Pressure relief protection servo hydraulic system of cap making machine

Abstract

The utility model provides a kind of pressure relief protection servo hydraulic system of cap making machine, including forming device, high-pressure oil supply device, medium-pressure oil supply device, low-pressure oil supply device, oil return path and oil tank, the forming device is equipped with hydraulic cylinder and three-position four-way reversing valve, the load port is communicated with first oil chamber, the both ends of the oil return path are respectively communicated with oil return T port and oil tank;The oil outlet of high-pressure oil supply device and the oil outlet of medium-pressure oil supply device are respectively communicated with first oil chamber by the high-pressure PHI port and the medium-pressure PLO port of three-position four-way reversing valve, the oil outlet of low-pressure oil supply device is communicated with second oil chamber;High-pressure relief control assembly is equipped on the high-pressure oil supply path, medium-pressure relief control assembly is equipped on the medium-pressure oil supply path, low-pressure relief control assembly is equipped on the low-pressure oil supply path.The utility model can effectively relieve pressure to corresponding oil supply pipeline when needing maintenance or equipment abnormity leads to sudden stop, so that the safety of hydraulic system is improved.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic systems for cap-making machines, and specifically to a pressure relief protection servo hydraulic system for cap-making machines. Background Technology

[0002] As a key piece of equipment for producing various bottle caps, cap-making machines are widely used in many industries such as food, beverage, and pharmaceuticals. During the operation of a cap-making machine, the hydraulic system plays a crucial role in providing power for the cap-making action, and its performance directly affects the machine's working efficiency and product quality.

[0003] Currently, the hydraulic system used in cap-making machines ensures the normal operation of the equipment to a certain extent. This system generally consists of a motor, hydraulic pump, control valve group, and oil supply pipes. The motor drives the hydraulic pump, converting mechanical energy into hydraulic energy, which is then delivered to various actuators through the oil supply pipes to realize the cap-making machine's actions such as mold opening and closing, and stamping. However, cap-making machines face complex and variable working conditions, making the hydraulic system prone to abnormalities. For example, during high-speed cap making, due to equipment malfunction or sudden shutdown, the hydraulic pump may experience momentary instability in output flow, causing the pressure in the oil supply pipe to rise rapidly in a short period. In the face of these abnormal conditions, existing cap-making machine hydraulic systems cannot effectively relieve pressure, making the various components of the hydraulic system susceptible to significant damage and affecting the equipment's lifespan. Moreover, abnormal pressure can directly affect the working accuracy of the cap-making machine, leading to quality problems such as dimensional deviations and surface defects in the produced caps.

[0004] For example, patent publication number CN209129948U discloses a hydraulic system for a cap-making machine. The high-pressure, medium-pressure, and low-pressure oil circuits of this patent have insufficient pressure relief capabilities, which can easily lead to equipment damage and a short service life. In particular, in the medium-pressure oil source circuit, following the normal oil supply direction, the one-way valve 404 is located after the safety relief valve 409. When the equipment encounters a sudden power failure, due to the non-reverse flow characteristic of the one-way valve itself, the pressure oil in the PN oil chamber of the distributor cannot be depressurized and returns to the oil tank, and thus remains trapped in the pipeline. Moreover, the medium-pressure oil source circuit is equipped with a conventional pressure reducing valve. When the equipment encounters a sudden power failure, the pressure reducing valve cannot achieve reverse flow, causing the pressure oil in the PL oil chamber of the distributor to remain trapped in the pipeline because it cannot be depressurized and returns to the oil tank.

[0005] Therefore, the existing hydraulic system of cap-making machine has insufficient pressure relief capacity in response to abnormal situations, which has become a key issue restricting the stable operation of cap-making machine and the improvement of product quality. At the same time, there are also significant safety hazards in the equipment. Utility Model Content

[0006] To address the shortcomings of existing technologies, this utility model proposes a pressure relief protection servo hydraulic system for a cap-making machine.

[0007] The technical solution of this utility model is implemented as follows: This utility model discloses a pressure relief protection servo hydraulic system for a cap-making machine, including a forming device, a high-pressure oil supply device, a medium-pressure oil supply device, a low-pressure oil supply device, a return oil circuit, and an oil tank. The forming device is equipped with a hydraulic cylinder and a three-position four-way directional valve. The hydraulic cylinder is equipped with a first oil pressure chamber and a second oil pressure chamber. The three-position four-way directional valve is equipped with a load port, a high-pressure PHI port, a medium-pressure PLO port, and a return oil T port. The load port is connected to the first oil pressure chamber. The two ends of the return oil circuit are respectively connected to the return oil T port and the oil tank.

[0008] The high-pressure oil supply device includes a high-pressure pump set and a high-pressure oil supply line. The oil inlet of the high-pressure oil supply line is connected to the high-pressure pump set. The high-pressure pump set can lead the oil in the oil tank to the high-pressure oil supply line. The oil outlet of the high-pressure oil supply line is connected to the first oil pressure chamber through the high-pressure PHI port.

[0009] The medium-pressure oil supply device includes a medium-pressure pump set and a medium-pressure oil supply line. The oil inlet of the medium-pressure oil supply line is connected to the medium-pressure pump set. The medium-pressure pump set can lead the oil in the oil tank to the medium-pressure oil supply line. The oil outlet of the medium-pressure oil supply line is connected to the first oil pressure chamber through the medium-pressure PLO port.

[0010] The low-pressure oil supply device includes the low-pressure pump set and the low-pressure oil supply line. The oil inlet of the low-pressure oil supply line is connected to the low-pressure pump set. The low-pressure pump set can lead the oil in the oil tank to the low-pressure oil supply line. The oil outlet of the low-pressure oil supply line is connected to the second oil pressure chamber.

[0011] A high-pressure relief control component is provided on the high-pressure oil supply line, a medium-pressure relief control component is provided on the medium-pressure oil supply line, and a low-pressure relief control component is provided on the low-pressure oil supply line.

[0012] Preferably, the high-pressure relief control component includes a first directional valve and a first safety relief valve designed in parallel. The oil inlets of the first directional valve and the first safety relief valve are connected to the high-pressure oil supply circuit, and the oil outlets of the first directional valve and the first safety relief valve are connected to the oil tank. A first accumulator is also connected to the inlet of the first directional valve.

[0013] Preferably, a one-way valve is provided on the high-pressure oil supply line between the high-pressure relief control component and the high-pressure pump group.

[0014] Preferably, a throttling device is connected to the outlet of the first directional valve, and an accumulator is connected to the inlet of the first directional valve.

[0015] Preferably, the medium-pressure relief control component includes a second directional valve and a second safety relief valve designed in parallel. The oil inlets of the second directional valve and the second safety relief valve are respectively connected to the medium-pressure oil supply circuit, and the oil outlets of the second directional valve and the second safety relief valve are connected to the oil tank. A second accumulator is also connected to the inlet of the second directional valve.

[0016] Preferably, a one-way valve is also provided on the low-pressure oil supply line between the medium-pressure pressure relief control component and the medium-pressure pump group.

[0017] Preferably, a two-way directional valve assembly is provided between the medium-pressure pressure relief control component and the oil outlet of the medium-pressure oil supply circuit.

[0018] Preferably, the low-pressure relief control component includes a second directional valve and a second safety relief valve designed in parallel. The oil inlets of the second directional valve and the second safety relief valve are respectively connected to the low-pressure oil supply circuit, and the oil outlets of the second directional valve and the second safety relief valve are connected to the oil tank. A second accumulator is also connected to the inlet of the second directional valve.

[0019] Preferably, a one-way valve and a pressure reducing valve are connected in parallel between the low-pressure relief control component and the oil outlet of the low-pressure oil supply circuit.

[0020] Preferably, a throttle element is connected to the outlet of the second directional valve, and an accumulator is connected to the inlet of the second directional valve.

[0021] Compared with the prior art, this utility model has the following advantages: The pressure relief protection servo hydraulic system of the capping machine of this utility model adopts a combination design of high-pressure oil supply device, medium-pressure oil supply device, and low-pressure oil supply device. The medium-pressure oil supply device and the low-pressure oil supply device realize the mold closing action of the forming device, the high-pressure oil supply device and the low-pressure oil supply device realize the mold forming action of the forming device, and the low-pressure oil supply device and the return oil circuit realize the demolding action of the forming device. Each device can be controlled independently, which has the advantages of fast operation speed, high reliability and stability, and improved production efficiency of bottle capping machine. In addition, high-pressure pressure relief control components, medium-pressure pressure relief control components, and low-pressure pressure relief control components are respectively set on the high-pressure oil supply device, medium-pressure oil supply device, and low-pressure oil supply device, so as to effectively relieve pressure on the corresponding oil supply pipeline when maintenance is required or the equipment malfunctions and causes a sudden shutdown, thereby improving safety. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the pressure relief protection servo hydraulic system of the cap-making machine of this utility model;

[0024] Figure 2 This is a schematic diagram of the molding device.

[0025] Figure 3 This is a diagram showing the flow direction of oil in the low-pressure oil supply circuit when the low-pressure oil supply device is supplying oil normally.

[0026] Figure 4 Diagram showing the flow direction of oil in the low-pressure oil supply circuit when the low-pressure oil supply device is depressurized;

[0027] Figure 5 This is a structural diagram of a two-way directional valve assembly.

[0028] Figure labels: 1. Molding device; 101. Hydraulic cylinder; 1011. First hydraulic chamber; 1012. Second hydraulic chamber; 102. Three-position four-way directional valve; 1021. Load port; 1022. High-pressure PHI port; 1023. Medium-pressure PLO port; 1024. Return oil T port; 2. High-pressure oil supply device; 201. High-pressure pump set; 202. High-pressure oil supply circuit; 203. High-pressure pressure relief control component; 2031. First directional valve; 2032. First safety relief valve; 2033. First accumulator; 2034. First throttle; 204. First check valve; 205. First pressure sensor; 206. First pressure gauge; 3. Medium-pressure oil supply device; 301. Medium-pressure pump set; 302. Medium-pressure oil supply circuit; 303. Medium-pressure relief... 4. Pressure control assembly; 3031, second directional valve; 3032, second safety relief valve; 3033, second accumulator; 3034, second throttle; 304, second check valve; 305, second pressure sensor; 306, second pressure gauge; 307, two-way directional valve assembly; 308, proportional flow valve; 4. Low-pressure oil supply device; 401, low-pressure oil supply line; 4011, third check valve; 4012, pressure reducing valve; 402, third pressure sensor; 5. Return oil line; 501, relief valve; 502, buffer; 504, third throttle; 505, fourth check valve; 6. Cooling circulation filtration device; 601, cooling filter pump assembly; 602, water cooler; 603, filter; 604, oil quantity indicator; 7. Oil tank. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," "third," and "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] See Figure 1 and Figure 2 This utility model discloses a pressure relief protection servo hydraulic system for a cap-making machine, including a forming device 1, a high-pressure oil supply device 2, a medium-pressure oil supply device 3, a low-pressure oil supply device 4, a return oil circuit 5, and an oil tank 7. The forming device 1 is equipped with a hydraulic cylinder 101 and a three-position four-way directional valve 102. The hydraulic cylinder 101 is equipped with a first oil pressure chamber 1011 and a second oil pressure chamber 1012. The three-position four-way directional valve 102 is equipped with a load port 1021, a high-pressure PHI port 1022, a medium-pressure PLO port 1023, and a return oil T port 1024. The load port 1021 is connected to the first oil pressure chamber 1011. The two ends of the return oil circuit 5 are respectively connected to the return oil T port 1024 and the oil tank 7.

[0033] The high-pressure oil supply device 2 includes a high-pressure pump set 201 and a high-pressure oil supply line 202. The oil inlet of the high-pressure oil supply line 202 is connected to the high-pressure pump set 201. The high-pressure pump set 201 can lead the oil in the oil tank 7 to the high-pressure oil supply line 202. The oil outlet of the high-pressure oil supply line 202 is connected to the first oil pressure chamber 1011 through the high-pressure PHI port 1022.

[0034] The medium-pressure oil supply device 3 includes a medium-pressure pump group 301 and a medium-pressure oil supply line 302. The oil inlet of the medium-pressure oil supply line 302 is connected to the medium-pressure pump group 301. The medium-pressure pump group 301 can lead the oil in the oil tank 7 to the medium-pressure oil supply line 302. The oil outlet of the medium-pressure oil supply line 302 is connected to the first oil pressure chamber 1011 through the medium-pressure PLO port 1023.

[0035] The low-pressure oil supply device 4 includes the low-pressure pump group 301 and the low-pressure oil supply line 401. The oil inlet of the low-pressure oil supply line 401 is connected to the low-pressure pump group 301. The low-pressure pump group 301 can lead the oil in the oil tank 7 to the low-pressure oil supply line 401. The oil outlet of the low-pressure oil supply line 401 is connected to the second oil pressure chamber 1012.

[0036] The high-pressure oil supply line 202 is equipped with a high-pressure pressure relief control component 203, the medium-pressure oil supply line is equipped with a medium-pressure pressure relief control component 303, and the low-pressure oil supply line is equipped with a low-pressure pressure relief control component.

[0037] In this embodiment, the present invention utilizes a combination design of a high-pressure oil supply device 2, a medium-pressure oil supply device 3, and a low-pressure oil supply device 4. The medium-pressure oil supply device 3 and the low-pressure oil supply device 4 are used to realize the mold closing action of the molding device 1, the high-pressure oil supply device 2 and the low-pressure oil supply device 4 are used to realize the molding action of the molding device 1, and the low-pressure oil supply device 4 and the return oil circuit 5 are used to realize the demolding action of the molding device 1. Each device can be controlled independently, which has the advantages of fast operation speed, high reliability and stability, and improved production efficiency of bottle cap machine. In addition, a high-pressure pressure relief control component 203, a medium-pressure pressure relief control component 303, and a low-pressure pressure relief control component are respectively set on the high-pressure oil supply device 2, the medium-pressure oil supply device 3, and the low-pressure oil supply device 4, so as to effectively relieve pressure on the corresponding oil supply lines when maintenance is required or when equipment malfunctions and causes a sudden shutdown, thereby improving safety.

[0038] In this embodiment, as Figure 1 As shown, both the high-pressure pump group 201 and the medium-pressure pump group 301 can adopt a combination of servo motor and fixed displacement pump to further reduce system energy consumption; moreover, by using servo motor for control, the pressure and flow of the hydraulic system can be dually regulated.

[0039] Specifically, the high-pressure relief control component 203 includes a first directional valve 2031 and a first safety relief valve 2032 designed in parallel. The oil inlets of the first directional valve 2031 and the first safety relief valve 2032 are connected to the high-pressure oil supply circuit 202, and the oil outlets of the first directional valve 2031 and the first safety relief valve 2032 are connected to the oil tank 7. The inlet of the first directional valve 2031 is also connected to a first accumulator 2033. In this embodiment, before the equipment is shut down normally, such as when it is necessary to repair or replace parts on the high-pressure oil supply device 2, the first directional valve 2031 is opened first to release the pressure oil stored in the first accumulator 2033 at a small flow rate. This prevents the equipment from making abnormal noises due to the instantaneous pressure impact caused by the large flow of oil directly discharged from the high-pressure oil supply line 202 and the first accumulator 2033 when the first directional valve 2031 and the first safety relief valve 2032 are opened at the same time. When the equipment suddenly stops due to an abnormality, the first directional valve 2031 and the first safety relief valve 2032 will open at the same time to quickly return the oil on the high-pressure oil supply line 202 to the oil tank 7, so as to quickly depressurize the high-pressure oil supply line 202, thereby improving the safety of the equipment when an abnormality occurs.

[0040] The high-pressure oil supply circuit 202 is equipped with a first pressure sensor 205 and a first pressure gauge 206. The first pressure sensor 205, first pressure gauge 206, first directional valve 2031, and first safety relief valve 2032 are connected to the electrical control system of the pressure relief protection servo hydraulic system. The electrical control system can be connected to a control terminal via a wireless network or a wired network. The first pressure sensor 205 detects the oil pressure in the high-pressure oil supply circuit 202 and converts it into an electrical signal, which is then sent to the electrical control system. This allows the electrical control system to control the operation of the first directional valve 2031 and the first safety relief valve 2032 based on the signal from the first pressure sensor 205. The first pressure gauge 206 measures and displays the oil pressure value in the high-pressure oil supply circuit 202.

[0041] The high-pressure oil supply circuit 202 between the high-pressure pressure relief control component 203 and the high-pressure pump group 201 is equipped with a first one-way valve 204. Specifically, in this embodiment, the first one-way valve 204 is positioned before the first safety relief valve 2032 in the normal oil supply direction. This ensures that in the event of a power outage or other emergency, the pressurized oil in the oil chamber of the equipment distributor can flow back to the oil tank 7 through the first safety relief valve 2032, avoiding pressure buildup inside the equipment and pipelines, which could cause safety hazards. At the same time, the first one-way valve 204 can also prevent the backflowing pressurized oil from rushing towards the high-pressure pump group 201 and causing the high-pressure pump group 201 to reverse.

[0042] Furthermore, the outlet of the first directional valve 2031 is also connected to a first throttling element 2034 to further reduce the flow rate and thus avoid abnormal noise from the equipment.

[0043] Specifically, the medium-pressure relief control component 303 includes a second directional valve 3031 and a second safety relief valve 3032 designed in parallel. The oil inlets of the second directional valve 3031 and the second safety relief valve 3032 are respectively connected to the medium-pressure oil supply circuit 302, and the oil outlets of the second directional valve 3031 and the second safety relief valve 3032 are connected to the oil tank 7. A second accumulator 3033 is also connected to the inlet of the second directional valve 3031. In this embodiment, similarly, before the equipment is shut down normally, such as when it is necessary to repair or replace parts on the medium-pressure oil supply device 3, the second directional valve 3031 is opened first to release the pressure oil stored in the second accumulator 3033 at a small flow rate. This prevents the large flow rate of the medium-pressure oil supply circuit 302 and the second accumulator 3033 from being directly discharged due to instantaneous pressure shock when the second directional valve 3031 and the second safety relief valve 3032 are opened at the same time, which could cause abnormal noise in the equipment. When the equipment suddenly shuts down due to an abnormality, the second directional valve 3031 and the second safety relief valve 3032 will be opened at the same time to quickly return the oil on the medium-pressure oil supply circuit 302 to the oil tank 7, thereby quickly depressurizing the medium-pressure oil supply circuit 302 and improving the safety of the equipment when an abnormality occurs.

[0044] In addition, the low-pressure relief control component includes a second directional valve 3031 and a second safety relief valve 3032 designed in parallel. The oil inlets of the second directional valve 3031 and the second safety relief valve 3032 are respectively connected to the low-pressure oil supply circuit 401, and the oil outlets of the second directional valve 3031 and the second safety relief valve 3032 are connected to the oil tank 7. The inlet of the second directional valve 3031 is also connected to a second accumulator 3033. In this embodiment, the medium-pressure oil supply device 3 and the low-pressure oil supply device 4 can share the same pressure relief control component and the medium-pressure pump group 301, that is, the medium-pressure oil supply circuit 302 and the low-pressure oil supply circuit 401 have a common oil circuit section. Before the equipment is shut down normally, such as when it is necessary to repair or replace the parts on the medium-pressure oil supply device 3 or the low-pressure oil supply device 4, the electrical control system controls the second directional valve 3031 to open first to release the pressure oil stored in the second accumulator 3033 at a small flow rate, so as to avoid the second directional valve 3031 from opening first. When the second safety relief valve 3032 is opened simultaneously, the large flow of direct discharge in the medium-pressure oil supply circuit 302 and the second accumulator 3033 causes abnormal noise in the equipment due to instantaneous pressure impact. When the equipment suddenly stops due to abnormality, the electrical control system controls the second directional valve 3031 and the second safety relief valve 3032 to open simultaneously so as to quickly return the oil on the medium-pressure oil supply circuit 302 to the oil tank 7, so as to quickly depressurize the low-pressure oil supply circuit 401, thereby improving the safety of the equipment when abnormality occurs.

[0045] The medium-pressure oil supply circuit 302 is equipped with a second pressure sensor 305, while the low-pressure oil supply circuit 401 is equipped with a third pressure sensor 402. The second pressure sensor 305, the third pressure sensor 402, the second pressure gauge 306, the second directional valve 3031, and the second safety relief valve 3032 are connected to the electrical control system of the pressure relief protection servo hydraulic system. The electrical control system can be connected to the control terminal via a wireless network or a wired network. The second pressure sensor 305 can detect the oil pressure in the medium-pressure oil supply circuit 302, and the third pressure sensor 402 can detect the oil pressure in the low-pressure oil supply circuit 401, and convert them into electrical signals and send them to the electrical control system. This allows the electrical control system to control the operation of the second directional valve 3031 and the second safety relief valve 3032 based on the signals sent by the second pressure sensor 305 and the third pressure sensor 402. A second pressure gauge 306 is installed at the outlet of the second safety relief valve 3032 to measure and display the oil pressure value of this circuit.

[0046] In this embodiment, the medium-pressure oil supply device 3 and the low-pressure oil supply device 4 share the second pressure gauge 306, the second directional valve 3031, and the second safety relief valve 3032, which can save system manufacturing costs.

[0047] In addition, a second check valve 304 is provided on the low-pressure oil supply line 401 between the medium-pressure pressure relief control component 303 and the medium-pressure pump group 301. Specifically, in this embodiment, the second check valve 304 is positioned before the second safety relief valve 3032 in the direction of normal oil supply. This ensures that in the event of a power outage or other emergency, the pressurized oil in the PLO and / or PRE oil chambers of the equipment distributor can flow back to the oil tank 7 normally through the second safety relief valve 3032, avoiding pressure buildup inside the equipment and pipelines, which could cause safety hazards. At the same time, the second check valve 304 can also prevent the backflowing pressurized oil from rushing towards the medium-pressure pump group 301 and causing the medium-pressure pump group 301 to reverse, thereby improving equipment safety.

[0048] A third check valve 4011 and a pressure reducing valve 4012 are connected in parallel between the low-pressure relief control component and the oil outlet of the low-pressure oil supply circuit 401. When the low-pressure oil supply device 4 is supplying oil normally, as shown in section 2 and... Figure 3 As shown, the oil flows from the pressure reducing valve 4012 to the low-pressure PRE port. Because the pressures at the inlet and outlet of the check valve 4011 are equal, the check valve cannot open, and the flow will not flow to the branch. However, when the low-pressure oil supply line 401 needs to release pressure and return oil, such as... Figure 2 and Figure 4 As shown, due to the irreversible nature of the pressure reducing valve 4012 in a short period of time, the oil in the low-pressure PRE port cannot flow back to the low-pressure oil supply device 4 through the pressure reducing valve. At this time, the pressure at the inlet of the check valve 4011 is greater than the pressure at the outlet, which allows the oil in the low-pressure PRE port to flow back to the low-pressure oil supply device 4 through the check valve 4011 and then back to the oil tank 7.

[0049] In this embodiment, while the pressure reducing valve 4012 is equipped to meet the working conditions, a second check valve 304 is added in parallel. When the equipment encounters a sudden power outage or the equipment needs maintenance, the pressure oil in the PRE oil chamber of the oil distributor flows back through the second check valve 304 to the medium-pressure oil source main oil circuit, and then flows back to the oil tank 7 through the second safety relief valve 3032.

[0050] Similarly, the outlet of the second directional valve 3031 is also connected to a second throttle 3034. The second directional valve 3031 can be a small-diameter valve, and the throttle can further reduce the flow rate to avoid abnormal noise from the equipment. In this embodiment, before normal shutdown, it is necessary to release the energy stored in the accumulator, that is, to first start the second directional valve 3031. The pressurized oil in the second accumulator 3033 flows back to the oil tank 7 through the second directional valve 3031 and then through the throttle. Through the double-layer throttling design of this embodiment, the instantaneous pressure shock in the pipeline when the second accumulator 3033 is depressurized can be reduced.

[0051] Furthermore, a two-way directional valve assembly 307 is provided on the oil supply line between the medium-pressure pressure relief control assembly 303 and the oil outlet of the medium-pressure oil supply line 302. For example, Figure 5 As shown, the two-way directional valve assembly 307 consists of a two-way logic valve and a directional valve. During normal operation, the solenoid of the directional valve remains in its normal position, preventing control oil X from entering the upper spring chamber of the two-way logic valve via the directional valve. At this time, the pressure at port A of the two-way logic valve is greater than its spring force, keeping the two-way logic valve open. In this embodiment, this function is designed to ensure that, regardless of whether the equipment is in normal operation or encounters an emergency, the oil at the medium-pressure PLO port can flow freely between ports A and B of the two-way logic valve, thereby enabling communication with the medium-pressure oil supply device 3.

[0052] Among them, a proportional flow valve 308 is connected in series on the medium-pressure oil supply line 302 at the outlet of the two-way directional valve group 307, which can adjust the oil flow rate of the medium-pressure PLO port in real time to ensure the stability of product quality.

[0053] In this embodiment, a bypass branch is provided on the return oil line 5, and an overflow valve 501 is connected in series on the bypass branch to maintain the pressure stability of the low-pressure PRE port and keep it within the range required by the equipment; if an overpressure occurs, the overflow valve 501 will open to protect the safety of the low-pressure oil supply line 401.

[0054] In addition, a buffer 502 is provided on the return oil circuit 5 to absorb the instantaneous pressure shock generated when the oil cylinder returns oil, so as to alleviate the mechanical collision of the oil cylinder; in addition, a third throttle 504 and a fourth check valve 505 are also provided on the return oil circuit 5 in parallel to generate a stable return oil back pressure, so that the equipment can ensure stable operation when the main valve of the equipment is reset.

[0055] It is understood that the fuel tank 7 is equipped with a temperature sensor, a liquid level sensor, an air filter, and a liquid level gauge. The temperature sensor and the liquid level sensor are respectively connected to the electrical control system, which is connected to the control terminal via a wireless network. Thus, the temperature sensor can detect the temperature of the fuel in the fuel tank 7 and convert it into an electrical signal, which is then sent to the electrical control system. The electrical control system can control the heating or cooling device based on the signal from the temperature sensor, thereby monitoring the temperature of the fuel in the fuel tank 7. The liquid level sensor can detect the liquid level and convert it into an electrical signal, which is then sent to the electrical control system. The electrical control system can send an alarm to the control terminal indicating a low fuel level in the fuel tank 7 based on the signal from the liquid level sensor. The air filter is used to remove particulate impurities from the air inside the fuel tank 7. The liquid level gauge is used to measure and display the liquid level.

[0056] In addition, the hydraulic system of the cap-making machine of this utility model also includes a cooling circulation filter device 6. The cooling circulation filter device 6 is installed on the oil tank 7. The cooling circulation filter device 6 is provided with a cooling filter circuit. The oil inlet and oil outlet of the cooling filter circuit are both connected to the oil tank 7. The cooling filter circuit is provided with a cooling filter pump group 601, a water cooler 602, a filter 603 and an oil level indicator 604 in sequence according to the oil flow direction. The cooling circulation filter device 6 of this utility model can effectively ensure the cleanliness of the oil through the cooling filter pump group 601, the water cooler 602 and the filter 603. At the same time, the design of the cooling circulation filter device 6 effectively reduces the temperature of the hydraulic oil, ensures that the viscosity of the hydraulic oil meets the usage requirements, realizes the recycling of hydraulic oil, saves costs and improves the effective utilization rate of resources.

[0057] In the design of the hydraulic system of this utility model, in all oil source circuits (including high pressure, medium pressure, low pressure, and circulating cooling), the one-way valves in each oil circuit are positioned before the safety relief valve, following the normal oil supply direction. This ensures that in the event of a power outage or other emergency, the pressurized oil in the distributor chamber can flow back to the oil tank 7 normally through the safety relief valve, preventing pressure buildup inside the equipment and pipelines, which could cause safety hazards. In addition, in the design of the hydraulic system, all accumulators are equipped with drain valves. Before the equipment is shut down normally (such as for maintenance), the pressurized oil stored in the accumulators can be drained at a low flow rate through the pressure relief valve, avoiding abnormal noise caused by instantaneous pressure shocks due to large-flow direct discharge.

[0058] In summary, through the combined design of the high-pressure oil supply device 2, the medium-pressure oil supply device 3, and the low-pressure oil supply device 4, the present utility model utilizes the medium-pressure oil supply device 3 and the low-pressure oil supply device 4 to achieve the mold closing action of the molding device 1, utilizes the high-pressure oil supply device 2 and the low-pressure oil supply device 4 to achieve the mold pressing and forming action of the molding device 1, and utilizes the low-pressure oil supply device 4 and the oil return circuit 5 to achieve the demolding action of the molding device 1. Each device part can be independently controlled. Additionally, high-pressure pressure relief control components 203, medium-pressure pressure relief control components 303, and low-pressure pressure relief control components are respectively provided on the high-pressure oil supply device 2, the medium-pressure oil supply device 3, and the low-pressure oil supply device 4. Among them, by respectively providing pressure sensors on the high-pressure oil supply device 2, the medium-pressure oil supply device 3, and the low-pressure oil supply device 4, etc., it is convenient to automatically monitor the pressure of each branch. In addition, through the control terminal (i.e., the central control room or the mobile communication device), local or remote linkage control can be performed. It has a strong fault self-diagnosis function. Once abnormalities such as pressure occur in the hydraulic equipment, the hydraulic control system will automatically prompt and alarm relevant system operators and equipment manufacturers through the mobile communication device (i.e., the SMS method or the APP client of the mobile communication device), which is convenient for the hydraulic equipment manufacturer to detect and monitor the operating conditions of the hydraulic equipment and collect the causes of system failures. When maintenance is required or the equipment suddenly stops due to abnormalities, the present utility model can effectively relieve the pressure of the corresponding oil supply pipeline, thereby improving the safety of the equipment. At the same time, the main power configuration of the entire hydraulic system uses servo motors, which are controlled through communication between the servo driver and the control terminal. The servo motor can transiently adjust the pressure and flow rate of the hydraulic system according to the real-time requirements of the equipment, further reducing the energy consumption of the system and making the equipment more energy-saving and environmentally friendly.

[0059] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A pressure relief protection servo hydraulic system for a cap-making machine, characterized in that, It includes a molding device, a high-pressure oil supply device, a medium-pressure oil supply device, a low-pressure oil supply device, a return oil circuit, and an oil tank. The molding device is equipped with a hydraulic cylinder and a three-position four-way directional valve. The hydraulic cylinder is equipped with a first oil pressure chamber and a second oil pressure chamber. The three-position four-way directional valve is equipped with a load port, a high-pressure PHI port, a medium-pressure PLO port, and a return oil T port. The load port is connected to the first oil pressure chamber. The two ends of the return oil circuit are connected to the return oil T port and the oil tank, respectively. The high-pressure oil supply device includes a high-pressure pump set and a high-pressure oil supply line. The oil inlet of the high-pressure oil supply line is connected to the high-pressure pump set. The high-pressure pump set can lead the oil in the oil tank to the high-pressure oil supply line. The oil outlet of the high-pressure oil supply line is connected to the first oil pressure chamber through the high-pressure PHI port. The medium-pressure oil supply device includes a medium-pressure pump set and a medium-pressure oil supply line. The oil inlet of the medium-pressure oil supply line is connected to the medium-pressure pump set. The medium-pressure pump set can lead the oil in the oil tank to the medium-pressure oil supply line. The oil outlet of the medium-pressure oil supply line is connected to the first oil pressure chamber through the medium-pressure PLO port. The low-pressure oil supply device includes a low-pressure pump set and a low-pressure oil supply line. The oil inlet of the low-pressure oil supply line is connected to the low-pressure pump set. The low-pressure pump set can lead the oil in the oil tank to the low-pressure oil supply line. The oil outlet of the low-pressure oil supply line is connected to the second oil pressure chamber. A high-pressure relief control component is provided on the high-pressure oil supply line, a medium-pressure relief control component is provided on the medium-pressure oil supply line, and a low-pressure relief control component is provided on the low-pressure oil supply line.

2. The pressure relief protection servo hydraulic system according to claim 1, characterized in that, The high-pressure relief control component includes a first directional valve and a first safety relief valve designed in parallel. The oil inlets of the first directional valve and the first safety relief valve are connected to the high-pressure oil supply circuit, and the oil outlets of the first directional valve and the first safety relief valve are connected to the oil tank. A first accumulator is also connected to the inlet of the first directional valve.

3. The pressure relief protection servo hydraulic system according to claim 1, characterized in that, A first check valve is provided on the high-pressure oil supply line between the high-pressure relief control component and the high-pressure pump group.

4. The pressure relief protection servo hydraulic system according to claim 2, characterized in that, The outlet of the first directional valve is also connected to a first throttling element.

5. The pressure relief protection servo hydraulic system according to claim 1, characterized in that, The medium-pressure relief control component includes a second directional valve and a second safety relief valve designed in parallel. The oil inlets of the second directional valve and the second safety relief valve are respectively connected to the medium-pressure oil supply circuit, and the oil outlets of the second directional valve and the second safety relief valve are connected to the oil tank. A second accumulator is also connected to the inlet of the second directional valve.

6. The pressure relief protection servo hydraulic system according to claim 5, characterized in that, A second check valve is also provided on the low-pressure oil supply line between the medium-pressure pressure relief control component and the medium-pressure pump group.

7. The pressure relief protection servo hydraulic system according to claim 1, characterized in that, A two-way directional valve assembly is provided between the medium-pressure pressure relief control component and the oil outlet of the medium-pressure oil supply circuit.

8. The pressure relief protection servo hydraulic system according to claim 1, characterized in that, The low-pressure relief control component includes a second directional valve and a second safety relief valve designed in parallel. The oil inlets of the second directional valve and the second safety relief valve are respectively connected to the low-pressure oil supply circuit, and the oil outlets of the second directional valve and the second safety relief valve are connected to the oil tank. A second accumulator is also connected to the inlet of the second directional valve.

9. The pressure relief protection servo hydraulic system according to claim 1, characterized in that, A third check valve and a pressure reducing valve are connected in parallel between the low-pressure relief control component and the oil outlet of the low-pressure oil supply circuit.

10. The pressure relief protection servo hydraulic system according to claim 5 or 8, characterized in that, The outlet of the second directional valve is also connected to a second throttling device.

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