Pressurizing structure of die-casting machine

Abstract

The utility model relates to the technical field of die-casting machine pressurization, in particular to a pressurization structure of a die-casting machine. According to the scheme, the pressurizing structure of the die-casting machine comprises an injection valve plate, a pressurizing piston rod is arranged in the middle of the injection valve plate, the pressurizing piston rod comprises an upper rod body and a lower rod body, a plurality of round holes are formed in the position, close to the end, of the upper rod body in a surrounding mode, rework can be reduced, single-time pressurizing efficiency can be improved, and cost is reduced. And the pressure around the pressurizing piston rod can be reduced, and deviation of the pressurizing piston rod is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of die-casting machine pressure boosting, in particular to a die-casting machine pressure boosting structure. Background Art

[0002] The die casting machine uses the injection cylinder as an accumulator to hydraulically inject metal into the mold cavity of the mold to form a die casting. During the process of metal liquid forming, a reaction force will be applied to the injection cylinder. Generally, it is necessary to increase the pressure at the rear end of the injection cylinder (i.e., supercharging) at the end of the high-speed section of the injection to ensure that there is enough casting pressure to make the metal liquid form under a certain pressure and improve the quality of the die casting. The injection system of the die casting machine is the core component of the die casting machine, and the supercharging cylinder is one of the important actuators of the system. Supercharging can increase the injection and pressure of the die casting machine to obtain a more uniform and dense blank or part. Supercharging can improve the density and mechanical properties of the casting, improve the strength and hardness of the material, and improve the surface quality of the die casting. At the same time, the structural performance of supercharging plays a decisive role in the casting pressure, injection speed, supercharging pressure and time in the die casting process. In practice, when the fast shot is about to end, the pressure of the shot cylinder piston chamber will rise sharply. When the shot cylinder piston chamber pressure reaches the set pressure or when the shot switch rod reaches the set position, the hydraulic oil in the booster accumulator is quickly released, and the oil in the booster rod chamber (i.e., oil chamber) of the booster cylinder returns to the oil tank, pushing the booster piston forward quickly. This process uses the area ratio of the booster cylinder piston and the piston rod to achieve the amplification of the shot cylinder force. The pressure of the booster cylinder piston chamber needs to be dynamically controlled and adjusted in real time. Therefore, a good booster structure plays a decisive role in the performance of the die-casting machine.

[0003] With the gradual promotion of large-scale one-piece die-casting machines, the types of one-piece die-casting products are increasing, and the casting structure is becoming increasingly complex, which has higher requirements for the mechanical properties and air tightness of the castings. The traditional open-loop boost control directly applies the pressure in the boost accumulator to the injection cylinder. The casting pressure is often high at first and then low, which is not conducive to the stability of the mechanical properties of the die-casting, and is easy to cause pressure shock, which is not conducive to the long-term use of the mold, and even causes flash on the die-casting. In addition, when using a boost accumulator to adjust the casting pressure of the injection cylinder, it is necessary to change the nitrogen pressure in the nitrogen bottle in the boost accumulator, and then adjust the pressure of the hydraulic oil in the rodless chamber of the injection cylinder, but this method cannot accurately and stably control the boost process of the injection cylinder.

[0004] The traditional booster cylinder uses a booster piston rod that is directly embedded in the injection valve plate, or a separate booster cylinder body is made, and the booster piston rod is embedded in the booster cylinder body. In the case of machining errors in the injection valve plate or the booster cylinder body, this structure can only choose to increase the diameter of the booster piston rod, which cannot avoid the negative impact of machining (high rework costs for the booster cylinder body and the injection valve plate).

[0005] In the traditional boosting structure, during the boosting process, the boosting piston rod compresses a large volume of hydraulic oil, resulting in a long pressure building time.

[0006] In the conventional supercharging structure, during the supercharging process, the pressure directly acts on the surroundings of the supercharging piston rod, and the deviation of the supercharging piston rod cannot be avoided.

[0007] Existing patents provide some solutions, such as patent JP5654327B2, which provides a die-casting machine and a boost control method for the die-casting machine, which can control the pressure with high precision in the boost step, so as to manufacture high-quality casting products. In the die-casting machine, when the molten metal is injected by the forward movement of the injection plunger to fill the inside of the cavity in the closed mold, an electric servo motor is used as a driving source in the low-speed injection step, and a hydraulic drive source is used as a driving source in the high-speed injection step adjacent to the low-speed injection step. When the boost step is performed after the high-speed injection step, the drive of the electric servo motor in the high-speed injection step is controlled so that the boost is increased at an early stage. Therefore, the pressure applied to the casting molded product that begins to solidify and shrink in the mold can be increased. However, the patent still has many problems in achieving internal pressure oil control and assembly design control costs.

[0008] For example, patent US20080185119A1 provides a die-casting machine that uses an electric servo motor as a driving source to inject / fill molten metal into the mold cavity of the mold through an injection sleeve. The molten metal in the injection sleeve is injected / filled into the cavity by an injection component. Between the stage where the molten metal has not yet reached the mold gate and the stage where the molten metal begins to pass through the mold gate, the speed of the injection component is controlled to accelerate with a smooth speed characteristic curve without a broken line characteristic. Therefore, a higher injection speed can be achieved quickly and smoothly. However, the patent has insufficient single-shot boost efficiency and the high pressure around the piston rod can easily cause the piston rod to deviate. The applicant believes that there is still a lot of room for improvement. Utility Model Content

[0009] The utility model provides a boosting structure which can reduce rework, improve single boosting efficiency, reduce pressure around a boosting piston rod, and avoid deviation of the boosting piston rod.

[0010] The technical solution provided by the utility model to achieve the above technical purpose is: a die-casting machine boosting structure, including a pressure-injection valve plate, a boosting piston rod is arranged in the middle of the pressure-injection valve plate, and the boosting piston rod includes an upper rod body and a lower rod body. The upper rod body is surrounded by a plurality of circular holes near the end.

[0011] Furthermore, during the rapid injection process, the booster piston rod receives the pressure oil from the rapid accumulator, and the pressure oil further flows into the upper rod body through the lower rod body. The circular hole provided on the upper rod body enables the pressure oil to further flow into the surrounding rodless cavity. As the booster piston rod continues to push forward, the circular hole is in complete contact with the inner wall of the injection valve plate, so that the pressure oil is completely enclosed in the rodless cavity.

[0012] In the utility model, a rodless cavity is opened on the outer side of the upper rod body, and the rodless cavity is arranged on the outer side of the circular hole.

[0013] Furthermore, during the boosting process, as the boosting piston rod moves, the rodless chamber is separated from the circular hole. At this time, the pressure of the pressure oil in the rodless chamber is approximately equal to the system pressure, and as the boosting piston rod continues to move forward, the volume of the pressure oil compressed by the boosting piston rod is only the volume of the pressure oil in the rodless chamber. This structural design avoids the problem that during the boosting process of the traditional boosting structure, the piston rod compresses a large volume of pressure oil, resulting in a long pressure building time. Through the design of the rodless chamber and the circular hole, the efficiency of pressure oil building is further improved and the problem of boosting piston rod deviation caused by the large volume of pressure oil is prevented.

[0014] In the utility model, a first cavity is opened in the center of the lower rod body, and the input end of the first cavity is connected to a boosting valve plate.

[0015] Furthermore, a booster cylinder sleeve is installed on the outer side of the lower rod body, and the booster valve plate is fixedly connected to the injection valve plate by bolts, thereby limiting the position of the booster piston rod. At the same time, the booster cylinder sleeve provides a displaceable stroke of the booster piston rod on the one hand, and on the other hand, the gap between the booster valve plate and the booster piston rod is filled by setting the booster cylinder sleeve. The booster cylinder sleeve also plays the role of a sealing sleeve, thereby preventing the pressure oil from flowing out when passing through the connection between the booster piston rod and the booster valve plate, thereby preventing the internal and external pressures from failing to meet the standards.

[0016] In the utility model, a pressure-boosting flange is sleeved on the outer side of the lower rod body, and a pressure-boosting cylinder sleeve is arranged below the pressure-boosting flange.

[0017] Furthermore, the boost flange is also mounted on the outside of the boost piston rod to increase the tightness of the connection between the boost piston rod and the injection valve plate. Furthermore, when a processing error occurs inside the boost valve plate, only the dimensions of the boost flange and the outside of the boost cylinder sleeve need to be adjusted to ensure the tightness of the connection between the boost valve plate and the boost piston rod. By simply reworking the boost flange and the boost cylinder sleeve, the need to rework the boost piston rod or the boost valve plate is avoided, reducing the cost requirements for manufacturing the structure. The maintenance cost of the boost structure is also reduced through modular design.

[0018] In the utility model, the boost flange is arranged inside the injection valve plate, and the end of the lower rod body is provided with a base extending outward, and the base is installed in cooperation with the boost cylinder sleeve.

[0019] Furthermore, the base extending outward from the lower rod body is installed in cooperation with the inner wall of the booster cylinder sleeve, and the stroke of the entire booster piston rod can be controlled by controlling the length of the booster cylinder sleeve and the thickness of the base.

[0020] In the utility model, the end of the lower rod body is arranged outside the injection valve plate, and the end of the injection valve plate is connected to the boosting valve plate.

[0021] In the utility model, a gap of at most 0.05 mm is provided between the injection valve plate and the upper end of the booster piston rod.

[0022] Furthermore, at the connection between the upper rod body and the inner wall of the injection valve plate, an annular groove is opened on the inner wall of the injection valve plate, and the depth of the annular groove is at most 0.05 mm. This design can improve the phenomenon of the booster piston rod getting stuck, and avoid the booster piston rod being frequently displaced for a long time, resulting in wall wear and then causing the booster piston rod body to shift.

[0023] Furthermore, as a preferred solution, after the injection is completed, the pressurization stage begins, the pressurization inlet switch valve is opened, the nitrogen in the nitrogen bottle is filled into the rodless cavity of the gas-liquid booster, the piston rod of the gas-liquid booster is pushed downward, and the hydraulic oil flows into the rodless cavity of the injection cylinder through the pressurization inlet switch valve to achieve pressurization. When the pressurization outlet switch valve is opened, the hydraulic oil in the annular cavity of the gas-liquid booster can also flow into the rodless cavity of the injection cylinder through the pressurization outlet switch valve. At this time, the pressure of the hydraulic oil flowing into the rodless cavity of the injection cylinder through the pressurization outlet switch valve can be controlled by the servo valve, and the servo valve 9 itself can control the injection speed of the injection cylinder, thereby realizing that one servo valve can control both the pressure and speed of the injection cylinder, and realize double closed-loop control.

[0024] Compared with the prior art, the utility model has the following significant technical effects: as the booster piston rod continues to move forward, the volume of the pressure oil compressed by the booster piston rod is only the volume of the pressure oil in the rodless chamber. This structural design avoids the problem that the traditional booster structure compresses a large volume of pressure oil during the boosting process, resulting in a long pressure building time. Through the design of the rodless chamber and the circular hole, the efficiency of pressure oil pressure building is further improved and the problem of the booster piston rod being offset due to the large volume of pressure oil is also prevented. By designing the booster flange and the booster cylinder sleeve to reduce the annular groove with a depth of at most 0.05mm, the phenomenon of the booster piston rod being stuck can be improved, and the booster piston rod can be prevented from being frequently displaced for a long time, resulting in wall wear and thus causing the booster piston rod body to be offset. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a cross-sectional structural schematic diagram of a die-casting machine boosting structure involved in the utility model;

[0026] Figure 2 for Figure 1 The enlarged structural diagram at A in the middle;

[0027] Figure 3 for Figure 1 The enlarged structural diagram at B in the middle;

[0028] Figure 4 for Figure 1 Enlarged structural diagram at point C in the middle.

[0029] Explanation of the reference numerals: 1 - injection valve plate; 2 - booster piston rod; 21 - upper rod body; 22 - lower rod body; 221 - first cavity; 23 - circular hole; 24 - rodless cavity; 3 - booster flange; 4 - booster cylinder sleeve; 5 - booster valve plate. DETAILED DESCRIPTION

[0030] Embodiment 1:

[0031] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the technical solution provided by the utility model to achieve the above technical purpose is: a die-casting machine boosting structure, including a shot valve plate 1, a boosting piston rod 2 is arranged in the middle of the shot valve plate 1, and the boosting piston rod 2 includes an upper rod body 21 and a lower rod body 22, and a plurality of circular holes 23 are arranged around the upper rod body 21 near the end.

[0032] Furthermore, during the fast injection process, the booster piston rod 2 receives the pressure oil from the fast accumulator, and the pressure oil further flows into the upper rod body 21 through the lower rod body 22. The circular hole 23 provided on the upper rod body 21 allows the pressure oil to further flow into the surrounding rodless cavity 24. As the booster piston rod 2 continues to push forward, the circular hole 23 is completely in contact with the inner wall of the injection valve plate 1, so that the pressure oil is completely enclosed in the rodless cavity 24.

[0033] In the present invention, a rodless cavity 24 is formed on the outer side of the upper rod body 21 , and the rodless cavity 24 is arranged on the outer side of the circular hole 23 .

[0034] Furthermore, during the boosting process, as the boosting piston rod 2 moves, the rodless chamber 24 is separated from the circular hole 23. At this time, the pressure of the pressure oil in the rodless chamber 24 is approximately equal to the system pressure, and as the boosting piston rod 2 continues to move forward, the volume of the pressure oil compressed by the boosting piston rod 2 is only the volume of the pressure oil in the rodless chamber 24. This structural design avoids the problem that during the boosting process of the traditional boosting structure, the volume of the pressure oil compressed by the piston rod is large, resulting in a long pressure building time. Through the design of the rodless chamber 24 and the circular hole 23, the efficiency of pressure oil building is further improved and the problem of the boosting piston rod 2 being offset due to the large volume of pressure oil is prevented.

[0035] In the utility model, a first cavity 221 is opened at the center of the lower rod body 22 , and the input end of the first cavity 221 is connected to the boosting valve plate 5 .

[0036] Furthermore, a booster cylinder sleeve 4 is installed on the outer side of the lower rod body 22, and the booster valve plate 5 is fixedly connected to the injection valve plate 1 by bolts, thereby limiting the position of the booster piston rod 2. At the same time, the booster cylinder sleeve 4 provides a displaceable stroke for the booster piston rod 2 on the one hand, and on the other hand, the gap between the booster valve plate 5 and the booster piston rod 2 is filled by setting the booster cylinder sleeve 4. The booster cylinder sleeve 4 also plays the role of a sealing sleeve, thereby preventing the pressure oil from flowing out when it passes through the connection between the booster piston rod 2 and the booster valve plate 5, thereby preventing the internal and external pressures from failing to meet the standards.

[0037] Embodiment 2:

[0038] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, in the present invention, a booster flange 3 is sleeved on the outer side of the lower rod body 22 , and a booster cylinder sleeve 4 is arranged below the booster flange 3 .

[0039] Furthermore, the boost flange 3 is also sleeved on the outside of the boost piston rod 2 to increase the tightness of the connection between the boost piston rod 2 and the injection valve plate 1. Furthermore, when a processing error occurs inside the boost valve plate 1, it is only necessary to adjust the dimensions of the boost flange 3 and the outside of the boost cylinder sleeve 4 to ensure the tightness of the connection between the boost valve plate 1 and the boost piston rod 2. By simply reworking the boost flange 3 and the boost cylinder sleeve 4, the need to rework the boost piston rod 2 or the boost valve plate 1 is avoided, reducing the cost requirements for manufacturing this structure. The maintenance cost of this boost structure is also reduced through modular design.

[0040] In the present invention, the boost flange 3 is arranged inside the injection valve plate 1 , and the end of the lower rod 22 is provided with a base extending outward, and the base is installed in cooperation with the boost cylinder sleeve 4 .

[0041] Furthermore, the base extending outward from the lower rod body 22 is installed in cooperation with the inner wall of the booster cylinder sleeve 4, and the overall stroke of the booster piston rod 2 can be controlled by controlling the length of the booster cylinder sleeve 4 and the thickness of the base.

[0042] In the present invention, the end of the lower rod 22 is arranged outside the injection valve plate 1 , and the end of the injection valve plate 1 is connected to the boosting valve plate 5 .

[0043] In the present invention, a gap of at most 0.05 mm is provided between the injection valve plate 1 and the upper end of the booster piston rod 2 .

[0044] Furthermore, at the connection between the upper rod body 21 and the inner wall of the injection valve plate 1, an annular groove is opened on the inner wall of the injection valve plate 1, and the depth of the annular groove is at most 0.05 mm. This design can improve the phenomenon of the booster piston rod 2 getting stuck, and avoid the booster piston rod 2 being frequently displaced for a long time, resulting in wall wear and then causing the booster piston rod 2 to deviate.

[0045] Furthermore, as a preferred solution, after the injection is completed, the pressurization stage begins, the pressurization inlet switch valve is opened, the nitrogen in the nitrogen bottle is filled into the rodless chamber of the gas-liquid booster, the piston rod of the gas-liquid booster is pushed downward, and the hydraulic oil flows into the rodless chamber 24 of the injection cylinder through the pressurization inlet switch valve to achieve pressurization. When the pressurization outlet switch valve is opened, the hydraulic oil in the annular chamber of the gas-liquid booster can also flow into the rodless chamber 24 of the injection cylinder through the pressurization outlet switch valve. At this time, the pressure of the hydraulic oil flowing into the rodless chamber 24 of the injection cylinder through the pressurization outlet switch valve can be controlled by the servo valve, and the servo valve itself can control the injection speed of the injection cylinder, thereby realizing that one servo valve can control both the pressure and speed of the injection cylinder, and realize double closed-loop control.

[0046] The booster oil flows into the rodless chamber 24 of the injection cylinder through the booster outlet switch valve and the gap between the booster valve plate 5 and the booster piston rod 2 is filled by setting the booster cylinder sleeve 4. The booster cylinder sleeve 4 also plays the role of a sealing sleeve to prevent the pressure oil from flowing out when it passes through the connection between the booster piston rod 2 and the booster valve plate 5, causing the internal and external pressures to fail to meet the standards.

[0047] The above shows and describes the basic principles and main features of the utility model and the advantages of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic features of the utility model. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is defined by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims. Any figure mark in the claims should not be regarded as limiting the claims involved.

Claims

1. A die casting machine pressurization structure, characterized in that: It comprises a shot valve plate (1), a booster piston rod (2) being arranged in the middle of the shot valve plate (1), the booster piston rod (2) comprising an upper rod body (21) and a lower rod body (22), and a plurality of circular holes (23) being arranged around the upper rod body (21) near the end thereof.

2. A die casting machine pressurization structure according to claim 1, characterized in that: A rodless cavity (24) is provided on the outer side of the upper rod body (21), and the rodless cavity (24) is arranged on the outer side of the circular hole (23).

3. A die casting machine pressurization structure according to claim 1, characterized in that: A first cavity (221) is provided at the centre of the lower rod body (22), and an input end of the first cavity (221) is connected to a pressure-boosting valve plate (5).

4. A die casting machine pressurization structure according to claim 1, characterized in that: A booster flange (3) is sleeved on the outer side of the lower rod body (22), and a booster cylinder sleeve (4) is arranged below the booster flange (3).

5. A die casting machine pressurization structure according to claim 4, characterized in that: The boost flange (3) is arranged inside the injection valve plate (1), and the end of the lower rod body (22) is provided with a base extending outward, and the base is mounted in cooperation with the boost cylinder sleeve (4).

6. A die casting machine pressurization structure according to claim 3, characterized in that: The end of the lower rod body (22) is arranged outside the injection valve plate (1), and the end of the injection valve plate (1) is connected to the boosting valve plate (5).

7. A die casting machine pressurization structure according to claim 1, characterized in that: A gap of at most 0.05 mm is provided between the injection valve plate (1) and the upper end of the booster piston rod (2).

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