Hole machining tool
By designing a multi-point contact hole wall support key and coolant lubrication, the problems of hole shrinkage and friction damage in hole machining by reamers were solved, achieving high-precision and smooth hole machining results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI NAGOYA PRECISION TOOLS CO LTD
- Filing Date
- 2025-05-12
- Publication Date
- 2026-04-10
AI Technical Summary
Existing reamers are prone to defects such as shrinkage, taper, roundness, and chatter marks in hole machining, which cannot meet the requirements of precision machining.
Design a hole machining tool that employs a multi-point (radial) contact hole wall support key structure to reduce surface contact friction and achieve extreme pressure lubrication through coolant to avoid shrinkage and friction damage.
It improves the roundness and cylindricity of the holes, reduces oscillation marks and frictional heat generation, and achieves higher surface quality and precision.
Smart Images
Figure CN224101980U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a material forming processing tool, especially a cutter for machining to implement reaming hole machining. BACKGROUND
[0002] Reaming tools are a kind of tools for precision machining of holes, among which reamers are the most common. The latter is a kind of cutter that removes the surface layer material of the machined hole by rotary cutting to perform hole expansion or hole repair, so as to improve the machining accuracy of the hole and reduce the surface roughness. It includes a working part and a handle part, and the working part plays the functions of cutting and calibration, that is, the reaming is realized by the cutting and calibration of the blade part and the calibration part in sequence. It usually has one or more cutting edges, such as straight line or spiral shape.
[0003] The outer diameter specification of the reaming tool is required to be strict to ensure the need for precision machining of the hole. In order to make the outer diameter specification of the reaming tool adapt to the precision machining of the hole, the blade on the tool is completed by external grinding process. For example, the outer diameter of the calibration part of the reamer is equal to the sum of the target hole diameter and the tolerance of the reamed hole. That is to say, the actual specification of the calibration part of the reamer is that the diameter of the blade on it is the sum of the target hole diameter and the tolerance of the reamed hole, which is ground on the external grinder, and the blade on it is a part of the circular arc surface with the diameter of the sum of the target hole diameter and the tolerance of the reamed hole.
[0004] Common reamers are prone to problems such as size and shape errors such as hole shrinkage, taper, roundness, straightness, and machining defects such as vibration marks and burrs during machining, which cannot meet the requirements of precision machining of the hole, resulting in defective products.
[0005] In order to realize higher quality hole machining (i.e. no hole shrinkage, no taper, high roundness, high straightness, no vibration marks, and no burrs), some new reamer structures have been proposed, or new schemes for hole machining process have been proposed. The former, such as improving the angle of the cutting edge of the reamer to achieve higher hole cylindricity, or improving the width of the blade of the calibration part of the reamer to control the degree of hole shrinkage. The latter, such as using a non-cutting blade rolling tool to roll the hole wall after reaming without cutting to obtain high hole wall smoothness and roundness, or using a honing tool to perform micro-grinding on the hole wall after reaming to eliminate vibration marks. CONTENT OF THE UTILITY MODEL
[0006] One object of the utility model is to provide a hole machining cutter, which integrates cutting and reaming to eliminate hole shrinkage and hole deformation during reaming hole machining, and improve the true roundness of the hole.
[0007] Another object of the utility model is to provide a hole machining cutter to eliminate taper hole during reaming machining and improve cylindricity.
[0008] The utility model discloses a further purpose is to provide a hole processing cutter to reduce the radial swing amplitude of cutter in high -speed rotation, eliminate the vibration cutter mark formed in the hole wall in reaming.
[0009] In machining, the so-called material or workpiece is usually the material or semi-finished product for manufacturing parts or components, and is the processing object in the machining process. That is, after machining the workpiece, a product that meets the machining or design requirements is obtained, such as a hole processing cutter and a milling cutter. For a workpiece used for cutter machining, it usually includes an axis, and the axial length is greater than the radial length.
[0010] Precision machining refers to a machining technology with extremely high machining precision and surface quality. For example, in cutter machining, the size, straightness, profile degree, surface roughness, blade tip arc radius, and machining precision are all higher than microns.
[0011] A machining device (or machining center) is a machining device with multiple motion axes. That is, in a right-handed rectangular coordinate system, the X, Y, and Z axes move in a straight line, and the A, B, and C axes rotate around the X, Y, and Z axes, respectively. For example, a numerical control machine tool usually loads various control software to receive and issue various instructions in code form to automatically process the workpiece. For example, the control code formed by the method for forming the drill point of the hole processing cutter can be automatically implemented on the machining device, and a product that meets the machining or design requirements can be obtained.
[0012] A hole processing cutter includes
[0013] A cutting body includes a cutting base and a cutting edge portion, and the cutting edge portion is arranged on the cutting base and at the leading end in the cutting feed direction;
[0014] A hole wall support key is arranged on the cutting base, located behind the cutting edge portion in the cutting feed direction, and rotates synchronously with the base, including a base and a support surface. In the radial direction of the cutting base, the outer edge of the support surface has a contact point with the hole wall, and the contact points of the radial outer edges of the support surface are in contact with the hole wall. All or part of these contact points present a straight line segment arranged in the axial direction of the cutting base.
[0015] From the radial direction of the cutting base, the hole wall support key realizes point contact with the hole wall, rather than surface contact, which not only effectively supports the hole wall, but also maximally reduces the contact and friction with the hole wall.
[0016] In an embodiment, the base is arranged on the cutting base, has a gap with the hole wall formed by machining, and the support surface fills part of the gap.
[0017] In another specific embodiment, the base is arranged on the cutting base, and along the axial direction of the cutting base, the radial gap between the base and the hole wall gradually converges towards the front end of the support surface, so as to avoid the hole wall support key from contacting the hole wall and causing friction when the tool is retracted, and to avoid damage to the machined hole wall.
[0018] In another specific embodiment, the base is arranged on the cutting base, and along the axial direction of the cutting base, the radial gap between the base and the hole wall gradually converges towards the rear end of the support surface, so as to avoid the hole wall support key from contacting the hole wall and causing friction when the tool is retracted, and to avoid damage to the machined hole wall.
[0019] In another specific embodiment, from the radial direction of the cutting base, an arc can be observed on each radial section of the support surface, and each arc has a contact point with the hole wall on the side facing the hole wall. Correspondingly, the contact points form a straight line segment arranged along the axial direction of the cutting base.
[0020] In another specific embodiment, from the radial direction of the cutting base, the support surface forms an arc, and the contact point between the outer edge of the support surface and the hole wall is located at the top of the arc on the side facing the hole wall. The shape of the arc is taken from a part of a geometric figure such as a circle, an ellipse, a parabola, or a hyperbola.
[0021] In another specific embodiment, from the radial direction of the cutting base, an arc can be observed on each radial section of the support surface, and each arc has a contact point with the hole wall on the side facing the hole wall. Correspondingly, the contact points form a straight line segment arranged along the axial direction of the cutting base.
[0022] The number of hole wall support keys is at least 2 more than the number of cutting edge portions.
[0023] In another specific embodiment, the hole machining tool has three hole wall support keys, and each hole wall support key is arranged on the outer periphery of the cutting base and protrudes from the surface of the cutting base. Thus, from the radial direction of the cutting base, the three hole wall support keys achieve three-point contact with the hole wall at different positions, rather than face contact between three arcs of the same diameter and the hole wall of the same diameter. This not only achieves more effective support for the hole wall, but also maximizes the contact and friction with the hole wall.
[0024] In another specific embodiment, the hole machining tool has 5 hole wall support keys, each of which is arranged on the outer periphery of the cutting base and protrudes from the surface of the cutting base. Thus, from the radial direction of the cutting base, the 5 hole wall support keys achieve five-point contact with the hole wall at different positions, rather than five circular arcs of the same diameter in surface contact with the hole wall of the same diameter, which not only achieves more effective support for the hole wall, but also maximally reduces the contact and friction with the hole wall.
[0025] In another specific embodiment, the hole machining tool has 7 or more hole wall support keys, each of which is arranged on the outer periphery of the cutting base and protrudes from the surface of the cutting base.
[0026] In another specific embodiment, along the axial direction of the cutting base, the support surface feed front end is spaced apart from the cutting base feed front end by ≥0.1mm, and in particular 0.7±0.3mm.
[0027] The hole machining tool of the utility model further includes a handle part, which is arranged behind the cutting main body in the feed direction and used for connecting with a rotating machine.
[0028] The hole machining tool of the utility model forms a hole wall in a reaming manner and is suitable for reaming hole machining.
[0029] The hole machining tool of the utility model is used for implementing reaming hole machining, provides multi-point (radial) contact for the hole wall machined by reaming, effectively reduces the friction and heating caused by surface contact and thus avoids the shrinkage phenomenon, and the multi-point contact also maximally retains the liquid film between the blade band and the hole wall to achieve maximum lubrication and obtain the best roughness.
[0030] The hole machining tool of the utility model is used for implementing reaming hole machining, provides multi-point (radial) contact for the hole wall machined by reaming, and also achieves the isolation of the blade band edge and the hole wall, avoids the friction of the sharp edge of the blade band to the hole wall in the machining and tool withdrawal processes, and causes damage. BRIEF DESCRIPTION OF DRAWINGS
[0031] Figure 1 It is a schematic view of an embodiment of the hole machining tool of the utility model;
[0032] Figure 2 It is a schematic view of another embodiment of the radial outer edge of the hole machining tool of the utility model in contact with the hole wall; Figure 1
[0033] Figure 3 It is a schematic view of another embodiment of the radial outer edge of the hole machining tool of the utility model in contact with the hole wall;
[0034] Figure 4 It is a schematic view of another embodiment of the radial outer edge of the hole machining tool of the utility model in contact with the hole wall; Figure 3 It is a schematic view of another embodiment of the radial outer edge of the hole machining tool of the utility model in contact with the hole wall; Detailed Implementation
[0035] The technical solution of this utility model is described in detail below with reference to the accompanying drawings. The embodiments of this utility model are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of the utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model.
[0036] Figure 1 This is a schematic diagram of an embodiment of the hole-machining tool of this utility model. Figure 1 As shown, the cutting tool of this embodiment includes a shank 100 that can be connected to rotating machinery, an axis 200 extending longitudinally along the shank 100, and a cutting body 300. The cutting body 300 includes a cutting base 310 and cutting edges 320. Each cutting edge 320 is arranged on the radial outer edge of the cutting base 310. The number of cutting edges depends on the machining requirements. Several cutting components, such as PCD inserts, are fixed on a groove (not shown) provided on the radial outer edge of the cutting base 310, arranged around the axis 200, and located at the tip (i.e., the end that first contacts the material) in the cutting feed direction (as shown by the arrow in the figure).
[0037] At least one hole wall support key 400 is provided on the cutting base. Preferably, the number of hole wall support keys 400 is at least two integers more than the number of cutting edge portions 320. For example, if there is one cutting edge portion 320, then there are three hole wall support keys 400. If there are two cutting edge portions 320, then there are four hole wall support keys 400. If there are three cutting edge portions 320, then there are five hole wall support keys 400. Typically, there are three or more hole wall support keys 400, which rotate synchronously with the base. Each hole wall support key 400 is disposed on the outer periphery (i.e., radial outer edge) of the cutting base 310, protruding from the surface of the cutting base 310. Figure 2 for Figure 1 The schematic diagram shows an embodiment of the radial section of a hole-machining tool, in conjunction with... Figure 1 ,like Figure 2 As shown, in this embodiment, five hole wall support keys are provided on the surface of the cutting substrate 310. Viewed radially from the cutting substrate, the five hole wall support keys achieve five point contacts with the hole wall at different locations, rather than five arc segments of the same diameter making surface contact with the hole wall of the same diameter. This not only achieves more effective support for the hole wall but also minimizes contact and friction with the hole wall.
[0038] Combination Figure 1 ,like Figure 2As shown, the hole wall supporting key 400 comprises a base 410 and a supporting surface 420. The base 410 is arranged on the cutting base 310, and extends in the axial direction and in the radial direction, and has a gap 500 with the hole wall formed by machining. The supporting surface 420 is arranged on the base 410, and is in contact with the hole wall and fills the gap 500. In the radial direction of the cutting base, the outer edge of the supporting surface 420 has a contact point 421 with the hole wall.
[0039] With reference to the feed direction of the tool, the supporting surface 420 comprises a feed front end 423 and a feed rear end 424, and the feed front end 423 is in contact with the hole wall before the feed rear end 424. In the axial direction of the cutting base, the radial gap between the base 410 and the hole wall gradually converges towards the feed front end 423 of the supporting surface, and it appears that the radial gap between the base 410 and the hole wall gradually increases away from the feed front end 423 of the supporting surface in the same direction of the feed direction (see the arrow in the figure). Figure 1 Similarly, in the axial direction of the cutting base, the radial gap between the base 410 and the hole wall gradually converges towards the feed rear end 424 of the supporting surface, and it appears that the radial gap between the base 410 and the hole wall gradually increases away from the feed rear end 424 of the supporting surface in the opposite direction of the feed direction (see the arrow in the figure). Figure 1
[0040] In the axial direction of the cutting base 310, the feed front end 423 of the supporting surface is spaced apart from the tip of the cutting base 300 by ≥0.1 mm, and particularly by 0.7±0.3 mm.
[0041] Figure 3 A schematic view of another embodiment of the hole machining tool of the present application, in which the radial outer edge of the hole machining tool is in contact with the hole wall, Figure 4 A schematic view of another embodiment of the hole machining tool of the present application, in which the radial outer edge of the hole machining tool is in contact with the hole wall, Figure 3 A schematic view of another embodiment of the hole machining tool of the present application, in which the radial outer edge of the hole machining tool is in contact with the hole wall, Figure 1 A schematic view of another embodiment of the hole machining tool of the present application, in which the radial outer edge of the hole machining tool is in contact with the hole wall, Figure 2 A schematic view of another embodiment of the hole machining tool of the present application, in which the radial outer edge of the hole machining tool is in contact with the hole wall, Figure 3 A schematic view of another embodiment of the hole machining tool of the present application, in which the radial outer edge of the hole machining tool is in contact with the hole wall, Figure 4 As shown, in the radial direction of the cutting base 310, the supporting surface is an arc line 421, and the arc line 421 has a contact point 425 with the hole wall 600 on the side of the arc line 421 facing the hole wall 600. The contact point is usually designed to be at the top of the arc line, i.e., on the side of the arc line 421 facing the hole wall 600. Geometric figures such as a circle, an ellipse, a parabola or a hyperbola provide examples of curves having a top for this embodiment, and therefore, with reference to Figure 2 As shown, in the radial direction of the cutting base 310, the supporting surface is an arc line 421, and the arc line 421 has a contact point 425 with the hole wall 600 on the side of the arc line 421 facing the hole wall 600. The contact point is usually designed to be at the top of the arc line, i.e., on the side of the arc line 421 facing the hole wall 600. Geometric figures such as a circle, an ellipse, a parabola or a hyperbola provide examples of curves having a top for this embodiment, and therefore, with reference to
[0042] With reference to Figure 1 As the length of the base 410 extends axially, an arc can be observed on each radial section of the support surface 420, each arc having a contact point with the side of the hole wall. Accordingly, the contact points form a straight line segment arranged axially along the cutting base. The contact points of the hole wall support key 400 with the hole wall in the axial direction of the axis 200 form a line contact in the axial direction.
[0043] The common hole cutter must have a circular arc support section (also known as side blade belt, circular arc residue, and Margin) with a radius comparable to that of the machined hole, and the hole wall is finally machined through this circular arc structure. In the existing common hole machining, the hole wall and the circular arc support section finally have to rub against each other to achieve the machining of the latter on the former, and the cutting fluid (oil) film is used to prevent overheating, shrinkage, and other phenomena caused by excessive friction. The cutting fluid (oil) film works mainly in the process of extreme pressure lubrication (since the extreme pressure of oil is significantly better than that of water, cold oil is preferred in similar machining instead of cooling liquid). In contrast, the cutter of the present embodiment does not use this structure, but instead uses hole wall support keys that are greater in number than the cutting edges. The contact between the hole wall support keys and the hole wall is reduced in the circumferential direction, so that the hole wall and the support keys tend to form point contact. This not only maximizes the length of the oil film cooling the hole wall, but also replaces boundary lubrication with extreme pressure lubrication at the contact points, making it almost impossible for overheating, shrinkage, and other phenomena caused by excessive friction to occur. Since the extreme pressure lubrication state is avoided, the cutter of the present embodiment is suitable for working conditions that are completely achieved by cooling liquid, which significantly improves environmental performance.
[0044] The hole wall support keys are arranged in a dispersed manner, such as a triangular distribution of hole wall support keys, which can significantly disperse the cutting force on the cutting edge to the hole wall, making it difficult to produce periodic cutting force oscillation, and thus avoiding the generation of periodic ripples and deflection in the circumferential direction. Therefore, there is no need for an outer circular residue to iron the hole wall, and the machining effect that requires a circular arc residue support in previous machining can be achieved only through distributed point contact support, with better final surface quality and geometric precision. Compared with existing cutters, the circumference of the circular arc residue of the cutter of the present embodiment is only within 10%.
[0045] In addition, the present embodiment is also significantly different from the roll light cutter. The roll light cutter achieves hole wall smoothing through non-cutting extrusion (also extreme pressure lubrication). Although it is also in point contact with the hole wall, the roll light shaft rotates at high speed while rotating with the cutter, which will cause uneven wear of the roll light shaft and failure. In the present embodiment, the hole wall support keys are fixed to the base and cannot rotate relative to each other.
[0046] The hole machining tool of the embodiment is applied to reaming hole machining, which effectively reduces the frictional heat generated by surface contact and avoids the shrinkage phenomenon, and the multi-point contact also maximizes the liquid film between the blade band and the hole wall to achieve maximum lubrication and obtain the best roughness. On the other hand, the blade band edge is isolated from the hole wall, avoiding the friction of the sharp edge of the blade band to the hole wall during machining and tool withdrawal, causing damage.
[0047] The hole wall effect of the common hole machining tool is that although the roundness is qualified, the high light reflection inspection details can see periodic black lines on the hole wall. These lines are caused by periodic vibration of the reamer periphery when it is in contact with the hole wall. The causes of periodic vibration include excessive extrusion caused by shrinkage, lubricating oil damage, and tool or workpiece vibration. The machining effect of the tool provided in the embodiment under the same working condition can be seen that there are no lines on the hole wall except for fine feed marks, and the hole wall is smooth and round. The roundness and hole wall quality are better.
Claims
1. A hole machining tool, characterized in that Including: The cutting body includes a cutting base and a cutting edge part, the cutting edge part is provided on the cutting base, and the front end in the cutting feed direction; The hole wall support key is provided on the cutting base, located behind the cutting edge part in the cutting feed direction, rotates synchronously with the base, includes a base and a support surface, and the outer edge of the support surface has a contact point with the hole wall in the radial direction of the cutting base. The radial outer edge of each part of the support surface has a contact point with the hole wall, and all or part of these contact points present straight line segments arranged in the axial direction of the cutting base; The number of the hole wall support keys is at least more than 2 than the cutting edge part.
2. A bore machining tool according to claim 1, characterised in that The base is arranged on the cutting base, and has a gap with the hole wall formed by machining. The support surface fills part of the gap.
3. The bore machining tool according to claim 1, characterized in that The base is arranged on the cutting base, and the radial gap between the base and the hole wall gradually converges towards the feeding front end of the support surface in the axial direction of the cutting base.
4. The bore machining tool according to claim 1, characterized in that The base is arranged on the cutting base, and the radial gap between the base and the hole wall gradually converges towards the feeding rear end of the support surface in the axial direction of the cutting base.
5. The bore machining tool according to claim 1, characterized in that From the radial direction of the cutting base, an arc line can be observed on each radial section of the support surface, and each arc line has a contact point with the hole wall on one side of the hole wall.
6. A bore machining tool according to claim 5, characterised in that The shape of the arc line is a part of a circle, an ellipse, a parabola or a hyperbola.
7. The bore machining tool according to claim 1, characterized in that From the radial direction of the cutting base, an arc line can be observed on each radial section of the support surface, and each arc line has a contact point with the hole wall on one side of the hole wall.
8. The bore machining tool according to claim 1, characterized in that There are 3 hole wall support keys, and each hole wall support key is arranged on the outer periphery of the cutting base and protrudes from the surface of the cutting base.
9. The bore machining tool according to claim 1, characterized in that There are 5 or more hole wall support keys, and each hole wall support key is arranged on the outer periphery of the cutting base and protrudes from the surface of the cutting base.
10. The bore machining tool according to claim 1, characterized in that The feeding front end of the support surface and the front end of the cutting body are ≥0.1mm in the axial direction of the cutting base.