A hydraulic system oil return structure for a loader

Abstract

A loader hydraulic system oil return structure, including oil return oil collecting block, radiator, oil return filter element, hydraulic oil tank and check valve, the oil return oil collecting block inside has main oil return channel, radiator oil inlet channel, radiator oil return channel, first oil return channel and second oil return channel that are all connected to the surface of oil return oil collecting block, in the oil return oil collecting block, the main oil return channel is connected with the radiator oil inlet channel and the second oil return channel respectively, and the radiator oil return channel is connected with the first oil return channel, the second oil return channel is connected with the hydraulic oil tank after the check valve is installed at the outer end of the surface of the oil return oil collecting block, the check valve is one-way conducted to the direction of the first oil return channel flowing to the hydraulic oil tank, and the opening pressure of the check valve is adjustable, thereby, when the oil pressure is too large, the check valve can be opened to flow back to the hydraulic oil tank to discharge oil, so as to protect the hydraulic elements such as the radiator and the oil return filter element, and improve the service life of the elements.

Description

Technical Field

[0001] This utility model relates to the technical field of hydraulic systems for loaders, and in particular to a return oil structure for a hydraulic system for loaders. Background Technology

[0002] The hydraulic system of a loader typically consists of a hydraulic pump, control valves, actuators, and return oil devices such as an oil tank, pipelines, radiator, and filter. The return oil flow rate of a loader dynamically changes with operating conditions and engine speed: at high speeds, the hydraulic pump output flow rate increases, and the return oil flow rate increases accordingly; simultaneously, when actuators (such as the boom) descend rapidly, the high-pressure oil in the chamber is quickly discharged, which may also cause a sudden surge in return oil flow rate. Excessive return oil pressure can cause radiator weld cracks or core deformation, and filters are prone to element collapse or abnormal opening of bypass valves under high pressure. In other words, the pressure shock caused by high return oil flow rate can easily lead to structural damage to the radiator and filter element, ultimately resulting in decreased reliability and premature failure of the hydraulic system. Utility Model Content

[0003] The purpose of this utility model is to provide a hydraulic system return oil structure for a loader that can cope with high return oil pressure, effectively protect hydraulic components, improve component service life, and ensure reliable operation of the hydraulic system.

[0004] To achieve the above objectives, the solution of this utility model is: A hydraulic system return oil structure for a loader includes a return oil collection block, a radiator, a return oil filter element, a hydraulic oil tank, and a check valve; The oil return and collection block has a main oil return channel, a radiator oil inlet channel, a radiator oil return channel, a first oil return channel, and a second oil return channel that are all connected to the surface of the oil return and collection block. Inside the oil return and collection block, the main oil return channel is connected to the radiator oil inlet channel and the second oil return channel, and the radiator oil return channel is connected to the first oil return channel. The main return oil channel is connected to the external system's main return oil channel; The radiator oil inlet channel and the radiator oil return channel are respectively connected to the input end and the output end of the radiator; The first return oil channel is connected to the hydraulic oil tank, and the return oil filter element is installed between the first return oil channel and the hydraulic oil tank; The second return oil channel is connected to the hydraulic oil tank after the one-way valve is installed at the outer end of the return oil collection block. The one-way valve guides the flow of the first return oil channel to the hydraulic oil tank in one direction, and the opening pressure of the one-way valve is adjustable.

[0005] Furthermore, the lower part of the oil return collection block is provided with a main oil return channel, a radiator oil inlet channel, and a second oil return channel. The main oil return channel is centrally located and connects downward to the bottom surface of the oil return collection block to form a main inlet. The radiator oil inlet channel and the second oil return channel are respectively located on the left and right sides of the main oil return channel and connect to the sides of the oil return collection block to form side oil inlets and second oil return outlets. The upper part of the oil return collection block is provided with a radiator oil return channel and a first oil return channel. The radiator oil return channels are spaced apart above the radiator oil inlet and connect in the same direction to the sides of the oil return collection block to form side oil return outlets. The first oil return channels are spaced apart above the oil return collection block and connect to the back of the oil return collection block to form a first oil return outlet.

[0006] Furthermore, mounting connectors are screwed onto the side oil inlet and side oil return ports respectively.

[0007] Furthermore, the one-way valve includes a front valve body, a valve core, a compression spring, and a rear valve body; The front valve body and the rear valve body are respectively provided with a front fluid channel and a rear fluid channel that are connected at both ends. The front fluid passage of the front valve body includes a front flow channel and a rear valve core cavity. The inner diameter of the valve core cavity is larger than the inner diameter of the front flow channel, and a front step surface is formed between the two. The rear fluid passage of the rear valve body includes a front mounting port and a rear flow channel. The inner diameter of the mounting port is larger than the inner diameter of the rear flow channel, and a rear step surface is formed between the two. Furthermore, the inner diameter of the mounting port is larger than the outer diameter of the rear end of the front valve body, and the inner diameter of the rear flow channel is smaller than the inner diameter of the valve core cavity. The rear end of the front valve body is screwed into the mounting port of the rear valve body. The rear end of the front valve body is provided with an external thread, while the mounting port of the rear valve body is provided with an internal thread. The valve core is reciprocally mounted in the valve core cavity, and the compression spring is located between the valve core and the rear step surface to abut against the front end of the valve core, which is close to and presses against the front step surface. The front end of the front valve body is sealed and screwed to the second return port.

[0008] Furthermore, the one-way valve also includes a compression spring seat installed in the valve core cavity; the compression spring seat includes a front shaft and a rear base, the shaft being slidably inserted into a sliding hole provided on the rear side of the valve core; the base abuts against the rear stepped surface, and the base is provided with a flow hole, the flow hole connecting the valve core cavity and the rear flow channel; the compression spring is sleeved on the outer periphery of the compression spring seat and its two ends abut against the valve core and the front side of the base, respectively.

[0009] Furthermore, the rear end of the front valve body is divided into a front sealing part, a middle threaded part, and a rear sealing part with successively decreasing outer diameters. The front sealing part is provided with a front annular groove, the middle threaded part is provided with the external thread, and the rear sealing part is provided with a rear annular groove. O-rings are fitted on both the front and rear annular grooves. The mounting port on the rear valve body is provided with an outer sealing part, a middle threaded part, and an inner sealing part, respectively corresponding to the front sealing part, the middle threaded part, and the rear sealing part.

[0010] Furthermore, the front step surface of the front valve body is an inclined surface; the front end of the valve core is provided with a tapered portion, which fits into the inclined surface; the minimum outer diameter of the tapered portion is smaller than the inner diameter of the front flow channel, and the maximum outer diameter is larger than the inner diameter of the front flow channel but smaller than the inner diameter of the valve core cavity.

[0011] After adopting the above technical solution, when the oil pressure received by the main return oil channel of the return oil collection block of the hydraulic system is too high, the flow of the oil can be divided into two paths. The first path flows to the radiator through the radiator inlet channel, while the second path can open the check valve and flow back to the hydraulic oil tank for oil discharge. In other words, the oil pressure of the main return oil channel can be reduced to prevent the oil pressure of the first path from being too high, thereby protecting the radiator, return oil filter element and other hydraulic components and improving the service life of the components.

[0012] Meanwhile, the check valve is directly installed on the surface of the return oil collection block. It can be selected or adjusted to a check valve with different opening pressure according to the return oil pressure required by different systems, so as to unload oil according to different oil pressures, ensure the smooth operation of the hydraulic system, improve work efficiency, and effectively protect hydraulic components. Attached Figure Description

[0013] Figure 1 This is a structural block diagram of an embodiment of the present utility model; Figure 2 This is a schematic diagram of the connection of the oil return and collection block according to an embodiment of the present utility model; Figure 3 This is a perspective view of the oil return and collection block according to an embodiment of the present utility model; Figure 4 for Figure 2 Enlarged view of point A.

[0014] Labeling: 10 for return oil collection block, 11 for main return oil channel, 111 for main inlet, 12 for radiator inlet channel, 121 for side inlet, 13 for radiator return oil channel, 131 for side return oil port, 14 for first return oil channel, 141 for first return oil port, 15 for second return oil channel, 151 for second return oil port, 20 for radiator, 30 for return oil filter element, 40 for hydraulic oil tank, 50 for check valve, 51 for front valve body, 511 for front fluid channel, 512 for front flow channel, 513 for valve core cavity, 514 for front stepped surface, 515 for external thread. Front sealing part 516, front annular groove 5161, central threaded part 517, rear sealing part 518, rear annular groove 5181, sealing ring 519, valve core 52, tapered part 521, sliding hole 522, compression spring 53, rear valve body 54, rear fluid passage 541, mounting port 542, rear flow channel 543, rear stepped surface 544, internal thread 545, outer sealing part 546, central threaded part 547, inner sealing part 548, compression spring seat 55, shaft 551, base 552, flow hole 553, mounting joint 60. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0016] like Figures 1 to 4 As shown, the hydraulic system return oil structure of a loader in this embodiment includes a return oil collection block 10, a radiator 20, a return oil filter element 30, a hydraulic oil tank 40, and a one-way valve 50.

[0017] The oil return collection block 10 has a main oil return channel 11, a radiator oil inlet channel 12, a radiator oil return channel 13, a first oil return channel 14, and a second oil return channel 15 that are all connected to the surface of the oil return collection block 10. At the same time, inside the oil return collection block 10, the main oil return channel 11 is connected to the radiator oil inlet channel 12 and the second oil return channel 15 respectively, and the radiator oil return channel 13 is connected to the first oil return channel 14.

[0018] The main return oil channel 11 is connected to the external system's main return oil channel and is used for oil collection and return.

[0019] The radiator oil inlet channel 12 and the radiator oil return channel 13 are respectively connected to the input end and the output end of the radiator 20, and are used to cool the oil using the radiator 20.

[0020] The first return oil channel 14 is connected to the hydraulic oil tank 40, and the return oil filter element 30 is provided between the first return oil channel 14 and the hydraulic oil tank 40. The oil that has been cooled down can flow through the first return oil channel 14 to the return oil filter element 30 for filtration, and then flow back to the hydraulic oil tank 40.

[0021] The second return oil channel 15 is connected to the hydraulic oil tank 40 after a one-way valve 50 is installed on the outer end of the return oil collection block 10. The one-way valve 50 guides the flow of the first return oil channel 14 to the hydraulic oil tank 40 in one direction, and the opening pressure of the one-way valve 50 is adjustable.

[0022] Therefore, when the oil pressure received by the main return oil channel 11 of the return oil collection block 10 is too high, the flow of the oil can be divided into two paths. The first path flows to the radiator 20 through the radiator inlet channel 12, while the second path can open the check valve 50 and flow back to the hydraulic oil tank 40 for oil discharge. In other words, the oil pressure in the main return oil channel 11 can be reduced to prevent the oil pressure in the first path from being too high, thereby protecting the hydraulic components such as the radiator 20 and the return oil filter element 30 and improving the service life of the components.

[0023] Meanwhile, the check valve 50 is directly installed on the surface of the return oil collection block 10. Different check valves 50 with different parameters can be selected according to the return oil pressure required by different systems to unload oil according to different oil pressures, ensuring the smooth operation of the hydraulic system, improving work efficiency, and effectively protecting hydraulic components.

[0024] In this embodiment, the oil return collection block 10 can be rectangular in shape, with a main oil return channel 11, a radiator oil inlet channel 12, and a second oil return channel 15 arranged at its lower part. The main oil return channel 11 is centrally located and connects downward to the bottom surface of the oil return collection block 10 to form a main inlet 111. The radiator oil inlet channel 12 and the second oil return channel 15 are respectively located on the left and right sides of the main oil return channel 11, and respectively connect to the side surfaces of the oil return collection block 10 to form a side oil inlet 121 and a second oil return outlet 151. The upper part of the oil return collection block 10 is provided with a radiator oil return channel 13 and a first oil return channel 14. The radiator oil return channel 13 can be arranged at intervals above the oil inlet of the radiator 20 and connected in the same direction to the side of the oil return collection block 10 to form a side oil return port 131. The first oil return channel 14 can be arranged at intervals above the oil return collection block 10 and connected to the back of the oil return collection block 10 to form a first oil return port 141. Of course, the specific layout can be set according to the pipeline connection needs.

[0025] Meanwhile, mounting connectors 60 can be screwed onto the side oil inlet 121 and the side oil return port 131 respectively, so as to connect them to the radiator 20 through pipe fittings.

[0026] The check valve 50 can be threaded onto the second return port 151 to facilitate replacement with a check valve 50 with a different opening pressure.

[0027] See Figure 3 and Figure 4 In this embodiment, the one-way valve 50 includes a front valve body 51, a valve core 52, a compression spring 53, and a rear valve body 54.

[0028] The front valve body 51 and the rear valve body 54 are respectively provided with a front fluid channel 511 and a rear fluid channel 541 that are connected at both ends. The front fluid passage 511 of the front valve body 51 includes a front flow channel 512 and a rear valve core cavity 513. The inner diameter of the valve core cavity 513 is larger than the inner diameter of the front flow channel 512, and a front stepped surface 514 is formed between the two. The rear fluid passage 541 of the rear valve body 54 includes a front mounting port 542 and a rear flow channel 543. The inner diameter of the mounting port 542 is larger than the inner diameter of the rear flow channel 543, and a rear stepped surface 544 is formed between the two.

[0029] Furthermore, the inner diameter of the mounting port 542 is larger than the outer diameter of the rear end of the front valve body 51, and the inner diameter of the rear flow channel 543 is smaller than the inner diameter of the valve core cavity 513.

[0030] The rear end of the front valve body 51 can be screwed into the mounting port 542 of the rear valve body 54. The rear end of the front valve body 51 can be provided with an external thread 515, while the mounting port 542 of the rear valve body 54 is provided with an internal thread 545 so that the two can be screwed together.

[0031] The valve core 52 is reciprocally mounted in the valve core cavity 513. The compression spring 53 is located between the valve core 52 and the rear step surface 544, and is used to push the front end of the valve core 52 close to the front step surface 514 to perform a movable blockage between the front flow channel 512 and the valve core cavity 513.

[0032] The front end of the front valve body 51 can be sealed and screwed to the second return port 151, and the rear end of the rear valve body 54 can be used to connect pipes and communicate with the hydraulic oil tank 40.

[0033] Therefore, when the oil pressure in the main return oil channel 11 is too high, the valve core 52 can be pushed against the second return oil port 151 to overcome the elastic force of the compression spring 53 and move towards the rear flow channel 543 to open the seal, so that the oil can flow to the front flow channel 512, the valve core cavity 513 and the rear flow channel 543, thereby realizing unidirectional flow.

[0034] In this embodiment, the front step surface 514 of the front valve body 51 is an inclined surface; the front end of the valve core 52 is provided with a tapered part 521, which fits into the inclined surface; the minimum outer diameter of the tapered part 521 is smaller than the inner diameter of the front flow channel 512, and the maximum outer diameter is larger than the inner diameter of the front flow channel 512 but smaller than the inner diameter of the valve core cavity 513, so as to achieve good sealing.

[0035] The one-way valve 50 may further include a spring seat 55 installed in the valve core cavity 513; the spring seat 55 includes a front shaft 551 and a rear base 552, the shaft 551 is slidably inserted into the sliding hole 522 provided on the rear side of the valve core 52, which can improve the stability of the valve core 52 sliding back and forth; the base 552 abuts against the rear step surface 544, and the base 552 is provided with a flow hole 553, which connects the valve core cavity 513 and the rear flow channel 543; the spring 53 is sleeved on the outer periphery of the spring seat 55 and its two ends abut against the valve core 52 and the front side of the base 552 respectively.

[0036] Furthermore, the front valve body 51 and the rear valve body 54 can be connected by an adjustable threaded connection. The rear end of the front valve body 51 is divided into a front sealing part 516, a middle threaded part 517, and a rear sealing part 518, with the outer diameter decreasing sequentially. The front sealing part 516 is provided with a front annular groove 5161, and an O-ring seal 519 is fitted on the front annular groove 5161. The middle threaded part 517 is provided with the external thread 515. The rear sealing part 518 is provided with a rear annular groove 5181, and an O-ring seal 519 is fitted on the rear annular groove 5181. The rear valve body 54 has a mounting port 542. The valve body 50 has an outer sealing part 546, a middle threaded part 547, and an inner sealing part 548, which correspond to the front sealing part 516, the middle threaded part 517, and the rear sealing part 518, respectively. The middle threaded part 547 is provided with the internal thread 545. The outer sealing part 546 and the inner sealing part 548 are used to cooperate and press against the sealing ring 519. Thus, the number of threads between the rear valve body 54 and the front valve body 51 can be adjusted by rotating the valve body 54 back and forth, thereby adjusting the compression degree of the pressure spring 53, thereby adjusting the opening pressure of the one-way valve 50. The sealing ring 519 ensures the sealing effect.

[0037] In summary, after adopting the oil return structure of this embodiment, taking a loader as an example, its oil return flow rate changes dynamically with the working conditions and engine speed: when the speed is high, the hydraulic pump output flow rate increases, and the oil return flow rate increases synchronously; when the actuator (such as the boom) descends rapidly, the oil in the high-pressure chamber is discharged quickly, which may cause the oil return flow rate to surge instantaneously.

[0038] Routine operation: Engine speed (750~1300rpm): oil return flow rate is about 110~200L / min, oil return pressure is usually <2bar.

[0039] Rated speed (~2200rpm): The return oil flow rate can reach 320~400L / min. Without pressure control, the return oil pressure may rise to 4~6bar, and the peak pressure may even exceed 15bar (such as when the boom is lowered).

[0040] Extreme operating conditions: During loading operations or rapid boom descent, the return oil flow rate can instantaneously reach 400-600 L / min, causing a sudden increase in return oil line pressure. Actual measurement data shows that under such conditions, the peak return oil pressure can exceed 15 bar, while the continuous pressure may remain above 6 bar.

[0041] Hydraulic component requirements: Modern hydraulic components (such as proportional valves and servo valves) require a continuous return pressure of ≤3 bar to avoid seal damage, valve core 52 sticking, or response delay. Radiator 20 and filter limitations: The peak pressure allowed for radiator 20 is typically <10 bar.

[0042] At this time, a check valve 50 is used, with an opening pressure set to 2.5~3.0 bar (adjustable). It is installed between the second return oil channel 15 and the hydraulic oil tank 40 for oil unloading. The check valve 50 also features a dynamic response: valve opening time <20ms, ensuring that the pressure peak is always controlled below 10 bar.

[0043] Working principle and flow distribution: When the return oil pressure is ≤3.0 bar, the check valve 50 closes, and all oil returns to the hydraulic oil tank 40 via the radiator 20 / filter.

[0044] When the return oil pressure is greater than 3.0 bar, the check valve 50 opens, and part of the oil (about 100 to 150 L / min) is directly discharged back to the hydraulic oil tank 40 through this valve, while the remaining oil (maintaining the pipeline pressure ≤ 3 bar) continues to flow through the radiator 20.

[0045] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected by this utility model. It should be noted that for those skilled in the art, equivalent changes and modifications without departing from the principle of this utility model should still fall within the protection scope of this utility model.

[0046] In the description of the embodiments of this application, it should be understood that the indicated orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships commonly used when the product is in use, or the orientations or positional relationships commonly understood by those skilled in the art. These are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or component 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 application. In the description of this application, "a plurality of" and "several" mean two or more, unless otherwise explicitly specified.

Claims

1. A hydraulic system return oil structure for a loader, comprising a return oil collection block, a radiator, a return oil filter element, and a hydraulic oil tank; Its features are: It also includes check valves; The oil return and collection block has a main oil return channel, a radiator oil inlet channel, a radiator oil return channel, a first oil return channel, and a second oil return channel that are all connected to the surface of the oil return and collection block. Inside the oil return and collection block, the main oil return channel is connected to the radiator oil inlet channel and the second oil return channel, and the radiator oil return channel is connected to the first oil return channel. The main return oil channel is connected to the external system's main return oil channel; The radiator oil inlet channel and the radiator oil return channel are respectively connected to the input end and the output end of the radiator; The first return oil channel is connected to the hydraulic oil tank, and the return oil filter element is installed between the first return oil channel and the hydraulic oil tank; The second return oil channel is connected to the hydraulic oil tank after the one-way valve is installed at the outer end of the return oil collection block. The one-way valve guides the flow of the first return oil channel to the hydraulic oil tank in one direction, and the opening pressure of the one-way valve is adjustable.

2. The hydraulic system return oil structure for a loader according to claim 1, characterized in that: The lower part of the oil return collection block is provided with a main oil return channel, a radiator oil inlet channel, and a second oil return channel. The main oil return channel is centrally located and connects downward to the bottom surface of the oil return collection block to form a main inlet. The radiator oil inlet channel and the second oil return channel are respectively located on the left and right sides of the main oil return channel and connect to the sides of the oil return collection block to form side oil inlets and second oil return outlets. The upper part of the oil return collection block is provided with a radiator oil return channel and a first oil return channel. The radiator oil return channels are spaced apart above the radiator oil inlet and connect in the same direction to the sides of the oil return collection block to form side oil return outlets. The first oil return channel is spaced apart above the oil return collection block and connects to the back of the oil return collection block to form a first oil return outlet.

3. The hydraulic system return oil structure for a loader according to claim 2, characterized in that: The side oil inlet and side oil return ports are respectively screwed with mounting connectors.

4. The hydraulic system return oil structure for a loader according to claim 1, characterized in that: The one-way valve includes a front valve body, a valve core, a compression spring, and a rear valve body; The front valve body and the rear valve body are respectively provided with a front fluid channel and a rear fluid channel that are connected at both ends. The front fluid passage of the front valve body includes a front flow channel and a rear valve core cavity. The inner diameter of the valve core cavity is larger than the inner diameter of the front flow channel, and a front step surface is formed between the two. The rear fluid passage of the rear valve body includes a front mounting port and a rear flow channel. The inner diameter of the mounting port is larger than the inner diameter of the rear flow channel, and a rear step surface is formed between the two. Furthermore, the inner diameter of the mounting port is larger than the outer diameter of the rear end of the front valve body, and the inner diameter of the rear flow channel is smaller than the inner diameter of the valve core cavity. The rear end of the front valve body is screwed into the mounting port of the rear valve body. The rear end of the front valve body is provided with an external thread, while the mounting port of the rear valve body is provided with an internal thread. The valve core is reciprocally mounted in the valve core cavity, and the compression spring is located between the valve core and the rear step surface to abut against the front end of the valve core, which is pressed against the front step surface. The front end of the front valve body is sealed and screwed to the second return port.

5. The hydraulic system return oil structure for a loader according to claim 4, characterized in that: The one-way valve also includes a spring seat installed in the valve core cavity; the spring seat includes a front shaft and a rear base, the shaft being slidably inserted into a sliding hole provided on the rear side of the valve core; the base abuts against the rear stepped surface, and the base is provided with a flow hole that connects the valve core cavity and the rear flow channel; the spring is sleeved on the outer periphery of the spring seat and its two ends abut against the valve core and the front side of the base, respectively.

6. The hydraulic system return oil structure for a loader according to claim 4, characterized in that: The rear end of the front valve body is divided into a front sealing part, a middle threaded part, and a rear sealing part with successively smaller outer diameters. The front sealing part is provided with a front annular groove, the middle threaded part is provided with the external thread, and the rear sealing part is provided with a rear annular groove. O-rings are fitted on both the front and rear annular grooves. The mounting port on the rear valve body is provided with an outer sealing part, a middle threaded part, and an inner sealing part, respectively corresponding to the front sealing part, the middle threaded part, and the rear sealing part.

7. The hydraulic system return oil structure for a loader according to claim 4, characterized in that: The front step surface of the front valve body is an inclined surface; the front end of the valve core is provided with a tapered part, which fits into the inclined surface; the minimum outer diameter of the tapered part is smaller than the inner diameter of the front flow channel, and the maximum outer diameter is larger than the inner diameter of the front flow channel but smaller than the inner diameter of the valve core cavity.

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