A mold opening and pressurizing hydraulic system and injection molding machine

Abstract

The present invention relates to the technical field of injection molding devices, and provides a mold opening and boosting hydraulic system and an injection molding machine, wherein the hydraulic system comprises: a main oil cylinder, a boosting oil cylinder, a first cartridge valve, a first reversing valve, and a second reversing valve. Compared with the prior art, the advantages of the present invention are that the connection mode between the rod chamber and the rodless chamber of the main oil cylinder and the system oil port and the oil tank is switched by the first reversing valve, so as to realize the reciprocating motion of the piston rod of the main oil cylinder. At the same time, the first cartridge valve and the second reversing valve are used to perform a boosting operation on the boosting cylinder when the main oil cylinder performs the mold opening action, so as to increase the force applied by the main oil cylinder to the mold during the mold opening process, and ensure that the deep cavity mold can be opened smoothly.

Description

Technical Field

[0001] The invention relates to the technical field of injection molding devices, in particular to a mold opening and pressurizing hydraulic system and an injection molding machine. Background Art

[0002] For a standard three-plate injection molding machine, when producing deep-cavity parts, the adhesion between the deep-cavity parts and the mold may increase at the moment the mold is opened, making it difficult to separate the mold smoothly. This is usually because the deep-cavity structure causes the plastic parts to form a strong adsorption effect or mechanical lock with the mold surface during the cooling process, which increases the difficulty of removing the finished product. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a mold opening and pressurizing hydraulic system and an injection molding machine in view of the current status of the prior art.

[0004] The technical solution adopted by the present invention to solve the above technical problems is: to propose a mold opening boosting hydraulic system, which has at least a mold opening state and a mold locking state, and is characterized in that the hydraulic system includes:

[0005] Master cylinder;

[0006] A booster oil cylinder, the rod chamber of the booster oil cylinder is connected to the rod chamber of the master oil cylinder;

[0007] a first cartridge valve, wherein an oil outlet of the first cartridge valve is communicated with both the rod chamber of the master cylinder and the rod chamber of the boost cylinder;

[0008] a first reversing valve, wherein the first reversing valve is provided with a first working oil port and a second working oil port, wherein the first working oil port is communicated with the rodless chamber of the master cylinder, and the second working oil port is communicated with the oil inlet of the first cartridge valve;

[0009] A second reversing valve, wherein the second reversing valve is provided with a third working oil port, the third working oil port is communicated with the rodless chamber of the boosting oil cylinder, and the oil inlet of the second reversing valve is simultaneously communicated with the oil inlet of the first cartridge valve and the second working oil port;

[0010] When in the mold locking state, the first cartridge valve is in an open state, the system oil port is connected to the first working oil port, and the first working oil port supplies hydraulic oil to enter the rodless chamber of the main oil cylinder to provide a power source for the mold locking action of the main oil cylinder;

[0011] When in the mold opening state, the first cartridge valve is in a closed state, the system oil port is connected to the second working oil port, and the second working oil port supplies hydraulic oil to enter the rodless chamber of the booster cylinder through the oil inlet of the second reversing valve, so that the hydraulic oil in the rod chamber of the booster cylinder provides a power source for the mold opening action of the main cylinder.

[0012] The above-mentioned mold opening boosting hydraulic system also includes a one-way valve, the oil inlet of the one-way valve is connected to the rodless chamber of the boosting cylinder and the third working oil port at the same time, and the oil outlet of the one-way valve is connected to the rod chamber of the main cylinder, so as to supply the hydraulic oil of the system oil port to enter the rod chamber of the main cylinder after the boosting action of the boosting cylinder is completed.

[0013] In the above-mentioned mold opening boosting hydraulic system, the second reversing valve also includes a first oil outlet and a second oil outlet, the first oil outlet is connected to the rod chamber of the boosting cylinder, and the second oil outlet is connected to the system oil tank.

[0014] The above-mentioned mold opening boosting hydraulic system also includes a second cartridge valve and a third cartridge valve, the first reversing valve is provided with a third oil outlet, the oil outlet of the second cartridge valve is connected to the rodless chamber of the master cylinder, the oil inlet of the second cartridge valve is connected to the third oil outlet, the oil inlet of the third cartridge valve is connected to the third oil outlet, and the oil outlet of the third cartridge valve is connected to the system oil tank.

[0015] The above-mentioned mold opening boosting hydraulic system also includes a safety limit valve, the oil inlet of the safety limit valve is connected to the first working oil port, and the oil outlet of the safety limit valve is connected to the rodless chamber of the main oil cylinder.

[0016] The above-mentioned mold opening boosting hydraulic system also includes a third reversing valve connected to the first cartridge valve, and a fourth reversing valve connected to the third cartridge valve, and the oil outlets of the third reversing valve and the fourth reversing valve are both connected to the system oil tank.

[0017] In the above-mentioned mold opening and boosting hydraulic system, the first reversing valve is a three-position four-way reversing valve.

[0018] In the above-mentioned mold opening and boosting hydraulic system, the second reversing valve, the third reversing valve and the fourth reversing valve are all two-position four-way reversing valves.

[0019] In the above-mentioned mold opening boosting hydraulic system, the cross-sectional area of ​​the rodless chamber of the boosting oil cylinder is smaller than the cross-sectional area of ​​the rod chamber.

[0020] The present invention solves the above technical problem and further provides an injection molding machine, comprising the above mold opening and pressurizing hydraulic system.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] (1) The first reversing valve switches the connection mode between the rod chamber and the rodless chamber of the master cylinder and the system oil port and the oil tank, thereby realizing the reciprocating motion of the piston rod of the master cylinder. At the same time, the first cartridge valve and the second reversing valve are used to increase the pressure of the booster cylinder when the master cylinder performs the mold opening action, so as to increase the force applied by the master cylinder to the mold during the mold opening process, thereby ensuring that the deep cavity mold can be opened smoothly;

[0023] (2) By setting a one-way valve connected to the rodless chamber of the booster cylinder and the third working oil port at the same time, after the booster cylinder completes the boosting action, it can seamlessly switch to using the hydraulic oil provided by the system oil port to drive the main cylinder to open the mold, which not only improves the efficiency of the system, but also ensures the safety and stability of the fluid flow during the whole process;

[0024] (3) Through the coordinated work of the second cartridge valve and the third cartridge valve, the hydraulic system can automatically switch the flow direction of the hydraulic oil as needed during the clamping process to ensure that the piston rod of the main cylinder moves at an appropriate rate at different stages;

[0025] (4) By setting a one-way valve, it is mainly used for the pressure boosting and mold opening action control of the hydraulic system. After the pressure boosting cylinder completes the pressure boosting action, the function of the one-way valve is to enable the hydraulic oil in the system oil port to provide hydraulic oil to the rod chamber of the main cylinder through the one-way valve to support the main cylinder to perform subsequent mold opening actions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is an oil circuit diagram of a mold opening and boosting hydraulic system of the present invention;

[0027] Figure 2 This is the hydraulic oil flow path diagram in the clamping state;

[0028] Figure 3 It is the hydraulic oil flow path diagram when the mold is locked and the second cartridge valve is open;

[0029] Figure 4 This is the hydraulic oil flow path diagram when the pressurized mold is opened;

[0030] Figure 5 This is the hydraulic oil flow path diagram during rapid mold opening;

[0031] Figure 6 This is the hydraulic oil flow path diagram when the boost cylinder is reset.

[0032] In the figure, 1, main oil cylinder; 2, safety limit valve; 3, first cartridge valve; 4, booster oil cylinder; 5, one-way valve; 6, third reversing valve; 7, second reversing valve; 8, second cartridge valve; 9, first reversing valve; 10, third cartridge valve; 11, fourth reversing valve. DETAILED DESCRIPTION

[0033] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0034] like Figures 1 to 6 As shown, the present invention mainly describes in detail the specific structure of the hydraulic system and its application in the injection molding machine.

[0035] A mold opening and pressurizing hydraulic system has at least a mold opening state and a mold locking state. The hydraulic system comprises: a main oil cylinder 1, a pressurizing oil cylinder 4, a first cartridge valve 3, a first reversing valve 9, and a second reversing valve 7.

[0036] Specifically, the rod chamber of the boost cylinder 4 is connected to the rod chamber of the master cylinder 1;

[0037] The oil outlet of the first cartridge valve 3 is connected to the rod chamber of the master cylinder 1 and the rod chamber of the boost cylinder 4 at the same time;

[0038] The first reversing valve 9 is provided with a first working oil port and a second working oil port, the first working oil port is communicated with the rodless chamber of the master cylinder 1, and the second working oil port is communicated with the oil inlet of the first cartridge valve 3;

[0039] The second reversing valve 7 is provided with a third working oil port, the third working oil port is communicated with the rodless chamber of the boosting oil cylinder 4, and the oil inlet of the second reversing valve 7 is simultaneously communicated with the oil inlet of the first cartridge valve 3 and the second working oil port;

[0040] When in the mold locking state, the first cartridge valve 3 is in the open state, the system oil port is connected with the first working oil port, and the first working oil port supplies hydraulic oil to enter the rodless chamber of the main oil cylinder 1, providing a power source for the mold locking action of the main oil cylinder 1;

[0041] When in the mold opening state, the first cartridge valve 3 is in the closed state, the system oil port is connected to the second working oil port, and the second working oil port supplies hydraulic oil to enter the rodless chamber of the booster cylinder 4 through the oil inlet of the second reversing valve 7, so that the hydraulic oil in the rod chamber of the booster cylinder 4 provides the power source for the mold opening action of the main cylinder 1.

[0042] Reference Figure 2 As shown (the positions of the piston rod of the main oil cylinder 1 and the piston rod of the booster oil cylinder 4 in the figure show the positions after the mold is opened. In fact, the piston rod of the main oil cylinder 1 is in the correct position, and the piston rod of the booster oil cylinder 4 is actually located at Figure 2), in the mold locking state, the first reversing valve 9 connects the system oil port with the first working oil port, and connects the second working oil port with the oil tank; at this time, the first cartridge valve 3 is opened, and the hydraulic oil flows from the system oil port through the first working oil port into the rodless chamber of the main oil cylinder 1, while the hydraulic oil in the rod chamber of the main oil cylinder 1 flows back to the oil tank through the second working oil port. This process forms a force that pushes the piston rod of the main oil cylinder 1 to move Figure 2 The hydraulic circuit moving on the right side realizes the clamping action and completes the closing of the injection molding machine mold.

[0043] Reference Figure 4 (The positions of the piston rod of the main oil cylinder 1 and the piston rod of the boost oil cylinder 4 in the figure show the positions after the mold is opened. In fact, the piston rod of the main oil cylinder 1 and the piston rod of the boost oil cylinder 4 are both located at Figure 4 On the right side of the injection molding machine, when the injection molding machine needs to open the mold, the first cartridge valve 3 is closed, and the first reversing valve 9 switches its position so that the first working oil port is connected to the oil tank, and the second working oil port is connected to the system oil port. At this time, the hydraulic oil in the rodless chamber of the main oil cylinder 1 flows back to the oil tank through the first working oil port, and the system oil port guides the hydraulic oil through the second working oil port, through the oil inlet of the second reversing valve 7, and flows out from its third working oil port to enter the rodless chamber of the booster cylinder 4. And because this constitutes a force in the oil cylinder structure that causes the piston rod of the main oil cylinder 1 to move Figure 4 The hydraulic circuit moves on the left side, thereby completing the mold opening action under the action of the booster cylinder 4.

[0044] In this solution, the first reversing valve 9 is used to switch the connection mode between the rod chamber and the rodless chamber of the main cylinder 1 and the system oil port and the oil tank, thereby realizing the reciprocating motion of the piston rod of the main cylinder 1. At the same time, the first cartridge valve 3 and the second reversing valve 7 are used to perform a boosting operation through the boosting cylinder 4 when the main cylinder 1 performs the mold opening action, so as to increase the force applied by the main cylinder 1 to the mold during the mold opening process, thereby ensuring that the deep cavity mold can be opened smoothly.

[0045] Reference Figure 5 (The positions of the piston rod of the main oil cylinder 1 and the piston rod of the booster oil cylinder 4 in the figure show the positions after the mold is opened. In fact, the position of the booster oil cylinder 4 is correct, and the piston rod of the main oil cylinder 1 is Figure 5 On the right side of the main oil cylinder 1, it has not moved to the current position), this bill also includes a one-way valve 5, the oil inlet of the one-way valve 5 is connected with the rodless chamber of the booster cylinder 4 and the third working oil port at the same time, and the oil outlet of the one-way valve 5 is connected with the rod chamber of the main oil cylinder 1, so as to supply the hydraulic oil of the system oil port to enter the rod chamber of the main oil cylinder 1 after the boosting action of the booster cylinder 4 is completed.

[0046] The one-way valve 5 is an automatically operated valve designed to allow fluid (liquid or gas) to flow in only one direction to prevent reverse flow. When the fluid flows from the designated inlet to the outlet, the one-way valve 5 will open; once the fluid attempts to flow in the opposite direction, the one-way valve 5 will close to prevent reverse flow.

[0047] The one-way valve 5 added in this solution is mainly used for the pressure boosting and mold opening control of the hydraulic system. Specifically, after the pressure boosting cylinder 4 completes the pressure boosting action, the one-way valve 5 enables the hydraulic oil in the system oil port to provide hydraulic oil to the rod chamber of the main cylinder 1 through the one-way valve 5, so as to support the main cylinder 1 to perform the subsequent mold opening action.

[0048] To understand this process more clearly, please refer to Figure 4 The following are the detailed working steps:

[0049] Initial stage: In the initial stage of mold opening, the check valve 5 is in a closed state. The hydraulic oil provided by the system oil port does not pass through the check valve 5, but directly enters the rodless cavity of the booster cylinder 4 through the second working oil port and the second reversing valve 7. The rodless cavity of the booster cylinder 4 pushes the piston rod along Figure 4 It moves from right to left, thereby providing pressure for the hydraulic oil in the rod chamber of the booster cylinder 4, and then providing a power source for the movement of the piston rod of the main cylinder 1.

[0050] Boosting stage: Due to the presence of the piston rod of boosting cylinder 4, the effective area of ​​the rod chamber of boosting cylinder 4 is smaller than the area of ​​the rodless chamber. Therefore, when the system oil pressure remains unchanged, when the hydraulic oil flows from the rod chamber of boosting cylinder 4 with a smaller area into the rod chamber of master cylinder 1, a higher oil pressure can be provided for the movement of the piston rod of master cylinder 1, thus achieving a boosting effect on master cylinder 1.

[0051] After the boost is completed: When the piston rod of the boost cylinder 4 moves along Figure 4 As shown, after the boost cylinder 4 moves from right to left to the extreme position and the boosting action is completed, the boost cylinder 4 can no longer provide hydraulic oil to the rod chamber of the main cylinder 1. At this time, the one-way valve 5 is opened, because the piston rod of the boost cylinder 4 no longer moves, and the rodless chamber of the boost cylinder 4 can no longer accommodate more hydraulic oil, and the one-way valve 5 is in an open state. Therefore, the hydraulic oil provided by the system oil port flows into the rod chamber of the main cylinder 1 through the second working oil port and the second reversing valve 7, and then through the one-way valve 5, driving the piston rod of the main cylinder 1 to continue to move, thereby completing the subsequent mold opening action.

[0052] By introducing the one-way valve 5, the hydraulic system can seamlessly switch to using the hydraulic oil provided by the system oil port to drive the main cylinder 1 to open the mold after the booster cylinder 4 completes the boosting action. This design not only improves the efficiency of the system, but also ensures the safety and stability of the fluid flow throughout the process. The key function of the one-way valve 5 is that it can automatically adjust the switch state according to the direction of the fluid, ensuring that the fluid always flows along the predetermined path, avoiding various problems that may be caused by backflow.

[0053] The second reversing valve 7 further comprises a first oil outlet and a second oil outlet, the first oil outlet is communicated with the rod chamber of the boosting oil cylinder 4, and the second oil outlet is communicated with the system oil tank.

[0054] The first oil outlet of the second reversing valve 7 is connected to the rod chamber of the boosting oil cylinder 4, and is used to guide the hydraulic oil provided by the system oil port into the rod chamber of the boosting oil cylinder 4; the second oil outlet of the second reversing valve 7 is connected to the system oil tank, and is used to guide the hydraulic oil in the rodless chamber of the boosting oil cylinder 4 back to the tank. This design ensures that after the injection mold opening action is completed, the piston rod of the boosting oil cylinder 4 can be pushed to reset, ready for the next boosting action.

[0055] For a clearer understanding of the hydraulic system's operating mechanism, please refer to Figure 6 (The piston rods of the master cylinder 1 and booster cylinder 4 are in the correct position in the figure). The following are detailed steps:

[0056] Mold opening action is completed: After the main cylinder 1 completes the mold opening action, the piston rod of the main cylinder 1 and the piston rod of the booster cylinder 4 move to Figure 6 Status shown.

[0057] The first cartridge valve 3 is opened: At this time, the first cartridge valve 3 is opened, and the second reversing valve 7 is switched to the cross position and energized.

[0058] Hydraulic oil diversion: The hydraulic oil in the system oil port is diverted after passing through the second working oil port:

[0059] A portion of the hydraulic oil enters the rod chamber of the booster cylinder 4 through the first cartridge valve 3. Since the piston rod of the master cylinder 1 has moved to the limit position at this time, no more hydraulic oil can be injected into the rod chamber of the master cylinder 1, so this portion of the hydraulic oil will directly enter the rod chamber of the booster cylinder 4.

[0060] The other part of the hydraulic oil passes through the oil inlet of the second reversing valve 7. When the second reversing valve 7 is switched to the cross position and powered, its oil inlet is connected to the first oil outlet, and the third working oil outlet is connected to the second oil outlet. In this way, the hydraulic oil entering the oil inlet of the second reversing valve 7 flows from the first oil outlet into the rod chamber of the boosting cylinder 4. At the same time, the hydraulic oil in the rodless chamber of the boosting cylinder 4 flows back from the second oil outlet to the system oil tank through the third working oil port, forming a reset circuit for the boosting cylinder 4.

[0061] Booster cylinder 4 resets: During this process, the piston rod of the booster cylinder 4 moves from Figure 6 The position shown in FIG. 1 gradually moves to the limit position on the right side, completing the reset action. The reset action not only restores the initial state of the boost cylinder 4, but also makes full preparation for the next boost action.

[0062] Through the careful design of the above hydraulic system, the reversing valve, cartridge valve and other components work together to ensure that after the injection mold opening action is completed, the piston rod of the booster cylinder 4 can be reset efficiently and reliably. This not only improves the automation of the system, but also ensures that each boosting action can be performed in the best state, thereby improving the efficiency and stability of the entire injection molding process. In addition, reasonable hydraulic oil flow control also reduces energy waste and extends the service life of the equipment.

[0063] Reference Figure 3 (The positions of the piston rod of the main oil cylinder 1 and the piston rod of the booster oil cylinder 4 in the figure show the positions after the mold is opened. In fact, the piston rod of the main oil cylinder 1 has already moved to the Figure 3 The piston rod of booster cylinder 4 is located at Figure 3 On the right side of the main cylinder 1), the present scheme further comprises a second cartridge valve 8 and a third cartridge valve 10, the first reversing valve 9 is provided with a third oil outlet, the oil outlet of the second cartridge valve 8 is communicated with the rodless chamber of the main cylinder 1, the oil inlet of the second cartridge valve 8 is communicated with the third oil outlet, the oil inlet of the third cartridge valve 10 is communicated with the third oil outlet, and the oil outlet of the third cartridge valve 10 is communicated with the system oil tank.

[0064] The main function of the second cartridge valve 8 and the third cartridge valve 10 is to ensure that the hydraulic oil in the rod chamber of the master cylinder 1 does not flow back into the system oil tank during the clamping stage, but is introduced into the rodless chamber of the master cylinder 1, thereby increasing the moving speed of the piston rod of the master cylinder 1 and realizing rapid clamping of the injection mold.

[0065] For a clearer understanding of the hydraulic system's operating mechanism, please refer to Figure 3 , here are the detailed steps:

[0066] Slow mold locking stage: When the main oil cylinder 1 starts to perform the mold locking action, the second cartridge valve 8 is closed, and the first cartridge valve 3 and the third cartridge valve 10 are opened. At this time, the main oil cylinder 1 is in a slow mold locking state. The rodless chamber of the main oil cylinder 1 is connected to the system oil port through the first working oil port of the first reversing valve 9 and the oil inlet of the first reversing valve 9, and receives the hydraulic oil from the system oil port. The rod chamber of the main oil cylinder 1 is connected to the system oil tank through the first cartridge valve 3, the second working oil port of the second reversing valve 7, the third oil outlet and the third solenoid valve, so that the hydraulic oil flows back from the rod chamber to the system oil tank. In this state, the piston rod of the main oil cylinder 1 moves along Figure 3Move slowly from left to right to complete the initial clamping action.

[0067] Fast mold clamping stage: After a period of slow mold clamping, when the piston rod of the main oil cylinder 1 moves to the predetermined position, the control system will issue a command to open the second cartridge valve 8 and close the third cartridge valve 10. At this time, the hydraulic oil in the rod chamber of the main oil cylinder 1 no longer flows back to the system oil tank through the third solenoid valve, but flows directly into the rodless chamber of the main oil cylinder 1 through the second cartridge valve 8. This design increases the flow of hydraulic oil in the rodless chamber and significantly improves the moving speed of the piston rod of the main oil cylinder 1, thereby realizing the fast mold clamping process of the injection mold.

[0068] Hydraulic oil flow direction control: In the slow clamping stage, the hydraulic oil enters the rodless chamber of the main cylinder 1 from the system oil port, and flows back to the system oil tank from the rod chamber; in the fast clamping stage, the hydraulic oil directly enters the rodless chamber from the rod chamber through the second cartridge valve 8, avoiding unnecessary reflux paths and improving efficiency.

[0069] Speed ​​regulation mechanism: By controlling the switch states of the second cartridge valve 8 and the third cartridge valve 10, the system can flexibly adjust the moving speed of the piston rod of the main oil cylinder 1 to ensure that the clamping process is both stable and efficient.

[0070] Safety and reliability: Reasonable hydraulic oil flow control not only improves the response speed of the system, but also reduces energy loss and prolongs the service life of the equipment.

[0071] Through the coordinated work of the carefully designed second cartridge valve 8 and the third cartridge valve 10, the hydraulic system can automatically switch the flow direction of the hydraulic oil as needed during the mold clamping process to ensure that the piston rod of the main oil cylinder 1 moves at an appropriate rate at different stages. This design not only improves the mold clamping speed and shortens the production cycle, but also enhances the reliability and safety of the system, providing a solid guarantee for the efficient operation of the injection molding process.

[0072] This solution also includes a safety limit valve 2 , the oil inlet of the safety limit valve 2 is connected to the first working oil port, and the oil outlet of the safety limit valve 2 is connected to the rodless chamber of the main oil cylinder 1 .

[0073] Safety limit valve 2 is a critical safety device in the injection molding machine, specially designed to monitor the status of the injection molding machine safety door to ensure the personal safety of the operator. Its working principle and functions are as follows:

[0074] Normal operation mode: When the safety door is in the closed state, the safety limit valve 2 automatically switches to the open state, so that the rodless chamber of the main oil cylinder 1 is connected with the system oil port or the system oil tank. In this state, the hydraulic system can operate normally, and the main oil cylinder 1 and the booster oil cylinder 4 can perform actions such as mold locking and mold opening according to the predetermined program to ensure the smooth progress of the production process.

[0075] Safety protection mechanism: Once the safety door is opened or deviates from the closed position (i.e. not in the closed state), the safety limit valve 2 responds immediately and quickly switches to the closed state. At this time, all hydraulic connections between the main cylinder 1 and the booster cylinder 4 will be cut off, the hydraulic system stops supplying oil, and all moving parts are forced to stop working. This measure effectively prevents dangerous movements in unexpected situations and maximizes the safety of operators.

[0076] The present solution preferably further includes a third reversing valve 6 connected to the first cartridge valve 3, and a fourth reversing valve 11 connected to the third cartridge valve 10, and the oil outlets of the third reversing valve 6 and the fourth reversing valve 11 are both connected to the system oil tank. When the system is abnormal or the system oil pressure is too high, these two reversing valves are opened to guide part of the hydraulic oil to the system oil tank to ensure the stable operation of the system.

[0077] In addition, the first reversing valve 9 is preferably a three-position four-way reversing valve. The neutral function is used to cut off the connection between the main oil cylinder 1 and the booster oil cylinder 4 and the system oil circuit, so that the system oil port can provide hydraulic oil to other components of the injection molding machine (for example, the power component that drives the mold ejection mechanism to move) to ensure the normal operation of these components.

[0078] Preferably, the second reversing valve, the third reversing valve and the fourth reversing valve are all two-position four-way reversing valves.

[0079] A two-position four-way directional valve is a common hydraulic or pneumatic control element used to change the flow direction of a fluid (liquid or gas) to control the action of an actuator (such as a hydraulic cylinder or a pneumatic cylinder). It is called "two-position" because it has two working positions, and "four-way" means it has four interfaces for external connection. It is widely used in various industrial equipment and automation control systems to accurately control the action of hydraulic or pneumatic actuators. Selecting a two-position four-way solenoid valve as the second directional valve, the third directional valve, and the fourth directional valve is used to improve the control accuracy and stability of the entire hydraulic system.

[0080] Preferably, the cross-sectional area of ​​the rodless chamber of the booster cylinder is smaller than the cross-sectional area of ​​the rod chamber.

[0081] Generally speaking, due to the presence of the piston rod, the effective area of ​​the rod chamber of the boosting cylinder is smaller than the area of ​​the rodless chamber. Without considering the piston rod, directly setting the cross-sectional area of ​​the rodless chamber of the boosting cylinder to be smaller than the cross-sectional area of ​​the rod chamber is more conducive to the boosting operation of the boosting cylinder.

[0082] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention 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 indication will also change accordingly.

[0083] In addition, in the present invention, descriptions such as "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0084] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0085] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0086] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways without departing from the scope defined by the spirit of the present invention.

Claims

1. A mold opening boosting hydraulic system, having at least a mold opening state and a mold locking state, characterized in that: The hydraulic system comprises: Master cylinder; A booster oil cylinder, the rod chamber of the booster oil cylinder is connected to the rod chamber of the master oil cylinder; a first cartridge valve, wherein an oil outlet of the first cartridge valve is communicated with both the rod chamber of the master cylinder and the rod chamber of the boost cylinder; a first reversing valve, wherein the first reversing valve is provided with a first working oil port and a second working oil port, wherein the first working oil port is communicated with the rodless chamber of the master cylinder, and the second working oil port is communicated with the oil inlet of the first cartridge valve; A second reversing valve, wherein the second reversing valve is provided with a third working oil port, the third working oil port is communicated with the rodless chamber of the boosting oil cylinder, and the oil inlet of the second reversing valve is simultaneously communicated with the oil inlet of the first cartridge valve and the second working oil port; When in the mold locking state, the first cartridge valve is in an open state, the system oil port is connected to the first working oil port, and the first working oil port supplies hydraulic oil to enter the rodless chamber of the main oil cylinder to provide a power source for the mold locking action of the main oil cylinder; When in the mold opening state, the first cartridge valve is in a closed state, the system oil port is connected with the second working oil port, and the second working oil port supplies hydraulic oil to enter the rodless chamber of the boosting cylinder through the oil inlet of the second reversing valve, so that the hydraulic oil in the rod chamber of the boosting cylinder provides a power source for the mold opening action of the main cylinder; it also includes a one-way valve, the oil inlet of the one-way valve is connected with the rodless chamber of the boosting cylinder and the third working oil port at the same time, and the oil outlet of the one-way valve is connected with the rod chamber of the main cylinder, so as to supply the hydraulic oil of the system oil port to enter the rod chamber of the main cylinder after the boosting action of the boosting cylinder is completed.

2. A mold opening boosting hydraulic system as claimed in claim 1, characterized in that: The second reversing valve further includes a first oil outlet and a second oil outlet, the first oil outlet is communicated with the rod chamber of the boosting oil cylinder, and the second oil outlet is communicated with the system oil tank.

3. A mold opening boosting hydraulic system as claimed in claim 1, characterized in that: It also includes a second cartridge valve and a third cartridge valve, the first reversing valve is provided with a third oil outlet, the oil outlet of the second cartridge valve is connected to the rodless chamber of the master cylinder, the oil inlet of the second cartridge valve is connected to the third oil outlet, the oil inlet of the third cartridge valve is connected to the third oil outlet, and the oil outlet of the third cartridge valve is connected to the system oil tank.

4. A mold opening boosting hydraulic system as claimed in claim 1, characterized in that: It also includes a safety limit valve, the oil inlet of the safety limit valve is connected to the first working oil port, and the oil outlet of the safety limit valve is connected to the rodless chamber of the main oil cylinder.

5. A mold opening boosting hydraulic system as claimed in claim 3, characterized in that: It also includes a third reversing valve communicated with the first cartridge valve, and a fourth reversing valve communicated with the third cartridge valve, and the oil outlets of the third reversing valve and the fourth reversing valve are both communicated with the system oil tank.

6. A mold opening boosting hydraulic system as claimed in claim 1, characterized in that: The first reversing valve is a three-position four-way reversing valve.

7. A mold opening boosting hydraulic system as claimed in claim 5, characterized in that: The second reversing valve, the third reversing valve and the fourth reversing valve are all two-position four-way reversing valves.

8. A mold opening boosting hydraulic system as claimed in claim 1, characterized in that: The cross-sectional area of ​​the rodless chamber of the booster cylinder is smaller than the cross-sectional area of ​​the rod chamber.

9. An injection molding machine, characterized in that: It comprises a mold opening boosting hydraulic system as claimed in any one of claims 1 to 8.

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