplies liquid to the auxiliary injection unit to meet the injection speed requirements of the main injection unit and the auxiliary injection unit during sandwich injection molding, realizing that one hydraulic oil circuit controls the injection molding machine to perform two injection molding processes. And during the injection molding process, the stacked valve group can control two hydraulic pumps to supply liquid to the same injection unit, which can meet the high-speed requirements and realize injection speed increase. Description of the Drawings

[0011] Figure 1 It is a schematic diagram of the hydraulic control circuit of the embodiment.

[0012] In the figure: 1. Main injection unit; 2. Auxiliary injection unit; 3. First hydraulic pump; 4. Second hydraulic pump; 5. Switching valve; 6. Control valve; 61. First energized terminal; 7. Cartridge valve; 8. Pilot valve; 81. Second energized terminal; 9. First pressure gauge; 10. First pressure sensor; 11. Second pressure gauge; 12. Second pressure sensor; 13. First pipeline; 14. Second pipeline; 15. Third pipeline; 16. Fourth pipeline. Detailed implementation mode

[0013] The following are specific embodiments of the present invention. In combination with the accompanying drawings, the technical solutions of the present invention will be further described, but the invention is not limited to these embodiments.

[0014] As Figure 1 shown, an injection hydraulic control circuit of a two-color injection molding machine includes a first hydraulic pump 3, a second hydraulic pump 4, a switching valve group, and a stacking valve group. The displacement of the first hydraulic pump 3 is greater than that of the second hydraulic pump 4, that is, the power provided by the first hydraulic pump 3 is greater than the power provided by the second hydraulic pump 4.

[0015] Specifically, the switching valve group includes a switching valve 5 and a control valve 6. The switching valve 5 is provided with a first oil inlet, a second oil inlet, a first oil outlet, and a second oil outlet. The first hydraulic pump 3 is connected to the first oil inlet through a first pipeline 13, and the second hydraulic pump 4 is connected to the second oil inlet through a second pipeline 14; generally, a main injection unit 1 and a sub-injection unit 2 are provided on the two-color injection molding machine. The first oil outlet is connected to the main injection unit 1 through a third pipeline 15, and the second oil outlet is connected to the sub-injection unit 2 through a fourth pipeline 16. That is, the hydraulic oil coming out of the first oil outlet can enter the main injection unit 1 to drive the main injection unit 1 to perform an injection action, and the hydraulic oil coming out of the second oil outlet can enter the sub-injection unit 2 to drive the sub-injection unit 2 to perform an injection action. A first energized end 61 is provided on the control valve 6. When the first energized end 61 is de-energized, the first oil inlet is connected to the first oil outlet, and the second oil inlet is connected to the second oil outlet. When the first energized end 61 is energized, the first oil inlet is connected to the second oil outlet, and the second oil inlet is connected to the first oil outlet. By the energization and de-energization of the first energized end 61, the first hydraulic pump 3 can supply liquid to the sub-injection unit 2 or to the main injection unit 1, so as to be suitable for different injection molding processes.

[0016] Due to the versatility of the two-color injection molding machine, the two-color injection molding machine has a first injection state and a second injection state. The first injection state refers to the state in which the two-color injection molding machine is used for mixed-color injection molding, and the second injection state refers to the state in which the two-color injection molding machine is used for sandwich injection molding. Taking the first injection state as an example, during mixed-color injection molding, the first energized end 61 is de-energized. At this time, the first oil inlet of the switching valve 5 is connected to the first oil outlet, and the first hydraulic pump 3 supplies oil to the main injection unit 1, and the second hydraulic pump 4 supplies oil to the sub-injection unit 2.

[0017] Furthermore, there are four injection methods in the color mixing injection molding. First, the main injection unit 1 injects first, and then the secondary injection unit 2 injects; second, the secondary injection unit 2 injects first, and then the main injection unit 1 injects. In these two injection methods, no coating layer will be formed during the sequential injection, and the two materials are mixed together; third, the main injection unit 1 keeps injecting all the time, and then the secondary injection unit 2 injects occasionally according to the agreed time; fourth, the secondary injection unit 2 keeps injecting all the time, and then the main injection unit 1 injects occasionally according to the agreed time. Among these four injection methods, the injection rate requirement of the main injection unit 1 is relatively high. Therefore, during this process, the first hydraulic pump 3 with large power always supplies oil to the main injection unit 1, and the second hydraulic pump 4 with small power supplies oil to the secondary injection unit 2.

[0018] In this embodiment, the stacking valve group includes the cartridge valve 7 and the pilot valve 8. The cartridge valve 7 is used to connect the third pipeline 15 and the fourth pipeline 16. A second energized end 81 is provided on the pilot valve 8. When the second energized end 81 loses power, the pilot valve 8 controls the cartridge valve 7 to close. When the second energized end 81 is energized, the pilot valve 8 controls the cartridge valve 7 to open. At this time, the third pipeline 15 and the fourth pipeline 16 are connected.

[0019] When the two-color injection molding machine is in the second injection state, the first energized end 61 is energized. At this time, the first oil inlet is connected to the second oil outlet, and the second oil inlet is connected to the first oil outlet. The hydraulic oil provided by the first hydraulic pump 3 is discharged from the second oil outlet, and the hydraulic oil provided by the second hydraulic pump 4 is discharged from the first oil outlet. At this time, the injection molding machine is in the state of sandwich injection molding. The injection of sandwich injection molding includes three steps in total. The first step is to control the main injection unit 1 to inject. For example, the outer shell of the product is injection molded first. During this process, the injection rate requirement is very high. Therefore, during this process, the second energized end 81 is energized, the pilot valve 8 controls the cartridge valve 7 to open, and the first hydraulic pump 3 and the second hydraulic pump 4 supply oil to the main injection unit 1 at the same time to ensure its relatively large injection speed. The second step is to control the secondary injection unit 2 to inject and injection mold the inner core of the product. During this process, the injection rate requirement is relatively high. Therefore, the first hydraulic pump 3 with large power is used to supply oil to the secondary injection unit 2 alone. The third step is to control the main injection unit 1 to inject to seal the molded product. During this process, the injection rate requirement is relatively low. Therefore, the second hydraulic pump 4 with small power is used to supply oil to the main injection unit 1 alone.

[0020] In this embodiment, the hydraulic control circuit further includes a first pressure gauge 9, a first pressure sensor 10, a second pressure gauge 11, and a second pressure sensor 12. The first pressure gauge 9 and the first pressure sensor 10 are both connected to the first pipeline 13, and the second pressure gauge 11 and the second pressure sensor 12 are both connected to the second pipeline 14. The pressure values of the first hydraulic pump 3 and the second hydraulic pump 4 can be directly displayed through the first pressure gauge 9 and the second pressure gauge 11, and the pressure values of the first hydraulic pump 3 and the second hydraulic pump 4 can be fed back to the control system through the first pressure sensor 10 and the second pressure sensor 12, so as to facilitate real-time pressure control.

[0021] The technical solutions of the present invention have been described in detail above in conjunction with the accompanying drawings. The described embodiments are used to help understand the idea of the present invention. The specific embodiments described herein are merely illustrative examples of the spirit of the present invention. Those skilled in the art of the present invention can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0022] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0023] In addition, in the present invention, descriptions such as "first", "second", and "one" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0024] In the present invention, unless otherwise clearly defined and limited, terms such as "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0025] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on what can be achieved by those of ordinary skill in the art. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. An injection hydraulic control circuit for a two-color injection molding machine, wherein the two-color injection molding machine is provided with a main injection unit and a sub-injection unit, characterized in that, The injection hydraulic control circuit includes a first hydraulic pump, a second hydraulic pump, a switching valve group, and a stacking valve group. The displacement of the first hydraulic pump is greater than that of the second hydraulic pump. The switching valve group includes a switching valve and a control valve. The switching valve is provided with a first oil inlet, a second oil inlet, a first oil outlet, and a second oil outlet. The first hydraulic pump is connected to the first oil inlet through a first pipeline, the second hydraulic pump is connected to the second oil inlet through a second pipeline, the first oil outlet is connected to the main injection unit through a third pipeline, and the second oil outlet is connected to the sub-injection unit through a fourth pipeline. The control valve is provided with a first energized end. When the first energized end is de-energized, the first oil inlet is connected to the first oil outlet, and the second oil inlet is connected to the second oil outlet. When the first energized end is energized, the first oil inlet is connected to the second oil outlet, and the second oil inlet is connected to the first oil outlet. The stacking valve group includes a cartridge valve, and the cartridge valve is used to connect the third pipeline and the fourth pipeline. When the cartridge valve is opened, the third pipeline is connected to the fourth pipeline. The two-color injection molding machine has a first injection state and a second injection state. When the two-color injection molding machine is in the first injection state, the first energized end is de-energized. When the two-color injection molding machine is in the second injection state, the first energized end is energized.

2. The injection hydraulic control circuit of a two-color injection molding machine according to claim 1, wherein The stacking valve group further includes a pilot valve. The pilot valve is provided with a second energized end. When the second energized end is de-energized, the pilot valve controls the cartridge valve to close. When the second energized end is energized, the pilot valve controls the cartridge valve to open.

3. A dual-color injection molding machine injection hydraulic control circuit according to claim 1, characterized in that, It further includes a first pressure gauge, a first pressure sensor, a second pressure gauge, and a second pressure sensor. The first pressure gauge and the first pressure sensor are both connected to the first pipeline, and the second pressure gauge and the second pressure sensor are both connected to the second pipeline.

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