Integrated Cutting and Honing Tools

Abstract

The integrated turning and honing tool holder includes a body defining a feed direction, a cutting direction perpendicular to the feed direction, and a depth direction perpendicular to both the feed direction and the cutting direction. The cutting portion is fixed relative to a top end of the body. The cutting portion and the honing portion are stacked in the cutting direction. The honing portion is hidden within the body during the cutting process but is activated and extended outside the body during the honing process. A relative position between the cutting portion and the honing portion is established so that the honing process can be performed after the cutting process.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to an earlier, co-pending U.S. Provisional Patent Application No. 63 / 399,904, filed August 22, 2022, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Precision machining of mechanical components, such as bearings, is typically achieved using CNC machine tools. Rough turning and finish turning are two primary processes involved in the machining process, removing unwanted material to achieve the desired dimensions and surface finish of the workpiece. However, most precision components require an extremely smooth surface, and the finish-turned surface is often insufficient to achieve the desired surface finish. Therefore, precision components require additional superfinishing on specialized machines known as honing machines. Honing is a finishing process that uses bonded cutting grains to improve the size, dimensional accuracy, and surface finish of a workpiece while maintaining constant surface contact with the tool. In most cases, honing is performed after precision machining, such as grinding or turning. Honing is achieved by applying an abrasive wheel of appropriate grit size and grade to the workpiece surface. Therefore, the additional honing process inevitably increases cycle time, thereby reducing production volume and increasing production costs. Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention relates to a single combination turning and honing tool that allows a CNC lathe to perform the honing process during or after turning without the need for additional tools or tool changes. [Means for solving the problem]

[0004] In one aspect, the present invention provides an integrated tool holder for turning and honing for a CNC machine tool. The body of the integrated turning and honing tool holder defines a feed direction, a cutting direction perpendicular to the feed direction, and a depth direction perpendicular to both the feed direction and the cutting direction. The cutting portion is fixed relative to the top end of the body. The cutting portion specifies a chip direction. The honing portion is positioned directly below the cutting portion, and the honing direction is parallel or angled relative to the chip direction. The cutting portion and honing portion are stacked in the cutting direction. The honing portion is hidden within the body during the cutting process but is activated and extended outside the body during the honing process. A relative position between the cutting portion and the honing portion is established so that the honing process can be performed after the cutting process. The present invention adds honing capability to a tool holder for turning powered by a pressurized refrigerant, thereby enabling a CNC lathe to perform turning and honing without the need for additional tools or devices. By providing a honing function in the tool holder, the surface finish of the finish turned component can be widely improved on the CNC lathe without the need for further machining on a honing machine.

[0005] In a second aspect, the present invention provides a method for precision machining, specifically, a method for integrated turning and honing machining. The workpiece is honed simultaneously using a honing section positioned below an upper cutting section, or honed after the cutting process performed by the cutting section. The honing process is powered by a pressurized coolant, meaning that no additional power source, such as a living tool, is required. In addition, the honing force can be adjusted by adjusting the coolant pressure from the supply. Suitable honing stones are available in various hardnesses and grit sizes based on superfinishing requirements. The workpiece may be honed during feed-in or feed-out.

[0006] The present invention offers a series of advantages. The first benefit is the possibility of adding honing capabilities to a conventional CNC lathe and tool holder without the need for additional tooling, thereby enhancing the surface finish of the machined surface. Second, the honing system can be hidden within the tool holder when not in use so as not to interfere with the turning process. Third, the tool holder does not require a separate power system. A pressurized coolant drives the honing operation. Fourth, the applied honing abrasive can be replaced, and the honing pressure can be adjusted by changing the coolant pressure. Other aspects are described in more detail in the following drawings. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of an integrated tool holder for turning and honing according to one embodiment of the present disclosure, with the honing portion shown extended; [Figure 1A] FIG. 2 is a cross-sectional view of the integrated tool holder of FIG. 1. [Figure 2] FIG. 2 is an exploded view of the integrated turning and honing tool holder of FIG. 1. [Figure 3] FIG. 3 is a cross-sectional view of the integrated tool holder of FIGS. 1 and 2 showing the honing portion retracted. [Figure 4] FIG. 1 is a perspective view of an exemplary workpiece turning operation on a lathe. [Figure 5] FIG. 1 is a plan view of an integrated tool holder in position for honing a cylindrical side surface of a workpiece mounted on a lathe. [Figure 6] FIG. 1 is a plan view of an integrated tool holder positioned for honing an end surface of a workpiece mounted on a lathe. [Figure 7] FIG. 10 is a perspective view of an integrated tool holder for turning and honing according to another embodiment of the present disclosure, wherein the cutting portion and the honing portion have respective tip angles that are offset from one another; DETAILED DESCRIPTION OF THE INVENTION

[0008] Before any embodiment of the present invention is described in detail, it is to be understood that the invention is not limited in its application to the structural details and the arrangements of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or carried out in many different ways.

[0009] CNC lathes are commonly used to turn precision components that require a fine surface finish. As known in the art, turning is a cutting operation whereby a workpiece 100 is rotated on a lathe about a central axis A while a cutting tool is brought into contact with the surface of the workpiece 100, as shown in FIG. 4 . Turning can be classified as rough turning or finish turning. Typically, finish turning is the final turning operation that can be performed on a CNC lathe. However, to meet the required surface finish standards for precision components, in most cases the workpiece must be transferred to a superfinishing machine for a honing process after the finish turning process. This additional honing procedure increases cycle time and production costs. The present invention incorporates honing capabilities into the turning tool holder on a CNC lathe, enabling a typical CNC lathe to perform the superfinishing process. The CNC lathe can perform the superfinishing process immediately after the finish turning process. This eliminates the need for superfinishers in the component finishing process, which greatly reduces manufacturing costs and increases productivity.

[0010] The illustrated embodiment includes a dual-function tool 20 for cutting and honing on a lathe. The tool 20 includes a tool holder or body 8 (e.g., formed as a shank body) that defines a cutting direction C along which the tool 20 faces to engage and penetrate a workpiece 100 during a metalworking cutting (e.g., turning) operation. The cutting direction C is perpendicular to the surface of the rotating workpiece 100 and is diametrically opposed to the direction of workpiece rotation at the point of contact. The tool 20 further defines a feed direction F that is perpendicular to the cutting direction C (and parallel to the axis A of the rotating workpiece 100 on the lathe). The tool 20 may typically be fixed in the cutting direction C, but movement of the tool 20 in the feed direction F results in an axial length of the cutting operation along the surface of the rotating workpiece 100. A depth direction D of the tool 20 is perpendicular to both the feed direction F and the cutting direction C. Movement of the tool 20 in the depth direction D adjusts the amount of overlap between the cutting tip of the tool 20 and the workpiece 100, varying the depth of cut and chip load. In other words, movement of the tool 20 in the depth direction moves the cutting tip toward or away from the central axis A of the rotating workpiece 100 on the lathe. The exception is end turning (FIG. 6), in which the tool 20 may be oriented to act on an axial end surface of the workpiece 100. In that case, the depth direction D is parallel to the workpiece / lathe rotation axis A, and the feed of the tool 20 is toward or away from axis A.

[0011] The tool 20, particularly the body 8, is composed of two functional sections adjacent to the distal or tip end. The cutting portion 24 is disposed on the top side of the body 8 (i.e., forward in the cutting direction C). The honing portion 28 is located below the cutting portion 24 (i.e., behind the cutting portion 24 in the cutting direction C). Thus, the cutting portion 24 and the honing portion 28 are spaced apart and stacked in the cutting direction C. The relative positions between the cutting portion 24 and the honing portion 28 are determined to complete a honing process subsequent to a cutting process. The honing portion 28 can be selectively stored or hidden within the body 8 during cutting by the cutting portion 24 ( FIG. 3 ). The honing operation by the honing portion 28 can be performed during cutting by the cutting portion 24 (simultaneous cutting and honing) or after cutting by the cutting portion 24 (sequential cutting and honing). During honing, the honing insert 3 (ie, grinding stone) of the honing portion 28 may extend from the body 8, and the amount of extension may be adjustable in some configurations.

[0012] FIG. 1A is a cross-sectional view of an exemplary tool 20 with the honing portion 28 activated or deployed, and FIG. 2 is an exploded view. FIG. 3 is a cross-section similar to FIG. 1A but with the honing portion 28 retracted. The tool 20 includes a shank body 8, a cutting insert 4 of the cutting portion 24, an insert shim 9, a piston 5, a spring 11, a honing stone 3 of the honing portion 28, and various fasteners (e.g., set screws 1, 2, 6, and 12). The conventional turning function is performed by the cutting portion 24, which is achieved by the turning insert 4, shim 9, and screw 10 for securing the cutting portion 24 together with the body 8. The incorporated honing feature is achieved by the piston 5, which holds the honing stone 3. Set screws 1, 2, and 6 are for blocking and directing the flow of coolant from a coolant source 40 (e.g., receiving pressurized coolant through opening 21 with set screw 1 removed but the other set screws 2 and 6 in place to prevent coolant leakage). Set screw 12 is for locking honing stone 3. Thus, the present invention has multiple modes of operation. One mode of operation is simply a turning operation using only cutting portion 24. However, tool 20 is also capable of a coolant-driven honing mode. As noted, the honing mode can occur simultaneously with or immediately after cutting without changing tools or moving workpiece 100 to a different machine or workstation.

[0013] The cutting insert 4 and shim 9 are assembled into the receiving portion 13 of the body 8 to form the cutting portion and configure the tool 20 for cutting (e.g., turning) a workpiece 100 mounted on a lathe. The honing stone 3 is inserted into the bore opening 14 at the distal end of the piston 5 and locked by a set screw 12 on the side of the piston 5. The assembled piston 5 with the honing stone 3 is inserted into the bore opening 15 with a spring 11 between a step 16 on the piston 5 and the body 8. The piston 5 is thus biased to the retracted position ( FIG. 3 ) by the spring 11 exerting pressure on the body 8 at its shoulder. The inserted honing portion 28, assembled as described above, is then constrained to a limited extension by the insert screw 10 from the cutting portion 24, and the honing portion 28 is locked within the body 8 from the rear side by the set screw 6. Additional set screws 1 and 2 can be inserted to seal off the coolant flow path in the depth direction D and cutting direction C.

[0014] When the insert 4 is engaged with the workpiece 100, the cutting surface can rotate directly toward and engage the honing portion, particularly the tip of the honing stone 3. With this understanding, when in the assembled position as shown in FIG. 1 and the honing portion is activated, the honing stone 3, including a portion of the piston 5, rotates in a honing tip direction T h Extends outward from the body 8 in the honing tip direction T h is the longitudinal axis of the cutting insert 4 or the cutting chip direction T c and parallel to the cutting chip direction T c In other configurations (FIG. 7), the honing stone 3 may be oriented off-axis with the cutting insert 4 such that there is a small angle (e.g., depending on the type of insert seat / type of tool holder) between the two respective chip directions. In one exemplary embodiment, there is a small tool holder clearance angle of approximately 6 degrees.

[0015] Cutting chip direction Tc The honing tip direction T may be oriented at a small angle α (e.g., less than 30 degrees, or less than 15 degrees) away from the depth direction D and toward the feed direction F. This is more clearly shown in the top view of FIG. 5, which includes the workpiece 100. h may lie in the plane defined by the feed direction F and the depth direction D so as to be also perpendicular to the cutting direction C. Although they do not coincide with each other due to the physical spacing between them, the chip direction T of the honing stone 3 h and the chip direction T of the cutting insert 4 c can lie in a single reference plane parallel to the cutting direction C (Figure 5 is a view directly along the cutting direction C, with two chip directions T h and T c are overlapping each other). In this configuration, the honing operation can be performed simultaneously with the cutting process. In other words, a surface portion of the workpiece 100 is cut to size and honed in the same pass of the workpiece 100 along the tool 20 while the workpiece 100 continues to move on the lathe. The single tool 20 remains in the working position and does not need to be removed or reconfigured between cutting and honing. At the same time, two adjacent portions of the workpiece are engaged by the insert 4 and the honing stone 3, respectively.

[0016] The integrated cutting and honing tool 20 can operate as follows. · Turning No pressurized refrigerant is drawn from the source 40, so the honing portion 28 remains hidden inside the body 8, biased by the spring 11. In some configurations, the honing stone 3 extends from the body 8 but below the insert 4. Only the cutting portion 24 is active, and the workpiece 100 is contacted only by the insert 4. · HoningPressurized refrigerant from source 40 is activated and flows through opening 21 into a passage in body 8, pushing against the back or inner end face of piston 5. The spring is compressed, forcing the piston outward from body 8 and applying a hone force to the surface of workpiece 100. · After honing , the pressurized refrigerant from source 40 is turned off, then spring 11 is decompressed and honing portion 28 is retracted.

[0017] The honing force is calculated by the following formula: F ホーニング =F 冷媒 ×cosα where α is the honing tip direction T when honing the (cylindrical side) surface of the workpiece 100 perpendicular to the depth direction D (and parallel to the lathe axis A) as shown in FIGS. 4 and 5. h and the depth direction D. However, the tool 20 may be oriented on a lathe to hone an end surface of the workpiece 100 perpendicular to the lathe axis A as shown in FIG. 6. In such a configuration, the angle α in the above expression is the angle between the honing tip direction T h α, which is defined as the angle between x Replaced by F 冷媒 is the force of the refrigerant, which is F 冷媒 =P 冷媒 ×A ピストン where P 冷媒 is the pressure of the refrigerant, and P ピストン is the area of ​​the rear end surface 17 of the piston 5.

[0018] 7 illustrates a tool 20' that may conform to the elements and features described above except as specifically noted below. Tool 20 includes a honing stone 3 and a cutting insert 4, the two of which have different or offset tip angles T h , T cIn other words, the honing stone 3 may be oriented off-axis with the cutting insert 4 such that there is a small angle between the two respective chip directions.

[0019] Thus, the tool 20 as shown and described incorporates a honing function into the tool holder that supports the cutting insert 4. This differs from conventionally used turning tool holders and specialized honing tool holders. Additionally, the honing process relies on coolant pressure maintained inside the tool holder body 8 to maintain the honing force. The tool 20 may be used to cut a wide range of materials, including hardened and unhardened, and for numerous products, including, but not limited to, bearing rollers, without departing from the spirit of the present invention. Those skilled in the art will recognize other possible variations and / or embodiments, which are considered to be within the scope of the present invention.

Claims

1. a body defining a feed direction, a cutting direction perpendicular to the feed direction, and a depth direction perpendicular to the feed direction and the cutting direction; a cutting portion fixed relative to the body on a top side of the body facing the cutting direction; a honing portion supported by the body at a position rearward of the cutting portion in the cutting direction so as to be stacked with the cutting portion in the cutting direction; and Equipped with The metalworking CNC tool, wherein the honing portion is movable along the body to various positions in the depth direction.

2. The metalworking CNC tool of claim 1 , wherein the cutting portion and the honing portion are configured to adjust a relative position between the cutting portion and a second portion.

3. 2. The metalworking CNC tool of claim 1, wherein the cutting portion extends along a cutting tip direction and the honing portion extends along a honing tip direction parallel to the cutting tip direction.

4. 10. The metalworking CNC tool of claim 1, wherein the cutting portion extends along a cutting tip direction and the honing portion extends along a honing tip direction that is offset from the cutting tip direction by a non-zero angle.

5. The metalworking CNC tool of claim 1 , wherein an adjustment device is configured to adjust the relative position between the cutting portion and the honing portion.

6. The metalworking CNC tool of claim 1 , wherein the honing portion is configured to be completely contained within the body.

7. 10. The metalworking CNC tool of claim 1, further comprising a coolant passage within the body and configured to contain a quantity of coolant that, when pressurized, provides an extensional force that urges the honing portion to extend from the body.

8. The metalworking CNC tool of claim 1 , wherein the range of movement of the honing portion is limited by a fastener.

9. The metalworking CNC tool of claim 1 , wherein the cutting portion is formed as an insert that is removably coupled within a receptacle formed in the top side of the body.

10. 10. The metalworking CNC tool of claim 1, wherein the honing portion includes a movable piston having a distal end opening and a honing stone inserted into the distal end opening and locked to the piston by a fastener.

11. The metalworking CNC tool of claim 1 , wherein the coolant enters the tool holder from a bottom side of the body.

12. 1. A method for CNC metal machining on a rotating workpiece, comprising: providing a machining tool having a shank body defining a feed direction, a cutting direction, and a depth direction perpendicular to the feed direction and the cutting direction, wherein a cutting portion is secured to the body toward a top side of the body and a honing portion is supported by the body toward a bottom side of the body; cutting the workpiece with the cutting portion of the machining tool to leave a cut surface roughness on a surface of the workpiece; honing the workpiece with the honing portion of the machining tool to reduce the surface roughness compared to the cut surface roughness; A method comprising:

13. The method of claim 12, wherein the cutting and honing are performed simultaneously with the cutting portion and the honing portion stacked in the cutting direction in a leading-trailing arrangement with respect to the cutting direction.

14. 14. The method of claim 13, further comprising adjusting the depth of the honing portion relative to the cutting portion to achieve a desired chip load ratio between the cutting portion and the honing portion.

15. The method of claim 12 wherein the honing occurs after the cutting is completed.

16. 13. The method of claim 12, further comprising adjusting the extension of the tip of the honing portion from the body by adjusting fluid pressure on a piston inside the body.

17. 13. The method of claim 12, further comprising biasing the honing portion with a first spring, removing and replacing the first spring with a second spring, and biasing the honing portion with the second spring to provide a different honing force than the first spring.

18. 13. The method of claim 12, further comprising adjusting honing performance by alternating different abrasive stone materials in the honing section.

19. 13. The method of claim 12, further comprising automatically compensating for wear of the honing portion by a continuous push of a fluid force inside the body.

20. The method of claim 12 , further comprising adjusting the honing force applied to the workpiece by the honing portion by adjusting a fluid pressure of a coolant within the body.

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