Overflow valve for hydraulic driving system of loading machine

Abstract

The utility model discloses an overflow valve for a hydraulic driving system of a loader, which relates to the technical field of loaders and particularly comprises a piston body and a valve body, the valve body is fixed at the bottom of the piston body, a screw rod is movably connected to the top of an inner cavity of the piston body, and the bottom end of the screw rod is in threaded connection with a threaded block. A spring is fixedly connected to the bottom of the threaded block, a valve element is fixedly connected to the bottom of the spring, and the bottom end of the valve element extends into the inner cavity of the valve body. According to the overflow valve for the hydraulic driving system of the loading machine, through the arrangement of a first pressure sensor and a second pressure sensor, the first pressure sensor can detect the pressure value of a guide pressing plate on the bottom of an inner cavity of a piston body, and the second pressure sensor can detect the pressure of hydraulic oil on a valve element; a user can judge whether the spring is in an elastic fatigue state or not according to the numerical value detected by the first pressure sensor and the numerical value detected by the second pressure sensor, the user can master the state of the spring, and the spring can be replaced in time conveniently.

Description

Technical Field

[0001] The utility model relates to the technical field of loaders, in particular to a relief valve for a hydraulic drive system of a loader. Background Art

[0002] Loaders are earthmoving machines widely used in construction projects such as highways, railways, buildings, hydropower stations, ports, and mines. Their primary operating conditions are excavation and loading. Due to operational requirements, the working device must perform bucket collection, lifting, unloading, and lowering, requiring frequent left and right steering. These movements are typically controlled and achieved through the loader's hydraulic system. The relief valve is a common pressure control element in loader hydraulic systems. By regulating the system's operating pressure or limiting its maximum operating pressure through overflow, it prevents system overload and ensures the safety of the hydraulic system.

[0003] The working principle of the relief valve in the prior art is generally as follows: when the internal pressure of the hydraulic drive system increases to a set value, the valve core of the relief valve will be lifted up by the hydraulic oil, and the excess hydraulic oil will flow into the hydraulic oil tank through the outlet of the relief valve. However, the valve core will produce friction with the inner wall of the relief valve during movement. After long-term use, leakage problems are prone to occur, and the valve core is generally reset by a spring. After a certain period of use, the spring will experience elastic fatigue problems. However, the relief valve in the prior art is usually unable to understand the status of the spring, so that the spring cannot be replaced in time, thereby affecting the use effect of the relief valve. Based on this, the present application proposes a relief valve for a loader hydraulic drive system. Utility Model Content

[0004] The utility model provides a relief valve for a hydraulic drive system of a loader, which solves the problem in the above background technology that the valve core of the relief valve is easily leaked due to wear; and the problem that the state of the spring cannot be reflected in time, making it inconvenient to replace the relief valve in time.

[0005] The utility model provides the following technical solution: a relief valve for a hydraulic drive system of a loader, comprising a piston body and a valve body, wherein the valve body is fixed to the bottom of the piston body, the top of the inner cavity of the piston body is movably connected to a screw rod, the bottom end of the screw rod is threadedly connected to a threaded block, the bottom of the threaded block is fixedly connected to a spring, the bottom of the spring is fixedly connected to a valve core, the bottom end of the valve core extends into the inner cavity of the valve body, a second pressure sensor is fixed to the middle part of the bottom of the valve core, a guide pressure plate is fixed to the outer ring of the top end of the valve core, a guide rod, a first pressure sensor and an inflation ring are fixed to the bottom of the inner cavity of the piston body, the guide pressure plate and the threaded block are movably connected to the guide rod, and the first pressure sensor and the inflation ring are both located directly below the guide pressure plate;

[0006] A liquid inlet is provided at the bottom of the inner cavity of the valve body, an impurity filter is provided at one end of the liquid inlet, a liquid outlet is provided on one side of the inner cavity of the valve body, a sealing sleeve is fixed at the top end of the inner cavity of the valve body, the valve core is fixedly connected to the bottom end of the sealing sleeve, and the inner cavity of the sealing sleeve is connected to the inner cavity of the inflation ring through an airway.

[0007] Preferably, the bottom end of the sealing sleeve is movably connected to the inner cavity of the valve body, and the bottom of the sealing sleeve is located below the liquid outlet.

[0008] Preferably, the inner diameter of the liquid inlet is larger than the inner diameter of the valve body; and a rotating handle is fixedly connected to the top of the screw rod.

[0009] Preferably, the valve core is located in the inner cavity of the sealing sleeve, and the inner diameter of the valve core is adapted to the inner diameter of the valve body.

[0010] Preferably, the bottom end of the piston body is evenly provided with air channels, and the bottom of the inflation ring and the top of the sealing sleeve are both provided with ventilation holes adapted to the air channels.

[0011] Preferably, when the guide pressure plate is tightly fitted to the bottom of the inner cavity of the piston body, the bottom of the valve core is located below the liquid outlet.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. The overflow valve of the loader hydraulic drive system is equipped with an impurity filter, which can filter the hydraulic oil entering the overflow valve to prevent impurities in the hydraulic oil from clogging the overflow valve, making it easier to use the overflow valve. The sealing sleeve and the inflatable ring are arranged so that when the valve core stops moving, the sealing sleeve undergoes elastic deformation to seal the gap between it and the valve body, thereby ensuring the air tightness of the overflow valve.

[0014] 2. The loader's hydraulic drive system uses an overflow valve. Through the setting of pressure sensor 1 and pressure sensor 2, pressure sensor 1 can detect the pressure value of the guide pressure plate on the bottom of the inner cavity of the piston body, and pressure sensor 2 can detect the pressure of the hydraulic oil on the valve core. The user can determine whether the spring is in a state of elastic fatigue based on the values ​​detected by pressure sensor 1 and pressure sensor 2. The user can understand the status of the spring and facilitate timely replacement of the spring. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a front view of the structure of the utility model;

[0016] Figure 2 For the utility model structure Figure 1 Bottom schematic diagram;

[0017] Figure 3 For the utility model structure Figure 1 Internal schematic diagram;

[0018] Figure 4 For the utility model structure Figure 3 Front view schematic diagram;

[0019] Figure 5 This is a schematic diagram of the bottom of the inner cavity of the piston body of the utility model;

[0020] Figure 6 This is a schematic diagram of the valve core structure of the utility model.

[0021] In the figure: 1. Piston body; 2. Valve body; 3. Rotating handle; 4. Liquid inlet; 5. Impurity filter; 6. Sealing sleeve; 7. Air duct; 8. Valve core; 9. Inflating ring; 10. Spring; 11. Guide rod; 12. Threaded block; 13. Screw rod; 14. Pressure sensor 2; 15. Pressure sensor 1; 16. Guide pressure plate; 17. Liquid outlet. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] The utility model provides a relief valve for a hydraulic drive system of a loader, comprising a piston body 1 and a valve body 2. The valve body 2 is fixed to the bottom of the piston body 1, and the inner cavity of the piston body 1 is in a connected state with the inner cavity of the valve body 2. The top of the inner cavity of the piston body 1 is movably connected to a screw rod 13, and the top of the screw rod 13 is fixedly connected to a rotating handle 3. When the relief valve is in use, the user can drive the screw rod 13 to rotate by rotating the handle 3.

[0024] The outer ring of the screw rod 13 is threadedly connected to a threaded block 12, and the threaded block 12 is located in the inner cavity of the piston body 1. The bottom of the inner cavity of the piston body 1 is evenly fixedly connected with a guide rod 11. The threaded block 12 and the guide rod 11 are in a movably connected state. Through the setting of the guide rod 11, the rotation of the screw rod 13 can make the threaded block 12 move in the direction of the screw rod 13, thereby making the height value of the threaded block 12 in the piston body 1 change.

[0025] A spring 10 is fixedly connected to the middle of the bottom of the threaded block 12, and a guide pressure plate 16 is fixedly connected to the bottom of the spring 10. The guide pressure plate 16 and the guide rod 11 are in a movably connected state. By setting the guide pressure plate 16, the extension and contraction direction of the spring 10 can be limited to avoid the spring 10 from being misplaced or offset when the relief valve is in use, thereby facilitating the use of the relief valve.

[0026] A pressure sensor 15 and an air-filling ring 9 are fixed to the bottom of the inner cavity of the piston body 1 , and both the pressure sensor 15 and the air-filling ring 9 are located directly below the guide pressure plate 16 .

[0027] The valve core 8 is fixedly connected to the middle portion of the bottom of the guide pressure plate 16. The bottom end of the valve core 8 extends into the inner cavity of the valve body 2. The inner diameter of the valve core 8 is adapted to the inner diameter of the valve body 2, and the valve core 8 and the valve body 2 are in a movable state. A second pressure sensor 14 is fixed to the middle portion of the bottom of the valve core 8. The configuration of the second pressure sensor 14 can detect the pressure of the hydraulic oil on the valve core 8, and thus determine whether the relief valve is in the overflow state or the closed state.

[0028] A sealing sleeve 6 is fixed to the top of the inner cavity of the valve body 2, and the valve core 8 is located in the inner cavity of the sealing sleeve 6. The bottom end of the valve core 8 is fixedly connected to the bottom end of the sealing sleeve 6, and the bottom end of the sealing sleeve 6 is movably connected to the inner cavity of the valve body 2. Under the action of external force, the valve core 8 can drive the sealing sleeve 6 to move, and when the valve core 8 moves upward, the sealing sleeve 6 is in a compressed and expanded state. The sealing sleeve 6 can seal the gap between it and the valve body 2 to prevent hydraulic oil from entering between the sealing sleeve 6 and the valve body 2.

[0029] The bottom end of the piston body 1 is evenly provided with an air channel 7, and the bottom of the inflation ring 9 and the top of the sealing sleeve 6 are both provided with air holes adapted to the air channel 7. Through the setting of the air holes, the gas in the inflation ring 9 can enter the sealing sleeve 6 under the extrusion of the guide pressure plate 16, causing the sealing sleeve 6 to expand, and then the sealing sleeve 6 and the valve body 2 to fit tightly.

[0030] A liquid inlet 4 is provided at the bottom of the inner cavity of the valve body 2, and an impurity filter 5 is provided at one end of the liquid inlet 4. Through the provision of the impurity filter 5, the impurity filter 5 can filter the hydraulic oil entering the valve body 2, preventing impurities from clogging the relief valve. The inner diameter of the liquid inlet 4 is larger than the inner diameter of the valve body 2, which increases the filtering area of ​​the impurity filter 5, facilitating the pressure relief of the relief valve. A liquid outlet 17 is provided on one side of the inner cavity of the valve body 2, through which the hydraulic oil from multiple heads can be discharged.

[0031] When the overflow valve is in use, the liquid outlet 17 is sealed by the valve core 8, that is, when the bottom of the valve core 8 is located below the liquid outlet 17, the bottom of the guide pressure plate 16 is tightly fitted with the bottom of the inner cavity of the piston body 1. Therefore, the user can judge whether the spring 10 has elastic fatigue based on the values ​​detected by both pressure sensor 1 15 and pressure sensor 2 14, which facilitates the user to replace the spring 10 in time. When the overflow valve is in the closed state, the detection value range of pressure sensor 1 15 and the detection range of pressure sensor 2 14 are fixed. When the value detected by pressure sensor 2 14 is within the detection range, and the value detected by pressure sensor 1 15 is outside the detection range, the user can judge that the thrust value of the spring 10 on the guide pressure plate 16 is less than the normal value, and further judge that the spring 10 is in a state of elastic fatigue and needs to be replaced.

[0032] The electrical components involved in this application are all existing technologies. Those skilled in the art are familiar with their connection methods. Through these people, all the electrical components in this application are connected to their corresponding power supplies through wires, and according to actual conditions, appropriate controllers are selected to meet control requirements. The specific connections and control sequences are described below. The electrical connections between the electrical components are completed in a sequential working order. The detailed connection methods are well known in the art. The following mainly introduces the working principles and processes, and no further explanation of electrical control is given.

[0033] To sum up: when the loader hydraulic drive system is used with a relief valve, when the pressure in the loader hydraulic drive system increases to a set value, the hydraulic oil will squeeze the valve core 8 upward, and the valve core 8 drives the sealing sleeve 6 to move upward. The liquid outlet 17 can be in an open state, and the excess hydraulic oil is discharged through the liquid outlet 17 until the squeezing force of the hydraulic oil on the valve core 8 is the same as the squeezing force of the spring 10 on the valve core 8. During the upward movement of the valve core 8, the guide pressure plate 16 is driven to move upward, and the pressure of the guide pressure plate 16 on the inflation ring 9 and the pressure sensor 14 is released. The excess gas in the sealing sleeve 6 can flow back to the inflation ring 9 along the airway 7. When the pressure in the loader's hydraulic drive system is less than the thrust of the spring 10 on the valve core 8, the rebound force of the spring 10 drives the valve core 8 downward until the force on the valve core 8 is balanced, and when the relief valve is in a closed state, the guide pressure plate 16 squeezes the pressure sensor 15, and the hydraulic oil squeezes the pressure sensor 2 14. Based on the values ​​detected by the pressure sensor 2 14 and the pressure sensor 1 15, it can be determined whether the spring 10 is in a state of elastic fatigue, which facilitates the timely replacement of the spring 10.

[0034] The standard parts used in the present invention can all be purchased from the market, and special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the existing technology. The machinery, parts and equipment all adopt conventional models in the existing technology and will not be described in detail here. The content not described in detail in this specification belongs to the existing technology known to professional and technical personnel in this field. Although the embodiments of the present invention have been shown and described, it can be understood by ordinary technicians in this field that various changes, modifications, substitutions and modifications can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A relief valve for a loader hydraulic drive system, comprising a piston body (1) and a valve body (2), characterized in that: The bottom of the piston body (1) is fixed with a valve body (2), the top of the inner cavity of the piston body (1) is movably connected with a screw rod (13), the bottom end of the screw rod (13) is threadedly connected with a threaded block (12), the bottom of the threaded block (12) is fixedly connected with a spring (10), the bottom of the spring (10) is fixedly connected with a valve core (8), the bottom end of the valve core (8) extends into the inner cavity of the valve body (2), the middle part of the bottom of the valve core (8) is fixed with a pressure sensor 2 (14), the outer ring of the top of the valve core (8) is fixed with a guide pressure plate (16), the bottom of the inner cavity of the piston body (1) is fixed with a guide rod (11), a pressure sensor 1 (15) and an inflation ring (9), the guide pressure plate (16) and the threaded block (12) are both movably connected to the guide rod (11), and the pressure sensor 1 (15) and the inflation ring (9) are both located directly below the guide pressure plate (16); A liquid inlet (4) is provided at the bottom of the inner cavity of the valve body (2), an impurity filter (5) is provided at one end of the liquid inlet (4), a liquid outlet (17) is provided on one side of the inner cavity of the valve body (2), a sealing sleeve (6) is fixed at the top end of the inner cavity of the valve body (2), the valve core (8) is fixedly connected to the bottom end of the sealing sleeve (6), and the inner cavity of the sealing sleeve (6) is connected to the inner cavity of the inflation ring (9) through an airway (7).

2. The overflow valve for a loader hydraulic drive system according to claim 1, characterized in that: The bottom end of the sealing sleeve (6) is movably connected to the inner cavity of the valve body (2), and the bottom of the sealing sleeve (6) is located below the liquid outlet (17).

3. The overflow valve for a loader hydraulic drive system according to claim 1, characterized in that: The inner diameter of the liquid inlet (4) is larger than the inner diameter of the valve body (2); and the top of the screw rod (13) is fixedly connected to a rotating handle (3).

4. The overflow valve for a loader hydraulic drive system according to claim 1, characterized in that: The valve core (8) is located in the inner cavity of the sealing sleeve (6), and the inner diameter of the valve core (8) is adapted to the inner diameter of the valve body (2).

5. The overflow valve for a loader hydraulic drive system according to claim 1, characterized in that: The bottom end of the piston body (1) is evenly provided with an air channel (7), and the bottom of the inflation ring (9) and the top of the sealing sleeve (6) are both provided with ventilation holes adapted to the air channel (7).

6. The overflow valve for a loader hydraulic drive system according to claim 1, characterized in that: When the guide pressure plate (16) is tightly fitted to the bottom of the inner cavity of the piston body (1), the bottom of the valve core (8) is located below the liquid outlet (17).

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