Hydraulic cylinder high-speed oil supplement system and injection molding machine

Abstract

The application discloses a hydraulic oil cylinder high-speed oil supplement system and an injection molding machine, and belongs to the technical field of hydraulic systems of injection molding machines, which comprises an oil cylinder, a control oil circuit, an oil supply circuit and an oil tank, the control oil circuit is communicated with the oil cylinder, one end of the oil supply circuit is communicated with the control oil circuit, and the other end is communicated with the oil tank, the control oil circuit comprises a first plug-in valve, a second plug-in valve, a third plug-in valve, a fourth plug-in valve, a first electromagnetic valve, a second electromagnetic valve and a third electromagnetic valve, one end of the first plug-in valve is communicated with a rodless cavity of the oil cylinder, and the other end is communicated with the oil tank, one end of the second plug-in valve is communicated with the rodless cavity of the oil cylinder, and the other end is connected with the oil supply circuit, the first electromagnetic valve controls the opening and closing of the first plug-in valve and the second plug-in valve, the first plug-in valve and the second plug-in valve are asynchronously operated, one end of the third plug-in valve is communicated with a rod cavity of the oil cylinder, and the other end is connected with the oil supply circuit, one end of the fourth plug-in valve is communicated with the rod cavity of the oil cylinder, and the other end is connected with the oil tank, the second electromagnetic valve controls the opening and closing of the third plug-in valve, the third electromagnetic valve controls the opening and closing of the fourth plug-in valve, the third plug-in valve and the fourth plug-in valve are asynchronously operated, the four plug-in valves are combined to control the oil inlet and oil return of the oil cylinder, the length of the moving distance of the hydraulic oil is shortened, the resistance of the hydraulic oil flow is reduced, the action sensitivity of the oil cylinder is improved, and therefore the production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of injection molding machine hydraulic system, and particularly relates to a hydraulic cylinder high-speed oil supplement system and an injection molding machine. BACKGROUND

[0002] The high-speed injection molding machine mainly refers to an injection molding machine with a speed exceeding 300 mm / s, which is mainly used for molding thin-walled plastic products. In order to achieve such a high injection speed, an accumulator is used in the glue injection circuit to increase the glue injection speed. However, the accumulator needs to store energy and has a slow response speed, which cannot meet the requirements of high-speed injection. The existing electric glue injection molding machines using traditional oil circuits generally have a glue melting and relaxation delay problem. The glue is immediately relaxed after melting, and the action is generally performed after 20s-40s. The specific time is determined by the size of the glue injection cylinder and the length of the glue melting stroke, which seriously affects the production efficiency of the machine. In addition, the glue back pressure control of the oil supplement circuit is not accurate, the pressure and flow of the oil supplement hydraulic source are uncontrollable, the glue back pressure is uncontrollable and unstable during relaxation, which affects the quality and efficiency of the machine production and has high energy consumption. In addition, the oil return of the general injection molding machine needs to pass through the cooler and then return to the oil tank. The cooling part will generate a large liquid resistance when sucking oil, and the oil cannot be smoothly sucked into the glue injection cylinder. Therefore, the existing injection molding machine needs a hydraulic system that can quickly respond to the driving of the glue injection rod.

[0003] The patent application with the publication number CN114001059A discloses a V-shaped injection hydraulic oil circuit of an injection molding machine, which comprises a system pressure oil inlet, an oil return port, a seat oil circuit, an injection oil circuit, and a storage oil circuit. A bidirectional hydraulic lock, a first damper, and a second damper are added to the seat oil circuit for driving the injection seat to move, so as to ensure the stability of the upward and downward movement of the injection seat and effectively maintain the position of the injection seat. A third electromagnetic reversing valve is arranged in the storage oil circuit for supplementing oil for the injection cylinder, and a one-way valve is arranged between the storage oil circuit and the oil return port. The one-way valve is also located between the injection oil circuit and the oil return port. The one-way valve can provide back pressure for the third electromagnetic reversing valve and the injection cylinder. The resistance of the oil liquid during oil supplement of the hydraulic oil circuit is large, and there is a delay in action. SUMMARY

[0004] One of the purposes of the present application is to provide a hydraulic cylinder high-speed oil supplement system, which solves the problems of large oil supplement resistance and high action delay of the existing hydraulic system.

[0005] To achieve the above-mentioned purposes, the technical solutions adopted by the present application are as follows:

[0006] A hydraulic cylinder high-speed oil supplement system, comprising a cylinder, a control oil circuit, an oil supply circuit and an oil tank, the control oil circuit being communicated with the cylinder, one end of the oil supply circuit being communicated with the control oil circuit and the other end being communicated with the oil tank, the control oil circuit comprising a first cartridge valve, a second cartridge valve, a third cartridge valve, a fourth cartridge valve, a first electromagnetic valve, a second electromagnetic valve and a third electromagnetic valve, one end of the first cartridge valve being communicated with the rodless cavity of the cylinder and the other end being communicated with the oil tank, one end of the second cartridge valve being communicated with the rodless cavity of the cylinder and the other end being connected with the oil supply circuit, the first electromagnetic valve controlling the opening and closing of the first cartridge valve and the second cartridge valve, the first cartridge valve and the second cartridge valve acting asynchronously, one end of the third cartridge valve being communicated with the rod cavity of the cylinder and the other end being connected with the oil supply circuit, one end of the fourth cartridge valve being communicated with the rod cavity of the cylinder and the other end being connected with the oil tank, the second electromagnetic valve controlling the opening and closing of the third cartridge valve, the third electromagnetic valve controlling the opening and closing of the fourth cartridge valve, the third cartridge valve and the fourth cartridge valve acting asynchronously, the four cartridge valves directly controlling the oil inlet and oil return of the cylinder, shortening the length of the hydraulic oil moving distance and reducing the resistance of the hydraulic oil flow, the action sensitivity of the cylinder being improved, thereby improving the production efficiency.

[0007] Further, the control oil circuit further comprises a pilot relief valve and a proportional relief valve, one end of the pilot relief valve being connected with the third electromagnetic valve and the other end being connected with one end of the proportional relief valve, the other end of the proportional relief valve being connected with the oil tank, for setting the pressure of the relief oil return.

[0008] As preferred, the first electromagnetic valve and the second electromagnetic valve are two-position two-way valves for oil reversing, the third electromagnetic valve is a two-position three-way valve for oil reversing and stopping, the first electromagnetic valve remotely controls the on-off of the first cartridge valve for controlling the opening and closing of the cartridge valve to realize oil inlet and oil return.

[0009] Further, the control oil circuit further comprises a reversing electromagnetic valve, one end of the reversing electromagnetic valve being connected with the second electromagnetic valve and the other end being connected with the oil tank, for pressure relief of the injection.

[0010] Further, the oil supply circuit comprises a first oil pump, a first servo controller, a second oil pump and a second servo controller, one end of the first oil pump being connected with the oil tank and the other end being connected with the control oil circuit, the first servo controller controlling the opening and closing of the first oil pump, one end of the second oil pump being connected with the oil tank and the other end being connected with the control oil circuit, the second servo controller being used for controlling the opening and closing of the second oil pump, for providing sufficient hydraulic oil to the cylinder.

[0011] As preferred, the first oil pump and the second oil pump are duplex pumps, and the first oil pump and the second oil pump are connected in parallel to prevent insufficient oil amount and insufficient oil pressure.

[0012] Further, the cooling system is further included, which is communicated with the first oil pump and the second oil pump, and the hydraulic oil is not returned through the cooling system, and the hydraulic oil is circulated between the cooling system and the oil tank to complete cooling.

[0013] Further, the cooling system includes a filter, a cooler and a third oil pump, one end of the filter is communicated with the oil supply circuit, the other end is connected with one end of the cooler, the other end of the cooler is connected with one end of the third oil pump, and the other end of the third oil pump is communicated with the oil tank, for filtering and cooling the hydraulic oil.

[0014] As preferred, the cooling system further includes a cooling check valve, one end of the cooling check valve is communicated with the oil supply circuit, the other end of the cooling check valve is communicated with the oil tank, the cooling check valve is connected with the cooler in parallel to form a return branch, for shunting use when cooling the hydraulic oil.

[0015] The second object of the present application is to provide an injection molding machine, which solves the problem of low production efficiency caused by the control delay of the existing injection molding machine.

[0016] To achieve the above-mentioned objects, the technical solutions adopted by the present application are as follows:

[0017] An injection molding machine includes a hydraulic cylinder high-speed oil supplement system and a plastic injection screw, the hydraulic cylinder high-speed oil supplement system provides power for the action of the plastic injection screw, and can quickly act when retracting, thereby improving production efficiency.

[0018] The present application has the following advantages:

[0019] (1) The control oil circuit on the hydraulic cylinder high-speed oil supplement system includes a plurality of plug-in valves of on-off oil circuits and a plurality of electromagnetic valves for switching the state of the control oil circuit, when the cylinder is retracting, the rod cavity is supplied with oil by the oil supply circuit, and the rodless cavity is communicated with the oil tank through the first plug-in valve, so that the rodless cavity can quickly suck oil from the oil tank under negative pressure, the first plug-in valve is sensitive in action, and the resistance of the oil entering the rodless cavity is small, when the cylinder is advancing, the rod cavity is controlled by the fourth plug-in valve to discharge oil, the fourth plug-in valve is sensitive in action, and the resistance of the oil discharged from the rod cavity to the oil tank is small, thereby improving the sensitivity of the cylinder action and reducing the impact of the cylinder action.

[0020] (2) The control oil circuit on the hydraulic cylinder high-speed oil supplement system is provided with a pilot relief valve and a proportional relief valve group discharge oil circuit, which can accurately control the discharge pressure and flow; a servo controller is used to control the oil supply circuit composed of two groups of oil pumps in parallel, and the redundant composition can ensure the stability of the oil inlet pressure and flow; in addition, an independent cooling system is provided, which is connected with the oil supply circuit, and the pumped oil can be directly cooled and filtered, and the oil cylinder does not pass through the cooling system when returning oil, which reduces the length of the oil return path and the resistance of the oil return, and further improves the sensitivity of the oil cylinder action. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The hydraulic cylinder high-speed oil supplement system provided by the present application is shown in the figure.

[0022] Reference signs:

[0023] 1, injection rubber screw; 11, motor; 2, oil cylinder; 3, control oil circuit; 31, first cartridge valve; 32, second cartridge valve; 33, first electromagnetic valve; 34, second electromagnetic valve; 35, third cartridge valve; 36, third electromagnetic valve; 37, fourth cartridge valve; 38, pilot relief valve; 381, proportional relief valve; 39, reversing electromagnetic valve; 4, oil supply circuit; 41, first oil pump; 42, first servo controller; 43, second oil pump; 44, second servo controller; 5, cooling system; 51, cooler; 52, third oil pump; 53, filter; 54, cooling check valve; 6, oil tank. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0025] Embodiment one

[0026] As Figure 1As shown, the embodiment discloses a hydraulic cylinder high-speed oil supplement system, which comprises a cylinder 2, a control oil circuit 3, an oil supply circuit 4 and an oil tank 6, the control oil circuit 3 is communicated with the cylinder 2, one end of the oil supply circuit 4 is communicated with the control oil circuit 3, and the other end is communicated with the oil tank 6, the control oil circuit 3 comprises a first cartridge valve 31, a second cartridge valve 32, a third cartridge valve 35, a fourth cartridge valve 37, a first electromagnetic valve 33, a second electromagnetic valve 34 and a third electromagnetic valve 36, one end of the first cartridge valve 31 is communicated with a rodless cavity of the cylinder 2, and the other end is communicated with the oil tank 6, one end of the second cartridge valve 32 is communicated with the rodless cavity of the cylinder 2, and the other end is connected with the oil supply circuit 4, the first electromagnetic valve 33 controls opening and closing of the first cartridge valve 31 and the second cartridge valve 32, the first cartridge valve 31 and the second cartridge valve 32 act asynchronously, one end of the third cartridge valve 35 is communicated with a rod cavity of the cylinder 2, and the other end is connected with the oil supply circuit 4, one end of the fourth cartridge valve 37 is communicated with the rod cavity of the cylinder 2, and the other end is connected with the oil tank 6, the second electromagnetic valve 34 controls opening and closing of the third cartridge valve 35, the third electromagnetic valve 36 controls opening and closing of the fourth cartridge valve 37, the third cartridge valve 35 and the fourth cartridge valve 37 act asynchronously, oil inlet and oil outlet of the cylinder 2 are completed by the first cartridge valve 31, the second cartridge valve 32, the third cartridge valve 35 and the fourth cartridge valve 37 respectively when the cylinder 2 advances and retreats, the back pressure side of the cylinder 2 can suck oil with low resistance, the resistance of hydraulic oil flow is reduced, the sensitivity of the cylinder 2 is improved, and thus the efficiency of the injection glue screw rod 1 is improved.

[0027] The first cartridge valve 31 is a normally open valve, which is used for rodless cavity non-resistance negative pressure oil suction, when the first electromagnetic valve 33 is powered, the first cartridge valve 31 is closed, the second cartridge valve 32 controls oil inlet to the rodless cavity of the cylinder 2, and the cylinder 2 completes the loose retreat action.

[0028] Further, the control oil circuit 3 further comprises a pilot relief valve 38 and a proportional relief valve 381, one end of the pilot relief valve 38 is connected with the third electromagnetic valve 36, the other end is connected with one end of the proportional relief valve 381, the other end of the proportional relief valve 381 is connected with the oil tank 6, adjusting the pilot relief valve 38 and the proportional relief valve 381 can set the opening pressure of the third electromagnetic valve 36, and the third electromagnetic valve 36 controls opening and closing of the fourth cartridge valve 37.

[0029] Preferably, the first electromagnetic valve 33 and the second electromagnetic valve 34 are two-position two-way valves, which are used for oil liquid reversing, specifically, the first electromagnetic valve 33 remotely controls on-off of the first cartridge valve 31 and directly controls opening and closing of the second cartridge valve 32, the second electromagnetic valve 34 controls opening and closing of the third cartridge valve 35, the third electromagnetic valve 36 is a two-position three-way valve, which is used for oil liquid reversing and stopping, specifically, the third electromagnetic valve 36 controls opening and closing of the fourth cartridge valve 37.

[0030] Further, the control oil circuit 3 further comprises a reversing solenoid valve 39, one end of the reversing solenoid valve 39 being connected with the second solenoid valve 34, the other end being connected with the oil tank 6, for direct pressure relief of the rod cavity of the oil cylinder 2, for use in the back pressure of the glue melting, the glue injection and the rapid pressure relief in the pressure maintaining process.

[0031] Further, the oil supply circuit 4 comprises a first oil pump 41, a first servo controller 42, a second oil pump 43 and a second servo controller 44, one end of the first oil pump 41 being connected with the oil tank 6, the other end being connected with the control oil circuit 3, the first servo controller 42 controlling the opening and closing of the first oil pump 41, one end of the second oil pump 43 being connected with the oil tank 6, the other end being connected with the control oil circuit 3, the second servo controller 44 being used for controlling the opening and closing of the second oil pump 43, the first oil pump 41 and the second oil pump 43 being connected in parallel, and a one-way valve being arranged at the oil supply end of the first oil pump 41 and the second oil pump 43, for preventing the backflow of hydraulic oil, for inputting sufficient pressure and flow of hydraulic oil into the oil cylinder 2, and for adopting a servo system control, thereby shortening the reaction time in the system.

[0032] Preferably, the first oil pump 41 and the second oil pump 43 are double pumps, driven by one motor to provide oil pressure, thereby ensuring sufficient hydraulic supply, and the first oil pump 41 and the second oil pump 43 are connected in parallel, and through the redundant design of the parallel oil pumps, the stability of the oil pressure and flow to the oil cylinder 2 can be ensured.

[0033] Further, the cooling system 5 is further arranged, the cooling system 5 being communicated with the first oil pump 41 and the second oil pump 43, the first servo controller 42 and the second servo controller 44 controlling the first oil pump 41 and the second oil pump 43 to send oil to the cooling system 5, the hydraulic oil in the oil tank 6 being directly sent to the cooling system 5 for filtration and cooling, the hydraulic oil not having to flow back through the oil cylinder 2, thereby reducing the path length and resistance of the oil return of the oil cylinder 2, and improving the sensitivity of the action of the oil cylinder 2.

[0034] Further, the cooling system 5 comprises a filter 53, a cooler 51 and a third oil pump 52, one end of the filter 53 being communicated with the oil supply circuit 4, the other end being connected with one end of the cooler 51, the other end of the cooler 51 being connected with one end of the third oil pump 52, the other end of the third oil pump 52 being communicated with the oil tank 6, the filter 53 being used for removing impurities in the hydraulic oil, the cooler 51 being used for reducing the temperature of the hydraulic oil, and the third oil pump 52 being used for improving the power of the hydraulic oil circulation cooling, thereby ensuring the stability of the physical properties of the hydraulic oil.

[0035] Preferably, the cooling system 5 further comprises a cooling one-way valve 54, one end of the cooling one-way valve 54 being communicated with the oil supply circuit 4, the other end of the cooling one-way valve 54 being communicated with the oil tank 6, the cooling one-way valve 54 being connected in parallel with the cooler 51 to form an oil return branch, the oil return branch being used for shunting the hydraulic oil, thereby preventing excessive hydraulic oil from causing damage to the cooler 51.

[0036] Embodiment two

[0037] The embodiment also discloses an injection molding machine, which comprises a hydraulic cylinder high-speed oil supplement system and a glue injection screw rod 1, the hydraulic cylinder high-speed oil supplement system provides power for the action of the glue injection screw rod 1, and a glue injection cylinder 2 is driven to rotate by a glue melting motor 11, and the glue injection screw rod 1 is moved forward and backward by the glue injection cylinder 2 to complete the glue injection action.

[0038] The working process of the injection molding machine is as follows:

[0039] The motor 11 drives the glue injection screw rod 1 to rotate, and the plastic raw material in a molten state gradually fills the barrel, the back pressure pressure at the time of glue melting is first adjusted, that is, the reversing electromagnetic valve 39 is powered on, the third electromagnetic valve 36 is powered on, and the overflow pressure of the proportional overflow valve 381 is set, the cylinder 2 drives the screw rod to retreat backward, the rodless cavity of the cylinder 2 forms a vacuum negative pressure, under the suction force of the negative pressure, the first plug-in valve 31 is always open, the hydraulic oil is sucked into the rodless cavity of the cylinder 2 and filled; after the glue injection screw rod 1 completes the glue melting, the first oil pump 41 and the second oil pump 43 are started, the first electromagnetic valve 33 is powered on for reversing, the first plug-in valve 31 is closed, the second plug-in valve 32 is opened, the hydraulic oil is fed from the rodless cavity of the cylinder 2, the third electromagnetic valve 36 is powered on, the fourth plug-in valve 37 is opened, the glue injection screw rod 1 is quickly retreated to the corresponding position, and the cooling system 5 cools the hydraulic oil of the oil tank 6 after completing the glue injection action.

[0040] According to the disclosure and teaching of the above description, those skilled in the art of the present application can also make changes and modifications to the above embodiments. Therefore, the present application is not limited to the specific embodiments disclosed and described above, and some modifications and changes of the present application should also fall within the protection scope of the claims of the present application. In addition, although some specific terms are used in the present specification, these terms are only for convenience of description and do not constitute any limitation on the present application.

Claims

1. A high-speed oil replenishment system for a hydraulic cylinder, comprising a cylinder (2), a control oil circuit (3), an oil supply circuit (4), and an oil tank (6), wherein the control oil circuit (3) is connected to the cylinder (2), one end of the oil supply circuit (4) is connected to the control oil circuit (3), and the other end is connected to the oil tank (6), characterized in that: The control oil circuit (3) includes a first cartridge valve (31), a second cartridge valve (32), a third cartridge valve (35), a fourth cartridge valve (37), a first solenoid valve (33), a second solenoid valve (34), and a third solenoid valve (36). One end of the first cartridge valve (31) is connected to the rodless chamber of the cylinder (2), and the other end is connected to the oil tank (6). One end of the second cartridge valve (32) is connected to the rodless chamber of the cylinder (2), and the other end is connected to the oil supply circuit (4). The first solenoid valve (33) controls the first cartridge valve (31) and the second cartridge valve (32). The first cartridge valve (31) and the second cartridge valve (32) operate asynchronously. One end of the third cartridge valve (35) is connected to the rod chamber of the oil cylinder (2), and the other end is connected to the oil supply circuit (4). One end of the fourth cartridge valve (37) is connected to the rod chamber of the oil cylinder (2), and the other end is connected to the oil tank (6). The second solenoid valve (34) controls the opening and closing of the third cartridge valve (35), and the third solenoid valve (36) controls the opening and closing of the fourth cartridge valve (37). The third cartridge valve (35) and the fourth cartridge valve (37) operate asynchronously.

2. The high-speed oil replenishment system for hydraulic cylinders according to claim 1, characterized in that: The control oil circuit (3) also includes a pilot relief valve (38) and a proportional relief valve (381). One end of the pilot relief valve (38) is connected to the third solenoid valve (36), and the other end is connected to one end of the proportional relief valve (381). The other end of the proportional relief valve (381) is connected to the oil tank (6).

3. The high-speed oil replenishment system for hydraulic cylinders according to claim 2, characterized in that: The first solenoid valve (33) and the second solenoid valve (34) are two-position two-way valves used for oil switching. The third solenoid valve (36) is a two-position three-way valve used for oil switching and stopping. The first solenoid valve (33) remotely controls the opening and closing of the first cartridge valve (31).

4. The high-speed oil replenishment system for hydraulic cylinders according to claim 1, characterized in that: The control oil circuit (3) also includes a reversing solenoid valve (39), one end of which is connected to the second solenoid valve (34), and the other end is connected to the oil tank (6).

5. The high-speed oil replenishment system for hydraulic cylinders according to any one of claims 1-4, characterized in that: The oil supply circuit (4) includes a first oil pump (41), a first servo controller (42), a second oil pump (43), and a second servo controller (44). One end of the first oil pump (41) is connected to the oil tank (6), and the other end is connected to the control oil circuit (3). The first servo controller (42) controls the opening and closing of the first oil pump (41). One end of the second oil pump (43) is connected to the oil tank (6), and the other end is connected to the control oil circuit (3). The second servo controller (44) is used to control the opening and closing of the second oil pump (43).

6. The high-speed oil replenishment system for hydraulic cylinders according to claim 5, characterized in that: The first oil pump (41) and the second oil pump (43) are a tandem pump, and the first oil pump (41) and the second oil pump (43) are connected in parallel.

7. The high-speed oil replenishment system for hydraulic cylinders according to claim 5, characterized in that: It also includes a cooling system (5) connected to the first oil pump (41) and the second oil pump (43).

8. The high-speed oil replenishment system for hydraulic cylinders according to claim 7, characterized in that: The cooling system (5) includes a filter (53), a cooler (51) and a third oil pump (52). One end of the filter (53) is connected to the oil supply circuit (4), and the other end is connected to one end of the cooler (51). The other end of the cooler (51) is connected to one end of the third oil pump (52), and the other end of the third oil pump (52) is connected to the oil tank (6).

9. The high-speed oil replenishment system for hydraulic cylinders according to claim 8, characterized in that: The cooling system (5) also includes a cooling check valve (54), one end of which is connected to the oil supply circuit (4), and the other end of which is connected to the oil tank (6). The cooling check valve (54) and the cooler (51) are connected in parallel to form a return oil branch.

10. An injection molding machine, comprising a high-speed hydraulic cylinder replenishment system as described in any one of claims 1-9 and an injection screw (1), wherein the high-speed hydraulic cylinder replenishment system provides power for the movement of the injection screw (1).

Images