Flat plate sliding knife type hydraulic slide valve structure and electro-hydraulic servo valve using same

Abstract

The application belongs to the technical field of electro-hydraulic servo valves, and particularly discloses a flat plate sliding knife type hydraulic slide valve structure and an electro-hydraulic servo valve using the same, which comprises a first limiting block, a valve core plug, a flat plate sliding knife, a valve core and a second limiting block, wherein the first limiting block and the second limiting block respectively abut against two end faces of the valve core from two sides, the flat plate sliding knife is inserted above the valve core, the valve core plug is installed in a threaded hole of the end face of the valve core, the flat plate sliding knife slides on the valve core, and the control of the output flow of the slide valve is realized by changing the flow area of the oil inlet hole on the valve core. The servo valve adopts the flat plate sliding knife type structure to replace the traditional valve core valve sleeve structure, can effectively solve the problems of high cooperation size requirement and difficult machining of the slide valve, reduces the machining cost of the slide valve, and has the advantages of small driving force, high dynamic performance and strong anti-pollution ability.

Description

Technical Field

[0001] This invention relates to an electro-hydraulic servo valve, and more particularly to an electro-hydraulic servo valve with a flat slide valve structure and its application. Background Technology

[0002] Cylindrical spool valves are a common type of spool valve used in electro-hydraulic servo valves. They consist of a valve sleeve and a valve core. The valve sleeve has a recessed groove, and the gap between the edge of the valve sleeve and the shoulder edge of the valve core forms a variable throttling orifice. The movement of the valve core changes the flow area of ​​the throttling orifice, thereby controlling the fluid flow rate. Cylindrical spool valves have a large moment of inertia and require a large driving force. They are generally used as the power stage of two-stage electro-hydraulic servo valves and are difficult to apply to single-stage servo valves with compact structures and lower driving forces. Furthermore, cylindrical spool valves have strict axial and radial dimensional requirements, complex structures and processes, high manufacturing and assembly difficulties, and high processing costs. At the same time, the accumulation of contaminants in the tiny gaps can easily cause the spool valve to jam, affecting the working performance of the electro-hydraulic servo valve and reducing its service life. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a flat sliding blade type hydraulic spool valve structure. By replacing the traditional valve core and valve sleeve structure with a flat sliding blade type structure, the problem of high requirements for spool valve mating dimensions and difficult processing can be effectively solved, the driving force required for spool valve movement can be reduced, and the spool valve's anti-pollution ability can be improved.

[0004] To achieve the above objectives, the present invention provides a flat sliding blade type hydraulic spool valve structure using the following technical solution:

[0005] A flat slide valve structure is disclosed, comprising: a first limiting block, a valve core plug, a flat slide, a valve core, and a second limiting block, wherein the first limiting block and the second limiting block respectively abut against the two end faces of the valve core from both sides; the flat slide is inserted above the valve core; and the valve core plug is inserted into the threaded hole on the end face of the valve core.

[0006] The valve core includes a first valve core shaft end, a third valve core shaft end, and a second valve core shaft end located between the first valve core shaft end and the third valve core shaft end. The first valve core shaft end is provided with a first oil inlet hole and a second oil inlet hole spaced apart. The second valve core shaft end is provided with a return oil hole. The side of the first valve core shaft end is provided with a first oil passage hole and a second oil passage hole spaced apart. The first oil passage hole and the second oil passage hole respectively connect the first oil inlet hole and the second oil inlet hole to the return oil hole. A first control cavity is formed between the first oil inlet hole, the first oil passage hole, and the return oil hole. A second control cavity is formed between the second oil inlet hole, the second oil passage hole, and the return oil hole.

[0007] Furthermore, the flat slide cutter includes a mounting hole, a slide cutter groove, and a retraction groove; the mounting hole is connected to an external transmission component to realize motion control of the flat slide cutter; the slide cutter groove is used for the flat slide cutter to be inserted into the valve core, and the retraction groove serves as a machining groove for the slide cutter groove.

[0008] Furthermore, the flat slide cutter slides left and right on the first valve core shaft end. When the flat slide cutter slides to the right, the flow window area formed by it and the first oil inlet hole and the second oil inlet hole on the first valve core shaft end gradually increases, and the oil flow rate entering the first control cavity and the second control cavity increases. When the flat slide cutter slides to the left, the flow window area formed by it and the first oil inlet hole and the second oil inlet hole gradually decreases, and the oil flow rate entering the first control cavity and the second control cavity decreases.

[0009] Furthermore, the sliding groove is designed as a parallel flat plate structure, which reduces the difficulty of processing and assembly.

[0010] Furthermore, the width of the flat slide blade is such that, when in the middle position, it can reliably cover the first and second oil inlet holes on the valve core, thereby reducing the leakage at the middle position.

[0011] Furthermore, the four edges of the flat slide cutter are chamfered to reduce workpiece weight, decrease moment of inertia, and improve dynamic performance.

[0012] Furthermore, the sliding groove is machined to fit the end of the first valve core shaft with a clearance of 10-15μm to ensure reliable sliding of the flat sliding blade and reduce sliding friction.

[0013] Furthermore, the first and second oil inlets on the valve core are independent of each other, and a certain angle is formed between the two oil inlets; this is used to realize dual-redundancy control of the two flow windows and improve the reliability of the hydraulic spool valve.

[0014] Furthermore, the end faces of the first and second limiting blocks are provided with slots to facilitate installation and disassembly.

[0015] This invention also proposes an electro-hydraulic servo valve, which includes a torque motor, an armature-rocker assembly, a hydraulic spool valve, and a valve body assembly. The torque motor adopts a permanent magnet structure, including a lower magnetic conductor, an upper magnetic conductor, a coil assembly, and a magnet. The armature-rocker assembly includes an armature, an armature screw, a rocker arm, and a Bourdon tube. The Bourdon tube supports the armature-rocker assembly and partially isolates the torque motor from the hydraulic spool valve. The hydraulic spool valve adopts the flat slide-blade type hydraulic spool valve structure described above.

[0016] The beneficial effects of this invention are as follows:

[0017] 1. This invention differs from the traditional cylindrical slide valve structure. This new slide valve structure adopts a flat slide blade structure, which reduces the axial and radial dimension requirements, simplifies the process, and reduces manufacturing costs.

[0018] 2. This invention differs from the traditional valve core and valve sleeve structure. The flat sliding blade structure avoids the problem of contaminant jamming caused by tiny gaps in the valve core and valve sleeve, thus improving the anti-contamination capability and reliability of the electro-hydraulic servo valve.

[0019] 3. This invention differs from the existing method of controlling the opening of the oil inlet window by the movement of the valve core. This new structure controls the opening of the oil inlet window by the movement of the sliding blade, reducing the inertia of the moving parts, reducing the driving force required for the movement of the slide valve, and improving the dynamic performance of the slide valve. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an electro-hydraulic servo valve;

[0021] Figure 2 This is a schematic diagram of a flat slide valve type hydraulic spool valve.

[0022] Figure 3 This is a schematic diagram of the structure of a flat slide cutter;

[0023] Figure 4 This is a schematic diagram of the valve core structure;

[0024] Wherein, 1—first end cap, 2—first limiting block, 3—shell, 4—lower magnetic conductor, 5—armature, 6—upper magnetic conductor, 7—coil assembly, 8—armature screw, 9—magnet, 10—swing rod, 11—spring tube, 12—flat slide bar, 13—valve core, 14—second limiting block, 15—second end cap, 16—valve core plug, 17—first control cavity, 18—second control cavity;

[0025] 12.1—Mounting hole, 12.2—Slide groove, 12.3—Unsinking groove;

[0026] 13.1—First valve spindle end, 13.2—Second valve spindle end, 13.3—Third valve spindle end, 13.4—First oil passage hole, 13.5—Second oil passage hole, 13.6—First oil inlet hole, 13.7—Second oil inlet hole, 13.8—Oil return hole. Detailed Implementation

[0027] To more intuitively and clearly illustrate the structural principles in the embodiments of the present invention, the following description will be based on the accompanying drawings. The drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0028] like Figure 1 As shown, an embodiment of the present invention provides an electro-hydraulic servo valve, including a torque motor, an armature-rocker assembly, a hydraulic spool valve, and a valve body assembly. The torque motor adopts a permanent magnet structure, including a lower magnetic conductor 4, an upper magnetic conductor 6, a coil assembly 7, and a magnet 9. The armature-rocker assembly includes an armature 5, an armature screw 8, a rocker arm 10, and a spring tube 11. The spring tube 11 supports the armature-rocker assembly and partially isolates the torque motor from the hydraulic spool valve. The hydraulic spool valve includes a first limiting block 2, a flat slide bar 12, a valve core 13, and a second limiting block 14, etc. The flat slide bar 12 is connected to the rocker arm 10. The valve body assembly includes a housing 3, a first end cap 1, and a second end cap 15.

[0029] like Figure 2 As shown, an embodiment of the present invention also provides a flat slide valve structure including: a first limiting block 2, a valve core plug 16, a flat slide 12, a valve core 13, and a second limiting block 14, wherein the first limiting block 2 and the second limiting block 14 respectively abut against the two end faces of the valve core from both sides; the flat slide 12 is inserted above the valve core 13; and the valve core plug 16 is installed in the threaded hole on the end face of the valve core.

[0030] In the hydraulic spool valve structure designed above, the valve core 13 includes a first valve core shaft end 13.1, a third valve core shaft end 13.3, and a second valve core shaft end 13.2 located between the first valve core shaft end 13.1 and the third valve core shaft end 13.3. The first valve core shaft end 13.1 is provided with a first oil inlet hole 13.6 and a second oil inlet hole 13.7 spaced apart. The second valve core shaft end 13.2 is provided with a return oil hole 13.8. The first valve core shaft end 13.1 has a side spaced apart... A first oil passage 13.4 and a second oil passage 13.5 are provided. The first oil passage 13.4 and the second oil passage 13.5 connect the first oil inlet 13.6 and the second oil inlet 13.7 to the oil return hole 13.8, respectively. A first control cavity 17 is formed between the first oil inlet 13.6, the first oil passage 13.4 and the oil return hole 13.8. A second control cavity 18 is formed between the second oil inlet 13.7, the second oil passage 13.5 and the oil return hole 13.8.

[0031] In the hydraulic slide valve structure specifically designed above, the flat slide knife 12 includes a mounting hole 12.1, a slide knife groove 12.2, and a knife retraction groove 12.3.

[0032] In the hydraulic spool valve structure designed above, the flat slide 12 slides left and right on the first valve core shaft end 13.1. When the flat slide 12 slides to the right, the flow window area formed by it and the first oil inlet hole 13.6 and the second oil inlet hole 13.7 on the first valve core shaft end 13.1 gradually increases, and the oil flow rate entering the first control cavity 17 and the second control cavity 18 increases. When the flat slide 12 slides to the left, the flow window area formed by it and the first oil inlet hole 13.6 and the second oil inlet hole 13.7 gradually decreases, and the oil flow rate entering the first control cavity 17 and the second control cavity 18 decreases.

[0033] The following is another embodiment of the present invention.

[0034] The embodiments of the present invention provide an electro-hydraulic servo valve structure with a flat slide valve structure, which consists of a torque motor, an armature-rocker assembly, a hydraulic slide valve and a valve body assembly. The movement of the flat slide valve controls the opening of the oil inlet window of the slide valve to control the output flow of the electro-hydraulic servo valve. The flat slide valve has low dimensional requirements, which reduces the processing difficulty, lowers the manufacturing cost and improves the anti-pollution ability.

[0035] When there is no control signal, the armature 5 of the torque motor is in the equilibrium position, the rocker arm 10 is in the center axis position of the inner hole of the spring tube 11, and the flat slide knife 12 is in the middle position with the rocker arm 10. At this time, the flat slide knife 12 completely covers the first oil inlet hole 13.6 and the second oil inlet hole 13.7 on the valve core 13. High pressure oil flows in from the oil supply port P, but cannot flow into the first control cavity 17 and the second control cavity 18. No oil flows out of the valve core return hole 13.8, and the electro-hydraulic servo valve does not output flow.

[0036] When a control signal is received, the armature 5 drives the rocker arm 10 to deflect to the right by a certain angle, causing the flat slide knife 12 to deviate from the middle position to the right. The first oil inlet hole 13.6 and the second oil inlet hole 13.7 on the valve core 13 form a certain opening with the flat slide knife 12, allowing high-pressure oil to flow into the first control cavity 17 and the second control cavity 18 through the first oil inlet hole 13.6 and the second oil inlet hole 13.7 respectively. There is oil output from the valve core return oil hole 13.8, and the electro-hydraulic servo valve outputs control flow.

[0037] In the above implementation example, the sliding groove 12.2 is designed as a parallel flat plate structure, reducing the difficulty of machining and assembly. The width of the relief groove 12.2 is 8mm, ensuring that when the flat sliding blade is in the middle position, it can reliably cover the first oil inlet hole 13.6 and the second oil inlet hole 13.7 on the valve core 13, reducing the mid-position leakage. The width of the relief groove 12.2 has no strict tolerance requirements, reducing the difficulty of radial dimension matching and simplifying the process.

[0038] The four edges of the flat slide cutter 12 are chamfered at 45° to reduce the weight of the workpiece, reduce the moment of inertia, and improve dynamic performance.

[0039] The flat slide cutter 12 and the rocker arm 10 are connected by a threaded connection through the mounting hole 12.1. The thread is designed as a fine thread to enhance the thread fastening, improve the anti-loosening ability, and ensure the precise motion control of the flat slide cutter.

[0040] The sliding groove 12.2 is machined to fit the first valve core shaft end 13.1 with a fit clearance of 10-15μm to ensure reliable sliding of the flat sliding blade and reduce sliding friction.

[0041] The first oil inlet hole 13.6 and the second oil inlet hole 13.7 on the valve core are independent of each other and are used to realize dual-redundancy control of the two flow windows, thereby improving the reliability of the hydraulic slide valve.

[0042] The end faces of the first limiting block 2 and the second limiting block 14 have slots for easy installation and disassembly.

[0043] This invention discloses a novel flat-plate sliding-blade type hydraulic spool valve structure and its application in an electro-hydraulic servo valve, and provides a zero-position adjustment method for the flat-plate sliding-blade type hydraulic spool valve structure, as detailed below:

[0044] Zero-position adjustment method: After the flat slide blade structure is installed as described above, the oil return hole 13.8 on the valve core 13 is connected to the flow sensor through the oil inlet on the housing. Read the reading of the flow sensor at this time. When the flow sensor has no reading, gently tap the spring tube 11 to the right. The torque generated by the tap is transmitted to the swing arm 10 through the armature-swing arm assembly, thereby controlling the movement of the flat slide blade 12. When the reading of the flow sensor is greater than 1L / min, gently tap the spring tube 11 to the left. After several repeated taps to the left and right, the final reading of the flow sensor is exactly zero, completing the zero-position adjustment of the present invention, that is, the flat slide blade is at zero position and the servo valve does not output flow.

[0045] This invention provides a flat slide valve structure. Compared with the traditional cylindrical slide valve structure, the flat slide valve structure replaces the original valve core and valve sleeve structure, avoiding the manufacturing difficulties caused by strict axial and radial dimensional requirements. It simplifies the process, reduces processing costs, and effectively solves the problem of contaminant jamming in the tiny gaps inside the valve core and valve sleeve, thus improving the anti-contamination capability of the electro-hydraulic servo valve.

[0046] The present invention also provides an electro-hydraulic servo valve using a flat slide valve structure. Unlike existing electro-hydraulic servo valves that control the opening of the oil inlet window through the movement of the valve core, this new structure controls the opening of the oil inlet window through the movement of the slide valve, reducing the inertia of the moving parts and the driving force required for the movement of the slide valve. It is suitable as the power stage of a single-stage servo valve and greatly improves the dynamic performance of the electro-hydraulic servo valve.

[0047] Finally, it should be noted that the above embodiments or examples are only used to illustrate the technical solutions of the present invention. Any omissions are considered as conventional technical means or common knowledge in the field. It should be understood that the protection scope of the present invention is not limited to the specific embodiments described above. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions should be included within the protection scope of the present invention.

Claims

1. A flat sliding blade type hydraulic spool valve structure, characterized in that, The spool valve structure includes: a first limiting block, a valve core plug, a flat sliding blade, a valve core, and a second limiting block. The first and second limiting blocks respectively abut against the two end faces of the valve core from both sides. The flat sliding blade is inserted above the valve core. The valve core plug is inserted into a threaded hole on the end face of the valve core. The valve core includes a first valve core shaft end, a third valve core shaft end, and a second valve core shaft end located between the first and third valve core shaft ends. The first valve core shaft end has a first oil inlet hole and a second oil inlet hole spaced apart, and the second valve core shaft end has... The first valve core shaft end has a return oil hole, and a first oil passage hole and a second oil passage hole are spaced apart on the side. The first oil passage hole and the second oil passage hole respectively connect the first oil inlet hole and the second oil inlet hole to the return oil hole. A first control cavity is formed between the first oil inlet hole, the first oil passage hole and the return oil hole. A second control cavity is formed between the second oil inlet hole, the second oil passage hole and the return oil hole. The flat slide knife can slide left and right on the first valve core shaft end to adjust the flow window area formed by it and the first oil inlet hole and the second oil inlet hole on the first valve core shaft end.

2. The flat sliding blade type hydraulic spool valve structure as described in claim 1, characterized in that, When the flat slide cutter slides to the right, the flow window area formed by it and the first oil inlet and the second oil inlet on the first valve core shaft gradually increases, and the oil flow rate entering the first control cavity and the second control cavity increases; when the flat slide cutter slides to the left, the flow window area formed by it and the first oil inlet and the second oil inlet gradually decreases, and the oil flow rate entering the first control cavity and the second control cavity decreases.

3. The flat sliding blade type hydraulic spool valve structure as described in claim 2, characterized in that, The flat slide cutter includes a mounting hole, a slide cutter groove, and a retraction groove; the mounting hole is connected to an external transmission component to realize the motion control of the flat slide cutter; the slide cutter groove is used for the flat slide cutter to be inserted into the valve core, and the retraction groove serves as a machining groove for the slide cutter groove.

4. The flat sliding blade type hydraulic spool valve structure as described in claim 3, characterized in that, The sliding groove is designed as a parallel flat plate structure.

5. The flat sliding blade type hydraulic spool valve structure as described in claim 3, characterized in that, The width of the flat slide blade is such that, when it is in the middle position, it can reliably cover the first and second oil inlet holes on the valve core.

6. The flat sliding blade type hydraulic spool valve structure as described in claim 3, characterized in that, The four edges of the flat slide cutter are beveled.

7. The flat sliding blade type hydraulic spool valve structure as described in claim 3, characterized in that, The sliding groove is machined to fit the end of the first valve core shaft, with a fit clearance of 10-15μm.

8. The flat sliding blade type hydraulic spool valve structure as described in claim 1, characterized in that, The first and second oil inlets on the valve core are independent of each other, and a certain angle is formed between the two oil inlets; this is used to achieve dual-redundancy control of the two flow windows.

9. The flat sliding blade type hydraulic spool valve structure as described in claim 1, characterized in that, The end faces of the first and second limiting blocks have slots.

10. An electro-hydraulic servo valve, the servo valve comprising a torque motor, an armature-rocker assembly, a hydraulic spool valve, and a valve body assembly, wherein the torque motor employs a permanent magnet structure, comprising a lower magnetic conductor, an upper magnetic conductor, a coil assembly, and a magnet; the armature-rocker assembly comprises an armature, an armature screw, a rocker arm, and a Bourdon tube, the Bourdon tube supporting the armature-rocker assembly and partially isolating the torque motor from the hydraulic spool valve; characterized in that… The hydraulic slide valve adopts the flat slide type hydraulic slide valve structure as described in any one of claims 1 to 9.

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