Ejection oil cylinder movement positioning hydraulic circuit and die casting machine

Abstract

The utility model discloses an ejection oil cylinder motion positioning hydraulic loop and a die casting machine, and relates to the technical field of die casting machines, the ejection oil cylinder motion positioning hydraulic loop comprises an ejection oil cylinder, a rod cavity and a rodless cavity; the pipeline assembly comprises an oil inlet pipeline and an oil return pipeline; the reversing valve is communicated with the ejection oil cylinder through the oil inlet pipeline and the oil return pipeline and is used for realizing reversing adjustment of the oil inlet pipeline or the oil return pipeline; the flow valve is arranged on the oil return pipeline and used for adjusting the flow of the oil return pipeline; the detection assembly is used for detecting the position of a piston rod of the ejection oil cylinder; and the control assembly is electrically connected with the detection assembly. The opening degree of the flow valve is controlled to be gradually reduced through the control assembly, so that the flow flowing into the flow valve through the oil return pipeline is adjusted until the piston rod of the ejection oil cylinder reaches the set position to close the flow valve, and the accuracy of ejecting the die casting to the preset position by the ejection oil cylinder is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of die-casting machines, in particular to a hydraulic circuit for positioning a ejection oil cylinder movement and a die-casting machine. Background Art

[0002] With the popularization of automatic operation of die-casting machines, more and more die-casting machines are equipped with automatic retrieval systems, so as to conveniently and timely remove die-castings. In the process of automatic retrieval of die-casting machines, the die-casting machine first ejects the die-casting in the mold to the preset position through the ejection cylinder, and the automatic retrieval system then clamps and removes the die-casting through the clamping mechanism.

[0003] However, during the ejection process, the existing ejection cylinder fails to eject the die-casting to the preset position due to inaccurate positioning of the ejection cylinder, resulting in the inability of the retrieval system to clamp the die-casting or the clamping area of ​​the die-casting is too small, which causes the die-casting to fall during the retrieval process. Utility Model Content

[0004] The main purpose of the utility model is to provide a hydraulic circuit for positioning a ejection oil cylinder, so as to improve the accuracy of the ejection oil cylinder in ejecting a die casting to a preset position.

[0005] In order to achieve the above-mentioned purpose, the utility model proposes a hydraulic circuit for positioning the movement of an ejection cylinder, wherein the hydraulic circuit for positioning the movement of an ejection cylinder comprises an ejection cylinder, including a rod chamber and a rodless chamber;

[0006] Pipeline components, including oil inlet pipeline and oil return pipeline;

[0007] a reversing valve, connected to the ejection oil cylinder through the oil inlet pipeline and the oil return pipeline, for realizing the reversing adjustment of the oil inlet pipeline or the oil return pipeline, so that one of the oil inlet pipeline and the oil return pipeline is selectively connected to the rod chamber of the ejection oil cylinder, and the other is connected to the rodless chamber of the ejection oil cylinder;

[0008] a flow valve, arranged in the oil return pipeline, for adjusting the flow of the oil return pipeline, one end of the flow valve being connected to the reversing valve, and the other end being connected to the oil tank; and

[0009] A detection component, used for detecting the position of the piston rod of the ejection cylinder;

[0010] A control component is electrically connected to the detection component and is used to control the opening of the flow valve. When the detection component detects that the piston rod of the ejection cylinder is close to a set position, the control component controls the opening of the flow valve to gradually decrease until the piston rod of the ejection cylinder reaches the set position and closes the flow valve.

[0011] In one embodiment, the ejection cylinder is connected to the ejection plate, the piston rod of the ejection cylinder pushes the ejection plate to move, the detection component is arranged on the ejection plate, and the detection component is a position sensor.

[0012] In one embodiment, the pipeline assembly further includes a pressure regulating pipeline, one end of which is connected to the oil inlet pipeline, the other end of which is connected to the oil return pipeline, and is communicated with the flow valve for regulating the pressure of the ejection cylinder movement positioning hydraulic circuit.

[0013] In one embodiment, the pressure regulating pipeline is provided with a first one-way valve, the sealing end of the first one-way valve is connected to the return oil pipeline, and the movable end of the first one-way valve is connected to the flow valve. When the opening of the flow valve gradually decreases and causes the pressure of the return oil pipeline to be greater than the pressure of the oil inlet pipeline, the first one-way valve opens the sealing end and inputs the return oil pipeline pressure to the flow valve.

[0014] In one embodiment, the pressure regulating pipeline is also provided with a second one-way valve, the sealing end of the second one-way valve is connected to the oil inlet pipeline, the movable end of the second one-way valve is connected to the flow valve and the movable end of the first one-way valve, and the second one-way valve is used to limit the pressure of the return oil pipeline from entering the oil inlet pipeline.

[0015] In one embodiment, the oil return pipeline is provided with an overflow valve, one end of the overflow valve is connected to the reversing valve, and the other end is connected to the oil tank, and the overflow valve is used to limit the maximum pressure of the oil return pipeline.

[0016] In one embodiment, the reversing valve is a three-position four-way electromagnetic reversing valve or a three-position four-way electro-hydraulic reversing valve.

[0017] The technical solution of the utility model controls the reversing adjustment of the reversing valve through a control component, so that the oil inlet pipeline can be selectively connected to one of the rod chamber or the rodless chamber of the ejection oil cylinder, and the oil return pipeline is connected to the other cavity, so that the piston rod of the ejection oil cylinder can be arbitrarily switched between the ejection state and the retraction state; when the detection component detects that the piston rod of the ejection oil cylinder is close to the set position, the control component controls the opening of the flow valve to gradually reduce, thereby adjusting the flow flowing into the flow valve through the return oil pipeline until the piston rod of the ejection oil cylinder reaches the set position and the flow valve is closed, thereby improving the accuracy of the ejection oil cylinder in ejecting the die casting to the preset position.

[0018] The utility model also provides a die-casting machine, comprising the ejection cylinder movement positioning hydraulic circuit as described in any of the above embodiments.

[0019] A die-casting machine according to the technical solution of the utility model comprises the ejector cylinder movement positioning hydraulic circuit provided by any one of the embodiments of the above-mentioned aspect, and therefore has the same technical effect, that is, the reversing adjustment of the reversing valve is controlled by the control component, so that the oil inlet pipeline can be selectively connected to one of the rod chamber or the rodless chamber of the ejector cylinder, and the oil return pipeline is connected to the other cavity, so that the piston rod of the ejector cylinder can be arbitrarily switched between the ejection state and the retraction state; when the detection component detects that the piston rod of the ejector cylinder is close to the set position, the control component controls the opening of the flow valve to gradually reduce, thereby adjusting the flow flowing into the flow valve through the return oil pipeline, until the piston rod of the ejector cylinder reaches the set position and the flow valve is closed, thereby improving the accuracy of the ejector cylinder in ejecting the die-casting to the preset position. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0021] Figure 1 It is a schematic diagram of the principle of an embodiment of the hydraulic circuit for positioning the ejection cylinder according to the utility model.

[0022] Description of Figure Numbers:

[0023] 10- ejection cylinder, 11- rod chamber, 12- rodless chamber, 13- ejection plate, 14- first port, 15- second port, 20- pipeline assembly, 21- oil inlet pipeline, 22- oil return pipeline, 23- pressure regulating pipeline, 30- reversing valve, 31- second oil outlet, 32- third oil outlet, 33- fourth oil outlet, 34- fifth oil outlet, 40- flow valve, 41- first oil inlet, 42- first oil outlet, 43- second oil inlet, 50- oil tank, 60- first check valve, 70- overflow valve, 80- second check valve, 90- detection assembly.

[0024] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

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

[0027] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. 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 utility model.

[0028] During the ejection process, the existing ejection cylinder fails to eject the die-casting to the preset position due to inaccurate positioning of the ejection cylinder, resulting in the inability of the retrieval system to clamp the die-casting or the clamping area of ​​the die-casting is too small, causing the die-casting to fall during the retrieval process. Therefore, the present application provides a hydraulic circuit for positioning the movement of an ejector cylinder, which controls the reversing adjustment of the reversing valve 30 through the control component, so that the oil inlet pipeline 21 can be selectively connected to one of the rod chamber 11 or the rodless chamber 12 of the ejector cylinder 10, and the oil return pipeline 22 is connected to the other cavity, so that the piston rod of the ejector cylinder 10 can be switched between the ejection state and the retraction state at will; when the detection component 90 detects that the piston rod of the ejector cylinder 10 is close to the set position, the control component controls the opening of the flow valve 40 to gradually reduce, thereby adjusting the flow flowing into the flow valve 40 through the oil return pipeline 22, until the piston rod of the ejector cylinder 10 reaches the set position and the flow valve 40 is closed, thereby improving the accuracy of the ejector cylinder 10 in ejecting the die casting to the preset position.

[0029] like Figure 1 As shown, the ejector cylinder motion positioning hydraulic circuit of the present application includes an ejector cylinder 10, including a rod chamber 11 and a rodless chamber 12;

[0030] The pipeline assembly 20 includes an oil inlet pipeline 21 and an oil return pipeline 22;

[0031] The reversing valve 30 is connected to the ejection cylinder 10 through the oil inlet pipeline 21 and the oil return pipeline 22, and is used to realize the reversing adjustment of the oil inlet pipeline 21 or the oil return pipeline 22, so that one of the oil inlet pipeline 21 and the oil return pipeline 22 is selectively connected to the rod chamber 11 of the ejection cylinder 10, and the other is connected to the rodless chamber 12 of the ejection cylinder 10;

[0032] A flow valve 40 is provided in the oil return pipeline 22 and is used to adjust the flow of the oil return pipeline 22. One end of the flow valve 40 is connected to the reversing valve 30, and the other end is connected to the oil tank 50; and

[0033] A detection component 90, used to detect the piston rod position of the ejection cylinder 10;

[0034] The control component is electrically connected to the detection component 90 and is used to control the opening of the flow valve 40. When the detection component 90 detects that the piston rod of the ejection cylinder 10 is close to the set position, the control component controls the opening of the flow valve 40 to gradually decrease until the piston rod of the ejection cylinder 10 reaches the set position and closes the flow valve 40.

[0035] Specifically, in the present embodiment, the ejection cylinder 10 includes a rod chamber 11 and a rodless chamber 12 which are not connected to each other. The piston rod is in the rod chamber 11 and is displaced according to the pressure difference between the rod chamber 11 and the rodless chamber 12. Both the rod chamber 11 and the rodless chamber 12 are used to store fluid, and the fluid can be set as hydraulic oil. The ejection cylinder 10 can also include a first port 14 and a second port 15, the first port 14 can be connected to the rodless chamber 12, and the second port 15 can be connected to the rod chamber 11. In order to realize the ejection and retraction actions of the piston rod of the ejection cylinder 10, the ejection cylinder 10 is connected to the oil inlet pipeline 21 and the oil return pipeline 22 respectively through the reversing valve 30. The reversing valve 30 can change the flow direction of the hydraulic oil in the oil inlet pipeline 21 by moving its own valve core, so that the oil inlet pipeline 21 can be connected to one of the first port 14 or the second port 15, and then the oil inlet pipeline 21 is connected to one of the cavities with the rod chamber 11 or the rodless chamber 12, so that the oil return pipeline 22 is correspondingly connected to the other cavity, thereby controlling the movement direction of the piston rod of the ejection cylinder 10. Specifically, when the ejection cylinder 10 needs the piston rod to eject, one end of the oil inlet line 21 can be connected to the hydraulic oil input source, and the end of the oil inlet line 21 away from the hydraulic oil input source is connected to the rodless chamber 12 through the first port 14, so that the hydraulic oil is transported to the rodless chamber 12, and the return oil line 22 is connected to the rod chamber 11 through the second port 15, so that the hydraulic oil is transported from the rod chamber 11 to the return oil line 22, and the pressure difference between the rodless chamber 12 and the rod chamber 11 drives the piston rod to eject from the ejection cylinder 10. Furthermore, when the ejection cylinder 10 needs to retract the piston rod, one end of the oil inlet line 21 can be connected to the hydraulic oil input source, and the end of the oil inlet line 21 away from the hydraulic oil input source is connected to the rod chamber 11 through the second port 15, so that the hydraulic oil is transported to the rod chamber 11, and the oil return line 22 is connected to the rodless chamber 12 through the first port 14, so that the hydraulic oil is transported from the rodless chamber 12 to the oil return line 22, thereby driving the piston rod to be retracted into the ejection cylinder 10.

[0036] In this embodiment, in order to improve the accuracy of the ejection displacement of the piston rod of the ejection oil cylinder 10, a flow valve 40 is provided in the oil return line 22. When the piston rod of the ejection oil cylinder 10 is ejected, the flow rate of the hydraulic oil flowing into the oil return line 22 is adjusted by controlling the opening of the flow valve 40, thereby controlling the hydraulic oil pressure in the rod chamber 11, thereby controlling the ejection displacement of the piston rod of the ejection oil cylinder 10, thereby achieving the position accuracy of different piston rod displacements, and further improving the accuracy of the ejection displacement of the piston rod of the ejection oil cylinder 10. In order to further improve the accuracy of the ejection displacement of the piston rod of the ejection oil cylinder 10, a detection component 90 is provided to detect the position of the piston rod of the ejection oil cylinder 10, and a control component is provided to be electrically connected to the detection component 90, the reversing valve 30 and the flow valve 40 respectively, so that the control component can control the opening of the flow valve 40 according to the electrical signal of the piston rod position detected by the detection component 90. Specifically, when the detection component 90 detects that the piston rod is displaced to a position close to the set position, the piston rod begins to enter the buffer stroke, and the control component controls the opening of the flow valve 40 to gradually decrease, thereby slowly reducing the hydraulic oil in the rod chamber 11, and then causing the piston rod to slowly displace to the set position. When the piston rod is displaced to the set position, the valve of the flow valve 40 is completely closed.

[0037] like Figure 1 As shown, in this embodiment, the ejection cylinder 10 is connected to the ejection plate 13, the piston rod of the ejection cylinder 10 pushes the ejection plate 13 to move, and the detection component 90 is arranged on the ejection plate 13, and the detection component 90 is a position sensor.

[0038] In this embodiment, in order to further improve the accuracy of the ejection displacement of the piston rod of the ejection oil cylinder 10, the ejection oil cylinder 10 is connected to the ejection plate 13, and the piston rod of the ejection oil cylinder 10 can push the ejection plate 13 to move relative to the ejection oil cylinder 10, and the detection component 90 is arranged on the ejection plate 13. Therefore, the control component receives the electrical signal fed back by the detection component 90 measuring the moving distance of the ejection plate 13, thereby controlling the opening of the flow valve 40 according to the electrical signal, and then indirectly controlling the moving distance of the ejection plate 13, thereby further improving the accuracy of the ejection displacement of the piston rod of the ejection oil cylinder 10.

[0039] like Figure 1 As shown, in this embodiment, the pipeline assembly 20 also includes a pressure regulating pipeline 23, one end of the pressure regulating pipeline 23 is connected to the oil inlet pipeline 21, the other end is connected to the oil return pipeline 22, and is connected to the flow valve 40, for adjusting the pressure of the ejection cylinder movement positioning hydraulic circuit.

[0040] In this embodiment, in order to better adjust the pressure of the hydraulic circuit for the movement and positioning of the ejector oil cylinder, the pipeline assembly 20 is provided to further include a pressure regulating pipeline 23, the pressure regulating pipeline 23 is connected to the flow valve 40, one end of the pressure regulating pipeline 23 is connected to the oil inlet pipeline 21, and the other end of the pressure regulating pipeline 23 is connected to the oil return pipeline 22, so that the pressure regulating pipeline 23 can adjust the pressure of the hydraulic circuit for the movement and positioning of the ejector oil cylinder. Specifically, assuming that the rod chamber 11 and the rodless chamber 12 of the ejector oil cylinder 10 are both without pressure, at this time, the present application can deliver the fluid to the flow valve 40 through the oil inlet pipeline 21 through the pressure regulating pipeline 23, thereby providing the flow valve 40 with a system pressure for control.

[0041] like Figure 1 As shown, in this embodiment, the pressure regulating pipeline 23 is provided with a first one-way valve 60, the sealing end of the first one-way valve 60 is connected to the return oil pipeline 22, and the movable end of the first one-way valve 60 is connected to the flow valve 40. When the opening of the flow valve 40 gradually decreases and causes the pressure of the return oil pipeline 22 to be greater than the pressure of the oil inlet pipeline 21, the first one-way valve 60 opens the sealing end and inputs the pressure of the return oil pipeline 22 to the flow valve 40.

[0042] In this embodiment, the first one-way valve 60 can be electrically connected to the control component, and the sealing end of the first one-way valve 60 is connected to the return oil pipeline 22 through the pressure regulating pipeline 23. In the process of the ejection cylinder 10 ejecting the ejection plate 13 through the piston rod, one end of the inlet pipeline 21 can be connected to the hydraulic oil input source, and the end of the inlet pipeline 21 away from the hydraulic oil input source is connected to the rodless chamber 12 through the first port 14, and the return oil pipeline 22 is connected to the rod chamber 11 through the second port 15; when the flow valve 40 remains closed or opens a very small opening, the area of ​​the rod chamber 11 is smaller than the area of ​​the rodless chamber 12, so that the pressure of the return oil pipeline 22 is greater than the pressure of the inlet oil pipeline 21. In order to solve the problem that the pressure of the return oil pipeline 22 is higher than the pressure of the inlet oil pipeline 21, the control component needs to control the opening of the first one-way valve 60, and the return oil pipeline 22 inputs the high pressure in the rod chamber 11 to the flow valve 40 through the first one-way valve 60, thereby adjusting the pressure of the hydraulic circuit of the ejection cylinder movement positioning.

[0043] like Figure 1 As shown, in this embodiment, the pressure regulating pipeline 23 is also provided with a second one-way valve 80, the sealing end of the second one-way valve 80 is connected to the oil inlet pipeline 21, the movable end of the second one-way valve 80 is connected to the flow valve 40 and the movable end of the first one-way valve 60, and the second one-way valve 80 is used to limit the pressure of the return oil pipeline 22 from entering the oil inlet pipeline 21.

[0044] In this embodiment, the second one-way valve 80 can be electrically connected to the control assembly, the sealing end of the second one-way valve 80 is connected to the oil inlet pipeline 21 through the pressure regulating pipeline 23, the movable end of the second one-way valve 80 is respectively connected to the movable ends of the flow valve 40 and the first one-way valve 60, and the second one-way valve 80 is used to prevent the fluid in the return oil pipeline 22 from flowing back into the oil inlet pipeline 21. In order to solve the problem that both the rod chamber 11 and the rodless chamber 12 of the ejection cylinder 10 have no pressure, the control assembly can open the second one-way valve 80 at this time, so that the oil inlet pipeline 21 transfers the fluid to the flow valve 40 through the pressure regulating pipeline 23 and the second one-way valve 80, thereby providing the flow valve 40 with a system pressure for control.

[0045] like Figure 1 As shown, in this embodiment, the oil return pipeline 22 is provided with a relief valve 70 , one end of the relief valve 70 is connected to the reversing valve 30 , and the other end is connected to the oil tank 50 . The relief valve 70 is used to limit the maximum pressure of the oil return pipeline 22 .

[0046] In this embodiment, the overflow valve 70 can be electrically connected to the control component, one end of the overflow valve 70 is connected to the reversing valve 30 through the return oil pipeline 22, and the other end of the overflow valve 70 is connected to the oil tank 50 through a pipeline. The overflow valve 70 is set as a safety valve for the return oil pipeline 22, thereby limiting the maximum pressure of the return oil pipeline 22. Specifically, when the pressure of the return oil pipeline 22 is too high, the control component opens the overflow valve 70, so that the excess fluid in the return oil pipeline 22 flows back to the oil tank 50, thereby limiting the maximum pressure of the return oil pipeline 22, thereby ensuring the stable operation and safety of the present application.

[0047] like Figure 1 As shown, in this embodiment, the reversing valve 30 is a three-position four-way electromagnetic reversing valve or a three-position four-way electro-hydraulic reversing valve.

[0048] In this embodiment, in order to further improve the accuracy of the ejection displacement of the piston rod of the ejection cylinder 10 and enable the control component to better control the switching direction of the reversing valve 30, the reversing valve 30 can be set as a three-position four-way electromagnetic reversing valve or a three-position four-way electro-hydraulic reversing valve.

[0049] like Figure 1As shown, in this embodiment, the flow valve 40 is provided with a first oil inlet 41, a first oil outlet 42, and a second oil inlet 43 which are interconnected, the reversing valve 30 is connected to the first oil inlet 41 through the oil return line 22, the first oil outlet 42 is connected to the oil tank 50, the first check valve 60 is connected to the second oil inlet 43 through the pressure regulating line 23, one end of the second check valve 80 is connected to the second oil inlet 43, and the other end of the second check valve 80 is connected to the oil inlet line 21 through the pressure regulating line 23, so as to better realize that the fluid can flow in through different oil inlets of the flow valve 40. The control component opens the first check valve 60 and / or the second check valve 80 to cooperate with the second oil inlet 43, thereby increasing the hydraulic pressure on the flow valve 40, thereby improving the accuracy of flow control and regulation of the flow valve 40.

[0050] like Figure 1 As shown, in this embodiment, the reversing valve 30 is provided with a second oil outlet 31 and a third oil outlet 32, the second oil outlet 31 is connected to the second port 15 through the oil inlet pipeline 21, the first port 14 is connected to the third oil outlet 32 ​​through the oil return pipeline 22, and the other end of the third oil outlet 32 ​​is connected to the first oil inlet 41 through the oil return pipeline 22;

[0051] Alternatively, the reversing valve 30 is provided with a fourth oil outlet 33 and a fifth oil outlet 34, the fourth oil outlet 33 is connected to the first port 14 through the oil inlet pipeline 21, the second port 15 is connected to the fifth oil outlet 34 through the oil return pipeline 22, and the other end of the fifth oil outlet 34 is connected to the first oil inlet 41 through the oil return pipeline 22.

[0052] In this embodiment, the reversing valve 30 is provided with a second oil outlet 31, a third oil outlet 32, a fourth oil outlet 33 and a fifth oil outlet 34, so that the reversing valve 30 can better realize that the fluid in the oil inlet pipeline 21 and the oil return pipeline 22 can flow in and out through different oil outlets, so that the reversing valve 30 is convenient to cooperate with the ejection oil cylinder 10 to realize the ejection action and retraction action of the piston rod. The second oil outlet 31 and the third oil outlet 32 ​​are not connected to each other, and the fourth oil outlet 33 and the fifth oil outlet 34 are not connected to each other.

[0053] In this embodiment, when the ejection cylinder 10 needs to retract the piston rod, one end of the oil inlet line 21 can be connected to the hydraulic oil input source, and the end of the oil inlet line 21 away from the hydraulic oil input source is connected to the second port 15 through the second oil outlet 31, so that the hydraulic oil is delivered to the rod chamber 11, and the first port 14 is connected to the third oil outlet 32 ​​through the return oil line 22, so that the hydraulic oil is delivered from the rodless chamber 12 to the return oil line 22 through the reversing valve 30, thereby driving the piston rod to be retracted into the oil cylinder. When the ejection cylinder 10 needs the piston rod to eject, one end of the oil inlet line 21 can be connected to the hydraulic oil input source, and the end of the oil inlet line 21 away from the hydraulic oil input source is connected to the first port 14 through the fourth oil outlet 33, so that the hydraulic oil is delivered to the rodless chamber 12, and the second port 15 is connected to the fifth oil outlet 34 through the return oil line 22, so that the hydraulic oil is delivered from the rod chamber 11 to the return oil line 22, thereby driving the piston rod to be ejected from the cylinder.

[0054] The embodiment of the present application provides a die-casting machine, which includes a hydraulic circuit for positioning the ejector oil cylinder. The specific structure of the hydraulic circuit for positioning the ejector oil cylinder is referred to the above embodiment. Since the die-casting machine adopts all the technical solutions of all the above embodiments, it is at least provided with all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0055] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A hydraulic circuit for positioning a ejector cylinder, characterized in that: include: The ejector cylinder includes a rod chamber and a rodless chamber; Pipeline components, including oil inlet pipeline and oil return pipeline; a reversing valve, connected to the ejection oil cylinder through the oil inlet pipeline and the oil return pipeline, for realizing the reversing adjustment of the oil inlet pipeline or the oil return pipeline, so that one of the oil inlet pipeline and the oil return pipeline is selectively connected to the rod chamber of the ejection oil cylinder, and the other is connected to the rodless chamber of the ejection oil cylinder; A flow valve is provided in the oil return pipeline and is used to adjust the flow of the oil return pipeline, one end of the flow valve is connected to the reversing valve, and the other end is connected to the oil tank; as well as A detection component, used for detecting the position of the piston rod of the ejection cylinder; A control component is electrically connected to the detection component and is used to control the opening of the flow valve. When the detection component detects that the piston rod of the ejection cylinder is close to a set position, the control component controls the opening of the flow valve to gradually decrease until the piston rod of the ejection cylinder reaches the set position and closes the flow valve.

2. The ejector cylinder movement positioning hydraulic circuit according to claim 1, characterized in that: The ejection oil cylinder is connected to the ejection plate, and the piston rod of the ejection oil cylinder pushes the ejection plate to move. The detection component is arranged on the ejection plate, and the detection component is a position sensor.

3. The ejector cylinder motion positioning hydraulic circuit according to claim 1, characterized in that: The pipeline assembly also includes a pressure regulating pipeline, one end of which is connected to the oil inlet pipeline, the other end of which is connected to the oil return pipeline, and is communicated with the flow valve for regulating the pressure of the ejection cylinder movement positioning hydraulic circuit.

4. The ejector cylinder movement positioning hydraulic circuit according to claim 3, characterized in that: The pressure regulating pipeline is provided with a first one-way valve, the sealing end of the first one-way valve is connected to the return oil pipeline, and the movable end of the first one-way valve is connected to the flow valve. When the opening of the flow valve gradually decreases and causes the pressure of the return oil pipeline to be greater than the pressure of the oil inlet pipeline, the first one-way valve opens the sealing end and inputs the return oil pipeline pressure to the flow valve.

5. The ejector cylinder movement positioning hydraulic circuit according to claim 4, characterized in that: The pressure regulating pipeline is also provided with a second one-way valve, the sealing end of the second one-way valve is connected to the oil inlet pipeline, the movable end of the second one-way valve is connected to the flow valve and the movable end of the first one-way valve, and the second one-way valve is used to limit the pressure of the return oil pipeline from entering the oil inlet pipeline.

6. The ejector cylinder movement positioning hydraulic circuit according to claim 3, characterized in that: The oil return pipeline is provided with an overflow valve, one end of the overflow valve is connected to the reversing valve, and the other end is connected to the oil tank. The overflow valve is used to limit the maximum pressure of the oil return pipeline.

7. The ejector cylinder movement positioning hydraulic circuit according to any one of claims 1 to 6, characterized in that: The reversing valve is a three-position four-way electromagnetic reversing valve or a three-position four-way electro-hydraulic reversing valve.

8. A die casting machine, characterized in that: It comprises the ejection cylinder movement positioning hydraulic circuit as described in any one of claims 1 to 7.

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