A coaxiality calibration tool for a direct-drive servo valve connecting rod and a servo valve spool

Abstract

The application relates to a coaxiality calibration tool for a direct-drive servo valve connecting rod and a servo valve spool, which comprises a main frame, sliding guide rails arranged on the main frame, a V-shaped groove arranged on the main frame and two sliders which can slide along the sliding guide rails, the main frame is sleeved on the sliding guide rails, the main frame is provided with a servo valve spool assembly for calibration and a pressing assembly for pressing the servo valve spool assembly, the servo valve spool assembly is arranged on the V-shaped groove, the two sliders are divided into upper and lower parts, semicircular grooves are arranged on the upper and lower parts of the sliders, and the semicircular grooves can clamp the servo valve spool assembly. The servo valve spool axis positioned by the V-shaped groove is taken as a core reference of the whole tool, cumulative errors caused by multiple references are avoided, the reliability of the calibration result is improved, the tool is designed through a precise positioning structure, convenient operation and a universal adjustment function, and the coaxiality calibration precision of the servo valve spool assembly can be efficiently ensured.

Description

Technical Field

[0001] This application relates to the field of precision mechanical calibration technology, and in particular to a tooling for calibrating the coaxiality of a direct-drive servo valve connecting rod and a servo valve core. Background Technology

[0002] In the field of servo valve manufacturing, the coaxiality calibration of the connecting rod and the servo valve spool is a crucial step in ensuring the dynamic response accuracy of the valve body. Currently, high-precision servo valves generally adopt a direct-drive structure. The coaxiality deviation between the motor connecting rod and the servo valve spool directly affects the linear transmission of the control signal. As hydraulic systems develop towards high pressure and high frequency, the repeatability requirements for servo valves have increased to the micrometer level, and traditional calibration methods are difficult to meet the needs of modern industry.

[0003] In existing technologies, the main methods involve segmented inspection using a coordinate measuring machine followed by manual adjustment (time-consuming and dependent on operator experience), or the use of multi-reference positioning fixtures (such as split-type fixtures with dial indicators for calibration). The former is inefficient and inconsistent, while the latter is prone to cumulative errors due to reference conversion. While laser alignment offers higher accuracy, the equipment is expensive and sensitive to environmental vibrations.

[0004] The aforementioned technologies suffer from several drawbacks: the accumulation of errors due to the superposition of multiple references, low efficiency of manual operation, poor adaptability of high-end testing equipment, and high maintenance costs, making it impossible to simultaneously meet the accuracy and efficiency requirements of mass production. Summary of the Invention

[0005] To address the issues of error accumulation due to multiple reference superposition, low efficiency of manual operation, poor adaptability and high maintenance costs of high-end testing equipment, and the inability to meet the accuracy and efficiency requirements of mass production, this application provides a direct-drive servo valve connecting rod and servo valve core coaxiality calibration fixture.

[0006] This application provides a tooling for calibrating the coaxiality of a direct-drive servo valve connecting rod and servo valve core, employing the following technical solution: A direct-drive servo valve connecting rod and servo valve core coaxiality calibration fixture includes a main frame, a sliding guide rail mounted on the main frame, a V-groove mounted on the main frame, and two sliders that can slide along the sliding guide rail. The main frame is sleeved on the sliding guide rail. The main frame is equipped with a servo valve core assembly for calibration and a clamping assembly for clamping the servo valve core assembly. The servo valve core assembly is mounted on the V-groove. The sliders are divided into upper and lower parts, and each of the upper and lower parts of the slider has a semi-circular groove that can clamp the servo valve core assembly.

[0007] By adopting the above technical solution, the entire fixture uses the servo valve core axis positioned by the V-groove as the core reference. The servo valve core assembly is aligned with this reference through a slider, forming a calibration logic of "single reference - multiple workpiece alignment". This avoids the cumulative error caused by the superposition of multiple references, improves the reliability of the calibration results, and enables the fixture to not only efficiently ensure the coaxiality calibration accuracy of the servo valve core assembly through its precise positioning structure, convenient operation design and universal adjustment function, but also adapt to diverse workpiece specifications.

[0008] Preferably, the servo valve core assembly includes a servo valve core, a force motor connecting rod, and a displacement sensor extension rod; one end of the force motor connecting rod is connected to a force motor, and the other end of the force motor connecting rod is connected to the servo valve core; one end of the displacement sensor extension rod is connected to a displacement sensor, and the other end of the displacement sensor extension rod is connected to the servo valve core.

[0009] By adopting the above technical solution, the servo valve core assembly is the core moving part: its displacement directly determines the output signal of the sensor, while the driving force of the servo valve motor is transmitted to the servo valve core through the motor linkage. The displacement sensor extension rod may be used for extended detection of the servo valve core displacement or auxiliary positioning. The coaxiality of the servo valve core, motor linkage and displacement sensor extension rod directly affects the closed-loop accuracy of "driving force transmission → valve core movement → displacement detection".

[0010] Preferably, the clamping assembly includes a pressure plate for clamping the servo valve core assembly, a screw, and a nut block for clamping the pressure plate. The end of the pressure plate away from the servo valve core assembly is rotatably connected to the main frame, and the top end of the screw passes through the bottom end of the main frame and is threadedly connected to the nut.

[0011] By adopting the above technical solution, the end of the pressure plate away from the servo valve core is rotatably connected to the main frame, forming a structure similar to a "flip cover". When loading and unloading the servo valve core, simply loosen the nut pressure block and lift the pressure plate to quickly pick up and put down the parts without completely disassembling the clamping assembly, which greatly improves the efficiency of calibration operation. If it is necessary to fine-tune the sensor position during calibration, the sensor can also be gently rotated or moved after loosening the nut pressure block, making the operation flexible.

[0012] Preferably, the surface of the nut block is provided with a handle for assisting the rotation of the nut block, and the handle is fixedly connected to the nut block by bolts.

[0013] By adopting the above technical solution, the handle provides a convenient force application point for rotating the nut pressure block. Compared with directly turning the nut pressure block by hand, it is easier to achieve the action of tightening or loosening. Especially when it is necessary to repeatedly adjust the tightening force, it can significantly reduce the operation time and manpower consumption and improve the calibration efficiency.

[0014] Preferably, the upper and lower parts of the slider are detachably connected, and the upper and lower parts of the slider are connected and fixed by bolts.

[0015] By adopting the above technical solution, the upper and lower parts are detachably connected by bolts. Loosening the bolts can separate the slider, and the force motor connecting rod or displacement sensor extension rod can be directly placed into the semi-circular groove. Then, tightening the bolts completes the clamping. By adjusting the tightening torque of the bolts, the clamping force of the upper and lower semi-circular grooves on the workpiece can be flexibly controlled, which ensures that the workpiece is stably fixed (avoiding displacement during calibration) and prevents workpiece deformation caused by excessive tightness (especially for precision connecting rods or slender extension rods), thus taking into account both clamping stability and workpiece protection.

[0016] Preferably, the servo valve core of the servo valve core assembly is on the same straight line as the center line of the force motor connecting rod and the displacement sensor extension rod.

[0017] By adopting the above technical solution, the center lines of the servo valve core assembly, the force motor connecting rod, and the displacement sensor extension rod are aligned on the same straight line. This collinear design allows the servo valve core to move synchronously with the force motor connecting rod and the displacement sensor extension rod, making its calibration more accurate and significantly extending its service life.

[0018] Preferably, the sliding guide rail is convex in shape, and the sliding guide rail is slidably connected to the slider and the main frame.

[0019] By adopting the above technical solution, compared with ordinary flat guide rails or V-shaped guide rails, the convex structure has a surface contact rather than a line contact between the convex part and the mating part. This can disperse the pressure during the movement of the slider, reduce local wear, and at the same time reduce the risk of "jamming" caused by uneven force, thus ensuring the smoothness of the sliding process.

[0020] Preferably, the V-groove on the main frame and the semi-circular groove of the lower part of the slider are on the same straight line.

[0021] By adopting the above technical solution, the "automatic centering" characteristic of the V-groove and the "enclosing and limiting" characteristic of the semi-circular groove are combined to form a bidirectional constraint on the passing parts, ensuring that their axis is completely consistent with the preset trajectory, avoiding the skewing of the parts caused by the misalignment of the two grooves, and significantly improving the positioning accuracy.

[0022] In summary, this application includes at least one of the following beneficial technical effects: 1. The entire fixture uses the servo valve core axis positioned by the V-groove as the core reference. The connecting rod and extension rod are aligned with this reference through the slider, forming a calibration logic of "single reference - multiple workpiece alignment". This avoids the cumulative error caused by the superposition of multiple references, improves the reliability of the calibration results, and enables the fixture to efficiently ensure the coaxiality calibration accuracy of the force motor connecting rod and the servo valve core through precise positioning structure, convenient operation design and universal adjustment function, while also adapting to diverse workpiece specifications. 2. The end of the pressure plate furthest from the servo valve core is rotatably connected to the main frame, forming a "flip-top" structure. When loading or unloading the servo valve core assembly, simply loosen the nut pressure block and lift the pressure plate to quickly pick up or put down the component without completely disassembling the clamping assembly, greatly improving the efficiency of calibration operations. If the sensor position needs to be finely adjusted during calibration, the sensor can also be gently rotated or moved by loosening the nut pressure block, making the operation flexible. 3. Compared with ordinary flat guide rails or V-shaped guide rails, the convex part of the convex structure has a surface contact with the mating part rather than a line contact. This can disperse the pressure during the movement of the slider, reduce local wear, and reduce the risk of "jamming" caused by uneven force, thus ensuring the smoothness of the sliding process. Attached Figure Description

[0023] Figure 1 This is a front-view perspective view of a fixture for calibrating the coaxiality of a direct-drive servo valve connecting rod and a servo valve core. Figure 2 This is a partial three-dimensional view of the fixture for calibrating the coaxiality of the connecting rod and the valve core of a direct-drive servo valve. Figure 3 This is a left-side sectional perspective view of the fixture for calibrating the coaxiality of the direct-drive servo valve connecting rod and the servo valve core. Figure 4 This is a top-view sectional perspective of the fixture for calibrating the coaxiality of the direct-drive servo valve connecting rod and the servo valve core. Figure 5 This is a rear view of the fixture for calibrating the coaxiality of the direct-drive servo valve connecting rod and the servo valve core.

[0024] Reference numerals: 100, main frame; 110, V-groove; 200, sliding guide rail; 300, slider; 310, semi-circular groove; 400, servo valve core; 410, servo valve core; 420, force motor connecting rod; 430, displacement sensor extension rod; 500, clamping assembly; 510, pressure plate; 520, screw; 530, nut pressure block; 540, handle. Detailed Implementation

[0025] The following is in conjunction with the appendix Figure 1 - Appendix Figure 5 This application will be described in further detail.

[0026] This application discloses a tooling for calibrating the coaxiality of a direct-drive servo valve connecting rod and a servo valve core.

[0027] Reference Figure 1 and Figure 2 A direct-drive servo valve connecting rod and servo valve core coaxiality calibration fixture includes a main frame 100, a sliding guide rail 200 mounted on the main frame 100, a V-groove 110 mounted on the main frame 100, a pressure plate 510 mounted on the main frame 100, and two sliders 300 that can slide along the sliding guide rail 200. The main frame 100 is sleeved on the sliding guide rail 200 and slidably connected to it. The V-groove 110 is located at the top of the main frame 100. The sliders 300 can be divided into upper and lower parts, each with a semi-circular groove 310. A servo valve core assembly 400 is disposed within the V-groove 110. A clamping assembly 500 for clamping the servo valve core assembly 400 is connected to the main frame 100. The connection between the clamping assembly 500 and the main frame 100 is adjustable. The entire fixture uses the axis of the servo valve core assembly 400, which is positioned by the V-groove 110, as the core reference. The servo valve core assembly 400 is aligned with this reference through the slider 300, forming a calibration logic of "single reference - multiple workpiece alignment". This avoids the cumulative error caused by the superposition of multiple references and improves the reliability of the calibration results. The fixture, through its precise positioning structure, convenient operation design and universal adjustment function, can not only efficiently ensure the coaxiality calibration accuracy of the servo valve core assembly 400, but also adapt to various workpiece specifications.

[0028] The servo valve core assembly 400 includes a servo valve core 410, a force motor connecting rod 420, and a displacement sensor extension rod 430. One end of the force motor connecting rod 420 is connected to a force motor, and the other end is connected to the servo valve core 410. One end of the displacement sensor extension rod 430 is connected to a displacement sensor, and the other end is connected to the servo valve core 410. The servo valve core assembly 400 is the core moving component: its displacement directly determines the output signal of the sensor. The driving force of the servo valve force motor is transmitted to the servo valve core 410 through the force motor connecting rod 420. The displacement sensor extension rod 430 may be used for extended detection or auxiliary positioning of the displacement of the servo valve core 410. The coaxiality of the servo valve core 410, the force motor connecting rod 420, and the displacement sensor extension rod 430 directly affects the closed-loop accuracy of "driving force transmission → valve core movement → displacement detection".

[0029] The center lines of the servo valve core 410 of the servo valve core assembly 400, the force motor connecting rod 420, and the displacement sensor extension rod 430 are on the same straight line. By aligning the center lines of the servo valve core 410, the force motor connecting rod 420, and the displacement sensor extension rod 430 with the center lines of the servo valve core assembly 400, the collinear design allows the servo valve core 410 to move synchronously with the force motor connecting rod 420 and the displacement sensor extension rod 430, making its calibration more accurate and significantly extending its service life.

[0030] The V-groove 110 on the main frame 100 and the semicircular groove 310 on the lower part of the slider 300 are on the same straight line. The combination of the "automatic centering" characteristic of the V-groove 110 and the "enclosing and limiting" characteristic of the semicircular groove 310 can form a bidirectional constraint on the passing parts, ensuring that their axis is completely consistent with the preset trajectory, avoiding the skew of the parts caused by the misalignment of the two grooves, and significantly improving the positioning accuracy.

[0031] refer to Figure 2 and Figure 3 The sliding guide 200 is shaped like a convex character. The sliding guide 200 is slidably connected to the slider 300 and the main frame 100. Compared with ordinary flat guides or V-shaped guides, the convex shape has a surface contact with the mating parts rather than a line contact. This can disperse the pressure when the slider 300 moves, reduce local wear, and reduce the risk of "jamming" caused by uneven force, thus ensuring the smoothness of the sliding process.

[0032] The upper and lower parts of the slider 300 are detachably connected and fixed by bolts. The upper and lower parts of the slider 300 are detachably connected by bolts. The slider 300 can be separated by loosening the bolts. The force motor connecting rod 420 or the displacement sensor extension rod 430 can be directly placed into the semi-circular groove 310, and then the bolts can be tightened to complete the clamping. By adjusting the tightening torque of the bolts, the clamping force of the upper and lower semi-circular grooves 310 on the workpiece can be flexibly controlled, which can ensure that the workpiece is stably fixed and prevent workpiece deformation caused by excessive tightness, thus taking into account both clamping stability and workpiece protection.

[0033] refer to Figure 3 and Figure 4 and Figure 5The clamping assembly 500 includes a pressure plate 510 for clamping the servo valve core assembly 400, a screw 520, and a nut-type clamping block 530 for clamping the pressure plate 510. The end of the pressure plate 510 furthest from the servo valve core assembly 400 is rotatably connected to the main frame 100 via a connecting shaft. The top end of the screw 520 passes through the main frame 100 and is threadedly connected to the threaded clamping block. The pressure plate 510 has a slot for the screw 520 to pass through. The pressure plate 510 clamps the servo valve core assembly 400 by rotating the threaded clamping block. The pressure plate 510 is pressed into the V-groove; it is rotatably connected to the main frame 100 at the end away from the servo valve core assembly 400, forming a "flip-top" structure. When loading and unloading the servo valve core assembly 400, simply loosen the nut pressure block 530 and lift the pressure plate 510 to quickly pick up and put down the component without completely disassembling the pressure assembly 500, which greatly improves the efficiency of the calibration operation. If the sensor position needs to be finely adjusted during the calibration process, the sensor can also be gently rotated or moved after loosening the nut pressure block 530, making the operation flexible.

[0034] The surface of the nut pressure block 530 is provided with a handle 540 for assisting the rotation of the nut pressure block 530. The handle 540 is fixedly connected to the nut pressure block 530 by bolts, so that the handle 540 can be disassembled. The handle 540 provides a convenient force point for rotating the nut pressure block 530. Compared with directly turning the nut pressure block 530 by hand, it is easier to achieve the action of tightening or loosening. Especially when it is necessary to repeatedly adjust the tightening force, it can significantly reduce the operation time and manpower consumption and improve the calibration efficiency.

[0035] The implementation principle of this application embodiment is as follows: In implementation, the servo valve core assembly 400, the force motor connecting rod 420, and the displacement sensor extension rod 430 are respectively placed in the V-groove 110 on the main frame 100 and the semi-circular groove 310 on the slider 300. The pressure plate 510 on the clamping assembly 500 is then depressed. The nut pressure block 530 is rotated, causing the nut pressure block to move downward, so that the pressure plate 510 clamps the servo valve core assembly 400. Then, the slider 300 and the main frame 100 move on the sliding guide rail 200 to detect the servo... The change in displacement of the servo valve core 410 on the valve core assembly 400 drives the displacement of the displacement sensor extension rod 430, thereby verifying whether the coaxiality of the direct drive force motor connecting rod 420 and the servo valve core assembly 400 is on the same axis. This achieves the purpose of calibrating the coaxiality of the direct drive force motor connecting rod 420 and the servo valve core assembly 400, avoiding the cumulative error caused by the superposition of multiple references, improving the reliability of the calibration results, and enabling the tooling to achieve precise positioning structure, convenient operation design and universal adjustment function.

[0036] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A fixture for calibrating the coaxiality of a direct-drive servo valve connecting rod and a servo valve spool, characterized in that, The device includes a main frame (100), a sliding guide rail (200) mounted on the main frame (100), a V-groove (110) mounted on the main frame (100), and two sliders (300) that can slide left and right along the sliding guide rail (200). The main frame (100) is fitted onto the sliding guide rail (200). The main frame (100) is provided with a servo valve core assembly (400) for calibration and a clamping assembly (500) for clamping the servo valve core assembly (400). The servo valve core assembly (400) is mounted on the V-groove (110). The sliders (300) are divided into upper and lower parts. Both the upper and lower parts of the sliders (300) are provided with semi-circular grooves (310), and the semi-circular grooves (310) can clamp the servo valve core assembly (400).

2. The coaxiality calibration fixture for the direct-drive servo valve connecting rod and servo valve core according to claim 1, characterized in that, The servo valve core assembly (400) includes a servo valve core (410), a force motor connecting rod (420), and a displacement sensor extension rod (430); one end of the force motor connecting rod (420) is connected to a force motor, and the other end of the force motor connecting rod (420) is connected to the servo valve core (410); one end of the displacement sensor extension rod (430) is connected to a displacement sensor, and the other end of the displacement sensor extension rod (430) is connected to the servo valve core (410).

3. The coaxiality calibration fixture for the direct-drive servo valve connecting rod and the servo valve core according to claim 1, characterized in that, The clamping assembly (500) includes a pressure plate (510) for clamping the servo valve core assembly (400), a screw (520), and a nut block (530) for clamping the pressure plate (510). The end of the pressure plate (510) away from the servo valve core assembly (400) is rotatably connected to the main frame (100). The top end of the screw (520) passes through the bottom end of the main frame (100) and is threadedly connected to the nut.

4. The coaxiality calibration fixture for the direct-drive servo valve connecting rod and servo valve core according to claim 3, characterized in that, The surface of the nut block (530) is provided with a handle (540) for assisting the rotation of the nut block (530), and the handle (540) and the nut block (530) are fixedly connected by bolts.

5. The coaxiality calibration fixture for the direct-drive servo valve connecting rod and the servo valve core according to claim 1, characterized in that, The upper and lower parts of the slider (300) are detachably connected, and the upper and lower parts of the slider (300) are connected and fixed by bolts.

6. The coaxiality calibration fixture for the direct-drive servo valve connecting rod and the servo valve core according to claim 1, characterized in that, The servo valve core (410) of the servo valve core assembly (400) is on the same straight line as the center line on the force motor connecting rod (420) and the displacement sensor extension rod (430).

7. The coaxiality calibration fixture for the direct-drive servo valve connecting rod and the servo valve core according to claim 1, characterized in that, The sliding guide rail (200) is convex in shape, and the sliding guide rail (200) is slidably connected to the slider (300) and the main frame (100).

8. The coaxiality calibration fixture for the direct-drive servo valve connecting rod and the servo valve core according to claim 1, characterized in that, The V-groove (110) on the main frame (100) and the semicircular groove (310) of the lower part of the slider (300) are on the same straight line.

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