A general hydraulic cylinder test device and method

Abstract

The present invention discloses a general hydraulic cylinder test device and method. The general hydraulic cylinder test device includes a test bench, a loading cylinder and a cylinder under test. A guiding groove is provided on the test bench. The cylinder barrel base of the loading cylinder is connected to the test bench, and the front end of its cylinder rod is connected to a first pin shaft passing through the guiding groove. The stroke of the cylinder under test is less than that of the loading cylinder. The cylinder barrel base of the cylinder under test is connected to the test bench, and the front end of its cylinder rod is connected to a second pin shaft passing through the guiding groove. The first pin shaft and the second pin shaft are connected by two oppositely arranged connecting plates. When the cylinder under test extends or retracts, the second pin shaft slides in the guiding groove, and force is transmitted to the loading cylinder through the connecting plates and the first pin shaft. The present invention can be applicable to the loading tests of cylinders under test with different shaft diameters and different strokes.

Description

Technical Field

[0001] The present invention belongs to the field of engineering machinery and equipment, and particularly relates to a general hydraulic cylinder test device and method. Background Art

[0002] The loading test is a common test method in the hydraulic cylinder test process. During the test, a loading cylinder (for load loading during the process) and a cylinder under test are required. Different cylinders under test have different installation dimensions and strokes. Therefore, it is necessary to design fixed brackets with different installation holes and lengths for the test.

[0003] Figure 1 As a common test device in the prior art. During the test, two identical hydraulic cylinders need to be provided, one as the loading cylinder and the other as the cylinder under test. One end of the loading cylinder is fixed to the test bench through a pin shaft, and the other end needs a bearing support to support the cylinder rod to keep the loading cylinder balanced. One end of the cylinder under test is fixed to the test bench through a pin shaft, and the other end is connected to the end of the loading cylinder. The distance between the pin shafts of the two cylinder seats just ensures that one cylinder is fully extended and the other cylinder is fully retracted. It can be seen that the test device in the prior art has the following problems:

[0004] (1) The universality of the existing cylinder installation test is poor. The pin hole diameter of the cylinder seat on the test bench needs to be consistent with the hole diameter of the support on the test bench for installation; the distance between the pin shafts of the two cylinder seats needs to ensure that one cylinder is fully extended and the other cylinder is fully retracted, and the test of cylinders with different strokes cannot be carried out.

[0005] (2) The cylinder rod moves back and forth on the bearing support, which will cause frictional damage to the cylinder rod.

[0006] (3) The bearing support is far from the installation point of the cylinder under test support. When the stroke of the cylinder under test is long and the force is large, it will bend and damage the cylinder. Summary of the Invention

[0007] In view of the above problems, the present invention provides a general hydraulic cylinder test device and method, which can be applicable to the loading test of cylinders under test with different shaft diameters and different strokes.

[0008] In order to achieve the above technical objectives and reach the above technical effects, the present invention is realized through the following technical solutions:

[0009] In a first aspect, the present invention provides a general hydraulic cylinder test device, including:

[0010] A test bench, on which a guide groove is provided;

[0011] A loading cylinder, the cylinder barrel base of which is connected to the test bench, and the front end of its cylinder rod is connected to a first pin shaft passing through the guide groove;

[0012] The test cylinder, the stroke of the test cylinder is less than that of the loading cylinder, the cylinder barrel base of which is connected to the test bench, and the front end of the cylinder rod is connected to the second pin shaft passing through the guide groove, and the first pin shaft and the second pin shaft are connected by two oppositely arranged connecting plates;

[0013] When the test cylinder extends or retracts, the second pin shaft slides in the guide groove, and force is transmitted to the loading cylinder through the connecting plate and the first pin shaft.

[0014] Optionally, the general hydraulic cylinder test device further includes a first reversing valve, a second reversing valve, a safety valve, a proportional overflow valve, a first hydraulic oil source and a second hydraulic oil source;

[0015] The first reversing valve is respectively connected to the rod chamber and the rodless chamber of the loading cylinder, and is also connected to the first hydraulic oil source;

[0016] The proportional overflow valve is arranged between the first hydraulic oil source and the first reversing valve;

[0017] The second reversing valve is respectively connected to the rod chamber and the rodless chamber of the test cylinder, and is also connected to the second hydraulic oil source;

[0018] The safety valve is arranged between the second hydraulic oil source and the second reversing valve.

[0019] Optionally, when conducting an extension test on the test cylinder, the first hydraulic oil source is connected to the rodless chamber of the loading cylinder, and the rod chamber of the loading cylinder is connected to the fuel tank; the second hydraulic oil source is connected to the rodless chamber of the test cylinder, and the rod chamber of the test cylinder is connected to the fuel tank;

[0020] The internal pressure of the rodless chamber of the test oil cylinder is regulated by the proportional overflow valve, and the calculation formula is:

[0021]

[0022] where P3 is the internal pressure of the rodless chamber of the test oil cylinder, A1 is the area of the rodless chamber of the loading cylinder, A3 is the area of the rodless chamber of the test cylinder, and P 加 is the loading pressure generated by the proportional overflow valve;

[0023] When the test cylinder is fully extended, since the stroke of the loading cylinder is greater than that of the test cylinder and the loading cylinder is not fully retracted, the internal pressure of the rodless chamber of the test oil cylinder is regulated by the safety valve.

[0024] Optionally, when conducting a retraction test on the test cylinder, the first hydraulic oil source is connected to the rod chamber of the loading cylinder, and the rodless chamber of the loading cylinder is connected to the fuel tank; the second hydraulic oil source is connected to the rod chamber of the test cylinder, and the rodless chamber of the test cylinder is connected to the fuel tank;

[0025] The internal pressure of the rod chamber of the tested oil cylinder is regulated by a proportional overflow valve, and the calculation formula is:

[0026]

[0027] Wherein, P4 is the internal pressure of the rod chamber of the tested oil cylinder, A2 is the rod chamber area of the loading cylinder, A3 is the rod chamber area of the tested cylinder, and P 加 is the loading pressure generated by the proportional overflow valve;

[0028] When the tested cylinder is fully retracted, since the stroke of the loading cylinder is greater than that of the tested cylinder and the loading cylinder is not fully extended, the internal pressure of the rod chamber of the tested oil cylinder is regulated by the safety valve.

[0029] Optionally, the general hydraulic cylinder test device further includes a first protection member and a second protection member which are oppositely arranged, and are respectively fixedly arranged at preset positions on the loading cylinder, with a preset gap between them and the loading cylinder, and are used in cooperation to ensure that the loading cylinder does not deform.

[0030] Optionally, the general hydraulic cylinder test device further includes a third protection member and a fourth protection member which are oppositely arranged, and are respectively movably arranged at preset positions on the tested cylinder, with a preset gap between them and the tested cylinder, and are used in cooperation to ensure that the tested cylinder does not deform.

[0031] Optionally, the test bench is provided with a first protection device guide rail and a second protection device guide rail; a first slider is slidably arranged in the first protection device guide rail; a second slider is slidably arranged in the second protection device guide rail; the third protection member is connected to the first slider through an adjusting member with a thread; the fourth protection member is connected to the second slider through an adjusting member with a thread.

[0032] Optionally, gaskets are arranged on both the first pin shaft and the second pin shaft, and the gaskets are used to fill the gaps between the ends of the loading cylinder and the tested cylinder and the test bench; for tested cylinders of different sizes, a pin shaft sleeve is arranged between the base of the tested cylinder and the second pin shaft, and the inner diameter of the pin shaft sleeve is the same as the outer diameter of the second pin shaft, and its outer diameter is the same as the inner diameter of the base of the tested cylinder.

[0033] In a second aspect, the present invention provides a general hydraulic cylinder test method, including:

[0034] Install the loading cylinder on the test bench, connect the cylinder barrel base of the loading cylinder to the test bench, and connect the front end of its cylinder rod to the first pin shaft passing through the guide groove;

[0035] Install the test cylinder on the test bench. The stroke of the test cylinder is less than that of the loading cylinder. Its cylinder base is connected to the test bench, and the front end of its cylinder rod is connected to the second pin passing through the guide groove. The first pin and the second pin are connected by two oppositely arranged connecting plates;

[0036] Control the test cylinder to extend or retract, so that the second pin slides in the guide groove, and the force is transmitted to the loading cylinder through the connecting plate and the first pin.

[0037] Optionally, when conducting the extension test on the test cylinder, the first hydraulic oil source is connected to the rodless cavity of the loading cylinder, and the rod chamber of the loading cylinder is connected to the fuel tank; the second hydraulic oil source is connected to the rodless cavity of the test cylinder, and the rod chamber of the test cylinder is connected to the fuel tank;

[0038] The internal pressure of the rodless cavity of the test oil cylinder is regulated by a proportional relief valve, and the calculation formula is:

[0039]

[0040] where P3 is the internal pressure of the rodless cavity of the test oil cylinder, A1 is the area of the rodless cavity of the loading cylinder, A3 is the area of the rodless cavity of the test cylinder, and P 加 is the loading pressure generated by the proportional relief valve;

[0041] When the test cylinder is fully extended, since the stroke of the loading cylinder is greater than that of the test cylinder and the loading cylinder is not fully retracted, the internal pressure of the rodless cavity of the test oil cylinder is regulated by the safety valve;

[0042] When conducting the retraction test on the test cylinder, the first hydraulic oil source is connected to the rod chamber of the loading cylinder, and the rodless cavity of the loading cylinder is connected to the fuel tank; the second hydraulic oil source is connected to the rod chamber of the test cylinder, and the rodless cavity of the test cylinder is connected to the fuel tank;

[0043] The internal pressure of the rod chamber of the test oil cylinder is regulated by a proportional relief valve, and the calculation formula is:

[0044]

[0045] where P4 is the internal pressure of the rod chamber of the test oil cylinder, A2 is the area of the rod chamber of the loading cylinder, A3 is the area of the rod chamber of the test cylinder, and P 加 is the loading pressure generated by the proportional relief valve;

[0046] When the test cylinder is fully retracted, since the stroke of the loading cylinder is greater than that of the test cylinder and the loading cylinder is not fully extended, the internal pressure of the rod chamber of the test oil cylinder is regulated by the safety valve.

[0047] Compared with the prior art, the beneficial effects of the present invention are:

[0048] The general hydraulic cylinder test device proposed by the present invention can be applied to the loading tests of different cylinders to be tested, and has strong applicability.

[0049] For the general hydraulic cylinder test device proposed by the present invention, the front parts of the piston rods of the loading cylinder and the cylinder to be tested are both connected to the test bench through pin shafts, and a guide groove is designed, which can effectively avoid damage to the piston rod.

[0050] For the general hydraulic cylinder test device proposed by the present invention, protective parts are added near the loading cylinder and the cylinder to be tested, and adjusting parts with threads are further added to adjust the gap between the protective part and the cylinder to be tested, preventing the cylinder from bending excessively.

[0051] In the present invention, the problem of mismatch between the cylinder to be tested and the pin shaft is solved by designing a pin shaft sleeve.

[0052] In the present invention, by designing proportional overflow valves (i.e., proportional adjustment devices) for the rod chamber and the rodless chamber of the loading cylinder, the loading tests of different cylinders to be tested can be matched. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to make the content of the present invention be understood more clearly, the following further describes the present invention in detail according to specific embodiments and in conjunction with the drawings, wherein:

[0054] Figure 1 is a schematic structural diagram of a hydraulic cylinder test device in the prior art;

[0055] Figure 2 is one of the schematic overall structural diagrams of the general hydraulic cylinder test device in an embodiment of the present invention;

[0056] Figure 3 is a sectional view of the general hydraulic cylinder test device in an embodiment of the present invention;

[0057] Figure 4 is an exploded view of the general hydraulic cylinder test device in an embodiment of the present invention;

[0058] Figure 5 is Figure 4 an enlarged schematic view of part A in

[0059] Figure 6 is the other schematic overall structural diagram of the general hydraulic cylinder test device in an embodiment of the present invention;

[0060] Wherein:

[0061] 1 - Test bench, 2 - Loading cylinder, 3 - Cylinder under test, 4 - Guide groove, 5 - First pin shaft, 6 - Second pin shaft, 7 - Gasket, 8 - Connecting plate, 9 - First protection part, 10 - Second protection part, 11 - Third protection part, 12 - Fourth protection part, 13 - First reversing valve, 14 - Second reversing valve, 15 - Safety valve, 16 - Proportional overflow valve, 17 - First hydraulic oil source, 18 - Second hydraulic oil source, 19 - Pin shaft sleeve, 20 - Gap, 21 - Threaded adjusting part, 22 - Cylinder barrel base of the loading cylinder, 23 - Cylinder rod of the loading cylinder, 24 - Cylinder barrel base of the cylinder under test, 25 - Guide rail of the first protection device, 26 - First slider, 27 - Guide rail of the second protection device, 28 - Lower slider bolt, 29 - Fixing nut, 30 - Cylinder rod of the cylinder under test. Detailed implementation manner

[0062] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the protection scope of the present invention.

[0063] The application principle of the present invention will be described in detail below with reference to the drawings.

[0064] Embodiment 1

[0065] In an embodiment of the present invention, a general hydraulic cylinder test device is provided, including: a test bench 1, a loading cylinder 2, and a cylinder under test 3;

[0066] A guide groove 4 is provided on the test bench 1;

[0067] The cylinder barrel base 22 of the loading cylinder 2 is connected to the test bench 1, and the front end of its cylinder rod 23 is connected to the first pin shaft 5 passing through the guide groove 4;

[0068] The stroke of the cylinder under test 3 is less than the stroke of the loading cylinder 2. Its cylinder barrel base 24 is connected to the test bench 1, and the front end of its cylinder rod 30 is connected to the second pin shaft 6 passing through the guide groove 4. And the first pin shaft 5 and the second pin shaft 6 are connected by two oppositely arranged connecting plates 8; In the specific implementation process, gaskets 7 are provided on both the first pin shaft 5 and the second pin shaft 6, and the gaskets 7 are used to fill the gap 20 between the ends of the loading cylinder 2 and the cylinder under test 3 and the test bench 1;

[0069] When the cylinder under test 3 extends or retracts, the second pin shaft 6 slides in the guide groove 4 and transmits force to the loading cylinder 2 through the connecting plate 8 and the first pin shaft 5.

[0070] It can be seen that the general hydraulic cylinder test device in the embodiment of the present invention can be applicable to the loading tests of different cylinders under test 3, and has strong applicability.

[0071] In a specific implementation manner of the embodiment of the present invention, as Figure 6 shown, the general hydraulic cylinder test device further includes a first reversing valve 13, a second reversing valve 14, a safety valve 15, a proportional overflow valve 16, a first hydraulic oil source 17, and a second hydraulic oil source 18;

[0072] The first reversing valve 13 is respectively connected to the rodless cavity and the rod cavity of the loading cylinder 2, and is also connected to the first hydraulic oil source 17;

[0073] The proportional overflow valve 16 is arranged between the first hydraulic oil source 17 and the first reversing valve 13;

[0074] The second reversing valve 14 is respectively connected to the rodless cavity and the rod cavity of the cylinder under test 3, and is also connected to the second hydraulic oil source 18;

[0075] The safety valve 15 is arranged between the second hydraulic oil source 18 and the second reversing valve 14.

[0076] When conducting an extension test on the cylinder under test 3, the first hydraulic oil source 17 is communicated with the rodless cavity of the loading cylinder 2, and the rod cavity of the loading cylinder 2 is communicated with the fuel tank; the second hydraulic oil source 18 is communicated with the rodless cavity of the cylinder under test 3, and the rod cavity of the cylinder under test 3 is communicated with the fuel tank;

[0077] The internal pressure of the rodless cavity of the cylinder under test is regulated by the proportional overflow valve 16, and the calculation formula is:

[0078]

[0079] where P3 is the internal pressure of the rodless cavity of the cylinder under test, A1 is the area of the rodless cavity of the loading cylinder 2, A3 is the area of the rodless cavity of the cylinder under test 3, and P 加 is the loading pressure generated by the proportional overflow valve 16;

[0080] When the cylinder under test 3 is fully extended, since the stroke of the loading cylinder 2 is greater than the stroke of the cylinder under test 3 and the loading cylinder 2 is not fully retracted, the internal pressure of the rodless cavity of the cylinder under test is regulated by the safety valve 15.

[0081] When conducting a retraction test on the cylinder under test 3, the first hydraulic oil source 17 is communicated with the rod cavity of the loading cylinder 2, and the rodless cavity of the loading cylinder 2 is communicated with the fuel tank; the second hydraulic oil source 18 is communicated with the rod cavity of the cylinder under test 3, and the rodless cavity of the cylinder under test 3 is communicated with the fuel tank;

[0082] The internal pressure of the rod cavity of the cylinder under test is regulated by the proportional overflow valve 16, and the calculation formula is:

[0083]

[0084] Wherein, P4 is the internal pressure of the rod chamber of the tested oil cylinder, A2 is the area of the rod chamber of the loading cylinder 2, A3 is the area of the rod chamber of the tested cylinder 3, and P 加 is the loading pressure generated by the proportional overflow valve 16;

[0085] When the tested cylinder 3 is fully retracted, since the stroke of the loading cylinder 2 is greater than that of the tested cylinder 3 and the loading cylinder 2 is not fully extended, the internal pressure of the rod chamber of the tested oil cylinder is regulated by the safety valve 15.

[0086] In a specific embodiment of the embodiment of the present invention, as Figure 2-3 shown, the general hydraulic cylinder test device further includes a first protection member 9 (i.e., the upper protection member) and a second protection member 10 (i.e., the lower protection member) which are oppositely arranged, and the two are respectively fixedly arranged at preset positions on the loading cylinder 2, and there is a preset gap 20 between them and the loading cylinder 2, and they are used in cooperation to ensure that the loading cylinder 2 does not deform.

[0087] In a specific embodiment of the embodiment of the present invention, as Figure 2-3 shown, the general hydraulic cylinder test device further includes a third protection member 11 (i.e., the upper protection member) and a fourth protection member 12 (i.e., the lower protection member) which are oppositely arranged, and the two are respectively movably arranged at preset positions on the tested cylinder 3, and there is a preset gap 20 between them and the tested cylinder 3, and they are used in cooperation to ensure that the tested cylinder 3 does not deform.

[0088] Further, in order to facilitate adjusting the installation position and installation height of the protection member according to the size of the tested cylinder 3 and improve the protection effect, a first protection device guide rail 27 and a second protection device guide rail 25 are provided on the test bench 1; a first slider 26 is slidably arranged in the first protection device guide rail 27; a second slider is slidably arranged in the second protection device guide rail 25; the third protection member 11 is connected to the first slider 26 through an adjusting member 21 with a thread; the fourth protection member 12 is connected to the second slider through an adjusting member 21 with a thread. In the specific implementation process, the second slider is installed on the second protection device guide rail 25 through a lower slider bolt 28 and a fixing nut 29.

[0089] In a specific embodiment of the embodiment of the present invention, in order to solve the problem of mismatch between different tested cylinders 3 and the second pin shaft 6, for tested cylinders 3 of different sizes, a pin shaft sleeve 19 is arranged between the base of the tested cylinder 3 and the second pin shaft 6, the inner diameter of the pin shaft sleeve 19 is the same as the outer diameter of the second pin shaft 6, and its outer diameter is the same as the inner diameter of the base of the tested cylinder 3.

[0090] Next, a specific embodiment is used to illustrate the general hydraulic cylinder test device in the embodiment of the present invention in detail.

[0091] The loading cylinder 2 is a fixed cylinder, designed as a hydraulic cylinder with a relatively thick cylinder diameter and a long stroke. The cylinder barrel base of the loading cylinder 2 is connected to the third pin shaft passing through the test bench 1 and the gasket 7, and the front end of the cylinder rod of the loading cylinder 2 is connected to the first pin shaft 5 passing through the guide groove 4 and the gasket 7; the cylinder barrel base of the tested cylinder 3 (which can vary according to actual requirements) is connected to the fourth pin shaft passing through the test bench 1 and the gasket 7, and the front end of the cylinder rod of the tested cylinder 3 is connected to the second pin shaft 6 passing through the guide groove 4 and the gasket 7; the front parts of the cylinder rods of the loading cylinder 2 and the tested cylinder 3 are connected by two connecting plates 8. When the tested cylinder 3 extends and retracts, it is guided by the guide groove 4 in front of the cylinder rod, and the force is transmitted to the loading cylinder 2 through the connecting plate 8.

[0092] Since the loading cylinder 2 in the embodiment of the present invention adopts a fixed cylinder, the first protective member 9 can be fixed at a fixed position by bolts, and the second protective member 10 is welded to the test bench 1, leaving a small gap 20 between the first protective member 9 and the second protective member 10 and the loading cylinder 2 to prevent excessive deformation of the loading oil cylinder up and down due to excessive force.

[0093] The tested cylinder 3 in the embodiment of the present invention is a variable oil cylinder, and the length of the oil cylinder, the dimension matching with the pin shaft, and the stroke will all change. To meet the installation requirements of a general oil cylinder, the positions of the third protective member 11 and the fourth protective member 12 need to be adjusted according to the length change of the tested cylinder 3 (the front end of the cylinder barrel is the midpoint of the entire length after the cylinder rod extends, and it is also the point with the largest deformation amount, and this place needs to be protected), and the stroke of the loading cylinder 2 needs to be adjusted according to the stroke of the tested cylinder 3.

[0094] For this reason, the embodiment of the present invention proposes: connecting the third protective member 11 to the first slider 26, the first slider 26 can move along the first protective device guide rail 27 to adjust the position in the length direction, and the threaded adjusting member 21 can adjust the up and down position of the third protective member 11. The fourth protective member 12 is connected to the second slider, the second slider can move along the second protective device guide rail 25 to adjust the position in the length direction, and after moving to the required position, it can be fixed with a fixing nut, and then the up and down position of the fourth protective member 12 is adjusted through the threaded adjusting member 21. When testing different tested cylinders 3, only a pin shaft sleeve 19 with the same outer diameter as the pin shaft and the same inner diameter as the base of the tested cylinder 3 needs to be processed.

[0095] As Figure 6 shown, the loading cylinder 2 is a fixed oil cylinder: the area of the rodless cavity is A1, the internal pressure is P1, the area of the rod cavity is A2, and the internal pressure is P2. The reversing valve 1 can switch to load the rodless cavity or the rod cavity, and the proportional overflow valve 16 can adjust the loading pressure P according to requirements 加。

[0096] The test cylinder 3 is a variable cylinder. However, after the test cylinder 3 is determined, the area of the rodless cavity of the test cylinder 3 can be calculated as A3 according to the design drawing, the internal pressure is P3, the area of the rod cavity is A4, and the internal pressure is P4. The directional control valve 2 can be switched to test the rodless cavity or the rod cavity.

[0097] When performing the extension test on the test cylinder 3, the positions of the directional control valves 1 and 2 are as Figure 5 shown. The oil source of the loading cylinder 2 is connected to the rodless cavity, and the rod cavity is connected to the fuel tank. The oil source of the test cylinder 3 is connected to the rodless cavity, and the rod cavity is connected to the fuel tank.

[0098] P3×A3 - P4×A4 = P1×A1 - P2×A2

[0099] Since the rod cavities of the loading cylinder 2 and the test cylinder 3 are both connected to the fuel tank at this time, the pressures P2 and P4 can be considered to be 0; the internal pressure P1 in the rodless cavity of the loading cylinder 2 can be set by adjusting P 加 The above formula can be changed to

[0100]

[0101] By proportionally adjusting the P 加 pressure, the test pressure P3 inside the rodless cavity of the test cylinder 3 can be adjusted. When the test cylinder 3 is fully extended, since the loading cylinder 2 is longer than the test cylinder 3 and the loading cylinder 2 is not fully retracted, the pressure buildup pressure in the rodless cavity of the test cylinder 3 can be set by the pressure of the safety valve 15.

[0102] When performing the retraction test on the test cylinder 3, Figure 5 the directional control valves 1 and 2 in

[0103] both switch directions. The oil source of the loading cylinder 2 is connected to the rod cavity, and the rodless cavity is connected to the fuel tank. The oil source of the test cylinder 3 is connected to the rod cavity, and the rodless cavity is connected to the fuel tank.

[0104] Since the rodless cavities of the loading cylinder 2 and the test cylinder 3 are both connected to the fuel tank at this time, the pressures P1 and P3 can be considered to be 0; the internal pressure P2 in the rod cavity of the loading cylinder 2 can be set by adjusting P 加 The above formula can be changed to

[0105]

[0106] By proportionally adjusting the P 加 pressure, the test pressure P4 inside the rod cavity of the test cylinder 3 can be adjusted. When the test cylinder 3 is fully retracted, since the loading cylinder 2 is longer than the test cylinder 3 and the loading cylinder 2 is not fully retracted, the pressure buildup pressure in the rod cavity of the test cylinder 3 can be set by the pressure of the safety valve 15.

[0107] Thus, the installation and loading of the general test oil cylinder are realized.

[0108] Embodiment 2

[0109] The present invention provides a general hydraulic cylinder test method, including the following steps:

[0110] (1) Install the loading cylinder 2 on the test bench 1. The cylinder base of the loading cylinder 2 is connected to the test bench 1, and the front end of its cylinder rod is connected to the first pin shaft 5 passing through the guide groove 4;

[0111] (2) Install the cylinder under test 3 on the test bench 1. The stroke of the cylinder under test 3 is less than that of the loading cylinder 2. Its cylinder base is connected to the test bench 1, and the front end of its cylinder rod is connected to the second pin shaft 6 passing through the guide groove 4. Moreover, the first pin shaft 5 and the second pin shaft 6 are connected through two oppositely arranged connecting plates 8;

[0112] (3) Control the cylinder under test 3 to extend or retract, so that the second pin shaft 6 slides in the guide groove 4, and the force is transmitted to the loading cylinder 2 through the connecting plate 8 and the first pin shaft 5.

[0113] In a specific embodiment of the embodiment of the present invention, when the cylinder under test 3 is subjected to an extension test, the first hydraulic oil source 17 is communicated with the rodless cavity of the loading cylinder 2, and the rod chamber of the loading cylinder 2 is communicated with the fuel tank; the second hydraulic oil source 18 is communicated with the rodless cavity of the cylinder under test 3, and the rod chamber of the cylinder under test 3 is communicated with the fuel tank;

[0114] The internal pressure of the rodless cavity of the cylinder under test is adjusted by the proportional relief valve 16, and the calculation formula is:

[0115]

[0116] Among them, P3 is the internal pressure of the rodless cavity of the cylinder under test, A1 is the area of the rodless cavity of the loading cylinder 2, A3 is the area of the rodless cavity of the cylinder under test 3, and P 加 is the loading pressure generated by the proportional relief valve 16;

[0117] When the cylinder under test 3 is fully extended, since the stroke of the loading cylinder 2 is greater than that of the cylinder under test 3 and the loading cylinder 2 is not fully retracted, the internal pressure of the rodless cavity of the cylinder under test is adjusted by the safety valve 15;

[0118] When the cylinder under test 3 is subjected to a retraction test, the first hydraulic oil source 17 is communicated with the rod chamber of the loading cylinder 2, and the rodless cavity of the loading cylinder 2 is communicated with the fuel tank; the second hydraulic oil source 18 is communicated with the rod chamber of the cylinder under test 3, and the rodless cavity of the cylinder under test 3 is communicated with the fuel tank;

[0119] The internal pressure of the rod chamber of the cylinder under test is adjusted by the proportional relief valve 16, and the calculation formula is:

[0120]

[0121] Among them, P4 is the internal pressure of the rod chamber of the test cylinder, A2 is the area of the rod chamber of the loading cylinder 2, A3 is the area of the rod chamber of the test cylinder 3, and P 加 is the loading pressure generated by the proportional overflow valve 16;

[0122] When the test cylinder 3 is fully retracted, since the stroke of the loading cylinder 2 is greater than that of the test cylinder 3 and the loading cylinder 2 is not fully extended, the internal pressure of the rod chamber of the test cylinder is regulated by the safety valve 15.

[0123] The method in the embodiment of the present invention can also be implemented based on the general hydraulic cylinder test device in Embodiment 1.

[0124] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A general hydraulic cylinder test device, characterized in that, Comprising: A test bench, on which a guiding groove is provided; A loading cylinder, the cylinder base of the loading cylinder is connected to the test bench, and the front end of its cylinder rod is connected to a first pin shaft passing through the guiding groove; A cylinder under test, the stroke of the cylinder under test is less than that of the loading cylinder, its cylinder base is connected to the test bench, the front end of its cylinder rod is connected to a second pin shaft passing through the guiding groove, and the first pin shaft and the second pin shaft are connected by two oppositely arranged connecting plates; When the cylinder under test extends or retracts, the second pin shaft slides in the guiding groove, and force transmission is carried out with the loading cylinder through the connecting plate and the first pin shaft; The general hydraulic cylinder test device further includes a first reversing valve, a second reversing valve, a safety valve, a proportional overflow valve, a first hydraulic oil source and a second hydraulic oil source; The first reversing valve is respectively connected to the rod chamber and the rodless chamber of the loading cylinder, and is also connected to the first hydraulic oil source; The proportional overflow valve is arranged between the first hydraulic oil source and the first reversing valve; The second reversing valve is respectively connected to the rod chamber and the rodless chamber of the cylinder under test, and is also connected to the second hydraulic oil source; The safety valve is arranged between the second hydraulic oil source and the second reversing valve; When performing an extension test on the cylinder under test, the first hydraulic oil source is communicated with the rodless chamber of the loading cylinder, and the rod chamber of the loading cylinder is communicated with the oil tank; the second hydraulic oil source is communicated with the rodless chamber of the cylinder under test, and the rod chamber of the cylinder under test is communicated with the oil tank; The internal pressure of the rodless chamber of the cylinder under test is adjusted by the proportional overflow valve, and the calculation formula is: Among them, P3 is the internal pressure of the rodless cavity of the test cylinder, A1 is the area of the rodless cavity of the loading cylinder, A3 is the area of the rodless cavity of the test cylinder, and P 加 is the loading pressure generated by the proportional overflow valve; When the cylinder under test is fully extended, since the stroke of the loading cylinder is greater than that of the cylinder under test and the loading cylinder is not fully retracted, the internal pressure of the rodless chamber of the cylinder under test is adjusted by the safety valve; When performing a retraction test on the cylinder under test, the first hydraulic oil source is communicated with the rod chamber of the loading cylinder, and the rodless chamber of the loading cylinder is communicated with the oil tank; the second hydraulic oil source is communicated with the rod chamber of the cylinder under test, and the rodless chamber of the cylinder under test is communicated with the oil tank; The internal pressure of the rod chamber of the cylinder under test is adjusted by the proportional overflow valve, and the calculation formula is: Among them, P4 is the internal pressure of the rod chamber of the test cylinder, A2 is the area of the rod chamber of the loading cylinder, A3 is the area of the rod chamber of the test cylinder, and P 加 is the loading pressure generated by the proportional overflow valve; When the cylinder under test is fully retracted, since the stroke of the loading cylinder is greater than that of the cylinder under test and the loading cylinder is not fully extended, the internal pressure of the rod chamber of the cylinder under test is adjusted by the safety valve.

2. The general hydraulic cylinder test device according to claim 1, wherein: The general hydraulic cylinder test device further includes a first protection member and a second protection member which are oppositely arranged, and the two are respectively fixedly arranged at preset positions on the loading cylinder, with a preset gap between them and the loading cylinder, and are used in cooperation to ensure that the loading cylinder does not deform.

3. A general hydraulic cylinder test device according to claim 1, characterized in that: The general hydraulic cylinder test device further includes a third protection member and a fourth protection member which are oppositely arranged, and the two are respectively movably arranged at preset positions on the cylinder under test, with a preset gap between them and the cylinder under test, and are used in cooperation to ensure that the cylinder under test does not deform.

4. A general hydraulic cylinder test device according to claim 3, characterized in that: The test bench is provided with a first protection device guide rail and a second protection device guide rail; a first slider is slidably arranged in the first protection device guide rail; a second slider is slidably arranged in the second protection device guide rail; the third protection member is connected to the first slider through an adjusting member with a thread; the fourth protection member is connected to the second slider through an adjusting member with a thread.

5. A general hydraulic cylinder test device according to claim 1, characterized in that: Gaskets are provided on both the first pin shaft and the second pin shaft, and the gaskets are used to fill the gaps between the loading cylinder and the tested cylinder ends and the test bench; for tested cylinders of different sizes, a pin bushing is provided between the base of the tested cylinder and the second pin shaft, and the inner diameter of the pin bushing is the same as the outer diameter of the second pin shaft, and its outer diameter is the same as the inner diameter of the base of the tested cylinder.

6. A general hydraulic cylinder test method, characterized in that, It includes: Install the loading cylinder onto the test bench, where the cylinder base of the loading cylinder is connected to the test bench, and the front end of its cylinder rod is connected to the first pin shaft passing through the guide groove; Install the tested cylinder onto the test bench, where the stroke of the tested cylinder is less than that of the loading cylinder, its cylinder base is connected to the test bench, and the front end of its cylinder rod is connected to the second pin shaft passing through the guide groove, and the first pin shaft and the second pin shaft are connected by two oppositely arranged connecting plates; Control the tested cylinder to extend or retract, so that the second pin shaft slides in the guide groove, and force is transmitted to the loading cylinder through the connecting plate and the first pin shaft; The universal hydraulic cylinder test device further includes a first directional control valve, a second directional control valve, a safety valve, a proportional relief valve, a first hydraulic oil source, and a second hydraulic oil source; The first directional control valve is respectively connected to the rod chamber and the rodless chamber of the loading cylinder, and is also connected to the first hydraulic oil source; the proportional relief valve is arranged between the first hydraulic oil source and the first directional control valve; The second directional control valve is respectively connected to the rod chamber and the rodless chamber of the tested cylinder, and is also connected to the second hydraulic oil source; the safety valve is arranged between the second hydraulic oil source and the second directional control valve; When conducting an extension test on the tested cylinder, the first hydraulic oil source is connected to the rodless chamber of the loading cylinder, and the rod chamber of the loading cylinder is connected to the oil tank; the second hydraulic oil source is connected to the rodless chamber of the tested cylinder, and the rod chamber of the tested cylinder is connected to the oil tank; The internal pressure of the rodless chamber of the tested oil cylinder is adjusted by the proportional relief valve, and the calculation formula is: Wherein, P3 is the internal pressure of the rodless cavity of the test cylinder, A1 is the area of the rodless cavity of the loading cylinder, A3 is the area of the rodless cavity of the test cylinder, and P 加 is the loading pressure generated by the proportional overflow valve; When the tested cylinder is fully extended, since the stroke of the loading cylinder is greater than that of the tested cylinder and the loading cylinder is not fully retracted, the internal pressure of the rodless chamber of the tested oil cylinder is adjusted by the safety valve; When conducting a retraction test on the tested cylinder, the first hydraulic oil source is connected to the rod chamber of the loading cylinder, and the rodless chamber of the loading cylinder is connected to the oil tank; the second hydraulic oil source is connected to the rod chamber of the tested cylinder, and the rodless chamber of the tested cylinder is connected to the oil tank; The internal pressure of the rod chamber of the tested oil cylinder is adjusted by the proportional relief valve, and the calculation formula is: Wherein, P4 is the internal pressure of the rod chamber of the tested oil cylinder, A2 is the area of the rod chamber of the loading cylinder, A3 is the area of the rod chamber of the tested cylinder, and P 加 is the loading pressure generated by the proportional overflow valve; When the tested cylinder is fully retracted, since the stroke of the loading cylinder is greater than that of the tested cylinder and the loading cylinder is not fully extended, the internal pressure of the rod chamber of the tested oil cylinder is adjusted by the safety valve.

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