Platform leveling system, aerial work platform and aerial work machine

Abstract

The application discloses a platform leveling system, an aerial work platform and an aerial work machine, and relates to the technical field of aerial work platforms. The platform leveling system comprises a rotating table, an arm support assembly, a work platform and a leveling loop. The arm support assembly comprises a first arm support and a second arm support which are hingedly connected. The first arm support is hingedly connected with the work platform, and the second arm support is hingedly connected with the rotating table. The leveling loop comprises a first leveling oil cylinder, a second leveling oil cylinder and a third leveling oil cylinder. The two ends of the first leveling oil cylinder are hingedly connected with the first arm support and the work platform respectively. The two ends of the second leveling oil cylinder are hingedly connected with the first arm support and the second arm support respectively. The two ends of the third leveling oil cylinder are hingedly connected with the second arm support and the rotating table respectively. The rod cavities of the first leveling oil cylinder, the second leveling oil cylinder and the third leveling oil cylinder are connected to form a closed oil circuit, and the non-rod cavities of the three are connected to form a closed oil circuit. The specifications of the first leveling oil cylinder, the second leveling oil cylinder and the third leveling oil cylinder are the same. The platform leveling angle is accurately matched with the arm support amplitude change.

Description

TECHNICAL FIELD

[0001] The present application relates to a hydraulic leveling mechanism, in particular to a platform leveling system. In addition, it also relates to an aerial work platform and an aerial work machine. BACKGROUND

[0002] Generally, the aerial work machine is provided with a manned work platform or a functional accessory. During operation, the manned work platform or the functional accessory always needs to be leveled with the ground, or in other words, the angle of the manned work platform or the functional accessory relative to the ground always remains unchanged regardless of the change of the angle of the boom. Therefore, a leveling mechanism or system is required to adjust the angle of the manned work platform or the functional accessory according to the change of the angle of the boom.

[0003] The angle adjustment of the manned work platform can be in a manual or automatic manner. The manual angle adjustment has a low efficiency and is generally used for the initial angle setting or the angle error elimination of the manned work platform. The automatic angle adjustment of the manned work platform following the change of the angle of the boom can effectively avoid human errors and prevent the occurrence of personnel and goods falling accidents to the maximum extent from the operation level.

[0004] For the aerial work platform with a mixed boom structure having forward and reverse movements, the manned work platform generally adopts an electro-hydraulic leveling mode due to the structural characteristics. However, the electro-hydraulic leveling mode has a higher cost and energy consumption, more fault points and poorer reliability compared with the mechanical-hydraulic leveling mode.

[0005] Therefore, a platform leveling system needs to be designed to overcome or alleviate the above technical problems. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a platform leveling system which has a lower cost and energy consumption, fewer fault points, better reliability and can ensure that the leveling angle of the platform accurately matches the change of the angle of the boom.

[0007] The further technical problem to be solved by the present application is an aerial work platform which can ensure that the leveling angle of the platform accurately matches the change of the angle of the boom.

[0008] The further technical problem to be solved by the present application is an aerial work machine, and the aerial work platform of the aerial work machine has good leveling safety.

[0009] To solve the above technical problems, the first aspect of the present application provides a platform leveling system, comprising a rotating table, an arm support assembly, a working platform and a leveling loop, the arm support assembly comprises a first arm support and a second arm support which are hingedly connected, the first arm support is hingedly connected with the working platform, the second arm support is hingedly connected with the rotating table, the leveling loop comprises a first leveling oil cylinder, a second leveling oil cylinder and a third leveling oil cylinder, the two ends of the first leveling oil cylinder are hingedly connected with the first arm support and the working platform respectively, the two ends of the second leveling oil cylinder are hingedly connected with the first arm support and the second arm support respectively, the two ends of the third leveling oil cylinder are hingedly connected with the second arm support and the rotating table respectively, the three rod cavities of the first leveling oil cylinder, the second leveling oil cylinder and the third leveling oil cylinder are connected to form a closed oil circuit, and the three rodless cavities of the first leveling oil cylinder, the second leveling oil cylinder and the third leveling oil cylinder are connected to form a closed oil circuit, and the first leveling oil cylinder, the second leveling oil cylinder and the third leveling oil cylinder are of the same specification.

[0010] In some embodiments, the first end of the first arm support is hingedly connected with the working platform through a first hinge point, the first end of the first leveling oil cylinder is hingedly connected with the working platform through a second hinge point, the second end of the first leveling oil cylinder is hingedly connected with the first end of the first arm support through a third hinge point, the second end of the first arm support is hingedly connected with the first end of the second arm support through a fourth hinge point, the first end of the second leveling oil cylinder is hingedly connected with the second end of the first arm support through a fifth hinge point, the second end of the second leveling oil cylinder is hingedly connected with the first end of the second arm support through a sixth hinge point, the second end of the second arm support is hingedly connected with the rotating table through a seventh hinge point, the first end of the third leveling oil cylinder is hingedly connected with the second end of the second arm support through an eighth hinge point, and the second end of the third leveling oil cylinder is hingedly connected with the rotating table through a ninth hinge point; when the first leveling oil cylinder, the second leveling oil cylinder and the third leveling oil cylinder are all in the fully extended or fully retracted state, the triangle formed by the first hinge point, the second hinge point and the third hinge point, the triangle formed by the fourth hinge point, the fifth hinge point and the sixth hinge point, and the triangle formed by the seventh hinge point, the eighth hinge point and the ninth hinge point are all congruent.

[0011] In some embodiments, the seventh hinge point is located between the fourth hinge point and the eighth hinge point.

[0012] In some embodiments, a first luffing oil cylinder is installed between the first arm support and the second arm support, a second luffing oil cylinder is installed between the second arm support and the rotating table, the first luffing oil cylinder and the second luffing oil cylinder are connected with a multi-way valve, and a second arm support luffing safety limiting oil circuit is arranged between the rod cavity and the rodless cavity of the second luffing oil cylinder.

[0013] In some embodiments, the second arm frame luffing safety limiting oil circuit comprises a first limiting oil circuit connected between the rod cavity and the rodless cavity of the second luffing cylinder, and a motorized reversing valve and a first check valve capable of unidirectionally guiding the oil in the rod cavity of the second luffing cylinder to the oil circuit connected to the rodless cavity of the second luffing cylinder are arranged on the first limiting oil circuit, and the control end of the motorized reversing valve is opposite to the first arm frame.

[0014] In some embodiments, the second arm frame luffing safety limiting oil circuit comprises a second limiting oil circuit connected between the rod cavity and the rodless cavity of the second luffing cylinder, and a first electromagnetic reversing valve and a second check valve capable of unidirectionally guiding the oil in the rod cavity of the second luffing cylinder to the oil circuit connected to the rodless cavity of the second luffing cylinder are arranged on the second limiting oil circuit.

[0015] In some embodiments, a first arm frame luffing safety limiting oil circuit is arranged between the rod cavity and the rodless cavity of the first luffing cylinder.

[0016] In some embodiments, a second electromagnetic reversing valve and a third check valve capable of unidirectionally guiding the oil in the rodless cavity of the first luffing cylinder to the rod cavity of the first luffing cylinder are arranged on the first arm frame luffing safety limiting oil circuit.

[0017] In some embodiments, a first balance valve is arranged between the first luffing cylinder and the multi-way valve, and a second balance valve is arranged between the second luffing cylinder and the multi-way valve.

[0018] In some embodiments, a one-way cut-off reversing valve is connected to the oil inlet of the multi-way valve.

[0019] In some embodiments, the leveling circuit further comprises a reversing valve and a holding valve, and the reversing valve is connected to the third leveling cylinder through the holding valve.

[0020] In some embodiments, a third balance valve is arranged between the first leveling cylinder and the second leveling cylinder.

[0021] The second aspect of the present application provides a work platform, which is provided with the platform leveling system according to any one of the above technical solutions.

[0022] The third aspect of the present application provides a working platform, which is provided with the working platform according to the above technical solution.

[0023] Through the above technical solution, the present application has the following beneficial effects:

[0024] By connecting the three rod cavities of the first leveling oil cylinder, the second leveling oil cylinder and the third leveling oil cylinder to form a closed oil circuit and connecting the three rodless cavities to form a closed oil circuit, and by using the first leveling oil cylinder, the second leveling oil cylinder and the third leveling oil cylinder with the same specifications, the extension and retraction length change amounts of the first leveling oil cylinder, the second leveling oil cylinder and the third leveling oil cylinder are completely equal when the three cylinders are linked, and the working platform leveling angle is accurately matched with the amplitude change of the arm support.

[0025] Further, the distances between the hinge points of the first leveling oil cylinder, the second leveling oil cylinder and the third leveling oil cylinder and the hinge points of the first arm support, the second arm support and the rotating table are reasonably set, so that when the first leveling oil cylinder, the second leveling oil cylinder and the third leveling oil cylinder are in the fully extended or fully retracted state, the triangles formed by the first hinge point, the second hinge point and the third hinge point, the triangles formed by the fourth hinge point, the fifth hinge point and the sixth hinge point, and the triangles formed by the seventh hinge point, the eighth hinge point and the ninth hinge point are all equal, and the extension and retraction length change amounts of the first leveling oil cylinder, the second leveling oil cylinder and the third leveling oil cylinder are completely equal when the three cylinders are linked, and the working platform leveling angle is accurately matched with the amplitude change of the arm support.

[0026] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0028] Figure 1 is one of the structural schematic diagrams of the platform leveling system disclosed by the specific embodiments of the present application;

[0029] Figure 2 is the second structural schematic diagram of the platform leveling system disclosed by the specific embodiments of the present application;

[0030] Figure 3 is the third structural schematic diagram of the platform leveling system disclosed by the specific embodiments of the present application;

[0031] Figure 4 is the fourth structural schematic diagram of the platform leveling system disclosed by the specific embodiments of the present application;

[0032] Figure 5is the hydraulic principle diagram of the platform leveling system disclosed by the first embodiment of the present application;

[0033] Figure 6 is the hydraulic principle diagram of the platform leveling system disclosed by the second embodiment of the present application.

[0034] Explanation of reference signs

[0035] 1 turntable 2 working platform

[0036] 31 first arm support 32 second arm support

[0037] 41 first leveling oil cylinder 42 second leveling oil cylinder

[0038] 43 third leveling oil cylinder A first hinge point

[0039] B second hinge point C third hinge point

[0040] D fourth hinge point E fifth hinge point

[0041] F sixth hinge point G seventh hinge point

[0042] H eighth hinge point I ninth hinge point

[0043] 51 first amplitude cylinder 52 second amplitude cylinder

[0044] 6 multi-way valve 71 motorized directional valve

[0045] 72 first check valve 73 first electromagnetic directional valve

[0046] 74 second check valve 75 second electromagnetic directional valve

[0047] 76 third check valve 77 first balance valve

[0048] 78 second balance valve 79 check stop directional valve

[0049] 81 directional valve 82 holding valve

[0050] 83 third balance valve DETAILED DESCRIPTION

[0051] The embodiments of the present application will be further described in detail with reference to the drawings and examples. The detailed description and drawings of the following examples are used to exemplarily illustrate the principles of the present application, but cannot be used to limit the scope of the present application, and the present application can be implemented in many different forms, and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0052] It should be noted that in the description of the present application, unless otherwise specified and limited, the terms indicating the orientation or positional relationship are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements indicated 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. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0053] In addition, the "first", "second", "third", "fourth", "fifth", "sixth", "seventh", "eighth", "ninth" and similar words used in the present application do not indicate any order, quantity or importance, but are only used to distinguish different parts. "Parallel" is not strictly parallel, but within the allowable range of error. "Include" or "contain" and similar words mean that the elements before the word cover the elements listed after the word, and do not exclude the possibility of also covering other elements.

[0054] It should also be noted that in the description of the present application, unless otherwise specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. When it is described that a specific device is located between a first device and a second device, there can be or can not be an intermediate device between the specific device and the first device or the second device.

[0055] All terms used in the present application have the same meaning as understood by those skilled in the art to which the present application belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted to have meanings consistent with their meanings in the context of the relevant art, and should not be interpreted in an idealized or excessively formalized sense, unless otherwise defined explicitly herein.

[0056] Techniques, methods and equipment known to those skilled in the relevant art can not be discussed in detail, but in appropriate cases, the techniques, methods and equipment should be considered as part of the specification.

[0057] As Figures 1 to 4As shown, the present application provides a platform leveling system, which comprises a rotary table 1, an arm assembly, a working platform 2 and a leveling loop, the arm assembly comprises a first arm 31 and a second arm 32, the first arm 31 and the second arm 32 are hinged, the first arm 31 is hinged with the working platform 2, the second arm 32 is hinged with the rotary table 1, the leveling loop comprises a first leveling cylinder 41, a second leveling cylinder 42 and a third leveling cylinder 43, one end of the first leveling cylinder 41 is hinged with the first arm 31, and the other end thereof is hinged with the working platform 2, one end of the second leveling cylinder 42 is hinged with the first arm 31, and the other end thereof is hinged with the second arm 32, one end of the third leveling cylinder 43 is hinged with the second arm 32, and the other end thereof is hinged with the rotary table 1, the first leveling cylinder 41, the second leveling cylinder 42 and the third leveling cylinder 43 are connected in parallel, the rod cavity of the first leveling cylinder 41, the rod cavity of the second leveling cylinder 42 and the rod cavity of the third leveling cylinder 43 are connected to form a closed oil circuit, the rodless cavity of the first leveling cylinder 41, the rodless cavity of the second leveling cylinder 42 and the rodless cavity of the third leveling cylinder 43 are connected to form a closed oil circuit, and the first leveling cylinder 41, the second leveling cylinder 42 and the third leveling cylinder 43 adopt the same specification of cylinders. In this way, when the first leveling cylinder 41, the second leveling cylinder 42 and the third leveling cylinder 43 are linked, the length variation of the first leveling cylinder 41, the second leveling cylinder 42 and the third leveling cylinder 43 is completely equal, so as to ensure that the leveling angle of the working platform 2 is accurately matched with the amplitude variation of the arm.

[0058] It should be noted that, in order to facilitate understanding, the directions of the arm and the cylinder are defined, wherein, with reference to Figure 4 As shown, in the state of the first arm 31 and the second arm 32 being amplitude- varied and lifted, the first end refers to the end of the arm and the cylinder close to the working platform 2, and the second end refers to the end of the arm and the cylinder close to the rotary table 1.

[0059] In some embodiments, the first end of the first arm frame 31 is hinged with the working platform 2 through a first hinge point A, the first end of the first leveling oil cylinder 41 is hinged with the working platform 2 through a second hinge point B, the second end of the first leveling oil cylinder 41 is hinged with the first end of the first arm frame 31 through a third hinge point C, the second end of the first arm frame 31 is hinged with the first end of the second arm frame 32 through a fourth hinge point D, the first end of the second leveling oil cylinder 42 is hinged with the second end of the first arm frame 31 through a fifth hinge point E, the second end of the second leveling oil cylinder 42 is hinged with the first end of the second arm frame 32 through a sixth hinge point F, the second end of the second arm frame 32 is hinged with the rotating platform 1 through a seventh hinge point G, the first end of the third leveling oil cylinder 43 is hinged with the second end of the second arm frame 32 through an eighth hinge point H, and the second end of the third leveling oil cylinder 43 is hinged with the rotating platform 1 through a ninth hinge point I; when the first leveling oil cylinder 41, the second leveling oil cylinder 42 and the third leveling oil cylinder 43 are all in the full extension or full retraction state, the triangle formed by the first hinge point A, the second hinge point B and the third hinge point C, the triangle formed by the fourth hinge point D, the fifth hinge point E and the sixth hinge point F, and the triangle formed by the seventh hinge point G, the eighth hinge point H and the ninth hinge point I are all congruent.

[0060] When the first leveling oil cylinder 41, the second leveling oil cylinder 42 and the third leveling oil cylinder 43 are linked, the first leveling oil cylinder 41, the second leveling oil cylinder 42 and the third leveling oil cylinder 43 have the same change amount of extension or retraction length, so that the leveling angle of the working platform 2 can be accurately matched with the change of the arm frame amplitude. Moreover, the platform leveling system of the present application belongs to a mechanical hydraulic leveling system, which avoids the complicated hydraulic and electric control circuit of an electro-hydraulic leveling system, has fewer fault points and high reliability.

[0061] Generally, the hinge connection between the oil cylinder and the arm frame can be realized by setting a pin shaft, i.e. the hinge connection between the working platform 2 and the first arm frame 31, between the first leveling oil cylinder 41 and the working platform 2 and the first arm frame 31 respectively, between the first arm frame 31 and the second arm frame 32, between the second leveling oil cylinder 42 and the first arm frame 31 and the second arm frame 32 respectively, between the second arm frame 32 and the rotating platform 1, and between the third leveling oil cylinder 43 and the second arm frame 32 and the rotating platform 1 respectively.

[0062] In some embodiments, referring to Figure 1As shown, the first boom 31 and the second boom 32 are provided with a first luffing oil cylinder 51, and a connecting rod mechanism can be arranged between the first luffing oil cylinder 51 and the first boom 31 and the second boom 32. The first boom 31 is hingedly connected to the first end of the first luffing oil cylinder 51 through a connecting rod, one end of the second boom 32 is hingedly connected to the first end of the first luffing oil cylinder 51 through a connecting rod, and the second end of the first luffing oil cylinder 51 is hingedly connected to the other end of the second boom 32. The first luffing oil cylinder 51 can control the luffing of the first boom 31. When the piston rod of the first luffing oil cylinder 51 extends, the piston rod of the second leveling oil cylinder 42 extends.

[0063] In some embodiments, with reference to Figure 1 As shown, the seventh hinge point G is located between the fourth hinge point D and the eighth hinge point H, that is, the eighth hinge point H formed by the hingedly connected first end of the third leveling oil cylinder 43 and the second end of the second boom 32 is located at the tail end of the second boom 32. The tail end of the second boom 32 refers to the end region of the second boom 32 close to the turntable 1. At this time, the second luffing oil cylinder 52 and the third leveling oil cylinder 43 are located on both sides of the turntable 1. In this way, the movement direction of the piston rod of the first leveling oil cylinder 41 and the movement direction of the piston rod of the third leveling oil cylinder 43 are opposite, which structurally ensures the leveling accuracy of the platform leveling system. When the piston rod of the second luffing oil cylinder 52 extends, the piston rod of the second leveling oil cylinder 42 retracts. Of course, the eighth hinge point H can also be arranged on the inner side of the seventh hinge point G, that is, the third leveling oil cylinder 43 and the second luffing oil cylinder 52 are arranged on the same side of the turntable 1.

[0064] In some embodiments, with reference to Figure 5 and Figure 6As shown, the leveling loop further comprises a reversing valve 81 and a holding valve 82, the reversing valve 81 is connected with the third leveling oil cylinder 43 through the holding valve 82, the holding valve 82 comprises a double hydraulic control check valve and a relief valve, the relief valve is connected with the double hydraulic control check valve, and two oil outlets of the double hydraulic control check valve are connected with the rod cavity and the rodless cavity of the third leveling oil cylinder 43 one by one. Thus, the oil circuit formed by the first leveling oil cylinder 41, the second leveling oil cylinder 42 and the third leveling oil cylinder 43 in parallel is a closed oil circuit. The oil in the closed oil circuit cannot flow from the holding valve 82 to the reversing valve 81 before reaching a certain pressure. The oil in the closed oil circuit connecting the rod cavities of the first leveling oil cylinder 41, the second leveling oil cylinder 42 and the third leveling oil cylinder 43 flows in the closed oil circuit. The oil in the closed oil circuit connecting the rodless cavities of the first leveling oil cylinder 41, the second leveling oil cylinder 42 and the third leveling oil cylinder 43 flows in the closed oil circuit. When the oil in the closed oil circuit formed by the first leveling oil cylinder 41, the second leveling oil cylinder 42 and the third leveling oil cylinder 43 in parallel decreases, the reversing valve 81 can be controlled to reverse to supplement the oil in the oil circuit of the rodless cavity or the rod cavity of the first leveling oil cylinder 41, the second leveling oil cylinder 42 and the third leveling oil cylinder 43.

[0065] Further, a third balance valve 83 can be arranged between the first leveling oil cylinder 41 and the second leveling oil cylinder 42 to enable the working platform 2 to be stably stopped at a required adjustment position.

[0066] In some embodiments, the first luffing oil cylinder 51 is used to drive the first arm support 31 to perform luffing movement, and the second luffing oil cylinder 52 is used to drive the second arm support 32 to perform luffing movement. The first luffing oil cylinder 51 and the second luffing oil cylinder 52 are respectively connected with one working link of the multi-way valve 6, and the working link comprises a main valve, and the first luffing oil cylinder 51 or the second luffing oil cylinder 52 performs corresponding action by reversing control of the main valve. The inlet port P of the multi-way valve 6 is connected with a one-way cut-off reversing valve 79, and the one-way cut-off reversing valve 79 is connected with an inlet oil circuit. Specifically, the one-way cut-off reversing valve 79 can be a two-position two-way one-way cut-off electromagnetic valve.

[0067] In some embodiments, as shown in Figure 5 and Figure 6 , a first balance valve 77 is arranged between the first luffing oil cylinder 51 and the multi-way valve 6 to enable the first arm support 31 to be stably stopped at a required adjustment position, and a second balance valve 78 is arranged between the second luffing oil cylinder 52 and the multi-way valve 6 to enable the second arm support 32 to be stably stopped at a required adjustment position.

[0068] A safety limiting oil circuit can be arranged on the hydraulic circuit to directly guarantee the leveling safety of the working platform from the hydraulic system level.

[0069] As shown in Figure 4As shown, when the first arm support 31 and the second arm support 32 are both in the amplitude lifting state, in order to prevent the leveling angle of the working platform 2 from exceeding the safe range, the second arm cannot be lowered in amplitude at this time, and for this purpose, a second arm support amplitude safety limiting oil circuit can be arranged between the rod cavity of the second amplitude cylinder 52 and the rodless cavity of the second amplitude cylinder 52 to limit the amplitude lowering of the second amplitude cylinder 52.

[0070] In some embodiments, with reference to Figure 5 As shown, the second arm support amplitude safety limiting oil circuit includes a first limiting oil circuit connected between the rod cavity of the second amplitude cylinder 52 and the rodless cavity thereof, and a first motorized reversing valve 71 and a first check valve 72 are arranged on the first limiting oil circuit, with reference to Figure 3 As shown, the control end of the motorized reversing valve 71 is arranged relative to the first arm support 31, so that when the first arm support 31 is raised to a certain position, the control end of the motorized reversing valve 71 is touched, the motorized reversing valve 71 is reversed, the oil in the rod cavity of the second amplitude cylinder 52 flows in one direction through the first check valve 72 to the oil circuit connected to the rodless cavity of the second amplitude cylinder 52, and then flows back to the tank through the main valve in the corresponding working link in the multi-way valve 6, unloads the oil circuit on the rod cavity side of the second amplitude cylinder 52, and cannot form enough hydraulic pressure to push the piston rod of the second amplitude cylinder 52 to retract, i.e., the second arm support 32 cannot be lowered in amplitude. The purpose of limiting the amplitude angle of the second arm support 32 is achieved, thereby preventing the first arm support 31 from tilting backward due to misoperation.

[0071] Alternatively, with reference to Figure 6 As shown, the second arm support amplitude safety limiting oil circuit also includes a second limiting oil circuit connected between the rod cavity of the second amplitude cylinder 52 and the rodless cavity thereof, and a first electromagnetic reversing valve 73 and a second check valve 74 are arranged on the second limiting oil circuit, and a corresponding angle sensor or travel switch element for detecting the amplitude state of the first arm support 31 is arranged at the corresponding position of the first arm support 31, and the controller detects the angle signal or the arm support amplitude position, and when the first arm support 31 is raised to a certain position, the first electromagnetic reversing valve 73 is controlled to reverse, the oil in the rod cavity of the second amplitude cylinder 52 flows in one direction through the second check valve 74 to the oil circuit connected to the rodless cavity of the second amplitude cylinder 52, and then flows back to the tank through the main valve in the corresponding working link in the multi-way valve 6, unloads the oil circuit on the rod cavity side of the second amplitude cylinder 52, and cannot form enough hydraulic pressure to push the second arm support 32 to retract, i.e., the second arm support 32 cannot be lowered in amplitude. The purpose of limiting the amplitude angle of the second arm support 32 is achieved, thereby preventing the first arm support 31 from tilting backward due to misoperation.

[0072] Alternatively, with reference to Figure 6As shown, the first limiting oil path and the second limiting oil path can also be arranged between the rod cavity of the second amplitude cylinder 52 and its rodless cavity to improve the system working safety.

[0073] With reference to Figure 3 As shown, in the case of no action of the second amplitude cylinder 52, in order to prevent excessive upward tilt after exceeding the angle adjustable range of the working platform 2, the amplitude angle of the first arm support 31 also needs to be limited, that is, Figure 3 ∠a in the above formula needs to be limited to a safety value, and a first arm support amplitude safety limiting oil path can be arranged between the rod cavity of the first amplitude cylinder 51 and the rodless cavity of the first amplitude cylinder 51. Wherein, ∠a is the relative angle between the first arm support 31 and the second arm support 32.

[0074] In some embodiments, the first arm support amplitude safety limiting oil path is provided with a second electromagnetic reversing valve 75 and a third one-way valve 76. When the first arm support 31 is raised to a certain position, the second electromagnetic reversing valve 75 is controlled to reverse, so that the oil in the rodless cavity of the first amplitude cylinder 51 flows to the oil path connected to the rod cavity of the first amplitude cylinder 51 through the third one-way valve 76 in a single direction, and then flows back to the oil tank through the main valve in the corresponding working joint in the multi-way valve 6, thereby unloading the oil path on the rodless cavity side of the first amplitude cylinder 51, and not enough hydraulic pressure can be formed to push the piston rod of the first amplitude cylinder 51 to extend, that is, the first arm support 31 cannot continue to rise.

[0075] In order to better understand the technical concept of the present application, the following will be described in combination with relatively comprehensive technical features.

[0076] As Figures 1 to 6The present application discloses a platform leveling system, which comprises a rotary table 1, an arm support assembly, a working platform 2 leveling loop, a first luffing oil cylinder 51 and a second luffing oil cylinder 52. The arm support assembly comprises a first arm support 31 and a second arm support 32. The leveling loop comprises a first leveling oil cylinder 41, a second leveling oil cylinder 42, a third leveling oil cylinder 43, a reversing valve 81, a holding valve 82 and a third balance valve 83. The rod cavity of the first leveling oil cylinder 41, the rod cavity of the second leveling oil cylinder 42 and the rod cavity of the third leveling oil cylinder 43 are connected. The non-rod cavity of the first leveling oil cylinder 41, the non-rod cavity of the second leveling oil cylinder 42 and the non-rod cavity of the third leveling oil cylinder 43 are connected. The third leveling oil cylinder 43 is connected with the holding valve 82, so that the first leveling oil cylinder 41, the second leveling oil cylinder 42 and the third leveling oil cylinder 43 are connected in parallel to form a closed oil circuit. The holding valve 82 is connected with the reversing valve 81. The reversing valve 81 can be an electromagnetic reversing valve. The third balance valve 83 is installed between the first leveling oil cylinder 41 and the second leveling oil cylinder 42. The first end of the first arm support 31 is hinged with the working platform 2 through a first hinge point A. The first end of the first leveling oil cylinder 41 is hinged with the working platform 2 through a second hinge point B. The second end of the first leveling oil cylinder 41 is hinged with the first end of the first arm support 31 through a third hinge point C. The second end of the first arm support 31 is hinged with the first end of the second arm support 32 through a fourth hinge point D. The first end of the second leveling oil cylinder 42 is hinged with the second end of the first arm support 31 through a fifth hinge point E. The second end of the second leveling oil cylinder 42 is hinged with the first end of the second arm support 32 through a sixth hinge point F. The second end of the second arm support 32 is hinged with the rotary table 1 through a seventh hinge point G. The first end of the third leveling oil cylinder 43 is hinged with the second end of the second arm support 32 through an eighth hinge point H. The second end of the third leveling oil cylinder 43 is hinged with the rotary table 1 through a ninth hinge point I. When the first leveling oil cylinder 41, the second leveling oil cylinder 42 and the third leveling oil cylinder 43 are all in the fully extended or fully retracted state, the triangle formed by the first hinge point A, the second hinge point B and the third hinge point C, the triangle formed by the fourth hinge point D, the fifth hinge point E and the sixth hinge point F and the triangle formed by the seventh hinge point G, the eighth hinge point H and the ninth hinge point I are all congruent. The first luffing oil cylinder 51 is installed between the first arm support 31 and the second arm support 32 and is used for driving the first arm support 31 to perform luffing movement. The second luffing oil cylinder 52 is installed between the second arm support 32 and the rotary table 1 and is used for driving the second arm support 32 to perform luffing movement. The second luffing oil cylinder 52 and the third leveling oil cylinder 43 are located on opposite sides of the rotary table 1, i.e. the eighth hinge point H is arranged outside the seventh hinge point G. A first balance valve 77 is arranged between the first luffing oil cylinder 51 and a multi-way valve 6. A second balance valve 78 is arranged between the second luffing oil cylinder 52 and the multi-way valve 6. A one-way stop reversing valve 79 is installed between an oil inlet P of the multi-way valve 6 and an oil inlet oil circuit. An oil return port T of the multi-way valve 6 is connected with an oil return oil circuit.A second boom luffing safety limiting oil circuit is provided between the rod chamber and the rodless chamber of the second luffing cylinder 52. The second boom luffing safety limiting oil circuit includes a first limiting oil circuit, which connects the rod chamber and the rodless chamber of the second luffing cylinder 52. The first limiting oil circuit is equipped with a motorized reversing valve 71 and a first check valve 72. When the motorized reversing valve 71 reverses the direction of the oil circuit, the oil in the rod chamber of the second luffing cylinder 52 can flow unidirectionally to the oil circuit connected to the rodless chamber of the second luffing cylinder 52 through the first check valve 72, unloading the oil circuit on the rod chamber side of the second luffing cylinder 52. This prevents the formation of sufficient hydraulic pressure to push the piston rod of the second luffing cylinder 52 to retract, meaning that the second boom 32 cannot luff downwards.

[0077] Among them, the dimensions and parameters of the first leveling cylinder 41, the second leveling cylinder 42 and the third leveling cylinder 43 are exactly the same. Moreover, the parameters of each cylinder in the leveling circuit and the pressure parameters of the holding valve 82 are set to ensure that the output force of the first leveling cylinder 41, the second leveling cylinder 42 and the third leveling cylinder 43 is insufficient to drive the boom to move. That is, the first leveling cylinder 41, the second leveling cylinder 42 and the third leveling cylinder 43 cooperate with each other to level the angle of the working platform 2.

[0078] The working process of the platform leveling system of the present invention is as follows:

[0079] 1. Manual leveling

[0080] When manually leveling, refer to Figure 5 When the one-way shut-off directional valve 79 is energized, it prevents oil from flowing into the multi-way valve 6 and prevents oil from being depressurized from the multi-way valve 6.

[0081] When the left control terminal of the reversing valve 81 is energized, the left position function of the reversing valve 81 is activated, the oil flows through the holding valve 82, and through the rodless chamber of the third leveling cylinder 43 and the rodless chamber of the second leveling cylinder 42, and flows into the rodless chamber of the first leveling cylinder 41. The piston rod of the first leveling cylinder 41 extends, causing the working platform 2 to tilt upward.

[0082] When the right control terminal of the reversing valve 81 is energized, the right position function of the reversing valve 81 is activated, the oil flows through the holding valve 82, and through the rod chamber of the third leveling cylinder 43 and the rod chamber of the second leveling cylinder 42, and flows into the rod chamber of the first leveling cylinder 41. The piston rod of the first leveling cylinder 41 retracts, causing the working platform 2 to tilt downward.

[0083] Manual leveling is typically used for setting the initial angle of the work platform 2 or eliminating angle errors.

[0084] II. Automatic Leveling

[0085] Automatic leveling refers to that when the first arm frame 31 and the second arm frame 32 are in action (independent action or compound action), the platform leveling system of the present application automatically adjusts the angle of the working platform 2 in the opposite direction according to the action direction of each arm frame to ensure that the working platform 2 is always in a horizontal state parallel to the ground.

[0086] Figure 1 The working condition of the platform leveling system in the initial state is shown, and the working platform 2 is manually adjusted to be horizontal. At this time, the first luffing oil cylinder 51 and the second luffing oil cylinder 52 are retracted, the third leveling oil cylinder 43 is fully extended, the second leveling oil cylinder 42 is fully retracted, and the first leveling oil cylinder 41 is partially extended.

[0087] Figure 3 The working condition of the first arm frame 31 luffing and lifting and the second arm frame 32 remaining stationary is shown. At this time, the second luffing oil cylinder 52 and the third leveling oil cylinder 43 are not in action. In this working condition, in order to prevent excessive upward tilt after exceeding the adjustable range of the angle of the working platform, the luffing angle of the first arm frame 31 needs to be limited, that is, the relative angle ∠a between the first arm frame 31 and the second arm frame 32 needs to be limited to a safe value.

[0088] When the piston rod of the first luffing oil cylinder 51 is extended to drive the first arm frame 31 to luff and lift, the working platform 2 is tilted upward, and at the same time, the first arm frame 31 drives the second leveling oil cylinder 42 to extend. The oil in the rod cavity of the second leveling oil cylinder 42 flows into the rod cavity of the first leveling oil cylinder 41, and the first leveling oil cylinder 41 is retracted, driving the working platform 2 to tilt downward. In this process, the oil in the rodless cavity of the first leveling oil cylinder 41 flows into the rodless cavity of the second leveling oil cylinder 42, and the length of the extension of the second leveling oil cylinder 42 is equal to the length of the retraction of the first leveling oil cylinder 41, so that the angle of the working platform 2 is adjusted in the opposite direction with the first arm frame 31 at approximately the same angle, thereby keeping the working platform 2 horizontal with the ground.

[0089] Similarly, when the piston rod of the first luffing oil cylinder 51 is retracted to drive the first arm frame 31 to luff and descend, the working platform 2 is tilted downward, and at the same time, the first arm frame 31 drives the second leveling oil cylinder 42 to retract. The oil in the rodless cavity of the second leveling oil cylinder 42 flows into the rodless cavity of the first leveling oil cylinder 41, and the first leveling oil cylinder 41 is extended, driving the working platform 2 to tilt upward. In this process, the oil in the rod cavity of the first leveling oil cylinder 41 flows into the rod cavity of the second leveling oil cylinder 42, and the length of the retraction of the second leveling oil cylinder 42 is equal to the length of the extension of the first leveling oil cylinder 41, so that the angle of the working platform 2 is adjusted in the opposite direction with the first arm frame 31 at approximately the same angle, thereby keeping the working platform 2 horizontal with the ground.

[0090] Figure 2 The working condition of the first arm frame 31 remaining stationary and the second arm frame 32 luffing and lifting is shown. At this time, the first luffing oil cylinder 51 and the second leveling oil cylinder 42 are not in action.

[0091] When the piston rod of the second amplitude cylinder 52 extends to drive the second arm frame 32 to amplitude rise, it drives the work platform 2 to incline downward, at the same time, the second arm frame 32 drives the third leveling cylinder 43 to retract, the oil in the rodless cavity of the third leveling cylinder 43 flows into the rodless cavity of the first leveling cylinder 41, so that the first leveling cylinder 41 extends, and drives the work platform 2 to incline upward. In this process, the oil in the rodless cavity of the third leveling cylinder 43 flows into the rodless cavity of the first leveling cylinder 41, and the length of the third leveling cylinder 43 retraction is equal to the length of the first leveling cylinder 41 extension, so that the angle of the work platform 2 and the second arm frame 32 are adjusted in approximately equal angle and opposite direction, so as to realize the work platform 2 and the ground to keep horizontal.

[0092] Similarly, when the piston rod of the second amplitude cylinder 52 extends to drive the second arm frame 32 to amplitude drop, it drives the work platform 2 to incline upward, at the same time, the second arm frame 32 drives the third leveling cylinder 43 to extend, the oil in the rod cavity of the third leveling cylinder 43 flows into the rod cavity of the first leveling cylinder 41, so that the first leveling cylinder 41 retracts, and drives the work platform 2 to incline downward. In this process, the oil in the rod cavity of the third leveling cylinder 43 flows into the rod cavity of the first leveling cylinder 41, and the length of the third leveling cylinder 43 extension is equal to the length of the first leveling cylinder 41 retraction, so that the angle of the work platform 2 and the second arm frame 32 are adjusted in approximately equal angle and opposite direction, so as to realize the work platform 2 and the ground to keep horizontal.

[0093] Figure 4 The working conditions of the amplitude action of the first arm frame 31 and the second arm frame 32 are shown, in order to prevent the leveling angle of the work platform 2 from exceeding the safe range, it is necessary to limit the amplitude drop of the second amplitude cylinder 52 when the first amplitude cylinder 51 is amplitude to a certain angle.

[0094] Referring to Figure 4 It is shown that if ∠a=κ∠b is set, κ takes value according to arm frame structure, hinge point position and design operation range, which can be 1 / 2, 2 / 3 or other values.

[0095] Referring to Figure 5 It is shown that the motorized reversing valve 71 is arranged at a position which can contact with the first amplitude cylinder 51, and the value of ∠a is set by setting the installation position of the motorized reversing valve 71, when the amplitude angle of the first amplitude cylinder 51 is greater than ∠a, the descending action of the second amplitude cylinder 52 is limited, but the amplitude rise of the second arm frame 32 is allowed.

[0096] The first arm frame 31 is amplitude to ∠b, and the second arm frame 32 is amplitude to ∠c, since ∠b is greater than ∠a, at this time, the first arm frame 31 touches the motorized reversing valve 71, so that the second arm frame 32 cannot amplitude drop.

[0097] When the second arm 32 is limited in amplitude, the motor reversing valve 71 is opened when the first arm 31 reaches the preset safety angle ∠a, and the oil in the rod cavity of the second amplitude cylinder 52 will flow back to the tank through the first check valve 72, the motor reversing valve 71, the rod cavity side oil way of the second amplitude cylinder 52, and the multi-way valve 6. In this case, the rod cavity side oil way of the second amplitude cylinder 52 is unloaded, and insufficient hydraulic pressure is formed to push the second amplitude cylinder 52 to retract, that is, the second arm 32 cannot be lowered in amplitude, so that the purpose of limiting the amplitude angle of the second arm 32 is achieved, thereby preventing the first arm 31 from tilting backward due to misoperation. When the second arm 32 is raised in amplitude, the motor reversing valve 71 is also in the open state, but due to the blocking effect of the first check valve 72, the oil flows to the rod cavity of the second amplitude cylinder 52, and the second arm 32 normally performs the lifting action.

[0098] The first leveling cylinder 41, the second leveling cylinder 42, and the third leveling cylinder 43 are completely identical in size and parameters, and are connected in parallel, with the rod cavity connected to the rod cavity and the rod cavity connected to the rod cavity, so that the change amount of the extension and retraction length of the first leveling cylinder 41, the second leveling cylinder 42, and the third leveling cylinder 43 is completely equal when they are linked, thereby ensuring that the leveling angle of the working platform 2 accurately matches the amplitude change of the arm.

[0099] Furthermore, the first end of the third leveling cylinder 43 is hinged to the second end of the second arm 32 to form an eighth hinge point H located at the tail end of the second arm 32, so that the movement direction of the piston rod of the third leveling cylinder 43 is opposite to that of the piston rod of the first leveling cylinder 41 when the working platform 2 is leveled, thereby structurally ensuring the accuracy of the platform leveling system.

[0100] The arm amplitude safety limiting oil way is provided on the hydraulic circuit, thereby directly ensuring the safety of the working platform 2 from the hydraulic system level, and the oil way is simple in structure and has few components, thereby having higher reliability compared with an electric control safety protection system, and being more meaningful for the safety of a manned working platform.

[0101] On the basis of the technical scheme of the platform leveling system of the present application, the present application further provides a high-altitude work platform, which comprises the platform leveling system of any one of the technical schemes.

[0102] On the basis of the technical scheme of the high-altitude work platform of the present application, the present application further provides a high-altitude work machine, which comprises the high-altitude work platform of any one of the technical schemes.

[0103] The preferred embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the specific details of the above-described embodiments. Various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0104] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, various possible combinations are not described again by the present application.

[0105] In addition, various different embodiments of the present application can also be combined in any appropriate manner, as long as they do not deviate from the idea of the present application, and they should also be considered as disclosed by the present application.

Claims

1. A platform levelling system, characterised in that, The application relates to a rotary table (1), an arm support assembly, a working platform (2) and a leveling loop, the arm support assembly comprising a first arm support (31) and a second arm support (32) hingedly connected, the first arm support (31) being hingedly connected with the working platform (2), the second arm support (32) being hingedly connected with the rotary table (1), the leveling loop comprising a first leveling oil cylinder (41), a second leveling oil cylinder (42) and a third leveling oil cylinder (43), the first leveling oil cylinder (41) being hingedly connected at both ends with the first arm support (31) and the working platform (2), the second leveling oil cylinder (42) being hingedly connected at both ends with the first arm support (31) and the second arm support (32), the third leveling oil cylinder (43) being hingedly connected at both ends with the second arm support (32) and the rotary table (1), the three leveling oil cylinders (41, 42 and 43) having rod cavities connected to form a closed oil circuit and having non-rod cavities connected to form a closed oil circuit, and the three leveling oil cylinders (41, 42 and 43) having the same specifications. The first end of the first arm support (31) is hingedly connected with the working platform (2) through a first hinge point (A), the first end of the first leveling oil cylinder (41) is hingedly connected with the working platform (2) through a second hinge point (B), the second end of the first leveling oil cylinder (41) is hingedly connected with the first end of the first arm support (31) through a third hinge point (C), the second end of the first arm support (31) is hingedly connected with the first end of the second arm support (32) through a fourth hinge point (D), the first end of the second leveling oil cylinder (42) is hingedly connected with the second end of the first arm support (31) through a fifth hinge point (E), the second end of the second leveling oil cylinder (42) is hingedly connected with the first end of the second arm support (32) through a sixth hinge point (F), the second end of the second arm support (32) is hingedly connected with the rotary table (1) through a seventh hinge point (G), and the first end of the third leveling oil cylinder (43) is hingedly connected with the second end of the second arm support (32) through an eighth hinge point (H), and the second end of the third leveling oil cylinder (43) is hingedly connected with the rotary table (1) through a ninth hinge point (I). When the first leveling oil cylinder (41), the second leveling oil cylinder (42) and the third leveling oil cylinder (43) are all in the fully extended or fully retracted state, the triangle formed by the first hinge point (A), the second hinge point (B) and the third hinge point (C), the triangle formed by the fourth hinge point (D), the fifth hinge point (E) and the sixth hinge point (F), and the triangle formed by the seventh hinge point (G), the eighth hinge point (H) and the ninth hinge point (I) are all congruent. The seventh hinge point (G) is located between the fourth hinge point (D) and the eighth hinge point (H).

2. The platform leveling system of claim 1, wherein, A first luffing oil cylinder (51) is installed between the first boom (31) and the second boom (32), and a second luffing oil cylinder (52) is installed between the second boom (32) and the rotary table (1), both of which are connected with the multi-way valve (6), and a second boom luffing safety limiting oil circuit is arranged between the rod cavity and the non-rod cavity of the second luffing oil cylinder (52).

3. The platform leveling system of claim 2, wherein, The second boom luffing safety limiting oil circuit comprises a first limiting oil circuit connected between the rod cavity and the non-rod cavity of the second luffing oil cylinder (52), and a motorized reversing valve (71) and a first check valve (72) capable of unidirectionally guiding the oil in the rod cavity of the second luffing oil cylinder (52) to the oil circuit connected with the non-rod cavity are arranged on the first limiting oil circuit, and the control end of the motorized reversing valve (71) is arranged relative to the first boom (31).

4. A levelling system according to claim 2 or 3, wherein, The second boom luffing safety limiting oil circuit comprises a second limiting oil circuit connected between the rod cavity and the non-rod cavity of the second luffing oil cylinder (52), and a first electromagnetic reversing valve (73) and a second check valve (74) capable of unidirectionally guiding the oil in the rod cavity of the second luffing oil cylinder (52) to the oil circuit connected with the non-rod cavity are arranged on the second limiting oil circuit.

5. The platform leveling system of claim 2 or 3, wherein, A first boom luffing safety limiting oil circuit is arranged between the rod cavity and the non-rod cavity of the first luffing oil cylinder (51).

6. The platform leveling system of claim 5, wherein, A second electromagnetic reversing valve (75) and a third check valve (76) capable of unidirectionally guiding the oil in the non-rod cavity of the first luffing oil cylinder (51) to the rod cavity are arranged on the first boom luffing safety limiting oil circuit.

7. The platform leveling system of claim 2 or 3, wherein, A first balance valve (77) is arranged between the first luffing oil cylinder (51) and the multi-way valve (6), and a second balance valve (78) is arranged between the second luffing oil cylinder (52) and the multi-way valve (6).

8. The platform leveling system of claim 2 or 3, wherein, A one-way cut-off reversing valve (79) is connected with the oil inlet of the multi-way valve (6).

9. The platform leveling system of any one of claims 1-3, wherein, The leveling circuit further comprises a reversing valve (81) and a holding valve (82), and the reversing valve (81) is connected with the third leveling oil cylinder (43) through the holding valve (82).

10. The platform leveling system of any one of claims 1-3, wherein, A third balance valve (83) is arranged between the first leveling oil cylinder (41) and the second leveling oil cylinder (42).

11. An aerial work platform, characterized by The platform leveling system of any one of claims 1 to 10 is arranged.

12. An aerial work platform, characterized in that The aerial work platform of claim 11 is arranged.

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