KR102412141B1 - Tungsten Carbide Center and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a cemented carbide center and a method for manufacturing the same. can provide
In addition, the basic processing step of heat-treating and processing the material to form the shape of the center; Grooving step of forming a groove in the head of the machined center; A cemented carbide center manufacturing method comprising a cemented carbide coating step of forming a cemented carbide coating layer through high-speed thermal spray coating on the head and a precision machining step of machining the head using a diamond grinding stone to complete the carbide center can be provided.

Description

Tungsten Carbide Center and manufacturing method thereof

The present invention relates to a cemented carbide center and a method for manufacturing the same, and more particularly, by forming a cemented carbide coating layer on a part that is easily worn by fixing or rotating the processed product during processing, high-speed thermal spray coating prevents damage to the processed product and reduces the wear rate It relates to a carbide center having a low service life and a method for manufacturing the same.

The tool industry is a consumable product that is used from general users to the entire manufacturing industry, and the use of excellent tools in related industries such as machinery, automobiles, shipbuilding, aviation, electricity, electronics, optics, semiconductors, construction, and materials (non-ferrous metals, steel) is related. It enables product quality improvement and technology development, and it is shown to have a significant impact on cost reduction and productivity enhancement.

Among the tool industry, the cutting tool industry is a core-based industry that has a large ripple effect on related industries as it is consumable, but it is a technology-intensive small and medium-sized industry that produces small quantities of various types, so mass production is impossible and it is a capital-intensive business with many difficulties in process automation.

In addition, it is a typical know-how industry that takes a lot of time to accumulate technology as it is a material industry with a high cost composition of raw materials.

Among tools, the center is a part that fixes the workpiece during machining, and there are live centers and pipe centers.

Live center refers to rotating to fix the end of the workpiece on the lathe, and the pipe center refers to fixing the end to machine the pipe on the lathe.

When the bearing located at the bottom of the existing center rotates at high speed, vibrations of about 1/1000 to 2/1000 microns generally occur. there was

In addition, since the existing center consists of only general heat treatment, there is a problem in that the center is easily worn when the machine rotates repeatedly, and as the worn part becomes weaker and the number of friction increases, it becomes difficult to withstand the force.

As a result, the defective rate of the processed product increases, and consequently, the consumption of the processed product increases, thereby reducing the efficiency of manufacturing compared to input of material cost.

In order to solve the above problems, the present invention forms a cemented carbide coating layer with high-speed thermal spray coating on a part that is easily worn by fixing or rotating the processed product during processing, thereby preventing damage to the processed product and reducing the wear rate to reduce the service life. An object of the present invention is to provide an extended carbide center and a method for manufacturing the same.

In order to solve the above problems, the cemented carbide center according to a first embodiment of the present invention is formed to be inclined upwardly from the front end to the rear side and includes a head portion including an inclined portion on which a cemented carbide coating layer is formed, and a shaft portion connected to the head portion A carbide center can be provided.

Here, the inclined portion is characterized in that the angle (α) is 55 to 65 °.

In addition, the cemented carbide coating layer is characterized in that it is formed to a thickness of 0.3 to 0.4T.

In addition, the shaft part may include one or more fixing grooves formed along the outer circumferential surface at the rear side.

In addition, the inclined portion of the carbide center according to the second embodiment of the present invention, one or more member grooves formed along the outer peripheral surface; one or more springs installed in the member groove; It is possible to provide a cemented carbide center including a guide bar installed in the member groove and a pressing member including a guide groove inserted into the member groove, the spring is connected, and the guide groove is inserted into the member groove.

In addition, the head portion of the carbide center according to the third embodiment of the present invention includes a plurality of head coupling protrusions formed along the outer peripheral surface of the rear surface and a fastening groove formed in the center of the rear surface, the shaft body formed to have a length; a protrusion plate formed in a plate shape on the front side of the shaft body; It is possible to provide a cemented carbide center comprising a shaft coupling protrusion formed along the front outer circumferential surface of the protrusion plate to be coupled to the head coupling protrusion, and one or more fastening protrusions formed along the outer circumferential surface of the front end of the shaft body and inserted into the fastening groove.

In addition, the method for manufacturing a carbide center according to an embodiment of the present invention includes a basic processing step of heat-treating and processing the material to form the shape of the center; Grooving step of forming a groove in the head of the machined center; A cemented carbide center manufacturing method comprising a cemented carbide coating step of forming a cemented carbide coating layer through high-speed thermal spray coating on the head and a precision machining step of machining the head using a diamond grinding stone to complete the carbide center can be provided.

Here, the basic processing step is a temper treatment step of tempering the material; A shape processing step of processing the tempered material to form a shape of the center; It may include a surface heat treatment step of carburizing the shape-processed center and a grinding step of grinding the shaft portion of the center.

In addition, the basic processing step is characterized in that the processing is performed so that the angle (taper angle) of the inclined portion when forming the head portion of the center is 55 to 65 °.

In addition, the cemented carbide coating step is characterized in that the tungsten carbide powder is used to form a cemented carbide coating layer through high-speed thermal spray coating.

In addition, the cemented carbide coating step is characterized in that the formation of the cemented carbide coating layer to a thickness of 0.3 to 0.4T.

In addition, after the precision machining step, it may further include a precision grinding step of grinding the shaft portion of the carbide center.

In addition, after the precision processing step, by processing the inclined portion of the carbide center may further include an assembling step of assembling a spring, a guide bar and a pressing member.

The cemented carbide center and its manufacturing method according to the embodiment of the present invention as described above by forming a cemented carbide coating layer on a part that is easily worn by fixing or rotating the processed product during processing, the strength is improved and the wear rate is improved. low, which can prolong the service life.

In addition to this, it is possible to improve the efficiency of product manufacturing by preventing damage to the processed product.

In addition, by using tungsten carbide powder during high-speed thermal spray coating, it can be manufactured to be lighter in weight compared to other cemented carbide materials, thereby improving user convenience.

1 is a perspective view showing a cemented carbide center according to a first embodiment of the present invention.
Figure 2 is a side view showing a cemented carbide center according to the first embodiment of the present invention.
Figure 3 is a perspective view showing a state in which the fixing groove is included in the carbide center of Figure 1;
Figure 4 is a perspective view showing a carbide center according to a second embodiment of the present invention.
Figure 5 is a side cross-sectional view showing the carbide center of Figure 4;
Figure 6 is a perspective view showing a carbide center according to a third embodiment of the present invention.
7 (a) and (b) are a perspective view and a rotational perspective view showing the carbide center of FIG. 6 separated.
8 is a flowchart schematically showing a method for manufacturing a carbide center according to an embodiment of the present invention.
9 is a flowchart sequentially illustrating step S1 of FIG. 8;

Hereinafter, the description of the present invention with reference to the drawings is not limited to specific embodiments, and various modifications may be made and various embodiments may be provided. In addition, it should be understood that the contents described below include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention.

In the following description, terms such as 1st, 2nd, etc. are terms used to describe various components, meanings are not limited thereto, and are used only for the purpose of distinguishing one component from other components.

Like reference numbers used throughout this specification refer to like elements.

As used herein, the singular expression includes the plural expression unless the context clearly dictates otherwise. In addition, terms such as "comprises", "comprises" or "have" described below are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist. It should be construed as not precluding the possibility of addition or existence of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings 1 to 9.

Figure 1 is a perspective view showing a carbide center according to a first embodiment of the present invention, Figure 2 is a side view showing a carbide center according to a first embodiment of the present invention, Figure 3 is fixed to the carbide center of Figure 1 It is a perspective view showing a state including a groove.

1 and 2 , the cemented carbide center 1 according to the first embodiment of the present invention may include a head portion 10 and a shaft portion 20 .

The head part 10 is a part that is inserted into the workpiece to support the workpiece, and may include an inclined part 11 , a cylindrical part 12 , and a front groove 13 .

The inclined portion 11 is tapered to be inclined upwardly from the front end to the rear, and may be formed to have a flat front surface. By being inclined in this way, when it is inserted into the workpiece, it is possible to make line contact with the workpiece rather than surface contact, so that less friction is generated.

In this case, the angle (taper angle, α) of the inclined portion 11 may be 55 to 65°, and more preferably 60°.

If it is smaller than 55°, it may not be able to withstand the force generated by rotation, and if it is larger than 65°, there may be a limit to fixing the workpiece.

In addition, the inclined portion 11 may include a cemented carbide coating layer 110 formed in order to improve strength and lower the wear rate to prevent damage to the workpiece.

The cemented carbide coating layer 110 may be formed through high-speed thermal spray coating using tungsten carbide powder.

Here, the high-speed thermal spray coating is HVOF (High Velocity Oxy-Fuel Spraying) high-speed thermal spray coating, which is a method of coating by spraying a high-pressure and high-speed flame through a separate combustion chamber that mixes fuel with oxygen and burns it and a supersonic nozzle. Compared to other thermal spray coatings, it has fewer pores and has the advantage of being able to coat with a relatively dense structure.

In addition, since the cemented carbide coating layer 110 is made of tungsten carbide powder, it has excellent wear resistance and corrosion resistance, can reduce material costs, and is light in weight compared to other cemented materials, thereby improving user convenience.

In addition, the cemented carbide coating layer 110 is preferably formed to a thickness of 0.3 to 0.4T, which may have insignificant effects such as hardness improvement and prevention of damage to the workpiece when it is less than 0.3T, and when it is more than 0.4T, material cost improvement and weight improvement , problems such as center bending may occur.

The cylindrical part 12 may be formed to extend toward the rear side of the inclined part 11 . At this time, it may form a cylindrical shape, but is not limited thereto.

The front groove 13 may be formed on the front surface of the head part 10 . This front groove 13 is formed in order to prevent the distal end of the head portion 10 from being damaged or dropped by the impact.

In addition, the front diameter (φ ₁ ) of the head part 10 is 12 to 46 mm, the rear diameter (φ ₂ ) is 56 to 98 mm, the length (L ₁ ) is 64 to 91 mm, the length of the cylindrical part 12 (L ₂ ) ) may be 15 to 25 mm, but is not limited thereto.

For example, when manufactured as a live center, the conditions as shown in Table 1 below may be satisfied, and when manufactured as a pipe center, the conditions as shown in Table 2 below. It is preferably made under such conditions, but it is not limited because it is an example.

φ ₁ φ ₂ L ₁ L ₂ α 18 56 64 15 60 30 78 71 18 60 40 98 91 23 60

φ ₁ φ ₂ L ₁ L ₂ α 12 56 68 15 60 30 78 74 18 60 46 98 86 20 60

The shaft part 20 is a part fixed by a fixing device of the center when in use, is formed in a circular bar shape having a length, and may be formed to be connected to the head part 10 .

At this time, the shaft portion 20 may be formed in a shape in which the diameter gradually decreases from the front end to the rear end, but is not limited thereto.

In addition, the length (L ₃ ) of the shaft portion may be 84 to 136 mm, but is not limited thereto.

Referring to FIG. 3 , the shaft part 20 may include a fixing groove 21 in order to improve the fixing force by the fixing device.

One or more fixing grooves 21 may be formed on the rear side along the outer circumferential surface, and are preferably formed to be spaced apart from each other, but are not limited thereto.

In addition, the carbide center 1 according to the first embodiment of the present invention may further include an optical sensor (not shown).

The optical sensor (not shown) is provided so as to be detachably attached to the front center of the head unit 10, so that when used to fix a workpiece, it can be confirmed whether the carbide centers installed symmetrically to each other are parallel to each other. It is preferable to use it when the workpiece is a pipe, and it is not limited thereto, and can be easily applied in the case of a workpiece having a penetrating inside.

That is, as the optical sensor is operated, by irradiating light toward the center installed to face each other, parallelism can be measured, and the measured information can be transmitted to the user's terminal or server so that the user can check it.

Figure 4 is a perspective view showing a carbide center according to a second embodiment of the present invention, Figure 5 is a side cross-sectional view showing the carbide center of Figure 4.

4 and 5, the inclined portion 11 of the carbide center 1 according to the second embodiment of the present invention is a member groove 111, a spring 112, a guide bar 113 and a pressing member ( 114) may be included.

Here, except for the member groove 111, the spring 112, the guide bar 113 and the pressing member 114, the carbide center according to the second embodiment of the present invention is the first embodiment of the present invention described above. It is substantially the same as the carbide center according to

Accordingly, only the member groove 111 , the spring 112 , the guide bar 113 and the pressing member 114 will be described.

One or more member grooves 111 may be formed along the outer circumferential surface of the inclined portion 11. When a plurality of member grooves 111 are formed, they may be formed to be spaced apart at a predetermined angle along the outer circumferential surface.

One or more springs 112 may be installed on the inner surface of the member groove 111 and connected to the pressing member 114 .

The guide bar 113 is formed to have a length and may be installed in the member groove 111 to face the outside.

The pressing member 114 may be formed in a thin plate shape and installed to be inserted into the member groove 111 .

In addition, the spring 112 is connected to the inner surface and pressed as the center is inserted into the workpiece to receive the force by the spring 112 . Accordingly, the pressing member 114 is applied with a force to go outward by the spring 112 so that the fixing force to the workpiece is further improved.

In addition, the pressing member 114 may include a guide groove to prevent separation or torsion in the member groove 111 .

The guide groove is formed on the inner surface of the pressing member 114 so that the guide bar 113 can be inserted, and the guide bar 113 can be moved inside according to the movement of the pressing member 114 .

In addition, the pressing member 114 is formed upward from the front end to the rear end so that the outer surface corresponds to the outer surface of the inclined portion 11, the inclination may be formed at 55 to 65 °.

Through such a configuration, the cemented carbide center 1 may have a higher fixing force than when fixing the workpiece.

6 is a perspective view illustrating a carbide center according to a third embodiment of the present invention, and FIGS.

6 and 7, the cemented carbide center 1 according to the third embodiment of the present invention may be formed in a separate type. ), and the shaft part 20 may include a shaft body 22 , a protrusion plate 23 , a shaft coupling protrusion 24 and a fastening protrusion 25 .

Here, except for the head coupling protrusion 14, the fastening groove 15, the shaft body 22, the protrusion plate 23, the shaft coupling protrusion 24 and the fastening protrusion 25, the third embodiment of the present invention The cemented carbide center according to the first embodiment of the present invention described above is substantially the same.

Accordingly, only the head coupling protrusion 14 , the fastening groove 15 , the shaft body 22 , the protruding plate 23 , the shaft coupling protrusion 24 and the fastening protrusion 25 will be described.

The head unit 10 may further include a head coupling protrusion 14 and a fastening groove 15 .

A plurality of head coupling protrusions 14 are formed along the rear outer circumferential surface of the head unit 10 , and may be coupled to the shaft coupling protrusions 24 of the shaft unit 20 .

The fastening groove 15 is formed in the center of the rear surface of the head part 10 , and the shaft body 22 and the fastening protrusion 25 may be inserted thereinto.

The shaft part 20 may include a shaft body 22 , a protrusion plate 23 , a shaft coupling protrusion 24 and a fastening protrusion 25 .

The shaft body 22 may be formed in a circular bar shape having a length, and as described above, may be formed such that the diameter gradually decreases from the front end to the rear end.

The protrusion plate 23 is formed in a plate shape corresponding to the shape of the cylindrical part 12 of the head part 10 , and may be positioned on the front side of the shaft body 22 .

A plurality of shaft coupling protrusions 24 are formed along the outer peripheral surface of the front surface of the protrusion plate 23 , and may be coupled to the head coupling protrusions 14 .

A plurality of fastening protrusions 25 may be formed at a predetermined distance along the outer circumferential surface at the front end of the shaft body 22 . This fastening protrusion 25 is inserted into the fastening groove 15, so that, when it is rotated by the fixing device of the center, the rotational force can be transmitted to the inside of the head 10 to which the weight of the workpiece is applied, so that the head 10. Since the diameter is formed smaller, the load applied to the shaft part 20, which is a weak part, can be further reduced.

A method of manufacturing a cemented carbide center according to the first to third embodiments of the present invention described above will be described in more detail below.

8 is a flowchart schematically illustrating a method for manufacturing a cemented carbide center according to an embodiment of the present invention, and FIG. 9 is a flowchart sequentially illustrating steps S1 of FIG.

8, the carbide center manufacturing method according to an embodiment of the present invention is a basic processing step (S1), a groove processing step (S2), a cemented carbide coating step (S3), a precision processing step (S4) and a precision grinding step ( S5) may be included.

Specifically, in the basic processing step (S1), the material is heat-treated to improve core hardness, strength, etc., lower the surface layer abrasion, and process the material to form the shape of the center.

Referring to FIG. 9 , step S1 may include a tempering step (S10), a shape processing step (S11), a surface heat treatment step (S12), and a grinding step (S13).

The tempering step (S10) is a step of tempering the material to improve core hardness, etc., and quenching (quenching) and high temperature tempering may be performed.

Quenching (quenching) is a heat treatment method in which a material is heated to an appropriate temperature and then rapidly cooled, which can increase the hardness and strength of steel.

Quenching in step S10 may proceed by quenching at 850 to 870° C. for 2.5 to 3.5 hours, then quenching in a heat treatment oil cooling bath, and then maintaining at 60 to 80° C. for 20 to 30 minutes.

High temperature tempering is a heat treatment method that can improve the hardness of the hardened material, but internal stress due to rapid cooling may be accumulated. . It may be carried out at 550 to 650 °C.

The high-temperature tempering of step S10 may proceed by heating at 635° C. and then maintaining it for 3 hours.

In the shape processing step (S11), the shape of the center may be formed by processing the tempered material, but may be a step of making the shape of the head portion 10 of the cemented carbide center 1, but is not limited thereto.

In this case, in step S11, the angle (taper angle, α) of the inclined portion may be 55 to 65° when forming the head of the center, and it may be more preferable to process to 60°.

In the surface heat treatment step (S12), the shape-processed center may be carburized to make the surface layer into a high-carbon structure to be hardened.

Carburizing heat treatment is a method of making only the surface layer into a high-carbon structure by burying low-carbon steel or low-carbon alloy steel with a carbon content of less than 0.2% in a carburizing agent, heating it to the austenite range, and then infiltrating and diffusing carbon into the surface.

In step S12, the carburizing heat treatment is heat-treated at 850 to 870° C. for 2.5 to 3.5 hours, then quenched in a heat treatment oil cooling tank, maintained at 60 to 80° C. for 20 to 30 minutes, heated at 220° C., and maintained for 3 hours. have.

In the grinding step (S13), the shape of the shaft part 20 may be made by grinding the carburizing heat-treated center, but the shape of the shaft part 20 is not limited thereto. When necessary, the shaft portion 20 may be formed by grinding other materials.

In the grooving step (S2), a groove may be formed in the head of the machined center using a ceramic bite. This is to improve bonding strength with the cemented carbide coating layer 110 . In addition, processing of the front groove 13 may be made in step S2.

In the cemented carbide coating step (S3), the cemented carbide coating layer 110 may be formed on the head portion 10 through high-speed thermal spray coating. Preferably, the cemented carbide coating layer 110 is formed on the inclined portion 11 of the head portion 10. It can be formed, and the coating can be made using tungsten carbide powder.

At this time, as the coating is performed in 3 to 5 phases (the spray coating device reciprocates 3-5 times and sprays the powder on the inclined surface), workability can be increased to improve the completeness of the product. Four-phase is more preferable, but is not limited thereto.

In the precision processing step (S4), the inclined portion 11 of the head portion 10 on which the cemented carbide coating layer 110 is formed in the step S3 may be precisely machined with a diamond grinding stone. This is to ensure that the formed cemented carbide coating layer 110 has a more uniform surface (smooth surface).

The precision grinding step S5 may precisely grind the shaft 20 . This is preferably done as an auxiliary step, but may not be included.

In addition, in step S5, the fixing groove 21 may be formed.

In addition, the carbide center manufacturing method according to an embodiment of the present invention may further include an assembling step (not shown).

In the assembling step (not shown), the spring 112 , the guide bar 113 and the pressing member 114 may be assembled by processing the inclined portion 11 of the cemented carbide center 1 .

At this time, when machining the inclined portion 11 in the assembly step, the member groove 111 may be formed, and a groove in which the spring 112 and the guide bar 113 may be installed may be formed.

As described above, in the cemented carbide center and its manufacturing method according to an embodiment of the present invention, the strength is improved by forming a cemented carbide coating layer on a part that is easily worn by fixing or rotating the processed product during processing by high-speed thermal spray coating. The wear rate is low and the service life can be extended.

In addition to this, it is possible to improve the efficiency of product manufacturing by preventing damage to the processed product.

In addition, by using tungsten carbide powder during high-speed thermal spray coating, it can be manufactured to be lighter in weight compared to other cemented carbide materials, and thus user convenience can be improved.

In the above description, the carbide center according to the embodiment of the present invention has been described by dividing it into first to third embodiments, which have been described by dividing the embodiments for convenience and easy understanding of the description, and are not limited to each embodiment. , the configuration of the embodiment can be applied to each other by changing the design.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those of ordinary skill in the art to which the present invention pertains can practice the present invention in other specific forms without changing the technical spirit or essential features of the present invention. you will be able to understand Accordingly, the embodiments described above are illustrative in all respects and not restrictive.

1: Carbide Center
10: head
11: slope
110: carbide coating part
111: member groove
112: spring
113: guide bar
114: pressing member
12: cylindrical part
13: front groove
14: head coupling projection
15: fastening groove
20: shaft part
21: fixed groove
22: shaft body
23: stone plate
24: shaft coupling projection
25: fastening protrusion

Claims (10)

A head part which is formed to be inclined upward from the front end to the rear side, the front surface is formed to have a flat surface, and an inclined part on which a cemented carbide coating layer is formed, and a front groove formed on the front surface;
and a shaft part connected to the head part;
The cemented carbide coating layer,
Cemented carbide center, characterized in that it is formed through high-speed thermal spray coating using tungsten carbide powder.
According to claim 1,
The inclined portion,
Cemented carbide center, characterized in that the angle (α) is 55 to 65 °.
According to claim 1,
The cemented carbide coating layer,
Carbide center, characterized in that formed to a thickness of 0.3 to 0.4T.
According to claim 1,
The shaft part,
A cemented carbide center comprising one or more fixing grooves formed along the outer circumferential surface at the rear.
According to claim 1,
The inclined portion,
one or more member grooves formed along the outer circumferential surface;
one or more springs installed in the member groove;
a guide bar installed in the member groove; and
Carbide center including a pressing member including a guide groove is inserted into the member groove is connected to the spring, the guide bar is inserted into the movable.
According to claim 1,
The head part,
A plurality of head coupling protrusions formed along the rear outer circumferential surface, and
Including a fastening groove formed in the center of the rear,
The shaft part,
a shaft body formed to have a length;
a protrusion plate formed in a plate shape on the front side of the shaft body;
a shaft coupling protrusion formed along the outer circumferential surface of the front surface of the protrusion plate and coupled to the head coupling protrusion; and
A cemented carbide center including one or more fastening protrusions formed along the outer peripheral surface of the front end of the shaft body and inserted into the fastening groove.
A basic processing step of heat-treating and processing the material to form the shape of the center;
Grooving step of forming a groove in the head of the machined center;
A cemented carbide coating step of forming a cemented carbide coating layer through high-speed thermal spray coating on the head part; and
Including a precision processing step of machining the head part using a diamond grinding stone to complete a carbide center,
The basic processing step is,
a temper treatment step of tempering the material;
a shape processing step of processing the tempered material to form the shape of the head of the center;
A surface heat treatment step of carburizing the shape-processed center, and
Including a grinding step of grinding the shaft portion of the center,
The shape processing step is,
The inclined portion of the head portion is formed to be inclined upward from the front end to the rear, and the front surface is processed to have a flat surface,
The groove processing step,
A front groove is machined on the front surface of the inclined part,
The cemented carbide coating step,
A method for manufacturing a cemented carbide center, characterized in that the tungsten carbide powder is used to form a cemented carbide coating layer through high-speed thermal spray coating.
delete delete delete

Images