A hydraulic drive system for excavator boom

Abstract

The invention relates to a hydraulic drive system for an excavator boom, belonging to the technical field of hydraulics of excavators, and comprising: a base, a boom and a forearm which are hinged in sequence, and further comprising a main hydraulic cylinder and an auxiliary hydraulic cylinder, wherein one end of the main hydraulic cylinder is hinged to the top of the boom, the main hydraulic cylinder comprises a first hydraulic cylinder and a third hydraulic cylinder, the other end of the first hydraulic cylinder is hinged to the base, and the other end of the third hydraulic cylinder is hinged to the top of the forearm; one end of the auxiliary hydraulic cylinder is hinged to the bottom of the boom, the auxiliary hydraulic cylinder comprises a second hydraulic cylinder and a fourth hydraulic cylinder, the other end of the second hydraulic cylinder is hinged to the base, and the other end of the fourth hydraulic cylinder is hinged to the bottom of the forearm; the system can solve the technical problem of low safety caused by single-sided hydraulic cylinder driving in the prior art, when the hydraulic system leaks, the hydraulic cylinder loses pressure, causing the boom to fall by its own weight.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydraulic pressure of excavators, and in particular relates to a hydraulic drive system for an excavator boom. Background Art

[0002] The excavator boom is an extremely important component of the excavator. With the help of the telescopic action of the hydraulic cylinder connected to it, the boom can control a variety of actions. Therefore, the efficiency and safety of the hydraulic drive system are particularly important for the excavator boom.

[0003] The existing patent application number CN202410197420.7 discloses a hydraulic excavator energy-saving system. The hydraulic excavator energy-saving system also includes an anti-settling valve. The anti-settling valve is arranged at the large cavity outlet of the boom cylinder and is respectively connected to the flow extraction valve and the main valve boom link. When the hydraulic excavator is in a non-boom lowering working condition, the main valve boom is in the middle position and the anti-settling valve is locked. At this time, the boom is locked to prevent the boom from falling due to its own weight.

[0004] The existing technology has the following problems:

[0005] The boom and arm of existing excavator booms are mostly driven by single-sided hydraulic cylinders. Even if the anti-settling valve is locked, if the hydraulic system leaks due to other reasons, the hydraulic cylinder will still lose pressure and cause the boom to fall due to its own weight, which reduces safety. Summary of the Invention

[0006] The present invention provides a hydraulic drive system for an excavator boom, which can solve the technical problem of low safety in the prior art of single-sided hydraulic cylinder drive, in which when the hydraulic system leaks, the hydraulic cylinder loses pressure, causing the boom to fall under its own weight.

[0007] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0008] The present application provides a hydraulic drive system for an excavator boom, comprising a base, an upper arm and a lower arm hinged in sequence, and further comprising a main hydraulic cylinder and an auxiliary hydraulic cylinder, wherein one end of the main hydraulic cylinder is hinged to the upper part of the upper arm, and the main hydraulic cylinder has a first hydraulic cylinder and a third hydraulic cylinder, the other end of the first hydraulic cylinder is hinged to the base, and the other end of the third hydraulic cylinder is hinged to the upper part of the lower arm; one end of the auxiliary hydraulic cylinder is hinged to the lower part of the upper arm, and the auxiliary hydraulic cylinder has a second hydraulic cylinder and a fourth hydraulic cylinder, the other end of the second hydraulic cylinder is hinged to the base, and the other end of the fourth hydraulic cylinder is hinged to the lower part of the lower arm.

[0009] Through the above technical solution, the main hydraulic cylinder and auxiliary hydraulic cylinder are arranged up and down, which can prevent the boom from falling due to its own weight when a single cylinder leaks, thereby improving the safety of the excavator boom.

[0010] In the present invention, the above-mentioned main liquid cylinder has a main retraction chamber and a main extension chamber, and the auxiliary liquid cylinder has an auxiliary retraction chamber and an auxiliary extension chamber. A driven liquid circuit is connected between the main retraction chamber and the auxiliary retraction chamber, and a driving liquid circuit is connected between the main extension chamber and the auxiliary extension chamber. The driving liquid circuit is connected to a variable pump and a reversing valve.

[0011] Through the above technical solution, the hydraulic circuits of the main hydraulic cylinder and the auxiliary hydraulic cylinder are interconnected. When the boom moves in the opposite direction, the hydraulic oil discharged from one of the hydraulic cylinders can be used as the driving force for the other hydraulic cylinder, avoiding energy conversion through accumulators and the like, thereby avoiding energy loss and improving the energy utilization efficiency when the boom is reversing.

[0012] In the present invention, the hydraulic drive system of the excavator boom also includes a first safety valve and a second safety valve. The first safety valve is connected to the auxiliary fluid cylinder, and the first safety valve controls the auxiliary fluid cylinder to connect or disconnect the fluid circuit based on the pressure of the driven fluid circuit; the second safety valve is connected to the master fluid cylinder, and the second safety valve controls the master fluid cylinder to connect or disconnect the fluid circuit based on the pressure in the pipeline between the reversing valve and the auxiliary fluid cylinder.

[0013] Through the above technical solution, the first safety valve and the second safety valve are used. When leakage and pressure loss occur in the driven hydraulic circuit or the driving hydraulic circuit, the main hydraulic cylinder or the auxiliary hydraulic cylinder can be disconnected and the pressure can be maintained, thereby maintaining the posture of the boom, avoiding continued use after the hydraulic system leaks and causing safety accidents.

[0014] In the present invention, the hydraulic drive system for the excavator boom further includes a buffer tube. A plurality of buffer tubes are connected to the driven fluid circuit and the driving fluid circuit. The buffer tubes expand as the pressure of the driven fluid circuit or the driving fluid circuit increases.

[0015] Through the above technical solution, a buffer tube is used to absorb the instantaneous potential energy generated in the reverse direction of the liquid path, thereby causing elastic deformation, and then converting the elastic potential energy into the potential energy of the hydraulic oil when recovering the deformation, thereby reducing the friction between the hydraulic oil and the pipe wall when reversing, thereby reducing the energy loss caused by heat.

[0016] In the present invention, the inner wall of the buffer tube is coated with a PTFE coating.

[0017] Through the above technical solution, the use of PTFE coating further reduces the friction between the buffer tube and the hydraulic oil, thereby improving the efficiency of the hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A structural isometric diagram of a hydraulic drive system for an excavator boom provided by an embodiment of the present invention;

[0020] Figure 2 A structural side view of a hydraulic drive system for an excavator boom provided by an embodiment of the present invention;

[0021] Figure 3 A hydraulic schematic diagram of a hydraulic drive system for an excavator boom provided in an embodiment of the present invention.

[0022] Icons: 1-base; 101-first hydraulic cylinder; 102-second hydraulic cylinder; 2-upper arm; 201-third hydraulic cylinder; 202-fourth hydraulic cylinder; 3-small arm; 301-fifth hydraulic cylinder; 401-main hydraulic cylinder; 402-auxiliary hydraulic cylinder; 403-reversing valve; 404-variable pump; 405-first safety valve; 406-second safety valve; 407-first pressure relief valve; 408-fluid replenishing pump; 409-second pressure relief valve; 410-oil cylinder; 411-buffer pipe; 412-driven hydraulic circuit; 413-driving hydraulic circuit. DETAILED DESCRIPTION

[0023] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0024] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0025] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0026] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installation," "connection," and "connection" should be understood in a broad sense. For example, they can refer to welding, bolting, or riveting; fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0027] Example:

[0028] Please refer to Figures 1 to 3 , Figures 1 to 3 An embodiment of the present application is shown.

[0029] This embodiment provides a hydraulic drive system for an excavator boom, such as Figure 1 As shown, it includes a base 1, a large arm 2 and a small arm 3 which are hinged in sequence, as shown in FIG. Figure 2 As shown, it also includes a main liquid cylinder 401 and an auxiliary liquid cylinder 402. One end of the main liquid cylinder 401 is hinged to the top of the upper arm 2. The main liquid cylinder 401 has a first liquid cylinder 101 and a third liquid cylinder 201. The other end of the first liquid cylinder 101 is hinged to the base 1, and the other end of the third liquid cylinder 201 is hinged to the top of the small arm 3; one end of the auxiliary liquid cylinder 402 is hinged to the bottom of the upper arm 2. The auxiliary liquid cylinder 402 has a second liquid cylinder 102 and a fourth liquid cylinder 202. The other end of the second liquid cylinder 102 is hinged to the base 1, and the other end of the fourth liquid cylinder 202 is hinged to the bottom of the small arm 3.

[0030] When in use, the base 1 is connected to the excavator body, and then the main hydraulic cylinder 401 is extended and the auxiliary hydraulic cylinder 402 is retracted to achieve the lowering and recovery of the boom.

[0031] Unlike the layout of setting driving cylinders on both sides which can only provide stronger driving force, the main cylinder 401 and the auxiliary cylinder 402 are respectively set on the upper and lower sides of the boom, which can still provide a more balanced support effect after a single-side cylinder leaks, thereby avoiding tilting.

[0032] Through the above technical solution, the main hydraulic cylinder 401 and the auxiliary hydraulic cylinder 402 are arranged up and down, which can prevent the boom from falling due to its own weight when a single oil cylinder 410 leaks, thereby improving the safety of the excavator boom.

[0033] As a better implementation method, Figure 3As shown, the above-mentioned main liquid cylinder 401 has a main retraction chamber and a main extension chamber, and the auxiliary liquid cylinder 402 has an auxiliary retraction chamber and an auxiliary extension chamber. The main retraction chamber and the auxiliary retraction chamber are connected by a driven liquid path 412, and the main extension chamber and the auxiliary extension chamber are connected by a driving liquid path 413. The driving liquid path 413 is connected to the variable pump 404 and the reversing valve 403.

[0034] like Figure 3 As shown, when in use, the variable pump 404 pumps the hydraulic oil in the main extension chamber of the main hydraulic cylinder 401 into the auxiliary extension chamber of the auxiliary hydraulic cylinder 402, thereby completing the retraction of the main hydraulic cylinder 401 and the extension of the auxiliary hydraulic cylinder 402, thereby allowing the boom to rise upward, and the push rod is used to drive the reversing valve 403 when changing direction.

[0035] It should be noted that if Figure 3 The figure shows a hydraulic diagram of a group of cylinders, such as the first cylinder 101 and the second cylinder 102 are a group, the third cylinder 201 and the fourth cylinder 202 are a group, and the two groups of hydraulics are controlled independently. Figure 2 As shown, the bucket is only independently connected to the fifth cylinder 301, and does not use Figure 3 Hydraulic diagram shown.

[0036] Through the above technical solution, the hydraulic circuits of the main hydraulic cylinder 401 and the auxiliary hydraulic cylinder 402 are interconnected. When the boom moves in the opposite direction, the hydraulic oil discharged from one of the hydraulic cylinders can be used as the driving force for the other hydraulic cylinder, avoiding energy conversion through accumulators and the like, thereby avoiding energy loss and improving the energy utilization efficiency when the boom is reversing.

[0037] As a better implementation method, Figure 3 As shown, the hydraulic drive system of the excavator boom also includes a first safety valve 405 and a second safety valve 406. The first safety valve 405 is connected to the auxiliary liquid cylinder 402, and the first safety valve 405 controls the auxiliary liquid cylinder 402 to connect or disconnect the liquid circuit based on the pressure of the driven liquid circuit 412; the second safety valve 406 is connected to the main liquid cylinder 401, and the second safety valve 406 controls the main liquid cylinder 401 to connect or disconnect the liquid circuit based on the pressure in the pipeline between the reversing valve 403 and the auxiliary liquid cylinder 402.

[0038] During use, two sets of safety valves are used to control the on-off of the liquid circuit according to the pressure in the driving liquid circuit 413 and the driven liquid circuit 412. When a certain section of the liquid circuit leaks and the hydraulic pressure is reduced, the safety valve pipe wall disconnects the main liquid cylinder 401 or the auxiliary liquid cylinder 402. The disconnected liquid cylinder can retain the hydraulic oil inside and obtain stable hydraulic support.

[0039] It should be noted that if Figure 3As shown, in order to avoid the loss of hydraulic oil when the variable pump 404 is working, a fluid replenishing pump 408 is also connected to the driving fluid circuit 413. The fluid replenishing pump 408 is connected to the fluid circuit through a one-way valve, and the front end of the fluid replenishing pump 408 is also connected to a second pressure relief valve 409 to prevent excessive pressure during fluid replenishment. The output end of the variable pump 404 is connected to the first pressure relief valve 407. The first pressure relief valve 407, the fluid replenishing pump 408 and the second pressure relief valve 409 are all connected to the oil cylinder 410.

[0040] Through the above technical solution, the first safety valve 405 and the second safety valve 406 are used. When leakage and pressure loss occur in the driven hydraulic circuit 412 or the driving hydraulic circuit 413, the main hydraulic cylinder 401 or the auxiliary hydraulic cylinder 402 can be disconnected and the pressure can be maintained, thereby maintaining the posture of the boom, avoiding continued use after the hydraulic system leaks and causing safety accidents.

[0041] As a preferred embodiment, the above-mentioned excavator boom hydraulic drive system also includes a buffer tube 411, and multiple buffer tubes 411 are connected to the driven fluid circuit 412 and the driving fluid circuit 413. The buffer tube 411 expands according to the increase in pressure of the driven fluid circuit 412 or the driving fluid circuit 413.

[0042] During use, when the pressurized hydraulic oil suddenly flows in the opposite direction in the pipeline, the buffer tube 411 will expand under the action of the impact force to absorb part of the energy brought by the reverse flow, so that the flow state of the hydraulic oil changes relatively smoothly. At the same time, because the diameter of the buffer tube 411 increases after expansion, according to the principles of fluid mechanics, when the local diameter of the pipeline increases, under the condition of unchanged flow rate (assuming that the overall flow rate can be approximately regarded as unchanged in a short time when the hydraulic oil flows in the opposite direction), the flow rate of the hydraulic oil will decrease, and the reduction in flow rate will reduce the friction coefficient between the hydraulic oil and the pipe wall, thereby reducing frictional resistance. When the flow state stabilizes, the buffer tube 411 contracts and converts the elastic potential energy into the flow potential energy of the hydraulic oil.

[0043] Through the above technical solution, the buffer tube 411 is used to absorb the instantaneous potential energy generated in the reverse direction of the liquid path, thereby causing elastic deformation, and then converting the elastic potential energy into the potential energy of the hydraulic oil when restoring the deformation, thereby reducing the friction between the hydraulic oil and the pipe wall when reversing, thereby reducing the energy loss caused by heat.

[0044] As a preferred embodiment, the inner wall of the buffer tube 411 is coated with a PTFE coating.

[0045] PTFE (polytetrafluoroethylene) has an extremely low friction coefficient, usually between 0.04-0.15. It is an excellent self-lubricating material. It can form a smooth lubricating film on the surface to reduce friction when in contact with other objects. At the same time, PTFE has good chemical stability and is resistant to corrosion such as acids and alkalis, and organic solvents. It can maintain its performance in a variety of harsh environments. It also has certain heat resistance and cold resistance, and is suitable for a wide temperature range.

[0046] During use, a PTFE coating is applied to the inner surface of the buffer tube 411 by spraying or dipping, which can not only maintain the elasticity of the buffer tube 411 itself, but also give it a self-lubricating effect, effectively reducing the friction with other components during use, and improving its service life and work efficiency.

[0047] Through the above technical solution, the use of PTFE coating further reduces the friction between the buffer tube 411 and the hydraulic oil, thereby improving the efficiency of the hydraulic system.

[0048] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope of the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A hydraulic drive system for an excavator boom, comprising a base (1), a boom (2) and a forearm (3) which are articulated in sequence, characterized in that: Also includes: A main liquid cylinder (401), one end of which is hinged to the upper part of the upper arm (2), the main liquid cylinder (401) comprising a first liquid cylinder (101) and a third liquid cylinder (201), the other end of the first liquid cylinder (101) being hinged to the base (1), and the other end of the third liquid cylinder (201) being hinged to the upper part of the lower arm (3); An auxiliary liquid cylinder (402), one end of which is hinged to the bottom of the upper arm (2), the auxiliary liquid cylinder (402) comprising a second liquid cylinder (102) and a fourth liquid cylinder (202), the other end of the second liquid cylinder (102) being hinged to the base (1), and the other end of the fourth liquid cylinder (202) being hinged to the bottom of the lower arm (3); The main liquid cylinder (401) has a main retraction chamber and a main extension chamber, the auxiliary liquid cylinder (402) has an auxiliary retraction chamber and an auxiliary extension chamber, a driven liquid path (412) is connected between the main retraction chamber and the auxiliary retraction chamber, a driving liquid path (413) is connected between the main extension chamber and the auxiliary extension chamber, and the driving liquid path (413) is connected to a variable pump (404) and a reversing valve (403); A first safety valve (405) connected to the auxiliary liquid cylinder (402), the first safety valve (405) controlling the auxiliary liquid cylinder (402) to connect or disconnect the liquid circuit based on the pressure of the driven liquid circuit (412); The second safety valve (406) is connected to the main liquid cylinder (401), and the second safety valve (406) controls the main liquid cylinder (401) to connect or disconnect the liquid circuit based on the pressure in the pipeline between the reversing valve (403) and the auxiliary liquid cylinder (402).

2. The hydraulic drive system for an excavator boom according to claim 1, characterized in that: Also includes: A plurality of buffer tubes (411) are connected to the driven fluid path (412) and the driving fluid path (413), and the buffer tubes (411) expand in response to an increase in pressure in the driven fluid path (412) or the driving fluid path (413).

3. The hydraulic drive system for an excavator boom according to claim 2, characterized in that: The inner wall of the buffer tube (411) is coated with a PTFE coating.

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