A time-delayed reset gas spring and a time-delay control method

Abstract

This invention relates to the field of gas spring technology, and more particularly to a time-delayed reset gas spring and a time-delay control method. The time-delayed reset gas spring includes a gas spring cylinder, a cylinder base, a piston rod, a piston, and a plunger rod. A normally open switching valve and a signal input valve are disposed within the cavity of the cylinder base. The signal input valve contacts or separates from the normally open switching valve, causing the gas path within the normally open switching valve to close or open, thereby achieving the closure or opening of the gas spring's gas path and achieving the purpose of time-delayed reset. This invention achieves the purpose of time-delayed reset of the gas spring through a normally open switching valve and a signal input valve. Compared to the prior art that achieves time-delayed reset through a control switch, the delay effect of this invention is more controllable, and the normally open switching valve has a good sealing effect, preventing air leakage. Furthermore, during the piston's return stroke, the lower gas flow rate also achieves a slow reset. Therefore, the method of this invention achieves the dual effects of time delay and slow reset.

Description

Technical Field

[0001] This invention relates to the field of gas spring technology, and in particular to a time-delayed reset gas spring and a time-delay control method. Background Technology

[0002] Nitrogen springs are made by sealing high-pressure nitrogen gas in a defined container. External force compresses the nitrogen gas through a piston rod. When the external force is removed, the high-pressure nitrogen gas expands to generate a certain elastic force. They mainly consist of a cylinder, guide seat, sealing ring, O-ring, and piston rod. Nitrogen springs are advantageous due to their small size, high elastic force, long stroke, smooth operation, and precision manufacturing. They can perform tasks that conventional elastic components such as metal springs, rubber, and air cushions cannot, making them a new generation of ideal elastic components with flexible properties. Therefore, they are widely used in the mold industry. When the mold opens, the slider drives the upper mold upwards. Because the upper mold pressure plate has a nitrogen spring, it does not immediately leave the lower mold at the moment of mold opening, but remains pressed against the product until the mold opening stroke reaches the pressure stroke of the upper mold pressure plate before releasing the pressure. At this time, the nitrogen spring on the lower mold pressure plate loses pressure instantaneously and is pushed upwards. Excessive pressure can cause defects such as cracking or reverse bending of the product. Therefore, the nitrogen spring of the lower die pressure plate is usually designed with a delayed reset function. By controlling the delayed release of pressure, the quality of the stamped parts is guaranteed, thereby reducing the scrap rate of the stamped parts.

[0003] In existing technologies, delayed nitrogen springs are typically implemented by adding a control switch and a one-way valve to the cylinder of the nitrogen spring. When a delayed reset is required, the control switch is opened to cut off the gas flow path in the gas circuit. In addition, due to the action of the one-way valve, the gas in the upper gas chamber cannot enter the lower gas chamber. When the mold opening stroke reaches the pressing stroke of the upper mold pressure plate, the control switch is closed, allowing the gas in the lower gas chamber to flow with the gas in the upper gas chamber. The piston rod of the nitrogen spring slowly returns, thereby achieving the purpose of delayed reset.

[0004] However, this delay control method does not provide ideal control over the opening and closing of the nitrogen spring's gas path. It has poor stability and relying solely on the control switch can easily lead to poor sealing at the bottom of the nitrogen spring, resulting in air leakage. This results in poor delay reset performance of the nitrogen spring and a tendency for springback when the mold opens, which in turn affects the quality of the stamped parts. Summary of the Invention

[0005] The purpose of this invention is to provide a delayed reset gas spring and a delayed control method. By setting a normally open switching valve and a signal input valve in the cylinder, the technical problem of delayed reset of the gas spring can be solved.

[0006] To achieve the above objectives, this invention designs a time-delayed reset gas spring, comprising a gas spring cylinder, a cylinder base, a piston rod, a piston, and a plunger rod. The gas spring cylinder has a hollow structure. The piston is disposed within the gas spring cylinder, dividing the cylinder into an upper air chamber and a lower air chamber. The cylinder base is disposed at the bottom of the gas spring cylinder. The piston rod passes through the gas spring cylinder from the outside and connects to the piston. The upper end of the plunger rod is disposed within an air passage communicating with the piston rod and the piston. The lower end of the plunger rod passes through the bottom of the gas spring cylinder and communicates with the cavity of the cylinder base. The air passage communicating with the piston rod, the piston, the plunger rod, and the cylinder base forms a first air path. A second air path communicating with the cavity of the gas spring cylinder is opened on the cylinder base.

[0007] The cylinder base cavity is equipped with a normally open switching valve and a signal input valve. The normally open switching valve is provided with a third air passage and a fourth air passage. The third air passage is connected to the first air passage, and the fourth air passage is connected to the second air passage. The signal input valve is located on the side of the normally open switching valve. One end of the signal input valve is set on the side wall of the cylinder base, and the other end of the signal input valve is set in the cavity of the cylinder base, contacting or separating from the normally open switching valve, so that the third air passage and the fourth air passage of the normally open switching valve are disconnected or connected, thereby realizing the closing or opening of the gas spring air passage and achieving the purpose of delayed reset.

[0008] As a preferred embodiment, the normally open switching valve includes a switching valve cylinder, a dynamic valve, and a static valve. The switching valve cylinder has a hollow structure. The dynamic valve is movably disposed on one side of the cavity of the switching valve cylinder, and the static valve is disposed on the other side of the cavity of the switching valve cylinder. The dynamic valve and the static valve cooperate with each other. A first air hole and a second air hole are opened on the side wall of the switching valve cylinder. The first air hole is connected to the cavity of the cylinder base to form a third air passage. A third air hole is opened on the static valve, and the third air hole is connected to the second air hole to form a fourth air passage.

[0009] As a preferred embodiment, the static valve includes a static core and a mounting part. The static core cooperates with the dynamic valve, and the mounting part is connected to the inner wall of the switching valve cylinder. The third air hole includes a radial air hole and a transverse air hole. The radial air hole is arranged radially on the static core along the switching valve, and the transverse air hole is arranged transversely on the mounting part along the switching valve. The middle part of the transverse air hole communicates with the radial air hole, and the end of the transverse air hole communicates with the second air hole.

[0010] As a preferred embodiment, the side of the static core is provided with a groove along the radial direction of the switching valve, and a vent hole is provided on the side wall of the groove.

[0011] As a preferred embodiment, the dynamic valve includes a core, a valve core push rod, and a valve core plug. The core is a hollow structure with openings at both ends. One side of the core mates with the stationary core, and the other side of the core is in clearance fit with the inner wall of the switching valve cylinder. The valve core plug is made of elastic material and is disposed within the cavity of the core. One end of the valve core plug can extend out of the cavity of the core and seal the radial air hole. One end of the valve core push rod is disposed within the cavity of the core and connected to the valve core plug. The other end of the valve core push rod extends out of the cavity of the core and contacts or separates from the signal input valve.

[0012] As a preferred embodiment, the valve core plug includes a movable part and a sealing part. The movable part is disposed in the cavity of the core body, and the size of the sealing part is smaller than the size of the movable part. The sealing part is provided with a recess that can block the radial air hole.

[0013] As a preferred embodiment, the recess is conical, and the outer diameter of the recess is larger than the diameter of the radial pore.

[0014] As a preferred embodiment, a through hole is formed on the piston along the length of the piston rod, and a one-way valve is installed in the through hole. Gas flows from the lower air chamber of the gas spring through the one-way valve into the upper air chamber to form a fifth gas path.

[0015] This invention also designs a delay control method for a delay-reset gas spring, comprising the following steps:

[0016] S1. External force pushes the piston rod to move towards the bottom of the gas spring cylinder. The gas in the lower chamber enters the upper chamber in sequence through the second, fourth, third, and first gas passages. When the piston contacts the upper end of the cylinder base, it reaches the bottom dead center position. At this time, the pressure in the upper chamber is greater than the pressure in the lower chamber.

[0017] S2. The signal input valve receives a trigger signal, and the valve core of the signal input valve pushes the valve core push rod of the dynamic valve to move, thereby sealing the radial air hole of the static valve with the valve core plug. The normally open switching valve closes, cutting off the gas flow path between the third and fourth air paths, blocking the gas in the upper air chamber from entering the lower air chamber in sequence through the first, third, fourth, and second air paths. The pressure in the upper air chamber is greater than the pressure in the lower air chamber, thereby locking the piston.

[0018] S3. When the trigger signal is closed, the valve core of the signal input valve retracts, the valve core push rod of the dynamic valve returns to its initial state, the valve core plug separates from the radial air hole of the static valve, the normally open switching valve returns to the open state, and gas flows between the third and fourth air paths. The gas in the upper air chamber enters the lower air chamber sequentially through the first, third, fourth, and second air paths. Because the width of the second air path is smaller than the width of the first air path, the gas flow rate decreases, and the piston slowly resets under the action of the gas pressure difference between the upper and lower air chambers.

[0019] Preferably, in step S1, when the piston rod moves toward the cylinder base, the one-way valve on the piston opens, and the gas in the lower chamber directly enters the upper chamber through the fifth gas passage; when the piston moves to the bottom dead center, the one-way valve closes, blocking the gas in the upper chamber from entering the lower chamber through the fifth gas passage, further locking the piston based on step S2; in step S3, the piston drives the piston rod to reset under the action of the gas pressure difference between the upper and lower chambers. At this time, the one-way valve is still in the closed state, continuing to block the gas in the upper chamber from entering the lower chamber through the fifth gas passage, thereby achieving the purpose of slowly resetting the piston rod.

[0020] The beneficial effects of this invention are:

[0021] The gas spring of this invention has a normally open switching valve and a signal input valve installed in the cavity of the cylinder base. The signal input valve is used to trigger the closing and opening of the normally open switching valve. The cavity of the gas spring cylinder has a first gas path and a second gas path, and the normally open switching valve has a third gas path and a fourth gas path. The third gas path is connected to the first gas path, and the fourth gas path is connected to the second gas path. The signal input valve receives a trigger signal, causing its valve core to actuate and close the normally open switching valve, thereby cutting off the gas flow path between the third and fourth gas paths, locking the piston, and achieving the purpose of delayed reset of the gas spring. When the trigger signal closes, the valve core of the signal input valve retracts, causing the normally open switching valve to return to the open state, allowing gas flow in the third and fourth gas paths, and the piston begins its return stroke. Because the gas flow velocity is low during the return, the gas spring achieves a slow reset. Therefore, this invention has a good delay effect, solves the problem of rapid rebound of nitrogen springs in traditional technology, helps improve product quality, and can achieve no rebound phenomenon of the elastic element when the mold opens, ensuring product quality and solving the technical problem of delayed reset of gas springs.

[0022] This invention achieves delayed reset of the gas spring through a normally open switching valve and a signal input valve. Compared to the prior art that uses a control switch to achieve delayed reset, the delay effect of this invention is more controllable, and the normally open switching valve has a good sealing effect, preventing air leakage. Furthermore, during the piston's return stroke, the low gas flow rate allows for a slow reset. Therefore, the method of this invention achieves the dual effects of delayed reset and slow reset. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural diagram of a time-delay reset gas spring;

[0024] Figure 2 This is a cross-sectional schematic diagram of a time-delayed reset gas spring;

[0025] Figure 3 This is a schematic diagram of the delayed reset gas spring closing process;

[0026] Figure 4This is a schematic diagram of the delayed reset gas spring in the locked state.

[0027] Figure 5 This is a schematic diagram of the delayed reset gas spring reset process;

[0028] Figure 6 Schematic diagram of the normally open switching valve in the open state;

[0029] Figure 7 This is a schematic diagram of the normally open switching valve in the closed state.

[0030] Figure 8 This is a sectional view of the switching valve cylinder.

[0031] Figure 9 This is a cross-sectional view of a dynamic valve;

[0032] Figure 10 This is a cross-sectional view of a static valve.

[0033] Explanation of reference numerals in the attached figures:

[0034] Gas spring cylinder body 1, cylinder base 2, limit sleeve 3, piston rod 4, piston 5, through hole 6, one-way valve 7, plunger rod 8, upper air chamber 9, lower air chamber 10, first air passage 11, second air passage 12, fifth air passage 13, normally open switching valve 14, signal input valve 15, third air passage 16, fourth air passage 17, switching valve cylinder body 18, dynamic valve 19, static valve 20, first air hole 21, second air hole 22, third air hole 23, radial air hole 24, transverse air hole 25, stationary core part 26, mounting part 27, groove 28, vent hole 29, core body 30, valve core push rod 31, valve core plug 32, moving part 33, sealing part 34, recess 35. Detailed Implementation

[0035] To make the technical problems solved by this invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of this invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining this invention and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this invention are shown in the accompanying drawings, not all of them.

[0036] In the description of this invention, 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 the invention 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 blocking the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0038] This invention relates to a delayed-reset gas spring and a delayed-reset control method. The delayed-reset gas spring is achieved through a normally open switching valve 14 and a signal input valve 15. Compared to existing technologies that use a control switch for delayed reset, this invention offers better controllability of the delay effect. Furthermore, the normally open switching valve 14 provides excellent sealing, preventing air leakage. Additionally, during the piston 5's return stroke, the low gas flow rate allows for a slow reset. Therefore, this invention achieves the dual effects of delayed reset and slow reset. The cylinder of the gas spring is filled with nitrogen gas at a certain pressure. The cylinder is sealed at both ends by a cylinder base 2, a limiting sleeve 3, and a piston rod 4 passing through the limiting sleeve, along with a sealing element. The piston 5 within the cylinder divides the gas into an upper chamber 9 and a lower chamber 10. A one-way valve 7 is installed inside the piston 5 to block the gas flow direction. When the signal input valve receives a control signal, the normally open switching valve activates, allowing the delayed-reset nitrogen spring to lock the piston through the pressure difference between the upper and lower chambers, thus delaying the stroke and meeting the specific requirements of stamping dies.

[0039] Specifically, such as Figure 1 , Figure 2As shown, this invention relates to a time-delayed reset gas spring, comprising a gas spring cylinder 1, a cylinder base 2, a piston rod 4, a piston 5, and a plunger rod 8. The gas spring cylinder 1 is a hollow structure. The piston 5 is disposed inside the gas spring cylinder 1, dividing the cylinder into an upper air chamber 9 and a lower air chamber 10. The cylinder base 2 is disposed at the bottom of the gas spring cylinder 1. The piston rod 4 passes through the gas spring cylinder 1 from the outside and is connected to the piston. The upper end of the plunger rod 8 is disposed in an air passage communicating with the piston rod 4 and the piston 5. The lower end of the plunger rod 8 is disposed on the cylinder base 2. The air passage of the plunger rod 8 communicates with the cavity of the cylinder base 2. The air passage communicating with the piston rod 4, the piston 5, the plunger rod 8, and the cylinder base 2 forms a first air passage 11. A second air passage 12 communicating with the cavity of the gas spring cylinder 1 is opened on the cylinder base 2. The width of the second air passage 12 is narrower than the width of the first air passage 11.

[0040] The cylinder base 2 is provided with a normally open switching valve 14 and a signal input valve 15 inside the cavity. The normally open switching valve 14 is provided with a third air passage 16 and a fourth air passage 17. The third air passage 16 is connected to the first air passage 11, and the fourth air passage 17 is connected to the second air passage 12. The signal input valve 15 is located on the side of the normally open switching valve 14. One end of the signal input valve 15 is set on the side wall of the cylinder base 2, and the other end of the signal input valve 15 is set inside the cavity of the cylinder base 2, contacting or separating from the normally open switching valve 14, so that the third air passage 16 and the fourth air passage 17 of the normally open switching valve 14 are disconnected or connected, thereby realizing the closing or opening of the gas spring air passage and achieving the purpose of delayed reset.

[0041] The gas spring cylinder 1 is used to store pressurized gas. The lower end of the gas spring cylinder 1 is connected to the cylinder base 2 by a thread, and the upper end of the gas spring cylinder 1 is locked with the limiting sleeve 3 by a spring slot. The pressurized gas filled in the gas spring cylinder 1 is isolated into an upper gas chamber and a lower gas chamber by the piston 5. The pressure difference formed in the gas spring cylinder 1 causes the piston 5 to move upward and return.

[0042] The upper end of the cylinder base 2 is connected to the lower end of the gas spring cylinder 1 via threads. The thread seal is achieved by a sealing ring on the cylinder base, and the thread anti-loosening is achieved by an anti-loosening plug on the cylinder base 2. A plug is installed at the lower end of the cylinder base 2 to prevent gas leakage from the bottom of the cavity. The cavity of the cylinder base 2 is equipped with a signal input valve 15 and a normally open switching valve 14. A plunger rod 8 is installed on the upper end face of the cylinder base 2, and the air passage in the middle of the plunger rod 8 connects the cavity of the cylinder base 2 and the upper air chamber.

[0043] The delayed reset gas spring also includes a limiting sleeve 3 and various seals, support rings, fasteners, and elastic elements. The limiting sleeve 3 is located at the top of the cavity of the gas spring cylinder 1 to prevent the piston rod 4 from disengaging from the gas spring cylinder 1 during return. The limiting sleeve 3 is installed at the upper end of the gas spring cylinder 1 and is fixed to the upper end of the gas spring cylinder 1 by a steel wire retaining ring. The seal between the limiting sleeve 3 and the gas spring cylinder 1 is achieved by the limiting sleeve sealing ring. An outer dustproof ring is installed between the limiting sleeve 3 and the port of the gas spring cylinder 1 to prevent dust and oil from entering.

[0044] The piston rod 4 is installed on the upper end of the piston 5 via a threaded connection and reciprocates under the drive of the piston 5. A dustproof ring, a support ring, and a sealing ring are installed on the sliding surface of the piston rod 4 to prevent external dust from entering during its movement, ensure smooth sliding of the piston rod 4, and maintain gas tightness. The lower end of the piston rod 4 has an air passage that connects to the upper air chamber and the cavity of the cylinder base 2 via the air passage in the center of the plunger rod.

[0045] Piston 5 is installed inside the gas spring cylinder 1. An upper air chamber is formed between piston 5 and limiting sleeve 3, and a lower air chamber is formed between piston 5 and cylinder base 2. The upper end of the center of piston 5 is connected to piston rod 4 by a thread, and the lower end of the center of piston 5 passes through plunger rod 8. The air passages on piston rod 4 and plunger rod 8 connect the upper air chamber and the cavity of cylinder base 2. Air passages connecting the upper and lower air chambers are evenly distributed on piston 5, and a one-way valve 7 is installed in the middle of the air passage to block the flow of gas. A piston support ring and a piston sealing ring are installed on the sliding surface of piston 5 to ensure that the piston can slide smoothly and seal the gas during movement. Piston 5 moves relative to gas spring cylinder 1. A through hole 6 is opened on piston 5 along the length of piston rod 4. A one-way valve 7 is installed in the through hole 6. Gas flows from the lower air chamber 10 of the gas spring into the upper air chamber 9 through the one-way valve 7 to form the fifth air passage 13.

[0046] One-way valve 7 is installed in the evenly distributed air passages on piston 5. Gas in the lower air chamber can pass to the upper air chamber. Gas in the upper air chamber is blocked by one-way valve 7, so that gas in the upper air chamber can only enter the normally open switching valve 14 through the air passages of piston rod 4 and plunger rod 8.

[0047] The upper end of the plunger rod 8 passes through the piston 5. Under the action of pressurized gas, the piston 5 moves up and down along the plunger rod 8. The upper sealing ring, the plunger rod support ring, and the lower sealing ring of the plunger rod ensure that the plunger rod 8 and the piston 5 can slide smoothly and seal against the gas during the movement. The plunger rod plug locks the plunger rod to the cylinder base.

[0048] The signal input valve 15 is fixed within the cylinder base cavity 2, mounted on the input valve support ring. The input valve support ring and the input valve push rod form an air chamber within the cylinder base cavity 2. The pressure signal from the external input air chamber drives the input valve push rod, transmitting the signal to the valve core push rod. The input valve sealing ring achieves a seal with the cylinder base cavity 2. The signal input valve 15 includes a valve core and a pusher. The valve core cooperates with the normally open switching valve 14, and the pusher is connected to an external trigger signal. The signal input valve 15 receives a pneumatic signal provided by the press control system or the stamping die structure design. The air passage of the normally open switching valve and the cylinder base air passage are opened or closed via the signal input valve 15, thereby controlling the gas conversion within the gas spring cylinder. The gas conversion method involves a pneumatic signal provided by the press control system or the stamping die structure design, which is input through the signal input valve 15 to trigger the normally open switching valve 14 for logic control.

[0049] like Figures 6 to 10 As shown, the normally open switching valve 14 is installed in the cavity of the cylinder base 2. The normally open switching valve 14 contains a stationary valve core, which is installed in the normally open switching valve 14 by a steel wire retaining ring. The valve core push rod is fixed in the normally open switching valve 14 by a valve core support ring. The valve core sealing ring prevents gas from leaking through the valve core push rod. The helical spring installed on the stationary valve core acts on the valve core push rod to reset it after movement. The switching valve cylinder sealing ring achieves the seal between the normally open switching valve 14 and the cylinder base 2. The normally open switching valve 14 includes a switching valve cylinder 18, a dynamic valve 19, and a static valve 20. The switching valve cylinder 18 has a hollow structure. The dynamic valve 19 is movably disposed on one side of the cavity of the switching valve cylinder 18, and the static valve 20 is disposed on the other side of the cavity of the switching valve cylinder 18. The dynamic valve 19 and the static valve 20 cooperate with each other. A first air hole 21 and a second air hole 22 are opened on the side wall of the switching valve cylinder 18. The first air hole 21 is connected to the cavity of the cylinder base 2 to form a third air passage 16. A third air hole 23 is opened on the static valve 20. The third air hole 23 is connected to the second air hole 22 to form a fourth air passage 17.

[0050] The static valve 20 includes a stationary core 26 and a mounting part 27. The stationary core 26 cooperates with the dynamic valve 19, and the mounting part 27 is connected to the inner wall of the switching valve cylinder 18. The third vent 23 includes a radial vent 24 and a transverse vent 25. The radial vent 24 is radially disposed on the stationary core 26 along the switching valve, and the transverse vent 25 is transversely disposed on the mounting part 27 along the switching valve. The middle part of the transverse vent 25 communicates with the radial vent 24, and the end of the transverse vent 25 communicates with the second vent 22. The side of the stationary core 26 has a groove 28 radially disposed on the switching valve, and a vent 29 is formed on the side wall of the groove 28. The axis of the vent 29 is perpendicular to the axis of the transverse vent 25.

[0051] The dynamic valve 19 includes a core 30, a valve core push rod 31, and a valve core plug 32. The core 30 is a hollow structure with openings at both ends. One side of the core 30 is fitted with the stationary core 26, and the other side of the core 30 is fitted with the inner wall of the switching valve cylinder 18 with clearance. The valve core plug 32 is made of elastic material and is disposed in the cavity of the core 30. One end of the valve core plug 32 can extend out of the cavity of the core 30 and seal the radial air hole 24. One end of the valve core push rod 31 is disposed in the cavity of the core 30 and connected to the valve core plug 32. The other end of the valve core push rod 31 extends out of the cavity of the core 30 and contacts or separates from the signal input valve 15.

[0052] The valve core plug 32 includes a movable part 33 and a sealing part 34. The movable part 33 is disposed in the cavity of the core body 30. The size of the sealing part 34 is smaller than that of the movable part 33. The sealing part 34 is provided with a recess 35 that can block the radial air hole 24. The recess 35 is conical, and the outer diameter of the recess 35 is larger than the diameter of the radial air hole 24.

[0053] This invention also relates to a delay control method for a delay-reset gas spring, comprising the following steps:

[0054] S1. External force pushes piston rod 4 to move towards the bottom of gas spring cylinder 1. Gas in lower chamber 10 enters upper chamber 9 through second gas passage 12, fourth gas passage 17, third gas passage 16, and first gas passage 11 in sequence. When piston 5 contacts the upper end of cylinder base 2, it reaches the bottom dead center position. At this time, the pressure in upper chamber 9 is greater than the pressure in lower chamber 10.

[0055] In step S1, when the piston rod 4 moves toward the cylinder base 2, the one-way valve 7 on the piston 5 opens, and the gas in the lower air chamber 10 directly enters the upper air chamber 9 through the fifth air passage 13.

[0056] S2. Signal input valve 15 receives a trigger signal. The valve core of signal input valve 15 pushes the valve core push rod 31 of dynamic valve 19 to move, thereby causing valve core plug 32 to seal the radial air hole 24 of static valve 20. Normally open switching valve 14 closes, cutting off the gas flow path between the third air passage 16 and the fourth air passage 17, blocking the gas in upper air chamber 9 from entering lower air chamber 10 in sequence through first air passage 11, third air passage 16, fourth air passage 17, and second air passage 12. The pressure in upper air chamber 9 is greater than the pressure in lower air chamber 10, thereby locking piston 5.

[0057] When the piston moves to the bottom dead center, the one-way valve 7 closes, blocking the gas in the upper air chamber 9 from entering the lower air chamber 10 through the fifth air passage 13, and further locking the piston 5 based on step S2;

[0058] S3. When the trigger signal is closed, the valve core of the signal input valve 15 retracts, the valve core push rod 31 of the dynamic valve 19 returns to its initial state, the valve core plug 32 separates from the radial air hole 24 of the static valve 20, the normally open switching valve 14 returns to the open state, and the gas flows between the third air passage 16 and the fourth air passage 17. The gas in the upper air chamber 9 enters the lower air chamber 10 in sequence through the first air passage 11, the third air passage 16, the fourth air passage 17, and the second air passage 12. Because the width of the second air passage 12 is smaller than the width of the first air passage 11, the gas flow rate decreases, and the piston 5 drives the piston rod 4 to slowly reset under the action of the gas pressure difference between the upper and lower air chambers.

[0059] In step S3, piston 5 drives piston rod 4 to reset under the action of gas pressure difference between the upper and lower air chambers. At this time, one-way valve 7 is still in the closed state, which continues to block the gas in upper air chamber 9 from entering lower air chamber 10 through fifth air passage 13, thereby achieving the purpose of slow resetting of piston rod 4.

[0060] like Figure 3 As shown, when the delayed nitrogen spring is compressed, the piston rod 4 is subjected to pressure and moves downward, and the piston 5 moves downward from the initial position. The nitrogen in the cylinder enters the upper air chamber 9 from the lower air chamber 10 through the one-way valve 7 installed on the piston 5, so that all the air passages entering the upper air chamber 9 are open, and the gas can smoothly enter the upper air chamber 9.

[0061] like Figure 4 As shown, when piston 5 reaches the bottom dead center, check valve 7 closes, and the air path on piston 5 prevents gas in upper chamber 9 from returning to lower chamber 10. Signal input valve 15, which controls the return stroke node of piston 5, triggers normally open switching valve 14. Normally open switching valve 14 is closed under pressure greater than 0.4 MPa, thereby closing another air path for gas to return to lower chamber 10. At this time, all air paths are closed, gas is prohibited from entering lower chamber 10, the pressure in upper chamber is greater than the pressure in lower chamber, and piston is locked at the bottom dead center, realizing the return stroke locking function.

[0062] like Figure 5As shown, when the signal input valve 15 triggers the normally open switching valve 14 again, the normally open switching valve 14 changes from the closed state to the open state. At this time, only the air path of the normally open switching valve 14 is opened, while the one-way valve 7 remains closed because the one-way valve 7 is only opened when the piston moves downward. The nitrogen in the upper air chamber 9 returns to the lower air chamber 10 through the cavity of the plunger rod 8 and the normally open switching valve 14. The piston rod 4 also begins to slowly return from the bottom dead center to the top dead center position. In addition, the width of the second air path 12 is narrower than the width of the first air path 11, thereby blocking the flow rate of the gas return and making the return return slow, realizing the return delay reset function. When the pressure of the delayed nitrogen spring is released, the piston rod 4 will not immediately return to the top dead center position, thus playing a role in controlling the delay of the nitrogen spring. The delay in the return stroke of the delayed nitrogen spring is controlled by the normally open switching valve triggered by the air pressure signal received from the stamping die by the signal input valve, realizing the logical control of the stamping die rhythm on the delayed nitrogen spring.

[0063] When the delayed nitrogen spring operates without signal input valve 15 triggering the normally open switching valve 14, its operation is the same as that of a regular nitrogen spring and a mechanical coil spring. When the piston rod 4 is subjected to external pressure, it will be pushed back into the cylinder according to the set safety stroke. The gas pressure inside the cylinder then acts on the piston rod 4, causing it to return to its initial state. Only when the delayed nitrogen spring receives a control signal through signal input valve 15 can it trigger the normally open switching valve 14 to start working. Only then can the delayed nitrogen spring lock the piston 5, achieving the purpose of stroke delay reset and meeting the special requirements of the stamping die. The timing of the delay function is achieved through the input air pressure signal provided by the press control system or the stamping die structure design.

[0064] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A time-delayed reset gas spring, comprising a gas spring cylinder (1), a cylinder base (2), a piston rod (4), a piston (5), and a plunger rod (8), wherein the gas spring cylinder (1) is a hollow structure, the piston (5) is disposed inside the gas spring cylinder (1) and divides the cylinder into an upper air chamber (9) and a lower air chamber (10), the cylinder base (2) is disposed at the bottom of the gas spring cylinder (1), the piston rod (4) passes through the gas spring cylinder (1) from the outside and is connected to the piston, the upper end of the plunger rod (8) is disposed in the air passage connecting the piston rod (4) and the piston (5), the lower end of the plunger rod (8) passes through the bottom of the gas spring cylinder (1) and is connected to the cavity of the cylinder base (2), the air passage connecting the piston rod (4), the piston (5), the plunger rod (8), and the cylinder base (2) forms a first air passage (11), and a second air passage (12) is opened on the cylinder base (2) and is connected to the cavity of the gas spring cylinder (1); Its features are: The cylinder base (2) is provided with a normally open switching valve (14) and a signal input valve (15) in its cavity. The normally open switching valve (14) is provided with a third air passage (16) and a fourth air passage (17). The third air passage (16) is connected to the first air passage (11), and the fourth air passage (17) is connected to the second air passage (12). The signal input valve (15) is located on the side of the normally open switching valve (14). One end of the signal input valve (15) is set on the side wall of the cylinder base (2), and the other end of the signal input valve (15) is set in the cavity of the cylinder base (2) to contact or separate from the normally open switching valve (14), so that the third air passage (16) and the fourth air passage (17) of the normally open switching valve (14) are disconnected or connected, thereby realizing the closing or opening of the gas spring air passage and achieving the purpose of delayed reset. The normally open switching valve (14) includes a switching valve cylinder (18), a dynamic valve (19), and a static valve (20). The switching valve cylinder (18) is a hollow structure. The dynamic valve (19) is movably disposed on one side of the cavity of the switching valve cylinder (18), and the static valve (20) is disposed on the other side of the cavity of the switching valve cylinder (18). The dynamic valve (19) and the static valve (20) cooperate with each other. A first air hole (21) and a second air hole (22) are opened on the side wall of the switching valve cylinder (18). The first air hole (21) is connected to the cavity of the cylinder base (2) to form a third air passage (16). A third air hole (23) is opened on the static valve (20). The third air hole (23) is connected to the second air hole (22) to form a fourth air passage (17). The static valve (20) includes a static core (26) and a mounting part (27). The static core (26) cooperates with the dynamic valve (19). The mounting part (27) is connected to the inner wall of the switching valve cylinder (18). The third air hole (23) includes a radial air hole (24) and a transverse air hole (25). The radial air hole (24) is arranged radially on the static core (26) along the switching valve. The transverse air hole (25) is arranged transversely on the mounting part (27) along the switching valve. The middle part of the transverse air hole (25) communicates with the radial air hole (24). The end of the transverse air hole (25) communicates with the second air hole (22). The dynamic valve (19) includes a core (30), a valve core push rod (31), and a valve core plug (32). The core (30) is a hollow structure with openings at both ends. One side of the core (30) is fitted with the stationary core (26), and the other side of the core (30) is fitted with the inner wall of the switching valve cylinder (18) with a clearance. The valve core plug (32) is made of elastic material and is set in the cavity of the core (30). One end of the valve core plug (32) can extend out of the cavity of the core (30) and seal the radial air hole (24). One end of the valve core push rod (31) is set in the cavity of the core (30) and connected to the valve core plug (32). The other end of the valve core push rod (31) extends out of the cavity of the core (30) and contacts or separates from the signal input valve (15). The valve core plug (32) includes a movable part (33) and a sealing part (34). The movable part (33) is located in the cavity of the core body (30). The size of the sealing part (34) is smaller than that of the movable part (33). The sealing part (34) is provided with a recess (35) that can block the radial air hole (24).

2. The time-delayed reset gas spring according to claim 1, characterized in that: The side of the static core (26) is provided with a groove (28) along the radial direction of the switching valve, and a vent hole (29) is opened on the side wall of the groove (28).

3. The time-delayed reset gas spring according to claim 2, characterized in that: The recess (35) is conical, and the outer diameter of the recess (35) is larger than the diameter of the radial pore (24).

4. The time-delayed reset gas spring according to any one of claims 1 to 3, characterized in that: A through hole (6) is opened on the piston (5) along the length direction of the piston rod (4). A one-way valve (7) is installed in the through hole (6). Gas flows from the lower air chamber (10) of the gas spring into the upper air chamber (9) through the one-way valve (7) to form the fifth gas path (13).

5. A delay control method for a delay-reset gas spring, characterized in that: The method applicable to the time-delayed reset gas spring of claim 1 includes the following steps: S1. External force pushes the piston rod (4) to move towards the bottom of the gas spring cylinder (1). The gas in the lower air chamber (10) enters the upper air chamber (9) in sequence through the second air passage (12), the fourth air passage (17), the third air passage (16), and the first air passage (11). When the piston (5) contacts the upper end of the cylinder base (2), it reaches the bottom dead center position. At this time, the pressure in the upper air chamber (9) is greater than the pressure in the lower air chamber (10). S2. The signal input valve (15) receives the trigger signal. The valve core of the signal input valve (15) pushes the valve core push rod (31) of the dynamic valve (19) to move, thereby causing the valve core plug (32) to seal the radial air hole (24) of the static valve (20). The normally open switching valve (14) closes, cutting off the gas flow path between the third air path (16) and the fourth air path (17), blocking the gas in the upper air chamber (9) from entering the lower air chamber (10) in sequence through the first air path (11), the third air path (16), the fourth air path (17), and the second air path (12). The pressure in the upper air chamber (9) is greater than the pressure in the lower air chamber (10), thereby locking the piston (5). S3. When the trigger signal is closed, the valve core of the signal input valve (15) retracts, the valve core push rod (31) of the dynamic valve (19) returns to the initial state, the valve core plug (32) separates from the radial air hole (24) of the static valve (20), the normally open switching valve (14) returns to the open state, the gas flows between the third air path (16) and the fourth air path (17), the gas in the upper air chamber (9) enters the lower air chamber (10) in sequence through the first air path (11), the third air path (16), the fourth air path (17), and the second air path (12). Because the width of the second air path (12) is smaller than the width of the first air path (11), the gas flow rate decreases, and the piston (5) drives the piston rod (4) to slowly reset under the action of the gas pressure difference between the upper and lower air chambers.

6. The delay control method for the delay-reset gas spring according to claim 5, characterized in that: In step S1, when the piston rod (4) moves toward the cylinder base (2), the one-way valve (7) on the piston (5) opens, and the gas in the lower air chamber (10) directly enters the upper air chamber (9) through the fifth air passage (13). When the piston moves to the bottom dead center, the one-way valve (7) closes, blocking the gas in the upper air chamber (9) from entering the lower air chamber (10) through the fifth air passage (13), and further locking the piston (5) on the basis of step S2. In step S3, the piston (5) drives the piston rod (4) to reset under the action of the gas pressure difference between the upper and lower air chambers. At this time, the one-way valve (7) is still in the closed state, continuing to block the gas in the upper air chamber (9) from entering the lower air chamber (10) through the fifth air passage (13), thereby achieving the purpose of slowly resetting the piston rod (4).

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