Small-ball-diameter inner spherical surface grinding machining device and using method

Abstract

The invention belongs to the technical field of machining, and discloses a small-ball-diameter inner spherical surface grinding device and a using method.The small-ball-diameter inner spherical surface grinding device comprises a clamp body and grinding steel balls, a plurality of clamp holes are formed in the bottom of the clamp body, and the clamp holes are circularly arranged around the center of the bottom of the clamp body; the clamp hole is matched with the top of a to-be-machined part, the to-be-machined part is clamped in the clamp hole, and the bottom of the to-be-machined part is provided with a to-be-machined hemispherical surface; and the grinding steel balls are matched with a to-be-machined hemispherical surface. By means of non-fixed-axis rotation of the grinding steel ball, the problem that the service life of a part is seriously shortened or the performance is unstable due to protrusions near the small-ball-diameter inner spherical surface finish machining axis is solved, and the disturbance or clamping stagnation phenomenon caused by protrusion of the bottom spherical center of the spherical surface and out-of-tolerance profile tolerance in the operation process of a spherical pair is avoided; and the machining quality of parts is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing, and in particular relates to a small-diameter inner spherical surface grinding processing device and a use method thereof. Background Art

[0002] When machining a workpiece with an inner spherical surface, the spherical milling cutter or grinder will rotate along a fixed axis during the forming process. The larger the diameter of the sphere, the greater the linear velocity of the point along the circumference of the sphere. The linear velocity of the central axis of the sphere is always 0, resulting in the feed amount at the bottom of the center of the sphere always being smaller than that at the periphery, eventually forming a micro-protrusion, such as Figure 5 As shown, this can lead to unstable product quality, seriously affecting product quality and delivery. Conventional methods such as turning, grinding, milling or lathe head processing to produce spherical surfaces are all fixed-axis processing, which cannot avoid the problem of bulging at the bottom of the sphere center, thus affecting the spherical profile.

[0003] The Chinese patent application, CN104526472A, is titled "Apparatus and Method for High-Frequency Vibration Polishing of Metal Micro-Concave Spherical Surfaces." The apparatus comprises a bracket, with a first support frame and a second support frame extending parallel to one side. The first support frame is mounted with a lift adjustment device. The output end of the lift adjustment device passes through the first support frame and is connected to a high-frequency vibration generator. The bottom of the high-frequency vibration generator holds a profiling tool head. A motor is secured to the lower portion of the second support frame. The motor's output shaft passes through the second support frame and is connected to a fixture. The fixture's rotation center and the profiling tool head are coaxially located. A metal micro-concave spherical part is clamped to the fixture, and the concave spherical surface of the metal micro-concave spherical part is coated with a polishing agent. The lift adjustment device, high-frequency vibration generator, and motor are all connected to a control device via a wiring harness. The fixture's rotation center and the profiling tool head are coaxially located. Due to fixed-axis rotation, the linear velocity at the axis is zero and does not participate in the machining process, which can affect the machining effect when machining micro-spherical surfaces. Summary of the Invention

[0004] In order to overcome the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a small-diameter spherical surface grinding processing device and a method of use. The spherical surface of the part to be processed is processed by a small ball rotating without a fixed axis, so that the spherical surface processing is uniform and free of micro-protrusions, and the spherical surface profile and roughness are qualified, thereby improving the spherical surface processing efficiency and quality stability.

[0005] To achieve the above object, the technical solution adopted by the present invention is: A small-diameter inner spherical surface grinding and processing device includes: a fixture body and grinding steel balls, a plurality of fixture holes are opened at the bottom of the fixture body, the fixture holes are arranged around the center circle of the bottom of the fixture body, the fixture holes match the top of the part to be processed, the part to be processed is clamped in the fixture holes, and the bottom of the part to be processed has a hemispherical surface to be processed; the grinding steel balls match the hemispherical surface to be processed.

[0006] Optionally, a counterweight is provided on the top of the clamp body.

[0007] Optionally, the outer shell of the clamp body is provided with a fixing ring.

[0008] Optionally, the fixing ring is fixed on a clamping portion of a surface grinding machine.

[0009] Optionally, the clamp hole is a through hole, and both ends of the clamp hole are respectively connected to the top of the bottom of the clamp body.

[0010] Optionally, the top of the clamp body has a first clamp step and a second clamp step, and clamp holes are provided in the first clamp step and the second clamp step.

[0011] Optionally, the fixture hole includes a bottom hole and an exhaust hole, the bottom hole matches the top of the part to be processed, and the diameter of the exhaust hole is smaller than the diameter of the top of the part to be processed.

[0012] Optionally, the radius of the hemispherical surface to be processed is 1.5 mm to 10 mm.

[0013] The method for using the small-diameter inner spherical surface grinding device comprises the following steps: S1: Install the fixture body on the surface grinder, place the workpiece to be processed in the fixture hole of the fixture body, and place grinding steel balls at the bottom of the workpiece to be processed; S2: Start the surface grinder to cut the hemispherical surface of the part to be processed.

[0014] Optionally, in step S1, abrasive paste is evenly coated on the grinding steel balls.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a small-diameter inner spherical surface grinding and processing device and a method for use. The present invention installs a part into a special fixture and fixes it, installs a steel ball coated with a uniform amount of grinding paste on the spherical surface to be processed, and turns it upside down on a surface grinder. A fixing ring is used to fix the fixture body to prevent movement, and a counterweight is applied to the fixture as a whole to increase the friction between the steel ball and the spherical surface, and between the steel ball and the grinding platform. The surface grinder is started, and the friction force drives the steel ball to rotate to achieve the grinding and cutting action on the spherical surface. The present invention can ensure the surface profile of the processed spherical surface through the profile of the standard steel ball, and improve the roughness of the spherical surface through grinding.

[0016] The present invention's method for using a grinding apparatus for small-diameter inner spherical surfaces effectively addresses the issue of severely shortened component life or unstable performance caused by protrusions near the axis of fine machining of small-diameter inner spherical surfaces. This fundamentally improves the spherical profile and roughness quality of the small spherical surface, avoids disturbances or jamming caused by protrusions at the bottom center of the spherical surface and profile deviations during operation, and improves component machining quality. Furthermore, the grinding fixture of the present invention can process multiple parts at a time, improving component machining efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only schematic and are used to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the components of the present invention. In the drawings: Figure 1 Schematic cross-sectional view of the small-diameter inner spherical surface grinding device of the present invention; Figure 2 This is a schematic diagram of the part to be processed according to the present invention; Figure 3 A three-dimensional diagram of the clamp body of the present invention; Figure 4 This is a bottom view of the clamp body of the present invention; Figure 5 These are microscopic protrusions caused by existing processing methods; Among them, 1. Clamp body; 11. Outer ring clamp hole; 12. Inner ring clamp hole; 1101. Outer ring clamp bottom hole; 1102. Outer ring clamp exhaust hole; 1103. Outer ring clamp middle hole; 1201. Outer ring clamp bottom hole; 1202. Outer ring clamp exhaust hole; 1203. Outer ring clamp middle hole; 13. Clamp first step; 14. Clamp second step; 2. Grinding steel balls; 3. Parts to be processed; 31. Connecting part; 32. Base; 33. Surface to be processed; 4. Counterweight; 5. Fixed ring. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0020] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0021] When an element is referred to as being "disposed on" another element, it may be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may also be an intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiments. If the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and it does not mean that the structure must be completely horizontal, but it can be slightly tilted.

[0022] It should be noted that similar reference numerals and letters denote similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures. In the description of the present invention, it should be understood that the terms "comprise" and "include" indicate the presence of the described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their combinations.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0024] The present invention will be described in detail below with reference to the accompanying drawings.

[0025] like Figure 1 As shown, a small-diameter inner spherical grinding processing device of the present invention includes: a fixture body 1 and a grinding steel ball 2, a plurality of fixture holes are opened at the bottom of the fixture body 1, and the fixture holes are arranged around the center circle of the bottom of the fixture body 1, and the fixture holes match the top of the part to be processed 3, and the part to be processed 3 is clamped in the fixture holes. The bottom of the part to be processed 3 has a hemispherical surface 33 to be processed; the grinding steel ball 2 matches the hemispherical surface 33 to be processed.

[0026] A counterweight 4 is provided on the top of the clamp body 1 , and a fixing ring 5 is provided on the outer shell of the clamp body 1 . The fixing ring 5 is used to connect to a surface grinder.

[0027] By installing the top of the part to be processed 3 in the fixture hole and placing the grinding steel ball 2 at the bottom of the part to be processed 3, and then installing the fixture body 1 in the fixing ring 5, fixing the fixing ring 5 to the surface grinder, and placing the installed fixture body 1 on the surface grinder, the surface of the surface grinder is rotated to drive the grinding steel ball 2 to rotate, and the top of the grinding steel ball 2 contacts the hemispherical surface 33 to be processed at the bottom of the part to be processed 3. The top of the part to be processed 3 is fixed by the fixture body 1 and the downward pressure of the counterweight block 4, so that the position of the part to be processed 3 remains unchanged, and the position of the fixture body 1 on the surface grinder remains unchanged through the fixing ring 5, so that the grinding steel ball 2 can fully grind the hemispherical surface 33 to be processed.

[0028] The method for using the small-diameter inner spherical surface grinding device comprises the following steps: S1: Install the fixture body 1 on the surface grinding machine, place the workpiece 3 to be processed in the fixture hole of the fixture body 1, and place the grinding steel ball 2 at the bottom of the workpiece 3 to be processed; S2: Start the surface grinding machine to cut the hemispherical surface 33 of the part 3 to be processed.

[0029] The small-diameter inner spherical surface grinding processing device of the present invention fixes the part to be processed 3 through the clamp hole, and places the grinding steel ball 2 in the hemispherical surface 33 to be processed. The grinding steel ball 2 is rotated by the plane grinder, which can realize the non-fixed axis rotation of the grinding steel ball 2, effectively solving the problem of seriously shortened part life or unstable performance caused by the protrusion near the axis of the fine processing of the small-diameter inner spherical surface, and fundamentally improves the spherical profile and roughness quality of the small spherical surface, avoids the disturbance or jamming caused by the protrusion of the center position of the bottom of the spherical surface and the excessive profile during the operation of the spherical pair, and improves the processing quality of the part.

[0030] Example 1 like Figure 1 As shown, a small-diameter inner spherical surface grinding processing device includes: a fixture body 1 and a grinding steel ball 2. The bottom of the fixture body 1 is opened with a plurality of fixture holes, and the fixture holes are arranged around the center circle of the bottom of the fixture body 1.

[0031] like Figure 2 As shown, the workpiece 3 to be processed includes a base 32, on which a connecting portion 31 is provided, which matches the fixture hole. A hemispherical surface 33 to be processed is formed on the end surface of the base 32, and the grinding steel ball 2 matches the hemispherical surface 33 to be processed.

[0032] Specifically, the grinding steel balls 2 are standard steel balls.

[0033] Specifically, the radius of the hemispherical surface 33 to be processed is 1.5 mm to 10 mm.

[0034] The fixture hole is a through hole, and its two ends are respectively connected to the bottom and top of the fixture body 1. The fixture hole includes a bottom hole and a vent hole. The bottom hole matches the top of the part 3 to be processed. The diameter of the vent hole is smaller than the diameter of the top of the part 3 to be processed. The part 3 to be processed is clamped in the fixture hole.

[0035] Furthermore, an intermediate hole is provided between the bottom hole and the vent hole, the diameter of which matches the top of the part 3 to be machined. The intermediate hole is concentric with the bottom hole, and the vent hole is only required to be a through hole. No size requirements apply to the vent hole, as long as it extends through the top of the fixture body 1. In other words, only the bottom hole and the intermediate hole, which serve to secure the part 3 to be machined, need to meet the requirements. The remaining vent holes do not need to meet the required precision and only need to connect the top of the fixture body 1 with the intermediate hole. The design of the intermediate hole can reduce the aspect ratio of the part that requires fine machining, thereby reducing the difficulty of machining the fixture hole.

[0036] The clamp body 1 is a cylinder, and the top of the clamp body 1 has a clamp first step 13 and a clamp second step 14. The clamp first step 13 is annular, the clamp second step 14 is circular, and clamp holes are provided in the clamp first step 13 and the clamp second step 14.

[0037] A counterweight 4 is provided on the top of the clamp body 1 , and the shape of the counterweight 4 matches the first step 13 and the second step 14 of the clamp.

[0038] Furthermore, the inner wall of the counterweight block 4 is connected to the side wall of the first step 13 of the clamp, the top of the first step 13 of the clamp, the side wall of the second step 14 of the clamp, and the top of the second step 14 of the clamp; the outer wall of the counterweight block 4 is provided with a fixing ring 5, and the fixing ring 5 is fixed on the clamping part of the surface grinder.

[0039] The first step 13 of the clamp is surrounded by a plurality of outer clamp holes 11, and the second step 14 of the clamp is surrounded by a plurality of inner clamp holes 12. The inner and outer clamp holes 12, 11 are arranged in a circle with the clamp body 1 as the center.

[0040] Preferably, the inner ring fixture holes 12 are arranged at equal intervals, and the outer ring fixture holes 11 are arranged at equal intervals.

[0041] Specifically, the number of the inner ring clamp holes 12 is eight, and the number of the outer ring clamp holes 11 is sixteen.

[0042] Specifically, the connection portion 31 and base 32 of the part 3 to be machined are both cylindrical, and the diameter of the connection portion 31 of the part 3 to be machined is smaller than the diameter of the base 32. The outer ring fixture hole 11 includes an outer ring fixture bottom hole 1101, an outer ring fixture middle hole 1103, and an outer ring fixture vent hole 1102. The diameter of the outer ring fixture bottom hole 1101 is the same as the diameter of the base 32 of the part 3 to be machined. The diameter of the outer ring fixture middle hole 1103 is the same as the diameter of the connection portion 31 of the part 3 to be machined.

[0043] The inner race fixture hole 12 includes an outer race fixture bottom hole 1201, an outer race fixture middle hole 1203, and an outer race fixture bottom hole 1201. The diameter of the outer race fixture bottom hole 1201 is the same as the diameter of the base 32 of the workpiece 3 to be machined. The diameter of the outer race fixture middle hole 1203 is the same as the diameter of the connecting portion 31 of the workpiece 3 to be machined.

[0044] Example 2 In this embodiment, a spherical pair serves as the output terminal of a centrifugal speed sensor. Both the inner and outer spherical surfaces must achieve a surface profile within 0.005 and a surface roughness within Ra0.2 to ensure stable transmission without binding. The support seat is a precision transmission component, and the working surface is the inner spherical surface of the spherical pair.

[0045] When the existing fixed-axis rotation method is used for processing, the spherical milling cutter or grinder performs fixed-axis rotational motion during processing, resulting in the feed amount at the bottom center of the sphere always being smaller than the periphery, eventually forming a micro-protrusion. During the use of the product, the main contact point between the ball and socket parts and the ejector pin is the center of the sphere at the bottom of the sphere, so the spherical contour and roughness deviations directly affect the sensor performance, and the ball diameter is too small to be processed by the unfolding method. The unstable product quality seriously affects product quality and product delivery.

[0046] It is based on a small-diameter inner spherical grinding processing device described in Example 1; in this embodiment, the mass of the counterweight block 4 is 5kg to 10kg; in this embodiment, the grinder is an FLM500R type surface grinder; in this embodiment, the part 3 to be processed is a centrifugal speed sensor support seat; in this embodiment, the number of fixing rings 5 ​​is three, and each fixing ring 5 is installed with a fixture body 1 and a counterweight block 4, and each fixing ring 5 is connected to the clamping part of the FLM500R type surface grinder.

[0047] The small-diameter inner spherical surface grinding and processing device, when used, comprises the following steps: The fixture body 1 and the counterweight 4 are mounted in the fixing ring 5, and the fixing ring 5 is placed on the plane of the surface grinder. The three fixing rings 5 ​​are arranged equidistantly in the annular direction.

[0048] The part to be processed 3 is placed in the fixture hole of the fixture body 1, and the grinding steel ball 2 is placed at the bottom of the part to be processed 3; wherein, the grinding steel ball 2 is evenly coated with grinding paste.

[0049] The surface grinding machine is started to cut the hemispherical surface 33 of the part 3 to be processed.

[0050] The surface profile of the processed sphere is ensured by the profile of the standard steel ball, and the processed sphere is run-in using a steel ball made of a better wear-resistant material, thereby transferring the spherical profile accuracy of the steel ball to the processed sphere, and improving the roughness of the hemispherical surface 33 to be processed by grinding.

[0051] Adjust the speed and frequency of the surface grinder, start the turntable, and the rotation of the turntable drives the bottom grinding steel ball 2 to move relative to each other to achieve cutting. Run for 10 minutes.

[0052] Clean the abrasive paste immediately after processing.

[0053] Check and record the changes in size, roughness and appearance of parts after processing.

[0054] In this embodiment, spherical surfaces with SR (spheric radius) of 1.5 mm, 2 mm, and 3 mm are taken as examples, and the statistical results are shown in Table 1 below.

[0055] Table 1

[0056] In Table 1, the surface profile can reflect the shape accuracy of the spherical surface, and the smaller the value, the higher the accuracy; the surface roughness can reflect the smoothness of the spherical surface, and the smaller the value, the smoother and flatter the surface.

[0057] After all processes are completed and the measurements are qualified, the parts must be ultrasonically cleaned and packaged in time to prevent foreign objects from damaging the finished surface. The finishing process of spherical grinding is completed.

[0058] According to the above data, it can be seen that the small-diameter inner spherical surface grinding processing device of the present invention can eventually reduce the surface profile of the hemispherical surface 33 to be processed in this embodiment from 0.008mm to 0.01mm to 0.003mm to 0.005mm.

[0059] Unless otherwise specified, the device components involved in the above embodiments are all conventional device components, and the structural settings, working modes or control modes involved are all conventional settings, working modes or control modes in the art unless otherwise specified.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and are not limiting. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in this field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A small-diameter inner spherical surface grinding device, characterized in that: include: A clamp body (1) and a grinding steel ball (2), wherein a plurality of clamp holes are provided at the bottom of the clamp body (1), the clamp holes are arranged in a circular shape around the center of the bottom of the clamp body (1), the clamp holes match the top of a part to be processed (3), the part to be processed (3) is clamped in the clamp holes, and the bottom of the part to be processed (3) has a hemispherical surface (33) to be processed; and the grinding steel ball (2) matches the hemispherical surface (33) to be processed.

2. A small-diameter inner spherical surface grinding device according to claim 1, characterized in that: A counterweight block (4) is arranged on the top of the clamp body (1).

3. The small-diameter inner spherical surface grinding device according to claim 1 is characterized in that: The outer shell of the clamp body (1) is provided with a fixing ring (5).

4. A small-diameter inner spherical surface grinding device according to claim 3, characterized in that: The fixing ring (5) is fixed on a clamping portion of a surface grinding machine.

5. The small-diameter inner spherical surface grinding device according to claim 1, characterized in that: The clamp hole is a through hole, and both ends of the clamp hole are respectively connected to the top of the bottom of the clamp body (1).

6. A small-diameter inner spherical surface grinding device according to claim 5, characterized in that: The top of the clamp body (1) is provided with a first clamp step (13) and a second clamp step (14), and clamp holes are provided in the first clamp step (13) and the second clamp step (14).

7. The small-diameter inner spherical surface grinding device according to claim 5, characterized in that: The fixture hole comprises a bottom hole and an exhaust hole, the bottom hole matches the top of the part to be processed (3), and the diameter of the exhaust hole is smaller than the diameter of the top of the part to be processed (3).

8. The small-diameter inner spherical surface grinding device according to claim 1, characterized in that: The radius of the hemispherical surface (33) to be processed is 1.5 mm to 10 mm.

9. A method for using a small-diameter inner spherical surface grinding device according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Install the fixture body (1) on the surface grinding machine, place the part to be processed (3) in the fixture hole of the fixture body (1), and place a grinding steel ball (2) at the bottom of the part to be processed (3); S2: Start the surface grinding machine to cut the hemispherical surface (33) to be processed of the part (3).

10. The method for using the small-diameter inner spherical surface grinding processing device according to claim 9, characterized in that: In step S1, abrasive paste is evenly applied on the grinding steel ball (2).

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