Cutting processing system and performance test paper for evaluating discharge responsiveness thereof

A cutting processing system includes: a spindle mounted with a cutting tool in which a lubrication discharge path is formed along the central axis thereof for rotating the cutting tool; a lance provided inside the spindle in order to supply oil and air to the cutting tool; and a rotary union mounted on the end portion of the spindle for supplying the oil and the air to the lance in a non-mixed state.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No. 10-2018-0139873, filed on Nov. 14, 2018, which is incorporated herein by reference in its entirety.

BACKGROUND OF THE DISCLOSURE

Field of the Disclosure

The present disclosure relates to a cutting processing system and a performance test paper for evaluating the discharge responsiveness thereof, and more particularly, to a cutting processing system for performing a cutting process by discharging mist mixing oil and air to a workpiece.

Description of Related Art

Products such as an engine and a transmission are manufactured through casting. If necessary, a hole or a groove is formed through cutting. Generally, cutting oil is supplied to a cutting area in order to prevent breakage of a cutting tool (drill), to lower the heat generated in the product, and to prevent the generated chip (iron powder) from floating in the air during the cutting process. However, there is a high possibility that the oil leaks during the cutting process, which pollutes the floor of the treatment facility where the cutting process is performed. Odor is likely to occur as the evaporated oil is contained in the air inside the treatment facility.

Considering this point, a Minimal Quantity Lubrication (MQL) technology has emerged that discharges a minimum amount of mist mixing oil and air to the cut portion in order to prevent pollution of the floor of the treatment facility and occurrence of the odor of the treatment facility by supplying a minimum amount of the oil required for cutting to the cut area to prevent leakage of the oil.

The Minimal Quantity Lubrication technology should discharge the mist mixing air and oil through the cutting tool at the start of the cutting processing. However, the oil is formed at the boundary of the line supplying the mist to the cutting tool, such that it is difficult to discharge the mist mixing air and oil at the start of the cutting process. The discharge responsiveness is low due to a time difference.

In addition, since the supply amount of the oil is minimized, the chip generated at the cutting processing portion may not be separated from the processing portion, such that a technique for separating the chip from the processing portion more smoothly is required.

In addition, it may be selectively used for the cutting processing among various cutting tools if necessary. Therefore, there is a need for a technique capable of evaluating the discharge responsiveness regardless of the type of the cutting tool.

The contents described in Description of Related Art are to help the understanding of the background of the present disclosure and may include what is not previously known to those having ordinary skill in the art to which the present disclosure pertains.

SUMMARY OF THE DISCLOSURE

Accordingly, an object of the present disclosure is to provide a cutting processing system capable of improving the discharge responsiveness of a cutting processing apparatus to which the Minimal Quantity Lubrication technology is applied.

In addition, another object of the present disclosure is to provide a cutting processing system capable of more smoothly separating the chip generated during the cutting processing through the cutting processing apparatus to which the Minimal Quantity Lubrication technology is applied.

In addition, still another object of the present disclosure is to provide a performance test paper for evaluating the discharge responsiveness of the cutting processing system capable of evaluating the discharge responsiveness regardless of the type of the cutting tool.

A cutting processing system according to an embodiment of the present disclosure for achieving the objects includes: a spindle mounted with a cutting tool in which a lubrication discharge path is formed along the central axis thereof and for rotating the cutting tool; a lance provided inside the spindle in order to supply oil and air to the cutting tool; and a rotary union mounted on the end portion of the spindle for supplying the oil and the air to the lance in a non-mixed state.

In addition, the lance may include an internal pipe through which the oil flows and an external pipe being concentric with the internal pipe, disposed outside the internal pipe, and through which the air flows.

In addition, the spindle may include a body having a through hole in which the lance is disposed and a cover mounted on the body to connect the lance and the rotary union.

In addition, the cover may include a first joint fixed to the outside of the through hole for guiding the lance so that one side end portion of the lance is disposed on the central axis of the through hole. The cover may also include a second joint for fixing the rotary union to the first joint in order to maintain the state where the one side end portion of the lance has been fastened with a coupling part of the rotary union.

In addition, the first joint may provide a fastening space into which the coupling part is inserted to be fastened with the lance. The second joint includes a first coupling ring through which the coupling part of the rotary union passes and having the end portion inserted into the fastening space. The second joint also includes a second coupling ring provided between the first joint and the first coupling ring to be concentric with the first coupling ring. The second coupling ring may be fixed to the first joint and the first coupling ring may be fixed to the second coupling ring.

In addition, the spindle may include a drill holder for holding the cutting tool and a rotating part fastened with the drill holder for rotating the drill holder with an external rotational force. The other side end portion of the lance may be protruded from the center of the rotating part. The air and the oil may be received into the drill holder through the lance and then mixed in the state where the drill holder has been fastened to the rotating part.

In addition, the inside of the drill holder may include: a MQL tube being concentric with the cutting tool and into which the other side end portion of the lance is inserted; a steel tube being concentric with the cutting tool and extended from the MQL tube toward the cutting tool; and an adjusting screw in a tubular shape into which one side end portion of the steel tube is inserted and contacting the cutting tool. The one side end portion of the adjusting screw in contact with the cutting tool may be provided to be gradually expanded. The one side end portion of the cutting tool in contact with the adjusting screw may be provided to be gradually reduced.

In addition, the air and the oil may be mixed in the MQL tube.

In addition, the cutting processing system may further include a pneumatic unit for supplying the air to the rotary union, an oil supply unit for supplying the oil to the rotary union, and a controller for controlling operations of the rotary union, the pneumatic unit, and the oil supply unit.

In addition, the pneumatic unit may include a pressure intensifier for intensifying the air received from the outside and a surge tank for receiving and storing the air intensified from the pressure intensifier.

A cutting processing system of an embodiment of the present disclosure for achieving the objects provides a performance test paper for evaluating a discharge responsiveness of a cutting processing system in order to evaluate the discharge responsiveness regardless of the type of cutting tool used. The performance test paper for evaluating the discharge responsiveness of the cutting processing system includes an X-Y coordinate axis, which becomes a reference of the horizontal movement and the vertical movement of the spindle and a plurality of discharge lines illustrated to be horizontal with the X axis of the X-Y coordinate axis in order to become the injecting target of the mixed mist of the oil and the air through the cutting tool. The plurality of discharge lines is arranged at regular intervals along the Y axis of the X-Y coordinate axis.

In addition, the origin (0, 0) of the X-Y coordinate axis may be a lower left corner of the performance test paper.

In addition, a test start position point where the spindle starts rotating may be provided at one side of each of the plurality of discharge lines. A test stop position point where the rotation and movement of the spindle are stopped may be provided at another side of each of the plurality of discharge lines.

In addition, the test start position point and the test stop position point may be horizontal with the plurality of discharge lines and may be provided in the state of being spaced apart from each other to have a distance from each of the plurality of discharge lines.

In addition, a horizontal dimension line for measuring the horizontal movement distance of the spindle may be provided under the plurality of discharge lines. A vertical dimension line for measuring the height movement distance of the spindle and the test cycle may be provided on a side portion of the plurality of discharge lines.

In addition, the performance test paper for evaluating the discharge responsiveness of the cutting processing system may further include a remarks column for writing a test date, a movement speed of the spindle, and a revolutions-per-minute (RPM) of the spindle.

According to the cutting processing system of an embodiment of the present disclosure, it is possible to supply oil and air to the cutting tool in a non-mixed state through the lance, thereby minimizing the mist formation phenomenon and improving the mist discharge responsiveness through the cutting tool.

In addition, it is possible to supply air to the cutting tool in a state further pressurized through the pressure intensifier to discharge the mist to the processing portion at a greater pressure, thereby separating the chip generated during the cutting processing from the processing portion more smoothly.

In addition, it is possible to perform the test actually discharging the mist from the cutting tool toward the performance test paper, thereby evaluating the mist discharge responsiveness through the cutting tool regardless of the type of the cutting tool.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Hereinafter, a cutting processing system according to an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

As illustrated inFIGS. 1-9, a cutting machining system according to an embodiment of the present disclosure includes a spindle100mounted with a cutting tool D on which a lubrication discharge path is formed along the central axis thereof for rotating the cutting tool D. The cutting machining system also includes a lance200provided in the spindle100in order to supply oil and air to the cutting tool D and a rotary union300mounted on the end portion of the spindle100for supplying oil and air to the lance in a non-mixed state. The cutting machining system also includes a pneumatic unit400for supplying the air to the rotary union300, an oil supply unit500for supplying the oil to the rotary union300, and a controller600for controlling operations of the rotary union300, the pneumatic unit400, and the oil supply unit500.

Referring toFIG. 2, the spindle100includes a body110having a through hole111in which the lance200is disposed and a cover120mounted on the body110to connect the lance200and the rotary union300. A shaft112for rotating the cutting tool D and a motor (not illustrated) for rotating the shaft112are provided in the body110. The through hole111in which the lance200is mounted is concentric with the shaft112. As the cover120is provided, the rotary union300may also be mounted on the spindle100without changing the shape thereof, which has been conventionally used.

The cover120is fixed to the outside of the through hole111. The cover120includes a first joint121for guiding the lance200so that one side end portion of the lance200is disposed on the central axis of the through hole111. The cover120also includes a second joint122for fixing the rotary union300to the first joint121in order to maintain the state where one side end portion of the lance200has been fastened with a coupling part310of the rotary union300.

The first joint121provides a fastening space A in which the coupling part310of the rotary union300is inserted for fastening with the lance200. The second joint122includes a first coupling ring123through which the coupling part310of the rotary union300passes, where the end portion thereof is inserted into the fastening space A. The second joint122also includes a second coupling ring124provided between the first joint121and the first coupling ring123to be concentric with the first coupling ring123. The rotary union300is fitted in the first coupling ring123. The position thereof is fixed as it is pressurized by the second coupling ring124.

The second coupling ring124has a fastening hole J2that coincides with a fastening groove J1provided in the first joint121. A bolt B1is fastened to the fastening groove J1of the first joint121and the fastening hole J2of the second coupling ring124so that the second coupling ring124is fixed to the first joint121. The second coupling ring124has a fastening groove J3. The first coupling ring123has a fastening hole J4that is coincident with the fastening groove J3of the second coupling ring124. A bolt B2is fastened to the fastening groove J3of the second coupling ring124and the fastening hole J4of the first coupling ring123so that the first coupling ring123is fixed to the second coupling ring124.

Referring toFIG. 3, the lance200is a double pipe body. The lance200includes an internal pipe210through which the oil flows and an external pipe220concentric with the internal pipe210, disposed outside the internal pipe210, and through which the air flows.

The rotary union300is mounted at one side of the body of the spindle100in the longitudinal direction thereof. The rotary union300includes a pneumatic injecting port320for receiving the air from the pneumatic unit400and an oil injecting port330for receiving the oil from the oil supply unit500.

The rotary union300has the coupling part310coupled with the lance200. The coupling part is provided so that a discharge port311for connecting the internal pipe210of the lance200and the oil injecting port330and a discharge port312for connecting the external pipe220of the lance200and the pneumatic injecting port320to have the form of a double pipe.

The controller600controls the operations of the rotary union300, the pneumatic unit400, and the oil supply unit500according to the shape of the cutting tool D and the cutting conditions, thereby controlling the flow rate of the mist discharged to the cut area through the cutting tool D.

Referring toFIGS. 4 and 5, a rotating part140for rotating the cutting tool D is provided at one side of the body110of the spindle100. The rotating part140is connected to the shaft112provided inside the body110of the spindle100. A drill holder130holding the cutting tool D is mounted on the rotating part140. The drill holder130is rotated by the rotation of the rotating part140. The cutting tool D is ultimately rotated. The end portion of the lance200is protruded from the center of the rotating part140. In the state where the drill holder130has been fastened to the rotating part140, the air and the oil are received into the drill holder130through the lance200and then mixed.

Referring toFIGS. 6-9, an MQL tube131, a steel tube132, and an adjusting screw133are provided in the drill holder130. The MQL tube131is mounted in the drill holder130to be concentric with the cutting tool D. The end portion of the lance200protruded from the center of the rotating part140is inserted into the end portion of the MQL tube131. The oil and the air are mixed on the end portion of the MQL tube131into which the end portion of the lance200has been inserted.

The steel tube132is provided to be concentric with the MQL tube131. The steel tube132is provided to have a length greater than that of the MQL tube131. Therefore, the steel tube132is extended outwards from the inside of the MQL tube131. The inner diameter of the steel tube132is provided to be greater than the outer diameter of the lance200. The end portion of the steel tube132that is present outside the MQL tube131is inserted into the adjusting screw133.

The adjusting screw133is in contact with the cutting tool D. One surface of the adjusting screw133contacting with the cutting tool D is provided to be gradually expanded. The end portion of the cutting tool D contacting with the adjusting screw133is provided to be gradually reduced. The portion where the adjusting screw133and the cutting tool D contact with each other is provided to have a 45 degrees chamfer shape C, respectively.

The adjusting screw133and the cutting tool D contact with each other in the 45 degrees chamfer shape C, thereby preventing the oil from being formed on the contact area between the adjusting screw133and the cutting tool D. The oil is prevented from being formed, such that it is unnecessary to increase the pressure for pushing out the formed oil. Therefore, it is possible to improve the discharge responsiveness.

Referring toFIG. 10, the cutting processing system of an embodiment of the present disclosure additionally provides a pressure intensifier700and a surge tank800to the pneumatic unit400.

The pressure intensifier700intensifies the air supplied from the outside. For example, the air supplied from the outside is 3 to 4 bar. The air intensified through the pressure intensifier700is boosted to 6 to 8 bar. The surge tank800receives and stores the air intensified from the pressure intensifier700. The surge tank800is connected to the pneumatic unit400and supplies the intensified air according to an operation of the pneumatic unit400.

As the pressure of the air supplied from the pneumatic unit400to the lance200increases, the discharge pressure of the mist discharged from the cutting tool D increases. Therefore, the chip generated on the cut area does not remain. In some cases, only compressed air may also be supplied through the cutting tool D to the cut area.

The cutting processing system according to an embodiment of the present disclosure configured as described above provides a performance test paper900for evaluating the discharge responsiveness of the cutting processing system in order to evaluate the discharge responsiveness regardless of the type of the cutting tool D.

Referring toFIG. 11, the performance test paper900for evaluating the discharge responsiveness of the cutting processing system according to an embodiment of the present disclosure is made of a material that smears the mist discharged through the cutting tool D and does not spread. According to an example, the performance test paper900may be an oil paper. The performance test paper900includes an X-Y coordinate axis910, a discharge line920, a test start position point S, a test stop position point F, a horizontal dimension line L1, a vertical dimension line L2, and a remarks column930.

The X-Y coordinate axis910becomes a reference for the horizontal movement and the vertical movement of the spindle100in the discharge responsiveness test. The origin (0, 0) of the X-Y coordinate axis910is the lower left corner of the performance test paper900. The discharge line920is illustrated to be horizontal with the X-axis of the X-Y coordinate axis910in order to become the injecting target of the mixed mist of oil and air through the cutting tool D. The discharge line920is provided in plural at regular intervals along the Y axis of the X-Y coordinate axis910.

The shaft112of the spindle100starts rotating at the test start position point S. When the cutting tool D moves from the test start position point S and reaches the discharge line920, the controller600operates the rotary union300, the pneumatic unit400, and the oil supply unit500to inject the mist from the cutting tool D. The cutting tool D stops discharging at the last point of the discharge line920and moves to the test stop position point F.

The test stop position point F is provided at the other side of the discharge line920. The rotation and movement of the spindle100are stopped at the test stop position point F. The test start position point S and the test stop position point F are horizontal with the discharge line920and are provided in a state of being spaced apart from each other to have a distance from the discharge line920.

The horizontal dimension line L1is provided under the discharge line920. The horizontal dimension line L1measures the horizontal movement distance of the spindle100. The vertical dimension line L2is provided at the side portion of the discharge line920. The vertical dimension line L2measures the height movement distance of the spindle100and the test cycle.

The remarks column930is provided under the vertical dimension line L2. The remarks column930is provided to write a test date, the movement speed of the spindle100, and the RPM of the spindle100.

The discharge response speed performance test through the performance test paper configured as described above is performed so that the cutting tool D is disposed on the lowermost end thereof and moves to the right side starting from the test start position point S1provided on the left side thereof. The mist is discharged only to the discharge line920.

Then, the rotation is stopped at the test stop position point F1provided on the right side of the discharge line920to terminate a first test. After terminating the first test, a second test is performed after the cutting tool D moves vertically without the horizontal movement. The cutting tool D is moved to the test start position point S2provided to the right side of the second discharge line920.

The second test starts at the test start position point S2. The cutting tool D moves from right to left, injects the mist to the discharge line920, and terminates at the test stop position point F2.

That is, the cutting tool D is moved by height for each test cycle, the odd-numbered test is performed by moving the cutting tool D from left to right, and the even-numbered test is performed by moving the cutting tool D from right to left.

According to the cutting processing system of an embodiment of the present disclosure configured as described above, the oil and the air are supplied in a non-mixed state to the cutting tool D through the lance200. The oil and the air are mixed inside the drill holder130. The contact area between the cutting tool D and the adjusting screw133may be provided in a chamfer shape C, thereby minimizing the mist formation inside the drill holder130and securing the mist discharge responsiveness even if a small amount of oil is ultimately supplied as compared with the convention.

In addition, it is possible to supply air to the cutting tool D in a state further pressurized through the pressure intensifier to discharge the mist to the processing portion at a greater pressure, thereby separating the chip generated during the cutting processing from the processing portion more smoothly.

In addition, it is possible to perform the test actually discharging the mist from the cutting tool D toward the performance test paper, thereby evaluating the mist discharge responsiveness through the cutting tool regardless of the type of the cutting tool D.