A shot system applicable to multiple shot methods

Abstract

The present application discloses an injection system applicable to multiple injection methods, which includes an air source, a first accumulator, a second accumulator, a valve module, and an injection cylinder; the air source is used to supply air to the first accumulator and the second accumulator, and both the first accumulator and the second accumulator are connected to the rodless cavity of the injection cylinder through the valve module; the first accumulator is adapted to supply oil to the rodless cavity of the injection cylinder during the slow injection and the fast injection processes, and the second accumulator is adapted to boost the pressure of the injection cylinder during the boost injection process; the first accumulator is adapted to supply oil to the rodless cavity of the injection cylinder during the feeding process in which the semi-solid metal moves towards the intersection, and the second accumulator is adapted to control the speed of the injection cylinder during the filling process of the semi-solid metal. Beneficial effects of the present application: By setting up a set of hydraulic control circuits, the injection control in two scenarios of liquid die casting and semi-solid die casting can be realized.

Description

Technical Field

[0001] This application relates to the technical field of die-casting machines, and particularly to an injection system applicable to multiple injection methods. Background Art

[0002] The die-casting of metal products includes methods such as liquid die-casting and semi-solid die-casting. For liquid die-casting, that is, the raw material is in a liquid state before die-casting. Taking aluminum alloy as an example, during injection, the aluminum alloy liquid is in slow injection when it has not reached the sprue, and turns to fast injection after reaching the sprue. At this time, it is in the filling process of the mold cavity, and the required force and speed are relatively large. For semi-solid die-casting, during the pushing process of the semi-solid metal in the charging cylinder before it reaches the sprue, a relatively fast injection speed is required to prevent the semi-solid metal from cooling; when filling the mold after reaching the sprue, the required speed needs to be reduced.

[0003] From the above process, it can be seen that the injection processes of hydraulic die-casting and semi-solid die-casting are exactly opposite, and the dynamic injection force required in the fast injection stage of semi-solid die-casting is much higher than that required in liquid die-casting. Therefore, it is very difficult for a die-casting machine commonly used for liquid die-casting to implement the semi-solid die-casting process. Summary of the Invention

[0004] One of the purposes of this application is to provide an injection system applicable to multiple injection methods that can solve at least one defect in the above background art.

[0005] To achieve at least one of the above purposes, the technical solution adopted in this application is: an injection system applicable to multiple injection methods, including a gas source, a first accumulator, a second accumulator, a valve module, and an injection cylinder; the gas source is used to supply gas to the first accumulator and the second accumulator, and both the first accumulator and the second accumulator are connected to the rodless cavity of the injection cylinder through the valve module; when performing liquid die-casting, the first accumulator is adapted to supply oil to the rodless cavity of the injection cylinder during slow injection and fast injection processes, and the second accumulator is adapted to pressurize the injection cylinder during the boosting injection process; when performing semi-solid die-casting, the first accumulator is adapted to supply oil to the rodless cavity of the injection cylinder during the pushing process of the semi-solid metal moving towards the sprue, and the second accumulator is adapted to control the speed of the injection cylinder during the filling process of the semi-solid metal.

[0006] Preferably, the valve module includes a control valve V1 and a cartridge valve. The first accumulator is connected to the rodless cavity of the injection cylinder through the control valve V1, and the second accumulator is connected to the rodless cavity of the injection cylinder through the cartridge valve. The injection speed of the injection cylinder is controlled by adjusting the opening degree of the control valve V1. The cartridge valve is adapted to be in a closed state when the first accumulator is working, and the control valve V1 is adapted to be in a closed state when the second accumulator is working.

[0007] Preferably, the valve module further includes a control valve V3. The rodless cavity of the injection cylinder is connected to the oil tank through the control valve V3. During the slow injection process, the fast injection process or the feeding process, an A-bridge structure with interlocking control is formed between the control valve V1 and the control valve V3. During the boosting injection process or the filling process, a B-bridge structure is formed between the control valve V3 and the cartridge valve.

[0008] Preferably, the second accumulator adopts a piston-type accumulator, including a rodless cavity, an annular cavity and a rod cavity. The rodless cavity of the second accumulator is used to communicate with the gas source. The rod cavity of the second accumulator is connected to the rodless cavity of the injection cylinder through the cartridge valve, and the oil volume provided by the rod cavity of the second accumulator is greater than or equal to the oil volume required by the injection cylinder during the filling process.

[0009] Preferably, the valve module further includes a control valve V2. The inlet of the annular cavity of the second accumulator is connected to the outlet of the first accumulator through the control valve V2, and the outlet of the annular cavity of the second accumulator is connected to the oil tank, so that during the boosting injection process or the filling process, the boosting pressure or the injection speed of the injection cylinder is controlled by adjusting the opening degree of the control valve V2.

[0010] Preferably, the valve module further includes a control valve V4. The inlet of the annular cavity of the second accumulator communicates with the outlet of the first accumulator, and the outlet of the annular cavity of the second accumulator is connected to the oil tank through the control valve V4, so that during the boosting injection process or the filling process, the boosting pressure or the injection speed of the injection cylinder is controlled by adjusting the opening degree of the control valve V4.

[0011] Preferably, the valve module further includes a control valve V2 and a control valve V4. The inlet of the annular cavity of the second accumulator is connected to the outlet of the first accumulator through the control valve V2, and the outlet of the annular cavity of the second accumulator is connected to the oil tank through the control valve V4. So that during the boosting injection process or the filling process, an A-bridge structure with interlocking control of the boosting pressure or the injection speed of the injection cylinder is formed between the control valve V2 and the control valve V4.

[0012] Preferably, stroke switches are installed in the rodless chambers of the first accumulator and the second accumulator, so that the first accumulator and the second accumulator end energy storage by triggering the stroke switches during the energy storage process.

[0013] Preferably, the gas source adopts a nitrogen cylinder bank.

[0014] Compared with the prior art, the beneficial effects of the present application are as follows:

[0015] By setting up a set of hydraulic control circuits to achieve injection control in two scenarios of liquid die casting and semi-solid die casting, the applicable range of the injection system can be increased while effectively reducing the complexity of the control circuit, thereby reducing the design cost of the injection system. Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the overall hydraulic structure of the present application.

[0017] In the figure: nitrogen cylinder bank 1, first accumulator 2, second accumulator 3, injection cylinder 4, cartridge valve 5. Detailed Embodiments

[0018] Next, in combination with the specific embodiments, the present application will be further described. It should be noted that in the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

[0019] In the description of the present application, it should be noted that for the orientation terms, if there are terms such as "center", "transverse", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation and position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and should not be construed as limiting the specific protection scope of the present application.

[0020] It should be noted that the terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects and do not necessarily describe a specific order or sequence.

[0021] In this application, unless otherwise clearly defined and limited, terms such as "installed", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it can be a connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] In this application, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0023] The terms "comprising" and "having" in the description and claims of this application, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that comprises a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0024] One preferred embodiment of this application is, for example, Figure 1 As shown, a shot system applicable to multiple shot modes includes an air source, a first accumulator 2, a second accumulator 3, a valve module, and a shot cylinder 4. The air source can supply air to the first accumulator 2 or the second accumulator 3 so that the first accumulator 2 or the second accumulator 3 can perform stable oil supply work. Both the first accumulator 2 and the second accumulator 3 are connected to the rodless cavity of the shot cylinder 4 through the valve module.

[0025] When performing liquid die casting, the first accumulator 2 can supply oil to the rodless cavity of the injection cylinder 4 during the slow injection and fast injection processes, and the second accumulator 3 can boost the pressure of the injection cylinder 4 during the boosting injection process. When performing semi-solid die casting, the first accumulator 2 can supply oil to the rodless cavity of the injection cylinder 4 during the feeding process in which the semi-solid metal moves towards the sprue, and the second accumulator 3 can control the speed of the injection cylinder 4 during the filling process of the semi-solid metal.

[0026] It can be understood that the injection process of liquid die casting is divided into a slow injection stage and a fast injection stage, and the injection process of semi-solid die casting is divided into a feeding stage and a filling stage. In terms of the sequence of the injection process, the slow injection stage of hydraulic die casting corresponds to the feeding stage of semi-solid die casting, and the fast injection stage of liquid die casting corresponds to the filling stage of semi-solid die casting. When directly using an existing ordinary die casting machine, that is, the die casting machine used for liquid die casting, to produce semi-solid products by die casting, there may be a problem of insufficient dynamic injection force.

[0027] Specifically, when performing the feeding stage of semi-solid die casting, since the semi-solid metal has reached the critical point of solidification and the semi-solid metal does not need to consider the gas entrapment phenomenon of liquid metal, the injection speed of the semi-solid metal in the feeding stage is faster than the slow injection speed of liquid die casting. At the same time, when performing the filling stage of semi-solid die casting, due to the characteristics of the semi-solid metal, the injection force required for filling is much greater than the injection force required in the fast injection stage of liquid die casting. Therefore, if one wants to perform semi-solid die casting with an ordinary die casting machine, it is necessary to increase the cylinder diameter of the injection cylinder 4 or use a die casting machine with a larger tonnage for production, which will cause waste of machine efficiency.

[0028] In this embodiment, the fast injection stage of liquid die casting can be corresponded to the feeding stage of semi-solid die casting, and the boosting stage of liquid die casting can be corresponded to the filling stage of semi-solid die casting. It should be noted that the injection speed in the fast injection stage of liquid die casting is generally selected and designed according to 10 m / s, while the injection speed in the feeding stage of semi-solid die casting is generally 2 m / s. Therefore, the fast injection stage of liquid die casting can well meet the requirements of the feeding stage of semi-solid die casting, and the matching of the injection speed in the feeding stage can be adjusted by the opening degree of the valve module. At the same time, the injection force required in the boosting stage of liquid die casting is relatively large, and this injection force can well meet the injection force required in the filling stage of semi-solid die casting.

[0029] Based on the above injection sequence method for semi-solid die casting using an ordinary die casting machine, two accumulators are designed in this embodiment, namely the first accumulator 2 and the second accumulator 3. The injection force generated by the first accumulator 2 is relatively small and is mainly used for the slow injection stage and the fast injection stage of liquid die casting, as well as the material pushing stage of semi-solid die casting. The injection force generated by the second accumulator 3 is relatively large and is mainly used for the boosting stage of liquid die casting and the filling stage of semi-solid die casting. If only one accumulator is used, then this accumulator needs to be designed according to the maximum injection force, the maximum capacity, and the maximum injection speed, which will lead to an increase in the design cost of this accumulator, and it is not convenient to control the pressure in different stages with a single accumulator. In this embodiment, the first accumulator 2 only needs to be designed according to the speed requirement, and the second accumulator 3 only needs to be designed according to the injection force requirement.

[0030] It should be known that for the injection speeds v1 in the slow injection stage, v2 in the fast injection stage, and v3 in the material pushing stage, the magnitude relationship is: v1 < v3 < v2. Then, during the above three injection stages, the opening degree of the control valve module can be used to control the oil supply amount delivered by the first accumulator 2 to the rodless cavity of the injection cylinder 4, thereby realizing the control of the injection speed in different injection stages. During the boosting injection stage, since the liquid metal has completed the filling of the mold cavity, only the cavity pressure needs to be controlled at this time; for the filling stage, the injection speed of the semi-solid metal needs to be controlled to ensure that the semi-solid metal quickly fills the mold cavity. That is, for liquid die casting, the control loop in the boosting injection stage is the pressure loop; for semi-solid die casting, the control loop in the filling stage is the speed loop.

[0031] In this embodiment, as Figure 1 shown, the valve module capable of realizing the above basic functions mainly includes a control valve V1 and a cartridge valve 5. The first accumulator 2 can be connected to the rodless cavity of the injection cylinder 4 through the control valve V1, and the second accumulator 3 can be connected to the rodless cavity of the injection cylinder 4 through the cartridge valve 5. When performing the slow injection process, the fast injection process, or the material pushing process, the cartridge valve 5 is in the closed state. At this time, only the opening degree of the control valve V1 needs to be adjusted according to the corresponding injection stage, and then the oil volume delivered by the first accumulator 2 to the rodless cavity of the injection cylinder 4 is controlled to realize the injection speed control. When performing the boosting injection process or the filling process, the control valve V1 is in the closed state, and the cartridge valve 5 is in the open state; at this time, the second accumulator 3 can deliver oil to the rodless cavity of the injection cylinder 4 through the cartridge valve 5.

[0032] It can be understood that the cartridge valve 5 itself does not have the ability to autonomously adjust its opening degree. However, from the foregoing content, it can be seen that during the boosting injection stage and the filling stage, it is necessary to control the oil supply amount of the second accumulator 3 to achieve the corresponding pressure loop or speed loop control. There are various specific implementation methods for controlling the oil supply amount of the second accumulator 3. For the convenience of understanding, the following will be described in detail through four specific examples.

[0033] Example 1: As Figure 1 shown, the valve module further includes a control valve V3. The rod chamber of the injection cylinder 4 is connected to the fuel tank through the control valve V3. During the slow injection process, the fast injection process, or the pusher process, a linkage control A-bridge structure is formed between the control valve V1 and the control valve V3; during the boosting injection process or the filling process, a B-bridge structure is formed between the control valve V3 and the cartridge valve 5.

[0034] It should be known that the A-bridge structure is also called the A-type half-bridge structure. The characteristic of the A-bridge structure is that there are two liquid resistances for driving the load, and both liquid resistances are variable liquid resistances. That is, during the slow injection process, the fast injection process, or the pusher process, the drive control of the injection cylinder 4 can be regarded as the load. At this time, the opening degree controls of the control valve V1 and the control valve V3 can be regarded as variable liquid resistances in the input and output directions respectively. Furthermore, the injection speed control of the injection cylinder 4 can be achieved through the linkage control of the control valve V1 and the control valve V3; for example, when the injection speed of the injection cylinder 4 is overshot, the control valve V3 can reduce the opening degree to increase the pressure in the rod chamber of the injection cylinder 4 to suppress the overshoot of the injection speed.

[0035] At the same time, the B-bridge structure is also called the B-type half-bridge structure. The characteristic of the B-bridge structure is that there are two liquid resistances for driving the load. The liquid resistance in the input direction is a fixed liquid resistance, and the liquid resistance in the output direction is a variable liquid resistance. That is, during the boosting injection process or the filling process, the drive control of the injection cylinder 4 can be regarded as the load. The fixed opening degree of the cartridge valve 5 can be regarded as a fixed liquid resistance, and the adjustable opening degree of the control valve V3 can be regarded as a variable liquid resistance.

[0036] When the boosting injection process is carried out, the pressure control of the injection cylinder 4 is used as the target value. If the boosting pressure of the injection cylinder 4 is lower than the preset pressure, the opening degree of the control valve V3 will be increased, thereby reducing the pressure in the rod chamber to increase the pressure difference between the non-rod chamber and the rod chamber; if the boosting pressure of the injection cylinder 4 exceeds the preset pressure, the opening degree of the control valve V3 will be reduced, thereby increasing the pressure in the rod chamber to reduce the pressure difference between the non-rod chamber and the rod chamber.

[0037] During the filling process, the injection speed of the injection cylinder 4 is used as the target value. If the injection speed of the injection cylinder 4 is lower than the preset speed, the opening of the control valve V3 will be increased, thereby reducing the pressure in the rod chamber to increase the pressure difference between the rodless chamber and the rod chamber. If the injection speed of the injection cylinder 4 exceeds the preset pressure, the opening of the control valve V3 will be decreased, thereby increasing the pressure in the rod chamber to reduce the pressure difference between the rodless chamber and the rod chamber.

[0038] It should be noted that the minimum output pressure of the second accumulator 3 is greater than or equal to the maximum injection force required during the filling stage or the boosting injection stage.

[0039] It should be known that during the boosting injection stage, the boosting pressure of the injection cylinder 4 can be monitored by a pressure sensor, and the monitored data is used as the input of the pressure loop for real-time control. Similarly, during the filling stage, the injection speed of the injection cylinder 4 can be monitored by a speed sensor, and the monitored data is used as the input of the speed loop for real-time control. The openings of the control valve V1, the control valve V3, and the subsequent control valves V2 and V4 are all controlled by the controller according to the feedback of the speed loop or the pressure loop. The specific structure and working principle of the controller are well-known technologies to those skilled in the art, so they will not be elaborated in detail here.

[0040] Example 2: As Figure 1 shown, the second accumulator 3 adopts a piston-type accumulator, including a rodless chamber, an annular chamber, and a rod chamber; the rodless chamber of the second accumulator 3 is used to communicate with the air source, and the rod chamber of the second accumulator 3 is connected to the rodless chamber of the injection cylinder 4 through the cartridge valve 5. The valve module also includes a control valve V2. The inlet of the annular chamber of the second accumulator 3 is connected to the outlet of the first accumulator 2 through the control valve V2, and the outlet of the annular chamber of the second accumulator 3 is connected to the fuel tank. Thus, a C-bridge structure is formed between the control valve V2 and the outlet of the annular chamber of the second accumulator 3 during the boosting injection process or the filling process.

[0041] It should be known that the C-bridge structure is also called a C-type half-bridge structure. The characteristic of the C-bridge structure is that there are two liquid resistances for driving the load. The liquid resistance in the output direction is a fixed liquid resistance, and the liquid resistance in the input direction is a variable liquid resistance. That is, during the boosting injection process or the filling process, the drive control of the second accumulator 3 is used as the load. The connection of the outlet of the annular chamber of the second accumulator 3 to the fuel tank can be regarded as a fixed liquid resistance, and the adjustable opening of the control valve V2 can be regarded as a variable liquid resistance.

[0042] When performing the pressure boosting injection process or the filling process, if it is necessary to reduce the injection speed of the injection cylinder 4 or lower the boosting pressure of the injection cylinder 4, that is, to reduce the pressure in the rodless chamber of the injection cylinder 4, it is only necessary to reduce the pressure difference between the rod chamber and the annular chamber of the second accumulator 3. At this time, the opening of the control valve V2 can be increased. Since the control valve V1 is in the closed state at this time, the amount of oil flowing from the first accumulator 2 to the annular chamber of the second accumulator 3 through the control valve V2 will increase, and then the pressure in the annular chamber of the second accumulator 3 will increase. If it is necessary to increase the injection speed of the injection cylinder 4 or increase the boosting pressure of the injection cylinder 4, that is, to increase the pressure in the rodless chamber of the injection cylinder 4, it is only necessary to increase the pressure difference between the rod chamber and the annular chamber of the second accumulator 3. At this time, the opening of the control valve V2 can be reduced, and the amount of oil flowing from the first accumulator 2 to the annular chamber of the second accumulator 3 through the control valve V2 will decrease, and then the pressure in the annular chamber of the second accumulator 3 will decrease.

[0043] It should be noted that in order to ensure the smooth progress of the filling process, the amount of oil provided by the rod chamber of the second accumulator 3 is greater than or equal to the amount of oil required by the injection cylinder 4 during the filling process. At the same time, since the outlet of the annular chamber of the second accumulator 3 is directly connected to the fuel tank, the outlet pressure of the annular chamber is used as the value of the fixed hydraulic resistance of the C-bridge structure, which is relatively small. This will cause the inlet of the annular chamber to require a sufficiently large oil pressure to form a pressure difference with the outlet. In order to improve the dynamic control ability of the rod chamber of the second accumulator 3, a fixed damper for increasing the return oil pressure can be installed between the outlet of the annular chamber of the second accumulator 3 and the fuel tank.

[0044] Example 3:

[0045] As Figure 1 shown, the second accumulator 3 still uses a piston-type accumulator. The valve module further includes a control valve V4. The inlet of the annular chamber of the second accumulator 3 is directly communicated with the outlet of the first accumulator 2, and the outlet of the annular chamber of the second accumulator 3 is connected to the fuel tank through the control valve V4. Thus, during the pressure boosting injection process or the filling process, a B-bridge structure is formed between the control valve V4 and the inlet of the annular chamber of the second accumulator 3.

[0046] It should be known that the characteristics of the B-bridge structure are as described above. Then, during the pressure boosting injection process or the filling process of this example, the drive control of the second accumulator 3 is used as a load. The direct connection between the annular chamber of the second accumulator 3 and the outlet of the first accumulator 2 can be regarded as a fixed hydraulic resistance, and the adjustable opening of the control valve V4 can be regarded as a variable hydraulic resistance.

[0047] When performing the pressure boosting injection process or the filling process, if it is necessary to reduce the injection speed of the injection cylinder 4 or lower the boosting pressure of the injection cylinder 4, that is, to reduce the pressure in the rodless cavity of the injection cylinder 4, it is only necessary to reduce the pressure difference between the rod cavity and the annular cavity of the second accumulator 3. At this time, the opening degree of the control valve V4 can be reduced. Then, with the oil flow rate from the first accumulator 2 to the annular cavity of the second accumulator 3 remaining unchanged, the oil flow rate from the annular cavity of the second accumulator 3 to the fuel tank through the control valve V4 decreases, and thus the pressure in the annular cavity of the second accumulator 3 will increase. If it is necessary to increase the injection speed of the injection cylinder 4 or increase the boosting pressure of the injection cylinder 4, that is, to increase the pressure in the rodless cavity of the injection cylinder 4, it is only necessary to increase the pressure difference between the rod cavity and the annular cavity of the second accumulator 3. At this time, the opening degree of the control valve V4 can be increased. Then, with the oil flow rate from the first accumulator 2 to the annular cavity of the second accumulator 3 remaining unchanged, the oil flow rate from the annular cavity of the second accumulator 3 to the fuel tank through the control valve V4 increases, and thus the pressure in the annular cavity of the second accumulator 3 will decrease.

[0048] Example 4:

[0049] As Figure 1 shown, the second accumulator 3 still adopts a piston-type accumulator. The valve module further includes a control valve V2 and a control valve V4; the inlet of the annular cavity of the second accumulator 3 is connected to the outlet of the first accumulator 2 through the control valve V2, and the outlet of the annular cavity of the second accumulator 3 is connected to the fuel tank through the control valve V4. Thus, during the pressure boosting injection process or the filling process, an A-bridge structure for jointly controlling the boosting pressure or the injection speed of the injection cylinder 4 is formed between the control valve V2 and the control valve V4.

[0050] It can be understood that the characteristics of the A-bridge structure are as described above. Then, during the pressure boosting injection process or the filling process of this example, the drive control of the second accumulator 3 is regarded as a load, and the adjustable opening degrees of the control valve V2 and the control valve V4 can both be regarded as variable fluid resistances.

[0051] When performing the pressure boosting injection process or the filling process, if it is necessary to reduce the injection speed of the injection cylinder 4 or reduce the boosting pressure of the injection cylinder 4, that is, to reduce the pressure in the rodless chamber of the injection cylinder 4, it is only necessary to reduce the pressure difference between the rod chamber and the annular chamber of the second accumulator 3. At this time, the opening of the control valve V2 can be increased, and the opening of the control valve V4 can be reduced; then the amount of oil flowing from the first accumulator 2 to the annular chamber of the second accumulator 3 through the control valve V2 increases, and the amount of oil flowing from the annular chamber of the second accumulator 3 to the fuel tank through the control valve V4 decreases, and thus the pressure in the annular chamber of the second accumulator 3 will increase. If it is necessary to increase the injection speed of the injection cylinder 4 or increase the boosting pressure of the injection cylinder 4, that is, to increase the pressure in the rodless chamber of the injection cylinder 4, it is only necessary to increase the pressure difference between the rod chamber and the annular chamber of the second accumulator 3. At this time, the opening of the control valve V2 can be reduced, and the opening of the control valve V4 can be increased. The amount of oil flowing from the first accumulator 2 to the annular chamber of the second accumulator 3 through the control valve V2 decreases, and the amount of oil flowing from the annular chamber of the second accumulator 3 to the fuel tank through the control valve V4 increases, and thus the pressure in the annular chamber of the second accumulator 3 will decrease.

[0052] It can be understood that the above four examples can all meet the requirements of this application. Among them, Example 4 can be regarded as the combination of Example 2 and Example 3. That is, Example 4 can be regarded as a redundant setting of Example 2 or Example 3; if the control valve V2 or the control valve V4 in Example 4 has a non-cut-off failure, Example 4 can be equivalent to Example 2 or Example 3 for B-bridge or C-bridge control. Of course, Example 1 can also be used simultaneously with Example 2, Example 3 or Example 4. That is, when controlling the drive of the injection cylinder 4, the control valve V3 can form a hydraulic control bridge circuit with the rodless chamber of the injection cylinder 4, and at the same time, the inlet and outlet of the annular chamber of the second accumulator 3 can also form a hydraulic control bridge circuit. In this way, a double-bridge control loop can be formed for the entire injection system, thereby effectively improving the control accuracy, response speed and working stability of the injection system; therefore, in this embodiment, the oil supply control method for the second accumulator 3 preferably adopts the combination of the above Example 1 and Example 4.

[0053] In this embodiment, as Figure 1 shown, stroke switches are installed in the rodless chambers of the first accumulator 2 and the second accumulator 3, so that the first accumulator 2 and the second accumulator 3 do not need to set a target inflation pressure during the energy storage process, and only need to store the first accumulator 2 and the second accumulator 3 until the stroke switch is triggered to end the energy storage. At this time, both the first accumulator 2 and the second accumulator 3 are in the maximum energy storage state. There are various types of gas sources used when the first accumulator 2 and the second accumulator 3 supply oil. The nitrogen cylinder group 1 is often used. Nitrogen, as an inert gas, has good stability.

[0054] The basic principle, main features and advantages of the present application have been described above. Those skilled in the art should understand that the present application is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present application. Without departing from the spirit and scope of the present application, various changes and improvements will occur to the present application, and these changes and improvements all fall within the scope of the present application claimed. The scope of protection required by the present application is defined by the appended claims and their equivalents.

Claims

1. A shot injection system suitable for a multi-shot injection method, characterized in that: It includes an air source, a first accumulator, a second accumulator, a valve module and an injection oil cylinder; the air source is used to supply air to the first accumulator and the second accumulator, and the first accumulator and the second accumulator are both connected to the rodless chamber of the injection oil cylinder through the valve module; When liquid die casting is performed, the first accumulator is suitable for supplying oil to the rodless chamber of the injection cylinder during slow injection and fast injection, and the second accumulator is suitable for pressurizing the injection cylinder during pressurized injection; When semi-solid die casting is performed, the first accumulator is suitable for supplying oil to the rodless cavity of the injection cylinder during the pushing process of the semi-solid metal moving toward the runner gate, and the second accumulator is suitable for controlling the speed of the injection cylinder during the filling process of the semi-solid metal; The valve module includes a control valve V1 and a cartridge valve, the first accumulator is connected to the rodless chamber of the injection cylinder through the control valve V1, and the second accumulator is connected to the rodless chamber of the injection cylinder through the cartridge valve; The injection speed of the injection cylinder is controlled by adjusting the opening of the control valve V1; The cartridge valve is suitable for being in a closed state when the first accumulator is working, and the control valve V1 is suitable for being in a closed state when the second accumulator is working; The second accumulator is a piston accumulator, including a rodless chamber, an annular chamber and a rod chamber; The rodless chamber of the second accumulator is used to communicate with the gas source, the rod chamber of the second accumulator is connected to the rodless chamber of the injection cylinder through the cartridge valve, and the amount of oil provided by the rod chamber of the second accumulator is greater than or equal to the amount of oil required by the injection cylinder during the filling process; The valve module further includes a control valve V2, the annular cavity inlet of the second accumulator is connected to the outlet of the first accumulator through the control valve V2, and the annular cavity outlet of the second accumulator is connected to the oil tank; During the boosting and injection process or the filling process, the boosting pressure or the injection speed of the injection cylinder is controlled by adjusting the opening of the control valve V2; Alternatively, the valve module further includes a control valve V4, the annular cavity inlet of the second accumulator is connected to the outlet of the first accumulator, and the annular cavity outlet of the second accumulator is connected to the oil tank through the control valve V4; during the boosting injection process or the filling process, the boosting pressure or the injection speed of the injection cylinder is controlled by adjusting the opening of the control valve V4; Alternatively, the valve module also includes a control valve V2 and a control valve V4; the annular cavity inlet of the second accumulator is connected to the outlet of the first accumulator through the control valve V2, and the annular cavity outlet of the second accumulator is connected to the oil tank through the control valve V4; during the boosting and injection process or the filling process, an A-bridge structure is formed between the control valve V2 and the control valve V4 for linkage control of the boosting pressure or injection speed of the injection cylinder.

2. The injection molding system suitable for multi-injection method according to claim 1, characterized in that: The valve module further includes a control valve V3, through which the rod chamber of the injection oil cylinder and the oil tank are connected; In the slow injection process, the fast injection process or the material pushing process, the control valve V1 and the control valve V3 form an A-bridge structure of linkage control; During the pressurized injection process or the filling process, a B-bridge structure is formed between the control valve V3 and the cartridge valve.

3. The injection molding system suitable for multi-injection method according to claim 1, characterized in that: The rodless chambers of the first accumulator and the second accumulator are both installed with travel switches, so that the first accumulator and the second accumulator can terminate energy storage by triggering the travel switches during energy storage.

4. The injection molding system suitable for multi-injection method according to claim 1, characterized in that: The gas source adopts a nitrogen cylinder group.

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