CN110355389B - Cutter and method for reducing workpiece roughness under low-rotation-speed turning working condition - Google Patents

Abstract

The invention discloses a cutter and a method for reducing workpiece roughness under the working condition of low-speed turning, wherein the cutter comprises: cutter body, tool bit and connecting piece. The cutter head is connected with the cutter body through the connecting piece; the front end of the cutter head is provided with a blade, the front end of the blade is provided with a cutting edge, and the width of the cutting edge is larger than that of a workpiece to be machined. According to the cutter and the method for reducing the roughness of the workpiece under the low-rotation-speed turning working condition, the width of the cutting edge is larger than that of the workpiece to be machined, the cutting edge completely covers the workpiece to be machined in the machining process, the surface roughness of the workpiece to be machined is reduced through a one-pass forming turning mode, the cutter and the method are suitable for machining the workpiece under the low-rotation-speed turning working condition, and the surface quality of the workpiece is improved.

Description

Cutter and method for reducing workpiece roughness under low-rotation-speed turning working condition

Technical Field

The invention relates to the technical field of turning, in particular to a cutter and a method for reducing workpiece roughness under a low-rotation-speed turning working condition.

Background

In machining, a lathe mainly performs turning on a rotating workpiece by using a lathe tool. The cutting energy for turning is mainly provided by the rotation of the workpiece. During turning, different cutters are selected according to different materials of the machined part, and the ideal effect can be achieved only by cutting under corresponding working conditions. The specific cutting condition can be summarized into three cutting factors: cutting speed, feed rate and depth of cut. The feeding amount and the cutting depth can be freely controlled, but the cutting speed is mainly provided by the rotation of the lathe chuck and is related to the diameter of the workpiece to be processed, and the cutting speed V is pi nD, wherein n is the rotating speed of the workpiece, and D is the diameter of the workpiece. Generally, in the turning process, the finish machining uses a higher rotation speed to obtain higher surface quality, so that the roughness of the workpiece surface is lower.

In actual production, the situation that the surface quality of the processed workpiece is high (namely, a small roughness value is required) but the workpiece cannot rotate on a machine tool at a high speed for various reasons is often encountered. For example, when a winding drum is machined, the winding drum is formed by assembling and welding a drum body and a winding drum shaft (see the attached drawing 1), the difference between the diameter of the drum body and the diameter of a shaft head is large, when the diameter of the drum body of the winding drum reaches phi 2000mm, the winding drum shaft may only have phi 120mm, a machine tool needs to drive the whole workpiece to rotate, the lathe cannot rotate at a high speed due to the large diameter of the drum body of the winding drum and the unbalance, and the cutting linear speed cannot reach the cutting linear speed required by the finish machining of the shaft head when the winding drum shaft is cut due to the small diameter of the winding drum shaft, so that. Therefore, there is a need for a tool and method for reducing workpiece roughness at low turning speeds to improve the quality of the machined surface.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention provides a cutter and a method for reducing the roughness of a workpiece under the working condition of low-speed turning. The specific technical scheme is as follows:

in a first aspect, a tool for reducing workpiece roughness under low speed turning conditions is provided, the tool comprising: the cutter body, the cutter head and the connecting piece; the cutter head is connected with the cutter body through the connecting piece; the front end of the cutter head is provided with a blade, the front end of the blade is provided with a cutting edge, and the width of the cutting edge is larger than that of a workpiece to be machined.

In one possible design, the connecting piece is of a zigzag structure.

In one possible design, the cutting edge is W18Cr4V high speed steel.

In one possible design, the rake angle of the cutting edge is designed to be 12 degrees and the relief angle is designed to be 6 degrees.

In one possible design, the rake and relief angles of the insert are both 6 degrees.

In one possible design, the surface roughness of the tool tip is less than Ra3.2.

In one possible design, the surface roughness of the insert is ra0.8 or less.

In one possible design, the surface roughness of the cutting edge is ra0.8 or less.

In one possible design, the tool is a one-piece structure that is integrally forged.

In a second aspect, a method for reducing workpiece roughness under low speed turning conditions is provided, the method comprising:

roughly processing a workpiece to be processed, wherein the allowance left on one side is 0.3 mm;

and finishing the workpiece to be machined by using the cutter.

The technical scheme of the invention has the following main advantages:

according to the cutter and the method for reducing the roughness of the workpiece under the low-rotation-speed turning working condition, the width of the cutting edge is larger than that of the workpiece to be machined, the cutting edge completely covers the workpiece to be machined in the machining process, the surface roughness of the workpiece to be machined is reduced in a one-pass forming turning mode, and the surface quality of the workpiece is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic view of a roll structure according to the background art;

FIG. 2 is a front view of a tool for reducing workpiece roughness for low speed turning according to an embodiment of the present invention;

FIG. 3 is an enlarged partial front view of a tool for reducing workpiece roughness for low speed turning in accordance with an embodiment of the present invention;

FIG. 4 is a top view of a tool for reducing workpiece roughness for low speed turning according to an embodiment of the present invention.

FIG. 5 is an enlarged view of a portion of an insert and cutting edge of a tool for reducing workpiece roughness for low speed turning according to one embodiment of the present invention.

Description of reference numerals:

1-cutter body, 2-cutter head, 3-connecting piece, 4-blade and 5-blade.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

The technical scheme provided by the embodiment of the invention is described in detail below with reference to the accompanying drawings.

In a first aspect, an embodiment of the present invention provides a tool for reducing workpiece roughness under low-speed turning conditions, as shown in fig. 2 to 5, the tool comprising: the cutter body 1, the cutter head 2 and the connecting piece 3; the cutter head 2 is connected with the cutter body 1 through a connecting piece 3; the front end of the cutter head 2 is provided with a blade 4, the front end of the blade 4 is provided with a cutting edge 5, and the width of the cutting edge 5 is larger than that of a workpiece to be processed.

According to the cutter for reducing the roughness of the workpiece under the low-rotation-speed turning working condition, the width of the cutting edge 5 is larger than that of the workpiece to be machined, the cutting edge 5 completely covers the workpiece to be machined in the machining process, the surface roughness of the workpiece to be machined is reduced through a one-edge forming turning mode, and the surface quality of the workpiece is improved.

It will be appreciated that the cutting edge 5 is a straight edge to ensure turning quality, and the junction between the cutting edge 5 and the insert 4 may be a smooth transition of an arc.

Alternatively, in the embodiment of the present invention, as shown in fig. 2, the connecting member 3 has a zigzag structure. Taking the direction shown in the attached figure 2 as a reference, the connecting piece 3 comprises two opposite vertical plates and a semicircular plate piece connected to the upper ends of the two vertical plates to form a bent half-runway-shaped structure. With such an arrangement, vibration during low-speed turning can be reduced.

Wherein, the connecting part 3 and the junction of cutter body 1 and tool bit 2 and the inside corner of connecting piece 3 can be provided with the fillet respectively to make the transition mild, the surface of cutter is more slick and sly.

In tool design, the rake and relief angles of the tool are important design factors. The rake angle is large, the cutting edge is sharp, the plastic deformation and the frictional resistance of the cutting layer are reduced during cutting, the cutting is light and fast, and the cutting chips are cut off easily; the rake angle is large, the deformation is small during cutting, and the cutting temperature can be reduced; however, too large rake angles can weaken the cutting edge, degrade heat dissipation conditions, reduce tool life, and even cause edge chipping. The increased clearance angle can reduce friction, improve the processing quality of workpieces and the durability of tools, and make the cutting edge sharp. The back angle increases, and cutting edge 5 is sharp, easily cuts into, has reduced the friction of back knife face with the machined surface, has reduced the wearing and tearing of cutter, is favorable to improving the machined surface quality. If the clearance angle is too large, the strength of the blade 5 is weakened, and the heat radiation condition is deteriorated to lower the durability of the cutter. Based on the above, in the embodiment of the present invention, referring to fig. 2 and fig. 3, the front angle of the cutting edge 5 is designed to be 12 degrees, and the front angle can reduce cutting deformation, reduce friction between the cutting edge and the chips, make the cutting edge sharp, and facilitate cutting the chips; the back angle is designed to be 6 degrees, so that the friction between the cutter and a machined surface can be effectively prevented, and the integral strength of the cutting edge is ensured. The design of the front angle and the back angle reduces the resistance of the cutter during large-area cutting and improves the cutting efficiency.

Alternatively, the blade 4 and the cutting edge 5 may be made of W18Cr4V high-speed steel, which ensures the strength and good toughness of the blade 4, and is not easy to break during cutting.

Alternatively, in the present embodiment, the rake angle and the relief angle of the blade 4 are both 6 degrees.

In order to ensure the machining quality, the surface roughness of the tool bit 2 is Ra3.2 or less. The surface roughness of the insert 4 is Ra0.8 or less. The surface roughness of the cutting edge 5 is Ra0.8 or less. The roughness of the surface of the tool is strictly controlled, so that the surface roughness of the turned workpiece meets the use requirement.

Alternatively, referring to fig. 4, the cutting head 2 is a frustum-shaped structure with a size gradually decreasing from the front end to the rear end, and the included angle with the horizontal plane may be 3-5 degrees, for example, 3 degrees, 4 degrees, 5 degrees, and the like. The included angle between the vertical plane and the vertical plane can be 3-5 degrees, for example, 3 degrees, 4 degrees, 5 degrees and the like.

Optionally, in an embodiment of the present invention, the cutter is an integrally forged and integrally formed structure. So set up, guarantee the homogeneity of cutter, avoid taking place power transmission inequality at the junction, improve the lathe work effect.

In a second aspect, an embodiment of the present invention provides a method for reducing roughness of a workpiece under a low-speed turning condition, where the method includes:

and (4) roughly processing the workpiece to be processed, wherein the allowance left on one side is 0.3 mm.

And finishing the workpiece to be machined by using the cutter.

So set up, fall a large amount of unnecessary parts through rough machining process turning, can improve work efficiency, leave 0.3 mm's unilateral surplus, obtain the work piece that satisfies the user demand through follow-up finish machining operation. Therefore, according to the method for reducing the roughness of the workpiece under the low-rotation-speed turning working condition, provided by the embodiment of the invention, the workpiece to be processed is subjected to finish machining by using the cutter, the width of the cutting edge 5 is greater than that of the workpiece to be processed, the cutting edge 5 completely covers the workpiece to be processed in the machining process, the surface roughness of the workpiece to be processed is reduced by a turning mode of one-pass forming, and the method can be suitable for turning the workpiece at the low rotation speed and improve the surface quality of the workpiece.

It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. In addition, "front", "rear", "left", "right", "upper" and "lower" in this document are referred to the placement states shown in the drawings.

Finally, it should be noted that: the above examples are only for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (10)

1. A tool for reducing workpiece roughness in low speed turning conditions, the tool comprising: the cutter body, the cutter head and the connecting piece;

the cutter head is connected with the cutter body through the connecting piece;

the front end of the cutter head is provided with a blade, the front end of the blade is provided with a cutting edge, and the width of the cutting edge is larger than that of a workpiece to be machined.

2. The tool for reducing workpiece roughness during low speed turning according to claim 1, wherein the connecting member is of a zigzag structure.

3. The tool for reducing workpiece roughness for low speed turning according to claim 1, wherein the cutting edge is W18Cr4V high speed steel.

4. The tool for reducing workpiece roughness for low speed turning as claimed in claim 1 or 3, wherein the rake angle of the cutting edge is designed to be 12 degrees and the relief angle is designed to be 6 degrees.

5. The tool for reducing workpiece roughness for low speed turning as claimed in claim 1, wherein the insert has a rake angle and a relief angle of 6 degrees.

6. The tool for reducing workpiece roughness for low speed turning according to claim 1, wherein the surface roughness of the tool tip is less than ra 3.2.

7. The tool for reducing workpiece roughness for low speed turning according to claim 1, wherein the insert has a surface roughness of less than ra0.8.

8. The tool for reducing workpiece roughness for low speed turning as claimed in claim 1, wherein the surface roughness of the cutting edge is less than ra0.8.

9. The tool for reducing workpiece roughness under the low-speed turning condition according to claim 1 or 2, wherein the tool is of an integrally forged and integrally formed structure.

10. A method for reducing workpiece roughness under low speed turning conditions, the method comprising:

roughly processing a workpiece to be processed, wherein the allowance left on one side is 0.3 mm;

-finishing a workpiece to be machined with a tool according to any one of claims 1-9.

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