A measuring device for detecting static and dynamic friction of a spool valve assembly

Abstract

The application belongs to the technical field of electro-hydraulic servo valve manufacturing and assembly, and discloses a measuring device for detecting static and dynamic friction of a slide valve assembly, which comprises a flexible adjustable slide valve assembly quick positioning and clamping mechanism, a force sensor-hinge group connecting mechanism and a motor-torsion wheel-pallet transmission mechanism which are sequentially assembled and connected together; through the quick positioning and clamping mechanism in the measuring device, the static and dynamic friction between slide valve assemblies of the same kind and different sizes can be quickly measured.

Description

Technical Field

[0001] This invention belongs to the field of electro-hydraulic servo valve manufacturing and assembly technology, and particularly relates to a measuring device for detecting the static and dynamic friction of a slide valve assembly. Background Technology

[0002] Electro-hydraulic servo valves are key components in electro-hydraulic servo control, offering advantages such as fast dynamic response, high control precision, and long service life. They are widely used in electro-hydraulic servo control systems in fields such as aviation, aerospace, shipbuilding, metallurgy, and chemical engineering. Within electro-hydraulic servo valves, whether the frictional force between the spool valve components is less than a threshold value directly affects the product's control performance.

[0003] In the power stage spool assembly of an electro-hydraulic servo valve, the magnitude of the frictional force between the valve core and the valve sleeve directly determines the resolution and hysteresis performance. In recent years, in the development of electro-hydraulic servo valve manufacturing and measurement and control technology, a common method for detecting normal dynamic friction between spool assemblies is to tilt the spool assembly at a certain angle, allowing the valve core to slide down flexibly under its own weight. This method is only a qualitative estimate; while simple, it cannot measure the numerical value of the frictional force, thus failing to quantitatively assess the quality of the spool assembly.

[0004] All methods for measuring friction use the principle of force balance. In existing technologies, regardless of the method used, human operation and evaluation are required, resulting in poor repeatability, consistency, and efficiency. Summary of the Invention

[0005] To quickly and accurately measure the dynamic friction force between valve assemblies, ensuring the flexibility of the valve core-valve sleeve relative movement during machining and assembly, and improving prediction resolution and hysteresis performance, this invention proposes a measuring device for detecting the static and dynamic friction forces of valve assemblies. This semi-automatic measuring device features a quick-positioning clamping mechanism, significantly improving clamping efficiency. Through this quick-positioning clamping mechanism, rapid measurement of the static and dynamic friction forces between valve assemblies of the same type but different sizes can be achieved. The measuring device utilizes a programmable motor controller and a high-precision force sensor to automate the measurement process and output the results.

[0006] To achieve the above objectives, the present invention employs the following technical solution.

[0007] A measuring device for detecting static and dynamic frictional forces of a slide valve assembly, the measuring device comprising a flexible adjustable slide valve assembly quick positioning and clamping mechanism 1-1, a force sensor-hinge group linking mechanism 1-2, and a motor-torsion wheel-support plate transmission mechanism 1-3, which are assembled and connected together in sequence.

[0008] The flexible adjustable slide valve assembly quick positioning and clamping mechanism 1-1 is used to clamp the slide valve assembly under test.

[0009] The force sensor-hinge assembly linking mechanism 1-2 is used to decouple forces in the vertical and horizontal directions;

[0010] The motor-torsion wheel-support plate transmission mechanism 1-3 is used to amplify the stroke of the slide valve assembly.

[0011] The features and further improvements of the technical solution of this invention are as follows:

[0012] (1) The flexible adjustable slide valve assembly quick positioning and clamping mechanism 1-1 consists of six parts: V-shaped positioning groove 2-1, spring screw 2-2, adjusting wedge block 2-3, axial locking wedge block 2-4, wedge-shaped pressure stop 2-5 and test connection seat 2-6;

[0013] The lower V-shaped positioning groove 2-1 completes the guiding positioning; tightening the spring screw 2-2 causes the adjusting wedge block 2-3 to sink, which in turn pushes the axial locking wedge block 2-4 to slide to the left. Under the combined action of the left wedge-shaped pressure stop edge 2-5, the valve sleeve 2-7 is fixed. The test connecting seat 2-6 is threaded to the valve core, with the valve core end face as the stop, and the first stepped hole on the valve core is centered.

[0014] (2) The test link seat 2-6 is screwed to the valve core 2-7 and locked to the hinge-sensor 1-2 by screws.

[0015] (3) The force sensor-hinge group linking mechanism 1-2 consists of a set of vertical direction degree of freedom unlocking bearing mechanism 3-1, a set of horizontal rotation direction degree of freedom unlocking bearing mechanism 3-2 and a high-precision force sensor 3-3.

[0016] One end of the set of vertical direction degree-of-freedom unlocking bearing mechanisms 3-1 is hinged to a set of horizontal rotation direction degree-of-freedom unlocking bearing mechanisms 3-2. The two ends of the high-precision force sensor 3-3 are respectively threaded to one end of the set of horizontal rotation direction degree-of-freedom unlocking bearing mechanisms 3-2 and one end of the set of vertical direction degree-of-freedom unlocking bearing mechanisms 3-1.

[0017] (4) The motor-torsion wheel-support plate transmission mechanism 1-3 consists of a linear guide rail and slider 4-1, a transmission support plate 4-2, a torsion wheel friction transmission mechanism 4-3 and a stepper motor;

[0018] The linear guide rail and slider 4-1 are fixed to the transmission plate 4-2 by screws. The inner wall of the square hole of the transmission plate 4-2 contacts the smooth ball extending from the torsion wheel friction transmission mechanism 4-3. When the ball rotates spirally with the torsion wheel friction transmission mechanism 4-3, it drives the transmission plate 4-2 to slide axially.

[0019] (5) The torsion wheel friction transmission mechanism 4-3 consists of a drive shaft bearing mounting seat 5-1, a driven wheel 5-2, a transmission ball fulcrum 5-3, a transmission box 5-4, a drive shaft 5-5, and a transmission shaft 5-6;

[0020] The drive shaft 5-5 is mounted on the drive shaft bearing mounting seat 5-1 via a bearing fixed shaft, passes through the through hole of the transmission box 5-4, and is fixedly connected at one end to the transmission shaft 5-6; the outer surface of the driven wheel 5-2 is in line contact with the surface of the drive shaft 5-5, and the inner surface of the driven wheel 5-2 is connected to the transmission box via a bearing; the transmission ball pivot 5-3 is fixed to the transmission box 5-4 by threads.

[0021] (6) When the drive shaft 5-5 rotates, the driven wheel 5-2 rotates spirally around the drive shaft and moves forward along the axis;

[0022] The displacement in the axial direction is used to position the drive mechanism, thereby converting the friction between the drive shaft 5-5 and the driven wheel 5-2 into a force for positioning.

[0023] (7) The torsion wheel friction transmission mechanism 4-3 includes: a drive shaft 5-5 and eight driven wheels 5-2. The eight driven wheels 5-2 are divided into two groups, front and rear, with four in each group, and are realized by deep groove ball bearings. The drive shaft 5-5 has a shaft diameter of φ12 mm, the driven wheels 5-2 have an outer diameter of φ10 mm, and the included angle θ is 0.03 rad.

[0024] This invention provides a measuring device for detecting the static and dynamic friction of a spool valve assembly. Through a combination of a horizontal V-groove and a wedge block, it enables rapid clamping and accurate positioning of the valve body and valve core assembly under test, ensuring workpiece placement and repeatability of test results. A torsion wheel transmission mechanism eliminates transmission vibrations generated during testing, ensuring smooth valve core movement without dead zones and guaranteeing accurate test results. A high-precision force sensor transmits precise test signals, facilitating reading and post-processing to output friction force values ​​and display images. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a measuring device for detecting static and dynamic friction forces of a slide valve assembly, provided in an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the structure of the quick positioning and clamping mechanism for the flexible adjustable slide valve assembly provided in an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the force sensor-hinge assembly linkage mechanism provided in an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the motor-torsion wheel-plate transmission mechanism provided in an embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of the torsion wheel friction transmission mechanism provided in an embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the torsion wheel friction transmission principle provided in an embodiment of the present invention;

[0031] Figure 7 This is a schematic diagram of the unfolded trajectory of the torsion wheel friction transmission provided in an embodiment of the present invention;

[0032] Figure 8 A schematic diagram of the displacement curve of the valve core driven by the measuring device and the static and dynamic friction force images collected by the sensor, provided in an embodiment of the present invention;

[0033] Among them, 1-1 is a quick positioning and clamping mechanism for a flexible adjustable slide valve assembly, 1-2 is a force sensor-hinge group linking mechanism, and 1-3 is a motor-torsion wheel-plate transmission mechanism.

[0034] 2-1 V-shaped positioning groove, 2-2 spring screw, 2-3 adjusting wedge block, 2-4 axial locking wedge block, 2-5 wedge-shaped pressure stop edge, 2-6 test connection seat, 2-7 valve core;

[0035] 3-1 A set of vertical direction degree-of-freedom unlocking bearing mechanisms; 3-2 A set of horizontal rotation direction degree-of-freedom unlocking bearing mechanisms; 3-3 A high-precision force sensor.

[0036] 4-1 Linear guide rail and slider, 4-2 Transmission support plate, 4-3 Torsion wheel friction transmission mechanism;

[0037] 5-1 Drive shaft bearing mounting base, 5-2 Driven wheel, 5-3 Transmission ball pivot, 5-4 Transmission box, 5-5 Drive shaft, 5-6 Transmission shaft. Detailed Implementation

[0038] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings.

[0039] To quickly and accurately measure the dynamic friction force between valve components, ensure the flexibility of the relative movement of the valve core and valve sleeve during processing and assembly, and improve prediction resolution and hysteresis performance, this invention designs a semi-automatic measuring device for detecting the static and dynamic friction forces of valve components.

[0040] The semi-automatic measuring device features a quick-positioning clamping mechanism, improving clamping efficiency. This mechanism enables rapid measurement of static and dynamic friction between valve assemblies of the same type but different sizes. The measuring device utilizes a programmable motor controller and a high-precision force sensor to automate the measurement process and output results.

[0041] The present invention provides a measuring device for detecting the static and dynamic friction of a slide valve assembly, which consists of three parts: a flexible adjustable slide valve assembly quick positioning and clamping mechanism (1-1), a force sensor-hinge group linking mechanism (1-2), and a motor-torsion wheel-support plate transmission mechanism (1-3). Figure 1 As shown.

[0042] The flexible adjustable slide valve assembly quick positioning and clamping mechanism (1-1) consists of six parts: a V-shaped positioning groove (2-1), a spring screw (2-2), an adjusting wedge block (2-3), an axial locking wedge block (2-4), a wedge-shaped pressure stop (2-5), and a test connection seat (2-6). Figure 2 As shown, the lower V-shaped positioning groove (2-1) completes the guiding positioning; tightening the spring screw (2-2) causes the adjusting wedge block (2-3) to sink, thereby pushing the axial locking wedge block (2-4) to slide to the left. Under the combined action of the left wedge-shaped pressure stop (2-5), the valve sleeve (2-7) is fixed. Its main clamping force is along the workpiece axis, with high axial rigidity and less affected by the clamping force. The clamping force can be controlled by rotating the spring screw (2-5) to adjust the limit stop. The test link seat (2-6) is threaded to the valve core (2-7), with the valve core end face as the stop and the first stepped hole on the valve core as the center. Tighten the test link seat (2-6) to the valve core (2-7), and place it in the fixture. The screws complete the connection and locking with the hinge-sensor (1-2).

[0043] The hinge-sensor (1-2) consists of a set of vertical direction degree-of-freedom unlocking bearing mechanisms (3-1), a set of horizontal rotation direction degree-of-freedom unlocking bearing mechanisms (3-2), and a high-precision force sensor (3-3). Figure 3 As shown, this ensures that when the transmission mechanism (1-3) and the valve core (2-7) move together, no measurement error will be introduced due to the axial deviation angle.

[0044] One end of a set of vertical direction degree-of-freedom unlocking bearing mechanisms (3-1) is hinged to a set of horizontal rotation direction degree-of-freedom unlocking bearing mechanisms (3-2). The two ends of a high-precision force sensor (3-3) are respectively threaded to one end of a set of horizontal rotation direction degree-of-freedom unlocking bearing mechanisms (3-2) and one end of a set of vertical direction degree-of-freedom unlocking bearing mechanisms (3-1).

[0045] The motor-torsion wheel-support mechanism (1-3) consists of a linear guide rail and slider (4-1), a transmission plate (4-2), a torsion wheel friction transmission mechanism (4-3), and a stepper motor. Figure 4 As shown, the torsion wheel friction transmission mechanism (4-1) is the key working part.

[0046] The linear guide and slider (4-1) are fixed to the transmission plate (4-2) by screws. The inner wall of the square hole of the transmission plate (4-2) contacts the smooth ball protruding from the torsion wheel friction transmission mechanism (4-3). When the ball rotates spirally with the torsion wheel friction transmission mechanism (4-3), it drives the transmission plate (4-2) to slide axially.

[0047] like Figure 5 As shown, the drive shaft bearing mounting base (5-1), driven wheel (5-2), transmission ball pivot (5-3), transmission box (5-4), drive shaft (5-5), and transmission shaft (5-6) constitute a torsion wheel friction transmission mechanism (4-3).

[0048] The drive shaft (5-5) is mounted on the drive shaft bearing mounting seat (5-1) via a bearing fixed shaft, passes through the through hole of the transmission box (5-4), and one end is fixedly connected to the transmission shaft (5-6); the outer surface of the driven wheel (5-2) is in line contact with the surface of the drive shaft (5-5), and the inner surface of the driven wheel (5-2) is connected to the transmission box via a bearing; the transmission ball pivot (5-3) is fixed to the transmission box (5-4) by threads.

[0049] The driven wheel (5-2) and the driving shaft (5-5) make contact at a small angle. The layout of the driven wheel (5-2) and the driving shaft (5-5) is shown in [reference needed]. Figure 6 When the drive shaft (5-5) rotates, the driven wheel (5-2) rotates helically around the drive shaft and moves forward along the axial direction. The displacement in the axial direction is used to position the drive mechanism, thus converting the frictional force between (5-5) and (5-2) into a force used for positioning. Figure 7 The diagram shows the unfolded trajectory of the driven wheels. This device employs a torsion wheel friction transmission mechanism, consisting of a driving shaft (5-5) and eight driven wheels (5-2), with two sets of four driven wheels each, implemented using deep groove ball bearings. The driving shaft (5-5) has a diameter of φ12, and the driven wheels (5-2) have an outer diameter of φ10. The included angle θ is 0.03 rad. The significantly increased reduction ratio improves the positioning resolution accuracy and start-stop characteristics of the transmission mechanism. The positioning mechanism also exhibits high rigidity and smooth forward and reverse strokes without dead zones.

[0050] like Figure 8 The diagram shows the displacement curve of the valve core driven by the measuring device provided in this embodiment of the invention and the static and dynamic friction force images collected by the sensor.

[0051] This invention has been applied to product development with good results. The device has high measurement efficiency and can accurately measure the static and dynamic friction forces between valve components. It has played a good role in screening finished valve components, improving resolution, and predicting hysteresis performance. The measured friction force of qualified valve components is <0.2N.

[0052] This invention provides a measuring device and method for detecting static and dynamic friction forces in a spool valve assembly. Through a structure combining a horizontal V-groove and a wedge block, it achieves rapid clamping and accurate positioning of the valve body and valve core assembly under test, ensuring workpiece placement and repeatability of test results. A torsion wheel transmission mechanism eliminates transmission vibrations generated during the test, ensuring smooth valve core movement without dead zones and guaranteeing the accuracy of the test results. A high-precision force sensor transmits accurate test signals, facilitating reading and post-processing to output friction force values ​​and display images.

Claims

1. A measuring device for detecting the static and dynamic friction forces of a slide valve assembly, characterized in that, The measuring device includes a flexible adjustable slide valve assembly quick positioning and clamping mechanism (1-1), a force sensor-hinge group linking mechanism (1-2), and a motor-torque wheel-plate transmission mechanism (1-3) that are assembled and connected together in sequence. The flexible adjustable slide valve assembly quick positioning and clamping mechanism (1-1) is used to clamp the slide valve assembly under test. The force sensor-hinge assembly link mechanism (1-2) is used to decouple forces in the vertical and horizontal directions; The motor-torsion wheel-support plate transmission mechanism (1-3) is used to amplify the stroke of the slide valve assembly; The flexible adjustable slide valve assembly quick positioning and clamping mechanism (1-1) consists of six parts: V-shaped positioning groove (2-1), spring screw (2-2), adjusting wedge block (2-3), axial locking wedge block (2-4), wedge pressure stop edge (2-5), and test connection seat (2-6); The lower V-shaped positioning groove (2-1) completes the guiding positioning; tighten the spring screw (2-2), drive the adjusting wedge block (2-3) to sink, and then push the axial locking wedge block (2-4) to slide to the left. Under the joint action of the left wedge pressure stop edge (2-5), the valve sleeve (2-7) is fixed. The test link seat (2-6) is engaged with the valve core through the thread, with the valve core end face as the stop, and the first stepped hole on the valve core is centered.

2. The measuring device for detecting static and dynamic friction forces of a slide valve assembly according to claim 1, characterized in that, The test connector (2-6) is screwed tightly to the valve core, and the connection and locking with the force sensor-hinge assembly (1-2) is completed by screws.

3. The measuring device for detecting static and dynamic friction forces of a slide valve assembly according to claim 2, characterized in that, The force sensor-hinge assembly link mechanism (1-2) consists of a set of vertical direction degree-of-freedom unlocking bearing mechanisms (3-1), a set of horizontal rotation direction degree-of-freedom unlocking bearing mechanisms (3-2), and a high-precision force sensor (3-3). One end of the set of vertical direction degree of freedom unlocking bearing mechanism (3-1) is hinged to a set of horizontal rotation direction degree of freedom unlocking bearing mechanism (3-2), and the two ends of the high-precision force sensor (3-3) are respectively threaded to one end of the set of horizontal rotation direction degree of freedom unlocking bearing mechanism (3-2) and one end of the set of vertical direction degree of freedom unlocking bearing mechanism (3-1).

4. The measuring device for detecting static and dynamic friction forces of a slide valve assembly according to claim 3, characterized in that, The motor-torsion wheel-support plate transmission mechanism (1-3) consists of a linear guide rail and slider (4-1), a transmission support plate (4-2), a torsion wheel friction transmission mechanism (4-3), and a stepper motor; The linear guide rail and slider (4-1) are fixed to the transmission plate (4-2) by screws. The inner wall of the square hole of the transmission plate (4-2) contacts the smooth ball extending from the torsion wheel friction transmission mechanism (4-3). When the ball rotates spirally with the torsion wheel friction transmission mechanism (4-3), it drives the transmission plate (4-2) to slide axially.

5. A measuring device for detecting static and dynamic friction forces in a slide valve assembly according to claim 4, characterized in that, The torsion wheel friction transmission mechanism (4-3) consists of a drive shaft bearing mounting seat (5-1), a driven wheel (5-2), a transmission ball pivot (5-3), a transmission box (5-4), a drive shaft (5-5), and a transmission shaft (5-6); The drive shaft (5-5) is mounted on the drive shaft bearing mounting seat (5-1) via a bearing fixed shaft, passes through the through hole of the transmission box (5-4), and is fixedly connected at one end to the transmission shaft (5-6); the outer surface of the driven wheel (5-2) is in line contact with the surface of the drive shaft (5-5), and the inner surface of the driven wheel (5-2) is connected to the transmission box via a bearing; the transmission ball pivot (5-3) is fixed to the transmission box (5-4) by threads.

6. A measuring device for detecting static and dynamic friction forces in a slide valve assembly according to claim 5, characterized in that, When the drive shaft (5-5) rotates, the driven wheel (5-2) rotates spirally around the drive shaft and moves forward along the axial direction; The displacement in the axial direction is used to position the drive mechanism, thereby converting the friction between the drive shaft (5-5) and the driven wheel (5-2) into a force for positioning.

7. A measuring device for detecting static and dynamic friction forces in a slide valve assembly according to claim 6, characterized in that, The torsion wheel friction transmission mechanism (4-3) includes: a drive shaft (5-5) and 8 driven wheels (5-2). The 8 driven wheels (5-2) are divided into two groups of 4 in each group, which are realized by deep groove ball bearings. The drive shaft (5-5) has a shaft diameter of φ12 mm and the driven wheels (5-2) have an outer diameter of φ10 mm.

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