Delayed return nitrogen spring

Abstract

This utility model relates to the field of nitrogen spring technology, and in particular to a delayed return nitrogen spring, comprising a cylinder, a piston rod, a piston plate, an overflow valve, a return valve, an inflation valve, and a guide sleeve. The cylinder has an inner cavity and an outer cavity. The inner cavity has an insert hole, a sliding hole, and a connecting hole connected sequentially from top to bottom. The connecting hole of the inner cavity is connected to the bottom end of the outer cavity via the overflow valve or the return valve. The inflation valve is embedded in the bottom of the cylinder and communicates with the inner cavity. The guide sleeve is installed in the insert hole. The piston rod slides through the guide sleeve. The piston plate is installed at the bottom end of the piston rod and moves within the sliding hole. There is a gap between the peripheral sidewall of the piston plate and the inner sidewall of the sliding hole. A limiting step is formed between the sliding hole and the connecting hole, and the limiting step is used to abut the bottom surface of the piston plate. This application can realize the delayed return and reset of the piston rod and piston plate, and can control the time of the delayed return, effectively eliminating the impact on external products and components caused by the instantaneous upward rebound of the piston rod in existing nitrogen springs.

Description

Technical Field

[0001] This utility model relates to the field of nitrogen spring technology, and in particular to a delayed return nitrogen spring. Background Technology

[0002] Nitrogen springs are an indispensable component in stamping die design, offering advantages such as light weight, long service life, adjustable spring force and stroke, and easy operation and maintenance. However, because the return force release process of nitrogen springs is similar to that of metal springs, the pressure unloading of nitrogen springs involves the unrestrained release of nitrogen compression energy. Furthermore, due to the pre-compression phenomenon in nitrogen springs, the impact force generated by energy release is very large. This return impact force not only causes the equipment to continue to bear load during unloading, but also, if the recovery speed of the upper pressure plate component in the upper die is less than the impact speed of the nitrogen spring's return stroke, it can damage the formed part. Therefore, achieving a delayed return stroke for the nitrogen spring's piston rod is a difficult technological problem to solve in nitrogen spring die design.

[0003] Among existing patents, Chinese patent application number 202310319061.3 discloses a controllable delayed rebound nitrogen spring, comprising: a cylinder with an open upper part, an upper partition plate inside the cylinder, a first air guide groove on the lower side of the upper partition plate, a third air guide groove on one side of the upper partition plate, the third air guide groove being connected to the first air guide groove, and a connecting pipe second connecting one end of the third air guide groove; a second air guide groove on the lower part of the cylinder, and an inflation valve at one end of the second air guide groove. The second air guide groove is connected to a connecting pipe at its end furthest from the inflation valve. An air inlet is located on the lower side of the cylinder's interior, communicating with the second air guide groove. A dust cover is located on the upper inner side of the cylinder, and a retaining ring is fitted around its outer side. A pressure sensing structure is used to sense pressure and convert the pressure signal into an electrical signal. The pressure sensing structure includes a piezoelectric element, a positive conductive element, a negative conductive element, and an insulating gasket. The positive and negative conductive elements are respectively connected to the upper and lower surfaces of the piezoelectric element, and the insulating gasket is located on the pressure... The upper part of the electrode sheet includes a contact ring assembly that works with the pressure sensing structure to transmit the electrical signal converted by the pressure sensing structure to the controller. The contact ring is located on the upper part of the cylinder. A piston structure is located inside the cylinder, including a piston disc, a piston rod located on the upper part of the piston disc, a guide ring sleeved on the outside of the piston disc, and multiple oil seals. The upper part of the piston rod passes through an upper partition, a dust cover, and the contact ring sequentially. An airflow circuit assembly forms a gas passage outside the cylinder. The airflow circuit assembly is located on the outside of the cylinder. Connecting pipe one and connecting pipe two are respectively connected to the airflow circuit assembly. The airflow circuit assembly includes a shell and an airflow regulating structure. A controller assembly receives signals from the pressure sensing structure and controls the operation of the airflow circuit assembly. The controller assembly is located on the outside of the cylinder and is connected to the pressure sensing structure and the airflow circuit assembly. An L-shaped control air groove is provided on the side of the upper partition away from the first air guide groove. One end of the L-shaped control air groove penetrates the cylinder and is internally threaded with a sealing column. This patent document uses a single-cavity structure to achieve delayed rebound. Utility Model Content

[0004] In order to solve the above-mentioned technical problems, the purpose of this utility model is to provide a delayed return nitrogen spring.

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

[0006] The delayed return nitrogen spring includes a cylinder, a piston rod, a piston plate, an overflow valve, a return valve, an inflation valve, and a guide sleeve. The cylinder has an inner cavity and an outer cavity arranged sequentially from the inside out. The inner cavity has an insert hole, a sliding hole, and a connecting hole arranged sequentially from top to bottom. The overflow valve and the return valve are both embedded in the bottom of the cylinder. The connecting hole of the inner cavity is connected to the bottom end of the outer cavity via the overflow valve. The overflow valve controls the flow of nitrogen from the inner cavity to the outer cavity. The bottom end of the outer cavity is connected to the connecting hole of the inner cavity via the return valve. The return valve controls the return flow of nitrogen from the outer cavity to the inner cavity. The inflation valve is embedded in the bottom of the cylinder and connected to the inner cavity. The guide sleeve is installed in the insert hole. The piston rod slides through the guide sleeve. The piston plate is installed at the bottom end of the piston rod and is movable within the sliding hole. There is a gap between the peripheral wall of the piston plate and the inner wall of the sliding hole. A limiting step is formed between the sliding hole and the connecting hole, and the limiting step abuts against the bottom surface of the piston plate.

[0007] Furthermore, the inner wall of the guide sleeve is fitted with a sealing ring and a guide ring, and the plug rod slides through the sealing ring and the guide ring.

[0008] Furthermore, an air flow control valve is installed inside the outer cavity, and the outer cavity is connected to the return valve via the air flow control valve.

[0009] Furthermore, the bottom wall of the inner cavity is equipped with an abutment block, which is located inside the connecting hole and is used to abut the bottom surface of the piston plate.

[0010] Furthermore, the contact block has a vent hole, and the two ends of the vent hole are connected to an inflation valve and a sliding hole, respectively.

[0011] Furthermore, the contact block is a rubber pad.

[0012] Furthermore, the cylinder body includes an inner cylinder, an outer cylinder spaced outside the inner cylinder, a top cover installed at the top of the inner cylinder and the top of the outer cylinder, and a bottom plate installed at the bottom of the inner cylinder and the bottom of the outer cylinder. The inner hole of the inner cylinder forms an inner cavity, and the outer side wall of the inner cylinder and the inner side wall of the outer cylinder form an outer cavity. The inflation valve is embedded in the bottom plate.

[0013] Furthermore, a dustproof ring is provided between the top cover, guide sleeve, and plug rod, and the plug rod slides through the dustproof ring.

[0014] Furthermore, sealing rings are provided between the inner cylinder and the top cover, between the outer cylinder and the top cover, between the inner cylinder and the bottom plate, between the outer cylinder and the bottom plate, and between the guide sleeve and the inner cylinder.

[0015] Furthermore, a load valve is embedded in the base plate.

[0016] The beneficial effects of this utility model are as follows: In practical applications, nitrogen gas is injected into the inner cavity through the filling valve, causing the piston plate and piston rod to move upward until the top surface of the piston plate contacts the bottom surface of the guide sleeve, thus completing the nitrogen filling process. When the top of the piston rod is subjected to downward pressure, the piston plate and piston rod move downward. As the volume of the piston rod extending into the sliding hole increases, the nitrogen gas in the inner cavity is gradually compressed, causing the gas pressure in the inner cavity to increase. When the gas pressure in the inner cavity reaches the control pressure value of the overflow valve, the overflow valve opens, and the nitrogen gas in the inner cavity flows to the outer cavity through the overflow valve, causing the nitrogen gas in the outer cavity to... The air pressure gradually increases until the bottom surface of the piston plate contacts the limiting step, at which point the piston plate and piston rod stop moving downwards, ending the working stroke. At this point, the overflow valve closes, and there is no reaction force from the compressed nitrogen on the bottom surface of the piston plate, keeping it stationary. After the downward pressure on the top of the piston rod is released, the piston plate and piston rod will not return to their original position. When the piston plate needs to return to its original position, the return valve is opened, allowing the compressed nitrogen in the outer cavity to flow back into the inner cavity, causing the piston plate and piston rod to move upwards until the top surface of the piston plate contacts the bottom surface of the guide sleeve, at which point the return valve closes. This invention enables delayed return and reset of the piston rod and piston plate, and allows control over the timing of the delayed return and reset, effectively eliminating the impact on external products and components caused by the rapid return and reset of the piston rod when the compression energy (rebound force) of the nitrogen spring is released instantaneously. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the present invention.

[0018] Explanation of reference numerals in the attached figures:

[0019] 1. Cylinder body; 2. Plug rod; 3. Piston plate; 4. Overflow valve; 5. Return valve; 6. Inflation valve; 7. Guide sleeve; 8. Inner cavity; 9. Outer cavity; 10. Limiting step; 11. Sealing ring; 12. Guide ring; 13. Air flow control valve; 14. Contact block; 15. Vent hole; 16. Inner cylinder; 17. Outer cylinder; 18. Top cover; 19. Base plate; 20. Dustproof ring; 21. Sealing ring. Detailed Implementation

[0020] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0021] like Figure 1As shown, the delayed return nitrogen spring provided by this utility model includes a cylinder body 1, a piston rod 2, a piston plate 3, an overflow valve 4, a return valve 5, a charging valve 6, and a guide sleeve 7. The cylinder body 1 has an inner cavity 8 and an outer cavity 9 arranged sequentially from the inside to the outside. The inner cavity 8 has an insert hole, a sliding hole, and a connecting hole arranged sequentially from top to bottom. The overflow valve 4 and the return valve 5 are both embedded in the bottom of the cylinder body 1. The connecting hole of the inner cavity 8 is connected to the bottom end of the outer cavity 9 via the overflow valve 4. The overflow valve 4 is used to control the flow of nitrogen from the inner cavity 8 to the outer cavity 9. The bottom end of 9 is connected to the connecting hole of the inner cavity 8 via the return valve 5. The return valve 5 is used to control the return of nitrogen in the outer cavity 9 to the inner cavity 8. The inflation valve 6 is embedded in the bottom of the cylinder body 1 and is connected to the inner cavity 8. The guide sleeve 7 is installed in the mounting hole. The piston rod 2 slides through the guide sleeve 7. The piston plate 3 is installed at the bottom end of the piston rod 2. The piston plate 3 is moved and set in the sliding hole. There is a gap between the peripheral side wall of the piston plate 3 and the inner side wall of the sliding hole. A limiting step 10 is formed between the sliding hole and the connecting hole. The limiting step 10 is used to abut the bottom surface of the piston plate 3.

[0022] In practical applications, nitrogen gas is injected into the inner cavity 8 via the filling valve 6, causing the stopper rod 2 and piston plate 3 to move upwards until the top surface of the piston plate 3 contacts the bottom surface of the guide sleeve 7, thus completing the nitrogen filling process of this invention. When the top of the stopper rod 2 is subjected to downward compressive force, the stopper rod 2 and piston plate 3 move downwards. As the volume of the stopper rod 2 extending into the sliding hole increases, the nitrogen gas in the inner cavity 8 is gradually compressed, causing the gas pressure in the inner cavity 8 to increase. When the gas pressure in the inner cavity 8 reaches the control pressure value of the overflow valve 4, the overflow valve 4 opens, and the nitrogen gas in the inner cavity 8 flows to the outer cavity 9 through the overflow valve 4, causing the gas pressure in the outer cavity 9 to gradually increase. The piston plate 3 and piston rod 2 stop moving downwards until the bottom surface of the piston plate 3 contacts the limiting step 10, ending the working stroke. At this point, the overflow valve 4 is closed, and there is no reaction force from the compressed nitrogen on the bottom surface of the piston plate 3, keeping the piston plate 3 stationary. After the downward pressure on the top of the piston rod 2 is released, the piston plate 3 and piston rod 2 will not return to their original position. When the piston plate 3 needs to return to its original position, the return valve 5 is opened, allowing the compressed nitrogen in the outer cavity 9 to flow back into the inner cavity 8 through the return valve 5. This causes the piston plate 3, along with the piston rod 2, to move upwards until the top surface of the piston plate 3 contacts the bottom surface of the guide sleeve 7, at which point the return valve 5 closes. This invention enables delayed return repositioning of the piston rod 2 and piston plate 3 and allows control over the time of the delayed return repositioning. It effectively eliminates the impact on external products and components caused by the rapid return repositioning of the piston rod 2 when the compressed energy (rebound force) of the nitrogen spring is released instantaneously. This invention is particularly suitable for use in stamping dies (stamping forming dies).

[0023] In this embodiment, a sealing ring 11 and a guide ring 12 are embedded in the inner wall of the guide sleeve 7, and the plug rod 2 slides through the sealing ring 11 and the guide ring 12. The sealing ring 11 can seal the gap between the guide sleeve 7 and the plug rod 2, improve airtightness, and avoid air leakage; the guide ring 12 guides the plug rod 2, improving the stability of the plug rod 2's up and down movement.

[0024] In this embodiment, an air flow control valve 13 is provided inside the outer cavity 9, and the outer cavity 9 is connected to the return valve 5 via the air flow control valve 13. The air flow control valve 13 can control the amount of compressed nitrogen gas flowing back from the inner cavity 8 to the outer cavity 9, thereby controlling the upward return speed of the piston plate 3 and the piston rod 2, so as to achieve controllable return speed of the piston rod 2.

[0025] In this embodiment, an abutment block 14 is installed on the bottom wall of the inner cavity 8. The abutment block 14 is located inside the communicating hole and is used to abut the bottom surface of the piston plate 3. When the piston plate 3 moves down to the preset stroke, that is, when the piston plate 3 abuts the limiting step 10, the piston plate 3 also abuts the abutment block 14. The abutment block 14 limits the piston plate 3, ensuring the positional accuracy of the downward stroke of the piston rod 2, so as to play the role of overtravel protection.

[0026] In this embodiment, the contact block 14 has a vent hole 15, and the two ends of the vent hole 15 are respectively connected to the inflation valve 6 and the sliding hole. The vent hole 15 is provided to prevent the contact block 14 from blocking the air outlet of the inflation valve 6.

[0027] In this embodiment, the contact block 14 is a rubber pad. The rubber pad can provide cushioning and protection for the piston plate 3.

[0028] In this embodiment, the cylinder body 1 includes an inner cylinder 16, an outer cylinder 17 spaced outside the inner cylinder 16, a top cover 18 mounted on the top of the inner cylinder 16 and the top of the outer cylinder 17, and a bottom plate 19 mounted on the bottom of the inner cylinder 16 and the bottom of the outer cylinder 17. The inner hole of the inner cylinder 16 forms an inner cavity 8, and the outer side wall of the inner cylinder 16 and the inner side wall of the outer cylinder 17 form an outer cavity 9. The inflation valve 6 is embedded in the bottom plate 19. This structural design enables modular assembly of the cylinder body 1, facilitating disassembly, assembly, and maintenance.

[0029] In this embodiment, a dustproof ring 20 is provided between the top cover 18, the guide sleeve 7, and the plug rod 2, and the plug rod 2 slides through the dustproof ring 20. The dustproof ring 20 serves to seal and prevent dust.

[0030] In this embodiment, sealing rings 21 are provided between the inner cylinder 16 and the top cover 18, between the outer cylinder 17 and the top cover 18, between the inner cylinder 16 and the bottom plate 19, between the outer cylinder 17 and the bottom plate 19, and between the guide sleeve 7 and the inner cylinder 16. This structural design improves the airtightness of this nitrogen spring and avoids air leakage problems.

[0031] In this embodiment, a load valve is embedded in the base plate 19.

[0032] All technical features in this embodiment can be freely combined according to actual needs.

[0033] The above embodiments are preferred implementations of this utility model. In addition, this utility model can also be implemented in other ways. Any obvious substitutions without departing from the concept of this technical solution are within the protection scope of this utility model.

Claims

1. A time-lag return nitrogen gas spring characterized by: The cylinder includes a cylinder body (1), a piston rod (2), a piston plate (3), an overflow valve (4), a return valve (5), a charging valve (6), and a guide sleeve (7). The cylinder body (1) has an inner cavity (8) and an outer cavity (9) arranged sequentially from the inside to the outside. The inner cavity (8) has an insert hole, a sliding hole, and a connecting hole arranged sequentially from top to bottom. The overflow valve (4) and the return valve (5) are both embedded in the bottom of the cylinder body (1). The connecting hole of the inner cavity (8) is connected to the bottom end of the outer cavity (9) through the overflow valve (4). The overflow valve (4) is used to control the flow of nitrogen in the inner cavity (8) to the outer cavity (9). The bottom end of the outer cavity (9) is connected to the return valve (5) through the overflow valve (6). The flow valve (5) is connected to the connecting hole of the inner cavity (8). The return valve (5) is used to control the return of nitrogen in the outer cavity (9) to the inner cavity (8). The inflation valve (6) is embedded in the bottom of the cylinder (1) and connected to the inner cavity (8). The guide sleeve (7) is installed in the mounting hole. The piston rod (2) slides through the guide sleeve (7). The piston plate (3) is installed at the bottom end of the piston rod (2). The piston plate (3) is moved and set in the sliding hole. There is a gap between the peripheral side wall of the piston plate (3) and the inner side wall of the sliding hole. A limiting step (10) is formed between the sliding hole and the connecting hole. The limiting step (10) is used to abut the bottom surface of the piston plate (3).

2. The extended back travel nitrogen gas spring of claim 1, wherein: The inner wall of the guide sleeve (7) is fitted with a sealing ring (11) and a guide ring (12), and the plug rod (2) slides through the sealing ring (11) and the guide ring (12).

3. The extended back travel nitrogen gas spring of claim 1, wherein: An air flow control valve (13) is installed inside the outer cavity (9), and the outer cavity (9) is connected to the return valve (5) via the air flow control valve (13).

4. The extended back travel nitrogen gas spring of claim 1, wherein: The bottom wall of the inner cavity (8) is equipped with an abutment block (14), which is located in the connecting hole and is used to abut the bottom surface of the piston plate (3).

5. The extended back travel nitrogen gas spring of claim 4, wherein: The contact block (14) has a vent (15), and the two ends of the vent (15) are connected to the inflation valve (6) and the sliding hole, respectively.

6. The extended back travel nitrogen gas spring of claim 4, wherein: The contact block (14) is a rubber pad.

7. The extended back travel nitrogen gas spring of claim 1, wherein: The cylinder body (1) includes an inner cylinder (16), an outer cylinder (17) spaced outside the inner cylinder (16), a top cover (18) installed at the top of the inner cylinder (16) and the top of the outer cylinder (17), and a bottom plate (19) installed at the bottom of the inner cylinder (16) and the bottom of the outer cylinder (17). The inner hole of the inner cylinder (16) forms an inner cavity (8), and the outer side wall of the inner cylinder (16) and the inner side wall of the outer cylinder (17) form an outer cavity (9). The inflation valve (6) is embedded in the bottom plate (19).

8. The extended back travel nitrogen gas spring of claim 7, wherein: A dustproof ring (20) is provided between the top cover (18), the guide sleeve (7) and the plug rod (2), and the plug rod (2) slides through the dustproof ring (20).

9. The extended back travel nitrogen gas spring of claim 7, wherein: Sealing rings (21) are provided between the inner cylinder (16) and the top cover (18), between the outer cylinder (17) and the top cover (18), between the inner cylinder (16) and the bottom plate (19), between the outer cylinder (17) and the bottom plate (19), and between the guide sleeve (7) and the inner cylinder (16).

10. The extended back travel nitrogen gas spring of claim 7, wherein: The base plate (19) is fitted with a load valve.

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