A pilot valve and hydraulic drive barrel pump with pilot unloading

Abstract

A kind of pilot valve and hydraulic drive with pilot unloading bucket pump, including valve body, main output pipeline is opened in valve body, valve seat is arranged on valve body, inner hole is opened in valve seat, inner hole is communicated with main output pipeline, valve core is arranged in the inner hole of valve seat, valve core upper end is connected with pilot valve plunger rod, pilot valve plunger rod top is connected with hydraulic source inlet;And oil return port is opened in valve body, oil return port is communicated with the inner hole of valve seat.A kind of hydraulic drive with pilot unloading bucket pump, including oil tank and balance valve block, the balance valve block is provided with hydraulic motor balance valve block inlet, pressure reducing valve and throttle valve;Compared with prior art, the present application has the following beneficial effects: bucket pump with hydraulic drive, without power supply, unloading using pilot structure principle, safe and reliable.

Description

Technical Field

[0001] This invention relates to a pilot valve and a hydraulically driven bucket pump with pilot unloading. Background Technology

[0002] Grease is widely used as a lubricant and sealing material for mechanical components. Grease pumps typically insert directly into a grease container, drawing and pumping oil directly from the container. The pump frame or pumping device is usually matched with the grease container. However, grease has high viscosity and is semi-solid and semi-fluid in nature. The tail grease and HBW sealing grease used in tunnel boring machines contain a lot of fibers and have strong water-stopping properties. The amount used is very large. Therefore, grease is generally stored and transported in large-capacity grease containers to meet construction needs.

[0003] However, currently, generally speaking, tank pumps are not equipped with safety valve assemblies, or they are equipped with electrically powered safety valve assemblies, which have the following drawbacks: 1. Without a safety valve assembly, pressure surges can damage pipelines: When the tank pump suddenly stops or the outlet valve closes rapidly, the high-speed flowing liquid is instantly "stopped," generating a huge water hammer effect (pressure shock wave). This impact force far exceeds the normal operating pressure of the system, potentially causing pump body, outlet hose, valve, or joint rupture and leakage. Over time, this will also significantly reduce the lifespan of pipeline connections.

[0004] 2. The barrel pump is equipped with an electric safety valve assembly, which relies on power as the driving force. Due to the complex and variable lubrication environment, there are potential safety hazards.

[0005] 3. Risk of motor overload and burnout: The lack of unloading function means that the pump needs to withstand additional pressure load during startup or shutdown. For electric drum pumps, this will cause the motor current to rise sharply, which can easily lead to motor overload or even burnout over time. Although some electric pumps are equipped with "overload protectors," this is only end-point protection and cannot fundamentally solve the impact problem caused by frequent start-stop operations.

[0006] 4. Operational Safety and Maintenance Hazards: When it is necessary to quickly disconnect the pump pipe or replace the tank, if there is high-pressure liquid in the pipeline, direct disassembly may cause liquid splashing and injury. At the same time, pumps without unloading are subjected to impact loads on their couplings, bearings and other transmission components for a long time, which will accelerate wear and make them more prone to failures such as coupling wear leading to dry running or main shaft jamming, increasing maintenance frequency and downtime. Summary of the Invention

[0007] The technical problem to be solved by this invention is: how to design a hydraulically driven bucket pump with pilot unloading while ensuring safety.

[0008] To solve the above problems, the present invention is achieved through the following technical solution: A pilot valve includes a valve body with a main output pipeline, a valve seat on the valve body, an inner hole in the valve seat communicating with the main output pipeline, a valve core in the inner hole of the valve seat, a pilot valve plunger rod connected to the upper end of the valve core, and a hydraulic power source inlet connected to the top of the pilot valve plunger rod; and a return port on the valve body communicating with the inner hole of the valve seat.

[0009] The valve seat has an inner bore including a cylindrical bore at the bottom and an inverted conical bore at the top. The valve core is cylindrical in shape, with a conical shape at the bottom.

[0010] The pilot valve body includes an upper valve body and a lower valve body. The main output pipeline, valve seat and return port are all located on the lower valve body. The valve core is slidably arranged inside the valve seat. There is a grease gap between the valve seat and the valve core. The pilot valve plunger rod is slidably arranged in the inner hole of the upper valve body. There is a hydraulic oil gap between the pilot valve plunger rod and the upper valve body. A first Y-ring is provided between the pilot valve plunger rod and the upper valve body to seal the hydraulic oil gap; a second Y-ring is fitted over the valve core to seal the grease gap.

[0011] The top of the valve core is connected to the pilot plunger rod. An observation port is opened on the upper valve body, which connects to the grease gap, the hydraulic oil gap, and the outside.

[0012] A safety valve is installed on the main output pipeline.

[0013] A hydraulically driven bucket pump with pilot unloading includes an oil tank and a balance valve block, wherein the balance valve block is provided with a hydraulic motor balance valve block inlet, a pressure reducing valve and a throttle valve. The inlet of the hydraulic motor balance valve block is connected to the hydraulic power source through the balance valve block solenoid valve; the hydraulic power source is connected to the hydraulic motor through the pressure reducing valve and the throttle valve; the hydraulic motor is connected to the eccentric wheel drive; and the eccentric wheel is connected to the reciprocating tube assembly drive. The reciprocating tube assembly is located in the pump housing tube assembly. The bottom of the pump housing tube assembly is inserted into the oil tank, and a plunger rod is provided at the bottom of the pump housing tube assembly. Oil suction ports are opened on both sides of the bottom of the pump housing tube assembly. A connecting rod assembly is also provided in the pump housing tube assembly. The area between the pump housing tube assembly and the connecting rod assembly is the main oil passage. The reciprocating tube assembly reciprocates between the pump housing tube assembly and the connecting rod assembly. The top of the main oil passage is connected to the pump body outlet, which is connected to a pilot valve. The pilot valve has an outlet that is connected to the main output pipeline. When the system is unloaded, the system grease returns to the oil tank through the pilot valve.

[0014] A first annular step is provided on the inner wall of the reciprocating tube assembly, and a first one-way valve is provided above the first annular step. The diameter of the first one-way valve is larger than the inner diameter of the first annular step. A second one-way valve is fixedly provided at the end of the connecting rod assembly. The cavity between the first one-way valve and the second one-way valve is the oil storage tank, which is connected to the main oil passage.

[0015] Both the first check valve and the second check valve are ball valves, and the diameter of the first check valve is larger than the diameter of the second check valve.

[0016] The pump body is equipped with an oil outlet check valve.

[0017] A pressure gauge is installed on the balance valve block.

[0018] Compared with the prior art, the present invention has the following advantages: the barrel pump is hydraulically driven, requires no power supply, and utilizes the pilot structure principle for unloading, making it safe and reliable. Attached Figure Description

[0019] Figure 1 This is an overall structural diagram of the present invention; Figure 2 This is a diagram showing the connection structure of the eccentric wheel; Figure 3 This is a diagram showing the reciprocating tube assembly extending downwards. Figure 4 This is a diagram showing the state of the reciprocating tube assembly being pulled upwards. Figure 5 This is a structural diagram of a pilot valve. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] like Figure 1As shown, a hydraulically driven bucket pump with pilot unloading includes an oil tank 25, a tank cover 26 on the top of the oil tank 25, and a balance valve block 27 on the tank cover 26. The balance valve block 27 is provided with a hydraulic motor balance valve block inlet 2, a pressure reducing valve 3 and a throttle valve 6. The pressure reducing valve 3 can adjust the pressure required by the system, and the throttle valve 6 is used to adjust the flow rate of the power source.

[0023] The hydraulic motor balance valve block inlet 2 is connected to the hydraulic power source via the balance valve block solenoid valve 1. The hydraulic power source is connected to the hydraulic motor via the pressure reducing valve 3 and the throttle valve 6. The hydraulic motor is connected to the eccentric wheel 5, and the eccentric wheel 5 is connected to the reciprocating tube assembly 12. Specifically, the eccentric wheel 5 and the reciprocating tube assembly 12 can be connected by a reciprocating ring (sleeve), or the two can be connected by a connecting rod as an intermediate part. One end of the connecting rod is hinged to the eccentric pin on the eccentric wheel, and the other end is hinged to the reciprocating tube assembly 12. This is existing technology and will not be described in detail here.

[0024] like Figure 2 , Figure 3 , Figure 4 As shown, the reciprocating tube assembly 12 is located within the pump housing tube assembly 28. The bottom of the pump housing tube assembly 28 is inserted into the oil tank 25, and a plunger rod 14 is provided at the bottom of the pump housing tube assembly 28. Oil suction ports 29 are opened on both sides of the bottom of the pump housing tube assembly 28. A connecting rod assembly 30 is also provided within the pump housing tube assembly 28. The connecting rod assembly 30 is connected to the pump body pin 31 via threads, and the pump body pin 31 is fixedly connected to the pump body via a connector 32. It should be noted that the pump housing tube assembly 28 is fixed to the pump body, and the reciprocating tube assembly 12 is located within the pump housing tube assembly 28. The connecting rod assembly 30 is located within the reciprocating tube assembly 12. The pump housing tube assembly 28 and the connecting rod assembly 30 are fixed in place, and the area between the pump housing tube assembly 28 and the connecting rod assembly 30 is the main oil passage. The reciprocating tube assembly 12 reciprocates between the pump housing tube assembly 28 and the connecting rod assembly 30.

[0025] A first annular step 12-1 is provided on the inner wall of the reciprocating tube assembly 12. A first one-way valve 13-1 is provided above the first annular step 12-1. The diameter of the first one-way valve 13-1 is larger than the inner diameter of the first annular step 12-1, so that the reciprocating tube assembly 12 can drive the first one-way valve 13-1 to move upward together. Moreover, the density of the first one-way valve 13-1 is greater than the density of grease, so that the first one-way valve 13-1 is limited on the first annular step 12-1 in the absence of external force.

[0026] A second annular step 30-1 is provided on the inner wall of the end of the connecting rod assembly 30. A second one-way valve 13-2 is provided above the second annular step 30-1. The diameter of the second one-way valve 13-2 is larger than the inner diameter of the second annular step 30-1. The upper part of the second one-way valve 13-2 is mounted on the connecting rod assembly 30 by a fixing device, so that the second one-way valve 13-2 can only be fixedly positioned at the end of the connecting rod assembly 30.

[0027] Better yet, both the first check valve 13-1 and the second check valve 13-2 are ball valves, and the diameter of the first check valve 13-1 is larger than the diameter of the second check valve 13-2.

[0028] The cavity between the first one-way valve 13-1 and the second one-way valve 13-2 is the oil reservoir 33, which is connected to the main oil passage. Figure 3 , Figure 4 As shown, during operation, the reciprocating pipe assembly 12 moves up and down in conjunction with the plunger rod 14 to draw and pump oil. Grease enters from the suction port 29 at the bottom of the pump housing assembly 28. When the reciprocating pipe assembly 12 reaches its lowest point, the space in the oil reservoir 33 increases, pushing the grease stored in the suction port 29 up to the first one-way valve 13-1, allowing it to enter the oil reservoir 33 through the first one-way valve 13-1 and be stored there, thus forming an oil storage function. When the reciprocating pipe assembly 12 moves upward, it compresses the space in the oil reservoir 33, compressing the grease and creating pressure, which forces the grease in the oil reservoir 33 to the main oil passage, where it is then discharged.

[0029] The top of the main oil passage is connected to the pump body outlet 7, which is connected to a pilot valve 9. The pilot valve 9 has an outlet 10. Thus, grease passes through the pilot valve 9 and is discharged from the outlet 10. When the system is unloaded, the system grease returns to the oil tank 25 through the overflow pipe 11 of the pilot valve 9.

[0030] Even better, the pump body outlet 7 is equipped with an oil outlet check valve 8 to prevent high-pressure oil from returning to the oil tank 25.

[0031] In this way, the present invention draws oil from the bottom of the pump pipe and the oil tank, and the grease is delivered to the oil outlet 7 of the pump body through the two one-way valve assemblies 13 of the pump pipe assembly.

[0032] like Figure 5As shown, the pilot valve 9 includes a valve body with a main output pipeline 24 connected to the oil outlet 10. A valve seat 21 is mounted on the valve body, and an inner bore is formed within the valve seat 21, communicating with the main output pipeline 24. A valve core 19 is housed within the inner bore of the valve seat 21, allowing the valve core 19 to move within the valve seat 21. It should be noted that the inner bore of the valve seat 21 includes a cylindrical hole at the bottom and an inverted conical hole at the top. The valve core 19 is cylindrical in shape, with a conical section at the bottom. Thus, the bottom of the valve core 19 is inserted into the valve seat 21 from top to bottom. The upper end of the valve core 19 is connected to a pilot valve plunger rod 17, and the top of the pilot valve plunger rod 17 is connected to a hydraulic power source inlet 15. Furthermore, a return oil port 22 is provided on the valve body. The return oil port 22 is connected to the inner hole of the valve seat 21. The other end of the return oil port 22 is connected to the return oil pipe 34 through a pipeline. The return oil pipe 34 is inserted into the oil tank 25.

[0033] Better still, the pilot valve 9 comprises an upper valve body 91 and a lower valve body 92. The main output pipeline 24, valve seat 21, and return port 22 are all located on the lower valve body 92. A valve core 19 is slidably disposed within the valve seat 21, meaning there is a grease gap between the valve seat 21 and the valve core 19. The top of the valve core 19 is connected to a pilot plunger rod 17, which is slidably disposed within the inner hole of the upper valve body 91, meaning there is a hydraulic oil gap between the pilot plunger rod 17 and the upper valve body 91. An observation port 18 is provided on the upper valve body 91, connecting the grease gap, the hydraulic oil gap, and the outside. When connected to the outside, it can be led out through a pipeline.

[0034] To ensure sealing performance, in this invention, a first Y-ring 16 is provided between the pilot valve plunger rod 17 and the upper valve body 91, and the first Y-ring 16 seals the hydraulic oil gap; a second Y-ring 20 is fitted over the valve core 19, and the second Y-ring 20 seals the grease gap.

[0035] When the pilot valve 9 is working normally, the top of the main oil passage is connected to the pump body outlet 7, and the pump body outlet 7 is connected to the pilot valve 9. After the lubricating grease passes through the main output pipeline 24, it is discharged through the outlet 10. Under this condition, hydraulic oil continuously enters the hydraulic source inlet 15, causing the pilot valve plunger rod 17 to press down the valve core 19, and the valve core 19 is inserted into the valve seat 21.

[0036] When the system is unloaded, i.e. the hydraulic power source is disconnected and the pressure at the hydraulic power source inlet 15 returns to zero, the main output pipeline 24 still has pressure. At this time, the pressure pushes the valve core 19 open from bottom to top. The valve core 19 moves upward against the pilot valve plunger rod 17 and the first Y-ring 16. At this time, the grease in the main output pipeline 24 communicates with the return port 22 through the gap between the valve core 19 and the valve seat 21, completing the unloading action of the system pressure. In this way, the grease passes through the return port 22 of the pilot valve 9. The return port 22 is connected to the overflow pipe 11. The overflow pipe 11 returns to the oil tank 25 through the return pipe 34.

[0037] The first Y-ring 16 and the second Y-ring 20 serve a sealing function. If the first Y-ring 16 and the second Y-ring 20 are damaged, they can be checked by overflow from the observation port 18: when the overflow is hydraulic oil, it can be determined that the first Y-ring 16 is damaged; when the overflow from the observation port 18 is grease, it can be determined that the second Y-ring 20 is damaged. The damaged part can be accurately determined, and the fault can be troubleshooted in a timely and efficient manner.

[0038] Even better, a safety valve 23 is installed on the main output line 24 to achieve automatic overpressure relief and protect the system.

[0039] Even better, a pressure gauge 4 is provided on the balance valve block 27.

[0040] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several changes and improvements without departing from the overall concept of the present invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A pilot valve (9), characterized in that: The valve body includes a main output pipeline (24) and a valve seat (21). The valve seat (21) has an inner hole that is connected to the main output pipeline (24). A valve core (19) is installed in the inner hole of the valve seat (21). The upper end of the valve core (19) is connected to the pilot valve plunger rod (17), and the top of the pilot valve plunger rod (17) is connected to the hydraulic power source inlet (15). The valve body also has a return port (22) that is connected to the inner hole of the valve seat (21).

2. The pilot valve according to claim 1, characterized in that: The inner hole of the valve seat (21) includes a cylindrical hole at the bottom and an inverted conical hole at the top. The valve core (19) is cylindrical in shape, with a conical shape at the bottom of the cylindrical shape.

3. The pilot valve according to claim 1, characterized in that: The valve body of the pilot valve (9) includes an upper valve body (91) and a lower valve body (92). The main output pipeline (24), valve seat (21) and return port (22) are all located on the lower valve body (92). The valve core (19) is slidably arranged inside the valve seat (21). There is a grease gap between the valve seat (21) and the valve core (19). The pilot valve plunger rod (17) is slidably arranged in the inner hole of the upper valve body (91). There is a hydraulic oil gap between the pilot valve plunger rod (17) and the upper valve body (91). A first Y-ring (16) is provided between the pilot valve plunger rod (17) and the upper valve body (91), and the first Y-ring (16) seals the hydraulic oil gap; a second Y-ring (20) is sleeved on the valve core (19), and the second Y-ring (20) seals the grease gap.

4. The pilot valve according to claim 3, characterized in that: The top of the valve core (19) is connected to the pilot plunger rod (17). An observation port (18) is opened on the upper valve body (91). The observation port (18) connects the grease gap, the hydraulic oil gap and the outside.

5. The pilot valve according to claim 1, characterized in that: A safety valve (23) is installed on the main output line (24).

6. A hydraulically driven bucket pump with pilot unloading, characterized in that: It includes an oil tank (25) and a balance valve block (27), wherein the balance valve block (27) is provided with a hydraulic motor balance valve block inlet (2), a pressure reducing valve (3) and a throttle valve (6); The inlet (2) of the hydraulic motor balance valve block is connected to the hydraulic source through the balance valve block solenoid valve (1); the hydraulic source is connected to the hydraulic motor through the pressure reducing valve (3) and the throttle valve (6); the hydraulic motor is connected to the eccentric wheel (5) for transmission; and the eccentric wheel (5) is connected to the reciprocating tube assembly (12) for transmission. The reciprocating pipe assembly (12) is located in the pump housing pipe assembly (28). The bottom of the pump housing pipe assembly (28) is inserted into the oil tank (25), and a plunger rod (14) is provided at the bottom of the pump housing pipe assembly (28). Oil suction ports (29) are opened on both sides of the bottom of the pump housing pipe assembly (28). A connecting rod assembly (30) is also provided in the pump housing pipe assembly (28). The area between the pump housing pipe assembly (28) and the connecting rod assembly (30) is the main oil passage. The reciprocating pipe assembly (12) reciprocates between the pump housing pipe assembly (28) and the connecting rod assembly (30). The top of the main oil passage is connected to the pump body outlet (7), the pump body outlet (7) is connected to the pilot valve (9), the pilot valve (9) is provided with an outlet (10), the pilot valve (9) is any of the pilot valves described in claims 1-4, the outlet (10) is connected to the main output pipeline (24); when the system is unloaded, the system grease returns to the oil tank (25) through the pilot valve (9).

7. A hydraulically driven bucket pump with pilot unloading according to claim 6, characterized in that: A first annular step (12-1) is provided on the inner wall of the reciprocating tube assembly (12), and a first one-way valve (13-1) is provided above the first annular step (12-1). The diameter of the first one-way valve (13-1) is larger than the inner diameter of the first annular step (12-1). A second one-way valve (13-2) is fixedly provided at the end of the connecting rod assembly (30). The cavity between the first one-way valve (13-1) and the second one-way valve (13-2) is the oil storage tank (33), and the oil storage tank (33) is connected to the main oil passage.

8. A hydraulically driven bucket pump with pilot unloading according to claim 7, characterized in that: Both the first check valve (13-1) and the second check valve (13-2) are ball valves, and the diameter of the first check valve (13-1) is larger than the diameter of the second check valve (13-2).

9. A hydraulically driven bucket pump with pilot unloading according to claim 6, characterized in that: The pump body oil outlet (7) is equipped with an oil outlet check valve (8).

10. A hydraulically driven bucket pump with pilot unloading according to claim 6, characterized in that: A pressure gauge (4) is installed on the balance valve block (27).

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