Proportional control mold opening and closing hydraulic circuit of injection molding machine

Abstract

The utility model provides a proportional control mold opening and closing hydraulic loop of an injection molding machine, which belongs to the technical field of hydraulic loops of injection molding machines and comprises a pressure oil supply end, an oil tank, a mold locking oil cylinder, a mold opening and closing reversing valve, a one-way valve and a proportional throttle valve. The low-cost proportional throttle valve is adopted, meanwhile, the double-flow-channel application is adopted, the flow rate of the proportional valve is increased, the hydraulic loop cost is further reduced, hydraulic oil is blocked by the proportional throttle valve, hydraulic oil in a rod cavity of the mold locking oil cylinder can only flow to the mold opening and closing reversing valve again through the one-way valve, differential mold closing is conducted, an oil way is simplified, and the cost is further reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of hydraulic circuits for injection molding machines, and relates to a proportional control mold opening and closing hydraulic circuit for injection molding machines. Background Art

[0002] With the development of the industry, more and more injection molding machines are equipped with robotic arms to pick up parts to meet the needs of automated production. This puts higher requirements on the mold opening and closing accuracy of the injection molding machines. At present, injection molding machines are equipped with proportional directional valves in the mold opening and closing oil circuits to improve the mold opening and closing accuracy.

[0003] For example, a utility model patent with application number CN202121516811.9 provides a hydraulic circuit for opening and closing molds of an injection molding machine, which includes a pressure oil supply end, an oil tank, a locking cylinder, an opening and closing mold reversing valve, a differential valve, a hydraulic safety valve control valve, a hydraulic safety valve, an electromagnetic proportional relief valve, and a brake valve. The opening and closing mold reversing valve is composed of a main valve and a pilot valve. The return oil of the mold closing action and the mold opening action returns to the oil tank through the brake valve. By setting the overflow pressure of the electromagnetic proportional relief valve, the mold opening and breaking section and the final braking section of the mold opening action have a large return oil back pressure, while the middle fast section has almost no return oil back pressure.

[0004] In summary, although some existing technical solutions have solved the problem of mold opening and closing accuracy, due to the high cost of the proportional directional valve itself, there is still the problem of high machine cost, and there is much room for improvement. Summary of the invention

[0005] The purpose of the utility model is to solve the above problems in the prior art and propose a proportional control mold opening and closing hydraulic circuit for an injection molding machine, comprising:

[0006] Pressure oil supply end, oil tank, clamping cylinder;

[0007] It also includes a mold opening and closing reversing valve, a one-way valve and a proportional throttle valve; the mold opening and closing reversing valve includes a reversing oil inlet, a reversing oil return port, a first reversing working oil port and a second reversing working oil port, the proportional throttle valve includes a throttling oil inlet, a throttling oil return port, a first throttling working oil port and a second throttling working oil port, the one-way valve includes a one-way oil inlet and a one-way oil return port, the reversing oil inlet is connected to the pressure oil supply end, the second plug-in working oil port is connected to the first reversing working oil port, the first plug-in working oil port is connected to the rodless chamber of the clamping cylinder, the second throttling working oil port and the throttling oil return port are both connected to the oil tank, the throttling oil inlet and the first throttling working oil port are both connected to the reversing oil return port, the second reversing working oil port is connected to the rod chamber of the clamping cylinder, the one-way oil inlet is connected to the rod chamber of the clamping cylinder, and the one-way oil return port is connected to the reversing oil inlet;

[0008] The hydraulic oil provided by the pressure oil supply end enters the rodless chamber of the mold clamping cylinder through the mold opening and closing reversing valve, and the hydraulic oil in the rod chamber of the mold clamping cylinder sequentially passes through the mold opening and closing reversing valve and the proportional throttle valve to return to the oil tank to complete the mold clamping action;

[0009] The hydraulic oil provided by the pressure oil supply end enters the rodless chamber of the mold clamping cylinder through the mold opening and closing reversing valve. When the hydraulic oil is blocked by the proportional throttle valve, the hydraulic oil in the rod chamber of the mold clamping cylinder passes through the one-way valve and the mold opening and closing reversing valve in sequence and enters the rodless chamber of the mold clamping cylinder to complete differential mold clamping.

[0010] The hydraulic oil provided by the pressure oil supply end enters the rod chamber of the clamping cylinder through the mold opening and closing reversing valve. The hydraulic oil in the rodless chamber of the clamping cylinder passes through the mold opening and closing reversing valve and the proportional throttle valve in turn and returns to the oil tank to complete the mold opening action.

[0011] In the above-mentioned proportional control mold opening and closing hydraulic circuit of an injection molding machine, the mold opening and closing reversing valve is provided with a first reversing position, an intermediate reversing position and a second reversing position, and the mold opening and closing reversing valve includes a first electromagnet. When the first electromagnet is energized, the valve core of the mold opening and closing reversing valve moves from the intermediate reversing position to the first reversing position, so that the reversing oil inlet is connected with the first reversing working oil port, and the second reversing working oil port is connected with the reversing oil return port, so that the hydraulic oil provided by the pressure oil supply end passes through the reversing oil inlet to the first reversing working oil port, and then passes through the second plug-in working oil port to the first plug-in working oil port and then enters the rodless chamber of the clamping cylinder, pushing The piston rod of the mold locking cylinder is pushed forward, and the proportional throttle valve is provided with a first throttling position and a second throttling position. The proportional throttle valve includes a proportional solenoid. When the proportional solenoid is energized, the valve core of the proportional throttle valve moves from the first throttling position to the second throttling position, so that the first throttling working oil port is connected with the throttling return oil port, and the throttling oil inlet is connected with the second throttling working oil port, so that the hydraulic oil in the rod chamber of the mold locking cylinder passes through the second reversing working oil port to the reversing oil return port, and then passes through the first throttling working oil port and the throttling oil inlet to the second throttling working oil port and the throttling return oil port, and then to the oil tank to complete the mold closing action.

[0012] In the above-mentioned proportional control mold opening and closing hydraulic circuit of an injection molding machine, the mold opening and closing reversing valve also includes a second electromagnet. When the second electromagnet is energized, the valve core of the mold opening and closing reversing valve moves from the first reversing position to the second reversing position, so that the reversing oil inlet is connected to the second reversing working oil port, and the reversing oil return port is connected to the first reversing working oil port, so that the hydraulic oil provided by the pressure oil supply end passes through the reversing oil inlet to the second reversing working oil port and then enters the rod chamber of the clamping cylinder, pushing the clamping cylinder The piston rod is pushed back, and when the proportional solenoid is energized, the valve core of the proportional throttle valve moves from the first throttling position to the second throttling position, so that the first throttling working oil port is connected with the throttling return oil port, and the second throttling working oil port is connected with the throttling oil inlet port, so that the hydraulic oil in the rodless chamber of the locking cylinder passes through the first reversing working oil port to the reversing oil return port, and then passes through the first throttling working oil port and the throttling oil inlet port to the second throttling working oil port and the throttling return oil port, and then to the oil tank, completing the mold opening action.

[0013] In the above-mentioned proportional control mold opening and closing hydraulic circuit of an injection molding machine, when the first electromagnet is energized and the proportional electromagnet is not energized, the valve core of the mold opening and closing reversing valve moves from the second reversing position to the first reversing position, the valve core of the proportional throttle valve moves from the second throttling position to the first throttling position, the reversing oil inlet is connected with the first reversing working oil port, the reversing oil return port is connected with the second reversing working oil port, the hydraulic oil is blocked by the proportional throttle valve, and the hydraulic oil in the rod chamber of the locking cylinder passes through the one-way oil inlet to the one-way oil return port, and then passes through the reversing oil inlet to the first reversing working oil port, and then to the rodless chamber of the locking cylinder to complete differential mold closing.

[0014] In the above-mentioned proportional control mold opening and closing hydraulic circuit of an injection molding machine, it also includes a cartridge valve, the mold opening and closing reversing valve is connected to the locking cylinder through the cartridge valve, the cartridge valve includes a first cartridge working oil port and a second cartridge working oil port, the first cartridge working oil port is connected to the rodless chamber of the locking cylinder, the second cartridge working oil port is connected to the first reversing working oil port, the cartridge valve is provided with a first cartridge position and a second cartridge position, when the valve core of the cartridge valve is in the first cartridge position, the first cartridge working oil port can be connected to the second cartridge working oil port, when the valve core of the cartridge valve is in the second cartridge position, the first cartridge working oil port is disconnected from the second cartridge working oil port.

[0015] In the above-mentioned proportional control mold opening and closing hydraulic circuit of an injection molding machine, it also includes a pilot control valve, the pilot control valve includes a first control working oil port, a control oil inlet port and a control oil return port, the cartridge valve also includes a cartridge control port, the control oil return port is connected to the oil tank, the first control working oil port is connected to the cartridge control port, the control oil inlet port is connected to the first reversing working oil port, the pilot control valve is provided with a first control position and a second control position, the pilot control valve includes a third electromagnet, when the third electromagnet is energized, the valve core of the pilot control valve moves from the second control position to the first control position, the first control working oil port is connected to the control oil return port, the hydraulic oil in the cartridge valve flows out from the cartridge control port, passes through the first control working oil port to the control oil return port , and then to the oil tank, so that the valve core of the cartridge valve moves from the second cartridge position to the first cartridge position, and then the valve core in the cartridge valve makes the first cartridge working oil port connected with the second cartridge working oil port. When the third solenoid is not energized, the valve core of the pilot control valve moves from the first control position to the second control position, and the control oil inlet is connected with the first control working oil port. The hydraulic oil provided by the pressure oil supply end passes through the reversing working oil port to the first reversing working oil port, and then passes through the control oil inlet to the first control working oil port, and then flows into the cartridge valve through the cartridge control port, so that the valve core of the cartridge valve moves from the first cartridge position to the second cartridge position, and then the first cartridge working oil port is disconnected from the second cartridge working oil port.

[0016] In the above-mentioned proportional control mold opening and closing hydraulic circuit of an injection molding machine, the oil port size of the proportional throttle valve can be proportionally adjusted by the given signal of the proportional electromagnet.

[0017] In the above-mentioned proportional control mold opening and closing hydraulic circuit of an injection molding machine, the mold opening and closing reversing valve is an electromagnetic reversing valve, the pilot control valve is an electromagnetic reversing valve, and the proportional throttle valve is an electromagnetic reversing valve.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] 1. The low-cost proportional throttle valve is adopted, and the dual-channel application increases the flow rate of the proportional valve, further reducing the cost of the hydraulic circuit.

[0020] 2. During mold closing and opening, the oil return from the cylinder is finally controlled by the proportional throttle valve. The oil return back pressure is controlled by adjusting the opening of the proportional valve to improve the accuracy of mold opening and closing.

[0021] 3. The hydraulic oil is blocked by the proportional throttle valve, and the hydraulic oil in the rod chamber of the clamping cylinder can only flow back to the opening and closing mold reversing valve through the one-way valve to perform differential mold clamping, simplify the oil circuit, and further reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The utility model is a schematic diagram of a proportional control mold opening and closing hydraulic circuit of an injection molding machine.

[0023] In the figure:

[0024] 1. Pressure oil supply end; 2. Oil tank; 3. Clamping cylinder; 31. Rodless chamber; 32. Rod chamber; V1. Opening and closing mold reversing valve; A1. First reversing working oil port; B1. Second reversing working oil port; P1. Reversing oil inlet; T1. Reversing oil return port; V2. Proportional throttle valve; A2. First throttling working oil port; B2. Second throttling working oil port; P2. Throttling oil inlet; T2. Throttling oil return port; V3, one-way valve; I, one-way oil inlet; O, one-way oil return; V4, cartridge valve; A4, first cartridge working oil port; B4, second cartridge working oil port; C4, cartridge control port; V5, pilot control valve; A5, first control working oil port; P5, control oil inlet; T5, control oil return; D1: first solenoid; D2: second solenoid; D3: third solenoid; DF3: proportional solenoid. DETAILED DESCRIPTION

[0025] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0026] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0027] In addition, in the present invention, the descriptions of "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0028] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] 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 the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0030] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0031] like Figure 1 As shown, a proportional control mold opening and closing hydraulic circuit of an injection molding machine includes a pressure oil supply terminal 1, an oil tank 2, and a mold locking cylinder 3;

[0032] Among them, it also includes a mold opening and closing reversing valve V1, a one-way valve V3 and a proportional throttle valve V2; the mold opening and closing reversing valve V1 includes a reversing oil inlet P1, a reversing oil return port T1, a first reversing working oil port A1 and a second reversing working oil port B1, the proportional throttle valve V2 includes a throttling oil inlet P2, a throttling oil return port T2, a first throttling working oil port A2 and a second throttling working oil port B2, the one-way valve V3 includes a one-way oil inlet I and a one-way oil return port O, the reversing oil inlet P1 is connected to the pressure oil supply end 1, and the second plug-in working oil port B 4 is communicated with the first reversing working oil port A1, the first plug-in working oil port A4 is communicated with the rodless chamber 31 of the clamping cylinder 3, the second throttling working oil port B2 and the throttling oil return port T2 are both communicated with the oil tank 2, the throttling oil inlet port P2 and the first throttling working oil port A2 are both communicated with the reversing oil return port T1, the second reversing working oil port B1 is communicated with the rod chamber 32 of the clamping cylinder 3, the one-way oil inlet port I is communicated with the rod chamber 32 of the clamping cylinder 3, and the one-way oil return port O is communicated with the reversing oil inlet port P1.

[0033] The hydraulic oil provided by the pressure oil supply end 1 enters the rodless chamber 31 of the clamping cylinder 3 through the mold opening and closing reversing valve V1, and the hydraulic oil in the rod chamber 32 of the clamping cylinder 3 passes through the mold opening and closing reversing valve V1 and the proportional throttle valve V2 in turn and returns to the oil tank 2 to complete the clamping action.

[0034] The hydraulic oil provided by the pressure oil supply end 1 enters the rodless chamber 31 of the locking cylinder 3 through the mold opening and closing reversing valve V1. When the hydraulic oil is blocked by the proportional throttle valve V2, the hydraulic oil in the rod chamber 32 of the locking cylinder 3 passes through the one-way valve V3 and the mold opening and closing reversing valve V1 in turn and enters the rodless chamber 31 of the locking cylinder 3 to complete differential clamping.

[0035] The hydraulic oil provided by the pressure oil supply end 1 enters the rod chamber 32 of the clamping cylinder 3 through the mold opening and closing reversing valve V1, and the hydraulic oil in the rodless chamber 31 of the clamping cylinder 3 passes through the mold opening and closing reversing valve V1 and the proportional throttle valve V2 in turn and returns to the oil tank 2 to complete the mold opening action.

[0036] In this embodiment, a low-cost proportional throttle valve V2 is used, and a dual-channel application is adopted to increase the flow rate of the proportional valve, further reducing the cost of the hydraulic circuit.

[0037] like Figure 1As shown, on the basis of the above-mentioned embodiment, the mold opening and closing reversing valve V1 is provided with a first reversing position, an intermediate reversing position and a second reversing position, and the mold opening and closing reversing valve V1 includes a first electromagnet D1. When the first electromagnet D1 is energized, the valve core of the mold opening and closing reversing valve V1 moves from the intermediate reversing position to the first reversing position, so that the reversing oil inlet P1 is connected with the first reversing working oil port A1, and the second reversing working oil port B2 is connected with the reversing oil return port T1, so that the hydraulic oil provided by the pressure oil supply end 1 passes through the reversing oil inlet P1 to the first reversing working oil port A1, and then passes through the second plug-in working oil port B4 to the first plug-in working oil port A4, and then enters the rodless chamber 31 of the clamping cylinder 3, pushing the clamping cylinder 3's piston rod is pushed forward, the proportional throttle valve V2 is provided with a first throttling position and a second throttling position, the proportional throttle valve V2 includes a proportional solenoid DF3, when the proportional solenoid DF3 is energized, the valve core of the proportional throttle valve V2 moves from the first throttling position to the second throttling position, so that the first throttling working oil port A2 is connected with the throttling return oil port T2, and the throttling oil inlet port P2 is connected with the second throttling working oil port B2, so that the hydraulic oil in the rod chamber 32 of the clamping cylinder 3 passes through the second reversing working oil port B1 to the reversing return oil port T1, and then passes through the first throttling working oil port A2 and the throttling oil inlet port P2 to the second throttling working oil port B2 and the throttling return oil port T2, and then to the oil tank 2, to complete the mold closing action.

[0038] Specifically, when the valve core of the mold opening and closing reversing valve V1 is in the left position, it is the first reversing position, and when it is in the right position, it is the second reversing position. When the valve core of the proportional throttle valve V2 is in the left position, it is the first throttling position, and when it is in the right position, it is the second throttling position.

[0039] In this embodiment, the hydraulic oil provided by the pressure oil supply end 1 passes through the opening and closing reversing valve and enters the rodless chamber 31 of the locking cylinder 3 to push the mold to close the mold, while the hydraulic oil in the rod chamber 32 of the locking cylinder 3 passes through the opening and closing reversing valve V1 and then passes through the proportional throttle valve V2 to enter the oil tank 2 to complete the mold closing action.

[0040] like Figure 1As shown, on the basis of the above embodiment, the mold opening and closing reversing valve V1 further includes a second electromagnet D2. When the second electromagnet D2 is energized, the valve core of the mold opening and closing reversing valve V1 moves from the first reversing position to the second reversing position, so that the reversing oil inlet P1 is connected with the second reversing working oil port B1, and the reversing oil return port T1 is connected with the first reversing working oil port A1, so that the hydraulic oil provided by the pressure oil supply end 1 passes through the reversing oil inlet P1 to the second reversing working oil port B1 and then enters the rod chamber 32 of the clamping cylinder 3, pushing the piston rod of the clamping cylinder 3 to retract. When the proportional solenoid DF3 is energized, the valve core of the proportional throttle valve V2 moves from the first throttling position to the second throttling position, so that the first throttling working oil port A2 is connected with the throttling return oil port T2, and the second throttling working oil port B2 is connected with the throttling oil inlet port P2, so that the hydraulic oil in the rodless chamber 31 of the locking cylinder 3 passes through the first reversing working oil port A1 to the reversing oil return port T1, and then passes through the first throttling working oil port A2 and the throttling oil inlet port P2 to the second throttling working oil port B2 and the throttling return oil port T2, and then to the oil tank 2, completing the mold opening action.

[0041] Specifically, after the valve core of the mold opening and closing reversing valve V1 moves from the first reversing position to the second reversing position, the first reversing working oil port A1 is connected with the reversing return oil port T1, and the reversing oil inlet port P1 is connected with the second reversing working oil port B1. The hydraulic oil provided by the pressure oil supply end 1 enters the rod chamber 32 of the mold locking cylinder 3 through the mold opening and closing reversing valve V1, pushing the piston rod of the mold locking cylinder 3 to retreat. After the valve core of the proportional throttle valve V2 moves from the first throttling position to the second throttling position, the first throttling working oil port A2 is connected with the throttling return oil port T2, and the throttling oil inlet port P2 is connected with the second throttling working oil port B2. The hydraulic oil in the rodless chamber 31 of the mold locking cylinder 3 passes through the cartridge valve V4 and flows to the mold opening and closing reversing valve V1, and then flows into the oil tank 2 through the proportional throttle valve V2 to complete the mold opening action.

[0042] In this embodiment, the proportional throttle valve V2 adopts dual-channel application at the same time, which increases the flow rate of the proportional AC valve compared with the single-channel design of the prior art.

[0043] like Figure 1As shown, on the basis of the above-mentioned embodiment, when the first electromagnet D1 is energized and the proportional electromagnet DF3 is not energized, the valve core of the opening and closing mold reversing valve V1 moves from the second reversing position to the first reversing position, the valve core of the proportional throttle valve V2 moves from the second throttling position to the first throttling position, the reversing oil inlet P1 is connected with the first reversing working oil port A1, the reversing oil return port T1 is connected with the second reversing working oil port B1, the hydraulic oil is blocked by the proportional throttle valve V2, and the hydraulic oil in the rod chamber 32 of the locking cylinder 3 passes through the one-way oil inlet I to the one-way oil return port O, and then passes through the reversing oil inlet P1 to the first reversing working oil port A1, and then to the rodless chamber 31 of the locking cylinder 3, to complete the differential mold closing.

[0044] In this embodiment, when the hydraulic oil is blocked by the proportional throttle valve V2, the hydraulic oil in the rod chamber 32 of the clamping cylinder 3 can only flow back to the mold opening and closing reversing valve V1 through the one-way valve V3 to perform differential mold closing, simplify the oil circuit, and further reduce costs.

[0045] like Figure 1 As shown, on the basis of the above embodiment, it also includes a cartridge valve V4, the opening and closing mold reversing valve V1 is connected with the locking cylinder 3 through the cartridge valve V4, the cartridge valve V4 includes a first cartridge working oil port A4 and a second cartridge working oil port B4, the first cartridge working oil port A4 is connected with the rodless chamber 31 of the locking cylinder 3, the second cartridge working oil port B4 is connected with the first reversing working oil port A1, the cartridge valve V4 is provided with a first cartridge position and a second cartridge position, when the valve core of the cartridge valve V4 is in the first cartridge position, the first cartridge working oil port A4 can be connected with the second cartridge working oil port B4, when the valve core of the cartridge valve V4 is in the second cartridge position, the first cartridge working oil port A4 is disconnected from the second cartridge working oil port B4.

[0046] Specifically, when the valve core of the cartridge valve V4 is at the bottom, it is at the first cartridge position, and when it is at the top, it is at the second cartridge position.

[0047] In this embodiment, the communication and blockage between the mold opening and closing reversing valve V1 and the rodless chamber 31 of the mold locking cylinder 3 is controlled by the cartridge valve V4 .

[0048] like Figure 1As shown, on the basis of the above embodiment, it also includes a pilot control valve V5, the pilot control valve V5 includes a first control working oil port A5, a control oil inlet P5 and a control oil return port T5, the cartridge valve V4 also includes a cartridge control port C4, the control oil return port T5 is connected to the oil tank 2, the first control working oil port A5 is connected to the cartridge control port C4, the control oil inlet P5 is connected to the first reversing working oil port A1, the pilot control valve V5 is provided with a first control position and a second control position, the pilot control valve V5 includes a third electromagnet D3, when the third electromagnet D3 is energized, the valve core of the pilot control valve V5 moves from the second control position to the first control position, the first control working oil port A5 is connected to the control oil return port T5, the hydraulic oil in the cartridge valve V4 flows out from the cartridge control port C4, passes through the first control working oil port A5 to the control oil return port T5, Port T5, and then to the oil tank 2, so that the valve core of the cartridge valve V4 moves from the second cartridge position to the first cartridge position, and then the valve core in the cartridge valve V4 makes the first cartridge working oil port A4 communicate with the second cartridge working oil port B4. When the third solenoid D3 is not energized, the valve core of the pilot control valve V5 moves from the first control position to the second control position, and the control oil inlet P5 is communicated with the first control working oil port A5. The hydraulic oil provided by the pressure oil supply end 1 passes through the reversing working oil port to the first reversing working oil port A1, and then passes through the control oil inlet P5 to the first control working oil port A5, and then flows into the cartridge valve V4 through the cartridge control port C4, so that the valve core of the cartridge valve V4 moves from the first cartridge position to the second cartridge position, and then the first cartridge working oil port A4 is disconnected from the second cartridge working oil port B4.

[0049] Specifically, when the valve core of the pilot control valve V5 is in the left position, it is the first control position, and when it is in the right position, it is the second control position. When the third electromagnet D3 is not energized, the valve core of the pilot control valve V5 will move from the first control position to the second control position again under the action of the elastic element. At this time, the control oil inlet P5 is connected with the first reversing working oil, and the first control working oil port A5 is connected with the cartridge control port C4. The hydraulic oil provided by the pressure oil supply end flows into the cartridge valve V4 through the opening and closing mold reversing valve V1 and the pilot control valve V5, pushing the valve core inside the cartridge valve V4, so that the hydraulic oil is blocked by the cartridge valve V4, cutting off the mold closing action.

[0050] In this embodiment, the mold closing action can be quickly cut off by controlling the third electromagnet D3, which can play a role of safety protection during use.

[0051] like Figure 1As shown, based on the above implementation, the oil port size of the proportional throttle valve V2 can be proportionally adjusted by the given signal of the proportional solenoid DF3.

[0052] In this embodiment, when the mold closing and opening actions are performed, the return oil of the cylinder is finally controlled by proportional throttling through the proportional throttle valve V2, and the return oil back pressure is controlled by adjusting the opening of the proportional throttle valve V2, thereby improving the accuracy of the mold opening and closing actions.

[0053] like Figure 1 As shown, on the basis of the above embodiment, the mold opening and closing reversing valve V1 is an electromagnetic reversing valve, the pilot control valve V5 is an electromagnetic reversing valve, and the proportional throttle valve V2 is an electromagnetic reversing valve.

[0054] In this embodiment, the electromagnetic reversing valve can control the position of the valve core by energizing and de-energizing the electromagnet, and can achieve rapid response and precise control, completing the opening or closing action in a short time.

Claims

1. A proportional control mold opening and closing hydraulic circuit for an injection molding machine, comprising a pressure oil supply end, an oil tank, and a mold locking cylinder, characterized in that: Also includes: A mold opening and closing reversing valve, a one-way valve and a proportional throttle valve; the mold opening and closing reversing valve includes a reversing oil inlet, a reversing oil return port, a first reversing working oil port and a second reversing working oil port, the proportional throttle valve includes a throttling oil inlet, a throttling oil return port, a first throttling working oil port and a second throttling working oil port, the one-way valve includes a one-way oil inlet and a one-way oil return port, the reversing oil inlet is connected to the pressure oil supply end, the second plug-in working oil port is connected to the first reversing working oil port, the first plug-in working oil port is connected to the rodless chamber of the clamping cylinder, the second throttling working oil port and the throttling oil return port are both connected to the oil tank, the throttling oil inlet and the first throttling working oil port are both connected to the reversing oil return port, the second reversing working oil port is connected to the rod chamber of the clamping cylinder, the one-way oil inlet is connected to the rod chamber of the clamping cylinder, and the one-way oil return port is connected to the reversing oil inlet; The hydraulic oil provided by the pressure oil supply end enters the rodless chamber of the mold clamping cylinder through the mold opening and closing reversing valve, and the hydraulic oil in the rod chamber of the mold clamping cylinder sequentially passes through the mold opening and closing reversing valve and the proportional throttle valve to return to the oil tank to complete the mold clamping action; The hydraulic oil provided by the pressure oil supply end enters the rodless chamber of the mold clamping cylinder through the mold opening and closing reversing valve. When the hydraulic oil is blocked by the proportional throttle valve, the hydraulic oil in the rod chamber of the mold clamping cylinder passes through the one-way valve and the mold opening and closing reversing valve in sequence and enters the rodless chamber of the mold clamping cylinder to complete differential mold clamping. The hydraulic oil provided by the pressure oil supply end enters the rod chamber of the clamping cylinder through the mold opening and closing reversing valve. The hydraulic oil in the rodless chamber of the clamping cylinder passes through the mold opening and closing reversing valve and the proportional throttle valve in turn and returns to the oil tank to complete the mold opening action.

2. The proportional control mold opening and closing hydraulic circuit of an injection molding machine according to claim 1, characterized in that: The mold opening and closing reversing valve is provided with a first reversing position, an intermediate reversing position and a second reversing position. The mold opening and closing reversing valve includes a first electromagnet. When the first electromagnet is energized, the valve core of the mold opening and closing reversing valve moves from the intermediate reversing position to the first reversing position, so that the reversing oil inlet is connected with the first reversing working oil port, and the second reversing working oil port is connected with the reversing oil return port, so that the hydraulic oil provided by the pressure oil supply end passes through the reversing oil inlet to the first reversing working oil port, and then passes through the second plug-in working oil port to the first plug-in working oil port and then enters the rodless chamber of the clamping cylinder to push the piston rod of the clamping cylinder. Push forward, the proportional throttle valve is provided with a first throttling position and a second throttling position, and the proportional throttle valve includes a proportional solenoid. When the proportional solenoid is energized, the valve core of the proportional throttle valve moves from the first throttling position to the second throttling position, so that the first throttling working oil port is connected with the throttling return oil port, and the throttling oil inlet is connected with the second throttling working oil port, so that the hydraulic oil in the rod chamber of the locking cylinder passes through the second reversing working oil port to the reversing oil return port, and then passes through the first throttling working oil port and the throttling oil inlet to the second throttling working oil port and the throttling return oil port, and then to the oil tank to complete the mold closing action.

3. The proportional control mold opening and closing hydraulic circuit of an injection molding machine according to claim 2, characterized in that: The mold opening and closing reversing valve further comprises a second electromagnet. When the second electromagnet is energized, the valve core of the mold opening and closing reversing valve moves from the first reversing position to the second reversing position, thereby connecting the reversing oil inlet to the second reversing working oil port, and connecting the reversing oil return port to the first reversing working oil port, so that the hydraulic oil provided by the pressure oil supply end passes through the reversing oil inlet to the second reversing working oil port and then enters the rod chamber of the mold locking cylinder, pushing the piston rod of the mold locking cylinder to retreat. When the ratio For example, when the electromagnet is energized, the valve core of the proportional throttle valve moves from the first throttling position to the second throttling position, so that the first throttling working oil port is connected with the throttling return oil port, and the second throttling working oil port is connected with the throttling oil inlet port, so that the hydraulic oil in the rodless chamber of the clamping cylinder passes through the first reversing working oil port to the reversing oil return port, and then passes through the first throttling working oil port and the throttling oil inlet port to the second throttling working oil port and the throttling return oil port, and then to the oil tank, completing the mold opening action.

4. The proportional control mold opening and closing hydraulic circuit of an injection molding machine according to claim 3, characterized in that: When the first electromagnet is energized and the proportional electromagnet is not energized, the valve core of the opening and closing mold reversing valve moves from the second reversing position to the first reversing position, the valve core of the proportional throttle valve moves from the second throttling position to the first throttling position, the reversing oil inlet is connected with the first reversing working oil port, the reversing oil return port is connected with the second reversing working oil port, the hydraulic oil is blocked by the proportional throttle valve, and the hydraulic oil in the rod chamber of the locking cylinder passes through the one-way oil inlet to the one-way oil return port, and then passes through the reversing oil inlet to the first reversing working oil port, and then to the rodless chamber of the locking cylinder to complete differential mold closing.

5. The proportional control mold opening and closing hydraulic circuit of an injection molding machine according to claim 1, characterized in that: It also includes a cartridge valve, the opening and closing mold reversing valve is connected to the locking cylinder through the cartridge valve, the cartridge valve includes a first cartridge working oil port and a second cartridge working oil port, the first cartridge working oil port is connected to the rodless chamber of the locking cylinder, the second cartridge working oil port is connected to the first reversing working oil port, the cartridge valve is provided with a first cartridge position and a second cartridge position, when the valve core of the cartridge valve is in the first cartridge position, the first cartridge working oil port can be connected to the second cartridge working oil port, when the valve core of the cartridge valve is in the second cartridge position, the first cartridge working oil port is disconnected from the second cartridge working oil port.

6. The proportional control mold opening and closing hydraulic circuit of an injection molding machine according to claim 5, characterized in that: It also includes a pilot control valve, the pilot control valve includes a first control working oil port, a control oil inlet port and a control oil return port, the cartridge valve also includes a cartridge control port, the control oil return port is connected to the oil tank, the first control working oil port is connected to the cartridge control port, the control oil inlet port is connected to the first reversing working oil port, the pilot control valve is provided with a first control position and a second control position, the pilot control valve includes a third electromagnet, when the third electromagnet is energized, the valve core of the pilot control valve moves from the second control position to the first control position, the first control working oil port is connected to the control oil return port, the hydraulic oil in the cartridge valve flows out from the cartridge control port, passes through the first control working oil port to the control oil return port, and then to the oil tank, so that The valve core of the cartridge valve moves from the second cartridge position to the first cartridge position, thereby causing the valve core in the cartridge valve to connect the first cartridge working oil port with the second cartridge working oil port. When the third electromagnet is not energized, the valve core of the pilot control valve moves from the first control position to the second control position, and the control oil inlet is connected with the first control working oil port. The hydraulic oil provided by the pressure oil supply end passes through the reversing working oil port to the first reversing working oil port, and then passes through the control oil inlet to the first control working oil port, and then flows into the cartridge valve through the cartridge control port, thereby causing the valve core of the cartridge valve to move from the first cartridge position to the second cartridge position, thereby disconnecting the first cartridge working oil port from the second cartridge working oil port.

7. The proportional control mold opening and closing hydraulic circuit of an injection molding machine according to claim 4, characterized in that: The oil port size of the proportional throttle valve can be proportionally adjusted by the given signal of the proportional solenoid.

8. The proportional control mold opening and closing hydraulic circuit of an injection molding machine according to claim 6, characterized in that: The mold opening and closing reversing valve is an electromagnetic reversing valve, the pilot control valve is an electromagnetic reversing valve, and the proportional throttle valve is an electromagnetic reversing valve.

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