Method for machining an integrated quartz sensitive element

Abstract

This application discloses a machining method for an integrated quartz sensing element. Using quartz rod as a blank, two bosses are machined by radial feed of a cutting tool. Ultrasonic assistance is used throughout the machining process to ensure that the bosses have good symmetry and high precision. When machining the central countersunk hole on the boss, the cutting tool is gradually reduced in diameter and fed layer by layer. The cutting tool is always coaxial with the boss, so that the boss is only subjected to vertical force during machining and is not affected by horizontal force, thus ensuring low stress machining. The quartz sensing element machined by this method has good integrity and improved machining quality. Compared with traditional assembled sensing elements, the integrated quartz sensing element improves the accuracy of use.

Description

Technical Field

[0001] This disclosure relates to the field of precision manufacturing technology for high-precision optical components, specifically to a machining method for an integrated quartz sensing element. Background Technology

[0002] Quartz flexible accelerometers, as core instruments for measuring linear acceleration of sensitive carriers, are equipped in inertial navigation systems across land, sea, air, and space. However, due to the use of various heterogeneous materials in their core sensing elements, factors such as material processing stress release, creep, and aging can cause the instrument's output parameters to drift with changes in time and temperature, ultimately affecting the accuracy of the inertial navigation system. Especially with the development of temperature-controlled strapdown systems, temperature-induced output variations account for a large proportion of accelerometer parameter drift; therefore, the requirements for the temperature stability of quartz flexible accelerometers are becoming increasingly stringent.

[0003] The sensing element is the core component of a quartz accelerometer. Conventional, split-type sensing elements consist of several parts made of different materials bonded together to achieve capacitive sensing and torque application. While the individual parts are relatively easy to manufacture, the overall accuracy of the assembled element cannot meet current requirements due to the bonded assembly. A fully integrated quartz sensing element, however, can achieve a complex three-dimensional suspension structure, replacing the traditional split structure and reducing deformation by two orders of magnitude. This is expected to fundamentally solve the full-temperature performance problem of quartz accelerometers. The integrated sensing element has a thin-walled structure, high precision requirements, and is difficult to manufacture; currently, there are no suitable manufacturing methods. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a machining method for an integrated quartz sensing element.

[0005] In a first aspect, this application provides a machining method for an integrated quartz sensing element, wherein the sensing element includes two symmetrical and coaxially arranged bosses, a connecting plate is integrally formed between the two bosses, and a central countersunk hole is provided on the sidewalls of the two bosses that are far apart from each other. A central through hole is provided at the center of the connecting plate, and the two ends of the central through hole are respectively connected to the two central countersunk holes.

[0006] The processing method includes:

[0007] A workpiece blank is machined on a quartz rod, and the workpiece blank and the quartz rod are separated. The workpiece blank includes two symmetrical bosses and a connecting plate located between the two bosses. The workpiece blank is clamped, and one of the bosses is exposed. The other boss is cured with an adhesive. A central through hole and a central countersunk hole are machined on the exposed boss. The inner diameter of the central through hole is set to the sixth length, and the inner diameter of the central countersunk hole is set to the fourth length.

[0008] First, a hollow diamond drill bit with an outer diameter of six lengths is used to axially feed and machine the center through hole at the center of the exposed boss. Then, a hollow diamond drill bit with an outer diameter of four lengths is used to coaxially feed and machine the center countersunk hole on the boss. Then, the size of the hollow diamond drill bit is gradually reduced and fed axially along the boss, leaving a machining allowance. The machined center countersunk hole is then finished. Finally, the workpiece blank is flipped over and clamped, and a center countersunk hole is machined on another boss. Ultrasonic assistance is used throughout the machining process.

[0009] According to the technical solution provided in the embodiments of this application, the axial length of the integrated sensing element is set as a first length, the axial length of the boss is set as a second length, the thickness of the connecting plate is set as a third length, and the outer diameter of the boss is set as a fifth length.

[0010] The machining method is applied to a machine tool, which has a rotatable worktable, a fixture on the worktable for clamping the workpiece, and a cutting tool for machining.

[0011] According to the technical solution provided in the embodiments of this application, quartz rod is selected as the blank rod. An internal expansion fixture is used to clamp the blank rod and install it on the worktable. Then, the axis of the electroplated diamond end mill is made perpendicular to the axis of the blank rod. The machine tool is started to rotate the worktable and the electroplated diamond end mill, and the feed of the electroplated diamond end mill is controlled. The feed depth is the difference between the outer diameter of the reference surface and the fifth length. By operating the electroplated diamond end mill to move axially along the outer diameter of the reference surface, the axial length of the machined boss is made to be the second length, thus completing the machining of the first boss. Ultrasonic assisted machining is used throughout the machining process.

[0012] According to the technical solution provided in the embodiments of this application, after machining the first boss, the electroplated diamond end mill is moved away from the boss, and the boss and the blank are cured with adhesive. The electroplated diamond end mill is moved axially along the outer circle of the reference surface, leaving a third length as a connecting plate. The part of the outer circle of the reference surface away from the worktable is machined. The electroplated diamond end mill is fed radially along the outer circle of the reference surface, and the feed depth is the difference between the outer circle diameter of the reference surface and the fifth length. By operating the electroplated diamond end mill to move axially along the outer circle of the reference surface, the axial length of the machined boss is made to be the second length, thus completing the machining of the second boss. The machining of the workpiece blank is thus completed. Ultrasonic assisted machining is used throughout the machining process.

[0013] According to the technical solution provided in the embodiments of this application, the connection between the first boss and the blank bar is cut, the workpiece blank is removed, the cured adhesive is melted, the workpiece blank is cleaned, and then the inner expansion fixture and the remaining blank bar are removed from the machine tool worktable.

[0014] According to the technical solution provided in the embodiments of this application, a cylindrical glass with parallel double sides is selected. A positioning countersunk hole matching the size of the boss is machined at the center of one end face of the cylindrical glass. Then, the cylindrical glass is placed on the surface of the worktable, so that the end face where the positioning countersunk hole is located is far away from the worktable. One boss of the workpiece blank is placed in the positioning countersunk hole to ensure that the workpiece blank and the cylindrical glass are coaxial. The workpiece blank and the cylindrical glass are bonded and cured with adhesive. A washer is set on the end face of the connecting plate. The washer is pressed by a clamp, so that the workpiece blank and the cylindrical glass that are cured together are pressed against the worktable, and the cylindrical glass and the worktable are coaxial.

[0015] According to the technical solution provided in the embodiments of this application, a hollow diamond drill bit with an outer diameter of the sixth length is used to drill a hole along the axial direction of the workpiece blank at the center of the boss exposed outside the cylindrical glass. It is not necessary to drill through the workpiece blank. The drilling depth is greater than the sum of the second length and the third length, but less than the first length. At this time, the inner diameter of the central through hole is the sixth length. Then, a hollow diamond drill bit with an outer diameter of the fourth length is used to coaxially process the central countersunk hole on the boss. The drilling depth is the second length. Then, the outer diameter of the hollow diamond drill bit is gradually reduced, and drilling is performed in sequence. The drilling depth is always the second length, and a machining allowance is reserved. Finally, the central countersunk hole is precision machined. Thus, the machining of the central countersunk hole of the first boss is completed. The entire machining process uses ultrasonic-assisted machining.

[0016] According to the technical solution provided in the embodiments of this application, since the drilling depth of the central through hole is greater than the sum of the second length and the third length and less than the first length, after the central countersunk hole machining on the two bosses is completed, the two ends of the central through hole are connected to the two central countersunk holes.

[0017] According to the technical solution provided in the embodiments of this application, the clamps restrict the connecting plate and cylindrical glass, the adhesive is melted, the processed integrated quartz sensing element is removed and cleaned, thus completing the processing of the integrated quartz sensing element.

[0018] According to the technical solution provided in the embodiments of this application, the processing method includes the following steps:

[0019] S1. Using quartz rod as blank, grind and polish the outer circle of the blank as the reference surface for mounting and processing, so that the reference surface meets the required size and accuracy requirements.

[0020] S2. Use an internal expansion fixture to clamp the blank bar stock, completely expose the reference surface to the outside of the internal expansion fixture, and install the fixture on the surface of the machine tool table using a clamp, so that the outer circle of the reference surface is coaxial with the machine tool table.

[0021] S3. Start the machine tool to rotate the worktable, use an electroplated diamond end mill to feed radially to machine two symmetrical bosses, and reserve a third length between the two bosses as a connecting plate. Ultrasonic assisted machining is used throughout the process.

[0022] S4. Cut the finished workpiece blank and bar stock to separate the workpiece blank and bar stock, and remove the inner expansion fixture.

[0023] S5. Select cylindrical glass and machine a positioning countersunk hole at the center of one end face of the cylindrical glass to accommodate the boss. Place the cylindrical glass on the worktable surface and place one of the bosses of the workpiece blank in the positioning countersunk hole. Use adhesive to bond and cure the workpiece blank and the cylindrical glass. Then, use a clamp to install the cylindrical glass on the worktable surface.

[0024] S6. Using a hollow diamond drill bit with an outer diameter of the sixth length, drill a central through hole along the axial direction of the workpiece blank at the center of the boss exposed outside the cylindrical glass. Then, use a hollow diamond drill bit with an outer diameter of the fourth length to coaxially machine a central countersunk hole on the boss. Gradually reduce the outer diameter of the hollow diamond drill bit and drill holes in sequence. Finally, finish machine the central countersunk hole. Ultrasonic-assisted machining is used throughout the entire machining process.

[0025] S7. Release the clamp from the workpiece blank and cylindrical glass, melt the adhesive and clean the workpiece blank and cylindrical glass. Place the boss with the machined center countersunk hole into the positioning countersunk hole of the cylindrical glass. Use adhesive again to bond and cure the workpiece blank and cylindrical glass. By setting a washer on the connecting plate, and then clamping the washer again, the workpiece blank and cylindrical glass that are cured together are pressed against the worktable, and the cylindrical glass and the worktable are coaxial. Then repeat step S6.

[0026] In summary, this technical solution discloses a machining method for an integrated quartz sensing element. Because the entire machining process is ultrasonically assisted, the sensing element produced by this method can be machined with high precision using cutting tools. The resulting integrated quartz sensing element has good integrity, ensuring consistency in the size and precision of the two bosses. Unlike traditional adhesive-assembled sensing elements, the integrated quartz sensing element produced by this method has stronger adaptability and higher precision.

[0027] In this method, the drilling depth of the machining center through hole is greater than the sum of the boss length and the connecting plate thickness and less than the workpiece length, so that only one boss needs to be drilled, instead of drilling on both bosses separately. After the two center countersunk holes are machined, the two ends of the center through hole are naturally connected to the center countersunk hole, which improves the machining efficiency.

[0028] By employing a gradually decreasing tool size in the machining center countersinking process, the required inner diameter of the countersinking hole can be machined during the first drilling operation. Subsequently, the outer diameter of the tool is gradually reduced, causing the residual portion inside the countersinking hole to decrease progressively. Furthermore, the tool is fed perpendicularly along the machined surface during each machining operation, ensuring that the workpiece blank is subjected to forces only in the vertical direction and not in the horizontal direction. This enables high-precision and low-stress machining, improving machining quality. The adhesive provides support during machining, preventing damage to the workpiece blank due to stress. Attached Figure Description

[0029] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0030] Figure 1 This is a schematic diagram of the machining steps for an integrated quartz sensing element.

[0031] Figure 2 This is a schematic diagram of an integrated quartz sensing element.

[0032] Figure 3 This is a schematic diagram of the internal expansion tooling clamping.

[0033] Figure 4 A schematic diagram of the mounting of cylindrical glass.

[0034] The following are labels in the diagram: 1. Workpiece blank; 2. Internal expansion fixture; 3. Worktable; 4. Connecting plate; 5. Washer; 6. Fixture; 7. Cylindrical glass; 8. Boss; 9. Center countersunk hole; 10. Center through hole; 11. Positioning countersunk hole; 12. Blank bar stock. Detailed Implementation

[0035] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0036] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] Example 1

[0038] Please refer to Figure 1A machining method for an integrated quartz sensing element is applied to a machine tool. The machine tool has a rotatable worktable 3. The surface of the worktable 3 is provided with a clamp 6 that can press the workpiece. The clamp 6 can make the workpiece abut against the worktable 3. This is the prior art and is not specifically limited.

[0039] The integrated sensing element has a thin-walled structure, so it requires high machining precision. For high-precision thin-walled brittle integrated quartz sensing elements, ultrasonic-assisted machining and special mounting and distributed drilling and milling processes are used to achieve high-precision and low-stress machining of integrated sensing elements.

[0040] Ultrasonic machining is a machining method that uses ultrasonic vibrations on the end face of a tool to process a workpiece, resulting in high machining accuracy.

[0041] The clamping fixture is an internal expansion fixture 2, which has multiple jaws evenly arranged in the circumference. There is a clamping space between the multiple jaws. When the workpiece is not clamped, the multiple jaws are close to each other. When the workpiece is clamped, the workpiece is placed in the clamping space. The jaws can clamp the workpiece because they tend to move closer together. Its advantage is that it is easy to make the workpiece and the internal expansion fixture 2 coaxial.

[0042] The integrated sensing element includes two symmetrical and coaxially arranged bosses 8, with a connecting plate 4 between the two bosses 8. The sidewalls of the two bosses 8 that are far apart are provided with central countersunk holes 9. The connecting plate 4 has a central through hole 10 at its center, and the two ends of the central through hole 10 are respectively connected to the two central countersunk holes 9.

[0043] The axial length of the integrated sensing element is set as the first length, the axial length of the boss 8 is set as the second length, the thickness of the connecting plate 4 is set as the third length, the inner diameter of the central countersunk hole 9 is set as the fourth length, the outer diameter of the boss 8 is set as the fifth length, and the inner diameter of the central through hole 10 is set as the sixth length.

[0044] The machining method includes the following steps:

[0045] S1. Using quartz rod as blank, grind and polish the outer circle of the blank as the reference surface for mounting and processing, so that the reference surface meets the required size and accuracy requirements.

[0046] S2. Use the internal expansion fixture 2 to clamp the blank bar 12, and expose the reference surface completely outside the internal expansion fixture 2. Install the fixture on the surface of the machine tool table 3 through the clamp 6, so that the outer circle of the reference surface is coaxial with the machine tool table 3.

[0047] S3. Start the machine tool to rotate the worktable 3, use an electroplated diamond end mill to radially feed and machine two symmetrical bosses 8, and reserve a third length between the two bosses 8 as a connecting plate 4. Ultrasonic assisted machining is used throughout the process.

[0048] Specifically, the machine tool is started to rotate the worktable 3, and the part of the outer circle of the reference surface near the worktable 3 is machined using an electroplated diamond end mill. The electroplated diamond end mill is fed radially along the outer circle of the reference surface, and the feed depth is the difference between the outer circle diameter of the reference surface and the fifth length. By operating the electroplated diamond end mill to move axially along the outer circle of the reference surface, the axial length of the machined boss 8 is the second length, thus completing the machining of the first boss 8.

[0049] Then, the electroplated diamond end mill is moved away from the boss 8, and the boss 8 and the blank 12 are cured with adhesive. The electroplated diamond end mill is moved axially along the outer circle of the reference surface, leaving a third length as a connecting plate 4. The part of the outer circle of the reference surface away from the worktable 3 is machined. The electroplated diamond end mill is fed radially along the outer circle of the reference surface, and the feed depth is the difference between the outer circle diameter of the reference surface and the fifth length. By operating the electroplated diamond end mill to move axially along the outer circle of the reference surface, the axial length of the machined boss 8 is made to be the second length. The machining of the second boss 8 is thus completed, and the machining of the workpiece blank 1 is completed. Ultrasonic assisted machining is used throughout the machining process. The type of adhesive, such as melted rosin and paraffin, plays a supporting and stabilizing role, which can prevent the workpiece blank 1 from breaking during machining.

[0050] S4. Cut the finished workpiece blank 1 and the bar stock to separate the workpiece blank 1 and the blank bar stock 12, and remove the inner expansion fixture 2.

[0051] Specifically, a cutter is used to cut the connection between the first boss 8 and the blank bar 12, separating the workpiece blank 1 and the blank bar 12. The workpiece blank 1 is removed, and the cured adhesive is melted and cleaned. Then, the inner expansion fixture 2 and the remaining blank bar 12 are removed from the machine tool worktable 3. The type of cutter is, for example, a diamond saw blade.

[0052] S5. Select cylindrical glass 7 and machine a positioning countersunk hole 11 at the center of one end face of cylindrical glass 7 to accommodate the boss 8. Place cylindrical glass 7 on the surface of worktable 3 and place one boss 8 of workpiece blank 1 in the positioning countersunk hole 11. Use adhesive to bond and cure workpiece blank 1 and cylindrical glass 7. Then install cylindrical glass 7 on the surface of worktable 3 using clamp 6.

[0053] Specifically, a cylindrical glass 7 with parallel sides is selected. A positioning countersunk hole 11, matching the size of the boss 8, is machined at the center of one end face of the cylindrical glass 7. The cylindrical glass 7 is then placed on the surface of the worktable 3, with the end face containing the positioning countersunk hole 11 away from the worktable 3. One boss 8 of the workpiece blank 1 is placed in the positioning countersunk hole 11, ensuring that the workpiece blank 1 and the cylindrical glass 7 are coaxial. The workpiece blank 1 and the cylindrical glass 7 are bonded and cured with adhesive. A washer 5 is set on the upper end face of the connecting plate 4. The washer 5 is pressed against the worktable 3 by the clamp 6, thereby ensuring that the workpiece blank 1 and the cylindrical glass 7 are pressed against the worktable 3 and that the cylindrical glass 7 and the worktable 3 are coaxial. The type of washer 5, for example, is a polytetrafluoroethylene washer. The washer 5 on the upper end face of the connecting plate 4 can ensure that the connecting plate 4 will not be damaged by the clamp 6, thereby ensuring that the workpiece blank 1 is not damaged. The adhesive can play a supporting role.

[0054] S6. Using a hollow diamond drill bit with an outer diameter of the sixth length, drill a central through hole 10 along the axis of the workpiece blank 1 at the center of the boss 8 exposed outside the cylindrical glass 7. Then, use a hollow diamond drill bit with an outer diameter of the fourth length to coaxially machine a central countersunk hole 9 on the boss 8. Then, gradually reduce the outer diameter of the hollow diamond drill bit and drill holes in sequence. Finally, perform finishing on the central countersunk hole 9. Ultrasonic-assisted machining is used throughout the machining process.

[0055] Specifically, a hollow diamond drill bit with an outer diameter of the sixth length is used to drill a hole along the axial direction of the workpiece blank 1 at the center of the boss 8 exposed outside the cylindrical glass 7. It is not necessary to drill through the workpiece blank 1. The drilling depth is greater than the sum of the second and third lengths and less than the first length. At this time, the inner diameter of the central through hole 10 is the sixth length. Then, a hollow diamond drill bit with an outer diameter of the fourth length is used to coaxially machine the central countersunk hole 9 on the boss 8. The drilling depth is the second length. Then, the outer diameter of the hollow diamond drill bit is gradually reduced and drilling is performed in sequence. The drilling depth is always the second length, and a machining allowance is reserved. Finally, a sintered diamond tool is used to finish machine the central countersunk hole 9. Thus, the machining of the central countersunk hole 9 of the first boss 8 is completed. Ultrasonic assistance is used for machining throughout the process. At the same time, due to the supporting effect of the adhesive, the axial force from the tool can be reduced throughout the machining of the central countersunk hole 9, which can prevent the bottom of the workpiece blank 1 from being suspended and causing the connecting plate 4 to break. This can protect the workpiece blank 1.

[0056] S7. Release the clamp 6 from the workpiece blank 1 and cylindrical glass 7, melt the adhesive and clean the workpiece blank 1 and cylindrical glass 7. Place the boss 8 with the machined center countersunk hole 9 into the positioning countersunk hole 11 of the cylindrical glass 7. Use adhesive again to bond and solidify the workpiece blank 1 and cylindrical glass 7. By setting a washer 5 on the connecting plate 4, and then clamping the clamp 6 against the washer 5 again, the workpiece blank 1 and cylindrical glass 7 solidified together are pressed against the worktable 3, and the cylindrical glass 7 and the worktable 3 are coaxial. Then repeat step S6.

[0057] It should be noted that, since the drilling depth of the center through hole 10 in step S6 is greater than the sum of the second length and the third length but less than the first length, after step S7 is completed, the center countersunk holes 9 on both bosses 8 can be connected to the center through hole 10.

[0058] The implementation process of this invention is now described using an integrated sensitive element with an outer diameter of φ20mm, an outer diameter of boss 8 of φ10mm, an inner diameter of boss 8 of φ9mm, a depth of central countersunk hole 9 of 4mm, and an inner diameter of central through hole 10 of φ1.6mm as an example.

[0059] Take a quartz rod as a blank, grind and polish one end of the outer circle of the blank, and use the ground and polished outer circle as the reference surface for mounting and processing. The outer circle of the reference surface to be ground and polished should meet the dimensional tolerance of ±0.01mm and the cylindricity of less than 0.005mm.

[0060] Use the internal expansion fixture 2 for clamping. Specifically, insert the end of the blank bar 12 away from the reference surface into the clamping space, with the reference surface exposed outside the internal expansion fixture 2. The straight-line distance from the end of the reference surface near the internal expansion fixture 2 to the end face of the internal expansion fixture 2 should be greater than 20mm. Place the internal expansion fixture 2 on the machine tool worktable 3 and clamp it with the fixture 6. Use a lever dial indicator to align the rotation center of the blank bar 12, ensuring that the coaxiality between the outer circle of the reference surface and the worktable 3 is less than 0.002mm.

[0061] Roughing is performed using an electroplated diamond end mill, ensuring that the axis of the electroplated diamond end mill is perpendicular to the axis of the outer circle of the reference surface. The machine tool is started, and the worktable 3 rotates simultaneously with the electroplated diamond end mill. The machine tool cooling and ultrasonic auxiliary functions are turned on. The speed of the worktable 3 is set to 500 r / min, and the speed of the electroplated diamond end mill is set to 20000 r / min. First, the outer circle of the reference surface near the worktable 3 is machined. The electroplated diamond end mill is fed vertically, with a feed distance equal to the outer circle diameter of the reference surface minus the outer diameter of the boss 8. The electroplated diamond end mill is then fed axially along the outer circle of the reference surface, making the length of the boss 8 4 mm. This creates the first boss 8, leaving a finishing allowance of 0.1 mm. The electroplated diamond end mill is then moved radially away from the boss 8. The sintered diamond tool is then replaced for finishing, ensuring that the axis of the sintered diamond tool is perpendicular to the axis of the blank bar 12. A layer-by-layer feed method is used, with each layer having a machining dimension of 0.002 mm.

[0062] After the first boss 8 is processed, it is wrapped with tracing paper and then filled with melted rosin and paraffin wax for bonding. After the rosin and paraffin wax solidify, they can provide support and prevent the boss 8 from being damaged during subsequent processing.

[0063] Then, the electroplated diamond end mill is moved to rough machine the part of the outer circle of the reference surface away from the worktable 3, which is the second boss 8. At this time, a third length needs to be reserved between the two bosses 8 as a connecting plate 4. The third length is provided by the drawing.

[0064] Restart the machine tool to rotate the worktable 3 and the electroplated diamond end mill. Feed the electroplated diamond end mill vertically and operate it to feed along the outer circle of the reference surface to make the length of the boss 8 4mm. This will produce the second boss 8, with a finishing allowance of 0.1mm.

[0065] Replace with sintered diamond tools for finishing, ensuring that the axis of the sintered diamond tool is perpendicular to the axis of the blank bar 12. Use a layer-by-layer feed method, with each layer having a machining dimension of 0.002mm, and the workpiece blank 1 is thus produced.

[0066] After finishing, stop the machine tool, turn off the machine tool cooling and ultrasonic auxiliary functions, use a diamond saw blade to cut the connection between the blank bar 12 and the first boss 8, cut off the workpiece blank 1, then melt the rosin and paraffin, clean the workpiece blank 1, and inspect the workpiece blank 1. It should meet the requirement that the parallelism of the plane containing the tangents at both ends of any diameter of the boss 8 is less than 0.001mm. After that, remove the internal expansion fixture 2 and the remaining blank bar 12 from the machine tool worktable 3.

[0067] Select a cylindrical glass 7 with a parallelism of less than 0.001 mm on both sides. Use a milling cutter to machine a positioning countersunk hole 11 at the center of one end face of the cylindrical glass 7. The diameter of the positioning countersunk hole 11 is 0.1 mm larger than the outer diameter of the boss 8, and the depth is more than 1 mm larger than the axial length of the boss 8. After cleaning the cylindrical glass 7, place one of the bosses 8 of the workpiece blank 1 into the positioning countersunk hole 11 so that the workpiece blank 1 and the cylindrical glass 7 are in contact. Place the cylindrical glass 7 in the center of the worktable 3 and use a lever dial indicator to adjust the workpiece blank 1 so that the runout of the end face of the workpiece blank 1 is less than 0.002 mm. Then use melted rosin and paraffin adhesive to cure the cylindrical glass 7 and the workpiece blank 1. Use a polytetrafluoroethylene gasket 5 to protect the upper surface of the connecting plate 4 of the workpiece blank 1. The clamp 6 presses against the polytetrafluoroethylene gasket 5 to fix the cylindrical glass 7 and the workpiece blank 1.

[0068] Turn on the machine tool cooling and ultrasonic auxiliary functions. First, use a hollow diamond drill bit with an outer diameter of φ1.6mm to machine a central through hole 10 along the axial direction at the center of the workpiece blank 1. It is not necessary to penetrate the workpiece blank 1, but the distance from the bottom of the drilled hole to the bottom surface of the connecting plate 4 must be more than 2mm. Then, use a hollow diamond drill bit with a wall thickness of 1mm to machine a central countersunk hole 9 on the boss 8 exposed outside the positioning countersunk hole 11, ensuring that the hollow diamond drill bit and the workpiece blank 1 are coaxial. Then, use hollow diamond drill bits with outer diameters of φ9±0.01mm, φ7.5±0.01mm, φ5.5±0.01mm and φ3.5±0.01mm to perform drilling operations along the axial direction of the workpiece blank 1 in sequence. The drilling depth of the central countersunk hole 9 is 4mm. When using the above four specifications of hollow diamond drill bits... After drilling with a diamond drill bit, the interior of the boss 8 exhibits multiple annular thin walls. These thin walls are eliminated using a solid diamond end mill with an outer diameter of φ3.5mm. It should be noted that a finishing allowance of 0.02mm-0.05mm needs to be reserved on the bottom surface of the central countersunk hole 9. Finally, a sintered diamond tool is used to finish the bottom surface of the central countersunk hole 9. During machining, since the tool feeds along the axial direction of the workpiece blank 1, the workpiece blank 1 is only subjected to vertical stress and will not be affected by horizontal stress, thus improving the machining quality. Because the connecting plate 4 is thin-walled, the rosin and paraffin wax acting as adhesives can support the workpiece blank 1, reducing the axial force on the workpiece blank 1 during axial machining and preventing damage to the connecting plate 4 that could result in scrap.

[0069] Loosen clamp 6 to melt rosin and paraffin, flip workpiece blank 1 over, clean workpiece blank 1 and cylindrical glass 7, and expose the boss 8 of another unmachined center countersunk hole 9 outside the positioning countersunk hole 11. Adjust using a lever dial indicator, and then use melted rosin and paraffin adhesive to solidify cylindrical glass 7 and workpiece blank 1 again. Use a polytetrafluoroethylene gasket to protect the upper surface of the connecting plate 4 of workpiece blank 1. Clamp 6 presses against the polytetrafluoroethylene gasket to fix cylindrical glass 7 and workpiece blank 1.

[0070] According to the operation steps of machining the first central countersunk hole 9, the boss 8 exposed outside the positioning countersunk hole 11 is machined with the central countersunk hole 9. The entire machining process is assisted by ultrasound. After machining is completed, the clamp 6 is released, the rosin and paraffin are melted, the machined workpiece is removed and cleaned. The machining of the integrated quartz sensing element is thus completed. The central through hole 10 can be used as a vent to avoid air pressure difference between the two bosses 8 during assembly. The function of the bosses 8 and the central countersunk hole 9 is to assemble external components.

[0071] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A machining method for an integrated quartz sensing element, characterized in that, The sensitive element includes two symmetrical and coaxially arranged bosses (8), and a connecting plate (4) is integrally formed between the two bosses (8). The sidewalls of the two bosses (8) that are far apart are provided with central countersunk holes (9). A central through hole (10) is provided at the center of the connecting plate (4), and the two ends of the central through hole (10) are respectively connected to the two central countersunk holes (9). The processing method includes: A workpiece blank (1) is machined on a quartz rod, and the workpiece blank (1) and the quartz rod are separated. The workpiece blank (1) includes two symmetrical bosses (8) and a connecting plate (4) located between the two bosses (8). The workpiece blank (1) is clamped and one of the bosses (8) is exposed. The other boss (8) is cured with an adhesive. A central through hole (10) and a central countersunk hole (9) are machined on the exposed boss (8). Among them, the axial length of the integrated sensitive element is the first length, the axial length of the boss (8) is the second length, the thickness of the connecting plate (4) is the third length, the outer diameter of the boss (8) is the fifth length, the inner diameter of the central through hole (10) is set to the sixth length, and the inner diameter of the central countersunk hole (9) is set to the fourth length. The processing method is applied to a machine tool, which has a rotatable worktable (3) and a fixture (6) for clamping the workpiece. The machine tool also has a cutting tool for processing. The process of machining a workpiece blank on a quartz bar includes the following steps: Quartz rods are selected as blanks (12). The blanks (12) are clamped using an internal expansion fixture (2) and mounted on the worktable (3). The axis of the electroplated diamond end mill is perpendicular to the axis of the blank (12). The machine tool is started to rotate the worktable (3) and the electroplated diamond end mill. The radial feed of the electroplated diamond end mill is controlled, with the feed depth being the difference between the outer diameter of the reference surface and the fifth length. The end mill moves axially along the outer diameter of the reference surface to machine the first boss (8) with an axial length of the second length. After machining the first boss (8), the electroplated diamond end mill is removed, and the boss (8) is cured with an adhesive. The workpiece blank (1) is processed by moving the electroplated diamond end mill along the outer circle of the reference surface (12) and leaving a third length as a connecting plate (4). The part of the outer circle of the reference surface away from the worktable (3) is processed by the electroplated diamond end mill with the same radial feed depth and moving along the outer circle of the reference surface to process the second boss (8) with an axial length of the second length. The workpiece blank (1) is thus completed. After the first boss (8) is processed, the boss (8) and the workpiece blank (12) are cured with adhesive, including wrapping the boss (8) with sulfuric acid paper and pouring in molten rosin and paraffin for bonding. The machining of the central through hole (10) and the central countersunk hole (9) on the exposed boss (8) specifically includes the following steps: First, a hollow diamond drill bit with an outer diameter of the sixth length is used to axially feed at the center of the exposed boss (8) to machine the central through hole (10), with a drilling depth greater than the sum of the second and third lengths and less than the first length; then, a hollow diamond drill bit with an outer diameter of the fourth length is used to coaxially feed on the boss (8) to machine the central countersunk hole (9), with a drilling depth of the second length; then, the size of the hollow diamond drill bit is gradually reduced and fed axially along the boss (8) in sequence, leaving a machining allowance, and then the machined central countersunk hole (9) is precision machined; then, the workpiece blank (1) is flipped over and clamped, and the central countersunk hole (9) is machined on another boss (8), with ultrasonic assistance used throughout the machining process; Since the drilling depth of the central through hole (10) is greater than the sum of the second length and the third length and less than the first length, after the central countersunk holes (9) on the two bosses (8) are completed, the two ends of the central through hole (10) are connected to the two central countersunk holes (9).

2. The machining method for an integrated quartz sensing element according to claim 1, characterized in that, Cut the connection between the first boss (8) and the blank bar (12), remove the workpiece blank (1), melt the cured adhesive, clean the workpiece blank (1), and then remove the inner expansion fixture (2) and the remaining blank bar (12) from the machine tool worktable (3).

3. The machining method for an integrated quartz sensing element according to claim 2, characterized in that, Select a cylindrical glass (7) with parallel sides. Machine a positioning countersunk hole (11) that matches the size of the boss (8) at the center of one end face of the cylindrical glass (7). Then place the cylindrical glass (7) on the surface of the worktable (3) so that the end face where the positioning countersunk hole (11) is located is far away from the worktable (3). Place one boss (8) of the workpiece blank (1) in the positioning countersunk hole (11) to ensure that the workpiece blank (1) and the cylindrical glass (7) are coaxial. Use an adhesive to bond and solidify the workpiece blank (1) and the cylindrical glass (7). Set a washer (5) on the upper end face of the connecting plate (4). Use a clamp (6) to press the washer (5) so that the workpiece blank (1) and the cylindrical glass (7) that are solidified together press against the worktable (3) and ensure that the cylindrical glass (7) and the worktable (3) are coaxial.

4. The machining method for an integrated quartz sensing element according to claim 3, characterized in that, At the center of the boss (8) exposed outside the cylindrical glass (7), a hollow diamond drill bit with an outer diameter of the sixth length is used to feed and drill along the axial direction of the workpiece blank (1). It is not necessary to drill through the workpiece blank (1). The drilling depth is greater than the sum of the second and third lengths and less than the first length. At this time, the inner diameter of the central through hole (10) is the sixth length. Then, a hollow diamond drill bit with an outer diameter of the fourth length is used to coaxially process the central countersunk hole (9) on the boss (8). The drilling depth is the second length. Then, the outer diameter of the hollow diamond drill bit is gradually reduced, and drilling is performed in sequence. The drilling depth is the second length, and a machining allowance is reserved. Finally, the central countersunk hole (9) is finished. Thus, the machining of the central countersunk hole (9) of the first boss (8) is completed. Ultrasonic auxiliary machining is used throughout the machining process.

5. The machining method for an integrated quartz sensing element according to claim 4, characterized in that, Release the clamp (6) from the connecting plate (4) and the cylindrical glass (7), melt the adhesive, remove the finished integrated quartz sensitive element and clean it, thus completing the processing of the integrated quartz sensitive element.

6. The machining method for an integrated quartz sensing element according to claim 5, characterized in that, The processing method includes the following steps: S1. Using quartz rod as blank, grind and polish the outer circle of the blank as the reference surface for mounting and processing, so that the reference surface meets the required size and accuracy requirements. S2. Use the internal expansion fixture (2) to clamp the blank bar (12), expose the reference surface completely outside the internal expansion fixture (2), and install the fixture on the surface of the machine tool table (3) through the clamp (6) so that the outer circle of the reference surface is coaxial with the machine tool table (3); S3. Start the machine tool to rotate the worktable (3), use an electroplated diamond milling cutter to feed radially to process two symmetrical bosses (8), and reserve a third length between the two bosses (8) as a connecting plate (4). Ultrasonic assisted processing is used throughout the process. S4. Cut the finished workpiece blank (1) and the bar stock to separate the workpiece blank (1) and the blank bar stock (12), and remove the inner expansion fixture (2). S5. Select cylindrical glass (7) and machine a positioning countersunk hole (11) at the center of one end face of cylindrical glass (7) to accommodate the boss (8). Place cylindrical glass (7) on the surface of worktable (3) and place one boss (8) of workpiece blank (1) in the positioning countersunk hole (11). Use adhesive to bond and solidify workpiece blank (1) and cylindrical glass (7), and then install cylindrical glass (7) on the surface of worktable (3) using clamp (6). S6. Using a hollow diamond drill bit with an outer diameter of the sixth length, drill a central through hole (10) along the axial direction of the workpiece blank (1) at the center of the boss (8) exposed outside the cylindrical glass (7). Then, use a hollow diamond drill bit with an outer diameter of the fourth length to coaxially machine a central countersunk hole (9) on the boss (8). Then, gradually reduce the outer diameter of the hollow diamond drill bit and drill holes in sequence. Finally, perform finishing on the central countersunk hole (9). Ultrasonic auxiliary machining is used throughout the machining process. S7. Release the clamp (6) from the workpiece blank (1) and cylindrical glass (7), melt the adhesive and clean the workpiece blank (1) and cylindrical glass (7), place the boss (8) with the center countersunk hole (9) after machining into the positioning countersunk hole (11) of the cylindrical glass (7), and use the adhesive again to bond and solidify the workpiece blank (1) and cylindrical glass (7). By setting the washer (5) on the connecting plate (4), and then the clamp (6) presses against the washer (5) again, so that the workpiece blank (1) and cylindrical glass (7) solidified together press against the worktable (3) and ensure that the cylindrical glass (7) and the worktable (3) are coaxial. Then repeat step S6.

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