Oil way for nozzle to store low-viscosity sizing material

Abstract

The utility model discloses an oil way for a nozzle to store low-viscosity sizing material, which comprises a hydraulic cylinder, a hydraulic motor for driving a screw rod to rotate, a three-position four-way valve, a two-position four-way valve, an oil inlet and an oil outlet, the hydraulic cylinder comprises a piston rod connected with the screw rod, and the oil outlet is provided with a one-way valve; the first position of the two-position four-way valve is that an oil inlet is communicated with an oil inlet hole of the hydraulic motor, and a rod cavity of the hydraulic cylinder is communicated with an oil outlet; the first position of the three-position four-way valve is that an oil outlet hole of the hydraulic motor is communicated with a rodless cavity of the hydraulic cylinder. When the two-position four-way valve and the three-position four-way valve are both located at the first position, the hydraulic motor supplies oil to the rodless cavity of the hydraulic cylinder, the oil way drives the screw to rotate to convey low-viscosity sizing materials to the nozzle at the same time, meanwhile, the screw is made to retreat, a gap is automatically generated between the nozzle and the screw, and therefore the low-viscosity sizing materials are stored in the gap; and the condition that the low-viscosity sizing material conveyed to the nozzle by the screw rod is directly ejected from the nozzle opening is avoided.

Description

Technical Field

[0001] The utility model relates to the field of injection molding equipment, in particular to an oil circuit for storing low-viscosity rubber materials in a nozzle. Background Art

[0002] With the development of industrial technology, the application fields of plastic products are becoming wider and wider, and the types of plastics used in injection molding machines are also increasing. The injection molding machine includes a barrel, a nozzle is provided at the front end of the barrel, and a screw is provided in the barrel for conveying rubber to the nozzle.

[0003] For example, a Chinese patent with announcement number CN220841211U discloses a sealing and anti-return structure for an injection molding machine. When the screw rotates, the molten rubber flows along the gap between the barrel and the screw to the rear end of the nozzle. At the same time, the more rubber is stored at the rear end of the nozzle, the more pressure will be generated to make the screw retreat, so that a gap for storing rubber is automatically generated between the nozzle and the screw. In the actual production process, it is found that when the screw conveys rubber with lower viscosity, the pressure generated by the rubber is lower and the screw cannot retreat, resulting in a smaller gap between the nozzle and the screw. The rubber with lower viscosity is difficult to store between the nozzle and the screw, and the excess rubber will flow directly out of the nozzle. In view of this, the utility model proposes an oil circuit for storing low-viscosity rubber in the nozzle to solve the above problem. Utility Model Content

[0004] The utility model overcomes the shortcomings of the above-mentioned technology and provides an oil circuit for storing low-viscosity rubber materials in a nozzle.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An oil circuit for storing low-viscosity rubber in a nozzle, used to drive a screw to rotate or / and move forward and backward around its central axis. The oil circuit includes a hydraulic cylinder, a hydraulic motor for driving the screw to rotate, a three-position four-way valve, a two-position four-way valve, an oil inlet, and an oil outlet. The hydraulic cylinder includes a piston rod for connecting to the screw drive, a metering pump is provided at the oil inlet, and a one-way valve is provided at the oil outlet. The four interfaces of the two-position four-way valve are respectively connected to the oil inlet, the oil inlet hole of the hydraulic motor, the rod cavity of the hydraulic cylinder, and the oil outlet; the four interfaces of the three-position four-way valve are respectively connected to the oil outlet hole of the hydraulic motor, the rodless cavity of the hydraulic cylinder, the oil inlet, and the rod cavity of the hydraulic cylinder; the first position of the two-position four-way valve is the oil inlet connected to the oil inlet hole of the hydraulic motor, and the rod cavity of the hydraulic cylinder is connected to the oil outlet; the first position of the three-position four-way valve is the oil outlet hole of the hydraulic motor connected to the rodless cavity of the hydraulic cylinder.

[0007] Preferably, the one-way valve is a spring-loaded one-way valve.

[0008] Preferably, the second position of the three-position four-way valve is that the oil inlet is connected to the rod chamber of the hydraulic cylinder, and the oil outlet is connected to the rodless chamber of the hydraulic cylinder; the second position of the two-position four-way valve is that the oil inlet, the oil inlet hole of the hydraulic motor, the rod chamber of the hydraulic cylinder, and the oil outlet are all cut off. When the two-position four-way valve and the three-position four-way valve are both in the second position, the hydraulic cylinder drives the screw to move forward.

[0009] Preferably, the third position of the three-position four-way valve is such that the oil inlet is connected to the rodless chamber of the hydraulic cylinder, and the oil outlet is connected to the rod chamber of the hydraulic cylinder.

[0010] Preferably, the oil circuit further comprises a flow meter arranged between the oil outlet and the two-position four-way valve.

[0011] Preferably, the metering pump is an electric pump.

[0012] Preferably, the three-position four-way valve comprises an injection coil for switching the three-position four-way valve to the second position and a de-energizing coil for switching the three-position four-way valve to the third position.

[0013] Preferably, the two-position four-way valve comprises a melt coil for switching the two-position four-way valve to the first position.

[0014] When the two-position four-way valve and the three-position four-way valve are both in the first position, the metering pump delivers the hydraulic oil from the oil inlet to the two-position four-way valve, and the hydraulic oil then flows through the hydraulic motor, the three-position four-way valve, and is finally delivered to the rodless chamber of the hydraulic cylinder. The hydraulic oil in the rod chamber of the hydraulic cylinder flows through the two-position four-way valve and the one-way valve and is finally delivered to the oil outlet. Driven by the hydraulic oil, the hydraulic motor drives the screw to rotate and delivers the low-viscosity rubber to the nozzle. At the same time, the piston rod of the hydraulic oil input into the rodless chamber of the hydraulic cylinder drives the screw backward away from the nozzle, so that a gap for storing the rubber is automatically generated between the nozzle and the screw.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] 1. When the two-position four-way valve and the three-position four-way valve of the utility model are both in the first position, the oil circuit simultaneously drives the screw to rotate to deliver the low-viscosity rubber to the nozzle, and at the same time allows the screw to retreat, so that a gap is automatically generated between the nozzle and the screw, so that the low-viscosity rubber is stored in the gap, avoiding the situation where the low-viscosity rubber delivered by the screw to the nozzle is directly ejected from the nozzle.

[0017] 2. The oil outlet is provided with a one-way valve, which is a spring-loaded one-way valve. When the oil circuit drives the screw to deliver low-viscosity rubber to the nozzle, the hydraulic oil of the hydraulic cylinder needs to overcome the resistance of the spring-loaded one-way valve when it flows back to the oil outlet. In addition, the hydraulic oil in the rod chamber of the hydraulic cylinder also needs to flow back to the oil outlet, so that the hydraulic oil in the rodless chamber of the hydraulic cylinder rarely flows back to the oil outlet, and the hydraulic oil input into the rodless chamber of the hydraulic cylinder is used as much as possible to push the piston rod backward. The utility model only controls the flow direction of the hydraulic oil of the hydraulic system through the one-way valve, and further controls the screw to rotate and move backward at the same time. It has a simple structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the oil circuit state when the utility model performs the rubber material conveying action;

[0019] Figure 2 It is a schematic diagram of the oil circuit state when the utility model performs the injection action;

[0020] Figure 3 It is a schematic diagram of the oil circuit state when the utility model performs the ejection and retreat action;

[0021] The implementation, functional features and advantages of the present invention will be further described in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0022] The following examples further illustrate the features of the present invention and other related features to facilitate understanding by those skilled in the art:

[0023] Reference Figure 1-3 , an embodiment of the utility model is proposed for an oil circuit for storing low-viscosity rubber in a nozzle:

[0024] An oil circuit for storing low-viscosity rubber materials at a nozzle comprises a hydraulic cylinder 1, a hydraulic motor 3 for driving a screw rod 2 to rotate, a three-position four-way valve 4, a two-position four-way valve 5, an oil inlet 61, and an oil outlet 62. The hydraulic cylinder 1 comprises a piston rod 11 for drivingly connecting with the screw rod 2, a metering pump 7 is provided at the oil inlet 61, and a one-way valve 8 is provided at the oil outlet 62. Four interfaces of the two-position four-way valve 5 are respectively connected with the oil inlet 61, the oil inlet hole of the hydraulic motor 3, the hydraulic cylinder rod chamber 12, and the oil outlet 62; four interfaces of the three-position four-way valve 4 are respectively connected with the oil outlet hole of the hydraulic motor 3, the hydraulic cylinder rodless chamber 13, the oil inlet 61, and the hydraulic cylinder rod chamber 12; the first position of the two-position four-way valve 5 is that the oil inlet 61 is connected with the oil inlet hole of the hydraulic motor 3, and the hydraulic cylinder rod chamber 12 is connected with the oil outlet 62; the first position of the three-position four-way valve 4 is that the oil outlet hole of the hydraulic motor 3 is connected with the hydraulic cylinder rodless chamber 13.

[0025] In the prior art, when the screw 2 rotates, the molten rubber with a higher viscosity flows to the rear end of the nozzle along the gap between the barrel and the screw 2. At the same time, the more rubber is stored at the rear end of the nozzle, the more pressure is generated to make the screw 2 retreat, so that a gap for storing rubber is automatically generated between the nozzle and the screw 2. When the screw 2 rotates to convey the rubber with a lower viscosity, the pressure generated by the rubber is smaller and the screw 2 cannot retreat, resulting in a smaller gap between the nozzle and the screw 2. The rubber with a lower viscosity is difficult to be stored between the nozzle and the screw 2, and the excess rubber will flow out directly from the nozzle.

[0026] like Figure 1 As shown, the oil circuit of the utility model sets the two-position four-way valve 5 and the three-position four-way valve 4 in the first position, and the metering pump 7 delivers the hydraulic oil from the oil inlet 61 to the two-position four-way valve 5, and the hydraulic oil then flows through the hydraulic motor 3, the three-position four-way valve 4 in sequence, and is finally delivered to the rodless chamber 13 of the hydraulic cylinder; and the hydraulic oil in the rod chamber 12 of the hydraulic cylinder flows through the two-position four-way valve 5, the one-way valve 8 in sequence, and is finally delivered to the oil outlet 62. Driven by the hydraulic oil, the hydraulic motor 3 drives the screw 2 to rotate, and delivers the low-viscosity rubber to the nozzle (not shown in the drawings), and at the same time, the piston rod 11 drives the screw 2 backward away from the nozzle, so that a gap for storing the rubber is automatically generated between the nozzle and the screw 2, thereby preventing the low-viscosity rubber delivered to the nozzle by the screw 2 from being directly ejected from the nozzle.

[0027] like Figure 1 As shown, the one-way valve 8 is a spring-type one-way valve. When the oil circuit drives the screw 2 to deliver low-viscosity rubber to the nozzle, the hydraulic oil of the hydraulic cylinder 1 needs to overcome the resistance of the spring-type one-way valve 8 to return to the oil outlet 62. In addition, the hydraulic oil in the rod chamber 12 of the hydraulic cylinder also needs to return to the oil outlet 62, so that the hydraulic oil in the rodless chamber 13 of the hydraulic cylinder rarely returns to the oil outlet 62, and the hydraulic oil input into the rodless chamber 13 of the hydraulic cylinder is used as much as possible to push the piston rod 11 backward. However, if too much hydraulic oil is input into the rodless chamber 13 of the hydraulic cylinder, the excess hydraulic oil will also flow back from the one-way valve 8 to the oil outlet 62, avoiding the problem of too fast retreat speed due to too much hydraulic oil input into the rodless chamber 13 of the hydraulic cylinder.

[0028] The utility model controls the flow direction of the hydraulic oil only through the one-way valve 8, and further controls the rotation and retreat movement of the screw 2 at the same time, and has a simple structure; and compared with setting up an additional quantitative pump to deliver hydraulic oil to the rodless chamber 13 of the hydraulic cylinder, the utility model has lower costs.

[0029] The second position of the three-position four-way valve 4 is that the oil inlet 61 is connected to the hydraulic cylinder rod chamber 12, and the oil outlet 62 is connected to the hydraulic cylinder rodless chamber 13; the second position of the two-position four-way valve 5 is that the oil inlet 61, the oil inlet hole of the hydraulic motor 3, the hydraulic cylinder rod chamber 12, and the oil outlet 62 are all blocked. Figure 2As shown, when the two-position four-way valve 5 and the three-position four-way valve 4 are both in the second position, the hydraulic cylinder 1 drives the screw 2 to move forward and drives the nozzle to inject glue, and the hydraulic motor 3 does not work during this process.

[0030] The third position of the three-position four-way valve 4 is that the oil inlet 61 is connected to the hydraulic cylinder rodless chamber 13, and the oil outlet 62 is connected to the hydraulic cylinder rod chamber 12. When the nozzle completes the injection process, Figure 3 As shown, the three-position four-way valve 4 is switched to the third position, and the two-position four-way valve 5 is in the second position, so that the hydraulic cylinder 1 drives the screw rod 2 to move backward, and the hydraulic motor 3 does not work during this process.

[0031] Specifically, the oil circuit also includes a flow meter 9 disposed between the oil outlet 62 and the two-position four-way valve 5 for monitoring the oil volume in the oil circuit. The quantitative pump 7 is an electric pump for controlling the input volume of the hydraulic oil in the oil circuit.

[0032] like Figure 1 As shown, the three-position four-way valve 4 includes a glue injection coil 41 for switching the three-position four-way valve 4 to the second position and a wire withdrawal coil 42 for switching the three-position four-way valve 4 to the third position. The first position of the three-position four-way valve 4 is the normal position. The two-position four-way valve 5 includes a glue melting coil 51 for switching the two-position four-way valve 5 to the first position, and the second position of the two-position four-way valve 5 is the normal position.

[0033] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structural transformation made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, is also included in the patent protection scope of the present invention.

Claims

1. An oil circuit for storing low-viscosity rubber in a nozzle, used to drive a screw (2) to rotate or / and move forward and backward around its central axis, characterized in that: The invention comprises a hydraulic cylinder (1), a hydraulic motor (3) for driving a screw rod (2) to rotate, a three-position four-way valve (4), a two-position four-way valve (5), an oil inlet (61), and an oil outlet (62); the hydraulic cylinder (1) comprises a piston rod (11) for drivingly connecting with the screw rod (2); the oil inlet (61) is provided with a metering pump (7); the oil outlet (62) is provided with a one-way valve (8); four interfaces of the two-position four-way valve (5) are respectively connected with the oil inlet (61), the oil inlet hole of the hydraulic motor (3), the rod cavity (12) of the hydraulic cylinder, and the oil outlet (62); the four interfaces of the three-position four-way valve (4) are respectively connected with the oil inlet (61), the oil inlet hole of the hydraulic motor (3), the rod cavity (12) of the hydraulic cylinder, and the oil outlet (62); They are respectively connected to the oil outlet hole of the hydraulic motor (3), the rodless chamber (13) of the hydraulic cylinder, the oil inlet (61), and the rod chamber (12) of the hydraulic cylinder; the first position of the two-position four-way valve (5) is the oil inlet (61) communicating with the oil outlet hole of the hydraulic motor (3), and the rod chamber (12) of the hydraulic cylinder is communicating with the oil outlet (62); the first position of the three-position four-way valve (4) is the oil outlet hole of the hydraulic motor (3) communicating with the rodless chamber (13) of the hydraulic cylinder; when the two-position four-way valve (5) and the three-position four-way valve (4) are both in the first position, the screw (2) rotates to transport the low-viscosity rubber material to the nozzle, and the screw (2) moves backward away from the nozzle.

2. The oil circuit for storing low-viscosity rubber in a nozzle according to claim 1, characterized in that: The one-way valve (8) is a spring-type one-way valve.

3. The oil circuit for storing low-viscosity rubber in a nozzle according to claim 1, characterized in that: The second position of the three-position four-way valve (4) is an oil inlet (61) connected to the hydraulic cylinder rod chamber (12), and the oil outlet (62) is connected to the hydraulic cylinder rodless chamber (13); the second position of the two-position four-way valve (5) is an oil inlet (61), an oil inlet hole of the hydraulic motor (3), a hydraulic cylinder rod chamber (12), and an oil outlet (62), all of which are blocked; when the two-position four-way valve (5) and the three-position four-way valve (4) are both in the second position, the hydraulic cylinder (1) drives the screw (2) to move forward.

4. The oil circuit for storing low-viscosity rubber in a nozzle according to claim 1, characterized in that: The third position of the three-position four-way valve (4) is an oil inlet (61) communicating with the rodless chamber (13) of the hydraulic cylinder, and an oil outlet (62) communicating with the rod chamber (12) of the hydraulic cylinder.

5. The oil circuit for storing low-viscosity rubber in a nozzle according to claim 1, characterized in that: It comprises a flow meter (9) arranged between an oil outlet (62) and a two-position four-way valve (5).

6. The oil circuit for storing low-viscosity rubber in a nozzle according to claim 1, characterized in that: The metering pump (7) is an electric pump.

7. The oil circuit for storing low-viscosity rubber in a nozzle according to claim 3, characterized in that: The three-position four-way valve (4) comprises an injection coil (41) for switching the three-position four-way valve (4) to a second position, and a withdrawal coil (42) for switching the three-position four-way valve (4) to a third position.

8. The oil circuit for storing low-viscosity rubber in a nozzle according to claim 1, characterized in that: The two-position four-way valve (5) comprises a melt coil (51) used for switching the two-position four-way valve (5) to a first position.

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