A method for increasing the injection force of a high-pressure casting machine

Abstract

This invention relates to the field of die-casting machine technology, specifically disclosing a method for improving the injection force of a high-pressure die-casting machine. A branch oil channel is connected in parallel to the oil inlet pipe connecting the injection cylinder and the accumulator. A supplementary valve is installed on the branch oil channel. The output end of both the branch channel and the output end of the oil inlet pipe are connected to the rodless chamber of the injection cylinder. A main valve is installed on the oil inlet pipe. During die-casting injection, slow filling is used first, followed by fast filling. The injection speed of slow filling is less than that of fast filling. During fast filling, both the main valve and the supplementary valve are opened simultaneously. This solution addresses the problem of low injection force and slow injection speed in existing old die-casting machines.

Description

Technical Field

[0001] This invention relates to the field of die-casting machine technology, and more specifically to a method for increasing the injection force of a high-pressure die-casting machine. Background Technology

[0002] With the development of modern industry, the requirements for product quality and complexity in die casting products have greatly increased. To meet the demands for product performance, higher-performance die casting machines are constantly emerging. However, while die casting machines can have a service life of 8, 10 years or even longer, their purchase cost is high. Therefore, die casting product manufacturers are reluctant to replace their die casting machines while considering costs.

[0003] However, older die-casting machines have lower injection force, resulting in a maximum injection speed of 4-5 m / s. When producing die-cast products with complex structures, the maximum injection speed of 4-5 m / s cannot meet the requirement of completing the injection quickly in a short time, resulting in porosity in the produced products and reducing the yield rate. Summary of the Invention

[0004] The present invention aims to provide a method for improving the injection force of a high-pressure die casting machine, so as to solve the problems of low injection force and slow injection speed in old die casting machines in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for increasing the injection force of a high-pressure die-casting machine involves connecting a branch oil passage in parallel to the oil inlet pipeline connecting the injection cylinder and the accumulator. A supplementary valve is installed on the branch oil passage. The output end of the branch oil passage and the output end of the oil inlet pipeline are both connected to the rodless chamber of the injection cylinder. A main valve is installed on the oil inlet pipeline. During die-casting, slow filling is used first, followed by fast filling. The injection speed of slow filling is less than that of fast filling. During fast filling, the main valve and the supplementary valve are opened simultaneously.

[0007] The principle and advantages of this solution are as follows: By connecting branch oil channels in parallel to the inlet oil line and installing supplementary valves on the branch oil channels, the high-pressure casting machine can be controlled in the same way as before during slow and fast injection, simply by closing the supplementary valves, without increasing the difficulty of control. When a higher injection pressure is required to increase the injection speed, the supplementary valves on the branch oil channels are opened, allowing the branch oil channels and the inlet oil line to be connected to the accumulator simultaneously. This increases the cross-section of the oil channel from the accumulator to the injection cylinder, thus allowing more hydraulic oil to enter the rodless chamber of the injection cylinder per unit time. This enables a significant increase in injection force and injection speed on older die-casting machines, meeting the current production requirements for product quality. In addition, the addition of the oil circuit board to the older die-casting machine increases the maximum injection speed and shortens the product injection time, ensuring both product quality and improving production efficiency.

[0008] Preferably, as an improvement, both the main valve and the supplementary valve are proportional valves with flow regulation function.

[0009] Beneficial effects: The flow regulation function of the proportional valve allows the maximum injection speed to be adjusted to adapt to the injection range of different products being die-cast, thus improving the practicality of the die-casting machine.

[0010] Preferably, as an improvement, the proportional valve includes a valve body, a piston cylinder, and an O-type three-position four-way valve. The valve body is provided with an oil port one and an oil port two. A valve core, a valve rod that drives the valve core to move, and a valve seat fixed to the end of the valve rod are slidable in the valve body. The valve seat can block the oil port two. The three-position four-way valve is connected to an accumulator. The three-position four-way valve is used to control the hydraulic oil to enter the rod chamber or rodless chamber of the piston cylinder. The piston cylinder is used to drive the valve rod to move.

[0011] Preferably, as an improvement, both the supplementary valve and the main valve are connected to a two-position four-way valve. The oil inlet P of the two-position four-way valve is connected to the accumulator, the oil suction port T of the two-position four-way valve is connected to the return oil tank, the working oil port A of the two-position four-way valve can be simultaneously connected to the oil inlet and the rodless chamber of the piston cylinder, and the working oil port B of the two-position four-way valve can be simultaneously connected to the oil suction port T and the rod chamber of the piston cylinder. One of the working positions of the two-position four-way valve is that none of the four oil ports are connected.

[0012] Beneficial effect: When the die casting machine needs to inject, the two-position four-way valve must be controlled to be in a state where all four oil ports are not connected before injection oil can be introduced, so as to avoid the proportional valve from being short-circuited or other factors causing die casting operation during non-die casting time.

[0013] Preferably, as an improvement, the working port A of the two-position four-way valve can be connected to the return port of the three-position four-way valve through the position switching of the three-position four-way valve, and the working port B of the two-position four-way valve can be connected to the inlet port of the three-position four-way valve through the position switching of the three-position four-way valve.

[0014] Beneficial effects: The design of the two-position four-way valve in this solution ensures that, in non-injection mode, the two-position four-way valve remains connected between the inlet port P and the working port A. In this state, it can prevent the proportional valve from opening port two due to misoperation, and it can also allow the hydraulic oil in the rodless chamber of the injection cylinder to enter the return oil tank through the valve body, the three-position four-way valve, and then the two-position four-way valve when the injection cylinder is depressurized. The position of the two-position four-way valve is switched only when injection is required, adjusting the two-position four-way valve to a state where all four ports are disconnected. This ensures safety, does not affect the conventional operation of the die-casting machine in other states, and reduces the difficulty and cost of control.

[0015] Preferably, as an improvement, the system also includes filters installed on the inlet lines of all three-position four-way valves and the inlet lines of the two-position four-way valves, with all inlets connected to the outlet of the filter, so that all inlets can share a single filter, simplifying the hydraulic piping system and reducing costs.

[0016] Preferably, as an improvement, the rodless chamber of the piston cylinder is provided with a spring.

[0017] Beneficial effects: When this solution is adopted, the spring setting ensures that even when the three-position four-way valve is de-energized, the spring still tends to push the piston to move along the rod chamber direction. This, in turn, drives the valve seat closer to port two via the piston rod and valve stem, thereby reducing or blocking the opening of port two and improving safety.

[0018] Preferably, as an improvement, the flow channel diameter of the main valve is larger than that of the supplementary valve. This reduces the difficulty of increasing the branch oil channels and allows for a wider range of injection speed adjustment for the die-casting machine.

[0019] Preferably, as an improvement, when the proportional valve does not need to be opened, the two-position four-way valve keeps the oil inlet connected to the rodless chamber of the piston cylinder, and before the proportional valve is ready to start, the two-position four-way valve is controlled to be in a state where the four oil ports are not connected to each other.

[0020] Beneficial effects: When this solution is adopted, if the proportional valve does not need to be opened and is in a blocked state, the oil inlet P of the two-position four-way valve is connected to the rodless chamber of the piston cylinder through the working oil port A. This allows the hydraulic oil supplied by the accumulator to enter the rodless chamber of the piston cylinder through the two-position four-way valve, even when the high-pressure casting machine is not working and the accumulator has high-pressure energy. The hydraulic oil then enters the rodless chamber of the piston cylinder through the two-position four-way valve, and then presses the valve seat against the oil port two through the piston rod and valve rod two. This ensures that even if the proportional valve is accidentally opened or mis-opened, it will not open, ensuring that the injection cylinder will not work, thereby greatly improving safety performance.

[0021] Preferably, as an improvement, when the high-pressure casting machine opens the mold, it sequentially starts slow opening and fast opening. During slow opening, the main valve is opened and hydraulic oil is supplied through the hydraulic pump. During fast opening, hydraulic oil is supplied simultaneously through the accumulator and the hydraulic pump. During fast opening, the supplementary valve or the main valve is opened. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of the hydraulic circuit board, accumulator, and injection cylinder installed together on the high-pressure casting machine according to an embodiment of the present invention.

[0023] Figure 2 for Figure 1 Right view (with partial section).

[0024] Figure 3 for Figure 2A magnified schematic diagram of a partial section.

[0025] Figure 4 This is a hydraulic schematic diagram showing the connection between the oil circuit structure on the oil circuit board and the accumulator and injection cylinder in an embodiment of the present invention.

[0026] Figure 5 This is a hydraulic diagram illustrating only the relationship between the main valve and the supplementary valve in this embodiment of the invention.

[0027] Figure 6 This is a schematic diagram of the injection cylinder in a slow-speed state during injection, as shown in an embodiment of the present invention.

[0028] Figure 7 This is a schematic diagram of the rapid filling state of the injection cylinder during injection in an embodiment of the present invention.

[0029] Figure 8 This is a schematic diagram of the state of the injection cylinder when it is in the rodless chamber depressurization (injection cylinder reset) in an embodiment of the present invention. Detailed Implementation

[0030] The following detailed description illustrates the specific implementation method:

[0031] The reference numerals in the accompanying drawings include: oil circuit board 10, accumulator 20, injection cylinder 30, oil inlet pipe 301, rodless chamber of injection cylinder 302, main valve 40, main oil passage 101, branch oil passage 102, supplementary valve 50, valve body 1, piston cylinder 2, piston 21, piston rod 22, spring 23, three-position four-way valve 3, oil port one 11, oil port two 12, valve core 13, valve stem 14, valve seat 15, two-position four-way valve 4, and filter 5.

[0032] Example

[0033] Combination Figures 1 to 8 A method for improving the injection force of a high-pressure casting machine requires the addition of an oil circuit board 10 between the accumulator 20 and the injection cylinder 30. The oil circuit board 10 has a main oil passage 101 and a branch oil passage 102. The injection cylinder 30 is provided with an oil inlet pipe 301. The output end of the oil inlet pipe 301 is connected to the rodless chamber 302 of the injection cylinder. A main valve 40 is installed on the oil inlet pipe 301. The main oil passage 101 is connected between the output end of the accumulator 20 and the input end of the oil inlet pipe 301. One end of the branch oil passage 102 is connected to the output end of the accumulator 20, and the other end of the branch oil passage 102 is connected to the rodless chamber 302 of the injection cylinder. A supplementary valve 50 is installed on the branch oil passage 102. That is, through the setting of the oil circuit board 10 with the main oil passage 101 and the branch oil passage 102, the branch passage and the oil inlet pipeline 301 are connected in parallel, that is, there are two oil inlet paths between the accumulator 20 and the injection cylinder 30.

[0034] The flow channel diameter of the main valve 40 is larger than that of the supplementary valve 50.

[0035] Both the main valve 40 and the supplementary valve 50 are proportional valves with flow regulation function.

[0036] The proportional valve includes a valve body 1, a piston cylinder 2, and an O-type three-position four-way valve 3. The valve body 1 is provided with an oil port 11 and an oil port 12. A valve core 13 slides inside the valve body 1, a valve stem 14 that drives the valve core 13 to move, and a valve seat 15 fixed to the end of the valve stem 14. The valve seat 15 can block the oil port 12. After the valve seat 15 moves away from the oil port 12, the oil port 11 and the oil port 12 are connected, realizing the opening of the proportional valve. The three-position four-way valve 3 is connected to the accumulator 20. The three-position four-way valve 3 is used to control the hydraulic oil to enter the rod chamber or the rodless chamber of the piston cylinder 2. The piston cylinder 2 is used to drive the valve stem 14 to move. The rodless chamber of the piston cylinder 2 is provided with a spring 23.

[0037] Specifically, a piston 21 and a piston rod 22 fixed on the piston 21 are slidably connected inside the piston cylinder 2. After the piston rod 22 passes through the piston cylinder 22, it is fixedly connected to the valve rod 14.

[0038] The oil inlet P of the three-position four-way valve 3 is connected to the accumulator 20, the oil suction port T of the three-position four-way valve 3 is connected to the return oil tank, the working port A of the three-position four-way valve 3 is connected to the rodless chamber of the piston cylinder 2, and the working port B of the three-position four-way valve 3 is connected to the rod chamber of the piston cylinder 2.

[0039] Both the supplementary valve 50 and the main valve 40 are connected to a two-position four-way valve 4. The oil inlet P of the two-position four-way valve 4 is connected to the oil outlet of the accumulator 20, and the oil suction port T of the two-position four-way valve 4 is connected to the return oil tank. The working oil port A of the two-position four-way valve 4 can be connected to both the oil inlet P of the two-position four-way valve 4 and the rodless chamber of the piston cylinder 2 at the same time. The working oil port B of the two-position four-way valve 4 can be connected to both the oil suction port T and the rod chamber of the piston cylinder 2 at the same time. One working position of the two-position four-way valve 4 is that none of the four oil ports are connected. The other working position of the two-position four-way valve 4 is that port P is connected to port A and port B is connected to port T.

[0040] The working port A of the two-position four-way valve 4 can be connected to the return port of the three-position four-way valve 3 by switching the position of the three-position four-way valve 3, and the working port B of the two-position four-way valve 4 can be connected to the inlet port of the three-position four-way valve 3 by switching the position of the three-position four-way valve 3.

[0041] It also includes filters 5 installed on the inlet pipes of all three-position four-way valves 3 and the inlet pipes of two-position four-way valves 4. All inlets are connected to the outlet of the filter 5 so that all inlets can share a single filter 5, which simplifies the hydraulic piping system and reduces costs.

[0042] The specific process of this embodiment is as follows:

[0043] A method for increasing the injection force of a high-pressure die casting machine involves first using slow-speed filling during die casting, followed by fast-speed filling. The injection speed of the slow-speed filling is less than that of the fast-speed filling. During fast-speed filling, the main valve 40 and the supplementary valve 50 are opened simultaneously.

[0044] The maximum injection speed is adjusted by the opening of the oil outlet 12 on the supplementary valve 50 or the main valve 40.

[0045] Combination Figure 6 The specific slow packing state is as follows: the two-position four-way valve 4 connected to the supplementary valve 50 is in the state where port P is connected to port A, and port A of the two-position four-way valve 4 is connected to the rodless chamber of the piston cylinder 2. In this state, the supplementary valve 50 is always kept in the state where port 11 and port 212 are not connected due to the influence of the two-position four-way valve 4 connected to the device. The supplementary valve 50 is closed. The main valve 40 is opened, and the two-position four-way valve 4 connected to the main valve 40 is controlled to be in the state where the four ports are not connected to each other. At this time, the opening degree of the proportional valve is only affected by the three-position four-way valve 3 on the main valve 40. In the state where the main valve 40 is open, hydraulic oil is supplied through the accumulator 20.

[0046] Combination Figure 7 The specific rapid filling state is as follows: both two two-position four-way valves 4 are in a state where the four oil ports are not connected to each other. In this state, both the supplementary valve 50 and the main valve 40 are open. The high-pressure hydraulic oil in the accumulator 20 (at this time, the hydraulic oil pressure discharged from the accumulator 20 is much greater than the hydraulic oil pressure discharged from the accumulator 20 at slow speed) is injected into the rodless chamber 302 of the injection cylinder 30 simultaneously from the oil inlet pipe 301 and the branch oil passage 102. This forces the pressure in the rodless chamber 302 of the injection cylinder 30 to increase rapidly, thereby increasing the injection force of the injection cylinder 30 and thus increasing the injection speed. By connecting the branch oil passage 102 with the supplementary valve 50 in parallel on the old die-casting machine, the maximum injection force of the high-pressure die-casting machine is greatly improved. With low-cost modification, the maximum injection speed is increased from 4-5m / s to 7m / s.

[0047] This embodiment improves the insufficient injection force on existing old die-casting machines by adding an oil circuit board 10 with a supplementary valve 50. It achieves a low-cost upgrade, and after the upgrade, the die-casting machine not only improves the injection force and injection speed, but is also safer than before. In addition, by setting supplementary valves 50 and main valves 40 with different diameters, the range of injection speed adjustment is expanded, which can meet the molding needs of more die-casting products and improve the practicality of the die-casting machine.

[0048] Example 2

[0049] Example 2 discloses a method for smooth mold opening using the oil inlet pipe 301 and branch oil channel 102 of Example 1, based on Example 1. Specifically, when the high-pressure casting machine opens the mold, it sequentially starts slow opening and fast opening. During slow opening, the main valve 40 is opened and hydraulic oil is supplied through the hydraulic pump of the accumulator 20. During fast opening, hydraulic oil is supplied simultaneously through the nitrogen booster and hydraulic pump of the accumulator 20. During fast opening, the supplementary valve 50 or the main valve 40 is opened.

[0050] For situations where the mold opening speed requirement is low, the mold can be opened simply by opening the supplementary valve 50. For situations where the mold opening speed does not affect product performance but can be increased, the mold can be opened simply by opening the main valve 40.

[0051] Because the flow channel diameter of the supplementary valve 50 is smaller than that of the main valve 40, the opening adjustment range of the supplementary valve 50 and the main valve 40 is different, thereby increasing the range of adjustable quick-opening speeds and improving practicality.

[0052] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for increasing the injection force of a high-pressure casting machine, characterized in that: A hydraulic manifold needs to be added between the accumulator and the injection cylinder. The manifold includes a main hydraulic passage and branch hydraulic passages. An inlet pipe is installed on the injection cylinder, with its output end connected to the rodless chamber of the injection cylinder. A main valve is installed on the inlet pipe. The main hydraulic passage connects the output end of the accumulator and the input end of the inlet pipe. One end of the branch hydraulic passage connects to the output end of the accumulator, and the other end connects to the rodless chamber of the injection cylinder. A supplementary valve is installed on the branch hydraulic passage, allowing it to connect in parallel with the inlet pipe. Both the main valve and the supplementary valve are proportional valves with flow regulation functions, and both are connected to a two-position four-way valve. The oil inlet P of the two-position four-way valve is connected to the accumulator, the oil suction port T of the two-position four-way valve is connected to the return oil tank, the working oil port A of the two-position four-way valve can be connected to the oil inlet and the rodless chamber of the piston cylinder at the same time, and the working oil port B of the two-position four-way valve can be connected to the oil suction port T and the rod chamber of the piston cylinder at the same time. One of the working positions of the two-position four-way valve is that none of the four oil ports are connected. It also includes filters installed before the oil inlet of all three-position four-way valves and the oil inlet of two-position four-way valves, with all oil inlets connected to the oil outlet of the filter. When the die-casting machine opens the mold, it starts the slow opening and fast opening in sequence. During slow opening, the main valve is opened and hydraulic oil is supplied through the hydraulic pump. During fast opening, hydraulic oil is supplied simultaneously through the nitrogen booster of the accumulator and the hydraulic pump. During fast opening, the supplementary valve or the main valve is opened. During die casting, slow filling is used first, followed by fast filling. The injection speed of slow filling is less than that of fast filling. During fast filling, the main valve and the supplementary valve are opened simultaneously. Before the proportional valve is ready to start, the two-position four-way valve is controlled to be in a state where the four oil ports are not connected to each other.

2. The method for increasing the injection force of a high-pressure casting machine according to claim 1, characterized in that: The proportional valve includes a valve body, a piston cylinder, and an O-type three-position four-way valve. The valve body has an oil port one and an oil port two. The valve body contains a valve core, a valve rod that moves the valve core, and a valve seat fixed to the end of the valve rod. The valve seat can block the oil port two. The three-position four-way valve is connected to an accumulator. The three-position four-way valve is used to control the hydraulic oil to enter the rod chamber or rodless chamber of the piston cylinder. The piston cylinder is used to drive the valve rod to move.

3. The method for increasing the injection force of a high-pressure casting machine according to claim 1, characterized in that: The working port A of the two-position four-way valve can be connected to the return port of the three-position four-way valve by switching the position of the three-position four-way valve, and the working port B of the two-position four-way valve can be connected to the inlet port of the three-position four-way valve by switching the position of the three-position four-way valve.

4. The method for increasing the injection force of a high-pressure casting machine according to claim 2, characterized in that: The rodless chamber of the piston cylinder is equipped with a spring.

5. The method for increasing the injection force of a high-pressure casting machine according to claim 2, characterized in that: The flow channel diameter of the main valve is larger than that of the supplementary valve.

6. A method for increasing the injection force of a high-pressure casting machine according to any one of claims 1-5, characterized in that: When the proportional valve does not need to be opened, the two-position four-way valve keeps the oil inlet connected to the rodless chamber of the piston cylinder.

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