Injection system suitable for multiple injection modes

Abstract

The invention discloses an injection system suitable for multiple injection modes. The injection system comprises an air source, a first energy accumulator, a second energy accumulator, a valve module and an injection oil cylinder. The air source is used for supplying air to the first energy accumulator and the second energy accumulator, and the first energy accumulator and the second energy accumulator are both connected with a rodless cavity of the injection oil cylinder through the valve module. The first energy accumulator is suitable for supplying oil to a rodless cavity of the injection oil cylinder in the low-speed injection process and the high-speed injection process, and the second energy accumulator is suitable for pressurizing the injection oil cylinder in the pressurizing injection process. The first energy accumulator is suitable for supplying oil to a rodless cavity of the injection oil cylinder in the pushing process that the semi-solid metal moves to the intersection, and the second energy accumulator is suitable for controlling the speed of the injection oil cylinder in the filling process of the semi-solid metal. The injection control system has the beneficial effect that injection control under the two scenes of liquid pressure casting and semi-solid pressure casting is achieved by arranging one hydraulic control loop.

Description

Technical Field

[0001] The present application relates to the technical field of die-casting machines, and in particular to an injection system suitable for a multi-injection mode. Background Art

[0002] Die casting of metal products includes liquid die casting and semi-solid die casting. For liquid die casting, the raw materials are in liquid state before die casting. For example, aluminum alloy, during injection, the aluminum alloy liquid is in slow injection before reaching the intersection, and turns to fast injection after reaching the intersection. At this time, it is in the process of filling the mold cavity, and the required force and speed are relatively large. For semi-solid die casting, in the process of pushing the semi-solid metal in the feed barrel before reaching the intersection, the required injection speed is faster to avoid cooling of the semi-solid metal; when the filling process of the mold is carried out after reaching the intersection, the required speed needs to be reduced.

[0003] From the above process, it can be seen that the injection process of hydraulic die casting and semi-solid die casting is exactly opposite, and the dynamic injection force required in the rapid injection stage of semi-solid die casting is much higher than that required in liquid die casting. Therefore, it is difficult for ordinary die casting machines used for liquid die casting to achieve semi-solid die casting process. Summary of the invention

[0004] One of the objects of the present application is to provide a shot-casting system suitable for a multi-shot method that can solve at least one of the defects in the above-mentioned background technology.

[0005] In order to achieve at least one of the above-mentioned purposes, the technical solution adopted in the present application is: a shot system suitable for multiple shot modes, comprising 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 oil cylinder during slow injection and fast injection, and the second accumulator is suitable for pressurizing the injection oil cylinder during pressurized injection; when semi-solid die-casting is performed, the first accumulator is suitable for supplying oil to the rodless chamber of the injection oil cylinder during the pushing process of the semi-solid metal moving toward the intersection, and the second accumulator is suitable for speed control of the injection oil 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 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.

[0007] Preferably, the valve module also includes a control valve V3, and the rod chamber of the injection cylinder and the oil tank are connected via the control valve V3; in the slow injection process, the fast injection process or the pushing process, a linkage-controlled A-bridge structure is formed between the control valve V1 and the control valve V3; in the boost 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 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 air 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.

[0009] Preferably, the valve module also 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, so that during the boosting injection process or the filling process, the boosting pressure or the injection speed of the injection cylinder can be controlled by adjusting the opening of the control valve V2.

[0010] Preferably, the valve module also 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, so that during the boosting injection process or the filling process, the boosting pressure or the injection speed of the injection cylinder can be controlled by adjusting the opening of the control valve V4.

[0011] Preferably, 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; so that 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 to link and control the boosting pressure or injection speed of the injection cylinder.

[0012] Preferably, 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.

[0013] Preferably, the gas source is a nitrogen cylinder group.

[0014] Compared with the prior art, the beneficial effects of this application are:

[0015] By setting up a set of hydraulic control circuits to realize injection control in both liquid die casting and semi-solid die casting scenarios, the application scope of the injection system can be increased while the complexity of the control circuit can be effectively reduced, thereby reducing the design cost of the injection system. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0017] In the figure: nitrogen cylinder group 1, first accumulator 2, second accumulator 3, injection cylinder 4, cartridge valve 5. DETAILED DESCRIPTION

[0018] Below, the present application is further described in conjunction with specific implementation methods. It should be noted that in the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily being directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may 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 directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of narrating the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and cannot be understood as limiting the specific scope of protection of the present application.

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

[0021] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be connected, detachably connected, or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0023] The terms "including" and "having" and any variations thereof in the specification and claims of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0024] One of the preferred embodiments of the present application is as follows: Figure 1 As shown, an injection system suitable for multiple injection modes includes an air source, a first accumulator 2, a second accumulator 3, a valve module, and an injection oil 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 a stable oil supply operation. The first accumulator 2 and the second accumulator 3 are both connected to the rodless chamber of the injection oil cylinder 4 through the valve module.

[0025] When liquid die casting is performed, the first accumulator 2 can supply oil to the rodless cavity of the injection oil cylinder 4 during slow injection and fast injection, and the second accumulator 3 can pressurize the injection oil cylinder 4 during pressurized injection. When semi-solid die casting is performed, the first accumulator 2 can supply oil to the rodless cavity of the injection oil cylinder 4 during the pushing process of the semi-solid metal moving toward the intersection, and the second accumulator 3 can control the speed of the injection oil cylinder 4 during the filling process of the semi-solid metal.

[0026] It is understandable 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 pushing 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 pushing 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. If the existing ordinary die casting machine, that is, the die casting machine used for liquid die casting, is directly used for the die casting production of semi-solid products, there may be a problem of insufficient dynamic injection force.

[0027] Specifically, during the pushing stage of semi-solid die casting, since the semi-solid metal is already at the critical point of solidification and the semi-solid metal does not need to consider the air entrainment phenomenon of the liquid metal, the injection speed of the semi-solid metal in the pushing stage is faster than the slow injection speed of the liquid die casting. At the same time, during the filling stage of semi-solid die casting, due to the characteristics of the semi-solid metal, the injection force required for its filling is much greater than the injection force required for the liquid die casting in the fast injection stage. Therefore, if you want to perform semi-solid die casting through an ordinary die casting machine, you need to increase the cylinder diameter of the injection cylinder 4, or use a larger tonnage die casting machine for production, which will cause a waste of machine efficiency.

[0028] In the present embodiment, the rapid injection stage of liquid die casting can be made to correspond to the pushing stage of semi-solid die casting, and the pressurization stage of liquid die casting can be made to correspond to the filling stage of semi-fixed die casting. It should be noted that the injection speed of liquid die casting in the rapid injection stage is generally designed and selected according to 10m / s, while the injection speed of semi-solid die casting in the pushing stage is generally 2m / s. Therefore, the rapid injection stage of liquid die casting can well meet the requirements of the pushing stage of semi-solid die casting, and the injection speed matching of the pushing stage can be adjusted by the opening of the valve module. At the same time, the injection force required in the pressurization 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-mentioned injection sequence of semi-solid die casting by 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 in the slow injection stage and the fast injection stage of liquid die casting, as well as the pushing stage of semi-solid die casting. The injection force generated by the second accumulator 3 is relatively large, and is mainly used in the pressurization stage of liquid die casting and the filling stage of semi-solid die casting. If only one accumulator is used, the accumulator needs to be designed according to the maximum injection force, maximum capacity and maximum injection speed, which will increase the design cost of the accumulator, and a single accumulator is not convenient for pressure control at different stages. 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 the relationship between the injection speed v1 in the slow injection stage, the injection speed v2 in the fast injection stage, and the injection speed v3 in the pushing stage is: v1<v3<v2. When performing the above three injection stages, the opening of the control valve module can be used to control the oil supply from the first accumulator 2 to the rodless chamber of the injection cylinder 4, thereby realizing the injection speed control of different injection stages. During the pressurized injection stage, since the liquid metal has completed the filling of the mold cavity, it is only necessary to control the cavity pressure at this time; and for the filling stage, it is necessary to control the injection speed of the semi-solid metal to ensure that the semi-solid metal quickly completes the filling of the mold cavity. That is, for liquid die casting, the control loop of the pressurized injection stage is the pressure loop; for semi-solid die casting, the control loop of the filling stage is the speed loop.

[0031] In this embodiment, Figure 1 As 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 chamber of the injection cylinder 4 through the control valve V1, and the second accumulator 3 can be connected to the rodless chamber of the injection cylinder 4 through the cartridge valve 5. When a slow injection process, a fast injection process or a pushing process is performed, the cartridge valve 5 is in a closed state. At this time, it is only necessary to adjust the opening of the control valve V1 according to the corresponding injection stage, and then control the amount of oil delivered to the rodless chamber of the injection cylinder 4 by the first accumulator 2 to realize injection speed control. When a boost injection process or a filling process is performed, the control valve V1 is in a closed state and the cartridge valve 5 is in an open state; at this time, the second accumulator 3 can deliver oil to the rodless chamber of the injection cylinder 4 through the cartridge valve 5.

[0032] It is understandable that the cartridge valve 5 itself does not have the ability to adjust the opening degree autonomously, but it can be seen from the above content that the oil supply of the second accumulator 3 needs to be controlled during the boost injection stage and the filling stage, so as to achieve the corresponding pressure loop or speed loop control. There are many specific implementation methods for controlling the oil supply of the second accumulator 3. For the sake of easy understanding, four specific examples will be used for detailed description.

[0033] Example 1: Figure 1 As shown, the valve module also includes a control valve V3, and the rod chamber of the injection oil cylinder 4 is connected to the oil tank through the control valve V3. In the slow injection process, the fast injection process or the pushing process, the control valve V1 and the control valve V3 form a linkage control A bridge structure; in the boost injection process or the filling process, the control valve V3 and the cartridge valve 5 form a B bridge structure.

[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 hydraulic resistances for driving the load, and both of the hydraulic resistances are variable hydraulic resistances. That is, when performing a slow injection process, a fast injection process or a material pushing process, the driving control of the injection cylinder 4 can be regarded as a load, and the opening control of the control valve V1 and the control valve V3 can be regarded as variable hydraulic resistances in the input and output directions, respectively, and then the injection speed control of the injection cylinder 4 can be realized 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 to increase the pressure of the rod chamber of the injection cylinder 4 to suppress the overshoot of the injection speed.

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

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

[0037] When the filling process is carried out, 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 reduced, 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 in the filling stage or the pressurization injection stage.

[0039] It should be known that, during the boosting and injection stage, the boosting pressure of the injection cylinder 4 can be monitored by a pressure sensor, and the monitored data can be 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 can be 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 here in detail.

[0040] Example 2: Figure 1 As shown, the second accumulator 3 is a piston 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 gas 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, and the annular chamber inlet of the second accumulator 3 is connected to the outlet of the first accumulator 2 through the control valve V2, and the annular chamber outlet of the second accumulator 3 is connected to the oil tank. Therefore, during the pressurization injection process or the filling process, a C-bridge structure is formed between the control valve V2 and the annular chamber outlet of the second accumulator 3.

[0041] It should be known that the C-bridge structure is also called a C-type half-bridge structure. The C-bridge structure is characterized by having two fluid resistances for driving the load, the fluid resistance in the output direction is fixed, and the fluid resistance in the input direction is variable. That is, in the boost injection process or the filling process, the driving control of the second accumulator 3 is used as the load, the outlet of the annular cavity of the second accumulator 3 connected to the oil tank can be regarded as a fixed fluid resistance, and the adjustable opening of the control valve V2 can be regarded as a variable fluid resistance.

[0042] When performing the boost injection process or the filling process, if it is necessary to reduce the injection speed of the injection cylinder 4 or reduce the boost pressure of the injection cylinder 4, that is, to reduce the pressure of 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 a 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 of 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 boost pressure of the injection cylinder 4, that is, to increase the pressure of 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 be reduced, and then the pressure of the annular chamber of the second accumulator 3 will be reduced.

[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 annular cavity outlet of the second accumulator 3 is directly connected to the oil tank, the outlet pressure of the annular cavity is small as the fixed liquid resistance of the C-bridge structure, which will result in the inlet of the annular cavity requiring a sufficiently large oil pressure to form a pressure difference with the outlet. In order to improve the dynamic control capability of the rod chamber of the second accumulator 3, a fixed damper that increases the return oil pressure can be installed between the annular cavity outlet of the second accumulator 3 and the oil tank.

[0044] Example 3:

[0045] like Figure 1 As shown, the second accumulator 3 still adopts a piston accumulator. The valve module also includes a control valve V4. The annular cavity inlet of the second accumulator 3 is directly connected to the outlet of the first accumulator 2, and the annular cavity outlet of the second accumulator 3 is connected to the oil tank through the control valve V4. Therefore, during the pressurization injection process or the filling process, a B bridge structure is formed between the control valve V4 and the annular cavity inlet of the second accumulator 3.

[0046] It should be known that the characteristics of the B-bridge structure are as described above; then in the pressurization injection process or the filling process of this example, the drive control of the second accumulator 3 acts as a load, the annular cavity of the second accumulator 3 is directly connected to the outlet of the first accumulator 2 and can be regarded as a fixed fluid resistance, and the adjustable opening of the control valve V4 can be regarded as a variable fluid resistance.

[0047] When performing the boost injection process or the filling process, if it is necessary to reduce the injection speed of the injection cylinder 4 or reduce the boost pressure of the injection cylinder 4, that is, to reduce the pressure of 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 V4 can be reduced, and when the amount of oil flowing from the first accumulator 2 to the annular chamber of the second accumulator 3 remains unchanged, the amount of oil flowing from the annular chamber of the second accumulator 3 to the oil tank through the control valve V4 is reduced, and then the pressure of 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 boost pressure of the injection cylinder 4, that is, to increase the pressure of 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 V4 can be increased. When the amount of oil flowing from the first accumulator 2 to the annular cavity of the second accumulator 3 remains unchanged, the amount of oil flowing from the annular cavity of the second accumulator 3 to the oil tank through the control valve V4 increases, and then the pressure in the annular cavity of the second accumulator 3 decreases.

[0048] Example 4:

[0049] like Figure 1 As shown, the second accumulator 3 still adopts a piston accumulator. The valve module also includes a control valve V2 and a control valve V4; the annular cavity inlet of the second accumulator 3 is connected to the outlet of the first accumulator 2 through the control valve V2, and the annular cavity outlet of the second accumulator 3 is connected to the oil tank through the control valve V4. Therefore, 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 to perform linkage control on the boosting pressure or injection speed of the injection cylinder 4.

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

[0051] When performing the 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 of 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 oil tank through the control valve V4 decreases, and then the pressure of 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 of 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 cavity of the second accumulator 3 through the control valve V2 is reduced, and the amount of oil flowing from the annular cavity of the second accumulator 3 to the oil tank through the control valve V4 is increased, and then the pressure in the annular cavity of the second accumulator 3 will be reduced.

[0052] It can be understood that the above four examples can all meet the requirements of this application, among which example 4 can be regarded as a 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 control valve V4 in example 4 has a non-cut-off fault, example 4 can be equivalent to example 2 or example 3 to perform 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 the drive control of the injection oil cylinder 4 is performed, the control valve V3 can form a hydraulic control bridge with the rodless cavity of the injection oil cylinder 4, and the annular cavity inlet and outlet of the second accumulator 3 can also form a hydraulic control bridge, so that 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 method of combining the above example 1 and example 4.

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

[0054] The above describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and the specification only describe the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the attached 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 intersection, and the second accumulator is suitable for speed control of the injection cylinder during the filling process of the semi-solid metal.

2. The injection molding system suitable for multi-injection method according to claim 1, characterized in that: 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.

3. The injection molding system suitable for a multi-injection method according to claim 2, 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.

4. The injection molding system suitable for a multi-injection method according to any one of claims 1 to 3, characterized in that: 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 air source, and 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.

5. The injection molding system suitable for multi-injection method according to claim 4, characterized in that: 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 pressurization and injection process or the filling process, the pressurization pressure or the injection speed of the injection cylinder is controlled by adjusting the opening of the control valve V2.

6. The injection molding system suitable for multi-injection method according to claim 4, characterized in that: 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 pressurization and injection process or the filling process, the pressurization pressure or the injection speed of the injection cylinder is controlled by adjusting the opening of the control valve V4.

7. The injection molding system suitable for a multi-injection method according to claim 4, characterized in that: The valve module further 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 to perform linkage control on the boosting pressure or the injection speed of the injection cylinder.

8. The injection molding system suitable for a 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.

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

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