Continuous grinding equipment for shaft external spiral structure

Abstract

The utility model discloses continuous grinding equipment for shaft external spiral structures, belongs to the precision grinding technology, and aims to solve the problems that the grinding efficiency of the conventional shaft external spiral structures such as external threads, lead screw channels and the like is low and the cost is high. The dresser dresses the grinding wheel to form a plurality of annular grinding blades, then the annular grinding blades are utilized to grind the circumferential outer surface of the guide wheel on site to form a plurality of spaced annular grooves or annular ridges, the shaft type external spiral part is matched with the annular grooves or annular ridges of the guide wheel so as to be radially positioned, and the part is controlled to rotate and axially move. During grinding, the axis of the guide wheel and the axis of the grinding wheel intersect with the axis of the part and keep an included angle of a lead angle, the guide wheel and the grinding wheel rotate in the same direction to drive the part to rotate, through type centerless continuous grinding that the multiple parts are input from one end of the guide wheel and output from the other end of the guide wheel is achieved, and the grinding efficiency is improved on the premise that the precision is guaranteed.

Description

Technical Field

[0001] This utility model belongs to the field of precision grinding technology, specifically relating to a special-function centerless grinding machine used for continuous grinding of the shaped spiral regular outer surface of shaft parts. More specifically, it is a special grinding machine for efficient grinding of spiral structures such as all external threads, lead screw channels, and trapezoidal threads of the same specification. Background Technology

[0002] The patent document CN101433984A, entitled "Centerless Ball Screw Grinding Machine and Grinding Process Thereof," discloses the idea of ​​using a centerless grinder to grind ball screws. However, the principle behind this invention is flawed, and it is practically impossible. Whether grinding external threads or ball screw channels, the ultimate goal is to improve the accuracy of the threads or channels. The process described in this patent document cannot achieve precise ratio control of the rotation angle and axial displacement of the part during grinding. Circumferential slippage between the grinding wheel and guide wheel and the part will affect the rotational accuracy of the part. Furthermore, the axial displacement lacks a strict reference and a precise displacement mechanism, making precise control of axial movement impossible. Grinding in this manner may actually worsen the problem.

[0003] Current grinding processes for shaft-type external helical structures (such as external threads, lead screw channels, trapezoidal lead screws, etc.) are intermittent, one-by-one grinding. This means that after machining one part, the process involves retracting the tool, unloading, loading, aligning the groove, moving along the transverse guide, feeding, and grinding again, resulting in extremely low efficiency. With the rise of humanoid robots, robotic dogs, and automotive electromechanical braking (EMB), the demand for planetary ball screws will experience explosive growth. For external helical shaft-type parts like planetary ball screws, where the helical rollers and outer diameter are all of the same specification with full threads, the existing technology, if applied to mass production, cannot meet the market's quantity and price demands. Utility Model Content

[0004] This invention addresses the challenges of low efficiency and high cost in grinding shaft-type external helical parts of the same specification using existing external thread grinding machines. It provides a continuous grinding equipment for shaft-type external helical structures, suitable for mass grinding of shaft-type external helical parts with the same outer diameter. Production efficiency can be increased by tens or even hundreds of times, greatly reducing production costs and promoting the industrialization and popularization of humanoid robots, robot dogs, automotive electromechanical braking (EMB), etc.

[0005] To achieve the above objectives, the present invention provides a shaft-type external helical continuous grinding equipment, characterized by comprising:

[0006] Grinding wheels and guide wheels are arranged on the left and right radial sides of the machined shaft-type external helical part, and a support device is arranged on the lower radial side of the machined shaft-type external helical part. The grinding wheels are configured such that their axis of rotation can be adjusted at an angle and fastened in a first vertical plane parallel to the axis of rotation of the part on one side of the axis of rotation of the part. The guide wheels are configured such that their axis of rotation can be adjusted at an angle and fastened in a second vertical plane parallel to the axis of rotation of the part on the other side of the axis of rotation of the part.

[0007] A dresser disposed near a grinding wheel and movable radially and / or axially relative to the grinding wheel, the dresser being used to shape and dress the grinding wheel;

[0008] in,

[0009] At least one of the grinding wheel and the guide wheel can move in the radial direction to achieve radial feed, the radial direction being perpendicular to the axis of the workpiece;

[0010] At least one of the grinding wheel and the guide wheel can be moved in the axial direction to achieve in-situ axial forming grinding of the entire outer surface of the guide wheel by the grinding wheel, wherein the axial direction is parallel to the axis of the part.

[0011] This invention constructs a guide wheel with an annular groove or ridge on one radial side of the machined shaft-type external helical part. The guide wheel's normal shape matches the helical structure of the part, and the distance between adjacent guide wheel annular grooves or ridges along the part's axis is equal to or an integer multiple of the helical groove distance. This guide wheel has no helix angle, allowing the part's thread to mesh with the guide wheel's annular groove or ridge, achieving reverse rolling. A grinding wheel is positioned on the other radial side of the part, with a positioning cutter plate underneath the outer radial side to ensure part positioning. The guide wheel enables radial positioning, rotation control, and axial movement of the part. The forming grinding wheel can feed radially from the part, thus achieving continuous grinding of the helical structure part. This constitutes a centerless grinder capable of continuous grinding of CNC external helical structures. While ensuring accuracy, this increases efficiency by tens or even hundreds of times, while drastically reducing costs.

[0012] Preferably, the grinding wheel is coaxially mounted on a first spindle for being driven to rotate. The first spindle is mounted on a first spindle seat, which is directly or indirectly mounted on a first component. The first component is configured to allow the grinding wheel axis to be tilted at an adjustable angle and secured within the first vertical plane. The first component is directly or indirectly mounted on a first slide, which is directly or indirectly mounted on the bed. The first slide is driven by a first driver to enable the machined shaft-type external helical part to move radially relative to the bed.

[0013] Preferably, the guide wheel can be driven to rotate by a second spindle, the second spindle is mounted on a second spindle seat, the second spindle seat is directly or indirectly mounted on a second component, the second component is configured to allow the guide wheel axis to adjust the tilt angle and be fastened in a second vertical plane, the second component is directly or indirectly mounted on a second slide, the second slide is directly or indirectly mounted on the bed, and the second drive drives the second slide to enable the machined shaft-type external helical part to move relative to the bed in the axial direction.

[0014] Therefore, in the axial direction of the part, the guide wheel is moved axially while the grinding wheel remains stationary. This facilitates the grinding wheel grinding the entire outer surface of the guide wheel. In the radial direction of the part, the grinding wheel is moved radially while the guide wheel remains stationary. This allows for radial feed while reducing factors affecting the grinding diameter accuracy.

[0015] If necessary, a manually adjustable slide rail can be added between the second component and the second slide plate to allow the guide wheel to move slightly in the radial direction, in order to adapt to the processing and adjustment of parts with different diameters. During actual grinding, this part is locked so that the guide wheel does not move in the radial direction of the part.

[0016] Preferably, the grinding wheel has an annular grinding edge without a helix angle, the annular grinding edge having a concave-convex shape consistent with the helical groove normal morphology of the machined shaft-type external helical part, and the distance between the centers of adjacent annular grinding edge morphologies in the direction of the part's axis of rotation is equal to the helical groove pitch of the machined shaft-type external helical part; the guide wheel has annular grooves or annular ridges with no helix angle, the annular grooves or annular ridges matching the concave-convex shape of the helical structure normal morphology of the machined shaft-type external helical part, and the distance between adjacent annular grooves or annular ridges in the direction of the part's axis of rotation is equal to or an integer multiple of the helical groove pitch of the machined shaft-type external helical part.

[0017] Preferably, the centerline of the part is arranged horizontally; the first vertical plane is a vertical plane, and the adjustable tilt angle of the grinding wheel centerline in the first vertical plane is ±30° with the horizontal plane; the second vertical plane is a vertical plane, and the adjustable tilt angle of the guide wheel centerline in the second vertical plane is ±30° with the horizontal plane.

[0018] Preferably, the support device is equipped with a support structure that contacts the radially lower side of the shaft-type external helical part, so that the part is close to the guide wheel, and the support structure is an inclined surface or a curved surface.

[0019] Preferably, the dresser is disposed directly or indirectly on the first component. This allows the dresser and the first component to be synchronously angled and secured around the rotation center axis.

[0020] It can also be directly or indirectly mounted on the second slide, which not only simplifies the trimming system but also improves trimming accuracy.

[0021] Preferably, the width of the annular groove or ridge on the guide wheel in the axial direction of the part is an integer multiple of the pitch of the helical structure part. This is particularly suitable for guiding fully helical structure parts with small pitches, i.e., one annular groove or ridge can span the pitches of two or more helical structure parts.

[0022] Preferably, the dresser can be a forming diamond roller driven coaxially by an electric spindle and a synchronous shaft, or a diamond dressing disc or diamond pen driven coaxially by an electric spindle and a synchronous shaft. It utilizes two cross-shaped servo-driven guide rails arranged radially and / or axially in the same direction as the grinding wheel's axis to dress the shaped surface of the grinding wheel. If necessary, linear encoders can be installed on the guide rails of these two dressers to provide "closed-loop" precise control of the dimensions during the dressing process.

[0023] In particular, because the grinding wheel performs in-situ axial forming grinding on the entire outer surface of the guide wheel, the resulting guide wheel mold reduces various dimensional chain errors and achieves extremely high overall form and position accuracy. More importantly, during the forming grinding of the guide wheel, the grinding wheel and the guide wheel can be precisely aligned in the axial direction of the part, with an accuracy down to the micrometer level.

[0024] Preferably, linear grating rulers are installed between the first slide and the bed or the fasteners fixed to the bed, and between the second slide and the bed or the fasteners fixed to the bed, to perform precise "closed-loop" control on the radial movement of the grinding wheel and the axial movement of the guide wheel, thereby improving the accuracy of the machined parts.

[0025] Preferably, the support device is directly or indirectly mounted on the second slide or bed. The support device is equipped with a support structure that contacts the radially lower side of the shaft-type external helical part, bringing the part close to the mold guide wheel. The support structure is an inclined plane or a curved surface. Taking an inclined plane as an example, the inclined plane maintains an angle with the horizontal plane, bringing the part close to the mold guide wheel. Specifically, the angle φ between the inclined plane and the horizontal plane is between 0 and 45°, and can be optimized as needed.

[0026] Preferably, a pressure roller or stop bar parallel to the part is arranged above the part to ensure smooth operation during grinding.

[0027] Preferably, a rotatable first component is configured to adjust and secure the tilt angle of the grinding wheel axis in the first vertical plane, and a rotatable second component is configured to adjust and secure the tilt angle of the guide wheel axis in the second vertical plane, ensuring that the rotation center axis of the first component, the rotation center axis of the second component, and the workpiece axis are in the same plane; depending on the number of spiral heads on the workpiece, the mutual spacing between the rotation center axes of the first and second components in the workpiece axis direction within this plane is precisely set, thereby improving V... 300 The accuracy of the spiral.

[0028] During grinding, the lead angle α of the helical structure at the contact point between the workpiece surface and the guide wheel annular groove or ridge, and the grinding wheel annular grinding edge, is parallel to the radial plane (i.e., a plane passing through the center of the contour and perpendicular to the axis of the guide wheel or grinding wheel) of the guide wheel annular groove or ridge and the grinding wheel annular grinding edge. Furthermore, the linear velocity direction of the guiding rotation is opposite to the linear velocity direction of the grinding rotation. The guiding rotation is the rotation direction at the contact point between the guide wheel annular groove or ridge and the helical structure on the workpiece surface, while the grinding rotation is the rotation direction at the contact point between the grinding wheel cutting edge and the helical structure on the workpiece surface. Thus, the workpiece is supported by a support device below and rotated to the left and right by the opposite linear velocity directions of the guide wheel and the grinding wheel, causing the workpiece to rotate circumferentially while simultaneously moving axially at a precise ratio, achieving through-grinding.

[0029] Preferably, grinding fluid is sprayed in the grinding zone to reduce the temperature of the grinding zone and improve the dimensional accuracy and surface quality of the machined shaft-type external helical parts.

[0030] Preferably, the grinding wheel is made of CBN grinding wheel or SG grinding wheel, which extends the durability of the grinding wheel.

[0031] To achieve the above objectives, the external helical structure of the shaft of this utility model is subjected to the following continuous grinding method.

[0032] The part to be ground is placed between a guide wheel and a grinding wheel and supported by a support device below. The tilt angle of the guide wheel's axis is adjustable in a plane parallel to and including the part's axis. The tilt angle of the grinding wheel's axis is also adjustable in a plane parallel to and including the part's axis. The guide wheel and grinding wheel can move relative to each other in the axial and radial directions of the part. The circumferential surface of the guide wheel has several spaced annular grooves or ridges without helix angle. The spaced annular grooves or ridges engage with the helical structure of the part to be ground, allowing the guide wheel to rotate circumferentially while simultaneously moving the part axially through the grinding zone relative to the guide wheel. The grinding wheel is shaped and dressed by a dresser located radially outside the grinding wheel and can move radially and / or axially relative to the grinding wheel. The outer circumferential surface of the grinding wheel has several annular grinding edges without helix angle, allowing the annular grinding edges to grind the helical structure of the part according to a set position and angle.

[0033] Its characteristics are: the dresser dresses the grinding wheel to form several annular grinding edges, and then uses the annular grinding edges to grind the outer circumference of the guide wheel in place to form several spaced annular grooves or annular ridges.

[0034] This method only uses a grinding wheel forming dresser and does not have a guide wheel dresser, which simplifies the structure. The outer circumference of the guide wheel is formed and shaped by the forming grinding wheel in situ, which improves the dressing efficiency and accuracy.

[0035] Preferably, the normal cross-sectional profile of the annular grinding blade is convex or concave; the profile of the annular grinding blade when dressing the guide wheel is the same as or different from the profile when grinding the part.

[0036] Preferably, in a plane containing the centerline of the part and parallel to the centerline of the guide wheel, the angle between the vertical projection line of the guide wheel's centerline and the centerline of the part is the lead angle α of the external helical structure of the shaft; in a plane containing the centerline of the part and parallel to the centerline of the grinding wheel, the angle between the vertical projection line of the grinding wheel's centerline and the centerline of the part is also the lead angle α of the external helical structure of the shaft.

[0037] Preferably, the plane containing the part's axis of rotation and parallel to the guide wheel's axis of rotation and the plane containing the part's axis of rotation and parallel to the grinding wheel's axis of rotation are the same plane.

[0038] Preferably, when the grinding wheel dresses the guide wheel, the vertical projection line of the guide wheel axis in the plane containing the workpiece axis and the vertical projection line of the grinding wheel axis in the plane containing the workpiece axis are inclined in the same direction with a lead angle α relative to the workpiece axis; when the grinding wheel grinds the workpiece, the vertical projection line of the guide wheel axis in the plane containing the workpiece axis and the vertical projection line of the grinding wheel axis in the plane containing the workpiece axis intersect and are inclined in the opposite direction with an angle α relative to the workpiece axis, that is, the angle between the vertical projection line of the wheel axis in the plane containing the workpiece axis and the vertical projection line of the grinding wheel axis in the plane containing the workpiece axis is 2α lead angle.

[0039] Preferably, the circumferential outer surface of the guide wheel is formed by in-situ grinding and dressing by a grinding wheel, so that the guide wheel has several annular grooves or annular ridges with no helix angle. The normal cross-sectional profile of the annular groove or annular ridge matches the normal profile of the helical structure at the contact point with the part. In the axial direction of the part, the axial dimension of the center of the profile of the adjacent annular groove or annular ridge is equal to or an integer multiple of the helical groove distance or groove distance of the adjacent part being machined.

[0040] Preferably, the normal cross-sectional profile of the annular grinding edge is made to be consistent with the normal cross-sectional profile of the helical structure of the workpiece, and in the axial direction of the workpiece, the distance between the centers of adjacent annular grinding edge profiles is equal to the distance between adjacent helical grooves of the helical structure of the workpiece.

[0041] Preferably, when grinding a part, the theoretical normal plane at the contact point between the annular groove or annular ridge of the guide wheel and the part is made parallel to the axis of the guide wheel, and the theoretical normal plane at the contact point between the annular grinding edge and the part is made parallel to the axis of the grinding wheel.

[0042] This invention constructs a guide wheel on one side of the radial direction of the external helical part of the shaft being processed. The guide wheel's annular groove or ridge matches the normal shape of the helical structure of the external helical part, and the distance between adjacent guide wheel annular grooves or ridges in the axial direction of the part is equal to or an integer multiple of the helical groove distance. The guide wheel has no helix angle, allowing the helical structure of the part to mesh with the guide wheel's annular groove or ridge, achieving reverse rolling. The grinding wheel is constructed on the other side of the radial direction of the part, and a positioning cutter is set under the outer radial side of the part to ensure part positioning. The guide wheel achieves radial positioning, rotation control, and axial movement of the part. The forming grinding wheel can feed from the radial direction of the part, thereby achieving continuous grinding of the helical structure part through the entire shaft. While ensuring accuracy, the efficiency is increased by tens or even hundreds of times, and the cost is drastically reduced.

[0043] This invention utilizes a grinding wheel to perform in-situ axial forming grinding on the entire outer surface of a guide wheel. The resulting guide wheel mold reduces various dimensional chain errors and achieves extremely high overall form and position accuracy. More importantly, during the grinding of the guide wheel, the grinding wheel and guide wheel can be precisely aligned in the axial direction of the part using a CNC program, achieving an accuracy down to the micrometer level. Attached Figure Description

[0044] Figure 1 This is an isometric view of the shaft-type external helical structure continuous grinding equipment of this utility model;

[0045] Figure 2 This is a schematic diagram of an orthographic projection from one perspective of the continuous grinding equipment for shaft-type external helical structures according to this utility model;

[0046] Figure 3 for Figure 2 The left view;

[0047] Figure 4 for Figure 2 A schematic diagram of the right-view direction removing the trimmer in orthographic projection;

[0048] Figure 5 for Figure 2 A schematic diagram of the structure after the second component has been removed;

[0049] Figure 6 for Figure 2 The diagram shown is a schematic diagram after removing the first component, the first driver, and the first slide plate.

[0050] Figure 7 This is a schematic diagram showing the axial positional relationship of the parts, guide wheel, grinding wheel, and support device of this utility model.

[0051] Figure 8 The guide wheel and grinding wheel of this utility model are relative to each other. Figure 7A schematic diagram of the positional relationship from the left-hand perspective;

[0052] Figure 9 This is a schematic diagram of the axial structure of a support device according to the present invention;

[0053] Figure 10 This is a schematic diagram showing the relative position of the external helical shaft part and the grinding wheel of this utility model;

[0054] Figure 11 This is a schematic diagram showing the relative positions of the external helical shaft part and the mold guide wheel of this utility model;

[0055] Figure 12 This is a schematic diagram showing the engagement of a part with a guide wheel;

[0056] Figure 13 for Figure 12 A cross-sectional schematic diagram showing the meshing of the component with the guide wheel;

[0057] Figure 14 This is a schematic diagram showing the meshing of a component with another type of guide wheel;

[0058] Figure 15 for Figure 14 A schematic cross-sectional view showing the part meshing with the guide wheel;

[0059] Figure 16 This is a schematic diagram of another support device of the present invention along the axial direction;

[0060] Explanation of the labels in the diagram:

[0061] 1. External helical part of shaft type, 101. Part axis, 2. Grinding wheel, 201. Grinding wheel axis, 202. Annular grinding edge, 3. Guide wheel, 301. Guide wheel axis, 302. Annular groove or annular ridge, 4. Support device, 401. Inclined surface, 5. Dresser, 6. First spindle, 7. First spindle seat, 8. First component, 801. Rotation center axis of the first component, 9. First slide, 10. First driver, 11. Second spindle, 12. Second spindle seat, 13. Second component, 131. Rotation center axis of the second component, 14. Second slide, 15. Second driver, 16. Bed, P. First vertical plane, Q. Second vertical plane, α. Lead angle, W1. Axial width of annular groove or annular ridge, W2. Helical groove pitch of helical structure part. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0063] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this utility model are intended to cover non-exclusive inclusion, such as a method or product that includes a series of technical features, not limited to those technical features explicitly listed, but also including other technical features that may be included in the method or product but not explicitly listed.

[0064] In the description of this utility model, it should be understood that the technical features defined by terms such as "first" and "second" which have a sequential concept are only for the purpose of clearly describing the defined technical features and making the defined technical features clearly distinguishable from other technical features, and do not represent that they are named in this way in actual implementation. Therefore, they should not be construed as limitations on this utility model.

[0065] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0066] like Figure 1-7 As shown, the shaft-type external helical structure continuous grinding equipment includes a grinding wheel 2, a guide wheel 3, a support device 4, and a dresser 5.

[0067] Grinding wheel 2 and guide wheel 3 are separately positioned on the left and right radial sides of the machined shaft-type external helical part 1. Support device 4 is positioned on the lower radial side of the machined shaft-type external helical part 1. Grinding wheel 2 is configured such that its axis 201 can be adjusted at an angle and secured within a first vertical plane P parallel to and on one side of the part's axis 101. Guide wheel 2 is configured such that its axis 301 can be adjusted at an angle and secured within a second vertical plane Q parallel to and on the other side of the part's axis 101.

[0068] The dresser 5 is configured near the grinding wheel 2 and can move radially and / or axially relative to the grinding wheel to shape and dress the grinding wheel 2.

[0069] in:

[0070] The grinding wheel 2 has an annular grinding edge 202 without a helix angle. The annular grinding edge 202 is consistent with the normal shape of the helical groove of the machined shaft-type external helical part 1. The distance between the centers of adjacent annular grinding edges 202 in the direction of the part's axis 101 is equal to the helical groove distance of the machined shaft-type external helical part.

[0071] The guide wheel 3 has an annular groove or annular ridge without a helix angle. The annular groove or annular ridge matches the concave-convex shape of the helical structure normal of the machined shaft-type external helical part 1. The groove distance between adjacent annular grooves or annular ridges in the direction of the part's axis 101 is equal to or an integer multiple of the helical groove distance of the machined shaft-type external helical part.

[0072] At least one of the grinding wheel 2 and the guide wheel 3 can move in the radial direction to achieve radial feed, the radial direction being perpendicular to the workpiece axis 101;

[0073] At least one of the grinding wheel 2 and the guide wheel 3 can be moved in the axial direction to achieve in-situ axial forming grinding of the entire outer surface of the guide wheel 3 by the grinding wheel 2, wherein the axial direction is parallel to the axis 101 of the part.

[0074] During grinding, both the grinding wheel 2 and the guide wheel 3 make contact with the blank helical structure of the shaft-type external helical part 1 being processed, and achieve opposite rolling rotation with the shaft-type external helical part 1 being processed, thereby realizing the radial positioning of the part, controlling the circumferential rotation direction and speed of the part, and the axial movement of the part.

[0075] This invention constructs an annular groove or annular ridge guide wheel on one radial side of the external helical part of the shaft being machined. The guide wheel's normal shape matches the helical structure of the external helical part, and the adjacent guide wheel groove spacing in the axial direction of the part is equal to or an integer multiple of the helical groove spacing. This allows the helical structure of the part to mesh with the annular groove or annular ridge of the guide wheel, achieving reverse rolling. The grinding wheel is constructed on the other radial side of the part, and a positioning cutter is set under the outer radial side of the part to ensure part positioning. The guide wheel achieves radial positioning, rotation control, and axial movement of the part. The forming grinding wheel can feed from the radial direction of the part, thereby achieving continuous grinding of the helical structure part through the entire shaft. While ensuring accuracy, the efficiency is increased by tens or even hundreds of times, and the cost is drastically reduced.

[0076] like Figure 11-14 As shown, the groove pitch W1 (axial width of the annular groove or annular ridge 302) of adjacent annular grooves or annular ridges in the direction of the part's axis 101 is equal to or an integer multiple of the helical groove pitch W2 of the machined shaft-type external helical part. This is particularly suitable for guiding fully helical structural parts with small pitches, i.e., one annular groove or annular ridge can span the pitches of two or more helical structural parts.

[0077] The dresser 5 can be a forming diamond roller driven coaxially by an electric spindle and a synchronous shaft, or a diamond dressing disc or diamond pen driven coaxially by an electric spindle and a synchronous shaft. It uses two cross-shaped servo-driven guide rails arranged radially and / or axially in the same direction as the axis of the grinding wheel to interpolate and dress the forming surface of the grinding wheel. If necessary, linear grating rulers can be installed on the guide rails of these two dressers to provide "closed-loop" precise control of the dimensions during the dressing process.

[0078] The dresser 5 can also be mounted on the second slide, which can make full use of the existing guide rail movement under the guide wheel and under the grinding wheel to dress the grinding wheel; this simplifies the structure and allows for precise "closed-loop" control using the linear grating ruler of the guide wheel and grinding wheel guide rail with higher precision.

[0079] In particular, because the grinding wheel performs in-situ axial forming grinding on the entire outer surface of the guide wheel 3, the resulting guide wheel mold reduces various dimensional chain errors and achieves extremely high overall dimensional and positional accuracy. More importantly, during the forming grinding of the guide wheel 3, the CNC system of the machine tool can precisely align the grinding wheel and the guide wheel 3 in the axial direction of the part, achieving an accuracy down to the micrometer level.

[0080] The grinding wheel 2 is coaxially mounted on the first spindle 6 and driven to rotate. The first spindle 6 is mounted on the first spindle seat 7. The first spindle seat 7 is directly or indirectly mounted on the first component 8. The first component 8 is configured to allow the grinding wheel axis 201 to adjust the tilt angle and be fastened in the first vertical plane P. The first component 8 is directly or indirectly mounted on the first slide 9. The first slide 9 is directly or indirectly mounted on the bed 16. The first drive 10 drives the first slide 9 to make the machined shaft-type external helical part 1 movable relative to the bed 16 in the radial direction.

[0081] The guide wheel 3 can be driven to rotate by the second spindle 11. The second spindle 11 is mounted on the second spindle seat 12. The second spindle seat 12 is directly or indirectly mounted on the second component 13. The second component 13 is configured to allow the guide wheel axis 301 to adjust the tilt angle and be fastened in the second vertical plane Q. The second component 13 is directly or indirectly mounted on the second slide 14. The second slide 14 is directly or indirectly mounted on the bed 16. The second drive 15 drives the second slide 14 to make the machined shaft-type external helical part 1 movable relative to the bed 16 in the axial direction.

[0082] Therefore, in the axial direction of part 1, the guide wheel 3 is moved axially while the grinding wheel 2 remains stationary. This facilitates the grinding wheel 2 grinding the entire outer surface of the guide wheel. In the radial direction of part 1, the grinding wheel 2 is moved radially while the guide wheel 3 remains stationary. This allows for radial feed while reducing factors affecting the grinding diameter accuracy.

[0083] If necessary, a manually adjustable slide rail can be added between the second component 13 and the second slide plate 14 to allow the guide wheel 3 to move slightly in the radial direction, so as to adapt to the processing adjustment of parts with different diameters. During actual grinding, this part is locked so that the guide wheel 3 does not move in the radial direction of the part 1.

[0084] Linear grating rulers are installed between the first slide 9 and the bed 16 or the fasteners fixed to the bed, and between the second slide 14 and the bed 16 or the fasteners fixed to the bed, to perform precise "closed-loop" control on the radial movement of the grinding wheel 2 and the axial movement of the guide wheel 3, thereby improving the accuracy of the machined parts.

[0085] like Figure 9-10 As shown, the part's axis 101 is horizontally arranged. The first vertical plane P is a vertical plane, and the adjustable tilt angle of the grinding wheel axis 201 within the first vertical plane P is ±30° with respect to the horizontal plane. The second vertical plane Q is a vertical plane, and the adjustable tilt angle of the guide wheel axis 301 within the second vertical plane is ±30° with respect to the horizontal plane. Therefore, in practical use, the tilt angle values ​​of the grinding wheel axis 201 and the guide wheel axis 301 relative to the horizontal plane of the part's axis 101 are consistent with the lead angle of the helical structure of the machined shaft-type external helical part, improving the normal morphology accuracy of helical structure grinding and the positioning accuracy of the helical structure part.

[0086] Specifically, in the plane containing the part's axis of rotation and parallel to the guide wheel's axis of rotation, the angle between the vertical projection line of the guide wheel's axis of rotation and the part's axis of rotation is the lead angle α of the external helical structure of the shaft; similarly, in the plane containing the part's axis of rotation and parallel to the grinding wheel's axis of rotation, the angle between the vertical projection line of the grinding wheel's axis of rotation and the part's axis of rotation is also the lead angle α of the external helical structure of the shaft. The plane containing the part's axis of rotation and parallel to the guide wheel's axis of rotation and the plane containing the part's axis of rotation and parallel to the grinding wheel's axis of rotation are the same plane. When the grinding wheel dresses the guide wheel, the vertical projection line of the guide wheel axis in the plane containing the workpiece axis and the vertical projection line of the grinding wheel axis in the plane containing the workpiece axis are inclined in the same direction with a lead angle α relative to the workpiece axis. When the grinding wheel grinds the workpiece, the vertical projection line of the guide wheel axis in the plane containing the workpiece axis and the vertical projection line of the grinding wheel axis in the plane containing the workpiece axis intersect and are inclined in the opposite direction with an angle α relative to the workpiece axis. That is, the angle between the vertical projection line of the guide wheel axis in the plane containing the workpiece axis and the vertical projection line of the grinding wheel axis in the plane containing the workpiece axis is 2α times the lead angle.

[0087] The circumferential outer surface of the guide wheel is formed by in-situ grinding and dressing by the grinding wheel, so that the guide wheel has several annular grooves or annular ridges with no helix angle. The normal cross-sectional profile of the annular groove or annular ridge matches the normal profile of the helical structure at the contact point with the part. In the axial direction of the part, the axial dimension of the center of the profile of the adjacent annular groove or annular ridge is equal to or an integer multiple of the helical groove distance or groove distance of the adjacent part being machined.

[0088] Make the normal cross-sectional profile of the annular grinding edge consistent with the normal cross-sectional profile of the helical structure of the workpiece. In the axial direction of the workpiece, the distance between the centers of the profiles of adjacent annular grinding edges is equal to the distance between adjacent helical grooves of the helical structure of the workpiece.

[0089] When grinding a part, the theoretical normal plane at the contact point between the annular groove or annular ridge of the guide wheel and the part is made parallel to the axis of the guide wheel, and the theoretical normal plane at the contact point between the annular grinding edge and the part is made parallel to the axis of the grinding wheel.

[0090] The support device 4 is directly or indirectly mounted on the second slide 14 or the bed 16. The support device 4 is equipped with a support structure that contacts the radially lower side of the shaft-type external helical part 1, bringing the part 1 close to the mold guide wheel 3. For example... Figure 8 As shown, the support structure is an inclined plane 401. In other embodiments, the support structure can be a roller or a curved surface 402. Taking the inclined plane as an example, the inclined plane 401 maintains an angle φ with the horizontal plane, so that part 1 is close to the mold guide wheel 3. Specifically, the angle φ between the inclined plane 401 and the horizontal plane is between 0 and 45°, and can be optimized as needed. When the support structure is a curved surface, such as... Figure 16 As shown, in a plane perpendicular to the axis 101 of the part, the angle β between the line connecting the contact point of the curved surface 402 and the part 1 to the axis of the part and the vertical line is 0 to 45°.

[0091] Above the part, a pressure roller or stop bar is set parallel to the part to ensure smooth operation during grinding.

[0092] A rotatable first component 8 is configured to adjust and secure the tilt angle of the grinding wheel axis 201 within the first vertical plane P. A rotatable second component 13 is configured to adjust and secure the tilt angle of the guide wheel axis 301 within the second vertical plane Q. This ensures that the rotational center axes of the first and second components and the workpiece axis are in the same plane. Depending on the number of spiral heads on the workpiece, the relative distance between the rotational center axes of the first and second components in the workpiece axis direction within this plane is precisely set, thereby improving V... 300 The accuracy of the spiral.

[0093] During grinding, the lead angle α of the helical structure at the contact point between the workpiece surface and the guide wheel annular groove or ridge, and the grinding wheel annular grinding edge, is parallel to the radial plane containing the center of the contour of the guide wheel annular groove or ridge and the grinding wheel annular grinding edge (i.e., a plane passing through the center of the contour and perpendicular to the axis of the guide wheel or the axis of the grinding wheel). Furthermore, the linear velocity direction of the guiding rotation is opposite to the linear velocity direction of the grinding rotation. The guiding rotation is the rotation direction at the point where the guide wheel annular groove or ridge contacts the helical structure on the workpiece surface, while the grinding rotation direction is the rotation direction at the point where the grinding wheel cutting edge contacts the helical structure on the workpiece surface. Thus, the workpiece is supported from below by a support device and rotates left and right by the opposite linear velocity directions of the guide wheel and the grinding wheel, causing the workpiece to rotate axially while simultaneously moving axially at a precise ratio, achieving through-grinding.

[0094] Grinding fluid is sprayed in the grinding zone to reduce the temperature of the grinding zone and improve the dimensional accuracy and surface quality of the machined shaft-type external helical parts.

[0095] The trimmer 5 is directly or indirectly mounted on the first component 8 so that the trimmer 5 and the first component 8 can be synchronously adjusted and fastened around the rotation center axis 801.

[0096] The dresser 5 can also be mounted on the second slide, which can make full use of the existing guide rail movement under the guide wheel and under the grinding wheel to dress the grinding wheel; this simplifies the structure and allows for precise "closed-loop" control using the linear grating ruler of the guide wheel and grinding wheel guide rail with higher precision.

[0097] Grinding wheel 2 uses CBN grinding wheels or SG grinding wheels, etc., to extend the durability of the grinding wheel.

[0098] The continuous grinding machine for external threads and lead screw grooves with the above structure can perform guide wheel dressing, machine tool adjustment, and thread grinding.

[0099] I. Guide wheel dressing

[0100] Based on the direction of the spiral structure and the magnitude of the lead angle of the part, adjust the tilt direction and angle of the guide wheel axis to make the spiral direction of the repaired annular groove or annular ridge consistent with the spiral structure contact point and the shape matching.

[0101] Adjust the tilt direction and angle of the grinding wheel's axis of inclination to align with the guide wheel at the same angle.

[0102] Start the grinding wheel and dresser, and dress several annular grinding edges to the desired convex or concave shape as required (when grinding annular grooves or annular ridges on the guide wheel in situ, it is recommended to use single-edge cutting of the grinding edge).

[0103] Start the guide wheel to rotate;

[0104] Move the guide wheel along the axis of the part to gradually adjust the guide wheel from one side of its axial end face to the other side; move the grinding wheel along the radial direction of the part to feed or retract the grinding wheel relative to the guide wheel.

[0105] The first driver drives the grinding wheel to feed radially, grinding the guide wheel with annular grooves or ridges. After grinding one annular groove or ridge, the first driver reverses its action to drive the grinding wheel to retract radially. According to the groove pitch of the helical structure of the part, the second driver drives the guide wheel to move along the axial direction of the part to another unground direction by one groove pitch. The first driver then drives the grinding wheel to feed radially again to grind the second annular groove or ridge. This process continues until the guide wheel is completely ground. The radial feed dimension termination position of the grinding wheel on all annular grooves or ridges of the guide wheel can be kept the same, or different radial dimensions can be set as needed. That is, the annular grinding edge is used to grind the outer circumference of the guide wheel in situ to form several spaced annular grooves or ridges. Furthermore, the contour shape of the guide wheel when the annular grinding edge is dressing it is the same as or different from the contour shape when grinding the part.

[0106] II. Machine Tool Adjustment

[0107] Select a cutting tool with appropriate specifications and bevel angle based on the diameter of the external helical shaft being machined;

[0108] Fine-tune the distance between the blade and the guide wheel to ensure that the outer surface of the part and the stress point of the blade are in the appropriate position;

[0109] Adjust the height of the blade so that the workpiece's axis 101, rotation center axis 801, and rotation center axis 131 are at the same horizontal level.

[0110] Adjust the tilt direction and angle of the grinding wheel axis to make the annular direction of the grinding edge consistent with the spiral direction of the cutting point of the spiral structure of the part. The angle value is the lead angle value of the spiral structure of the part. At this time, the grinding wheel axis 201 and the guide wheel axis 301 intersect symmetrically in opposite directions in space with the horizontal plane containing the part axis 101 as the reference.

[0111] Adjust the axial position of the guide rollers so that the rotation center axes 801 and 131 are on the same straight line, or set the distance between the two according to the different requirements of the workpiece being processed, and the CNC program memorizes the alignment position;

[0112] According to the actual normal shape of the helical structure of the part, the grinding wheel is dressed again; all data interpolation is automatically compensated; the distance between two adjacent grinding edges is automatically adjusted according to the lead angle of the helical structure of the part.

[0113] In the feeding and inlet section of the parts, an automatic feeding device is used to achieve continuous feeding; in the receiving and outlet section of the parts, an automatic receiving device is used to achieve automatic receiving and prevent collision damage.

[0114] III. Helical Grinding

[0115] The part to be ground is placed between the guide wheel and the grinding wheel and supported by the support device below;

[0116] Open the grinding fluid valve and spray grinding fluid into the grinding area;

[0117] The parts are continuously and continuously transported to the grinding zone by guide wheels;

[0118] The grinding wheel is fed radially until the helical structure of the part is ground to the desired dimensional requirements.

[0119] Repeat the above grinding process, increasing the radial feed of the grinding wheel by a certain amount each time, until the design requirements are met;

[0120] After grinding a certain number of parts, the CNC program automatically starts the grinding wheel dressing function. The grinding wheel retracts, the guide wheel stops rotating, the grinding wheel is dressed, the grinding wheel is fed back, and the guide wheel rotates again. The change in the size of the grinding wheel caused by the grinding wheel dressing is automatically compensated by the CNC program, and the grinding continues in sequence.

[0121] As described above, the part to be ground is placed between a guide wheel and a grinding wheel and supported by a lower support device. The tilt angle of the guide wheel's axis in a plane parallel to and including the part's axis is adjustable, as is the tilt angle of the grinding wheel's axis in a plane parallel to and including the part's axis. The guide wheel and grinding wheel can move relative to each other in the axial and radial directions of the part. The circumferential surface of the guide wheel has several spaced annular grooves or ridges without a helix angle. These spaced annular grooves or ridges engage with the helical structure of the part to be ground, causing the guide wheel to... As the part rotates circumferentially, it moves axially through the grinding zone relative to the guide wheel. The grinding wheel is shaped and dressed by a dresser, which is located radially outward near the grinding wheel and can move radially and / or axially relative to the grinding wheel. The outer circumference of the grinding wheel has several annular grinding edges without helix angle. The annular grinding edges grind the helical structure of the part according to the set position and angle. The dresser dresses the grinding wheel to form several annular grinding edges, and then uses the annular grinding edges to grind the outer circumference of the guide wheel in situ to form several spaced annular grooves or annular ridges.

[0122] The most prominent feature of this device and method is:

[0123] 1. The shape of the guide wheel of the positioning datum is almost identical to the finished shape of the part to be processed. The distance between each annular groove or annular ridge in the axial direction of the part is completely consistent with the spiral groove distance of the finished part. In particular, the dressing of the guide wheel is simulated by the state of contact between the part and the guide wheel and is processed in place by grinding wheel. The accuracy of the positioning datum can reach the micron level.

[0124] 2. The problem of "rotating and moving precisely and proportionally at the same time" required during grinding is solved by the precision of the guide wheel mold. The more the part rotates, the more it moves axially proportionally, and the less the part rotates, the less it moves axially proportionally. There is no need to worry about slippage at the contact point between the guide wheel and the part.

[0125] 3. Most importantly, the annular grooves or ridges of the guide wheel are CNC dressed by the grinding wheel. The center position of the contour shape of the annular grooves or ridges in the axial direction of the part has a "precise program memory" for the grinding wheel. During grinding, it can drive the center of the contour shape of the grinding wheel to the desired ideal position very accurately. Compared with the traditional centerless grinding machine, which relies on individual shaping and dressing and then visual alignment during adjustment, the method of this utility model can be accurate to the micron level, which is a qualitative leap.

[0126] 4. During grinding, the guide wheel and grinding wheel on both radial sides of the part act as a precision "half mold". The part passing through the grinding area is guaranteed by the "mold".

Claims

1. A continuous grinding machine with an external helical structure for shafts, characterized by: include: Grinding wheels (2) and guide wheels (3) are arranged on the left and right radial sides of the machined shaft-type external helical part (1), and a support device (4) is arranged on the lower radial side of the machined shaft-type external helical part (1). The grinding wheels (2) are configured such that their axis (201) can be adjusted and fastened in a first vertical plane (P) parallel to the axis (101) on one side of the axis (101). The guide wheels (3) are configured such that their axis (301) can be adjusted and fastened in a second vertical plane (Q) parallel to the axis (101) on the other side of the axis (101). A dresser (5) disposed near the grinding wheel (2) and movable radially and / or axially relative to the grinding wheel, the dresser (5) being used to shape and dress the grinding wheel (2); in, At least one of the grinding wheel (2) and the guide wheel (3) can move in the radial direction to achieve radial feed, the radial direction being perpendicular to the workpiece axis (101); At least one of the grinding wheel (2) and the guide wheel (3) can be moved in the axial direction to achieve in-situ axial forming grinding of the entire outer surface of the guide wheel (3) by the grinding wheel (2), the axial direction being parallel to the axis (101) of the part.

2. The device according to claim 1, characterized in that: The grinding wheel (2) is coaxially mounted on the first spindle (6) to be driven to rotate. The first spindle (6) is mounted on the first spindle seat (7). The first spindle seat (7) is directly or indirectly mounted on the first component (8). The first component (8) is configured to allow the grinding wheel axis (201) to adjust the tilt angle and be fastened in the first vertical plane (P). The first component (8) is directly or indirectly mounted on the first slide (9). The first slide (9) is directly or indirectly mounted on the bed (16). The first drive (10) drives the first slide (9) to enable the machined shaft-type external helical part (1) to move in the radial direction relative to the bed (16). The guide wheel (3) can be driven to rotate by the second spindle (11). The second spindle (11) is mounted on the second spindle seat (12). The second spindle seat (12) is directly or indirectly mounted on the second component (13). The second component (13) is configured to allow the guide wheel axis (301) to adjust the tilt angle and be fastened in the second vertical plane (Q). The second component (13) is directly or indirectly mounted on the second slide (14). The second slide (14) is directly or indirectly mounted on the bed (16). The second drive (15) drives the second slide (14) to make the machined shaft-type external helical part (1) movable relative to the bed (16) in the axial direction.

3. The device according to claim 1 or 2, characterized in that: The grinding wheel (2) has an annular grinding edge (202) without a helix angle. The annular grinding edge (202) is consistent with the normal shape of the helical groove of the shaft-type external helical part (1) being processed. The distance between the centers of the shapes of adjacent annular grinding edges (202) in the direction of the axis (101) of the part is equal to the helical groove distance of the shaft-type external helical part being processed. The guide wheel (3) has annular grooves or annular ridges (302) with no helix angle. The annular grooves or annular ridges (302) match the concave and convex morphology of the helical structure normal of the machined shaft-type external helical part (1). The distance between adjacent annular grooves or annular ridges in the direction of the part's axis (101) is equal to or an integer multiple of the helical groove distance of the machined shaft-type external helical part.

4. The device according to claim 1, characterized in that: The part's axis (101) is arranged horizontally; the first vertical plane (P) is a vertical plane, and the adjustable tilt angle of the grinding wheel axis (201) within the first vertical plane (P) is ±30° with respect to the horizontal plane; The second vertical plane (Q) is a vertical plane, and the tilt angle of the guide wheel axis (301) in the second vertical plane is adjustable to be ±30° with the horizontal plane.

5. The device according to claim 1, characterized in that: The support device (4) is equipped with a support structure that contacts the radial lower side of the shaft-type external helical part (1), so that the part (1) is close to the guide wheel (3). The support structure is an inclined surface (401) or a curved surface (402).

6. The device according to claim 1, characterized in that: The trimmer (5) is disposed directly or indirectly on the first member (8) or / and directly or indirectly on the second slide (14).

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