Hydraulic control loop of secondary injection unit of double-colored injection molding machine

Abstract

The utility model relates to the technical field of hydraulic control loops, and particularly discloses a hydraulic control loop of an auxiliary injection unit of a double-colored injection molding machine, which comprises an auxiliary injection oil cylinder, a system oil port, an oil tank, an electromagnetic directional valve and an auxiliary storage motor, the system oil port can be communicated with a rod cavity of the auxiliary injection oil cylinder or an oil inlet of the auxiliary storage motor through the electromagnetic direction valve, an oil outlet of the auxiliary storage motor is communicated with the oil tank, and a reset spring is arranged in the auxiliary injection oil cylinder. The system oil port can drive the piston rod and the auxiliary screw rod to perform injection action by introducing hydraulic oil into the rod cavity of the auxiliary injection oil cylinder, and after injection is completed, the reset spring can drive the auxiliary screw rod to perform injection retreating action through the piston rod, so that a control loop can be simplified, the control loop and the main injection unit are suitable for the same power system, the cost can be saved, and the production efficiency is improved. The occupied space is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of double -color injection molding machine, especially a kind of hydraulic control circuit of double -color injection molding machine vice injection unit. BACKGROUND

[0002] Double -color injection molding is also called double -color injection molding, which is a kind of molding method for injecting two different color plastics into the same mold, which can make the molded parts present two different colors, and can improve the practicability and aesthetic property of plastic parts;The process of double -color injection molding is usually implemented by double -color injection molding machine, and the existing double -color injection molding machine is usually equipped with two sets of structure, and the plastic injection device with completely same or partially similar specifications, in the double -color injection molding process, first, the first set of plastic injection device injects the first color plastic melt into a part of cavity in mold, after the first color plastic melt is cooled and solidified, mold is rotated or moved, so that the solidified part is aligned with the injection port of the second set of injection device, then, the second set of plastic injection device injects the second color plastic melt into another part of cavity in mold, finally, after pressure maintaining, cooling and other processes, the double -color injection molding product is taken out by opening mold.

[0003] And the existing vice injection unit control oil circuit is complex, cannot adopt the same power system of main injection unit, so two sets of power systems are often designed for separate control, which can cause high production cost of double -color injection molding machine, and cannot meet the needs of ordinary double -color machine customers. SUMMARY

[0004] The utility model makes in view of the foregoing problem, and the utility model aims at providing a kind of hydraulic control circuit of double -color injection molding machine vice injection unit, and the automatic reset of piston rod of vice injection oil cylinder with spring can be realized, and oil is not needed to be supplied to the rodless cavity of vice injection oil cylinder, so as to simplify oil circuit.

[0005] To achieve the above object, the utility model provides a kind of hydraulic control circuit of double -color injection molding machine vice injection unit, the vice injection unit includes vice screw, the hydraulic control circuit includes vice injection oil cylinder, system oil port, oil tank, electromagnetic directional valve and vice storage motor, the piston rod one end of vice injection oil cylinder is connected with vice screw, the system oil port can be communicated with the rod cavity of vice injection oil cylinder or with the oil inlet of vice storage motor by electromagnetic directional valve, the oil outlet of vice storage motor is communicated with oil tank;

[0006] Reset spring is arranged in the rod cavity of vice injection oil cylinder, the reset spring is sleeved on the outside of piston rod, and is used to drive the reset of piston rod;

[0007] The electromagnetic directional valve is provided with a first electromagnet and a second electromagnet. When the first electromagnet is powered, the system oil port can communicate with the rod cavity of the auxiliary injection oil cylinder through the electromagnetic directional valve, the piston rod can drive the auxiliary screw rod to perform an injection action, and the reset spring can be stretched. When the second electromagnet is powered, the system oil port can communicate with the oil inlet of the auxiliary storage motor through the electromagnetic directional valve, the rod cavity of the auxiliary injection oil cylinder can communicate with the oil tank through the electromagnetic directional valve, and the reset spring can drive the auxiliary screw rod to perform a shot return action through the piston rod.

[0008] According to the hydraulic control circuit of the auxiliary injection unit of the dual-color injection molding machine, the auxiliary injection oil cylinder is further provided with a piston, one end of the piston rod is connected with the piston, one end of the reset spring is connected with the piston, and the other end of the reset spring is connected with the inner wall of the auxiliary injection oil cylinder.

[0009] According to the hydraulic control circuit of the auxiliary injection unit of the dual-color injection molding machine, the other end of the piston rod away from the piston can extend to the outside of the auxiliary injection oil cylinder, and the auxiliary screw rod is located below the auxiliary injection oil cylinder and can be connected with the other end of the piston rod away from the piston.

[0010] According to the hydraulic control circuit of the auxiliary injection unit of the dual-color injection molding machine, the auxiliary injection unit further includes an auxiliary barrel and an auxiliary hopper, the other end of the auxiliary screw rod away from the piston rod can extend into the auxiliary barrel, and the auxiliary hopper is located directly above the auxiliary barrel and communicates with the auxiliary barrel.

[0011] According to the hydraulic control circuit of the auxiliary injection unit of the dual-color injection molding machine, the outer wall of the auxiliary injection oil cylinder is provided with a gas permeable hole for communicating the rodless cavity of the auxiliary injection oil cylinder.

[0012] According to the hydraulic control circuit of the auxiliary injection unit of the dual-color injection molding machine, the electromagnetic directional valve is provided with a first oil inlet, a first variable oil port, a second variable oil port and a first oil return port, the first oil inlet communicates with the system oil port, the first variable oil port communicates with the rod cavity of the auxiliary injection oil cylinder, the second variable oil port communicates with the oil inlet of the auxiliary storage motor, and the first oil return port communicates with the oil tank.

[0013] The first oil inlet can communicate with the first variable oil port or the second variable oil port. When the first oil inlet communicates with the second variable oil port, the first variable oil port communicates with the first oil return port.

[0014] The hydraulic control circuit of the sub-injection unit of the double-color injection molding machine has the following beneficial effects.

[0015] The hydraulic control circuit of the sub-injection unit of the double-color injection molding machine further comprises a pressure reducing valve, which is arranged between the system oil port and the first oil inlet port, the oil inlet port of the pressure reducing valve is communicated with the system oil port, and the oil outlet port of the pressure reducing valve is communicated with the first oil inlet port.

[0016] The hydraulic control circuit of the sub-injection unit of the double-color injection molding machine further comprises a pressure table, which is arranged on one side of the pressure reducing valve and is used for detecting the oil pressure after the pressure reducing valve.

[0017] The hydraulic control circuit of the sub-injection unit of the double-color injection molding machine further comprises at least two throttle valves, one of which is arranged between the first variable oil port and the rod cavity of the sub-injection cylinder, and the other is arranged between the second variable oil port and the sub-accumulator motor.

[0018] The utility model has the following beneficial effects:

[0019] 1、Through the spring type design in the sub-injection cylinder, the self-resetting of the piston rod can be realized, and the rod cavity can be communicated with the outside air, so that when hydraulic oil is introduced into the rod cavity, the piston rod moves to the side of the rod cavity, and drives the screw rod to perform the injection action, the reset spring is stretched in this process, so that when the oil in the rod cavity is discharged, the elastic force provided by the reset spring can drive the piston rod to reset, and then drive the screw rod to perform the ejection action, which can simplify the injection hydraulic oil circuit, and then realize the sharing of a set of power system and save the cost.

[0020] 2、An electromagnetic directional valve can control the injection, ejection and storage actions of the sub-injection unit, the number of valves required is less, the cost can be saved, and the occupied space is reduced.

[0021] 3、A pressure reducing valve is arranged between the system oil port and the electromagnetic directional valve, and a throttle valve is arranged between the electromagnetic directional valve and the sub-injection cylinder and the sub-accumulator motor, the pressure limiting protection effect of the injection pressure of the rod cavity of the sub-injection cylinder and the storage pressure of the sub-accumulator motor can be realized through the pressure reducing valve, the flow limiting protection effect of the sub-injection cylinder and the sub-accumulator motor can be realized through the throttle valve, and the safety performance is good. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is the overall oil circuit schematic diagram of the hydraulic control circuit of the embodiment.

[0023] Fig.:

[0024] 1, vice screw; 2, vice injection cylinder; 21, reset spring; 22, piston rod; 3, system oil port; 4, oil tank; 5, electromagnetic directional valve; 51, first electromagnet; 52, second electromagnet; 6, vice storage motor; 7, pressure reducing valve; 8, throttle valve; 9, pressure gauge; 10, vice hopper. DETAILED DESCRIPTION

[0025] The following is a specific embodiment of the utility model and further describes the technical scheme of the utility model in combination with the drawings, but the utility model is not limited to these embodiments.

[0026] As Figure 1 shown, a hydraulic control circuit of a vice injection unit of a double-color injection molding machine, comprising a vice injection cylinder 2, a system oil port 3, an oil tank 4, an electromagnetic directional valve 5 and a vice storage motor 6.

[0027] Among them, the vice injection unit includes a vice screw 1, a vice barrel and a vice hopper 10, one end of the vice screw 1 is connected with one end of a piston rod 22 of the vice injection cylinder 2, the end of the vice screw 1 away from the piston rod 22 can be extended into the vice barrel, the vice hopper 10 is located directly above the vice barrel and communicates with the vice barrel, in this embodiment, the rod cavity of the vice injection cylinder 2 is located on the right side of the rodless cavity, the nozzle of the vice barrel is located at the left end of the vice barrel, first, the vice barrel is fed through the vice hopper 10, when hydraulic oil is added to the rod cavity of the vice injection cylinder 2, it can drive the piston rod 22 to move left, and then drive the vice screw 1 to move left, the vice screw 1 drives the liquid material in the vice barrel to be injected from the nozzle, realizing the injection action of the vice screw 1, when the piston rod 22 moves right, it can drive the vice screw 1 to move right, realizing the ejection action of the vice screw 1.

[0028] Among them, the injection action of the vice screw 1 refers to the movement of the vice screw 1 to the end close to the nozzle, the liquid plastic in the vice barrel is injected from the nozzle into the cavity of the mold and is formed in the cavity, while the ejection action of the vice screw 1 refers to the movement of the vice screw 1 to the end away from the nozzle, leaving the vice barrel empty for the vice hopper 10 to feed.

[0029] Specifically, the end of the piston rod 22 of the sub-injection oil cylinder 2 extending outside the sub-injection oil cylinder 2 is connected with the sub-screw 1, the system oil port 3 can be communicated with the rod cavity of the sub-injection oil cylinder 2 or with the oil inlet of the sub-accumulator motor 6 through the electromagnetic directional valve 5, the oil outlet of the sub-accumulator motor 6 is communicated with the oil tank 4, and the reset spring 21 is arranged in the rod cavity of the sub-injection oil cylinder 2, the reset spring 21 is sleeved outside the piston rod 22 and is used for driving the piston rod 22 to perform a reset action, the first electromagnet 51 and the second electromagnet 52 are arranged on the electromagnetic directional valve 5, when the first electromagnet 51 is powered, the system oil port 3 can be communicated with the rod cavity of the sub-injection oil cylinder 2 through the electromagnetic directional valve 5, when the system oil port 3 supplies oil to the rod cavity of the sub-injection oil cylinder 2, the piston rod 22 can be driven to move to the side of the rodless cavity, that is, to move to the left side, and the sub-screw 1 is driven to perform an injection action to the left side through the piston rod 22, in this process, the movement of the piston rod 22 itself can stretch the reset spring 21, and when the second electromagnet 52 is powered, the system oil port 3 can be communicated with the oil inlet of the sub-accumulator motor 6 through the electromagnetic directional valve 5, and the rod cavity of the sub-injection oil cylinder 2 can be communicated with the oil tank 4 through the electromagnetic directional valve 5, that is, when the system oil port 3 provides the hydraulic oil required by the sub-accumulator motor 6 for storage, the hydraulic oil in the rod cavity of the sub-injection oil cylinder 2 can return to the oil tank 4 through the electromagnetic directional valve 5, at this time, due to the existence of the reset spring 21, the elastic force of the reset spring 21 can provide a reset force, so that the piston rod 22 returns to the position before injection, and the sub-screw 1 can be driven to perform a retracting action through the piston rod 22, in the injection and retracting action processes, oil does not need to be supplied to the rodless cavity of the sub-injection oil cylinder 2, so that the oil circuit can be simplified, the system oil port 3 can be shared with the hydraulic control circuit of the main injection unit, the overall occupied volume is small, and the cost is low.

[0030] In the embodiment, in order to ensure the normal movement of the piston rod 22, the air vent hole is arranged on the outer wall of the sub-injection oil cylinder 2, the air vent hole is used for communicating the rodless cavity of the sub-injection oil cylinder 2, that is, when the piston rod 22 moves to the side close to the rodless cavity, the gas in the rodless cavity is discharged through the air vent hole, so that the pressure of the rodless cavity is prevented from being too high and causing the piston rod 22 to not move normally, and when the piston rod 22 moves to the side away from the rodless cavity, the rodless cavity inhales gas through the air vent hole, so as to ensure the balance of the air pressure in the rodless cavity.

[0031] Of course, in the embodiment, the air vent hole is used to realize the balance of the air pressure in the rodless cavity, and various forms such as a gas exchange pipeline and an air vent groove can also be used, as long as they do not exceed the scope of the application.

[0032] Specifically, the auxiliary injection oil cylinder 2 is further provided with a piston, which divides the inner cavity of the auxiliary injection oil cylinder 2 into a rod cavity and a rodless cavity, one end of a piston rod 22 is connected with the piston, one end of a reset spring 21 is connected with the piston, and the other end of the reset spring 21 is connected with the inner wall of the auxiliary injection oil cylinder 2. When hydraulic oil is supplied to the rod cavity of the auxiliary injection oil cylinder 2, the hydraulic oil can drive the piston to move to the rodless cavity side, in the process, the piston drives the piston rod 22 and one end of the reset spring 21 to move to the rodless cavity side, thereby stretching the reset spring 21 during the injection action.

[0033] In the embodiment, the piston rod 22 and the auxiliary screw 1 are integrally in a U shape, one end of the piston rod 22 away from the piston can extend to the outside of the auxiliary injection oil cylinder 2, and the auxiliary screw 1 is located below the auxiliary injection oil cylinder 2, one end of the auxiliary screw 1 is connected with the one end of the piston rod 22 away from the piston through a connecting rod, which can ensure that when the piston rod 22 drives the auxiliary screw 1 to move to the left, the auxiliary screw 1 can be driven to perform the injection action.

[0034] In order to supply different components with oil through the system oil port 3, the electromagnetic directional valve 5 is provided with a first oil inlet, a first variable oil port, a second variable oil port and a first oil return port, the first oil inlet is communicated with the system oil port 3, the first variable oil port is communicated with the rod cavity of the auxiliary injection oil cylinder 2, the second variable oil port is communicated with the oil inlet of the auxiliary storage motor 6, and the first oil return port is communicated with the oil tank 4. The first oil inlet can be communicated with the first variable oil port or the second variable oil port, when the first oil inlet is communicated with the first variable oil port, the system oil port 3 can supply the rod cavity of the auxiliary injection oil cylinder 2 with oil through the communication oil passage between the first oil inlet and the first variable oil port, thereby driving the auxiliary screw 1 to perform the injection action, when the first oil inlet is communicated with the second variable oil port, the system oil port 3 can supply the auxiliary storage motor 6 with oil through the communication oil passage between the first oil inlet and the second variable oil port, thereby realizing the storage action of the auxiliary injection unit, in the process, the first variable oil port is communicated with the first oil return port, that is, the hydraulic oil in the rod cavity of the auxiliary injection oil cylinder 2 can return to the oil tank 4 through the communication oil passage between the first variable oil port and the first oil return port, thereby realizing the ejection action of the auxiliary screw 1. Since the power for the ejection action of the auxiliary screw 1 is provided by the reset spring 21, it is not necessary to additionally supply hydraulic oil, and the oil passage can be simplified.

[0035] In the embodiment, whether the first electromagnet 51 and the second electromagnet 52 are powered on or not is used to control whether the oil ports of the electromagnetic directional valve 5 are communicated or not, when the first electromagnet 51 is powered on, the first oil inlet is communicated with the first variable oil port, when the second electromagnet 52 is powered on, the first oil inlet is communicated with the second variable oil port, the first variable oil port is communicated with the first oil return port, and when the first electromagnet 51 and the second electromagnet 52 are both powered off, the auxiliary injection unit stops the injection, ejection and storage actions, and does not perform any action.

[0036] In order to realize the pressure limiting protection of the injection pressure of the auxiliary injection oil cylinder 2 and the pressure limiting protection of the storage pressure of the storage motor, a pressure reducing valve 7 is arranged between the system oil port 3 and the first oil inlet, the oil inlet of the pressure reducing valve 7 is communicated with the system oil port 3, the oil outlet of the pressure reducing valve 7 is communicated with the first oil inlet, the hydraulic oil provided by the system oil port 3 needs to pass through the pressure reducing valve 7 to reduce the pressure before flowing to the first oil inlet of the electromagnetic directional valve 5, the pressure of the hydraulic oil provided by the system oil port 3 can be reduced by the pressure reducing valve 7, so that the hydraulic oil pressure entering the rod cavity of the auxiliary injection oil cylinder 2 and the auxiliary storage motor 6 is within a certain pressure range, thereby playing a pressure limiting protection role, wherein the pressure gauge 9 is arranged on one side of the pressure reducing valve 7 and is used for detecting the oil pressure after passing through the pressure reducing valve 7, and the detected pressure can be fed back to the control system, so that the control system judges whether the safety threshold is met, if not, the control system can adjust the pressure reducing range of the pressure reducing valve 7, thereby adjusting the oil pressure entering the auxiliary injection oil cylinder 2 and the auxiliary storage motor 6 until the safety threshold range is met.

[0037] In order to realize the flow limiting protection of the rod cavity of the auxiliary injection oil cylinder 2 and the flow limiting protection of the auxiliary storage motor 6, at least two throttle valves 8 are arranged, one of the throttle valves 8 is arranged between the first variable oil port and the rod cavity of the auxiliary injection oil cylinder 2, and the other of the throttle valves 8 is arranged between the second variable oil port and the auxiliary storage motor 6, that is, the hydraulic oil discharged by the electromagnetic directional valve 5 needs to pass through the throttle valve 8 before entering the auxiliary storage motor 6 and the auxiliary injection oil cylinder 2, so that the hydraulic oil flow can be limited by the throttle valve 8, and the injection speed and the storage speed can be controlled by the throttle valve 8.

[0038] The technical scheme of the utility model is described in detail above in combination with the drawings, and the described embodiments are used to help understand the idea of the utility model. The specific embodiments described in this paper are only examples of the spirit of the utility model. Those skilled in the art of the utility model can make various modifications or supplements to the described specific embodiments or replace them with similar ways, but will not deviate from the spirit of the utility model or exceed the scope defined by the appended claims.

[0039] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the utility model are only used to explain the relative position relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings), if the specific posture changes, the directional indications will also change accordingly.

[0040] In addition, the descriptions such as "first", "second", "one" and the like in the present application are only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0041] In the present application, unless otherwise specifically defined and limited, the terms "connection", "fixing" and the like should be broadly understood, for example, "fixing" can be fixed connection, or detachable connection, or integrated; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium, can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0042] In addition, the technical solutions of each embodiment of the present application can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, also not within the protection scope required by the present application.

Claims

1. A hydraulic control circuit for a secondary injection unit of a two-color injection molding machine, the secondary injection unit comprising a secondary screw, characterized in that, The hydraulic control circuit includes an auxiliary injection cylinder, a system oil port, an oil tank, a solenoid directional valve, and an auxiliary storage motor. One end of the piston rod of the auxiliary injection cylinder is connected to the auxiliary screw. The system oil port can be connected to the rod chamber of the auxiliary injection cylinder or the oil inlet of the auxiliary storage motor through the solenoid directional valve. The oil outlet of the auxiliary storage motor is connected to the oil tank. The auxiliary injection cylinder has a return spring in its rod chamber. The return spring is sleeved on the outside of the piston rod and is used to drive the piston rod to return to its original position. The electromagnetic directional valve is equipped with a first electromagnet and a second electromagnet. When the first electromagnet is energized, the system oil port can be connected to the rod chamber of the auxiliary injection cylinder through the electromagnetic directional valve, and the piston rod can drive the auxiliary screw to perform an injection action and stretch the return spring. When the second electromagnet is energized, the system oil port can be connected to the oil inlet of the auxiliary storage motor through the electromagnetic directional valve, and the rod chamber of the auxiliary injection cylinder can be connected to the oil tank through the electromagnetic directional valve, and the return spring can drive the auxiliary screw to perform an injection retraction action through the piston rod.

2. The hydraulic control circuit of the auxiliary injection unit of a two-color injection molding machine according to claim 1, characterized in that, The auxiliary injection cylinder is also equipped with a piston. One end of the piston rod is connected to the piston, one end of the return spring is connected to the piston, and the other end of the return spring is connected to the inner wall of the auxiliary injection cylinder.

3. The hydraulic control circuit of the auxiliary injection unit of a two-color injection molding machine according to claim 2, characterized in that, The end of the piston rod away from the piston can extend to the outside of the auxiliary injection cylinder. The auxiliary screw is located below the auxiliary injection cylinder and can be connected to the end of the piston rod away from the piston.

4. The hydraulic control circuit of the auxiliary injection unit of a two-color injection molding machine according to claim 3, characterized in that, The auxiliary injection unit also includes an auxiliary material cylinder and an auxiliary material hopper. The end of the auxiliary screw away from the piston rod can extend into the auxiliary material cylinder. The auxiliary material hopper is located directly above the auxiliary material cylinder and is in communication with the auxiliary material cylinder.

5. The hydraulic control circuit of the auxiliary injection unit of a two-color injection molding machine according to claim 1 or 3, characterized in that, The outer wall of the auxiliary injection cylinder is provided with a vent hole, which is used to connect to the rodless chamber of the auxiliary injection cylinder.

6. The hydraulic control circuit of the auxiliary injection unit of a two-color injection molding machine according to claim 1, characterized in that, The electromagnetic directional valve is provided with a first oil inlet, a first variable oil inlet, a second variable oil inlet, and a first oil return port. The first oil inlet is connected to the system oil inlet, the first variable oil inlet is connected to the rod chamber of the auxiliary injection cylinder, the second variable oil inlet is connected to the oil inlet of the auxiliary storage motor, and the first oil return port is connected to the oil tank. The first oil inlet can be connected to either the first variable oil port or the second variable oil port. When the first oil inlet is connected to the second variable oil port, the first variable oil port is connected to the first return oil port.

7. The hydraulic control circuit of the auxiliary injection unit of a two-color injection molding machine according to claim 6, characterized in that, When the first electromagnet is energized, the first oil inlet is connected to the first variable oil port; when the second electromagnet is energized, the first oil inlet is connected to the second variable oil port; and the first variable oil port is connected to the first return oil port.

8. The hydraulic control circuit of the auxiliary injection unit of a two-color injection molding machine according to claim 6, characterized in that, It also includes a pressure reducing valve, which is located between the system oil port and the first oil inlet. The oil inlet of the pressure reducing valve is connected to the system oil port, and the oil outlet of the pressure reducing valve is connected to the first oil inlet.

9. The hydraulic control circuit of the auxiliary injection unit of a two-color injection molding machine according to claim 8, characterized in that, It also includes a pressure gauge located on one side of the pressure reducing valve and used to detect the oil pressure after passing through the pressure reducing valve.

10. The hydraulic control circuit of the auxiliary injection unit of a two-color injection molding machine according to claim 6, characterized in that, It also includes at least two throttle valves, one of which is located between the first variable oil port and the rod chamber of the auxiliary injection cylinder, and the other of which is located between the second variable oil port and the auxiliary storage motor.

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