Miniature electro-hydraulic actuator

Abstract

The utility model discloses a miniature electro-hydraulic actuator which comprises an electro-hydraulic actuator body, a proportional electromagnet, two proportional pressure reducing valves, a cylinder body, a piston mechanism and a swing rod mechanism. A front end cover is arranged at the front end of the electro-hydraulic actuator body, a rear end cover is arranged at the rear end of the electro-hydraulic actuator body, the front end cover, the cylinder body and the piston mechanism form a closed front cavity, and the rear end cover, the cylinder body and the piston mechanism form a closed rear cavity; the front cavity and the rear cavity are respectively communicated with outlets of the two proportional pressure reducing valves; the proportional electromagnet generates corresponding thrust according to the magnitude of input current to push valve elements of the two proportional pressure reducing valves to move, pressure changing along with the current is generated at outlets of the two proportional pressure reducing valves, and the pressure enables the front cavity and the rear cavity to generate pressure so as to push the piston mechanism to be in linkage with the swing rod mechanism to move. Therefore, the opening degree or reversing of the manual multi-way valve is controlled. The device can be used for carrying out low-cost automatic or remote control transformation on engineering machinery and hydraulic equipment which take a manual multi-way valve as a main control valve.

Description

Technical Field

[0001] The utility model belongs to the technical field of electro-hydraulic actuators, in particular to a miniature electro-hydraulic actuator. Background Art

[0002] Many construction machinery and hydraulic equipment initially rely on manual multi-way valves as main control valves for cost considerations. These valves can only be operated manually. However, with increasing demands for equipment automation and operational safety, automated or remote control is becoming increasingly necessary. This necessitates the main control valves being able to operate via electrical signals.

[0003] Existing solutions for modifying hydraulic equipment using manual multi-way valves as main control valves primarily involve adding an electric push rod device connected to the manual multi-way valve handle. This approach utilizes gears or a lead screw to convert the rotational motion of a stepper motor into linear motion, driving the manual multi-way valve handle to reverse the valve direction, thereby enabling automated or remote control of the equipment. However, these electric push rod device modifications, limited by their drive method and transmission mechanism structure, result in a high failure rate, low reliability, and a short lifespan under harsh operating conditions. Utility Model Content

[0004] The following is a brief overview of embodiments of the present invention to provide a basic understanding of certain aspects of the invention. It should be understood that the following summary is not an exhaustive overview of the invention. It is not intended to identify key or important aspects of the invention, nor is it intended to limit the scope of the invention. Its purpose is simply to present certain concepts in a simplified form as a prelude to the more detailed description discussed later.

[0005] In view of the shortcomings of the existing technology, the present invention provides a micro electro-hydraulic actuator, which solves the defects of the electric push rod device modification scheme such as high failure rate, low reliability and short life under harsh working conditions by improving the overall structure.

[0006] Specifically, the present invention provides a micro electro-hydraulic actuator, including a single electro-hydraulic actuator composed of one electro-hydraulic actuator unit or a multi-electro-hydraulic actuator composed of multiple electro-hydraulic actuator units; the electro-hydraulic actuator unit includes an electro-hydraulic actuator body, a proportional electromagnet arranged in the electro-hydraulic actuator body, a first proportional pressure reducing valve, a second proportional pressure reducing valve, a cylinder body, a piston mechanism and a rocker mechanism; the front end of the electro-hydraulic actuator body is provided with a front end cover, and the rear end of the electro-hydraulic actuator body is provided with a rear end cover, the front end cover and the cylinder body and the piston mechanism form a closed front cavity, and the rear end cover and the cylinder body and the piston mechanism form a closed rear cavity; the end of the piston mechanism is assembled and connected to the rocker mechanism, and the rocker mechanism A handle connected to a manual multi-way valve; the front cavity and the rear cavity are connected to the outlets of the first proportional pressure-reducing valve and the second proportional pressure-reducing valve respectively; the inlets of the first proportional pressure-reducing valve and the second proportional pressure-reducing valve are connected to the output port of the hydraulic oil, and the valve core control ends of the first proportional pressure-reducing valve and the second proportional pressure-reducing valve are connected to the proportional electromagnet; the proportional electromagnet generates corresponding thrust according to the magnitude of the input current, pushing the valve cores of the first proportional pressure-reducing valve and the second proportional pressure-reducing valve to move, and generates pressure that changes with the current at the outlets of the first proportional pressure-reducing valve and the second proportional pressure-reducing valve, which generates pressure in the front cavity and the rear cavity to push the piston mechanism to move, and then drives the rocker mechanism to move, thereby controlling the opening or reversing of the manual multi-way valve.

[0007] Through the above scheme, this device converts the current signal into a hydraulic oil pressure signal, and controls the hydraulic oil pressure by the size of the input current, thereby controlling the size of the piston output force, and further controlling the opening of the manual multi-way valve. It has good practicality, its principle is easy to implement, and its structure is simple, which greatly reduces the failure rate under harsh working conditions, thereby improving reliability and service life.

[0008] As a feasible solution, the piston mechanism includes a return spring seat, a return spring, and a piston located within the cylinder. The return spring seat is fixed within the cylinder. One end of the return spring is fixed to the return spring seat, and the other end is connected to the piston. The piston reciprocates within the cylinder under pressure. When the outlets of the first and second proportional pressure-reducing valves generate pressure that varies with current, the return spring deforms and stores elastic potential energy. When the pressure disappears, the return spring releases the stored elastic potential energy, driving the piston back to its initial or predetermined position.

[0009] As a feasible solution, the rocker mechanism includes a first connecting rod, a second connecting rod, a rocker shaft and a rocker rod connected in sequence, one end of the first connecting rod is connected to the piston mechanism, and the other end is rotatably connected to the first end of the second connecting rod through a pin shaft, and the second end of the second connecting rod is connected to the rocker rod through the rocker shaft.

[0010] As a further solution, the micro-electro-hydraulic actuator comprises a multi-unit electro-hydraulic actuator structure consisting of N electro-hydraulic actuator units, and a head piece for oil supply, oil return, and connection and fixation. N is a natural number from 2 to 12, and any number of electro-hydraulic actuator units within the 12-unit structure can be formed.

[0011] As a further solution, the micro electro-hydraulic actuator also includes a tail piece responsible for connection and fixation.

[0012] With this structure, hydraulic oil at a certain pressure (approximately 20 bar) enters the inlets of the first and second proportional pressure-reducing valves. The proportional solenoids generate thrust corresponding to the input current, pushing the valve cores of the first and second proportional pressure-reducing valves. This generates a current-dependent pressure at the outlets of the first and second proportional pressure-reducing valves. This pressure generates pressure in the front and rear chambers, pushing the pistons of the piston mechanism, which in turn drives the first and second connecting rods, the rocker shaft, and the rocker arm of the rocker mechanism. The rocker arm is connected to the handle of the manual multi-way valve via a connecting rod to switch the valve direction.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] This novel micro-electro-hydraulic actuator utilizes the aforementioned scheme to convert current signals into hydraulic oil pressure signals. The input current controls the hydraulic oil pressure, thereby controlling the piston output force and, consequently, the opening of the manual multi-way valve. This device allows for low-cost automation or remote control of engineering machinery and hydraulic equipment that utilize manual multi-way valves as main control valves. Furthermore, since all moving parts are fully immersed in hydraulic oil, providing excellent lubrication conditions, the device operates smoothly and reliably, with a long lifespan. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention can be better understood by referring to the following description in conjunction with the accompanying drawings, wherein the same or similar reference numerals are used throughout the drawings to represent the same or similar components. The accompanying drawings, together with the following detailed description, are incorporated into and form a part of this specification and are used to further illustrate the preferred embodiments of the present invention and to explain the principles and advantages of the present invention. In the drawings:

[0016] Figure 1 This is a cross-sectional view of the electro-hydraulic actuator unit according to an embodiment of the present invention. Figure 1 ;

[0017] Figure 2 This is a cross-sectional view of the electro-hydraulic actuator unit according to an embodiment of the present invention. Figure 2 ;

[0018] Figure 3 Schematic diagram of the appearance of a 4-unit micro electro-hydraulic actuator in an embodiment of the present utility model. DETAILED DESCRIPTION

[0019] The following describes embodiments of the present invention with reference to the accompanying drawings. Elements and features described in one drawing or one embodiment of the present invention may be combined with elements and features shown in one or more other drawings or embodiments. It should be noted that for the sake of clarity, the drawings and descriptions omit the representation and description of components and processes that are not relevant to the present invention and are known to those of ordinary skill in the art.

[0020] In the description of this utility model, it should be understood that the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be interpreted broadly. For example, they can refer to fixed connections, removable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal connections between two components. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0021] The purpose of this utility model is to address the drawbacks of electric push rod device modification solutions, such as high failure rates, low reliability, and short lifespans under harsh operating conditions, by improving the overall electro-hydraulic actuator structure. The micro electro-hydraulic actuator of this utility model can be a single-unit electro-hydraulic actuator consisting of a single electro-hydraulic actuator unit, or a multi-unit electro-hydraulic actuator consisting of multiple electro-hydraulic actuator units.

[0022] As a specific embodiment, the structure of a single-link micro electro-hydraulic actuator is as follows: Figure 1 and Figure 2 As shown, it includes an electro-hydraulic actuator unit, which mainly consists of a proportional solenoid 1, a first proportional pressure reducing valve 21, a second proportional pressure reducing valve 22, a rear end cover 3, a return spring seat 4, a return spring 5, a cylinder 6, a piston 7, a first connecting rod 8, a second connecting rod 9, a rocker shaft 10, a front end cover 11, and a rocker 12.

[0023] Hydraulic oil with a certain pressure (about 20 bar) enters the inlet of the first proportional pressure-reducing valve 21 and the second proportional pressure-reducing valve 22. The proportional solenoid 1 generates a variable thrust according to the magnitude of the input current, pushing the valve core of the proportional pressure-reducing valve to move, and generating a pressure at the outlet of the proportional pressure-reducing valve that varies with the current.

[0024] The front end cover 11, cylinder 6, and piston 7 form a closed front cavity, while the rear end cover 3, cylinder 6, and piston 7 form a closed rear cavity. The front cavity and rear cavity are respectively connected to the outlets of two proportional pressure-reducing valves (first proportional pressure-reducing valve 21 and second proportional pressure-reducing valve 22).

[0025] The cylinder 6 provides an enclosed space within which the piston reciprocates. The return spring seat 4, used to secure and support the return spring 5, is installed in a suitable position within the cylinder to ensure its proper function. The return spring 5 is a mechanical spring that stores elastic potential energy and generates a restoring force upon the removal of an external force, returning the piston or other moving component to its initial or predetermined position. The piston is connected to the first connecting rod 8.

[0026] After pressure is generated in the front cavity and the rear cavity, the piston 7 is pushed to move, which in turn drives the first connecting rod 8, the second connecting rod 9, the rocker shaft 10 and the rocker 12 to move.

[0027] The rocker arm 12 is connected to the handle of the manual multi-way valve through a connecting rod to switch the valve.

[0028] When the proportional solenoid 1 is powered off, the outlet of the proportional pressure reducing valve 2 is connected to the main oil return port, the pressure is 0, and the piston 7 returns to the middle position under the action of the return spring 5.

[0029] The output force of the rocker 12 is proportional to the input current of the electromagnet 1 .

[0030] This device can be used to perform low-cost automation or remote control transformation on engineering machinery and hydraulic equipment that use manual multi-way valves as main control valves. Moreover, since all moving parts in this device are completely immersed in hydraulic oil and have good lubrication conditions, it operates smoothly and reliably, and has a long service life.

[0031] Through the above scheme, this device converts the current signal into a hydraulic oil pressure signal, and controls the hydraulic oil pressure by the input current, thereby controlling the piston output force and further controlling the opening of the manual multi-way valve.

[0032] As another specific embodiment, the micro electro-hydraulic actuator of the present invention is a multi-electro-hydraulic actuator composed of multiple electro-hydraulic actuator units, such as Figure 3 As shown, a 4-unit micro electro-hydraulic actuator consists of four electro-hydraulic actuator units 100 (also known as a single-unit micro electro-hydraulic actuator), a head piece 101, and a tail piece 102. The head piece 101 is responsible for oil supply, oil return, and connection and fixation, while the tail piece 102 is responsible for connection and fixation. Similarly, any number of units from 1 to 12 can be configured.

[0033] It should be emphasized that the term "include / comprises" when used herein refers to the existence of features, elements, steps or components, but does not exclude the existence or addition of one or more other features, elements, steps or components.

[0034] Although the present invention has been disclosed above through the description of specific embodiments of the present invention, it should be understood that all the above embodiments and examples are illustrative rather than restrictive. Those skilled in the art may design various modifications, improvements, or equivalents of the present invention within the spirit and scope of the appended claims. Such modifications, improvements, or equivalents should also be considered to be included within the scope of protection of the present invention.

Claims

1. A micro electro-hydraulic actuator, characterized in that: Including a single electro-hydraulic actuator consisting of one electro-hydraulic actuator unit or a multi-electro-hydraulic actuator consisting of multiple electro-hydraulic actuator units; The electro-hydraulic actuator unit includes an electro-hydraulic actuator body, a proportional electromagnet arranged in the electro-hydraulic actuator body, a first proportional pressure reducing valve, a second proportional pressure reducing valve, a cylinder body, a piston mechanism and a rocker mechanism; The front end of the electro-hydraulic actuator body is provided with a front cover, and the rear end of the electro-hydraulic actuator body is provided with a rear cover. The front end cover, the cylinder body, and the piston mechanism form a closed front cavity, and the rear end cover, the cylinder body, and the piston mechanism form a closed rear cavity. The end of the piston mechanism is assembled and connected to the rocker mechanism, and the rocker mechanism is connected to the handle of the manual multi-way valve; The front cavity and the rear cavity are respectively connected to the outlets of the first proportional pressure-reducing valve and the second proportional pressure-reducing valve; the inlets of the first proportional pressure-reducing valve and the second proportional pressure-reducing valve are connected to the output port of the hydraulic oil, and the valve core control ends of the first proportional pressure-reducing valve and the second proportional pressure-reducing valve are connected to the proportional solenoid; The proportional solenoid generates a corresponding thrust according to the magnitude of the input current, pushing the valve cores of the first proportional pressure-reducing valve and the second proportional pressure-reducing valve to move, and generates a pressure at the outlets of the first proportional pressure-reducing valve and the second proportional pressure-reducing valve that varies with the current. This pressure generates pressure in the front cavity and the rear cavity to push the piston mechanism to move, and then drives the rocker mechanism to move, thereby controlling the opening or reversing of the manual multi-way valve.

2. The micro electro-hydraulic actuator according to claim 1, characterized in that: The piston mechanism includes a return spring seat, a return spring and a piston arranged inside the cylinder body. The return spring seat is fixed in the cylinder body. One end of the return spring is fixed on the return spring seat and the other end is connected to the piston. The piston reciprocates in the cylinder body under pressure.

3. The micro electro-hydraulic actuator according to claim 1 or 2, characterized in that: The rocker mechanism includes a first connecting rod, a second connecting rod, a rocker shaft and a rocker rod connected in sequence. One end of the first connecting rod is connected to the piston mechanism, and the other end is rotatably connected to the first end of the second connecting rod through a pin shaft. The second end of the second connecting rod is connected to the rocker rod through the rocker shaft.

4. The micro electro-hydraulic actuator according to claim 1, characterized in that: The micro electro-hydraulic actuator includes a multi-unit electro-hydraulic actuator composed of N electro-hydraulic actuator units, and a head piece used for oil inlet, oil return and connection and fixation.

5. The micro electro-hydraulic actuator according to claim 4, characterized in that: The micro electro-hydraulic actuator also includes a tail piece responsible for connection and fixation.

6. The micro electro-hydraulic actuator according to claim 4, characterized in that: N is a natural number from 2 to 12.

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