A hydraulic cylinder testing device and method

Abstract

A hydraulic cylinder testing device and method are disclosed, relating to the field of hydraulic cylinder durability testing technology. The device includes a mounting frame, a quick-release locking device, and a load simulation mechanism. The quick-release locking device utilizes a bidirectional screw to drive a slider positioning pin, achieving efficient mounting and significantly reducing the mounting time for a single component. The load simulation mechanism, through a multi-hole adapter plate and a universal adjustable connecting rod, allows for the application of different shaft loads by simply changing the pin position, without replacing any parts, thus simulating actual working conditions. This invention alternates between two load simulation conditions to simulate the complex stresses throughout the entire lifecycle of a vehicle steering system, ensuring that the test data closely matches actual wear, providing a high-confidence basis for structural optimization of hydraulic cylinder seals and stroke sensing rings. The passive load power source can adjust the load force, further optimizing the accuracy of the test results.

Description

Technical Field

[0001] This invention relates to the field of hydraulic cylinder durability testing technology, and in particular to a hydraulic cylinder testing device and testing method. Background Technology

[0002] With the increasing demands for reliability in steering systems of construction machinery, agricultural equipment, and special vehicles, the durability and fatigue life of dual-output steering cylinders, as key actuators, have become core indicators for evaluating overall machine quality. To fully expose potential defects and verify design margins before product finalization, OEMs and component suppliers generally need to conduct mass static pressure and durability tests. However, existing testing methods reveal the following three prominent problems in practice:

[0003] 1. Low clamping efficiency and easy damage:

[0004] Currently, the testing fixtures for dual-output steering cylinders still primarily use the traditional method of "fixed bracket + bolt pressure plate". Since the piston rods at both ends of the test piece must be exposed and simultaneously loaded, installation requires repeatedly inserting multiple sets of high-strength bolts and applying the specified torque, often taking more than 5 minutes per assembly and disassembly. In scenarios involving large-scale, high-frequency testing, the cumulative assembly and disassembly time significantly extends the testing cycle. Simultaneously, the threaded holes and bolt heads of the testing fixture experience wear and scratches during repeated tightening and loosening, leading to decreased positioning accuracy and even damage to the testing fixture, directly affecting the smooth progress of the test.

[0005] 2. Deviation between loading boundary and actual working conditions:

[0006] Most existing devices employ coaxial tension / compression loading or single-sided cantilever loading, making it difficult to reproduce the eccentric loading and bending moments caused by suspension bounce and frame deformation during vehicle operation. As a result, the fatigue life obtained from tests is far higher than market feedback values, and early failure issues in the field cannot be identified in advance. Some laboratories have attempted to generate additional bending moments by connecting spherical bearings or shims in series at the cylinder end, but these structures are fragmented, adjustments are discrete, and disassembly and reassembly are required each time the operating conditions are changed, resulting in low efficiency.

[0007] 3. The load simulation system is complex and consumes a lot of energy:

[0008] To achieve continuous and stable load capacity, traditional solutions generally employ servo hydraulic stations or electric cylinder closed-loop control. While these active systems offer high precision, they require high-power motors, high-pressure pump stations, and cooling systems. The equipment is bulky, energy-intensive, and noisy, and long-term operation results in high maintenance costs. In scenarios involving small-tonnage, high-volume endurance testing, their economic viability is severely compromised.

[0009] In summary, the industry urgently needs a comprehensive hydraulic cylinder testing device that features quick clamping, adjustable off-center load, and adjustable load capacity to resolve the contradiction between efficiency, authenticity, and economy in batch and durability testing using traditional devices. Summary of the Invention

[0010] To overcome the shortcomings of the prior art, the present invention discloses a hydraulic cylinder testing device and testing method.

[0011] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0012] A hydraulic cylinder testing device and method for testing the durability of a dual-output steering cylinder, characterized in that it comprises:

[0013] Fixture;

[0014] A quick-release locking device is fastened to one side of the fixed frame; it is used to quickly mount the dual-outlet steering cylinder onto the fixed frame.

[0015] The load simulation mechanism consists of two parts, each mounted on one side of the fixed frame; it is used to provide load forces that are not on the same axis as the two ends of the dual-output steering cylinder.

[0016] The load simulation mechanism includes:

[0017] The adapter plate is hinged to the corresponding fixing frame; one end of the adapter plate is provided with a pin hole, and the other end is provided with multiple mounting holes at intervals;

[0018] The universal adjustable connecting rod has one end universally connected to one end of the double-outlet steering cylinder; the other end is hinged to one of the mounting holes of the adapter plate.

[0019] The load-bearing telescopic cylinder has one end hinged to the fixed frame and the other end hinged to the pin hole of the adapter plate.

[0020] A passive load power source, in conjunction with a load telescopic cylinder, provides load force to the dual-output steering cylinder; the passive load power source requires no external power input.

[0021] Preferably, the load-bearing telescopic cylinder comprises:

[0022] The cylinder block has a piston chamber inside;

[0023] The piston is slidably connected to the cylinder body;

[0024] The piston rod has one end connected to the piston and the other end extending out of the cylinder.

[0025] Preferably, the passive load power source includes:

[0026] The adjusting rod is rotatably connected to the end of the cylinder body away from the piston rod extension end, and one end of the adjusting rod extends into the piston chamber;

[0027] The limiting plate is threadedly connected to one end of the adjusting rod located inside the piston chamber;

[0028] The sliding key is fastened to the limiting plate on one side and slidably connected to the piston chamber on the other side.

[0029] A spring is installed in the piston chamber between the limiting plate and the piston. The compression of the spring is adjusted by adjusting the position of the limiting plate on the adjusting rod, thereby adjusting the maximum load force of the passive load power source.

[0030] Preferably, the passive load power source includes:

[0031] The oil tank is used to store hydraulic oil. The oil tank is connected to the piston chamber of the cylinder through an inlet pipe and an outlet pipe, and both the inlet pipe and the outlet pipe are equipped with check valves.

[0032] The relief valve is installed on the oil outlet pipe; the load force of the passive load power source is adjusted by regulating the pressure of the relief valve.

[0033] Preferably, the passive load power source includes:

[0034] Two hydraulic elastic balloons are respectively located in the piston chambers of two cylinders; the two hydraulic elastic balloons are connected by corresponding pipelines.

[0035] A two-way relief valve is installed on the pipeline between two hydraulic elastic balloons; the load force of the passive load power source is adjusted by regulating the pressure of the two-way relief valve.

[0036] Preferably, the universal adjustable connecting rod includes:

[0037] The universal ball joint connector has a groove at the end of the ball joint away from the ball joint;

[0038] The connecting pipe is fastened to the corresponding ball head;

[0039] The connecting rod is inserted into the connecting pipe and threadedly connected to the connecting pipe;

[0040] The hinged joint is installed at the extended end of the connecting rod.

[0041] Preferably, the quick-release locking device includes:

[0042] A fixed base is securely connected to a fixed frame; the fixed base has an installation cavity, and sliding grooves are provided on both sides corresponding to the installation cavity;

[0043] Two sliders are respectively engaged with two sliding grooves;

[0044] The locating pin is installed on one side of the slider; when installing the double-outlet steering cylinder, the locating pin is inserted into the mounting hole of the double-outlet steering cylinder.

[0045] A bidirectional screw is installed in the mounting cavity of the fixed base and is rotatably connected to the fixed base;

[0046] Two threaded sleeves are threadedly connected to the positive and negative thread sections of the bidirectional screw, respectively; the two threaded sleeves are synchronously driven to move closer or further apart by turning the bidirectional screw.

[0047] The connecting rod is hinged at one end to the slider and at the other end to the threaded sleeve. When the two threaded sleeves move away from each other, they drive the two sliders to retract into the groove. When the two threaded sleeves move closer to each other, they drive the two sliders to push out of the groove, and the sliders can correspond to and abut against the mounting bracket of the double-outlet steering cylinder.

[0048] Preferably, the front side of the fixed seat is provided with a dovetail-shaped groove, and a support for supporting and limiting the double-outlet steering cylinder is slidably connected in the dovetail-shaped groove. A locking bolt for locking the support is threaded on the support.

[0049] Preferably, the bottom of the fixing frame is provided with an oil receiving box, which is placed on the workbench; the workbench is provided with a hydraulic station for providing test power to the dual-outlet steering cylinder; and an oil storage tank corresponding to and connected to the oil receiving box is provided on one side of the hydraulic station.

[0050] The testing method using a hydraulic cylinder testing device includes the following steps:

[0051] S1. Mounting and connecting: The double-outlet steering cylinder is mounted on the fixed frame using a quick-release locking device; the inlet and outlet oil connectors of the double-outlet steering cylinder are connected to the corresponding hydraulic station via hydraulic oil pipes.

[0052] S2. Static pressure test: Start the hydraulic station and inject hydraulic oil into the piston chamber of the double-outlet steering cylinder. The injection pressure should be greater than 35MPa. Let it stand for 5 to 10 minutes and check whether there is any oil leakage at both ends of the double-outlet steering cylinder.

[0053] S3. Durability test: Connect the two ends of the double-outlet steering cylinder to two load simulation mechanisms respectively; control the reciprocating motion of the double-outlet steering cylinder through a solenoid valve. During the reciprocating motion of the double-outlet steering cylinder, the two load simulation mechanisms provide load forces that are not on the same axis as the double-outlet steering cylinder to the two ends of the double-outlet steering cylinder respectively, simulating the actual working conditions.

[0054] Load simulation is divided into two cases;

[0055] The first method involves connecting two universal adjustable connecting rods to the mounting holes at the same position on the two adapter plates, ensuring that the load conditions at both ends of the dual-outlet steering cylinder are the same.

[0056] The second method involves connecting two universal adjustable connecting rods to the mounting holes at different positions on the two adapter plates, thus differentiating the load conditions at both ends of the dual-outlet steering cylinder.

[0057] Two load simulation conditions were performed alternately.

[0058] By employing the technical solution described above, the present invention has the following beneficial effects:

[0059] (1) The quick-installation locking device of the present invention uses a fixed base as a reference and a bidirectional screw to drive a cross linkage to drive the slider to extend and retract synchronously, so that the positioning pin is aligned with and inserted into the mounting hole of the double-outlet steering cylinder at one time. With the help of the support that can slide up and down, the height and hole position are adaptively adjusted, realizing "one-time adjustment and batch clamping". This structure eliminates the wear and hole error caused by repeated disassembly and assembly of traditional bolts, and shortens the clamping time of a single part from minutes to seconds. It significantly improves the cycle efficiency and equipment utilization in large-scale continuous operation of static pressure testing, while avoiding the reduction in connection reliability caused by thread fatigue.

[0060] (2) The load simulation mechanism of this invention, through the hinged connection between the multi-hole position on the adapter plate and the universal adjustable connecting rod, can apply loads with different axes and bending moments to both ends of the double-outlet steering cylinder without changing any parts, simply by changing the position of the pin. When the adapter plate adopts an arc design, the distance between the hole position and the piston rod end is constant, and the load condition can be switched without adjusting the length of the universal adjustable connecting rod, further shortening the test preparation time. Alternating between the same hole position and different hole position conditions can simulate the complex stress of the vehicle steering system throughout its entire life cycle in 500,000 durability cycles, making the test data highly consistent with the actual wear, and providing a high-confidence basis for the optimization of cylinder seals and structure.

[0061] (3) None of the three passive load power sources of the present invention require an external pump station. Stable load force can be generated in the load telescopic cylinder using springs, overflow valves, or hydraulic elastic balloons. Among them, the spring scheme can obtain linearly increasing load without increasing the cylinder length through the threaded engagement of the adjusting rod and the limiting plate. The hollow piston rod allows the adjusting rod to be built-in, increasing the stroke utilization rate by more than 20%. The overflow valve scheme outputs precise load in a constant back pressure manner, meeting the dual working conditions of static pressure durability. The balloon scheme converts the easily worn piston seal into a high-molecular elastomer with a life of 8 million cycles, completely solving the failure problem of traditional piston seal rings in long-term high-frequency cycles, ensuring continuous and uninterrupted 500,000 durability tests, and significantly reducing maintenance downtime and spare parts costs.

[0062] (4) The present invention further absorbs the spatial angle deviation between the double-outlet steering cylinder and the adapter plate by means of a universal adjustable connecting rod and a universal ball joint connecting seat. The ball joint groove directly fits the piston rod end to avoid jamming. The threaded telescopic structure of the connecting pipe and the connecting rod can steplessly adjust the length within ±100mm, and together with the hinge seat, it can achieve rapid compatibility with cylinders of different specifications. This design enables the testing device to maintain high connection accuracy and freedom of movement without changing any adapter parts when facing multi-specification, small-batch orders, significantly reducing tooling inventory and management complexity. Attached Figure Description

[0063] Figure 1 This is a schematic diagram of the structure of the present invention;

[0064] Figure 2 This is a schematic diagram of the structure of a dual-outlet steering cylinder;

[0065] Figure 3 This is a schematic diagram of the load simulation mechanism;

[0066] Figure 4 A schematic diagram of the universal adjustable connecting rod;

[0067] Figure 5 A three-dimensional structural schematic diagram of a load-bearing telescopic cylinder;

[0068] Figure 6 This is a schematic diagram of the internal structure of the first type of load-bearing telescopic cylinder;

[0069] Figure 7 This is a schematic diagram of the internal structure of the second type of load-bearing telescopic cylinder;

[0070] Figure 8 This is a schematic diagram of the internal structure of the third type of load telescopic cylinder;

[0071] Figure 9 A schematic diagram of the internal structure of the quick-release locking device;

[0072] Figure 10 This is a schematic diagram of the support installation structure;

[0073] Figure 11 A schematic diagram of the usage state of the present invention.

[0074] In the diagram: 1. Fixed frame; 2. Quick-release locking device; 2-1. Fixed seat; 2-2. Slider; 2-3. Positioning pin; 2-4. Two-way screw; 2-5. Screw sleeve; 2-6. Connecting rod; 2-7. Support; 2-8. Locking bolt; 3. Adapter plate; 4. Universal adjustable connecting rod; 4-1. Universal ball joint connector; 4-2. Connecting pipe; 4-3. Connecting rod; 4-4. Hinge seat; 5. Load telescopic cylinder; 5-1. Cylinder body; 5-2. Piston; 5-3. Piston rod; 6. Spring; 7. Limiting plate; 8. Adjusting rod; 9. Sliding key; 10. Oil tank; 11. Overflow valve; 12. Hydraulic elastic ball bladder; 13. Two-way overflow valve; 14. Oil receiving box; 15. Workbench; 16. Hydraulic station; 17. Oil storage tank; 18. Double-outlet steering cylinder. Detailed Implementation

[0075] 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0076] In the description of this invention, it should be noted that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to 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.

[0077] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0078] Example 1:

[0079] Combined with appendix Figures 1-3According to standards 5-8, a hydraulic cylinder testing device and method are disclosed, comprising a fixed frame 1, a quick-release locking device 2, and a load simulation mechanism. The fixed frame 1 serves as the mounting base for the entire device, and the quick-release locking device 2 is installed on one side of it. The design highlight of this device is its ability to easily and quickly fix the dual-output steering cylinder 18 onto the fixed frame 1 without relying on traditional bolt connections, thus effectively improving installation efficiency and avoiding wear problems that may be caused by repeated bolt disassembly. This advantage is particularly evident in batch static pressure testing scenarios.

[0080] The structural design of the dual-outlet steering cylinder 18 is shown in the attached figure. Figure 2 As shown, both ends of the piston rod extend from the cylinder body, and a connecting seat is provided on the cylinder body, with mounting holes arranged on the connecting seat. On both sides of the mounting bracket 1, load simulation mechanisms are symmetrically installed. The core function of this load simulation mechanism is to provide load forces at both ends of the dual-outlet steering cylinder 18 that are not aligned with the axis of the dual-outlet steering cylinder 18, thereby simulating the stress state of the dual-outlet steering cylinder 18 under actual working conditions, making the data obtained from the durability test closer to real-world usage scenarios.

[0081] The load simulation mechanism consists of key components such as an adapter plate 3, a universal adjustable connecting rod 4, a load telescopic cylinder 5, and a passive load power source. Specifically, the adapter plate 3 is connected to the fixed frame 1 by a hinge, with a pin hole at one end and multiple mounting holes spaced apart at the other end. One end of the universal adjustable connecting rod 4 is universally connected to the double-outlet steering cylinder 18, and the other end can be hinged to any mounting hole on the adapter plate 3, thereby establishing a force transmission connection between the double-outlet steering cylinder 18 and the adapter plate 3.

[0082] Of particular note is that by connecting the universal adjustable connecting rod 4 to different mounting holes on the adapter plate 3, different operating conditions of the dual-output steering cylinder 18 can be simulated. This is because different connection positions will cause the bending moment borne by the dual-output steering cylinder 18 to vary, thereby affecting its wear.

[0083] During the durability test, if the two universal adjustable connecting rods 4 are installed at the same mounting hole on the two adapter plates 3 respectively, and after a certain number of tests, they are then moved to different mounting holes and the tests are carried out alternately, the accuracy and reliability of the test data can be further improved.

[0084] In addition, the adapter plate 3 can be designed as an arc shape in addition to a long strip structure. In this way, the distance between the multiple mounting holes and the corresponding ends of the double-outlet steering cylinder 18 can be kept equal. Therefore, when selecting mounting holes of different positions, there is no need to make additional adjustments to the length of the universal adjustable connecting rod 4.

[0085] The load telescopic cylinder 5 is mounted on the side of the fixed frame 1 opposite to the dual-outlet steering cylinder 18. One end of the cylinder is hinged to the fixed frame 1, and the other end is hinged to the pin hole of the adapter plate 3. The passive load power source works in conjunction with the load telescopic cylinder 5 to provide the required load force for the dual-outlet steering cylinder 18 without the need for external power input.

[0086] The internal structure of the load telescopic cylinder 5 is shown in the attached figure. Figure 5 and 6 As shown, it mainly includes a cylinder body 5-1, a piston 5-2, and a piston rod 5-3. The cylinder body 5-1 has a piston chamber inside, where the piston 5-2 is slidably connected. One end of the piston rod 5-3 is connected to the piston 5-2, and the other end extends out of the cylinder body 5-1. When the dual-outlet steering cylinder 18 is activated, if it extends towards one end of the fixed frame 1, the load telescopic cylinder 5 at that end of the fixed frame 1 will be compressed. At this time, the passive load power source at that end will provide load force for the extension of the dual-outlet steering cylinder 18. Simultaneously, the passive load power source at the other end of the fixed frame 1 will drive the corresponding load telescopic cylinder 5 to extend, thereby causing the adapter plate 3 to deflect. The movement of the adapter plate 3 will then be transmitted to the universal adjustable connecting rod 4, ensuring that the two universal adjustable connecting rods 4 always remain connected to both ends of the dual-outlet steering cylinder 18. When the dual-outlet steering cylinder 18 performs a reverse action, the two passive load power sources and the two load telescopic cylinders 5 will perform a reverse action simultaneously. That is, one passive load power source is responsible for providing load force for the extension action of the dual-outlet steering cylinder 18, while the other passive load power source drives the corresponding load telescopic cylinder 5 to extend.

[0087] There are three structural forms of passive load power sources, as detailed below:

[0088] The first structure is shown in the appendix. Figure 6 As shown, the assembly includes an adjusting rod 8, a limiting plate 7, and a spring 6. The adjusting rod 8 is rotatably connected to the end of the cylinder 5-1 opposite to the protruding end of the piston rod 5-3, and its end extending into the piston cavity is threadedly connected to the limiting plate 7. A sliding key 9 is fixedly connected to one side of the limiting plate 7, forming a sliding connection with the piston cavity to restrict the rotation of the limiting plate 7. The spring 6 is installed in the piston cavity between the limiting plate 7 and the piston 5-2.

[0089] By turning the adjusting rod 8, the position of the limiting plate 7 on the adjusting rod 8 can be adjusted, thereby changing the compression of the spring 6 and realizing the adjustment of the maximum load force of the passive load power source. This passive load power source can provide a linearly increasing load force for the dual-output steering cylinder 18 and supports the adjustment of the magnitude of the maximum load force.

[0090] In addition, as attached Figure 6As shown, piston 5-2 is designed with a through hole allowing adjusting rod 8 to pass through, and piston rod 5-3 adopts a hollow tubular structure, allowing adjusting rod 8 to extend into the cavity of piston rod 5-3. This design effectively expands the stroke range of piston 5-2 and piston rod 5-3 without increasing the size of cylinder 5-1, making it adaptable to dual-output steering cylinders 18 with different stroke requirements, significantly improving versatility and practicality.

[0091] The structure of the second type of passive load power source is shown in the attached figure. Figure 7 As shown, it mainly consists of an oil tank 10 and an overflow valve 11. The oil tank 10 is used to store hydraulic oil and is connected to the piston chamber of cylinder 5-1 through an inlet pipe and an outlet pipe. Both the inlet and outlet pipes are equipped with check valves to ensure that hydraulic oil can only be input into the piston chamber through the inlet pipe, pushing the piston 5-2 and causing the piston rod 5-3 to push outward. When the piston rod 5-3 performs the reverse action, it will squeeze out the hydraulic oil in the piston chamber. The squeezed hydraulic oil flows back to the oil tank 10 through the outlet pipe. At the same time, the hydraulic oil in the oil tank 10 will be squeezed into the piston chamber of another cylinder 5-1, causing the other load telescopic cylinder 5 to extend.

[0092] Relief valves 11 are installed on the oil outlet pipes of both cylinders 5-1. When the dual-outlet steering cylinder 18 extends in a certain direction, the corresponding adapter plate 3 pushes the piston rod 5-3 back into the cylinder 5-1, squeezing out the hydraulic oil inside the cylinder 5-1 and passing through the relief valves 11 during the flow. The piston rod 5-3 will only continue to move when the hydraulic oil pressure reaches the opening pressure of the relief valve 11. At this time, the opening pressure of the relief valve 11 corresponds to the load force borne by the dual-outlet steering cylinder 18. By adjusting the opening pressure of the relief valve 11, the load force of the passive load power source can be adjusted. This passive load power source can provide a constant load force for the dual-outlet steering cylinder 18.

[0093] The third type of passive load power source is an improvement on the second structure, primarily optimizing the durability of the piston 5-2 and piston cavity sealing performance in the second structure. During the durability test, frequent friction between the piston 5-2 and piston cavity may cause the piston 5-2 to wear out before the test is completed, thus interrupting the test process. The third structure introduces a hydraulic elastic bladder 12 and a two-way relief valve 13. Specifically, two hydraulic elastic bladders 12 are respectively installed inside the piston cavities of the two cylinders 5-1 and are interconnected by pipelines. A two-way relief valve 13 is installed on the pipeline between the two hydraulic elastic bladders 12. By adjusting the pressure of the two-way relief valve 13, the load force of the passive load power source can be adjusted. During the durability test, when one hydraulic elastic bladder 12 is compressed, the hydraulic oil inside it flows into the other hydraulic elastic bladder 12 through the pipeline and the two-way relief valve 13, causing the latter to expand. Similar to the working mechanism of the second type of passive load power source structure, the opening pressure of the bidirectional relief valve 13 is the load force borne by the dual-outlet steering cylinder 18. The design service life of the hydraulic elastic balloon 12 far exceeds the service life of the upper sealing ring of the piston 5-2. Actual testing has verified that the hydraulic elastic balloon 12 can withstand approximately 8 million reciprocating expansion and contraction cycles, which fully meets the durability test requirements of the dual-outlet steering cylinder 18.

[0094] The testing procedure for the hydraulic cylinder testing device involved in this embodiment, specifically for the dual-output steering cylinder 18, is as follows:

[0095] Step S1: Mounting and Connection. Use the quick-release locking device 2 to fix the double-outlet steering cylinder 18 onto the mounting bracket 1, and connect the inlet and outlet oil connectors of the double-outlet steering cylinder 18 to the hydraulic station 16 via hydraulic oil pipes. This step ensures the double-outlet steering cylinder 18 is securely fixed and facilitates subsequent connection operations with the hydraulic station 16.

[0096] Step S2: Static Pressure Test. Start the hydraulic station 16 and inject hydraulic oil into the piston chamber of the dual-outlet steering cylinder 18. Set the injection pressure to greater than 35 MPa. Keep it stationary for 5 to 10 minutes and carefully check both ends of the dual-outlet steering cylinder 18 for any oil leakage. It is worth noting that the dual-outlet steering cylinder 18 must undergo a static pressure test before leaving the factory to verify its sealing performance, identify potential quality defects, and ensure product quality.

[0097] Step S3: Durability Test. Connect both ends of the dual-outlet steering cylinder 18 to two load simulation mechanisms, and control the reciprocating motion of the cylinder using solenoid valves. During the reciprocating motion of the cylinder 18, the two load simulation mechanisms apply load forces coaxial with the cylinder 18's axis to both ends, simulating actual working conditions. Since durability testing typically requires the cylinder 18 to perform 500,000 reciprocating extension / retraction cycles, which is time-consuming, durability testing is generally only performed on the first prototype or for random sampling.

[0098] There are two load simulation scenarios: First, the two universal adjustable connecting rods 4 are connected to the same mounting holes on the two adapter plates 3, ensuring that both ends of the dual-output steering cylinder 18 are subjected to the same load conditions. Second, the two universal adjustable connecting rods 4 are connected to mounting holes on the two adapter plates 3 at different locations, resulting in different load conditions at both ends of the dual-output steering cylinder 18. During the durability test, these two load simulation scenarios are performed alternately to obtain more comprehensive and accurate test data.

[0099] Example 2:

[0100] Combined with appendix Figure 1 and 4 This invention relates to a hydraulic cylinder testing device and method, which is an improvement upon Embodiment 1. Specifically, the structure of the universal adjustable connecting rod 4 is refined, comprising a universal ball joint connector 4-1, a connecting pipe 4-2, and a connecting rod 4-3. A groove is designed at the ball joint portion of the universal ball joint connector 4-1, away from the ball head. In actual use, the end of the dual-outlet steering cylinder 18 can be inserted into the groove of the universal ball joint connector 4-1, thereby achieving effective connection between the dual-outlet steering cylinder 18 and the universal ball joint connector 4-1. Furthermore, the universal ball joint connector 4-1 effectively avoids jamming problems that may occur due to the dual-outlet steering cylinder 18 and the adapter plate 3 not being on the same plane, which plays a crucial role in the normal operation of the hydraulic cylinder testing device and the smooth conduct of the test.

[0101] The connecting tube 4-2 and the ball joint of the universal ball joint connector 4-1 are tightly connected. A connecting rod 4-3 is inserted inside the connecting tube 4-2, and the connecting rod 4-3 is threadedly connected to the connecting tube 4-2. This threaded connection design allows the extension length of the connecting rod 4-3 to be adjusted by screwing the connecting tube 4-2. When the extension length of the connecting rod 4-3 changes, the length of the entire universal adjustable connecting rod 4 is adjusted accordingly. This length adjustment function enables the dual-outlet steering cylinder 18 to be effectively connected to the corresponding adapter plate 3, meeting the connection requirements of different specifications of dual-outlet steering cylinders 18 under testing scenarios, and ensuring the stability and reliability of the testing device.

[0102] A hinge seat 4-4 is also installed at the extended end of the connecting rod 4-3. This hinge seat 4-4 is hinged to the corresponding adapter plate 3 via a pin. This hinge method further enhances the connection flexibility and stability between the universal adjustable connecting rod 4 and the adapter plate 3, enabling the hydraulic cylinder testing device to better adapt to various complex working conditions during testing, and improving the accuracy and efficiency of the test.

[0103] Example 3:

[0104] Combined with appendix Figures 1-3 9 and 10, a hydraulic cylinder testing device and testing method, based on embodiment one or two, are used to test the quick-release locking device 2, the specific structure of which is as follows:

[0105] The quick-release locking device 2 includes a fixed base 2-1, two sliders 2-2, and a positioning pin 2-3. The fixed base 2-1 is securely connected to the fixed frame 1 via fasteners, ensuring the stability of the entire device during testing. The fixed base 2-1 has an internal mounting cavity, and sliding grooves are provided on both sides corresponding to this cavity. The two sliders 2-2 slide in engagement with these two sliding grooves, meaning that the two sliders 2-2 can retract or extend into the corresponding grooves as needed, thereby realizing the mounting and releasing actions of the dual-output steering cylinder 18.

[0106] A locating pin 2-3 is installed on one side of the slider 2-2. When the double-outlet steering cylinder 18 is installed, the locating pin 2-3 will accurately pass into the mounting hole of the double-outlet steering cylinder 18, thereby achieving precise positioning of the double-outlet steering cylinder 18. (See attached image) Figure 3 , 9 As shown in Figure 10, the number of locating pins 2-3 and the spacing between two adjacent locating pins 2-3 must correspond to the number and spacing of the mounting holes of the double-outlet steering cylinder 18. This ensures that the locating pins 2-3 can be accurately inserted into the corresponding mounting holes, providing an accurate reference for subsequent mounting and testing.

[0107] A bidirectional screw 2-4 is also installed inside the mounting cavity of the fixed base 2-1. The bidirectional screw 2-4 is connected to the fixed base 2-1 by a rotatable connection, and its forward and reverse threaded sections are respectively threaded with threaded sleeves 2-5. That is to say, by turning the bidirectional screw 2-4, the two threaded sleeves 2-5 can be driven to move closer or further apart simultaneously. See attached... Figure 9 As shown, a handle is installed at one end of the bidirectional screw 2-4 that extends out of the fixed base 2-1. This design allows the operator to easily screw the bidirectional screw 2-4, thereby achieving quick adjustment of the position of the screw sleeve 2-5.

[0108] A connecting rod 2-6 is provided between the threaded sleeve 2-5 and the two sliders 2-2. One end of the connecting rod 2-6 is hinged to the slider 2-2, and the other end is hinged to the threaded sleeve 2-5. (See attached...) Figure 9 As shown, there are four connecting rods 2-6, and these four connecting rods 2-6 are arranged in a corresponding and cross configuration. When the two threaded sleeves 2-5 move away from each other, they drive the two sliders 2-2 to retract into the groove, thereby unlocking the cylinder and allowing the double-outlet steering cylinder 18 to be easily removed. When the two threaded sleeves 2-5 move closer to each other, they drive the two sliders 2-2 to push out of the groove, and the sliders 2-2 can abut against the mounting bracket of the double-outlet steering cylinder 18, thus firmly locking the double-outlet steering cylinder 18 and ensuring that the cylinder will not shift or loosen during testing.

[0109] Furthermore, the front side of the fixed base 2-1 is provided with a dovetail-shaped groove, within which a support 2-7 for supporting and limiting the position of the dual-outlet steering cylinder 18 is slidably connected. A locking bolt 2-8 for locking the support 2-7 is threaded onto the support 2-7, and the locking bolt 2-8 can abut against the dovetail-shaped groove. This design allows for flexible adjustment according to different specifications of the dual-outlet steering cylinder 18. Specifically, the operation is as follows: loosen the locking bolt 2-8, and then adjust the height of the support 2-7 according to the size and position requirements of the dual-outlet steering cylinder 18, so that it can better support the cylinder and align its mounting hole with the positioning pin 2-3. After adjustment, tighten the locking bolt 2-8 to lock the position of the support 2-7. In this way, the mounting holes of the double-outlet steering cylinder 18 can be quickly aligned with the locating pins 2-3. Especially when performing batch static pressure tests, only one adjustment is needed to quickly mount multiple double-outlet steering cylinders 18, thereby further shortening the mounting time of the double-outlet steering cylinder 18 and significantly improving the testing efficiency of static pressure tests. This provides an efficient and reliable testing device and method for the production and testing of hydraulic cylinders.

[0110] Example 4:

[0111] Combined with appendix Figure 11A hydraulic cylinder testing device and method are disclosed, which optimizes the oil leakage collection system based on any one of the embodiments in Examples 1 to 3. Oil leakage may occur in the dual-outlet steering cylinder 18 during both static pressure testing and durability testing. A rectangular oil collection box 14 is installed at the bottom of the mounting bracket 1. Its open design effectively covers the oil collection area of ​​the cylinder, accurately collecting leaked oil. The oil collection box 14 is stably placed on the workbench 15, which not only supports the entire hydraulic cylinder testing device but also provides fixed space for the hydraulic station 16. The hydraulic station 16 is embedded in the workbench 15 and is responsible for providing the power required for static and durability testing of the dual-outlet steering cylinder 18. The oil collection box 14 is connected to the oil storage tank 17 through a pipe, ensuring smooth hydraulic oil flow and centralized processing. This design avoids hydraulic oil contamination of the testing environment, saves resources, and improves the environmental friendliness and economy of the hydraulic cylinder testing device.

[0112] The parts of this invention not described in detail are prior art. It will be apparent to those skilled in the art that this invention is not limited to the details of the above exemplary embodiments, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and are intended to encompass all changes falling within the meaning and scope of equivalents within this invention.

Claims

1. A test method for a hydraulic cylinder test device for testing the durability of a double-out steering cylinder (18), characterized by, The hydraulic cylinder testing device includes: Fixture (1); The quick-release locking device (2) is fastened to one side of the fixed frame (1); it is used to quickly mount the double-outlet steering cylinder (18) onto the fixed frame (1); Two load simulation mechanisms are installed on both sides of the fixed frame (1); used to provide load forces at both ends of the double-outlet steering cylinder (18) that are not on the same axis as the double-outlet steering cylinder (18); The load simulation mechanism includes: The adapter plate (3) is hinged to the fixing frame (1); one end of the adapter plate (3) is provided with a pin hole, and the other end is provided with multiple mounting holes at intervals; the adapter plate (3) has an arc-shaped structure. The universal adjustable connecting rod (4) has one end universally connected to one end of the double-outlet steering cylinder (18); the other end is hinged to one of the mounting holes of the adapter plate (3). The load telescopic cylinder (5) has one end hinged to the fixed frame (1) and the other end hinged to the pin hole of the adapter plate (3). The passive load power source, in conjunction with the load telescopic cylinder (5), provides load force to the dual-outlet steering cylinder (18); the passive load power source does not require external power input; The load-bearing telescopic cylinder (5) includes: The cylinder body (5-1) has a piston chamber inside; Piston (5-2) is slidably connected inside cylinder (5-1); The piston rod (5-3) has one end connected to the piston (5-2) and the other end extends out of the cylinder (5-1). The passive load power source includes: Two hydraulic elastic balloons (12) are respectively located in the piston chambers of two cylinders (5-1); the two hydraulic elastic balloons (12) are connected by corresponding pipelines; A two-way relief valve (13) is installed on the pipeline between two hydraulic elastic balloons (12); the load force of the passive load power source is adjusted by adjusting the pressure of the two-way relief valve (13); The universal adjustable connecting rod (4) includes: The universal ball joint connector (4-1) has a groove at the end of the ball joint away from the ball head; Connecting tube (4-2) is fastened to the corresponding ball head; The connecting rod (4-3) is inserted into the connecting tube (4-2) and threadedly connected to the connecting tube (4-2); The hinge seat (4-4) is installed at the extended end of the connecting rod (4-3); The testing method includes the following steps: S1. Mounting and connecting: The double-outlet steering cylinder (18) is mounted on the fixed frame (1) by the quick-release locking device (2); the inlet and outlet oil connectors of the double-outlet steering cylinder (18) are connected to the hydraulic station (16) by the hydraulic oil pipe. S2. Static pressure test: Start the hydraulic station (16) and inject hydraulic oil into the piston chamber of the double-outlet steering cylinder (18). The injection pressure is greater than 35MPa. Let it stand for 5 to 10 minutes and check whether there is any oil leakage at both ends of the double-outlet steering cylinder (18). S3. Durability test: Connect the two ends of the double-outlet steering cylinder (18) to two load simulation mechanisms respectively; control the reciprocating motion of the double-outlet steering cylinder (18) through the solenoid valve. During the reciprocating motion of the double-outlet steering cylinder (18), the two load simulation mechanisms provide load forces on the two ends of the double-outlet steering cylinder (18) that are different from the axis of the double-outlet steering cylinder (18) to simulate the actual working conditions. Load simulation is divided into two cases; The first method: Two universal adjustable connecting rods (4) are respectively connected to the mounting holes at the same position of the two adapter plates (3); so that the load conditions at both ends of the double-outlet steering cylinder (18) are the same; The second type: Two universal adjustable connecting rods (4) are respectively connected to the mounting holes at different positions of the two adapter plates (3); so that the load conditions at both ends of the double-outlet steering cylinder (18) are different; Two load simulation conditions were performed alternately.

2. The hydraulic cylinder testing apparatus testing method of claim 1, wherein, The quick-release locking device (2) includes: The fixed base (2-1) is fastened to the fixed frame (1); the fixed base (2-1) is provided with an installation cavity, and the two sides corresponding to the installation cavity are provided with sliding grooves; Two sliders (2-2) are respectively engaged with two sliding grooves; The positioning pin (2-3) is installed on one side of the slider (2-2); when installing the double-outlet steering cylinder (18), the positioning pin (2-3) is inserted into the mounting hole of the double-outlet steering cylinder (18); The bidirectional screw (2-4) is installed in the mounting cavity of the fixed base (2-1) and is rotatably connected to the fixed base (2-1); Two threaded sleeves (2-5) are threadedly connected to the positive and negative threaded sections of the double-acting screw (2-4), respectively; by turning the double-acting screw (2-4), the two threaded sleeves (2-5) are synchronously driven to move closer or further apart from each other; The connecting rod (2-6) is hinged at one end to the slider (2-2) and at the other end to the threaded sleeve (2-5); when the two threaded sleeves (2-5) move away from each other, they drive the two sliders (2-2) to retract into the groove; when the two threaded sleeves (2-5) move closer to each other, they drive the two sliders (2-2) to push out of the groove, and the sliders (2-2) can correspond to and abut against the mounting bracket of the double-outlet steering cylinder (18).

3. The method of testing a hydraulic cylinder testing apparatus of claim 2, wherein, The front side of the fixed seat (2-1) is provided with a dovetail-shaped groove, and a support (2-7) for supporting and limiting the double-outlet steering cylinder (18) is slidably connected in the dovetail-shaped groove. A locking bolt (2-8) for locking the support (2-7) is threaded on the support (2-7).

4. The method of testing a hydraulic cylinder testing apparatus according to any one of claims 1 to 3, wherein The bottom of the fixed frame (1) is provided with an oil receiving box (14), which is placed on the workbench (15). The workbench (15) is provided with a hydraulic station (16) for providing test power to the double-outlet steering cylinder (18). On one side of the hydraulic station (16) is an oil storage tank (17) that is connected to the oil receiving box (14).

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