Adjustable testing device for fatigue test of cylinder sleeve

Abstract

The invention relates to an adjustable test device for a fatigue test of a cylinder sleeve, which belongs to the technical field of performance test of engine parts and comprises a high-pressure top cover communicated with a pulsating hydraulic system, a high-pressure cavity formed by the high-pressure top cover and a floating piston top, and a hydraulic pulsating load acting on a touch piston skirt through the floating piston top, the position of the hinged connecting rod is changed by adjusting the movable supporting seat, so that the position and the size of the side pressure borne by the cylinder sleeve are adjusted, and the test requirements of specific working conditions in different scenes are met; the actual working conditions that the side wall of the cylinder sleeve bears gas expansion pressure and the piston skirt exerts lateral pressure periodic action on the cylinder sleeve when the engine runs are simulated, and a pressure measuring hole is further formed in the center of the high-pressure top cover and is in electric signal connection with pressure monitoring equipment to monitor the pressure in the cylinder sleeve. The method is beneficial to reliability test researches such as cylinder sleeve fault reproduction and cylinder sleeve multi-scheme structure optimization.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engine parts performance test, which is the cross application of material mechanics test technology and engine engineering technology, and is specially used for simulating and evaluating the fatigue strength and reliability of cylinder liner under actual working conditions. BACKGROUND

[0002] As an important part of engine, the cylinder liner has the functions of combustion chamber composition and piston movement guiding, and has a thin-walled hollow tube structure, is positioned by a stopper, is supported upward and downward, and has a water jacket formed by the suspended middle part. The cylinder liner has powerful functions, large support span, and bears the periodic action of internal high pressure and lateral force in working, has large deformation, and has concentrated stress points, and thus has very high requirements for structural strength and fatigue reliability. Especially, the cylinder liner shoulder and side wall are often cracked due to the influence of various factors such as overload, overspeed and insufficient rigidity. In order to test the structural strength and fatigue reliability of the cylinder liner, calculation simulation and part fatigue test are often used for examination in the engineering design process. The cylinder liner fatigue test is generally divided into two types, one is whole machine loading fatigue test, and the other is mechanical part fatigue test. The whole machine loading fatigue test has the disadvantages of complicated process, high cost, great risk and low efficiency, and has the advantages of real working environment of the cylinder liner, obvious comprehensive action of load, and high reliability. The mechanical part fatigue test uses liquid pressure to simulate the periodic action of gas pressure, has the disadvantages of low test frequency, small temperature influence, single load action, simple test process, convenient assembly, low cost, flexible test sample quantity and scheme, convenient load control, and wide working condition simulation range. The mechanical part fatigue test of the cylinder liner mainly focuses on the double influence of pre-tightening force and cylinder pressure, but the existing mechanical part fatigue test only tests the bearing capacity of the burst pressure, and does not test the influence of pre-tightening force.

[0003] Therefore, it is necessary to develop an adjustable test device suitable for the cylinder liner fatigue test under various working conditions. SUMMARY

[0004] In order to solve the problems in the background art, the present application provides an adjustable test device for cylinder liner fatigue test. The device is designed based on the working load actually borne by the cylinder liner, i.e. pre-tightening force, burst pressure, lateral force and pressure bearing position, and is a part fatigue simulation test device based on hydraulic pulsation environment. The device has the advantages of simple structure, convenient assembly, flexible working condition conversion, accurate load application, reliable internal pressure sealing and stable test process, and is beneficial to the reliability test researches such as cylinder liner fault reproduction and cylinder liner structure optimization.

[0005] To solve the above technical problems, the technical scheme adopted by the present application is: comprising a high-pressure top cover, a boss and an oil inlet hole are arranged at the center of the high-pressure top cover, the boss and a floating piston top form a high-pressure cavity, the oil inlet hole is arranged in communication with a pulsating hydraulic system, and a hydraulic pulsation load is generated; The floating piston top is in contact with a touch piston skirt, the hydraulic pulsation load acts on the touch piston skirt through the floating piston top, the touch piston skirt is periodically pushed to exert a periodically changing lateral force on the cylinder liner sidewall according to a preset proportional relationship, and the actual working condition of the cylinder liner sidewall bearing gas expansion pressure and the piston skirt exerting a periodic lateral pressure on the cylinder liner sidewall during engine operation is simulated. The touch piston skirt is arranged on the upper part of the articulated connecting rod, the articulated connecting rod is fixed on a moving support base to transmit the force, the position of the articulated connecting rod is adjusted through the movement of the moving support base, the load bearing position of the touch piston skirt is changed, and the size of the force is adjusted. The high-pressure top cover is fixedly connected with the support cylinder body through bolts, and a pre-tightening force is generated when the bolts are fastened to simulate the pre-tightening state of the cylinder liner.

[0006] Further, the high-pressure top cover is circular, and at least four bolt holes are arranged on the end face, and the number of the bolt holes is not less than the total number of bolts of a single cylinder block of the engine, the bolt holes are uniformly distributed along the axis, the bolt holes are matched with threaded holes on the support cylinder body, and the high-pressure top cover is fixedly connected with the support cylinder body through the bolts.

[0007] Further, the high-pressure top cover is further provided with a pressure measuring hole, a pressure sensor is arranged in the pressure measuring hole, and the sensor is electrically connected with a pressure monitoring device.

[0008] Further, a cylinder gasket is arranged between the high-pressure top cover and the cylinder liner protruding edge to axially seal the high-pressure cavity.

[0009] Further, the support cylinder body comprises a cylinder liner protruding edge support counterbore, upper and lower water jacket support holes and an open articulated mechanism chamber, the cylinder liner protruding edge support counterbore and the upper and lower water jacket support holes are arranged according to the basic structure of the cylinder hole in which the cylinder liner is arranged in the state of the whole machine, the open articulated mechanism chamber is arranged at the lower part of the support cylinder body, the left and right sides of the open articulated mechanism chamber are provided with through adjustment windows, the bottom of the support cylinder body is provided with a flange plate structure, at least four bolt holes are arranged on the flange plate structure, and the bolt holes are matched with connecting bolts.

[0010] Further, the touch piston skirt is made of the material of the original machine, and is arranged according to the specific structure and circumferential contour line of the piston skirt of the original machine, the touch piston skirt comprises a piston pin hole and a piston pin clamping groove, the piston pin hole is matched with the piston pin of the original machine, and the piston pin clamping groove is matched with the snap ring of the original machine.

[0011] Further, a sealing ring is arranged between the floating piston top and the cylinder liner to radially seal the high-pressure cavity.

[0012] Further, the articulated connecting rod adopts a double-hole whole-circle integrated structure, the upper part of which is matched with the piston pin, and the lower part is matched with the support pin.

[0013] Further, the moving support base is a double-support whole-base structure, the double-support holes of which are matched with the support pins in the axial direction, and the moving support base is provided with open long through holes on the front and rear sides.

[0014] Further, the machine base is a disc structure, and the end face is provided with at least four bolt holes matched with the bottom flange disc structure of the support cylinder body, which are uniformly distributed along the axis of the machine base, the middle of the machine base is provided with a rectangular counterbore, the bottom of the rectangular counterbore is provided with at least four bolt holes, the front and rear sidewalls of the rectangular counterbore are each provided with one bolt hole, the upper surface of the machine base is provided with a circular-arc-shaped positioning boss, and the positioning bosses are symmetrically arranged.

[0015] Compared with the prior art, the present application has the following advantages and beneficial effects.

[0016] 1. The present application is a component fatigue simulation test device based on a hydraulic pulsation environment, which is designed according to the actual working load of the cylinder liner, i.e. the pre-tightening force, the expansion force, the lateral force and the pressure-bearing position, has the advantages of simple structure, convenient assembly, flexible working condition conversion, accurate load application, reliable internal pressure sealing and stable test process, and is beneficial to the reliability test research of cylinder liner fault reproduction and cylinder liner multi-scheme structure optimization.

[0017] 2. The present application is arranged based on the actual assembly requirements of the cylinder liner, and the upper and lower supports of the cylinder liner and the sealing of the water jacket are the same as those of the original machine, so that the support is reasonable, the assembly is standard, the stress is consistent, and the component working state simulation degree is high.

[0018] 3. The high-pressure head cover bolts of the present application are uniformly distributed along the axis, the cylinder liner generates a pre-deformation under the action of the pre-tightening force, the cylinder gasket bears pressure uniformly, the high-pressure cavity is tightly sealed, and the hydraulic pulsation action is stable.

[0019] 4. The floating piston top of the present application is in contact with the end surface of the touch piston skirt, and can effectively transmit the force by cooperating with the moving support base design, so as to ensure the accuracy of the cylinder liner pressure and the action area, has strong load linkage, controllable force size and controllable bearing position.

[0020] 5. The floating piston top and the touch piston skirt of the present application are designed separately, which not only meets the modification of the finished piston structure, but also can design the piston skirt of multiple schemes, greatly meets the adaptability research of the cylinder liner to different piston skirt structures, and has high utilization rate and strong universality.

[0021] 6. The application is suitable for cylinder liner fatigue test under various working conditions, can flexibly adjust various working condition requirements of the cylinder liner, such as cylinder expansion force, lateral force, lateral force bearing position and area, and quickly convert, and reliably fatigue test the cylinder liner. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the application, and are incorporated herein for explanatory purposes. The following description and drawings are used to explain the application, and do not constitute an improper limitation to the application. In the drawings: Figure 1 The structure diagram of the adjustable test device for cylinder liner fatigue test described in the application.

[0023] Explanation of reference signs: 1. High pressure head; 2. Cylinder gasket; 3. Support cylinder; 4. Sealing ring; 5. Floating piston top; 6. Touching piston skirt; 7. Piston pin; 8. Hinged connecting rod; 9. Support pin; 10. Machine base; 11. Moving support base; 12. Stud adjuster; 13. Connecting bolt; 14. Fixed bolt; 15. Cylinder liner; 151. Cylinder liner protrusion; 16. Oil inlet hole; 17. Pressure measuring hole; 18. High pressure cavity; 19. Side pressure acting area; 20. Adjustment window; 21. Pulsating hydraulic system; 22. Pressure monitoring equipment; 31. Second bolt; 24. Clasp; 101. Rectangular counterbore; 102. Open long hole; 103. Second bolt hole; 104. Third bolt hole; 105. Threaded hole; 106. Boss; 107. Fourth bolt hole; 111. Double support hole; 201. First bolt hole; 303. Protrusion support counterbore; 304. Upper and lower water jacket support hole; 302. Open hinged mechanism chamber; 301. Base hole; 501. Sealing groove; 601. Piston pin hole; 602. Piston pin clamping groove. DETAILED DESCRIPTION

[0024] It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other without conflict.

[0025] In the description of the present application, it needs to be understood that the technical terms "center", "middle", "convex", "lateral", "upper", "lower", "left", "right", "through", "upper", "lower", "bottom", "short", "circumferential", "axial", "radial", "front and back" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. The "first", "second" and similar words used in the embodiments of the present application do not represent any order, quantity or importance, but are only used to distinguish different components.

[0026] The terms "include" or "contain" and the like mean that the elements appearing before the word cover the elements listed after the word and their equivalents, without excluding other elements. The terms "connect", "communicate" or "fix" and the like are not limited to a single connection or fixation method, but can include various connection or fixation methods such as screw fastening, screw connection, welding, etc.

[0027] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0028] The adjustable test device for cylinder liner fatigue test comprises a high-pressure head 1, a cylinder gasket 2, a support cylinder 3, a sealing ring 4, a floating piston top 5, a touch piston skirt 6, a piston pin 7, a hinged connecting rod 8, a support pin 9, a machine base 10, a movable support base 11, a stud adjuster 12, a first bolt 13, a fixing bolt 14, a cylinder liner 15, a cylinder liner convex edge 151, an oil inlet hole 16, a pressure measuring hole 17, a high-pressure cavity 18, a side pressure acting area 19, an adjustment window 20, a pulsating hydraulic system 21, a pressure monitoring device 22, a snap ring 24, a second bolt 31, a rectangular counterbore 101, an open long through hole 102, a second bolt hole 103, a third bolt hole 104, a threaded hole 105, a boss 106, a fourth bolt hole 107, a double support hole 111, a first bolt hole 201, a support counterbore 303, an upper and lower water jacket support hole 304, an open hinge mechanism chamber 302, a base hole 301, a sealing groove 501, a piston pin hole 601 and a piston pin snap groove 602.

[0029] First, the movable support base 11 is fixedly connected with the machine base 10 through the fixing bolt 14, then the hinged connecting rod 8 is connected with the movable support base 11 through the support pin 9, the hinged connecting rod 8 is connected with the touch piston skirt 6 through the piston pin 7, and the touch piston skirt 6 is in contact with the end surface of the floating piston top 5; The support cylinder 3 is fixedly connected with the base 10 through the second bolt 31, the cylinder sleeve 15 is installed in the support cylinder 3, and the inner wall of the cylinder sleeve 15 is matched with the outer circle of the floating piston top 5 and the triggering piston skirt 6, and the sealing ring 4 is installed between the cylinder sleeve 15 and the floating piston top 5; The cylinder gasket 2 is installed between the cylinder sleeve convex edge 151 and the high-pressure top cover 1, and the support cylinder 3 and the high-pressure top cover 1 are fixedly connected through the first bolt 13. The oil inlet hole 16 is arranged in communication with the pulsating hydraulic system 21, and the pressure measuring hole 17 is in electrical signal communication with the pressure monitoring device 22.

[0030] Preferably, the high-pressure top cover 1 is circular, and at least four first bolt holes 201 are arranged on the end face of the high-pressure top cover 1 and are uniformly distributed along the axis, so that when the cylinder sleeve 15 is pre-deformed under the action of the pre-tightening force, the cylinder gasket 2 is uniformly pressed, the high-pressure cavity 18 is tightly sealed, and the hydraulic pulsation is stable.

[0031] Preferably, the high-pressure top cover 1 is circular, and at least four first bolt holes 201 are arranged on the end face of the high-pressure top cover 1 and are uniformly distributed along the axis, so that when the cylinder sleeve 15 is pre-deformed under the action of the pre-tightening force, the cylinder gasket 2 is uniformly pressed, the high-pressure cavity 18 is tightly sealed, and the hydraulic pulsation is stable.

[0032] Preferably, the support cylinder 3 includes a cylinder sleeve convex edge support counterbore 303, upper and lower water jacket support holes 304, and an open hinge mechanism chamber 302, the cylinder sleeve convex edge support counterbore 303 and the upper and lower water jacket support holes 304 are arranged according to the basic structure of the cylinder hole in which the cylinder sleeve is located in the state of the whole machine, so that the actual working state of the cylinder sleeve 15 can be highly restored, the open hinge mechanism chamber 302 is arranged at the lower part of the support cylinder 3, and the left and right sides of the open hinge mechanism chamber 302 are provided with through adjustment windows 20, so that the relative position of the support seat 11 can be conveniently adjusted, and the lateral force generated by the triggering piston skirt 6 can be applied to the lateral pressure action area 19 of the side wall of the cylinder sleeve 15.

[0033] Preferably, the triggering piston skirt 6 is made of the original machine material and is designed according to the specific structure and circumferential contour of the original machine piston skirt, the triggering piston skirt 6 includes a piston pin hole 601 and a piston pin clamping groove 602, the piston pin hole 601 is matched with the piston pin 7 of the original machine, and the piston pin clamping groove 602 is matched with the snap ring 24 of the original machine, so that the working state of the original machine piston can be highly restored.

[0034] Preferably, a radial sealing groove 501 is machined on the outer circle of the floating piston top 5, and the sealing ring 4 is assembled, so as to ensure the pressure sealing of the high-pressure cavity 18 and the safety and reliability during the up and down slight movement, the floating piston top 5 and the top part of the triggering piston skirt 6 can relatively slightly slide without interfering with each other in the force transmission process, the sealing reliability during long-time fatigue test is ensured, and the lateral load is accurately and effectively applied to the lateral pressure action area 19 of the side wall of the cylinder sleeve 15.

[0035] Preferably, the articulated connecting rod 8 adopts a double-hole whole-circle integrated structure, which is matched with the piston pin 7 and the support pin 9 respectively to realize the articulated rotating function, and the rectangular rod section structure has high structural strength and rigidity to ensure that the cylinder liner 15 bears stable lateral force.

[0036] Preferably, the movable support base 11 is a double-support and base integrated structure, the double-support holes 111 of which are matched with the support pin 9 to serve as the swing axis of the articulated connecting rod 8 and the axial displacement limiting function, the movable support base 11 is placed in the rectangular counterbore 101 in the middle of the base 10, is adjusted and positioned in two directions by the stud adjuster 12, and is connected and fixed by the fixed bolt 14, the fixed bolt 14 is distributed in the open long through hole 102 on the front and rear sidewalls of the movable support base 11, and the movable support base 11 is fastened and connected with the base 10 after being adjusted to the final position.

[0037] Preferably, the base 10 is a disc structure, at least four second bolt holes 103 are arranged on the circumference of the base 10, the second bolt holes 103 are matched with the bottom flange structure of the support cylinder body 3, are uniformly distributed along the axis of the base 10, the rectangular counterbore 101 is arranged in the middle of the base 10, at least four third bolt holes 104 are arranged at the bottom of the rectangular counterbore 101, at least one threaded hole 105 is arranged on the front and rear sidewalls of the rectangular counterbore 101, the rectangular counterbore 101 and the third bolt holes 104 at the bottom are used for installing the movable support base 11, the arc-shaped positioning bosses 106 are symmetrically arranged on the planes on the two long sides of the rectangular counterbore 101, the bosses 106 are matched with the base hole 301 of the support cylinder body 3 to serve as the overall positioning function of the test bench, the threaded holes 105 are arranged on the two short sides of the rectangular counterbore 101 for installing the stud adjuster 12, the stud adjuster 12 drives the movable support base 11 to move freely through the threaded holes 105, changes the inclination angle β of the articulated connecting rod 8, adjusts the size and position of the lateral force borne by the cylinder liner 15, and realizes the position adjustment purpose, if it is desired to keep the original position unchanged, the original position can be kept unchanged by replacing the piston skirt.

[0038] Preferably, the floating piston top 5 and the touching piston skirt 6 adopt surface contact, and in the test, they are relatively free to slide in different directions, eliminating the structural influence in the process of pressure transmission in the cylinder.

[0039] Preferably, the test device uses an electro-hydraulic servo system to simulate the pressure in the cylinder.

[0040] The adjustable test device for the cylinder liner fatigue test is as follows: 1) The design of high-pressure head 1: high-pressure head 1 is a disc with a raised middle part, with bolt through holes distributed around the periphery, an oil inlet hole 16 and a pressure measuring hole 17 in the middle, and the raised middle part combined with the cylinder liner 15 to form a high-pressure cavity 18, effectively reducing the internal space of the high-pressure cavity 18, which is conducive to the stable operation of the high-pressure pulsating load, and the cylinder gasket 2 can maintain the reliable sealing of the high-pressure cavity 18 under the tightening action of the first bolt 13. In addition, the cylinder liner flange 151 deforms under the action of the pre-tightening force, which can simulate the pre-tightening state of the cylinder liner under actual conditions; The oil inlet hole 16 is connected with the pulsating hydraulic system 21, and the pressure in the high-pressure cavity 18 is monitored through the pressure measuring hole 17.

[0041] 2) The design of the support cylinder body 3: the support cylinder body 3 is the main structure of the test device, which is opened according to the basic structure of the cylinder hole where the cylinder liner is located under the condition of the whole machine, including cylinder liner flange 151 support counterbore 303, upper and lower water jacket support hole 304, etc. The structure size needs to be designed strictly according to the support position and form of the cylinder liner under actual working condition; The lower part of the support cylinder body 3 is an open type hinge mechanism chamber 302, which is combined with the base 10. Four second bolt holes 103 are machined on the bottom flange of the support cylinder body 3, matched with the connecting bolt 13, and connected in the form of flange structure by the connecting bolt 13; The open type hinge mechanism chamber 302 at the lower part of the support cylinder body 3 is machined with left and right through adjustment window 20, which is convenient for adjusting the relative position of the movable support seat 11, realizing the side pressure action area 19 on the side wall of the cylinder liner 15 by the side force generated by the touch piston skirt 6.

[0042] 3) The design of the touch piston skirt 6 and the floating piston top 5: the touch piston skirt 6 refers to the piston skirt structure that applies lateral force to the side wall of the cylinder liner 15, which is combined with the floating piston top 5 to become a complete piston structure; The specific structure of the touch piston skirt 6 can be modified from the original machine piston group, or it can be redesigned according to the requirements. Among them, the touch piston skirt 6 should use the original machine material and be designed according to the specific structure and circumferential contour of the piston group; The touch piston skirt 6 is machined with piston pin hole 601 and piston pin clamping groove 602 for installing the original machine piston pin 7 and the snap ring 24; The top of the touch piston skirt 6 is in contact with the end face of the floating piston top 5. The pulsating load generated in the high-pressure cavity 18 acts on the touch piston skirt 6 through the floating piston top 5, which makes the cylinder liner 15 bear the expansion force in the cylinder on one hand, and the touch piston skirt 6 generates alternating lateral force on the side wall of the cylinder liner 15 in a certain proportion on the other hand; The floating piston top 5 has two functions, one is to ensure the sealing of the high-pressure cavity 18, and the other is to transmit the test load; The floating piston top 5 is processed with a radial sealing groove 501, and a polyurethane sealing ring 4 is assembled to ensure the pressure sealing of the high-pressure cavity 18 and the safety and reliability during the up and down micro-motion; The floating piston top 5 can relatively slide slightly with the top of the actuating piston skirt 6 during the force transmission without interfering with each other, which not only ensures the sealing reliability during long-term fatigue test, but also accurately and effectively applies the side pressure to the side pressure area 19 of the side wall of the cylinder liner 15.

[0043] 4) Design of the articulated connecting rod 8 and the moving support base 11: The articulated connecting rod 8 adopts a double-hole whole-circle integrated structure, which is matched with the piston pin 7 and the support pin 9 to realize the articulated rotating function. The rectangular rod section structure has high structural strength and rigidity, which ensures that the cylinder liner 15 bears stable lateral force; The moving support base 11 is a double-support and base integrated structure, and its double-support holes are matched with the support pin 9 to serve as the swing axis of the articulated connecting rod 8 and the axial movement limiting function; The moving support base 11 is placed in the square counterbore 101 in the middle of the base 10, and is adjusted and positioned in the sliding position by the stud adjuster 12, and is connected and fixed by the fixed bolt 14; There are a total of four fixed bolts 14, which are distributed in the open long through holes 102 on the front and rear sidewalls of the moving support base 11. When the moving support base 11 is adjusted to the final position, it is tightly connected with the base 10.

[0044] 5) Design of the base 10: The base 10 is a disc structure, and four fourth bolt holes 107 are processed on the end face to match the support cylinder body 3. A rectangular counterbore 101 is processed in the middle, and four third bolt holes 104 are processed at the bottom; The base 10 is matched with the flange type base of the support cylinder body 3 and connected by the connecting bolt 13; The rectangular counterbore 101 and the third bolt holes 104 at the bottom are used for connection when the moving support base 11 is installed; Arc-shaped positioning bosses 106 are symmetrically processed on the planes of the two long sides of the rectangular counterbore 101, which are matched with the base hole 301 of the support cylinder body 3 to serve as the overall positioning function of the test bench; A threaded hole 105 is processed on each of the front and rear sidewalls of the rectangular counterbore 101, which is used for the installation of the stud adjuster 12. The stud adjuster 12 drives the moving support base 11 to move freely through the threaded hole 105, so as to achieve the purpose of position adjustment.

[0045] 6) The design of the sealing structure: The closed space of the test device is the high-pressure cavity 18, the upper part of the high-pressure oil cavity 18 is sealed by the contact between the cylinder gasket 2, the high-pressure top cover 1 and the end surface of the cylinder sleeve 15, and the contact load is fastened by the circumferentially distributed connecting bolts 13, and the radial sealing of the lower part of the high-pressure cavity 18 is realized by the polyurethane sealing ring 4 between the floating piston top 5 and the cylinder sleeve 15.

[0046] 7) The simulation and monitoring principle of the in-cylinder pressure: The adjustable test device for the cylinder sleeve fatigue test uses an electro-hydraulic servo system to realize the simulation of the in-cylinder pressure, the hydraulic oil in the high-pressure cavity 18 generates a pulsating load, so that the cylinder sleeve 15 is subjected to the in-cylinder expansion pressure and the lateral force of the side wall at the same time, thereby realizing the cylinder sleeve fatigue test, therefore, the device is processed into the oil hole 16 and the pressure measuring hole 17 at the high-pressure top cover 1, which respectively play the roles of conveying the high-pressure hydraulic oil and monitoring the pressure in the cavity in real time.

[0047] 8) The working mode: The pulsating load generated by the high-pressure cavity 18 is transmitted downward to the upper surface of the trigger piston skirt 6 through the floating piston top 5, the trigger piston skirt 6 is supported by the hinged connecting rod 8 through the piston pin 7, and the downward movement trend is generated by the guiding action of the cylinder sleeve 15, due to the arrangement of the hinged connecting rod 8 at a specific inclination angle β, the force generated by the high-pressure cavity 18 is decomposed into the pressure in the direction of the hinged connecting rod 8, and the lateral force of the trigger piston skirt 6 acting on the cylinder sleeve sample 15, so that the simulation and fatigue test of the actual working stress condition of the cylinder sleeve 15 are realized under the alternating load of the high-pressure cavity 18 and the lateral force; The adjustable test device for the cylinder sleeve fatigue test adjusts the position of the movable support seat 11 through the stud adjuster 12, changes the inclination angle β of the hinged connecting rod 8, and thereby adjusts the size and position of the lateral force borne by the cylinder sleeve sample 15, if it is desired to keep the original position unchanged, then the piston skirt can be replaced to adapt to the requirements of different load conditions; The floating piston top 5 and the trigger piston skirt 6 adopt surface contact, and in the test, they relatively slide in different directions, which eliminates the structural influence in the process of transmitting the in-cylinder pressure.

[0048] The above only describes one embodiment of the present application in detail, but the content described can only be the preferred embodiment of the present application, and cannot be considered as limiting the scope of the implementation of the present application. Any equivalent changes and improvements made within the scope of the present application should still belong to the patent coverage range of the present application.

Claims

1. An adjustable test device for a cylinder liner fatigue test, characterized by: The high-pressure top cover is provided with a boss and an oil inlet hole in the center, the boss forms a high-pressure cavity with a floating piston top, and the oil inlet hole is arranged in communication with a pulsating hydraulic system to generate a hydraulic pulsating load. The floating piston top is in contact with a touch piston skirt, the hydraulic pulsating load is applied to the touch piston skirt through the floating piston top, the cylinder liner side wall bears the in-cylinder expansion force, and the touch piston skirt is periodically pushed to exert a periodically changing lateral force on the cylinder liner side wall according to a preset proportional relationship, thereby simulating the actual working condition of the cylinder liner side wall bearing the gas expansion pressure and the periodic action of the lateral pressure exerted by the piston skirt on the cylinder liner side wall during engine operation. The touch piston skirt is arranged on the upper part of the articulated connecting rod, the articulated connecting rod is fixed on a moving support base to transmit the force, the position of the articulated connecting rod is adjusted by moving the moving support base, the load bearing position of the touch piston skirt is changed, and the size of the force is adjusted. The high-pressure top cover is fixedly connected with the support cylinder body by bolts, and the bolts generate a pre-tightening force when they are fastened, thereby simulating the pre-tightening state of the cylinder liner.

2. The adjustable test device for a cylinder liner fatigue test according to claim 1, characterized by: The high-pressure top cover is circular, and the end face is provided with at least four bolt holes, which are not less than the total number of bolts of a single cylinder block of the engine, the bolt holes are uniformly distributed along the axis, the bolt holes are matched with threaded holes on the support cylinder body, and the high-pressure top cover is fixedly connected with the support cylinder body by the bolts.

3. The adjustable test device for a cylinder liner fatigue test according to claim 1, characterized by: The high-pressure top cover is further provided with a pressure measuring hole, a pressure sensor is arranged in the pressure measuring hole, and the sensor is electrically connected with a pressure monitoring device.

4. The adjustable test device for a cylinder liner fatigue test according to claim 1, characterized by: A cylinder gasket is arranged between the high-pressure top cover and the cylinder liner protruding edge to axially seal the high-pressure cavity.

5. The adjustable test device for a cylinder liner fatigue test according to claim 1, characterized by: The support cylinder body includes a cylinder liner protruding edge support counterbore, upper and lower water jacket support holes, and an open articulated mechanism chamber, the cylinder liner protruding edge support counterbore and the upper and lower water jacket support holes are arranged according to the basic structure of the cylinder hole in which the cylinder liner is arranged in the complete machine state, the open articulated mechanism chamber is arranged at the lower part of the support cylinder body, the left and right sides of the open articulated mechanism chamber are provided with through adjustment windows, the bottom of the support cylinder body is provided with a flange structure, and at least four bolt holes are arranged on the flange structure and matched with connecting bolts.

6. The adjustable test device for a cylinder liner fatigue test according to claim 1, characterized by: The touch piston skirt is made of the original machine material, and is arranged according to the specific structure and circumferential contour line of the original piston skirt, the touch piston skirt includes a piston pin hole and a piston pin clamping groove, the piston pin hole is matched with the piston pin of the original machine, and the piston pin clamping groove is matched with the snap ring of the original machine.

7. The adjustable test device for a cylinder liner fatigue test according to claim 1, characterized by: A sealing ring is arranged between the floating piston top and the cylinder liner to radially seal the high-pressure cavity.

8. The adjustable test device for a cylinder liner fatigue test according to claim 1, characterized by: The articulated connecting rod is an integrated structure with a double-hole whole circle, the upper part is matched with the piston pin, and the lower part is matched with a support pin.

9. The adjustable test device for a cylinder liner fatigue test according to claim 1, characterized by: The moving support base is an integrated structure with double supports and a base, the double support holes are matched with the support pins and axially positioned, and the moving support base is provided with open long through holes on the front and back sides.

10. The adjustable test device for a cylinder liner fatigue test according to claim 1, characterized by: The machine base is a disc structure, the end face is provided with at least four bolt holes, the bolt holes are matched with the bottom flange structure of the support cylinder body and uniformly distributed along the axis of the machine base, a rectangular counterbore is arranged in the middle of the machine base, at least four bolt holes are arranged at the bottom of the rectangular counterbore, one bolt hole is arranged on each of the front and back side walls of the rectangular counterbore, a circular arc positioning boss is arranged on the upper surface of the machine base, and the positioning bosses are symmetrically arranged.

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