Pressure-adjustable grease filling automatic cut-off system and pressure-adjusting method thereof

Abstract

The application discloses a pressure-adjustable grease filling automatic cut-off system and a pressure regulating method thereof, and the system comprises an automatic cut-off valve, an overflow valve, a ball valve and a pressure gauge, the automatic cut-off valve is axially provided with a main joint, a lower cylinder body and a cylinder body end cover, coaxially provided with a piston rod and a piston in the inside, and is provided with a lower compression spring, a plurality of sealing rings, a breathing plug and a pressure regulating knob, the piston rod is provided with a fluid passage and a stroke limiting structure; the pressure is regulated by obtaining the parameters of the cylinder body, the piston rod and the compression spring, substituting into a formula to calculate the corresponding relationship between the pressure and the knob displacement, and adjusting the knob to complete the pressure setting. The application realizes the double functions of pressure adjustment and automatic cut-off, the pressure in the grease barrel can be accurately set according to the grease supplementing demand through the pressure regulating knob, when the pressure in the barrel reaches the set value, the piston moves to the limiting position and cuts off the fluid passage, and the grease supplementing is automatically closed, so that the grease barrel is fully supplemented with grease, and the barrel body is prevented from being broken due to excessive pressure.

Description

Technical Field

[0001] This invention relates to the field of grease lubrication filling equipment technology, specifically to an adjustable pressure grease filling automatic shut-off system and its pressure adjustment method. Background Technology

[0002] With the widespread adoption of automated equipment in industrial and mining enterprises, critical points on mechanical equipment require regular lubrication. Some enterprises have scattered lubrication points, necessitating the use of lubrication trucks to replenish grease tanks at each point. Since the grease tanks lack external level gauges, it's impossible to visually determine if they are full. Overfilling during lubrication can easily lead to a sudden increase in pressure, potentially causing the tank to rupture. Existing lubrication equipment lacks a suitable integrated system with adjustable pressure and automatic shut-off, making it difficult to balance adequate lubrication with pressure safety. Therefore, there is an urgent need for a device that can adjust the pressure inside the grease tank and automatically shut off lubrication when the pressure reaches the target level. Summary of the Invention

[0003] The purpose of this invention is to overcome or at least partially solve the above problems by proposing an automatic shut-off system for adjustable grease filling and its pressure regulation method.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: an adjustable pressure grease filling automatic shut-off system, including an automatic shut-off valve, an overflow valve, a ball valve and a pressure gauge; the automatic shut-off valve is provided with a main connector, a lower cylinder and a cylinder end cover in sequence along the axial direction, and the main connector and the lower cylinder, as well as the lower cylinder and the cylinder end cover, are detachably sealed connections.

[0005] The automatic shut-off valve has a piston rod coaxially arranged inside. The upper end of the piston rod is sealed to the main connector, and the lower end extends to the bottom of the lower cylinder cavity and is slidably fitted with a piston. The piston is slidably sealed to the inner wall of the lower cylinder.

[0006] An upper compression spring is sleeved on the outer wall of the piston rod between the main connector and the piston, and a lower compression spring is provided between the cylinder end cover and the piston rod;

[0007] The main connector is equipped with a breather plug and a pressure adjustment knob at its top. The breather plug is used to balance the pressure inside the valve cavity with the external pressure. The pressure adjustment knob sets the pressure inside the grease tank by limiting the axial displacement of the piston rod and adjusting the compression of the upper pressure spring.

[0008] Preferably, the main connector and the lower cylinder are connected by a threaded connection, and a second sealing ring is provided between them to achieve radial static sealing; the main connector and the piston rod are connected by a threaded connection, and a first sealing ring is provided between them to achieve radial static sealing.

[0009] Preferably, a piston end cap is screwed to the bottom of the piston, and a sixth sealing ring is provided between the two to achieve radial static sealing. The inner wall of the piston slides with the outer wall of the piston rod and achieves radial dynamic sealing through a third sealing ring. The outer wall of the piston slides with the inner wall of the lower cylinder and achieves radial dynamic sealing through a fifth sealing ring.

[0010] Preferably, a fourth sealing ring is fixedly sleeved on the lower part of the outer wall of the piston rod. The fourth sealing ring is located above the piston cavity and is used to limit the upper stroke limit of the piston and seal the fluid passage between the piston cavity and the piston rod. A retaining spring is provided on the lower part of the outer wall of the piston rod. The retaining spring is located at the bottom of the piston end cap and is used to limit the lower stroke limit of the piston.

[0011] Preferably, the breathing plug is press-fitted into the top vent hole of the main connector in an interference fit manner, so that the internal cavity of the automatic shut-off valve is connected to the outside atmosphere.

[0012] Preferably, the piston rod has an axially extending fluid passage inside. When the piston moves to the limit position defined by the fourth sealing ring or snap ring, the piston cuts off the fluid passage, thereby achieving automatic shut-off of grease filling.

[0013] Preferably, the lower compression spring is coaxially sleeved inside the lower end of the piston rod, with one end abutting against the inner end face of the cylinder end cover and the other end abutting against the piston rod, for providing axial limiting force to the piston and piston rod.

[0014] Preferably, the fluid passage of the piston rod starts from a bottom hole with a top diameter of 11 mm, transitions through 6 radially distributed through holes with a diameter of 6 mm to 5 radially distributed through holes with a diameter of 6 mm, and finally ends with a bottom hole with a diameter of 11 mm.

[0015] A pressure adjustment method for an adjustable grease filling and automatic shut-off system involves adjusting a pressure adjustment knob to change the axial displacement of the piston rod, thereby altering the compression of the upper pressure spring and adjusting the set pressure inside the grease tank. The specific steps are as follows:

[0016] S1. Obtain the inner diameter R1 of the lower cylinder, the outer diameter R2 of the piston rod, the free length L0 of the upper compression spring, and the compressed length L of the upper compression spring. x ;

[0017] S2. Calculate the relationship between the target pressure P and the displacement Wx of the pressure adjustment knob, where α ranges from 0.985 to 1.055. The formula for calculating the pressure inside the grease tank is:

[0018] P=-k*(L0-L x +W x )*α / π*(R1^2-R2^2);

[0019] S3, based on the displacement W corresponding to the target pressure P. x Adjust the pressure adjustment knob to lock the axial position of the piston rod.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. It achieves dual functions of adjustable pressure and automatic shut-off. The pressure adjustment knob can be used to accurately set the pressure inside the oil tank according to the oil replenishment needs. When the pressure inside the tank reaches the set value, the piston moves to the limit position and cuts off the fluid passage, automatically shutting off the oil replenishment. This ensures that the oil tank is fully replenished while avoiding the tank body from breaking due to excessive pressure.

[0022] 2. The system has a reasonable sealing and limiting structure design. Each connection part achieves static or dynamic sealing through sealing rings. A fourth sealing ring and a snap ring are set on the piston rod to limit the upper and lower strokes of the piston. The sealing performance is good and the limiting is accurate, effectively preventing grease leakage and excessive wear of parts.

[0023] 3. The breather plug balances the internal pressure of the automatic shut-off valve with the external pressure, ensuring the stability of the upper pressure spring. At the same time, all components of the system are detachable, making maintenance and replacement of parts convenient and greatly extending the service life of the automatic shut-off valve.

[0024] 4. The pressure regulation method has clear steps and accurate calculations. It introduces a field working condition correction coefficient α, which can be adapted to the usage needs of different mining sites. The pressure regulation has high adaptability and accuracy. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the external working principle of the present invention;

[0026] Figure 2 This is a hydraulic schematic diagram of the present invention;

[0027] Figure 3 This is a schematic diagram of the internal working principle of the automatic shut-off valve of the present invention;

[0028] Figure 4 This is a diagram showing the internal structure of the automatic shut-off valve of the present invention.

[0029] Figure 5 This is a structural diagram of the main connector of the automatic shut-off valve of the present invention;

[0030] Figure 6 This is a structural diagram of the lower cylinder of the automatic shut-off valve of the present invention;

[0031] Figure 7 This is a structural diagram of the piston rod of the automatic shut-off valve of the present invention;

[0032] Figure 8 This is a structural diagram of the automatic shut-off valve piston of the present invention.

[0033] In the diagram: 1. Breathing plug; 2. Main connector; 3. First sealing ring; 4. Second sealing ring; 5. Piston rod; 6. Lower cylinder; 7. Compression spring; 8. Third sealing ring; 9. Fourth sealing ring; 10. Piston; 11. Fifth sealing ring; 12. Sixth sealing ring; 13. Piston end cap; 14. Snap ring; 15. Pressure adjustment knob; 16. Spring; 17. Cylinder end cap. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings.

[0035] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this description, those skilled in the art can make creative modifications to this embodiment as needed, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

[0036] This invention provides an adjustable pressure grease filling automatic shut-off system and its pressure regulating method, which solves the technical problems in the prior art. The overall concept is as follows:

[0037] Example 1

[0038] Please see Figures 1-8 An adjustable pressure grease filling automatic shut-off system includes an automatic shut-off valve, an overflow valve, a ball valve, and a pressure gauge; the automatic shut-off valve is provided with a main connector 2, a lower cylinder 6, and a cylinder end cover 17 arranged sequentially along the axial direction, and the main connector 2 and the lower cylinder 6, and the lower cylinder 6 and the cylinder end cover 17 are all threaded connections.

[0039] The automatic shut-off valve has a piston rod 5 coaxially arranged inside. The upper end of the piston rod 5 is sealed to the main connector 2, and the lower end extends to the bottom of the inner cavity of the lower cylinder 6 and is slidably fitted with a piston 10. The piston 10 is slidably sealed to the inner wall of the lower cylinder 6.

[0040] An upper compression spring 7 is sleeved on the outer wall of the piston rod 5 between the main connector 2 and the piston 10, and a lower compression spring 16 is provided between the cylinder end cover 17 and the piston rod 5.

[0041] The main connector 2 is equipped with a breather plug 1 and a pressure adjustment knob 15 at the top. The breather plug 1 is used to balance the pressure inside the valve cavity with the external pressure. The pressure adjustment knob 15 sets the pressure inside the grease tank by limiting the axial displacement of the piston rod 5 and adjusting the compression of the upper pressure spring 7.

[0042] In specific implementation, the main connector 2 and the lower cylinder 6 are connected by threaded engagement, and a second sealing ring 4 is provided between them to achieve radial static sealing; the main connector 2 and the piston rod 5 are connected by threaded engagement, and a first sealing ring 3 is provided between them to achieve radial static sealing.

[0043] In specific implementation, a piston end cap 13 is screwed to the bottom of the piston 10, and a sixth sealing ring 12 is provided between the two to achieve radial static sealing. The inner wall of the piston 10 slides with the outer wall of the piston rod 5 and achieves radial dynamic sealing through the third sealing ring 8. The outer wall of the piston 10 slides with the inner wall of the lower cylinder 6 and achieves radial dynamic sealing through the fifth sealing ring 11.

[0044] In specific implementation, a fourth sealing ring 9 is fixedly sleeved on the lower part of the outer wall of the piston rod 5. The fourth sealing ring 9 is located above the cavity of the piston 10 and is used to limit the upper stroke limit of the piston 10 and seal the fluid passage between the cavity of the piston 10 and the piston rod 5. A retaining ring 14 is provided on the lower part of the outer wall of the piston rod 5. The retaining ring 14 is located at the bottom of the piston end cap 13 and is used to limit the lower stroke limit of the piston 10.

[0045] In practice, the breathing plug 1 is press-fitted into the top vent hole of the main connector 2 with an interference fit, so that the internal cavity of the automatic shut-off valve is connected to the outside atmosphere.

[0046] In practice, the piston rod 5 has an axially extending fluid passage inside. When the piston 10 moves to the limit position defined by the fourth sealing ring 9 or the snap ring 14, the piston 10 cuts off the fluid passage, thereby achieving automatic shut-off of grease filling.

[0047] In practice, the lower compression spring 16 is coaxially sleeved inside the lower end of the piston rod 5, with one end abutting against the inner end face of the cylinder end cover 17 and the other end abutting against the piston rod 5, to provide axial limiting force for the piston 10 and the piston rod 5.

[0048] In specific implementation, such as Figure 7 As shown, the piston rod 6 is made of free-cutting steel 1215 with an outer wall roughness of Ra0.6. The thread connecting it to the main connector 3 is M25x1.0. The fluid passage of the piston rod 5 starts from the bottom hole with a diameter of 11mm at the top, transitions through 6 radially distributed through holes with a diameter of 6mm to 5 radially distributed through holes with a diameter of 6mm, and finally ends at the bottom hole with a diameter of 11mm.

[0049] In specific implementation, such as Figure 5 As shown, the main connector 2 is made of 45# steel, the grease inlet connection thread is the standard 11 / 16-12 UN, the external connection thread to the grease tank is BSPT 2", and the connection thread to the lower cylinder 6 is M52x1.5.

[0050] Specifically, in implementation, such as Figure 6 As shown, the lower cylinder 6 uses a standard honed tube with an inner wall roughness of Ra0.6, and the thread connecting it to the main connector 2 is M52x1.5.

[0051] In specific implementation, such as Figure 8 As shown, piston 10 is made of aluminum alloy 6061.

[0052] Its detailed connection methods are well-known technologies in this field. The following mainly introduces the working principle and process, and the specific work is as follows:

[0053] The automatic shut-off valve is installed at the bottom of the grease tank lid and is sealed to the grease tank through the BSPT2” tapered thread of the main connector 2. The grease inlet of the automatic shut-off valve is connected in sequence to the ball valve, pressure gauge and overflow valve, and finally connected to the metering pump of the grease replenishment vehicle. This system is suitable for the filling operation of No. 2 grease.

[0054] Working principle of grease replenishment: When the ball valve is opened, the metering pump of the grease replenishment cart pumps No. 2 grease into the grease tank through the fluid passage at a maximum output pressure of 3500psi. The pressure in the grease tank gradually increases as grease is injected. The pressure in the grease tank pushes the piston 10 to move axially upward along the piston rod 5, and the upper pressure spring 7 is further compressed as the piston 10 moves. When the pressure in the grease tank approaches the set pressure (9psi~10psi), the piston 10 moves to the limit position of the fourth sealing ring 9. At this time, the elastic force of the upper pressure spring 7 is balanced with the pressure in the grease tank. The piston 10 and the fourth sealing ring 9 are in contact and sealed, cutting off the fluid passage in the piston rod 5. The automatic shut-off valve completes the automatic shut-off, and the grease replenishment action stops. At this time, the ball valve is manually closed to complete a single grease replenishment.

[0055] Abnormal pressure relief principle: When a system malfunction causes the pressure inside the grease tank to rise abnormally and exceed 25 psi, the overflow valve will automatically open to release excess grease from the tank until the pressure drops to a safe range. Then the overflow valve will close, thus achieving pressure safety protection for the grease tank.

[0056] Pressure balance principle: The breather plug 1 at the top of the main connector 2 provides a communication channel between the internal cavity of the automatic shut-off valve and the outside atmosphere, ensuring that the pressure inside the cavity and the external pressure are always balanced during the compression and reset process of the upper pressure spring 7, and avoiding the generation of negative or positive pressure inside the cavity, which would affect the working stability of the upper pressure spring 7 and the movement flexibility of the piston 10.

[0057] The specific implementation steps of the voltage regulation method of the present invention are as follows:

[0058] S1. Obtain the inner diameter R1 (mm) of the lower cylinder 6, the outer diameter R2 (mm) of the piston rod 5, the free length L0 (mm) of the upper compression spring 7, and the compressed length L of the upper compression spring 7. x The specific value (unit: mm);

[0059] S2. Calculate the correspondence between the target pressure P (in psi) and the displacement Wx (in mm) of the pressure adjustment knob 15, where α ranges from 0.985 to 1.055. The formula for calculating the pressure inside the grease container is:

[0060] P=-k*(L0-Lx +W x )*α / π*(R1^2-R2^2);

[0061] S3, based on the displacement W corresponding to the target pressure P. x Adjust the pressure adjustment knob 15 to lock the axial position of the piston rod 5.

[0062] The pressure-adjustable grease filling automatic shut-off system and its pressure adjustment method of the present invention have a compact structure, precise sealing and limiting, and convenient pressure adjustment. It can effectively solve the problems of uncontrollable pressure and easy tank rupture during grease replenishment in industrial and mining enterprises. In addition, the system is easy to maintain, has a long service life, and is suitable for various industrial and mining conditions where grease replenishment points are scattered. It has high practical value and promotion value.

[0063] The above description of the embodiments is provided to facilitate understanding and use of the present invention by those skilled in the art. It is obvious to those skilled in the art that various modifications can be made to the embodiments, and the general principles described herein can be applied to other embodiments without creative effort. Therefore, the present invention is not limited to the above embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. An automatic shut-off system for pressure-adjustable grease filling, characterized in that: It includes an automatic shut-off valve, an overflow valve, a ball valve and a pressure gauge; the automatic shut-off valve is provided with a main connector (2), a lower cylinder (6) and a cylinder end cover (17) in sequence along the axial direction, and the main connector (2) and the lower cylinder (6) and the lower cylinder (6) and the cylinder end cover (17) are detachable and sealed connections. The automatic shut-off valve has a piston rod (5) coaxially arranged inside. The upper end of the piston rod (5) is sealed to the main connector (2), and the lower end extends to the bottom of the inner cavity of the lower cylinder (6) and is slidably fitted with a piston (10). The piston (10) is slidably sealed to the inner wall of the lower cylinder (6). An upper compression spring (7) is sleeved on the outer wall of the piston rod (5) and between the main connector (2) and the piston (10), and a lower compression spring (16) is provided between the cylinder end cover (17) and the piston rod (5). The main connector (2) is provided with a breather plug (1) and a pressure adjustment knob (15) at the top. The breather plug (1) is used to balance the pressure inside the valve cavity with the external pressure. The pressure adjustment knob (15) sets the pressure inside the grease tank by limiting the axial displacement of the piston rod (5) and adjusting the compression of the upper pressure spring (7).

2. The pressure-adjustable grease filling automatic shut-off system according to claim 1, characterized in that: The main connector (2) and the lower cylinder (6) are connected by a threaded connection, and a second sealing ring (4) is provided between them to achieve radial static sealing; the main connector (2) and the piston rod (5) are connected by a threaded connection, and a first sealing ring (3) is provided between them to achieve radial static sealing.

3. The pressure-adjustable grease filling automatic shut-off system according to claim 1, characterized in that: The piston (10) is also screwed to the bottom of the piston end cap (13), and a sixth sealing ring (12) is provided between the two to achieve radial static sealing. The inner wall of the piston (10) slides with the outer wall of the piston rod (5) and achieves radial dynamic sealing through the third sealing ring (8). The outer wall of the piston (10) slides with the inner wall of the lower cylinder (6) and achieves radial dynamic sealing through the fifth sealing ring (11).

4. The pressure-adjustable grease filling automatic shut-off system according to claim 1, characterized in that: A fourth sealing ring (9) is fixedly sleeved on the lower part of the outer wall of the piston rod (5). The fourth sealing ring (9) is located above the piston (10) cavity and is used to limit the upper stroke limit of the piston (10) and seal the fluid passage between the piston (10) cavity and the piston rod (5). A retaining ring (14) is provided on the lower part of the outer wall of the piston rod (5). The retaining ring (14) is located at the bottom of the piston end cap (13) and is used to limit the lower stroke limit of the piston (10).

5. The pressure-adjustable grease filling automatic shut-off system according to claim 1, characterized in that: The breathing plug (1) is press-fitted into the top vent hole of the main connector (2) in an interference fit manner, so that the internal cavity of the automatic shut-off valve is connected to the outside atmosphere.

6. The pressure-adjustable grease filling automatic shut-off system according to claim 1, characterized in that: The piston rod (5) has an axially extending fluid passage inside. When the piston (10) moves to the limit position defined by the fourth sealing ring (9) or the snap ring (14), the piston (10) cuts off the fluid passage, thereby achieving automatic shut-off of grease filling.

7. The pressure-adjustable grease filling automatic shut-off system according to claim 1, characterized in that: The lower compression spring (16) is coaxially sleeved inside the lower end of the piston rod (5), with one end abutting against the inner end face of the cylinder end cover (17) and the other end abutting against the piston rod (5), and is used to provide axial limiting force for the piston (10) and the piston rod (5).

8. The pressure-adjustable grease filling automatic shut-off system according to claim 1, characterized in that: The fluid passage of the piston rod (5) starts from the bottom hole with a diameter of 11 mm at the top, transitions through 6 radially distributed through holes with a diameter of 6 mm to 5 radially distributed through holes with a diameter of 6 mm, and finally ends with the bottom hole with a diameter of 11 mm at the bottom.

9. A pressure regulating method for an adjustable grease filling automatic shut-off system, applied to the grease filling automatic shut-off system according to any one of claims 1-8, characterized in that: The axial displacement of the piston rod (5) is changed by adjusting the pressure adjustment knob (15), thereby changing the compression of the upper pressure spring (7) to adjust the set pressure inside the grease tank. The specific steps are as follows: S1. Obtain the inner diameter R1 of the lower cylinder (6), the outer diameter R2 of the piston rod (5), the free length L0 of the upper compression spring (7), and the compressed length L of the upper compression spring (7). x ; S2. Calculate the relationship between the target pressure P and the displacement Wx of the pressure adjustment knob (15), where the value of α ranges from 0.985 to 1.

055. The formula for calculating the pressure inside the grease tank is: P=-k*(L0-L x +W x )*α / π*(R1^2-R2^2); S3, based on the displacement W corresponding to the target pressure P. x Adjust the pressure adjustment knob (15) to lock the axial position of the piston rod (5).

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