Reverse fine boring cutter for numerically controlled lathe

Abstract

The utility model relates to a reverse fine boring cutter for a numerically controlled lathe, which comprises a cutter bar, a main positioning surface arranged at one end of the cutter bar and parallel to the axis of the cutter bar; the blade is attached to the main positioning face, the tool nose is located outside the main positioning face, the blade is fixed to the tool bar through a bolt, and the axis of the bolt is perpendicular to the main positioning face; the positioning structure comprises a positioning protrusion arranged on the main positioning face and a main positioning groove formed in the blade, and the positioning protrusion is embedded in the main positioning groove and limits the blade to rotate around the axis of the bolt. The blade is fixed on the main positioning surface through the bolt, so that the fixed point of the blade is closer to the tool nose, the influence on the rigidity of the blade due to overlarge suspended length is avoided, and the good rigidity of the tool nose is ensured; the positioning protrusions are arranged to be matched with the main positioning grooves in the blades to achieve positioning of the blades on the main positioning faces, the blades are convenient to assemble, meanwhile, the positioning protrusions and the main positioning grooves are matched to bear cutting force of the blades during reverse fine boring, and good positioning precision and transposition precision of the blades are guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical manufacturing process equipment, in particular to a reverse fine boring cutter for a numerically controlled lathe. Background Art

[0002] At present, when processing thin-walled disc parts (such as rear oil seal seat ring) on ​​CNC lathes, in order to ensure the verticality of the end faces on both sides of the rear oil seal seat ring to the bearing hole, after the rear oil seal seat ring is installed and clamped once, a positive finishing boring tool is used to finish turning the outer end face, and then a reverse finishing boring tool is used to reverse bore the bearing hole and reverse finish turn the inner end face.

[0003] Traditionally, reverse finishing boring is done by using a grooving cutter to pass through a hole (smaller than the bearing hole diameter) and utilizing the slight elastic deformation of the grooving cutter to perform reverse finishing boring. Since the blade used in the grooving cutter is a special-shaped grooving blade, the blade is expensive and is fastened with a pressure plate. The blade extends a long distance out of the tool body, resulting in poor overall rigidity of the tool. During reverse finishing boring, the cutting force has the risk of causing the blade to separate from the positioning surface, resulting in dimensional instability and high tool consumption during processing. Utility Model Content

[0004] Based on the above description, the utility model provides a reverse finishing boring tool for a CNC lathe to solve the problem in the related technology that the blade is fastened by a pressure plate, the blade extends out of the tool body for a long time, resulting in poor overall rigidity of the tool, and the cutting force during reverse finishing boring has the risk of causing the blade to separate from the positioning surface, resulting in dimensional instability and high tool consumption during processing.

[0005] The technical solution of the utility model to solve the above technical problems is as follows:

[0006] The present application provides a reverse fine boring tool for a CNC lathe, and the technical solution adopted is as follows:

[0007] A reverse fine boring tool for a CNC lathe, comprising:

[0008] A knife bar, one end of which is provided with a main positioning surface, wherein the main positioning surface is parallel to the axis of the knife bar;

[0009] A blade, which is in contact with the main positioning surface and has a blade tip outside the main positioning surface, the blade being fixed to the blade rod by bolts, with the bolt axis being perpendicular to the main positioning surface;

[0010] The positioning structure comprises a positioning protrusion arranged on the main positioning surface and a main positioning groove arranged on the blade. The positioning protrusion is embedded in the main positioning groove and limits the blade from rotating around the bolt axis.

[0011] Preferably, the positioning protrusion is in a strip shape and extends along a first straight line direction parallel to the main positioning surface.

[0012] Preferably, the cross-section of the positioning protrusion is an isosceles trapezoid, and the longer base of the isosceles trapezoid coincides with the main positioning surface.

[0013] Preferably, one end of the tool shank where the main positioning surface is provided is provided with a side positioning surface. The side positioning surface is perpendicular to and intersects the main positioning surface. A side positioning groove is formed on the side positioning surface. One end of the blade away from the cutting edge is embedded in the side positioning groove and abuts against the inner wall of the side positioning groove. The side positioning groove restricts the blade from rotating around the axis of the bolt.

[0014] Preferably, the side positioning surface is parallel to the first straight-line direction.

[0015] Preferably, a through hole for the bolt to pass through is formed on the blade, and a threaded hole for the threaded assembly of the bolt is formed on the main positioning surface.

[0016] Preferably, when the bolt is not installed, the blade fits against the main positioning surface. When the blade is embedded in the side positioning groove and the positioning protrusion is embedded in the main positioning groove, the axis of the through hole is parallel to but does not coincide with the axis of the threaded hole, and is adapted to make the blade and the inner wall of the side positioning groove be extruded and deformed until the axis of the through hole coincides with the axis of the threaded hole during the process of the bolt passing through the through hole and being assembled in the threaded hole.

[0017] Compared with the prior art, the technical solution of the present application has the following beneficial technical effects:

[0018] 1. In the present application, the main positioning surface is provided for positioning the blade, and the blade is fixed on the main positioning surface by a bolt. The bolt fixing method can make the fixing point of the blade closer to the cutting edge, avoid the excessive overhang of the blade and affect its rigidity, and ensure that the cutting edge has good rigidity; the main positioning surface plays a role in positioning and supporting the blade. At the same time, a positioning structure is set up, and the cooperation between the positioning protrusion on the main positioning surface and the main positioning groove on the blade is used to realize the positioning of the blade on the main positioning surface, which is convenient for the assembly of the blade. At the same time, the cooperation between the positioning protrusion and the main positioning groove bears the cutting force of the blade during reverse fine boring, ensuring good positioning accuracy and indexing accuracy of the blade;

[0019] 2. By providing a side positioning surface and a side positioning groove, when installing the blade, after the main positioning groove on the blade cooperates with the positioning protrusion on the main positioning surface, the end of the blade away from the tool tip is inserted into the side positioning groove, further improving the positioning accuracy of the blade. Further, the inner wall of the side positioning groove is used to bear the cutting force of the blade, ensuring good positioning accuracy during the cutting process of the blade. When the blade is positioned and the bolt is not installed, the axis of the through hole on the blade does not coincide with the axis of the threaded hole on the main positioning surface. During the process of the bolt passing through the through hole and being assembled into the threaded hole, the blade and the inner wall of the side positioning groove are extruded and deformed until the axis of the through hole coincides with the axis of the threaded hole, so that the blade is tightly pressed against the inner wall of the side positioning groove after installation, further ensuring the positioning rigidity and positioning accuracy of the blade. Description of the Drawings

[0020] Figure 1 is a schematic structural diagram of a reverse finish boring tool for a numerically controlled lathe provided by an embodiment of the present invention;

[0021] Figure 2 is an exploded view of a reverse finish boring tool for a numerically controlled lathe provided by an embodiment of the present invention;

[0022] Figure 3 is a schematic diagram of the cooperation between a reverse finish boring tool for a numerically controlled lathe provided by an embodiment of the present invention and a to-be-machined rear oil seal seat ring.

[0023] In the drawings, the list of components represented by each reference numeral is as follows:

[0024] 1. Tool shank; 11. Main positioning surface; 12. Positioning protrusion; 13. Side positioning surface; 14. Side positioning groove; 15. Threaded hole; 2. Blade; 21. Main positioning groove; 22. Through hole; 3. Bolt. Detailed Embodiments

[0025] To facilitate the understanding of this application, the following will describe this application more comprehensively with reference to the relevant drawings. Embodiments of this application are given in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of this application more thorough and comprehensive.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the specification of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0027] It will be appreciated that spatial relationship terms such as "under", "below", "lower", "beneath", "above", "upper", etc. can be used herein to describe the relationship of one element or feature shown in the figure with other elements or features. It should be understood that, in addition to the orientations shown in the figure, spatial relationship terms also include different orientations of the device during use and operation. For example, if the device in the attached drawing is flipped, an element or feature described as "under other elements" or "beneath it" or "under it" will be oriented "above" other elements or features. Therefore, the exemplary terms "under" and "beneath" can include both upper and lower orientations. In addition, the device can also include additional orientations (such as rotating 90 degrees or other orientations), and the spatial descriptors used herein are accordingly interpreted.

[0028] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediate element. In the following embodiments, "connection", if there is a transfer of electrical signals or data between the connected circuits, modules, units, etc., should be understood as "electrical connection", "communication connection", etc.

[0029] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprise / include" or "have", etc. specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0030] Referring to Figures 1-3 As shown, an embodiment of the present application provides a reverse finish boring tool for a numerically controlled lathe, which includes a tool shank 1, a cutting blade 2 and a bolt 3. One end of the tool shank 1 is provided with a main positioning surface 11, and the main positioning surface 11 is parallel to the axis of the tool shank 1. The cutting blade 2 fits against the main positioning surface 11 and the cutting edge is located outside the main positioning surface 11. The cutting blade 2 is fixed to the tool shank 1 by a bolt 3, and the axis of the bolt 3 is perpendicular to the main positioning surface 11.

[0031] Referring to Figures 1-2 As shown, specifically, the tool shank 1 is cylindrical and one side is flattened so that it can be fastened when the tool shank 1 is installed on the turret of the numerically controlled lathe. A threaded hole 15 for assembling the bolt 3 is provided on the main positioning surface 11, and a through hole 22 for the bolt 3 to pass through is provided on the cutting blade 2. After the cutting blade 2 fits against the main positioning surface 11, the bolt 3 passes through the cutting blade 2 and is threadedly assembled into the threaded hole 15 of the bolt 3 to fix the cutting blade 2 on the tool shank 1. Specifically, the through hole 22 on the cutting blade 2 includes a straight hole section and a tapered counterbore section, and the tapered counterbore section is adapted to the head of the bolt 3 so that the bolt 3 does not protrude from the surface of the cutting blade 2 when the cutting blade 2 is fixed.

[0032] Referring to Figures 1-2 As shown, further, a positioning structure is provided between the blade 2 and the main positioning surface 11 to position the blade 2. The positioning structure includes a positioning protrusion 12 provided on the main positioning surface 11 and a main positioning groove 21 provided on the blade 2. The positioning protrusion 12 is embedded in the main positioning groove 21 and restricts the blade 2 from rotating around the axis of the bolt 3. Specifically, the main positioning groove 21 is opened on the side surface of the blade 2 that fits the main positioning surface 11. The main positioning groove 21 is adapted in shape and position corresponding to the positioning protrusion 12. When the blade 2 fits the main positioning surface 11 and the positioning protrusion 12 is embedded in the main positioning groove 21, the blade 2 can be fixed by the bolt 3, and the rotation of the blade 2 around the axis of the bolt 3 is restricted by the positioning protrusion 12 being embedded in the main positioning groove 21. The setting of the positioning structure can, on the one hand, position the blade 2, improve the assembly accuracy of the blade 2, and improve the assembly efficiency. At the same time, the positioning protrusion 12 and the main positioning groove 21 cooperate to bear the cutting force of the blade 2 during reverse fine boring, which can ensure good positioning accuracy and indexing accuracy of the blade 2 and ensure the cutting accuracy.

[0033] Referring to Figures 1-2 As shown, further, to improve the strength of the positioning structure, the positioning protrusion 12 is provided as a strip and extends along a first linear direction parallel to the main positioning surface 11. The positioning protrusion 12 is integrally formed with the tool shank 1, so that the positioning protrusion 12 has a higher strength in the direction parallel to the main positioning surface 11 to improve the support strength of the tool. Specifically, the positioning protrusion 12 is provided with an isosceles trapezoidal cross-section, and the longer base of the isosceles trapezoid coincides with the main positioning surface 11. Correspondingly, the cross-section of the main positioning groove 21 is also formed as an isosceles trapezoid. When the positioning protrusion 12 is embedded in the main positioning groove 21, the outer wall fits the inner wall of the main positioning groove 21.

[0034] Referring to Figures 1-2As shown in the figure, further, one end of the tool shank 1 where the main positioning surface 11 is provided is provided with a side positioning surface 13. The side positioning surface 13 is perpendicular to and intersects the main positioning surface 11. A side positioning groove 14 is formed on the side positioning surface 13. One end of the blade 2 away from the cutting edge is embedded in the side positioning groove 14 and abuts against the inner wall of the side positioning groove 14. The side positioning groove 14 restricts the blade 2 from rotating around the axis of the bolt 3. Specifically, the side positioning surface 13 is set to be parallel to the extending direction of the positioning projection 12. The side positioning surface 13 and the main positioning surface 11 form a tool groove for installing the blade 2, so as to facilitate the installation of the blade 2 on the tool shank 1. By providing the side positioning groove 14 on the side positioning surface 13 to cooperate with the blade 2, when installing the blade 2, the positioning projection 12 is embedded in the main positioning groove 21 and one end of the blade 2 away from the cutting edge is embedded in the side positioning groove 14 to complete the positioning of the blade 2. At this time, the position of the through hole 22 on the blade 2 corresponds to the position of the threaded hole 15 on the main positioning surface 11, so as to fix the blade 2 through the bolt 3. After the blade 2 is fixed, during the cutting process, the cooperation between the positioning projection 12 and the main positioning groove 21, and the cooperation between the side positioning groove 14 and the blade 2 bear the cutting force of the blade 2, so as to ensure that the blade 2 maintains good positioning accuracy during the cutting process to ensure the cutting accuracy.

[0035] Refer to Figures 1-2 As shown in the figure, further, when the bolt 3 is not installed, the blade 2 fits against the main positioning surface 11. When the blade 2 is embedded in the side positioning groove 14 and the positioning projection 12 is embedded in the main positioning groove 21, the axis of the through hole 22 is parallel to but does not coincide with the axis of the threaded hole 15, and is adapted to make the blade 2 and the inner wall of the side positioning groove 14 be extruded and deformed until the axis of the through hole 22 coincides with the axis of the threaded hole 15 during the process of the bolt 3 passing through the through hole 22 and being assembled in the threaded hole 15. Specifically, when installing the blade 2, when the positioning projection 12 is embedded in the main positioning groove 21 and one end of the blade 2 away from the cutting edge is embedded in the side positioning groove 14, the axis of the through hole 22 on the blade 2 and the axis of the threaded hole 15 on the tool shank 1 are spaced 0.08 - 0.12 mm apart, that is, there is a very small offset between the axis of the through hole 22 and the axis of the threaded hole 15, so that this offset does not affect the assembly of the bolt 3. And during the assembly process of the bolt 3, the blade 2 is extruded and deformed with the inner wall of the side positioning groove 14 by the bolt 3 to compensate for this offset. Thus, after the bolt 3 is completely assembled in the bolt hole 15, the blade 2 abuts tightly against the inner wall of the side positioning groove 14, and the positioning projection 12 abuts tightly against the inner wall of the main positioning groove 21, so as to further ensure the positioning rigidity and positioning accuracy of the blade 2, avoid the blade 2 from shifting during the cutting process, and ensure the cutting accuracy.

[0036] In this embodiment, the blade 2 is a standard blade 2 made of cemented carbide. A chip-breaking groove is provided on the rake face of the blade 2, and a chip-containing groove is arranged at a position corresponding to the chip-breaking groove on the main positioning surface 11. The surface of the blade 2 is provided with a wear-resistant coating. Since a main positioning groove 21 is formed on the blade 2, to ensure the strength of the blade 2, the thickness of the blade 2 needs to be thickened. During design, after the blade 2 is installed in the tool groove, the cutting edge faces the end of the tool bar 1 away from the blade 2. The specific parameters of each structure are designed according to the actual situation, and it is ensured that there is no interference between the tool and the part to be machined during the cutting process.

[0037] This embodiment has the following advantages:

[0038] 1. A main positioning groove 21 is formed on the blade 2 to cooperate with the positioning projection 12 on the tool bar 1 to position the blade 2 and bear the cutting force during reverse fine boring, ensuring good positioning accuracy and indexing accuracy of the blade 2.

[0039] 2. The blade 2 has a large thickness and good tool strength. The blade 2 is integrally installed on the boring bar 1 through a large bottom surface and fastened with bolts 3. The installation operation of the tool is simple and convenient. The clamping point is close to the tip of the tool, avoiding the defect of poor rigidity caused by too long overhang in the clamping of the grooving tool pressing plate, and having good tool rigidity.

[0040] 4. The structure is simple and compact. There are no obstacles such as pressing plates of traditional reverse fine boring tools above the blade 2, which is convenient for the discharge of iron chips during the machining of bearing holes and avoids the iron chips from scratching the machined inner hole.

[0041] 5. The single-piece consumption of the tool is low. The price of the standard blade 2 is lower than that of the grooving blade 2 used in traditional reverse fine boring tools, and the cost of a single-piece blade 2 can be greatly reduced.

[0042] 6. The reverse fine boring tool can be applied to the machining process of reverse boring internal holes of various sizes on a numerically controlled lathe, has good overall strength and rigidity of the tool, and the tool has a high cost performance.

[0043] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A reverse fine boring tool for a CNC lathe, characterized in that: include: A knife bar (1) having a main positioning surface (11) at one end, wherein the main positioning surface (11) is parallel to the axis of the knife bar (1); A blade (2) which is in contact with the main positioning surface (11) and has a blade tip located outside the main positioning surface (11); the blade (2) is fixed to the blade rod (1) by a bolt (3), and the axis of the bolt (3) is perpendicular to the main positioning surface (11); The positioning structure comprises a positioning protrusion (12) provided on the main positioning surface (11) and a main positioning groove (21) provided on the blade (2); the positioning protrusion (12) is embedded in the main positioning groove (21) and limits the blade (2) from rotating around the axis of the bolt (3).

2. The reverse fine boring tool for a CNC lathe according to claim 1, characterized in that: The positioning protrusion (12) is strip-shaped and extends along a first straight line direction parallel to the main positioning surface (11).

3. The reverse fine boring tool for a CNC lathe according to claim 2, characterized in that: The cross section of the positioning protrusion (12) is an isosceles trapezoid, and the longer bottom side of the isosceles trapezoid coincides with the main positioning surface (11).

4. The reverse fine boring tool for a CNC lathe according to claim 2, characterized in that: The blade rod (1) is provided with a side positioning surface (13) at one end of the main positioning surface (11), the side positioning surface (13) is perpendicular to and intersects with the main positioning surface (11), and the side positioning surface (13) is provided with a side positioning groove (14), and the end of the blade (2) away from the blade tip is embedded in the side positioning groove (14) and abuts against the inner wall of the side positioning groove (14), and the side positioning groove (14) limits the blade (2) from rotating around the axis of the bolt (3).

5. The reverse fine boring tool for a CNC lathe according to claim 4, characterized in that: The side positioning surface (13) is parallel to the first straight line direction.

6. The reverse fine boring tool for a CNC lathe according to claim 4, characterized in that: The blade (2) is provided with a through hole (22) for the bolt (3) to pass through, and the main positioning surface (11) is provided with a threaded hole (15) for the bolt (3) to be threadedly assembled.

7. The reverse fine boring tool for a CNC lathe according to claim 6, characterized in that: When the bolt (3) is not installed, the blade (2) fits the main positioning surface (11), and when the blade (2) is embedded in the side positioning groove (14) and the positioning protrusion (12) is embedded in the main positioning groove (21), the axis of the through hole (22) is parallel to the axis of the threaded hole (15) and does not overlap, and is suitable for causing the blade (2) and the inner wall of the side positioning groove (14) to be squeezed and deformed until the axis of the through hole (22) overlaps with the axis of the threaded hole (15) during the process of the bolt (3) passing through the through hole (22) and being assembled in the threaded hole (15).

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