Precision Machining Device For Sphere And Machining Method

Abstract

The present disclosure discloses a sphere precision machining device and a machining method comprising a cavity, an abrasive grain stream and a circulation device. The the cavity holds the workpiece. The cavity comprises two hollow hemispheres, each of the two hemispheres being provided with a main flow channel. The main flow channel is connected to the cavity. One end of the main flow path of each of the two hemispheres is connected to a circulating means by which a stream of abrasive grains is made to grind the workpiece. A plurality of main flow channels are disposed homogeneously inside the hemisphere, each ofthe main flow channels being provided with a plurality of branch flow channels connected to the cavity, the branch flow channels tapering in the flow direction. The present disclosure uses the difference in abrasive grain flow pressure on the surface of the workpiece to achieve precision machining, which can effectively improve the shape accuracy of the workpiece.

Description

A sphere precision machining device and machining method Technical Field

[0001] The present invention relates to the field of special processing, and in particular to a sphere precision processing device and a processing method. Background Art

[0002] High-precision spheres have high requirements for shape accuracy, surface quality and consistency. They have a very critical impact on the production of high-end basic components such as high-precision linear guides, high-precision ball screws, high-performance bearings and high-precision optical devices. They will affect the overall accuracy of precision components and may even cause damage to other components, ultimately affecting the service life of the entire equipment.

[0003] Summary of the Invention

[0004] In response to the shortcomings of the prior art, the present invention provides a sphere precision processing device and processing method. The workpiece is placed in a sealed circular cavity and an abrasive flow is introduced into the circular cavity. A main channel is provided in the circular cavity for the circulation of the abrasive flow. A branch channel is provided on the main channel. The abrasive flow contacts the workpiece through the branch channel and precision grinding is performed on the raised parts of the workpiece surface.

[0005] The present invention achieves the above technical objectives through the following technical means.

[0006] A spherical precision processing device includes a cavity, an abrasive flow and a circulation device. A workpiece is placed in the cavity. The cavity is composed of two hollow hemispheres. Main channels are respectively provided in the two hemispheres, and the main channels are connected to the cavity. One end of the main channels of the two hemispheres is respectively connected to the circulation device, and the abrasive flow grinds the workpiece through the circulation device.

[0007] Furthermore, a plurality of main flow channels are uniformly distributed inside the hemisphere, and each of the main flow channels is provided with a plurality of branch flow channels communicating with the cavity, and the branch flow channels gradually shrink along the flow direction.

[0008] Furthermore, the axis of the branch flow channel forms an angle of 20° to 45° with the radial direction thereof.

[0009] Furthermore, a sealing assembly is provided between the butt joint surfaces of the two hemispheres for sealing.

[0010] Furthermore, it also includes a control system, a vibration sensor and a pressure sensor;

[0011] Several vibration sensors are installed on the inner wall of the cavity to detect vibration signals generated by the abrasive flow;

[0012] The pressure sensor is used to detect the abrasive flow pressure output by the circulation device;

[0013] The control system adjusts the output pressure of the circulation device according to the vibration signal.

[0014] A processing method of the sphere precision processing device comprises the following steps:

[0015] Place the workpiece into the cavity and install the hemisphere in a sealed manner;

[0016] The abrasive flow is pumped to the cavity to grind the workpiece through the circulation device;

[0017] Several vibration sensors detect vibration signals generated by the abrasive flow, and the control system adjusts the output pressure of the circulation device according to the vibration signals;

[0018] After the grinding process is completed, the workpiece is taken out to check whether the shape accuracy and surface quality meet the set requirements. If not, it is put back into the cavity for processing.

[0019] Furthermore, the control system adjusts the output pressure of the circulation device according to the vibration signal, specifically:

[0020] The initial state sets the output pressure of the circulation device to P0.

[0021] After processing time t1, the control system calculates the average value S of several vibration signals. t1 Compared with the first set value, when the average value S t1 When it is less than the first set value, the grinding process is completed;

[0022] When the average value S t1 When the pressure is greater than the first set value, the control system increases the output pressure of the circulation device to P1; after adjusting the pressure and processing time t2, when the average value S t2 is greater than the first set value, and the average value S t2 Less than the average S t1 When the output pressure of the circulation device is reduced to P2, the control system reduces the output pressure of the circulation device to P2, and P1>P2>P0; until the average value S t1 is less than the first set value.

[0023] The beneficial effects of the present invention are:

[0024] 1. The sphere precision machining device and method described in this invention achieve high-precision sphere machining by sealing two hemispheres. The axes of the abrasive inlet and return holes are designed to form an angle of 20° to 45° with their respective radial directions, causing the abrasive flow to drive the workpiece in a counterclockwise rotation. This precision machining is achieved by utilizing the difference in abrasive flow pressure across the workpiece surface, effectively improving the workpiece's shape accuracy.

[0025] 2. The spherical precision machining device and method described in the present invention uses changes in vibration signals to detect the workpiece's machining status. At the beginning of machining, due to the uneven surface of the workpiece, the raised portions of the workpiece are subjected to high pressure, increasing the abrasive flow's cutting effect on the raised portions, resulting in increased vibration within the machining device. Once all the raised portions are removed, the workpiece gradually transforms into a precise spherical shape, and the vibration within the machining device gradually decreases. The control system determines whether the workpiece's machining is complete based on the vibration signal. This detection method effectively reduces the number of actual workpiece measurements during machining, improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. The drawings described below are some embodiments of the present invention. For ordinary technicians in this field, it is obvious that other drawings can be obtained based on these drawings without paying any creative work.

[0027] FIG1 is a cross-sectional view of the sphere precision machining device according to the present invention.

[0028] FIG2 is an exploded view of the sphere precision processing device according to the present invention.

[0029] FIG3 is a flow chart of the processing method of the sphere precision processing device according to the present invention.

[0030] In the figure: 1-bolt connection; 2-locating pin; 3-serrated sealing structure; 4-abrasive flow inlet; 5-vibration sensor; 6-workpiece; 7-first hemisphere; 8-abrasive flow inlet hole; 9-second hemisphere; 10-abrasive flow; 11-abrasive flow return hole; 12-control system; 13-signal line; 14-pipe joint thread; 15-connecting pipe; 16-sealing gasket; 17-abrasive flow outlet; 18-pressure pump; 19-abrasive flow delivery pipe; 20-abrasive flow recovery device; 21-pressure valve; 22-protruding part of the workpiece; 23-flat part of the workpiece. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0032] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "axial", "radial", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0034] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0035] As shown in Figures 1 and 2, the spherical precision machining device of the present invention includes a circular cavity, an abrasive flow 10, and a circulation device. The circular cavity is used to place a workpiece 6 to be processed. The circular cavity is composed of two hollow hemispheres, namely a first hemisphere 7 and a second hemisphere 9. The first hemisphere 7 and the second hemisphere 9 are connected by a sealing device. The sealing device includes a locating pin 2, a bolt connector 1, and a serrated sealing structure 3 located at the junction of the first hemisphere 7 and the second hemisphere 9. The locating pin 2 is used to position the connection between the first hemisphere 7 and the second hemisphere 9. The locating pin 2 is a conical pin that can ensure the positioning accuracy of the first hemisphere 7 and the second hemisphere 9, ensuring that the first hemisphere 7 and the second hemisphere 9 form a precise spherical space. The serrated sealing structure 3 can ensure that the first hemisphere 7 and the second hemisphere 9 are leak-proof after connection. Finally, the bolt connector 1 ensures that the first hemisphere 7 and the second hemisphere 9 have a sufficiently high connection strength after connection.

[0036] The first hemisphere 7 is provided with an abrasive flow inlet 8, the second hemisphere 9 is provided with an abrasive flow outlet 17, the first hemisphere 7 is provided with a first main channel, the first main channel is connected to the abrasive flow inlet 8 and the cavity respectively, the second hemisphere 9 is provided with a second main channel, the second main channel is connected to the abrasive flow outlet 17 and the cavity respectively, and the abrasive flow 10 forms a circulation loop between the abrasive flow inlet 4, the circular cavity and the abrasive flow outlet 17 through a circulation device. The first main channel and the second main channel are not connected to each other, and each of the first main channels is provided with a plurality of abrasive flow inlet holes 8 connected to the cavity, and the abrasive flow inlet holes 8 gradually shrink along the flow direction. Each of the second main channels is provided with a plurality of abrasive flow return holes 11 connected to the cavity, and the abrasive flow return holes 11 gradually shrink along the flow direction. In the embodiment, the abrasive flow inlet holes 8 and the abrasive flow return holes 11 are respectively tapered holes. The abrasive flow inlet hole 4 and the abrasive flow return hole 11 can guide the flow direction of the abrasive flow 10. The axis of each abrasive flow inlet hole 4 and the abrasive flow return hole 11 forms an angle of 20° to 45° with the radial direction in which they are located. This arrangement enables the abrasive flow 10 to drive the workpiece 6 to rotate counterclockwise, thereby precisely machining the workpiece protrusion 22 on the surface of the workpiece 6 through the abrasive flow 10, thereby removing the workpiece protrusion 22 of the workpiece 6. Preferably, the axis of the abrasive flow inlet hole 4 and the abrasive flow return hole 11 each forms an angle of 35° with the radial direction in which they are located.

[0037] The circulation device includes an abrasive flow conveying pipe 19, a pressure pump 18, an abrasive flow recovery device 20 and a pressure valve 21. The abrasive flow outlet 17 of the second hemisphere 9 is connected to the abrasive flow recovery device 20 through the abrasive flow conveying pipe 19, and the abrasive flow recovery device 20 is connected to the inlet of the pressure pump 18. The abrasive flow recovery device 20 is used to recover and filter the abrasive flow 10; the outlet of the pressure pump 18 is connected to the abrasive flow inlet 4 of the first hemisphere 7, and the abrasive flow outlet 17 is installed with a pressure valve 21 for determining the pressure of the abrasive flow 10; the abrasive flow 10 flowing out of the abrasive flow outlet 17 enters the abrasive flow recovery device 20 through the pressure valve 18, and the abrasive flow recovery device 20 recovers and filters the abrasive flow 10 and then continues to be transported to the abrasive flow inlet 8 by the pressure pump 18. Under the action of the pressure pump 18, the abrasive flow 10 circulates in the circular cavity, and continuously performs precision processing on the surface of the workpiece 6. The abrasive flow inlet 4 and the abrasive flow outlet 17 are both provided with a pipeline sealing device, which includes a pipe joint thread 14, a connecting pipe 15 and a sealing gasket 16. Taking the abrasive flow outlet 17 as an example, the pipe joint thread 14 is provided on the abrasive flow outlet 17, and the connecting pipe 15 is provided on the abrasive flow outlet 17 through a threaded sleeve. A sealing gasket 16 is passed between the connecting pipe 15 and the abrasive flow outlet 17 to improve the sealing performance.

[0038] The circulation system is also connected to a control system 12. Before precision machining begins, the control system 12 determines the flow pressure of the abrasive flow 10 based on the machining allowance of the workpiece 6 to be machined. During precision machining, the control system 12 is also connected to a vibration sensor 5 located on the inner walls of the first hemisphere 7 and the second hemisphere 9. The vibration sensor 5 is connected to the control system 12 via a signal line 13. Based on the difference in vibration signals generated by the abrasive flow 10 at the raised areas 22 and the flat areas 23 of the workpiece, the smoothness of the signal transmitted by the vibration sensor 5 is used to determine the completion of precision machining of the workpiece 6. The control system 12 then adjusts the flow pressure of the abrasive flow 10 based on the vibration signal. The control system 12 adjusts the output pressure of the circulation device based on the vibration signal. If precision machining of the workpiece 6 is complete, the control system 12 automatically and gradually reduces the flow pressure of the abrasive flow 10 to zero via the pressure pump 18. Furthermore, the abrasive particles in the abrasive flow 10 can be determined by material and particle size based on the material and properties of the workpiece 6, enabling machining of a variety of metallic and non-metallic spheres.

[0039] Taking high-precision bearing steel balls as an example, the method of the ball precision machining device of the present invention, as shown in FIG3 , includes the following steps:

[0040] According to the requirements of the high-precision bearing steel balls to be processed, Al2O3 abrasive with a particle size of 4000# is selected, and the abrasive flow pressure is 0.04~0.1MPa; the first set value is determined to be 0.01mm / s based on the material properties.

[0041] The workpiece 6 to be processed and the entire device are cleaned.

[0042] Place the workpiece 6 into the circular cavity. Use the locating pin 2 to position the connection between the first hemisphere 7 and the second hemisphere 9. The serrated seal 3 ensures that there is no leakage after the first hemisphere 7 and the second hemisphere 9 are connected. The bolt connector 1 ensures that the first hemisphere 7 and the second hemisphere 9 have sufficient connection strength after connection. The bolt tightening torque is 3.5 N·m.

[0043] Abrasive flow 10 is introduced into the circular cavity, and the circulation device is turned on to allow the abrasive flow 10 to continuously flow in the circular cavity to perform precision machining on the workpiece 6. Initially, the output pressure P0 of the circulation device is set to 0.04 MPa.

[0044] Several vibration sensors 5 detect the vibration signals generated by the abrasive flow 10, and the control system adjusts the output pressure of the circulation device according to the vibration signals, specifically:

[0045] After 20 minutes of processing, the control system 12 calculates the average value S of the vibration signals. t1 Compared with the first set value, the first set value is 0.01mm / s, when the average value St1 When it is less than 0.01mm / s, the grinding process is completed;

[0046] When the average value S t1 When the pressure is greater than 0.01 mm / s, the control system 12 increases the output pressure of the circulation device to P1 = 0.06 MPa; after adjusting the pressure and processing for 20 minutes, when the average value S t2 Greater than 0.01mm / s, and the average value S t2 Less than the average S t1 When the output pressure of the circulation device is reduced to P2 = 0.05 MPa, and P1>P2>P0; until the average value S t1 As shown in Table 1, the control system 12 determines the output pressure of the adjustment circulation device according to the average value S of the vibration signal.

[0047] After the grinding process is completed, the workpiece 6 is taken out to check whether the shape accuracy and surface quality meet the set requirements. If not, it is put back into the cavity for processing.

[0048] Open the first hemisphere 7 and the second hemisphere 9, take out the workpiece, and measure the workpiece 6. If the accuracy of the workpiece 6 does not meet the requirements, continue to put it into the circular cavity for processing.

[0049] Table 1

[0050] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0051] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A spherical precision machining device, characterized in that: The invention comprises a cavity, an abrasive flow (10) and a circulation device. A workpiece (6) is placed in the cavity. The cavity is composed of two hollow hemispheres (7, 9). The two hemispheres (7, 9) are respectively provided with main channels, and the main channels are connected to the cavity. One end of the main channels of the two hemispheres (7, 9) is respectively connected to the circulation device, and the abrasive flow (10) grinds the workpiece (6) through the circulation device. A plurality of main channels are evenly distributed inside the hemispheres (7, 9), and each of the main channels is provided with a plurality of branch channels connected to the cavity, and the branch channels gradually shrink along the flow direction.

2. The ball precision machining device according to claim 1, characterized in that: The axis of the branch flow channel forms an angle of 20° to 45° with the radial direction in which it is located, and the workpiece (6) is caused to rotate counterclockwise by the impact of the abrasive flow (10).

3. The ball precision machining device according to claim 1, characterized in that: A sealing component is provided between the butt joint surfaces of the two hemispherical bodies (7, 9) for sealing.

4. The ball precision machining device according to claim 1, characterized in that: Also includes a control system, a vibration sensor (5) and a pressure sensor; A plurality of vibration sensors (5) are installed on the inner wall of the cavity to detect vibration signals generated by the abrasive flow (10); The pressure sensor is used to detect the pressure of the abrasive flow (10) output by the circulation device; The control system adjusts the output pressure of the circulation device according to the vibration signal.

5. A processing method of a ball precision processing device according to any one of claims 1 to 4, characterized in that: The steps include: The workpiece (6) is placed in the cavity, and the hemispherical bodies (7, 9) are sealed and installed; Pumping abrasive flow (10) to the cavity grinding workpiece (6) through a circulation device; A plurality of vibration sensors (5) detect vibration signals generated by the abrasive flow (10), and a control system adjusts the output pressure of the circulation device according to the vibration signals; After the grinding process is completed, the workpiece (6) is taken out to check whether the shape accuracy and surface quality meet the set requirements. If not, it is put back into the cavity for processing.

6. The processing method of the ball precision processing device according to claim 5, characterized in that: The control system adjusts the output pressure of the circulation device according to the vibration signal, specifically: The initial state sets the output pressure of the circulation device to P0. After processing time t1, the control system calculates the average value S of several vibration signals. t1 Compared with the first set value, when the average value S t1 When it is less than the first set value, the grinding process is completed; When the average value S t1 When the pressure is greater than the first set value, the control system increases the output pressure of the circulation device to P1; after adjusting the pressure for t2 time, when the average value S t2 is greater than the first set value, and the average value S t2 Less than the average value S t1 When the output pressure of the circulation device is reduced to P2, and P1>P2>P0; until the average value S t1 is smaller than the first set value.