CUTTING TOOL

Abstract

Cutting tool (100), which a main component (110) in the interior of which a flow path (161, 162, 163, 164) is provided, through which coolant circulates from a shaft section (120) to a head section (130), and a nozzle (150, 150') which is provided by the flow path (161, 162, 163, 164) at an opening end section (133) of the head section (130), and discharges the coolant into a cutting area, wherein the nozzle (150, 150'), when the coolant has been supplied from the shaft section (120) to the head section (130), is brought into a protrusion state by a flow pressure of the coolant, in which it protrudes towards the cutting area, and when a front end section (153) of the The nozzle (150, 150') has absorbed external forces in the direction of the opening end section (133), enters a retraction state in which it retracts, and In the retracted state, a rear end section (154) of the nozzle (150, 150') which absorbs the flow pressure has no surface contact with other components on the side opposite the front end section (153).

Description

[Technical field]

[0001] The present invention relates to a cutting tool. [Background technology]

[0002] A technique is known in which a coolant is introduced into the cutting area to eliminate heat generated during the cutting of a workpiece with a cutting tool and to reduce frictional forces. Recently, particular attention has been paid to a cutting tool in which a nozzle for dispensing a coolant is provided on a head section (see, e.g., patent publication no. JP 2012-517908 (A)).

[0003] JP 2005-81 459 A describes a cutting tool with an oil bore, equipped with a cutting edge and a nozzle whose opening is directed towards the cutting edge. The oil holes for expelling the externally supplied cutting medium from the opening to the cutting edge are formed by an oil hole on the cutting tool. The nozzle is designed to move towards and away from the cutting edge. The nozzle is advanced towards the cutting edge by pressing on it, using the energy supplied by an elastic element. [Summary of the invention][Problem to be solved by the invention]

[0004] If a structure is used in which a nozzle is provided on the head section of a cutting tool that can be moved back and forth, and the nozzle transitions from a retraction state to a forward state using a flow pressure of a coolant, the phenomenon often occurs that the nozzle does not transition to the forward state, even though the supply of coolant to the cutting tool has begun.

[0005] The present invention was developed to solve this problem and aims to provide a cutting tool in which a nozzle designed to be movable forwards and backwards reliably transitions into the forward position simultaneously with the start of the coolant supply. [Means of solving the problem]

[0006] The cutting tool according to a specific aspect of the present invention comprises a main component in the interior of which a flow path is provided through which coolant circulates from a shaft section to a head section, and a nozzle which is provided by the flow path at an opening end section of the head section and discharges the coolant into a cutting area, wherein the nozzle, when the coolant has been supplied from the shaft section to the head section, is forced into a forward position by a flow pressure of the coolant, in which it extends towards the cutting area, and when a front end section of the nozzle has absorbed external forces in the direction of the opening end section, is forced into a retracted position, in which it retracts, and furthermore, in the retracted position, a rear end section of the nozzle, which absorbs the flow pressure, has no surface contact with other components on the side opposite the front end section. [Effects of the invention]

[0007] The present invention enables the nozzle to reliably transition into the forward position simultaneously with the start of the coolant supply. [Brief explanation of the characters] [ Fig. 1] Fig. Figure 1 is a perspective overall view of a cutting tool according to a present embodiment. [ Fig. 2] Fig. Figure 2 is a perspective external view of a head section in a nozzle leading position. [ Fig. 3] Fig. Figure 3 is a perspective external view of the head section in a retracted state of the nozzle. [ Fig. 4] Fig. Figure 4 is a perspective drawing of the section showing a flow path provided inside a main component, etc. [ Fig. 5] Fig. Figure 5 is a schematic cross-section of the head section, showing the nozzle's protrusion state. [ Fig. 6] Fig. Figure 6 is a schematic cross-section of the head section, showing the retracted state of the nozzle. [ Fig. 7] Fig. Figure 7 is a schematic view showing another embodiment of the nozzle and a closure. [ Fig. 8] Fig. Figure 8 is a schematic view showing yet another embodiment of the nozzle and the closure. [Embodiments of the invention]

[0008] The present invention is explained below with reference to embodiments of the invention, although the invention is not limited to the following embodiments according to the claims. Furthermore, not all structures described with reference to the embodiments are necessarily essential for solving the problem.

[0009] Fig. Figure 1 is a perspective overall view of a cutting tool 100 according to a present embodiment. The cutting tool 100 according to the present embodiment is a cutting tool 100 for a lathe. The cutting tool 100 comprises a main component 110 and a nozzle 150. The main component 110 has a shank section 120, which is a section of a handle attached to a chuck of the lathe, and a head section 130 on which the nozzle 150 is arranged and a cutting insert 200 is mounted. A supply opening 121 for supplying a coolant into an internal flow path, described later, is provided on the shank section 120. The coolant is supplied from an external tank to the internal flow path of the cutting tool 100 via a hose connected to the supply opening 121.The supply of coolant to the cutting tool 100 can also be made not via a hose, but in a form directly connected to a coolant supply opening provided on a tool holder or the chuck of a machine tool.

[0010] The head section 130 has a nozzle guide section 131, through which the nozzle 150 is guided for forward and backward movement as described later, and a mounting section 132, which is formed in a recessed shape to allow the cutting insert 200 to be received and mounted. In the present embodiment, the nozzle guide section 131 is formed integrally with the shaft section 120 and the head section 130; however, it can also be designed to be detachable from the head section 130. With a detachable design, there is no restriction to inserting the nozzle 150 from the rear end of the nozzle guide section 131, as described later, but the nozzle 150 can also be received from the contact surface side that is in contact with the head section 130. The detachably designed nozzle guide section 131 is, for example, B. by means of a fastening screw 210 on the surface of the head section 130.

[0011] The cutting insert 200 is an interchangeable cutting edge plate, e.g., in the diamond shape shown, which is arranged on the mounting section 132 and fastened to the mounting section 132 by a fastening screw 210. The cutting insert 200, whose cutting performance has decreased due to a particular use, is removed from the mounting section 132 and replaced with another cutting insert 200. In the present embodiment, the cutting tool 100, in which a diamond-shaped cutting insert 200 is mounted, is described. However, a cutting tool 100 is also possible in which a cutting insert 200 of a different shape, such as a triangular, rectangular, or round cutting insert 200, can be mounted.Furthermore, there is no restriction to a cutting tool 100 in which a cutting insert 200 is arranged and fastened on a mounting section 132, but it can also be a cutting tool 100 in which a different mounting method is used.

[0012] Fig. Figure 2 is a perspective view of the head section 130 in the advanced position of the nozzle 150. When the coolant supply to the cutting tool 100 begins, the nozzle 150 springs forward from the nozzle guide section 131, guided by an opening end section 133 of the nozzle guide section 131, in the direction indicated by an arrow and enters the advanced position. The direction indicated by the arrow is the direction of the cutting area, which is the area and its surrounding area where the blade of the cutting insert 200 comes into contact with the workpiece and cuts it. Therefore, in the operating state, where the cutting tool 100 cuts the workpiece, the coolant is discharged from the nozzle 150 into the cutting area.

[0013] The coolant is a medium supplied to dissipate heat generated in the cutting area and reduce frictional forces between the cutting edge and the workpiece. This medium can be a water-oil emulsion, cutting oil, compressed air, liquefied gas, etc. To improve heat dissipation and friction reduction, it is preferred that the discharge opening of the nozzle 150 be located as close as possible to the cutting area. When the discharge opening of the nozzle 150 is near the cutting area, the same heat dissipation and friction reduction effect can be achieved with a smaller quantity of coolant compared to a greater distance. Furthermore, the head section 130 can be made smaller, as the flow path within the head section 130 can also be reduced if a smaller quantity of coolant is sufficient.From this point of view, the nozzle 150 in the present embodiment is designed such that, in the forward state, the discharge opening in the form of the front end section extends further than the center of the fastening screw 210 to the cutting area side.

[0014] Fig. Figure 3 is a perspective view of the head section 130 in the retracted state of the nozzle 150. If no coolant is supplied to the cutting tool 100, the nozzle 150 retracts, for example, when an operator pushes its front end towards the opening end section 133. In this retracted state, it is received inside the nozzle guide section 131 and retracts. More specifically, the nozzle 150 is retracted from the space above the cutting insert 200.

[0015] If the nozzle 150 is retracted from the space above the cutting insert 200 in this manner, an operator can easily replace the cutting insert 200 with minimal risk of damage to the nozzle 150. As long as the replacement of the cutting insert 200 is easy, part of the nozzle 150 may cover this upper space when retracted.

[0016] Fig. Figure 4 is a perspective drawing of the section showing the flow path provided inside the main component 110, etc. The externally visible shape of the main component 110 is shown with dashed lines, and the internal flow path is shown with a solid line. Furthermore, the external shape of the nozzle 150 and the closures 171, 172 are shown with solid lines.

[0017] As described above, a flow path is provided inside the main component 110 in which coolant circulates from the shaft section 120 to the head section 130. In the present embodiment, this internal flow path is configured to include a central opening 161, a head opening 162, a closure opening 163, and a guide opening 164, each formed by a drill bit. The central opening 161 is a flow path located primarily inside the shaft section 120 along its longitudinal direction and is connected to the aforementioned supply opening 121. The head opening 162 is a flow path located inside the head section 130 and is connected to the end section of the central opening 161. The head opening 162 directs the coolant flowing from the central opening 161 to the nozzle guide section 131.A bore opening of the head opening 162, positioned on the underside of the head section 130, is closed by the closure 171. A closure screw, a metal bolt, etc., can be used as the closure 171.

[0018] The closure opening 163 and the guide opening 164 are flow paths provided inside the nozzle guide section 131, running essentially in the same direction and communicating with each other. One end of the head opening 162 is connected to and communicates with the closure opening 162 near the interface between the closure opening 163 and the guide opening 164, or from the closure opening 163 at a location near the interface in question. The inner diameter of the closure opening 163 is larger than the inner diameter of the nozzle guide section 131. The nozzle 150 is inserted through a rear end opening 135 of the closure opening 163, which is open at the rear end of the nozzle guide section 131, and is positioned in the guide opening 164.The guide opening 164 has an opening end section 133 on the side of the front end of the nozzle guide section 131, at which the front end section 153 of the nozzle 150 projects towards the outside. That is, the closure opening 163 and the guide opening 164 together form a through-bore passing through the nozzle guide section 131.

[0019] The outer circumferential side of the nozzle 150 is slidably fitted relative to the inner circumferential side of the guide opening 164, with the nozzle 150 being guided in the central axis direction of the guide opening 164. Furthermore, the inner diameter of the guide opening 164 near the opening end section 133 is smaller than the inner diameter of the remaining section, with the different inner diameter forming a rim-shaped contact section 134. A stepped section 151 is provided at the front end of the outer circumferential side of the nozzle 150, which is fitted to the inner circumferential side of the guide opening 164. As the nozzle 150 emerges from the opening end section 133, the stepped section 151 bearing against the contact section 134 prevents the nozzle 150 from falling off. This means that, in the forward state, the section of the nozzle 150 that extends further on the front end than the stage section 151 extends further forward than the opening end section 133.

[0020] After the nozzle 150 has been positioned in the guide opening 164, the closure 172 is screwed into the closure opening 163 and closes the rear end opening 135. As with the closure 171, a closure screw, a metal bolt, etc., can be used as the closure 172.

[0021] Fig. Figure 5 is a schematic cross-section of the head section 130, showing the advance state of the nozzle 150. The coolant, supplied from the head opening 162 to the closure opening 163 and the guide opening 164, flows to an inner hole 152 of the nozzle 150, which is fitted into the guide opening 164, and is discharged from the opening of the front end section 153. At this point, a conical section 155, located near the rear end section 154 of the nozzle 150 on the opposite side of the front end section 153, absorbs the flow pressure of the coolant from the inner hole 152, which acts as a force for the advance of the nozzle 150. This means that when the coolant circulates through the inner hole 152 of the nozzle 150, the nozzle 150 is pushed in the direction of advance by the flow pressure absorbed by the cone section 155.Then the stage section 151 comes into contact with the system section 134, causing the nozzle 150 to enter the forward position. While the coolant is supplied, the cone section 155 continues to absorb the flow pressure, thus maintaining the forward position of the nozzle 150. Since at least part of the guide opening 164 performs the function of guiding the nozzle 150 as described above, it can be said that for the internal flow path, the coolant circulates indirectly via the inner hole 152 of the nozzle 150.

[0022] Fig. Figure 6 is a schematic cross-section of the head section 130, showing the retracted state of the nozzle 150. In a state where no coolant is supplied, no forces act to protrude the nozzle 150, so that, as described above, the front end section 153 is pushed by the external forces, and the nozzle 150 then retracts. In the retracted state, the rear end section 154 of the nozzle 150 abuts an end face 173 of a closure 172, thus preventing the entire nozzle 150 from entering the interior of the nozzle guide section 131. In other words, the arrangement position inside the closure opening 163 is set such that the closure 172 achieves a proper retraction state of the nozzle 150.

[0023] In a conventional cutting tool with a retractable nozzle structure, the phenomenon frequently occurs that the nozzle does not move into the forward position, even though the supply of coolant to the cutting tool has begun. The inventors of the present application analyzed this phenomenon and discovered that, when moistened by the coolant, the rear end face of the nozzle adheres firmly to another component, which acts as a stopper when the nozzle retracts. They found that, in this firm, surface-contact state, no coolant enters the inner hole of the nozzle, or if it does, it cannot exert a flow pressure sufficient to break the firm adhesion.

[0024] Therefore, in the present embodiment of the cutting tool 100, a design is employed in which the rear end section 154 of the nozzle 150, which absorbs the flow pressure of the coolant in the retracted state, does not have surface contact with the end surface 173 of the closure 172. Specifically, this design involves a configuration in which the central axis of the closure 172 in the closing direction and the central axis of the nozzle 150 in the advance and retraction directions are not coaxial, but rather intersect. As a result, the central axis of the closure opening 163 fitted into the closure 172 is inclined by a few degrees (approximately 7 degrees in the illustrated example) relative to the central axis of the guide opening 164 that guides the nozzle 150. The end surface 173 of the closure 172 is generally formed as a plane orthogonal to the central axis of the closure 172 in the closing direction, so that by applying such a design it has no surface contact with the rear end section 154 of the nozzle 150.

[0025] Since the rear end section 154 of the nozzle 150 and the end surface 173 of the shutter 172 do not have surface contact, no mutual adhesive force acts upon them, and since a gap is created between them, the coolant can enter more easily. Consequently, the nozzle 150 can reliably transition from the retracted state to the extended state, because when coolant is supplied, its flow pressure is easily absorbed. It is not a requirement that the central axis of the shutter 172 and the central axis of the nozzle 150 be in an intersecting relationship to each other; even if they are in a torsional relationship, surface contact between the rear end section 154 of the nozzle 150 and the end surface 173 of the shutter 172 can be avoided.

[0026] The intersection angle (approximately 7 degrees in the preceding example) and torsion angle of the central axis of the closure 172 and the central axis of the nozzle 150 is desirablely an angle at which the surface tension of the coolant remaining between the rear end section 154 of the nozzle 150 and the end surface 173 of the closure 172 substantially prevents adhesion between the two. While the optimal angle also depends on the shape of the rear end section 154 and the viscosity of the coolant, it should specifically be an angle at which at least either the entire rear end section 154 or the entire end surface 173 is not covered by the remaining coolant.

[0027] An exemplary embodiment of the present design has been described above, but various other structures can also be used in which the rear end section 154 of the nozzle 150 does not have surface contact with other components. Some further exemplary embodiments are described below.

[0028] Fig. Figure 7 is a schematic view showing another embodiment of a nozzle 150' and a closure 172. In the nozzle 150', a flanged section 156 is provided at the rear end section 154 instead of the conical section 155. The flanged section 156 primarily absorbs the flow pressure of the coolant, which causes the nozzle 150' to transition from the retracted to the extended state. In this configuration, the flanged surface of the flanged section 156 has point or line contact with the end surface 173 of the closure 172, so that a gap is also created between the two, and the nozzle 150' more easily absorbs this flow pressure when the coolant is supplied.

[0029] Fig. Figure 8 is a schematic view showing yet another embodiment of the nozzle 150' and the closure 172. The nozzle 150' is identical to the nozzle 150' in Fig.7, and features the flange section 156. The closure 172 has a projecting section 174 for contact with the flange section 156. The nozzle 150' and the closure 172 with this configuration have point contact with each other, so that a gap is also created between the two, and the nozzle 150' more easily absorbs this flow pressure when the coolant is supplied. When using such a structure, the central axis of the closure 172 and the central axis of the nozzle 150' can also be coaxial. The rear end section 154 of the nozzle 150' is not limited to the application of the flange section 156 and can have any structure, provided it is a structure that accommodates the projecting section 174 with point contact.Furthermore, multiple projection sections 174 cannot be provided as long as the structure is one in which a gap is created between the projection section 174 and the rear end section of the nozzle. For example, the structure may be one in which the end surface of the closure is formed as a convexly curved surface, and a surface section provided on the rear end section 154 of the nozzle 150' receives it with point contact.

[0030] In the respective embodiments described above, structures "not having surface contact" were explained, although even point contact and line contact can, strictly speaking, be considered microscopic surface contact when viewed at the micro level. Therefore, in the present embodiment, "not having surface contact" means that the mutual contact area lies within 3% of the projection area of ​​the rear end section 154. It was ensured that, as long as the contact area is within this range, a suitable transition of the nozzle 150' to the forward state occurs when the rear end section 154 absorbs the flow pressure of the coolant.

[0031] In the stopper structure described above in the respective embodiments, structures were described in which the rear end section 154 of the retracting nozzle 150' is received by a closure 172. However, it can also be a structure in which the rear end section 154 of the nozzle 150' is received by another component. In any case, the rear end section 154 of the nozzle 150' should not have surface contact with the other component in question. Furthermore, there is no restriction to the case of an interchangeable form in which, as in the embodiments described above, the cutting insert 200 is detachably mounted on the cutting tool 100, so that it can also be a cutting tool 100 in which the cutting blade at the front end of the head section 130 is formed in one piece.With such a cutting tool 100, it can also be expected that damage to the nozzle 150' will be prevented if the nozzle 150' is in a retracted position when not in use. Furthermore, the cutting tool 100 described above was a tool for a lathe, but the structure described above is also applicable, without being limited to a lathe, to a cutting tool 100 used for another machine tool. For example, it is also possible to incorporate it into a cutting tool 100 used for a milling machine or a drilling machine. [Explanation of reference symbols] 100 cutting tools 110 Main component 120 shaft section 121 Inlet 130 Head section 131 Nozzle guide section 132 Assembly section 133 Opening end section 134 Plant section 135 rear end opening 150, 150' nozzle 151 Step section 152 inner hole 153 front end section 154 rear end section 155 Cone section 156 Flange section 161 medium opening 162 Head opening 163 Closure opening 164 Guide opening 171, 172 Closure 173 End area 174 Lead section 200 cutting insert 210 Mounting screw

Claims

[1] Cutting tool (100), which a main component (110) in the interior of which a flow path (161, 162, 163, 164) is provided, through which coolant circulates from a shaft section (120) to a head section (130), and a nozzle (150, 150') which is provided by the flow path (161, 162, 163, 164) at an opening end section (133) of the head section (130), and discharges the coolant into a cutting area, wherein the nozzle (150, 150'), when the coolant has been supplied from the shaft section (120) to the head section (130), is brought into a protrusion state by a flow pressure of the coolant, in which it protrudes towards the cutting area, and when a front end section (153) of the The nozzle (150, 150') has absorbed external forces in the direction of the opening end section (133), enters a retraction state in which it retracts, and In the retracted state, a rear end section (154) of the nozzle (150, 150') which absorbs the flow pressure has no surface contact with other components on the side opposite the front end section (153). [2] Cutting tool (100) according to claim 1, wherein the head section (130) has a mounting section (132) for mounting an interchangeable cutting insert (200). [3] Cutting tool (100) according to claim 1 or 2, wherein a through-bore (163, 164) provided on the head section (130) for arranging the nozzle (150, 150') on the opening end section (133) is closed by a closure (171, 172), and In the retracted state, the rear end section (154) of the nozzle (150, 150') is in contact with the closure (171, 172). [4] Cutting tool (100) according to claim 3, wherein the central axis of the closure (171, 172) and the central axis of the nozzle (150, 150') are in an intersecting or torsional relationship.

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