Patent Application
20240123511
The present invention relates to a cutting tool for machine tools.
A great deal of heat and chips are generated in a machining process, and therefore coolant is jetted directly toward a cutting area to remove heat and evacuate chips.
In a general machine tool, the coolant is delivered to a position nearby the cutting tool via a coolant circuit, and then the coolant is jetted toward a cutting edge of the cutting tool via an independent nozzle at the end of the coolant circuit. However, both the coolant circuit and the nozzle occupy an inner space of the machine tool, and easily interfere with a workpiece to be machined or other components in the machine tool. As a result, a conventional coolant system in the general machine tool is inconvenient to use.
With reference to
However, the conventional cutting tools 91 with the coolant passages 911 have the following shortcomings:
First, the coolant passages 911 are formed inside the cutting tools 91 by making multiple elongated holes in each of the cutting tools 91 through drilling. However, the cutting tools 91 are made of high hardness metal, and therefore it is very difficult to drill holes in the cutting tool. As a result, manufacturing costs of the conventional cutting tools 91 with internal coolant passages 911 are tremendous.
Second, an outer end of the cutting tool 91 has cutting inserts or has integrally formed cutting edges. In order to ensure the cutting tool 91 has sufficient structural rigidity for machining, the coolant passage 911 cannot extend linearly from the inner end to the outer end of the cutting tool 91, but instead has to make a turn before reaching the outer end to avoid the cutting inserts or the cutting edges. As a result, the coolant may fail to cool down the cutting area because the coolant is blocked by the workpiece 93 or due to other reasons, and resulting in a poor cooling performance.
Third, because the coolant passage 911 cannot extend linearly but instead has to make the turn, the coolant passage 911 has higher friction loss, which reduces flow of the coolant and deteriorates cooling performance.
To overcome the shortcomings, the present invention provides a cutting tool with through coolant to mitigate or obviate the aforementioned problems.
The main objective of the present invention is to provide a cutting tool with through coolant to reduce cost and to improve cooling performance.
The cutting tool with through coolant is configured to be connected to a machine tool. The machine tool has a tool-fixing hole, and one end of the tool-fixing hole is connected to a coolant-supply system. The cutting tool is configured to be mounted in another end of the tool-fixing hole. The cutting tool has a shank and a cutting portion. The shank is elongated, and two opposite ends of the shank are respectively a shank-outer end and a shank-inner end. An outer peripheral surface of the shank is configured to be surrounded and tightly held by a hole-wall defined by the tool-fixing hole. At least one coolant-guiding recess is formed in the outer peripheral surface of the shank. Each of the at least one coolant-guiding recess extends along a lengthwise direction of the shank, and is configured to form a coolant channel together with the hole-wall of the tool-fixing hole. An end of the coolant channel is connected to the coolant-supply system. The cutting portion is formed on the shank-outer end of the shank and is configured to protrude out from the tool-fixing hole. The cutting portion has at least one cutting edge formed on the cutting portion, or at least one insert is removably mounted to the cutting portion. The coolant channel formed by the at least one coolant-guiding recess enables coolant from the coolant-supply system to be jetted toward the cutting portion.
Installation and use of the present invention is same as that of conventional cutting tools: install the cutting tool to the machine tool with a specialized coolant-supply system, such as a milling machine with a through-spindle coolant system. After installation of the cutting tool, the coolant-guiding recess on the shank forms the coolant channel, thereby providing the cutting tool with through coolant function.
Advantages of the present invention are as follows:
First, the coolant channel is formed by the coolant-guiding recess together with the hole-wall of the tool-fixing hole, and forming of the coolant-guiding recess requires only machining on the outer peripheral surface of the shank. The coolant-guiding recess provides coolant through function when installed on the machine tool, thereby saving tremendous machining cost.
In other words, in terms of forming the of coolant channel, the present invention replaces the conventional deep-hole-drilling process with grooving on the outer peripheral surface of the shank. The present invention is capable of saving tremendous machining cost because grooving on the outer peripheral surface is far more easier than deep-hole-drilling.
Second, because the coolant-guiding recess is formed on the outer peripheral surface of the shank and extends along the lengthwise direction of the shank, the coolant is naturally jetted toward the cutting edge or the insert when the cutting portion is narrower than the shank, or the coolant naturally travels along an outer surface of the cutting portion to the cutting edge or the insert when the cutting portion is wider than the shank. As a result, the present invention enables the coolant to continuously cool down a cutting area by preventing the coolant from being blocked by the workpiece or fail to cool down the cutting area due to any other reason.
Third, due to position and shape of the coolant-guiding recess, the coolant-guiding recess can extend linearly without turning, and therefore greatly reduces friction loss. In other words, the present invention improves cooling performance by eliminating inevitable turning in the conventional cutting tool.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
With reference to
The machine tool 92 is preferably a milling machine, and the cutting tool 10 is preferably a milling cutter. The cutting tool 10 is fixed to a spindle 924 (as shown in
The cutting tool 10 is mounted in the tool-fixing hole 921 via a bottom opening of the tool-fixing hole 921. In the preferred embodiment, the coolant-supply system 922 is a through-spindle coolant system of the milling machine. The coolant-supply system 922 is a conventional standard system; therefore, detailed description of the coolant-supply system 922 is omitted.
The cutting tool 10 has a shank 11 and a cutting portion 12. The shank 11 is elongated, and is preferably a round rod. An outer peripheral surface of the shank 11 is surrounded and tightly held by a hole-wall defined by the tool-fixing hole 921 such that the cutting tool 10 is fixed to the machine tool 92.
Multiple coolant-guiding recesses 111 are formed in the outer peripheral surface of the shank 11. Each of the coolant-guiding recesses 111 extends along a lengthwise direction of the shank 11, and is configured to form a coolant channel together with the hole-wall of the tool-fixing hole 921. An end of the coolant channel 112 is connected to the coolant-supply system 922, allowing the coolant-supply system 922 to pump coolant to the coolant channel 112 via said end. Each of the coolant-guiding recesses 111 preferably extends linearly. In the preferred embodiment, the coolant-guiding recess 111 is only formed in the shank 11, but the coolant-guiding recess 111 is not limited thereto. In another preferred embodiment, the coolant-guiding recess 111 extends to the cutting portion 12.
Two opposite ends of the shank 11 are respectively a shank-outer end 113 and a shank-inner end 114. The shank-inner end 114 is disposed in the tool-fixing hole 921. An end of each of the coolant-guiding recesses 111 extends towards the shank-inner end 114 and preferably forms an opening on an end-surface of the shank-inner end 114 such that the coolant can flow into the coolant-guiding recess 111 without making a turn. Another end of the coolant-guiding recess 111 preferably extends to the shank-outer end 113, but not limited thereto as long as said another end of the coolant-guiding recess 111 protrudes out from the tool-fixing hole 921.
The cutting portion 12 is formed on the shank-outer end 113 of the shank 11 and protrudes out from the tool-fixing hole 921. The cutting portion has one or multiple cutting edges 121. To be precise, the cutting portion 12 is disk-shaped, and is preferably round disk-shaped.
The cutting edges 121 are formed on an outer annular surface of the cutting portion 12, and the cutting portion 12 is larger in width than the shank 11 such that the cutting portion 12 is capable of cutting a side surface of a workpiece 93 to form a groove.
With reference to
A cross-sectional area of each of the coolant-guiding recesses 111 reduces from the shank 11 toward the cutting portion 12 such that the coolant channel 112 gradually becomes narrower, thereby increasing a flow speed of the coolant while exiting the coolant channel 112. To be specific, a width and/or a depth of each of the coolant-guiding recess 111 gradually reduces from the shank 11 toward the cutting portion 12, but the coolant-guiding recesses are not limited thereto.
With reference to
The cutting portion 12A has no integrally formed cutting edge, but instead one or multiple inserts 122A is/are mounted to the cutting portion 12A. An end of each coolant-guiding recess 111A forms an opening on an end-surface of the shank-inner end 114A, and another end of each coolant-guiding recess 111A forms an opening on an end-surface of the shank-outer end 113A. The cutting tool 10A in the second embodiment is preferably an end mill of a face mill.
With reference to
With reference to
To be precise, multiple helical chip-flutes 123C are formed in the cutting portion 12C, and each of the helical chip-flutes 123C is preferably disposed between two adjacent ones of the cutting edges 121C. An end of each of the coolant-guiding recesses 111C is connected to one of the helical chip-flutes 123C to improve chip evacuation performance of the coolant.
With reference to
In summary, by forming the coolant-guiding recesses 111 in the outer peripheral surface of the shank 11, the cutting tool 10 is capable of providing coolant through function when mounted to the machine tool 92, thereby saving tremendous machining cost.
Moreover, because the coolant-guiding recess 11 extends along the lengthwise direction of the shank, 11, the coolant is naturally jetted toward the cutting edges 121 or the inserts 122A when the cutting portion 12 is narrower than the shank 11, or the coolant naturally travels along an outer surface of the cutting portion 12 to the cutting edge 121 or the insert 122A when the cutting portion is wider than the shank. As a result, the present invention enables the coolant to continuously cool down a cutting area. Additionally, the coolant-guiding recesses 111 can extend linearly without turning, thereby reducing friction loss.
Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and features of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
